Display and backlight compensation method thereof

Abstract

The invention discloses a display and a backlight compensation method thereof, the display comprises a backlight unit and a driving unit coupled with the backlight unit, and the backlight compensation method of the display comprises the following steps: providing a gamma value of the display; performing dimming of each area of the backlight unit according to the gamma value; obtaining an area peak brightness value of each area in the backlight unit; acquiring a brightness area of the backlight unit and a corresponding brightness adjustment ratio; the driving unit obtains a first display brightness value corresponding to each area in the backlight unit according to the product of the area peak brightness value of each area and the brightness adjustment ratio; and performing brightness compensation in each area of the backlight unit according to the first display brightness value. Therefore, a backlight compensation mode for maintaining the optical quality is achieved, and the brightness and the gamma value can be maintained under different brightness areas.

Description

Technical Field

[0001] The invention relates to a backlight compensation technology, and in particular to a display and a backlight compensation method thereof. Background Art

[0002] When traditional sub-millimeter LED displays are dimmed locally, the dimming algorithm is mainly based on power saving, so it can be found that the key optical properties cannot be maintained. For example, the gamma value before and after local dimming may change from 2.2 to 2.8. Figure 1 As shown, this may reduce the resolution of the image data and distort it, for example, the overall display screen becomes darker and the dark details are distorted. In addition, sub-millimeter light-emitting diodes will use light expansion compensation or image data to directly increase brightness compensation, but both will cause halo to be generated and / or greatly increase, causing the resolution of the image data to be reduced and distorted again. Summary of the invention

[0003] The present invention provides an adjustable backlight compensation method, which mainly does not reduce the image data resolution (i.e. maintains the image data resolution) and maintains the optical quality of the backlight compensation method, as well as a display and a backlight compensation method thereof that can maintain brightness and gamma value under different brightness areas.

[0004] The display provided by the present invention includes a backlight unit and a driving unit, wherein the backlight unit has a first display brightness value, a brightness area and a corresponding brightness adjustment ratio, and has multiple regions, and each region has a regional peak brightness value; the driving unit is coupled to the backlight unit, and calculates the first display brightness value based on the product of the multiple regional peak brightness values ​​and the brightness adjustment ratio; wherein each first display brightness value corresponds to each region in the backlight unit.

[0005] In one embodiment of the present invention, the backlight unit further includes: a black screen grayscale measurement value, a white screen grayscale measurement value, and a second display brightness value, wherein the second display brightness value is obtained by normalizing the difference between the black screen grayscale measurement value and the white screen grayscale measurement value as the base and raising the gamma value to the power of the exponent.

[0006] The present invention provides a backlight compensation method for a display, wherein the display has a driving unit and a backlight unit, and the backlight compensation method includes: providing a gamma value of the display; performing dimming of each area of ​​the backlight unit according to the gamma value; obtaining a regional peak brightness value of each area in the backlight unit; obtaining a brightness area of ​​the backlight unit and a corresponding brightness adjustment ratio; the driving unit obtains a first display brightness value corresponding to each area in the backlight unit according to the product of the regional peak brightness value of each area and the brightness adjustment ratio; and performing brightness compensation in each area of ​​the backlight unit according to the first display brightness value.

[0007] In one embodiment of the present invention, the above-mentioned execution of dimming of each area of ​​the backlight unit in the display based on the gamma value of the display includes: taking the difference between the black screen grayscale measurement value and the white screen grayscale measurement value of the backlight unit as the base and taking the gamma value as the exponent to obtain the second display brightness value of the backlight unit; and executing dimming of each area of ​​the backlight unit based on the second display brightness value.

[0008] In one embodiment of the present invention, the gamma value is 2.2.

[0009] In one embodiment of the present invention, the brightness area and the brightness adjustment ratio are inversely proportional.

[0010] In one embodiment of the present invention, the brightness area is the ratio of a white screen area in the backlight unit to the panel area of ​​the backlight unit.

[0011] The present invention compensates for the brightness difference after dimming of the backlight unit area and adjusts the brightness adjustment ratio of the backlight unit in multiple dimensions according to different brightness areas, thereby achieving the effect of not reducing the image data resolution and maintaining the optical quality, and maintaining the brightness and gamma value under different brightness areas.

