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

Abstract

To provide a technique advantageous for prevention of light emission unevenness.SOLUTION: A light emitting device includes: a plurality of pixels that are arranged to form rows and columns, and each include a luminous element; a drive circuit that writes signal values according to light emission luminance in the plurality of pixels; and a signal processing circuit. The signal processing circuit selects pixels in a first group that is constituted by pixels having signal values exceeding a predetermined threshold, of the plurality of pixels, and pixels in a second group that is constituted by pixels having signal values equal to or less than the predetermined threshold, of the plurality of pixels. The drive circuit writes the signal values in the pixels included in the first group in a first period, and writes signals in the pixels included in the second group in a second period different from the first period.SELECTED DRAWING: Figure 2

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 body.

Background Art

[0002] Patent Document 1 discloses a display device that provides a light detection element in proximity to each light-emitting element arranged on a display surface and performs luminance correction of the light-emitting element while an image is being displayed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the current flowing through a common power line to a plurality of light-emitting elements fluctuates during the operation of the light-emitting device, the potential of the power line may temporarily fluctuate. If the luminance signal is written while the potential of the power line is fluctuating, the signal value written to the light-emitting element may be affected by the fluctuation of the potential of the power line and fluctuate, which may cause uneven light emission or the like. In the operation shown in Patent Document 1, there is a possibility that it may not be possible to cope with a temporary potential fluctuation of the power line.

[0005] An object of the present invention is to provide a technique advantageous for suppressing uneven light emission.

Means for Solving the Problems

[0006] In view of the above problems, a light-emitting device according to an aspect of the present disclosure includes a plurality of pixels each including a light-emitting element and arranged to form rows and columns, a driving circuit that writes a signal value corresponding to the light-emitting luminance to each of the plurality of pixels, and a signal processing circuit. The signal processing circuit selects a first group of pixels composed of pixels among the plurality of pixels whose signal values exceed a predetermined threshold value, and a second group of pixels composed of pixels among the plurality of pixels whose signal values are equal to or less than the predetermined threshold value. The driving circuit writes a signal value to the pixels included in the first group in a first period, and writes a signal to the pixels included in the second group in a second period different from the first period.

Effects of the Invention

[0007] According to the present invention, it is possible to provide a technique advantageous for suppressing light emission unevenness.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

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Figure 10

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Figure 12

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Figure 15

Figure 16

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, not all of these plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant descriptions are omitted.

[0010] With reference to FIGS. 1 to 7, a light-emitting device according to an embodiment of the present disclosure will be described. The following embodiments are all examples of the present disclosure, and numerical values, shapes, materials, arrangements of components, etc. do not limit the present disclosure.

[0011] FIG. 1 is a block diagram showing a configuration example of a light-emitting device 100 according to the present embodiment. The light-emitting device 100 includes a plurality of pixels 200, a driving circuit 111 that writes a signal value corresponding to the emission luminance to each of the plurality of pixels 200, and a signal processing circuit 102. As shown in FIG. 1, the driving circuit 111 may include a column selection circuit 104, a column memory 105, a timing signal generator 106, a column digital-to-analog converter (DAC) 107, a column buffer 108, and a row selection circuit 109. Further, the light-emitting device 100 may further include a reception circuit 101 and a memory 103.

[0012] The light-emitting device 100 is a device that performs display such as a desired image in a pixel region 110 including a plurality of pixels 200. The plurality of pixels 200 each include a light-emitting element 205 (shown in FIG. 3), and are arranged in the pixel region 110 so as to form rows and columns.

[0013] The receiving circuit 101 receives display data supplied from outside the light-emitting device 100 for display in the pixel region 110. The display data received by the receiving circuit 101 is supplied to the signal processing circuit 102. The memory 103 is connected to the signal processing circuit 102. The memory 103 is a memory area for temporarily storing the display data supplied from outside.

[0014] The signal processing circuit 102 performs processing for display in the pixel region 110 on the display data. The signal processing circuit 102 selects the plurality of pixels 200 into a group 151 of pixels constituted by pixels whose signal values corresponding to the light-emitting luminance exceed a predetermined threshold value, and a group 152 of pixels constituted by pixels whose signal values among the plurality of pixels 200 are equal to or less than the predetermined threshold value. For example, the signal processing circuit 102 selects between the pixels 200 of the group 151 and the pixels 200 of the group 152 based on the signal value of each pixel 200 included in the display data held in the memory 103. The signal processing circuit 102 supplies drive data of the pixels 200 selected for each of the groups 151 and 152 to the drive circuit 111.

[0015] The signal processing circuit 102 transfers column drive data to the column selection circuit 104 and signal value data to the column memory 105 as drive data. The column drive data and the signal value data can be data for each pixel row in the pixel region 110 including the plurality of pixels 200. Further, the signal processing circuit 102 sends a timing control signal for controlling the operation timing in the drive circuit 111 to the timing signal generator 106.

[0016] The column selection circuit 104 that receives the supply of column drive data generates a signal for selecting pixels 200 in a predetermined column for each pixel row. Further, among the signal value data supplied to the column memory 105, the column selection circuit 104 causes the column DAC 107 to supply the data of the signal values corresponding to each of the selected pixels 200 in the column (hereinafter sometimes referred to as column data). Here, although it is described that a part of the signal value data supplied to the column memory 105 is selected and supplied to the column DAC 107, all of the signal value data supplied to the column memory 105 may be supplied to the column DAC 107 for each pixel row.

[0017] The column DAC 107 digitally-analog converts the signal values of the column data supplied from the column memory 105 according to the timing signal input from the timing signal generator 106. The signal values of the column data converted from digital values to analog values by the column DAC 107 are supplied to the pixel region 110 via the column buffer 108. At this time, by the timing signal generator 106 supplying a timing signal to the row selection circuit 109, the row selection circuit 109 can generate a row selection signal synchronized with the column data. The row selection of the plurality of pixels 200 arranged in a matrix is executed at any time. By sequentially selecting the rows and columns respectively, a signal value corresponding to the emission luminance is written into the pixel 200.

[0018] FIG. 2 shows an example of display data. In the pixel region 110, a plurality of pixels 200 of n rows (n is an integer of 2 or more) × m columns (m is an integer of 2 or more) are arranged. In FIG. 2, a state in which the pixels 200 are grouped based on the display data in the period of one frame for displaying one image is shown. As described above, the signal processing circuit 102 groups each of the pixels 200 according to whether the signal value exceeds a threshold value. In FIG. 2, the pixels 200 shown hatched are the pixels of the group 151 composed of the pixels whose signal values exceed a predetermined threshold value, and the pixels 200 shown in white are the pixels of the group 152 composed of the pixels whose signal values are below the predetermined threshold value. Each pixel 200 is driven according to the signal HS(m), the signal Din(m), which are supplied from the column selection circuit 104 and the column memory 105 via the column DAC 107 and the column buffer 108, and the signal VS(n) supplied from the row selection circuit 109. The signal HS(m) is a signal for selecting the column to which the signal value is written, generated by the column selection circuit 104. The signal Din(m) is the signal value data (signal value) supplied from the column memory 105 via the column DAC 107 and the column buffer 108. The signal VS(n) is a signal for selecting the row to which the signal value is written, supplied from the row selection circuit 109. Here, m and n are each an integer of 2 or more as described above, and in the following description, an example in which each is 8 is shown.

[0019] FIG. 3 is a circuit diagram showing a configuration example of the pixel 200 arranged in the pixel region 110. The pixel 200 includes a row selection transistor 201, a column selection transistor 202, a holding capacitor 203 for holding the written signal value, a driving transistor 204, and a light emitting element 205. In the configuration shown in FIG. 3, the row selection transistor 201, the column selection transistor 202, and the driving transistor 204 are shown as P-channel type transistors, but it is not limited thereto, and any appropriate configuration may be used as long as it is not limited to transistors.

