Light-emitting device, display device, imaging device, electronic apparatus, and wearable device

Abstract

To provide a technique capable of suppressing an influence on the display of a light-emitting device caused by the fluctuation of a power supply voltage.SOLUTION: The light-emitting device includes a plurality of pixels each including a light-emitting element and a drive transistor for driving the light-emitting element and power supply wiring for supplying a power supply voltage to the drive transistor. The light-emitting element includes a first electrode, a light-emitting layer arranged on the first electrode, and a second electrode arranged on the light-emitting layer. At least a part of the power supply wiring is arranged at the same height as the bottom surface of the first electrode or at a position closer to the second electrode than the height.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a light-emitting device, a display device, an imaging device, an electronic device, and a wearable device. [Background technology]

[0002] There are display devices equipped with light-emitting devices that use organic EL elements. Patent Document 1 describes an electro-optical device in which a light-emitting element and an intermediate electrode that connects the anode of the light-emitting element and a transistor that controls the current flowing through the light-emitting element are surrounded by power wiring. Patent Document 1 can reduce image quality degradation caused by noise affecting the area from the region where the transistor is formed to the anode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-238723 Summary of the Invention [Problem to be solved by the invention]

[0004] Fluctuations in the power supply voltage in a light-emitting device can cause horizontal stripes to appear on the display. An object of the present invention is to provide a technology that can suppress the influence of fluctuations in the power supply voltage on the display of a light-emitting device. [Means for solving the problem]

[0005] One aspect of the present invention is a light-emitting device comprising a plurality of pixels each comprising a light-emitting element and a drive transistor for driving the light-emitting element, and a power supply wiring for supplying a power supply voltage to the drive transistor, wherein the light-emitting element has a first electrode, a light-emitting layer arranged on the first electrode, and a second electrode arranged on the light-emitting layer, and at least a portion of the power supply wiring is arranged at the same height as the bottom surface of the first electrode or closer to the second electrode than the height. [Effects of the Invention]

[0006] It is possible to provide a technique that can suppress the influence of fluctuations in power supply voltage on the display of a light emitting device. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a block diagram of a light emitting device according to a first embodiment. [Figure 2] FIG. 2 is a circuit diagram of a pixel according to the first embodiment. [Figure 3] 3 is a timing chart according to the first embodiment. [Figure 4] FIG. 10 is a diagram illustrating the occurrence of horizontal stripes. [Figure 5] FIG. 2A is a cross-sectional view of a pixel array section according to the first embodiment, and FIG. 2B is a plan view of the pixel array section according to the first embodiment. [Figure 6] FIG. 10 is a cross-sectional view of a pixel array portion according to a second embodiment. [Figure 7] FIG. 10(a) is a cross-sectional view of a pixel array section according to a third embodiment, and FIG. 10(b) is a plan view of the pixel array section according to the third embodiment. [Figure 8] 1 is a schematic diagram illustrating an example of a display device according to an embodiment of the present invention. [Figure 9] 1A is a schematic diagram showing an example of an imaging device according to an embodiment of the present invention; FIG. 1B is a schematic diagram showing an example of an electronic device according to an embodiment of the present invention; [Figure 10] 1A is a schematic diagram showing an example of a display device according to an embodiment of the present invention, and FIG. 1B is a schematic diagram showing an example of a foldable display device. [Figure 11] FIG. 1A is a schematic diagram showing an example of a wearable device according to one embodiment of the present invention; FIG. 1B is a schematic diagram showing an example of a wearable device according to one embodiment of the present invention, the wearable device having an imaging device. DETAILED DESCRIPTION OF THE INVENTION

[0008] 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.

[0009] (Embodiment 1) The following description will be given taking a light-emitting device using an organic light-emitting element (organic EL) as an example. Fig. 1 is a block diagram of a light-emitting device 101 of this embodiment. The light-emitting device 101 shown in Fig. 1 has a pixel array section 102 and peripheral circuits for the pixel array section 102. The pixel array section 102 has a plurality of pixels 103(1,1) to 103(m,n) arranged two-dimensionally in a matrix with m rows and n columns, and each of the pixels 103(1,1) to 103(m,n) has an organic light-emitting element.

