| 摘要 |
PROBLEM TO BE SOLVED: To provide a molded lens for achieving a small diameter of a lens face while making optical performance in the peripheral part of a lens effective region excellent even in the lens of a very small diameter. SOLUTION: Laser light output from a semiconductor laser light source 1 transmits a cover glass 2 in a Z direction of an optical axis, is incident on the molded lens 4 in the state of diverging light, and is made converging light by the molded lens 4 to irradiate a recording face 5 of a light recording medium. In addition, an aperture 3 is arranged, and a region on a lens face irradiated with a laser light flux restricted by the aperture 3 is the effective region of the lens face. When an effective diameter of the lens face being the diameter is d<SB>0</SB>, and an outside diameter of the lens face is d<SB>1</SB>, an inequality: d<SB>1</SB>-d<SB>0</SB>≥0.04 mm... (1) is satisfied. COPYRIGHT: (C)2008,JPO&INPIT
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