LASER DRIVE HAVING LIGHT-INTENSITY CALIBRATION FUNCTION

摘要

PURPOSE: To provide a laser driving device provided with a means for appropriately calibrating the intensity of the output light of a laser used for an optical disk recorder or the like. CONSTITUTION: At the time of calibration, the laser 14 emits light with the control of a laser control part 15 and a photodiode 31 receives the light. Voltage signals corresponding to the light emitting levels to comparators 35 and 40 through a line 34. A minimum reference value CALVR1 and a maximum reference value CALVR2 are supplied to the comparators 40 and 35 through switches 41 and 36. A micro processor 20 stepwise increases the input value of a digital/ analog converter(DAC) 23 so that the voltage signal of the line is contained in a range between the minim/maximum reference values. The input values DACmin and DACmax of DAC 23, which are equivalent to the maximum/ minimum reference values, are obtained and are stored in a table 43. The efficient value E of DAC, which is obtained by the minimum/maximum reference values and the input values DACmin and DACmax, is stored in the table 43 and a current value for driving the laser 14 at a prescribed mode by the values is set.