| 摘要 |
<p>A first lens group (G1) fixed relative to the image plane comprises a lens (11) having negative refractive power, a lens (12) having positive refractive power, and a lens (13) having positive refractive power. A second lens group (G2) has negative refractive power as a whole and is movable along the optical axis to bring about a magnifying action. The image plane is varied with the movement of the second lens group (G2) along the optical axis and of the object. The diaphragm is fixed relative to the image plane. A third lens group (G3) comprises a lens (31) having negative refractive power and a lens (32) having positive refractive power, has a positive or negative refractive power as a whole, and is fixed relative to the optical axis when the magnification is varied and the zooming lens is focused. A fourth lens group (G4) has positive refractive power as a whole and is movable along the optical axis so as to keep the image plane at a certain position. In such a way, a small, compact zooming lens bringing a high quality of image and preferable to 3CCD cameras is realized.</p> |
