Light-emitting device, display device, photoelectric conversion device, electronic apparatus, luminaire, and movable body

Abstract

To provide a technique advantageous for improving display quality.SOLUTION: A light-emitting device includes pixels each including a light-emitting element, a first transistor supplying current to the light-emitting element according to a brightness signal, and a second transistor supplying the brightness signal to a gate electrode of the first transistor. A diffusion region serving as a source region and a drain region of the second transistor is first conductivity type while a gate electrode of the second transistor is second conductivity type opposite to the first conductivity type.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Light-emitting devices using self-luminous elements such as organic electroluminescence (EL) elements are known. Patent Document 1 shows a display device having pixels each including a drive transistor that supplies a current to a light-emitting element according to a luminance signal, and a write transistor that supplies the luminance signal to the drive transistor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-064265 Summary of the Invention [Problem to be solved by the invention]

[0004] If the luminance signal supplied to the drive transistor changes due to the off-leak current of the write transistor, the luminance of the light emitting element changes, resulting in a deterioration in the image quality of the light emitting device. To improve display quality, it is necessary to suppress the off-leak current of the write transistor.

[0005] An object of the present invention is to provide a technique that is advantageous for improving display quality. [Means for solving the problem]

[0006] In view of the above problems, a light-emitting device according to an embodiment of the present invention is a light-emitting device in which a pixel is arranged, the pixel including a light-emitting element, a first transistor that supplies a current to the light-emitting element according to a luminance signal, and a second transistor that supplies the luminance signal to a gate electrode of the first transistor, wherein a diffusion region that functions as a source region and a drain region of the second transistor is of a first conductivity type, and a gate electrode of the second transistor is of a second conductivity type opposite to the first conductivity type. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a technique that is advantageous for improving display quality. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing a configuration example of a light emitting device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a diagram showing a configuration example of a pixel of the light-emitting device in FIG. [Figure 3] FIG. 2 is a plan view showing an example of the configuration of a pixel of the light-emitting device of FIG. [Figure 4] 2 is a cross-sectional view showing a configuration example of a pixel of the light-emitting device of FIG. [Figure 5] 1 is a diagram showing a configuration example of a light emitting device according to an embodiment of the present invention; [Figure 6] 6A and 6B are diagrams showing examples of the configuration of pixels in the light-emitting device of FIG. 5; [Figure 7] 6 is a plan view showing an example of the configuration of a pixel of the light emitting device of FIG. 5. [Figure 8] 6 is a cross-sectional view showing a configuration example of a pixel of the light-emitting device of FIG. 5. [Figure 9] 1 is a diagram showing a configuration example of a light emitting device according to an embodiment of the present invention; [Figure 10] 10A and 10B are diagrams showing examples of the configuration of pixels in the light-emitting device of FIG. [Figure 11] 10 is a plan view showing an example of the configuration of a pixel of the light emitting device of FIG. [Figure 12] 10 is a cross-sectional view showing a configuration example of a pixel of the light-emitting device of FIG. [Figure 13] 1A and 1B are diagrams illustrating an example of a display device using the light-emitting device of this embodiment. [Figure 14] FIG. 1 is a diagram showing an example of a photoelectric conversion device using the light emitting device of this embodiment. [Figure 15] 1A to 1C are diagrams illustrating examples of electronic devices using the light-emitting device of this embodiment. [Figure 16] 1A and 1B are diagrams illustrating an example of a display device using the light-emitting device of this embodiment. [Figure 17] 1 is a diagram showing an example of a lighting device using the light-emitting device of this embodiment. [Figure 18] 1A and 1B are diagrams showing an example of a moving object using the light emitting device of the present embodiment. [Figure 19] FIG. 1 is a diagram showing an example of a wearable device using the light-emitting 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 light emitting device according to an embodiment of the present disclosure will be described with reference to Figures 1 to 12. Figure 1 is a schematic diagram showing an example of the configuration of a light emitting device 101 according to this embodiment. Figure 2 is a circuit diagram showing an example of the configuration of a pixel 102 arranged in the light emitting device 101.

[0011] In the following description, a case will be described in which a driving transistor 202 is connected to the anode of a light-emitting element 201 arranged in each pixel 102 of the light-emitting device 101, and all transistors arranged in the pixel 102 are P-type transistors. However, the configuration of the pixels 102 of the light-emitting device 101 is not limited to this. For example, the polarity and conductivity type of each transistor may all be reversed. Also, for example, the driving transistor may be a P-type transistor and the other transistors may be N-type transistors. The supplied potential and connection may be changed appropriately in accordance with the conductivity type and polarity of the light-emitting element and transistors included in the pixels 102 of the light-emitting device 101.

[0012] In this embodiment, as shown in FIG. 1 , a light-emitting 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 in an array. Each pixel 102 includes a light-emitting element 201. The light-emitting element 201 includes, for example, an anode and a cathode, and an organic layer including a light-emitting layer between the anode and the 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. In other words, the light-emitting element 201 may be an organic EL (organic electroluminescent) element.

[0013] The drive circuit is a circuit for driving the pixels 102 arranged in the pixel array 103. The drive circuit includes, for example, a vertical scanning circuit 104 and a signal output circuit 105. In order to supply signals from the drive circuit to the pixels 102, the pixel array 103 is provided with scanning lines 106 extending along the row direction (the horizontal direction in FIG. 1) and arranged for each row of the pixels 102 arranged in the array. The pixel array 103 is also provided with signal lines 107 extending along the column direction (the vertical direction in FIG. 1) and arranged for each column of the pixels 102 arranged in the array.

[0014] The scanning lines 106 are connected to output terminals of the vertical scanning circuit 104 for the respective pixel rows. The signal lines 107 are connected to output terminals of the signal output circuit 105 for the respective pixel columns.

