Electromagnetic wave marker and electromagnetic wave marker system

• US 20040051430A1
• Filed: 06/10/2003
• Published: 03/18/2004
• Est. Priority Date: 09/26/2001
• Status: Abandoned Application

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Yasui, Keiji, Nomura, Koichi, Tanji, Yoshihiko, Handa, Satoru
• Application Number:
  US10/433,993
• Publication Number:
  US 20040051430A1
• Time in Patent Office: Days
• US Class Current: 313/113
• CPC Class Codes: G08G 1/042 using inductive or magnetic detectors
• CPC Class Codes: H01Q 1/3225 Cooperation with the rails or the road

Abstract

An electromagnetic-wave marker includes a bar-like receiving antenna for receiving an electromagnetic wave, a frequency converting circuit coupled to the receiving antenna and for multiplying a frequency of the electromagnetic wave, a disc-like transmitting antenna for transmitting an electromagnetic wave of which frequency is multiplied by the frequency converting circuit, a nonmagnetic container for accommodating and placing the receiving antenna and the transmitting antenna such that the received electromagnetic wave and the transmitting electromagnetic wave intersect with each other at right angles, and an electromagnetic-wave reflector placed at a lower portion of the nonmagnetic container and for reflecting the electromagnetic wave along the transmitted direction. The marker is improved its anti-corrosion property, and at the same time, reduces its thickness, so that the marker can be laid down in various structures of roads such as an iron bridge.

Claims

1. An electromagnetic-wave marker comprising:

a transmitting antenna for transmitting an electromagnetic wave;

a nonmagnetic container for accommodating the transmitting antenna; and

an electromagnetic wave reflector, disposed in the nonmagnetic container, for reflecting the electromagnetic wave along the transmitted direction.

4. The electromagnetic-wave marker of any one of claim 1 through claim 3, wherein the electromagnetic reflector is made from nonferrous metal.

5. The electromagnetic-wave marker of any one of claim 1 through claim 3, wherein the electromagnetic reflector is made from stainless steel.

6. The electromagnetic-wave marker of any one of claim 1 through claim 3, wherein the electromagnetic reflector is made from aluminum.

2. An electromagnetic-wave marker comprising:

a receiving antenna for receiving an electromagnetic wave;

a transmitting antenna for transmitting an electromagnetic wave;

a nonmagnetic container for accommodating the receiving antenna and the transmitting antenna; and

an electromagnetic wave reflector, disposed in the nonmagnetic container, for reflecting the electromagnetic wave along the transmitting direction.

3. An electromagnetic-wave marker comprising:

a receiving antenna, shaped like a bar, for receiving an electromagnetic wave;

a frequency converting circuit, coupled to the receiving antenna, for multiplying a frequency of the electromagnetic wave;

a transmitting antenna, shaped like a disc, for transmitting an electromagnetic wave of which frequency is multiplied by the frequency converting circuit;

a nonmagnetic container for accommodating and placing the receiving antenna and the transmitting antenna such that the received electromagnetic wave and the transmitting electromagnetic wave intersect with each other at right angles; and

an electromagnetic wave reflector, disposed in the nonmagnetic container, for reflecting the electromagnetic wave along the transmitted direction.

7. An electromagnetic-wave marker system comprising:

an electromagnetic-wave marker including;

a receiving antenna for receiving an electromagnetic wave;

a transmitting antenna for transmitting an electromagnetic wave;

a nonmagnetic container for accommodating the transmitting antenna and the receiving antenna; and

an electromagnetic wave reflector, disposed in the nonmagnetic container, for reflecting the electromagnetic wave along the transmitted direction;

another receiving antenna for receiving the electromagnetic wave transmitted from the marker; and

a marker detector for detecting an intensity of the electromagnetic wave received by the another receiving antenna.

8. An electromagnetic-wave marker system comprising:

an electromagnetic-wave marker including;

a receiving antenna, shaped like a bar, for receiving an electromagnetic wave;

a frequency converting circuit, coupled to the receiving antenna, for multiplying a frequency-of the electromagnetic wave;

a transmitting antenna, shaped like a disc, for transmitting an electromagnetic wave of which frequency is multiplied by the frequency converting circuit;

a nonmagnetic container for accommodating and placing the receiving antenna and the transmitting antenna such that the received electromagnetic wave and the transmitting electromagnetic wave intersect with each other at right angles; and

an electromagnetic wave reflector, disposed in the nonmagnetic container, for reflecting the electromagnetic wave along the transmitted direction,

another receiving antenna for receiving the electromagnetic wave transmitted from the marker; and

a marker detector for detecting an intensity of the electromagnetic wave received by the another receiving antenna.

