Image Correction System

Abstract

To provide a novel image correction system.SOLUTION: An image correction system includes an imaging device, a first arithmetic device, a display portion including a plurality of pixels, and a second arithmetic device. The imaging device obtains imaging data by capturing a first-gray-level image displayed on the display portion. The first arithmetic device calculates luminous intensity of each of the pixels and a correction standard by using the imaging data. The first arithmetic device calculates correction data for each of the pixels by using the luminous intensity and the correction standard. The second arithmetic device corrects a video signal by using the correction data. The display portion displays an image using the corrected video signal. The first arithmetic device calculates correction data for pixels that emit red light, pixels that emit green light, and pixels that emit blue light and modifies the correction data by using color temperature data.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] One aspect of the present invention relates to an image correction method and an image correction system.

[0002] Note that one aspect of the present invention is not limited to the above technical field. Examples of the technical field of one aspect of the present invention disclosed in this specification and the like include semiconductor devices, display devices, light-emitting devices, power storage devices, storage devices, electronic devices, lighting devices, input devices, input / output devices, driving methods thereof, or manufacturing methods thereof.

Background Art

[0003] An active matrix type display device having a transistor for driving a display element for each pixel of a display device is known. For example, an active matrix type liquid crystal display device using a liquid crystal element as a display element, an active matrix type light-emitting display device using a light-emitting element such as an organic EL element as a display element, and the like are known.

[0004] In order to improve the display quality of a display device, various correction methods for image data have been proposed. For example, Patent Document 1 discloses a configuration in which an image displayed on a display unit is imaged by an imaging device to create correction data, and the unevenness of the display image is made less noticeable using this correction data.

[0005] In recent years, an increase in the resolution (number of pixels) of display devices has been demanded for display devices for televisions or monitors, display devices for smartphones or tablet terminals, and the like. In particular, in display devices for virtual reality (VR) or augmented reality (AR), display devices with high resolution are demanded.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] Generally, the pixels of a full-color display device consist of sub-pixels that emit red light, sub-pixels that emit green light, and sub-pixels that emit blue light. The display elements and the pixel circuits that drive them have complex manufacturing processes, making them prone to variation in characteristics. To improve the display quality of display devices, it is necessary to correct for the variation in characteristics of each sub-pixel.

[0008] Furthermore, as the resolution of a display device increases, it becomes more susceptible to variations in the characteristics of the transistors that make up the pixels, as well as variations in the characteristics of the display elements, which can make a decrease in display quality, such as display unevenness, more easily noticeable.

[0009] One aspect of the present invention aims to provide an image correction system that improves the display quality of a display device. Alternatively, one aspect of the present invention aims to provide an image correction method that improves the display quality of a display device. Alternatively, one aspect of the present invention aims to provide a novel image correction system. Alternatively, one aspect of the present invention aims to provide a novel image correction method.

[0010] Furthermore, the description of these problems does not preclude the existence of other problems. Moreover, one aspect of the present invention does not need to solve all of these problems. Other problems can be identified from the description in the specification, drawings, claims, etc. [Means for solving the problem]

[0011] One aspect of the present invention is an image correction method for a display device having a plurality of pixels arranged in a matrix, comprising: a first step of acquiring the luminance distribution of an image displayed in a first grayscale; a second step of determining the position and area of ​​each of the plurality of pixels using the luminance distribution; a third step of calculating the luminance of each of the plurality of pixels using the luminance distribution; a fourth step of determining a correction standard using the luminance of each of the plurality of pixels; a fifth step of generating correction data using the correction standard and the luminance of each of the plurality of pixels; a sixth step of storing the correction data in a storage device; and a seventh step of correcting the video signal supplied to each of the plurality of pixels using the correction data stored in the storage device.

[0012] Another aspect of the present invention is an image correction system having an imaging device, a first processing unit, a display unit having a plurality of pixels, and a second processing unit, wherein the imaging device has a function to capture a first grayscale image displayed on the display unit and acquire a brightness distribution, the first processing unit has a function to calculate the luminance of each of the plurality of pixels using the brightness distribution, a function to calculate a correction criterion, and a function to calculate correction data for each of the plurality of pixels using the luminance of each of the plurality of pixels and the correction criterion, and the second processing unit has a function to correct a video signal for displaying an image on the display unit using the correction data.

[0013] The correction criterion may be, for example, the maximum, average, or median luminosity of each of the multiple pixels. Alternatively, any luminosity may be set as the correction criterion.

[0014] Furthermore, an image correction system according to one aspect of the present invention may have a first storage device and a second storage device. For example, the first storage device may have a function for storing imaging data, and the second storage device may have a function for storing correction data.

[0015] Another aspect of the present invention is an image correction system having an imaging device, a first processing unit, a display unit, and a second processing unit, wherein the display unit has a plurality of first pixels emitting a first light, a plurality of second pixels emitting a second light, and a plurality of third pixels emitting a third light; the imaging device has a function to capture a first grayscale image displayed on the display unit and acquire a luminance distribution; and the first processing unit has a function to calculate the luminance of each of the plurality of first pixels using the luminance distribution, a function to calculate a first correction criterion, a function to calculate the luminance of each of the plurality of second pixels, a function to calculate a second correction criterion, a function to calculate the luminance of each of the plurality of third pixels, and a third correction criterion The first computing unit has a function to calculate a positive reference, and the second computing unit has a function to calculate first correction data for each of a plurality of first pixels using the luminosity and first correction reference of each of a plurality of first pixels, a function to calculate second correction data for each of a plurality of second pixels using the luminosity and second correction reference of each of a plurality of second pixels, and a function to calculate third correction data for each of a plurality of third pixels using the luminosity and third correction reference of each of a plurality of third pixels, and the second computing unit has a function to correct the video signal for displaying an image on the display unit using the first correction data, second correction data, and third correction data.

[0016] The first correction criterion may be, for example, the maximum, average, or median luminosity of each of the multiple first pixels. The second correction criterion may be, for example, the maximum, average, or median luminosity of each of the multiple second pixels. The third correction criterion may be, for example, the maximum, average, or median luminosity of each of the multiple third pixels. Any luminosity may be set for each of the first to third correction criteria.

[0017] Furthermore, an image correction system according to one aspect of the present invention may have a first storage device and a second storage device. For example, the first storage device may have a function for storing imaging data, and the second storage device may have a function for storing first to third correction data.

[0018] The first light is, for example, red light; the second light is, for example, green light; and the third light is, for example, blue light.

[0019] The first arithmetic unit may have a function of adjusting the values of the first correction data, the second correction data, and the third correction data respectively to adjust the white balance so that the image displayed on the display unit has an arbitrary color temperature.

Advantages of the Invention

[0020] According to one aspect of the present invention, an image correction system for improving the display quality of a display device can be provided. Or, according to one aspect of the present invention, an image correction method for improving the display quality of a display device can be provided. Or, according to one aspect of the present invention, a novel image correction system can be provided. Or, according to one aspect of the present invention, a novel image correction method can be provided.

Brief Description of the Drawings

[0021] [Figure 1] FIG. 1 is a block diagram for explaining a configuration example of an image correction system. [Figure 2] FIGS. 2(A) and (B) are diagrams showing an arrangement example of a display unit and an imaging device. [Figure 3] FIG. 3 is a flowchart for explaining a method of generating correction data. [Figure 4] FIG. 4(A) is a diagram for explaining the luminance distribution of imaging data. FIG. 4(B) is a diagram for explaining the luminance profile of sub-pixels. [Figure 5] FIG. 5 is a flowchart for explaining a method of correcting a video signal. [Figure 6] FIGS. 6(A) and (B) are diagrams for explaining the emission luminance of three sub-pixels. [Figure 7] FIG. 7 is a flowchart for explaining a method of adjusting correction data. [Figure 8] FIGS. 8(A) to (C) are diagrams showing a configuration example of a display device. [Figure 9] FIGS. 9(A) to (F) are diagrams showing a configuration example of a pixel. [Figure 10] FIG. 10 is a diagram showing a configuration example of a display device. [Figure 11] Figures 11(A) and (B) show examples of the configuration of a display device. [Figure 12] Figures 12(A) and (B) show examples of pixel circuit configurations. [Figure 13] Figures 13(A) through (F) show examples of the configuration of a light-emitting device. [Figure 14] Figures 14(A) and (B) are illustrative images of the luminance distribution. [Figure 15] Figures 15(A) and (B) are illustrative images of the luminance distribution. [Figure 16] Figure 16 is a histogram showing the luminance variation. [Modes for carrying out the invention]

[0022] The embodiments will be described below with reference to the drawings. However, it will be readily apparent to those skilled in the art that the embodiments can be implemented in many different ways, and their form and details can be modified in various ways without departing from the spirit and scope. Therefore, the present invention is not to be construed as being limited to the contents of the following embodiments.

[0023] In this specification, a semiconductor device refers to a device that utilizes semiconductor properties, including circuits containing semiconductor elements (transistors, diodes, photodiodes, etc.), devices having such circuits, etc. It also refers to any device that can function by utilizing semiconductor properties. For example, integrated circuits, chips equipped with integrated circuits, and electronic components with chips housed in packages are examples of semiconductor devices. Furthermore, memory devices, display devices, light-emitting devices, lighting devices, and electronic devices are themselves semiconductor devices, and may also contain semiconductor devices.

[0024] Furthermore, the ordinal numbers "1st," "2nd," and "3rd" in this specification are used to avoid confusion of constituent elements. Therefore, they do not limit the number of constituent elements, nor do they limit the order of the constituent elements. For example, a constituent element referred to as "1st" in one embodiment of this specification may be referred to as "2nd" in another embodiment or in the claims. Also, for example, a constituent element referred to as "1st" in one embodiment of this specification may be omitted in another embodiment or in the claims.

[0025] Furthermore, in this specification, phrases indicating arrangement such as "above," "below," "upward," or "downward" are sometimes used for convenience to explain the positional relationship between components with reference to the drawings. Also, the positional relationship between components changes as appropriate depending on the direction in which each component is depicted. Therefore, the phrases explained in the specification are not limited to those described and can be appropriately rephrased depending on the situation. For example, the expression "insulator located on the upper surface of the conductor" can be rephrased as "insulator located on the lower surface of the conductor" by rotating the orientation of the drawing shown by 180 degrees.

[0026] Furthermore, the terms "above" and "below" do not limit the positional relationship of the components to being directly above or below each other and in direct contact. For example, the expression "electrode B on insulating layer A" does not require electrode B to be formed in direct contact with insulating layer A, and does not exclude cases where other components are included between insulating layer A and electrode B.

[0027] Furthermore, in this specification, terms such as "overlapping" do not limit the state of the stacking order of the components. For example, the expression "electrode B overlapping insulating layer A" does not exclude not only the state in which electrode B is formed on top of insulating layer A, but also the state in which electrode B is formed below insulating layer A or the state in which electrode B is formed to the right (or left) of insulating layer A.

[0028] Furthermore, in this specification, the terms "adjacent" and "proximity" are not limited to direct contact between components. For example, the expression "electrode B adjacent to insulating layer A" does not require that insulating layer A and electrode B be formed in direct contact, and does not exclude cases where other components are included between insulating layer A and electrode B.

[0029] Furthermore, in this specification, terms such as "film" and "layer" can be interchanged as needed. For example, the term "conductive layer" may be changed to the term "conductive film." Or, for example, the term "insulating film" may be changed to the term "insulating layer." Alternatively, depending on the circumstances, terms such as "film" and "layer" can be omitted and replaced with other terms. For example, the term "conductive layer" or "conductive film" may be changed to the term "conductor." Or, the term "conductor" may be changed to the term "conductive layer" or "conductive film." Alternatively, for example, the term "insulating layer" or "insulating film" may be changed to the term "insulator." Or, the term "insulator" may be changed to the term "insulating layer" or "insulating film."

[0030] Furthermore, in this specification, terms such as "electrode," "wiring," and "terminal" do not functionally limit these components. For example, "electrode" may be used as part of "wiring," and vice versa. Moreover, the terms "electrode" or "wiring" include cases where multiple "electrodes" or "wiring" are formed as a single unit. Similarly, for example, "terminal" may be used as part of "wiring" or "electrode," and vice versa. Furthermore, the term "terminal" also includes cases where multiple "electrodes," "wiring," or "terminals" are formed as a single unit. Therefore, for example, an "electrode" can be part of "wiring" or a "terminal," and for example, a "terminal" can be part of "wiring" or an "electrode." In addition, terms such as "electrode," "wiring," and "terminal" may be replaced with terms such as "region" depending on the circumstances.