[0015] The vertical scanning circuit 104 supplies a write control signal to the scanning line 106 when writing a video signal to each pixel 102 in the pixel array 103 .

[0016] The signal output circuit 105 appropriately selects either a luminance signal having a voltage corresponding to luminance information when causing the light emitting element 201 of each pixel 102 to emit light, or a reference voltage signal having a reference voltage, and outputs the selected signal to a signal line 107. The luminance signal represents the luminance of each pixel 102 of an image displayed by the light emitting device 101, and may also be called a video signal.

[0017] 2 includes a light-emitting element 201, a drive transistor 202 that supplies a current corresponding to a luminance signal to the light-emitting element 201, and a write transistor 203 that supplies the luminance signal to the gate electrode of the drive transistor. Here, the total number of transistors and the combination of the conductivity types of the transistors are merely examples and are not limited to this configuration.

[0018] In this embodiment, one end of a current path including the light-emitting element 201 and the driving transistor 202 is connected to the power supply potential Vss, and the other end is connected to the power supply potential Vdd. More specifically, the cathode of the light-emitting element 201 is connected to the power supply potential Vss, and one of the diffusion regions functioning as the source region and drain region of the driving transistor 202 (the source region in the configuration of FIG. 2) is connected to the power supply potential Vdd. However, this is not limited thereto, and other elements may be arranged between the power supply potential Vss and the light-emitting element 201 or between the power supply potential Vdd and the driving transistor 202. Furthermore, other elements may be arranged between the light-emitting element 201 and the driving transistor 202. In the configuration shown in FIG. 2, the power supply potential Vdd is higher than the power supply potential Vss.

[0019] The other of the diffusion regions functioning as the source region and drain region of the driving transistor 202 (the drain region in the configuration of FIG. 2) is connected to the anode of the light emitting element 201. The gate electrode of the driving transistor 202 is connected to the diffusion region functioning as the source region and drain region of the writing transistor 203 (the drain region in the configuration of FIG. 2).

[0020] The write transistor 203 is disposed between the signal line 107 and the gate electrode of the drive transistor 202. More specifically, one of the diffusion regions functioning as the source region and drain region of the write transistor 203 is connected to the gate electrode of the drive transistor 202 as described above, and the other of the diffusion regions functioning as the source region and drain region of the write transistor 203 is connected to the signal line 107. The gate electrode of the write transistor 203 is connected to the scanning line 106.

[0021] The driving transistor 202 supplies a current from the power supply potential Vdd to the light emitting element 201, causing the light emitting element 201 to emit light. More specifically, the driving transistor 202 supplies a current according to the signal voltage of the signal line 107 to the light emitting element 201. As a result, the driving transistor 202 current-drives the light emitting element 201, causing it to emit light.

[0022] The write transistor 203 is rendered conductive in response to a write control signal applied to its gate electrode from the vertical scanning circuit 104 through the scanning line 106. This causes the write transistor 203 to sample a signal voltage or a reference voltage of a luminance signal corresponding to luminance information supplied from the signal output circuit 105 via a signal line 107, and write the signal voltage or reference voltage to the pixel 102. This written signal voltage or reference voltage is applied to the gate electrode of the drive transistor 202. In other words, the write transistor 203 is arranged to transmit a luminance signal that causes the light-emitting element 201 to emit light at a luminance corresponding to the luminance information, and transmits the luminance signal to the gate electrode of the drive transistor 202.

[0023] An organic EL element can be used for the light-emitting element 201. When the light-emitting element 201 emits light, the amount of current flowing through the driving transistor 202 changes depending on the signal voltage applied to the gate electrode of the driving transistor 202 from the signal line 107 via the writing transistor 203. This charges the capacitance between the anode and cathode of the light-emitting element 201 to a predetermined potential, and a current corresponding to this potential difference flows. This causes the light-emitting element 201 to emit light at a predetermined brightness.

[0024] 3 and 4, the drive transistor 202 and the write transistor 203 included in the pixel 102 will be described in detail. Fig. 3 is a plan view showing an outline of the pixel 102, and Fig. 4 is a cross-sectional view taken along line Y1-Y1' shown in Fig. 3.

[0025] The driving transistor 202 includes two P-type diffusion regions 302 and 303 that function as a source region and a drain region, respectively, arranged in a current path including the light-emitting element 201. The driving transistor 202 also includes a gate electrode 301. As described above, a luminance signal is transmitted from the writing transistor 203 to the gate electrode 301.

[0026] In this embodiment, the conductivity type of the gate electrode 301 of the driving transistor 202, which is a P-type transistor, is N-type, which is the opposite conductivity type to the P-type diffusion regions 302 and 303. By making the gate electrode 301 N-type relative to the P-type diffusion regions 302 and 303, it is possible to increase the threshold voltage of the work function difference and suppress the off-leak current in the driving transistor 202. By suppressing the off-leak current in the driving transistor 202, a deeper black display is achieved and high contrast can be obtained.

[0027] The write transistor 203 includes a gate electrode 304 and P-type diffusion regions 305 and 306, which function as a source region and a drain region, respectively. The diffusion region 306 is connected to a gate electrode 301 of the drive transistor 202. The diffusion region 305 is connected to a signal line 107, and the gate electrode 304 is connected to a scanning line 106.

[0028] In this embodiment, the conductivity type of the gate electrode 304 of the write transistor 203, which is a P-type transistor, is N-type, which is the opposite conductivity type to the P-type diffusion regions 305 and 306. By making the gate electrode 304 N-type relative to the P-type diffusion regions 305 and 306, the threshold voltage of the work function difference is increased, making it possible to suppress off-leak current in the write transistor 203. By suppressing the off-leak current in the write transistor 203, it becomes possible to keep the signal voltage of the luminance signal written to the gate electrode 301 of the drive transistor 202 more constant during the light emission period. As a result, it is possible to suppress changes in the luminance of the light emitting element 201, and to achieve high-quality display.

