Inner focus type telescope
First Claim
1. A telescope comprising:
- a sighting objective lens, a focusing lens, a horizon compensating optical system, and a focal plane on which an object image is formed by said sighting objective lens and said focusing lens, arranged in this order from an object side, said horizon compensating optical system comprises a first compensating prism, a compensating mirror, and a second compensating prism;
a position of said focusing lens being adjustable to form the object image on the focal plane in accordance with a distance of an object to be sighted;
a beam splitting optical system provided in an optical path between said horizon compensating optical system and the focal plane to split the optical path of light incident on the beam splitting optical system, said beam splitting optical system comprises a beam splitting element which is adhered to the light emission surface of the second compensating prism;
a surface optically equivalent to the focal plane, provided in said beam splitting optical path;
a correcting system that corrects an optical positional deviation between the focal plane and the optically equivalent surface; and
a focus detecting system which detects the state of focus at the optically equivalent surface, said focus detecting system comprising a pair of reimaging lenses spaced at a base length distance, and a pair of line sensors in which object images are formed by said reimaging lenses, one of said line sensors being provided with a first reference area to obtain a first reference output, and the other line sensor being provided with a second reference area to obtain a second reference output, so that a deviation of the light conversion point of the sighting optical system, comprising said sighting objective lens and said focusing lens, from the optically equivalent surface, can be detected by a phase difference detection method, based upon said reference outputs.
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Accused Products
Abstract
An inner focus type telescope includes a sighting objective lens, a focusing lens, a horizon compensating optical system, a focal plane, and an eyepiece through which an object image formed on the focal plane can be viewed, arranged in this order from the object side. The position of the focusing lens is adjustable to form the object image on the focal plane in accordance with the distance of an object to be viewed. The telescope further includes a beam splitting optical system provided in the optical path between the objective lens and the focal plane to split the optical path, a surface equivalent to the focal plane, provided in the beam splitting optical system, and a focus detecting system which detects the state of the focus at the equivalent surface.
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Citations
25 Claims
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1. A telescope comprising:
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a sighting objective lens, a focusing lens, a horizon compensating optical system, and a focal plane on which an object image is formed by said sighting objective lens and said focusing lens, arranged in this order from an object side, said horizon compensating optical system comprises a first compensating prism, a compensating mirror, and a second compensating prism; a position of said focusing lens being adjustable to form the object image on the focal plane in accordance with a distance of an object to be sighted; a beam splitting optical system provided in an optical path between said horizon compensating optical system and the focal plane to split the optical path of light incident on the beam splitting optical system, said beam splitting optical system comprises a beam splitting element which is adhered to the light emission surface of the second compensating prism; a surface optically equivalent to the focal plane, provided in said beam splitting optical path; a correcting system that corrects an optical positional deviation between the focal plane and the optically equivalent surface; and a focus detecting system which detects the state of focus at the optically equivalent surface, said focus detecting system comprising a pair of reimaging lenses spaced at a base length distance, and a pair of line sensors in which object images are formed by said reimaging lenses, one of said line sensors being provided with a first reference area to obtain a first reference output, and the other line sensor being provided with a second reference area to obtain a second reference output, so that a deviation of the light conversion point of the sighting optical system, comprising said sighting objective lens and said focusing lens, from the optically equivalent surface, can be detected by a phase difference detection method, based upon said reference outputs. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A telescope comprising:
