BEAM SPLITTER AND OPTICAL PICKUP DEVICE EMPLOYING THE SAME

摘要

PURPOSE: A beam splitter and an optical pickup device employing the same are provided to realize the operation of a collimator lens by forming a reflection coating surface concavely and controlling the curvature of the concave reflection coating surface. CONSTITUTION: A beam splitter(110) form converting the path of light radiated from a light source and making the light parallel, includes a concave reflection coating surface(110a) at a side and a convex transmission coating surface(110b). The reflection coating surface is coated for reflecting incident light at a predetermined rate and formed of a concave surface to serve as a concave lens, so that the light emitted from the light source is reflected against the reflection coating surface toward an objective lens by the conversion of the light path and the conversion into parallel light. The convex transmission coating surface transmits the light condensed to a recording medium by the objective lens and reflected from the recording medium to a photo detector.