[0029] In this embodiment, the drive transistor 202 and the write transistor 203 are each disposed in an N-type well 403 provided in a P-type substrate 405. A well contact 307 applies a power supply potential Vdd to the N-type well 403. The element isolation portion 404 may be any appropriate structure, such as STI (Shallow Trench Isolation), LOCOS (Local Oxidation Of Silicon), or N-type diffusion layer isolation.

[0030] The inventors of the present invention have furthered their research into the light-emitting device 101 configured as described above and have found the following problem. In the process of forming the channel region of the write transistor 203, a characteristic distribution occurs in the channel concentration and threshold voltage of the write transistor 203, corresponding to the distribution of the amount of implanted impurity ions. As a result, the off-leak current of the write transistor 203 is unstable, and the signal voltage of the gate electrode 301 of the drive transistor 202 during the light-emitting period varies for each pixel 102, causing the amount of current supplied to the light-emitting element 201 to vary, resulting in display unevenness.

[0031] To address this issue, the channel region 402 of the write transistor 203 may be either a P-type or N-type diffusion layer, but it is effective to keep the impurity concentration as low as possible. This reduces variations in the channel concentration, threshold voltage, and off-leakage current of the write transistor 203, and suppresses changes in the signal voltage of the gate electrode 301 of the drive transistor 202 for each pixel 102 during the light emission period. This reduces variations in the amount of current supplied to the light-emitting element 201. In other words, the closer the impurity concentration of the channel region 402 of the write transistor 203 is to "0," the more likely it is that variations in the amount of current supplied to the light-emitting element will be suppressed.

[0032] For example, the impurity concentration of the channel region 402 of the write transistor 203 may be lower than the impurity concentration of the well 403. Furthermore, for example, the impurity concentration of the channel region 402 of the write transistor 203 may be substantially the same as the impurity concentration of the channel region 401 of the drive transistor 202. Similarly, for example, the impurity concentration of the channel region 402 of the write transistor 203 may be substantially the same as the impurity concentration of the channel region of a transistor in a drive circuit (e.g., the vertical scanning circuit 104 or the signal output circuit 105) arranged around the pixel array 103. This eliminates the need to increase the number of processes for forming the channel regions of the write transistor 203, the drive transistor 202, and the transistors in the drive circuit arranged around the pixel array 103. In this specification, the impurity concentration may refer to a concentration based on the number of carriers, which is determined by the difference between the number of holes and electrons in each region functioning as a P-type or N-type.

[0033] 4, the channel region 402 of the write transistor 203 may be a P-type buried channel. By making the channel region 402 a P-type buried channel, it is possible to suppress current fluctuations caused by RTS (Random Telegraph Signal) noise of the write transistor 203. Even in this case, the impurity concentration of the channel region 402 of the write transistor 203 may be lower than the impurity concentration of the well 403. Furthermore, for example, the impurity concentration of the channel region 402 of the write transistor 203 may be approximately the same as the impurity concentration of the channel region 401 of the drive transistor 202 and the impurity concentration of the channel region of a transistor in a circuit of a drive unit arranged in the periphery of the pixel array 103.

[0034] 4, the channel region 401 of the driving transistor 202 may be a P-type buried channel. By making the channel region 401 a P-type buried channel, current fluctuations caused by RTS (Random Telegraph Signal) noise of the driving transistor 202 can be suppressed.

[0035] As described above, by using an N-type gate electrode 304 in the write transistor 203, which is a P-type transistor, the off-leak current of the write transistor 203 is suppressed. This makes it possible to keep the signal voltage of the luminance signal written to the gate electrode 301 of the drive transistor 202 more constant during the light emission period. As a result, the change in luminance of the light emitting element 201 is suppressed, and the light emitting device 101 can display high quality images.

[0036] Furthermore, by lowering the impurity concentration of the channel region 402 of the write transistor 203, variations in the channel concentration, threshold voltage, and off-leak current of the write transistor 203 are suppressed. This suppresses variations in the signal voltage of the gate electrode 301 of the drive transistor 202 for each pixel 102 during the light emission period, thereby suppressing display unevenness in the light emitting device 101. As a result, the light emitting device 101 can achieve high-quality display.

[0037] Next, with reference to Fig. 5 to Fig. 8, a modified example of the light emitting device 101 described above with reference to Fig. 1 to Fig. 4 will be described. Fig. 5 is a schematic diagram showing an example of the configuration of a light emitting device 121 in this embodiment. Fig. 6 is a circuit diagram showing an example of the configuration of a pixel 122 arranged in the light emitting device 121.

[0038] In this embodiment, the pixel 122 of the light emitting device 121 further includes a light emission control transistor 221 that is arranged in a current path including the light emitting element 201 and the drive transistor 202 and controls whether the light emitting element 201 emits light or not, as compared to the pixel 102 of the light emitting device 101 described above. Furthermore, the pixel array 103 of the light emitting device 121 includes a scanning line 123 for switching the conduction / non-conduction of the light emitting control transistor 221, in addition to the configuration of the pixel array 103 of the light emitting device 101. Furthermore, the pixel 122 further includes capacitance elements 222 and 223. The remaining configuration of the light emitting device 121 may be the same as that of the light emitting device 101 described above. The following description will focus on the configuration of the light emitting device 121 of this embodiment that is different from that of the light emitting device 101 described above.

