A zoom lens including a broad picture angle of 60 to 100 degrees as a photographic picture angle of the wide-angle end state, and having a magnification ratio of about three to six times, small front gem diameter, excellent compactness and high image formation performance, which is used in a video camera or a digital still camera, and an image pick-up apparatus using such a zoom lens. A zoom lens (20), consisting of plural groups and serving to change group spacing or spacings to thereby perform a magnification changing or adjusting operation, comprises a first lens group GR1 having positive refractive power, a second lens group GR2 having negative refractive power and a third lens group GR3 having positive refractive power which are arranged in order from the object side, and a last group GRR arranged at the side closest to the image surface and having negative refractive power, wherein the first lens group GR1 is constituted by single positive lens G1, and satisfies the following conditional formulas. 0.540 (2) In the above formula, Ymax: maximum image height on image pick-up surface; FW: focal length at the wide-angle end state of the lens entire; and system VdG1: Abbe number at d line of the first lens group GR1.

 
Web www.patentalert.com

< Developing device and electrophotographic apparatus using the same

> Processing collocation mistakes in documents

> Case structure for card-type electronic product

~ 00574