[0031] Furthermore, in this specification, terms such as "wiring," "signal line," and "power line" can be interchanged with each other depending on the circumstances or situation. For example, the term "wiring" may be changed to the term "signal line." Also, for example, the term "wiring" may be changed to the term "power line." Similarly, the reverse is also true; terms such as "signal line" and "power line" may be changed to the term "wiring." Terms such as "power line" may be changed to the term "signal line." Similarly, the reverse is also true; terms such as "signal line" may be changed to the term "power line." In addition, the term "potential" applied to the wiring may be changed to the term "signal," depending on the circumstances or situation. Similarly, the reverse is also true; terms such as "signal" may be changed to the term "potential."

[0032] In this specification, "parallel" means that two lines are positioned at an angle of -10° or more and 10° or less. Therefore, the case of -5° or more and 5° or less is also included. "Approximately parallel" or "roughly parallel" means that two lines are positioned at an angle of -30° or more and 30° or less. "Perpendicular" means that two lines are positioned at an angle of 80° or more and 100° or less. Therefore, the case of 85° or more and 95° or less is also included. "Approximately perpendicular" or "roughly perpendicular" means that two lines are positioned at an angle of 60° or more and 120° or less.

[0033] In this specification, when count values ​​and measured values ​​are referred to as "identical," "same," "equal," or "uniform" (including synonyms thereof), unless otherwise explicitly stated, this refers to a margin of error of plus or minus 20%.

[0034] In the configuration of the embodiment of the invention, the same reference numerals are used in common across different drawings for parts that are the same or have similar functions, and repeated explanations may be omitted. Also, when referring to similar functions, the hatch patterns may be the same, and no reference numerals may be assigned. Furthermore, in order to make the drawings easier to understand, the description of some components may be omitted in perspective views or top views, etc.

[0035] Furthermore, in the drawings and other illustrations relating to this specification, the size, layer thickness, or area may be exaggerated for clarity. Therefore, it is not necessarily limited to the size or aspect ratio. The drawings are schematic representations of ideal examples and are not limited to the shapes or values ​​shown in the drawings. For example, they may include variations in signals, voltages, or currents due to noise, or variations in signals, voltages, or currents due to timing differences.

[0036] In this specification, when the same code is used for multiple elements, and especially when it is necessary to distinguish them, an identifying code such as "A", "b", "_1", "[n]", or "[m,n]" may be added to the code. For example, multiple subpixels 230 may be shown as subpixel 230R, subpixel 230G, or subpixel 230B.

[0037] (Embodiment 1) An image correction system according to one aspect of the present invention will be described. Figure 1 is a block diagram illustrating the configuration of the image correction system 100.

[0038] <Example of an image correction system configuration> The image correction system 100 includes a display device 110 and a correction data generation device 120.

[0039] [Display device] The display device 110 comprises a display unit 111, a gate driver circuit 112, a source driver circuit 113, a control device 114, an arithmetic unit 115, a storage device 116, and an input / output device 117. The gate driver circuit 112, source driver circuit 113, control device 114, arithmetic unit 115, storage device 116, and input / output device 117 are electrically connected via a bus line 119.

[0040] The display unit 111 has a plurality of pixels 240 arranged in a matrix. The pixels 240 are composed of sub-pixels 230R that emit red light, sub-pixels 230G that emit green light, and sub-pixels 230B that emit blue light. For example, sub-pixel 230R has a light-emitting element that emits red light, sub-pixel 230G has a light-emitting element that emits green light, and sub-pixel 230B has a light-emitting element that emits blue light.

[0041] Full-color display can be achieved by having sub-pixels 230R, 230G, and 230B in pixel 240. Furthermore, the light-emitting colors of the sub-pixels of pixel 240 are not limited to a combination of red (R), green (G), and blue (B), but may also be cyan (C), magenta (M), and yellow (Y). In addition, pixel 240 may have sub-pixels that emit white light. The display unit 111 has the function of displaying an image by writing a video signal VS to each of the sub-pixels 230.

[0042] Note that "sub-pixels" refer to multiple pixels included in a pixel that enables color display. On the other hand, in monochrome displays and other single-color displays, there is no need to distinguish between pixels and sub-pixels. Therefore, unless explicitly stated, "pixels" and "sub-pixels" can be used interchangeably.

[0043] Furthermore, by arranging 240 pixels in a 1920 x 1080 matrix, a display device 110 capable of full-color display at a resolution known as Full HD (also called "2K resolution," "2K1K," or "2K"). Also, for example, by arranging 240 pixels in a 3840 x 2160 matrix, a display device 110 capable of full-color display at a resolution known as Ultra HD (also called "4K resolution," "4K2K," or "4K"). Furthermore, for example, by arranging 240 pixels in a 7680 x 4320 matrix, a display device 110 capable of full-color display at a resolution known as Super Hi-Vision (also called "8K resolution," "8K4K," or "8K"). By increasing the number of pixels, it is also possible to realize a display device 110 capable of full-color display at a resolution of 16K or 32K.

[0044] The control device 114 has the function of controlling the operation of the gate driver circuit 112, source driver circuit 113, arithmetic unit 115, storage unit 116, and input / output device 117 according to the program held in the storage device 116. For example, a CPU (Central Processing Unit) may be used as the control device 114.

[0045] The storage device 116 has the function of storing programs and operating parameters related to the operation of the display device 110. As the storage device 116, volatile storage devices such as DRAM (Dynamic Random Access Memory) and SRAM (Static Random Access Memory) can be used. Alternatively, as the storage device 116, non-volatile storage devices such as EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), flash memory, MRAM (Magnetoresistive Random Access Memory), PRAM (Phase change RAM), ReRAM (Resistive RAM), and FeRAM (Ferroelectric RAM) can be used. It is preferable that at least a portion of the storage device 116 is a rewritable non-volatile storage device.

[0046] As the memory device 116, a DOSRAM (registered trademark) using a transistor having an oxide semiconductor in the channel formation region (also called an "OS transistor") may be used. Since DOSRAM can be composed of one transistor and one capacitor, it is possible to achieve high memory density. In addition, because the OS transistor has an extremely low off-current, the data refresh period can be extended.

[0047] Furthermore, NOSRAM (registered trademark) may be used as the memory device 116. NOSRAM consists of two transistors and one capacitor, and since data is rewritten by charging and discharging the capacitor, in principle there is no limit to the number of rewrites, and data can be written and read with low energy. NOSRAM can also store multi-level data. By making the data held (stored) in one memory cell three or more levels, the storage capacity per memory cell can be increased compared to DOSRAM.

[0048] A memory cell containing an OS transistor can be called an "OS memory." Similarly, a storage device containing such a memory cell can also be called an "OS memory." Because OS transistors have extremely low off-current, OS memory can retain data for extended periods even when the power supply is interrupted.

[0049] Furthermore, the video signal VS supplied from an external source and the operating parameters of the display device 110 are stored in the storage device 116 via the input / output device 117. The display device 110 operates according to these operating parameters. The input / output device 117 also has the function of outputting signals such as the operating status of the display device 110 to the outside.

[0050] Furthermore, the correction data supplied from the correction data generation device 120 is stored in the storage device 116 via the input / output device 117. The correction data will be explained in more detail later.

[0051] The arithmetic unit 115 has the function of performing various signal processing on the video signal VS according to the operating parameters of the display device 110. For example, the arithmetic unit 115 has the function of performing brightness (luminance) correction, contrast correction, color tone correction, and gamma correction on the video signal VS. The arithmetic unit 115 may be a CPU or a GPU (Graphics Processing Unit).

[0052] Furthermore, the arithmetic unit 115 may perform signal processing such as removing noise components from the video signal VS, contour enhancement correction, upconversion, or downconversion. In addition, if upconversion or downconversion is performed on the video signal VS, a super-resolution circuit (not shown) may be provided in the display device 110.

[0053] The super-resolution circuit has a function to upconvert the video signal VS if its resolution is lower than the resolution of the display unit 111. The super-resolution circuit also has a function to downconvert the video signal VS if its resolution is higher than the resolution of the display unit 111. The super-resolution circuit also has a function to determine which video signal to supply to any pixel of the display unit 111 is supplied to by a sum-of-products operation of weights with the video signals supplied to the surrounding pixels.

[0054] By incorporating a super-resolution circuit, the load on the computing unit 115 can be reduced. For example, the computing unit 115 can process up to 2K resolution (or 4K resolution), and then the super-resolution circuit can upconvert to 4K resolution (or 8K resolution), thereby reducing the load on the computing unit 115. Downconversion can be performed in the same manner.

[0055] Furthermore, the arithmetic unit 115 has a function to perform signal processing (also called "correction processing") to correct the video signal VS for each pixel using correction data stored in the memory device 116. The correction processing reduces brightness variations and display unevenness within the display unit 111. As a result, the display quality of the display device 110 is improved.

[0056] The various correction processes performed by the arithmetic unit 115 are preferably performed using digital signals. The arithmetic unit 115 has a function to convert the digital video signal VS into an analog signal after the necessary correction processes are completed. The video signal VS converted into an analog signal is supplied to the display unit 111 via the source driver circuit 113. The gate driver circuit 112 and the source driver circuit 113 have a function to write the video signal VS to the pixels 240 of the display unit 111. Alternatively, the video signal VS may be supplied to the source driver circuit 113 as a digital signal, and the source driver circuit 113 may convert the video signal VS into an analog signal. In this way, an image can be displayed on the display unit 111.

[0057] [Correction data generation device] The correction data generation device 120 includes an imaging device 121, a control device 124, a calculation device 125, a storage device 126, and an input / output device 127. The imaging device 121, control device 124, calculation device 125, storage device 126, and input / output device 127 are electrically connected via a bus line 129.

[0058] The control device 124 has the function of controlling the operation of the imaging device 121, the arithmetic unit 125, the storage device 126, and the input / output device 127 according to the program stored in the storage device 126. Similar to the control device 114, a CPU may be used as the control device 124. Also, a CPU or GPU may be used as the arithmetic unit 125.

[0059] The imaging device 121 has the function of capturing the image displayed on the display unit 111 and acquiring imaging data. Therefore, the imaging data includes a two-dimensional luminance distribution. In other words, the imaging device 121 has the function of acquiring the luminance distribution of the image displayed on the display unit 111 as two-dimensional information.

[0060] Figure 2(A) shows a schematic perspective view of the display unit 111 and the imaging device 121. The brightness distribution of the display unit 111 can be obtained by capturing the image displayed on the display unit 111 with the imaging device 121. The imaging device 121 can be an image sensor or a luminance meter, etc.

[0061] The resolution of the imaging device 121 is preferably greater than the resolution of the display unit 111. The resolution of the imaging device 121 is preferably four times or more than the resolution of the display unit 111, and more preferably nine times or more. Furthermore, as shown in Figure 2(B), if the display unit 111 is larger than the shooting range of the imaging device 121, if the resolution of the imaging device 121 is smaller than the resolution of the display unit 111, or if it is desired to image the display unit 111 with greater accuracy, the shooting range of the imaging device 121 can be made smaller than the display unit 111, and the display unit 111 can be scanned while shooting.

[0062] When scanning the display unit 111 with the imaging device 121 while taking a picture, either the display unit 111 or the imaging device 121 may be moved, or both may be moved.

[0063] The arithmetic unit 125 has the function of acquiring luminance data for each pixel using the acquired luminance distribution. By comparing the obtained luminance data for each pixel with the video signal, correction data for each pixel is calculated. At this time, it is preferable that the image displayed on the display unit 111 is a single color. Also, in order to obtain an accurate luminance distribution, it is preferable to supply the same luminance data to all pixels. A CPU or GPU may be used as the arithmetic unit 125.

[0064] For example, a video signal VS with a single color and the same brightness data (gradation) for all pixels is supplied as a correction video signal AS to both the display device 110 and the correction data generation device 120. The correction video signal AS may be supplied to the correction data generation device 120 via the display device 110. Alternatively, the correction video signal AS may be supplied to the display device 110 via the correction data generation device 120.

[0065] The image displayed on the display unit 111 using the correction video signal AS is captured by the imaging device 121, and luminance data for each pixel is acquired. By comparing the acquired luminance data for each pixel with the correction video signal AS, correction data for each pixel can be calculated.

[0066] The storage device 126 has the function of storing programs and operating parameters related to the operation of the correction data generation device 120. It also has the function of storing imaging data acquired by the imaging device 121, calculation results from the arithmetic unit 125, and correction data for each pixel. The storage device 126 can be the same type of storage device as the storage device 116.

