Display device

Abstract

To provide a display device with an imaging function, and provide a high-definition imaging device or display device.SOLUTION: A display device has first to third switches, first and second transistors, a capacitor, first and second wires, and a light-receiving element. The first switch has one electrode electrically connected to the first wire and the other electrode electrically connected to a gate of the first transistor and one electrode of the capacitor. The second switch has one electrode electrically connected to one of a source and a drain of the first transistor, one electrode of the light-receiving element, and the other electrode of the capacitor, and has the other electrode electrically connected to a gate of the second transistor and one electrode of the third switch. The third switch has the other electrode electrically connected to the second wire. The light-receiving element has a function of emitting light with a first color and a function of receiving light with a second color.SELECTED DRAWING: Figure 4

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. In addition, in information terminal devices such as smartphones, tablet terminals, and notebook PCs (personal computers), display devices are required to consume less power in addition to having higher definition. Furthermore, there is a demand for display devices with various functions added, such as a function as a touch panel and 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 made thin and lightweight, 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 having a high-definition display unit or imaging unit as one of the problems. One aspect of the present invention is to provide an imaging device or a display device capable of imaging 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 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 functioning 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 having a first to third switch, a first transistor, a second transistor, a capacitor, a first wiring, a second wiring, and a light-emitting and light-receiving element. One electrode of the first switch is electrically connected to the first wiring, and the other electrode is electrically connected to the gate of the first transistor and one electrode of the capacitor. One electrode of the second switch is electrically connected to one of the source and drain of the first transistor, one electrode of the light-emitting and light-receiving element, and the other electrode of the capacitor, and the other electrode is electrically connected to the gate of the second transistor and one electrode of the third switch. The other electrode of the third switch is electrically connected to the second wiring. 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.

[0010] Also, in the above, in the first period, it is preferable that the first switch, the second switch, and the third switch are in a conductive state, a data potential is applied to the first wiring, and a first potential is applied to the second wiring. Further, in the second period, it is preferable that the second switch and the third switch are in a conductive state, and a second potential is applied to the second wiring. Further, it is preferable that the second potential is lower than the first potential.

[0011] Also, in the above, it is preferable to further have a fourth switch. At this time, it is preferable that one electrode of the fourth switch is electrically connected to one electrode of the second switch, and the other electrode is electrically connected to one electrode of the light-emitting and light-receiving element. Alternatively, it is preferable that one electrode of the fourth switch is electrically connected to one of the source and drain of the first transistor, and the other electrode is electrically connected to one electrode of the light-emitting and light-receiving element.

[0012] Another aspect of the present invention is a display device including a first to sixth transistors, a capacitor, a light-emitting and light-receiving element, a first wiring, and a second wiring. One of the source and drain of the first transistor is electrically connected to one electrode of the light-emitting and light-receiving element. 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. One of the source and drain of the fourth transistor is electrically connected to the gate of the second transistor, and the other of the source and drain is electrically connected to the second wiring. One of the source and drain of the fifth transistor is electrically connected to one of the source and drain of the second transistor. One of the source and drain of the sixth transistor is electrically connected to one electrode of the light-emitting and light-receiving element, and the other is electrically connected to the gate of the second transistor. One electrode of the capacitor is electrically connected to the gate of the first transistor, and the other electrode is electrically connected to one of the source and drain of the first transistor. 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.

[0013] In addition, in the above, it is preferable to further include a seventh transistor. At this time, the seventh transistor preferably has a function of controlling conduction between one of the source and drain of the first transistor and one electrode of the light-emitting and light-receiving element.

[0014] Another aspect of the present invention is a display device including a first to fifth transistors, an eighth transistor, a capacitor, a light-emitting and light-receiving element, a first wiring, and a second wiring. One of the source and drain of the first transistor is electrically connected to one of the source and drain of the eighth transistor and the gate of the second 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. One of the source and drain of the fourth transistor is electrically connected to the gate of the second transistor, and the other of the source and drain is electrically connected to the second wiring. One of the source and drain of the fifth transistor is electrically connected to one of the source and drain of the second transistor. The other of the source and drain of the eighth transistor is electrically connected to one of the electrodes of the light-emitting and light-receiving element. One electrode of the capacitor is electrically connected to the gate of the first transistor, and the other electrode is electrically connected to one of the source and drain of the first transistor. 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.

[0015] Also, in any of the above, it is preferable to further include a third wiring. At this time, it is preferable that the other of the source and drain of the fifth transistor is electrically connected to the third wiring.

[0016] Alternatively, in any of the above, it is preferable that the other of the source and drain of the fifth transistor is electrically connected to the first wiring.

[0017] Also, in any of the above, in the first period, it is preferable that a data potential is applied to the first wiring and a first potential is applied to the second wiring. In the second period, it is preferable that a second potential is applied to the second wiring. At this time, it is preferable that the second potential is lower than the first potential.

[0018] In addition, in any of the above, it is preferably further provided with a light-emitting element. At this time, the light-emitting element preferably has a function of emitting light of a second color. Furthermore, it is preferable that the light-receiving and emitting element and the light-emitting element are provided on the same plane.

[0019] In addition, in the above, it is preferable that the light-receiving and emitting element has a first pixel electrode, a first light-emitting layer, an active layer, and a first electrode, and the light-emitting element has a second pixel electrode, a second light-emitting layer, and a first electrode. Furthermore, it is preferable that the first pixel electrode and the second pixel electrode are formed by processing the same conductive film.

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

[0021] Another aspect of the present invention is an electronic device including 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. Alternatively, an imaging device or a display device having a high-definition display unit or imaging unit can be provided. Alternatively, an imaging device or a display device capable of capturing a high-definition image can be provided. Alternatively, an imaging device or a display device capable of performing high-sensitivity imaging can be provided. Alternatively, a display device capable of acquiring biometric information such as fingerprints can be provided. Alternatively, a display device functioning as a touch panel can be provided.

[0023] In addition, according to one aspect of the present invention, the number of components of an electronic device can be reduced. Alternatively, a display device, an imaging device, or an electronic device having a novel configuration can be provided. Alternatively, 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 preclude 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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MODE 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 is 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 construed as being limited to the description of the following embodiments.

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

[0028] In each of the figures described in this specification, the size of each component, the thickness of the layer, or the area may be exaggerated for clarity. Therefore, it is not necessarily limited to that scale.

[0029] The ordinal numbers such as "first" and "second" in this specification are attached to avoid confusion of components and do not numerically limit them.

[0030] A transistor is a type of semiconductor device and can realize operations such as amplification of current or voltage, and switching operations for controlling conduction or non - conduction. The transistors in this specification include IGFETs (Insulated Gate Field Effect Transistors) and thin - film transistors (TFTs: Thin Film Transistors).

[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 a circuit operation. Therefore, in this specification, the terms "source" and "drain" are assumed to be interchangeable.

[0032] In addition, in this specification and the like, "electrically connected" includes cases where connection is made through "something having some electrical effect". Here, "something having some electrical effect" is not particularly limited as long as it enables the transfer of electrical signals between the connection targets. For example, "something having some electrical effect" includes electrodes, wiring, switching elements such as transistors, resistance elements, coils, capacitance elements, and other elements having various functions.

[0033] Note that in this specification and the like, a node refers to an element (such as wiring) that enables electrical connection of elements constituting a circuit. Therefore, "the node to which A is connected" refers to the wiring that is electrically connected to A and can be regarded as having the same potential as A. Note that even if one or more elements enabling electrical connection (such as switches, transistors, capacitance elements, inductors, resistance elements, diodes, etc.) are arranged in the middle of the wiring, as long as it can be regarded as having the same potential as A, that wiring is the node to which A is connected.

[0034] 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 the light-emitting layer.

[0035] In this specification and the like, a display panel, which is one aspect of a display device, has a function of displaying (outputting) an image or the like on a display surface. Therefore, the display panel is one aspect of an output device.

[0036] In addition, in this specification and the like, a display panel in which a connector such as an FPC (Flexible Printed Circuit) or a TCP (Tape Carrier Package) is attached to the substrate of the display panel, or an IC is mounted on the substrate by a COG (Chip On Glass) method or the like may be referred to as a display panel module, a display module, or simply a display panel.

[0037] 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, for example, a finger, a stylus, or other detected object touching, pressing, or approaching the display surface. Therefore, the touch panel is an aspect of an input / output device.

[0038] 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.

[0039] Also, in this specification and the like, a touch panel substrate on which a connector, an IC, etc. are mounted may be referred to as a touch panel module, a display module, or simply a touch panel.

[0040] (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.

[0041] One aspect of the present invention is a display device having a plurality of pixels arranged in a matrix. Each pixel has one or more sub-pixels. Each sub-pixel has one or more light emitting and receiving elements.

[0042] The light emitting and receiving element (light emitting and 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 receiving element can also be referred to as a multifunctional element, a multifunctional diode, a light emitting photodiode, or a bidirectional photodiode.

[0043] 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.

[0044] [Configuration Example 1] [Configuration Example 1-1] 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 SA. Further, the pixel circuit preferably has a capacitor CS1 and a capacitor CS2 as capacitors for holding charges. In addition, a wiring SL, a wiring VL1, a wiring AL, a wiring CL, a wiring VCP, a wiring VPI, and a wiring WX are connected to the pixel circuit.

[0045] The switch SW1, the switch SW2, and the switch SW3 each have two terminals (electrodes) and are elements capable of controlling conduction and non-conduction between the terminals.

[0046] One terminal of the switch SW1 is electrically connected to the wiring SL, and the other terminal 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, one electrode of the light-emitting and light-receiving element SA, and the other electrode of the capacitor CS1. The other terminal of the switch SW2 is electrically connected to the gate of the transistor Tr2, one terminal of the switch SW3, and one electrode of the capacitor CS2. The other terminal of the switch SW3 is electrically connected to the wiring VL1. The other electrode of the capacitor CS2 is electrically connected to the wiring VCP. One of the source and drain of the transistor Tr2 is electrically connected to the wiring WX, and the other is electrically connected to the wiring VPI. The other electrode of the light-emitting and light-receiving element SA is electrically connected to the wiring CL.

[0047] The wiring VCP and the wiring VPI are preferably given a fixed potential. As the fixed potential, the potential VDD, the potential VSS, the ground potential, the reference potential, or the common potential can be used.

[0048] In FIG. 1, the anode of the light-emitting and receiving element SA is configured to be located on the transistor Tr1 side. At this time, the potential applied to the wiring CL can be lower than the potential applied to the wiring AL. Note that the cathode of the light-emitting and receiving element SA may be configured to be located on the transistor Tr1 side, and in that case, the wiring CL can be configured to have a potential higher than that of the wiring AL.

[0049] In addition, 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. may be appropriately changed according to the type of the transistor.

[0050] The transistor Tr1 has a function of controlling the current flowing through the light-emitting and receiving element SA. That is, the transistor Tr1 functions as a driving transistor. The transistor Tr1 can control the current flowing through the light-emitting and receiving element SA according to the potential (data potential) applied from the wiring SL via the switch SW1. The light-emitting and receiving element SA can emit light with a luminance corresponding to the current.

[0051] The conduction state of the transistor Tr2 changes according to the charge (potential) transferred to the node to which the gate of the light-emitting and receiving element SA is connected. The transistor Tr2 functions as a reading transistor. Also, the wiring WX functions as a reading wiring.

