Display device

Abstract

To provide a display device having a function of emitting visible light and infrared light and imaging function, and to achieve higher resolution without changing image pickup device density while maintaining high-definition image display of the display device.SOLUTION: The display device has layout in which on the same substrate, light receiving areas of image pickup devices are disposed among light emission areas of a plurality of light-emitting elements. Imaging function included in the display device includes, as imaging means for achieving higher high resolution, achieving higher resolution without changing image pickup device density by performing imaging in a time-division manner.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] 1. Field of the Invention An embodiment of the present invention relates to a display device or an imaging device.

[0002] Note that one embodiment of the present invention is not limited to the above technical field. One embodiment of the present invention disclosed in this specification relates to an object, a method, or a manufacturing method. One embodiment of the present invention relates to a process, a machine, a manufacture, or a composition of matter. Therefore, examples of the technical field of one embodiment of the present invention disclosed in this specification include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, an electronic device, a lighting device, an input device, an input / output device, a driving method thereof, or a manufacturing method thereof.

[0003] In this specification and the like, a semiconductor device refers to any device that can function by utilizing semiconductor characteristics. Semiconductor elements such as transistors, semiconductor circuits, arithmetic devices, and memory devices are all embodiments of semiconductor devices. Imaging devices, display devices, liquid crystal display devices, light-emitting devices, input devices, input / output devices, electro-optical devices, power generation devices (including thin-film solar cells, organic thin-film solar cells, and the like), and electronic devices may include semiconductor devices. [Background technology]

[0004] An imaging panel having a plurality of imaging pixels on an insulating surface of a substrate is known (Patent Document 1). The imaging pixels include a plurality of windows arranged in a matrix pattern that transmit visible light, a lattice-shaped photoelectric conversion element extending between the plurality of windows and supplying a signal, and a detection circuit to which the signal is supplied. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2015-005280 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of one embodiment of the present invention is to provide a display device that has a function of emitting visible light and infrared light.An object of one embodiment of the present invention is to provide a highly convenient display device.An object of one embodiment of the present invention is to provide a multifunctional display device.An object of one embodiment of the present invention is to provide a novel display device.

[0007] An object of one embodiment of the present invention is to provide a display device that has a function of emitting visible light and infrared light and an imaging function.

[0008] The resolution of the imaging function is primarily determined by the density of the imaging elements used. Increasing the number of imaging elements per area can lead to a decrease in the resolution of the display device and a complication of the manufacturing process.

[0009] To make a full-color display device, at least three types of light-emitting elements, R, G, and B, are arranged. The display surface of the display device is limited, so the light-emitting area of ​​the light-emitting element and the light-receiving area of ​​the image sensor are arranged within each pixel. Therefore, there is a limit to how many image sensors can be added due to restrictions on the area occupied and process processing accuracy.

[0010] In view of the above, it is an object of the present invention to achieve high resolution without changing the density of an imaging element while maintaining high definition of an image displayed on a display device.

[0011] Another object of the present invention is to provide a new device having a display device that has a means for capturing an image of a fingerprint or the like touching the display surface with high precision and accuracy.

[0012] Another object is to provide a structure that suppresses an increase in manufacturing costs of a display device even if a light-receiving region is provided on the display surface. [Means for solving the problem]

[0013] The display device has a layout in which the light receiving region of the image sensor is located between the light emitting regions of a plurality of light emitting elements on the same substrate. In the image capturing function of the display device, as an image capturing means for further increasing the resolution, the image capturing is performed in a time-division manner, thereby increasing the resolution without changing the density of the image capturing elements.

[0014] Time-division imaging refers to imaging multiple times in succession at a predetermined exposure time. By imaging continuously in a time-division manner, it is possible to synthesize multiple images that are intermittently exposed and read out. In this specification, a first exposure (exposure with a first time-division exposure time) from a light-emitting region on one side arranged adjacent to the image sensor and a second exposure (exposure with a second time-division exposure time) from a light-emitting region on the other side are sequentially and continuously performed.

[0015] The configuration of the invention disclosed in this specification is a display device comprising a light-transmitting substrate, a substrate having an insulating surface fixed facing the substrate, a plurality of light-receiving regions and a plurality of light-emitting regions on the substrate having the insulating surface, a first light-shielding layer having an opening in the light-transmitting substrate, and a second light-shielding layer spaced apart from the first light-shielding layer, wherein the opening of the first light-shielding layer is positioned to overlap with one of the plurality of light-receiving regions, and the second light-shielding layer is positioned to overlap with a portion of one of the light-receiving regions.

[0016] In the above configuration, the plurality of light-emitting regions are any one of a green light-emitting region, a blue light-emitting region, a red light-emitting region, and an infrared light-emitting region.

[0017] Another invention provides a display device having a light-transmitting substrate, a substrate having an insulating surface fixed opposite the substrate, two light-emitting regions on the substrate having the insulating surface, one light-receiving region located between the two light-emitting regions, a first light-shielding layer having an opening on the light-transmitting substrate, and a second light-shielding layer spaced apart from the first light-shielding layer, wherein the opening of the first light-shielding layer is positioned to overlap with the light-emitting region or the light-receiving region, and the second light-shielding layer is positioned to overlap with a portion of one of the light-receiving regions.

[0018] In the above configuration, the light emitting region may be a monochromatic light emitting region, for example a green light emitting region.

[0019] In addition, in each of the above configurations, the number of light-emitting regions in the display device can be greater than the number of light-receiving regions, and the display device can be made to have a high resolution without changing the density of the imaging device while maintaining high definition.

[0020] In each of the above configurations, the width of the second light-shielding layer is not less than 5 μm and not more than 10 μm. This range of values ​​makes it possible to obtain a sufficient S / N ratio even when imaging is performed in a time-division manner.