[0067] Furthermore, the correction video signal AS supplied from an external source and the operating parameters of the correction data generation device 120 are stored in the storage device 126 via the input / output device 127. The correction data generation device 120 operates according to these operating parameters. The input / output device 127 also has the function of outputting signals such as the operating status of the correction data generation device 120 to the outside.

[0068] The correction data for each pixel generated by the correction data generation device 120 is supplied to the input / output device 117 of the display device 110 via the input / output device 127 and stored in the storage device 116.

[0069] It should be noted that the configuration of the image correction system 100 according to one aspect of the present invention is not limited to the configuration shown in this embodiment. The image correction system 100 according to one aspect of the present invention may not have some of the configurations shown in this embodiment, and may have configurations not shown in this embodiment.

[0070] Furthermore, a normally-off CPU (also known as "NoffCPU" (registered trademark)) may be used as the CPU in the image correction system 100 according to one aspect of the present invention. The NoffCPU can stop supplying power to circuits within the NoffCPU that do not need to operate, and put those circuits into a standby state. Power is not consumed in circuits that are in a standby state because the power supply has been stopped. Therefore, the NoffCPU can minimize power consumption.

[0071] Furthermore, it is preferable to use OS memory as the storage device for the cache and registers provided by the NoffCPU. OS memory can retain information for a long period of time even if the power supply is interrupted. By storing (memorizing) information such as operating parameters in OS memory, the recovery of a standby circuit within the NoffCPU only requires the restoration of power supply to that circuit, and there is no need to rewrite the operating parameters. In other words, high-speed recovery from standby is possible. In this way, the NoffCPU can reduce power consumption without significantly reducing its operating speed.

[0072] Furthermore, a normally-off GPU (also known as "NoffGPU" (registered trademark)) may be used as the GPU in the image correction system 100 according to one aspect of the present invention. Like the NoffCPU, the NoffGPU can stop supplying power to circuits that are not in operation, and put those circuits into a standby state.

[0073] Furthermore, similar to the NoffCPU, the NoffGPU utilizes OS memory as storage for its cache and registers, enabling fast recovery from standby mode. Therefore, the NoffGPU can reduce power consumption without significantly slowing down its operating speed.

[0074] <Example of image correction system operation> Next, we will explain the operation of the image correction system 100.

[0075] [Generating Correction Data] First, an example of the operation of the correction data generation device 120 will be described. In this embodiment, an example of generating correction data using the correction data generation device 120 will be described. Here, the method of acquiring correction data for the sub-pixels 230R of the display unit 111 will be mainly explained. Figure 3 shows a flowchart illustrating the operation of the correction data generation device 120.

[0076] [Step S501] The correction video signal AS is supplied to all sub-pixels 230R of the display unit 111, causing all sub-pixels 230R to emit light, and the imaging device 121 captures the brightness distribution of the display unit 111. The acquired imaging data is stored in the storage device 126. At this time, the correction video signal AS is changed from the first correction video signal AS1 to the second correction video signal AS2 during imaging.

[0077] The correction video signal AS is a signal that indicates the value of the gradation. Therefore, the first correction video signal AS1 is sometimes referred to as the "first gradation," and the second correction video signal AS2 is sometimes referred to as the "second gradation." For example, the first correction video signal AS1 is a gradation in which the sub-pixel 230R emits light at low brightness, and the second correction video signal AS2 is a gradation in which the sub-pixel 230R emits light at high brightness. The first correction video signal AS1 does not need to be the minimum gradation (minimum brightness), and the second correction video signal AS2 does not need to be the maximum gradation (maximum brightness).

[0078] [Step S502] Next, the position and area S of all subpixels 230R on the imaging data are determined using the imaging data acquired in step S501. The position can be determined using the luminance distribution on the imaging data in any correction video signal AS. The position and area S of all subpixels 230R can be determined from the periodicity of multiple luminance peaks that repeatedly appear within the luminance distribution.

[0079] As an example, Figure 4(A) shows a diagram illustrating the luminance distribution obtained by cutting out a portion of the imaging data in an arbitrary direction. In Figure 4(A), the horizontal axis represents distance and the vertical axis represents luminance. Although Figure 4(A) shows a one-dimensional luminance distribution, by examining the position and occurrence period of the repeatedly appearing peak 131 in the imaging data, the position and area S of each subpixel 230R in the imaging data can be determined.

[0080] The position and area S of each sub-pixel 230R in the imaging data do not need to be precise. The position of each sub-pixel 230R only needs to be determined so that the arrangement of all sub-pixels 230R on the display unit 111 can be roughly identified. The area S of each sub-pixel 230R can be the same value used for all sub-pixels 230R, as long as the area occupied by one sub-pixel 230R does not interfere with adjacent sub-pixels 230R. For example, any value can be used for the area S. For example, if the arrangement and area of ​​all sub-pixels 230R on the display unit 111 are known, those values ​​can be used for the position and area S of the sub-pixels 230R in the imaging data.

[0081] Depending on the performance of the optical components of the imaging device 121 and the imaging conditions, distortion or tilt may occur in the brightness distribution on the imaging data. To facilitate the determination of the position and area S of the sub-pixels 230R, it is preferable to have less distortion or tilt in the brightness distribution on the imaging data. If the distortion or tilt of the brightness distribution on the imaging data is large, calculation processing may be performed to adjust for these.

[0082] Alternatively, the position and area S of the sub-pixel 230R may be determined by image processing using AI (Artificial Intelligence) technology.

[0083] [Step S503] The light emitted by sub-pixel 230R is not necessarily uniform within area S. Therefore, the integral value of the luminance within area S is calculated using the acquired luminance distribution. Since luminance is the luminous intensity per unit area, this integral value can be said to be the luminous intensity per sub-pixel 230R. In other words, luminance is the value obtained by dividing the luminous intensity of one sub-pixel 230R by its area S. Therefore, if the area S of all sub-pixels 230 on the display unit 111 is the same, "luminance" and "luminous intensity" may be interchangeable.

[0084] For all sub-pixels 230R, the change in brightness (luminosity change) of sub-pixels 230R with respect to the correction video signal AS is calculated when the correction video signal AS is changed from the first correction video signal AS1 to the second correction video signal AS2.

[0085] As an example, Figure 4(B) shows a diagram illustrating the calculation result of the brightness change of a sub-pixel 230R in relation to the correction video signal AS of a single sub-pixel 230R (also called the "brightness profile"), which is referred to as brightness profile 251R_1. In Figure 4(B), the horizontal axis represents the correction video signal AS, and the vertical axis represents brightness. As mentioned above, the correction video signal AS is also a signal that indicates the gradation value. Therefore, the horizontal axis in Figure 4(B) may be read as "gradation" or "gradation value".

[0086] Furthermore, in this embodiment, since the area S of all sub-pixels 230 is the same, the vertical axis in Figures 4(A) and (B) may be read as "luminosity." Therefore, "luminance profile" may be read as "luminosity profile."

[0087] Furthermore, if the correction video signal AS is a voltage, the horizontal axis in Figure 4(B) may be read as "voltage." Therefore, the first correction video signal AS1 can be called the first voltage, and the second correction video signal AS2 can be called the second voltage.

[0088] [Step S504] Next, the target luminance change (luminosity change) for correction is determined. In this embodiment, the target luminance change (luminosity change) for correction is also called the "correction standard" or "correction standard profile."

[0089] For example, when the correction video signal AS is the first correction video signal AS1, the luminance profile of the sub-pixel 230R with the highest luminance may be used as the correction reference profile. Alternatively, when the correction video signal AS is the first correction video signal AS1, the luminance profile of the sub-pixel 230R with an average or near-average luminance may be used as the correction reference profile. Alternatively, when the correction video signal AS is the first correction video signal AS1, the luminance profile of the sub-pixel 230R with a median or near-median luminance may be used as the correction reference profile. Furthermore, a separate correction reference profile may be set without using the luminance profile of the sub-pixel 230R. As an example, Figure 4(B) shows a diagram illustrating the correction reference profile 251R_S.

[0090] [Step S505] Next, in order to correct the luminance profile of the first sub-pixel 230R (also called "luminance profile 251R_1") to match the correction reference profile 251R_S, the first correction data CVR (also called "correction data CVR_1") is calculated. Specifically, the correction data CVR, which is the difference between the correction reference profile 251R_S and the luminance profile 251R_1, is calculated.

[0091] The correction data CVR is calculated for each of the sub-pixels 230R. Preferably, the correction data CVR is calculated for all gradations from the first correction video signal AS1 (first gradation) to the second correction video signal AS2 (second gradation). However, the correction data CVR may not be calculated for all gradations, but rather at regular intervals of a certain number of gradations. Also, for example, if the correction reference profile 251R_S and the luminance profile 251R_1 are both considered to be straight lines and have the same or approximately the same slope, then the value calculated for the first gradation may be used as the correction data CVR_1 for all gradations.

[0092] Alternatively, the average value of the correction data CVR of multiple adjacent subpixels 230R may be used as a common correction data CVR among multiple adjacent subpixels 230R. By doing so, the storage capacity required to hold the correction data CVR is reduced, and the load on storage devices 116 and 126 can be reduced. Therefore, the power consumption of the display device 110 and the correction data generation device 120 can be reduced.

[0093] Alternatively, a histogram may be created using the luminance distribution acquired in step S501, and the correction data CVR may be calculated only for the sub-pixels 230R that fall outside the reference range. By doing so, the storage capacity required to hold the correction data CVR is reduced, and the load on storage devices 116 and 126 can be reduced. Therefore, the power consumption of the display device 110 and the correction data generation device 120 can be reduced.

[0094] [Step S506] Next, the calculated correction data CVR is stored in the storage device 126.

[0095] [Step S507] If the correction data CVG, which is the correction value for sub-pixel 230G, has not been calculated, the sub-pixel 230R and correction data CVR shown in steps S501 to S506 are replaced with sub-pixel 230G and correction data CVG, and steps S501 to S506 are performed.

[0096] [Step S508] If the correction data CVB, which is the correction value for sub-pixel 230B, has not been calculated, the sub-pixel 230R and correction data CVR shown in steps S501 to S506 are replaced with sub-pixel 230B and correction data CVB, and steps S501 to S506 are performed.

[0097] [Step S509] The correction data CVR, correction data CVG, and correction data CVB stored in the storage device 126 are supplied to the display device 110 and stored in the storage device 116. In this specification, the correction data CVR, correction data CVG, and correction data CVB may be collectively referred to as "correction data CV".

[0098] The configuration and method illustrated in this embodiment can generate correction data CVR, correction data CVG, and correction data CVG for each sub-pixel.

[0099] Furthermore, if the imaging device 121 can acquire the brightness distributions of red light, green light, and blue light separately, step S501 may be performed by simultaneously emitting light from the sub-pixels 230R, 230G, and 230B of the pixel 240.

[0100] By simultaneously acquiring the luminance distribution of each of the sub-pixels 230 (sub-pixels 230R, 230G, and 230B), the calculation of the correction data CV (correction data CVR, correction data CVG, and correction data CVG) performed in steps S502 to S506 can be done in parallel. Therefore, steps S507 and S508 can be omitted. By simultaneously acquiring the luminance distribution of each of the sub-pixels 230, the calculation time for the correction data CV can be shortened.

[0101] According to an image correction system in one aspect of the present invention, brightness variations and display unevenness within the display unit 111 are reduced, and the display quality of the display device 110 is improved.

[0102] It should be noted that the method for generating correction data according to one aspect of the present invention is not limited to the configuration shown in this embodiment. The method for generating correction data according to one aspect of the present invention may not have some of the configurations shown in this embodiment, and may have configurations not shown in this embodiment.

[0103] [Video Signal Correction] Next, an example of the operation of the display device 110 will be described. In this embodiment, an example of video signal correction in the display device 110 will be described. Figure 5 shows a flowchart illustrating the operation of the display device 110.

[0104] [Step S511] The video signal VS supplied to the display device 110 via the input / output device 117 is stored in the storage device 116.

[0105] [Step S512] The system determines whether the resolution of the video signal VS differs from the resolution of the display unit 111. If the resolutions of the two differ, the system performs step S513. If the resolutions of the two differ, the system performs step S515.

[0106] [Step S513] The arithmetic unit 115 performs a correction to match the resolution of the video signal VS to the resolution of the display unit 111. This correction to match the resolution may be performed by upconversion or downconversion. If the resolution of the video signal VS is greater than the resolution of the display unit 111, data in areas that cannot be displayed on the display unit 111 may be deleted from the video signal VS. If the resolution of the video signal VS is less than the resolution of the display unit 111, arbitrary data may be added to the video signal VS.

[0107] [Step S514] The corrected video signal VS is stored in the memory device 116.

