Driver circuit and method for compensating pixel value of display pixel

Abstract

The invention provides a driver circuit and a method for compensating a pixel value of a display pixel. The driver circuit includes a controller circuit. The controller circuit is configured to perform an image compensation operation on a display pixel of an image sensing area of the display panel to compensate a pixel value of the display pixel using a first compensation value. The image sensing region is a circular region including an image sensor. The controller circuit determines a first compensation value according to a position of the display pixel in the image sensing area.

Description

Technical Field

[0001] The present invention relates to an electronic circuit and a method for compensating data, and more particularly to a driver circuit and a method for compensating pixel values ​​of display pixels. Background Art

[0002] Since the Organic Light-Emitting Diode (OLED) panel is a self-luminous panel, it is suitable for developing camera under display (CUD) products. CUD products are gradually being applied to OLED panels. However, there are still some problems to be solved in CUD products, the main problem is how to improve the transmittance of the CUD area. One way to solve this problem is to reduce the size or number of luminous pixels so that the driving circuit can handle more luminous pixels. However, this method will increase the visibility of the normal area boundary and reduce the resolution, making the normal area boundary more obvious. In addition, large changes in brightness will also increase the difficulty of defect correction (demura). Summary of the invention

[0003] The present invention relates to a driver circuit and a method for compensating pixel values ​​of display pixels, wherein the driver circuit and the method can improve the uneven brightness of an image sensing area (eg, a CUD area) of a display panel.

[0004] An embodiment of the present invention provides a driver circuit, including a controller circuit. The controller circuit is configured to perform an image compensation operation on display pixels of an image sensing area of ​​a display panel to compensate pixel values ​​of the display pixels using a first compensation value. The image sensing area is a circular area including an image sensor. The controller circuit determines the first compensation value according to the position of the display pixel in the image sensing area.

[0005] In an embodiment of the present invention, the controller circuit determines the weight value according to the position of the display pixel in the image sensing area. The first compensation value is obtained by modifying the second compensation value according to the weight value.

[0006] In an embodiment of the present invention, the controller circuit is further configured to perform an image compensation operation on display pixels of the non-image sensing area of ​​the display panel to compensate pixel values ​​of the display pixels of the non-image sensing area using the second compensation value.

[0007] In an embodiment of the present invention, a plurality of lookup tables are set for the image sensing area, and the lookup tables record the relationship between the weight value and the position of the display pixel.

[0008] In an embodiment of the present invention, the controller circuit determines the weight value based on a lookup table.

[0009] In an embodiment of the present invention, different lookup tables are set for different areas of the image sensing area for a given pixel value.

[0010] In an embodiment of the present invention, different lookup tables are set for different pixel values ​​of display pixels for a specified area of ​​the image sensing region.

[0011] In an embodiment of the present invention, different regions of the image sensing area have different block sizes, and the block size indicates the number of display pixels that share the same weight value.

[0012] In an embodiment of the present invention, a lookup table is set for a designated pixel value by obtaining the grayscale change and the brightness change of the image sensing area.

[0013] In an embodiment of the present invention, the driver circuit further comprises a storage circuit. The storage circuit is coupled to the controller circuit and is configured to store the lookup table.

[0014] In an embodiment of the present invention, the image sensing area includes a first area, a second area and a third area. The first area is a circular area. The second area is an annular area surrounding the first area, and the third area is an annular area surrounding the second area.

[0015] In an embodiment of the present invention, the first area includes an image sensor and display pixels, the second area includes a driving circuit and display pixels, and the third area includes display pixels.

[0016] An embodiment of the present invention provides a method for compensating a pixel value of a display pixel. The method includes: receiving pixel data and determining a position of a display pixel to which the pixel data is to be written; when it is determined that the position of the display pixel is in an image sensing area of ​​a display panel, determining a first compensation value according to the position of the display pixel in the image sensing area, wherein the image sensing area is a circular area including an image sensor; and performing an image compensation operation on the display pixel of the image sensing area to compensate the pixel value of the display pixel using the first compensation value.

[0017] In an embodiment of the present invention, the step of determining the first compensation value according to the position of the display pixel in the image sensing area includes: determining a weight value according to the position of the display pixel in the image sensing area; and modifying the second compensation value according to the weight value to obtain the first compensation value.

