Display device, display module, and electronic device

Abstract

Provided is a display device equipped with both a touch detection function and a fingerprint or vein shape imaging function. The display device includes a first light-emitting element, a second light-emitting element, a light-receiving element, and a light shielding layer. The first light-emitting element and the light-receiving element are arranged side by side on the same plane. The light shielding layer is provided above the first light-emitting element and the light-receiving element. The second light-emitting element is provided above the light shielding layer. The first light-emitting element has a function for emitting visible light upward. The second light-emitting element has a function for emitting invisible light upward. The light-receiving element is a photoelectric conversion element that is sensitive to visible light and invisible light. In addition, the light shielding layer has a part positioned between the first light-emitting element and the light-receiving element in a planar view, and the second light-emitting element overlaps with the light shielding layer in a planar view and is positioned further to the inside than the contour of the light shielding layer.

Description

Technical Field

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

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

Background Art

[0003] In recent years, information terminal devices such as mobile phones such as smartphones, tablet-type information terminals, and notebook PCs (personal computers) have become widely popular. Such information terminal devices often contain personal information, and various authentication technologies for preventing unauthorized use have been developed.

[0004] For example, Patent Document 1 discloses an electronic device provided with a fingerprint sensor in a push button switch section.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] When adding an authentication function such as fingerprint authentication to an electronic device that functions as a portable information terminal device, it is necessary to mount a module for imaging a fingerprint or the like on the electronic device. Therefore, as the number of components increases, the cost of the electronic device increases.

[0007] One aspect of the present invention aims to reduce the cost of an electronic device having an authentication function. Or, one aspect of the present invention aims to reduce the number of components of an electronic device. Or, one aspect of the present invention aims to provide a display device capable of imaging a fingerprint or a vein pattern or the like. Or, one aspect of the present invention aims to provide a display device having both a touch detection function and a fingerprint or vein pattern imaging function. Or, one aspect of the present invention aims to provide an electronic device having a biometric authentication function such as a fingerprint authentication function and a high screen occupancy rate. Or, one aspect of the present invention aims to provide a display device capable of emitting both visible light and infrared light. Or, one aspect of the present invention aims to provide an imaging device capable of imaging using both visible light and infrared light as light sources.

[0008] One aspect of the present invention aims to provide a display device, an imaging device, an electronic device, or the like having a novel configuration. One aspect of the present invention aims to at least reduce at least one of the problems of the prior art.

[0009] Note that the description of these problems does not prevent the existence of other problems. Note that one aspect of the present invention does not need to solve all of these problems. Note that other problems can be extracted from the descriptions in the specification, drawings, claims, and the like.

Means for Solving the Problems

[0010] One aspect of the present invention is a display device having a first light-emitting element, a second light-emitting element, a light-receiving element, and a light-shielding layer. The first light-emitting element and the light-receiving element are arranged side by side on the same plane. The light-shielding layer is provided above the first light-emitting element and the light-receiving element. The second light-emitting element is provided above the light-shielding layer. The first light-emitting element has a function of emitting visible light upward. The second light-emitting element has a function of emitting invisible light upward. The light-receiving element is a photoelectric conversion element having sensitivity to visible light and invisible light. Also, in plan view, the light-shielding layer has a portion located between the first light-emitting element and the light-receiving element. Also, in plan view, the second light-emitting element overlaps the light-shielding layer and is located inside the contour of the light-shielding layer.

[0011] Another aspect of the present invention is a display device having a first substrate, a second substrate, a first light-emitting element, a second light-emitting element, a light-receiving element, a light-shielding layer, a first resin layer, and a second resin layer. The first light-emitting element and the light-receiving element are arranged side by side on the first substrate. The first resin layer is provided on the first light-emitting element and the light-receiving element. The light-shielding layer is provided on the first resin layer. The second resin layer is provided on the light-shielding layer. The second light-emitting element is provided on the second resin layer. The second substrate is provided on the second light-emitting element. The first light-emitting element has a function of emitting visible light upward. The second light-emitting element has a function of emitting invisible light upward. The light-receiving element is a photoelectric conversion element having sensitivity to visible light and invisible light. Also, in plan view, the light-shielding layer has a portion located between the first light-emitting element and the light-receiving element. Also, in plan view, the second light-emitting element overlaps the light-shielding layer and is located inside the contour of the light-shielding layer.

[0012] Also, in the above, the invisible light preferably has intensity in a wavelength range of 750 nm or more and 900 nm or less.

[0013] Also, in any of the above, it is preferable to have a first protective layer. At this time, the first protective layer preferably contains an inorganic insulating material and is preferably located between the first light-emitting element and the light-receiving element and the first resin layer. Furthermore, the first resin layer is preferably provided along the upper surface of the first protective layer.

[0014] Also, in any of the above, it is preferable to have a second protective layer. At this time, the second protective layer preferably contains an inorganic insulating material and is preferably located between the second resin layer and the second light-emitting element. Furthermore, the light-shielding layer is preferably provided along the lower surface of the second resin layer.

[0015] Also, in any of the above, the first resin layer preferably exhibits a first refractive index with respect to light having a wavelength of 850 nm, and the second resin layer preferably exhibits a second refractive index with respect to light having a wavelength of 850 nm. Furthermore, the difference between the first refractive index and the second refractive index is preferably 10% or less of the first refractive index.

[0016] Also, in any of the above, the first light-emitting element preferably has a first pixel electrode, a first light-emitting layer, and a first electrode. Also, the light-receiving element preferably has a second pixel electrode, an active layer, and a first electrode. Also, the first light-emitting layer and the active layer preferably contain different organic compounds from each other. Also, the first electrode preferably has a portion that overlaps the first pixel electrode through the first light-emitting layer and a portion that overlaps the second pixel electrode through the active layer. Furthermore, the first pixel electrode and the second pixel electrode preferably contain the same conductive material.

[0017] Also, in any of the above, the second light-emitting element preferably has a third pixel electrode, a second light-emitting layer, and a second electrode from the second substrate side. At this time, the third pixel electrode preferably has translucency with respect to invisible light. Also, the second electrode preferably has reflectivity with respect to invisible light. Furthermore, in plan view, the second electrode is preferably located inside the contour of the light-shielding layer.

[0018] Alternatively, the second electrode preferably has translucency to visible light and invisible light. At this time, in plan view, the second electrode preferably has a portion overlapping with the light shielding layer, a portion overlapping with the first light emitting element, and a portion overlapping with the light receiving element.

[0019] Alternatively, in any of the above, it is preferable to have a reflective layer. At this time, the second light emitting element preferably has a third pixel electrode, a second light emitting layer, and a second electrode from the second substrate side. Further, the third pixel electrode and the second electrode preferably have translucency to invisible light. The reflective layer preferably has reflectivity to invisible light and is located between the light shielding layer and the second electrode. Furthermore, in plan view, the reflective layer is preferably located inside the contour of the light shielding layer.

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

[0021] Another aspect of the present invention is an electronic device having the above display module and at least one of an antenna, a battery, a housing, a camera, a speaker, a microphone, a touch sensor, and an operation button. Further, the electronic device preferably has a first imaging function of receiving, by the light receiving element, first reflected light when visible light is emitted from the first light emitting element, and a second imaging function of receiving, by the light receiving element, second reflected light when invisible light is emitted from the second light emitting element.

Advantages of the Invention

[0022] According to one aspect of the present invention, the cost of an electronic device having an authentication function can be reduced. Or, the number of components of the electronic device can be reduced. Or, a display device capable of imaging a fingerprint or a vein pattern or the like can be provided. Or, a display device having both a touch detection function and an imaging function of a fingerprint or a vein pattern can be provided. Or, an electronic device having a biometric authentication function such as fingerprint authentication and a high screen occupancy rate can be provided. Or, a display device or the like capable of emitting both visible light and infrared light can be provided. Or, an imaging device or the like capable of imaging using both visible light and infrared light as light sources can be provided.

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

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

Brief Description of the Drawings

[0025] FIGS. 1A to 1C are diagrams showing a configuration example of a display device. FIGS. 2A and 2B are diagrams showing a configuration example of a display device. FIGS. 3A and 3B are diagrams showing a configuration example of a display device. FIGS. 4A to 4C are diagrams showing a configuration example of a display device. FIGS. 5A to 5C are diagrams showing a configuration example of a display device. FIGS. 6A to 6D are diagrams showing a configuration example of a display device. FIGS. 7A and 7B are diagrams showing a configuration example of a display device. FIGS. 8A to 8G are diagrams showing a configuration example of a display device. FIG. 9 is a diagram showing a configuration example of a display device. FIG. 10A is a diagram showing a configuration example of a display device. FIG. 10B is a diagram showing a configuration example of a transistor. FIGS. 11A to 11C are diagrams showing a configuration example of an electronic device. FIG. 12 is a diagram showing a configuration example of an electronic device. FIG. 13 is a diagram showing a configuration example of an electronic device. FIG. 14 is a diagram showing a configuration example of a system. FIG. 15 is a flowchart for explaining an operation method of the system. FIGS. 16A and 16B are diagrams showing a configuration example of a pixel circuit. FIGS. 17A and 17B are diagrams showing a configuration example of an electronic device. FIGS. 18A to 18D are diagrams showing a configuration example of an electronic device. FIGS. 19A to 19F are diagrams showing a configuration example of an electronic device. FIG. 20 is a measurement result of the external quantum efficiency of a light receiving element. FIG. 21A is a schematic diagram of a light emitting element. FIG. 21B is a measurement result of the light emission intensity of the light emitting element. FIG. 22A is a measurement result of the external quantum efficiency-current density characteristics of a light emitting element. FIG. 22B is a measurement result of the current density-voltage characteristics of the light emitting element. FIGS. 23A and 23D are schematic diagrams showing an imaging method. FIGS. 23B, 23C, and 23E are imaging results.

Embodiments for Carrying Out the Invention

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

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

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

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

[0030] In addition, in the following, expressions indicating directions such as "up" and "down" are basically used in accordance with the direction of the drawing. However, for the purpose of facilitating the explanation or the like, the direction indicated by "up" or "down" in the specification may not match the drawing. As an example, when explaining the stacking order (or formation order) of a laminate or the like, even if the surface (formed surface, support surface, adhesive surface, flat surface, etc.) on the side where the laminate is provided in the drawing is located above the laminate, the direction may be expressed as down, and the opposite direction as up, etc.

[0031] In this specification and the like, a display panel, which is an aspect of a display device, has a function of displaying (outputting) an image or the like on a display surface. Therefore, the display panel is an aspect of an output device.

[0032] In addition, in this specification and the like, an object in which a connector such as an FPC (Flexible Printed Circuit) or a TCP (Tape Carrier Package) is attached to a substrate of a display panel, or an object in which an IC is mounted on the substrate by a COG (Chip On Glass) method or the like may be referred to as a display panel module, a display module, or simply a display panel.

[0033] Note that in this specification and the like, a touch panel, which is an aspect of a display device, has a function of displaying an image or the like on a display surface and a function as a touch sensor that detects that an object to be detected such as a finger or a stylus touches, presses, or approaches the display surface. Therefore, the touch panel is an aspect of an input / output device.

[0034] A touch panel can also be referred to as, for example, a display panel (or display device) with a touch sensor, or a display panel (or display device) with a touch sensor function. The touch panel can also be configured to have a display panel and a touch sensor panel. Alternatively, it can be configured to have a function as a touch sensor inside or on the surface of the display panel.

[0035] Also, in this specification and the like, a touch panel substrate on which a connector or an IC is mounted may be referred to as a touch panel module, a display module, or simply a touch panel.

[0036] (Embodiment 1) In this embodiment, a display device according to an aspect of the present invention will be described.

[0037] A display device according to an aspect of the present invention includes a first light-emitting element that emits visible light, a second light-emitting element that emits invisible light, and a light-receiving element that is sensitive to invisible light and visible light. The first light-emitting element has a function as a display element for displaying an image using visible light. The light-receiving element is preferably a photoelectric conversion element.

[0038] The first light-emitting element and the light-receiving element are preferably arranged side by side on the same plane. Also, the second light-emitting element is preferably provided on a plane different from the first light-emitting element and the light-receiving element.

[0039] As the first light-emitting element and the second light-emitting element, it is preferable to use an EL element such as an OLED (Organic Light Emitting Diode) or a QLED (Quantum-dot Light Emitting Diode). Examples of the light-emitting substances included in the EL element are substances that emit fluorescence (fluorescent materials), substances that emit phosphorescence (phosphorescent materials), inorganic compounds (such as quantum dot materials), substances that exhibit thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) materials), and the like. In addition, as the light-emitting element, an LED such as a micro LED (Light Emitting Diode) can also be used.

[0040] As the light-receiving element, for example, a pn-type or pin-type photodiode can be used. The light-receiving element functions as a photoelectric conversion element that detects light incident on the light-receiving element and generates electric charges. The amount of electric charges generated by the photoelectric conversion element is determined according to the amount of incident light. In particular, as the light-receiving element, it is preferable to use an organic photodiode having a layer containing an organic compound. The organic photodiode can be easily thinned, lightened, and enlarged in area, and also has a high degree of freedom in shape and design, so it can be applied to various display devices.

[0041] The first light-emitting element and the second light-emitting element can have, for example, a laminated structure including a light-emitting layer between a pair of electrodes. In addition, the light-receiving element can have a laminated structure including an active layer between a pair of electrodes. A semiconductor material can be used for the active layer of the light-receiving element. For example, an inorganic semiconductor material such as silicon can be used.

[0042] In particular, it is preferable to use an OLED as the first light-emitting element and the second light-emitting element, and an organic photo diode (OPD) as the light-receiving element. Thereby, since the production equipment, manufacturing apparatus, and materials that can be used for these for manufacturing the first light-emitting element, the second light-emitting element, and the light-receiving element can be partially shared, the manufacturing cost can be reduced. Furthermore, since these manufacturing processes can be simplified, the manufacturing yield can be improved.

[0043] Also, when an organic compound is used for the active layer of the light-receiving element, it is preferable to provide one electrode of the first light-emitting element and one electrode of the light-receiving element (both also referred to as pixel electrodes) on the same plane. Further, it is more preferable that the other electrode of the first light-emitting element and the other electrode of the light-receiving element be electrodes (also referred to as common electrodes) formed by a continuous single conductive layer. Furthermore, it is more preferable that the first light-emitting element and the light-receiving element have a common layer. Thereby, the manufacturing process when manufacturing the first light-emitting element and the light-receiving element can be simplified, the manufacturing cost can be reduced, and the manufacturing yield can be improved.

[0044] By separately forming the light-emitting layer of the first light-emitting element and the active layer of the light-receiving element, the first light-emitting element and the light-receiving element can be formed on the same plane. For example, the light-emitting layer and the active layer can be formed in an island shape or a strip shape by a film-forming method using a shielding mask such as a metal mask. In the film-forming method using a shielding mask, in consideration of the spread of the film to be formed, a margin (also referred to as a blank space or an allowable portion) may be provided between two island-shaped patterns formed by different shielding masks.

[0045] Note that a light-shielding layer that shields light having a wavelength received by the light-receiving element can be provided in this margin. Further, the light-shielding layer can be configured to have an opening or a slit that defines the light-emitting region of the first light-emitting element and the light-receiving region of the light-receiving element.

[0046] Since the margin is an area that does not contribute to light emission and light reception, it leads to a decrease in the ratio of the light-emitting area or the light-receiving area to the area of the display unit of the display device (effective light-emitting area ratio or effective light-receiving area ratio).

[0047] Therefore, in one aspect of the present invention, a second light-emitting element that emits invisible light is provided in a portion corresponding to the margin. The invisible light can be used as a light source when the light-receiving element images a subject. Further, the second light-emitting element is preferably disposed above the light-shielding layer (on the display surface side). Further, the second light-emitting element preferably overlaps the light-shielding layer and is provided inside the contour of the light-shielding layer in a plan view. That is, it is preferable to provide the second light-emitting element such that the end portion of the light-emitting region of the second light-emitting element is located inside the end portion of the light-shielding layer. Thereby, since a part of the invisible light emitted by the second light-emitting element is shielded by the light-shielding layer, it is possible to prevent direct incidence on the light-receiving element. Thereby, the display device can capture a clear image with reduced noise.

[0048] Examples of the invisible light include infrared light or ultraviolet light. In particular, infrared light having one or more peaks in the range of 700 nm or more and 2500 nm or less can be preferably used. In particular, it is preferable to use light having intensity in the wavelength range of 750 nm or more and 1000 nm or less, preferably light having one or more peaks in this wavelength range, because the range of selection of the material used for the active layer of the light-receiving element is widened.

[0049] By using the above-described infrared light as the invisible light, the display device can also image blood vessels such as fingers or hands, particularly veins, using the light-receiving element. For example, light having a wavelength of 760 nm and its vicinity is not absorbed by reduced hemoglobin in the vein, so the position of the vein can be detected by receiving reflected light from the palm or finger with the light-receiving element and imaging it. A module or an electronic device having the display device according to one aspect of the present invention can perform vein authentication, which is one type of biometric authentication, using the captured vein image.