[0108] [Step S515] Next, based on the operating parameters stored in the memory device 116, it is determined whether or not to correct the video signal VS using the correction data CV. If the video signal VS is to be corrected using the correction data CV, step S516 is performed. If the video signal VS is not to be corrected, step S518 is performed.

[0109] [Step S516] In the arithmetic unit 115, the video signal VS is corrected pixel by pixel using the correction data CV stored in the memory device 116. More specifically, the gradation of all sub-pixels 230R in the video signal VS is corrected with the correction data CVR corresponding to each sub-pixel 230R. Similarly, the gradation of all sub-pixels 230G in the video signal VS is corrected with the correction data CVG corresponding to each sub-pixel 230G. Similarly, the gradation of all sub-pixels 230B in the video signal VS is corrected with the correction data CVB corresponding to each sub-pixel 230B.

[0110] [Step S517] The video signal VS, corrected using the correction data CV, is stored in the storage device 116.

[0111] [Step S518] Next, based on the operating parameters stored in the memory device 116, it is determined whether or not to perform brightness correction, contrast correction, color correction, gamma correction, removal of noise components from the video signal VS, or edge enhancement correction on the corrected video signal VS.

[0112] For example, in step S518, it is determined whether or not to perform contrast correction on the corrected video signal VS based on the operating parameters stored in the storage device 116. If contrast correction is to be performed, step S519 is performed. If contrast correction is not to be performed, step S521 is performed.

[0113] [Step S519] The arithmetic unit 115 performs contrast correction on the video signal VS.

[0114] [Step S520] The video signal VS corrected in step S519 is stored in the storage device 116.

[0115] In this embodiment, contrast correction was used as an example to explain steps S518 to S520, but other corrections can be performed in the same manner.

[0116] [Step S521] The image is displayed on the display unit 111 using the video signal VS, which has undergone the necessary correction processing. In this way, the necessary correction processing is applied to the video signal VS, and the image can be displayed on the display unit 111 using the corrected video signal VS. By performing the correction processing, high-quality image display can be achieved. Therefore, a display device 110 with high display quality can be realized.

[0117] Furthermore, the video signal correction method according to one aspect of the present invention is not limited to the configuration shown in this embodiment. The video signal correction method according to one aspect of the present invention may not have some of the configurations shown in this embodiment, and may have configurations not shown in this embodiment.

[0118] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0119] (Embodiment 2) This embodiment describes the adjustment of correction data CV (correction data CVR, correction data CVG, and correction data CVB) that takes into account the color temperature when displaying white.

[0120] The display unit 111 displays an image of the video signal VS that has been corrected using the correction data CV. When the video signal VS is a signal that displays white, it may not be possible to obtain a white display with the desired color temperature. This is because the difference in the luminescence of each of the sub-pixels 230R, 230G, and 230B causes a shift in color temperature. One reason for this is that by calculating the correction data CVR, correction data CVG, and correction data CFB individually, a shift occurs in the color temperature of the video signal VS corrected using the correction data CV.

[0121] As an example, Figure 6(A) shows a diagram illustrating the luminance profile of sub-pixel 230R corrected with correction data CVR (luminance 252R), the luminance profile of sub-pixel 230G corrected with correction data CVG (luminance 252G), and the luminance profile of sub-pixel 230B corrected with correction data CVB (luminance 252B).

[0122] Here, assuming that the peak brightness (maximum brightness) of the three brightness profiles is the same, resulting in a white display at the desired color temperature, Figure 6(A) illustrates that the desired white display at the desired color temperature is not achieved.

[0123] Adjusting the emission luminance of red, green, and blue light to obtain white light with a desired color temperature (which may be read as "white balance") is also called "adjusting the white balance" or "adjusting the color balance." White balance adjustment can be performed by the arithmetic unit 115. However, if the color temperature of the video signal VS corrected using the correction data CV is too biased, the arithmetic unit 115 may not be able to fully adjust the color temperature.

[0124] Therefore, in addition to the above embodiment, it is preferable to modify the correction data CV considering white balance using the correction data generation device 120. In this embodiment, the modification of correction data CVR, correction data CVG, and correction data CVB considering white balance will be described. Figure 7 shows a flowchart illustrating the method for modifying correction data considering white balance.

[0125] White balance adjustment can be performed using the imaging data (luminance distribution) stored in the memory device 126 in step S501, along with the correction data CVR, correction data CVG, and correction data CVG.

[0126] [Step S531] First, the brightness of the sub-pixel 230R acquired in step S501 is corrected with the correction data CVR to calculate the brightness 252R. Brightness 252R is calculated for all sub-pixels 230R. Alternatively, brightness 252R may be calculated using the average value of the brightness of multiple or all sub-pixels 230R.

[0127] [Step S532] Next, the brightness of the sub-pixel 230G acquired in step S501 is corrected with the correction data CVG to calculate the brightness 252G. Brightness 252G is calculated for all sub-pixels 230G. Alternatively, brightness 252G may be calculated using the average value of the brightness of multiple or all sub-pixels 230G.

[0128] [Step S533] Next, the brightness of the subpixel 230B acquired in step S501 is corrected with the correction data CVB to calculate the brightness 252B. Brightness 252B is calculated for all subpixels 230B. Alternatively, brightness 252B may be calculated using the average value of the brightness of multiple or all subpixels 230B.

[0129] [Step S534] The storage device 126 holds color temperature data for realizing white light of a specific color temperature. The arithmetic unit 125 compares the color temperature data with luminance 252R, luminance 252G, and luminance 252B, and corrects the values ​​of correction data CVR, correction data CVG, and correction data CVG as necessary.

[0130] Color temperature is often adjusted within the range of 2000K (Kelvin) to 8000K. Therefore, the color temperature data stored in the memory device 126 only needs to be data that reproduces white light with a color temperature between 4000K and 6000K.

[0131] [Step S535] Correction data CVR, correction data CVG, and correction data CVG, which are corrected using color temperature data, are stored in the storage device 126.

[0132] [Step S536] The correction data CVR, correction data CVG, and correction data CVB held in the storage device 126 are supplied to the display device 110 and stored in the storage device 116.

[0133] In this way, the white balance can be adjusted. Figure 6(B) shows an example illustrating brightness levels 252R, 252G, and 252B after white balance adjustment.

[0134] By adjusting the correction data CVR, CVG, and CVG to account for white balance, more natural-looking color images can be displayed. Therefore, the display quality of the display device can be further improved. Note that Figure 6(B) illustrates the results of adjusting the correction data CVR, CVG, and CVG so that the maximum brightness of brightness 252R, brightness 252G, and brightness 252B are equal, but this is not the only example. The brightness of brightness 252R, brightness 252G, and brightness 252B will vary depending on the set color temperature.

[0135] The correction data CVR, CVG, and CVG for adjusting the color balance may be performed for all gradations from the first correction video signal AS1 to the second correction video signal AS2, or the correction value obtained for any gradation of the correction video signal AS may be used as the correction value for all gradations from the first correction video signal AS1 to the second correction video signal AS2.

[0136] It should be noted that the white balance adjustment method according to one aspect of the present invention is not limited to the configuration shown in this embodiment. The white balance adjustment method according to one aspect of the present invention may not have some of the configurations shown in this embodiment, and may have configurations not shown in this embodiment.

[0137] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0138] (Embodiment 3) This embodiment describes an example configuration of a display device 200 that can be used with the display device 110.

[0139] The display device shown in this embodiment is a display device having light-emitting elements (also called light-emitting devices). The display device has two or more light-emitting elements that emit light of different colors. Each light-emitting element has a pair of electrodes and an EL layer between them. The light-emitting elements are preferably organic EL elements (organic electroluminescent elements). The two or more light-emitting elements that emit different colors each have an EL layer containing a different light-emitting material. For example, a full-color display device can be realized by having three types of light-emitting elements that emit red (R), green (G), or blue (B) light, respectively.

[0140] When manufacturing a display device with multiple light-emitting elements, each with a different emission color, it is necessary to form separate island-shaped layers containing light-emitting materials with different emission colors (light-emitting layers). When manufacturing part or all of the EL layer separately, a method of forming island-shaped organic films using a vapor deposition method with a shadow mask such as a metal mask is known. However, with this method, deviations from the design occur in the shape and position of the island-shaped organic films due to various factors such as the precision of the metal mask, the misalignment between the metal mask and the substrate, the deflection of the metal mask, and the spreading of the contour of the deposited film due to vapor scattering, making it difficult to achieve high resolution and high aperture ratio. In addition, during vapor deposition, the contour of the layer may become blurred, and the thickness at the edges may become thinner. In other words, the thickness of the island-shaped light-emitting layers may vary depending on the location. Furthermore, when manufacturing large, high-resolution, or high-definition display devices, there are concerns that the manufacturing yield will be low due to the low dimensional accuracy of the metal mask and deformation due to heat, etc. For this reason, measures have been taken to artificially increase the resolution (also called pixel density) by adopting special pixel arrangement methods such as PenTile arrangements.

[0141] In this specification, "island-like" refers to a state in which two or more layers made of the same material and formed in the same process are physically separated. For example, an island-like light-emitting layer refers to a state in which the light-emitting layer and an adjacent light-emitting layer are physically separated.

[0142] One aspect of the present invention involves processing the EL layer into a fine pattern by photolithography without using a shadow mask such as a fine metal mask (FMM). This makes it possible to realize a display device with high resolution and a large aperture ratio, which has been difficult to achieve until now. Furthermore, since the EL layer can be differentiated, it is possible to realize a display device with extremely vivid colors, high contrast, and high display quality. For example, the EL layer may be processed into a fine pattern using both a metal mask and photolithography.

[0143] Furthermore, part or all of the EL layer can be physically separated. This suppresses leakage current between light-emitting elements via a common layer (also called a common layer) used between adjacent light-emitting elements. This prevents crosstalk caused by unintended light emission, enabling the realization of a display device with extremely high contrast. In particular, it enables the realization of a display device with high current efficiency at low brightness levels.

[0144] One aspect of the present invention is a display device that combines a white-emitting light-emitting element with a color filter. In this case, the same configuration of light-emitting elements can be applied to the light-emitting elements provided in pixels (sub-pixels) that emit light of different colors, and all layers can be made into a common layer. Furthermore, part or all of each EL layer is separated by photolithography. This suppresses leakage current through the common layer, enabling the realization of a display device with high contrast. In particular, in an element having a tandem structure in which multiple light-emitting layers are stacked with a highly conductive intermediate layer in between, leakage current through the intermediate layer can be effectively prevented, thus enabling the realization of a display device that combines high brightness, high resolution, and high contrast.

[0145] Furthermore, it is preferable to provide an insulating layer that covers at least the sides of the island-shaped light-emitting layer. The insulating layer may be configured to cover a portion of the upper surface of the island-shaped EL layer. It is preferable to use a material that has barrier properties against water and oxygen as the insulating layer. For example, an inorganic insulating film that does not easily diffuse water or oxygen can be used. This suppresses the degradation of the EL layer and enables the realization of a highly reliable display device.

[0146] Furthermore, between two adjacent light-emitting elements, there is a region (recess) where neither light-emitting element has an EL layer. When a common electrode, or a common electrode and common layer, is formed to cover this recess, a phenomenon called "step break" may occur where the common electrode is separated by a step at the edge of the EL layer, and the common electrode on the EL layer may become insulated. Therefore, it is preferable to use a configuration (LFP: Local Filling Planarization) in which the local step located between two adjacent light-emitting elements is filled with a resin layer that functions as a planarizing film. This resin layer has the function of a planarizing film. This suppresses step breaks in the common layer or common electrode, and enables the realization of a highly reliable display device.

[0147] In the following section, a more specific configuration example of the display device 200 will be described with reference to the drawings.

[0148] Figure 8(A) shows a schematic top view of the display device 200. The display device 200 has multiple red-emitting light-emitting elements 210R, green-emitting light-emitting elements 210G, and blue-emitting light-emitting elements 210B on a substrate 201. The light-emitting elements 210 correspond to the light-emitting elements of the sub-pixels 230 shown in the above embodiment. In Figure 8(A), the labels R, G, and B are added within the light-emitting area of ​​each light-emitting element to simplify the distinction between them.

[0149] The light-emitting elements 210R, 210G, and 210B are each arranged in a matrix. Figure 8(A) shows a so-called stripe arrangement, in which light-emitting elements of the same color are arranged in one direction. However, the arrangement method of the light-emitting elements is not limited to this, and other arrangement methods such as S-stripe arrangement, delta arrangement, Bayer arrangement, and zigzag arrangement may be applied, or a pentile arrangement or diamond arrangement may be used.

