Vehicle control device

Abstract

Provided is a vehicle control device with high safety. The vehicle control device includes an operation unit, a light receiving / emitting unit, and a control unit. The operation unit includes a steering wheel that has a rim, a hub, and a spoke. The rim is connected to the hub via the spoke. The light receiving / emitting unit is disposed along the surface of the rim. The light receiving / emitting unit includes a first light emitting element and a first light receiving element. The first light emitting element has a function for emitting light of a first wavelength region. The first light receiving element has a function for receiving the light of the first wavelength region and converting same to an electrical signal. The first light emitting element and the first light receiving element are arranged side by side on the same plane. The light receiving / emitting unit has a function for sequentially outputting light reception data to the control unit. The control unit has a function for acquiring biological information of a driver from a plurality of pieces of light reception data and executing processing corresponding to the biological information.

Description

[Technical field]

[0001] 1. Field of the Invention The present invention relates to a control device for a moving body such as a vehicle. 1. Field of the Invention The present invention relates to a light receiving and emitting device. 1. Field of the Invention The present invention relates to a biosensor. 1. Field of the Invention The present invention relates to a biometric authentication technology.

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

[0003] For drivers who are driving a vehicle, accidents caused by drowsiness are one of the most common accidents, and various methods for monitoring the driver's wakefulness have been considered. For example, Patent Document 1 discloses a technology for determining the driver's activity level from the vehicle's acceleration and the driver's heart rate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-312653 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of one embodiment of the present invention is to provide a vehicle control device with high safety.An object of one embodiment of the present invention is to provide a vehicle control device with high convenience.An object of one embodiment of the present invention is to monitor a driver's state without the driver being aware of it.An object of one embodiment of the present invention is to provide a vehicle control device, a vehicle control method, or the like having a novel configuration.

[0006] An object of one embodiment of the present invention is to provide a new electronic device, a mobile object, a vehicle, an apparatus, a system, a program, or a method that utilizes biometric information.An object of one embodiment of the present invention is to provide an electronic device, a mobile object, a vehicle, an apparatus, a system, a program, or a method having a novel configuration.An object of one embodiment of the present invention is to alleviate at least one of the problems of the prior art.

[0007] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these can be extracted from the description of the specification, drawings, claims, etc. [Means for solving the problem]

[0008] One aspect of the present invention is a vehicle control device having an operation unit, a first light receiving and emitting unit, and a control unit. The operation unit has a steering wheel having a rim, a hub, and spokes. The rim is connected to the hub via the spokes. The first light receiving and emitting unit is provided along the surface of the rim. The first 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 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 surface. The first light receiving and emitting unit has a function of sequentially outputting light receiving data to the control unit. The control unit has a function of acquiring biometric information of the driver from the multiple light receiving data, and executing processing according to the biometric information.

[0009] In the above, the biological information is preferably one or more of a pulse wave, a heart rate, a pulse rate, and an arterial blood oxygen saturation level.

[0010] In the above, the biometric information is preferably information on veins, fingerprints, or palm prints.

[0011] In any of the above, it is preferable to further include a second light receiving / emitting unit. In this case, the second light receiving / emitting unit is provided along the surface of the hub or spoke. The second light receiving / emitting unit also includes a second light emitting element and a second light receiving element. It is preferable that the second light emitting element has a function of emitting light in a second wavelength range, and the second light receiving element has a function of receiving light in the second wavelength range and converting it into an electrical signal.

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

[0013] In any of the above, it is preferable that the first light receiving and emitting unit further includes a third light emitting element. In this case, it is preferable that the third light emitting element has a function of emitting light in a third wavelength range including visible light.

[0014] In any of the above, it is preferable that the second light receiving and emitting unit further includes a fourth light emitting element. In this case, it is preferable that the fourth light emitting element has a function of emitting light in a fourth wavelength range including visible light.

[0015] In any of the above, the first light-emitting element preferably has a laminated structure in which a first electrode, a light-emitting layer, and a common electrode are laminated. Furthermore, the first light-receiving element preferably has a laminated structure in which a second electrode, an active layer, and a common electrode are laminated. In this case, it is preferable that the light-emitting layer and the active layer each contain different organic compounds. Furthermore, it is preferable that the first electrode and the second electrode are provided separately on the same plane. Furthermore, it is preferable that the common electrode is provided so as to cover the light-emitting layer and the active layer.

[0016] Alternatively, in any of the above, the first light-emitting element preferably has a laminated structure in which a first electrode, a common layer, a light-emitting layer, and a common electrode are laminated. Furthermore, the first light-receiving element preferably has a laminated structure in which a second electrode, a common layer, an active layer, and a common electrode are laminated. In this case, it is preferable that the light-emitting layer and the active layer each contain different organic compounds. Furthermore, it is preferable that the first electrode and the second electrode are provided separately on the same plane. Furthermore, 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. Effect of the Invention

[0017] According to one aspect of the present invention, it is possible to provide a vehicle control device with high safety, a vehicle control device with high convenience, a driver's state can be monitored without the driver being aware of it, or a vehicle control device or a vehicle control method having a novel configuration can be provided.

[0018] According to one aspect of the present invention, it is possible to provide a new electronic device, a mobile object, a vehicle, an apparatus, a system, a program, or a method that utilizes biometric information, or to provide an electronic device, a mobile object, a vehicle, an apparatus, a system, a program, or a method having a novel configuration, or to alleviate at least one of the problems of the prior art.

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

[0020] 1A to 1C are diagrams illustrating an example of the configuration of a vehicle control device. 2A and 2B are diagrams illustrating an example of the configuration of a vehicle control device. 3A to 3D are diagrams illustrating an example of the configuration of a vehicle control device. Figures 4A to 4D are diagrams illustrating an example of the configuration of a vehicle control device, and Figures 4E to 4G are diagrams illustrating an example of the configuration of pixels of a light receiving and emitting unit. FIG. 5 is a flowchart illustrating an example of a method for operating the vehicle control device. FIG. 6 is a flowchart showing an example of a method for operating the vehicle control device. Fig. 7A is a diagram showing an example of the configuration of a game system, and Fig. 7B and Fig. 7C are examples of images of a game. Fig. 8A, Fig. 8B, and Fig. 8D are cross-sectional views showing an example of a display device, Fig. 8C and Fig. 8E are diagrams showing examples of images captured by the display device, and Fig. 8F to Fig. 8H are top views showing examples of pixels. Fig. 9A is a cross-sectional view showing an example of the configuration of a display device, and Figs. 9B to 9D are top views showing an example of a pixel. Fig. 10A is a cross-sectional view showing a configuration example of a display device, Fig. 10B to Fig. 10I are top views showing an example of a pixel. 11A and 11B are diagrams showing a configuration example of a display device. 12A to 12G are diagrams showing configuration examples of the display device. 13A to 13C are diagrams showing configuration examples of a display device. 14A to 14C are diagrams showing configuration examples of a display device. 15A and 15B are diagrams showing a configuration example of a display device. FIG. 16 is a diagram showing a configuration example of a display device. Fig. 17A is a diagram showing a configuration example of a display device, Fig. 17B and Fig. 17C are diagrams showing configuration examples of a transistor. 18A and 18B are diagrams illustrating an example of a pixel configuration, and Fig. 18C to Fig. 18E are diagrams illustrating an example of a pixel circuit configuration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, the embodiments will be described with reference to the drawings. However, it will be easily understood by those skilled in the art that the embodiments can be implemented in many different ways, and that the modes and details can be changed in various ways without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the following embodiments.

[0022] In the configuration of the invention described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and the repeated explanations are omitted. In addition, when referring to similar functions, the same hatch pattern may be used and no particular reference numeral may be used.

[0023] In addition, in each figure described in this specification, the size of each component, the thickness of a layer, or an area may be exaggerated for clarity, and therefore, the drawings are not necessarily limited to the scale.

[0024] In addition, ordinal numbers such as "first" and "second" in this specification are used to avoid confusion of components and do not limit the numbers.

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

[0026] [Configuration example 1] 1A shows a block diagram of a vehicle control device 10, which will be described below as an example. The vehicle control device 10 includes a light receiving and emitting 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 receiving data including the driver's biometric information, and a function of outputting the light receiving data to the control unit 30. The control unit 30 has a function of generating (acquiring) data including the driver's biometric information (also called biometric data) based on the light receiving and emitting data supplied from the light receiving and emitting unit 20, and a function of executing various processes based on the biometric data. The operation unit 40 corresponds to an operation means with which the driver operates the vehicle. The operation unit 40 has a light receiving and emitting area of ​​the light receiving and emitting unit 20 provided along a part that the driver holds or touches.

[0028] The light receiving and emitting unit 20 has a function of, for example, irradiating light onto a part of the driver's body and acquiring the reflected light as light receiving data. The light receiving and emitting unit 20 can acquire biometric data such as a fingerprint or palm print by capturing an image of 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 can be realized in which the engine (or power source) can be started by biometric authentication without carrying a key.

[0029] Here, since the reflectance of light by human skin changes periodically due to blood flow, pulse wave data can be obtained from the time change in the received light luminance, which can be obtained by repeatedly receiving light using the light receiving / emitting unit 20. From the pulse wave, various vital data can be obtained. For example, the heart rate can be obtained from the pulse wave period. In addition, the arterial blood oxygen saturation (SpO2) can be measured using two pieces of received light data obtained using light of different wavelengths (for example, infrared light and red light). In addition, stress level, vascular age, etc. can be obtained from the highly accurate pulse wave obtained by increasing the sampling frequency. In addition, it is possible to estimate the degree of progression of arteriosclerosis, and to estimate blood pressure from separately measured electrocardiogram and pulse wave.

[0030] Biometric data that can be used by the control unit 30 can be roughly divided into vital data and biometric authentication data. Vital data is data related to life information derived from a person's life activities, such as pulse wave, heart rate, pulse rate, arterial blood oxygen saturation, and blood pressure. On the other hand, biometric data is data derived from a person's physical characteristics and can be used for personal authentication (biometric authentication), such as fingerprints, palm prints, pulse shape (including vein shape and arterial shape), irises, and voiceprints. Data derived from a person's behavioral characteristics (such as the position at which the steering wheel is gripped) can also be included in biometric data.

[0031] Visible light, infrared light, or ultraviolet light can be used as the light irradiated to a part of the driver's body by the light receiving and emitting unit 20. In particular, it is preferable that the light includes infrared light, preferably near-infrared light. Such light is preferable because it is not visible to the driver and can be used to capture images at all times without interfering with the driver's driving.

[0032] 1A, the light receiving and emitting unit 20 has a light emitting element 21, a light receiving element 22, a drive circuit 23, and a readout circuit 24. The control unit 30 has a data generating unit 31, a determining unit 32, a processing unit 33, etc. The operation unit 40 has at least a steering wheel 41. The steering wheel 41 has a rim 42, a hub 43, and spokes 44.

[0033] In the light receiving and emitting 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 is sensitive 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 is also sensitive 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 wavelength range of 700 nm to 2500 nm can be suitably used. In particular, the use of light having one or more peaks in the wavelength range of 750 nm to 1000 nm is preferable because it broadens the range of materials to be selected for the active layer of the light-receiving element 22.

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

[0036] It is preferable to use an EL element such as an OLED (Organic Light Emitting Diode) or a QLED (Quantum-dot Light Emitting Diode) as the light-emitting element 21. Examples of the light-emitting material contained in the EL element include a material that emits fluorescence (fluorescent material), a material that emits phosphorescence (phosphorescent material), a material 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 light incident on the light receiving element and generates an electric charge. The amount of electric charge generated by the photoelectric conversion element is determined according to the amount of incident light. In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light receiving element. Organic photodiodes can be easily made thin, lightweight, and large in area, and have a high degree of freedom in shape and design, so that they can be applied to various devices.

[0038] In addition, it is preferable to use an organic compound for the active layer of the light receiving element 22. In this case, it is preferable to provide one electrode (also called a pixel electrode) of the light emitting element 21 and the light receiving element 22 on the same surface. Furthermore, it is more preferable to make the other electrode of the light emitting element 21 and the light receiving element 22 an electrode (also called a common electrode) formed of one continuous conductive layer. Furthermore, it is more preferable that the light emitting element 21 and the light receiving element 22 have a common layer. This can simplify the manufacturing process when manufacturing the light emitting element 21 and the light receiving element 22, reduce manufacturing costs, and improve manufacturing yield.

[0039] The driving circuit 23 has a circuit for controlling the emission of the light-emitting element 21 and a circuit for controlling the reception of light by the light-receiving element 22. For example, when the light-receiving and light-emitting unit 20 has a configuration in which a plurality of pixels, each including the light-emitting element 21 and the light-receiving element 22, are arranged in a matrix, the driving circuit 23 includes a pixel circuit, a scanning line driving circuit, a signal line driving circuit, and the like, which the pixels have.

[0040] The readout circuit 24 has a function of generating light reception data based on the electrical signal output by the light receiving element 22 and outputting the data to the control unit 30. For example, the readout circuit 24 includes an amplifier circuit, an AD conversion circuit, etc. The light reception 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-receiving / emitting surface of the light-receiving / emitting unit 20, and enters the light-receiving element 22. The light-receiving element 22 outputs an electrical signal according to the amount of incident light. This makes it possible to detect the touch or approach of an object.

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

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

[0044] The determination unit 32 has a function of determining whether or not to cause the processing unit 33 to execute a process, based on the biometric data supplied from the data generation unit 31. The determination unit 32 also has a function of selecting a process to be executed by the processing unit 33, based on the biometric data.

[0045] The light receiving and emitting unit 20 and the data generating unit 31 can periodically and continuously acquire various vital data or biometric data, so that the judgment unit 32 can use this vital data or biometric data for personal authentication, driver condition management, and the like.