[0021] In each of the above structures, the first light-shielding layer and the second light-shielding layer are made of the same material. If the first light-shielding layer and the second light-shielding layer can be formed of the same material in the same process, the light-receiving element can be built into the display device without significantly increasing the number of manufacturing steps.

[0022] In each of the above structures, a light-transmitting organic resin is provided between the light-transmitting substrate and the substrate having an insulating surface.

[0023] In each of the above configurations, the light-emitting region includes a pixel electrode and an organic compound layer overlapping the pixel electrode.

[0024] In each of the above structures, the light receiving region contains the same material as the organic compound layer overlapping the pixel electrode. If the organic compound layer overlapping the pixel electrode can be formed of the same material and in the same process, the light receiving element can be built in the display device without significantly increasing the number of manufacturing steps. Effect of the Invention

[0025] According to one embodiment of the present invention, a multi-function display device can be provided. According to one embodiment of the present invention, a novel display device can be provided. According to one embodiment of the present invention, a display device having a function of emitting visible light and infrared light and an imaging function can be provided.

[0026] According to one embodiment of the present invention, the resolution can be improved without increasing the density of the imaging element. [Brief description of the drawings]

[0027] [Figure 1] 1A and 1B are schematic cross-sectional views showing one embodiment of the present invention. [Diagram 2] FIG. 2A shows an example in which two lights are emitted simultaneously, and FIG. 2B is a schematic cross-sectional view showing one embodiment of the present invention. [Diagram 3] FIG. 3A is a structure showing the setting conditions for calculation, and FIGS. 3B, 3C, and 3D are comparative examples showing arrangement models. [Figure 4] 4A, 4B, and 4C are layout models showing this embodiment. [Diagram 5] FIG. 5 is a diagram showing the calculation results of the layout model 1. [Figure 6] FIG. 6 is a diagram showing the calculation results of the layout model 6. [Figure 7] FIG. 7 is a graph showing a summary of the calculation results for layout models 1, 2, 3, 4, 5, and 6. [Figure 8] FIG. 8 is a graph showing the results of comparing the number of received light rays for layout models 1, 2, 3, 4, 5, and 6. [Figure 9] 9A, 9B, 9C, and 9D are cross-sectional views showing an example of a display device, and FIGS. 9E, 9F, 9G, 9H, and 9I are top views showing an example of a pixel. [Figure 10] FIG. 10 is a cross-sectional view showing an example of a display device. [Figure 11] 11A and 11B are circuit diagrams showing an example of a pixel circuit. [Figure 12] FIG. 12A is a perspective view showing an example of an electronic device, and FIG. 12B is a cross-sectional view showing the example of the electronic device. [Figure 13] 13A and 13B are diagrams showing an example of an electronic device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be easily understood by those skilled in the art that the form and details of the present invention can be modified in various ways. Furthermore, the present invention is not to be interpreted as being limited to the description of the embodiments shown below.

[0029] (Embodiment 1) 1A and 1B are schematic cross-sectional views of a display device according to one embodiment of the present invention.

[0030] 1A and 1B, a first substrate 51, a second substrate 59, a resin layer 58, a first light-emitting element OLED1, a second light-emitting element OLED2, an image sensor OPD, and an element layer 55 are shown, respectively.

[0031] An element layer is provided on a first substrate 51. The element layer 55 includes transistors, capacitors, and the like.

[0032] Moreover, materials having transparency to visible light or infrared light are used for both the resin layer 58 and the second substrate 59. A glass substrate may be used as the second substrate 59, or a film-like plastic substrate such as polyimide (PI), aramid, polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), polycarbonate (PC), nylon, polyether ether ketone (PEEK), polysulfone (PSF), polyetherimide (PEI), polyarylate (PAR), polybutylene terephthalate (PBT), silicone resin, or the like may be used.

[0033] 1A and 1B show how a fingerprint of a finger is captured in a time-division manner. When a first exposure and a second exposure are performed sequentially, FIG. 1A is a schematic diagram showing the state during the first exposure, and FIG. 1B is a schematic diagram showing the state during the second exposure.

[0034] In Fig. 1A, light emitted from the first light-emitting element OLED1 is reflected by a finger and is detected by the image sensor OPD. The main area to be imaged is the area indicated by the double-headed arrow overlapping with a subject 52 such as a finger in Fig. 1A.

[0035] 1B, the light emitted from the second light-emitting element OLED2 is reflected by a finger and is detected by the image sensor OPD. The main area to be imaged is the area indicated by the double-headed arrow that overlaps with a subject 52 such as a finger.

[0036] When the first light-emitting element OLED1 and the second light-emitting element OLED2 are caused to emit light almost simultaneously, as shown in FIG. 2A, the image sensor OPD detects reflected light from a wide range directly above the image sensor OPD (the range indicated by the double arrow at a position overlapping with a subject 52 such as a finger).

[0037] On the other hand, if the main component of the reflected light being detected is the specular reflection component, as shown in FIG. 2B, the positions at which the light emitted from the first light-emitting element OLED1 and the light emitted from the second light-emitting element OLED2 are detected are shifted. Light reflection can be broadly divided into two types: specular reflection and diffuse reflection. The specular reflection component is a component in which the incident angle and reflection angle are equal and the reflected light is a parallel ray. In the case of FIG. 2B, if the emission timing of the first light-emitting element OLED1 and the emission timing of the second light-emitting element OLED2 are shifted (time-divided) and the reflected light is detected, it is possible to detect reflection information from multiple locations with one image sensor OPD. Therefore, it can be said that it is possible to achieve high-definition captured images without increasing the number of image sensors OPD.

[0038] Below, optical simulation (ray tracing) is performed to examine the optical system.

[0039] FIG. 3A shows a cross-sectional view of the optical system used in the optical simulation.

