Electronic device and program

Abstract

The present invention provides an electronic device having an authentication function. The electronic device has a display unit. The display unit has a plurality of light-emitting elements and a plurality of light-receiving elements. The light-receiving element receives light emitted from the light-emitting element and then reflected from a subject. When the illuminance of external light is equal to or less than a first value, the light-emitting element emits light at a first illuminance and the light-receiving element receives light during a first detection period. When the illuminance of the external light is higher than the first value, the light-emitting element emits light at a second illuminance higher than the first illuminance, and the light-receiving element receives light during a second detection period shorter than the first detection period.

Description

Electronic devices and programs

[0001] 1. Field of the Invention One aspect of the present invention relates to an electronic device. One aspect of the present invention relates to a program to be executed by an electronic device. One aspect of the present invention relates to a method for operating an electronic device. One aspect of the present invention relates to a method for authenticating an electronic device.

[0002] Note that one embodiment of the present invention is not limited to the above technical field. Examples of the technical field of one embodiment of the present invention disclosed in this specification and the like include semiconductor devices, display devices, light-emitting devices, power storage devices, memory devices, electronic devices, lighting devices, input devices, input / output devices, driving methods thereof, and manufacturing methods thereof. A semiconductor device refers to any device that can function by utilizing semiconductor characteristics.

[0003] In recent years, information terminal devices such as mobile phones such as smartphones, tablet information terminals, and notebook PCs (personal computers) have become widespread. These information terminal devices often contain personal information, and various authentication technologies have been developed to prevent unauthorized use.

[0004] For example, Patent Document 1 discloses an electronic device that includes a fingerprint sensor in a push button switch section.

[0005] US Patent Application Publication No. 2014 / 0056493

[0006] An object of one embodiment of the present invention is to provide a display unit having a light detection function. Another object is to provide a high-resolution display unit having a light detection function. Another object is to provide a display device having a light detection function. Another object is to provide a high-resolution display device having a light detection function. Another object is to provide an electronic device having a display function. Another object is to provide an electronic device having a light detection function. Another object is to provide an electronic device having an authentication function typified by fingerprint authentication. Another object is to provide an electronic device with high security. Another object is to provide an electronic device with high operability. Another object is to provide a multifunctional electronic device. Another object is to provide a novel electronic device. Another object is to provide an electronic device having a high-security authentication method. Another object is to provide an electronic device having a novel operation method. Another object is to provide an electronic device having a novel authentication method.

[0007] Another object of one embodiment of the present invention is to provide a program to be executed by a highly secure electronic device, to provide a program to be executed by a new electronic device, or to provide a new program.

[0008] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these can be extracted from the description of the specification, drawings, claims, etc.

[0009] One embodiment of the present invention is an electronic device that includes a display unit including a plurality of light-emitting elements and a plurality of light-receiving elements. The light-receiving elements receive light that is emitted from the light-emitting elements and reflected from a subject. When the illuminance of external light is equal to or lower than a first value, the light-receiving elements receive light for a first detection period, and the light-emitting elements emit light at a first luminance during the first detection period. When the illuminance of external light is higher than the first value, the light-receiving elements receive light for a second detection period that is shorter than the first detection period, and the light-emitting elements emit light at a second luminance that is higher than the first luminance during the second detection period.

[0010] In the above aspect, it is preferable that the light receiving element receives light during a first detection period when the illuminance of external light is equal to or less than a first value, and receives light during a second detection period when the illuminance of external light is higher than the first value.

[0011] Alternatively, one embodiment of the present invention includes a display unit including a plurality of pixel circuits and a plurality of second elements. The pixel circuits include a first element and a current control unit. The first element includes a first electrode, a second electrode, and a first light-emitting layer located between the first electrode and the second electrode. The current control unit includes a first terminal and a second terminal connected to the second electrode. The first electrodes of the first elements included in the plurality of pixel circuits are connected to each other. The first terminals of the current control units included in the plurality of pixel circuits are connected to each other. The second element emits light from the first element. The electronic device receives emitted light reflected from a subject, and when the illuminance of external light is equal to or less than a first value, the second element receives light for a first detection period, and the first element emits light at a first luminance during the first detection period; when the illuminance of external light is higher than the first value, the second element receives light for a second detection period that is shorter than the first detection period, and the first element emits light at a second luminance that is higher than the first luminance during the second detection period; and the potential difference between the first terminal and the first electrode when light is emitted at the second luminance is greater than the potential difference between the first terminal and the first electrode when light is emitted at the first luminance.

[0012] In the above aspect, it is preferable that the current control unit has a first transistor, one of the source and drain of the first transistor is connected to the first terminal, and the other of the source and drain of the first transistor is connected to the second terminal.

[0013] In the above aspect, it is preferable that the current control unit has a first transistor, and when the first element emits light, a potential corresponding to the first terminal is applied to one of the source and drain of the first transistor, and the current of the first element is controlled by the first transistor.

[0014] In the above aspect, the product of the first luminance and the length of the first detection period is preferably 0.8 to 1.2 times the product of the second luminance and the length of the second detection period.

[0015] In the above aspect, it is preferable that the subject is a first finger that is in contact with or close to the surface of the display unit, and that the device has a function of acquiring fingerprint information of the first finger.

[0016] In the above aspect, it is preferable that the device has a memory unit, the subject is a first finger that is in contact with or close to the surface of the display unit, and the memory unit has fingerprint information of a second finger and has a function of acquiring the fingerprint information of the first finger and a function of comparing the fingerprint information of the first finger with the fingerprint information of the second finger.

[0017] In the above aspect, it is preferable that the second element has a third electrode and a fourth electrode, and an active layer located between the third electrode and the fourth electrode, the third electrodes of the second elements are connected to each other, and the same potential is applied to the third electrodes of the second elements and the first electrodes of the first elements of the pixel circuits.

[0018] In the above embodiment, it is preferable that the second element has a second light-emitting layer, and that the second light-emitting layer is located between the third electrode and the fourth electrode.

[0019] In the above aspect, it is preferable that the first element has a function of emitting light of one color selected from the three colors of red, green, and blue, and the second element has a function of emitting light of another color selected from the three colors and a function of receiving visible light.

[0020] In the above aspect, it is preferable that the first element has a function of emitting light of one color selected from the three colors of red, green, and blue, and the second element has a function of emitting light of another color selected from the three colors and a function of receiving infrared light.

[0021] In the above aspect, the potential of the first electrode when emitting light with the second luminance is preferably lower than the potential of the first electrode when emitting light with the first luminance.

[0022] In the above aspect, it is preferable that the potential of the first terminal when emitting light with the second luminance is higher than the potential of the first terminal when emitting light with the first luminance.

[0023] Another embodiment of the present invention is an electronic device including a display unit and a camera, in which the display unit includes a plurality of pixel circuits and a plurality of second elements, and the pixel circuit includes a first element and a current control unit, in a first operation mode, the second element receives light that is emitted from the first element and reflected from a subject, the first element emits light at a first luminance when the illuminance of external light is equal to or lower than a first value, and the second element receives light for a first detection period, and when the illuminance of external light is higher than the first value, the first element emits light at a second luminance that is higher than the first luminance, and the second element receives light for a second detection period that is shorter than the first detection period, and in a second operation mode, the first element emits light at a third luminance, and an image is captured using the camera using the light emission at the third luminance as a flashlight, and the third luminance is lower than the second luminance.

[0024] Furthermore, in the above aspect, it is preferable that the first element has a first electrode and a second electrode, and an emitting layer located between the first electrode and the second electrode, the current control unit has a first terminal and a second terminal connected to the second electrode, the first electrodes of the first elements of the plurality of pixel circuits are connected to each other, the first terminals of the current control units of the plurality of pixel electrodes are connected to each other, and the potential difference between the first terminal and the first electrode is larger during emission of the second brightness than during emission of the first brightness, and the potential difference between the first terminal and the first electrode is larger during emission of the second brightness than during emission of the third brightness.

[0025] Another aspect of the present invention is a program for executing an electronic device, the electronic device including a display unit having a display function and a detection function, and a storage unit, the program including a first step of placing a first finger in contact with or in proximity to a surface of the display unit, a second step of displaying a first region of a first image on the display unit at a first luminance, performing detection using the first region of the first image as a light source during a first detection period, and acquiring a first captured image of the first finger, a third step of selecting whether or not to adopt the first captured image, and, if the captured image is not adopted in the third step, displaying the first region of the first image on the display unit at a second luminance higher than the first luminance, and acquiring a first captured image of the first finger using the first region of the first image as a light source during a first detection period. The program includes a fourth step of performing detection in a second detection period that is shorter than the detection period and acquiring a second captured image of the first finger; a fifth step of selecting whether to adopt the second captured image; a sixth step of extracting fingerprint information of the first finger from the first captured image if the captured image is adopted in the third step, and extracting fingerprint information of the first finger from the second captured image if the captured image is adopted in the fifth step; and a seventh step of comparing the fingerprint information of the first finger extracted in the sixth step with fingerprint information of the second finger held in a memory unit; and if the captured image is adopted in the third step, the program proceeds to the sixth step without performing the fourth and fifth steps.

[0026] In the above aspect, the product of the first luminance and the length of the first detection period is preferably 0.8 to 1.2 times the product of the second luminance and the length of the second detection period.

[0027] One embodiment of the present invention provides a display unit, a memory unit, and an illuminance sensor. The display unit includes a plurality of pixel circuits and a plurality of light-receiving elements. The pixel circuit includes a light-emitting element and a current controller. The light-receiving element receives light emitted from the light-emitting element and reflected from a subject. The memory unit holds first biological information. The illuminance sensor detects illuminance corresponding to external light received by the display unit. When the illuminance detected by the illuminance sensor is equal to or lower than a first value, the light-receiving element receives light for a first detection period. When the illuminance detected by the illuminance sensor is equal to or lower than a first value, the light-receiving element emits light at a first luminance during the first detection period. When the illuminance detected by the illuminance sensor is higher than the first value, the light-receiving element receives light for a first detection period. The electronic device has a function of acquiring processing content based on an authentication code and a function of acquiring second biometric information and approving the processing content based on a comparison with the first biometric information, wherein the authentication code is acquired by using an image including the authentication code as a first subject and detecting light reflected from the first subject with multiple light receiving elements, and the second biometric information is acquired by using a finger or palm as a second subject and detecting light reflected from the second subject with multiple light receiving elements.

[0028] In addition, in the above-mentioned aspect, it is preferable that the light-emitting element has a first electrode and a second electrode, and a first light-emitting layer located between the first electrode and the second electrode, the current control unit has a first terminal and a second terminal connected to the second electrode, the first electrodes of the light-emitting elements of each of the multiple pixel circuits are connected to each other, the first terminals of the current control units of each of the multiple pixel circuits are connected to each other, and the difference between the potential of the first terminal and the potential of the first electrode when emitting light at the second brightness is larger than the difference between the potential of the first terminal and the potential of the first electrode when emitting light at the first brightness.

[0029] In the above aspect, it is preferable that the current control unit has a first transistor, one of the source and drain of the first transistor is connected to the first terminal, and the other of the source and drain of the first transistor is connected to the second terminal.

[0030] In the above aspect, it is preferable that the current control unit has a first transistor, and when the light-emitting element emits light, a potential corresponding to the first terminal is applied to one of the source and drain of the first transistor, and the current of the light-emitting element is controlled by the first transistor.

[0031] In the above aspect, the authentication code is preferably a barcode or a two-dimensional code.

[0032] In the above aspect, the product of the first luminance and the length of the first detection period is preferably 0.8 to 1.2 times the product of the second luminance and the length of the second detection period.

[0033] In the above aspect, it is preferable that the light-receiving element has a third electrode, a fourth electrode, and an active layer located between the third electrode and the fourth electrode, the respective third electrodes of the light-receiving element are connected to each other, and the same potential is applied to the respective third electrodes of the light-receiving element and the first electrodes of the respective light-emitting elements of the plurality of pixel circuits.

[0034] In the above aspect, it is preferable that the light-receiving element has a second light-emitting layer, and the second light-emitting layer is located between the third electrode and the fourth electrode.

[0035] In the above aspect, it is preferable that the light-emitting element has a function of emitting light of one color selected from the three colors of red, green, and blue, and the light-receiving element has a function of emitting light of another color selected from the three colors and a function of receiving visible light.

[0036] In the above aspect, it is preferable that the light-emitting element has a function of emitting light of one color selected from the three colors of red, green, and blue, and the light-receiving element has a function of emitting light of another color selected from the three colors and a function of receiving infrared light.

[0037] In the above aspect, the potential of the first electrode when emitting light with the second luminance is preferably lower than the potential of the first electrode when emitting light with the first luminance.

[0038] In the above aspect, it is preferable that the potential of the first terminal when emitting light with the second luminance is higher than the potential of the first terminal when emitting light with the first luminance.

[0039] Another aspect of the present invention is a program to be executed by an electronic device, the electronic device having a display unit having a plurality of light receiving elements and a storage unit, the program including: a first step of displaying an image including an authentication code as a first subject on the display unit at a first luminance using the light source as a light source, and detecting reflected light from the first subject of the light source by the plurality of light receiving elements in a first detection period; a second step of acquiring an image of the authentication code using the reflected light detected in the first step; a third step of displaying first processing content based on the authentication code on the display unit; a fourth step of placing a first finger in contact with or adjacent to the display unit; and a fourth step of displaying the second image including the first finger as a second subject on the display unit at a second luminance using the light source as a light source, the fourth step of detecting reflected light from the first subject of the light source as a light source in a first detection period. a fifth step in which a plurality of light receiving elements detect reflected light from the first finger during a second detection period; a sixth step in which an image of the first finger is acquired using the reflected light detected in the fifth step; a seventh step in which fingerprint information of the first finger is acquired from the image of the first finger and compared with fingerprint information of the second finger stored in a storage unit; and an eighth step in which a match between the fingerprint information of the first finger and the fingerprint information of the second finger is confirmed by the comparison and a first processing content is performed; and the image quality of the image acquired in the sixth step is verified, and if it is determined that the image needs to be acquired again, the fifth step and the sixth step are performed again, and in the second execution of the fifth step, the second luminance is higher and the second detection period is shorter than in the first execution.

[0040] In the above aspect, the product of the first luminance and the length of the first detection period is preferably 0.8 to 1.2 times the product of the second luminance and the length of the second detection period.

[0041] According to one embodiment of the present invention, a display unit having a light detection function can be provided. Alternatively, a high-definition display unit having a light detection function can be provided. Alternatively, a display device having a light detection function can be provided. Alternatively, a high-definition display device having a light detection function can be provided. Alternatively, an electronic device having a display function can be provided. Alternatively, an electronic device having a light detection function can be provided. Alternatively, an electronic device having an authentication function typified by fingerprint authentication can be provided. Alternatively, an electronic device with high security can be provided. Alternatively, an electronic device with high operability can be provided. Alternatively, a multifunctional electronic device can be provided. Alternatively, a novel electronic device can be provided. Alternatively, an electronic device having a high-security authentication method can be provided. Alternatively, an electronic device having a novel operation method can be provided. Alternatively, an electronic device having a novel authentication method can be provided.

[0042] According to another aspect of the present invention, it is possible to provide a program to be executed by a highly secure electronic device, a program to be executed by a new electronic device, or a new program.

[0043] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these can be extracted from the description in the specification, drawings, claims, etc.

[0044] FIG. 1A is a diagram showing an example of the configuration of an electronic device. FIG. 1B is a diagram showing an example of the configuration of an electronic device. FIGS. 1C and 1D are diagrams showing an example of a pixel circuit. FIG. 2 is a diagram showing an example of the operation of an electronic device. FIGS. 3A and 3B are diagrams showing an example of the operation of an electronic device. FIG. 4 is a flowchart showing an example of a method of operating an electronic device. FIGS. 5A and 5B are diagrams showing an example of the operation of an electronic device. FIGS. 6A and 6B are diagrams showing an example of the configuration of a display unit. FIGS. 6C to 6F are diagrams showing an example of the configuration of a pixel. FIGS. 7A and 7B are timing charts showing an example of the operation of an electronic device. FIG. 7C is a diagram showing an example of a pixel circuit. FIG. 8 is a flowchart showing an example of a method of operating an electronic device. FIGS. 9A to 9C are diagrams showing an example of the operation of an electronic device. FIGS. 10A and 10B are diagrams showing an example of the operation of an electronic device. FIG. 11 is a diagram showing an example of the operation of an electronic device. FIGS. 12A to 12D are diagrams showing an example of the configuration of an electronic device. FIGS. 13A to 13D are diagrams showing an example of the configuration of an electronic device. FIGS. 14A to 14C are diagrams showing an example of an electronic device. FIGS. 15A and 15B are diagrams showing configuration examples of electronic devices. FIGS. 16A and 16B are diagrams showing configuration examples of electronic devices. FIGS. 17A and 17B are diagrams showing configuration examples of electronic devices. FIGS. 18A to 18D are diagrams showing configuration examples of electronic devices. FIG. 19A is a diagram showing an example of a subject. FIG. 19B is a diagram showing an example of a configuration of an electronic device. FIG. 19C is a diagram showing an electronic device and a subject. FIG. 20A is a diagram showing an electronic device and a subject. FIGS. 20B and 20C are diagrams showing configuration examples of electronic devices. FIGS. 21A to 21I are diagrams showing examples of pixels. FIGS. 22A and 22B are circuit diagrams showing examples of pixel circuits. FIG. 22C is a timing chart showing an operation example of a pixel circuit. FIG. 23A is a diagram showing an example of a configuration of a display device. FIG. 23B is a circuit diagram showing an example of a pixel circuit. FIGS. 24A to 24C are circuit diagrams showing examples of pixel circuits. FIGS. 25A and 25B are circuit diagrams showing examples of pixel circuits. 26A, 26B, and 26D are cross-sectional views showing examples of a display device. 26C and 26E are diagrams showing examples of images. 26F to 26H are top views showing examples of pixels. 27A is a cross-sectional view showing a configuration example of a display device.27B to 27D are top views showing examples of pixels. FIG. 27E is a diagram showing an example of an image. FIG. 28A is a cross-sectional view showing a configuration example of a display device. FIGS. 28B to 28I are top views showing an example of a pixel. FIGS. 29A to 29F are diagrams showing configuration examples of a light-emitting element. FIGS. 30A and 30B are diagrams showing configuration examples of a light-emitting element and a light-receiving element. FIGS. 31A and 31B are diagrams showing a configuration example of a display device. FIGS. 32A to 32D are diagrams showing a configuration example of a display device. FIGS. 33A to 33C are diagrams showing a configuration example of a display device. FIGS. 34A to 34D are diagrams showing a configuration example of a display device. FIGS. 35A to 35F are diagrams showing a configuration example of a display device. FIGS. 36A to 36F are diagrams showing a configuration example of a display device. FIG. 37 is a diagram showing a configuration example of a display device. FIG. 38A is a cross-sectional view showing an example of a display device. FIG. 38B is a cross-sectional view showing an example of a transistor. FIGS. 39A to 39F are diagrams showing configuration examples of electronic devices.

[0045] Hereinafter, embodiments will be described with reference to the drawings. However, it will be readily understood by those skilled in the art that the embodiments can be implemented in many different ways and that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the following description of the embodiments.

[0046] In the configuration of the invention described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and repeated explanations thereof will be omitted. Furthermore, when referring to similar functions, the same hatching pattern may be used and no particular reference numeral may be assigned.

[0047] In the drawings described in this specification, the size of each component, the thickness of a layer, or an area may be exaggerated for clarity, and therefore, the drawings are not necessarily limited to the scale.

[0048] In this specification, ordinal numbers such as "first" and "second" are used to avoid confusion of components and do not limit the number.

[0049] In the following description, expressions indicating directions such as "upper" and "lower" are basically used in accordance with the directions in the drawings. However, for ease of explanation, the directions indicated by "upper" or "lower" in the specification may not match those in the drawings. For example, when describing the stacking order (or formation order) of a laminate, etc., even if the surface on which the laminate is provided (such as a forming surface, a support surface, an adhesive surface, or a flat surface) is located above the laminate in the drawings, the forming surface may be expressed as being below, and the laminate may be expressed as being above.

[0050] In this specification and the like, a display unit has a function of displaying (outputting) an image or the like on a display surface, and therefore the display unit is one aspect of an output device.

[0051] In this specification and the like, a display panel has a function of displaying (outputting) an image or the like on a display surface, and therefore the display panel is one aspect of an output device.

[0052] In this specification, a display panel having a connector such as an FPC (Flexible Printed Circuit) or a TCP (Tape Carrier Package) attached to its substrate, or having an IC mounted on its substrate using a COG (Chip On Glass) method or the like, may be referred to as a display panel module, a display module, or simply a display panel.

[0053] In this specification and the like, a touch panel has a function of displaying an image or the like on a display surface and a function as a touch sensor that detects when a detectable object such as a finger or a stylus touches, presses, or approaches the display surface. Therefore, a touch panel is one aspect of an input / output device.

[0054] A touch panel can also be called, for example, a display panel (or display device) with a touch sensor or a display panel (or display device) with a touch sensor function. A touch panel can have a configuration including a display panel and a touch sensor panel. Alternatively, the touch panel can have a touch sensor function inside or on the surface of the display panel.

[0055] In this specification, a touch panel substrate on which one or more components selected from a connector, an IC, etc. are mounted may be referred to as a touch panel module, a display module, or simply a touch panel.

[0056] Embodiment 1 In this embodiment, an electronic device of one embodiment of the present invention will be described.

[0057] An electronic device of one embodiment of the present invention includes a display portion that has a function of emitting light and a function of receiving light, and preferably has a function of detecting a touch operation.

[0058] The display unit can display an image. The display unit can also receive light using the displayed image as a light source. For example, the display unit can use the displayed image as a light source to receive light reflected from a subject (object) and obtain information such as the intensity and wavelength of the light.

[0059] The display unit has a plurality of light-emitting elements and a plurality of light-receiving elements, and the plurality of light-emitting elements are preferably arranged in a matrix. The plurality of light-receiving elements are preferably arranged in a matrix.

[0060] A plurality of light receiving elements arranged in a matrix can be used to capture an image of a subject. Light emitting elements can be arranged around each of the plurality of light receiving elements arranged in a matrix. The light receiving elements can receive reflected light emitted from the light emitting elements arranged around them.

[0061] The display unit may also be configured to include a plurality of pixels arranged in a matrix. Each of the plurality of pixels may, for example, include one or more light-emitting elements and light-receiving elements. Each of the plurality of pixels may, for example, include one or more light-emitting elements and one or more light-receiving elements. Alternatively, each of the plurality of pixels may be configured to include only one of a light-emitting element and a light-receiving element. When a pixel includes a plurality of light-emitting elements, the pixel may, for example, include a plurality of light-emitting elements that emit light in different wavelength ranges. When a pixel includes a plurality of light-receiving elements, the pixel may, for example, include a plurality of light-receiving elements that correspond to different wavelength ranges.

[0062] The electronic device may have a sensor unit.

[0063] In the display unit, a portion of the light emitted by the light-emitting element is reflected by the subject, and the reflected light is incident on the light-receiving element. The light-receiving element can output an electrical signal according to the intensity of the incident light. Therefore, by having light-receiving elements arranged in a matrix, the display unit can acquire (also referred to as capturing) data on the position and shape of a subject that touches or is close to the display unit. In other words, the display unit not only has the function of displaying an image, but can also function as an image sensor panel or an optical sensor. Therefore, the display unit is sometimes said to function as part of the sensor unit of the electronic device.

[0064] The sensor portion can include a touch sensor, an illuminance sensor, or the like. The display portion of one embodiment of the present invention can function as an optical sensor, and can detect contact with or proximity to the surface of the display portion by using the optical sensor. Thus, the display portion can be expressed as functioning as a touch sensor.

[0065] The sensor unit may also have a touch sensor that is not included in the display unit.

[0066] The electronic device of one embodiment of the present invention has a function of capturing an image of a subject that touches or is close to the display portion by using a plurality of light-receiving elements arranged in the display portion.

[0067] An electronic device according to one embodiment of the present invention has a function of acquiring authentication information from a captured image.

[0068] Biometric information can be acquired as authentication information. For example, authentication information can be acquired when the subject of an image capture is a finger, a palm, or the like. When the subject is a finger, a fingerprint image can be used as authentication information. When the subject is a palm, a palm print image can be used as authentication information.

[0069] For example, an image including an authentication code can be used as a subject to acquire authentication information based on the authentication code. Examples of authentication codes include barcodes and two-dimensional codes. The authentication information is not limited to these codes. The authentication information can also include character information. The character information can be imaged, and character recognition can be performed in a control circuit of the electronic device to extract character data, and authentication can be performed using the extracted character data.

[0070] Note that the authentication information such as the authentication code may have an area that can be decrypted using a code. The code information can be stored in a storage unit of the electronic device of one embodiment of the present invention, and the authentication information can be read by combining the code with the authentication code when reading the authentication code.

[0071] By including information linked to a user in an area that can be decrypted using a code, personal information can be protected and managed. For improved convenience, authentication information such as an authentication code may also include an area that can be decrypted without using a code. This allows information that is to be widely disclosed, such as information that is widely shared among multiple users and does not contain confidential information such as personal information, to be decrypted without using a code.

[0072] 1A shows a block diagram of an electronic device 420 of one embodiment of the present invention. The electronic device 420 includes a control circuit unit 401, a display unit 422, a sensor unit 403, and a memory unit 404. The control circuit unit 401 includes an authentication unit 407. The display unit 422 includes a light-emitting element 405 and a light-receiving element 406. The electronic device 420 can be used in, for example, a personal digital assistant (PDA).

[0073] In the drawings accompanying this specification, the components are classified by function and shown as independent blocks in the block diagrams, but in reality, it is difficult to completely separate the components by function, and one component may be involved in multiple functions. Also, one function may be realized by multiple components.

[0074] The control circuit unit 401 has a function of performing overall control of the system of the electronic device 420. The control circuit unit 401 also has a function of comprehensively controlling each component included in the electronic device 420. The control circuit unit 401 can be configured to include a scanning line driver circuit and a signal line driver circuit.

[0075] The control circuit unit 401 functions as, for example, a central processing unit (CPU). The control circuit unit 401 performs various data processing or program control by interpreting and executing commands from various programs using a processor. The programs that can be executed by the processor may be stored in a memory area of ​​the processor or may be stored in the storage unit 404.

[0076] The control circuit unit 401 has a function of generating image data to be output to the display unit 422, a function of processing authentication information input from the light receiving element 406 of the display unit 422, a function of controlling the lock state of the electronic device 420, and the like.

[0077] The authentication unit 407 has a function of performing authentication processing using authentication information.

[0078] The display unit 422 has a function of displaying an image using the light-emitting element 405 based on image data input from the control circuit unit 401. The display unit 422 can capture an image of a subject touching the display unit 422 or a subject close to the display unit 422. For example, part of the light emitted by the light-emitting element 405 is reflected by the subject, and the reflected light is incident on the light-receiving element 406. The light-receiving element can output an electrical signal according to the intensity of the incident light. The display unit 422 has a plurality of light-receiving elements 406 arranged in a matrix, so that position information and shape of the subject can be acquired as data (image capture). The display unit 422 can be said to have a function as an image sensor panel or an optical sensor.

[0079] The display unit 422, which has the function of an optical sensor, can acquire information on the color of the light in addition to information on the intensity of the light. Therefore, the display unit 422 can acquire information on the color of the subject. Using the color information can improve the accuracy of authentication and enhance security. When acquiring information on the color of the light, for example, a color filter can be provided on the light receiving element, and the colors corresponding to the color filter can be acquired. Alternatively, in an image used as a light source, light of different wavelengths can be sequentially turned on, and the image data corresponding to each lighting period can be analyzed to acquire information on the color of the light.

[0080] The sensor unit 403 has an illuminance sensor. The illuminance sensor can acquire the intensity of external light illuminating the environment in which the electronic device 420 is used, more specifically, the illuminance of external light illuminating the display unit 422. Furthermore, the illuminance sensor can acquire information such as the color and wavelength of the external light in addition to the illuminance of the external light.

[0081] The sensor unit 403 may also include an ultrasonic sensor, an optical sensor, a capacitance sensor, or the like. These sensors may be used as touch sensors, for example. Information about the subject may also be acquired using these sensors. For example, if the subject is a finger, information about the finger may also be acquired.

[0082] The ultrasonic sensor emits ultrasonic waves and detects the waves reflected by the subject, thereby obtaining three-dimensional information about the contours of the subject. Because ultrasonic waves penetrate skin, if the subject is a human finger, it can detect not only the contours (fingerprint) of the finger but also the blood flow inside the skin. After obtaining a first captured image of the finger's fingerprint as first authentication information using the light-receiving element of the display unit 422, the ultrasonic sensor may obtain a second captured image of the finger's fingerprint as second authentication information. Obtaining authentication information using multiple different methods can enhance security.

[0083] The control circuit unit 401 has a function of performing approved processing when the authentication performed by the authentication unit 407 is approved.

