US4402589A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Correct exposure annunciating device
Assignee: Canon Inc
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Filing: 1982-03-08
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Granted: 1983-09-06
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Expires: 2002-03-08
Abstract
Abstract A correct exposure annunciator has an element to indicate a correct exposure. The indicating element is energized in normal flash photography to indicate correct exposure. When abnormal flash photography is carried out, the element is de-energized by a signal, representing the AE mode, and the light is turned off.
Inventors
- 👤 Masaharu Kawamura
- 👤 Hiroyuki Kataoka
- 👤 Makoto Katsuma
- 👤 Masanori Uchidoi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:06
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/18
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
60 words
A correct exposure annunciating device having a correct exposure annunciating means, driving means to receive a correct exposure annunciating signal from a flash unit for driving said annunciating means, and means to detect a mode of a camera before a release operation of said camera and to override said annunciating means when the detection result thereof indicates an AE mode.
Claim 2
Dependent Claim
60 words
A correct exposure annunciating device having a correct exposure annunciating means, driving means to receive a correct exposure annunciating signal from a flash unit for driving said annunciating means, and means to detect a mode of a camera before a release operation of said camera and to override said annunciating means when the detection result thereof indicates an AE mode.
Claim 3
Dependent Claim
72 words
A correct exposure annunciating device according to claim 1, wherein said overriding means contains a circuit which detects a first signal from said flash unit to indicate a state of preparation of the flash unit in response to said release operation and produces an inhibition signal when the first signal indicates a state of incomplete preparation, and a circuit which overrides said correct exposure annunciating signal in response to said inhibition signal.
Claim 4
Dependent Claim
28 words
A correct exposure annunciating device according to claim 2, wherein said overriding circuit includes an AND gate connected between the inhibition signal producing circuit and the driving means.
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) | 1986-09-05 | 1987-03-07 | 1987-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-05 | 1991-03-07 | 1991-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-05 | 1995-03-07 | 1995-09-06 | $7700.00 | Window Closed / Lapsed |