Magnetic yoke, and drive arm of optical read-write head of using the yoke

Abstract

The invention is a magnetic yoke and an optical read-write head drive arm using the magnetic yoke. And the magnetic yoke is U-shaped and comprises a bottom wall, a first side wall and a second side wall, where the first side wall comprises a middle region whose permeability is lower than that on its edge, and the optical read-write head comprises a base, an objective seat, a voice coil motor and a hanging system, where the objective seat is provided with a round opening, the voice coil motor comprises a pair of magnetic yokes, a pair of magnets, a focusing coil and several tracking coils, and the hanging system comprises several strings and a fixed piece, where one end of the string is fixed to the objective seat and the other end is fixed to the fixed piece, and the fixed piece is fixed with the base. And the invention makes internal magnetic field of the magnetic yoke more distributed more uniformly and makes the coil bear force more stably.

Description

【Technical field】 [0001] The invention relates to an optical read-write head, in particular to a magnetic yoke for a voice coil motor of the read-write head and an optical read-write head driving arm. 【Background technique】 [0002] An optical data storage device usually includes an optical-mechanical module and an optical read-write head. The optical read-write head is located on the slide rail of the optical-mechanical module, and the optical read-write head is driven by a transmission mechanism of the optical-mechanical module to perform rough tracking on the slide rail. The optical read-write head includes a driving arm, and the driving arm carries a focusing objective lens for micro-tracking and focusing. A laser beam is projected onto a data track of an optical disc through the optical read-write head for reading or writing optical data into the optical disc. [0003] An optical read-write head driving arm disclosed in the prior art includes an objective lens, an obj...

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Problems solved by technology

[0008] However, in the optical read-write head driving arm disclosed in the above-mentioned prior art, since the magnetic field formed by the magnet in the yoke is unbalanced, the magnetic induction intensity in the middle of the magnetic field is relatively large, while that in the periphery of the yoke If the partial magnetic induction intensity is small, the Lorentz force suffered by the focusing coil and the tracking coil in the middle of the magnetic field is relatively large, while the Lorentz force suffered by the peripheral part of the magnetic field is small, that is, the force Unbalanced, which will affect the accuracy of the optical read-write head to read and write data

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