[0084] The authentication unit 407 has a function of locking the system of the electronic device 420. It also has a function of transitioning the system of the electronic device from a locked state to an unlocked state in which the electronic device 420 can be used. Fingerprint authentication can be used for this authentication.

[0085] When fingerprint authentication is performed in the control circuit unit 401, the control circuit unit 401 may have a function to generate image data including an image indicating the position where the user should touch with their finger (also called an image informing the touch position) and output the image data to the display unit 422.

[0086] When the subject to be imaged is a finger, the display unit 422 has a function of acquiring authentication information of the user using the light receiving element 406 and outputting the authentication information to the control circuit unit 401. For example, an image of the fingerprint of the user who touches the display unit 422 (also referred to as an imaged image or imaged data) can be used as the authentication information. The display unit 422 can acquire the authentication information by capturing an image of the fingerprint of the user who touches the display unit 422 using the light receiving element 406.

[0087] Since the display unit 422 having the function of an optical sensor can acquire color information of the subject, color information may be included in the authentication information. For example, if the subject is a finger, skin color information can be acquired as authentication information in addition to fingerprint information.

[0088] The storage unit 404 has a function of storing user information of pre-registered users. For example, the user's fingerprint information can be used as the user information. The storage unit 404 can output the user information to the authentication unit 407 in response to a request from the control circuit unit 401.

[0089] The storage unit 404 can store fingerprint information of the fingers used by the user for authentication, and can freely register information for one or more fingers. For example, it can store fingerprint information for two fingers, one for the index finger of the user's right hand and one for the index finger of the user's left hand. The user can freely register fingerprint information for one or more of the index finger, middle finger, ring finger, little finger, and thumb, in addition to the index finger, and the storage unit 404 can store information for all registered fingerprints.

[0090] The authentication unit 407 has a function of executing a process (authentication process) of comparing authentication information input from the display unit 422 with information held in the storage unit 404 and determining whether or not they match.

[0091] The authentication process can use, for example, a template matching method or a pattern matching method that compares two images and uses the similarity between them. The authentication process can also use a minutia method that compares feature points (minutia) such as the endpoints and bifurcations of the image patterns. The authentication process can also use inference using machine learning. In particular, it is preferable to perform inference using a neural network.

[0092] 1B is a perspective view showing an example of an electronic device 420. The electronic device 420 shown in FIG. 1B has a housing 421 and a display unit 422. The electronic device 420 has a control circuit unit 401, a sensor unit 403, and a storage unit 404 in the housing 421.

[0093] The sensor unit 403 includes an illuminance sensor 432. The illuminance sensor 432 is located, for example, on the surface of the housing 421 on which the display unit 422 is provided or in the vicinity of the surface. The illuminance sensor 432 can detect illuminance corresponding to external light received by the display unit 422.

[0094] The electronic device 420 includes a camera 431. The electronic device 420 has a function of capturing a still image or a moving image using the camera 431 and storing the captured image in a storage unit, a function of displaying the captured image on a display unit, and the like.

[0095] The camera 431 is located, for example, on the surface of the housing 421 on which the display unit 422 is provided or in the vicinity of the surface. The camera 431 may be called an in-camera. The camera 431 preferably includes a wide-angle lens. The camera 431 can be suitably used when capturing an image of a subject that is farther from the display unit 422 than a subject captured using a light receiving element included in the display unit 422.

[0096] An image can be displayed on the display unit 422, and the image can be used as a flashlight to capture an image with the camera 431. FIG. 2 shows an example in which a user 433 displays an image on the display unit 422 of the electronic device 420, uses the image as a flashlight, and captures an image including the user 433 using the camera 431. FIG. 2 shows an example in which an area 483 on the display unit 422 is lit and used as a flashlight. While FIG. 2 shows an example in which the area 483 covers the entire display unit 422, the area 483 may be a partial area of ​​the display unit 422. In the area 483, all pixels may be lit, or a regular pattern such as a houndstooth check or stripes may be displayed. Furthermore, for example, a white display may be used for displaying as a flashlight. Furthermore, when displaying as a flashlight, the color temperature of the displayed color may be set. For example, two or more predetermined color temperatures may be selectable. A redder color temperature may be used as the color temperature, which may make a person's skin color appear more natural, and may be preferable.

[0097] In the electronic device and the display portion of one embodiment of the present invention, the luminance of the light-emitting element may refer to, for example, the average luminance in a region including a plurality of pixels.

[0098] [Pixel Circuit] A pixel has one or more pixel circuits. One pixel circuit includes one light-emitting element. Alternatively, one pixel circuit includes one light-receiving element. Alternatively, one pixel circuit may include one light-emitting element and one light-receiving element. Alternatively, one pixel circuit may include two or more light-emitting elements. Alternatively, one pixel circuit may include two or more light-receiving elements. The pixel circuit shown in FIG. 1C can be widely used for display elements. For example, it may be used for liquid crystal elements. Furthermore, it is not limited to display elements, and may be used for memory elements that retain a state according to data.

[0099] The pixel circuit preferably comprises one or more transistors.

[0100] FIG. 1C shows a pixel circuit PX1 as a pixel circuit including a light-emitting element, and a pixel circuit PX2 as a pixel circuit including a light-receiving element.

[0101] 1C, pixel circuit PX1 has a light-emitting element EM and a current control unit CU. The current control unit CU has a function of controlling the current of the light-emitting element EM. Pixel circuit PX1 also has a signal supply unit SE. The signal supply unit SE has a function of supplying to the current control unit CU a signal based on a scanning signal provided from a line GL and an image signal provided from a line SL. The line GL may be referred to as a scanning line, and the line SL may be referred to as a signal line.

[0102] One terminal of the light-emitting element EM is connected to a wiring CAT. The potential of the wiring CAT is sometimes called a cathode potential.

[0103] One terminal of the current control unit CU is connected to the wiring ANO (the potential of the wiring ANO is sometimes called the anode potential), and the other terminal of the current control unit CU is connected to the other terminal of the light-emitting element EM.

[0104] The current control section has a current control transistor. The current control transistor may also be called a drive transistor. The current control transistor has a function of controlling the current of the light-emitting element EM. By controlling the current of the light-emitting element EM, for example, the brightness of the light-emitting element EM can be controlled.

[0105] The pixel circuit PX2 has a light receiving element IG. One terminal of the light receiving element IG is connected to a line CAT.

[0106] FIG. 1D shows an example of a pixel PX1 in which a transistor M2 is used as a current control unit and a transistor M1 is used as a signal supply unit.

[0107] 1D, one of the source and drain of the transistor M2 is connected to the light-emitting element, but one or more transistors may be interposed between the light-emitting element and one of the source and drain of the transistor M2. Also, in FIG. 1D, the other of the source and drain of the transistor M2 is connected to the wiring ANO, but one or more transistors may be interposed between the transistor M2 and the wiring ANO.

[0108] An example of the operation method of the pixel circuit PX1 will be described. Here, the description will be made using FIG. 1D as an example. First, in a first period, a potential that turns on the transistor M1, for example, a high-level potential, is applied to the wiring GL, and an image signal is applied to the wiring SL, thereby turning on the transistor M1 and applying the image signal to the gate of the transistor M2. At this time, if a reset signal is applied to the other terminal of the light-emitting element EM, the light-emitting element EM can be set to a non-light-emitting state.

[0109] In the subsequent second period, a signal, e.g., a low-level potential, that turns off the transistor M1 is applied to the wiring GL. The gate potential of the transistor M2 is maintained, and a current corresponding to the gate potential of the transistor M2 flows through the light-emitting element EM. In the second period, writing is performed on the next row and thereafter.

[0110] Note that one pixel circuit may have both a light-emitting element and a light-receiving element. In this case, the pixel circuit has a circuit region corresponding to the light-emitting element and a circuit region for controlling the light-receiving element.

[0111] Furthermore, adjacent pixel circuits may share some parts, such as wiring or electrodes.

[0112] In the display portion of one embodiment of the present invention, the transistors included in the pixel circuit PX1 and the transistors included in the pixel circuit PX2 can be provided in the same layer, and the light-emitting element EM and the light-receiving element IG can be provided on the layer where the transistors are provided. With this structure, the heights of the regions where the light-emitting element EM and the light-receiving element IG are arranged can be approximately the same. The shorter distance between the light-emitting element and the light-receiving element can improve the detection performance of the light-receiving element.

[0113] When a configuration having two electrodes (e.g., a lower electrode and an upper electrode) that make a pair and a light-emitting layer located therebetween is used as a light-emitting element, and a configuration having two electrodes (e.g., a lower electrode and an upper electrode) that make a pair and an active layer located therebetween is used as a light-receiving element, one electrode (e.g., the upper electrode) of the light-emitting element and one electrode (e.g., the upper electrode) of the light-receiving element can be a common electrode. The common electrode can be provided across multiple light-emitting elements and multiple light-receiving elements.

[0114] A pixel may include a plurality of sub-pixels, each of which may have a pixel circuit. In this specification and the like, the term "sub-pixel" may refer to a pixel circuit.

[0115] An electronic device according to one embodiment of the present invention includes a circuit for driving a pixel, such as a scan line driver circuit or a signal line driver circuit.

[0116] The display device can be applied to an electronic device according to one embodiment of the present invention. The display device can include, for example, a display portion, a scan line driver circuit, and a signal line driver circuit. The scan line driver circuit and the signal line driver circuit do not necessarily need to be included in the display device. For example, the display device may not include part or all of the signal line driver circuit.

[0117] The display device may include, for example, a touch sensor panel as a touch sensor, but the touch sensor does not necessarily have to be included in the display device.

[0118] <Example 1 of Operation Method> The following describes an example of an operation method of the electronic device 420. Here, the operation of capturing an image of a subject will be described.

[0119] 3A and 3B are schematic diagrams illustrating the operation of the light receiving element detecting light emitted from the display unit 422 and reflected from a subject when the brightness of the external light is different. In each of FIGS. 3A and 3B, an example is shown in which the subject 460 is a user's finger. FIG. 3A illustrates the operation outdoors on a sunny day as an example when the illuminance of the external light is high, and FIG. 3B illustrates the operation under indoor lighting as an example when the illuminance of the external light is lower than that of FIG. 3A.

[0120] 3A, the illuminance of external light is higher than that of FIG. 3B, so it is preferable to further increase the detection sensitivity of the light receiving element. For example, the detection sensitivity can be further increased by increasing the luminance of light emitted from the light emitting element.

[0121] A flowchart relating to the operation of the electronic device 420 is shown in FIG.

[0122] In step S500, the process of this flow starts.

[0123] Next, in step S501, a subject is detected. For example, the electronic device detects that the subject has touched the surface of the display unit or that the subject has been placed close to the surface of the display unit. Alternatively, the subject may not be detected. In that case, for example, in step S501, the electronic device displays instructions for placing the subject on the display unit, and the user places the subject according to the instructions.

[0124] For example, the instruction may include displaying a position image to inform the user of the placement position of the subject.

[0125] Next, in step S502, the number of processing times x (x is an integer equal to or greater than 1) is set to 1, and in step S503, the luminance L of the area used as the light source for imaging and the time t, which is the length of the detection period of the light receiving element 406, are set in the first image to be displayed on the display unit. The length of the detection period of the light receiving element 406 may be expressed as exposure time. The luminance L set here is set to L(1), and the time t is set to t(1).

[0126] Next, in step S503, the area in the first image used as a light source for imaging is displayed on the display unit with a luminance L. Light emitted from the light-emitting element 405 can be used as a light source when imaging is performed by the light-receiving element 406. Therefore, the light emitted by the light-emitting element 405 that is turned on in the area used as a light source for imaging when displaying the first image can be light of a color that can be received by the light-receiving element 406. For example, if the display unit 422 has light-emitting elements 405 of three colors, red (R), green (G), and blue (B), any one, any two, or all three of these light-emitting elements 405 can be turned on.

[0127] In step S503, all of the light-emitting elements 405 of the display unit 422 may be turned on, or only some of the light-emitting elements 405 of the display unit 422 may be turned on. In FIGS. 3A and 3B, an area of ​​the display unit 422 used as a light source for image capture is shown as area 425. FIGS. 3A and 3B show an example in which all of the light-emitting elements 405 of the display unit 422 are turned on as area 425. Area 425 can be used as a light source for image capture. In FIGS. 3A and 3B, the first image can be said to be an image that displays white or a predetermined color across the entire surface of the display unit 422. Area 425 is an area where subject detection is performed in the subsequent step S504, and the user can obtain a captured image by holding the subject over area 425 or by having the subject touch area 425.

[0128] The luminance L may be the luminance in the region 425 .

[0129] When some of the light-emitting elements 405 of the display unit 422 are turned on, that is, when part of the display unit 422 is used as the region 425, the user can capture an image by holding a subject over the region 425 or by bringing the subject into contact with the region 425. The light-emitting elements 405 outside the region 425 may be turned off. Since the light-emitting elements 405 that are turned on in the region 425 are covered by the subject, the user can be prevented from viewing the bright light. For example, in a dark usage environment, if the user directly views the display light of the first image, the user may feel dazzled and there is a risk of the light damaging their eyes. Therefore, by making the region 425 only a part of the display unit, the burden on the user can be reduced. Note that any image may be displayed in a region other than the region 425.

[0130] 5A shows an example in which the light-emitting elements 405 in an area 425 of the display unit 422 are turned on and the other areas are turned off. In FIG. 5A , the first image can be said to be an image in which white or a predetermined color is displayed over the entire area 425 of the display unit 422 and black is displayed in the other areas. Note that instead of black, a color darker than the area 425 may be displayed in the areas other than the area 425. It is preferable that the areas other than the area 425 have lower brightness than the area 425.

[0131] When a pixel has light-emitting elements corresponding to three colors, red (R), green (G), and blue (B), for example, all of the R, G, and B pixels can be lit in the region 425. Alternatively, it is not necessary to light any of the R, G, and B pixels. For example, it is also possible to light a single color, R, G, or B.

[0132] Furthermore, not all pixels in region 425 need to be lit. For example, as shown in FIG. 6A , an image in which lit pixels 30 (hereinafter referred to as pixels 30[w]) and unlit pixels 30 (hereinafter referred to as pixels 30[b]) are arranged in a houndstooth pattern may be displayed in region 425. Alternatively, as shown in FIG. 6B , an image in which pixels 30[w] and pixels 30[b] are arranged in a striped pattern may be displayed in region 425. Alternatively, pixels 30[w] and pixels 30[b] may be arranged randomly. Pixels 30[w] and pixels 30[b] may be arranged so that the light irradiated onto the subject is uniform within a range that does not impair the image quality of the captured image.

[0133] 6C to 6F show lighting states of sub-pixels included in pixel 30. Pixel 30 includes sub-pixel R including a light-emitting element corresponding to red, sub-pixel G including a light-emitting element corresponding to green, sub-pixel B including a light-emitting element corresponding to blue, and sub-pixel PS including a light-receiving element.

[0134] 6C and 6D show examples of the lighting states of the sub-pixels of the pixel 30 (pixel 30[b]) that is turned off in the region 425. Fig. 6C shows an example in which the light-emitting elements corresponding to all colors are turned off and the light-receiving elements are not driven. Fig. 6D shows an example in which the light-emitting elements corresponding to all colors are turned off and the light-receiving elements are driven.

[0135] 6E and 6F show examples of lighting states of sub-pixels of pixel 30 (pixel 30[w]) that are turned on in region 425. Fig. 6E shows an example in which light-emitting elements corresponding to all colors are turned on and the light-receiving element is also driven. Fig. 6F shows an example in which, of all light-emitting elements, only the light-emitting element corresponding to green is turned on and the light-receiving element is also driven.

[0136] 5B shows an example in which the first image is an image in which white or a predetermined color is displayed over the entire area of ​​area 425, and information such as text 481 and an image 482 is displayed in the remaining area. Text 481 can be, for example, a message that prompts the user to place their finger on display unit 422.

[0137] Next, in step S504, the first image is used as a light source to capture an image of the subject. In the image capture, the length of the detection period of the light receiving element 406 is defined as time t. In step S504, the electronic device acquires a captured image of the subject using a signal detected by the light receiving element 406.

[0138] Next, in step S505, it is determined whether or not the captured image acquired in step S504 can be adopted. Specifically, for example, it is determined whether or not the captured image has sufficient image quality for acquiring information about the subject, and if the image quality is sufficient, the image is adopted, and if the image quality is insufficient, the image is not adopted.

[0139] If the captured image is adopted, the process proceeds to step S509; if not, the process proceeds to step S506.

[0140] In step S506, 1 is added to the number of times of processing x (x becomes x+1).

[0141] In step S507, it is determined whether the number of processing times x is smaller than n (n is an integer equal to or greater than 1). If the number of processing times reaches n, the process proceeds to step S511, where the process ends. In step S511, the control circuit unit of the electronic device receives information indicating that the process has ended and information indicating that the capture of the captured image has failed. If the number of processing times has not reached n, the process proceeds to step S508.

[0142] In step S508, the values ​​of the luminance L of the first image displayed on the display unit in step S503 and the time t, which is the length of the detection period of the light receiving element 406, are set again. The luminance L set here is represented as L(x), and the time t is represented as t(x).

[0143] In addition to the light emitted from the light emitting element 405 and reflected from the subject, external light is also incident on the light receiving element 406. The external light can become noise when forming a captured image of the subject. In particular, when the illuminance of the external light is bright as in the example shown in Figure 3A, the noise components in the captured image increase, which may lead to a deterioration in the image quality of the captured image.

[0144] Therefore, when the illuminance of external light is high, it is preferable to increase the luminance of the light emitting element 405 to relatively reduce the noise component.

[0145] In step 508, for example, if the illuminance of external light exceeds a predetermined value, the value of luminance L is set to a value higher than that of the previous process. Furthermore, when luminance L is set to a high value, the intensity of reflected light incident on the light receiving element 406 can also be increased, making it possible to sufficiently detect light even in a shorter detection period. Therefore, luminance L is set to a high value and time t is set to a shorter value.

[0146] For example, when the brightness L is multiplied by A, it is preferable to set the time t to be approximately 1 / A times. In other words, it is preferable to set the brightness L and the time t so that the product of the brightness L and the time t is approximately constant. Here, L(x) is set to A times L(1), and the time t(x) is set to 1 / A times the time t(1).

[0147] The product of the brightness L and the time t can be set to be 0.8 to 1.2 times, or 0.85 to 1.15 times, or 0.9 to 1.1 times the product of the brightness L and the time t in the previous processing.

[0148] After step S508, the process returns to step S503, and steps S503 to S505 are repeated. If the captured image is not adopted in step S505, the process proceeds to step S506, and if the captured image is adopted in step S505, the process proceeds to step S509.

[0149] In step S509, the adopted captured image is acquired, and in step S510, the processing of this flow ends.

[0150] In the electronic device and the display portion of one embodiment of the present invention, the luminance of the light-emitting element may refer to, for example, the average luminance in a region including a plurality of pixels.

[0151] [Setting of Luminance L] The setting of luminance L performed in step S507 will be described.

[0152] The luminance of the light-emitting element EM included in the pixel circuit PX1 shown in Figure 1C is determined, for example, by the potential difference between the wiring ANO and the wiring CAT and the intensity of the image signal provided from the signal supply unit SE to the current control unit CU. The image signal can be a different signal for each pixel. The light-emitting element can emit light at a gradation corresponding to the value of the image signal.

[0153] On the other hand, the wiring ANO and the wiring CAT are each shared by a plurality of pixel circuits, and a common potential is applied to each pixel circuit, so that changing the potential of the wiring ANO or the wiring CAT changes the overall luminance of the shared pixel circuits.

[0154] In applications requiring a large change in brightness, for example, the potential of the wiring CAT or wiring ANO is changed. As an example, if the brightness of the display unit when a user views image information, text information, etc. displayed on the display unit differs significantly from the brightness when capturing an image of a subject, the potential of the wiring CAT or wiring ANO is changed. For example, as shown in FIG. 3A , when capturing an image of a subject using the light-receiving element of the display unit outdoors on a clear day, in step S508, it is preferable to increase the potential difference between the wiring ANO and the wiring CAT by changing the potential of the wiring CAT or wiring ANO from the previous process, thereby increasing the brightness. For example, if the illuminance of light received from external light is equal to or greater than illuminance Q, it is preferable to change the potential of the wiring CAT or wiring ANO, where illuminance Q is, for example, equal to or greater than 1,000 lux and equal to or less than 50,000 lux. The illuminance Q is, for example, 1000 lux (lx) or more and 20000 lux or less, more preferably 1000 lux or more and 10000 lux or less, and even more preferably 1000 lux or more and 5000 lux or less, and can be, for example, about 2000 lux. The lux, which is the unit of illuminance, can also be expressed by the unit symbol lx. Also, lm / m ２It can also be expressed as:

[0155] 3B , under indoor lighting, the potentials of the wirings CAT and ANO do not need to be changed in step S508, and the same conditions can be used, for example. Alternatively, the potential difference between the wirings ANO and CAT can be made smaller than when outdoors on a clear day. In other words, the range of voltage fluctuations in the wirings ANO and CAT can be made smaller.

[0156] Similarly, in an environment where a flashlight is used during image capture as shown in FIG. 2, the illuminance of external light may be lower than, for example, a sunny outdoor environment as shown in FIG. 3A. Even in such a case, the potentials of the wirings CAT and ANO do not need to be changed when displaying an image used as a flashlight. Alternatively, the potential difference between the wirings ANO and CAT can be made smaller than that in a sunny outdoor environment. In other words, the range of voltage fluctuations in the wirings ANO and CAT can be made smaller.

[0157] The luminance of region 425 of display unit 422 when a fingerprint is captured under a first environment (hereinafter, imaging condition Im1), such as outdoors on a sunny day, is higher than the luminance of region 425 of display unit 422 when a fingerprint is captured under a second environment (hereinafter, imaging condition Im2), such as indoor lighting. Also, the luminance of region 483 under a third environment (hereinafter, imaging condition Im3), in which a flashlight is used, is lower than the luminance under imaging condition Im1.

[0158] The luminance of the region 425 under the imaging condition Im1 is, for example, 1.5 times or more, 1.7 times or more, or 2 times or more than the luminance of the region 425 under the imaging condition Im2.

[0159] The luminance of the region 425 under the imaging condition Im1 is, for example, 1.5 times or more, 1.7 times or more, or 2 times or more than the luminance of the region 483 under the imaging condition Im3.

[0160] The potential difference between the wirings ANO and CAT under imaging condition Im1 is, for example, 1.05 times or more, 1.1 times or more, or 1.2 times or more the potential difference between the wirings ANO and CAT under imaging condition Im2 or imaging condition Im3. The potential difference between the wirings ANO and CAT under imaging condition Im2 may be smaller than the potential difference between the wirings ANO and CAT under imaging condition Im3.

[0161] The potential of the wiring CAT under imaging condition Im1 is, for example, lower than the potential of the wiring CAT under imaging condition Im2 and imaging condition Im3. The difference between the potential of the wiring CAT under imaging condition Im1 and the potential of the wiring CAT under imaging condition Im2 or Im3 is, for example, 0.5 to 5 times the potential difference between the gate and source of the current control transistor (drive transistor) of the current control unit CU when the pixel emits light under imaging condition Im2 or Im3. The potential of the wiring CAT under imaging condition Im2 may be greater than the potential difference of the wiring CAT under imaging condition Im3.

[0162] Alternatively, the potential of the wiring ANO under imaging condition Im1 is, for example, lower than the potential of the wiring ANO under imaging condition Im2 and imaging condition Im3. Furthermore, the difference between the potential of the wiring ANO under imaging condition Im1 and the potential of the wiring ANO under imaging condition Im2 or Im3 is, for example, 0.5 to 5 times the potential difference between the gate and source of the current control transistor (drive transistor) of the current control unit CU when the pixel emits light under imaging condition Im2 or Im3. Furthermore, the potential of the wiring ANO under imaging condition Im2 may be smaller than the potential difference of the wiring ANO under imaging condition Im3.

[0163] 7A shows an example in which the potential of the wiring CAT is lowered and the potential difference between the wiring ANO and the wiring CAT is increased when performing the x-th processing of step S502 and step S503, compared to the (x-1)th processing of step S502 and step S503 in the flow shown in Fig. 4. Note that in the x-th processing of step S503, the luminance is increased, so the time t, which is the length of the detection period of the light receiving element 406, is shortened compared to the (x-1)th processing of step S503; however, information corresponding to the detection period of each light receiving element 406 is omitted in Fig. 7A.

[0164] In addition, Figure 7B shows an example in which the potential of wiring ANO is increased and the potential difference between wiring ANO and wiring CAT is increased when processing step S502 and step S503 for the xth time, compared to when processing step S502 and step S503 for the (x-1)th time in the flow shown in Figure 4.

[0165] Here, if the current control transistor in the current control unit CU is a p-channel type, for example, a potential supplied from the wiring ANO is applied to the source of the transistor, and a potential corresponding to an image signal supplied from the signal supply unit SE is applied to the gate of the transistor. Changing the potential of the source of the transistor is undesirable because it changes the potential between the gate and source, which may change the operation of the transistor, specifically, the stability of the saturation current flowing in the transistor's saturation region. Therefore, if the current control transistor is a p-channel type, it is preferable to change the potential of the wiring CAT, as shown in Figure 7A.

[0166] In addition, when the current control transistor of the current control unit CU is an n-channel type, for example, the terminal connected to the light emitting element EM is connected to the source of the transistor, and a potential corresponding to the image signal provided from the signal supply unit SE is provided to the gate of the transistor. When the current control transistor is an n-channel type, it is preferable to change the potential of the wiring ANO as shown in FIG.

[0167] 7C shows a plurality of pixel circuits PX1 and a plurality of pixel circuits PX2 arranged in a matrix. A common signal is applied to the wiring ANO in the plurality of pixel circuits PX1. A common signal is applied to the wiring CAT in the plurality of pixel circuits PX1 and the plurality of pixel circuits PX2.

[0168] The wiring CAT is also connected to a pixel circuit PX2 including a light-receiving element. Therefore, changing the voltage of the wiring CAT also affects the driving conditions of the pixel circuit PX2 that drives the light-receiving element. In such a case, it is preferable to appropriately change the voltage of the signal applied to each wiring in the pixel circuit PX2 in conjunction with changing the wiring CAT.

[0169] On the other hand, since the wiring ANO is not connected to the pixel circuit PX2, there is an advantage that when the luminance of the light-emitting element is changed by changing the wiring ANO, the driving conditions of the pixel circuit PX2 do not need to be taken into consideration.

[0170] <Operation Method Example 2> Hereinafter, an operation example in which authentication is performed in the electronic device of one embodiment of the present invention by applying the above-described operation method example 1 will be described.

[0171] A flowchart relating to the operation of the electronic device 420 is shown in FIG.

[0172] In step S100, the process of this flow starts.

[0173] Next, in step S101, a captured image of the authentication code is acquired. The captured image can be acquired using, for example, a camera provided in the electronic device.

[0174] Next, in step S102, information about the authentication code is obtained from the captured image of the authentication code.

[0175] Next, in step S103, information about processing based on the authentication code is displayed on the display unit. This processing is, for example, processing performed using the electronic device 420. For example, this processing includes approval using the authentication code.

[0176] Next, in step S104, it is determined whether the processing information displayed on the display unit in step S103 is approved. If not approved, the process proceeds to step S199, where the process of this flow ends. If approved, the process proceeds to step S105.

[0177] Steps S105 to S108 are for verifying user information to finalize the approval in step S104. Fingerprint information is used as the user information here.

[0178] First, in step S105, a captured image of the first finger is acquired. By performing the flow shown in FIG. 4 with the first finger as the subject, a captured image of the first finger can be acquired in step S105.

[0179] Next, in step S106, fingerprint information of the first finger is obtained using the captured image obtained in step S105.

[0180] Next, in step S107, the first fingerprint information is compared with the second fingerprint information stored in the storage unit of the electronic device, for example.

[0181] Next, in step S108, it is determined whether the comparison performed in step S107 results in a match. If it is determined that there is a match, the process proceeds to step S109, where the electronic device performs the processing approved in step S104. If it is determined that there is no match, the process proceeds to step S199, where the processing of this flow ends.

[0182] <Operation Method Example 3> By performing the flow shown in FIG. 4 described above with an image including an authentication code as a subject, a captured image of the authentication code can be acquired in step S101 of FIG.

[0183] <Operation Method Example 4> An example of an operation method of one embodiment of the present invention will be described with reference to FIG. 9A.

[0184] In Figure 9A, the first image displayed on display unit 422 is an image that can be used as a light source for imaging in the flow shown in Figure 4, an image that can be used as a flashlight, and an image or video captured using camera 431, displayed in area 425, area 483, and area 484, respectively.

[0185] White or a predetermined color can be displayed in the area 425 and the area 483. The area 425 and the area 483 may display the same color or different colors.

[0186] 9A , the flow shown in FIG. 4 can be performed by placing a finger, which is subject 460, in contact with or close to area 425 and capturing an image. At this time, while the captured image is being captured, area 483 can be used as a flashlight to capture an image of the user using camera 431. A still image or video of the user captured by camera 431 can be displayed in area 484.

