Liquid crystal display device

• US 6,876,347 B2
• Filed: 09/26/2001
• Issued: 04/05/2005
• Est. Priority Date: 09/27/2000
• Status: Expired due to Term

• Current Assignee: Trivale Technologies, LLC (Vector Capital Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Takahashi, Seiki, Tashiro, Tomohiro, Miyake, Shiro
• Primary Examiner(s): WU, XIAO MIN
• Application Number:
  US09/962,599
• Publication Number:
  US 20020057249A1
• Time in Patent Office: 1,287 Days
• Field of Search: 345/87, 345/88, 345/89, 345/95, 345/96, 345/97, 345/98, 345/99, 345/100, 345/101, 345/690, 345/208, 345/209, 345/210
• US Class Current: 345/87
• CPC Class Codes: G09G 3/18 using liquid crystals
• CPC Class Codes: G09G 3/2011 by amplitude modulation
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers

Abstract

In a liquid crystal display device of the invention, a reference voltage having a maximum value higher than a maximum value of a signal voltage used for obtaining a predetermined liquid crystal application voltage-luminance characteristic and a minimum value lower than a minimum value of the signal voltage is formed, and a liquid crystal driving circuit forms a correction voltage to speed up a response of a liquid crystal element from this reference voltage, so that the speed of the response of the liquid crystal element is made high even at the time of change from a gray level to white or black.

Claims

1. A liquid crystal display device for displaying an image based on an image signal, comprising:

a display unit including liquid crystal and having predetermined liquid crystal applied voltage-luminance characteristics, in which a luminance according to the image data varies depending on a liquid crystal applied voltage applied to the display unit; and

a signal line drive circuit that is selectively inputted with a first reference voltage used for supplying the liquid crystal applied voltage to the display unit, and a second reference voltage having a maximum value larger than a maximum value of the liquid crystal applied voltage and a minimum value smaller than a minimum value of the liquid crystal applied voltage;

supplies the liquid crystal applied voltage to the display unit based on the first reference voltage; and

when the liquid crystal applied voltage is changed to the maximum value or the minimum value, supplies a correction voltage to the display unit based on the second reference voltage for speeding up a response of the liquid crystal, the correction voltage being higher than the maximum value or lower than the minimum value of the liquid crystal applied voltage.

2. The liquid crystal display device according to claim 1, wherein the signal line drive circuit includes a terminal to which the second reference voltage is inputted and a terminal to which a control signal to select one of the first reference voltage and the second reference voltage is inputted.

3. The liquid crystal display device according to claim 1, wherein a value of the second reference voltage is selected such that when the liquid crystal applied voltage is changed to the maximum value or the minimum value, the luminance corresponding to the liquid crystal applied voltage is not distorted.

4. The liquid crystal display device according to claim 2, wherein a value of the second reference voltage is selected such that when the liquid crystal applied voltage is changed to the maximum value or the minimum value, the luminance corresponding to the liquid crystal applied voltage is not distorted.

5. The liquid crystal display device according to claim 1, wherein the correction voltage is supplied before the liquid crystal applied voltage corresponding to the image signal is supplied.

6. The liquid crystal display device according to claim 2, wherein the correction voltage is supplied before the liquid crystal applied voltage corresponding to the image signal is supplied.

7. The liquid crystal display device according to claim 3, wherein the correction voltage is supplied before the liquid crystal applied voltage corresponding to the image signal is supplied.