| 摘要 |
PURPOSE:To reduce the dimension from the upper part of a lens holder to the lower part of an optical system and to make the profile thin by irradiating an objective lens with light from the optical system through a notch provided to a side face of a containing space via a mirror in a state of the mirror is contained in the containing space of the lens holder. CONSTITUTION:A containing space 13a is provided to the rear side of a lens holder 13, a mirror 12 is contained therein and an incident light 19 from an optical system 21 is led to the mirror 12 through a notch 13b provided to one side of the containing space. Tracking coils 15, 15' and focusing coils 18, 18' are fitted exclusively to an outer wall of the lens holder 13 except the notch 13b of the containing space 13a. The lens holder is driven by energizing the coils and since the drive is attained while the mirror 12 is contained in the lens holder 13, the size H2 from the upper part of the lens holder 13 to the lower part of the optical system is considerably reduced. |
