Circuit and method for driving self light-emitting display device

• US 6,967,648 B2
• Filed: 07/30/2002
• Issued: 11/22/2005
• 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
• Primary Examiner(s): Osorio, Ricardo
• Application Number:
  US10/207,205
• Publication Number:
  US 20030025709A1
• Time in Patent Office: 1,211 Days
• Field of Search: 345/207, 348/602, 348/603
• US Class Current: 345/207
• 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 luminous intensity ambient light; and

a second step of controlling the number of color bits of respective color components in accordance with the sensed luminous intensity, wherein the number of color bits of respective color components are controlled based on a light-emitting efficiency of the respective color components.

2. 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 color bits in accordance with the sensed luminous intensity.

3. The circuit as claimed in claim 1, wherein if the luminous intensity sensed by the detective sensor reaches a predetermined luminance level, the second step reduces the number of color bits of respective color components by a predetermined ratio, wherein the number of color bits of a third color component is reduced by larger ratio than a first color component and a second color component.

4. The circuit as claimed in claim 3, wherein the first color component is a green color component, the second color component is a blue color component, and the third color component is a red color component.

5. The method as claimed in claim 1, further comprising increasing the luminance of respective color components by a predetermined ratio if the luminous intensity sensed by the detective sensor reaches a predetermined luminance level, wherein a luminance of a third color component is increased by a lower ratio than a first color component and a second color component.

6. The method as claimed in claim 5, wherein the first color component is a green color component and a second color component among the color components.

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

a detective sensor for sensing a luminous intensity of ambient light; and

a controller for controlling the number of

color bits of respective color components in accordance with the sensed luminous intensity, wherein the number of color bits of respective color components are controlled based on the light-emitting efficiency of the respective color components.

8. The circuit as claimed in claim 7, wherein if the luminous intensity sensed by the detective sensor reaches a predetermined luminance level, the controller performs a control operation so that the number of color bits of respective color components is reduced in a predetermined ratio, wherein the number of color bits of a third color component is reduced by a larger ratio than a first color component and a second color component.

9. The circuit as claimed in claim 8, wherein if the first color component is a green color component, the second color component is a blue color component, and the third color component is a red color component.

10. The circuit as claimed in claim 7, wherein if the luminous intensity sensed by the detective sensor reaches a predetermined luminance level, the controller performs a control operation so that luminance of respective color components is increased by a predetermined ratio, wherein a luminance of a third color component is increased by a lower ratio than a first color component and a second color component.

11. The circuit as claimed in claim 10, wherein the first color component is a green color component, the second color component is a blue color component, and the third color component is a red color component.