发明授权
- 专利标题: Projection television apparatus
- 专利标题(中): 投影电视机
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申请号: US331471申请日: 1981-12-16
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公开(公告)号: US4453178A公开(公告)日: 1984-06-05
- 发明人: Yoshito Miyatake , Yoshitomi Nagaoka , Yasuo Nakajima
- 申请人: Yoshito Miyatake , Yoshitomi Nagaoka , Yasuo Nakajima
- 申请人地址: JPX Osaka
- 专利权人: Matsushita Electric Industrial Co., Ltd.
- 当前专利权人: Matsushita Electric Industrial Co., Ltd.
- 当前专利权人地址: JPX Osaka
- 优先权: JPX55-179460 19801217
- 主分类号: G02B9/60
- IPC分类号: G02B9/60 ; G02B13/16 ; G02B27/18 ; H04N9/31
摘要:
A projection television apparatus having a retrofocus type projection lens system which has a sufficiently long back focus, a small F number and a large distortion. The lens system is constructed with five components and five lenses and comprises a first lens which is a negative meniscus lens that has at its screen side a convex surface, a second lens which is a biconvex lens, a third lens which is a biconcave lens, a fourth lens which is a positive lens, and a fifth lens which is a biconvex lens, and which is defined by the following four conditions, i.e.1.4f
公开/授权文献
- US5606935A Holding tank system 公开/授权日:1997-03-04
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