Gamma voltage generating device, liquid crystal display device and method for controlling gamma voltage

Abstract

A gamma voltage generator is used in a liquid display device and comprises a voltage division circuit coupled between a first voltage and a second voltage and used to generate a gamma voltage, wherein the voltage division circuit comprises a zero order gamma voltage output end of the gamma voltage used to output liquid crystal pixel unit zero order gray scale as well as a voltage division elementconnected in series inside the voltage division circuit; and both end parts of the voltage division element are respectively connected with the zero order gamma voltage output end through a switchingelement. The invention also provides a method and a liquid crystal display device for controlling the gamma voltage. The gamma voltage generator not only can increase liquid crystal response time, but also ensures that liquid crystal has better image display effect.

Description

technical field [0001] The invention relates to the field of liquid crystal technology, in particular to a gamma voltage generating device, a liquid crystal display device and a method for controlling the gamma voltage. Background technique [0002] The gray scale performance of LCD is managed by the source driver inside the display. The so-called "gray scale" refers to the level of brightness. Each point seen on the LCD screen is a pixel, which is composed of three sub-pixels of red, green, and blue (RGB). Each sub-pixel shows The different brightness levels are called "grayscale". In order to change the color of the picture, it is necessary to control the brightness and darkness of the three sub-pixels of RGB to adjust different colors. For example, in a 6bit panel, "6bit" means that each sub-pixel can display 2 to the 6th power of different levels of brightness, which is called 64 gray levels. Therefore, if each sub-pixel R, G, and B is controlled by 6-bit binary data,...

AI Technical Summary

Problems solved by technology

[0008] However, these grayscale images obtained through FRC will cause some image interference due to complex digital-to-analog conversion, especially when the analog voltage difference is relatively large, the interference will be more serious

Now, a larger black voltage is usually applied in the dark state to increase the response time of the liquid crystal from non-zero grayscale to zero-level grayscale, such as Figure 5 and 6 As shown, when the voltage is from 0V to 1.4V, the brightness transmittance is basically the same, resulting in a change from the full black gray scale L0 (or called zero-level gray scale) to the next gray scale L1 (or called one-level gray scale). ) voltage VL0-L1 must be greater than 1.4V, so that the gamma voltage difference between L0 (full black) and its adjacent gray level L1 is very large, causing serious FRC interference

However, if the gamma voltage of L0 is only reduced to reduce the voltage difference between L0 and its adjacent gray level L1, the response time of the liquid crystal will be slowed down.

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