[0046] For example, biometric data that can be obtained using visible light and infrared light include fingerprints, palm prints, vein shapes, pulse waves, respiratory rate, pulse rate, oxygen saturation, blood sugar levels, and neutral fat concentrations. Biometric data that can be obtained by other means include facial expressions, complexion, pupils, and voiceprints. Using such various biometric data is preferable because it allows a comprehensive assessment of the user's health condition.

[0047] Each of the measured biometric data may be individually judged as to whether it is a normal value or an abnormal value, and processing may be determined based on the multiple judgment results. Alternatively, the driver's condition may be judged for each of the measured biometric data (for example, the pulse rate may be judged as high, low, or normal) and processing may be determined based on the multiple judgment results. Such a method has the advantage that the grounds for the obtained judgment results are clear.

[0048] On the other hand, feature amounts may be extracted from all the measured biometric data, and processing may be determined from the feature amounts. According to such a method, it is easy to make a judgment based on the correlation between multiple pieces of biometric data, not just on each piece of biometric data.

[0049] As a classifier or discriminator for determining processing from various biological data, a machine learning model trained by machine learning is preferably used. Machine learning can be broadly divided into supervised machine learning, unsupervised machine learning, outlier detection, and the like.

[0050] Supervised machine learning techniques include the K-nearest neighbor method, naive Bayes classifier, decision tree, support vector machine, random forest, neural network, etc. In particular, neural networks are suitable for extracting features from multiple pieces of information, as they can learn at the feature extraction stage.

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

[0052] A supervised machine learning model and an unsupervised machine learning model may be combined to determine the acquired multiple pieces of biometric data. In this case, labels used in other supervised machine learning models may be used as labels for each classification obtained by the unsupervised machine learning model.

[0053] Outlier detection detects whether the acquired biometric data or the feature amount obtained from one or more pieces of biometric data is an outlier outside the normal range. When an outlier is detected, it is estimated that there is a high possibility that the driver's condition is out of the normal range.

[0054] Models for detecting outliers include the k-nearest neighbor method, local outlier factor, one class SVM, and Mahalanobis distance. For outlier detection, it is effective to use multidimensional data that combines various information. False positives can be prevented by performing outlier detection based on multiple pieces of information. In addition, if the biometric data is information that changes over time depending on the user's condition, etc. (pulse rate, respiratory rate, etc.), a nearest neighbor method using a sliding window, a dynamic time warping (DTW) method, a singular spectral transform method, etc. may be used. In addition, if the biometric information changes periodically, deviations from the prediction model may be detected using LSTM (Long Short Term Memory) or the like.

[0055] The determination unit 32 may also have a function of executing a process (authentication process) of collating the fingerprint, palm print, or blood vessel shape information input from the data generation unit 31 with the driver's fingerprint, palm print, or blood vessel shape information stored in advance and determining whether or not they match. As a method used for the authentication process executed by the determination unit 32, for example, a template matching method or a pattern matching method that compares two images and uses their similarity can be used. Furthermore, the fingerprint authentication process may be executed by inference using machine learning. In this case, it is preferable that the authentication process is executed by inference using a neural network in particular.

[0056] The processing unit 33 has a function of executing various processes depending on 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 transition the vehicle to a drivable state (also called an idling state). In addition, when the driver is authenticated by the determination unit 32, the processing unit 33 may execute processing to prepare the environment inside the vehicle to suit the driver's preferences. For example, it is preferable that the processing unit 33 executes one or more of the following after authentication: adjusting the seat position, adjusting the steering wheel position, adjusting the directions of the side mirrors and the rearview mirror, setting the brightness, setting the air conditioner, setting the speed and frequency of the wipers, setting the audio volume, reading the audio playlist, and the like.

[0058] Furthermore, when the determination unit 32 determines the degree of wakefulness of the driver, the processing unit 33 executes processing according to the degree. For example, the brightness inside the vehicle may be changed or a sound may be played to encourage the driver to wake up. Furthermore, when it is determined that the driver is in a state where he or she cannot drive, for example, the processing unit 33 may change the driving mode of the vehicle to an emergency automatic driving mode, blink the hazard lights, move the vehicle to the shoulder of the road, contact the police, an ambulance, an insurance company, etc.

[0059] Furthermore, the determination unit 32 may have a function for determining whether or not alcohol has been consumed based on the biological data, and a function for determining whether or not an attack of heart disease has occurred.

[0060] Furthermore, the determination unit 32 may have a function of constantly monitoring whether or not the driver is gripping the steering wheel 41. Depending on the type of autonomous driving, it may be required to constantly grip the steering wheel 41. For example, when the determination unit 32 determines that the driver has taken his or her hands off the steering wheel 41, the processing unit 33 may execute a process of warning the driver to grip the steering wheel 41.

[0061] The rim 42 of the steering wheel 41 functions as a grip part that is held by the driver and has an annular shape. The hub 43 is connected to an axis (shaft) extending from the vehicle and is located at the center of the steering wheel 41. The spokes 44 are parts that connect the rim 42 and the hub 43. There may be only one spoke 44, but two or more spokes are preferable because they increase the strength of the steering wheel 41. For example, it is preferable that a plurality of spokes 44 (typically two to four) are provided radially from the hub 43 as the center.

[0062] The hub 43 and the spokes 44 may be provided with an operation switch or an operation panel (touch panel).

[0063] The operation unit 40 may include, in addition to the steering wheel 41, operation levers such as a column shift and a paddle shift, and operation levers for indicators, windshield wipers, etc.

[0064] Here, at least a part of the light receiving and emitting unit 20 is provided along the surface of the rim 42 of the steering wheel 41. In this way, when the driver grips the rim 42, light receiving data of a part of the palm of the driver's hand can be obtained.

[0065] [Configuration Example 1-1] Fig. 1B shows a perspective view of an example of a steering wheel 41 equipped with a light receiving and emitting unit 20. Fig. 1B also shows a part of a shaft 45 connected to a hub 43.

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

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

[0068] 1C shows the driver holding the rim 42 with his left hand 51L and right hand 51R. At this time, the light-emitting element 21 emits light and the light-receiving element 22 receives light, thereby capturing images of parts of the palms of the driver's left hand 51L and right hand 51R. The light-receiving and light-emitting unit 20 has an annular upper surface shape similar to the surface of the rim 42, so that imaging can always be performed regardless of where the left hand 51L and right hand 51R are holding the rim 42.

[0069] The light receiving and emitting unit 20 is disposed on the driver's side surface of the rim 42, so that the light receiving and emitting unit 20 is located inside the field of vision of the driver. In this case, by using a light emitting element that emits infrared light as the light emitting element 21, it is possible to capture images without causing the driver to feel dazzled.

[0070] Note that a light-emitting element that emits visible light may be used as the light-emitting element 21. In that case, it is important to suppress the emission luminance during imaging to a level that does not dazzle 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 is translucent. The light receiving and emitting unit 20 is located inside the rim 42 and is provided along a part of the member 42b. The light receiving and emitting unit 20 can emit light 25 through the translucent member 42b. Furthermore, reflected light 25r reflected by the object is transmitted through the member 42b and enters the light receiving and emitting unit 20.

[0073] 2A, a part of the surface (the surface that touches the hand) of member 42b is flat. This makes it possible to make the imaging surface flat, so that when capturing an image to be used for authentication, such as a fingerprint, palm print, or blood vessel shape, an image with little distortion can be captured.

[0074] 2B, the surface may be curved. This allows the cross section of the rim 42 to be annular, which makes it easier for the driver to grip the rim 42 compared to a flat surface. Also, a part of the member 42b can function as a lens.

[0075] 2A and 2B, it is preferable that the light emitting and receiving unit 20 is attached to a flat surface. This eliminates the need to provide flexibility to the light emitting and receiving unit 20, thereby reducing manufacturing costs.

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

[0077] Figure 3B shows a schematic cross-sectional view of the rim 42 taken along the cutting plane A shown in Figure 3A. Figure 3B roughly corresponds to Figure 2A rotated 90 degrees clockwise.

[0078] 3A, the light receiving and emitting unit 20 is attached along the member 42b in a rectangular shape. Since the light receiving and emitting unit 20 needs to be attached to a curved surface, it is preferable that the light receiving and emitting unit 20 has flexibility. For example, it is preferable that the light receiving and emitting unit 20 uses an organic resin as a base material on which the light emitting element 21 and the light receiving element 22 are supported. Alternatively, the base material may be thin glass that is flexible.

[0079] [Configuration Example 1-3] The steering wheel 41 shown in FIG. 3C illustrates an example in which the light receiving and emitting unit 20 is disposed over most of the surface of the rim .

[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 rear side of the rim 42 (the side opposite to the driver side). The light receiving and emitting 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 developable, and the light receiving and emitting surface of the light receiving and emitting unit 20 also forms a three-dimensional curved surface. Therefore, when the light receiving and emitting unit 20 is attached along the inner surface of the member 42a, it is preferable that the light receiving and emitting unit 20 is stretchable. For example, it is preferable that the light receiving and emitting unit 20 uses an elastic body such as rubber as a base material on which the light emitting element 21 and the light receiving element 22 are supported.

[0081] The configuration shown in Fig. 3C allows the area that can be imaged to be larger, thereby improving the sensitivity of the image. For example, in the case of estimating a pulse wave from the time change in the reflectance of the skin, the higher the sensitivity, the higher the accuracy, which is preferable. In addition, the fingerprint, palm print, blood vessel shape, etc. used for authentication can be imaged over a wide range, thereby improving the accuracy of authentication.

[0082] [Configuration example 2] A configuration including a plurality of light receiving and emitting units will be described below.

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

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

[0085] For example, the light receiving and emitting unit 20a can be used to obtain biometric information such as a fingerprint, palm print, etc., for authentication. Fig. 4B shows a state in which a hand 51 is held over the light receiving and emitting unit 20a.

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

[0087] The light receiving and emitting unit 20a provided in 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 receiving and emitting unit 20a may function as a touch panel. This allows various information to be displayed on the light receiving and emitting unit 20a. For example, the light receiving and emitting unit 20a may be used as a display unit of a navigation system.

[0088] [Configuration Example 2-2] FIG. 4C shows an example in which light emitting and receiving parts are provided along the surface of spokes 44.

[0089] 4C , of the three spokes 44, the spoke 44 located on the lower side is provided with the light receiving and emitting unit 20b, the spoke 44 located on the left side is provided with multiple light receiving and emitting units 20c, and the spoke 44 located on the right side is provided with multiple light receiving and emitting units 20d. Note that the number of spokes 44 and the number of light receiving and emitting units are not limited to this and can be changed appropriately depending on the purpose.

[0090] Similarly to the light receiving / emitting unit 20, each of the light receiving / emitting units 20b, 20c, and 20d has a configuration in which a light emitting element and a light receiving element are arranged side by side.

[0091] For example, fingerprint information of the driver can be obtained by the light receiving and emitting unit 20b and authentication can be performed using the obtained information. Fig. 4D shows a state in which the fingers of a hand 51 are held over the light receiving and emitting unit 20b.

[0092] Moreover, it is preferable that the light receiving and emitting units 20c and 20d each function as a touch sensor. The driver can operate the navigation system, audio system, communication system, etc. of the vehicle by touching the light receiving and emitting units 20c and 20d. In addition, the configuration may be such that various operations can be performed, such as adjusting the rearview mirror, adjusting the side mirrors, turning on and off the interior lighting and adjusting the brightness, and opening and closing the windows.

[0093] Moreover, it is preferable that the light receiving / emitting unit 20b, the light receiving / emitting unit 20c, and the light receiving / emitting unit 20d include a light emitting element that emits visible light. Alternatively, both a light emitting element that emits visible light and a light emitting element that emits infrared light may be included. This makes it possible to indicate the position of the light receiving / emitting unit to the driver even at night. Alternatively, concaves and convexes for indicating the position of the light receiving / emitting unit may be arranged on the surface of the light receiving / emitting unit 20b, the light receiving / emitting unit 20c, and the light receiving / emitting unit 20d or on the surface in the vicinity thereof.

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

[0095] In the above, a case has been described in which the light emitting and receiving units 20 provided on the rim 42 are all provided in a continuous manner along the circumferential direction of the rim 42, but the light emitting and receiving units 20 do not necessarily have to have a continuous annular shape, and may have an arc-shaped upper surface shape that follows the surface of the rim 42. In other words, there may be portions in the circumferential direction of the rim 42 where the light emitting and receiving units 20 are not provided. Also, multiple light emitting and receiving units 20 may be arranged along the surface of the rim 42. In this case, the multiple light emitting and receiving units 20 may be arranged so that two adjacent light emitting and receiving units 20 overlap each other, thereby forming a continuous light emitting and receiving region along the circumferential direction of the rim 42.

[0096] [Example of configuration of light receiving and emitting unit] An example of the configuration of a light emitting / receiving unit having two or more types of light emitting elements will be described below. In the light emitting / receiving unit exemplified below, the light emitting elements can be used not only as a light source for imaging but also for displaying an image. In other words, the light emitting / receiving unit exemplified below also functions as a display unit. Such a light emitting / receiving unit can be applied to the light emitting / receiving unit 20 and the light emitting / receiving units 20a to 20d, etc.

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

[0098] 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 is sensitive to at least infrared light. The light receiving element 22 may be sensitive to blue light and infrared light.

[0099] The light receiving and emitting unit shown in Fig. 4E can display a blue image, can be illuminated in blue, and so on. Blue light is preferable because it is less dazzling and does not interfere with driving even when illuminated at night. Note that the visible light emitting element provided in the light receiving and emitting unit is not limited to a blue light emitting element, and light emitting elements of other colors such as red and green may be used.

[0100] 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 is sensitive to at least infrared light. The light receiving element 22 may be sensitive 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. Even when no image is displayed, that is, when no visible light is emitted from the light emitting and receiving unit, imaging can be performed using infrared light.

[0102] 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 red, blue, and green.

