Color calibration method for display screens, display devices

Abstract

This invention provides a color tone correction method and display device for a display screen. The method includes: driving the display screen to operate based on a first color tone curve; acquiring the current ambient temperature; detecting whether the current ambient temperature is within a first preset temperature range; when the ambient temperature is within the first preset temperature range, switching the first color tone curve to a second color tone curve pre-loaded into a temporary storage subunit of the driving unit, and driving the display screen to operate based on the second color tone curve, wherein the second color tone curve is a color tone curve pre-compensated to correspond to the first preset temperature range. When the ambient temperature is detected to be within the first preset temperature range, the first color tone curve is quickly switched to the second color tone curve, effectively avoiding phenomena such as brightness attenuation, color temperature and hue shift, and white balance deviation. Due to the fast switching speed, the switching process does not cause significant changes to the display screen, resulting in a better user experience.

Description

Technical Field

[0001] This invention relates to the field of display screen calibration technology, and in particular to a color tone correction method and display device for a display screen. Background Technology

[0002] With the continuous development of OLED (Organic Light-Emitting Diode) technology, OLED screens have been widely used in automobiles. In order to achieve better display functions, the brightness, color temperature, hue, white balance and other parameters of the display screen need to be adjusted before leaving the factory, and these adjustments are generally carried out at room temperature.

[0003] However, the operating environment of vehicles is quite complex, and they may face high or low temperature environments. Once the display screen is in extremely harsh environmental conditions, such as in an environment with a high temperature of 85℃ or a low temperature of -40℃, the brightness, color temperature, hue, white balance and other parameters of the display screen that have been pre-calibrated at room temperature will deviate, resulting in phenomena such as brightness attenuation and color temperature and hue shift.

[0004] To prevent the aforementioned problems from occurring in harsh environments, the Gamma curve of the display needs to be compensated to address the issues of brightness, color temperature, and hue shifts at different temperatures, thus adapting to display requirements under varying conditions. Summary of the Invention

[0005] Therefore, it is necessary to provide a color calibration method and display device for a display screen to address the aforementioned technical problems.

[0006] A display device includes a driving unit, the driving unit having a temporary storage subunit;

[0007] The driving unit is configured to drive the display screen based on a first hue curve.

[0008] The driving unit is further configured to acquire the current ambient temperature, detect whether the current ambient temperature is within a first preset temperature range, and when the ambient temperature is within the first preset temperature range, switch the first color tone curve to a second color tone curve pre-loaded into the temporary storage subunit; drive the display screen to work based on the switched second color tone curve; wherein the second color tone curve is a color tone curve pre-compensated to correspond to the first preset temperature range.

[0009] In one embodiment, a storage unit is also included.

[0010] The storage unit is configured to store multiple hue curves that correspond one-to-one with multiple preset temperature ranges;

[0011] The driving unit is also configured to detect whether the current ambient temperature is within a second preset temperature range; when the ambient temperature is within the second preset temperature range, the hue curve corresponding to the ambient temperature is obtained from the storage unit as a third hue curve, the originally loaded hue curve is deleted, and the third hue curve is loaded into the temporary storage subunit.

[0012] In one embodiment, the driving unit is further configured to switch the first hue curve to a second hue curve preloaded to the temporary storage unit when the ambient temperature is within the first preset temperature range for a preset time threshold, and drive the display screen to work based on the second hue.

[0013] A method for color calibration of a display screen, comprising:

[0014] The display screen is driven based on the first color tone curve.

[0015] Get the current ambient temperature;

[0016] Detect whether the current ambient temperature is within the first preset temperature range;

[0017] When the ambient temperature is within the first preset temperature range, the first color tone curve is switched to the second color tone curve pre-loaded into the temporary storage subunit of the driving unit, and the display screen is driven to work based on the second color tone curve; wherein, the second color tone curve is a color tone curve that has been pre-compensated to correspond to the first preset temperature range.

[0018] In one embodiment, it further includes:

[0019] Detect whether the current ambient temperature is within the second preset temperature range;

[0020] When the ambient temperature is within the second preset temperature range, the hue curve corresponding to the ambient temperature is obtained as the third hue curve, the original hue curve loaded in the temporary storage sub-unit is deleted, and the third hue curve is loaded into the temporary storage sub-unit of the driving unit.

[0021] In one embodiment, the step of switching the first color tone curve to a second color tone curve pre-loaded into the driving unit when the ambient temperature is within the first preset temperature range, and driving the display screen based on the second color tone curve, includes:

[0022] When the ambient temperature remains within the first preset temperature range for a preset time threshold, the first color tone curve is switched to the second color tone curve pre-loaded into the temporary storage subunit of the driving unit, and the display screen is driven to work based on the second color tone.

[0023] In one embodiment, it further includes:

[0024] Obtain a reference tone curve;

[0025] Obtain the hue curves to be compensated for multiple preset temperature ranges;

[0026] Each of the to-be-compensated tone curves is compared with the reference tone curve to obtain compensation parameters;

[0027] Each of the aforementioned compensation parameters is used to compensate for each of the aforementioned hue curves to be compensated, thereby obtaining a pre-compensated hue curve corresponding to each of the aforementioned preset temperature ranges.

[0028] In one embodiment, the step of obtaining the hue curves to be compensated corresponding to multiple preset temperature ranges includes:

[0029] Obtain candidate curves for each preset temperature range based on multiple candidate hue parameters;

[0030] The candidate curve for each preset temperature range is compared with the reference hue curve, and the candidate curve that is closest to the reference hue curve in each preset temperature range is determined as the hue curve to be compensated for in the preset temperature range.

