| 摘要 |
PURPOSE: To provide an optical system for generating a position error for minimizing the conversion error of data recorded on an optical medium. CONSTITUTION: This is concerned to a method and device for generating a position error signal from a light beam called as an input light beam 42 to be reflected from the optical surface of a storage medium and is provided with a prism 44 for generating first and second complementary light beams 46, 48 by receiving the input light beam 42. First and second photodetectors 50, 52 are respectively arranged at positions respectively receiving the complementary light beams to generate first and second electric detector signals indicating incident lights an respective detectors The position error signal is generated according to the first and second detector signals. The prism 44 is provided with a reflection/transmission boundary 60. The input light beam 42 is made incident on the boundary at the angle of not larger than a critical angle so as to be reflectable/transmitable. |
