CN100580762C - Driving method of color-sequence liquid crystal display backlight source - Google Patents

Abstract

The present invention provides a method for driving a backlight source of a color sequential liquid crystal display, wherein the backlight source is composed of a first light source, a second light source and a third light source having different colors, and the method comprises: lighting the three light sources in sequence, and in one frame time, the first and second light sources are lit twice, and the third light source is lit once. The present invention can solve the chromaticity difference of displaying moving objects.

Description

Driving method for backlight source of color sequential liquid crystal display

technical field

The invention relates to a driving method of a liquid crystal display, in particular to a driving method of a backlight source of a color sequential liquid crystal display.

Background technique

According to the display method of the color image, generally, the driving method of the liquid crystal display can be divided into two types: a color filter driving method and a color sequence driving method. The color sequence driving method uses the phenomenon of persistence of vision of the human eye to sequentially synthesize color images in a short period of time using the three primary color fields, that is to say, in the same pixel, the chromaticities of the three primary colors are sequentially divided into three In different display periods (frames), due to the influence of the persistence of vision of the human eye, three primary colors with different light intensities overlap within 1/60 second to obtain a color display effect. Since the color sequence method is to turn on the backlights of the three primary colors in three different display periods in sequence, when the screen displays a moving object, there will be differences in the chromaticity at the head and tail of the object, that is, the color Separation (color breakup) phenomenon, which affects the display quality. When a white object moves from right to left, human eyes will chase the moving object, but due to the effect of persistence of vision, a smear with red front and blue rear will be left on the retina.

As shown in Figure 4, a white object occupies the pixel position from m to m+7 on the screen, as shown in the abscissa in the chart. Because the screen displays the backlight in a color sequence method, it displays different colors in the chart at different time points. Y-axis. At the time point of the R frame in the N+1th frame, the eye retina accumulates the previously seen image to obtain a white object with reddish front and blue rear end.

Therefore, how to solve the above-mentioned problems becomes the goal to be pursued.

Contents of the invention

The object of the present invention is to solve the chromaticity difference of displaying moving objects by proposing a color sequence driving method.

According to the above object, the present invention proposes a method for driving a backlight source of a color sequential liquid crystal display, wherein the backlight source is composed of three light sources with different colors, such as a first light source, a second light source and a third light source, and the method includes : Turn on the three light sources in sequence, and in one frame time, the first and second light sources are turned on twice, and the third light source is turned on once.

In the backlight driving method described above, the step of sequentially lighting up the three light sources includes: sequentially lighting up the first light source, lighting up the second light source, lighting up the third light source, lighting up the second light source The second light source and the first light source are turned on.

The backlight driving method described above, wherein the time length of the third light source being turned on is less than twice the time length of the first light source being turned on, but longer than the time length of the first light source being turned on.

The backlight driving method above, wherein the duration of the third light source being turned on is less than twice the duration of the second light source being turned on, but longer than the duration of the second light source being turned on.

The above-mentioned backlight driving method, wherein in the step of turning on each of the three light sources, it also includes: writing the corresponding color data; driving the liquid crystal to rotate according to the corresponding color data; and turning on the corresponding color A source of data.

In the method for driving a backlight source as described above, the colors of the first light source, the second light source and the third light source are red, green and blue respectively.

The present invention also proposes a method for driving a backlight source of a color sequential liquid crystal display, wherein the backlight source is composed of a first light source, a second light source, and a third light source with different colors, and the method includes:

Turn on the three light sources in sequence, and in one frame time, the first light source and the second light source are turned on twice, the third light source is turned on once, and the time when the third light source is turned on The length is less than twice the time length of the first light source or the second light source being turned on, but greater than one time the time length of the first light source or the second light source is turned on.

The backlight driving method described above, wherein sequentially turning on the three light sources includes: sequentially turning on the first light source, turning on the second light source, turning on the third light source, turning on the second light source and turn on the first light source.

In the above-mentioned backlight driving method, wherein the step of turning on each of the three light sources further includes: writing corresponding color data; driving the liquid crystal to rotate according to the corresponding color data; and turning on the corresponding The light source for the color data.

