LIQUID CRYSTAL DISPLAY DEVICE, AND METHOD AND CIRCUIT FOR DRIVING FOR LIQUID CRYSTAL DISPLAY DEVICE

• US 20100007637A1
• Filed: 09/21/2009
• Published: 01/14/2010
• Est. Priority Date: 12/26/2003
• Status: Active Grant

• Current Assignee: NLT Technologies, Ltd.
• Original Assignee: NEC Corporation
• Inventors: Takatori, Kenichi
• Granted Patent: US 8,274,465 B2
• Time in Patent Office: Days
• US Class Current: 345/204
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 2340/16 Determination of a pixel data signal depending on the signal applied in the previous frame
• CPC Class Codes: G09G 3/3655 Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors

Abstract

A liquid crystal display device includes a display section, an image signal drive circuit, a scan signal drive circuit, a common electrode potential control circuit, and a synchronous circuit. The display section has scan electrodes, image signal electrodes, a plurality of pixel electrodes arranged in a matrix, a plurality of switching elements for transmitting an image signal to the pixel electrodes, and a common electrode. The common electrode potential control circuit changes an electric potential of the common electrode into a pulse shape, after the scan signal drive circuit has scanned all the scan electrodes and the image signal has been transmitted to the pixel electrodes. Otherwise, the image signal is overdriven. Otherwise, torque for returning to a no-voltage-application state is increased.

Claims

1. A liquid crystal display device comprising a display section, an image signal drive circuit, a scan signal drive circuit, an electrode potential control circuit, and a synchronous circuit wherein

the display section includes:

a twisted nematic liquid crystal having a response speed faster than one frame interval;

scan electrodes which are scanned by the scan signal drive circuit;

image signal electrodes which are driven by the image signal drive circuit;

a plurality of pixel electrodes arranged in a matrix;

a plurality of switching elements for transmitting an image signal of the image signal electrodes to the pixel electrodes; and

a storage capacitor electrode to be controlled by the electrode potential control circuit,

the electrode potential control circuit changes an electric potential of the storage capacitor electrode into a pulse shape, after the scan signal drive circuit has scanned all the scan electrodes and the image signal has been transmitted to the pixel electrodes, and

the electric potential of the storage capacitor electrode changed into the pulse shape is an electric potential that does not reset the display of the display section.

2. The liquid crystal display device according to claim 1, further comprising a common electrode potential control circuit wherein

the display section further includes common electrodes which are controlled by the common electrode potential control circuit,

the common electrode potential control circuit changes an electric potential of the common electrode into a pulse shape, after the scan signal drive circuit has scanned all the scan electrodes and the image signal has been transmitted to the pixel electrodes, and

the electric potential of the common electrode changed into the pulse shape is an electric potential that does not reset the display of the display section.

3. The liquid crystal display device according to claim 2,

wherein the electric potentials of the image signal differ from an electric potential of an image signal in a stable display state during static drive, in consideration of response characteristic of the display section during electric charge hold driving.

4. The liquid crystal display device according to claim 3, wherein;

the image signal is divided into a plurality of color image signals corresponding to a plurality of colors,

light sources which correspond to the plurality of colors are synchronized with the plurality of color image signals with a predetermined phase difference, and

the plurality of color image signals, being in a color field sequential (color time division) method, are successively displayed with time.

5. The liquid crystal display device according to claim 1, wherein;

the electric potential of the storage capacitor electrode changes among at least four potentials within one frame.

6. The liquid crystal display device according to claim 5, wherein;

the electric potential of the common electrode changes among at least four potentials within one frame.

7. The liquid crystal display device according to claim 1, wherein a relation of p/d<

8 is established between a twist pitch p (μ

m) of the twisted nematic liquid crystal and an average thickness d (μ

m) of the twisted nematic liquid crystal.

8. The liquid crystal display device according to claim 1, wherein;

the twisted nematic liquid crystal is polymerically stabilized to have a structure which is almost continuously twisted.