Opto-electronic security fence

• US 5,198,799 A
• Filed: 09/26/1991
• Issued: 03/30/1993
• Est. Priority Date: 09/26/1991
• Status: Expired due to Fees

• Current Assignee: Bendix Avelex Incorporated
• Original Assignee: Alliedsignal Inc.
• Inventors: Pascale, Danny
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US07/766,500
• Time in Patent Office: 551 Days
• Field of Search: 340/552, 340/555-557, 340/693, 340/505, 340/825.54, 340/524, 340/541, 340/825.05, 340/825.49, 340/502, 340/504, 342/27, 367/93, 250/221, 455/88, 455/90
• US Class Current: 340/552
• CPC Class Codes: G08B 13/122 for a perimeter fence features peculiar to electrified fences A01K3/00
• CPC Class Codes: G08B 13/183 by interruption of a radiation beam or barrier

Abstract

A surveillance fence comprising at least two posts (10) each equipped with electro-magnetic radiation transmitters (12) and receivers (14) which establish two parallel communications links. Each posts (10) communicate with a surveillance computer at a headquarters (20). Only one post (10) communicates directly via cables with headquarters (20). Data is transmitted over the communication links in opposite directions by modulating the electromagnetic energy beams. A message starts at headquarters (20) and is passed along post (10) to post (10) and back again to headquarters (20). Each post (10) can add information to the message as it is passed along. The interruption of the electromagnetic energy beams signals an intrusion whose location and time of occurence is recorded by a processor (16) which initiates an alarm. If a post (10) can not relay its intrusion data, the data is stored until the communications link is reestablished. The intrusion data stored at a post (10) will not be erased until an acknowledge message is received from headquarters (20).

Claims

1. A post for use in an electromagnetic security fence comprising;

a plurality of electromagnetic energy beam transmitters;

a plurality of electromagnetic energy beam receivers;

a processing unit for modulating the electromagnetic energy beam transmitted from said transmitters for adding information to the beam;

batteries for providing power for operation;

means for communicating with a computer at a remote surveillance headquarters;

a detector for detecting when the electro-magnetic energy beam to a receiver is interrupted; and

memory means for storing information concerning an interruption in the electromagnetic beam received by one of said receivers when such information cannot be communicated to the computer at the remote surveillance headquarters and for sending the information when the communication is reestablished.

2. A post as claimed in claim 1, further comprising:

a vertical tubular member having said transmitters and said receivers adjustably secured thereto; and

a tripod base for supporting said vertical post and housing said processor and said battery.

3. A post as claimed in claim 2, wherein said tripod base includes means for leveling said base and securing said base to the ground.

4. A security fence using a plurality of spaced apart fence posts which can communicate with a surveillance headquarters computer, each post comprising:

a transmitter for sending an electromagnetic beam to an adjacent post;

a receiver for receiving an electromagnetic beam from an adjacent post;

processor means connected to said transmitter and said receiver for modulating the electromagnetic beam sent by said transmitter to add information indicating an interruption in the electromagnetic beam received by said receiver; and

,

memory means for storing information concerning an interruption in the electromagnetic beam received by said receiver when such information cannot be communicated to the surveillance headquarters computer.