[0010] The peripheral circuits are circuits for controlling the pixels 103(1,1) to 103(m,n) and include a vertical scanning circuit 104, a signal output circuit 105, and a control circuit 106. The signal output circuit 105 has a horizontal scanning circuit 107, a column DAC circuit 108 including a plurality of digital-to-analog conversion (DAC) circuits, and a column driver circuit 109. The column DAC circuit 108 has DAC circuits for n columns, which is the number of columns in the pixel array section 102. The column driver circuit 109 has driver circuits for n columns, which is the number of columns in the pixel array section 102.

[0011] The horizontal scanning circuit 107 scans the column DAC circuits 108 and inputs the digital signals input from the control circuit 106 to the respective DAC circuits of the column DAC circuits 108. The DAC circuits convert the input digital signals into corresponding analog signals. Each driver circuit of the column driver circuit 109 outputs the analog signals input from the corresponding DAC circuits to the corresponding signal lines VL[1 to n].

[0012] The vertical scanning circuit 104 is connected to the pixel array section 102 by reset signal lines Res[1 to m], write control signal lines Sel[1 to m], and light emission control signal lines Sw[1 to m].

[0013] 2 is a circuit diagram of the pixel 103(1,1) in FIG. 1. The pixel 103(1,1) has an organic light-emitting element 111, a drive transistor 112, a write transistor 113, a light-emission control transistor 114, a reset transistor 115, a first capacitance element 116, and a second capacitance element 117. The first capacitance element 116 and the second capacitance element 117 are typically capacitors having an MIM (Metal-Insulator-Metal) structure. The drive transistor 112, the write transistor 113, the light-emission control transistor 114, and the reset transistor 115 are p-channel MOS transistors. Note that all transistors do not need to be p-channel transistors, and an appropriate combination of conductivity type and polarity may be used.

[0014] The organic light-emitting element 111 has an organic layer including an emitting layer between anode and cathode electrodes. In addition to the emitting layer, the organic layer may appropriately include one or more of a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer. The cathode of the organic light-emitting element 111 is provided with a cathode electrode 125 shared by all pixels. The cathode voltage Vcath applied to the cathode electrode 125 is typically −5 V. Parasitic capacitances 118 and 119 are shown. Here, the parasitic capacitance 118 has a capacitance value Cgd and is the parasitic capacitance between the gate electrode and drain electrode of the driving transistor 112. The parasitic capacitance 119 has a capacitance value Cpa and is the parasitic capacitance between the gate electrode of the driving transistor 112 and the cathode electrode 125.

[0015] A power supply wiring 124 is connected to the source electrode of the emission control transistor 114 and one electrode of the second capacitance element 117. One electrode of the first capacitance element 116 and the other electrode of the second capacitance element 117 are connected, and the drain electrode of the emission control transistor 114 and the source electrode of the driving transistor 112 are connected to this connection point. The drain electrode of the driving transistor 112 is connected to the anode electrode of the organic light-emitting element 111. A cathode voltage Vcath is supplied to the cathode electrode of the organic light-emitting element 111. A power supply voltage Vdd is applied to the power supply wiring 124 connected to the second capacitance element. A typical value of the power supply voltage Vdd is 5V. Furthermore, a typical value of the voltage Vm of the drain electrode of the reset transistor 115 is -5V.