[0103] The light receiving and emitting unit shown in FIG. 4G has a function of capturing images using visible light as a light source instead of infrared light. Also, full-color images can be displayed. Also, since the light emitting element 21IR is not provided as compared to FIG. 4F, it is possible to arrange pixels at a higher density, and images with higher resolution 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 emitted light can be increased.

[0104] [Example of how it works] An example of a method of operating the vehicle control device 10 according to one embodiment of the present invention will now be described.

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

[0106] First, in step S0, the operation starts.

[0107] In step S1, light reception data is acquired by the light receiving and emitting unit 20. Specifically, the light emitting element 21 is caused to emit light, the light is received by the light receiving element 22, and the light reception data is read by the read circuit 24. Also, in step S1, the light reception data may be output from the read circuit 24 to the control unit 30.

[0108] In step S2, the data generating unit 31 extracts the biometric data. Specifically, the data generating unit 31 generates the necessary biometric data from the received light data supplied from the light receiving and emitting unit 20. For example, vital data such as pulse wave waveform data, 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. In addition, biometric data such as fingerprints, palm prints, and blood vessel shapes can also be generated as the biometric data.

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

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

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

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

[0113] The above is a description of one example of the operation method.

[0114] In the above-described driving method example, various data can be used as the biological data that can be used for the judgment of the judgment unit 32. Furthermore, the processing performed by the processing unit 33 based on the judgment of the judgment unit 32 is also diverse. An example of such a case will be described below.

[0115] Fig. 6 shows a flowchart of an operation for determining the wakefulness state of the driver and warning 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 generating unit 31 extracts the heart rate as vital data.

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

[0118] For example, the determination unit 32 can estimate the driver's alertness level from a slowing of the heart rate itself, a change in the fluctuation of the heart rate, and the like.

[0119] In step S14, the processing unit 33 performs a warning process for the driver. The warning process can make the driver aware of a decrease in the level of alertness or encourage the driver to be alert by providing a stimulus to the driver's vision, hearing, touch, or smell. Specific examples of the process executed by the processing unit 33 include playing a sound, increasing the volume, vibrating the seat, seat belt, steering wheel, etc., changing the brightness inside the vehicle, opening the windows, and dispersing a scent from an aroma diffuser.

[0120] This concludes the explanation of the flowchart in FIG.

[0121] If the awakening level is too high, it can be determined that the driver is in an excited state, and processing can be executed to make the driver aware of the situation or to calm the driver down.

[0122] In this way, the vehicle control device according to one aspect of the present invention can monitor various physical conditions of the driver and changes therein from vital data obtainable by the light receiving and emitting unit, and can execute various processes according to the driver's condition so as to continue safe driving or to avoid danger.

[0123] [Variations] One aspect of the present invention is capable of detecting a user's physical or mental state by using a light receiving and emitting unit and executing a process according to the state. Therefore, the present invention can be applied to various uses other than a vehicle control device. Here, an example of applying one aspect of the present invention to a game system will be described.

[0124] 7A shows a game system 60. The game system 60 includes a main body 61, a controller 62, and a monitor 63. The monitor 63 can display images output by the main body 61. The main body 61 and the controller 62 transmit and receive data via wireless communication.

[0125] The controller 62 has a pair of gripping parts, and the light receiving and emitting part 20 is provided along the surfaces of the gripping parts. In addition, the controller 62 also has a plurality of buttons.

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

[0127] The main body 61 can execute a game program. The game program may be installed in a storage area (such as a hard disk drive (HDD) or a solid state disk (SSD)) of the main body 61, or may be stored in a recording medium such as a flash memory, a Blu-ray disc, or a DVD.

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

[0129] In the following, an example will be given in which an aspect of the present invention is applied to a soccer game as a game program.

[0130] In a soccer game, one or more characters that can be controlled by a player are set. Each character is set with a plurality of unique parameters that determine the individual characteristics. For example, the unique parameters include speed, stamina, concentration, dribbling skill, shooting skill, passing skill, and defense skill. The unique parameters can increase or decrease depending on the character's training level.

[0131] In addition to the inherent parameters, variable parameters are set for the character. The variable parameters are parameters that change from time to time according to the vital data of the player. The type of the variable parameters may be the same as that of the inherent parameters. Alternatively, the variable parameters may be set as parameters separate from the inherent parameters.

[0132] Each parameter that determines the characteristics of a character is determined by two parameters: an inherent parameter and a variable parameter. For example, a character's parameters may simply be the sum or product of an inherent parameter and a variable parameter, or may be determined based on a predetermined formula.

[0133] Here, there may be parameters that increase (rise) and parameters that decrease (fall) according to the vital data of the player. For example, as the player's heart rate increases, the concentration parameter may decrease, while parameters such as dribbling skill and defensive skill may increase.

[0134] The light reception data acquired by the light receiving and emitting unit 20 of the controller 62 is wirelessly transmitted to the main body 61. A data generation unit in the main body 61 generates vital data based on the light reception data. The game program sets the character's variable parameters based on the vital data. The vital data is generated as needed during play, and the character's variable parameters are updated as needed in response to changes in the vital data.

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

[0136] The shoot area 72 indicates the range of the trajectory of the ball after a shot. Since the trajectory of the ball after a shot is contained within the shoot area 72, the narrower the shoot area 72, the higher the accuracy of the shot. The size, shape, etc. of the shoot area 72 are influenced by the parameters of the character, such as concentration, shooting skill, etc.

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

[0138] For example, Fig. 7C shows a case where the heart rate is 120 bpm, which is much higher than that shown in Fig. 7B. In Fig. 7C, the shooting area 72 is significantly wider than in Fig. 7B, which indicates that the accuracy of the shot is lower.

[0139] In this way, by linking the vital data of the player with the parameters that determine the characteristics of the character, it is possible to provide a game program with a high sense of realism. Furthermore, multiple people can play at the same time using multiple controllers 62, and multiple people can play at the same time online via the Internet.

[0140] The above is a description of the modified example.

[0141] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification.

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

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

[0144] Alternatively, the light-emitting and receiving device of one embodiment of the present invention may have a structure including a light-emitting and receiving element (also referred to as a light-emitting and receiving device) and a light-emitting element.

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

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

[0147] In a light-receiving device of one embodiment of the present invention, when light emitted by a light-emitting element in the light-receiving unit is reflected (or scattered) by an object, the light-receiving element can detect the reflected light (or scattered light). This makes it possible to capture images or detect touch operations even in dark places.

[0148] The light-emitting element included in the light-receiving and light-emitting device of one embodiment 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 called an EL device) such as an OLED or a QLED. Examples of light-emitting substances that the EL element has 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). Also, an LED such as a micro LED can be used as the light-emitting element.

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

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

[0152] An electronic device to which the light-emitting and receiving device of one embodiment of the present invention is applied can acquire data related to biometric information such as a fingerprint or palm print by using a function as an image sensor. That is, a biometric authentication sensor can be built into the light-emitting and receiving device. By building in the biometric authentication sensor in the light-emitting and receiving device, the number of components of the electronic device can be reduced compared to a case in which a biometric authentication sensor is provided separately from the light-emitting and receiving device, and the electronic device can be made smaller and lighter.

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

[0154] The light receiving element may be, for example, a pn-type or pin-type photodiode. The light receiving element functions as a photoelectric conversion element (also called a photoelectric conversion device) that detects light incident on the light receiving element and generates electric charge. The amount of electric charge generated by the light receiving element is determined based on the amount of light incident on the light receiving element.

[0155] In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light receiving element. Organic photodiodes can be easily made thin, lightweight, and large in area, and have a high degree of freedom in shape and design, making them applicable to a variety of devices.

[0156] In one embodiment of the present invention, an organic EL element (also called an organic EL device) is used as a light-emitting element, and an organic photodiode is used as a light-receiving element. The organic EL element and the organic photodiode can be formed on the same substrate. Therefore, the organic photodiode can be built into a display device using the organic EL element.

[0157] When all layers constituting an organic EL element and an organic photodiode are fabricated separately, the number of film formation steps becomes enormous. However, since many layers of an organic photodiode can be made common to an organic EL element, the layers that can be made common can be formed at the same time, which makes it possible to suppress the increase in the number of film formation steps.

[0158] For example, one of the pair of electrodes (common electrode) can be a layer common to the light receiving element and the light emitting element. Also, for example, at least one of the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer is preferably a layer common to the light receiving element and the light emitting element. Also, for example, the light receiving element and the light emitting element can have the same configuration except that the light receiving element has an active layer and the light emitting element has a light emitting layer. That is, the light receiving element can be manufactured by simply replacing the light emitting layer of the light emitting element with the active layer. In this way, by the light receiving element and the light emitting element having a common layer, the number of film formations 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 by using an existing manufacturing apparatus and manufacturing method for a display device.

[0159] In addition, the layer 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, the 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. In addition, the layer 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 emitting / receiving device having a light emitting / receiving element and a light emitting / receiving device having a light emitting element will be described. Note that the description of the same functions, actions, effects, etc. as those described above may be omitted.

[0161] In the light-receiving and light-emitting device of one embodiment of the present invention, the subpixels that exhibit one of the colors have a light-receiving and light-emitting element instead of a light-emitting element, and the subpixels that exhibit the other colors have a light-emitting element. The light-receiving and light-emitting element have both a function of emitting light (light-emitting function) and a function of receiving light (light-receiving function). For example, when a pixel has three subpixels, a red subpixel, a green subpixel, and a blue subpixel, at least one subpixel has a light-receiving and light-emitting element, and the other subpixels have light-emitting elements. Therefore, the light-receiving and light-emitting portion of the light-receiving and light-emitting device of one embodiment of the present invention has a function of displaying an image using both the light-receiving and light-emitting element and the light-emitting element.

[0162] By using a light-receiving / light-emitting element as both 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. This allows one or both of an imaging function and a sensing function to be added to the light-receiving / light-emitting portion of the light-receiving / light-emitting device while maintaining the aperture ratio of the pixel (aperture ratio of each sub-pixel) and the definition of the light-receiving / light-emitting device. Therefore, the light-receiving / light-emitting device of one embodiment of the present invention can have a higher aperture ratio of the pixel and can easily achieve higher definition, compared to a case in which a sub-pixel having a light-receiving element is provided in addition to a sub-pixel having a light-emitting element.

[0163] In the light-receiving and light-emitting device of one embodiment of the present invention, light-receiving and light-emitting elements and light-emitting elements are arranged in a matrix in a light-receiving and light-emitting portion, and an image can be displayed in the light-receiving and light-emitting portion. The light-receiving and light-emitting portion can be used for an image sensor, a touch sensor, or the like. In the light-receiving and light-emitting device of one embodiment of the present invention, the light-emitting element can be used as a light source for the sensor. Therefore, imaging and detection of a touch operation can be performed even in a dark place.

[0164] The light-receiving and light-emitting element can be fabricated by combining an organic EL element and an organic photodiode. For example, the light-receiving and light-emitting element can be fabricated by adding an active layer of an organic photodiode to the layered structure of an organic EL element. Furthermore, the light-receiving and light-emitting element fabricated by combining an organic EL element and an organic photodiode can suppress an increase in the number of film formation steps by forming layers that can be configured in common with the organic EL element in a single step.

[0165] For example, one of the pair of electrodes (common electrode) can be a layer common to the light-receiving and light-emitting elements and the light-emitting elements. In addition, 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 layer common to the light-receiving and light-emitting elements and the light-emitting elements. In addition, the light-receiving and light-emitting elements and the light-emitting elements can have the same configuration, except for the presence or absence of the active layer of the light-receiving element. In other words, the light-receiving and light-emitting elements can be manufactured by simply adding the active layer of the light-receiving element to the light-emitting element. In this way, by having the light-receiving and light-emitting elements and the light-emitting elements having a common layer, the number of film formations and the number of masks can be reduced, and the manufacturing process and manufacturing cost of the light-receiving and light-emitting device can be reduced. In addition, a light-receiving and light-emitting device having a light-receiving and light-emitting element can be manufactured by using an existing manufacturing apparatus and manufacturing method for a display device.

[0166] In addition, the layers of the light emitting / receiving element may have different functions depending on whether the light emitting / receiving element functions as a light receiving element or a light emitting element. In this specification, components are referred to based on their functions when the light emitting / receiving element functions as a light emitting element.

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

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

[0169] When the light emitting / receiving element is used as an image sensor, the light emitting / receiving device of the present embodiment can capture an image using the light emitting / receiving element. When the light emitting / receiving element is used as a touch sensor, the light emitting / receiving device of the present embodiment can detect a touch operation of an object using the light emitting / receiving element.

[0170] The light-receiving and light-emitting element functions as a photoelectric conversion element. The light-receiving and light-emitting element can be fabricated by adding an active layer of a light-receiving element to the configuration of the light-emitting element described above. For example, the active layer of a pn-type or pin-type photodiode can be used for the light-receiving and light-emitting element.

[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-receiving / light-emitting element. Organic photodiodes can be easily made thin, lightweight, and large in area, and have a high degree of freedom in shape and design, making them applicable to a variety of devices.

[0172] A display device, which is an example of a light-emitting and receiving device according to one embodiment of the present invention, will be described in more detail below with reference to the drawings.

[0173] [Display device configuration example 1] [Configuration Example 1-1] 8A shows a schematic diagram of a display panel 200. The display panel 200 has 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), and blue (B) light, respectively. Note that hereinafter, when there is no need to distinguish between the light-emitting element 211R, the light-emitting element 211G, and the light-emitting element 211B, 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. Each pixel has one or more sub-pixels. Each sub-pixel has one light-emitting element. For example, a pixel may have three sub-pixels (three colors: R, G, and B, or three colors: yellow (Y), cyan (C), and magenta (M)) or four sub-pixels (four colors: R, G, B, and white (W), or four colors: R, G, B, and Y). Each pixel further 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] 8A shows a state in which finger 220 touches the surface of substrate 202. A part of the light emitted by light emitting element 211G is reflected at the contact portion between substrate 202 and finger 220. Then, a part of the reflected light is incident on light receiving element 212, so that it is possible to detect that finger 220 has touched substrate 202. In other words, display panel 200 can function as a touch panel.