[0031] In one embodiment, the step of comparing each of the to be compensated tone curves with the reference tone curve to obtain compensation parameters includes:

[0032] Using the reference hue curve as a reference, each of the hue curves to be compensated is compensated based on the compensation parameters. When the deviation between each of the hue curves to be compensated and the reference hue curve is less than a preset deviation threshold, the compensation parameters are determined.

[0033] In one embodiment, the step of driving the display screen based on the first hue curve is further included before:

[0034] Obtain the first hue curve;

[0035] The preset temperature range that is closest to the temperature corresponding to the first hue curve is obtained as the third preset temperature range;

[0036] Obtain the fourth hue curve corresponding to the third preset temperature range;

[0037] The fourth hue curve is loaded into the temporary storage subunit.

[0038] In the aforementioned color correction method and display device, the temporary storage subunit of the driving unit preloads a second color curve. Thus, when the ambient temperature is detected to be within a first preset temperature range, the driving color curve can be quickly switched from the first color curve to the second color curve. Because this second color curve is adapted to the current ambient temperature, the brightness, color temperature, hue, and white balance of the display screen can all maintain the same level as the brightness, color temperature, hue, and white balance corresponding to the curve in color 2.2. This effectively avoids phenomena such as brightness attenuation, color temperature and hue shift, and white balance deviation. Furthermore, due to the fast switching speed, it is imperceptible to the naked eye, and the switching process does not cause significant changes in the brightness, color temperature, and hue of the display screen. Therefore, the user cannot perceive the switching or the changes in the display screen, resulting in a better user experience. Attached Figure Description

[0039] Figure 1 This is a flowchart illustrating a Gamma correction method for a display screen in one embodiment.

[0040] Figure 2 This is a schematic diagram of the switching of different preset temperature ranges or the temperature range of the loaded Gamma LUT in one embodiment.

[0041] Figure 3 This is a schematic diagram of the structure of a display device in one embodiment;

[0042] Figures 4A to 4C This is a schematic diagram of Gamma curves and color coordinates fitted based on measured data at different temperatures in one embodiment.

[0043] Figures 5A to 5D This is a schematic diagram of the correction process for the Gamma curve in one embodiment. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0045] It should be noted that when an element is referred to as "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0046] Example 1

[0047] In this embodiment, as Figure 1 As shown, a color tone correction method for a display screen is provided, comprising:

[0048] Step 110: Drive the display screen to operate based on the first hue curve.

[0049] In various embodiments, the hue curve is also called the Gamma curve. Therefore, the first hue curve is also called the first Gamma curve. The second hue curve is also called the second Gamma curve, and so on. In this embodiment, the first Gamma curve is the Gamma curve currently driving the display screen. This Gamma curve is also called a Gamma LUT (Look-Up Table), or a Gamma correspondence, or a grayscale brightness correspondence. The Gamma curve refers to the relationship curve between different grayscale levels and brightness. For example, by establishing a coordinate system with grayscale levels of 0-255 as the X-axis and brightness as the Y-axis, and displaying the relationship between grayscale and brightness on the coordinate system, the resulting curve is the Gamma curve.

[0050] The first Gamma curve can be the initial Gamma curve when the display starts up, i.e., the default Gamma curve, or the Gamma curve operating at room temperature, or the Gamma curve operating after switching. In one embodiment, the first Gamma curve is the curve corresponding to Gamma 2.2 at room temperature (25°C).

[0051] Step 120: Obtain the current ambient temperature.

[0052] In this embodiment, the driving unit obtains the current temperature of the environment in which the display screen is located through a temperature sensor.

[0053] Step 130: Detect whether the current ambient temperature is within the first preset temperature range.

[0054] In this embodiment, the temperature is divided into multiple temperature ranges. The first preset temperature range can be called the preset temperature switching range. When the ambient temperature is within the first preset temperature range, the Gamma curve used to drive the display screen will switch. For example, based on zero degrees, the temperatures above zero and below zero are divided into multiple temperature ranges, of which some temperature ranges are the first temperature range.

[0055] Step 140: When the ambient temperature is within the first preset temperature range, the first color tone curve is switched to the second color tone curve pre-loaded into the temporary storage subunit of the driving unit, and the display screen is driven to work based on the second color tone curve; wherein, the second color tone curve is a color tone curve that has been pre-compensated to correspond to the first preset temperature range.

[0056] In this embodiment, the driving unit includes a driving IC (Integrated Circuit Chip) with a temporary storage sub-unit. This temporary storage sub-unit can be a register of the driving unit or a buffer / storage of the driving unit, such as SRAM (Static Random-Access Memory). This temporary storage sub-unit stores the Gamma curve to be switched. By pre-loading the Gamma curve into the temporary storage sub-unit, fast switching of the Gamma curve can be achieved, which is faster than traditional reading from flash memory. It is worth noting that the second Gamma curve is different from the first Gamma curve. This second Gamma curve is a pre-compensated Gamma curve adapted to the first preset temperature range. Within the first preset temperature range, the second Gamma curve can display the same brightness, color temperature, hue, and white balance as the curve corresponding to Gamma 2.2 at room temperature (25℃), thereby solving the problem of brightness, color temperature, hue, and white balance offset within the first preset temperature range.

