Data generation apparatus and method for brightness unevenness compensation, and display driving circuit

Abstract

The invention provides a data generation apparatus and method for brightness unevenness compensation, and a display driving circuit. A method performed by a luminance unevenness compensation data generation apparatus, the method including: generating optical information of a plurality of pixels of a display panel operating based on test data; generating original luminance unevenness compensation data based on the optical information to compensate for input video data provided to the display panel; extracting a high spatial frequency component and a low spatial frequency component from the original luminance unevenness compensation data; generating a compressed high spatial frequency component by compressing the high spatial frequency component based on a first compression algorithm; generating a compressed low spatial frequency component by compressing the low spatial frequency component based on a second compression algorithm; and storing the compressed high spatial frequency component and the compressed low spatial frequency component in an external storage circuit.

Description

Technical Field

[0001] The present disclosure relates to a display device, and in particular to a brightness unevenness compensation data generating device configured to generate brightness unevenness compensation data for compensating for brightness unevenness (mura) of a display panel, and a display driving circuit configured to compensate for brightness unevenness of a display panel based on the brightness unevenness compensation data. Background Art

[0002] The display panel includes a plurality of pixels operating based on electrical signals, and each of the plurality of pixels is configured to represent the same brightness in response to the same electrical signal.

[0003] However, due to process deviations in the display panel, noise in the electrical signal, etc., even if the display driving circuit controls each of the multiple pixels using the same electrical signal, the brightness represented by each of the multiple pixels may be different. Brightness unevenness that looks like stains, so-called "MURA" (hereinafter referred to as "brightness unevenness (mura)"), may appear in the display panel.

[0004] The display driver circuit can adjust the electrical signal provided to multiple pixels to compensate for the uneven brightness of the display panel. However, as the display panel and the display driver circuit become more integrated, the size of the data used to compensate for the uneven brightness increases. Therefore, it is necessary to reduce the size of the data used to compensate for the uneven brightness. Summary of the invention

[0005] The present disclosure aims to solve the above technical objectives. In particular, a device for generating uneven brightness compensation data for minimizing the amount of information for compensating uneven brightness of a display panel and a display driving circuit for compensating uneven brightness of a display panel based on uneven brightness compensation data are provided.

[0006] According to one aspect of the present disclosure, a method performed by a brightness unevenness compensation data generating device includes: generating optical information of multiple pixels of a display panel operating based on test data; generating original brightness unevenness compensation data based on the optical information to compensate for input video data provided to the display panel; extracting high spatial frequency components and low spatial frequency components from the original brightness unevenness compensation data; generating a compressed high spatial frequency component by compressing the high spatial frequency component based on a first compression algorithm; generating a compressed low spatial frequency component by compressing the low spatial frequency component based on a second compression algorithm; and storing the compressed high spatial frequency component and the compressed low spatial frequency component in an external storage circuit.

[0007] According to one aspect of the present disclosure, a display driving circuit for controlling a display panel includes: a first decompression circuit, the first decompression circuit being configured to generate first brightness unevenness compensation data by decompressing first compressed brightness unevenness compensation data; a second decompression circuit, the second decompression circuit being configured to generate second brightness unevenness compensation data by decompressing second compressed brightness unevenness compensation data; a brightness unevenness compensation data merging circuit, the brightness unevenness compensation data merging circuit being configured to generate third brightness unevenness compensation data by merging the first brightness unevenness compensation data and the second brightness unevenness compensation data; and a brightness unevenness compensation circuit, the brightness unevenness compensation circuit being configured to generate output video data corresponding to input video data provided from an external device based on the third brightness unevenness compensation data, wherein the spatial frequency of the first brightness unevenness compensation data is higher than the spatial frequency of the second brightness unevenness compensation data.

[0008] According to one aspect of the present disclosure, a device for generating data for compensating uneven brightness includes: an optical measurement circuit configured to generate optical information including multiple brightness values ​​of multiple pixels on a display panel operating based on test data; a spatial frequency component extraction circuit configured to extract a high spatial frequency component of the optical information and a low spatial frequency component of the optical information from the optical information based on the multiple brightness values; a first compensation data generation circuit configured to generate first brightness unevenness compensation data corresponding to the multiple pixels based on the high spatial frequency component of the optical information; a second compensation data generation circuit configured to generate second brightness unevenness compensation data corresponding to the multiple pixels based on the low spatial frequency component of the optical information; a first compression circuit configured to compress the first brightness unevenness compensation data based on a first compression algorithm and provide the compressed first brightness unevenness compensation data to an external device; and a second compression circuit configured to compress the second brightness unevenness compensation data based on a second compression algorithm and provide the compressed second brightness unevenness compensation data to the external device. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0010] Figure 1 A display device according to an embodiment of the present disclosure is shown;

[0011] Figure 2 A method for generating a Figure 1A brightness unevenness compensation system that provides brightness unevenness compensation data;

[0012] Figure 3 Shown in more detail Figure 2 The operation of the compensation data generating circuit;

[0013] Figure 4 The embodiment of the present disclosure is configured to generate Figure 1 A brightness unevenness compensation system that provides brightness unevenness compensation data;

[0014] Figure 5 The embodiment implemented according to the embodiment is shown Figure 4 A spatial frequency component extraction circuit;

[0015] Figure 6 Shows Figure 4 The original brightness unevenness compensation data;

[0016] Figure 7 Shown according to Figure 6 The magnitude of the compensation value of the column number of the first row of the original uneven brightness compensation data;

[0017] Figure 8 Shows from Figure 6 The magnitude of the compensation value of the low spatial frequency component extracted from the first row of the original brightness unevenness compensation data;

[0018] Fig. 9 Shows Figure 4 The relationship between the original brightness unevenness compensation data, the low spatial frequency components and the high spatial frequency components;

[0019] Fig.10 Shows from Figure 6 A magnitude of a compensation value of a high spatial frequency component extracted from a first row of the original brightness unevenness compensation data;

[0020] Fig.11 The embodiment implemented according to the embodiment is shown in more detail Figure 4 part of the configuration;

[0021] Fig.12 Shows Fig.11 The bit width reduction module operation;

[0022] Fig.13 is a table showing a compression ratio for uneven brightness compensation data according to an embodiment of the present disclosure;

[0023] Fig.14 Shows Figure 4 operation of a device for generating uneven brightness compensation data;

[0024] Fig.15 Shown in more detail Fig.14 Operation S130;

[0025] Fig.16 The embodiment according to the present disclosure is shown Figure 1 The operation of the display driving circuit;

[0026] Fig.17 Shows Fig.16 The operation of the display driving circuit;

[0027] Fig.18 The embodiment implemented according to the embodiment is shown Figure 4 A spatial frequency component extraction circuit;

[0028] Fig.19 Another embodiment of the present disclosure is shown. Figure 1 A brightness unevenness compensation system that provides brightness unevenness compensation data;

[0029] Fig. 20 Shows Fig.19 Optical information;

[0030] FIG. 21A to FIG. 21C They are shown respectively Fig. 20 optical information, low spatial frequency components of the optical information, and high spatial frequency components of the optical information;

[0031] Fig. 22 Shows Fig.19 operation of a device for generating uneven brightness compensation data;

[0032] Fig.23 Another embodiment according to the present disclosure is shown. Figure 1 operation of a display driving circuit; and

[0033] Fig.24 Shows Fig.23 The operation of the display driver circuit. DETAILED DESCRIPTION

[0034] In the following detailed description, only certain embodiments of the present invention are shown and described by way of illustration. Details such as specific configurations and structures are provided only to provide an overall understanding of the embodiments of the present disclosure. Therefore, variations of the embodiments described herein may be performed by those skilled in the art without departing from the technical spirit and scope of the present disclosure. In addition, for the sake of clarity and brevity, descriptions of well-known functions and structures are omitted. Configurations in the following figures or detailed descriptions may be associated with components other than those shown in the figures or described in the detailed description. As used herein, these terms are defined according to the functions of the present disclosure and are not limited to any particular function. The definition of a term may be determined based on what is described in the detailed description.

[0035] Components described with reference to terms, such as drivers or blocks used in the detailed description, can be implemented in software, hardware, or a combination thereof. For example, software can be machine code, firmware, embedded code, and application software. For example, hardware can include circuits, electronic circuits, processors, computers, integrated circuit cores, pressure sensors, inertial sensors, microelectromechanical systems (MEMS), passive devices, or a combination thereof.

[0036] In one or more embodiments of the present disclosure described below, a hardware method is described as an example. However, since one or more embodiments of the present disclosure include techniques using both hardware and software, various embodiments of the present disclosure do not exclude a software-based method.

[0037] In addition, in the present disclosure, in order to determine whether a specific condition is satisfied or achieved, the expression of greater than or less than may be used, but this is merely a description for expressing an example and does not exclude the description of greater than or equal to or less than or equal to. The condition described as "greater than or equal to" may be replaced with "greater than", the condition described as "less than or equal to" may be replaced with "less than", and the condition described as "greater than or equal to and less than" may be replaced with "greater than and less than or equal to". In addition, hereinafter, "A" to "B" refers to at least one of the elements starting from A (including A) and to B (including B).

[0038] The terms "include" and "comprising" and their derivatives refer to unlimited inclusion. The term "or" is an inclusive term meaning "and / or". The phrase "associated" and its derivatives refer to including, being included, interconnected, containing, being contained within, connected to or with ... connected, coupled to or coupled with ..., communicable, cooperating with ..., interlaced with ..., juxtaposed, close to, being combined to or with ... combined, having, having the attributes of ..., having a relationship with or with it, etc. The term "controller" refers to any device, system or part thereof that controls at least one operation. Such a controller can be implemented in hardware or a combination of hardware and software and / or firmware. The functionality associated with any particular controller can be centralized or distributed, whether local or remote. When used with a list of items, the phrase "at least one" means that different combinations of one or more of the listed items can be used, and only one item in the list may be required. For example, "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, A and B and C, and any variations thereof. The expression "at least one of a, b, or c" may indicate only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof. Similarly, the term "set" means one or more. Thus, a set of items may be a single item, or a set of two or more items.

[0039] As shown in the accompanying drawings, embodiments can be described and illustrated according to the blocks implementing one or more functions described.These blocks, which may be referred to as compression modules, bit width reduction modules, etc., in this article, can be physically implemented by analog and / or digital circuits, including one or more of logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, etc., and can also be implemented or driven by software and / or firmware (configured to perform functions or operations described herein).For example, the circuit can be implemented in one or more semiconductor chips, or implemented on substrate supports such as printed circuit boards.The circuit included in the block can be implemented by dedicated hardware, or by a processor (for example, one or more programmed microprocessors and related circuit systems), or by a combination of dedicated hardware that performs some functions of the block and a processor that performs other functions of the block.Each block of the embodiment can be physically divided into two or more discrete blocks that interact with each other.Similarly, the block of the embodiment can be physically combined into more complex blocks.

[0040] Figure 1 is a block diagram showing a display device according to an embodiment of the present disclosure. Figure 1The display device DPD may include a display driving circuit 100 and a display panel DP. The display device DPD may correspond to an electronic device configured to display image information, such as a monitor, a TV, a laptop, a tablet PC, a smartphone, and a navigation system.

[0041] The display panel DP may be connected to the display driving circuit 100 via a plurality of gate lines and a plurality of data lines. The display panel DP may include a plurality of pixels connected to the plurality of gate lines and the plurality of data lines. Each of the plurality of pixels may display one of the primary colors in response to an electrical signal provided by the display driving circuit 100. The primary colors may include red, green, and blue. However, the scope of the present disclosure is not limited thereto.

[0042] In an embodiment, the display panel DP may be one of various types of panels such as a liquid crystal display (LCD) panel, an organic light emitting display (OLED) panel, an electrophoretic display panel, and an electrowetting display panel. However, the scope of the present disclosure is not limited thereto.

[0043] In the embodiment, even if the display driving circuit 100 controls a plurality of pixels of the display panel DP based on the same grayscale and the same data signal, the brightness represented by the plurality of pixels may be different. In other words, brightness non-uniformity, i.e., so-called brightness unevenness or speckle, may occur on the display panel DP due to process deviation of the DP, noise in the electrical signal, etc.

