发明名称 |
Projection lens |
摘要 |
An object of the present invention is to suppress an influence due to temperature change and various aberrations. It is a projection lens which projects an image on a surface of a screen (magnified side). A first group I having a negative refractive power and a second group II having a positive refractive power are arranged in order from a magnified side toward a reduced side. The first group I is configured to arrange a first lens and a second lens in order from the magnified side, and the second group II is configured to arrange a third lens to a seventh lens. The first and second lenses are a negative meniscus lens whose both surfaces are formed by the aspherical surface in which an area near an optical axis of the surface on the magnified side is a concave surface. The third lens is a cemented lens in which a bi-concave lens is cemented to the surface on the reduced side of a bi-convex lens. The fourth lens is a positive meniscus lens whose both surfaces are formed by the aspherical surface, and a convex surface of the positive meniscus lens faces toward the reduced side. The fifth lens is the cemented lens in which the bi-concave lens is cemented to the surface on the reduced side of the bi-convex lens. The sixth lens is a positive lens whose strong convex surface faces toward the reduced side. The seventh lens is the positive lens whose both surfaces are a convex surface.
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申请公布号 |
US2005122598(A1) |
申请公布日期 |
2005.06.09 |
申请号 |
US20040995034 |
申请日期 |
2004.11.23 |
申请人 |
KOBAYASHI TAKESHI;SEKINE KUMAJIRO |
发明人 |
KOBAYASHI TAKESHI;SEKINE KUMAJIRO |
分类号 |
G02B13/04;G02B13/16;G02B13/18;G02B13/22;H04N5/74;(IPC1-7):G02B9/00;G02B27/10 |
主分类号 |
G02B13/04 |
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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