Mura compensation device and virtual reality device including same

Abstract

According to one embodiment of the present invention, a virtual reality device having a display panel comprises: memory for receiving compensation data for compensating for luminance deviation or mura characteristics generated in the display panel from a mura imaging device and storing same; an AP for outputting a first image, which is an original image scaled according to the resolution of the display panel, or a second image obtained by compressing the original image; and a driver IC having a built-in mura compensation device that analyzes the first image, the second image, and the compensation data output from the AP and compensates the second image on the basis of the analyzed result, wherein the mura compensation device, when FRD of the virtual reality device is turned on, analyzes the compensation data and a third image, which is an image obtained by restoring a peripheral area of the second image to the resolution of the first image, and calculates an offset compensation value, capable of adjusting the luminance deviation or mura characteristics detected from the third image, on the basis of the analysis result.

Description

Mura compensation device and virtual reality device including the same

[0001] The present invention relates to a mura compensation device and a virtual reality device including the same.

[0002] Recently, LCD panels and OLED panels are widely used as display panels.

[0003] Conventional display panels feature a multitude of pixels, and images are formed on the display panel based on the brightness of each pixel. The brightness of each pixel is controlled by a grayscale value, and the display panel's driver generates a data voltage that is supplied to each pixel based on the grayscale value.

[0004] One of the key factors determining image quality in these display panel operating methods is luminance uniformity. If luminance is uneven, the display panel's image quality is perceived as poor. When applying identical grayscale values ​​to multiple pixels on a display panel, luminance variations between pixels degrade image quality.

[0005] However, most display panels inherently exhibit luminance variations due to manufacturing or pixel layout issues. This luminance variation is sometimes referred to as "mura." If a display panel's pixels are driven with identical grayscale values ​​without compensation applied, a single-color image is not displayed, but rather an image with a blotchy pattern. This blotchy pattern is caused by luminance variations across individual pixels.

[0006] To eliminate this luminance deviation, many mura compensation devices are being developed.

[0007] Furthermore, VR (Virtual Reality) devices, one of the virtual reality devices currently under development, are portable devices but utilize higher-resolution displays than TVs, monitors, and mobile phones. Transmitting such a large amount of data consumes significant power. One way to achieve low power consumption in VR devices is to transmit the user's focused area (ROI, region of interest) in high resolution, while scaling down the image for the remaining areas (peripheral areas) and transmitting it in lower resolution.

[0008] The purpose of the present invention is to provide a mura compensation device capable of accurately calculating and removing luminance deviation or mura characteristics in a reduced image even when the original image is reduced, and a virtual reality device including the same.

[0009] According to one embodiment of the present invention, a virtual reality device having a display panel includes a memory that receives and stores compensation data for compensating for luminance deviation or mura characteristics occurring in the display panel from a mura imaging device; an application processor (AP) that outputs a first image, which is an original image scaled to match the resolution of the display panel, or a second image, which is a compressed version of the original image; and a driver IC (D-IC) having a mura compensation device built in, which analyzes the first image, the second image, and the compensation data stored in the memory output from the AP, and compensates for the second image based on the analyzed result; wherein, when an FRD of the virtual reality device is turned on, the mura compensation device analyzes a third image, which is an image obtained by restoring a peripheral area of ​​the second image to the resolution of the first image, and the compensation data, and calculates an offset compensation value capable of adjusting luminance deviation or mura characteristics detected in the third image based on the analyzed result.

[0010] In addition, the first image may include a first GGS region having an original resolution of the first image and a second GGS region having a lower resolution than the original resolution of the first image and disposed around the first GGS region, and the driver IC (D-IC) may control a gate driver that supplies a pulse of a gate signal to a gate line disposed on the display panel, so that when the FRD is turned on, the pulse of the gate signal is supplied to the second GGS region simultaneously for every two gate lines, and the pulse of the gate signal is supplied to the first GGS region for every gate line.

[0011] In addition, the Mura compensation device may include, when compensated data is provided in units of pixels or blocks of pixels of the third image based on the compensation data, comparing and analyzing the data with preset reference data, calculating the offset compensation value based on the data, and applying the calculated offset compensation value to the compensation data to calculate final compensation data.

[0012] In addition, the Mura compensation device may include receiving a temperature value measured outside or inside the virtual reality device from the AP, comparing the temperature value with a preset reference temperature range, and calculating a temperature gain that can compensate for a brightness deviation or the intensity of a Mura characteristic due to the temperature if the temperature value is outside the preset reference temperature range as a result of the comparison.

[0013] Additionally, the Mura compensation device may include applying the calculated temperature gain to the final compensation data to compensate for luminance deviation or Mura characteristics.

