Electronic apparatus

Abstract

To provide an electronic apparatus having a high-security authentication method.SOLUTION: An electronic apparatus has a pixel unit, a sensor unit, an authentication unit, and a housing. The pixel unit has a display element and a light receiving element. The pixel unit has a function of lighting the display element. The pixel unit has a function of photographing, using a light receiving element, an image of an object that touches the pixel unit and acquiring authentication information. The sensor unit has a function of detecting an attachment / detachment state to a living body or an object. The authentication unit has a function of performing, using the authentication information, authentication processing. The housing has a first surface and a second surface opposite to the first surface. The pixel unit is located on the first surface, and the sensor unit is located on the second surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION One aspect of the present invention relates to an electronic device. One aspect of the present invention relates to an authentication method for 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. [Background technology]

[0003] In recent years, information terminal devices such as smartphones and other mobile phones, tablet information terminals, and notebook PCs (personal computers) have become widely used. Wearable information terminal devices that can be attached to the human body are also becoming popular. Such 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. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] US Patent Application Publication No. 2014 / 0056493 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of one embodiment of the present invention is to provide an electronic device having an authentication function typified by fingerprint authentication. Another object is to provide an electronic device with a high level of 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 an authentication method with a high level of security. Another object is to provide an electronic device having a novel authentication method.

[0007] 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. [Means for solving the problem]

[0008] One embodiment of the present invention is an electronic device including a pixel unit, a sensor unit, an authentication unit, and a housing. The pixel unit has a display element and a light-receiving element. The pixel unit has a function of turning on the display element. The pixel unit has a function of capturing an image of an object touching the pixel unit using the light-receiving element and acquiring authentication information. The sensor unit has a function of detecting a state of attachment / detachment to a living body or an object. The authentication unit has a function of performing authentication processing using the authentication information. The housing has a first surface and a second surface opposite to the first surface. The pixel unit is located on the first surface, and the sensor unit is located on the second surface.

[0009] In the electronic device, the pixel portion preferably includes a first transistor that is electrically connected to a display element or a light-receiving element and that has a metal oxide in a channel formation region.

[0010] In the electronic device, the pixel portion preferably includes a first transistor that is electrically connected to a display element or a light-receiving element and that has silicon in a channel formation region.

[0011] In the electronic device, the pixel portion preferably includes a first transistor and a second transistor. The first transistor is electrically connected to a display element or a light-receiving element. The second transistor is electrically connected to the display element or the light-receiving element. The first transistor includes metal oxide in a channel formation region. The second transistor includes silicon in a channel formation region.

[0012] In the electronic device, the pixel portion preferably includes a touch sensor. The touch sensor has a function of detecting the position of an object touching the pixel portion. The pixel portion has a function of lighting up display elements at and near the position.

[0013] In the electronic device, the object is preferably a finger.

[0014] One aspect of the present invention is an authentication method for an electronic device including a pixel unit, a sensor unit, and an authentication unit, where the pixel unit includes a display element and a light-receiving element. The authentication method for the electronic device includes a step in which the sensor unit detects attachment to a living body or an object. The authentication method also includes a step in which the pixel unit turns on the display element. The authentication method also includes a step in which the light-receiving element captures an image of an object that has touched the pixel unit and acquires authentication information. The authentication method also includes a step in which the authentication unit performs authentication processing using the authentication information.

[0015] One embodiment of the present invention is an authentication method for an electronic device including a pixel unit, a sensor unit, and an authentication unit, where the pixel unit includes a display element and a light-receiving element. The authentication method for the electronic device includes a step of the sensor unit acquiring first authentication information. The authentication unit also includes a step of performing first authentication processing using the first authentication information. The authentication method also includes a step of the pixel unit turning on the display element. The authentication method also includes a step of the light-receiving element capturing an image of an object touching the pixel unit and acquiring second authentication information. The authentication unit also includes a step of performing second authentication processing using the second authentication information.

[0016] One aspect of the present invention is a method for authenticating an electronic device that includes a pixel unit, a sensor unit, and an authentication unit, where the pixel unit includes a display element, a light-receiving element, and a touch sensor. The authentication method for the electronic device includes a step in which the sensor unit detects attachment to a living body or an object. The method also includes a step in which the touch sensor detects the position of an object that has touched the pixel unit. The method also includes a step in which the pixel unit lights up a display element at and near the position. The method also includes a step in which the light-receiving element captures an image of the object that has touched the position and near the position, and acquires authentication information. The authentication unit also includes a step in which the authentication unit performs authentication processing using the authentication information. [Effects of the Invention]

[0017] According to one embodiment of the present invention, an electronic device having an authentication function typified by fingerprint authentication can be provided. Alternatively, an electronic device with a high level of security can be provided. Alternatively, an electronic device with high operability can be provided. Alternatively, a multi-functional electronic device can be provided. Alternatively, a novel electronic device can be provided. Alternatively, an electronic device having an authentication method with a high level of security can be provided. Alternatively, an electronic device having a novel authentication method can be provided.

[0018] 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. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of an electronic device. [Figure 2] 2A and 2B are diagrams showing configuration examples of electronic devices. [Figure 3] 3A and 3B are diagrams showing configuration examples of electronic devices. [Figure 4] 4A and 4B are diagrams showing configuration examples of electronic devices. [Figure 5] 5A to 5C are diagrams showing configuration examples of electronic devices. [Figure 6] 6A and 6B are cross-sectional views showing an example of the configuration of a pixel section, Fig. 6C is a diagram showing an example of a captured image, and Figs. 6D to 6F are top views showing an example of a pixel. [Figure 7] Fig. 7A is a cross-sectional view showing an example of the configuration of a pixel section, and Figs. 7B to 7D are top views showing an example of a pixel. [Figure 8] Fig. 8A is a cross-sectional view showing an example of the configuration of a pixel portion, and Figs. 8B to 8I are top views showing an example of a pixel. [Figure 9] Fig. 9A is a cross-sectional view showing an example of the configuration of a pixel unit, and Fig. 9B is a diagram showing an example of a captured image. [Figure 10] 10A to 10C are cross-sectional views showing examples of the configuration of the sensor unit. [Figure 11] FIG. 11 is a flowchart illustrating an example of an authentication method. [Figure 12] FIG. 12 is a diagram illustrating an example of the configuration of an electronic device. [Figure 13] Fig. 13A is a diagram showing an example of the configuration of an electronic device, and Fig. 13B is a diagram showing an example of authentication information. [Figure 14]FIG. 14 is a flowchart illustrating an example of an authentication method. [Figure 15] FIG. 15 is a flowchart illustrating an example of an authentication method. [Figure 16] FIG. 16 is a diagram illustrating an example of the configuration of an electronic device. [Figure 17] FIG. 17 is a flowchart illustrating an example of an authentication method. [Figure 18] Fig. 18A is a diagram showing an example of the configuration of an electronic device, and Fig. 18B is a diagram showing an example of authentication information. [Figure 19] FIG. 19 is a diagram illustrating an example of the configuration of an electronic device. [Figure 20] FIG. 20 is a flowchart illustrating an example of an authentication method. [Figure 21] 21A and 21B are diagrams showing configuration examples of electronic devices. [Figure 22] 22A and 22B are diagrams showing configuration examples of a light emitting element, a light receiving element, and a light receiving / emitting element. [Figure 23] 23A to 23G are diagrams showing configuration examples of a light emitting element, a light receiving element, and a light receiving / emitting element. [Figure 24] 24A to 24C are diagrams showing configuration examples of a light emitting element, a light receiving element, and a light receiving / emitting element. [Figure 25] 25A to 25C are diagrams showing configuration examples of a light emitting element, a light receiving element, and a light receiving / emitting element. [Figure 26] 26A and 26B are diagrams showing configuration examples of a light emitting element, a light receiving element, and a light receiving / emitting element. [Figure 27] Fig. 27A is a diagram showing an example of the configuration of a display device, and Fig. 27B and Fig. 27C are circuit diagrams of pixel circuits. [Figure 28] 28A and 28B are circuit diagrams of pixel circuits. [Figure 29] 29A to 29C are circuit diagrams of pixel circuits. [Figure 30] FIG. 30 is a perspective view showing an example of a display device that can be applied to electronic devices. [Figure 31]FIG. 31 is a cross-sectional view showing an example of a display device that can be applied to electronic equipment. [Figure 32] FIG. 32 is a cross-sectional view showing an example of a display device that can be applied to electronic equipment. [Figure 33] Fig. 33A is a cross-sectional view showing an example of a display device that can be applied to electronic devices, and Fig. 33B is a cross-sectional view showing an example of a transistor. [Figure 34] 34A is a cross-sectional view showing an example of an electronic device, and FIG 34B is a cross-sectional view showing an example of a transistor. [Figure 35] 35A and 35B are diagrams showing an example of an electronic device. DETAILED DESCRIPTION OF THE INVENTION

[0020] 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.

[0021] 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. In addition, when referring to similar functions, the same hatch pattern may be used and no particular reference numeral may be assigned.

[0022] 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.

[0023] In this specification, ordinal numbers such as "first" and "second" are used to avoid confusion of components and do not limit the number.

[0024] In the following description, expressions indicating directions such as "up" and "down" are basically used in accordance with the directions in the drawings. However, for purposes such as facilitating explanation, the directions indicated by "up" or "down" in the specification may not match those in the drawings. For example, when explaining the stacking order (or formation order) of a laminate, etc., even if the surface on which the laminate is provided in the drawing (such as the surface to be formed, the supporting surface, the adhesive surface, or the flat surface) is located above the laminate, the direction may be expressed as "down" and the opposite direction as "up."

[0025] In this specification and the like, a display panel, which is one aspect of a display device, 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.

[0026] In this specification, a display panel having a connector such as an FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) attached to the substrate, or having an IC mounted on the substrate using a COG (Chip On Glass) method or the like, may be referred to as a display panel module, display module, or simply a display panel.

[0027] In this specification and the like, a touch panel, which is one aspect of a display device, has a function of displaying an image or the like on a display surface and a function as a touch sensor that detects that a detectable object such as a finger or a stylus touches, presses, or approaches the display surface. Thus, the touch panel is one aspect of an input / output device.

[0028] 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.

[0029] In this specification and the like, a touch panel substrate on which a connector or an IC is mounted may be called a touch panel module, a display module, or simply a touch panel.

[0030] (Embodiment 1) In this embodiment, an electronic device which is one embodiment of the present invention will be described.

[0031] An electronic device according to one embodiment of the present invention includes a pixel portion, a sensor portion, and an authentication portion.

[0032] The pixel unit has display elements and light-receiving elements arranged in a matrix. Part of the light emitted by the display elements is reflected by an object, and the reflected light is incident on the light-receiving elements. The light-receiving elements can output an electrical signal according to the intensity of the incident light. Therefore, by having light-receiving elements arranged in a matrix, the pixel unit can acquire (or capture) data on the position or shape of an object (subject) that touches or is close to the pixel unit. In other words, the pixel unit not only has the function of displaying an image, but can also function as an image sensor panel or an optical sensor.

[0033] The pixel unit has a function of capturing an image of an object that touches the pixel unit using a light-receiving element and acquiring authentication information. The sensor unit has a function of acquiring information on the attachment / detachment state of the electronic device to a living body or an object. The authentication unit has a function of performing authentication processing using the authentication information. The electronic device of one embodiment of the present invention can increase the security level by performing authentication processing while attached to a living body or an object.

[0034] The object to be imaged may be, for example, a finger, a palm, etc. When the object is a finger, a fingerprint image may be used as the authentication information. When the object is a palm, a palm print image may be used as the authentication information.

[0035] <Electronic device configuration example 1> FIG. 1 shows a block diagram of an electronic device 10 according to one embodiment of the present invention. The electronic device 10 includes a control unit 401, a pixel unit 402, a sensor unit 403, and a storage unit 404. The control unit 401 includes an authentication unit 407. The pixel unit 402 includes a display element 405 and a light-receiving element 406. The electronic device 10 can be used, for example, as a portable information terminal that can be attached to a living body or an object. The electronic device 10 can be suitably used, for example, as a wearable portable information terminal that can be attached to a human or an animal. When the electronic device 10 is attached to a living body, it can be attached to, for example, a wrist, an arm, a finger, or a foot.

[0036] In the drawings attached to this specification, the components are classified by function and shown as block diagrams that are independent of each other; however, in reality, it is difficult to completely separate the components by function, and one component may be involved in multiple functions, or one function may be realized by multiple components.

[0037] The control unit 401 has a function of performing overall control of the system of the electronic device 10. The control unit 401 also has a function of controlling each component of the electronic device 10 in an integrated manner.

[0038] The control unit 401 functions as, for example, a central processing unit (CPU). The control unit 401 performs various data processing or program control by interpreting and executing instructions 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.

[0039] The control unit 401 has functions such as processing first information input from the sensor unit 403, generating image data to be output to the pixel unit 402, processing second information input from the light receiving element 406 of the pixel unit 402, and controlling the lock state of the electronic device 10.

[0040] The sensor unit 403 has a function of acquiring information (first information) on the attachment / detachment state of the electronic device 10 and outputting the first information to the control unit 401. The attachment / detachment state information refers to information on whether the electronic device 10 is attached to or detached from a living body or an object. The sensor unit 403 may be an optical sensor, an ultrasonic sensor, or the like. The sensor unit 403 may be configured with the display element 405 and the light receiving element 406 described above.

[0041] The pixel unit 402 has a function of displaying an image using the display element 405 based on image data input from the control unit 401. The pixel unit 402 can also capture an image of an object (subject) that touches or is close to the pixel unit 402. For example, part of the light emitted by the display element 405 is reflected by the object, 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, and the pixel unit 402 has a plurality of light receiving elements 406 arranged in a matrix, so that it can acquire (capture) position information and shape of the object as data. It can be said that the pixel unit 402 functions as an image sensor panel or an optical sensor.

[0042] The pixel portion 402 has a function of acquiring second information using the light receiving element 406 and outputting the second information to the control unit 401. For example, an image of a fingerprint of a user who touches the pixel portion 402 (also referred to as a captured image or captured data) can be used as the second information. The pixel portion 402 can acquire the second information by capturing an image of the fingerprint of the user who touches the pixel portion 402 using the light receiving element 406.

[0043] For example, by configuring the display element 405 to emit red (R), green (G), and blue (B) light and the light receiving element 406 to receive the light of each color reflected by the object, the pixel unit 402 can obtain color information of the object. With this configuration, color information can be included in the second information. For example, if the object is a finger, skin color information can be used as the second information in addition to fingerprint information.

[0044] The display element 405 may be, for example, a liquid crystal element or a light-emitting element. The display element 405 may suitably be a light-emitting element. The light-emitting element may be a self-luminous light-emitting element such as an LED (Light Emitting Diode), an OLED (Organic Light Emitting Diode), a QLED (Quantum-dot Light Emitting Diode), or a semiconductor laser. Examples of light-emitting materials that the light-emitting element may have include fluorescent materials (fluorescent materials), phosphorescent materials (phosphorescent materials), materials that exhibit thermally activated delayed fluorescence (thermally activated delayed fluorescence: TADF materials), and inorganic compounds (e.g., quantum dot materials).

[0045] The light-receiving element 406 can be, for example, a pn-type or pin-type photodiode. The light-receiving element 406 functions as a photoelectric conversion element that detects light incident on the light-receiving element and generates electric charges. The amount of electric charges generated by the photoelectric conversion element is determined according to the amount of incident light. 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-area, and have a high degree of freedom in shape and design, and therefore can be applied to various display devices.

[0046] An organic compound is preferably used for the active layer of the light-receiving element 406. In this case, one electrode (also referred to as a pixel electrode) of the display element 405 and the light-receiving element 406 is preferably provided on the same surface. Furthermore, it is more preferable that the other electrode of the display element 405 and the light-receiving element 406 be an electrode (also referred to as a common electrode) formed of one continuous conductive layer. Furthermore, it is more preferable that the display element 405 and the light-receiving element 406 have a common layer. This can simplify the manufacturing process for manufacturing the display element 405 and the light-receiving element 406, reduce manufacturing costs, and improve manufacturing yield.

[0047] The storage unit 404 has a function of storing pre-registered user information. For example, fingerprint information of the user 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 unit 401.

[0048] It is preferable that the storage unit 404 stores fingerprint information for all fingers that the user uses for authentication. For example, 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, can be stored. The user can freely register fingerprint information for one or more of the index finger, middle finger, ring finger, little finger, and thumb, and the storage unit 404 can store information for all registered fingerprints.

[0049] The control unit 401 has a function of, when authentication is successful in the user authentication performed by the authentication unit 407, transitioning the system from a locked state to a state in which the system is unlocked and the electronic device 10 can be used.

[0050] The control unit 401 has a function of turning on the display element 405 of the pixel unit 402 when detecting an operation on the electronic device 10 while the system of the electronic device 10 is in a locked state. Furthermore, the control unit 401 has a function of requesting the pixel unit 402 to capture an image of a fingerprint with the display element 405 turned on.

[0051] The control unit 401 may have a function to generate image data including an image indicating the position to be touched by the user (also called an image informing the touch position) in the pixel unit 402 when the system of the electronic device 10 is in a locked state, and output the image data to the pixel unit 402.

[0052] The authentication unit 407 has a function of executing a process (authentication process) of comparing the second information input from the pixel unit 402 with the fingerprint information stored in the storage unit 404 and determining whether or not they match. The second information can be said to be information used for authentication (authentication information).

[0053] 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 endpoints and bifurcations of image patterns. The authentication process can also use inference using machine learning. In this case, it is preferable that the authentication process is performed by inference using a neural network.

[0054] The electronic device 10 according to one embodiment of the present invention can be made into an electronic device with a high security level by performing authentication processing while attached to a living body or an object. Furthermore, the electronic device can be made into an electronic device with an even higher security level by locking the electronic device when it detects that it has been removed from the living body or the object.

[0055] If the authentication information includes color information, the authentication process may be performed using the color information. By using color information in addition to fingerprint information in the authentication process, the electronic device can be made to have a higher security level.

[0056] An electronic device 420 to which the electronic device 10 is applied will be described with reference to FIGS. 2A, 2B, 3A, 3B, 4A, and 4B.

[0057] The electronic device 420 has a housing 431, a pixel unit 422, and a sensor unit 403. The electronic device 420 has a control unit 401 and a memory unit 404 inside the housing 431. The pixel unit 402 described above can be applied to the pixel unit 422. Fig. 2A shows the electronic device 420 worn on the wrist.

