| 摘要 |
PURPOSE:To control an irradiation position with high accuracy and response using a compact of a inexpensive actuator by controlling a relative position of a plurality of optical beams which irradiate a recording medium using a wedge prism. CONSTITUTION:A light relay uses a wedge prism 15. Then, a member which can be rotated freely and carries this wedge prism 15 is operated by an actuator 17 which is a positioning means operated according to this wedge prism 15. In this case, even if a deviation from an optical axis of an optical beam is canceled and the prism 15 is rotated, it becomes possible to allow the optical beam to enter nearly a center of an objective lens 9. Thus, by selecting a plate thickness of the wedge prism 15 properly, the optical beam enters an incidence pupil of the objective lens 9, thus preventing light from being kicked. |