[0014] A mura compensation device and a virtual reality device including the same according to an embodiment of the present invention have the effect of improving the image quality by accurately calculating and removing the luminance deviation or mura characteristic in a reduced image even if the original image is reduced.

[0015] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0016] FIG. 1 is a block diagram showing a free compensation system according to one embodiment of the present invention.

[0017] FIG. 2 is a diagram for explaining an AP and D-IC according to an embodiment of the present invention.

[0018] FIG. 3 is a diagram showing a focus area, a peripheral area, a first GGS area, and a second GGS area according to an embodiment of the present invention.

[0019] FIG. 4 and FIG. 5 are diagrams showing a first GGS region and a second GGS region expressed as a plurality of lines according to an embodiment of the present invention.

[0020] FIG. 6 is a diagram for explaining in detail a Mura compensation device according to an embodiment of the present invention.

[0021] FIGS. 7 to 9 are diagrams for explaining the operation of a Mura compensation device according to an embodiment of the present invention.

[0022] FIG. 10 is a diagram for explaining a temperature gain according to an embodiment of the present invention.

[0023] FIG. 11 is a diagram for explaining in detail a Mura compensation device according to another embodiment of the present invention.

[0024] Fig. 12 is a diagram for explaining a coordinate adjustment unit according to another embodiment of the present invention.

[0025] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. The present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. The embodiments are provided solely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined solely by the scope of the claims.

[0026] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are illustrative, and the present invention is not limited to the details depicted in the drawings. Throughout the specification, the same reference numerals designate substantially the same components. Furthermore, in describing the present invention, detailed descriptions of related known technologies will be omitted if they are deemed to unnecessarily obscure the gist of the present invention.

[0027] In the specification, when “comprises,” “includes,” “has,” and “consists of,” other parts may be added unless “only” is used. When a component is expressed in the singular, it may be interpreted as plural unless otherwise explicitly stated.

[0028] When interpreting a component, it is interpreted as including the error range even if there is no separate explicit description.

[0029] When the positional relationship and interconnectedness between two components are described as ‘on’, ‘above’, ‘below’, ‘next to’, ‘connect, couple’, crossing, intersecting, etc., one or more other components may be interposed between the components unless there is a mention of ‘directly’ or ‘directly’.

[0030] When the temporal relationship is explained with phrases such as ‘after’, ‘following’, ‘next to’, or ‘before’, it may not be continuous on the time axis unless ‘right away’ or ‘directly’ is used.

[0031] Although first, second, etc. may be used to distinguish components, the function or structure of these components is not limited by the ordinal number or component name attached to the front of the component.

[0032] The following embodiments may be partially or fully combined or combined with one another, enabling various technically feasible interconnections and operations. Each embodiment may be implemented independently of the other, or may be implemented together in a related manner.

[0033] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings.

[0034] FIG. 1 is a block diagram showing a free compensation system according to one embodiment of the present invention.

[0035] Referring to FIG. 1, a Mura compensation system according to an embodiment of the present invention may include a Mura imaging device (300) and a virtual reality device (1000).

[0036] The Mura imaging device (300) can capture an image displayed on a virtual reality device (1000). Specifically, the Mura imaging device (300) can measure the luminance or Mura characteristics of pixels. For example, the Mura imaging device (300) can be implemented as a CCD (charged coupled device) camera. However, the present invention is not limited thereto. The Mura imaging device (300) includes a plurality of CCD imaging elements, and each of the CCD imaging elements can generate a luminance value in response to the pixels that emit light.

[0037] The Mura imaging device (300) generates measurement data (MD) including measured luminance values, and can use the measurement data (MD) to calculate compensation values ​​for each pixel or for each predetermined block or area for sample grayscale.

[0038] The mura imaging device (300) can calculate coordinates and mura characteristics for sample areas where the mura characteristics of the display panel (100) of the virtual reality device (1000) appear. The mura imaging device (300) can calculate compensation values ​​for each sample area for the sample grayscale based on the coordinates, mura characteristics, and the luminance distribution of each of the sample areas. These compensation values ​​can be included in compensation data (CVD).

[0039] The Mura imaging device (300) can extract the Mura characteristics of each of at least one plane and generate compensation data (CVD) according to each Mura characteristic.

[0040] The Mura imaging device (300) can extract the Mura characteristics of each of a plurality of planes and store the extracted Mura characteristics in the memory (140) of the virtual reality device (1000). That is, the Mura imaging device (300) can write compensation data (CVD) in the memory (140) of the virtual reality device (1000).

[0041] The virtual reality device (1000) may include a display module, memory (140), and AP (Application Processor, 200).

