Display device

Abstract

To provide a display device capable of picking up an image with high sensitivity.SOLUTION: A display device includes first to third switches, a first transistor, a second transistor, and a light receiving / emitting element. The first switch is electrically connected to the gate of the first transistor. The second switch is positioned between one of the source and drain of the first transistor and one electrode of the light receiving / emitting element. The third switch is positioned between one electrode of the light receiving / emitting element and the gate of the second transistor. In the first transistor, a first potential is given to the other of the source and drain. In the light receiving / emitting element, a second potential is given to the other electrode. The light receiving / emitting element has a function of emitting light in a first color and a function of receiving light in a second color.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] One aspect of the present invention relates to a display device. One aspect of the present invention relates to a display device having an imaging function.

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

Background Art

[0003] In recent years, display devices have been required to have higher definition in order to display high-resolution images. Further, in information terminal devices such as smartphones, tablet terminals, and notebook PCs (personal computers), in addition to higher definition, display devices are required to consume less power. Furthermore, there is a demand for display devices to which various functions are added, such as a function as a touch panel or a function of imaging fingerprints for authentication, in addition to displaying images.

[0004] As a display device, for example, a light-emitting device having a light-emitting element has been developed. A light-emitting element (also referred to as an EL element) that utilizes the electroluminescence (hereinafter abbreviated as EL) phenomenon has characteristics such as being easily thinned and lightened, being able to respond quickly to an input signal, and being drivable using a DC constant voltage power supply, and has been applied to display devices. For example, Patent Document 1 discloses a flexible light-emitting device to which an organic EL element is applied.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] One aspect of the present invention is to provide a display device having an imaging function as one of the problems. One aspect of the present invention is to provide an imaging device or a display device capable of capturing a high-definition image as one of the problems. One aspect of the present invention is to provide an imaging device or a display device capable of performing high-sensitivity imaging as one of the problems. One aspect of the present invention is to provide an imaging device or a display device in which the influence of noise is suppressed as one of the problems. One aspect of the present invention is to provide a display device capable of acquiring biometric information such as fingerprints as one of the problems. One aspect of the present invention is to provide a display device that functions as a touch panel as one of the problems.

[0007] Also, one aspect of the present invention is to reduce the number of components of an electronic device as one of the problems. One aspect of the present invention is to provide a display device, an imaging device, or an electronic device having a novel configuration as one of the problems. One aspect of the present invention is to reduce at least one of the problems of the prior art as one of the problems.

[0008] Note that the description of these problems does not prevent the existence of other problems. Note that one aspect of the present invention does not need to solve all of these problems. Note that other problems can be extracted from the descriptions in the specification, drawings, claims, etc.

Means for Solving the Problems

[0009] One aspect of the present invention is a display device including a first to third switches, a first transistor, a second transistor, and a light emitting and receiving element. The first switch is electrically connected to the gate of the first transistor. The second switch is located between one of the source and drain of the first transistor and one electrode of the light emitting and receiving element. The third switch is located between one electrode of the light emitting and receiving element and the gate of the second transistor. A first potential is applied to the other of the source and drain of the first transistor. A second potential is applied to the other electrode of the light emitting and receiving element. The light emitting and receiving element has a function of emitting light of a first color and a function of receiving light of a second color.

[0010] Also, in the above, during the period when a potential is supplied to the gate of the first transistor, it is preferable that the first switch is in a conductive state and the second switch is in a conductive state or a non-conductive state. Also, during the period when the light emitting and receiving element emits light, it is preferable that the second switch is in a conductive state. Also, during the period when the light emitting and receiving element receives light, it is preferable that the second switch is in a non-conductive state and the third switch is in a non-conductive state. Also, during the period when charge is transferred from the light emitting and receiving element to the gate of the second transistor, it is preferable that the second switch is in a non-conductive state and the third switch is in a conductive state.

[0011] Another aspect of the present invention is a display device having pixels, a first wiring, and a second wiring. The pixel has a first sub-pixel. The first sub-pixel has first to seventh transistors and a light-emitting and light-receiving element. One of the source and drain of the first transistor is supplied with a first potential, and the other of the source and drain is electrically connected to one of the source and drain of the fourth transistor. One of the source and drain of the third transistor is electrically connected to the first wiring, and the other of the source and drain is electrically connected to the gate of the first transistor. The other of the source and drain of the fourth transistor is electrically connected to one electrode of the light-emitting and light-receiving element and one of the source and drain of the fifth transistor. The other of the source and drain of the fifth transistor is electrically connected to one of the source and drain of the sixth transistor and the gate of the second transistor. One of the source and drain of the second transistor is electrically connected to one of the source and drain of the seventh transistor. The other of the source and drain of the seventh transistor is electrically connected to the second wiring. A second potential is applied to the other electrode of the light-emitting and light-receiving element. Further, the light-emitting and light-receiving element has a function of emitting light of a first color and a function of receiving light of a second color.

[0012] Also, in the above, it is preferable that the fourth transistor is controlled so as to be in a conductive state during the period when the light-emitting and light-receiving element emits light, and to be in a non-conductive state during the period when the light-emitting and light-receiving element receives light and during the period when charge is transferred from the light-emitting and light-receiving element to the gate of the second transistor via the fifth transistor.

[0013] Also, in the above, it is preferable to further include an eighth transistor, a first capacitor, and a third wiring. At this time, it is preferable that one of the source and drain of the eighth transistor is electrically connected to the third wiring, and the other of the source and drain is electrically connected to one electrode of the first capacitor and the other of the source and drain of the first transistor. Also, it is preferable that the other electrode of the first capacitor is electrically connected to the gate of the first transistor.

[0014] Alternatively, in the above, it is preferable to further include a ninth transistor, a tenth transistor, a second capacitor, and a fourth wiring. At this time, for the ninth transistor, it is preferable that one of the source and the drain is electrically connected to the fourth wiring, and the other of the source and the drain is electrically connected to one electrode of the second capacitor and one of the source and the drain of the tenth transistor. Also, for the second capacitor, it is preferable that the other electrode is electrically connected to the gate of the first transistor. Further, for the tenth transistor, it is preferable that the other of the source and the drain is electrically connected to the other of the source and the drain of the first transistor.

[0015] Also, in the above, it is preferable that the first wiring is supplied with the first data potential during the first period. Further, it is preferable that the fourth wiring is supplied with a reset potential during the first period and the second data during the second period.

[0016] Also, in any of the above, it is preferable that a third potential is applied to the other of the source and the drain of the sixth transistor. At this time, it is preferable that the first potential is higher than the second potential, and the third potential is lower than the second potential.

[0017] Also, in any of the above, it is preferable that the pixel has a second sub-pixel having a light-emitting element. At this time, it is preferable that the light-emitting element has a function of emitting light of a second color.

[0018] Also, in the above, it is preferable that the light-receiving and light-emitting element and the light-emitting element are provided on the same plane.

[0019] Also, in the above, the light-receiving and light-emitting element has an electron injection layer, an electron transport layer, a light-emitting layer, an active layer, a hole injection layer, and a hole transport layer between the pixel electrode and the first electrode, and it is preferable that the light-emitting element has one or more of the first electrode, the electron injection layer, the electron transport layer, the hole injection layer, and the hole transport layer.

[0020] Another aspect of the present invention is a display module having any one of the above display devices and a connector or an integrated circuit.

[0021] Another aspect of the present invention is an electronic device having the above display module and at least one of an antenna, a battery, a housing, a camera, a speaker, a microphone, a touch sensor, and an operation button.

Advantages of the Invention

[0022] According to one aspect of the present invention, a display device having an imaging function can be provided. According to one aspect of the present invention, an imaging device or a display device capable of capturing a high-definition image can be provided. According to one aspect of the present invention, an imaging device or a display device capable of performing high-sensitivity imaging can be provided. According to one aspect of the present invention, an imaging device or a display device in which the influence of noise is suppressed can be provided. According to one aspect of the present invention, a display device capable of acquiring biometric information such as fingerprints can be provided. According to one aspect of the present invention, a display device functioning as a touch panel can be provided.

[0023] Also, according to one aspect of the present invention, the number of parts of an electronic device can be reduced. According to one aspect of the present invention, a display device, an imaging device, or an electronic device having a novel configuration can be provided. According to one aspect of the present invention, at least one of the problems of the prior art can be at least alleviated.

[0024] Note that the description of these effects does not prevent the existence of other effects. Note that one aspect of the present invention does not necessarily have to have all of these effects. Note that other effects can be extracted from the descriptions in the specification, drawings, claims, etc.

Brief Description of the Drawings

[0025]

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Embodiments for Carrying Out the Invention

[0026] Hereinafter, embodiments will be described with reference to the drawings. However, the embodiments can be implemented in many different ways, and it will be easily understood by those skilled in the art that the forms and details can be variously changed without departing from the spirit and its scope. Therefore, the present invention is not to be construed as limited to the description of the following embodiments.

[0027] In the configuration of the invention described below, the same reference numerals are commonly used for the same parts or parts having the same function among different drawings, and the repeated description thereof is omitted. Also, when referring to the same function, the hatch patterns may be the same, and there may be cases where no reference numerals are particularly assigned.

[0028] In each of the drawings described in this specification, the sizes of the respective components, the thicknesses of the layers, or the regions may be exaggerated for clarity. Therefore, it is not necessarily limited to that scale.

[0029] Note that ordinal numbers such as "first" and "second" in this specification and the like are attached to avoid confusion of components and are not numerically limiting.

[0030] A transistor is a type of semiconductor device and can realize functions such as amplifying current or voltage and a switching operation for controlling conduction or non - conduction. The transistors in this specification include IGFET (Insulated Gate Field Effect Transistor) and thin - film transistor (TFT: Thin Film Transistor).

[0031] Also, the functions of "source" and "drain" may be interchanged when transistors of different polarities are adopted or when the direction of current changes in circuit operation. Therefore, in this specification, the terms "source" and "drain" can be used interchangeably.

[0032] Note that in this specification, the EL layer refers to a layer provided between a pair of electrodes of a light - emitting element and containing at least a light - emitting substance (also called a light - emitting layer) or a laminate containing a light - emitting layer.

[0033] In this specification and the like, a display panel, which is an aspect of a display device, has a function of displaying (outputting) an image or the like on a display surface. Therefore, the display panel is an aspect of an output device.

[0034] Also, in this specification and the like, a display panel module, a display module, or simply a display panel may refer to a display panel whose substrate is attached with a connector such as FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package), or a substrate on which an IC is mounted by a method such as COG (Chip On Glass).

[0035] In addition, in this specification and the like, a touch panel, which is an 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 when a detection object such as a finger or a stylus touches, presses, or approaches the display surface. Therefore, the touch panel is an aspect of an input / output device.

[0036] The touch panel can also be referred to as, for example, a display panel (or display device) with a touch sensor, or a display panel (or display device) with a touch sensor function. The touch panel can also be configured to have a display panel and a touch sensor panel. Alternatively, it can be configured to have a function as a touch sensor inside or on the surface of the display panel.

[0037] Also, in this specification and the like, a touch panel substrate on which a connector, an IC, or the like is mounted may be referred to as a touch panel module, a display module, or simply a touch panel.

[0038] (Embodiment 1) In this embodiment, a configuration example and a driving method example of a display device according to an aspect of the present invention will be described.

[0039] [Configuration Example 1] An aspect of the present invention is a display device having a plurality of pixels arranged on a matrix. Each pixel has one or more sub-pixels. Each sub-pixel has one or more light-emitting and light-receiving elements.

[0040] The light-emitting and light-receiving element (also referred to as a light-emitting and light-receiving device) is an element that combines the function of a light-emitting element (also referred to as a light-emitting device) that emits light of a first color and the function of a photoelectric conversion element (also referred to as a photoelectric conversion device) that receives light of a second color. The light-emitting and light-receiving element can also be referred to as a multifunctional element, a multifunctional diode, a light-emitting photodiode, or a bidirectional photodiode.

[0041] By arranging a plurality of sub-pixels each having a light-emitting and light-receiving element in a matrix, the display device can have both a function of displaying an image and a function of imaging. Therefore, the display device can also be called a composite device or a multi-functional device.

[0042] FIG. 1 shows a part of a pixel circuit applicable to a sub-pixel having a light-emitting and light-receiving element. The pixel circuit includes a switch SW1, a switch SW2, a switch SW3, a transistor Tr1, a transistor Tr2, and a light-emitting and light-receiving element ME. Further, the pixel circuit preferably has a capacitor CS1 and a capacitor CS2 as capacitors for holding charges.

[0043] The switch SW1, the switch SW2, and the switch SW3 each have two terminals and are elements capable of controlling conduction and non-conduction between the terminals.

[0044] One terminal of the switch SW1 is electrically connected to the gate of the transistor Tr1 and one electrode of the capacitor CS1. One of the source and drain of the transistor Tr1 is electrically connected to the wiring AL, and the other is electrically connected to one terminal of the switch SW2. The other terminal of the switch SW2 is electrically connected to one electrode of the light-emitting and light-receiving element ME and one terminal of the switch SW3. The other terminal of the switch SW3 is electrically connected to the gate of the transistor Tr2 and one electrode of the capacitor CS2. The other electrode of the light-emitting and light-receiving element ME is electrically connected to the wiring CL.

[0045] It is preferable that a fixed potential is applied to the other electrodes of the capacitors CS1 and CS2. As the fixed potential, a potential VDD, a potential VSS, a ground potential, a reference potential, or a common potential can be used.

[0046] In FIG. 1, the anode of the light emitting and receiving element ME is configured to be located on the switch SW2 side. At this time, the potential applied to the wiring CL can be set lower than the potential applied to the wiring AL. Note that the cathode of the light emitting and receiving element ME may be configured to be located on the switch SW2 side. In this case, the wiring CL may be configured to have a potential higher than that of the wiring AL.

[0047] Also, in FIG. 1 and the like, an example in which an n-channel type transistor is used as the transistor is shown, but a p-channel type transistor can also be applied to part or all of them. At this time, various potentials, signals, etc. described below may be appropriately changed according to the change of the transistor.

[0048] The transistor Tr1 has a function of controlling the current flowing through the light emitting and receiving element ME. The transistor Tr1 can control the current flowing through the light emitting and receiving element ME according to the potential applied to the gate via the switch SW1. The light emitting and receiving element ME can emit light with a luminance corresponding to the current.

[0049] Charge (potential) is transferred from the light emitting and receiving element ME to the node to which the gate of the transistor Tr2 is connected via the switch SW3. The conduction state of the transistor Tr2 changes according to the potential. The transistor Tr2 functions as a transistor for reading.

[0050] Hereinafter, an example of the operation method of the circuit illustrated in FIG. 1 will be described.

[0051] FIG. 2A shows the operation during the period of writing the data potential to the gate of the transistor Tr1 (data writing period). During the data writing period, the switch SW1 and the switch SW2 are turned on, and the switch SW3 is turned off. Thereby, the data potential is supplied to the gate of the transistor Tr1 via the switch SW1. At this time, the capacitor CS1 is charged.

[0052] FIG. 2B shows the operation during the period (holding and light-emitting period) in which the gate potential of transistor Tr1 is held and the light-emitting element ME emits light according to the current flowing through transistor Tr1. During the holding and light-emitting period, switch SW1 and switch SW3 are turned off, and switch SW2 is turned on. As a result, the current flowing through transistor Tr1 flows through switch SW2 to light-emitting element ME. In FIG. 2B, the current path is indicated by a dashed arrow.

[0053] By turning off switch SW3 during the data writing period and the holding and light-emitting period, the light-emitting element ME and transistor Tr2 can be electrically insulated from each other.

[0054] FIG. 2C shows the operation during the period (exposure period) in which the light-emitting element ME receives light and charges are accumulated in the light-emitting element. During the exposure period, charges are accumulated at both ends of the light-emitting element ME, causing the potential difference Vc between the anode and cathode of the light-emitting element ME to change.

[0055] During the exposure period, all of switch SW1, switch SW2, and switch SW3 are turned off. As a result, the light-emitting element ME is electrically insulated from both transistor Tr1 and transistor Tr2. Therefore, it is possible to prevent the charges accumulated on the anode side of the light-emitting element ME from flowing out to the transistor Tr1 and transistor Tr2 sides. As a result, high-precision imaging can be performed.

[0056] Note that switch SW1 may be turned on during the exposure period. At this time, data potential writing may be performed during the exposure period. That is, a period in which exposure and data writing are performed simultaneously may be provided.

[0057] FIG. 2D shows the operation during the period (transfer period) in which the charge accumulated in the light-emitting and light-receiving element ME is transferred to the node to which the gate of the transistor Tr2 is connected. During the transfer period, the switch SW1 and the switch SW2 are set to the non-conductive state, and the switch SW3 is set to the conductive state. Thereby, the charge accumulated in the light-emitting and light-receiving element ME is transferred to the node to which the gate of the transistor Tr2 is connected via the switch SW3. After the transfer of the charge is completed, by setting the switch SW3 to the non-conductive state, the potential of the gate of the transistor Tr2 is held.

[0058] During the transfer period, by setting the switch SW2 to the non-conductive state, the light-emitting and light-receiving element ME and the transistor Tr1 can be electrically insulated. At this time, as shown in FIG. 2D, it is possible to prevent a current from flowing from the wiring AL through the transistor Tr1, the switch SW2, and the switch SW3 to the node to which the gate of the transistor Tr2 is connected. In particular, when a data potential is held at the gate of the transistor Tr1 and the transistor Tr1 is in the conductive state, by setting the switch SW2 to the non-conductive state, it is possible to preferably prevent charge from flowing into the gate of the transistor Tr2 from the wiring AL.

[0059] Here, during the exposure period and the transfer period, it is preferable that a data potential is held at the gate of the transistor Tr1. Thereby, after the transfer period ends, by switching the switch SW2 from the non-conductive state to the conductive state, the light-emitting and light-receiving element ME can be immediately caused to emit light without newly writing data. Thereby, since there is no period (non-display period) during which the image is not displayed between the completion of the transfer period and the display of the image, it is possible to prevent the display quality from being impaired.

