Gamma voltage adjusting method, gamma voltage adjusting circuit and display device

Abstract

The invention discloses a gamma voltage adjusting method, a gamma voltage adjusting circuit and a display device.The gamma voltage adjusting method is used for adjusting the gamma voltage of a display panel, and the gamma voltage adjusting method comprises the steps that the ambient light intensity is obtained, at least three continuous light areas are divided based on the ambient light intensity, and the light areas are used for adjusting the gamma voltage of the display panel; each light area corresponds to a gamma curve voltage lookup table; judging a light area where the current ambient light intensity is located; and according to the gamma curve voltage lookup table corresponding to the light area, selecting a corresponding gamma curve and a gray-scale voltage value, and outputting the gamma curve and the gray-scale voltage value to a display panel. According to the method, the ambient light intensity is acquired in real time, the corresponding gamma voltage curve and the corresponding gray-scale voltage are provided according to different ambient light intensities, the defect that a fixed Gamma (gamma) curve cannot adapt to dynamic ambient light is overcome, and the display brightness and the display effect are improved.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a method for adjusting gamma voltage, a gamma voltage adjustment circuit, and a display device. Background Technology

[0002] In OLED / LCD displays, gamma correction is a crucial step, used to compensate for the nonlinear characteristics of display devices (such as the electro-optical response curve of liquid crystals) and the nonlinearity of human vision. Traditional gamma correction uses a fixed curve (e.g., γ=2.2), but in practical applications, changes in ambient light significantly affect the human eye's perception of image contrast. For example, in strong light, details in dark areas are lost, while in weak light, details in bright areas are overexposed. When gamma is set to γ=2.2 (standard value), under normal lighting conditions (200 lux), details in both dark areas (green frame) and bright areas (cyan frame) are clearly visible. In strong light conditions (1500 lux), the ambient light intensity is much higher than the display brightness, causing details in dark areas (red frame) to be "submerged" by the strong ambient light, while details in bright areas (cyan frame) are overexposed, resulting in a compression of the visual perception range (reduced dynamic range). In weak light conditions (10 lux), details in dark areas (red frame) disappear, and localized glare occurs in bright areas (cyan frame).

[0003] Currently, commonly used ambient light sensors are only used to adjust screen brightness (such as automatic brightness adjustment on mobile phones) and are not linked to gamma correction. Fixed gamma correction schemes include fixed multi-mode switching (such as "reading mode" preset γ=2.4), fixed γ value correction (such as sRGB γ=2.2), and lookup table (LUT) to store preset curves. Content analysis-based gamma schemes require an image recognition module, but cannot respond to environmental changes in real time. Summary of the Invention

[0004] The purpose of this application is to provide a method, circuit, and device for adjusting gamma voltage to improve display performance in real time in response to environmental changes.

[0005] This application discloses a method for adjusting gamma voltage, used to adjust the gamma voltage of a display panel. The method for adjusting gamma voltage includes: The ambient light intensity is obtained, and the ambient light intensity is divided into at least three continuous light regions, with each light region corresponding to a gamma curve voltage lookup table. Determine the area of ​​light where the current ambient light intensity is located; and The corresponding gamma curve and grayscale voltage value are selected from the gamma curve voltage lookup table corresponding to the light area and output to the display panel.

[0006] Optionally, the step of obtaining ambient light intensity by dividing the ambient light intensity into at least three continuous light regions, each light region corresponding to a gamma curve voltage lookup table, includes: The ambient light intensity is obtained and divided into three continuous light regions: a strong light region, a transition region, and a weak light region based on the magnitude of the ambient light intensity. The strong light region corresponds to the first gamma curve voltage lookup table, and the weak light region corresponds to the third gamma curve voltage lookup table. Based on the first gamma curve value in the first gamma curve voltage lookup table corresponding to the strong light region, the third gamma curve value in the third gamma curve voltage lookup table corresponding to the weak light region, and the first preset formula, the second gamma curve value in the second gamma curve voltage lookup table corresponding to the transition region is calculated to obtain the second gamma curve voltage lookup table corresponding to the transition region.

[0007] Optionally, the first gamma curve voltage lookup table corresponding to the strong light area includes a first gamma curve value and a corresponding grayscale voltage value. The difference between two adjacent grayscale voltage values ​​in the first gamma curve voltage lookup table is 1.2 to 1.5 times the difference between two adjacent pre-stored original grayscale voltage values. The third gamma curve voltage lookup table corresponding to the weak light area includes a third gamma curve value and a corresponding grayscale voltage value. The difference between two adjacent grayscale voltage values ​​in the third gamma curve voltage lookup table is 0.6 to 0.8 times the difference between two adjacent pre-stored original grayscale voltage values.

