Circuit and method for driving self light-emitting display device

• US 20030025709A1
• Filed: 07/30/2002
• Published: 02/06/2003
• Est. Priority Date: 07/31/2001
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Tak, Yoon Heung, Kim, Hak Su, Lee, Minho
• Granted Patent: US 6,967,648 B2
• Time in Patent Office: Days
• US Class Current: 345/589
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2340/0428 Gradation resolution change
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/22 using optical feedback

Abstract

Disclosed is a circuit for driving a self light-emitting display device which itself emits light when an electric or other energy is inputted thereto and a method thereof. According to the circuit and method, the self light-emitting display device can be driven more stably and with a higher efficiency by adjusting the number of used bits and luminance of respective color components in accordance with a luminance change of an external light and keeping a constant contrast ratio irrespective of the adjustment of the bit numbers.

Claims

1. A method of driving a self light-emitting display device comprising:

a first step of sensing a grade of an external light; and

a second step of controlling depths of respective color components in accordance with the sensed grade of the light.

2. The method as claimed in claim 1, wherein the first step measures an external luminance.

3. The method as claimed in claim 1, wherein the second step controls the light-emitting display device so that the respective color components are turned on with different depths in accordance with the sensed grade of the light.

5. The method as claimed in claim 1, wherein the first step measures an external luminance.

6. The method as claimed in claim 1, wherein the second step controls the light-emitting display device so that the respective color components are turned on with different depths in accordance with the sensed grade of the light.

4. A method of driving a self light-emitting display device comprising:

a first step of sensing a grade of an external light; and

a second step of controlling luminance of respective color components in accordance with the sensed grade of the light.

7. A method of driving a self light-emitting display device comprising:

a first step of sensing a grade of an external light; and

a second step of controlling the light-emitting display device so that the respective color components are turned on with different depths in accordance with the sensed external light and at the same time luminance of the respective color components is controlled.

8. The method as claimed in claim 7, wherein the first step measures an external luminance.

9. The method as claimed in claim 7, wherein the second step controls the light-emitting display device so that the respective color components are turned on with different depths or different luminance in accordance with the sensed grade of the light.

10. A circuit for driving a self light-emitting display device comprising:

the self light-emitting display device;

a detective sensor for sensing a grade of an external light; and

a controller for controlling the number of used bits and/or luminance of respective color components of the self light-emitting display device with reference to sensed information provided from the detective sensor.

11. The circuit as claimed in claim 10, wherein if a luminance of light sensed by the detective sensor corresponds to an outdoor luminance level, the controller performs a control operation so that the number of bits of the color component having a good light-emitting efficiency among the color components of the light-emitting display device is reduced in a predetermined ratio, and the number of bits of the color component having a relatively bad light-emitting efficiency is reduced in a larger ratio than the color component having the good light-emitting efficiency.

12. The circuit as claimed in claim 11, wherein if a luminance of light sensed by the detective sensor corresponds to an outdoor luminance level, the controller performs a control operation so that the number of bits of a green color component and/or a blue color component among the color components of the light-emitting display device is reduced in a predetermined ratio, and so that the number of bits of a red color component is reduced in a larger ratio than the green and/or blue color components.

13. The circuit as claimed in claim 10, wherein if a luminance of light sensed by the detective sensor corresponds to an outdoor luminance level, the controller performs a control operation so that luminance of the color component having a good light-emitting efficiency among the color components of the light-emitting display device increases in a relatively high ratio, and luminance of the color component having a relatively bad light-emitting efficiency increases in a relatively low ratio.

14. The circuit as claimed in claim 11, wherein if a luminance of light sensed by the detective sensor corresponds to an outdoor luminance level, the controller performs a control operation so that luminance of a green color component and/or a blue color component among the color components of the light-emitting display device increases in a relatively high ratio, and so that luminance of a red color component increases in a relatively low ratio.