[0040] An optical simulation is performed assuming a pixel density of 212 ppi (pixel size 120 μm square) for the display panel. The imaging element OPD is placed at the center (X = 0), and on both sides thereof, the first light-emitting element OLED1 and the second light-emitting element OLED2 are placed 60 μm apart from each other. The configuration in the vertical axis direction (laminated configuration) is also set with the film thickness and optical constants assumed for the display panel (detailed conditions are also described in Fig. 3A). The thickness of the resin layer 58 is 10 μm, and its refractive index n is 1.6. Also, the thickness of the substrate (the second substrate 59) is 200 μm, and the refractive index n is 1.5. The width of the opening of the light-shielding layer 45 is 20 μm. The width of the imaging element OPD, that is, the width of the light-receiving region here, is also 20 μm. The width of the light-emitting region of the first light-emitting element OLED1 is also 20 μm. Also, the scatterer has a width of 60 μm (equivalent to 424 ppi).

[0041] Further, Fig. 3B shows a light-shielding layer arrangement model 1 as a comparative example. Note that the light-shielding layer arrangement model 1 corresponds to Fig. 3A.

[0042] Further, Fig. 3C shows another comparative example of a light-shielding layer arrangement model 2. In the arrangement model 2, the width of the opening of the light-shielding layer is 30 μm.

[0043] Further, Fig. 3D shows another comparative example of a light-shielding layer arrangement model 3. In the arrangement model 3, the width of the opening of the light-shielding layer is 10 μm.

[0044] Also, in the above simulation, a completely scattered scatterer (subject) is placed on the second substrate 59, and the change in the amount of light detected by the imaging element OPD is simulated while shifting its position in the X-axis direction. Thereby, it can be confirmed at which position the scatterer is when the reflected light is received most strongly, that is, from which position the reflected light is received most strongly. It is confirmed how the lighting states of the first light-emitting element OLED1 and the second light-emitting element OLED2 affect this characteristic.

[0045] The results of the comparative example (arrangement model 1) are shown in Fig. 5.

[0046] As shown in Figure 2B, when both light-emitting elements are turned on, it can be confirmed that the number of received light rays is the largest when the scatterer is placed centered on the position of X = 0 (when it is directly above the OPD). On the other hand, when only the first light-emitting element OLED1 or only the second light-emitting element OLED2 is turned on, it can be confirmed that the center position of the scatterer where the number of received light rays is the largest is shifted from X = 0 by about 40 μm toward the first light-emitting element OLED1 or the second light-emitting element OLED2, respectively, and in some cases by about 50 μm.

[0047] Therefore, by alternately lighting and capturing images of the first light-emitting element OLED1 and the second light-emitting element OLED2, it becomes possible to detect reflected components mainly from different positions, and it becomes possible to obtain high-definition captured images based on the principle shown in FIG. 2B. However, even when only the first light-emitting element OLED1 is lit near 60 μm in FIG. 5, reflected components are detected on the OLED2 side (area where the center position of the scatterer is greater than 0). Even when only the second light-emitting element OLED2 is lit near -30 μm in FIG. 5, reflected components are detected on the OLED1 side (area where the center position of the scatterer is less than 0). Thus, the S / N ratio in the comparative example (arrangement model 1) is not sufficient.

[0048] The S / N ratio represents the ratio of the white level to the black level of the total signal received by the image sensor OPD. The white level is when a certain amount of light is irradiated, and the black level is when all light is blocked, and is measured as an average value.

[0049] Moreover, the two comparative examples (arrangement models 2 and 3) both had low S / N ratios.

[0050] Therefore, in order to improve the S / N ratio, an island-shaped light-shielding layer (second light-shielding layer 44) is provided at a position overlapping a part of the light-receiving region of one image sensor OPD. Note that the island-shaped light-shielding layer (second light-shielding layer 44) is disposed separately from and not in contact with other light-shielding layers (first light-shielding layers 45). The first light-shielding layers 45 may be connected to each other in a lattice pattern on a plane.

[0051] 4A shows an arrangement model 4 in which the width of the second light-shielding layer 44 is 5 μm. In actual processing, the minimum width required for processing the light-shielding layer is about 5 μm, so it is difficult to form a light-shielding layer (second light-shielding layer 44) with a width less than 5 μm. In addition, the width of the opening of the first light-shielding layer 45 is 20 μm.

[0052] 4B shows Arrangement Model 5 in which the width of second light-shielding layer 44 is 10 μm. The width of the opening of first light-shielding layer 45 is 20 μm, which is the same as Arrangement Model 1.

[0053] 4C shows an arrangement model 6 in which the width of the second light-shielding layer 44 is 10 μm. The width of the opening of the first light-shielding layer 45 is 30 μm.

[0054] The calculation results using model 6 in Fig. 4C are shown in Fig. 6. The S / N ratio has improved compared to Fig. 5, and even when only OLED1 is lit, almost no reflected components are detected on the OLED2 side (the area where the scatterer center position is greater than 0) around 60 μm in Fig. 6.

[0055] Moreover, a summary of the calculation results for layout models 1, 2, 3, 4, 5, and 6 is shown in Figure 7.

[0056] In Figure 7, the condition when OLED1 is turned on is black (= low number of received light rays) because there is no scatterer placed directly above it, as shown in Figure 3A. Also, the condition when OLED2 is turned on is white (= high number of received light rays) because there is a scatterer placed directly above it. Therefore, the number of light rays when OLED2 is turned on / the number of light rays when OLED1 is turned on corresponds to the S / N ratio near the boundary of the scatterer.

[0057] In the case of light-shielding layer arrangement models 1, 2, and 3, in which only the size of the opening in the light-shielding layer is different, the number of received light rays itself increases or decreases according to the opening, but it can be confirmed that there is no change in the S / N ratio itself. On the other hand, in arrangement models 4, 5, and 6, in which a second light-shielding layer 44 is arranged on the OPD, it can be confirmed that the S / N ratio improves.

