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.

Date of Patent:
Jan. 08, 1991

Filed:

Jun. 12, 1989
Applicant:
Inventors:

Akimitsu Ogata, Takatsuki, JP;

Hisato Fujisaka, Izumi, JP;

Sadao Igarashi, Kamifukuoka, JP;

Toshimitsu Nozu, Hino, JP;

Katsura Onozato, Tokyo, JP;

Masanobu Hirose, Fuchu, JP;

Katsuji Miwa, Souka, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G08G / ;
U.S. Cl.
CPC ...
342 42 ; 342 44 ;
Abstract

A data transmission system includes a data carrier which has a memory for storing therein data including an identification code and which is attached to an object and a main apparatus having a microwave oscillator so as to conduct communications with the data carrier by use of a microwave, thereby writing data in or reading data from the memory of the data carrier. The main apparatus transmits a microwave modulated by a command or data and thereafter transmits a nonmodulated carrier for a predetermined period of time. On receiving a command, the data carrier executes a read/write operation on the memory and then generates a response. The data carrier receives the nonmodulated carrier sent from the main apparatus so as to conduct a modulation of quadrature phase-shift keying thereon by use of response data, thereby reflectively transmitting the modulated carrier with a plane of polarization shifted from a plane of polarization of the received wave by 90.degree..


Find Patent Forward Citations

Loading…