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Patent Searching and Data


Title:
WIRELESS SECURITY SYSTEM
Document Type and Number:
Japanese Patent JPH06269062
Kind Code:
A
Abstract:

PURPOSE: To prevent the occurrence of mutual interference by adopting the spread spectrum communication system for the wireless communication system so as to revise a duty ratio of a burst wave for each wireless communication system.

CONSTITUTION: A duty ratio of a burst wave is revised by a binary number of a PN signal in a PN generator 4 for each wireless communication or a frequency division ratio of the burst wave is revised by a frequency divider 2. A burst wave subject to phase modulation by the PN signal is applied to a controller side antenna A and an induced voltage is produced in a sensor S. On the other hand, the energy stored in a solidstate resonator 16 causes an echo in the antenna A by electromagnetic induction. In order to make synchronization detection while executing spread spectrum demodulation, an output signal of a phase modulator and a signal from a transmission reception antenna 7 are multiplied by a synchronization detector 11 and a detected output signal is obtained through a LPF 12. A processing/display device 13 discriminates whether or not an echo is in existence in the sensor S to discriminate the closing state of a door, window, crescent and lock or the like.


Inventors:
MASAKADO AKIROU
ISHII TETSUYA
Application Number:
JP1993000055809
Publication Date:
September 22, 1994
Filing Date:
March 16, 1993
Export Citation:
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Assignee:
SEKISUI CHEMICAL CO LTD
International Classes:
E05B45/06; E05B49/00; G08B13/08; H04Q9/00; (IPC1-7): H04Q9/00; E05B45/06; E05B49/00; G08B13/08