[0050] In addition, by using the visible light emitted by the first light-emitting element as a light source, it is possible to image the palm print on the palm and the shape of the fingerprint on the fingertip. Also, since a part of the infrared light is reflected on the surface of the skin, the infrared light emitted by the second light-emitting element can also be used for imaging the shape of the fingerprint or the like. A module or an electronic device having the display device according to one aspect of the present invention can perform fingerprint authentication, which is one type of biometric authentication, using the captured fingerprint image.

[0051] Hereinafter, a more specific configuration example will be described with reference to the drawings.

[0052] [Configuration Example 1 of Display Device] FIG. 1A shows a configuration example of a display device 10. The display device 10 includes a light-emitting element 21R, a light-emitting element 21G, a light-emitting element 21B, a light-receiving element 22, a light-emitting element 23IR, a light-shielding layer 24, etc. between a substrate 11 and a substrate 12.

[0053] The light-emitting element 21R, the light-emitting element 21G, the light-emitting element 21B, and the light-receiving element 22 are arranged side by side on the substrate 11. The light-shielding layer 24 is provided above the light-emitting element 21R, the light-emitting element 21G, and the light-emitting element 21B via an insulating layer 31. The light-emitting element 23IR is disposed on the light-shielding layer 24 via an insulating layer 32 in a stacked manner. The light-shielding layer 24 has portions located between the respective light-emitting elements and portions located between any one of the light-emitting elements and the light-receiving element 22 in a plan view. Similarly, the light-emitting element 23IR also has portions located between the respective light-emitting elements and portions located between any one of the light-emitting elements and the light-receiving element 22 in a plan view.

[0054] The light-emitting element 21R, the light-emitting element 21B, and the light-emitting element 21G emit red (R), blue (B), or green (G) light, respectively.

[0055] The display device 10 has a plurality of pixels arranged in a matrix. One pixel has one or more sub-pixels. One sub-pixel has one light-emitting element. For example, the pixel may have a configuration with three sub-pixels (such as three colors of R, G, B, or three colors of yellow (Y), cyan (C), and magenta (M)), or a configuration with four sub-pixels (such as four colors of R, G, B, white (W), or four colors of R, G, B, Y). Further, the pixel has a light-receiving element 22. The light-receiving element 22 may be provided in all pixels or in some pixels. Also, one pixel may have a plurality of light-receiving elements 22.

[0056] A margin necessary for differentiating them is provided between two adjacent light-emitting elements and between the light-emitting element and the light-receiving element 22. In FIG. 1A, the light-emitting element 21R and the light-emitting element 21B are arranged at an interval of distance M. For example, when forming an island-shaped organic film by a vacuum deposition method using a metal mask as a film constituting the light-emitting element or the light-receiving element, due to the alignment accuracy between the metal mask and the substrate, the deflection of the metal mask, and the scattering of vapor, etc., a deviation from the design may occur in the shape and position of the island-shaped organic film. Therefore, it is preferable that the distance M between adjacent elements is 10 μm or more, preferably 20 μm or more, more preferably 30 μm or more, and 200 μm or less, preferably 100 μm or less.

[0057] In this specification etc., when referring to a light-emitting element, it may mean a light-emitting region. As a specific example, when the light-emitting element has a pair of electrodes and a light-emitting layer therebetween, the region where these are laminated and emit light when an electric field is applied may be expressed as the light-emitting element (light-emitting region). Therefore, a part or all of the components of the light-emitting element may be located in a region different from the light-emitting region. Similarly, when referring to a light-receiving element, it may mean a light-receiving region.

[0058] The light-emitting element 23IR emits invisible light. Here, an example in which the light-emitting element 23IR emits infrared light IR is shown.

[0059] The light receiving element 22 is a photoelectric conversion element having sensitivity to at least the infrared light emitted by the light emitting element 23IR. The light receiving element 22 may have sensitivity, for example, within a wavelength range of 700 nm or more and 900 nm or less.

[0060] In addition, the light receiving element 22 preferably has sensitivity not only to infrared light but also to the light emitted by the light emitting element 21R, the light emitting element 21B, and the light emitting element 21G, respectively. When the light receiving element 22 has sensitivity to visible light and infrared light, it preferably has sensitivity, for example, within a wavelength range of 500 nm or more and 1000 nm or less, within a wavelength range of 500 nm or more and 950 nm or less, or within a wavelength range of 500 nm or more and 900 nm or less.

[0061] FIG. 1A shows a state where the finger 60 is touching the surface of the substrate 12. At this time, a part of the infrared light IR emitted from the light emitting element 23IR is reflected on the surface or inside of the finger 60, and a part of the reflected light is incident on the light receiving element 22. Thereby, the information on the position where the finger 60 touches can be acquired. In addition, one or both of the vein shape and the fingerprint shape of the finger 60 can be imaged.

[0062] In addition, the position information of the finger 60 or the fingerprint can be imaged by the light emitted from any one of the light emitting element 21R, the light emitting element 21B, and the light emitting element 21G. FIG. 1B shows, as an example, a state where the light receiving element 22 receives the reflected light from the finger 60 among the light G emitted from the light emitting element 21G.

[0063] In addition, as shown in FIG. 1C, even when the finger 60 is separated from the substrate 12, the position information of the finger 60 can be acquired. That is, the display device 10 can function as a non-contact touch panel. Depending on the distance between the finger 60 and the substrate 12, it may be possible to acquire the shape of the fingerprint or vein. In that case, the module or electronic device to which the display device 10 is applied can function as a non-contact biometric authentication device.

[0064] The smaller the array pitch of the light-receiving elements 22, the higher-resolution image can be captured. For example, by setting the array pitch of the light-receiving elements 22 to be smaller than the distance between two convex portions of a fingerprint, preferably the distance between an adjacent concave portion and convex portion, a clear fingerprint image can be obtained. Since the distance between the concave and convex portions of a human fingerprint is generally 200 μm, for example, the array pitch of the light-receiving elements 22 is 400 μm or less, preferably 200 μm or less, more preferably 150 μm or less, still more preferably 100 μm or less, and still more preferably 50 μm or less, and is 1 μm or more, preferably 10 μm or more, more preferably 20 μm or more.

[0065] Note that the display device 10 can capture images of various objects that contact or approach the surface of the substrate 12, not just fingerprints. Therefore, the display device 10 can also be used as an image sensor panel. For example, by sequentially emitting light from the light-emitting element 21R, the light-emitting element 21B, and the light-emitting element 21G, and capturing an image with the light-receiving element 22 each time, and synthesizing the three obtained images, a color image can be obtained. That is, the electronic device to which the display device 10 is applied can also be used as a color imaging-capable image scanner. Also, by capturing an image with the light-receiving element 22 in a state where the light-emitting element 23IR is emitting light, it can be used as an image scanner using infrared light.

[0066] Also, the display device 10 can function as a touch panel or a tablet using the light-receiving elements 22. By using the light-receiving elements 22, different from the case of using a capacitive touch sensor or an electromagnetic induction type touch sensor, etc., since position detection is possible even for a highly insulating detection object, the material of the detection object such as a stylus is not limited, and various writing utensils (for example, pens, glass pens, fountain pens, etc.) can be used.

[0067] [Configuration Example 2 of Display Device] Hereinafter, a more specific configuration example of the display device will be described.

[0068] FIG. 2A shows a schematic top view of the display device 100, as viewed from the display surface side, which will be exemplified below. FIG. 2B shows a schematic cross-sectional view corresponding to the cross-section cut along the dashed-dotted line X1-X2 in FIG. 2A.

[0069] The display device 100 includes a light-receiving element 110, a light-emitting element 190, a light-emitting element 160, a transistor 131, a transistor 132, a light-shielding layer 145, a resin layer 141, a resin layer 142, etc. between a pair of substrates (substrate 151 and substrate 152).

[0070] The light-emitting element 190 emits light of any one of red (R), green (G), and blue (B).

[0071] FIG. 2A shows the top surface shapes of the light-receiving element 110, the light-emitting element 190, the light-emitting element 160, and the light-shielding layer 145. For the light-emitting element 190, symbols R, G, and B are attached for each emission color for distinction. Also, the light-receiving element 110 is labeled with the symbol PD.

[0072] In FIG. 2A, a row in which the red (R) light-emitting elements 190 and the green (G) light-emitting elements 190 are alternately arranged, the light-receiving element 110, and a row in which the blue (B) light-emitting elements 190 are alternately arranged are alternately arranged in the column direction. Note that the relative positional relationship between each light-emitting element 190 and the light-receiving element 110 is not limited to this, and any two elements may be interchanged with each other.

[0073] A light-shielding layer 145 is provided between two adjacent light-emitting elements 190 and between an adjacent light-receiving element 110 and light-emitting element 190. Also, a light-emitting element 160 is disposed overlapping on the light-shielding layer 145. In FIG. 2A, a grid-shaped light-emitting element 160 is provided on the grid-shaped light-shielding layer 145. As shown in FIG. 2A, the light-emitting element 160 is preferably provided inside the contour of the light-shielding layer 145. In other words, in a plan view, it is preferable that an end portion of the light-shielding layer 145 is located between the light-receiving element 110 and the light-emitting element 160. Also, in a plan view, it is preferable that another end portion of the light-shielding layer 145 is located between the light-emitting element 190 and the light-emitting element 160.

[0074] In FIG. 2A, an example is shown in which the light-emitting element 160 is continuous over the entire display area. By adopting such a configuration, since the entire display area can be made to emit light or be in a non-light-emitting state, the control of driving the light-emitting element 160 can be extremely simplified.

[0075] FIG. 3A shows an example in which strip-shaped light-emitting elements 160 that are long in the row direction are arranged in the column direction. By adopting such a configuration, the strip-shaped light-emitting elements 160 can be caused to emit light in sequence.

[0076] Further, FIG. 3B shows an example in which island-shaped light-emitting elements 160 are arranged in a matrix. At this time, the light-emitting elements 160 can adopt a driving method by a passive matrix method. Alternatively, a driving method by an active matrix method may be adopted.

[0077] Note that, in FIG. 3B, for ease of understanding, the upper surface shape and size of the light-emitting element 160 are shown to be the same as those of the light-emitting element 190 and the light-receiving element 110, but the present invention is not limited thereto, and the upper surface shapes and sizes of the light-emitting element 160, each light-emitting element 190, and the light-receiving element 110 may be made different.

[0078] As shown in FIG. 2B, a transistor 131 and a transistor 132 are provided on a substrate 151, and an insulating layer 214 is provided thereon.

[0079] The light-receiving element 110 includes a pixel electrode 111, a photoelectric conversion layer 112, and a common electrode 113. The light-emitting element 190 includes a pixel electrode 191, an EL layer 192, and a common electrode 113. The photoelectric conversion layer 112 includes at least an active layer. The EL layer 192 includes at least a light-emitting layer.

[0080] The light-emitting element 190 has a function of emitting visible light. Specifically, the light-emitting element 190 is an electroluminescent element that emits light 121 toward the substrate 152 side by applying a voltage between the pixel electrode 191 and the common electrode 113.

[0081] The light-receiving element 110 has a function of detecting light. Specifically, the light-receiving element 110 is a photoelectric conversion element that receives the light 122 incident from the outside through the substrate 152 and converts it into an electrical signal.

[0082] The pixel electrode 111 and the pixel electrode 191 are provided on the same plane. The pixel electrode 111 and the pixel electrode 191 are preferably formed by processing the same conductive film. The pixel electrode 111 and the pixel electrode 191 preferably have a function of reflecting visible light and infrared light. The ends of the pixel electrode 111 and the pixel electrode 191 are covered by the partition wall 216. The common electrode 113 has a function of transmitting visible light and infrared light.

[0083] The common electrode 113 is provided in common for the light-receiving element 110 and the light-emitting element 190. Specifically, the common electrode 113 has a portion overlapping with the pixel electrode 111 through the photoelectric conversion layer 112 and a region overlapping with the pixel electrode 191 through the EL layer 192.

[0084] Note that the light-receiving element 110 and the light-emitting element 190 may have a layer provided in common other than the common electrode 113. For example, an active layer and a light-emitting layer may be separately formed, and all other layers may be commonly used.

[0085] The layers commonly used for the light-receiving element 110 and the light-emitting element 190 may have different functions in the light-emitting element and the light-receiving element. In this specification, components are named based on the functions in the light-emitting element. For example, the hole injection layer functions as a hole injection layer in the light-emitting element and functions as a hole transport layer in the light-receiving element. Similarly, the electron injection layer functions as an electron injection layer in the light-emitting element and functions as an electron transport layer in the light-receiving element. Also, the hole transport layer functions as a hole transport layer in both the light-emitting element and the light-receiving element. Similarly, the electron transport layer functions as an electron transport layer in both the light-emitting element and the light-receiving element.

[0086] A protective layer 195 is provided on a common electrode 113 so as to cover a light-receiving element 110 and a light-emitting element 190. The protective layer 195 has a function of preventing impurities such as water from diffusing into the light-receiving element 110 and the light-emitting element 190 from the resin layer 141 side. Further, by providing the protective layer 195, damage to the light-receiving element 110 and the light-emitting element 190 during the processes after the formation process of the protective layer 195 can be reduced.

[0087] The protective layer 195 can have a single-layer structure or a laminated structure including at least an inorganic insulating film. Examples of the inorganic insulating film include oxide films or nitride films such as a silicon oxide film, a silicon oxynitride film, a silicon nitride oxide film, a silicon nitride film, an aluminum oxide film, an aluminum oxynitride film, and a hafnium oxide film.

[0088] A resin layer 141 is provided so as to cover the protective layer 195. The resin layer 141 functions as a planarizing film.

[0089] A light-shielding layer 145 is provided on the resin layer 141. The light-shielding layer 145 preferably absorbs visible light and infrared light. As the light-shielding layer 145, for example, a black matrix can be formed using a metal material, or a resin material containing a pigment (such as carbon black) or a dye. The light-shielding layer 145 may have a laminated structure in which two or more of a red color filter, a green color filter, and a blue color filter are laminated.

[0090] A light-emitting element 160 is provided at a position overlapping the light-shielding layer 145. The light-emitting element 160 is formed on the substrate 152 side. The light-emitting element 160 has an electrode 161, an EL layer 162, and an electrode 163 from the substrate 152 side.

[0091] The light-emitting element 160 has a function of emitting infrared light. Specifically, the light-emitting element 160 is an electroluminescent element that emits light 123 to the substrate 152 side by applying a voltage between the electrode 161 and the electrode 163.

[0092] The insulating layer 217 is provided to cover the end portion of the electrode 161. The insulating layer 217 preferably functions as a planarization film.

[0093] In FIG. 2B, an example is shown in which the electrode 161, the EL layer 162, and the electrode 163 are processed so as to be located inside the contour of the light shielding layer 145 in a plan view, respectively. At this time, as shown in FIG. 2B, it is preferable that the end portion of the EL layer 162 is covered by the electrode 163. Thereby, the electrode 163 functions as a protective layer, and it is possible to prevent impurities such as water from diffusing from the resin layer 142 side to the EL layer 162, and the reliability of the light emitting element 160 can be improved.

[0094] Also, the electrode 163 preferably has a function of reflecting infrared light. The electrode 161 preferably has a function of transmitting infrared light.

[0095] As shown in FIG. 2B, it is preferable that the EL layer 162 and the electrode 163 are not provided on the upper part of the light emitting element 190 and the upper part of the light receiving element 110. Thereby, a display device with high luminous efficiency and light receiving sensitivity can be realized without a part of the light 121 and the light 122 being reflected or absorbed by the EL layer 162 and the electrode 163.

[0096] A resin layer 142 is provided to cover the light emitting element 160. A part of the resin layer 142 is provided in contact with the light shielding layer 145 and the resin layer 141. The resin layer 142 preferably functions as an adhesive layer for bonding the substrate 152 to the substrate 151.

[0097] Here, the resin layer 141 and the resin layer 142 are located on the optical path of the light 121 emitted by the light-emitting element 190. When the resin layer 141 and the resin layer 142 are in contact with each other, the smaller the difference in their refractive indices, the smaller the influence of refraction and reflection at their interface, and the higher the light extraction efficiency of the light-emitting element 190 can be increased. Furthermore, it is possible to suppress the reflection of the light 121 at the interface between the resin layer 141 and the resin layer 142 and a part of it directly incident on the light-receiving element 110. Therefore, it is preferable that the difference in the respective refractive indices of the resin layer 141 and the resin layer 142 with respect to the peak wavelength of the light 121 emitted by the light-emitting element 190 is 10% or less of the refractive index of the resin layer 141. In particular, it is preferable to use the same material for the resin layer 141 and the resin layer 142.

