Lamp driver system with improved redundancy

• US 20050093461A1
• Filed: 10/31/2003
• Published: 05/05/2005
• Est. Priority Date: 10/31/2003
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Haim, Elias S., Harris, Allan E., Cull, Brian D., Schmidt, John F.
• Granted Patent: US 7,002,306 B2
• Time in Patent Office: Days
• US Class Current: 315/149
• CPC Class Codes: H05B 41/46 Circuits providing for substitution in case of failure of the lamp

Abstract

A lamp driver system that facilitates improved reliability and performance for a display system is provided. The lamp driver system includes a fault detector and an output steering device. The fault detector determines when a failure occurs in a lamp illuminating the display system. The output steering device selectively drives the lamps to illuminate the display system. Specifically, when a failure in a first lamp is detected by the fault detector, the output steering device is used to selectively drive a second lamp to provide the needed illumination to the display system. The lamp driver system thus can provide redundancy in the display system by automatically switching to a backup lamp when a failure in the first lamp is detected. This redundancy can improve the reliability and performance of the display system.

Claims

1. A lamp driver system for selectively driving a first lamp and a second lamp, the lamp driver system comprising:

a fault detector, the fault detector coupled to the first lamp and the second lamp to determine when a failure occurs in the first lamp or the second lamp; and

an output steering device, the output steering device selectively driving the first lamp and the second lamp in response to failures detected in the first lamp or the second lamp.

2. The lamp driver system of claim 1 wherein the first lamp and the second lamp comprise fluorescent lamps.

3. The lamp driver system of claim 1 wherein the first lamp and the second lamp comprise fluorescent lamps in a liquid crystal display system.

4. The lamp driver system of claim 1 wherein the fault detector is coupled to the first lamp and the second lamp through a first photo detector at the first lamp and a second photo detector at the second lamp.

5. The lamp driver system of claim 1 wherein the fault detector comprises a microcontroller configured to determine when a failure has occurred in the first or second lamp.

6. The lamp driver system of claim 1 wherein the output steering device drives the first lamp until a failure in the first lamp is detected by the fault detector, and wherein the output steering device drives the second lamp when a failure is detected in the first lamp.

7. The lamp driver system of claim 1 wherein the output steering device comprises a programmable device that selectively directs an output of a power amplifier.

8. The lamp driver system of claim 7 wherein the programmable device comprises a microcontroller, a complex programmable logic device (CPLD), field programmable gate array (FPGA), or application specific integrated circuit (ASIC).

9. A lamp driver system for selectively driving a first lamp and a second lamp, the lamp driver system comprising:

a first controller, the first controller selectively driving the first lamp and the second lamp; and

a fault detector, the fault detector coupled to the first lamp and the second lamp to determine when a failure occurs in the first lamp or the second lamp, and wherein the fault detected is coupled to the first controller to determine when a failure occurs in the first controller; and

a second controller, second controller selectively driving the first lamp and the second lamp when a failure occurs in the first controller.

10. The lamp driver system of claim 9 wherein the first lamp and the second lamp comprises fluorescent lamps in a liquid crystal display.

11. The lamp driver system of claim 9 wherein the first controller further comprises a first output steering device, the first output steering device selectively controlling an output of the first controller to selectively drive the first lamp and the second lamp.

12. The lamp driver system of claim 11 wherein the second controller further comprises a second output steering device, the second output steering device selectively controlling an output of the second controller to selectively drive the first lamp and the second lamp.

13. The lamp driver system of claim 11 wherein the fault detector comprises a programmable device configured to determine when a failure has occurred in the first or second lamp and when a failure has occurred in the first controller.

14. The lamp driver system of claim 13 wherein the programmable device further selectively enables a power amplifier in the lamp driver system.

15. The lamp driver system of claim 13 wherein the programmable device comprises a microcontroller, a complex programmable logic device (CPLD), field programmable gate array (FPGA), or application specific integrated circuit (ASIC).

16. A lamp driver system for selectively driving a first lamp and a second lamp, the lamp driver system comprising:

a first controller, the first controller including;

a first fault detector, the first fault detector coupled to the first lamp and the second lamp to determine when a failure occurs in the first lamp or the second lamp;

a first output steering device, the first output steering device selectively driving the first lamp and the second lamp; and

a second controller, the second controller including;

a second fault detector, the second fault detector coupled to the first lamp and the second lamp to determine when a failure occurs in the first lamp or the second lamp and coupled to the first controller to determine when a failure occurs in the first controller; and

a second output steering device, the second output steering device selectively driving the first lamp and the second lamp.

17. The lamp driver system of claim 16 wherein the first fault detector and the first output steering device comprises a first programmable device configured to determine when a failure has occurred in the first or second lamp and when a failure has occurred in the second controller.

18. The lamp driver system of claim 17 wherein the second fault detector and the second output steering device comprises a second programmable device configured to determine when a failure has occurred in the first or second lamp and when a failure has occurred in the first controller.

19. The lamp driver system of claim 18 wherein the first programmable device and the second programmable device comprise a microcontroller, a complex programmable logic device (CPLD), field programmable gate array (FPGA), or application specific integrated circuit (ASIC).

20. The lamp driver system of claim 16 wherein the first lamp and the second lamp comprises fluorescent lamps in a liquid crystal display.