[0042] The virtual reality device (1000) can display an image in which stains, brightness, etc. are compensated by applying compensation data provided from the Mura imaging device (300) to pixels together with driving data, etc.

[0043] The display module may include a display panel (100), a driving circuit (110, 120), and a driver IC (Driver IC, 130 or less, D-IC).

[0044] The substrate of the display panel (100) may be, but is not limited to, a plastic substrate, a thin glass substrate, or a metal substrate. The display panel (100) may be, but is not limited to, a panel having a rectangular structure having a length in a first direction, a width in a second direction, and a thickness in a third direction. In Fig. 1, X, Y, and Z may be the first direction, the second direction, and the third direction, respectively.

[0045] If the display panel (100) is a liquid crystal panel, a backlight unit (BLU) may be placed under the display panel (100). If the display panel (100) is a self-luminous panel, which is an electroluminescent panel, a separate light source such as a backlight unit is not required.

[0046] The display area (AA) of the display panel (100) includes a pixel array that displays an input image. The pixel array includes a plurality of data lines (102), a plurality of gate lines (103) that intersect the data lines (102), and pixels (101) connected to the data lines (102) and the gate lines (103).

[0047] Each pixel (101) can be divided into a red sub-pixel, a green sub-pixel, and a blue sub-pixel for color implementation. Each pixel may further include a white sub-pixel. For example, in a liquid crystal display panel, the pixels include a liquid crystal cell. In an electroluminescent panel, the pixels include a light-emitting element such as an OLED. Each sub-pixel includes a pixel circuit for driving the liquid crystal cell or the light-emitting element.

[0048] The driving circuit (110, 120) can write source data of an input image to pixels of the display panel (100) under the control of the D-IC (130). The driving circuit (110, 120) can be referred to as a driving circuit (110, 120) of the display panel (100). The driving circuit (110, 120) can include a data driving unit (110) and a gate driving unit (120).

[0049] In a wearable terminal or mobile device, the D-IC (130), data driver (110), etc. can be integrated into one IC.

[0050] The data driving unit (110) receives the source data of the input image as a digital signal from the D-IC (130) and outputs a data voltage. The data driving unit (110) converts the source data of the input image into a gamma compensation voltage using a DAC (Digital to Analog Converter) and outputs the data voltage.

[0051] The gate driver (120) may be placed in a non-display area (NA) outside the display area (AA) of the display panel (100), or at least part of the gate driver (120) may be placed in the display area (AA). The gate driver (120) may be integrated into a separate gate driver IC and electrically connected to the gate lines (103) of the display panel (100).

[0052] The gate driver (120) sequentially outputs pulses of gate signals to the gate lines under the control of the D-IC (130). The gate driver (120) can sequentially supply pulses of gate signals to the gate lines (103) by shifting the pulses of the gate signals using a shift register.

[0053] The gate driver (120) can, under the control of the D-IC (130), when the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, supply different pulses of gate signals to each of the gate lines arranged in the first GGS area having the original resolution of the first image and different pulses of gate signals to each of the gate lines arranged in the second GGS area having a lower resolution than the original resolution of the first image.

[0054] For example, the gate driver (120) can sequentially supply a pulse of one gate signal to each gate line arranged in the first GGS area when the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on under the control of the D-IC (130).

[0055] The gate driver (120) can, under the control of the D-IC (130), simultaneously supply a pulse of one gate signal to each of two gate lines among the gate lines arranged in the second GGS region when the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on. This is not limited thereto, and a detailed description thereof will be provided later.

[0056] The D-IC (130) receives source data of an input image and a timing signal synchronized with the data from the AP (Application Processor, 200). The timing signal may include a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), a data enable signal (DE), a main clock, etc. Since the vertical period and the horizontal period can be known by counting the data enable signal (DE), the vertical synchronization signal (Vsync) and the horizontal synchronization signal (Hsync) can be omitted. The vertical synchronization signal (Vsync) has a cycle of one frame period. The horizontal synchronization signal (Hsync) and the data enable signal (DE) have cycles of one horizontal period (1H).

[0057] The D-IC (130) can control the operation timing of the driving circuit (110, 120) based on the timing signal (Vsync, Hsync, DE) received from the AP (Application Processor, 200).

[0058] In addition, the D-IC (130) may include a Mura compensation device (131). When the virtual reality device (1000) is in the FRD (Foveated Rendering Display) off state, the D-IC (130) may receive a first image, which is an original image, from the AP (200). Here, the original image may be an image having substantially the same size and resolution as an image captured by the Mura imaging device (300) on the display panel (100) of the virtual reality device (1000).

[0059] D-IC (130) can receive a second image, which is a compressed image that compresses the original image, when the virtual reality device (1000) is FRD (Foveated Rendering Display) On.

