| 摘要 |
The invention relates to a reproduction or recording apparatus for different optical recording media, which differ for example with regard to their storage density, are scanned by different means and have a photodetector arrangement that is jointly used for the different recording media and scanning means, which arrangement provides a photodetector signal PD out which is independent of the absolute light power level of the laser diodes LD1, LD2. For generating the photodetector signal which is independent of the absolute light power level of the laser diodes, a switch SW for changing over the sensitivity of the photodetector is provided, which switch is controlled by the modulator MD for generating a uniform light power with a laser diode LD2. A connecting line to the basic apparatus and corresponding terminals for controlling the switch SW are advantageously obviated as a result. The application of the invention is envisaged for reproduction or recording apparatuses of different optical recording media in which a modulation of the laser current is provided for generating a uniform light power. |
