Security alarm system

• US 4,559,526 A
• Filed: 04/06/1983
• Issued: 12/17/1985
• Est. Priority Date: 06/29/1982
• Status: Expired due to Term

• Current Assignee: Secom Company Limited
• Original Assignee: Secom Company Limited
• Inventors: Watanabe, Tsutomu, Tani, Kozaburo
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US06/482,484
• Time in Patent Office: 986 Days
• Field of Search: 340/539, 340/506, 340/531, 340/534, 340/505, 340/345, 340/693, 455/7, 455/9, 455/11, 455/13, 455/14, 455/15, 455/39, 455/53, 455/54, 455/73
• US Class Current: 340/539.3
• CPC Class Codes: G08B 23/00 Alarms responsive to unspecified undesired or abnormal conditions
• CPC Class Codes: G08B 25/10 using wireless transmission systems G08B25/009 takes precedence
• CPC Class Codes: G08B 29/046 prevention of tampering with detection circuits

Abstract

A security system comprising a plurality of sensors for detecting emergencies in a predetermined guard area, a transmitter-receiver for converting the emergency data into electric signals and transmitting the electric signals via a radio, a repeater for receiving the electric signals from the transmitter-receiver and transmitting the signal to a security controller, a security controller for setting a guard mode such as "start watch", and "release the watch" and transmitting the emergency and ordinary data to a central station through a transmission line such as a telephone cable or personal circuit, and a central station for supervising the predetermined guard area based on the data from this and other security controllers.

Claims

1. A security alarm system for watching emergency situations in a predetermined guard area comprising:

a plurality of sensors for detecting the emergencies;

a transmitter-receiver for a guard area connected to said sensors and having a battery power source;

a repeater associated with said transmitter-receiver through radio;

a security controller connected to said repeater; and

a central station connected to said security controller using a transmission line and giving a guard command to an operator on the basis of emergency or ordinary data transmitted from said security controller;

means for providing a pulsating voltage from said power source for the guard area such that a predetermined pulsating voltage is applied from said battery power source to said transmitter-receiver under ordingary conditions, a predetermined voltage having a longer term than a period of said pulsating voltage is applied to a receiving section of said transmitter-receiver in response to a watch signal transmitted from said security controller via said repeater before transmitting a guard mode signal from said security controller and a predetermined voltage having a longer term than the said pulsating voltage is applied to a transmitting section of said transmitter-receiver in response to an emergency signal transmitted from said sensors at emergencies, or in response to said guard mode signal transmitted from said security controller via said repeater;

said repeater stores the emergency and ordinary data transmitted from said transmitter-receiver temporarily; and

said security controller reads out these data stored in said repeater, discriminates emergency or ordinary data, and transmits emergency data and guard mode signal to said central station.

2. A security alarm system as claimed in claim 1 characterized in that the transmission of the signal is performed alternatively between said transmitter-receiver and said repeater.

3. A security alarm system as claimed in claim 1, characterized in that the transmission of the signal is performed through electromagnetic wave between said transmitter-receiver and said repeater.

4. A security alarm system as claimed in claim 1, characterized in that the transmission of the signal is performed through ultrasonic waves between said transmitter-receiver and said repeater.

5. A security alarm system as claimed in claim 1, characterized in that the transmission of the signal is performed through infrared rays between said transmitter-receiver and said repeater.