| 摘要 |
PURPOSE:To correct the asymmetry between a beam spot formed in the focus deviation direction and a recording track and to improve the correlation between the focus deviation value and the displacements of various characteristics of an optical pickup device by setting a semiconductor laser element so as to tilt the meridional surface of the light beam projected on an optical disk in the tangent direction of the recording track of the optical disk by a prescribed angle. CONSTITUTION:The light beam radiated from a light transmission/reception composite element 3 is made incident on an objective lens and then projected on a signal recording surface of an optical disk 101. In the case, the element 3 is set so that the meridional surface of the light beam is set by a prescribed angle, i.e., about 45 deg. to the tangent direction of a recording track of the disk 101. Thus it is possible to correct the asymmetricalness defined on the basis of the tangent of a beam spot produced on the disk 101 according to the focus deviation direction. As a result, the characteristic of an optical pickup device are improved to the focus deviation. |