[0060] Here, the compressed image can be formed into a smaller size than the original image by compressing the original image horizontally and vertically. The resolution of some areas of the compressed image may be substantially the same as or lower than that of the original image. A detailed explanation of this will be provided later.

[0061] The memory (140) is detachably mounted on a part of the virtual reality device (1000) and can be electrically connected to the Mura imaging device (300) and the D-IC (130). The memory (140) can be a storage medium in which stored information is maintained even when power is turned off and in which read / write is freely possible. For example, the memory (140) can be a flash memory, but is not limited thereto, and the memory (140) can also be implemented as a random-access memory (RAM) such as a static RAM (SRAM).

[0062] The memory (140) can receive and store compensation data (CVD) from the Mura imaging device (300). For example, the memory (140) can store compensation data corresponding to each pixel or each block of pixels. The memory (140) can provide the stored compensation data to the D-IC (130).

[0063] The memory (140) can classify various data related to compensation data according to predetermined reference conditions and store the classified data in a lookup table (LUT). The memory (140) can provide the compensation data stored in the lookup table (LUT) to the D-IC (130).

[0064] The AP (200) can scale a video signal from a video source to match the resolution of the display panel (100) and transmit the same to the D-IC (130) along with a timing signal. The AP (200) may be referred to as a host system. However, the present invention is not limited thereto, and the AP (200) can transmit source data of an input video to the D-IC (130) via a video transmission interface. The video transmission interface may include a Mobile Industry Processor Interface (MIPI).

[0065] The AP (200) can be electrically connected to the D-IC (130) via a flexible printed circuit, for example, a flexible printed circuit (FPC). The D-IC (130) can be bonded onto the display panel (100) in a COG (Chip on glass) process. For example, the D-IC (130) can be a COF (Chip on film) mounted on a flexible circuit film. The COF can be bonded to data pads arranged in a non-display area of ​​the display panel (100) in a bonding process and electrically connected to data lines on the display panel (100).

[0066] In addition, the AP (200) can scale the original image, which is a video signal from the virtual reality device (1000), to the resolution of the display panel (100) of the virtual reality device (1000) and transmit it to the D-IC (130) along with a timing signal.

[0067] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned off, the AP (200) can scale the original image to fit the resolution of the display panel (100) of the virtual reality device (1000) without processing and transmit it to the D-IC (130).

[0068] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the AP (200) can compress the original image scaled to fit the resolution of the display panel (100) of the virtual reality device (1000) and transmit it to the D-IC (130).

[0069] FIG. 2 is a diagram illustrating an AP and a D-IC according to an embodiment of the present invention. FIG. 3 is a diagram showing a focus area, a peripheral area, a first GGS area, and a second GGS area according to an embodiment of the present invention. FIG. 4 and FIG. 5 are diagrams representing the first GGS area and the second GGS area with a plurality of lines according to an embodiment of the present invention.

[0070] Referring to FIGS. 2 to 5, the D-IC (130) can be electrically connected to the AP (200) and the memory (140). The D-IC (130) can receive an original image or a compressed image from the AP (200) as the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on or off. The present invention is not limited thereto, and the FRD (Foveated Rendering Display) can be turned on or off even during the operation of the virtual reality device (1000) (while the user is using it).

[0071] D-IC (130) can receive compensation data for the original image from the memory (140). A detailed description of this will be provided later.

[0072] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned off, the AP (200) can transmit the original image scaled to the resolution of the display panel (100) of the virtual reality device (1000) to the D-IC (130).

[0073] For example, when the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned off, the AP (200) can receive the first image, which is the original image, from the virtual reality device (1000) and track the user's eye movements in real time. The first image can be defined as an original image of full resolution.

[0074] As illustrated in FIG. 3, when the first image is transmitted, the AP (200) can track the user's eye movements in real time and, based on this, divide or set the first image into a focus area and a peripheral area.

[0075] Here, the focus area can be called ROI (Region Of Interest). The focus area of ​​the left eye can be set to L_ROI, and the focus area of ​​the right eye can be set to R_ROI. Fig. 3 (a) shows a case of 1 panel 2eye (e.g., one panel is responsible for both eyes), and it shows it rotated 90 degrees. It is not limited to this, and Fig. 3 (b) shows a case of 1 panel 1eye (e.g., one panel is responsible for one eye).

[0076] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the AP (200) can compress the original image scaled to fit the resolution of the display panel (100) of the virtual reality device (1000) and transmit it to the D-IC (130).

[0077] As illustrated in FIG. 4, the AP (200) can express the focus area and the surrounding area as the first GGS area and the second GGS area.

