Addressable LED architecture

• US 20080088258A1
• Filed: 07/26/2007
• Published: 04/17/2008
• Est. Priority Date: 07/28/2006
• Status: Active Grant

• Current Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Asia Pacific Pte Limited (STMicroelectronics NV)
• Inventors: Ng, Chee
• Granted Patent: US 7,605,547 B2
• Time in Patent Office: Days
• US Class Current: 315/294
• CPC Class Codes: H05B 45/37 Converter circuits
• CPC Class Codes: H05B 47/18 via data-bus transmission

Abstract

The present disclosure provides an addressable light emitting diodes (LED) architecture that is able to control a plurality of LEDs individually. The present disclosure further provides a method of controlling the operation of at least one chain of serially connected LEDs.

Claims

1. A light emitting diode (LED) architecture comprising:

a plurality of chain controllers configured to generate predetermined drive currents, wherein the predetermined drive currents include switching signals;

a plurality of LED devices, wherein the plurality of LED devices are serially connected to form a plurality of chains of LED devices, wherein each chain of LED devices is coupled to one of the plurality of chain controllers, wherein each LED device comprises;

at least one LED; and

a LED controller coupled to the LED, wherein the LED controller is configured to receive the switching signals for controlling the operation of the LED,

wherein the plurality of chain controllers generate predetermined drive currents to control the operation of each LED controller in each chain of LED devices, thereby controlling the operation of each LED individually in the each chain of LED devices.

2. The LED architecture of claim 1, wherein the LED controller comprises:

a switch coupled to the LED; and

a switch controller coupled to the switch, wherein the switch controller opens or closes the switch in response to the switching signals, and wherein the switch when opened allows electrical current to flow through the LED, wherein the switch when closed shunts electrical current around the LED.

3. The LED architecture of claim 2, wherein each LED device further comprises a charge pump for maintaining the voltage supply to the switch controller.

4. The LED architecture of claim 2, wherein the switch is a NMOS transistor.

5. The LED architecture of claim 1, wherein the plurality of chain controllers can be dedicated integrated chips.

6. The LED architecture of claim 1, wherein the LED controller can be a dedicated integrated chip.

7. The LED architecture of claim 1, further comprising a master controller coupled to the plurality of chain controllers, wherein the master controller controls the operation of the plurality of chain controllers.

8. The LED architecture of claim 7, wherein the master controller can be coupled to the plurality of chain controllers via 12C, SN or CAN connections.

9. The LED architecture of claim 7, wherein the master controller can be a microcontroller unit.

10. The LED architecture of claim 1, wherein each chain of LED devices may comprise different colors or types of LEDs.

11. The LED architecture of claim 1, wherein the electronic device is selected from the group consisting of large display screens, or display means in personal digital assistants, cell phones, digital still cameras, and camcorders.

12. A method of controlling the operation of at least one chain of serially connected light emitting diodes (LEDs), the method comprising:

generating predetermined drive currents by a chain controller, wherein the chain controller is coupled to the at least one chain of serially connected LEDs, wherein the predetermined drive currents include switching signals;

receiving switching signals by a plurality of LED controllers, wherein each of the plurality of LED controllers is coupled to one of the serially connected LEDs, and

wherein the plurality of LED controllers control the operation of the serially connected LEDs in response to the switching signals, thereby controlling the operation of the serially connected LEDs individually.

13. The method of claim 12, further comprising:

transmitting digital signals by a master controller, wherein the master controller is coupled to the chain controller, wherein the master controller controls the predetermined drive currents generated by the chain controller.

14. The method of claim 13, wherein the master controller can be coupled to each chain controller via 12C, SPI or CAN connections.

15. The method of claim 12, wherein each of the plurality of LED controllers comprises:

a switch coupled to the LED; and

a switch controller coupled to the switch, wherein the switch controller opens or closes the switch in response to the switching signals, wherein the switch when opened allows electrical current to flow through the LED, wherein the switch when closed shunts electrical current around the LED.

16. The method of claim 12, wherein the at least one chain of serially connected LEDs may comprise different colors or types of LEDs.

17. An addressable light emitting diode (LED) architecture comprising:

a plurality of chain controllers configured to generate predetermined drive currents, wherein the predetermined drive currents include switching signals;

a plurality of LED devices, wherein the plurality of LED devices are serially connected to form a plurality of chains of LED devices, wherein each chain of LED devices is coupled to one of the plurality of chain controllers, wherein each LED device comprises;

at least one LED; and

a LED controller coupled to the LED, wherein the LED controller is configured to receive the switching signals for controlling the operation of the LED,

wherein the plurality of chain controllers generate predetermined drive currents to control the operation of each LED controller in each chain of LED devices, thereby controlling the operation of each LED individually in the each chain of LED devices; and

a master controller coupled to the plurality of chain controllers to control the operation of the plurality of chain controllers.

18. The addressable LED architecture of claim 17, wherein the LED controller comprises:

a switch coupled to the LED; and

a switch controller coupled to the switch, wherein the switch controller opens or closes the switch in response to the switching signals, and wherein the switch when opened allows electrical current to flow through the LED, wherein the switch when closed shunts electrical current around the LED.

19. The addressable LED architecture of claim 18, wherein each LED device further comprises a charge pump for maintaining the voltage supply to the switch controller.

20. The addressable LED architecture of claim 18, wherein the switch is a NMOS transistor.