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:
May. 03, 1994
Filed:
Jan. 14, 1991
David K Lacombe, Downey, CA (US);
George J Seelman, Temple City, CA (US);
Michael C Scofield, Arcadia, CA (US);
Other;
Abstract
A security system uses a base unit and a portable transceiver which cooperate to provide automatic monitoring of a secure perimeter. An intrusion sensor is employed to activate a transmitter for emitting a selected frequency wave energy challenge transmission upon the detection of an intruder either outside the perimeter or entering the perimeter. If the intruder has the portable transceiver present to receive the challenge transmission, it automatically emits a responsive wave energy signal as an acknowledgment. A base unit receiver detects the acknowledgment signal and prohibits alarm action. If no acknowledgment signal is received, then either a warning or an alarm is triggered at the base unit. The system does not require manual control. The several distinct wave energy signals can be chosen from among various available radio frequency electromagnetic, and audible or ultrasonic acoustic, waves. An advantage of making one of the communication links by acoustic transmission is that the system disarms itself automatically only when the portable transceiver is within a precisely defined distance of the base unit.