发明授权
- 专利标题: Projection lens system
- 专利标题(中): 投影镜头系统
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申请号: US188482申请日: 1988-04-29
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公开(公告)号: US4948237A公开(公告)日: 1990-08-14
- 发明人: Koji Hirata , Kyohei Fukuda , Hiroki Yoshikawa , Shigeru Mori , Masayuki Muranaka , Isao Yoshizaki , Shigeru Inaoka , Hiroshi Jitsukata
- 申请人: Koji Hirata , Kyohei Fukuda , Hiroki Yoshikawa , Shigeru Mori , Masayuki Muranaka , Isao Yoshizaki , Shigeru Inaoka , Hiroshi Jitsukata
- 申请人地址: JPX Tokyo
- 专利权人: Hitachi, Ltd.
- 当前专利权人: Hitachi, Ltd.
- 当前专利权人地址: JPX Tokyo
- 优先权: JPX62-309604 19871209; JPX63-85070 19880408
- 主分类号: G02B13/16
- IPC分类号: G02B13/16 ; G02B9/34 ; G02B13/18
摘要:
In a projection system wherein an optical system comprising a first lens for correcting a spherical aberration dependent on the aperture length, a second lens for enlargement and a third lens for correcting a field curvature, projects an image reproduced on a CRT having a curved phosphor surface, onto a screen, the third lens is spaced from the CRT so that the region of the phosphor surface which again totally reflects a light which has been totally reflected by a screen-side surface of the third lens is limited to the edge portion of an effective region of the phosphor surface.
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