WO2017121140A1

WO2017121140A1 - Display control method and device for liquid crystal display screen

Info

Publication number: WO2017121140A1
Application number: PCT/CN2016/098661
Authority: WO
Inventors: 宁超; 曹谦; 苏文华; 姚键; 潘柏宇; 王冀
Original assignee: 合一智能科技（深圳）有限公司
Priority date: 2016-01-15
Filing date: 2016-09-12
Publication date: 2017-07-20
Also published as: CN105528999A; CN105528999B

Abstract

A display control method and device for a liquid crystal display screen. The method comprises carrying out the following adjustment on a brightness value corresponding to a grayscale value of each pixel in a liquid crystal display screen according to a standard brightness changing curve: adjusting a brightness value corresponding to a first grayscale value in a first grayscale range to be lower than a corresponding brightness value of the first grayscale value on a standard brightness changing curve (101); and adjusting a brightness value corresponding to a second grayscale value in a second grayscale range to be higher than a corresponding brightness value of the second grayscale value on the standard brightness changing curve (103), wherein the grayscale value in the first grayscale range is smaller than the grayscale value in the second grayscale range. In the method, by twisting a standard brightness changing curve, a large visual angle colour bias can be improved, distortion can be reduced, and display effect can be obviously improved.

Description

Display control method and device for liquid crystal display

cross reference

The present application claims priority to Chinese Patent Application No. 201610027395.3, filed Jan.

Technical field

The present invention relates to the field of liquid crystal display, and in particular, to a display control method and apparatus for a liquid crystal display.

Background technique

Liquid crystal display (LCD) is widely used and popularized due to its advantages of energy saving, environmental protection and light weight. A liquid crystal display using a vertical alignment (VA) driving mode is generally recognized in the market because of its high contrast ratio and fast response speed.

However, the VA drive has a natural defect: the color shift phenomenon is more serious when viewed at a large viewing angle (ie, side view), that is, the large viewing angle appears to be distorted, and in severe cases, the image is not even visible.

Summary of the invention

technical problem

In view of this, the technical problem to be solved by the present invention is how to improve the visual effect of the liquid crystal display at a large viewing angle.

solution

In order to solve the above technical problem, according to an embodiment of the invention, a display control method for a liquid crystal display panel is provided, including:

Adjusting the brightness value corresponding to the grayscale value of each pixel in the liquid crystal display according to a standard brightness change curve as follows:

Adjusting a brightness value corresponding to the first gray level value in the first gray level range to be lower than the brightness value corresponding to the first gray level value on the standard brightness change curve, and being in the second gray level range The brightness value corresponding to the second gray level value is adjusted to be higher than the brightness value corresponding to the second gray level value on the standard brightness change curve; wherein the gray level value in the first gray level range is smaller than The grayscale value in the second grayscale range.

For the above method, in a possible implementation manner, each grayscale value of each pixel in the liquid crystal display is divided into three grayscale ranges;

The first grayscale range includes a low grayscale value from 0 to a first threshold, and the intermediate grayscale range includes an intermediate grayscale value from a first threshold to a second threshold, the second grayscale range including The second threshold to the highest grayscale high grayscale value.

For the above method, in a possible implementation, the brightness value corresponding to the grayscale value of each pixel in the liquid crystal display is adjusted according to a standard brightness change curve, and further includes:

And setting a brightness value corresponding to the third gray level value in the middle gray scale range to be equal to a brightness value corresponding to the third gray level value on the standard brightness change curve.

For the above method, in a possible implementation manner, the method further includes:

Generating at least one adjustment curve according to grayscale values and luminance values of each of the pixels in the first grayscale range, the intermediate grayscale range, and the second grayscale range;

The driving voltage of the liquid crystal display in the vertical alignment driving mode is controlled according to the grayscale value and the luminance value in the adjustment curve used.

In a possible implementation manner, the method further includes: adjusting a red saturation of each of the pixels in the liquid crystal display.

The present invention also provides a display control device for a liquid crystal display, which can adjust a brightness value corresponding to a grayscale value of each pixel in the liquid crystal display according to a standard brightness change curve, the device include:

a first adjustment module, configured to adjust a brightness value corresponding to the first gray level value in the first gray level range to be lower than a brightness value corresponding to the first gray level value on the standard brightness change curve;

a second adjustment module, configured to adjust a brightness value corresponding to the second gray level value in the second gray level range to be higher than a brightness value corresponding to the second gray level value on the standard brightness change curve;

The grayscale value in the first grayscale range is smaller than the grayscale value in the second grayscale range.

