HD66787 Datasheet, PDF(119/159 Page) Renesas Technology Corp – 528-channel, One-chip Driver with 262,144-color Display RAM and Power Supply Circuit for Low-temperature Poli-Si TFT (LTPS-TFT) Panels with Incorporat

English

English German Russian Spanish Italian Polish Chinese Japanese Korean French Portuguese	Language :

HD66787 Datasheet, PDF (119/159 Pages) Renesas Technology Corp – 528-channel, One-chip Driver with 262,144-color Display RAM and Power Supply Circuit for Low-temperature Poli-Si TFT (LTPS-TFT) Panels with Incorporat

◁

HD66787

Preliminary

Î³-Correction Register

The Î³-adjustment register is a group of registers to set an appropriate grayscale voltage for the Î³-

characteristics of a liquid crystal panel. The register group is categorized into the ones adjusting gradient,

amplitude, and fine-tuning in relation to grayscale number and grayscale voltage characteristics. Each

are common to both polarities.

Grayscale number

Gradient adjustment

Grayscale number

Amplitude adjustment

Grayscale number

Fine adjustment

Gradient, Amplitude, Fine Adjustments

1. Gradient adjustment registers

The gradient adjustment registers are used to adjust the gradient around the middle of the grayscale number

and voltage characteristics without changing a dynamic range. To adjust a gradient, the values of the

variable resistors (VRHP (N)/VRLP (N)) in the ladder resistor block for grayscale voltage generation are

controlled. The registers incorporate separate registers for positive and negative polarities to be compatible

with asymmetric drive.

2. Amplitude adjustment registers

The amplitude adjustment registers are used to adjust the amplitude of the grayscale voltage. To adjust the

amplitude, the values of the variable resistors (VRP(N)1/0) in the bottom of the ladder resistor block for

grayscale voltage generation are adjusted. Same with the gradient registers, the amplitude adjustment

registers also incorporate separate registers for positive and negative polarities.

3. Fine adjustment registers

The fine adjustment register is to fine-adjust the grayscale voltage level. To fine-adjust the grayscale

voltage level, each level of 8-level reference voltages generated from the ladder registers is controlled by 8-

to-1 selector. Same with the other registers, the fine adjustment registers also incorporate separate registers

for positive and negative polarities.

Rev.0.22, May.23.2003, page 119 of 159

▷