Eyepiece lens
AssigneeOlympus Optical Co., Ltd.
InventorHideyasu Takato
Life of this patent
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Abstract
An eyepiece lens of the present invention and is arranged in a real image mode finder optical system consists essentially of a single positive meniscus lens convex on the object side having an object side surface and a pupil side surface, each of which is aspherical. This invention provides a compact eyepiece lens having a long optical path length from an image plane to the eyepiece lens, a large diameter of the exit pupil and a short focal length.
Claims11
An eyepiece lens for observing an image formed by an objective lens and correctly erected by a correctly erect image forming system, the eyepiece lens consisting essentially of a positive meniscus lens convex on the object side, wherein the positive meniscus lens has an object side surface and a pupil side surface, each of which is aspherical, and wherein the eyepiece lens is configured so as to satisfy the following condition (1):
- -1.times.10.sup.-3 <X.sub.1 /f<0 (1)
- where f is the focal length of the eyepiece lens, and X.sub.1 is the amount of displacement of the object side surface of the eyepiece lens from its reference sphere at a height of 0.12f from its optical axis, wherein the diameter .o slashed. of the exit pupil of the eyepiece lens satisfies the following condition:
- .o slashed..gtoreq.5 (mm).
An eyepiece lens for observing an image formed by an objective lens and correctly erected by a correctly erect image forming system, the eyepiece lens consisting essentially of a positive meniscus lens convex on the object side, wherein the positive meniscus lens has an object side surface and a pupil side surface, each of which is aspherical, and wherein the eyepiece lens system is configured so as to satisfy the following condition (2):
- 5<f/A<12 (2)
- where f is the focal length of the eyepiece lens, and A is the radius of the exit pupil of the eyepiece lens.
Dependencies are inferred from the claim text.