Optical tracking system for positioning a beam of light

Optical tracking system utilizing three photo-detectors

Optical turntable system with reflected spot position detection

Optical type disc with V-shaped groove and optical type reproduc

Optical type head device

Optical type information read/write apparatus

Optical type information recording medium having specified pit a

Optical type information reproducing device

Optical type pickup apparatus with lens holder supported by fram

Optical unit actuator for information recording/reproducing appa

Optical unit for inscribing and/or scanning an information track

Optical unit for optically scanning an information surface, and

Optical unit having a radiation source, a detector and a grating

Optical video disc structure

Optical video disc structure

Optical video or data tape record and playback apparatus

Optical wavefront modifier

Optical wavefront modifier including a series arrangement of...

Optical waveguide recording medium playing apparatus

Optical waveguide recording medium playing apparatus