发明授权
US5694244A Real-image finder having variable power 失效
具有可变功率的实像取景器

Real-image finder having variable power
摘要:
A real-image finder having variable power includes an objective lens system of positive power, a condenser lens, and an ocular lens system. The objective lens system includes a first positive lens group, a second negative lens group, and a third positive lens group from an object side towards an image side. The second lens group is moved toward an image side and the third lens group is moved toward an object side, when the magnification changes from a wide angle side to a telephoto side. Thus, the distance between the first and second lens groups increases, the distance between the second and third lens groups decreases, and the distance between the third lens group and the condenser lens increases. The real-image finder meets the requirements defined by the relationships 0.5
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