[0177] The functional layer 203 has a circuit for driving the light emitting element 211R, the light emitting element 211G, and the light emitting element 211B, and a circuit for driving the light receiving element 212. The functional layer 203 is provided with switches, transistors, capacitance, wiring, and the like. Note that when the light emitting element 211R, the light emitting element 211G, the light emitting element 211B, and the light receiving element 212 are driven by a passive matrix method, a configuration without providing switches, transistors, and the like may be adopted.

[0178] It is preferable that the display panel 200 has a function for detecting a fingerprint of a finger 220. Fig. 8B is a schematic enlarged view of a contact portion when the finger 220 is touching the substrate 202. Fig. 8B also shows light emitting elements 211 and light receiving elements 212 arranged alternately.

[0179] A fingerprint is formed by concave and convex parts of finger 220. Therefore, the convex parts of the fingerprint are in contact with substrate 202 as shown in FIG.

[0180] Light reflected from a surface, interface, etc. can be classified as specular reflection or diffuse reflection. Specular reflection is highly directional light in which the angle of incidence and the angle of reflection are the same, while diffuse reflection is low-directional light in which the intensity is less dependent on the angle. The light reflected from the surface of finger 220 is dominated by the diffuse reflection component of specular reflection and diffuse reflection. On the other hand, the light reflected from the interface between substrate 202 and the atmosphere is dominated by the specular reflection component.

[0181] The intensity of light reflected by the contact or non-contact surface between finger 220 and substrate 202 and incident on light receiving element 212 located directly below them is the sum of specularly reflected light and diffusely reflected light. As described above, at the concave portions of finger 220, substrate 202 and finger 220 do not come into contact with each other, so specularly reflected light (indicated by solid arrows) is dominant, whereas at the convex portions, they come into contact with each other, so diffusely reflected light (indicated by dashed arrows) from finger 220 is dominant. Therefore, the intensity of light received by light receiving element 212 located directly below the concave portions is higher than that of light receiving element 212 located directly below the convex portions. This makes it possible to capture an image of the fingerprint of finger 220.

[0182] A clear fingerprint image can be obtained by setting the arrangement interval of the light receiving elements 212 to an interval smaller than the distance between two convex parts of a fingerprint, preferably the distance between adjacent convex parts and concave parts. Since the distance between convex parts and concave parts 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, even more preferably 100 μm or less, and even more preferably 50 μm or less, and is 1 μm or more, preferably 10 μm or more, and more preferably 20 μm or more.

[0183] Fig. 8C shows an example of a fingerprint image captured by display panel 200. In Fig. 8C, the outline of finger 220 is shown by a dashed line and the outline of contact portion 221 is shown by a dashed line within imaging range 223. Within contact portion 221, a fingerprint 222 with high contrast can be captured due to differences in the amount of light incident on light receiving element 212.

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

[0185] As shown in FIG. 8D, the diffuse reflected light scattered by the tip of stylus 225 and the contact surface of substrate 202 is incident on light receiving element 212 located at the portion overlapping with the contact surface, thereby enabling the position of the tip of stylus 225 to be detected with high accuracy.

[0186] 8E shows an example of a trajectory 226 of the stylus 225 detected by the display panel 200. The display panel 200 is capable of detecting the position of a detectable object such as the stylus 225 with high positional accuracy, and therefore is also capable of performing high-definition drawing in a drawing application or the like. Also, unlike the case where a capacitive touch sensor, an electromagnetic induction touch pen, or the like is used, the position of even a highly insulating detectable object can be detected, so the material of the tip of the stylus 225 is not limited, and various writing implements (for example, a brush, a glass pen, a feather pen, etc.) can be used.

[0187] Here, an example of a pixel applicable to the display panel 200 is shown in FIG. 8F to FIG. 8H.

[0188] 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. The pixel each have 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.

[0189] Fig. 8F is an example in which three light emitting elements and one light receiving element are arranged in a 2 x 2 matrix. Fig. 8G is an example in which three light emitting elements are arranged in a row, and one horizontally long 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] The pixel configuration is not limited to the above, and various arrangement methods can be adopted.

[0192] [Configuration Example 1-2] In the following, an example of a configuration including a light-emitting element that emits visible light, a light-emitting element that emits infrared light, and a light-receiving element will be described.

[0193] The display panel 200A shown in Fig. 9A has a light-emitting element 211IR in addition to the configuration exemplified in Fig. 8A. The light-emitting element 211IR is a light-emitting element that emits infrared light IR. In this case, it is preferable to use an element that can receive at least the infrared light IR emitted by the light-emitting element 211IR as the light-receiving element 212. It is more preferable to use an element that can receive both visible light and infrared light as the light-receiving element 212.

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

[0195] 9B to 9D show an example of a pixel that can be applied to the display panel 200A.

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

[0197] FIG. 9D shows an example in which three light emitting elements and a light receiving element 212 are arranged on all four sides with a light emitting element 211IR at the center.

[0198] In the pixels shown in FIGS. 9B to 9D, the positions of the light-emitting elements and the light-emitting elements and the light-receiving elements can be interchanged.

[0199] [Configuration Example 1-3] In the following, an example of a configuration including a light-emitting element that emits visible light and a light-receiving / light-emitting element that emits visible light and receives visible light will be described.

[0200] The display panel 200B shown in Fig. 10A has a light emitting element 211B, a light emitting element 211G, and a light receiving / emitting element 213R. The light receiving / emitting 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 receiving / emitting element 213R receives green (G) light emitted by the light emitting element 211G. The light receiving / emitting element 213R may receive blue (B) light emitted by the light emitting element 211B. The light receiving / emitting element 213R may receive both green light and blue light.

[0201] For example, it is preferable that the light receiving / emitting element 213R receives light having a shorter wavelength than the light it emits. Alternatively, the light receiving / emitting element 213R may be configured to receive light having a longer wavelength than the light it emits (e.g., infrared light). The light receiving / emitting element 213R may be configured to receive light having a wavelength similar to that of the light it emits, but in that case, it may receive the light it emits itself, which may reduce the light emission efficiency. Therefore, it is preferable that the light receiving / emitting element 213R is configured so that the peak of the emission spectrum and the peak of the absorption spectrum do not overlap as much as possible.

[0202] In addition, the light emitted by the light receiving / emitting element is not limited to red light. The light emitted by the light emitting element is not limited to a combination of green light and blue light. For example, the light receiving / emitting element may be an element that emits green or blue light and receives light of a wavelength different from the light it emits.

[0203] In this way, by making the light receiving / receiving element 213R function as both a light emitting element and a light receiving element, the number of elements arranged in one pixel can be reduced, which facilitates achieving higher definition, a higher aperture ratio, and higher resolution.

[0204] 10B to 10I show an example of a pixel that can be applied to the display panel 200B.

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

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

[0207] FIG. 10E shows two pixels. An 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 / 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 / emitting element 213R, and the light emitting element 211B is arranged in the same column as the light receiving / 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 / emitting element 213R, and the light emitting element 211B is arranged in the same column as the light receiving / emitting element 211G. In the pixel layout shown in FIG. 10E, the light receiving / emitting element 213R, the light emitting element 211G, and the light emitting element 211B are arranged repeatedly in both odd and even rows, and in each column, light emitting elements or light receiving / emitting elements of different colors are arranged in the odd and even rows.

[0208] Fig. 10F shows four pixels to which a Pentile array is applied, and two adjacent pixels have light emitting or light receiving / emitting elements that emit light of two different colors. Note that Fig. 10F shows the top shape of the light emitting or light receiving / emitting element.

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

[0210] The top surface shape of the light-emitting element and the light-receiving element is not particularly limited, and may be a circle, an ellipse, a polygon, a polygon with rounded corners, etc. In Fig. 10F and the like, an example is shown in which the top surface shape of the light-emitting element and the light-receiving element is a square (diamond) tilted at approximately 45 degrees. Note that the top surface shapes of the light-emitting element and the light-receiving element for each color may be different from each other, or may be the same for some or all of the colors.

[0211] In addition, the sizes of the light-emitting regions (or light-receiving and light-emitting regions) of the light-emitting elements and 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 smaller than the light-emitting regions (or light-receiving and light-emitting regions) of the other elements.

[0212] Fig. 10G is a modified example of the pixel array shown in Fig. 10F. Specifically, the configuration of Fig. 10G is obtained by rotating the configuration of Fig. 10F by 45 degrees. Although Fig. 10F has been described as having two elements in one pixel, it can also be considered that one pixel is composed of four elements as shown in Fig. 10G.

[0213] Fig. 10H is a modified example of the pixel array shown in Fig. 10F. The upper left pixel and the lower right pixel shown in Fig. 10H have a light emitting / receiving element 213R and a light emitting element 211G. The upper right pixel and the lower left pixel have a light emitting / receiving element 213R and a light emitting element 211B. That is, in the example shown in Fig. 10H, each pixel is provided with a light emitting / receiving element 213R. Since each pixel is provided with a light emitting / receiving element 213R, the configuration shown in Fig. 10H can capture images with higher resolution than the configuration shown in Fig. 10F. This can improve the accuracy of biometric authentication, for example.

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

[0215] In FIG. 10I, a description will be given assuming that one pixel is composed of four elements (two light emitting elements and two light receiving / emitting elements). In this way, one pixel has a plurality of light receiving / emitting elements having a light receiving function, so that it is possible to capture an image with high resolution. This makes it possible to improve the accuracy of biometric authentication. For example, the resolution of the image can be set to the root of twice the resolution of the display.

[0216] A display device to which the configuration shown in Figure 10H or Figure 10I is applied has p (p is an integer of 2 or more) first light-emitting elements, q (q is an integer of 2 or more) second light-emitting elements, and r (r is an integer greater than p and greater than q) light-receiving and light-emitting elements. p and r satisfy r = 2p. Furthermore, p, q, and r satisfy r = p + q. One of the first light-emitting elements and the second light-emitting elements 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 a light receiving / emitting element, it is preferable that the light emitted from the light source is difficult for the user to see. Since blue light is less visible than green light, it is preferable to use a light emitting element that emits blue light as the light source. Therefore, it is preferable that the light receiving / emitting element has a function of receiving blue light. However, this is not limited to this, and a light emitting element to be used as the light source can be appropriately selected depending on the sensitivity of the light receiving / emitting element.

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

[0219] [Device structure] Next, detailed structures of a light-emitting element, a light-receiving element, and a light-receiving and light-emitting element that can be used in the display device of one embodiment of the present invention will be described.

[0220] The display device of one embodiment of the present invention may be any of a top emission type that emits light in a direction opposite to a substrate on which a light-emitting element is formed, a bottom emission type that emits light toward the substrate on which a light-emitting element is formed, and a dual emission type that emits light to both sides.

[0221] In this 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 (light-emitting elements, light-emitting layers, etc.), when describing matters common to each element, the alphabet will be omitted. For example, when describing matters common to the light-emitting layer 283R and the light-emitting layer 283G, etc., the light-emitting layer 283 may be written as "light-emitting layer 283."

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

[0224] Each light-emitting element has 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, which are stacked in this order. The light-emitting element 270R has a light-emitting layer 283R, the light-emitting element 270G has a light-emitting layer 283G, and the light-emitting element 270B has a light-emitting layer 283B. The light-emitting layer 283R has a light-emitting material that emits red light, the light-emitting layer 283G has a light-emitting material that emits green light, and the light-emitting layer 283B has a light-emitting material that emits blue light.

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

[0226] The light receiving element 270PD has a pixel electrode 271, a hole injection layer 281, a hole transport layer 282, an active layer 273, an electron transport layer 284, an electron injection layer 285, and a common electrode 275 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 the present embodiment, in both the light-emitting element and the light-receiving element, the pixel electrode 271 functions as an anode, and the common electrode 275 functions as a cathode. In other words, the light-receiving element detects light incident on the light-receiving element, generates charges, and extracts them as a current by applying a reverse bias between the pixel electrode 271 and the common electrode 275 and driving the light-receiving element.

[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 layers of the light receiving element 270PD other than the active layer 273 can be configured in common with the light emitting element. Therefore, the light receiving element 270PD can be formed in parallel with the formation of the light emitting element by simply adding a process of forming the active layer 273 to the manufacturing process of the light emitting element. In addition, the light emitting element and the light receiving element 270PD can be formed on the same substrate. Therefore, the light receiving element 270PD can be built into the 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 a common configuration, except that the active layer 273 of the light receiving element 270PD and the light emitting layer 283 of the light emitting element are separately manufactured. However, the configuration of the light receiving element 270PD and the light emitting element is not limited to this. The light receiving element 270PD and the light emitting element may have layers that are separately manufactured from each other, in addition to the active layer 273 and the light emitting layer 283. It is preferable that the light receiving element 270PD and the light emitting element have one or more layers that are used in common (common layers). This allows the light receiving element 270PD to be built into the display device without significantly increasing the number of manufacturing steps.

[0231] A conductive film that transmits visible light is used for the electrode from which light is extracted, between the pixel electrode 271 and the common electrode 275. In addition, it is preferable to use a conductive film that reflects visible light for the electrode from which light is not extracted.

[0232] It is preferable that a micro-optical resonator (microcavity) structure is applied to the light-emitting element of the display device of this embodiment. Therefore, it is preferable that one of a pair of electrodes of the light-emitting element has an electrode (semi-transmissive / semi-reflective electrode) that is transparent and reflective to visible light, and the other has an electrode (reflective electrode) that is reflective to visible light. When the light-emitting element has a microcavity structure, 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 strengthened.

[0233] The semi-transmissive / semi-reflective electrode may have a laminated structure of a reflective electrode and an electrode that is transparent to visible light (also called a transparent electrode).

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

[0235] The light-emitting element has at least a light-emitting layer 283. The light-emitting element may further have, as a layer other than the light-emitting layer 283, 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, a bipolar substance (a substance with high electron-transport properties and high hole-transport properties), or the like.

