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

Abstract

To provide a technique advantageous for reducing the time from start-up until image display while maintaining image quality at the start-up.SOLUTION: A light-emitting device includes: a plurality of pixels that each include a luminous element and a drive transistor supplying current according to a luminance signal to the luminous element, and are arranged to form a plurality of rows and a plurality of columns; and a drive circuit including a scanning circuit that performs writing scanning of scanning the plurality of pixels row by row and writing the luminance signal to gates of the drive transistors. The drive circuit performs, from the start-up of the light-emitting device until the start of the writing scanning, a signal writing operation of collectively writing predetermined signals in the gates of the drive transistors included in pixels arranged in two or more rows of the plurality of pixels.SELECTED DRAWING: Figure 5

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] When the light emitting device is started up, the gate potential of the drive transistor that supplies a current to the light emitting element according to a luminance signal may become unstable, which may result in the appearance of bright lines in some areas. Patent Document 1 shows that a signal voltage is written to all pixel circuits of the display unit when the power is turned on in order to maintain good image quality when the power is turned on. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-114476 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the driving method of Patent Document 1, since writing scanning for one frame is performed after power is turned on and before image display starts, it takes time before image display starts.

[0005] An object of the present invention is to provide a technique that is advantageous for shortening the time from startup to image display while maintaining image quality at the time of startup. [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 including a plurality of pixels arranged to form a plurality of rows and a plurality of columns, each of which includes a light-emitting element and a drive transistor that supplies a current to the light-emitting element in accordance with a luminance signal, and a drive circuit having a scanning circuit that scans the plurality of pixels row by row and performs a write scan to write the luminance signal to the gates of the drive transistors, wherein the drive circuit performs a signal write operation to write a predetermined signal collectively to the gates of the drive transistors included in pixels arranged in two or more rows among the plurality of pixels between the start-up of the light-emitting device and the start of the write scan. Effect of the Invention

[0007] According to the present invention, it is possible to provide a technique that is advantageous for shortening the time from startup to image display while maintaining the image quality at the time of startup. [Brief description 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; [Diagram 2] FIG. 2 illustrates an example of the configuration of a pixel in the light-emitting device of FIG. [Diagram 3] FIG. 2 is a diagram showing an example of the configuration of a driver circuit of the light-emitting device in FIG. [Figure 4] 2 is a diagram showing an example of the configuration of a signal output circuit of the light emitting device in FIG. 1; [Diagram 5] 2 is a timing chart showing an example of the operation of the light emitting device of FIG. 1. [Figure 6] 2 is a diagram showing an example of the configuration of a signal output circuit of the light emitting device in FIG. 1; [Figure 7] 2 is a diagram showing an example of the configuration of a signal output circuit of the light emitting device in FIG. 1; [Figure 8] 8 is a diagram showing an example of the configuration of a driver circuit of the signal output circuit of FIG. 7. [Figure 9] FIG. 2 is a diagram showing a modification of the light emitting device in FIG. [Figure 10] 10 is a diagram showing an example of the configuration of a signal output circuit of the light emitting device in FIG. [Figure 11] 10 is a timing chart showing an example of the operation of the light emitting device of FIG. [Figure 12] FIG. 2 is a diagram showing a modification of the light emitting device in FIG. [Figure 13] 13 is a diagram showing a configuration example of a pixel of the light emitting device in FIG. 12. [Figure 14] FIG. 13 is a diagram showing an example of the configuration of a driver circuit of the light emitting device in FIG. [Figure 15] 13 is a timing chart showing an example of the operation of the light emitting device of FIG. 12. [Figure 16] FIG. 2 is a diagram showing an example of the configuration of a driver circuit of the light-emitting device in FIG. [Figure 17] 17 is a timing chart showing an example of the operation of a light emitting device including the drive circuit of FIG. 16. [Figure 18] 2 is a cross-sectional view showing a configuration example of a pixel of the light-emitting device in FIG. [Figure 19] FIG. 1 is a diagram showing an example of an image forming apparatus using a light emitting device according to an embodiment of the present invention. [Figure 20] FIG. 1 is a diagram showing an example of a display device using the light-emitting device of this embodiment. [Figure 21] FIG. 1 is a diagram showing an example of a photoelectric conversion device using a light emitting device according to an embodiment of the present invention. [Figure 22] 1A to 1C are diagrams illustrating examples of electronic devices using the light-emitting device of this embodiment. [Figure 23] FIG. 1 is a diagram showing an example of a display device using the light-emitting device of this embodiment. [Figure 24] FIG. 1 is a diagram showing an example of a lighting device using the light-emitting device of the present embodiment. [Diagram 25] FIG. 1 is a diagram showing an example of a moving object using the light emitting device of the present embodiment. [Figure 26] 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 PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0010] A light emitting device according to an embodiment of the present disclosure will be described with reference to Figs. 1 to 17. Fig. 1 is a schematic diagram showing a configuration example of a light emitting device 100 of this embodiment. The light emitting device 100 includes a pixel array 105, a drive circuit 200, a signal output circuit 300, and a control circuit 400. The pixel array 105 includes a plurality of pixels 101 arranged to form a plurality of rows and a plurality of columns. Each of the plurality of pixels 101 includes a light emitting element and a drive transistor that supplies a current to the light emitting element according to a luminance signal, as will be described in detail later. The light emitting element can be, for example, an organic electroluminescence (EL) element, a light emitting diode (LED), a semiconductor laser element, or the like.

[0011] Each of the multiple pixels 101 is connected to a drive circuit 200 via a scanning line 102 commonly arranged for each row corresponding to pixels arranged in a row direction (in FIG. 1, the row direction is the horizontal direction) among the multiple pixels 101. Also, each of the multiple pixels 101 is connected to a signal output circuit 300 via a signal line 103 commonly arranged for each column corresponding to pixels arranged in a column direction (in FIG. 1, the column direction is the vertical direction) among the multiple pixels 101.

[0012] The control circuit 400 controls the drive circuit 200 and the signal output circuit 300. The signal output circuit 300 supplies a luminance signal to the pixel 101 via a signal line 103 under the control of the control circuit 400. The drive circuit 200 selects a row (hereinafter, may be referred to as a write row) of the plurality of pixels 101 in the pixel array 105 to which a luminance signal is to be written under the control of the control circuit 400. An individual luminance signal is written for each column from the signal output circuit 300 via the signal line 103 to the pixels 101 arranged in the selected write row, and the light-emitting element emits light at a luminance according to the luminance signal.

[0013] 2 is a diagram showing an example of the configuration of a pixel 101 in this embodiment. The pixel 101 may include a light emitting element 110, a driving transistor 120, a writing transistor 121, and a capacitive element 130. In the following description, the driving transistor 120 and the writing transistor 121 are described as P-type transistors, but N-type transistors may also be used. In that case, the potentials and polarities shown below may be appropriately interchanged. For example, the source and drain of each transistor may be interchanged.

[0014] The source of the driving transistor 120 is connected to a power supply line 141 that supplies a potential VDD. The drain of the driving transistor 120 is connected to an anode of the light-emitting element 110, the cathode of which is connected to a power supply line 142 that supplies a potential VSS. The potential VDD supplied to the power supply line 141 may be a positive potential. The potential VSS supplied to the power supply line 142 may be a potential lower than the potential VDD. For example, the potential VSS may be a ground potential. A current path including the light-emitting element 110 and the driving transistor 120 is arranged between the power supply line 141 and the power supply line 142.

[0015] The gate of the driving transistor 120 is connected to one of two terminals of a capacitive element 130, the other of which is connected to a power supply line 141. Furthermore, the gate of the driving transistor 120 is connected to a drain of a writing transistor 121. A source of the writing transistor 121 is connected to a signal line 103. Furthermore, a gate of the writing transistor 121 is connected to a scanning line 102.

[0016] In the above configuration, the write transistor 121 arranged between the gate of the drive transistor 120 and the signal line 103 is controlled to be turned on or off by the drive circuit 200. When the drive circuit 200 turns on the write transistor 121, the luminance signal output from the signal output circuit 300 to the signal line 103 of each column is input to the capacitance element 130, and writing of the luminance signal to the pixel 101 (the gate of the drive transistor 120) is started. After that, the drive circuit 200 turns off the write transistor 121, and the capacitance element 130 holds the written luminance signal, and writing of the luminance signal to the pixel 101 (the gate of the drive transistor 120) is completed. The emission luminance of the light emitting element 110 is determined by the current supplied from the drain of the drive transistor 120. Therefore, the light emitting element 110 emits light with a luminance according to the luminance signal written to the gate of the drive transistor 120.

[0017] 3 is a diagram showing an example of the configuration of the drive circuit 200 in this embodiment. The drive circuit 200 includes a scanning circuit 201 and a writing circuit 202. The scanning circuit 201 is provided with an output for each row, and selects the writing rows in row sequence. That is, the scanning circuit 201 scans the pixels 101 row by row, and performs a write scan to write a luminance signal supplied from the signal output circuit 300 to the gate of the drive transistor 120. The writing circuit 202 controls the writing of the pixels 101 via the scanning line 102 based on the output of the scanning circuit 201 and a control signal INIT1 supplied from the control circuit 400.

[0018] FIG. 4 is a diagram showing an example of the configuration of the signal output circuit 300 in this embodiment. The signal output circuit 300 may include a horizontal scanning circuit 301, a DAC circuit 302, and a driver circuit 303. Image signals are input from the control circuit 400 to the horizontal scanning circuit 301 in a column-sequential manner. The horizontal scanning circuit 301 distributes the input image signals to the corresponding columns and holds them. The DAC circuit 302 converts the held image signals into analog signal voltages for each column. The driver circuit 303 buffers the converted analog signal voltages for each column and outputs them as luminance signals to the corresponding signal lines 103. A potential Vinit is supplied to an output node of the driver circuit 303 that outputs a luminance signal to the signal line 103 via a switch 304. The switch 304 is controlled to be turned on or off by a control signal INIT2 output from the control circuit 400. The control signal INIT2 also controls the output state of the driver circuit 303.

[0019] Next, the operation from the start of the light emitting device 100 to the start of display according to an image signal (hereinafter, may be referred to as image display) will be described using an operation timing diagram. Fig. 5 is a timing diagram showing an example of the operation of the light emitting device 100 in this embodiment. For ease of understanding, the number of rows of pixels 101 arranged in the pixel array 105 is illustrated as eight rows.

[0020] At time t0, the light emitting device 100 is powered off. At time t1, the light emitting device 100 is started up (the power transitions to the on state), and the supply of potential VDD begins to be applied to the power supply line 141. When the potential VDD is applied to the power supply line 141, the control circuit 400 controls both the control signal INIT1 and the control signal INIT2 to the LO level.