[0187] Facial authentication may be performed by capturing an image of the user's face and comparing it with user information stored in a storage unit of the electronic device 420. Security can be enhanced by combining authentication using fingerprint information of the subject 460, which is a finger, with facial authentication.

[0188] It should be noted that, particularly in the case of a still image, the captured image does not need to be displayed in area 484 while image capture is being performed by camera 431. Therefore, for example, as shown in Fig. 9C , area 483 used as a flashlight is displayed while image capture is being performed, and area 484 for displaying the image captured by camera 431 is not displayed, and as shown in Fig. 9B , after image capture, area 483 is not displayed, and area 484 is displayed, thereby making it possible to increase the areas of area 483 and area 484.

[0189] In particular, when the illuminance of external light is low, a flashlight can be used to suitably capture an image of a user. The luminance of region 483 used as a flashlight can be higher than the luminance of region 425 when used to capture fingerprints, for example. For example, the potential of wiring CAT can be lowered. For example, the potential of wiring ANO can be raised. Here, for region 425, the luminance of imaging condition Im2, the driving conditions of the pixel circuit, and the like, described above can be referenced, and for region 483, the luminance of imaging condition Im3, the driving conditions of the pixel circuit, and the like, described above can be referenced.

[0190] Alternatively, when the illuminance of external light is high, it may be possible to refer to the description of the luminance of the imaging condition Im1, the driving conditions of the pixel circuit, and the like for the region 425 as described above.

[0191] <Example 5 of Operation Method> In Fig. 10A , the first image displayed on display unit 422 displays an image that can be used as a light source for image capture in the flow shown in Fig. 4 in region 425 (region 425a and region 425b), and an image or video captured using camera 438 in region 484. Fig. 10B shows electronic device 420 with the surface of housing 421 opposite to the surface shown as the top surface in Fig. 10A as the top surface. Camera 438 is a camera arranged on the surface of housing 421 opposite to the surface on which display unit 422 is provided.

[0192] In area 484, a still image or video is displayed as a captured image of authentication code 485. Also, in FIG. 10A , two areas (area 425a and area 425b) are shown as area 425. Different fingers can be placed on each area. In FIG. 10A , an example is shown in which the user's index finger 460a is placed on area 425a and the user's middle finger 460b is placed on area 425b.

[0193] In the above-described example 3 of the operation method, an example was shown in which an image including an authentication code is acquired in step S101 and then an image of a finger is acquired in step S105 using the flow shown in Fig. 8 , but in the image of the display unit 422 shown in Fig. 10A , for example, both images can be acquired in step S101. Therefore, it may be possible to omit step S105, which is performed later, thereby improving the efficiency of the process.

[0194] <Operation Method Example 6> Fig. 11 shows an example in which the configuration shown in Fig. 9 is combined with the configuration shown in Fig. 10. In Fig. 11, two areas (area 484a and area 484b) are shown as area 484. An image or video captured using camera 438 is displayed in area 484a. A still image or video is displayed as the image of authentication code 485 in area 484b.

[0195] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0196] Embodiment 2 In this embodiment, an example of an electronic device of one embodiment of the present invention will be described.

[0197] 12A to 13D are schematic diagrams of electronic device 420. 12A to 13D are cross-sectional views taken along dashed line A-B in FIG. 3A. 12A to 13D each show a region 425 and a region 427 indicated by arrows.

[0198] The electronic device 420 includes a housing 421, a layer 441, and a layer 443. The layer 441 includes a display portion 422. The layer 443 includes a sensor portion 403. A region 427 overlaps with the layer 443, and detection can be performed using a sensor included in the sensor portion 403. In the example shown in FIG. 3A , an illuminance sensor 432 is provided. Various sensors other than an illuminance sensor can also be provided in the region 427. A control circuit portion 401 and a memory portion 404 can be provided in a space 445 inside the housing 421. Note that the control circuit portion 401 and the memory portion 404 may be provided in the layer 441 or the layer 443. Although not shown, electronic components such as a communication antenna and a storage battery can be provided in the space 445.

[0199] 12A shows an example in which area 425 is provided on the entire surface of display unit 422, and area 427 is provided in a part of display unit 422. In other words, area 425 and area 427 overlap each other. In the configuration shown in FIG. 12A , first authentication information can be obtained at any position on display unit 422.

[0200] 12B shows an example in which the region 425 is provided in a part of the display portion 422 and the region 427 is provided in a part of the display portion 422. By providing the region 425 in a part of the display portion 422, only a part of the light-emitting element 405 is turned on, thereby reducing the power consumption of the electronic device 420. Although Fig. 12B shows a configuration in which the region 425 and the region 427 do not overlap, a configuration in which the region 425 and the region 427 overlap may be used as shown in Fig. 12C.

[0201] 12D shows an example in which area 425 and area 427 are located in the same position. By locating area 425 and area 427 in the same position, the user can obtain the first authentication information and the second authentication information while keeping a finger touching display unit 422, thereby improving the operability of electronic device 420.

[0202] 12A to 12D show a configuration in which an area 427 is provided in the display unit 422, and the second authentication information is acquired within the display unit 422. The layer 443 having the sensor unit 403 is preferably fixed to the layer 441 having the display unit 422. For example, the layer 443 is fixed to the layer 441 by an adhesive layer (not shown). It is also preferable that there is no space between the layer 443 and the layer 441. By employing a configuration in which there is no space (air) between the layer 443 and the layer 441, when a fingerprint sensor using ultrasound is used for the sensor unit 403, it is possible to suppress attenuation of ultrasound due to air, and the second authentication information can be acquired with high sensitivity.

[0203] 13A shows an example in which area 425 is provided on the entire surface of display unit 422, and area 427 is provided outside display unit 422. As shown in Fig. 13B, area 425 may be provided in a part of display unit 422. Figs. 13A and 13B show a configuration in which area 425 and area 427 do not overlap, and the first authentication information and the second authentication information are obtained on the same surface (display surface) as display unit 422 of electronic device 420.

[0204] 13A and 13B show a structure example in which the layer 443 is exposed, but one embodiment of the present invention is not limited to this. The layer 443 may be provided inside the housing 421. In the case where the layer 443 is provided inside the housing 421, the layer 443 is preferably fixed to the housing 421. The layer 443 is fixed to the housing 421 with an adhesive layer (not shown). Furthermore, it is preferable that there be no space between the layer 443 and the housing 421. By providing a structure in which there is no space (air) between the layer 443 and the housing 421, when a fingerprint sensor using ultrasound is used for the sensor portion 403, attenuation of ultrasound due to air can be suppressed, and the second authentication information can be acquired with high sensitivity.

[0205] 13C shows an example in which area 425 is provided on the entire surface of display unit 422, and area 427 is provided on the surface of electronic device 420 facing display unit 422 (surface facing the display surface). As shown in Fig. 13D, area 425 may be provided in a part of display unit 422. Figs. 13C and 13D show a configuration in which first authentication information is acquired on the same surface (display surface) as display unit 422 of electronic device 420, and second authentication information is acquired on the surface facing display unit 422 (surface facing the display surface).

[0206] 13C and 13D , a space (air) may be formed between the layer 443 and the layer 441. Note that although the structure examples in which the layer 443 is exposed are shown in FIGS. 13C and 13D , one embodiment of the present invention is not limited to this structure. The layer 443 may be provided inside the housing 421. When the layer 443 is provided inside the housing 421, the layer 443 is preferably fixed to the housing 421. The layer 443 is fixed to the housing 421 with an adhesive layer (not shown). Furthermore, it is preferable that no space be formed between the layer 443 and the housing 421.

[0207] The above is a description of an example of the configuration of the electronic device.

[0208] Note that the authentication method, processing method, operation method, operation method, display method, etc. executed by the electronic device of one embodiment of the present invention can be described, for example, as a program. For example, a program describing the authentication method, processing method, operation method, operation method, display method, etc. executed by the electronic device 420, etc., exemplified above, can be stored in a non-transitory storage medium and read and executed by an arithmetic device, etc., included in the control circuit unit 401 of the electronic device 420. In other words, a program for causing hardware to execute the authentication method, operation method, etc., exemplified above, and a non-transitory storage medium storing the program are one embodiment of the present invention.

[0209] An electronic device according to an embodiment of the present invention may include one or more of a speaker, a microphone, a camera, or a sensor (including a function of sensing, detecting, or measuring force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared light).

[0210] Electronic components such as a communication antenna and a storage battery can be provided in the internal space of the housing of the electronic device.

[0211] The display unit may have a touch sensor, which may be of various types, such as a capacitance type, a resistive film type, a surface acoustic wave type, an infrared type, an optical type, or a pressure-sensitive type.

[0212] 14A and 14B is a portable information terminal that can be used as a smartphone. In the perspective view of Fig. 14A, a display portion 6502 of the electronic device 6500 faces upward, and in the perspective view of Fig. 14B, a surface of the housing 6501 of the electronic device that is located behind the surface where the display portion 6502 is provided faces upward.

[0213] The electronic device 6500 includes a housing 6501, a display portion 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, a camera 6521, a camera 6522, an illuminance sensor 6523, a light source 6508, and the like. The display portion 6502 has a touch panel function.

[0214] The display portion 422 or the like described above can be applied to the display portion 6502 .

[0215] The display portion 6502, the camera 6507, and the illuminance sensor 6523 are arranged on the side of the housing 421 where the display portion 422 is provided. The cameras 6521, 6522, and the light source 6508 are arranged on the back side thereof.

[0216] The camera 6507 can be used to capture an image of a user. The camera 6507 can be called an in-camera, and the cameras 6521 and 6522 can be called out-cameras.

[0217] In imaging using the camera 6507, for example, a light-emitting element of the display portion 422 can be used as a flashlight. In imaging using the cameras 6521 and 6522, for example, a light source 6508 can be used as a flashlight.

[0218] The electronic device 6500 can have two or more cameras with different focal lengths. For example, the camera 6521 and the camera 6522 are cameras with lenses with different focal lengths. One can be used for wider-angle imaging, and the other can be used for telephoto imaging.

[0219] Furthermore, the cameras 6507, 6521, and 6522 can suitably capture an image of a subject that is farther away than the distance between the subject captured on the display unit 422 and the surface of the display unit.

[0220] The illuminance sensor 6523 is disposed on the side of the housing 421 where the display portion 422 is provided. Therefore, it can detect illuminance corresponding to external light received by the display portion 422. Note that the illuminance sensor 6523 may be disposed on the rear surface side of the housing 421 where the display portion 422 is provided. In this case, external light irradiated onto the display portion 422 passes through the display portion 422 and is irradiated onto the illuminance sensor 6523.

[0221] FIG. 14C is a schematic cross-sectional view including the end of the housing 6501 on the microphone 6506 side.

[0222] A light-transmitting protective member 6510 is provided on the display surface side of the housing 6501, and a display panel 6511, optical members 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are arranged in the space surrounded by the housing 6501 and the protective member 6510.

[0223] A display panel 6511, an optical member 6512, and a touch sensor panel 6513 are fixed to the protective member 6510 by adhesive layers (not shown).

[0224] In a region outside the display portion 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded back part. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

[0225] The display device of one embodiment of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. Furthermore, since the display panel 6511 is extremely thin, the thickness of the electronic device can be reduced and a large-capacity battery 6518 can be mounted thereon. Furthermore, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the display portion, an electronic device with a narrow frame can be realized.

[0226] An image can be captured by the display portion 6502. For example, a fingerprint can be captured by the display panel 6511 and fingerprint authentication can be performed.

[0227] The display portion 6502 further includes a touch sensor panel 6513, which allows the display portion 6502 to have a touch panel function. The touch sensor panel 6513 can use various types such as a capacitive type, a resistive type, a surface acoustic wave type, an infrared type, an optical type, or a pressure-sensitive type. Alternatively, the display panel 6511 may function as a touch sensor, in which case the touch sensor panel 6513 is not necessarily provided.

[0228] <Configuration Example 3 of Electronic Device> An electronic device 420 shown in FIG. 15A can be used as a portable information terminal that can be attached to a living body or an object.

[0229] The electronic device 420 shown in Fig. 15A has a band 435. The band 435 can be used to attach the electronic device to a living body or an object. The electronic device 420 shown in Fig. 15A also has a fastener 437. The fastener 437 can be used to secure the attached band 435 to the living body or an object. In the example shown in Fig. 15A, the electronic device 420 is attached to the left wrist 461 of the user.

[0230] The housing 421 has a first surface and a second surface opposite to the first surface. It is preferable that the display unit 422 is provided on the first surface, and the sensor unit 403 is provided on the second surface. Fig. 17A is a perspective view showing the appearance of the first surface (display unit 422) side of the electronic device 420 shown in Fig. 15A. Fig. 17B is a perspective view showing the appearance of the second surface (sensor unit 403) side of the electronic device 420 shown in Fig. 15A. The sensor unit 403 is provided on the second surface, thereby detecting the attachment / detachment state of the electronic device 420.

[0231] While FIG. 15A shows an example in which the display unit 422 of the electronic device 420 is rectangular, the shape of the display unit 422 is not particularly limited. The design of the electronic device 420 can be enhanced by the display unit 422 having a shape other than rectangular. As shown in FIG. 15B, the display unit 422 may be circular. As shown in FIG. 16A, the display unit 422 may have a curved display surface, and display information along the curved display surface. Furthermore, as shown in FIG. 16B, the electronic device 420 may be cylindrical. FIG. 16B shows how the electronic device 420 is worn on a finger 463.

[0232] The electronic device 420 may have an operation button 436. A user can operate the electronic device 420 by pressing the operation button 436. The electronic device 420 may have a band 435 and a fastener 437. The band 435 and the fastener 437 allow the electronic device 420 to be attached to a living organism or an object. While FIG. 15A and other figures illustrate a configuration in which the electronic device 420 has the operation button 436, the electronic device 420 may not have the operation button 436. Furthermore, while FIGS. 17A and 17B and other figures illustrate a configuration in which the electronic device 420 has the fastener 437, the electronic device 420 may not have the fastener 437. The electronic device 420 may be attached to a living organism or an object using only the band 435. Furthermore, the electronic device 420 may not have the band 435.

[0233] The electronic device 420 can be configured to enable hands-free calling by, for example, communicating with a wireless headset. The electronic device 420 can also transmit data to and receive data from other information terminals via a connection terminal (not shown), and can also be charged. The charging operation may be performed by wireless power supply.

[0234] Figures 18A and 18B are cross-sectional views taken along dashed dotted line A-B in Figure 15A, and Figure 18C is a cross-sectional view taken along dashed dotted line E-F in Figure 15A. Figure 18D is a cross-sectional view taken along dashed dotted line C-D in Figure 16A. Figures 18B to 18D show enlarged views of the housing 421, display unit 422, and sensor unit 403. Note that Figures 18A to 18D omit the operation button 436 and fastener 437.

[0235] The sensor unit 403 can acquire information (first information) about the wearing / detaching state of the electronic device 420 by receiving the reflected light after a portion of the emitted light is reflected by a living body or an object. In FIG. 18B , the light emitted from the display unit 422 and the light emitted from the sensor unit 403 are indicated by arrows. As shown in FIG. 18B , the light emitted from the display unit 422 and the light emitted from the sensor unit 403 are preferably directed in opposite directions. Note that while FIG. 18A shows an example in which the sensor unit 403 is worn on the back of the hand, the method of wearing the electronic device 420 is not limited to this. The sensor unit 403 may also be worn on the palm.

[0236] As shown in FIG. 18D, the display unit 422 may have a curved display surface, and display may be performed along the curved display surface.

[0237] <Example 7 of Operation Method> When a portable information terminal that can be attached to a living body or an object is used as the electronic device 420, an example of performing authentication using a comparison of an authentication code and user information will be described with reference to the examples of operation methods shown in Figures 4 and 8.

[0238] [Capturing an image of an authentication code] First, a method for capturing an image including an authentication code will be described using the operation method shown in Fig. 4. Note that the description of the previous embodiment can be referred to as appropriate below.

[0239] First, in step S500, the process of this flow starts.

[0240] Next, in step S501, the subject 460 is detected.

[0241] In this step, the subject 460 is an image including an authentication code. FIG. 19A shows an example of a piece of paper on which an authentication code is printed. The authentication code can also be attached to objects such as merchandise and fixtures, or to structures such as pillars and walls. The subject 460 may also be displayed on an electronic device. For example, an image of the authentication code may be displayed on a display unit of the electronic device.

[0242] As an example of the detection in this step, after the user brings the display unit 422 of the electronic device 420 closer to the subject 460, the proximity of the subject 460 can be detected using the sensor unit. At this time, a message to start capturing an image of the subject 460 is displayed on the display unit 422 of the electronic device 420, and the user can follow the message and bring the display unit 422 closer to the subject 460. As will be described later, the image may be captured by scanning the display unit 422. In this case, a message to start scanning can be displayed. Note that when such a message is displayed, it is also possible to proceed to the next step without detecting the proximity of the subject 460 after a certain time has elapsed since the message was displayed.

[0243] Next, in step S502, the number of times of processing x is set to 1, the luminance L is set to L(1), and the time t is set to t(1).

[0244] Next, in step S503, the first image is displayed at luminance L on the display unit.

[0245] Next, in step S504, an image of the subject is captured using the first image as a light source. Here, if the image of the authentication code is larger than the display unit 422 of the electronic device 420, the entire image of the authentication code can be captured by scanning the display unit 422. Figures 19B and 19C show the display unit 422, which is placed close to the subject 460, being scanned in the direction of the arrow. In Figure 19C, the electronic device 420 is worn on the user's left wrist 461, with the user's palm facing outward and the housing 421 of the electronic device 420 worn on the back side, i.e., the back of the user's hand. By moving the left wrist 461, the user can scan the display unit 422 and capture the entire image of the authentication code, which is the subject.

[0246] In step S504, the electronic device acquires a captured image of the subject using the signal detected by the light receiving element.

[0247] Next, in step S505, it is determined whether or not the captured image acquired in step S504 can be adopted. Specifically, for example, it is determined whether or not the captured image has sufficient image quality to acquire information about the subject, and if the image quality is sufficient, it is adopted, and if the image quality is insufficient, it is not adopted.

[0248] If the captured image is adopted, the process proceeds to step S509; if not, the process proceeds to step S506.

[0249] In step 506, the number of times of processing x is incremented.

[0250] In step S507, it is determined whether the number of times of processing x is smaller than n. If the number of times of processing has reached n, the process proceeds to step S511, where the process ends.

[0251] In step S508, the luminance L is set to L(x) and the time t is set to t(x).

[0252] After step S508, the process returns to step S503, and steps S503 to S505 are repeated. If the captured image is not adopted in step S505, the process proceeds to step S506, and if the captured image is adopted in step S505, the process proceeds to step S509.

[0253] In step S509, the approved captured image is acquired, and in step S510, the processing of this flow ends.

[0254] [Imaging a Finger] Next, a method for acquiring an image of a user's finger will be described using the operation method shown in Fig. 4. Note that, in the following, the description of the previous embodiment can be referred to as appropriate.

[0255] First, in step S500, the process of this flow starts.

[0256] Next, in step S501, the subject 460 is detected.

[0257] In this step, the subject 460 is the user's finger. Fig. 20A shows, as an example, an example in which the index finger of the user's right hand touches the display unit 422 of the electronic device 420 worn on the user's left wrist 461.

[0258] As an example of the detection in this step, after the user brings the display unit 422 of the electronic device 420 close to the subject 460, the proximity of the subject 460 can be detected using a sensor unit. Alternatively, a message to start capturing an image of the subject 460 can be displayed on the display unit 422 of the electronic device 420, and the user can touch or bring their finger close to the display unit 422 in accordance with the message. When such a message is displayed, for example, it is also possible to proceed to the next step without detecting the proximity of the subject 460 after a certain time has elapsed since the message was displayed.

[0259] Next, in step S502, the number of times of processing x is set to 1, the luminance L is set to L(1), and the time t is set to t(1).

[0260] Next, in step S503, the first image is displayed at luminance L on the display unit.

[0261] Next, in step S504, the electronic device captures an image of the subject using the first image as a light source, and also in step S504, the electronic device acquires a captured image of the subject using a signal detected by the light receiving element.

[0262] Next, in step S505, it is determined whether or not the captured image acquired in step S504 can be adopted. Specifically, for example, it is determined whether or not the captured image has sufficient image quality to acquire information about the subject, and if the image quality is sufficient, it is adopted, and if the image quality is insufficient, it is not adopted.

[0263] If the captured image is adopted, the process proceeds to step S509; if not, the process proceeds to step S506.

[0264] In step 506, the number of times of processing x is incremented.

[0265] In step S507, it is determined whether the number of times of processing x is smaller than n. If the number of times of processing has reached n, the process proceeds to step S511, where the process ends.

[0266] In step S508, the luminance L is set to L(x) and the time t is set to t(x).

[0267] After step S508, the process returns to step S503, and steps S503 to S505 are repeated. If the captured image is not adopted in step S505, the process proceeds to step S506, and if the captured image is adopted in step S505, the process proceeds to step S509.

[0268] In step S509, the adopted captured image is acquired, and in step S510, the processing of this flow ends.

[0269] [Authentication] Next, an example of an operation when authentication is performed using a portable information terminal that can be attached to a living body or an object as an electronic device according to the flow shown in Fig. 8 will be described. Note that, in the following, the description of the previous embodiment can be referred to as appropriate.

[0270] First, in step S100, the process of this flow starts.

[0271] Next, in step S101, a captured image of the authentication code is acquired using the method described above.

[0272] By using a portable information terminal that can be attached to a living body or an object as the electronic device, the user can capture an image of the authentication code simply by moving the part of the body where the electronic device is attached, for example, the wrist in FIG. 19C . This minimizes disruption to the user's work. Furthermore, there is no need to carry the electronic device in a bag, pocket, etc., and there is no need to remove it from a bag, pocket, etc., improving work convenience. By minimizing disruption to work and improving convenience, work safety and work efficiency can be improved.

[0273] Next, in step S102, information about the authentication code is obtained from the captured image of the authentication code.

[0274] Next, in step S103, information about the process based on the authentication code is displayed on the display unit.

[0275] Next, in step S104, it is determined whether the processing information displayed on the display unit in step S103 is approved. If not approved, the process proceeds to step S199, where the process of this flow ends. If approved, the process proceeds to step S105.

[0276] Next, in step S105, a captured image of the first finger is acquired using the method described above.

[0277] By using a portable information terminal that can be attached to a living body or an object as the electronic device, the user does not need to carry the electronic device in a bag, pocket, etc., and there is no need to take it out of the bag, pocket, etc., which improves convenience in work. It also minimizes interference with the user's work. By minimizing interference with work and improving convenience, it is possible to increase work safety and work efficiency.

[0278] Next, in step S106, fingerprint information of the first finger is obtained using the captured image obtained in step S105.

[0279] Next, in step S107, the first fingerprint information is compared with the second fingerprint information stored in the storage unit of the electronic device, for example.

[0280] Next, in step S108, it is determined whether the comparison performed in step S107 results in a match. If it is determined that there is a match, the process proceeds to step S109, where the electronic device performs the processing approved in step S104. If it is determined that there is no match, the process proceeds to step S199, where the processing of this flow ends.

[0281] A sensor that detects the attachment or detachment of the electronic device 420 is provided in the sensor unit, and authentication is performed when the electronic device 420 is removed from the user's wearing location and then put back on, thereby linking the electronic device 420 to the user. The operation performed on the electronic device 420 is, in other words, an operation performed by a terminal that has been previously approved as a first authentication by linking with the user. This can also be expressed as two-step authentication, where the linking with the user when the electronic device 420 is worn is the first-step authentication, and the matching of the fingerprint information in step 107 is the second-step authentication. By using two-step authentication, security can be made extremely high.

[0282] For authentication when the electronic device 420 is worn, authentication methods such as fingerprint authentication, password authentication including PIN authentication, voiceprint authentication, etc. can be used as appropriate.

[0283] 20B is a cross-sectional view taken along dashed dotted line A-B in FIG. 15A , and illustrates an example in which illuminance sensor 434 is provided inside housing 421. Illuminance sensor 434 illustrated in FIG. 20B is provided so as to overlap the rear surface of display unit 422. External light irradiating display unit 422 is incident on illuminance sensor 434 via display unit 422.

[0284] In the example shown in FIG. 20C, the illuminance sensor 434 is disposed on the surface of the housing 421 next to the display unit 422.

[0285] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0286] Embodiment 3 In this embodiment, an example of a display device including a light-receiving element or the like according to one embodiment of the present invention will be described. The display device can be applied to an electronic device according to one embodiment of the present invention.

[0287] In the display device of this embodiment, a pixel can be configured to have a plurality of types of subpixels each having a light-emitting element that emits light of a different color. For example, a pixel can be configured to have three types of subpixels. Examples of the three subpixels include subpixels of three colors: red (R), green (G), and blue (B), and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). Alternatively, a pixel can be configured to have four types of subpixels. Examples of the four subpixels include subpixels of four colors: R, G, B, and white (W), and subpixels of four colors: R, G, B, and Y.

[0288] The arrangement of the sub-pixels is not particularly limited, and various methods can be applied, such as a stripe arrangement, an S-stripe arrangement, a matrix arrangement, a delta arrangement, a Bayer arrangement, and a pentile arrangement.

[0289] Examples of the top surface shape of the sub-pixel include a triangle, a quadrangle (including a rectangle and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, a circle, etc. The top surface shape of the sub-pixel here corresponds to the top surface shape of the light-emitting region of the light-emitting element.

[0290] In a display device having a light-emitting element and a light-receiving element in each pixel, the pixel has a light-receiving function, and therefore it is possible to detect contact or proximity of an object while displaying an image. For example, in addition to displaying an image using all of the sub-pixels of the display device, some of the sub-pixels can emit light as a light source, while other sub-pixels can detect light, and the remaining sub-pixels can display an image.

[0291] The pixels shown in FIGS. 21A, 21B, 21C, 21G, 21H, and 21I have subpixels G, B, R, and PS.

[0292] A stripe arrangement is applied to the pixels shown in Fig. 21A, and a matrix arrangement is applied to the pixels shown in Fig. 21B.

[0293] The pixel array shown in FIG. 21C has a configuration in which three subpixels (subpixel R, subpixel G, and subpixel S) are vertically arranged next to one subpixel (subpixel B).

[0294] 21G shows an example of a pixel arrangement in which subpixels are arranged in two rows: the top row (first row) has three horizontally aligned subpixels (subpixel G, subpixel B, and subpixel R), and the bottom row has one subpixel (subpixel PS).

[0295] 21H shows an example in which subpixels are arranged in three rows: one subpixel (subpixel B) is provided across the first and second rows, and to the left of it, one subpixel (subpixel G) is provided in the first row, one subpixel (subpixel R) is provided in the second row, and one subpixel (subpixel PS) is provided in the third row.

[0296] In the configuration shown in FIG. 21I, two pixels (hereinafter referred to as pixel 30c and pixel 30d) having different configurations are arranged side by side.

[0297] 21I has a subpixel PS in the top row (first row), a subpixel G in the bottom row (second row), and a subpixel R across the first and second rows. In other words, pixel 30c has subpixel PS and subpixel G in the left column (first column), and subpixel R in the right column (second column).

[0298] 21I has subpixel PS in the top row (first row), subpixel G in the bottom row (second row), and subpixel B across rows 1 and 2. In other words, pixel 30d has subpixel PS and subpixel G in the left column (first column), and subpixel B in the right column (second column).

[0299] 21I, subpixels R and B are arranged in every two pixels, and the areas of subpixels R and B are larger than the area of ​​subpixel G. With this configuration, the resolution of subpixels G and PS is increased, and the areas of subpixels R and B are increased, thereby increasing luminance even with lower power consumption, thereby realizing a display device that is high-resolution, low-power-consumption, and highly reliable.

[0300] The light-receiving area of ​​the subpixel PS may be smaller than the light-emitting areas of the other subpixels. The smaller the light-receiving area, the narrower the imaging range, which makes it possible to suppress blurring in the imaging result and improve the resolution. Therefore, by using the subpixel PS, it is possible to perform imaging with high definition or high resolution.

[0301] The pixel shown in FIGS. 21D, 21E, and 21F has a subpixel G, a subpixel B, a subpixel R, a subpixel IRS, and a subpixel PS.

[0302] 21D, 21E, and 21F show an example in which one pixel is arranged in two rows, with three subpixels (subpixel G, subpixel B, and subpixel R) in the upper row (first row) and two subpixels (one subpixel PS and one subpixel IRS) in the lower row (second row).

[0303] In Fig. 21D, three vertically elongated subpixels G, B, and R are arranged horizontally, with a subpixel PS and a horizontally elongated subpixel IRS arranged horizontally below them. In Fig. 21E, two horizontally elongated subpixels G and R are arranged vertically, with a vertically elongated subpixel B arranged horizontally next to them, and a horizontally elongated subpixel IRS and a vertically elongated subpixel PS arranged horizontally below them. In Fig. 21F, three vertically elongated subpixels R, G, and B are arranged horizontally, with a horizontally elongated subpixel IRS and a vertically elongated subpixel PS arranged horizontally below them. Figs. 21E and 21F show cases where the area of ​​the subpixel IRS is the largest and the area of ​​the subpixel PS is approximately the same as that of the subpixels, etc.