[0058] FIG. 8 shows the results of comparing the number of received light rays when OLED2 is turned on and when both OLED1 and OLED2 are turned on simultaneously.

[0059] From the results in Figure 8, it can be seen that for layout models 4, 5, and 6, in which the second light-shielding layer 44 is located directly above the OPD, there tends to be no significant difference between the number of light rays when OLED2 is turned on and the number of received light rays when both OLED1 and OLED2 are turned on. These results show that regardless of which of the two OLEDs is turned on, the area that delivers reflected light to the OPD, i.e., causing a decrease in the S / N ratio, is located directly above the OPD, i.e., in the vicinity of directly above the exposure area. Blocking this light from the vicinity directly above the OPD with the second light-shielding layer 44 is important in time-sharing to separate the two imaging ranges, and in Figure 7, the S / N ratio is improved in layout models 4, 5, and 6.

[0060] (Embodiment 2) In this embodiment mode, the top surface and cross-sectional structures of the OPD shown in Embodiment Mode 1 will be described below.

[0061] The display device exemplified below is a device having a function of displaying an image and a function of capturing an image of a subject overlapping the screen.

[0062] The display device of this embodiment has a display portion including a light receiving element and a light emitting element. Specifically, the light emitting elements are arranged in a matrix in the display portion, and an image can be displayed on the display portion.

[0063] The display unit also has a function as a light receiving unit, with light receiving elements arranged in a matrix. The light receiving unit can be used as an image sensor or a touch sensor. That is, by detecting light with the light receiving unit, it is possible to obtain image data, that is, capture an image, or detect the proximity or contact of an object (such as a finger or a pen).

[0064] In the display device of this embodiment, when an object reflects the light emitted by a light-emitting element in the display unit, the light-receiving element can detect the reflected light, making it possible to capture images and detect touches (including near-touches) even in dark places.

[0065] The display device of this embodiment has a function of displaying an image using a light-emitting element, that is, the light-emitting element functions as a display element.

[0066] As the light-emitting element, it is preferable to use an EL element such as an OLED (Organic Light Emitting Diode) or a QLED (Quantum-dot Light Emitting Diode). Examples of the light-emitting substance that the EL element has include a substance that emits fluorescence (fluorescent material), a substance that emits phosphorescence (phosphorescent material), an inorganic compound (such as a quantum dot material), and a substance that exhibits thermally activated delayed fluorescence (thermally activated delayed fluorescence: TADF material). Also, an LED such as a micro LED (Light Emitting Diode) can be used as the light-emitting element.

[0067] The display device of this embodiment mode has a function of detecting light using a light receiving element.

[0068] In the case where the light receiving element is used as an image sensor, the display device of this embodiment mode can capture an image by using the light receiving element.

[0069] For example, data such as fingerprints, palm prints, or irises can be acquired using an image sensor. That is, a biometric authentication sensor can be built into the display device of the present embodiment. By building a biometric authentication sensor into the display device, the number of components in the electronic device can be reduced, and the electronic device can be made smaller and lighter, compared to a case where a biometric authentication sensor is provided separately from the display device.

[0070] In addition, data such as the user's facial expression, eye movement, or change in pupil diameter can be obtained using an image sensor. By analyzing the data, the user's mental and physical information can be obtained. By changing the display and / or audio output content based on the information, it is possible to ensure that the user can use the device safely, for example, in a VR (Virtual Reality) device, an AR (Augmented Reality) device, or an MR (Mixed Reality) device.

[0071] When the light-receiving element is used as a touch sensor, the display device of this embodiment can detect the proximity or contact of an object by using the light-receiving element.

[0072] The light receiving element can be, for example, a pn-type or pin-type photodiode. The light receiving element functions as a photoelectric conversion element that detects light incident on the light receiving element and generates electric charge. The amount of electric charge generated is determined based on the amount of incident light.

[0073] In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light receiving element. Organic photodiodes can be easily made thin, lightweight, and large in area, and have a high degree of freedom in shape and design, and therefore can be applied to various display devices.

[0074] In one embodiment of the present invention, an organic EL element is used as a light-emitting element, and an organic photodiode is used as a light-receiving element. Many layers of an organic photodiode can be configured in common with an organic EL element. Therefore, a light-receiving element can be built into a display device without significantly increasing the number of manufacturing steps. For example, an active layer of the light-receiving element and a light-emitting layer of the light-emitting element can be separately manufactured, and the other layers can be configured in the same manner for the light-emitting element and the light-receiving element.

[0075] 9A, 9B, 9C, and 9D are schematic cross-sectional views of a portion of a display device according to one embodiment of the present invention.

[0076] A display device 50A shown in FIG. 9A has, between a first substrate 51 and a second substrate 59, a layer 53 having light receiving elements and a layer 57 having light emitting elements.

[0077] The display device 50A and the display device 50B are configured such that red (R), green (G), and blue (B) light are emitted from a layer 57 having light emitting elements.

[0078] A display device according to an embodiment of the present invention has a plurality of pixels arranged in a matrix. Each pixel has one or more sub-pixels. Each sub-pixel has one light-emitting element. For example, the pixel may have three sub-pixels (three colors: R, G, and B, or three colors: yellow (Y), cyan (C), and magenta (M)) or four sub-pixels (four colors: R, G, B, and white (W), or four colors: R, G, B, and Y). The pixel further has a light-receiving element. The light-receiving element may be provided in all pixels or in some pixels. Also, one pixel may have a plurality of light-receiving elements.

[0079] The element layer 55 having transistors preferably includes a first transistor and a second transistor. The first transistor is electrically connected to the light receiving element. The second transistor is electrically connected to the light emitting element.