[0021] When the write circuit 202 of the drive circuit 200 is supplied with a LO level as the control signal INIT1, it supplies a signal to all the scanning lines 102 to turn on the write transistors 121, thereby turning on the write transistors 121. When the signal output circuit 300 is supplied with a LO level as the control signal INIT2, the switch 304 is turned on and the potential Vinit is supplied to the signal line 103. This causes the write circuit 202 of the drive circuit 200 to perform a signal write operation to collectively write the potential Vinit as a predetermined signal to all the pixels 101 of the plurality of pixels 101 arranged in the pixel array 105. As a result, the voltage Vinit is written to the gates of the drive transistors 120 of all the pixels 101.

[0022] At time t2, a certain time after time t1, the control signal INIT1 goes to HI level. When the control signal INIT1 goes to HI level, the write circuit 202 of the drive circuit 200 turns off the write transistor 121 via the scanning line 102. At this point, writing of a predetermined signal (potential Vinit) to the pixel 101 is completed. At the following time t3, the control signal INIT2 goes to HI level. When the control signal INIT2 goes to HI level, the buffer function of the driver circuit 303 in the signal output circuit 300 is enabled, and the driver circuit 303 becomes able to output a luminance signal according to an image signal for subsequent image display.

[0023] Next, at time t4, a vertical sync signal and a horizontal sync signal are generated by the control circuit 400, and an image signal is input after a predetermined blanking period. In response to this, image display begins. Specifically, the signal output circuit 300 outputs an analog voltage signal based on the image signal as a luminance signal to the signal line 103. The drive circuit 200 selects a write row in row sequence for each horizontal period. When the control signal INIT1 becomes HI level, the write circuit 202 of the drive circuit 200 controls the writing of the pixel 101 via the scan line 102 based on the signal output by the scan circuit 201.

[0024] Here, attention is focused on the period from time t1 when the light emitting device 100 is started and a potential VDD is applied to the power supply line 141 to the start of image display. During this period, a potential Vinit is continuously applied to the gate of the driving transistor 120 of each pixel 101 as a predetermined signal. In this embodiment, the potential Vinit is set to a non-light emitting potential. The non-light emitting potential refers to a potential at a level at which the light emission of the light emitting element 110 is not visible even when input to the gate of the driving transistor 120, or a potential at a light emission level at which the light emitting device 100 emits light at its start without causing any sense of incongruity. For example, the non-light emitting potential is a potential at which the luminance of the light emitting element 110, which is difficult to see, is 0.1 cd / m 2 or a potential at which the luminance of the light emitting element becomes equal to or lower than the black level of the luminance signal.

[0025] In this way, the driving circuit 200 writes the potential Vinit as a predetermined signal collectively to the gates of the driving transistors 120 included in the plurality of pixels 101 during the period from the start of the light emitting device 100 to the start of image display by the write scan in which the scanning circuit 201 scans the plurality of pixels 101 row by row and writes a luminance signal to the gate of the driving transistor 120. Therefore, the driving circuit 200 includes a write circuit 202 that does not perform scanning using the scanning circuit 201 during the period from the start of the light emitting device 100 to the start of the write scan by the scanning circuit 201 and writes a predetermined signal to the gates of the driving transistors 120 included in the plurality of pixels 101. By setting this potential Vinit to a non-light emitting potential, the pixels 101 can be maintained in a non-light emitting state until the start of image display. In this way, light emission at the start of the light emitting device 100 can be suppressed without performing row scanning using the scanning circuit 201 during the period from the start of the light emitting device 100 to the start of image display. In addition, in this embodiment, the potential Vinit is supplied collectively to the pixels 101 arranged in the pixel array 105. Therefore, the time from starting up the light emitting device 100 to starting image display can be made shorter than when the potential Vinit is supplied by performing scanning for one frame using the scanning circuit 201. In other words, it is possible to shorten the time from starting up the light emitting device 100 to displaying an image while maintaining the image quality at the time of starting up the light emitting device 100.

[0026] In the above-described configuration of the light emitting device 100, the potential Vinit supplied as a predetermined signal to the gate of the driving transistor 120 of each pixel 101 when the light emitting device 100 is started may be the same potential as the potential VDD supplied to the power supply line 141. The power supply line supplying the potential Vinit shown in FIG. 4 and the power supply line 141 may be supplied with a potential from a common power supply. For example, the power supply line supplying the potential Vinit shown in FIG. 4 may branch off from the power supply line 141. By sharing the power supply line supplying the potential Vinit with the power supply line 141, the wiring pattern arranged in the pixel array 105 can be reduced compared to the case where they are arranged separately.

[0027] When the potential Vinit is set to the same potential as the potential VDD, the voltage applied between the gate and source of the driving transistor 120 becomes approximately 0 V. Therefore, even when the potential VDD is used as the potential Vinit, the pixel 101 is in a non-emitting state as in the configuration example described above, and the same effect as described above can be obtained.

[0028] Strictly speaking, even if the same potential is supplied between the potential Vinit and the potential VDD, a difference may occur due to a voltage drop caused by the wiring resistance of the power supply line 141 or the power supply line that supplies the potential Vinit. Here, it is defined that the potential Vinit and the potential VDD are the same, including such a difference.

[0029] In the above-described configuration, the potential Vinit is input to the gate of the driving transistor 120 via the signal line 103 and the write transistor 121 when the light-emitting device 100 is started up, but the present invention is not limited to this. A signal line to which the above-described potential Vinit is supplied as a predetermined signal may be provided in addition to the signal line 103, and an additional write transistor other than the write transistor 121 may be provided between the signal line to which the potential Vinit is supplied to the pixel 101 and the gate of the driving transistor 120. As a result, during the period from the start of the light-emitting device 100 to the start of write scanning for image display using the scanning circuit 201, the write circuit 202 of the driving circuit 200 turns on the additional write transistor, thereby writing Vinit as a predetermined signal to the gate of the driving transistor 120.

[0030] Furthermore, in the above-mentioned configuration, the control circuit 400 supplies different signals as the control signal INIT1 and the control signal INIT2, but the present invention is not limited to this. For example, the control circuit 400 may supply the same signal as the control signal INIT1 and the control signal INIT2. It is sufficient that the drive circuit 200 can turn off the write transistor 121 after a predetermined signal (potential Vinit) is written to the gate of the drive transistor 120 and before the signal supplied from the signal output circuit 300 to the signal line 103 changes from the predetermined signal (potential Vinit). When the same signal is supplied to the control signal INIT1 and the control signal INIT2, for example, a buffer circuit that delays the control signal INIT2 may be arranged at a node to which the control signal INIT2 of the signal output circuit 300 is input.

[0031] Furthermore, in this embodiment, in response to the start-up of the light emitting device 100, the drive circuit 200 performs a signal writing operation of writing a predetermined signal (potential Vinit) to the gate of the drive transistor 120 of each pixel 101 in accordance with the control signals INIT1 and INIT2 supplied from the control circuit 400. However, other control signals may be used as long as the drive circuit 200 can perform a signal writing operation in response to the start-up of the light emitting device 100. For example, a signal for the drive circuit 200 to start the signal writing operation may be supplied from outside the light emitting device 100. In addition, for example, the drive circuit 200 may start the signal writing operation triggered by the start-up of the light emitting device 100 (for example, power-on or return from a sleep state).

[0032] Fig. 6 is a diagram showing a modification of the signal output circuit 300 shown in Fig. 4. The connection position of the switch 304 is different from that shown in Fig. 4. In the signal output circuit 300 shown in Fig. 6, a potential Vinit is supplied to an input node of a driver circuit 303 of the signal output circuit 300 via a switch 304. It can also be said that the switch 304 is connected to a node connecting the DAC circuit 302 and the driver circuit 303.

[0033] The switch 304 is controlled to be turned on or off by a control signal INIT2 output from the control circuit 400. The control signal INIT2 supplied from the control circuit 400 also controls the output state of the DAC circuit 302. When the control signal INIT2 is at a HI level, the switch 304 is turned off, and the digital-to-analog conversion function of the DAC circuit 302 is enabled. Therefore, a luminance signal corresponding to the image signal is supplied to the signal line 103 via the driver circuit 303. On the other hand, when the control signal INIT2 is at a LO level, the switch 304 is turned on, and the DAC circuit 302 becomes a high impedance output. Therefore, a potential Vinit is supplied to the signal line 103 via the driver circuit 303.

[0034] 6, the light emitting device 100 operates in the same manner as described above, and therefore the same effects as those of the light emitting device 100 described above can be obtained.

[0035] Fig. 7 is a diagram showing a modification of the signal output circuit 300 shown in Fig. 4 and Fig. 6. The signal output circuit 300 shown in Fig. 7 does not include a switch 304. The following description will focus on configurations that are different from the signal output circuit 300 shown in Fig. 4 and Fig. 6. Also, in the signal output circuit 300 shown in Fig. 7, descriptions of configurations that may be similar to those of the signal output circuit 300 shown in Fig. 4 and Fig. 6 will be omitted as appropriate.

[0036] The driver circuit 303 shown in FIG. 7 includes an operational amplifier 305 corresponding to the signal line 103 arranged for each column. The output of the DAC circuit 302 is connected to the non-inverting input terminal of the operational amplifier 305 for each column. The inverting input terminal of the operational amplifier 305 is connected to the output terminal of the operational amplifier 305. The inverting input terminal and the output terminal of the operational amplifier 305 are further connected to the signal line 103. With this configuration, the operational amplifier 305 forms a voltage follower with an input terminal connected to the output of the DAC circuit 302 and an output terminal connected to the signal line 103. Therefore, the luminance signal output from the DAC circuit 302 is buffered by the operational amplifier 305 and output to the signal line 103. The output state of the operational amplifier 305 is controlled by a control signal INIT2 supplied from the control circuit 400.

[0037] 8 is a diagram showing a specific example of the configuration of the operational amplifier 305. The operational amplifier 305 may include an input stage 306, a gain stage 307, and an output stage 308, similar to a general operational amplifier. The input stage 306 amplifies the input differential signal. The gain stage 307 further amplifies the output of the input stage 306. The output stage 308 buffers the output of the gain stage 307.

[0038] The output stage 308 may include a P-type transistor 309, an N-type transistor 310, and switches 311 to 314. The drains of the transistors 309 and 310 are connected to each other and are connected to the signal line 103 as the output terminal of the output stage 308. The source of the transistor 309 is connected to a power supply line 141 that supplies a potential VDD. The source of the transistor 310 is connected to a power supply line 142. In this embodiment, the power supply line to which the source of the transistor 310 is connected supplies a potential VSS. However, this is not limited to this, and the power supply line connected to the source of the transistor 310 may supply a potential different from the potential VSS. With this configuration, the transistors 309 and 310 form a source-grounded push-pull circuit. The output of the gain stage 307 is input to the gates of the transistors 309 and 310 via the switches 313 and 314, respectively. The gate of the transistor 309 is connected to the power supply line 142 that supplies the potential VSS via the switch 311. On the other hand, the gate of the transistor 310 is connected via a switch 312 to the power supply line 141 that supplies the potential VSS.

