METHOD AND ARRANGEMENT FOR REGULATING THE LIGHT POWER OF A SCANNING BEAM IN AN APPARATUS FOR READING FROM OR FOR WRITING TO OPTICAL RECORDING MEDIA

摘要

In order to compensate for so-called clipping effects, it is proposed, in an apparatus for reading from and/or writing to an optical recording medium in which the light power of a laser diode (1) is to be set to a plurality of light power levels, to perform a calibration to a specific light power level (LP2) before the actual regulation of the light power. On account of the calibration, the instantaneous gradient of the characteristic curve which describes the dependence of the laser light power on the laser diode current can be inferred in order, on the basis of this information, to take account of a change - caused, for example, by ageing or clipping effects - in the characteristic curve gradient in the course of the subsequent regulation of the light power of the scanning beam generated by the laser diode (1).