CN101202016A - Display and contrast control method thereof - Google Patents

Abstract

The invention discloses a contrast control method of a display, which comprises the following steps: firstly, the brightness distribution proportion of an image signal is counted, and the backlight brightness of the display is adjusted according to the brightness distribution proportion of the image signal. Therefore, the invention can adjust the contrast of the display.

Description

Display and its contrast control method

technical field

The present invention relates to a display, and in particular to a display capable of automatically adjusting the contrast of a display screen.

Background technique

It is an era of 3C, that is, the era of computers, communications, and consumer electronics. In such a life, there are many information devices on the market, such as mobile phones, PDAs, GPS, digital cameras and monitors. In most information devices, flat-panel displays are used as the main communication interface.

In the past, almost all display devices were based on cathode ray tubes. In view of the advancement of semiconductor manufacturing technology in recent years, whether it is a liquid crystal display or a plasma display, it has the advantages of lightness, thinness, shortness, smallness, and low power consumption compared with traditional cathode ray tubes.

These monitors include specifications such as viewing angle, weight, power consumption, response rate, resolution, contrast, etc. Among them, contrast refers to the measurement of different brightness levels between the brightest white and the darkest black in an image. The larger the range of brightness level differences, the greater the contrast. Conversely, the smaller the brightness level difference range, the smaller the contrast. A good contrast ratio can easily display vivid, rich colors, and can support all gradations of color.

However, in the existing technology, it is quite difficult to improve the contrast alone.

Contents of the invention

The present invention provides a display that can automatically adjust the contrast.

The invention provides a contrast control method of a display, which can individually improve the contrast of the display.

To solve the above problems, the present invention provides a display including a display panel, a backlight module and a control module. Wherein, the backlight module is used to provide the display light source of the display panel, and the control module is coupled to the display panel and the backlight module to receive an image signal and count its brightness distribution ratio, and control the backlight module according to the brightness distribution ratio of the image signal to adjust the brightness of the displayed screen.

According to an embodiment of the present invention, the grayscale range of the video signal of the display includes the first sub-range, the second sub-range and the third sub-range, and the luminance distributions in the video signal belonging to the first, second and third sub-ranges The proportions are respectively a first proportion value, a second proportion value and a third proportion value.

According to an embodiment of the present invention, the control module of the display compares the magnitudes of the first, second and third proportional values. If the second ratio value is greater than the first and third ratio values, the control module controls the backlight module to provide normal mode brightness. If the first proportional value is greater than the second and third proportional values, the control module controls the backlight module to provide dimming mode brightness. If the third proportional value is greater than the first and second proportional values, the control module controls the backlight module to provide brightness in the brightening mode.

From another point of view, the present invention provides a contrast control method of a display, including counting the brightness distribution ratio of the image signal, and adjusting the backlight brightness of the display according to the brightness distribution ratio of the image signal.

According to an embodiment of the present invention, the contrast control method of the above-mentioned display, wherein the gray scale range of the video signal includes the first sub-range, the second sub-range and the third sub-range, and the video signal belongs to the first, second and third sub-ranges The brightness distribution ratios of the sub-ranges are respectively a first ratio value, a second ratio value and a third ratio value.

According to an embodiment of the present invention, the comparison control method of the above-mentioned display further includes comparing the magnitudes of the first, second and third proportional values. If the second proportional value is greater than the first and third proportional values, the brightness of the backlight of the display is adjusted to the normal mode brightness. If the first proportional value is greater than the second and third proportional values, the brightness of the backlight of the display is adjusted to be the brightness of the dimming mode. If the third proportional value is greater than the first and second proportional values, the brightness of the backlight of the display is adjusted to the brightness of the brightening mode.

When the display of the present invention receives an image signal, it will count the brightness distribution ratio thereof. Then, according to the brightness distribution ratio of the image signal, the backlight brightness of the display is adjusted through the backlight module. Therefore, the contrast size can be individually adjusted by the present invention.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, preferred embodiments are specifically cited below and described in detail with accompanying drawings.

Description of drawings

FIG. 1 is a circuit diagram of a display according to a preferred embodiment of the present invention.

Fig. 2 is a brightness distribution diagram of the present invention.

FIG. 3 is another brightness distribution diagram of the present invention.