[0150] For the light-emitting elements 210R, 210G, and 210B, it is preferable to use, for example, OLED (Organic Light Emitting Diode) or QLED (Quantum-dot Light Emitting Diode). Examples of light-emitting materials for the EL element include fluorescent materials, phosphorescent materials, inorganic compounds (such as quantum dot materials), and thermally activated delayed fluorescence (TADF) materials.

[0151] Figure 8(A) also shows a connecting electrode 219 that is electrically connected to the common electrode 213. The connecting electrode 219 is supplied with a potential (e.g., anode potential or cathode potential) to the common electrode 213. The connecting electrode 219 is located outside the display area where the light-emitting elements 210R and the like are arranged.

[0152] The connecting electrode 219 can be provided along the outer perimeter of the display area. For example, it may be provided along one side of the outer perimeter of the display area, or it may be provided across two or more sides of the outer perimeter of the display area. That is, if the top surface shape of the display area is rectangular, the top surface shape of the connecting electrode 219 can be a strip (rectangle), L-shape, U-shape (square bracket shape), or quadrilateral, etc.

[0153] Figures 8(B) and 8(C) are schematic cross-sectional views corresponding to the dashed-dotted lines A1-A2 and A3-A4 in Figure 8(A), respectively. Figure 8(B) shows schematic cross-sectional views of the light-emitting element 210R, light-emitting element 210G, and light-emitting element 210B, while Figure 8(C) shows schematic cross-sectional views of the connection portion 140 to which the connecting electrode 219 and the common electrode 213 are connected.

[0154] The light-emitting element 210R has a pixel electrode 211R, an organic layer 212R, a common layer 214, and a common electrode 213. The light-emitting element 210G has a pixel electrode 211G, an organic layer 212G, a common layer 214, and a common electrode 213. The light-emitting element 210B has a pixel electrode 211B, an organic layer 212B, a common layer 214, and a common electrode 213. The common layer 214 and the common electrode 213 are provided in common to the light-emitting elements 210R, 210G, and 210B.

[0155] The organic layer 212R of the light-emitting element 210R contains a luminescent organic compound that emits light with intensity in at least the red wavelength range. The organic layer 212G of the light-emitting element 210G contains a luminescent organic compound that emits light with intensity in at least the green wavelength range. The organic layer 212B of the light-emitting element 210B contains a luminescent organic compound that emits light with intensity in at least the blue wavelength range. The organic layers 212R, 212G, and 212B can also be called EL layers and each contains a layer (luminescent layer) that contains at least a luminescent organic compound.

[0156] In the following, when describing matters common to the light-emitting element 210R, light-emitting element 210G, and light-emitting element 210B, they may be referred to simply as light-emitting element 210. Similarly, for components distinguished by letters, such as organic layer 212R, organic layer 212G, and organic layer 212B, when describing matters common to them, the letters may be omitted and symbols used.

[0157] The organic layer 212 and the common layer 214 can each independently have one or more of the following: an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer. For example, the organic layer 212 can have a stacked structure of a hole injection layer, a hole transport layer, an emissive layer, and an electron transport layer from the pixel electrode 211 side, and the common layer 214 can have an electron injection layer.

[0158] Pixel electrodes 211R, 211G, and 211B are provided for each light-emitting element. A common electrode 213 and a common layer 214 are provided as a continuous layer common to each light-emitting element. A conductive film that is transparent to visible light is used on either each pixel electrode or the common electrode 213, and a conductive film that is reflective is used on the other. By making each pixel electrode transparent and the common electrode 213 reflective, a bottom-emission type display device can be made. Conversely, by making each pixel electrode reflective and the common electrode 213 transparent, a top-emission type display device can be made. Furthermore, by making both each pixel electrode and the common electrode 213 transparent, a dual-emission type display device can be made.

[0159] A protective layer 215 is provided on the common electrode 213, covering the light-emitting elements 210R, 210G, and 210B. The protective layer 215 has the function of preventing impurities such as water from diffusing to each light-emitting element from above.

[0160] It is preferable that the end of the pixel electrode 211 has a tapered shape. When the end of the pixel electrode has a tapered shape, the organic layer 212 provided along the side surface of the pixel electrode also has a tapered shape. By making the side surface of the pixel electrode tapered, the coverage of the EL layer provided along the side surface of the pixel electrode can be improved. Furthermore, making the side surface of the pixel electrode tapered makes it easier to remove foreign matter (for example, dust or particles) during the manufacturing process by washing or other processes, which is preferable.

[0161] In this specification, a tapered shape refers to a shape in which at least a portion of the side surface of a structure is inclined relative to the bottom surface of the structure. For example, it is preferable to have a region in which the angle between the inclined side surface and the bottom surface (also called the taper angle) is less than 90°.

[0162] The organic layer 212 is processed into island-like structures using photolithography. As a result, the organic layer 212 has a shape where the angle between the top surface and the side surface is close to 90 degrees at its edges. On the other hand, organic films formed using FMM (Fine Metal Mask) or the like tend to gradually thin out towards the edges, and for example, in the range of 1 μm to 10 μm, the top surface is formed in a sloping shape, making it difficult to distinguish between the top surface and the side surface.

[0163] Between two adjacent light-emitting elements, there is an insulating layer 225, a resin layer 226, and a layer 228.

[0164] Between two adjacent light-emitting elements, the sides of the organic layers 212 are positioned opposite each other, with a resin layer 226 in between. The resin layer 226 is located between the two adjacent light-emitting elements and is provided to fill the edges of each organic layer 212 and the region between the two organic layers 212. The resin layer 226 has a smooth, convex upper surface shape, and a common layer 214 and a common electrode 213 are provided covering the upper surface of the resin layer 226.

[0165] The resin layer 226 functions as a planarizing film that fills the step between two adjacent light-emitting elements. By providing the resin layer 226, it is possible to prevent the common electrode 213 from being separated by the step at the edge of the organic layer 212 (also called step breakage), and to prevent the common electrode on the organic layer 212 from becoming insulated. The resin layer 226 can also be called LFP (Local Filling Planarization).

[0166] As the resin layer 226, an insulating layer having an organic material can be suitably used. For example, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimidoamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins can be used as the resin layer 226. Alternatively, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin may be used as the resin layer 226.

[0167] Furthermore, a photosensitive resin can be used as the resin layer 226. A photoresist may be used as the photosensitive resin. The photosensitive resin can be a positive-type material or a negative-type material.

[0168] The resin layer 226 may contain a material that absorbs visible light. For example, the resin layer 226 itself may be composed of a material that absorbs visible light, or the resin layer 226 may contain a pigment that absorbs visible light. As the resin layer 226, for example, a resin that can be used as a color filter that transmits red, blue, or green light and absorbs other light, or a resin that contains carbon black as a pigment and functions as a black matrix can be used.

[0169] The insulating layer 225 is provided in contact with the side surface of the organic layer 212. The insulating layer 225 also covers the upper end of the organic layer 212. Furthermore, a portion of the insulating layer 225 is provided in contact with the upper surface of the substrate 201.

[0170] The insulating layer 225 is located between the resin layer 226 and the organic layer 212 and functions as a protective film to prevent the resin layer 226 from coming into contact with the organic layer 212. If the organic layer 212 and the resin layer 226 come into contact, the organic layer 212 may dissolve due to organic solvents used during the formation of the resin layer 226. Therefore, as shown in this embodiment, by providing an insulating layer 225 between the organic layer 212 and the resin layer 226, it is possible to protect the sides of the organic layer.

[0171] The insulating layer 225 can be an insulating layer having an inorganic material. For example, inorganic insulating films such as oxide insulating films, nitride insulating films, oxidative nitride insulating films, and nitride oxide insulating films can be used for the insulating layer 225. The insulating layer 225 may be a single layer or a laminated structure. Examples of oxide insulating films include silicon oxide film, aluminum oxide film, magnesium oxide film, indium gallium zinc oxide film, gallium oxide film, germanium oxide film, yttrium oxide film, zirconium oxide film, lanthanum oxide film, neodymium oxide film, hafnium oxide film, and tantalum oxide film. Examples of nitride insulating films include silicon nitride film and aluminum nitride film. Examples of oxidative nitride insulating films include silicon oxidative nitride film and aluminum oxidative nitride film. Examples of nitride oxide insulating films include silicon nitride oxide film and aluminum nitride oxide film. In particular, by applying an oxide metal film such as an aluminum oxide film or hafnium oxide film formed by the ALD method, or an inorganic insulating film such as a silicon oxide film, to the insulating layer 225, an insulating layer 225 with fewer pinholes and excellent function in protecting the EL layer can be formed.

[0172] In this specification, the term "oxide-nitride" refers to a material in which the oxygen content is greater than the nitrogen content, and the term "nitride oxide" refers to a material in which the nitrogen content is greater than the oxygen content. For example, when "silicon oxynitride" is written, it refers to a material in which the oxygen content is greater than the nitrogen content, and when "silicon nitride oxide" is written, it refers to a material in which the nitrogen content is greater than the oxygen content.

[0173] The insulating layer 225 can be formed using sputtering, CVD, PLD, ALD, or other methods. It is preferable to form the insulating layer 225 using the ALD method, which provides good coverage.

[0174] Alternatively, a reflective film (for example, a metal film containing one or more selected from silver, palladium, copper, titanium, and aluminum) may be provided between the insulating layer 225 and the resin layer 226, and the light emitted from the light-emitting layer may be reflected by the reflective film. This can improve the light extraction efficiency.

[0175] Layer 228 is formed when a portion of the protective layer (also called a mask layer or sacrificial layer) used to protect the organic layer 212 remains after etching. The material used for layer 228 can be the same material used for the insulating layer 225. In particular, using the same material for both layer 228 and the insulating layer 225 is preferable because it allows for the use of common processing equipment.

[0176] In particular, metal oxide films such as aluminum oxide films and hafnium oxide films, or inorganic insulating films such as silicon oxide films, formed by the ALD method have few pinholes, and therefore have excellent protective properties for the EL layer, making them suitable for use in insulating layers 225 and 228.

[0177] A protective layer 215 is provided covering the common electrode 213.

[0178] The protective layer 215 can be, for example, a single-layer structure or a multilayer structure including at least an inorganic insulating film. Examples of inorganic insulating films include oxide films or nitride films such as silicon oxide film, silicon oxide nitride film, silicon oxide nitride film, silicon nitride film, aluminum oxide film, aluminum oxide nitride film, and hafnium oxide film. Alternatively, semiconductor materials or conductive materials such as indium gallium oxide, indium zinc oxide, indium tin oxide, and indium gallium zinc oxide may be used as the protective layer 215.

[0179] As the protective layer 215, a laminated film of an inorganic insulating film and an organic insulating film can also be used. For example, it is preferable to have a configuration in which an organic insulating film is sandwiched between a pair of inorganic insulating films. Furthermore, it is preferable that the organic insulating film functions as a planarizing film. This makes the upper surface of the organic insulating film flat, thereby improving the coverage of the inorganic insulating film on top of it and enhancing its barrier properties. In addition, since the upper surface of the protective layer 215 is flat, it is preferable because it reduces the influence of uneven shapes caused by the structure below when a structure (e.g., a color filter, touch sensor electrodes, or lens array, etc.) is provided above the protective layer 215.

[0180] Figure 8(C) shows a connection portion 140 where the connecting electrode 219 and the common electrode 213 are electrically connected. In the connection portion 140, openings are provided in the insulating layer 225 and the resin layer 226 on the connecting electrode 219. The connecting electrode 219 and the common electrode 213 are electrically connected at these openings.

[0181] Figure 8(C) shows a connection portion 140 where the connecting electrode 219 and the common electrode 213 are electrically connected. However, the common electrode 213 may be provided on the connecting electrode 219 via a common layer 214. In particular, when a carrier-injected layer is used for the common layer 214, the electrical resistivity of the material used for the common layer 214 can be sufficiently low and it can be formed to be thin, so there is often no problem even if the common layer 214 is located at the connection portion 140. As a result, the common electrode 213 and the common layer 214 can be formed using the same shielding mask, thereby reducing manufacturing costs.

[0182] The above is a description of an example of a display device configuration.

[0183] [Pixel layout] The following section primarily describes a pixel layout different from that shown in Figure 8(A). There are no particular limitations on the arrangement of light-emitting elements (sub-pixels), and various methods can be applied.

[0184] Furthermore, the top surface shape of the sub-pixel can be, for example, a polygon such as a triangle, quadrilateral (including rectangles and squares), or pentagon, or a polygon with rounded corners, or an ellipse or a circle. Here, the top surface shape of the sub-pixel corresponds to the top surface shape of the light-emitting region of the light-emitting element.

