Vehicle controller

Abstract

To provide a vehicle controller with high safety.SOLUTION: A vehicle controller has an operating unit, a light receiving and emitting unit, and a control unit. The operating unit has a steering wheel having a rim, a hub, and spokes. The rim is connected to the hub via the spokes. The light receiving and emitting unit is provided along the surface of the rim. The light receiving and emitting unit has a first light emitting element and a first light receiving element. The first light emitting element has a function to emit light in a first wavelength region. The first light emitting element has a function to receive the light in the first wavelength region and convert the light into electric signals. The first light emitting element and the first light receiving element are arranged side by side on the same plane. The light receiving and emitting unit has a function to sequentially output light reception data to the control unit. The control unit has a function to acquire biological information on a driver from a plurality of pieces of light reception data, and execute processing according to the biological information.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] One aspect of the present invention relates to a control device for a moving body such as a vehicle. One aspect of the present invention relates to a light emitting and receiving device. One aspect of the present invention relates to a biosensor. One aspect of the present invention relates to a biometric authentication technique.

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

Background Art

[0003] For a driver while driving a vehicle, accidents caused by drowsiness are one of the most common accidents, and various methods for monitoring the driver's wakefulness state have been studied. For example, Patent Document 1 discloses a technique for determining the driver's activity level from the acceleration of the vehicle and the driver's heart rate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] One aspect of the present invention has an object of providing a highly safe vehicle control device. One aspect of the present invention has an object of providing a highly convenient vehicle control device. One aspect of the present invention has an object of monitoring the driver's state without making the driver aware. One aspect of the present invention has an object of providing a vehicle control device or a vehicle control method having a novel configuration.

[0006] One aspect of the present invention aims to provide a new electronic device, mobile body, vehicle, device, system, program, or method that utilizes biological information. One aspect of the present invention aims to provide an electronic device, mobile body, vehicle, device, system, program, or method having a novel configuration. One aspect of the present invention aims to reduce at least one of the problems of the prior art.

[0007] 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 necessarily have 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

[0008] One aspect of the present invention is a vehicle control device including an operation unit, a first light transmitting and receiving unit, and a control unit. The operation unit includes a steering wheel having a rim, a hub, and spokes. The rim is connected to the hub via the spokes. The first light transmitting and receiving unit is provided along the surface of the rim. The first light transmitting and receiving unit includes a first light emitting element and a first light receiving element. The first light emitting element has a function of emitting light in a first wavelength range. The first light receiving element has a function of receiving light in the first wavelength range and converting it into an electrical signal. The first light emitting element and the first light receiving element are arranged side by side on the same plane. The first light transmitting and receiving unit has a function of sequentially outputting received light data to the control unit. The control unit has a function of acquiring the biological information of the driver from a plurality of received light data and executing processing according to the biological information.

[0009] Also, in the above, the biological information is preferably one or more of a pulse wave, heartbeat, pulse, and arterial blood oxygen saturation.

[0010] Also, in the above, the biological information is preferably information on a vein, fingerprint, or palmprint.

[0011] In addition, in any of the above cases, it is preferable to further include a second light transmitting and receiving unit. At this time, the second light transmitting and receiving unit is provided along the surface of the hub or the spoke. The second light transmitting and receiving unit includes a second light emitting element and a second light receiving element. The second light emitting element preferably has a function of emitting light in a second wavelength range, and the second light receiving element preferably has a function of receiving light in the second wavelength range and converting it into an electrical signal.

[0012] In addition, in any of the above cases, the light in the first wavelength range preferably includes infrared light. Also, the light in the second wavelength range preferably includes infrared light.

[0013] In addition, in any of the above cases, the first light transmitting and receiving unit preferably further includes a third light emitting element. At this time, the third light emitting element preferably has a function of emitting light in a third wavelength range including visible light.

[0014] In addition, in any of the above cases, the second light transmitting and receiving unit preferably further includes a fourth light emitting element. At this time, the fourth light emitting element preferably has a function of emitting light in a fourth wavelength range including visible light.

[0015] In addition, in any of the above cases, the first light emitting element preferably has a stacked structure in which a first electrode, a light emitting layer, and a common electrode are stacked. Further, the first light receiving element preferably has a stacked structure in which a second electrode, an active layer, and a common electrode are stacked. At this time, the light emitting layer and the active layer preferably contain different organic compounds from each other. Also, the first electrode and the second electrode are preferably provided separately on the same plane. Further, the common electrode is preferably provided to cover the light emitting layer and the active layer.

[0016] Alternatively, in any of the above, it is preferable that the first light-emitting element has a stacked structure in which a first electrode, a common layer, a light-emitting layer, and a common electrode are stacked. Further, it is preferable that the first light-receiving element has a stacked structure in which a second electrode, a common layer, an active layer, and a common electrode are stacked. At this time, it is preferable that the light-emitting layer and the active layer each contain different organic compounds. Also, it is preferable that the first electrode and the second electrode are provided separately on the same plane. Further, it is preferable that the common electrode is provided to cover the light-emitting layer and the active layer, and the common layer is provided to cover the first electrode and the second electrode.

Advantages of the Invention

[0017] According to one aspect of the present invention, a highly safe vehicle control device can be provided. Alternatively, a highly convenient vehicle control device can be provided. Alternatively, the driver's state can be monitored without the driver being aware. Alternatively, a vehicle control device or a vehicle control method having a novel configuration can be provided.

[0018] Also, according to one aspect of the present invention, a new electronic device, moving body, vehicle, device, system, program, or method using biological information can be provided. Alternatively, an electronic device, moving body, vehicle, device, system, program, or method having a novel configuration can be provided. Alternatively, at least one of the problems of the prior art can be at least reduced.

[0019] Note that the description of these effects does not prevent the existence of other effects. Note that one aspect of the present invention does not necessarily have all of these effects. Note that other effects can be extracted from the description of the specification, drawings, claims, etc.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Embodiment for Carrying Out the Invention

[0021] Hereinafter, embodiments will be described with reference to the drawings. However, the embodiments can be implemented in many different modes, 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 content of the following embodiments.

[0022] 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 will be omitted. Also, when referring to similar functions, the hatch patterns may be the same and may not be particularly labeled.

[0023] In each of the drawings described in this specification, the size, layer thickness, or area of each component may be exaggerated for clarity. Therefore, it is not necessarily limited to that scale.

[0024] Note that ordinal numbers such as "first" and "second" in this specification are given to avoid confusion of components and are not numerically limiting.

[0025] (Embodiment 1) In this embodiment, a vehicle control device according to an aspect of the present invention will be described.

[0026] [Configuration Example 1] FIG. 1A shows a block diagram of a vehicle control device 10 exemplified below. The vehicle control device 10 includes a light emitting and receiving unit 20, a control unit 30, an operation unit 40, and the like.

[0027] The light receiving and emitting unit 20 has a function of acquiring light reception data including the driver's biometric information, and a function of outputting the light reception data to the control unit 30. The control unit 30 has a function of generating (acquiring) data (also referred to as biometric data) including the driver's biometric information based on the light reception data supplied from the light receiving and emitting unit 20, and a function of executing various processes based on the biometric data. Further, the operation unit 40 corresponds to an operation means by which the driver operates the vehicle. The light receiving and emitting region of the light receiving and emitting unit 20 is provided along a portion that the driver grips or touches or the like of the operation unit 40.

[0028] The light receiving and emitting unit 20 has a function of, for example, irradiating a part of the driver's body with light and acquiring the reflected light as light reception data. The light receiving and emitting unit 20 can acquire biometric data such as fingerprints and palm prints by imaging a part of the skin. By using the biometric data for authentication, a key (including a smart key) for starting the vehicle becomes unnecessary, and a vehicle that can start the engine (or power supply) by biometric authentication without having a key can be realized.

[0029] Here, since the reflectance of light by a person's skin changes periodically due to blood flow, pulse wave data can be acquired from the time change of the received light luminance that can be repeatedly acquired by the light receiving and emitting unit 20 through light reception. Various other vital data can be further acquired from the pulse wave. For example, the heart rate can be obtained from the period of the pulse wave. Also, arterial blood oxygen saturation (SpO2) can be measured using two pieces of light reception data acquired using lights of different wavelengths (for example, two types: infrared light and red light). Also, a high-precision pulse wave acquired by increasing the sampling frequency can be used to acquire the stress level, vascular age, and the like. In addition, it is also possible to estimate the degree of progression of arteriosclerosis, and estimate blood pressure based on separately measured electrocardiogram and pulse wave.

[0030] The biological data that can be used by the control unit 30 can be roughly classified into vital data and biometric data (biometric metrics data). Vital data is data related to life information derived from a person's life activities, and data such as pulse wave, heart rate, pulse, arterial blood oxygen saturation, and blood pressure correspond to this. On the other hand, biometric metrics data is data derived from a person's physical characteristics and can be used for personal authentication (biometric authentication), and data such as fingerprints, palm prints, vein shapes (including venous and arterial shapes), irises, and voiceprints correspond to this. Also, data derived from a person's behavioral characteristics (for example, the position where the steering wheel is grasped) can also be included in the biometric metrics data.

[0031] As the light irradiated by the light emitting and receiving unit 20 onto a part of the driver's body, visible light, infrared light, or ultraviolet light can be used. In particular, it is preferable that the light includes infrared light, preferably near-infrared light. Since such light is not visible to the driver, it is preferable because imaging can always be performed without interfering with the driver's driving.

[0032] As shown in Fig. 1A, the light emitting and receiving unit 20 includes a light emitting element 21, a light receiving element 22, a driving circuit 23, and a reading circuit 24. The control unit 30 includes a data generation unit 31, a determination unit 32, a processing unit 33, etc. The operation unit 40 includes at least a steering wheel 41. The steering wheel 41 includes a rim 42, a hub 43, and spokes 44.

[0033] In the light emitting and receiving unit 20, the light emitting element 21 and the light receiving element 22 are preferably arranged side by side on the same plane. The light receiving element 22 functions as a photoelectric conversion element that receives incident light and converts it into an electrical signal. The light receiving element 22 has sensitivity to at least a part of the light emitted by the light emitting element 21. In particular, it is preferable that the light emitting element 21 emits light in a wavelength range including infrared light and the light receiving element 22 also has sensitivity to light in a wavelength range including infrared light.

[0034] The light emitted by the light-emitting element 21 preferably includes infrared light, preferably near-infrared light. In particular, near-infrared light having one or more peaks in the range of 700 nm or more and 2500 nm or less can be preferably used. In particular, by using light having one or more peaks in the range of 750 nm or more and 1000 nm or less, the range of material selection for the active layer of the light-receiving element 22 is widened, which is preferable.

[0035] In particular, in the light-emitting and light-receiving unit 20, it is preferable that a plurality of light-emitting elements 21 and a plurality of light-receiving elements 22 are provided. At this time, the light-emitting element 21 and the light-receiving element 22 are preferably arranged side by side on the same plane. Further, the light-emitting element 21 and the light-receiving element 22 are preferably arranged alternately in one direction or alternately in a matrix.

[0036] As the light-emitting element 21, it is preferable to use an EL element such as an OLED (Organic Light Emitting Diode) or a QLED (Quantum-dot Light Emitting Diode). Examples of the light-emitting substance included in the EL element include a substance that emits fluorescence (fluorescent material), a substance that emits phosphorescence (phosphorescent material), a substance that exhibits thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) material), and an inorganic compound (such as a quantum dot material).

[0037] As the light-receiving element 22, for example, a pn-type or pin-type photodiode can be used. The light-receiving element functions as a photoelectric conversion element that detects the light incident on the light-receiving element and generates charges. The amount of charges generated by the photoelectric conversion element is determined according to the amount of incident light. In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light-receiving element. The organic photodiode is easy to thin, lighten, and increase in area, and has a high degree of freedom in shape and design, so it can be applied to various devices.

[0038] Further, it is preferable to use an organic compound for the active layer of the light receiving element 22. At this time, it is preferable to provide one electrode (also referred to as a pixel electrode) of the light emitting element 21 and the light receiving element 22 on the same plane. Further, it is more preferable that the other electrode of the light emitting element 21 and the light receiving element 22 is an electrode (also referred to as a common electrode) formed by a continuous single conductive layer. Further, it is more preferable that the light emitting element 21 and the light receiving element 22 have a common layer. Thereby, the manufacturing process when manufacturing the light emitting element 21 and the light receiving element 22 can be simplified, the manufacturing cost can be reduced, and the manufacturing yield can be improved.

[0039] The drive circuit 23 includes a circuit for controlling the light emission of the light emitting element 21 and a circuit for controlling the light reception of the light receiving element 22. For example, in the case where the light emitting and receiving unit 20 has a configuration in which a plurality of pixels including the light emitting element 21 and the light receiving element 22 are arranged in a matrix, the drive circuit 23 includes a pixel circuit, a scanning line drive circuit, a signal line drive circuit, etc. included in the pixels.

[0040] The readout circuit 24 has a function of generating received light data based on the electrical signal output by the light receiving element 22 and outputting it to the control unit 30. For example, the readout circuit 24 includes an amplifier circuit, an AD conversion circuit, etc. The received light data output from the readout circuit 24 to the control unit 30 is preferably digital data.

[0041] The light emitted from the light emitting element 21 is reflected by an object that touches or approaches the light emitting and receiving surface of the light emitting and receiving unit 20 and enters the light receiving element 22. The light receiving element 22 outputs an electrical signal corresponding to the amount of incident light. Thereby, the contact or approach of the object can be detected.

[0042] The data generation unit 31 has a function of generating biological data for output to the determination unit 32 from the received light data input from the light emitting and receiving unit 20.

[0043] Examples of vital data, which is one type of biological data, include data such as pulse waves and heart rates generated from time-series data including data sampled within a certain period, or various data calculated from pulse waves. Also, imaging data such as fingerprints, palm prints, and veins generated from still images, etc. can be used as biometric data and is included in biological data.

[0044] The determination unit 32 has a function of determining whether to cause the processing unit 33 to execute processing based on the biological data supplied from the data generation unit 31. Also, the determination unit 32 has a function of selecting the processing to be executed by the processing unit 33 based on the biological data.

[0045] Since the light emitting and receiving unit 20 and the data generation unit 31 can periodically and continuously acquire various vital data or biometric data, the determination unit 32 can use these vital data or biometric data for personal authentication, driver status management, etc.

[0046] For example, biological data obtained by using visible light and infrared rays includes fingerprints, palm prints, vein shapes, pulse waves, respiration rates, heartbeats, oxygen saturation, blood glucose levels, neutral fat concentrations, etc. Also, biological data that can be acquired by other means includes facial expressions, complexion, pupils, voiceprints, etc. Using such various biological data is preferable because it can comprehensively determine the user's health status.

[0047] For each of the plurality of measured biological data, it is possible to determine whether it is a normal value or an abnormal value individually, and based on these multiple determination results, determine the processing. Or, for each of the plurality of measured biological data, determine the driver's state (for example, determine from the numerical value of the heartbeat that it is high, low, or normal), and based on these multiple determination results, determine the processing. Such a method has the merit that the basis for the obtained determination result is clear.

[0048] On the one hand, for all the measured biological data, features may be extracted, and a process may be determined from the features. According to such a method, not only individual biological data but also determination based on the correlation relationship of a plurality of biological data is easy.

[0049] As a classifier or discriminator for determining a process from various biological data, it is preferable to use a machine learning model learned by machine learning. Machine learning is roughly classified into supervised machine learning, unsupervised machine learning, and outlier detection.

[0050] Examples of supervised machine learning include the k-nearest neighbor method, naive Bayes classifier, decision tree, support vector machine, random forest, neural network, etc. In particular, by using a neural network, it is also possible to learn at the stage of feature extraction, so it is suitable for a method of extracting features from a plurality of information.

[0051] Examples of feature extraction methods used in unsupervised machine learning include principal component analysis (PCA), non-negative matrix factorization (NMF), etc. Examples of classifiers include k-means clustering, DBSCAN, etc.

[0052] For the determination of a plurality of acquired biological data, a supervised machine learning model and an unsupervised machine learning model may be used in combination. At this time, as the label of each classification classified by the unsupervised machine learning model, the label used in another supervised machine learning model may be used.

[0053] Outlier detection detects whether the acquired biological data or the features obtained from one or a plurality of biological data are outliers outside the normal region. When detected as an outlier, it is presumed that the driver's state is likely to deviate from normal.

[0054] Examples of models for detecting outliers include the k-nearest neighbor method, Local Outlier Factor, One-class SVM, and Mahalanobis distance. As for outlier detection, it is effective to use multi-dimensional data that combines various types of information. By performing outlier detection based on multiple pieces of information, false detection can be prevented. Also, when the biological data is information that changes over time according to the user's state (such as pulse rate and respiratory rate), methods such as the neighborhood method using a sliding window, the dynamic time warping (DTW) method, and the singular spectral transformation method may be used. Moreover, for biological information that changes periodically, outliers from a prediction model may be detected using, for example, LSTM (Long Short Term Memory).

