发明名称 | Variable magnification optical system for projection and projection-type display apparatus | ||
摘要 | A variable magnification optical system for projection consists of a negative lens group and a positive lens group in this order from a magnification side. A distance on an optical axis between the negative lens group and the positive lens group changes during magnification change, and an entire system substantially consists of six lenses. The negative lens group consists of a first lens including an aspheric surface and a second lens that is a negative single lens in this order from the magnification side. | ||
申请公布号 | US9261687(B2) | 申请公布日期 | 2016.02.16 |
申请号 | US201414556530 | 申请日期 | 2014.12.01 |
申请人 | FUJIFILM Corporation | 发明人 | Nagatoshi Yukiko |
分类号 | G02B15/14;G02B15/177;G02B13/18;G02B15/16;G02B15/20;G02B13/16 | 主分类号 | G02B15/14 |
代理机构 | Young & Thompson | 代理人 | Young & Thompson |
主权项 | 1. A variable magnification optical system for projection consisting of: a negative lens group having negative refractive power; and a positive lens group having positive refractive power in this order from a magnification side, wherein a distance on an optical axis between the negative lens group and the positive lens group changes during magnification change, and wherein an entire system substantially consists of six lenses, and wherein the negative lens group consists of a first lens including an aspheric surface and a second lens that is a single lens having negative refractive power in this order from the magnification side, and wherein the first lens is made of plastic material, and wherein the following conditional expression (1) is satisfied: |fw/f1|<0.1 (1), where fw: a focal length of the entire system at a wide angle end, and f1: a focal length of the first lens. | ||
地址 | Tokyo JP |