U.S. Philips Corporation

Gerardus L Jansen

Henricus J Smulders

Pieter D Schuitmaker

Gerardus J Vos

Antonius T Peijnenburg

Leonardus G Bovee

Alexander Vorspaget

An actuator comprises a permanent magnet body (1) and coil means for cooperation with the magnet body. The magnet body is rotatable about an axis of rotation (7) between, for example two, stop positions. The coil means exclusively comprise at least one active coil section (9a, 11a) of an electrical coil, which coil section extends parallel to the axis of rotation of the magnet body and substantially faces a magnet pole in a stop position of the magnet body.

Actuator comprising a rotatable magnet body; actuator unit comprising

The invention relates to a lens mounting (11) for an electrodynamic device for recording and/or reading information in and/or from optically readable discs, which device comprises a frame with supporting means for guiding the lens mounting. The lens mounting comprises a first part (27) which cooperates with said supporting means and a second part (31) which is movable relative to said first part and which comprises the mount (32) for a lens system for focusing a radiation beam. The lens mounting (11) further comprises connecting means (33A, 33B and 35) which movably connect the first and the second part to each other. Respective opposite ends of the connecting means are embedded in the first part and the second part of the lens mounting by injection molding into a molding which is configured so that the relative position of the first and second parts are defined by the corresponding portions of one molding die.

Lens mounting for an electrodynamic device for recording on and/or

Apparatus for writing and/or reading information in an information surface of a rotating disc by means of a radiation spot (5) includes a one-piece injection-moulded or die-cast frame (11) and a motor unit (57) with a motor shaft (43) which carries a turntable (45) and which is journalled in the frame (11). The device further comprises an optical system with a movable lens system (17), and a lens-system driving device (13) with a movable lens carrier (15).

Disc reading apparatus with disc shoot journaled in frame

An apparatus for recording and/or reading information on an optically readable disc (3) includes a carrier (6) which can be driven along a first axis (4) in order to move a lens system (1) which is arranged on the carrier relative to the disc. The lens system is also driven along said first axis by drive means (33) which act directly, i.e. not via the supporting means (21, 22), in order to minimize the load exerted on the supporting means.

Electrodynamic device for translating a lens system

An apparatus reads and/or records information on a disc by means of a light beam, which disc rotates about an axis of rotation, and is driven by a drive spindle which is journalled in a spindle support, an objective 1 being moved along two parallel guides by means of a slide in a radial direction relative to the axis of rotation. All parts of an opto-electronic system for producing the light beam and for effecting a conversion between optical and electrical modulation may be arranged on the slide but may alternatively form part of a stationary opto-electronic system. At least the spindle support or the stationary opto-electronic system is supported by at least one of the guides, for example by means of supports and which are formed with locating stops which cooperate with the guides 9A and 9B.

Optical recording and/or reading device with spindle and optical

An apparatus for recording and/or reading information on an optically readable rotating disc (3) comprises a slide (6)which can be driven in a radial direction in order to move an objective (1) arranged on the slide along the disc. The objective is driven directly in the radial direction by radial drive means (33) which act directly, i.e. not via the bearing means (21, 22), on the objective.

Electrodynamic focus and radial slide drive for an optical disc system

In a data communication system comprising a plurality of data stations which are interconnected by a common communication medium, simultaneously occurring prospective users of the communication medium undergo an arbitration to determine which one will gain access to it at any time. The system according to the invention provides the arbitration without negatively affecting the capacity of the communication medium. In the system, arbitration takes place during the data communication to decide who will be the next user, arbitration and communication being effected in frequency bands which differ from each other.

Data communication system

An electrodynamic device translates an objective 1 along a path 4 in a radial direction relative to the axis of rotation 2 of an optical disc 3 and comprises a slide 6 on which the objective is arranged and a parallel-guide arrangement along which the slide is movable. It also comprises two stator magnets 7A and 7B, arranged on a stator yoke of a magnetizable material, and two drive coils 8A and 8B which are connected to the slide 6 and which can be translated in the magnetic field of the stator magnets. The slide 6 is movable on two guide rods 8A and 9B of a magnetizable material, which rods provide the parallel guidance of the slide 6 and also serve as parts of the stator yoke, air gaps 12A and 12B being formed between the permanent magnets and the drive coils being arranged around the guide rods.

Electrodynamic device for translating an objective

Synchronizing the phase of a locally generated clock signal with the phase of an input signal is usually effected by using a phase-locked loop, but this has a drawback that a certain run-in time is necessary to be sure that the phase of the clock signal is stable. The present arrangement comprises a delay line (2) having taps (3), the delay line being driven by a crystal oscillator 1. Clock signal versions C1(0), C1(90), C1(180) and C1(270) which are phase shifted relative to one another through 90.degree. available at the successive taps (3). A coincidence detection circuit comprising trigger circuits (9) and a combining network (10) detects the version of the clock signal whose ascending edge, for example, is located nearest to an ascending edge of the data signal, and this version is supplied as the clock signal at an output (8) by the selective control of switches (7) by control signals from the outputs (13) of the network (10).

Arrangement for synchronizing the phase of a local clock signal with an

An optical read apparatus for reading a disc-shaped record carrier. A read element is mounted on an adjusting member by means of which the read element is radially movable. Moreover, there is provided a deflection element for correcting the radial position of the scanning spot. In order to enable an arbitrary information unit on the record carrier to be read with a short searching time, the drive of both the adjusting member and the deflection element is controlled. In order to enable the adjusting member to be moved in a rapid and controlled manner there is provided a position indicator, which indicates the instantaneous radial position of the read element. Moreover, there is included a correction circuit which eliminates the adverse effect of inaccuracies in the position indicator on the searching time.

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Eindhoven, Netherlands

Gerardus L Jansen