[0060] In this way, switch SW2 is controlled to be in a conductive state during the period when the image is displayed and in a non-conductive state during the period when imaging is performed (exposure period and transfer period). That is to say, switch SW2 can also be referred to as a switch for switching between image display and imaging. By providing switch SW2 between transistor Tr1 and light-emitting and receiving element ME, the function of light-emitting and receiving element ME can be clearly switched.

[0061] [Configuration Example 2] Hereinafter, a more specific configuration example of the display device according to one aspect of the present invention will be described.

[0062] FIG. 3A shows a block diagram for explaining the configuration of display device 10. Display device 10 includes a display unit 11, a drive circuit unit 12, a drive circuit unit 13, a drive circuit unit 14, a circuit unit 15, and the like.

[0063] Display unit 11 has a plurality of pixels 30 arranged in a matrix. Pixel 30 has a sub-pixel 20R, a sub-pixel 20G, and a sub-pixel 20B. Sub-pixel 20R has a light-emitting and receiving element, and sub-pixels 20G and 20B each have a light-emitting element.

[0064] Wiring SL1, wiring GL, wiring RS, wiring SE, wiring WX, etc. are electrically connected to sub-pixel 20R. Wiring SL2 and wiring GL, etc. are electrically connected to sub-pixel 20G. Wiring SL3 and wiring GL, etc. are electrically connected to sub-pixel 20B.

[0065] Wiring SL1, wiring SL2, and wiring SL3 are each electrically connected to the drive circuit section 12. Wiring GL is electrically connected to the drive circuit section 13. Wiring RS and wiring SE are each electrically connected to the drive circuit section 14. Wiring WX is electrically connected to the circuit section 15. The drive circuit section 12 functions as a source line drive circuit (also referred to as a source driver) and supplies a data signal (data potential) to each sub-pixel via the wiring SL1, the wiring SL2, and the wiring SL3. The drive circuit section 13 functions as a gate line drive circuit (also referred to as a gate driver) and supplies a selection signal to the wiring GL.

[0066] The drive circuit section 14 has a function of generating a signal for supplying to the sub-pixel 20R and outputting it to the wiring SE, the wiring RS, etc. Further, the drive circuit section 14 has a function of generating and outputting a signal for supplying to the wiring REN and the wiring TX, which will be described later. Note that the drive circuit section 13 or the drive circuit section 12 may have a function of generating a signal to be supplied to one or both of the wiring REN and the wiring TX. The circuit section 15 has a function of receiving a signal output from the sub-pixel 20R via the wiring WX and outputting it to the outside as imaging data. The circuit section 15 functions as a readout circuit.

[0067] 〔Example of pixel configuration〕 FIG. 3B shows an example of a circuit diagram of the sub-pixel 20R. The sub-pixel 20R includes a circuit 21R, a circuit 22, and a light-emitting and receiving element MER. The circuit 21R includes transistors M1 to M3, a transistor M10, and a capacitor C1. The circuit 22 includes transistors M11 to M14 and a capacitor C2.

[0068] When the light-emitting and receiving element MER is used as a light-emitting element, the circuit 21R functions as a circuit for controlling the light emission of the light-emitting and receiving element MER. The circuit 21R has a function of controlling the current flowing through the light-emitting and receiving element MER according to the value of the data potential supplied from the wiring SL1.

[0069] Further, when the transceiver element MER is used as a light-receiving element, the circuit 22 functions as a sensor circuit for controlling the operation of the transceiver element MER. The circuit 22 has functions such as applying a reverse bias voltage to the transceiver element MER, controlling the exposure period of the transceiver element MER, holding a potential based on the charge transferred from the transceiver element MER, and outputting a signal based on the potential to the wiring WX.

[0070] The transistor M1 has its gate electrically connected to the wiring GL, one of its source and drain electrically connected to the wiring SL1, and the other electrically connected to the gate of the transistor M2 and one electrode of the capacitor C1. The transistor M2 has one of its source and drain electrically connected to the wiring AL, and the other electrically connected to one of the source and drain of the transistor M10, the other of the source and drain of the transistor M3, and the other electrode of the capacitor C1. The transistor M3 has its gate electrically connected to the wiring GL, and one of its source and drain electrically connected to the wiring V0L. The transistor M10 has its gate electrically connected to the wiring REN, and the other of its source and drain electrically connected to one electrode of the transceiver element MER. The other electrode of the transceiver element MER is electrically connected to the wiring CL.

[0071] A data potential is applied to the wiring SL1. A fixed potential is applied to the wiring V0L. An anode potential is applied to the wiring AL. A cathode potential is applied to the wiring CL. In the configuration shown in FIG. 3B, the anode potential is set to a potential higher than the cathode potential. A signal for controlling the conduction and non-conduction of the transistor M10 is applied to the wiring REN.

[0072] The gate of transistor M11 is electrically connected to wiring TX, one of the source and drain is electrically connected to one electrode of the light-emitting and receiving element MER, and the other is electrically connected to the gate of transistor M13, one of the source and drain of transistor M12, and one electrode of capacitor C2. The gate of transistor M12 is electrically connected to wiring RS, and the other of the source and drain is electrically connected to wiring VRS. The other electrode of capacitor C2 is electrically connected to wiring VCP. One of the source and drain of transistor M13 is electrically connected to wiring VPI, and the other is electrically connected to one of the source and drain of transistor M14. The gate of transistor M14 is electrically connected to wiring SE, and the other of the source and drain is electrically connected to wiring WX.

[0073] A signal for controlling the conduction and non-conduction of transistor M11 is applied to wiring TX. A fixed potential is applied to wiring VCP. A reset potential is applied to wiring VRS. A fixed potential is applied to wiring VPI. In the configuration shown in FIG. 3B, it is preferable that the reset potential applied to wiring VRS is lower than the cathode potential applied to wiring CL.

[0074] Here, transistor M10 corresponds to switch SW2 in the above configuration example 1 and FIG. 1, transistor M2 corresponds to transistor Tr1, transistor M13 corresponds to transistor Tr2, transistor M1 corresponds to switch SW1, and transistor M11 corresponds to switch SW3.

[0075] Here, for the transistors M1, M3, M10, M11, M12, and M14 that function as switches, it is preferable to apply transistors with an extremely small leakage current in the non-conducting state. In particular, transistors using an oxide semiconductor for the semiconductor layer where the channel is formed can be preferably used. Also, by applying transistors using an oxide semiconductor to transistors M2 and M13 as well, all the transistors can be formed through a common manufacturing process, which is preferable. Note that for one or both of transistors M2 and M13, silicon (including amorphous silicon, polycrystalline silicon, and single-crystalline silicon) may be applied to the semiconductor layer where the channel is formed. Note that this is not limited thereto, and transistors using silicon can also be used for some or all of the transistors. Also, for some or all of the transistors, transistors using an inorganic semiconductor, compound semiconductor, organic semiconductor, etc. other than silicon may be used.

[0076] FIG. 4 shows an example of a circuit diagram of a pixel 30 having sub-pixels 20R, 20G, and 20B.

[0077] The sub-pixel 20G includes a circuit 21G and a light-emitting element ELG. The sub-pixel 20B includes a circuit 21B and a light-emitting element ELB.

[0078] The circuits 21G and 21B have the same configuration as the circuit 21R of the sub-pixel 20R, except that they do not have the transistor M10. In the circuits 21G and 21B, for the transistor M2, the other of the source and drain is electrically connected to one of the electrodes of the light-emitting element ELG or the light-emitting element ELB.

[0079] For example, in pixel 30, the light-emitting and light-receiving element MER is an element that emits red light and receives green or blue light, the light-emitting element ELG is an element that emits green light, and the light-emitting element ELB is an element that emits blue light. That is, the light-emitting and light-receiving element MER preferably functions as a photoelectric conversion element that receives light emitted by either one or both of the light-emitting element ELG and the light-emitting element ELB. Thereby, when imaging a fingerprint or the like with the light-emitting and light-receiving element MER, either one or both of the light-emitting element ELG and the light-emitting element ELB can be used as a light source. For example, the light emitted from the light-emitting element ELG or the light-emitting element ELB is reflected by an object to be imaged such as a finger, and the reflected light is detected by the light-emitting and light-receiving element MER, so that a clear image of the object to be imaged can be captured.

[0080] Here, as shown in FIG. 5A, a configuration in which a transistor having a back gate is applied to each transistor may be used. In FIG. 5A, a pair of gates (a gate and a back gate) are electrically connected.

[0081] Note that, in FIG. 5A, all the transistors are configured such that a pair of gates are electrically connected, but the present invention is not limited to this. The pixel 30 may have a transistor that connects one of the pair of gates to another wiring. For example, by connecting one of the pair of gates to a wiring to which a fixed potential is applied, the stability of the electrical characteristics can be improved. Also, one of the pair of gates may be connected to a wiring to which a potential for controlling the threshold voltage of the transistor is applied. Further, as shown in FIG. 5B, a transistor in which one of the pair of gates is connected to one of the source and the drain may be used. At this time, it is preferable to connect one of the gates to the source. For example, the transistors shown in FIG. 5B can be preferably used for the transistors M2, M12, and M13 in the pixel 30.

[0082] Also, although an example where all transistors have a back gate has been shown here, the present invention is not limited to this, and transistors with a back gate and transistors without a back gate may be mixed.

[0083] [Configuration Example 3] Hereinafter, a configuration example of a display device having pixels with a configuration partially different from the above will be described.

[0084] The pixels exemplified below are pixels that can emit light from a light-emitting and receiving element and a light-emitting element using two types of data potentials. For example, gradation correction can be performed with one of the data potentials. Further, the pixels exemplified below can generate a potential exceeding the maximum potential that can be supplied by a source driver circuit that supplies two data potentials within the pixel. As a result, since the power supply voltage of the source driver circuit can be reduced to a low voltage, the power consumption of the source driver circuit can be reduced.

[0085] [Configuration Example 3-1] FIG. 6 shows a circuit diagram of pixel 30a. Pixel 30a has sub-pixels 20aR, sub-pixels 20aG, and sub-pixels 20aB. Further, wiring GL1 and wiring GL2 are connected to pixel 30a in place of wiring GL. Further, wiring VL1, wiring VL2, and wiring VL3 are connected to pixel 30a. Wiring GL1 and wiring GL2 are electrically connected to the drive circuit unit 13. Further, wiring VL1, wiring VL2, and wiring VL3 are electrically connected to the drive circuit unit 12.

[0086] Sub-pixel 20aR has circuit 21aR, circuit 22, and light-emitting and receiving element MER. Since circuit 22 has the same configuration as sub-pixel 20R described above, the above can be incorporated by reference.

[0087] Circuit 21aR has transistor M4 and capacitor C3 in addition to circuit 21R described above. Similarly, circuit 21aG and circuit 21aB also have transistor M4 and capacitor C3.

[0088] Transistor M4 has its gate electrically connected to wiring GL2, one of its source and drain electrically connected to wiring VL1, and the other electrically connected to one of the source and drain of transistor M3 and the other electrode of capacitor C3. One electrode of capacitor C3 is electrically connected to the other of the source and drain of transistor M1, the gate of transistor M2, and one electrode of capacitor C1. The gates of transistor M1 and transistor M3 are electrically connected to wiring GL1 respectively.

[0089] In circuit 21aG, one of the source and drain of transistor M4 is electrically connected to wiring VL2. Also, in circuit 21aB, one of the source and drain of transistor M4 is electrically connected to wiring VL3.

[0090] Different selection signals are applied to wiring GL1 and wiring GL2 respectively. The first data potential D R is applied to wiring SL1. Also, the second data potential W R and the reset potential V0 are applied to wiring VL1 in different periods. Similarly, the first data potential D G is applied to wiring SL2, and the second data potential W G and the reset potential V0 are applied to wiring VL2. Also, the first data potential D B is applied to wiring SL3, and the second data potential W B and the reset potential V0 are applied to wiring VL3.

[0091] Taking circuit 21aR as an example, an example of the data writing operation will be described. Note that circuits 21aG and 21aB can also be driven in the same way. In the following, for simplicity of explanation, the influence of the threshold voltage of each transistor and the capacitance components of the transistors and wirings are not considered in the explanation.

[0092] First, turn on transistor M1, transistor M3, and transistor M4, and apply the first data potential D from wiring SL1 RSupply the reset potential V0 from the wiring VL1, respectively. As a result, the gate potential of the transistor M2 becomes the potential D R and the voltages D R -V0 are charged to the capacitors C1 and C3. Subsequently, turn off the transistors M1 and M3, turn on the transistor M4, and supply the second data potential W R from the wiring VL1. At this time, since the node to which the gate of the transistor M2 is connected is in a floating state, as the potential of the other electrode of the capacitor C3 changes from the potential V0 to the potential W R , the potential of the gate of the transistor M2 changes. For example, when the potential W R is higher than the potential V0, the potential of the gate of the transistor M2 rises.

[0093] In this way, the circuit 21aR can generate the potential of the gate of the transistor M2 using two data potentials. Similarly, the circuits 21aG and 21aB can also generate the gate potential of the transistor M2 using two data potentials.

[0094] Also, by supplying the first data potential D R and the reset potential V0 during the same period, the voltage between the gate and source of the transistor M2 can be determined regardless of the electrical characteristics of the light-emitting or light-receiving element. As a result, high-quality display can be realized.

[0095] Here, as shown in FIG. 7, a configuration in which transistors having back gates are applied to each transistor may be adopted. In FIG. 7, a pair of gates are electrically connected. Also, the transistor illustrated in FIG. 5B may be applied to the transistor M2 or the like of the pixel 30a.

[0096] Also, although an example in which all transistors have back gates is shown here, the present invention is not limited to this, and transistors having back gates and transistors not having back gates may be mixed.

[0097] [Configuration Example 3-2] In the above, an example in which one pixel has three sub-pixels has been shown. Hereinafter, an example in which one pixel has two sub-pixels will be described.

[0098] FIG. 8A shows an example of an arrangement method for 3×3 pixels. In FIG. 8A, pixels from the i-th row and j-th column (where i and j are each independently an integer of 1 or more) to the (i + 2)-th row and (j + 2)-th column are shown.

[0099] In FIG. 8A, pixel 30G and pixel 30B are alternately arranged in the row direction and the column direction. Pixel 30G has sub-pixel 20aR and sub-pixel 20aG. Pixel 30B has sub-pixel 20aR and sub-pixel 20aB.

[0100] For example, to the pixel 30G located at the i-th row and j-th column, wiring GL1[i], wiring GL2[i], wiring RS[i], and wiring SE[i] extending in the row direction, and wiring SL1[j], wiring SL2[j], wiring VL1[j], wiring VL2[j], and wiring WX[j] extending in the column direction are connected.

[0101] Note that, instead of sub-pixel 20aR, sub-pixel 20aG, and sub-pixel 20aB, sub-pixel 20R, sub-pixel 20G, and sub-pixel 20B exemplified in the above Configuration Example 2 can also be applied. At this time, a configuration in which wirings such as wiring GL2, wiring VL1, and wiring VL2 are omitted may be adopted.

[0102] FIG. 8B shows an example of an arrangement method for light emitting and receiving element MER, light emitting element ELG, and light emitting element ELB. Light emitting and receiving element MER is arranged at equal intervals in the row direction and the column direction. Also, light emitting element ELG and light emitting element ELB are alternately arranged in the row direction and the column direction, respectively. Further, the shape of each of light emitting and receiving element MER, light emitting element ELG, and light emitting element ELB is a shape in which a square is inclined by about 45 degrees with respect to the arrangement direction. Thereby, the distance between adjacent elements can be increased, and when manufacturing the light emitting element and the light emitting and receiving element separately, they can be manufactured with a good yield.

[0103] FIG. 9 shows an example of a circuit diagram for the pixel 30G at the i-th row and j-th column and the pixel 30B at the (i + 1)-th row and j-th column. Regarding the configurations of the sub-pixels 20aR, 20aG, and 20aB, the above configuration example 3-1 can be applied.

[0104] [Example of driving method] Hereinafter, an example of a driving method for a display device will be described. Here, a configuration in which one pixel has two sub-pixels, as exemplified in the above configuration example 3-2, will be described as an example.

[0105] Hereinafter, as the display device, a display device having a configuration in which a plurality of pixels are arranged in a matrix in M rows and N columns (M and N are each independently an integer of 2 or more) in a display unit will be used.

[0106] FIGS. 10 and 11 schematically show the operation of the display device. The operation of the display device is roughly divided into a period (display period) in which an image is displayed using a light-emitting element and a light-emitting and receiving element, and a period (imaging period) in which imaging is performed using a light-emitting and receiving element (also referred to as a sensor). The display period is a period in which image data is written to the pixel and display based on the image data is performed. The imaging period is a period in which imaging by the light-emitting and receiving element and reading of imaging data are performed.

[0107] First, the operation in the display period will be described with reference to FIG. 10.

[0108] In the display period, the operation of writing data to the pixel is repeatedly performed. During that period, it is assumed that the operation of the sensor is not performed (denoted as blank). Note that imaging operation can also be performed during the display period.

[0109] In one write operation, image data for one frame is written. As shown in FIG. 10, in one write operation (denoted as write), data is sequentially written to the pixels from the first column to the M-th column.

[0110] Figure 10 shows a timing chart for the writing operations of the data in the i-th row and the (i + 1)-th row. Here, it shows the potential transitions in wiring GL1[i], wiring GL2[i], wiring GL1[i + 1], wiring GL2[i + 1], wiring REN, wiring SL1[j], wiring VL1[j], wiring SL2[j], and wiring VL2[j]. Regarding the connection relationship between each wiring and each pixel, Figure 9 can be referred to.

[0111] The data writing period for one row is divided into two periods. Specifically, there is a period for writing the first data potential D R etc. (referred to as video writing), and a period for writing the second data potential W R etc. (referred to as weight writing).

[0112] During the video writing (video writing [i]) period of the i-th row, wiring GL1[i], wiring GL2[i], and wiring REN are set to high-level potentials. Also, the first data potential D R [i, j] is given to wiring SL1[j], and the first data potential D G [i, j] is given to wiring SL2[j] respectively. Also, a reset potential V0 is given to wiring VL1[j] and wiring VL2[j]. As a result, the first data potential D R [i, j] is written to the sub-pixel 20aR of the pixel 30G located at the i-th row and j-th column, and the first data potential D G [i, j] is written to the sub-pixel 20aG respectively.

