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Burglarproof device

  • US 5,068,643 A
  • Filed: 03/05/1990
  • Issued: 11/26/1991
  • Est. Priority Date: 03/27/1989
  • Status: Expired due to Fees
First Claim
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1. A theft prevention device comprising an optical sensor for detecting a level of ambient light, a vibration sensor for detecting vibration of a protected article, and an alarm circuit operatively coupled to the optical sensor and the vibration sensor for providing an alarm when the optical sensor detects a change in the level of ambient light from relative brightness to relative darkness and the vibration sensor detects a vibration of the protected article.

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  • 2 Assignments
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