Patent ID: 6271964
Filing Date: 2001-08-07
Classification: G02B

Abstract:
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; anda 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.