| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical head which is of a system to make incident parallel luminous fluxes and diverging luminous fluxes on a single objective lens and which facilitates and ensures the regulation of the positional relation between the second collimating lens of a diverging luminous flux system and a hologram module. SOLUTION: This optical head is separately provided with a first collimating lens for a first laser beam source and a second collimating lens for a second laser beam source. The second laser beam source, the second collimating lens and the objective lens are installed at a member movable in the radial direction of an optical disk. The first laser beam source and the first collimating lens are installed at a member which does move in the radial direction of the optical disk. The second collimating lens is made regulable in position within a plane perpendicular to the optical axis and the hologram module is made regulable in rotation in an θz direction around the optical axis. |
