IP Library Granted Patent US 7,319,451
Granted Patent B2
US 7,319,451 · App. 10/747,525 · Granted Jan 15, 2008

Driving circuit for use in cholesteric liquid crystal display device

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Quick Facts
Patent No.
US 7,319,451
App. No.
10/747,525
Granted
Jan 15, 2008
Kind
B2
Abstract

A liquid crystal display device of the present invention comprises: a liquid crystal display panel; a cholesteric liquid crystal layer in the liquid crystal panel; a data controller having a connection with the liquid crystal display panel, wherein the data controller receives red, green and blue data signals from an external source and provides the signals to the liquid crystal panel; and a data amplifying circuit in the data controller, the data amplifying circuit selecting one of the red, green and blue data signals and then overdriving the selected data signal.

Claims (16)

1. A liquid crystal display device, comprising:

a liquid crystal display panel;

a cholesteric liquid crystal layer in the liquid crystal display panel;

a data controller having a connection with the liquid crystal display panel, wherein the data controller receives red, green and blue data signals from an external source and provides the signals to the liquid crystal display panel; and

a data amplifying circuit in the data controller, the data amplifying circuit selecting one of the red, green and blue data signals and then overdriving the selected data signal so that the selected data signal has first and second voltage levels, wherein the first voltage level has a greater magnitude that the second level voltage.

2. The device according to claim 1 , further comprising a timing controller generating an H-synchronization signal and providing the H-synchronization signal to the liquid crystal display panel.

3. The device according to claim 1 , wherein the data amplifying circuit selects the red data signal.

4. The device according to claim 1 , wherein the data amplifying circuit overdrives the red data signal.

5. The device according to claim 1 , wherein the data amplifying circuit provides a voltage having a step profile.

6. The device according to claim 1 , wherein the first voltage level has a duration approximately equal to a response time of the cholesteric liquid crystal.

7. A method for improving the brightness and color display of a reflective liquid crystal display device having a cholesteric liquid crystal color layer comprising:

determining a subpixel color having a weaker reflectivity than another subpixel color; and

overdriving a voltage to the subpixel color having the weaker reflectivity, wherein overdriving the voltage includes steps of amplifying the subpixel data signal corresponding to the subpixel color having a weaker reflectivity and converting the subpixel data signal into two voltage signals, wherein the two voltage signals include different magnitudes.

8. The method of claim 7 , wherein a second voltage signal of the two voltage signals is substantially the same as the voltage for driving the subpixels corresponding to the other subpixel color.

9. The method of claim 7 , wherein a duration of the first voltage signal is substantially equal to the response time of the liquid crystal.

10. The method of claim 7 , wherein a magnitude of a first voltage is greater than a magnitude of a second voltage.

Assignments (2)
CHANGE OF NAME Recorded Oct 17, 2008
From: LG.PHILIPS LCD CO., LTD.
To: LG DISPLAY CO., LTD.
Reel/Frame 021763/0177 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 30, 2003
From: KIM, MUN-CHUL
To: LG.PHILIPS LCD CO., LTD.
Reel/Frame 014855/0796 →