| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a variable magnification optical system, which can be manufactured at low cost while having a configuration having a small size and a large aperture ratio, and can maintain good optical performances. Ž<P>SOLUTION: The variable magnification optical system includes, in order from an object side, a first lens group G1 having negative refractive power, a diaphragm, and a second lens group G2 having positive refractive power. The optical system performs magnification change by changing the space between the first lens group G1 and the second lens group G2 on an optical axis Z, and performs correction of image plane position associated with the magnification change by moving the first lens group G1 along the optical axis. The first lens group G1 includes, in order from the object side, two negative lenses and a positive lens. The second lens group G2 has a four-lens structure composed of, in order from the object side, two positive lenses, a negative lens and a positive lens. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
