Title:
MULTIPLICATION REFLECTION TYPE RADIO WAVE MARKER, MARKER DETECTOR, MARKER SYSTEM, AND TRAFFIC SYSTEM
Document Type and Number:
Japanese Patent JP2002342877
Kind Code:
A
Abstract:
To solve a problem that because a system for time-sequentially transmitting electromagnetic waves of a plurality of frequencies needs many frequencies to use and a system using an information tag with an IC mounted needs many electronic parts to be mounted on a marker, system structures of both are complicated and lack in practicability as the marker buried in a road.
Two kinds of markers, of which coils used as a transmission antenna for reversing a phase of a transmitted electromagnetic wave by approximately 180° are wound clockwise and counterclockwise, are arranged alternately.
Inventors:
TANJI TAKAHIKO
HANDA SATORU
NAKATSUKA AKIRA
HANDA SATORU
NAKATSUKA AKIRA
Application Number:
JP2001142775A
Publication Date:
November 29, 2002
Filing Date:
May 14, 2001
Export Citation:
Assignee:
MATSUSHITA ELECTRIC IND CO LTD
International Classes:
G01S1/68; G08G1/042; G08G1/00; G08G1/0967; H04B5/02; G01S13/75; (IPC1-7): G08G1/00; G01S1/68; H04B5/02
Attorney, Agent or Firm:
Fumio Iwahashi (2 others)
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