[0058] The housing 431 has a first surface and a second surface opposite to the first surface. It is preferable that the pixel unit 422 is provided on the first surface, and the sensor unit 403 is provided on the second surface. Fig. 4A is a perspective view showing the appearance of the first surface (pixel unit 422) side of the electronic device 420. Fig. 4B is a perspective view showing the appearance of the second surface (sensor unit 403) side of the electronic device 420. The sensor unit 403 is provided on the second surface, and thereby detects the attachment / detachment state of the electronic device 420.

[0059] 2A shows an example in which the pixel portion 422 of the electronic device 420 is rectangular, but the shape of the pixel portion 422 is not particularly limited. When the pixel portion 422 has a shape other than rectangular, the design of the electronic device 420 can be improved. As shown in FIG. 2B, the pixel portion 422 may be circular. As shown in FIG. 3A, the pixel portion 422 may have a curved display surface, and display may be performed along the curved display surface. Furthermore, as shown in FIG. 3B, the electronic device 420 may have a cylindrical shape. FIG. 3B shows a state in which the electronic device 420 is worn on a finger 462.

[0060] The electronic device 420 may have an operation button 433. A user can operate the electronic device 420 by pressing the operation button 433. 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. Although FIG. 2A and other figures show a configuration in which the electronic device 420 has the operation button 433, the electronic device 420 may not have the operation button 433. Furthermore, FIG. 4A and other figures show 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.

[0061] The electronic device 420 may have one or more of a speaker, a microphone, and a camera. The electronic device 420 may also have one or more of a speaker, a microphone, a camera, and a sensor (including a function to measure 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).

[0062] 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 from other information terminals or charge itself via a connection terminal (not shown). Charging may be performed by wireless power supply.

[0063] Schematic diagrams of electronic device 420 are shown in FIGS. 5A to 5C. FIGS. 5A and 5B are cross-sectional views taken along dashed line AB in FIG. 2. FIG. 5C is a cross-sectional view taken along dashed line CD in FIG. 3A. FIGS. 5B and 5C show enlarged views of housing 431, pixel unit 422, and sensor unit 403. Note that FIGS. 5A to 5C omit operation button 433 and fastener 437.

[0064] Electronic components such as a communication antenna and a storage battery can be provided in the space inside the housing 431. The control unit 401 and the storage unit 404 may also be provided in this space.

[0065] The sensor unit 403 can acquire information (first information) about the attached / detached state of the electronic device 420 when a portion of the emitted light is reflected by a living body or an object and the reflected light enters the sensor unit 403. In FIG. 5B, the light emitted from the pixel unit 422 and the light emitted from the sensor unit 403 are respectively indicated by arrows. As shown in FIG. 5B, it is preferable that the light emitted from the pixel unit 422 and the light emitted from the sensor unit 403 are in opposite directions. Note that while FIG. 5A 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.

[0066] As shown in FIG. 5C, the pixel portion 422 may have a curved display surface, and display may be performed along the curved display surface.

[0067] The configuration of the pixel portion 422 will be described.

[0068] [Pixel section configuration example 1] 6A shows a schematic diagram of a display device 200 that can be used for the pixel portion 422. The pixel portion 422 includes a substrate 471, a substrate 472, a light receiving element 406, a display element 405R, a display element 405G, a display element 405B, a functional layer 473, and the like.

[0069] Wearable electronic devices may be damaged if dropped when worn or removed. Therefore, it is preferable that the thickness of the substrate 472 be thick. The thicker the substrate 472, the greater the mechanical strength of the electronic device 420. However, a thick substrate 472 increases the distance between the light receiving element 406 and the object, which can blur the captured image and prevent clear imaging. Therefore, the thickness of the substrate 472 is preferably within a range that achieves both clear imaging and high mechanical strength. The thickness of the substrate 472 is preferably 0.1 mm or more, more preferably 0.2 mm to 5 mm, even more preferably 0.5 mm to 3 mm, and even more preferably 0.7 mm to 2 mm. Typically, the thickness of the substrate 472 can be 0.5 mm, 0.7 mm, 1.0 mm, 1.3 mm, or 1.5 mm.

[0070] Display element 405R, display element 405G, display element 405B, and light receiving element 406 are provided between substrate 471 and substrate 472. Display element 405R, display element 405G, and display element 405B emit red (R), green (G), or blue (B) light, respectively. Note that hereinafter, when there is no need to distinguish between display element 405R, display element 405G, and display element 405B, they may be referred to as display element 405.

[0071] The display device 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 further has a light-receiving element 406. The light-receiving element 406 may be provided in all pixels or in some of the pixels. Alternatively, one pixel may have multiple light-receiving elements 406.

[0072] 6A shows a state in which finger 463 touches the surface of substrate 472. A part of the light emitted by display element 405G is reflected at the contact point between substrate 472 and finger 463. Then, a part of the reflected light is incident on light receiving element 406, thereby making it possible to detect that finger 463 has touched substrate 472. In other words, display device 200 can function as a touch panel.

[0073] The functional layer 473 includes circuits for driving the display element 405R, the display element 405G, and the display element 405B, and a circuit for driving the light receiving element 406. The functional layer 473 includes a switch, a transistor, a capacitor, a wiring, and the like.

[0074] The semiconductor layer of the transistor included in the functional layer 473 preferably contains a metal oxide (also referred to as an oxide semiconductor). Alternatively, the semiconductor layer of the transistor may contain silicon. Examples of silicon include amorphous silicon and crystalline silicon (for example, low-temperature polysilicon and single-crystal silicon). Different semiconductor materials may be used for the semiconductor layers in which the channels of the transistors are formed. The functional layer 473 may include, for example, a transistor containing silicon (hereinafter also referred to as a Si transistor) and a transistor containing metal oxide (hereinafter also referred to as an OS transistor).

[0075] OS transistors have significantly higher field-effect mobility than transistors using amorphous silicon. Furthermore, OS transistors have significantly smaller source-drain leakage current (hereinafter also referred to as off-state current) in an off state, and can retain charge accumulated in a capacitor connected in series with the transistor for a long period of time. Use of OS transistors enables a display device with low power consumption. Transistors using low-temperature polysilicon (LTPS) (hereinafter also referred to as LTPS transistors) have high field-effect mobility and favorable frequency characteristics. Use of LTPS transistors enables a display device with high operating speed. By including transistors with different semiconductor layer materials, the display device 200 can be a high-performance electronic device that takes advantage of the advantages of each transistor.

[0076] Note that when the display elements 405R, 405G, and 405B and the light receiving element 406 are driven by a passive matrix method, a configuration without switches and transistors may be used.

[0077] It is preferable that display device 200 has a function of detecting the fingerprint of finger 463. Fig. 6B is a schematic enlarged view of a contact portion when finger 463 is in contact with substrate 472. Fig. 6B also shows display elements 405 and light receiving elements 406 arranged alternately.

[0078] A fingerprint is formed by concave and convex portions of finger 463. Therefore, the convex portions of the fingerprint are in contact with substrate 472 as shown in FIG.

[0079] Light reflected from a surface or interface can be classified as specular reflected light or diffuse reflected light. Specular reflected light is highly directional light in which the angle of incidence and the angle of reflection are the same, while diffuse reflected light is low-directional light in which the intensity is less dependent on the angle. Of the specular and diffuse reflected light, the diffuse reflected component is dominant in the light reflected from the surface of the finger 463. On the other hand, the specular reflected component is dominant in the light reflected from the interface between the substrate 472 and the air.

[0080] The intensity of light reflected by the contact or non-contact surface between finger 463 and substrate 472 and incident on light receiving element 406 located directly below them is the sum of specularly reflected light and diffusely reflected light. As described above, at the concave portions of finger 463, substrate 472 and finger 463 do not come into contact, so specularly reflected light (indicated by solid arrows) is dominant, whereas at the convex portions, they come into contact, so diffusely reflected light (indicated by dashed arrows) from finger 463 is dominant. Therefore, the intensity of light received by light receiving element 406 located directly below the concave portions is higher than that of light receiving element 406 located directly below the convex portions. This makes it possible to capture an image of the fingerprint of finger 463.

[0081] A clear fingerprint image can be obtained by arranging the light receiving elements 406 at an interval smaller than the distance between two convex portions of a fingerprint, preferably the distance between adjacent concave and convex portions. Since the distance between concave and convex portions of a human fingerprint is generally between 150 μm and 250 μm, the interval between the light receiving elements 406 is set to, for example, 400 μm or less, preferably 200 μm or less, more preferably 150 μm or less, even more preferably 120 μm or less, even more preferably 100 μm or less, and even more preferably 50 μm or less. The smaller the arrangement interval, the better, but it can be set to, for example, 1 μm or more, 10 μm or more, or 20 μm or more.

[0082] An example of a fingerprint image captured by display device 200 is shown in Fig. 6C. In Fig. 6C, the outline of finger 463 is indicated by a dashed line and the outline of contact portion 469 is indicated by a dashed line in first region 425. In first region 425, a fingerprint 467 with high contrast can be captured due to differences in the amount of light incident on light receiving element 406.

[0083] An example of a pixel applicable to the display device 200 is shown in FIGS. 6D to 6F.

[0084] 6D and 6E each include a red (R) display element 405R, a green (G) display element 405G, a blue (B) display element 405B, and a light receiving element 406. Each pixel also includes a pixel circuit for driving the display element 405R, the display element 405G, the display element 405B, and the light receiving element 406.

[0085] Fig. 6D shows an example in which three light-emitting elements and one light-receiving element are arranged in a 2 x 2 matrix. Fig. 6E shows an example in which three light-emitting elements are arranged in a row, and one horizontally long light-receiving element 406 is arranged below them.

[0086] The pixel shown in Fig. 6F is an example having a white (W) display element 405W. Here, four light-emitting elements are arranged in a row, and a light-receiving element 406 is arranged below them.

[0087] Note that the pixel configuration is not limited to the above, and various arrangement methods can be adopted. Although the examples in which the areas of the subpixels are equal are shown in Figures 6D to 6F, one embodiment of the present invention is not limited to this. The areas of the subpixels may be different.

[0088] [Pixel section configuration example 2] In the following, an example of a configuration 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.

[0089] The display device 200A shown in Fig. 7A includes a display element 405IR in addition to the configuration exemplified in Fig. 6A. The display element 405IR 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 display element 405IR as the light-receiving element 406. It is more preferable to use an element that can receive both visible light and infrared light as the light-receiving element 406.

[0090] As shown in FIG. 7A, when a finger 463 touches the substrate 472, infrared light IR emitted from the display element 405IR is reflected by the finger 463, and a portion of the reflected light is incident on the light receiving element 406, thereby obtaining position information of the finger 463.

[0091] An example of a pixel applicable to the display device 200A is shown in FIGS. 7B to 7D.

[0092] Fig. 7B shows an example in which three light-emitting elements are arranged in a row, and below them, a display element 405IR and a light-receiving element 406 are arranged side by side. Fig. 7C shows an example in which four light-emitting elements including a display element 405IR are arranged in a row, and below them, a light-receiving element 406 is arranged.

[0093] FIG. 7D shows an example in which three light-emitting elements and a light-receiving element 406 are arranged on all four sides with a display element 405IR at the center.

[0094] In the pixels shown in FIGS. 7B to 7D, the positions of the light-emitting elements and the light-emitting elements and the light-receiving elements can be interchanged.

[0095] [Pixel section configuration example 3] In the following, an example of a configuration 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.

[0096] The display device 200B shown in FIG. 8A includes a display element 405B, a display element 405G, and an optical element 413R. The optical element 413R functions as a light-emitting element that emits red (R) light and as a photoelectric conversion element that receives visible light. FIG. 8A shows an example in which the optical element 413R receives green (G) light emitted by the display element 405G. The optical element 413R may also receive blue (B) light emitted by the display element 405B. The optical element 413R may also receive both green and blue light.

[0097] For example, it is preferable that the light receiving / emitting element 413R receives light with a shorter wavelength than the light it emits. Alternatively, the light receiving / emitting element 413R may be configured to receive light with a longer wavelength than the light it emits (for example, infrared light). The light receiving / emitting element 413R 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 413R is configured so that the peak of the emission spectrum and the peak of the absorption spectrum do not overlap as much as possible.

[0098] 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.

[0099] In this way, by making the light emitting / receiving element 413R 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.

[0100] An example of a pixel applicable to the display device 200B is shown in FIGS. 8B to 8I.

[0101] Fig. 8B shows an example in which light emitting / receiving element 413R, display element 405G, and display element 405B are arranged in a row. Fig. 8C shows an example in which display elements 405G and 405B are arranged alternately in the vertical direction, and light emitting / receiving element 413R is arranged next to them.

[0102] FIG. 8D shows an example in which three light-emitting elements (display element 405G, display element 405B, and display element 405X) and one light-receiving / light-emitting element are arranged in a 2×2 matrix. Display element 405X 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 display element 405X emits infrared light, the light-receiving / light-emitting element preferably has the function of detecting infrared light or the function of detecting 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.

[0103] FIG. 8E shows two pixels. An area including three elements surrounded by a dotted line corresponds to one pixel. Each pixel has a display element 405G, a display element 405B, and an optical element 413R. In the left pixel shown in FIG. 8E, the display element 405G is arranged in the same row as the optical element 413R, and the display element 405B is arranged in the same column as the optical element 413R. In the right pixel shown in FIG. 8E, the display element 405G is arranged in the same row as the optical element 413R, and the display element 405B is arranged in the same column as the optical element 405G. In the pixel layout shown in FIG. 8E, the optical element 413R, the display element 405G, and the display element 405B are arranged alternately in both odd-numbered and even-numbered rows, and in each column, optical elements or optical elements of different colors are arranged in the odd-numbered and even-numbered rows.

[0104] Figure 8F shows four pixels in a Pentile arrangement, with adjacent pixels each having a light-emitting or light-receiving element that emits two different colors of light. Figure 8F also shows the top view of the light-emitting or light-receiving element.

[0105] The upper left pixel and the lower right pixel shown in Fig. 8F have a light emitting / receiving element 413R and a display element 405G. The upper right pixel and the lower left pixel have a display element 405G and a display element 405B. That is, in the example shown in Fig. 8F, a display element 405G is provided in each pixel.

[0106] The top surface shapes of the light-emitting element and light-receiving / light-emitting element are not particularly limited and may be circular, elliptical, polygonal, polygonal with rounded corners, etc. Figure 8F etc. shows an example in which the top surface shapes of the light-emitting element and 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 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.

[0107] 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 each other, or may be the same for some or all colors. For example, in FIG. 8F, the area of ​​the light-emitting region of the display element 405G provided in each pixel may be smaller than the light-emitting regions (or light-receiving regions) of the other elements.

[0108] Fig. 8G is a modified example of the pixel array shown in Fig. 8F. Specifically, the configuration in Fig. 8G is obtained by rotating the configuration in Fig. 8F by 45 degrees. Although Fig. 8F 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. 8G.

[0109] FIG. 8H is a modified example of the pixel array shown in FIG. 8F. The upper left pixel and lower right pixel shown in FIG. 8H have an optical element 413R and a display element 405G. The upper right pixel and lower left pixel have an optical element 413R and a display element 405B. That is, in the example shown in FIG. 8H, each pixel is provided with an optical element 413R. Because each pixel is provided with an optical element 413R, the configuration shown in FIG. 8H can capture images with higher resolution than the configuration shown in FIG. 8F. This can improve the accuracy of biometric authentication, for example.

[0110] FIG. 8I is a modified example of the pixel array shown in FIG. 8H, and is obtained by rotating the pixel array by 45 degrees.

[0111] In FIG. 8I, a description will be given assuming that one pixel is composed of four elements (two light-emitting elements and two light-receiving and light-emitting elements). In this way, one pixel has multiple light-receiving and light-emitting elements with a light-receiving function, allowing for high-resolution imaging. This can improve the accuracy of biometric authentication. For example, the resolution of imaging can be set to the root double of the resolution of display.

[0112] A display device to which the configuration shown in Figure 8H or Figure 8I 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.

[0113] 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.

[0114] As described above, pixels with various arrangements can be applied to the display device of this embodiment mode.

[0115] The display device 200, the display device 200A, and the display device 200B described above can also function as a touch panel or a pen tablet. Fig. 9A shows a state in which the tip of a stylus 475 is in contact with a substrate 472 and is slid in the direction of the dashed arrow.

[0116] As shown in FIG. 9A, the diffused reflected light scattered by the tip of stylus 475 and the contact surface of substrate 472 is incident on light receiving element 406 located at the portion overlapping the contact surface, thereby enabling the position of the tip of stylus 475 to be detected with high accuracy.

[0117] 9B shows an example of a trajectory 477 of a stylus 475 detected by display device 200. Display device 200 is capable of detecting the position of a detectable object such as stylus 475 with high positional accuracy, and therefore is also capable of performing high-resolution drawing in drawing applications, etc. Furthermore, unlike when a capacitance-type touch sensor, an electromagnetic induction-type touch pen, or the like is used, it is possible to detect the position of even a highly insulating detectable object, and therefore the material of the tip of stylus 475 does not matter, and various writing implements (for example, a brush, a glass pen, or a feather pen) can be used.

[0118] The configuration of the sensor unit 403 will be described.

[0119] [Example of sensor configuration] 10A shows a schematic diagram of the sensor unit 403. The sensor unit 403 has a light receiving element 439 and a light emitting element 438. The light emitting element 438 can be a light emitting element that emits visible light or a light emitting element that emits infrared light. The light emitting element 438 may have the same structure as the display element 405. The light receiving element 439 may have the same structure as the light receiving element 406.

[0120] A part of the light emitted by light-emitting element 438 is reflected by an object (for example, wrist 461), and the reflected light is incident on light-receiving element 439, thereby making it possible to obtain information (first information) on the wearing / detaching state of electronic device 420. FIG. 10A shows a state in which a part of the light emitted by light-emitting element 438 is reflected by an object (for example, wrist 461), and the reflected light is incident on light-receiving element 439.

[0121] For example, by using a light-emitting element that emits infrared light as light-emitting element 438, it is possible to obtain data relating to the user's health, such as vein shape, pulse wave, blood glucose level, cholesterol concentration in the blood, and triglyceride concentration. For example, by using a light-emitting element that emits green light as light-emitting element 438, it is possible to measure the pulse wave. By using a light-emitting element that emits green light as light-emitting element 438, it is possible to measure the pulse wave with high sensitivity even in an environment with a lot of infrared rays, such as outdoors.