[0016] The driving of the light-emitting element of this embodiment will be described using the timing chart of FIG. 3. In FIG. 3, the horizontal axis represents time t. First, at time t1, the write control signal φSel[1] transitions from high to low, causing the gate voltage Vg of the drive transistor 112 to become a correction voltage (hereinafter referred to as Vofs). A typical value of Vofs is 2V. Also at time t1, the reset signal φRes[1] transitions from high to low. At time t2, the light-emitting control signal φSw[1] transitions from low to high, causing the light-emitting control transistor 114 to enter an off state. The period from t1 to t2 is called the reset period. During the reset period, the gate voltage (hereinafter referred to as Vg) of the drive transistor 112 is initialized to Vofs, and the source voltage (hereinafter referred to as Vs) is initialized to the power supply voltage Vdd.

[0017] At time t3, the write control signal φSel[1] transitions from low to high, turning off the write transistor 113. The period from t2 to t3 is called the threshold correction period. During the threshold correction period, the light-emitting control transistor 114 is turned off, so Vs of the drive transistor 112 changes to Vofs-Vth, which is the difference voltage between the voltage Vofs and the threshold voltage (hereinafter referred to as Vth) of the drive transistor 112, and then stabilizes. In other words, the gate-source voltage Vgs (=Vg-Vs) of the drive transistor 112 becomes Vth. The threshold voltage Vth is approximately the gate-source voltage Vgs when current begins to flow through the drive transistor 112. At this time, the gate voltage Vg of the drive transistor 112 is Vofs, so the threshold voltage Vth of the drive transistor 112 is held in the first capacitance element 116.

[0018] At time t4, the signal voltage of the signal line VL[1] switches from voltage Vofs to signal voltage (hereinafter referred to as Vsig). A typical value of Vsig is 3V. At time t5, the write control signal φSel[1] transitions from high to low. This period from t3 to t5 is called the signal write preparation period.

[0019] At time t5, the write transistor 113 is turned on, and the gate voltage Vg of the drive transistor 112 becomes the signal voltage Vsig of the signal line VL[1]. If the capacitance of the first capacitive element 116 is C1 and the capacitance of the second capacitive element 117 is C2, the source voltage Vs of the drive transistor 112 is Vs=Vofs-Vth+C1*(Vsig-Vofs) / (C1+C2) At time t6, the write control signal φSel[1] transitions from low to high. This period from t5 to t6 is called a signal write period.

[0020] At time t7, the light-emission control signal φSw transitions from high to low, turning on the light-emission control transistor 114. At this time, the source voltage Vs of the drive transistor 112 becomes substantially equal to the power supply voltage Vdd. Furthermore, the reset signal φRes[1] transitions from low to high, turning off the reset transistor 115, and current is supplied from the power supply voltage Vdd to the organic light-emitting element 111 via the light-emission control transistor 114 and the drive transistor 112. This causes the organic light-emitting element 111 to emit light. The period from time t7 onwards is called the light-emission period. Meanwhile, the periods t1 to t7 are called non-light-emission periods. The non-light-emission periods alternate row by row. In other words, the non-light-emission periods of the pixels 103(2,1) to 103(2,n) in the second row begin at time t7.

[0021] Next, we will use Figure 4 to explain the horizontal stripes that appear on a display due to fluctuations in the power supply voltage Vdd. The horizontal axis in Figure 4 represents time t. First, we will explain the ideal voltage change (a) in Vg of the drive transistor 112. The power supply voltage Vdd can fluctuate due to noise from outside the light-emitting device 101 or from peripheral circuits (the vertical scanning circuit 104, the signal output circuit 105, and the control circuit 106). Ideally, Vg of the drive transistor 112 also fluctuates at the same amplitude. Because the source voltage Vs of the drive transistor 112 is the power supply voltage Vdd during the light-emitting period, Vgs of the drive transistor 112 remains constant even when the power supply voltage Vdd fluctuates. If Vgs is constant, the source-drain current Ids of the drive transistor will also remain constant. When displaying at 60 fps (frames per second), the light-emitting period is 16 ms and the non-light-emitting period is approximately 0.02 ms, a difference of three orders of magnitude. Therefore, most of the display time is spent in the light-emitting period. If the capacitances of the first capacitance element 116 and the second capacitance element 117 in FIG. 2 are sufficiently large, Vgs of the drive transistor 112 is kept constant during the light emission period even if the power supply voltage Vdd fluctuates.