[0012] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites a preferred embodiment and describes it in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a graph of the gamma value of the display;

[0014] Figure 2 A system block diagram of a display provided by an embodiment of the present invention;

[0015] Figure 3 A schematic diagram of a backlight unit provided by an embodiment of the present invention;

[0016] Figure 4 A flow chart of a backlight compensation method provided by an embodiment of the present invention;

[0017] Figure 5 A flowchart of performing dimming of each area of ​​a backlight unit according to a gamma value provided by an embodiment of the present invention;

[0018] Figure 6 A schematic diagram of a regional peak brightness value and its product with a brightness adjustment ratio provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The present invention is particularly described by the following examples, which are only used for illustration, because for those skilled in the art, various changes and modifications can be made without departing from the spirit and scope of the present disclosure, so the protection scope of the present disclosure should be determined by the scope of the attached claims. Throughout the specification and the claims, unless the content clearly specifies, the meaning of "a", "an" and "the" includes such a description including "one or at least one" components or ingredients. In addition, as used in the present invention, unless it is obvious from the specific context that the plurality is excluded, the singular article also includes the description of plural components or ingredients. Moreover, when used in this description and the following claims, unless the content clearly specifies, the meaning of "in which" may include "in which" and "on which". The terms used in the specification and the claims generally have the ordinary meaning of each term used in this field, in the content disclosed herein and in the specific content, unless otherwise specified. Certain terms used to describe the present invention will be discussed below or elsewhere in this specification to provide practitioners with additional guidance regarding the description of the present invention. Examples anywhere throughout the specification, including the use of examples of any term discussed herein, are provided for illustrative purposes only and certainly do not limit the scope and meaning of the present invention or any exemplified term. Likewise, the present invention is not limited to the various embodiments set forth in this specification.

[0020] As used herein, the terms "substantially", "around", "about" or "approximately" shall generally mean within 20% of a given value or range, preferably within 10%. In addition, the quantities provided herein may be approximate, thus meaning that the terms "approximately", "about" or "approximately" may be used to represent the same unless otherwise stated. When a quantity, concentration or other numerical value or parameter has a specified range, a preferred range or lists upper and lower ideal values, it shall be deemed to specifically disclose all ranges consisting of any upper and lower limit pairs or ideal values, regardless of whether the same ranges are disclosed separately. For example, if a certain length of a range is disclosed as X cm to Y cm, it shall be deemed to disclose a length of H cm and H may be any real number between X and Y.

[0021] In addition, if the word "coupled" or "connected" is used, it includes any direct and indirect electrical connection means. For example, if the text describes that a first device is electrically coupled to a second device, it means that the first device can be directly connected to the second device, or indirectly connected to the second device through other devices or connection means. In addition, if the transmission or provision of an electrical signal is described, a person skilled in the art should understand that the transmission process of the electrical signal may be accompanied by attenuation or other non-ideal changes, but if the source and receiving end of the transmission or provision of the electrical signal are not specifically stated, they should be regarded as the same signal in essence. For example, if an electrical signal S is transmitted (or provided) from terminal A of an electronic circuit to terminal B of the electronic circuit, a voltage drop may be generated through the source and drain of a transistor switch and / or possible stray capacitance. However, if the purpose of this design is not to deliberately use the attenuation or other non-ideal changes generated during the transmission (or provision) to achieve certain specific technical effects, the electrical signal S at terminals A and B of the electronic circuit should be regarded as the same signal in essence.

[0022] It is understood that the terms "comprising", "including", "having", "containing", "involving", etc. used herein are open-ended, that is, they mean including but not limited to. In addition, any embodiment or claim scope of the present invention is not required to achieve all the objects, advantages or features disclosed in the present invention. In addition, the abstract part and the title are only used to assist in searching patent documents and are not used to limit the scope of the claims of the present invention.