[0113] Subsequently, during the weight writing [i] period, wiring GL1[i] becomes a low-level potential. Also, the second data potential W R [i, j] is given to wiring VL1[j], and the second data potential W G [i, j] is given to wiring VL2[j] respectively. As a result, in the sub-pixel 20aR[i, j] of the pixel 30G located at the i-th row and j-th column, a potential generated by the first data potential D R [i, j] and the second data potential W R [i, j] is written. Similarly, in the sub-pixel 20aG[i, j], the first data potential D GThe potential generated by [i,j] and the second data potential W G is written into the state where the potential generated by [i,j] and [i,j] is written.

[0114] Thus, the writing operation of the data in the i-th row is completed.

[0115] Subsequently, the writing operation of the data in the (i + 1)-th row is performed. For the (i + 1)-th row, by performing the same operation as the above i-th row, in the sub-pixel 20aR[i + 1,j] of the pixel 30B located at the (i + 1)-th row and j-th column, the first data potential D R [i + 1,j] and the second data potential W R is written into the state where the potential generated by [i + 1,j] and [i + 1,j] is written. Similarly, in the sub-pixel 20aB[i + 1,j], the first data potential D G [i + 1,j] and the second data potential W G is written into the state where the potential generated by [i + 1,j] and [i + 1,j] is written.

[0116] In this way, by providing two periods, namely the video writing period and the weight writing period, two types of data can be written for each sub-pixel. As a result, tone correction or luminance correction can be performed. Also, the display with two types of images superimposed can be easily performed.

[0117] Subsequently, the operation during the imaging period will be described with reference to FIG. 11. Here, the case of performing the imaging operation in the global shutter method will be described. Note that the present invention is not limited to the global shutter method, and the driving method of the rolling shutter method can also be applied.

[0118] The imaging period is divided into a period in which imaging is performed simultaneously for each pixel (referred to as imaging. Hereinafter, it is also referred to as the imaging operation period to distinguish it from the imaging period) and a period in which imaging data is read out sequentially for each row (referred to as readout). The imaging operation period is divided into an initialization period, an exposure period, and a transfer period. Also, in the readout period, the imaging data is read out for each row from the first row to the M-th row.

[0119] FIG. 11 shows a timing chart during the imaging operation period and the readout period. Here, for the wiring TX, wiring SE[i], wiring RS[i], wiring SE[i + 1], wiring RS[i + 1], wiring WX[1:N], wiring GL1[1:M], wiring GL2[1:M], wiring REN, wiring SL[1:N], and wiring VL[1:N], the potential transitions are shown. Here, for the wiring WX, the wirings from the first column to the Nth column are collectively denoted as wiring WX[1:N]. Similarly, the wiring GL1 is collectively denoted as wiring GL[1:M], and the wiring GL2 is collectively denoted as wiring GL[1:M]. Also, for the wiring SL1, wiring SL2, etc., they are collectively denoted as wiring SL[1:N], and for the wiring VL1, wiring VL2, etc., they are collectively denoted as wiring VL[1:N].

[0120] During the initialization period, the wiring REN is set to a low-level potential. As a result, in all pixels, the transistor M10 becomes non-conductive.

[0121] By setting the wiring TX, wiring RS[i], and wiring RS[i + 1] to a high-level potential, a predetermined potential is applied from the wiring VRS to one of the node to which the gate of the transistor M13 is connected and the light-emitting and receiving element MER. Thereby, the reset operation of all pixels is performed.

[0122] Subsequently, during the exposure period, the wiring TX, wiring RS[i], and wiring RS[i + 1] are set to a low-level potential. As a result, charges are accumulated in the light-emitting and receiving element MER.

[0123] Subsequently, during the transfer period, the wiring TX is set to a high-level potential. Thereby, the charges accumulated in the light-emitting and receiving element MER can be transferred to the node to which the gate of the transistor M13 is connected. Then, by setting the wiring TX to a low-level potential, the potential of the said node is maintained.

[0124] Subsequently, imaging data is read out row by row. During the read period, high-level potentials are sequentially applied from wiring SE[1] to wiring SE[N], enabling data to be read out for all pixels. For example, during the read of the i-th row, by setting wiring SE[i] to a high-level potential, the data D W [i] of the i-th row is output to wiring WX[1:N]. Specifically, for a single wiring WX[j], the data D W [i,j] of the i-th row and j-th column is output.

[0125] Here, during the imaging period, a low-level potential is constantly applied to wiring REN. As a result, particularly during the exposure period and the transfer period, the light-emitting and receiving element MER and the transistor M2 are electrically insulated. This reduces noise and enables high-precision imaging.

[0126] Also, during the imaging period, each pixel preferably maintains the state of holding the image data written immediately before (referred to as holding). Thus, when the imaging period ends and the potential of wiring REN changes from a low-level potential to a high-level potential, an image corresponding to the immediately held image data can be displayed. Further, by holding the image data written in sub-pixel 20aG or sub-pixel 20aB during the imaging period, crosstalk noise to the anode of the light-emitting and receiving element MER in sub-pixel 20aR can be reduced.

[0127] The above is the explanation of the example driving method.

[0128] [Example configuration of the driving circuit] Hereinafter, a circuit applicable to a source driver will be described. In particular, a circuit that can be preferably used for the source driver of a display device having pixels to which two types of data potentials are input, as exemplified in Configuration Example 3 above, will be described.

[0129] FIG. 12 shows a circuit diagram of circuit 40. Circuit 40 has a plurality of circuits 40a. Circuit 40a is a circuit that functions as a so-called demultiplexer that distributes and outputs one input signal to a plurality of wirings. Circuit 40 can be configured to include the same number of circuits 40a as the number of sub-pixels arranged in the column direction. In FIG. 12, two circuits 40a are shown as an example.

[0130] Circuit 40a has transistors 41, 42, and 43. Further, wiring V0L, wiring SE1, and wiring SE2 are connected to circuit 40a. Further, wiring S1[j] is connected to circuit 40a as an input wiring, and wiring SL1[j] and wiring VL1[j] are connected to circuit 40a as output wirings, respectively. In FIG. 12, circuits 40a to which wiring S2[j], wiring SL2[j], and wiring VL2[j] are connected are also shown side by side.

[0131] The gate of transistor 41 is electrically connected to wiring SE1, one of the source and drain is electrically connected to wiring S1[j], and the other is electrically connected to wiring SL1[j]. The gate of transistor 42 is electrically connected to wiring SE2, one of the source and drain is electrically connected to wiring S1[j], and the other is electrically connected to wiring VL1[j]. The gate of transistor 43 is electrically connected to wiring SE1, one of the source and drain is electrically connected to wiring V0L, and the other is electrically connected to wiring VL1[j].

[0132] Signals with different high-level potential periods are applied to wiring SE1 and wiring SE2. A reset potential V0 is applied to wiring V0L.

[0133] When wiring SE1 is at a high level potential and wiring SE2 is at a low level potential, transistor 41 becomes conductive, and the data potential (first data potential) input from wiring S1[j] is output to wiring SL1[j]. On the other hand, since transistor 42 is non-conductive and transistor 43 is conductive, the reset potential V0 is output from wiring V0L to wiring VL1[j].

[0134] When the wiring SE1 is at a low level potential and the wiring SE2 is at a high level potential, the transistor 42 is in a conducting state and the transistor 43 is in a non-conducting state. Therefore, the data potential (second data potential) input from the wiring S1[j] is output to the wiring VL1[j]. On the other hand, since the transistor 41 is in a non-conducting state, the wiring SL1[j] is in an electrically floating state.

[0135] The circuit 40a can alternately select the wiring SL1[j] and the wiring VL1[j] and output the signal from the wiring S1[j] in a time-division manner. Further, the wiring VL1[j] can alternately output the second data potential and the reset potential.

[0136] Here, when the wiring SL1[j] is in a non-selected state, the reset potential V0 may be supplied in the same manner as the wiring VL1[j]. By making the wiring SL1[j] in an electrically floating state when it is in a non-selected state, the previous potential is held. As a result, when the wiring SL1[j] then becomes in a selected state and a data potential is applied from the wiring S1[j], the charging and discharging time of the wiring SL1[j] can be shortened compared to when the potential of the wiring SL1[j] is the reset potential (low level potential). Thereby, it becomes possible to display an image at a high frame frequency.

[0137] By applying such a circuit 40 to a source driver, the number of signal lines can be reduced, and thus the configuration of the display device can be simplified.

[0138] [Configuration example of readout circuit] Hereinafter, an example of a circuit that can be used as a readout circuit will be described. The circuits exemplified below can be applied to, for example, the circuit unit 15 exemplified in FIG. 3A.

[0139] FIG. 13A shows a block diagram of a circuit 50. The circuit 50 includes a plurality of circuits 51, a plurality of circuits 52, a circuit 53, a circuit 54, and a circuit 55.

[0140] In circuit 50, signals from the wiring WX[K:K + p] (where K is an integer from 1 to N) are input, starting from the K-th to the K + p-th. One circuit 50 can input signals from a number of wiring WX obtained by dividing the number of pixels (N) arranged in the row direction by an arbitrary integer x. That is, p is an integer satisfying N / x - 1, and circuit 50 receives signals from N / x pieces of wiring WX. At this time, the display device can be configured to have x circuits 50 as readout circuits. When N is not a multiple of x, the number of signals from the wiring WX input to one circuit 50 can be adjusted as appropriate.

[0141] Circuit 51 is a circuit that converts the current output to one of the wiring WX into a voltage and outputs it. As circuit 51, a circuit that constitutes the transistor M13 of the pixel and the source follower circuit described above can be used.

[0142] Circuit 52 can preferably use a correlated double sampling (CDS) circuit. Circuit 52 can generate a signal with reduced noise.

[0143] Circuit 53 can use a multiplexer circuit. Circuit 53 can convert parallel signals input from a plurality of circuits 52 into serial signals and output them to circuit 54.

[0144] Circuit 54 can use a source follower circuit. Circuit 54 has a function of amplifying and outputting the signal input from circuit 53.

[0145] Circuit 55 can use an analog-to-digital conversion circuit. Circuit 55 has a function of converting the analog signal input from circuit 54 into a digital signal, signal S OUT and outputting it.

[0146] FIG. 13B shows an example of a more specific circuit diagram of circuit 50. In FIG. 13B, circuit 51[j], circuit 52[j] connected to the j-th wiring WX[j], a part of circuit 53, circuit 54, circuit 55, and circuit 56 are shown. Regarding circuit 53, a part of the configuration connected to circuit 52[j] is shown as circuit 53[j]. Circuit 53 has a plurality of circuit 53[j].

[0147] Circuit 51[j] has transistor 61 and transistor 62. Also, wiring IVB and wiring VIV to which a constant potential is supplied are connected to circuit 51[j]. Transistor 62 forms a source follower circuit with transistor M13 of the pixel. Transistor 61 functions as a constant current source. Transistor 61 and transistor 62 form a current mirror.

[0148] Circuit 52[j] has transistors 63 to 68, capacitor 81, and capacitor 82. Also, wiring SEL1, wiring SEL2, and wiring CL to which a signal for controlling the conduction state of the transistor is applied, and wiring VCL, wiring CDB, wiring VDD1, and wiring VSS1 to which a constant potential is applied are connected to circuit 52[j].

[0149] A source follower circuit is formed by transistor 66 and transistor 68. Transistor 67 functions as a constant current source and forms a current mirror with transistor 68. Capacitor 81 is provided between the gate of transistor 66 and the output wiring of circuit 51[j]. The signal given from circuit 51[j] to circuit 52[j] is transmitted to the gate of transistor 66 via capacitor 81.

[0150] Transistor 65 has a function of applying an initial potential to the node to which the gate of transistor 66 is connected. First, the potential of wiring WX[j] is acquired with the initial potential applied from wiring VCL to the node to which the gate of transistor 66 is connected. Then, with transistor 65 in a non-conductive state and further with transistor M12 of the pixel in a conductive state, the potential of wiring WX[j] is acquired. Thereby, a potential corresponding to the difference from the initial potential can be read out as imaging data. By performing such a correlated double sampling operation, a signal with reduced noise can be output from circuit 50.

[0151] Also, transistor 63 has a function of adjusting the capacitance value of the CDS circuit. By bringing transistor 63 into a conductive state, capacitor 81 and capacitor 82 are connected in parallel. Thereby, the sensitivity of the CDS circuit can be improved. On the other hand, by bringing transistor 63 into a non-conductive state, the speed of the read operation can be increased. For example, when imaging an object with low contrast or brightness, the sensitivity can be improved by bringing transistor 63 into a conductive state and increasing the capacitance value of the CDS circuit. On the other hand, when high-speed reading is required, the capacitance value of the CDS circuit can be decreased by bringing transistor 63 into a non-conductive state. These can be switched by the signal applied to wiring SEL1.

[0152] Also, transistor 64 has a function of connecting wiring WX[j] and the node to which the gate of transistor 66 is connected. By bringing transistor 64 into a conductive state, a read operation without using correlated double sampling can be executed. These can be switched by the signal applied to wiring SEL2.

[0153] Circuit 53[j] has a transistor 69, a capacitor 83, and a capacitor 84. Also, a wiring SEL3 for supplying a signal for controlling the conduction state of the transistor and a wiring VDD2 for supplying a fixed potential are connected to the circuit 53[j]. The capacitors 83 and 84 have a function of holding the potential of the wiring. One or both of the capacitors 83 and 84 may be omitted if unnecessary.

[0154] When selecting the circuit 53[j] among the circuits 53, the transistor 69 is set to the conduction state. Thereby, the signal output from the circuit 52[j] can be output to the circuit 54 via the transistor 69. By sequentially selecting the plurality of transistors 69 included in the circuit 53, parallel signals input from the plurality of circuits 52 can be converted into serial signals and output to the circuit 54.

[0155] Circuit 54 has transistors 71 to 74. Also, a wiring SFR for supplying a signal for controlling the conduction state of the transistor, a wiring VRSF, a wiring SFB, a wiring VDD3, and a wiring VSS3 for supplying a fixed potential are connected to the circuit 54.

[0156] The transistor 72 and the transistor 74 constitute a source follower circuit. The transistor 73 functions as a constant current source and constitutes a current mirror with the transistor 74.

[0157] The transistor 71 has a function of resetting the potential of the node to which the gate of the transistor 72 is connected using the potential applied to the wiring VRSF.

[0158] Also, as shown in FIG. 13B, a circuit 56 that functions as an amplifier circuit may be provided between the circuit 54 and the circuit 55. The circuit 56 has a function of amplifying the signal input from the circuit 54 and outputting it to the circuit 55.

[0159] Here, an example is shown in the case where n-channel transistors are applied to all of the transistors constituting circuits 51, 52, 53, and 54. At this time, it is preferable to use transistors in which an oxide semiconductor is applied to the semiconductor layer in which channels are formed for each transistor. In particular, for transistors 63, 64, 65, 69, 71, etc. that function as switches, it is preferable to use transistors with extremely low off-current. Note that the present invention is not limited to this, and transistors in which silicon is applied may be used for some or all of the transistors. Also, p-channel transistors may be applied to some or all of the transistors.

[0160] Further, FIG. 13B shows an example in which transistors in which a pair of gates are electrically connected are applied to all of the transistors constituting circuits 51, 52, 53, and 54. Note that the present invention is not limited to this, and transistors having a single gate may be used for some or all of the transistors. Also, transistors in which one of the gates is electrically connected to one of the source and the drain may be used for some or all of the transistors. Further, transistors to which a constant potential or a signal for controlling the threshold voltage is applied to one of the gates may be used for some or all of the transistors.

[0161] Circuits 51, 52, 53, and 54 are preferably formed on the substrate on which the pixels are provided through the same process as the pixels. Thereby, the number of components of the display device can be reduced, and cost reduction can be achieved. Also, an IC chip may be used for one or both of circuits 56 and 55, or one or both of circuits 56 and 55 may be formed on the substrate on which the pixels are provided.

[0162] The above is the description of the configuration example of the readout circuit.

[0163] The configuration examples illustrated in this embodiment, and the corresponding drawings and the like can be implemented by appropriately combining at least a part thereof with other configuration examples, or drawings and the like.

[0164] This embodiment can be implemented by appropriately combining at least a part thereof with other embodiments described in this specification.

[0165] (Embodiment 2) In this embodiment, a display device according to an aspect of the present invention will be described with reference to FIGS. 14 to 25.

[0166] A display device according to an aspect of the present invention includes a light-emitting element and a light-emitting / receiving element.

[0167] The light-emitting / receiving element can be manufactured by combining an organic EL element, which is a light-emitting element, and an organic photodiode, which is a light-receiving element. For example, a light-emitting / receiving element can be manufactured by adding an active layer of an organic photodiode to the stacked structure of the organic EL element. Furthermore, for a light-emitting / receiving element manufactured by combining an organic EL element and an organic photodiode, the number of film-forming steps can be suppressed by forming layers having the same configuration as that of the organic EL element in the same step.

[0168] For example, one of a pair of electrodes (common electrode) can be a common layer for the light-emitting / receiving element and the light-emitting element. Also, for example, it is preferable that at least one of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer be a common layer for the light-emitting / receiving element and the light-emitting element. Also, for example, except for the presence or absence of the active layer of the light-receiving element, the light-emitting / receiving element and the light-emitting element can have the same configuration. That is, a light-emitting / receiving element can also be manufactured by simply adding the active layer of the light-receiving element to the light-emitting element. Thus, since the light-emitting / receiving element and the light-emitting element have a common layer, the number of film-forming times and the number of masks can be reduced, and the manufacturing process and manufacturing cost of the display device can be reduced. Also, a display device having a light-emitting / receiving element can be manufactured using the existing manufacturing equipment and manufacturing method of the display device.

[0169] Note that the layers of the light-emitting and light-receiving element may have different functions when the light-emitting and light-receiving element functions as a light-receiving element and when it functions as a light-emitting element. In this specification, components are named based on the functions when the light-emitting and light-receiving element functions as a light-emitting element. For example, the hole injection layer functions as a hole injection layer when the light-emitting and light-receiving element functions as a light-emitting element, and functions as a hole transport layer when the light-emitting and light-receiving element functions as a light-receiving element. Similarly, the electron injection layer functions as an electron injection layer when the light-emitting and light-receiving element functions as a light-emitting element, and functions as an electron transport layer when the light-emitting and light-receiving element functions as a light-receiving element.

