Patent · US Expired

Apparatus for detecting theft by a radio wave

US6304182A · kind A · utility

40Cited by
13References
22Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 24, 1998
Grant dateOct 16, 2001
Priority date
Expiry dateDec 24, 2018

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG08B13/248
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

A burglar detection apparatus has a tag 11 that includes a resonance circuit. The tag is preferably contained with an object 15 whose theft is desired to be detected. The tagged object may be placed in a drawer 14 which is contained in a box 13. A tag detection sensor 16 is installed in the box and detects whether the tag 11 is present in the drawer 14. Also, a drawer sensor 17 detects whether the drawer is opened. Based on respective detection outputs of the tag detection sensor 16 and the drawer sensor 17, a control circuit 19 controls an alarm 18. Advantageously, the apparatus can be installed in a comparatively small space, does not malfunction even if subjected to large amounts of electrical noise, and reliably detects the presence or absence of a tag even if the tag is located near a metal object.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.