[0052] At least two types of potentials are applied to the wiring VL1. One is the potential V 0 which is the potential applied to the source of the transistor Tr1 when writing the data potential to the gate of the transistor Tr1. The other is the potential V RSThis is a potential for resetting (initializing) the potential of the node to which the anode of the light-emitting and receiving element SA is connected. By supplying two types of potentials through a single wiring VL1 in this way, the number of wirings can be reduced and the circuit configuration can be simplified. As a result, it becomes possible to reduce the occupied area of the pixel, and a display device with high definition can be realized. Therefore, not only can an image with high display quality be displayed, but also a high-definition image can be captured.

[0053] Hereinafter, the operation method of the pixel circuit illustrated in FIG. 1 will be described.

[0054] First, with reference to FIGS. 2A and 2B, an example of the operation method when the light-emitting and receiving element SA is used as a light-emitting element will be described.

[0055] FIG. 2A schematically shows the operation during the period (data writing period) when the data potential V data is written to the gate of the transistor Tr1. During the data writing period, all of the switches SW1, SW2, and SW3 are turned on.

[0056] During the data writing period, as indicated by one of the dashed arrows, the data potential V data is applied to the gate of the transistor Tr1 from the wiring SL through the switch SW1. Also, as indicated by the other dashed arrow, the potential V 0 is applied to the other of the source and drain of the transistor Tr1 from the wiring VL1 through the switches SW2 and SW3. At this time, the potential difference between the data potential V data and the potential V 0 is charged in the capacitor CS1.

[0057] Figure 2B schematically 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 and receiving element SA emits light according to the current flowing through transistor Tr1. During the holding and light-emitting period, all of switch SW1, switch SW2, and switch SW3 are turned off. As a result, almost all of the current flowing through transistor Tr1 flows through the light-emitting and receiving element SA. In Figure 2B, the current path is indicated by a dashed arrow.

[0058] Subsequently, with reference to FIGS. 3A to 3C, an example of an operation method when the light-emitting and receiving element SA is used as a light-receiving element will be described.

[0059] Figure 3A schematically shows the operation during the period (reset period) for initializing the potential of the anode of the light-emitting and receiving element SA. During the reset period, all of switch SW1, switch SW2, and switch SW3 are turned on.

[0060] During the reset period, as indicated by one of the dashed arrows, the potential V is applied to the anode of the light-emitting and receiving element SA from the wiring VL1 via the switch SW3 and the switch SW2. RS The potential V RS is set to a potential lower than at least the potential applied to the wiring CL. The potential V RS is preferably set to a potential lower than the potential V 0 .

[0061] In the case of a configuration in which the cathode of the light-emitting and receiving element SA is connected to the transistor Tr1 side, the potential V RS may be set to a potential higher than the potential applied to the wiring CL (the potential applied to the anode of the light-emitting and receiving element SA). Also, the potential V RS can be set to a potential higher than the potential V 0 .

[0062] Also, during the reset period, the potential V is applied to the gate of the transistor Tr1 from the wiring SL via the switch SW1. off The potential V offis the potential that makes the transistor Tr1 in a non-conducting state. This can prevent the potential of the anode of the light-receiving and emitting element SA from changing unintentionally due to the current flowing from the wiring AL to the light-receiving and emitting element SA through the transistor Tr1 in the subsequent period. For example, the potential V off is the potential V RS can be set to a potential lower than the potential obtained by adding the threshold voltage of the transistor Tr1 to the potential V off is the potential V RS is preferably set to a potential lower than the potential V

[0063] Figure 3B schematically shows the operation during the period (exposure period) when the light-receiving and emitting element SA receives light and charges are accumulated in the light-receiving and emitting element. During the exposure period, charges are accumulated at both ends of the light-receiving and emitting element SA, causing the potential difference Vc between the anode and cathode of the light-receiving and emitting element SA to change.

[0064] During the exposure period, all of the switches SW1, SW2, and SW3 are set to the non-conducting state. Also at this time, since the potential V off applied during the reset period is held at the gate of the transistor Tr1, as shown in the figure, no current flows through the transistor Tr1. Therefore, it is possible to prevent the charges accumulated on the anode side of the light-receiving and emitting element SA from flowing out to the transistor Tr1 and the transistor Tr2 sides. As a result, high-precision imaging can be performed.

[0065] Figure 3C schematically shows the operation during the period (transfer period) when the charges accumulated in the light-receiving and emitting element SA are transferred to the node to which the gate of the transistor Tr2 is connected. During the transfer period, the switch SW2 is set to the conducting state, and the switches SW1 and SW3 are set to the non-conducting state. As a result, as indicated by the dashed arrow, the charges accumulated in the light-receiving and emitting element SA are transferred to the node to which the gate of the transistor Tr2 is connected through the switch SW2. After the transfer of the charges is completed, by setting the switch SW2 to the non-conducting state, the potential of the gate of the transistor Tr2 is held. At this time, a current I corresponding to the gate potential of the transistor Tr2S flows from wiring VPI to wiring WX.

[0066] In this way, by switching the potential applied to wiring VL1 between the data writing period for display and the reset period for imaging, the number of wirings can be reduced and the pixel circuit can be simplified. Therefore, it becomes easier to increase the definition and resolution of the display device. Also, by reducing the number of wirings, the power consumption of the display device can be reduced.

[0067] 〔Configuration Example 1-2〕 FIG. 4A shows a configuration example of a pixel circuit different from FIG. 1 above. In FIG. 4A, it is mainly different from the above in that it has switch SW4.

[0068] Switch SW4 is provided between the light-emitting and receiving element SA and the transistor Tr1, and can control their conduction and non-conduction. Also, in FIG. 4A, one terminal (electrode) of switch SW4 is electrically connected to the other of the source and drain of transistor Tr1, one terminal of switch SW2, and the other electrode of capacitor CS1.

[0069] By setting switch SW4 to the non-conductive state, the light-emitting and receiving element SA and the transistor Tr1 can be electrically insulated. Therefore, regardless of the gate potential of the transistor Tr1, the current flowing through the light-emitting and receiving element SA via the transistor Tr1 can be blocked. As a result, in the reset period and the like exemplified above, it is not necessary to apply potential V off to the gate of the transistor Tr1, so the driving method can be simplified.

[0070] Also, switch SW4 may be provided at the position shown in FIG. 4B. Specifically, one terminal of switch SW2 is electrically connected between the light-emitting and receiving element SA and switch SW4.

[0071] At this time, during the exposure period and the transfer period, the gate of the transistor Tr1 can also be in a state where the data potential is held. As a result, after the transfer period ends, by switching the switch SW4 from the non-conductive state to the conductive state and switching the switch SW2 from the conductive state to the non-conductive state, the light-emitting element SA can be immediately caused to emit light without newly writing data. Thereby, since a data writing period is not required between the completion of the transfer period and the display of the image, the period during which the image is not displayed (non-display period) can be shortened, and it is possible to prevent the display quality from being impaired.

[0072] Further, FIG. 4C shows an example in which the switch SW2 in the configuration of FIG. 4A is eliminated. By adopting a configuration in which the switch SW4 also serves as the function of the switch SW2, the pixel circuit can be simplified.

[0073] [Configuration Example 2] [Configuration Example 2-1 of the Display Device] Hereinafter, a more specific configuration example of the display device according to an aspect of the present invention will be described.

[0074] FIG. 5 shows a block diagram for explaining the configuration of the display device 10. The 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.

[0075] The display unit 11 includes a plurality of pixels 30 arranged in a matrix. The pixel 30 includes a sub-pixel 20R, a sub-pixel 20G, and a sub-pixel 20B. The sub-pixel 20R has a light-emitting and receiving element, and the sub-pixels 20G and 20B each have a light-emitting element.

[0076] Wiring SL1, wiring GL, wiring RS, wiring SE, wiring WX, etc. are electrically connected to the sub-pixel 20R. Wiring SL2 and wiring GL, etc. are electrically connected to the sub-pixel 20G. Wiring SL3 and wiring GL, etc. are electrically connected to the sub-pixel 20B.

[0077] The wiring SL1, wiring SL2, and wiring SL3 are each electrically connected to the drive circuit section 12. The wiring GL is electrically connected to the drive circuit section 13. 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, wiring SL2, and 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.

[0078] The wiring RS and wiring SE are each electrically connected to the drive circuit section 14. The wiring WX is electrically connected to the circuit section 15. 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, 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 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 for supplying to one or both of the wiring REN and 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.

[0079] 〔Configuration Example 2-1 of Pixel〕 FIG. 6 shows an example of a circuit diagram of the pixel 30. The pixel 30 has a sub-pixel 20R, a sub-pixel 20G, and a sub-pixel 20B. The sub-pixel 20R has a circuit 21R, a circuit 22, a light-emitting and receiving element SR, and a transistor M10. The sub-pixel 20G has a circuit 21G and a light-emitting element ELG. The sub-pixel 20B has a circuit 21B and a light-emitting element ELB.

[0080] The circuit 21R has a transistor M1, a transistor M2, a capacitor C1, etc. The circuit 22 has a transistor M11, a transistor M12, a transistor M13, a transistor M14, a capacitor C2, etc.

[0081] When the light-emitting and receiving element SR 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 SR. The circuit 21R has a function of controlling the current flowing through the light-emitting and receiving element SR according to the data potential supplied from the wiring SL1.

[0082] Also, when the light-emitting and receiving element SR is used as a light-receiving element, the circuit 22 functions as a sensor circuit for controlling the operation of the light-emitting and receiving element SR. The circuit 22 has functions of applying a reverse bias voltage to the light-emitting and receiving element SR, controlling the exposure period of the light-emitting and receiving element SR, holding the potential based on the charge transferred from the light-emitting and receiving element SR, and outputting a signal based on the potential to the wiring WX.

[0083] The sub-pixel 20R shown in FIG. 6 corresponds to the configuration illustrated in FIG. 4B. The transistor M2 corresponds to the transistor Tr1 in FIG. 4B, and the transistor M13 corresponds to the transistor Tr2. Similarly, the transistor M1 corresponds to the switch SW1, the transistor M11 corresponds to the switch SW2, the transistor M12 corresponds to the switch SW3, and the transistor M10 corresponds to the switch SW4, respectively.

[0084] For the transistor M1, the gate is electrically connected to the wiring GL, one of the source and the drain is electrically connected to the wiring SL1, and the other is electrically connected to the gate of the transistor M2 and one electrode of the capacitor C1. For the transistor M2, one of the source and the drain is electrically connected to the wiring AL, and the other is electrically connected to one of the source and the drain of the transistor M10 and the other electrode of the capacitor C1. For the transistor M10, the gate is electrically connected to the wiring REN, and the other of the source and the drain is electrically connected to one electrode of the light-emitting and receiving element SR. For the light-emitting and receiving element SR, the other electrode is electrically connected to the wiring CL.

[0085] A data potential is applied to wiring SL1. An anode potential is applied to wiring AL. A cathode potential is applied to wiring CL. In the configuration shown in FIG. 6, the anode potential is set to a potential higher than the cathode potential. A signal for controlling conduction and non-conduction of transistor M10 is applied to wiring REN.

[0086] For transistor M11, its gate is electrically connected to wiring TX, one of its source and drain is electrically connected to one electrode of light-emitting and receiving element SR and the other of the source and drain of transistor M10, 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. For transistor M12, its gate is electrically connected to wiring RS, and the other of its source and drain is electrically connected to wiring VL1. For capacitor C2, its other electrode is electrically connected to wiring VCP. For transistor M13, one of its source and drain is electrically connected to wiring VPI, and the other is electrically connected to one of the source and drain of transistor M14. For transistor M14, its gate is electrically connected to wiring SE, and the other of its source and drain is electrically connected to wiring WX.

