发明授权
US5483382A Projection lens and method of using same 失效
投影镜头及其使用方法

Projection lens and method of using same
摘要:
A new and improved projector lens arrangement which can automatically adjusted for focusing purposes in an easily and convenient manner according to a novel focusing method of the present invention. The projection lens arrangement generally includes three groups of optical elements aligned along a common optical axis with a variable vertex length and wide field coverage angle. One element group near the object is a doublet having a negative element with a concave surface and a positive element being bi-convex having one surface near the image complementarily shaped to the concave surface of the negative element.
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