| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a compact lens for a projector. <P>SOLUTION: The lens system 10 for projecting projection light to a screen 6 comprises, in order from a side of the screen 6: a first lens L11 of a meniscus type, which is convex on the side of the screen 6, having negative refractive power; a second lens L12 of a meniscus type, which is concave on the side of the screen 6, having positive refractive power; a third lens L13 and a fourth lens L14. Furthermore, an effective diameter of a concave surface S6 of the third lens L13 is larger than an effective diameter of a concave surface S3 of the second lens L12, and an effective diameter of a concave surface S8 of the fourth lens L14 is larger than the effective diameter of the concave surface S6 of the third lens L13. Then, a part of a convex surface S7 of the third lens L13 and a part of the concave surface S8 of the fourth lens L14 are in common space along an optical axis. <P>COPYRIGHT: (C)2010,JPO&INPIT |
