| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a plastic objective lens in order to improve mass productivity and reduction in weight, and to decrease a coma aberration that is caused when the environmental temperature changes. <P>SOLUTION: A pickup includes: a first and second objective lenses 33 and 34; an objective lens driver 51 as a coma generator that generates coma in a light beam passing the first and second objective lenses; a first collimating lens 36 converting the angle of divergence of the passing light beam; and a collimating lens driver 48 that corrects spherical aberration. The first objective lens 33, which is made of plastic, is attached such that the optical axis of the light beam guided by a first light guiding optical system 28 is substantially aligned with the optical axis of the first objective lens. The optical pickup is adjusted so as to be tilted at an angle that optimally corrects the initial coma aberration due to the first objective lens. When a first optical disc is reproduced, a tilt correction mechanism is not used. When a second optical disc is reproduced, the tilt correction mechanism is used in order to obtain the optimal reproduction environment. <P>COPYRIGHT: (C)2011,JPO&INPIT |