[0044] The display driving circuit 100 can compensate for uneven brightness of the display panel DP. More specifically, the display driving circuit 100 can adjust the electrical signal to be provided to the display panel DP so that each of the plurality of pixels of the display panel DP represents the correct brightness (i.e., the expected brightness). In the following description, the configuration and operation of the display driving circuit 100 for compensating for uneven brightness of the display panel DP will be described in detail.

[0045] like Figure 1 As shown, the display driving circuit 100 may include a brightness unevenness compensator 110 , a storage circuit 120 , a timing controller 130 , a gate driver 140 , and a source driver 150 .

[0046] The uneven brightness compensator 110 may receive input video data VDT_in from one of various types of electronic devices, such as an application processor (AP) or a graphics processing unit (GPU). In this case, the input video data VDT_in may include data for controlling each of a plurality of pixels on the display panel DP.

[0047] The storage circuit 120 may store one or more “brightness unevenness compensation data” MCD. An embodiment will be described below in which the storage circuit 120 is included in the display driving circuit 100. However, the scope of the present disclosure is not limited thereto, and the storage circuit 120 may exist outside the display driving circuit 100.

[0048] The uneven brightness compensation data MCD may include compensation values ​​for pixels of the display panel DP. In an embodiment, the uneven brightness compensation data MCD may be implemented in the form of a lookup table containing compensation values. An embodiment in which the uneven brightness compensation data MCD is implemented in the form of a lookup table will be described below. However, the scope of the present disclosure is not limited thereto.

[0049] In addition, an embodiment in which a single compensation value is applied to the uneven brightness compensation for a single pixel will be described below. However, the scope of the present disclosure is not limited thereto, and a single compensation value may be used for uneven brightness compensation for a plurality of pixels adjacent to each other, for example. For example, one compensation value may be used to compensate for uneven brightness of four adjacent pixels forming a 2×2 matrix structure or nine adjacent pixels forming a 3×3 matrix structure. In other words, the scope of the present disclosure is not limited to a specific manner of using the compensation value included in the uneven brightness compensation data MCD.

[0050] In an embodiment, the storage circuit 120 may store the uneven brightness compensation data MCD in a compressed form. Therefore, the capacity of the uneven brightness compensation data MCD stored in the storage circuit 120 may be reduced.

[0051] In an embodiment, the storage circuit 120 may store the uneven brightness compensation data MCD in a compressed form for each spatial frequency component. For example, the storage circuit 120 may store a plurality of uneven brightness compensation data compressed by different compression algorithms for different spatial frequencies. In this case, an optimal compression algorithm may be applied to each component of the spatial frequency, so that the capacity of the uneven brightness compensation data MCD stored in the storage circuit 120 may be minimized. A specific manner of storing the uneven brightness compensation data in a compressed form in the storage circuit 120 for each spatial frequency component will be described in detail with reference to the following drawings.

[0052] In an embodiment, the storage circuit 120 may store a plurality of brightness unevenness compensation data MCD for different gray levels. In this case, the brightness unevenness compensator 110 may interpolate the compensation values ​​stored in the plurality of brightness unevenness compensation data to determine a compensation value corresponding to the gray level in the input video data VDT_in. However, a manner in which one brightness unevenness compensation data for one gray level is stored in the storage circuit 120 and used will be described. However, the scope of the present disclosure is not limited thereto.

[0053] In an embodiment, the storage circuit 120 may store a plurality of brightness unevenness compensation data MCD for sub-pixels of different colors. However, the following will describe how one brightness unevenness compensation data corresponding to a sub-pixel of one color is stored in the storage circuit 120 and used. In the following description, a pixel on the display panel DP may refer to a sub-pixel of the same color. However, the scope of the present disclosure is not limited thereto.

[0054] The uneven brightness compensator 110 may receive uneven brightness compensation data MCD from the storage circuit 120. The uneven brightness compensator 110 may perform uneven brightness compensation on the input video data VDT_in based on the uneven brightness compensation data MCD. That is, based on the uneven brightness compensation data MCD, the uneven brightness compensator 110 may generate output video data VDT_out from the input video data VDT_in. Fig.16 and Fig.17 The specific configuration and operation of the uneven brightness compensator 110 are described in more detail.

[0055] In one embodiment, the uneven brightness compensator 110 may perform a weighted sum operation on the data for each of the plurality of pixels represented by the input video data VDT_in and the compensation value for each of the plurality of pixels represented by the uneven brightness compensation data MCD to generate the output video data VDT_out. However, the scope of the present disclosure is not limited thereto, and the uneven brightness compensation operation may be performed by using any type of operation, such as a summation operation and a product operation.

[0056] In an embodiment, when the uneven brightness compensation data MCD is in a compressed format, the uneven brightness compensator 110 may decompress the uneven brightness compensation data MCD and then perform a uneven brightness compensation operation on the input video data VDT_in.

[0057] The timing controller 130 may receive the output video data VDT_out from the uneven brightness compensator 110. The timing controller 130 may control the gate driver 140 and the source driver 150 based on the output video data VDT_out.

[0058] The gate driver 140 may be connected to the display panel DP via a plurality of gate lines, and the source driver 150 may be connected to the display panel DP via a plurality of data lines. The source driver 150 may control the plurality of data lines connected to the display panel DP based on a control signal provided by the timing controller 130 or data (e.g., output video data VDT_out) provided by the timing controller 130. In other words, in an embodiment, each of the pixels of the display panel DP may operate in response to the output video data VDT_out (i.e., data compensated for uneven brightness) instead of the input video data VDT_in.

[0059] In an embodiment, the display panel DP may include a sandy type uneven brightness region 'MA_sandy' and a cloudy type uneven brightness region 'MA_cloudy'. Figure 1 As shown. The sandy uneven brightness area MA_sandy may include some non-adjacent pixels having different brightness from other pixels on the display panel DP. The cloudy uneven brightness area MA_cloudy may include a plurality of adjacent pixels having different brightness from other pixels on the display panel DP. In this case, the sandy uneven brightness area MA_sandy may be visible to the user as an “uneven brightness point” on the display panel DP, while the cloudy uneven brightness area MA_cloudy may be visible to the user as an “uneven brightness plane” on the display panel DP, as shown. Figure 1 shown.

[0060] In an embodiment, the compensation values ​​for compensating the cloudy type uneven brightness area MA_cloudy among the compensation values ​​of the uneven brightness compensation data MCD may have a high (or relatively high) correlation with each other. For example, among the uneven brightness compensation values ​​for compensating the cloudy type uneven brightness area MA_cloudy, the uneven brightness compensation values ​​corresponding to the adjacent pixels on the display panel DP may have similar values. On the other hand, among the compensation values ​​of the uneven brightness compensation data MCD, the compensation values ​​for compensating the sandy type uneven brightness area MA_sandy may have less (or relatively low) correlation with each other. For example, each of the uneven brightness compensation values ​​for compensating the sandy type uneven brightness area MA_sandy may be determined independently of whether the corresponding pixel positions are adjacent. In other words, the spatial frequency of the uneven brightness compensation value for compensating the cloudy type uneven brightness area MA_cloudy may be low, while the spatial frequency of the uneven brightness compensation value for compensating the sandy type uneven brightness area MA_sandy may be high.

[0061] In an embodiment, the storage circuit 120 may store a plurality of compressed brightness unevenness compensation data MCD for each size of the spatial frequency (or periodicity). For example, the storage circuit 120 may store a compressed high spatial frequency component and a compressed low spatial frequency component. In this case, the brightness unevenness compensation data stored in the storage circuit 120 may be compressed and stored in a manner optimized for the size of the spatial frequency. Therefore, according to an embodiment of the present disclosure, the data capacity for brightness unevenness compensation operation stored in the storage circuit 120 may be minimized. Figures 2 to 15 A specific method of storing the brightness unevenness compensation data based on spatial frequency compression in the storage circuit 120 is described in more detail.

[0062] Figure 2 is a diagram showing a method for generating a Figure 1 Block diagram of a brightness unevenness compensation system for brightness unevenness compensation data. Figure 1 and Figure 2 The uneven brightness compensation system MCS may include a display panel DP, a display driving circuit 100, and an uneven brightness compensation data generating device 1. The display panel DP and the display driving circuit 100 may be included in a display device DPD. A detailed description of the configuration and functions of the above-mentioned display device DPD will be omitted.

[0063] The display driving circuit 100 can receive test data DATA_test from the outside (such as an external electronic device connected to the uneven brightness compensation system MCS). Based on the test data DATA_test, the display driving circuit 100 can control each of the multiple pixels of the display panel DP to the same brightness. In other words, the display driving circuit 100 can provide signals of the same size to each column of the display panel DP based on the test data DATA_test. More specifically, the source driver 150 can provide signals of the same size to multiple data lines based on the test data DATA_test. In this case, an ideal display panel DP (i.e., a display panel that does not include an uneven brightness area) can be able to exhibit uniform brightness.

[0064] The device 1 for generating data for compensating uneven brightness can identify whether the display panel DP exhibits uniform brightness. In other words, the device 1 for generating data for compensating uneven brightness can identify uneven brightness of the display panel DP. For example, the device 1 for generating data for compensating uneven brightness can include an optical measurement circuit 1a. The optical measurement circuit 1a can generate optical information OPI representing an image output by the display panel DP. In this case, the optical information OPI can include brightness values ​​represented by pixels of the display panel DP.

[0065] The device 1 for generating data for compensating uneven brightness may generate information for compensating uneven brightness of the display panel DP based on the optical information OPI. For example, the device 1 for generating data for compensating uneven brightness may include a compensation data generating circuit 1b. Based on the optical information OPI, the compensation data generating circuit 1b may determine a brightness level to be compensated for each pixel of the display panel DP.

[0066] The compensation data generating circuit 1b can generate raw brightness unevenness compensation data MCD_raw indicating the brightness level determined to be compensated for each pixel. Figure 3 The method or manner in which the compensation data generating circuit 1 b determines the brightness level to be compensated for each of the pixels of the display panel DP is described in more detail.

[0067] The device 1 for generating uneven brightness compensation data may compress the original uneven brightness compensation data MCD_raw and store the compressed original uneven brightness compensation data MCD_raw in the display driving circuit 100. For example, the device 1 for generating uneven brightness compensation data may include a compression circuit 1c. The compression circuit 1c may compress the original uneven brightness compensation data MCD_raw to generate compressed uneven brightness compensation data MCD_comp. The compression circuit 1c may transmit the compressed uneven brightness compensation data MCD_comp to the storage circuit 120 of the display driving circuit 100, and thus, the compressed uneven brightness compensation data MCD_comp may be stored in the storage circuit 120 of the display driving circuit 100.

[0068] In this way, the storage circuit 120 can store the compressed brightness unevenness compensation data MCD_comp. In this case, the display driving circuit 100 can decompress the compressed brightness unevenness compensation data MCD_comp to generate the original brightness unevenness compensation data MCD_raw, and can perform the brightness unevenness compensation operation on the input video data VDT_in based on the original brightness unevenness compensation data MCD_raw. However, the scope of the present disclosure is not limited to this.

[0069] Figure 3 is shown in more detail Figure 2 FIG. 1 is a diagram showing the operation of the compensation data generating circuit 1b. Figures 1 to 3 , the compensation data generating circuit 1b may obtain the brightness information of each of the pixels PX of the display panel DP based on the optical information OPI.

[0070] For example, the compensation data generating circuit 1b can identify based on the optical information OPI that the pixels at [first row R1, tenth column C10], the pixels at [R4, C7], the pixels at [R9, C2 to C4], and the pixels at [R10, C1 to C4] (hereinafter, the pixels shown in dark gray) located at the display panel DP represent the first brightness (corresponding to the value CVa).

[0071] The compensation data generation circuit 1b can identify based on the optical information OPI that the pixel at [R5, C9], the pixel at [R8, C2 to C3], the pixel at [R9, C5] and the pixel at [R10, C5 to C6] (hereinafter, the pixels shown in gray) represent the second brightness (corresponding to CVb).