[0057] In this embodiment, the temporary storage subunit of the driving unit preloads a second Gamma curve. Thus, when the ambient temperature is detected to be within the first preset temperature range, the driving Gamma curve can be quickly switched from the first Gamma curve to the second Gamma curve. Since this second Gamma curve adapts to the current ambient temperature, the brightness, color temperature, hue, and white balance of the display screen can all maintain the same level as the corresponding brightness, color temperature, hue, and white balance of the Gamma2.2 curve. This effectively avoids phenomena such as brightness attenuation, color temperature and hue shift, and white balance deviation. Furthermore, due to the fast switching speed, it is imperceptible to the naked eye, and the switching process does not cause significant changes in the brightness, color temperature, and hue of the display screen, making the user unaware of the switch and resulting in a better user experience.

[0058] In order to adapt to temperature changes in real time and load the color curve in a timely manner, in one embodiment, the color correction method of the display screen further includes: detecting whether the current ambient temperature is within a second preset temperature range; when the ambient temperature is within the second preset temperature range, obtaining the color curve corresponding to the ambient temperature as a third color curve, deleting the original color curve loaded in the temporary storage sub-unit, and loading the third color curve into the temporary storage sub-unit of the driving unit.

[0059] In this embodiment, the temperature is divided into multiple temperature ranges, each including a first preset temperature range and a second preset temperature range. The second preset temperature range can be referred to as the preset temperature loading range. When the ambient temperature is within the second preset temperature range, the Gamma curve will be loaded into the temporary storage subunit of the driving unit. Each first preset temperature range corresponds to a second preset temperature range, that is, the first preset temperature range and the second preset temperature range are adjacent on the temperature axis, and the area between two adjacent first preset temperature ranges is a second preset temperature range, and the area between two adjacent second preset temperature ranges is a first preset temperature range.

[0060] In order to enable the Gamma curve to be loaded into the temporary storage subunit of the driving unit as the temperature changes, and then switched, in one embodiment, the first preset temperature range and the second preset temperature range are set as follows: when the temperature is above zero, the temperature of the first preset temperature range is greater than the temperature of the corresponding second preset temperature range, and when the temperature is below zero, the temperature of the first preset temperature range is less than the temperature of the corresponding second preset temperature range. Thus, when the temperature is above zero, during the temperature rise, it first reaches a second preset temperature range, and the Gamma curve is initially loaded into the temporary storage unit. As the temperature continues to rise and reaches a first preset temperature range, the current Gamma curve is switched to the pre-loaded Gamma curve in the temporary storage unit. If the temperature continues to rise and reaches the next second preset temperature range, the Gamma curve corresponding to the next second preset temperature range is loaded into the temporary storage unit. When the temperature is below zero, during the temperature fall, it first reaches a second preset temperature range, and the Gamma curve is initially loaded into the temporary storage unit. As the temperature continues to fall and reaches the first preset temperature range, the current Gamma curve is switched to the pre-loaded Gamma curve in the temporary storage unit. If the temperature continues to fall and reaches the next second preset temperature range, and so on. Through the above settings, the temperature can first reach the second preset temperature range and then reach the first preset temperature range. It is worth mentioning that if the temperature fluctuates, such as rising and then falling, or falling and then rising, the above rules still apply, but this embodiment will not elaborate on this.

[0061] For example, such as Figure 2As shown, when the ambient temperature is 25℃, the current Gamma curve of the display driver is GMA #7, which corresponds to Gamma 2.2. When the ambient temperature rises, it first reaches the 32.5℃ range, at which point GMA #8 is loaded into the temporary storage unit. When the temperature continues to rise to the 40℃ range, GMA #7 is switched to GMA #8. When the temperature continues to rise to 50℃, GMA #9 is loaded into the temporary storage unit. When the temperature reaches 55℃, GMA #8 is switched back to GMA #9. Conversely, when the temperature drops, when it reaches 50℃, GMA #8 is loaded into the temporary storage unit. When the temperature continues to drop to 40℃, GMA #9 is switched back to GMA #8.

[0062] Furthermore, it is worth mentioning that, Figure 2 In this context, L / T (Loading Temperature) indicates that the loading conditions have been met, and S / T (Switching Temperature) indicates that the switching conditions have been met. Figure 2 Most of the L / T values ​​have been omitted, with only GMA #1 and GMA #10 retained. In the diagram, they are represented as GMA L / T #1 and GMA L / T #10.

[0063] By setting the first preset temperature range and the second preset temperature range, the temperature can be adapted in real time during the above process, and the Gamma curve can be loaded in a timely manner.

[0064] In one embodiment, the current ambient temperature change trend is detected, and it is detected whether the current ambient temperature is within a second preset temperature range; when the ambient temperature is within the second preset temperature range, according to the ambient temperature change trend, a hue curve corresponding to the next first preset temperature range is obtained as a third hue curve, the original hue curve loaded in the temporary storage subunit is deleted, and the third hue curve is loaded into the temporary storage subunit of the driving unit.

[0065] In this embodiment, the Gamma curve loaded into the temporary storage unit is pre-determined. In the example above, please refer to... Figure 2During the temperature rise process, when the temperature reaches 50℃, GMA#9 is loaded into the temporary storage sub-unit; during the temperature drop process from 55℃, when the temperature reaches 50℃, GMA#8 is loaded into the temporary storage unit. It can be seen that at the same ambient temperature of 50℃, different Gamma curves are loaded during the temperature rise and temperature drop processes. Therefore, in this embodiment, by combining the trend of ambient temperature change, the next first preset temperature range that the ambient temperature will reach according to the trend of ambient temperature change is obtained. Then, the Gamma curve corresponding to the first preset temperature range is used as the third Gamma curve and loaded into the temporary storage sub-unit. For example, when the temperature rises from 40°C, the driving Gamma curve is GMA#8. According to the trend of the temperature continuing to rise, the next driving Gamma curve is GMA#9. Therefore, when the temperature reaches 50°C, GMA#9 is loaded into the temporary storage sub-unit. During the process of the temperature falling from 55°C, the driving Gamma curve is GMA#9. According to the trend of the temperature continuing to fall, the next driving Gamma curve is GMA#8. Therefore, when the temperature reaches 50°C, GMA#8 is loaded into the temporary storage unit. In this way, according to the trend of ambient temperature change, the Gamma curve corresponding to the next first preset temperature range can be pre-loaded into the temporary storage sub-unit in advance, thereby adapting to temperature changes in real time, loading the Gamma curve in a timely manner, improving loading efficiency, and improving switching efficiency.

