Display devices, photoelectric conversion devices, electronic devices, lighting devices, mobile objects, and wearable devices

Abstract

To provide a technique advantageous in detecting the luminance of a light emitting element.SOLUTION: A display apparatus comprises a substrate in which a plurality of pixels are arranged. Each of the plurality of pixels includes a light emitting element arranged above a first surface of the substrate, and a light receiving element arranged between the first surface and a second surface of the substrate on an opposite side of the first surface. The light emitting element includes a first electrode, a second electrode arranged between the first surface and the first electrode, and a light emitting layer arranged between the first electrode and the second electrode. In an orthogonal projection with respect to the first surface, the second electrode and the light receiving element at least partially overlap each other.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a display device, a photoelectric conversion device, an electronic device, a lighting device, a moving object, and a wearable device. [Background technology]

[0002] There has been growing interest in display devices that use self-luminous elements such as organic electroluminescence (EL) elements. Due to the image displayed on the display device, etc., there are cases where the degradation of light-emitting elements within a display area is distributed. Patent Document 1 discloses a method in which a light-emitting element is made to function also as a light-receiving element, the amount of light emitted by an adjacent light-emitting element is detected, and input video data when the light-emitting element is made to emit light is corrected based on the detected light-receiving signal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-251201 Summary of the Invention [Problem to be solved by the invention]

[0004] When a light-emitting element is used as a light-receiving element, the effect of the correction may be reduced due to the influence of light incident from outside.

[0005] An object of the present invention is to provide a technique that is advantageous for detecting the luminance of a light-emitting element. [Means for solving the problem]

[0006] In view of the above-described problems, a display device according to an embodiment of the present invention includes a display device having a plurality of pixels arranged therein. No. 1 A display device including a substrate, wherein each of the plurality of pixels is No. 1 a light emitting element disposed on a first surface of a substrate; No. 1a light receiving element disposed between the first surface and a second surface of the substrate opposite to the first surface, The display device further includes a second substrate disposed opposite the second surface, wherein at least a part of a light receiving circuit for driving the light receiving element is disposed on the first substrate, and at least a part of a light emitting circuit for driving the light emitting element is disposed on the second substrate, and the light emitting circuit includes a capacitive element disposed between the second surface and the second substrate and holding a luminance signal corresponding to the luminance at which the light emitting element emits light, The light-emitting element includes a first electrode, a second electrode disposed between the first surface and the first electrode, and a light-emitting layer disposed between the first electrode and the second electrode, and at least a portion of the second electrode and the light-receiving element overlap in an orthogonal projection onto the first surface. and at least a part of the light receiving element and the capacitance element overlap each other. It is characterized by the fact that [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a technique that is advantageous for detecting the luminance of a light-emitting element. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a display device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a circuit diagram showing an example of the configuration of a pixel of the display device in FIG. [Figure 3] 2 is a timing chart for one horizontal scanning period of the display device of FIG. 1. [Figure 4] 2 is a timing chart for one vertical scanning period of the display device of FIG. 1. [Figure 5] FIG. 2 is a plan view showing an example of the configuration of a pixel of the display device of FIG. [Figure 6] FIG. 2 is a cross-sectional view showing an example of the configuration of a pixel of the display device in FIG. [Figure 7] FIG. 2 is a plan view showing an example of the configuration of a pixel of the display device of FIG. [Figure 8] FIG. 2 is a cross-sectional view showing an example of the configuration of a pixel of the display device in FIG. [Figure 9] FIG. 2 is a plan view showing an example of the configuration of a pixel of the display device of FIG. [Figure 10] FIG. 2 is a cross-sectional view showing an example of the configuration of a pixel of the display device in FIG. [Figure 11] FIG. 2 is a cross-sectional view showing an example of the configuration of a pixel of the display device in FIG. [Figure 12] FIG. 2 is a plan view showing an example of the configuration of a pixel of the display device of FIG. [Figure 13] FIG. 2 is a plan view showing an example of the configuration of a pixel of the display device of FIG. [Figure 14] FIG. 2 is a plan view showing an example of the configuration of a pixel of the display device of FIG. [Figure 15] FIG. 2 is a plan view showing an example of the configuration of a pixel of the display device of FIG. [Figure 16] 10A to 10C are diagrams showing application examples of the display device of the present embodiment. [Figure 17] FIG. 1 is a diagram showing an example of a photoelectric conversion device using the display device of the present embodiment. [Figure 18] 1A to 1C are diagrams illustrating examples of electronic devices using the display device of this embodiment. [Figure 19] 10A to 10C are diagrams showing application examples of the display device of the present embodiment. [Figure 20] FIG. 1 is a diagram showing an example of an illumination device using the display device of the present embodiment. [Figure 21] FIG. 1 is a diagram showing an example of a moving object using the display device of the present embodiment. [Figure 22] FIG. 1 is a diagram showing an example of a wearable device using the display device of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0010] A display device according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 15. FIG. 1 is a schematic diagram showing an example of the configuration of a display device 101 according to this embodiment. As shown in FIG. 1, the display device 101 includes a pixel array 103 and a drive circuit arranged around the pixel array 103. The pixel array 103 includes a plurality of pixels 102 arranged two-dimensionally in a matrix. Each of the plurality of pixels 102 includes a light-emitting element and a light-receiving element. Details will be described with reference to FIG. 2, but in this embodiment, the light-emitting element is a self-emitting element such as an organic EL element. In this case, the light-emitting element 201 includes an organic layer including a light-emitting layer between an anode and a cathode. In addition to the light-emitting layer, the organic layer may include one or more of a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer, as appropriate.

[0011] The drive circuit is a circuit for driving each pixel 102. The drive circuit includes, for example, a vertical scanning circuit 104, a signal output circuit 105, and a readout circuit 106. In the pixel array 103, scanning lines 107 to 110 are arranged for each pixel row along the row direction (horizontal direction in FIG. 1). In addition, in the pixel array 103, signal lines 111 and vertical output lines 112 are arranged for each pixel column along the column direction (vertical direction in FIG. 1).

[0012] The scanning lines 107 to 110 are connected to output terminals of the corresponding pixel rows of the vertical scanning circuit 104. The signal lines 111 are connected to output terminals of the corresponding pixel columns of the signal output circuit 105. The vertical output lines 112 are connected to input terminals of the corresponding pixel columns of the readout circuit 106.

[0013] When a video signal is written to each pixel 102 arranged in the pixel array 103, a control signal is input from the vertical scanning circuit 104 to the scanning line 107. When a video signal is written to the pixel 102, the signal output circuit 105 outputs a luminance signal having a voltage corresponding to luminance information.

[0014] Furthermore, the vertical scanning circuit 104 supplies various control signals to the scanning lines 108 to 110 when a signal is output from each pixel 102 arranged in the pixel array 103. The pixels 102 connected to the scanning lines 108 to 110 to which the control signals are supplied output pixel signals to the corresponding vertical output lines 112. The vertical scanning circuit 104 inputs the control signals to the scanning lines 108 to 110 in sequence, whereby the pixel signals from each pixel 102 are output to the vertical output lines 112 in sequence.

[0015] Fig. 2 is a circuit diagram showing an example of the configuration of a pixel 102 arranged in the display device 101 of Fig. 1. As shown in Fig. 2, the pixel 102 includes a light-emitting element 201, a drive transistor 202, a write transistor 203, a capacitor 204, a light-receiving element 205, a transfer transistor 206, a reset transistor 207, an amplifier transistor 208, and a selection transistor 209. Here, a circuit including the drive transistor 202, the write transistor 203, and the capacitor 204 arranged to drive the light-emitting element 201 may be referred to as a light-emitting circuit. Also, a circuit including the transfer transistor 206, the reset transistor 207, the amplifier transistor 208, and the selection transistor 209 arranged to drive the light-receiving element 205 may be referred to as a light-receiving circuit.