[0072] Similarly, the compensation data generating circuit 1b can identify, based on the optical information OPI, that the pixel at [R2, C6] (hereinafter, shown as a pixel with horizontal stripes) represents a third brightness (corresponding to CVc), and that the pixel at [R3, C9] (hereinafter, shown as a pixel with vertical stripes) represents a fourth brightness (corresponding to CVd).

[0073] In other words, based on the optical information OPI, the compensation data generating circuit 1 b can recognize brightness unevenness caused by the difference in brightness of pixels on the display panel DP.

[0074] The compensation data generating circuit 1b may generate compensation values ​​for pixels representing brightness higher or lower than a "reference" brightness among pixels located in the first to tenth rows (R1 to R10) and the first to tenth columns (C1 to C10) of the display panel DP based on the optical information OPI. For example, the compensation data generating circuit 1b may generate compensation values ​​(or at least one compensation value) such that all pixels represent the reference brightness.

[0075] An embodiment in which the first brightness is lower than the second brightness, the second brightness is lower than the reference brightness, the reference brightness is lower than the third brightness, and the third brightness is lower than the fourth brightness will be described below. That is, the order is: first brightness < second brightness < reference brightness < third brightness < fourth brightness. However, the scope of the present disclosure is not limited thereto.

[0076] In an embodiment, the compensation data generating circuit 1b may generate raw uneven brightness compensation data MCD_raw including compensation values ​​for pixels having brightness higher than (or lower than) a reference brightness in another embodiment. In this case, pixels corresponding to pixels depicted in dark gray (i.e., Figure 3The area (e.g., a cell of the lookup table) of the original brightness unevenness compensation data MCD_raw corresponding to the pixels depicted in gray (i.e., the pixels representing the second brightness) can store the first compensation value CVa; the area of ​​the original brightness unevenness compensation data MCD_raw corresponding to the pixels depicted in horizontal stripes (i.e., the pixels representing the third brightness) can store the third compensation value CVc; and the area of ​​the original brightness unevenness compensation data MCD_raw corresponding to the pixels represented by vertical stripes (i.e., the pixels representing the fourth brightness) can store the fourth compensation value CVd. In this case, the display driving circuit 100 can control the display panel DP to output an image of uniform brightness based on the four compensation values ​​(CVa, CVb, CVc, and CVd). However, the scope of the present disclosure is not limited thereto.

[0077] Figure 4 is a diagram showing a method configured to generate a Figure 1 A block diagram of a brightness unevenness compensation system MCS of a brightness unevenness compensation data MCD is shown. Figure 1 and Figure 4 The uneven brightness compensation system MCS may include a display panel DP, a display driving circuit 100 and an uneven brightness compensation data generating device 10. Figure 4 As shown, the brightness unevenness compensation data generating device 10 may include an optical measurement circuit 11, a compensation data generating circuit 12, a spatial frequency component extraction circuit 13, a compression circuit #114, and a compression circuit #215. Since the configuration and operation of the display panel DP, the display driving circuit 100, the optical measurement circuit 11, and the compensation data generating circuit 12 are similar to those of the previous reference Figure 2 Those described are similar, so the detailed description will be omitted.

[0078] The spatial frequency component extraction circuit 13 may receive the original uneven brightness compensation data MCD_raw from the compensation data generation circuit 12. The spatial frequency component extraction circuit 13 may extract the high spatial frequency component MCD_HF (from the original uneven brightness compensation data MCD_raw) and the low spatial frequency component MCD_LF (from the original uneven brightness compensation data MCD_raw). That is, the spatial frequency component extraction circuit 13 may classify the high spatial frequency component (e.g., the component for compensating the compensation value of the sandy uneven brightness area MA_sandy) and the low spatial frequency component (e.g., the component for compensating the compensation value of the cloudy uneven brightness area MA_cloudy) from the original uneven brightness compensation data MCD_raw.

[0079] In an embodiment, the spatial frequency component extraction circuit 13 may include a spatial frequency low-pass filter (eg, Figure 5 In this case, the spatial frequency component extraction circuit 13 may provide the original brightness unevenness compensation data MCD_raw to a spatial frequency low-pass filter to extract the low spatial frequency component MCD_LF. Then, the spatial frequency component extraction circuit 13 may extract the high spatial frequency component MCD_HF based on the original brightness unevenness compensation data MCD_raw and the low spatial frequency component MCD_LF. However, the scope of the present disclosure is not limited to any specific implementation method of the spatial frequency component extraction circuit 13. For example, the spatial frequency component extraction circuit 13 may include a spatial frequency high-pass filter. However, an embodiment in which the spatial frequency component extraction circuit 13 includes a spatial frequency low-pass filter will be described below.

[0080] In an embodiment, the spatial frequency component extraction circuit 13 may extract the high spatial frequency component MCD_HF based on the difference between the original brightness unevenness compensation data MCD_raw and the low spatial frequency component MCD_LF. Figure 5 The configuration of the spatial frequency component extraction circuit 13 that extracts the high spatial frequency component MCD_HF based on the difference between the raw brightness unevenness compensation data MCD_raw and the low spatial frequency component MCD_LF is described in more detail.

[0081] In an embodiment, the spatial frequency component extraction circuit 13 may extract the high spatial frequency component MCD_HF based on the difference between the result of compressing and then decompressing the low spatial frequency component MCD_LF (i.e., the result of compressing the low spatial frequency component MCD_LF and decompressing the compressed low spatial frequency component MCD_LF again) and the original brightness unevenness compensation data MCD_raw. In this case, the error caused by compressing and then decompressing the low spatial frequency component MCD_LF may be reflected in the high spatial frequency component MCD_HF. Fig.18 The configuration of the spatial frequency component extraction circuit 13 that extracts the high spatial frequency component MCD_HF (based on the difference between the result of compressing and then decompressing the low spatial frequency component MCD_LF and the original brightness unevenness compensation data MCD_raw) is described in more detail. However, an embodiment in which the spatial frequency component extraction circuit 13 extracts the high spatial frequency component MCD_HF based on the difference between the original brightness unevenness compensation data MCD_raw and the low spatial frequency component MCD_LF will be described below.

[0082] In an embodiment, the capacity of the high spatial frequency component MCD_HF and the low spatial frequency component MCD_LF may be the same. More specifically, for the high spatial frequency component MCD_HF and the low spatial frequency component MCD_LF, the number of compensation values ​​arranged in the row direction may be the same as the number of original uneven brightness compensation data MCD_raw. More specifically, for the high spatial frequency component MCD_HF and the low spatial frequency component MCD_LF, the number of compensation values ​​arranged in the column direction may be the same as the number of original uneven brightness compensation data MCD_raw. That is, the capacity (or, row size and column size) of the original uneven brightness compensation data MCD_raw, the high spatial frequency component MCD_HF and the low spatial frequency component MCD_LF may be equal to each other. However, the scope of the present disclosure is not limited to this.

[0083] like Figure 4 As shown, the compression circuit #1 14 may compress the high spatial frequency component MCD_HF to generate a compressed high spatial frequency component MCD_HF_comp. For example, the compression circuit #1 14 may compress the high spatial frequency component MCD_HF based on a first compression algorithm.

[0084] The compression circuit #2 15 may compress the low spatial frequency component MCD_LF to generate a compressed low spatial frequency component MCD_LF_comp. For example, the compression circuit #2 15 may compress the low spatial frequency component MCD_LF based on a second compression algorithm.

[0085] In one embodiment, the compression algorithms used by the compression circuit #1 14 and the compression circuit #2 15 may be different. In other words, the first compression algorithm and the second compression algorithm may be different. For example, the first compression algorithm may be a compression algorithm with a low compression ratio and a low compression loss (i.e., a high recovery rate), and the second compression algorithm may be a compression algorithm with a high compression ratio. In this case, the capacity of the compressed low spatial frequency component MCD_LF_comp may be smaller than the capacity of the compressed high spatial frequency component MCD_HF_comp.

[0086] The compression circuit #1 14 may transmit the compressed high spatial frequency component MCD_HF_comp and thus store it in the storage circuit 120. The compression circuit #2 15 may transmit the compressed low spatial frequency component MCD_LF_comp and thus store it in the storage circuit 120. Fig.11 The specific configuration and operation of compression circuit #1 14 and compression circuit #2 15 are described in more detail.

[0087] In this way, the storage circuit 120 can store the compressed high spatial frequency component MCD_HF_comp and the compressed low spatial frequency component MCD_LF_comp. In this case, the sum of the capacity of the compressed high spatial frequency component MCD_HF_comp and the compressed low spatial frequency component MCD_LF_comp can be smaller than the previous reference Figure 2 Therefore, according to an embodiment of the present disclosure, the capacity of the storage circuit 120 can be minimized, which is an exemplary advantage of the present disclosure. Fig.16 and Fig.17 The operation of the display driving circuit 100 based on the compressed high spatial frequency component MCD_HF_comp and the compressed low spatial frequency component MCD_LF_comp is described in more detail.

[0088] In an embodiment, Figure 4 An embodiment in which the brightness unevenness compensation data generating device 10 is implemented as a device separated from the display driving circuit 100 is shown, but the scope of the present disclosure is not limited thereto. For example, some configurations of the brightness unevenness compensation data generating device 10 may be included in the display driving circuit 100. More specifically, one or more of the spatial frequency component extraction circuit 13, the compression circuit #1 14, and the compression circuit #2 15 may be included in the display driving circuit 100. In this case, the display driving circuit 100 may store the raw brightness unevenness compensation data MCD_raw in a compressed or uncompressed form as needed (for example, depending on the operating speed or storage capacity of the display driving circuit 100).

[0089] Figure 5 It is shown that the Figure 4 A block diagram of the spatial frequency component extraction circuit 13 is shown. Figure 1 , Figure 4 and Figure 5 , the spatial frequency component extraction circuit 13_1 may include a spatial frequency low-pass filter LPF_SF and a differential circuit DFC. In an embodiment, Figure 5 The spatial frequency component extraction circuit 13_1 in corresponds to Figure 4 The spatial frequency component extraction circuit 13 in.

[0090] The spatial frequency low pass filter LPF_SF may receive the original uneven brightness compensation data MCD_raw and may extract the low spatial frequency component MCD_LF based on the original uneven brightness compensation data MCD_raw.

[0091] The differential circuit DFC may receive the original uneven brightness compensation data MCD_raw and the low spatial frequency component MCD_LF. The differential circuit DFC may extract the high spatial frequency component MCD_HF based on the difference between the original uneven brightness compensation data MCD_raw and the low spatial frequency component MCD_LF. Figures 6 to 10 The operation of the differential circuit DFC is described in more detail.

[0092] In the following description, Figure 4 The spatial frequency component extraction circuit 13 can be similar to Figure 5 However, the scope of the present disclosure is not limited thereto, and the spatial frequency component extraction circuit 13 may be implemented in a manner similar to the following reference Fig.18 The spatial frequency component extraction circuit is described in detail.

[0093] Figure 6 Shows Figure 4 The original brightness unevenness compensation data MCD_raw. Figure 1 , Figures 4 to 6 , the original uneven brightness compensation data MCD_raw may be implemented in the form of a lookup table for the pixels of the display panel DP. The original uneven brightness compensation data MCD_raw may include a plurality of compensation values ​​CV. In this case, each of the plurality of compensation values ​​CV may be arranged in a different cell of the lookup table. In the following description, the plurality of compensation values ​​CV may be arranged in the row direction and the column direction within the original uneven brightness compensation data MCD_raw.

[0094] In addition, the compensation value arranged in the mth row and the nth column of the original uneven brightness compensation data MCD_raw among the plurality of compensation values ​​CV will be referred to as "CVmn". For example, the compensation value arranged in the first row and the second column of the original uneven brightness compensation data MCD_raw will be referred to as "CV12". However, the scope of the present disclosure is not limited thereto.