[0039] The switches 311 to 314 are controlled by a control signal INIT2 supplied from the control circuit 400. When the control signal INIT2 is at a HI level, the switches 311 and 312 are turned off, and the switches 313 and 314 are turned on. Therefore, the output stage 308 buffers the signal output from the gain stage 307. On the other hand, when the control signal INIT2 is at a LO level, the switches 311 and 312 are turned on, and the switches 313 and 314 are turned off. Therefore, the transistor 309 is supplied with the potential VSS at its gate and turned on, and the transistor 310 is supplied with the potential VSS at its gate and turned off. Therefore, the potential VDD is output to the signal line 103.

[0040] In this way, the driver circuit 303 is configured to be able to selectively output the luminance signal supplied from the DAC circuit 302 and the potential VDD that functions as the potential Vinit as described above. The switching between the luminance signal and the potential VDD is in accordance with the control signal INIT2 supplied from the control circuit 400 as described above. That is, even if the signal output circuit 300 has the configuration shown in Figs. 7 and 8, the light emitting device 100 operates in the same manner as described above. Therefore, the same effect as that of the light emitting device 100 described above can be obtained.

[0041] Fig. 9 is a diagram showing a modified example of the light emitting device 100 shown in Fig. 1. Compared with the configuration shown in Fig. 1, the light emitting device 100 shown in Fig. 9 further includes a detection circuit 500 that detects the potential of the power supply line 141. The following description will focus on configurations that are different from those of the light emitting device 100 shown in Fig. 1, and descriptions of configurations that may be similar will be omitted as appropriate.

[0042] The detection circuit 500 has a function of detecting the rising of the potential of the power supply line 141 that supplies the potential VDD. The detection circuit 500 also outputs the detection result of the potential of the power supply line 141 as a control signal INIT1 to the drive circuit 200 and the signal output circuit 300. Specifically, when the potential of the power supply line 141 is lower than a predetermined potential Vdtct after the light emitting device 100 is started up, the detection circuit 500 supplies a LO level as the control signal INIT1. On the other hand, when the detection circuit 500 detects that the potential of the power supply line 141 has reached the predetermined potential Vdtct, it supplies a HI level as the control signal INIT1.

[0043] Fig. 10 is a diagram showing an example of the configuration of a signal output circuit 300 disposed in the light emitting device 100 shown in Fig. 9. A control signal INIT1 is input to the signal output circuit 300 instead of the above-mentioned control signal INIT2. Therefore, the on / off of a switch 304 is controlled by the control signal INIT1. In addition, a power supply line 141 is connected to an output node of the signal output circuit 300 via the switch 304.

[0044] Fig. 11 is a timing diagram showing an example of the operation of the light emitting device 100 including the detection circuit 500 shown in Fig. 9. As in the timing diagram shown in Fig. 5, the number of rows of the pixels 101 arranged in the pixel array 105 is illustrated as eight.

[0045] At time t1, when the light emitting device 100 is started and the potential of the power supply line 141 starts to rise toward the potential VDD, the detection circuit 500 sets the control signal INIT1 to the LO level. When the LO level is supplied as the control signal INIT1, the drive circuit 200 starts a signal writing operation to write the signal (potential) supplied to the signal line 103 to the gate of the drive transistor 120, as described above. Therefore, the potential of the power supply line 141 is input to the gate of the drive transistor 120 of all the pixels 101. After time t1, the power supply line 141 continues to change with the rise of the power supply. Therefore, the signal (potential) input to the gate of the drive transistor 120 also changes following the potential of the power supply line 141.

[0046] At time t2, when the potential of the power supply line 141 reaches a predetermined potential Vdtct, the detection circuit 500 sets the control signal INIT1 to a HI level in response to detecting that the potential has reached the predetermined potential Vdtct. At this time, the potential Vdtct is written to the gate of the drive transistor 120 of the pixel 101, and the writing is completed. The potential of the power supply line 141 continues to rise after time t2 until it reaches the potential VDD. At time t4, when the potential of the power supply line 141 is stabilized at the potential VDD, the vertical synchronization signal and the horizontal synchronization signal are generated by the control circuit 400, and image display is started in the same manner as the operation after time t4 shown in FIG. 5.

[0047] In this way, the drive circuit 200 performs a signal writing operation of writing a non-light-emitting potential to the gate of the drive transistor 120 of the pixel 101 until the detection circuit 500 detects that the potential of the power supply line 141 has reached the predetermined potential Vdtct after the light-emitting device 100 is started. Furthermore, the drive circuit 200 ends the signal writing operation in response to the detection circuit 500 detecting that the potential of the power supply line 141 has reached the predetermined potential Vdtct. As a result, the potential of the signal written to the gate of the drive transistor 120 becomes the same potential as the potential Vdtct detected by the detection circuit 500.

[0048] Here, attention is paid to the period from time t1 when the potential of the power supply line 141 starts to rise to the potential VDD to the start of image display. During the period from time t1 to time t2, the potential of the power supply line 141, which is the same as that of the source of the driving transistor 120, is input to the gate of the driving transistor 120, so that the pixel 101 is in a non-light emitting state. On the other hand, after time t2, the potential of the power supply line 141 changes even after the potential Vdtct is written to the gate of the driving transistor 120 of the pixel 101 at time t2. Therefore, a potential difference (voltage) occurs between the drain and source of the driving transistor 120. Therefore, in this embodiment, the potential Vdtct detected by the detection circuit 500 is set to the above-mentioned non-light emitting potential. As a result, even if the potential of the power supply line 141 changes to the potential VDD after time t2, only a potential difference that puts the pixel 101 in a non-light emitting state (or a level that is not visible, or a level that does not cause discomfort even if light is emitted) occurs between the gate and source of the driving transistor 120. Therefore, during the period from startup to the start of image display, all pixels 101 can be maintained in a non-emitting state.

[0049] 9 to 11, the control signals INIT1 and INIT2 are output by the detection circuit 500 by detecting the potential of the power supply line 141. This can also provide the same effect as the above-mentioned embodiment. In addition, the signal output circuit 300 shown in FIG. 10 is supplied with the potential VDD via the switch 304 to the output node, but this is not limited to this. For example, the signal output circuit 300 may have the configurations shown in FIGS. 6 to 8. In the embodiments described below, the configurations of the signal output circuit 300 and the like may be used in appropriate combination.

[0050] Fig. 12 is a diagram showing a modified example of the light emitting device 100 shown in Fig. 1. The light emitting device 100 shown in Fig. 12 further includes a scanning line 104, compared to the configuration shown in Fig. 1. The following description will focus on configurations that are different from the light emitting device 100 shown in Fig. 1, and descriptions of configurations that may be similar will be omitted as appropriate.

[0051] A driving circuit 200 is connected to the pixels 101 via scanning lines 102 and 104 that are provided in common for each row. The driving circuit 200 is controlled by a control circuit 400, and selects not only a row to which a luminance signal is written from the pixel array 105, but also a row that emits light with a luminance according to the written luminance signal (hereinafter, sometimes referred to as an emission row).

[0052] 13 is a diagram showing a configuration example of a pixel 101 arranged in the light emitting device 100 shown in FIG. 12. The pixel 101 shown in FIG. 13 is different from the configuration shown in FIG. 2 in that it is arranged in a current path including the light emitting element 110 and the driving transistor 120, and further includes a light emission control transistor 122 for controlling the light emission of the light emitting element 110. In this embodiment, the light emission control transistor 122 is arranged between a power supply line 141 that supplies a potential VDD and a node that connects the source of the driving transistor 120 and one terminal of the capacitance element 130. The gate of the light emission control transistor 122 is connected to the scanning line 104, and the light emission control transistor 122 is controlled to be turned on or off by a driving circuit 200.

[0053] FIG. 14 is a diagram showing an example of the configuration of the drive circuit 200 arranged in the light emitting device 100 shown in FIG. 12. The drive circuit 200 shown in FIG. 14 includes a light emission scanning circuit 203, which is different from the configuration shown in FIG. 3. The light emission scanning circuit 203 is provided with an output for each row, and selects the light emission rows in row sequence. The write circuit 202 of the drive circuit 200 controls writing of luminance signals to the pixels 101 and light emission through the scanning lines 102 and 104 based on the output of the scanning circuit 201, the output of the light emission scanning circuit 203, and a control signal INIT1 supplied from the control circuit 400. When the control signal INIT1 is at a HI level, the write circuit 202 of the drive circuit 200 controls write scanning in which the scanning circuit 201 selects a plurality of pixels 101 arranged in the pixel array 105 on a row-by-row basis, and writes luminance signals to the gates of the drive transistors 120 in sequence row-by-row, as described above. At the same time, the write circuit 202 of the drive circuit 200 selects the multiple pixels 101 arranged in the pixel array 105 by row, and turns on the light emission control transistors 122 of the pixels in the selected row to perform light emission control for sequentially causing the light emitting elements 110 to emit light. On the other hand, when the control signal INIT1 is at LO level, the write circuit 202 of the drive circuit 200 performs a signal write operation to write a predetermined signal (for example, potential Vinit) to all the multiple pixels 101 arranged in the pixel array 105 at once, as described above.

[0054] Next, the operation of the light emitting device 100 according to this embodiment in displaying an image will be described. In the pixels 101 that are not selected as either a write row or a light emission row, the write transistor 121 and the light emission control transistor 122 are both in an off state. From this state, the drive circuit 200 controls the pixels 101 in a row-sequential write operation. When the pixel 101 is selected as a write row, a threshold correction operation and a luminance signal write operation are performed. In the threshold correction operation, first, the write transistor 121 of the write row is turned on. At this time, a reference signal that does not depend on the luminance signal is output from the signal output circuit 300 to the signal line 103, and the reference signal is input to the gate of the drive transistor 120 of the write row. Then, the light emission control transistor 122 of the write row is temporarily turned on. When the light emission control transistor 122 is turned on, the source of the drive transistor 120 is connected to the power supply line 141. At this time, the potential difference between the gate and source of the driving transistor 120 becomes equal to or greater than the threshold, and a current flows from the source of the driving transistor 120 through the drain to the light emitting element 110. Next, when the light emission control transistor 122 is turned off, the potential of the source of the driving transistor 120 decreases over time due to the current flowing from the source to the drain. When the potential difference between the drain and the source of the driving transistor 120 becomes approximately the threshold level as the potential of the source of the driving transistor 120 decreases, the fluctuation of the potential of the source of the driving transistor 120 converges. After the potential fluctuation of the source of the driving transistor 120 converges, the writing transistor 121 is turned off, and the threshold voltage of the driving transistor 120 is held in the capacitive element 130. This operation completes the threshold correction operation, and the operation then proceeds to the writing operation of the luminance signal. In this threshold correction operation, a current flows through the light emitting element 110, so that the light emitting element 110 emits light. However, the period of the threshold correction operation is very short compared to one frame period for displaying one image, so that light emission does not become a major problem.

