KR20060084718A - Apparatus for lcd response time improvement using frame difference and piece-wise linear function - Google Patents

Abstract

The present invention relates to a technique for improving the response speed of an LCD by using a frame difference and an interval linear function in various display devices using an LCD panel. The present invention includes an RGB / YUV conversion unit for converting an RGB color signal into a YUV color signal; A frame memory controller which stores the Y signal in a frame memory and simultaneously transmits the Y signal to the LCD response speed improving unit along with the Y signal of a previous frame; A response speed improving unit for extracting a parameter for calculating a section linear function using the two Y signals and a predetermined parameter, determining a section using the same, and obtaining an overdriven Y signal; An interval linear parameter extracting unit for generating new parameters using the parameters and luminance signals received from the outside of the system and transferring the external input parameters to the pixel overdriving unit; A pixel overdriver configured to determine a section using the received luminance signal and a parameter, perform an operation according to the determined section, and output an overdriven pixel according to the section; A YUV / RGB conversion unit converts the overdriven Y signal and U, V signal into an RGB color signal to obtain an overdriven output RGB color signal.

Description

 LCD response speed improvement device using frame difference and interval linear function {APPARATUS FOR LCD RESPONSE TIME IMPROVEMENT USING FRAME DIFFERENCE AND PIECE-WISE LINEAR FUNCTION}

1 is a block diagram of a device for improving the response speed of the LCD according to the prior art.

2 is a block diagram of an apparatus for improving a response speed of an LCD using a frame difference and an interval linear function.

3 is an explanatory diagram of operations of the frame memory and the frame memory controller in FIG. 2;

4 is an operation explanatory diagram of a response speed improving unit in FIG. 2;

FIG. 5 is an explanatory diagram of the section linear parameter extractor in FIG. 2; FIG.

FIG. 6 is an explanatory diagram of the operation of the pixel overdriving unit in FIG. 2; FIG.

7 is an interval linear function graph.

8 (a)-(d) are waveform diagrams showing an embodiment of overdriving according to the present invention;

*** Description of the symbols for the main parts of the drawings ***

21: RGB / YUV conversion section 22: frame memory

23: frame memory control unit 24: response speed improvement unit

25: section linear parameter extraction section 22A: parameter input section

25B: Parameter calculation section 26: Pixel overdriving section

26A: section determining section 26B: overdriving calculating section

27: YUV / RGB converter

The present invention relates to a technique for improving the response speed of an LCD by using a frame difference and an interval linear function in various display apparatuses using an LCD panel. In particular, the present invention relates to a low-volume algorithm without using an additional memory other than a frame memory. The present invention relates to an apparatus for improving the response speed of an LCD using a frame difference and an interval linear function to reduce an afterimage of an LCD more efficiently.

Recently, the display technology of flat panel display (FPD) devices has been developed differently every day, and as a result, display devices using LCD panels are widely used. The reason is that the LCD panel has advantages such as low power consumption, high resolution, small volume, and low eye fatigue compared to other FPDs.

However, the slow response speed of the LCD panel is still pointed out as a disadvantage, especially when outputting a video or when the screen is a large screen, the response speed is not fast enough and the screen appears blurred.

In recent years, many LCD panel manufacturers or companies producing display devices using the same have been developing various technologies to overcome the above disadvantages. FIG. 1 shows one example.

However, in such a system, when the input image data (RGB data) has a predetermined capacity (for example, 24 bits), an additional memory having a relatively large capacity (for example, 192kb) in order to secure a storage space of the lookup table 14 therefor. Use

As described above, in the conventional CD response improving apparatus, a relatively large memory is additionally required to secure a storage space of a lookup table. There was a problem.

Accordingly, a first object of the present invention is to provide a method for efficiently reducing LCD afterimages by using a small capacity algorithm without using an additional memory other than a frame memory to improve the response speed of an LCD.

A second object of the present invention is to improve the response speed of the LCD by using a simple logical operation in hardware.

According to a first aspect of the present invention, an LCD response characteristic improving apparatus includes a color space converter, a frame memory, a frame memory controller, and a response speed improver.

According to a second aspect of the present invention, the color space converter in the first feature is composed of an RGB / YUV converter and a YUV / RGB converter.

According to a third aspect of the present invention, the response speed improving portion of the first aspect includes an interval line function parameter extracting portion and a pixel overdriving portion.