[0087] A signal for controlling conduction and non-conduction of transistor M11 is applied to wiring TX. Potentials V 0 and V RS are applied during different periods. A fixed potential is applied to wiring VCP. A fixed potential is applied to wiring VPI. In the configuration shown in FIG. 6, the potential V RS applied to wiring VL1 is preferably lower than the cathode potential applied to wiring CL.

[0088] Transistor M14 functions as a selection transistor for reading. Conduction and non-conduction of transistor M14 are controlled by the signal applied to wiring SE. By setting transistor M14 to the conductive state, transistor M13 and wiring WX can be made conductive, and a current (or voltage) corresponding to the gate potential of transistor M13 can be output to wiring WX.

[0089] Here, for the transistors M1, 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 in which the channel is formed can be preferably used. Also, by applying transistors using an oxide semiconductor to the transistors M2 and M13, all the transistors can be formed through a common manufacturing process, which is preferable. Note that for the transistors M2 and M13, silicon (including amorphous silicon, polycrystalline silicon, and single crystal silicon) may be applied to the semiconductor layer in which the channel is formed. Note that this is not restrictive, and transistors using silicon can also be used for some or all of the transistors. Further, for some or all of the transistors, transistors using inorganic semiconductors, compound semiconductors, organic semiconductors, etc. other than silicon may be used.

[0090] 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. The circuit 21G and the circuit 21B have the same configuration.

[0091] The circuits 21G and 21B include transistors M1, M2, M3, and a capacitor C1. The circuits 21G and 21B are the same as the above-described circuit 21R except for including the transistor M3. The gate of the transistor M3 is electrically connected to the wiring GL, and one of the source and the drain is electrically connected to the other electrode of the capacitor C1, the other of the source and the drain of the transistor M2, and the anode of the light-emitting element ELG or the light-emitting element ELB, and the other is electrically connected to the wiring V0L.

[0092] A fixed potential is applied to the wiring V0L. For example, the same potential as the potential V applied to the wiring VL1 may be applied to the wiring V0L. Also, the wiring VL1 may be used instead of the wiring V0L. 0 ​

[0093] Here, as shown in FIG. 7A, a configuration in which a transistor having a back gate is applied to each transistor may be adopted. FIG. 7A shows a configuration in which a pair of gates are electrically connected.

[0094] Note that, in FIG. 7A, 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 gate 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. 7B, 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. 7B can be preferably used for the transistors M2, M12, and M13 in the pixel 30.

[0095] Also, although an example in which all the transistors have back gates has been shown here, the present invention is not limited to this, and transistors having back gates and transistors not having back gates may be mixed.

[0096] 〔Example configuration of pixel 2-2〕 FIG. 8A shows an example in the case where the transistor M10 in the sub-pixel 20R illustrated in FIG. 6 above is omitted. The configuration shown in FIG. 8A corresponds to the configuration illustrated in FIG. 1.

[0097] Also, FIG. 8B shows an example in the case where a transistor having a back gate is applied to each transistor in FIG. 8A. Here, transistors to which a pair of gates are connected are applied to all the transistors. Note that, as described above, the connection method of the back gate is not limited to this. Also, as described above, transistors not having back gates and transistors having back gates may be mixed.

[0098] 〔Configuration Example 2-3 of Pixel〕 FIG. 9A shows an example in the case where the wiring WX is omitted in the sub-pixel 20R illustrated in FIG. 6 above.

[0099] In FIG. 9A, for the transistor M14, the other of the source and the drain is electrically connected to the wiring SL1.

[0100] The wiring SL1 can also serve as the wiring WX. Specifically, by bringing the transistor M14 into a conductive state, a current (or voltage) corresponding to the gate potential of the transistor M13 can be output to the wiring SL1. At this time, the wiring SL1 can be configured to be connected to both the drive circuit unit 12 and the circuit unit 15.

[0101] FIG. 9B shows an example in the case where the transistor M10 in FIG. 9A is omitted.

[0102] 〔Configuration Example 2-2 of Display Device〕 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.

[0103] FIG. 10A shows an example of an arrangement method for 3×3 pixels. In FIG. 10A, the 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.

[0104] In FIG. 10A, the pixel 30G and the pixel 30B are alternately arranged in the row direction and the column direction. The pixel 30G has the sub-pixel 20R and the sub-pixel 20G. The pixel 30B has the sub-pixel 20R and the sub-pixel 20B.

[0105] For example, for the pixel 30G located at the i-th row and j-th column, the wiring GL[i], the wiring RS[i], and the wiring SE[i] extending in the row direction and the wiring SL1[j], the wiring SL2[j], and the wiring WX[j] extending in the column direction are connected.

[0106] Figure 10B shows an example of the arrangement method of the light-receiving and emitting element SR, the light-emitting element ELG, and the light-emitting element ELB. The light-receiving and emitting elements SR are arranged at equal intervals in the row direction and the column direction. Also, the light-emitting elements ELG and ELB are alternately arranged in the row direction and the column direction, respectively. Further, the shape of each of the light-receiving and emitting element SR, the light-emitting element ELG, and the 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 the light-emitting elements and the light-receiving and emitting elements are separately manufactured, they can be manufactured with a good yield.

[0107] Figure 11 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 20R, 20G, and 20B, the above-described FIG. 6 and the like can be cited.

[0108] [Example of driving method 1] Hereinafter, an example of a driving method of the display device will be described. Here, a configuration in which one pixel has two sub-pixels, as exemplified in FIGS. 10 and 11 above, will be described as an example.

[0109] In the following, the display device is assumed to have 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 the display unit.

[0110] FIGS. 12 and 13 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 the light-emitting elements and the light-receiving and emitting elements, and a period (imaging period) in which imaging is performed using the light-receiving and emitting elements (also referred to as sensors). The display period is a period in which image data is written to the pixels and display based on the image data is performed. The imaging period is a period in which imaging by the light-receiving and emitting elements and reading of imaging data are performed.

[0111] First, the operation in the display period will be described with reference to FIG. 12.

[0112] During the display period, the operation of writing data to the pixels is repeated. During this period, it is assumed that the sensor does not operate (denoted as blank). Note that the imaging operation can also be performed during the display period.

[0113] In one write operation, image data for one frame is written. As shown in FIG. 12, in one write operation (denoted as write), data is sequentially written to the pixels from the first column to the M-th column.

[0114] FIG. 12 shows a timing chart for the write operations of the data in the i-th row and the (i + 1)-th row. Here, the potential transitions in the wirings GL[i], GL[i + 1], RS[i], RS[i + 1], SE, REN, VL1, SL1[j], and SL2[j] are shown. Here, for the wiring SE, the wirings from the first row to the M-th row are collectively denoted as SE[1:M]. Regarding the connection relationship between each wiring and each pixel, FIGS. 10 and 11 can be referred to.

[0115] During the write period of the i-th row, the wirings GL[i] and RS[i] are set to the high-level potential, and the other wirings GL and RS are set to the low-level potential. Also, the image data D R [i, j] is given to the wiring SL1[j], and the image data D G [i, j] is given to the wiring SL2[j], respectively. Also, during the write period, a high-level potential is given to the wiring REN, and a potential V 0 is given to the wiring VL1.

[0116] For the writes after the (i + 1)-th row, in the same manner as above, by setting the corresponding wirings GL and RS to the high-level potential and giving image data to the wirings SL1 and SL2, respectively, the write can be performed row by row.

[0117] By performing such write operations from the first row to the M-th row, the data write for one frame is completed. During the display period, a moving image can be displayed by repeatedly executing the above operations.

[0118] Next, the operation during the imaging period will be described with reference to FIG. 13. Here, the case of performing the imaging operation in the global shutter method will be described. Note that the driving method of the rolling shutter method can also be applied, not limited to the global shutter method.

[0119] The imaging period is divided into a period in which imaging is performed simultaneously at each pixel (referred to as imaging. Hereinafter, in order to distinguish it from the imaging period, it is also referred to as the imaging operation period) and a period in which imaging data is read out in order (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 line by line from the first line to the M-th line.

[0120] FIG. 13 shows a timing chart in the imaging operation period and the readout period. Here, the potential transitions of the wiring TX, the wiring SE[i], the wiring RS[i], the wiring SE[i + 1], the wiring RS[i + 1], the wiring VL1, the wiring REN, the wiring SL[1:N], the wiring GL[1:M], and the wiring WX[1:N] are shown. Here, the wiring GL is collectively denoted as the wiring GL[1:M], and the wiring WX is collectively denoted as the wiring WX[1:N]. Also, the wiring SL1, the wiring SL2, etc. are collectively denoted as the wiring SL[1:N].

[0121] In the initialization period, the wiring REN is set to a low-level potential. As a result, the transistor M10 is in a non-conductive state at all pixels. Thereby, the light-emitting and receiving element SR and the transistor M2 can be electrically insulated.

[0122] The wiring TX and all the wiring RS are set to a high-level potential, and by applying the potential V RS to the node to which the gate of the transistor M13 is connected and the anode of the light-emitting and receiving element SR, the potential V RS is applied from the wiring VL1 via the transistors M11 and M12. Thereby, the reset operation of all pixels is performed.

[0123] Subsequently, during the exposure period, the wiring TX and the wiring RS are set to a low level potential. As a result, charges corresponding to the irradiated light are accumulated in the light emitting and receiving element SR.

[0124] 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 SR can be transferred to the node to which the gate of the transistor M13 is connected. Thereafter, by setting the wiring TX to a low level potential, the potential of the node is maintained.

[0125] Subsequently, imaging data is read out row by row. During the readout period, by sequentially applying a high level potential from the wiring SE[1] to the wiring SE[N], data can be read out for all pixels. For example, in the readout of the i-th row, by setting the wiring SE[i] to a high level potential, the data D W [i] of the i-th row is output to the wiring WX[1:N]. Specifically, for one wiring WX[j], the data D W [i,j] of the i-th row and j-th column is output.

[0126] In FIG. 13, in the readout operation of the data of the i-th row, a high level potential is applied to the wiring SE[i], and after the data D W [i] is output to the wiring WX[1:N], a high level potential is applied to the wiring RS[i]. As a result, the data in the state where the potential V RS which is the reset potential is applied to the gate of the transistor M13 is output to the wiring WX[1:N]. The circuit unit 15 to which the wiring WX is connected can perform correlated double sampling (CDS) using these two output data, and can reduce the influence of variations in the electrical characteristics of each pixel.

[0127] Here, during the imaging period, a low-level potential is constantly applied to the wiring REN. As a result, particularly during the exposure period and the transfer period, the light-emitting and light-receiving element SR and the transistor M2 are electrically insulated. This reduces noise and enables high-precision imaging.

[0128] Also, during the imaging period, each pixel preferably assumes a state (referred to as "holding") in which it holds the image data written immediately before. As a result, when the imaging period ends and the potential of the wiring REN changes from the low-level potential to the high-level potential, an image corresponding to the immediately held image data can be displayed. Further, by holding the image data written in the sub-pixel 20G or the sub-pixel 20B during the imaging period, crosstalk noise to the anode of the light-emitting and light-receiving element SR in the sub-pixel 20R can be reduced.

[0129] The above is the description of the driving method example 1.

[0130] [Configuration Example 3] Hereinafter, a configuration example of a display device having a configuration different from the above will be described.

[0131] [Configuration Example 3-1 of Pixel] In the pixel circuit shown in FIG. 14A, in the configuration exemplified in FIG. 6 and the like, the transistor M11 and the capacitor C2 are omitted.