[0236] For example, the light-emitting element and the light-receiving element may have one or more layers of the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer in common. Also, the light-emitting element and the light-receiving element may have one or more layers of the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer formed differently from each other.

[0237] The hole injection layer is a layer that injects holes from the anode to the hole transport layer and contains a material with high hole injection properties. Examples of the material with high hole injection properties include a composite material containing a hole transport material and an acceptor material (electron accepting material), an aromatic amine compound, and the like.

[0238] In a light-emitting element, the hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light-emitting layer. In a light-receiving element, the hole transport layer is a layer that transports holes generated in the active layer based on incident light to the anode. The hole transport layer is a layer that contains a hole transport material. The hole transport material is a 1×10 -6 cm 2 A material having a hole mobility of 100 / Vs or more is preferable. Note that other materials can also be used as long as they have a higher hole transporting property than electron transporting property. As the hole transporting material, a material having a high hole transporting property such as a π-electron-rich heteroaromatic compound (e.g., a carbazole derivative, a thiophene derivative, a furan derivative, etc.) or an aromatic amine (a compound having an aromatic amine skeleton) is preferable.

[0239] In the light-emitting element, the electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light-emitting layer. In the light-receiving element, the electron transport layer is a layer that transports electrons generated in the active layer based on incident light to the cathode. The electron transport layer is a layer that contains an electron transporting material. The electron transporting material is, for example, 1×10 -6 cm 2A substance having an electron mobility of 100 / Vs or more is preferable. Note that, other substances may be used as long as they have a higher electron transporting property than holes. As the electron transporting material, a metal complex having a quinoline skeleton, a metal complex having a benzoquinoline skeleton, a metal complex having an oxazole skeleton, a metal complex having a thiazole skeleton, and the like, as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other materials having a high electron transporting property such as π-electron deficient heteroaromatic compounds including nitrogen-containing heteroaromatic compounds may be used.

[0240] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer, and is a layer that contains 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 donor 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 types of light-emitting substances. As the light-emitting substance, a substance that emits light of a color such as blue, purple, blue-purple, green, yellow-green, yellow, orange, or red is appropriately used. In addition, a substance that emits near-infrared light can also be used as the light-emitting substance.

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

[0243] Examples of fluorescent materials include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives.

[0244] Examples of phosphorescent materials include organometallic complexes (particularly iridium complexes) having a 4H-triazole skeleton, 1H-triazole skeleton, imidazole skeleton, pyrimidine skeleton, pyrazine skeleton, or pyridine skeleton, organometallic complexes (particularly iridium complexes) having a phenylpyridine derivative having an electron-withdrawing group as a ligand, platinum complexes, and rare earth metal complexes.

[0245] The light-emitting layer 283 may contain one or more organic compounds (host materials, assist materials, etc.) in addition to a light-emitting substance (guest material). As the one or more organic compounds, one or both of a hole transport material and an electron transport material may be used. In addition, as the one or more organic compounds, a bipolar material or a TADF material may be used.

[0246] The light-emitting layer 283 preferably includes, for example, a phosphorescent material, and a hole-transporting material and an electron-transporting material that are a combination that easily forms an exciplex. With this configuration, light emission using ExTET (Exciplex-Triplet Energy Transfer), which is energy transfer from an exciplex to a light-emitting material (phosphorescent material), can be efficiently obtained. By selecting a combination that forms an exciplex that emits light that overlaps with the wavelength of the lowest energy absorption band of the light-emitting material, energy transfer becomes smooth and light emission can be efficiently obtained. With this configuration, high efficiency, low voltage operation, and long life of the light-emitting element can be simultaneously achieved.

[0247] As a combination of materials that form an exciplex, it is preferable that the HOMO level (highest occupied molecular orbital level) of the hole transporting material is equal to or higher than the HOMO level of the electron transporting material. It is preferable that the LUMO level (lowest unoccupied molecular orbital level) of the hole transporting material is equal to or higher than the LUMO level of the electron transporting material. The LUMO level and HOMO level of the material can be derived from the electrochemical properties (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 spectrum of a hole transport material, the emission spectrum of an electron transport material, and the emission spectrum of a mixed film obtained by mixing these materials, and observing the phenomenon that the emission spectrum of the mixed film shifts to a longer wavelength than the emission spectrum of each material (or has a new peak on the longer wavelength side). Alternatively, it can be confirmed by comparing the transient photoluminescence (PL) of a hole transport material, the transient PL of an electron transport material, and the transient PL of a mixed film obtained by mixing these materials, and observing the difference in transient response, such as the transient PL lifetime of the mixed film having a longer lifetime component than the transient PL lifetime of each material, or the proportion of delayed components becoming larger. In addition, the above-mentioned transient PL may be read as transient electroluminescence (EL). In other words, the formation of an exciplex can also be confirmed by comparing the transient EL of a hole transport material, the transient EL of a material having electron transport properties, and the transient EL of a mixed film obtained by mixing these materials, and observing the difference in transient response.

[0249] The active layer 273 includes a semiconductor. Examples of the semiconductor include an inorganic semiconductor such as silicon, and an organic semiconductor including an organic compound. In this embodiment, an example in which an organic semiconductor is used as the semiconductor of 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, a vacuum deposition method), which is preferable because a common manufacturing device can be used.

[0250] The active layer 273 is made of an n-type semiconductor material such as fullerene (e.g., C 60 , C 70Examples of electron-accepting organic semiconductor materials include organic semiconductor materials such as fullerene derivatives, etc. Fullerenes have a shape like a soccer ball, and this shape is energetically stable. Fullerenes have deep (low) HOMO and LUMO levels. Fullerenes have extremely high electron-accepting (acceptor) properties because of their deep LUMO level. Normally, when π-electron conjugation (resonance) spreads on a plane, as in benzene, electron-donating (donor) properties are high, but fullerenes have a spherical shape, so they have high electron-accepting properties despite the large spread of π-electrons. High electron-accepting properties are useful as light-receiving elements because they cause charge separation quickly and efficiently. C 60 , C 70 Both have a wide absorption band in the visible light region, especially C 70 is C 60 It is preferred because it has a larger π-electron conjugated system and a broad absorption band in the long wavelength region as compared to the above.

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

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

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

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

[0255] It is preferable to use a spherical fullerene as the electron-accepting organic semiconductor material, and an organic semiconductor material with a nearly planar shape as the electron-donating organic semiconductor material. Molecules with similar shapes tend to gather together, and when molecules of the same type aggregate, the energy levels of the molecular orbitals are close to each other, which can increase the carrier transportability.

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

[0257] The light-emitting element and the light-receiving element may be made of either a low molecular weight compound or a high molecular weight compound, and may contain an inorganic compound. The layers constituting the light-emitting element and the light-receiving element may be formed by a deposition method (including a vacuum deposition method), a transfer method, a printing method, an inkjet method, a coating method, or the like.

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

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

[0260] Here, it is preferable that the light receiving element 270PD has a common configuration with the light emitting element that emits light of 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 into a common structure, the number of film forming steps and the number of masks can be reduced compared to a structure in which the light receiving element 270PD and the light emitting element 270R have layers that are separately manufactured, and therefore the manufacturing steps and manufacturing costs of the display device can be reduced.

[0262] In addition, by making the light receiving element 270PD and the light emitting element 270R into a common configuration, the margin for misalignment can be narrowed compared to a configuration in which the light receiving element 270PD and the light emitting element 270R have layers that are made separately from each other. This makes it possible to increase the aperture ratio of the pixel and increase the light extraction efficiency of the display device. This makes it possible to extend the life of the light emitting element. In addition, the display device can express high brightness. In addition, it is also possible to increase the resolution of the display device.

[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 (for example, one or both of green light and blue light). It is preferable that the active layer 273 has an organic compound that does not easily absorb red light and absorbs light with a shorter wavelength than red. This allows the light-emitting element 270R to efficiently extract red light, and the light-receiving element 270PD to detect light with a shorter wavelength than red with high accuracy.

[0264] Furthermore, in the display device 280B, an example is shown in which the light emitting element 270R and the light receiving element 270PD have the same configuration, but the light emitting element 270R and the light receiving element 270PD may have optical adjustment layers of different thicknesses.

[0265] 12A and 12B includes a light receiving / emitting element 270SR that emits red (R) light and has a light receiving function, a light emitting element 270G, and a light emitting element 270B. The configuration of the light emitting element 270G and the light emitting element 270B can be the same as that of the display device 280A described above.

[0266] The light receiving / emitting 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 receiving / emitting element 270SR has the same configuration as the light emitting element 270R and the light receiving element 270PD exemplified in the display device 280B.

[0267] Fig. 12A shows a case where the light emitting / receiving element 270SR functions as a light emitting element. Fig. 12A shows an example where the light emitting element 270B emits blue light, the light emitting element 270G emits green light, and the light emitting / receiving element 270SR emits red light.

[0268] Fig. 12B shows a case where the light receiving / emitting element 270SR functions as a light receiving element. Fig. 12B shows an example where the light receiving / emitting element 270SR receives blue light emitted by the light emitting element 270B and green light emitted by the light emitting element 270G.

[0269] The light emitting element 270B, the light emitting element 270G, and the light receiving / emitting element 270SR each have a pixel electrode 271 and a common electrode 275. In this embodiment, a case will be described in which the pixel electrode 271 functions as an anode and the common electrode 275 functions as a cathode. The light receiving / emitting element 270SR is driven by applying a reverse bias between the pixel electrode 271 and the common electrode 275, so that the light receiving / emitting element 270SR can detect light incident on the light receiving / emitting element 270SR, generate electric charges, and extract the electric charges as a current.

[0270] The light emitting / receiving element 270SR can be said to have a configuration in which the active layer 273 is added to the light emitting element. In other words, the light emitting / receiving element 270SR can be formed in parallel with the formation of the light emitting element by simply adding a process of forming the active layer 273 to the manufacturing process of the light emitting element. In addition, the light emitting element and the light emitting / receiving element can be formed on the same substrate. Therefore, it is possible to impart one or both of an imaging function and a sensing function to the display unit without significantly increasing the manufacturing process.

[0271] There is no limitation on the stacking order of the light emitting layer 283R and the active layer 273. Figures 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 stacking order of the light emitting layer 283R and the active layer 273 may be reversed.

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

[0273] In the light receiving / emitting element, a conductive film that transmits visible light is used for the electrode from which light is extracted, and a conductive film that reflects visible light is preferably used for the electrode from which light is not extracted.

[0274] The functions and materials of the layers constituting the light emitting / receiving element are similar to those of the layers constituting the light emitting element and the light receiving element, and therefore detailed description thereof will be omitted.

[0275] 12C to 12G show examples of the layered structure of the light emitting / receiving element.

[0276] The light emitting / 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 shows an example in which a light-emitting layer 283R is provided on a hole-transporting layer 282, and an active layer 273 is laminated on the light-emitting layer 283R.

[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] In addition, a buffer layer is preferably provided between the active layer 273 and the light-emitting layer 283R. In this case, the buffer layer preferably has hole transport properties and electron transport properties. For example, a bipolar substance is preferably used for the buffer layer. Alternatively, at least one layer selected from a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole blocking layer, and an electron blocking layer can be used as the buffer layer. FIG. 12D shows an example in which a 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. In addition, the buffer layer can be used to adjust the optical path length (cavity length) of the microcavity structure. Therefore, a light emitting / receiving element having a buffer layer between the active layer 273 and the light emitting layer 283R can obtain high light emitting efficiency.

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

[0282] 12F differs from the light emitting / receiving element shown in Fig. 12A in that it does not have the hole transport layer 282. In this manner, the light emitting / receiving element may not have at least one layer among the hole injection layer 281, the hole transport layer 282, the electron transport layer 284, and the electron injection layer 285. The light emitting / receiving element may also have other functional layers, such as a hole blocking layer or an electron blocking layer.

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

[0284] As a layer serving as both a light-emitting layer and an active layer, for example, a layer containing three materials: 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] Furthermore, it is preferable that the absorption band on the lowest energy side of the absorption spectrum of the mixed material of n-type semiconductor and p-type semiconductor does not overlap with the maximum peak of the emission spectrum (PL spectrum) of the luminescent substance, and it is more preferable that they are sufficiently separated from each other.

[0286] [Display device configuration example 2] A detailed structure of a display device according to one embodiment of the present invention will be described below. In particular, an example of a display device including a light-receiving element and a light-emitting element will be described.

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

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

[0289] The light receiving element 310 has a pixel electrode 311, a buffer layer 312, an active layer 313, a buffer layer 314, and a common electrode 315 stacked in this order. The active layer 313 contains an organic compound. The light receiving element 310 has a function of detecting visible light. The light receiving element 310 may 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 them. The buffer layer 312, the buffer layer 314, and the common electrode 315 have portions overlapping with the active layer 313 and the pixel electrode 311, portions overlapping with the light emitting layer 393 and the pixel electrode 391, and portions not overlapping with either.

[0291] In the present embodiment, it is assumed that the pixel electrode functions as an anode and the common electrode 315 functions as a cathode in both the light emitting element 390 and the light receiving element 310. In other words, by driving the light receiving element 310 by applying a reverse bias between the pixel electrode 311 and the common electrode 315, the display device 300A can detect light incident on the light receiving element 310, generate electric 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 multilayer structure.

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

[0294] An organic insulating film is suitable for the partition 416. Materials that can be used for the organic insulating film include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins. The partition 416 is a layer that transmits visible light. Instead of the partition 416, a partition that blocks visible light may be provided.

[0295] The common electrode 315 is a layer shared by the light receiving element 310 and the light emitting element 390 .

[0296] The materials and thicknesses of the pair of electrodes of the light receiving element 310 and the light emitting element 390 can be made the same, which leads to reduction in manufacturing cost and simplification of the manufacturing process of the display device.