[0055] Further, the determination unit 32 may have a function of performing a process (authentication process) of collating the fingerprint, palmprint, or blood vessel shape information input from the data generation unit 31 with the fingerprint, palmprint, or blood vessel shape information of the driver stored in advance and determining whether they match. As methods used in the authentication process executed by the determination unit 32, for example, methods such as a template matching method that compares two images and uses their similarity, or a pattern matching method can be used. Also, fingerprint authentication processing may be executed by inference using machine learning. At this time, the authentication process is preferably performed by inference using a neural network in particular.

[0056] The processing unit 33 has a function of performing various processes according to the result of the determination unit 32.

[0057] For example, when the determination unit 32 authenticates the driver based on biometric information such as the driver's fingerprint, palm print, or vein, the processing unit 33 can shift the vehicle to a state where it can be driven (also referred to as an idling state). In addition, when the driver is authenticated by the determination unit 32, the processing unit 33 may execute processing to adjust the environment inside the vehicle to the driver's preferred environment. For example, it is preferable that the processing unit 33 executes one or more of the following after authentication: adjustment of the seat position, adjustment of the steering wheel position, adjustment of the orientation of the side mirror and the rearview mirror, setting of brightness, setting of the air conditioner, setting of the speed and frequency of the windshield wipers, setting of the volume of the audio, reading of the audio playback list, etc.

[0058] Also, when the determination unit 32 determines the degree of the driver's wakefulness, processing is executed by the processing unit 33 according to that degree. Examples include changing the brightness inside the vehicle and playing audio so as to prompt the driver's wakefulness. Also, when it is determined that the driver is in a state where driving is impossible, for example, the driving mode of the vehicle can be changed to the emergency automatic driving mode, the hazard lamp can be blinked, the vehicle can be moved to the road shoulder, and processing such as contacting the police, emergency services, and insurance companies can be performed.

[0059] In addition, the determination unit 32 may have functions such as determining the presence or absence of alcohol intake from biometric data and determining whether an onset of a heart disease or the like has occurred.

[0060] In addition, the determination unit 32 may have a function of constantly monitoring whether the driver is gripping the steering wheel 41. Depending on the type of automatic driving, it is required to always grip the steering wheel 41. For example, when the determination unit 32 determines that the driver has released their hand from the steering wheel 41, the processing unit 33 may execute processing to warn the driver to grip the steering wheel 41.

[0061] The rim 42 of the steering wheel 41 functions as a grip portion for the driver to hold and has an annular shape. Further, the hub 43 is connected to a shaft (shaft) extending from the vehicle and is located at the center of the steering wheel 41. Further, the spoke 44 is a portion connecting the rim 42 and the hub 43. The spoke 44 may be one, but it is preferable to have two or more because the strength of the steering wheel 41 is increased. For example, it is preferable that a plurality (typically two to four) of the spokes 44 are provided radially around the hub 43.

[0062] An operation switch or an operation panel (touch panel) may be provided on the hub 43 and the spoke 44.

[0063] In addition to the steering wheel 41, the operation unit 40 may include operation levers such as a column shift and a paddle shift, and operation levers such as a wiper and a turn signal.

[0064] Here, at least a part of the light emitting and receiving unit 20 is provided along the surface of the rim 42 of the steering wheel 41. Thereby, when the driver grips the rim 42, the light receiving data of a part of the palm can be acquired.

[0065] 〔Configuration Example 1-1〕 FIG. 1B shows a perspective view of an example of a steering wheel 41 provided with the light emitting and receiving unit 20. In FIG. 1B, a part of the shaft 45 connected to the hub 43 is also shown.

[0066] The light emitting and receiving unit 20 is provided along the surface of the rim 42 having an annular shape. The rim 42 is processed so that the surface located in the front as viewed from the driver is flat, and the light emitting and receiving unit 20 is provided along the flat surface.

[0067] On the right side of FIG. 1B, an enlarged view of a part of the light emitting and receiving unit 20 is shown. In the light emitting and receiving unit 20, light emitting elements 21 and light receiving elements 22 are alternately arranged in a matrix. Note that the arrangement method of the light emitting elements 21 and the light receiving elements 22 is not limited to this, and various arrangement methods can be adopted.

[0068] FIG. 1C shows a state where the left hand 51L and the right hand 51R of the driver are gripping the rim 42. At this time, when the light emitting element 21 emits light and the light receiving element 22 receives the light, it is possible to image a part of the palms of the left hand 51L and the right hand 51R of the driver. Since the light emitting and receiving unit 20 has an annular upper surface shape similar to the surface of the rim 42, it is always possible to perform imaging regardless of which position of the rim 42 the left hand 51L and the right hand 51R are gripping.

[0069] Since the light emitting and receiving unit 20 is arranged on the surface of the rim 42 on the driver's side, the light emitting and receiving unit 20 is located inside the driver's field of view. At this time, by using a light emitting element that emits infrared light as the light emitting element 21, imaging can be performed without causing the driver to feel glare.

[0070] Note that a light emitting element that emits visible light may be used as the light emitting element 21. In this case, it is important to suppress the emission luminance during imaging to a level that does not cause glare to the driver. For example, it is preferable to suppress the emission luminance of the light emitting element 21 at night rather than during the day.

[0071] FIG. 2A shows an example of a schematic cross-sectional view of the rim 42.

[0072] The rim 42 has a member 42a and a member 42b. The member 42b has translucency. The light emitting and receiving unit 20 is located inside the rim 42 and is provided along a part of the member 42b. The light emitting and receiving unit 20 can emit light 25 through the translucent member 42b. Also, the reflected light 25r reflected by the object is transmitted through the member 42b and is incident on the light emitting and receiving unit 20.

[0073] Here, in FIG. 2A, a part of the surface of the member 42b (the surface on the side where the hand touches) has a flat shape. As a result, the imaging surface can be made flat, so that when imaging an image used for authentication, such as a fingerprint, a palm print, or a blood vessel shape, an image with less distortion can be captured.

[0074] Also, as shown in FIG. 2B, the surface may be a curved surface. As a result, the cross-section of the rim 42 can be made into an annular shape, so that it does not give the driver a sense of discomfort compared to the case where there is a flat portion, and it can be made easier to grip. Also, a part of the member 42b can function as a lens.

[0075] As shown in FIGS. 2A and 2B, the light emitting and receiving unit 20 is preferably attached to a flat surface. As a result, it is not necessary to impart flexibility to the light emitting and receiving unit 20, so the manufacturing cost can be suppressed.

[0076] 〔Configuration Example 1-2〕 The steering wheel 41 shown in FIG. 3A is an example in which the light emitting and receiving unit 20 is provided along the outer periphery of the rim 42.

[0077] FIG. 3B shows a schematic cross-sectional view of the rim 42 in the cut surface A shown in FIG. 3A. FIG. 3B approximately coincides with FIG. 2A rotated 90 degrees clockwise.

[0078] In the configuration shown in FIG. 3A, the strip-shaped light emitting and receiving unit 20 is attached along the member 42b. Since the light emitting and receiving unit 20 needs to be attached to a curved surface, it is preferably flexible. For example, for the light emitting and receiving unit 20, it is preferable to use an organic resin for the base material on which the light emitting element 21 and the light receiving element 22 are supported. Alternatively, as the base material, a thin glass or the like having flexibility may be used.

[0079] 〔Configuration Example 1-3〕 The steering wheel 41 shown in FIG. 3C shows an example in which the light emitting and receiving unit 20 is arranged on most of the surface of the rim 42.

[0080] FIG. 3D shows a schematic cross-sectional view of the rim 42. The rim 42 has a member 42a and a member 42b. The member 42a is located on the back side of the rim 42 (the side opposite to the driver side). The light emitting and receiving unit 20 is provided along the inner surface of the member 42b. The inner surface of the member 42b is a curved surface (three-dimensional curved surface) that is not a developable surface, and the light emitting and receiving surface of the light emitting and receiving unit 20 also forms a three-dimensional curved surface. Therefore, when attaching the light emitting and receiving unit 20 along the inner surface of the member 42a, it is preferable that the light emitting and receiving unit 20 is stretchable. For example, for the light emitting and receiving unit 20, it is preferable to use an elastic body such as rubber for the base material on which the light emitting element 21 and the light receiving element 22 are supported.

[0081] By adopting the configuration shown in FIG. 3C, the imaging area can be increased, so the imaging sensitivity can be improved. For example, when estimating the pulse wave from the temporal change in the reflectance of the skin, it is preferable because the higher the sensitivity, the higher the accuracy. In addition, since fingerprints, palm prints, blood vessel shapes, etc. used for authentication can be imaged over a wide range, the authentication accuracy can be improved.

[0082] [Configuration Example 2] Hereinafter, a configuration including a plurality of light emitting and receiving units will be described.

[0083] [Configuration Example 2-1] FIG. 4A shows an example in which the light emitting and receiving unit 20a is provided along the driver side surface of the hub 43.

[0084] Similar to the light emitting and receiving unit 20, the light emitting and receiving unit 20a has a configuration in which a light emitting element and a light receiving element are arranged side by side. The light receiving element is a photoelectric conversion element that is sensitive to light in the wavelength range emitted by the light emitting element. The light emitting and receiving unit 20 and the light emitting and receiving unit 20a may have different wavelengths of light emitted by their respective light emitting elements, or may be configured to emit light of the same wavelength.

[0085] For example, using the light emitting and receiving unit 20a, biometric information such as fingerprints and palm prints can be acquired for authentication. FIG. 4B shows a state in which the hand 51 is held over the light emitting and receiving unit 20a.

[0086] Since the light emitting and receiving units are provided on the rim 42 and the hub 43 respectively, the information obtained by the light emitting and receiving unit 20 provided on the rim 42 and the information obtained by the light emitting and receiving unit 20a provided on the hub 43 may be made different from each other. For example, the light emitting and receiving unit 20a may acquire an image for authentication as information, and the light emitting and receiving unit 20 may acquire the temporal change of the skin reflectance as information. At this time, since it is necessary for the light emitting and receiving unit 20a to capture an image with high resolution, the light receiving elements 22 are arranged at high density. On the other hand, since the light emitting and receiving unit 20 does not require high resolution, the light receiving elements 22 are arranged at a lower density than the light emitting and receiving unit 20a. In this way, the configuration of the light emitting and receiving unit can be made different according to the information to be acquired.

[0087] In addition, the light emitting and receiving unit 20a provided on the hub 43 may have a function of displaying an image and a function of detecting a touch operation or a gesture operation. For example, the light emitting and receiving unit 20a may function as a touch panel. Thereby, various information can be displayed on the light emitting and receiving unit 20a. For example, the light emitting and receiving unit 20a can also be used as a display unit of a navigation system.

[0088] 〔Configuration Example 2-2〕 FIG. 4C shows an example in which a light emitting and receiving unit is provided along the surface of the spoke 44.

[0089] In FIG. 4C, among the three spokes 44, the light emitting and receiving unit 20b is provided on the lower spoke 44, a plurality of light emitting and receiving units 20c are provided on the left spoke 44, and a plurality of light emitting and receiving units 20d are provided on the right spoke 44. Note that the number of spokes 44 and the number of light emitting and receiving units are not limited to this, and can be appropriately changed according to the purpose.

[0090] The light emitting and receiving unit 20b, the light emitting and receiving unit 20c, and the light emitting and receiving unit 20d each have a configuration in which a light emitting element and a light receiving element are arranged side by side in the same manner as the light emitting and receiving unit 20.

[0091] For example, the light receiving and emitting unit 20b can acquire the fingerprint information of the driver and perform authentication using this information. In FIG. 4D, a state where a finger of the hand 51 is held over the light receiving and emitting unit 20b is shown.

[0092] In addition, it is preferable that the light receiving and emitting unit 20c and the light receiving and emitting unit 20d each function as a touch sensor. By touching the light receiving and emitting unit 20c, the light receiving and emitting unit 20d, etc., the driver can operate a navigation system, an audio system, a call system, etc. possessed by the vehicle. Further, it may be configured to enable various operations such as adjusting the rearview mirror, adjusting the side mirror, turning on and off the interior lighting and adjusting the brightness, and opening and closing the window.

[0093] In addition, it is preferable that the light receiving and emitting unit 20b, the light receiving and emitting unit 20c, and the light receiving and emitting unit 20d include a light emitting element that emits visible light. Alternatively, it may include both a light emitting element that emits visible light and a light emitting element that emits infrared light. Thereby, even at night, the position of the light receiving and emitting unit can be shown to the driver. Alternatively, uneven portions for indicating the position of the light receiving and emitting unit may be arranged on the surface of the light receiving and emitting unit 20b, the light receiving and emitting unit 20c, and the light receiving and emitting unit 20d or in the vicinity thereof.

[0094] In the above Configuration Example 2-1 and Configuration Example 2-2, the light receiving and emitting unit 20 provided on the rim 42 is shown having the same configuration as in FIG. 1B etc., but it is not limited to this, and the configuration shown in FIG. 3A or FIG. 3B can also be applied.

[0095] In the above description, the light emitting and receiving units 20 provided on the rim 42 have all been described as being provided continuously along the circumferential direction of the rim 42. However, the light emitting and receiving units 20 do not necessarily have to be in a continuous annular shape, and may have an arcuate upper surface shape along the surface of the rim 42. That is, there may be portions where the light emitting and receiving units 20 are not provided in the circumferential direction of the rim 42. Further, a plurality of light emitting and receiving units 20 may be arranged along the surface of the rim 42. Also in that case, the plurality of light emitting and receiving units 20 may be arranged such that the adjacent two light emitting and receiving units 20 overlap each other to form a continuous light emitting and receiving region along the circumferential direction of the rim 42.

[0096] 〔Configuration example of light emitting and receiving unit〕 Hereinafter, a configuration example of a light emitting and receiving unit including two or more types of light emitting elements will be described. The light emitting and receiving units exemplified below can be used not only as a light source for imaging but also for displaying an image. That is, the light emitting and receiving units exemplified below also function as a display unit. Such a light emitting and receiving unit can be applied to the above-described light emitting and receiving unit 20 and light emitting and receiving units 20a to 20d and the like.

[0097] Figures 4E to 4G show enlarged views of the light emitting and receiving unit.

[0098] The light emitting and receiving unit shown in Figure 4E includes a light emitting element 21B that emits blue light, a light emitting element 21IR that emits infrared light, and a light receiving element 22. The light receiving element 22 is a photoelectric conversion element that has sensitivity to at least infrared light. The light receiving element 22 may have sensitivity to blue and infrared light.

[0099] The light emitting and receiving unit shown in Figure 4E can display a blue image, light up in blue, etc. Blue light is less likely to cause glare and is less likely to interfere with driving even when lit at night, so it is preferable. Note that the visible light emitting element provided in the light emitting and receiving unit is not limited to a blue light emitting element, and other color light emitting elements such as red and green may be used.

[0100] The light emitting and receiving unit shown in Fig. 4F includes a light emitting element 21R that emits red light, a light emitting element 21G that emits green light, a light emitting element 21B that emits blue light, a light emitting element 21IR that emits infrared light, and a light receiving element 22. The light receiving element 22 is a photoelectric conversion element that has sensitivity to at least infrared light. The light receiving element 22 may have sensitivity to at least one of red, blue, and green.

[0101] The light emitting and receiving unit shown in Fig. 4F can display a full-color image. Also, even in a state where no image is displayed, that is, in a state where no visible light is emitted from the light emitting and receiving unit, imaging can be performed using infrared light.

[0102] The light emitting and receiving unit shown in Fig. 4G includes a light emitting element 21R that emits red light, a light emitting element 21G that emits green light, a light emitting element 21B that emits blue light, and a light receiving element 22. The light receiving element 22 has sensitivity to at least one of at least red, blue, and green.

[0103] The light emitting and receiving unit shown in Fig. 4G has a function of imaging using visible light instead of infrared light as a light source. Also, a full-color image can be displayed. Further, since the light emitting element 21IR is not provided as compared with Fig. 4F, pixels can be arranged at a high density, and a higher-definition image can be captured. Alternatively, since the area of the light receiving element can be increased, the sensitivity of the light receiving element can be increased. Alternatively, since the area of each light emitting element can be increased, the luminance of the light emission can be increased.

[0104] [Example of operation method] Hereinafter, an example of an operation method of the vehicle control device 10 according to one aspect of the present invention will be described.

[0105] Fig. 5 is a flowchart relating to the operation of the vehicle control device 10. The flowchart shown in Fig. 5 includes steps S0 to S6.

[0106] First, in step S0, the operation is started.

[0107] In step S1, the light receiving and emitting unit 20 acquires light reception data. Specifically, the light emitting element 21 is caused to emit light, the light receiving element 22 receives the light, and the readout circuit 24 executes the readout of the light reception data. Also, in step S1, the light reception data may be output from the readout circuit 24 to the control unit 30.

[0108] In step S2, the data generation unit 31 extracts biological data. Specifically, the data generation unit 31 generates necessary biological data from the light reception data supplied from the light receiving and emitting unit 20. For example, vital data such as waveform data of a pulse wave, heart rate, pulse rate, blood oxygen saturation, blood pressure, stress level, blood glucose level, body temperature, neutral fat concentration, and blood alcohol concentration can be generated. Also, as biological data, biometric data such as fingerprint, palmprint, and blood vessel shape can be generated.