[0022] However, Vg of the drive transistor 112 may not fluctuate simultaneously with the power supply voltage Vdd and at the same amplitude. This is explained using (b) dark row Ld and (c) bright row Lb in Figure 4. In the dark row Ld, a signal is written at the positive peak of the power supply voltage Vdd fluctuation. Due to the fixed cathode voltage Vcath and the parasitic capacitances 118 and 119 in Figure 2, Vg of the drive transistor 112 has a smaller amplitude than the power supply voltage Vdd fluctuation. Therefore, in the dark row Ld, at the negative peak of the power supply voltage Vdd fluctuation, Vgs of the drive transistor 112 becomes smaller than Vgs during the signal writing period. Because brightness is proportional to the time integral of the source-drain current Ids of the drive transistor, which is determined by Vgs, the time integral of Ids supplied to the light-emitting element 111 in row Ld is smaller than the ideal value shown in (a). This can result in row Ld being a dark row.

[0023] On the other hand, in the bright row Lb, a signal is written at the negative peak of the power supply voltage Vdd fluctuation. Again, due to the fixed cathode voltage Vcath and the parasitic capacitances 118 and 119 in Figure 2, the amplitude of Vg of the drive transistor 112 is smaller than the amplitude of the power supply voltage Vdd fluctuation. Therefore, in row Lb, at the positive peak of the power supply voltage Vdd fluctuation, the Vgs of the drive transistor 112 becomes larger than the Vgs during the signal writing period. Because brightness is proportional to the time integral of the source-drain current Ids of the drive transistor, which is determined by Vgs, row Lb has a larger time integral of Ids supplied to the light-emitting element 111 than the ideal value shown in (a). This makes row Lb brighter than ideal. Thus, the bright and dark rows Ld appear on the screen, potentially resulting in horizontal stripes on the display.

[0024] Because the presence of parasitic capacitances 118 and 119 is unavoidable, in order to prevent horizontal stripes on the display even with the parasitic capacitances 118 and 119, it is preferable that the voltage change of the cathode voltage Vcath also moves simultaneously with the voltage change of the power supply voltage Vdd and with the same amplitude. To achieve this, it is necessary to strengthen the capacitive coupling between the power supply wiring 124 to which the power supply voltage Vdd is applied in the pixel array unit 102 and the cathode electrode 125.

[0025] FIG. 5 shows FIG. 5(a) showing a cross section of the pixel array unit 102 of this embodiment, and FIG. 5(b) showing a plan view. FIG. 5(b) is a cross-sectional view taken along line AA' in FIG. 5(a). FIG. 5(a) is a cross-sectional view taken along line BB' in FIG. 5(b). The pixel array unit may include a green color filter 131, a red color filter 132, a bank 134 between anode electrodes, an organic layer 135, and an anode electrode 136. Note that components with the same reference numerals as in previous figures represent the same components. An organic layer 135 including an emitting layer is disposed on the anode electrode 136. A cathode electrode 125, which is a common electrode for multiple pixels, is disposed on the organic layer 135.

[0026] As shown in FIG. 5( a), a portion of the power supply wiring 124 is disposed at the same height as the layer containing the anode electrode 136, or at a position at or above the bottom surface of the anode electrode 136 (the opposite side of the anode electrode from where the cathode electrode is disposed). In this case, it is preferable to cover a portion of the power supply wiring 124 with a bank 134, which is an insulating region that forms an insulating portion. This electrically insulates a portion of the electrical wiring 124. Because the power supply wiring 124 and the anode electrode 136 are located on the same layer, they can be fabricated simultaneously using a photolithography process. Furthermore, the power supply wiring 124 and the anode electrode 136 are made of the same material, such as aluminum. Copper may also be used. Furthermore, as shown in FIG. 5( b), the power supply wiring 124 is disposed so as to weave between adjacent anode electrodes 136. This arrangement generates strong capacitive coupling between the power supply wiring 124 and the cathode electrode 125 in the pixel array section 102. As a result, horizontal stripes due to fluctuations in the power supply voltage Vdd can be reduced. In this embodiment, the anode electrode 136 is hexagonal in shape to efficiently utilize the area.

