US4494852A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photoflash detector
Assignee: Individual
•
Filing: 1983-05-25
•
Granted: 1985-01-22
•
Expires: 2003-05-25
Abstract
Abstract A self-contained photodetector for detecting the light flash from a photoflash unit which is supposed to flash when the shutter of a camera opens. The detector has a light-activated SCR for turning on an IC chip timer, which produces an output signal that turns on a transistor and causes a piezoelectric buzzer to produce an audible signal. All these components are powered by a battery which is contained in the same housing with them. This housing has an opening for passing light onto the SCR.
Inventors
- 👤 Roland Smith, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:40
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/18
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
117 words
A photoflash detector for use with a camera having a photoflash unit for producing a flash of light when the camera shutter opens, said detector comprising: a light-activated SCR electrically disconnected from said photoflash unit and operatively arranged to be activated in response to a flash of light from the photoflash unit; a signalling device which produces an audible signal; circuit means operatively coupling said light-activated SCR to said signalling device to operate the latter in response to the activation of said SCR; a battery operatively connected to power said light-activated SCR, said signalling device and said circuit means; and a housing containing said battery, light-activated SCR, signalling device and circuit means to provide a self-contained unit.
Claim 2
Dependent Claim
117 words
A photoflash detector for use with a camera having a photoflash unit for producing a flash of light when the camera shutter opens, said detector comprising: a light-activated SCR electrically disconnected from said photoflash unit and operatively arranged to be activated in response to a flash of light from the photoflash unit; a signalling device which produces an audible signal; circuit means operatively coupling said light-activated SCR to said signalling device to operate the latter in response to the activation of said SCR; a battery operatively connected to power said light-activated SCR, said signalling device and said circuit means; and a housing containing said battery, light-activated SCR, signalling device and circuit means to provide a self-contained unit.
Claim 3
Dependent Claim
22 words
A photoflash detector according to claim 1, wherein said housing is light-transparent adjacent said light-activated SCR for passing light onto the latter.
Claim 4
Dependent Claim
57 words
A photoflash detector according to claim 1, wherein said circuit sense means comprises: a timer operatively connected to said light-activated SCR to be turned on when said SCR is activated; and a transistor operatively connected to said timer and said signalling device to turn on said signalling device in response to the turning on of the timer.
Claim 5
Dependent Claim
33 words
A photoflash detector according to claim 3, and further comprising: a manual switch connected between said battery and said light-activated SCR to turn the latter off after said signalling device is turned on.
Claim 6
Dependent Claim
20 words
A photoflash detector according to claim 4 wherein said housing has an opening for passing light onto said light-activated SCR.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-22 | 1988-07-23 | 1989-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-22 | 1992-07-23 | 1993-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-22 | 1996-07-23 | 1997-01-22 | $7700.00 | Window Closed / Lapsed |