| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact and inexpensive optical head device capable of compatibly reproducing plural optical disks of different kinds with one head device. SOLUTION: Light beams radiated from plural light sources 201, 202,..., 20n having different wavelengths are converted into luminous fluxes by a collimate lens 7 so as to be equal extension angles and made incident on a single mirror 11 having plural reflection surfaces having different curvature radiuses corresponding to the wavelengths of the light beams of the respective light sources. The respective reflection surfaces convert only the light beams of the corresponding light sources into luminous fluxes so as to be optimal extension angles with respect to an objective lens 9 and then fully reflect these. The reflected light beams are radiated to the recording surface of an optical disk 10 being a medium to be recorded and the existence of the information of respectively corresponding the optical disk is judged. |