[0132] In FIG. 14A, the other of the source and drain of the transistor M2 is electrically connected to one of the source and drain of the transistor M10, one of the source and drain of the transistor M12, and the gate of the transistor M13. The other of the source and drain of the transistor M10 is electrically connected to the anode of the light-emitting and light-receiving element SR.

[0133] With such a configuration, the transistor M10 can also function as the transistor M11 in the configuration shown in FIG. 6 and the like. Therefore, since the transistor M11 and the wiring TX can be omitted, the pixel configuration can be simplified.

[0134] Also, in the configuration illustrated in FIG. 14A, the capacitor C1 can also function as the capacitor C2 in the configuration shown in FIG. 6 and the like. That is, the capacitor C1 can also function as a holding capacitor that holds the potential of the node to which the gate of the transistor M13 is connected. As a result, compared with the configuration shown in FIG. 6 and the like, the capacitor C2 and the wiring VCP can be omitted, so that the pixel configuration can be further simplified.

[0135] Here, no wiring to which a fixed potential is applied is connected to the capacitor C1. Therefore, when charging or discharging either one of the pair of electrodes of the capacitor C1, it is preferable to apply a fixed potential to the other. Specifically, a fixed potential (for example, potential V off ) is applied from the wiring SL1 via the transistor M1, or a fixed potential (for example, potential V 0 or potential V RS ) is applied from the wiring VL1 via the transistor M12.

[0136] FIG. 14B shows an example in which transistors having a back gate are applied to the respective transistors in FIG. 14A. Here, transistors having a pair of gates connected are applied to all the transistors. Note that, as described above, the method of connecting the back gate is not limited to this. Also, as described above, transistors without a back gate and transistors with a back gate may be mixed.

[0137] 〔Example configuration of pixel 3-2〕 FIG. 15 shows an example in which the wiring WX is omitted from the configuration shown in FIG. 14A. One of the source and the drain of the transistor M14 is electrically connected to the wiring SL1. The wiring SL1 can also function as the wiring WX. As a result, the pixel configuration can be further simplified.

[0138] [Configuration Example 3 of Display Device] The pixel circuits illustrated in FIGS. 14A, 14B, and 15 can be applied to the sub-pixel 20R of the display device illustrated in FIGS. 5, 10A, etc.

[0139] FIG. 16 shows an example of applying the pixel circuit illustrated in FIG. 14A to the display device of FIG. 10. Here, an example of a circuit diagram is shown 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, similar to FIG. 11.

[0140] [Example Driving Method 2] Hereinafter, another example of the driving method of the display device will be described. Here, the configuration illustrated in FIG. 16 will be taken as an example for explanation.

[0141] Note that, for the parts overlapping with the above Example Driving Method 1, these may be incorporated and the description may be omitted.

[0142] For the operation during the display period, a method similar to the method illustrated in the above Example Driving Method 1 and FIG. 12 can be applied.

[0143] Hereinafter, the operation during the imaging period will be described with reference to FIG. 17. Here, the case of performing the imaging operation in the global shutter method will also be described.

[0144] FIG. 17 shows the potential transitions for the wirings REN, SE[i], RS[i], SE[i + 1], RS[i + 1], VL1, SL1[1:N], GL[1:M], and WX.

[0145] During the initialization period, the wiring REN and all the wirings RS are set to the high-level potential. As a result, the potential V is applied from the wiring VL1 to the node to which the gate of the transistor M13 is connected and the anode of the light-emitting and receiving element SR via the transistors M12 and M10. RS is applied.

[0146] Also, set all the wirings GL[1:M] to a high level potential and apply the potential V off to all the wirings SL1[1:N]. Thereby, the potential V is applied from the wiring SL1 to the gate of the transistor M2 via the transistor M1, off and the transistor M2 can be set to a non-conducting state.

[0147] Subsequently, during the exposure period, set the wirings REN, RS, GL, etc. to a low level potential. Thereby, charges corresponding to the light irradiated to the light-emitting and receiving element SR are accumulated.

[0148] Subsequently, during the transfer period, set the wiring REN to a high level potential. Thereby, the charges accumulated in the light-emitting and receiving element SR can be transferred to the node to which the gate of the transistor M13 is connected.

[0149] At this time, if the node to which the gate of the transistor M2 is connected is in a floating state, when the transistor M10 is set to a conducting state after exposure, the potential of the node to which the gate of the transistor M2 is connected may increase due to capacitive coupling by the capacitor C1. Therefore, as shown in FIG. 17, during the transfer period, it is preferable to apply a high level potential to the wirings GL[1:M] and apply the potential V off to the wirings SL1[1:N] to surely turn off the transistor M2.

[0150] Subsequently, imaging data is read out row by row. The operation during the readout period is the same as above, and data can be read out for all the pixels by applying a high level potential to the wiring SE one row at a time in order. Also, during the readout period of one row, by applying a high level potential to the wiring RS, two types of data can be output to the wiring WX, and CDS may be performed in the circuit unit 15.

[0151] Here, during the exposure period and the readout period, a low-level potential is applied to all wirings GL, and the transistor M1 is in a non-conductive state. As a result, the gate of the transistor M2 is held in a state where the potential V off that makes the transistor M2 non-conductive is applied, so that current flowing through the transistor M2 can be suppressed. Therefore, imaging with reduced noise can be performed. At this time, since the transistor M1 is in a non-conductive state, the potential applied to the wiring SL1 does not matter (denoted as don‘t care).

[0152] The above is the description of Driving Method Example 2.

[0153] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be appropriately combined with at least a part of other configuration examples, drawings, etc.

[0154] This embodiment can be implemented by appropriately combining at least a part of it with other embodiments described in this specification.

[0155] (Embodiment 2) In this embodiment, a display device according to an aspect of the present invention will be described.

[0156] A display device according to an aspect of the present invention includes a light-emitting element and a light-emitting and light-receiving element.

[0157] The light-emitting and light-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, by adding an active layer of an organic photodiode to the stacked structure of the organic EL element, a light-emitting and light-receiving element can be manufactured. Further, for a light-emitting and light-receiving element manufactured by combining an organic EL element and an organic photodiode, the number of film-forming steps can be suppressed by forming in one batch the layers that can have the same configuration as the organic EL element.

[0158] For example, one of a pair of electrodes (common electrode) can be a layer common to the light-receiving and emitting element and the light-emitting element. Further, 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 is a layer common to the light-receiving and emitting element and the light-emitting element. Further, for example, except for the presence or absence of the active layer of the light-receiving element, the light-receiving and emitting element and the light-emitting element can have the same configuration. That is, a light-receiving and emitting element can be manufactured by simply adding the active layer of the light-receiving element to the light-emitting element. Thus, by having a common layer in the light-receiving and emitting element and the light-emitting element, the number of film formation times and the number of masks can be reduced, and the manufacturing process and manufacturing cost of the display device can be reduced. Further, a display device having a light-receiving and emitting element can be manufactured using an existing manufacturing apparatus and manufacturing method of the display device.

[0159] Note that the layers of the light-receiving and emitting element may have different functions when the light-receiving and emitting 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-receiving and emitting element functions as a light-emitting element. For example, the hole injection layer functions as a hole injection layer when the light-receiving and emitting element functions as a light-emitting element, and functions as a hole transport layer when the light-receiving and emitting element functions as a light-receiving element. Similarly, the electron injection layer functions as an electron injection layer when the light-receiving and emitting element functions as a light-emitting element, and functions as an electron transport layer when the light-receiving and emitting element functions as a light-receiving element.

[0160] Thus, the display device of this embodiment has a light-receiving and emitting element and a light-emitting element in the display unit. Specifically, in the display unit, the light-receiving and emitting element and the light-emitting element 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.

[0161] The display unit can be used for an image sensor, a touch sensor, etc. That is, by detecting light with the display unit, it is possible to capture an image, detect the approach or contact of an object (finger, pen, etc.), and so on. Furthermore, in the display device of the present embodiment, the light-emitting element can be used as the 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.

[0162] In the display device of the present embodiment, when the light emitted by the light-emitting element of the display unit is reflected by an object, the light-receiving and light-emitting element can detect the reflected light. Therefore, imaging, touch (contact or approach) detection, etc. are possible even in a dark place.

[0163] The display device of the present embodiment has a function of displaying an image using the light-emitting element and the light-receiving and light-emitting element. That is, the light-emitting element and the light-receiving and light-emitting element function as display elements.

[0164] 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 of 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). In addition, an LED such as a micro LED (Light Emitting Diode) can also be used as the light-emitting element.

[0165] The display device of the present embodiment has a function of detecting light using the light-receiving and light-emitting element. The light-receiving and light-emitting element can detect light having a shorter wavelength than the light emitted by the light-receiving and light-emitting element itself.

[0166] When the light-emitting and light-receiving element is used in an image sensor, the display device of the present embodiment can capture an image using the light-emitting and light-receiving element. For example, the display device of the present embodiment can be used as a scanner.

[0167] For example, using an image sensor, data such as fingerprints and palm prints can be acquired. That is, a biometric sensor can be incorporated into the display device of the present embodiment. By incorporating the biometric sensor into the display device, the number of components of the electronic device can be reduced compared to the case where a biometric sensor is provided separately from the display device, and the electronic device can be miniaturized and lightened.

[0168] Also, using an image sensor, data such as the user's facial expression, eye movement, or change in pupil diameter can be acquired. By analyzing the data, information about the user's physical and mental state can be obtained. By changing the output content of one or both of the display and sound based on the information, 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 use the device safely.

[0169] Also, when the light-emitting and light-receiving element is used in a touch sensor, the display device of the present embodiment can detect the approach or contact of an object using the light-emitting and light-receiving element.

[0170] 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. Based on the amount of incident light, the amount of generated electric charges is determined.

[0171] The light-emitting and light-receiving element can be manufactured by adding the active layer of a light-receiving element to the configuration of the above-described light-emitting element.

[0172] For the light-emitting and light-receiving element, for example, the active layer of a pn-type or pin-type photodiode can be used.

[0173] In particular, for the light-emitting and light-receiving element, it is preferable to use the active layer of an organic photodiode having a layer containing an organic compound. Since an organic photodiode can be easily thinned, lightened, and enlarged in area, and also has a high degree of freedom in shape and design, it can be applied to various display devices.

[0174] Figures 18A to 18D show cross-sectional views of a display device according to an aspect of the present invention.

[0175] The display device 350A shown in Figure 18A 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.

[0176] The display device 350B shown in Figure 18B has a layer 353 having a light-emitting and light-receiving element, a layer 355 having a transistor, and a layer 357 having a light-emitting element between a substrate 351 and a substrate 359.

[0177] The display devices 350A and 350B are configured such that green (G) light and blue (B) light are emitted from the layer 357 having a light-emitting element, and red (R) light is emitted from the layer 353 having a light-emitting and light-receiving element. Note that in the display device according to an aspect of the present invention, the color of the light emitted from the layer 353 having a light-emitting and light-receiving element is not limited to red.

[0178] The light-emitting and light-receiving element included in the layer 353 having a light-emitting and light-receiving element can detect light incident from outside the display device 350A or the display device 350B. The light-emitting and light-receiving element can detect, for example, one or both of green (G) light and blue (B) light.

[0179] 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 receiving element or one light-emitting element. For example, the pixel may have a configuration with three sub-pixels (such as three colors of R, G, B, or three colors of yellow (Y), cyan (C), and magenta (M)), or a configuration with four sub-pixels (such as four colors of R, G, B, white (W), or four colors of R, G, B, Y). At least one color of sub-pixel has a light-emitting and receiving element. The light-emitting and receiving elements may be provided in all pixels or in some pixels. Also, one pixel may have a plurality of light-emitting and receiving elements.