[0080] The display device according to one embodiment of the present invention may have a function of detecting an object such as a finger touching the display device. For example, as shown in Fig. 9C, light emitted by a light-emitting element in a layer 57 having a light-emitting element is reflected by an object 52 such as a finger touching the display device 50B, and the light-receiving element in a layer 53 having a light-receiving element detects the reflected light. This makes it possible to detect that an object 52 such as a finger has touched the display device 50B.

[0081] The display device according to one embodiment of the present invention may have a function of detecting or capturing an image of an object that is close to (not in contact with) display device 50B, as shown in FIG. 9D.

[0082] 9E, 9F, 9G, 9H and 9I show examples of pixels.

[0083] The pixel shown in Fig. 9E and Fig. 9F has three sub-pixels (three light-emitting elements) of R, G, and B, and a light-receiving element OPD. Fig. 9E is an example in which the three sub-pixels and the light-receiving element OPD are arranged in a 2 × 2 matrix, and Fig. 9F is an example in which the three sub-pixels and the light-receiving element OPD are arranged in a single horizontal row.

[0084] The pixel shown in FIG. 9G has four sub-pixels (four light-emitting elements) of R, G, B, and W, and a light-receiving element OPD.

[0085] The pixel shown in Fig. 9H has three sub-pixels of R, G, and B, a light-emitting element IR that emits infrared light, and a light-receiving element OPD. In this case, it is preferable that the light-receiving element OPD has a function of detecting infrared light. The light-receiving element OPD may have a function of detecting both visible light and infrared light. The wavelength of light detected by the light-receiving element OPD can be determined according to the application of the sensor.

[0086] The pixel shown in FIG. 9I shows two pixels, and has two pixels each having three sub-pixels R, G, and B, and one light receiving element OPD. When the first embodiment is used, the light receiving element OPD is driven in a time-division manner. For example, when driven in a time-division manner, one sub-pixel R emits light after the other sub-pixel R emits light to shift the timing of light emission, thereby imaging with one light receiving element OPD. In addition, in imaging driven in a time-division manner, the sub-pixels B and G do not need to be turned on. FIGS. 9E, 9F, 9G, and 9H show an example of an arrangement in which one OPD is provided per pixel. By providing one OPD per pixel, the resolution of the OPD can be approximately twice as high as the resolution of the pixel of the light emitting element. Also, FIG. 9I shows an example of an arrangement in which one OPD is provided per two pixels, and the total light emitting area can be made wider. Also, even if one OPD is provided per two pixels, the resolution can be approximately the same as when two OPDs are provided by driving in a time-division manner.

[0087] A detailed structure of a display device according to one embodiment of the present invention will be described below with reference to FIG.

[0088] FIG. 10 shows a cross-sectional view of a portion of a display device 50B that captures an image of a subject 52 in contact with the display surface.

[0089] The display device 50B includes a light receiving element OPD, a first light emitting element OLED1, and a second light emitting element OLED2.

[0090] The light receiving element OPD includes a pixel electrode 111 , a common layer 112 , an active layer 113 , a common layer 114 , and a common electrode 115 .

[0091] The first light-emitting element OLED1 includes a pixel electrode 192, a common layer 112, a light-emitting layer 193a, a common layer 114, and a common electrode 115.

[0092] The second light-emitting element OLED 2 includes a pixel electrode 191 , a common layer 112 , a light-emitting layer 193 b , a common layer 114 , and a common electrode 115 .

[0093] The pixel electrode 111, the pixel electrodes 191, 192, the common layer 112, the active layer 113, the light-emitting layers 193a, 193b, the common layer 114, and the common electrode 115 may each have a single-layer structure or a multilayer structure.

[0094] The pixel electrode 111 and the pixel electrodes 191 and 192 are located on an insulating layer 214. The pixel electrode 111, the pixel electrode 191, and the pixel electrode 192 can be formed of the same material in the same process.

[0095] The common layer 112 is located on the pixel electrodes 111, 191, and 192. The common layer 112 is a layer used in common by the light receiving element OPD and the light emitting elements OLED1 and OLED2.

[0096] The active layer 113 overlaps with the pixel electrode 111 through the common layer 112. The light-emitting layer 193b overlaps with the pixel electrode 191 through the common layer 112. The active layer 113 has a first organic compound, and the light-emitting layers 193a and 193b have a second organic compound different from the first organic compound.

[0097] The common layer 114 is located on the common layer 112, the active layer 113, and the light emitting layers 193a and 193b. The common layer 114 is a layer used in common by the light receiving element OPD and the light emitting elements OLED1 and OLED2.

[0098] The common electrode 115 has a portion overlapping with the pixel electrode 111 via the common layer 112, the active layer 113, and the common layer 114. The common electrode 115 also has a portion overlapping with the pixel electrode 191 via the common layer 112, the light-emitting layers 193a and 193b, and the common layer 114. The common electrode 115 is a layer shared by the light-receiving element OPD and the light-emitting elements OLED1 and OLED2.

[0099] In the display device of the present embodiment, an organic compound is used for the active layer 113 of the light receiving element OPD. The layers of the light receiving element OPD other than the active layer 113 can be configured in common with the light emitting element OLED1 (first EL element) and the light emitting element OLED2 (second EL element). Therefore, the light receiving element OPD can be formed in parallel with the formation of the light emitting element OLED1 and the light emitting element OLED2 by simply adding a process of forming the active layer 113 to the manufacturing process of the light emitting element OLED1 and the light emitting element OLED2. In addition, the light emitting element OLED1, the light emitting element OLED2, and the light receiving element OPD can be formed on the same substrate. Therefore, the light receiving element OPD can be built into the display device without significantly increasing the manufacturing process.