[0122] 10B shows how part of the light emitted by light-emitting element 438 passes through blood vessel 465, and the reflected light reflected by biological tissue enters light-receiving element 439. The health-related data acquired by sensor unit 403 may also serve as information (first information) on the wearing / removing state of electronic device 420. For example, if the acquired blood glucose level is within a range registered by the user, it can be determined that electronic device 420 is being worn on the human body.

[0123] The sensor unit 403 may have a plurality of light-emitting elements 438. The sensor unit 403 may also have a plurality of light-emitting elements 438 that emit light of different wavelengths. FIG. 10C shows a configuration in which the sensor unit 403 has a light-emitting element 438a and a light-emitting element 438b. For example, by using a light-emitting element that emits red light as the light-emitting element 438a and a light-emitting element that emits infrared light as the light-emitting element 438b, it is possible to measure the oxygen saturation level in the blood. For example, by using a light-emitting element that emits green light as the light-emitting element 438a and a light-emitting element that emits infrared light as the light-emitting element 438b, it is possible to measure the pulse wave with high sensitivity.

[0124] The sensor unit 403 may have a plurality of light receiving elements 439. When the sensor unit 403 has a plurality of light receiving elements 439, it is possible to acquire information on the attachment / detachment state (first information) with high sensitivity. When a plurality of light emitting elements 438 that emit light of different wavelengths are used in the sensor unit 403, the sensor unit 403 may have a plurality of types of light receiving elements 439 corresponding to the wavelengths of light emitted from the respective light emitting elements 438.

[0125] When health-related data is acquired by the sensor unit 403, authentication processing may be performed using the data. By performing multi-stage authentication (hereinafter also referred to as multi-stage authentication) including authentication processing using health-related data acquired by the sensor unit 403 and authentication processing using the second information described above, an electronic device with a higher security level can be obtained.

[0126] Although the sensor unit 403 has been described using an example in which the electronic device 420 is attached to a living body (human body), information on the attachment / detachment state (first information) can be obtained in the same way when the electronic device 420 is attached to an object. The data acquired by the sensor unit 403 differs depending on the material of the object to which the electronic device 420 is attached. Therefore, by performing authentication processing using the data acquired by the sensor unit 403, it is possible to prevent the electronic device 420 from being used in a location other than the installation location. This makes it possible to prevent the electronic device 420 from being used fraudulently due to theft.

[0127] <Authentication method example 1> The following describes an example of an authentication method using electronic device 420. Here, the operation of electronic device 420 being worn on the wrist of a human body and authenticating a user using a fingerprint as an authentication method will be described.

[0128] FIG. 11 shows a flowchart of the operation of the authentication method using electronic device 420.

[0129] First, the process starts. At this time, the system of the electronic device 420 is locked, and the functions that the user can execute are limited (including a logged-out state and a logged-off state).

[0130] In step S11, it is detected that the electronic device 420 is worn by the user. The sensor unit 403 is used to detect the wearing of the electronic device. If the wearing of the electronic device is detected, the process proceeds to step S12 ("Yes" in step S11). Step S11 is repeatedly executed until the wearing of the electronic device is detected ("No" in step S11).

[0131] Next, in step S12, a user operation on the electronic device 420 is detected. Methods for detecting a user operation include, for example, turning on the power of the electronic device 420, pressing the operation button 433, detecting the user's line of sight, an increase in ambient light, or a large change in the posture of the electronic device 420. If an operation is detected, the process proceeds to step S13 ("Yes" in step S12). Step S12 is repeatedly executed until an operation is detected ("No" in step S12).

[0132] Subsequently, in step S13, the display elements 405 included in the pixel unit 422 are turned on. Light emitted from the display elements 405 can be used as a light source when capturing an image with the light receiving elements 406. Therefore, the turned on display elements 405 can be display elements that emit light that can be received by the light receiving elements 406. For example, if the pixel unit 422 has display elements 405 of three colors, red (R), green (G), and blue (B), any one, any two, or all three of these display elements 405 can be turned on.

[0133] In step S13, all the display elements 405 of the pixel portion 422 may be turned on, or some of the display elements 405 of the pixel portion 422 may be turned on. In this specification and the like, the region from which the second information (authentication information) is acquired may be referred to as the first region. FIG. 12 shows an example in which all the display elements 405 of the pixel portion 422 are turned on, that is, the entire surface of the pixel portion 422 is the first region 425. The user can be authenticated by touching the first region 425. When the entire surface of the pixel portion 422 is the first region 425, the user can be authenticated by touching any region of the pixel portion 422.

[0134] When part of the display elements 405 of the pixel portion 422 is turned on, that is, when part of the pixel portion 422 is used as the first region 425, the user can perform authentication by touching the first region 425. The display elements 405 other than the first region 425 may be turned off. The light-emitting display elements 405 in the first region 425 that are turned on are covered by the finger 463, so that the user can be prevented from viewing the bright light. That is, the user can be prevented from directly viewing the light for authentication. For example, in a dark environment, if the user were to directly view the light for authentication, the user would feel dazzled and there is a risk of the light damaging their eyes. Therefore, by turning on only the first region 425, the burden on the user can be reduced. Note that any image may be displayed in a region other than the first region 425.

[0135] In step S13, the brightness of the illuminated display element 405 can be changed as appropriate depending on the brightness of the usage environment or the sensitivity of the light receiving element 406, but it is preferable to illuminate it as brightly as possible. For example, if the brightness or gradation value when the display element 405 is illuminated most brightly is 100%, the brightness or gradation value can be set to 50% or more and 100% or less, preferably 70% or more and 100% or less, and more preferably 80% or more and 100% or less.

[0136] Subsequently, in step S14, authentication information is acquired using the light receiving element 406. The authentication information is output from the pixel unit 422 to the control unit 401 as image data (first image data) captured by the light receiving element 406. The region where the image is captured can be the first region 425.

[0137] In step S13, when all display elements 405 of pixel unit 422 are turned on, that is, when the entire surface of pixel unit 422 is used as first region 425, all light receiving elements 406 of pixel unit 422 are operated to acquire authentication information. Fig. 13A shows how a finger 463a is touched to first region 425 to capture an image of a fingerprint as first image data. Fig. 13B shows an example of image data of the captured fingerprint (first image data) as authentication information 451a.

[0138] In step S13, when part of the display elements 405 of the pixel portion 422 is turned on, that is, when part of the pixel portion 422 is set as the first region 425, the light receiving elements 406 in the first region 425 are operated to acquire authentication information. The first region can be said to be part of the pixel portion 422. Note that even when part of the pixel portion 422 is set as the first region 425 in step S13, all of the light receiving elements 406 in the pixel portion 422 may be operated to acquire authentication information.

[0139] When a part of the pixel portion 422 is set as the first region 425 in step S13, the position of the first region 425 may be the same each time the process is executed, but it is preferable that the position be different each time the process is executed. That is, each time the process is executed, the user can be made to touch a location that is randomly displayed in a different position, and authentication can be performed.

[0140] For example, if a fingerprint is captured at the same position every time, the display element 405, which is turned on as a light source for capturing a fingerprint, and the transistors constituting the pixels are likely to deteriorate, which may result in problems such as a decrease in the luminance of the display element 405 and image burn-in on the screen. Therefore, by performing fingerprint authentication at a different position every time the process is executed as described above, it is possible to suppress a decrease in the luminance of the display element 405, image burn-in on the screen, and the like.

[0141] By performing fingerprint authentication at a different position each time a process is executed, the user is required to actively perform an action for authentication, which can improve the user's security awareness.

[0142] It is also possible to provide a plurality of first regions 425 in the pixel portion 422, touch the area with two or more fingers at the same time, and perform authentication based on two or more pieces of fingerprint information. Alternatively, authentication may be performed multiple times, for example, by performing authentication with one finger, and then performing authentication with a different finger after the authentication is successful.

[0143] By performing authentication using multiple pieces of fingerprint information instead of using only one piece of fingerprint information, it is possible to provide a high-security electronic device 420. For example, even if a malicious user fraudulently obtains the fingerprint information of a true user (owner) and uses electronic device 420, the electronic device 420 cannot be used unless the fingerprint information of multiple (preferably all) fingers is available, and therefore fraudulent use can be suitably prevented.

[0144] When authentication is performed multiple times, the processes from step S13 to step S15 can be performed multiple times. For example, when performing two-step authentication, the authentication process can be performed using the fingerprint of the middle finger of the right hand in the first process, and if authentication is successful, the authentication process can be performed using the fingerprint of the ring finger of the right hand in the second process, and if authentication is successful, the system can be unlocked. It is also preferable to randomly change the fingers used in the first and second processes for each process.

[0145] Next, in step S15, authentication unit 407 executes authentication processing. Specifically, authentication unit 407 compares the authentication information (first image data) output from pixel unit 422 with the user's fingerprint information that has been registered in advance and stored in storage unit 404, and determines whether they match. If authentication is successful, that is, if it is determined that the authentication information matches the user's fingerprint information, the process proceeds to step S16 ("Yes" in step S15). If authentication is not successful, that is, if it is determined that the authentication information does not match the user's fingerprint information, the process ends ("No" in step S15). Note that if two or more pieces of fingerprint information are stored in storage unit 404, authentication processing is executed for all of the fingerprint information.

[0146] Subsequently, in step S16, the control unit 401 transitions the system of the electronic device 420 to an unlocked state (including a logged-in state). By unlocking the system of the electronic device 420, the user can perform operations such as starting an application on the electronic device 420.

[0147] Next, in step S17, it is detected that the electronic device 420 has been removed from the user. The sensor unit 403 is used to detect the removal. If the removal is detected, the process proceeds to step S18 ("Yes" in step S17). Step S17 is repeatedly executed until it is detected that the electronic device 420 has been removed from the user ("No" in step S17).

[0148] Subsequently, in step S18, the system of the electronic device 420 is locked, and the electronic device 420 enters a state in which the functions that the user can execute are restricted (including a logout state and a logoff state).

[0149] This concludes the description of the flowchart shown in FIG.

[0150] The electronic device 420 of one embodiment of the present invention can achieve an extremely high level of security by acquiring information on the attachment / detachment state using the sensor unit 403 and further acquiring authentication information using the light-receiving element 406 for authentication. For example, even when a malicious user illegally acquires fingerprint information of a true user (owner) and uses the electronic device 420, unauthorized use can be suitably prevented.

[0151] Applications that do not include personal information, such as time display, may be configured to be usable without the above-mentioned authentication. It is preferable that the user can set whether or not to perform authentication for each application. By being able to set applications that require authentication and applications that do not require authentication, it is possible to achieve both a high level of security and high operability.

[0152] <Authentication method example 2> An example of an authentication method different from that shown in Fig. 11 will be described below. Fig. 14 shows a flowchart relating to the operation of the authentication method.

[0153] First, the process starts. At this time, the system of the electronic device 420 is locked, and the functions that the user can execute are limited (including a logged-out state and a logged-off state).

[0154] In step S12, a user operation is detected on the electronic device 420. As the above description can be referred to for step S12, a detailed description thereof will be omitted.

[0155] Next, in step S41, first authentication information is acquired using the sensor unit 403. As the first authentication information, data relating to the user's health, such as vein shape, pulse wave, blood glucose level, cholesterol concentration in the blood, triglyceride concentration, etc., can be used. The first authentication information is output from the sensor unit 403 to the control unit 401.

[0156] Next, in step S42, authentication unit 407 executes a first authentication process. Specifically, authentication unit 407 compares the first authentication information (health-related data) output from sensor unit 403 with the user's health-related data that has been registered in advance and stored in storage unit 404, and determines whether they match. If it is determined that authentication has been successful, that is, that the first authentication information and the user's data match, the process proceeds to step S13 ("Yes" in step S42). If it is determined that authentication has not been successful, that is, that the first authentication information and the user's data do not match, the process ends ("No" in step S42).

[0157] Subsequently, in step S13, the display element 405 included in the pixel portion 422 is turned on. Since the description of <Example 1 of authentication method> can be referred to for step S13, detailed description thereof will be omitted.

[0158] Subsequently, in step S14, second authentication information is obtained using the light receiving element 406. For step S14, the description in <Example of authentication method 1> can be referred to, and therefore a detailed description will be omitted.

[0159] Next, in step S15, the authentication unit 407 executes a second authentication process. Specifically, the authentication unit 407 compares the second authentication information output from the pixel unit 422 with the user's fingerprint information that has been registered in advance and stored in the storage unit 404, and determines whether or not they match. For step S15, the description in <Example 1 of Authentication Method> can be referred to, and therefore a detailed description thereof will be omitted.

[0160] For the subsequent steps S16 to S18, the description in <Example of Authentication Method 1> can be referred to, and therefore detailed description will be omitted.

[0161] The electronic device 420 of one embodiment of the present invention can be a display device with a higher security level by performing multi-stage authentication including first and second authentications. Although FIG. 14 illustrates a configuration in which the second authentication is performed after the first authentication, one embodiment of the present invention is not limited to this. The first authentication may be performed after the second authentication. In this case, for example, steps S41 and S42 related to the first authentication may be performed after steps S13 to S15 related to the second authentication. Furthermore, steps S41 and S42 related to the first authentication and steps S13 to S14 related to the second authentication may be performed in parallel.

[0162] This concludes the description of the flowchart shown in FIG.

[0163] <Authentication method example 3> An example of an authentication method different from that shown in Fig. 11 will be described below. Fig. 15 shows a flowchart relating to the operation of the authentication method.

[0164] First, the process starts. At this time, the system of the electronic device 420 is locked, and the functions that the user can execute are limited (including a logged-out state and a logged-off state).

[0165] In step S11, it is detected that the electronic device 420 is worn by the user. As the above description can be referred to for step S11, detailed description thereof will be omitted.

[0166] Next, in step S12, it is detected whether or not a user has operated the electronic device 420. As the above description can be referred to for step S12, a detailed description thereof will be omitted.

[0167] Next, in step S21, a position image for authentication is displayed in first area 425. The position image includes an image indicating the position to be touched by the user, an image informing the user of the touch position, text information urging the user to touch, and the like.

[0168] Specifically, the control unit 401 generates image data including a position image and outputs the image data to the pixel unit 422, whereby an image based on the image data is displayed on the pixel unit 422. The area where the position image is displayed can be the first area 425 where the sensor unit 403 is used to acquire the second information.

[0169] 16 shows an example in which image 426 has an illustration of a fingerprint and the word "Touch" as text information to encourage the user to touch. By adding text information in addition to an illustration, the location can be shown to the user in an easy-to-understand manner.

[0170] As image 426, it is possible to display not only the touch position but also an image or text information specifying the finger to touch. For example, text information such as "Please touch with your index finger" can be displayed, and authentication can be performed using the fingerprint information of the index finger. As with the touch position, the specified finger may be randomly changed each time processing is performed.

[0171] Next, in step S13, the display elements 405 in the first region 425 are turned on. The user can perform the first authentication by touching the first region 425. As the above description can be referred to for step S13, a detailed description thereof will be omitted. Note that in step S13, all the display elements 405 in the pixel portion 422 may be turned on.

[0172] For the subsequent steps S14 to S18, the description in <Example of Authentication Method 1> can be referred to, and therefore detailed description will be omitted.

[0173] This concludes the description of the flowchart shown in FIG.

[0174] <Authentication method example 4> An example of an authentication method different from that shown in Fig. 11 will be described below. Fig. 17 shows a flowchart relating to the operation of the authentication method.

[0175] First, the process starts. At this time, the system of the electronic device 420 is locked, and the functions that the user can execute are limited (including a logged-out state and a logged-off state).

[0176] For steps S11 to S14, the description relating to FIG. 11 can be referred to, and therefore detailed description thereof will be omitted.

[0177] Next, in step S15a, authentication unit 407 executes authentication processing. Specifically, authentication unit 407 compares the authentication information output from pixel unit 422 with multiple pieces of user fingerprint information that have been registered in advance and stored in storage unit 404, and determines whether any of the fingerprint information matches the authentication information. If it is determined that the authentication information output from pixel unit 422 matches the fingerprint information of user's finger A, the process proceeds to step S16a ("Matches finger A" in step S15a). If it is determined that the authentication information output from pixel unit 422 matches the fingerprint information of user's finger B, the process proceeds to step S16b ("Matches finger B" in step S15a). If authentication is not successful, that is, if it is determined that the authentication information output from pixel unit 422 does not match any of the user's fingerprint information, the process ends ("No match" in step S15a).

[0178] In step S16a, the control unit 401 executes process A according to the fingerprint information of finger A. In step S16b, the control unit 401 executes process A according to the fingerprint information of finger B. Any operation can be assigned to each of process A and process B. For example, launching any application, operating an application, or closing an application can be assigned to each of process A and process B. For example, launching a video playback application can be assigned to process A, and launching an electronic payment application can be assigned to process B. For example, the operation of playing any video in a video playback application can be assigned to process A, and the operation of logging in to an electronic payment application can be assigned to process B. It is preferable that process A and process B can be arbitrarily set by the user.

[0179] For example, as shown in Figures 13A and 13B, by obtaining authentication information 451a using the index finger (finger 463a) of the right hand, any video can be played in a video playback application, and as shown in Figures 18A and 18B, by obtaining authentication information 451b using the thumb (finger 463b) of the right hand, it is possible to log in to an electronic payment application.

[0180] Note that finger A and finger B each represent any finger having fingerprint information stored in advance in storage unit 404, and refer to, for example, any of the thumb, index finger, middle finger, ring finger, and little finger. While Fig. 17 shows an example in which fingerprint information of two fingers, finger A and finger B, is used, one embodiment of the present invention is not limited to this. Fingerprint information of three or more fingers may be used, and processing appropriate for each finger may be executed.

[0181] By varying the post-authentication process depending on the finger used for authentication, it is possible to achieve both a high level of security and high operability.

[0182] For the subsequent steps S17 and S18, the description relating to FIG. 11 can be referred to, and therefore detailed description thereof will be omitted.

[0183] This concludes the description of the flowchart shown in FIG.

[0184] <Electronic device configuration example 2> A configuration example different from the above-described electronic device 10 will be described. A block diagram of an electronic device 10A according to one embodiment of the present invention is shown in FIG. 19. The electronic device 10A differs from the above-described electronic device 10 mainly in that a pixel portion 402 includes a touch sensor 408.