[0304] The layout of the sub-pixels is not limited to the configurations shown in FIGS. 21A to 21I.

[0305] Subpixel R has a light-emitting element that emits red light. Subpixel G has a light-emitting element that emits green light. Subpixel B has a light-emitting element that emits blue light. Subpixel IRS has a light-emitting element that emits infrared light. Subpixel PS has a light-receiving element. The wavelength of light detected by subpixel PS is not particularly limited, but it is preferable that the light-receiving element of subpixel PS is sensitive to light emitted by the light-emitting element of subpixel R, subpixel G, subpixel B, or subpixel IRS. For example, it is preferable to detect one or more of light in wavelength ranges such as blue, purple, blue-purple, green, yellow-green, yellow, orange, and red, and light in the infrared wavelength range.

[0306] The light-receiving area of ​​the subpixel PS is smaller than the light-emitting area of ​​the other subpixels. The smaller the light-receiving area, the narrower the imaging range, which makes it possible to suppress blurring in the imaging result and improve resolution. Therefore, by using the subpixel PS, high-definition or high-resolution imaging can be performed. For example, the subpixel PS can be used to capture images for personal authentication using fingerprints, palm prints, irises, pulse patterns (including vein patterns and arterial patterns), faces, etc.

[0307] The subpixel PS can be used as a touch sensor (also called a direct touch sensor) or a near-touch sensor (also called a hover sensor, hover touch sensor, non-contact sensor, or touchless sensor). For example, the subpixel PS preferably detects infrared light, which enables touch detection even in dark places.

[0308] Here, the touch sensor or near-touch sensor can detect the proximity or contact of an object (such as a finger, hand, or pen). The touch sensor can detect an object when the display device and the object are in direct contact with each other. The near-touch sensor can detect an object even if the object does not touch the display device. For example, it is preferable that the display device be configured to detect the object when the distance between the display device and the object is in the range of 0.1 mm to 300 mm, preferably 3 mm to 50 mm. This configuration makes it possible to operate the display device without the object directly touching it, in other words, to operate the display device in a non-contact (touchless) manner. This configuration reduces the risk of the display device becoming dirty or scratched, or makes it possible to operate the display device without the object directly touching dirt (e.g., dust, viruses, etc.) attached to the display device.

[0309] In order to capture high-resolution images, it is preferable that the sub-pixels PS be provided in all pixels of the display device. On the other hand, when used in a touch sensor or near-touch sensor, the sub-pixels PS do not require high accuracy compared to when capturing images of fingerprints, etc., so it is sufficient that the sub-pixels PS are provided in only some of the pixels of the display device. By making the number of sub-pixels PS in the display device smaller than the number of sub-pixels R, etc., the detection speed can be increased.

[0310] FIG. 22A shows an example of a pixel circuit corresponding to a sub-pixel having a light-receiving element, and FIG. 22B shows an example of a pixel circuit corresponding to a sub-pixel having a light-emitting element.

[0311] 22A includes a light receiving element PD, a transistor M11, a transistor M12, a transistor M13, a transistor M14, and a capacitance element C2. Here, an example is shown in which a photodiode is used as the light receiving element PD.

[0312] The anode of the light-receiving element PD is electrically connected to the wiring V1, and the cathode is electrically connected to one of the source and drain of the transistor M11. The gate of the transistor M11 is electrically connected to the wiring TX, and the other of the source and drain is electrically connected to one electrode of the capacitor C2, one of the source and drain of the transistor M12, and the gate of the transistor M13. The gate of the transistor M12 is electrically connected to the wiring RES, and the other of the source and drain is electrically connected to the wiring V2. The transistor M13 has one of the source and drain electrically connected to the wiring V3, and the other of the source and drain is electrically connected to one of the source and drain of the transistor M14. The gate of the transistor M14 is electrically connected to the wiring SEN, and the other of the source and drain is electrically connected to the wiring WX.

[0313] The wiring V1 can be the cathode wiring described in the previous embodiment.

[0314] A constant potential is supplied to the wiring V1, wiring V2, and wiring V3. When the light-receiving element PD is driven with a reverse bias, a potential higher than the potential of the wiring V1 is supplied to the wiring V2. The transistor M12 is controlled by a signal supplied to the wiring RES and has a function of resetting the potential of a node connected to the gate of the transistor M13 to the potential supplied to the wiring V2. The transistor M11 is controlled by a signal supplied to the wiring TX and has a function of controlling the timing at which the potential of the node changes depending on the current flowing through the light-receiving element PD. The transistor M13 functions as an amplifying transistor that outputs according to the potential of the node. The transistor M14 is controlled by a signal supplied to the wiring SEN and functions as a selection transistor that reads the output according to the potential of the node to an external circuit connected to the wiring WX.

[0315] 22B includes a light-emitting element EL, transistors M15, M16, and M17, and a capacitance element C3. Here, an example is shown in which a light-emitting diode is used as the light-emitting element EL. It is particularly preferable to use an organic EL element as the light-emitting element EL.

[0316] In FIG. 22B, transistor M16 can function as a current control unit CU.

[0317] The transistor M15 has a gate electrically connected to a wiring GL, one of its source and drain electrically connected to a wiring SL, and the other of its source and drain electrically connected to one electrode of a capacitor C3 and the gate of a transistor M16. One of the source and drain of the transistor M16 is electrically connected to a wiring V4, and the other is electrically connected to an anode of a light-emitting element EL and one of a source and drain of a transistor M17. The transistor M17 has a gate electrically connected to a wiring MS, and the other of its source and drain is electrically connected to a wiring OUT2. The cathode of the light-emitting element EL is electrically connected to a wiring V5.

[0318] The wiring V4 and wiring V5 can be the anode wiring and cathode wiring described in the previous embodiment, respectively.

[0319] A constant potential is supplied to the wiring V4 and the wiring V5. The anode side of the light-emitting element EL can be set to a high potential, and the cathode side can be set to a lower potential than the anode side. The transistor M15 is controlled by a signal supplied to the wiring GL and functions as a selection transistor for controlling the selection state of the pixel circuit PIX1. The transistor M16 also functions as a drive transistor that controls the current flowing through the light-emitting element EL depending on the potential supplied to its gate. When the transistor M15 is in a conductive state, the potential supplied to the wiring SL is supplied to the gate of the transistor M16, and the light emission brightness of the light-emitting element EL can be controlled depending on the potential. The transistor M17 is controlled by a signal supplied to the wiring MS and has a function of outputting the potential between the transistor M16 and the light-emitting element EL to the outside via the wiring OUT2.

[0320] Here, it is preferable to use transistors that use a metal oxide (oxide semiconductor) in a semiconductor layer in which a channel is formed for the transistors M11, M12, M13, and M14 included in the pixel circuit PIX2, and the transistors M15, M16, and M17 included in the pixel circuit PIX1.

[0321] A transistor using a metal oxide having a wider band gap and a lower carrier concentration than silicon can achieve an extremely small off-state current. Therefore, due to the small off-state current, charge stored in a capacitor connected in series with the transistor can be held for a long period of time. Therefore, it is preferable to use a transistor including an oxide semiconductor for the transistor M11, the transistor M12, and the transistor M15 connected in series with the capacitor C2 or the capacitor C3. Furthermore, by using a transistor including an oxide semiconductor for other transistors as well, manufacturing costs can be reduced.

[0322] Alternatively, the transistors M11 to M17 may be transistors in which silicon is used as a semiconductor in which a channel is formed. In particular, using silicon with high crystallinity, such as single crystal silicon or polycrystalline silicon, is preferable because high field-effect mobility can be achieved and higher-speed operation is possible.

[0323] Alternatively, a structure may be used in which at least one of the transistors M11 to M17 includes an oxide semiconductor and the remaining transistors include silicon.

[0324] Note that although the transistors are shown as n-channel transistors in FIGS. 22A and 22B, p-channel transistors can also be used.

[0325] The transistors of the pixel circuits PIX2 and PIX1 are preferably formed side by side on the same substrate, and in particular, the transistors of the pixel circuits PIX2 and PIX1 are preferably mixed and periodically arranged in one region.

[0326] It is also preferable to provide one or more layers including one or both of a transistor and a capacitor at a position overlapping with the light-receiving element PD or the light-emitting element EL, thereby reducing the effective area occupied by each pixel circuit and realizing a high-definition light-receiving section or display section.

[0327] 23A shows a block diagram of the display device 100. The display device 100 includes a display unit 11, a drive circuit unit 12, a drive circuit unit 13, a drive circuit unit 14, a circuit unit 15, and the like.

[0328] The display unit 11 has a plurality of pixels 30 arranged in a matrix. The pixels 30 have a pixel circuit 21R, a pixel circuit 21G, a pixel circuit 21B, and a pixel circuit 22. The pixel circuit 21R, the pixel circuit 21G, and the pixel circuit 21B each have a light-emitting element that functions as a display element. The pixel circuit 22 has a light-receiving element that functions as a photoelectric conversion element.

[0329] The pixel 30 is electrically connected to a wiring GL, a wiring SLR, a wiring SLG, a wiring SLB, a wiring TX, a wiring SEN, a wiring RES, a wiring WX, etc. The wirings SLR, SLG, and SLB are electrically connected to the driver circuit unit 12. The wiring GL is electrically connected to the driver circuit unit 13. The driver circuit unit 12 functions as a source line driver circuit (also referred to as a source driver). The driver circuit unit 13 functions as a gate line driver circuit (also referred to as a gate driver).

[0330] The pixel 30 has a pixel circuit 21R, a pixel circuit 21G, and a pixel circuit 21B. For example, the pixel circuit 21R can function as a sub-pixel that exhibits red or as a part of a sub-pixel, the pixel circuit 21G can function as a sub-pixel that exhibits green or as a part of a sub-pixel, and the pixel circuit 21B can function as a sub-pixel that exhibits blue or as a part of a sub-pixel. This allows the display device 100 to display full color. Note that, although an example in which the pixel 30 has sub-pixels of three colors is shown here, the pixel 30 may have sub-pixels of four or more colors.

[0331] Pixel circuit 21R has a light-emitting element that emits red light. Pixel circuit 21G has a light-emitting element that emits green light. Pixel circuit 21B has a light-emitting element that emits blue light. Note that pixel 30 may have sub-pixels that have light-emitting elements that emit other light. For example, pixel 30 may have, in addition to the above three sub-pixels, a sub-pixel that has a light-emitting element that emits white light, or a sub-pixel that has a light-emitting element that emits yellow light.

[0332] The wiring GL is electrically connected to the pixel circuits 21R, 21G, and 21B arranged in the row direction (extension direction of the wiring GL). The wiring SLR, wiring SLG, and wiring SLB are electrically connected to the pixel circuits 21R, 21G, and 21B (not shown) arranged in the column direction (extension direction of the wiring SLR, etc.), respectively.

[0333] The pixel circuit 22 of the pixel 30 is electrically connected to a wiring TX, a wiring SEN, a wiring RES, and a wiring WX. The wiring TX, the wiring SEN, and the wiring RES are each electrically connected to the drive circuit unit 14, and the wiring WX is electrically connected to the circuit unit 15.

[0334] The drive circuit unit 14 has a function of generating signals for driving the pixel circuits 22 and outputting them to the pixel circuits 22 via wirings SEN, TX, and RES. The circuit unit 15 has a function of receiving signals output from the pixel circuits 22 via wirings WX and outputting them to the outside as image data. The circuit unit 15 functions as a readout circuit.

[0335] The pixel circuit PIX1 described above can be applied to the pixel circuit 21R, the pixel circuit 21G, and the pixel circuit 21B.

[0336] The pixel circuit 22 can be the pixel circuit PIX2 described above.

[0337] [Example of a Method for Driving a Pixel Circuit] Figure 22C is a timing chart illustrating an example of a method for driving the subpixel PIX2 having the configuration shown in Figure 22A. Here, by setting the potential of the wiring V2 to a potential lower than the potential of the wiring V1, a reverse bias can be applied to the light-receiving element PD. When the potential of the wiring V1 is set to the potential of the wiring V5 of the pixel circuit PIX1, for example, the potential of the cathode wiring, the value of the wiring V2 is set to a potential even lower than the potential of the cathode wiring. Note that in Figure 22B, "H" indicates a high potential, and "L" indicates a low potential. Similar notations are used in other timing charts. Figure 22B shows periods T1 to T5 as periods during which the subpixel PIX2 is driven.

[0338] In the period T1, the potentials of the wiring TX and the wiring RES are set to high potential, and the potential of the wiring SEN is set to low potential. As a result, the transistors M11 and M12 are turned on, and the transistor M14 is turned off. When the transistor M12 is turned on, the potential of the node FD becomes low potential, which is the potential of the wiring V2. Furthermore, when the transistor M11 and the transistor M12 are turned on, the potential of the wiring V2 is also applied to the potential of one electrode of the light-receiving element PD, although this is not shown in FIG. 22A. As a result, the charge accumulated in the capacitor C2 is reset. Therefore, the period T1 can be considered a reset period, and the operation performed in the period T1 can be considered a reset operation.

[0339] In period T2, the potentials of the wiring TX and the wiring RES are set to low. This turns off the transistors M11 and M12. When the light-receiving element PD is irradiated with light in this state, charge corresponding to the energy of the light incident on the light-receiving element PD is accumulated in the light-receiving element PD. Therefore, period T2 can be considered an exposure period, and the operation performed in period T2 can be considered an exposure operation.

[0340] The exposure period shown in period T2 is, for example, the detection period of the light receiving element described in the previous embodiment. Note that when exposure is performed using a light emitting element of the display device, it is preferable that the light emitting element is turned on at least during period T2.

[0341] In the period T3, the potential of the wiring TX is set to a high potential. As a result, the transistor M11 is turned on, and the charge accumulated in the light-receiving element PD is transferred to the node FD. As a result, the potential of the node FD increases. Therefore, the period T3 is a transfer period, and the operation performed in the period T3 can be said to be a transfer operation.

[0342] In the period T4, the potential of the wiring TX is set to a low potential, which turns off the transistor M11 and stops the transfer of the accumulated charge to the node FD.

[0343] As a result, the pixel circuit PIX2 acquires image data. Specifically, the potential of the node FD becomes a potential corresponding to the image data. Therefore, the periods T1 to T4 are acquisition periods, and the operations performed during the periods T1 to T4 are acquisition operations.

[0344] Next, an example of a driving method in the period T5 will be described. During the period T5, the potential of the wiring SEN is set to a high potential. This turns on the transistor M14, and a signal representing the imaging data acquired by the pixel circuit PIX2 is output to the wiring WX. Specifically, the potential of the wiring WX becomes a potential corresponding to the potential of the node FD. This allows the imaging data acquired by the pixel circuit PIX2 to be read out.

[0345] As described above, by supplying a high-potential signal to the wiring SEN, the imaging data acquired by the pixel circuit PIX2 is read out. In other words, the pixel circuit PIX2 from which the imaging data is read can be selected by the signal supplied to the wiring SEN. Therefore, the signal supplied to the wiring SEN can be said to be a selection signal.

[0346] Furthermore, after the imaging data is read out, the potential of the wiring RES is set to a high potential. This turns on the transistor M12, and the imaging data acquired by the pixel circuit PIX2 is reset. Specifically, the potential of the node FD becomes a low potential, which is the potential of the wiring V2. Here, because the transistor M14 is on, the potential of the wiring WX also changes in accordance with the change in the potential of the node FD. Correlated double sampling may be performed in the readout circuit unit electrically connected to the wiring WX. By performing correlated double sampling, noise contained in the readout imaging data can be reduced.

[0347] As described above, the imaging data acquired by the pixel circuit PIX2 is reset by supplying a high-potential signal to the line RES. Therefore, the signal supplied to the line RES can be said to be a reset signal.

[0348] Next, the potential of the wiring RES is set to a low potential to turn off the transistor M12, and the potential of the wiring SEN is set to a low potential to turn off the transistor M14.

[0349] The above is an example of a driving method for the period T5. During the period T5, the imaging data acquired by the pixel circuit PIX2 is read out. Therefore, the period T5 is a readout period, and the operation performed during the period T5 can be said to be a readout operation.

[0350] The pixel circuit PIX2 preferably acquires imaging data using a global shutter system. Here, the global shutter system refers to a system in which imaging data is acquired simultaneously for all pixels. By acquiring imaging data using the global shutter system, it is possible to ensure imaging simultaneity, and therefore it is possible to easily obtain an image with little distortion even when the subject is moving at high speed.

[0351] On the other hand, the reading of imaging data in the pixel circuit PIX2 is performed, for example, row by row. Therefore, when imaging data is acquired by the global shutter system, the period from acquisition to reading of imaging data becomes long in some pixel circuits PIX2. Therefore, when imaging data is acquired by the global shutter system, it is preferable to be able to hold the charge transferred from the pixel circuit PIX2 to the node FD for a long period of time.

[0352] In order to store charge in the node FD for a long period of time, a transistor electrically connected to the node FD is preferably a transistor with low off-state current. An OS transistor can be preferably used as the transistor with low off-state current. The transistors M11 and M12 are preferably OS transistors.

[0353] As long as the off-state current of the transistors M11 and M12 is low, OS transistors may not be used. For example, transistors including a semiconductor with a wide band gap may be used. A wide band gap semiconductor may refer to a semiconductor with a band gap of 2.2 eV or more. Examples of such semiconductors include silicon carbide, gallium nitride, and diamond.

[0354] The transistors M11 and M12 may be transistors having silicon in their channel formation regions (hereinafter referred to as Si transistors). Si transistors have a higher off-state current than OS transistors. However, even if the off-state currents of the transistors M11 and M12 are high, the pixel circuit PIX2 can acquire image data using a global shutter system by increasing the capacitance value of the capacitor C2. The pixel circuit PIX2 may also acquire image data using a rolling shutter system. In this case, even if the transistors M11 and M12 are transistors with a high off-state current, the capacitance value of the capacitor C2 does not need to be increased.

[0355] The transistors M13 and M14 may be Si transistors or OS transistors. For example, when transistors including crystalline silicon (typically, low-temperature polysilicon (LTPS) or single-crystal silicon) are used as the transistors M13 and M14, the on-state current of the transistors M13 and M14 can be increased. Therefore, image data can be read at high speed. On the other hand, when the transistors M11 to M14 are all OS transistors, all the transistors included in the pixel circuit PIX2 can be formed in the same layer. Furthermore, when all the transistors included in the display device, including the transistors M11 to M14, are OS transistors, all the transistors included in the display device can be formed in the same layer. This simplifies the manufacturing process of the display device. Note that the transistors M11 to M14 may be transistors including amorphous silicon in their channel formation regions. Note that a combination of Si transistors (typically, LTPS transistors) and OS transistors may be used as the transistors M11 to M14. Note that a structure in which an LTPS transistor and an OS transistor are combined may be referred to as LTPO. For example, when an OS transistor is used as a transistor that functions as a switch for controlling conduction or non-conduction between wirings and an LTPS transistor is used as a transistor for controlling current, a display device with high display quality can be obtained.

[0356] When fingerprint authentication is performed using a display device according to one embodiment of the present invention, a row driver circuit first selects pixels in a specific row of the display unit and reads out first image data. This allows, for example, the position of a finger in contact with or close to the display unit to be detected. Next, the row driver circuit selects only pixels in the row in contact with or close to the finger and rows surrounding the selected row, and reads out second image data, i.e., the user's fingerprint. This allows the display device according to one embodiment of the present invention to perform fingerprint authentication.

[0357] Here, when reading out the first image data, it is only necessary to detect the position of the finger, and it is not necessary to read out the fingerprint image. Therefore, the first image data does not necessarily need to be read out from all rows and columns of pixels in the display unit. For example, it may be read out from a limited number of pixels every several rows or every several columns. This shortens the readout period per pixel row compared to when the first image data is read out from all pixels in the display unit. On the other hand, when reading out the second image data, it is necessary to read out the fingerprint image from all pixels in a specified area, so the readout period per pixel row is longer than when the first image data is read out. In the display device of one embodiment of the present invention, the pixels from which the second image data is read out for fingerprint authentication can be limited to only a portion of the pixels provided in the display unit. Therefore, fingerprint authentication can be performed in a shorter time than when the second image data is read out from all pixels.

[0358] Furthermore, when a pixel circuit includes a light receiving / emitting element that has both light receiving and light emitting functions, the pixel circuit can include a circuit region used for light receiving and a circuit region used for light emission. Figure 23B shows an example of a pixel circuit including the light receiving / emitting element SR. When exposure is performed on the light receiving / emitting element SR, the transistors M16 and M17 are turned off. By turning off the transistor M16, the electrical connection between the wiring V4, which functions as the anode wiring, and the light receiving / emitting element SR can be cut off. When light is emitted from the light receiving / emitting element SR, for example, a low potential can be applied from the wiring TX to the gate of the transistor M11.

[0359] 24A, 24B, 24C, 25A, and 25B show examples of pixel circuits that can be used as pixel circuit 21R, pixel circuit G, and pixel circuit B. FIG.

[0360] 24A, for example, the transistor 52 and the transistor 54 can function as a current control unit CU of the pixel circuit, and the transistor 54 can function as a drive transistor.

[0361] 24B, for example, the transistor 54 can function as a current control unit CU of the pixel circuit, and can also function as a drive transistor.

[0362] 24C, for example, the transistor 61, the transistor 62, the transistor 63, the transistor 65, and the capacitor 67 can function as a current control unit CU of the pixel circuit. The transistor 63 can also function as a drive transistor.

[0363] In the pixel circuit 23 shown in Fig. 25A, for example, the transistors M2, M3, M4, M5, and the capacitance element C1 can function as a current control unit CU of the pixel circuit. The transistor M3 can also function as a drive transistor. While Fig. 25A shows an example in which p-type channel transistors are used as the transistors, Fig. 25B shows an example in which the transistors M4 and M6 are replaced with n-type channel transistors.

[0364] Note that in the pixel circuit described above, the polarities of the transistors are just an example, and there are cases where an n-channel transistor and a p-channel transistor may be used interchangeably as appropriate.

[0365] The pixel circuit 23 shown in FIG. 24A includes transistors 51 to 54, a capacitor 57, and a capacitor 58.

[0366] A gate of the transistor 51 is electrically connected to a wiring GLa. One of a source and a drain of the transistor 53 is electrically connected to the other of the source and drain of the transistor 52, the other electrode of the capacitor 57, and one electrode of the light-emitting element 60. The other of the source and drain of the transistor 53 is electrically connected to a wiring 48. A gate of the transistor 53 is electrically connected to a wiring GLb.

[0367] The transistor 53 functions as a switch and controls electrical continuity or non-conduction between the wiring 48 and one electrode of the light-emitting element 60 based on the potential of the wiring GLb. For example, a reference potential is supplied to the wiring 48. The reference potential of the wiring 48 supplied via the transistor 53 can suppress variation in the gate-source potential of the transistor 52.

[0368] Furthermore, the wiring 48 can be used to acquire a current value that can be used to set pixel parameters. More specifically, the wiring 48 can function as a monitor line for outputting the current flowing through the transistor 52 or the current flowing through the light-emitting element 60 to the outside of the pixel circuit 23. The current output to the wiring 48 can be converted into a potential by, for example, a source follower circuit, or into a digital signal by, for example, an A-D converter. Note that when the wiring 48 functions as a monitor line, the display device does not need to have a reference potential generating circuit. Furthermore, when the wiring 48 functions as a monitor line, the pixel circuit 23 can be electrically connected to a different wiring 48 for each column.

[0369] An OS transistor is preferably used as the transistor 53. As described above, an OS transistor has higher field-effect mobility than, for example, a transistor using amorphous silicon. Therefore, by using an OS transistor as the transistor 53, a display device can be driven at high speed.

[0370] One of the source and drain of the transistor 52 is electrically connected to one of the source and drain of the transistor 54. The other of the source and drain of the transistor 54 is electrically connected to the wiring ANO. The gate of the transistor 54 is electrically connected to the wiring GLc. One electrode of the capacitor 58 is electrically connected to the other of the source and drain of the transistor 52, one of the source and drain of the transistor 53, the other electrode of the capacitor 57, and one electrode of the light-emitting element 60. The other electrode of the capacitor 58 is electrically connected to the wiring ANO.

[0371] The wiring GLc is electrically connected to the scanning line driver circuit. That is, when the pixel circuit 23 has the configuration shown in Fig. 24A, the wirings GLa, GLb, and GLc are provided as the wirings GL in the display device.

[0372] The transistor 54 functions as a switch and controls conduction or non-conduction between the wiring ANO and one of the source and the drain of the transistor 52 based on the potential of the wiring GLc.

[0373] By turning on the transistor 54, a current having a magnitude corresponding to the gate potential of the transistor 52 flows, for example, from the wiring ANO to the wiring CAT. This causes the light-emitting element 60 to emit light with a luminance corresponding to the gate potential of the transistor 52. On the other hand, by turning off the transistor 54, no current flows through the light-emitting element 60, so that the light-emitting element 60 does not emit light.

[0374] An OS transistor is preferably used as the transistor 54. As described above, an OS transistor has higher field-effect mobility than, for example, a transistor using amorphous silicon. Therefore, by using an OS transistor as the transistor 54, a display device can be driven at high speed.

[0375] The pixel circuit 23 shown in Fig. 24B differs from that shown in Fig. 24A in the connection of the transistor 54. Also, in Fig. 24B, the capacitor 58 is not provided.

[0376] 24B , one of the source and the drain of the transistor 54 is electrically connected to the other of the source and the drain of the transistor 51, the gate of the transistor 52, and one electrode of the capacitor 57. The other of the source and the drain of the transistor 54 is electrically connected to a wiring 49. The gate of the transistor 54 is electrically connected to a wiring GLc. When the pixel circuit 23 has the structure shown in FIG. 24B , a wiring GLa, a wiring GLb, and a wiring GLc are provided as the wiring GL in the display device.

[0377] By turning on the transistor 54, the gate potential of the transistor 52 can be set to the potential of the wiring 49. This can prevent current from flowing through the light-emitting element 60, for example, and can prevent the light-emitting element 60 from emitting light.

[0378] The pixel circuit 23 shown in FIG. 24C includes a transistor 61 , a transistor 62 , a transistor 63 , a transistor 64 , a transistor 65 , a transistor 66 , a capacitor 67 , a capacitor 68 , and a light-emitting element 60 .

[0379] One of the source and the drain of the transistor 61 is electrically connected to the wiring ANO. The other of the source and the drain of the transistor 61 is electrically connected to one of the source and the drain of the transistor 62. The one of the source and the drain of the transistor 62 is electrically connected to one of the source and the drain of the transistor 63. The gate of the transistor 61 is electrically connected to the wiring GLd.

[0380] The other of the source and the drain of the transistor 62 is electrically connected to the gate of the transistor 63. The gate of the transistor 63 is electrically connected to one electrode of the capacitor 67. The gate of the transistor 62 is electrically connected to the wiring GLe.

[0381] One of the source and the drain of the transistor 64 is electrically connected to the wiring SL. The other of the source and the drain of the transistor 64 is electrically connected to the other of the source and the drain of the transistor 63. The other of the source and the drain of the transistor 63 is electrically connected to one of the source and the drain of the transistor 65. The gate of the transistor 64 is electrically connected to the wiring GLf.

[0382] The other of the source and drain of the transistor 65 is electrically connected to one of the source and drain of the transistor 66. The one of the source and drain of the transistor 66 is electrically connected to the other electrode of the capacitor 67. The other electrode of the capacitor 67 is electrically connected to one electrode of the capacitor 68. One electrode of the capacitor 68 is electrically connected to one electrode of the light-emitting element 60. The gate of the transistor 65 is electrically connected to the wiring GLg.

[0383] The other of the source and the drain of the transistor 66 is electrically connected to the wiring 48. The gate of the transistor 66 is electrically connected to the wiring GLe.

[0384] The other electrode of the capacitor 68 is electrically connected to the wiring GLf. The other electrode of the light-emitting element 60 is electrically connected to the wiring CAT.

[0385] The wirings GLd, GLe, GLf, and GLg are electrically connected to a scanning line driver circuit. That is, when the pixel circuit 23 has the configuration shown in FIG. 24C , the wirings GLd, GLe, GLf, and GLg are provided as the wirings GL in the display device.

[0386] The transistors 61, 62, 64, 65, and 66 function as switches. The transistor 61 controls the conduction or non-conduction state between the wiring ANO and one of the source and drain of the transistor 62 and one of the source and drain of the transistor 63, based on the potential of the wiring GLd. The transistor 62 controls the conduction or non-conduction state between the other of the source and drain of the transistor 61 and one of the source and drain of the transistor 63, the gate of the transistor 63, and one electrode of the capacitor 67, based on the potential of the wiring GLe. The transistor 64 controls the conduction or non-conduction state between the wiring SL and the other of the source and drain of the transistor 63 and one of the source and drain of the transistor 65, based on the potential of the wiring GLf. The transistor 65 has a function of controlling, based on the potential of the wiring GLg, electrical continuity or non-conduction between the other of the source and drain of the transistor 63 and the other of the source and drain of the transistor 64 and one electrode of the light-emitting element 60. The transistor 66 has a function of controlling, based on the potential of the wiring GLe, electrical continuity or non-conduction between the wiring ANO and one electrode of the light-emitting element 60.

