| 摘要 |
The invention relates to a slimmed-down, small-format, high-zoom-ratio bent type zoom optical system that can be tucked away in a lens mount and an imaging system incorporating the same. The bent type zoom optical system or taking system comprises, in order from its object side, a first lens group G 1 of positive refracting power, a second lens group G 2 of negative refracting power and a reflecting mirror R located on an image side with respect to the second lens group G 2 for bending an optical axis at substantially right angles upon zooming. Between the reflecting mirror R and an imaging plane I there are a plurality of lens groups G 2 and G 4 interposed. For zooming, while the spacing between the first G 1 and the second lens group G 2 varies, at least one lens group of the plurality of lens groups G 2 and G 4 lying on the imaging plane side of the reflecting mirror R moves. The reflecting mirror R remains fixed with respect to the imaging plane I during taking operation, and upon tucked away in a lens amount, the angle of the reflecting mirror R varies such that the normal to the reflecting surface is substantially parallel with the optical axis through the first G 1 and the second lens group G 2 , and the first G 1 and the second lens group G 2 draw near to the reflecting mirror R with a narrowing spacing between them.
|