[0066] To avoid frequent switching of the Gamma curve, in one embodiment, the step of switching the first hue curve to a second hue curve pre-loaded into the driving unit when the ambient temperature is within the first preset temperature range, and driving the display screen based on the second hue curve, includes: when the time the ambient temperature is within the first preset temperature range reaches a preset time threshold, switching the first hue curve to a second hue curve pre-loaded into the temporary storage subunit of the driving unit, and driving the display screen based on the second hue curve.

[0067] In this embodiment, the preset time threshold can be 3 seconds, 5 seconds, or 6 seconds. This embodiment does not limit this. For ease of explanation, this embodiment uses a preset time threshold of 3 seconds for further explanation. In this embodiment, when the temperature reaches the first preset temperature range and remains within the first preset temperature range for 3 seconds, the first Gamma curve is switched to the second Gamma curve. In this way, when the ambient temperature is maintained within the first preset temperature range for more than 3 seconds, it indicates that the temperature has stabilized. Only then is the Gamma curve calculated, thereby avoiding repeated switching of the Gamma curve due to temperature changes.

[0068] In one embodiment, the color correction of the display screen further includes: obtaining a reference color curve; obtaining multiple preset temperature ranges corresponding to color curves to be compensated; comparing each of the color curves to be compensated with the reference color curve to obtain compensation parameters; and compensating each of the color curves to be compensated based on the compensation parameters to obtain pre-compensated color curves corresponding to each preset temperature range.

[0069] In this embodiment, the reference Gamma curve is the curve with Gamma 2.2 at room temperature (25℃). In this embodiment, the display screen is subjected to temperature testing by placing it in different ambient temperatures, such as placing it in a temperature chamber, and obtaining the Gamma curves of the display screen in different preset temperature ranges, thus obtaining the Gamma curve to be compensated. Figures 4A to 4C It is known that the trends of each Gamma curve to be compensated are different, and the correspondence between grayscale and brightness is different. In this embodiment, using the reference Gamma curve as a benchmark, each Gamma curve to be compensated is compensated using compensation parameters, so that after compensation, the trend of each Gamma curve to be compensated within the corresponding preset temperature range is the same as that of the reference Gamma curve, and the corresponding relationship between grayscale and brightness is the same for each Gamma curve to be compensated after compensation.

[0070] It is worth mentioning that the compensation parameters for different Gamma curves to be compensated can be the same or different.

[0071] In one embodiment, the step of obtaining the hue curves to be compensated corresponding to multiple preset temperature ranges includes: obtaining candidate curves for each preset temperature range based on multiple candidate hue parameters; comparing the candidate curves of each preset temperature range with the reference hue curve, and determining the candidate curve in each preset temperature range that is closest to the reference hue curve as the hue curve to be compensated for the preset temperature range.

[0072] In this embodiment, different Gamma curves, or candidate curves, are obtained for each preset temperature range under different candidate parameters. For example, if the preset temperature range is 85℃, multiple candidate curves can be obtained based on candidate Gamma parameters such as Gamma1.7, Gamma1.8, Gamma1.9, Gamma2.0, Gamma2.1, Gamma2.2, Gamma2.3...Gamma2.8 under a high temperature of 85℃. Comparing each candidate curve in the same preset temperature range with the reference Gamma curve reveals that the Gamma curve at 85℃ is biased towards Gamma 2.6. The curve corresponding to Gamma 1.8 at room temperature (25℃) is closer to Gamma 2.2 at 85℃ compared to other candidate Gamma parameters. Therefore, the curve corresponding to Gamma 1.8 at 85℃ is determined as the Gamma curve to be compensated. At 85℃, compensation parameters are used, with the reference Gamma curve as a benchmark, to compensate for the Gamma curve. The curve is 1.8, from which the deviation value is obtained, and this deviation value is the compensation parameter.

[0073] At a low temperature of -40℃, the Gamma curve is biased towards Gamma 1.8, while the curve corresponding to Gamma 2.6 at room temperature (25℃) is closer to Gamma 2.2 at -40℃. Therefore, the curve corresponding to Gamma 2.6 at -40℃ is determined as the Gamma curve to be compensated. By comparing it with the curve of Gamma 2.2, the deviation value is calculated using the preset Gamma deviation calculation algorithm. This deviation value is the compensation parameter.

[0074] In one embodiment, the step of comparing each of the tonal curves to be compensated with the reference tonal curve to obtain compensation parameters includes: using the reference tonal curve as a reference, compensating each of the tonal curves to be compensated based on the compensation parameters; and determining the compensation parameters when the deviation between each tonal curve to be compensated and the reference tonal curve is less than a preset deviation threshold.

[0075] In this embodiment, compensation parameters are used to compensate the Gamma curve to be compensated. During this process, the compensation parameters are adjusted until the deviation between the Gamma curve to be compensated and the reference Gamma curve is less than a preset deviation threshold. The compensation parameters at this point are then determined. The preset deviation threshold can be zero. When the preset deviation threshold is zero, the Gamma curve to be compensated is equal to the reference Gamma curve.

