LIQUID CRYSTAL DISPLAY DEVICE

• US 20140104151A1
• Filed: 10/10/2013
• Published: 04/17/2014
• Est. Priority Date: 10/12/2012
• Status: Abandoned Application

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: YAMAZAKI, Shunpei, MIYAKE, Hiroyuki
• Application Number:
  US14/050,931
• Publication Number:
  US 20140104151A1
• Time in Patent Office: Days
• US Class Current: 345/94
• CPC Class Codes: G09G 2300/0852 being a dynamic memory with more than one capacitor
• CPC Class Codes: G09G 2320/0214 with crosstalk due to leakage current of pixel switch in active matrix panels
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 3/3659 the addressing of the pixel involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependant on signal of two data electrodes

Abstract

A liquid crystal display device which has higher definition and reduced power consumption while its image quality is maintained is provided. A switching transistor of an active matrix liquid crystal display device is formed using a transistor having an extremely low off-state current to reduce the area of a capacitor; the capacitance value of parasitic capacitance formed by the left end of a pixel electrode and a first source line is made to be approximately the same as that of parasitic capacitance formed by the right end of the pixel electrode and a second source line; and video signals having one polarity are input to the first source line, and video signals having the other polarity are input to the second source line.

Claims

1. A liquid crystal display device comprising:

a plurality of gate lines extending in a row direction;

a plurality of source lines extending in a column direction; and

a plurality of pixels which is electrically connected to the plurality of gate lines and the plurality of source lines and is provided in a matrix,

wherein the plurality of pixels comprises;

a transistor which is electrically connected to a first gate line and a first source line and includes an oxide semiconductor; and

a pixel electrode electrically connected to the transistor,

wherein polarities of video signals input to the first source line are different from polarities of video signals input to the second source line which is provided to be adjacent to the first source line with the pixel electrode positioned therebetween, and

wherein a difference between a capacitance value of capacitance formed between the pixel electrode and the first source line and a capacitance value of capacitance formed between the pixel electrode and the second source line is greater than or equal to −

10% and smaller than or equal to 10%.

2. The liquid crystal display device according to claim 1, wherein the pixel electrode has a planar shape which is almost symmetrical about a bisector of the first source line and the second source line.

3. The liquid crystal display device according to claim 1, wherein the distance between a first wiring and an end portion of the pixel electrode on the first wiring side is approximately the same as that between a second wiring and an end portion of the pixel electrode on the second wiring side.

4. The liquid crystal display device according to claim 1,

wherein a plurality of capacitor lines is provided in a same layer as the plurality of gate lines, and

wherein in each of the pixels, a capacitance value of the capacitor including one of the capacitor lines is smaller than or equal to 30 fF.

5. The liquid crystal display device according to claim 1, wherein 300 or more of the gate lines and 300 or more of the source lines are provided in each inch.

6. The liquid crystal display device according to claim 1, wherein the oxide semiconductor has a wider band gap and a lower intrinsic carrier density than silicon.

7. A liquid crystal display device comprising:

a plurality of gate lines extending in a row direction;

a plurality of source lines having an S-shaped curve; and

a plurality of pixels which is electrically connected to the plurality of gate lines and the plurality of source lines and is provided in a matrix,

wherein the plurality of pixels comprises;

a transistor which is electrically connected to a first gate line and a first source line and includes an oxide semiconductor; and

a pixel electrode electrically connected to the transistor,

wherein a channel length direction of the transistor are provided parallel to the low direction,

wherein a difference between a capacitance value of capacitance formed between the pixel electrode and the first source line and a capacitance value of capacitance formed between the pixel electrode and the second source line is greater than or equal to −

10% and smaller than or equal to 10%.

8. The liquid crystal display device according to claim 7, wherein the pixel electrode has a planar shape which is almost symmetrical about a bisector of the first source line and the second source line.

9. The liquid crystal display device according to claim 7, wherein the distance between a first wiring and an end portion of the pixel electrode on the first wiring side is approximately the same as that between a second wiring and an end portion of the pixel electrode on the second wiring side.

10. The liquid crystal display device according to claim 7,

wherein a plurality of capacitor lines is provided in a same layer as the plurality of gate lines, and

wherein in each of the pixels, a capacitance value of the capacitor including one of the capacitor lines is smaller than or equal to 30 fF.

11. The liquid crystal display device according to claim 7, wherein 300 or more of the gate lines and 300 or more of the source lines are provided in each inch.

12. The liquid crystal display device according to claim 7, wherein the oxide semiconductor has a wider band gap and a lower intrinsic carrier density than silicon.