Abstract: An actuator (100) including: a housing (102); a driven member (104) movably disposed with respect to the housing; a magnet (114) associated with the driven member and a ferric member (112) for providing a magnetic attraction force between the driven member and the ferric member for providing a normal force (Fn) between the housing and driven member such that a friction force between the housing and driven member resulting from the normal force must be overcome to initiate a relative movement between the housing and driven member; and a magnetic drive system (118, 120) for overcoming the friction force and driving the driven member relative to the housing. The driven member can be a lens holder for holding a lens (106), in which case, the actuator can further include an image sensor (110) for acquiring image data through the lens.

Abstract: The invention relates to a micro electromechanical device (1?) for tilting a body (2) in two degrees of freedom comprising a carrier element (3) and a membrane (4), the body (2) being connected via the membrane (4) to the carrier element (3), wherein the body (2) and the carrier element (3) each comprise at least one electrode (5,6). The body (2) is tilted by means of electrostatic forces (7) between the at least one electrode (5) of the body (2) and the at least one electrode (6) of the carrier element (3) by an application of a voltage (V1,V2) to said electrodes (5,6) from a voltage source.

Abstract: 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.

Abstract: For magneto-optic data recording, permanent magnets are used to produce a magnetic field with a variable field strength. The field strength is varied by controlled rotation of the magnets about their longitudinal axis, which also allows inversion of the direction of the magnetic field. The magnets are oriented such that their combined fields produce a resultant force continuously substantially perpendicular to the recording medium despite rotation of the magnets.

Abstract: An actuator assembly for use in an optical disk information processing system is disclosed having improved performance characteristics for achieving a large radial movement frequency bandwidth. The actuator assembly includes an actuator body defining a rail channel for movement on a single rail. The device is configured so that the center of mass of the actuator body is above the friction surfaces between the rail and the rail channel. The actuator body includes an optical channel for receiving an optical beam to be focused on an optical disk. This optical channel is positioned between two focus supports which support a lens holder which is movable for focusing the incoming optical beam onto the optical disk. The focusing motor, including a coil and focusing magnets, is positioned below the center of mass of the actuator to achieve a balanced device. The radial drive assembly for the device includes a coil directly wound on the actuator body which encircles the optical channel and the rail channel.

Abstract: 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.

Abstract: 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).

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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).

Abstract: 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.