[0170] As described above, the display device of the present embodiment has a light-emitting and light-receiving element and a light-emitting element in the display unit. Specifically, in the display unit, the light-emitting and light-receiving elements and the light-emitting elements are each arranged in a matrix. Therefore, in addition to the function of displaying an image, the display unit also has one or both of an imaging function and a sensing function.

[0171] The display unit can be used for an image sensor or a touch sensor, etc. That is, by detecting light in the display unit, an image can be captured, or the approach or contact of an object (such as a finger or a pen) can be detected. Furthermore, the display device of the present embodiment can use the light-emitting element as a light source of the sensor. Therefore, it is not necessary to provide a light-receiving unit and a light source separately from the display device, and the number of components of the electronic device can be reduced.

[0172] In the display device of the present embodiment, when the light emitted from the light-emitting element of the display unit is reflected by an object, the light-emitting and light-receiving element can detect the reflected light. Therefore, imaging or touch (contact or approach) detection is possible even in a dark place.

[0173] The display device of the present embodiment has a function of displaying an image using the light-emitting element and the light-emitting and light-receiving element. That is, the light-emitting element and the light-emitting and light-receiving element function as display elements.

[0174] As the light-emitting element, it is preferable to use an EL element such as an OLED (Organic Light Emitting Diode) or a QLED (Quantum-dot Light Emitting Diode). Examples of the light-emitting substance included in the EL element include a substance that emits fluorescence (fluorescent material), a substance that emits phosphorescence (phosphorescent material), an inorganic compound (such as a quantum dot material), and a substance that exhibits thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) material). Further, an LED such as a micro LED (Light Emitting Diode) can also be used as the light-emitting element.

[0175] The display device of the present embodiment has a function of detecting light by using a light-receiving and emitting element. The light-receiving and emitting element can detect light having a shorter wavelength than the light emitted by the light-receiving and emitting element itself.

[0176] When the light-receiving and emitting element is used as an image sensor, the display device of the present embodiment can capture an image by using the light-receiving and emitting element. For example, the display device of the present embodiment can be used as a scanner.

[0177] For example, data such as fingerprints or palm prints can be acquired by using an image sensor. That is, a biometric authentication sensor can be incorporated into the display device of the present embodiment. By incorporating the biometric authentication sensor into the display device, the number of components of the electronic device can be reduced compared to the case where a biometric authentication sensor is provided separately from the display device, and the electronic device can be miniaturized and lightened.

[0178] In addition, by using an image sensor, it is possible to acquire data such as the user's facial expression, eye movement, or change in pupil diameter. By analyzing the data, it is possible to obtain information about the user's physical and mental state. Based on this information, by changing the output content of one or both of the display and audio, for example, in a device for VR (Virtual Reality), AR (Augmented Reality), or MR (Mixed Reality), it is possible to ensure that the user can safely use the device.

[0179] Also, when using a light-emitting and light-receiving element as a touch sensor, the display device of the present embodiment can detect the approach or contact of an object by using the light-emitting and light-receiving element.

[0180] The light-emitting and light-receiving element functions as a photoelectric conversion element that detects light incident on the light-emitting and light-receiving element and generates electric charges. The amount of generated electric charges is determined based on the amount of incident light.

[0181] The light-emitting and light-receiving element can be manufactured by adding an active layer of a light-receiving element to the configuration of the above-described light-emitting element.

[0182] For the light-emitting and light-receiving element, for example, an active layer of a pn-type or pin-type photodiode can be used.

[0183] In particular, it is preferable to use an active layer of an organic photodiode having a layer containing an organic compound for the light-emitting and light-receiving element. Since the organic photodiode is easy to thin, lightweight, and large-area, and also has a high degree of freedom in shape and design, it can be applied to various display devices.

[0184] Cross-sectional views of a display device according to an aspect of the present invention are shown in FIGS. 14A to 14D.

[0185] The display device 350A shown in FIG. 14A has a layer 353 having a light-emitting and light-receiving element and a layer 357 having a light-emitting element between a substrate 351 and a substrate 359.

[0186] The display device 350B shown in FIG. 14B has a layer 353 having light-emitting and light-receiving elements, a layer 355 having transistors, and a layer 357 having light-emitting elements between a substrate 351 and a substrate 359.

[0187] The display devices 350A and 350B are configured such that green (G) light and blue (B) light are emitted from the layer 357 having light-emitting elements, and red (R) light is emitted from the layer 353 having light-emitting and light-receiving elements. Note that in the display device according to one aspect of the present invention, the color of the light emitted from the layer 353 having light-emitting and light-receiving elements is not limited to red.

[0188] The light-emitting and light-receiving elements included in the layer 353 having light-emitting and light-receiving elements can detect light incident from outside the display device 350A or the display device 350B. The light-emitting and light-receiving elements can detect, for example, one or both of green (G) light and blue (B) light.

[0189] The display device according to one aspect of the present invention has a plurality of pixels arranged in a matrix. One pixel has one or more sub-pixels. One sub-pixel has one light-emitting and light-receiving element or one light-emitting element. For example, a configuration in which a pixel has three sub-pixels (three colors of R, G, and B, or three colors of yellow (Y), cyan (C), and magenta (M), etc.) or a configuration in which a pixel has four sub-pixels (four colors of R, G, B, and white (W), or four colors of R, G, B, and Y, etc.) can be applied. At least one color of sub-pixel has a light-emitting and light-receiving element. The light-emitting and light-receiving elements may be provided in all pixels or may be provided in some pixels. Also, one pixel may have a plurality of light-emitting and light-receiving elements.

[0190] The layer 355 having transistors has, for example, transistors electrically connected to the light-emitting and light-receiving elements and transistors electrically connected to the light-emitting elements. The layer 355 having transistors may further have wirings, electrodes, terminals, capacitors, resistors, and the like.

[0191] A display device according to an aspect of the present invention may have a function of detecting an object such as a finger in contact with the display device (FIG. 14C). Alternatively, it may have a function of detecting an object approaching (not in contact with) the display device (FIG. 14D). For example, as shown in FIGS. 14C and 14D, light emitted by a light-emitting element in a layer 357 having a light-emitting element is reflected by a finger 352 in contact with or approaching the display device 350B, and a light-receiving and emitting element in a layer 353 having a light-receiving and emitting element detects the reflected light. Thereby, it can be detected that the finger 352 has come into contact with or approached the display device 350B.

[0192] [Pixel] Examples of pixels are shown in FIGS. 14E to 14G and FIGS. 15A to 15D. Note that the arrangement order of the sub-pixels is not limited to the illustrated order. For example, the positions of the sub-pixel (B) and the sub-pixel (G) may be reversed.

[0193] The pixel shown in FIG. 14E has a stripe arrangement, exhibits red light, and has a sub-pixel (MER) having a light-receiving function, a sub-pixel (G) exhibiting green light, and a sub-pixel (B) exhibiting blue light. In a display device in which a pixel is composed of three sub-pixels of R, G, and B, a display device having a light-receiving function can be manufactured by replacing the light-emitting element used for the R sub-pixel with a light-receiving and emitting element.

[0194] The pixel shown in FIG. 14F has a matrix arrangement, exhibits red light, and has a sub-pixel (MER) having a light-receiving function, a sub-pixel (G) exhibiting green light, a sub-pixel (B) exhibiting blue light, and a sub-pixel (W) exhibiting white light. Also in a display device in which a pixel is composed of four sub-pixels of R, G, B, and W, a display device having a light-receiving function can be manufactured by replacing the light-emitting element used for the R sub-pixel with a light-receiving and emitting element.

[0195] The pixels shown in Fig. 14G have sub-pixels to which a pentile array is applied and which exhibit two different colors of light combined by the pixels. The upper-left pixel and the lower-right pixel shown in Fig. 14G exhibit red light and have a sub-pixel (MER) having a light-receiving function and a sub-pixel (G) exhibiting green light. The lower-left pixel and the upper-right pixel shown in Fig. 14G have a sub-pixel (G) exhibiting green light and a sub-pixel (B) exhibiting blue light. Note that the shape of the sub-pixels shown in Fig. 14G indicates the upper surface shape of the light-emitting element or the light-emitting and light-receiving element included in the sub-pixel.

[0196] The pixels shown in Fig. 15A have a sub-pixel (MER) having a light-receiving function and exhibiting red light, a sub-pixel (G) exhibiting green light, and a sub-pixel (B) exhibiting blue light. The sub-pixel (MER) is arranged in a column different from the sub-pixels (G) and (B). The sub-pixels (G) and (B) are alternately arranged in the same column, with one provided in odd rows and the other provided in even rows. Note that the sub-pixel arranged in a column different from the sub-pixels of other colors is not limited to red (R), and may be green (G) or blue (B).

[0197] Fig. 15B shows two pixels, and one pixel is constituted by three sub-pixels surrounded by a dotted line. The pixels shown in Fig. 15B have a sub-pixel (MER) having a light-receiving function and exhibiting red light, a sub-pixel (G) exhibiting green light, and a sub-pixel (B) exhibiting blue light. In the left pixel shown in Fig. 15B, the sub-pixel (G) is arranged in the same row as the sub-pixel (MER), and the sub-pixel (B) is arranged in the same column as the sub-pixel (MER). In the right pixel shown in Fig. 15B, the sub-pixel (G) is arranged in the same row as the sub-pixel (MER), and the sub-pixel (B) is arranged in the same column as the sub-pixel (G). In the pixel layout shown in Fig. 15B, the sub-pixels (MER), (G), and (B) are repeatedly arranged in both odd rows and even rows, and in each column, sub-pixels of different colors are arranged in odd rows and even rows.

[0198] FIG. 15C is a modified example of the pixel array shown in FIG. 14G. The upper left pixel and the lower right pixel shown in FIG. 15C exhibit red light and have a sub-pixel (MER) having a light receiving function and a sub-pixel (G) exhibiting green light. The lower left pixel and the upper right pixel shown in FIG. 15C exhibit red light and have a sub-pixel (MER) having a light receiving function and a sub-pixel (B) exhibiting blue light.

[0199] In FIG. 14G, a sub-pixel (G) that exhibits green light is provided for each pixel. On the other hand, in FIG. 15C, a sub-pixel (MER) that exhibits red light and has a light receiving function is provided for each pixel. Since a sub-pixel having a light receiving function is provided for each pixel, in the configuration shown in FIG. 15C, imaging can be performed with higher resolution than the configuration shown in FIG. 14G. Thereby, for example, the accuracy of biometric authentication can be improved.

[0200] Also, the upper surface shape of the light emitting element and the light emitting and receiving element is not particularly limited, and can be a circle, an ellipse, a polygon, a rounded polygon, or the like. Regarding the upper surface shape of the light emitting element included in the sub-pixel (G), an example of a circular shape is shown in FIG. 14G, and an example of a square shape is shown in FIG. 15C. The upper surface shapes of the light emitting elements and the light emitting and receiving elements of each color may be different from each other, or may be the same for some or all of the colors.

[0201] Also, the aperture ratios of the sub-pixels of each color may be different from each other, or may be the same for some or all of the colors. For example, the aperture ratio of the sub-pixel provided for each pixel (sub-pixel (G) in FIG. 14G, sub-pixel (MER) in FIG. 15C) may be made smaller than the aperture ratios of the sub-pixels of other colors.

[0202] FIG. 15D is a modified example of the pixel array shown in FIG. 15C. Specifically, the configuration of FIG. 15D is obtained by rotating the configuration of FIG. 15C by 45°. Although it has been described that one pixel is composed of two sub-pixels in FIG. 15C, as shown in FIG. 15D, it can also be considered that one pixel is composed of four sub-pixels.

[0203] In FIG. 15D, an explanation will be given on the assumption that one pixel is composed of four sub-pixels surrounded by dotted lines. One pixel has two sub-pixels (MER), one sub-pixel (G), and one sub-pixel (B). In this way, by having a plurality of sub-pixels with a light receiving function in one pixel, imaging can be performed with high definition. Therefore, the accuracy of biometric authentication can be improved. For example, the imaging definition can be set to √2 times the display definition.

[0204] The display device to which the configuration shown in FIG. 15C or FIG. 15D is applied includes p first light emitting elements (where p is an integer of 2 or more), q second light emitting elements (where q is an integer of 2 or more), and r light emitting and receiving elements (where r is an integer greater than p and greater than q). p and r satisfy r = 2p. Also, p, q, and r satisfy r = p + q. One of the first light emitting element and the second light emitting element emits green light, and the other emits blue light. The light emitting and receiving element emits red light and has a light receiving function.

[0205] For example, when performing touch detection using the light emitting and receiving element, it is preferable that the light emission from the light source is difficult for the user to visually recognize. Since blue light has lower visibility than green light, it is preferable to use a light emitting element that emits blue light as the light source. Therefore, the light emitting and receiving element preferably has a function of receiving blue light. Alternatively, infrared light that is not visually recognized by the user may be used as the light source.

[0206] As described above, pixels with various arrays can be applied to the display device according to one aspect of the present invention.

[0207] Since the display device according to the present embodiment does not require changing the pixel array to incorporate the light receiving function into the pixel, one or both of the imaging function and the sensing function can be added to the display unit without reducing the aperture ratio and the definition.

[0208] [Light emitting and receiving element] Examples of the stacked structure of the light emitting and receiving element are shown in FIGS. 16A to 16E.

[0209] The light-emitting and light-receiving element has at least an active layer and a light-emitting layer between a pair of electrodes.

[0210] As layers other than the active layer and the light-emitting layer, the light-emitting and light-receiving element may further have a layer containing a substance with high hole injection property, a substance with high hole transport property, a substance with high hole blocking property, a substance with high electron transport property, a substance with high electron injection property, a substance with high electron blocking property, or a bipolar substance (a substance with high electron transport property and high hole transport property), etc.

[0211] The light-emitting and light-receiving elements shown in FIGS. 16A to 16C each have a first electrode 180, a hole injection layer 181, a hole transport layer 182, an active layer 183, a light-emitting layer 193, an electron transport layer 184, an electron injection layer 185, and a second electrode 189.

[0212] Note that the light-emitting and light-receiving elements shown in FIGS. 16A to 16C can each be said to have a configuration in which an active layer 183 is added to the light-emitting element. Therefore, in the manufacturing process of the light-emitting element, by simply adding a step of forming the active layer 183, the light-emitting and light-receiving element can be formed in parallel with the formation of the light-emitting element. Also, the light-emitting element and the light-emitting and light-receiving element can be formed on the same substrate. Therefore, one or both of the imaging function and the sensing function can be imparted to the display unit without significantly increasing the manufacturing process.

[0213] The stacking order of the light-emitting layer 193 and the active layer 183 is not limited. FIG. 16A shows an example in which the active layer 183 is provided on the hole transport layer 182 and the light-emitting layer 193 is provided on the active layer 183. Also, FIG. 16B shows an example in which the light-emitting layer 193 is provided on the hole transport layer 182 and the active layer 183 is provided on the light-emitting layer 193. Also, as shown in FIGS. 16A and 16B, the active layer 183 and the light-emitting layer 193 may be in contact with each other.

[0214] As shown in Fig. 16C, it is preferable that a buffer layer is sandwiched between the active layer 183 and the light-emitting layer 193. As the buffer layer, at least one layer among a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole blocking layer, an electron blocking layer, etc. can be used. Fig. 16C shows an example in which a hole transport layer 182 is used as the buffer layer.

[0215] By providing a buffer layer between the active layer 183 and the light-emitting layer 193, the transfer of excitation energy from the light-emitting layer 193 to the active layer 183 can be suppressed. Also, the optical path length (cavity length) of the microcavity structure can be adjusted using the buffer layer. Therefore, a high luminous efficiency can be obtained from the light-emitting and receiving element having a buffer layer between the active layer 183 and the light-emitting layer 193.

[0216] The light-emitting and receiving element shown in Fig. 16D is different from the light-emitting and receiving elements shown in Figs. 16A and 16C in that it does not have a hole transport layer 182. The light-emitting and receiving element may not have at least one layer among a hole injection layer 181, a hole transport layer 182, an electron transport layer 184, and an electron injection layer 185. Also, the light-emitting and receiving element may have other functional layers such as a hole blocking layer and an electron blocking layer.

[0217] The light-emitting and receiving element shown in Fig. 16E is different from the light-emitting and receiving elements shown in Figs. 16A to 16C in that it does not have an active layer 183 and a light-emitting layer 193, but has a layer 186 that serves as both a light-emitting layer and an active layer.

[0218] As the layer 186 that serves as both a light-emitting layer and an active layer, for example, a layer containing three materials, namely an n-type semiconductor that can be used for the active layer 183, a p-type semiconductor that can be used for the active layer 183, and a light-emitting substance that can be used for the light-emitting layer 193, can be used.

[0219] Note that it is preferable that the absorption band on the lowest energy side of the absorption spectrum of the mixed material of the n-type semiconductor and the p-type semiconductor does not overlap with the maximum peak of the emission spectrum (PL spectrum) of the light-emitting substance, and it is more preferable that they are sufficiently separated.

[0220] In a light-emitting and light-receiving element, a conductive film that transmits visible light is used for the electrode on the light-extracting side. Further, it is preferable to use a conductive film that reflects visible light for the electrode on the side where light is not extracted.

[0221] When driving the light-emitting and light-receiving element as a light-emitting element, the hole injection layer is a layer that injects holes from the anode into the light-emitting and light-receiving element. The hole injection layer is a layer containing a material with high hole injection properties. As a material with high hole injection properties, an aromatic amine compound, or a composite material containing a hole-transporting material and an acceptor material (electron-accepting material) can be used.

[0222] When driving the light-emitting and light-receiving element as 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. When driving the light-emitting and light-receiving element as a light-receiving element, the hole transport layer is a layer that transports holes generated based on light incident on the active layer to the anode. The hole transport layer is a layer containing a hole-transporting material. As the hole-transporting material, a substance having a hole mobility of 1×10 -6 cm 2 / Vs or more is preferable. In addition, as long as the substance has higher hole transportability than electrons, other substances can also be used. As the hole-transporting material, a hole-transporting material with high hole transportability such as a π-electron-excessive heteroaromatic compound (for example, a carbazole derivative, a thiophene derivative, a furan derivative, etc.) or an aromatic amine (a compound having an aromatic amine skeleton) is preferable.

