Focus offset optimization for reading optically recorded data

Focus operation for an optical disk device

Focus operation for an optical disk device

Focus optical system and optical disc master exposure apparatus

Focus point switching

Focus position adjustment device and optical disc drive...

Focus pull-in method and optical disk device

Focus search apparatus and method

Focus search method and controller for digital disk

Focus search method and reproducing apparatus

Focus searching method and optical disc device

Focus servo actuating circuit and optical disk device...

Focus servo apparatus

Focus servo apparatus for multi-layer disc and method for operat

Focus servo circuit apparatus with automatic bias adjustments

Focus servo circuit for a magneto-optical disk recording and rep

Focus servo control device

Focus servo control device for optical disks having servo offset

Focus servo control method in optical disc device

Focus servo control system and disk reproducing system