[0095] Each of the multiple compensation values ​​CV can be used to perform uneven brightness compensation operations on one or more pixels of the display panel DP. In the following description, an embodiment is described in which each of the multiple compensation values ​​CV is used for uneven brightness compensation operations on a pixel of the display panel DP. For example, "CV11" can be used for uneven brightness compensation operations of pixels at [1, 1] (first row, first column) of the display panel DP, and "CV12" can be used for uneven brightness compensation operations of pixels at [1, 2] (first row, second column) of the display panel DP. However, the scope of the present disclosure is not limited to the number of pixels on the display panel DP for which compensation values ​​CV are used. For example, each of the multiple compensation values ​​CV can be used to perform uneven brightness compensation operations on multiple pixels. More specifically, "CV11" can be used for the brightness unevenness compensation operation of pixels arranged at the first and second columns of the first row of the display panel DP and the pixels arranged at the first and second columns of the second row, and "CV12" can be used for the brightness unevenness compensation operation of pixels arranged at the third and fourth columns of the first row of the display panel DP and the pixels arranged at the third and fourth columns of the second row.

[0096] In an embodiment, the arrangement of the plurality of compensation values ​​CV in the lookup table may be determined based on the arrangement of pixels (ie, pixels to be compensated) respectively corresponding to the plurality of compensation values ​​in the display panel DP. However, the scope of the present disclosure is not limited thereto.

[0097] The spatial frequency component extraction circuit 13 may extract high spatial frequency components and low spatial frequency components for each row of the original uneven brightness compensation data MCD_raw. For example, the spatial frequency component extraction circuit 13 may extract high spatial frequency components and low spatial frequency components for the first row ROW1 of the original uneven brightness compensation data MCD_raw based on the compensation value magnitude according to the column number in the first row ROW1 of the original uneven brightness compensation data MCD_raw. However, the scope of the present disclosure is not limited thereto, and the spatial frequency component extraction circuit 13 may be configured to extract high spatial frequency components and low spatial frequency components for each column of the original uneven brightness compensation data MCD_raw.

[0098] In the following, reference will be made to Figure 7 , Figure 8 and Fig.10 An embodiment is described in which the spatial frequency component extraction circuit 13 extracts high spatial frequency components and low spatial frequency components for the first row ROW1 of the original brightness unevenness compensation data MCD_raw. However, the scope of the present disclosure is not limited thereto, and the spatial frequency component extraction circuit 13 may extract high spatial frequency components and low spatial frequency components for predetermined rows and columns of the original brightness unevenness compensation data MCD_raw in a similar manner.

[0099] Figure 7 It shows that according to Figure 6 A graph showing the magnitude of the compensation value of the first row of the column number of the original brightness unevenness compensation data. Figure 7 , the horizontal axis represents the column number of the raw uneven brightness compensation data MCD_raw, and the vertical axis represents the magnitude of the compensation value CV.

[0100] refer to Figure 1 and Figures 4 to 7 , the first row ROW1 of the raw uneven brightness compensation data MCD_raw may store compensation values ​​of variable (non-uniform) magnitudes according to column numbers.

[0101] In an embodiment, each of the compensation values ​​of the raw uneven brightness compensation data MCD_raw may be determined as the sum of (1) a compensation value for compensating the cloudy uneven brightness region MA_cloudy and (2) a compensation value for compensating the sandy uneven brightness region MA_sandy. In this way, each of the compensation values ​​in the raw uneven brightness compensation data MCD_raw may include a high spatial frequency component and a low spatial frequency component.

[0102] In an embodiment, the high spatial frequency component MCD_HF of the original uneven brightness compensation data MCD_raw may refer to a component having a large fluctuation in the magnitude of the compensation value according to the column number. On the other hand, the low spatial frequency component MCD_LF of the original uneven brightness compensation data MCD_raw may refer to a component having a small fluctuation in the magnitude of the compensation value according to the column number. Therefore, the high spatial frequency component MCD_HF and the low spatial frequency component MCD_LF of the original uneven brightness compensation data MCD_raw may be determined based on the magnitudes of the plurality of compensation values ​​and the arrangement of the plurality of compensation values ​​in the lookup table. Figure 8 and Fig.10 The high spatial frequency component MCD_HF and the low spatial frequency component MCD_LF of the raw uneven brightness compensation data MCD_raw are described in more detail.

[0103] The spatial frequency component extraction circuit 13 may perform a spatial frequency low-pass filtering operation to extract a low spatial frequency component with respect to the first row ROW1 of the raw uneven brightness compensation data MCD_raw.

[0104] In an embodiment, the spatial frequency component extraction circuit 13 may perform a spatial frequency low-pass filtering operation by a moving average filtering operation method. For example, the spatial frequency component extraction circuit 13 may extract a low spatial frequency component of the first row ROW1 of the original brightness unevenness compensation data MCD_raw by calculating an average value of compensation values ​​of a plurality of adjacent columns of the first row ROW1 of the original brightness unevenness compensation data MCD_raw. However, the scope of the present disclosure is not limited thereto.

[0105] Figure 8 It is shown from Figure 6 The graph of the magnitude of the compensation value of the low spatial frequency component extracted from the first row of the original brightness unevenness compensation data is shown in FIG. Figure 8 The horizontal axis in represents the column number of the low spatial frequency component MCD_LF, and the vertical axis represents the magnitude of the compensation value CV.

[0106] refer to Figure 1 and Figures 4 to 8 , compensation values ​​of adjacent column numbers in the first row corresponding to the low spatial frequency component MCD_LF may have similar magnitudes to each other.

[0107] In other words, the compensation values ​​of the low spatial frequency component MCD_LF may be highly correlated with each other. Therefore, the low spatial frequency component MCD_LF may have less compression loss even if it is compressed by a compression algorithm with a higher compression ratio.

[0108] Fig. 9 It is shown Figure 4 A diagram shows the relationship between the original brightness unevenness compensation data MCD_raw, the low spatial frequency component MCD_LF and the high spatial frequency component MCD_HF. Hereinafter, the compensation values ​​arranged in the m-th row and the n-th column of the original brightness unevenness compensation data MCD_raw will be referred to as "CVmnraw". For example, the compensation values ​​arranged in the first row and the second column of the original brightness unevenness compensation data MCD_raw will be referred to as "CV12raw". Similarly, the compensation values ​​arranged in the m-th row and the n-th column of the low spatial frequency component MCD_LF will be referred to as "CVmnLF", and the compensation values ​​arranged in the m-th row and the n-th column of the high spatial frequency component MCD_HF will be referred to as "CVmnHF". However, the scope of the present disclosure is not limited thereto.

[0109] In an embodiment, the spatial frequency component extraction circuit 13 may extract the high spatial frequency component MCD_HF based on the difference between the original brightness unevenness compensation data MCD_raw and the low spatial frequency component MCD_LF. More specifically, the spatial frequency component extraction circuit 13 may determine each of the compensation values ​​of the high spatial frequency component MCD_HF based on the difference between the original brightness unevenness compensation data MCD_raw and the compensation values ​​of the corresponding positions of the low spatial frequency component MCD_LF (i.e., the compensation values ​​having the same row number and column number as each other). For example, the spatial frequency component extraction circuit 13 may determine the compensation value CV11HF of the first row and the first column of the high spatial frequency component MCD_HF based on the difference between the compensation value (i.e., CV11raw) of the first row and the first column of the original brightness unevenness compensation data MCD_raw and the compensation value (i.e., CV11LF) of the first row and the first column of the low spatial frequency component MCD_LF. However, the scope of the present disclosure is not limited thereto, and the spatial frequency component extraction circuit 13 may similarly determine the compensation value arranged in any row and any column of the high spatial frequency component MCD_HF.

[0110] Fig.10 It is shown from Figure 6 The graph of the size (magnitude) of the compensation value of the high spatial frequency component extracted from the first row of the original brightness unevenness compensation data. That is, Fig.10 The horizontal axis in represents the column number of the first row of the high spatial frequency component MCD_HF, and the vertical axis represents the magnitude of the compensation value CV.

[0111] refer to Figure 1 and Figures 4 to 10 , the compensation values ​​in the first row of the high spatial frequency component MCD_HF may have compensation values ​​of inconsistent magnitudes depending on the column number.

[0112] In other words, for example, with respect to the relatively high correlation in the compensation value showing the low spatial frequency component MCD_LF Figure 8 In contrast, each compensation value of the high spatial frequency component MCD_HF may have a (relatively) low correlation with each other. Therefore, the high spatial frequency component MCD_HF will need to be compressed by using a compression algorithm with a relatively low compression ratio to minimize compression losses.

[0113] In an embodiment, each of the compensation values ​​in the high spatial frequency component MCD_HF may have a similar magnitude. For example, ( Fig.10 The difference between the maximum compensation value and the minimum compensation value among the compensation values ​​of the high spatial frequency component MCD_HF shown in FIG. 1 may be less than ( Figure 8The difference between the maximum compensation value and the minimum compensation value among the compensation values ​​of the low spatial frequency component MCD_LF shown in FIG. 1 . In this case, even if the high spatial frequency component MCD_HF is compressed by using a bit width reduction scheme, the compression loss can be minimized. Fig.11 and Fig.12 The specific manner of compressing the high spatial frequency component MCD_HF is described in more detail.

[0114] Fig.11 The embodiment is shown in more detail Figure 4 Now refer to Figure 1 and Figures 4 to 11 The compression circuit #1 14 may include a bit width reduction module BWR and a compression module #1 CM1. The compression circuit #2 15 may include a compression module #2 CM2.

[0115] The bit width reduction module BWR may receive the high spatial frequency component MCD_HF from the spatial frequency component extraction circuit 13. The bit width reduction module BWR may reduce the bit width of the compensation value included in the high spatial frequency component MCD_HF. For example, the bit width reduction module BWR may mask the high-order bits of the compensation value to generate the high spatial frequency component MCD_HF_BWR with reduced bit width. In this case, the code length of the compensation value in the high spatial frequency component MCD_HF_BWR with reduced bit width will be shorter than the code length of the compensation value included in the high spatial frequency component MCD_HF. Fig.12 The specific operation of the bit width reduction module BWR is described in more detail.

[0116] In an embodiment, when the code length of the compensation value included in the high spatial frequency component MCD_HF is "8", the code length of the compensation value in the high spatial frequency component MCD_HF_BWR with reduced bit width may be "5". In this case, the capacity of the high spatial frequency component MCD_HF_BWR with reduced bit width may be about "5 / 8" of the capacity of the high spatial frequency component MCD_HF, and the compression ratio of the bit width reduction module BWR may be referred to as "5 / 8". However, the scope of the present disclosure is not limited thereto.

[0117] The compression module #1CM1 may receive the high spatial frequency component MCD_HF_BWR with a reduced bit width. The compression module #1CM1 may be based on the previous reference Figure 4The first compression algorithm described above is used to compress the high spatial frequency component MCD_HF_BWR with reduced bit width. That is, the compression module #1CM1 can compress the high spatial frequency component MCD_HF_BWR with reduced bit width to generate a compressed high spatial frequency component MCD_HF_comp. In this case, the capacity of the compressed high spatial frequency component MCD_HF_comp can be smaller than the capacity of the high spatial frequency component MCD_HF_BWR with reduced bit width.

[0118] In an embodiment, the first compression algorithm may be multi-level compression MLC.

[0119] In an embodiment, the capacity of the compressed high spatial frequency component MCD_HF_comp may be about "1 / 3" of the capacity of the high spatial frequency component MCD_HF_BWR with reduced bit width. In this case, the compression ratio of the compression module #1CM1 may be referred to as "1 / 3". However, the scope of the present disclosure is not limited thereto.

[0120] In an embodiment, the compression ratio of the compression circuit #1 14 may be determined as the product of the compression ratio of the bit width reduction module BWR and the compression ratio of the compression module #1 CM1. For example, the compression ratio of the compression circuit #1 14 may be determined as "5 / 24", which is the product of "1 / 3" and "5 / 8". However, the scope of the present disclosure is not limited thereto.