[0076] In one embodiment, before the step of driving the display screen to work based on the first color tone curve, the method further includes: obtaining the first color tone curve; obtaining a preset temperature range that is closest to the temperature corresponding to the first color tone curve as a third preset temperature range; obtaining a fourth color tone curve corresponding to the third preset temperature range; and loading the fourth color tone curve into the temporary storage subunit.

[0077] In this embodiment, the system is applicable to the initial power-on of the display screen. Upon power-on, both a first Gamma curve and a fourth Gamma curve are simultaneously acquired. The display screen is driven based on the first Gamma curve, and the fourth Gamma curve is loaded into the temporary storage subunit. The third preset temperature range is by default a temperature range adjacent to room temperature (25°C). Thus, when the display screen is powered on, the fourth Gamma curve corresponding to the third preset temperature range adjacent to room temperature is pre-loaded into the temporary storage subunit, allowing for switching to the pre-loaded fourth Gamma curve at any time as the temperature changes after power-on. It is worth noting that in some embodiments, the third preset temperature range is one or two second preset temperature ranges, and the third preset temperature range is a second preset temperature range adjacent to room temperature.

[0078] Example 2

[0079] It should be understood that displaying a Gamma curve of 2.2 ± 0.2 at room temperature is a common requirement. In harsh environments such as high or low temperatures, the Gamma curve may shift to Gamma 1.8 / Gamma 2.6. Therefore, the overall approach in this embodiment is as follows: First, at room temperature, the Gamma curve is automatically adjusted, a Gamma 2.2 LUT is generated, and the data is output. Then, high or low temperature environments are simulated to test the degree of Gamma shift at different temperatures, and compensation parameters for different temperatures are calculated. Next, the driver IC uses the aforementioned Gamma 2.2 LUT and the compensation parameters at different temperatures to generate Gamma LUTs corresponding to different temperatures. Finally, the driver IC monitors the temperature in real time and uses the temperature to call different Gamma LUTs. In the following embodiments, the Gamma LUT refers to the Gamma curve.

[0080] In this embodiment, an OLED display screen is used as an example for further explanation:

[0081] First, the effect of temperature on color and brightness was verified. Different ambient temperatures were simulated by placing the OLED display in chambers with different temperatures and aging it for 30 minutes until it stabilized. Then, the brightness and color coordinates of the display were tested and a coordinate system (x / y) was established based on this to generate raw data. Compensation parameters were then calculated based on this raw data.

[0082] Based on the measured data, a Gamma curve and color coordinates are fitted, such as... Figures 4A to 4C As shown:

[0083] At an ambient temperature of 85℃: the overall curve shows slight fluctuations, the Gamma curve is biased towards Gamma 2.4, or even 2.6, and the color coordinates have a large deviation.

[0084] At an ambient temperature of 40℃: the overall curve is smooth, the Gamma curve is close to the room temperature Gamma 2.2 curve, and the color scale is relatively stable;

[0085] At an ambient temperature of 10℃: the overall curve is smooth, the Gamma curve is generally biased towards Gamma 2.0, and the color scale is relatively stable;

[0086] At an ambient temperature of -30℃: the overall curves show significant deviations, with the Gamma curve leaning towards Gamma 2.0 and the color scale exhibiting slight fluctuations.

[0087] In summary, automotive OLED displays will exhibit varying degrees of deviation at different temperatures, specifically manifested in: brightness decay (EL device decay), color coordinate fluctuations, and overall shifts in the Gamma curve.

[0088] The specific implementation process of this embodiment is as follows:

[0089] Step 201: Obtain the reference Gamma curve.

[0090] In this embodiment, the reference Gamma curve is the Gamma 2.2 curve at room temperature (25.0℃).

[0091] Step 202: Obtain the Gamma curves to be compensated for multiple preset temperature ranges.

[0092] In this embodiment, candidate curves are obtained for each preset temperature range based on multiple candidate Gamma parameters; the candidate curves for each preset temperature range are compared with the reference Gamma curve, and the candidate curve that is closest to the reference Gamma curve in each preset temperature range is determined as the Gamma curve to be compensated for the preset temperature range.

[0093] In this embodiment, as Figure 2 As shown, the temperatures above and below zero are divided into 11 first preset temperature ranges. The candidate Gamma curves obtained in each of these 11 first preset temperature ranges under different candidate Gamma parameters are tested. The candidate curve in each preset temperature range that is closest to the reference Gamma curve is selected as the Gamma curve to be compensated.

[0094] For example, with a preset temperature range of 85℃, multiple candidate curves can be obtained based on candidate Gamma parameters such as Gamma1.7, Gamma1.8, Gamma1.9, Gamma2.0, Gamma2.1, Gamma2.2, Gamma2.3...Gamma2.8 under a high temperature of 85℃. Comparing each candidate curve in the same preset temperature range with the reference Gamma curve reveals that the Gamma curve at 85℃ is biased towards Gamma 2.6. However, the curve corresponding to Gamma 1.8 at room temperature (25℃) is closer to Gamma 2.2 at 85℃ compared to other candidate Gamma parameters. Therefore, the curve corresponding to Gamma 1.8 at 85℃ is determined as the Gamma curve to be compensated.

[0095] At a low temperature of -40℃, the Gamma curve is biased towards Gamma 1.8, while the curve corresponding to Gamma 2.6 at room temperature (25℃) is close to Gamma 2.2 at -40℃. Therefore, the curve corresponding to Gamma 2.6 at -40℃ is determined to be the Gamma curve to be compensated.