[0387] OS transistors are preferably used as the transistors 61 to 66. OS transistors have higher field-effect mobility than, for example, transistors using amorphous silicon. Therefore, by using OS transistors as the transistors 61 to 66, a display device can be driven at high speed.

[0388] 25A includes transistors M1 to M7, a capacitor C1, and a light-emitting element EL. The pixel circuit is connected to wirings GL1 to GL4 that function as gate lines, a wiring SL1 that functions as a source line, a wiring VP2 to which a fixed potential is supplied, a wiring ANO that functions as an anode wiring, and a wiring CAT that functions as a cathode wiring.

[0389] The gate of the transistor M1 is connected to a wiring GL2, one of the source and drain is connected to a wiring SL1, and the other of the source and drain is connected to one of the source and drain of the transistor M2 and one of the source and drain of the transistor M3. The gate of the transistor M2 is connected to a wiring GL3, and the other of the source and drain is connected to a wiring ANO. The gate of the transistor M3 is connected to one electrode of the capacitor C1, the other of the source and drain of the transistor M4, and one of the source and drain of the transistor M6, the backgate is connected to the wiring ANO, and the other of the source and drain is connected to one of the source and drain of the transistor M4 and one of the source and drain of the transistor M5. The gate of the transistor M4 is connected to the transistor GL2. The gate of the transistor M5 is connected to a wiring GL3, and the other of the source and drain is connected to one electrode of the light-emitting element EL and one of the source and drain of the transistor M7. The gate of the transistor M6 is connected to the wiring GL1, and the other of the source and drain is connected to the wiring VP2. The gate of the transistor M7 is connected to the wiring GL4, and the other of the source and drain is connected to the wiring VP2. The other electrode of the capacitor C1 is connected to the wiring ANO.

[0390] Although the example in which all of the transistors M1 to M7 are p-channel transistors is shown here, one or more of them may be n-channel transistors. In FIG. 25B, the example in which the transistors M4 and M6 are replaced with n-channel transistors is shown.

[0391] Transistor M3 functions as a drive transistor, and the other transistors function as switches. A p-channel LTPS transistor is preferably used for transistor M3. TG transistors with small parasitic capacitance are preferably used for transistors M4 and M6, which are significantly affected by noise on capacitor C1. Furthermore, vertical transistors or LTPS transistors with large on-current are preferably used for transistors M1, M2, M5, and M7. When using TG transistors and vertical transistors, it is preferable to use n-channel transistors.

[0392] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0393] Embodiment 4 In this embodiment, a light-emitting and receiving device according to one embodiment of the present invention will be described. The light-emitting and receiving device or a part of the light-emitting and receiving device, and the display device or a part of the display device described below can be suitably used in the electronic device described in Embodiment 1. The light-emitting and receiving portion of the light-emitting and receiving device can be applied to, for example, a display portion included in the electronic device according to one embodiment of the present invention.

[0394] A light-emitting and receiving portion of the light-emitting and receiving device of one embodiment of the present invention includes a light-receiving element (also referred to as a light-receiving device) and a light-emitting element. The light-emitting and receiving portion has a function of displaying an image using the light-emitting element. Furthermore, the light-emitting and receiving portion has one or both of a function of capturing an image and a function of sensing using the light-receiving element. Therefore, the light-emitting and receiving device of one embodiment of the present invention can also be expressed as a display device, and the light-emitting and receiving portion can also be expressed as a display portion.

[0395] Alternatively, the light-emitting and receiving device of one embodiment of the present invention may have a structure including a light-emitting and receiving element (also referred to as a light-emitting and receiving device) and a light-emitting element.

[0396] First, a light receiving and emitting device having a light receiving element and a light emitting element will be described.

[0397] A light-emitting and receiving device according to one embodiment of the present invention includes a light-receiving element and a light-emitting element in a light-receiving and light-emitting portion. In the light-emitting and receiving device according to one embodiment of the present invention, the light-emitting and receiving portion includes light-emitting elements arranged in a matrix, and an image can be displayed in the light-emitting and receiving portion. The light-receiving and light-emitting portion also includes light-receiving elements arranged in a matrix, and the light-receiving and light-emitting portion has one or both of an imaging function and a sensing function. The light-emitting and receiving portion can be used as an image sensor, a touch sensor, or the like. That is, by detecting light in the light-emitting and receiving portion, an image can be captured and a touch operation of an object (such as a finger or a pen) can be detected. Furthermore, the light-emitting and receiving device according to one embodiment of the present invention can use the light-emitting element as a light source for a sensor. Therefore, a light-receiving portion and a light source do not need to be provided separately from the light-emitting and receiving device, and the number of components in an electronic device can be reduced.

[0398] In a light-emitting and receiving device of one embodiment of the present invention, when light emitted by a light-emitting element included in the light-emitting and receiving unit is reflected (or scattered) by an object, the light-receiving element can detect the reflected light (or scattered light). This makes it possible to capture images, detect touch operations, and the like even in dark places.

[0399] The light-emitting element included in the light-emitting and receiving device of one embodiment of the present invention functions as a display element (also referred to as a display device).

[0400] As the light-emitting element, it is preferable to use an EL element (also referred to as an EL device) such as an OLED or a QLED. Examples of light-emitting materials contained in the EL element include a fluorescent material (a fluorescent material), a phosphorescent material (a phosphorescent material), and a material exhibiting thermally activated delayed fluorescence (a thermally activated delayed fluorescence (TADF) material). As the light-emitting material contained in the EL element, not only organic compounds but also inorganic compounds (such as quantum dot materials) can be used. Furthermore, LEDs such as micro LEDs can also be used as the light-emitting element.

[0401] A light-receiving and light-emitting device according to one embodiment of the present invention has a function of detecting light using a light-receiving element.

[0402] When the light receiving element is used in an image sensor, the light receiving and emitting device can capture an image using the light receiving element. For example, the light receiving and emitting device can be used as a scanner.

[0403] An electronic device to which the light-emitting and receiving device of one embodiment of the present invention is applied can acquire data related to biometric information such as a fingerprint or palm print by using a function as an image sensor. That is, a biometric authentication sensor can be built into the light-emitting and receiving device. The built-in biometric authentication sensor in the light-emitting and receiving device can reduce the number of components in the electronic device compared to a case in which a biometric authentication sensor is provided separately from the light-emitting and receiving device, thereby enabling the electronic device to be made smaller and lighter.

[0404] Furthermore, when the light receiving element is used as a touch sensor, the light receiving and emitting device can detect a touch operation of an object using the light receiving element.

[0405] The light receiving element may be, for example, a pn-type or pin-type photodiode. The light receiving element functions as a photoelectric conversion element (also called a photoelectric conversion device) that detects light incident on the light receiving element and generates electric charge. The amount of electric charge generated by the light receiving element is determined based on the amount of light incident on the light receiving element.

[0406] In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light-receiving element. Organic photodiodes can be easily made thin, lightweight, and large in area, and have a high degree of freedom in shape and design, making them applicable to a variety of devices.

[0407] In one embodiment of the present invention, an organic EL element (also referred to as an organic EL device) is used as a light-emitting element, and an organic photodiode is used as a light-receiving element. The organic EL element and the organic photodiode can be formed over the same substrate. Therefore, the organic photodiode can be built into a display device using the organic EL element.

[0408] If all layers constituting an organic EL element and an organic photodiode are fabricated separately, the number of film-forming steps becomes enormous. However, since many layers of an organic photodiode can be configured in common with an organic EL element, the increase in the number of film-forming steps can be suppressed by forming the layers that can be configured in common at the same time.

[0409] For example, one of the pair of electrodes (common electrode) can be a layer common to the light-receiving element and the light-emitting element. Furthermore, for example, at least one of the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer can be a layer common to the light-receiving element and the light-emitting element. By having a common layer for the light-receiving element and the light-emitting element in this way, the number of film formations and the number of masks can be reduced, thereby reducing the number of manufacturing steps and manufacturing costs of the light-receiving and light-emitting device. Furthermore, a light-receiving and light-emitting device having a light-receiving element can be manufactured using existing manufacturing equipment and manufacturing methods for display devices.

[0410] Next, a light emitting / receiving device having a light emitting / receiving element and a light emitting / receiving element will be described. Note that the description of the same functions, actions, effects, etc. as those described above may be omitted.

[0411] In the light-emitting and receiving device of one embodiment of the present invention, the subpixels that exhibit one of the colors have light-emitting and light-emitting elements instead of light-emitting elements, and the subpixels that exhibit the other colors have light-emitting elements. The light-emitting and light-emitting elements have both a function of emitting light (light-emitting function) and a function of receiving light (light-receiving function). For example, when a pixel has three subpixels, namely, a red subpixel, a green subpixel, and a blue subpixel, at least one subpixel has a light-emitting and light-emitting element, and the other subpixels have light-emitting elements. Therefore, the light-emitting and receiving portion of the light-emitting and receiving device of one embodiment of the present invention has a function of displaying an image using both the light-emitting and light-emitting elements and the light-emitting elements.

[0412] By using a light-emitting / light-emitting element as both a light-emitting element and a light-receiving element, a pixel can be given a light-receiving function without increasing the number of subpixels included in the pixel. This allows one or both of an imaging function and a sensing function to be added to the light-emitting / receiving portion of the light-emitting / receiving device while maintaining the aperture ratio of the pixel (aperture ratio of each subpixel) and the resolution of the light-emitting / receiving device. Therefore, the light-emitting / receiving device of one embodiment of the present invention can have a higher pixel aperture ratio and can easily achieve higher resolution than a device in which subpixels having light-emitting elements are provided separately from subpixels having light-emitting elements.

[0413] In a light-emitting and receiving device according to one embodiment of the present invention, light-emitting and receiving elements and light-emitting elements are arranged in a matrix in a light-emitting and receiving portion, and an image can be displayed in the light-emitting and receiving portion. The light-emitting and receiving portion can be used for an image sensor, a touch sensor, or the like. The light-emitting and receiving device according to one embodiment of the present invention can use the light-emitting element as a light source for the sensor. Therefore, imaging and detection of touch operations can be performed even in a dark place.

[0414] The light-emitting / receiving element can be fabricated by combining an organic EL element and an organic photodiode. For example, the light-emitting / receiving element can be fabricated by adding an active layer of an organic photodiode to the layered structure of the organic EL element. Furthermore, the light-emitting / receiving element fabricated by combining an organic EL element and an organic photodiode can suppress an increase in the number of film-forming steps by simultaneously forming layers that can have a common configuration with the organic EL element.

[0415] For example, one of the pair of electrodes (common electrode) may be a layer common to the light-emitting and light-emitting elements. Also, for example, at least one of the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer may be a layer common to the light-emitting and light-emitting elements.

[0416] Note that the layers of the light emitting / receiving element may have different functions depending on whether the light emitting / receiving element functions as a light receiving element or a light emitting element. In this specification, the components are referred to based on their functions when the light emitting / receiving element functions as a light emitting element.

[0417] The light emitting and receiving device of this embodiment has a function of displaying an image using a light emitting element and a light emitting and receiving element. That is, the light emitting element and the light emitting and receiving element function as display elements.

[0418] The light emitting and receiving device of this embodiment has a function of detecting light using a light emitting and receiving element, which can detect light having a shorter wavelength than light emitted by the light emitting and receiving element itself.

[0419] When the light emitting and receiving elements are used in an image sensor, the light emitting and receiving device of the present embodiment can capture an image using the light emitting and receiving elements. When the light emitting and receiving elements are used in a touch sensor, the light emitting and receiving device of the present embodiment can detect a touch operation of an object using the light emitting and receiving elements.

[0420] The light-receiving / light-emitting element functions as a photoelectric conversion element. The light-receiving / light-emitting element can be fabricated by adding an active layer of a light-receiving element to the configuration of the light-emitting element. For example, the active layer of a pn-type or pin-type photodiode can be used for the light-receiving / light-emitting element.

[0421] In particular, it is preferable to use an organic photodiode active layer having a layer containing an organic compound as the light-receiving / light-emitting element. Organic photodiodes can be easily made thin, lightweight, and large in area, and have a high degree of freedom in shape and design, making them applicable to a variety of devices.

[0422] A display device, which is an example of a light-emitting and receiving device according to one embodiment of the present invention, will be described in more detail below with reference to the drawings.

[0423] 26A shows a schematic diagram of a display unit 200. The display unit 200 includes a substrate 201, a substrate 202, a light receiving element 212, a light emitting element 211R, a light emitting element 211G, a light emitting element 211B, a functional layer 203, and the like.

[0424] The light-emitting elements 211R, 211G, 211B, and light-receiving element 212 are provided between the substrate 201 and the substrate 202. The light-emitting elements 211R, 211G, and 211B emit red (R), green (G), and blue (B) light, respectively. Note that hereinafter, when there is no need to distinguish between the light-emitting elements 211R, 211G, and 211B, they may be referred to as light-emitting elements 211.

[0425] The display unit 200 has a plurality of pixels arranged in a matrix. Each pixel has one or more sub-pixels. Each sub-pixel has one light-emitting element. For example, a pixel may have three sub-pixels (e.g., three colors of R, G, and B, or three colors of yellow (Y), cyan (C), and magenta (M)), or four sub-pixels (e.g., four colors of R, G, B, and white (W), or four colors of R, G, B, and Y). Each pixel also has a light-receiving element 212. The light-receiving element 212 may be provided in all pixels or in some pixels. Furthermore, one pixel may have multiple light-receiving elements 212.

[0426] 26A shows a state in which finger 220 touches the surface of substrate 202. A portion of the light emitted by light-emitting element 211G is reflected at the contact point between substrate 202 and finger 220. A portion of the reflected light is then incident on light-receiving element 212, making it possible to detect that finger 220 has touched substrate 202. In other words, display unit 200 can function as a touch panel.

[0427] The functional layer 203 has a circuit for driving the light-emitting elements 211R, 211G, and 211B, and a circuit for driving the light-receiving element 212. The functional layer 203 is provided with switches, transistors, capacitors, wiring, and the like. Note that when the light-emitting elements 211R, 211G, and 211B and the light-receiving element 212 are driven by a passive matrix method, a configuration without switches, transistors, and the like may be used.

[0428] It is preferable that the display unit 200 has a function of detecting the fingerprint of a finger 220. Fig. 26B is a schematic enlarged view of a contact portion when the finger 220 is in contact with the substrate 202. Fig. 26B also shows light-emitting elements 211 and light-receiving elements 212 arranged alternately.

[0429] A fingerprint is formed by concave and convex portions of the finger 220. Therefore, the convex portions of the fingerprint are in contact with the substrate 202 as shown in FIG.

[0430] Light reflected from a surface, interface, etc. can be classified as specular reflection or diffuse reflection. Specular reflection is highly directional light, with the angle of incidence and the angle of reflection matching, while diffuse reflection is low-directional light, with low angular dependence of intensity. The diffuse reflection component is dominant in the light reflected from the surface of the finger 220. On the other hand, the specular reflection component is dominant in the light reflected from the interface between the substrate 202 and the atmosphere.

[0431] The intensity of light reflected by the contact or non-contact surface between the finger 220 and the substrate 202 and incident on the light receiving element 212 located directly below them is the sum of specularly reflected light and diffusely reflected light. As described above, at the concave portions of the finger 220, the substrate 202 and the finger 220 do not come into contact, so specularly reflected light (indicated by the solid arrows) is dominant, whereas at the convex portions, they come into contact, so diffusely reflected light (indicated by the dashed arrows) from the finger 220 is dominant. Therefore, the intensity of light received by the light receiving element 212 located directly below the concave portions is higher than that of the light receiving element 212 located directly below the convex portions. This makes it possible to capture an image of the fingerprint of the finger 220.

[0432] A clear fingerprint image can be obtained by arranging the light receiving elements 212 at an interval smaller than the distance between two convex portions of a fingerprint, preferably the distance between adjacent convex and concave portions. Since the distance between convex and concave portions of a human fingerprint is approximately 200 μm, the interval between the light receiving elements 212 is, for example, 400 μm or less, preferably 200 μm or less, more preferably 150 μm or less, even more preferably 100 μm or less, and even more preferably 50 μm or less, and is 1 μm or more, preferably 10 μm or more, and more preferably 20 μm or more.

[0433] Fig. 26C shows an example of a fingerprint image captured by display unit 200. In Fig. 26C, the outline of finger 220 is indicated by a dashed line and the outline of contact area 221 is indicated by a dashed line within image capture area 223. Within contact area 221, a fingerprint 222 with high contrast can be captured due to differences in the amount of light incident on light receiving element 212.

[0434] As shown in Fig. 27E, a palm is placed in an imaging range 223 so that a palm print 222b of the palm 220b is captured.

[0435] Note that the configuration illustrated in FIG. 26A and other figures illustrates an example in which a light-emitting element functioning as a display panel and a light-receiving element functioning as a sensor capable of reading fingerprints, palm prints, and the like are arranged on the substrate 201. However, the light-emitting element and the sensor capable of reading fingerprints, palm prints, and the like do not necessarily need to be formed on the same plane. For example, the sensor capable of reading fingerprints, palm prints, and the like may be arranged below the display unit. For example, an IC chip equipped with a sensor capable of reading fingerprints, palm prints, and the like may be arranged below the display unit. However, in such a case, compared to when the display unit itself functions as a sensor, as in the display unit of one embodiment of the present invention, providing the sensor separately from the display unit increases the volume occupied within the housing. Therefore, the degree of freedom in arranging the sensor within the housing is reduced. Furthermore, if the area of ​​the sensor is limited, the number of fingers that can be read is also limited.

[0436] In the electronic device of one embodiment of the present invention, the display unit itself functions as a sensor, so that fingerprints, palm prints, and the like can be read at any position on the display unit. Therefore, the area to be read on the display unit can be freely shaped, such as vertically or horizontally, and reading can be suitably performed at an appropriate position with any number of fingers, etc.

[0437] The display unit 200 can also function as a touch sensor or a pen tablet. Fig. 26D shows a state in which the tip of a stylus 225 is in contact with the substrate 202 and is slid in the direction of the dashed arrow.

[0438] As shown in Figure 26D, the diffuse reflected light scattered by the tip of the stylus 225 and the contact surface of the substrate 202 is incident on the light receiving element 212 located at the part overlapping with the contact surface, thereby enabling the position of the tip of the stylus 225 to be detected with high accuracy.

[0439] 26E shows an example of a trajectory 226 of the stylus 225 detected by the display unit 200. The display unit 200 is capable of detecting the position of a detectable object such as the stylus 225 with high positional accuracy, and therefore is also capable of performing high-resolution drawing in drawing applications, etc. Furthermore, unlike when a capacitive touch sensor, an electromagnetic induction touch pen, or the like is used, the position of even a highly insulating detectable object can be detected, and therefore the material of the tip of the stylus 225 is not a factor, and various writing implements (e.g., a brush, a glass pen, a feather pen, etc.) can be used.

[0440] 26F to 26H show examples of pixels that can be used in the display unit 200. FIG.

[0441] 26F and 26G each have a red (R) light-emitting element 211R, a green (G) light-emitting element 211G, a blue (B) light-emitting element 211B, and a light-receiving element 212. The pixel has a pixel circuit for driving the light-emitting element 211R, the light-emitting element 211G, the light-emitting element 211B, and the light-receiving element 212, respectively.

[0442] Fig. 26F shows an example in which three light-emitting elements and one light-receiving element are arranged in a 2 x 2 matrix, while Fig. 26G shows an example in which three light-emitting elements are arranged in a row, with one horizontally long light-receiving element 212 arranged below them.

[0443] 26H is an example of a pixel having a white (W) light-emitting element 211W. Here, four light-emitting elements are arranged in a row, and a light-receiving element 212 is arranged below them.

[0444] The pixel configuration is not limited to the above, and various arrangement methods can be adopted.

[0445] [Configuration Example 1-2] Hereinafter, a configuration example including a light-emitting element that emits visible light, a light-emitting element that emits infrared light, and a light-receiving element will be described.

[0446] The display unit 200A shown in Fig. 27A has a light-emitting element 211IR in addition to the configuration exemplified in Fig. 26A. The light-emitting element 211IR is a light-emitting element that emits infrared light IR. In this case, it is preferable to use an element that can receive at least the infrared light IR emitted by the light-emitting element 211IR as the light-receiving element 212. It is more preferable to use an element that can receive both visible light and infrared light as the light-receiving element 212.

[0447] As shown in FIG. 27A, when a finger 220 touches the substrate 202, the infrared light IR emitted from the light-emitting element 211IR is reflected by the finger 220, and a portion of the reflected light is incident on the light-receiving element 212, thereby obtaining position information of the finger 220.

[0448] 27B to 27D show examples of pixels applicable to the display unit 200A.

[0449] Fig. 27B shows an example in which three light-emitting elements are arranged in a row, and below them, light-emitting element 211IR and light-receiving element 212 are arranged side by side. Fig. 27C shows an example in which four light-emitting elements including light-emitting element 211IR are arranged in a row, and below them, light-receiving element 212 is arranged.

[0450] FIG. 27D shows an example in which three light-emitting elements and a light-receiving element 212 are arranged on all four sides with the light-emitting element 211IR at the center.

[0451] In the pixels shown in FIGS. 27B to 27D, the positions of the light-emitting elements and the light-emitting elements and the light-receiving elements can be interchanged.

[0452] [Configuration Example 1-3] Hereinafter, a configuration example including a light-emitting element that emits visible light and a light-receiving / light-emitting element that emits visible light and receives visible light will be described.

[0453] The display unit 200B shown in Fig. 28A has a light-emitting element 211B, a light-emitting element 211G, and a light-receiving / light-emitting element 213R. The light-receiving / light-emitting element 213R functions as a light-emitting element that emits red (R) light and as a photoelectric conversion element that receives visible light. Fig. 28A shows an example in which the light-receiving / light-emitting element 213R receives green (G) light emitted by the light-emitting element 211G. The light-receiving / light-emitting element 213R may also receive blue (B) light emitted by the light-emitting element 211B. The light-receiving / light-emitting element 213R may also receive both green light and blue light.

[0454] For example, it is preferable that the light receiving / emitting element 213R receives light with a shorter wavelength than the light it emits. Alternatively, the light receiving / emitting element 213R may be configured to receive light with a longer wavelength than the light it emits (e.g., infrared light). The light receiving / emitting element 213R may be configured to receive light with a wavelength similar to the light it emits, but in that case, it may also receive the light it emits, which could reduce the light emission efficiency. Therefore, it is preferable that the light receiving / emitting element 213R is configured so that the peak of the emission spectrum and the peak of the absorption spectrum do not overlap as much as possible.

[0455] In addition, the light emitted by the light emitting / receiving element is not limited to red light. Furthermore, the light emitted by the light emitting element is not limited to a combination of green light and blue light. For example, the light emitting / receiving element may be an element that emits green or blue light and receives light of a wavelength different from the light it emits.

[0456] In this way, by having the light emitting / receiving element 213R function as both a light emitting element and a light receiving element, the number of elements arranged in one pixel can be reduced, which makes it easier to achieve higher definition, a higher aperture ratio, and higher resolution.

[0457] 28B to 28I show examples of pixels that can be applied to the display unit 200B.

[0458] Fig. 28B shows an example in which the light emitting / receiving element 213R, the light emitting element 211G, and the light emitting element 211B are arranged in a row. Fig. 28C shows an example in which the light emitting element 211G and the light emitting element 211B are arranged alternately in the vertical direction, and the light emitting / receiving element 213R is arranged next to them.

[0459] FIG. 28D shows an example in which three light-emitting elements (light-emitting element 211G, light-emitting element 211B, and light-emitting element 211X) and one light-receiving / light-emitting element are arranged in a 2×2 matrix. The light-emitting element 211X is an element that emits light other than R, G, and B. Examples of light other than R, G, and B include white (W), yellow (Y), cyan (C), magenta (M), infrared light (IR), and ultraviolet light (UV). When the light-emitting element 211X emits infrared light, the light-receiving / light-emitting element preferably has a function to detect infrared light or a function to detect both visible light and infrared light. The wavelength of light detected by the light-receiving / light-emitting element can be determined depending on the application of the sensor.

[0460] FIG. 28E shows two pixels. An area including three elements surrounded by dotted lines corresponds to one pixel. Each pixel has a light-emitting element 211G, a light-emitting element 211B, and an optical element 213R. In the left pixel shown in FIG. 28E, the light-emitting element 211G is arranged in the same row as the optical element 213R, and the light-emitting element 211B is arranged in the same column as the optical element 213R. In the right pixel shown in FIG. 28E, the light-emitting element 211G is arranged in the same row as the optical element 213R, and the light-emitting element 211B is arranged in the same column as the optical element 211G. In the pixel layout shown in FIG. 28E, the optical element 213R, the light-emitting element 211G, and the light-emitting element 211B are arranged repeatedly in both odd and even rows, and in each column, optical elements or optical elements emitting light of different colors are arranged in the odd and even rows.

[0461] Figure 28F shows four pixels to which the Pentile arrangement is applied, with two adjacent pixels having light-emitting or light-receiving elements that emit light of two different colors. Note that Figure 28F shows the top view of the light-emitting or light-receiving element.

[0462] The upper left pixel and lower right pixel shown in Fig. 28F have a light emitting / receiving element 213R and a light emitting element 211G. The upper right pixel and lower left pixel have a light emitting element 211G and a light emitting element 211B. That is, in the example shown in Fig. 28F, a light emitting element 211G is provided in each pixel.

[0463] The top surface shapes of the light-emitting element and the light-receiving / light-emitting element are not particularly limited and may be circular, elliptical, polygonal, polygonal with rounded corners, etc. Figure 28F etc. shows an example in which the top surface shapes of the light-emitting element and the light-receiving / light-emitting element are squares (diamonds) tilted at approximately 45 degrees. Note that the top surface shapes of the light-emitting element and the light-receiving / light-emitting element for each color may be different from each other, or may be the same for some or all of the colors.

[0464] In addition, the sizes of the light-emitting regions (or light-receiving regions) of the light-emitting elements and light-receiving / light-emitting elements of each color may be different from one another, or may be the same for some or all of the colors. For example, in Figure 28F, the area of ​​the light-emitting region of the light-emitting element 211G provided in each pixel may be smaller than the light-emitting regions (or light-receiving / light-emitting regions) of the other elements.

[0465] Fig. 28G is a modified example of the pixel array shown in Fig. 28F. Specifically, the configuration of Fig. 28G can be obtained by rotating the configuration of Fig. 28F by 45 degrees. Although Fig. 28F has been described as having two elements per pixel, it can also be understood that one pixel is made up of four elements, as shown in Fig. 28G.

[0466] Fig. 28H is a modified example of the pixel array shown in Fig. 28F. The upper left pixel and lower right pixel shown in Fig. 28H have light-emitting / receiving elements 213R and light-emitting elements 211G. The upper right pixel and lower left pixel have light-emitting / receiving elements 213R and light-emitting elements 211B. That is, in the example shown in Fig. 28H, each pixel is provided with a light-emitting / receiving element 213R. Because each pixel is provided with a light-emitting / receiving element 213R, the configuration shown in Fig. 28H can capture images with higher resolution than the configuration shown in Fig. 28F. This can improve the accuracy of biometric authentication, for example.

[0467] FIG. 28I is a modified example of the pixel array shown in FIG. 28H, and is obtained by rotating the pixel array by 45 degrees.

[0468] In FIG. 28I, a pixel is assumed to be composed of four elements (two light-emitting elements and two light-receiving and light-emitting elements). In this way, a single pixel can capture images with high resolution by including multiple light-receiving and light-emitting elements with light-receiving capabilities. This improves the accuracy of biometric authentication. For example, the image resolution can be set to the root double of the display resolution.

[0469] A display device to which the configuration shown in Figure 28H or 28I is applied has p (p is an integer of 2 or more) first light-emitting elements, q (q is an integer of 2 or more) second light-emitting elements, and r (r is an integer greater than p and greater than q) light-receiving and light-emitting elements. p and r satisfy r = 2p. Furthermore, p, q, and r satisfy r = p + q. One of the first light-emitting elements and the second light-emitting element emits green light, and the other emits blue light. The light-receiving and light-emitting element emits red light and has a light-receiving function.

[0470] For example, when detecting a touch operation using a light-emitting / receiving element, it is preferable that the light emitted from the light source is less visible to the user. Because blue light is less visible than green light, it is preferable that a light-emitting element that emits blue light be used as the light source. Therefore, it is preferable that the light-emitting / receiving element has a function of receiving blue light. However, this is not limited to this, and the light-emitting element used as the light source can be appropriately selected depending on the sensitivity of the light-emitting / receiving element.

[0471] As described above, pixels with various arrangements can be applied to the display device of this embodiment mode.

