| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an objective optical system for an optical pickup apparatus that can suppress occurrence of a ghost and can secure a working distance while temperature characteristics are improved and to provide the optical pickup apparatus using the same. <P>SOLUTION: The objective optical system for the optical pickup apparatus is constituted of a first lens and a second lens made of plastic. Each lens has a refractive power. Thereby the curvature of each optical surface is relaxed to improve temperature characteristics. Since the refractive power P1 of the first lens and the power P of the whole system of the first and the second lenses satisfy the predetermined condition, the refractive power of the first lens is not made too high and an improvement effect of the temperature characteristics and securing of the working distance can be attained. Since opposite optical surfaces of the first lens are convex surfaces, adverse influence on a detector by reflection light can be suppressed. <P>COPYRIGHT: (C)2007,JPO&INPIT |
