Patent ID: 7547113

Claim:
A LED-based lighting device, comprising: a light source unit having at least a red LED, a green LED and a blue LED; a light display unit having an appropriate transparency as a lamp shade or lamp screen to show unlimited number and flicker-free of color lights emitted from said LEDs of said light source unit; and a control unit causing said light source unit to emit mixing color light, having at least three potentiometers, at least three constant current sources, at least three current limiters, and at least three control buttons, wherein said potentiometers, said constant current sources, said current limiters are series-connected in the foregoing order into at least three current paths respectively; each said current path is connected to said LEDs of a specific color; the outputs of said potentiometers are controlled by said control buttons respectively; wherein DC voltages derived from a power source are distributed to said potentiometers and said constant current sources; said potentiometers apply various voltages to said constant current sources based on the dynamic adjustment of said control buttons; said constant current sources thereby deliver corresponding amounts of current to said LEDs, causing said LEDs to emit light from darkness to full brightness.