Photoflash detector

• US 4,494,852 A
• Filed: 05/25/1983
• Issued: 01/22/1985
• Est. Priority Date: 05/25/1983
• Status: Expired due to Term

• Current Assignee: Roland Smith Jr
• Original Assignee: Roland Smith Jr
• Inventors: Smith, Roland Jr.
• Primary Examiner(s): Perkey, William B.
• Application Number:
  US06/497,880
• Time in Patent Office: 608 Days
• Field of Search: 354/127.1, 354/127.11, 354/127.12, 354/424, 354/467, 340/600, 340/309.15, 340/322, 340/384 R, 340/815.3, 340/384 E, 315/134, 315/136, 315/151, 315/241 P, 315/135
• US Class Current: 396/201
• CPC Class Codes: G03B 17/18 Signals indicating condition of a camera member or suitability of light indicating depth of field G03B13/30

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.

Claims

1. 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.

2. A photoflash detector according to claim 1, wherein said housing is light-transparent adjacent said light-activated SCR for passing light onto the latter.

3. 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.

4. 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.

5. A photoflash detector according to claim 4 wherein said housing has an opening for passing light onto said light-activated SCR.