[0185] The touch sensor 408 has a function of detecting that the pixel portion 402 has been touched, and a function of obtaining touched position information and outputting it to the control unit 401 .

[0186] The control unit 401 has a function of processing position information of a detected object input from the touch sensor 408. Furthermore, when the system of the electronic device 10A is in a locked state and the touch sensor 408 detects a touch operation and outputs information on the touched position, the control unit 401 has a function of generating image data and outputting the image data to the pixel unit 402 so as to light up the display element 405 at the touched position for the pixel unit 402. Furthermore, the control unit 401 has a function of requesting the pixel unit 402 to capture an image of a fingerprint with the display element 405 turned on.

[0187] When the system of electronic device 10A is in a locked state, control unit 401 may have a function of generating image data including an image (position image) indicating a position to be touched by a user in pixel unit 402, and outputting the image data to pixel unit 402. Furthermore, pixel unit 402 has a function of acquiring position information of a detectable object such as a finger using touch sensor 408, and outputting the position information to control unit 401.

[0188] It is preferable that the pixel portion 402 can acquire fingerprint information of a finger that touches anywhere on the pixel portion 402. That is, it is preferable that the range on the pixel portion 402 where the touch sensor 408 functions and the range where fingerprint information can be acquired match or approximately match.

[0189] <Authentication method example 5> An example of an authentication method for the electronic device 10A described above will be described. A flowchart relating to the operation of the authentication method using the electronic device 10A is shown in FIG. 20. An electronic device 420A to which the electronic device 10A is applied is shown in FIG. 21A. The electronic device 420A has a housing 431 and a pixel unit 422. The electronic device 420A has a control unit 401, a sensor unit 403, and a memory unit 404 within the housing 431. The pixel unit 402 described above can be applied to the pixel unit 422.

[0190] First, processing starts. At this time, the system of electronic device 420A is locked. In step S11, it is detected that electronic device 420 is attached to a user. As the above description can be referred to for step S11, detailed description thereof will be omitted.

[0191] In step S31, it is detected whether or not the pixel unit 422 has been touched. Touch detection is performed by the touch sensor 408. If a touch is detected, the process proceeds to step S32 ("Yes" in step S31). Step S31 is repeatedly performed until a touch is detected ("No" in step S31). If no touch is detected for a certain period of time, or if a different position is touched, the process ends.

[0192] In step S32, position information of the touch position is acquired. The position information is output from the touch sensor 408 to the control unit 401.

[0193] In step S33, the display elements 405 located at and near the touch position are turned on based on the position information. The touch position and its vicinity can be defined as a first region 425. At this time, the control unit 401 generates image data in which the first region 425 is bright (high gradation value) and the other parts are dark (low gradation value), and outputs the image data to the pixel unit 422, whereby an image based on the image data is displayed on the pixel unit 422.

[0194] In step S33, the first area 425 may be brightly displayed (lit) and the other areas may be turned off. Note that an arbitrary image may be displayed in an area other than the first area 425.

[0195] The area (first area 425) in which the display element 405 is illuminated is preferably an area hidden by the finger. When touching the screen with a finger, the contact surface of the finger is located inside the outline of the finger as seen from the user, and the projected area of ​​the finger on the screen is larger than the contact area of ​​the finger. Therefore, when the contact area is 100%, the illuminated area can be 50% to 150%, preferably 70% to 130%, and more preferably 80% to 120%. If the illuminated area is smaller than 50%, the fingerprint information obtained by imaging may be insufficient, which may reduce the accuracy of authentication. On the other hand, if the illuminated area exceeds 150%, the light source may be directly visible to the user.

[0196] The illuminated area may be a circle with a radius r centered on the touch position, and the value of the radius r may be set in advance. Since the size and shape of fingers vary depending on the age, gender, physique, etc. of the user, the radius r of the circle that defines the illuminated area may be set by the user.

[0197] FIG. 21A shows a state in which the area where touch is detected by touch sensor 408 and its vicinity are designated as first area 425, and the display element 405 in first area 425 is illuminated. FIG. 21B shows finger 463 in FIG. 21A as a transparent image, with only the outline indicated by a dashed line, and the first area 425 hatched. As shown in FIGS. 21A and 21B, the brightly illuminated first area 425 is hidden by finger 463 and is difficult for the user to see. Therefore, fingerprint authentication can be performed without causing stress to the user. Furthermore, electronic device 420A can perform fingerprint authentication at any position within pixel unit 422.

[0198] For the subsequent steps S14 to S18, the description relating to FIG. 11 can be referred to, and therefore detailed description thereof will be omitted.

[0199] This concludes the description of the flowchart shown in FIG.

[0200] The above is a description of an example of the configuration of an electronic device and an example of an authentication method according to one aspect of the present invention.

[0201] Note that the authentication method, processing method, operation method, operating 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, operating 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 a computing device, etc., included in the control unit 401 of the electronic device 420. In other words, a program for causing hardware to execute the authentication method, operating method, etc., exemplified above, and a non-transitory storage medium storing the program are one embodiment of the present invention.

[0202] 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.

[0203] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0204] (Embodiment 2) In this embodiment, a pixel portion of an electronic device according to one embodiment of the present invention will be described.

[0205] The pixel portion of the electronic device of one embodiment of the present invention may be any of a top emission type that emits light in a direction opposite to a substrate on which a light-emitting element is formed, a bottom emission type that emits light toward a substrate on which a light-emitting element is formed, and a dual emission type that emits light to both sides.

[0206] In this embodiment, a top emission type will be described as an example.

[0207] In this specification, unless otherwise specified, even when describing a configuration having a plurality of elements (light-emitting elements, light-emitting layers, etc.), when describing matters common to each element, the alphabet will be omitted. For example, when describing matters common to light-emitting layer 283R and light-emitting layer 283G, etc., they may be referred to as light-emitting layer 283.

[0208] <Configuration example 1> The pixel section 280A shown in FIG. 22A has a light receiving element 270PD, a light emitting element 270R that emits red (R) light, a light emitting element 270G that emits green (G) light, and a light emitting element 270B that emits blue (B) light.

[0209] Each light-emitting element has a pixel electrode 271, a hole injection layer 281, a hole transport layer 282, a light-emitting layer 283, an electron transport layer 284, an electron injection layer 285, and a common electrode 275 stacked in this order. Light-emitting element 270R has a light-emitting layer 283R, light-emitting element 270G has a light-emitting layer 283G, and light-emitting element 270B has a light-emitting layer 283B. Light-emitting layer 283R contains a light-emitting material that emits red light, light-emitting layer 283G contains a light-emitting material that emits green light, and light-emitting layer 283B contains a light-emitting material that emits blue light.

[0210] The light emitting element is an electroluminescent element that emits light toward the common electrode 275 when a voltage is applied between the pixel electrode 271 and the common electrode 275 .

[0211] The light receiving element 270PD has a pixel electrode 271, a hole injection layer 281, a hole transport layer 282, an active layer 273, an electron transport layer 284, an electron injection layer 285, and a common electrode 275 stacked in this order.

[0212] The light receiving element 270PD is a photoelectric conversion element that receives light incident from outside the pixel unit 280A and converts it into an electrical signal.

[0213] In this embodiment, in both the light-emitting element and the light-receiving element, the pixel electrode 271 functions as an anode, and the common electrode 275 functions as a cathode. In other words, by applying a reverse bias between the pixel electrode 271 and the common electrode 275 and driving the light-receiving element, the light incident on the light-receiving element can be detected, an electric charge can be generated, and the electric charge can be extracted as a current.

[0214] In the pixel portion of the electronic device of this embodiment, an organic compound is used for the active layer 273 of the light-receiving element 270PD. The layers of the light-receiving element 270PD other than the active layer 273 can be configured in common with the light-emitting element. Therefore, by simply adding a step of forming the active layer 273 to the manufacturing process of the light-emitting element, the light-receiving element 270PD can be formed in parallel with the formation of the light-emitting element. Furthermore, the light-emitting element and the light-receiving element 270PD can be formed on the same substrate. Therefore, the light-receiving element 270PD can be built into the pixel portion without significantly increasing the number of manufacturing steps.

[0215] In the pixel section 280A, an example is shown in which the light receiving element 270PD and the light emitting element have a common configuration, except that the active layer 273 of the light receiving element 270PD and the light emitting layer 283 of the light emitting element are fabricated separately. However, the configuration of the light receiving element 270PD and the light emitting element is not limited to this. The light receiving element 270PD and the light emitting element may have layers that are fabricated separately from each other, in addition to the active layer 273 and the light emitting layer 283. It is preferable that the light receiving element 270PD and the light emitting element have one or more layers that are used in common (common layers). This allows the light receiving element 270PD to be incorporated into the pixel section without significantly increasing the number of fabrication steps.

[0216] A conductive film that transmits visible light is used for the electrode from which light is extracted, between the pixel electrode 271 and the common electrode 275. It is preferable to use a conductive film that reflects visible light for the electrode from which light is not extracted.

[0217] A micro-optical resonator (microcavity) structure is preferably applied to the light-emitting element included in the pixel portion of the electronic device of this embodiment. Therefore, one of a pair of electrodes included in the light-emitting element is preferably an electrode that is transparent and reflective to visible light (semi-transmissive / semi-reflective electrode), and the other is preferably an electrode that is reflective to visible light (reflective electrode). When the light-emitting element has a microcavity structure, light emitted from the light-emitting layer can be resonated between both electrodes, thereby intensifying the light emitted from the light-emitting element.

[0218] The semi-transmitting and semi-reflective electrode may have a laminated structure of a reflective electrode and an electrode that is transparent to visible light (also called a transparent electrode).

[0219] The light transmittance of the transparent electrode is 40% or more. For example, it is preferable to use an electrode with a visible light (light with a wavelength of 400 nm or more and less than 750 nm) transmittance of 40% or more for the light emitting element. The visible light reflectance of the semi-transmissive / semi-reflective electrode is 10% or more and 95% or less, preferably 30% or more and 80% or less. The visible light reflectance of the reflective electrode is 40% or more and 100% or less, preferably 70% or more and 100% or less. In addition, the resistivity of these electrodes is 1×10-2 When the light-emitting element emits near-infrared light (light with a wavelength of 750 nm or more and 1300 nm or less), the transmittance or reflectance of these electrodes for near-infrared light preferably satisfies the above-mentioned numerical range, similar to the transmittance or reflectance for visible light.

[0220] The light-emitting element has at least the light-emitting layer 283. The light-emitting element may further have, in addition to the light-emitting layer 283, a layer containing a substance having a high hole-injecting property, a substance having a high hole-transporting property, a hole-blocking material, a substance having a high electron-transporting property, a substance having a high electron-injecting property, a bipolar substance (a substance having a high electron-transporting property and a high hole-transporting property), or the like.

[0221] For example, the light-emitting element and the light-receiving element may have one or more layers of the hole injection layer, hole transport layer, electron transport layer, and electron injection layer in common, or the light-emitting element and the light-receiving element may have one or more layers of the hole injection layer, hole transport layer, electron transport layer, and electron injection layer formed differently from each other.

[0222] 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. As the material with high hole injection properties, a composite material containing a hole transport material (e.g., an aromatic amine compound) and an acceptor material (electron acceptor material) can be used.

[0223] In a light-emitting element, the hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light-emitting layer. In a light-receiving element, the hole transport layer is a layer that transports holes generated in the active layer based on incident light to the anode. The hole transport layer is a layer that contains a hole transport material. The hole transport material is 10 -6 cm 2 A material having a hole mobility of 1 / Vs or more is preferred. Note that other materials can also be used as long as they have a higher hole transporting property than electron transporting property. The hole transporting material is preferably 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).

[0224] In a light-emitting element, the electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light-emitting layer. In a light-receiving element, the electron transport layer is a layer that transports electrons generated in the active layer based on incident light to the cathode. The electron transport layer is a layer that contains an electron transporting material. The electron transporting material has a density 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 the electron-transporting material 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 π-electron-deficient heteroaromatic compounds including nitrogen-containing heteroaromatic compounds.

[0225] 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. The material with high electron injection properties can be an alkali metal, an alkaline earth metal, or a compound thereof. The material with high electron injection properties can also be a composite material containing an electron transport material and a donor material (electron donor material).

[0226] The light-emitting layer 283 is a layer containing a light-emitting substance. The light-emitting layer 283 can have one or more types of 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.

[0227] Examples of light-emitting materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0228] 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.

[0229] 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.

[0230] The light-emitting layer 283 may contain one or more organic compounds (host materials, assist materials, etc.) in addition to a light-emitting substance (guest material). One or both of a hole-transporting material and an electron-transporting material may be used as the one or more organic compounds. Furthermore, a bipolar material or a TADF material may be used as the one or more organic compounds.

[0231] The light-emitting layer 283 preferably includes, for example, a phosphorescent material and a hole-transporting material and an electron-transporting material that are a combination that easily forms an exciplex. This structure allows efficient emission using Exciplex-Triplet Energy Transfer (ExTET), which is energy transfer from an exciplex to a light-emitting substance (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 substance, the energy transfer becomes smooth and light emission can be achieved efficiently. This structure simultaneously enables high efficiency, low-voltage operation, and long life of the light-emitting element.

[0232] In a combination of materials that form an exciplex, the HOMO level (highest occupied molecular orbital level) of the hole-transporting material is preferably equal to or higher than the HOMO level of the electron-transporting material. The LUMO level (lowest unoccupied molecular orbital level) of the hole-transporting material is preferably equal to or higher than the LUMO level of the electron-transporting material. The LUMO and HOMO levels of the materials can be derived from the electrochemical properties (reduction potential and oxidation potential) of the materials measured by cyclic voltammetry (CV).

[0233] The formation of exciplexes can be confirmed, for example, by comparing the emission spectra of the hole-transporting material, the electron-transporting material, and the mixed film of these materials and observing the phenomenon that the emission spectrum of the mixed film is shifted to longer wavelengths than the emission spectra of each material (or has a new peak at longer wavelengths). Alternatively, it can be confirmed by comparing the transient photoluminescence (PL) of the hole-transporting material, the transient PL of the electron-transporting material, and the mixed film of these materials and observing differences in transient response, such as the transient PL lifetime of the mixed film having a longer-lived component or a larger proportion of delayed components than the transient PL lifetimes of the individual materials. The above-mentioned transient PL can also be interpreted as transient electroluminescence (EL). In other words, the formation of exciplexes can also be confirmed by comparing the transient EL of the hole-transporting material, the transient EL of the electron-transporting material, and the mixed film of these materials and observing differences in transient response.

[0234] The active layer 273 includes a semiconductor. Examples of the semiconductor include an inorganic semiconductor such as silicon and an organic semiconductor including an organic compound. In this embodiment, an example in which an organic semiconductor is used as the semiconductor included in the active layer 273 is shown. By using an organic semiconductor, the light-emitting layer 283 and the active layer 273 can be formed by the same method (for example, vacuum deposition), which is preferable because it allows the use of a common manufacturing device.

[0235] The active layer 273 is made of an n-type semiconductor material such as fullerene (e.g., C 60 , C 70Examples of electron-accepting organic semiconductor materials include fullerene derivatives and other fullerenes. Fullerenes have a soccer ball-like shape, which 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 the π-electron conjugation (resonance) spreads on a plane, as in benzene, the electron-donating (donor) properties increase, but fullerenes have a spherical shape, so they have high electron-accepting properties despite the large spread of π-electrons. High electron-accepting properties allow charge separation to occur 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, especially C 70 is C 60 It is preferred because it has a larger π-electron conjugated system and a wide absorption band in the long wavelength region compared to the above.

[0236] 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.

[0237] Examples of p-type semiconductor materials that the active layer 273 has include electron-donating organic semiconductor materials such as copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), and quinacridone.

[0238] Examples of p-type semiconductor materials include carbazole derivatives, thiophene derivatives, furan derivatives, compounds having an aromatic amine skeleton, etc. Further 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.

[0239] 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.

[0240] 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.

[0241] For example, the active layer 273 is preferably formed by co-evaporating an n-type semiconductor and a p-type semiconductor, or alternatively, the active layer 273 may be formed by laminating an n-type semiconductor and a p-type semiconductor.

[0242] The light-emitting element and 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-emitting element and the light-receiving 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.

[0243] The pixel section 280B shown in FIG. 22B differs from the pixel section 280A in that the light receiving element 270PD and the light emitting element 270R have the same configuration.

[0244] The light receiving element 270PD and the light emitting element 270R have the active layer 273 and the light emitting layer 283R in common.

[0245] Here, it is preferable that light receiving element 270PD has a common configuration with a light emitting element that emits light of a longer wavelength than the light to be detected. For example, light receiving element 270PD configured to detect blue light can have the same configuration as one or both of light emitting element 270R and light emitting element 270G. For example, light receiving element 270PD configured to detect green light can have the same configuration as light emitting element 270R.

[0246] By using a common configuration for the light-receiving element 270PD and the light-emitting element 270R, the number of film-forming steps and the number of masks can be reduced compared to a configuration in which the light-receiving element 270PD and the light-emitting element 270R have separate layers, thereby reducing the number of steps and costs required to fabricate the pixel portion.

[0247] By using a common configuration for the light receiving element 270PD and the light emitting element 270R, the margin for misalignment can be narrowed compared to a configuration in which the light receiving element 270PD and the light emitting element 270R have separate layers. This allows for an increased aperture ratio of the pixel, and therefore an increased light extraction efficiency of the pixel portion. This also allows for an extended life of the light emitting element. Furthermore, a high-brightness pixel portion can be achieved. Furthermore, a high-resolution pixel portion can be achieved.

[0248] Light-emitting layer 283R includes a light-emitting material that emits red light. Active layer 273 includes an organic compound that absorbs light with a wavelength shorter than red (for example, one or both of green light and blue light). Active layer 273 preferably includes an organic compound that does not easily absorb red light and absorbs light with a wavelength shorter than red. This allows red light to be extracted efficiently from light-emitting element 270R, and light-receiving element 270PD to detect light with a wavelength shorter than red with high accuracy.

[0249] In the pixel section 280B, an example is shown in which the light emitting element 270R and the light receiving element 270PD have the same configuration, but the light emitting element 270R and the light receiving element 270PD may have optical adjustment layers of different thicknesses.

[0250] 23A and 23B includes a light receiving / emitting element 270SR that emits red (R) light and has a light receiving function, a light emitting element 270G, and a light emitting element 270B. The configuration of the light emitting element 270G and the light emitting element 270B can be based on the configuration of the pixel unit 280A described above.

