Victor Company of Japan, Limited

Junji Kuroda

Koji Tanaka

Masayuki Suzuki

Takaro Mori

Toru Yamagishi

Yasuo Haneji

Yoshihiko Honjo

Noriyoshi Kokubo

Kunihisa Matsuzaki

An optical recording/reproducing system for optically recording and reproducing an information signal on and from an optical disc (31) to be recorded with a plurality of track turns includes a light source (52); an optical head (45b) carrying an objective lens (62) for directing a light beam from the light source (52) to one of the track turns, and a tracking servo actuator for displacing the light beam within a movable range to perform both track feed and tracking servo operations for one of the track turns; the optical head (45b) being stationary with respect to the optical disc (31) while performing the track feed and tracking save operations by displacing the light beam in a radial direction of the optical disc; and a recording area on the optical disc having a radial distance equal to or smaller than the movable range of the tracking servo actuator.

Compact optical disc recording/reproducing system

The invention relates to a system for detecting the height fluctuations of a surface on a recording medium in an optical recording or reproducing apparatus. A light source emits a main light beam for recording or reproducing. An optical system, including an objective lens, focuses the main light beam into a spot on the surface. A first reflecting mirror introduces a sublight beam into the peripheral part of the main light beam. The sub-light beam advances in a forward path through the objective lens to be projected onto the recording surface and reflected thereby. The sub-beam returns again through the objective lens along the peripheral part of the main light beam, but on the opposite side from said forward path. A second reflecting mirror extracts the sub-light beam in the return path out of the light to operate a detector which detects fluctuations in the distance between the objective lens and the recording surface and to produce control signals maintaining a constant distance between the objective lens and recording surface.

System for detecting height fluctuations of a surface on a recording

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Zama, Japan

Junji Kuroda