发明名称 |
Projektionskopf fuer Staenderprojektoren |
摘要 |
1,258,519. Overhead projector head; diaphragms. MINNESOTA MINING & MFG. CO. March 3, 1969 (March 4, 1968], No.11186/69. Headings G2A and G2J. An overhead projector head of the kind having two meniscus lenses 12, 14 at right-angles and a plane mirror 13 at the hypotenuse has in addition an apertured screen 15 at right-angles to the mirror 13 to reduce spurious reflections within the head. The aperture is semi-elliptical in shape and is positioned so that-substantially the entire beam passing through lens 12 falls on to the mirror 13. The screen 15 may also be used in projection heads without the second meniscus lens 14. |
申请公布号 |
DE1909641(A1) |
申请公布日期 |
1969.10.02 |
申请号 |
DE19691909641 |
申请日期 |
1969.02.21 |
申请人 |
MINNESOTA MINING AND MANUFACTURING COMPANY |
发明人 |
HARRY ANDERSON,RAYMOND;HENRY APPELDORN,ROGER |
分类号 |
G02B17/00;G02B27/18;G03B21/132 |
主分类号 |
G02B17/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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