[0055] In a luminance signal write operation, first, the signal output circuit 300 supplies a luminance signal to the signal line 103. Then, the write transistors 121 of the pixels 101 arranged in the row corresponding to the supplied luminance signal are temporarily turned on. Accordingly, the luminance signal is written to the gates of the drive transistors 120 of the pixels 101 in the corresponding row. Next, the write transistors 121 are turned off, completing the write control, and the next row is selected as the write row.

[0056] The row in which the writing of the luminance signal has been completed is selected as an emission row by the drive circuit 200 in the following horizontal period, and the emission is controlled. When selected as an emission row, the emission control transistor 122 is turned on. Accordingly, the potential of the source of the drive transistor 120 becomes the potential VDD supplied to the power supply line 141, and a current corresponding to the luminance signal written from the drive transistor 120 to the light emitting element 110 is supplied, causing the light emitting element 110 to emit light. Next, after a predetermined horizontal period has elapsed, the emission control is completed. When the emission control is completed, the emission control transistor 122 is turned off, and waits in a non-emitting state until the writing control of the next frame.

[0057] During the emission control period, a luminance signal in which the variation in the threshold of the driving transistor 120 for each pixel 101 is reduced by the threshold voltage held in the capacitance element 130 by the threshold correction operation is input to the gate of the driving transistor 120. Therefore, in the configuration of this embodiment, the variation in emission luminance caused by the variation in the threshold of the driving transistor 120 is reduced, and it is possible to display an image with higher uniformity within the display surface of the pixel array 105 than in the above-mentioned embodiment.

[0058] Next, the operation from the start of the light emitting device 100 in this embodiment to the start of image display will be described using an operation timing diagram. Fig. 15 is a timing diagram showing an example of the operation of the light emitting device 100 in this embodiment. For ease of understanding, the number of rows of pixels 101 arranged in the pixel array 105 is illustrated as 8 rows, similar to Figs. 5 and 11.

[0059] At time t0, the light emitting device 100 is powered off. At time t1, the light emitting device 100 is powered on. When the light emitting device 100 is powered on, the control circuit 400 controls both the control signals INIT1 and INIT2 to be at LO level. When the control signals INIT1 and INIT2 are supplied with LO level, the write circuit 202 of the drive circuit 200 supplies a signal to all the scanning lines 102 to turn on the write transistors 121, as described above, to turn on the write transistors 121. In addition, the switch 304 of the signal output circuit 300 (for example, the configuration shown in FIG. 4) is turned on, and the potential Vinit is supplied to the signal line 103. As a result, the write circuit 202 of the drive circuit 200 writes a non-light emitting potential (for example, the potential Vinit) as a predetermined signal collectively to the gates of the drive transistors 120 of all the pixels of the plurality of pixels 101 arranged in the pixel array 105.

[0060] Next, at time t2 and time t3, the control signal INIT1 and the control signal INIT2 are switched to the HI level in turn. After that, from time t4 onwards, the above-mentioned writing control and light emission control are performed row by row starting from the first row, and image display is started.

[0061] In this way, even if the light-emitting control transistor 122 is disposed in the pixel 101, the pixel 101 can be maintained in a non-light-emitting state during the period from when the light-emitting device 100 is turned on to when an image starts to be displayed, as described above. Therefore, the same effect as described above can be obtained in the light-emitting device 100 including the pixel 101 including the light-emitting control transistor 122 in the pixel array 105. Here, during the period from when the light-emitting device 100 is turned on to when an image starts to be displayed, the light-emitting control transistor 122 may be in an on state or an off state.

[0062] In the light-emitting device 100 using an organic EL element, a liquid crystal element, or the like, burn-in of the pixel array 105, which is the display surface, may become a problem. In order to suppress this burn-in, an image may be displayed in a display area formed by pixels arranged in some rows among the multiple pixels 101, and the position of the display area may be shifted at a predetermined timing. Next, a light-emitting device 100 including the pixel 101 including the above-mentioned light-emitting control transistor 122, which has a function of shifting the display area in the row direction while an image is being displayed, will be described.

[0063] FIG. 16 is a diagram showing a configuration example of a drive circuit 200 that shifts a display area. Compared with the configuration shown in FIG. 14, the drive circuit 200 shown in FIG. 16 further includes a display row designation circuit 204 that designates a row on which an image is to be displayed. The scanning circuit 201 selects a write row in row sequence from among the display rows designated by the display row designation circuit 204. Similarly, the light emission scanning circuit 203 selects a light emission row in row sequence from among the display rows designated by the display row designation circuit 204. Here, in this embodiment, both the scanning circuit 201 and the light emission scanning circuit 203 can be configured to include a shift register. By arranging the display row designation circuit 204, the drive circuit 200 is configured to be able to display an image in a display area formed by pixels arranged in some rows among the multiple pixels 101. Furthermore, the drive circuit 200 can shift the position of the display area at a predetermined timing. Here, the predetermined timing for shifting the position of the display area may be, for example, the timing for switching an image between frames. Also, for example, the predetermined timing for shifting the position of the display region may be a timing when an appropriate time has elapsed when a timer or the like is built into the light emitting device 100. Also, for example, the predetermined timing may be a timing when a signal for shifting the position of the display region is input from outside the light emitting device 100.

[0064] The output of the scanning circuit 201 and the output of the light emission scanning circuit 203 are input to the write circuit 202 in the same manner as described above. The write circuit 202 of the drive circuit 200 controls the writing of luminance signals and light emission of the pixels 101 via the scanning lines 102 and 104 based on the output of the scanning circuit 201, the output of the light emission scanning circuit 203, the control signal INIT1 supplied from the control circuit 400, and the output of the display row designation circuit 204. When the control signal INIT1 is at a HI level, the write circuit 202 of the drive circuit 200 controls write scanning in which the scanning circuit 201 selects a plurality of pixels 101 arranged in the pixel array 105 on a row-by-row basis and sequentially writes luminance signals to the gates of the drive transistors 120 for each row. At the same time, the write circuit 202 of the drive circuit 200 performs light emission control by scanning the pixels arranged in the rows of the display area of ​​the plurality of pixels 101 arranged in the pixel array 105 by row by row using the light emission scanning circuit 203, thereby turning on the light emission control transistors 122 of the pixels in the rows included in the display area of ​​the plurality of pixels 101, and sequentially causing the light emitting elements 110 to emit light. At this time, the write circuit 202 of the drive circuit 200 performs non-light emission control to control the pixels 101 arranged in the rows not included in the display area of ​​the plurality of pixels 101 to a non-light emitting state based on the output of the display row designation circuit 204. Here, the non-light emitting control means turning off the light emission control transistors 122 via the scanning line 104. On the other hand, when the control signal INIT1 is at the LO level, a signal write operation is performed to write a predetermined signal (for example, a potential Vinit) to all the pixels of the plurality of pixels 101 arranged in the pixel array 105 at once, as described above.

[0065] Fig. 17 is a timing chart showing an example of the operation of the light emitting device 100 in this embodiment. For ease of understanding, the number of rows of the pixels 101 arranged in the pixel array 105 is illustrated as 8 rows, similarly to Figs. 5, 11, and 15. Also, the number of rows of the display area in which an image is displayed is illustrated as 6 rows.

[0066] During the period from time t0 to time t4, the light emitting device 100 performs the same operation as that shown in FIG. 15 described above. Next, after a predetermined blanking period from time t4, image display is started. Here, assume that the first to sixth rows are designated as rows in the display area for displaying an image during the frame period starting from time t4. In this case, the first to sixth rows are designated by the display row designation circuit 204, and the drive circuit 200 performs writing control and light emission control for the first to sixth rows in row sequence. Meanwhile, the drive circuit 200 performs the non-light emission control described above for the seventh to eighth rows that are outside the display area.

[0067] In this way, even if the light emitting device 100 (drive circuit 200) has a function of shifting the position of the display region, the pixels 101 can be maintained in a non-emitting state during the period from the start of the light emitting device 100 to the start of image display, as described above. Therefore, the same effect as described above can be obtained even in the light emitting device 100 having a function of shifting the position of the display region.

[0068] In addition, in this embodiment, an additional effect described below can be obtained. As described above, after a predetermined blanking period from time t4, image display with the display area set to the first to sixth rows is started. The driving circuit 200 performs writing control and light emission control of the pixels 101 from the first to sixth rows in row sequence in each display frame. Next, assume that the display area is changed to the third to eighth rows in synchronization with a vertical synchronization signal at time t5. At this time, the driving circuit 200 performs non-light emission control on the first and second rows and releases the non-light emission control on the seventh and eighth rows. Accordingly, as shown in FIG. 17, when the sixth row, which is the final display row, is light emission controlled in the final horizontal period of the frame immediately before the display area is changed, the driving circuit 200 continues scanning on the seventh row of the next frame by the internal shift register. Therefore, the pixels 101 that have been changed from the display area to the non-display area are light emission controlled before the desired luminance signal is input.

[0069] Here, as shown in Patent Document 1, it is assumed that, at the start of the light emitting device 100, normal scanning is performed on the pixels 101 arranged in the row of the display area of ​​the pixel array 105, and a black level signal is written to the pixels 101. In that case, a black level signal is written only to six rows out of a total of eight rows arranged in the pixel array 105. Therefore, for the two rows that are not scanned, the potential of the gate of the driving transistor 120 becomes indefinite. Therefore, with a change in the display position, there is a possibility that light will be emitted by the first light emission control from time t5. In contrast, in the light emitting device 100 of this embodiment, a non-light emitting potential can be written to the gate of the driving transistor 120 collectively for all the pixels 101 arranged in the pixel array 105 regardless of the display area. Therefore, in the light emitting device 100 having a function of shifting the position of the display area, light emission accompanying a change in the display area can also be suppressed. In other words, the display quality of the light emitting device 100 is further improved.

[0070] Here, in each of the above-mentioned embodiments, it has been described that the signal writing operation of writing a predetermined signal such as a non-light-emitting potential to the gate of the driving transistor 120 is performed collectively for all pixels of the plurality of pixels 101 during the period from the start of the light-emitting device 100 to the display of an image corresponding to the luminance signal by the write scanning of the scanning circuit 201. However, the signal writing operation is not limited to being performed collectively for all pixels 101. For example, there may be a case where an obstruction is present between the pixel array 105, which is the display surface, and the observer, and the light emitted from the pixels 101 in some rows does not reach the observer. In that case, it is not necessary to perform the signal writing operation of writing a predetermined signal such as a non-light-emitting potential to the gate of the driving transistor 120 for a row of the pixels 101 including a pixel arranged in a row that is difficult to observe from the observer due to the obstruction. Even in that case, it is possible to realize a display that does not feel strange to the observer.

[0071] For example, the driving circuit 200 may perform a signal writing operation of writing a predetermined signal such as a non-light emitting potential to the gates of the driving transistors 120 included in pixels arranged in at least one row or two or more rows of the plurality of pixels 101, without performing scanning using the scanning circuit 201 during the period from the activation of the light emitting device 100 to the start of image display. The row on which the signal writing operation is performed may be set as appropriate depending on the arrangement of the light emitting device 100, the arrangement of the viewer, and the like.

