Optical disc apparatus and defocus correcting method

Abstract

An optical disc apparatus in which a bias of a focusing error signal is changed to a value according to a recording power at timing corresponding to a predetermined address position before starting the recording and a defocus of an opposite polarity is preliminarily caused so as to set off a defocus which occurs at the start of the recording.

1 - 24 . (canceled) 
     
     
         25 . A recording method of recording information onto an optical disc, wherein when switching from a reproduction to the recording, a defocus of an opposite polarity is caused so as to reduce a defocus which occurs when the recording is started. 
     
     
         26 . An optical disc apparatus for recording information onto an optical disc, comprising:
 an objective lens for converging a laser beam onto said optical disc;   an actuator for driving said objective lens;   a photodetector for detecting reflection light from said optical disc;   a focusing error signal forming unit for forming a focusing error signal on the basis of the detection of said photodetector;   a driver circuit for controlling said actuator on the basis of said focusing error signal; and   a control circuit for controlling said focusing error signal forming unit,   wherein when switching from a reproduction to the recording, said control circuit previously sets a predetermined bias level into said focusing error signal forming unit.