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

[0298] In the light receiving element 310, the buffer layer 312, active layer 313, and buffer layer 314 located between the pixel electrode 311 and the common electrode 315 can also be called organic layers (layers containing an organic compound). The pixel electrode 311 preferably has a function of reflecting visible light. The common electrode 315 has a function of transmitting visible light. In addition, when the light receiving element 310 is configured to detect infrared light, the common electrode 315 has a function of transmitting infrared light. Furthermore, the pixel electrode 311 preferably has a function of reflecting infrared light.

[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 light 322 incident from the outside of the display device 300A and converts it into an electrical signal. The light 322 can also be said to be light emitted by the light emitting element 390 and reflected by an object. The light 322 may also be incident on the light receiving element 310 via a lens or the like provided in the display device 300A.

[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 be collectively referred to as an EL layer. The EL layer has at least the light-emitting layer 393. As described above, the pixel electrode 391 preferably has a function of reflecting visible light. Furthermore, the common electrode 315 has a function of transmitting visible light. When the display device 300A has a configuration including a light-emitting element that emits infrared light, the common electrode 315 has a function of transmitting infrared light. Furthermore, the pixel electrode 391 preferably has a function of reflecting infrared light.

[0301] It is preferable that a micro-optical resonator (microcavity) structure is applied to the light-emitting element of the display device of this embodiment. The light-emitting element 390 may have an optical adjustment layer between the pixel electrode 391 and the common electrode 315. By applying the micro-resonator structure, it is possible to enhance and extract light of a specific color from each light-emitting element.

[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) to 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. This allows the thickness of the display device to be thinner and the manufacturing process to be simplified compared to the case where the two circuits are formed separately.

[0306] The light receiving element 310 and the light emitting element 390 are preferably covered with a protective layer 395. In Fig. 13A, the protective layer 395 is provided on and in contact with the common electrode 315. By providing the protective layer 395, it is possible to prevent 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. In addition, the protective layer 395 and the substrate 352 are bonded together by the adhesive layer 342.

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

[0308] Here, the light receiving element 310 detects the light emitted by the light emitting element 390 reflected by the object. However, the light emitted by the light emitting element 390 may be reflected in the display device 300A and may be incident on 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, if the light shielding layer 358 is not provided, the light 323 emitted by the light emitting element 390 may be reflected by the substrate 352, and the reflected light 324 may be incident on the light receiving element 310. By providing the light shielding layer 358, it is possible to suppress the reflected light 324 from being incident on the light receiving element 310. This can reduce noise and increase the sensitivity of the sensor using the light receiving element 310.

[0309] The light-shielding layer 358 may be made of a material that blocks light emitted from the light-emitting element. The light-shielding layer 358 preferably absorbs visible light. For example, the light-shielding layer 358 may be made of a black matrix using a metal material, or a resin material containing a pigment (such as carbon black) or a dye. The light-shielding layer 358 may have a laminated structure of 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 differs from the display device 300A described above mainly in that a lens 349 is provided.

[0311] Lens 349 is provided on the substrate 351 side of substrate 352. Light 322 incident from the outside is incident on light receiving element 310 via lens 349. Lens 349 and substrate 352 are preferably made of a material that is highly transparent to visible light.

[0312] Light is incident on the light receiving element 310 via the lens 349, thereby narrowing the range of light incident on the light receiving element 310. This makes it possible to prevent the imaging ranges of the multiple light receiving elements 310 from overlapping, and to capture a clear image with little blur.

[0313] Furthermore, the lens 349 can condense the incident light, thereby increasing the amount of light incident on the light receiving element 310. This allows the photoelectric conversion efficiency of the light receiving element 310 to be improved.

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

[0315] The light-shielding layer 358 is provided such that an opening overlapping the light-receiving element 310 is located inside the light-receiving region of the light-receiving element 310 in a plan view. The smaller the diameter of the opening of the light-shielding layer 358 overlapping with the light-receiving element 310, the narrower the range of light incident on the light-receiving element 310 can be. This makes it possible to prevent the imaging ranges of the multiple light-receiving elements 310 from overlapping, and to capture a clear image with little blur.

[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 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 decreases, and the light-receiving sensitivity may decrease. Therefore, it is preferable to set it appropriately within the above-mentioned range. The above-mentioned 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] The center of the opening of the light-shielding layer 358 that overlaps with the light-receiving element 310 may be shifted from the center of the light-receiving region of the light-receiving element 310 in a plan view. Furthermore, the opening of the light-shielding layer 358 may not overlap with the light-receiving region of the light-receiving element 310 in a plan view. This allows the light-receiving element 310 to receive only oblique light that has passed through the opening of the light-shielding layer 358. This makes it possible to more effectively limit the range of light incident on the light-receiving element 310, and capture a clear image.

[0318] [Configuration Example 2-4] Display device 300D shown in FIG. 14A differs from display device 300A described above primarily in that buffer layer 312 is not a common layer.

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

[0320] Buffer layer 312 and buffer layer 392 may comprise different materials or the same materials.

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

[0322] [Configuration Example 2-5] Display device 300E shown in FIG. 14B differs from display device 300A above primarily in that buffer layer 314 is not a common layer.

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

[0324] Buffer layer 314 and buffer layer 394 may comprise different materials or the same materials.

[0325] In this way, by separately preparing 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 for the light emitting element 390 and the light receiving element 310 is increased, making optimization easier. Furthermore, by making the buffer layer 312 and the common electrode 315 into 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 separately manufactured.

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

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

[0328] In this way, by separately preparing 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 for the light emitting element 390 and the light receiving element 310 is increased, making optimization easier. Furthermore, by making the common electrode 315 a common layer, the manufacturing process is simplified and manufacturing costs can be reduced compared to the case where the light emitting element 390 and the light receiving element 310 are separately manufactured.

[0329] [Display device configuration example 3] A detailed structure of a display device according to one embodiment of the present invention will be described below. In particular, an example of a display device including a light-emitting element and a light-emitting element will be described.

[0330] In the following, the same parts as those described above will be referred to and explanations thereof may be omitted.

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

[0332] The light emitting / 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 / receiving element 390SR has a pixel electrode 311, a buffer layer 312, an active layer 313, a light emitting layer 393R, a buffer layer 314, and a common electrode 315. The light emitting element 390G has a pixel electrode 391G, a buffer layer 312, a light emitting layer 393G, a buffer layer 314, and a common electrode 315. The light emitting element 390B has a pixel electrode 391B, a buffer layer 312, a light emitting layer 393B, a buffer layer 314, and a common electrode 315.

[0334] The buffer layer 312, the buffer layer 314, and the common electrode 315 are layers (common layers) common to the light emitting / receiving element 390SR, the light emitting element 390G, and the light emitting element 390B, and are provided across these elements. The active layer 313, the light emitting layer 393R, the light emitting layer 393G, and the light emitting layer 393B each have an island-like upper surface shape. Note that, although an example is shown in Fig. 15 in which the stack of the active layer 313 and the light emitting layer 393R, the light emitting layer 393G, and the light emitting layer 393B are provided separately from each other, they may have an area where two adjacent layers overlap each other.

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

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

[0337] With this configuration, a display device with higher resolution can be realized.

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

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

[0340] The light emitting / receiving layer 318R is a layer that functions both as a light emitting layer and an active layer. For example, a layer including the above-mentioned light emitting material, an n-type semiconductor, and a p-type semiconductor can be used.

[0341] With such a structure, the manufacturing process can be further simplified, which facilitates cost reduction.

[0342] [Display device configuration example 4] A more specific structure of the display device of one embodiment of the present invention will be described below.

[0343] FIG. 16 shows a perspective view of display device 400, and FIG. 17A shows a cross-sectional view of 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, 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 said to be a display module including the display device 400, an IC, and an FPC.

[0346] The circuit 364 can be, for example, a scanning line driver circuit.

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

[0348] 16 shows an example in which an IC 373 is provided on a substrate 353 by a chip on glass (COG) method or a chip on film (COF) method. For example, an IC having a scanning line driver circuit or a signal line driver circuit can be used as the IC 373. Note that the display device 400 and the display module may not include an IC. Also, an IC may be mounted on an FPC by a COF method or the like.

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

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

[0351] The substrate 354 and the protective layer 395 are bonded 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 attached to each other by an adhesive layer 355 .

[0353] In the 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, and the like is bonded to a substrate 354 provided with a light blocking layer 358 and the like by an adhesive layer 342. Then, the manufacturing substrate is peeled off, and a substrate 353 is bonded to the exposed surface by using an adhesive layer 355, so that each component formed on the manufacturing substrate is transferred to the substrate 353. Each of the substrate 353 and the substrate 354 is preferably flexible. This can increase the flexibility of the display device 400.

[0354] The light-emitting element 390 has a layered 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 the drain of the transistor 408 through an opening provided in the insulating layer 414. The transistor 408 has a function of controlling a current flowing in the light-emitting element 390.

[0355] The light receiving element 310 has a layered 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 layered 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 transfer of charges accumulated in the light receiving element 310.

[0356] Light emitted by the light emitting element 390 is emitted towards the substrate 354. Light is incident on the light receiving element 310 via the substrate 354 and the adhesive layer 342. The substrate 354 is preferably made of a material that is highly transparent to visible light.

[0357] The pixel electrodes 311 and 391 can be manufactured using the same material and in the same process. The buffer layer 312, the buffer layer 314, and the common electrode 315 are used in common 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 for the configurations of the active layer 313 and the light emitting layer 393. This allows the light receiving element 310 to be built into the display device 400 without significantly increasing the number of manufacturing steps.

[0358] A light-shielding layer 358 is provided on the surface of the substrate 354 facing the substrate 353. The light-shielding layer 358 has openings at positions overlapping the light-emitting element 390 and the light-receiving element 310. 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. In addition, by providing the light-shielding layer 358, it is possible to suppress the light from being directly incident on the light-receiving element 310 from the light-emitting element 390 without passing through the object. Therefore, a sensor with low noise and high sensitivity can be realized.

[0359] Ends of the pixel electrode 311 and the pixel electrode 391 are covered with a partition wall 416. The pixel electrode 311 and the pixel electrode 391 include a material that reflects visible light, and the common electrode 315 includes a material that transmits visible light.

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

[0361] A transistor 408, a transistor 409, and a transistor 410 are all formed over a substrate 353. These transistors can be manufactured using the same material and through the same process.

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

[0363] It is preferable that at least one of the insulating layers covering the transistors is made of a material that is difficult for impurities such as water and hydrogen to diffuse into. This allows the insulating layer to function as a barrier layer. With this structure, it is possible to effectively prevent impurities from diffusing into the transistors from the outside, thereby improving the reliability of the display device.

[0364] It is preferable to use an inorganic insulating film for each of the insulating layers 411, 412, 425, 415, and 418. 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, or the like can be used. Alternatively, a hafnium oxide film, a hafnium oxynitride film, a hafnium nitride oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, a neodymium oxide film, or the like may be used. Alternatively, two or more of the above insulating films may be stacked.

[0365] Here, the organic insulating film often has a lower barrier property than the inorganic insulating film. Therefore, it is preferable that the organic insulating film has 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. This makes it possible to suppress impurities from entering from the end of the display device 400 through the organic insulating film. Alternatively, the organic insulating film may be formed so that the end of the organic insulating film is located 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 a region 428 near the end of the display device 400, the insulating layer 418 and the protective layer 395 are preferably in contact with each other through an opening in 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. This makes it possible to suppress impurities from entering the display unit 362 from the outside through the organic insulating film. Therefore, the reliability of the display device 400 can be improved.

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

[0368] By providing protective layer 395 covering light emitting element 390 and light receiving element 310, it is possible to prevent impurities such as water from entering light emitting element 390 and light receiving element 310, thereby improving their reliability.

[0369] The protective layer 395 may have 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. In this case, it is preferable that the end of the inorganic insulating film extends further outward than the end of the organic insulating film.

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

[0371] The transistor 401a is provided over an insulating layer 412 (not shown) and includes a conductive layer 421 functioning as a first gate, an insulating layer 411 functioning as a first gate insulating layer, a semiconductor layer 431, an insulating layer 425 functioning as a second gate insulating layer, and a conductive layer 423 functioning 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 layer 422a and the conductive layer 422b are connected to the region 431n through openings provided in the insulating layer 418 and the insulating layer 415, respectively.

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

[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 inverted staggered transistor, or the like can be used. In addition, either a top-gate type or a bottom-gate type transistor structure may be used. Alternatively, gates may be provided above and below a semiconductor layer in which a channel is formed.

[0375] The transistor 408, the transistor 409, and the transistor 410 have a structure in which a semiconductor layer in which a channel is formed is sandwiched between two gates. The two gates may be connected and supplied with the same signal to drive the transistor. Alternatively, the threshold voltage of the transistor may be controlled by applying a potential for controlling the threshold voltage to one of the two gates and applying a potential for driving to the other.

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

[0377] The semiconductor layer of the transistor preferably contains a metal oxide (also referred to as an oxide semiconductor). Alternatively, the semiconductor layer of the transistor may contain silicon. Examples of silicon include amorphous silicon and crystalline silicon (such as low-temperature polysilicon and single crystal silicon).

[0378] The semiconductor layer preferably contains, 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 referred to 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 atomic ratios of metal elements in such In-M-Zn oxides include In:M:Zn=1:1:1 or a composition thereabout, In:M:Zn=1:1:1.2 or a composition thereabout, In:M:Zn=2:1:3 or a composition thereabout, In:M:Zn=3:1:2 or a composition thereabout, In:M:Zn=4:2:3 or a composition thereabout, In:M:Zn=4:2:4.1 or a composition thereabout, In:M:Zn=5:1:3 or a composition thereabout, In:M:Zn=5:1:6 or a composition thereabout, In:M:Zn=5:1:7 or a composition thereabout, In:M:Zn=5:1:8 or a composition thereabout, In:M:Zn=6:1:6 or a composition thereabout, In:M:Zn=5:2:5 or a composition thereabout, etc. The term "nearby composition" includes a range of ±30% of the desired atomic ratio.

