| 摘要 |
<p>PURPOSE:To offer a variable power optical system having a vibration proof function of a simple constitution by providing a first group having a focusing function and a variable power group in order from an object side, and moving a part of lens group in its first group substantially in the vertical direction against an optical axis. CONSTITUTION:The title system is provided with a first group I having a focusing function, a second group II for variable power, a third group III for correcting an image face which is fluctuated by following up variable power, a fourth group IV and a fifth group V for an image formation in order from an object side, and a variable power group P is constituted of the second group II and the third group III. The first group I consists of a vibration proof use lens group Ia which can move in the vertical direction to an optical axis and a focusing use lens group Ib which can move in the optical axis direction, and by moving the lens group Ia substantially in the vertical direction to the optical axis and supplying the correction quantity of the same quantity to the same inclination quantity against vibration, etc. of a variable power optical system, a vibration proofing effect is obtained. In such a way, the variable power optical system of a simple constitution which is evaded a structural complication when the first group I is allowed to have a focusing function and a vibration proofing function can be offered.</p> |