[0472] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0473] Embodiment 5 In this embodiment, a light-emitting element and a light-receiving element that can be used for a light-emitting and receiving device which is one embodiment of the present invention will be described.

[0474] In this specification, etc., a device fabricated using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. Also, in this specification, etc., a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless) structure.

[0475] In this specification and the like, a structure in which different light-emitting layers are created for light-emitting elements of each color (here, blue (B), green (G), and red (R)) or in which different light-emitting layers are painted may be referred to as an SBS (Side By Side) structure. In this specification and the like, a light-emitting element that can emit white light may be referred to as a white light-emitting element. In addition, by combining a white light-emitting element with a colored layer (for example, a color filter), a light-emitting device and electronic device having a display unit for full-color display can be realized.

[0476] [Light-emitting element] Furthermore, light-emitting elements can be broadly divided into single structures and tandem structures. A single-structure device has one light-emitting unit between a pair of electrodes, and the light-emitting unit preferably includes one or more light-emitting layers. To obtain white light emission with a single structure, white light emission can be obtained by selecting light-emitting layers that can produce white light through the emission of each of two or more light-emitting layers. For example, in the case of two colors, a configuration in which the emission color of the first light-emitting layer and the emission color of the second light-emitting layer are complementary colors can be obtained, thereby obtaining a configuration in which the light-emitting element as a whole emits white light. Furthermore, when white light emission is obtained using three or more light-emitting layers, white light emission can be obtained by using a configuration in which the emission colors of the three or more light-emitting layers are combined to produce white light emission as a whole light-emitting device.

[0477] A tandem-structure device preferably has two or more light-emitting units between a pair of electrodes, each of which includes one or more light-emitting layers. By using light-emitting layers that emit light of the same color in each light-emitting unit, the luminance per given current can be increased, and a light-emitting device with higher reliability than a single-structure device can be obtained. To obtain white light emission in a tandem structure, white light can be obtained by combining light from the light-emitting layers of multiple light-emitting units. The combination of light-emitting colors that can produce white light is the same as in the single-structure device. In a tandem-structure device, it is preferable to provide an intermediate layer, such as a charge-generating layer, between the multiple light-emitting units.

[0478] Furthermore, when the above-described white light-emitting element (single structure or tandem structure) is compared with a light-emitting element having an SBS structure, the light-emitting element having an SBS structure can reduce power consumption compared to the white light-emitting element. When it is desired to reduce power consumption, it is preferable to use a light-emitting element having an SBS structure. On the other hand, the manufacturing process of the white light-emitting element is simpler than that of the light-emitting element having an SBS structure, and therefore the manufacturing cost can be reduced or the manufacturing yield can be increased, making it preferable.

[0479] 29A , the light-emitting element has an EL layer 790 between a pair of electrodes (a lower electrode 791 and an upper electrode 792). The EL layer 790 can be composed of a plurality of layers, such as a layer 720, a light-emitting layer 711, and a layer 730. The layer 720 can have, for example, a layer containing a substance with high electron injection properties (electron injection layer) and a layer containing a substance with high electron transport properties (electron transport layer). The light-emitting layer 711 contains, for example, a light-emitting compound. The layer 730 can have, for example, a layer containing a substance with high hole injection properties (hole injection layer) and a layer containing a substance with high hole transport properties (hole transport layer).

[0480] A structure having the layer 720, the light-emitting layer 711, and the layer 730 provided between a pair of electrodes can function as a single light-emitting unit, and the structure of FIG. 29A is referred to as a single structure in this specification.

[0481] 29B shows a modified example of an EL layer 790 included in the light-emitting element shown in Fig. 29A. Specifically, the light-emitting element shown in Fig. 29B includes a layer 730-1 on a lower electrode 791, a layer 730-2 on the layer 730-1, a light-emitting layer 711 on the layer 730-2, a layer 720-1 on the light-emitting layer 711, a layer 720-2 on the layer 720-1, and an upper electrode 792 on the layer 720-2. For example, when the lower electrode 791 is an anode and the upper electrode 792 is a cathode, the layer 730-1 functions as a hole injection layer, the layer 730-2 functions as a hole transport layer, the layer 720-1 functions as an electron transport layer, and the layer 720-2 functions as an electron injection layer. Alternatively, when the lower electrode 791 is used as a cathode and the upper electrode 792 is used as an anode, the layer 730-1 functions as an electron injection layer, the layer 730-2 functions as an electron transport layer, the layer 720-1 functions as a hole transport layer, and the layer 720-2 functions as a hole injection layer. By using such a layer structure, it is possible to efficiently inject carriers into the light-emitting layer 711 and increase the efficiency of carrier recombination in the light-emitting layer 711.

[0482] As shown in FIGS. 29C and 29D, a configuration in which a plurality of light-emitting layers (light-emitting layers 711, 712, and 713) are provided between the layer 720 and the layer 730 is also a variation of the single structure.

[0483] 29E and 29F, a configuration in which a plurality of light-emitting units (EL layer 790a, EL layer 790b) are connected in series via an intermediate layer (charge generating layer) 740 is referred to as a tandem structure in this specification. Note that, although the configuration shown in FIGS. 29E and 29F is referred to as a tandem structure in this specification and the like, this is not limiting, and for example, the tandem structure can also be referred to as a stack structure. Note that by using a tandem structure, a light-emitting element capable of emitting light with high brightness can be obtained.

[0484] In FIG. 29C, the light-emitting layers 711, 712, and 713 may be made of light-emitting materials that emit light of the same color.

[0485] Furthermore, different light-emitting materials may be used for the light-emitting layer 711, the light-emitting layer 712, and the light-emitting layer 713. When the light emitted from the light-emitting layer 711, the light-emitting layer 712, and the light-emitting layer 713 has a complementary color relationship, white light can be obtained. Figure 29D shows an example in which a colored layer 795 that functions as a color filter is provided. When white light passes through the color filter, light of a desired color can be obtained.

[0486] 29E, the same light-emitting material may be used for the light-emitting layer 711 and the light-emitting layer 712. Alternatively, light-emitting materials that emit light of different colors may be used for the light-emitting layer 711 and the light-emitting layer 712. When the light emitted by the light-emitting layer 711 and the light emitted by the light-emitting layer 712 are complementary colors, white light is obtained. FIG. 29F shows an example in which a colored layer 795 is further provided.

[0487] 29C, 29D, 29E, and 29F, the layer 720 and the layer 730 may have a laminated structure consisting of two or more layers, as shown in FIG. 29B.

[0488] 29D, the same light-emitting material may be used for the light-emitting layers 711, 712, and 713. Similarly, in FIG. 29F, the same light-emitting material may be used for the light-emitting layers 711 and 712. In this case, by applying a color conversion layer instead of the colored layer 795, light of a desired color different from the light-emitting material can be obtained. For example, by using a blue light-emitting material for each light-emitting layer and transmitting blue light through the color conversion layer, light with a longer wavelength than blue (e.g., red, green, etc.) can be obtained. For the color conversion layer, a fluorescent material, a phosphorescent material, or quantum dots can be used.

[0489] A structure in which different luminescent colors (here, blue (B), green (G), and red (R)) are produced for each light-emitting element is sometimes called an SBS (Side By Side) structure.

[0490] The light-emitting color of the light-emitting element can be red, green, blue, cyan, magenta, yellow, white, or the like, depending on the material constituting the EL layer 790. Furthermore, the color purity can be further improved by providing the light-emitting element with a microcavity structure.

[0491] A light-emitting element that emits white light preferably has a configuration in which two or more types of light-emitting materials are included in the light-emitting layer. To obtain white light emission, it is preferable to select light-emitting materials such that the emissions of the two light-emitting materials have a complementary color relationship, or to select light-emitting materials such that the emissions of the two or more light-emitting materials combine to produce white light. For example, when white light emission is obtained using two light-emitting layers, a light-emitting element that emits white light as a whole can be obtained by making the emission color of the first light-emitting layer and the emission color of the second light-emitting layer complementary to each other. Furthermore, when white light emission is obtained using three or more light-emitting layers, it is preferable to configure the light-emitting element to emit white light as a whole by combining the emission colors of the three or more light-emitting layers.

[0492] The light-emitting layer preferably contains two or more light-emitting materials that emit light of R (red), G (green), B (blue), Y (yellow), O (orange), etc. Alternatively, it is preferable that the light-emitting layer contains two or more light-emitting materials, and the light emitted by each of the light-emitting materials contains spectral components of two or more colors of R, G, and B.

[0493] 30A shows a schematic cross-sectional view of the light emitting element 750R, the light emitting element 750G, the light emitting element 750B, and the light receiving element 760. The light emitting element 750R, the light emitting element 750G, the light emitting element 750B, and the light receiving element 760 have an upper electrode 792 as a common layer.

[0494] The light-emitting element 750R has a pixel electrode 791R, layers 751 and 752, a light-emitting layer 753R, layers 754 and 755, and an upper electrode 792. The light-emitting element 750G has a pixel electrode 791G and a light-emitting layer 753G. The light-emitting element 750B has a pixel electrode 791B and a light-emitting layer 753B.

[0495] The layer 751 includes, for example, a layer containing a substance with high hole-injection properties (hole-injection layer), the layer 752 includes, for example, a layer containing a substance with high hole-transport properties (hole-transport layer), the layer 754 includes, for example, a layer containing a substance with high electron-transport properties (electron-transport layer), and the layer 755 includes, for example, a layer containing a substance with high electron-injection properties (electron-injection layer).

[0496] Alternatively, a structure in which the layer 751 has an electron-injecting layer, the layer 752 has an electron-transporting layer, the layer 754 has a hole-transporting layer, and the layer 755 has a hole-injecting layer may be used.

[0497] 30A , the layer 751 and the layer 752 are separately illustrated, but the present invention is not limited to this. For example, when the layer 751 has a function of both a hole injection layer and a hole transport layer, or when the layer 751 has a function of both an electron injection layer and an electron transport layer, the layer 752 may be omitted.

[0498] The light-emitting layer 753R of the light-emitting element 750R contains a light-emitting material that emits red light, the light-emitting layer 753G of the light-emitting element 750G contains a light-emitting material that emits green light, and the light-emitting layer 753B of the light-emitting element 750B contains a light-emitting material that emits blue light. The light-emitting elements 750G and 750B have a structure in which the light-emitting layer 753R of the light-emitting element 750R is replaced with the light-emitting layer 753G and the light-emitting layer 753B, respectively, and the other structures are similar to those of the light-emitting element 750R.

[0499] The layers 751, 752, 754, and 755 may have the same structure (material, film thickness, etc.) for the light-emitting elements of each color, or may have different structures.

[0500] The light-receiving element 760 has a pixel electrode 791PD, a layer 761, a layer 762, a layer 763, and an upper electrode 792. The light-receiving element 760 may have a configuration without a hole injection layer and an electron injection layer.

[0501] The layer 762 includes an active layer (also called a photoelectric conversion layer). The layer 762 has a function of absorbing light in a specific wavelength band and generating carriers (electrons and holes).

[0502] The layer 761 and the layer 763 each include, for example, either a hole transport layer or an electron transport layer. When the layer 761 includes a hole transport layer, the layer 763 includes an electron transport layer. On the other hand, when the layer 761 includes an electron transport layer, the layer 763 includes a hole transport layer.

[0503] In addition, the light receiving element 760 may have the pixel electrode 791PD as the anode and the upper electrode 792 as the cathode, or the pixel electrode 791PD as the cathode and the upper electrode 792 as the anode.

[0504] 30B is a modified example of FIG. 30A. In FIG. 30B, the layer 755 is provided in common between the light-emitting elements and between the light-receiving elements, similar to the upper electrode 792. In this case, the layer 755 can be called a common layer. By providing one or more common layers between the light-emitting elements and between the light-receiving elements in this way, the manufacturing process can be simplified, and therefore the manufacturing cost can be reduced.

[0505] Here, layer 755 functions as an electron injection layer or a hole injection layer for light-emitting element 750R etc. At this time, layer 755 functions as an electron transport layer or a hole transport layer for light-receiving element 760. Therefore, layer 763 functioning as an electron transport layer or a hole transport layer does not need to be provided in light-receiving element 760 shown in FIG.

[0506] [Light-Emitting Element] Here, a specific example of the configuration of the light-emitting element will be described.

[0507] The light-emitting element has at least a light-emitting layer. The light-emitting element may further have a layer containing a substance with high hole-injection properties, a substance with high hole-transport properties, a hole-blocking material, a substance with high electron-transport properties, a substance with high electron-injection properties, an electron-blocking material, or a bipolar substance (a substance with high electron-transport properties and high hole-transport properties), as a layer other than the light-emitting layer.

[0508] The light-emitting element can be made of either a low-molecular-weight compound or a high-molecular-weight compound, and may contain an inorganic compound. The layers constituting the light-emitting element can be formed by a method such as vapor deposition (including vacuum vapor deposition), a transfer method, a printing method, an inkjet method, or a coating method.

[0509] For example, the light-emitting element can have one or more layers selected from the group consisting of a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0510] The hole injection layer is a layer that injects holes from the anode into the hole transport layer and contains a material with high hole injection properties, such as an aromatic amine compound and a composite material containing a hole transport material and an acceptor material (electron acceptor material).

[0511] The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light emitting layer. The hole transport layer is a layer that contains a hole transporting material. The hole transporting material is a material having a concentration of 1×10 −６ cm ２ A substance having a hole mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher hole transporting property than electron transporting property. As the hole transporting material, a material having a high hole transporting property, such as a π-electron-rich heteroaromatic compound (e.g., a carbazole derivative, a thiophene derivative, a furan derivative, etc.) or an aromatic amine (a compound having an aromatic amine skeleton), is preferred.

[0512] The electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light emitting layer. The electron transport layer is a layer that contains an electron transporting material. The electron transporting material is a material having a concentration of 1×10 −６ cm ２ A substance having an electron mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher electron transporting property than holes. Examples of electron-transporting materials that can be used include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, and metal complexes having a thiazole skeleton, as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron-deficient heteroaromatic compounds including nitrogen-containing heteroaromatic compounds.

[0513] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer and contains a material with high electron injection properties. Examples of the material with high electron injection properties include alkali metals, alkaline earth metals, and compounds thereof. Examples of the material with high electron injection properties include a composite material containing an electron transport material and a donor material (electron donor material).

[0514] The electron injection layer may be formed of, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ２ ), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatolithium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatolithium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatolithium (abbreviation: LiPPP), lithium oxide (LiO ｘ ), alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. The electron injection layer may have a stacked structure of two or more layers. For example, the stacked structure may have a structure in which lithium fluoride is used in the first layer and ytterbium is provided in the second layer.

[0515] Alternatively, the electron injection layer may be formed using a material having electron transport properties. For example, a compound having an unshared electron pair and an electron-deficient heteroaromatic ring may be used as the material having electron transport properties. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), and a triazine ring may be used.

[0516] The organic compound having an unshared electron pair preferably has a lowest unoccupied molecular orbital (LUMO) level of −3.6 eV to −2.3 eV. Generally, the highest occupied molecular orbital (HOMO) level and the LUMO level of an organic compound can be estimated by cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, inverse photoelectron spectroscopy, or the like.

[0517] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), 2,2′-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), diquinoxalino[2,3-a:2′,3′-c]phenazine (abbreviation: HATNA), 2,4,6-tris[3′-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), etc. can be used as the organic compound having an unshared electron pair. Note that NBPhen has a higher glass transition temperature (Tg) and is superior in heat resistance compared to BPhen.

[0518] The light-emitting layer is a layer containing a light-emitting substance. The light-emitting layer can contain one or more light-emitting substances. As the light-emitting substance, a substance that emits light of a color such as blue, purple, blue-purple, green, yellow-green, yellow, orange, or red is appropriately used. Furthermore, a substance that emits near-infrared light can also be used as the light-emitting substance.

[0519] Examples of the light-emitting material include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0520] Examples of fluorescent materials include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives.

[0521] Examples of phosphorescent materials include organometallic complexes (particularly iridium complexes) having a 4H-triazole skeleton, a 1H-triazole skeleton, an imidazole skeleton, a pyrimidine skeleton, a pyrazine skeleton, or a pyridine skeleton; organometallic complexes (particularly iridium complexes) having a phenylpyridine derivative having an electron-withdrawing group as a ligand; platinum complexes; and rare earth metal complexes.

[0522] The light-emitting layer may contain one or more organic compounds (host materials, assist materials, etc.) in addition to a light-emitting substance (guest material). As the one or more organic compounds, one or both of a hole-transporting material and an electron-transporting material can be used. Furthermore, as the one or more organic compounds, a bipolar material or a TADF material can be used.

[0523] The light-emitting layer preferably includes, for example, a phosphorescent material and a hole-transporting material and an electron-transporting material, which are a combination that easily forms an exciplex. This configuration allows efficient emission using Exciplex-Triple Energy Transfer (ExTET), which is energy transfer from the exciplex to the light-emitting material (phosphorescent material). By selecting a combination that forms an exciplex that emits light that overlaps with the wavelength of the lowest-energy absorption band of the light-emitting material, energy transfer becomes smooth, allowing efficient emission. This configuration simultaneously enables high efficiency, low-voltage operation, and long life of the light-emitting element.

[0524] [Light-receiving element] The active layer of the light-receiving element includes a semiconductor. Examples of the semiconductor include inorganic semiconductors such as silicon and organic semiconductors containing organic compounds. In this embodiment, an example in which an organic semiconductor is used as the semiconductor in the active layer is shown. By using an organic semiconductor, the light-emitting layer and the active layer can be formed by the same method (e.g., vacuum deposition), which is preferable because it allows the use of a common manufacturing device.

[0525] The n-type semiconductor material of the active layer is fullerene (e.g., C ６０ , C ７０Examples of electron-accepting organic semiconductor materials include fullerene derivatives and the like. Fullerenes have a soccer ball-like shape, and this shape is energetically stable. Fullerenes have deep (low) HOMO and LUMO levels. Because fullerenes have a deep LUMO level, they have extremely high electron-accepting (acceptor) properties. Normally, when π-electron conjugation (resonance) spreads on a plane, as in benzene, electron-donating (donor) properties increase, but fullerenes have a spherical shape, so they have high electron-accepting properties despite the wide spread π-electron conjugation. High electron-accepting properties cause charge separation quickly and efficiently, making them useful as light-receiving elements. C ６０ , C ７０ Both have a wide absorption band in the visible light region, and C ７０ is C ６０ In addition, as a fullerene derivative, [6,6]-phenyl-C is preferred because it has a larger π-electron conjugated system and a wide absorption band in the long wavelength region. ７１ -butyric acid methyl ester (abbreviation: PC70BM), [6,6]-Phenyl-C ６１ -butyric acid methyl ester (abbreviation: PC60BM), 1', 1'', 4', 4''-Tetrahydro-di [1, 4] methanonaphthaleno [1, 2: 2', 3', 56, 60: 2'', 3''] [5, 6] fullerene-C ６０ (abbreviation: ICBA) and others.

[0526] Examples of n-type semiconductor materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, naphthalene derivatives, anthracene derivatives, coumarin derivatives, rhodamine derivatives, triazine derivatives, and quinone derivatives.

[0527] Examples of the p-type semiconductor material of the active layer include electron-donating organic semiconductor materials such as copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), and quinacridone.

[0528] Examples of p-type semiconductor materials include carbazole derivatives, thiophene derivatives, furan derivatives, compounds having an aromatic amine skeleton, etc. Examples of p-type semiconductor materials include naphthalene derivatives, anthracene derivatives, pyrene derivatives, triphenylene derivatives, fluorene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, indole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, indolocarbazole derivatives, porphyrin derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, quinacridone derivatives, polyphenylenevinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, polythiophene derivatives, etc.

[0529] The HOMO level of the electron-donating organic semiconductor material is preferably shallower (higher) than the HOMO level of the electron-accepting organic semiconductor material, and the LUMO level of the electron-donating organic semiconductor material is preferably shallower (higher) than the LUMO level of the electron-accepting organic semiconductor material.

[0530] It is preferable to use a spherical fullerene as the electron-accepting organic semiconductor material and a planar organic semiconductor material as the electron-donating organic semiconductor material. Molecules with similar shapes tend to aggregate together, and when molecules of the same type aggregate, the energy levels of their molecular orbitals become close, which can improve carrier transport properties.

[0531] For example, the active layer is preferably formed by co-evaporating an n-type semiconductor and a p-type semiconductor, or may be formed by laminating an n-type semiconductor and a p-type semiconductor.

[0532] The light-receiving element may further include, as a layer other than the active layer, a layer containing a substance with high hole-transporting properties, a substance with high electron-transporting properties, a bipolar substance (a substance with high electron-transporting properties and high hole-transporting properties), etc. Furthermore, without being limited to the above, the light-receiving element may further include a layer containing a substance with high hole-injecting properties, a hole-blocking material, a material with high electron-injecting properties, an electron-blocking material, etc.

[0533] The light-receiving element can be made of either a low-molecular-weight compound or a high-molecular-weight compound, and may contain an inorganic compound. The layers constituting the light-receiving element can be formed by a method such as vapor deposition (including vacuum vapor deposition), transfer, printing, inkjet printing, or coating.

[0534] For example, the hole transport material or electron blocking material may be a polymer compound such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (abbreviated as PEDOT / PSS), or an inorganic compound such as molybdenum oxide or copper iodide (CuI). The electron transport material or hole blocking material may be an inorganic compound such as zinc oxide (ZnO), or an organic compound such as polyethyleneimine ethoxylate (PEIE). The light-receiving element may have, for example, a mixed film of PEIE and ZnO.

[0535] Furthermore, a polymer compound such as poly[[4,8-bis[5-(2-ethylhexyl)-2-thienyl]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl]-2,5-thiophenediyl[5,7-bis(2-ethylhexyl)-4,8-dioxo-4H,8H-benzo[1,2-c:4,5-c']dithiophene-1,3-diyl]]polymer (abbreviation: PBDB-T) or a PBDB-T derivative, which functions as a donor, can be used in the active layer. For example, a method of dispersing an acceptor material in PBDB-T or a PBDB-T derivative can be used.

[0536] The active layer may contain three or more materials. For example, in order to broaden the absorption wavelength range, a third material may be mixed in addition to an n-type semiconductor material and a p-type semiconductor material. In this case, the third material may be either a low molecular weight compound or a high molecular weight compound.

[0537] This concludes the description of the light receiving element.

[0538] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0539] In this embodiment, a structural example of a display device that can be used in an electronic device of one embodiment of the present invention will be described. A display portion of the electronic device of one embodiment of the present invention can include a light-emitting element and a light-receiving element included in the display device.

[0540] One embodiment of the present invention is a display device having a light-emitting element and a light-receiving element. For example, a full-color display device can be realized by including three types of light-emitting elements that respectively emit red (R), green (G), and blue (B) light.

[0541] In one embodiment of the present invention, EL layers and an EL layer and an active layer are processed into fine patterns by photolithography without using a shadow mask such as a metal mask. This makes it possible to realize a display device with high definition and a large aperture ratio, which have been difficult to achieve until now. Furthermore, because the EL layers can be separately formed, a display device with extremely vivid images, high contrast, and high display quality can be realized.

[0542] While it is difficult to achieve a gap of less than 10 μm between different color EL layers or between an EL layer and an active layer using a metal mask, the above method allows the gap to be narrowed to 3 μm or less, 2 μm or less, or even 1 μm or less. For example, by using an exposure device for LSIs, the gap can be narrowed to 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less. This significantly reduces the area of ​​the non-light-emitting region that may exist between two light-emitting elements or between a light-emitting element and a light-receiving element, enabling the aperture ratio to approach 100%. For example, the aperture ratio can be 50% or more, 60% or more, 70% or more, 80% or more, or even 90% or more, and even less than 100%.

[0543] Furthermore, the size of the EL layer and the active layer themselves can be made much smaller than when a metal mask is used. For example, when a metal mask is used to separately form the EL layer, the thickness of the island-shaped EL layer varies between the center and edges, resulting in a smaller effective area that can be used as the light-emitting region relative to the overall area of ​​the EL layer. On the other hand, with the above-described fabrication method, the island-shaped EL layer is formed by processing a film formed to a uniform thickness, making the thickness uniform. Therefore, even if the size of the EL layer is minute, almost the entire area can be used as the light-emitting region. Therefore, the above-described fabrication method can achieve both high definition and a high aperture ratio.

[0544] Organic films formed using FMM (Fine Metal Mask) often have an extremely small taper angle (e.g., greater than 0 degrees and less than 30 degrees), with the thickness decreasing toward the edge. Therefore, organic films formed using FMM have a continuous connection between their side and top surfaces, making it difficult to clearly identify the side surfaces. On the other hand, one embodiment of the present invention has an EL layer processed without using FMM, resulting in clear side surfaces. In particular, one embodiment of the present invention preferably has a portion of the EL layer with a taper angle of 30 degrees or more and 120 degrees or less, preferably 60 degrees or more and 120 degrees or less.

[0545] In this specification, the term "tapered end of an object" refers to a cross-sectional shape in which the angle between the side surface (surface) and the surface to be formed (bottom surface) in the end region is greater than 0 degrees and less than 90 degrees, and the thickness increases continuously from the end. The taper angle refers to the angle between the bottom surface (surface to be formed) and the side surface (surface) at the end of the object.

[0546] A more specific example will be described below.

[0547] Fig. 31A shows a schematic top view of the display device 100. The display device 100 has a plurality of light-emitting elements 90R that exhibit red light, a plurality of light-emitting elements 90G that exhibit green light, a plurality of light-emitting elements 90B that exhibit blue light, and a plurality of light-receiving elements 90S. The display device 100 has a substrate 101, and the light-emitting elements 90R, 90G, 90B, and 90S are each provided on the substrate 101. In Fig. 31A, to easily distinguish between the light-emitting elements, the symbols R, G, B, and S are assigned within the light-emitting regions of each light-emitting element or light-receiving element.

[0548] The light-emitting elements 90R, 90G, 90B, and light-receiving elements 90S are arranged in a matrix. Fig. 31A shows a configuration in which two elements are alternately arranged in one direction. Note that the arrangement method of the light-emitting elements is not limited to this, and arrangement methods such as a stripe arrangement, an S-stripe arrangement, a delta arrangement, a Bayer arrangement, and a zigzag arrangement may also be used, or a pentile arrangement, a diamond arrangement, or the like may also be used.

[0549] 31A also shows a connection electrode 111C that is electrically connected to the common electrode 113. The connection electrode 111C is given a potential (e.g., an anode potential or a cathode potential) to be supplied to the common electrode 113. The connection electrode 111C is provided outside the display area where the light-emitting elements 90R and the like are arranged. Also in FIG. 31A, the common electrode 113 is shown by a dashed line.

[0550] The connection electrode 111C can be provided along the periphery of the display area. For example, it may be provided along one side of the periphery of the display area, or it may be provided over two or more sides of the periphery of the display area. That is, when the top surface of the display area has a rectangular shape, the top surface of the connection electrode 111C can have a strip shape, an L-shape, a U-shape (square bracket shape), a square shape, or the like.

[0551] Fig. 31B is a schematic cross-sectional view corresponding to dashed dotted lines A1-A2 and C1-C2 in Fig. 31A, showing the light-emitting element 90B, the light-emitting element 90R, the light-receiving element 90S, and the connection electrode 111C.

[0552] The light-emitting element 90G, which is not shown in the schematic cross-sectional view, can have the same configuration as the light-emitting element 90B or the light-emitting element 90R, and the following description of these elements can be referred to.

[0553] The light-emitting element 90B has a pixel electrode 111, an organic layer 112B, an organic layer 114, and a common electrode 113. The light-emitting element 90R has a pixel electrode 111, an organic layer 112R, an organic layer 114, and a common electrode 113. The light-receiving element 90S has a pixel electrode 111, an organic layer 115, an organic layer 114, and a common electrode 113. The organic layer 114 and the common electrode 113 are provided in common to the light-emitting element 90B, the light-emitting element 90R, and the light-receiving element 90S. The organic layer 114 can also be referred to as a common layer. The pixel electrodes 111 are provided spaced apart between each light-emitting element and between the light-emitting element and the light-receiving element.

[0554] The organic layer 112R contains a light-emitting organic compound that emits at least red light. The organic layer 112B contains a light-emitting organic compound that emits at least blue light. The organic layer 115 contains a photoelectric conversion material that is sensitive to visible light or infrared light wavelengths. The organic layer 112R and the organic layer 112B can each be referred to as an EL layer.

[0555] The organic layers 112R, 112B, and 115 may each include one or more of an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer. The organic layer 114 may not include a light-emitting layer. For example, the organic layer 114 includes one or more of an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer.

[0556] Here, it is preferable that the uppermost layer in the stacked structure of organic layer 112R, organic layer 112B, and organic layer 115, i.e., the layer in contact with organic layer 114, is a layer other than the light-emitting layer. For example, it is preferable that an electron injection layer, electron transport layer, hole injection layer, hole transport layer, or a layer other than these is provided to cover the light-emitting layer, and that layer is in contact with organic layer 114. In this way, when fabricating each light-emitting element, the reliability of the light-emitting element can be improved by protecting the upper surface of the light-emitting layer with another layer.

