Electronic device having a light bus for controlling light emitting elements

• US 20060214876A1
• Filed: 03/23/2005
• Published: 09/28/2006
• Est. Priority Date: 03/23/2005
• Status: Abandoned Application

• Current Assignee: Sony Ericsson Mobile Communications AB (Sony Group Corp.)
• Original Assignee: Sony Ericsson Mobile Communications AB (Sony Group Corp.)
• Inventors: Jendbro, Magnus, Ekdahl, Thomas
• Application Number:
  US11/087,270
• Publication Number:
  US 20060214876A1
• Time in Patent Office: Days
• US Class Current: 345/46
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/30 Driver circuits
• CPC Class Codes: H05B 45/325 Pulse-width modulation [PWM]
• CPC Class Codes: H05B 45/345 Current stabilisation; Maintaining constant current
• CPC Class Codes: H05B 45/38 using boost topology
• CPC Class Codes: H05B 45/46 having LEDs disposed in parallel lines

Abstract

An apparatus for driving a plurality of light emitting diodes (LEDs) includes a general purpose input/output (GPIO) for outputting a control signal. The apparatus further includes a plurality of LED packages via a shared control bus to the GPIO. This Abstract is provided to comply with rules requiring an Abstract that allows a searcher or other reader to quickly ascertain subject matter of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Claims

1. An apparatus for driving a plurality of light emitting diodes (LEDs), the apparatus comprising:

a general purpose input/output (GPIO) for outputting a control signal; and

a plurality of LED packages connected via a shared control bus to the GPIO.

2. The apparatus of claim 1, wherein at least one of the plurality of LED packages comprises programming logic circuitry.

3. The apparatus of claim 2, wherein the programming logic circuitry comprises:

address decode circuitry;

data decode circuitry;

a data latch; and

a plurality of Pulse Width Modulation/Digital-to-Analog converters.

4. The apparatus of claim 3, wherein the address decode circuitry is adapted to receive the control signal via the shared bus.

5. The apparatus of claim 4, wherein the data latch is adapted to generate and store power control data based upon the control signal.

6. The apparatus of claim 5, wherein:

the control data comprises an n-bit address pattern followed by an m-bit data pattern; and

n and m are positive integers.

7. The apparatus of claim 6, wherein the n-bit address pattern comprises an address for a particular LED package of the plurality of LED packages.

8. The apparatus of claim 7, wherein the m-bit data pattern includes information to control at least one of an intensity and a brightness of the particular LED package.

9. The apparatus of claim 1, wherein the plurality of LED packages are connected in parallel on the shared control bus.

10. The apparatus of claim 1, wherein the control signal is used to selectively control at least one of the LED packages.

11. The apparatus of claim 1, wherein the control signal comprises address information corresponding to a particular LED package of the plurality of LED packages.

12. The apparatus of claim 1, wherein the control signal comprises data used to control at least one of LED-package brightness.

13. A method of driving at least one of a plurality of light emitting diodes (LEDs), the method comprising:

outputting a control signal from a general purpose input/output (GPIO) to a plurality of LED packages connected to the GPIO via a shared control bus; and

selectively operating at least one of the plurality of LED packages responsive to information contained in the control signal.

14. The method of claim 13, wherein at least one of the plurality of LED packages comprises programming logic circuitry.

15. The method of claim 14, wherein the logic circuitry comprises:

address decode circuitry;

data decode circuitry;

a data latch; and

a plurality of Pulse Width Modulation/Digital-to-Analog converters.

16. The method of claim 15, wherein the address decode circuitry is adapted to receive the control signal via the shared control bus.

17. The method of claim 16, wherein the data latch is adapted to generate and store power control data responsive to the control signal.

18. The method of claim 17:

wherein the control data comprises a n-bit address pattern followed by a m-bit data pattern; and

n and m are positive integers.

19. The method of claim 18, wherein the n-bit address pattern comprises an address of a particular LED package of the plurality of LED packages.

20. The method of claim 19, wherein the m-bit data pattern includes information to control at least one of an intensity and a brightness of the particular LED package.

21. The method of claim 13, wherein the plurality of LED packages are connected in parallel to the shared control bus.

22. The method of claim 13, wherein the control signal is used to selectively control at least one of the LED packages.

23. The method of claim 13, wherein the control signal comprises address information corresponding to a particular LED package of the plurality of LED packages.

24. The method of claim 13, wherein the control signal comprises data used to control at least one of LED package brightness.

25. An article of manufacture for driving at least one of a plurality of light emitting diodes (LEDs), the article of manufacture comprising:

at least one computer readable medium;

processor instructions contained on the at least one computer readable medium, the processor instructions configured to be readable from the at least one computer readable medium by at least one processor and thereby cause the at least one processor to operate as to;

output a control signal from a general purpose input/output (GPIO) to a plurality of LED packages connected to the GPIO via a shared control bus; and

selectively operate at least one of the plurality of LED packages responsive to information contained in the control signal.

26. A method of assigning an address to at least one light emitting diode (LED), the method comprising:

mounting at least one LED package on a circuit board;

exposing at least one of the at least one LED package to light;

responsive to the step of exposing, the at least one exposed LED package entering an address programming mode;

receiving, by the at least one exposed LED package, of a control signal;

wherein the control signal comprises address information corresponding to the at least one exposed LED package.