Patent US4274720A successfully refreshed from Google Patents.
US4274720A
Expired / Lapsed
US
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Automatic focus control device for objective lens exchangeable cameras
Assignee: Minolta Co Ltd
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Filing: 1979-04-20
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Granted: 1981-06-23
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Expires: 1999-04-20
Abstract
Abstract In an automatic focusing system for a camera having an exchangeable lens, the camera body includes a control mechanism for controlling the focus of the exchangeable lens in accordance with an output of a photoelectric focus or distance detecting element. The control mechanism is interlocked by an intermediate elongated member with a lens displacing mechanism in the exchangeable lens, with the intermediate member extending within an aperture of the lens mount. The exchangeable lens may be of the type wherein a rear lens group is moveable for focusing.
Inventors
- 👤 Kayoshi Tsujimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:58
CPC Classifications
G; G03; G03B; G03B3/00; G03B3/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
181 words
An automatic focusing system for an objective lens exchangeable camera, comprising: an exchangeable lens having a lens group movable for focusing the lens; a fixed member with a mount for mounting said exchangeable lens on said camera, and a lens drive member movable relative to said fixed member for driving said lens group along the optical axis thereof, said mount including an aperture; a camera body including a movable member movable to any position corresponding to any position of said movable lens group, and means for determining the position of said movable member;/an intermediate member for interconnecting said movable member and said lens drive member upon coupling of said exchangeable lens with said camera body such that the position of said movable member determines the position of said movable lens group, said intermediate member being included in said exchangeable lens and extending through said aperture of said lens mount, said movable member including an abutting member abutting with said intermediate member from one direction to form one-directional engagement therewith; and biasing means for abutting said intermediate member and said abutting member.
Claim 2
Dependent Claim
181 words
An automatic focusing system for an objective lens exchangeable camera, comprising: an exchangeable lens having a lens group movable for focusing the lens; a fixed member with a mount for mounting said exchangeable lens on said camera, and a lens drive member movable relative to said fixed member for driving said lens group along the optical axis thereof, said mount including an aperture; a camera body including a movable member movable to any position corresponding to any position of said movable lens group, and means for determining the position of said movable member;/an intermediate member for interconnecting said movable member and said lens drive member upon coupling of said exchangeable lens with said camera body such that the position of said movable member determines the position of said movable lens group, said intermediate member being included in said exchangeable lens and extending through said aperture of said lens mount, said movable member including an abutting member abutting with said intermediate member from one direction to form one-directional engagement therewith; and biasing means for abutting said intermediate member and said abutting member.
Claim 3
Dependent Claim
44 words
An automatic focusing system as claimed in claim 1 wherein said intermediate member includes an elongated member provided in said objective lens to move in the plane normal to the optical axis of said lens and extending in the direction of said optical axis.
Claim 4
Dependent Claim
70 words
An automatic focusing system as claimed in claim 2 further comprising a light receiving means for detecting the focus condition of said exchangeable lens and an electric circuit for controlling the position of said movable member in accordance with the output of said light receiving means, and said exchangeable lens further includes a signal means for enabling said electric circuit when said exchangeable lens is coupled with said camera body.
Claim 5
Dependent Claim
38 words
An automatic focusing system as claimed in claim 3 wherein said electric circuit includes a power switch and said signal means includes means for closing said power switch upon coupling of said exchangeable lens with said camera body.
Claim 6
Dependent Claim
29 words
An automatic focusing system as claimed in claim 4 further comprising means for actuating said power switch in response to a finger operated touch mechanism on the camera body.
Claim 7
Dependent Claim
63 words
An automatic focusing system as in claim 1 wherein said intermediate member is interconnected with said movable member upon coupling of said exchangeable lens with the camera body and further comprising cam means for transmitting movement of said intermediate member to said movable lens group such that the lateral position of said movable member determines the axial position of said movable lens group.
References Cited (Backward Citations)
US3683777A
Cited
US3798660A
Cited
US3827064A
Cited
US3914026A
Cited
US3940777A
Cited
US3972056A
Cited
US4092656A
Cited
DE2734725A1
Cited
US4146317A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-06-22 | 1984-12-22 | 1985-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-22 | 1988-12-22 | 1989-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-22 | 1992-12-22 | 1993-06-23 | $7700.00 | Window Closed / Lapsed |