Acute Applied Technologies Inc.

Chin-Sung Liu

Li-Chung Peng

An-Ying Huang

A magnetic restoring device of actuator provides a sufficient magnetic restoring force for stably holding a movable part of actuator in a neutral position. The actuator acts as an objective lens driving device in an optical pickup. A non-contact magnetic restoring mechanism is provided for causing pickup to return to a neutral position after a focusing or tracking operation. The magnetic restoring device comprises magnets, two magnetic inductive members, and two yokes wherein magnets and yokes are opposite; one arc-shaped surface is formed on the magnet in the focusing direction; and the other one is formed on the magnet in the tracking direction. The magnetic inductive members are provided between the magnets and the yokes to form a magnetic circuit, thereby increasing a magnetic field intensity and sensitivity of actuator. The device increases a magnetic restoring force in the focusing and tracking directions respectively.

Magnetic restoring device of an actuator

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.

Electromagnetic actuator having specific coil arrangement for improving utilization rate of magnetic circuit thereof

A magnetic coil actuator which can provide a higher output but maintains the original volume and the same power consumption is disclosed. The coil actuator uses a movable magnetic coil which is adjusted of its shape to meet the magnetic field of a static magnet. The coil is suitably bent to have its two diametric sections falling into the magnetic lines of the magnet, so as to maximize the usage rate of the coil to the magnetic field. Therefore, the coil actuator provides a higher output applicable to a tracking or focusing device of a pickup head, and meets the requirements of high speed optical recording devices.

Magnetic coil actuator

An electromagnetic actuator for efficiently moving an objective lens along a focusing direction and a tracking direction. The electromagnetic actuator includes a flux generator, a first set of coils, a second set of coils and a magnetic piece. A first magnetic part and a second magnetic part of the flux generator are placed within a gap for generating smooth magnetic lines of force. The first set of coils moves the objective lens along the focusing direction. The second set of coils provide micro rotation around a shaft to the objective lens, and magnetic pieces are placed in the magnetic circuit adjacent to the gap. The objective lens holder is held at the neutral position relating focusing and tracking directions while the magnetic attraction forces are acting on the magnetic pieces.

Electromagnetic actuator for obtaining micro movement and micro rotation of an object

An objective lens holder applicable in a pickup head of an optical media device is disclosed. The lens holder overcomes the problems of unstable movement and complicated assembly of the conventional lens holders. The invented lens holder uses four stripe-like resilient supporting arms, which are made from a unitary sheetmetal by a press-cutting and a bending process, to support the lens carrier and the lens. One ends of the supporting arms are settled with a fixing member when the fixing member is resin-molded, and the other ends are linked with the lens carrier. Each supporting arm includes two strips which ensure the supporting arm moving stably in the tracking direction and the focusing direction respectively. The assembly is simplified by the unitary sheetmeetal workings and the resin-molding process.

Growing community of inventors

Miao-Li, Taiwan

Chin-Sung Liu