[0018] In an embodiment of the present invention, the method for compensating the pixel value of a display pixel also includes: when it is determined that the position of the display pixel is in a non-image sensing area of ​​the display panel, performing an image compensation operation on the display pixel in the non-image sensing area to compensate the pixel value of the display pixel in the non-image sensing area using a second compensation value.

[0019] In an embodiment of the present invention, the method for compensating pixel values ​​of display pixels further includes: setting a plurality of lookup tables for the image sensing area by obtaining grayscale changes and brightness changes of the image sensing area, wherein the lookup tables record the relationship between weight values ​​and positions of display pixels.

[0020] In an embodiment of the present invention, the step of determining the first compensation value according to the position of the display pixel in the image sensing area further includes: determining a weight value according to a lookup table.

[0021] In an embodiment of the present invention, the step of setting a plurality of lookup tables for the image sensing area includes: setting different lookup tables for different areas of the image sensing area for a specified pixel value.

[0022] In an embodiment of the present invention, the step of setting a plurality of lookup tables for the image sensing area includes: setting different lookup tables for different pixel values ​​of display pixels in a designated area of ​​the image sensing area.

[0023] In an embodiment of the present invention, different regions of the image sensing area have different block sizes, and the block size indicates the number of display pixels that share the same weight value.

[0024] In order to make the foregoing content easier to understand, several embodiments are described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the disclosure and together with the description serve to explain the principles of the disclosure.

[0026] Figure 1 is a schematic diagram showing an electronic device according to an embodiment of the present invention.

[0027] Figure 2 It is shown Figure 1 A block diagram of an electronic device according to an embodiment.

[0028] Figure 3 A lookup table for specifying pixel values ​​according to an embodiment of the present invention is shown.

[0029] Figure 4 is a flow chart illustrating a method for compensating pixel values ​​of display pixels according to an embodiment of the present invention.

[0030] Figure 5 is a flow chart illustrating a method for compensating pixel values ​​of display pixels according to another embodiment of the present invention.

[0031] Figure 6 A lookup table for specifying pixel values ​​according to another embodiment of the present invention is shown.

[0032] Figure 7 A lookup table for different pixel values ​​according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0033] The following embodiments are provided to elaborate on the present disclosure, but the present disclosure is not limited to the provided embodiments, and the provided embodiments may be appropriately combined. The terms "coupling / coupled" or "connecting / connected" used in the specification (including claims) of this application may refer to any direct connection method or indirect connection method. For example, "a first device is coupled to a second device" should be interpreted as "a first device is directly connected to a second device" or "a first device is indirectly connected to a second device via other devices or connection methods". In addition, the term "signal" may refer to current, voltage, charge, temperature, data, electromagnetic waves, or any one or more signals.

[0034] Figure 1 is a schematic diagram showing an electronic device according to an embodiment of the present invention. Figure 2 It is shown Figure 1 A block diagram of an electronic device according to an embodiment of the present invention. Figure 1 and Figure 2 , the electronic device 100 includes a driver circuit 110 and a display panel 120. The driver circuit 110 may be configured to be coupled to the display panel 120. The display panel 120 may be an OLED panel, but is not limited thereto.

[0035] The driver circuit 110 includes a controller circuit 112. The controller circuit 112 is adapted to perform an image compensation operation (e.g., a defect correction operation) on the display panel 120 so that the display panel 120 can display good image quality. For example, the controller circuit 112 receives the pixel data PD, and according to the position of the display pixel to which the pixel data PD is to be written, the controller circuit 112 compensates the pixel data PD using the first compensation value CV1 or the second compensation value CV2.

[0036] The display panel 120 includes an image sensing area 122 and a non-image sensing area 124. The image sensing area 122 is a circular area including an image sensor for sensing an image. The image sensor may be a camera under display (CUD). The image sensing area 122 also includes display pixels for displaying an image. The image sensing area 122 is a transparent area with low reflection and high light transmission. In an embodiment, when a photo is not taken, the image sensing area 122 can display an image normally, and when a photo is taken, the image sensing area 122 becomes a transparent glass.