[0180] The layer 355 having transistors has, for example, a transistor electrically connected to the light-emitting and receiving element and a transistor electrically connected to the light-emitting element. The layer 355 having transistors may further have wiring, electrodes, terminals, capacitors, resistors, etc.

[0181] The display device according to one aspect of the present invention may have a function of detecting an object such as a finger in contact with the display device (FIG. 18C). Or it may have a function of detecting an object approaching (not in contact with) the display device (FIG. 18D). For example, as shown in FIGS. 18C and 18D, the light emitted by the light-emitting element in the layer 357 having the light-emitting element is reflected by the finger 352 in contact with or approaching the display device 350B, and the light-emitting and receiving element in the layer 353 having the light-emitting and receiving 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.

[0182] [Pixel] Examples of pixels are shown in FIGS. 18E to 18G and FIGS. 19A to 19D. Note that the arrangement order of the sub-pixels is not limited to the illustrated order. For example, the positions of the sub-pixel 311B and the sub-pixel 311G may be reversed.

[0183] The pixel shown in FIG. 18E has sub-pixels 311SR that exhibit red light and have a light-receiving function, sub-pixel 311G that exhibits green light, and sub-pixel 311B that exhibits blue light, to which a stripe array is applied. 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 for the pixel can be manufactured by replacing the light-emitting element used for the R sub-pixel with a light-emitting and light-receiving element.

[0184] The pixel shown in FIG. 18F has sub-pixels 311SR that exhibit red light and have a light-receiving function, sub-pixel 311G that exhibits green light, sub-pixel 311B that exhibits blue light, and sub-pixel 311W that exhibits white light, to which a matrix array is applied. 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 for the pixel can be manufactured by replacing the light-emitting element used for the R sub-pixel with a light-emitting and light-receiving element.

[0185] The pixel shown in FIG. 18G has sub-pixels that exhibit two different colors of light combined by the pixel, to which a pentile array is applied. The upper left pixel and the lower right pixel shown in FIG. 18G have sub-pixel 311SR that exhibits red light and has a light-receiving function, and sub-pixel 311G that exhibits green light. The lower left pixel and the upper right pixel shown in FIG. 18G have sub-pixel 311G that exhibits green light and sub-pixel 311B that exhibits blue light. Note that the shape of the sub-pixels shown in FIG. 18G indicates the upper surface shape of the light-emitting element or the light-emitting and light-receiving element included in the sub-pixel.

[0186] The pixel shown in FIG. 19A has sub-pixels 311SR that exhibit red light and have a light-receiving function, sub-pixel 311G that exhibits green light, and sub-pixel 311B that exhibits blue light. Sub-pixel 311SR is arranged in a column different from sub-pixel 311G and sub-pixel 311B. Sub-pixel 311G and sub-pixel 311B 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 sub-pixels of other colors is not limited to red (R), and may be green (G) or blue (B).

[0187] FIG. 19B shows two pixels, and one pixel is composed of three sub-pixels surrounded by a dotted line. The pixels shown in FIG. 19B have a sub-pixel 311SR that exhibits red light and has a light-receiving function, a sub-pixel 311G that exhibits green light, and a sub-pixel 311B that exhibits blue light. In the left pixel shown in FIG. 19B, the sub-pixel 311G is arranged in the same row as the sub-pixel 311SR, and the sub-pixel 311B is arranged in the same column as the sub-pixel 311SR. In the right pixel shown in FIG. 19B, the sub-pixel 311G is arranged in the same row as the sub-pixel 311SR, and the sub-pixel 311B is arranged in the same column as the sub-pixel 311G. In the pixel layout shown in FIG. 19B, in both odd rows and even rows, the sub-pixels 311SR, 311G, and 311B are repeatedly arranged, and in each column, sub-pixels of different colors are arranged in odd rows and even rows.

[0188] FIG. 19C is a modification of the pixel array shown in FIG. 18G. The upper left pixel and the lower right pixel shown in FIG. 19C have a sub-pixel 311SR that exhibits red light and has a light-receiving function, and a sub-pixel 311G that exhibits green light. The lower left pixel and the upper right pixel shown in FIG. 19C have a sub-pixel 311SR that exhibits red light and has a light-receiving function, and a sub-pixel 311B that exhibits blue light.

[0189] In FIG. 18G, a sub-pixel 311G that exhibits green light is provided for each pixel. On the other hand, in FIG. 19C, a sub-pixel 311SR 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. 19C, imaging can be performed with higher resolution than the configuration shown in FIG. 18G. Thereby, for example, the accuracy of biometric authentication can be improved.

[0190] Further, the upper surface shapes of the light-emitting element and the light-receiving and light-emitting element are not particularly limited, and can be circular, elliptical, polygonal, rounded polygonal, etc. Regarding the upper surface shape of the light-emitting element included in the sub-pixel 311G, an example of a circular shape is shown in FIG. 18G, and an example of a square shape is shown in FIG. 19C. The upper surface shapes of the light-emitting elements and the light-receiving and light-emitting elements of each color may be different from each other, or may be the same for some or all colors.

[0191] 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 colors. For example, the aperture ratio of the sub-pixel provided in each pixel (sub-pixel 311G in FIG. 18G, sub-pixel 311SR in FIG. 19C) may be made smaller than the aperture ratios of the sub-pixels of other colors.

[0192] FIG. 19D is a modified example of the pixel arrangement shown in FIG. 19C. Specifically, the configuration of FIG. 19D is obtained by rotating the configuration of FIG. 19C by 45°. In FIG. 19C, it was described that one pixel is composed of two sub-pixels, but as shown in FIG. 19D, it can also be considered that one pixel is composed of four sub-pixels.

[0193] In FIG. 19D, the description will be made on the assumption that one pixel is composed of four sub-pixels surrounded by a dotted line. One pixel has two sub-pixels 311SR, one sub-pixel 311G, and one sub-pixel 311B. In this way, by having a plurality of sub-pixels having 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 made √2 times the display definition.

[0194] The display device to which the configuration shown in FIG. 19C or FIG. 19D 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.

[0195] 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 the light-emitting element that emits blue light as the light source. Therefore, it is preferable that the light-emitting and receiving element has a function of receiving blue light.

[0196] As described above, various arrays of pixels can be applied to the display device according to one aspect of the present invention.

[0197] In the display device of the present embodiment, since it is not necessary to change the pixel array in order 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 fineness.

[0198] [Light-emitting and receiving element] Examples of the stacked structure of the light-emitting and receiving element are shown in FIGS. 20A to 20E.

[0199] The light-emitting and receiving element has at least an active layer and a light-emitting layer between a pair of electrodes.

[0200] As layers other than the active layer and the light-emitting layer, the light-emitting and 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).

[0201] The light-emitting and light-receiving elements shown in FIGS. 20A to 20C 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.

[0202] Note that the light-emitting and light-receiving elements shown in FIGS. 20A to 20C can each be said to have a configuration in which an active layer 183 is added to the light-emitting element. Therefore, by simply adding a step of forming the active layer 183 to the manufacturing process of the light-emitting element, the light-emitting and light-receiving element can be formed in parallel with the formation of the light-emitting element. Further, 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.

[0203] The stacking order of the light-emitting layer 193 and the active layer 183 is not limited. FIG. 20A 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. Further, FIG. 20B 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. Further, as shown in FIGS. 20A and 20B, the active layer 183 and the light-emitting layer 193 may be in contact with each other.

[0204] As shown in FIG. 20C, 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 of 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. 20C shows an example in which the hole transport layer 182 is used as the buffer layer.

[0205] By providing a buffer layer between the active layer 183 and the light-emitting layer 193, it is possible to suppress the transfer of excitation energy from the light-emitting layer 193 to the active layer 183. Further, the optical path length (cavity length) of the microcavity structure can also be adjusted using the buffer layer. Therefore, a high luminous efficiency can be obtained from the light-emitting and light-receiving element having a buffer layer between the active layer 183 and the light-emitting layer 193.

[0206] The light-emitting and light-receiving element shown in FIG. 20D is different from the light-emitting and light-receiving elements shown in FIGS. 20A and 20C in that it does not have a hole transport layer 182. The light-emitting and light-receiving element may not have at least one of a hole injection layer 181, a hole transport layer 182, an electron transport layer 184, and an electron injection layer 185. Further, the light-emitting and light-receiving element may have other functional layers such as a hole blocking layer and an electron blocking layer.

[0207] The light-emitting and light-receiving element shown in FIG. 20E is different from the light-emitting and light-receiving elements shown in FIGS. 20A to 20C in that it does not have an active layer 183 and a light-emitting layer 193, and has a layer 186 that also serves as a light-emitting layer and an active layer.

[0208] As the layer 186 that also serves as 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.

[0209] 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.

[0210] In the light-emitting and light-receiving element, a conductive film that transmits visible light is used for the electrode on the side where light is extracted. Further, it is preferable to use a conductive film that reflects visible light for the electrode on the side where light is not extracted.

[0211] 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 hole transport layer. The hole injection layer is a layer containing a material with high hole injection properties. As the material with high hole injection properties, a composite material containing a hole transport material and an acceptor material (electron accepting material), or an aromatic amine compound (a compound having an aromatic amine skeleton) can be used.

[0212] 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 to the light-emitting layer by the hole injection 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 the 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, hole-transporting materials with high hole transportability such as π-electron-excessive heteroaromatic compounds (for example, carbazole derivatives, thiophene derivatives, furan derivatives, etc.), aromatic amine compounds, etc. are preferable.

[0213] 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 to the light-emitting layer by the electron injection 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 the 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 an electron mobility of 1×10 -6 cm 2 / Vs or more is preferable. In addition, as long as the substance has higher electron transportability than holes, other substances can also be used. As the electron-transporting material, 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. In addition, 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-transporting materials including nitrogen-containing heteroaromatic compounds such as π-electron-deficient heteroaromatic compounds can be used.

[0214] When driving a light-emitting device using a light-emitting element as the light-emitting device, the electron injection layer is a layer that injects electrons from the cathode into the electron transport layer. The electron injection layer is a layer containing a material with high electron injection properties. As a material with high electron injection properties, an alkali metal, an alkaline earth metal, or a compound thereof can be used. As a 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.

[0215] The light-emitting layer 193 is a layer containing a light-emitting substance. The light-emitting layer 193 can have one or more 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 can be appropriately used. Also, as the light-emitting substance, a substance that emits near-infrared light can be used.

[0216] Examples of the light-emitting substance include a fluorescent material, a phosphorescent material, a TADF material, a quantum dot material, and the like.

[0217] 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.

[0218] Examples of the phosphorescent material include organometallic complexes (especially iridium complexes) having a 4H-triazole skeleton, a 1H-triazole skeleton, an imidazole skeleton, a pyrimidine skeleton, a pyrazine skeleton, or a pyridine skeleton, organometallic complexes (especially iridium complexes) having a phenylpyridine derivative having an electron-withdrawing group as a ligand, platinum complexes, rare earth metal complexes, and the like.

[0219] In addition to the luminescent material (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.

[0220] The light-emitting layer 193 preferably has, for example, a phosphorescent material and a hole-transporting material and an electron-transporting material which are a combination likely to form an exciplex. By adopting such a configuration, efficient light emission using ExTET (Exciplex-Triplet Energy Transfer), which is energy transfer from the exciplex to the luminescent material (phosphorescent material), can be obtained. By selecting a combination that forms an exciplex that emits light overlapping the wavelength of the absorption band on the lowest energy side of the luminescent material, the energy transfer becomes smooth and efficient light emission can be obtained. With this configuration, high efficiency, low voltage driving, and long life of the light-emitting element can be achieved simultaneously.