[0020] The signal VS(n) is supplied to the gate of the row selection transistor 201. The signal HS(m) is supplied to the gate of the column selection transistor 202. One main terminal of the row selection transistor 201 (the drain in the configuration of FIG. 3.) is connected to the signal line to which the signal Din(m) is supplied, and the other main terminal (the source in the configuration of FIG. 3.) is connected to one main terminal of the column selection transistor 202 (the drain in the configuration of FIG. 3.). The other main terminal of the column selection transistor 202 (the source in the configuration of FIG. 3.) is connected between one terminal of the holding capacitor 203 and the gate of the drive transistor 204. In the configuration shown in FIG. 3, the column selection transistor 202 is arranged between the row selection transistor 201 and the drive transistor 204, but the row selection transistor 201 may be arranged between the column selection transistor 202 and the drive transistor 204. The other terminal of the holding capacitor 203 is connected to a signal line of a predetermined potential such as a predetermined potential line (e.g., VDD line, etc.) or a GND line.

[0021] One of the main terminals of the driving transistor 204 (source in the configuration of FIG. 3) is directly or indirectly connected to one of the electrodes of the light-emitting element 205 (anode in the configuration of FIG. 3). Here, the expression "indirectly" means that another element is arranged between the driving transistor 204 and the light-emitting element 205. Also, the other main terminal of the driving transistor 204 (drain in the configuration of FIG. 3) is directly or indirectly connected to the potential line. The other electrode of the light-emitting element 205 (cathode in the configuration of FIG. 3) is connected to the GND line. Here, although the driving transistor 204 is described as a P-channel type transistor, it may be an N-channel type transistor. In that case, the connection relationship between the potential line and the GND line may be reversed. When both the row selection transistor 201 and the column selection transistor 202 are selected, the signal value of the signal Din(m) is written into the holding capacitor 203, and the gate-source voltage of the driving transistor 204 changes according to the signal value. By flowing a driving current corresponding to the gate-source voltage of the driving transistor 204 through the light-emitting element 205, the light-emitting element 205 emits light with a luminance corresponding to the signal value.

[0022] FIG. 4 is a timing diagram showing a specific operation example of the light-emitting device 100 in the present embodiment. The operation shown in FIG. 4 will be described assuming that the pixels at the 2nd, 3rd, and 5th columns in the 3rd row, the pixel at the 4th column in the 4th row, the pixels at the 5th and 6th columns in the 5th row, the pixels at the 2nd and 6th columns in the 6th row, and the pixel at the 7th column in the 7th row among the pixels 200 arranged in the pixel region 110 as shown in FIG. 2 each constitute the pixels of group 151, and the other pixels constitute the pixels of group 152. Here, as described above, an example where n of the signal VS(n) is 8 and m of the signal HS(m) is 8 is shown, but n and m may be integers of 2 or more. Also, in FIG. 4, it is assumed that the time elapses from left to right with the horizontal axis representing time. The signal selection with respect to this time elapse is an example, and the order of selection is not limited.

[0023] When the signal VS(1) becomes low level at time t1, until the signal VS(1) returns to high level at time t2, the row selection transistor 201 in the first row is in the ON (conductive) state, and the pixels 200 in the first row are each selected. During the period from time t1 to time t2, since all the signals HS(m) are at high level, the column selection transistor 202 is not in the ON state, and no new signal is written to the holding capacitor 203. Similarly, during the period from time t2 to time t3, the signal VS(2) becomes low level, and the row selection transistor 201 in the second row is in the ON (conductive) state. The pixels 200 in the second row are selected, but all the signals HS(m) are at high level, and no signal value is written. This is because, as shown in FIG. 2, the pixels 200 constituting the group 151 are not arranged in the pixel rows of the first and second rows.

[0024] Next, at time t3, the signal VS(3) becomes low level, and the pixels 200 in the third row are selected until time t4. At this time, the signals HS(2), HS(3), HS(5) become low level, the column selection transistors 202 arranged in the 2nd, 3rd, and 5th columns transition to the ON state, and the signal values are written to the holding capacitors 203 of the pixels 200 in the 2nd, 3rd, and 5th columns of the selected third row. When the signal value of the holding capacitor 203 is rewritten, the gate potential of the drive transistor 204 changes, the current flowing through the light-emitting element 205 changes, and the luminance of the light-emitting element 205 changes. In this way, since the drive circuit 111 (the column selection circuit 104, the column memory 105, the timing signal generator 106, the column DAC 107, the column buffer 108, and the row selection circuit 109 cooperate to operate, it may simply be indicated as the drive circuit 111.) writes the signal value to the pixels 200 included in the group 151 during the period 121.

[0025] The period of one frame for writing signal values for displaying one image based on one display data to each pixel 200 includes the above-described period 121 in which the drive circuit 111 writes signal values to the pixels 200 included in the group 151, and a period 122 in which the drive circuit 111 writes signal values to the pixels 200 included in the group 152. The period 121 and the period 122 are different from each other. In the operation example shown in FIG. 4, in the period 121, the drive circuit 111 sequentially selects a plurality of pixels 200 row by row (signal VS(n)), and writes a signal value (signal Din(m)) to the pixels 200 arranged in the selected pixel row among the pixels 200 of the group 151 (signal HS(m)). Next, in the period 122, the drive circuit 111 sequentially selects a plurality of pixels 200 row by row (signal VS(n)), and writes a signal value (signal Din(m)) to the pixels 200 arranged in the selected pixel row among the pixels 200 of the group 152 (signal HS(m)).

[0026] As described above, the signal processing circuit 102 selects a plurality of pixels 200 into the pixels 200 that constitute the group 151 and the pixels 200 that constitute the group 152. After the selection, the signal processing circuit 102 supplies, for each pixel row, column drive data indicating the columns in which the respective groups 151 and 152 are arranged to the column selection circuit 104. Further, the signal processing circuit 102 transfers, for example, the signal value data stored in the memory 103 to the column memory 105 for each pixel row. The column drive data indicating the columns in which the pixels 200 included in the selected groups 151 and 152 are arranged may be stored in the memory 103 once, for example. Thereafter, for example, the column drive data may be read by the signal processing circuit 102 for each pixel row and supplied to the column selection circuit 104. Thereby, the operation shown in FIG. 4 can be realized. For example, the signal processing circuit 102 supplies the column drive data of the pixels 200 that constitute the group 151 among the pixels 200 in the first row and the signal value data of the first row to the column selection circuit 104 and the column memory 105, and repeats the same operation up to the eighth row (operation in the period 121). Next, the signal processing circuit 102 may supply the column drive data of the pixels 200 that constitute the group 152 among the pixels 200 in the first row and the signal value data of the first row to the column selection circuit 104 and the column memory 105, and repeat the same operation up to the eighth row (operation in the period 122).

[0027] In the operation shown in FIG. 4, in the period of one frame, the period 121 is a period earlier than the period 122. However, it is not limited thereto, and in the period of one frame, the period 121 may be a period later than the period 122.

[0028] By the operation shown in FIG. 4, it becomes possible to separately write signal values to the pixels 200 that constitute the group 151 with a large emission luminance whose signal value exceeds a predetermined threshold value, and the pixels 200 that constitute the group 152 with a signal value equal to or less than the predetermined threshold value. When writing a signal value exceeding the predetermined threshold value to the pixel 200, the potential of the power line common to the plurality of pixels 200 may temporarily fluctuate. Also, for example, when the signal value is rewritten, a large current flows because the pixel 200 emits light with a large luminance, and the potential of the power line may temporarily fluctuate. The temporary potential fluctuation can be larger when writing a signal value to a pixel 200 with a large emission luminance. If a signal value corresponding to the emission luminance is written while the potential of the power line is fluctuating, the signal value may fluctuate under the influence of the potential fluctuation of the power line, and uneven emission or the like may occur in the pixel row selected at the same time. The lower the emission luminance of the pixel 200, the more likely the uneven emission is to be visually recognized.