[0037] The image sensing area 122 includes a first area 221, a second area 222, and a third area 223. The first area 221 is a circular area and includes an image sensor and display pixels. The second area 222 is an annular area surrounding the first area 221. The second area 222 includes a driving circuit and display pixels. The driving circuit may be a circuit for driving the image sensor. The third area 223 is another annular area surrounding the second area 222. The third area 223 includes display pixels. In the present embodiment, the first area 221, the second area 222, and the third area 223 are concentric circles / concentric rings.

[0038] For the sake of clarity and simplicity, Figure 1 The structures of the image sensor, display pixel and driving circuit are not shown in the figure, and the structural embodiments of the image sensor, display pixel and driving circuit can refer to the common knowledge in the relevant fields to obtain sufficient teachings, suggestions and implementation instructions.

[0039] The non-image sensing area 124 is an area including display pixels, touch sensors and / or fingerprint sensors to perform display functions, touch sensing functions and / or fingerprint sensing functions, respectively. The driver circuit 110 is also suitable for driving the display panel 120 to perform display functions, touch sensing functions and / or fingerprint sensing functions.

[0040] against Figure 2 In the embodiment, the component hardware structure, the controller circuit 112 can be a processor with computing capabilities. Alternatively, the controller circuit 112 can be designed by a hardware description language (HDL) or any other digital circuit design method familiar to technicians in the field, and the controller circuit 112 can be a hardware circuit implemented by a field programmable gate array (FPGA), a complex programmable logic device (CPLD) or an application-specific integrated circuit (ASIC). In addition, the hardware structure of the controller circuit 112 can refer to the common knowledge in the relevant field to obtain sufficient teachings, suggestions and implementation instructions.

[0041] In the present embodiment, the controller circuit 112 is configured to perform an image compensation operation on the display panel 120. The image compensation operation may be a defect correction operation. The defect correction operation is a technique for eliminating defects (mura) of a display and balancing the brightness or grayscale of an image. For example, the controller circuit 112 receives pixel data PD and determines the position of a display pixel to which the pixel data PD is to be written. When it is determined that the position of the display pixel is in the non-image sensing area 124, the controller circuit 112 performs an image compensation operation on the display pixel of the non-image sensing area 124 of the display panel 120 to compensate the pixel value of the display pixel using the second compensation value CV2. The second compensation value CV2 can be obtained by referring to a known and suitable defect correction method in the related art.

[0042] When it is determined that the position of the display pixel is in the image sensing area 122, the controller circuit 112 performs an image compensation operation on the display pixel of the image sensing area 122 of the display panel 120 to compensate the pixel value of the display pixel using the first compensation value CV1. The first compensation value CV1 can be obtained by modifying the second compensation value CV2 according to the weight value Wd, and the weight value Wd can be expressed using the following equation:

[0043] CV1 = (1+Wd) × CV2 + bn (1)

[0044] Wherein CV1 is the first compensation value, CV2 is the second compensation value of the image sensing area 122 before modification, Wd is the weight value, and bn is a preset adjustment parameter. For the first area 221, the second area 222 and the third area 223, the subscript n of the adjustment parameter bn is equal to 1, 2 or 3 respectively.

[0045] In this embodiment, if Figure 3 As shown in , the controller circuit 112 can determine the weight value Wd according to the position of the display pixel in the image sensing area 122. Then, the controller circuit 112 uses equation (1) to calculate the first compensation value CV1. Therefore, the controller circuit 112 determines the first compensation value CV1 according to the position of the display pixel in the image sensing area 122.

[0046] Figure 3 A lookup table for specifying pixel values ​​according to an embodiment of the present invention is shown. Figure 3 The lookup table 300 for specifying pixel values ​​is configured to determine the weight value of the display pixel and present the lookup table 300 in the form of a curve. The lookup table 300 for specifying pixel values ​​can be set in advance for the image sensing area 122. The lookup table 300 records the relationship between the weight value and the position of the display pixel. The pixel value of the display pixel can be a grayscale value or a brightness value.

