| 摘要 |
PURPOSE:To improve optical axis adjusting information and, at the same time, to monitor a recording beam and focus detecting beam, by providing a position of optical axis indicating section at a location separated by a desired distance from the location of the outgoing side focal point of a recording lens. CONSTITUTION:By placing a position of optical axis indicating section 20 on an X- and Y-axis moving tables 22 and 23 on a supporting table 21 at a location which is separated by a desired distance from the location of the outgoing side focal point of a recording lens 9, so that auxiliary lines engraved in the indicating section 20 can rspectively coincide with the moving direction of the X-axis moving table 22 and that of the Y-axis moving table 23 which is perpendicular to the moving direction of the moving table 22 when the optical axis is set to Z-axis, position of the optical axis can be indicated at locations corresponding to the moving center of a recording medium and to the radial position of the recording medium at the time of design. Moreover, since photodetectors 24-26 are arranged to the center of the indicating section 20, the optical axis can be adjusted to a desired center of optical axis by moving an optical spot position so that outputs of each photodetector can be uniformized, when the recording optical spot like the one shown by the dotted line is made incident. |
