IP Library Granted Patent US 7,701,430
Granted Patent B2
US 7,701,430 · App. 11/655,887 · Granted Apr 20, 2010

Driving circuit of display device and method of driving same

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Quick Facts
Patent No.
US 7,701,430
App. No.
11/655,887
Granted
Apr 20, 2010
Kind
B2
Abstract

There is provided a driving circuit of a liquid crystal display device capable of solving a problem of power consumption while solving a problem of time required for charge/discharge of source lines by virtue of shorting by use of precharge. The driving circuit of the liquid crystal display device comprises first shorting means, second shorting means, third shorting means, and fourth shorting means. With the use of the fourth shorting means, in particular, the source lines can be driven starting from a predetermined potential generated by a gradation voltage generation circuit, and a drive start potential is changed from a conventional common electrode potential to potentials generated by the gradation voltage generation circuit, so that power consumption can be effectively reduced (by about 8% on average as compared with the conventional case).

Claims (10)

1. A driving circuit of a liquid crystal display device driven by means of the dot inversion driving system, said driving circuit comprising:

a gradation voltage generation circuit feeding a plurality of voltages higher than a predetermined potential and a plurality of voltages lower than the predetermined potential;

a source line output part having a DA converter outputting a gradation voltage selected from the gradation voltage generation circuit according to an input signal, said source line output part outputting the gradation voltage to the respective source lines such that adjacent odd numbered columns of the source line and even numbered columns of the source line having opposite polarities each other, wherein polarities are defined based on the predetermined potential;

first shorting parts shorting the odd numbered columns of the source lines with each other;

second shorting parts shorting the even numbered columns of the source lines with each other;

a third shorting part shorting the odd numbered columns of the source lines with the even numbered columns of the source lines; and

a fourth shorting part connecting a first voltage supply line supplying a first voltage higher than the predetermined potential and a second voltage supply line supplying a second voltage lower than the predetermined potential shorting said first voltage supply line or said first voltage supply line.

2. A driving circuit of a liquid crystal display device, according to claim 1 , wherein the predetermined potential is a common electrode potential.

3. A driving circuit of a liquid crystal display device according to claim 2 , further comprises a control circuit outputting control signals for controlling the first shorting parts, the second shorting parts, the third shorting part, and the fourth shorting parts.

4. A driving circuit of a liquid crystal display device according to claim 3 , wherein the control circuit activating the forth shorting parts after that activating the first shorting parts when the gradation voltage supplied the odd numbered columns of the source lines, going over the opposite polarity.

Assignments (2)
CHANGE OF NAME Recorded Mar 21, 2014
From: OKI SEMICONDUCTOR CO., LTD
To: LAPIS SEMICONDUCTOR CO., LTD.
Reel/Frame 032495/0483 →
CHANGE OF NAME Recorded Dec 24, 2008
From: OKI ELECTRIC INDUSTRY CO., LTD.
To: OKI SEMICONDUCTOR CO., LTD.
Reel/Frame 022052/0797 →