LENS AND OPTICAL PICK-UP EMPLOYING THE SAME

摘要

PURPOSE: A lens and an optical pick-up employing the lens are provided to reduce the mechanical height of an optical system. CONSTITUTION: A lens is composed of an effective lens region that affects the transmission of light and a region surrounding the effective lens region. At least a part of the outer side of the surrounding region is plane. The surrounding region has one of tetragon, pentagon and hexagon. An optical pick-up records information on a recording medium and/or reproduces information recorded on the recording medium, and condenses light emitted from a light source(12) on an objective lens(17) to irradiate the condensed light on the recording medium. The optical pick-up includes a collimating lens(13) that converts lights that are emitted from the light source and travel toward the objective lens to parallel light. The collimating lens is composed of an effective lens region that affects the transmission of lights and a region surrounding the effective lens region.