[0023] See also Figure 2, which is a system block diagram of a display provided by an embodiment of the present invention. The display 1 provided by this embodiment includes a backlight unit 2, a display unit 3, and a driving unit 4, wherein the backlight unit 2 is a panel composed of a plurality of sub-millimeter light emitting diodes to provide backlight for the display 1, the display unit 3 is a panel composed of a plurality of pixel units to display image data, and the driving unit 4 is used to couple and drive the backlight unit 2 and the display unit 3. It can be noted that in addition to having a first display brightness value, a whole brightness area, and a corresponding brightness adjustment ratio, the backlight unit 2 also has a plurality of regions 21 on the backlight unit 2 such as Figure 3 As shown, each region 21 has a regional peak brightness value; and the driving unit 4 calculates the first display brightness value of each region 21 of the backlight unit 2 according to the product of the regional peak brightness value of each region 21 and the brightness adjustment ratio of the backlight unit 2. In addition, the driving unit 4 is further used to perform a backlight compensation method.

[0024] See also Figure 4 As shown, it is a flow chart of the backlight compensation method provided by an embodiment of the present invention. The backlight compensation method provided by the present embodiment is executed by the driving unit 4 in the display 1 to include the following operations, wherein whether the display unit 3 inputs an image data is not limited by this. Step S1: Provide the gamma value of the display 1, wherein the gamma value in the present embodiment is 2.2, but those skilled in the art can design different gamma values ​​according to actual needs. Step S3: Perform dimming of each area of ​​the backlight unit 2 according to the gamma value. Step S5: Obtain the regional peak brightness value of each area 21 in the backlight unit 2. Step S7: Obtain the brightness area of ​​the backlight unit 2 and the corresponding brightness adjustment ratio. Step S9: The driving unit 4 obtains the first display brightness value corresponding to each area 21 in the backlight unit 2 according to the product of the regional peak brightness value of each area 21 and the brightness adjustment ratio. Step S11: Perform brightness compensation in each area 21 of the backlight unit 2 according to the first display brightness value.

[0025] First, see Figure 5As shown, it is a flow chart of performing dimming of each area of ​​the backlight unit according to the gamma value provided by one embodiment of the present invention. It can be noted that in addition to the above-mentioned first display brightness value, brightness area, brightness adjustment ratio and regional peak brightness value, the backlight unit 2 also includes a black screen grayscale measurement value, a white screen grayscale measurement value and a second display brightness value. Therefore, performing dimming of each area of ​​the backlight unit according to the gamma value is based on the black screen grayscale measurement value and the white screen grayscale measurement value. The following operations are performed. Step S13: Based on the difference between the black screen grayscale measurement value and the white screen grayscale measurement value of the backlight unit 2, normalize it to the base and take the gamma value as the exponent to obtain the second display brightness value of the backlight unit 2, wherein the equation in step S13 represents (L0_m+(L255_m-L0_m)*(Ln_m / 255)) γ , where L0_m represents the black screen grayscale measurement value of the mth sub-millimeter LED, L255_m represents the white screen grayscale measurement value of the mth sub-millimeter LED, Ln_m represents the grayscale value of the mth sub-millimeter LED corresponding to the gamma value, n represents 0 to 255, and γ represents the gamma value of 2.2. The equation in step S13 represents one display brightness value with one sub-millimeter LED, which means that the display brightness value of the backlight unit 2 includes a plurality of display brightness values ​​corresponding to each of the plurality of sub-millimeter LEDs. Step S15: Perform dimming of each area of ​​the backlight unit 2 based on the second display brightness value. It can be noted that the size of each area 21 of the backlight unit 2 after regional dimming can be automatically adjusted according to the image data of the display unit 3 or according to the setting of the backlight unit 2, that is, the size of the area 21 can be as small as one sub-millimeter LED and as large as the entire panel, and the area 21 can be in different shapes such as rectangle and polygon, but the present invention is not limited thereto.