[0557] The pixel electrode 111 is provided for each element. The common electrode 113 and the organic layer 114 are provided as a continuous layer common to each light-emitting element. A conductive film that is translucent to visible light is used for either the pixel electrode or the common electrode 113, and a conductive film that is reflective is used for the other. By making each pixel electrode translucent and the common electrode 113 reflective, a bottom-emission display device can be obtained. Conversely, by making each pixel electrode reflective and the common electrode 113 translucent, a top-emission display device can be obtained. Incidentally, by making both the pixel electrodes and the common electrode 113 translucent, a dual-emission display device can also be obtained.

[0558] An insulating layer 131 is provided to cover the end of the pixel electrode 111. The end of the insulating layer 131 is preferably tapered. In this specification and the like, a tapered end of an object means that the angle formed between the surface and the surface on which the object is formed in the end region is greater than 0 degrees and less than 90 degrees, and the object has a cross-sectional shape in which the thickness increases continuously from the end.

[0559] Furthermore, by using an organic resin for the insulating layer 131, the surface can be made gently curved, which improves the coverage of the film formed on the insulating layer 131.

[0560] Examples of materials that can be used for the insulating layer 131 include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins.

[0561] Alternatively, an inorganic insulating material may be used for the insulating layer 131. Examples of inorganic insulating materials that can be used for the insulating layer 131 include oxides or nitrides such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, aluminum oxide, aluminum oxynitride, and hafnium oxide. In addition, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, neodymium oxide, and the like may also be used.

[0562] As shown in Figure 31B, between the light-emitting elements emitting different colors of light and between the light-emitting element and the light-receiving element, two organic layers are spaced apart, with a gap between them. In this way, organic layer 112R, organic layer 112B, and organic layer 115 are preferably arranged so that they do not contact each other. This effectively prevents current from flowing through two adjacent organic layers, which would otherwise cause unintended light emission. This allows for increased contrast and a display device with high display quality.

[0563] The organic layers 112R, 112B, and 115 preferably have a taper angle of 30 degrees or more. The organic layers 112R, 112G, and 112B preferably have an angle between the side surface (surface) and the bottom surface (surface to be formed) at the end of each of the organic layers 112R, 112G, and 112B of 30 degrees or more and 120 degrees or less, preferably 45 degrees or more and 120 degrees or less, and more preferably 60 degrees or more and 120 degrees or less. Alternatively, the organic layers 112R, 112G, and 112B preferably each have a taper angle of 90 degrees or nearly so (for example, 80 degrees or more and 100 degrees or less).

[0564] A protective layer 121 is provided on the common electrode 113. The protective layer 121 has a function of preventing impurities such as water from diffusing from above into each light-emitting element.

[0565] The protective layer 121 may have, for example, a single-layer structure or a multilayer structure including at least an inorganic insulating film. Examples of the inorganic insulating film include oxide films or nitride films such as a silicon oxide film, a silicon oxynitride film, a silicon nitride oxide film, a silicon nitride film, an aluminum oxide film, an aluminum oxynitride film, and a hafnium oxide film. Alternatively, the protective layer 121 may be made of a semiconductor material such as indium gallium oxide or indium gallium zinc oxide.

[0566] Alternatively, the protective layer 121 may be a laminated film of an inorganic insulating film and an organic insulating film. For example, a configuration in which an organic insulating film is sandwiched between a pair of inorganic insulating films is preferable. Furthermore, it is preferable that the organic insulating film functions as a planarizing film. This allows the upper surface of the organic insulating film to be flat, thereby improving the coverage of the inorganic insulating film thereon and enhancing the barrier properties. Furthermore, since the upper surface of the protective layer 121 is flat, it is preferable that when a structure (e.g., a color filter, a touch sensor electrode, a lens array, etc.) is provided above the protective layer 121, the influence of uneven shapes caused by the structure below can be reduced.

[0567] In the connection portion 130, a common electrode 113 is provided in contact with the connection electrode 111C, and a protective layer 121 is provided to cover the common electrode 113. Also, an insulating layer 131 is provided to cover the end of the connection electrode 111C.

[0568] A description will be given below of a structural example of a display device that is partially different from that shown in Fig. 31B. Specifically, an example in which the insulating layer 131 is not provided will be shown.

[0569] 32A to 32D show an example in which the side surface of the pixel electrode 111 and the side surface of the organic layer 112R, the organic layer 112B, or the organic layer 115 are substantially aligned.

[0570] 32A , organic layer 114 is provided to cover the top and side surfaces of organic layer 112R, organic layer 112B, and organic layer 115. Organic layer 114 prevents pixel electrode 111 and common electrode 113 from coming into contact with each other and causing an electrical short circuit.

[0571] 32B shows an example in which an insulating layer 125 is provided in contact with the organic layer 112R, the organic layer 112G, and the organic layer 112B, as well as the side surface of the pixel electrode 111. The insulating layer 125 can effectively prevent an electrical short circuit between the pixel electrode 111 and the common electrode 113 and a leakage current between them.

[0572] The insulating layer 125 can be an insulating layer containing an inorganic material. For example, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film can be used for the insulating layer 125. The insulating layer 125 may have a single-layer structure or a stacked-layer structure. Examples of oxide insulating films include a silicon oxide film, an aluminum oxide film, a magnesium oxide film, an indium gallium zinc oxide film, a gallium oxide film, a germanium oxide film, an yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. Examples of nitride insulating films include a silicon nitride film and an aluminum nitride film. Examples of oxynitride insulating films include a silicon oxynitride film and an aluminum oxynitride film. Examples of nitride oxide insulating films include a silicon nitride oxide film and an aluminum nitride oxide film. In particular, by using an inorganic insulating film such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by an ALD method as the insulating layer 125, an insulating layer 125 with few pinholes and excellent protection of the organic layer can be formed.

[0573] In this specification and elsewhere, an oxynitride refers to a material whose composition contains more oxygen than nitrogen, and a nitride oxide refers to a material whose composition contains more nitrogen than oxygen. For example, silicon oxynitride refers to a material whose composition contains more oxygen than nitrogen, and silicon nitride oxide refers to a material whose composition contains more nitrogen than oxygen.

[0574] The insulating layer 125 can be formed by a sputtering method, a CVD method, a PLD method, an ALD method, or the like. The insulating layer 125 is preferably formed by an ALD method because it has good coverage.

[0575] 32C , a resin layer 126 is provided between two adjacent light-emitting elements or between a light-emitting element and a light-receiving element to fill the gap between two opposing pixel electrodes and the gap between two opposing organic layers. The resin layer 126 can flatten the surfaces on which the organic layer 114, common electrode 113, etc. are formed, thereby preventing the common electrode 113 from being broken due to insufficient coverage of the step between adjacent light-emitting elements.

[0576] An insulating layer containing an organic material can be suitably used as the resin layer 126. For example, the resin layer 126 can be made of acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene-based resin, phenolic resin, or precursors of these resins. Alternatively, the resin layer 126 can be made of organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin. Alternatively, the resin layer 126 can be made of a photosensitive resin. A photoresist can be used as the photosensitive resin. The photosensitive resin can be a positive-type material or a negative-type material.

[0577] Furthermore, by using a colored material (for example, a material containing a black pigment) for the resin layer 126, the layer may be given the function of blocking stray light from adjacent pixels and suppressing color mixing.

[0578] 32D, an insulating layer 125 and a resin layer 126 are provided on the insulating layer 125. The insulating layer 125 prevents the organic layer 112R and the like from coming into contact with the resin layer 126, thereby preventing impurities such as moisture contained in the resin layer 126 from diffusing into the organic layer 112R and the like, thereby making it possible to provide a highly reliable display device.

[0579] In addition, a reflective film (e.g., a metal film containing one or more selected from silver, palladium, copper, titanium, aluminum, etc.) may be provided between the insulating layer 125 and the resin layer 126, and a mechanism for improving the light extraction efficiency may be provided by reflecting the light emitted from the light-emitting layer with the reflective film.

[0580] 33A to 33C show an example in which the width of the pixel electrode 111 is larger than the width of the organic layer 112R, the organic layer 112B, or the organic layer 115. The organic layer 112R and the like are provided inside the end of the pixel electrode 111.

[0581] 33A shows an example in which an insulating layer 125 is provided. The insulating layer 125 is provided to cover the side surfaces of the organic layers of the light-emitting elements or light-receiving elements and part of the upper surface and side surfaces of the pixel electrodes 111.

[0582] 33B shows an example in which a resin layer 126 is provided. The resin layer 126 is located between two adjacent light-emitting elements or between a light-emitting element and a light-receiving element, and is provided so as to cover the side surfaces of the organic layer and the top and side surfaces of the pixel electrode 111.

[0583] 33C shows an example in which both the insulating layer 125 and the resin layer 126 are provided. The insulating layer 125 is provided between the organic layer 112R etc. and the resin layer 126.

[0584] 34A to 34D show examples where the width of pixel electrode 111 is smaller than the width of organic layer 112R, organic layer 112B, or organic layer 115. Organic layer 112R and the like extend outward beyond the edge of pixel electrode 111.

[0585] 34B shows an example having an insulating layer 125. The insulating layer 125 is provided in contact with the side surfaces of the organic layers of two adjacent light-emitting elements. Note that the insulating layer 125 may be provided to cover not only the side surfaces of the organic layer 112R etc. but also part of the upper surface.

[0586] 34C shows an example having a resin layer 126. The resin layer 126 is located between two adjacent light-emitting elements and is provided so as to cover part of the side and upper surfaces of the organic layer 112R, etc. Note that the resin layer 126 may be configured to contact the side surfaces of the organic layer 112R, etc., but not cover the upper surfaces.

[0587] 34D shows an example in which both the insulating layer 125 and the resin layer 126 are provided. The insulating layer 125 is provided between the organic layer 112R etc. and the resin layer 126.

[0588] Here, an example of the structure of the resin layer 126 will be described.

[0589] The upper surface of the resin layer 126 is preferably as flat as possible, but the surface of the resin layer 126 may have a concave or convex shape depending on the uneven shape of the surface on which the resin layer 126 is formed, the conditions under which the resin layer 126 is formed, and the like.

[0590] 35A to 36F show enlarged views of an end portion of a pixel electrode 111R of a light emitting element 90R, an end portion of a pixel electrode 111G of a light emitting element 90G, and their vicinity. An organic layer 112G is provided on the pixel electrode 111G.

[0591] 35A, 35B, and 35C show enlarged views of the resin layer 126 and its vicinity when the upper surface of the resin layer 126 is flat. Fig. 35A shows an example where the width of the organic layer 112R etc. is larger than that of the pixel electrode 111. Fig. 35B shows an example where these widths are approximately the same. Fig. 35C shows an example where the width of the organic layer 112R etc. is smaller than that of the pixel electrode 111.

[0592] 35A , since the organic layer 112R is provided to cover the end of the pixel electrode 111, it is preferable that the end of the pixel electrode 111 has a tapered shape. This improves the step coverage of the organic layer 112R, resulting in a highly reliable display device.

[0593] 35D, 35E, and 35F show examples in which the upper surface of the resin layer 126 is concave. In this case, concave portions that reflect the concave upper surface of the resin layer 126 are formed on the upper surfaces of the organic layer 114, the common electrode 113, and the protective layer 121.

[0594] 36A, 36B, and 36C show an example in which the upper surface of the resin layer 126 is convex. In this case, convex portions that reflect the convex upper surface of the resin layer 126 are formed on the upper surfaces of the organic layer 114, the common electrode 113, and the protective layer 121.

[0595] 36D, 36E, and 36F show examples in which part of resin layer 126 covers the upper end and part of the upper surface of organic layer 112R and the upper end and part of the upper surface of organic layer 112G. In this case, insulating layer 125 is provided between resin layer 126 and the upper surface of organic layer 112R or organic layer 112G.

[0596] 36D, 36E, and 36F show an example in which a part of the upper surface of the resin layer 126 is concave. In this case, the organic layer 114, the common electrode 113, and the protective layer 121 are formed with concave and convex shapes that reflect the shape of the resin layer 126.

[0597] The above is a description of the configuration example of the resin layer.

[0598] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0599] In this embodiment, a display device and a display module that can be used in an electronic device according to one embodiment of the present invention will be described. Although a display device that can display an image will be described here, the display device can also be used as a light-emitting and receiving device by using a light-emitting element as a light source.

[0600] The display device of the present embodiment can be a high-resolution display device or a large-sized display device. Therefore, the display device of the present embodiment can be used in electronic devices having relatively large screens, such as television devices, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, smartphones, wristwatch-type terminals, tablet terminals, personal digital assistants, and sound reproducing devices.

[0601] [Display Device 400] FIG. 37 shows a perspective view of display device 400, and FIG. 38A shows a cross-sectional view of display device 400.

[0602] The display device 400 has a configuration in which a substrate 452 and a substrate 451 are bonded together. In Fig. 37, the substrate 452 is clearly indicated by a dashed line.

[0603] The display device 400 includes a display portion 462, a circuit 464, wiring 465, and the like. FIG. 37 illustrates an example in which an IC 473 and an FPC 472 are mounted on the display device 400. Therefore, the structure illustrated in FIG. 37 can also be referred to as a display module including the display device 400, an IC (integrated circuit), and an FPC. The display portion 462 can include a light-emitting element and a transistor connected to the light-emitting element. The display portion 462 can also include a light-receiving element and a transistor connected to the light-receiving element. The display device 400 can be applied to an electronic device of one embodiment of the present invention, and the circuit 464 and the IC can be included in a control circuit portion of the electronic device of one embodiment of the present invention.

[0604] The circuit 464 can be, for example, a scanning line driver circuit.

[0605] The wiring 465 has a function of supplying signals and power to the display portion 462 and the circuit 464. The signals and power are input to the wiring 465 from the outside via the FPC 472 or input to the wiring 465 from the IC 473.

[0606] 37 shows an example in which an IC 473 is provided on a substrate 451 by a chip-on-glass (COG) method, a chip-on-film (COF) method, or the like. The IC 473 can be, for example, an IC having a scanning line driver circuit or a signal line driver circuit. The display device 400 and the display module may not necessarily include an IC. Alternatively, the IC may be mounted on an FPC by a COF method or the like.

[0607] 38A shows an example of a cross section of the display device 400, which is obtained by cutting a part of a region including the FPC 472, a part of the circuit 464, a part of the display unit 462, and a part of a region including a connection portion. In FIG. 38A, an example of a cross section of the display unit 462 is shown, in particular, by cutting a region including the light-emitting element 430b that emits green light (G) and the light-receiving element 440 that receives reflected light (L).

[0608] A display device 400 shown in FIG. 38A includes a transistor 252, a transistor 260, a transistor 258, a light-emitting element 430b, a light-receiving element 440, and the like between a substrate 453 and a substrate 454.

[0609] The light-emitting element 430b and the light-receiving element 440 can be any of the light-emitting elements or light-receiving elements exemplified above.

[0610] Here, when a pixel of a display device has three types of subpixels having light-emitting elements of different light colors, the three subpixels may be subpixels of three colors: red (R), green (G), and blue (B), or subpixels of three colors: yellow (Y), cyan (C), and magenta (M). When a pixel of a display device has four subpixels, the four subpixels may be subpixels of four colors: R, G, B, and white (W), or subpixels of four colors: R, G, B, and Y. Alternatively, the subpixels may be equipped with light-emitting elements that emit infrared light.

[0611] Furthermore, as the light receiving element 440, a photoelectric conversion element having sensitivity to light in the red, green, or blue wavelength region, or a photoelectric conversion element having sensitivity to light in the infrared wavelength region can be used.

[0612] The substrate 454 and the protective layer 416 are bonded together via an adhesive layer 442. The adhesive layer 442 is provided to overlap the light-emitting element 430b and the light-receiving element 440, respectively, and a solid sealing structure is applied to the display device 400. A light-shielding layer 417 is provided on the substrate 454.

[0613] The light-emitting element 430b and the light-receiving element 440 each have a conductive layer 411a, a conductive layer 411b, and a conductive layer 411c as pixel electrodes. The conductive layer 411b is reflective to visible light and functions as a reflective electrode. The conductive layer 411c is transparent to visible light and functions as an optical adjustment layer.

[0614] A conductive layer 411a included in the light-emitting element 430b is connected to a conductive layer 272b included in the transistor 260 through an opening provided in the insulating layer 264. The transistor 260 has a function of controlling driving of the light-emitting element. On the other hand, the conductive layer 411a included in the light-receiving element 440 is electrically connected to a conductive layer 272b included in the transistor 258. The transistor 258 has a function of controlling the timing of exposure using the light-receiving element 440, etc.

[0615] An EL layer 412G or a photoelectric conversion layer 412S is provided to cover the pixel electrode. An insulating layer 491 is provided in contact with the side surfaces of the EL layer 412G and the photoelectric conversion layer 412S, and a resin layer 492 is provided to fill the recesses in the insulating layer 491. An organic layer 414, a common electrode 413, and a protective layer 416 are provided to cover the EL layer 412G and the photoelectric conversion layer 412S. Providing the protective layer 416 to cover the light-emitting element can prevent impurities such as water from entering the light-emitting element, thereby improving the reliability of the light-emitting element.

[0616] Light G emitted by the light-emitting element 430b is emitted toward the substrate 452. The light-receiving element 440 receives light L incident through the substrate 452 and converts it into an electrical signal. The substrate 452 is preferably made of a material that is highly transparent to visible light.

[0617] The transistor 252, the transistor 260, and the transistor 258 are all formed over a substrate 451. These transistors can be manufactured using the same material and through the same process.

[0618] Note that the transistor 252, the transistor 260, and the transistor 258 may be fabricated to have different structures. For example, transistors may be fabricated with or without a back gate, or transistors may be fabricated with different materials and / or thicknesses of semiconductors, gate electrodes, gate insulating layers, source electrodes, and drain electrodes.

[0619] When a flexible material is used for the substrate 453, the flexibility of the display device can be increased.

[0620] To provide the display device 400 with flexibility, a manufacturing substrate on which the insulating layer 262, the transistors, the light-emitting elements, the light-receiving elements, and the like are provided is first bonded to a substrate 454 on which the light-shielding layer 417 is provided, using an adhesive layer. Then, the manufacturing substrate is peeled off, and a substrate 453 is attached to the exposed surface, whereby each component formed on the manufacturing substrate is transferred to the substrate 453. This can increase the flexibility of the display device 400.

[0621] A connection portion 254 is provided in a region of the substrate 453 where the substrate 454 does not overlap. In the connection portion 254, the wiring 465 is electrically connected to the FPC 472 via a conductive layer 466 and a connection layer 292. The conductive layer 466 can be obtained by processing the same conductive film as the pixel electrode. This allows the connection portion 254 and the FPC 472 to be electrically connected via the connection layer 292.

[0622] The transistor 252, the transistor 260, and the transistor 258 each include a conductive layer 271 functioning as a gate, an insulating layer 261 functioning as a gate insulating layer, a semiconductor layer 281 including a channel formation region 281i and a pair of low-resistance regions 281n, a conductive layer 272a connected to one of the pair of low-resistance regions 281n, a conductive layer 272b connected to the other of the pair of low-resistance regions 281n, an insulating layer 275 functioning as a gate insulating layer, a conductive layer 273 functioning as a gate, and an insulating layer 265 covering the conductive layer 273. The insulating layer 261 is located between the conductive layer 271 and the channel formation region 281i. The insulating layer 275 is located between the conductive layer 273 and the channel formation region 281i.

[0623] The conductive layer 272a and the conductive layer 272b are each connected to the low-resistance region 281n through an opening provided in the insulating layer 265. One of the conductive layer 272a and the conductive layer 272b functions as a source, and the other functions as a drain.

[0624] 38A shows an example in which the top surface and side surfaces of the semiconductor layer are covered with an insulating layer 275. The conductive layer 272a and the conductive layer 272b are connected to the low-resistance region 281n through openings provided in the insulating layer 275 and the insulating layer 265, respectively.

[0625] 38B , the insulating layer 275 overlaps with the channel formation region 281i of the semiconductor layer 281 but does not overlap with the low-resistance region 281n. For example, the structure shown in FIG. 38B can be manufactured by processing the insulating layer 275 using the conductive layer 273 as a mask. In FIG. 38B , an insulating layer 265 is provided to cover the insulating layer 275 and the conductive layer 273, and the conductive layer 272a and the conductive layer 272b are connected to the low-resistance region 281n through openings in the insulating layer 265. Furthermore, an insulating layer 268 may be provided to cover the transistor.

[0626] The structure of the transistor included in the display device of this embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, an inverted staggered transistor, or the like can be used. Furthermore, either a top-gate transistor or a bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below a semiconductor layer in which a channel is formed.

[0627] The transistors 252, 260, and 258 each have a structure in which a semiconductor layer in which a channel is formed is sandwiched between two gates. The two gates may be connected and the same signal may be supplied to drive the transistor. Alternatively, the threshold voltage of the transistor may be controlled by applying a potential for controlling the threshold voltage to one of the two gates and a potential for driving the other.

[0628] The crystallinity of a semiconductor material used for a semiconductor layer of a transistor is not particularly limited, and any of an amorphous semiconductor, a single-crystal semiconductor, and a semiconductor having crystallinity other than single crystal (a microcrystalline semiconductor, a polycrystalline semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a single-crystal semiconductor or a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0629] The semiconductor layer of the transistor preferably includes a metal oxide (also referred to as an oxide semiconductor). That is, the display device of this embodiment preferably includes a transistor using a metal oxide for a channel formation region (hereinafter referred to as an OS transistor).

[0630] The band gap of the metal oxide used for the semiconductor layer of the transistor is preferably 2 eV or more, more preferably 2.5 eV or more. Use of a metal oxide with a wide band gap can reduce the off-state current of the OS transistor.

[0631] The metal oxide preferably contains at least indium or zinc, and more preferably contains indium and zinc. For example, the metal oxide preferably contains indium, M (wherein M is one or more selected from gallium, aluminum, yttrium, tin, silicon, boron, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, and cobalt), and zinc. In particular, M is preferably one or more selected from gallium, aluminum, yttrium, and tin, and more preferably gallium. Note that a metal oxide containing indium, M, and zinc may be referred to as an In-M-Zn oxide hereinafter.

[0632] When the metal oxide is an In-M-Zn oxide, the atomic ratio of In in the In-M-Zn oxide is preferably equal to or greater than the atomic ratio of M. Examples of atomic ratios of metal elements in such In-M-Zn oxides include a composition in which In:M:Zn=1:1:1 or thereabouts, a composition in which In:M:Zn=1:1:1.2 or thereabouts, a composition in which In:M:Zn=2:1:3 or thereabouts, a composition in which In:M:Zn=3:1:2 or thereabouts, a composition in which In:M:Zn=4:2:3 or thereabouts, a composition in which In:M:Zn=4:2:4.1 or thereabouts, a composition in which In:M:Zn=5:1:3 or thereabouts, a composition in which In:M:Zn=5:1:6 or thereabouts, a composition in which In:M:Zn=5:1:7 or thereabouts, a composition in which In:M:Zn=5:1:8 or thereabouts, a composition in which In:M:Zn=6:1:6 or thereabouts, and a composition in which In:M:Zn=5:2:5 or thereabouts. Note that the term "nearby composition" includes a range of ±30% of the desired atomic ratio. By increasing the atomic ratio of indium in the metal oxide, the on-state current, field-effect mobility, and the like of the transistor can be increased.

[0633] For example, when describing a composition having an atomic ratio of In:Ga:Zn=4:2:3 or thereabout, this includes a case where, when In is taken as 4, Ga is 1 or more and 3 or less, and Zn is 2 or more and 4 or less. Furthermore, when describing a composition having an atomic ratio of In:Ga:Zn=5:1:6 or thereabout, this includes a case where, when In is taken as 5, Ga is more than 0.1 and 2 or less, and Zn is 5 or more and 7 or less. Furthermore, when describing a composition having an atomic ratio of In:Ga:Zn=1:1:1 or thereabout, this includes a case where, when In is taken as 1, Ga is more than 0.1 and 2 or less, and Zn is more than 0.1 and 2 or less.

[0634] Furthermore, the atomic ratio of In in the In-M-Zn oxide may be less than the atomic ratio of M. Examples of atomic ratios of metal elements in such an In-M-Zn oxide include a composition of In:M:Zn=1:3:2 or thereabouts, a composition of In:M:Zn=1:3:3 or thereabouts, and a composition of In:M:Zn=1:3:4 or thereabouts. Increasing the atomic ratio of M in the metal oxide can increase the band gap of the In-M-Zn oxide and improve its resistance to a negative bias stress test due to light irradiation. Specifically, the amount of change in threshold voltage or the amount of change in shift voltage (Vsh) measured in a negative bias temperature illumination stress (NBTIS) test of a transistor can be reduced. The shift voltage (Vsh) is defined as the Vg at which the tangent to the maximum slope of the drain current (Id)-gate voltage (Vg) curve of the transistor intersects with the line of Id=1 pA.

[0635] Alternatively, the semiconductor layer of the transistor may contain silicon, such as amorphous silicon or crystalline silicon (such as low-temperature polysilicon or single-crystal silicon).

[0636] In particular, low-temperature polysilicon has a relatively high mobility and can be formed over a glass substrate, and therefore can be suitably used in display devices. For example, a transistor using low-temperature polysilicon for a semiconductor layer can be applied to the transistor 252 in the driver circuit, and a transistor using an oxide semiconductor for a semiconductor layer can be applied to the transistor 260 and the transistor 258 provided in the pixel.

[0637] Alternatively, the semiconductor layer of the transistor may include a layered material that functions as a semiconductor. A layered material is a general term for a group of materials having a layered crystal structure. A layered crystal structure is a structure in which layers formed by covalent or ionic bonds are stacked via bonds weaker than covalent or ionic bonds, such as van der Waals bonds. A layered material has high electrical conductivity within a unit layer, that is, high two-dimensional electrical conductivity. By using a material that functions as a semiconductor and has high two-dimensional electrical conductivity in the channel formation region, a transistor with a large on-state current can be provided.

[0638] Examples of the layered material include graphene, silicene, and chalcogenides. Chalcogenides are compounds containing chalcogen (an element belonging to Group 16). Examples of chalcogenides include transition metal chalcogenides and Group 13 chalcogenides. Specific examples of transition metal chalcogenides that can be used as semiconductor layers of transistors include molybdenum sulfide (typically MoS ２ ), molybdenum selenide (typically MoSe ２ ), molybdenum telluride (typically MoTe ２ ), tungsten sulfide (typically WS ２ ), tungsten selenide (typically WSe ２ ), tungsten tellurium (typically WTe ２ ), hafnium sulfide (typically HfS ２ ), hafnium selenide (typically HfSe ２ ), zirconium sulfide (typically ZrS ２ ), zirconium selenide (typically ZrSe ２ ) etc.

[0639] The transistors included in the circuit 464 may have the same structure as or different from the transistors included in the display portion 462. The transistors included in the circuit 464 may all have the same structure or may have two or more types of structures. Similarly, the transistors included in the display portion 462 may all have the same structure or may have two or more types of structures.

[0640] At least one insulating layer covering the transistor is preferably made of a material that is resistant to the diffusion of impurities such as water and hydrogen. This allows the insulating layer to function as a barrier layer. With this structure, it is possible to effectively prevent impurities from diffusing into the transistor from the outside, thereby improving the reliability of the display device.

[0641] It is preferable to use an inorganic insulating film for each of the insulating layers 261, 262, 265, 268, and 275. Examples of the inorganic insulating film that can be used include a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, and an aluminum nitride film. Alternatively, a hafnium oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, and a neodymium oxide film may also be used. Two or more of the above-described inorganic insulating films may be stacked.

[0642] Here, organic insulating films often have lower barrier properties than inorganic insulating films. Therefore, it is preferable that the organic insulating film has an opening near the edge of the display device 400. This makes it possible to prevent impurities from entering from the edge of the display device 400 through the organic insulating film. Alternatively, the organic insulating film may be formed so that the edge of the organic insulating film is located inside the edge of the display device 400, so that the organic insulating film is not exposed at the edge of the display device 400.

[0643] An organic insulating film is suitable for the insulating layer 264 that functions as a planarizing layer. Materials that can be used for the organic insulating film include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins.

[0644] It is preferable to provide a light-shielding layer 417 on the surface of substrate 454 facing substrate 453. Various optical members can be arranged on the outside of substrate 454. Examples of optical members include a polarizing plate, a retardation plate, a light diffusion layer (such as a diffusion film), an anti-reflection layer, and a light-collecting film. The outside of substrate 454 may also be arranged with an antistatic film that suppresses the adhesion of dust, a water-repellent film that makes it difficult for dirt to adhere, a hard coat film that suppresses the occurrence of scratches during use, an impact absorbing layer, or the like.

[0645] Fig. 38A shows a connection portion 278. The common electrode 413 and a wiring are electrically connected at the connection portion 278. Fig. 38A shows an example in which the same layered structure as that of the pixel electrode is applied to the wiring.

