Optical pickup actuator having a magnetic flux-controlling member

Abstract

Disclosed is an optical pickup actuator capable of regulating quantity of a leakage magnetic flux to minimize a phase change of an objective lens. The optical pickup actuator according to the present invention comprises a moving part having an asymmetric structure with respect to the objective lens, and a driving force of the moving part is generated by a magnetic circuit constituting of permanent magnets, a yoke and coils. In the vicinity of the magnetic circuit, a sub coil portion of the focusing coils and a magnetic flux-controlling member are provided for interlinking with a leakage magnetic flux generated from the magnetic circuit and for controlling quantity of the so generated and interlinking leakage magnetic flux, respectively. In the so constructed optical pickup actuator according to the present invention, the phase change of the objective lens in a rotational vibration mode, particularly in a pitching mode can be minimized by changing the moment of force generated from the side of the coil outside of the effective magnetic field space and influencing the moving part.

Dependencies are inferred from the claim text.