Gamma correction circuit, liquid crystal driving circuit, display and power supply circuit

Abstract

Provided is a gamma correction circuit which can deal with various gamma characteristics and can supply stable gray scale voltages while suppressing power consumption. A gamma correction resistance 401 on an input side is connected in series between input voltages (VDDR and VSS). The gamma correction resistance near the input voltages (VDDR and VSS) is a variable resistance and others are fixed resistances. The gamma correction resistance 403 on an output side is connected in series between the input voltages (VDDR and VSS). The gamma correction resistance 403 near the input voltages (VDDR and VSS) is a variable resistance and others are fixed resistances. Even when the setting of the gray scale voltages is changed by changing the gamma correction resistance on the input side, the potentials on the input side and output side of an operational amplifier can be maintained always equal and an overcurrent between the gamma correction resistance and the operational amplifier does not flow by simultaneously changing the gamma correction resistances on the output side.

Description

technical field [0001] The invention relates to a gamma correction circuit of a display device. More specifically, the present invention relates to a gamma correction circuit (γ correction circuit) and the like that generate grayscale voltages according to gamma characteristics of a display device. Background technique [0002] In recent years, with the popularization of display devices such as liquid crystal display devices and CRT displays, display devices are required to have higher display quality, higher resolution, and larger capacity. [0003] Generally, display devices such as liquid crystal display devices and CRT displays each have specific gamma characteristics, so that there is no linear proportional relationship between input (input voltage, input signal, etc.) and output (gray scale, optical transmittance, brightness, etc.) , but an exponential relationship. Therefore, in order to make a linear proportional relationship between input and output, the display d...

AI Technical Summary

Problems solved by technology

Therefore, although the structure is simple, high-precision and large-capacity displays are limited due to crosstalk caused by charge leakage from the leading pixels.

[0006] In addition, regarding the grayscale control of the passive matrix liquid crystal display device, due to its structural reasons, it is difficult to control the grayscale of each pixel. Therefore, although multiple frame periods are used as a display period, the number of ON / OFF Compared to realize frame rate control (FRC) of multi-level grayscale, and use multiple display pixels to realize high-frequency dithering display of one display grayscale (area grayscale display), etc., however, it is not conducive to realizing high resolution of displayed images rate and multi-level grayscale

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