[0008] Optionally, the first preset formula is as follows: ; The value of the second gamma curve. These are the weighting coefficients. The first gamma value in the high-light region. This represents the third gamma curve value in the low-light region. The weighting coefficient α is obtained by linear mapping of ambient light intensity:

[0009] Given the current ambient light intensity, The light intensity at the boundary between the low-light region and the transition region. The light intensity at the boundary between the strong light area and the transition area.

[0010] Optionally, the voltage calculation for the second gamma curve voltage lookup table is as follows: ; Where Voutput(n) is the output voltage of gray level n, V 强光 (n), V弱光 (n) represents the voltage corresponding to the strong light / weak light curve, and α is the weighting coefficient in the first preset formula.

[0011] Optionally, the three regions are a strong light region, a transition region, and a weak light region. The light intensity of the strong light region is greater than 1000 Lux, the light intensity of the transition region is greater than or equal to 500 Lux and less than or equal to 1000 Lux, and the light intensity of the weak light region is less than 500 Lux.

[0012] Optionally, the display panel includes multiple columns of sub-pixels of different colors. For sub-pixels of different colors, different gamma voltage compensation values ​​are set under the same light area. Under different light areas, sub-pixels of the same color are set with different gamma voltage compensation values. After the step of selecting the corresponding gamma voltage to be output to the display panel according to the gamma curve voltage lookup table corresponding to the light area, the method further includes: The color of the current column sub-pixel is detected and determined. Based on the color of the current column sub-pixel and the area where the current ambient light intensity is located, the corresponding gamma voltage compensation value is selected to compensate the gamma voltage of the input display panel.

[0013] This application discloses a gamma voltage adjustment circuit that adjusts the grayscale voltage value input to the display panel using any of the adjustment methods described above. The gamma voltage adjustment circuit includes an ambient light sensing module, a light intensity partitioning module, a gamma curve voltage lookup table, and a grayscale voltage output module. The ambient light sensing module acquires the ambient light intensity, the light intensity partitioning module divides the light region based on the ambient light intensity acquired by the ambient light sensing module, the gamma curve voltage lookup table is set according to the light region, and the grayscale voltage output module selects the corresponding gamma curve and grayscale voltage value according to the gamma curve voltage lookup table corresponding to the light region and outputs it to the display panel.

[0014] Optionally, the gamma voltage regulation circuit further includes an analog-to-digital conversion module and a gamma curve calculation module. One end of the analog-to-digital conversion module is connected to the ambient light sensing module, and the other end is connected to the light intensity partitioning module. The analog-to-digital conversion module converts the ambient light intensity obtained by the ambient light sensing module into a digital signal and outputs it to the light intensity partitioning module. The gamma curve calculation module calculates the second gamma curve value in the second gamma curve voltage lookup table corresponding to the transition zone based on the first gamma curve value in the first gamma curve voltage lookup table corresponding to the strong light zone, the third gamma curve value in the third gamma curve voltage lookup table corresponding to the weak light zone, and a first preset formula, so as to obtain the second gamma curve voltage lookup table corresponding to the transition zone.

[0015] This application also discloses a display device, which includes a display panel and a gamma voltage adjustment circuit as described above, wherein the gamma voltage adjustment circuit is used to adjust the grayscale voltage value of the display panel.

[0016] Compared to methods that adjust data voltage to improve display brightness, this application obtains ambient light intensity and divides the ambient light intensity into at least three continuous light regions, each corresponding to a gamma curve voltage lookup table; determines the light region where the current ambient light intensity is located; and selects the corresponding gamma curve and grayscale voltage value according to the gamma curve voltage lookup table corresponding to the light region and outputs it to the display panel. This achieves precise adaptive adaptation of the gamma characteristic to ambient light, improves the defect that a fixed gamma (γ) curve cannot adapt to dynamic ambient light, and enhances display brightness and display effect. Attached Figure Description