[0223] When driving the light-emitting and light-receiving element as 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. When driving the light-emitting and light-receiving element as a light-receiving element, the electron transport layer is a layer that transports electrons generated based on light incident on the active layer to the cathode. The electron transport layer is a layer containing an electron-transporting material. As the electron-transporting material, a substance having a hole mobility of 1×10 -6 cm 2A substance having an electron mobility of 1 / Vs or more is preferred. In addition, as long as the substance has higher electron transportability than holes, other substances can also be used. As the electron transport material, in addition to metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, etc., oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other electron transport materials such as π-electron-deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds can be used.

[0224] When driving the light-emitting element using the light-emitting element as a light-emitting element, the electron injection layer is a layer that injects electrons from the cathode into the light-emitting element. The electron injection layer is a layer containing a material with high electron injection properties. As the material with high electron injection properties, an alkali metal, an alkaline earth metal, or a compound thereof can be used. As the material with high electron injection properties, a composite material containing an electron transport material and a donor material (electron-donating material) can also be used.

[0225] The light-emitting layer 193 is a layer containing a light-emitting substance. The light-emitting layer 193 can have one or more kinds of light-emitting substances. As the light-emitting substance, substances exhibiting light-emitting colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red are appropriately used. In addition, as the light-emitting substance, a substance that emits near-infrared light can also be used.

[0226] Examples of the light-emitting substance include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0227] Examples of the fluorescent material 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, naphthalene derivatives, and the like.

[0228] Examples of the phosphorescent material include organometallic complexes (especially iridium complexes) having a 4H-triazole skeleton, 1H-triazole skeleton, imidazole skeleton, pyrimidine skeleton, pyrazine skeleton, or pyridine skeleton, organometallic complexes (especially iridium complexes) having a phenylpyridine derivative having an electron-withdrawing group as a ligand, platinum complexes, rare earth metal complexes, and the like.

[0229] In addition to the light-emitting substance (guest material), the light-emitting layer 193 may contain one or more organic compounds (host materials, assist materials, etc.). As the one or more organic compounds, one or both of a hole-transporting material and an electron-transporting material can be used. Further, a bipolar material or a TADF material may be used as the one or more organic compounds.

[0230] The light-emitting layer 193 preferably has, for example, a phosphorescent material, a hole-transporting material, and an electron-transporting material that are a combination likely to form an exciplex. By adopting such a configuration, light emission using ExTET (Exciplex-Triplet Energy Transfer), which is energy transfer from the exciplex to the light-emitting substance (phosphorescent material), can be efficiently obtained. By selecting a combination that forms an exciplex that exhibits light emission overlapping with the wavelength of the absorption band on the lowest energy side of the light-emitting substance, energy transfer becomes smooth and light emission can be efficiently obtained. With this configuration, high efficiency, low-voltage driving, and long life of the light-emitting element can be realized simultaneously.

[0231] As a combination of materials forming an exciplex, it is preferable that the HOMO level (highest occupied orbital level) of the hole transporting material is higher than the HOMO level of the electron transporting material. It is also preferable that the LUMO level (lowest unoccupied orbital level) of the hole transporting material is higher than the LUMO level of the electron transporting material. The LUMO level and HOMO level of the material can be derived from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV) measurement.

[0232] The formation of the exciplex can be confirmed, for example, by comparing the emission spectrum of the hole transporting material, the emission spectrum of the electron transporting material, and the emission spectrum of a mixed film in which these materials are mixed, and observing the phenomenon that the emission spectrum of the mixed film is shifted to a longer wavelength (or has a new peak on the longer wavelength side) than the emission spectra of the respective materials. Alternatively, by comparing the transient photoluminescence (PL) of the hole transporting material, the transient PL of the electron transporting material, and the transient PL of a mixed film in which these materials are mixed, and observing differences in transient responses such as the transient PL lifetime of the mixed film having a longer lifetime component or a larger ratio of the delayed component than the transient PL lifetimes of the respective materials, it can be confirmed. Also, the above-mentioned transient PL may be read as transient electroluminescence (EL). That is, by comparing the transient EL of the hole transporting material, the transient EL of the material having electron transporting properties, and the transient EL of a mixed film thereof, and observing differences in transient responses, the formation of the exciplex can also be confirmed.

[0233] The active layer 183 contains a semiconductor. Examples of such a semiconductor include inorganic semiconductors such as silicon and organic semiconductors containing organic compounds. In the present embodiment, an example in which an organic semiconductor is used as the semiconductor included in the active layer is shown. Using an organic semiconductor is preferable because the light emitting layer 193 and the active layer 183 can be formed by the same method (for example, vacuum evaporation method), and the manufacturing equipment can be shared.

[0234] Examples of the material of the n-type semiconductor included in the active layer 183 include fullerenes (for example, C 60 , C 70Examples of the electron-accepting organic semiconductor materials include fullerenes, fullerene derivatives, etc. Fullerene has a soccer ball-like shape, and this shape is energetically stable. For fullerene, both the HOMO level and the LUMO level are deep (low). Since the LUMO level of fullerene is deep, its electron-accepting (acceptor) property is extremely high. Usually, like benzene, when the π-electron conjugation (resonance) spreads in a plane, the electron-donating (donor) property increases. However, since fullerene has a spherical shape, despite the large spread of π-electrons, its electron-accepting property is high. A high electron-accepting property is beneficial for a light-receiving element because it causes charge separation to occur efficiently at high speed. C 60 , C 70 Both have broad absorption bands in the visible light region. In particular, C 70 is preferable because it has a larger π-electron conjugation system than C 60 and also has a broad absorption band in the long-wavelength region.

[0235] In addition, examples of the 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, quinone derivatives, etc.

[0236] Examples of the p-type semiconductor materials included in the active layer 183 include electron-donating organic semiconductor materials such as copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), quinacridone, etc.

[0237] In addition, examples of the p-type semiconductor material include carbazole derivatives, thiophene derivatives, furan derivatives, compounds having an aromatic amine skeleton, and the like. Further, examples of the p-type semiconductor material 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, polyphenylene vinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, polythiophene derivatives, and the like.

[0238] 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. 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.

[0239] As the electron-accepting organic semiconductor material, it is preferable to use spherical fullerene, and as the electron-donating organic semiconductor material, it is preferable to use an organic semiconductor material having a shape close to a plane. Molecules with similar shapes tend to aggregate easily. When the same type of molecules aggregate, since the energy levels of the molecular orbitals are close, the carrier transport property can be enhanced.

[0240] For example, the active layer 183 is preferably formed by co-evaporating an n-type semiconductor and a p-type semiconductor.

[0241] The layer 186 that also serves as the light-emitting layer and the active layer is preferably formed using the above-described light-emitting substance, n-type semiconductor, and p-type semiconductor.

[0242] For the hole injection layer 181, hole transport layer 182, active layer 183, light-emitting layer 193, electron transport layer 184, electron injection layer 185, and layer 186 that also serves as both a light-emitting layer and an active layer, either a low molecular weight compound or a high molecular weight compound can be used, and an inorganic compound may also be included. Each layer can be formed by methods such as vapor deposition (including vacuum vapor deposition), transfer method, printing method, inkjet method, coating method, etc.

[0243] Hereinafter, with reference to FIGS. 17 to 19, the detailed configurations of the light-emitting and light-receiving elements included in the display device according to one embodiment of the present invention will be described.

[0244] The display device according to one embodiment of the present invention may be any of a top emission type that emits light in a direction opposite to the substrate on which the light-emitting element is formed, a bottom emission type that emits light on the substrate side where the light-emitting element is formed, and a dual emission type that emits light on both sides.

[0245] In FIGS. 17 to 19, a top emission type display device will be described as an example.

[0246] [Configuration Example 1] The display devices shown in FIGS. 17A and 17B include a light-emitting element 347B that emits blue (B) light, a light-emitting element 347G that emits green (G) light, and a light-emitting and light-receiving element 347MER that emits red (R) light and has a light-receiving function, via a layer 355 having transistors on a substrate 151.

[0247] FIG. 17A shows a case where the light-emitting and light-receiving element 347MER functions as a light-emitting element. FIG. 17A shows an example in which the light-emitting element 347B emits blue light, the light-emitting element 347G emits green light, and the light-emitting and light-receiving element 347MER emits red light.

[0248] FIG. 17B shows a case where the light-emitting and light-receiving element 347MER functions as a light-receiving element. FIG. 17B shows an example in which the light-emitting and light-receiving element 347MER detects the blue light emitted by the light-emitting element 347B and the green light emitted by the light-emitting element 347G.

[0249] The light-emitting element 347B, the light-emitting element 347G, and the light-receiving and light-emitting element 347MER each have a pixel electrode 191 and a common electrode 115. In the present embodiment, a case where the pixel electrode 191 functions as an anode and the common electrode 115 functions as a cathode will be described as an example.

[0250] In the present embodiment, similar to the light-emitting element, in the light-receiving and light-emitting element 347MER as well, it will be described that the pixel electrode 191 functions as an anode and the common electrode 115 functions as a cathode. That is, the light-receiving and light-emitting element 347MER can detect the light incident on the light-receiving and light-emitting element 347MER, generate charges, and extract them as a current by applying a reverse bias between the pixel electrode 191 and the common electrode 115 and driving it.

[0251] The common electrode 115 is commonly used for the light-emitting element 347B, the light-emitting element 347G, and the light-receiving and light-emitting element 347MER.

[0252] The materials, film thicknesses, etc. of the pair of electrodes of the light-emitting element 347B, the light-emitting element 347G, and the light-receiving and light-emitting element 347MER can be made equal. Thereby, the manufacturing cost of the display device can be reduced and the manufacturing process can be simplified.

[0253] The configuration of the display device shown in FIGS. 17A and 17B will be specifically described.

[0254] The light-emitting element 347B has a buffer layer 192B, a light-emitting layer 193B, and a buffer layer 194B in this order on the pixel electrode 191. The light-emitting layer 193B has a light-emitting substance that emits blue light. The light-emitting element 347B has a function of emitting blue light.

[0255] The light-emitting element 347G has a buffer layer 192G, a light-emitting layer 193G, and a buffer layer 194G in this order on the pixel electrode 191. The light-emitting layer 193G has a light-emitting substance that emits green light. The light-emitting element 347G has a function of emitting green light.

[0256] The light-emitting and light-receiving element 347MER has a buffer layer 192R, an active layer 183, a light-emitting layer 193R, and a buffer layer 194R in this order on the pixel electrode 191. The light-emitting layer 193R has a light-emitting substance that emits red light. The active layer 183 has an organic compound that absorbs light with a shorter wavelength than red light (for example, one or both of green light and blue light). Note that an organic compound that absorbs not only visible light but also ultraviolet light may be used for the active layer 183. The light-emitting and light-receiving element 347MER has a function of emitting red light. The light-emitting and light-receiving element 347MER preferably has a function of detecting the light emission of at least one of the light-emitting elements 347G and 347B, and more preferably has a function of detecting the light emission of both of them.

[0257] The active layer 183 preferably has an organic compound that hardly absorbs red light and absorbs light with a shorter wavelength than red light. Thereby, the light-emitting and light-receiving element 347MER can have a function of efficiently emitting red light and a function of accurately detecting light with a shorter wavelength than red light.

[0258] The pixel electrode 191, the buffer layer 192R, the buffer layer 192G, the buffer layer 192B, the active layer 183, the light-emitting layer 193R, the light-emitting layer 193G, the light-emitting layer 193B, the buffer layer 194R, the buffer layer 194G, the buffer layer 194B, and the common electrode 115 may each have a single-layer structure or a stacked structure.

[0259] In the display device shown in FIGS. 17A and 17B, the buffer layer, the active layer, and the light-emitting layer are layers that are separately formed for each element.

[0260] The buffer layers 192R, 192G, and 192B can each have one or both of a hole injection layer and a hole transport layer. Further, the buffer layers 192R, 192G, and 192B may have an electron blocking layer. The buffer layers 194B, 194G, and 194R can each have one or both of an electron injection layer and an electron transport layer. Further, the buffer layers 194R, 194G, and 194B may have a hole blocking layer. Note that for the materials and the like of each layer constituting the light-emitting element, reference can be made to the description of each layer constituting the above-described light-emitting and light-receiving element.

[0261] [Configuration Example 2] As shown in FIGS. 18A and 18B, the light-emitting elements 347B, 347G, and the light-emitting and light-receiving element 347MER may have a common layer between a pair of electrodes. Thereby, the light-emitting and light-receiving element can be incorporated into the display device without significantly increasing the manufacturing process.

[0262] The light-emitting elements 347B, 347G, and the light-emitting and light-receiving element 347MER shown in FIG. 18A have a common layer 112 and a common layer 114 in addition to the configuration shown in FIGS. 17A and 17B.

[0263] The light-emitting elements 347B, 347G, and the light-emitting and light-receiving element 347MER shown in FIG. 18B are different from the configuration shown in FIGS. 17A and 17B in that they do not have the buffer layers 192R, 192G, 192B and the buffer layers 194R, 194G, 194B, but have the common layer 112 and the common layer 114.

[0264] The common layer 112 can have one or both of a hole injection layer and a hole transport layer. The common layer 114 can have one or both of an electron injection layer and an electron transport layer.

[0265] The common layer 112 and the common layer 114 may each have a single-layer structure or a stacked structure.

[0266] [Configuration Example 3] The display device shown in Fig. 19A is an example in which the laminated structure shown in Fig. 16C is applied to the light-emitting and light-receiving element 347MER.

[0267] The light-emitting and light-receiving element 347MER has, on the pixel electrode 191, a hole injection layer 181, an active layer 183, a hole transport layer 182R, a light-emitting layer 193R, an electron transport layer 184, an electron injection layer 185, and a common electrode 115 in this order.

[0268] The hole injection layer 181, the electron transport layer 184, the electron injection layer 185, and the common electrode 115 are layers common to the light-emitting element 347G and the light-emitting element 347B.

[0269] The light-emitting element 347G has, on the pixel electrode 191, a hole injection layer 181, a hole transport layer 182G, a light-emitting layer 193G, an electron transport layer 184, an electron injection layer 185, and a common electrode 115 in this order.

[0270] The light-emitting element 347B has, on the pixel electrode 191, a hole injection layer 181, a hole transport layer 182B, a light-emitting layer 193B, an electron transport layer 184, an electron injection layer 185, and a common electrode 115 in this order.

[0271] It is preferable that a microcavity structure is applied to the light-emitting element included in the display device of the present embodiment. Therefore, it is preferable that one of the pair of electrodes included in the light-emitting element has an electrode (semi-transmissive and semi-reflective electrode) having transmissivity and reflectivity with respect to visible light, and the other has an electrode (reflective electrode) having reflectivity with respect to visible light. By having a microcavity structure in the light-emitting element, the light emitted from the light-emitting layer can be resonated between both electrodes, and the light emitted from the light-emitting element can be enhanced.

[0272] Note that the semi-transmissive / semi-reflective electrode can have a laminated structure of a reflective electrode and an electrode having permeability to visible light (also referred to as a transparent electrode). In this specification and the like, the reflective electrode that functions as a part of the semi-transmissive / semi-reflective electrode may be described as a pixel electrode or a common electrode, and the transparent electrode may be described as an optical adjustment layer. However, it can sometimes be said that the transparent electrode (optical adjustment layer) also has the function of a pixel electrode or a common electrode.

[0273] The light transmittance of the transparent electrode shall be 40% or more. For example, for the light-emitting element, it is preferable to use an electrode having a transmittance of 40% or more for each of visible light (light with a wavelength of 400 nm or more and less than 750 nm) and near-infrared light (light with a wavelength of 750 nm or more and 1300 nm or less). Further, the reflectance of each of visible light and near-infrared light of the semi-transmissive / semi-reflective electrode shall be 10% or more and 95% or less, preferably 30% or more and 80% or less. The reflectance of visible light and near-infrared light of the reflective electrode shall be 40% or more and 100% or less, preferably 70% or more and 100% or less. Also, the resistivity of these electrodes is preferably -2 1×10 Ωcm or less.

[0274] The hole transport layers 182B, 182G, and 182R may each have the function as an optical adjustment layer. Specifically, for the light-emitting element 347B, it is preferable to adjust the film thickness of the hole transport layer 182B so that the optical distance between a pair of electrodes becomes an optical distance that enhances blue light. Similarly, for the light-emitting element 347G, it is preferable to adjust the film thickness of the hole transport layer 182G so that the optical distance between a pair of electrodes becomes an optical distance that enhances green light. And for the light-emitting and receiving element 347MER, it is preferable to adjust the film thickness of the hole transport layer 182R so that the optical distance between a pair of electrodes becomes an optical distance that enhances red light. The layer used as the optical adjustment layer is not limited to the hole transport layer. Note that in the case where the semi-transmissive / semi-reflective electrode has a laminated structure of a reflective electrode and a transparent electrode, the optical distance between a pair of electrodes indicates the optical distance between a pair of reflective electrodes.

[0275] [Configuration Example 4] The display device shown in FIG. 19B is an example in which the laminated structure shown in FIG. 16D is applied to the light-emitting and receiving element 347MER.

[0276] The light-emitting element 347MER has a hole injection layer 181, an active layer 183, a light-emitting layer 193R, an electron transport layer 184, an electron injection layer 185, and a common electrode 115 on the pixel electrode 191 in this order.

[0277] The hole injection layer 181, the electron transport layer 184, the electron injection layer 185, and the common electrode 115 are layers common to the light-emitting element 347G and the light-emitting element 347B.

[0278] The light-emitting element 347G has a hole injection layer 181, a hole transport layer 182G, a light-emitting layer 193G, an electron transport layer 184, an electron injection layer 185, and a common electrode 115 on the pixel electrode 191 in this order.

[0279] The light-emitting element 347B has a hole injection layer 181, a hole transport layer 182B, a light-emitting layer 193B, an electron transport layer 184, an electron injection layer 185, and a common electrode 115 on the pixel electrode 191 in this order.