[0185] The pixel 150 shown in Figure 9(A) has an S-stripe array applied to it. The pixel 150 shown in Figure 9(A) is composed of three subpixels: light-emitting elements 210a, 210b, and 210c. For example, light-emitting element 210a may be a blue light-emitting element, light-emitting element 210b may be a red light-emitting element, and light-emitting element 210c may be a green light-emitting element.

[0186] The pixel 150 shown in Figure 9(B) has a light-emitting element 210a with a roughly trapezoidal top surface shape with rounded corners, a light-emitting element 210b with a roughly triangular top surface shape with rounded corners, and a light-emitting element 210c with a roughly square or roughly hexagonal top surface shape with rounded corners. Furthermore, the light-emitting element 210a has a larger light-emitting area than the light-emitting element 210b. Thus, the shape and size of each light-emitting element can be determined independently. For example, the more reliable the light-emitting element, the smaller its size can be. For example, the light-emitting element 210a may be a green light-emitting element, the light-emitting element 210b may be a red light-emitting element, and the light-emitting element 210c may be a blue light-emitting element.

[0187] A Pentile array is applied to pixels 224a and 224b shown in Figure 9(C). Pixels 224a and 224b correspond to pixel 240 shown in the above embodiment. Figure 9(C) shows an example in which pixels 224a having light-emitting elements 210a and 210b, and pixels 224b having light-emitting elements 210b and 210c are arranged alternately. For example, light-emitting element 210a may be a red light-emitting element, light-emitting element 210b may be a green light-emitting element, and light-emitting element 210c may be a blue light-emitting element.

[0188] Pixels 224a and 224b shown in Figures 9(D) and 9(E) employ a delta array. Pixel 224a has two light-emitting elements (elementary elements 210a and 210b) in the top row (1st row) and one light-emitting element (elementary element 210c) in the bottom row (2nd row). Pixel 224b has one light-emitting element (elementary element 210c) in the top row (1st row) and two light-emitting elements (elementary elements 210a and 210b) in the bottom row (2nd row). For example, elementary element 210a may be a red light-emitting element, elementary element 210b may be a green light-emitting element, and elementary element 210c may be a blue light-emitting element.

[0189] Figure 9(D) shows an example where each light-emitting element has a roughly rectangular top surface shape with rounded corners, and Figure 9(E) shows an example where each light-emitting element has a circular top surface shape.

[0190] Figure 9(F) shows an example where light-emitting elements of each color are arranged in a zigzag pattern. Specifically, in a top view, the upper edges of two light-emitting elements arranged in a row (for example, light-emitting elements 210a and 210b, or light-emitting elements 210b and 210c) are offset. For example, light-emitting element 210a may be a red light-emitting element, light-emitting element 210b a green light-emitting element, and light-emitting element 210c a blue light-emitting element.

[0191] In photolithography, the finer the pattern to be processed, the more significant the effects of light diffraction become. This compromises the fidelity of transferring the pattern to the photomask through exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the photomask pattern is rectangular, patterns with rounded corners are likely to form. Consequently, the top surface shape of the light-emitting element may be a polygon with rounded corners, an ellipse, or a circle.

[0192] Furthermore, in a method for manufacturing a display panel according to one embodiment of the present invention, the EL layer is processed into an island shape using a resist mask. The resist film formed on the EL layer needs to be cured at a temperature lower than the heat resistance temperature of the EL layer. Therefore, depending on the heat resistance temperature of the EL layer material and the curing temperature of the resist material, the curing of the resist film may be insufficient. A resist film that is not sufficiently cured may take a shape that deviates from the desired shape during processing. As a result, the top surface shape of the EL layer may become a polygon with rounded corners, an ellipse, or a circle. For example, if an attempt is made to form a resist mask with a square top surface, a resist mask with a circular top surface may be formed, resulting in a circular top surface shape for the EL layer.

[0193] Furthermore, in order to achieve the desired shape of the upper surface of the EL layer, a technique (OPC (Optical Proximity Correction) technique) may be used to pre-correct the mask pattern so that the design pattern and the transferred pattern match. Specifically, in the OPC technique, a correction pattern is added to the corners of the shape on the mask pattern.

[0194] The above is an explanation of pixel layout.

[0195] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0196] (Embodiment 4) This embodiment describes an example configuration of a display device 400 that can be used with the display device 110.

[0197] The display device 400 of this embodiment can be used in electronic devices with relatively large screens, such as television sets, desktop or notebook personal computers, computer monitors, digital signage, and large game machines like pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, smartphones, smartwatches, tablet devices, personal information terminals, and audio playback devices.

[0198] Figure 10 shows a perspective view of the display device 400, and Figure 11(A) shows a cross-sectional view of the display device 400.

[0199] The display device 400 has a configuration in which substrate 452 and substrate 451 are bonded together. In Figure 10, substrate 452 is clearly indicated by a dashed line.

[0200] The display device 400 includes a display unit 462, a circuit 464, wiring 465, etc. Figure 10 shows an example in which IC 473 and FPC 472 are mounted on the display device 400. Therefore, the configuration shown in Figure 10 can also be described as a display module having the display device 400, an IC (integrated circuit), and an FPC.

[0201] For example, a scan line drive circuit can be used as circuit 464.

[0202] Wiring 465 has the function of supplying signals and power to the display unit 462 and the circuit 464. These signals and power are input to wiring 465 from an external source via FPC 472 or from IC 473.

[0203] Figure 10 shows an example in which IC 473 is mounted on the substrate 451 using a COG (Chip On Glass) method or COF (Chip On Film) method. IC 473 can be an IC having, for example, a scan line drive circuit or a signal line drive circuit. Note that the display device 400 and the display module may be configured without an IC. Alternatively, the IC may be mounted on an FPC using a COF method or the like.

[0204] Figure 11(A) shows an example of a cross-section when a portion of the display device 400 is cut, including a part of the area containing the FPC 472, a part of the circuit 464, a part of the display unit 462, and a part of the area containing the connection part. In Figure 11(A), an example of a cross-section is shown when a portion of the display unit 462 is cut, specifically including the area containing the green light-emitting element 430b and the blue light-emitting element 430c.

[0205] The display device 400 shown in Figure 11(A) has transistors 202, 220, light-emitting elements 430b, and 430c between substrates 453 and 454.

[0206] The light-emitting elements 430b and 430c can be the light-emitting elements exemplified in Embodiment 3.

[0207] Here, if the pixels of the display device have three types of subpixels, each having a light-emitting element that emits a different color from the others, examples of these three subpixels include subpixels of three colors: red (R), green (G), and blue (B); and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). If there are four such subpixels, examples of these four subpixels include subpixels of four colors: R, G, B, and white (W); and subpixels of four colors: R, G, B, and Y.

[0208] The substrate 454 and the protective layer 416 are bonded together via an adhesive layer 442. The adhesive layer 442 is provided in overlap with the light-emitting elements 430b and 430c, respectively, and a solid encapsulation structure is applied to the display device 400.

[0209] The light-emitting element 430b and 430c have conductive layers 411a, 411b, and 411c as pixel electrodes. Conductive layer 411b is reflective to visible light and functions as a reflective electrode. Conductive layer 411c is transparent to visible light and functions as an optical adjustment layer.

[0210] The conductive layer 411a is connected to the conductive layer 232b of the transistor 220 through an opening provided in the insulating layer 223. The transistor 220 has the function of controlling the driving of the light-emitting element.

[0211] An EL layer 412G or EL layer 412B is provided covering the pixel electrodes. An insulating layer 421 is provided in contact with the side surfaces of the EL layer 412G and the EL layer 412B, and a resin layer 422 is provided to fill the recesses of the insulating layer 421. A layer 424 is provided between the EL layer 412G and the insulating layer 421, and between the EL layer 412B and the insulating layer 421, respectively. A common layer 414, a common electrode 413, and a protective layer 416 are provided covering the EL layer 412G and the EL layer 412B.

[0212] The light emitted by the light-emitting element is directed towards the substrate 452. It is preferable to use a material with high transmittance to visible light for the substrate 452.

[0213] Both transistors 202 and 220 are formed on the substrate 453. These transistors can be manufactured using the same materials and the same process.

[0214] The substrate 453 and the insulating layer 222 are bonded together by an adhesive layer 455.

[0215] The method for manufacturing the display device 400 involves first bonding a fabricated substrate, on which an insulating layer 222, transistors, light-emitting elements, etc., are provided, to a substrate 454 using an adhesive layer 442. Then, the fabricated substrate is peeled off and the substrate 453 is attached to the exposed surface, thereby transferring the components formed on the fabricated substrate to the substrate 453. It is preferable that both the substrate 453 and the substrate 454 are flexible. This increases the flexibility of the display device 400.

[0216] The insulating layer 222 can be an inorganic insulating film that can be used for the insulating layers 221 and 225.

[0217] A connection portion 204 is provided in the region of substrate 453 that does not overlap with substrate 454. At the connection portion 204, wiring 465 is electrically connected to FPC 472 via conductive layer 466 and connection layer 242. The conductive layer 466 can be obtained by processing the same conductive film as the pixel electrode. This allows the connection portion 204 and FPC 472 to be electrically connected via the connection layer 242.

[0218] Transistors 202 and 220 have a conductive layer 231 that functions as a gate, an insulating layer 221 that functions as a gate insulating layer, a semiconductor layer 241 having a channel forming region 241i and a pair of low-resistance regions 241n, a conductive layer 232a connected to one of the pair of low-resistance regions 241n, a conductive layer 232b connected to the other of the pair of low-resistance regions 241n, an insulating layer 235 that functions as a gate insulating layer, a conductive layer 233 that functions as a gate, and an insulating layer 225 covering the conductive layer 233. The insulating layer 221 is located between the conductive layer 231 and the channel forming region 241i. The insulating layer 235 is located between the conductive layer 233 and the channel forming region 241i.

[0219] Figure 11(A) shows an example in which the insulating layer 235 covers the top and sides of the semiconductor layer. The conductive layers 232a and 232b are connected to the low-resistance region 241n through openings provided in the insulating layers 235 and 225, respectively. Of the conductive layers 232a and 232b, one functions as a source and the other as a drain.

[0220] On the other hand, in the transistor 209 shown in Figure 11(B), the insulating layer 235 overlaps with the channel formation region 241i of the semiconductor layer 241, but does not overlap with the low-resistance region 241n. For example, the structure shown in Figure 11(B) can be fabricated by processing the insulating layer 235 using the conductive layer 233 as a mask. In Figure 11(B), an insulating layer 225 is provided covering the insulating layer 235 and the conductive layer 233, and the conductive layer 232a and conductive layer 232b are connected to the low-resistance region 241n, respectively, through openings in the insulating layer 225. Furthermore, an insulating layer 229 covering the transistor may also be provided.

[0221] The transistor structure of the display device of this embodiment is not particularly limited. For example, planar transistors, staggered transistors, inverse staggered transistors, etc., can be used. Furthermore, either a top-gate or bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0222] Transistors 202 and 220 are configured in which a semiconductor layer on which a channel is formed is sandwiched between two gates. The transistors may be driven by connecting the two gates and supplying them with the same signal. Alternatively, the threshold voltage of the transistors may be controlled by applying a potential to control the threshold voltage to one of the two gates and a potential to drive the other gate.

[0223] The crystallinity of the semiconductor material used in the semiconductor layer of the transistor is not particularly limited; amorphous semiconductors, single-crystal semiconductors, or semiconductors with crystalline properties other than single crystals (microcrystalline semiconductors, polycrystalline semiconductors, or semiconductors having crystalline regions in part) may be used. Using a single-crystal semiconductor or a semiconductor with crystalline properties is preferable because it can suppress the degradation of transistor characteristics.

[0224] The semiconductor layer of the transistor preferably has a metal oxide (also called an oxide semiconductor). In other words, the display device of this embodiment preferably uses a transistor (hereinafter referred to as an OS transistor) that uses a metal oxide in the channel formation region.

[0225] The band gap of the metal oxide used in the semiconductor layer of the transistor is preferably 2 eV or more, and more preferably 2.5 eV or more. By using a metal oxide with a large band gap, the off-current of the OS transistor can be reduced.

[0226] The metal oxide preferably contains at least indium or zinc, and more preferably indium and zinc. For example, the metal oxide preferably contains indium, M (where M is one or more selected from gallium, aluminum, yttrium, tin, silicon, boron, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, and cobalt), and zinc.

