Objective lens driving device

一种薄而紧凑的物镜驱动装置，光束通过由镜座内相邻的聚焦线圈和寻轨线圈围着的空间。按光盘种类对装置中的物镜高精度定位以切换多个物镜。磁性物质设在镜座内，与中心滑动轴一起径向外伸，设在垂直于磁间隙构成的平面内，且在间隙外侧。本装置可阻止由供流装置例如FPC的阻力引起的物镜位置移动。为此，使第一和第二物镜的布置角相对滑动轴轴中心有一定位移量，以该位移量设置磁性物质和磁铁相对于该轴中心的磁路布置角。 It is an object to perform a thin and compact design of the objective lens driving device. In order to achieve the above object, optical beam (8) is passed through a space surrounded by a tracking coil (4) and a focusing coil (5) which are adjacent to each other and fixed in a holder (3). Further, it is another object to position the objective lens with high precision in an objective lens driving device for switching a plurality of objective lenses in accordance with the type of an optical disc. In order to achieve this object, magnetic substances (12-1) to (12-(4) which are radially extended with the sliding shaft (6) at the center are provided in the lens holder (3), and the magnetic substances are located within a plane perpendicular to the plane constituting the magnetic gap and at the outside of the magnetic gap. Still further, in an objective lens driving device it is another object to prevent the occurrence of positional displacement of the objective lens due to resistance force of current supply means such as FPC. To achieve this object, a first objective lens (7-1) and a second objective lens (7-2) are arranged so that the objective lens arrangement angle (20) at which the first and second objective lenses are arranged with respect to the shaft center of the sliding shaft (6) is displaced, by a predetermined amount, from the magnetic circuit arrangement angle (13) at which the magnetic substances (12) and the magnets (2) are arranged with respect to the shaft center of the sliding shaft (6).