According to the fourth aspect of the present invention, the section linear function parameter extracting portion in the third aspect comprises a parameter input portion and a parameter calculating portion.

According to a fifth aspect of the present invention, the pixel overdriving portion in the third aspect is composed of a section determination section and an overdriving calculation section.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a block diagram showing an embodiment of an apparatus for improving an LCD response speed using a frame difference and an interval linear function according to the present invention. As shown therein, an RGB / YUV conversion unit converting an RGB color signal into a YUV color signal ( 21); A frame memory controller 23 for storing the Y signal in the frame memory 22 and transmitting the Y signal to the LCD response speed improving unit 24 together with the Y signal of the previous frame; A response speed improving unit 24 for extracting a parameter required for calculating a section linear function using the two Y signals and a preset parameter, determining a section using the same, and obtaining an overdriven Y signal; An interval linear parameter extracting section 25 for generating new parameters using the parameters and luminance signals received from the outside of the system and delivering external input parameters; A pixel overdrive unit 26 which determines an interval using a luminance signal and a parameter received from the interval linear parameter extractor 25, performs an operation according to the determined interval, and outputs an overdriven pixel according to the interval. Wow; A YUV / RGB converter 27 converts the overdriven Y signal and the U and V signals into an RGB color signal to obtain an overdriven output RGB color signal. 8 to be described in detail as follows.

First, the RGB color signal is converted into a YUV color signal through the RGB / YUV converter 21, and the luminance signal Y is stored in the frame memory 22, and the LCD response speed improver 24 together with the Y signal of the previous frame. To pass.

Then, the parameters are extracted using the two Y signals and the preset parameters, the interval is determined using the obtained parameters, and the overdriven Y signal is obtained. Finally, the RGB color signals are converted again using the U and V signals to obtain an overdriven output RGB color signal.

The color space converter according to the present invention converts a color signal by the following equation, where the color space converter means an RGB / YUV converter 21 and a YUV / RGB converter 27.

[Equation 1]

[Equation 2]

Equation 1 is used to convert an input RGB signal into a YUV signal, and Equation 2 is used to convert an overdriven Y signal and an unprocessed UV signal into an output RGB signal. Each parameter value of Equations 1 and 2 follows BT.601 and BT.709 of the ITU-R.

The operation of the frame memory controller 23 will now be described with reference to FIG. 3.

The frame memory control unit 23 activates the chip enable signal cen, the write enable signal wen, and the lead enable signal ren only for valid pixel data, and activates the frame memory 22. The input Y signal Yin (x, y, t) of the current frame is stored in the frame memory 22 by using an address addr, a valid signal, and a synchronized counter. t-1) is read from the frame memory 22, and finally both signals are transmitted to the response speed improving unit 24.

The operation of the response speed improving unit 24 will be described with reference to FIG. 4 as follows.

The response speed improving unit 24 is composed of a section linear parameter extracting unit 25 and a pixel overdriving unit 26. The section linear parameter extracting section 25 extracts a parameter required for the section linear function calculation and then obtains the overdriven Y signal through the calculating process in the parameter extracting section 25.

The operation of the section linear parameter extraction unit 25 will be described in more detail with reference to FIG. 5 as follows.

After receiving seven parameters (PARAM0 to PARAM6) from the outside of the system through the parameter input unit 25A, the parameter calculation unit uses Yin (x, y, t-1) and PARAM0, PARAM3, PARAM4, PARAM5, and PARAM6. A new parameter a, b, c is generated at 25B, and the external input parameters PARAM1 and PARAM2 are transferred to the pixel overdriving unit 26. At this time, all the parameters used have a value between 16 and 235, and the principles for obtaining a, b, and c are as shown in Equations 3, 2, and 3 below.

[Equation 3]

[Equation 4]

[Equation 5]

The parameters a, b and c obtained here and the input parameters PARAM1 and PARAM2 are used in the following pixel overdrive section 26. The default value of the input parameter uses PARAM0 = 50, PARAM1 = 124, PARAM2 = 194, PARAM3 = 99, PARAM4 = 149, PARAM5 = 184, PARAM6 = 210.

The operation of the pixel overdriving unit 26 will be described in more detail with reference to FIG. 6 as follows.

First, the section determination unit 26A determines the section using Yin (x, y, t), Yin (x, y, t-1), PARAM1, and PARAM2, using Equation 6 below. To determine the interval.