[0121] Compression module #2CM2 can receive the low spatial frequency component MCD_LF. Compression module #2CM2 can be based on the previous reference Figure 4 The second compression algorithm described above is used to compress the low spatial frequency component MCD_LF. That is, the compression module #2 CM2 can compress the low spatial frequency component MCD_LF to generate a compressed low spatial frequency component MCD_LF_comp.

[0122] In an embodiment, the compression ratio of the compression circuit #2 15 may be determined based on the compression ratio of the compression module #2 CM2.

[0123] In an embodiment, the compensation values ​​in the low spatial frequency component MCD_LF may have a high correlation with each other. In this case, even if the compression module #2CM2 uses a compression algorithm with a higher compression ratio than the compression module #1CM1, the compression loss may be minimized.

[0124] In an embodiment, the second compression algorithm used by the compression module #2CM2 may be principal component analysis (PCA). However, the scope of the present disclosure is not limited thereto, and the second compression algorithm may be a dimensionality reduction technique such as singular value decomposition (SVD), latent semantic analysis (LSA) and multilevel fuzzy (MF), or may be one of various types of compression algorithms such as noise removal (NR) and 2D image scaling. In this case, the main components of the original brightness unevenness compensation data MCD_raw and the corresponding low spatial frequency components MCD_LF may be effectively compressed.

[0125] In an embodiment, the compression ratio of compression module #2 CM2 may be higher than that of compression module #1 CM1. Further, the compression ratio of compression circuit #2 15 may be higher than that of compression circuit #1 14. For example, compression circuit #2 15 may have a compression ratio of about "1 / 68".

[0126] Fig.12 It is shown Fig.11 FIG. 1 is a diagram of the operation of the bit width reduction module. In the following, reference is made to Figure 1 and Figures 4 to 12 , the operation of the bit width reduction module BWR for some compensation values ​​(e.g., "CV11", "CV12", and "CV13") of the high spatial frequency component MCD_HF will be described. In addition, an embodiment in which the code length of the compensation value of the high spatial frequency component MCD_HF is "8" will be described below. However, the scope of the present disclosure is not limited thereto.

[0127] First, as described above, the high spatial frequency component MCD_HF may be determined based on the difference between the original brightness unevenness compensation data MCD_raw and the low spatial frequency component MCD_LF. Therefore, the deviation of the compensation value in the high spatial frequency component MCD_HF may be smaller than the deviation in the original brightness unevenness compensation data MCD_raw. In this case, the compensation value of the high spatial frequency component MCD_HF may be represented by fewer bits than the compensation value of the original brightness unevenness compensation data MCD_raw.

[0128] For example, "CV11" in the high spatial frequency component MCD_HF may be represented by a binary number "00001111", "CV12" may be represented by a binary number "00001101", and "CV13" may be represented by a binary number "00010001". In other words, the highest-order three bits of the high spatial frequency component MCD_HF may be equal to "000". In the following description, the highest-order three bits of the compensation value of the high spatial frequency component MCD_HF may represent the same bits as each other.

[0129] The bit width reduction module BWR may mask the highest order bits of the compensation value of the high spatial frequency component MCD_HF to generate the high spatial frequency component MCD_HF_BWR with reduced bit width. For example, the bit width reduction module BWR may mask the highest order three bits of the compensation value of the high spatial frequency component MCD_HF.

[0130] For example, when the highest-order three bits of "CV11" of the high spatial frequency component MCD_HF are masked, the binary number "01111" may become "CV11" of the high spatial frequency component MCD_HF_BWR with reduced bit width. Similarly, "CV12" in the high spatial frequency component MCD_HF_BWR with reduced bit width may be the binary number "01101", and "CV13" may be the binary number "10001". In this case, the display driving circuit 100 may be able to easily restore the high spatial frequency component MCD_HF from the high spatial frequency component MCD_HF_BWR with reduced bit width (e.g., by adding back the highest-order bits).

[0131] In other words, according to an embodiment of the present disclosure, even if the bit width reducing module BWR masks the highest order bit of the compensation value of the high spatial frequency component MCD_HF, the compensation value of the high spatial frequency component MCD_HF may be restored without loss.

[0132] exist Fig.12 , the highest-order three bits of the compensation value of the high spatial frequency component MCD_HF are identical to each other. However, the scope of the present disclosure is not limited to this, and the compensation value of the high spatial frequency component MCD_HF may be the same in the highest-order "N" bits. In this case, the bit width reduction module BWR may be implemented to mask the highest-order "N" bits of the compensation value of the high spatial frequency component MCD_HF. In other words, the scope of the present disclosure is not limited to the number of bits masked by the bit width reduction module BWR.

[0133] Fig.13 is a table showing the compression ratio of the uneven brightness compensation data MCD according to an embodiment of the present disclosure. Figure 2 Describes the compression ratio of the original brightness unevenness compensation data MCD_raw, and refers to Figures 4 to 12Describes the compression ratio when classified according to spatial frequency components.

[0134] First, refer to Figure 1 , Figure 2 and Fig.13 , the compression circuit 1c may compress the original uneven brightness compensation data MCD_raw to generate compressed uneven brightness compensation data MCD_comp. In a more detailed example, the compression circuit 1c may compress the original uneven brightness compensation data MCD_raw using an MLC compression algorithm. In other words, since the original uneven brightness compensation data MCD_raw includes a high spatial frequency component, the compression circuit 1c may compress the original uneven brightness compensation data MCD_raw by using a compression algorithm with a relatively low compression ratio (e.g., 1 / 3) to minimize compression loss.

[0135] That is to say, according to Figure 2 In an embodiment, the compressed uneven brightness compensation data MCD_comp of about one third of the capacity of the original uneven brightness compensation data MCD_raw may be stored in the storage circuit 120. In this case, the capacity of the uneven brightness compensation data stored in the storage circuit 120 may be about 33% of the capacity of the original uneven brightness compensation data.

[0136] On the other hand, reference Figure 1 and Figures 4 to 13 , the high spatial frequency component MCD_HF can be compressed using bit width reduction and MLC compression algorithm.

[0137] In a more detailed example, the compression circuit #1 14 can reduce the bit width of the high spatial frequency component MCD_HF via the bit width reduction module BWR to generate a high spatial frequency component MCD_HF_BWR with reduced bit width. In this case, the capacity of the high spatial frequency component MCD_HF_BWR with reduced bit width can be about 5 / 8 of the high spatial frequency component MCD_HF.

[0138] Next, the compression circuit #1 14 may compress the reduced-bitwidth high spatial frequency component MCD_HF_BWR through the compression module #1 CM1 to generate a compressed high spatial frequency component MCD_HF_comp. In this case, the capacity of the compressed high spatial frequency component MCD_HF_comp may be about 1 / 3 of the capacity of the reduced-bitwidth high spatial frequency component MCD_HF_BWR.

[0139] Therefore, the capacity of the compressed high spatial frequency component MCD_HF_comp may be approximately 5 / 24 (=5 / 8*1 / 3) of the capacity of the high spatial frequency component MCD_HF. In this case, the capacity of the high spatial frequency component MCD_HF may be equal to the capacity of the original brightness unevenness compensation data MCD_raw, and thus the capacity of the compressed high spatial frequency component MCD_HF_comp may be approximately 5 / 24 of the capacity of the original brightness unevenness compensation data MCD_raw.

[0140] The low spatial frequency component MCD_LF can be compressed using a PCA compression algorithm. For example, the compression circuit #2 15 can compress the low spatial frequency component MCD_LF through the compression module #2CM2 to generate a compressed low spatial frequency component MCD_LF_comp. In this case, the capacity of the compressed low spatial frequency component MCD_LF_comp can be about 1 / 68 of the low spatial frequency component MCD_LF. Therefore, the capacity of the compressed low spatial frequency component MCD_LF_comp can be about 1 / 68 of the capacity of the original brightness unevenness compensation data MCD_raw.

[0141] That is, according to an embodiment of the present disclosure, the compressed high spatial frequency component MCD_HF_comp having about 5 / 24 of the capacity of the original brightness unevenness compensation data MCD_raw and the compressed low spatial frequency component MCD_LF_comp having about 1 / 68 of the capacity of the original brightness unevenness compensation data MCD_raw may be stored in the storage circuit 120. In this case, the capacity of the brightness unevenness compensation data stored in the storage circuit 120 may be about 22% of the capacity of the original brightness unevenness compensation data. Therefore, according to an embodiment of the present disclosure, the capacity of the brightness unevenness compensation data stored in the storage circuit 120 for the brightness unevenness compensation operation may be minimized.

[0142] Fig.14 It is shown Figure 4 Flow chart of the operation of the device for generating uneven brightness compensation data. Figure 1 and Figures 4 to 14 In operation S110, the uneven brightness compensation data generating device 10 may generate optical information of the controlled display panel DP based on the test data DATA_test. For example, the optical measurement circuit 11 may generate optical information OPI representing an image output through the display panel DP.

[0143] In operation S120, the uneven brightness compensation data generating device 10 may generate raw uneven brightness compensation data MCD_raw based on the optical information OPI. For example, the compensation data generating circuit 12 may determine the brightness level that needs to be compensated for each of the pixels of the display panel DP to generate raw uneven brightness compensation data MCD_raw. In this case, the raw uneven brightness compensation data MCD_raw may represent the brightness level determined to be compensated for each pixel of the display panel DP.

[0144] In operation S130, the brightness unevenness compensation data generating device 10 may extract the high spatial frequency component MCD_HF and the low spatial frequency component MCD_LF from the original brightness unevenness compensation data MCD_raw. For example, the spatial frequency component extraction circuit 13 may extract the high spatial frequency component MCD_HF and the low spatial frequency component MCD_LF from the original brightness unevenness compensation data MCD_raw. Fig.15 The operation of operation S130 is described in more detail.

[0145] In operation S140, the brightness unevenness compensation data generating device 10 may compress the high spatial frequency component MCD_HF and the low spatial frequency component MCD_LF based on different compression algorithms. For example, the compression circuit #1 14 may compress the high spatial frequency component MCD_HF by using bit width reduction and a first compression algorithm, and the compression circuit #2 15 may compress the low spatial frequency component MCD_LF by using a second compression algorithm. Fig.11 The operations of the compression circuit #1 14 and the compression circuit #2 15 are described, and thus a detailed description thereof will be omitted.

[0146] In an embodiment, the luminance unevenness compensation data generating apparatus 10 may compress the high spatial frequency component MCD_HF and the low spatial frequency component MCD_LF sequentially or simultaneously. In other words, the scope of the present disclosure is not limited to the operation sequence of the compression circuit #1 14 and the compression circuit #2 15.

[0147] In operation S150, the luminance unevenness compensation data generating device 10 may store the compressed high spatial frequency component MCD_HF_comp and the compressed low spatial frequency component MCD_LF_comp in the storage circuit 120. For example, the compression circuit #1 14 may store the compressed high spatial frequency component MCD_HF_comp in the storage circuit 120, and the compression circuit #2 15 may store the compressed low spatial frequency component MCD_LF_comp in the storage circuit 120.

[0148] In an embodiment, the storage circuit 120 may be included in the display driving circuit 100 . However, the scope of the present disclosure is not limited thereto, and the storage circuit 120 may exist outside the display driving circuit 100 .

[0149] Fig.15 is shown in more detail Fig.14 Flow chart of operation S130.

[0150] refer to Figure 1 and Figures 4 to 15 , operation S130 may include the following operations S131 and S132.

[0151] In operation S131 , the spatial frequency component extraction circuit 13 may provide the raw uneven brightness compensation data MCD_raw to a spatial frequency low pass filter to extract a low spatial frequency component MCD_LF from the raw uneven brightness compensation data MCD_raw.

[0152] In operation S132 , the spatial frequency component extraction circuit 13 may extract the high spatial frequency component MCD_HF based on the difference between the raw uneven brightness compensation data MCD_raw and the low spatial frequency component MCD_LF.