[0072] Here, all of the pixels 101 described above may be pixels that are arranged in the pixel array 105 and emit light to display an image. Monitor pixels used for correcting a luminance signal and the like and so-called dummy pixels that do not emit light when displaying any image and that are arranged, for example, on the outer periphery of the pixel array 105 may not be included in the pixels to which signals are written collectively during the period from when the light emitting device 100 is turned on until an image corresponding to the luminance signal is displayed.

[0073] In addition, consider an additional effect when performing display while shifting the position of the display area. In this case, the light emission of the row that is changed from outside the display area to inside the display area when shifting the image display is more likely to emit light while the observer is observing the image than the light emission caused by the indefinite potential of the gate of the driving transistor 120 before the first image display. In other words, the light emission caused by the indefinite potential of the gate of the driving transistor 120 when the display area is changed may have a significant effect on the display quality of the image in the light emitting device 100. Therefore, for example, consider a case where the display area includes a display area that displays an image first after the start of the light emitting device 100, and a display area that displays an image at a timing later than the display of the image in the first display area. In this case, a signal writing operation may be performed to write a predetermined signal such as a non-light emitting potential to the gate of the driving transistor 120, limited to rows that are not included in the display area where the image is first displayed and are included in the display area at the later timing.

[0074] Here, application examples in which the light emitting device 100 of this embodiment is applied to an image forming device, a display device, a photoelectric conversion device, an electronic device, a lighting device, a mobile object, and a wearable device will be described with reference to Figs. 18(a), 18(b) to 26(a), 26(b). As described above, the light emitting device 100 will be described assuming that an organic light emitting element such as an organic EL element is arranged as the light emitting element 110 in the pixel 101 arranged in the pixel array 105. First, the components arranged in the pixel array 105 of the light emitting device 100 will be described in detail, and then the application examples will be described.

[0075] Structure of organic light-emitting device The organic light-emitting element is provided by forming an insulating layer, a first electrode, an organic compound layer, and a second electrode on a substrate. A protective layer, a color filter, a microlens, etc. may be provided on the cathode. When a color filter is provided, a planarizing layer may be provided between the protective layer and the color filter. The planarizing layer may be made of acrylic resin or the like. The same applies when a planarizing layer is provided between the color filter and the microlens.

[0076] substrate Examples of the substrate include quartz, glass, silicon wafer, resin, and metal. In addition, the substrate may have a switching element such as a transistor, a wiring pattern, and the like, and an insulating layer thereon. The insulating layer may be made of any material as long as it can form a contact hole so that a wiring pattern can be formed between the first electrode and the substrate, and insulation from wiring patterns that are not connected can be ensured. For example, the insulating layer may be made of a resin such as polyimide, silicon oxide, silicon nitride, and the like.

[0077] electrode A pair of electrodes can be used as the electrodes. The pair of electrodes may be an anode and a cathode. When an electric field is applied in the direction in which the organic light-emitting element emits light, the electrode with a higher potential is the anode, and the other is the cathode. It can also be said that the electrode that supplies holes to the light-emitting layer is the anode, and the electrode that supplies electrons is the cathode.

[0078] A material having a large work function may be selected as the material for the anode. For example, a metal such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, or tungsten, a mixture containing these metals, or an alloy of these metals, or a metal oxide such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), or indium zinc oxide may be used. Also, a conductive polymer such as polyaniline, polypyrrole, or polythiophene may be used as the material for the anode.

[0079] These electrode materials may be used alone or in combination of two or more. The anode may be composed of one layer or multiple layers.

[0080] When the electrode is used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or an alloy thereof, or a laminate of these may be used. The above materials may function as a reflective film without serving as an electrode. When a transparent electrode is used as the electrode, a transparent conductive layer of oxide such as indium tin oxide (ITO) or indium zinc oxide may be used, but is not limited to these. Photolithography technology may be used to form the electrode.

[0081] On the other hand, a material with a small work function may be selected as the material for the cathode. For example, an alkali metal such as lithium, an alkaline earth metal such as calcium, an aluminum, titanium, manganese, silver, lead, chromium, or a mixture containing these metals may be used. Alternatively, an alloy combining these metals may be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, zinc-silver, or the like may be used. Metal oxides such as indium tin oxide (ITO) may also be used. One of these electrode materials may be used alone, or two or more may be used in combination. The cathode may have a single layer structure or a multilayer structure. Silver may be used as the cathode, and a silver alloy may be used to reduce the aggregation of silver. As long as the aggregation of silver can be reduced, the ratio of the alloy is not important. For example, silver:other metal may be 1:1, 3:1, or the like.

[0082] The cathode may be a top-emission element using an oxide conductive layer such as ITO, or a bottom-emission element using a reflective electrode such as aluminum (Al), and is not particularly limited. The method for forming the cathode is not particularly limited, but when a direct current or alternating current sputtering method or the like is used, the coverage of the formed film is good and the resistance of the cathode can be reduced.

[0083] Pixel Isolation Layer The pixel separation layer may be formed of so-called silicon oxide such as silicon nitride (SiN), silicon oxynitride (SiON), or silicon oxide (SiO) formed by chemical vapor deposition (CVD). In order to increase the resistance in the in-plane direction of the organic compound layer, the thickness of the organic compound layer, particularly the hole transport layer, may be thinned on the sidewall of the pixel separation layer. Specifically, the thickness of the organic compound layer on the sidewall can be thinned by increasing the taper angle of the sidewall of the pixel separation layer or the thickness of the pixel separation layer to increase vignetting during deposition.

[0084] On the other hand, the sidewall taper angle and film thickness of the pixel separation layer can be adjusted to such an extent that no voids are formed in the protective layer formed thereon. By preventing voids from being formed in the protective layer, the occurrence of defects in the protective layer can be reduced. Since the occurrence of defects in the protective layer is reduced, deterioration in reliability such as the occurrence of dark spots and poor conduction of the second electrode can be reduced.

[0085] According to this embodiment, even if the taper angle of the sidewall of the pixel separation layer is not steep, it is possible to effectively suppress charge leakage to adjacent pixels. As a result of this study, it was found that the charge leakage can be sufficiently reduced if the taper angle is in the range of 60 degrees or more and 90 degrees or less. The thickness of the pixel separation layer may be 10 nm or more to 150 nm or less. The same effect can be obtained even if the pixel electrode is composed only of a pixel electrode without a pixel separation layer. However, in this case, the thickness of the pixel electrode is half or less than that of the organic layer, or the pixel electrode end is forward tapered to less than 60 degrees, thereby reducing short circuits in the organic light-emitting element.

[0086] In addition, even when the first electrode is a cathode and the second electrode is an anode, a wide color gamut and low-voltage operation are possible by forming an electron transport material and a charge transport layer, and also by forming an emitting layer on the charge transport layer.

[0087] organic compound layer The organic compound layer may be formed as a single layer or as multiple layers. When the organic compound layer has multiple layers, it may be called a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, or the like, depending on its function. The organic compound layer is mainly composed of an organic compound, but may contain inorganic atoms or inorganic compounds. The organic compound layer may contain, for example, copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, zinc, or the like. The organic compound layer may be disposed between the first electrode and the second electrode, or may be disposed in contact with the first electrode and the second electrode.

[0088] protective layer A protective layer may be provided on the cathode. For example, by bonding glass provided with a moisture absorbent on the cathode, the intrusion of moisture and the like into the organic compound layer can be reduced, and the occurrence of display defects can be reduced. In another embodiment, a passivation layer such as silicon nitride may be provided on the cathode to reduce the intrusion of moisture and the like into the organic compound layer. For example, after forming the cathode, the cathode may be transported to another chamber without breaking the vacuum, and silicon nitride having a thickness of 2 μm may be formed by a CVD method to form a protective layer. After forming the protective layer by the CVD method, a protective layer may be provided by an atomic deposition (ALD) method. The material of the protective layer by the ALD method is not limited, and may be silicon nitride, silicon oxide, aluminum oxide, or the like. Silicon nitride may be further formed by a CVD method on the protective layer formed by the ALD method. The protective layer formed by the ALD method may have a smaller film thickness than the protective layer formed by the CVD method. Specifically, the film thickness of the protective layer formed by the ALD method may be 50% or less, or even 10% or less, of the film thickness of the protective layer formed by the CVD method.

[0089] Color Filters A color filter may be provided on the protective layer. For example, a color filter taking into consideration the size of the organic light-emitting element may be provided on another substrate, and the substrate on which the color filter is formed and the substrate on which the organic light-emitting element is provided may be bonded together. In addition, for example, a color filter may be patterned on the above-mentioned protective layer using a photolithography technique. The color filter may be made of a polymer.

[0090] planarization layer A planarization layer may be disposed between the color filter and the protective layer. The planarization layer is provided for the purpose of reducing unevenness of the layers below the planarization layer. It may also be called a material resin layer without limiting the purpose. The planarization layer may be composed of an organic compound, and may be a low molecular weight or a high molecular weight compound. In consideration of reducing unevenness, a high molecular weight organic compound may be used for the planarization layer.

[0091] The planarization layer may be provided above and below the color filter. In this case, the constituent materials of each planarization layer may be the same or different. Specifically, the material of the planarization layer may be polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, urea resin, etc.

[0092] Micro Lenses The organic light-emitting device may have an optical member such as a microlens on the light-emitting side. The microlens may be made of acrylic resin, epoxy resin, or the like. The microlens may be intended to increase the amount of light extracted from the organic light-emitting device and control the direction of the extracted light. The microlens may have a hemispherical shape. When the microlens has a hemispherical shape, among the tangents to the hemisphere, there is a tangent that is parallel to the insulating layer, and the tangent and the hemisphere are the vertices of the microlens. The vertex of the microlens can be determined in the same manner in any cross-sectional view. That is, among the tangents to the semicircle of the microlens in the cross-sectional view, there is a tangent that is parallel to the insulating layer, and the tangent and the semicircle are the vertices of the microlens.

[0093] It is also possible to define the midpoint of the microlens. In the cross section of the microlens, a line segment is imaginary from a point where an arc shape ends to a point where another arc shape ends, and the midpoint of the line segment can be called the midpoint of the microlens. The cross section for determining the vertex and midpoint may be a cross section perpendicular to the insulating layer.

[0094] The microlens has a first surface having a convex portion and a second surface opposite to the first surface. The second surface can be disposed closer to the functional layer (light-emitting layer) than the first surface. To adopt such a configuration, it is necessary to form the microlens on the light-emitting device. When the functional layer is an organic layer, a process that becomes high temperature may be avoided in the manufacturing process of the microlens. In addition, when adopting a configuration in which the second surface is disposed closer to the functional layer than the first surface, the glass transition temperatures of all the organic compounds that constitute the organic layer may be 100°C or higher, and it is suitable that the glass transition temperatures are, for example, 130°C or higher.

