| 摘要 |
PURPOSE:To improve the density of a device and retrieval speed by providing an objective lens and a pressure center at the center of a slider, installing a trapezoidal prism out of the slider and controlling tracking by means of rotation. CONSTITUTION:An optical beam 23 is made incident on a polarizing mirror 27 through optical devices 24 and 25 and the trapezoidal prism 26 whose apex angle is alpha and it forms an image on an optical disk medium 31 as an optical spot 32. The reflected light beam 33 forms the image on a photodetector 36 in a reverse coarse, and detects the error signal of focus and tracking. A focus driving means 37 and a tracking driving means 38 control the optical spot 32 in accordance with the signal. The slider 30 floats through an air layer with the medium 30, the objective lens 28 and a pressing point P are provided in the center of the slide, and the pressure point P is pressed by a pressure spring 40. Thus, the optical head is miniaturized and the density of the device and retrieval speed can be improved. |
