Patent ID: 7630142

Claim:
A bent type zoom optical system comprising, in order from an object side thereof, a first lens group having positive refracting power, a second lens group having negative refracting power, an aperture stop, a reflecting mirror located on an image side with respect to the second lens group and adapted to bend an optical axis at substantially right angles upon taking operation, and a plurality of lens groups including a third lens group of positive refracting power and a fourth lens group of positive refracting power disposed between the reflecting mirror and an imaging plane, wherein for zooming, at least one lens group of the plurality of lens groups located on an imaging plane side with respect to the reflecting mirror moves with a varying spacing between the first lens group and the second lens group, characterized in that: the reflecting mirror remains fixed with respect to the imaging plane upon taking operation, and upon tucked away in a lens mount, the reflecting mirror has an angle varying such that a normal to a reflecting surface is substantially parallel with an optical axis through the first lens group and the second lens group, and the first lens group and the second lens group draw near to the reflecting mirror with a narrowing space therebetween.