Relay zoom system
AssigneeNikon Vision Co., Ltd.
InventorKenji Yamada
Life of this patent
Estimating the term…
Abstract
A relay zoom system includes, in order from an object side, a first lens group having a positive refractive power and a second lens group having a positive refractive power. Furthermore, in the relay zoom system, the first lens group and the second lens group are each made up of at least two positive lenses and one negative lens. The first lens group and the second lens group in the relay zoom system are configured so as to move along an optical axis when magnification is varied from a lower magnification edge state to a higher magnification edge state.
Claims11
A relay zoom system comprising, in order from an object side:
- a first lens group having a positive refractive power;
- and
- a second lens group having a positive refractive power, wherein
- the first lens group and the second lens group are each made up of at least two positive lenses and one negative lens,
- the first lens group and the second lens group move along an optical axis when magnification is varied from a lower magnification edge state to a higher magnification edge state,
- the first lens group includes:
- a cemented lens which cements together one of the positive lenses and the negative lens, and
- a single positive lens, and
- if fl1 denotes a focal length of the cemented lens and fl2 denotes a focal length of the single positive lens, then the relay zoom system satisfies a condition expressed by an expression below:
- 1<fl1/fl2<2.
A relay zoom system comprising, in order from an object side:
- a first lens group having a positive refractive power;
- and
- a second lens group having a positive refractive power, wherein
- the first lens group and the second lens group are each made up of at least two positive lenses and one negative lens,
- the first lens group and the second lens group move along an optical axis when magnification is varied from a lower magnification edge state to a higher magnification edge state, and
- the first lens group moves towards either an object side or an image side from the lower magnification edge state to a predetermined focal length state and moves in the opposite direction from the predetermined focal length state to the higher magnification edge state.
Dependencies are inferred from the claim text.