[0381] For example, when describing a composition with an atomic ratio of In:Ga:Zn=4:2:3 or thereabout, it includes the case where, when the atomic ratio of In is 4, 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. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn=5:1:6 or thereabout, it includes the case where, when the atomic ratio of In is 5, the atomic ratio of Ga is more than 0.1 and 2 or less, and the atomic ratio of Zn is 5 or more and 7 or less. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn=1:1:1 or thereabout, it includes the case where, when the atomic ratio of In is 1, the atomic ratio of Ga is more than 0.1 and 2 or less, and the atomic ratio of Zn is more than 0.1 and 2 or less.

[0382] The transistor 410 in the circuit 364 may have the same structure as the transistors 408 and 409 in the display portion 362 or may have different structures. The transistors in the circuit 364 may all have the same structure or may have two or more types. Similarly, the transistors in the display portion 362 may all have the same structure or may have two or more types.

[0383] A connection portion 404 is provided in an area of ​​the substrate 353 where the substrate 354 does not overlap. In the connection portion 404, the wiring 365 is electrically connected to the FPC 372 via a conductive layer 366 and a 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. This allows the connection portion 404 and the FPC 372 to be electrically connected via the connection layer 442.

[0384] Various optical members can be disposed on the outside of the substrate 354. Examples of optical members include a polarizing plate, a retardation plate, a light diffusion layer (such as a diffusion film), an anti-reflection layer, and a light collecting film. In addition, an antistatic film that suppresses adhesion of dust, a water-repellent film that makes it difficult for dirt to adhere, a hard coat film that suppresses the occurrence of scratches due to use, an impact absorbing layer, and the like may be disposed on the outside of the substrate 354.

[0385] The flexibility of the display device can be increased by using a flexible material for the substrate 353 and the substrate 354. In addition, the substrate 353 and the substrate 354 can be made of glass, quartz, ceramic, sapphire, resin, or the like, without being limited thereto.

[0386] As the adhesive layer, various curing adhesives such as a photo-curing adhesive such as an ultraviolet curing adhesive, a reaction curing adhesive, a heat curing adhesive, and an anaerobic adhesive can be used. Examples of such adhesives include epoxy resin, acrylic resin, silicone resin, phenolic resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin, and EVA (ethylene vinyl acetate) resin. In particular, a material with low moisture permeability such as epoxy resin is preferable. A two-liquid mixed resin may also be used. An adhesive sheet or the like may also be used.

[0387] The connection layer may be made of an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0388] Materials that can be used for the gate, source, and drain of a transistor as well as conductive layers such as various wirings and electrodes that constitute a display device include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, as well as alloys containing such metals as main components, etc. Films containing these materials can be used as a single layer or a laminated structure.

[0389] As the conductive material having light transmitting properties, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, or graphene can be used. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, and alloy materials containing the metal materials can be used. Alternatively, nitrides of the metal materials (for example, titanium nitride) and the like may be used. Note that when using metal materials or alloy materials (or their nitrides), it is preferable to make them thin enough to have light transmitting properties. Also, a laminated film of the above materials can be used as the conductive layer. For example, it is preferable to use a laminated film of an alloy of silver and magnesium and indium tin oxide, because it can increase the 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, and the like) of light emitting elements and light receiving elements (or light receiving and light emitting 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 mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification.

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

[0393] FIG. 18A is a block diagram of a pixel of a display device of one embodiment of the present invention.

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

[0395] The light emitted from the OLED is reflected by an object (referred to as "Object"), and the reflected light is received by the OPD, thereby capturing an image of the object. One embodiment of the present invention can function as a touch sensor, an image sensor, an image scanner, or the like. One embodiment of the present invention can be applied to biometric authentication by capturing an image of a fingerprint, palm print, blood vessels (veins, etc.), or the like. In addition, the surface of a printed matter having a photograph, text, or the like written thereon, or an object, can be captured as image information.

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

[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 that resets the potential of the OPD electrodes, an exposure operation that accumulates charge in the OPD according to the amount of irradiated light, a transfer operation that transfers the charge accumulated in the OPD to a node in the sensor circuit, and a read operation that outputs a signal (e.g., voltage or current) according to the magnitude of the charge to an external read circuit as sensing data (referred to as Sensing Data).

[0398] The pixel shown in FIG. 18B differs from the above mainly in that it has a memory section (denoted as "Memory") connected to the drive transistor.

[0399] Weight data (denoted as "Weight Data") is provided to the memory section. Data obtained by adding together the video data input via the selection transistor and the weight data stored in the memory section is provided to the drive transistor. The weight data stored in the memory section can change the brightness of the OLED from the brightness when only video data is provided. Specifically, it is possible to increase or decrease the brightness of the OLED. For example, by increasing the brightness of the OLED, it is possible to increase the light receiving sensitivity of the sensor.

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

[0401] 18C includes a light receiving element PD, a transistor M1, a transistor M2, a transistor M3, a transistor M4, and a capacitor C1. Here, an example is shown in which a photodiode is used as the light receiving element PD.

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

[0403] A constant potential is supplied to the wiring V1, the wiring V2, and the wiring V3. When the light receiving element PD is driven with a 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 of transferring the charge accumulated in the light receiving element PD to the node. The transistor M3 functions as an amplifying transistor that outputs according to the potential of the node. The transistor M4 is controlled by a signal supplied to the wiring SE, and functions as a selection transistor for reading out the output according to the potential of the node to an external circuit connected to the wiring OUT1.

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

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

[0406] 18D includes a light-emitting element EL, a transistor M5, a transistor M6, a transistor M7, and a capacitor C2. Here, an example is shown in which a light-emitting diode is used as the light-emitting element EL. 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 OLED, the transistor M5 corresponds to the selection transistor, and the transistor M6 corresponds to the drive transistor. Also, the wiring VS corresponds to the wiring to which the video data is input.

[0408] The gate of the transistor M5 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. The gate of the transistor M7 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 the wiring V4 and the wiring V5. The anode side of the light-emitting element EL can be set to a high potential, and the cathode side can be set to a lower potential than the anode side. The transistor M5 is controlled by a signal supplied to the wiring VG, and functions as a selection transistor for controlling the selection state of the pixel circuit PIX2. The transistor M6 functions as a drive transistor for controlling the current flowing through the light-emitting element EL according to the potential supplied to the gate. When the transistor M5 is in a conductive state, the potential supplied to the wiring VS is supplied to the gate of the transistor M6, and the light emission luminance of the light-emitting element EL can be controlled according to the potential. The transistor M7 is controlled by a signal supplied to the wiring MS, and has one or both of a function of setting the potential between the transistor M6 and the light-emitting element EL to a potential provided to the wiring OUT2 and a function of outputting the potential between the transistor M6 and the light-emitting element EL to the outside via the wiring OUT2.

[0410] FIG. 18E shows an example of a pixel circuit including a memory unit that can be applied to the configuration shown in FIG. 18B.

[0411] 18E has a configuration in which a transistor M8 and a capacitor C3 are added to the pixel circuit PIX2. In addition, in the pixel circuit PIX3, the line VS in the pixel circuit PIX2 is used as a line VS1, and the line VG is used as a line VG1.

[0412] The transistor M8 has a gate electrically connected to the wiring VG2, one of a source and a drain electrically connected to the wiring VS2, and the other 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 drain of the transistor M5.

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

[0414] An example of an operation method of the pixel circuit PIX3 will be described. First, a first potential is written from the wiring VS1 to a node to which the gate of the transistor M6 is connected via the transistor M5. After that, the transistor M5 is turned off, so that the node is in a floating state. Next, a second potential is written from the wiring VS2 to one electrode of the capacitor C3 via the transistor M8. As a result, the potential of the node changes from the first potential to a third potential in response to the second potential due to the capacitive coupling of the capacitor C3. Then, a current corresponding to the third potential flows through the transistor M6 and the light-emitting element EL, so that the light-emitting element EL emits light with a luminance corresponding to the potential.

[0415] In the display device of the present embodiment, an image may be displayed by making the light-emitting element 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, organic EL elements are preferable because they have excellent frequency characteristics. The frequency may be, for example, 1 kHz or more and 100 MHz or less. Also, a driving method (also called duty driving) in which light is emitted by changing the pulse width may be used.

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

[0417] Alternatively, the transistors M1 to M8 may each be a transistor in which silicon is used as a semiconductor in which a channel is formed. In particular, the use of silicon with high crystallinity, such as single crystal silicon or polycrystalline silicon, is preferable because high field-effect mobility can be achieved and faster operation can be achieved.

[0418] Alternatively, a structure in which an oxide semiconductor is used for at least one of the transistors M1 to M8 and silicon is used for the remaining transistors may be used.

[0419] For example, the transistors M1, M2, M5, M7, and M8, which function as switches for retaining charge, are preferably transistors including an oxide semiconductor and have extremely low off-state current, and one or more of the other transistors may be a transistor including silicon.

[0420] In the pixel circuits PIX1, PIX2, and PIX3, the transistors are represented 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 used.

[0421] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification.

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

[0423] The metal oxide preferably contains at least indium or zinc. In particular, it is preferable that the metal oxide contains indium and zinc. In addition to these, it is preferable that the metal oxide contains aluminum, gallium, yttrium, tin, etc. Furthermore, the metal oxide may contain one or more elements selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, etc.

[0424] Moreover, 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 an oxide semiconductor include amorphous (including completely amorphous), c-axis-aligned crystalline (CAAC), nanocrystalline (nc), cloud-aligned composite (CAC), single crystal, and polycrystal.

[0426] 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 an XRD spectrum obtained by a GIXD (Grazing-Incidence XRD) measurement. The GIXD method is also called the thin film method or the Seemann-Bohlin method.

[0427] For example, in the case of a quartz glass substrate, the peak shape of the XRD spectrum is almost symmetric. On the other hand, in the case of an IGZO film having a crystalline structure, the peak shape of the XRD spectrum is asymmetric. The asymmetric peak shape of the XRD spectrum clearly indicates the presence of crystals in the film or substrate. In other words, if the peak shape of the XRD spectrum is not symmetric, the film or substrate cannot be said to be in an amorphous state.

[0428] The crystal structure of a film or substrate can be evaluated by a diffraction pattern (also called a nanobeam electron diffraction pattern) observed by nanobeam electron diffraction (NBED). For example, a halo is observed in the diffraction pattern of a quartz glass substrate, and it can be confirmed that the quartz glass is in an amorphous state. In addition, a spot-like pattern is observed in the diffraction pattern of an IGZO film formed at room temperature, rather than a halo. For this reason, it is presumed that an IGZO film formed at room temperature is in an intermediate state that is neither crystalline nor amorphous, and therefore it cannot be concluded that it is in an amorphous state.

[0429] <<Structure of oxide semiconductor>> Note that oxide semiconductors may be classified differently from the above when focusing on their structures. For example, oxide semiconductors are classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include the above-mentioned CAAC-OS and nc-OS. Non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, amorphous-like oxide semiconductors (a-like OSs), amorphous oxide semiconductors, and the like.

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

[0431] [CAAC-OS] CAAC-OS is an oxide semiconductor having a plurality of crystalline regions, each of which has a c-axis aligned in a specific direction. The specific direction is the thickness direction of the CAAC-OS film, the normal direction of the surface on which the CAAC-OS film is formed, or the normal direction of the surface of the CAAC-OS film. The crystalline region is a region having periodic atomic arrangement. If the atomic arrangement is considered as a lattice arrangement, the crystalline region is also a region with a uniform lattice arrangement. CAAC-OS has a region in which a plurality of crystalline regions are connected in the ab-plane direction, and the region may have distortion. The distortion refers to a portion in which the direction of the lattice arrangement changes between a region with a uniform lattice arrangement and another region with a uniform lattice arrangement in the region in which the plurality of crystalline regions are connected. In other words, CAAC-OS is an oxide semiconductor having a c-axis aligned and no clear orientation in the ab-plane direction.

[0432] Each of the multiple crystalline regions is composed of one or more minute crystals (crystals with a maximum diameter of less than 10 nm). When a crystalline region is composed of one minute crystal, the maximum diameter of the crystalline region is less than 10 nm. When a crystalline region is composed of many minute crystals, the size of the crystalline region may be about several tens of nm.

[0433] In addition, in an In-M-Zn oxide (wherein element M is one or more elements selected from aluminum, gallium, yttrium, tin, titanium, etc.), the CAAC-OS tends to have a layered crystal structure (also referred to as a layered structure) in which a layer containing indium (In) and oxygen (hereinafter, In layer) and a layer containing element M, zinc (Zn), and oxygen (hereinafter, (M, Zn) layer) are stacked. Note that indium and element M are mutually substituted. Thus, the (M, Zn) layer may contain indium. Also, the In layer may contain element M. Note that the In layer may contain Zn. The layered structure is observed as a lattice image in a high-resolution transmission electron microscope (TEM) image, for example.

[0434] When the CAAC-OS film is subjected to structural analysis using, for example, an XRD device, a peak indicating c-axis orientation is detected at or near 2θ=31° in out-of-plane XRD measurement using θ / 2θ scan. Note that the position of the peak indicating c-axis orientation (2θ value) may vary depending on the type and composition of the metal elements constituting the CAAC-OS.

[0435] For example, a plurality of bright points (spots) are observed in the electron diffraction pattern of the CAAC-OS film, and the two spots are observed at positions symmetrical to each other with respect to the spot of the incident electron beam that has passed through the sample (also called the direct spot).

[0436] When the crystal region is observed from the specific direction, the lattice arrangement in 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. The above distortion may have a lattice arrangement such as a pentagon or heptagon. In addition, in the CAAC-OS, no clear grain boundary can be confirmed even in the vicinity of the distortion. That is, it is found that the formation of grain boundaries is suppressed by the distortion of the lattice arrangement. This is considered to be because the CAAC-OS can tolerate distortion due to the fact that the arrangement of oxygen atoms in the ab-plane direction is not dense and the bond distance between atoms changes due to the substitution of metal atoms.