[0027] Note that a method of providing a bypass capacitor outside the light-emitting device 101 is also possible for generating capacitive coupling between the power supply wiring 124 and the cathode electrode 125. However, providing a bypass capacitor outside the light-emitting device increases the inductance component from the power supply wiring 124 in the pixel array unit 102 to the cathode electrode 125, making it impossible to ensure that fluctuations in the cathode voltage Vcath coincide with fluctuations in the power supply voltage Vdd. Therefore, it is better to achieve capacitive coupling within the pixel array unit 102.

[0028] Furthermore, the voltage of the power supply wiring 124 is higher than that of the anode electrodes 136. By providing the power supply wiring 124 between the anode electrodes 136, it is possible to prevent holes from drifting from the anode electrode 136 side to the power supply wiring 124 side via the hole transport layer, which also has the effect of reducing crosstalk between pixels.

[0029] In this embodiment, the anode electrode 136 has a hexagonal shape, but it may have a rectangular shape or another shape. Also, although the column DAC circuit 108 and the column driver circuit 109 have been described as having DAC circuits and driver circuits for n columns, which is the number of columns in the pixel array unit 102, it is possible to have fewer than n columns by using a switch.

[0030] (Embodiment 2) FIG. 6 is a cross-sectional view of the pixel array unit 102 of the second embodiment. Components denoted by the same reference numerals as in the previous figures represent the same components. The plan view of the cross-sectional view of FIG. 6 taken along line AA′ may have a shape similar to that of FIG. 5( b) described in the first embodiment. In this embodiment, as shown in FIG. 6, the power supply wiring 124 may be disposed in an upper layer above the anode electrode 136, and the power supply wiring 124 may be covered with a bank 134, which is an insulating region that forms an insulating portion. This electrically insulates a portion of the electrical wiring 124. In the second embodiment, the power supply wiring 124 and the anode electrode 136 may be fabricated using separate photolithography processes. In the second embodiment, stronger capacitive coupling can be generated between the power supply wiring 124 and the cathode electrode 125 than in the first embodiment, thereby reducing horizontal pixel stripes. Furthermore, crosstalk between pixels can be reduced, as in the first embodiment.

[0031] (Embodiment 3) FIG. 7(a) shows a cross section of the pixel array unit 102 of the third embodiment, and FIG. 7(b) shows a plan view. FIG. 7(b) is a cross-sectional view taken along line AA' in FIG. 7(a). FIG. 7(a) is a cross-sectional view taken along line BB' in FIG. 7(b). In the figure, an opening 139 is provided in the anode electrode 136. Components with the same reference numerals as those in the previous figures represent the same components. As shown in the cross-sectional view of FIG. 7(a), the power supply wiring 124 is disposed below the opening 139 provided in the anode electrode 136. As a result, strong capacitive coupling occurs between the power supply wiring 124 and the opposing cathode electrode 125 through the opening 139. This reduces horizontal stripes caused by fluctuations in the power supply voltage Vdd. The opening 139 should preferably be circular, as shown in the plan view of FIG. 7(b), so that many electric field lines can run from the power supply wiring 124 to the cathode electrode 125 within the smallest possible area. Multiple openings 139 may also be provided. On the other hand, the cathode electrode 125 may have a mesh structure, and the gaps in the mesh may serve as openings.

