| 摘要 |
PURPOSE: A miniature zoom lens is provided to have telecentric property adequate to a solid camera element such as CCD or CMOS by having a simple structure and a small size, having magnification transformation ratio of two times or three times. CONSTITUTION: A miniature zoom lens includes a first lens group(i), a second lens group(ii), a third lens group(iii) and a forth lens group(iv) positioned in regular order from an object. The first lens group(i) has a negative refractivity. The second lens group(ii) has a positive refractivity. The third lens group(iii) has a negative refractivity. The forth lens group(iv) has a positive refractivity. A tightening tread is positioned between the first lens group(i) and the second lens group(ii). The first lens group(i) has at least one lens having a negative refractivity or a positive refractivity. The second lens group(ii) includes at least one sheet of cemented lens and at least one sheet of aspheric lens. The third lens group(iii) includes a seventh lens group. The seventh lens group(ii) is a meniscus lens. Both surfaces of the seventh lens group are convex.
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