[0029] Therefore, in the present embodiment, as shown in FIG. 4, the period for writing signals is divided between the pixels 200 of the group 151 whose signal value exceeds a predetermined threshold value and the pixels 200 of the group 152 whose signal value is equal to or less than the predetermined threshold value. Thereby, it becomes possible to suppress the influence of the temporary potential fluctuation of the power line and suppress the uneven emission.

[0030] Here, the threshold value when the signal processing circuit 102 groups the pixels 200 according to the signal values may be a fixed single value. Also, for example, the threshold value when the signal processing circuit 102 groups the pixels 200 according to the signal values may be adjustable as appropriate. In that case, the threshold value may be adjusted to an appropriate value by the user, for example. Also, for example, the threshold value may change according to the level of the signal value of each of the plurality of pixels 200. For example, the signal processing circuit 102 may change the threshold value according to the average value, maximum value, minimum value, frequency distribution, etc. of the signal values of each of the plurality of pixels 200 included in the display data. A setting circuit for setting the threshold value may be provided in the light-emitting device 100. Also, for example, the threshold value may be set so that the number of pixels 200 constituting the group 151 is equal to or less than a predetermined number. For example, the threshold value may be set so that the number of pixels 200 constituting the group 151 is equal to or less than the number of pixels 200 constituting the group 152. Also, for example, the threshold value may be set so that the number of pixels 200 constituting the group 151 is equal to or less than 3 / 4, 2 / 3, or even 1 / 2 of the number of pixels 200 constituting the group 152. Thereby, it is possible to keep a temporary fluctuation in the potential of the power line within a predetermined range and suppress a deterioration in the image quality of the displayed image. The threshold value may be adjusted for each frame, or may be adjusted, for example, for each of a plurality of frames corresponding to one moving image.

[0031] FIG. 5 is a timing diagram of a modification of FIG. 4. Hereinafter, differences from the operation shown in FIG. 4 will be described. In the operation shown in FIG. 4, an example was described in which the signal values were written to the pixels 200 constituting the group 151 over all the pixel rows, and then the signal values were written to the pixels 200 constituting the group 152 over all the pixel rows. On the other hand, in the driving method shown in FIG. 5, the signal values are written to the pixels 200 constituting the group 151 and the pixels 200 constituting the group 152 for each pixel row. However, as described above, in each pixel row, the period 131 during which the signal value is written to the pixels 200 constituting the group 151 and the period 132 during which the signal value is written to the pixels 200 constituting the group 152 are different from each other.

[0032] When the signal VS(1) becomes low level at time t1, until the signal VS(1) returns to high level at time t3, the pixels 200 in the first row are each selected. During the period from time t1 to time t2, since all the signals HS(m) are at high level, the column selection transistors 202 are not turned on, and no new signal is written to the holding capacitors 203. On the other hand, during the period from time t2 to time t3, the signals HS(1) to HS(8) become low level, and the signal values are written to the holding capacitors 203 of the pixels 200 that constitute the group 152 among the pixels 200 in the first row. The same applies to the period when the pixels 200 in the second row are selected from time t3 to time t5.

[0033] Next, when the signal VS(3) becomes low level at time t5, the pixels 200 in the third row are selected until time t7. During the period 131 from time t5 to time t6, the signals HS(2), HS(3), and HS(5) become low level, and the column selection transistors 202 arranged in the 2nd, 3rd, and 5th columns transition to the on state. Thereby, the signal values are written to the pixels 200 that constitute the group 151 in the 2nd, 3rd, and 5th columns of the selected third row. Next, during the period 132 from time t6 to time t7, the signals HS(1), HS(4), HS(6), HS(7), and HS(8) become low level, and the column selection transistors 202 arranged in the 1st, 4th, 6th to 8th columns transition to the on state. Thereby, the signal values are written to the pixels 200 that constitute the group 152 in the 1st, 4th, 6th to 8th columns of the selected third row. Thereafter, in each pixel row selected using the signal VS(n), the same signal value writing is performed.

[0034] In the operation shown in FIG. 5, the driving circuit 111 sequentially selects a plurality of pixels 200 row by row. For each selected pixel row, the driving circuit 111 performs an operation in period 130 of writing a signal value to the pixels 200 arranged in the selected pixel row among the pixels 200 in group 151, and an operation in period 132 of writing a signal value to the pixels 200 arranged in the selected pixel row among the pixels 200 in group 152. For example, the signal processing circuit 102 supplies the column drive data of the pixels 200 constituting group 151 among the pixels 200 in the first row and the signal value data of the first row to the column selection circuit 104 and the column memory 105. Next, the signal processing circuit 102 supplies the column drive data of the pixels 200 constituting group 152 among the pixels 200 in the first row to the column selection circuit 104. At this time, since the signal value data of the first row has already been supplied to the column memory 105, the signal processing circuit 102 does not need to supply the signal value data of the first row to the column memory 105. That is, in the operation shown in FIG. 5, the writing of the signal value data to the column memory 105 can be performed for each row selection. By repeating this operation up to the eighth row, the operation shown in FIG. 5 can be realized.

[0035] In the operation shown in FIG. 5, after performing the operation in period 131 for each pixel row, the driving circuit 111 performs the operation in period 132. However, it is not limited thereto, and the driving circuit 111 may perform the operation in period 131 after performing the operation in period 132.

[0036] Compared with the operation shown in FIG. 4 in which the pixel rows are scanned twice in one frame period, the operation shown in FIG. 5 can shorten the switching time of the signal VS(n). Also, since the number of times of writing the signal value data to the column memory 105 is halved, it is possible to suppress the communication volume and communication time between the signal processing circuit 102 and the driving circuit 111 (column memory 105).

[0037] FIG. 6 is a modified example of the operation shown in FIG. 4, and FIG. 7 is a modified example of the operation shown in FIG. 5. In the operations shown in FIGS. 4 and 5, all the pixels 200 are selected once during one frame, and the signal values are written. However, the operation of the light-emitting device 100 is not limited thereto. As shown in FIG. 6, the drive circuit 111 may not select a pixel row in which the pixels 200 of the group 151 are not arranged during the period 121. Further, for example, the drive circuit 111 may not select a pixel row in which the pixels 200 of the group 152 are not arranged during the period 122. Similarly, as shown in FIG. 7, the drive circuit 111 may not perform the operation of the period 131 in a pixel row in which the pixels 200 of the group 151 are not arranged. Further, for example, the drive circuit 111 may not perform the operation of the period 132 in a pixel row in which the pixels 200 of the group 152 are not arranged. In the operations shown in FIGS. 6 and 7, the respective pixel rows are selected by the signal VS(n). On the other hand, when the pixel columns are not selected by the signal HS(m), the signal processing circuit 102 supplies the column drive data to the column selection circuit 104 so as to skip the time (period) for selecting the pixel columns. By this operation, it is possible to shorten the operation time of one frame.

[0038] In the configuration shown in FIG. 1, the signal processing circuit 102 has been described as being arranged inside the light-emitting device 100. However, it is not limited thereto. For example, the signal processing circuit 102 may be arranged outside the light-emitting device 100. In that case, the signal processing circuit 102 generates the above-described drive data and timing control signal based on the display data supplied from outside the signal processing circuit 102, and supplies them to the light-emitting device including the drive circuit 111 and the pixel region 110 in which a plurality of pixels 200 are arranged. Thereby, the above-described operation can be realized. In that case, the signal processing circuit 102 may also be called a signal processing device or the like. The memory 103 may be incorporated in the signal processing circuit 102, or may be arranged separately from the signal processing circuit 102.

[0039] Here, application examples of applying the light-emitting device 100 of the present embodiment to an image forming device, a display device, a photoelectric conversion device, an electronic device, a lighting device, a moving body, and a wearable device will be described with reference to FIGS. 8(a), 8(b) to FIGS. 16(a), 16(b). It is assumed that an organic light-emitting element such as an organic EL element using an organic light-emitting material is arranged in the pixel 200 of the light-emitting device 100. First, after showing the details of each configuration arranged in the pixel 200 of the above-described light-emitting device 100, application examples will be described.