[0032] (Example of application of light emitting device) Examples of applications of the light-emitting devices according to the first to third embodiments to devices will be described below. FIG. 8 is a schematic diagram showing an example of a display device that can use the light-emitting devices according to the first to third embodiments. A display device 1000 may have 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. Flexible printed circuits FPCs 1002 and 1004 can be connected to the touch panel 1003 and the display panel 1005. A transistor is disposed on the circuit board 1007. The battery 1008 may not be provided if the display device is not a portable device, and may be provided in a different position even if the display device is a portable device.

[0033] The display device according to this embodiment may have color filters having red, green, and blue colors, which may be arranged in a delta arrangement.

[0034] The display device according to the present embodiment may be used as a display unit of a mobile terminal. In this case, the display device may have both a display function and an operation function. Examples of the mobile terminal include a mobile phone such as a smartphone, a tablet, and a head-mounted display.

[0035] The display device according to this embodiment may be used as a display unit of an imaging device having an optical unit with a plurality of lenses and an imaging element that receives light that has passed through the optical unit. The imaging device may have a display unit that displays information acquired by the imaging element. The display unit may be a display unit exposed to the outside of the imaging device or a display unit disposed within a viewfinder. The imaging device may be a digital camera or a digital video camera.

[0036] 9(a) is a schematic diagram showing an example of an imaging device using the light-emitting device according to any one of the first to third embodiments as a display device. The imaging device 1100 may include a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 may include the display device according to this embodiment. In this case, the display device may display not only the 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 speed at which the subject is moving, the possibility that the subject will be blocked by an obstruction, and the like.

[0037] Since the timing suitable for capturing an image is short, it is better to display information as soon as possible. Therefore, it is advisable to use a light-emitting device using an organic light-emitting element in a display device. This is because organic light-emitting elements have a fast response speed. Display devices using organic light-emitting elements are suitable for use in such devices where a high display speed is required.

[0038] The imaging device 1100 has an optical section (not shown). The optical section has multiple lenses, which form an image on an imaging element housed in a housing 1104. The focus of the multiple lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically. The imaging device may also be called a photoelectric conversion device. Instead of sequentially capturing images, the photoelectric conversion device can include an imaging method that detects the difference from the previous image, or a method of cutting out an image from a constantly recorded image, etc.

[0039] FIG. 9(b) is a schematic diagram illustrating an example of an electronic device using the light-emitting device according to any one of the first to third embodiments. 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 may be a biometric recognition unit that recognizes a fingerprint to unlock the device, etc. An electronic device having a communication unit can also be called a communication device. The electronic device may further have a camera function by including a lens and an image sensor. An image captured by the camera function is displayed on the display unit. Examples of the electronic device include a smartphone and a laptop computer.

[0040] 10(a) and 10(b) are schematic diagrams showing an example of a display device using the light-emitting device according to embodiments 1 to 3. Fig. 10(a) shows 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 light-emitting device according to this embodiment may be used in the display unit 1302.

[0041] It has a frame 1301 and a base 1303 that supports a display unit 1302. The base 1303 is not limited to the form shown in Fig. 10(a). The bottom side of the frame 1301 may also serve as the base.

[0042] 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.

[0043] FIG. 10(b) is a schematic diagram illustrating another example of a display device according to this embodiment. The display device 1310 in FIG. 10(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 first display unit 1311 and the second display unit 1312 may include a light-emitting device according to this embodiment. The first display unit 1311 and the second display unit 1312 may be a single, seamless display unit. 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 and second display units may display a single image.

[0044] 11(a) and 11(b), an application example of a display device according to the embodiment using the light-emitting device of the above-described embodiment will be described. The display device can be applied to a system that can be worn as a wearable device, such as smart glasses, an HMD, or a smart contact lens. The image capturing and display device used in such an application example includes an image capturing device capable of photoelectrically converting visible light and a display device capable of emitting visible light.

[0045] 11(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, a display device according to any of the above-described embodiments is provided on the back side of the lens 1601.

[0046] 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 according to each embodiment. The control device 1603 also controls the operations of the image capture device 1602 and the display device. The lens 1601 is formed with an optical system for focusing light onto the image capture device 1602.