[0221] As a combination of materials that form an exciplex, it is preferable that the HOMO level (highest occupied orbital level) of the hole-transporting material is equal to or higher than the HOMO level of the electron-transporting material. It is preferable that the LUMO level (lowest unoccupied orbital level) of the hole-transporting material is equal to or 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 characteristics (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV) measurement.

[0222] The formation of an exciplex can be confirmed, for example, by comparing the emission spectra of a hole-transporting material, an electron-transporting material, and a mixed film obtained by mixing these materials, 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, the transient photoluminescence (PL) of a hole-transporting material, the transient PL of an electron-transporting material, and the transient PL of a mixed film obtained by mixing these materials are compared, and the formation of an exciplex can be confirmed by observing differences in transient responses such as that the transient PL lifetime of the mixed film has a longer-lived component or the ratio of the delayed component is increased compared to the transient PL lifetimes of the respective materials. Further, the above-described transient PL may be read as transient electroluminescence (EL). That is, the formation of an exciplex can also be confirmed by comparing the transient EL of a hole-transporting material, the transient EL of a material having electron-transporting properties, and the transient EL of a mixed film thereof, and observing differences in transient responses.

[0223] The active layer 183 contains a semiconductor. Examples of the 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. By using an organic semiconductor, the light-emitting layer 193 and the active layer 183 can be formed by the same method (for example, vacuum deposition method), and it is preferable because the manufacturing apparatus can be shared.

[0224] Examples of the material of the n-type semiconductor included in the active layer 183 include fullerenes (for example, C 60 、C 70Examples of electron-accepting organic semiconductor materials include fullerenes and fullerene derivatives. Fullerenes have a soccer ball-like shape, which is energetically stable. Fullerenes have deep (low) HOMO and LUMO levels. Due to the deep LUMO level, fullerenes have extremely high electron-accepting (acceptor) properties. Usually, when π-electron conjugation (resonance) spreads in a plane like benzene, the electron-donating (donor) property increases. However, fullerenes have a spherical shape, and despite the large spread of π-electrons, they have high electron-accepting properties. High electron-accepting properties are beneficial for a light-receiving element because they cause 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.

[0225] Examples of materials for n-type semiconductors 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, and the like.

[0226] Examples of materials for the p-type semiconductor that the active layer 183 has include electron-donating organic semiconductor materials such as copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), and quinacridone.

[0227] Examples of the p-type semiconductor material include carbazole derivatives, thiophene derivatives, furan derivatives, aromatic amine compounds, etc. 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, etc.

[0228] 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.

[0229] 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 with 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.

[0230] For example, the active layer 183 is preferably formed by co-evaporating an n-type semiconductor and a p-type semiconductor.

[0231] 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.

[0232] For the positive hole injection layer 181, the positive hole transport layer 182, the active layer 183, the light emitting layer 193, the electron transport layer 184, the electron injection layer 185, and the layer 186 that also serves as the light emitting layer and the active layer, either a low molecular compound or a high molecular compound can be used, and they may contain an inorganic compound. Each layer can be formed by methods such as vapor deposition (including vacuum vapor deposition), transfer method, printing method, inkjet method, coating method, etc.

[0233] Hereinafter, with reference to FIGS. 21 to 23, the detailed configurations of the light emitting and receiving elements included in the display device according to one embodiment of the present invention will be described.

[0234] 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.

[0235] In FIGS. 21 to 23, a top emission type display device will be described as an example.

[0236] [Configuration Example 1] The display devices shown in FIGS. 21A and 21B 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 receiving element 347SR that emits red (R) light and has a light receiving function, via a layer 355 having a transistor on a substrate 151.

[0237] FIG. 21A shows a case where the light emitting and receiving element 347SR functions as a light emitting element. FIG. 21A 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 receiving element 347SR emits red light.

[0238] FIG. 21B shows a case where the light emitting and receiving element 347SR functions as a light receiving element. FIG. 21B shows an example in which the light emitting and receiving element 347SR detects the blue light emitted by the light emitting element 347B and the green light emitted by the light emitting element 347G.

[0239] The light-emitting element 347B, the light-emitting element 347G, and the light-receiving and emitting element 347SR 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.

[0240] In the present embodiment, similar to the light-emitting element, in the light-receiving and emitting element 347SR 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 emitting element 347SR can detect the light incident on the light-receiving and emitting element 347SR, 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.

[0241] The common electrode 115 is commonly used for the light-emitting element 347B, the light-emitting element 347G, and the light-receiving and emitting element 347SR.

[0242] 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 emitting element 347SR can be made equal. Thereby, the manufacturing cost of the display device can be reduced and the manufacturing process can be simplified.

[0243] The configuration of the display device shown in FIGS. 21A and 21B will be specifically described.

[0244] 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.

[0245] 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.

[0246] The light-emitting and light-receiving element 347SR 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 347SR has a function of emitting red light. The light-emitting and light-receiving element 347SR preferably has a function of detecting the light emission of at least one of the light-emitting element 347G and the light-emitting element 347B, and more preferably has a function of detecting the light emission of both of them.

[0247] It is preferable that the active layer 183 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 347SR can have a function of efficiently emitting red light and a function of accurately detecting light with a shorter wavelength than red light.

[0248] 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.

[0249] In the display device shown in FIGS. 21A and 21B, the buffer layer, the active layer, and the light-emitting layer are layers that are separately formed for each element.

[0250] 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.

[0251] [Configuration Example 2] As shown in FIGS. 22A and 22B, the light-emitting elements 347B, 347G, and the light-emitting and light-receiving element 347SR 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.

[0252] The light-emitting elements 347B, 347G, and the light-emitting and light-receiving element 347SR shown in FIG. 22A have a common layer 112 and a common layer 114 in addition to the configuration shown in FIGS. 21A and 21B.

[0253] The light-emitting elements 347B, 347G, and the light-emitting and light-receiving element 347SR shown in FIG. 22B are different from the configuration shown in FIGS. 21A and 21B in that they do not have the buffer layers 192R, 192G, 192B and the buffer layers 194R, 194G, 194B, but have a common layer 112 and a common layer 114.

[0254] 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.

[0255] The common layer 112 and the common layer 114 may each have a single-layer structure or a stacked structure.

[0256] [Configuration Example 3] The display device shown in Fig. 23A is an example in which the stacked structure shown in Fig. 20C is applied to the light-emitting and light-receiving element 347SR.

[0257] The light-emitting and light-receiving element 347SR 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.

[0258] 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.

[0259] 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.

[0260] 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.

[0261] It is preferable that a microcavity structure is applied to the light-emitting element included in the display device of the present embodiment. Therefore, one of the pair of electrodes included in the light-emitting element is preferably an electrode having transparency and reflectivity with respect to visible light (semi-transmissive / semi-reflective electrode), and the other is preferably an electrode having reflectivity with respect to visible light (reflective electrode). By having a microcavity structure in the light-emitting element, the light emission obtained from the light-emitting layer can be resonated between both electrodes, and the light emitted from the light-emitting element can be enhanced.

[0262] Incidentally, the semi-transmissive / semi-reflective electrode can have a laminated structure of a reflective electrode and an electrode having transmissivity for 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 a function as a pixel electrode or a common electrode.

[0263] 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 with 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). Also, 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 each 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 1×10 -2 Ω·cm or less.

[0264] The hole transport layers 182B, 182G, and 182R may each have a 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 / receiving element 347SR, 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. Incidentally, 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.

[0265] [Configuration Example 4] The display device shown in FIG. 23B is an example in which the laminated structure shown in FIG. 20D is applied to the light-emitting / receiving element 347SR.

[0266] The light-emitting element 347SR 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.

[0267] 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.

[0268] 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.

[0269] 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.

[0270] 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 347SR. 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.

[0271] Hereinafter, with reference to FIGS. 24 to 29, the detailed configuration of a display device according to an aspect of the present invention will be described.

[0272] [Display device 310A] Cross-sectional views of the display device 310A are shown in FIGS. 24A and 24B.

[0273] The display device 310A includes a light-emitting element 190B, a light-emitting element 190G, and a light-emitting and receiving element 190SR.

[0274] 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.

[0275] 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.

[0276] The light-emitting and light-receiving element 190SR 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 190SR has a function of emitting red light 321R and a function of detecting light 322.

[0277] FIG. 24A shows a case where the light-emitting and light-receiving element 190SR functions as a light-emitting element. FIG. 24A 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 190SR emits red light.

[0278] FIG. 24B shows a case where the light-emitting and light-receiving element 190SR functions as a light-receiving element. FIG. 24B shows an example in which the light-emitting and light-receiving element 190SR detects the blue light emitted by the light-emitting element 190B and the green light emitted by the light-emitting element 190G.

[0279] 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.

[0280] As the partition wall 216, an organic insulating film is preferable. 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. Instead of the partition wall 216, a partition wall that blocks visible light may be provided.

[0281] The display device 310A includes a light-emitting and light-receiving element 190SR, a light-emitting element 190G, a light-emitting element 190B, a transistor 342, etc. between a pair of substrates (substrate 151 and substrate 152).

[0282] The light-emitting and light-receiving element 190SR has a function of detecting light. Specifically, the light-emitting and light-receiving element 190SR is a photoelectric conversion element that receives the light 322 incident from the outside of the display device 310A and converts it into an electrical signal. The light 322 can also be the light reflected by an 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 light-receiving element 190SR through a lens.

[0283] 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).

[0284] The buffer layer 192 (buffer layer 192R, buffer layer 192G, buffer layer 192B), the light-emitting layer 193 (light-emitting layer 193R, light-emitting layer 193G, light-emitting layer 193B), and the buffer layer 194 (buffer layer 194R, buffer layer 194G, buffer layer 194B) can also be referred to as organic layers (layers containing organic compounds) or EL layers. The pixel electrode 191 preferably has a function of reflecting visible light. The common electrode 115 has a function of transmitting visible light.

[0285] 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 light-receiving element.

[0286] At least a part of the circuit electrically connected to the light-emitting element 190SR is preferably formed of the same material and in the same process as the circuit electrically connected to the light-emitting element 190G and the light-emitting element 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.

[0287] The light-emitting and receiving element 190SR, the light-emitting element 190G, and the light-emitting element 190B are each preferably covered with a protective layer 195. In FIG. 24A and the like, the protective layer 195 is provided in contact with the common electrode 115. By providing the protective layer 195, the entry of impurities into the light-emitting and receiving element 190SR and the light-emitting elements of each color can be suppressed, and the reliability of the light-emitting and receiving element 190SR and the light-emitting elements of each color can be enhanced. Further, the protective layer 195 and the substrate 152 are bonded together by an adhesive layer 142.

[0288] 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 element 190G and the light-emitting element 190B, and at positions overlapping the light-emitting and receiving element 190SR. In this specification and the like, the position overlapping the light-emitting element 190G or the light-emitting element 190B specifically refers to the position overlapping the light-emitting region of the light-emitting element 190G or the light-emitting element 190B. Similarly, the position overlapping the light-emitting and receiving element 190SR specifically refers to the position overlapping the light-emitting region and the light-receiving region of the light-emitting and receiving element 190SR.