[0251] The light emitting / receiving element 270SR has, stacked in this order, a pixel electrode 271, a hole injection layer 281, a hole transport layer 282, an active layer 273, a light emitting layer 283R, an electron transport layer 284, an electron injection layer 285, and a common electrode 275. The light emitting / receiving element 270SR has the same configuration as the light emitting element 270R and the light receiving element 270PD exemplified in the pixel section 280B.

[0252] 23A shows a case where the light emitting / receiving element 270SR functions as a light emitting element. In FIG. 23A, an example is shown in which the light emitting element 270B emits blue light, the light emitting element 270G emits green light, and the light emitting / receiving element 270SR emits red light.

[0253] Fig. 23B shows a case where the light receiving / emitting element 270SR functions as a light receiving element. Fig. 23B shows an example where the light receiving / emitting element 270SR receives blue light emitted by the light emitting element 270B and green light emitted by the light emitting element 270G.

[0254] The light emitting element 270B, the light emitting element 270G, and the light emitting / receiving element 270SR each have a pixel electrode 271 and a common electrode 275. In the present embodiment, a case will be described as an example in which the pixel electrode 271 functions as an anode and the common electrode 275 functions as a cathode. The light emitting / receiving element 270SR is driven by applying a reverse bias between the pixel electrode 271 and the common electrode 275, whereby it can detect light incident on the light emitting / receiving element 270SR, generate electric charges, and extract the charges as a current.

[0255] The light emitting / receiving element 270SR can be said to have a configuration in which the active layer 273 is added to the light emitting element. In other words, the light emitting / receiving element 270SR can be formed in parallel with the formation of the light emitting element by simply adding a process for forming the active layer 273 to the manufacturing process of the light emitting element. Furthermore, the light emitting element and the light emitting / receiving element can be formed on the same substrate. Therefore, it is possible to impart one or both of an imaging function and a sensing function to the pixel portion without significantly increasing the manufacturing process.

[0256] There are no limitations on the stacking order of the light-emitting layer 283R and the active layer 273. Figures 23A and 23B show an example in which the active layer 273 is provided on the hole transport layer 282, and the light-emitting layer 283R is provided on the active layer 273. The stacking order of the light-emitting layer 283R and the active layer 273 may be reversed.

[0257] The light emitting / receiving element may not have at least one layer selected from the hole injection layer 281, the hole transport layer 282, the electron transport layer 284, and the electron injection layer 285. The light emitting / receiving element may also have other functional layers such as a hole blocking layer and an electron blocking layer.

[0258] In the light emitting / receiving element, a conductive film that transmits visible light is used for the electrode on the light extraction side, and a conductive film that reflects visible light is preferably used for the electrode on the non-light extraction side.

[0259] The functions and materials of the layers constituting the light emitting / receiving element are similar to those of the layers constituting the light emitting element and the light receiving element, and therefore detailed description thereof will be omitted.

[0260] 23C to 23G show examples of the stacked structure of the light emitting and receiving element.

[0261] The light emitting / receiving element shown in FIG. 23C has a first electrode 277, a hole injection layer 281, a hole transport layer 282, a light emitting layer 283R, an active layer 273, an electron transport layer 284, an electron injection layer 285, and a second electrode 278.

[0262] FIG. 23C shows an example in which a light-emitting layer 283R is provided on a hole-transporting layer 282, and an active layer 273 is laminated on the light-emitting layer 283R.

[0263] As shown in FIGS. 23A to 23C, the active layer 273 and the light-emitting layer 283R may be in contact with each other.

[0264] A buffer layer is preferably provided between the active layer 273 and the light-emitting layer 283R. In this case, the buffer layer preferably has hole transport properties and electron transport properties. For example, a bipolar substance is preferably used for the buffer layer. Alternatively, at least one layer selected from a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole blocking layer, and an electron blocking layer can be used as the buffer layer. FIG. 23D shows an example in which a hole transport layer 282 is used as the buffer layer.

[0265] By providing a buffer layer between the active layer 273 and the light-emitting layer 283R, it is possible to suppress the transfer of excitation energy from the light-emitting layer 283R to the active layer 273. In addition, the buffer layer can also be used to adjust the optical path length (cavity length) of the microcavity structure. Therefore, a light-emitting / receiving element having a buffer layer between the active layer 273 and the light-emitting layer 283R can obtain high light-emitting efficiency.

[0266] FIG. 23E shows an example of a laminated structure in which a hole transport layer 282-1, an active layer 273, a hole transport layer 282-2, and an emitting layer 283R are laminated in this order on a hole injection layer 281. The hole transport layer 282-2 functions as a buffer layer. The hole transport layer 282-1 and the hole transport layer 281-2 may contain the same material or different materials. Alternatively, a layer that can be used as the buffer layer described above may be used instead of the hole transport layer 281-2. Alternatively, the positions of the active layer 273 and the emitting layer 283R may be interchanged.

[0267] 23F differs from the light emitting / receiving element shown in Fig. 23A in that it does not have the hole transport layer 282. In this way, the light emitting / receiving element may not have at least one layer among the hole injection layer 281, the hole transport layer 282, the electron transport layer 284, and the electron injection layer 285. In addition, the light emitting / receiving element may have other functional layers such as a hole blocking layer or an electron blocking layer.

[0268] The light emitting / receiving device shown in FIG. 23G differs from the light emitting / receiving device shown in FIG. 23A in that it does not have the active layer 273 and the light emitting layer 283R, but has a layer 289 that serves as both the light emitting layer and the active layer.

[0269] Layer 289, which serves as both a light-emitting layer and an active layer, can be, for example, a layer containing three materials: an n-type semiconductor that can be used for active layer 273, a p-type semiconductor that can be used for active layer 273, and a light-emitting substance that can be used for light-emitting layer 283R.

[0270] It is preferable that the lowest energy absorption band in the absorption spectrum of the mixed material of n-type and p-type semiconductors does not overlap with the maximum peak in the emission spectrum (PL spectrum) of the luminescent substance, and it is more preferable that they are sufficiently separated from each other.

[0271] <Configuration example 2> A detailed structure of a display device that can be used as a pixel portion of an electronic device according to one embodiment of the present invention will be described below. In particular, an example of a display device including a light-receiving element and a light-emitting element will be described.

[0272] [Configuration Example 2-1] 24A shows a cross-sectional view of the display device 300A. The display device 300A includes a substrate 351, a substrate 352, a light receiving element 310, and a light emitting element 390.

[0273] The light-emitting element 390 has a pixel electrode 391, a buffer layer 312, a light-emitting layer 393, a buffer layer 314, and a common electrode 315 stacked in this order. The buffer layer 312 can have one or both of a hole injection layer and a hole transport layer. The light-emitting layer 393 contains an organic compound. The buffer layer 314 can have one or both of an electron injection layer and an electron transport layer. The light-emitting element 390 has a function of emitting visible light 321. Note that the display device 300A may further have a light-emitting element that has a function of emitting infrared light.

[0274] The light receiving element 310 has a pixel electrode 311, a buffer layer 312, an active layer 313, a buffer layer 314, and a common electrode 315 stacked in this order. The active layer 313 contains an organic compound. The light receiving element 310 has a function of detecting visible light. The light receiving element 310 may also have a function of detecting infrared light.

[0275] The buffer layer 312, the buffer layer 314, and the common electrode 315 are layers common to the light-emitting element 390 and the light-receiving element 310, and are provided across these elements. The buffer layer 312, the buffer layer 314, and the common electrode 315 have portions that overlap with the active layer 313 and the pixel electrode 311, portions that overlap with the light-emitting layer 393 and the pixel electrode 391, and portions that do not overlap with either.

[0276] In the present embodiment, the pixel electrode functions as an anode and the common electrode 315 functions as a cathode in both the light-emitting element 390 and the light-receiving element 310. In other words, by driving the light-receiving element 310 by applying a reverse bias between the pixel electrode 311 and the common electrode 315, the display device 300A can detect light incident on the light-receiving element 310, generate charges, and extract them as a current.

[0277] The pixel electrode 311, the pixel electrode 391, the buffer layer 312, the active layer 313, the buffer layer 314, the light-emitting layer 393, and the common electrode 315 may each have a single-layer structure or a multilayer structure.

[0278] The pixel electrode 311 and the pixel electrode 391 are each located on an insulating layer 414. Each pixel electrode can be formed using the same material and in the same process. Ends of the pixel electrode 311 and the pixel electrode 391 are covered with a partition wall 416. Two adjacent pixel electrodes are electrically insulated (or electrically separated) from each other by the partition wall 416.

[0279] An organic insulating film is suitable for the partition 416. 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. The partition 416 is a layer that transmits visible light. Instead of the partition 416, a partition that blocks visible light may be provided.

[0280] The common electrode 315 is a layer that is used in common by the light receiving element 310 and the light emitting element 390 .

[0281] The materials and thicknesses of the pair of electrodes of the light-receiving element 310 and the pair of electrodes of the light-emitting element 390 can be made the same, which leads to reduction in manufacturing cost of the display device and simplification of the manufacturing process.

[0282] The display device 300A includes a light receiving element 310, a light emitting element 390, a transistor 331, a transistor 332, and the like between a pair of substrates (substrate 351 and substrate 352).

[0283] In the light-receiving element 310, the buffer layer 312, active layer 313, and buffer layer 314 located between the pixel electrode 311 and the common electrode 315 can also be called organic layers (layers containing an organic compound). The pixel electrode 311 preferably has a function of reflecting visible light. The common electrode 315 has a function of transmitting visible light. Note that, when the light-receiving element 310 is configured to detect infrared light, the common electrode 315 has a function of transmitting infrared light. Furthermore, the pixel electrode 311 preferably has a function of reflecting infrared light.

[0284] The light receiving element 310 has a function of detecting light. Specifically, the light receiving element 310 is a photoelectric conversion element that receives light 322 incident from outside the display device 300A and converts the received light into an electrical signal. The light 322 can also be said to be light emitted by the light emitting element 390 and reflected by an object. The light 322 may also be incident on the light receiving element 310 via a lens or the like provided in the display device 300A.

[0285] In the light-emitting element 390, the buffer layer 312, the light-emitting layer 393, and the buffer layer 314 located between the pixel electrode 391 and the common electrode 315 can be collectively referred to as an EL layer. The EL layer has at least the light-emitting layer 393. As described above, the pixel electrode 391 preferably has a function of reflecting visible light. Furthermore, the common electrode 315 has a function of transmitting visible light. Note that, when the display device 300A has a configuration including a light-emitting element that emits infrared light, the common electrode 315 has a function of transmitting infrared light. Furthermore, the pixel electrode 391 preferably has a function of reflecting infrared light.

[0286] It is preferable that a micro-optical resonator (microcavity) structure is applied to the light-emitting element included in the display device of this embodiment. The light-emitting element 390 may have an optical adjustment layer between the pixel electrode 391 and the common electrode 315. By applying the micro-resonator structure, it is possible to intensify and extract light of a specific color from each light-emitting element.

[0287] The light-emitting element 390 has a function of emitting visible light. Specifically, the light-emitting element 390 is an electroluminescent element that emits light (here, visible light 321) toward the substrate 352 by applying a voltage between the pixel electrode 391 and the common electrode 315.

[0288] The pixel electrode 311 of the light-receiving element 310 is electrically connected to the source or drain of the transistor 331 through an opening provided in the insulating layer 414. The pixel electrode 391 of the light-emitting element 390 is electrically connected to the source or drain of the transistor 332 through an opening provided in the insulating layer 414.

[0289] The transistor 331 and the transistor 332 are adjacent to each other on the same layer (substrate 351 in FIG. 24A).

[0290] At least a part of the circuit electrically connected to the light receiving element 310 is preferably formed using the same material and in the same process as the circuit electrically connected to the light emitting element 390. This allows the display device to be thinner and the manufacturing process to be simplified compared to when the two circuits are formed separately.

[0291] Preferably, the light receiving element 310 and the light emitting element 390 are each covered with a protective layer 395. In Fig. 24A, the protective layer 395 is provided on and in contact with the common electrode 315. Providing the protective layer 395 can prevent impurities such as water from entering the light receiving element 310 and the light emitting element 390, thereby improving the reliability of the light receiving element 310 and the light emitting element 390. In addition, the protective layer 395 and the substrate 352 are bonded together by an adhesive layer 342.

[0292] A light-shielding layer 358 is provided on the surface of the substrate 352 facing the substrate 351. The light-shielding layer 358 has openings at positions overlapping the light-emitting element 390 and the light-receiving element 310.

[0293] Here, the light receiving element 310 detects light emitted by the light emitting element 390 and reflected by the object. However, there is a case where the light emitted by the light emitting element 390 is reflected within the display device 300A and is incident on the light receiving element 310 without passing through the object. The light blocking layer 358 can suppress the influence of such stray light (reflected light). For example, if the light blocking layer 358 is not provided, the light 323 emitted by the light emitting element 390 may be reflected by the substrate 352, and the reflected light 324 may be incident on the light receiving element 310. By providing the light blocking layer 358, it is possible to prevent the reflected light 324 from being incident on the light receiving element 310. This reduces noise and improves the sensitivity of the sensor using the light receiving element 310.

[0294] The light-shielding layer 358 can be made of a material that blocks light emitted from the light-emitting elements. The light-shielding layer 358 preferably absorbs visible light. For example, the light-shielding layer 358 can be made of a black matrix using a metal material or a resin material containing a pigment (such as carbon black) or a dye. The light-shielding layer 358 may have a laminated structure of red, green, and blue color filters.

[0295] [Configuration Example 2-2] The display device 300B shown in FIG. 24B differs from the display device 300A described above mainly in that it has a lens 349.

[0296] Lens 349 is provided on the substrate 351 side of substrate 352. Light 322 incident from the outside is incident on light receiving element 310 via lens 349. It is preferable that lens 349 and substrate 352 are made of a material that is highly transparent to visible light.

[0297] Light is incident on the light receiving element 310 via the lens 349, thereby narrowing the range of light incident on the light receiving element 310. This makes it possible to prevent the imaging ranges of the multiple light receiving elements 310 from overlapping, and to capture clear images with little blur.

[0298] The lens 349 can condense the incident light, thereby increasing the amount of light incident on the light receiving element 310. This increases the photoelectric conversion efficiency of the light receiving element 310.

[0299] [Configuration Example 2-3] A display device 300C shown in FIG. 24C differs from the display device 300A described above mainly in that the shape of the light-shielding layer 358 is different.

[0300] The light-shielding layer 358 is provided such that, in a plan view, the opening overlapping the light-receiving element 310 is located inside the light-receiving region of the light-receiving element 310. The smaller the diameter of the opening of the light-shielding layer 358 overlapping with the light-receiving element 310, the narrower the range of light incident on the light-receiving element 310 can be. This makes it possible to prevent the imaging ranges of the multiple light-receiving elements 310 from overlapping, allowing for the capture of clear images with little blur.

[0301] For example, the area of ​​the opening in the light-shielding layer 358 can be 80% or less, 70% or less, 60% or less, 50% or less, or 40% or less of the area of ​​the light-receiving region of the light-receiving element 310, and can be 1% or more, 5% or more, or 10% or more. The smaller the area of ​​the opening in the light-shielding layer 358, the clearer the image can be captured. On the other hand, if the area of ​​the opening is too small, the amount of light reaching the light-receiving element 310 may decrease, resulting in a decrease in light-receiving sensitivity. Therefore, it is preferable to set the area appropriately within the above-mentioned range. Note that the above-mentioned upper and lower limits can be combined arbitrarily. Furthermore, the light-receiving region of the light-receiving element 310 can be rephrased as the opening in the partition wall 416.

[0302] The center of the opening of the light-shielding layer 358 that overlaps with the light-receiving element 310 may be offset from the center of the light-receiving region of the light-receiving element 310 in a planar view. Furthermore, the opening of the light-shielding layer 358 may not overlap with the light-receiving region of the light-receiving element 310 in a planar view. This allows the light-receiving element 310 to receive only obliquely directed light that has passed through the opening of the light-shielding layer 358. This makes it possible to more effectively limit the range of light that enters the light-receiving element 310, thereby enabling a clear image to be captured.

[0303] [Configuration Example 2-4] The display device 300D shown in FIG. 25A differs from the display device 300A described above mainly in that the buffer layer 312 is not a common layer.

[0304] The light receiving element 310 has a pixel electrode 311, a buffer layer 312, an active layer 313, a buffer layer 314, and a common electrode 315. The light emitting element 390 has a pixel electrode 391, a buffer layer 392, a light emitting layer 393, a buffer layer 314, and a common electrode 315. The active layer 313, the buffer layer 312, the light emitting layer 393, and the buffer layer 392 each have an island-shaped top surface.

[0305] Buffer layer 312 and buffer layer 392 may comprise different materials or the same materials.

[0306] In this way, by forming separate buffer layers for the light-emitting element 390 and the light-receiving element 310, the degree of freedom in selecting materials for the buffer layers used for the light-emitting element 390 and the light-receiving element 310 is increased, making optimization easier. Furthermore, by using the buffer layer 314 and the common electrode 315 as a common layer, the manufacturing process is simplified and manufacturing costs can be reduced compared to when the light-emitting element 390 and the light-receiving element 310 are manufactured separately.

[0307] [Configuration Example 2-5] A display device 300E shown in FIG. 25B differs from the display device 300A described above mainly in that the buffer layer 314 is not a common layer.

[0308] The light-receiving element 310 has a pixel electrode 311, a buffer layer 312, an active layer 313, a buffer layer 314, and a common electrode 315. The light-emitting element 390 has a pixel electrode 391, a buffer layer 312, a light-emitting layer 393, a buffer layer 394, and a common electrode 315. The active layer 313, the buffer layer 314, the light-emitting layer 393, and the buffer layer 394 each have an island-shaped top surface.

[0309] Buffer layer 314 and buffer layer 394 may comprise different materials or the same materials.

[0310] In this way, by forming separate buffer layers for the light-emitting element 390 and the light-receiving element 310, the degree of freedom in selecting the materials for the buffer layers used for the light-emitting element 390 and the light-receiving element 310 is increased, making optimization easier. Furthermore, by using the buffer layer 312 and the common electrode 315 as a common layer, the manufacturing process is simplified and manufacturing costs can be reduced compared to when the light-emitting element 390 and the light-receiving element 310 are manufactured separately.