[0078] For example, the focus area of ​​the first image may be referred to as the first GGS area. For example, the focus area of ​​the left eye of the first image may be the first GGS area and include lines 2 and 3, and the focus area of ​​the right eye of the first image may be the first GGS area and include lines 6 and 7.

[0079] The surrounding area of ​​the first image may be referred to as the second GGS area. For example, the surrounding area of ​​the first image may be the second GGS area and may include line 0, line 1, line 4, line 5, line 8, and line 9.

[0080] For example, the first image may be sequentially formed as a second GGS region, a first GGS region, a second GGS region, a first GGS region, and a second GGS region in the vertical direction. This is not limited thereto, and the first image may be sequentially formed as a second GGS region, a first GGS region, and a second GGS region.

[0081] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the first image can be compressed into a second image having a smaller size than the first image, and provided to the D-IC (130).

[0082] When compressing a first image into a second image, the AP (200) can compress the first image by differentiating the resolutions for the focus area and the surrounding area. For example, the AP (200) can compress the first image into a Vertical Foveated Image.

[0083] For example, as shown in (a) of Fig. 4, the first image can be expressed as lines 0 to 9. Here, lines 0 to 9 can be data scan lines or gate lines.

[0084] The second GGS region, which is a peripheral region of the first image, may include lines 0, 1, 4, 5, 8, and 9. The first GGS region, which is a focal region of the first image, may include lines 2, 3, 6, and 7.

[0085] As shown in (b) of Fig. 4, the second image is expressed as lines 0 to 9, and can be expressed as a compressed surrounding area of ​​the first image.

[0086] For example, the surrounding area of ​​the second image can have a relatively lower resolution by compressing the second GGS area, which is the surrounding area of ​​the first image, into one line with lines 0 and 1, into one line with lines 4 and 5, and into one line with lines 8 and 9.

[0087] The focus area of ​​the second image is the focus area of ​​the first image, the first GGS area includes lines 2, 3, 6, and 7, and can maintain resolution.

[0088] When AP (200) compresses line 0 and line 1 in the second GGS area into one line, the resolution of the compressed line can be set to one of the resolutions of line 0, line 1, or the average resolution of line 0 and line 1.

[0089] AP (200) can compress the focus area of ​​the first image to the same resolution as the original image, and compress the peripheral area of ​​the first image to a lower resolution than the original image. The peripheral area of ​​the first image can be downscaled and compressed to a lower resolution.

[0090] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the AP (200) can maintain the resolution of the central region (region of interest, foveal region) of the first image at the original resolution and original size based on the vertical direction. When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the AP (200) can lower the resolution of the upper region and the lower region, which are peripheral regions, of the first image based on the vertical direction than the original resolution, and compress the first image to be smaller than the original size.

[0091] The focal area of ​​the compressed second image may be an area having the original resolution of the first image. The peripheral area of ​​the second image may be an area having a resolution that is downscaled by 1 / N of the original image of the remaining area excluding the focal area of ​​the first image. Here, N is an integer greater than 2. The focal area of ​​the second image may be an area having a higher resolution than the peripheral area of ​​the second image.

[0092] As described above, when the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the AP (200) can compress a full-size first image into a second image having a smaller size than the first image.

[0093] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the AP (200) can provide a second image that is a compressed version of the first image to the D-IC (130). When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the AP (200) can reduce the image transmission bandwidth / transmission amount by transmitting a second image with a lower resolution by downscaling the peripheral area of ​​the first image.

[0094] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned off, the D-IC (130) can receive a first image from the AP (200) and compensation data from the memory (140). When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the D-IC (130) can receive a second image from the AP (200) and compensation data from the memory (140). The compensation data can include a compensation value that can correct a luminance deviation or mura characteristic based on the full resolution of the first image, position coordinates where the luminance deviation or mura occurs, etc.

[0095] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the D-IC (130) receives and analyzes the second image and compensation data, and can restore the second image to a third image based on the analyzed results. This may be applicable in the case of a low-power design. Here, the third image may be an image in which a portion of the second image is restored to the resolution of the original image.

[0096] It is not limited thereto, and in some cases, when the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the D-IC (130) may receive and analyze each of the second image and compensation data, and based on the analyzed result, upscale the second image in the horizontal direction to restore it to a third image. Here, the third image may be an image restored to the resolution of the first image by upscaling a portion of the second image in the horizontal direction.

[0097] For example, the D-IC (130) can restore the peripheral area of ​​the second image, which has a resolution downscaled by 1 / N, to the third image, which is the original resolution of the first image. Since the focal area of ​​the second image has a resolution substantially identical to that of the focal area of ​​the first image, there is no need for restoration.