[0098] Also, the resin layer 141 and the resin layer 142 are similarly located on the optical path of the light 122 reaching the light-receiving element 110. By reducing the difference in their refractive indices, it becomes possible to increase the amount of light 122 reaching the light-receiving element 110. Therefore, it is preferable that the difference in the respective refractive indices of the resin layer 141 and the resin layer 142 with respect to the peak wavelength of the light 121 emitted by the light-emitting element 160 is 10% or less of the refractive index of the resin layer 141. In particular, it is preferable that the difference in the refractive indices of the resin layer 141 and the resin layer 142 with respect to the light having a wavelength of 850 nm is 10% or less of the refractive index of the resin layer 141.

[0099] The transistor 131 and the transistor 132 are in contact with the upper surface of the same layer (substrate 151 in FIG. 2B). The pixel electrode 111 is electrically connected to the source or drain of the transistor 131 through an opening provided in the insulating layer 214. The pixel electrode 191 is electrically connected to the source or drain of the transistor 132 through an opening provided in the insulating layer 214. The transistor 132 has a function of controlling the driving of the light-emitting element 190.

[0100] At least a part of the circuit electrically connected to the light-receiving element 110 is preferably formed of the same material and in the same process as the circuit electrically connected to the light-emitting element 190. Thereby, compared with the case where the two circuits are formed separately, the thickness of the display device can be reduced and the manufacturing process can be simplified.

[0101] Here, the common electrode 113 provided in common to the light-emitting element 190 and the light-receiving element 110 is preferably electrically connected to a wiring to which a first potential is applied. As the first potential, a fixed potential such as a common potential, a ground potential, or a reference potential can be used. Note that the first potential applied to the common electrode 113 is not limited to a fixed potential, and two or more different potentials can be selected and applied.

[0102] When the light-receiving element 110 receives light and converts it into an electrical signal, it is preferable to apply a second potential lower than the first potential applied to the common electrode 113 to the pixel electrode 111. The second potential can be selected and applied as a potential that optimizes the light-receiving sensitivity or the like according to the configuration, optical characteristics, and electrical characteristics of the light-receiving element 110. That is, when the light-receiving element 110 is regarded as a photodiode, the first potential applied to the common electrode 113 functioning as a cathode and the second potential applied to the pixel electrode 111 functioning as an anode can be selected so that a reverse bias voltage is applied. Note that when the light-receiving element 110 is not driven, the pixel electrode 111 may be applied with a potential equal to or approximately equal to the first potential, or a potential higher than the first potential.

[0103] On the other hand, when causing the light-emitting element 190 to emit light, it is preferable to apply a third potential to the pixel electrode 191 that is higher than the first potential applied to the common electrode 113. The third potential can be selected and applied so as to achieve the required emission luminance according to the configuration of the light-emitting element 190, the threshold voltage, the current-luminance characteristics, and the like. That is, when the light-emitting element 190 is regarded as a light-emitting diode, the first potential applied to the common electrode 113 functioning as a cathode and the third potential applied to the pixel electrode 191 functioning as an anode can be selected such that a forward bias voltage is applied. When the light-emitting element 190 is not caused to emit light, the pixel electrode 191 may be applied with a potential that is the same as or approximately the same as the first potential, or a potential lower than the first potential.

[0104] Here, an example in which the common electrode 113 functions as a cathode and each pixel electrode functions as an anode has been described for the light-receiving element 110 and the light-emitting element 190, but the present invention is not limited thereto, and a configuration in which the common electrode 113 functions as an anode and each pixel electrode functions as a cathode may also be employed. In that case, when driving the light-receiving element 110, a potential higher than the first potential may be applied as the second potential, and when driving the light-emitting element 190, a potential lower than the first potential may be applied as the third potential.

[0105] 〔Configuration Example 2-2〕 FIG. 4A shows a schematic cross-sectional view of a display device having a configuration partially different from the above. The display device 100A shown in FIG. 4A is mainly different from the above-described display device 100 in that the configuration of the light-emitting element 160 is different.

[0106] The light-shielding layer 145 is formed along the lower surface of the resin layer 142. In other words, the lower surface of the resin layer 142 forms the surface on which the light-shielding layer 145 is formed. Note that a different layer may be provided between the resin layer 142 and the light-shielding layer 145, and in that case, the resin layer 142 and the light-shielding layer 145 do not contact each other.

[0107] Further, a protective layer 169 is provided to cover the light-emitting element 160. The protective layer 169 can use the same material as the protective layer 195. In the manufacturing process of the display device 100A, since the light-shielding layer 145 is formed after the light-emitting element 160 is formed, by providing the protective layer 169 to cover the light-emitting element 160, damage to the light-emitting element 160 during the formation process of the light-shielding layer 145 can be suppressed.

[0108] Note that in FIG. 4A, if the protective layer 195 is unnecessary, it may not be provided.

[0109] 〔Configuration Example 2-3〕 FIG. 4B shows a schematic cross-sectional view of a display device 100B having a configuration different from the above.

[0110] The electrode 163t of the light-emitting element 160 has translucency with respect to visible light and infrared light. Further, the EL layer 162 and the electrode 163t of the light-emitting element 160 each have a portion overlapping with the light-receiving element 110 and a portion overlapping with the light-emitting element 190. With such a configuration, since a continuous film can be used for each of the EL layer 162 and the electrode 163t, the process can be simplified. In addition, since the EL layer 162 and the electrode 163t of the light-emitting element 160 can be formed continuously, it is possible to suppress the mixing of impurities (such as water) contained in the air between them, and the reliability can be improved.

[0111] Since the visible light emitted by the light-emitting element 190 passes through the EL layer 162 and the electrode 163t, it is preferable to apply a film having a small absorption with respect to visible light to each of the EL layer 162 and the electrode 163t. For example, it is preferable to select the materials and thicknesses of the EL layer 162 and the electrode 163t so that the transmittance of the laminate of the EL layer 162 and the electrode 163t is 50% or more and 100% or less, preferably 60% or more and 100% or less, more preferably 70% or more and 100% or less, with respect to the light emitted by the light-emitting element 190.

[0112] In addition, for the EL layer 162 and the electrode 163t, since the light 122, which is the light 123 containing the infrared light emitted by the light-emitting element 160 and reflected by the object, passes through, it is preferable to apply a film with low absorption to infrared light for each of them. For example, it is preferable to select the materials and thicknesses of the EL layer 162 and the electrode 163t such that the transmittance of the laminate of the EL layer 162 and the electrode 163t is 50% or more and 100% or less, preferably 60% or more and 100% or less, more preferably 70% or more and 100% or less, with respect to the infrared light emitted by the light-emitting element 160.

[0113] By increasing the transmittance of the EL layer 162 and the electrode 163 to visible light and infrared light, the light extraction efficiency is improved, so that the display brightness or the emission brightness of the display device can be increased. In addition, since the brightness of the light 122 reaching the light-receiving element 110 can be increased, the detection sensitivity can be increased.

[0114] In addition, between the light-shielding layer 145 and the electrode 163t of the light-emitting element 160, there is a reflective layer 168 having reflectivity to infrared light. The reflective layer 168 is provided on the light-shielding layer 145. The infrared light emitted from the light-emitting element 160 toward the substrate 151 side is reflected by the reflective layer 168 and emitted to the outside through the substrate 152. By providing the reflective layer 168, the light extraction efficiency of the light-emitting element 160 can be increased. The reflective layer 168 is provided so as to be located inside the contour of the light-shielding layer 145 in plan view.

[0115] 〔Configuration Example 2-4〕 FIG. 4C shows a schematic cross-sectional view of a display device 100C having a configuration different from the above.

[0116] The display device 100C shows an example in which the reflective layer 168 and the light-shielding layer 145 are formed on the substrate 152 side, respectively.

[0117] The reflective layer 168 is provided along the lower surface of the resin layer 142 covering the light-emitting element 160. In addition, a resin layer 143 is provided so as to cover the reflective layer 168 and the resin layer 142. Further, a light-shielding layer 145 is provided along the lower surface of the resin layer 143.

[0118] The resin layer 143 is located on the surface side where the light-shielding layer 145 is to be formed and has a function as a planarization layer. Note that the light-shielding layer 145 may be provided to cover the lower surface of the reflection layer 168 without providing the resin layer 143.

[0119] The resin layer 143 is located on the optical paths of the light 121 and the light 122 and is also located between the resin layer 142 and the resin layer 141. Therefore, it is preferable to use a material for the resin layer 143 with a small difference in refractive index from the resin layer 142 and the resin layer 141. It is more preferable to use the same material for the resin layer 141, the resin layer 142, and the resin layer 143.

[0120] In FIG. 4C, an example is shown in which the EL layer 162 and the electrode 163t included in the light-emitting element 160 are processed so as not to overlap with the light-emitting element 190 and the light-receiving element 110. However, similar to the display device 100B, it may be formed using a continuous film.

[0121] [Configuration Example 3 of Display Device] Hereinafter, an example of a circuit configuration that can be used in a display device will be described.

[0122] FIG. 5A shows a perspective schematic view of a display device 50. As shown in FIG. 5A, a display device according to an aspect of the present invention can also be regarded as having a configuration in which a layer 51 having a light-emitting element 21 and a light-receiving element 22 and a layer 52 having a light-emitting element 23 are laminated.

[0123] In the layer 51, the light-emitting element 21 and the light-receiving element 22 are each arranged in a matrix.

[0124] In the layer 52, a light-emitting element 23 is provided. Here, an example in which the light-emitting elements 23 are arranged in a matrix is shown. Note that the arrangement method of the light-emitting elements 23 is not limited to this, and one light-emitting element 23 covering the entire layer 52 may be arranged, or the light-emitting elements 23 having a strip-shaped upper surface shape may be arranged in one direction.

[0125] Next, a circuit for controlling the light emission and light reception of the display device 50 will be described.

[0126] FIG. 5B shows a block diagram for explaining a configuration example of the layer 51 and its peripheral circuits. The layer 51 has pixels 71 and 72. The pixel 71 functions as a sub-pixel and is a circuit for controlling the emission luminance of a light-emitting element 21 that emits any one of red, green, or blue light. The pixel 72 is a circuit for controlling the light reception operation and readout operation of the light-receiving element 22.

[0127] The pixel 71 has at least a transistor (selection transistor) for controlling the selection and non-selection of the pixel and a transistor (drive transistor) for controlling the current flowing through the light-emitting element 21. The pixel 71 can be driven by an active matrix method.

[0128] The pixel 72 also has at least a transistor (selection transistor) for controlling the selection and non-selection of the pixel. The pixel 72 can be driven by an active matrix method.

[0129] Circuit units 75a, 76a, 77, and 78 are electrically connected to the layer 51. The circuit unit 75a is electrically connected to a plurality of pixels 71 arranged in the row direction via a wiring GLa. The circuit unit 76a is electrically connected to a plurality of pixels 71 arranged in the column direction via a wiring SLa. The circuit unit 77 is electrically connected to a plurality of pixels 72 arranged in the row direction via a wiring CL. The circuit unit 78 is electrically connected to a plurality of pixels 72 arranged in the column direction via a wiring WL. Here, the wiring GLa, the wiring SLa, the wiring CL, and the wiring WL are shown as single wirings, but they may be a plurality of wirings to which different signals or potentials are supplied.

[0130] The circuit section 75a functions as a scanning line driving circuit (also referred to as a gate line driving circuit, a gate driver, a scan driver, etc.). The circuit section 75a has a function of generating a selection signal for selecting the pixel 71 and outputting it to the wiring GLa. The circuit section 76a functions as a signal line driving circuit (also referred to as a source line driving circuit, a source driver, etc.). The circuit section 76a has a function of outputting a data signal (data potential) to the wiring SLa.

[0131] The circuit section 77 functions as a scanning line driving circuit. The circuit section 77 has a function of generating a timing signal to be supplied to the pixel 72 and outputting it to the wiring CL. The circuit section 78 functions as a readout circuit. The circuit section 78 has a function of converting a signal output from the pixel 72 via the wiring WL into data (digital data or analog data) that can be processed by an external device and outputting the data.

[0132] FIG. 5C shows a block diagram for explaining a configuration example of the layer 52 and its peripheral circuits. The layer 52 has pixels 73. The pixel 73 is a circuit for controlling the emission luminance of the light emitting element 23. The pixel 73 can have the same configuration as the above-described pixel 71. The pixel 73 can be driven by an active matrix method.

[0133] A circuit section 75b and a circuit section 76b are electrically connected to the layer 52. The circuit section 75b is electrically connected to a plurality of pixels 73 arranged in the row direction via the wiring GLb. The circuit section 76b is electrically connected to a plurality of pixels 73 arranged in the column direction via the wiring SLb.

[0134] The circuit section 75b functions as a scanning line driving circuit, and the circuit section 76b functions as a signal line driving circuit. The descriptions of the circuit section 75a and the circuit section 76a can be respectively applied to the circuit section 75b and the circuit section 76b.

[0135] The light-emitting element 23 included in layer 52 may be configured to control light emission by a passive matrix method or a segment method. Thereby, since the configuration of the pixel and the configuration of the peripheral circuit can be simplified, the manufacturing cost can be reduced.

[0136] FIG. 6A shows an example when the driving method of the passive matrix method is applied.

[0137] The display device shown in FIG. 6A includes a layer 52a, a circuit section 79a, and a circuit section 79b. In the layer 52a, a plurality of light-emitting elements 23 are arranged in a matrix. The circuit section 79a is electrically connected to the anodes of the plurality of light-emitting elements 23 arranged in the row direction via a wiring SL X The circuit section 79b is electrically connected to the cathodes of the plurality of light-emitting elements 23 arranged in the column direction via a wiring SL Y The light-emitting element 23 can emit light with a luminance corresponding to the potential difference between the anode potential supplied from the circuit section 79a via the wiring SL

[0138] X and the cathode potential supplied from the circuit section 79b via the wiring SL Y Y The light-emitting element 23 can emit light with a luminance corresponding to the potential difference between the anode potential supplied from the circuit section 79a via the wiring SL

[0139] FIG. 6B shows an example when the driving method of the segment method is applied.

[0140] The display device shown in FIG. 6B includes a layer 52b and a circuit section 79c. In the layer 52b, a plurality of light-emitting elements 23 are arranged in a matrix. The circuit section 79c has a plurality of wirings AL electrically connected thereto. The anode of one light-emitting element 23 is electrically connected to one wiring AL. An anode potential is supplied to the anode of the light-emitting element 23 from the circuit section 79c via the wiring AL. Further, the cathodes of the plurality of light-emitting elements 23 are each electrically connected to a wiring CL. A cathode potential is supplied to the wiring CL.

[0141] In the configuration shown in FIG. 6B, an anode potential can be individually supplied to each of the light-emitting elements 23 to cause light emission.

[0142] The display device shown in FIG. 6C includes a layer 52c having a plurality of light-emitting elements 23 arranged in the column direction and a circuit portion 79c. An anode potential is applied to the anodes of the light-emitting elements 23 from the circuit portion 79c via wiring AL. A cathode potential is applied to the cathodes of the light-emitting elements 23 via wiring CL.

[0143] The display device shown in FIG. 6C can preferably use a configuration in which strip-shaped light-emitting elements 23 having a top surface shape are arranged in one direction.

[0144] FIG. 6D is an example when one light-emitting element 23 is provided. One light-emitting element 23 is provided in layer 52d. An anode potential is applied to the anode of the light-emitting element 23 from the circuit portion 79d via wiring AL, and a cathode potential is applied to the cathode via wiring CL.

[0145] Since the display device shown in FIG. 6D has a configuration including one light-emitting element 23, the circuit portion 79d only needs to control the luminance of the light emission (i.e., the magnitude of the anode potential) and the timing of the light emission, and the circuit configuration can be simplified compared to the above.

[0146] In FIGS. 6A to 6D, the light-emitting element 23 indicated by one circuit symbol can also be composed of a plurality of light-emitting elements. For example, a plurality of light-emitting elements connected in series or in parallel can be regarded as one light-emitting element.

[0147] Here, the period during which the light-emitting element 23 emits light only needs to overlap with the period during which the light-receiving element 22 performs imaging. By shortening the period during which the light-emitting element 23 emits light, that is, by causing the light-emitting element 23 to emit light instantaneously or intermittently instead of continuously, the power consumption of the display device 50 can be suppressed. For example, the period during which the light-emitting element 23 emits light at one time can be set to be approximately the same length as the exposure period by the light-receiving element 22. For example, the period during which the light-emitting element 23 emits light at one time can be 10 μs or more and 10 ms or less, preferably 100 μs or more and 5 ms or less.

[0148] Also, when causing the light-emitting element 23 to emit light instantaneously or intermittently, it is preferable to cause it to emit light strongly. Thereby, since the period required for exposure can be shortened, the light-emitting period of the light-emitting element 23 can be further shortened, and the reliability of the display device can be enhanced. The light emitted by the light-emitting element 23 is preferably light (light with a high radiant emittance) stronger than, for example, when the light-emitting element 21 (any one of the light-emitting elements 21R, 21G, and 21B) emits light at the highest luminance. For example, the light-emitting element 23 has a radiant emittance of 30 mW / m 2 or more, preferably 100 mW / m 2 or more and is preferably configured to be capable of emitting light. The higher the upper limit of the radiant emittance of the light-emitting element 23, the more preferable, but it can be, for example, 3000 W / m 2 or less. Note that the brightness of the light-emitting element 23 may be appropriately adjusted according to the intensity of external light, the reflectance of the subject, and the like.

