The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 31, 1978
Filed:
Mar. 28, 1977
Applicant:
Inventors:
Assignee:
Bizerba-Werke Wilhelm Kraut KG, Balingen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G08B / ;
U.S. Cl.
CPC ...
340572 ;
Abstract
A surveillance system for preventing shoplifting comprises marking elements made of material of high magnetic permeability attached to the goods in a store, and magnetic field generating coils generating a magnetic field in the exit areas from the store. Two different alternating magnetic fields are produced on opposite sides so that the configuration of the field within the exit area is continuously changing. Introduction of a marking element into this area causes different frequencies to be produced which are sensed by a sensing element which then emits a signal. The marking elements can be deactivated during a normal purchase by magnetically saturating the material.