IP Library Granted Patent US 9,507,219
Granted Patent B2
US 9,507,219 · App. 14/938,887 · Granted Nov 29, 2016

Vertical alignment liquid crystal display device that has transistors with different switch-on resistance and method

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Quick Facts
Patent No.
US 9,507,219
App. No.
14/938,887
Granted
Nov 29, 2016
Kind
B2
Abstract

A vertical alignment liquid crystal display device (VA-LCD) includes a display panel. The display panel includes a plurality of pixels. Each pixel unit includes a first thin film transistor (TFT), a second TFT, and a liquid crystal capacitor having a pixel electrode and a common electrode. The common electrode is applied with a common voltage, a first gray voltage is applied to the pixel electrode through a first TFT, and a second gray voltage is applied to the pixel electrode through a second TFT different from the first gray voltage, such that liquid crystal capacitor maintains two different gray voltages in a display frame time of the VA-LCD.

Claims (20)

1. A liquid crystal display (LCD) device, comprising:

a display panel comprising a plurality of pixels, a plurality of data lines, and a plurality of scan lines intersecting the plurality of data lines, the plurality of scan lines and the plurality of data lines defining the plurality of pixels, a first pixel of the plurality of pixels comprising a first thin film transistor (TFT), a second TFT, a liquid crystal capacitor, a pixel electrode, and a common electrode, the first TFT and the second TFT being directly connected to the liquid crystal capacitor, wherein in the first pixel, the common electrode is electrically connected to a source of the second TFT, a drain of the second TFT is directly connected to the pixel electrode, a source of the first TFT is electrically connected to a first data line of the plurality of data lines, a drain of the first TFT is directly connected to the pixel electrode, and a switch-on resistance of the second TFT is greater than a switch-on resistance of the first TFT, and a same gate voltage is applied to the first TFT and the second TFT,

wherein in a display frame time of the LCD device, the common electrode is applied with a common voltage, and the first pixel maintains a first gray voltage and a second gray voltage, the first gray voltage being different from the second gray voltage,

wherein a plurality of grooves are formed in the pixel electrode.

2. The LCD device of claim 1 , wherein a gate of the first TFT and a gate of the second TFT are electrically connected to the plurality of scan lines.

3. The LCD device of claim 1 , wherein an absolute value of the second gray voltage is lower than that of the first gray voltage.

4. The LCD device of claim 1 , further comprising a plurality of liquid crystal molecules aligned to different orientations.

5. The LCD device of claim 4 , wherein the liquid crystal molecules are aligned to four different orientations.

6. The LCD device of claim 1 , wherein the LCD device is a multi-domain vertical alignment liquid crystal display device.

7. The LCD device of claim 1 , wherein the LCD device is a patterned vertically aligned liquid crystal display device.

8. A liquid crystal display (LCD) device, comprising: a plurality of data lines, and a plurality of scan lines intersecting the plurality of data lines, and a plurality of pixels defined by the plurality of scan lines and the plurality of data lines, a first pixel of the plurality of pixels comprising a first thin film transistor (TFT), a second TFT, a liquid crystal capacitor, a pixel electrode, and a common electrode, a source of the first TFT being connected to a first data line of the plurality of data lines, a drain of the first TFT being connected to the pixel electrode, a source of the second TFT being connected to the common electrode, a drain of the second TFT being connected to the pixel electrode, the first TFT and the second TFT being directly connected to the liquid crystal capacitor, a switch-on resistance of the second TFT being greater than a switch-on resistance of the first TFT, and a same gate voltage is applied to the first TFT and the second TFT,

wherein in a first period of a display frame time of the LCD device, one of the data lines applies a first gray voltage to the pixel electrode via the first TFT and the liquid crystal capacitor maintains the first gray voltage in the first period,

wherein in a second period of the display frame time of the LCD device, the liquid crystal capacitor discharges through the second TFT and the liquid crystal capacitor maintains a second gray voltage different from the first gray voltage in the second period,

wherein a plurality of grooves are formed in the pixel electrode.

9. The LCD device of claim 8 , wherein a gate of the first TFT and a gate of the second TFT are electrically connected to the plurality of scan lines.

10. The LCD device of claim 8 , wherein an absolute value of the second gray voltage is lower than that of the first gray voltage.

11. The LCD device of claim 8 , wherein further comprising a plurality of liquid crystal molecules aligned to different orientations.

12. The LCD device of claim 11 , wherein the liquid crystal molecules are aligned to four different orientations.

13. The LCD device of claim 8 , wherein the LCD device is a multi-domain vertical alignment liquid crystal display device.

14. The LCD device of claim 8 , wherein the LCD device is a patterned vertically aligned liquid crystal display device.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 18, 2024
From: INNOLUX CORPORATION
To: RED OAK INNOVATIONS LIMITED
Reel/Frame 069206/0903 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 12, 2015
From: CHANG, YUEH-PING; HUNG, CHAO-YI
To: INNOLUX CORPORATION
Reel/Frame 037019/0807 →