[0040] An organic light-emitting element according to an embodiment of the present invention includes a first electrode, a second electrode, and an organic compound layer disposed between these electrodes. One of the first electrode and the second electrode is an anode and the other is a cathode. In the organic light-emitting element of the present embodiment, the organic compound layer may be a single layer or a laminate composed of a plurality of layers as long as it has a light-emitting layer. Here, when the organic compound layer is a laminate composed of a plurality of layers, the organic compound layer may have, in addition to the light-emitting layer, a hole injection layer, a hole transport layer, an electron blocking layer, a hole / exciton blocking layer, an electron transport layer, an electron injection layer, and the like. The light-emitting layer may be a single layer or a laminate composed of a plurality of layers. When the light-emitting layer is a plurality of layers, a charge generation layer may be provided between the light-emitting layers. The charge generation layer may be composed of a compound having a LUMO lower than that of the hole transport layer, and the LUMO of the charge generation layer may be lower than the HOMO of the hole transport layer. Here, the molecular orbital energy of the organic compound layer may be the molecular orbital energy of the organic compound having the largest weight ratio in the organic compound layer.

[0041] Here, HOMO and LUMO are described as "higher" the closer they are to the vacuum level. That the LUMO of the charge generation layer is lower than the HOMO of the hole transport layer indicates that the LUMO of the charge generation layer is closer to the vacuum level than the HOMO of the hole transport layer.

[0042] In this specification, HOMO and LUMO can be calculated using molecular orbital calculations. The molecular orbital calculation is performed by a density functional theory (DFT) or the like, the functional is B3LYP, and the basis function is 6-31G* It may be carried out using, etc. Note that the molecular orbital calculation can be carried out, for example, using Gaussian09 (Gaussian09, Revision C.01, M.J. Frisch, G.W. Trucks, H.B. Schlegel, G.E. Scuseria, M.A. Robb, J.R. Cheeseman, G. Scalmani, V. Barone, B. Mennucci, G.A. Petersson, H. Nakatsuji, M. Caricato, X. Li, H.P. Hratchian, A.F. Izmaylov, J. Bloino, G. Zheng, J.L. Sonnenberg, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H. Nakai, T. Vreven, J.A. Montgomery, Jr., J.E. Peralta, F. Ogliaro, M. Bearpark, J.J. Heyd, E. Brothers, K.N. Kudin, V.N. Staroverov, T. Keith, R. Kobayashi, J. Normand, K. Raghavachari, A. Rendell, J.C. Burant, S.S. Iyengar, J. Tomasi, M. Cossi, N. Rega, J.M. Millam, M. Klene, J.E. Knox, J.B. Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, R.E. Stratmann, O. Yazyev, A.J. Austin, R. Cammi, C. Pomelli, J.W. Ochterski, R.L. Martin, K. Morokuma, V.G. Zakrzewski, G.A. Voth, P. Salvador, J.J. Dannenberg, S. Dapprich, A.D. Daniels, O. Farkas, J.B. Foresman, J.V. Ortiz, J. Cioslowski, and D.J. Fox, Gaussian, Inc., Wallingford CT, 2010.).

[0043] In this specification, HOMO and LUMO can be calculated using ionization potential and band gap. HOMO can be estimated by measuring the ionization potential. The ionization potential can be measured with a measuring device such as AC-3 by dissolving the compound to be measured in a solvent such as toluene. The band gap can be measured by dissolving the compound to be measured in a solvent such as toluene and applying excitation light. The band gap can be measured by measuring the absorption edge of the excitation light. Alternatively, the compound to be measured can be deposited on a substrate such as glass, and the band gap can be measured by applying excitation light to the deposited film. The measurement can measure the band gap by measuring the absorption edge of the absorption spectrum absorbed by the deposited film with the excitation light.

[0044] LUMO can be calculated using the values of the band gap and ionization potential. Subtracting the value of the ionization potential from the band gap can estimate LUMO.

[0045] LUMO can also be estimated from the reduction potential. For example, the one-electron reduction potential is estimated using cyclic voltammetry (CV) measurement. The CV measurement is performed, for example, in a DMF solution of 0.1 M tetrabutylammonium perchlorate, with a reference electrode of Ag / Ag + , a counter electrode of Pt, and a working electrode of glassy carbon. LUMO can be estimated by adding the difference between the reduction potential of the obtained compound and the reduction potential of ferrocene to -4.8 eV.

[0046] In the organic light-emitting device according to an embodiment of the present invention, when the organic compound according to this embodiment is included in the light-emitting layer, the light-emitting layer may be a layer composed only of the organic compound according to this embodiment, or may be a layer composed of the organometallic complex according to this embodiment and other compounds.

[0047] Configuration of the organic light-emitting device An organic light-emitting device 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 planarization layer may be provided between the protective layer and the color filter. The planarization layer can be formed using an acrylic resin or the like. The same applies when a planarization layer is provided between the color filter and the microlens.

[0048] Substrate Examples of the substrate include quartz, glass, silicon wafers, resins, metals, etc. Further, the substrate may be provided with switching elements such as transistors and wiring patterns, and an insulating layer may be provided thereon. The insulating layer may be made of any material as long as contact holes can be formed so that wiring patterns can be formed between the first electrode and the substrate, and insulation from non-connected wiring patterns can be ensured. For example, resins such as polyimide, silicon oxide, silicon nitride, etc. may be used for the insulating layer.

[0049] Electrode As the electrodes, a pair of electrodes can be used. The pair of electrodes may be an anode and a cathode. When an electric field is applied in the light-emitting direction of the organic light-emitting device, the electrode with a higher potential is the anode, and the other is the cathode. Also, it can 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.

[0050] As the constituent material of the anode, a material with a large work function may be selected. For example, simple metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, tungsten, etc., mixtures containing these, alloys combined with these, and metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide, etc. can be used. Also, conductive polymers such as polyaniline, polypyrrole, polythiophene, etc. can be used as the constituent material of the anode.

[0051] These electrode materials may be used alone or in combination of two or more types. Also, the anode may be composed of a single layer or multiple layers.

[0052] When using the electrode as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys thereof, or those formed by laminating these can be used. With the above materials, it is also possible to function as a reflective film without having the role of an electrode. Also, when using a transparent electrode as the electrode, an oxide transparent conductive layer such as indium tin oxide (ITO) or indium zinc oxide can be used, but it is not limited thereto. For the formation of the electrode, photolithography technology can be used.

[0053] On the other hand, as the constituent material of the cathode, a material with a small work function may be selected. For example, alkali metals such as lithium, alkaline earth metals such as calcium, simple metals such as aluminum, titanium, manganese, silver, lead, chromium, and mixtures containing these can be mentioned. Alternatively, alloys combining these simple metals can also be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, zinc-silver, etc. can be used. The use of metal oxides such as indium tin oxide (ITO) is also possible. These electrode materials may be used alone or in combination of two or more types. Also, the cathode may have a single-layer structure or a multi-layer structure. As the cathode, silver may be used, and in order to reduce the aggregation of silver, a silver alloy may be used. As long as the aggregation of silver can be reduced, the ratio of the alloy does not matter. For example, silver: other metals may be 1:1, 3:1, etc.

[0054] 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 using a DC or AC sputtering method, etc., the coverage of the formed film is good, and the resistance of the cathode can be reduced.

[0055] Pixel isolation layer The pixel isolation layer may be formed of a so-called silicon oxide such as silicon nitride (SiN), silicon oxynitride (SiON), or silicon oxide (SiO) formed using a chemical vapor deposition (CVD) method. In order to increase the in-plane resistance of the organic compound layer, the film thickness of the organic compound layer, particularly the hole transport layer, may be formed thinner on the sidewalls of the pixel isolation layer. Specifically, by increasing the taper angle of the sidewalls of the pixel isolation layer and the film thickness of the pixel isolation layer, and increasing the peeling during vapor deposition, the film thickness of the organic processed material layer on the sidewalls can be formed thinner.

