Appliance with an improved solid state device lighting
View Patent ↗An appliance includes a cabinet, a solid state lighting device assembly integrated in the cabinet, and a power controller coupled to the solid state lighting device assembly for supplying electrical power to the solid state lighting device lighting assembly. The power controller is configured to provide a pulse modulated power signal to the solid state lighting device assembly that has a duty cycle. Each solid state lighting device in the solid state lighting device assembly cycles on and off in accordance with duty cycle.
1. An appliance comprising:
a cabinet;
a solid state lighting device assembly integrated in the cabinet;
a power controller coupled to the solid state lighting device assembly for supplying electrical power to the solid state lighting device assembly, the power controller being configured to provide a pulse modulated power signal with a variable current drive to the solid state lighting device assembly, the pulse modulated power signal having a duty cycle of 30 hertz or greater; and
wherein each solid state lighting device in the solid state lighting device assembly cycles on and off in accordance with the duty cycle to allow the solid state lighting device to be perceived as continuously on.
2. The appliance of claim 1 , wherein the appliance is a refrigerator.
3. The appliance of claim 2 , wherein the solid state lighting device assembly is a display for the refrigerator, an interior lighting module or an exterior lighting module.
4. The appliance of claim 1 , wherein the appliance is a dishwasher, air conditioner range or washer.
5. The appliance of claim 1 , further comprising a duty cycle adjustment module coupled to the power controller, the duty cycle adjustment module being configured to adjust the duty cycle of the power signal for the solid state lighting device assembly in response to a determined environmental light state.
6. The appliance of claim 5 , wherein the duty cycle adjustment module is user operated.
7. The appliance of claim 5 , further comprising a time of day module coupled to the power controller, the time of day module controlling the duty cycle of the power signal based on a time of day.
8. The appliance of claim 7 , wherein the duty cycle of the power signal during daylight hours has a higher rate, and the duty cycle of the power signal during nighttime hours has a lower rate.
9. The appliance of claim 1 , wherein an OFF period of the duty cycle and an ON period of the duty cycle are not equal.
10. The appliance of claim 9 , wherein the OFF period of the duty cycle has a longer time duration than the ON period of the duty cycle.
11. The appliance of claim 1 , wherein the appliance further comprises an ambient light detector coupled to the power controller, the ambient light detector controlling a modulating input signal used to control a rate and period of the duty cycle, wherein in a detected bright light state, the modulating input signal controls the duty cycle to have a higher repetition rate than in a detected low light state.
12. The appliance of claim 1 , wherein both the duty cycle and a frequency of the power signal are variable.
13. The appliance of claim 1 , wherein the solid state lighting device assembly is an assembly of light emitting diodes, organic light-emitting diodes or polymer light-emitting diodes.