FIG. 4 is a step diagram of a comparative control method of a display according to a preferred embodiment of the present invention.

Detailed ways

FIG. 1 is a circuit diagram of a display according to a preferred embodiment of the present invention. Referring to FIG. 1 , the display 100 of this embodiment includes a display panel 103 , a backlight module 107 and a control module 105 . Wherein, the backlight module 107 is used to provide the display light source required by the display panel 103 , and the control module 105 generates a control signal to the backlight module to adjust the brightness of the display screen through the backlight module 107 . In addition, the control module 105 also transmits the image signal to the display panel 103 to generate a display image.

In this embodiment, the display panel may be a liquid crystal display panel. As is well known, a display panel includes not only scan lines, but also data lines vertically arranged to the scan lines, and pixel units arranged at intersections of each scan line and the data line. In order to avoid confusing the spirit of the present invention, this embodiment does not disclose it. However, those skilled in the art should know that there are other components in the display panel, and the present invention will not repeat them here. In addition, the backlight module of this embodiment can be implemented by a cold cathode lamp and a corresponding driving circuit, or a light emitting diode and a corresponding driving circuit.

Fig. 2 is a brightness distribution diagram of the present invention. Please refer to FIG. 2 . In this embodiment, when the display 100 receives an image signal, it will make a statistical luminance distribution map for the image data through programs, circuits or other methods. In this embodiment, the gray scale range is from the 0th level to the 250th level, and 25th level is used as a unit. Therefore, it can be divided into 100 areas A1-A100 in total, and then the luminance distribution ratio of the number of pixels belonging to a certain area to the total number of pixels in each area is counted respectively in a picture frame of the image signal. For example, when the total number of pixels in a picture frame of the image signal is 600*800=480000, and the number of pixels whose brightness belongs to the 0th to 25th level in the picture frame is 500, then the brightness distribution ratio is about 0.1 %. It is worth noting that, in this embodiment, any image signal, the grayscale range of the luminance distribution diagram is from the 0th level to the 250th level.

However, those skilled in the art should know that the grayscale range of this embodiment is not limited to the 0th to the 250th level, and the number of grayscale ranges can be set according to the needs. In addition, the luminance distribution map of this embodiment is not limited to 50 steps as a unit and divided into 50 regions. Those skilled in the art can increase or decrease the number of divisions on the luminance distribution map according to their needs.

FIG. 3 is another brightness distribution diagram of the present invention. Referring to FIG. 3 , in this embodiment, for convenience of description, the gray scale range is divided into three ranges: a first sub-range G1 , a second sub-range G2 and a third sub-range G3 . Among them, the gray scale range contained in the first sub-range G1 is from the 0th level to the 50th level, the gray scale range contained in the second sub-range G2 is from the 51st level to the 200th level, and the gray scale range contained in the third sub-range G3 is The order range is from the 201st order to the 250th order.

Please refer to Figure 1 and Figure 3 together. If the brightness distribution ratio of the first sub-range G1 is 60%, the brightness distribution ratio of the second sub-range G2 is 30%, and the brightness distribution ratio of the third sub-range G3 is 10. %, it means that the screen of the video signal is dark. Therefore, the control module 105 generates a control signal to the backlight module 107, so that the backlight module 107 provides dimming mode brightness to the display panel, thereby improving the contrast of the display image.

If the luminance distribution ratio value of the first sub-range G1 is 10%, the luminance distribution ratio value of the second sub-range G2 is 30%, and the luminance distribution ratio value of the third sub-range G3 is 60%, it means that the screen of the video signal On the bright side. Therefore, the control module 105 will generate a control signal to the backlight module 107, so that the backlight module 107 provides the brightness of the boost mode to the display panel, thereby improving the contrast of the display image.

If the luminance distribution ratio value of the first sub-range G1 is 20%, the luminance distribution ratio value of the second sub-range G2 is 60%, and the luminance distribution ratio value of the third sub-range G3 is 20%, it means that the screen of the video signal Not too bright and not too dark. Therefore, the control module 105 controls the backlight module so that the backlight module provides normal mode brightness to the display panel.