[0100] In the display device 50B, the light receiving element OPD, the light emitting element OLED1, and the light emitting element OLED2 have a common configuration, except that the active layer 113 of the light receiving element OPD, the light emitting layer 193a of the light emitting element OLED1, and the light emitting layer 193b of the light emitting element OLED2 are separately manufactured. However, the configuration of the light receiving element OPD, the light emitting element OLED1, and the light emitting element OLED2 is not limited to this. The light receiving element OPD, the light emitting element OLED1, and the light emitting element OLED2 may have layers that are separately manufactured in addition to the active layer 113 and the light emitting layers 193a and 193b. It is preferable that the light receiving element OPD, the light emitting element OLED1, and the light emitting element OLED2 have one or more layers that are used in common (common layers). This allows the light receiving element OPD to be built into the display device without significantly increasing the number of manufacturing steps.

[0101] The display device 50B has a light receiving element OPD, a light emitting element OLED1, a light emitting element OLED2, a transistor 41, a transistor 42, a transistor 43, and the like between a pair of substrates (a first substrate 51 and a second substrate 59).

[0102] In the light receiving element OPD, the common layer 112, the active layer 113, and the common layer 114, which are located between the pixel electrode 111 and the common electrode 115, can also be called organic layers (layers containing an organic compound). The pixel electrode 111 preferably has a function of reflecting visible light. The end of the pixel electrode 111 is covered with a partition wall 216. The common electrode 115 has a function of transmitting visible light.

[0103] The light receiving element OPD has a function of detecting light. Specifically, the light receiving element OPD is a photoelectric conversion element that receives light incident from the outside of the display device 50B and converts the light into an electric signal. The light received by the light receiving element OPD can also be said to be light emitted by the light emitting element 190 and reflected by an object.

[0104] A first light-shielding layer 45 and a second light-shielding layer 44 are provided on the surface of the second substrate 59 facing the first substrate 51. The first light-shielding layer 45 has openings at a position overlapping the light-receiving element OPD and a position overlapping the light-emitting element 190. By providing the first light-shielding layer 45, it is possible to control the range in which the light-receiving element OPD detects light.

[0105] The first light-shielding layer 45 and the second light-shielding layer 44 may be made of a material that blocks light emitted from the light-emitting element. The first light-shielding layer 45 and the second light-shielding layer 44 preferably absorb visible light. For the first light-shielding layer 45 and the second light-shielding layer 44, for example, a black matrix may be formed using a metal material, or a resin material containing a pigment (such as carbon black) or a dye. The first light-shielding layer 45 and the second light-shielding layer 44 may have a laminated structure of a red color filter, a green color filter, and a blue color filter.

[0106] Here, the light receiving element OPD detects the light emitted by the light emitting element OLED1 and the light emitting element OLED2 reflected by the subject 52, which is the target. However, the light emitted by the light emitting element OLED1 and the light emitting element OLED2 may be reflected in the display device 50B and may be incident on the light receiving element OPD without passing through the target. The first light shielding layer 45 can suppress the influence of such stray light. For example, if the first light shielding layer 45 is not provided, the light emitted by the light emitting element OLED2 may be reflected by the second substrate 59, and the reflected light may be incident on the light receiving element OPD. By providing the first light shielding layer 45, it is possible to suppress the reflected light from being incident on the light receiving element OPD. This reduces noise and increases the sensitivity of the sensor using the light receiving element OPD.

[0107] In addition, the second light-shielding layer 44 is provided at a position that partially overlaps with the light-receiving element OPD. By providing the second light-shielding layer 44, it is possible to obtain a sufficient S / N ratio even when imaging is performed in a time-division manner by shifting the light emission timing of the two light-emitting elements.

[0108] In the light-emitting element OLED1, the common layer 112, the light-emitting layer 193a, and the common layer 114, which are located between the pixel electrode 192 and the common electrode 115, respectively, can also be called EL layers. In the light-emitting element OLED2, the common layer 112, the light-emitting layer 193b, and the common layer 114, which are located between the pixel electrode 191 and the common electrode 115, respectively, can also be called EL layers.

[0109] It is preferable that the pixel electrodes 191 and 192 have a function of reflecting visible light. Ends of the pixel electrodes 191 and 192 are covered with a partition wall 216. The pixel electrodes 111 and 191 are electrically insulated from each other by the partition wall 216. The pixel electrodes 111 and 192 are also electrically insulated from each other by the partition wall 216. The common electrode 115 has a function of transmitting visible light.

[0110] The light-emitting element OLED1 and the light-emitting element OLED2 have a function of emitting visible light. Specifically, the light-emitting element OLED1 and the light-emitting element OLED2 are electroluminescent elements that emit light to the second substrate 59 side by applying a voltage between the pixel electrode 191 and the common electrode 115 or between the pixel electrode 192 and the common electrode 115 (see emission 21).

[0111] The pixel electrode 111 is electrically connected to the source or drain of the transistor 41 through an opening provided in the insulating layer 214. An end of the pixel electrode 111 is covered with a partition wall 216.

[0112] The pixel electrode 191 is electrically connected to a source or drain of the transistor 42 through an opening provided in the insulating layer 214. An end of the pixel electrode 191 is covered with a partition wall 216. The transistor 42 has a function of controlling the driving of the light-emitting element OLED2.

[0113] The pixel electrode 192 is electrically connected to a source or a drain of the transistor 43 through an opening provided in the insulating layer 214. An end of the pixel electrode 192 is covered with a partition wall 216. The transistor 43 has a function of controlling driving of the light-emitting element OLED1.

[0114] The transistor 41, the transistor 42, and the transistor 43 are provided in the same layer (a layer on the first substrate 51 in FIG. 10).

[0115] At least a part of the circuit electrically connected to the light receiving element OPD is preferably formed of the same material and in the same process as the circuit electrically connected to the light emitting element 190. This allows the thickness of the display device to be thinner and the manufacturing process to be simplified compared to the case where the two circuits are formed separately.