In the method for driving the backlight as described above, the colors of the first light source, the second light source and the third light source are red, green and blue respectively.

The invention can solve the chromaticity difference in displaying moving objects.

Description of drawings

FIG. 1 depicts a driving schematic diagram of a color sequence driving method according to an embodiment of the present invention.

FIG. 2 depicts a timing diagram of turning on the backlight of a moving object as it moves across the display, according to an embodiment of the present invention.

FIG. 3 depicts a time diagram of human eyes feeling that the backlight is turned on when a moving object moves on a display according to an embodiment of the present invention.

Fig. 4 depicts the color map perceived by human eyes when a moving object moves on a display in the traditional color sequence method.

Wherein, the reference signs are explained as follows:

301: Addressing interval 302: Waiting interval

303: Light up the interval

Detailed ways

The present invention solves the above-mentioned problem of different chromaticity at the head and tail of a moving object by increasing the lighting frequency of red (R), green (G) and blue (B) backlights in one frame. The technical content and features of the present invention will be described below with preferred embodiments, please refer to the corresponding drawings. Like parts are denoted with like reference numerals in the drawings and detailed description.

As shown in Figure 1, in the embodiment of the present invention, each frame includes six sub-frames, including two red sub-frames (R-SF), two green sub-frames (G-SF) and two blue sub-frames (G-SF) The color sub-frame (B-SF) is used to display red (R) signal, green (G) signal and blue (B) signal respectively. In other words, within 1/60 second of a frame, the colors of six sub-frames overlap to obtain a color display effect. In addition, in this embodiment, the third sub-frame and the fourth sub-frame in one frame will turn on the backlight of the same color, so they can be combined into one sub-frame; for example, the two sub-frames shown in FIG. 1 Adjacent blue sub-frames (B-SF) constitute a sub-frame.

As shown in FIG. 1 , each sub-frame has three intervals: the first interval is the addressing interval 301, which is used to write data into this frame; the second interval is the waiting interval 302, which is the response time of the liquid crystal; The third interval is the lighting interval 303, which is used to turn on the corresponding backlight. According to this embodiment, the third sub-frame and the fourth sub-frame in one frame will turn on the backlight of the same color. For example, in this embodiment, the blue backlight is continuously turned on in the third sub-frame and the fourth sub-frame. However, in other embodiments, the backlights of other colors may also be continuously turned on. Therefore, in this embodiment, since the blue backlight is continuously on, the addressing interval and the waiting interval only need to be used once, so the addressing interval 301 and the waiting interval 302 can be saved once. In addition, since the addressing interval 301 and the waiting interval 302 are reduced once, the turn-on time of the blue backlight needs to be less than twice the turn-on time of the green backlight (or red backlight), but greater than twice the turn-on time of the green backlight (or red backlight). bright time.

FIG. 2 is a time diagram depicting the turn-on time of the three-color backlight when an object moves on the display according to an embodiment of the present invention, wherein the horizontal axis is the pixel position, and the vertical axis is the frame time. Here it is assumed that the image size of the moving object is eight pixels, the display color is white, and the white object moves six pixels in each frame time. According to the above assumptions, in the (N-1)th frame, at the pixel positions (m) to (m+7), the lighting sequence of the backlight is as follows: turn on the red backlight in the red subframe (R-SF), The green backlight is turned on in the green subframe (G-SF), the blue backlight is turned on in the blue subframe (B-SF), the green backlight is turned on in the green subframe (G-SF), and finally in the red subframe ( R-SF) lights up the red backlight. Similarly, in the (N) frame, at the pixel positions (m+6) to (m+13), the lighting order of the backlights is: turn on the green backlight in the green sub-frame (G-SF), turn on the blue backlight The blue backlight is turned on in the sub-frame (B-SF), the red backlight is turned on in the red sub-frame (R-SF), the blue backlight is turned on in the blue sub-frame (B-SF), and finally in the green sub-frame ( G-SF) lights up the green backlight. Through the effect of the persistence of vision of the human eye, the three colors are overlapped within 1/60 second, and the color display effect can be obtained.

