OPTICAL PICKUP

摘要

PURPOSE:To use just a piece of a detection lens and to omit a lens barrel for reduction of cost by using a lens containing the spherical and cylindrical surfaces or the cylindrical surfaces having power meridians orthogonal to each other on both sides together with a positioning projection to a detecting optical system. CONSTITUTION:A detection lens 9 of a detecting optical system is made of glass or resin and contains the cylindrical and spherical surfaces or cylindrical surfaces having power meridians orthogonal to each other on both sides 9a and 9b. Furthermore a projection 9c for positioning of the revolving direction is provided at a part of the lens 9. Thus the function so far secured with two lenses can be attained with just a single lens. Thus the high reliability is obtained without producing an angle error of the power meridians nor a distance error between lenses. This can omit a lens barrel and reduces the cost of an optical pickup.