[0109] In step S3, the determination unit 32 determines whether to execute a process. If the process is to be executed, the flow proceeds to step S4. If the process is not to be executed, the flow returns to step S1.

[0110] In step S3, the determination unit 32 can make a determination based on the above-described biological data. Also, the determination unit 32 may make a determination based on two or more of the above-described biological data.

[0111] In step S4, the processing unit 33 executes the process.

[0112] In step S5, it is determined whether to end. Based on the process executed by the processing unit 33, if the operation is to be ended, the flow proceeds to step S6 and ends. If not (the operation is to continue), the flow returns to step S1.

[0113] The above is an explanation of an example of the operation method.

[0114] In the above-described driving method example, various types of biological data can be used as the biological data that can be used for the determination by the determination unit 32. Then, the processes executed by the processing unit 33 based on the determination by the determination unit 32 also vary widely. An example thereof will be described below.

[0115] FIG. 6 shows a flowchart regarding an operation of determining the driver's wakefulness state and giving a warning to the driver when there is a risk of drowsy driving. In the flowchart shown in FIG. 6, steps S2 to S4 in FIG. 5 are replaced with steps S12 to S14.

[0116] In step S12, the data generation unit 31 extracts the heart rate as vital data.

[0117] In step S13, the determination unit 32 determines whether the wakefulness level is below a certain level based on the change in the heart rate. If the wakefulness level is below a certain level, the process proceeds to step S14. On the other hand, if the wakefulness level exceeds a certain level, the process returns to step S1.

[0118] For example, the determination unit 32 can estimate the driver's wakefulness level from the fact that the heart rate itself slows down and the fluctuation of the heart rate changes.

[0119] In step S14, the processing unit 33 performs a warning process on the driver. As the warning process, by giving a stimulus to the driver's vision, hearing, touch, or smell, the driver can be made aware of a decrease in the wakefulness level or the driver's wakefulness can be promoted. Specifically, the processes executed by the processing unit 33 include playing a sound, increasing the volume, vibrating the seat, seat belt, or steering wheel, changing the brightness inside the vehicle, opening the window, spraying a fragrance from an aroma diffuser, and the like.

[0120] The above is the description of the flowchart in FIG. 6.

[0121] In addition, when the arousal level is too high, since it can be determined that the driver is in an excited state, it is also possible to make the driver aware or execute a process for calming down the driver.

[0122] As described above, the vehicle control device according to one aspect of the present invention can monitor various physical states of the driver and changes thereof from the vital data that can be acquired by the light emitting and receiving unit. Then, various processes can be executed so as to continue safe driving or avoid danger according to the state of the driver.

[0123] [Modification example] One aspect of the present invention can detect the physical or mental state of a user by using the light emitting and receiving unit and execute a process according to the state. Therefore, it can be applied to various uses other than the vehicle control device. Here, an example in which one aspect of the present invention is applied to a game system will be described.

[0124] FIG. 7A shows a game system 60. The game system 60 includes a main body 61, a controller 62, a monitor 63, and the like. The monitor 63 can display the video output from the main body 61. The main body 61 and the controller 62 perform data transmission and reception by wireless communication.

[0125] The controller 62 has a pair of gripping portions, and the light emitting and receiving unit 20 is provided along the surface of the gripping portions. In addition, the controller 62 has a plurality of buttons.

[0126] The controller 62 can output the received light data acquired by the light emitting and receiving unit 20 to the main body 61 in real time by wireless communication.

[0127] The main body 61 can execute a game program. The game program may be installed in a storage area (such as an HDD (Hard Disk Drive) or an SSD (Solid State Disk)) that the main body 61 has, or may be stored in a recording medium such as a flash memory, a Blu-ray disk, or a DVD.

[0128] Based on the received data acquired by the controller 62, the main body 61 can generate vital data. The game program can execute processing based on the vital data.

[0129] Hereinafter, as an example of applying one aspect of the present invention to a soccer game as a game program, an example will be shown.

[0130] In a soccer game, one or more characters that can be operated by a player are set. A plurality of unique parameters that determine individual characteristics are set for the characters. For example, as the unique parameters, there are speed, stamina, concentration, dribbling skill, shooting skill, passing skill, defense skill, etc. The unique parameters can increase or decrease according to the growth level of the character.

[0131] In addition, variable parameters are set for the characters separately from the unique parameters. The variable parameters are parameters that change at any time according to the player's vital data. The types of variable parameters can be the same as the unique parameters. Alternatively, variable parameters may be set as parameters different from the unique parameters.

[0132] Each parameter that determines the characteristics of a character is determined by two, namely, a unique parameter and a variable parameter. For example, the parameter of a character may be simply the sum or product of the unique parameter and the variable parameter, or may be determined based on a predetermined calculation formula.

[0133] Here, depending on the player's vital data, there may be parameters that increase (rise) and parameters that decrease (fall). For example, as the player's heart rate increases, the parameter for concentration decreases, while parameters such as dribbling skills and defense skills increase.

[0134] The received light data acquired by the light emitting and receiving unit 20 of the controller 62 is wirelessly transmitted to the main body 61. The data generation unit in the main body 61 generates vital data based on the received light data. The game program sets the variable parameters of the character based on the vital data. The vital data is generated at any time during play, and the variable parameters of the character are also updated at any time according to the changes in the vital data.

[0135] FIG. 7B shows an example video 70 of a scene where the character 71 operated by the player is about to shoot. In the video 70, in addition to the character 71, a shooting area 72 and information 73 are shown.

[0136] The shooting area 72 indicates the range of the trajectory of the ball after shooting. Since the trajectory of the ball after shooting fits within the shooting area 72, the narrower the shooting area 72, the higher the shooting accuracy. The size, shape, etc. of the shooting area 72 are affected by the parameters of the character such as concentration, shooting skills, etc.

[0137] In the information 73, the current heart rate (65 bpm) of the player is shown together with an image indicating the heart rate. Since the heart rate affects the parameter of the character's concentration, the size, shape, etc. of the shooting area 72 change according to the heart rate.

[0138] For example, in FIG. 7C, the heart rate is 120 bpm, showing a case where the heart rate is much higher than that in FIG. 7B. In FIG. 7C, it can be seen that the shooting accuracy is low because the shooting area 72 is much wider compared to FIG. 7B.

[0139] In this way, by associating the player's vital data with the parameters that determine the characteristics of the character, a game program with a high sense of presence can be provided. Furthermore, using a plurality of controllers 62, multiple players can play simultaneously, or multiple players can play simultaneously online via the Internet.

[0140] The above is the description of the modification example.

[0141] This embodiment can be implemented by appropriately combining at least a part thereof with other embodiments described in this specification.

[0142] (Embodiment 2) In this embodiment, a light emitting and receiving device according to an aspect of the present invention will be described. The display device exemplified below can be suitably used for the light emitting and receiving unit of the vehicle control device described in Embodiment 1.

[0143] The light emitting and receiving unit of the light emitting and receiving device according to an aspect of the present invention has a light receiving element (also referred to as a light receiving device) and a light emitting element (also referred to as a light emitting device). The light emitting and receiving unit has a function of displaying an image using the light emitting element. Furthermore, the light emitting and receiving unit has one or both of a function of imaging and a function of detecting using the light receiving element. Therefore, the light emitting and receiving device according to an aspect of the present invention can also be expressed as a display device, and the light emitting and receiving unit can also be expressed as a display unit.

[0144] Alternatively, the light emitting and receiving device according to an aspect of the present invention may be configured to have a light emitting and receiving element (also referred to as a light emitting and receiving device) and a light emitting element.

[0145] First, a light emitting and receiving device having a light receiving element and a light emitting element will be described.

[0146] The light-receiving and emitting device according to one aspect of the present invention has a light-receiving element and a light-emitting element in a light-receiving and emitting unit. In the light-receiving and emitting device according to one aspect of the present invention, the light-emitting elements are arranged in a matrix in the light-receiving and emitting unit, and an image can be displayed by the light-receiving and emitting unit. Further, in the light-receiving and emitting unit, the light-receiving elements are arranged in a matrix, and the light-receiving and emitting unit also has one or both of an imaging function and a sensing function. The light-receiving and emitting unit can be used for an image sensor, a touch sensor, etc. That is, by detecting light with the light-receiving and emitting unit, an image can be captured, and a touch operation of an object (finger, pen, etc.) can be detected. Furthermore, in the light-receiving and emitting device according to one aspect of the present invention, the light-emitting element can be used as a light source of the sensor. Therefore, it is not necessary to provide a light-receiving unit and a light source separately from the light-receiving and emitting device, and the number of parts of the electronic device can be reduced.

[0147] In the light-receiving and emitting device according to one aspect of the present invention, when the light emitted by the light-emitting element included in the light-receiving and emitting unit is reflected (or scattered) by an object, the light-receiving element can detect the reflected light (or scattered light). Therefore, imaging, detection of touch operations, etc. are possible even in a dark place.

[0148] The light-emitting element included in the light-receiving and emitting device according to one aspect of the present invention functions as a display element (also referred to as a display device).

[0149] As the light-emitting element, it is preferable to use an EL element (also referred to as an EL device) such as an OLED or a QLED. Examples of the light-emitting substance included in the EL element include a substance that emits fluorescence (fluorescent material), a substance that emits phosphorescence (phosphorescent material), an inorganic compound (such as a quantum dot material), and a substance that exhibits thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) material). Further, an LED such as a micro-LED can also be used as the light-emitting element.

[0150] The light-receiving and emitting device according to one aspect of the present invention has a function of detecting light using the light-receiving element.

[0151] When the light-receiving element is used as an image sensor, the light-receiving and emitting device can capture an image using the light-receiving element. For example, the light-receiving and emitting device can be used as a scanner.

[0152] An electronic device to which a light transmitting and receiving device according to one aspect of the present invention is applied can acquire data related to biometric information such as fingerprints and palm prints by using a function as an image sensor. That is, a biometric authentication sensor can be incorporated in the light transmitting and receiving device. By incorporating the biometric authentication sensor in the light transmitting and receiving device, the number of components of the electronic device can be reduced as compared with the case where a biometric authentication sensor is provided separately from the light transmitting and receiving device, and the electronic device can be miniaturized and lightened.

[0153] Also, when the light receiving element is used as a touch sensor, the light transmitting and receiving device can detect a touch operation of an object by using the light receiving element.

[0154] As the light receiving element, for example, a pn-type or pin-type photodiode can be used. The light receiving element functions as a photoelectric conversion element (also referred to as a photoelectric conversion device) that detects light incident on the light receiving element and generates electric charges. The amount of electric charges generated from the light receiving element is determined based on the amount of light incident on the light receiving element.

[0155] In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light receiving element. The organic photodiode is easy to be thinned, lightened, and enlarged in area, and also has a high degree of freedom in shape and design, so that it can be applied to various devices.

[0156] In one aspect of the present invention, an organic EL element (also referred to as an organic EL device) is used as the light emitting element, and an organic photodiode is used as the light receiving element. The organic EL element and the organic photodiode can be formed on the same substrate. Therefore, an organic photodiode can be incorporated in a display device using the organic EL element.

[0157] When forming all the layers that make up an organic EL element and an organic photodiode separately, the number of film formation steps becomes extremely large. However, since an organic photodiode has many layers that can have the same configuration as an organic EL element, the layers that can have the same configuration can be formed in one batch, thereby suppressing an increase in the number of film formation steps.

[0158] For example, one of the pair of electrodes (common electrode) can be a common layer for the light receiving element and the light emitting element. Also, for example, it is preferable that at least one of the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer is a common layer for the light receiving element and the light emitting element. Further, for example, except that the light receiving element has an active layer and the light emitting element has a light emitting layer, the light receiving element and the light emitting element can have the same configuration. That is, a light receiving element can be manufactured by simply replacing the light emitting layer of the light emitting element with an active layer. Thus, by having common layers for the light receiving 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 light receiving and emitting device can be reduced. Also, a light receiving and emitting device having a light receiving element can be manufactured using the existing manufacturing equipment and manufacturing method of a display device.

[0159] Note that the layers common to the light receiving element and the light emitting element may have different functions in the light emitting element and the light receiving element. In this specification, components are named based on their functions in the light emitting element. For example, the hole injection layer functions as a hole injection layer in the light emitting element and functions as a hole transport layer in the light receiving element. Similarly, the electron injection layer functions as an electron injection layer in the light emitting element and functions as an electron transport layer in the light receiving element. Also, the layers common to the light receiving element and the light emitting element may have the same functions in the light emitting element and the light receiving element. The hole transport layer functions as a hole transport layer in both the light emitting element and the light receiving element, and the electron transport layer functions as an electron transport layer in both the light emitting element and the light receiving element.

[0160] Next, a light receiving and emitting device having a light receiving and emitting element and a light emitting element will be described. Note that descriptions of the same functions, actions, effects, etc. as those above may be omitted.

[0161] In the light emitting and receiving device according to one aspect of the present invention, a sub-pixel exhibiting any color has a light emitting and receiving element instead of a light emitting element, and sub-pixels exhibiting other colors have light emitting elements. The light emitting and receiving element has both a function of emitting light (light emitting function) and a function of receiving light (light receiving function). For example, when a pixel has three sub-pixels of a red sub-pixel, a green sub-pixel, and a blue sub-pixel, at least one sub-pixel has a light emitting and receiving element, and the other sub-pixels have light emitting elements. Therefore, the light emitting and receiving unit of the light emitting and receiving device according to one aspect of the present invention has a function of displaying an image using both the light emitting and receiving element and the light emitting element.

[0162] 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 the pixel without increasing the number of sub-pixels included in the pixel. As a result, one or both of an imaging function and a sensing function can be added to the light emitting and receiving unit of the light emitting and receiving device while maintaining the aperture ratio of the pixel (the aperture ratio of each sub-pixel) and the fineness of the light emitting and receiving device. Therefore, the light emitting and receiving device according to one aspect of the present invention can achieve a higher aperture ratio of the pixel and is easily capable of higher fineness compared to the case where a sub-pixel having a light receiving element is provided separately from the sub-pixel having a light emitting element.

[0163] In the light emitting and receiving device according to one aspect of the present invention, the light emitting and receiving element and the light emitting element are arranged in a matrix in the light emitting and receiving unit, and an image can be displayed by the light emitting and receiving unit. Further, the light emitting and receiving unit can be used for an image sensor, a touch sensor, and the like. The light emitting and receiving device according to one aspect of the present invention can use the light emitting element as a light source of the sensor. Therefore, imaging, detection of touch operations, etc. are possible even in a dark place.

[0164] The light-emitting and light-receiving element can be manufactured by combining an organic EL element and an organic photodiode. For example, a light-emitting and light-receiving element can be manufactured by adding an active layer of an organic photodiode to the stacked structure of an organic EL element. Further, in the light-emitting and light-receiving element manufactured by combining an organic EL element and an organic photodiode, an increase in the film-forming process can be suppressed by collectively forming layers that can have the same configuration as the organic EL element.

[0165] For example, one of a pair of electrodes (common electrode) can be a common layer for the light-emitting and light-receiving 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 common layer for the light-emitting and light-receiving 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-emitting and light-receiving element and the light-emitting element can have the same configuration. That is, a light-emitting and light-receiving element can also be manufactured by simply adding the active layer of the light-receiving element to the light-emitting element. Thus, since the light-emitting and light-receiving element and the light-emitting element have a common layer, the number of film-forming times and the number of masks can be reduced, and the manufacturing process and manufacturing cost of the light-emitting and light-receiving device can be reduced. Further, a light-emitting and light-receiving device having a light-emitting and light-receiving element can be manufactured using an existing manufacturing apparatus and manufacturing method of a display device.

[0166] Note that the layers of the light-emitting and light-receiving element may have different functions depending on whether the light-emitting and light-receiving element functions as a light-receiving element or as a light-emitting element. In this specification, components are named based on the functions when the light-emitting and light-receiving element functions as a light-emitting element.

[0167] The light-emitting and light-receiving device of the present embodiment has a function of displaying an image using a light-emitting element and a light-emitting and light-receiving element. That is, the light-emitting element and the light-emitting and light-receiving element function as display elements.

[0168] The light-emitting and light-receiving device of the present embodiment has a function of detecting light using a light-emitting and light-receiving element. The light-emitting and light-receiving element can detect light having a shorter wavelength than the light emitted by the light-emitting and light-receiving element itself.

[0169] When the light-emitting and light-receiving element is used in an image sensor, the light-emitting and light-receiving device of the present embodiment can capture an image using the light-emitting and light-receiving element. Further, when the light-emitting and light-receiving element is used in a touch sensor, the light-emitting and light-receiving device of the present embodiment can detect a touch operation 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. The light-emitting and light-receiving element can be manufactured by adding an active layer of a light-receiving element to the configuration of the above-described light-emitting element. For the light-emitting and light-receiving element, for example, an active layer of a pn-type or pin-type photodiode can be used.

[0171] In particular, it is preferable to use an active layer of an organic photodiode having a layer containing an organic compound for the light-emitting and light-receiving element. Since the organic photodiode 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 devices.

[0172] Hereinafter, a display device, which is an example of the light-emitting and light-receiving device according to one aspect of the present invention, will be described more specifically with reference to the drawings.