[0280] The hole transport layer is provided in the light-emitting element 347G and the light-emitting element 347B, and is not provided in the light-emitting and receiving element 347MER. Thus, in addition to the active layer and the light-emitting layer, there may be a layer provided only in one of the light-emitting element and the light-emitting and receiving element.

[0281] Hereinafter, with reference to FIGS. 20 to 25, the detailed configuration of a display device according to an aspect of the present invention will be described.

[0282] [Display device 310A] Cross-sectional views of the display device 310A are shown in FIGS. 20A and 20B.

[0283] The display device 310A includes a light-emitting element 190B, a light-emitting element 190G, and a light-emitting and receiving element 190MER.

[0284] The light-emitting element 190B includes a pixel electrode 191, a buffer layer 192B, a light-emitting layer 193B, a buffer layer 194B, and a common electrode 115. The light-emitting element 190B has a function of emitting blue light 321B.

[0285] The light-emitting element 190G includes a pixel electrode 191, a buffer layer 192G, a light-emitting layer 193G, a buffer layer 194G, and a common electrode 115. The light-emitting element 190G has a function of emitting green light 321G.

[0286] The light-emitting and light-receiving element 190MER includes a pixel electrode 191, a buffer layer 192R, an active layer 183, a light-emitting layer 193R, a buffer layer 194R, and a common electrode 115. The light-emitting and light-receiving element 190MER has a function of emitting red light 321R and a function of detecting light 322.

[0287] FIG. 20A shows a case where the light-emitting and light-receiving element 190MER functions as a light-emitting element. FIG. 20A shows an example in which the light-emitting element 190B emits blue light, the light-emitting element 190G emits green light, and the light-emitting and light-receiving element 190MER emits red light.

[0288] FIG. 20B shows a case where the light-emitting and light-receiving element 190MER functions as a light-receiving element. FIG. 20B shows an example in which the light-emitting and light-receiving element 190MER detects blue light emitted by the light-emitting element 190B and green light emitted by the light-emitting element 190G.

[0289] The pixel electrode 191 is located on the insulating layer 214. The end portion of the pixel electrode 191 is covered by the partition wall 216. Two adjacent pixel electrodes 191 are electrically insulated from each other (also referred to as electrically separated) by the partition wall 216.

[0290] As the partition wall 216, an organic insulating film is suitable. Examples of materials that can be used for the organic insulating film include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimide amide resin, siloxane resin, benzocyclobutene-based resin, phenol resin, and precursors of these resins. The partition wall 216 is a layer that transmits visible light. Although details will be described later, a partition wall that blocks visible light may be provided instead of the partition wall 216.

[0291] The display device 310A has a light-emitting and receiving element 190MER, a light-emitting element 190G, a light-emitting element 190B, a transistor 342, etc. between a pair of substrates (substrate 151 and substrate 152).

[0292] The light-emitting and receiving element 190MER has a function of detecting light. Specifically, the light-emitting and receiving element 190MER is a photoelectric conversion element that receives the light 322 incident from outside the display device 310A and converts it into an electrical signal. The light 322 can also be the light reflected by the object from the light emission of one or both of the light-emitting element 190G and the light-emitting element 190B. Further, the light 322 may be incident on the light-emitting and receiving element 190MER through a lens.

[0293] The light-emitting element 190G and the light-emitting element 190B have a function of emitting visible light. Specifically, the light-emitting element 190G and the light-emitting element 190B are electroluminescent elements that emit light toward the substrate 152 side by applying a voltage between the pixel electrode 191 and the common electrode 115 (see the light 321G and the light 321B).

[0294] The buffer layer 192 (buffer layer 192R, buffer layer 192G, and buffer layer 192B), the light-emitting layer 193, and the buffer layer 194 (buffer layer 194R, buffer layer 194G, and buffer layer 194B) can also be referred to as an organic layer (a layer containing an organic compound) or an EL layer. The pixel electrode 191 preferably has a function of reflecting visible light. The common electrode 115 has a function of transmitting visible light.

[0295] The pixel electrode 191 is electrically connected to the source or drain of the transistor 342 through an opening provided in the insulating layer 214. The transistor 342 has a function of controlling the driving of the light-emitting element or the light-emitting and receiving element.

[0296] At least a part of the circuit electrically connected to the emitting and receiving element 190MER is preferably formed of the same material and in the same process as the circuit electrically connected to the light emitting elements 190G and 190B. Thereby, compared with the case where the two circuits are formed separately, the thickness of the display device can be reduced and the manufacturing process can be simplified.

[0297] The emitting and receiving element 190MER, the light emitting element 190G, and the light emitting element 190B are each preferably covered with a protective layer 195. In FIG. 20A and the like, the protective layer 195 is provided in contact with the common electrode 115. By providing the protective layer 195, it is possible to suppress the entry of impurities such as the emitting and receiving element 190MER and the light emitting elements of each color, and to enhance the emitting and receiving element 190MER and the light emitting devices of each color. Further, the protective layer 195 and the substrate 152 are bonded together by an adhesive layer 142.

[0298] A light shielding layer BM is provided on the surface of the substrate 152 on the side of the substrate 151. The light shielding layer BM has openings at positions overlapping the light emitting elements 190G and 190B, and at positions overlapping the emitting and receiving element 190MER. In this specification and the like, the position overlapping the light emitting element 190G or 190B specifically refers to the position overlapping the light emitting region of the light emitting element 190G or 190B. Similarly, the position overlapping the emitting and receiving element 190MER specifically refers to the position overlapping the light emitting region and the light receiving region of the emitting and receiving element 190MER.

[0299] As shown in FIG. 20B, the light-emitting element 190G or the light-emitting element 190B emits light, and the light-emitting and light-receiving element 190MER can detect the light reflected by the object. However, the light emitted from the light-emitting element 190G or the light-emitting element 190B may be reflected within the display device 310A and incident on the light-emitting and light-receiving element 190MER without passing through the object. The light-shielding layer BM can suppress the influence of such stray light. For example, when the light-shielding layer BM is not provided, the light 323 emitted from the light-emitting element 190G may be reflected by the substrate 152, and the reflected light 324 may be incident on the light-emitting and light-receiving element 190MER. By providing the light-shielding layer BM, it is possible to suppress the incident of the reflected light 324 on the light-emitting and light-receiving element 190MER. Thereby, noise can be reduced and the sensitivity of the sensor using the light-emitting and light-receiving element 190MER can be enhanced.

[0300] As the light-shielding layer BM, a material that blocks the light emitted from the light-emitting element can be used. The light-shielding layer BM preferably absorbs visible light. As the light-shielding layer BM, for example, a black matrix can be formed using a metal material, or a resin material containing a pigment (such as carbon black) or a dye. The light-shielding layer BM may have a laminated structure of a red color filter, a green color filter, and a blue color filter.

[0301] [Display device 310B] The display device 310B shown in FIG. 21A is different from the display device 310A in that the light-emitting element 190G, the light-emitting element 190B, and the light-emitting and light-receiving element 190MER do not have the buffer layer 192 and the buffer layer 194 respectively, but have the common layer 112 and the common layer 114. In the following description of the display device, the description of the same configuration as the previously described display device may be omitted.

[0302] Note that the laminated structures of the light-emitting element 190B, the light-emitting element 190G, and the light-emitting and light-receiving element 190MER are not limited to the configurations shown in the display devices 310A and 310B. For each element, for example, the laminated structures shown in FIGS. 16 to 19 can be appropriately applied.

[0303] [Display device 310C] The display device 310C shown in FIG. 21B is different from the display device 310B in that it does not have the substrates 151 and 152, but has the substrates 153, 154, the adhesive layer 155, and the insulating layer 212.

[0304] The substrate 153 and the insulating layer 212 are bonded together by the adhesive layer 155. The substrate 154 and the protective layer 195 are bonded together by the adhesive layer 142.

[0305] The display device 310C is configured by transferring the insulating layer 212, the transistor 342, the light-emitting and receiving element 190MER, the light-emitting element 190G, the light-emitting element 190B, etc. formed on the production substrate onto the substrate 153. The substrates 153 and 154 preferably each have flexibility. Thereby, the flexibility of the display device 310C can be enhanced. For example, it is preferable to use resin for each of the substrates 153 and 154.

[0306] As the substrates 153 and 154, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamideimide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. can be used. Glass having a thickness sufficient to have flexibility may be used for one or both of the substrates 153 and 154.

[0307] For the substrate included in the display device of the present embodiment, a film with high optical isotropy may be used. Examples of the film with high optical isotropy include a triacetyl cellulose (TAC, also referred to as cellulose triacetate) film, a cycloolefin polymer (COP) film, a cycloolefin copolymer (COC) film, and an acrylic film.

[0308] Hereinafter, with reference to FIGS. 22 to 25, a more detailed configuration of the display device according to one aspect of the present invention will be described.

[0309] [Display device 100A] FIG. 22 shows a perspective view of the display device 100A, and FIG. 23 shows a cross-sectional view of the display device 100A.

[0310] The display device 100A has a configuration in which a substrate 152 and a substrate 151 are bonded together. In FIG. 22, the substrate 152 is indicated by a broken line.

[0311] The display device 100A includes a display unit 162, a circuit 164, a wiring 165, etc. FIG. 22 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. 22 can also be referred to as a display module having the display device 100A, the IC, and the FPC.

[0312] As the circuit 164, for example, a scanning line driving circuit can be used.

[0313] The wiring 165 has a function of supplying signals and power to the display unit 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.

[0314] FIG. 22 shows an example in which an IC 173 is provided on a substrate 151 by a COG (Chip On Glass) method, a COF (Chip on Film) method, or the like. As the IC 173, for example, an IC having a scanning line driving circuit, a signal line driving circuit, or the like can be applied. Note that the display device 100A and the display module may be configured not to include an IC. Further, the IC may be mounted on an FPC by a COF method or the like.

[0315] FIG. 23 shows an example of a cross section when a part of the region including the FPC 172, a part of the region including the circuit 164, a part of the region including the display unit 162, and a part of the region including the end portion of the display device 100A shown in FIG. 22 are each cut.

[0316] The display device 100A shown in FIG. 23 includes 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 and receiving element 190MER, etc. between a substrate 151 and a substrate 152.

[0317] The substrate 152 and the insulating layer 214 are adhered via an adhesive layer 142. For sealing the light-emitting element 190B, the light-emitting element 190G, and the light-emitting and receiving element 190MER, a solid sealing structure, a hollow sealing structure, or the like can be applied. In FIG. 23, a space 143 surrounded by the substrate 152, the adhesive layer 142, and the insulating layer 214 is filled with an inert gas (such as nitrogen or argon), and a hollow sealing structure is applied. The adhesive layer 142 may be provided so as to overlap with the light-emitting element 190B, the light-emitting element 190G, and the light-emitting and receiving element 190MER. Further, 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.

[0318] The light-emitting element 190B has a stacked 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 stacked in this order from the insulating layer 214 side. The pixel electrode 191 is connected to a conductive layer 222b included in the transistor 207 through an opening provided in the insulating layer 214. The transistor 207 has a function of controlling the driving of the light-emitting element 190B. An end portion of the pixel electrode 191 is covered by a partition wall 216. The pixel electrode 191 includes a material that reflects visible light, and the common electrode 115 includes a material that transmits visible light.

[0319] The light-emitting element 190G has a stacked 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 included in the transistor 206 through an opening provided in the insulating layer 214. The transistor 206 has a function of controlling the driving of the light-emitting element 190G.

[0320] The light-emitting and receiving element 190MER has a stacked 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 stacked in this order from the insulating layer 214 side. The pixel electrode 191 is electrically connected to a conductive layer 222b included in 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 and receiving element 190MER.

[0321] The light emitted by the light-emitting element 190B, the light-emitting element 190G, and the light-emitting and receiving element 190MER is emitted toward the substrate 152 side. Further, light is incident on the light-emitting and receiving element 190MER through the substrate 152 and the space 143. It is preferable to use a material having high transmittance for visible light for the substrate 152.

[0322] The pixel electrodes 191 can be fabricated 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-emitting and receiving element 190MER. The light-emitting and receiving element 190MER has a configuration in which an active layer 183 is added to the configuration of a light-emitting element that exhibits red light. Further, the light-emitting element 190B, the light-emitting element 190G, and the light-emitting and receiving element 190MER can all have the same configuration except that the configurations of the active layer 183 and the light-emitting layers 193 of different colors are different. Thereby, a light-receiving function can be added to the display unit 162 of the display device 100A without significantly increasing the manufacturing process.

[0323] A light-shielding layer BM is provided on the surface of the substrate 152 on the side of the substrate 151. The light-shielding layer BM has openings at positions overlapping with each of the light-emitting element 190B, the light-emitting element 190G, and the light-emitting and receiving element 190MER. By providing the light-shielding layer BM, the range in which the light-emitting and receiving element 190MER detects light can be controlled. Further, by having the light-shielding layer BM, it is possible to suppress light from directly entering the light-emitting and receiving element 190MER from the light-emitting element 190G or the light-emitting element 190B without passing through an object. Therefore, a sensor with less noise and high sensitivity can be realized.

[0324] The transistors 201, 205, 206, and 207 are all formed on the substrate 151. These transistors can be fabricated using the same material and the same process.

[0325] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided on 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 transistors. The insulating layer 214 is provided to cover the transistors and has a function 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.

[0326] It is preferable to use a material in which impurities such as water or hydrogen hardly diffuse in at least one of the insulating layers covering the transistor. Thereby, the insulating layer can function as a barrier layer. With such a configuration, diffusion of impurities from the outside into the transistor can be effectively suppressed, and the reliability of the display device can be improved.

[0327] As the insulating layer 211, the insulating layer 213, and the insulating layer 215, it is preferable to use an inorganic insulating film respectively. As the inorganic insulating film, for example, an inorganic insulating film such as a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, or an aluminum nitride film can be used. Further, an hafnium oxide film, a hafnium oxynitride film, a hafnium nitride oxide film, a 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. Further, two or more of the above-described insulating films may be laminated and used. Note that an underlayer film may be provided between the substrate 151 and the transistor. The above-described inorganic insulating film can also be used for the underlayer film.

[0328] Here, the organic insulating film often has lower barrier properties than the inorganic insulating film. Therefore, the organic insulating film preferably has an opening near the end of the display device 100A. Thereby, entry of impurities through the organic insulating film from the end of the display device 100A can be suppressed. Alternatively, the organic insulating film may be formed such that the end of the organic insulating film is inside the end of the display device 100A so that the organic insulating film is not exposed at the end of the display device 100A.

[0329] An organic insulating film is suitable for the insulating layer 214 that functions as a planarization layer. Examples of materials that can be used for the organic insulating film include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimide amide resin, siloxane resin, benzocyclobutene-based resin, phenol resin, and precursors of these resins.

[0330] In the region 228 shown in FIG. 23, an opening is formed in the insulating layer 214. Thus, even when an organic insulating film is used for the insulating layer 214, it is possible to suppress impurities from entering the display unit 162 from the outside through the insulating layer 214. Therefore, the reliability of the display device 100A can be improved.

[0331] The transistors 201, 205, 206, and 207 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 given to a plurality of 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.

[0332] The structure of the transistor included in the display device of the present embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, an inverse staggered transistor, or the like can be used. Also, either a top gate type or a bottom gate type transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0333] In the transistors 201, 205, 206, and 207, a configuration is applied in which the semiconductor layer in which the channel is formed is sandwiched between two gates. The transistor may be driven by connecting the two gates and supplying the same signal thereto. 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.

[0334] The crystallinity of the semiconductor material used for the transistor is not particularly limited, and any of an amorphous semiconductor, a single crystal semiconductor, or a semiconductor having crystallinity (microcrystalline semiconductor, polycrystalline semiconductor, or semiconductor having a crystalline region in part) may be used. It is preferable to use a single crystal semiconductor or a semiconductor having crystallinity because deterioration of transistor characteristics can be suppressed.

[0335] The semiconductor layer of the transistor preferably has 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, crystalline silicon (such as low-temperature polysilicon, single crystal silicon, etc.).

[0336] The semiconductor layer preferably has, for example, indium, M (where M is one or more 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 selected from aluminum, gallium, yttrium, and tin.

[0337] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also denoted as IGZO) as 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 having indium and zinc.

[0338] 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 the atomic ratios of the metal elements in such an In-M-Zn oxide include a composition of In:M:Zn = 1:1:1 or in the vicinity thereof, a composition of In:M:Zn = 1:1:1.2 or in the vicinity thereof, a composition of In:M:Zn = 2:1:3 or in the vicinity thereof, a composition of In:M:Zn = 3:1:2 or in the vicinity thereof, a composition of In:M:Zn = 4:2:3 or in the vicinity thereof, a composition of In:M:Zn = 4:2:4.1 or in the vicinity thereof, a composition of In:M:Zn = 5:1:3 or in the vicinity thereof, a composition of In:M:Zn = 5:1:6 or in the vicinity thereof, a composition of In:M:Zn = 5:1:7 or in the vicinity thereof, a composition of In:M:Zn = 5:1:8 or in the vicinity thereof, a composition of In:M:Zn = 10:1:3 or in the vicinity thereof, a composition of In:M:Zn = 6:1:6 or in the vicinity thereof, a composition of In:M:Zn = 5:2:5 or in the vicinity thereof, and the like. The composition in the vicinity means a range including ±30% of the desired atomic ratio.

[0339] For example, when the atomic ratio is described as In:Ga:Zn = 4:2:3 or in the vicinity thereof, when the atomic ratio of In is 4, it includes cases where the atomic ratio of Ga is 1 or more and 3 or less, and the atomic ratio of Zn is 2 or more and 4 or less. Also, when the atomic ratio is described as In:Ga:Zn = 5:1:6 or in the vicinity thereof, when the atomic ratio of In is 5, it includes cases where the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is 5 or more and 7 or less. Also, when the atomic ratio is described as In:Ga:Zn = 1:1:1 or in the vicinity thereof, when the atomic ratio of In is 1, it includes cases where the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is greater than 0.1 and 2 or less.

[0340] The transistor included in circuit 164 and the transistor included in display unit 162 may have the same structure or different structures. The structures of the plurality of transistors included in circuit 164 may all be the same or there may be two or more types. Similarly, the structures of the plurality of transistors included in display unit 162 may all be the same or there may be two or more types.

