Optical: systems and elements – Compound lens system – Telescope
Reexamination Certificate
2000-03-31
2001-08-28
Spyrou, Cassandra (Department: 2872)
Optical: systems and elements
Compound lens system
Telescope
C359S407000, C359S433000, C359S473000
Reexamination Certificate
active
06282021
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a viewing optical instrument (such as a telescope, a monocular, binocular or field glasses) in which the eyepiece can be brought into focus entirely on a plane which is not normal to the optical axis of the objective optical system.
2. Description of the Related Art
In conventional viewing optical instruments such as telescopes, monoculars, binoculars or field glasses, the eyepiece can be brought into focus entirely on a plane normal to the optical axis of the objective optical system but cannot be brought into focus entirely on a plane other than the normal plane, e.g., a side surface of an object having a wide length which extends at an angle relative to a plane normal to the optical axis of the viewing optical instrument. In such conventional viewing optical instruments, particularly within a short distance range, the eyepiece can be brought into focus only on a small part of a surface if the surface extends at a large angle relative to a plane normal to the optical axis of the objective optical system of the viewing optical instrument, so that the focal point needs to be re-adjusted many times if the user desires to observe the entire large-angled surface. For instance, when the user looks at a wide blackboard with a conventional viewing optical instrument from the right or left front corner in a large auditorium, or when the user monitors a wall in a large square room from any of the four corners of the room, the in-focus area in the field of view will be narrow, which is quite inconvenient.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a viewing optical instrument in which the eyepiece can be swung or tilted to bring the eyepiece into focus entirely on a plane which is not normal to the optical axis of the objective optical system of the viewing optical instrument.
To achieve the object mentioned above, according to an aspect of the present invention, a viewing optical instrument is provided which has an objective optical system and an eyepiece optical system, and an object image formed through the objective optical system is magnified and observed through the eyepiece optical system. The viewing optical instrument includes an eyepiece adjusting device which allows the eyepiece optical system to rotate relative to the objective optical system about a rotational axis at which an optical axis of the objective optical system intersects a focal plane formed by the objective optical system. The viewing instrument which includes a detector detects an inclination of a surface of a sighting object relative to a plane which is normal to the optical axis of the objective optical system, and a controller controls the eyepiece optical system to rotate about the rotational axis in accordance with the inclination detected by the detector.
According to a feature of the present invention, the detector preferably includes at least three AF sensors which respectively correspond to at least three focus detection zones defined in a field of view seen through the eyepiece optical system.
According to a further feature of the present invention, the detector preferably includes at least four AF sensors which respectively correspond to at least four focus detection zones defined in a field of view seen through the eyepiece optical system. The detector detects the inclination in accordance with signals output from three of the at least four AP sensors which respectively correspond to three of the at least four focus detection zones, the three focus detection zones being optionally selected from the at least four focus detection zones.
Preferably, the controller controls the eyepiece optical system to rotate about the rotational axis according to the Scheimpflug principle so that an optical axis of the eyepiece optical system is normal to an image plane, which is inclined relative to a plane which is normal to the optical axis of the objective optical system.
Preferably, according to a feature of the present invention, the viewing optical instrument further includes a tubular body which accommodates the objective optical system therein, an eyepiece holder which accommodates the eyepiece optical system therein, and a mount connected to a rear end of the tubular body to be positioned between the tubular body and the eyepiece holder so that an axis (center) of the mount is coincident with an optical axis of the eyepiece optical system. The mount includes a concave face at the rear end thereof. The eyepiece holder is connected to the concave face of the mount so that the eyepiece holder can be swung or tilted relative to the tubular body.
Preferably, the eyepiece holder includes a spherical surface at a front end of the eyepiece holder, the spherical surface being connected to the concave face of the mount.
Preferably, the viewing optical instrument further includes an erecting optical system positioned between the objective optical system and the eyepiece optical system.
Preferably, the viewing optical instrument is a binocular.
According to another aspect of the present invention, a viewing optical instrument is provided which has an objective optical system and an eyepiece optical system. An object image formed through the objective optical system is magnified and observed through the eyepiece optical system. The viewing optical instrument includes a diffusion plate on which the object image is formed, and an eyepiece adjusting device which allows the eyepiece optical system and the diffusion plate to rotate as a unit relative to the objective optical system about a rotational axis at which the optical axis of the objective optical system intersects a matte surface of the diffusion plate.
Preferably, the center of the diffusion plate lies on both the optical axis of the objective optical system and on the optical axis of the eyepiece optical system.
Preferably, the eyepiece optical system and the diffusion plate can be moved in a direction of the optical axis of the objective optical system.
Preferably, the viewing optical instrument further includes a controller for controlling the eyepiece optical system to rotate about the rotational axis, so that an optical axis of the eyepiece optical system is normal to the image plane which is inclined, according to the Scheimpflug principle, relative to a plane which is normal to the optical axis of the objective optical system.
Preferably, the viewing optical instrument further includes a tubular body which accommodates the objective optical system therein and eyepiece holder which accommodates the eyepiece optical system therein. A mount is connected to a rear end of the tubular body to be positioned between the tubular body and the eyepiece holder so that an axis of the mount is coincident with an optical axis of the eyepiece optical system. The mount includes a concave face at the rear end thereof. The eyepiece holder is connected to the concave face of the mount so that the eyepiece holder can be swung or tilted relative to the tubular body.
Preferably, the eyepiece holder includes a spherical surface at a front end of the eyepiece holder, the spherical surface being connected to the concave face of the mount.
Preferably, the viewing optical instrument further includes an erecting optical system positioned between the objective optical system and the eyepiece optical system.
Preferably, the viewing optical instrument is a binocular.
The present disclosure relates to subject matter contained in Japanese Patent Applications Nos. 11-96373 and 11-96374 (both filed on Apr. 2, 1999) which are expressly incorporated herein by reference their entireties.
REFERENCES:
patent: 4877318 (1989-10-01), Miles et al.
patent: 5073017 (1991-12-01), Suda
patent: 5592331 (1997-01-01), Eastcott
patent: 5764408 (1998-06-01), Otaki
Asahi Kogaku Kogyo Kabushiki Kaisha
Greenblum & Bernstein P.L.C.
Spyrou Cassandra
Treas Jared
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