[0116] The light receiving element OPD and the light emitting element OLED1 and the light emitting element OLED2 are preferably covered with a protective layer 195. In Fig. 10, the protective layer 195 is provided on and in contact with the common electrode 115. By providing the protective layer 195, it is possible to prevent impurities such as water from entering the light receiving element OPD and the light emitting element OLED1 and the light emitting element OLED2, thereby improving the reliability of the light receiving element OPD and the light emitting element 190. In addition, the protective layer 195 and the second substrate 59 are bonded together by the resin layer 58.

[0117] FIG. 11A shows an example of a first pixel circuit having a light receiving element, and FIG. 11B shows an example of a second pixel circuit having a light emitting element.

[0118] 11A includes a light receiving element OPD, a transistor M1, a transistor M2, a transistor M3, a transistor M4, and a capacitor C1. Here, an example is shown in which an organic photodiode is used as the light receiving element OPD.

[0119] The light receiving element OPD has a cathode electrically connected to the wiring V1 and an anode electrically connected to one of the source or drain of the transistor M1. The transistor M1 has a gate electrically connected to the wiring TX and the other of the source or drain electrically connected to one electrode of the capacitor C1, one of the source or drain of the transistor M2, and the gate of the transistor M3. The transistor M2 has a gate electrically connected to the wiring RES and the other of the source or drain electrically connected to the wiring V2. The transistor M3 has one of the source or drain electrically connected to the wiring V3 and the other of the source or drain electrically connected to one of the source or drain of the transistor M4. The transistor M4 has a gate electrically connected to the wiring SE and the other of the source or drain electrically connected to the wiring OUT1.

[0120] A constant potential is supplied to the wiring V1, the wiring V2, and the wiring V3. When the light receiving element OPD is driven with a reverse bias, a potential lower than the potential of the wiring V1 is supplied to the wiring V2. The transistor M2 is controlled by a signal supplied to the wiring RES and has a function of resetting the potential of a node connected to the gate of the transistor M3 to the potential supplied to the wiring V2. The transistor M1 is controlled by a signal supplied to the wiring TX and has a function of controlling the timing at which the potential of the node changes according to the current flowing through the light receiving element OPD. The transistor M3 functions as an amplifying transistor that outputs according to the potential of the node. The transistor M4 is controlled by a signal supplied to the wiring SE and functions as a selection transistor for reading out the output according to the potential of the node to an external circuit connected to the wiring OUT1.

[0121] 11B includes a light-emitting element EL, a transistor M5, a transistor M6, a transistor M7, and a capacitor C2. Here, an example is shown in which a light-emitting diode is used as the light-emitting element EL. In particular, it is preferable to use an organic EL element as the light-emitting element EL.

[0122] Transistor M5 has its gate electrically connected to wiring VG, one of its source or drain electrically connected to wiring VS, and the other of its source or drain electrically connected to one electrode of capacitor element C2 and the gate of transistor M6. One of the source or drain of transistor M6 is electrically connected to wiring V4, and the other is electrically connected to the anode of light-emitting element EL and one of the source or drain of transistor M7. Transistor M7 has its gate electrically connected to wiring MS and the other of its source or drain electrically connected to wiring OUT2. The cathode of light-emitting element EL is electrically connected to wiring V5.

[0123] A fixed potential is supplied to wiring V4 and wiring V5 respectively. The anode side of light-emitting element EL can be set to a high potential and the cathode side to a potential lower than the anode side. Transistor M5 is controlled by the signal supplied to wiring VG and functions as a selection transistor for controlling the selection state of pixel circuit PIX2. Also, transistor M6 functions as a drive transistor for controlling the current flowing through light-emitting element EL according to the potential supplied to its gate. When transistor M5 is in the conductive state, the potential supplied to wiring VS is supplied to the gate of transistor M6, and the emission luminance of light-emitting element EL can be controlled according to that potential. Transistor M7 is controlled by the signal supplied to wiring MS and has the function of outputting the potential between transistor M6 and light-emitting element EL to the outside via wiring OUT2.

[0124] In the display device 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, reduction of power consumption and suppression of heat generation of the display device can be achieved. 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.

[0125] Here, it is preferable that the transistors M1, M2, M3, and M4 in the pixel circuit PIX1, and the transistors M5, M6, and M7 in the pixel circuit PIX2 are transistors that use a metal oxide (oxide semiconductor) in the semiconductor layer in which a channel is formed.

[0126] A transistor using a metal oxide, which has a wider band gap and a lower carrier density than silicon, can achieve an extremely small off-state current. Therefore, the small off-state current allows the charge stored in the capacitor connected in series to the transistor to be held for a long period of time. Therefore, it is preferable to use transistors using an oxide semiconductor for the transistor M1, the transistor M2, and the transistor M5 connected in series to the capacitor C1 or the capacitor C2 in particular. In addition, by using transistors using an oxide semiconductor for the other transistors as well, the manufacturing cost can be reduced.

[0127] Alternatively, the transistors M1 to M7 may each be a transistor in which silicon is used as a semiconductor in which a channel is formed. In particular, the use of silicon with high crystallinity, such as single crystal silicon or polycrystalline silicon, is preferable because high field-effect mobility can be achieved and faster operation can be achieved.

[0128] Alternatively, a structure in which an oxide semiconductor is used for at least one of the transistors M1 to M7 and silicon is used for the remaining transistors may be used.

[0129] Although the transistors are shown as n-channel transistors in FIGS. 11A and 11B, p-channel transistors can also be used.

[0130] The transistors included in the pixel circuit PIX1 and the transistors included in the 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 the pixel circuit PIX1 and the transistors included in the pixel circuit PIX2 are mixed and periodically arranged within one region.

[0131] Also, it is preferable to provide one or more layers having one or both of a transistor and a capacitor element at a position overlapping the light receiving element OPD or the light emitting element EL. Thereby, the effective occupation area of each pixel circuit can be reduced, and a high-definition light receiving portion or display portion can be realized.