[0173] [Configuration Example 1 of Display Device] [Configuration Example 1-1] FIG. 8A shows a schematic diagram of a display panel 200. The display panel 200 includes a substrate 201, a substrate 202, a light-receiving element 212, a light-emitting element 211R, a light-emitting element 211G, a light-emitting element 211B, a functional layer 203, and the like.

[0174] The light-emitting element 211R, the light-emitting element 211G, the light-emitting element 211B, and the light-receiving element 212 are provided between the substrate 201 and the substrate 202. The light-emitting element 211R, the light-emitting element 211G, and the light-emitting element 211B emit red (R), green (G), or blue (B) light, respectively. Hereinafter, when the light-emitting elements 211R, 211G, and 211B are not distinguished, they may be referred to as the light-emitting element 211.

[0175] The display panel 200 has a plurality of pixels arranged in a matrix. One pixel has one or more sub-pixels. One sub-pixel has 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). Further, the pixel has a light-receiving element 212. The light-receiving element 212 may be provided in all pixels or in some pixels. Also, one pixel may have a plurality of light-receiving elements 212.

[0176] FIG. 8A shows a state where the finger 220 touches the surface of the substrate 202. A part of the light emitted from the light-emitting element 211G is reflected at the contact portion between the substrate 202 and the finger 220. Then, a part of the reflected light is incident on the light-receiving element 212, whereby it can be detected that the finger 220 has contacted the substrate 202. That is, the display panel 200 can function as a touch panel.

[0177] The functional layer 203 has a circuit for driving the light-emitting elements 211R, 211G, and 211B, and a circuit for driving the light-receiving element 212. The functional layer 203 is provided with switches, transistors, capacitors, wirings, and the like. When the light-emitting elements 211R, 211G, 211B, and the light-receiving element 212 are driven in a passive matrix system, a configuration without providing switches, transistors, etc. may also be used.

[0178] The display panel 200 preferably has a function of detecting the fingerprint of the finger 220. FIG. 8B schematically shows an enlarged view of the contact portion in a state where the finger 220 touches the substrate 202. Also, FIG. 8B shows the light-emitting elements 211 and the light-receiving elements 212 arranged alternately.

[0179] The finger 220 has fingerprints formed by concave and convex portions. Therefore, as shown in FIG. 8B, the convex portions of the fingerprint are in contact with the substrate 202.

[0180] The light reflected from a certain surface, interface, etc. includes specular reflection and diffuse reflection. Specularly reflected light is highly directional light with the incident angle equal to the reflection angle, while diffusely reflected light is low-directional light with low angular dependence of intensity. The light reflected from the surface of finger 220 has a dominant diffuse reflection component among specular reflection and diffuse reflection. On the other hand, the light reflected from the interface between substrate 202 and the atmosphere has a dominant specular reflection component.

[0181] The intensity of the light reflected at the contact or non-contact surface between finger 220 and substrate 202 and incident on the light receiving element 212 located directly below these is the sum of the specularly reflected light and the diffusely reflected light. As described above, since the substrate 202 and the finger 220 do not contact in the concave portion of the finger 220, the specularly reflected light (indicated by the solid line arrow) is dominant, and since they contact in the convex portion, the diffusely reflected light from the finger 220 (indicated by the dashed line arrow) is dominant. Therefore, the intensity of the light received by the light receiving element 212 located directly below the concave portion is higher than that of the light receiving element 212 located directly below the convex portion. Thereby, the fingerprint of the finger 220 can be imaged.

[0182] By setting the arrangement interval of the light receiving elements 212 to be smaller than the distance between two convex portions of the fingerprint, preferably the distance between an adjacent concave portion and convex portion, a clear fingerprint image can be acquired. Since the interval between the concave and convex portions of a human fingerprint is approximately 200 μm, for example, the arrangement interval of the light receiving elements 212 is 400 μm or less, preferably 200 μm or less, more preferably 150 μm or less, still more preferably 100 μm or less, and still more preferably 50 μm or less, and is 1 μm or more, preferably 10 μm or more, more preferably 20 μm or more.

[0183] An example of the fingerprint image captured by the display panel 200 is shown in FIG. 8C. In FIG. 8C, within the imaging range 223, the contour of the finger 220 is shown by a dashed line, and the contour of the contact portion 221 is shown by a one-dot chain line. Within the contact portion 221, a fingerprint 222 with high contrast can be imaged due to the difference in the amount of light incident on the light receiving element 212.

[0184] The display panel 200 can also function as a touch panel and a tablet. FIG. 8D shows a state where the tip of the stylus 225 is in contact with the substrate 202 and is being slid in the direction of the dashed arrow.

[0185] As shown in FIG. 8D, the diffused reflected light diffused at the contact surface between the tip of the stylus 225 and the substrate 202 enters the light receiving element 212 located at the portion overlapping the contact surface, so that the position of the tip of the stylus 225 can be detected with high accuracy.

[0186] FIG. 8E shows an example of the trajectory 226 of the stylus 225 detected by the display panel 200. Since the display panel 200 can detect the position of a detected object such as the stylus 225 with high positional accuracy, it is also possible to perform high-definition drawing in a drawing application or the like. Also, unlike the case of using a capacitive touch sensor, an electromagnetic induction type touch pen, etc., since the position of a highly insulating detected object can be detected, the material of the tip of the stylus 225 is not limited, and various writing utensils (for example, a pen, a glass pen, a feather pen, etc.) can also be used.

[0187] Here, FIGS. 8F to 8H show an example of a pixel applicable to the display panel 200.

[0188] The pixels shown in FIGS. 8F and 8G each have a red (R) light emitting element 211R, a green (G) light emitting element 211G, a blue (B) light emitting element 211B, and a light receiving element 212. Each pixel has a pixel circuit for driving the light emitting element 211R, the light emitting element 211G, the light emitting element 211B, and the light receiving element 212, respectively.

[0189] FIG. 8F is an example in which three light emitting elements and one light receiving element are arranged in a 2×2 matrix. FIG. 8G is an example in which three light emitting elements are arranged in a row, and a horizontally long one light receiving element 212 is arranged below them.

[0190] The pixel shown in Fig. 8H is an example having a white (W) light-emitting element 211W. Here, four light-emitting elements are arranged in a row, and a light-receiving element 212 is arranged below them.

[0191] Note that the configuration of the pixel is not limited to the above, and various arrangement methods can be adopted.

[0192] 〔Configuration Example 1-2〕 Hereinafter, an example of a configuration including a light-emitting element that exhibits visible light, a light-emitting element that exhibits infrared light, and a light-receiving element will be described.

[0193] The display panel 200A shown in Fig. 9A has a light-emitting element 211IR in addition to the configuration illustrated in Fig. 8A. The light-emitting element 211IR is a light-emitting element that emits infrared light IR. At this time, it is preferable to use, as the light-receiving element 212, an element capable of receiving at least the infrared light IR emitted by the light-emitting element 211IR. More preferably, as the light-receiving element 212, an element capable of receiving both visible light and infrared light is used.

[0194] As shown in Fig. 9A, when a finger 220 touches the substrate 202, the infrared light IR emitted from the light-emitting element 211IR is reflected by the finger 220, and a part of the reflected light is incident on the light-receiving element 212, thereby enabling acquisition of the position information of the finger 220.

[0195] Figs. 9B to 9D show an example of a pixel applicable to the display panel 200A.

[0196] Fig. 9B is an example in which three light-emitting elements are arranged in a row, and below them, the light-emitting element 211IR and the light-receiving element 212 are arranged side by side horizontally. Fig. 9C is an example in which four light-emitting elements including the light-emitting element 211IR are arranged in a row, and below them, the light-receiving element 212 is arranged.

[0197] Fig. 9D is an example in which three light-emitting elements and a light-receiving element 212 are arranged in four directions with the light-emitting element 211IR at the center.

[0198] In the pixels shown in FIGS. 9B to 9D, the light-emitting elements with each other, and the light-emitting element and the light-receiving element can exchange their respective positions.

[0199] 〔Configuration Example 1-3〕 Hereinafter, an example of a configuration including a light-emitting element that exhibits visible light and a light-emitting and light-receiving element that exhibits visible light and receives visible light will be described.

[0200] The display panel 200B shown in FIG. 10A includes a light-emitting element 211B, a light-emitting element 211G, and a light-emitting and light-receiving element 213R. The light-emitting and light-receiving element 213R has a function as a light-emitting element that emits red (R) light and a function as a photoelectric conversion element that receives visible light. FIG. 10A shows an example in which the light-emitting and light-receiving element 213R receives the green (G) light emitted by the light-emitting element 211G. Note that the light-emitting and light-receiving element 213R may receive the blue (B) light emitted by the light-emitting element 211B. Further, the light-emitting and light-receiving element 213R may receive both green light and blue light.

[0201] For example, the light-emitting and light-receiving element 213R preferably receives light having a shorter wavelength than the light emitted by itself. Alternatively, the light-emitting and light-receiving element 213R may be configured to receive light having a longer wavelength (for example, infrared light) than the light emitted by itself. The light-emitting and light-receiving element 213R may be configured to receive light having a wavelength similar to that of the light emitted by itself, but in that case, it may also receive the light emitted by itself, and there is a risk that the light-emitting efficiency will decrease. Therefore, the light-emitting and light-receiving element 213R is preferably configured so that the peak of the emission spectrum and the peak of the absorption spectrum do not overlap as much as possible.

[0202] In addition, the light emitted by the light-emitting and light-receiving element here is not limited to red light. Further, the light emitted by the light-emitting element is not limited to a combination of green light and blue light. For example, as the light-emitting and light-receiving element, an element that emits green or blue light and receives light having a wavelength different from the light emitted by itself can be used.

[0203] In this way, by having the light-emitting and light-receiving element 213R serve as both a light-emitting element and a light-receiving element, the number of elements arranged in one pixel can be reduced. Therefore, it becomes easier to achieve high definition, a high aperture ratio, high resolution, etc.

[0204] FIGS. 10B to 10I show an example of a pixel applicable to the display panel 200B.

[0205] FIG. 10B shows an example in which the light-emitting and light-receiving element 213R, the light-emitting element 211G, and the light-emitting element 211B are arranged in a row. FIG. 10C shows an example in which the light-emitting element 211G and the light-emitting element 211B are alternately arranged in the vertical direction, and the light-emitting and light-receiving element 213R is arranged beside them.

[0206] FIG. 10D shows an example in which three light-emitting elements (the light-emitting element 211G, the light-emitting element 211B, and the light-emitting element 211X) and one light-emitting and light-receiving element are arranged in a 2×2 matrix. The light-emitting element 211X is an element that exhibits light other than R, G, and B. Examples of light other than R, G, and B include light such as white (W), yellow (Y), cyan (C), magenta (M), infrared light (IR), and ultraviolet light (UV). When the light-emitting element 211X exhibits infrared light, it is preferable that the light-emitting and light-receiving element has a function of detecting infrared light or a function of detecting both visible light and infrared light. Depending on the use of the sensor, the wavelength of the light detected by the light-emitting and light-receiving element can be determined.

[0207] FIG. 10E shows two pixels. The area including three elements surrounded by a dotted line corresponds to one pixel. Each pixel has a light-emitting element 211G, a light-emitting element 211B, and a light-receiving and light-emitting element 213R. In the left pixel shown in FIG. 10E, the light-emitting element 211G is arranged in the same row as the light-receiving and light-emitting element 213R, and the light-emitting element 211B is arranged in the same column as the light-receiving and light-emitting element 213R. In the right pixel shown in FIG. 10E, the light-emitting element 211G is arranged in the same row as the light-receiving and light-emitting element 213R, and the light-emitting element 211B is arranged in the same column as the light-emitting element 211G. In the pixel layout shown in FIG. 10E, in both odd-numbered rows and even-numbered rows, the light-receiving and light-emitting element 213R, the light-emitting element 211G, and the light-emitting element 211B are repeatedly arranged, and in each column, light-emitting elements or light-receiving and light-emitting elements of different colors are arranged in odd-numbered rows and even-numbered rows.

[0208] FIG. 10F shows four pixels to which a pentile arrangement is applied, and two adjacent pixels have light-emitting elements or light-receiving and light-emitting elements that exhibit two different colors of light in combination. Note that FIG. 10F shows the upper surface shape of the light-emitting element or the light-receiving and light-emitting element.

[0209] The upper-left pixel and the lower-right pixel shown in FIG. 10F have the light-receiving and light-emitting element 213R and the light-emitting element 211G. Also, the upper-right pixel and the lower-left pixel have the light-emitting element 211G and the light-emitting element 211B. That is, in the example shown in FIG. 10F, each pixel is provided with the light-emitting element 211G.

[0210] The upper surface shape of the light-emitting element and the light-receiving and light-emitting element is not particularly limited, and can be a circle, an ellipse, a polygon, a rounded polygon, or the like. FIGS. 10F and the like show an example in which the upper surface shape of the light-emitting element and the light-receiving and light-emitting element is a square (rhombus) inclined at approximately 45 degrees. Note that 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 in part or all of the colors.

[0211] Also, the sizes of the light-emitting regions (or light-receiving and light-emitting regions) 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. For example, in FIG. 10F, the area of the light-emitting region of the light-emitting element 211G provided in each pixel may be made smaller than the light-emitting regions (or light-receiving and light-emitting regions) of other elements.

[0212] FIG. 10G is a modified example of the pixel arrangement shown in FIG. 10F. Specifically, the configuration of FIG. 10G is obtained by rotating the configuration of FIG. 10F by 45 degrees. In FIG. 10F, the description was made assuming that one pixel has two elements, but as shown in FIG. 10G, it can also be considered that one pixel is constituted by four elements.

[0213] FIG. 10H is a modified example of the pixel arrangement shown in FIG. 10F. The upper left pixel and the lower right pixel shown in FIG. 10H have the light-receiving and light-emitting element 213R and the light-emitting element 211G. Also, the upper right pixel and the lower left pixel have the light-receiving and light-emitting element 213R and the light-emitting element 211B. That is, in the example shown in FIG. 10H, the light-receiving and light-emitting element 213R is provided in each pixel. Since the light-receiving and light-emitting element 213R is provided in each pixel, the configuration shown in FIG. 10H can perform imaging with higher resolution than the configuration shown in FIG. 10F. Thereby, for example, the accuracy of biometric authentication can be improved.

[0214] FIG. 10I is a modified example of the pixel arrangement shown in FIG. 10H, and is a configuration obtained by rotating the pixel arrangement by 45 degrees.

[0215] In FIG. 10I, the description will be made assuming that one pixel is constituted by four elements (two light-emitting elements and two light-receiving and light-emitting elements). In this way, by having a plurality of light-receiving and light-emitting elements having a light-receiving function in one pixel, imaging can be performed with high resolution. Therefore, the accuracy of biometric authentication can be improved. For example, the imaging resolution can be made √2 times the display resolution.

[0216] The display device to which the configuration shown in FIG. 10H or FIG. 10I 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-receiving and light-emitting 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-receiving and light-emitting element emits red light and has a light-receiving function.

[0217] For example, when detecting a touch operation using the light-receiving and light-emitting 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-receiving and light-emitting element has a function of receiving blue light. Note that the present invention is not limited to this, and the light-emitting element serving as the light source can be appropriately selected according to the sensitivity of the light-receiving and light-emitting element.

[0218] As described above, various arrays of pixels can be applied to the display device of the present embodiment.

[0219] [Device Structure] Next, the detailed configurations of the light-emitting element, the light-receiving element, and the light-receiving and light-emitting element that can be used in the display device according to one aspect of the present invention will be described.

[0220] The display device according to one aspect of the present invention may be 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 toward the substrate side on which the light-emitting element is formed, or a dual emission type that emits light on both sides.

[0221] In the present embodiment, a top emission type display device will be described as an example.

[0222] In this specification and the like, unless otherwise specified, even when describing a configuration having a plurality of elements (such as a light-emitting element and a light-emitting layer), when describing matters common to each element, the alphabet is omitted. For example, when describing matters common to the light-emitting layer 283R and the light-emitting layer 283G, etc., it may be described as the light-emitting layer 283.

[0223] The display device 280A shown in FIG. 11A includes a light-receiving element 270PD, a light-emitting element 270R that emits red (R) light, a light-emitting element 270G that emits green (G) light, and a light-emitting element 270B that emits blue (B) light.

[0224] Each light-emitting element includes a pixel electrode 271, a hole injection layer 281, a hole transport layer 282, a light-emitting layer, an electron transport layer 284, an electron injection layer 285, and a common electrode 275 laminated in this order. The light-emitting element 270R includes a light-emitting layer 283R, the light-emitting element 270G includes a light-emitting layer 283G, and the light-emitting element 270B includes a light-emitting layer 283B. The light-emitting layer 283R includes a light-emitting substance that emits red light, the light-emitting layer 283G includes a light-emitting substance that emits green light, and the light-emitting layer 283B includes a light-emitting substance that emits blue light.

[0225] The light-emitting element is an electroluminescent element that emits light toward the common electrode 275 side by applying a voltage between the pixel electrode 271 and the common electrode 275.

