Patent ID: 7365718

Claim:
A light emitting element drive apparatus wherein a plurality of light emitting elements of different drive voltages required for emitting light are connected in parallel and one or more light emitting elements among the plurality of light emitting elements are driven, comprising: a plurality of drive circuits connected to corresponding light emitting elements of said plurality of light emitting elements and driving the corresponding light emitting elements with luminances based on set values; a decision circuit for deciding a drive voltage value required for the highest light emission among one or more light emitting elements driven to emit light based on drive states of said plurality of drive circuits; and a power supply circuit for supplying a drive voltage to said plurality of light emitting elements in response to the decision result of said decision circuit, wherein said power supply circuit includes a down-converted power supply for down-converting a supplied power supply voltage to any value down to the drive voltage value required for the light emission of the light emitting elements and supplying the down-converted power supply voltage as said drive voltage to the target light emitting elements for the light emitting elements having values of drive voltages required for emitting light smaller than the value of said power supply voltage.