Patent ID: 6075654
Filing Date: 2000-06-13
Classification: G02B

Abstract:
A three-group zoom lens comprising, in order from the object side:a first lens group of positive refractive power;a diaphragm positioned nearest the imaging surface side of said first lens group;a second lens group of positive refractive power; anda third lens group of negative refractive power;whereinwhen power is varied by shifting from the wide-angle end to the telephoto end, the first lens group and the third lens group are shifted as one body, the spacing between the first lens group and the second lens group is increased and the spacing between the second lens group and the third lens group is decreased, andthe second lens group comprises, in order from the object side: a meniscus lens element of negative refractive power with its concave surface on the object side, a positive lens element that is biconvex, a lens element of negative refractive power, and a lens element of positive refractive power.