It is possible to obtain preferable recording characteristic and
reproduction characteristic by considering irregularities of unique
characteristics of an LD or the like mounted on an information recording
and reproduction apparatus as well as characteristics of an optical disc
used. In the information recording and reproduction apparatus, a light
source such as a laser diode is driven by a laser drive signal so that a
laser beam for recording or reproduction is emitted from the light
source. Moreover, the laser drive signal is superimposed by a
high-frequency signal of a predetermined frequency so as to eliminate
effect of the return light from the optical disc. The information
recording and reproduction apparatus superimposes the high-frequency
signal by using a high-frequency signal level during recording which is
different from a high-frequency signal level during reproduction.