[0017] The accompanying drawings, which form part of the specification, are used to provide a further understanding of the embodiments of this application and illustrate the implementation methods of this application, together with the textual description, to explain the principles of this application. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any creative effort. In the drawings: Figure 1 This is a schematic flowchart of the gamma voltage adjustment method according to the first embodiment of this application; Figure 2 This is a schematic flowchart of the gamma voltage adjustment method according to the second embodiment of this application; Figure 3 This is a graph showing the relationship between ambient light intensity and contrast perception according to the second embodiment of this application; Figure 4 This is a schematic diagram of the optimized gamma voltage curve of the third embodiment of this application; Figure 5 This is a schematic diagram illustrating the mapping relationship between ambient light intensity and weighting coefficients in the third embodiment of this application; Figure 6 This is a schematic flowchart of the gamma voltage adjustment method according to the fourth embodiment of this application; Figure 7 This is a schematic diagram of the gamma voltage regulation circuit and display panel according to the fifth embodiment of this application; Figure 8 This is a schematic diagram of the gamma voltage regulation circuit and display panel according to the sixth embodiment of this application; Figure 9 This is a schematic diagram of the structure of the display device according to the seventh embodiment of this application.

[0018] Among them, 100 is the gamma voltage adjustment circuit; 110 is the ambient light sensing module; 120 is the light intensity zoning module; 130 is the gamma curve voltage lookup table; 140 is the grayscale voltage output module; 141 is the filtering unit; 142 is the voltage divider unit; 150 is the analog-to-digital conversion module; 160 is the gamma curve calculation module; 200 is the display panel; and 300 is the display device. Detailed Implementation

[0019] It should be understood that the terminology, specific structural and functional details used herein are merely for describing particular embodiments and are representative. However, this application may be implemented in many alternative forms and should not be construed as being limited to the embodiments set forth herein.

[0020] The present application will now be described in detail with reference to the accompanying drawings and optional embodiments.

[0021] refer to Figure 1 As shown, in the first embodiment of this application, a method for adjusting gamma voltage is disclosed for adjusting the gamma voltage of a display panel. The method for adjusting gamma voltage includes: S1: Obtain the ambient light intensity. Based on the magnitude of the ambient light intensity, divide it into at least three continuous light regions. Each light region corresponds to a gamma curve voltage lookup table. S2: Determine the area of ​​light where the current ambient light intensity is located; and S3: Select the corresponding gamma curve and grayscale voltage value according to the gamma curve voltage lookup table corresponding to the light area and output it to the display panel.

[0022] To address the shortcomings of fixed Gamma (γ) curves in adapting to dynamic ambient light (such as loss of detail in dark areas under strong light and overexposure in bright areas under weak light), this application acquires ambient light intensity and divides the light into at least three continuous light regions based on the magnitude of the ambient light intensity. Each light region corresponds to a gamma curve voltage lookup table. The application detects and determines the light region where the current ambient light intensity is located in real time. Based on the gamma curve voltage lookup table corresponding to the light region, the application selects the corresponding gamma curve and grayscale voltage value and outputs it to the display panel. By selecting different gamma curves and grayscale voltage values ​​based on the ambient light intensity, the application achieves precise adaptive adaptation of the Gamma characteristic to ambient light.

[0023] refer to Figure 2 As shown, the second embodiment of this application is a further refinement and improvement of the first embodiment described above. Step S1 includes: S11: Obtain ambient light intensity and divide the ambient light intensity into three continuous light regions: strong light region, transition region and weak light region. The strong light region corresponds to the first gamma curve voltage lookup table and the weak light region corresponds to the third gamma curve voltage lookup table. S12: Based on the first gamma curve value in the first gamma curve voltage lookup table corresponding to the strong light region, the third gamma curve value in the third gamma curve voltage lookup table corresponding to the weak light region, and the first preset formula, the second gamma curve value in the second gamma curve voltage lookup table corresponding to the transition region is calculated to obtain the second gamma curve voltage lookup table corresponding to the transition region.

[0024] The first preset formula is as follows: ; The value of the second gamma curve. These are the weighting coefficients. The first gamma value in the high-light region. This is the third gamma curve value in the low-light region. After the ambient light sensor collects the new light intensity Lenv value, the new gamma curve will be loaded into the corresponding lookup table (LUT) after a very short processing time (<1ms). All subsequent pixel data will be converted in real time according to this new curve to generate the corresponding new data voltage.

[0025] The weighting coefficient α is obtained by linear mapping of ambient light intensity:

[0026] Given the current ambient light intensity, The light intensity at the boundary between the low-light region and the transition region. The light intensity at the boundary between the strong light area and the transition area.

[0027] The voltage calculation for the second gamma curve voltage lookup table is as follows: ; Where Voutput(n) is the output voltage of gray level n, V 强光 (n), V 弱光 (n) represents the voltage corresponding to the strong light / weak light curve, and α is the weighting coefficient in the first preset formula.