[0149] [Device Structure] Next, the detailed configurations of the light-emitting element, the light-receiving element, and the light-emitting and light-receiving element that can be used in the display device according to one embodiment of the present invention will be described.

[0150] The light-emitting elements exemplified below can be applied to the light-emitting element 21 exemplified above. Also, the light-receiving elements and the light-emitting and light-receiving elements exemplified below can be applied to the light-receiving element 22 exemplified above. Further, the descriptions of the light-emitting element 23 exemplified above can be applied to the light-emitting elements exemplified below.

[0151] The display device according to one embodiment of the present invention may be any of a top emission type that emits light in a direction opposite to the substrate on which the light-emitting element is formed, a bottom emission type that emits light on the substrate side on which the light-emitting element is formed, and a dual emission type that emits light on both sides.

[0152] In this embodiment, a top emission type display device will be described as an example.

[0153] In this specification and the like, even when describing a configuration having a plurality of elements (such as a light-emitting element and a light-emitting layer), when describing matters common to each element, the alphabet is omitted. For example, when describing matters common to the light-emitting layer 283R and the light-emitting layer 283G, etc., it may be described as the light-emitting layer 283.

[0154] The display device 280A shown in FIG. 7A includes a light-receiving element 270PD, a light-emitting element 270R that emits red (R) light, a light-emitting element 270G that emits green (G) light, and a light-emitting element 270B that emits blue (B) light.

[0155] Each light-emitting element includes a pixel electrode 271, a hole injection layer 281, a hole transport layer 282, a light-emitting layer 283, an electron transport layer 284, an electron injection layer 285, and a common electrode 275 laminated in this order. The light-emitting element 270R includes a light-emitting layer 283R, the light-emitting element 270G includes a light-emitting layer 283G, and the light-emitting element 270B includes a light-emitting layer 283B. The light-emitting layer 283R includes a light-emitting substance that emits red light, the light-emitting layer 283G includes a light-emitting substance that emits green light, and the light-emitting layer 283B includes a light-emitting substance that emits blue light.

[0156] The light-emitting element is an electroluminescent element that emits light toward the common electrode 275 side by applying a voltage between the pixel electrode 271 and the common electrode 275.

[0157] The light-receiving element 270PD includes a pixel electrode 271, a hole injection layer 281, a hole transport layer 282, an active layer 273, an electron transport layer 284, an electron injection layer 285, and a common electrode 275 laminated in this order.

[0158] 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.

[0159] In this embodiment, it will be described that in both the light-emitting element and the light-receiving element, the pixel electrode 271 functions as an anode and the common electrode 275 functions as a cathode. That is, the light-receiving element can detect the light incident on the light-receiving element, generate charges, and extract them as current by applying a reverse bias between the pixel electrode 271 and the common electrode 275 and driving it.

[0160] In the display device of this embodiment, an organic compound is used for the active layer 273 of the light-receiving element 270PD. The light-receiving element 270PD can have the same configuration as the light-emitting element for the layers other than the active layer 273. Therefore, by simply adding a step of forming the active layer 273 to the manufacturing process of the light-emitting element, the light-receiving element 270PD can be formed in parallel with the formation of the light-emitting element. Also, the light-emitting element and the light-receiving element 270PD can be formed on the same substrate. Thus, the light-receiving element 270PD can be incorporated into the display device without significantly increasing the manufacturing process.

[0161] In the display device 280A, an example is shown in which the light-receiving element 270PD and the light-emitting element have the same configuration except that the active layer 273 of the light-receiving element 270PD and the light-emitting layer 283 of the light-emitting element are made separately. However, the configurations of the light-receiving element 270PD and the light-emitting element are not limited to this. The light-receiving element 270PD and the light-emitting element may have layers that are made separately from each other in addition to the active layer 273 and the light-emitting layer 283. The light-receiving element 270PD and the light-emitting element preferably have one or more layers (common layers) that are commonly used. Thereby, the light-receiving element 270PD can be incorporated into the display device without significantly increasing the manufacturing process.

[0162] Of the pixel electrode 271 and the common electrode 275, a conductive film that transmits visible light is used for the electrode on the side where light is extracted. Also, it is preferable to use a conductive film that reflects visible light for the electrode on the side where light is not extracted.

[0163] It is preferable that a microcavity structure is applied to the light-emitting element included in the display device according to the present embodiment. Therefore, it is preferable that one of the pair of electrodes included in the light-emitting element has an electrode (semi-transmissive / semi-reflective electrode) having transmissivity and reflectivity with respect to visible light, and the other has an electrode (reflective electrode) having reflectivity with respect to visible light. By having a microcavity structure in the light-emitting element, light emission obtained from the light-emitting layer can be resonated between both electrodes, and the light emitted from the light-emitting element can be intensified.

[0164] Note that the semi-transmissive / semi-reflective electrode can have a laminated structure of a reflective electrode and an electrode having transmissivity with respect to visible light (also referred to as a transparent electrode).

[0165] The light transmittance of the transparent electrode is set to 40% or more. For example, it is preferable to use an electrode having a visible light (light having a wavelength of 400 nm or more and less than 750 nm) transmittance of 40% or more for the light-emitting element. The visible light reflectivity of the semi-transmissive / semi-reflective electrode is set to 10% or more and 95% or less, preferably 30% or more and 80% or less. The visible light reflectivity of the reflective electrode is set to 40% or more and 100% or less, preferably 70% or more and 100% or less. Also, the resistivity of these electrodes is preferably 1×10 -2 Ωcm or less. Note that when the light-emitting element emits near-infrared light (light having a wavelength of 750 nm or more and 1300 nm or less), it is preferable that the transmittance or reflectivity of near-infrared light of these electrodes satisfies the above numerical range as in the transmittance or reflectivity of visible light.

[0166] The light-emitting element has at least a light-emitting layer 283. As layers other than the light-emitting layer 283, the light-emitting element may further have a layer containing a substance with high hole-injecting property, a substance with high hole-transporting property, a hole-blocking material, a substance with high electron-transporting property, a substance with high electron-injecting property, an electron-blocking material, or a bipolar substance (a substance with high electron-transporting property and high hole-transporting property).

[0167] For example, the light-emitting element and the light-receiving element can share one or more of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. Further, the light-emitting element and the light-receiving element can separately form one or more of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer from each other.

[0168] The hole injection layer is a layer that injects holes from the anode into the hole transport layer and is a layer containing a material with high hole injection properties. As a material with high hole injection properties, an aromatic amine compound or a composite material containing a hole transport material and an acceptor material (electron-accepting material) can be used.

[0169] In the 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 the light-receiving element, the hole transport layer is a layer that transports holes generated based on light incident on the active layer to the anode. The hole transport layer is a layer containing a hole transport material. As the hole transport material, a substance having a hole mobility of 1×10 -6 cm 2 / Vs or more is preferable. In addition, as long as it is a substance with higher hole transportability than electrons, other substances can also be used. As the hole transport material, a hole transport material with high hole transportability such as a π-electron excess type heteroaromatic compound (for example, a carbazole derivative, a thiophene derivative, a furan derivative, etc.) or an aromatic amine (a compound having an aromatic amine skeleton) is preferable.

[0170] 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 based on light incident on the active layer to the cathode. The electron transport layer is a layer containing an electron transport material. As the electron transport material, 1×10 -6 cm 2A substance having an electron mobility of / Vs or higher is preferred. In addition, any other substances can be used as long as they are substances with higher electron transportability than holes. As the electron transport material, in addition to metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, etc., oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other electron transport materials such as π-electron deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds can be used.

[0171] The electron injection layer is a layer that injects electrons from the cathode into the electron transport layer and is a layer containing a material with high electron injection properties. As the material with high electron injection properties, alkali metals, alkaline earth metals, or their compounds can be used. As the material with high electron injection properties, a composite material containing an electron transport material and a donor material (electron donating material) can also be used.

[0172] The light-emitting layer 283 is a layer containing a light-emitting substance. The light-emitting layer 283 can have one or more kinds of light-emitting substances. As the light-emitting substance, substances exhibiting light-emitting colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red can be appropriately used. In addition, a substance that emits near-infrared light can also be used as the light-emitting substance.

[0173] Examples of the light-emitting substance include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0174] Examples of the fluorescent material include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, naphthalene derivatives, etc.

[0175] Examples of the phosphorescent material include an organometallic complex (especially an iridium complex) having a 4H-triazole skeleton, a 1H-triazole skeleton, an imidazole skeleton, a pyrimidine skeleton, a pyrazine skeleton, or a pyridine skeleton, an organometallic complex (especially an iridium complex) having a phenylpyridine derivative having an electron-withdrawing group as a ligand, a platinum complex, a rare earth metal complex, and the like.

[0176] In addition to the light-emitting substance (guest material), the light-emitting layer 283 may have one or more organic compounds (host material, assist material, etc.). As the one or more organic compounds, one or both of a hole-transporting material and an electron-transporting material can be used. Further, a bipolar material or a TADF material may be used as the one or more organic compounds.

[0177] The light-emitting layer 283 preferably has, for example, a phosphorescent material and a hole-transporting material and an electron-transporting material which are a combination likely to form an exciplex. By adopting such a configuration, light emission using ExTET (Exciplex-Triplet Energy Transfer), which is energy transfer from an exciplex to a light-emitting substance (phosphorescent material), can be efficiently obtained. By selecting a combination that forms an exciplex that emits light overlapping with the wavelength of the absorption band on the lowest energy side of the light-emitting substance, energy transfer becomes smooth and light emission can be efficiently obtained. With this configuration, high efficiency, low-voltage driving, and long life of the light-emitting element can be realized simultaneously.

[0178] As a combination of materials that form an exciplex, it is preferable that the HOMO level (highest occupied orbital level) of the hole-transporting material is higher than the HOMO level of the electron-transporting material. It is preferable that the LUMO level (lowest unoccupied orbital level) of the hole-transporting material is higher than the LUMO level of the electron-transporting material. The LUMO level and HOMO level of the material can be derived from the electrochemical characteristics (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV) measurement.

[0179] The formation of an exciplex can be confirmed, for example, by comparing the emission spectrum of a hole transporting material, the emission spectrum of an electron transporting material, and the emission spectrum of a mixed film obtained by mixing these materials, and observing that the emission spectrum of the mixed film is shifted to a longer wavelength (or has a new peak on the longer wavelength side) than the emission spectra of the respective materials. Alternatively, the transient photoluminescence (PL) of a hole transporting material, the transient PL of an electron transporting material, and the transient PL of a mixed film obtained by mixing these materials are compared, and the formation of the exciplex can be confirmed by observing differences in transient responses such as that the transient PL lifetime of the mixed film has a longer lifetime component than the transient PL lifetimes of the respective materials, or the ratio of the delayed component becomes larger. Further, the above-described transient PL may be read as transient electroluminescence (EL). That is, the formation of the exciplex can also be confirmed by comparing the transient EL of a hole transporting material, the transient EL of a material having electron transporting properties, and the transient EL of a mixed film thereof, and observing differences in transient responses.

[0180] The active layer 273 contains a semiconductor. Examples of the semiconductor include inorganic semiconductors such as silicon, and organic semiconductors containing organic compounds. In the present embodiment, an example in which an organic semiconductor is used as the semiconductor included in the active layer 273 is shown. By using an organic semiconductor, the light emitting layer 283 and the active layer 273 can be formed by the same method (for example, vacuum evaporation method), and thus it is preferable because manufacturing apparatuses can be shared.

[0181] Examples of the material of the n-type semiconductor included in the active layer 273 include fullerenes (for example, C 60 、C 70Examples of the electron-accepting organic semiconductor materials include fullerene derivatives and the like. Fullerene has a soccer ball-like shape, and this shape is energetically stable. In fullerene, both the HOMO level and the LUMO level are deep (low). Due to the deep LUMO level, fullerene has extremely high electron-accepting (acceptor) properties. Usually, when π-electron conjugation (resonance) spreads in a plane like benzene, the electron-donating (donor) property increases. However, since fullerene has a spherical shape, despite the large spread of π electrons, its electron-accepting property is high. High electron-accepting property is beneficial for a light-receiving element because it causes efficient charge separation at high speed. C 60 and C 70 both have broad absorption bands in the visible light region. In particular, C 70 is preferable because it has a larger π-electron conjugation system than C 60 and also has a broad absorption band in the long-wavelength region.

[0182] Examples of the materials for the n-type semiconductor also include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, naphthalene derivatives, anthracene derivatives, coumarin derivatives, rhodamine derivatives, triazine derivatives, quinone derivatives, and the like.

[0183] Examples of the materials for the p-type semiconductor included in 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.

[0184] In addition, examples of the p-type semiconductor material include carbazole derivatives, thiophene derivatives, furan derivatives, compounds having an aromatic amine skeleton, and the like. Further, examples of the p-type semiconductor material include naphthalene derivatives, anthracene derivatives, pyrene derivatives, triphenylene derivatives, fluorene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, indole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, indolocarbazole derivatives, porphyrin derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, quinacridone derivatives, polyphenylene vinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, polythiophene derivatives, and the like.

[0185] The HOMO level of the electron-donating organic semiconductor material is preferably shallower (higher) than the HOMO level of the electron-accepting organic semiconductor material. The LUMO level of the electron-donating organic semiconductor material is preferably shallower (higher) than the LUMO level of the electron-accepting organic semiconductor material.

[0186] As the electron-accepting organic semiconductor material, it is preferable to use spherical fullerene, and as the electron-donating organic semiconductor material, it is preferable to use an organic semiconductor material having a shape close to a plane. Molecules with similar shapes tend to aggregate easily. When the same type of molecules aggregate, the energy levels of the molecular orbitals are close to each other, so that the carrier transport property can be enhanced.

[0187] For example, the active layer 273 is preferably formed by co-evaporating an n-type semiconductor and a p-type semiconductor. Alternatively, the active layer 273 may be formed by laminating an n-type semiconductor and a p-type semiconductor.

[0188] For the light-emitting element and the light-receiving element (for example, a common layer and a light-emitting layer), either a low-molecular compound or a high-molecular compound can be used, and an inorganic compound may be included. The layers constituting the light-emitting element and the light-receiving element can be formed by methods such as a vapor deposition method (including a vacuum vapor deposition method), a transfer method, a printing method, an inkjet method, and a coating method, respectively.

[0189] The display device 280B shown in FIG. 7B is different from the display device 280A in that the light receiving element 270PD and the light emitting element 270R have the same configuration.

[0190] The light receiving element 270PD and the light emitting element 270R commonly have the active layer 273 and the light emitting layer 283R.

[0191] Here, it is preferable that the light receiving element 270PD has the same configuration as a light emitting element that emits light with a longer wavelength than the light to be detected. For example, the light receiving element 270PD configured to detect blue light can have the same configuration as one or both of the light emitting element 270R and the light emitting element 270G. For example, the light receiving element 270PD configured to detect green light can have the same configuration as the light emitting element 270R.

[0192] By making the light receiving element 270PD and the light emitting element 270R have the same configuration, the number of film formation steps and the number of masks can be reduced compared to a configuration in which the light receiving element 270PD and the light emitting element 270R have layers made separately from each other. Therefore, the manufacturing process and manufacturing cost of the display device can be reduced.

[0193] Also, by making the light receiving element 270PD and the light emitting element 270R have the same 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 made separately from each other. As a result, the aperture ratio of the pixel can be increased, and the light extraction efficiency of the display device can be increased. Thereby, the lifespan of the light emitting element can be extended. Also, the display device can exhibit high brightness. Also, high definition of the display device is possible.

[0194] The light-emitting layer 283R has a light-emitting material that emits red light. The active layer 273 has an organic compound that absorbs light with a shorter wavelength than red light (for example, one or both of green light and blue light). The active layer 273 preferably has an organic compound that is less likely to absorb red light and absorbs light with a shorter wavelength than red light. As a result, red light is efficiently extracted from the light-emitting element 270R, and the light-receiving element 270PD can detect light with a shorter wavelength than red light with high accuracy.

[0195] In addition, 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 each have an optical adjustment layer with a different thickness.

[0196] The display device 280C shown in FIGS. 8A and 8B includes a light-emitting and light-receiving element 270SR that emits red (R) light and has a light-receiving function, a light-emitting element 270G, and a light-emitting element 270B. The configurations of the light-emitting element 270G and the light-emitting element 270B can be applied to the display device 280A and the like.

[0197] The light-emitting and light-receiving element 270SR includes 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 stacked in this order. The light-emitting and light-receiving element 270SR has the same configuration as the light-emitting element 270R and the light-receiving element 270PD exemplified in the display device 280B.

