Patent ID: 7960919

Claim:
An illumination apparatus, comprising: a plurality of bridge rectification circuits corresponding to respective colors of light, each bridge rectification circuit receiving and rectifying an input AC voltage; being formed from a bridge connection of a plurality of unit series circuits each of which is formed from a series connection of a plurality of light emitting diode elements, the number of light emitting diode elements differing between at least two of the unit series circuits; and being associated with a transistor, the input AC voltage being applied across first and second nodes of the bridge rectification circuit, and the transistor having a first end coupled to a third node of the bridge rectification circuit and a second end coupled to a fourth node of the bridge rectification circuit, a first one of the unit series circuits including a rectifying diode for coupling the anode side of the first one of the unit series circuits to the first node of the bridge rectification circuit, a second one of the unit series circuits including a rectifying diode for coupling the cathode side of the second one of the unit series circuits to the first node of the bridge rectification circuit, a third one of the unit series circuits including a rectifying diode for coupling the anode side of the third one of the unit series circuits to the second node of the bridge rectification circuit, and a fourth one of the unit series circuits including a rectifying diode for coupling the cathode side of the fourth one of the unit series circuits to the second node of the bridge rectification circuit, such that the emitted light quantity for said bridge rectification circuits can be independently controlled, one or more of the light emitting diode elements being associated with a fluorescent material for maintaining emission of light from the one or more light emitting diode elements associated with the fluorescent material, for each bridge rectification circuit, the driving current for the light emitting diode elements is controlled by the transistor in response to a signal indicative of a comparison between a reference voltage and a voltage indicative of a light quantity output from the light emitting diode elements as measured by a photosensor, the reference voltages for at least two of the bridge rectification circuits being set such that when the light outputs of the at least two bridge rectification circuits are combined the combined light output is a desired light output.