Focus entry device of optical disk system and focus servo device using same

摘要

The present invention relates to a focusing lead-in circuit of an optical disc system that receives reflected light from a disk to detect a focus sum signal and a focus error signal, and inputs these signals to turn on a loop of focusing servo. The driving signal for the input by inputting the pulse signal of the control circuit and the control circuit to turn on the loop switch according to the output of the point-in-time acquisition circuit and the point-in-time acquisition circuit which inputs and detects the focus-in point. A driving signal generating circuit for outputting the signal is completed to quickly complete the focus drawing operation.