[0028] Generally, the three areas are divided into a strong light area, a transition area, and a weak light area. The light intensity of the strong light area is greater than 1000 Lux, the light intensity of the transition area is greater than or equal to 500 Lux and less than or equal to 1000 Lux, and the light intensity of the weak light area is less than 500 Lux. Typically, the display panel will have two pre-stored reference gamma curves (strong light curve γ=1.6~1.8, weak light curve γ=2.4~2.6). The gamma curve value in the transition area is not preset, but is generated by a weighted mixing algorithm to produce a smooth intermediate gamma curve, which is the gamma curve value corresponding to the transition area.

[0029] In the specific adjustment process, taking an 8-bit display (resolution 1920×1080, suitable for OLED, LCD, Mini / MicroLED) as an example, the implementation can be divided into input light intensity, determining the light region interval, calculating weights, and output gamma curve values, as follows: Step 1: Input light intensity Ambient light intensity is acquired using an ambient light sensor (ALS) commonly used in mobile devices, which collects ambient light intensity (Lenv) in real time (unit: lux). The analog signal is then converted to a digital signal (range: 0~4080, corresponding to 0~4000 lux) via a 12-bit ADC converter. The sampling rate must be at least 10Hz (to satisfy the persistence of vision in the human eye and avoid frequent adjustments). Step 2: Determine the light region / section Light intensity range determination is based on pre-stored ambient light thresholds, and the range division is determined through human visual experiments to conform to human visual characteristics (e.g., Figure 3 As shown), the Lenv light intensities are divided into three intervals: Low-light areas: Lenv < 500 Lux (e.g., under a bedroom desk lamp, < 500 Lux); Transition zone: 500 Lux ≤ Lenv ≤ 1000 Lux (e.g., near indoor windows, 500~1000 Lux); Strong light areas: Lenv > 1000 Lux (e.g., outdoor sunny day, > 1000 Lux).

[0030] This step can be implemented using a comparator circuit in an FPGA to determine the threshold.

[0031] Step 3: Calculate the weights Weight coefficient calculation (transition region only): The algorithm logic is as follows: When Lenv is in the transition region (500~1000 Lux), the weight coefficients (range: 0~1) are calculated using the linear mapping formula and used for subsequent γ curve fitting.

[0032] For example: When the light intensity value Lenv = 500 lux (lower limit of the transition zone): α = 0 (fully call the weak light curve); When the light intensity value Lenv = 750 lux (midpoint of the transition zone): α = 0.5 (50% high light curve + 50% low light curve); When the light intensity value Lenv = 1000 lux (upper limit of the transition zone): α = 1 (fully call up the strong light curve).

[0033] This step can be achieved through linear calculations using a multiplier and subtractor circuit in an FPGA.

[0034] Step 4: Output the gamma curve The core logic of γ curve generation and output is as follows: based on the light intensity range, two pre-stored reference γ curves (strong light curve γ=1.7, weak light curve γ=2.5) are called or mixed to generate the corresponding gray level output voltage, which is finally transmitted to the source driver of the display panel.

[0035] Generally, in practical work, 10 key grayscale voltage values ​​of two reference curves are pre-stored in a lookup table (LUT) (Table 1), covering the full grayscale range (0~255) of the 8-bit panel. The selection of key grayscale points is based on the slope change of the γ curve (large slope for low grayscale, small slope for high grayscale) to ensure curve accuracy.

[0036]

[0037] Table 1 Key grayscale voltages for strong light / weak light reference curves (maximum output voltage = 5V) Curve adjustment (low light area / high light area): Low light area (Lenv<500lux): The voltage value of the low light curve is read directly from the LUT (e.g., 0.3V for gray level 32) and output to the source driver of the display panel; High-intensity area (Lenv>1000lux): The voltage value of the high-intensity curve is read directly from the LUT (e.g., 0.4V for grayscale level 32) and output to the source driver of the display panel.

[0038] Curve blending (transition zone): When Lenv is in the transition region, the voltage value of the intermediate γ curve is generated by a weighted average algorithm, as shown in the following formula:

[0039] Where Voutput(n) is the output voltage of gray level n, Vstrong light(n) and Vweak light(n) are the corresponding voltages of the strong light / weak light curves, and α is the weighting coefficient calculated in step 3. An example is shown below (Lenv=750 lux, α=0.5): Output voltage for grayscale level 32: 0.5 × 0.4V + 0.5 × 0.3V = 0.35V; Output voltage for grayscale level 64: 0.5 × 1.0V + 0.5 × 0.8V = 0.9V; The output voltage for 128 gray levels is: 0.5 × 2.7V + 0.5 × 2.3V = 2.5V.