[0026] Next, please refer to Figure 4As shown, after the driving unit 4 performs the regional dimming of the backlight unit 2, the display brightness value of each millimeter light-emitting diode in each area 21 corresponding to each time can be obtained, and the area peak brightness value (area peak luminance / segment, APL) in the area 21 can be obtained. Then, the driving unit 4 finds the corresponding brightness adjustment ratio (luminance dependency of windows size, LOWS) according to the brightness area (windows size) of the backlight unit 2, wherein the brightness area is the ratio of the white screen area in the backlight unit 2 to the overall panel area of ​​the backlight unit 2, and different ratios will correspond to different brightness adjustment ratios, as shown in Table 1, wherein it can be found that the brightness area and the brightness adjustment ratio have an inverse relationship, and in addition, the white screen area in the backlight unit 2 and the overall panel area of ​​the backlight unit 2 can be different shapes such as rectangles and polygons, and the present invention is not limited thereto. Next, the driving unit 4 obtains the regional peak brightness value and the brightness adjustment ratio of each region 21 after the regional dimming, and then performs the product of the regional peak brightness value and the brightness adjustment ratio (APL*LOWS) of each region 21 to obtain the display brightness value of each region 21 in the backlight unit 2, so as to compensate for each region 21 in the backlight unit 2. Figure 6 As shown, the regional peak brightness value of each region 21 in the backlight unit 2 is, for example, Figure 6 As shown on the right side of the figure, the ratio of the white screen area in the backlight unit 2 to the overall panel area of ​​the backlight unit 2 is, for example, 50%, and the corresponding brightness adjustment ratio is 75%. The product of the regional peak brightness value of each region 21 and the brightness adjustment ratio is, for example, Figure 6 In addition, it can be noted that the number of regional peak brightness values ​​increases or decreases as the number of regions after regional dimming increases or decreases. Figure 6 This is only an example and the present invention is not limited thereto.

[0027] Table 1

[0028] Brightness Area Brightness adjustment ratio 10％ 100％ 30％ 85％ 50％ 75％ 70％ 60％ 100％ 50％

[0029] In summary, the display and backlight compensation method provided by the present invention can achieve the effect of not reducing the resolution of image data and maintaining optical quality, and can maintain brightness and gamma value under different brightness areas by compensating the brightness difference after dimming of the backlight unit area and adjusting the brightness adjustment ratio of the backlight unit according to different brightness areas. In addition, the backlight compensation method provided can be a composite condition other than area and brightness, and the present invention is not limited to this.

[0030] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A backlight compensation method for a display, characterized in that: The display has a driving unit and a backlight unit, and the backlight compensation method includes: Providing a gamma value of the display; Performing dimming of each area of ​​the backlight unit according to the gamma value; Obtaining a regional peak brightness value of each region in the backlight unit; Acquire the brightness area and the corresponding brightness adjustment ratio of the backlight unit; The driving unit obtains a first display brightness value corresponding to each area in the backlight unit according to the product of the area peak brightness value of each area and the brightness adjustment ratio; and Brightness compensation is performed in each area of ​​the backlight unit according to the first display brightness value.

2. The backlight compensation method according to claim 1, wherein: Performing dimming of each area of ​​the backlight unit according to the gamma value includes: Obtain a second display brightness value of the backlight unit based on a difference between a black screen grayscale measurement value and a white screen grayscale measurement value of the backlight unit normalized as a base and exponentially raised to the power of the gamma value; Each regional dimming of the backlight unit is performed based on the second display brightness value.

3. The backlight compensation method according to claim 1, wherein: The gamma value is 2.

2.

4. The backlight compensation method according to claim 1, wherein: The brightness area has an inversely proportional relationship to the brightness adjustment ratio.

5. The backlight compensation method according to claim 1, wherein: The brightness area is the ratio of a white screen area in the backlight unit to the panel area of ​​the backlight unit.

6. A display, characterized in that: Having a gamma value, the display comprises: A backlight unit having a first display brightness value, a brightness area and a corresponding brightness adjustment ratio, wherein the backlight unit has a plurality of regions, and each region has a regional peak brightness value; and a driving unit coupled to the backlight unit and calculating the first display brightness value according to a product of a plurality of regional peak brightness values ​​and the brightness adjustment ratio; Each of the first display brightness values ​​corresponds to each area in the backlight unit.

7. The display according to claim 6, characterized in that The backlight unit further includes: a black screen grayscale measurement value, a white screen grayscale measurement value, and a second display brightness value, and the second display brightness value is obtained by normalizing the difference between the black screen grayscale measurement value and the white screen grayscale measurement value as a base and taking the gamma value as an exponent.

8. The display according to claim 6, characterized in that The gamma value is 2.

2.

9. The display according to claim 6, characterized in that The brightness area has an inversely proportional relationship to the brightness adjustment ratio.

10. The display according to claim 6, characterized in that The brightness area is the ratio of a white screen area in the backlight unit to the panel area of ​​the backlight unit.

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