[0096] Step 203: Compare each of the Gamma curves to be compensated with the reference Gamma curve to obtain the compensation parameters.

[0097] In this step, based on the comparison between the Gamma curve to be compensated and the reference Gamma curve, the deviation value is calculated using the compensation formula, and this deviation value is the compensation parameter.

[0098] For example, at a temperature of 85℃, using compensation parameters and a reference Gamma curve as a benchmark, the curve based on Gamma 1.8 is compensated to obtain the deviation value, which is the compensation parameter. Alternatively, by comparing the curve with Gamma 2.2, the deviation value is calculated using a preset Gamma deviation calculation algorithm; this deviation value is also the compensation parameter.

[0099] Step 204: Compensate each of the Gamma curves to be compensated based on each of the compensation parameters to obtain pre-compensated Gamma curves corresponding to each of the preset temperature ranges.

[0100] The specific process is as follows: using the reference Gamma curve as a benchmark, each of the Gamma curves to be compensated is compensated based on the compensation parameters. When the deviation between each of the Gamma curves to be compensated and the reference Gamma curve is less than a preset deviation threshold, the compensation parameters are determined.

[0101] In the above steps, the display module is placed in a temperature chamber to test the trend of the Gamma curve and the brightness of different gray levels at different temperatures.

[0102] Knowing the different Gamma trends of the display module at different temperatures, we can determine how to calibrate the Gamma curve based on Gamma2.2.

[0103] For example, tuning Gamma 2.2 at room temperature (25°C) yields a set of DGA 2.2 LUTs.

[0104] At a high temperature of 85℃, the Gamma curve is biased towards 2.6. At room temperature, tuning Gamma to 1.8 (at 85℃, the Gamma curve is close to 2.2) yields a set of DGA 1.8 LUTs. By comparing with the DGA 2.2 LUTs, a set of offset data (compensation parameters) is calculated using an algorithm.

[0105] At a low temperature of -40℃, the Gamma curve is biased towards 1.8. At room temperature, tuning Gamma to 2.6 (at -40℃, the Gamma curve is close to 2.2) yields a set of DGA 2.6 LUTs. By comparing with the DGA 2.2 LUTs, another set of offset data is calculated using an algorithm.

[0106] By refining each temperature node, multiple sets of offset data corresponding to different temperatures can be obtained, and the offset data can be saved in Flash. Based on different modules (DGA 2.2 LUT is different), the Gamma matching LUT at different temperatures can be calculated; that is: Gamma matching LUT = DGA 2.2 LUT + offset data.

[0107] like Figure 5A As shown in the curve with Gamma 2.2 at room temperature, a gray level of 255 corresponds to a brightness of 900 nits. Figure 5B As shown, when the display module is placed in a low-temperature environment, the Gamma curve shifts to Gamma 2.x. At a grayscale value of 255, the corresponding brightness is 600 nits. The curve is then compensated for, resulting in the following curve compensation: Figure 5C As shown, subsequently, curve compensation and brightness compensation are performed simultaneously, as follows: Figure 5D As shown, the compensated Gamma curve is obtained, and the deviation between this Gamma curve and the curve of Gamma 2.2 at room temperature is less than the preset deviation threshold.

[0108] It should be understood that the compensation parameters for different display models are different in different preset temperature ranges. The above embodiments can be applied to various display models, which will not be described in detail.

[0109] The pre-compensated Gamma curves corresponding to each preset temperature range obtained above are stored in the flash memory, so that the driver IC can read each pre-compensated Gamma curve from the flash memory. In addition, the flash memory also stores the Gamma 2.2 curve at room temperature, i.e., the reference Gamma curve.

[0110] After the display screen is powered on, perform the following steps:

[0111] Step 205: Read the first Gamma curve and the pre-compensated Gamma curves corresponding to multiple preset temperature ranges from the storage unit, and select a temporary storage sub-unit pre-loaded into the drive unit from the pre-compensated Gamma curves corresponding to the multiple preset temperature ranges. The selected pre-compensated Gamma curve is the Gamma curve corresponding to the preset temperature range adjacent to room temperature (25℃).

[0112] In this embodiment, as Figure 3 As shown, the first Gamma curve is the default Gamma curve, which is the curve with Gamma 2.2 at room temperature. The storage unit stores Gamma curves corresponding to 11 preset temperature ranges. One of the Gamma curves corresponding to the preset temperature ranges is selected and pre-loaded into the temporary storage sub-unit of the drive unit. The selected Gamma curve is the Gamma curve corresponding to the preset temperature range adjacent to room temperature (25℃).

[0113] Step 206: Drive the display screen to work based on the first Gamma curve.

[0114] In this embodiment, the display screen is driven by the first Gamma curve by default after power-on. In this embodiment, the default first Gamma curve is GMA#7.

[0115] Step 207: Obtain the current ambient temperature.

[0116] Step 208: Detect whether the current ambient temperature is within the first preset temperature range.

[0117] Step 209: When the ambient temperature is within the first preset temperature range, and the time the ambient temperature is within the first preset temperature range reaches a preset time threshold, the first Gamma curve is switched to the second Gamma curve pre-loaded into the temporary storage subunit of the driving unit, and the display screen is driven to work based on the second Gamma curve; wherein, the second Gamma curve is a Gamma curve that has been pre-compensated to correspond to the first preset temperature range.

[0118] In this embodiment, when the temperature is within the first preset temperature range, the Gamma curve that drives the display screen is switched from the first Gamma curve to the second Gamma curve that is preloaded into the temporary storage subunit of the driving unit.