[0341] In the area of the substrate 151 where the substrate 152 does not overlap, a connection portion 204 is provided. In the connection portion 204, the wiring 165 is electrically connected to the FPC 172 via the conductive layer 166 and the connection layer 242. On the upper surface of the connection portion 204, the conductive layer 166 obtained by processing the same conductive film as the pixel electrode 191 is exposed. Thereby, the connection portion 204 and the FPC 172 can be electrically connected via the connection layer 242.

[0342] Various optical members can be arranged outside the substrate 152. Examples of the optical members include a polarizing plate, a retardation plate, a light diffusion layer (such as a diffusion film), an antireflection layer, and a condensing film. Further, outside the substrate 152, an antistatic film for suppressing dust adhesion, a water-repellent film for making it difficult for dirt to adhere, a hard coat film for suppressing the occurrence of scratches during use, a shock absorption layer, etc. may be arranged.

[0343] For the substrate 151 and the substrate 152, glass, quartz, ceramic, sapphire, resin, etc. can be used respectively. When a flexible material is used for the substrate 151 and the substrate 152, the flexibility of the display device can be enhanced.

[0344] As the adhesive layer, various curable adhesives such as a photocurable adhesive such as an ultraviolet curable type, a reaction curable adhesive, a thermosetting adhesive, and an anaerobic adhesive can be used. Examples of these adhesives include epoxy resin, acrylic resin, silicone resin, phenolic resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin, EVA (ethylene vinyl acetate) resin, etc. In particular, a material with low moisture permeability such as epoxy resin is preferable. Also, a two-component mixed resin may be used. Also, an adhesive sheet or the like may be used.

[0345] As the connection layer, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), etc. can be used.

[0346] As materials that can be used for the gate, source, and drain of a transistor, as well as for conductive layers such as various wirings and electrodes constituting a display device, there are metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, and alloys mainly composed of such metals. Films containing these materials can be used as a single layer or in a laminated structure.

[0347] In addition, as a conductive material having translucency, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene can be used. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing the metal materials can be used. Alternatively, nitrides of the metal materials (for example, titanium nitride) may be used. When using a metal material, an alloy material (or a nitride thereof), it is preferably made thin enough to have translucency. In addition, a laminated film of the above materials can be used as a conductive layer. For example, using a laminated 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 for conductive layers (conductive layers functioning as pixel electrodes or common electrodes, etc.) of light-emitting elements and light-receiving and light-emitting elements.

[0348] 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 oxynitride, silicon nitride, and aluminum oxide.

[0349] [Display Device 100B] FIG. 24 shows a cross-sectional view of the display device 100B.

[0350] The display device 100B mainly differs from the display device 100A in that it has a protective layer 195. For the configurations similar to those of the display device 100A, detailed descriptions are omitted.

[0351] By providing the protective layer 195 that covers the light-emitting element 190B, the light-emitting element 190G, and the light-emitting and receiving element 190MER, it is possible to suppress the entry of impurities such as water into the light-emitting element 190B, the light-emitting element 190G, and the light-emitting and receiving element 190MER, and improve the reliability of the light-emitting element 190B, the light-emitting element 190G, and the light-emitting and receiving element 190MER.

[0352] In the region 228 near the end of the display device 100B, it is preferable that the insulating layer 215 and the protective layer 195 are in contact with each other through the opening of 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 are in contact with each other. Thereby, it is possible to suppress the entry of impurities from the outside into the display unit 162 through the organic insulating film. Therefore, the reliability of the display device 100B can be improved.

[0353] The protective layer 195 may be a single layer or a laminated structure. For example, the protective layer 195 may have 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. At this time, it is preferable that the end of the inorganic insulating film extends outside the end of the organic insulating film.

[0354] Furthermore, a lens may be provided in the region overlapping the light-emitting and receiving element 190MER. Thereby, the sensitivity and accuracy of the sensor using the light-emitting and receiving element 190MER can be improved.

[0355] 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.

[0356] 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 lens. Alternatively, a material containing a resin and nanoparticles of a material having a refractive index higher than that of the resin can be used for the lens. Titanium oxide, zirconium oxide, etc. can be used for the nanoparticles.

[0357] In addition, cerium oxide, hafnium oxide, lanthanum oxide, magnesium oxide, niobium oxide, tantalum oxide, titanium oxide, yttrium oxide, zinc oxide, an oxide containing indium and tin, or an oxide containing indium, gallium, and zinc, etc. can be used for the lens. Alternatively, zinc sulfide, etc. can be used for the lens.

[0358] In the display device 100B, the protective layer 195 and the substrate 152 are bonded together by the adhesive layer 142. The adhesive layer 142 is provided so as to overlap with the light-emitting element 190B, the light-emitting element 190G, and the light-emitting and receiving element 190MER, respectively, and a solid encapsulation structure is applied to the display device 100B.

[0359] [Display device 100C] FIG. 25A shows a cross-sectional view of the display device 100C.

[0360] The structure of the transistors in the display device 100C is different from that of the display device 100B.

[0361] The display device 100C has transistors 208, 209, and 210 on the substrate 151.

[0362] Transistors 208, 209, and 210 each have a semiconductor layer having a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, 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 that functions as a gate insulating layer, a conductive layer 223 that functions as a gate, and an insulating layer 215 that covers 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.

[0363] The conductive layers 222a and 222b are each connected to the low-resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215. One of the conductive layers 222a and 222b functions as a source, and the other functions as a drain.

[0364] The pixel electrode 191 of the light-emitting element 190G is electrically connected to one of the pair of low-resistance regions 231n of the transistor 208 through the conductive layer 222b.

[0365] The pixel electrode 191 of the light-emitting and receiving element 190MER is electrically connected to the other of the pair of low-resistance regions 231n of the transistor 209 through the conductive layer 222b.

[0366] In FIG. 25A, an example in which the insulating layer 225 covers the upper surface and the side surface of the semiconductor layer is shown. On the other hand, in the transistor 202 shown in FIG. 25B, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231 and does not overlap with the low-resistance region 231n. For example, the structure shown in FIG. 25B can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In FIG. 25B, the insulating layer 215 is provided to cover the insulating layer 225 and the conductive layer 223, and the conductive layers 222a and 222b are each connected to the low-resistance region 231n through the opening of the insulating layer 215. Further, an insulating layer 218 that covers the transistor may be provided.

[0367] In addition, the display device 100C is different from the display device 100B in that it does not have the substrates 151 and 152, but has the substrates 153, 154, the adhesive layer 155, and the insulating layer 212.

[0368] The substrate 153 and the insulating layer 212 are bonded together by the adhesive layer 155. The substrate 154 and the protective layer 195 are bonded together by the adhesive layer 142.

[0369] The display device 100C is configured by transferring the insulating layer 212, the transistors 208, 209, 210, the light-emitting and receiving element 190MER, the light-emitting element 190G, etc., formed on the production substrate, onto the substrate 153. The substrates 153 and 154 preferably have flexibility respectively. Thereby, the flexibility of the display device 100C can be enhanced.

[0370] An inorganic insulating film that can be used for the insulating layer 211, the insulating layer 213, and the insulating layer 215 can be used for the insulating layer 212.

[0371] As described above, in the display device of the present embodiment, a light-emitting and receiving element is provided as an alternative to the light-emitting element in a sub-pixel that exhibits any color. By the light-emitting and receiving element also serving as a light-emitting element and a light-receiving element, a light-receiving function can be imparted to a pixel without increasing the number of sub-pixels included in the pixel. Also, a light-receiving function can be imparted to a pixel without reducing the definition of the display device or the aperture ratio of each sub-pixel.

[0372] This embodiment can be implemented in appropriate combination with at least a part of other embodiments described in this specification.

[0373] (Embodiment 3) 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.

[0374] The metal oxide preferably contains at least indium or zinc. Particularly preferably, it contains indium and zinc. In addition to these, it is preferable that it contains aluminum, gallium, yttrium, tin, etc. Further, it may contain one or more selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, etc.

[0375] Further, the metal oxide can be formed by a sputtering method, a chemical vapor deposition (CVD) method such as a metal organic chemical vapor deposition (MOCVD) method, or an atomic layer deposition (ALD) method.

[0376] <Classification of crystal structure> Examples of the crystal structure of the oxide semiconductor include amorphous (including completely amorphous), CAAC (c-axis-aligned crystalline), nc (nanocrystalline), CAC (cloud-aligned composite), single crystal, and poly crystal.

[0377] The crystal structure of the film or substrate can be evaluated using an X-ray diffraction (XRD) spectrum. For example, it can be evaluated using the XRD spectrum obtained by grazing-incidence XRD (GIXD) measurement. Note that the GIXD method is also called the thin film method or the Seemann-Bohlin method.

[0378] For example, in a quartz glass substrate, the shape of the peak in the XRD spectrum is almost symmetric about the left and right. On the other hand, in an IGZO film having a crystal structure, the shape of the peak in the XRD spectrum is asymmetric about the left and right. The fact that the shape of the peak in the XRD spectrum is asymmetric about the left and right indicates the presence of crystals in the film or the substrate. In other words, if the shape of the peak in the XRD spectrum is not symmetric about the left and right, it cannot be said that the film or the substrate is in an amorphous state.

[0379] Also, the crystal structure of the film or the substrate can be evaluated by the diffraction pattern (also referred to as the nano-beam electron diffraction pattern) observed by the nano-beam electron diffraction method (NBED). For example, in the diffraction pattern of a quartz glass substrate, a halo is observed, and it can be confirmed that the quartz glass is in an amorphous state. Further, in the diffraction pattern of an IGZO film formed at room temperature, a spot-like pattern is observed instead of a halo. For this reason, it is presumed that the IGZO film formed at room temperature is in an intermediate state that is neither a crystalline state nor an amorphous state, and it cannot be concluded that it is in an amorphous state.

[0380] [Structure of Oxide Semiconductor] Note that when focusing on the structure, the oxide semiconductor may be classified differently from the above. For example, the oxide semiconductor can be divided into a single crystal oxide semiconductor and other non-single crystal oxide semiconductors. Examples of the non-single crystal oxide semiconductor include the above-mentioned CAAC-OS and nc-OS. Further, the non-single crystal oxide semiconductor includes a polycrystalline oxide semiconductor, an amorphous-like oxide semiconductor (a-like OS), an amorphous oxide semiconductor, and the like.

[0381] Here, the details of the above-mentioned CAAC-OS, nc-OS, and a-like OS will be described.

[0382] [CAAC-OS] CAAC-OS is an oxide semiconductor having a plurality of crystal regions, and the plurality of crystal regions are such that the c-axis is oriented in a specific direction. Here, the specific direction is the thickness direction of the CAAC-OS film, the normal direction of the surface on which the CAAC-OS film is formed, or the normal direction of the surface of the CAAC-OS film. Also, a crystal region is a region having periodicity in the atomic arrangement. When the atomic arrangement is regarded as a lattice arrangement, a crystal region is also a region where the lattice arrangements are aligned. Further, CAAC-OS has a region where a plurality of crystal regions are connected in the a-b plane direction, and this region may have strain. Here, strain refers to a portion where the orientation of the lattice arrangement changes between a region where the lattice arrangements are aligned and another region where the lattice arrangements are aligned in a region where a plurality of crystal regions are connected. That is, CAAC-OS is an oxide semiconductor in which the c-axis is oriented and there is no obvious orientation in the a-b plane direction.

[0383] Each of the plurality of crystal regions is composed of one or more minute crystals (crystals having a maximum diameter of less than 10 nm). When a crystal region is composed of one minute crystal, the maximum diameter of the crystal region is less than 10 nm. Also, when a crystal region is composed of a number of minute crystals, the size of the crystal region may be about several tens of nm.

[0384] Also, in an In-M-Zn oxide (where the element M is one or more selected from aluminum, gallium, yttrium, tin, titanium, etc.), 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, In layer) and a layer containing the element M, zinc (Zn), and oxygen (hereinafter, (M,Zn) layer) are laminated. Here, indium and the element M are mutually substitutable. Thus, the (M,Zn) layer may contain indium. Also, the In layer may contain the element M. Note that the In layer may also contain Zn. The layered structure is observed as a lattice image, for example, in a high-resolution TEM (Transmission Electron Microscope) image.

[0385] When performing structural analysis on a CAAC-OS film using, for example, an XRD apparatus, in an Out-of-plane XRD measurement using θ / 2θ scan, a peak indicating c-axis orientation is detected at 2θ = 31° or in its vicinity. Note that the position (the value of 2θ) of the peak indicating c-axis orientation may vary depending on the type and composition of the metal elements constituting CAAC-OS.

[0386] Also, for example, in the electron diffraction pattern of a CAAC-OS film, a plurality of bright spots (spots) are observed. Note that one spot and another spot are observed at point-symmetric positions with the spot of the incident electron beam transmitted through the sample (also called the direct spot) as the center of symmetry.

[0387] When observing the crystal region from the above specific direction, the lattice arrangement within the crystal region is based on a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be a non-regular hexagon. Also, in the above distortion, there may be a lattice arrangement such as a pentagon or a heptagon. Note that in CAAC-OS, even in the vicinity of the distortion, a clear grain boundary cannot be confirmed. That is, it can be seen that the formation of grain boundaries is suppressed due to the distortion of the lattice arrangement. This is presumably because CAAC-OS can tolerate the distortion due to the fact that the arrangement of oxygen atoms is not dense in the a-b plane direction or the interatomic bond distance changes due to the substitution of metal atoms.

[0388] Note that a crystal structure in which a clear grain boundary is confirmed is called a so-called polycrystal. Grain boundaries can become recombination centers and are likely to cause a decrease in the on-current of a transistor and a decrease in the field-effect mobility due to carrier capture. Therefore, CAAC-OS in which a clear grain boundary is not confirmed is one of the crystalline oxides having a crystal structure suitable for the semiconductor layer of a transistor. Note that for forming CAAC-OS, a configuration having Zn is preferable. For example, In-Zn oxide and In-Ga-Zn oxide are preferable because they can suppress the generation of grain boundaries more than In oxide.

[0389] CAAC-OS is an oxide semiconductor with high crystallinity and no distinct grain boundaries being confirmed. Therefore, it can be said that in CAAC-OS, a decrease in electron mobility due to grain boundaries is less likely to occur. Also, since the crystallinity of an oxide semiconductor may decrease due to impurity incorporation or defect generation, etc., CAAC-OS can also be said to be an oxide semiconductor with few impurities or defects (such as oxygen deficiencies). Therefore, the physical properties of the oxide semiconductor having CAAC-OS are stable. For this reason, the oxide semiconductor having CAAC-OS is heat-resistant and highly reliable. Also, CAAC-OS is stable against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, when using CAAC-OS for an OS transistor, it becomes possible to expand the degree of freedom in the manufacturing process.

[0390] [nc-OS] nc-OS has periodicity in the atomic arrangement in a minute region (for example, a region of 1 nm or more and 10 nm or less, particularly a region of 1 nm or more and 3 nm or less). In other words, nc-OS has minute crystals. Note that since the size of the minute crystals is, for example, 1 nm or more and 10 nm or less, particularly 1 nm or more and 3 nm or less, the minute crystals are also referred to as nano crystals. Also, nc-OS has no regularity in the crystal orientation between different nano crystals. Therefore, no orientation is seen in the entire film. Therefore, depending on the analysis method, nc-OS may not be distinguishable from a-like OS and amorphous oxide semiconductors. For example, when performing structure analysis on an nc-OS film using an XRD apparatus, no peak indicating crystallinity is detected in the Out-of-plane XRD measurement using θ / 2θ scan. Also, when performing electron beam diffraction (also referred to as limited field electron beam diffraction) using an electron beam with a probe diameter larger than the nano crystals (for example, 50 nm or more) on an nc-OS film, a diffraction pattern such as a halo pattern is observed. On the other hand, when performing electron beam diffraction (also referred to as nano beam electron beam diffraction) using an electron beam with a probe diameter close to or smaller than the size of the nano crystals (for example, 1 nm or more and 30 nm or less) on an nc-OS film, an electron beam diffraction pattern in which a plurality of spots are observed within a ring-shaped region centered on a direct spot may be obtained.

[0391] [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 loose or low-density region. That is, the a-like OS has lower crystallinity compared to the nc-OS and the CAAC-OS. Also, the a-like OS has a higher hydrogen concentration in the film compared to the nc-OS and the CAAC-OS.

[0392] [[Constitution of Oxide Semiconductor]] Next, the details of the above-mentioned CAC-OS will be described. Note that the CAC-OS relates to the material constitution.

[0393] [CAC-OS] The CAC-OS is, for example, a constitution of a material in which the elements constituting the metal oxide are unevenly distributed in a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 3 nm or less, or in the vicinity thereof. Hereinafter, in the metal oxide, one or more metal elements are unevenly distributed, and the region having the metal element is in a state of being mixed in a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 3 nm or less, or in the vicinity thereof, which is also referred to as a mosaic state or a patch state.

[0394] Furthermore, the CAC-OS is a constitution in which the material is separated into a first region and a second region to form a mosaic state, and the first region is distributed in the film (hereinafter, also referred to as a cloud state). That is, the CAC-OS is a composite metal oxide having a constitution in which the first region and the second region are mixed.

[0395] Here, the atomic ratios of In, Ga, and Zn to the metal elements constituting the CAC-OS in the In-Ga-Zn oxide are represented 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. Also, 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. Also, 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.

[0396] Specifically, the first region is a region mainly composed of indium oxide, indium zinc oxide, etc., and the second region is a region mainly composed of gallium oxide, gallium zinc oxide, etc. In other words, the first region can be rephrased as a region mainly composed of In, and the second region can be rephrased as a region mainly composed of Ga.

[0397] In addition, there are cases where a clear boundary between the first region and the second region cannot be observed.

[0398] In addition, the CAC-OS in In-Ga-Zn oxide refers to a structure in which some regions mainly composed of Ga and some regions mainly composed of In are arranged randomly in a mosaic pattern in a material structure containing In, Ga, Zn, and O. Therefore, it is presumed that the CAC-OS has a structure in which metal elements are distributed non-uniformly.

