US3720152A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic exposure control apparatus for a camera
Assignee: Canon Inc
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Filing: 1970-05-13
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Granted: 1973-03-13
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Expires: 1990-05-13
Abstract
Abstract In the electronic exposure control apparatus disclosed the shutter blades also serve as diaphragm blades. An actuating mechanism moves the shutter blades in response to a shutter release. At the same time, the actuating mechanism or shutter release starts charging a capacitor on the basis of the response of a photocell to ambient light. When the capacitor reaches a given state of charge an electric circuit constrains the actuating mechanism to stop the blades from opening and to reclose. A lock device in the actuating mechanism holds the release in the position in which it causes the actuating mechanism to start opening the blades until the electric circuit constrains the the actuating mechanism to reclose the blades.
Inventors
- 👤 T Uchiyama
- 👤 K Sorimachi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:19
CPC Classifications
G; G03; G03B; G03B9/00; G03B9/58; G03B7/00; G03B7/08; G03B7/081; G03B7/087
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
171 words
An electronic exposure control apparatus for a camera comprising a shutter blade which functions as a diaphram blade, an actuating member coupled to said shutter blade for opening the shutter blade, a timer circuit, an electro-magnet responsive to said timer circuit, controller means responsive to said electromagnet for constraining said actuating member to close the shutter blade, triggering means connected to said actuating member for constraining the actuating member to start opening the shutter blade, a starter switch in said timer circuit, an energizing switch in said timer circuit, and shutter release means movable from a first position to a second position for actuating said triggering means and said starter switch as well as said energizing switch, said triggering means including a mechanical governor, said mechanical governor being rotatable in one direction, said mechanical governor including means for holding said shutter release means in the second position and means for causing said governor to cause said release means to return to the first position in response to operation of said electro-magnet.
Claim 2
Dependent Claim
171 words
An electronic exposure control apparatus for a camera comprising a shutter blade which functions as a diaphram blade, an actuating member coupled to said shutter blade for opening the shutter blade, a timer circuit, an electro-magnet responsive to said timer circuit, controller means responsive to said electromagnet for constraining said actuating member to close the shutter blade, triggering means connected to said actuating member for constraining the actuating member to start opening the shutter blade, a starter switch in said timer circuit, an energizing switch in said timer circuit, and shutter release means movable from a first position to a second position for actuating said triggering means and said starter switch as well as said energizing switch, said triggering means including a mechanical governor, said mechanical governor being rotatable in one direction, said mechanical governor including means for holding said shutter release means in the second position and means for causing said governor to cause said release means to return to the first position in response to operation of said electro-magnet.
Claim 3
Dependent Claim
171 words
An electronic exposure control apparatus for a camera comprising a shutter blade which functions as a diaphram blade, an actuating member coupled to said shutter blade for opening the shutter blade, a timer circuit, an electro-magnet responsive to said timer circuit, controller means responsive to said electromagnet for constraining said actuating member to close the shutter blade, triggering means connected to said actuating member for constraining the actuating member to start opening the shutter blade, a starter switch in said timer circuit, an energizing switch in said timer circuit, and shutter release means movable from a first position to a second position for actuating said triggering means and said starter switch as well as said energizing switch, said triggering means including a mechanical governor, said mechanical governor being rotatable in one direction, said mechanical governor including means for holding said shutter release means in the second position and means for causing said governor to cause said release means to return to the first position in response to operation of said electro-magnet.
Claim 4
Dependent Claim
171 words
An electronic exposure control apparatus for a camera comprising a shutter blade which functions as a diaphram blade, an actuating member coupled to said shutter blade for opening the shutter blade, a timer circuit, an electro-magnet responsive to said timer circuit, controller means responsive to said electromagnet for constraining said actuating member to close the shutter blade, triggering means connected to said actuating member for constraining the actuating member to start opening the shutter blade, a starter switch in said timer circuit, an energizing switch in said timer circuit, and shutter release means movable from a first position to a second position for actuating said triggering means and said starter switch as well as said energizing switch, said triggering means including a mechanical governor, said mechanical governor being rotatable in one direction, said mechanical governor including means for holding said shutter release means in the second position and means for causing said governor to cause said release means to return to the first position in response to operation of said electro-magnet.
References Cited (Backward Citations)
US3437026A
Cited
US3548732A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-12 | 1976-09-11 | 1977-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-12 | 1980-09-11 | 1981-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-12 | 1984-09-11 | 1985-03-13 | $7700.00 | Window Closed / Lapsed |