[0016] In this embodiment, a case will be described in which a driving transistor 202 is connected to the anode of a light-emitting element 201, all transistors involved in driving the light-emitting element 201 are P-type transistors, and all transistors involved in driving the light-receiving element 205 are N-type transistors. However, the combination of transistors is not limited to the configuration shown in FIG. 2. The polarities and conductivity types of the light-emitting element, light-receiving element, and transistors may be reversed in part or all. The supplied potentials and connections may be changed as appropriate in accordance with the polarities and conductivity types of the light-emitting element, light-receiving element, and transistors. In other words, the total number of transistors and capacitors and the combination of transistor conductivity types are merely examples and can be changed as appropriate depending on the specifications required for the display device 101.

[0017] Here, in this specification, when it is expressed that a transistor is connected between element A and element B, it means that one of the two main terminals (source or drain) of the transistor is connected to element A, and the other of the two main terminals of the transistor is connected to element B. In other words, when it is expressed that a transistor is connected between element A and element B, it does not include the case where the control terminal (gate electrode) of the transistor is connected to at least one of element A and element B.

[0018] In a specific configuration of the pixel 102, one of the two main terminals of the driving transistor 202 is connected to one (anode) of the two main terminals of the light-emitting element 201. The other of the two main terminals of the driving transistor 202 is connected to a power supply potential 212 (for example, Vdd). Therefore, it can be said that the driving transistor 202 is connected between the light-emitting element 201 and the power supply potential 212. The other of the two main terminals of the light-emitting element 201 (cathode) is connected to a power supply potential 211 (for example, Vss).

[0019] One of the two main terminals of the write transistor 203 is connected to the control terminal of the drive transistor 202, and the other is connected to the signal line 111. Therefore, the write transistor 203 is connected between the drive transistor 202 and the signal line 111. The control terminal of the write transistor 203 is connected to the scanning line 107. A capacitive element 204 that holds a luminance signal (luminance signal voltage Vsig) corresponding to the luminance at which the light emitting element 201 emits light is connected between the control terminal of the drive transistor 202 and the other of the two main terminals (source).

[0020] One of the two main terminals of the transfer transistor 206 is connected to one of the main terminals (cathode) of the light receiving element 205, and the other is connected to the control terminal of the amplification transistor 208. One of the two main terminals of the amplification transistor 208 is connected to a power supply potential 213, and the other is connected to one of the two main terminals of the selection transistor 209. The power supply potential 213 may be the same potential (e.g., Vdd) as the power supply potential 212, or may be a different potential. One of the two main terminals of the reset transistor 207 is connected to the control terminal of the amplification transistor 208 and the other of the two main terminals of the transfer transistor 206, and the other is connected to the power supply potential 213. The other of the two main terminals of the selection transistor 209 is connected to the vertical output line 112, and the control terminal of the selection transistor 209 is connected to the scanning line 110. The other of the two main terminals of the light receiving element 205 (anode) is connected to the power supply potential 211. A capacitor 210 (floating diffusion capacitor) is connected to the connection node between the control terminal of the amplifier transistor 208 and one of the two main terminals of the reset transistor 207, and functions as a storage section for the charge generated in the light receiving element 205. The capacitor 210 may be a parasitic capacitance of the transfer transistor 206, the reset transistor 207, the amplifier transistor 208, or a wiring pattern connecting these transistors. In FIG. 2, the capacitor 210 is shown as a capacitive element.

[0021] 3 is a timing diagram showing an example of operation of the pixel 102 shown in FIG. 2 in one horizontal scanning period. Here, FIG. 3 shows line-sequential light emission operation and line-sequential light reception operation. The period before time t1 is the light emission period of the light emitting element 201 and the light reception period of the light receiving element 205 in the (n-1)th frame. From time t1 to t10, luminance information is written to the light emitting element 201 in the nth frame, and the light receiving element 205 outputs a signal charge corresponding to the amount of light emitted by the light emitting element 201 in the (n-1)th frame to the vertical output line 112.

[0022] At time t 1 , the vertical scanning circuit 104 changes the scanning line 109 from a low signal to a high signal, turning on the reset transistor 207 and discharging the charge stored in the capacitor 210 to the power supply potential 213 .

[0023] Next, at time t2, the luminance signal voltage Vsig corresponding to the luminance information is set from the signal output circuit 105 to the signal line 111.

[0024] When the luminance signal voltage Vsig is set on the signal line 111, at time t3, the vertical scanning circuit 104 transitions the scanning line 107 from a High signal to a Low signal, thereby turning on the write transistor 203 and writing the luminance signal voltage Vsig to the control terminal of the drive transistor 202. As a result, a drive current corresponding to the luminance signal voltage Vsig flows from the drive transistor 202 to the light emitting element 201.

[0025] Next, at time t4, the vertical scanning circuit 104 changes the scanning line 109 from a High signal to a Low signal, thereby turning off the reset transistor 207. This completes the resetting of the capacitor 210.

[0026] When the resetting of the capacitor 210 is completed, at time t5, the vertical scanning circuit 104 transitions the scanning line 110 from a low signal to a high signal, thereby turning on the selection transistor 209 and electrically connecting the amplification transistor 208 to the vertical output line 112. As a result, the reset potential (N signal) of the capacitor 210 buffered by the amplification transistor 208 is output to the vertical output line 112.

[0027] Next, at time t6, the vertical scanning circuit 104 transitions the scanning line 108 from a low signal to a high signal, thereby turning on the transfer transistor 206 and transferring the charge accumulated in the light receiving element 205 to the capacitor 210. The light receiving element 205 photoelectrically converts and accumulates signal charge that is roughly proportional to the amount of light emitted by the light emitting element 201. Therefore, by reading out the charge of the light receiving element 205, data that can be used to correct deterioration or defects in the light emitting element 201 can be obtained.

[0028] At time t7, the vertical scanning circuit 104 changes the scanning line 108 from a high signal to a low signal, thereby turning off the transfer transistor 206 and completing the transfer of the charge to the capacitor 210.

[0029] At time t8, the signal charge accumulated in the light receiving element 205 is converted into a voltage (S signal) by the amplification transistor 208 and read out from the vertical output line 112. By taking the difference between the N signal and S signal obtained at time t5, a signal with suppressed noise components can be obtained.

[0030] Next, at time t9, the vertical scanning circuit 104 transitions the scanning line 110 from a High signal to a Low signal, turning off the selection transistor 209 and disconnecting the electrical connection between the vertical output line 112 and the amplification transistor 208.

[0031] At time t10, the vertical scanning circuit 104 transitions the scanning line 107 from a low signal to a high signal, turning off the writing transistor 203 and completing the writing of the luminance signal voltage Vsig to the control terminal of the driving transistor 202. A potential corresponding to the luminance signal voltage Vsig is held in the capacitive element 204 connected between the gate and source of the driving transistor 202.

