Abstract: An electromagnetic actuator with an improved utilization rate of magnetic circuit for efficiently moving an objective lens on micro levels along a focusing direction and a tracking direction is disclosed. The electromagnetic actuator includes two homopolar parts spaced with a clearance small enough for generating magnetic force lines including a first and a second smooth portions which are preferably linear. The electromagnetic actuator further includes a first and a second actuating coil sets connected to the holder of the objective lens for moving the objective lens along the focusing and the tracking directions, respectively. The first and the second actuating coil sets are arranged around the homopolar parts with coil walls thereof substantially perpendicular to the first and the second smooth portions, respectively, so that they themselves move in the focusing and/or tracking directions in response to the currents and the magnetic force lines applied thereto to actuate the lens holder.

Abstract: An opener for opening the shutter door of a disk cartridge. The opener includes an opener beam having a slot section and a pin that passes through the slot section of the opener beam to be fastened onto a base metal plate. Therefore, the opener beam is able to slide with respect to the fixed pin within the opener slot. A first slot is also formed in the base metal plate so that a slider attached to the head section of the opener beam is able to slide freely inside the slot. In addition, the opener has a spring with one end fastened to the base metal plate while the other end is fastened to a spring lock pin of the opener beam. A second slot on the base metal plate permits the spring lock pin to slide inside the slot. In an alternative design, by using pins that fasten onto the base metal plate, there is no need to form first or second slots on the base metal plate.

Abstract: An apparatus for activating a disk clamper by magnetic restoring force is provided for an optical disk drive having a casing and a cartridge for carrying an optical disk along a path in the optical disk drive. A spindle motor is mounted below the casing that is made of material which can be induced by a magnet. A disk clamper includes a magnet mounted therein and has a central axle coaxial with a central axis of the spindle motor. The disk clamper and the spindle motor and respectively located on two sides of the disc when the cartridge is inside the optical disk drive for securely clamping the optical disk together. When the spindle motor moves upwardly, the disk clamper is moved downwardly to clamp the optical disk in the cartridge under action of magnetic force between the spindle motor and the magnet in the disk clamper.

Abstract: An apparatus for activating a disk clamper by magnetic restoring force is provided for an optical disk drive having a casing and a cartridge for carrying an optical disk along a path in the optical disk drive. A spindle motor is mounted below the casing that is made of material which can be induced by a magnet. A disk clamper includes a magnet mounted therein and has a central axle coaxial with a central axis of the spindle motor. The disk clamper and the spindle motor and respectively located on two sides of the disc when the cartridge is inside the optical disk drive for securely clamping the optical disk together. When the spindle motor moves upwardly, the disk clamper is moved downwardly to clamp the optical disk in the cartridge under action of magnetic force between the spindle motor and the magnet in the disk clamper.

Abstract: An apparatus for activating a disk clamper by magnetic restoring force is provided for an optical disk drive having a casing and a cartridge for carrying an optical disk along a path in the optical disk drive. A spindle motor is mounted below the casing that is made of material which can be induced by a magnet. A disk clamper includes a magnet mounted therein and has a central axle coaxial with a central axis of the spindle motor. The disk clamper and the spindle motor are respectively located on two sides of the disc when the cartridge is inside the optical disk drive for securely clamping the optical disk together. When the spindle motor moves upwardly, the disk clamper is moved downwardly to clamp the optical disk in the cartridge under action of magnetic force between the spindle motor and the magnet in the disk clamper.

Abstract: A disk loader for loading disk into a disk reader having a vertical protection panel and a retractable block structure. The vertical protection panel is used for restricting bare disk so that even if the disk reader is vertically placed, the disk cannot fall out during the disk-loading process. The retractable block structure is used for pushing one side of a disk cartridge so that even if the disk reader is vertically placed, the disk cartridge cannot fall out during the disk-loading process. Therefore, the disk reader can be horizontally placed or vertically placed without affecting the process of loading a bare disk or a disk cartridge into a disk reader. In addition, the disk loader can be designed to use a set of pre-loading arms for restricting a bare disk or disk cartridge, too.

Abstract: A vibration absorber includes at least one damping means attached to an optical disk drive for absorbing vibration of a base frame of the optical disk drive. The damping means includes at least one elastic member with proper stiffness and a damping coefficient and a rigid body providing mass and moment inertia effect.