[0153] Fig.16 The present invention is a diagram showing an embodiment of the present invention. Figure 1 A block diagram of the operation of the display driving circuit 100 is shown in FIG. Figure 1 and Figures 4 to 16 , the storage circuit 120 may store the compressed high spatial frequency component MCD_HF_comp and the compressed low spatial frequency component MCD_LF_comp.

[0154] The brightness unevenness compensator 110 may receive the compressed high spatial frequency component MCD_HF_comp and the compressed low spatial frequency component MCD_LF_comp from the storage circuit 120 to perform a brightness unevenness compensation operation on the input video data VDT_in. For example, the brightness unevenness compensator 110 may include a decompression circuit #1 111, a decompression circuit #2 112, a brightness unevenness compensation data (MCD) merging circuit 113, and a brightness unevenness compensation circuit 114.

[0155] The decompression circuit #1 111 may receive the compressed high spatial frequency component MCD_HF_comp from the storage circuit 120. For example, the decompression circuit #1 111 may decompress the compressed high spatial frequency component MCD_HF_comp based on a first compression algorithm.

[0156] For example, the decompression circuit #1 111 may sequentially perform the previously referenced Fig.11The decompression circuit #1 111 may perform the inverse operation of the compression module #1 CM1 and the bit width reduction module BWR described above. That is, the decompression circuit #1 111 may perform the inverse operation of the compression module #1 CM1 on the compressed high spatial frequency component MCD_HF_comp to generate the high spatial frequency component MCD_HF_BWR with reduced bit width. The decompression circuit #1 111 may then perform the inverse operation of the bit width reduction module BWR on the high spatial frequency component MCD_HF_BWR with reduced bit width to generate the restored high spatial frequency component MCD_HF_restore.

[0157] Similarly, the decompression circuit #2 112 may receive the compressed low spatial frequency component MCD_LF_comp from the storage circuit 120. The decompression circuit #2 112 may decompress the compressed high spatial frequency component MCD_HF_comp based on a second compression algorithm.

[0158] For example, decompression circuit #2 112 may perform the previously referenced Fig.11 That is, the decompression circuit #2 112 may perform the inverse operation of the compression module #2 CM2 on the compressed low spatial frequency component MCD_LF_comp to generate the restored low spatial frequency component MCD_LF_restore.

[0159] The MCD merging circuit 113 may merge the restored high spatial frequency component MCD_HF_restore and the restored low spatial frequency component MCD_LF_restore to generate restored raw uneven brightness compensation data MCD_raw_restore. In this case, the restored raw uneven brightness compensation data MCD_raw_restore may correspond to the previously referenced Figure 4 Described is the raw brightness unevenness compensation data MCD_raw.

[0160] In an embodiment, the MCD merging circuit 113 may perform a summing operation on the restored high spatial frequency component MCD_HF_restore and the restored low spatial frequency component MCD_LF_restore to generate restored original uneven brightness compensation data MCD_raw_restore. In this case, each of the compensation values ​​included in the restored original uneven brightness compensation data MCD_raw_restore may be determined by the sum of the compensation values ​​arranged at the corresponding positions of the restored high spatial frequency component MCD_HF_restore and the restored low spatial frequency component MCD_LF_restore. However, the scope of the present disclosure is not limited thereto.

[0161] In an embodiment, the MCD merging circuit 113 may perform a weighted sum operation on the restored high spatial frequency component MCD_HF_restore and the restored low spatial frequency component MCD_LF_restore to generate restored original uneven brightness compensation data MCD_raw_restore. In this case, each of the compensation values ​​included in the restored original uneven brightness compensation data MCD_raw_restore may be determined by the weighted sum of the compensation values ​​arranged at the corresponding positions of the restored high spatial frequency component MCD_HF_restore and the restored low spatial frequency component MCD_LF_restore. However, the scope of the present disclosure is not limited thereto.

[0162] That is, according to an embodiment of the present disclosure, the restored original brightness unevenness compensation data MCD_raw_restore corresponding to the original brightness unevenness compensation data MCD_raw may be generated according to the compressed high spatial frequency component MCD_HF_comp and the compressed low spatial frequency component MCD_LF_comp. Therefore, according to an embodiment of the present disclosure, the capacity of the brightness unevenness compensation data stored in the storage circuit 120 for the brightness unevenness compensation operation may be minimized.

[0163] In an embodiment, the brightness unevenness compensation data generated by the MCD combining circuit 113 (ie, the restored original brightness unevenness compensation data) may also be referred to as combined brightness unevenness compensation data. The combined brightness unevenness compensation data may be used for the brightness unevenness compensation operation of the display panel DP.

[0164] The uneven brightness compensation circuit 114 may receive the restored original uneven brightness compensation data MCD_raw_restore from the MCD merging circuit 113. The uneven brightness compensation circuit 114 may perform an uneven brightness compensation operation on the input video data VDT_in based on the restored original uneven brightness compensation data MCD_raw_restore. For example, the uneven brightness compensation circuit 114 may compensate for the brightness information of each pixel on the display panel DP represented by the input video data VDT_in using the compensation value arranged at the corresponding position in the restored original uneven brightness compensation data MCD_raw_restore to generate the output video data VDT_out.

[0165] In a more detailed example, the luminance information of the pixels arranged in the first row and the first column of the display panel DP represented by the output video data VDT_out can be determined by the luminance information of the pixels arranged in the first row and the first column of the display panel DP represented by the input video data VDT_in, and the sum of the compensation values ​​CV11 arranged in the first row and the first column of the restored original luminance unevenness compensation data MCD_raw_restore. However, the scope of the present disclosure is not limited to a specific manner in which the luminance unevenness compensation circuit 114 generates the output video data VDT_out. For example, the luminance unevenness compensation circuit 114 can generate the output video data VDT_out by weighted summing of the compensation values ​​arranged at corresponding positions of the input video data VDT_in and the restored original luminance unevenness compensation data MCD_raw_restore. In this case, the brightness information of the pixels arranged in the first row and the first column of the display panel DP represented by the output video data VDT_out can be determined by the weighted summation of the brightness information of the pixels arranged in the first row and the first column of the display panel DP represented by the input video data VDT_in, and the compensation value CV11 arranged in the first row and the first column of the restored original brightness unevenness compensation data MCD_raw_restore.

[0166] In an embodiment, according to an embodiment of the present disclosure, even if each of the pixels of the display panel DP represents the same brightness as each other, the magnitude of the signal provided to the display panel DP through the data line by the source driver 150 in response to the output video data VDT_out may be different.

[0167] Fig.17 It is shown Fig.16 Flow chart of the operation of the display driving circuit 100. Figure 1 and Figures 4 to 17 In operation S210, the display driving circuit 100 may decompress the compressed high spatial frequency component MCD_HF_comp and the compressed low spatial frequency component MCD_LF_comp. For example, the decompression circuit #1 111 may decompress the compressed high spatial frequency component MCD_HF_comp to generate a restored high spatial frequency component MCD_HF_restore. And, the decompression circuit #2 112 may decompress the compressed low spatial frequency component MCD_LF_comp to generate a restored low spatial frequency component MCD_LF_restore.

[0168] In an embodiment, the display driving circuit 100 may sequentially or simultaneously decompress the compressed high spatial frequency component MCD_HF_comp and the compressed low spatial frequency component MCD_LF_comp. In other words, the scope of the present disclosure is not limited to the operation sequence of the decompression circuit #1 111 and the decompression circuit #2 112.

[0169] In operation S220, the display driving circuit 100 may merge the restored high spatial frequency component MCD_HF_restore and the restored low spatial frequency component MCD_LF_restore to generate restored original uneven brightness compensation data MCD_raw_restore. For example, the MCD merging circuit 113 may perform a summing operation or a weighted summing operation on the restored high spatial frequency component MCD_HF_restore and the restored low spatial frequency component MCD_LF_restore to generate restored original uneven brightness compensation data MCD_raw_restore. In this case, the restored original uneven brightness compensation data MCD_raw_restore may correspond to the previously referenced Figure 4 Described is the raw brightness unevenness compensation data MCD_raw.

[0170] In operation S230, the display driving circuit 100 may perform a brightness unevenness compensation operation on the input video data VDT_in based on the restored original brightness unevenness compensation data MCD_raw_restore to generate output video data VDT_out. For example, the brightness unevenness compensation circuit 114 may compensate for the brightness information of each pixel on the display panel DP represented by the input video data VDT_in using the compensation value arranged at the corresponding position in the restored original brightness unevenness compensation data MCD_raw_restore to generate output video data VDT_out.

[0171] In operation S240, the display driving circuit 100 may provide the output video data VDT_out to the display panel DP. For example, the display driving circuit 100 may provide the output video data VDT_out to the display panel DP through the source driver 150. In this case, when the user views the display panel DP, the uneven brightness may not be observed.

[0172] Fig.18 It is shown that the Figure 4 A block diagram of the spatial frequency component extraction circuit 12 is shown. Figure 1 , Figure 4 and Fig.18, the spatial frequency component extraction circuit 13_2 may include a spatial frequency low-pass filter LPF_SF, a compression circuit #3CC, a decompression circuit #3DCC, and a differential circuit DFC. The operation of the spatial frequency low-pass filter LPF_SF is similar to that of the previous reference. Figure 5 The operations described are omitted here and therefore their detailed description is omitted.

[0173] The compression circuit #3CC may receive and compress the low spatial frequency component MCD_LF. That is, the compression circuit #3CC may generate a compressed low spatial frequency component MCD_LF_comp.

[0174] In an embodiment, compression circuit #3CC may be configured similarly to the previously described Figure 4 However, the scope of the present disclosure is not limited thereto, and the compression circuit #3CC and the compression circuit #2 15 may be implemented as a single component.

[0175] The decompression circuit #3 DCC may decompress the compressed low spatial frequency component MCD_LF_comp' to generate the compressed and decompressed low spatial frequency component MCD_LF'. In other words, the compressed and decompressed low spatial frequency component MCD_LF' may refer to the result of compressing and then decompressing the low spatial frequency component MCD_LF.

[0176] In an embodiment, the decompression circuit #3DCC may be similar to the previously referenced Fig.15 However, the scope of the present disclosure is not limited thereto, and the decompression circuit #3 DCC and the decompression circuit #2 112 may be implemented as a single component.

[0177] The differential circuit DFC may receive the original uneven brightness compensation data MCD_raw and the compressed and decompressed low spatial frequency component MCD_LF'. The differential circuit DFC may extract the high spatial frequency component MCD_HF based on the difference between the original uneven brightness compensation data MCD_raw and the compressed and decompressed low spatial frequency component MCD_LF'.

[0178] In an embodiment, the compressed and decompressed low spatial frequency component MCD_LF' may reflect an error that may be caused by compressing and then decompressing the low spatial frequency component MCD_LF. In this case, the high spatial frequency component MCD_HF and the compressed high spatial frequency component MCD_HF_comp may reflect an error that may be caused by compressing and then decompressing the low spatial frequency component MCD_LF. Therefore, according to an embodiment of the present disclosure, the difference between the restored original uneven brightness compensation data MCD_raw_restore and the original uneven brightness compensation data MCD_raw can be minimized.

[0179] Fig.19 is a diagram showing a method for generating a Figure 1 Block diagram of a brightness unevenness compensation system for brightness unevenness compensation data. Figure 1 , Figure 4 and Fig.19 The brightness unevenness compensation system MCS may include a display panel DP, a display driving circuit 200 and a brightness unevenness compensation data generating device 20. The functions and operations of the display panel DP and the display driving circuit 200 are similar to those of the previous reference Figure 1 and Figure 4 The functions and operations of the display driving circuit 100 are described, and thus a detailed description thereof is omitted.

[0180] The uneven brightness compensation data generating device 20 may include an optical measuring circuit 21 , a spatial frequency component extracting circuit 22 , a compensation data generating circuit # 1 23 , a compensation data generating circuit # 2 24 , a compression circuit # 1 25 , and a compression circuit # 2 26 .

