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US 2019/0170997 A1Published application
Binoculars and ocular lens
AssigneeNikon Vision Co., Ltd.
InventorsSatoshi FUKUMOTO, Katsunori TOMITA, Tatsushi NISHIOKA
Life of this patent
Estimating the term…
Abstract
Binoculars and an ocular lens have an excellent optical performance. Binoculars include: a first lens-barrel and a second lens-barrel having an objective lens and an ocular lens; and an Abbe-Koenig prism which is an erecting optical element included in the first lens-barrel and the second lens-barrel, and is characterized in that the product of an effective diameter (mm) of the objective lens and the real field of view (°) is 450 mm° or larger.
Claims22
Binoculars comprising:
- a first lens-barrel and a second lens-barrel having an objective lens and an ocular lens;
- and
- an Abbe-Koenig prism as an erecting optical element included in the first lens-barrel and the second lens-barrel, wherein
- a product of an effective diameter (mm) and a real field of view (°) of the objective lens is 450 mm° or larger.
1 more element
An ocular lens comprising:
- from the object side in this order,
- a first lens group having negative refracting power;
- and
- a second lens group having positive refracting power, wherein:
- an object-side focal plane of the second lens group is positioned between the first lens group and the second lens group;
- the first lens group includes, from the object side in this order,
- a meniscus first A lens component whose convex surface is directed toward the object side, and
- a first B lens component having negative refracting power;
- the second lens group includes, in a position closest to the object side, a meniscus second A lens component whose concave surface is directed toward the object side;
- and
- satisfies the condition of the following expression:
- 1.8≤(−f1)/f≤6.0
- 0.5≤D/f≤2.0
- where
- f is the entire focal length of the ocular lens,
- f1 is a focal length of the first lens group, and
- D is an air space between the first lens group and the second lens group.
14 more elements
Dependencies are inferred from the claim text.