[0226] The light-receiving element 270PD includes a pixel electrode 271, a hole injection layer 281, a hole transport layer 282, an active layer 273, an electron transport layer 284, an electron injection layer 285, and a common electrode 275 laminated in this order.

[0227] The light-receiving element 270PD is a photoelectric conversion element that receives light incident from outside the display device 280A and converts it into an electrical signal.

[0228] In this embodiment, it will be described that in both the light-emitting element and the light-receiving element, the pixel electrode 271 functions as an anode and the common electrode 275 functions as a cathode. That is, the light-receiving element can detect the light incident on the light-receiving element, generate charges, and extract them as current by applying a reverse bias between the pixel electrode 271 and the common electrode 275 and driving it.

[0229] In the display device of this embodiment, an organic compound is used for the active layer 273 of the light-receiving element 270PD. The light-receiving element 270PD can have the same configuration as the light-emitting element for the layers other than the active layer 273. Therefore, the light-receiving element 270PD can be formed in parallel with the formation of the light-emitting element only by adding a step of forming the active layer 273 to the manufacturing process of the light-emitting element. Further, the light-emitting element and the light-receiving element 270PD can be formed on the same substrate. Therefore, the light-receiving element 270PD can be incorporated into the display device without significantly increasing the manufacturing process.

[0230] In the display device 280A, an example is shown in which the light-receiving element 270PD and the light-emitting element have the same configuration except that the active layer 273 of the light-receiving element 270PD and the light-emitting layer 283 of the light-emitting element are made separately. However, the configurations of the light-receiving element 270PD and the light-emitting element are not limited to this. The light-receiving element 270PD and the light-emitting element may have layers made separately from each other in addition to the active layer 273 and the light-emitting layer 283. It is preferable that the light-receiving element 270PD and the light-emitting element have one or more layers (common layers) that are commonly used. Thereby, the light-receiving element 270PD can be incorporated into the display device without significantly increasing the manufacturing process.

[0231] For the electrode on the side from which light is extracted among the pixel electrode 271 and the common electrode 275, a conductive film that transmits visible light is used. Further, it is preferable to use a conductive film that reflects visible light for the electrode on the side from which light is not extracted.

[0232] It is preferable that a microcavity structure is applied to the light-emitting element included in the display device according to the present embodiment. Therefore, it is preferable that one of the pair of electrodes included in the light-emitting element has an electrode (semi-transmissive / semi-reflective electrode) having transmissivity and reflectivity with respect to visible light, and the other preferably has an electrode (reflective electrode) having reflectivity with respect to visible light. By having a microcavity structure in the light-emitting element, the light emitted from the light-emitting layer can be resonated between both electrodes, and the light emitted from the light-emitting element can be enhanced.

[0233] Note that the semi-transmissive / semi-reflective electrode can have a laminated structure of a reflective electrode and an electrode having transmissivity with respect to visible light (also referred to as a transparent electrode).

[0234] The light transmittance of the transparent electrode is set to 40% or more. For example, it is preferable to use an electrode having a transmittance of 40% or more for visible light (light having a wavelength of 400 nm or more and less than 750 nm) in the light-emitting element. The reflectivity of visible light of the semi-transmissive / semi-reflective electrode is set to 10% or more and 95% or less, preferably 30% or more and 80% or less. The reflectivity of visible light of the reflective electrode is set to 40% or more and 100% or less, preferably 70% or more and 100% or less. In addition, the resistivity of these electrodes is preferably 1×10 -2 Ωcm or less. When the light-emitting element emits near-infrared light (light having a wavelength of 750 nm or more and 1300 nm or less), it is preferable that the transmittance or reflectivity of near-infrared light of these electrodes satisfies the above numerical range as well as the transmittance or reflectivity of visible light.

[0235] The light-emitting element has at least a light-emitting layer 283. As layers other than the light-emitting layer 283, the light-emitting element may further have a layer containing a substance with high hole injection properties, a substance with high hole transport properties, a hole blocking material, a substance with high electron transport properties, a substance with high electron injection properties, an electron blocking material, or a bipolar substance (a substance with high electron transport properties and high hole transport properties).

[0236] For example, the light-emitting element and the light-receiving element can share one or more of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. Further, the light-emitting element and the light-receiving element can separately form one or more of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer.

[0237] The hole injection layer is a layer that injects holes from the anode into the hole transport layer, and is a layer containing a material with high hole injection properties. As a 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 can be used.

[0238] In the light-emitting element, the hole transport layer is a layer that transports the holes injected from the anode by the hole injection layer to the light-emitting layer. In the light-receiving element, the hole transport layer is a layer that transports the holes generated based on the light incident on the active layer to the anode. The hole transport layer is a layer containing a hole transport material. As the hole transport material, a substance having a hole mobility of 1×10 -6 cm 2 / Vs or more is preferable. In addition, as long as it is a substance with higher hole transportability than electrons, other substances can also be used. As the hole transport material, a hole transport material with high hole transportability such as a π-electron excess type heteroaromatic compound (for example, a carbazole derivative, a thiophene derivative, a furan derivative, etc.), an aromatic amine (a compound having an aromatic amine skeleton), etc. is preferable.

[0239] In the light-emitting element, the electron transport layer is a layer that transports the electrons injected from the cathode by the electron injection layer to the light-emitting layer. In the light-receiving element, the electron transport layer is a layer that transports the electrons generated based on the light incident on the active layer to the cathode. The electron transport layer is a layer containing an electron transport material. As the electron transport material, a substance having a hole mobility of 1×10 -6 cm 2A substance having an electron mobility of / Vs or more is preferable. In addition, any other substances can be used as long as they are substances with higher electron transportability than holes. As the electron transport material, in addition to metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, etc., oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other electron transport materials such as π-electron deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds can be used.

[0240] The electron injection layer is a layer that injects electrons from the cathode into the electron transport layer and is a layer containing a material with high electron injection properties. As the material with high electron injection properties, an alkali metal, an alkaline earth metal, or a compound thereof can be used. As the material with high electron injection properties, a composite material containing an electron transport material and a donor material (electron donating material) can also be used.

[0241] The light-emitting layer 283 is a layer containing a light-emitting substance. The light-emitting layer 283 can have one or more kinds of light-emitting substances. As the light-emitting substance, substances exhibiting light-emitting colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red can be appropriately used. In addition, a substance that emits near-infrared light can also be used as the light-emitting substance.

[0242] Examples of the light-emitting substance include a fluorescent material, a phosphorescent material, a TADF material, and a quantum dot material.

[0243] 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.

[0244] 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.

[0245] In addition to the luminescent substance (guest material), the light-emitting layer 283 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.

[0246] The light-emitting layer 283 preferably has, for example, a phosphorescent material and a hole-transporting material and an electron-transporting material that 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 an exciplex to a luminescent substance (phosphorescent material), can be obtained. By selecting a combination that forms an exciplex that exhibits light emission overlapping the wavelength of the absorption band on the lowest energy side of the luminescent substance, 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 realized simultaneously.

[0247] 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 a value 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 a value 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.

[0248] The formation of an exciplex can be confirmed, for example, by comparing the emission spectra of a hole-transporting material, the emission spectra of an electron-transporting material, and the emission spectra of 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 the exciplex can be confirmed by observing differences in transient responses such as that the transient PL lifetime of the mixed film has a longer lifetime component or the ratio of the delayed component is increased compared to the transient PL lifetimes of the respective materials. Also, the above-mentioned transient PL may be read as transient electroluminescence (EL). That is, 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 are compared, and the formation of the exciplex can also be confirmed by observing differences in transient responses.

[0249] The active layer 273 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 273 is shown. By using an organic semiconductor, the light-emitting layer 283 and the active layer 273 can be formed by the same method (for example, vacuum deposition method), and it is preferable because the manufacturing apparatus can be shared.

[0250] Examples of the material of the n-type semiconductor included in the active layer 273 include fullerenes (for example, C 60 , C 70Examples thereof include electron-accepting organic semiconductor materials such as fullerenes, fullerene derivatives, etc. Fullerenes have a soccer ball-like shape, and this shape is energetically stable. Fullerenes have both deep (low) HOMO levels and LUMO levels. Since fullerenes have deep LUMO levels, they have extremely high electron-accepting (acceptor) properties. Usually, like benzene, when π-electron conjugation (resonance) spreads in a plane, the electron-donating (donor) property increases. However, since fullerenes have a spherical shape, 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.

[0251] In addition, examples of the n-type semiconductor material include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, naphthalene derivatives, anthracene derivatives, coumarin derivatives, rhodamine derivatives, triazine derivatives, quinone derivatives, etc.

[0252] Examples of the p-type semiconductor material included in the active layer 273 include electron-donating organic semiconductor materials such as copper(II) phthalocyanine (Copper(II) phthalocyanine; CuPc), tetraphenyldibenzoperiflanthene (Tetraphenyldibenzoperiflanthene; DBP), zinc phthalocyanine (Zinc Phthalocyanine; ZnPc), tin phthalocyanine (SnPc), quinacridone, etc.

[0253] Examples of the p-type semiconductor material include carbazole derivatives, thiophene derivatives, furan derivatives, compounds having an aromatic amine skeleton, and the like. Further examples of the p-type semiconductor material include naphthalene derivatives, anthracene derivatives, pyrene derivatives, triphenylene derivatives, fluorene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, indole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, indolocarbazole derivatives, porphyrin derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, quinacridone derivatives, polyphenylene vinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, polythiophene derivatives, and the like.

[0254] 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.

[0255] As the electron-accepting organic semiconductor material, it is preferable to use spherical fullerenes, and as the electron-donating organic semiconductor material, it is preferable to use an organic semiconductor material having a shape close to planar. Molecules with similar shapes tend to aggregate easily. When the same type of molecules aggregate, the energy levels of the molecular orbitals are close, so that the carrier transport property can be enhanced.

[0256] For example, the active layer 273 is preferably formed by co-evaporating an n-type semiconductor and a p-type semiconductor. Alternatively, the active layer 273 may be formed by laminating an n-type semiconductor and a p-type semiconductor.

[0257] Either low molecular weight compounds or high molecular weight compounds can be used for the light-emitting element and the light-receiving element, and they may contain inorganic compounds. The layers constituting the light-emitting element and the light-receiving element can be formed by methods such as vapor deposition method (including vacuum vapor deposition method), transfer method, printing method, inkjet method, coating method, and the like.

[0258] The display device 280B shown in FIG. 11B is different from the display device 280A in that the light receiving element 270PD and the light emitting element 270R have the same configuration.

[0259] The light receiving element 270PD and the light emitting element 270R commonly have the active layer 273 and the light emitting layer 283R.

[0260] Here, it is preferable that the light receiving element 270PD has the same configuration as a light emitting element that emits light with a longer wavelength than the light to be detected. For example, the light receiving element 270PD configured to detect blue light can have the same configuration as one or both of the light emitting element 270R and the light emitting element 270G. For example, the light receiving element 270PD configured to detect green light can have the same configuration as the light emitting element 270R.

[0261] By making the light receiving element 270PD and the light emitting element 270R have the same configuration, the number of film forming steps and the number of masks can be reduced as compared with a configuration in which the light receiving element 270PD and the light emitting element 270R have layers that are separately formed from each other. Therefore, the manufacturing process and manufacturing cost of the display device can be reduced.

[0262] Further, by making the light receiving element 270PD and the light emitting element 270R have the same configuration, the margin for misalignment can be narrowed as compared with a configuration in which the light receiving element 270PD and the light emitting element 270R have layers that are separately formed from each other. As a result, the aperture ratio of the pixel can be increased, and the light extraction efficiency of the display device can be increased. Thereby, the lifespan of the light emitting element can be extended. In addition, the display device can exhibit high brightness. Also, high definition of the display device is possible.

[0263] The light-emitting layer 283R has a light-emitting material that emits red light. The active layer 273 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). The active layer 273 preferably has an organic compound that is less likely to absorb red light and absorbs light with a shorter wavelength than red light. Thereby, red light is efficiently extracted from the light-emitting element 270R, and the light-receiving element 270PD can detect light with a shorter wavelength than red light with high accuracy.

[0264] In addition, in the display device 280B, an example in which the light-emitting element 270R and the light-receiving element 270PD have the same configuration is shown, but the light-emitting element 270R and the light-receiving element 270PD may each have an optical adjustment layer with a different thickness.

[0265] The display device 280C shown in FIGS. 12A and 12B has a light-emitting and light-receiving element 270SR that emits red (R) light and has a light-receiving function, a light-emitting element 270G, and a light-emitting element 270B. The configurations of the light-emitting element 270G and the light-emitting element 270B can be applied to the above-described display device 280A and the like.

[0266] The light-emitting and light-receiving element 270SR has a pixel electrode 271, a hole injection layer 281, a hole transport layer 282, an active layer 273, a light-emitting layer 283R, an electron transport layer 284, an electron injection layer 285, and a common electrode 275 laminated in this order. The light-emitting and light-receiving element 270SR has the same configuration as the light-emitting element 270R and the light-receiving element 270PD exemplified in the above-described display device 280B.

[0267] In FIG. 12A, a case where the light-emitting and light-receiving element 270SR functions as a light-emitting element is shown. FIG. 12A shows an example in which the light-emitting element 270B emits blue light, the light-emitting element 270G emits green light, and the light-emitting and light-receiving element 270SR emits red light.

[0268] In FIG. 12B, a case where the light-emitting and light-receiving element 270SR functions as a light-receiving element is shown. FIG. 12B shows an example in which the light-emitting and light-receiving element 270SR receives blue light emitted by the light-emitting element 270B and green light emitted by the light-emitting element 270G.

[0269] The light-emitting elements 270B, 270G, and the light-receiving and light-emitting element 270SR each have a pixel electrode 271 and a common electrode 275. In the present embodiment, a case where the pixel electrode 271 functions as an anode and the common electrode 275 functions as a cathode will be described as an example. The light-receiving and light-emitting element 270SR can detect light incident on the light-receiving and light-emitting element 270SR, generate charges, and extract them as a current by driving with a reverse bias applied between the pixel electrode 271 and the common electrode 275.

[0270] The light-receiving and light-emitting element 270SR can be said to have a configuration in which an active layer 273 is added to the light-emitting element. That is, by simply adding a step of forming the active layer 273 to the manufacturing process of the light-emitting element, the light-receiving and light-emitting element 270SR can be formed in parallel with the formation of the light-emitting element. Further, the light-emitting element and the light-receiving and light-emitting 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.

[0271] The lamination order of the light-emitting layer 283R and the active layer 273 is not limited. FIGS. 12A and 12B show an example in which the active layer 273 is provided on the hole transport layer 282 and the light-emitting layer 283R is provided on the active layer 273. The lamination order of the light-emitting layer 283R and the active layer 273 may be reversed.

[0272] Further, the light-receiving and light-emitting element may not have at least one of a hole injection layer 281, a hole transport layer 282, an electron transport layer 284, and an electron injection layer 285. Further, the light-receiving and light-emitting element may have other functional layers such as a hole blocking layer and an electron blocking layer.

[0273] In the light-receiving and light-emitting 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.

[0274] Since the functions and materials of the respective layers constituting the light-receiving and light-emitting element are the same as those of the respective layers constituting the light-emitting element and the light-receiving element, detailed description thereof will be omitted.

[0275] Figures 12C to 12G show examples of the stacked structure of the light-emitting and light-receiving element.

[0276] The light-emitting and light-receiving element shown in FIG. 12C has a first electrode 277, a hole injection layer 281, a hole transport layer 282, a light-emitting layer 283R, an active layer 273, an electron transport layer 284, an electron injection layer 285, and a second electrode 278.

[0277] FIG. 12C is an example in which the light-emitting layer 283R is provided on the hole transport layer 282 and the active layer 273 is stacked on the light-emitting layer 283R.

[0278] As shown in FIGS. 12A to 12C, the active layer 273 and the light-emitting layer 283R may be in contact with each other.

[0279] Also, it is preferable to provide a buffer layer between the active layer 273 and the light-emitting layer 283R. At this time, the buffer layer preferably has hole-transporting properties and electron-transporting properties. For example, it is preferable to use a bipolar substance for the buffer layer. Alternatively, at least one layer among a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole blocking layer, and an electron blocking layer can be used as the buffer layer. FIG. 12D shows an example in which the hole transport layer 282 is used as the buffer layer.

[0280] By providing a buffer layer between the active layer 273 and the light-emitting layer 283R, it is possible to suppress the transfer of excitation energy from the light-emitting layer 283R to the active layer 273. Also, the optical path length (cavity length) of the microcavity structure can be adjusted using the buffer layer. Therefore, a high luminous efficiency can be obtained from the light-emitting and light-receiving element having a buffer layer between the active layer 273 and the light-emitting layer 283R.

[0281] FIG. 12E shows an example having a stacked structure in which a hole transport layer 282-1, an active layer 273, a hole transport layer 282-2, and a light-emitting layer 283R are stacked in this order on a hole injection layer 281. The hole transport layer 282-2 functions as a buffer layer. The hole transport layer 282-1 and the hole transport layer 282-2 may contain the same material or different materials. Further, instead of the hole transport layer 282-2, a layer that can be used for the buffer layer described above may be used. Also, the positions of the active layer 273 and the light-emitting layer 283R may be interchanged.

