RECORDING AND REPRODUCING DEVICE

摘要

PURPOSE:To read a pre-record signal after detecting the reflected light when an information signal is recorded by setting different levels between the frequency band of the information signal and the frequency band of the pre-record signal. CONSTITUTION:The laser light of a semiconductor laser generator 10 is modulated by a signal modulator 12 via a laser modulator 11 and controlled to form a focal point on a recordable optical disk 1 through a beam splitter 7, a mirror 6 and an objective lens 3. The frequency band of the information signal which is reflected by the disk 1 and made incident to a photodetector 8 via the splitter 7 is set at a different level from the frequency band of the pre-record signal of a pre-group on the disk 1. Thus it is possible to read independently the pre- record signal by transmitting both information and pre-record signals contained in the output of the detector 8 through a reproduction amplifier 14 and an LPF15 even in case the information signal supplied to an information signal input terminal 13 is recorded to the disk 1.