Methods and apparatus for controlling devices in a networked lighting system

• US 7,598,684 B2
• Filed: 06/12/2007
• Issued: 10/06/2009
• Est. Priority Date: 05/30/2001
• Status: Expired due to Term

• Current Assignee: Signify North America Corporation (Signify N.V.)
• Original Assignee: Philips Solid-State Lighting Solutions (Koninklijke Philips N.V.)
• Inventors: Lys, Ihor A., Morgan, Frederick M.
• Primary Examiner(s): Owens; Douglas W
• Assistant Examiner(s): A; Minh D
• Application Number:
  US11/761,491
• Publication Number:
  US 20070237284A1
• Time in Patent Office: 847 Days
• Field of Search: 315/291, 315/307, 315/224, 315/244
• US Class Current: 315/307
• CPC Class Codes: H05B 47/18 via data-bus transmission

Abstract

Methods and apparatus for computer-based control of light sources in a networked lighting system. In one example, a plurality of LED-based lighting systems are arranged as computer controllable “light strings.” Applications contemplated for such light strings include, but are not limited to, decorative and entertainment-oriented lighting applications (e.g., Christmas tree lights, display lights, theme park lighting, video and other game arcade lighting, etc.). Via computer control, one or more such light strings may provide a variety of complex temporal and color-changing lighting effects. In one example, lighting data is communicated in a given light string in a serial manner, according to a variety of different data transmission and processing schemes. In another example, individual lighting systems of a light string are coupled together via a variety of different conduit configurations to provide for easy coupling and arrangement of multiple light sources constituting the light string. In yet another example, small LED-based lighting systems capable of being arranged in a light string configuration are manufactured as integrated circuits including data processing circuitry and control circuitry for LED light sources, and are packaged along with LEDs for convenient coupling to a conduit to connect multiple lighting systems.

Claims

1. An apparatus adapted to process serial data and to control at least one LED in response to the serial data, comprising:

a counter circuit adapted to measure a first period between a first edge of a first polarity of the serial data and a second edge of the first polarity of the serial data, the counter circuit being further adapted to measure a second period between the first edge of the first polarity of the serial data and a first edge of a second polarity of the serial data, the counter circuit being further adapted to compare the second period with a predetermined fraction of the first period to determine if the serial data is in a first state.

2. The apparatus of claim 1 wherein the first polarity comprises a rising edge of the serial data and the second polarity comprises a falling edge of the serial data.

3. The apparatus of claim 1 wherein the first polarity comprises a falling edge of the serial data and the second polarity comprises a rising edge of the serial data.

4. The apparatus of claim 1 wherein the predetermined fraction is approximately one half.

5. The apparatus of claim 4 wherein the counter circuit is adapted to determine that the serial data is in the first data state when the second period is less than approximately one half of the first period.

6. The apparatus of claim 5 wherein the first state comprises a high data signal.

7. The apparatus of claim 5 wherein the first state comprises a low data signal.

8. The apparatus of claim 1 wherein the counter circuit is adapted to detect the location of a second edge of the second polarity by sampling a state of the serial data at a predetermined sampling period determined from the first period.

9. The apparatus of claim 8 wherein the predetermined sampling period is approximately half of the first period.

10. The apparatus of claim 8 wherein the predetermined sampling period is less than half of the first period.

11. The apparatus of claim 1, further comprising:

a transmitting circuit adapted to asynchronously pass the first edge of the first polarity of the serial data from an input port to an output port and transmit the first edge of the second polarity to an output port at a time based on a desired data state to be transmitted.

12. The apparatus of claim 11 wherein the time is calculated from the second period.

13. The apparatus of claim 11 wherein the time is approximately the same as the second period.

14. The apparatus of claim 11 wherein the time is determined from one of at least two trigger values based on the desired data state to be transmitted.

15. The apparatus of claim 14 wherein the at least two trigger values comprise a first value equal to less than half the first period and a second value equal to more than half the first period.

16. The apparatus of claim 14 wherein the at least two trigger values comprise approximately one forth of the first period and approximately three fourths of the first period.

17. The apparatus of claim 14 wherein the at least one of the at least two trigger values comprises a fixed value.

18. The apparatus of claim 14 wherein the at least one of the at least two trigger values comprises a value calculated by subtracting a fixed value from the first period.

19. The apparatus of claim 14 wherein the at least one of the at least two trigger values comprises a value calculated by subtracting a variable value from the first period, wherein the variable value is calculated from the first period.

20. An integrated circuit, comprising:

a power input pin adapted to receive external power;

a ground pin adapted to connect the integrated circuit to a common reference potential;

a reference pin adapted to connect to an external component to provide the integrated circuit a reference from which to regulate at least one LED;

a serial data input pin for receiving serial data;

a serial data output pin for transmitting serial data; and

at least one switchable constant current output pin adapted to control the at least one LED.

21. The integrated circuit of claim 20 wherein the at least one LED comprises at least three LEDs and the at least one switchable constant current output pin comprises three switchable constant current output pins adapted to independently control separate LEDs of the at least three LEDs.

22. The integrated circuit of claim 21 wherein the total number of functional pins equals eight.

23. The integrated circuit of claim 20, further comprising:

an internal clock generation circuit wherein the internal clock generation circuit generates a clock pulse and the integrated circuit is further adapted to read serial data in coordination with the clock pulse.

24. The integrated circuit of claim 20 wherein the integrated circuit does not require a precision external clock signal to properly read serial data.