[0040] The intermediate γ curve generated by the above calculation is close to the strong light curve in the low grayscale (dark areas) (enhancing details) and close to the weak light curve in the high grayscale (bright areas) (avoiding overexposure), and there is no visual jump in the transition area.

[0041] Voltage output: The generated 256-level grayscale voltage (interpolated by LUT to fill in the intermediate values ​​between 10 key gray levels) is transmitted to the source driver to drive the OLED / LCD panel to display the image.

[0042] In addition, the weighting coefficient α is defined as follows: When the light intensity value Lenv = 500 Lux, α = 0, and the output curve is a completely weak light curve; When the light intensity value Lenv = 1000 Lux, α = 1, the output curve is entirely a high-intensity curve; Between 500 and 1000 Lux, α changes linearly from 0 to 1, for example, α=0.4 or α=0.6, the output curves are as follows: α=0.4: 40% high light curve + 60% low light curve α=0.6: 60% high light curve + 40% low light curve Given a strong light curve γ=1.7, a weak light curve γ=2.5, and a light intensity value Lenv=700Lux, calculate α: α = (700 - 500) / (1000 - 500) = 0.4 Therefore, the output curve is: Voutput=0.4V 强光 +(1 0.4)V 弱光 =0.4V 强光 +0.6V 弱光 That is: 40% high light curve + 60% low light curve.

[0043] As described above, as long as the ambient light intensity Lenv is between 500 and 1000 Lux, the weighting coefficient α will continuously change between 0 and 1, thus allowing for any proportion of mixing, including 40% and 60%.

[0044] As a third embodiment of this application, it is a further refinement and improvement of any of the above embodiments. The first gamma curve voltage lookup table corresponding to the strong light area includes a first gamma curve value and a corresponding grayscale voltage value. The difference between two adjacent grayscale voltage values ​​in the first gamma curve voltage lookup table is 1.2 to 1.5 times the difference between two adjacent pre-stored original grayscale voltage values. The third gamma curve voltage lookup table corresponding to the weak light area includes a third gamma curve value and a corresponding grayscale voltage value. The difference between two adjacent grayscale voltage values ​​in the third gamma curve voltage lookup table is 0.6 to 0.8 times the difference between two adjacent pre-stored original grayscale voltage values.

[0045] In this embodiment, the ambient light intensity (Lenv) is first divided into three intervals using a threshold judgment algorithm: Areas with strong light: Lenv > 1000 Lux (such as under outdoor sunlight); Transition zone: 500≤Lenv≤1000Lux (e.g., near indoor windows); Low-light areas: Lenv < 500 Lux (such as under a bedroom lamp).

[0046] The zoning thresholds are determined through human visual experiments to establish the relationship between ambient light and contrast perception, ensuring that the zoning aligns with human visual characteristics. For example, a strong light zone threshold of 1000 Lux corresponds to typical lighting conditions on a sunny outdoor day; a weak light zone threshold of 500 Lux corresponds to comfortable lighting conditions in an indoor office setting; a low ambient light zone (<500 Lux) represents the area where the human eye's contrast discrimination ability is weak in darkness, but increases rapidly with increasing ambient light; a comfortable working zone (500-1000 Lux) represents the ideal visual working environment where contrast discrimination is optimal, with the human eye's perception remaining stable within the range of 0.5-0.9; and a high ambient light zone (>1000 Lux) represents the area where excessively strong ambient light causes glare, slightly reducing contrast perception, and the perception ability approaches saturation (close to 0.9). refer to Figure 4 As shown, this embodiment includes a baseline curve, i.e., the traditional curve in the figure. Two optimized γ curves are pre-stored in the baseline curve library: High-light curve (γ=1.6~1.8): Designed for high-light environments. In high-light environments, the human eye's sensitivity to dark details decreases → it is necessary to increase the dark area voltage interval to reduce the γ value (e.g., the voltage difference between gray levels 0~64 is increased from 0.1V to 0.15V), thereby improving the contrast of dark details and increasing the visibility of dark details by 40%. Low-light curve (γ=2.4~2.6): Designed for low-light environments. In low-light environments, the human eye is more sensitive to details in bright areas. It is necessary to compress the voltage interval of the gray level in bright areas to increase the Gamma value (e.g., the voltage difference between gray levels 192–255 is reduced from 0.2V to 0.12V) to avoid overexposure of bright areas. The loss rate of details in bright areas is reduced from 25% to 5%.