[Equation 6]

The overdriving operation unit 26B performs the calculation according to the five sections determined by Equation 7, and the following Equation 7 illustrates a method of outputting the overdriven pixel according to the section.

[Equation 7]

Looking at the interval linear function of Figure 7 to help understand the parameters and equations used in [Equation 7] as follows.

In the case of parameter a, the smaller the pixel value of the previous frame moves to the left, and the larger the right, the larger the pixel value in the previous frame, the smaller the pixel value of the previous frame is lower, the larger the value is, between 16 and PARAM0. The parameter c moves down between PARAM5 and PARAM6 as the pixel value of the previous frame is smaller, and the larger it is.

As a result, the movement of the parameters a, b, and c results in a much brighter light when the current frame is brighter than a pixel of the previous frame, and a darker light when the pixels of the current frame are dark, resulting in an overdriven pixel. do.

8 (a)-(d) are waveform diagrams showing an embodiment of overdriving according to the present invention. That is, if the original signals are equal to (a), (c), they are overdriven by the present invention and appear as (b), (d).

As a result, the present invention improves the response speed of the LCD by adaptively overdriving the brightness of the pixel according to the frame difference, thereby reducing the crushing of the screen appearing on the large screen or video.

As described in detail above, the present invention improves image quality without any additional cost by improving the response speed of an LCD by using a frame difference and an interval linear function without using an additional memory in addition to the frame memory in various display devices using an LCD panel. It can work.

Claims (9)

An RGB / YUV converter for converting an RGB color signal into a YUV color signal; A frame memory controller which stores the Y signal in a frame memory and simultaneously transmits the Y signal to the LCD response speed improving unit along with the Y signal of a previous frame; A response speed improving unit for extracting a parameter for calculating a section linear function using the two Y signals and a predetermined parameter, determining a section using the same, and obtaining an overdriven Y signal; An interval linear parameter extracting unit for generating new parameters using the parameters and luminance signals received from the outside of the system and transferring the external input parameters to the pixel overdriving unit; A pixel overdriver configured to determine a section using the received luminance signal and a parameter, perform an operation according to the determined section, and output an overdriven pixel according to the section; And a YUV / RGB converter configured to convert the overdriven Y signal and the U and V signals into RGB color signals to obtain an overdriven output RGB color signal. The apparatus of claim 1, wherein the RGB / YUV converter converts an RGB color signal into a YUV color signal by using Equation 1 below.

The frame memory controller of claim 1, wherein the frame memory controller activates various enable signals only for valid pixel data, and uses an address, a valid signal, and a synchronized counter of the frame memory to control the current frame. The input Y signal Yin (x, y, t) is stored in the frame memory, and the input Y signal (x, y, t-1) of the previous frame is read from the frame memory, and both signals are finally improved in response speed. An apparatus for improving a response speed of an LCD using a frame difference and a section linear function, which is configured to be transmitted to a part. The method of claim 1, wherein the interval linear parameter extraction unit A parameter input unit which receives seven parameters PARAM0 to PARAM6 from the outside of the system; By using Yin (x, y, t-1) and the parameters PARAM0, PARAM3, PARAM4, PARAM5, and PARAM6, the parameter calculator generates new parameters a, b, c and simultaneously transfers the external input parameters PARAM1, PARAM2. An apparatus for improving a response speed of an LCD using a frame difference and a section linear function, characterized by comprising a parameter calculator. The method of claim 4, wherein the parameter calculator uses the following equations (3), (4) and (5) to calculate the parameters a, b, and c. The response speed improvement device using the LCD.

The method of claim 1, wherein the pixel overdriving unit A section determination unit which determines a section using Yin (x, y, t), Yin (x, y, t-1), PARAM1, and PARAM2; And an overdriving operation unit configured to perform an operation according to the five sections determined by the section determining unit and output an overdriven pixel according to the section. The apparatus of claim 6, wherein the section determination unit uses the following Equation 6 to determine the section. 8.

The apparatus of claim 6, wherein the overdriving operation unit is based on the following Equation 7 when outputting the overdriven pixel according to the section. 8.

[4] The apparatus of claim 1, wherein the YUV / RGB converter converts the overdriven Y signal and the U and V signals into RGB color signals using Equation 2 below. LCD response speed improvement device.

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