[0032] 4 is a timing diagram showing an example of operation of the pixel 102 shown in FIG. 2 during one vertical scanning period. At time t11, the luminance signal voltage Vsig is written to the light-emitting elements 201 arranged in the first row, and the N and S signals are read from the light-receiving elements 205 arranged in the first row. From time t12 to time tN, as at time t11, the luminance signal voltage Vsig is written to the light-emitting elements 201 arranged in the corresponding rows, and the N and S signals are read from the light-receiving elements 205. The writing of the luminance signal voltage Vsig to the light-emitting elements 201 and the reading of the N and S signals from the light-receiving elements 205 operate as described above with reference to FIG. 3.

[0033] The signal output from the light receiving element 205 has a value that generally corresponds to the light emission luminance of the light emitting element 201. Therefore, by comparing the luminance information for the light emitting element 201 input to the display device 101 with the signal output from the light receiving element 205, it is possible to obtain information such as deterioration of the light emitting element 201 and luminance unevenness within the surface of the pixel array 103. By correcting the luminance information data input to the display device 101 using the information such as deterioration and luminance unevenness of the light emitting element 201, it is possible to display an image in which the deterioration and luminance unevenness of the light emitting element 201 have been corrected. In other words, deterioration in the image quality of the image displayed on the display device 101 can be suppressed.

[0034] 4, the driving rows of the light emitting element 201 and the light receiving element 205 are synchronized, but this is not limiting. For example, in the display device 101, when the light emitting element 201 is caused to emit light at high luminance, the light receiving element 205 may undergo signal saturation, making it impossible to obtain correction data. In this case, the driving cycle of the light receiving element 205 may be made faster than the driving cycle of the light emitting element 201, thereby shortening the time for signal accumulation, thereby preventing the light receiving element 205 from becoming signal saturated.

[0035] Next, the layout of the pixel 102 of the display device 101 that operates as described above will be described. Figures 5 and 6 are a plan view and a cross-sectional view, respectively, showing an example of the configuration of the pixel 102. Figure 6 shows a cross section taken along line A-A' in the plan view of Figure 5. Although Figure 5 shows only the planar layout of one pixel 102, in reality, the layout shown in Figure 5 is repeated periodically at a predetermined pitch in the row and column directions.

[0036] The drive transistor 202 includes a gate electrode 502, a P-type diffusion layer 512 (drain), and a P-type diffusion layer 522 (source). The write transistor 203 includes a gate electrode 503, a P-type diffusion layer 513 (drain), and a P-type diffusion layer 523 (source). A gate electrode 506 indicates the gate electrode of the transfer transistor 206, a gate electrode 507 indicates the gate electrode of the reset transistor 207, a gate electrode 508 indicates the gate electrode of the amplifier transistor 208, and a gate electrode 509 indicates the gate electrode of the select transistor 209.

[0037] The pixels 102 are formed on a substrate 610. For example, a silicon substrate using silicon (Si) may be used as the substrate 610. As shown in Fig. 6, the light emitting element 201 is disposed on a surface 651 of the two main surfaces of the substrate 610, and the light receiving element 205 is disposed between the surface 651 and a surface 652 opposite to the surface 651.

[0038] The light receiving element 205 is + The buried photodiode includes a P-type semiconductor region 603 formed in a well 601 and in contact with a surface 651 of a substrate 610, and an N-type semiconductor region 604 provided below the P-type semiconductor region 603. The semiconductor region 604 is a charge accumulation layer for accumulating signal charges (electrons) generated in the light receiving element 205.

[0039] An interlayer insulating film 622 is disposed on a surface 651 of the substrate 610, and one or more metal wiring layers 623 are disposed within the interlayer insulating film 622. In the configuration shown in FIG. 6, three metal wiring layers 623 are disposed, but the number of metal wiring layers 623 is not limited to this and may be two or fewer, or four or more. Conductive plugs 624 are disposed between the metal wiring layers 623, between the metal wiring layer 623 and the transistors or the like formed on the substrate 610, and between the metal wiring layer 623 and the light-emitting element 201, as appropriate, for electrical connection. The interlayer insulating film 622 may be formed using various dielectric materials such as silicon oxide or silicon nitride. Not only inorganic materials but also organic materials may be used for the interlayer insulating film 622. Furthermore, different materials may be used for the interlayer insulating film 622 depending on the distance from the surface 651 of the substrate 610. In other words, the interlayer insulating film 622 may have a stacked structure. The metal wiring layer 623 and the conductive plugs 624 are made of, for example, copper (Cu), tungsten (W), aluminum (Al), or the like.

[0040] On the surface 651 side of the substrate 610, there are arranged N-type transistors (e.g., transfer transistor 206) that drive the light receiving element 205, and P-type transistors (e.g., drive transistor 202, write transistor 203) in an N-type semiconductor well 602 that drive the light emitting element 201. Each of the transistors may be a CMOS transistor formed by a general CMOS process.

[0041] The capacitance element 204 has a structure including an interlayer insulating film 622 (for example, a silicon oxide film) between an electrode 504 and an electrode 514. The electrode 504 is connected to a P-type diffusion layer 522 (source) of the driving transistor 202, and the electrode 514 is connected to a gate electrode 502 of the driving transistor 202.

[0042] The light-emitting element 201 includes an electrode 620 (cathode), an electrode 501 (anode) disposed between the surface 651 of the substrate 610 and the electrode 620, and a light-emitting layer 621 disposed between the electrode 620 and the electrode 501. The electrode 620 and the light-emitting layer 621 may be shared by multiple pixels 102 as shown in FIG. 6. For example, the electrode 620 and the light-emitting layer 621 may be formed integrally over the entire surface of the pixel array 103. On the other hand, the electrode 501 is disposed for each light-emitting element 201 (pixel 102) and may be referred to as an individual electrode. The electrode 501 disposed for each light-emitting element 201 (pixel 102) may determine the light-emitting position and light-emitting shape of the light-emitting element 201. A transparent conductive material that transmits light generated in the light-emitting layer 621 may be used for the electrode 620. Metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide may be used as the transparent conductive material. The electrode 501 is made of a metal material such as tungsten (W), aluminum (Al), platinum (Pt), or palladium (Pd). The above-mentioned interlayer insulating film 622 is disposed between the surface 651 of the substrate 610 and the electrode 501. In this embodiment, a bank 625 made of a dielectric material is disposed so as to cover the outer edge of the electrode 501. The bank 625 prevents current flowing between the electrode 501 and the electrode 620 from leaking to adjacent pixels 102.

[0043] 5 and 6, in an orthogonal projection onto a surface 651 of the substrate 610, the electrode 501 and the light receiving element 205 at least partially overlap with each other. By arranging the electrode 501 so as to overlap the light receiving element 205, the influence of external light incident on the light receiving element 205 can be reduced. The light emitted by the light emitting element 201 includes a component that propagates from the display device 101 to the outside (air) and a component that is reflected due to a difference in refractive index between the light emitting layer 621 and the electrode 620 or between the electrode 620 and the air (between a protective layer, a color filter, or the like on the electrode 620 and the respective layers) and returns to the light emitting layer 621. As shown in FIG. 6, a portion 650 of the reflected component (reflected light) passes through a region where the electrode 501 and the light receiving element 205 do not overlap with each other in an orthogonal projection onto the surface 651 of the substrate 610, and is incident on the light receiving element 205. A portion 650 of the reflected light corresponding to the luminance of the light emitting element 201 is incident on the light receiving element 205, and therefore a signal output corresponding to the luminance of the light emitting element 201 can be obtained from the light receiving element 205.