[0047] FIG. 11(b) illustrates glasses 1610 (smart glasses) according to one application example. The glasses 1610 include a control device 1612. The control device 1612 is equipped with an imaging device equivalent to the imaging device 1602 and a display device. A lens 1611 is formed with an optical system for projecting light emitted by the display device in the control device 1612, 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 and controls the operation of the imaging device and the display device. The control device may include a gaze detection unit for detecting the gaze of the wearer. Infrared light may be used for gaze detection. The infrared light emitting unit emits infrared light toward the eyeball of a user gazing at a displayed image. An imaging unit with a light receiving element detects the reflected light of the emitted infrared light from the eyeball, thereby obtaining an image of the eyeball. A reduction unit for reducing light from the infrared light emitting unit to the display unit in a planar view reduces degradation of image quality.

[0048] 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.

[0049] 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.

[0050] The display device according to this embodiment may have an imaging device having a light receiving element, and may control the image displayed on the display device based on information about the user's line of sight from the imaging device.

[0051] Specifically, the display device determines a first display area where the user gazes and a second display area other than the first display area based on the line-of-sight information. The first display area and the second display area may be determined by a control device of the display device, or may be determined by an external control device and received. In the display area of the display device, the display resolution of the first display area may be controlled to be higher than the display resolution of the second display area. In other words, the resolution of the second display area may be lower than that of the first field of view area.

[0052] 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 and second view areas may be determined by a control device of the display device, 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.

[0053] Note that AI (Artificial Intelligence) may be used to determine the first display area and the area 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 the 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, the imaging device, or an external device. If included in the external device, it is transmitted to the display device via communication.

[0054] 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.

[0055] As described above, by using a device using the organic light-emitting element according to this embodiment, it is possible to provide a stable display with good image quality even over a long period of time.

[0056] (Other embodiments) (Item 1) a plurality of pixels each including a light-emitting element and a driving transistor for driving the light-emitting element; a power supply wiring for supplying a power supply voltage to the driving transistor, The light-emitting element has a first electrode, a light-emitting layer arranged on the first electrode, and a second electrode arranged on the light-emitting layer, and at least a portion of the power supply wiring is arranged at the same height as the bottom surface of the first electrode or at a position closer to the second electrode than the height. (Item 2) 2. The light emitting device according to item 1, wherein at least a portion of the power supply wiring is arranged to surround the first electrode. (Item 3) 3. The light-emitting device according to item 1 or 2, wherein at least a portion of the power supply wiring is disposed between the first electrodes of the adjacent pixels. (Item 4) 4. The light emitting device according to any one of items 1 to 3, wherein at least a part of the power supply wiring is electrically insulated from the second electrode by an insulating portion. (Item 5) 5. The light emitting device according to any one of items 1 to 4, wherein the driving transistor is connected to the first electrode. (Item 6) 6. The light emitting device according to any one of items 1 to 5, wherein the first electrode is an anode electrode and the second electrode is a cathode electrode. (Item 7) a plurality of pixels each including a light-emitting element and a driving transistor for driving the light-emitting element; a power supply wiring for supplying a power supply voltage to the driving transistor, the light-emitting element has a first electrode, a light-emitting layer disposed on the first electrode, and a second electrode disposed on the light-emitting layer; The light emitting device, wherein the first electrode has an opening, and at least a part of the power supply wiring is disposed so as to face the second electrode via the opening. (Item 8) 8. The light emitting device according to item 7, wherein a plurality of the openings are provided in the first electrode. (Item 9) Item 9. The light-emitting device according to item 7 or 8, wherein the opening has a circular shape. (Item 10) 10. The light emitting device according to any one of items 7 to 9, wherein the first electrode has a hexagonal shape. (Item 11) 11. The light emitting device according to any one of items 7 to 10, wherein at least a part of the power supply wiring is insulated from the second electrode by an insulating portion. (Item 12) 12. The light emitting device according to any one of items 7 to 11, wherein the driving transistor is connected to the first electrode. (Item 13) 13. The light emitting device according to any one of items 7 to 12, wherein the first electrode is an anode electrode and the second electrode is a cathode electrode. (Item 14) 14. An imaging device comprising: an optical unit having a plurality of lenses; an imaging element that receives light that has passed through the optical unit; and a display unit that displays an image captured by the imaging element, wherein the display unit comprises a light-emitting device according to any one of items 1 to 13. (Item 15) 14. A display device comprising: a display unit having the light-emitting device according to any one of items 1 to 13; and a housing in which the display unit is provided. (Item 16) 14. An electronic device comprising: a display unit having the light-emitting device according to any one of items 1 to 13; a housing in which the display unit is provided; and a communication unit provided in the housing and configured to communicate with an external device. (Item 17) A wearable device having a display device for displaying an image, 14. A wearable device, wherein the display device comprises the light-emitting device according to any one of items 1 to 13.