When the human eye moves an object on the display, the eyes will follow the object, and in each pixel, the red (R), green (G) and blue (B) primary color backlights are sequentially lit, causing human The image seen by the eyes is shown in Figure 3, where the horizontal axis is the pixel position, and the vertical axis is the frame time. In the (N-1)th frame, the red display data is displayed in the red sub-frame (R-SF) at the pixel positions from (m) to (m+7). Since the visual focus of the human eye will follow the movement of the object, it makes The red display data in the red sub-frame (R-SF) lags behind the perception of human eyes. In the green sub-frame (G-SF), since the visual focus of the human eye moves forward, the green display data will lag behind the red display data in terms of human perception. In the blue sub-frame (B-SF), since the visual focus of the human eye moves forward, the blue display data will lag behind the green display data in terms of human perception. The rest of the display data situations can be deduced by analogy.

In this embodiment, each frame is divided into five sub-frames, so in each frame time, the red (R), green (G) and blue (B) primary color backlights are respectively lit twice, and Through the effect of the persistence of vision of the human eye, the three colors are overlapped to obtain a color display effect. As the frequency of turning on the backlight is accelerated, each color backlight can appear twice in one frame, so that the three primary colors can overlap in the pixel area from (m-6) to (m+7), and a color display effect can be obtained (as shown in Figure 3 of the present embodiment).

In addition, in this embodiment, the third sub-frame and the fourth sub-frame in one frame will turn on the backlight of the same color, so operations can be performed for one sub-frame, so only one addressing interval and waiting time are required interval. Compared with the traditional double frame rate (double frame rate), the present invention actually only needs five sub-frames in one frame, and can have the effect of the traditional double frame rate (double frame rate) six sub-frames. Since only five sub-frames are required, the time for turning on the backlight once can be saved, and this increased time can be used as a waiting interval to increase the time for waiting for the liquid crystal to respond. On the other hand, the present invention can also improve the problem of color separation.

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

Claims (10)

1. A method for driving a backlight source of a color sequential liquid crystal display, wherein the backlight source is composed of a first light source, a second light source and a third light source with different colors, the method comprising: The three light sources are turned on in sequence, and in one frame time, the first light source and the second light source are turned on twice, and the third light source is turned on once. 2. The backlight driving method according to claim 1, wherein the step of turning on the three light sources in sequence comprises: turning on the first light source, turning on the second light source, and turning on the third light source in sequence , turning on the second light source and turning on the first light source. 3. The backlight source driving method as claimed in claim 2, wherein the time length of the third light source being turned on is less than twice the time length of the first light source being turned on, but greater than the time length of the first light source being turned on length. 4. The backlight source driving method as claimed in claim 2, wherein the time length of the third light source being turned on is less than twice the time length of the second light source being turned on, but greater than the time length of the second light source being turned on length. 5. The backlight source driving method as claimed in claim 2, wherein in the step of lighting each of the three light sources, further comprising: Write the corresponding color data; driving the liquid crystal to rotate according to the corresponding color data; and A light source corresponding to the corresponding color data is turned on. 6. The backlight driving method as claimed in claim 1, wherein the color of the first light source is red, the color of the second light source is green, and the color of the third light source is blue. 7. A method for driving a backlight source of a color sequential liquid crystal display, wherein the backlight source is composed of a first light source, a second light source and a third light source with different colors, the method comprising: Turn on the three light sources in sequence, and in one frame time, the first light source and the second light source are turned on twice, the third light source is turned on once, and the time when the third light source is turned on The length is less than twice the time length of the first light source or the second light source being turned on, but greater than one time the time length of the first light source or the second light source is turned on. 8. The backlight driving method as claimed in claim 7, wherein turning on the three light sources in sequence comprises: turning on the first light source, turning on the second light source, turning on the third light source, and turning on the third light source in sequence. Turn on the second light source and turn on the first light source. 9. The backlight source driving method as claimed in claim 8, wherein in the step of turning on each light source in the three described light sources, further comprising: Write the corresponding color data; driving the liquid crystal to rotate according to the corresponding color data; and A light source corresponding to the corresponding color data is turned on. 10. The backlight driving method as claimed in claim 7, wherein the color of the first light source is red, the color of the second light source is green, and the color of the third light source is blue.

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