[0044] When a light-emitting element also functions as a light-receiving element, as in Patent Document 1, for example, the light-emitting element may be affected by external light when emitting light at low brightness, making it difficult to accurately estimate the amount of light emitted by the light-emitting element, which may result in reduced accuracy in correction based on the detected signal. On the other hand, in this embodiment, the electrode 501 and the light-receiving element 205 overlap in an orthogonal projection onto the surface 651 of the substrate 610. Furthermore, the light-emitting element 201 and the light-receiving element 205 do not overlap in an orthogonal projection onto a plane (cross section) perpendicular to the surface 651 of the substrate 610. This makes it possible to obtain a signal corresponding to the light emitted by the light-emitting element 201 while suppressing the influence of external light incident on the light-receiving element 205. Furthermore, in the configurations shown in FIGS. 5 and 6, the light-receiving element 205 and the capacitive element 204 of the light-emitting circuit are positioned so that they do not overlap in an orthogonal projection onto the surface 651 of the substrate 610. Therefore, a portion 650 of the reflected light of the light emitted by the light-emitting element 201 is more likely to be incident on the light-receiving element 205 than when the light-receiving element 205 and the capacitive element 204 overlap. In other words, by using the structure of the pixel 102 shown in this embodiment, it is possible to effectively correct deterioration of the light-emitting element 201 and uneven brightness within the surface of the pixel array 103. As a result, it is possible to improve the quality of the display image displayed on the display device 101.

[0045] Next, modified examples of the pixel 102 will be described with reference to Figures 7 and 8. Figure 7 is a plan view of the pixel 102, and Figure 8 is a cross-sectional view taken along line A-A' in Figure 7. The following will mainly describe configurations that differ from the layouts shown in Figures 5 and 6. In the configurations shown in Figures 5 and 6, the light receiving element 205 is disposed between adjacent light emitting elements 201, and so there is a possibility that light will be incident from the adjacent light emitting elements 201 and detected by the light receiving element 205.

[0046] 7 and 8, a light-shielding layer 701 is disposed in a region of the interlayer insulating film 622 that overlaps with the outer edge of each of the plurality of pixels 102 in orthogonal projection onto the surface 651 of the substrate 610. By disposing the light-shielding layer 701 between the adjacent pixels 102, an effect of reducing optical crosstalk, in which light emitted by the light-emitting element 201 is incident on the light-receiving element 205 of the adjacent pixel 102, can be obtained.

[0047] The light-shielding layer 701 can be made of the same material as the metal wiring layer 623 and the conductive plugs 624. In other words, the light-shielding layer 701 can be formed simultaneously when the metal wiring layer 623 and the conductive plugs 624 are formed. By using such a process, it is possible to suppress an increase in the number of processes due to the provision of the light-shielding layer 701. The light-shielding layer 701 may be configured to be connected by the conductive plugs 624 that are connected from the metal wiring layer 623 immediately above the substrate 610 to a pattern in the same layer as the electrodes 501 of the light-emitting element 201 in a direction intersecting the surface 651 of the substrate 610.

[0048] Further modified examples of the pixel 102 will be described with reference to Figures 9 and 10. Figure 9 is a plan view of the pixel 102, and Figure 10 is a cross-sectional view taken along line A-A' in Figure 9. The following mainly describes configurations that differ from the layouts shown in Figures 7 and 8. In the configuration shown in Figure 7, optical crosstalk between adjacent pixels 102 can be suppressed, but reflected light from the light-shielding layer 701 may enter an area other than the light-receiving element 205, potentially reducing the sensitivity of the light-receiving element 205.

[0049] 9 and 10 , in the pixel 102, an optical waveguide 901 is arranged in a region of the interlayer insulating film 622 that overlaps with the light receiving element 205 in an orthogonal projection onto the surface 651 of the substrate 610. The optical waveguide 901 is arranged so that its bottom on the substrate 610 side faces the light receiving element 205. The optical waveguide 901 is made of a material having a higher refractive index than the surrounding interlayer insulating film 622 and is formed into a truncated cone shape, and has a function of guiding a portion 650 of reflected light of light emitted by the light emitting element 201 to the light receiving element 205. For example, when silicon oxide or the like is used for the interlayer insulating film 622, a material such as silicon nitride may be used for the optical waveguide 901.

[0050] By providing the optical waveguide 901, it becomes possible to efficiently guide the light reflected by the light-shielding layer 701 to the light receiving element 205. This makes it possible to improve the sensitivity of the light receiving element 205 to the light emitted from the light emitting element 201. As a result, it is possible to reduce the influence of external light on the light receiving element 205, and it is possible to detect the emission luminance of the light emitting element 201 to be detected with high accuracy.

[0051] In the structure of pixel 102 described so far, a light emitting circuit for driving light emitting element 201 and a light receiving circuit for driving light receiving element 205 are arranged on one substrate 610. Because a light receiving circuit such as drive transistor 202 and a light emitting circuit such as transfer transistor 206 are arranged on one substrate 610, there is a limit to how miniaturized pixel 102 can be. Therefore, a method for achieving miniaturization of pixel 102 by distributing and arranging the elements constituting the light receiving circuit and the light emitting circuit on two substrates will be described.

[0052] 11 is a cross-sectional view of a pixel 102 of a display device 101 having a structure in which two substrates 610 and 660 are stacked. As described above, the substrate 610 is, for example, a silicon substrate made of silicon (Si). The substrate 660, which is arranged so as to face the surface 652 of the substrate 610, may be made of, for example, silicon (Si) or glass. In this embodiment, the substrate 660 is, like the substrate 610, a silicon substrate made of silicon (Si).

[0053] The pixel 102 shown in FIG. 11 includes a light-emitting element 201 disposed on a surface 651 of a substrate 610 and a light-receiving element 205 disposed between a surface 651 and a surface 652 of the substrate 610. The light-emitting element 201 includes an electrode 620, an electrode 501 disposed between the surface 651 of the substrate 610 and the electrode 620, and a light-emitting layer 621 disposed between the electrode 620 and the electrode 501. As in the configurations described above, the electrode 620 and the light-emitting layer 621 may be shared by multiple pixels 102 as shown in FIG. 11, or the electrode 501 may be divided for each light-emitting element 201 (pixel 102). As in the above, a bank 625 made of a dielectric may be disposed so as to cover the outer edge of the electrode 501. An interlayer insulating film 627 may be disposed between the substrate 610 and the electrode 501 to electrically isolate the substrate 610 and the electrode 501.

[0054] A light receiving element 205 is disposed on the substrate 610. In addition, as shown in Fig. 11 , a transfer transistor 206 is disposed on a surface 652 of the substrate 610. In this embodiment as well, the electrode 501 and the light receiving element 205 at least partially overlap with each other in orthogonal projection onto a surface 651 of the substrate 610.

[0055] An interlayer insulating film 622 is disposed on a surface 652 of the substrate 610 facing the substrate 660, and one or more metal wiring layers 623 are disposed in the interlayer insulating film 622. Conductive plugs 624 are disposed between the metal wiring layers 623, between the metal wiring layer 623 and transistors or the like formed on the substrate 610, and between the metal wiring layer 623 and the light-emitting element 201, as appropriate, for electrical connection. The substrate 660 has a surface 661 facing the substrate 610 and a surface 662 opposite the surface 661. An interlayer insulating film 672 is disposed on the surface 661 of the substrate 660, and one or more metal wiring layers 673 are disposed in the interlayer insulating film 672. Conductive plugs 674 are disposed between the metal wiring layers 673 and between the metal wiring layer 673 and transistors or the like formed on the substrate 660, as appropriate, for electrical connection.

