发明名称 Zoom lens and projector unit
摘要 To provide a compact, high-performance zoom lens having a small lens aperture for enlarging an image from a light valve such as a DMD for forming an image by changing a reflecting direction of light and projecting the image so enlarged on to a screen or the like, and a zoom lens so provided includes, in order from a magnifying side, a first lens group having a negative refractive power as a whole, a second lens group having a positive refractive power as a whole, and a third lens group having a positive refractive power as a whole, wherein changing the magnification of a whole lens system thereof is attained by configuring such that while a magnification varying operation is in effect, the third lens group is left fixed, the first lens group and the second lens group are made to move on the optical axis.
申请公布号 US7545581(B2) 申请公布日期 2009.06.09
申请号 US20070879693 申请日期 2007.07.17
申请人 CASIO COMPUTER CO., LTD. 发明人 KAWAKAMI ETSURO;TEJIMA YASUYUKI
分类号 G02B15/14 主分类号 G02B15/14
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