Abstract: An information recording disc playback apparatus has an optical pickup for reading recorded information from a disc clamped on a turntable by a disc clamp mechanism while the disc is being rotated. The disc clamp mechanism comprises a presser member for pressing the disc against the turntable under magnetic forces, and a movable member supporting the presser member idly and movable by a drive mechanism for displacing the presser member toward and away from the turntable. After the disc has been pressed against the turntable by the presser member, the movable member is movable within a gap defined between itself and the presser member. By the movement of the movable member within the gap, the height of an optical pickup mounted on the movable member can be adjusted with respect to the recording surface of the disc.

Abstract: A disk drive according to a first embodiment includes a pickup movable along a radial direction of the disk and a reversing mechanism for moving the pickup from one side of the disk to the other side by rotating the pickup about an axis corresponding to the radial direction of the disk. In a second embodiment, there can be only one pickup which can reverse sides of the disk or a pickup on each side of the disk. The pickup(s) are moved along guide rails on either side of the disk and the guide rails are supported by rotatable base members. A linking arm links the two base members together so that rotation of one will cause rotation of the other. In a third embodiment, a pickup and a rack are supported on a slider for moving the pickup along the surface of a disk. The rack has three toothed surfaces including first, second, and third surfaces for engaging first, second and third feed screws, respectively.

Abstract: An optical component-driving device for driving an optical component along a tracking axis and/or a focusing axis includes a magnet, a yoke and a coil. The coil is fixed to a moveable member which houses the optical component to be moved. The coil is disposed in spaced, opposed relation to two opposite polarity surfaces arranged adjacent and planar to one another and disposed in the direction of tracking and/or focusing. The first polarity surface is provided by the facing surface of a polarized magnet. The second polarity surface is provided by one end face of a yoke, the other end face of which abuts the opposite polarity backing surface of the magnet.

Abstract: A disk clamping device for clamping either one of a disk having a small center hole, such as a compact disk, and a disk having a larger center hole, such as a video disk, to a turntable with which the diameter of the turntable can be increased to reduce the amount of bending and vibration of the disk while it is being played. A first hub for centering a disk having a small center hole is mounted on the disk drive shaft of the drive motor, while a second hub, separate from the first hub, is mounted on the other side of the disk playing position together with a clamper. The second hub has a clamping surface which is brought into contact with the surface of the disk having a small diameter hole when engaged with the disk drive shaft.

Abstract: An optical disc reading apparatus having a reduced overall height and simplified structure. The disc drive motor is mounted with its output shaft extending downward. A turntable is fixed to the output shaft below the body of the motor. A disc carriage is mounted so as to be movable only in a horizontal direction towards and away from the turntable, and a clamper clamps the disc once it has been conveyed by the disc carriage to the playing position on the turntable. A pickup is mounted below the turntable on the side of a loaded disc opposite both the motor and turntable. At least the objective lens of the optical pickup is lowered away from the turntable when the disc is being loaded to allow free movement of the disc toward the turntable.

Abstract: A disk loader for a compact or video disk player with which the disks tray can be extended nearly completely out of the player for receiving a disk to be played without having to increase the overall depth of the player body. A pair of retainers are provided extending parallel to a direction of conveyance of the disk by the disk tray. Racks are formed in at least on one side of the disk tray and on an adjacent one of the retainers. A pair of fixedly mounted guide members guide each of the retainers. A first pinion is engaged with the rack on the retainer, while a gear is engaged with the rack on the tray, the gear being fixed to the first pinion and having a larger diameter than the first pinion. A second pinion is mounted on the output shaft of a drive motor and engaged with the gear.

Abstract: A drive and support structure of an objective lens, for an optical information reading system for example, has a very much simplified construction. An objective lens and a focusing coil fixed thereto is placed in a hollow space formed in a magnetic circuit without any pole piece projecting into the focusing coil generally used in conventional arrangements. With this simplified construction, the total weight of driven parts is vary much reduced to improve a follow-up characteristic of a focus servo control system. At the same time, the size of the drive and support structure is made much smaller than conventional arrangement both in its diameter and its height.

Abstract: A lens driving device for an optical pickup unit includes a support structure for supporting an objective lens so that its optical axis is perpendicular to the surface of a recording medium while movements in the direction of the optical axis and in a direction perpendicular to the optical axis are permitted. The device further includes a driving structure for driving the objective lens in the direction of the optical axis and in the direction perpendicular to the optical axis respectively. The driving structure is made up of a magnetic circuit which forms a gap in which first and second coils connected to the objective lens are disposed so that driving forces in the direction of the optical axis and in the direction perpendicular to the optical axis are independently produced when suitable driving currents are supplied to the first and second coils.

Abstract: An information reading and reproducing apparatus in which a recording disc having an information-carrying face formed with recorded tracks is to be driven for rotation and which includes drive means operative to drive a signal pick-up means for movement radially of the disc at a velocity controlled by a velocity control device and to produce signals indicative of the locations of the pick-up spot relative to the tracks on the disc in a radial direction of the disc, the velocity control device comprising velocity detecting means operative to extract from said signals information indicative of the velocity of movement of the signal pick-up means with respect to the disc.