[0047] Both curves are optimized and stored as 10-point LUTs (lookup tables) (e.g., grayscale levels 0, 32, 64, 96, 128, 160, 192, 224, 240, 255). Assuming the optimized strong light reference γ=1.7 and weak light reference γ=2.5, the optimized γ curves and the optimized voltages for each key grayscale level are shown in Table 2 (maximum output voltage set to 5V).

[0048] Table 2 shows the voltage corresponding to the key gray levels of the optimized γ-ray reference curves for strong and weak light. Transition Zone Blending Algorithm: When the ambient light is in the transition zone (500~1000 Lux), the curve fitting engine generates an intermediate Gamma curve using a weighted summation formula.

[0049] The weighting coefficient α is obtained by linear mapping of ambient light intensity:

[0050] For example, when the ambient light is 750 lux, α = 0.5, and the output Gamma curve is "50% strong light curve + 50% weak light curve". Using this method, the brightness output is closer to the characteristics of the strong light curve (γ = 1.7) in the low grayscale region (dark areas) and closer to the characteristics of the weak light curve (γ = 2.5) in the high grayscale region (bright areas). The response changes in each grayscale region are shown in Table 1, thus achieving a smooth transition from strong light to weak light (γ value changes linearly from 1.7 to 2.5), avoiding visual abrupt changes. Therefore, when the ambient light continuously changes from 500 to 1000 Lux: α continuously changes from 0 to 1 (e.g., ...). Figure 5 As shown in the figure, the brightness of each grayscale point transitions smoothly, and the human eye perceives the overall contrast as being adjusted "linearly".

[0051] refer to Figure 6As shown, the fourth embodiment of this application is a further refinement and improvement of any of the above embodiments. The display panel includes multiple columns of sub-pixels of different colors. For sub-pixels of different colors, different gamma voltage compensation values ​​are set under the same light area. Under different light areas, sub-pixels of the same color are set with different gamma voltage compensation values. After the step of selecting the corresponding gamma voltage according to the gamma curve voltage lookup table corresponding to the light area and outputting it to the display panel, the method further includes: S4: Detect and determine the color of the current column sub-pixel, select the corresponding gamma voltage compensation value based on the color of the current column sub-pixel and the area where the current ambient light intensity is located, and compensate the gamma voltage of the input value display panel.

[0052] In this example, different color pixels within the same area are adjusted using different Gamma curves. Under the same light area, different gamma voltage compensation values ​​are set. Under different light areas, sub-pixels of the same color are set with different gamma voltage compensation values, further achieving efficient correction to improve the display effect of the display panel.

[0053] refer to Figure 7 As shown, as the fifth embodiment of this application, a gamma voltage adjustment circuit 100 is disclosed. It adjusts the grayscale voltage value input to the display panel using the adjustment method described in any of the above embodiments. The gamma voltage adjustment circuit includes an ambient light sensing module 110, a light intensity partitioning module 120, a gamma curve voltage lookup table 130, and a grayscale voltage output module 140. The ambient light sensing module 110 acquires the ambient light intensity. The light intensity partitioning module 120 divides the light region based on the ambient light intensity acquired by the ambient light sensing module 110. The gamma curve voltage lookup table 130 is set according to the light region. The grayscale voltage output module 140 selects the corresponding gamma curve and grayscale voltage value according to the gamma curve voltage lookup table 130 corresponding to the light region and outputs it to the display panel.

[0054] In this embodiment, the ambient light sensing module 110 mainly consists of an ambient light sensor that collects the ambient light intensity Lenv (unit: Lux) in real time. The light intensity partitioning module 120 divides the ambient light intensity Lenv into at least three regions based on a threshold judgment algorithm. Different regions correspond to different gamma curve voltage lookup tables 130. After determining the region where the current ambient light intensity is located, the grayscale voltage output module 140 selects the corresponding gamma curve and grayscale voltage value according to the gamma curve voltage lookup table 130 corresponding to the light region and outputs it to the display panel. Through the circuit composed of the gamma curve voltage lookup table and the corresponding module, no software calculation is required, ensuring real-time performance and avoiding the increase in CPU load and impact on refresh rate caused by software dynamic Gamma.

[0055] refer to Figure 8 As shown, the sixth embodiment of this application is a further refinement of the fifth embodiment described above. The gamma voltage adjustment circuit 100 further includes an analog-to-digital conversion module 150 and a gamma curve calculation module 160. One end of the analog-to-digital conversion module 150 is connected to the ambient light sensing module 110, and the other end is connected to the light intensity partitioning module 120. The analog-to-digital conversion module 150 converts the ambient light intensity obtained by the ambient light sensing module 110 into a digital signal and outputs it to the light intensity partitioning module. The gamma curve calculation module 160 calculates the second gamma curve value in the second gamma curve voltage lookup table corresponding to the transition zone based on the first gamma curve value in the first gamma curve voltage lookup table corresponding to the strong light zone, the third gamma curve value in the third gamma curve voltage lookup table corresponding to the weak light zone, and the first preset formula, so as to obtain the second gamma curve voltage lookup table corresponding to the transition zone.