[0039] 5, in the pixel array 103, scanning lines 123 extending along the row direction are arranged for each pixel row of the arrayed pixels 122. The scanning lines 123 are connected to output terminals of the vertical scanning circuit 104 corresponding to the pixel rows, and supply light emission control signals to each pixel 122.

[0040] As shown in FIG. 6, the light-emitting control transistor 221 is arranged between the driving transistor 202 and a power supply potential Vdd for supplying a driving current to the driving transistor 202. More specifically, one of the diffusion regions functioning as the source region and drain region of the light-emitting control transistor 221 (the source region in the configuration of FIG. 6) is connected to the power supply potential Vdd. The other of the diffusion regions functioning as the source region and drain region of the light-emitting control transistor 221 (the drain region in the configuration of FIG. 6) is connected to one of the diffusion regions functioning as the source region and drain region of the driving transistor 202 (the source region in the configuration of FIG. 6). The gate electrode of the light-emitting control transistor 221 is connected to the scanning line 123. However, the present invention is not limited to this, and the light-emitting control transistor 221 may be arranged, for example, between the driving transistor 202 and the light-emitting element 201.

[0041] The capacitance element 222 is connected between the gate electrode of the driving transistor 202 and one of the diffusion regions functioning as the source region and drain region of the driving transistor 202 (the source region in the configuration of FIG. 6). The capacitance element 223 is connected between one of the diffusion regions functioning as the source region and drain region of the driving transistor 202 (the source region in the configuration of FIG. 6) and the power supply potential Vdd. The capacitance elements 222 and 223 may be parasitic capacitances of the driving transistor 202 and the light-emitting control transistor 221. The capacitance elements 222 and 223 may also be elements having an MIM (Metal-Insulator-Metal) structure.

[0042] The light-emission control transistor 221 becomes conductive in response to a light-emission control signal applied to its control terminal from the vertical scanning circuit 104 via the scanning line 123, thereby allowing current to be supplied from the power supply potential Vdd to the drive transistor 202. This enables the drive transistor 202 to drive the light-emitting element 201. In other words, the light-emission control transistor 221 functions as a switch element that controls the light-emission / non-light-emission of the light-emitting element 201 by controlling the conductive state of the current path in which the light-emitting element 201 is arranged.

[0043] The switching operation of the light-emission control transistor 221 provides a period during which the light-emitting element 201 is in a non-light-emitting state (non-light-emitting period), and the ratio of the light-emitting period during which the light-emitting element 201 emits light to the non-light-emitting period can be controlled (so-called duty control). This duty control reduces afterimage blurring that occurs when the light-emitting element 201 of each pixel 122 emits light over one frame period, thereby improving the quality of moving images in particular. Furthermore, by providing two capacitance elements 222 and 223, the signal voltage of the gate electrode 301 of the drive transistor 202 can be kept more constant, thereby suppressing luminance changes and enabling high-quality display. This embodiment does not impair the effects of suppressing the off-leak current of the write transistor 203 and suppressing variations in the write transistor 203, and high-quality display is maintained.

[0044] Next, the light-emission control transistor 221 will be described in detail with reference to Fig. 7 and Fig. 8. Fig. 7 is a plan view showing an outline of the pixel 122, and Fig. 8 is a cross-sectional view taken along line Y2-Y2' shown in Fig. 7.

[0045] 7 and 8, the light-emitting control transistor 221 is composed of an N-type gate electrode 321, a P-type diffusion region 302 that functions as a source region or a drain region, respectively, arranged in a current path including the light-emitting element 201, and a P-type diffusion region 322. In this embodiment, the diffusion region 302 is shared with the driving transistor 202. However, this is not limited to this, and the diffusion regions of the driving transistor 202 and the light-emitting control transistor 221 may be independent from each other. The gate electrode 304 is connected to the scanning line 123 as described above.

[0046] In this embodiment, a length 323 in the current flow direction of the diffusion region 306 of the write transistor 203 connected to the gate electrode 301 of the drive transistor 202 is longer than a length 324 in the current flow direction of the diffusion region 302 shared by the drive transistor 202 and the light-emitting control transistor 221. Here, the length 323 in the current flow direction of the diffusion region 306 may be defined as the length from the end of the gate electrode 304 of the write transistor 203 on the diffusion region 306 side to the point where the polarity of the diffusion region 306 and the well 403 changes in the current flow direction (the up and down direction in FIG. 7) in an orthogonal projection onto the surface of the substrate 405 on which the write transistor 203 is arranged, as shown in FIG. Furthermore, the length 323 of the diffusion region 306 in the current flow direction may be defined as the length from the end of the gate electrode 304 of the write transistor 203 on the diffusion region 306 side to the portion in the current flow direction where the impurity concentration of the diffusion region 306 becomes 1 / 2, 1 / 5, or 1 / 10 in the orthogonal projection onto the surface of the substrate 405 on which the write transistor 203 is disposed. Furthermore, the length 324 of the diffusion region 302 in the current flow direction may be defined as the length between the gate electrode 301 of the driving transistor 202 and the gate electrode 321 of the emission control transistor 221 in the current flow direction (the up-down direction in FIG. 7 ) in the orthogonal projection onto the surface of the substrate 405 on which the driving transistor 202 and the emission control transistor 221 are disposed.

[0047] By making the length 323 longer than the length 324, the parasitic capacitance of the P-type diffusion region 306 increases, and it becomes possible to keep the signal voltage written to the gate electrode 301 of the driving transistor 202 connected to the diffusion region 306 more constant. As a result, it is possible to suppress changes in luminance and realize a high-quality display.