[0198] In FIG. 8A, a case where the light-emitting and light-receiving element 270SR functions as a light-emitting element is shown. FIG. 8A shows an example in which the light-emitting element 270B emits blue light, the light-emitting element 270G emits green light, and the light-emitting and light-receiving element 270SR emits red light.

[0199] In FIG. 8B, a case where the light-emitting and light-receiving element 270SR functions as a light-receiving element is shown. FIG. 8B shows an example in which the light-emitting and light-receiving element 270SR receives blue light emitted by the light-emitting element 270B and green light emitted by the light-emitting element 270G.

[0200] The light-emitting element 270B, the light-emitting element 270G, and the light-receiving and light-emitting element 270SR each have a pixel electrode 271 and a common electrode 275. In the present embodiment, a case where the pixel electrode 271 functions as an anode and the common electrode 275 functions as a cathode will be described as an example. The light-receiving and light-emitting element 270SR can detect light incident on the light-receiving and light-emitting element 270SR, generate charges, and extract them as a current by driving with a reverse bias applied between the pixel electrode 271 and the common electrode 275.

[0201] The light-receiving and light-emitting element 270SR can be said to have a configuration in which an active layer 273 is added to the light-emitting element. That is, the light-receiving and light-emitting element 270SR can be formed in parallel with the formation of the light-emitting element by simply adding a step of forming the active layer 273 to the manufacturing process of the light-emitting element. Further, the light-emitting element and the light-receiving and light-emitting element can be formed on the same substrate. Therefore, one or both of the imaging function and the sensing function can be imparted to the display unit without significantly increasing the manufacturing process.

[0202] The stacking order of the light-emitting layer 283R and the active layer 273 is not limited. FIGS. 8A and 8B 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 interchanged.

[0203] Further, the light-receiving and light-emitting element may not have at least one of a hole injection layer 281, a hole transport layer 282, an electron transport layer 284, and an electron injection layer 285. Further, the light-receiving and light-emitting element may have other functional layers such as a hole blocking layer and an electron blocking layer.

[0204] In the light-receiving and light-emitting element, a conductive film that transmits visible light is used for the electrode on the side where light is extracted. Further, it is preferable to use a conductive film that reflects visible light for the electrode on the side where light is not extracted.

[0205] Since the functions and materials of the respective layers constituting the light-receiving and light-emitting element are the same as those of the respective layers constituting the light-emitting element and the light-receiving element, detailed description thereof will be omitted.

[0206] FIGS. 8C to 8G show examples of the stacked structure of the light-emitting and light-receiving element.

[0207] The light-emitting and light-receiving element shown in FIG. 8C 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.

[0208] FIG. 8C shows an example in which the light-emitting layer 283R is provided on the hole transport layer 282 and the active layer 273 is stacked on the light-emitting layer 283R.

[0209] As shown in FIGS. 8A to 8C, the active layer 273 and the light-emitting layer 283R may be in contact with each other.

[0210] Further, it is preferable that a buffer layer is provided between the active layer 273 and the light-emitting layer 283R. At this time, the buffer layer preferably has hole transportability and electron transportability. For example, it is preferable to use a bipolar substance for the buffer layer. Alternatively, at least one layer of a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole blocking layer, and an electron blocking layer or the like can be used as the buffer layer. FIG. 8D shows an example in which the hole transport layer 282 is used as the buffer layer.

[0211] By providing a buffer layer between the active layer 273 and the light-emitting layer 283R, it is possible to suppress the transfer of excitation energy from the light-emitting layer 283R to the active layer 273. Also, the optical path length (cavity length) of the microcavity structure can be adjusted using the buffer layer. Therefore, a high luminous efficiency can be obtained from the light-emitting and light-receiving element having a buffer layer between the active layer 273 and the light-emitting layer 283R.

[0212] FIG. 8E shows an example having a stacked structure in which a hole transport layer 282-1, an active layer 273, a hole transport layer 282-2, and a light-emitting layer 283R are stacked in this order on a hole injection layer 281. The hole transport layer 282-2 functions as a buffer layer. The hole transport layer 282-1 and the hole transport layer 281-2 may contain the same material or different materials. Further, instead of the hole transport layer 281-2, a layer that can be used for the buffer layer described above may be used. Also, the positions of the active layer 273 and the light-emitting layer 283R may be interchanged.

[0213] The light-emitting and receiving element shown in FIG. 8F is different from the light-emitting and receiving element shown in FIG. 8A in that it does not have a hole transport layer 282. Thus, the light-emitting and receiving element may not have at least one of a hole injection layer 281, a hole transport layer 282, an electron transport layer 284, and an electron injection layer 285. Further, the light-emitting and receiving element may have other functional layers such as a hole blocking layer and an electron blocking layer.

[0214] The light-emitting and receiving element shown in FIG. 8G is different from the light-emitting and receiving element shown in FIG. 8A in that it does not have an active layer 273 and a light-emitting layer 283R, but has a layer 289 that serves as both a light-emitting layer and an active layer.

[0215] As the layer 289 that serves as both a light-emitting layer and an active layer, for example, a layer containing three materials, namely, an n-type semiconductor that can be used for the active layer 273, a p-type semiconductor that can be used for the active layer 273, and a light-emitting substance that can be used for the light-emitting layer 283R, can be used.

[0216] Note that it is preferable that the absorption band on the lowest energy side of the absorption spectrum of the mixed material of the n-type semiconductor and the p-type semiconductor does not overlap with the maximum peak of the emission spectrum (PL spectrum) of the light-emitting substance, and it is more preferable that they are sufficiently separated.

[0217] [Configuration Example 4 of Display Device] Hereinafter, a more specific configuration of a display device according to an aspect of the present invention will be described.

[0218] FIG. 9 shows a perspective view of the display device 200, and FIG. 10A shows a cross-sectional view of the display device 200.

[0219] The display device 200 has a configuration in which a substrate 151 and a substrate 152 are bonded together. In FIG. 9, the substrate 152 is indicated by a dashed line.

[0220] The display device 200 includes a display unit 262, a circuit 264, a wiring 265, etc. FIG. 9 shows an example in which an IC (integrated circuit) 274 and an FPC 272 are mounted on the display device 200. Therefore, the configuration shown in FIG. 9 can also be referred to as a display module having the display device 200, the IC, and the FPC.

[0221] As the circuit 264, for example, a scanning line driving circuit can be used.

[0222] The wiring 265 has a function of supplying signals and power to the display unit 262 and the circuit 264. The signals and power are input to the wiring 265 from the outside via the FPC 272 or input to the wiring 265 from the IC 274.

[0223] FIG. 9 shows an example in which an IC 274 is provided on the substrate 151 by a COG (Chip On Glass) method, a COF (Chip On Film) method, or the like. As the IC 274, for example, an IC having a scanning line driving circuit or a signal line driving circuit can be applied. Note that the display device 200 and the display module may be configured without an IC. Also, the IC may be mounted on the FPC by a COF method or the like.

[0224] FIG. 10A shows an example of a cross-section when a part of the region including the FPC 272, a part of the region including the circuit 264, a part of the region including the display unit 262, and a part of the region including the end portion of the display device 200 shown in FIG. 9 are each cut.

[0225] The display device 200 shown in Fig. 10A has, between a substrate 151 and a substrate 152, a transistor 208, a transistor 209, a transistor 210, a light-emitting element 190, a light-receiving element 110, a light-emitting element 160, and the like.

[0226] The transistor 208, the transistor 209, and the transistor 210 are all formed on the substrate 151. These transistors can be fabricated by the same material and the same process.

[0227] The transistor 208, the transistor 209, and the transistor 210 have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, a semiconductor layer having a channel formation region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 that functions as a gate insulating layer, a conductive layer 223 that functions as a gate, and an insulating layer 215 that covers the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel formation region 231i. The insulating layer 225 is located between the conductive layer 223 and the channel formation region 231i.

[0228] The conductive layer 222a and the conductive layer 222b are respectively connected to the low-resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215. Of the conductive layer 222a and the conductive layer 222b, one functions as a source and the other functions as a drain.

[0229] The structure of the transistor included in the display device of this embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, an inverse staggered transistor, or the like can be used. Also, either a top-gate type or a bottom-gate type transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0230] For transistors 208, 209, and 210, a configuration is applied in which a semiconductor layer in which a channel is formed is sandwiched between two gates. The transistors may be driven by connecting the two gates and supplying the same signal thereto. Alternatively, the threshold voltage of the transistors may be controlled by applying a potential for controlling the threshold voltage to one of the two gates and a potential for driving to the other.

[0231] The crystallinity of the semiconductor material used for the transistors is not particularly limited, and any of an amorphous semiconductor, a single-crystalline semiconductor, or a semiconductor having crystallinity other than single crystal (microcrystalline semiconductor, polycrystalline semiconductor, or semiconductor having a crystal region in part) may be used. It is preferable to use a single-crystalline semiconductor or a semiconductor having crystallinity because deterioration of transistor characteristics can be suppressed.

[0232] The semiconductor layer of the transistor preferably has a metal oxide (also referred to as an oxide semiconductor). Alternatively, the semiconductor layer of the transistor may have silicon. Examples of silicon include amorphous silicon, crystalline silicon (such as low-temperature polysilicon, single-crystalline silicon).

[0233] The semiconductor layer preferably has, for example, indium, M (where M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more selected from aluminum, gallium, yttrium, and tin.

[0234] In particular, it is preferable to use an oxide (also denoted as IGZO) containing indium (In), gallium (Ga), and zinc (Zn) as the semiconductor layer.

[0235] When the semiconductor layer is an In-M-Zn oxide, the sputtering target used to form the In-M-Zn oxide preferably has an atomic ratio of In that is equal to or greater than the atomic ratio of M. Examples of the atomic ratios of the metal elements in such a sputtering target include In:M:Zn = 1:1:1, In:M:Zn = 1:1:1.2, In:M:Zn = 2:1:3, In:M:Zn = 3:1:2, In:M:Zn = 4:2:3, In:M:Zn = 4:2:4.1, In:M:Zn = 5:1:3, In:M:Zn = 5:1:6, In:M:Zn = 5:1:7, In:M:Zn = 5:1:8, In:M:Zn = 10:1:3, In:M:Zn = 6:1:6, In:M:Zn = 5:2:5, and the like.

[0236] As the sputtering target, it is preferable to use a target containing polycrystalline oxide because it facilitates the formation of a semiconductor layer having crystallinity. Note that the atomic ratio of the semiconductor layer to be formed includes fluctuations of plus or minus 40% of the atomic ratio of the metal elements contained in the above sputtering target. For example, when the composition of the sputtering target used for the semiconductor layer is In:Ga:Zn = 4:2:4.1 [atomic ratio], the composition of the semiconductor layer to be formed may be in the vicinity of In:Ga:Zn = 4:2:3 [atomic ratio].

[0237] When the atomic ratio is described as In:Ga:Zn = 4:2:3 or in the vicinity thereof, when In is 4, it includes the case where Ga is 1 or more and 3 or less, and Zn is 2 or more and 4 or less. When the atomic ratio is described as In:Ga:Zn = 5:1:6 or in the vicinity thereof, when In is 5, it includes the case where Ga is greater than 0.1 and 2 or less, and Zn is 5 or more and 7 or less. When the atomic ratio is described as In:Ga:Zn = 1:1:1 or in the vicinity thereof, when In is 1, it includes the case where Ga is greater than 0.1 and 2 or less, and Zn is greater than 0.1 and 2 or less.

[0238] The transistors included in circuit 264 and the transistors included in display unit 262 may have the same structure or different structures. The structures of the multiple transistors included in circuit 264 may all be the same or there may be two or more types. Similarly, the structures of the multiple transistors included in display unit 262 may all be the same or there may be two or more types.

[0239] Insulating layer 214 is provided to cover the transistor and has the function of a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistor are not limited, and each may be a single layer or two or more layers.

[0240] It is preferable to use a material in which impurities such as water or hydrogen hardly diffuse in at least one of the insulating layers covering the transistor. Thereby, the insulating layer can function as a barrier layer. With such a configuration, it is possible to effectively suppress the diffusion of external impurities into the transistor and improve the reliability of the display device.

[0241] FIG. 10A shows an example in which insulating layer 225 covers the upper surface and the side surface of the semiconductor layer. On the other hand, in transistor 202 shown in FIG. 10B, insulating layer 225 overlaps channel formation region 231i of semiconductor layer 231 and does not overlap low resistance region 231n. For example, the structure shown in FIG. 10B can be fabricated by processing insulating layer 225 using conductive layer 223 as a mask. In FIG. 10B, insulating layer 215 is provided to cover insulating layer 225 and conductive layer 223, and conductive layer 222a and conductive layer 222b are respectively connected to low resistance region 231n through the opening of insulating layer 215. Further, an insulating layer 218 covering the transistor may be provided.

[0242] As the insulating layer 211, the insulating layer 225, and the insulating layer 215, it is preferable to use an inorganic insulating film respectively. As the inorganic insulating film, for example, a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, an aluminum nitride film, etc. can be used. Further, a hafnium oxide film, a yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, a neodymium oxide film, etc. may be used. Also, two or more of the above-mentioned insulating films may be laminated and used.

[0243] Here, the organic insulating film often has lower barrier properties than the inorganic insulating film. Therefore, it is preferable that the organic insulating film has an opening near the end of the display device 200. Thereby, it is possible to suppress the diffusion of impurities from the end of the display device 200 through the organic insulating film. Or, the organic insulating film may be formed such that the end of the organic insulating film is located inside the end of the display device 200 so that the organic insulating film is not exposed at the end of the display device 200.

[0244] An organic insulating film is suitable for the insulating layer 214 that functions as a planarization layer. Examples of the material that can be used for the organic insulating film include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimide amide resin, siloxane resin, benzocyclobutene-based resin, phenol resin, and precursors of these resins.

[0245] In the region 228 shown in FIG. 10A, an opening is formed in the insulating layer 214. Thereby, even when an organic insulating film is used for the insulating layer 214, it is possible to suppress the diffusion of impurities from the outside to the display unit 262 through the insulating layer 214. Therefore, the reliability of the display device 200 can be improved.

[0246] The light-emitting element 190 has a stacked structure in which a pixel electrode 191, a common layer 114, a light-emitting layer 196, a common layer 115, and a common electrode 113 are stacked in this order from the insulating layer 214 side. The pixel electrode 191 of the light-emitting element 190 is electrically connected to one of a pair of low-resistance regions 231n of the transistor 208 via a conductive layer 222b. The transistor 208 has a function of controlling the driving of the light-emitting element 190. The end portion of the pixel electrode 191 is covered by a partition wall 216. The pixel electrode 191 contains a material that reflects visible light, and the common electrode 113 contains a material that transmits visible light.

[0247] The light-receiving element 110 has a stacked structure in which a pixel electrode 111, a common layer 114, an active layer 116, a common layer 115, and a common electrode 113 are stacked in this order from the insulating layer 214 side. The pixel electrode 111 of the light-receiving element 110 is electrically connected to the other of a pair of low-resistance regions 231n of the transistor 209 via a conductive layer 222b. The end portion of the pixel electrode 111 is covered by a partition wall 216. The pixel electrode 111 contains a material that reflects visible light and infrared light, and the common electrode 113 contains a material that transmits visible light and infrared light.

[0248] The light emitted by the light-emitting element 190 is emitted toward the substrate 152 side. Further, light is incident on the light-receiving element 110 through the substrate 152. It is preferable to use a material having high transmittance for visible light and infrared light for the substrate 152.

[0249] The pixel electrode 111 and the pixel electrode 191 can be manufactured using the same material and the same process. The common layer 114, the common layer 115, and the common electrode 113 are used for both the light-receiving element 110 and the light-emitting element 190. The light-receiving element 110 and the light-emitting element 190 can have the same configuration except that the configurations of the active layer 116 and the light-emitting layer 196 are different. As a result, the light-receiving element 110 can be incorporated into the display device 200 without significantly increasing the manufacturing process.

[0250] Further, an inorganic insulating layer 195a, an organic insulating layer 195b, and an inorganic insulating layer 195c are laminated and provided so as to cover the light receiving element 110 and the light emitting element 190. Further, a light shielding layer 145 and a light emitting element 160 are laminated and provided on the inorganic insulating layer 195c. The light shielding layer 145 and the light emitting element 160 are provided at positions that do not overlap with the light receiving region of the light receiving element 110 and the light emitting region of the light emitting element 190.

[0251] In the display device 200, the organic insulating layer 195b corresponds to the resin layer 141. Note that, instead of providing the inorganic insulating layer 195c, a configuration may be adopted in which a part of the organic insulating layer 195b and a part of the resin layer 142 are in contact with each other.

[0252] The end of the inorganic insulating layer 195a and the end of the inorganic insulating layer 195c extend outside the end of the organic insulating layer 195b and are in contact with each other. The inorganic insulating layer 195a is in contact with an insulating layer 215 (inorganic insulating layer) through an opening of an insulating layer 214 (organic insulating layer). As a result, the light receiving element 110 and the light emitting element 190 can be surrounded by the insulating layer 215 and the protective layer 195, so that the reliability of the light receiving element 110 and the light emitting element 190 can be improved.