[0056] The interlayer insulating films 622 and 672 may be made of various dielectric materials such as silicon oxide and silicon nitride. The interlayer insulating films 622 and 672 may be made of organic materials as well as inorganic materials. The interlayer insulating films 622 and 672 may be made of different materials depending on the distance from the surface 651 of the substrate 610. In other words, the interlayer insulating films 622 and 672 may have a layered structure. The metal wiring layers 623 and 673 and the conductive plugs 624 and 674 may be made of, for example, copper (Cu), tungsten (W), aluminum (Al), or the like.

[0057] The metal wiring layer 623 of the substrate 610 and the metal wiring layer 673 of the substrate 660 are electrically connected by directly bonding the metal wiring layer 623 and the metal wiring layer 673 in some regions. For example, the uppermost metal wiring layer 623 and the metal wiring layer 673 may be electrically connected by Cu-Cu bonding.

[0058] An N-type transistor (e.g., a transfer transistor 206) that drives the light-receiving element 205 formed in the substrate 610 is disposed on the surface 652 side of the substrate 610. On the surface 661 side of the substrate 660, P-type transistors (e.g., a drive transistor 202 and a write transistor 203) are disposed in an N-type semiconductor well that drives the light-emitting element 201. Each transistor may be a CMOS transistor formed by a general CMOS process. The gate insulating film thickness of a transistor in the light-receiving circuit, such as the transfer transistor 206, that is disposed on the substrate 610 may be the same as or different from the gate insulating film thickness of a transistor in the light-emitting circuit, such as the drive transistor 202, that is disposed on the substrate 660. Since transistors are formed on the two substrates 610 and 660, transistors with different gate insulating film thicknesses can be easily formed by allocating the transistors to either of the two substrates 610 and 660 according to the specifications required for each transistor.

[0059] In this embodiment, transistors of a light receiving circuit that drives the light receiving element 205 are arranged on the substrate 610, and transistors of a light emitting circuit that drives the light emitting element 201 are arranged on the substrate 660. However, this is not limited to this. Some of the transistors that make up the light emitting circuit may be arranged on the substrate 610, and some of the transistors that make up the light receiving circuit may be arranged on the substrate 660. Depending on the specifications of the pixels 102 of the display device 101 and the specifications required for each of the transistors that make up the light receiving circuit and the light emitting circuit, the components may be distributed and arranged on the two substrates 610 and 660 as appropriate.

[0060] Figures 12(a) to 12(c) are plan views corresponding to one pixel 102 of the display device 101 shown in Figure 11. In reality, the layout shown in Figure 12 is repeated periodically at a predetermined pitch in the row and column directions.

[0061] 12(a) is an example of a planar arrangement of a light emitting circuit (drive transistor 202, write transistor 203, and capacitor 204) for driving a light emitting element 201 arranged on a substrate 660. The drive transistor 202 includes a gate electrode 502, a P-type diffusion layer 512 (drain), and a P-type diffusion layer 522 (source). The write transistor 203 includes a gate electrode 503, a P-type diffusion layer 513 (drain), and a P-type diffusion layer 523 (source). The capacitor 204 is arranged so as to partially overlap the drive transistor 202 and the write transistor 203 in orthogonal projection onto a surface 661 of the substrate 660.

[0062] 12(b) is an example of a planar layout of the light receiving element 205 and a light receiving circuit (transfer transistor 206, reset transistor 207, amplifier transistor 208, and select transistor 209) for driving the light receiving element arranged on a substrate 610. A gate electrode 506 indicates the gate electrode of the transfer transistor 206, a gate electrode 507 indicates the gate electrode of the reset transistor 207, a gate electrode 508 indicates the gate electrode of the amplifier transistor 208, and a gate electrode 509 indicates the gate electrode of the select transistor 209.

[0063] In orthogonal projection onto the surface 651 of the substrate 610, the electrode 501 of the light-emitting element 201 and the light-receiving element 205 at least partially overlap each other. By arranging the electrode 501 so as to overlap the light-receiving element 205, the influence of external light on the light-receiving element 205 can be suppressed, as in the above-described configurations.

[0064] 12(c) shows the relationship when the elements are stacked by superimposing the plan view of FIG. 12(a) on the plan view of FIG. 12(b). The capacitance element 204 of the light-emitting circuit is disposed between the surface 652 of the substrate 610 and the surface 661 of the substrate 660, and as shown in FIG. 12, the light-receiving element 205 and the capacitance element 204 may at least partially overlap in orthogonal projection onto the surface 651 of the substrate 610.

[0065] The light emitted by the light-emitting element 201 includes a component that propagates from the display device 101 to the outside (air) and a component that is reflected due to a difference in refractive index between the light-emitting layer 621 and the electrode 620 or between the electrode 620 and the air (between each layer if a protective layer, a color filter, or the like is present on the electrode 620) and returns to the light-emitting layer 621 side. A part of the reflected component (reflected light) passes through a region where the electrode 501 and the light-receiving element 205 do not overlap in orthogonal projection onto the surface 651 of the substrate 610, and is incident on the light-receiving element 205. Since a part of the reflected light corresponding to the luminance of the light-emitting element 201 is incident on the light-receiving element 205, a signal output corresponding to the luminance of the light-emitting element 201 can be obtained from the light-receiving element 205.

[0066] 11 and 12(a) to 12(c), a display device 101 including miniaturized pixels 102 formed by stacking substrates 610 and 660 can also obtain a signal corresponding to the light emitted by the light-emitting element 201 while suppressing the influence of external light incident on the light-receiving element 205. In other words, by using the structure of the pixel 102 shown in FIGS. 11 and 12(a) to 12(c), it is possible to effectively correct deterioration of the light-emitting element 201 and uneven brightness within the surface of the pixel array 103. As a result, it is possible to improve the quality of the image displayed on the display device 101.

[0067] Next, modified examples of the pixel 102 shown in FIGS. 12(a) to 12(c) will be described using FIGS. 13(a) to 13(c). When comparing the areas occupied by the light receiving circuit and the light emitting circuit on the substrates 610 and 660, the area occupied by the light receiving element 205 and the light receiving circuit can be larger than the area occupied by the light emitting circuit in orthogonal projection onto the surface 651 of the substrate 610. This is because the light receiving element 205 requires a relatively large area. Therefore, reducing the number of elements in the light receiving circuit effectively reduces the area of ​​the pixel 102.

[0068] FIG. 13(a) illustrates an example of a light-emitting circuit for driving three light-emitting elements (e.g., a light-emitting circuit for a red light-emitting element, a green light-emitting element, and a blue light-emitting element) for driving the light-emitting element 201 shown in FIG. 12(a). In this case, as shown in the plan view of FIG. 13(b), the light-receiving elements 205a-205c and the transfer transistors 206a-206c (shown as gate electrodes 506a-506c in FIG. 13(b)) corresponding to the light-receiving elements 205a-205c, respectively, are arranged independently. Meanwhile, by sharing the reset transistor 207, the amplifier transistor 208, and the selection transistor 209 (shown as gate electrodes 507-509 in FIG. 13(b)) subsequent to the capacitor 210 (floating diffusion capacitance) among multiple pixels 102, the area of ​​the light-receiving circuit can be reduced. FIG. 13(c) is a diagram showing the relationship between the stacked elements by superimposing the plan views of FIG. 13(a) and FIG. 13(b).