[0119] Step 210: Detect whether the current ambient temperature is within the second preset temperature range.

[0120] Step 211: When the ambient temperature is within the second preset temperature range, obtain the Gamma curve corresponding to the ambient temperature as the third Gamma curve, delete the original Gamma curve loaded in the temporary storage sub-unit, and load the third Gamma curve into the temporary storage sub-unit of the driving unit.

[0121] Here is a specific example:

[0122] First, please combine Figure 2 and Figure 3 When the display is powered on, it loads two GammaLUTs from the Flash memory and stores them in the DGA SRAM of the driver IC. By default, the room temperature (10℃~25℃) Gamma2.2 LUT, i.e. GMA#7, is used to drive the display.

[0123] During the operation of the display, the temperature sensor detects the temperature in real time. If the temperature reaches 50℃~55℃ and is maintained in this temperature range for 3 seconds, the driver IC will load the GMA#9 Gamma2.0 LUT from the Flash memory unit to the temperature DGA SRAM.

[0124] Once the temperature reaches 55℃~60℃ and remains within this temperature range for 3 seconds, the driver IC will determine that the temperature limit (55℃) has been exceeded. It will immediately call the Gamma LUT (i.e. Gamma2.0 LUT) of the temperature DGA SRAM and slowly switch the Gamma LUT to achieve a change that is imperceptible to the driver's naked eye.

[0125] Similarly, other temperature changes follow the same principle. When the L / T condition (Loading Temperature) is reached, the driver IC loads a new Gamma LUT from the Flash. When the S / T condition (Switching Temperature) is reached, the driver IC switches to a new Gamma LUT to compensate for the Gamma offset problem.

[0126] For example, when the temperature rises to 40℃, GMA#8 is called to drive the display screen. When the temperature reaches 50℃, GMA#9 is loaded into the temporary sub-unit. When the temperature reaches 55℃, GMA#9 is called to switch GMA#8 to GMA#9 and drive the display screen.

[0127] When the temperature drops to 55℃, GMA#9 is invoked to drive the display screen. When the temperature reaches 50℃, GMA#8 is loaded into the temporary storage sub-unit. When the temperature reaches 40℃, GMA#8 is invoked, switching from GMA#9 to GMA#8 to drive the display screen.

[0128] The above process of loading Gamma LUT involves selecting the next Gamma LUT for the first preset temperature range based on the temperature change trend.

[0129] Example 3

[0130] In this embodiment, a display device is provided, such as... Figure 3 As shown, the display includes a driving unit 310, wherein the driving unit 310 has a temporary storage subunit 311; the driving unit 310 is configured to drive the display screen based on a first color tone curve; the driving unit 310 is also configured to acquire the current ambient temperature, detect whether the current ambient temperature is within a first preset temperature range, and when the ambient temperature is within the first preset temperature range, switch the first color tone curve to a second color tone curve pre-loaded into the temporary storage subunit 311; drive the display screen based on the switched second color tone curve; wherein the second color tone curve is a color tone curve pre-compensated to correspond to the first preset temperature range.

[0131] In this embodiment, the driving unit 310 includes a driving IC. The temporary storage subunit 311 can be a register of the driving unit 310 or a buffer / temporary storage of the driving unit 310. In one embodiment, the temporary storage subunit is SRAM. The driving unit 310 obtains the current ambient temperature through a temperature sensor, such as... Figure 3As shown, the temporary storage subunit 311 of the driving unit 310 obtains multiple Gamma curves corresponding to preset temperature ranges by reading from the storage unit 320, and loads one of them into the temporary storage subunit 311. In addition, the driving unit 310 reads the Flash Memory of the storage unit 320 to obtain the default Gamma curve DefaultGMA 2.2, and drives the display screen based on this default Gamma curve. When the ambient temperature is within the first preset temperature range, the Gamma curve is switched to the second Gamma curve loaded in the temporary storage subunit 311.

[0132] In this embodiment, the temporary storage subunit 311 of the driving unit 310 preloads a second Gamma curve. Thus, when the ambient temperature is detected to be within the first preset temperature range, the driving Gamma curve can be quickly switched from the first Gamma curve to the second Gamma curve. Since the second Gamma curve is adapted to the current ambient temperature, the brightness, color temperature, hue, and white balance of the display screen can all be kept at the same level as the brightness, color temperature, hue, and white balance corresponding to the Gamma2.2 curve. This effectively avoids phenomena such as brightness attenuation, color temperature and hue shift, and white balance deviation. Moreover, because the switching speed is fast, it is imperceptible to the naked eye. During the switching process, there will be no obvious changes in the brightness, color temperature, and hue of the display screen, so that the user cannot perceive the switching, resulting in a better user experience.

[0133] In one embodiment, the display device further includes a storage unit 320, which is configured to store a plurality of hue curves corresponding one-to-one with a plurality of preset temperature ranges; the driving unit 310 is further configured to detect whether the current ambient temperature is within a second preset temperature range; when the ambient temperature is within the second preset temperature range, the hue curve corresponding to the ambient temperature is obtained from the storage unit 320 as a third hue curve, the originally loaded hue curve is deleted, and the third hue curve is loaded into the temporary storage subunit 311.

[0134] In this embodiment, the storage unit 320 includes flash memory, such as... Figure 3 As shown, the storage unit 320 stores Gamma curves corresponding to 11 preset temperature ranges, as well as a default Gamma curve. When the ambient temperature changes and falls within the second preset temperature range, the Gamma curve loaded into the temporary storage subunit 311 is replaced with the third Gamma curve. This allows the Gamma curve to be loaded into the temporary storage subunit 311 of the driving unit 310 first, and then switched, effectively improving switching efficiency.