[0181] The optical measurement circuit 21 may generate optical information OPI representing an image output through the display panel DP. The optical information OPI may include a plurality of brightness values ​​for each of the pixels of the display panel DP. For example, the optical information OPI may include a plurality of brightness values ​​measured for each pixel of the display panel DP. More specifically, the optical information OPI may be implemented as a plurality of brightness values ​​arranged in a row direction and a column direction. Fig. 20 The relationship between the optical information OPI and the pixels of the display panel DP is described in more detail.

[0182] The spatial frequency component extraction circuit 22 can extract the high spatial frequency component OPI_HF of the optical information and the low spatial frequency component OPI_LF of the optical information from the optical information OPI. Figure 4 In the described embodiment, the spatial frequency component extraction circuit 22 can extract the high spatial frequency component and the low spatial frequency component from the optical information OPI.

[0183] In an embodiment, the spatial frequency component extraction circuit 22 may include a spatial frequency low-pass filter. In this case, the spatial frequency component extraction circuit 22 may be able to extract the low spatial frequency component OPI_LF of the optical information from the optical information OPI through the spatial frequency low-pass filter. Subsequently, the spatial frequency component extraction circuit 22 may extract the high spatial frequency component OPI_HF of the optical information based on the difference between the optical information OPI and the low spatial frequency component OPI_LF of the optical information. The detailed operation of the spatial frequency component extraction circuit 22 is similar to that of the previous reference. Figures 4 to 10 The operations described are simple and thus their detailed description will be omitted.

[0184] In an embodiment, the capacity of the high spatial frequency component OPI_HF of the optical information and the capacity of the low spatial frequency component OPI_LF of the optical information may be the same. More specifically, the number of brightness values ​​arranged in the row direction and column direction of the high spatial frequency component OPI_HF of the optical information and the low spatial frequency component OPI_LF of the optical information may be equal to the optical information OPI.

[0185] The compensation data generating circuit #1 23 may generate the first uneven brightness compensation data MCDa based on the high spatial frequency component OPI_HF of the optical information. That is, the compensation data generating circuit #1 23 may determine the brightness level to be compensated for each of the pixels of the display panel DP based on the high spatial frequency component OPI_HF of the optical information.

[0186] The compensation data generating circuit #2 24 may generate the second uneven brightness compensation data MCDb based on the low spatial frequency component OPI_LF of the optical information. That is, the compensation data generating circuit #2 24 may determine the brightness level to be compensated for each of the pixels of the display panel DP based on the low spatial frequency component OPI_LF of the optical information.

[0187] The compression circuit #1 25 may compress the first uneven brightness compensation data MCDa to generate first compressed uneven brightness compensation data MCDa_comp. For example, the compression circuit #1 25 may compress the first uneven brightness compensation data MCDa_comp based on the previous reference. Figure 4 The first compression algorithm is described to compress the first uneven brightness compensation data MCDa.

[0188] In an embodiment, compression circuit #1 25 may be configured similarly to the previously described Fig.11 For example, the compression circuit #1 25 may perform a bit width reduction operation on the compensation value of the first brightness unevenness compensation data MCDa, and then perform a compression operation using the first compression algorithm described above. In this case, the configuration and operation of the compression circuit #1 25 are the same as those described previously with reference to FIG. Fig.11 The configuration and operation described are similar, so a detailed description thereof will be omitted.

[0189] The compression circuit #2 26 may compress the second uneven brightness compensation data MCDb to generate second compressed uneven brightness compensation data MCDb_comp. For example, the compression circuit #2 26 may compress the second uneven brightness compensation data MCDb to generate second compressed uneven brightness compensation data MCDb_comp based on the previous reference. Figure 4 The second compression algorithm described above is used to compress the second brightness unevenness compensation data MCDb. In other words, the compression circuit #2 26 may perform a compression operation by using a compression algorithm having a higher compression ratio than the compression circuit #1 25. In this case, the size (capacity) of the second compressed brightness unevenness compensation data MCDb_comp may be smaller than the first compressed brightness unevenness compensation data MCDa_comp.

[0190] In an embodiment, compression circuit #2 26 may be configured similarly to the previously described Fig.11 For example, the compression circuit #2 26 may perform a compression operation on the second brightness unevenness compensation data MCDb using the second compression algorithm described above. In this case, the configuration and operation of the compression circuit #2 26 are the same as those described previously with reference to FIG. Fig.11 The configuration and operation described are similar, so a detailed description thereof will be omitted.

[0191] The compression circuit #1 25 may store the first compressed brightness unevenness compensation data MCDa_comp in the storage circuit 220. The compression circuit #2 26 may store the second compressed brightness unevenness compensation data MCDb_comp in the storage circuit 220. In this way, the storage circuit 220 may store the first compressed brightness unevenness compensation data MCDa_comp and the second compressed brightness unevenness compensation data MCDb_comp. In this case, the sum of the capacity of the first compressed brightness unevenness compensation data MCDa_comp and the second compressed brightness unevenness compensation data MCDb_comp may be less than the above reference. Figure 2 Therefore, according to an embodiment of the present disclosure, the capacity of the storage circuit 220 can be minimized.

[0192] Fig. 20 It is shown Fig.19 Schematic diagram of optical information OPI. Figure 1 as well as Fig.19 and Fig. 20, the optical information OPI may include a plurality of brightness values ​​LV. In the following description, the plurality of brightness values ​​LV may be arranged in the row direction and the column direction. Further, the brightness value arranged at the mth row and the nth column of the optical information OPI among the plurality of brightness values ​​LV will be referred to as "LVmn". For example, the brightness value arranged at the first row and the second column of the optical information OPI may be referred to as "LV12". However, the scope of the present disclosure is not limited thereto.

[0193] Each of the plurality of brightness values ​​LV may represent a brightness value of one of the pixels of the display panel DP. An embodiment will be described below in which the optical measurement circuit 21 generates a 3×3 arrangement of brightness values ​​for each of the pixels of the display panel DP. However, the scope of the present disclosure is not limited thereto. For example, the optical measurement circuit 21 may generate any number of brightness values ​​for each of the pixels of the display panel DP.

[0194] "LV11" to "LV13", "LV21" to "LV23" and "LV31" to "LV33" may represent the brightness values ​​of the pixel PX11 arranged at the first column of the first row of the display panel DP, and "LV14" to "LV16", "LV24" to "LV26" and "LV34" to "LV36" may represent the brightness values ​​of the pixel PX12 arranged at the second column of the first row of the display panel DP.

[0195] In an embodiment, the optical measurement circuit 21 may be implemented as an image sensor device for photographing the display panel DP. In this case, the brightness value measured for one pixel of the display panel DP may be measured by different image pixels of the image sensor device. For example, "LV11" to "LV13", "LV21" to "LV23", and "LV31" to "LV33" may be measured by nine different image pixels. However, the scope of the present disclosure is not limited thereto.

[0196] The spatial frequency component extraction circuit 22 may extract high spatial frequency components and low spatial frequency components for each row of the optical information OPI. For example, the spatial frequency component extraction circuit 22 may extract high spatial frequency components and low spatial frequency components for the first row of the optical information OPI based on the magnitude of the brightness value according to the column number of the first row of the optical information OPI. However, the scope of the present disclosure is not limited thereto, and the spatial frequency component extraction circuit 22 may extract high spatial frequency components and low spatial frequency components for each column of the optical information OPI.

[0197] In the following, reference FIG. 21A to FIG. 21CAn embodiment is described in which the spatial frequency component extraction circuit 22 extracts high spatial frequency components and low spatial frequency components for the first row of the optical information OPI. However, the scope of the present disclosure is not limited thereto, and the spatial frequency component extraction circuit 22 can extract high spatial frequency components and low spatial frequency components in a similar manner for any row or column of the optical information OPI.

[0198] FIG. 21A to FIG. 21C It is shown separately Fig. 20 The optical information, the low spatial frequency component of the optical information and the high spatial frequency component of the optical information are shown in FIG. FIG. 21A to FIG. 21C , the horizontal axis represents the column number, and the vertical axis represents the magnitude of the brightness value LV.

[0199] first, Fig.21A is a graph showing brightness values ​​according to column numbers in the first row of optical information OPI. Figure 1 , Figure 19 to Figure 20 as well as Fig.21A , the first row of the optical information OPI may store brightness values ​​that are non-constant values ​​according to the column number.

[0200] The spatial frequency component extraction circuit 22 may extract a low spatial frequency component with respect to the first line of the optical information OPI through a spatial frequency low-pass filter.

[0201] In an embodiment, the high spatial frequency component of the optical information OPI may refer to a component having a large change in the magnitude of the brightness value based on the column number. On the other hand, the low spatial frequency component of the optical information OPI may refer to a component having a small change in the magnitude of the brightness value based on the column number. Therefore, the high spatial frequency component and the low spatial frequency component of the optical information OPI may be determined based on the magnitude of the plurality of brightness values ​​and the arrangement of the plurality of brightness values.

[0202] Fig. 21B It is shown that according to Fig.21A The first row of the optical information OPI extracts the brightness value of the low spatial frequency component OPI_LF in the first row of the optical information. Figure 1 and Figures 19 to 21B , the brightness values ​​of adjacent column numbers in the first row corresponding to the low spatial frequency component OPI_LF of the optical information may have similar magnitudes to each other. This means that the brightness values ​​of the low spatial frequency component OPI_LF of the optical information may have high correlation to each other.

[0203] Fig. 21C It is shown that according to Fig.21A The first row of the optical information OPI is a graph of the brightness values ​​of the column numbers in the first row of the high spatial frequency component OPI_HF of the optical information extracted. Figure 1 and Figures 19 to 21C, the brightness values ​​in the first row of the high spatial frequency component OPI_HF of the optical information may have a non-constant magnitude depending on the column number. In other words, the brightness values ​​of the high spatial frequency component OPI_HF of the optical information may have a low correlation with each other.

[0204] In an embodiment, the high spatial frequency component OPI_HF of the optical information can be extracted based on the difference between the optical information OPI and the low spatial frequency component OPI_LF of the optical information. The specific manner of extracting the high spatial frequency component OPI_HF of the optical information is similar to that described in the previous reference. Fig. 9 The method of extracting the high spatial frequency component MCD_HF is described, and thus a detailed description thereof will be omitted.

[0205] Fig. 22 It is shown Fig.19 Flow chart of the operation of the device for generating uneven brightness compensation data. Figure 1 and Figures 19 to 22 In operation S310, the uneven brightness compensation data generating device 20 may generate optical information of the controlled display panel DP based on the test data DATA_test. For example, the optical measurement circuit 21 may generate optical information OPI representing an image output through the display panel DP.

[0206] In operation S320, the uneven brightness compensation data generating device 20 may extract high spatial frequency components OPI_HF and low spatial frequency components OPI_LF of optical information from the optical information OPI. For example, the spatial frequency component extracting circuit 22 may extract high spatial frequency components OPI_HF and low spatial frequency components OPI_LF of optical information from the optical information OPI.

[0207] In operation S330, the uneven brightness compensation data generating device 20 may extract the first uneven brightness compensation data MCDa from the high spatial frequency component OPI_HF of the optical information, and extract the second uneven brightness compensation data MCDb from the low spatial frequency component OPI_LF of the optical information. For example, the compensation data generating circuit #1 23 may generate the first uneven brightness compensation data MCDa based on the high spatial frequency component OPI_HF of the optical information, and the compensation data generating circuit #2 24 may generate the second uneven brightness compensation data MCDb based on the low spatial frequency component OPI_LF of the optical information.

[0208] In operation S340 , the uneven brightness compensation data generating apparatus 20 may compress the first uneven brightness compensation data MCDa and the second uneven brightness compensation data MCDb based on different compression algorithms.

[0209] For example, the compression circuit #1 25 may compress the first uneven brightness compensation data MCDa to generate first compressed uneven brightness compensation data MCDa_comp. In this case, the compression circuit #1 25 may compress the first uneven brightness compensation data MCDa based on a first compression algorithm.

[0210] On the other hand, the compression circuit #2 26 may compress the second uneven brightness compensation data MCDb to generate second compressed uneven brightness compensation data MCDb_comp. In this case, the compression circuit #2 26 may compress the second uneven brightness compensation data MCDb based on a second compression algorithm.