[0311] [Configuration Example 2-6] A display device 300F shown in FIG. 25C differs from the display device 300A described above mainly in that the buffer layer 312 and the buffer layer 314 are not a common layer.

[0312] The light-receiving element 310 has a pixel electrode 311, a buffer layer 312, an active layer 313, a buffer layer 314, and a common electrode 315. The light-emitting element 390 has a pixel electrode 391, a buffer layer 392, a light-emitting layer 393, a buffer layer 394, and a common electrode 315. The buffer layer 312, the active layer 313, the buffer layer 314, the buffer layer 392, the light-emitting layer 393, and the buffer layer 394 each have an island-shaped top surface.

[0313] In this way, by forming separate buffer layers for the light-emitting element 390 and the light-receiving element 310, the degree of freedom in selecting materials for the buffer layers used for the light-emitting element 390 and the light-receiving element 310 is increased, making optimization easier. Furthermore, by using the common electrode 315 as a common layer, the manufacturing process is simplified and manufacturing costs can be reduced compared to when the light-emitting element 390 and the light-receiving element 310 are manufactured separately.

[0314] <Configuration example 3> A detailed structure of a display device that can be applied to a pixel portion of an electronic device according to one embodiment of the present invention will be described below. In particular, an example of a display device including a light-emitting and light-emitting element will be described.

[0315] In the following, the same parts as those described above will be referred to and explanations thereof may be omitted.

[0316] [Configuration Example 3-1] 26A shows a cross-sectional view of the display device 300G. The display device 300G has a light emitting / receiving element 390SR, a light emitting element 390G, and a light emitting element 390B.

[0317] The light emitting / receiving element 390SR functions as a light emitting element that emits red light 321R and as a photoelectric conversion element that receives light 322. The light emitting element 390G can emit green light 321G. The light emitting element 390B can emit blue light 321B.

[0318] The light emitting / receiving element 390SR has a pixel electrode 311, a buffer layer 312, an active layer 313, a light emitting layer 393R, a buffer layer 314, and a common electrode 315. The light emitting element 390G has a pixel electrode 391G, a buffer layer 312, a light emitting layer 393G, a buffer layer 314, and a common electrode 315. The light emitting element 390B has a pixel electrode 391B, a buffer layer 312, a light emitting layer 393B, a buffer layer 314, and a common electrode 315.

[0319] The buffer layer 312, the buffer layer 314, and the common electrode 315 are layers (common layers) common to the light emitting / receiving element 390SR, the light emitting element 390G, and the light emitting element 390B, and are provided across these elements. The active layer 313, the light emitting layer 393R, the light emitting layer 393G, and the light emitting layer 393B each have an island-shaped upper surface. Note that, in FIG. 26, an example is shown in which the stack of the active layer 313 and the light emitting layer 393R, the light emitting layer 393G, and the light emitting layer 393B are provided spaced apart from each other, but adjacent layers may have overlapping regions.

[0320] As with the display device 300D, the display device 300E, or the display device 300F, one or both of the buffer layer 312 and the buffer layer 314 may not be used as a common layer.

[0321] The pixel electrode 311 is electrically connected to one of the source and drain of the transistor 331. The pixel electrode 391G is electrically connected to one of the source and drain of the transistor 332G. The pixel electrode 391B is electrically connected to one of the source and drain of the transistor 332B.

[0322] With this configuration, a display device with higher resolution can be realized.

[0323] [Configuration Example 3-2] A display device 300H shown in FIG. 26B differs from the display device 300G described above mainly in that the configuration of the light emitting / receiving element 390SR is different.

[0324] The light emitting / receiving element 390SR has a light emitting / receiving layer 318R in place of the active layer 313 and the light emitting layer 393R.

[0325] The light emitting / receiving layer 318R functions both as a light emitting layer and an active layer. For example, a layer containing the above-mentioned light emitting material, an n-type semiconductor, and a p-type semiconductor can be used.

[0326] By adopting such a structure, the manufacturing process can be further simplified, which facilitates cost reduction.

[0327] (Embodiment 3) In this embodiment, a display device that can be applied to a pixel portion of an electronic device according to one embodiment of the present invention will be described.

[0328] <Example of display device configuration> 27A shows a block diagram of the display device 100. The display device 100 has a pixel section 11, a drive circuit section 12, a drive circuit section 13, a drive circuit section 14, a circuit section 15, and the like.

[0329] The pixel section 11 has a plurality of pixels 30 arranged in a matrix. Each pixel 30 has sub-pixels 21R, 21G, and 21B, and an imaging pixel 22. The sub-pixels 21R, 21G, and 21B each have a light-emitting element that functions as a display element. The imaging pixel 22 has a light-receiving element that functions as a photoelectric conversion element.

[0330] The pixel 30 is electrically connected to the wiring GL, the wiring SLR, the wiring SLG, the wiring SLB, the wiring TX, the wiring SE, the wiring RS, the wiring WX, etc. The wirings SLR, the wiring SLG, and the wiring SLB are electrically connected to the drive circuit unit 12. The wiring GL is electrically connected to the drive circuit unit 13. The drive circuit unit 12 functions as a source line drive circuit (also referred to as a source driver). The drive circuit unit 13 functions as a gate line drive circuit (also referred to as a gate driver).

[0331] The pixel 30 has subpixels 21R, 21G, and 21B. For example, the subpixel 21R is a subpixel that exhibits red, the subpixel 21G is a subpixel that exhibits green, and the subpixel 21B is a subpixel that exhibits blue. This allows the display device 100 to perform full-color display. Note that, although an example in which the pixel 30 has subpixels of three colors is shown here, the pixel 30 may have subpixels of four or more colors.

[0332] Subpixel 21R has a light-emitting element that emits red light. Subpixel 21G has a light-emitting element that emits green light. Subpixel 21B has a light-emitting element that emits blue light. Note that pixel 30 may have subpixels that have light-emitting elements that emit light of other colors. For example, pixel 30 may have, in addition to the above three subpixels, a subpixel that has a light-emitting element that emits white light or a subpixel that has a light-emitting element that emits yellow light.

[0333] The wiring GL is electrically connected to the sub-pixels 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 sub-pixels 21R, 21G, and 21B (not shown) arranged in the column direction (extension direction of the wiring SLR, etc.), respectively.

[0334] The imaging pixel 22 of the pixel 30 is electrically connected to the wiring TX, wiring SE, wiring RS, and wiring WX. The wiring TX, wiring SE, and wiring RS are each electrically connected to the drive circuit unit 14, and the wiring WX is electrically connected to the circuit unit 15.

[0335] The drive circuit unit 14 has a function of generating signals for driving the imaging pixels 22 and outputting them to the imaging pixels 22 via the wirings SE, TX, and RS. The circuit unit 15 has a function of receiving signals output from the imaging pixels 22 via the wirings WX and outputting them to the outside as image data. The circuit unit 15 functions as a readout circuit.

[0336] <Pixel circuit configuration example 1> FIG. 27B shows an example of a circuit diagram of a pixel 21 that can be used for the subpixels 21R, 21G, and 21B described above. The pixel 21 includes a transistor M1, a transistor M2, a transistor M3, a capacitor C1, and a light-emitting element EL. A wiring GL and a wiring SL are electrically connected to the pixel 21. The wiring SL corresponds to any one of the wirings SLR, SLG, and SLB shown in FIG. 27A.

[0337] The transistor M1 has a gate electrically connected to a wiring GL, one of a source and a drain electrically connected to a wiring SL, and the other electrically connected to one electrode of a capacitor C1 and the gate of the transistor M2. The transistor M2 has one of a source and a drain electrically connected to a wiring AL, and the other of the source and drain electrically connected to one electrode of a light-emitting element EL, the other electrode of the capacitor C1, and one of a source and a drain of the transistor M3. The transistor M3 has a gate electrically connected to a wiring GL, and the other of the source and drain electrically connected to a wiring RL. The light-emitting element EL has the other electrode electrically connected to a wiring CL.

[0338] The transistors M1 and M3 function as switches, and the transistor M2 functions as a transistor for controlling the current flowing through the light-emitting element EL.

[0339] Here, it is preferable that all of the transistors M1 to M3 be LTPS transistors. Alternatively, it is preferable that the transistors M1 and M3 be OS transistors and the transistor M2 be an LTPS transistor.

[0340] A transistor using an oxide semiconductor, which has a wider band gap and a lower carrier density than silicon, can achieve an extremely small off-state current. Therefore, the small off-state current allows charge stored in a capacitor connected in series with the transistor to be held for a long period of time. Therefore, it is preferable to use transistors including oxide semiconductors for the transistors M1 and M3 connected in series with the capacitor C1. Using transistors including oxide semiconductors as the transistors M1 and M3 can prevent charge stored in the capacitor C1 from leaking through the transistor M1 or M3. Furthermore, because charge stored in the capacitor C1 can be held for a long period of time, a still image can be displayed for a long period of time without rewriting data in the pixel 21.

[0341] The wiring SL is supplied with a data potential D. The wiring GL is supplied with a selection signal. The selection signal includes a potential that turns on a transistor and a potential that turns off a transistor.

[0342] A reset potential is applied to the wiring RL. An anode potential is applied to the wiring AL. A cathode potential is applied to the wiring CL. In the pixel 21, the anode potential is higher than the cathode potential. The reset potential applied to the wiring RL can be a potential such that the potential difference between the reset potential and the cathode potential is smaller than the threshold voltage of the light-emitting element EL. The reset potential can be a potential higher than the cathode potential, the same as the cathode potential, or a potential lower than the cathode potential.

[0343] <Pixel circuit configuration example 2> 27C shows an example of a circuit diagram of the imaging pixel 22. The imaging pixel 22 includes a transistor M5, a transistor M6, a transistor M7, a transistor M8, a capacitor C2, and a light receiving element PD.

[0344] The transistor M5 has a gate electrically connected to the wiring TX, one of a source and a drain electrically connected to the anode electrode of the light receiving element PD, and the other of the source and drain electrically connected to one of the source and drain of the transistor M6, a first electrode of the capacitor C2, and the gate of the transistor M7. The transistor M6 has a gate electrically connected to the wiring RS, and the other of the source and drain electrically connected to the wiring V1. The transistor M7 has one of a source and a drain electrically connected to the wiring V3, and the other of the source and drain electrically connected to one of the source and drain of the transistor M8. The transistor M8 has a gate electrically connected to the wiring SE, and the other of the source and drain electrically connected to the wiring WX. The light receiving element PD has a cathode electrode electrically connected to the wiring CL. The capacitor C2 has a second electrode electrically connected to the wiring V2.

[0345] The transistors M5, M6, and M8 function as switches, and the transistor M7 functions as an amplifier.

[0346] It is preferable that all of the transistors M5 to M8 be LTPS transistors. Alternatively, it is preferable that the transistors M5 and M6 be OS transistors and the transistor M7 be an LTPS transistor. In this case, the transistor M8 may be either an OS transistor or an LTPS transistor.

[0347] By using OS transistors as transistors M5 and M6, it is possible to prevent the potential held at the gate of transistor M7 based on the charge generated in light receiving element PD from leaking through transistor M5 or transistor M6.

[0348] For example, when imaging using the global shutter method, the period (charge retention period) from the end of the charge transfer operation to the start of the readout operation differs depending on the pixel. For example, when capturing an image in which all pixels have the same grayscale value, ideally, all pixels will obtain output signals with the same potential. However, if the length of the charge retention period differs from row to row, and the charges accumulated in the nodes of the pixels in each row leak over time, the potential of the pixel output signals will differ from row to row, resulting in image data with different grayscale levels for each row. Therefore, by using OS transistors as transistors M5 and M6, the potential change at the nodes can be minimized. In other words, even when imaging using the global shutter method, the change in grayscale of image data due to different charge retention periods can be minimized, thereby improving the quality of the captured image.

[0349] On the other hand, it is preferable to use an LTPS transistor using low-temperature polysilicon in the semiconductor layer as the transistor M7. LTPS transistors can achieve higher field-effect mobility than OS transistors and have excellent driving and current capabilities. Therefore, the transistor M7 can operate at a higher speed than the transistors M5 and M6. By using an LTPS transistor as the transistor M7, it is possible to quickly output to the transistor M8 a voltage corresponding to a minute potential based on the amount of light received by the light receiving element PD.

[0350] In other words, in the imaging pixel 22, transistors M5 and M6 have low leakage current, and transistor M7 has high driving capability, so that the charge received by the light receiving element PD and transferred via transistor M5 can be held without leakage and can be read out at high speed.

[0351] The transistor M8 functions as a switch that allows the output from the transistor M7 to flow to the wiring WX, and therefore does not necessarily require a small off-state current, high-speed operation, or the like, as in the transistors M5 to M7. Therefore, low-temperature polysilicon or an oxide semiconductor may be used for the semiconductor layer of the transistor M8.

[0352] 27B and 27C, the transistors are depicted as n-channel transistors, but p-channel transistors can also be used. The pixel circuit may be a CMOS circuit having n-channel transistors and p-channel transistors. For example, an n-channel OS transistor and a p-channel LTPS transistor can be suitably used in the pixel circuit.

[0353] The transistors of the pixel 21 and the imaging pixel 22 are preferably formed side by side on the same substrate.

[0354] <Pixel circuit configuration example 3> A circuit configuration different from the above will be described.

[0355] In a transistor having a pair of gates, when the pair of gates are electrically connected to each other and supplied with the same potential, the on-state current of the transistor is increased and the saturation characteristics are improved. A potential for controlling the threshold voltage of the transistor may be supplied to one of the pair of gates. Supplying a constant potential to one of the pair of gates can improve the stability of the electrical characteristics of the transistor. For example, one gate of the transistor may be electrically connected to a wiring to which a constant potential is supplied, or to its own source or drain.

[0356] 28A is an example in which the transistors M1 and M3 each have a pair of gates. The pair of gates of the transistors M1 and M3 are electrically connected. With this configuration, the period for writing data to the pixel 21 can be shortened.

[0357] 28B is an example in which a transistor having a pair of gates is used for the transistor M2 in addition to the transistors M1 and M3. The pair of gates of the transistor M2 are electrically connected. By using such a transistor for the transistor M2, the saturation characteristics are improved, which makes it easier to control the emission luminance of the light-emitting element EL, thereby improving the display quality.

[0358] 29A shows an example of an imaging pixel 22 in which transistors M5 and M6 are configured with a pair of gates connected to each other. This configuration can reduce the time required for the reset operation and the transfer operation.

[0359] The imaging pixel 22 shown in Fig. 29B is an example in which, in addition to the configuration shown in Fig. 29A, a transistor M8 is also configured with a pair of gates connected together, thereby reducing the time required for readout.

[0360] 29C is an example of an imaging pixel 22 in which, in addition to the configuration illustrated in FIG. 29B, a transistor M7 is also configured with a pair of gates connected together, which can further reduce the time required for readout.

[0361] (Fourth embodiment) In this embodiment, a more detailed structure of a display device that can be applied to a pixel portion of an electronic device according to one embodiment of the present invention will be described with reference to FIGS.

[0362] <Display device 100A> FIG. 30 shows a perspective view of the display device 100A, and FIG. 31 shows a cross-sectional view of the display device 100A.

[0363] The display device 100A has a configuration in which a substrate 152 and a substrate 151 are bonded together. In Fig. 30, the substrate 152 is clearly indicated by a dashed line.

[0364] The display device 100A has a pixel portion 162, a circuit 164, wiring 165, etc. Fig. 30 shows an example in which an IC (integrated circuit) 173 and an FPC 172 are mounted on the display device 100A. Therefore, the configuration shown in Fig. 30 can also be said to be a display module having the display device 100A, an IC, and an FPC.

[0365] The circuit 164 can be, for example, a scanning line driver circuit.

[0366] The wiring 165 has a function of supplying signals and power to the pixel portion 162 and the circuit 164. The signals and power are input to the wiring 165 from the outside via the FPC 172 or input to the wiring 165 from the IC 173.

[0367] 30 shows an example in which an IC 173 is provided on a substrate 151 by a COG (Chip On Glass) method or a COF (Chip on Film) method. The IC 173 may be, for example, an IC having a scanning line driving circuit or a signal line driving circuit. The display device 100A and the display module may be configured without an IC. Alternatively, the IC may be mounted on an FPC by a COF method or the like.

[0368] Figure 31 shows an example of a cross section of the display device 100A shown in Figure 30, with a portion of the area including the FPC 172, a portion of the area including the circuit 164, a portion of the area including the pixel section 162, and a portion of the area including the end portion cut away.

[0369] The display device 100A shown in FIG. 31 includes, between a substrate 151 and a substrate 152, a transistor 201, a transistor 205, a transistor 206, a transistor 207, a light-emitting element 190B, a light-emitting element 190G, a light-emitting element 190SR, and the like.

[0370] The substrate 152 and the insulating layer 214 are bonded via an adhesive layer 142. A solid sealing structure, a hollow sealing structure, or the like can be applied to seal the light emitting element 190B, the light emitting element 190G, and the light receiving / emitting element 190SR. In FIG. 31, a space 143 surrounded by the substrate 152, the adhesive layer 142, and the insulating layer 214 is filled with an inert gas (nitrogen, argon, etc.), and a hollow sealing structure is applied. The adhesive layer 142 may be provided overlapping the light emitting element 190B, the light emitting element 190G, and the light receiving / emitting element 190SR. Furthermore, the space 143 surrounded by the substrate 152, the adhesive layer 142, and the insulating layer 214 may be filled with a resin different from the adhesive layer 142.

[0371] The light-emitting element 190B has a layered structure in which a pixel electrode 191, a common layer 112, a light-emitting layer 193B, a common layer 114, and a common electrode 115 are layered in this order from the insulating layer 214 side. The pixel electrode 191 is connected to a conductive layer 222b of the transistor 207 through an opening provided in the insulating layer 214. The transistor 207 has a function of controlling driving of the light-emitting element 190B. An end of the pixel electrode 191 is covered with a partition wall 216. The pixel electrode 191 contains a material that reflects visible light, and the common electrode 115 contains a material that transmits visible light.

[0372] The light-emitting element 190G has a layered structure in which a pixel electrode 191, a common layer 112, a light-emitting layer 193G, a common layer 114, and a common electrode 115 are stacked in this order from the insulating layer 214 side. The pixel electrode 191 is connected to a conductive layer 222b of the transistor 206 through an opening provided in the insulating layer 214. The transistor 206 has a function of controlling driving of the light-emitting element 190G.