[0048] 8, the impurity concentration of the channel region 421 of the light-emission control transistor 221 may be approximately the same as the impurity concentration of the channel region 402 of the write transistor 203, the impurity concentration of the channel region 401 of the drive transistor 202, and the impurity concentration of the channel regions of transistors in the drive circuits (e.g., the vertical scanning circuit 104 and the signal output circuit 105) arranged around the pixel array 103. In other words, the impurity concentration of the light-emission control transistor 221, as well as the impurity concentrations of the channel region 402 of the write transistor 203 and the channel region 401 of the drive transistor 202, may be lower than the impurity concentration of the well 403. Also, as shown in FIG. 8, the channel region 401 of the drive transistor 202 may be a P-type buried channel, similar to the channel region 402 of the write transistor 203 and the channel region 401 of the drive transistor 202. This eliminates the need to increase the number of steps required to form the channel regions of the light-emission control transistor 221, the write transistor 203, the drive transistor 202, and the transistors in the drive circuit of the pixel array 103. Furthermore, by configuring the light-emission control transistor 221 in the same manner as the write transistor 203, it is possible to suppress current fluctuations caused by off-leak current and RTS noise of the light-emission control transistor 221.

[0049] Next, modified examples of the above-described light emitting devices 101 and 121 will be described with reference to Fig. 9 to Fig. 12. Fig. 9 is a schematic diagram showing an example of the configuration of a light emitting device 141 in this embodiment. Fig. 10 is a circuit diagram showing an example of the configuration of a pixel 142 arranged in the light emitting device 141.

[0050] In this embodiment, the pixel 142 of the light emitting device 141 further includes a reset transistor 241 for shorting two terminals of the light emitting device 201, in other words, for connecting the anode of the light emitting device 201 to the power supply potential Vss, as compared to the pixel 122 of the light emitting device 121 described above. Furthermore, in the pixel array 103 of the light emitting device 141, a scanning line 143 for switching the conduction / non-conduction of the reset transistor 241 is arranged in addition to the configuration of the pixel array 103 of the light emitting device 121. Other configurations may be the same as those of the light emitting device 121 described above. The following description will focus on configurations of the light emitting device 141 of this embodiment that are different from those of the light emitting device 121 described above.

[0051] 9, in the pixel array 103, scanning lines 143 extending along the row direction are arranged for each pixel row of the arrayed pixels 142. The scanning lines 143 are connected to the output terminals of the vertical scanning circuit 104 corresponding to the pixel rows, and supply reset signals to the respective pixels 142.

[0052] 10, one of the diffusion regions functioning as the source region and drain region of the reset transistor 241 (the source region in the configuration of FIG. 10) is connected to the anode of the light-emitting element 201 and the other of the diffusion regions functioning as the source region and drain region of the drive transistor 202 (the drain region in the configuration of FIG. 10). The other of the diffusion regions functioning as the source region and drain region of the reset transistor 241 (the drain region in the configuration of FIG. 10) is connected to the power supply potential Vss. The gate electrode of the reset transistor 241 is connected to the scanning line 143.

[0053] During the non-light-emitting period of the pixel 142, by turning on the reset transistor 241, the anode of the light-emitting element 201 is connected to the power supply potential Vss, and two terminals of the light-emitting element 201 are short-circuited. This puts the light-emitting element 201 into a non-light-emitting state (reset operation). By providing the reset transistor 241 in the pixel 142, the light-emitting element 201 can reliably display black during the non-light-emitting period, thereby realizing a light-emitting device 141 with a high contrast ratio. Note that this embodiment does not impair the effects of suppressing the off-leak current of the write transistor 203 and suppressing variations in the write transistor 203, and high-quality display is maintained.

[0054] Next, the reset transistor 241 will be described in detail with reference to Figures 11 and 12. Figure 11 is a plan view showing an outline of the pixel 142, and Figure 12 is a cross-sectional view taken along line Y3-Y3' shown in Figure 11.

[0055] 11 and 12, the reset transistor 241 is composed of a P-type gate electrode 341, a P-type diffusion region 303 that functions as a source region and a drain region, and a diffusion region 342. In this embodiment, the diffusion region 303 is shared with the drive transistor 202. However, this is not limiting, and the diffusion regions of the drive transistor 202 and the reset transistor 241 may be independent from each other. The gate electrode 304 is connected to the scanning line 143 as described above.

[0056] 12, the impurity concentration of the channel region 441 of the reset transistor 241 may be approximately the same as the impurity concentration of the channel region 402 of the write transistor 203, the impurity concentration of the channel region 401 of the drive transistor 202, the impurity concentration of the channel region 421 of the light-emission control transistor 221, and the impurity concentration of the channel regions of the transistors in the circuits of the drive circuits (e.g., the vertical scanning circuit 104 and the signal output circuit 105) arranged in the periphery of the pixel array 103. In other words, the impurity concentration of the reset transistor 241, as well as the impurity concentrations of the channel region 402 of the write transistor 203, the channel region 401 of the drive transistor 202, the channel region 421 of the light-emission control transistor 221, etc., may be lower than the impurity concentration of the well 403. Also, as shown in FIG. 12, the channel region 401 of the drive transistor 202 may be a P-type buried channel, like the channel region 402 of the write transistor 203 and the channel region 401 of the drive transistor 202. This eliminates the need to increase the number of steps required to form the channel regions of the reset transistor 241, write transistor 203, drive transistor 202, light-emission control transistor 221, and transistors in the drive unit circuit arranged around the pixel array 103. Furthermore, by configuring the reset transistor 241 in the same manner as the write transistor 203, it is possible to suppress current fluctuations caused by the off-leak current of the reset transistor 241 and RTS noise.

