Patent ID: 6829414
Filing Date: 2004-12-07
Classification: H04N

Abstract:
A multi-beam scanning apparatus, comprising:a scanning unit that has a plurality of semiconductor lasers and scans laser beam emitted from said plurality of semiconductor lasers; and a controller that transmits a standard signal associated with a control of said plurality of semiconductor lasers to said scanning unit, wherein said controller comprises a standard signal generator that generates and outputs a sequence of pulse signals as the standard signal, the sequence of pulse signals having a plurality of common pulse signal sections that correspond to said plurality of semiconductor lasers, each of said plurality of common pulse signal sections having a peculiar waveform characteristic depending upon a corresponding semiconductor laser, wherein said scanning unit comprises: a plurality of laser drivers that respectively drive a corresponding semiconductor laser among said plurality of semiconductor lasers in accordance with the standard signal; a standard voltage generator that converts the sequence of pulse signals to a sequence of standard voltage signals that correspond to said plurality of semiconductor lasers and have a plurality of standard voltage ranges; and a standard voltage setter that detects each of the plurality of common pulse signal sections in accordance with the waveform characteristic, and transmits each value of the plurality of standard voltage ranges to a corresponding laser driver in accordance with a detected common pulse signal section, each of said plurality of laser drivers controlling the corresponding semiconductor laser in accordance with a value of a corresponding standard voltage range.