[0095] Opposing substrate A counter substrate may be disposed on the planarization layer. The counter substrate is called a counter substrate because it is disposed at a position corresponding to the aforementioned substrate. The constituent material of the counter substrate may be the same as that of the aforementioned substrate. When the aforementioned substrate is the first substrate, the counter substrate may be the second substrate.

[0096] organic layer The organic compound layers (hole injection layer, hole transport layer, electron blocking layer, light emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc.) constituting the organic light emitting element according to an embodiment of the present disclosure may be formed by the method described below.

[0097] The organic compound layer constituting the organic light-emitting element according to the embodiment of the present disclosure can be formed by dry processes such as vacuum deposition, ionization deposition, sputtering, plasma, etc. Alternatively to the dry process, a wet process can be used in which a layer is formed by dissolving the compound in an appropriate solvent and applying a known coating method (e.g., spin coating, dipping, casting, LB method, inkjet method, etc.).

[0098] Here, when a layer is formed by a vacuum deposition method or a solution coating method, crystallization is unlikely to occur, and the layer has excellent stability over time. When a layer is formed by a coating method, the layer can be formed by combining with an appropriate binder resin.

[0099] Examples of the binder resin include, but are not limited to, polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0100] These binder resins may be used alone as homopolymers or copolymers, or in combination of two or more. If necessary, known additives such as plasticizers, antioxidants, and ultraviolet absorbers may be used in combination.

[0101] Pixel circuit The light emitting device may have a pixel circuit connected to the light emitting element. The pixel circuit may be an active matrix type that controls the light emission of the first light emitting element and the second light emitting element independently. The active matrix type circuit may be a voltage programming circuit or a current programming circuit. The drive circuit has a pixel circuit for each pixel. The pixel circuit may have a light emitting element, a transistor that controls the light emission luminance of the light emitting element, a transistor that controls the light emission timing, a capacitance that holds the gate voltage of the transistor that controls the light emission luminance, and a transistor for connecting to GND without going through the light emitting element.

[0102] The light-emitting device has a display region and a peripheral region disposed around the display region. The display region has a pixel circuit, and the peripheral region has a display control circuit. The mobility of a transistor constituting the pixel circuit may be smaller than the mobility of a transistor constituting the display control circuit.

[0103] The slope of the current-voltage characteristic of the transistor that constitutes the pixel circuit may be smaller than the slope of the current-voltage characteristic of the transistor that constitutes the display control circuit. The slope of the current-voltage characteristic can be measured by the so-called Vg-Ig characteristic.

[0104] The transistors that make up the pixel circuit are transistors that are connected to a light-emitting element, such as the first light-emitting element.

[0105] Pixels An organic light emitting device includes a plurality of pixels, each of which includes sub-pixels that emit different colors, for example, RGB colors.

[0106] A pixel has an area that emits light, also called a pixel aperture. The pixel aperture may be 15 μm or less, or 5 μm or more. More specifically, it may be 11 μm, 9.5 μm, 7.4 μm, 6.4 μm, etc.

[0107] The spacing between the subpixels may be 10 μm or less, and specifically may be 8 μm, 7.4 μm, or 6.4 μm.

[0108] The pixels may have a known arrangement in plan view. For example, they may be a stripe arrangement, a delta arrangement, a pentile arrangement, or a Bayer arrangement. The shape of the subpixels in plan view may be any known shape. For example, they may be a rectangle, a quadrangle such as a diamond, or a hexagon. Of course, if the shape is not an exact shape but is close to a rectangle, it is included in the rectangle. The shape of the subpixels and the pixel arrangement may be used in combination.

[0109] Uses of the organic light-emitting device according to the embodiment of the present disclosure The organic light-emitting device according to the embodiment of the present disclosure can be used as a component of a display device or a lighting device, and can also be used as an exposure light source for an electrophotographic image forming device, a backlight for a liquid crystal display device, or a light-emitting device having a white light source and a color filter.

[0110] The display device may be an image information processing device having an image input unit that inputs image information from an area CCD, a linear CCD, a memory card, etc., an information processing unit that processes the input information, and displays the input image on the display unit.

[0111] The display unit of the imaging device or inkjet printer may have a touch panel function. The driving method of the touch panel function may be an infrared type, a capacitance type, a resistive film type, or an electromagnetic induction type, and is not particularly limited. The display device may be used in the display unit of a multifunction printer.

[0112] Next, further explanation will be given with reference to the drawings. FIG. 18(a) is an example of a pixel that is a component of the pixel array 105 described above. The pixel has a sub-pixel 810 (pixel 101). The sub-pixels are divided into 810R, 810G, and 810B according to their light emission. The emitted light color may be distinguished by the wavelength emitted from the light-emitting layer, or the light emitted from the sub-pixel may be selectively transmitted or color-converted by a color filter or the like. Each sub-pixel has a reflective electrode 802 as a first electrode on an interlayer insulating layer 801, an insulating layer 803 covering the edge of the reflective electrode 802, an organic compound layer 804 covering the first electrode and the insulating layer, a transparent electrode 805 as a second electrode, a protective layer 806, and a color filter 807.

[0113] A transistor and a capacitor may be disposed below or inside the interlayer insulating layer 801. The transistor and the first electrode may be electrically connected via a contact hole (not shown) or the like.

[0114] The insulating layer 803 may be called a bank or a pixel separation film. The insulating layer 803 covers the edge of the first electrode and is disposed so as to surround the first electrode. The portion of the first electrode where the insulating layer 803 is not disposed contacts the organic compound layer 804 and becomes a light-emitting region.

[0115] The organic compound layer 804 has a hole injection layer 841 , a hole transport layer 842 , a first light emitting layer 843 , a second light emitting layer 844 , and an electron transport layer 845 .

[0116] The second electrode may be a transparent electrode, a reflective electrode, or a semi-transparent electrode.

[0117] The protective layer 806 reduces the penetration of moisture into the organic compound layer. Although the protective layer is illustrated as being a single layer, it may be a multi-layer. Each layer may be an inorganic compound layer and an organic compound layer.

[0118] The color filters 807 are divided into 807R, 807G, and 807B according to their colors. The color filters may be formed on a planarization film (not shown). A resin protective layer (not shown) may be disposed on the color filters. The color filters may be formed on a protective layer 806. The color filters may be provided on an opposing substrate such as a glass substrate and then bonded thereto.

[0119] A display device 800 (corresponding to the above-mentioned light-emitting device 100) in FIG. 18(b) shows an organic light-emitting element 826 and a TFT 818 as an example of a transistor. A substrate 811 such as glass or silicon is provided with an insulating layer 812 on the substrate. An active element such as a TFT 818 is provided on the insulating layer, and a gate electrode 813, a gate insulating film 814, and a semiconductor layer 815 of the active element are provided. The TFT 818 is also composed of a semiconductor layer 815, a drain electrode 816, and a source electrode 817. An insulating film 819 is provided on the upper part of the TFT 818. An anode 821 constituting the organic light-emitting element 826 and a source electrode 817 are connected via a contact hole 820 provided in the insulating film.

[0120] The method of electrical connection between the electrodes (anode, cathode) included in the organic light-emitting element 826 and the electrodes (source electrode, drain electrode) included in the TFT is not limited to the embodiment shown in Fig. 18(b). In other words, it is sufficient that either the anode or the cathode is electrically connected to either the TFT source electrode or the drain electrode. TFT stands for thin film transistor.

[0121] 18(b), the organic compound layer 822 is illustrated as a single layer, but may be a multi-layer organic compound layer 822. A first protective layer 824 and a second protective layer 825 are provided on the cathode 823 to reduce deterioration of the organic light-emitting element.

[0122] In the display device 800 of FIG. 18(b), transistors are used as switching elements, but other switching elements may be used instead.

[0123] Moreover, the transistor used in the display device 800 of Fig. 18(b) is not limited to a transistor using a single crystal silicon wafer, but may be a thin film transistor having an active layer on an insulating surface of a substrate. Examples of the active layer include single crystal silicon, amorphous silicon, non-single crystal silicon such as microcrystalline silicon, and non-single crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Thin film transistors are also called TFT elements.

[0124] The transistors included in the display device 800 of Fig. 18(b) may be formed in a substrate such as a silicon substrate. Here, "formed in a substrate" means that the substrate itself, such as a silicon substrate, is processed to produce the transistors. In other words, having a transistor in a substrate can be seen as the substrate and the transistor being integrally formed.

[0125] The organic light-emitting element according to this embodiment has its light emission brightness controlled by a TFT, which is an example of a switching element, and by providing the organic light-emitting element on a plurality of surfaces, an image can be displayed based on the respective light emission brightnesses. Here, the switching element according to this embodiment is not limited to a TFT, and may be a transistor formed of low-temperature polysilicon, or an active matrix driver formed on a substrate such as a silicon substrate. On a substrate may also be within the substrate. Whether to provide a transistor within the substrate or to use a TFT is selected according to the size of the display unit, and if the size is, for example, about 0.5 inches, the organic light-emitting element may be provided on a silicon substrate.

[0126] 19(a) to 19(c) are schematic diagrams showing an example of an image forming apparatus using the light emitting device 100 of this embodiment. An image forming apparatus 926 shown in Fig. 19(a) includes a photoconductor 927, an exposure light source 928, a developing section 931, a charging section 930, a transfer unit 932, a transport section 933 (the transport roller in the configuration of Fig. 19(a)), and a fixing unit 935.

[0127] Light 929 is irradiated from an exposure light source 928, and an electrostatic latent image is formed on the surface of the photoconductor 927. The light emitting device 100 can be applied to this exposure light source 928. The developing unit 931 contains toner or the like as a developer, and can function as a developing device that applies the developer to the exposed photoconductor 927. The charging unit 930 charges the photoconductor 927. The transfer unit 932 transfers the developed image to a recording medium 934. The transport unit 933 transports the recording medium 934. The recording medium 934 can be, for example, paper or film. The fixing unit 935 fixes the image formed on the recording medium.

[0128] 19(b) and 19(c) are schematic diagrams showing a state in which a plurality of light-emitting sections 936 are arranged on an elongated substrate in the longitudinal direction of an exposure light source 928. A light-emitting device 100 can be applied to the light-emitting section 936. That is, a plurality of pixels 101 arranged on a pixel array 105 are arranged along the longitudinal direction of the substrate. A direction 937 is parallel to the axis of the photoconductor 927. This column direction is the same as the axial direction of the photoconductor 927 when it rotates. This direction 937 can also be called the long axis direction of the photoconductor 927.

[0129] FIG. 19(b) shows a form in which the light-emitting units 936 are arranged along the long axis direction of the photoconductor 927. FIG. 19(c) shows a modified example of the arrangement of the light-emitting units 936 shown in FIG. 19(b), in which the light-emitting units 936 are arranged alternately in the column direction in the first and second columns. The light-emitting units 936 are arranged at different positions in the row direction in the first and second columns. In the first column, a plurality of light-emitting units 936 are arranged at intervals, and in the second column, the light-emitting units 936 are arranged at positions corresponding to the gaps between the light-emitting units 936 in the first column. In addition, a plurality of light-emitting units 936 are also arranged at intervals in the row direction. The arrangement of the light-emitting units 936 shown in FIG. 19(c) can be rephrased as, for example, a state in which the light-emitting units 936 are arranged in a lattice pattern, a state in which the light-emitting units 936 are arranged in a staggered pattern, or a checkerboard pattern.