[0057] 12, the conductivity type of the gate electrode 341 of the reset transistor 241 may be P-type, different from the gate electrode 304 of the write transistor 203. This reduces the threshold voltage of the reset transistor 241, and prevents the anode of the light-emitting element 201 from reaching a potential higher than the power supply potential Vss during the reset operation. By providing the reset transistor 241 in the pixel 142, it is possible to more reliably transition the light-emitting element 201 to a non-light-emitting state, and the light-emitting device 141 can achieve a higher-quality display with higher contrast.

[0058] In the above description, an organic EL element has been cited as the light-emitting element 201, but the light-emitting element 201 is not limited to this. The light-emitting element 201 can be applied to any light-emitting device that uses a current-driven electro-optical element (light-emitting element) whose light emission luminance changes according to the value of a current flowing through the element, such as an inorganic EL element, an LED element, or a semiconductor laser element.

[0059] Here, application examples in which the light emitting devices 101, 121, and 141 of this embodiment are applied to display devices, photoelectric conversion devices, electronic devices, lighting devices, mobile objects, and wearable devices will be described with reference to FIGS. 13 to 19(a) and 19(b).

[0060] FIG. 13 is a schematic diagram illustrating an example of a display device using light-emitting devices 101, 121, and 141 according to 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. Flexible printed circuits FPCs 1002 and 1004 are connected to the touch panel 1003 and the display panel 1005. An active element such as a transistor is disposed on the circuit board 1007. The battery 1008 may not be provided if the display device 1000 is not a portable device, and even if it is a portable device, it does not need to be provided in this position. The light-emitting devices 101, 121, and 141 according to this embodiment can be applied to the display panel 1005. The pixel array 103 of the light emitting devices 101, 121, and 141 that function as a display panel 1005 is connected to and operates with active elements such as transistors arranged on a circuit board 1007.

[0061] The display device 1000 shown in Fig. 13 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.

[0062] FIG. 14 is a schematic diagram illustrating an example of a photoelectric conversion device using the light-emitting devices 101, 121, and 141 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 light-emitting devices 101, 121, and 141 of this embodiment can be applied to the viewfinder 1101 and the rear display 1102, which are display units. In this case, the light-emitting devices 101, 121, and 141 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.

[0063] Since the timing suitable for capturing an image is often very short, it is better to display information as soon as possible. Therefore, light-emitting devices 101, 121, 141 containing an organic light-emitting material such as an organic EL element in the light-emitting layer may be used for the viewfinder 1101 and rear display 1102. This is because organic light-emitting materials have a fast response speed. Light-emitting devices 101, 121, 141 using organic light-emitting materials are more suitable than liquid crystal display devices for these devices, which require high display speed.

[0064] 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.

[0065] The light emitting devices 101, 121, and 141 may be applied to the display unit of an electronic device. In this case, the light emitting devices 101, 121, and 141 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.

[0066] FIG. 15 is a schematic diagram showing an example of an electronic device using the light-emitting devices 101, 121, and 141 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, etc. A portable device having a communication unit can also be called a communication device. The light-emitting device 101 of this embodiment can be applied to the display unit 1201.

[0067] 16(a) and 16(b) are schematic diagrams illustrating examples of display devices using the light-emitting devices 101, 121, and 141 of the present embodiment. FIG. 12(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 light-emitting devices 101, 121, and 141 of the present embodiment 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. 16(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.

[0068] FIG. 16(b) is a schematic diagram illustrating another example of a display device using the light-emitting devices 101, 121, and 141 of this embodiment. The display device 1310 of FIG. 16(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 light-emitting devices 101, 121, and 141 of this embodiment 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 1312 may display a single image.

[0069] FIG. 17 is a schematic diagram illustrating an example of a lighting device using the light-emitting devices 101, 121, and 141 of this embodiment. The lighting 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 light-emitting devices 101, 121, and 141 of this embodiment 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 up, and deliver the light over a wide area. If necessary, a cover may be provided on the outermost part. The lighting device 1400 may include both the optical film 1404 and the light diffusion unit 1405, or only one of them.

[0070] 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 adjusts the light intensity. The lighting device 1400 may have a power supply circuit connected to the light-emitting devices 101, 121, and 141 that function as light sources 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 sink. The heat sink dissipates heat from within the device to the outside, and examples of the heat sink include metal with a high specific heat, liquid silicon, etc.

[0071] FIG. 18 is a schematic diagram of an automobile having a tail lamp, which is an example of a vehicle lamp using the light-emitting devices 101, 121, and 141 of this embodiment. The automobile 1500 may have a tail lamp 1501 that is turned on when braking or the like is performed. The light-emitting devices 101, 121, and 141 of this embodiment may be used as headlamps as vehicle lamps. An automobile is an example of a mobile body, and the mobile body may be a ship, a drone, an aircraft, a railcar, 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.

[0072] The light emitting devices 101, 121, and 141 of this embodiment can be applied to a tail lamp 1501. The tail lamp 1501 may have a protective member that protects the light emitting devices 101, 121, and 141 that function 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.

[0073] The automobile 1500 may have a body 1503 and a window 1502 attached to the body. The window may be a window for checking the front and rear of the automobile, or may be a transparent display. The light-emitting devices 101, 121, and 141 of the present embodiment may be used in the transparent display. In this case, the constituent materials of the electrodes and the like of the light-emitting devices 101, 121, and 141 are made of transparent materials.

[0074] 19(a) and 19(b), further application examples of the light emitting devices 101, 121, and 141 of the present embodiment will be described. The light emitting devices 101, 121, and 141 can be applied to systems that can be worn as wearable devices, such as smart glasses, head-mounted displays (HMDs), and 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.

[0075] 19(a) illustrates glasses 1600 (smart glasses) according to one application example. An imaging device 1602 such as a CMOS sensor or a SPAD is provided on the front side of a lens 1601 of the glasses 1600. Furthermore, light emitting devices 101, 121, and 141 of this embodiment are provided on the back side of the lens 1601.