For the above device, in a possible implementation manner, each grayscale value of each pixel in the liquid crystal display is divided into three grayscale ranges; wherein the first grayscale range includes from 0 to a first threshold. a low grayscale value, the intermediate grayscale range including an intermediate grayscale value from a first threshold to a second threshold, the second grayscale range including a high grayscale value from the second threshold to the highest grayscale.

For the above device, in a possible implementation manner, the method further includes:

And a setting module, configured to set a brightness value corresponding to the third gray level value in the middle gray scale range to be equal to a brightness value corresponding to the third gray level value on the standard brightness change curve.

a curve generating module, respectively connected to the first adjusting module, the second adjusting module, and the setting module, configured to: in the first grayscale range, the intermediate grayscale range, and the second gray according to each of the pixels a gray scale value and a brightness value within the range, generating at least one adjustment curve;

The driving module is connected to the curve generating module, and is configured to control a driving voltage of the liquid crystal display in the vertical alignment driving mode according to the grayscale value and the brightness value in the adopted adjustment curve.

The saturation adjustment module adjusts the red saturation of each of the pixels in the liquid crystal display.

Beneficial effect

The display control method of the liquid crystal display of the embodiment, by twisting the standard brightness change curve, It can improve the role of the big vision, reduce distortion, and significantly improve the display.

Further features and aspects of the present invention will become apparent from the Detailed Description of the Drawing.

DRAWINGS

The accompanying drawings, which are incorporated in FIG

1 is a flow chart showing a display control method of a liquid crystal display according to an embodiment of the present invention;

2 is a schematic view showing a Gamma curve in a display control method of a liquid crystal display according to an embodiment of the present invention;

Figure 3 is a partial enlarged view of the Gamma curve of Figure 2 at a low gray level;

4 is a screen of the prior art in a normal front view;

Figure 5 is a view of the prior art when the display screen is viewed from a side angle of 45 degrees;

6 is a view showing a screen when a display control method of a liquid crystal display panel is stretched after a curve according to an embodiment of the present invention;

7 is a view showing a screen when the display control method of the liquid crystal display panel is stretched and viewed from the side of the curve according to an embodiment of the present invention;

8 is a flow chart showing a display control method of a liquid crystal display according to another embodiment of the present invention;

9 is a block diagram showing the structure of a display control device for a liquid crystal display according to an embodiment of the present invention;

FIG. 10 is a block diagram showing the structure of a display control device for a liquid crystal display according to another embodiment of the present invention.

detailed description

Various exemplary embodiments, features, and aspects of the invention are described in detail below with reference to the drawings. The same reference numerals in the drawings denote the same or similar elements. Although the various aspects of the embodiments are illustrated in the drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustrative." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or preferred.

In addition, numerous specific details are set forth in the Detailed Description of the invention in the Detailed Description. Those skilled in the art will appreciate that the invention may be practiced without some specific details. In some instances, methods, means, components, and circuits that are well known to those skilled in the art are not described in detail in order to facilitate the invention.

Since the VA type liquid crystal display is liable to cause variations in color and brightness when viewed at a large viewing angle, the image is distorted. However, this defect of the VA type liquid crystal display is inherent in the design, and can only be improved as much as possible: the process can be improved, and the driving method can be improved. The embodiment of the invention provides a simple and effective method: the gamma curve is twisted by the system on chip (SOC), and the role of the large-view character, especially the skin color picture, is improved, and the effect is obvious.

Example 1

1 shows a flow chart of a display control method of a liquid crystal display according to an embodiment of the present invention. As shown in FIG. 1 , the display control method of the liquid crystal display is mainly used to adjust the brightness value corresponding to the gray scale value of each pixel in the liquid crystal display according to a standard brightness change curve as follows:

Step 101: Adjust a brightness value corresponding to the first gray level value in the first gray level range to be lower than a brightness value corresponding to the first gray level value on the standard brightness change curve.