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a sighting objective lens, a focusing lens, a horizon compensating optical system, and a focal plane on which an object image is formed by said sighting objective lens and said focusing lens, arranged in this order from an object side; a position of said focusing lens being adjustable to form the object image on the focal plane in accordance with a distance of an object to be sighted; a beam splitting optical system provided in an optical path between said sighting objective lens and the focal plane to split the optical path; a surface optically equivalent to the focal plane, provided in said beam splitting optical path; a correcting system that corrects an optical positional deviation between the focal plane and the optically equivalent surface, said correcting system comprising a movement adjusting system that moves the focus detecting system relative to the optically equivalent surface; a focus detecting system which detects the state of focus at the optically equivalent surface, said focus detecting system comprising a pair of reimaging lenses spaced at a base length distance, and a pair of line sensors in which object images are formed by said reimaging lenses, one of said line sensors being provided with a first reference area to obtain a first reference output, and the other line sensor being provided with a second reference area to obtain a second reference output, so that a deviation of the light conversion point of the sighting optical system, comprising said sighting objective lens and said focusing lens, from the optically equivalent surface, can be detected by a phase difference detection method, based upon said reference outputs; and a battery box in which a battery is received in a liquid-tight fashion, said battery box including an operating portion that operates said correcting system, said operating portion provided with a manually actuatable operation knob, and a dial which is positioned about the operation knob, said dial indicating successive displacements of the focus detecting system depending on an external condition including moisture, upon measurement. - View Dependent Claims (10, 11, 12, 13)
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14. A telescope comprising:
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a sighting objective lens, a focusing lens, a horizon compensating optical system, and a focal plane on which an object image is formed by said sighting objective lens and said focusing lens, arranged in this order from an object side, a position of said focusing lens being adjustable to form said object image on said focal plane in accordance with a distance of an object to be sighted; a beam splitter, provided in an optical path between said sighting objective lens and said focal plane, for reflecting part of a beam of light incident on said beam splitter while transmitting a remaining part of said beam of light; a surface optically equivalent to said focal plane, provided in a path of said reflected part of said beam of light; a focus detecting system for detecting the state of focus at said optically equivalent surface, said focus detecting system comprising a pair of reimaging lenses spaced at a base length distance, and a pair of line sensors in which object images are formed by said reimaging lenses, one of said line sensors being provided with a first reference area to obtain a first reference output, and the other line sensor being provided with a second reference area to obtain a second reference output, so that a deviation of the light conversion point of a sighting optical system, comprising said sighting objective lens and said focusing lens, from said optically equivalent surface, can be detected by a phase-difference detection method, based upon said reference outputs; and a correcting system for correcting an optical positional deviation between said focal plane and said optically equivalent surface, said correcting system comprising a system that eliminates a variation in said deviation which occurs due to a variation in at least one of temperature and humidity. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A telescope comprising:
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a sighting objective lens, a focusing lens, a horizon compensating optical system, and a focal plane on which an object image is formed by said sighting objective lens and said focusing lens, arranged in this order from an object side; a position of said focusing lens being adjustable to form the object image on the focal plane in accordance with a distance of an object to be sighted; a beam splitting optical system provided in an optical path between said sighting objective lens and the focal plane to split the optical path of light incident on the beam splitting optical system; a surface optically equivalent to the focal plane, provided in said beam splitting optical path; a correcting system that corrects an optical positional deviation between the focal plane and the optically equivalent surface, said correcting system selects a group of light receiving elements which define said second reference area from a large number of light receiving elements comprising one of said pair of line sensors, said group comprising less than all of said light receiving elements, while fixing a group of light receiving elements which define said first reference area selected from among a large number of light receiving elements comprising the other of said pair of line sensors, to thereby vary the center of said second reference area; a focus detecting system which detects the state of focus at the optically equivalent surface, said focus detecting system comprising a pair of reimaging lenses spaced at a base length distance, and a pair of line sensors in which object images are formed by said reimaging lenses, one of said line sensors being provided with a first reference area to obtain a first reference output, and the other line sensor being provided with a second reference area to obtain a second reference output, so that a deviation of the light conversion point of the sighting optical system, comprising said sighting objective lens and said focusing lens, from the optically equivalent surface, can be detected by a phase difference detection method, based upon said reference outputs; and
a battery box in which a battery is received in a liquid-tight fashion, said battery box including an operating portion thatactuates the correcting system.
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Specification