| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a tilt sensing optical-system which has an optical system specially designed for tilt sensing separately from an optical pickup body, and directly senses relative tilt between an optical disk and an objective lens. <P>SOLUTION: The tilt sensing optical-system is provided with a light source 1, a coupling lens 2, an optical-path separation element 3, a deflection mirror 4 disposed on a movable part 6 of an actuator, beam-diameter regulating means 7 for regulating a diameter of a beam reflected from an optical disk, and a separation-type photo-receiving element 8 for receiving the beam that has passed through the beam-diameter regulating means. The beam from the light source 1 is introduced to the optical disk 9 by the deflection mirror 4; the reflected beam is moved backward on the optical path through the deflection mirror 4 again; the optical path is separated from the path from the light source by the optical-path separation element 3; then the beam diameter is regulated by the beam-diameter regulation means 7 and the light is received by a photo-receiving face of the separation-type photo-receiving element 8; and then relative tilt between the optical disk and an objective lens is obtained using a difference signal of a signal outputted from each of photo-receiving parts. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