[0211] In an embodiment, the luminance unevenness compensation data generating device 20 may compress the first luminance unevenness compensation data MCDa and the second luminance unevenness compensation data MCDb sequentially or simultaneously. In other words, the scope of the present disclosure is not limited to the operation sequence of the compression circuit #1 25 and the compression circuit #2 26.

[0212] In operation S350, the luminance unevenness compensation data generating device 20 may store the first compressed luminance unevenness compensation data MCDa_comp and the second compressed luminance unevenness compensation data MCDb_comp in the storage circuit 220. For example, the compression circuit #1 25 may store the first compressed luminance unevenness compensation data MCDa_comp in the storage circuit 220. The compression circuit #2 26 may store the second compressed luminance unevenness compensation data MCDb_comp in the storage circuit 220.

[0213] Fig.23 Another embodiment of the present disclosure is shown in FIG. Figure 1 A flow chart of the operation of the display driver circuit. Figure 1 and Figures 19 to 23 , the storage circuit 220 may store the first compressed uneven brightness compensation data MCDa_comp and the second compressed uneven brightness compensation data MCDb_comp.

[0214] The uneven brightness compensation circuit 210 may receive the first compressed uneven brightness compensation data MCDa_comp and the second compressed uneven brightness compensation data MCDb_comp from the storage circuit 220, and perform an uneven brightness compensation operation on the input video data VDT_in. For example, the uneven brightness compensation circuit 210 may include a decompression circuit #1 211, a decompression circuit #2 212, an uneven brightness compensation data merging circuit 213, and an uneven brightness compensation circuit 214.

[0215] The decompression circuit #1 211 may receive the first compressed uneven brightness compensation data MCDa_comp from the storage circuit 220, and decompress the received first compressed uneven brightness compensation data MCDa_comp. For example, the decompression circuit #1 211 may generate restored first uneven brightness compensation data MCDa_restore according to the first compressed uneven brightness compensation data MCDa_comp based on a first compression algorithm. For example, the decompression circuit #1 211 may generate restored first uneven brightness compensation data MCDa_restore according to the first compressed uneven brightness compensation data MCDa_comp in a manner similar to that previously described with reference to FIG. Fig.16 Decompression circuit #1 111 operates in the manner described.

[0216] The decompression circuit #2 212 may receive the second compressed uneven brightness compensation data MCDb_comp from the storage circuit 220, and decompress the received second compressed uneven brightness compensation data MCDb_comp. The decompression circuit #2 212 may generate restored second uneven brightness compensation data MCDb_restore from the second compressed uneven brightness compensation data MCDb_comp based on a second compression algorithm. For example, the decompression circuit #2 212 may generate restored second uneven brightness compensation data MCDb_restore in a manner similar to that described previously with reference to FIG. Fig.16 Decompression circuit #2 112 operates in the manner described.

[0217] The uneven brightness compensation data merging circuit 213 may merge the restored first uneven brightness compensation data MCDa_restore and the restored second uneven brightness compensation data MCDb_restore to generate reference uneven brightness compensation data MCD_ref.

[0218] In an embodiment, the uneven brightness compensation data (ie, reference uneven brightness compensation data) generated by the uneven brightness compensation data combining circuit 213 may also be referred to as combined uneven brightness compensation data. The combined uneven brightness compensation data may be used for the uneven brightness compensation operation of the display panel DP.

[0219] The brightness unevenness compensation circuit 214 can perform a brightness unevenness compensation operation on the input video data VDT_in based on the reference brightness unevenness compensation data MCD_ref. For example, the brightness unevenness compensation circuit 214 can compensate the brightness information of each pixel on the display panel DP represented by the input video data VDT_in using the compensation value arranged at the corresponding position in the reference brightness unevenness compensation data MCD_ref to generate the output video data VDT_out. The operation of the brightness unevenness compensation data merging circuit 213 and the brightness unevenness compensation circuit 214 is similar to the above reference brightness unevenness compensation data. Fig.16 The operations described are simple and thus their detailed description will be omitted.

[0220] Fig.24 It is shown Fig.23A flow chart of the operation of the display driver circuit. Figure 1 and Figures 19 to 23 In operation S410, the display driving circuit 200 may decompress the first compressed uneven brightness compensation data MCDa_comp and the second compressed uneven brightness compensation data MCDb_comp. For example, the decompression circuit #1 211 may generate restored first uneven brightness compensation data MCDa_restore from the first compressed uneven brightness compensation data MCDa_comp based on a first compression algorithm, and the decompression circuit #2 212 may generate restored second uneven brightness compensation data MCDb_restore from the second compressed uneven brightness compensation data MCDb_comp based on a second compression algorithm.

[0221] In operation S420, the display driving circuit 200 may merge the restored first uneven brightness compensation data MCDa_restore and the restored second uneven brightness compensation data MCDb_restore to generate reference uneven brightness compensation data MCD_ref. For example, the uneven brightness compensation data merging circuit 213 may merge the restored first uneven brightness compensation data MCDa_restore and the restored second uneven brightness compensation data MCDb_restore to generate reference uneven brightness compensation data MCD_ref.

[0222] In operation S430, the display driving circuit 200 may perform a brightness unevenness compensation operation on the input video data VDT_in based on the reference brightness unevenness compensation data MCD_ref to generate output video data VDT_out. In operation S440, the display driving circuit 200 may provide the output video data VDT_out to the display panel DP. Because the operation of the display driving circuit 200 in operations S430 and S440 is similar to Fig.17 The operations in operations S230 and S240 are described in detail, so a detailed description thereof will be omitted.

[0223] The above are specific embodiments for implementing the present disclosure. The present disclosure may include not only the above embodiments, but also embodiments that are simply redesigned or can be easily modified. The present disclosure will also include techniques that can be easily modified and practiced by using the embodiments. Therefore, the scope of the present disclosure should not be limited to the above embodiments, but should be defined by the following patent claims and the equivalents of the claims of the present disclosure.

Claims

1. A method performed by a device for generating uneven brightness compensation data, the method comprising: generating optical information of a plurality of pixels of a working display panel based on the test data; generating original uneven brightness compensation data based on the optical information to compensate for input video data provided to the display panel; extracting a high spatial frequency component and a low spatial frequency component from the original uneven brightness compensation data; generating a compressed high spatial frequency component by compressing the high spatial frequency component based on a first compression algorithm; generating a compressed low spatial frequency component by compressing the low spatial frequency component based on a second compression algorithm; as well as The compressed high spatial frequency components and the compressed low spatial frequency components are stored in an external storage circuit.

2. The method according to claim 1, wherein: Extracting the high spatial frequency component and the low spatial frequency component from the original uneven brightness compensation data comprises: providing the original luminance unevenness compensation data to a spatial frequency low pass filter to extract the low spatial frequency component from the original luminance unevenness compensation data; and The high spatial frequency component is extracted based on the original luminance unevenness compensation data and the low spatial frequency component extracted from the original luminance unevenness compensation data via the spatial frequency low pass filter.

3. The method according to claim 2, wherein: The high spatial frequency component corresponds to a difference between the original uneven brightness compensation data and the low spatial frequency component.

4. The method according to claim 2, wherein: The high spatial frequency component corresponds to a difference between a result of compressing and then decompressing the low spatial frequency component and the original brightness unevenness compensation data.

5. The method according to claim 1, wherein: Generating the compressed high spatial frequency components comprises: generating a high spatial frequency component with reduced bit width by performing a bit width reduction operation on at least one compensation value among a plurality of compensation values ​​included in the high spatial frequency component; and The compressed high spatial frequency component is generated by compressing the high spatial frequency component with reduced bit width based on the first compression algorithm.

6. The method according to claim 1, wherein: The first capacity of the original brightness unevenness compensation data is equal to the second capacity of the high spatial frequency component, and The first capacity of the original uneven brightness compensation data is equal to the third capacity of the low spatial frequency component.

7. The method according to claim 1, wherein: The original uneven brightness compensation data is a lookup table including a plurality of compensation values; and The high spatial frequency component and the low spatial frequency component are determined based on magnitudes of the plurality of compensation values ​​and an arrangement of the plurality of compensation values ​​in the lookup table.

8. The method according to claim 7, wherein: Each of the plurality of compensation values ​​represents a brightness level to be compensated for at least one pixel among the plurality of pixels on the display panel, and The arrangement of the plurality of compensation values ​​in the lookup table is determined based on an arrangement of the at least one pixel corresponding to at least one compensation value among the plurality of compensation values ​​on the display panel.

9. The method according to claim 1, wherein: The compression ratio of the second compression algorithm is higher than the compression ratio of the first compression algorithm.

10. The method according to claim 1, wherein: The display panel is configured to be controlled by a display driving circuit, and The display driving circuit is configured to provide a signal of equal magnitude to each column of the display panel based on the test data.

11. A display driving circuit for controlling a display panel, the display driving circuit comprising: a first decompression circuit configured to generate first uneven brightness compensation data by decompressing the first compressed uneven brightness compensation data; a second decompression circuit configured to generate second uneven brightness compensation data by decompressing the second compressed uneven brightness compensation data; a brightness unevenness compensation data merging circuit configured to generate third brightness unevenness compensation data by merging the first brightness unevenness compensation data and the second brightness unevenness compensation data; as well as a brightness unevenness compensation circuit configured to generate output video data corresponding to input video data provided from an external device based on the third brightness unevenness compensation data, The spatial frequency of the first uneven brightness compensation data is higher than the spatial frequency of the second uneven brightness compensation data. 12 . The display driving circuit according to claim 11 , further comprising a timing controller configured to control the display panel based on the output video data.

13. The display driving circuit according to claim 11, wherein: The first decompression circuit and the second decompression circuit operate based on two different compression algorithms.

14. The display driving circuit according to claim 13, wherein: A first ratio of a capacity of the second compressed brightness unevenness compensation data to a capacity of the second brightness unevenness compensation data is smaller than a second ratio of a capacity of the first compressed brightness unevenness compensation data to a capacity of the first brightness unevenness compensation data.

15. The display driving circuit according to claim 11, wherein: The capacity of the first brightness unevenness compensation data is equal to the capacity of the second brightness unevenness compensation data, and The capacity of the first uneven brightness compensation data is equal to the capacity of the third uneven brightness compensation data.

16. The display driving circuit according to claim 11, wherein: The third uneven brightness compensation data includes a plurality of compensation values, and At least one compensation value among the plurality of compensation values ​​is used to compensate for uneven brightness of at least one pixel included in the display panel.

17. A device for generating data for compensating for uneven brightness, the device comprising: an optical measurement circuit configured to generate optical information including a plurality of brightness values ​​of a plurality of pixels on an operating display panel based on the test data; a spatial frequency component extraction circuit configured to extract a high spatial frequency component of the optical information and a low spatial frequency component of the optical information from the optical information based on the plurality of brightness values; a first compensation data generating circuit configured to generate first brightness unevenness compensation data corresponding to the plurality of pixels based on the high spatial frequency component of the optical information; a second compensation data generating circuit configured to generate second brightness unevenness compensation data corresponding to the plurality of pixels based on the low spatial frequency component of the optical information; a first compression circuit configured to compress the first uneven brightness compensation data based on a first compression algorithm and provide the compressed first uneven brightness compensation data to an external device; as well as A second compression circuit is configured to compress the second brightness unevenness compensation data based on a second compression algorithm and provide the compressed second brightness unevenness compensation data to the external device.

18. The device for generating uneven brightness compensation data according to claim 17, wherein: The compression ratio of the second compression algorithm is higher than the compression ratio of the first compression algorithm.

19. The device for generating uneven brightness compensation data according to claim 18, wherein: The capacity of the first brightness unevenness compensation data is equal to the capacity of the second brightness unevenness compensation data, and The capacity of the compressed first brightness unevenness compensation data is greater than the capacity of the compressed second brightness unevenness compensation data.

20. The device for generating uneven brightness compensation data according to claim 17, wherein: The external device is a memory circuit included in a display driving circuit that controls the display panel.

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