| 摘要 |
PURPOSE:To reduce size and weight by driving an objective lens in the direction perpendicular to its optical axis and information tracks in order to correct tracking errors. CONSTITUTION:The 1st, 2nd stationary yokes 61, 62 are constituted respectively of magnetic materials having high magnetic permeabilities and permanent magnets 71, 72 are respectively provided to these yokes 61, 62. The magnetic fluxes generated from the permanent magnets 71, 72 and a moving member 3A consisting of a permanent magnet passing concentratedly through the yokes 61, 62, spaces 81, 82, and a space 9. Hence, if the sectional shapes of these yokes 61, 62 are made into a square shape, the surfaces opposing to the moving member 3A of the yokes 61, 62 and the coils 101, 102 existing in these parts are exposed to stronger magnetic fields as compared to the other three surfaces and the coils 101, 102 existing in these parts. Now, when the electric current in the direction of the arrow is flowed to the coils 101, 102, the moving member 3A, that is, an objective lens 1, is moved by the interaction of the current and magnetic field in the right direction which is one of the directions of the arrows A. |