[0132] The configuration examples illustrated in the present embodiment, and the corresponding drawings and the like can be implemented by appropriately combining at least a part thereof with other configuration examples, drawings, or the like.

[0133] The present embodiment can be implemented by appropriately combining at least a part thereof with other embodiments described in this specification.

[0134] (Embodiment 3) In the present embodiment, an electronic device according to an aspect of the present invention will be described with reference to FIGS. 12 and 13.

[0135] The electronic device of the present embodiment includes a display device according to an aspect of the present invention. For example, a display device according to an aspect of the present invention can be applied to the display portion of the electronic device. Since the display device according to an aspect of the present invention has a function of detecting light, biometric authentication can be performed at the display portion, or touch or near-touch can be detected. Thereby, the functionality and convenience of the electronic device can be enhanced.

[0136] Examples of electronic devices include electronic devices with relatively large screens, such as television sets, desktop or notebook personal computers, computer monitors, digital signage, large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and audio playback devices.

[0137] The electronic device of this embodiment may have a sensor (including a function to measure force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays).

[0138] The electronic device of the present embodiment can have various functions, such as a function of displaying various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function of displaying a calendar, date, time, etc., a function of executing various software (programs), a wireless communication function, a function of reading out a program or data recorded on a recording medium, etc.

[0139] The electronic device 6500 shown in FIG. 12A is a portable information terminal that can be used as a smartphone.

[0140] The electronic device 6500 includes a housing 6501, a display portion 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508. The display portion 6502 has a touch panel function.

[0141] The display device of one embodiment of the present invention can be applied to the display portion 6502.

[0142] FIG. 12B is a schematic cross-sectional view including the end portion of the housing 6501 on the microphone 6506 side.

[0143] A light-transmitting protective member 6510 is provided on the display surface side of the housing 6501, and a display panel 6511, optical members 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are arranged in the space surrounded by the housing 6501 and the protective member 6510.

[0144] A display panel 6511, an optical member 6512, and a touch sensor panel 6513 are fixed to the protective member 6510 by an adhesive layer (not shown).

[0145] In an area outside the display unit 6502, a part of the display panel 6511 is folded back, and the folded back part is connected to an FPC 6515. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

[0146] The display of one embodiment of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. In addition, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted thereon while suppressing the thickness of the electronic device. In addition, 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, an electronic device with a narrow frame can be realized.

[0147] 13A shows an example of a laptop personal computer 7200. The laptop personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, and the like. A display unit 7000 is incorporated in the housing 7211.

[0148] The display device of one embodiment of the present invention can be applied to the display portion 7000.

[0149] FIG. 13B shows an example of digital signage.

[0150] 13B includes a housing 7301, a display unit 7000, and a speaker 7303. The digital signage 7300 may further include an LED lamp, an operation key (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, and the like.

[0151] In FIG. 13B, the display device of one embodiment of the present invention can be applied to the display portion 7000.

[0152] The larger the display unit 7000, the more information can be provided at one time. Also, the larger the display unit 7000, the more easily it catches people's attention, which can increase the advertising effect of, for example, advertisements.

[0153] Applying a touch panel to the display unit 7000 is preferable because it not only displays images or videos on the display unit 7000 but also allows the user to intuitively operate it. Furthermore, when used for providing information such as route information or traffic information, usability can be improved by intuitive operation.

[0154] 13B, it is preferable that the digital signage 7300 can wirelessly communicate with an information terminal 7311 such as a smartphone carried by a user. For example, advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311. By operating the information terminal 7311, the display on the display unit 7000 can be switched.

[0155] In addition, a game can be executed on the digital signage 7300 using the screen of the information terminal 7311 as an operation means (controller). This allows an unspecified number of users to participate in and enjoy the game at the same time.

[0156] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be implemented in appropriate combination with other configuration examples or drawings.

[0157] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification. [Explanation of symbols]

[0158] 21: light emission, 41: transistor, 42: transistor, 43: transistor, 44: second light-shielding layer, 45: first light-shielding layer, 50A: display device, 50B: display device, 51: first substrate, 52: subject, 53: layer, 55: element layer, 57: layer, 58: resin layer, 59: second substrate, 111: pixel electrode, 112: common layer, 113: active layer, 114: common layer, 115: common electrode, 190: light-emitting element, 191: pixel electrode, 192: pixel electrode, 193a: light-emitting layer, 193b: light-emitting layer, 195: protective layer, 214: insulating layer, 216: partition wall, 6500: electronic device, 6501: housing, 6502: display unit, 6 503: power button, 6504: button, 6505: speaker, 6506: microphone, 6507: camera, 6508: light source, 6510: protective member, 6511: display panel, 6512: optical member, 6513: touch sensor panel, 6515: FPC, 6516: IC, 6517: printed circuit board, 6518: battery, 7000: display unit, 7200: notebook personal computer, 7211: housing, 7212: keyboard, 7213: pointing device, 7214: external connection port, 7300: digital signage, 7301: housing, 7303: speaker, 7311: information terminal device

Claims

1. A substrate; a first transistor having a region located above the substrate; a second transistor having a region above the substrate; a light-emitting element having a region located above the first transistor and electrically connected to the first transistor; an image sensor having a region located above the second transistor and electrically connected to the second transistor; a resin layer having a region located above the light emitting element and a region located above the imaging element; a first light-shielding layer having a region located above the resin layer and having a first opening and a second opening; a second light-shielding layer having a region located above the resin layer and located in the same layer as the first light-shielding layer; the first opening has a region overlapping with the light emitting element, the second opening has a region overlapping with the imaging element, The second light-shielding layer is disposed at the second opening with a gap between it and the first light-shielding layer and has a region overlapping with the imaging element.

2. In claim 1, The display device, wherein the light emitting element is any one of a green light emitting element, a blue light emitting element, a red light emitting element, and an infrared light emitting element.

Images