Step 102: Set a brightness value corresponding to a third gray level value in an intermediate gray level range to be equal to a brightness value corresponding to the third gray level value on the standard brightness change curve.

Step 103: Adjust a brightness value corresponding to the second gray level value in the second gray level range to be higher than a brightness value corresponding to the second gray level value on the standard brightness change curve.

In a possible implementation, the gray scale range of each pixel of the liquid crystal display is usually from 0 to 255, 0 to 255 can be divided into low, medium and high gray scale ranges: the first gray scale range is low gray scale, including low gray scale values from 0 to the first threshold; the middle gray scale range is middle Gray scale, including an intermediate grayscale value from a first threshold to a second threshold; the second grayscale range is a high grayscale, including from a second threshold to a highest grayscale (eg, currently considered to be 255, but not limited thereto) High grayscale value. The grayscale value in the first grayscale range is smaller than the grayscale value in the middle grayscale range, and the grayscale value in the middle grayscale range is smaller than the grayscale value in the second grayscale range. The specific gray-scale range is not limited, and the gray-scale range is not limited.

The timing relationship of step 101 to step 103 is not limited in the embodiment of the present invention. Preferably, the corresponding brightness value can be adjusted in descending order of gray scale values. Of course, the corresponding brightness values may be adjusted in order from grayscale values to high or low, or may be adjusted according to different grayscale range segments. The luminance value corresponding to each grayscale value in the middle grayscale range of step 102 may also default to conform to the standard luminance variation curve, so that the setting action of step 102 may be omitted.

Specifically, in view of the perceptual characteristics of the human eye, the liquid crystal display generally needs to adjust the relationship between the gray scale and the brightness of each pixel to the form of the Gamma curve of the following formula 1:

Lv=Gray ^γ Equation 1

Where Lv is the brightness and Gray is the gray level. Preferably, γ = 2.2, but not limited to 2.2.

That is to say: with the brightness meter facing a fixed point on the display, the display shows a white screen of 0, 1, ... 255 grayscale values, respectively recording the brightness value at this time. You can draw a solid line as shown in Figure 2 above. At this time, the observation effect of the human eye is the best, as shown in Fig. 4, which is the normal front view.

However, if the brightness meter is deflected at an angle to the display screen in the horizontal direction, the simulated person observes the screen from the side, and the curve measured by the above method will be largely offset, as shown by the thick dotted line in FIG. Among them, the low gray level brightness is high, and the high gray level brightness is low. At this time, the screen on the screen will observe whitening or even color cast. As shown in Figure 5, the screen when viewing the display from a 45-degree angle on the side will be noticeably White.

The reason for this phenomenon is that the Gamma curve at a large viewing angle (ie, the luminance change curve at a large viewing angle) and the ideal curve (standard luminance variation curve) have a large deviation, and this patent proposes a reverse-twisted Gamma curve. Way.

Since the human eye perceives the change in brightness mainly by the relative change in brightness, if the ideal curve is smoothly shifted within a certain range, the human eye does not clearly perceive the difference, that is, there is a range that can be floated. Based on this principle, we hope to find a curve that is acceptable for both side and front view.

When facing up, the current brightness curve (standard gamma curve) is distorted to the dotted line in Figure 2 (optimized curve). The low gray level brightness is depressed to a certain extent, and the high gray level brightness is appropriately raised. As shown in FIG. 3, an enlarged view of the low gray level brightness change curve is shown. The intermediate gray level can be left unprocessed. For example, the low gray level is 0 to 30 gray scales, the middle gray scale is 31 to 240 gray scales, and the high gray scale is 241 to 255 gray scales. The specific demarcation points of the low gray level, the intermediate gray level, and the high gray level are not limited in the embodiment of the present invention, and may be flexibly processed according to specific situations. Moreover, it is advisable to adjust the amount of the specific adjustment, and it can also be weighed according to the improvement of the picture of the front view and the side view. The general principle is to give priority to ensuring that there are no obvious problems in the front view, that the large view should be improved as appropriate, and that the picture should not be significantly worse than the stretched gamma curve when changing from the positive view to the maximum view (90 degrees). Happening.