[0057] 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]

[0058] 124: power supply wiring, 125: cathode electrode, 131: green color filter, 132: red color filter, 135: organic layer, 136: anode electrode

Claims

1. a plurality of pixels each including a light-emitting element and a driving transistor for driving the light-emitting element; a power supply wiring for supplying a power supply voltage to the driving transistor, the light-emitting element has a first electrode, a light-emitting layer arranged on the first electrode, and a second electrode arranged on the light-emitting layer, and at least a portion of the power supply wiring is arranged at the same height as a bottom surface of the first electrode or at a position closer to the second electrode than the height.

2. The light emitting device according to claim 1 , wherein at least a portion of the power supply wiring is disposed so as to surround the first electrode.

3. 2. The light emitting device according to claim 1, wherein at least a portion of the power supply wiring is disposed between the first electrodes of the adjacent pixels.

4. 2. The light emitting device according to claim 1, wherein at least a part of the power supply wiring is electrically insulated from the second electrode by an insulating portion.

5. 2. The light emitting device according to claim 1, wherein the driving transistor is connected to the first electrode.

6. 2. The light emitting device according to claim 1, wherein the first electrode is an anode electrode and the second electrode is a cathode electrode.

7. a plurality of pixels each including a light-emitting element and a driving transistor for driving the light-emitting element; a power supply wiring for supplying a power supply voltage to the driving transistor, the light-emitting element has a first electrode, a light-emitting layer disposed on the first electrode, and a second electrode disposed on the light-emitting layer; The light emitting device, wherein the first electrode has an opening, and at least a part of the power supply wiring is disposed so as to face the second electrode via the opening.

8. The light emitting device according to claim 7 , wherein the first electrode has a plurality of openings.

9. The light emitting device according to claim 7 , wherein the opening has a circular shape.

10. The light emitting device according to claim 7 , wherein the first electrode has a hexagonal shape.

11. 8. The light emitting device according to claim 7, wherein at least a part of the power supply wiring is insulated from the second electrode by an insulating portion.

12. 8. The light emitting device according to claim 7, wherein the driving transistor is connected to the first electrode.

13. 8. The light emitting device according to claim 7, wherein the first electrode is an anode electrode and the second electrode is a cathode electrode.

14. 14. An imaging device comprising: an optical section having a plurality of lenses; an imaging element that receives light that has passed through the optical section; and a display section that displays an image captured by the imaging element, wherein the display section comprises a light-emitting device according to any one of claims 1 to 13.

15. A display device comprising: a display portion having the light-emitting device according to claim 1; and a housing in which the display portion is provided.

16. 14. An electronic device comprising: a display unit having the light-emitting device according to claim 1; a housing in which the display unit is provided; and a communication unit provided in the housing for communicating with an external device.

17. A wearable device having a display device for displaying an image, A wearable device, wherein the display device comprises the light-emitting device according to claim 1 .

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