[0076] 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 light emitting devices 101, 121, and 141 according to each embodiment. The control device 1603 also controls the operations of the image capture device 1602 and the light emitting devices 101, 121, and 141. The lens 1601 is formed with an optical system for focusing light onto the image capture device 1602.

[0077] FIG. 19(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 light-emitting devices 101, 121, and 141. A lens 1611 includes an optical system for projecting light emitted from the imaging device in the control device 1612 and the light-emitting devices 101, 121, and 141, and an image is projected onto the lens 1611. The control device 1612 functions as a power source that supplies power to the imaging devices and the light-emitting devices 101, 121, and 141, and also controls the operation of the imaging devices and the light-emitting devices 101, 121, and 141. The control device 1612 may include a gaze detection unit that detects the gaze of the wearer. Infrared light may be used for gaze detection. The infrared light-emitting unit emits infrared light toward the eyes of a user gazing at a displayed image. The image capturing unit detects the reflected light of the emitted infrared light from the eyeball, thereby obtaining an image of the eyeball. The inclusion of a reduction unit that reduces the light from the infrared light emitting unit to the display unit in a planar view reduces degradation of image quality.

[0078] 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.

[0079] 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.

[0080] The light emitting devices 101, 121, and 141 according to an embodiment of the present invention may have an imaging device having a light receiving element, and may control the display image based on information on the user's line of sight from the imaging device.

[0081] Specifically, the light-emitting devices 101, 121, and 141 determine 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 light-emitting devices 101, 121, and 141, or may receive data determined by an external control device. In the display area of ​​the light-emitting devices 101, 121, and 141, 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.

[0082] 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 display area and the second display area may be determined by a control device of the light-emitting device 101, 121, or 141, 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.

[0083] 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 the image of the eyeball, using as training data an image of the eyeball and the actual direction in which the eyeball in the image was looking. The AI ​​program may be included in the light-emitting device 101, 121, or 141, in the imaging device, or in an external device. If included in an external device, the AI ​​program is transmitted to the light-emitting device 101, 121, or 141 via communication.

[0084] 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.

[0085] The disclosure of this specification includes the following light-emitting devices, display devices, photoelectric conversion devices, electronic devices, lighting devices, and mobile objects.

[0086] (Item 1) A light emitting device in which a pixel is arranged, the pixel including a light emitting element, a first transistor that supplies a current corresponding to a luminance signal to the light emitting element, and a second transistor that supplies the luminance signal to a gate electrode of the first transistor, the diffusion regions functioning as the source and drain regions of the second transistor are of the first conductivity type; a gate electrode of the second transistor having a second conductivity type opposite to the first conductivity type;

[0087] (Item 2) the first transistor and the second transistor are disposed in the second conductivity type well; 2. The light emitting device according to item 1, wherein the impurity concentration of the channel region of the second transistor is lower than the impurity concentration of the well.

[0088] (Item 3) 3. The light emitting device according to item 2, wherein the impurity concentration of the channel region of the first transistor is the same as the impurity concentration of the channel region of the second transistor.

[0089] (Item 4) 4. The light emitting device according to item 2 or 3, wherein the channel region of the second transistor is of the first conductivity type.

[0090] (Item 5) 4. The light emitting device according to item 3, wherein the channel region of the first transistor and the channel region of the second transistor are of a first conductivity type.

[0091] (Item 6) a diffusion region that functions as a source region and a drain region of the first transistor is of the first conductivity type; 6. The light emitting device according to item 5, wherein the gate electrode of the first transistor is of the second conductivity type.

[0092] (Item 7) the light-emitting device includes a pixel array in which a plurality of the pixels are arranged, and a peripheral region in which a drive circuit for operating the plurality of pixels is arranged, a third transistor having a channel region of the first conductivity type is disposed in the peripheral region; 7. The light emitting device according to any one of items 4 to 6, wherein the impurity concentration of the channel region of the second transistor is the same as the impurity concentration of the channel region of the third transistor.

[0093] (Item 8) 8. The light-emitting device according to any one of items 1 to 7, wherein the pixel further includes a fourth transistor arranged in a current path including the light-emitting element and the first transistor, and controlling whether the light-emitting element emits light or not.

[0094] (Item 9) one of the source region and the drain region of the first transistor and the other of the source region and the drain region of the fourth transistor share one diffusion region; Item 9. The light-emitting device according to item 8, wherein the length in the direction of current flow of the diffusion region of the second transistor connected to the gate electrode of the first transistor is longer than the length in the direction of current flow of the diffusion region shared by the first transistor and the fourth transistor.

[0095] (Item 10) the pixel further includes a fourth transistor disposed in a current path including the light emitting element and the first transistor, for controlling whether the light emitting element emits light, and 8. The light emitting device according to any one of items 2 to 7, wherein the impurity concentration of the channel region of the second transistor and the impurity concentration of the channel region of the fourth transistor are the same.

[0096] (Item 11) Item 11. The light emitting device according to item 10, wherein the channel region of the second transistor and the channel region of the fourth transistor are of a first conductivity type.

[0097] (Item 12) a diffusion region that functions as a source region and a drain region of the fourth transistor is of the first conductivity type; Item 12. The light emitting device according to item 11, wherein the gate electrode of the fourth transistor is of the second conductivity type.

[0098] (Item 13) the pixel further includes a fifth transistor shorting two terminals of the light-emitting element; 13. The light emitting device according to any one of items 2 to 12, wherein the impurity concentration of the channel region of the second transistor and the impurity concentration of the channel region of the fifth transistor are the same.