[0135] In one embodiment, the driving unit 310 is further configured to switch the first hue curve to a second hue curve preloaded to the temporary storage subunit 311 when the ambient temperature is within the first preset temperature range for a preset time threshold, and drive the display screen to work based on the second hue.

[0136] In this embodiment, when the ambient temperature reaches a preset time threshold within the first preset temperature range, it indicates that the ambient temperature has been maintained within the first preset temperature range for a relatively long time. At this point, the Gamma curve can be switched. This avoids repeatedly switching the Gamma curve due to temperature changes.

[0137] In one embodiment, a display screen is provided, wherein the display screen is subjected to Gamma correction using the display screen Gamma correction method described in any of the above embodiments.

[0138] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0139] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A display device, characterized in that, Includes a driving unit, the driving unit having a temporary storage subunit; The driving unit is configured to drive the display screen based on a first hue curve. The driving unit is also configured to acquire the current ambient temperature, detect whether the current ambient temperature is within a first preset temperature range, and when the ambient temperature is within the first preset temperature range, switch the first color tone curve to a second color tone curve pre-loaded into the temporary storage subunit; drive the display screen to work based on the switched second color tone curve; wherein, the second color tone curve is a color tone curve pre-compensated to correspond to the first preset temperature range; The display device also includes a storage unit. The storage unit is configured to store multiple hue curves that correspond one-to-one with multiple preset temperature ranges; The driving unit is also configured to detect the current ambient temperature change trend and detect whether the current ambient temperature is within a second preset temperature range; when the ambient temperature is within the second preset temperature range, according to the ambient temperature change trend, obtain the hue curve corresponding to the next first preset temperature range as a third hue curve, delete the original hue curve loaded in the temporary storage subunit, and load the third hue curve into the temporary storage subunit. The first preset temperature range and the second preset temperature range are adjacent on the temperature axis. The space between two adjacent first preset temperature ranges is a second preset temperature range, and the space between two adjacent second preset temperature ranges is a first preset temperature range.

2. The display device according to claim 1, characterized in that, The driving unit is also configured to switch the first hue curve to a second hue curve pre-loaded into the temporary storage unit when the ambient temperature is within the first preset temperature range for a preset time threshold, and drive the display screen to work based on the second hue.

3. A method for color tone correction of a display screen, characterized in that, include: The display screen is driven based on the first color tone curve. Get the current ambient temperature; Detect whether the current ambient temperature is within the first preset temperature range; When the ambient temperature is within the first preset temperature range, the first color tone curve is switched to the second color tone curve pre-loaded into the temporary storage subunit of the driving unit, and the display screen is driven to work based on the second color tone curve; wherein, the second color tone curve is a color tone curve that has been pre-compensated to correspond to the first preset temperature range; The method further includes: Detect the current trend of ambient temperature change, and detect whether the current ambient temperature is within the second preset temperature range; When the ambient temperature is in the second preset temperature range, according to the trend of the ambient temperature change, the hue curve corresponding to the next first preset temperature range is obtained as the third hue curve, the original hue curve loaded in the temporary storage sub-unit is deleted, and the third hue curve is loaded into the temporary storage sub-unit of the driving unit. The first preset temperature range and the second preset temperature range are adjacent on the temperature axis. The space between two adjacent first preset temperature ranges is a second preset temperature range, and the space between two adjacent second preset temperature ranges is a first preset temperature range.

4. The color tone correction method for a display screen according to claim 3, characterized in that, The step of switching the first color tone curve to a second color tone curve pre-loaded into the driving unit when the ambient temperature is within the first preset temperature range, and driving the display screen to work based on the second color tone curve, includes: When the ambient temperature remains within the first preset temperature range for a preset time threshold, the first color tone curve is switched to the second color tone curve pre-loaded into the temporary storage subunit of the driving unit, and the display screen is driven to work based on the second color tone.

5. The color tone correction method for a display screen according to claim 3, characterized in that, Also includes: Obtain a reference tone curve; Obtain the hue curves to be compensated for multiple preset temperature ranges; Each of the to-be-compensated tone curves is compared with the reference tone curve to obtain compensation parameters; Each of the aforementioned compensation parameters is used to compensate for each of the aforementioned hue curves to be compensated, thereby obtaining a pre-compensated hue curve corresponding to each of the aforementioned preset temperature ranges.

6. The color tone correction method for a display screen according to claim 5, characterized in that, The step of obtaining the hue curves to be compensated corresponding to multiple preset temperature ranges includes: Obtain candidate curves for each preset temperature range based on multiple candidate hue parameters; The candidate curve for each preset temperature range is compared with the reference hue curve, and the candidate curve that is closest to the reference hue curve in each preset temperature range is determined as the hue curve to be compensated for in the preset temperature range.

7. The color tone correction method for a display screen according to claim 5, characterized in that, The step of comparing each of the to-be-compensated tone curves with the reference tone curve to obtain compensation parameters includes: Using the reference hue curve as a reference, each of the hue curves to be compensated is compensated based on the compensation parameters. When the deviation between each of the hue curves to be compensated and the reference hue curve is less than a preset deviation threshold, the compensation parameters are determined.

8. The color tone correction method for a display screen according to claim 3, characterized in that, The step of driving the display screen based on the first hue curve is preceded by: Obtain the first hue curve; The preset temperature range that is closest to the temperature corresponding to the first hue curve is obtained as the third preset temperature range; Obtain the fourth hue curve corresponding to the third preset temperature range; The fourth hue curve is loaded into the temporary storage subunit.

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