Close-up attachment lens for a binocular
AssigneeAsahi Kogaku Kogyo Kabushiki Kaisha
InventorTetsuya Abe
Life of this patent
Estimating the term…
Abstract
A close-up attachment lens for a binocular includes a close-up lens group located on the object side of a pair of objective lenses of the binocular and is detachably attached to the binocular on the object side of the objective lenses. The close-up lens group is provided with a single optical system of positive power which covers the pair of objective lenses and has an optical axis parallel with and spaced from optical axes of the objective lenses at an equal distance. A pair of aperture stops are provided in front of the corresponding objective lenses of the binocular when the close-up attachment lens is attached to the binocular.
Claims18
A close-up attachment lens for a binocular, which is detachably attached on an object side of a pair of objective lenses of the binocular, said close-up attachment lens comprising:
- a close-up lens group comprising a single optical system of positive power, said close-up lens group being located on the object side of the pair of objective lenses of the binocular, so that the close-up lens group covers the pair of objective lenses and has an optical axis parallel with, and spaced from, optical axes of the objective lenses by an equal distance,
- a pair of aperture stops, said aperture stops being located in front of the corresponding objective lenses of the binocular when the close-up attachment lens is attached to the binocular;
- and
- a frame supporting said close-up lens group and said pair of aperture stops in fixed positions relative to each other,
- wherein a diameter of the aperture stops is set to smaller than an effective aperture of the objective lenses of the binocular.
Dependencies are inferred from the claim text.