Color variations in a dimmable lighting device with stable color temperature light sources
DCFirst Claim
1. A lighting device comprising:
- two input terminals to receive a dimmer signal from a dimmer and alternating current (AC) power, wherein the dimmer signal indicates a dimming level;
a first light source having a stable first color temperature;
a second light source having a stable second color temperature;
a light source driver, coupled to the first light source and the second light source and to the input terminals to supply a first drive current to the first light source and a second drive current to the second light source; and
a light source driver controller, coupled to the light source driver, to cause the light source driver to vary the first and second drive currents in response to changes in the dimming level indicated by the dimmer signal, wherein varying the first and second drive currents varies a color temperature of the lighting device.
4 Assignments
Litigations
0 Petitions
Accused Products
Abstract
A method and system allow a lighting device having light sources with multiple color temperatures to vary a color temperature of the lighting device in response to changing dimming levels. The light sources are non-incandescent light sources, such as light emitting diodes and/or gas-discharge lights. A dimmer circuit provides a dimming signal that indicates a selected dimming level. The lighting device includes a light source driver and a light source driver controller that cooperate to vary drive currents to the light sources in response to the selected dimming level. By varying the drive currents in different relative amounts, the color temperature of the lighting device changes in response to dimming level changes. In at least one embodiment, changes in the color temperature of the lighting device in response to the dimming level changes simulates the color temperature changes of an incandescent light source.
391 Citations
19 Claims
-
1. A lighting device comprising:
-
two input terminals to receive a dimmer signal from a dimmer and alternating current (AC) power, wherein the dimmer signal indicates a dimming level; a first light source having a stable first color temperature; a second light source having a stable second color temperature; a light source driver, coupled to the first light source and the second light source and to the input terminals to supply a first drive current to the first light source and a second drive current to the second light source; and a light source driver controller, coupled to the light source driver, to cause the light source driver to vary the first and second drive currents in response to changes in the dimming level indicated by the dimmer signal, wherein varying the first and second drive currents varies a color temperature of the lighting device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method of varying a color temperature of a lighting device, the method comprising:
-
receiving a dimmer signal on at least one of N input terminals, wherein the dimmer input signal indicates multiple dimming levels over time and N is a positive integer less than or equal to four (4); receiving power from a voltage source on at least two of the N input terminals; supplying a first drive current to a first light source, wherein the first light source has a stable first color temperature; supplying a second drive current to a second light source, wherein the second light source has a stable second color temperature; varying the first and second drive currents in response to changes in the dimming levels, wherein varying the first and second drive currents varies a color temperature of the lighting device. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19)
-
Specification