This way people will not feel the obvious brightness and color changes. As shown in Fig. 6, the picture when the curve is stretched and then viewed from the front is not significantly changed compared with that before stretching. In the side view, because the offset curve is reverse stretched, the color shift problem will be improved. As shown in Fig. 7, it is a picture in the side view after stretching, which is significantly improved than the side view before stretching, the picture is clearer, and the color and brightness are not significantly distorted.

In the display control method of the liquid crystal display panel of the embodiment, by distorting the standard brightness change curve such as the gamma curve, the large-view character deviation of the liquid crystal display, especially the VA type liquid crystal display, can be improved, the distortion is reduced, and the display effect is obviously improved.

Example 2

FIG. 8 is a flow chart showing a display control method of a liquid crystal display according to another embodiment of the present invention. The steps in FIG. 8 having the same reference numerals as in FIG. 1 have the same functions, and a detailed description of these steps will be omitted for the sake of brevity.

As shown in FIG. 8, the main difference from the previous embodiment is that the display control method of the liquid crystal display further includes:

Step 104: Generate at least one adjustment curve according to grayscale values and luminance values of the pixels in the first grayscale range, the intermediate grayscale range, and the second grayscale range. As shown in FIG. 2 and FIG. 3, the abscissa of the adjustment curve (the optimized curve and the optimized curve in the figure) is a gray scale value, and the ordinate is a brightness value;

Step 105: Control a driving voltage of the liquid crystal display in the vertical alignment driving mode according to the grayscale value and the brightness value in the adopted adjustment curve.

Since the focus should be on improving the display of the skin tone at a large viewing angle, and the red color has a major influence on the skin color, a step of adjusting the red saturation can be added after stretching the gamma to further optimize the display effect. Therefore, in a possible implementation manner, the display control method of the liquid crystal display further includes: adjusting a red saturation of each of the pixels in the liquid crystal display.

The embodiment of the invention can be realized by software in the SOC, which is simpler and more economical than the method of changing the process; can be set in the liquid crystal display manufacturer, or can be set in the television factory using the liquid crystal display; even several groups can be set differently The improvement curve (that is, the generation of multiple adjustment curves), and finally let consumers choose according to their own preferences.

Of course, these distorted Gamma curves (ie, adjustment curves) can also be saved in a driving panel of a liquid crystal display such as a Tcon (Timing Controller) board, or other signal processing boards. This embodiment does not limit where the parameters of these curves are specifically saved. What is important is that the parameters of these distorted Gamma curves can be used to control the driving voltage of the liquid crystal display to improve the liquid crystal display at a large viewing angle. Color shift, which reduces distortion and improves display efficiency fruit.

Example 3

FIG. 9 is a block diagram showing the structure of a display control device for a liquid crystal display according to an embodiment of the present invention. The display control device can adjust the brightness value corresponding to the grayscale value of each pixel in the liquid crystal display according to the standard brightness change curve. As shown in FIG. 9, the display control device can further include: a first adjustment module 11, And a brightness value corresponding to the first gray level value in the first gray level range is adjusted to be lower than a brightness value corresponding to the first gray level value on the standard brightness change curve; the second adjustment module 13 And a brightness value corresponding to the second gray level value in the second gray level range is adjusted to be higher than the brightness value corresponding to the second gray level value on the standard brightness change curve; wherein the first The grayscale value in the grayscale range is smaller than the grayscale value in the second grayscale range.

The display control device of the liquid crystal display panel of the embodiment can distort the standard brightness change curve, thereby improving the large-view role deviation of the liquid crystal display, especially the VA type liquid crystal display, reducing distortion, and obviously improving the display effect. For specific principles and examples, refer to the related description of Embodiment 1.

Example 4

FIG. 10 is a block diagram showing the structure of a display control device for a liquid crystal display according to another embodiment of the present invention. The components in FIG. 10 having the same reference numerals as those in FIG. 9 have the same functions, and a detailed description of these components will be omitted for the sake of brevity.

As shown in FIG. 10, the main difference from the previous embodiment is that each grayscale value of each pixel in the liquid crystal display is divided into three grayscale ranges; wherein the first grayscale range includes from 0 to a low grayscale value of the first threshold, the intermediate grayscale range including an intermediate grayscale value from the first threshold to the second threshold, the second grayscale range including a high grayscale value from the second threshold to the highest grayscale.

