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 which is independent of the absolute light power
level of the laser diodes. For generating the photodetector signal which
is independent of the absolute light power level of the laser diodes, a
switch for changing over the sensitivity of the photodetector is
provided, which switch is controlled by the modulator for generating a
uniform light power with a laser diode. A connecting line to the basic
apparatus and corresponding terminals for controlling the switch 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.