[0289] As shown in FIG. 24B, the light-emitting element 190G or the light-emitting element 190B emits light, and the light-receiving and light-emitting element 190SR 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-receiving and light-emitting element 190SR 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-receiving and light-emitting element 190SR. By providing the light-shielding layer BM, the incidence of the reflected light 324 on the light-receiving and light-emitting element 190SR can be suppressed. Thereby, noise can be reduced and the sensitivity of the sensor using the light-receiving and light-emitting element 190SR can be increased.

[0290] 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.

[0291] [Display device 310B] The display device 310B shown in FIG. 25A is different from the display device 310A in that the light-emitting element 190G, the light-emitting element 190B, and the light-receiving and light-emitting element 190SR 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.

[0292] Note that the laminated structure of the light-emitting element 190B, the light-emitting element 190G, and the light-receiving and light-emitting element 190SR is not limited to the configurations shown in the display devices 310A and 310B. For each element, for example, the laminated structures shown in FIGS. 20 to 23 can be appropriately applied.

[0293] [Display device 310C] The display device 310C differs 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.

[0294] 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.

[0295] The display device 310C is configured by transferring the insulating layer 212, the transistor 342, the light-emitting and receiving element 190SR, 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.

[0296] 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 with a thickness sufficient to have flexibility may be used for one or both of the substrates 153 and 154.

[0297] 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.

[0298] Hereinafter, with reference to FIGS. 26 to 29, a more detailed configuration of the display device according to one aspect of the present invention will be described.

[0299] [Display Device 100A] FIG. 26 shows a perspective view of the display device 100A, and FIG. 27 shows a cross-sectional view of the display device 100A.

[0300] The display device 100A has a configuration in which a substrate 152 and a substrate 151 are bonded together. In FIG. 26, the substrate 152 is indicated by a broken line.

[0301] The display device 100A includes a display unit 162, a circuit 164, a wiring 165, etc. FIG. 26 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. 26 can also be referred to as a display module having the display device 100A, the IC, and the FPC.

[0302] As the circuit 164, for example, a scanning line driving circuit can be used.

[0303] 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.

[0304] FIG. 26 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.

[0305] FIG. 27 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. 26 are each cut.

[0306] The display device 100A shown in FIG. 27 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 190SR, etc. between a substrate 151 and a substrate 152.

[0307] 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 190SR, a solid sealing structure, a hollow sealing structure, or the like can be applied. In FIG. 27, 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 190SR. 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.

[0308] 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. The end portion of the pixel electrode 191 is covered by a partition wall 216. The pixel electrode 191 contains a material that reflects visible light, and the common electrode 115 contains a material that transmits visible light.

[0309] 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.

[0310] The light-emitting and receiving element 190SR 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 190SR.

[0311] The light emitted from the light-emitting element 190B, the light-emitting element 190G, and the light-emitting and receiving element 190SR is emitted toward the substrate 152 side. Further, light is incident on the light-emitting and receiving element 190SR through the substrate 152 and the space 143. It is preferable to use a material having high transparency to visible light for the substrate 152.

[0312] The pixel electrodes 191 can be fabricated using the same materials and the same process. The common layer 112, the common layer 114, and the common electrode 115 are used in common for the light-emitting element 190B, the light-emitting element 190G, and the light-receiving and light-emitting element 190SR. The light-receiving and light-emitting element 190SR 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-receiving and light-emitting element 190SR 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.

[0313] 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-receiving and light-emitting element 190SR. By providing the light-shielding layer BM, the range in which the light-receiving and light-emitting element 190SR detects light can be controlled. Further, by having the light-shielding layer BM, it is possible to suppress light from directly entering the light-receiving and light-emitting element 190SR 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.

[0314] The transistors 201, 205, 206, and 207 are all formed on the substrate 151. These transistors can be fabricated using the same materials and the same process.

[0315] 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 so as to cover the transistors. The insulating layer 214 is provided so as 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.

[0316] It is preferable to use a material in which impurities such as water and 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, it is possible to effectively suppress the diffusion of impurities from the outside into the transistor, and the reliability of the display device can be improved.

[0317] 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, a 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, etc. may be used. Further, two or more of the above-mentioned insulating films may be laminated and used. Note that an underlayer film may be provided between the substrate 151 and the transistor. The above-mentioned inorganic insulating film can also be used for the underlayer film.

[0318] Here, the organic insulating film often has a lower barrier property than the inorganic insulating film. Therefore, the organic insulating film preferably has an opening near the end of the display device 100A. Thereby, it is possible to suppress the entry of impurities from the end of the display device 100A through the organic insulating film. 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.

[0319] The insulating layer 214 that functions as a planarization layer is preferably an organic insulating film. Examples of the material 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.

[0320] In the region 228 shown in FIG. 27, 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 enhanced.

[0321] 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 applied 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.

[0322] The structure of the transistors 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.

[0323] The transistors 201, 205, 206, and 207 are configured such that the semiconductor layer in which the channel is formed is sandwiched between two gates. The transistors may be driven by connecting the two gates and supplying the same signal thereto. Alternatively, the threshold voltage of the transistors 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.

[0324] 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 other than a single crystal (microcrystalline semiconductor, polycrystalline semiconductor, or semiconductor having a partial crystal region) 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.

[0325] 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 have silicon. Examples of silicon include amorphous silicon, crystalline silicon (such as low-temperature polysilicon and single crystal silicon).

[0326] 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.

[0327] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (IGZO). 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.

[0328] 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 compositions such as In:M:Zn = 1:1:1 or in the vicinity thereof, In:M:Zn = 1:1:1.2 or in the vicinity thereof, In:M:Zn = 2:1:3 or in the vicinity thereof, In:M:Zn = 3:1:2 or in the vicinity thereof, In:M:Zn = 4:2:3 or in the vicinity thereof, In:M:Zn = 4:2:4.1 or in the vicinity thereof, In:M:Zn = 5:1:3 or in the vicinity thereof, In:M:Zn = 5:1:6 or in the vicinity thereof, In:M:Zn = 5:1:7 or in the vicinity thereof, In:M:Zn = 5:1:8 or in the vicinity thereof, In:M:Zn = 10:1:3 or in the vicinity thereof, In:M:Zn = 6:1:6 or in the vicinity thereof, In:M:Zn = 5:2:5 or in the vicinity thereof, and the like. The composition in the vicinity includes a range of ±30% of the desired atomic ratio.

[0329] 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.

[0330] The transistors included in circuit 164 and the transistors 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.

[0331] In the region 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.

[0332] 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 dirt less likely to adhere, a hard coat film for suppressing the occurrence of scratches during use, a shock absorption layer, etc. may be arranged.

[0333] 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.

[0334] 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, phenol 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.

[0335] As the connection layer, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), etc. can be used.

[0336] 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.

[0337] 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 such metal materials can be used. Alternatively, nitrides of such 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, and conductive layers (conductive layers functioning as pixel electrodes or common electrodes) of light-emitting elements and light-emitting and receiving elements.

[0338] 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.

[0339] [Display device 100B] FIG. 28A shows a cross-sectional view of the display device 100B.

[0340] The display device 100B mainly differs from the display device 100A in that it has a protective layer 195. Detailed descriptions of the configurations similar to those of the display device 100A are omitted.

[0341] 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 190SR, 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 190SR, and improve the reliability of the light-emitting element 190B, the light-emitting element 190G, and the light-emitting and receiving element 190SR.

[0342] 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.

[0343] 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.

[0344] Furthermore, a lens may be provided in the region overlapping the light-emitting and receiving element 190SR. Thereby, the sensitivity and accuracy of the sensor using the light-emitting and receiving element 190SR can be improved.

[0345] 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.

[0346] 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 or zirconium oxide, etc. can be used for the nanoparticles.

[0347] 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.

[0348] In addition, in 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 190SR respectively, and a solid encapsulation structure is applied to the display device 100B.

[0349] [Display device 100C] FIG. 29A shows a cross-sectional view of the display device 100C.

[0350] The structure of the transistors in the display device 100C is different from that of the display device 100B.

[0351] The display device 100C has transistors 208, 209, and 210 on the substrate 151.

[0352] Transistors 208, 209, and 210 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.

[0353] 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. Of the conductive layers 222a and 222b, one functions as a source and the other functions as a drain.

[0354] 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.

[0355] The pixel electrode 191 of the light-receiving and light-emitting element 190SR is electrically connected to the other of the pair of low-resistance regions 231n of the transistor 209 through the conductive layer 222b.

[0356] In FIG. 29A, 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. 29B, 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. 29B can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In FIG. 29B, 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.

[0357] Further, 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.

[0358] 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.

[0359] The display device 100C is configured by transferring the insulating layer 212, the transistors 208, 209, 210, the light-emitting and receiving element 190SR, the light-emitting element 190G, 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 100C can be enhanced.

[0360] As the insulating layer 212, an inorganic insulating film that can be used for the insulating layers 211, 213, and 215 can be used.

[0361] As described above, in the display device of the present embodiment, a light-emitting and receiving element is provided in a sub-pixel that exhibits any color, instead of the light-emitting element. 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. Further, a light-receiving function can be imparted to a pixel without reducing the fineness of the display device, the aperture ratio of each sub-pixel, etc.

[0362] This embodiment can be implemented in appropriate combination with at least a part of other embodiments described in this specification.

[0363] (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.

[0364] 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 aluminum, gallium, yttrium, tin, etc. are contained. Further, one or more selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, etc. may be contained.

[0365] The metal oxide can be formed by a sputtering method, a chemical vapor deposition (CVD) method such as a metal organic chemical vapor deposition (MOCVD) method, an atomic layer deposition (ALD) method, or the like.

[0366] <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.

[0367] 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.

[0368] 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.

[0369] In addition, 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. In addition, in the diffraction pattern of an IGZO film formed at room temperature, a spot-like pattern is observed instead of a halo. Therefore, 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.

[0370] [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. In addition, 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.

[0371] Here, the details of the above-mentioned CAAC-OS, nc-OS, and a-like OS will be described.

[0372] [CAAC-OS] CAAC-OS is an oxide semiconductor having a plurality of crystal regions, and the c-axes of the plurality of crystal regions are oriented in a specific direction. 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. A crystal region is a region having periodicity in the atomic arrangement. When the atomic arrangement is regarded as a lattice arrangement, the 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. The strain refers to a portion where the direction of the lattice arrangement changes between a region where the lattice arrangements are aligned and another region where the lattice arrangements are aligned in the region where the plurality of crystal regions are connected. That is, CAAC-OS is an oxide semiconductor with c-axis orientation and no obvious orientation in the a-b plane direction.

[0373] 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. 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.

[0374] Also, in an In-M-Zn oxide (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 element M, zinc (Zn), and oxygen (hereinafter, (M,Zn) layer) are laminated. Indium and element M are mutually substitutable. Therefore, the (M,Zn) layer may contain indium. The In layer may contain element M. 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.

[0375] When performing a structural analysis on a CAAC-OS film using, for example, an XRD apparatus, in the out-of-plane XRD measurement using a 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.

[0376] 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.

[0377] 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 distinct grain boundary cannot be confirmed. That is, it can be seen that the formation of grain boundaries is suppressed by the distortion of the lattice arrangement. This is presumably because CAAC-OS can tolerate distortion due to the fact that the arrangement of oxygen atoms is not dense in the a-b plane direction and the interatomic bond distance changes due to the substitution of metal atoms.

[0378] Note that a crystal structure in which distinct grain boundaries are 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 carriers being trapped. Therefore, CAAC-OS in which distinct grain boundaries are not confirmed is one of the crystalline oxides having a crystal structure suitable for the semiconductor layer of a transistor. Note that to form 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.