[0056] On the other hand, the sidewall taper angle and the film thickness of the pixel isolation layer can be adjusted so that voids are not 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, a decrease in reliability such as the occurrence of dark spots and poor conduction of the second electrode can be reduced.

[0057] According to this embodiment, even if the taper angle of the sidewalls of the pixel isolation 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 sufficient reduction can be achieved if the taper angle is in the range of 60 degrees or more and 90 degrees or less. The film thickness of the pixel isolation layer may be from 10 nm to 150 nm. The same effect can also be obtained even when only pixel electrodes without a pixel isolation layer are used. However, in this case, the film thickness of the pixel electrode should be less than half of the organic layer, or the end of the pixel electrode should be a forward taper of less than 60° to reduce the short circuit of the organic light-emitting element.

[0058] Also, when the first electrode is a cathode and the second electrode is an anode, a high color gamut and low voltage driving can be achieved by forming an electron transport material and a charge transport layer, and a light-emitting layer on the charge transport layer.

[0059] Organic compound layer The organic compound layer may be formed as a single layer or as multiple layers. When there are multiple layers, depending on their functions, they may be referred to as 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, etc. The organic compound layer is mainly composed of organic compounds, but may also contain inorganic atoms or inorganic compounds. The organic compound layer may have, for example, copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, zinc, etc. 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. When there are multiple light-emitting layers, a charge generation section may be provided between the first light-emitting layer and the second light-emitting layer. The charge generation section may have an organic compound with a lowest unoccupied molecular orbital energy (LUMO) of -5.0 eV or less. The same applies when there is a charge generation section between the second light-emitting layer and the third light-emitting layer.

[0060] Protective layer A protective layer may be provided on the cathode. For example, by adhering glass provided with a moisture absorbent on the cathode, the intrusion of moisture, etc. into the organic compound layer can be reduced, and the occurrence of display defects can be reduced. Also, as another embodiment, a passivation layer such as silicon nitride may be provided on the cathode to reduce the intrusion of moisture, etc. into the organic compound layer. For example, after forming the cathode, it may be transported to another chamber without breaking the vacuum, and silicon nitride with a thickness of 2 μm may be formed by CVD method to be used as a protective layer. After forming the protective layer by CVD method, a protective layer using atomic layer deposition (ALD) method may be provided. The material of the protective layer by ALD method is not limited, but may be silicon nitride, silicon oxide, aluminum oxide, etc. Silicon nitride may be further formed by CVD method on the protective layer formed by ALD method. The protective layer formed by ALD method may have a smaller film thickness than the protective layer formed by CVD method. Specifically, the film thickness of the protective layer formed by ALD method may be 50% or less, and further 10% or less of the film thickness of the protective layer formed by CVD method.

[0061] Color filter A color filter may be provided on the protective layer. For example, a color filter considering 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. Also, for example, a color filter may be patterned on the above-described protective layer using photolithography technology. The color filter may be composed of a polymer.

[0062] 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 the unevenness of the layer below the planarization layer. Without limiting the purpose, it may be called a material resin layer in some cases. The planarization layer may be composed of an organic compound, and may be a low molecule or a high molecule. Considering the reduction of unevenness, a high molecular organic compound may be used for the planarization layer.

[0063] The planarization layer may be provided above and below the color filter. In that case, the constituent materials of the respective planarization layers may be the same or different. Specifically, polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicon resin, urea resin, etc. may be mentioned as materials for the planarization layer.

[0064] Micro lens The organic light-emitting device may have an optical member such as a micro lens on its light-emitting side. The micro lens can be composed of an acrylic resin, an epoxy resin, etc. The micro lens may be for the purpose of increasing the amount of light extracted from the organic light-emitting device and controlling the direction of the extracted light. The micro lens may have a hemispherical shape. When having a hemispherical shape, among the tangents in contact with the hemisphere, there is a tangent parallel to the insulating layer, and the contact point between the tangent and the hemisphere is the apex of the micro lens. The apex of the micro lens can be determined in the same way in any cross-sectional view. That is, among the tangents in contact with the semi-circle of the micro lens in the cross-sectional view, there is a tangent parallel to the insulating layer, and the contact point between the tangent and the semi-circle is the apex of the micro lens.

[0065] Also, the midpoint of the microlens can be defined. In the cross-section of the microlens, a line segment from the point where the arc shape ends to the point where another arc shape ends can be imagined, and the midpoint of this line segment can be called the midpoint of the microlens. The cross-section for discriminating the vertex and the midpoint may be a cross-section perpendicular to the insulating layer.

[0066] The microlens has a first surface having a convex portion and a second surface opposite to the first surface. The second surface can be arranged closer to the functional layer (light-emitting layer) side than the first surface. To adopt such a configuration, it is necessary to form a microlens on the light-emitting device. When the functional layer is an organic layer, processes that become high temperature in the manufacturing process of the microlens may be avoided. Further, when the second surface is arranged closer to the functional layer side than the first surface, the glass transition temperatures of all the organic compounds constituting the organic layer may be 100°C or higher, and for example, it is suitable that they are 130°C or higher.

[0067] Counter substrate The counter substrate may be arranged on the planarization layer. Since the counter substrate is provided at a position corresponding to the aforementioned substrate, it is called the counter substrate. The constituent material of the counter substrate may be the same as that of the aforementioned substrate. The counter substrate may be the second substrate when the aforementioned substrate is the first substrate.

[0068] 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 the embodiment of the present disclosure may be formed by the following method.

[0069] For the organic compound layers constituting the organic light-emitting element according to the embodiment of the present disclosure, dry processes such as vacuum evaporation, ionization evaporation, sputtering, and plasma can be used. Also, instead of the dry process, a wet process of dissolving in an appropriate solvent and forming a layer by a known coating method (for example, spin coating, dipping, casting method, LB method, inkjet method, etc.) can also be used.

[0070] When a layer is formed by a vacuum evaporation method, a solution coating method, or the like, crystallization and the like hardly occur, and the stability over time is excellent. Further, when forming a film by a coating method, a film can also be formed in combination with an appropriate binder resin.

[0071] Examples of the binder resin include, but are not limited to, polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, urea resin, and the like.

[0072] Further, these binder resins may be used alone as a homopolymer or a copolymer, or two or more of them may be mixed and used. Furthermore, additives such as known plasticizers, antioxidants, and ultraviolet absorbers may be used in combination as necessary.

[0073] 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 independently controls the light emission of the first light-emitting element and the second light-emitting element. The active matrix type circuit may be voltage programming or current programming. The drive circuit has a pixel circuit for each pixel. The pixel circuit may have a light-emitting element, a transistor for controlling the light emission luminance of the light-emitting element, a transistor for controlling the light emission timing, a capacitor for holding the gate voltage of the transistor for controlling the light emission luminance, and a transistor for connecting to GND without passing through the light-emitting element.

[0074] The light-emitting device has a display area and a peripheral area arranged around the display area. The display area has a pixel circuit, and the peripheral area has a display control circuit. The mobility of the transistor constituting the pixel circuit may be smaller than the mobility of the transistor constituting the display control circuit.

[0075] The slope of the current-voltage characteristics of the transistor constituting the pixel circuit may be smaller than the slope of the current-voltage characteristics of the transistor constituting the display control circuit. The slope of the current-voltage characteristics can be measured by so-called Vg-Ig characteristics.

[0076] The transistor constituting the pixel circuit is a transistor connected to a light-emitting element such as a first light-emitting element.

[0077] Pixel The organic light-emitting device has a plurality of pixels. The pixels have sub-pixels that emit different colors from each other. The sub-pixels may each have, for example, emission colors of RGB.

[0078] The pixel emits light from a region also called a pixel aperture. The pixel aperture may be 15 μm or less and may be 5 μm or more. More specifically, it may be 11 μm, 9.5 μm, 7.4 μm, 6.4 μm, etc.