[0047] The controller circuit 112 calculates the distance d between the display pixel and the center O of the circle, and determines the weight value Wd of the display pixel according to the distance d and the look-up table 300. For example, when the distance d = d1 and 0 < d1 ≤ D1, the controller circuit 112 determines that the weight value Wd is Wd1. When the distance d = d2 and D1 < d2 ≤ D2, the controller circuit 112 determines that the weight value Wd is Wd2. When the distance d = d3 and D2 < d2 ≤ D3, the controller circuit 112 determines that the weight value Wd is Wd3. In Figure 3 D1, D2, and D3 are the radii of the first region 221, the second region 222, and the third region 223, respectively.

[0048] Figure 4 is a flowchart showing a method for compensating the pixel value of a display pixel according to an embodiment of the present invention. Referring to Figures 1 to 3 , the method for compensating the pixel value of a display pixel is at least applicable to Figure 1 and Figure 2 the electronic device 100, but the present invention is not limited thereto.

[0049] Taking the electronic device 100 as an example, in step S100, the controller circuit 112 receives the pixel data PD. In step S110, the controller circuit 112 determines the position of the display pixel to which the pixel data PD is to be written.

[0050] When the controller circuit 112 determines that the position of the display pixel is in the non-image sensing area 124, the process proceeds to step S120. In step S120, the controller circuit 112 performs an image compensation operation on the display pixel in the non-image sensing area 124 to compensate the pixel value of the display pixel using the second compensation value CV2.

[0051] When the controller circuit 112 determines that the position of the display pixel is in the image sensing area 122, the process proceeds to step S130. In step S130, the controller circuit 112 determines the weight value Wd and the first compensation value CV1 according to the position of the display pixel in the image sensing area 122. For example, the weight value Wd can be determined according to the look-up table 300, and the first compensation value CV1 can be determined according to Equation (1). In step S140, the controller circuit 112 performs an image compensation operation on the display pixel in the image sensing area 122 to compensate the pixel value of the display pixel using the first compensation value CV1.

[0052] The method for compensating the pixel value of a display pixel according to the embodiment of the present invention has provided sufficient teachings, suggestions, and implementation descriptions in the embodiments of Figures 1 to 3 and will not be repeated herein.

[0053] Figure 5is a flow chart showing a method for compensating pixel values ​​of display pixels according to another embodiment of the present invention. Figures 1 to 4 , the method for compensating the pixel value of a display pixel is at least suitable for Figure 1 and Figure 2 The electronic device 100 is provided, but the present invention is not limited thereto.

[0054] Taking the electronic device 100 as an example, in step S200, the controller circuit 112 receives the pixel data PD and determines the position of the display pixel to which the pixel data PD is to be written. In step S210, when it is determined that the position of the display pixel is in the image sensing area 122 of the display panel 120, the controller circuit 112 determines the first compensation value CV1 according to the position of the display pixel in the image sensing area 122. In step S220, the controller circuit 112 performs an image compensation operation on the display pixel of the image sensing area 122 to compensate the pixel value of the display pixel using the first compensation value CV1.

[0055] The method for compensating the pixel value of a display pixel according to an embodiment of the present invention has been described in Figures 1 to 4 The embodiments of the present invention provide sufficient teachings, suggestions and implementation instructions, and therefore will not be repeated in this article.

[0056] In this embodiment, a plurality of lookup tables may be pre-set for the image sensing area 122, and the lookup tables record the relationship between the weight value Wd and the position of the display pixel. The lookup tables will be described below.

[0057] Figure 6 A lookup table for specifying pixel values ​​according to another embodiment of the present invention is shown. Figure 7 A lookup table for different pixel values ​​according to an embodiment of the present invention is shown.

[0058] exist Figure 6 600 for gray level G8 (specified pixel value) is shown as an example. The lookup table 600 includes 600_L and 600_R. The lookup table 600_R is set for gray level G8 by obtaining the gray level change or brightness change of the image sensing area 122. The lookup table 600_L and the lookup table 600_R are mirror images of each other. The lookup table 600_R is used as an example below, and the lookup table 600_L can be deduced in the same way.