[0253] Thus, the protective layer 195 may have a laminated structure of an organic insulating film and an inorganic insulating film. At this time, it is preferable that the end of the inorganic insulating film extends outside the end of the organic insulating film.

[0254] The light shielding layer 145 has openings at positions overlapping the light receiving element 110 and at positions overlapping the light emitting element 190. By providing the light shielding layer 145, the range in which the light receiving element 110 detects light can be controlled. Further, by having the light shielding layer 145, it is possible to suppress light from directly entering the light receiving element 110 from the light emitting element 190 and the light emitting element 160. Therefore, a sensor with less noise and high sensitivity can be realized.

[0255] The light emitting element 160, the insulating layer 217, etc. are provided on the substrate 152 side. The light emitting element 160 is a bottom emission type light emitting element that emits light toward the formed surface side.

[0256] The light-emitting element 160 has a stacked structure in which an electrode 161, a buffer layer 164, a light-emitting layer 166, a buffer layer 165, and an electrode 163 are stacked in this order from the substrate 152 side. The end of the electrode 161 is covered by an insulating layer 217. The electrode 161 contains a material that transmits infrared light, and the electrode 163 contains a material that reflects visible light and infrared light.

[0257] The buffer layer 164, the light-emitting layer 166, and the buffer layer 165 have an island-shaped upper surface shape. Also, the electrode 163 is provided so as to cover the buffer layer 164, the light-emitting layer 166, and the buffer layer 165. The buffer layer 164, the light-emitting layer 166, the buffer layer 165, and the electrode 163 are provided at positions that do not overlap with the light-receiving region of the light-receiving element 110 and the light-emitting region of the light-emitting element 190.

[0258] FIG. 10A shows an example in which a passive matrix method or a segment method can be applied as a driving method for the light-emitting element 160. At this time, the electrode 161 and the electrode 163 are provided in common for a plurality of light-emitting elements 160, respectively.

[0259] In addition, when an active matrix method is applied as the driving method for the light-emitting element 160, a transistor can be provided between the light-emitting element 160 and the substrate 152. In that case, similar to the light-emitting element 190, the electrode 161 can be formed in an island-shaped upper surface shape and electrically connected to one of the source and drain of the transistor. At this time, the electrode 161 functions as a pixel electrode. Regarding the configuration between the electrode 161 and the substrate 152, the light-emitting element 190, the transistor 208, and the surrounding layer structure can be adopted.

[0260] A resin layer 142 is provided so as to cover the insulating layer 217 and the light-emitting element 160. Also, the resin layer 142 is provided so as to cover a light-shielding layer 145 provided on the substrate 151 side. The resin layer 142 functions as an adhesive layer for bonding the substrate 151 and the substrate 152.

[0261] In the region of the substrate 151 where the substrate 152 does not overlap, a connection portion 204 is provided. In the connection portion 204, the wiring 265 is electrically connected to the FPC 272 via the conductive layer 266 and the connection layer 242. On the upper surface of the connection portion 204, the conductive layer 266 obtained by processing the same conductive film as the pixel electrode 191 is exposed. Thereby, the connection portion 204 and the FPC 272 can be electrically connected via the connection layer 242.

[0262] Various optical members can be arranged outside the substrate 152. Examples of the optical members include a polarizing plate, a retardation plate, a light diffusion layer (such as a diffusion film), an antireflection layer, and a condensing film. Further, outside the substrate 152, an antistatic film for suppressing dust adhesion, a water-repellent film for making dirt less likely to adhere, a hard coat film for suppressing the occurrence of scratches during use, a shock absorption layer, etc. may be arranged.

[0263] For the substrate 151 and the substrate 152, glass, quartz, ceramic, sapphire, resin, etc. can be used respectively. When a flexible material is used for the substrate 151 and the substrate 152, the flexibility of the display device can be enhanced.

[0264] As the adhesive layer, various curable adhesives such as a photocurable adhesive such as an ultraviolet curable type, a reaction curable adhesive, a thermosetting adhesive, and an anaerobic adhesive can be used. Examples of these adhesives include epoxy resin, acrylic resin, silicone resin, phenol resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin, EVA (ethylene vinyl acetate) resin, etc. In particular, a material with low moisture permeability such as epoxy resin is preferable. Also, a two-component mixed resin may be used. Also, an adhesive sheet or the like may be used.

[0265] As the connection layer 242, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), etc. can be used.

[0266] Here, a top-emission type light-emitting element was applied as the light-emitting element 190, and a bottom-emission type light-emitting element was applied as the light-emitting element 160. However, light-emitting elements include top-emission type, bottom-emission type, dual-emission type, and the like. For the electrode on the side where light is extracted, a conductive film that transmits visible light is used. Further, it is preferable to use a conductive film that reflects visible light for the electrode on the side where light is not extracted.

[0267] As materials that can be used for the gate, source, and drain of a transistor, as well as various wirings and electrodes constituting a display device, etc., conductive layers include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, and alloys having such metals as the main component, etc. Films containing these materials can be used as a single layer or in a laminated structure.

[0268] Further, as a conductive material having translucency, 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, or alloy materials containing the metal materials can be used. Alternatively, nitrides of the metal materials (for example, titanium nitride) can also be used. When using metal materials, alloy materials (or their nitrides), it is preferable to make them thin enough to have translucency. Also, a laminated film of the above materials can be used as a conductive layer. For example, using a laminated film of an alloy of silver and magnesium and indium tin oxide is preferable because it can enhance conductivity. These can also be used for conductive layers such as various wirings and electrodes constituting a display device, or conductive layers (such as pixel electrodes or common electrodes) of display elements.

[0269] Examples of insulating materials that can be used for each insulating layer include resins such as acrylic resin and epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon nitride oxynitride, silicon nitride, aluminum oxide, and hafnium oxide.

[0270] [Regarding Metal Oxides] Hereinafter, metal oxides applicable to the semiconductor layer will be described.

[0271] In this specification and the like, metal oxides containing nitrogen may sometimes be collectively referred to as metal oxides. Also, metal oxides containing nitrogen may be referred to as metal oxynitrides. For example, metal oxides containing nitrogen such as zinc oxynitride (ZnON) may be used for the semiconductor layer.

[0272] In this specification and the like, there may be descriptions of CAAC (c-axis aligned crystal) and CAC (Cloud-Aligned Composite). CAAC represents an example of a crystal structure, and CAC represents an example of the configuration of a function or material.

[0273] For example, CAC (Cloud-Aligned Composite)-OS (Oxide Semiconductor) can be used for the semiconductor layer.

[0274] CAC-OS or CAC-metal oxide has a conductive function in part of the material and an insulating function in part of the material, and has a semiconductor function as a whole. When CAC-OS or CAC-metal oxide is used for the semiconductor layer of a transistor, the conductive function is the function of flowing electrons (or holes) serving as carriers, and the insulating function is the function of not flowing electrons serving as carriers. By causing the conductive function and the insulating function to act complementarily, respectively, a switching function (On / Off function) can be imparted to CAC-OS or CAC-metal oxide. In CAC-OS or CAC-metal oxide, by separating the respective functions, both functions can be enhanced to the maximum extent.

[0275] Also, CAC-OS or CAC-metal oxide has a conductive region and an insulating region. The conductive region has the above-described conductive function, and the insulating region has the above-described insulating function. Also, in the material, the conductive region and the insulating region may be separated at the nanoparticle level. Also, the conductive region and the insulating region may be unevenly distributed in the material, respectively. Also, the conductive region may be observed to be blurred at the periphery and connected in a cloud shape.

[0276] Also, in CAC-OS or CAC-metal oxide, the conductive region and the insulating region may be dispersed in the material with sizes of 0.5 nm or more and 10 nm or less, preferably 0.5 nm or more and 3 nm or less, respectively.

[0277] In addition, CAC-OS or CAC-metal oxide is composed of components having different band gaps. For example, CAC-OS or CAC-metal oxide is composed of a component having a wide band gap due to an insulating region and a component having a narrow band gap due to a conductive region. In such a configuration, when carriers flow, the carriers mainly flow in the component having the narrow band gap. Further, the component having the narrow band gap acts complementarily to the component having the wide band gap, and carriers also flow in the component having the wide band gap in conjunction with the component having the narrow band gap. Therefore, when the above CAC-OS or CAC-metal oxide is used for the channel formation region of a transistor, a high current driving force, that is, a large on-current, and a high field-effect mobility can be obtained in the on state of the transistor.

[0278] That is, CAC-OS or CAC-metal oxide can also be referred to as a matrix composite or a metal matrix composite.

[0279] Oxide semiconductors (metal oxides) can be divided into single-crystalline oxide semiconductors and other non-single-crystalline oxide semiconductors. Examples of non-single-crystalline oxide semiconductors include CAAC-OS (c-axis aligned crystalline oxide semiconductor), polycrystalline oxide semiconductors, nc-OS (nanocrystalline oxide semiconductor), pseudo-amorphous oxide semiconductors (a-like OS: amorphous-like oxide semiconductor), and amorphous oxide semiconductors.

[0280] CAAC-OS has a c-axis orientation, and a plurality of nanocrystals are connected in the a-b plane direction, resulting in a crystal structure having strain. Note that the strain refers to a portion where the orientation of the lattice arrangement changes between a region where the lattice arrangements are aligned and another region where the lattice arrangements are aligned in the region where the plurality of nanocrystals are connected.

[0281] The nanocrystals are based on a hexagon, but are not necessarily regular hexagons and may be non-regular hexagons. Also, in terms of strain, there may be lattice arrays such as pentagons and heptagons. In CAAC-OS, it is difficult to confirm a distinct grain boundary (also referred to as a grain boundary) even in the vicinity of strain. That is, it can be seen that the formation of grain boundaries is suppressed by the strain of the lattice array. This is because CAAC-OS can tolerate strain due to the fact that the arrangement of oxygen atoms is not dense in the a-b plane direction, or the interatomic bond distance changes due to substitution of a metal element.

[0282] Also, CAAC-OS tends to have a layered crystal structure (also referred to as a layered structure) in which a layer containing indium and oxygen (hereinafter, In layer) and a layer containing element M, zinc, and oxygen (hereinafter, (M,Zn) layer) are laminated. Note that indium and element M are mutually substitutable, and when element M in the (M,Zn) layer is substituted with indium, it can also be represented as an (In,M,Zn) layer. Also, when indium in the In layer is substituted with element M, it can also be represented as an (In,M) layer.

[0283] CAAC-OS is a highly crystalline metal oxide. On the other hand, since it is difficult to confirm a distinct grain boundary in CAAC-OS, it can be said that a decrease in electron mobility due to grain boundaries is unlikely to occur. Also, since the crystallinity of a metal oxide may decrease due to contamination with impurities or generation of defects, CAAC-OS can also be said to be a metal oxide with few impurities and defects (such as oxygen vacancies (also referred to as V O :oxygen vacancy). Therefore, the physical properties of the metal oxide having CAAC-OS are stable. Therefore, the metal oxide having CAAC-OS is heat-resistant and highly reliable.

[0284] nc-OS has periodicity in the atomic arrangement in a minute region (for example, a region of 1 nm or more and 10 nm or less, particularly a region of 1 nm or more and 3 nm or less). Also, nc-OS has no regularity in the crystal orientation between different nanocrystals. Therefore, no orientation is observed in the entire film. Thus, depending on the analysis method, nc-OS may not be distinguishable from a-like OS or an amorphous oxide semiconductor.

[0285] Note that indium-gallium-zinc oxide (hereinafter, IGZO), which is a kind of metal oxide having indium, gallium, and zinc, may take a stable structure by using the above-described nanocrystals. In particular, since IGZO has a tendency to be difficult to grow crystals in the air, it may be structurally more stable to use crystals smaller than large crystals (here, crystals of several mm or crystals of several cm), for example, the above-described nanocrystals.

[0286] a-like OS is a metal oxide having a structure between nc-OS and an amorphous oxide semiconductor. a-like OS has a loose or low-density region. That is, a-like OS has lower crystallinity than nc-OS and CAAC-OS.

[0287] Oxide semiconductors (metal oxides) have various structures and each has different characteristics. The oxide semiconductor according to one embodiment of the present invention may have two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, a-like OS, nc-OS, and CAAC-OS.

[0288] The metal oxide film functioning as a semiconductor layer can be formed using either one or both of an inert gas and an oxygen gas. Note that there is no particular limitation on the flow rate ratio (oxygen partial pressure) of oxygen during the formation of the metal oxide film. However, when obtaining a transistor having a high field-effect mobility, the flow rate ratio (oxygen partial pressure) of oxygen during the formation of the metal oxide film is preferably 0% or more and 30% or less, more preferably 5% or more and 30% or less, and still more preferably 7% or more and 15% or less.

[0289] The metal oxide preferably has an energy gap of 2 eV or more, more preferably 2.5 eV or more, and even more preferably 3 eV or more. By using a metal oxide with a wide energy gap in this way, the off-current of the transistor can be reduced.

[0290] The substrate temperature during the formation of the metal oxide film is preferably 350°C or lower, more preferably room temperature or higher and 200°C or lower, and even more preferably room temperature or higher and 130°C or lower. When the substrate temperature during the formation of the metal oxide film is room temperature, productivity can be increased, which is preferable.

[0291] The metal oxide film can be formed by a sputtering method. In addition, for example, a PLD method, a PECVD method, a thermal CVD method, an ALD method, a vacuum evaporation method, etc. may also be used.

[0292] The above is the description of the metal oxide.

[0293] The display device of this embodiment has a light receiving element and a light emitting element in the display unit, and the display unit has both a function of displaying an image and a function of detecting light. Thereby, compared with the case where a sensor is provided outside the display unit or outside the display device, miniaturization and weight reduction of the electronic device can be achieved. In addition, in combination with a sensor provided outside the display unit or outside the display device, a more multifunctional electronic device can also be realized.

[0294] The light-receiving element can have at least one layer other than the active layer configured in common with the light-emitting element (EL element). Furthermore, the light-receiving element can also have all layers other than the active layer configured in common with the light-emitting element (EL element). For example, by simply adding a step of forming an active layer to the manufacturing process of the light-emitting element, the light-emitting element and the light-receiving element can be formed on the same substrate. Also, the pixel electrode and the common electrode of the light-receiving element and the light-emitting element can be formed of the same material and in the same process, respectively. Moreover, by manufacturing the circuit electrically connected to the light-receiving element and the circuit electrically connected to the light-emitting element using the same material and in the same process, the manufacturing process of the display device can be simplified. Thus, a display device with high convenience incorporating a light-receiving element can be manufactured without complicated processes.

[0295] At least a part of the configuration examples illustrated in this embodiment and the corresponding drawings, etc. can be appropriately combined with other configuration examples, drawings, etc.

[0296] This embodiment can be implemented by appropriately combining at least a part of it with other embodiments described in this specification.

[0297] (Embodiment 2) In this embodiment, an electronic device according to an aspect of the present invention will be described.

[0298] [Configuration Example of Electronic Device] A display device according to an aspect of the present invention can acquire various biological information using infrared light and visible light. Such biological information can be used for both user personal authentication and healthcare applications.

[0299] Among the biological information that can be acquired using a display device according to an aspect of the present invention, the biological information that can be used for personal authentication typically includes fingerprints, palm prints, veins, irises, etc. These biological information can be acquired by visible light or infrared light. In particular, information on veins and irises is preferably acquired by infrared light.

[0300] Among the biological information that can be obtained using the display device according to one aspect of the present invention, examples of biological information that can be used for healthcare applications include pulse wave, blood glucose level, oxygen saturation, triglyceride concentration, and the like.

[0301] Furthermore, it is preferable to provide means for acquiring other biological information in the electronic device on which the display device is mounted. For example, in addition to biological information inside the body such as electrocardiogram, blood pressure, and body temperature, there is also surface biological information such as facial expression, complexion, and pupil. Also, information such as the number of steps, exercise intensity, elevation difference of movement, and diet (intake calories or nutrients, etc.) is also important information for healthcare. By using multiple pieces of biological information and the like, comprehensive physical condition management becomes possible, leading not only to daily health management but also to early detection of injuries and illnesses.

[0302] For example, blood pressure can be calculated from the electrocardiogram and the time difference (the length of the pulse wave propagation time) between two pulsations of the pulse wave. When the blood pressure is high, the pulse wave propagation time is short, and conversely, when the blood pressure is low, the pulse wave propagation time is long. Also, from the relationship between the heart rate and blood pressure calculated from the electrocardiogram and the pulse wave, the physical condition of the user can be estimated. For example, if both the heart rate and blood pressure are high, it can be estimated that the user is in a state of tension or excitement, and conversely, if both the heart rate and blood pressure are low, it can be estimated that the user is in a relaxed state. Also, if the state of low blood pressure and high heart rate continues, there may be a possibility of heart disease or the like.