[0379] CAAC-OS is an oxide semiconductor with high crystallinity and no distinct grain boundaries being confirmed. Thus, 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, defect generation, etc., CAAC-OS can also be said to be an oxide semiconductor with few impurities and 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 CAAC-OS is used for an OS transistor, it becomes possible to expand the degree of freedom in the manufacturing process.

[0380] [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 crystal is, for example, 1 nm or more and 10 nm or less, particularly 1 nm or more and 3 nm or less, the minute crystal is also referred to as a nano crystal. Also, nc-OS has no regularity in the crystal orientation between different nano crystals. Therefore, no orientation is seen in the entire film. Thus, depending on the analysis method, nc-OS may not be distinguishable from a-like OS or an amorphous oxide semiconductor. For example, when structural analysis is performed 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 electron beam diffraction (also referred to as limited field electron beam diffraction) using an electron beam with a probe diameter larger than the nano crystal (for example, 50 nm or more) is performed on an nc-OS film, a diffraction pattern like a halo pattern is observed. On the other hand, when 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 nano crystal (for example, 1 nm or more and 30 nm or less) is performed 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.

[0381] [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 with the nc-OS and the CAAC-OS. Also, the a-like OS has a higher hydrogen concentration in the film compared with the nc-OS and the CAAC-OS.

[0382] [[Configuration of Oxide Semiconductor]] Next, the details of the above-described CAC-OS will be described. Note that the CAC-OS relates to the material composition.

[0383] [CAC-OS] The CAC-OS is, for example, a configuration of a material in which elements constituting a 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. In the following, in a metal oxide, a state in which one or more metal elements are unevenly distributed and regions having the metal element are 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 is also referred to as a mosaic state or a patch state.

[0384] Furthermore, the CAC-OS is a configuration in which the material is separated into a first region and a second region to form a mosaic state, and the first region is a configuration (hereinafter also referred to as a cloud state) distributed in the film. That is, the CAC-OS is a composite metal oxide having a configuration in which the first region and the second region are mixed.

[0385] 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.

[0386] 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.

[0387] In addition, there are cases where a clear boundary between the first region and the second region cannot be observed.

[0388] 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.

[0389] CAC-OS can be formed by sputtering, for example, under conditions where the substrate is not intentionally heated. Also, when forming CAC-OS by sputtering, 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.

[0390] 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 the region mainly composed of In (the first region) and the region mainly composed of Ga (the second region) are unevenly distributed and have a mixed structure.

[0391] 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 in 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.

[0392] On the other hand, the second region is a region with higher insulation compared to the first region. That is, by the distribution of the second region in the metal oxide, the leakage current can be suppressed.

[0393] 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 semiconductor function as a whole. 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.

[0394] In addition, a transistor using CAC-OS has high reliability. Therefore, CAC-OS is optimal for various semiconductor devices including display devices.

[0395] 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.

[0396] <Transistor having an oxide semiconductor> Subsequently, the case of using the above oxide semiconductor in a transistor will be described.

[0397] By using the above oxide semiconductor in a transistor, a transistor with high field-effect mobility can be realized. Also, a highly reliable transistor can be realized.

[0398] It is preferable to use an oxide semiconductor with a low carrier concentration in a transistor. 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, still more preferably 1×10 10 cm -3 or less, and 1×10 -9 cm -3 or more. When 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. Note that an oxide semiconductor with a low carrier concentration may be referred to as a high-purity intrinsic or substantially high-purity intrinsic oxide semiconductor.

[0399] In addition, an oxide semiconductor film that is high-purity intrinsic or substantially high-purity intrinsic may have a low trap level density because the density of defect levels is low.

[0400] In addition, the charge trapped in the trap levels 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 with a high trap level density may have unstable electrical characteristics.

[0401] 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, and silicon.

[0402] <Impurity> Here, the influence of each impurity in the oxide semiconductor will be described.

[0403] In an oxide semiconductor, when silicon, carbon, or the like, 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 2×10 18 atoms / cm 3 or less, preferably 2×10 17 atoms / cm 3 or less.

[0404] Further, 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 1×10 18 atoms / cm 3 or less, preferably 2×10 16 atoms / cm 3 or less.

[0405] Further, 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 less than 5×10 19 atoms / cm 3 , preferably less than 5×10 18 atoms / cm 3 , more preferably less than 1×10 18 atoms / cm 3 , still more preferably less than 5×10 17 atoms / cm 3 or less.

[0406] 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 the 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.

[0407] By using an oxide semiconductor with sufficiently reduced impurities in the channel formation region of a transistor, stable electrical characteristics can be imparted.

[0408] This embodiment can be implemented in appropriate combination with at least some of the other embodiments described in this specification.

[0409] (Embodiment 4) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to FIGS. 30 to 32.

[0410] The electronic device of this embodiment includes a display device according to one aspect of the present invention. For example, the 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, a touch operation (contact or approach) can be detected, and so on. Thereby, the functionality, convenience, etc. of the electronic device can be enhanced.

[0411] Examples of the electronic device include, in addition to electronic devices having a relatively large screen such as a television device, a desktop or notebook personal computer, a monitor for a computer, a digital signage, and a large game machine such as a pachinko machine, a digital camera, a digital video camera, a digital photo frame, a mobile phone, a portable game machine, a portable information terminal, an audio playback device, and the like.

[0412] The electronic device according to 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, voice, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays).

[0413] The electronic device according to the present embodiment can have various functions. For example, it can have a function of displaying various information (such as 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, a function of reading a program or data recorded on a recording medium, and the like.

[0414] The electronic device 6500 shown in FIG. 30A is a portable information terminal that can be used as a smartphone.

[0415] 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, a light source 6508, and the like. The display unit 6502 has a touch panel function.

[0416] The display device according to one aspect of the present invention can be applied to the display unit 6502.

[0417] FIG. 30B is a schematic cross-sectional view including an end portion on the microphone 6506 side of the housing 6501.

[0418] 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.

[0419] The display panel 6511, the optical member 6512, and the touch sensor panel 6513 are fixed to the protective member 6510 by an adhesive layer (not shown).

[0420] 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.

[0421] 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.

[0422] 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 and fingerprint authentication can be performed.

[0423] Since the display unit 6502 further includes 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.

[0424] FIG. 31A 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 is shown in which the housing 7101 is supported by a stand 7103.

[0425] The display device according to one aspect of the present invention can be applied to the display unit 7000.

[0426] The operation of the television apparatus 7100 shown in FIG. 31A can be performed by an operation switch provided in the housing 7101 or a separate remote control operation unit 7111. 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.

[0427] Note that the television apparatus 7100 has a configuration including a receiver and a modem, etc. 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 can be performed.

[0428] FIG. 31B 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.

[0429] The display device according to one aspect of the present invention can be applied to the display unit 7000.

[0430] FIGS. 31C and 31D show an example of digital signage.

[0431] The digital signage 7300 shown in FIG. 31C 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.

[0432] FIG. 31D 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.

[0433] In FIGS. 31C and 31D, the display device according to an aspect of the present invention can be applied to the display unit 7000.

[0434] The larger the display unit 7000 is, the more information can be provided at once. Also, the larger the display unit 7000 is, the more likely it is to catch people's eyes, and for example, the advertising effect can be enhanced.

[0435] 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.

[0436] Also, as shown in FIGS. 31C and 31D, it is preferable that the digital signage 7300 or the digital signage 7400 can be linked by wireless communication with an information terminal 7311 such as a smartphone or an information terminal 7411 held by the user. 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 of the display unit 7000 can be switched.

[0437] In addition, it is also 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.

[0438] The electronic devices shown in FIGS. 32A to 32F include 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.

[0439] The electronic devices shown in FIGS. 32A to 32F have various functions. For example, functions such as displaying various information (still images, moving images, text images, etc.) on the display unit, a touch panel function, a function of displaying a calendar, date, or time, 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 can be included. 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. In addition, the electronic device may be provided with a camera or the like, and have functions such as taking still images, moving images, etc., storing them in a recording medium (external or built-in to the camera), and displaying the taken images on the display unit.

[0440] Details of the electronic devices shown in FIGS. 32A to 32F will be described below.

[0441] FIG. 32A is a perspective view showing a portable information terminal 9101. The portable information terminal 9101 can be used, for example, as 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, image information, etc. on its plurality of surfaces. FIG. 32A shows an example in which three icons 9050 are displayed. Also, information 9051 indicated by a dashed rectangle can be displayed on other surfaces of the display unit 9001. Examples of the information 9051 include notifications of incoming calls such as e-mail, SNS, and telephone, titles, sender names, dates and times, battery remaining amounts, antenna reception strengths, etc. of e-mail, SNS, etc. Alternatively, icons 9050 etc. may be displayed at the position where the information 9051 is displayed.

[0442] FIG. 32B 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 is shown in which information 9052, information 9053, and information 9054 are respectively displayed on different surfaces. 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.

[0443] FIG. 32C 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 data transmission and charging mutually with other information terminals by the connection terminal 9006. Note that the charging operation may be performed by wireless power supply.

[0444] 32D to 32F are perspective views showing a foldable mobile information terminal 9201. FIG. 32D is a perspective view of the mobile information terminal 9201 in an unfolded state, FIG. 32F is a perspective view of the mobile information terminal 9201 in a folded state, and FIG. 32E is a perspective view of the mobile information terminal 9201 in a state in the middle of changing from one of FIG. 32D and FIG. 32F to the other. The mobile information terminal 9201 has excellent portability in a folded state, and has excellent viewability of the display due to a seamless wide display area in an unfolded state. The display unit 9001 of the mobile information terminal 9201 is supported by three housings 9000 connected by hinges 9055. For example, the display unit 9001 can be bent with a radius of curvature of 0.1 mm or more and 150 mm or less.

[0445] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification. [Explanation of symbols]

[0446] SA: light-emitting / receiving element: Tr1-Tr2: transistors: SW1-SW4: switches: CS1-CS2: capacitance: SL: wiring: WX: wiring: AL: wiring: CL: wiring: VCP: wiring: VPI: wiring: VL1: wiring: SR: light-emitting / receiving element: ELG: light-emitting element: ELB: light-emitting element: M1-M3: transistors: M10-M14: transistors: C1-C2: capacitance: GL: wiring: TX: wiring: SE: wiring: RS: wiring: REN: wiring: SL1-SL3: wiring: V0L: wiring: 10: display device: 11: display unit: 12: drive circuit unit: 13: drive circuit unit: 14: drive circuit unit: 15: circuit unit: 20B: sub-pixel: 20G: sub-pixel: 20R: sub-pixel: 21B: circuit: 21G: circuit: 21R: circuit: 22: circuit: 30: pixel: 30B: pixel: 30G: pixel

Claims

[Claim 1] a first to fourth switches, a first transistor, a second transistor, a capacitance, a first wiring, a second wiring, and a light emitting / receiving element; the first switch has one electrode electrically connected to the first wiring and the other electrode electrically connected to the gate of the first transistor and one electrode of the capacitor; the second switch has one electrode electrically connected to one of the source and drain of the first transistor, one electrode of the light emitting / receiving element, and the other electrode of the capacitor, and has the other electrode electrically connected to the gate of the second transistor and one electrode of the third switch; the third switch has the other electrode electrically connected to the second wiring, the fourth switch has one electrode electrically connected to one electrode of the second switch and the other electrode electrically connected to one electrode of the light emitting / receiving element; The light emitting / receiving element has a function of emitting light of a first color and a function of receiving light of a second color.

Images