[0059] Specifically, pixel data PD of grayscale G8 is input to drive the image sensing area 122 to display an image. The grayscale change or brightness change of the image sensing area 122 is obtained by an external image acquisition device and converted into a digital signal. The digital signal can be further normalized to obtain weight values ​​at different positions. Curve fitting is performed according to the weight values ​​to obtain a curve 600_R, and the curve 600_R is divided into regions CZ1, CZ2, and CZ3. Block sizes BK are set for different regions CZ1, CZ2, and CZ3. The block size BK indicates the number of display pixels that share the same weight value.

[0060] For example, the block size BK is set to 1 for the zone CZ1. This indicates that each display pixel of the first zone 221 has its own weight value and is recorded in Figure 7 The block size BK=2 is set for the area CZ2. This indicates that every two adjacent display pixels of the second area 222 share the same weight value and are recorded in Figure 7 The block size BK=4 is set for the area CZ3. This indicates that every four adjacent display pixels of the third area 223 share the same weight value and are recorded in Figure 7 That is, different regions 221, 222, and 223 of the image sensing area 122 have different block sizes. For a given pixel value G8, different lookup tables G8_1, G8_2, and G8_3 are set for different regions 221, 222, and 223 of the image sensing area 122.

[0061] Therefore, for grayscale G8, a lookup table 600_R including G8_1, G8_2 and G8_3 can be obtained. In the lookup tables G8_1, G8_2 and G8_3, n is the nth display pixel from the inside to the outside, dn*bk, dn*bk-D1 and dn*bk-D2 are display pixel positions, and Wd is a weight value. The lookup tables for other grayscales can be deduced in the same way. For example, in Figure 7 In the embodiment, for grayscale G16, a lookup table including G16_1, G16_2 and G16_3 can be obtained, and for grayscale G32, a lookup table including G32_1, G32_2 and G32_3 can be obtained.

[0062] In addition, for a specified area of ​​the image sensing area 122, different lookup tables are set for different pixel values ​​of display pixels. Figure 7In the embodiment, for the first zone 221 (i.e., zone CZ1), different lookup tables G8_1, G16_1, and G32_1 are set for displaying different grayscales G8, G16, and G32 of pixels. Similarly, for the second zone 222 (i.e., zone CZ2), different lookup tables G8_2, G16_2, and G32_2 are set for displaying different grayscales G8, G16, and G32 of pixels. For the third zone 223 (i.e., zone CZ3), different lookup tables G8_3, G16_3, and G32_3 are set for displaying different grayscales G8, G16, and G32 of pixels.

[0063] Therefore, the controller circuit 112 can be based on Figure 7 The weight value Wd is determined by a lookup table, but the present invention is not limited thereto. In an embodiment, the driver circuit 110 may further include a storage circuit, which is coupled to the controller circuit 112 and configured to store the lookup table. Since the block sizes of the different regions 221, 222, and 223 of the image sensing area 122 can be set, the lookup table does not need to record the weight values ​​of all display pixels, so that there is no need to add additional storage space for defect correction, thereby reducing the manufacturing cost of the product.

[0064] In summary, in an embodiment of the present invention, the weight values ​​of the three areas of the image sensing area can be obtained by analyzing the optical data obtained. When displaying an image, the controller circuit searches for the weight value based on the input data and the lookup table, and searches different lookup tables considering the display pixel position. The controller circuit obtains the weight values ​​of different positions and calculates the first compensation value, thereby compensating the pixel value of the display pixel to perform an image compensation operation. Therefore, the driver circuit and the method for compensating the pixel value of the display pixel of the embodiment of the present invention can improve the uneven brightness of the image sensing area and make the brightness of the display panel more uniform.

[0065] It is apparent to those skilled in the art that various modifications and variations may be made to the disclosed embodiments without departing from the scope or spirit of the present disclosure. In summary, the present disclosure is intended to cover modifications and variations within the scope of the following claims and their equivalents.

Claims

1. A driver circuit, comprising: A controller circuit is configured to perform an image compensation operation on display pixels of an image sensing area of ​​a display panel to compensate for pixel values ​​of the display pixels using a first compensation value, wherein the image sensing area is a circular area including a plurality of image sensors, and the controller circuit determines the first compensation value based on a position of the display pixel in the image sensing area.

2. The driver circuit of claim 1, wherein the controller circuit determines a weight value according to the position of the display pixel in the image sensing area, and the first compensation value is obtained by modifying a second compensation value according to the weight value.