[0399] CAC-OS can be formed by a sputtering method, for example, under conditions where the substrate is not intentionally heated. Also, when forming CAC-OS by a sputtering method, any one or more selected from among inert gases (typically argon), oxygen gas, and nitrogen gas may be used as the film-forming gas. Further, the lower the flow rate ratio of oxygen gas to the total flow rate of the film-forming gas during film formation, the more preferable it is. For example, it is preferable that the flow rate ratio of oxygen gas to the total flow rate of the film-forming gas during film formation is 0% or more and less than 30%, preferably 0% or more and 10% or less.

[0400] Also, for example, in CAC-OS in In-Ga-Zn oxide, it can be confirmed by EDX mapping obtained using energy dispersive X-ray spectroscopy (EDX) that a region mainly composed of In (the first region) and a region mainly composed of Ga (the second region) are unevenly distributed and have a mixed structure.

[0401] Here, the first region is a region with higher conductivity compared to the second region. That is, the conductivity as a metal oxide is exhibited by the flow of carriers through the first region. Therefore, when the first region is distributed in a cloud-like manner in the metal oxide, a high field-effect mobility (μ) can be realized.

[0402] On the other hand, the second region is a region with higher insulating properties compared to the first region. That is, by the distribution of the second region in the metal oxide, the leakage current can be suppressed.

[0403] Therefore, when using CAC-OS in a transistor, the conductivity caused by the first region and the insulating property caused by the second region act complementarily, enabling the function of switching (turning on / off) to be imparted to the CAC-OS. That is, CAC-OS has a conductive function in a part of the material and an insulating function in a part of the material, and has a function as a semiconductor in the whole material. By separating the conductive function and the insulating function, both functions can be enhanced to the maximum extent. Therefore, by using CAC-OS in a transistor, a high on-current (I on )、high field-effect mobility (μ), and good switching operation can be realized.

[0404] In addition, a transistor using CAC-OS has high reliability. Therefore, CAC-OS is optimal for various semiconductor devices including display devices.

[0405] Oxide semiconductors have various structures and each has different characteristics. The oxide semiconductor according to one aspect of the present invention may have two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, a-like OS, CAC-OS, nc-OS, and CAAC-OS.

[0406] <Transistor having an oxide semiconductor> Subsequently, the case of using the above oxide semiconductor in a transistor will be described.

[0407] By using the above oxide semiconductor in a transistor, a transistor with high field-effect mobility can be realized. In addition, a highly reliable transistor can be realized.

[0408] For a transistor, it is preferable to use an oxide semiconductor with a low carrier concentration. For example, the carrier concentration of the oxide semiconductor is 1×10 17 cm -3 or less, preferably 1×10 15 cm -3 or less, more preferably 1×10 13 cm -3Hereinafter, more preferably 1×10 11 cm -3 or less, and even more preferably 1×10 10 cm -3 or less, and 1×10 -9 cm -3 or more. In the case of reducing the carrier concentration of the oxide semiconductor film, the impurity concentration in the oxide semiconductor film may be reduced and the density of defect levels may be reduced. In this specification and the like, a low impurity concentration and a low density of defect levels are referred to as high-purity intrinsic or substantially high-purity intrinsic. In addition, an oxide semiconductor having a low carrier concentration may be referred to as a high-purity intrinsic or substantially high-purity intrinsic oxide semiconductor.

[0409] In addition, since an oxide semiconductor film having high-purity intrinsic or substantially high-purity intrinsic has a low density of defect levels, the density of trap levels may also be low.

[0410] In addition, the charge trapped in the trap level of the oxide semiconductor may take a long time to disappear and may behave like a fixed charge. Therefore, a transistor in which a channel formation region is formed in an oxide semiconductor having a high trap level density may have unstable electrical characteristics.

[0411] Therefore, in order to stabilize the electrical characteristics of the transistor, it is effective to reduce the impurity concentration in the oxide semiconductor. In addition, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in the adjacent film. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, silicon, and the like.

[0412] <Impurities> Here, the effects of various impurities in the oxide semiconductor will be described.

[0413] In an oxide semiconductor, when silicon or carbon, which is one of the Group 14 elements, is contained, 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 (the concentration obtained by secondary ion mass spectrometry (SIMS)) are set to 2×10 18 atoms / cm 3 or less, preferably 2×10 17 atoms / cm 3 or less.

[0414] In addition, when an alkali metal or an alkaline earth metal is contained in the oxide semiconductor, defect levels may be formed and carriers may be generated. Therefore, a transistor using an oxide semiconductor containing an alkali metal or an alkaline earth metal tends to have normally-on characteristics. For this reason, the concentration of the alkali metal or the alkaline earth metal in the oxide semiconductor obtained by SIMS is set to 1×10 18 atoms / cm 3 or less, preferably 2×10 16 atoms / cm 3 or less.

[0415] In addition, in an oxide semiconductor, when nitrogen is contained, electrons as carriers are generated, the carrier concentration increases, and it tends to be n-type. As a result, a transistor using an oxide semiconductor containing nitrogen as a semiconductor tends to have normally-on characteristics. Or, when nitrogen is contained in the oxide semiconductor, trap levels 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 less than 5×10 19 atoms / cm 3 , preferably 5×10 18 atoms / cm 3 or less, more preferably 1×10 18 atoms / cm 3 or less, even more preferably 5×10 17 atoms / cm 3 or less.

[0416] In addition, since hydrogen contained in the oxide semiconductor reacts with oxygen bonded to metal atoms to form water, oxygen vacancies may be formed. When hydrogen enters these oxygen vacancies, electrons, which are carriers, may be generated. Also, a part of the hydrogen may bond with oxygen bonded to metal atoms to generate electrons, which are carriers. Therefore, a transistor using an oxide semiconductor containing hydrogen tends to have normally-on characteristics. For this reason, it is preferable that hydrogen in the oxide semiconductor be reduced as much as possible. Specifically, in the oxide semiconductor, the hydrogen concentration obtained by SIMS is less than 1×10 20 atoms / cm 3 less than, preferably less than 1×10 19 atoms / cm 3 less than, more preferably less than 5×10 18 atoms / cm 3 less than, still more preferably less than 1×10 18 atoms / cm 3 less than.

[0417] By using an oxide semiconductor with sufficiently reduced impurities in the channel formation region of a transistor, stable electrical characteristics can be imparted.

[0418] This embodiment can be implemented in appropriate combination with at least some of the other embodiments described in this specification.

[0419] (Embodiment 4) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to FIGS. 26 to 28.

[0420] The electronic device of this embodiment has a display device according to one aspect of the present invention. For example, a display device according to one aspect of the present invention can be applied to the display unit of the electronic device. Since the display device according to one aspect of the present invention has a function of detecting light, biometric authentication can be performed at the display unit, or a touch operation (contact or approach) can be detected. As a result, the functionality and convenience of the electronic device can be enhanced.

[0421] Examples of electronic devices include, for example, relatively large-screen electronic devices such as television sets, desktop or notebook personal computers, monitors for computers, digital signage, and large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, portable information terminals, and audio playback devices.

[0422] The electronic device of the present embodiment may have a sensor (including a function of measuring force, displacement, position, speed, 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).

[0423] The electronic device of the present embodiment can have various functions. For example, it can have functions such as displaying various information (still images, moving images, text images, etc.) on a display unit, a touch panel function, a function of displaying a calendar, date, or time, a function of executing various software (programs), a wireless communication function, and a function of reading programs or data recorded on a recording medium.

[0424] The electronic device 6500 shown in FIG. 26A is a portable information terminal that can be used as a smartphone.

[0425] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508, etc. The display unit 6502 has a touch panel function.

[0426] The display device of one aspect of the present invention can be applied to the display unit 6502.

[0427] FIG. 26B is a schematic cross-sectional view including an end portion of the housing 6501 on the side of the microphone 6506.

[0428] A protective member 6510 having translucency is provided on the display surface side of the housing 6501, and a display panel 6511, an optical member 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.

[0429] On the protective member 6510, the display panel 6511, the optical member 6512, and the touch sensor panel 6513 are fixed by an adhesive layer (not shown).

[0430] In a region outside the display unit 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded-back portion. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on the printed circuit board 6517.

[0431] A flexible display according to an aspect of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. Further, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted while suppressing the thickness of the electronic device. Further, 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, a narrow bezel electronic device can be realized.

[0432] By using a display device according to an aspect of the present invention for the display panel 6511, imaging can be performed by the display unit 6502. For example, a fingerprint can be imaged by the display panel 6511 to perform fingerprint authentication.

[0433] Since the display unit 6502 further has a touch sensor panel 6513, a touch panel function can be imparted to the display unit 6502. As the touch sensor panel 6513, various methods such as a capacitance method, a resistive film method, a surface acoustic wave method, an infrared method, an optical method, and a pressure-sensitive method can be used. Alternatively, the display panel 6511 may function as a touch sensor, and in that case, the touch sensor panel 6513 may not be provided.

[0434] FIG. 27A shows an example of a television apparatus. In the television apparatus 7100, a display unit 7000 is incorporated in a housing 7101. Here, a configuration in which the housing 7101 is supported by a stand 7103 is shown.

[0435] The display device according to an aspect of the present invention can be applied to the display unit 7000.

[0436] The operation of the television apparatus 7100 shown in FIG. 27A can be performed by an operation switch provided in the housing 7101 or a separate remote control operation unit 7111 or the like. Alternatively, the display unit 7000 may be provided with a touch sensor, and the television apparatus 7100 may be operated by touching the display unit 7000 with a finger or the like. The remote control operation unit 7111 may have a display unit for displaying information output from the remote control operation unit 7111. Channel and volume operations can be performed by operation keys or a touch panel provided in the remote control operation unit 7111, and the video displayed on the display unit 7000 can be operated.

[0437] Note that the television apparatus 7100 has a configuration including a receiver and a modem or the like. General television broadcasts can be received by the receiver. Also, by connecting to a communication network by wire or wirelessly via the modem, one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers) information communication is also possible.

[0438] FIG. 27B shows an example of a notebook personal computer. The notebook personal computer 7200 has a housing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, etc. A display unit 7000 is incorporated in the housing 7211.

[0439] The display device according to an aspect of the present invention can be applied to the display unit 7000.

[0440] FIGS. 27C and 27D show an example of digital signage.

[0441] The digital signage 7300 shown in FIG. 27C includes a housing 7301, a display unit 7000, a speaker 7303, etc. Furthermore, it can have an LED lamp, operation keys (including a power switch or an operation switch), connection terminals, various sensors, a microphone, etc.

[0442] FIG. 27D shows a digital signage 7400 attached to a cylindrical column 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of the column 7401.

[0443] In FIGS. 27C and 27D, the display device according to an aspect of the present invention can be applied to the display unit 7000.

[0444] The larger the display unit 7000 is, the more information can be provided at one time. Also, the larger the display unit 7000 is, the more likely it is to catch people's eyes. For example, the advertising effect can be enhanced.

[0445] By applying a touch panel to the display unit 7000, not only can an image or video be displayed on the display unit 7000, but also the user can operate it intuitively, which is preferable. Also, when used for applications such as providing route information or traffic information, the usability can be enhanced by intuitive operation.

[0446] Also, as shown in FIGS. 27C and 27D, it is preferable that the digital signage 7300 or the digital signage 7400 can be linked with an information terminal 7311 or an information terminal 7411 such as a smartphone held by the user through wireless communication. For example, the information of the advertisement displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or the information terminal 7411. Also, by operating the information terminal 7311 or the information terminal 7411, the display on the display unit 7000 can be switched.

[0447] Also, it is possible to execute a game on the digital signage 7300 or the digital signage 7400, using the screen of the information terminal 7311 or the information terminal 7411 as an operation means (controller). As a result, an unspecified number of users can participate in and enjoy the game simultaneously.

[0448] The electronic device shown in FIGS. 28A to 28F includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), connection terminals 9006, a sensor 9007 (including a function of measuring force, displacement, position, speed, 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), a microphone 9008, and the like.

[0449] The electronic device shown in FIGS. 28A to 28F has various functions. For example, it can have a function of displaying various information (such as still images, moving images, text images, etc.) on the display unit, a touch panel function, a function of displaying a calendar, date, or time, etc., a function of controlling processing by various software (programs), a wireless communication function, a function of reading and processing programs or data recorded on a recording medium, and the like. Note that the functions of the electronic device are not limited to these, and it can have various functions. The electronic device may have a plurality of display units. Also, the electronic device may be provided with a camera or the like and have a function of shooting a still image or a moving image and storing it in a recording medium (external or built-in to the camera), a function of displaying the shot image on the display unit, and the like.

[0450] Details of the electronic device shown in FIGS. 28A to 28F will be described below.

[0451] FIG. 28A is a perspective view showing a portable information terminal 9101. The portable information terminal 9101 can be used as, for example, a smartphone. Note that the portable information terminal 9101 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, etc. Further, the portable information terminal 9101 can display characters or image information, etc. on its plurality of surfaces. FIG. 28A shows an example in which three icons 9050 are displayed. Also, information 9051 indicated by a dashed rectangle can be displayed on another surface of the display unit 9001. Examples of the information 9051 include notifications of incoming calls such as e-mail, SNS, and telephone, titles such as e-mail or SNS, sender names, dates and times, battery remaining amounts, antenna reception strengths, etc. Alternatively, an icon 9050 or the like may be displayed at the position where the information 9051 is displayed.

[0452] FIG. 28B is a perspective view showing a portable information terminal 9102. The portable information terminal 9102 has a function of displaying information on three or more surfaces of the display unit 9001. Here, an example in which information 9052, information 9053, and information 9054 are respectively displayed on different surfaces is shown. For example, the user can also check the information 9053 displayed at a position where it can be observed from above the portable information terminal 9102 in a state where the portable information terminal 9102 is stored in the breast pocket of a piece of clothing. The user can check the display without taking the portable information terminal 9102 out of the pocket and can determine, for example, whether to answer a call.

[0453] FIG. 28C is a perspective view showing a wristwatch-type portable information terminal 9200. Also, the display surface of the display unit 9001 is provided to be curved, and display can be performed along the curved display surface. Further, the portable information terminal 9200 can also make a hands-free call by communicating with, for example, a wirelessly communicable headset. Also, the portable information terminal 9200 can perform mutual data transmission with other information terminals and charging by means of the connection terminal 9006. Note that the charging operation may be performed by wireless power supply.

[0454] Figs. 28D to 28F are perspective views showing the foldable mobile information terminal 9201. Fig. 28D shows the mobile information terminal 9201 in the unfolded state, Fig. 28F shows the folded state, and Fig. 28E is a perspective view of the state in the process of changing from one of Fig. 28D and Fig. 28F to the other. The mobile information terminal 9201 has excellent portability in the folded state and excellent display listability due to a seamless wide display area in the unfolded state. The display unit 9001 of the mobile information terminal 9201 is supported by three housings 9000 connected by a hinge 9055. For example, the display unit 9001 can be bent with a curvature radius of 0.1 mm or more and 150 mm or less.

[0455] This embodiment can be implemented by appropriately combining at least a part thereof with other embodiments described in this specification.

Description of Reference Numerals

[0456] REN: Wiring: RS: Wiring: SE: Wiring: AL: Wiring: CL: Wiring: GL: Wiring: TX: Wiring: VCP: Wiring: VPI: Wiring: VRS: Wiring: WX: Wiring: GL1: Wiring: GL2: Wiring: SL1: Wiring: SL2: Wiring: SL3: Wiring: ME, MER: Light-emitting and receiving element: ELB, ELG: Light-emitting element: SW1 to SW3: Switch: Tr1 to Tr2: Transistor: M to M4: Transistor: M10 to M14: Transistor: C1 to C3: Capacitance: CS to CS2: Capacitance: 10: Display device: 11: Display unit: 12 to 14: Driving circuit unit: 15: Circuit unit: 20R, 20G, 20B: Pixel: 21R, 21G, 21B: Circuit: 22: Circuit: 30, 30a, 30B, 30G: Pixel: 40, 40a: Circuit: 41 to 43: Transistor: 50 to 56: Circuit: 61 to 69: Transistor: 71 to 74: Transistor: 81 to 84: Capacitance

Claims

1. A plurality of pixels arranged in a matrix form, One of the pixels has a first sub-pixel, a second sub-pixel, and a third sub-pixel, the first subpixel has a light emitting / receiving element, a first circuit, and a second circuit; the second subpixel has a first light emitting element and a third circuit; the third subpixel has a second light emitting element and a fourth circuit; the first circuit has a function of controlling light emission of the light receiving / emitting element when the light receiving / emitting element is used as a light emitting element; the second circuit has a function of controlling an operation of the light emitting / receiving element when the light emitting / receiving element is used as a light receiving element; the third circuit has a function of controlling light emission of the first light-emitting element; the fourth circuit has a function of controlling light emission of the second light emitting element; the light receiving / emitting element has a function of emitting light of a first color and a function of receiving at least one of light of a second color and light of a third color; the first light-emitting element has a function of emitting light of the second color, The second light-emitting element has a function of emitting light of the third color.

2. A plurality of pixels arranged in a matrix form, One of the pixels has a first sub-pixel, a second sub-pixel, and a third sub-pixel, the first subpixel has a light emitting / receiving element, a first circuit, and a second circuit; the second subpixel has a first light emitting element and a third circuit; the third subpixel has a second light emitting element and a fourth circuit; the first circuit has a function of controlling light emission of the light receiving / emitting element when the light receiving / emitting element is used as a light emitting element; the second circuit has a function of controlling an operation of the light emitting / receiving element when the light emitting / receiving element is used as a light receiving element; the third circuit has a function of controlling light emission of the first light-emitting element, the fourth circuit has a function of controlling light emission of the second light emitting element; the light receiving / emitting element has a function of emitting light of a first color and a function of receiving at least one of light of a second color and light of a third color; the first light-emitting element has a function of emitting light of the second color, the second light-emitting element has a function of emitting light of the third color, the light emitting / receiving element includes a pixel electrode, an active layer having a region located above the pixel electrode, a light emitting layer having a region located above the active layer, and a common electrode having a region located above the light emitting layer; The common electrode has a function as a common electrode for the first light-emitting element and a function as a common electrode for the second light-emitting element.

3. In claim 1 or 2, the second color light has a shorter wavelength than the first color light, A display device, wherein the third color light has a shorter wavelength than the first color light.

Images