[0282] The light-receiving and light-emitting device shown in FIG. 12F is different from the light-receiving and light-emitting device shown in FIG. 12A in that it does not have a hole transport layer 282. Thus, the light-receiving and light-emitting device may not have at least one of a hole injection layer 281, a hole transport layer 282, an electron transport layer 284, and an electron injection layer 285. Also, the light-receiving and light-emitting device may have other functional layers such as a hole blocking layer and an electron blocking layer.

[0283] The light-receiving and light-emitting device shown in FIG. 12G is different from the light-receiving and light-emitting device shown in FIG. 12A in that it does not have an active layer 273 and a light-emitting layer 283R, but has a layer 289 that serves as both a light-emitting layer and an active layer.

[0284] As the layer that serves as both a light-emitting layer and an active layer, for example, a layer containing three materials, namely, an n-type semiconductor that can be used for the active layer 273, a p-type semiconductor that can be used for the active layer 273, and a light-emitting substance that can be used for the light-emitting layer 283R, can be used.

[0285] Note that it is preferable that the absorption band on the lowest energy side of the absorption spectrum of the mixed material of the n-type semiconductor and the p-type semiconductor does not overlap with the maximum peak of the emission spectrum (PL spectrum) of the light-emitting substance, and it is more preferable that they are sufficiently separated.

[0286] [Configuration Example 2 of Display Device] Hereinafter, a detailed configuration of a display device according to an aspect of the present invention will be described. Here, in particular, an example of a display device having a light-receiving element and a light-emitting element will be described.

[0287] 〔Configuration Example 2-1〕 FIG. 13A shows a cross-sectional view of a display device 300A. The display device 300A includes a substrate 351, a substrate 352, a light-receiving element 310, and a light-emitting element 390.

[0288] The light-emitting element 390 includes a pixel electrode 391, a buffer layer 312, a light-emitting layer 393, a buffer layer 314, and a common electrode 315 stacked in this order. The buffer layer 312 can include one or both of a hole injection layer and a hole transport layer. The light-emitting layer 393 includes an organic compound. The buffer layer 314 can include one or both of an electron injection layer and an electron transport layer. The light-emitting element 390 has a function of emitting visible light 321. Note that the display device 300A may further include a light-emitting element having a function of emitting infrared light.

[0289] The light-receiving element 310 includes a pixel electrode 311, a buffer layer 312, an active layer 313, a buffer layer 314, and a common electrode 315 stacked in this order. The active layer 313 includes an organic compound. The light-receiving element 310 has a function of detecting visible light. Note that the light-receiving element 310 may further have a function of detecting infrared light.

[0290] The buffer layer 312, the buffer layer 314, and the common electrode 315 are layers common to the light-emitting element 390 and the light-receiving element 310 and are provided across these elements. The buffer layer 312, the buffer layer 314, and the common electrode 315 have a portion overlapping with the active layer 313 and the pixel electrode 311, a portion overlapping with the light-emitting layer 393 and the pixel electrode 391, and a portion not overlapping with either of them.

[0291] In the present embodiment, it is described that in both the light-emitting element 390 and the light-receiving element 310, the pixel electrode functions as an anode and the common electrode 315 functions as a cathode. That is, by driving the light-receiving element 310 with a reverse bias applied between the pixel electrode 311 and the common electrode 315, the display device 300A can detect light incident on the light-receiving element 310, generate charges, and extract them as a current.

[0292] The pixel electrode 311, the pixel electrode 391, the buffer layer 312, the active layer 313, the buffer layer 314, the light-emitting layer 393, and the common electrode 315 may each have a single-layer structure or a laminated structure.

[0293] The pixel electrode 311 and the pixel electrode 391 are each located on the insulating layer 414. Each pixel electrode can be formed of the same material and in the same process. The ends of the pixel electrode 311 and the pixel electrode 391 are covered by the partition wall 416. Two adjacent pixel electrodes are electrically insulated from each other (also referred to as electrically separated) by the partition wall 416.

[0294] As the partition wall 416, 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 416 is a layer that transmits visible light. Instead of the partition wall 416, a partition wall that blocks visible light may be provided.

[0295] The common electrode 315 is a layer that is commonly used for the light-receiving element 310 and the light-emitting element 390.

[0296] The materials, film thicknesses, etc. of the pair of electrodes of the light-receiving element 310 and the light-emitting element 390 can be made equal. Thereby, the manufacturing cost of the display device can be reduced and the manufacturing process can be simplified.

[0297] The display device 300A includes a light-receiving element 310, a light-emitting element 390, a transistor 331, a transistor 332, etc. between a pair of substrates (substrate 351 and substrate 352).

[0298] In the light-receiving element 310, the buffer layer 312, the active layer 313, and the buffer layer 314 located between the pixel electrode 311 and the common electrode 315 can also be referred to as organic layers (layers containing organic compounds). The pixel electrode 311 preferably has a function of reflecting visible light. The common electrode 315 has a function of transmitting visible light. In the case where the light-receiving element 310 is configured to detect infrared light, the common electrode 315 has a function of transmitting infrared light. Further, the pixel electrode 311 preferably has a function of reflecting infrared light.

[0299] The light-receiving element 310 has a function of detecting light. Specifically, the light-receiving element 310 is a photoelectric conversion element that receives the light 322 incident from the outside of the display device 300A and converts it into an electrical signal. The light 322 can also be the light reflected by the object from the light emitted by the light-emitting element 390. Also, the light 322 may enter the light-receiving element 310 through a lens or the like provided in the display device 300A.

[0300] In the light-emitting element 390, the buffer layer 312, the light-emitting layer 393, and the buffer layer 314 located between the pixel electrode 391 and the common electrode 315 can also be collectively referred to as an EL layer. Note that the EL layer has at least the light-emitting layer 393. As described above, the pixel electrode 391 preferably has a function of reflecting visible light. Also, the common electrode 315 has a function of transmitting visible light. In the case where the display device 300A has a light-emitting element that emits infrared light, the common electrode 315 has a function of transmitting infrared light. Further, the pixel electrode 391 preferably has a function of reflecting infrared light.

[0301] It is preferable that a microcavity structure is applied to the light-emitting element included in the display device of the present embodiment. The light-emitting element 390 may have an optical adjustment layer between the pixel electrode 391 and the common electrode 315. By applying the microresonator structure, light of a specific color can be extracted from each light-emitting element while being enhanced.

[0302] The light-emitting element 390 has a function of emitting visible light. Specifically, the light-emitting element 390 is an electroluminescent element that emits light (here, visible light 321) toward the substrate 352 side by applying a voltage between the pixel electrode 391 and the common electrode 315.

[0303] The pixel electrode 311 of the light-receiving element 310 is electrically connected to the source or drain of the transistor 331 through an opening provided in the insulating layer 414. The pixel electrode 391 of the light-emitting element 390 is electrically connected to the source or drain of the transistor 332 through an opening provided in the insulating layer 414.

[0304] The transistor 331 and the transistor 332 are in contact with each other on the same layer (substrate 351 in FIG. 13A).

[0305] At least a part of the circuit electrically connected to the light-receiving element 310 is preferably formed of the same material and in the same process as the circuit electrically connected to the light-emitting element 390. 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.

[0306] The light-receiving element 310 and the light-emitting element 390 are each preferably covered with a protective layer 395. In FIG. 13A, the protective layer 395 is provided in contact with the common electrode 315. By providing the protective layer 395, it is possible to suppress impurities such as water from entering the light-receiving element 310 and the light-emitting element 390, and to improve the reliability of the light-receiving element 310 and the light-emitting element 390. Further, the protective layer 395 and the substrate 352 are bonded together by an adhesive layer 342.

[0307] A light-shielding layer 358 is provided on the surface of the substrate 352 on the side of the substrate 351. The light-shielding layer 358 has openings at positions overlapping the light-emitting element 390 and at positions overlapping the light-receiving element 310.

[0308] Here, the light receiving element 310 detects the light reflected by the object from the light emission of the light emitting element 390. However, the light emitted from the light emitting element 390 may be reflected within the display device 300A and enter the light receiving element 310 without passing through the object. The light shielding layer 358 can suppress the influence of such stray light. For example, when the light shielding layer 358 is not provided, the light 323 emitted from the light emitting element 390 may be reflected by the substrate 352, and the reflected light 324 may enter the light receiving element 310. By providing the light shielding layer 358, it is possible to suppress the reflected light 324 from entering the light receiving element 310. Thereby, noise can be reduced and the sensitivity of the sensor using the light receiving element 310 can be enhanced.

[0309] As the light shielding layer 358, a material that blocks the light emission from the light emitting element can be used. The light shielding layer 358 preferably absorbs visible light. As the light shielding layer 358, 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 358 may have a laminated structure of a red color filter, a green color filter, and a blue color filter.

[0310] 〔Configuration Example 2-2〕 The display device 300B shown in FIG. 13B is mainly different from the above display device 300A in that it has a lens 349.

[0311] The lens 349 is provided on the substrate 351 side of the substrate 352. The light 322 incident from the outside enters the light receiving element 310 through the lens 349. It is preferable to use a material with high transparency to visible light for the lens 349 and the substrate 352.

[0312] By allowing light to enter the light receiving element 310 through the lens 349, the range of light incident on the light receiving element 310 can be narrowed. Thereby, it is possible to suppress the imaging ranges from overlapping among the plurality of light receiving elements 310, and a clear image with less blurring can be captured.

[0313] In addition, the lens 349 can condense the incident light. Therefore, the amount of light incident on the light receiving element 310 can be increased. Thereby, the photoelectric conversion efficiency of the light receiving element 310 can be enhanced.

[0314] 〔Configuration Example 2-3〕 The display device 300C shown in FIG. 13C mainly differs from the above-described display device 300A in that the shape of the light shielding layer 358 is different.

[0315] The light shielding layer 358 is provided such that, in a plan view, the opening overlapping the light receiving element 310 is located inside the light receiving region of the light receiving element 310. The smaller the diameter of the opening of the light shielding layer 358 overlapping the light receiving element 310, the narrower the range of light incident on the light receiving element 310 can be made. Thereby, it is possible to suppress the imaging ranges from overlapping between the plurality of light receiving elements 310, and a clear image with less blurring can be captured.

[0316] For example, the area of the opening of the light shielding layer 358 can be 80% or less, 70% or less, 60% or less, 50% or less, or 40% or less of the area of the light receiving region of the light receiving element 310, and 1% or more, 5% or more, or 10% or more. The smaller the area of the opening of the light shielding layer 358, the clearer the image that can be captured. On the other hand, if the area of the opening is too small, the amount of light reaching the light receiving element 310 may decrease, and the light receiving sensitivity may decrease. Therefore, it is preferably set appropriately within the above-described range. Note that the above-described upper limit value and lower limit value can be arbitrarily combined. In addition, the light receiving region of the light receiving element 310 can be rephrased as the opening of the partition wall 416.

[0317] Note that the center of the opening of the light shielding layer 358 overlapping the light receiving element 310 may be deviated from the center of the light receiving region of the light receiving element 310 in a plan view. Furthermore, in a plan view, the opening of the light shielding layer 358 may be configured not to overlap the light receiving region of the light receiving element 310. Thereby, only the obliquely incident light transmitted through the opening of the light shielding layer 358 can be received by the light receiving element 310. Thereby, the range of light incident on the light receiving element 310 can be more effectively limited, and a clear image can be captured.

[0318] 〔Constitution Example 2-4〕 The display device 300D shown in FIG. 14A is mainly different from the display device 300A in that the buffer layer 312 is not a common layer.

[0319] The light-receiving element 310 includes a pixel electrode 311, a buffer layer 312, an active layer 313, a buffer layer 314, and a common electrode 315. The light-emitting element 390 includes a pixel electrode 391, a buffer layer 392, a light-emitting layer 393, a buffer layer 314, and a common electrode 315. The active layer 313, the buffer layer 312, the light-emitting layer 393, and the buffer layer 392 each have an island-shaped upper surface.

[0320] The buffer layer 312 and the buffer layer 392 may contain different materials or the same materials.

[0321] In this way, by separately forming the buffer layers for the light-emitting element 390 and the light-receiving element 310, the degree of freedom in selecting the materials for the buffer layers used in the light-emitting element 390 and the light-receiving element 310 is increased, making optimization easier. Also, by making the buffer layer 314 and the common electrode 315 common layers, the manufacturing process is simplified compared to the case where the light-emitting element 390 and the light-receiving element 310 are manufactured separately, and the manufacturing cost can be reduced.

[0322] 〔Constitution Example 2-5〕 The display device 300E shown in FIG. 14B is mainly different from the display device 300A in that the buffer layer 314 is not a common layer.

[0323] The light-receiving element 310 includes a pixel electrode 311, a buffer layer 312, an active layer 313, a buffer layer 314, and a common electrode 315. The light-emitting element 390 includes a pixel electrode 391, a buffer layer 312, a light-emitting layer 393, a buffer layer 394, and a common electrode 315. The active layer 313, the buffer layer 314, the light-emitting layer 393, and the buffer layer 394 each have an island-shaped upper surface.

[0324] The buffer layer 314 and the buffer layer 394 may contain different materials or the same material.

[0325] In this way, by separately forming the buffer layers for the light-emitting element 390 and the light-receiving element 310, the degree of freedom in selecting the material for the buffer layer used in the light-emitting element 390 and the light-receiving element 310 is increased, making optimization easier. Further, by using the buffer layer 312 and the common electrode 315 as a common layer, the manufacturing process is simplified and the manufacturing cost can be reduced compared to the case where the light-emitting element 390 and the light-receiving element 310 are manufactured separately.

[0326] [Configuration Example 2-6] The display device 300F shown in FIG. 14C is mainly different from the above-described display device 300A in that the buffer layer 312 and the buffer layer 314 are not common layers.

[0327] The light-receiving element 310 includes a pixel electrode 311, a buffer layer 312, an active layer 313, a buffer layer 314, and a common electrode 315. The light-emitting element 390 includes a pixel electrode 391, a buffer layer 392, a light-emitting layer 393, a buffer layer 394, and a common electrode 315. The buffer layer 312, the active layer 313, the buffer layer 314, the buffer layer 392, the light-emitting layer 393, and the buffer layer 394 each have an island-shaped upper surface shape.

[0328] In this way, by separately forming the buffer layers for the light-emitting element 390 and the light-receiving element 310, the degree of freedom in selecting the material for the buffer layer used in the light-emitting element 390 and the light-receiving element 310 is increased, making optimization easier. Further, by using the common electrode 315 as a common layer, the manufacturing process is simplified and the manufacturing cost can be reduced compared to the case where the light-emitting element 390 and the light-receiving element 310 are manufactured separately.

[0329] [Configuration Example 3 of Display Device] Hereinafter, the detailed configuration of a display device according to an aspect of the present invention will be described. Here, in particular, an example of a display device having a light-receiving and light-emitting element and a light-emitting element will be described.

[0330] In the following, parts that overlap with the above may be incorporated by reference, and the description may be omitted in some cases.

[0331] 〔Configuration Example 3-1〕 FIG. 15A shows a cross-sectional view of the display device 300G. The display device 300G includes a light-emitting and light-receiving element 390SR, a light-emitting element 390G, and a light-emitting element 390B.

[0332] The light-emitting and light-receiving element 390SR has a function as a light-emitting element that emits red light 321R and a function as a photoelectric conversion element that receives light 322. The light-emitting element 390G can emit green light 321G. The light-emitting element 390B can emit blue light 321B.

[0333] The light-emitting and light-receiving element 390SR includes a pixel electrode 311, a buffer layer 312, an active layer 313, a light-emitting layer 393R, a buffer layer 314, and a common electrode 315. The light-emitting element 390G includes a pixel electrode 391G, a buffer layer 312, a light-emitting layer 393G, a buffer layer 314, and a common electrode 315. The light-emitting element 390B includes a pixel electrode 391B, a buffer layer 312, a light-emitting layer 393B, a buffer layer 314, and a common electrode 315.

[0334] The buffer layer 312, the buffer layer 314, and the common electrode 315 are common layers (common layers) for the light-emitting and light-receiving element 390SR, the light-emitting element 390G, and the light-emitting element 390B, and are provided across these elements. The active layer 313, the light-emitting layer 393R, the light-emitting layer 393G, and the light-emitting layer 393B each have an island-shaped top surface shape. In FIG. 15, an example is shown in which the laminate of the active layer 313 and the light-emitting layer 393R, the light-emitting layer 393G, and the light-emitting layer 393B are provided separately, but they may have regions where two adjacent ones overlap.

[0335] Similar to the display device 300D, the display device 300E, or the display device 300F, the display device 300G can be configured not to use one or both of the buffer layer 312 and the buffer layer 314 as a common layer.

[0336] The pixel electrode 311 is electrically connected to one of the source and drain of the transistor 331. The pixel electrode 391G is electrically connected to one of the source and drain of the transistor 332G. The pixel electrode 391B is electrically connected to one of the source and drain of the transistor 332B.

[0337] With such a configuration, a higher-definition display device can be realized.

