IP Library Granted Patent US 8,072,405
Granted Patent B2
US 8,072,405 · App. 12/385,936 · Granted Dec 6, 2011

Liquid crystal display device

Assignee: Hitachi Displays, Ltd.
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Quick Facts
Patent No.
US 8,072,405
App. No.
12/385,936
Granted
Dec 6, 2011
Kind
B2
Abstract

The present invention provides a liquid crystal display device which can recover a charge stored in a liquid crystal display panel without using an exteriorly mounted part such as a coil thus achieving the low power consumption. A display device includes a liquid crystal display panel having a plurality of pixels, a plurality of video lines which apply a video voltage to the plurality of pixels, and a drive circuit which supplies the video voltage to the plurality of video lines. In such a display device, the liquid crystal display panel has a common electrode to which a first voltage and a second voltage having a potential higher than a potential of the first voltage are alternately applied. The liquid crystal display panel further includes a charge recovering circuit which is connected between the respective video lines and a power source line and recovers charge when a voltage applied to the common electrode is changed over from the first voltage to the second voltage or when the voltage applied to the common electrode is changed over from the second voltage to the first voltage.

Claims (25)

1. A liquid crystal display device comprising;

a liquid crystal display panel having a plurality of pixels;

a plurality of video lines which apply a video voltage to the plurality of pixels; and

a drive circuit which supplies the video voltage to the plurality of video lines,

wherein the liquid crystal display panel has a common electrode to which a first voltage and a second voltage having a potential higher than a potential of the first voltage are alternately applied,

the liquid crystal display device includes first switching elements which are connected between the respective video lines and a power source line and are turned on when a voltage applied to the common electrode is changed over from the first voltage to the second voltage,

the video voltage is supplied to the respective video lines from the drive circuit via second switching elements,

the second switching elements are turned off when the first switching elements are turned on,

diode elements are connected between the first switching elements and the power source line, and

a flow direction of an electric current in the diode elements is a direction directed from the first switching elements to the power source line.

2. A liquid crystal display device according to claim 1 , wherein the first switching elements, the diode elements and the second switching elements are arranged in the inside of the drive circuit.

3. A liquid crystal display device according to claim 1 , wherein the liquid crystal display device includes a timing controller which controls the first switching elements and the second switching elements.

4. A liquid crystal display device according to claim 1 , wherein the first switching elements, the diode elements and the second switching elements are integrally formed on a substrate on which the liquid crystal display panel is formed using thin film transistors.

5. A liquid crystal display device comprising:

a liquid crystal display panel having a plurality of pixels; a plurality of video lines which apply a video voltage to the plurality of pixels; and

a drive circuit which supplies the video voltage to the plurality of video lines,

wherein the liquid crystal display panel has a common electrode to which a first voltage and a second voltage having a potential higher than a potential of the first voltage are alternately applied,

the liquid crystal display device includes first switching elements which are connected between the respective video lines and a power source line and are turned on when a voltage applied to the common electrode is changed over from the second voltage to the first voltage,

the video voltage is supplied to the respective video lines from the drive circuit via second switching elements,

the second switching elements are turned off when the first switching elements are turned on, and

diode elements are connected between the first switching elements and the power source line, and

a flow direction of an electric current in the diode elements is a direction directed from the power source line to the first switching elements.

6. A liquid crystal display device according to claim 5 , wherein the first switching elements, the diode elements and the second switching elements are arranged in the inside of the drive circuit.

7. A liquid crystal display device according to claim 5 , wherein the liquid crystal display device includes a timing controller which controls the first switching elements and the second switching elements.

8. A liquid crystal display device according to claim 5 , wherein the first switching elements, the diode elements and the second switching elements are integrally formed on a substrate on which the liquid crystal display panel is formed using thin film transistors.

Assignments (3)
MERGER Recorded Dec 13, 2011
From: IPS ALPHA SUPPORT CO., LTD.
To: PANASONIC LIQUID CRYSTAL DISPLAY CO., LTD.
Reel/Frame 027482/0140 →
ATTACHED ARE (1) THE COMPANY SPLIT DOCUMENTS IN JAPANESE WITH ENGLISH TRANSLATION THEREOF AND (2) THE CERTIFICATE OF COMPANY SPLIT DOCUMENT IN JAPANESE WITH ENGLISH TRANSLATION, WHICH TOGETHER CONVEY 50% OWNERSHIP OF THE REGISTERED PATENTS AS LISTED IN THE ATTACHED TO EACH OF THE RECEIVING PARTIES (SEE PAGE 10, EXHIBIT 2-1, SECTION 1 OF THE ENGLISH TRANSLATION OF THE COMPANY SPLIT PLAN.) Recorded Dec 13, 2011
From: HITACHI, DISPLAYS, LTD.
To: HITACHI DISPLAYS, LTD.; IPS ALPHA SUPPORT CO., LTD.
Reel/Frame 027615/0589 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 24, 2009
From: NISHITANI, SHIGEYUKI; SATO, HIDEO
To: HITACHI DISPLAYS, LTD.
Reel/Frame 022647/0031 →
Priority Claims (1)
JP 2004-084175 · Mar 23, 2004 · national
Continuity (2)
Continuation 11066186 · Feb 25, 2005
Related Publication 20090213059A1 · Aug 27, 2009