Photography – Having camera indicator – Having display in viewfinder
Reexamination Certificate
2001-04-19
2003-03-11
Gray, David M. (Department: 2851)
Photography
Having camera indicator
Having display in viewfinder
C396S384000, C396S386000, C396S535000
Reexamination Certificate
active
06532344
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a camera, and specifically relates to a camera incorporating a real-image finder, having a structure more compact than ever.
A finder optical system, equipped besides a photographic lens system in a conventional lens shutter camera, etc., can be roughly classified into either a virtual-image finder optical system or a real-image finder optical system. As for the virtual-image finder optical system, however, there has been a problem that it becomes difficult to further minimize the dimensions of the camera, since the diameter of the front lens becomes excessively large when a high magnification capability is introduced into the camera. Therefore, there has been a tendency for a real-image finder optical system to be usually employed for small-sized cameras.
Incidentally, a real-image finder optical system can be further classified into either a type employing a roof mirror or a roof prism, or a type employing a combination of a prism and a flat mirror, a Porro prism or a mirror. A real-image finder optical system, employing a roof mirror or a roof prism, is characterized in that it is possible to position both an objective optical system and an ocular optical system on the same horizontal plane.
However, the following practical problems would tend to occur, when a real-image finder optical system, employing a roof mirror or a roof prism, is installed into a camera. At first, in case that a real-image finder optical system is disposed at such a position where interference with the film and magazine loaded on the camera is avoided, the lowest allowable position for the ocular optical system is determined by default. This fact causes the problem that, when the optical axis of the objective optical system is set on the same horizontal plane as that of the optical axis of the ocular optical system, the positional interval between the photographic lens system and the objective optical system of the finder optical system increases, resulting in enlargement of the parallax, corresponding to the amount of the positional interval.
Further, another problem is that accuracy of the objective optical system should be considerably improved, in order to suppress the total length of the real-image finder optical system, which employs a roof mirror or a roof prism, as shorter as possible.
On the other hand, although the abovementioned problems do not exist in the real-image finder optical system employing a flat mirror or a Porro prism, other problems caused by its structure have occurred. Concretely speaking, the real-image finder optical system of this type is characterized in that the optical axes of the objective optical system and the ocular optical system are shifted relative to each other in the vertical direction of the camera. This characteristic inherently makes the size of the finder unit large in the vertical direction of the camera, resulting in a trend of increased camera body size.
To cope with the abovementioned problem, in one type of conventional cameras, the size of camera body is minimized as compactly as possible by forming a protuberance only at the ocular optical system side of the camera. The camera of this type, however, cannot be shaped in a substantially rectangular parallelepiped, and it has, therefore, been a problem that the camera is inconvenient for storing, and allowances of designing the camera body are increasingly restricted.
Further, an illumination-type information-displaying member, which displays, for instance, the result of a ranging operation, is equipped in a camera to notify the photographer of information in regard to the image-capturing operation. In the above configuration, it is convenient for the photographer to display the information within the visual field of the finder, since the photographer can confirm such information while viewing the finder. It has been a difficult problem, however, to determine a suitable position for disposing the information-displaying member in such a camera, since the real-image finder optical system is a complicatedly shaped structure. Specifically, to display the information within the visual sight of the finder, the information-displaying member should be disposed in the optical path of the real-image finder optical system. For this purpose, a special space should be provided in the periphery of the finder section to arrange the information-displaying member at an appropriate position, resulting in large-sizing trend of the camera body.
SUMMARY OF THE INVENTION
To overcome the abovementioned drawbacks in conventional cameras, it is an object of the present invention to provide a camera, which is more compact than ever in spite of having a real-image finder optical system, and make it easier to view the information displayed in the finder.
Accordingly, to overcome the cited shortcomings, the abovementioned object of the present invention can be attained by cameras described as follow.
(1) A camera having a real-image finder, comprising: an objective optical system; an erect-image optical system, having a reflecting surface, to receive a light bundle passed through the objective optical system; and an ocular optical system to receive the light bundle reflected from the reflecting surface of the erect-image optical system; wherein a rear end of the reflecting surface is located at a backward position with respect to a film conveyance surface, and located outside the film conveyance surface, and, a front end of the reflecting surface is located at a forward position with respect to the film conveyance surface, and located inside the film conveyance surface.
(2) The camera of item 1, wherein the reflecting surface is disposed at such a position that the reflecting surface reflects the light bundle, received from the objective optical system, toward a direction of being apart from the film conveyance surface.
(3) A camera having a real-image finder, comprising: an objective optical system; an erect-image optical system, having a reflecting surface, to receive a light bundle passed through the objective optical system; and an ocular optical system to receive the light bundle reflected from the reflecting surface of the erect-image optical system; wherein a part of a film conveyance surface is arranged in a space between the reflecting surface and a body of the camera.
(4) A camera, comprising: a real-image finder including an objective optical system, an ocular optical system and an erect-image optical system; and an information-displaying member for displaying information within a visual field of the real-image finder, wherein, in case that a region, occupied by the objective optical system, the ocular optical system and the erect-image optical system, is projected onto a plane perpendicular to an optical axis of the objective optical system and is surrounded by an imaginary rectangular one side of which is an vertical direction of the camera, at least a part of the information-displaying member is disposed in a region to which neither the objective optical system, the ocular optical system nor the erect-image optical system belongs.
(5) The camera of item 4, wherein the information-displaying member is disposed at a side position of the objective optical system of the real-image finder.
(6) The camera of item 4, wherein the information-displaying member is disposed at a side position of the ocular optical system of the real-image finder.
(7) The camera of item 4, wherein the information-displaying member is disposed at a side position of the objective optical system of the real-image finder, and at a lower position of the ocular optical system of the real-image finder.
(8) The camera of item 4, wherein the information-displaying member includes a light emitting element, and a final reflecting surface of the erect-image optical system is a mirror, and a display-reflecting member, which emits an information-displaying light toward the mirror by reflecting the information-displaying light emitted from the light emitting element of the information-displaying mem
Nakayama Haruki
Ohtsuka Katsumi
Blackman Rochelle
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Gray David M.
Konica Corporation
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