[0098] D-IC (130) can restore the surrounding area of ​​the second image to a resolution substantially the same as that of the original image.

[0099] As shown in Fig. 5, the third image can be expressed as line 0, line 1, line 2, line 3, line 4, line 5, line 6, line 7, line 8, and line 9.

[0100] The first GGS region may be a region where the focus region and the surrounding region of the second image are restored to the resolution of the original image. Accordingly, the first GGS region may be a region with a resolution substantially identical to the resolution of the original image. The first GGS region may be expressed as lines 2, 3, 6, and 7.

[0101] The second GGS region may be any region other than the first GGS region. Therefore, the second GGS region may be a downscaled region with a lower resolution than the original image. The second GGS region may be represented by lines 0, 1, 4, 5, 8, and 9.

[0102] For example, referring to FIG. 3, the third image may be sequentially formed in the vertical direction as a second GGS region, a first GGS region, and a second GGS region, or may be sequentially formed as a second GGS region, a first GGS region, a second GGS region, a first GGS region, and a second GGS region.

[0103] The D-IC (130) controls the gate driver (120) to supply a pulse of a gate signal to each of the gate lines, Line 2, Line 3, Line 6, and Line 7, arranged in the first GGS area having the original resolution of the first image, when the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on.

[0104] The D-IC (130) controls the gate driver (120) to supply pulses of one gate signal simultaneously to lines 0 and 1 among the gate lines arranged in the second GGS area having a lower resolution than the original resolution of the first image when the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on. The D-IC (130) controls the gate driver (120) to supply pulses of one gate signal simultaneously to lines 4 and 5, and lines 8 and 9 when the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on.

[0105] As described above, when the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on by controlling the gate driver (120), pulses of the same gate signal are simultaneously supplied to the second GGS region for every two gate lines, and pulses of different gate signals are supplied to the first GGS region for every one gate line, so that a brightness difference occurs between the first GGS region and the second GGS region. An offset compensation value can be calculated to compensate for this.

[0106] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the D-IC (130) analyzes compensation data provided from the memory (140) and the third image, detects a luminance deviation or mura characteristic occurring in the third image based on the analyzed result, and calculates an offset compensation value that can adjust the detected luminance deviation or mura characteristic.

[0107] The D-IC (130) can compensate for the third image by adjusting the luminance deviation or mura characteristic detected through the calculated offset FRD.

[0108] For example, the D-IC (130) can extract the luminance deviation or mura characteristics of each display panel (100) or plane displaying the third image, and calculate an offset compensation value based on each luminance deviation or mura. A detailed description thereof will be provided later.

[0109] D-IC (130) can transmit the compressed image to the display panel (100).

[0110] FIG. 6 is a diagram for explaining in detail a Mura compensation device according to an embodiment of the present invention. FIGS. 7 to 9 are diagrams for explaining the operation of a Mura compensation device according to an embodiment of the present invention. FIG. 10 is a diagram for explaining a temperature gain according to an embodiment of the present invention.

[0111] Referring to FIGS. 6 to 9, the D-IC (130) according to an embodiment of the present invention may include a Mura compensation device (131).

[0112] The Mura compensation device (131) may include a compensation unit (131a), a control unit (131b), and a temperature compensation unit (131c).

[0113] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned off, the compensation unit (131a) receives a first image from the AP (200) under the control of the mura compensation device (131), receives compensation data from the memory (140), and compensates for the pixel or block unit of pixels based on this to eliminate the luminance deviation or mura characteristic.

[0114] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the compensation unit (131a) receives a third image from the AP (200) and compensation data from the memory (140) under the control of the Mura compensation device (131), and compensates based on this in units of pixels or blocks of pixels.

[0115] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the compensation unit (131a) compensates for the pixels or block units of pixels of the third image based on the compensation data extracted based on the first image, so many errors may occur during the compensation process. To compensate for this, the Mura compensation device (131) can control the adjustment unit (131b) to calculate an offset compensation value.

[0116] The adjustment unit (131b) can, under the control of the Mura compensation device (131), compare and analyze the compensated data provided in units of pixels or blocks of pixels of the third image based on the compensation data with the preset reference data and calculate an offset compensation value based on the same. The adjustment unit (131b) can apply the calculated offset compensation value to the compensation data by arithmetic operations or addition, subtraction, multiplication, and division to calculate the final compensation data. The final compensation data can be referred to as a compensation value of Demura (Demura IP). A detailed description thereof will be provided later.

[0117] The temperature compensation unit (131c) receives a temperature value from the AP (200) and provides a temperature gain to the calculated final compensation data to compensate for the temperature value.