3. The driver circuit according to claim 2, wherein the controller circuit is further configured to perform the image compensation operation on display pixels of a non-image sensing area of ​​the display panel to compensate for the pixel values ​​of the display pixels of the non-image sensing area using the second compensation value. 4 . The driver circuit according to claim 2 , wherein a plurality of lookup tables are set for the image sensing area, and the plurality of lookup tables record the relationship between a plurality of weight values ​​and positions of a plurality of display pixels. 5 . The driver circuit of claim 4 , wherein the controller circuit determines the weight values ​​based on the plurality of lookup tables. 6 . The driver circuit of claim 4 , wherein for a given pixel value, different lookup tables are set for different regions of the image sensing area. 7 . The driver circuit of claim 4 , wherein for a specified area of ​​the image sensing region, different lookup tables are set for different pixel values ​​of the plurality of display pixels.

8. The driver circuit of claim 4, wherein different regions of the image sensing area have different block sizes, and the block size indicates the number of display pixels that share the same weight value.

9. The driver circuit of claim 4, wherein the plurality of lookup tables are set for designated pixel values ​​by obtaining grayscale variations and brightness variations of the image sensing area.

10. The driver circuit according to claim 4, further comprising: A storage circuit is coupled to the controller circuit and is configured to store the plurality of look-up tables.

11. The driver circuit according to claim 1, wherein the image sensing area includes a first area, a second area, and a third area, and the first area is a circular area, the second area is an annular area surrounding the first area, and the third area is an annular area surrounding the second area. 12 . The driver circuit of claim 11 , wherein the first region includes the plurality of image sensors and a plurality of display pixels, the second region includes a plurality of drive circuits and a plurality of display pixels, and the third region includes a plurality of display pixels.

13. A method for compensating pixel values ​​of a plurality of display pixels, comprising: receiving pixel data and determining a position of a display pixel among the plurality of display pixels to which the pixel data is to be written; When it is determined that the position of the display pixel is in an image sensing area of ​​a display panel, determining a first compensation value according to the position of the display pixel in the image sensing area, wherein the image sensing area is a circular area including a plurality of image sensors; as well as An image compensation operation is performed on the display pixels of the image sensing area to compensate the pixel values ​​of the display pixels using the first compensation values.

14. The method for compensating the pixel values ​​of the plurality of display pixels according to claim 13, wherein the step of determining the first compensation value according to the position of the display pixel in the image sensing area comprises: determining a weight value according to the position of the display pixel in the image sensing area; as well as The second compensation value is modified according to the weight value to obtain the first compensation value.

15. The method for compensating the pixel values ​​of the plurality of display pixels according to claim 14, further comprising: When it is determined that the position of the display pixel is in a non-image sensing area of ​​the display panel, the image compensation operation is performed on the display pixel in the non-image sensing area to compensate the pixel value of the display pixel in the non-image sensing area using the second compensation value.

16. The method for compensating the pixel values ​​of the plurality of display pixels according to claim 14, further comprising: A plurality of lookup tables are set for the image sensing area by obtaining the grayscale change and the brightness change of the image sensing area, wherein the plurality of lookup tables record the relationship between a plurality of weight values ​​and the positions of the plurality of display pixels.

17. The method for compensating the pixel values ​​of the plurality of display pixels according to claim 16, wherein the step of determining the first compensation value according to the position of the display pixel in the image sensing area further comprises: The weight values ​​are determined according to the plurality of lookup tables.

18. The method for compensating the pixel values ​​of the plurality of display pixels according to claim 16, wherein the step of setting the plurality of lookup tables for the image sensing area comprises: For a given pixel value, different lookup tables are set for different areas of the image sensing area.

19. The method for compensating the pixel values ​​of the plurality of display pixels according to claim 16, wherein the step of setting the plurality of lookup tables for the image sensing area comprises: For a designated area of ​​the image sensing region, different lookup tables are set for different pixel values ​​of the plurality of display pixels.

20. The method for compensating the pixel values ​​of the plurality of display pixels according to claim 16, wherein different regions of the image sensing area have different block sizes, and the block size indicates the number of display pixels that share the same weight value.

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