[0069] In this manner, the light receiving elements 205 (light receiving elements 205a to 205c in the configuration shown in FIG. 13(b)) arranged in two or more pixels 102 may share one light receiving circuit (the reset transistor 207, the amplification transistor 208, and the selection transistor 209 in the configuration shown in FIG. 13(b)). In this case, the two or more pixels 102 sharing one light receiving circuit may be pixels that emit light of the same color, or may be pixels that emit light of different colors. Here, emitting light of different colors may mean that the light emitting layers 621 of the light emitting elements 201 themselves emit light of different colors. Alternatively, the light emitting layers 621 may emit light of the same color, but by disposing a color filter or the like on the light emitting layers 621, the pixels 102 of the display device 101 may emit light of different colors.

[0070] The brightness ratio for achieving white balance for pixels 102 that emit different colors of light changes depending on the color temperature. As the color temperature increases, the brightness of blue increases and the brightness of red decreases. When the color temperature is high, the brightness of red decreases compared to other colors, and therefore the signal charge accumulated in the light receiving element 205 that detects the brightness of red light is small, which may result in lower correction accuracy compared to other colors. Therefore, the sensitivity of the light receiving element 205 for each color may be adjusted depending on the color temperature. The display device 101 includes two or more pixels 102 that emit light of different colors (e.g., three types: red, green, and blue). The light receiving sensitivity of the light receiving element 205 arranged in a certain pixel 102 may be different from the light receiving sensitivity of the light receiving element 205 arranged in a pixel that emits light of a color different from that of the pixel 102.

[0071] For example, the areas of the light receiving elements 205 may be different in pixels 102 that emit different light colors. The areas of the light receiving elements 205 can be designed as appropriate according to the white balance designed for the display device 101. In addition, in the case of a display device 101 that is capable of adjusting the white balance, the light receiving sensitivity of the light receiving elements 205 can be changed by configuring the amplification factor of the amplifier arranged in the readout circuit 106 to be adjustable as appropriate. In particular, by setting the sensitivity of the light receiving elements 205 in reverse order with respect to the emission intensity of each color defined by the white balance, it is possible to prevent deterioration of the light emitting elements 201 and a decrease in the accuracy of correction of brightness unevenness within the surface of the pixel array 103.

[0072] Next, further modifications of the pixel 102 shown in Figures 12(a) to 12(c) will be described using Figures 14(a) to 14(c). As described above, when comparing the areas occupied by the light receiving circuit and the light emitting circuit on the substrates 610 and 660, the area occupied by the light receiving element 205 and the light receiving circuit may be larger than the area occupied by the light emitting circuit. Therefore, in order to achieve higher resolution in the display device 101, the repetition pitch of the light receiving circuit and the repetition pitch of the light emitting circuit may be different.

[0073] FIG. 14(a) illustrates an example in which three light-emitting circuits (e.g., light-emitting circuits for red, green, and blue light-emitting elements) for driving the light-emitting elements 201 shown in FIG. 12(a) are illustrated. In this case, as shown in FIG. 14(b), one light-receiving element 205 and one light-receiving circuit (transfer transistor 206, reset transistor 207, amplifier transistor 208, and selection transistor 209, which are shown as gate electrodes 506 to 509 in FIG. 14(b)) are arranged for each light-emitting circuit for driving the three light-emitting elements 201. In other words, multiple pixels 102 may share one light-receiving element 205 and one light-receiving circuit. By arranging the light-receiving circuit and the light-emitting circuit in this manner, the pitch at which the light-emitting circuits are repeatedly arranged differs from the pitch at which the light-receiving circuits are repeatedly arranged. FIG. 14(c) is a diagram illustrating the relationship between the stacked elements by superimposing the plan views of FIG. 14(a) and FIG. 14(b).

[0074] In the configurations shown in FIGS. 14(a) to 14(c), the luminance of three light-emitting elements 201 is detected by one light-receiving element 205. For example, when correcting a display image, the combined light amount of the three light-emitting elements 201 is read out as a signal output (output image) from the light-receiving circuit, and the image to be displayed is compared with the output image to calculate the difference. This makes it possible to obtain correction data for deterioration of each light-emitting element 201. Also, for example, when the display device 101 is started up, pixels 102 of a specific color are made to emit light, and the luminance is detected by the light-receiving element 205. By repeating this for each color, the luminance of the light-emitting element 201 of the pixel 102 corresponding to input data can be obtained, and a correction coefficient for the input data to the display device 101 when displaying an image can be obtained.

[0075] Here, when the luminance of the light-emitting element 201 is extremely low, for example, the amount of light incident on the light-receiving element is small, making it susceptible to noise from external light and the like, which may result in a problem of not being able to maintain sufficient correction accuracy. Furthermore, when the luminance of the light-emitting element is low, the rise of the output signal from the light-receiving element 205 is slow (response speed is slow), which may result in a problem of a long time until the luminance is measured. If the measurement time by the light-receiving element 205 is short, the measurement may be performed before the light-emitting element 201 reaches the emission luminance corresponding to the input data, resulting in an inaccurate correction. The structure of the electrode 501 for solving the above problems will be described with reference to FIG. 15.

[0076] 15, compared to the plan view of FIG. 12(b), an opening 551 is provided in the electrode 501 of the light-emitting element 201. The opening 551 may be filled with a part of the light-emitting layer 621 or a light-transmitting member. When the light-emitting element 201 emits light, a part of the light emitted by the light-emitting element 201 passes through the opening 551 and enters the light-receiving element 205. Therefore, even if the luminance of the light-emitting element 201 is low, the amount of light entering the light-receiving element 205 increases compared to the electrode 501 shown in FIG. 12, so the accuracy of the correction data can be maintained. Furthermore, the light-receiving sensitivity of the light-receiving element 205 for each of the above-mentioned colors may be changed by changing the size of the opening 551.

[0077] As shown in FIG. 15 , when an opening 551 is provided in the electrode 501 and filled with a part of the light-emitting layer 621 or a light-transmitting member, a step may occur around the periphery of the opening 551. If this step causes a disconnection or the like in the light-emitting layer 621, it may affect the reliability of the display device 101 (light-emitting element 201). To reduce the step around the periphery of the opening 551, the electrode 501 may have a laminated structure of a transparent electrode and a light-shielding film such as a metal layer in which the opening 551 is provided. The metal layer functions as a light-shielding film even when its film thickness is relatively thin. For example, the step around the opening 551 can be reduced by laminating a transparent electrode on the metal layer so as to have a predetermined resistance value.

[0078] Alternatively, a material that transmits at least a portion of the light emitted by the light-emitting element 201 may be used as the electrode 501, thereby eliminating the need for the opening 551. In other words, the electrode 501 may transmit a portion of the light generated in the light-emitting layer. Transparent materials that can be used for the electrode 501 include, but are not limited to, metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide.

[0079] In order to obtain information for correcting deterioration of the light emitting element 201 while preventing a decrease in the amount of light emitted from the display device 101 and the influence of external light, the light transmittance of the electrode 501 does not need to be high, and may be relatively low. For example, the light transmittance of the electrode 501 may be 20% or less, or even 10% or less. In addition, for example, when the luminance is 500 cd / m 2 In the case of a display device 101 of this order, if the light transmittance of the electrode 501 is 1% or more, it is possible to obtain information necessary for correcting the light emitting element 201 without being buried in noise from the light receiving element 205. In other words, the transmittance of the electrode 501 for light generated in the light emitting layer 621 may be 1% or more and 20% or less.

[0080] 12(a) to 15, by using a configuration in which the substrates 610 and 660 are stacked, it is possible to reduce the area of ​​the pixel 102 (miniaturize it) compared to when a single substrate 610 is used, while suppressing the influence of external light. As a result, it is possible to achieve high definition in the display device 101.