[0118] The temperature compensation unit (131c) can receive a temperature value measured from the outside or inside of the virtual reality device (1000) from the AP (200) under the control of the Mura compensation device (131) and compare it with a preset reference temperature range.

[0119] The temperature compensation unit (131c) may include at least one temperature sensor. The temperature compensation unit (131c) may be positioned outside the D-IC. The temperature compensation unit (131c) may be electrically connected to the D-IC (130). However, this is not limited to the temperature compensation unit (131c), and the temperature compensation unit (131c) may be connected to the AP (200).

[0120] For example, if the temperature compensation unit (131c) is connected to the AP (200), the AP (200) can provide the current temperature value of the virtual reality device (1000) to the D-IC (130). Since the brightness of the display of the virtual reality device (1000) varies depending on the temperature, it is necessary to adjust the compensation intensity according to the temperature.

[0121] As shown in Figure 10, it expresses that the temperature gain changes depending on the temperature, with the horizontal direction representing the temperature and the vertical direction representing the temperature gain.

[0122] The temperature compensation unit (131c) determines that the brightness deviation or intensity of the Mura characteristic may vary depending on the temperature when the temperature value is outside the preset reference temperature range under the control of the Mura compensation device (131), and provides a temperature gain capable of compensating for this to the calculated final compensation data to compensate or adjust it.

[0123] Although not shown, the Mura compensation device (131) may further include a luminance limiter. The luminance limiter may compare the final compensation data provided from the adjustment unit (131b) with a reference luminance. For example, if the luminance of the final compensation data is higher than the reference luminance, the luminance limiter may adjust the luminance of the final compensation data to a lower level.

[0124] The luminance limiter can reduce luminance issues by limiting the luminance of the final compensation data to be substantially equal to or lower than the reference luminance.

[0125] As shown in Figure 7, the vertical direction of the graph represents luminance, and the horizontal direction represents input gray.

[0126] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned off, the mura compensation device (131) can control and compensate for the brightness by operating as follows.

[0127] If one pixel of the display panel (100) of the virtual reality device (1000) is 180 gray, the actual brightness of one pixel can produce the brightness of point A.

[0128] If the target luminance of one pixel is the brightness of point B, 20 gray, which is compensation data for 180 gray, can be compensated to obtain the brightness of point B at 180 gray for one pixel. As a result, one pixel becomes 200 gray, and can have the brightness of point C.

[0129] That is, when compensation data is applied to one pixel, the brightness of one pixel can be close to the target brightness.

[0130] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the Mura compensation device (131) can be controlled to compensate for the decrease in brightness by operating as follows.

[0131] One pixel of the display panel (100) of the virtual reality device (1000) is 180 gray, and the actual brightness of one pixel can produce the brightness of point A.

[0132] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the target luminance of one pixel may not reach the target luminance even if the compensation data of 20 gray is compensated for 180 gray for one pixel to achieve the brightness of point B.

[0133] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the Mura compensation device (131) can compensate the compensation data of 20 grays in the second GGS area (down-scaled area) and then additionally apply the calculated offset compensation value.

[0134] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the Mura compensation device (131) compensates by adding an offset compensation value calculated to 20 gray, which is compensation data, so that the brightness of one pixel can be brought close to the target brightness.

[0135] As described above, compensation data can be applied to the compensation data by arithmetic operations or addition, subtraction, multiplication, or division, taking luminance into account. The offset compensation value can be applied to the compensation data by arithmetic operations or addition, subtraction, or multiplication, taking luminance and compensation data into account.

[0136] As illustrated in FIGS. 8 and 9, when the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the mura compensation device (131) compares and analyzes compensation data provided from the memory (140) and the third image with preset reference data, detects a luminance deviation or mura characteristic occurring in the third image based on the analyzed result, and calculates an offset compensation value that can adjust the detected luminance deviation or mura characteristic.

[0137] The mura compensation device (131) can compensate for the third image by adjusting the detected luminance deviation or mura characteristic through the calculated offset compensation value.

[0138] Fig. 11 is a diagram for explaining in detail a Mura compensation device according to another embodiment of the present invention. Fig. 12 is a diagram for explaining a coordinate adjustment unit according to another embodiment of the present invention.

[0139] Referring to FIGS. 11 and 12, the D-IC (230) according to an embodiment of the present invention may include a Mura compensation device (231).

[0140] The Mura compensation device (231) may include a compensation unit (231a), a coordinate adjustment unit (231b), a temperature check unit (231c), and a brightness limiting unit (231d).

[0141] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned off, the compensation unit (231a) receives a first image from the AP (200) under the control of the mura compensation device (231), receives compensation data from the memory (140), and compensates for the pixel or block unit of pixels based on this to eliminate the luminance deviation or mura characteristic.