[0079] The interval between sub-pixels may be 10 μm or less, and specifically may be 8 μm, 7.4 μm, 6.4 μm.

[0080] The pixel can take a known arrangement form in a plan view. For example, it may be a stripe arrangement, a delta arrangement, a pentile arrangement, or a Bayer arrangement. The shape of the sub-pixel in the plan view may take any known shape. For example, it may be a rectangle, a quadrilateral such as a rhombus, a hexagon, etc. Of course, even if it is not an exact figure but has a shape close to a rectangle, it is included in the rectangle. The shape of the sub-pixel and the pixel arrangement can be used in combination.

[0081] Use of the organic light-emitting element according to the embodiment of the present disclosure The organic light-emitting element according to the embodiment of the present disclosure can be used as a constituent member of a display device or a lighting device. In addition, there are applications such as an exposure light source of an electrophotographic image forming device, a backlight of a liquid crystal display device, and a light-emitting device having a color filter for a white light source.

[0082] 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 a display unit that displays the input image.

[0083] In addition, the display unit included in the imaging device or the inkjet printer may have a touch panel function. The driving method of this touch panel function may be an infrared method, a capacitance method, a resistive film method, or an electromagnetic induction method, and is not particularly limited. Also, the display device may be used for the display unit of a multifunction printer.

[0084] Next, further explanation will be given with reference to the drawings. FIG. 8(a) is an example of a pixel 200 arranged in the light-emitting device 100. The pixel has a sub-pixel 810 (pixel 200). The sub-pixel is divided into 810R, 810G, and 810B according to its light emission. The emission 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 which is a first electrode on the 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 which is a second electrode, a protective layer 806, and a color filter 807.

[0085] A transistor or a capacitor element may be arranged in the lower layer or inside the interlayer insulating layer 801. The transistor and the first electrode may be electrically connected via a contact hole (not shown).

[0086] The insulating layer 803 may also be called a bank or a pixel isolation film. The insulating layer 803 covers the edge of the first electrode and is arranged surrounding the first electrode. The portion of the first electrode where the insulating layer 803 is not arranged is in contact with the organic compound layer 804 and becomes the light-emitting region.

[0087] 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.

[0088] The second electrode may be a transparent electrode, a reflective electrode, or a transflective electrode.

[0089] The protective layer 806 reduces the penetration of moisture into the organic compound layer. Although the protective layer is shown as a single layer, it may be a plurality of layers. Each layer may be an inorganic compound layer or an organic compound layer.

[0090] The color filter 807 is divided into 807R, 807G, and 807B according to its color. The color filter may be formed on a planarization film (not shown). Also, a resin protective layer (not shown) may be disposed on the color filter. Further, the color filter may be formed on the protective layer 806. Also, the color filter may be bonded after being provided on a counter substrate such as a glass substrate.

[0091] The display device 800 (corresponding to the above-described light-emitting device 100) in FIG. 8(b) describes an organic light-emitting element 826 and a TFT 818 as an example of a transistor. A substrate 811 such as glass or silicon and an insulating layer 812 are provided on the upper part thereof. Active elements such as the TFT 818 are arranged on the insulating layer, and a gate electrode 813, a gate insulating film 814, and a semiconductor layer 815 of the active element are arranged. 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. The anode 821 constituting the organic light-emitting element 826 and the source electrode 817 are connected through a contact hole 820 provided in the insulating film.

[0092] 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 mode shown in FIG. 8(b). That is, it is sufficient that either one of the anode or the cathode is electrically connected to either one of the TFT source electrode or the drain electrode. The TFT refers to a thin-film transistor.

[0093] In the display device 800 of FIG. 8(b), the organic compound layer is illustrated as if it were a single layer, but the organic compound layer 822 may be a plurality of layers. On the cathode 823, a first protective layer 824 and a second protective layer 825 for reducing the deterioration of the organic light-emitting element are provided.

[0094] In the display device 800 of FIG. 8(b), a transistor is used as the switching element, but another switching element may be used instead.

[0095] Further, the transistor used in the display device 800 of FIG. 8(b) is not limited to a transistor using a single-crystalline silicon wafer, and may be a thin-film transistor having an active layer on an insulating surface of a substrate. Examples of the active layer include non-single-crystalline silicon such as single-crystalline silicon, amorphous silicon, and microcrystalline silicon, and non-single-crystalline oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Note that the thin-film transistor is also called a TFT element.

[0096] The transistor included in the display device 800 of FIG. 8(b) may be formed in a substrate such as a silicon substrate. Here, forming in the substrate means manufacturing a transistor by processing the substrate itself such as a silicon substrate. That is, having a transistor in the substrate can also be regarded as the substrate and the transistor being integrally formed.

[0097] The organic light-emitting element according to this embodiment has its emission luminance controlled by a TFT which is an example of a switching element, and an image can be displayed by the emission luminance of each organic light-emitting element provided in a plurality of planes. 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 the substrate" can also mean "in the substrate". Whether to provide a transistor in the substrate or use a TFT is selected according to the size of the display portion. For example, if the size is about 0.5 inches, an organic light-emitting element may be provided on a silicon substrate.

[0098] Figs. 9(a) to 9(c) are schematic views showing an example of an image forming apparatus using the light emitting device 100 of the present embodiment. The image forming apparatus 926 shown in Fig. 9(a) includes a photoreceptor 927, an exposure light source 928, a developing unit 931, a charging unit 930, a transferrer 932, a conveying unit 933 (a conveying roller in the configuration of Fig. 9(a)), and a fixing unit 935.

[0099] Light 929 is irradiated from the exposure light source 928, and an electrostatic latent image is formed on the surface of the photoreceptor 927. The light emitting device 100 can be applied to this exposure light source 928. The developing unit 931 can function as a developer that contains toner or the like as a developer and applies the developer to the exposed photoreceptor 927. The charging unit 930 charges the photoreceptor 927. The transferrer 932 transfers the developed image onto a recording medium 934. The conveying unit 933 conveys the recording medium 934. The recording medium 934 can be, for example, paper, film, or the like. The fixing unit 935 fixes the image formed on the recording medium.

[0100] Figs. 9(b) and 9(c) are schematic views showing a state in which a plurality of light emitting portions 936 are arranged along the longitudinal direction on a long substrate for the exposure light source 928. The light emitting device 100 can be applied to this light emitting portion 936. That is, a plurality of pixels 200 are arranged along the longitudinal direction of the substrate. The direction 937 is a direction parallel to the axis of the photoreceptor 927. This column direction is the same as the direction of the axis when the photoreceptor 927 rotates. This direction 937 can also be referred to as the major axis direction of the photoreceptor 927.

[0101] FIG. 9(b) shows a configuration in which the light-emitting unit 936 is arranged along the major axis direction of the photoreceptor 927. FIG. 9(c) is a modification of the arrangement of the light-emitting unit 936 shown in FIG. 9(b), in which the light-emitting units 936 are alternately arranged in the column direction in each of the first column and the second column. In the first column and the second column, the light-emitting units 936 are arranged at different positions in the row direction. 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. Also, in the row direction, a plurality of light-emitting units 936 are arranged at intervals. The arrangement of the light-emitting units 936 shown in FIG. 9(c) can be described as, for example, a state of being arranged in a grid pattern, a state of being arranged in a staggered grid, or a checkerboard pattern.

[0102] FIG. 10 is a schematic diagram showing an example of a display device using the light-emitting device 100 of the present embodiment. The display device 1000 may include a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. The touch panel 1003 and the display panel 1005 are connected to flexible printed circuits FPC 1002 and 1004. Active elements such as transistors are arranged on the circuit board 1007. The battery 1008 may not be provided if the display device 1000 is not a portable device, or even if it is a portable device, it is not necessary to be provided at this position. The light-emitting device 100 can be applied to the display panel 1005. The pixel 200 arranged in the light-emitting device 100 functioning as the display panel 1005 is connected to and operates with active elements such as transistors arranged on the circuit board 1007.

