| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser driving apparatus and method whereby such a precise voltage that it is not excessive and not deficient as an output voltage for driving a laser-light source is outputted. SOLUTION: The laser driving method of the laser driving apparatus has a phase wherein when its laser driving circuit 3 is operated according to its laser-light emitting pattern for searching and an output voltage Va of its variable-output-voltage source 1 becomes a maximum output voltage, the output current of its variable-output-voltage source 1 is denoted as a maximum current Imax, and has a phase wherein the output voltage Va is reduced from the maximum voltage thereof, and the output voltage Va obtained when the reduced amount of the output current of the variable-output-voltage source 1 from the maximum current Imax becomes not smaller than the n% correspondence value of the maximum current Imax is denoted as a slice-level voltage Van, and further, has a phase wherein based-on the characteristic for indicating the correspondence between the pre-sensed output voltage Va and the pre-sensed current value I and based-on the slice-level voltage Van and the n% correspondence value of the maximum current Imax, the output voltage Va obtained when the sensed current I becomes such a current value as the boundary value between a nearly-constant saturated region and a linearly varying linear region is calculated as a varying-point voltage Va*, and moreover, has a phase wherein the varying-point voltage Va* is memorized as an optimum voltage Vopt, and the memorized optimum voltage Vopt is outputted from the variable-output-voltage source 1 in the case of an ordinary operation. COPYRIGHT: (C)2009,JPO&INPIT
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