U.S. Philips Corporation

Johannes M Hensing

Cornelius Antonius Hezemans

Robert H Munnig Schmidt

Robertus J Verhoeven

Karel G Koken

Johannes T Van De Veerdonk

Cornelis M Beijersbergen Van Henegouwen

Petrus J Blankers

Pieter A Schoneveld

Leo G Metzemaekers

Vittorio Bianchi

Gerardus F Gasseling

An apparatus having a frame (1) carrying a turntable (3) for supporting the information carrier, which turntable is rotatable about an axis of rotation (3A), a slide (9), which is movable between two end positions, with a scanning unit, guide spindles (5, 7) and a linear motor unit (17, 19) for the slide, and an electrically energizable clamping unit (21). In the non-energized condition the clamping unit clamps the slide in any arbitrary stationary position of the slide along its path and in the energized condition it does not clamp the slide. During operation of the device a control unit at least substantially simultaneously turns on a first energizing current to the motor drive unit and a second energizing current to the clamping unit at the beginning of a displacement of the slide and at least substantially simultaneously turns off the first energizing current and the second energizing current at the end of the displacement.

Looking slide drive for a disc scanner

A device for the recording and reproduction of signals on a cassette for a medium comprising a sliding cover which in the device can be moved between a closed position and an open position. The device has a receiving space into which the cassette can be inserted, after which by means of a pivotal lever the sliding cover is opened upon further insertion of the cassette, in that the lever moves from the first position to the second position and thereby moves the sliding cover from a closed position to an open position. The lever is arranged on a movable lever support which can be moved between a starting position and an end position. The sliding cover is opened by snap action.

Method and device for snap opening of a cover of a cassette

A device for inscribing and/or reading a magneto-optical disc (7), including a frame (1) carrying a turntable (5) which is rotatable about an axis of rotation (11), a slide (17) carrying an optical unit (19) a rectilinear guide (15) for the slide arranged on the frame, and a slide-drive unit (25). A sub-frame (3) is secured to the frame so as to be movable, and a further slide (57) to which, viewed along the axis of rotation, a magnetic unit (59) is secured at a location opposite to and spaced from the optical unit. The sub-frame carries a further rectilinear guide (55) for the further slide, which further rectilinear guide extends parallel to the rectilinear guide for the first-mentioned slide at least during operation.

Drive arrangement for the writing/reading heads of a magneto-optical

A device for inscribing and or reading a magneto-optical disc includes a turntable mounted for rotation about an axis of rotation, and an optical unit and a magnetic unit movably mounted opposite to and spaced from each other in a direction parallel to the axis of rotation. The optical unit and magnetic unit are mounted each to be movable in a plane transverse to the rotation axis. The magnetic unit includes a coil on a support which in turn is movably mounted on a displacement body which is radially moveable with respect to the axis. During operation a measurement and control system determines the radial position of the optical unit and the magnetic unit relative to each other in the radial direction, for controlling at least the radial position of the coil of the magnetic unit relative to an objective of the optical units.

Positioning system for the heads of a magneto-optical data recorder

A device for inscribing and/or reading a magneto-optical disc (7), comprising a frame carrying a turntable which is rotatable about an axis of rotation (11), an optical unit (19) which comprises an objective (21) and an actuator for moving the objective in a direction parallel to such axis of rotation, and, viewed along such axis, a magnetic unit (59) arranged opposite to and spaced from the optical unit. The optical unit and the magnetic unit are movable in a plane which is oriented transversely of said axis of rotation. The magnetic unit comprises a coil (131) arranged on a coil former (129) and a further actuator (24) for moving the coil in a direction parallel to the axis of rotation of the turntable. The device further comprises a measurement and control system for detecting, during operation of the device, the distance between a reference plane (R) of the magnetic unit and the magneto-optical disc and for controlling the position of the coil.

Control system for the magnetic head of a magneto-optical disc apparatus

A motor-compressor unit comprises a motor including a magnetizable stator; an armature oscillatable about the motor shaft axis; two coils arranged opposite each other on the stator; and a magnetizable core extending between the coils. The stator has opposed sections spaced from each other and arranged to define air gaps between such stator sections and the core at the end faces of the coils remote from each other, such air gaps being concentric about the motor shaft axis. A permanent magnet is disposed between each stator section and the core, a pole of each magnet facing the core. A plurality of pole elements is associated with the armature and is arranged such that oscillation of the armature causes one pole element to move into its respective air gap and another pole element to move out of its respective air gap. The coils and the core are arranged such that passage of an alternating current through the coils causes flux alternately to increase in a first air gap and to decrease in a second air gap and then to decrease in the first air gap and to increase in the second air gap. The compressor includes a linearly reciprocating piston, and a lever connecting such piston to the motor shaft.

Motor-compressor unit

A pivotally oscillating motor having magnetizable armature pole elements arranged to cooperate with respective air gaps. Alternating current through a stator coil aids to the permanent magnet flux through one air gap while it reduces that in another air gap, so that alternately one or the other pole element is pivotally attracted into its respective air gap.

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Eindhoven, Netherlands

Johannes M Hensing