[0227] Alternatively, the semiconductor layer of the transistor may contain silicon. Examples of silicon include amorphous silicon and crystalline silicon (such as low-temperature polysilicon and single-crystal silicon).

[0228] The transistors in circuit 464 and the transistors in display unit 462 may have the same structure or different structures. The structures of the multiple transistors in circuit 464 may all be the same or there may be two or more different structures. Similarly, the structures of the multiple transistors in display unit 462 may all be the same or there may be two or more different structures.

[0229] It is preferable to use a material that does not easily allow impurities such as water and hydrogen to diffuse into at least one layer of the insulating layer covering the transistor. This allows the insulating layer to function as a barrier layer. With such a configuration, the diffusion of impurities from the outside into the transistor can be effectively suppressed, thereby improving the reliability of the display device.

[0230] It is preferable to use an inorganic insulating film for insulating layer 221, insulating layer 222, insulating layer 225, insulating layer 229, and insulating layer 235. Examples of inorganic insulating films that can be used include silicon nitride film, silicon oxynitride film, silicon oxide film, silicon nitride film, aluminum oxide film, and aluminum nitride film. Alternatively, hafnium oxide film, yttrium oxide film, zirconium oxide film, gallium oxide film, tantalum oxide film, magnesium oxide film, lanthanum oxide film, cerium oxide film, and neodymium oxide film may also be used. Furthermore, two or more of the above-mentioned inorganic insulating films may be laminated together.

[0231] An organic insulating film is preferred for the insulating layer 223, which functions as a planarizing layer. Examples of materials that can be used as the organic insulating film include acrylic resins, polyimide resins, epoxy resins, polyamide resins, polyimidoamide resins, siloxane resins, benzocyclobutene resins, phenolic resins, and precursors of these resins.

[0232] Various optical components can be arranged along the inner or outer surface of the substrate 454. Examples of optical components include light-shielding layers, polarizing plates, phase difference plates, light-diffusing layers (such as diffusion films), anti-reflective layers, microlens arrays, and light-gathering films. Furthermore, an antistatic film to suppress the adhesion of dust, a water-repellent film to make it difficult for dirt to adhere, a hard coat film to suppress the occurrence of scratches during use, and an impact-absorbing layer may be arranged on the outer surface of the substrate 454.

[0233] By providing a protective layer 416 that covers the light-emitting element, it is possible to suppress the ingress of impurities such as water into the light-emitting element and improve the reliability of the light-emitting element.

[0234] Figure 11(A) shows the connection section 238. At the connection section 238, the common electrode 413 and the wiring are electrically connected. Figure 11(A) shows an example where the same stacked structure as the pixel electrode is applied to the wiring.

[0235] Substrates 453 and 454 can be made of glass, quartz, ceramics, sapphire, resin, metal, alloy, semiconductor, etc., respectively. The substrate on the side that extracts light from the light-emitting element should be made of a material that transmits the light. Using flexible materials for substrates 453 and 454 can increase the flexibility of the display device. Alternatively, a polarizing plate may be used as substrate 453 or substrate 454.

[0236] Substrates 453 and 454 can be made from polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamide-imide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. One or both of substrates 453 and 454 may be made of glass of a thickness sufficient to provide flexibility.

[0237] Various types of curing adhesives can be used as the adhesive layer, including UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, and anaerobic adhesives. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, and EVA (ethylene vinyl acetate) resins. Materials with low moisture permeability, such as epoxy resins, are particularly preferred. Two-component mixed resins may also be used. Adhesive sheets may also be used.

[0238] As the connecting layer 242, an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), etc., can be used.

[0239] Materials that can be used for conductive layers such as the gate, source, and drain of transistors, as well as various wirings and electrodes that constitute display devices, include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, as well as alloys mainly composed of these metals. Films containing these materials can be used as single layers or in a multilayer structure.

[0240] Furthermore, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene can be used as the light-transmitting conductive material. Alternatively, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing such metallic materials, can be used. Alternatively, nitrides of such metallic materials (e.g., titanium nitride) may be used. When using metallic materials or alloy materials (or their nitrides), it is preferable to make them thin enough to be light-transmitting. In addition, a laminated film of the above materials can be used as a conductive layer. For example, using a laminated film of a silver-magnesium alloy and indium tin oxide is preferable because it can enhance conductivity. These can also be used for conductive layers of various wirings and electrodes that constitute a display device, and for conductive layers of light-emitting elements (conductive layers that function as pixel electrodes or common electrodes).

[0241] Examples of insulating materials that can be used for each insulating layer include resins such as acrylic resin and epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxide nitride, silicon nitride, and aluminum oxide.

[0242] An example of a circuit configuration that can be used for a sub-pixel 230 is shown in Figures 12(A) and (B). The sub-pixel 230 shown in Figure 12(A) has a pixel circuit 434 and a light-emitting element EL.

[0243] Various display elements can be used as the light-emitting element (EL), such as EL elements (EL elements containing organic and inorganic materials, organic EL elements, inorganic EL elements), LEDs (white LEDs, red LEDs, green LEDs, blue LEDs, etc.), micro LEDs, QLEDs (Quantum-dot Light Emitting Diodes), and electron emission elements. For example, the light-emitting element 210 shown in the above embodiment can be used as the light-emitting element (EL).

[0244] The pixel circuit 434 has transistors M1, M2, M3, M4, and capacitor C1. Furthermore, the sub-pixel 230 shown in Figure 12(A) is electrically connected to wirings GL1, GL2, GL3, SL, AL, and CL.

[0245] Gate signals are supplied to wirings GL1, GL2, and GL3. A source signal is supplied to wiring SL. Constant potentials are supplied to wirings AL and CL, respectively. The anode side of the light-emitting element EL can be made to a high potential, and the cathode side to a lower potential than the anode side.

[0246] Transistor M1 has its gate electrically connected to wiring GL1, one of its source and drain electrically connected to wiring SL, and the other of its source and drain electrically connected to one electrode of capacitor C1 and the gate of transistor M2.

[0247] The region where the source and drain of transistor M1, the gate of transistor M2, and one electrode of capacitor C1 are electrically connected is called node ND. Transistor M1 functions as a switch to control the selection and deselection of pixels that write the video signal to node ND. Therefore, transistor M1 can also be called a selection transistor.

[0248] Capacitor C1 functions as a retaining capacitor. The other electrode of capacitor C1 is electrically connected to the anode of the light-emitting element EL. Note that capacitor C1 may be omitted if it is not needed.

[0249] One of the sources or drains of transistor M2 is electrically connected to wiring AL. The other of the sources or drains of transistor M2 is electrically connected to the anode of light-emitting element EL. Additionally, wiring CL is electrically connected to the cathode of light-emitting element EL.

[0250] Transistor M2 has the function of controlling the amount of current flowing to the light-emitting element EL in accordance with the potential of node ND. Therefore, transistor M2 can also be called a driving transistor.

[0251] The gate of transistor M3 is electrically connected to wiring GL2, and either its source or drain is electrically connected to the anode of light-emitting element EL. The other end of the source or drain of transistor M3 is electrically connected to wiring V0.

[0252] The gate of transistor M4 is electrically connected to wiring GL3, and either its source or drain is electrically connected to the gate of transistor M2. The other source or drain of transistor M4 is electrically connected to wiring V0.

[0253] By making transistors M3 and M4 conduct during the same period, the source and gate of transistor M2 become at the same potential, making transistor M2 non-conducting. This allows the current flowing to the light-emitting element EL to be forcibly interrupted. Such a pixel circuit is suitable when using a display method that alternates between display periods and off periods. For example, 0V is supplied to the wiring V0.

[0254] In Figure 12(A), transistors M1, M2, M3, and M4 are transistors with back gates. The gates and back gates of transistors M1, M3, and M4 are electrically connected. In addition, the back gate of transistor M2 is electrically connected to the anode of the light-emitting element EL.

[0255] Figure 12(B) shows a modified version of the circuit configuration shown in Figure 12(A). In Figure 12(B), n transistors m (where n is an integer greater than or equal to 2) are connected in series as transistor M2. n The gates of each transistor m are electrically connected to node ND. In addition, the back gates of each of the n transistors m are electrically connected to the anode of the light-emitting element EL. Therefore, the n transistors m function as essentially one transistor. The transistor M2 shown in Figure 12(B) is a multi-gate type transistor with n gates.

[0256] In normal image display, transistor M2 operates in the saturation region. Generally, when operating a transistor in the saturation region with a constant gate voltage, it is preferable that the change in drain current (Id) is small in relation to the change in drain voltage (Vd). A small change in Id in relation to a change in Vd is said to indicate good saturation characteristics.

[0257] In multi-gate transistors, a larger number of gates (n) results in better saturation characteristics. Specifically, increasing the number of transistors in series used as transistor M2 yields better saturation characteristics. The number of gates and the number of transistors in series (n) is preferably 2 or greater, and more preferably 5 or greater.

[0258] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0259] (Embodiment 5) This embodiment describes a light-emitting element (also called a light-emitting device) that can be used in the display device 110.

[0260] In this specification, devices fabricated using a metal mask or an FMM (Fine Metal Mask, a high-resolution metal mask) may be referred to as MM (Metal Mask) structured devices. Furthermore, in this specification, devices fabricated without using a metal mask or an FMM may be referred to as MML (Metal Maskless) structured devices.

[0261] In this specification, a structure in which different light-emitting layers are created or painted for each color of light-emitting device (here, blue (B), green (G), and red (R)) may be referred to as an SBS (Side By Side) structure. Also, in this specification, a light-emitting device capable of emitting white light may be referred to as a white light-emitting device. A white light-emitting device can be combined with a colored layer (for example, a color filter) to realize a full-color display device.

[0262] Light-emitting devices can be broadly classified into single-structure and tandem-structure devices. A single-structure device has one light-emitting unit between a pair of electrodes. This light-emitting unit has a configuration that includes one or more light-emitting layers. When obtaining white light emission using two light-emitting layers, the light-emitting layers should be selected such that the light emitted from each of the two layers is complementary in color. For example, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary, a configuration that emits white light as a whole can be obtained. Also, when obtaining white light emission using three or more light-emitting layers, the light-emitting device should be configured so that the light-emitting colors of the three or more layers combine to emit white light as a whole.

[0263] A tandem device has multiple light-emitting units between a pair of electrodes. Each light-emitting unit includes one or more light-emitting layers. By using light-emitting layers that emit light of the same color in each light-emitting unit, the brightness per given current can be increased, and a more reliable light-emitting device can be achieved compared to a single structure. To obtain white light emission in a tandem structure, the light from the light-emitting layers of multiple light-emitting units should be combined to produce white light emission. The combination of light-emitting colors that produces white light emission is the same as in a single structure. In a tandem device, it is preferable to provide an intermediate layer, such as a charge-generating layer, between the multiple light-emitting units.

[0264] When comparing white light-emitting devices with SBS structure light-emitting devices, SBS structure light-emitting devices can consume less power than white light-emitting devices. On the other hand, white light-emitting devices have a simpler manufacturing process than SBS structure light-emitting devices, resulting in lower manufacturing costs and higher manufacturing yields.

[0265] <Example of light-emitting device configuration> As shown in Figure 13(A), the light-emitting device has an EL layer 790 between a pair of electrodes (lower electrode 791, upper electrode 792). The EL layer 790 can be composed of multiple layers, such as layer 720, light-emitting layer 711, and layer 730. Layer 720 may include, for example, a layer containing a material with high electron injection properties (electron injection layer) and a layer containing a material with high electron transport properties (electron transport layer). The light-emitting layer 711 may include, for example, a light-emitting compound. Layer 730 may include, for example, a layer containing a material with high hole injection properties (hole injection layer) and a layer containing a material with high hole transport properties (hole transport layer).

[0266] A configuration having a layer 720, an emissive layer 711, and a layer 730 provided between a pair of electrodes can function as a single emissive unit, and in this specification, the configuration shown in Figure 13(A) is referred to as a single structure.

[0267] Specifically, the light-emitting device shown in Fig. 13(B) has a layer 730-1, a layer 730-2, a light-emitting layer 711, a layer 720-1, a layer 720-2, and an upper electrode 792 on a lower electrode 791. For example, the lower electrode 791 is used as an anode, and the upper electrode 792 is used as a cathode. At this time, the layer 730-1 functions as a hole injection layer, the layer 730-2 functions as a hole transport layer, the layer 720-1 functions as an electron transport layer, and the layer 720-2 functions as an electron injection layer. On the other hand, when the lower electrode 791 is used as a cathode and the upper electrode 792 is used as an anode, the layer 730-1 functions as an electron injection layer, the layer 730-2 functions as an electron transport layer, the layer 720-1 functions as a hole transport layer, and the layer 720-2 functions as a hole injection layer. By adopting such a layer structure, carriers can be efficiently injected into the light-emitting layer 711, and the efficiency of carrier recombination in the light-emitting layer 711 can be increased.