FIG. 4 is a step diagram of a comparative control method of a display according to a preferred embodiment of the present invention. Please refer to FIG. 4 , the contrast control method of the display in this embodiment includes the following steps. When the display receives an image signal, it first counts the brightness distribution ratio of the image signal (step S401 ), and the gray scale range of the image signal includes a first sub-range, a second sub-range and a third sub-range. In this embodiment, the first sub-range is the 0th to the 50th level of the gray scale range, the second sub-range is the 51st to the 200th level of the gray scale range, and the third sub-range is the 201st level of the gray scale range to level 250.

In addition, in the above gray scale range, the brightness distribution ratio of the first sub-range is the first ratio value, the brightness distribution ratio of the second sub-range is the second ratio value, and the brightness distribution ratio of the third sub-range is the third ratio value. Then, the backlight brightness of the display is adjusted according to the brightness distribution ratio of each sub-range.

When the first ratio value is greater than the second ratio value and the third ratio value, it means that the screen of the image signal is dark, therefore, adjust the brightness of the backlight of the display to the brightness of dimming mode, and improve the contrast of the display screen by reducing the brightness of the backlight effect.

When the third ratio value is greater than the first ratio value and the second ratio value, it means that the frame of the image signal is brighter. Therefore, the brightness of the backlight of the display is adjusted to the brightness of the brightening mode, thereby increasing the brightness of the backlight to achieve the effect of improving the contrast of the display screen.

When the second ratio value is greater than the first ratio value and the third ratio value, it means that the picture of the video signal is neither too bright nor too dark. Therefore, normal mode brightness is provided to the display panel.

To sum up, when the display of the present invention receives an image signal, it will count its brightness distribution ratio. Then, according to the brightness distribution ratio of the image signal, the backlight brightness of the display is adjusted through the backlight module. Therefore, the contrast size can be individually adjusted by the present invention.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection should be defined by the claims.

Claims (11)

1. A display comprising: a display panel; a backlight module for providing a display light source of the display panel; and A control module, coupled to the display panel and the backlight module, is used to receive an image signal and count its brightness distribution ratio, and control the backlight module to adjust the brightness of the display screen according to the brightness distribution ratio of the image signal. 2. The display according to claim 1, wherein the gray scale range of the video signal includes a first sub-range, a second sub-range and a third sub-range, and the video signal belongs to the first and second sub-ranges. and the brightness distribution ratios of the third sub-range are respectively the first ratio value, the second ratio value and the third ratio value. 3. The display as claimed in claim 2, wherein the first sub-range is 0-50 steps, the second sub-range is 51-200 steps, and the third sub-range is 201-255 steps. 4. The display according to claim 2, wherein the control module compares the first, second, and third proportional values; If the second proportional value is greater than the first and third proportional values, the control module controls the backlight module to provide a normal mode brightness; If the first proportional value is greater than the second and third proportional values, the control module controls the backlight module to provide a dimming mode brightness; and If the third proportional value is greater than the first and second proportional values, the control module controls the backlight module to provide a brightness in a brightening mode. 5. The display as claimed in claim 1, wherein the display panel is a liquid crystal display panel. 6. The display as claimed in claim 1, wherein the backlight module comprises a cold cathode lamp and a corresponding driving circuit. 7. The display as claimed in claim 1, wherein the backlight module comprises light emitting diodes and corresponding driving circuits. 8. A method for contrast control of a display, comprising: counting a brightness distribution ratio of an image signal; and The backlight brightness of the display is adjusted according to the brightness distribution ratio of the image signal. 9. The contrast control method of a display according to claim 8, wherein the grayscale range of the image signal includes a first sub-range, a second sub-range and a third sub-range, and the image signal belongs to the first sub-range The luminance distribution ratios of the first, second and third sub-ranges are respectively a first ratio value, a second ratio value and a third ratio value. 10. The contrast control method of a display according to claim 9, wherein the first sub-range is 0-50 steps, the second sub-range is 51-200 steps, and the third sub-range is 201-200 steps. 255 steps. 11. The display according to claim 9, wherein the step of adjusting the brightness of the backlight of the display comprises: Compare the magnitude of the first, second, and third ratio values; If the second proportional value is greater than the first and third proportional values, adjust the backlight brightness of the display to a normal mode brightness; If the first proportional value is greater than the second and third proportional values, adjusting the brightness of the backlight of the display to be a dimming mode brightness; and If the third proportional value is greater than the first and second proportional values, adjust the brightness of the backlight of the display to be a brightness in a brightening mode.

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