[0099] (Item 14) Item 14. The light emitting device according to item 13, wherein the channel region of the second transistor and the channel region of the fifth transistor are of a first conductivity type.

[0100] (Item 15) a diffusion region that functions as a source region and a drain region of the fifth transistor is of the first conductivity type; Item 15. The light emitting device according to item 14, wherein the gate electrode of the fifth transistor is of the first conductivity type.

[0101] (Item 16) 16. A display device comprising: the light-emitting device according to any one of items 1 to 15; and an active element connected to the light-emitting device.

[0102] (Item 17) 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; 16. A photoelectric conversion device, wherein the display unit is a display unit that displays an image captured by the imaging element, and the photoelectric conversion device comprises the light-emitting device according to any one of items 1 to 15.

[0103] (Item 18) A display unit is provided in the housing, and a communication unit is provided in the housing and communicates with an external device. 16. An electronic device, wherein the display unit comprises the light-emitting device according to any one of items 1 to 15.

[0104] (Item 19) A lighting device having a light source and at least one of a light diffusion unit and an optical film, 16. A lighting device, wherein the light source comprises the light emitting device according to any one of items 1 to 15.

[0105] (Item 20) A moving body having a body and a lighting fixture provided on the body, The lighting fixture is a moving body having the light emitting device according to any one of items 1 to 15.

[0106] 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]

[0107] 101, 121, 141: light emitting device, 102, 122, 142: pixel, 201: light emitting element, 301, 304, 321, 341: gate electrode, 302, 303, 305, 306, 322, 342: diffusion region

Claims

1. A light-emitting device including a pixel including a light-emitting element, a first transistor that supplies a current corresponding to a luminance signal to the light-emitting element, and a second transistor that supplies the luminance signal to a gate electrode of the first transistor, a diffusion region that functions as a source region and a drain region of the second transistor is of a first conductivity type; a gate electrode of the second transistor being of a second conductivity type opposite to the first conductivity type;

2. the first transistor and the second transistor are disposed in a well of the second conductivity type; 2. The light emitting device according to claim 1, wherein the impurity concentration of the channel region of the second transistor is lower than the impurity concentration of the well.

3. 3. The light emitting device according to claim 2, wherein an impurity concentration of the channel region of the first transistor is the same as an impurity concentration of the channel region of the second transistor.

4. 3. The light emitting device according to claim 2, wherein the channel region of the second transistor is of the first conductivity type.

5. 4. The light emitting device according to claim 3, wherein the channel region of the first transistor and the channel region of the second transistor are of a first conductivity type.

6. a diffusion region that functions as a source region and a drain region of the first transistor is of the first conductivity type; 6. The light emitting device according to claim 5, wherein a gate electrode of the first transistor is of the second conductivity type.

7. The light emitting device includes a pixel array in which a plurality of the pixels are arranged, and a peripheral region in which a drive circuit for operating the plurality of the pixels is arranged, a third transistor having a channel region of the first conductivity type is disposed in the peripheral region; 5. The light emitting device according to claim 4, wherein the impurity concentration of the channel region of the second transistor is the same as the impurity concentration of the channel region of the third transistor.

8. 2 . The light emitting device according to claim 1 , wherein the pixel further comprises a fourth transistor arranged in a current path including the light emitting element and the first transistor, the fourth transistor controlling whether the light emitting element emits light or not.

9. one of the source region and the drain region of the first transistor and the other of the source region and the drain region of the fourth transistor share one diffusion region; 9. The light-emitting device according to claim 8, wherein a length in a direction in which a current flows of the diffusion region of the second transistor connected to the gate electrode of the first transistor is longer than a length in a direction in which a current flows of the diffusion region shared by the first transistor and the fourth transistor.

10. the pixel further includes a fourth transistor disposed in a current path including the light emitting element and the first transistor, the fourth transistor controlling whether the light emitting element emits light or not, 3. The light emitting device according to claim 2, wherein the impurity concentration of the channel region of the second transistor is the same as the impurity concentration of the channel region of the fourth transistor.

11. 11. The light emitting device of claim 10, wherein the channel region of the second transistor and the channel region of the fourth transistor are of the first conductivity type.

12. a diffusion region that functions as a source region and a drain region of the fourth transistor is of the first conductivity type; 12. The light emitting device according to claim 11, wherein a gate electrode of the fourth transistor is of the second conductivity type.

13. The pixel further includes a fifth transistor shorting two terminals of the light-emitting element; 2. The light emitting device according to claim 1, wherein a gate electrode of the fifth transistor is of the first conductivity type.

14. the pixel further includes a fifth transistor shorting two terminals of the light-emitting element; 3. The light emitting device according to claim 2, wherein the impurity concentration of the channel region of the second transistor is the same as the impurity concentration of the channel region of the fifth transistor.

15. 15. The light emitting device of claim 14, wherein the channel region of the second transistor and the channel region of the fifth transistor are of a first conductivity type.

16. a diffusion region that functions as a source region and a drain region of the fifth transistor is of the first conductivity type; 16. The light emitting device according to claim 15, wherein a gate electrode of the fifth transistor is of the first conductivity type.

17. A display device comprising: a light-emitting device according to claim 1 ; and an active element connected to the light-emitting device.

18. The imaging device includes 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, 17. A photoelectric conversion device, comprising: the display unit for displaying an image captured by the imaging element; and the light-emitting device according to claim 1.

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

17. An electronic device, comprising: a display unit comprising the light-emitting device according to claim 1.

20. A lighting device having a light source and at least one of a light diffusion unit and an optical film, 17. An illumination device, characterized in that the light source comprises a light emitting device according to claim 1.

21. A moving body having a body and a lighting device provided on the body, A moving body, wherein the lighting device comprises the light emitting device according to claim 1 .

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