Focus control system

Focus controlling apparatus and method, and optical disc drive

Focus detecting optical head

Focus detection mechanism and optical head and optical storage d

Focus detection system for an optical disk drive using photo sen

Focus detector which serves to split off a portion of a detected

Focus draw-in system for optical disc device

Focus drive circuit and focus search method based on relative po

Focus error detecting device

Focus error detecting device

Focus error detecting method and optical head using the same

Focus error detection system for an optical recording/reproducin

Focus error detection using an equal path length lateral shearin

Focus error signal generation using a birefringent lens with...

Focus error signal generation using a birefringent plate...

Focus error signal generation using confocally filtered detectio

Focus error signal generation using two polarizers in...

Focus jump control apparatus of a player for multilayer recordin

Focus jump device for reproducing information from a storage...

Focus layer jump control circuits and methods of controlling...