9. An electromagnetic-wave marker system comprising:

an electromagnetic-wave marker including;

a receiving antenna for receiving an electromagnetic wave;

a transmitting antenna for transmitting an electromagnetic wave;

a nonmagnetic container for accommodating the transmitting antenna and the receiving antenna; and

an electromagnetic wave reflector, disposed in the nonmagnetic container, for reflecting the electromagnetic wave along the transmitted direction;

another receiving antenna for receiving the electromagnetic wave transmitted from the marker; and

a marker detector for detecting an intensity of the electromagnetic wave received by the another receiving antenna,

wherein a plurality of the markers are disposed discretely, and the marker detector detects the markers sequentially.

10. An electromagnetic-wave marker system comprising:

an electromagnetic-wave marker including;

a receiving antenna, shaped like a bar, for receiving an electromagnetic wave;

a frequency converting circuit, coupled to the receiving antenna, for multiplying a frequency of the electromagnetic wave;

a transmitting antenna, shaped like a disc, for transmitting an electromagnetic wave of which frequency is multiplied by the frequency converting circuit;

a nonmagnetic container for accommodating and placing the receiving antenna and the transmitting antenna such that the received electromagnetic wave and the transmitting electromagnetic wave intersect with each other at right angles; and

an electromagnetic wave reflector, disposed in the nonmagnetic container, for reflecting the electromagnetic wave along the transmitted direction,

another receiving antenna for receiving the electromagnetic wave transmitted from the marker; and

a marker detector for detecting an intensity of the electromagnetic wave received by the another receiving antenna,

wherein a plurality of the markers are disposed discretely, and the marker detector transmits/receives the electromagnetic wave to/from the markers sequentially.

13. The electromagnetic-wave marker system as defined in any one of claim 10 through claim 12, wherein the marker detector detects a position of the mobile unit with the electromagnetic waves received by the plurality of the another receiving antennas, and a recognition of the detected position of the mobile unit allows controlling a guidance and a stop position of the mobile unit.

11. An electromagnetic-wave marker system comprising:

an electromagnetic-wave marker including;

a receiving antenna for receiving an electromagnetic wave;

a transmitting antenna for transmitting an electromagnetic wave;

a nonmagnetic container for accommodating the transmitting antenna and the receiving antenna; and

an electromagnetic wave reflector, disposed in the nonmagnetic container, for reflecting the electromagnetic wave along the transmitted direction;

a plurality of another receiving antennas, mounted to a mobile unit along a driving direction, for receiving the electromagnetic waves transmitted from a plurality of the markers disposed discretely; and

a marker detector for comparing intensities of the respective electromagnetic waves received by the plurality of another receiving antennas.

12. An electromagnetic-wave marker system comprising:

an electromagnetic-wave marker including;

a receiving antenna, shaped like a bar, for receiving an electromagnetic wave;

a frequency converting circuit, coupled to the receiving antenna, for multiplying a frequency of the electromagnetic wave;

a transmitting antenna, shaped like a disc, for transmitting an electromagnetic wave of which frequency is multiplied by the frequency converting circuit;

a nonmagnetic container for accommodating and placing the receiving antenna and the transmitting antenna such that the received electromagnetic wave and the transmitting electromagnetic wave intersect with each other at right angles; and

an electromagnetic wave reflector, disposed in the nonmagnetic container, for reflecting the electromagnetic wave along the transmitted direction,

a plurality of another receiving antennas, mounted to a mobile unit along a driving direction, for receiving the electromagnetic waves transmitted from a plurality of the markers disposed discretely; and

a marker detector for comparing intensities of the respective electromagnetic waves received by the plurality of another receiving antennas.

14. The electromagnetic-wave marker system as defined in any one of claim 7 through claim 12, wherein the electromagnetic-wave reflector is made from nonferrous metal.

15. The electromagnetic-wave marker system as defined in any one of claim 7 through claim 12, wherein the electromagnetic-wave reflector is made from stainless steel.

16. The electromagnetic-wave marker system as defined in any one of claim 7 through claim 12, wherein the electromagnetic-wave reflector is made from aluminum.