[0130] FIG. 20 is a schematic diagram showing an example of a display device using the light-emitting device 100 of this embodiment. The 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 FPC1002 and 1004 are connected to the touch panel 1003 and the display panel 1005. An active element such as a transistor is arranged on the circuit board 1007. The battery 1008 does not need to be arranged if the display device 1000 is not a portable device, and even if it is a portable device, it does not need to be arranged at this position. The light-emitting device 100 can be applied to the display panel 1005. The pixels 101 arranged on the pixel array 105 of the light-emitting device 100 functioning as the display panel 1005 are connected to active elements such as transistors arranged on the circuit board 1007 and operate.

[0131] The display device 1000 shown in Fig. 20 may be used as a display unit of a photoelectric conversion device (which may also be called 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 and photoelectrically converts it into an electrical signal. The photoelectric conversion 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 photoelectric conversion device, or may be a display unit disposed within a viewfinder. The photoelectric conversion device may be a digital camera or a digital video camera.

[0132] FIG. 21 is a schematic diagram showing an example of a photoelectric conversion device using the light emitting device 100 of this embodiment. The photoelectric conversion device 1100 may have 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 device 100 of this embodiment can be applied to the viewfinder 1101 and the rear display 1102, which are display units. In this case, the pixel array 105 of the light emitting device 100 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, and the possibility that the subject will be blocked by an obstruction.

[0133] Since the timing suitable for capturing an image is often short, it is better to display information as soon as possible. Therefore, a light emitting device 100 in which pixels 101 including light emitting elements 110 using an organic light emitting material such as an organic EL element are arranged in a pixel array 105 may be used in a viewfinder 1101 or a rear display 1102. This is because organic light emitting materials have a fast response speed. A light emitting device 100 using an organic light emitting material is more suitable than a liquid crystal display device for these devices that require a high display speed.

[0134] The photoelectric conversion device 1100 has an optical section (not shown). The optical section has a plurality of lenses, and forms 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 focal points of the plurality of lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically.

[0135] The light emitting device 100 may be applied to a display unit of an electronic device. In this case, the light emitting device 100 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.

[0136] FIG. 22 is a schematic diagram showing an example of an electronic device using the light-emitting device 100 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 and performs unlocking or the like. A portable device having a communication unit can also be called a communication device. The light-emitting device 100 of this embodiment can be applied to the display unit 1201.

[0137] 23(a) and 23(b) are schematic diagrams showing an example of a display device using the light emitting device 100 of this embodiment. FIG. 23(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 100 of this 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. 23(a). For example, the lower side 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.

[0138] FIG. 23(b) is a schematic diagram showing another example of a display device using the light-emitting device 100 of the present embodiment. The display device 1310 of FIG. 23(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 device 100 of the present 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 one display unit without a joint. The first display unit 1311 and the second display unit 1312 can be separated at the bending point. The first display unit 1311 and the second display unit 1312 may display different images, or the first display unit and the second display unit may display one image.

[0139] FIG. 24 is a schematic diagram showing an example of an illumination device using the light emitting device 100 of the present embodiment. The illumination device 1400 may have a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404, and a light diffusion unit 1405. The light emitting device 100 of the present 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 the light of the light source, such as for lighting up, and deliver the light to a wide range. If necessary, a cover may be provided on the outermost part. The illumination device 1400 may have both the optical film 1404 and the light diffusion unit 1405, or only one of them.

[0140] The lighting device 1400 is, for example, a device that illuminates a room. The lighting device 1400 may emit white light, neutral white light, 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 device 100 that functions as the light source 1402. The power supply circuit is a circuit that converts AC voltage to DC voltage. Moreover, white has a color temperature of 4200K, and neutral white has a color temperature of 5000K. Moreover, the lighting device 1400 may have a color filter. Moreover, the lighting device 1400 may have a heat dissipation unit. The heat dissipation unit dissipates heat inside the device to the outside of the device, and examples of the heat dissipation unit include metals with high specific heat and liquid silicon.

[0141] FIG. 25 is a schematic diagram of an automobile having a tail lamp, which is an example of a vehicle lamp using the light emitting device 100 of this embodiment. The automobile 1500 may have a tail lamp 1501, and may be configured to turn on the tail lamp 1501 when braking or the like is performed. The light emitting device 100 of this embodiment may be used as a head lamp as a vehicle lamp. An automobile is an example of a moving body, and the moving body may be a ship, a drone, an aircraft, a railroad car, an industrial robot, or the like. The moving body may have a machine body and a lamp provided thereon. The lamp may indicate the current position of the machine body.

[0142] The light emitting device 100 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 device 100 functioning as the tail lamp 1501. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, and may be made of polycarbonate or the like. The protective member may be made by mixing a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like with polycarbonate.

[0143] The automobile 1500 may have a body 1503 and a window 1502 attached thereto. The window may be a window for checking the front and rear of the automobile, or may be a transparent display such as a head-up display. The light emitting device 100 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 device 100 are made of transparent members.

[0144] 26(a) and 26(b), a further application example of the light emitting device 100 of the present embodiment will be described. The light emitting device 100 can be applied to a system that can be worn as a wearable device, such as smart glasses, a head mounted display (HMD), or smart contacts. An image capturing and displaying device used in such an application example has an image capturing device capable of photoelectrically converting visible light, and a light emitting device capable of emitting visible light.

[0145] 26(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. In addition, the light emitting device 100 of this embodiment is provided on the back side of the lens 1601.

[0146] 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 device 100 according to each embodiment. The control device 1603 also controls the operations of the image capture device 1602 and the light emitting device 100. The lens 1601 is formed with an optical system for focusing light on the image capture device 1602.

[0147] FIG. 26(b) illustrates glasses 1610 (smart glasses) according to one application example. The glasses 1610 have a control device 1612, and an imaging device corresponding to the imaging device 1602 and a light emitting device 100 are mounted on the control device 1612. An optical system for projecting light emitted from the imaging device in the control device 1612 and the light emitting device 100 is formed in the lens 1611, 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 light emitting device 100, and controls the operation of the imaging device and the light emitting device 100. The control device 1612 may have a line of sight detection unit that detects the line of sight of the wearer. Infrared light may be used to detect the line of sight. The infrared light emission unit emits infrared light toward the eyeball of a user gazing at a display image. An imaging unit having a light receiving element detects the reflected light of the emitted infrared light from the eyeball, thereby obtaining an image of the eyeball. By providing a reduction unit that reduces the amount of light from the infrared light emitting unit to the display unit in a plan view, degradation of image quality is reduced.

[0148] The gaze of the user with respect to the displayed image is detected from an image of the eyeball obtained by capturing infrared light. Any known method can be applied to gaze detection using the image of the eyeball. As an example, a gaze detection method based on a Purkinje image formed by reflection of irradiated light on the cornea can be used.

[0149] More specifically, a gaze detection process based on the pupil-corneal reflex method is performed. Using the pupil-corneal reflex method, a gaze vector that indicates the direction (rotation angle) of the eyeball is calculated based on the pupil image and the Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0150] The light emitting device 100 according to the embodiment of the present disclosure may include an imaging device having a light receiving element, and may control a display image based on user line-of-sight information from the imaging device.

[0151] Specifically, the light emitting device 100 determines a first field of view area to which the user gazes and a second field of view area other than the first field of view area based on line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the light emitting device 100, or may be received from an external control device. In the display area of ​​the light emitting device 100, 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.

[0152] The display area includes a first display area and a second display area different from the first display area, and an area having a high priority 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 100, or may be determined by an external control device and received. The resolution of the area having a high priority may be controlled to be higher than the resolution of areas other than the area having a high priority. In other words, the resolution of an area having a relatively low priority may be lowered.

[0153] 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 the line of sight and the distance to an object at the end of the line of sight from the image of the eyeball, using as teacher 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 light-emitting device 100, the imaging device, or an external device. If included in an external device, it is transmitted to the light-emitting device 100 via communication.

[0154] When display control is performed based on visual recognition detection, the present invention is preferably applicable to smart glasses that further include an imaging device for capturing images of the outside world. The smart glasses can display captured outside information in real time.

[0155] The disclosure of this specification includes the following light-emitting device, display device, photoelectric conversion device, electronic device, lighting device, and mobile object.

[0156] (Item 1) a plurality of pixels each including a light emitting element and a drive transistor for supplying a current to the light emitting element in accordance with a luminance signal, the pixels being arranged to form a plurality of rows and a plurality of columns; a drive circuit including a scanning circuit that scans the plurality of pixels row by row and performs write scanning to write the luminance signal to the gate of the drive transistor; A light emitting device comprising: The light-emitting device is characterized in that the drive circuit performs a signal writing operation to write a predetermined signal simultaneously to the gates of the drive transistors included in pixels arranged in two or more rows among the plurality of pixels between the start-up of the light-emitting device and the start of the write scanning.

[0157] (Item 2) The predetermined signal is a signal that the luminance of the light-emitting element is 0.1 cd / m 2 or a signal that causes the luminance of the light-emitting element to be equal to or lower than a black level in the luminance signal.

[0158] (Item 3) a signal output circuit for supplying the luminance signal via a signal line arranged corresponding to pixels arranged in a column direction among the plurality of pixels; Each of the plurality of pixels further includes a write transistor disposed between the gate of the drive transistor and the signal line; The light-emitting device described in item 1 or 2, characterized in that during the period from when the light-emitting device is turned on to when the write scan begins, the signal output circuit supplies the specified signal to the signal line, and the drive circuit turns on the write transistor, thereby writing the specified signal to the gate of the drive transistor.

[0159] (Item 4) The light-emitting device according to claim 3, characterized in that, after the specified signal is written to the gate of the drive transistor and before the signal supplied from the signal output circuit to the signal line changes from the specified signal, between the start-up of the light-emitting device and the start of the write scan, the drive circuit turns off the write transistor.

[0160] (Item 5) the signal output circuit includes a driver circuit that outputs the luminance signal to the signal line; the predetermined signal is supplied to an output node of the driver circuit via a switch; 5. The light emitting device according to item 3 or 4, wherein the switch is turned on during the period from when the light emitting device is turned on until when the write scan is started.

[0161] (Item 6) the signal output circuit includes a driver circuit that outputs the luminance signal to the signal line; The predetermined signal is supplied to an input node of the driver circuit via a switch; 5. The light emitting device according to item 3 or 4, wherein the switch is turned on during the period from when the light emitting device is turned on until when the write scan is started.

[0162] (Item 7) the signal output circuit includes a driver circuit that outputs the luminance signal to the signal line; 5. The light emitting device according to item 3 or 4, wherein the driver circuit is configured to be capable of selectively outputting the luminance signal and the predetermined signal.

