Multicolored LED lighting method and apparatus

• US 6,150,774 A
• Filed: 10/22/1999
• Issued: 11/21/2000
• Est. Priority Date: 08/26/1997
• Status: Expired due to Term

• Current Assignee: Philips Lighting North America Corporation (Koninklijke Philips N.V.)
• Original Assignee: Color Kinetics Incorporated (Signify N.V.)
• Inventors: Lys, Ihor, Mueller, George G.
• Primary Examiner(s): Philogene, Haissa
• Application Number:
  US09/425,770
• Time in Patent Office: 396 Days
• Field of Search: 315/291, 315/292, 315/295, 315/300, 315/308, 315/312, 315/302, 315/314, 315/76, 315/360, 315/362
• US Class Current: 315/291
• CPC Class Codes: A61N 2005/0652 Arrays of diodes
• CPC Class Codes: A61N 5/0616 Skin treatment other than tanning
• CPC Class Codes: A61N 5/0618 Psychological treatment
• CPC Class Codes: F21K 9/20 Light sources comprising attachment means
• CPC Class Codes: F21S 4/28 rigid, e.g. LED bars
• CPC Class Codes: F21V 33/004 Sanitary equipment, e.g. mirrors, showers, toilet seats or paper dispensers
• CPC Class Codes: F21V 33/006 General building constructions or finishing work for buildings, e.g. roofs, gutters, stairs or floors; Garden equipment; Sunshades or parasols
• CPC Class Codes: F21W 2111/027 for indicating kerbs, steps or stairs
• CPC Class Codes: F21W 2111/08 for handles or handrails
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G09G 2300/06 Passive matrix structure, i.e. with direct application of both column and row voltages to the light emitting or modulating elements, other than LCD or OLED
• CPC Class Codes: G09G 2310/0272 Details of drivers for data electrodes, the drivers communicating data to the pixels by means of a current
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 3/14 Semiconductor devices, e.g. diodes
• CPC Class Codes: G09G 3/2014 by modulation of the duration of a single pulse during which the logic level remains constant
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: G09G 3/3283 in which the data driver supplies a variable data current for setting the current through, or the voltage across, the light-emitting elements
• CPC Class Codes: H05B 45/20 : Controlling the colour of the light
• CPC Class Codes: H05B 45/325 : Pulse-width modulation [PWM]
• CPC Class Codes: H05B 45/395 : Linear regulators
• CPC Class Codes: H05B 45/46 : having LEDs disposed in parallel lines
• CPC Class Codes: H05B 47/10 : Controlling the light source
• CPC Class Codes: H05B 47/155 : Coordinated control of two or more light sources
• CPC Class Codes: H05B 47/18 : via data-bus transmission
• CPC Class Codes: Y02B 20/30 : Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

The systems and methods described herein relate to LED systems capable of generating light, such as for illumination or display purposes. The light-emitting LEDs may be controlled by a processor to alter the brightness and/or color of the generated light, e.g., by using pulse-width modulated signals. Thus, the resulting illumination may be controlled by a computer program to provide complex, predesigned patterns of light in virtually any environment.

Claims

1. Light apparatus comprising:

a power terminal;

at least one LED coupled to the power terminal;

a current sink coupled to the at least one LED, the current sink comprising an input responsive to an activation signal that enables flow of current through the current sink;

an addressable controller having an alterable address, the controller coupled to the input and having timing means for generating the activation signal for a predefined portion of a timing cycle;

the addressable controller further comprising means for receiving data corresponding to the alterable address and indicative of the predefined portion of the timing cycle.

2. The light apparatus of claim 1 wherein the predefined portion represents the duty cycle of a PWM signal and the timing cycle is the PWM period.

3. A modular LED illumination assembly comprising

a power module having a terminal for attachment to a power supply;

and

a light module comprising a plurality of LEDs and having an electrical connector removably attachable to the power module,

the power module further comprising a current regulator for controlling maximum current supplied to the plurality of LED'"'"'s, and the light module further comprising means for programming the current regulator,

whereby the light module is capable of being conveniently interchanged with a different light module having a different light intensity rating.

4. An illumination apparatus comprising:

a plurality of LEDs of at least two different colors adapted to be coupled to a power source and to a common potential reference;

a current sink interposed between the plurality of LEDs and the common potential reference, the current sink comprising at least two switches corresponding to respective current paths of the at least two different color LEDs;

control means for periodically and independently opening and closing the at least two switches at high frequency and for generating a duty cycle thereby;

programming means coupled to the control means for programming respective duty cycles for each color of the at least two different color LEDs.

5. The apparatus of claim 4 wherein the duty cycle ranges from a minimum to a maximum, and the programming means is adapted to generate a substantially continuous range of duty cycles between the minimum and the maximum.

6. The apparatus of claim 4 wherein the programming means comprises respective potentiometers for each color of the at least two different color LEDs each having an independently adjustable setting, and the control means comprises an analog-to-digital converter for converting each independently adjustable setting into a numerical value indicative of each respective duty cycle.

7. The apparatus of claim 4 comprising a housing that substantially encloses the plurality of LEDs, the current sink, the control means and the programming means.

8. The apparatus of claim 7 wherein the housing is hand-held.

9. An Edison-mount lightbulb comprising:

voltage regulating means for converting an AC potential into a DC power source;

a plurality of LEDs of at least two different colors adapted to be coupled to the DC power source and to a common potential reference;

a light-transmitting enclosure surrounding the plurality of LEDs;

a current sink interposed between the plurality of LEDs and the common potential reference, the current sink comprising at least two switches corresponding to respective current paths of the at least two different color LEDs;

control means for periodically and independently opening and closing the at least two switches at high frequency and for generating a duty cycle thereby.

10. The lightbulb of claim 9 wherein the duty cycle is predefined and uniform, whereby the lightbulb permanently generates a single unalterable color of light.

11. A method for controlling current through an LED assembly comprising the steps of:

providing a memory location;

placing a numerical value in the memory location indicative of the duty cycle of a pulse width modulated waveform;

closing an LED circuit between supply and ground when the waveform is in one state, and opening the LED circuit when the waveform is in another state;

changing the numerical value in the memory location upon receipt of a new numerical value over a computer network.