An information recording and reproducing apparatus performs information
recording and reproducing on an optical disc having a recording track
wobbled by a predetermined frequency. The apparatus includes an optical
pickup which irradiates a laser light on the optical disc and receives
the laser light reflected by the optical disc to output an electric
signal corresponding to the laser light, a push-pull signal generating
unit which includes a sample-hold unit and generates the sample-hold
push-pull signal and the non-sample-hold push-pull signal from the
electric signal, a sample-hold circuit which samples and holds the
push-pull signal, a recording clock generating unit which generates a
recording clock synchronized with the wobble signal based on the
sample-hold push-pull signal during recording and based on the
non-sample-hold push-pull signal during reproduction, and a phase
adjusting unit which adjusts the phases of the non-sample-hold push-pull
signal and the sample-hold push-pull signal.