[0437] A crystal structure in which clear grain boundaries are observed is called a polycrystal. The grain boundaries are likely to become recombination centers and capture carriers, causing a decrease in the on-current of a transistor and a decrease in field effect mobility. Therefore, CAAC-OS in which clear grain boundaries are not observed is one of the crystalline oxides having a crystal structure suitable for a semiconductor layer of a transistor. In order to form a CAAC-OS, a structure containing Zn is preferable. For example, In-Zn oxide and In-Ga-Zn oxide are suitable because they can suppress the occurrence of grain boundaries more than In oxide.

[0438] The CAAC-OS is an oxide semiconductor with high crystallinity and no clear crystal grain boundaries. Therefore, it can be said that the CAAC-OS is less susceptible to a decrease in electron mobility due to crystal grain boundaries. In addition, since the crystallinity of an oxide semiconductor can be decreased by the inclusion of impurities or the generation of defects, the CAAC-OS can be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Therefore, the physical properties of an oxide semiconductor having the CAAC-OS are stable. Therefore, an oxide semiconductor having the CAAC-OS is resistant to heat and has high reliability. In addition, the CAAC-OS is stable against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, the use of the CAAC-OS in an OS transistor can increase the degree of freedom in the manufacturing process.

[0439] [nc-OS] The nc-OS has periodic atomic arrangement in a minute region (for example, a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm). In other words, the nc-OS has minute crystals. Note that the size of the minute crystals is, for example, 1 nm to 10 nm, particularly 1 nm to 3 nm, and therefore the minute crystals are also called nanocrystals. In addition, the nc-OS does not show regularity in the crystal orientation between different nanocrystals. Therefore, no orientation is seen in the entire film. Therefore, the nc-OS may be indistinguishable from an a-like OS and an amorphous oxide semiconductor depending on the analysis method. For example, when a structure analysis is performed on an nc-OS film using an XRD device, no peak indicating crystallinity is detected in out-of-plane XRD measurement using θ / 2θ scan. In addition, when an nc-OS film is subjected to electron diffraction (also called selected area electron diffraction) using an electron beam with a probe diameter larger than that of nanocrystals (for example, 50 nm or more), a diffraction pattern like a halo pattern is observed. On the other hand, when electron diffraction (also called nanobeam electron diffraction) is performed on an nc-OS film using an electron beam with a probe diameter (e.g., 1 nm to 30 nm) that is close to the size of a nanocrystal or smaller than the nanocrystal, an electron diffraction pattern in which multiple spots are observed within a ring-shaped region centered on the direct spot may be obtained.

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

[0441] <<Oxide semiconductor structure>> Next, the above-mentioned CAC-OS will be described in detail, with reference to its material composition.

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

[0443] Furthermore, CAC-OS is a composite metal oxide in which the material is separated into a first region and a second region, forming a mosaic structure, and the first region is distributed throughout the film (hereinafter, also referred to as a cloud structure). In other words, CAC-OS is a composite metal oxide in which the first region and the second region are mixed together.

[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 represented as [In], [Ga], and [Zn], respectively. For example, in the CAC-OS in the In-Ga-Zn oxide, the first region is a region where [In] is larger than [In] in the composition of the CAC-OS film. Also, the second region is a region where [Ga] is larger than [Ga] in the composition of the CAC-OS film. Alternatively, for example, the first region is a region where [In] is larger than [In] in the second region and [Ga] is smaller than [Ga] in the second region. Also, the second region is a region where [Ga] is larger than [Ga] in the first region and [In] is smaller than [In] in the first region.

[0445] Specifically, the first region is a region mainly composed of indium oxide, indium zinc oxide, etc., and the second region is a region mainly composed of gallium oxide, gallium zinc oxide, etc. In other words, the first region can be rephrased as a region mainly composed of In, and the second region can be rephrased as a region mainly composed of Ga.

[0446] In addition, there are cases where a clear boundary between the first region and the second region cannot be observed.

[0447] In addition, the CAC-OS in In-Ga-Zn oxide refers to a structure in which some regions mainly composed of Ga and some regions mainly composed of In are arranged randomly in a mosaic pattern in a material structure containing In, Ga, Zn, and O. Therefore, it is presumed that the CAC-OS has a structure in which metal elements are distributed non-uniformly.

[0448] CAC-OS can be formed, for example, by a sputtering method under conditions where the substrate is not heated. When CAC-OS is formed by a sputtering method, any one or more selected from an inert gas (typically argon), oxygen gas, and nitrogen gas may be used as the film formation gas. The lower the flow rate ratio of oxygen gas to the total flow rate of film formation gas during film formation, the more preferable it is. For example, the flow rate ratio of oxygen gas to the total flow rate of film formation gas during film formation is preferably 0% or more and less than 30%, and more preferably 0% or more and 10% or less.

[0449] Furthermore, for example, in the case of a CAC-OS of an In-Ga-Zn oxide, EDX mapping obtained using EDX (Energy Dispersive X-ray spectroscopy) can confirm that the CAC-OS has a structure in which a region mainly composed of In (first region) and a region mainly composed of Ga (second region) are unevenly distributed and mixed.

[0450] Here, the first region is a region with higher conductivity than the second region. In other words, the first region exhibits conductivity as a metal oxide when carriers flow through the first region. Therefore, the first region is distributed in a cloud-like shape in the metal oxide, thereby realizing a high field-effect mobility (μ).

[0451] On the other hand, the second region has higher insulating properties than the first region. That is, the second region is distributed in the metal oxide, so that leakage current can be suppressed.

[0452] Therefore, when CAC-OS is used in a transistor, the conductivity due to the first region and the insulating property due to the second region act in a complementary manner, giving the CAC-OS a switching function (On / Off function). In other words, CAC-OS has a conductive function in part of the material and an insulating function in part of the material, and the material as a whole functions as a semiconductor. By separating the conductive function from the insulating function, it is possible to maximize both functions. Therefore, by using CAC-OS in a transistor, it is possible to achieve a high on-current (I on ), high field effect mobility (μ), and good switching operation can be achieved.

[0453] In addition, a transistor using CAC-OS has high reliability, making it ideal for various semiconductor devices such as display devices.

[0454] Oxide semiconductors have a variety of structures and each structure has different characteristics. The oxide semiconductor of one embodiment of the present invention may include two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, an a-like OS, a CAC-OS, an nc-OS, and a CAAC-OS.

[0455] <Transistor Having Oxide Semiconductor> Next, the case where the oxide semiconductor is used for a transistor will be described.

[0456] By using the oxide semiconductor for a transistor, a transistor with high field-effect mobility and high reliability can be realized.

[0457] For the transistor, an oxide semiconductor having a low carrier concentration is preferably used. For example, the carrier concentration of the oxide semiconductor is 1×10 17 cm -3 Less than or equal to 1×10 15 cm -3 Less than 1×10, more preferably 13 cm -3Less than or equal to 1×10 11 cm -3 Less than 1×10, more preferably 10 cm -3 Less than 1 x 10 -9 cm -3 The above is the case. Note that in order to reduce the carrier concentration of an oxide semiconductor film, the impurity concentration in the oxide semiconductor film may be reduced to reduce the density of defect states. In this specification and the like, an oxide semiconductor having a low impurity concentration and a low density of defect states is referred to as a high-purity intrinsic or substantially high-purity intrinsic oxide semiconductor. Note that an oxide semiconductor having a low carrier concentration may be referred to as a high-purity intrinsic or substantially high-purity intrinsic oxide semiconductor.

[0458] In addition, a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor film has a low density of defect states, and therefore the density of trap states might also be low.

[0459] In addition, charges trapped in the trap states of an oxide semiconductor take a long time to disappear and may behave as if they are fixed charges. Therefore, a transistor in which a channel formation region is formed in an oxide semiconductor with a high density of trap states may have unstable electrical characteristics.

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

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

[0462] When an oxide semiconductor contains silicon or carbon, which is one of the group 14 elements, defect levels are formed in the oxide semiconductor. For this reason, the concentrations of silicon, carbon, etc. in the oxide semiconductor and the concentrations of silicon, carbon, etc. near the interface with the oxide semiconductor (concentrations obtained by secondary ion mass spectrometry (SIMS)) are set to 2×10 18 atoms / cm 3 Less than or equal to 2 x 10 17 atoms / cm 3 The following applies.

[0463] In addition, when an oxide semiconductor contains an alkali metal or an alkaline earth metal, defect levels are formed and carriers are generated in some cases. Therefore, a transistor using an oxide semiconductor containing an alkali metal or an alkaline earth metal is likely to have normally-on characteristics. For this reason, when the concentration of an alkali metal or an alkaline earth metal in an oxide semiconductor obtained by SIMS is 1×10 18 atoms / cm 3 Less than or equal to 2 x 10 16 atoms / cm 3 To the following:

[0464] Furthermore, when nitrogen is contained in an oxide semiconductor, electrons serving as carriers are generated, the carrier concentration increases, and the semiconductor is likely to become n-type. As a result, a transistor using an oxide semiconductor containing nitrogen as a semiconductor is likely to have normally-on characteristics. Alternatively, when nitrogen is contained in an oxide semiconductor, trap states may be formed. As a result, the electrical characteristics of the transistor may become unstable. For this reason, the nitrogen concentration in an oxide semiconductor obtained by SIMS is set to 5×10 19 atoms / cm 3 Less than 5 x 10 18 atoms / cm 3 Less than or equal to 1×10 18 atoms / cm 3 Less than 5×10, more preferably 17 atoms / cm 3 To the following:

[0465] Furthermore, hydrogen contained in an oxide semiconductor reacts with oxygen bonded to a metal atom to form water, which may form an oxygen vacancy. When hydrogen enters the oxygen vacancy, electrons serving as carriers may be generated. In addition, some of the hydrogen may bond with oxygen bonded to a metal atom to generate electrons serving as carriers. Therefore, a transistor using an oxide semiconductor containing hydrogen is likely to have normally-on characteristics. For this reason, it is preferable to reduce hydrogen in the oxide semiconductor as much as possible. Specifically, when the hydrogen concentration in an oxide semiconductor measured by SIMS is 1×10 20 atoms / cm 3 Less than 1 x 10 19 atoms / cm 3 less than 5×10 18 atoms / cm 3 less than 1×10 18 atoms / cm 3 Make it less than.

[0466] When an oxide semiconductor in which impurities are sufficiently reduced is used for a channel formation region of a transistor, stable electrical characteristics can be obtained.

[0467] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification. [Explanation of symbols]

[0468] 10: vehicle control device, 20, 20a to 20d: light receiving and emitting units, 21, 21R, 21G, 21B, 21IR: light emitting elements, 22: light receiving elements, 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: spokes, 45: shaft, 51: hand, 51L: left hand, 51R: right hand

Claims

1. The device has an operation unit, a first light receiving and emitting unit, a control unit, and a second light receiving and emitting unit, the operating 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 receiving and emitting unit is provided along a surface of the rim, the first light receiving and emitting unit has a first light emitting element, a first light receiving element, and a third light emitting 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 the light 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 receiving and emitting unit has a function of sequentially outputting light receiving data to the control unit; The control unit has a function of acquiring biometric information of the driver from the plurality of pieces of light reception data and executing a process according to the biometric information; the second light receiving and emitting unit is provided along a surface of the hub or the spokes, the second light receiving and emitting unit has a second light emitting element, a second light receiving element, and a fourth light emitting element, the second light-emitting element has a function of emitting light in a second wavelength range, the second light receiving element has a function of receiving light in the second wavelength range and converting it into an electrical signal; the third light-emitting element has a function of emitting light in a third wavelength range, the fourth light-emitting element has a function of emitting light in a fourth wavelength range, the first light-emitting element has a laminated structure in which a first electrode, a light-emitting layer, and a common electrode are laminated; the first light receiving element has a laminated structure in which a second electrode, an active layer, and the common electrode are laminated; the light-emitting layer and the active layer each contain a different organic compound; The first electrode and the second electrode are provided on the same plane and spaced apart from each other, The common electrode is provided to cover the light emitting layer and the active layer. Vehicle control device.

2. A device comprising an operating unit, a first light receiving and emitting unit, a control unit, and a second light receiving and emitting unit; the operating 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 receiving and emitting unit is provided along a surface of the rim, the first light receiving and emitting unit has a first light emitting element, a first light receiving element, and a third light emitting 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 the light 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 receiving and emitting unit has a function of sequentially outputting light receiving data to the control unit; The control unit has a function of acquiring biometric information of the driver from the plurality of pieces of light reception data and executing a process according to the biometric information; the second light receiving and emitting unit is provided along a surface of the hub or the spokes, the second light receiving and emitting unit has a second light emitting element, a second light receiving element, and a fourth light emitting element, the second light-emitting element has a function of emitting light in a second wavelength range, the second light receiving element has a function of receiving light in the second wavelength range and converting it into an electrical signal; the third light-emitting element has a function of emitting light in a third wavelength range, the fourth light-emitting element has a function of emitting light in a fourth wavelength range, the first light-emitting element has a laminated structure in which a first electrode, a common layer, a light-emitting layer, and a common electrode are laminated; the first light receiving element has a laminated structure in which a second electrode, the common layer, an active layer, and the common electrode are laminated, the light-emitting layer and the active layer each contain a different organic compound; The first electrode and the second electrode are provided on the same plane and spaced apart from each other, the common electrode is provided to cover the light emitting layer and the active layer; the common layer is provided to cover the first electrode and the second electrode; Vehicle control device.

3. In claim 1 or claim 2, the light in the first wavelength range includes infrared light, the light in the second wavelength range includes infrared light, the light in the third wavelength range includes visible light, The light in the fourth wavelength range includes visible light. Vehicle control device.

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