[0338] [Configuration Example 3-2] The display device 300H shown in FIG. 15B is mainly different from the above display device 300G in that the configuration of the light-emitting and receiving element 390SR is different.

[0339] The light-emitting and receiving element 390SR has a light-emitting and receiving layer 318R in place of the active layer 313 and the light-emitting layer 393R.

[0340] The light-emitting and receiving layer 318R is a layer that has both the function of a light-emitting layer and the function of an active layer. For example, a layer containing the above-described light-emitting substance, an n-type semiconductor, and a p-type semiconductor can be used.

[0341] With such a configuration, the manufacturing process can be further simplified, making it easier to reduce costs.

[0342] [Configuration Example 4 of Display Device] Hereinafter, a more specific configuration of the display device according to one aspect of the present invention will be described.

[0343] FIG. 16 shows a perspective view of the display device 400, and FIG. 17A shows a cross-sectional view of the display device 400.

[0344] The display device 400 has a configuration in which a substrate 353 and a substrate 354 are bonded together. In FIG. 16, the substrate 354 is indicated by a dashed line.

[0345] The display device 400 includes a display unit 362, a circuit 364, a wiring 365, etc. FIG. 16 shows an example in which an IC (integrated circuit) 373 and an FPC 372 are mounted on the display device 400. Therefore, the configuration shown in FIG. 16 can also be referred to as a display module having the display device 400, the IC, and the FPC.

[0346] As the circuit 364, for example, a scanning line driving circuit can be used.

[0347] The wiring 365 has a function of supplying signals and power to the display unit 362 and the circuit 364. The signals and power are input to the wiring 365 from the outside via the FPC 372, or input to the wiring 365 from the IC 373.

[0348] FIG. 16 shows an example in which the IC 373 is provided on the substrate 353 by a COG (Chip On Glass) method, a COF (Chip On Film) method, or the like. As the IC 373, for example, an IC having a scanning line driving circuit or a signal line driving circuit can be applied. Note that the display device 400 and the display module may be configured without an IC. Further, the IC may be mounted on the FPC by a COF method or the like.

[0349] FIG. 17A shows an example of a cross-section when a part of the region including the FPC 372, a part of the region including the circuit 364, a part of the region including the display unit 362, and a part of the region including the end portion of the display device 400 shown in FIG. 16 are each cut.

[0350] The display device 400 shown in FIG. 17 has a transistor 408, a transistor 409, a transistor 410, a light emitting element 390, a light receiving element 310, etc. between the substrate 353 and the substrate 354.

[0351] The substrate 354 and the protective layer 395 are adhered via an adhesive layer 342, and a solid sealing structure is applied to the display device 400.

[0352] The substrate 353 and the insulating layer 412 are bonded together by an adhesive layer 355.

[0353] As a method for manufacturing the display device 400, first, a manufacturing substrate provided with an insulating layer 412, each transistor, a light receiving element 310, a light emitting element 390, etc., and a substrate 354 provided with a light shielding layer 358, etc. are bonded together by an adhesive layer 342. Then, the substrate 353 is bonded to the exposed surface of the manufacturing substrate after peeling off the manufacturing substrate, thereby transferring each component formed on the manufacturing substrate to the substrate 353. The substrate 353 and the substrate 354 are each preferably flexible. Thereby, the flexibility of the display device 400 can be enhanced.

[0354] The light emitting element 390 has a stacked structure in which a pixel electrode 391, a buffer layer 312, a light emitting layer 393, a buffer layer 314, and a common electrode 315 are stacked in this order from the insulating layer 414 side. The pixel electrode 391 is connected to one of the source and drain of the transistor 408 through an opening provided in the insulating layer 414. The transistor 408 has a function of controlling the current flowing through the light emitting element 390.

[0355] The light receiving element 310 has a stacked structure in which a pixel electrode 311, a buffer layer 312, an active layer 313, a buffer layer 314, and a common electrode 315 are stacked in this order from the insulating layer 414 side. The pixel electrode 311 is connected to one of the source and drain of the transistor 409 through an opening provided in the insulating layer 414. The transistor 409 has a function of controlling the transfer of charges accumulated in the light receiving element 310.

[0356] The light emitted by the light emitting element 390 is emitted toward the substrate 354 side. Also, light is incident on the light receiving element 310 through the substrate 354 and the adhesive layer 342. It is preferable to use a material with high transparency to visible light for the substrate 354.

[0357] The pixel electrode 311 and the pixel electrode 391 can be fabricated from the same material and in the same process. The buffer layer 312, the buffer layer 314, and the common electrode 315 are commonly used for the light-receiving element 310 and the light-emitting element 390. The light-receiving element 310 and the light-emitting element 390 can have the same configuration except that the configurations of the active layer 313 and the light-emitting layer 393 are different. Accordingly, the light-receiving element 310 can be incorporated into the display device 400 without significantly increasing the manufacturing process.

[0358] A light-shielding layer 358 is provided on the surface of the substrate 354 on the side of the substrate 353. The light-shielding layer 358 has openings at positions overlapping the light-emitting element 390 and the light-receiving element 310, respectively. By providing the light-shielding layer 358, the range in which the light-receiving element 310 detects light can be controlled. As described above, it is preferable to control the light incident on the light-receiving element 310 by adjusting the position and area of the opening of the light-shielding layer provided at the position overlapping the light-receiving element 310. Further, by providing the light-shielding layer 358, it is possible to suppress light from directly entering from the light-emitting element 390 to the light-receiving element 310 without passing through an object. Therefore, a sensor with less noise and high sensitivity can be realized.

[0359] The ends of the pixel electrode 311 and the pixel electrode 391 are covered by a partition wall 416. The pixel electrode 311 and the pixel electrode 391 contain a material that reflects visible light, and the common electrode 315 contains a material that transmits visible light.

[0360] FIG. 17A shows an example having a region where a part of the active layer 313 and a part of the light-emitting layer 393 overlap. The overlapping portion of the active layer 313 and the light-emitting layer 393 preferably overlaps the light-shielding layer 358 and the partition wall 416.

[0361] The transistor 408, the transistor 409, and the transistor 410 are all formed on the substrate 353. These transistors can be fabricated from the same material and in the same process.

[0362] On the substrate 353, an insulating layer 412, an insulating layer 411, an insulating layer 425, an insulating layer 415, an insulating layer 418, and an insulating layer 414 are provided in this order via an adhesive layer 355. A part of each of the insulating layer 411 and the insulating layer 425 functions as a gate insulating layer of each transistor. The insulating layer 415 and the insulating layer 418 are provided to cover the transistors. The insulating layer 414 is provided to cover the transistors and has a function as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0363] 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 transistors. Thereby, the insulating layer can function as a barrier layer. By adopting such a configuration, diffusion of impurities from the outside into the transistors can be effectively suppressed, and the reliability of the display device can be improved.

[0364] As the insulating layer 411, the insulating layer 412, the insulating layer 425, the insulating layer 415, and the insulating layer 418, it is preferable to use an inorganic insulating film respectively. As the inorganic insulating film, for example, a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, an aluminum nitride film, etc. 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-described insulating films may be laminated and used.

[0365] Here, the organic insulating film often has lower barrier properties than the inorganic insulating film. Therefore, it is preferable for the organic insulating film to have an opening near the end of the display device 400. In the region 428 shown in FIG. 17, an opening is formed in the insulating layer 414. Thereby, it is possible to suppress the entry of impurities from the end of the display device 400 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 400 so that the organic insulating film is not exposed at the end of the display device 400.

[0366] In the region 428 near the end of the display device 400, it is preferable that the insulating layer 418 and the protective layer 395 are in contact with each other through the opening of the insulating layer 414. In particular, it is preferable that the inorganic insulating film of the insulating layer 418 and the inorganic insulating film of the protective layer 395 are in contact with each other. Thereby, it is possible to suppress the entry of impurities from the outside into the display unit 362 through the organic insulating film. Therefore, the reliability of the display device 400 can be improved.

[0367] As the insulating layer 414 that functions as a planarization layer, an organic insulating film is suitable. Examples of materials that can be used for the organic insulating film include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimide amide resin, siloxane resin, benzocyclobutene-based resin, phenol resin, and precursors of these resins.

[0368] By providing the protective layer 395 that covers the light-emitting element 390 and the light-receiving element 310, it is possible to suppress the entry of impurities such as water into the light-emitting element 390 and the light-receiving element 310, and improve their reliability.

[0369] The protective layer 395 may be a single layer or a laminated structure. For example, the protective layer 395 may have a laminated structure of an organic insulating film and an inorganic insulating film. At this time, it is preferable that the end of the inorganic insulating film extends outside the end of the organic insulating film.

[0370] FIG. 17B shows a cross-sectional view of the transistor 401a that can be used for the transistors 408, 409, and 410.

[0371] The transistor 401a is provided on an insulating layer 412 (not shown), and has a conductive layer 421 that functions as a first gate, an insulating layer 411 that functions as a first gate insulating layer, a semiconductor layer 431, an insulating layer 425 that functions as a second gate insulating layer, and a conductive layer 423 that functions as a second gate. The insulating layer 411 is located between the conductive layer 421 and the semiconductor layer 431. The insulating layer 425 is located between the conductive layer 423 and the semiconductor layer 431.

[0372] The semiconductor layer 431 has a region 431i and a pair of regions 431n. The region 431i functions as a channel formation region. One of the pair of regions 431n functions as a source, and the other functions as a drain. The region 431n has a higher carrier concentration and higher conductivity than the region 431i. The conductive layers 422a and 422b are connected to the region 431n through openings provided in the insulating layer 418 and the insulating layer 415, respectively.

[0373] FIG. 17C shows a cross-sectional view of the transistor 401b that can be used for the transistors 408, 409, and 410. Further, FIG. 17C shows an example in which the insulating layer 415 is not provided. In the transistor 401b, the insulating layer 425 is processed in the same manner as the conductive layer 423, and the insulating layer 418 is in contact with the region 431n.

[0374] Note that the structure of the transistor included in the display device of this embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, an 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 a channel is formed.

[0375] For transistors 408, 409, and 410, a configuration is applied in which a semiconductor layer in which a channel is formed is sandwiched between two gates. The transistor may be driven by connecting the two gates and supplying the same signal to them. Alternatively, the threshold voltage of the transistor may be controlled by applying a potential for controlling the threshold voltage to one of the two gates and a potential for driving to the other.

[0376] The crystallinity of the semiconductor material used for the transistor is not particularly limited, and any of an amorphous semiconductor, a single crystal semiconductor, or a semiconductor having crystallinity (microcrystalline semiconductor, polycrystalline semiconductor, or a semiconductor having a crystal region in part) may be used. Using a semiconductor having crystallinity is preferable because deterioration of transistor characteristics can be suppressed.

[0377] 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, single crystal silicon, etc.).

[0378] The semiconductor layer preferably has, for example, indium, M (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.

[0379] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also denoted as IGZO) as the semiconductor layer.

[0380] 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 = 6:1:6 or in the vicinity thereof, In:M:Zn = 5:2:5 or in the vicinity thereof, etc. The composition in the vicinity means including the range of ±30% of the desired atomic ratio.

[0381] 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 the case 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 the case 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 the case 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.

[0382] The transistor 410 included in the circuit 364, and the transistors 408 and 409 included in the display unit 362 may have the same structure or different structures. The structures of the plurality of transistors included in the circuit 364 may all be the same or there may be two or more types. Similarly, the structures of the plurality of transistors included in the display unit 362 may all be the same or there may be two or more types.

[0383] In the area of the substrate 353 where the substrate 354 does not overlap, a connection portion 404 is provided. In the connection portion 404, the wiring 365 is electrically connected to the FPC 372 via the conductive layer 366 and the connection layer 442. On the upper surface of the connection portion 404, the conductive layer 366 obtained by processing the same conductive film as the pixel electrodes 311 and 391 is exposed. Thereby, the connection portion 404 and the FPC 372 can be electrically connected via the connection layer 442.

[0384] Various optical members can be arranged outside the substrate 354. 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 354, 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-absorbing layer, etc. may be arranged.

[0385] When a flexible material is used for the substrate 353 and the substrate 354, the flexibility of the display device can be enhanced. Further, without being limited thereto, glass, quartz, ceramic, sapphire, resin, etc. can be used for the substrate 353 and the substrate 354 respectively.

[0386] 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.

[0387] As the connection layer, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), etc. can be used.

[0388] As materials that can be used for conductive layers such as various wirings and electrodes constituting a display device, in addition to the gates, sources, and drains of transistors, metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, and alloys mainly composed of such metals can be mentioned. Films containing these materials can be used as a single layer or in a laminated structure.

[0389] Also, 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. Or, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, and alloy materials containing such metal materials can be used. Or, nitrides of the metal materials (for example, titanium nitride) may be used. When using a metal material, an alloy material (or their nitrides), it is preferably made thin enough to have translucency. Also, 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, common electrodes, etc.) of light-emitting elements and light-receiving elements (or light-emitting and receiving elements).

[0390] Examples of insulating materials that can be used for each insulating layer include resins such as acrylic resin and epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide.

[0391] This embodiment can be implemented in appropriate combination with at least some of the other embodiments described in this specification as needed.

[0392] (Embodiment 3) In this embodiment, a circuit that can be used in a display device according to an aspect of the present invention will be described.

[0393] FIG. 18A shows a block diagram of a pixel of a display device according to an aspect of the present invention.

[0394] A pixel includes an OLED, an OPD (Organic Photo Diode), a sensor circuit (denoted as Sensing Circuit), a driving transistor (denoted as Driving Transistor), and a selection transistor (denoted as Switching Transistor).

[0395] The light emitted from the OLED is reflected by an object (denoted as Object), and the reflected light is received by the OPD, thereby enabling imaging of the object. An aspect of the present invention can function as a touch sensor, an image sensor, an image scanner, or the like. An aspect of the present invention can be applied to biometric authentication by imaging fingerprints, palm prints, blood vessels (such as veins), etc. Also, it is possible to image the surface of a printed matter on which a photograph, characters, etc. are described, or an article, etc., and acquire it as image information.

[0396] The driving transistor and the selection transistor constitute a driving circuit for driving the OLED. The driving transistor has a function of controlling the current flowing through the OLED, and the OLED can emit light with a luminance corresponding to the current. The selection transistor has a function of controlling the selection and non-selection of the pixel. The magnitude of the current flowing through the driving transistor and the OLED is controlled by the value (for example, voltage value) of video data (denoted as Video Data) input from the outside via the selection transistor, and the OLED can be made to emit light with a desired emission luminance.

[0397] The sensor circuit corresponds to a drive circuit for controlling the operation of the OPD. The sensor circuit can control operations such as a reset operation for resetting the potential of the electrodes of the OPD, an exposure operation for accumulating charges in the OPD according to the amount of light irradiated, a transfer operation for transferring the charges accumulated in the OPD to a node in the sensor circuit, and a readout operation for outputting a signal (for example, a voltage or a current) corresponding to the magnitude of the charges to an external readout circuit as sensing data.

[0398] The pixel shown in Fig. 18B is mainly different from the above in that it has a memory unit (referred to as Memory) connected to the drive transistor.

[0399] Weight data is given to the memory unit. The drive transistor is given data obtained by adding video data input via a selection transistor and the weight data held in the memory unit. The weight data held in the memory unit can change the luminance of the OLED from the luminance when only video data is given. Specifically, it is possible to increase or decrease the luminance of the OLED. For example, by increasing the luminance of the OLED, it is possible to increase the light reception sensitivity of the sensor.

[0400] Fig. 18C shows an example of a pixel circuit that can be used for the above sensor circuit.

[0401] The pixel circuit PIX1 shown in Fig. 18C has a light receiving element PD, transistors M1, M2, M3, M4, and a capacitor C1. Here, an example using a photodiode as the light receiving element PD is shown.

[0402] The light-receiving element PD has its cathode electrically connected to the wiring V1 and its anode electrically connected to one of the source or drain of the transistor M1. The transistor M1 has its gate electrically connected to the wiring TX, and the other of the source or drain is electrically connected to one electrode of the capacitor C1, one of the source or drain of the transistor M2, and the gate of the transistor M3. The transistor M2 has its gate electrically connected to the wiring RES, and the other of the source or drain is electrically connected to the wiring V2. The transistor M3 has one of the source or drain electrically connected to the wiring V3, and the other of the source or drain is electrically connected to one of the source or drain of the transistor M4. The transistor M4 has its gate electrically connected to the wiring SE, and the other of the source or drain is electrically connected to the wiring OUT1.

[0403] A fixed potential is supplied to each of the wirings V1, V2, and V3. When driving the light-receiving element PD in reverse bias, a potential lower than the potential of the wiring V1 is supplied to the wiring V2. The transistor M2 is controlled by a signal supplied to the wiring RES and has a function of resetting the potential of the node connected to the gate of the transistor M3 to the potential supplied to the wiring V2. The transistor M1 is controlled by a signal supplied to the wiring TX and has a function of controlling the timing for transferring the charge accumulated in the light-receiving element PD to the above node. The transistor M3 functions as an amplification transistor that outputs an output according to the potential of the above node. The transistor M4 is controlled by a signal supplied to the wiring SE and functions as a selection transistor for reading out an output according to the potential of the above node to an external circuit connected to the wiring OUT1.