[0056] Typically, the gamma curve value of a strong light curve ranges from γ=1.6 to 1.8. Designed for strong light environments, the human eye's sensitivity to dark details decreases in strong light conditions → it is necessary to increase the dark voltage interval to reduce the γ value (e.g., increasing the voltage difference between gray levels 0-64 from 0.1V to 0.15V). That is, the difference between two adjacent gray level voltage values ​​in the first gamma curve voltage lookup table is 1.2 to 1.5 times the difference between two adjacent pre-stored original gray level voltage values, improving the contrast of dark details and increasing the visibility of dark details by 40%. Low-light curve (γ=2.4~2.6): Designed for low-light environments. In low-light environments, the human eye is more sensitive to details in bright areas. It is necessary to compress the voltage interval of gray levels in bright areas to increase the Gamma value (e.g., the voltage difference between gray levels 192–255 is reduced from 0.2V to 0.12V). That is, the difference between two adjacent gray level voltage values ​​in the voltage lookup table of the third gamma curve is 0.6 to 0.8 times the difference between two adjacent pre-stored original gray level voltage values ​​to avoid overexposure in bright areas. The loss rate of details in bright areas is reduced from 25% to 5%.

[0057] Transition Zone Blending Algorithm: When the ambient light is in the transition zone (500~1000 Lux), the curve blending engine generates an intermediate Gamma curve using a weighted summation formula.

[0058] The weighting coefficient α is obtained by linear mapping of ambient light intensity:

[0059] For example, when the ambient light is 750 lux, α = 0.5, and the output Gamma curve is "50% strong light curve + 50% weak light curve". Using this method, the brightness output is closer to the characteristics of the strong light curve (γ = 1.7) in the low grayscale region (dark areas) and closer to the characteristics of the weak light curve (γ = 2.5) in the high grayscale region (bright areas). The response changes in each grayscale region are shown in Table 2, thus achieving a smooth transition from strong light to weak light (γ value changes linearly from 1.7 to 2.5), avoiding visual abrupt changes. Therefore, when the ambient light continuously changes from 500 to 1000 Lux: α continuously changes from 0 to 1 (e.g., ... Figure 5 As shown in the figure, the brightness of each grayscale point transitions smoothly, and the human eye perceives the overall contrast as being adjusted "linearly".

[0060] Referring to Figure 9, as a seventh embodiment of this application, a display device 300 is disclosed. The display device 300 includes a display panel 200 and a gamma voltage adjustment circuit 100 as described above. The gamma voltage adjustment circuit 100 is used to adjust the grayscale voltage value of the display panel 200.

[0061] It should be noted that the inventive concept of this application can form many embodiments, but due to the limited space of the application documents, they cannot all be listed. Therefore, without conflict, the embodiments described above or the technical features can be arbitrarily combined to form new embodiments. After the embodiments or technical features are combined, the original technical effect will be enhanced.

[0062] The above description, in conjunction with specific optional embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of this application, and all such modifications or substitutions should be considered within the scope of protection of this application.

Claims

1. A method for adjusting gamma voltage, used to adjust the gamma voltage of a display panel, characterized in that, The method for adjusting the gamma voltage includes: The ambient light intensity is obtained, and the ambient light intensity is divided into at least three continuous light regions, with each light region corresponding to a gamma curve voltage lookup table. Determine the area of ​​light where the current ambient light intensity is located; and The corresponding gamma curve and grayscale voltage value are selected from the gamma curve voltage lookup table corresponding to the light area and output to the display panel.

2. The method for adjusting gamma voltage as described in claim 1, characterized in that, The step of obtaining ambient light intensity, which involves dividing the ambient light intensity into at least three continuous light regions based on the magnitude of the intensity, with each light region corresponding to a gamma curve voltage lookup table, includes: The ambient light intensity is obtained and divided into three continuous light regions: a strong light region, a transition region, and a weak light region based on the magnitude of the ambient light intensity. The strong light region corresponds to the first gamma curve voltage lookup table, and the weak light region corresponds to the third gamma curve voltage lookup table. Based on the first gamma curve value in the first gamma curve voltage lookup table corresponding to the strong light region, the third gamma curve value in the third gamma curve voltage lookup table corresponding to the weak light region, and the first preset formula, the second gamma curve value in the second gamma curve voltage lookup table corresponding to the transition region is calculated to obtain the second gamma curve voltage lookup table corresponding to the transition region.