[0303] Since the user can check at any time the biological information measured by the electronic device or their own physical condition estimated based on such information, their health awareness is improved. As a result, it can also serve as an opportunity to review daily habits such as avoiding overeating and drinking, paying attention to appropriate exercise, or performing physical condition management, or to receive a medical examination by a medical institution if necessary.

[0304] 〔Configuration Example 1〕 FIG. 11A shows a schematic diagram of an electronic device 80. The electronic device 80 can be used as a smartphone. The electronic device 80 includes at least a housing 82, a display unit 81a, and a display unit 81b. The display unit 81a functions as a main display surface, the display unit 81b functions as a sub-display surface, and has a curved shape along the side surface of the housing 82. A display device according to an aspect of the present invention is applied to the display unit 81a and the display unit 81b.

[0305] As shown in FIG. 11A, the display unit 81b is provided at a position where the finger 60 naturally touches when the user grips the electronic device 80 with the hand 60a. At this time, the electronic device 80 can acquire the fingerprint of the finger 60 touching the display unit 81b and execute fingerprint authentication. Thereby, the authentication operation can be executed simultaneously with the operation of holding the electronic device 80 without the user being aware of it. Therefore, when the user picks up the electronic device 80 and looks at the screen, the authentication is already completed and the user is in the logged-in state, and the electronic device can be used immediately, so that the electronic device can have high security and high convenience.

[0306] Also, as shown in FIG. 11B, by touching the finger 60 on the display unit 81a, biometric information of the user can be acquired from the finger 60. For example, imaging of vein shapes and imaging of arterioles can be performed, and various biometric information such as pulse or oxygen concentration can be acquired from the imaged information.

[0307] Note that, as shown in FIG. 11C, by touching the finger 60 along the display unit 81b, similar biometric information can also be acquired by the display unit 81b.

[0308] The acquisition of biometric information can be performed, for example, when the user executes an application for acquisition and management of biometric information. By the application, the electronic device 80 can recognize that the finger 60 touches the display unit 81a or the display unit 81b and execute imaging. Also, from the captured image, the above-described biometric information can be acquired, and data storage or management can be performed.

[0309] The electronic device 80a shown in FIG. 12 has a display unit 81c in addition to the display units 81a and 81b. The display unit 81c is located on the side opposite to the display unit 81b with the display unit 81a in between.

[0310] As shown in FIG. 12, when the user holds the electronic device 80a with the hand 60a, the display unit 81c is provided at a position where at least one of the index finger, middle finger, ring finger, and little finger among the five fingers naturally touches. Also, the display unit 81b is provided at a position where the thumb naturally touches. The display unit 81b and the display unit 81c can each execute fingerprint imaging. Thereby, since fingerprint authentication can be executed using the fingerprints of a plurality of fingertips, it is preferable because more accurate authentication can be executed.

[0311] Moreover, since the electronic device 80a has a bilaterally symmetric configuration, it can correspond to both hands regardless of whether it is the right hand or the left hand, which is preferable.

[0312] 〔Configuration Example 2〕 FIG. 13 shows a schematic diagram of the electronic device 80b. The electronic device 80b can be used as a tablet terminal. The electronic device 80b includes at least a housing 82, a display unit 81a, and a display unit 81b. The display device according to an aspect of the present invention is applied to the display units 81a and 81b.

[0313] The electronic device 80b can execute personal authentication and acquire the biological information of the user by the user holding the hand 60a over or in contact with the display unit 81.

[0314] When the user's hand 60a is placed on the display unit 81, the electronic device 80b can recognize its shape. Then, it executes acquisition of biometric information suitable for each region corresponding to each part of the hand 60a. For example, in the region 85a corresponding to the fingertip of the hand 60a, imaging of fingerprint shape and vein shape can be executed. Also, in the region 85b corresponding to the finger pad, imaging of vein shape, imaging of arterioles, etc. can be executed. Further, in the region 85c corresponding to the palm, imaging of palmprint, imaging of veins, imaging of arterioles, imaging of dermis, etc. can be executed. Images of fingerprints, palmprints, and veins can be used for personal authentication. Also, images of arterioles, veins, or dermis can be used for acquisition of biometric information.

[0315] Also, when acquiring biometric information, an image imitating the shape of a hand may be displayed on the display unit 81, and the user may be prompted to place the hand 60a in accordance with the image. Thereby, the recognition accuracy of the shape of the hand 60a can be improved.

[0316] In this way, every time personal authentication for starting up the electronic device 80b is executed, the biometric information of the user can be acquired. Thereby, since biometric information can be continuously accumulated without the user being aware of it, continuous health management can be performed. Also, it is preferable because application software for health management or the like does not need to be executed by the user each time, and there is no fear that acquisition and update of biometric information will be interrupted.

[0317] [Configuration example of the system] According to one aspect of the present invention, various biometric information can be acquired regularly and continuously, and these biometric information can be used for personal authentication, health management, etc.

[0318] For example, biometric information obtained by using visible light and infrared rays includes fingerprints, palmprints, vein shapes, pulse waves, respiration rate, pulse, oxygen saturation, blood glucose level, neutral fat concentration, etc. Also, in addition to these, expressions, complexion, pupils, voiceprints, etc. are included. By using such various biometric information, it is preferable because the health state of the user can be comprehensively determined.

[0319] As a method for personal authentication using biometric information, typically, a pattern matching method can be mentioned. For example, from images such as fingerprints, palm prints, and vein patterns, characteristic amounts such as coordinates of a plurality of characteristic points and vectors between the coordinates of these points are calculated, and authentication can be performed by comparing with the characteristic amounts of a user acquired in advance. Among fingerprints, palm prints, and vein patterns, highly accurate authentication can be performed by using two or more images.

[0320] In addition, machine learning may be used for personal authentication using biometric information or for determining the health status. As the learning model used for machine learning, a pre-learned learning model may be used, or a learning model updated using the acquired user data may be used. As methods of machine learning, for example, there are supervised machine learning and unsupervised machine learning.

[0321] Hereinafter, a configuration example of a system according to an aspect of the present invention and an operation example of the system will be described with reference to the drawings.

[0322] FIG. 14 shows a block diagram of a system 90 including a display device according to an aspect of the present invention. The system 90 includes an arithmetic unit 91, a storage unit 92, an input unit 93, an output unit 94, a bus line 95, and the like. The system 90 can be applied to various electronic devices having a display unit, such as the above-described electronic device 80.

[0323] The arithmetic unit 91 is connected to the storage unit 92, the input unit 93, the output unit 94, and the like via the bus line 95, and has a function of comprehensively controlling these.

[0324] The storage unit 92 has a function of storing data, programs, and the like. The arithmetic unit 91 can control various components included in the input unit 93 and the output unit 94 by reading a program or data from the storage unit 92 and executing or processing it.

[0325] As the input unit 93, various sensor devices can be applied. Here, as components included in the input unit 93, an optical sensor 93a, a camera 93b, a microphone 93c, an electrocardiogram monitor 93d, etc. are shown. As the optical sensor 93a, a sensor using a light receiving element included in the display device can be applied. The electrocardiogram monitor 93d may have a configuration including, for example, a pair of electrodes for measuring an electrocardiogram and a measuring instrument for measuring the voltage between the electrodes or the value of the current flowing between the electrodes.

[0326] As the output unit 94, it has a function of providing various information to the user. Here, an example is shown in which components included in the output unit 94 include a display 94a, a speaker 94b, a vibration device 94c, etc.

[0327] Since the display device according to one aspect of the present invention has a light receiving element that functions as an optical sensor and a light emitting element that constitutes the display unit, one display device can also serve as the optical sensor 93a of the input unit 93 and the display 94a of the output unit 94 shown in FIG. 14. That is, the system 90 can be realized by a configuration including the display device, the arithmetic unit 91, and the storage unit 92.

[0328] For example, if the display device has a function of acquiring biometric information such as a user's fingerprint, palm print, or vein, the arithmetic unit 91 can perform fingerprint authentication, palm print authentication, or vein authentication based on the user's biometric information data stored in advance in the storage unit 92 and the acquired biometric information.

[0329] Hereinafter, an example of the operation method of the system according to one aspect of the present invention will be described. Here, the operation of performing biometric authentication will be described.

[0330] FIG. 15 is a flowchart related to the operation method of the system. The flowchart shown in FIG. 15 has steps S0 to S8.

[0331] In step S0, the operation is started.

[0332] In step S1, it is determined whether to execute the startup of the system. For example, when it is detected that the power of the electronic device is turned on, the display unit is touched, or the posture of the electronic device has changed, it is determined to execute the startup of the system. On the other hand, if these are not detected, the process proceeds to step S8 and the operation ends.

[0333] In step S2, it is determined whether authentication is required. If authentication has already been executed and the system is in the logged-in state, it is determined that authentication is not required, and the process proceeds to step S7. On the other hand, if it is in the logged-off state, it is determined that authentication is required, and the process proceeds to step S3.

[0334] In step S3, it is determined whether an authentication operation has been detected. For example, when it is detected that a user's finger or palm has touched a part of the display unit, it is determined that an authentication operation has been detected, and the process proceeds to step S4. On the other hand, if it is not detected for a certain period of time, the process proceeds to step S8 and the operation ends.

[0335] In step S4, authentication information is obtained. For example, the user's fingerprint, palmprint, vein, etc. are imaged, and biometric information is obtained from the captured image.

[0336] In step S5, it is determined whether the authentication has been performed correctly. For example, the fingerprint, palmprint, or vein information obtained in step S4 is compared with the pre-registered biometric information of the user to determine whether they match. The determination can be made by an authentication method such as a pattern matching method that does not use a machine learning model, or authentication using a machine learning model. If the authentication is performed correctly, the process proceeds to step S6. If the authentication is not performed correctly, the logged-off state is maintained and the process returns to step S4.

[0337] In step S6, the system is logged in.

[0338] In step S7, the logged-in state is maintained. Step S7 ends when the user performs an end operation or when it is detected that there is no input for a certain period of time, and then proceeds to step S8.

[0339] In step S8, the operation ends. Step S8 is at least in a logged-out state. It may also be in a power-off state, a standby state, or a sleep state. The return from step S8 may be performed by the operation detected in step S1 above.

[0340] Here, when applying to the electronic device 80 shown in FIG. 11A or the electronic device 80a shown in FIG. 12, the detection of the authentication operation in step S3 and the acquisition of the authentication information in step S4 can be executed by touching the fingertip on the display unit 81b or the display unit 81c as shown in FIGS. 11A and 12. Also, the biometric information acquired in step S4 can use an image such as a fingerprint obtained by imaging the reflected light from the fingertip by the light receiving element included in the display unit 81b or the display unit 81c.

[0341] That is, in the electronic device (for example, the electronic device 80 or the electronic device 80a) according to one aspect of the present invention, when the user's finger touches the display unit 81b or the display unit 81c, the arithmetic unit 91 can execute a fingerprint authentication operation based on the fingerprint image obtained by the light receiving element included in the display unit 81b or the display unit 81c imaging the reflected light from the finger. Thereby, the authentication operation can be executed without the user being conscious, and thus an electronic device having both convenience and high security can be realized.

[0342] The above is the description of the configuration example and operation example of the system according to one aspect of the present invention.

[0343] (Embodiment 3) In this embodiment, the configuration of the pixel applicable to the display device according to one aspect of the present invention will be described with reference to the drawings.

[0344] The display panel according to one aspect of the present invention includes a first pixel circuit having a light receiving element and a second pixel circuit having a light emitting element. The first pixel circuit and the second pixel circuit are each arranged in a matrix.

[0345] FIG. 16A shows an example of a first pixel circuit having a light receiving element, and FIG. 16B shows an example of a second pixel circuit having a light emitting element.

[0346] The pixel circuit PIX1 shown in FIG. 16A includes a light receiving element PD, transistors M1, M2, M3, M4, and a capacitive element C1. Here, an example using a photodiode as the light receiving element PD is shown.

[0347] 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 or drain of the transistor M1. The gate of the transistor M1 is electrically connected to the wiring TX, and the other of the source or drain is electrically connected to one electrode of the capacitive element C1, one of the source or 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 or drain is electrically connected to the wiring V2. One of the source or drain of the transistor M3 is electrically connected to the wiring V3, and the other of the source or drain is electrically connected to one of the source or drain of the transistor M4. The gate of the transistor M4 is electrically connected to the wiring SE, and the other of the source or drain is electrically connected to the wiring OUT1.

[0348] A constant potential is supplied to each of wiring V1, wiring V2, and wiring V3. When driving the light receiving element PD in reverse bias, a potential lower than the potential of wiring V1 is supplied to wiring V2. The transistor M2 is controlled by a signal supplied to 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 wiring V2. The transistor M1 is controlled by a signal supplied to wiring TX and has a function of controlling the timing at which the potential of the above node changes according to the current flowing through the light receiving element PD. The transistor M3 functions as an amplification transistor that outputs according to the potential of the above node. The transistor M4 is controlled by a signal supplied to wiring SE and functions as a selection transistor for reading out the output according to the potential of the above node to an external circuit connected to wiring OUT1.

[0349] The pixel circuit PIX2 shown in FIG. 16B includes a light emitting element EL, a transistor M5, a transistor M6, a transistor M7, and a capacitor element C2. Here, an example using a light emitting diode is shown as the light emitting element EL. In particular, it is preferable to use an organic EL element as the light emitting element EL.

[0350] The gate of the transistor M5 is electrically connected to the wiring VG, one of the source or the drain is electrically connected to the wiring VS, and the other of the source or the drain is electrically connected to one electrode of the capacitor element C2 and the gate of the transistor M6. One of the source or the 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 the 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 the drain is electrically connected to the wiring OUT2. The cathode of the light emitting element EL is electrically connected to the wiring V5.

[0351] A constant potential is supplied to wiring V4 and wiring V5, respectively. The anode side of the light-emitting element EL can be set to a high potential, and the cathode side can be set to a potential lower than the anode side. The transistor M5 is controlled by a signal supplied to wiring VG and functions as a selection transistor for controlling the selection state of the pixel circuit PIX2. Further, the transistor M6 functions as a drive transistor that controls the current flowing through the light-emitting element EL according to the potential supplied to the gate. When the transistor M5 is in the conductive state, the potential supplied to wiring VS is supplied to the gate of the transistor M6, and the emission luminance of the light-emitting element EL can be controlled according to that potential. The transistor M7 is controlled by a signal supplied to wiring MS and has a function of outputting the potential between the transistor M6 and the light-emitting element EL to the outside via wiring OUT2.

[0352] In the display panel of this embodiment, an image may be displayed by causing the light-emitting element to emit light in a pulse shape. By shortening the driving time of the light-emitting element, it is possible to reduce the power consumption of the display panel and suppress heat generation. In particular, an organic EL element is suitable because of its excellent frequency characteristics. The frequency can be, for example, 1 kHz or more and 100 MHz or less.

[0353] Here, it is preferable to apply transistors using a metal oxide (oxide semiconductor) to the semiconductor layer in which channels are formed in the transistors M1, M2, M3, and M4 included in the pixel circuit PIX1, and the transistors M5, M6, and M7 included in the pixel circuit PIX2, respectively.

[0354] Transistors using metal oxides with a wider bandgap and lower carrier density than silicon can achieve an extremely small off-current. Therefore, due to this small off-current, it is possible to hold the charge accumulated in the capacitive element connected in series with the transistor over a long period of time. Therefore, it is particularly preferable to use transistors with an oxide semiconductor applied to transistors M1, M2, and M5 that are connected in series to capacitive element C1 or capacitive element C2. In addition, by using transistors with an oxide semiconductor applied to other transistors as well, the manufacturing cost can be reduced.

[0355] Also, transistors M1 to M7 can use transistors with silicon applied to the semiconductor in which the channel is formed. In particular, by using highly crystalline silicon such as single-crystalline silicon or polycrystalline silicon, high field-effect mobility can be achieved, and faster operation is possible, which is preferable.

[0356] Also, among transistors M1 to M7, a configuration may be adopted in which transistors with an oxide semiconductor applied to one or more of them and transistors with silicon applied to the others are used.

[0357] In FIGS. 16A and 16B, the transistors are shown as n-channel type transistors, but p-channel type transistors can also be used.

[0358] The transistors included in pixel circuit PIX1 and the transistors included in pixel circuit PIX2 are preferably formed side by side on the same substrate. In particular, it is preferable to adopt a configuration in which the transistors included in pixel circuit PIX1 and the transistors included in pixel circuit PIX2 are mixed and periodically arranged within one region.

[0359] In addition, it is preferable to provide one or more layers having one or both of a transistor and a capacitor element at a position overlapping with the light receiving element PD or the light emitting element EL. Thereby, the effective occupied area of each pixel circuit can be reduced, and a high-definition light receiving portion or display portion can be realized.

[0360] This embodiment can be implemented in appropriate combination with other embodiments described herein at least in part.