[0081] Here, actual application examples of the display device 101 of this embodiment and examples in which the display device 101 is applied to a photoelectric conversion device, an electronic device, a lighting device, a mobile object, and a wearable device will be described with reference to FIGS. 16 to 22(b). Other applications of the display device 101 include an exposure light source for an electrophotographic image forming device, a backlight for a liquid crystal display device, and a light-emitting device having a white light source and a color filter. The display device 101 may be an image information processing device having an image input unit that inputs image information from an area CCD, a linear CCD, a memory card, or the like, an information processing unit that processes the input information, and displays the input image on a display unit. Furthermore, the display unit of a camera or inkjet printer may have a touch panel function. The driving method for this touch panel function may be an infrared type, a capacitance type, a resistive film type, or an electromagnetic induction type, and is not particularly limited. The display device may also be used in the display unit of a multifunction printer.

[0082] FIG. 16 is a schematic diagram illustrating an application example of a display device using the display device 101 of this embodiment. The display device 1000 may include a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. The touch panel 1003 and the display panel 1005 are connected to flexible printed circuits FPCs 1002 and 1004. Active elements such as transistors are disposed on the circuit board 1007. The battery 1008 may not be disposed if the display device 1000 is not a portable device, and even if it is a portable device, it does not need to be disposed in this position. The pixel array 103 of the display device 101 described above can be applied to the display panel 1005. The display device 101 functioning as the display panel 1005 is connected to active elements such as transistors disposed on the circuit board 1007 and operates. The circuit board 1007 may correspond to, for example, each of the components of the drive circuits described above.

[0083] The display device 1000 shown in Fig. 16 may be used as a display unit of a photoelectric conversion device (image capture device) having an optical unit with multiple lenses and an image capture element that receives light that has passed through the optical unit and photoelectrically converts it into an electrical signal. The photoelectric conversion device may have a display unit that displays information acquired by the image capture element. The display unit may be a display unit exposed to the outside of the photoelectric conversion device or a display unit located within a viewfinder. The photoelectric conversion device may be a digital camera or a digital video camera.

[0084] FIG. 17 is a schematic diagram illustrating an example of a photoelectric conversion device using the display device 101 of this embodiment. The photoelectric conversion device 1100 may include a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The photoelectric conversion device 1100 may also be called an imaging device. The above-described display device 101 can be applied to the viewfinder 1101, which is a display unit. In this case, the display device 101 may display not only an image to be captured, but also environmental information, imaging instructions, and the like. The environmental information may include the intensity of external light, the direction of external light, the moving speed of the subject, the possibility that the subject will be blocked by an obstruction, and the like.

[0085] Since the timing suitable for capturing an image is often very short, it is better to display information as soon as possible. Therefore, a display device 101 including an organic light-emitting material such as an organic EL element as the light-emitting element 201 can be used in the viewfinder 1101. This is because organic light-emitting materials have a fast response speed. A display device 101 using an organic light-emitting material is more suitable for use than a liquid crystal display device for such devices that require a high display speed.

[0086] The photoelectric conversion device 1100 has an optical section (not shown). The optical section has multiple lenses, which form an image on a photoelectric conversion element (not shown) housed in a housing 1104 that receives light that has passed through the optical section. The focus of the multiple lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically.

[0087] The display device 101 may be used as a display unit of an electronic device. In this case, the display device 101 may have both a display function and an operation function. Examples of the portable terminal include a mobile phone such as a smartphone, a tablet, and a head-mounted display.

[0088] FIG. 18 is a schematic diagram showing an example of an electronic device using the display device 101 of this embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit 1202 may be a biometric recognition unit that recognizes a fingerprint to perform unlocking or the like. A portable device having a communication unit can also be called a communication device. The above-mentioned display device 101 can be applied to the display unit 1201.

[0089] 19(a) and 19(b) are schematic diagrams illustrating application examples of a display device using the display device 101 of this embodiment. FIG. 19(a) illustrates a display device such as a television monitor or a PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The pixel array 103 of the display device 101 described above can be applied to the display unit 1302. The display device 1300 may have a base 1303 that supports the frame 1301 and the display unit 1302. The base 1303 is not limited to the form shown in FIG. 19(a). For example, the bottom edge of the frame 1301 may also serve as the base 1303. The frame 1301 and the display unit 1302 may be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0090] FIG. 19(b) is a schematic diagram illustrating another application example of a display device using the display device 101 of this embodiment. The display device 1310 in FIG. 19(b) is configured to be bendable and is a so-called foldable display device. The display device 1310 has a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. The pixel array 103 of the display device 101 described above can be applied to the first display unit 1311 and the second display unit 1312. The first display unit 1311 and the second display unit 1312 may be a single display unit without any joints. The first display unit 1311 and the second display unit 1312 can be separated by the bending point. The first display unit 1311 and the second display unit 1312 may display different images, or the first display unit and the second display unit may display a single image.

[0091] FIG. 20 is a schematic diagram illustrating an example of an illumination device using the display device 101 of this embodiment. The illumination device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404, and a light diffusion unit 1405. The above-described display device 101 can be applied to the light source 1402. The optical film 1404 may be a filter that improves the color rendering of the light source. The light diffusion unit 1405 can effectively diffuse light from the light source, such as for lighting, and deliver the light over a wide area. If necessary, a cover may be provided on the outermost part. The illumination device 1400 may include both the optical film 1404 and the light diffusion unit 1405, or only one of them.

[0092] The lighting device 1400 is, for example, a device that illuminates a room. The lighting device 1400 may emit white, daylight white, or any other color from blue to red. It may have a dimming circuit that dims these colors. The lighting device 1400 may have a power supply circuit connected to the display device 101 that functions as the light source 1402. The power supply circuit is a circuit that converts AC voltage into DC voltage. White has a color temperature of 4200K, and daylight white has a color temperature of 5000K. The lighting device 1400 may also have a color filter. The lighting device 1400 may also have a heat dissipation unit. The heat dissipation unit dissipates heat inside the device to the outside, and examples of the heat dissipation unit include metal with a high specific heat, liquid silicon, etc.

[0093] FIG. 21 is a schematic diagram of an automobile having a tail lamp, which is an example of a vehicle lamp using the display device 101 of this embodiment. The automobile 1500 has a tail lamp 1501, and may be configured to turn on the tail lamp 1501 when braking or the like is performed. The display device 101 of this embodiment may be used as a headlamp as a vehicle lamp. An automobile is an example of a mobile body, and the mobile body may be a ship, a drone, an aircraft, a railroad vehicle, an industrial robot, or the like. The mobile body may have a body and a lamp provided thereon. The lamp may indicate the current location of the body.

[0094] The above-described display device 101 can be applied to a tail lamp 1501. The tail lamp 1501 may have a protective member that protects the display device 101 functioning as the tail lamp 1501. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, but may be made of polycarbonate or the like. The protective member may also be made by mixing a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like with polycarbonate.

[0095] The automobile 1500 may have a body 1503 and a window 1502 attached thereto. The window may be a window for checking the front and rear of the automobile, or may be a transparent display. The transparent display may be the above-described display device 101 in which the light-emitting layer 621 contains an organic light-emitting material and functions as a light-emitting device. In this case, constituent materials of the electrodes and the like of the display device 101 are made of transparent materials.

[0096] 22(a) and 22(b), further application examples of the display device 101 of each of the above-described embodiments will be described. The display device 101 can be applied to systems that can be worn as a wearable device, such as smart glasses, a head-mounted display (HMD), or smart contact lenses. An image capturing and displaying device used in such application examples has an image capturing device capable of photoelectrically converting visible light and a light emitting device capable of emitting visible light.