[0268] In addition, as shown in Fig. 13(C) and Fig. 13(D), a configuration in which a plurality of light-emitting layers (light-emitting layer 711, light-emitting layer 712, and light-emitting layer 713) are provided between the layer 720 and the layer 730 is also a variation of the single structure.

[0269] As shown in Fig. 13(E) and Fig. 13(F), a configuration in which a plurality of light-emitting units (EL layer 790a, EL layer 790b) are connected in series via an intermediate layer (charge generation layer) 740 is referred to as a tandem structure in this specification. The tandem structure may also be called a stack structure. By adopting the tandem structure, a light-emitting device capable of high-brightness light emission can be obtained.

[0270] In Fig. 13(C), the same light-emitting material that emits light of the same color, and even the same light-emitting material, may be used for the light-emitting layer 711, the light-emitting layer 712, and the light-emitting layer 713. By laminating the light-emitting layers, the light-emitting luminance can be increased.

[0271] Furthermore, different light-emitting materials may be used for the light-emitting layers 711, 712, and 713. When the light emitted by the light-emitting layers 711, 712, and 713 are complementary in color, white light emission is obtained. Figure 13(D) shows an example in which a colored layer 795, which functions as a color filter, is provided. By passing white light through the color filter, light of a desired color can be obtained.

[0272] Furthermore, in Figure 13(E), the light-emitting layer 711 and the light-emitting layer 712 may be made of light-emitting materials that emit light of the same color. Alternatively, the light-emitting layer 711 and the light-emitting layer 712 may be made of light-emitting materials that emit different colors. When the light emitted by the light-emitting layer 711 and the light emitted by the light-emitting layer 712 are complementary colors, white light emission is obtained. Figure 13(F) shows an example in which a colored layer 795 is further provided.

[0273] Furthermore, in Figures 13(C), 13(D), 13(E), and 13(F), as shown in Figure 13(B), layer 720 and layer 730 may be a laminated structure consisting of two or more layers.

[0274] Furthermore, in Figure 13(D), the light-emitting layers 711, 712, and 713 may be made of light-emitting materials that emit light of the same color. Similarly, in Figure 13(F), the light-emitting layers 711 and 712 may be made of light-emitting materials that emit light of the same color. In this case, by applying a color conversion layer instead of the colored layer 795, it is possible to obtain light of a desired color different from that of the light-emitting material. For example, by using a blue light-emitting material in each light-emitting layer, blue light can pass through the color conversion layer to obtain light with a longer wavelength than blue (e.g., red, green, etc.). Fluorescent materials, phosphorescent materials, or quantum dots can be used as the color conversion layer.

[0275] The light-emitting color of the light-emitting device can be red, green, blue, cyan, magenta, yellow, or white, depending on the material that makes up the EL layer 790. Furthermore, the color purity can be further enhanced by adding a microcavity structure to the light-emitting device.

[0276] A light-emitting device that emits white light may have a configuration in which two or more light-emitting materials are included in the light-emitting layer, or two or more light-emitting layers having different light-emitting materials may be stacked. In this case, the light-emitting materials should be selected such that the light emitted by each of them is in a complementary color relationship.

[0277] Here, we will describe a more specific example of the configuration of a light-emitting device.

[0278] The light-emitting device has at least a light-emitting layer. The light-emitting device may also have layers other than the light-emitting layer that include a material with high hole injection properties, a material with high hole transport properties, a hole-blocking material, a material with high electron transport properties, a material with high electron injection properties, an electron-blocking material, or a bipolar material (a material with high electron transport and hole transport properties).

[0279] The light-emitting device may use either low-molecular-weight compounds or high-molecular-weight compounds, and may also contain inorganic compounds. The layers constituting the light-emitting device can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating.

[0280] For example, a light-emitting device can have a configuration that includes one or more layers from among a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0281] The hole injection layer is a layer that injects holes from the anode into the hole transport layer, and is a layer containing a material with high hole injection capabilities. Examples of materials with high hole injection capabilities include aromatic amine compounds and composite materials containing hole transport materials and acceptor materials (electron-accepting materials).

[0282] The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light-emitting layer. The hole transport layer is a layer containing a hole-transporting material. The hole-transporting material is 1 × 10⁻¹⁶ -6 cm 2Materials having a hole mobility of / Vs or higher are preferred. However, other materials can also be used as long as they have higher hole transport capabilities than electron transport. Preferred hole transport materials include π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.) and aromatic amines (compounds having an aromatic amine skeleton), which are materials with high hole transport capabilities.

[0283] The electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light-emitting layer. The electron transport layer is a layer containing an electron-transporting material. The electron-transporting material is 1 × 10⁻¹⁶ -6 cm 2 Materials having an electron mobility of / Vs or higher are preferred. However, other materials can also be used as long as they have higher electron transport capabilities than holes. Examples of electron-transporting materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron-deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds.

[0284] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer, and is a layer containing a material with high electron injection capabilities. Alkali metals, alkaline earth metals, or compounds thereof can be used as materials with high electron injection capabilities. Composite materials containing both electron transport materials and donor materials (electron-donating materials) can also be used as materials with high electron injection capabilities.

[0285] Examples of electron injection layers include lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-(quinolinolato)lithium (abbreviated as Liq), 2-(2-pyridyl)phenolate (abbreviated as LiPP), 2-(2-pyridyl)-3-pyridinolatritium (abbreviated as LiPPy), 4-phenyl-2-(2-pyridyl)phenolate (abbreviated as LiPPP), and lithium oxide (LiO2). x Alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. Furthermore, the electron injection layer may be a multilayer structure of two or more layers. For example, this multilayer structure may consist of lithium fluoride as the first layer and ytterbium as the second layer.

[0286] Alternatively, an electron-transporting material may be used as the electron injection layer described above. For example, a compound having a lone pair of electrons and an electron-deficient heteroaromatic ring can be used as the electron-transporting material. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), or a triazine ring can be used.

[0287] Furthermore, it is preferable that the lowest unoccupied molecular orbital (LUMO) level of organic compounds containing lone pairs of electrons is between -3.6 eV and -2.3 eV. In addition, the highest occupied molecular orbital (HOMO) level and LUMO level of organic compounds can generally be estimated by methods such as cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy.

[0288] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), diquinoxalino[2,3-a:2’,3’-c]phenazine (abbreviation: HATNA), 2,4,6-tris[3’-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), etc. can be used for organic compounds having lone pairs of electrons. Note that NBPhen has a higher glass transition temperature (Tg) and excellent heat resistance compared to BPhen.

[0289] The light-emitting layer is a layer containing a light-emitting substance. The light-emitting layer can have one or more light-emitting substances. As the light-emitting substance, substances exhibiting light-emitting colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, red, etc. can be appropriately used. Also, a substance that emits near-infrared light can be used as the light-emitting substance.

[0290] Examples of the light-emitting substance include a fluorescent material, a phosphorescent material, a TADF material, a quantum dot material, etc.

[0291] Examples of the fluorescent material include, for example, pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, naphthalene derivatives, etc.

[0292] Examples of the phosphorescent material include, for example, an organometallic complex having a 4H-triazole skeleton, a 1H-triazole skeleton, an imidazole skeleton, a pyrimidine skeleton, a pyrazine skeleton, or a pyridine skeleton (especially an iridium complex), an organometallic complex having a phenylpyridine derivative having an electron-withdrawing group as a ligand (especially an iridium complex), a platinum complex, a rare earth metal complex, etc.

[0293] The light-emitting layer may contain one or more types of organic compounds (host material, assist material, etc.) in addition to the light-emitting substance (guest material). One or more of these organic compounds may be hole-transporting materials and / or electron-transporting materials. Alternatively, one or more of these organic compounds may be bipolar materials or TADF materials.

[0294] The light-emitting layer preferably comprises, for example, a phosphorescent material and a combination of a hole-transporting material and an electron-transporting material that readily forms an excitation complex. This configuration allows for efficient emission using ExTET (Exciplex-Triplet Energy Transfer), which is energy transfer from the excitation complex to the light-emitting substance (phosphorescent material). By selecting a combination that forms an excitation complex that exhibits emission overlapping with the wavelength of the lowest-energy absorption band of the light-emitting substance, energy transfer becomes smoother, and light emission can be obtained efficiently. This configuration simultaneously achieves high efficiency, low-voltage operation, and a long lifespan for the light-emitting device.

[0295] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part. [Examples]

[0296] In this embodiment, we will describe the results of correcting the brightness variation of the sub-pixels 230R of the display unit 111 using the image correction system and image correction method shown in the above embodiment. Specifically, we will describe the image correction results when the correction video signal AS is 8 bits and the gradation value of the correction video signal AS is 192.

[0297] First, a correction video signal AS with a gradation value of 192 was supplied to all sub-pixels 230R of the display unit 111, causing all sub-pixels 230R to emit light. Next, the display unit 111 was imaged by the imaging device 121, and imaging data including the luminance distribution was acquired (see step S501). Figure 14(A) shows an image of the luminance distribution, which visualizes a portion of the imaging data.

[0298] Next, the positions and areas S of all subpixels 230R on the imaging data were set (see step S502). To facilitate setting the positions and areas S of the subpixels 230R on the imaging data, adjustments were made beforehand to reduce the slope and distortion of the brightness distribution on the imaging data. Since the area S only needs to be the same for all subpixels 230R, an arbitrary size was used. Figure 14(B) shows rectangles overlaid on the image shown in Figure 14(A), indicating the positions and areas S of the subpixels 230R set.

[0299] Next, the integral value of the luminance within area S was calculated for all sub-pixels 230R in the imaging data. That is, this integral value is the luminosity per sub-pixel 230R. Here, the luminosity of the sub-pixel 230R with the highest luminosity (sub-pixel 230Rmax) was used as the correction standard (see steps S503 and S504).

[0300] Next, correction data CVR was generated for each sub-pixel 230R so that the luminosity of all sub-pixels 230R in the imaging data was equal to the correction standard (see step S505).

[0301] Figure 15(A) shows a portion of the image (Before) of the correction video signal AS before correction with the correction data CVR. Figure 15(B) shows a portion of the image (After) of the image taken after correcting the correction video signal AS using the correction data CVR. It can be seen that the brightness variation of the entire display unit 111 is reduced by correcting the correction video signal AS for each sub-pixel 230R.

[0302] Figure 16 is a histogram showing the luminance variation before and after correction using the correction data CVR. The number of pixels evaluated in Figure 16 is 180 × 240. The horizontal axis of Figure 16 shows the luminance of each pixel normalized by the area S and converted to luminance, divided into classes for each fixed interval. The vertical axis of Figure 16 is the probability density, showing the proportion of pixels included in one interval to all pixels. Figure 16 also shows the correction criterion and the coefficient of variation before and after correction.

[0303] Figure 16 shows that the intervals with high probability density in the corrected histogram closely coincide with the correction criteria. Furthermore, the coefficient of variation after correction is smaller than before correction, indicating that the luminance variation is reduced by using the image correction method according to one aspect of the present invention. [Explanation of Symbols]

[0304] 100 Image Correction Systems 110 Display device 111 Display section 112 Gate Driver Circuit 113 Source Driver Circuit 114 Control device 115 Arithmetic equipment 116 Storage device 117 Input / Output Devices 119 Bus Line 120 Correction data generation device 121 Imaging device 124 Control device 125 Arithmetic equipment 126 Storage device 127 Input / Output Devices 129 Bus Line 131 Peak 140 Connection part 150 pixels

Claims

1. An image correction system including an imaging device, a first arithmetic unit, a display unit having a plurality of pixels, and a second arithmetic unit, The imaging device is a function of capturing an image of a first gradation displayed on the display unit and acquiring a luminance distribution; The first computing device Using the luminance distribution, a function of calculating a luminous intensity of each of the plurality of pixels, a function of calculating a correction standard, and a function of calculating correction data for each of the plurality of pixels using the luminous intensity of each of the plurality of pixels and the correction standard; The second calculation device uses the correction data to An image correction system having a function of correcting a video signal for displaying an image on the display unit.

2. In claim 1, The correction criteria are: An image correction system that is the maximum, average, or median luminous intensity of each of the plurality of pixels.

3. In claim 1 or claim 2, a first storage device and a second storage device; the first storage device has a function of storing the luminance distribution, The second storage device has a function of storing the correction data.

Images