Patent US3643573A successfully refreshed from Google Patents.
US3643573A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Eye-level eyepiece shielding device for eye-level and waist-level viewfinder
Assignee: Ricoh Co Ltd
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Filing: 1969-08-18
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Granted: 1972-02-22
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Expires: 1989-08-18
Abstract
Abstract An eye-level eyepiece shielding device for a camera in which a waist-level eyepiece is disposed upwardly of a final reflecting surface of a pentaroof-type reflecting mirror of a viewfinder optical system of a single-lens reflex camera, an eye-level eyepiece is disposed in the vicinity of a light exit of said pentaroof-type reflecting mirror, a planar reflecting mirror is disposed between the waist-level eyepiece and the final reflecting surface, and a shielding plate which can optionally shield and open the eye-level eyepiece is disposed forwardly of the eye-level eyepiece, the shielding plate being adapted to optically shield or open the eye-level eyepiece in response to the rotation of the planar reflecting mirror through a cam mechanism and a link mechanism so that when the waist-level eyepiece is used the external light through the eye-level eyepiece may be prevented from entering into the viewfinder optical system.
Inventors
- 👤 Kenji Hiruma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:44
CPC Classifications
G; G03; G03B; G03B19/00; G03B19/02; G03B19/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
497 words
A combined eye-level and waist-level viewfinder system in a single-lens reflex camera having a pentaroof-type reflecting mirror body wherein the waist-level eyepiece is positioned upwardly of a final reflecting surface of said body and the eyelevel eyepiece is positioned in the vicinity of the light exit of said body comprising a first shaft mounted in said camera; a planar reflecting mirror mounted on said shaft and pivotal between a retracted position preventing entering light to be reflected through said waist-level eyepiece and a reflecting position allowing entering light to be reflected through said waist-level eyepiece; a first lever having one end mounted on said first shaft, and a first pin mounted on the other end of said first shaft; a cam rotatably mounted in said camera, said cam having a low stepped portion, a middle stepped portion and a high stepped portion, said cam located and selectively positioned so that said first pin is in contact with one of said portions; a shielding plate mounted adjacent said eye-level eyepiece and pivotal to selectively shield said eye-level eyepiece from entering light; a second shaft mounted in said camera; a drive lever mounted to be selectively rotated on said second shaft, a second pin mounted on one end of said drive lever, said second pin positioned to be in contact with one of said portions of said cam that is different from another of said portions of said cam that is in contact with said first pin; a linkage interconnecting another end of said drive lever and said shielding plate; a photometric element mounted in said camera and pivotal between a first position wherein a specific area photometric value is viewed and a second position wherein an entire area photometric value is viewed, said photometric element connected to said linkage for its pivotal movement; said planar mirror pivotal into said reflecting position wherein said cam is positionable with said first pin in contact with said low stepped portion and said second pin is in contact with said high stepped portion whereby said drive lever positions said linkage and connected shielding plate to shield said eyelevel eyepiece and locate said photometric element in its first position; said planar mirror pivotal into said retracted position wherein said cam is positionable with said first pin in contact with said high stepped portion and said second pin is in contact with said middle stepped portion whereby said drive lever positions said linkage and connected shielding plate to allow entering light to pass through said eye-level eyepiece and locate said photometric element in its first position; and said planar mirror pivotal into said retracted position wherein said cam is positionable with said first pin in contact with said high stepped portion and said second pin is in contact with said low stepped portion whereby said drive lever positions said linkage and connected shielding plate to allow entering light to pass through said eye-level eyepiece and pivotally locate said photometric element in its second position.
Claim 2
Dependent Claim
497 words
A combined eye-level and waist-level viewfinder system in a single-lens reflex camera having a pentaroof-type reflecting mirror body wherein the waist-level eyepiece is positioned upwardly of a final reflecting surface of said body and the eyelevel eyepiece is positioned in the vicinity of the light exit of said body comprising a first shaft mounted in said camera; a planar reflecting mirror mounted on said shaft and pivotal between a retracted position preventing entering light to be reflected through said waist-level eyepiece and a reflecting position allowing entering light to be reflected through said waist-level eyepiece; a first lever having one end mounted on said first shaft, and a first pin mounted on the other end of said first shaft; a cam rotatably mounted in said camera, said cam having a low stepped portion, a middle stepped portion and a high stepped portion, said cam located and selectively positioned so that said first pin is in contact with one of said portions; a shielding plate mounted adjacent said eye-level eyepiece and pivotal to selectively shield said eye-level eyepiece from entering light; a second shaft mounted in said camera; a drive lever mounted to be selectively rotated on said second shaft, a second pin mounted on one end of said drive lever, said second pin positioned to be in contact with one of said portions of said cam that is different from another of said portions of said cam that is in contact with said first pin; a linkage interconnecting another end of said drive lever and said shielding plate; a photometric element mounted in said camera and pivotal between a first position wherein a specific area photometric value is viewed and a second position wherein an entire area photometric value is viewed, said photometric element connected to said linkage for its pivotal movement; said planar mirror pivotal into said reflecting position wherein said cam is positionable with said first pin in contact with said low stepped portion and said second pin is in contact with said high stepped portion whereby said drive lever positions said linkage and connected shielding plate to shield said eyelevel eyepiece and locate said photometric element in its first position; said planar mirror pivotal into said retracted position wherein said cam is positionable with said first pin in contact with said high stepped portion and said second pin is in contact with said middle stepped portion whereby said drive lever positions said linkage and connected shielding plate to allow entering light to pass through said eye-level eyepiece and locate said photometric element in its first position; and said planar mirror pivotal into said retracted position wherein said cam is positionable with said first pin in contact with said high stepped portion and said second pin is in contact with said low stepped portion whereby said drive lever positions said linkage and connected shielding plate to allow entering light to pass through said eye-level eyepiece and pivotally locate said photometric element in its second position.
Claim 3
Dependent Claim
54 words
A system according to claim 1 in which said drive lever includes three arms, said second pin is located at the end of one arm, and a second arm has an end shaped as a bifurcated slot, a third pin is associated with said linkage and positioned to be slidably engaged within said slot.
Claim 4
Dependent Claim
51 words
A system according to claim 2 in which said linkage includes a two-armed intermediate lever mounted to rotate in said camera, one end of saId intermediate lever is operatively associated with said third pin and its other end includes an operative connection to said photometric element to provide its pivotal movement.
Claim 5
Dependent Claim
60 words
A system according to claim 3 in which a first connecting lever is provided having one end connected to said other end of said intermediate lever and including a slotted area therein, a fourth pin is provided that is operatively connected with said shielding plate and mounted in said slotted area to provide the pivotal movement of said shielding plate.
Claim 6
Dependent Claim
41 words
A system according to claim 3 in which a second connecting lever is provided having one end connected to said other end of said intermediate lever and its other end provides the connection to said photometric element for the pivotal movement.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-21 | 1975-08-23 | 1976-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-21 | 1979-08-23 | 1980-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-21 | 1983-08-23 | 1984-02-22 | $7700.00 | Window Closed / Lapsed |