| 摘要 |
PROBLEM TO BE SOLVED: To easily arrange a coupling lens in an optical pickup housing. SOLUTION: The coupling lens 14 is used for the optical pickup device which performs at least one of the recording, reproduction, and erasure of information on an optical recording medium 20 by converging the divergent luminous flux emitted by a semiconductor laser 10 into a spot on the recording surface 21 of the optical recording medium 20. This coupling lens is formed of one kind of material into a single body and has aspherical surfaces as both the surfaces and different positive focal lengths in mutually orthogonal directions crossing the optical axis at right angles; and the coupling lens is arranged in the optical pickup device so that the minor-axis direction of the elliptic intensity distribution of the luminous flux emitted by the semiconductor laser matches the direction of the longer focal length, and the lens peripheral surface part has at least one flat part 14A parallel to the optical axis. |
