Display apparatus and control method thereof

• US 7,755,297 B2
• Filed: 05/03/2007
• Issued: 07/13/2010
• Est. Priority Date: 06/28/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kang, Jeong-Il, Lee, Sang-hoon
• Primary Examiner(s): Owens; Douglas W
• Assistant Examiner(s): Chen; Jianzi
• Application Number:
  US11/797,434
• Publication Number:
  US 20080042590A1
• Time in Patent Office: 1,167 Days
• Field of Search: 315/291, 315/294, 315/297, 315/209.R, 315 86- 93, 315/185.R, 315/186, 315/192, 315/193, 315/312, 315/313, 315/362
• US Class Current: 315/224
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]

Abstract

A display apparatus and a control method thereof are provided. The inventive method and apparatus improves a response speed of a light source and image quality by minimizing a ripple of a current and reducing a time required to increase/decrease an amount of a current to drive a light source when a light source is turned on and off or a size of a current used to drive a light source is changed. An exemplary display apparatus includes a light source, a current generator which generates a driving current to drive the light source, a first current consumer which has a smaller resistance value than the light source, a first switch which is switched on and off to supply the driving current generated by the current generator either to the light source or to the first current consumer and a controller which controls the current generator to generate the driving current to reach a target value, and controls the first switch to supply the driving current to the first current consumer if the target value is smaller than the driving current.

Claims

1. A display apparatus, comprising:

a light source;

a current generator for generating a driving current to drive the light source;

a first current consumer which has a smaller resistance value than the light source;

a first switch which is switched on and off to supply the driving current generated by the current generator either to the light source or to the first current consumer; and

a controller for controlling the current generator to generate the driving current to reach a target value, and for controlling the first switch to supply the driving current to the first current consumer if the driving current is larger than the target value.

2. The display apparatus according to claim 1, wherein the first current consumer and the first switch are connected with each other in series, and the first current consumer and the first switch are connected with the light source in parallel.

3. The display apparatus according to claim 1, wherein the light source comprises a light emitting diode (LED).

4. The display apparatus according to claim 1, wherein the first switch comprises a transistor which is turned on and off by a control of the controller.

5. The display apparatus according to claim 1, wherein the controller controls the current generator to be disabled when the display apparatus is turned off.

6. The display apparatus according to claim 1, further comprising:

a second current consumer which has a smaller resistance value than the first current consumer; and

a second switch for supplying the driving current generated by the current generator to the second current consumer, wherein

the controller controls the second switch to supply the driving current to the second current consumer if the target value is larger than the driving current.

7. The display apparatus according to claim 6, wherein the first current consumer and the first switch are connected with each other in series, and the first current consumer and the first switch are connected with the light source in parallel.

8. The display apparatus according to claim 6, wherein the second current consumer and the second switch are connected with each other in series, and the second current consumer and the second switch are connected with the light source in parallel.

9. The display apparatus according to claim 6, wherein the second switch comprises a transistor which is turned on and off by a control of the controller.

10. A method of controlling a display apparatus which includes a light source and a first current consumer having a smaller resistance value than the light source, the method comprising:

generating a driving current to drive the light source;

determining whether the generated driving current reaches a target value;

supplying the driving current either to the light source or to the first current consumer depending on the determination; and

consuming the driving current by the first current consumer if the driving current is larger than the target value.

11. The method according to claim 10, wherein the consuming of the driving current comprises consuming the driving current by a resistance value smaller than the first current consumer if the target value is larger than the driving current.

12. An apparatus connected to an electrical load comprising:

a first current consumer having a smaller resistance value than the electrical load;

a first switch, which is switched on and off to supply current either to the electrical load or the first current consumer; and

a controller for controlling the first switch to supply the current to the first current consumer if the current is larger than a target value.

13. The display apparatus according to claim 12, wherein the first current consumer and the first switch are connected with each other in series, and the first current consumer and the first switch are connected with the electrical load in parallel.

14. The display apparatus according to claim 12, wherein the first switch comprises a transistor which is turned on and off by a control of the controller and further wherein the load comprises a light source and the light source comprises a light emitting diode (LED).

15. The display apparatus according to claim 12, further comprising:

a second current consumer which has a smaller resistance value than the first current consumer; and

a second switch for supplying the current to the second current consumer, wherein

the controller controls the second switch to supply the current to the second current consumer if the driving current is smaller than the target value.

16. The display apparatus according to claim 15, wherein the first current consumer and the first switch are connected with each other in series, and the first current consumer and the first switch are connected with the light source in parallel.

17. The display apparatus according to claim 16, wherein the second current consumer and the second switch are connected with each other in series, and the second current consumer and the second switch are connected with the light source in parallel.