[0361] (Embodiment 4) In this embodiment, an electronic device to which a display device according to an aspect of the present invention is applicable will be described with reference to the drawings.

[0362] The electronic device of this embodiment has a display device according to an aspect of the present invention. Since the display device has a function of detecting light, biometric authentication can be performed on the display portion, and touch or near-touch can be detected. The electronic device according to an aspect of the present invention is an electronic device that is difficult to be misused and has an extremely high security level. In addition, the functionality or convenience of the electronic device can be enhanced.

[0363] Examples of the electronic device include relatively large-screen electronic devices such as television devices, desktop or notebook personal computers, monitors for computers, digital signage, and large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, portable information terminals, and audio playback devices.

[0364] The electronic device of this embodiment may have a sensor (including a function of detecting, detecting, or measuring force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays).

[0365] The electronic device of the present embodiment can have various functions. For example, it can have functions such as displaying various types of information (still images, moving images, text images, etc.) on a display unit, a touch panel function, a function of displaying a calendar, date, or time, a function of executing various software (programs), a wireless communication function, a function of reading programs or data recorded on a recording medium, and the like.

[0366] The electronic device 6500 shown in FIG. 17A is a portable information terminal device that can be used as a smartphone.

[0367] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508, etc. The display unit 6502 has a touch panel function.

[0368] The display device of one aspect of the present invention can be applied to the display unit 6502.

[0369] FIG. 17B is a schematic cross-sectional view including an end portion on the microphone 6506 side of the housing 6501.

[0370] A protective member 6510 having translucency is provided on the display surface side of the housing 6501, and a display panel 6511, an optical member 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are arranged in a space surrounded by the housing 6501 and the protective member 6510.

[0371] The display panel 6511, the optical member 6512, and the touch sensor panel 6513 are fixed to the protective member 6510 by an adhesive layer (not shown).

[0372] In a region outside the display unit 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded-back portion. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on the printed circuit board 6517.

[0373] The display panel 6511 can be applied with the flexible display of one aspect of the present invention. Therefore, an extremely lightweight electronic device can be realized. Further, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted while suppressing the thickness of the electronic device. Further, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the pixel portion, a narrow bezel electronic device can be realized.

[0374] FIG. 18A shows an example of a television device. In the television device 7100, a display unit 7000 is incorporated in a housing 7101. Here, a configuration in which the housing 7101 is supported by a stand 7103 is shown.

[0375] The display device of one aspect of the present invention can be applied to the display unit 7000.

[0376] The operation of the television device 7100 shown in FIG. 18A can be performed by an operation switch provided in the housing 7101 or a separate remote control operation unit 7111 or the like. Alternatively, the display unit 7000 may be provided with a touch sensor, and the television device 7100 may be operated by touching the display unit 7000 with a finger or the like. The remote control operation unit 7111 may have a display unit that displays information output from the remote control operation unit 7111. Channel and volume operations can be performed by operation keys or a touch panel provided in the remote control operation unit 7111, and the video displayed on the display unit 7000 can be operated.

[0377] Note that the television device 7100 has a configuration including a receiver and a modem or the like. General television broadcasts can be received by the receiver. Further, by connecting to a communication network by wire or wirelessly via the modem, one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers) information communication is also possible.

[0378] FIG. 18B shows an example of a notebook personal computer. The notebook personal computer 7200 has a housing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, etc. A display unit 7000 is incorporated in the housing 7211.

[0379] The display device according to one aspect of the present invention can be applied to the display unit 7000.

[0380] FIGS. 18C and 18D show an example of digital signage.

[0381] The digital signage 7300 shown in FIG. 18C has a housing 7301, a display unit 7000, a speaker 7303, etc. Further, it can have an LED lamp, operation keys (including a power switch or an operation switch), connection terminals, various sensors, a microphone, etc.

[0382] FIG. 18D shows a digital signage 7400 attached to a cylindrical pillar 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of the pillar 7401.

[0383] In FIGS. 18C and 18D, the display device according to one aspect of the present invention can be applied to the display unit 7000.

[0384] The larger the display unit 7000 is, the more information can be provided at once. Also, the larger the display unit 7000 is, the easier it is for people's eyes to notice, and for example, the advertising effect can be enhanced.

[0385] By applying a touch panel to the display unit 7000, not only can an image or video be displayed on the display unit 7000, but also the user can operate it intuitively, which is preferable. Also, when used for applications such as providing route information or traffic information, the usability can be enhanced by intuitive operation.

[0386] Also, as shown in FIGS. 18C and 18D, it is preferable that the digital signage 7300 or the digital signage 7400 can be linked with an information terminal device 7311 such as a smartphone or an information terminal device 7411 held by a user through wireless communication. For example, the information of the advertisement displayed on the display unit 7000 can be displayed on the screen of the information terminal device 7311 or the information terminal device 7411. Further, by operating the information terminal device 7311 or the information terminal device 7411, the display on the display unit 7000 can be switched.

[0387] Also, a game can be executed on the digital signage 7300 or the digital signage 7400 using the screen of the information terminal device 7311 or the information terminal device 7411 as an operation means (controller). Thereby, an unspecified number of users can participate in and enjoy the game simultaneously.

[0388] The electronic device shown in FIGS. 19A to 19F includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), connection terminals 9006, a sensor 9007 (including a function of detecting, detecting, or measuring force, displacement, position, speed, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays), a microphone 9008, and the like.

[0389] The electronic devices shown in FIGS. 19A to 19F have various functions. For example, they can have functions such as displaying various information (still images, moving images, text images, etc.) on a display unit, a touch panel function, a function of displaying a calendar, date, or time, a function of controlling processing by various software (programs), a wireless communication function, a function of reading and processing programs or data recorded on a recording medium, etc. Note that the functions of the electronic device are not limited to these, and it can have various functions. The electronic device may have a plurality of display units. Also, the electronic device may be provided with a camera or the like and have functions such as photographing a still image or a moving image and storing it in a recording medium (external or built into the camera), and displaying the photographed image on the display unit, etc.

[0390] The details of the electronic devices shown in FIGS. 19A to 19F will be described below.

[0391] FIG. 19A is a perspective view showing a portable information terminal 9101. The portable information terminal 9101 can be used, for example, as a smartphone. Note that the portable information terminal 9101 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, etc. Also, the portable information terminal 9101 can display character or image information, etc. on its plurality of surfaces. FIG. 19A shows an example in which three icons 9050 are displayed. Also, information 9051 indicated by a dashed rectangle can be displayed on another surface of the display unit 9001. Examples of the information 9051 include notifications of incoming calls such as e-mails, SNS, and phone calls, titles of e-mails or SNS, sender names, dates, times, remaining battery levels, antenna reception strengths, etc. Or, icons 9050 or the like may be displayed at the position where the information 9051 is displayed.

[0392] FIG. 19B is a perspective view showing a portable information terminal 9102. The portable information terminal 9102 has a function of displaying information on three or more sides of a display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different surfaces respectively. For example, the user can also check the information 9053 displayed at a position where it can be observed from above the portable information terminal 9102 while the portable information terminal 9102 is stored in the breast pocket of the clothing. The user can check the display without taking out the portable information terminal 9102 from the pocket, and can determine, for example, whether to answer a call.

[0393] FIG. 19C is a perspective view showing a wristwatch-type portable information terminal 9200. Further, the display surface of the display unit 9001 is provided to be curved, and display can be performed along the curved display surface. Further, the portable information terminal 9200 can also perform hands-free calling by mutually communicating with, for example, a wirelessly communicable headset. Further, the portable information terminal 9200 can also perform data transmission or charging mutually with other information terminals through a connection terminal 9006. Note that the charging operation may be performed by wireless power supply.

[0394] FIGS. 19D, 19E, and 19F are perspective views showing a foldable portable information terminal 9201. Further, FIG. 19D shows a state in which the portable information terminal 9201 is unfolded, FIG. 19F shows a folded state, and FIG. 19E is a perspective view of a state in the process of changing from one of FIGS. 19D and 19F to the other. The portable information terminal 9201 is excellent in portability in the folded state, and excellent in display listability due to a seamless wide display area in the unfolded state. The display unit 9001 included in the portable information terminal 9201 is supported by three housings 9000 connected by a hinge 9055. For example, the display unit 9001 can be bent with a curvature radius of 0.1 mm or more and 150 mm or less.

[0395] This embodiment can be implemented in appropriate combination with at least a part of other embodiments described in this specification.

Example

[0396] In this embodiment, a display device according to one aspect of the present invention was fabricated, and the results of imaging a vein will be described.

[0397] [Light-receiving element] Fig. 20 shows the characteristics of the fabricated light-receiving element. In Fig. 20, the vertical axis represents the external quantum efficiency (EQE [%]), and the horizontal axis represents the wavelength (Wavelength [nm]). As shown in Fig. 20, it was confirmed that the fabricated light-receiving element exhibited high sensitivity from ultraviolet light to infrared light (400 nm - 900 nm).

[0398] [Light-emitting element] Fig. 21A shows a schematic diagram of a light-emitting element that emits infrared light used in the display device. Here, two types of light-emitting elements were fabricated. One is a light-emitting element (denoted as Ref.) having one light-emitting unit between the anode and the cathode as shown on the left side of Fig. 21A. The other is a light-emitting element (denoted as Sample 1) having two light-emitting units stacked between the anode and the cathode as shown on the right side of Fig. 21A. Each of the one light-emitting unit of Ref. and the two light-emitting units of Sample 1 has the same configuration and has a light-emitting layer containing a light-emitting substance that emits infrared light.

[0399] Fig. 21B shows the emission spectra of the two types of fabricated light-emitting elements. In Fig. 21B, the vertical axis represents the normalized emission intensity (Intensity [a.u.]), and the horizontal axis represents the wavelength (Wavelength [nm]). As shown in Fig. 21B, it was found that both types of light-emitting elements emit light in the range of wavelengths of 700 nm or more and 950 nm or less, and have a peak near a wavelength of 800 nm. Also, almost no difference in the spectral shape was observed between the two types of light-emitting elements.

[0400] Fig. 22A shows the measurement results of the external quantum efficiency - current density characteristics of the two types of light-emitting elements, and Fig. 22B shows the measurement results of the current density - voltage characteristics, respectively.

[0401] In FIG. 22A, the vertical axis represents the external quantum efficiency, and the horizontal axis represents the current density (Current Density [mA / cm 2 ). Further, in FIG. 22B, the vertical axis represents the current density, and the horizontal axis represents the voltage (Voltage [V]). As shown in FIGS. 22A and 22B, although the driving voltage of Sample 1 having a stacked structure is higher than that of Ref., it can be confirmed that the external quantum efficiency increases and shows a value approximately twice as high.

[0402] [Imaging Results] A display panel was fabricated using the above light-emitting element and a light-receiving element. The configuration of the display panel can be the same as that of the display device 100B (FIG. 4B) exemplified in Embodiment 1. The above light-receiving element was applied to the light-receiving element 110 in the display device 100B, and either Ref. or Sample 1 was applied to the light-emitting element 160. Further, the light-emitting element that emits infrared light is a bottom emission type light-emitting element, and among the pair of electrodes, the electrode on the formation surface side (display surface side) (electrode 161 in FIG. 4B) is the cathode, and the other (electrode 163t) is the anode.

[0403] First, as shown in FIG. 23A, imaging was performed with the light-emitting element that emits infrared light in the display panel (Display Panel) emitting light.

[0404] FIG. 23B shows the imaging results when the Ref. element is applied to the light-emitting element that emits infrared light. The dashed line in FIG. 23B schematically shows the outline of the finger. As shown in FIG. 23B, although the contrast is low, it can be seen that the shape of the blood vessels in the finger can be recognized.

[0405] Subsequently, FIG. 23C shows the imaging results when the Sample 1 element is applied to the light-emitting element that emits infrared light. It can be seen that the shape of the blood vessels can be clearly confirmed when the Sample 1 element having a stacked structure is used.

[0406] Also, as shown in FIG. 23D, imaging was performed with infrared light of a wavelength of 850 nm emitted by a light-emitting diode (LED) from above the finger. At this time, the light-emitting element that emits infrared light on the display panel side was turned off.

[0407] FIG. 23E shows the imaging result. Thus, it was confirmed that the shape of the blood vessels can be clearly imaged not only when reflected light is used but also when transmitted light is used.

Explanation of Reference Numerals

[0408]

Claims

1. It has a first light-emitting element, a second light-emitting element, a light-receiving element, and a light-shielding layer, The first light-emitting element and the light-receiving element are arranged side by side on the same plane, The light-shielding layer is provided above the first light-emitting element and the light-receiving element, The second light-emitting element is provided above the light-shielding layer, The first light-emitting element has a function of emitting visible light upward, The second light-emitting element has a function of emitting invisible light upward, The light-receiving element is a photoelectric conversion element having sensitivity to the visible light and the invisible light, In a plan view, The light-shielding layer has a portion located between the first light-emitting element and the light-receiving element, The second light-emitting element overlaps the light-shielding layer and is located inside the contour of the light-shielding layer, A display device.

2. In Claim 1, The invisible light is light having intensity in a wavelength range of 750 nm or more and 900 nm or less, A display device.

3. It has a first substrate, a second substrate, a first light-emitting element, a second light-emitting element, a light-receiving element, a light-shielding layer, a first resin layer, and a second resin layer, The first light-emitting element and the light-receiving element are arranged side by side on the first substrate, The first resin layer is provided on the first light-emitting element and the light-receiving element, The light-shielding layer is provided on the first resin layer, The second resin layer is provided on the light-shielding layer, The second light-emitting element is provided on the second resin layer, The second substrate is provided on the second light-emitting element, The first light-emitting element has a function of emitting visible light upward, The second light-emitting element has a function of emitting invisible light upward, The light-receiving element is a photoelectric conversion element having sensitivity to the visible light and the invisible light, In a plan view, The light-shielding layer has a portion located between the first light-emitting element and the light-receiving element, The second light-emitting element overlaps the light-shielding layer and is located inside the contour of the light-shielding layer, A display device.

4. In Claim 3, The invisible light is light having intensity in a wavelength range of 750 nm or more and 900 nm or less, A display device.

5. In Claim 3 or Claim 4, It has a first protective layer, The first protective layer contains an inorganic insulating material and is located between the first light-emitting element and the light-receiving element and the first resin layer, The first resin layer is provided along the upper surface of the first protective layer, A display device.

6. In any one of claims 3 to 5, having a second protective layer, the second protective layer includes an inorganic insulating material and is located between the second resin layer and the second light-emitting element, the light-shielding layer is provided along the lower surface of the second resin layer, A display device.

7. In any one of claims 3 to 6, the first resin layer exhibits a first refractive index with respect to light having a wavelength of 850 nm, the second resin layer exhibits a second refractive index with respect to light having a wavelength of 850 nm, the difference between the first refractive index and the second refractive index is 10% or less of the first refractive index, A display device.

8. In any one of claims 3 to 7, the first light-emitting element has a first pixel electrode, a first light-emitting layer, and a first electrode, the light-receiving element has a second pixel electrode, an active layer, and the first electrode, the first light-emitting layer and the active layer each contain different organic compounds, the first electrode has a portion overlapping the first pixel electrode through the first light-emitting layer and a portion overlapping the second pixel electrode through the active layer, the first pixel electrode and the second pixel electrode contain the same conductive material, A display device.

9. In any one of claims 3 to 8, the second light-emitting element has a third pixel electrode, a second light-emitting layer, and a second electrode from the second substrate side, the third pixel electrode has translucency with respect to the invisible light, the second electrode has reflectivity with respect to the invisible light, in plan view, the second electrode is located inside the contour of the light-shielding layer, A display device.

10. In any one of claims 3 to 8, the second light-emitting element has a third pixel electrode, a second light-emitting layer, and a second electrode from the second substrate side, the third pixel electrode has translucency with respect to the invisible light, the second electrode has translucency with respect to the visible light and the invisible light, in plan view, the second electrode has a portion overlapping the light-shielding layer, a portion overlapping the first light-emitting element, and a portion overlapping the light-receiving element, A display device.

11. In any one of claims 3 to 8, having a reflective layer, the second light-emitting element has a third pixel electrode, a second light-emitting layer, and a second electrode from the second substrate side, the third pixel electrode and the second electrode have translucency with respect to the invisible light, The reflective layer has reflectivity with respect to the invisible light and is located between the light shielding layer and the second electrode. In plan view, the reflective layer is located inside the contour of the light shielding layer. Display device.

12. A display module having the display device according to any one of Claims 1 to 11 and a connector or an integrated circuit. Display module.

13. A display module according to Claim 12, having at least one of an antenna, a battery, a housing, a camera, a speaker, a microphone, a touch sensor, and an operation button. Electronic device.

14. In Claim 13, a first imaging function of receiving, by the light receiving element, first reflected light when the visible light is emitted from the first light emitting element; a second imaging function of receiving, by the light receiving element, second reflected light when the invisible light is emitted from the second light emitting element. Electronic device.

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