US3900856A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic exposure control device
Assignee: Canon Inc
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Filing: 1973-06-14
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Granted: 1975-08-19
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Expires: 1993-06-14
Abstract
Abstract In an exchangeable lens type camera incorporating an exposure meter therein, an automatic exposure control device comprises means for scanning an ammeter needle, aperture control means and a single drive means for driving the scanning means and the control means to control the lens aperture and actuate the diaphragm in accordance with the displacement of the ammeter needle. A transmission member is provided for driving therethrough the scanning means from the drive means. The transmission member is engageable with a lock member during scanning movement to transmit the movement of the drive means to the scanning means while retaining the lock member at a predetermined position, and may release the lock member with the aid of a reaction force produced upon engagement of the scanning means with the needle, thereby permitting the lock member to prevent movement of the drive means.
Inventors
- 👤 Tatsuya Taguchi
- 👤 Yukio Iura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:45
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/081; G03B7/085; G03B19/00; G03B19/02; G03B19/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
444 words
An automatic exposure control device in an interchangeable lens type camera incorporating an exposure meter having an indicator therein, comprising: means for scanning said indicator of the exposure meter, said scanning means including a movable scanning member, a stop member, and restoring spring means for said movable member; aperture control means; drive means for said movable member of said scanning means and for said aperture control means, said drive means including means for release of said drive means from an initial position thereof and for rotation thereof in a predetermined direction upon initiation of picture taking; a pivoted locking member shaped and disposed for locking said drive means, in one position of said locking member, by a locking engagement with said drive means, said locking member being biased by bias means for the direction of movement towards said position of locking engagement; first mechanical transmission means for transmitting the driving force of said drive means to said aperture control means; second mechanical transmission means for transmitting the driving force of said drive means to said movable member of said scanning means, including a rocker lever pivotably mounted on a force delivery member of said second transmission means and having one end engageable with said locking member and having pivot coupling means on its other end to which said movable member of said scanning means is pivotably coupled for linkage of movement; said locking member being so mounted and the mutually engaging portions of said locking member and of said rocker lever being so shaped and disposed as to provide a point of rocking engagement of said rocker lever on said locking member which is necessary for maintaining force transmission capability between said rocker lever and said movable member of said scanning means and which is also effective to maintain, said locking member out of engagement with said drive means, so long as movement of said movable member is not arrested by said stop member, while said rocker lever pivots about said point of rocking engagement of said rocker lever on said locking member, said mutually engaging portions providing said rocking engagement being also shaped and disposed that upon arrest of said movable member by said stop means, said rocker lever is forced to pivot on said force delivery member of said second transmission means to disengage from and release said locking member, thereby permitting said locking member to engage with and lock said drive means and simultaneously releasing said movable member of said scanning means for restoration of its initial position by said restoring spring means of said scanning means, regardless of the position of said force delivery member of said second transmitting means.
Claim 2
Dependent Claim
444 words
An automatic exposure control device in an interchangeable lens type camera incorporating an exposure meter having an indicator therein, comprising: means for scanning said indicator of the exposure meter, said scanning means including a movable scanning member, a stop member, and restoring spring means for said movable member; aperture control means; drive means for said movable member of said scanning means and for said aperture control means, said drive means including means for release of said drive means from an initial position thereof and for rotation thereof in a predetermined direction upon initiation of picture taking; a pivoted locking member shaped and disposed for locking said drive means, in one position of said locking member, by a locking engagement with said drive means, said locking member being biased by bias means for the direction of movement towards said position of locking engagement; first mechanical transmission means for transmitting the driving force of said drive means to said aperture control means; second mechanical transmission means for transmitting the driving force of said drive means to said movable member of said scanning means, including a rocker lever pivotably mounted on a force delivery member of said second transmission means and having one end engageable with said locking member and having pivot coupling means on its other end to which said movable member of said scanning means is pivotably coupled for linkage of movement; said locking member being so mounted and the mutually engaging portions of said locking member and of said rocker lever being so shaped and disposed as to provide a point of rocking engagement of said rocker lever on said locking member which is necessary for maintaining force transmission capability between said rocker lever and said movable member of said scanning means and which is also effective to maintain, said locking member out of engagement with said drive means, so long as movement of said movable member is not arrested by said stop member, while said rocker lever pivots about said point of rocking engagement of said rocker lever on said locking member, said mutually engaging portions providing said rocking engagement being also shaped and disposed that upon arrest of said movable member by said stop means, said rocker lever is forced to pivot on said force delivery member of said second transmission means to disengage from and release said locking member, thereby permitting said locking member to engage with and lock said drive means and simultaneously releasing said movable member of said scanning means for restoration of its initial position by said restoring spring means of said scanning means, regardless of the position of said force delivery member of said second transmitting means.
Claim 3
Dependent Claim
86 words
A device according to claim 1, in which said aperture control means includes a diaphragm actuator means and in which means are further provided for restraining the diaphragm actuator means during the operation of said drive means including means for interlocking said restraining means with said locking member shaped and disposed for release of said restraining means, and thereby for release of said diaphragm actuator means into operation, in response to movement of said locking member to its position of locking engagement with said drive means.
Claim 4
Dependent Claim
31 words
A device according to claim 1, wherein said drive means is controlled by a speed governor mechanism to drive said aperture control means and said scanning means at a predetermined speed.
Claim 5
Dependent Claim
35 words
A device according to claim 3, wherein said speed governor mechanism is provided with a stop member engageable with said locking member to provide said locking engagement of said locking member with said drive means.
Claim 6
Dependent Claim
118 words
A device according to claim 1, further provided with start lever means for locking said driving means in an initial position thereof, change-over means having a setting for an automatic exposure control mode and at least one setting for a manual exposure control mode and means responsive to the setting of said change-over means to said manual exposure control mode for holding said start lever means in a position locking said driving means in said initial position when said change-over means is set to the manual exposure mode while allowing said start lever means to be released from such locking position upon initiation of picture taking when said change-over means is set to the automatic exposure control mode.
References Cited (Backward Citations)
US3148602A
Cited
US3677149A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-18 | 1979-02-17 | 1979-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-18 | 1983-02-17 | 1983-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-18 | 1987-02-17 | 1987-08-19 | $7700.00 | Window Closed / Lapsed |