[0404] Here, the light-receiving element PD corresponds to the above OPD. Also, the potential or current output from the wiring OUT1 corresponds to the above sensing data.

[0405] FIG. 18D shows an example of a pixel circuit for driving the above OLED.

[0406] The pixel circuit PIX2 shown in FIG. 18D includes a light-emitting element EL, a transistor M5, a transistor M6, a transistor M7, and a capacitor C2. Here, an example using a light-emitting diode as the light-emitting element EL is shown. In particular, it is preferable to use an organic EL element as the light-emitting element EL.

[0407] The light-emitting element EL corresponds to the above OLED, the transistor M5 corresponds to the above selection transistor, and the transistor M6 corresponds to the above driving transistor. Also, the wiring VS corresponds to the wiring to which the above video data is input.

[0408] For the transistor M5, the gate is electrically connected to the wiring VG, one of the source or drain is electrically connected to the wiring VS, and the other of the source or drain is electrically connected to one electrode of the capacitor C2 and the gate of the transistor M6. One of the source or drain of the transistor M6 is electrically connected to the wiring V4, and the other is electrically connected to the anode of the light-emitting element EL and one of the source or drain of the transistor M7. For the transistor M7, the gate is electrically connected to the wiring MS, and the other of the source or drain is electrically connected to the wiring OUT2. The cathode of the light-emitting element EL is electrically connected to the wiring V5.

[0409] A constant potential is supplied to each of wiring V4 and wiring V5. The anode side of the light-emitting element EL can be set to a high potential, and the cathode side can be set to a potential lower than the anode side. The transistor M5 is controlled by a signal supplied to wiring VG and functions as a selection transistor for controlling the selection state of the pixel circuit PIX2. Further, the transistor M6 functions as a drive transistor that controls the current flowing through the light-emitting element EL according to the potential supplied to the gate. When the transistor M5 is in the conductive state, the potential supplied to wiring VS is supplied to the gate of the transistor M6, and the emission luminance of the light-emitting element EL can be controlled according to that potential. The transistor M7 is controlled by a signal supplied to wiring MS and has one or both of the functions of setting the potential between the transistor M6 and the light-emitting element EL to the potential supplied to wiring OUT2 and outputting the potential between the transistor M6 and the light-emitting element EL to the outside via wiring OUT2.

[0410] FIG. 18E shows an example of a pixel circuit including a memory unit applicable to the configuration illustrated in FIG. 18B.

[0411] The pixel circuit PIX3 shown in FIG. 18E has a configuration in which a transistor M8 and a capacitor C3 are added to the pixel circuit PIX2. In the pixel circuit PIX3, wiring VS in the pixel circuit PIX2 is changed to wiring VS1, and wiring VG is changed to wiring VG1.

[0412] The gate of the transistor M8 is electrically connected to wiring VG2, one of the source and the drain is electrically connected to wiring VS2, and the other is electrically connected to one electrode of the capacitor C3. The other electrode of the capacitor C3 is electrically connected to the gate of the transistor M6, one electrode of the capacitor C2, and the other of the source and the drain of the transistor M5.

[0413] Wiring VS1 corresponds to the wiring to which the video data is supplied. Wiring VS2 corresponds to the wiring to which the weight data is supplied. The node to which the gate of the transistor M6 is connected corresponds to the memory unit.

[0414] An example of the operation method of the pixel circuit PIX3 will be described. First, a first potential is written to the node to which the gate of the transistor M6 is connected via the transistor M5 from the wiring VS1. Then, by setting the transistor M5 to a non-conducting state, the node becomes a floating state. Subsequently, a second potential is written to one electrode of the capacitor C3 from the wiring VS2 via the transistor M8. As a result, due to the capacitive coupling of the capacitor C3, the potential of the above node changes from the first potential to the third potential according to the second potential. Then, a current corresponding to the third potential flows through the transistor M6 and the light-emitting element EL, and the light-emitting element EL emits light with a luminance corresponding to the potential.

[0415] In addition, in the display device of this embodiment, an image may be displayed by causing the light-emitting element to emit light in a pulsed manner. By shortening the driving time of the light-emitting element, it is possible to reduce the power consumption of the display device and suppress heat generation. In particular, since the organic EL element has excellent frequency characteristics, it is suitable. The frequency can be, for example, 1 kHz or more and 100 MHz or less. Also, a driving method (also called Duty driving) of changing the pulse width to emit light may be used.

[0416] Here, it is preferable to apply a transistor using a metal oxide (oxide semiconductor) to the semiconductor layer in which channels are formed for the transistors M1, M2, M3, and M4 included in the pixel circuit PIX1, the transistors M5, M6, and M7 included in the pixel circuit PIX2, and the transistor M8 included in the pixel circuit PIX3.

[0417] Also, transistors in which silicon is applied to the semiconductor in which channels are formed can be used for the transistors M1 to M8. In particular, by using highly crystalline silicon such as single-crystalline silicon and polycrystalline silicon, high field-effect mobility can be realized, and faster operation becomes possible, which is preferable.

[0418] In addition, among transistors M1 to M8, a configuration may be adopted in which transistors applying an oxide semiconductor are used for one or more of them, and transistors applying silicon are used for the others.

[0419] For example, for transistors M1, M2, M5, M7, and M8 that function as switches for holding charges, it is preferable to use transistors applying an oxide semiconductor with an extremely low off-current. At this time, a configuration may be adopted in which transistors applying silicon are used for one or more of the other transistors.

[0420] Note that in pixel circuits PIX1, PIX2, and PIX3, the transistors are described as n-channel transistors, but p-channel transistors may also be used. Alternatively, a configuration in which n-channel transistors and p-channel transistors are mixed may be adopted.

[0421] This embodiment can be implemented in appropriate combination with at least a part of other embodiments described in this specification.

[0422] (Embodiment 4) In this embodiment, a metal oxide (also referred to as an oxide semiconductor) that can be used for the transistors described in the above embodiment will be described.

[0423] The metal oxide preferably contains at least indium or zinc. In particular, it preferably 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.

[0424] In addition, 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.

[0425] <Classification of crystal structures> 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.

[0426] Note that 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 referred to as the thin film method or the Seemann-Bohlin method.

[0427] For example, in a quartz glass substrate, the shape of the peak in the XRD spectrum is almost symmetric about the vertical axis. 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 vertical axis. The fact that the shape of the peak in the XRD spectrum is asymmetric about the vertical axis 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 vertical axis, it cannot be said that the film or the substrate is in an amorphous state.

[0428] In addition, the crystal structure of the film or substrate can be evaluated by the diffraction pattern (also referred to as the nano beam electron diffraction pattern) observed by nano beam electron diffraction (NBED). For example, in the diffraction pattern of a quartz glass substrate, a halo is observed, confirming that the quartz glass is in an amorphous state. Also, in the diffraction pattern of an IGZO film formed at room temperature, a spot-like pattern rather than a halo is observed. Therefore, it is presumed that the IGZO film formed at room temperature is in an intermediate state that is neither crystalline nor amorphous, and it cannot be concluded that it is in an amorphous state.

[0429] [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 non-single crystal oxide semiconductors include the above-mentioned CAAC-OS and nc-OS. In addition, non-single crystal oxide semiconductors include polycrystalline oxide semiconductors, pseudo-amorphous oxide semiconductors (a-like OS: amorphous-like oxide semiconductor), amorphous oxide semiconductors, and the like.

[0430] Here, the details of the above-mentioned CAAC-OS, nc-OS, and a-like OS will be described.

[0431] [CAAC-OS] CAAC-OS is an oxide semiconductor having a plurality of crystal regions, and in the plurality of crystal regions, the c-axis is oriented in a specific direction. Here, the specific direction means the thickness direction of the CAAC-OS film, the normal direction of the surface on which the CAAC-OS film is formed, or the normal direction of the surface of the CAAC-OS film. Also, a crystal region is a region having periodicity in the atomic arrangement. When the atomic arrangement is regarded as a lattice arrangement, the crystal region is also a region where the lattice arrangements are aligned. Furthermore, CAAC-OS has a region where a plurality of crystal regions are connected in the a-b plane direction, and this region may have strain. Here, strain refers to a portion where the 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 a region where a plurality of crystal regions are connected. That is, CAAC-OS is an oxide semiconductor in which the c-axis is oriented and there is no clear orientation in the a-b plane direction.

[0432] Each of the plurality of crystal regions is composed of one or more minute crystals (crystals having a maximum diameter of less than 10 nm). When a crystal region is composed of one minute crystal, the maximum diameter of the crystal region is less than 10 nm. Also, when a crystal region is composed of a number of minute crystals, the size of the crystal region may be on the order of several tens of nm.

[0433] Also, in an In-M-Zn oxide (where the element M is one or more selected from aluminum, gallium, yttrium, tin, titanium, etc.), CAAC-OS tends to have a layered crystal structure (also referred to as a layered structure) in which a layer containing indium (In) and oxygen (hereinafter, In layer) and a layer containing the element M, zinc (Zn), and oxygen (hereinafter, (M,Zn) layer) are laminated. Here, indium and the element M are mutually substitutable. Therefore, the (M,Zn) layer may contain indium. Also, the In layer may contain the element M. Note that the In layer may also contain Zn. The layered structure is observed as a lattice image, for example, in a high-resolution TEM (Transmission Electron Microscope) image.

[0434] 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.

[0435] 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 referred to as the direct spot) as the center of symmetry.

[0436] 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.

[0437] 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 for forming CAAC-OS, a configuration having Zn is preferable. For example, In-Zn oxide and In-Ga-Zn oxide are preferable because they can suppress the generation of grain boundaries more than In oxide.

[0438] CAAC-OS is an oxide semiconductor with high crystallinity and no distinct grain boundaries. Therefore, it can be said that in CAAC-OS, a decrease in electron mobility due to grain boundaries is less likely to occur. Also, since the crystallinity of an oxide semiconductor may decrease due to the incorporation of impurities, generation of defects, 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.

[0439] [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. Since the size of the minute crystals is, for example, 1 nm or more and 10 nm or less, particularly 1 nm or more and 3 nm or less, the minute crystals are also referred to as nano-crystals. Also, nc-OS does not show regularity in the crystal orientation between different nano-crystals. Therefore, no orientation is seen in the entire film. Therefore, depending on the analysis method, nc-OS may not be distinguishable from a-like OS and amorphous oxide semiconductors. For example, when structural analysis is performed on an nc-OS film using an XRD apparatus, no peak indicating crystallinity is detected in 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-crystals (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 the size of the nano-crystals or smaller than the nano-crystals (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 in a ring-shaped region centered on a direct spot may be obtained.

[0440] [a-like OS] The a-like OS is an oxide semiconductor having a structure between nc-OS and an amorphous oxide semiconductor. The a-like OS has a loose or low-density region. That is, the a-like OS has lower crystallinity compared to nc-OS and CAAC-OS. Also, the a-like OS has a higher hydrogen concentration in the film compared to nc-OS and CAAC-OS.

[0441] [[Configuration of Oxide Semiconductor]] Next, the details of the above-mentioned CAC-OS will be described. Note that CAC-OS relates to the material composition.

[0442] [CAC-OS] The CAC-OS is, for example, a configuration of a material in which the elements constituting the metal oxide are unevenly distributed in a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 3 nm or less, or in the vicinity thereof. In the following, in the metal oxide, one or more metal elements are unevenly distributed, and a region having the metal element is in a state of being mixed in a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 3 nm or less, or in the vicinity thereof, which is also referred to as a mosaic state or a patch state.

[0443] 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 distributed in the film (hereinafter, also referred to as a cloud state). That is, the CAC-OS is a composite metal oxide having a configuration in which the first region and the second region are mixed.

[0444] Here, the atomic ratios of In, Ga, and Zn to the metal elements constituting the CAC-OS in the In-Ga-Zn oxide are denoted as [In], [Ga], and [Zn], respectively. For example, in the CAC-OS in the In-Ga-Zn oxide, the first region is a region where [In] is larger than [In] in the composition of the CAC-OS film. Also, the second region is a region where [Ga] is larger than [Ga] in the composition of the CAC-OS film. Or, 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.

[0445] Specifically, the above-mentioned first region is a region mainly composed of indium oxide, indium zinc oxide, etc. Also, the above-mentioned second region is a region mainly composed of gallium oxide, gallium zinc oxide, etc. That is, the above-mentioned first region can be rephrased as a region mainly composed of In. Also, the above-mentioned second region can be rephrased as a region mainly composed of Ga.

[0446] Note that there may be cases where no clear boundary can be observed between the above-mentioned first region and the above-mentioned second region.

[0447] Also, the CAC-OS in the In-Ga-Zn oxide refers to a structure in a material composition containing In, Ga, Zn, and O, where a region mainly composed of Ga in part and a region mainly composed of In in part are each in a mosaic shape and these regions exist randomly. Therefore, it is presumed that the CAC-OS has a structure in which the metal elements are unevenly distributed.

[0448] CAC-OS can be formed by sputtering, for example, under conditions where the substrate is not 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.

[0449] 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.

[0450] Here, the first region is a region with higher conductivity compared to the second region. That is, when carriers flow through the first region, the conductivity as a metal oxide is exhibited. 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.

[0451] On the other hand, the second region is a region with higher insulating properties compared to the first region. That is, when the second region is distributed in the metal oxide, the leakage current can be suppressed.

[0452] 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 (the function of turning on / off) to be imparted to the CAC-OS. That is, CAC-OS has a conductive function in part of the material and an insulating function in 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 maximally enhanced. Thus, 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.

[0453] In addition, a transistor using CAC-OS has high reliability. Therefore, CAC-OS is optimal for various semiconductor devices including display devices.

[0454] Oxide semiconductors have various structures, each with 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, an a-like OS, a CAC-OS, an nc-OS, and a CAAC-OS.

[0455] <Transistor having an oxide semiconductor> Subsequently, the case of using the above oxide semiconductor in a transistor will be described.

[0456] By using the above oxide semiconductor in a transistor, a transistor with high field-effect mobility can be realized. In addition, a highly reliable transistor can be realized.

[0457] 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. In addition, an oxide semiconductor with a low carrier concentration may be referred to as a high-purity intrinsic or substantially high-purity intrinsic oxide semiconductor.

[0458] In addition, since an oxide semiconductor film that is high-purity intrinsic or substantially high-purity intrinsic has a low density of defect levels, the density of trap levels may also be low.

[0459] In addition, the charge trapped in the trap levels of the oxide semiconductor takes 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.

[0460] Therefore, in order to stabilize the electrical characteristics of the transistor, it is effective to reduce the impurity concentration in the oxide semiconductor. In addition, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in the adjacent film. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, silicon, and the like.

[0461] <Impurity> Here, the influence of each impurity in the oxide semiconductor will be described.

[0462] In an oxide semiconductor, when silicon, carbon, which is one of the Group 14 elements, etc. are included, defect levels are formed in the oxide semiconductor. Therefore, the concentration of silicon, carbon, etc. in the oxide semiconductor and the concentration of silicon, carbon, etc. 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.

[0463] In addition, when an alkali metal or an alkaline earth metal is included 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 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.

[0464] In addition, in an oxide semiconductor, when nitrogen is included, 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 included 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 5×10 18 atoms / cm 3 or less, more preferably 1×10 18 atoms / cm 3 or less, even more preferably 5×10 17 atoms / cm 3 or less.

[0465] In addition, hydrogen contained in the oxide semiconductor may react with oxygen bonded to metal atoms to form water, thereby forming oxygen vacancies. 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.

[0466] By using an oxide semiconductor with sufficiently reduced impurities in the channel formation region of a transistor, stable electrical characteristics can be imparted.

[0467] This embodiment can be implemented in appropriate combination with at least some of the other embodiments described herein.

Description of Reference Numerals

[0468] 10: Vehicle control device, 20, 20a to 20d: Light emitting and receiving units, 21, 21R, 21G, 21B, 21IR: Light emitting elements, 22: Light receiving element, 23: Drive circuit, 24: Readout circuit, 25r: Reflected light, 25: Light, 30: Control unit, 31: Data generation unit, 32: Determination unit, 33: Processing unit, 40: Operation unit, 41: Steering wheel, 42: Rim, 42a, 42b: Members, 43: Hub, 44: Spoke, 45: Shaft, 51: Hand, 51L: Left hand, 51R: Right hand

Claims

【Claim 1】 An operation unit, a first light transmitting and receiving unit, and a control unit, wherein the operation unit includes a steering wheel having a rim, a hub, and spokes, the rim is connected to the hub via the spokes, the first light transmitting and receiving unit is provided along the surface of the rim, the first light transmitting and receiving unit includes a first light emitting element and a first light receiving element, the first light emitting element has a function of emitting light in a first wavelength range, the first light receiving element has a function of receiving light in the first wavelength range and converting it into an electrical signal, the first light emitting element and the first light receiving element are arranged side by side on the same plane, the first light transmitting and receiving unit has a function of sequentially outputting received light data to the control unit, the control unit is a vehicle control device having a function of acquiring the driver's biometric information from a plurality of the received light data and executing processing according to the biometric information.

Images