[0163] (Item 8) a signal output circuit for supplying the luminance signal via a first signal line arranged corresponding to pixels arranged in a column direction among the plurality of pixels, and a second signal line to which the predetermined signal is supplied, Each of the plurality of pixels further includes a first write transistor arranged between the gate of the driving transistor and the first signal line, and a second write transistor arranged between the gate of the driving transistor and the second signal line, The light-emitting device described in item 1 or 2, characterized in that, between the start-up of the light-emitting device and the start of the write scan, the drive circuit turns on the second write transistor, thereby writing the specified signal to the gate of the drive transistor.

[0164] (Item 9) the drive circuit is configured to be capable of displaying an image in a display area constituted by pixels arranged in some rows of the plurality of pixels, and shifts a position of the display area at a predetermined timing; the display area includes a first display area that displays an image first after the light-emitting device is turned on, and a second display area that displays an image at a timing later than the display of the image in the first display area, 9. The light emitting device according to any one of items 1 to 8, wherein the two or more rows include a row that is not included in the first display area and is included in the second display area.

[0165] (Item 10) Each of the plurality of pixels further includes a light emission control transistor that is disposed in a current path including the light emitting element and the driving transistor and controls light emission of the light emitting element; The light-emitting device described in item 9, characterized in that the drive circuit further includes an emission scanning circuit that turns on the emission control transistors of pixels in a row of the plurality of pixels included in the display area by scanning pixels arranged in a row of the display area among the plurality of pixels on a row-by-row basis.

[0166] (Item 11) 11. The light emitting device according to item 10, wherein the scanning circuit and the light emission scanning circuit each include a shift register.

[0167] (Item 12) 12. The light emitting device according to any one of items 1 to 11, wherein the drive circuit performs the signal writing operation in response to activation of the light emitting device.

[0168] (Item 13) a current path including the light emitting element and the driving transistor is disposed between a first power supply line that supplies a first potential and a second power supply line that supplies a second potential that is lower than the first potential; 13. The light emitting device according to any one of items 1 to 12, wherein the potential of the predetermined signal is the same as the first potential.

[0169] (Item 14) a current path including the light emitting element and the driving transistor is disposed between a first power supply line that supplies a first potential and a second power supply line that supplies a second potential that is lower than the first potential; a detection circuit for detecting a potential of the first power supply line; The light-emitting device described in any one of items 1 to 12, characterized in that the drive circuit performs the signal writing operation after the light-emitting device is started up until the detection circuit detects that the potential of the first power supply line has reached a predetermined potential, and terminates the signal writing operation in response to the detection circuit detecting that the potential of the first power supply line has reached the predetermined potential.

[0170] (Item 15) 15. The light emitting device according to item 14, wherein the potential of the predetermined signal is the same as the predetermined potential.

[0171] (Item 16) 16. The light emitting device according to any one of items 1 to 15, wherein the drive circuit performs the signal writing operation collectively for all of the plurality of pixels.

[0172] (Item 17) a plurality of pixels each including a light emitting element and a drive transistor for supplying a current to the light emitting element in accordance with a luminance signal, the pixels being arranged to form a plurality of rows and a plurality of columns; a drive circuit including a scanning circuit that scans the plurality of pixels row by row and performs write scanning to write the luminance signal to the gate of the drive transistor; A light emitting device comprising: The light-emitting device, further comprising a write circuit that performs a signal write operation to write a predetermined signal to the gate of the drive transistor included in a pixel arranged in at least one row among the plurality of pixels, without performing scanning using the scanning circuit between the start of the light-emitting device and the start of the write scan.

[0173] (Item 18) 18. A display device comprising: a light-emitting device according to any one of items 1 to 17; and an active element connected to the light-emitting device.

[0174] (Item 19) 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, 18. A photoelectric conversion device, wherein the display unit displays an image captured by the imaging element, and the photoelectric conversion device has the light-emitting device according to any one of items 1 to 17.

[0175] (Item 20) A display device having a housing and a communication unit provided in the housing for communicating with an external device, 18. An electronic device, wherein the display unit comprises the light-emitting device according to any one of items 1 to 17.

[0176] (Item 21) A lighting device having a light source and at least one of a light diffusion unit and an optical film, 18. An illumination device, wherein the light source comprises the light emitting device according to any one of items 1 to 17.

[0177] (Item 22) A moving body having a body and a lighting device provided on the body, The lighting device is a moving body having the light emitting device according to any one of items 1 to 17.

[0178] The invention is not limited to the above-described embodiments, and various modifications and variations are possible 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]

[0179] 100: Light emitting device, 101: Pixel, 110: Light emitting element, 120: Driving transistor, 200: Driving circuit, 201: Scanning circuit

Claims

1. a plurality of pixels arranged in a plurality of rows and a plurality of columns, each including a light emitting element and a drive transistor for supplying a current to the light emitting element in accordance with a luminance signal; a drive circuit including a scanning circuit that scans the plurality of pixels row by row and performs write scanning to write the luminance signal to the gate of the drive transistor; A light emitting device comprising: The light-emitting device is characterized in that the drive circuit performs a signal writing operation to write a predetermined signal simultaneously to the gates of the drive transistors included in pixels arranged in two or more rows of the plurality of pixels only between the start of the light-emitting device and the start of the first write scan.

2. The predetermined signal is a signal that the luminance of the light-emitting element is 0.1 cd / m ２ 2. The light emitting device according to claim 1, wherein the luminance signal is a signal that causes the luminance of the light emitting element to be equal to or lower than a black level of the luminance signal.

3. a signal output circuit for supplying the luminance signal via a signal line arranged corresponding to pixels arranged in a column direction among the plurality of pixels; each of the plurality of pixels further includes a write transistor disposed between the gate of the drive transistor and the signal line; 2. The light-emitting device according to claim 1, wherein, during the period from when the light-emitting device is turned on to when the first write scan is started, the signal output circuit supplies the predetermined signal to the signal line, and the drive circuit turns on the write transistor, thereby writing the predetermined signal to the gate of the drive transistor.

4. The light-emitting device according to claim 3, characterized in that, after the predetermined signal is written to the gate of the drive transistor and before the signal supplied from the signal output circuit to the signal line changes from the predetermined signal, the drive circuit turns off the write transistor between the start of the light-emitting device and the start of the first write scan.

5. the signal output circuit includes a driver circuit that outputs the luminance signal to the signal line; the predetermined signal is supplied to an output node of the driver circuit via a switch; 4. The light emitting device according to claim 3, wherein the switch is turned on during a period from when the light emitting device is turned on until the first write scan is started.

6. the signal output circuit includes a driver circuit that outputs the luminance signal to the signal line; the predetermined signal is supplied to an input node of the driver circuit via a switch; 4. The light emitting device according to claim 3, wherein the switch is turned on during a period from when the light emitting device is turned on until the first write scan is started.

7. the signal output circuit includes a driver circuit that outputs the luminance signal to the signal line; 4. The light emitting device according to claim 3, wherein the driver circuit is configured to be able to selectively output the luminance signal and the predetermined signal.

8. a signal output circuit for supplying the luminance signal via a first signal line arranged corresponding to pixels arranged in a column direction among the plurality of pixels, and a second signal line to which the predetermined signal is supplied, each of the plurality of pixels further includes a first write transistor arranged between the gate of the drive transistor and the first signal line, and a second write transistor arranged between the gate of the drive transistor and the second signal line; 2. The light-emitting device according to claim 1, wherein the drive circuit writes the predetermined signal to the gate of the drive transistor by turning on the second write transistor during the period from when the light-emitting device is turned on to when the first write scan is started.

9. the drive circuit is configured to be able to display an image in a display area formed by pixels arranged in some rows of the plurality of pixels, and shifts the position of the display area at a predetermined timing; the display area includes a first display area that displays an image first after activation of the light-emitting device, and a second display area that displays an image at a timing later than the display of the image in the first display area, The light emitting device according to claim 1 , wherein the two or more rows include a row that is not included in the first display area and is included in the second display area.

10. each of the plurality of pixels further includes a light-emitting control transistor that is arranged in a current path including the light-emitting element and the drive transistor and that controls light emission of the light-emitting element; 10. The light-emitting device according to claim 9, wherein the drive circuit further includes a light-emission scanning circuit that turns on the light-emission control transistors of the pixels in the rows included in the display area among the plurality of pixels by scanning the pixels arranged in the rows of the display area among the plurality of pixels row by row.

11. 11. The light emitting device according to claim 10, wherein the scanning circuit and the light emission scanning circuit each include a shift register.

12. 2. The light emitting device according to claim 1, wherein the drive circuit performs the signal writing operation in response to activation of the light emitting device.

13. a current path including the light emitting element and the driving transistor is arranged between a first power supply line that supplies a first potential and a second power supply line that supplies a second potential that is lower than the first potential; 2. The light emitting device according to claim 1, wherein the potential of the predetermined signal is the same as the first potential.

14. a current path including the light emitting element and the driving transistor is arranged between a first power supply line that supplies a first potential and a second power supply line that supplies a second potential that is lower than the first potential; further comprising a detection circuit that detects the potential of the first power supply line; The light-emitting device described in claim 1, characterized in that the drive circuit performs the signal writing operation after the light-emitting device is started up until the detection circuit detects that the potential of the first power supply line has reached a predetermined potential, and terminates the signal writing operation in response to the detection circuit detecting that the potential of the first power supply line has reached the predetermined potential.

15. 15. The light emitting device according to claim 14, wherein the potential of the predetermined signal is the same as the predetermined potential.

16. 2. The light emitting device according to claim 1, wherein the drive circuit performs the signal writing operation collectively on all of the plurality of pixels.

17. a plurality of pixels arranged in a plurality of rows and a plurality of columns, each including a light emitting element and a drive transistor for supplying a current to the light emitting element in accordance with a luminance signal; a drive circuit including a scanning circuit that scans the plurality of pixels row by row and performs write scanning to write the luminance signal to the gate of the drive transistor; A light emitting device comprising: The light-emitting device is characterized in that the drive circuit further includes a write circuit that performs a signal write operation to write a predetermined signal to the gate of the drive transistor included in a pixel arranged in at least one row of the plurality of pixels, without performing scanning using the scanning circuit, only during the period from the start of the light-emitting device to the start of the first write scan.

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

19. an optical unit having a plurality of lenses, an image sensor that receives light that has passed through the optical unit, and a display unit that displays an image; A photoelectric conversion device, wherein the display section displays an image captured by the imaging element, and the photoelectric conversion device comprises the light-emitting device according to claim 1 .

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

18. An electronic device, wherein the display unit comprises the light-emitting device according to claim 1.

21. A lighting device having a light source and at least one of a light diffusion unit and an optical film, 18. An illumination device, characterized in that the light source comprises a light emitting device according to any one of claims 1 to 17.

22. A moving body having a body and a lighting fixture provided on the body, 18. A moving body, wherein the lighting fixture comprises the light emitting device according to claim 1.

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