Method and apparatus for measuring and adjusting response time of liquid crystal display device

• US 6,828,816 B2
• Filed: 10/28/2002
• Issued: 12/07/2004
• Est. Priority Date: 12/13/2001
• Status: Expired due to Fees

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Ham, Yong Sung
• Primary Examiner(s): PERT, EVAN T
• Application Number:
  US10/281,136
• Publication Number:
  US 20030117131A1
• Time in Patent Office: 771 Days
• Field of Search: 324/601-603, 324/160, 324/161, 324/71.1, 324/770, 250/252.1, 250/206, 250/208.1, 250/208.2
• US Class Current: 324/760.01
• CPC Class Codes: G02F 1/1309 Repairing; Testing
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• 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 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A method of measuring a liquid crystal response speed includes steps of generating a sample pulse having a target voltage level and a variable voltage level that varies according to a response characteristic of a display panel, applying the sample pulse to the display panel, detecting the response characteristic of the display panel by the sample pulse, adjusting the variable voltage level until a desired level of the response characteristic is obtained, and generating modulating data representing the setting of the variable voltage level when the desired level of the response characteristic is obtained.

Claims

1. A method of measuring and adjusting a liquid crystal response speed, comprising the steps of:

generating a sample pulse having a target voltage level and a variable voltage level that varies according to a response characteristic of a display panel;

applying the sample pulse to the display panel;

detecting the response characteristic of the display panel by the sample pulse;

adjusting the variable voltage level until a desired level of the response characteristic is obtained; and

setting the variable voltage level to according to modulating data when the desired level of the response characteristic is obtained.

2. The method according to claim 1, wherein the step of detecting the response characteristic of the display panel includes steps of:

detecting a brightness of an image displayed on the display panel;

generating a voltage signal corresponding to the detected brightness;

detecting a difference of the voltage signal between two successive time periods; and

comparing the difference of the voltage signal with a desired critical value to determine if the response characteristic arrives at the desired level.

3. A liquid crystal response speed measuring and adjusting apparatus, comprising:

a pattern generator for generating a sample pulse having a target voltage level and a variable voltage level;

a display panel for receiving the sample pulse to display an image;

a response characteristic detector for detecting a varying response characteristic of the display panel by the sample pulse; and

a level controller for adjusting the variable voltage level until the response characteristic arrives at a desired level and for setting the variable voltage level according to modulating data when the desired level of the response characteristic is obtained.

4. The apparatus according to claim 3, wherein the display panel includes a liquid crystal display panel.

5. The apparatus according to claim 3, wherein the response characteristic detector includes a photo detector for detecting a brightness of the image displayed on the display panel, and a voltage generator for generating a voltage signal corresponding to the detected brightness.

6. The apparatus according to claim 5, wherein the level controller detects a difference of the voltage signal between two successive time periods and compares the difference of the voltage signal with a desired critical value to determine if a desired level of the response characteristic is obtained to control the variable voltage level.

7. The apparatus according to claim 3, wherein the sample pulse is a multi-step pulse having at least three voltage levels including the target level and the variable voltage level.

8. A system for measuring and adjusting liquid crystal response speed, comprising:

a generator system for generating a sample pulse having a first voltage level and a variable second voltage level;

a display system for receiving the sample pulse to display an image;

a response detector system for detecting a varying response characteristic of the display system by the sample pulse; and

a controller system for adjusting and setting the variable second voltage level.

9. The system for measuring and adjusting liquid crystal response speed according to claim 8, wherein the controller system adjusts the variable second voltage level until a desired level of the response characteristic is obtained.

10. The system for measuring and adjusting liquid crystal response speed according to claim 8, wherein the controller system sets the variable second voltage level according to modulating data when the desired level of the response characteristic is obtained.

11. The system for measuring and adjusting liquid crystal response speed according to claim 8, wherein the display system includes a liquid crystal display panel.

12. The system for measuring and adjusting liquid crystal response speed according to claim 8, wherein the response detector system includes a photo detector for detecting a brightness of the image displayed on the display system.

13. The system for measuring and adjusting liquid crystal response speed according to claim 12, wherein the response detector system includes a voltage generator for generating a voltage signal corresponding to the detected brightness.

14. The system for measuring and adjusting liquid crystal response speed according to claim 8, wherein the controller system detects a difference of the voltage signal between two successive time periods.

15. The system for measuring and adjusting liquid crystal response speed according to claim 14, wherein the controller system compares the difference of the voltage signal with a desired critical value to determine if a desired level of the varying response characteristic is obtained to control of the variable second voltage level.

16. The system for measuring and adjusting liquid crystal response speed according to claim 8, wherein the sample pulse is a multi-step pulse having at least three voltage levels including the first voltage level and the variable second voltage level.