| 摘要 |
PURPOSE:To provide an optical pickup device which is capable of being easily miniaturized and is properly constituted so that the accurate position detection can be always performed. CONSTITUTION:The device is provided with a deflection type spherical lens 12 which has two aspherical surfaces 15a, 15b on the surface and at least one prism surface 16a at the inside and is supported with possilbe displacement in the tracking direction crossing at least a information track of the recording medium, an optical detector 14 which has at least two light receiving areas receiving the light of a luminous flux transmitting the prism surface 16a. A lumious flux 11 is made to enter a prism surface 16a from the tracking direction via one aspherical surface 15a of the lens 12, the luminous flux reflected at the prism surface 16a is made to exit from the other aspherical surface 15b roughtly in its normal direction and the luminous flux passing through the prism surface 16a is received by the optical detector 14. Based on the differential output of this optical detector 14, the position of the deflection type aspherical surface lens 12 in the tracking direction is detected. |
