Body exposure indicator

• US 3,924,130 A
• Filed: 02/12/1968
• Issued: 12/02/1975
• Est. Priority Date: 02/12/1968
• Status: Expired due to Term

• Current Assignee: Allen Cohen, Hugo J. Caligiuri
• Original Assignee: Allen Cohen, Hugo J. Caligiuri
• Inventors: Cohen, Allen, Caligiuri, Hugo J.
• Primary Examiner(s): Wilbur, Maynard R.
• Assistant Examiner(s): Buczinski, S. C.
• Application Number:
  US04/706,750
• Time in Patent Office: 2,850 Days
• Field of Search: 250/338,23CT,347,342 340/258B,221,251 244/3.17 343/5MM
• US Class Current: 250/342
• CPC Class Codes: G08B 13/194 using image scanning and comparing systems
• CPC Class Codes: Y10S 250/01 Passive intrusion detectors

Abstract

An infra-red detector is caused to scan a field of view periodically to detect warm bodied intruders or other personnel. Signals from the detector are compared with signals from a scene recorder containing a prerecorded picture of the same field of view made when no one was in the area. Any difference signal indicating a change in the field of view, such as might be caused by an enemy intruder in a combat area or by an overexposed trainee in a training exercise, actuates an alarm. A monitor display exhibits the scene viewed by the infra-red detector and an alarm recorder automatically records the scene when the alarm is actuated.

Claims

1. In a detector system for detecting the presence of warm bodies in a selected area, the improvement comprising:

detector means for periodically scanning said selected area to detect warm bodies therein, recorder means for periodically recording the signals developed by said detector means, comparator means for comparing the output signals from said detector means with previous signals from said detector means stored in said recorder means, alarm means for generating an alarm signal responsive to a difference signal from said comparator means when said detector output signal differs from said previous detector output signal recorded in said recorder means, and first gating means for selectively gating said difference signal from said comparator means to said alarm means.

2. The apparatus of claim 1 and including second gating means for selectively gating the output signal from said detector means to said recorder means, and control means for controlling said first and second gating means.

3. The apparatus of claim 2 wherein said control means comprise a presettable counter and first and second flip-floPs for selectively controlling said first and second gating means respectively.

4. The apparatus of claim 3 and including display means for displaying signals form said detector means as the scene viewed by said detector means.

5. The apparatus of claim 4 and including scanning generator means for furnishing synchronized output signals to control said detector means, control means, and display means, and means for selectively gating the signal from said detector means to said display means.

6. The apparatus of claim 5 and including an alarm recorder means and means for selectively gating the output signal of said detector means to said alarm recorder means.

7. The apparatus of claim 6 and including second control means responsive to an output signal from said comparator means to gate the output signal of said detector means to said alarm recorder means.

8. The apparatus of claim 7 wherein said second control means comprise a delay means, a switching means, counting means, a third gating means, and a fourth gating means, said delay means being connected to transmit a signal from said comparator means to said switching means, said switching means being connected to control said third gating means and said fourth gating means, said third gating means being connected to control the flow of output signals from said detector means to said alarm recorder means, said fourth gating means being connected to control the flow of count signals to said counting means, said counting means being connected to furnish a control signal to said switching means, whereby an output signal from said counting means is furnished to said switching means to cause said switching means to close said third and said fourth gating means.