[0097] 22(a) illustrates glasses 1600 (smart glasses) according to one application example. An imaging device 1602 such as a CMOS sensor or SPAD is provided on the front side of a lens 1601 of the glasses 1600. Furthermore, the display device 101 according to each of the above-described embodiments is provided on the back side of the lens 1601.

[0098] The glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the image capture device 1602 and the display device 101 according to each embodiment. The control device 1603 also controls the operations of the image capture device 1602 and the display device 101. The lens 1601 is formed with an optical system for focusing light onto the image capture device 1602.

[0099] FIG. 22(b) illustrates glasses 1610 (smart glasses) according to one application example. The glasses 1610 include a control device 1612, which is equipped with an imaging device corresponding to the imaging device 1602 and a display device 101. A lens 1611 includes an optical system for projecting light emitted from the imaging device in the control device 1612 and the display device 101, and an image is projected onto the lens 1611. The control device 1612 functions as a power source for supplying power to the imaging device and the display device 101 and controls the operation of the imaging device and the display device 101. The control device 1612 may also include a gaze detection unit that detects the gaze of the wearer. Infrared light may be used for gaze detection. The infrared light emitter emits infrared light toward the eyeball of a user gazing at a displayed image. An imaging unit having a light receiving element detects the emitted infrared light reflected from the eyeball, thereby obtaining an image of the eyeball. By providing a reduction means for reducing the amount of light from the infrared light emitting section to the display section in a plan view, degradation of image quality is reduced.

[0100] The gaze of the user relative to the displayed image is detected from an image of the eyeball obtained by capturing infrared light. Any known method can be used for gaze detection using an image of the eyeball. One example is a gaze detection method based on the Purkinje image formed by reflection of irradiated light on the cornea.

[0101] More specifically, gaze detection processing is performed based on the pupil-corneal reflex method, which calculates a gaze vector representing the direction (rotation angle) of the eyeball based on the pupil image and Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0102] The display device 101 according to this embodiment may have an imaging device having a light receiving element, and may control the display image based on user line of sight information from the imaging device.

[0103] Specifically, the display device 101 determines a first field of view area where the user gazes and a second field of view area other than the first field of view area based on the line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device 101, or may be determined by an external control device and received. In the display area of ​​the display device 101, the display resolution of the first field of view area may be controlled to be higher than the display resolution of the second field of view area. In other words, the resolution of the second field of view area may be lower than that of the first field of view area.

[0104] The display area includes a first display area and a second display area different from the first display area, and a high-priority area is determined from the first display area and the second display area based on line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device 101, or may be determined by an external control device and received. The resolution of the high-priority area may be controlled to be higher than the resolution of areas other than the high-priority area. In other words, the resolution of an area with a relatively low priority may be lowered.

[0105] Note that AI may be used to determine the first field of view area and areas with high priority. The AI ​​may be a model configured to estimate the angle of gaze and the distance to an object in the line of sight from an image of the eyeball, using as training data an image of the eyeball and the direction in which the eyeball in the image was actually looking. The AI ​​program may be included in the display device 101, the imaging device, or an external device. If included in an external device, it is transmitted to the display device 101 via communication.

[0106] When display control is performed based on visual recognition detection, the smart glasses can be preferably applied to smart glasses that further include an imaging device for capturing images of the outside world. The smart glasses can display captured external information in real time.

[0107] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0108] 101: display device, 102: pixel, 201: light emitting element, 205: light receiving element, 501, 620: electrode, 610: substrate, 621: light emitting layer, 651, 652: surface

Claims

1. A display device including a first substrate on which a plurality of pixels are arranged, each of the plurality of pixels includes a light-emitting element disposed on a first surface of the first substrate, and a light-receiving element disposed between the first surface and a second surface of the first substrate opposite to the first surface; further including a second substrate disposed so as to face the second surface; At least a part of a light receiving circuit for driving the light receiving element is disposed on the first substrate, At least a part of a light emitting circuit for driving the light emitting element is disposed on the second substrate, the light-emitting circuit includes a capacitive element disposed between the second surface and the second substrate, and holding a luminance signal corresponding to the luminance at which the light-emitting element emits light; the light-emitting element includes a first electrode, a second electrode disposed between the first surface and the first electrode, and a light-emitting layer disposed between the first electrode and the second electrode; In an orthogonal projection onto the first surface, the second electrode and the light receiving element at least partially overlap, and the light receiving element and the capacitive element at least partially overlap.

2. 2. The display device according to claim 1, wherein the light emitting element and the light receiving element do not overlap in an orthogonal projection onto a third plane perpendicular to the first plane.

3. 3. The display device according to claim 1, wherein the second electrode transmits a part of the light generated in the light-emitting layer.

4. 4. The display device according to claim 3, wherein the transmittance of the second electrode with respect to the light generated in the light-emitting layer is 1% or more and 20% or less.

5. 5. The display device according to claim 1, wherein an opening is provided in the second electrode.

6. 6. The display device according to claim 5, wherein the opening is filled with a part of the light-emitting layer or a light-transmitting member.

7. 6. The display device according to claim 5, wherein the second electrode has a laminated structure of a transparent electrode and a light-shielding film in which the opening is provided.

8. the plurality of pixels include a first pixel and a second pixel that emit light of different colors; 8. The display device according to claim 1, wherein the light receiving sensitivity of the light receiving element arranged in the first pixel and the light receiving sensitivity of the light receiving element arranged in the second pixel are different from each other.

9. 9. The display device according to claim 8, wherein, in an orthogonal projection onto the first surface, the area of ​​the light receiving element arranged in the first pixel and the area of ​​the light receiving element arranged in the second pixel are different from each other.

10. 10. The display device according to claim 1, wherein, in an orthogonal projection onto the first surface, an area occupied by the light receiving element and the light receiving circuit is larger than an area occupied by the light emitting circuit.

11. 11. The display device according to claim 1, wherein a gate insulating film thickness of a transistor in the light receiving circuit arranged on the first substrate and a gate insulating film thickness of a transistor in the light emitting circuit arranged on the second substrate are different from each other.

12. the plurality of pixels include a third pixel and a fourth pixel, 12. The display device according to claim 1, wherein the light receiving element arranged in the third pixel and the light receiving element arranged in the fourth pixel share one light receiving circuit.

13. the plurality of pixels include a third pixel and a fourth pixel, 12. The display device according to claim 1, wherein the third pixel and the fourth pixel share one of the light receiving elements.

14. 14. The display device according to claim 12, wherein the third pixel and the fourth pixel emit light of different colors.

15. an optical unit having a plurality of lenses, an image sensor that receives light that has passed through the optical unit, and a display unit that displays an image; A photoelectric conversion device, wherein the display unit is a display unit that displays an image captured by the image sensor, and the photoelectric conversion device comprises the display device according to any one of claims 1 to 14.

16. A display unit is provided in the housing, and a communication unit is provided in the housing and communicates with an external device.

15. An electronic device, wherein the display unit comprises the display device according to claim 1.

17. A lighting device having a light source and at least one of a light diffusion unit and an optical film, 15. An illumination device, characterized in that the light source comprises a display device according to any one of claims 1 to 14.

18. A moving body having a body and a lighting fixture provided on the body, A moving body, wherein the lighting fixture comprises the display device according to any one of claims 1 to 14.

19. 1. A wearable device having a display device for displaying an image, A wearable device, comprising the display device according to claim 1 .

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