In a possible implementation, the display control device of the liquid crystal display further includes:

The setting module 15 is configured to set a brightness value corresponding to the third gray level value in the middle gray scale range to be equal to a brightness value corresponding to the third gray level value on the standard brightness change curve.

The curve generating module 17 is respectively connected to the first adjusting module 11 , the second adjusting module 13 and the setting module 15 for using the first gray scale range, the intermediate gray scale range and the Generating at least one adjustment curve by the grayscale value and the luminance value in the second grayscale range;

The driving module 19 is connected to the curve generating module 17 for controlling the driving voltage of the liquid crystal display in the vertical alignment driving mode according to the grayscale value and the brightness value in the adopted adjustment curve.

The saturation adjustment module 20 adjusts the red saturation of each of the pixels in the liquid crystal display.

The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

A display control method for a liquid crystal display, comprising:

Adjusting the brightness value corresponding to the grayscale value of each pixel in the liquid crystal display according to a standard brightness change curve as follows:

Adjusting a brightness value corresponding to the first gray level value in the first gray level range to be lower than the brightness value corresponding to the first gray level value on the standard brightness change curve, and being in the second gray level range The brightness value corresponding to the second gray level value is adjusted to be higher than the brightness value corresponding to the second gray level value on the standard brightness change curve; wherein the gray level value in the first gray level range is smaller than The grayscale value in the second grayscale range.
The method according to claim 1, wherein each grayscale value of each pixel in the liquid crystal display is divided into three grayscale ranges;

The first grayscale range includes a low grayscale value from 0 to a first threshold, and the intermediate grayscale range includes an intermediate grayscale value from a first threshold to a second threshold, the second grayscale range including The second threshold to the highest grayscale high grayscale value.
The method according to claim 2, wherein the brightness value corresponding to the grayscale value of each pixel in the liquid crystal display is adjusted according to a standard brightness change curve, and further includes:

And setting a brightness value corresponding to the third gray level value in the middle gray scale range to be equal to a brightness value corresponding to the third gray level value on the standard brightness change curve.
The method of claim 3, further comprising:

Generating at least one adjustment curve according to grayscale values and luminance values of each of the pixels in the first grayscale range, the intermediate grayscale range, and the second grayscale range;

The driving voltage of the liquid crystal display in the vertical alignment driving mode is controlled according to the grayscale value and the luminance value in the adjustment curve used.
The method according to any one of claims 1 to 4, further comprising: adjusting a red saturation of each of said pixels in said liquid crystal display.
Display control device for liquid crystal display, characterized in that it can be based on standard brightness The change curve adjusts the brightness value corresponding to the grayscale value of each pixel in the liquid crystal display, and the device includes:

a first adjustment module, configured to adjust a brightness value corresponding to the first gray level value in the first gray level range to be lower than a brightness value corresponding to the first gray level value on the standard brightness change curve;

a second adjustment module, configured to adjust a brightness value corresponding to the second gray level value in the second gray level range to be higher than a brightness value corresponding to the second gray level value on the standard brightness change curve;

The grayscale value in the first grayscale range is smaller than the grayscale value in the second grayscale range.
The apparatus according to claim 6, wherein each grayscale value of each pixel in the liquid crystal display screen is divided into three grayscale ranges; wherein the first grayscale range includes from 0 to a first threshold a low grayscale value, the intermediate grayscale range including an intermediate grayscale value from a first threshold to a second threshold, the second grayscale range including a high grayscale value from the second threshold to the highest grayscale.
The device according to claim 7, further comprising:

And a setting module, configured to set a brightness value corresponding to the third gray level value in the middle gray scale range to be equal to a brightness value corresponding to the third gray level value on the standard brightness change curve.
The device according to claim 8, further comprising:

a curve generating module, respectively connected to the first adjusting module, the second adjusting module, and the setting module, configured to: in the first grayscale range, the intermediate grayscale range, and the second gray according to each of the pixels a gray scale value and a brightness value within the range, generating at least one adjustment curve;

The driving module is connected to the curve generating module, and is configured to control a driving voltage of the liquid crystal display in the vertical alignment driving mode according to the grayscale value and the brightness value in the adopted adjustment curve.
The apparatus according to any one of claims 6 to 9, further comprising:

The saturation adjustment module adjusts the red saturation of each of the pixels in the liquid crystal display.