[0373] The light emitting / receiving element 190SR has a layered structure in which a pixel electrode 191, a common layer 112, an active layer 183, a light emitting layer 193R, a common layer 114, and a common electrode 115 are layered in this order from the insulating layer 214 side. The pixel electrode 191 is electrically connected to a conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. The transistor 205 has a function of controlling the driving of the light emitting / receiving element 190SR.

[0374] Light emitted by the light emitting element 190B, the light emitting element 190G, and the light receiving / emitting element 190SR is emitted toward the substrate 152. Furthermore, light is incident on the light receiving / emitting element 190SR via the substrate 152 and the space 143. It is preferable that the substrate 152 be made of a material that is highly transparent to visible light.

[0375] The pixel electrode 191 can be manufactured using the same material and the same process. The common layer 112, the common layer 114, and the common electrode 115 are commonly used for the light-emitting element 190B, the light-emitting element 190G, and the light-receiving / light-emitting element 190SR. The light-receiving / light-emitting element 190SR has a configuration in which an active layer 183 is added to the configuration of a light-emitting element that emits red light. Furthermore, the light-emitting element 190B, the light-emitting element 190G, and the light-receiving / light-emitting element 190SR can all have a common configuration except for the configurations of the active layer 183 and the light-emitting layers 193 of each color. This makes it possible to add a light-receiving function to the pixel section 162 of the display device 100A without significantly increasing the number of manufacturing processes.

[0376] A light-shielding layer BM is provided on the surface of substrate 152 facing substrate 151. The light-shielding layer BM has openings at positions overlapping with light-emitting element 190B, light-emitting element 190G, and light-receiving / light-emitting element 190SR. By providing the light-shielding layer BM, it is possible to control the range in which light is detected by light-receiving / light-emitting element 190SR. Furthermore, by providing the light-shielding layer BM, it is possible to prevent light from being directly incident on light-receiving / light-emitting element 190SR from light-emitting element 190G or light-emitting element 190B without passing through an object. Therefore, a sensor with low noise and high sensitivity can be realized.

[0377] The transistor 201, the transistor 205, the transistor 206, and the transistor 207 are all formed over a substrate 151. These transistors can be manufactured using the same material and through the same process.

[0378] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided over the substrate 151 in this order. A part of the insulating layer 211 functions as a gate insulating layer for each transistor. A part of the insulating layer 213 functions as a gate insulating layer for each transistor. The insulating layer 215 is provided to cover the transistor. The insulating layer 214 is provided to cover the transistor and functions as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0379] It is preferable that at least one insulating layer covering the transistor is 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.

[0380] The insulating layer 211, the insulating layer 213, and the insulating layer 215 are preferably formed using an inorganic insulating film. 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, a hafnium oxynitride film, a hafnium nitride 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, a neodymium oxide film, or the like may be used. Two or more of the above insulating films may be stacked. A base film may be provided between the substrate 151 and the transistor. The above inorganic insulating film may also be used for the base film.

[0381] 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 100A. This can prevent impurities from entering from the edge of the display device 100A 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 100A, so that the organic insulating film is not exposed at the edge of the display device 100A.

[0382] An organic insulating film is suitable for the insulating layer 214, which 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.

[0383] 31, an opening is formed in the insulating layer 214. This makes it possible to prevent impurities from entering the pixel section 162 from the outside through the insulating layer 214, even when an organic insulating film is used for the insulating layer 214. This makes it possible to improve the reliability of the display device 100A.

[0384] The transistor 201, the transistor 205, the transistor 206, and the transistor 207 each include a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as a source and a drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0385] 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.

[0386] The transistors 201, 205, 206, and 207 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 supplied with the same signal to drive the transistor. Alternatively, the threshold voltage of the transistor may be controlled by supplying a potential for controlling the threshold voltage to one of the two gates and a potential for driving to the other.

[0387] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor and a crystalline semiconductor (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0388] The semiconductor layer of the transistor preferably contains a metal oxide (also referred to as an oxide semiconductor), or may contain silicon.

[0389] The semiconductor layer preferably contains, for example, indium, M (wherein M is one or more elements selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more elements selected from aluminum, gallium, yttrium, and tin.

[0390] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also referred to as IGZO) for the semiconductor layer. Alternatively, it is preferable to use an oxide containing indium, gallium, zinc, and tin. Alternatively, it is preferable to use an oxide containing indium and zinc.

[0391] When the semiconductor layer 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 In:M:Zn=1:1:1 or a composition thereabout, In:M:Zn=1:1:1.2 or a composition thereabout, In:M:Zn=2:1:3 or a composition thereabout, In:M:Zn=3:1:2 or a composition thereabout, In:M:Zn=4:2:3 or a composition thereabout, In:M:Zn=4:2:4.1 or a composition thereabout, In:M:Zn=5:1:3 or a composition thereabout, In:M:Zn=5:1:6 or a composition thereabout, In:M:Zn=5:1:7 or a composition thereabout, In:M:Zn=5:1:8 or a composition thereabout, In:M:Zn=10:1:3 or a composition thereabout, In:M:Zn=6:1:6 or a composition thereabout, and In:M:Zn=5:2:5 or a composition thereabout. The term "nearby composition" includes a range of ±30% of the desired atomic ratio.

[0392] For example, when describing a composition with an atomic ratio of In:Ga:Zn=4:2:3 or thereabout, this includes a case where, when the atomic ratio of In is 4, the atomic ratio of Ga is 1 to 3 and the atomic ratio of Zn is 2 to 4. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn=5:1:6 or thereabout, this includes a case where, when the atomic ratio of In is 5, the atomic ratio of Ga is greater than 0.1 and less than 2 and the atomic ratio of Zn is greater than 5 and less than 7. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn=1:1:1 or thereabout, this includes a case where, when the atomic ratio of In is 1, the atomic ratio of Ga is greater than 0.1 and less than 2 and the atomic ratio of Zn is greater than 0.1 and less than 2.

[0393] Different semiconductor materials may be used for semiconductor layers in which channels of the transistors 201, 205, 206, and 207 are formed. For example, a transistor including silicon (a Si transistor) may be used as the transistor 201, and transistors including metal oxide (OS transistors) may be used as the transistors 205, 206, and 207. As the Si transistor, for example, an LTPS transistor may be used.

[0394] The transistors included in the circuit 164 may have the same structure as or different from the transistors included in the pixel portion 162. The transistors included in the circuit 164 may all have the same structure or may have two or more types. Similarly, the transistors included in the pixel portion 162 may all have the same structure or may have two or more types.

[0395] A connection section 204 is provided in an area of ​​the substrate 151 where the substrate 152 does not overlap. In the connection section 204, the wiring 165 is electrically connected to the FPC 172 via a conductive layer 166 and a connection layer 242. The conductive layer 166, which is obtained by processing the same conductive film as the pixel electrode 191, is exposed on the upper surface of the connection section 204. This allows the connection section 204 and the FPC 172 to be electrically connected via the connection layer 242.

[0396] Various optical members can be disposed on the outside of the substrate 152. 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. In addition, 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 scratches caused by use, an impact absorbing layer, etc. may be disposed on the outside of the substrate 152.

[0397] The substrate 151 and the substrate 152 can each be made of glass, quartz, ceramic, sapphire, resin, etc. Using a flexible material for the substrate 151 and the substrate 152 can increase the flexibility of the display device.

[0398] The adhesive layer can be made of various curable adhesives, such as photocurable 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.

[0399] The connection layer may be made of an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0400] 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.

[0401] 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 can also be used for conductive layers such as various wirings and electrodes constituting a display device, or conductive layers (conductive layers functioning as pixel electrodes or common electrodes) of light-emitting elements and light-emitting / receiving elements.

[0402] 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.

[0403] <Display device 100B> A cross-sectional view of the display device 100B is shown in FIG.

[0404] The display device 100B differs from the display device 100A mainly in that it has a protective layer 195. Detailed descriptions of the same configuration as the display device 100A will be omitted.

[0405] By providing a protective layer 195 that covers the light-emitting element 190B, the light-emitting element 190G, and the light-receiving / light-emitting element 190SR, it is possible to prevent impurities such as water from entering the light-emitting element 190B, the light-emitting element 190G, and the light-receiving / light-emitting element 190SR, thereby improving the reliability of the light-emitting element 190B, the light-emitting element 190G, and the light-receiving / light-emitting element 190SR.

[0406] In a region 228 near the edge of the display device 100B, it is preferable that the insulating layer 215 and the protective layer 195 contact each other through the opening in the insulating layer 214. In particular, it is preferable that the inorganic insulating film of the insulating layer 215 and the inorganic insulating film of the protective layer 195 contact each other. This makes it possible to prevent impurities from entering the pixel section 162 from the outside through the organic insulating film. This can therefore improve the reliability of the display device 100B.

[0407] The protective layer 195 may have a single layer or a multilayer structure, and may have, for example, a three-layer structure including an inorganic insulating layer on the common electrode 115, an organic insulating layer on the inorganic insulating layer, and an inorganic insulating layer on the organic insulating layer. In this case, it is preferable that the end of the inorganic insulating layer extends further outward than the end of the organic insulating layer.

[0408] Furthermore, a lens may be provided in the area overlapping with the light emitting / receiving element 190SR, thereby improving the sensitivity and accuracy of the sensor using the light emitting / receiving element 190SR.

[0409] The lens preferably has a refractive index of 1.3 or more and 2.5 or less. The lens can be formed using at least one of an inorganic material and an organic material. For example, a material containing a resin can be used for the lens. Also, a material containing at least one of an oxide and a sulfide can be used for the lens.

[0410] Specifically, resins containing chlorine, bromine, or iodine, resins containing heavy metal atoms, resins containing aromatic rings, resins containing sulfur, etc. can be used for the lenses. Alternatively, materials containing resin and nanoparticles of a material with a higher refractive index than the resin can be used for the lenses. Titanium oxide or zirconium oxide can be used for the nanoparticles.

[0411] Cerium oxide, hafnium oxide, lanthanum oxide, magnesium oxide, niobium oxide, tantalum oxide, titanium oxide, yttrium oxide, zinc oxide, oxides containing indium and tin, or oxides containing indium, gallium, and zinc can be used for the lens. Alternatively, zinc sulfide can be used for the lens.

[0412] In the display device 100B, the protective layer 195 and the substrate 152 are bonded together by an adhesive layer 142. The adhesive layer 142 is provided to overlap the light-emitting element 190B, the light-emitting element 190G, and the light-receiving / light-emitting element 190SR, respectively, and a solid sealing structure is applied to the display device 100B.

[0413] <Display device 100C> A cross-sectional view of the display device 100C is shown in FIG. 33A.

[0414] The display device 100C differs from the display device 100B in the structure of the transistors.

[0415] The display device 100C includes a transistor 208, a transistor 209, and a transistor 210 over a substrate 151.

[0416] The transistor 208, the transistor 209, and the transistor 210 each include a conductive layer 221 functioning as a gate, an insulating layer 211 functioning as a gate insulating layer, a semiconductor layer including a channel formation region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 functioning as a gate insulating layer, a conductive layer 223 functioning as a gate, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel formation region 231i. The insulating layer 225 is located between the conductive layer 223 and the channel formation region 231i.

[0417] The conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215, respectively. One of the conductive layer 222a and the conductive layer 222b functions as a source, and the other functions as a drain.

[0418] The pixel electrode 191 of the light emitting element 190G is electrically connected to one of a pair of low resistance regions 231n of the transistor 208 via the conductive layer 222b.

[0419] The pixel electrode 191 of the light emitting / receiving element 190SR is electrically connected to the other of the pair of low resistance regions 231n of the transistor 209 via the conductive layer 222b.

[0420] 33A shows an example in which the insulating layer 225 covers the top and side surfaces of the semiconductor layer. On the other hand, in the transistor 202 shown in FIG. 33B, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231 but does not overlap with the low-resistance region 231n. For example, the structure shown in FIG. 33B can be manufactured by processing the insulating layer 225 using the conductive layer 223 as a mask. In FIG. 33B, the insulating layer 215 is provided to cover the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and the conductive layer 222b are each connected to the low-resistance region 231n through openings in the insulating layer 215. Furthermore, an insulating layer 218 may be provided to cover the transistor.

[0421] The display device 100C differs from the display device 100B in that it does not have the substrate 151 and the substrate 152, but has the substrate 153, the substrate 154, the adhesive layer 155, and the insulating layer 212.

[0422] The substrate 153 and the insulating layer 212 are bonded together by an adhesive layer 155. The substrate 154 and the protective layer 195 are bonded together by an adhesive layer 142.

[0423] The display device 100C is fabricated by transferring the insulating layer 212, the transistor 208, the transistor 209, the transistor 210, the light-emitting element 190SR, the light-emitting element 190G, and the like, which are formed on a fabrication substrate, onto a substrate 153. The substrate 153 and the substrate 154 are preferably flexible, which can increase the flexibility of the display device 100C.

[0424] The insulating layer 212 can be formed using the inorganic insulating film that can be used for the insulating layers 211, 213, and 215.

[0425] <Display device 100D> A cross-sectional view of the display device 100D is shown in FIG. 34A.

[0426] The display device 100D differs from the display device 100C in the structure of the transistor 210.

[0427] The display device 100D includes a transistor 208, a transistor 209, and a transistor 210A. An enlarged view of the transistor 210A is shown in Figure 34B.

[0428] The semiconductor layer of the transistor 210A is formed on a different plane from the semiconductor layers of the transistors 208 and 209. For example, an LTPS transistor can be used as the transistor 210A, and OS transistors can be used as the transistors 208 and 209.

[0429] The transistor 210A includes a conductive layer 251 functioning as a bottom gate, an insulating layer 217 functioning as a first gate insulating layer, a semiconductor layer having a channel formation region 252i and a pair of low-resistance regions 252n, conductive layers 254a and 254b connected to one of the pair of low-resistance regions 252n, a conductive layer 254b connected to the other of the pair of low-resistance regions 252n, an insulating layer 219 functioning as a second gate insulating layer, a conductive layer 253 functioning as a top gate, and an insulating layer 211 covering the conductive layer 253.

[0430] The insulating layers 217 and 219 can be formed using the same inorganic insulating films as those used for the insulating layers 211 and 225, respectively.

[0431] The conductive layer 254a and the conductive layer 254b are electrically connected to the low-resistance region 252n through openings provided in the insulating layer 219 and the insulating layer 211. One of the conductive layer 254a and the conductive layer 254b functions as a source, and the other functions as a drain.

[0432] An insulating layer 225 and an insulating layer 215 functioning as protective layers are provided over the transistor 210A. The conductive layer 255a and the conductive layer 255b are electrically connected to the conductive layer 254a and the conductive layer 254b through openings provided in the insulating layer 225 and the insulating layer 215, respectively.

[0433] 34A shows a structure in which the conductive layer 255a is electrically connected to one of the pair of low-resistance regions 252n through the conductive layer 254a and the conductive layer 255b is electrically connected to the other of the pair of low-resistance regions 252n through the conductive layer 254b, but one embodiment of the present invention is not limited to this. A structure in which the conductive layers 254a and 254b are not provided and the conductive layer 255a is in contact with one of the pair of low-resistance regions 252n and the conductive layer 255b is in contact with the other of the pair of low-resistance regions 252n may also be used.

[0434] 34A illustrates a structure in which the conductive layer 253 is provided on the same surface as the bottom gate of the transistor 208 and the bottom gate of the transistor 209. The conductive layer 253 can be formed using the same material as the bottom gate of the transistor 208 and the bottom gate of the transistor 209. The conductive layer 253 is preferably formed by processing the same conductive film as the bottom gate of the transistor 208 and the bottom gate of the transistor 209. By processing and forming the conductive layer 253 using the same conductive film, the process can be simplified.

[0435] 34A illustrates a structure in which the conductive layers 255a and 255b are provided on the same plane as the source and drain of the transistor 208 and the source and drain of the transistor 209. The conductive layers 255a and 255b can be formed using the same materials as the source and drain of the transistor 208 and the source and drain of the transistor 209. The conductive layers 255a and 255b are preferably formed by processing the same conductive film as the source and drain of the transistor 208 and the source and drain of the transistor 209. By processing and forming the same conductive film, the process can be simplified.

[0436] As described above, in the display device of this embodiment, a sub-pixel that exhibits one of the colors is provided with a light-receiving / light-emitting element instead of a light-emitting element. The light-receiving / light-emitting element functions as both a light-emitting element and a light-receiving element, so that the pixel can be given a light-receiving function without increasing the number of sub-pixels included in the pixel. Furthermore, the pixel can be given a light-receiving function without reducing the resolution of the display device or the aperture ratio of each sub-pixel.

[0437] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0438] (Embodiment 5) 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.

[0439] The metal oxide preferably contains at least indium or zinc. It is particularly preferable that it contains indium and zinc. It is also preferable that it contains aluminum, gallium, yttrium, tin, or the like in addition to these. It may also contain one or more elements selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, and the like.

[0440] 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, an atomic layer deposition (ALD) method, or the like.

[0441] <Classification of crystal structures> Examples of the crystalline structure of oxide semiconductors include amorphous (including completely amorphous), c-axis-aligned crystalline (CAAC), nanocrystalline (nc), cloud-aligned composite (CAC), single crystal, and polycrystal.

[0442] The crystalline structure of a film or substrate can be evaluated using X-ray diffraction (XRD) spectra. For example, it can be evaluated using XRD spectra obtained by GIXD (Grazing-Incidence XRD) measurements. The GIXD method is also called the thin film method or the Seemann-Bohlin method.

[0443] For example, for a quartz glass substrate, the peak shape of the XRD spectrum is nearly symmetrical. On the other hand, for an IGZO film with 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.

[0444] The crystalline structure of a film or substrate can be evaluated by the diffraction pattern (also called the nanobeam electron diffraction pattern) observed using 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 IGZO film deposited at room temperature, rather than a halo. For this reason, it is estimated that an IGZO film deposited at room temperature is in an intermediate state that is neither crystalline nor amorphous, and therefore it cannot be concluded that it is in an amorphous state.

[0445] <Oxide semiconductor structure> Note that oxide semiconductors may be classified differently depending on their structures. For example, oxide semiconductors are divided 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, amorphous-like oxide semiconductors (a-like OSs), amorphous oxide semiconductors, and the like.

[0446] Here, the above-mentioned CAAC-OS, nc-OS, and a-like OS will be described in detail.