[0142] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the compensation unit (231a) receives a third image from the AP (200) and compensation data from the memory (140) under the control of the Mura compensation device (231), and compensates based on this in units of pixels or blocks of pixels.

[0143] When the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the compensation unit (231a) compensates for the pixels or block units of pixels of the third image based on the compensation data extracted based on the first image, so many errors may occur during the compensation process. To compensate for this, the Mura compensation device (231) can control the coordinate adjustment unit (231b) to calculate the position coordinates of the free characteristic.

[0144] The coordinate adjustment unit (231b) can, under the control of the Mura compensation device (231), compare and analyze compensation data provided in units of pixels or blocks of pixels of a third image based on compensation data with preset reference coordinates and calculate a coordinate compensation value based on the compensation data. The coordinate adjustment unit (231b) can adjust the physical line position for the compensation data based on the calculated coordinate compensation value and vertical count.

[0145] For example, as illustrated in FIG. 12, when the FRD (Foveated Rendering Display) of the virtual reality device (1000) is turned on, the coordinate adjustment unit (231b) can adjust the physical line position for the compensation data based on the calculated coordinate compensation value and vertical count under the control of the Mura compensation device (231), thereby calculating the final compensation data.

[0146] Accordingly, the free compensation device (231) calculates the final compensation data based on the coordinate compensation value and the vertical count, and thereby accurately adjusts the position of the luminance deviation or mura characteristic, thereby compensating for the third image.

[0147] The luminance limiting unit (231d) can compare the final compensation data provided from the adjustment unit (231b) with the reference luminance. For example, if the luminance of the final compensation data is higher than the reference luminance, the luminance limiting unit (231d) can adjust the luminance of the final compensation data to be lower.

[0148] The luminance limiter (231d) can reduce luminance issues by limiting the luminance of the final compensation data to be substantially the same as or lower than the reference luminance.

[0149] Since the content of the specification described in the problem to be solved, the means for solving the problem, and the effect described above does not specify the essential features of the claim, the scope of the claim is not limited by the matters described in the content of the specification.

[0150] Since the content of the specification described in the problem to be solved, the means for solving the problem, and the effect described above does not specify the essential features of the claim, the scope of the claim is not limited by the matters described in the content of the specification.

[0151] While the embodiments of the present invention have been described in more detail with reference to the attached drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be implemented without departing from the technical spirit of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to illustrate rather than limit the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

Claims

1. In a virtual reality device having a display panel, The above virtual reality device, A memory that receives and stores compensation data for compensating for luminance deviation or mura characteristics occurring in the display panel from a mura imaging device; An AP (Application Processor) that outputs a first image, which is an original image scaled to the resolution of the display panel, or a second image, which is a compressed version of the original image; and A driver IC (D-IC) having a built-in Mura compensation device that analyzes the first image, the second image, and the compensation data stored in the memory output from the AP (Application Processor), and compensates the second image based on the analyzed result; The above Mura compensation device, When the FRD of the above virtual reality device is turned on, A virtual reality device that analyzes a third image, which is an image that restores the surrounding area of ​​the second image to the resolution of the first image, and the compensation data, and calculates an offset compensation value that can adjust the luminance deviation or mura characteristic detected in the third image based on the analyzed result.

2. In paragraph 1, The first video above is, A first GGS area having the original resolution of the first image, and A second GGS region having a lower resolution than the original resolution of the first image and positioned around the first GGS region, The above driver IC (D-IC) is By controlling the gate driver that supplies a pulse of a gate signal to the gate line arranged on the above display panel, When the above FRD is turned on, the pulse of the gate signal is supplied simultaneously to each of the two gate lines in the second GGS region, A virtual reality device that supplies a pulse of the gate signal to each gate line in the first GGS region.

3. The above-mentioned Mura compensation device, When compensated data is provided in units of pixels or blocks of pixels of the third image based on the above compensation data, the data is compared and analyzed with the preset reference data, and the offset compensation value is calculated based on the data. A virtual reality device that applies the calculated offset compensation value to the compensation data to produce final compensation data.

4. In paragraph 1, The above Mura compensation device, Receive a temperature value measured outside or inside the virtual reality device from the AP and compare it with a preset reference temperature range, A virtual reality device that calculates a temperature gain that can compensate for the intensity of brightness deviation or mura characteristics due to temperature when the temperature value is outside the preset reference temperature range as a result of the comparison.

5. In paragraph 4, The above Mura compensation device, A virtual reality device that compensates for luminance deviation or mura characteristics by applying the calculated temperature gain to the final compensation data.

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