[0103] The display device 1000 shown in FIG. 10 may be used in the 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 the light passing through the optical unit and performs photoelectric conversion into an electrical signal. The photoelectric conversion device may have a display unit that displays the information acquired by the imaging element. Further, the display unit may be a display unit exposed to the outside of the photoelectric conversion device or a display unit disposed within the viewfinder. The photoelectric conversion device may be a digital camera or a digital video camera.

[0104] FIG. 11 is a schematic diagram showing an example of a photoelectric conversion device using the light-emitting device 100 of the present 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 the present embodiment can be applied to the viewfinder 1101 and the rear display 1102 which are display units. In this case, the light-emitting device 100 may display not only the image to be captured but also environmental information, imaging instructions, etc. The environmental information may include the intensity of external light, the direction of external light, the speed at which the subject moves, the possibility that the subject is shielded by an obstacle, etc.

[0105] Since the timing suitable for imaging is often a very short time, it is better to display the information as soon as possible. Therefore, the light-emitting device 100 in which pixels 200 including a light-emitting element using an organic light-emitting material such as an organic EL element are arranged may be used for the viewfinder 1101 and the rear display 1102. This is because the organic light-emitting material has a fast response speed. The light-emitting device 100 using an organic light-emitting material is more suitable for these devices where a display speed is required than a liquid crystal display device.

[0106] The photoelectric conversion device 1100 has an optical unit (not shown). The optical unit has a plurality of lenses and forms an image on a photoelectric conversion element (not shown) housed within the housing 1104 that receives the light passing through the optical unit. The plurality of lenses can adjust the focus by adjusting their relative positions. This operation can also be performed automatically.

[0107] The light-emitting device 100 may be applied to the display unit of an electronic device. In that case, it may have both a display function and an operation function. Examples of the portable terminal include mobile phones such as smartphones, tablets, head-mounted displays, and the like.

[0108] FIG. 12 is a schematic diagram showing an example of an electronic device using the light-emitting device 100 of the present embodiment. The electronic device 1200 includes a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may include 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 reaction unit of a touch panel method. 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 may also be referred to as a communication device. The light-emitting device 100 of the present embodiment can be applied to the display unit 1201.

[0109] FIGS. 13(a) and 13(b) are schematic diagrams showing an example of a display device using the light-emitting device 100 of the present embodiment. FIG. 13(a) is a display device such as a TV monitor or a PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The light-emitting device 100 of the present embodiment can be applied to the display unit 1302. The display device 1300 may have a base 1303 that supports the frame 1301 and the display unit 1302. The base 1303 is not limited to the form of FIG. 13(a). For example, the lower side of the frame 1301 may also serve as the base 1303. Further, 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.

[0110] FIG. 13(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 in FIG. 13(b) is configured to be foldable and is a so-called foldable display device. The display device 1310 includes 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 a single seamless display device. 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 may display one image together with the first display unit and the second display unit.

[0111] FIG. 14 is a schematic diagram showing an example of a lighting device using the light-emitting device 100 of the present embodiment. The lighting device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404, and a light diffusion unit 1405. The light-emitting device 100 of the present embodiment can be applied to the light source 1402. The optical film 1404 may be a filter for improving the color rendering property of the light source. The light diffusion unit 1405 can effectively diffuse the light of the light source, such as lighting up, and deliver the light to a wide range. If necessary, a cover may be provided on the outermost side. The lighting device 1400 may have both the optical film 1404 and the light diffusion unit 1405, or may have only one of them.

[0112] The lighting device 1400 is, for example, a device for lighting an interior. The lighting device 1400 may emit any color from white, warm white, to other colors from blue to red. It may have a dimming circuit for dimming them. The lighting device 1400 may have a power supply circuit connected to the light-emitting device 100 that functions as a light source 1402. The power supply circuit is a circuit that converts an AC voltage into a DC voltage. Also, white has a color temperature of 4200K and warm white has a color temperature of 5000K. Further, the lighting device 1400 may have a color filter. Also, the lighting device 1400 may have a heat dissipation part. The heat dissipation part releases the heat inside the device to the outside of the device, and examples include metals with high specific heat and liquid silicon.

[0113] FIG. 15 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 the present embodiment. The automobile 1500 has a tail lamp 1501, and when a braking operation or the like is performed, the tail lamp 1501 may be lit. The light-emitting device 100 of the present 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 railway vehicle, an industrial robot, or the like. The moving body may have a body and a lamp provided thereon. The lamp may be for notifying the current position of the body.

[0114] The light-emitting device 100 of the present embodiment can be applied to the tail lamp 1501. The tail lamp 1501 may have a protective member for protecting the light-emitting device 100 that functions as the tail lamp 1501. The protective member has a certain degree of strength and may be made of any material as long as it is transparent, and may be made of polycarbonate or the like. Also, the protective member may be mixed with a phthalic acid derivative, an acrylonitrile derivative, or the like in the polycarbonate.

[0115] Automobile 1500 may have a vehicle 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 for the transparent display. In this case, constituent materials such as electrodes included in the light-emitting device 100 are formed of transparent members.

[0116] With reference to FIGS. 16(a) and 16(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 wearable as a wearable device such as smart glasses, a head-mounted display (HMD), or smart contact, for example. An imaging display device used in such an application example includes an imaging device capable of photoelectrically converting visible light and a light-emitting device capable of emitting visible light.

[0117] FIG. 16(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 surface side of the lens 1601 of the glasses 1600. Further, the light-emitting device 100 of the present embodiment is provided on the back surface side of the lens 1601.

[0118] The glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the imaging device 1602 and the light-emitting device 100 according to each embodiment. Further, the control device 1603 controls the operations of the imaging device 1602 and the light-emitting device 100. An optical system for condensing light onto the imaging device 1602 is formed on the lens 1601.

[0119] FIG. 16(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 the light emitting device 100 are mounted on the control device 1612. An optical system for projecting light emitted from the imaging device 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 operations of the imaging device and the light emitting device 100. The control device 1612 may have a gaze detection unit that detects the wearer's gaze. Infrared rays may be used for gaze detection. The infrared light emitting unit emits infrared light to the eyeball of the user who is gazing at the display image. An imaging image of the eyeball can be obtained by detecting the reflected light of the emitted infrared light from the eyeball with an imaging unit having a light receiving element. By having a reducing means for reducing the light from the infrared light emitting unit to the display unit in a plan view, a decrease in image quality is reduced.

[0120] The user's gaze with respect to the display image is detected from the imaging image of the eyeball obtained by imaging infrared light. Any known method can be applied to gaze detection using the imaging image of the eyeball. As an example, a gaze detection method based on the Purkinje image by reflection of irradiation light on the cornea can be used.

[0121] More specifically, a gaze detection process based on the pupillary corneal reflex method is performed. Using the pupillary corneal reflex method, a gaze vector representing the orientation (rotation angle) of the eyeball is calculated based on the image of the pupil and the Purkinje image included in the imaging image of the eyeball, thereby detecting the user's gaze.

[0122] The light emitting device 100 according to the embodiment of the present disclosure may have an imaging device having a light receiving element, and may control a display image based on the user's gaze information from the imaging device.

[0123] Specifically, the light-emitting device 100 determines a first viewing area that the user gazes at and a second viewing area other than the first viewing area based on the line-of-sight information. The first viewing area and the second viewing area may be determined by the 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 viewing area may be controlled to be higher than that of the second viewing area. That is, the resolution of the second viewing area may be made lower than that of the first viewing area.

[0124] Further, the display area has a first display area and a second display area different from the first display area, and an area with a higher priority is determined from the first display area and the second display area based on the line-of-sight information. The first display area and the second display area may be determined by the control device of the light-emitting device 100, or may be received from an external control device. The resolution of the area with a higher priority may be controlled to be higher than that of the area other than the area with a higher priority. That is, the resolution of the area with a relatively lower priority may be made lower.