[0447] [CAAC-OS] CAAC-OS is an oxide semiconductor having multiple crystalline regions, each with its c-axis aligned in a specific direction. The specific direction can be the thickness direction of the CAAC-OS film, the normal direction to the surface on which the CAAC-OS film is formed, or the normal direction to the surface of the CAAC-OS film. A crystalline region is a region with periodic atomic arrangement. If the atomic arrangement is considered as a lattice arrangement, a crystalline region can also be a region with a uniform lattice arrangement. Furthermore, CAAC-OS has a region where multiple crystalline regions are connected in the ab-plane direction, and the region may have distortion. Note that distortion refers to a location where the lattice arrangement changes between a region with a uniform lattice arrangement and a region with a different uniform lattice arrangement in the region where multiple crystalline regions are connected. In other words, CAAC-OS is an oxide semiconductor with a c-axis aligned but no clear orientation in the ab-plane direction.

[0448] 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 one 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 nm.

[0449] In an In-M-Zn oxide (wherein element M is one or more elements selected from aluminum, gallium, yttrium, tin, titanium, etc.), the 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 element M, zinc (Zn), and oxygen (hereinafter referred to as an (M, Zn) layer) are stacked. Note that indium and element M are mutually substituted. Therefore, the (M, Zn) layer may contain indium. Furthermore, the In layer may contain element M. Furthermore, the In layer may contain Zn. The layered structure is observed as a lattice image in, for example, a high-resolution transmission electron microscope (TEM) image.

[0450] When the CAAC-OS film is subjected to structural analysis using, for example, an XRD apparatus, a peak indicating c-axis orientation is detected at or near 2θ=31° in out-of-plane XRD measurement using θ / 2θ scan. Note that the position of the peak indicating c-axis orientation (2θ value) may vary depending on the type and composition of the metallic elements constituting the CAAC-OS.

[0451] For example, in the electron diffraction pattern of a CAAC-OS film, multiple bright spots are observed, and the spots are observed at positions that are point-symmetric with respect to the spot of the incident electron beam that has passed through the sample (also called the direct spot).

[0452] When the crystalline region is observed from the specific direction, the lattice arrangement within the crystalline region is basically a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be non-regular hexagonal. Furthermore, the distortion may have a pentagonal, heptagonal, or other lattice arrangement. In the CAAC-OS, no clear grain boundaries are observed even near the distortion. This indicates that the formation of grain boundaries is suppressed by the distortion of the lattice arrangement. This is thought to be because the CAAC-OS can tolerate distortion due to the lack of close-packed oxygen atom arrangement in the ab-plane direction and the change in interatomic bond distance caused by metal atom substitution.

[0453] A crystal structure with clear grain boundaries is called polycrystalline. Grain boundaries act as recombination centers, trapping carriers and potentially causing a decrease in the on-state current and field-effect mobility of a transistor. Therefore, CAAC-OS, which lacks clear grain boundaries, is one of the crystalline oxides with a crystal structure suitable for use in the semiconductor layer of a transistor. Zn is preferred for use in 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.

[0454] CAAC-OS is an oxide semiconductor with high crystallinity and no clear grain boundaries. Therefore, it can be said that the CAAC-OS is less susceptible to a decrease in electron mobility due to grain boundaries. Furthermore, since the crystallinity of an oxide semiconductor can be reduced by the inclusion of impurities or the generation of defects, the CAAC-OS can also be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Therefore, oxide semiconductors with CAAC-OS have stable physical properties. Therefore, oxide semiconductors with CAAC-OS are heat-resistant and highly reliable. Furthermore, the CAAC-OS is stable even under high temperatures (so-called thermal budgets) during the manufacturing process. Therefore, using a CAAC-OS for an OS transistor can increase the flexibility of the manufacturing process.

[0455] [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 microcrystalline structures. The size of the microcrystalline structures is, for example, 1 nm to 10 nm, particularly 1 nm to 3 nm, and therefore these microcrystalline structures are also called nanocrystalline structures. Furthermore, the nc-OS exhibits no regularity in the crystal orientation between different nanocrystalline structures. Therefore, the entire film lacks orientation. Therefore, depending on the analytical 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 peaks indicating crystallinity are detected in out-of-plane XRD measurements using θ / 2θ scanning. Furthermore, when an nc-OS film is subjected to electron diffraction (also known as selected-area electron diffraction) using an electron beam with a probe diameter larger than that of nanocrystalline structures (e.g., 50 nm or larger), a halo-like diffraction pattern is observed. On the other hand, when electron diffraction (also called nanobeam electron diffraction) is performed on an nc-OS film using an electron beam with a probe diameter close to or smaller than the size of the nanocrystals (for example, 1 nm to 30 nm), an electron diffraction pattern can be obtained in which multiple spots are observed within a ring-shaped region centered on the direct spot.

[0456] [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 CAAC-OS. Furthermore, the a-like OS has a higher hydrogen concentration in the film than the nc-OS and CAAC-OS.

[0457] <Oxide semiconductor structure> Next, the above-mentioned CAC-OS will be described in detail, which relates to the material composition.

[0458] [CAC-OS] CAC-OS is a material structure in which elements constituting a metal oxide are unevenly distributed in a size range of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or a similar size range. Hereinafter, a metal oxide in which one or more metal elements are unevenly distributed and the regions containing the metal elements are mixed in a size range of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or a similar size range, is also referred to as a mosaic or patch state.

[0459] Furthermore, CAC-OS has a mosaic structure in which the material is separated into first and second regions, and the first regions are distributed throughout the film (hereinafter also referred to as a cloud structure). That is, CAC-OS is a composite metal oxide having a structure in which the first and second regions are mixed.

[0460] 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.

[0461] 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 rephrased as a region whose main component is In. The second region can be rephrased as a region whose main component is Ga.

[0462] It should be noted that there are cases where a clear boundary between the first region and the second region cannot be observed.

[0463] CAC-OS in In-Ga-Zn oxide refers to a material structure containing In, Ga, Zn, and O, with some regions primarily composed of Ga and other regions primarily composed of In randomly arranged mosaics. Therefore, it is presumed that CAC-OS has a structure in which metal elements are distributed nonuniformly.

[0464] The CAC-OS can be formed, for example, by a sputtering method under conditions where the substrate is not intentionally heated. When the CAC-OS is formed by a sputtering method, 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 ratio of oxygen gas to the total flow rate of deposition gas during deposition, the better. For example, the flow rate ratio of oxygen gas to the total flow rate of deposition gas during deposition is preferably 0% or more and less than 30%, and more preferably 0% or more and 10% or less.

[0465] For example, in the case of CAC-OS in In-Ga-Zn oxide, EDX mapping obtained using EDX (Energy Dispersive X-ray spectroscopy) confirms that the CAC-OS has a structure in which a region mainly composed of In (first region) and a region mainly composed of Ga (second region) are unevenly distributed and mixed.

[0466] 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).

[0467] 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.

[0468] Therefore, when 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 (the ability to turn on / off). In other words, CAC-OS has a conductive function in part of the material and an insulating function in part of the material, and the material as a whole functions as a semiconductor. By separating the conductive function from the insulating function, both functions can be maximized. Therefore, by using CAC-OS in a transistor, a high on-current (I on ), high field-effect mobility (μ), and good switching behavior can be achieved.

[0469] Transistors using CAC-OS have high reliability and are therefore ideal for various semiconductor devices such as display devices.

[0470] Oxide semiconductors have a variety of structures, each with 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.

[0471] <Transistors containing oxide semiconductors> Next, a case where the oxide semiconductor is used in a transistor will be described.

[0472] By using the oxide semiconductor for a transistor, a transistor with high field-effect mobility and high reliability can be realized.

[0473] For the transistor, an oxide semiconductor with a low carrier concentration is preferably used. For example, the carrier concentration of the oxide semiconductor is 1×10 17 cm -3 Less than 1 × 10 15 cm -3 or less, more preferably 1 × 10 13 cm -3Less than or equal to 1×10 11 cm -3 or less, more preferably 1 × 10 10 cm -3 Less than 1 x 10 -9 cm -3 That is all. Note that in order to reduce the carrier concentration of an oxide semiconductor film, the impurity concentration in the oxide semiconductor film may be reduced to reduce 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 also be referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor.

[0474] 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.

[0475] Charges trapped in the trap states of an oxide semiconductor take a long time to dissipate 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.

[0476] Therefore, in order to stabilize the electrical characteristics of a transistor, it is effective to reduce the impurity concentration in the oxide semiconductor. Furthermore, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in the adjacent film. Impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, silicon, and the like.

[0477] <Impurities> Here, the influence of each impurity in an oxide semiconductor will be described.

[0478] When an oxide semiconductor contains silicon or carbon, which is one of the Group 14 elements, defect levels are formed in the oxide semiconductor. Therefore, the concentration of silicon or carbon in the oxide semiconductor and the concentration of silicon or carbon near the interface with the oxide semiconductor (concentration obtained by secondary ion mass spectrometry (SIMS)) are calculated to be 2×10 18 atoms / cm 3 Less than or equal to 2 x 10 17 atoms / cm 3 The following applies.

[0479] When an oxide semiconductor contains an alkali metal or alkaline earth metal, defect levels may be formed and carriers may be generated. Therefore, a transistor using an oxide semiconductor containing an alkali metal or alkaline earth metal is likely to have normally-on characteristics. Therefore, when the concentration of the alkali metal or alkaline earth metal in the oxide semiconductor obtained by SIMS is 1×10 18 atoms / cm 3 Less than or equal to 2 x 10 16 atoms / cm 3 Do the following:

[0480] When nitrogen is contained in an oxide semiconductor, electrons serving as carriers are generated, the carrier concentration increases, and the semiconductor is likely to become n-type. As a result, a transistor using an oxide semiconductor containing nitrogen as a semiconductor tends to have normally-on characteristics. Alternatively, when nitrogen is contained in an oxide semiconductor, trap states may be formed. As a result, the electrical characteristics of the transistor may become unstable. For this reason, the nitrogen concentration in the oxide semiconductor obtained by SIMS is set to 5×10 19 atoms / cm 3 Less than 5 x 10 18 atoms / cm 3 Less than or equal to 1×10 18 atoms / cm 3 Less than 5 × 10, more preferably 17 atoms / cm 3 Do the following:

[0481] Hydrogen contained in an oxide semiconductor reacts with oxygen bonded to a metal atom to form water, which may form an oxygen vacancy. When hydrogen enters the oxygen vacancy, electrons serving as carriers may be generated. Furthermore, some of the hydrogen may bond with oxygen bonded to a metal atom to generate electrons serving as carriers. Therefore, a transistor using an oxide semiconductor containing hydrogen is likely to have normally-on characteristics. For this reason, it is preferable to reduce the amount of hydrogen in the oxide semiconductor as much as possible. Specifically, when the hydrogen concentration in an oxide semiconductor obtained by SIMS is 1×10 20 atoms / cm 3 Less than 1 x 10 19 atoms / cm 3 less than 5 × 10 18 atoms / cm 3 less than 1×10 18 atoms / cm 3 Make it less than.

[0482] When an oxide semiconductor with sufficiently reduced impurities is used for a channel formation region of a transistor, stable electrical characteristics can be obtained.

[0483] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0484] (Sixth embodiment) In this embodiment, electronic devices of one embodiment of the present invention will be described with reference to FIGS. 35A and 35B.

[0485] In an electronic device according to one embodiment of the present invention, a pixel portion has a function of detecting light, and therefore the pixel portion can perform biometric authentication and detect a touch operation (contact or approach), etc., thereby improving the functionality and convenience of the electronic device.

[0486] Examples of electronic devices include electronic devices with relatively large screens such as television sets, desktop or notebook personal computers, computer monitors, digital signage, large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound playback devices.

[0487] The electronic device of this embodiment may have a sensor (including a function to measure 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 rays).

[0488] The electronic device of the present embodiment can have various functions, such as a function of displaying various information (still images, moving images, text images, etc.) on a pixel portion, a touch panel function, a function of displaying a calendar, date, time, etc., a function of executing various software (programs), a wireless communication function, a function of reading out programs or data recorded on a recording medium, etc.

[0489] The electronic device 6500 shown in FIG. 35A is a wearable portable information terminal.

[0490] The electronic device 6500 includes a housing 6501, a pixel portion 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508. The pixel portion 6502 has a touch panel function.

[0491] The display device of one embodiment of the present invention can be applied to the pixel portion 6502.

[0492] FIG. 35B is a schematic cross-sectional view including the end of the housing 6501 on the microphone 6506 side.

[0493] 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.

[0494] 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).

[0495] In a region outside the pixel 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.

[0496] The flexible display of one embodiment of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. In addition, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted thereon while keeping the thickness of the electronic device small. 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 pixel portion, an electronic device with a narrow frame can be realized.

[0497] When the display device of one embodiment of the present invention is used for the display panel 6511, an image can be captured in the pixel portion 6502. For example, a fingerprint can be captured on the display panel 6511 and fingerprint authentication can be performed.

[0498] The pixel portion 6502 further includes a touch sensor panel 6513, which allows the pixel 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.

[0499] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification. [Explanation of symbols]

[0500] C1: capacitor, C2: capacitor, M1: transistor, M2: transistor, M3: transistor, M5: transistor, M6: transistor, M7: transistor, M8: transistor, V1: wiring, V2: wiring, V3: wiring, 10: electronic device, 10A: electronic device, 11: pixel unit, 12: drive circuit unit, 13: drive circuit unit, 14: drive circuit unit, 15: circuit unit, 21: pixel, 21B: sub-pixel, 21G: sub-pixel, 21R: sub-pixel, 22: imaging pixel, 30: pixel, 100: display device, 100A: display device, 100B: display device, 100C: display device, 100D: display device, 112: common layer, 114: common layer, 115: common electrode, 142: adhesive layer, 143: space, 151: substrate, 152: substrate, 153: substrate, 154: substrate, 155: adhesive layer, 162: pixel portion, 164: circuit, 165: wiring, 166: conductive layer, 172: FPC, 173: IC, 183: active layer, 190B: light-emitting element, 190G: light-emitting element, 190SR: light-emitting element, 191: pixel electrode, 193: light-emitting layer, 193B: light-emitting layer, 193G: light-emitting layer, 193R: light-emitting layer, 195: protective layer, 200: display device, 200A: display device, 200B: display device, 201 : transistor, 202: transistor, 204: connection portion, 205: transistor, 206: transistor, 207: transistor, 208: transistor, 209: transistor, 210: transistor, 210A: transistor, 211: insulating layer, 212: insulating layer, 213: insulating layer, 214: insulating layer, 215: insulating layer, 216: partition wall, 217: insulating layer, 218: insulating layer, 219: insulating layer, 221: conductive layer, 222a: conductive layer, 222b: conductive layer, 223: conductive layer, 225: insulating layer, 228: region, 231: semiconductor layer, 231i: channel formation region, 231n: low resistance region, 242: connection layer, 251: conductive layer, 252i: channel formation region, 252n: low resistance region, 253: conductive layer, 254a: conductive layer, 254b: conductive layer, 255a: conductive layer, 255b: conductive layer, 270B: light emitting element, 270G: light emitting element, 270PD: light receiving element, 270R: light emitting element, 270SR: light receiving / emitting element, 271: pixel electrode, 273: active layer, 275: common electrode, 277: electrode, 278: electrode, 280A: pixel portion, 280B: pixel portion, 280C: pixel portion, 281: hole injection layer, 281-2: hole transport layer, 282: hole transport layer,282-1: hole transport layer, 282-2: hole transport layer, 283: light emitting layer, 283B: light emitting layer, 283G: light emitting layer, 283R: light emitting layer, 284: electron transport layer, 285: electron injection layer, 289: layer, 300A: display device, 300B: display device, 300C: display device, 300D: display device, 300E: display device, 300F: display device, 300G: display device, 300H: display device, 310: light receiving element, 311: pixel electrode, 312: buffer layer, 313: active layer, 314: buffer layer, 315: common electrode, 318R: light receiving and emitting layer, 321: visible light, 321B: light, 321 G: light, 321R: light, 322: light, 323: light, 324: reflected light, 331: transistor, 332: transistor, 332B: transistor, 332G: transistor, 342: adhesive layer, 349: lens, 351: substrate, 352: substrate, 358: light-shielding layer, 390: light-emitting element, 390B: light-emitting element, 390G: light-emitting element, 390SR: light-receiving element, 391: pixel electrode, 391B: pixel electrode, 391G: pixel electrode, 392: buffer layer, 393: light-emitting layer, 393B: light-emitting layer, 393G: light-emitting layer, 393R: light-emitting layer, 394: buffer layer, 395: protective layer, 401: control unit, 402: pixel unit, 403: sensor unit, 404: memory unit, 405: display element, 405B: display element, 405G: display element, 405IR: display element, 405R: display element, 405W: display element, 405X: display element, 406: light receiving element, 407: authentication unit, 408: touch sensor, 413R: light receiving / emitting element, 414: insulating layer, 416: partition wall, 420: electronic device, 420A: electronic device, 422: pixel unit, 425: area, 426: image, 431: housing, 433: operation button, 435: band, 437: fastener, 438: light emitting element, 438a: light emitting element child, 438b: light-emitting element, 439: light-receiving element, 451a: authentication information, 451b: authentication information, 461: wrist, 462: finger, 463: finger, 463a: finger, 463b: finger, 465: blood vessel, 467: fingerprint, 469: contact portion, 471: substrate, 472: substrate, 473: functional layer, 475: stylus, 477: trajectory, 6500: electronic device, 6501: housing, 6502: pixel portion, 6503: power button, 6504: button, 6505: speaker, 6506: microphone, 6507: camera, 6508: light source, 6510: protective member, 6511: display panel, 6512: optical member,6513: Touch sensor panel, 6515: FPC, 6516: IC, 6517: Printed circuit board, 6518: Battery,

Claims

[Claim 1] The device has a pixel unit, a sensor unit, an authentication unit, and a housing, the pixel unit includes a display element and a light receiving element, the pixel unit has a function of lighting the display element, the pixel unit has a function of capturing an image of an object that touches the pixel unit using the light receiving element and acquiring authentication information; the sensor unit has a function of detecting a state of attachment to or detachment from a living body or an object, the authentication unit has a function of performing authentication processing using the authentication information, the housing has a first surface and a second surface opposite to the first surface, the pixel unit is located on the first surface, The electronic device wherein the sensor unit is located on the second surface.

Images