19-12-2016 дата публикации
Номер: KR1020160144847A
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According to an embodiment of the present invention, disclosed is a zoom-lens system which includes: a first lens group having negative refractive power; a second lens group having positive refractive power; and an aperture placed between the first and second lens groups. The first lens group, the second lens group, and the aperture are placed in order from an object to the upper surface. The zoom-lens system performs zooming by moving the second lens group in an optical axis direction, and performs focusing by moving the first lens group in the optical axis direction. The system satisfies the following conditional expressions at the same time. < expression 1> 2.5 < (fw/ft)×(Tw/Y) < 4.5. In the expression, fw is the whole focusing distance at a wide angle end, ft is the whole focusing distance at a telephoto end, Tw is a distance from a surface of the first lens group, the closest to the object, to the upper surface at the wide angle end, and Y is a paraxial height. COPYRIGHT KIPO 2016 ...
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