The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 25, 1997
Filed:
Sep. 13, 1994
Makoto Hasegawa, Tokyo, JP;
Masahiro Mimura, Tokyo, JP;
Hirohide Hirabayashi, Yokohama, JP;
Naoki Adachi, Kawasaki, JP;
Yasuaki Namura, Yokohama, JP;
Hideko Sakai, Yokohama, JP;
Abstract
A first mobile unit identification system having a interrogator and responder. The interrogator transmits a given magnitude of a spread spectrum coded signal in standby mode. The responder receives the spread spectrum coded signal and when the magnitude of received signal exceeds a given value, it reflects the transmitted spread spectrum coded signal with ID code when the magnitude of received signal exceeds the given value. The interrogator receives this and then, transmits data to the responder with amplitude modulating the spread spectrum coded signal with the data. The responder detects by amplitude demodulation and stores the detected data. The interrogator may transmit a mode change code. The responder may transmit an end code after transmission of a data train. A second interrogator informs the responder of the standby mode thereof by amplitude-modulated signal having a given cycle. A second responder judges whether or not the second interrogator is in standby mode by detecting the cycle and sends a communication requesting signal Q to the second responder and then, transmits ID code. In response to the signal Q, tile second interrogator transmits a signal having a fixed magnitude. A method of modulating for the mobile unit identifying system is also disclosed.