[0125] Note that AI may be used to determine the first viewing area or the area with a higher priority. AI may be a model configured to estimate the angle of the line of sight and the distance to the target at the tip of the line of sight from an image of the eyeball using the image of the eyeball and the direction in which the eyeball in the image is actually looking as teacher data. The AI program may be possessed by the light-emitting device 100, the imaging device, or an external device. When it is possessed by an external device, it is transmitted to the light-emitting device 100 via communication.

[0126] When performing display control based on visual recognition detection, it can be applied to smart glasses further having an imaging device for imaging the outside. The smart glasses can display the imaged external information in real time.

[0127] The disclosure of this specification includes the following light-emitting devices, display devices, photoelectric conversion devices, electronic devices, lighting devices, and moving bodies.

[0128] (Item 1) A plurality of pixels each including a light-emitting element and arranged to form rows and columns, A driving circuit for writing a signal value corresponding to the emission luminance to each of the plurality of pixels, and a signal processing circuit, and is a light-emitting device including: the signal processing circuit selects a first group of pixels formed by pixels among the plurality of pixels whose signal values exceed a predetermined threshold value, and a second group of pixels formed by pixels among the plurality of pixels whose signal values are equal to or less than the predetermined threshold value, the driving circuit writes a signal value to the pixels included in the first group in a first period, and writes a signal to the pixels included in the second group in a second period different from the first period. A light-emitting device characterized by that.

[0129] (Item 2) The driving circuit is in the first period, selects the plurality of pixels for each pixel row, and writes a signal value to the pixels arranged in the selected pixel row among the pixels in the first group, in the second period, selects the plurality of pixels for each pixel row, and writes a signal value to the pixels arranged in the selected pixel row among the pixels in the second group. The light-emitting device according to Item 1, characterized by that.

[0130] (Item 3) The light-emitting device according to Item 2, characterized in that the first period is a period before the second period.

[0131] (Item 4) The light-emitting device according to Item 2, characterized in that the first period is a period after the second period.

[0132] (Item 5) The driving circuit does not select a pixel row in which the pixels in the first group are not arranged in the first period. The light-emitting device according to any one of Items 2 to 4.

[0133] (Item 6) The driving circuit is selects the plurality of pixels for each pixel row, For each selected pixel row, perform a first operation in the first period of writing a signal value to the pixels arranged in the selected pixel row among the pixels in the first group, and a second operation in the second period of writing a signal value to the pixels arranged in the selected pixel row among the pixels in the second group, the light-emitting device according to claim 1, characterized in that.

[0134] (Item 7) The driving circuit performs the second operation after performing the first operation for each pixel row, the light-emitting device according to claim 6, characterized in that.

[0135] (Item 8) The driving circuit performs the first operation after performing the second operation for each pixel row, the light-emitting device according to claim 6, characterized in that.

[0136] (Item 9) The driving circuit does not perform the first operation in the pixel rows where the pixels of the first group are not arranged, the light-emitting device according to any one of claims 6 to 8, characterized in that.

[0137] (Item 10) The light-emitting device according to any one of claims 1 to 9, further comprising a memory for holding the signal values of each of the plurality of pixels, characterized in that.

[0138] (Item 11) The signal processing circuit performs discrimination between the pixels in the first group and the pixels in the second group based on the signal values held in the memory, the light-emitting device according to claim 10, characterized in that.

[0139] (Item 12) The predetermined threshold value changes according to the level of the signal value of each of the plurality of pixels, the light-emitting device according to any one of claims 1 to 11, characterized in that.

[0140] (Item 13) A display device, comprising the light-emitting device according to any one of claims 1 to 12 and an active element connected to the light-emitting device, characterized in that.

[0141] (Item 14) 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. The display unit displays an image captured by the image sensor and has a light-emitting device according to any one of Items 1 to 12. A photoelectric conversion device characterized by this.

[0142] (Item 15) A housing provided with a display unit, and a communication unit provided in the housing for communicating with the outside. The display unit has a light-emitting device according to any one of Items 1 to 12. An electronic device characterized by this.

[0143] (Item 16) An illumination device having a light source and at least one of a light diffusion unit and an optical film. The light source has a light-emitting device according to any one of Items 1 to 12. An illumination device characterized by this.

[0144] (Item 17) A moving body having a body and a lighting fixture provided on the body. The lighting fixture has a light-emitting device according to any one of Items 1 to 12. A moving body characterized by this.

[0145] The invention is not limited to the above embodiments, and various changes and modifications are possible without departing from the spirit and scope of the invention. Therefore, claims are attached to disclose the scope of the invention.

Explanation of Signs

[0146] 100: Light-emitting device, 102: Signal processing circuit, 111: Drive circuit, 121, 122, 131, 132: Periods, 151, 152: Groups, 200: Pixel, 205: Light-emitting element

Claims

1. A plurality of pixels each having a light-emitting element, arranged to form rows and columns, a driving circuit that writes a signal value corresponding to the light-emitting luminance to each of the plurality of pixels, and a signal processing circuit, and a light-emitting device including the same, wherein the signal processing circuit selects a first group of pixels formed by pixels among the plurality of pixels whose signal values exceed a predetermined threshold value and a second group of pixels formed by pixels among the plurality of pixels whose signal values are equal to or less than the predetermined threshold value, and the driving circuit writes a signal value to the pixels included in the first group in a first period, and writes a signal to the pixels included in the second group in a second period different from the first period. The light-emitting device is characterized by this.

2. The driving circuit is in the first period, selects the plurality of pixels row by row, and writes a signal value to the pixels arranged in the selected pixel rows among the pixels in the first group, and in the second period, selects the plurality of pixels row by row, and writes a signal value to the pixels arranged in the selected pixel rows among the pixels in the second group. The light-emitting device according to claim 1 is characterized by this.

3. The light-emitting device according to claim 2, wherein the first period is a period before the second period.

4. The light-emitting device according to claim 2, wherein the first period is a period after the second period.

5. The driving circuit does not select pixel rows in which the pixels in the first group are not arranged in the first period. The light-emitting device according to claim 2 is characterized by this.

6. The driving circuit is selects the plurality of pixels row by row, and for each selected pixel row, performs a first operation in the first period of writing a signal value to the pixels arranged in the selected pixel rows among the pixels in the first group and a second operation in the second period of writing a signal value to the pixels arranged in the selected pixel rows among the pixels in the second group. The light-emitting device according to claim 1 is characterized by this.

7. The driving circuit according to claim 6, wherein for each pixel row, the second operation is performed after the first operation.

8. The driving circuit according to claim 6, wherein for each pixel row, the first operation is performed after the second operation.

9. The light-emitting device according to claim 6, wherein the drive circuit does not perform the first operation in a pixel row where the pixels of the first group are not arranged.

10. The light-emitting device according to claim 1, further comprising a memory for holding the signal value of each of the plurality of pixels.

11. The light-emitting device according to claim 10, wherein the signal processing circuit selects the pixels of the first group and the pixels of the second group based on the signal values held in the memory.

12. The light-emitting device according to claim 1, wherein the predetermined threshold value changes according to the level of the signal value of each of the plurality of pixels.

13. A display device comprising the light-emitting device according to any one of claims 1 to 12 and an active element connected to the light-emitting device.

14. An optoelectronic conversion device comprising an optical unit having a plurality of lenses, an imaging element that receives light that has passed through the optical unit, and a display unit that displays an image, wherein the display unit displays an image captured by the imaging element and includes the light-emitting device according to any one of claims 1 to 12.

15. An electronic device comprising a housing provided with a display unit and a communication unit provided in the housing for communicating with the outside, wherein the display unit includes the light-emitting device according to any one of claims 1 to 12.

16. An illumination device comprising a light source and at least one of a light diffusing unit and an optical film, wherein the light source includes the light-emitting device according to any one of claims 1 to 12.

17. A moving body comprising a body and a lighting fixture provided on the body, wherein the lighting fixture includes the light-emitting device according to any one of claims 1 to 12.

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