[0646] The substrate 453 and the substrate 454 can each be made of glass, quartz, ceramics, sapphire, resin, metal, alloy, semiconductor, or the like. Alternatively, a semiconductor substrate such as a single crystal semiconductor substrate made of silicon, silicon carbide, or the like, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or an SOI substrate can be used. A substrate provided with a circuit including a transistor may also be used as the substrate 453. A light-transmitting material is used for the substrate on the side from which light from a light-emitting element is extracted. The use of a flexible material for the substrate 453 and the substrate 454 can increase the flexibility of the display device. Alternatively, a polarizing plate may be used for the substrate 453 or the substrate 454.

[0647] When substrate 453 and substrate 454 are made of a flexible material, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamideimide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. One or both of substrates 453 and 454 may be made of glass having a thickness sufficient to provide flexibility.

[0648] When a circularly polarizing plate is superimposed on a display device, it is preferable that the display device has a substrate with high optical isotropy. A substrate with high optical isotropy has small birefringence (or a small amount of birefringence).

[0649] The absolute value of the retardation (phase difference) of a substrate having high optical isotropy is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0650] Examples of films with high optical isotropy include triacetyl cellulose (TAC, also known as cellulose triacetate) films, cycloolefin polymer (COP) films, cycloolefin copolymer (COC) films, and acrylic films.

[0651] Furthermore, when a film is used as a substrate, the film may absorb water, causing deformation such as wrinkles in the display panel. Therefore, it is preferable to use a film with low water absorption for the substrate. For example, it is preferable to use a film with a water absorption rate of 1% or less, more preferably 0.1% or less, and even more preferably 0.01% or less.

[0652] The adhesive layer can be made of various curable adhesives, such as photo-curable adhesives (e.g., ultraviolet curable), reactive curable adhesives, thermosetting adhesives, and anaerobic adhesives. Examples of such adhesives include epoxy resin, acrylic resin, silicone resin, phenolic resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin, and EVA (ethylene vinyl acetate) resin. Materials with low moisture permeability, such as epoxy resin, are particularly preferred. Two-component resins may also be used. Adhesive sheets, etc., may also be used.

[0653] The connection layer 292 may be made of an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0654] Materials that can be used for conductive layers such as the gate, source, and drain of a transistor, as well as various wirings and electrodes that constitute a display device include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, and alloys containing these metals as main components, etc. Films containing these materials can be used as a single layer or a stacked layer structure.

[0655] Examples of light-transmitting conductive materials include conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing such metal materials, can be used. Alternatively, nitrides of such metal materials (e.g., titanium nitride) can be used. When using metal materials or alloy materials (or their nitrides), it is preferable to thin them sufficiently to ensure light-transmitting properties. A stacked film of the above materials can also be used as the conductive layer. For example, a stacked film of an alloy of silver and magnesium and indium tin oxide is preferable because it can enhance conductivity. These materials can also be used for conductive layers such as various wirings and electrodes constituting a display device, and for conductive layers (conductive layers functioning as pixel electrodes or common electrodes) of light-emitting elements.

[0656] Examples of insulating materials that can be used for each insulating layer include resins such as acrylic resin and epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide.

[0657] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be combined as appropriate with other configuration examples or drawings.

[0658] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0659] Embodiment 8 In this embodiment, a metal oxide (also referred to as an oxide semiconductor) that can be used for the OS transistor described in the above embodiment will be described.

[0660] The metal oxide used in the OS transistor preferably contains at least indium or zinc, and more preferably contains indium and zinc. For example, the metal oxide preferably contains indium, M (M is one or more selected from gallium, aluminum, yttrium, tin, silicon, boron, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, and cobalt), and zinc. In particular, M is preferably one or more selected from gallium, aluminum, yttrium, and tin, and more preferably gallium.

[0661] The metal oxide can be formed by a sputtering method, a chemical vapor deposition (CVD) method such as a metal organic chemical vapor deposition (MOCVD) method, or an atomic layer deposition (ALD) method.

[0662] Hereinafter, an oxide containing indium (In), gallium (Ga), and zinc (Zn) will be described as an example of a metal oxide. Note that an oxide containing indium (In), gallium (Ga), and zinc (Zn) may be referred to as an In—Ga—Zn oxide.

[0663] <Classification of Crystal Structure> Examples of the crystal structure of an oxide semiconductor include amorphous (including completely amorphous), c-axis-aligned crystalline line (CAAC), nanocrystalline line (nc), cloud-aligned composite (CAC), single crystal, and polycrystalline.

[0664] The crystalline structure of a film or substrate can be evaluated using an X-ray diffraction (XRD) spectrum. For example, it can be evaluated using an XRD spectrum obtained by GIXD (Grazing-Incident XRD) measurement. The GIXD method is also called the thin film method or the Seemann-Bohlin method. In the following, the XRD spectrum obtained by GIXD measurement may be simply referred to as the XRD spectrum.

[0665] For example, in the case of a quartz glass substrate, the peak shape of the XRD spectrum is almost symmetrical. On the other hand, in the case of an In-Ga-Zn oxide film having a crystalline structure, the peak shape of the XRD spectrum is asymmetrical. The asymmetrical peak shape of the XRD spectrum clearly indicates the presence of crystals in the film or substrate. In other words, if the peak shape of the XRD spectrum is not symmetrical, the film or substrate cannot be said to be in an amorphous state.

[0666] The crystalline structure of a film or substrate can be evaluated by a diffraction pattern (also called a nanobeam electron diffraction pattern) observed by nanobeam electron diffraction (NBED). For example, a halo is observed in the diffraction pattern of a quartz glass substrate, confirming that the quartz glass is in an amorphous state. Furthermore, a spot-like pattern is observed in the diffraction pattern of an In—Ga—Zn oxide film formed at room temperature, rather than a halo. For this reason, it is estimated that the In—Ga—Zn oxide formed at room temperature is neither single crystal nor polycrystalline, nor in an amorphous state, but is in an intermediate state, and it cannot be concluded that it is in an amorphous state.

[0667] <<Structure of Oxide Semiconductor>> Note that oxide semiconductors may be classified differently from the above when focusing on their structures. For example, oxide semiconductors are classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include the above-mentioned CAAC-OS and nc-OS. Non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, pseudo-amorphous-like oxide semiconductors (a-like OSs), amorphous oxide semiconductors, and the like.

[0668] Here, the above-mentioned CAAC-OS, nc-OS, and a-like OS will be described in detail.

[0669] [CAAC-OS] A CAAC-OS is an oxide semiconductor having multiple crystalline regions, each with its c-axis aligned in a specific direction. The specific direction refers to the thickness direction of the CAAC-OS film, the normal direction to the surface where the CAAC-OS film is formed, or the normal direction to the surface of the CAAC-OS film. A crystalline region is a region having periodic atomic arrangement. If the atomic arrangement is considered as a lattice arrangement, a crystalline region is also a region with a uniform lattice arrangement. Furthermore, a CAAC-OS has a region where multiple crystalline regions are connected in the a-b plane direction, and the region may have distortion. Note that distortion refers to a portion where the lattice arrangement changes between a region with a uniform lattice arrangement and a region with another uniform lattice arrangement in a region where multiple crystalline regions are connected. In other words, a CAAC-OS is an oxide semiconductor whose c-axes are aligned and whose orientation is not clearly aligned in the a-b plane direction.

[0670] Each of the multiple crystalline regions is composed of one or more minute crystals (crystals with a maximum diameter of less than 10 nm). When a crystalline region is composed of a single minute crystal, the maximum diameter of the crystalline region is less than 10 nm. When a crystalline region is composed of many minute crystals, the size of the crystalline region may be several tens of nanometers.

[0671] In an In—Ga—Zn oxide, CAAC-OS tends to have a layered crystal structure (also referred to as a layered structure) in which a layer containing indium (In) and oxygen (hereinafter referred to as an In layer) and a layer containing gallium (Ga), zinc (Zn), and oxygen (hereinafter referred to as a (Ga, Zn) layer) are stacked. Note that indium and gallium are mutually substituted. Therefore, the (Ga, Zn) layer may contain indium. The In layer may contain gallium. The In layer may contain zinc. The layered structure is observed as a lattice image in a high-resolution transmission electron microscope (TEM) image, for example.

[0672] When a CAAC-OS film is subjected to structural analysis using an XRD apparatus, for example, a peak indicating c-axis orientation is detected at or near 2θ = 31° in out-of-plane XRD measurement using θ / 2θ scanning. Note that the position of the peak indicating c-axis orientation (the value of 2θ) may vary depending on the type and composition of the metal elements constituting the CAAC-OS.

[0673] For example, multiple bright spots are observed in the electron diffraction pattern of a CAAC-OS film, and the spots are observed at positions that are point-symmetric with respect to a spot of an incident electron beam that has passed through the sample (also referred to as a direct spot).

[0674] When a crystalline region is observed from the specific direction, the lattice arrangement in the crystalline region is basically a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be a non-regular hexagon. The distortion may have a pentagonal, heptagonal, or other lattice arrangement. In CAAC-OS, no clear grain boundary can be identified even near the distortion. This indicates that the distortion in the lattice arrangement suppresses the formation of grain boundaries. This is thought to be because CAAC-OS can tolerate distortion due to the lack of close-packed oxygen atom arrangement in the a-b plane direction and the change in interatomic bond distance caused by metal atom substitution.

[0675] Note that a crystal structure in which clear grain boundaries are observed is called polycrystalline. The grain boundaries act as recombination centers, and are likely to trap carriers, resulting in a decrease in the on-state current of a transistor and a decrease in field-effect mobility. Therefore, CAAC-OS, in which clear grain boundaries are not observed, is one of the crystalline oxides having a crystal structure suitable for a semiconductor layer of a transistor. Note that a structure containing Zn is preferable for forming a CAAC-OS. For example, In—Zn oxide and In—Ga—Zn oxide are suitable because they can suppress the generation of grain boundaries more effectively than In oxide.

[0676] CAAC-OS is an oxide semiconductor with high crystallinity and no clear crystal grain boundaries. Therefore, it can be said that the CAAC-OS is less susceptible to a decrease in electron mobility due to crystal grain boundaries. Furthermore, since the crystallinity of an oxide semiconductor can be reduced by the inclusion of impurities, the formation of defects, or the like, the CAAC-OS can also be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Therefore, an oxide semiconductor having a CAAC-OS has stable physical properties. Therefore, an oxide semiconductor having a CAAC-OS is heat-resistant and highly reliable. Furthermore, the CAAC-OS is stable even against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, the use of a CAAC-OS in an OS transistor can increase the flexibility of the manufacturing process.

[0677] [nc-OS] The nc-OS has periodic atomic arrangement in a microscopic region (e.g., a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm). In other words, the nc-OS has microcrystals. Note that the size of the microcrystals is, for example, 1 nm to 10 nm, particularly 1 nm to 3 nm, and therefore the microcrystals are also called nanocrystals. Furthermore, the nc-OS does not exhibit regularity in the crystal orientation between different nanocrystals. Therefore, no orientation is observed throughout the film. Therefore, depending on the analysis method, the nc-OS may be indistinguishable from an a-like OS or an amorphous oxide semiconductor. For example, when a structural analysis of an nc-OS film is performed using an XRD apparatus, no peak indicating crystallinity is detected in out-of-plane XRD measurement using θ / 2θ scanning. When an nc-OS film is subjected to electron diffraction (also referred to as selected-area electron diffraction) using an electron beam with a probe diameter larger than that of a nanocrystal (e.g., 50 nm or more), a diffraction pattern resembling a halo pattern is observed. On the other hand, when an nc-OS film is subjected to electron diffraction (also referred to as nanobeam electron diffraction) using an electron beam with a probe diameter close to or smaller than that of a nanocrystal (e.g., 1 nm to 30 nm), an electron diffraction pattern in which multiple spots are observed within a ring-shaped region centered on a direct spot may be obtained.

[0678] [a-Like OS] The a-like OS is an oxide semiconductor having a structure between the nc-OS and the amorphous oxide semiconductor. The a-like OS has a pore or low-density region. That is, the a-like OS has lower crystallinity than the nc-OS and the CAAC-OS. Furthermore, the a-like OS has a higher hydrogen concentration in the film than the nc-OS and the CAAC-OS.

[0679] <<Structure of Oxide Semiconductor>> Next, the above-described CAC-OS will be described in detail. Note that the CAC-OS relates to a material structure.

[0680] [CAC-OS] CAC-OS is, for example, a material in which elements constituting a metal oxide are unevenly distributed in a size of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof. Note that hereinafter, a state in which one or more metal elements are unevenly distributed in a metal oxide and regions containing the metal elements are mixed in a size of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof, is also referred to as a mosaic or patch state.

[0681] Furthermore, the CAC-OS has a mosaic structure in which a material is separated into a first region and a second region, and the first region is distributed throughout the film (hereinafter also referred to as a cloud structure). That is, the CAC-OS is a composite metal oxide having a structure in which the first region and the second region are mixed.

[0682] Here, the atomic ratios of In, Ga, and Zn to the metal elements constituting the CAC-OS in the In—Ga—Zn oxide are denoted as [In], [Ga], and [Zn], respectively. For example, in the CAC-OS in the In—Ga—Zn oxide, the first region is a region where [In] is larger than [In] in the composition of the CAC-OS film. The second region is a region where [Ga] is larger than [Ga] in the composition of the CAC-OS film. Alternatively, for example, the first region is a region where [In] is larger than [In] in the second region and [Ga] is smaller than [Ga] in the second region. The second region is a region where [Ga] is larger than [Ga] in the first region and [In] is smaller than [In] in the first region.

[0683] Specifically, the first region is a region whose main component is indium oxide, indium zinc oxide, or the like. The second region is a region whose main component is gallium oxide, gallium zinc oxide, or the like. In other words, the first region can be referred to as a region whose main component is In. The second region can be referred to as a region whose main component is Ga.

[0684] It should be noted that there are cases where a clear boundary between the first region and the second region cannot be observed.

[0685] Furthermore, CAC-OS in In—Ga—Zn oxide refers to a structure in which a mosaic of regions containing Ga as the main component and regions containing In as the main component are randomly arranged in a material composition containing In, Ga, Zn, and O. Therefore, it is presumed that CAC-OS has a structure in which metal elements are distributed nonuniformly.

[0686] The CAC-OS can be formed by sputtering without heating the substrate, for example. When forming the CAC-OS by sputtering, any one or more of an inert gas (typically argon), oxygen gas, and nitrogen gas may be used as the deposition gas. The lower the flow rate of oxygen gas relative to the total flow rate of deposition gas during deposition, the more preferable it is. For example, the flow rate of oxygen gas relative to the total flow rate of deposition gas during deposition is set to 0% or more and less than 30%, preferably 0% or more and 10% or less.

[0687] Furthermore, for example, in the case of CAC-OS in an In—Ga—Zn oxide, EDX mapping obtained using energy dispersive X-ray spectroscopy (EDX) can confirm that the CAC-OS has a structure in which a region containing In as a main component (first region) and a region containing Ga as a main component (second region) are unevenly distributed and mixed.

[0688] Here, the first region has higher conductivity than the second region. That is, the flow of carriers through the first region causes the metal oxide to exhibit conductivity. Therefore, the first region is distributed in a cloud-like manner in the metal oxide, thereby achieving a high field-effect mobility (μ).

[0689] On the other hand, the second region has higher insulating properties than the first region. That is, the second region is distributed in the metal oxide, thereby suppressing leakage current.

[0690] Therefore, when a CAC-OS is used in a transistor, the conductivity due to the first region and the insulating property due to the second region act complementarily, thereby providing the CAC-OS with a switching function (a function of turning on / off). In other words, a CAC-OS has a conductive function in a part of the material and an insulating function in a part of the material, and the entire material functions as a semiconductor. By separating the conductive function and the insulating function, both functions can be maximized. Therefore, by using a CAC-OS in a transistor, a high on-current (I ｏｎ ), high field-effect mobility (μ), and good switching behavior can be achieved.

[0691] Furthermore, a transistor using the CAC-OS has high reliability, which can improve the reliability of electronic devices to which the CAC-OS is applied.

[0692] Oxide semiconductors have a variety of structures, each of which has different characteristics. The oxide semiconductor of one embodiment of the present invention may include two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, an a-like OS, a CAC-OS, an nc-OS, and a CAAC-OS.

[0693] <Transistor Having Oxide Semiconductor> Next, a case where the oxide semiconductor is used for a transistor will be described.

[0694] By using the oxide semiconductor for a transistor, a transistor with high field-effect mobility and high reliability can be realized.

[0695] For the transistor, an oxide semiconductor having a low carrier concentration is preferably used. For example, the carrier concentration of the oxide semiconductor is 1×10 １７ cm −３ Below 1 × 10, preferably １５ cm −３ More preferably, 1×10 １３ cm −３ or less, more preferably 1 × 10 １１ cm −３ More preferably, 1×10 １０ cm−３ is less than 1×10 −９ cm −３ That is all. Note that when the carrier concentration of an oxide semiconductor film is reduced, the carrier concentration can be reduced by reducing the impurity concentration in the oxide semiconductor film and reducing the density of defect states. In this specification and the like, a semiconductor having a low impurity concentration and a low density of defect states is referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor. Note that an oxide semiconductor having a low carrier concentration may be referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor.

[0696] Furthermore, a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor film has a low density of defect states, and therefore the density of trap states may also be low.

[0697] Furthermore, charges trapped in the trap states of an oxide semiconductor take a long time to disappear and may behave like fixed charges. Therefore, a transistor in which a channel formation region is formed in an oxide semiconductor with a high density of trap states may have unstable electrical characteristics.

[0698] Therefore, reducing the impurity concentration in the oxide semiconductor is effective for stabilizing the electrical characteristics of a transistor. Furthermore, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in adjacent films. Exampl...

Claims

having a display unit, the display unit having a plurality of light-emitting elements and a plurality of light-receiving elements, the light-receiving elements receiving reflected light of light emitted from the light-emitting elements from a subject, the light-receiving elements receiving light during a first detection period, during the first detection period, the light-emitting elements emitting light at a first luminance, the light-receiving elements receiving light during a second detection period shorter than the first detection period, during the second detection period, the light-emitting elements emitting light at a second luminance higher than the first luminance, an electronic device. 　 In claim 1, the light-receiving elements receiving light during the first detection period when the illuminance of external light is equal to or less than a first value, and receiving light during the second detection period when the illuminance of the external light is higher than the first value, an electronic device. 　 having a display unit, the display unit having a plurality of pixel circuits and a plurality of second elements, each pixel circuit having a first element and a current control unit, the first element having a first electrode and a second electrode, and a first light-emitting layer positioned between the first electrode and the second electrode, the current control unit having a first terminal and a second terminal connected to the second electrode, the first electrodes of the respective first elements included in the plurality of pixel circuits being connected to each other, the first terminals of the respective current control units included in the plurality of pixel circuits being connected to each other, the second elements receiving reflected light of light emitted from the first elements from a subject, when the illuminance of external light is equal to or less than a first value, the second elements receiving light during the first detection period, during the first detection period, the first elements emitting light at a first luminance, when the illuminance of the external light is higher than the first value, the first elements emitting light at a second luminance higher than the first luminance, and the second elements receiving light during a second detection period shorter than the first detection period, during the second detection period, the first elements emitting light at the second luminance, a difference between a potential of the first terminal and a potential of the first electrode during emission at the second luminance being larger than a difference between the potential of the first terminal and the potential of the first electrode during emission at the first luminance, an electronic device. 　 In claim 3, the current control unit having a first transistor, one of a source and a drain of the first transistor being connected to the first terminal, the other of the source and the drain of the first transistor being connected to the second terminal, an electronic device. 　 In claim 3, the current control unit having a first transistor, When the first element emits light, a potential corresponding to the first terminal is applied to one of the source and the drain of the first transistor, and the current of the first element is controlled by the first transistor. Electronic device. 　 In any one of claims 1 to 5, The product of the first luminance and the length of the first detection period is 0.8 times or more and 1.2 times or less the product of the second luminance and the length of the second detection period. Electronic device. 　 In any one of claims 1 to 5, The subject is a first finger that touches or is close to the surface of the display unit, It has a function of acquiring fingerprint information of the first finger. Electronic device. 　 In any one of claims 1 to 5, It has a storage unit, The subject is a first finger that touches or is close to the surface of the display unit, The storage unit has fingerprint information of a second finger, An electronic device having a function of acquiring fingerprint information of the first finger and a function of collating the fingerprint information of the first finger with the fingerprint information of the second finger. 　 In claim 3, The second element has a third electrode and a fourth electrode, and an active layer located between the third electrode and the fourth electrode. The respective third electrodes of the plurality of second elements are connected to each other. The same potential is applied to the respective third electrodes of the plurality of second elements and the first electrodes of the respective first elements of the plurality of pixel circuits. Electronic device. 　 In claim 9, The second element has a second light-emitting layer. The second light-emitting layer is located between the third electrode and the fourth electrode. Electronic device. 　 In claim 10, The first element has a function of emitting light of one color selected from red, green, and blue. The second element has a function of emitting light of another one color selected from the three colors and a function of receiving visible light. Electronic device. 　 In claim 10, The first element has a function of emitting light of one color selected from red, green, and blue. The second element has a function of emitting light of another one color selected from the three colors and a function of receiving infrared light. Electronic device. 　 In claim 3, The potential of the first electrode when the second luminance emits light is lower than the potential of the first electrode when the first luminance emits light. Electronic device. 　 In claim 3, The potential of the first terminal when the second luminance light emits is higher than the potential of the first terminal when the first luminance light emits. Electronic device. 　 It has a display unit and a camera. The display unit has a plurality of pixel circuits and a plurality of light receiving elements. The pixel circuit has a light emitting element and a current control unit. In the first operation mode, The light receiving element receives the reflected light of the light emitted from the light emitting element from the subject. When the illuminance of external light is equal to or less than a first value, the light emitting element emits light at a first luminance, and the light receiving element receives light during a first detection period. When the illuminance of the external light is higher than the first value, the light emitting element emits light at a second luminance higher than the first luminance, and the light receiving element receives light during a second detection period shorter than the first detection period. In the second operation mode, The light emitting element emits light at a third luminance. Using the light emission at the third luminance as a flashlight, imaging is performed using the camera. The third luminance is lower than the second luminance. Electronic device. 　 In claim 15, The light emitting element has a first electrode and a second electrode, and a light emitting layer located between the first electrode and the second electrode. The current control unit has a first terminal and a second terminal connected to the second electrode. The first electrodes of the respective light emitting elements included in the plurality of pixel circuits are connected to each other. The first terminals of the respective current control units included in the plurality of pixel circuits are connected to each other. The potential difference between the first terminal and the first electrode is larger when the second luminance light emits than when the first luminance light emits. The potential difference between the first terminal and the first electrode is larger when the second luminance light emits than when the third luminance light emits. Electronic device. 　 A program for causing an electronic device to execute. The electronic device has a display unit having a display function and a detection function, and a storage unit. A first step of bringing a first finger into contact with the surface of the display unit or disposing the first finger in proximity to the surface of the display unit. A second step of displaying a first region of a first image on the display unit at a first luminance, detecting the first region of the first image as a light source during a first detection period, and acquiring a first captured image of the first finger. A third step of selecting whether to adopt the first captured image. When the captured image is not adopted in the third step, the first area of the first image is displayed on the display unit at a second luminance higher than the first luminance, and the first area of the first image is used as a light source to perform detection for a second detection period shorter than the first detection period, and a fourth step of obtaining a second captured image of the first finger; A fifth step of selecting whether to adopt the second captured image; A sixth step of extracting fingerprint information of the first finger from the first captured image when the first captured image is adopted in the third step, and extracting fingerprint information of the first finger from the second captured image when the second captured image is adopted in the fifth step; A seventh step of collating the fingerprint information of the first finger extracted in the sixth step with the fingerprint information of the second finger that the storage unit has; having; When the first captured image is adopted in the third step, proceed to the sixth step without performing the fourth step and the fifth step; Program. 　 In claim 17, The product of the first luminance and the length of the first detection period is 0.8 times or more and 1.2 times or less of the product of the second luminance and the length of the second detection period; Program. 　 Having a display unit, a storage unit, and an illuminance sensor; The display unit has a plurality of pixel circuits and a plurality of light receiving elements; The pixel circuit has a light emitting element and a current control unit; The light receiving element receives reflected light from a subject of light emitted from the light emitting element; The storage unit has first biometric information; The illuminance sensor detects illuminance corresponding to external light received by the display unit; When the illuminance detected by the illuminance sensor is equal to or less than a first value, the light receiving element receives light during a first detection period; During the first detection period, the light emitting element emits light at a first luminance; When the illuminance detected by the illuminance sensor is higher than the first value, the light receiving element receives light during a second detection period shorter than the first detection period; During the second detection period, the light emitting element emits light at a second luminance higher than the first luminance; Having a function of obtaining processing content based on an authentication code, and a function of obtaining second biometric information and approving the processing content based on collation with the first biometric information; The authentication code is obtained by detecting, by the plurality of light receiving elements, reflected light from a first subject, which is an image including the authentication code. The second biometric information is obtained by detecting, by the plurality of light receiving elements, reflected light from a second subject, which is a finger or a palm. An electronic device. 　 In claim 19, The light emitting element has a first electrode and a second electrode, and a first light emitting layer positioned between the first electrode and the second electrode. The current control unit has a first terminal and a second terminal connected to the second electrode. The first electrodes of the respective light emitting elements included in the plurality of pixel circuits are connected to each other. The first terminals of the respective current control units included in the plurality of pixel circuits are connected to each other. A difference between a potential of the first terminal and a potential of the first electrode during emission of light of the second luminance is greater than a difference between a potential of the first terminal and a potential of the first electrode during emission of light of the first luminance. An electronic device. 　 In claim 20, The current control unit has a first transistor. One of a source and a drain of the first transistor is connected to the first terminal, and the other of the source and the drain of the first transistor is connected to the second terminal. An electronic device. 　 In claim 20, The current control unit has a first transistor. When the light emitting element emits light, a potential corresponding to the first terminal is applied to one of the source and the drain of the first transistor, and a current of the light emitting element is controlled by the first transistor. An electronic device. 　 In any one of claims 19 to 22, The authentication code is a bar code or a two-dimensional code. An electronic device. 　 In any one of claims 19 to 22, A product of the first luminance and a length of the first detection period is 0.8 times or more and 1.2 times or less a product of the second luminance and a length of the second detection period. An electronic device. 　 In claim 20, The light receiving element has a third electrode and a fourth electrode, and an active layer positioned between the third electrode and the fourth electrode. The respective third electrodes included in the light receiving element are connected to each other. The same potential is applied to each of the third electrodes included in the light receiving element and the first electrodes of the respective light emitting elements included in the plurality of pixel circuits. An electronic device. 　 In claim 25, The light-receiving element has a second light-emitting layer, The second light-emitting layer is located between the third electrode and the fourth electrode, An electronic device. 　 In claim 26, The light-emitting element has a function of emitting light of one color selected from three colors of red, green, and blue, The light-receiving element has a function of emitting light of another one color selected from the three colors and a function of receiving visible light, An electronic device. 　 In claim 26, The light-emitting element has a function of emitting light of one color selected from three colors of red, green, and blue, The light-receiving element has a function of emitting light of another one color selected from the three colors and a function of receiving infrared light, An electronic device. 　 In claim 20, The potential of the first electrode is lower when emitting light of the second luminance than when emitting light of the first luminance, An electronic device. 　 In claim 20, The potential of the first terminal is higher when emitting light of the second luminance than when emitting light of the first luminance, An electronic device. 　 A program for causing an electronic device to execute, The electronic device includes a display unit having a plurality of light-receiving elements and a storage unit, A first step of using an image including an authentication code as a first subject, displaying a first image as a light source on the display unit at a first luminance, and detecting, by the plurality of light-receiving elements, reflected light from the first subject of the light source during a first detection period; A second step of acquiring a captured image of the authentication code using the reflected light detected in the first step; A third step of displaying, on the display unit, first processing content based on the authentication code; A fourth step of bringing a first finger into contact with or disposing it in proximity to the display unit; A fifth step of using the first finger as a second subject, displaying a second image as a second light source on the display unit at a second luminance, and detecting, by the plurality of light-receiving elements, reflected light from the second subject of the second light source during a second detection period; A sixth step of acquiring a captured image of the first finger using the reflected light detected in the fifth step; A seventh step of acquiring fingerprint information of the first finger from the captured image of the first finger and performing collation with fingerprint information of a second finger included in the storage unit; An eighth step of confirming the coincidence between the fingerprint information of the first finger and the fingerprint information of the second finger by the collation and performing the first processing content, and has Verify the image quality of the captured image obtained in the sixth step, and if it is determined that re-acquisition of the captured image is necessary, perform the fifth step and the sixth step again. In the fifth step performed for the second time, compared with the first time, the second luminance is higher and the second detection period is shorter. Program. 　 In claim 31, The product of the first luminance and the length of the first detection period is 0.8 times or more and 1.2 times or less the product of the second luminance and the length of the second detection period. Program.

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