OPTICAL COMMUNICATION FOR SOLID-STATE LIGHT SOURCES

• US 20140270793A1
• Filed: 03/15/2013
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Bradford, Everett
• Granted Patent: US 9,705,594 B2
• Time in Patent Office: Days
• US Class Current: 398/118
• CPC Class Codes: H04B 10/116 Visible light communication
• CPC Class Codes: H05B 45/28 using temperature feedback
• CPC Class Codes: H05B 45/395 Linear regulators
• CPC Class Codes: H05B 45/44 with an active control inside an LED matrix
• CPC Class Codes: H05B 45/54 in a series array of LEDs

Abstract

The disclosure relates to a lighting fixture, which includes an array of solid-state light sources that are configured to generate light for general illumination lighting purposes and control circuitry. A drive signal is used to drive solid-state light sources. The control circuitry is configured to use a control output to control the drive signal to at least one of the solid-state light sources. The control output is configured to control the drive signal to 1) set at least one characteristic of the light generated by the array of the solid-state light sources, and 2) modulate the light with data for transmission. The light is modulated such that any change in the at least one characteristic based on the light being modulated is anthropically imperceptible. The characteristic of the light generated by the array of solid-state light sources may include the intensity, color, color temperature and the like.

Claims

21-1. The lighting fixture of claim 1 wherein the control output comprises a control output signal is pulsed and maintains a constant duty cycle over different frequencies of operation when transmitting the data and when not transmitting the data.

24. A lighting fixture, comprising:

an array of solid-state light sources configured to generate light; and

control circuitry adapted to;

control a luminous flux of a light output emitted from a set of one or more of the solid-state light sources in the array such that the luminous flux of the light output varies to define luminous flux pulses;

modulate a pulse width of the luminous flux pulses to set a characteristic of the light generated by the array of solid-state light sources; and

modulate a pulse frequency of the luminous flux pulses such that the light generated by the array of solid-state light sources transmits data.

25. The lighting fixture of claim 24 wherein the pulse frequency is modulated such that modulation of the pulse frequency is anthropically imperceptible.

26. A driver module for a lighting fixture comprising:

memory configured to store driver program code; and

control circuitry configured to execute the driver program code, wherein the driver program code causes the control circuitry to;

control a drive current to one or more solid-state light sources; and

modulate the drive current through at least one of the one or more solid-state light sources in accordance with data bits, such that a light output from the at least one of the one or more solid-state light sources carries a data bit representation of the data bits.

27. The driver module of claim 26 wherein the driver program code causes the control circuitry to modulate the drive current through the at least one of the one or more solid-state light sources such that the data bit representation of the data bits is anthropically imperceptible.

28. The driver module of claim 26 wherein the driver program code causes the control circuitry to modulate the drive current through the at least one of the one or more solid-state light sources by frequency shift keying.

29. The driver module of claim 28 wherein the driver program code causes the control circuitry to modulate the drive current through the at least one of the one or more solid-state light sources such that the data bit representation of the data bits is anthropically imperceptible by maintaining a pulse frequency of the frequency shift keying above a maximum pulse frequency for anthropic perception.

30. The driver module of claim 26 wherein the driver program code causes the control circuitry to control the drive current through the at least one of the one or more solid-state light sources to set a color temperature of light emitted from the one or more solid-state light sources.

31. The driver module of claim 30 wherein the driver program code causes the control circuitry to set the color temperature by setting a ratio of the light output from the at least one of the one or more solid-state light sources to other light outputs from other of the one or more solid-state light sources, wherein the driver program code causes the control circuitry to control the drive current to the one or more solid-state light sources that are a plurality of solid-state light sources.

32. The driver module of claim 26 wherein the driver program code causes the control circuitry to control the drive current through the at least one of the one or more solid-state light sources using pulse-width modulation, such that an intensity of the light output from the at least one of the one or more solid-state light sources is a function of a pulse frequency of the drive current through the at least one of the one or more solid-state light sources.

33. The driver module of claim 32 wherein the driver program code causes the control circuitry to modulate the drive current through the at least one of the one or more solid-state light sources by adjusting the pulse frequency from a first pulse frequency value to a second pulse frequency value.

34. The driver module of claim 33 wherein the driver program code causes the control circuitry to:

represent a first bit state of the data bits by adjusting the pulse frequency from the first pulse frequency value to the second pulse frequency value for greater than a temporal length; and

represent a second bit state that is antipodal to the first bit state by adjusting the pulse frequency from the first pulse frequency value to the second pulse frequency value for less than the temporal length.

35. The driver module of claim 26 wherein the control circuitry comprises:

a first switch operable to be switched to an open state from a closed state and from the closed state to the open state in accordance with a control output signal level of a control output signal, wherein the switch is coupled such that the drive current bypasses the at least one of the one or more solid state light sources when the switch is in the open state and such that the drive current flows through the switch when the switch is in the closed state; and

a system controller configured to execute the driver program code for the control circuitry, wherein the system controller is configured to generate the control output signal.

36. The driver module of claim 35 further comprising:

a second switch operable to be switched to the open state from the closed state, and from the closed state to the open state, in accordance with a second control output signal level of a second control output signal, wherein the second switch is coupled such that the drive current is prevented from going through all of the one or more solid-state light sources when the second switch is in the closed state; and

wherein the system controller is further configured to generate the second control output signal.

37. The driver module of claim 36 wherein the driver program code causes the system controller to control the drive current to the one or more solid-state light sources comprising a plurality of light-emitting diodes (LEDs) and the at least one of the one or more solid-state light sources is one of the plurality of LEDs, wherein the one of the plurality of LEDs is coupled in shunt with another one of the plurality of LEDs.

38. A lighting fixture comprising:

one or more solid-state light sources; and

a driver module configured to;

control a drive current to the one or more solid-state light sources; and

modulate the drive current through at least one of the one or more solid-state light sources in accordance with data bits, such that a light output from the at least one of the one or more solid-state light sources carries a data bit representation of the data bits.

39. The lighting fixture of claim 38 wherein the driver module is configured to modulate the drive current through the at least one of the one or more solid-state light sources such that the data bit representation of the data bits is anthropically imperceptible.

40. The lighting fixture of claim 38 wherein the driver module is configured to modulate the drive current through the at least one of the one or more solid-state light sources by frequency shift keying.

41. The lighting fixture of claim 40 wherein the driver module is configured to modulate the drive current through the at least one of the one or more solid-state light sources such that the data bit representation of the data bits is anthropically imperceptible by maintaining a pulse frequency of the frequency shift keying above a maximum pulse frequency for anthropic perception.

42. The lighting fixture of claim 38 wherein the driver module is configured to control the drive current through the at least one of the one or more solid-state light sources to set a color temperature of light emitted from the one or more solid-state light sources.

43. The lighting fixture of claim 38 wherein the driver module is configured to control the drive current through the at least one of the one or more solid-state light sources using pulse-width modulation, such that an intensity of the light output from the at least one of the one or more solid-state light sources is a function of a pulse frequency of the drive current through the at least one of the one or more solid-state light sources.

44. The lighting fixture of claim 43 wherein the driver module is configured to modulate the drive current through the at least one of the one or more solid-state light sources by adjusting the pulse frequency from a first pulse frequency value to a second pulse frequency value.

45. The lighting fixture of claim 44 wherein the driver module is configured to:

represent a first bit state of the data bits by adjusting the pulse frequency from the first pulse frequency value to the second pulse frequency value for greater than a temporal length; and

represent a second bit state that is antipodal to the first bit state by adjusting the pulse frequency from the first pulse frequency value to the second pulse frequency value for less than the temporal length.