Fujitsu Corporation

Toshitaka Iwamoto

Masateru Sasaki

Yasukiyo Kunimatsu

Hirataka Ukai

Shigeru Juman

Hidenori Saitou

Tomoo Sukagawa

Tatsutoshi Nagasaki

Masao Uchiyama

Shigenori Yanagi

Shigeru Arai

Akira Minami

Shigeyoshi Tanaka

Hidenori Saitoh

A miniaturized optical disc memory is receivable in a slot, of about 17 mm height, normally accommodating a floppy disc drive. A base includes a base plate with integral, peripheral sidewalls and an internal lateral partition wall which define a cartridge receiving slot on the upper surface of the base plate. First and second support plates extend from the partition wall to the rear peripheral sidewall of the base and define respective, first and second upper mounting surfaces and lower first and second cavities respectively receiving an ejection motor and a fixed optical system, individual optical components being mounted and aligned on integral, precision machined blocks in the second cavity for transmitting a laser beam and receiving a reflected beam along a central, longitudinal optical axis beneath the base plate. A first base plate aperture accommodates a lens carriage driven in reciprocating motion along the axis for receiving and redirecting the laser beam vertically for scanning an optical disc and receiving a reflected beam and redirecting same to the fixed optical system. The movable optical system is locked in a rest position and is released by insertion of a cartridge to permit scanning movement thereof. A disc drive unit is mounted beneath the base plate for reciprocating vertical movement through a second aperture therein to a raised position for engaging and driving, in rotation, an optical disc of a cartridge inserted into the apparatus and to a lowered position for releasing the cartridge and permitting ejection thereof.

Optical memory apparatus having a base with a unitary and integral optical component mounting portion and a precision mounting surface for mounting an optical component

A miniaturized optical disc memory is receivable in a slot, of about 17 mm height, normally accommodating a floppy disc drive. A base includes a base plate with integral, peripheral sidewalls and an internal lateral partition wall which define a cartridge receiving slot on the upper surface of the base plate. First and second support plates extend from the partition wall to the rear peripheral sidewall of the base and define respective, first and second upper mounting surfaces and lower first and second cavities respectively receiving an ejection motor and a fixed optical system, individual optical components being mounted and aligned on integral, precision machined blocks in the second cavity for transmitting a laser beam and receiving a reflected beam along a central, longitudinal optical axis beneath the bass plate. A first base plate aperture accommodates a lens carriage driven in reciprocating motion along the axis for receiving and redirecting the laser beam vertically for scanning an optical disc and receiving a reflected beam and redirecting same to the fixed optical system. The movable optical system is locked in a rest position and is released by insertion of a cartridge to permit scanning movement thereof. A disc drive unit is mounted beneath the base plate for reciprocating vertical movement through a second aperture therein to a raised position for engaging and driving, in rotation, an optical disc of a cartridge inserted into the apparatus and to a lowered position for releasing the cartridge and permitting ejection thereof.

Optical memory apparatus having planar printed circuit board mounted therein

Optical memory apparatus having turn table unit mounted by a plate having an integral guide portion to a supporting base

Optical memory apparatus having a supporting base with an integral,

A system for obtaining an optimum focusing position in an optical disc system. An optical beam is impinged onto a track of an optical disc, and a reflection signal having information regarding an intensity of an optical beam reflected by an optical disc is obtained. A predetermined frequency component, the frequency component being generated by a modulation caused by an existence of a pit on a track of the optical disc in a reflecting signal, is extracted from the reflection signal. Then a focus position in which a maximum intensity of the extracted frequency component is obtained is searched by changing the focus position of the optical beam. Further, the above system is incorporated in a focus servo control system for maintaining an optimum focusing position in an optical disc system during reading and writing operations, to determine an optimum offset value which is to be adjusted to compensate an error arisen from a construction of the focus servo control system, during an offset adjusting operation.

System for obtaining optimum focusing position in optical disc system

An optical disk access system capable of varying the focus position of a beam spot illuminating the optical disk. The focus position of the beam spot is varied in accordance with a mode of operation of the optical disk system. The various focus positions are automatically selected by the optical disk access system by intentionally vibrating the beam spot in a radial direction of the optical disk and detecting the amount of light reflected from the optical disk while varying a signal that changes the focus position of the beam spot. The optical disk system automatically selects a value of the signal determining the focus position of the beam spot that corresponds to maximum values derived from the light reflected from the optical disk.

Optical disk access system

An optical storage apparatus for storing and reading information on an optical disk with an optical beam, including a tracking servo system having an objective lens, which is driven in a focusing direction F and a tracking direction T by a lens actuator, and a tilting mirror, which is rotated by a mirror actuator. The tracking servo system eliminates beam shift by controlling the lens actuator and the mirror actuator to position the lens and the mirror so that the laser beam always passes through a back focal point of the lens located on the opposite side of the lens from the optical disk. As a result, the laser beam proceeds from the lens to the disk along a path which is parallel with the optical axis of the lens and strikes the disk perpendicularly. Accordingly, the return path of the laser beam reflected by the surface of the disk coincides with the incident path of the laser beam, and no beam shaft is experienced.

Tracking servo system for controllably projecting an optical beam on an

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Kawasaki, Japan

Toshitaka Iwamoto