3. The method for adjusting gamma voltage as described in claim 2, characterized in that, The first gamma curve voltage lookup table corresponding to the strong light area includes a first gamma curve value and a corresponding grayscale voltage value. The difference between two adjacent grayscale voltage values ​​in the first gamma curve voltage lookup table is 1.2 to 1.5 times the difference between two adjacent pre-stored original grayscale voltage values. The third gamma curve voltage lookup table corresponding to the weak light area includes a third gamma curve value and a corresponding grayscale voltage value. The difference between two adjacent grayscale voltage values ​​in the third gamma curve voltage lookup table is 0.6 to 0.8 times the difference between two adjacent pre-stored original grayscale voltage values.

4. The method for adjusting the gamma voltage as described in claim 2, characterized in that, The first preset formula is as follows: ； The value of the second gamma curve. These are the weighting coefficients. The first gamma value in the high-light region. This represents the third gamma curve value in the low-light region. The weighting coefficient α is obtained by linear mapping of ambient light intensity: Given the current ambient light intensity, The light intensity at the boundary between the low-light region and the transition region. The light intensity at the boundary between the strong light area and the transition area.

5. The method for adjusting gamma voltage as described in claim 4, characterized in that, The voltage calculation for the second gamma curve voltage lookup table is as follows: ； Where Voutput(n) is the output voltage of gray level n, V 强光 (n), V 弱光 (n) represents the voltage corresponding to the strong light / weak light curve, and α is the weighting coefficient in the first preset formula.

6. The method for adjusting the gamma voltage as described in any one of claims 1-5, characterized in that, The three regions are a strong light region, a transition region, and a weak light region. The light intensity of the strong light region is greater than 1000 Lux, the light intensity of the transition region is greater than or equal to 500 Lux and less than or equal to 1000 Lux, and the light intensity of the weak light region is less than 500 Lux.

7. The method for adjusting gamma voltage as described in claim 1, characterized in that, The display panel includes multiple columns of sub-pixels of different colors. For sub-pixels of different colors, different gamma voltage compensation values ​​are set under the same light area. Under different light areas, sub-pixels of the same color are set with different gamma voltage compensation values. After the step of selecting the corresponding gamma voltage to be output to the display panel according to the gamma curve voltage lookup table corresponding to the light area, the method further includes: The color of the current column sub-pixel is detected and determined. Based on the color of the current column sub-pixel and the area where the current ambient light intensity is located, the corresponding gamma voltage compensation value is selected to compensate the gamma voltage of the input value display panel.

8. A gamma voltage regulation circuit, characterized in that, The grayscale voltage value input to the display panel is adjusted using the adjustment method described in any one of claims 1-7. The gamma voltage adjustment circuit includes an ambient light sensing module, a light intensity partitioning module, a gamma curve voltage lookup table, and a grayscale voltage output module. The ambient light sensing module acquires the ambient light intensity. The light intensity partitioning module divides the light region based on the ambient light intensity acquired by the ambient light sensing module. The gamma curve voltage lookup table is set according to the light region. The grayscale voltage output module selects the corresponding gamma curve and grayscale voltage value according to the gamma curve voltage lookup table corresponding to the light region and outputs it to the display panel.

9. The gamma voltage regulation circuit as described in claim 8, characterized in that, The gamma voltage regulation circuit further includes an analog-to-digital conversion module and a gamma curve calculation module. One end of the analog-to-digital conversion module is connected to the ambient light sensing module, and the other end is connected to the light intensity partitioning module. The analog-to-digital conversion module converts the ambient light intensity obtained by the ambient light sensing module into a digital signal and outputs it to the light intensity partitioning module. The gamma curve calculation module calculates the second gamma curve value in the second gamma curve voltage lookup table corresponding to the transition zone based on the first gamma curve value in the first gamma curve voltage lookup table corresponding to the strong light zone, the third gamma curve value in the third gamma curve voltage lookup table corresponding to the weak light zone, and the first preset formula, so as to obtain the second gamma curve voltage lookup table corresponding to the transition zone.

10. A display device, characterized in that, The display device includes a display panel and a gamma voltage adjustment circuit as described in claims 8-9, wherein the gamma voltage adjustment circuit is used to adjust the grayscale voltage value of the display panel.

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