Omron Corporation

Hirokazu Kasai

Hidekatsu Nogami

Tatsuo Yoshida

Shuichi Matsui

Yahiro Koezuka

Takehiro Kawai

Tomonori Ariyoshi

Arata Kataoka

Kazushi Yamasaki

Yoshito Okuno

Kenta Kawakami

An antenna is disposed near a route of mobile object. A fixed tag is disposed at a location where a radio wave can be received from the antenna. When receiving a read command from the antenna, a mobile tag attached to the mobile object and the fixed tag send back a response signal at prescribed timing. A signal received from the fixed tag by the antenna is substantially constant. The signal from the fixed tag cannot be read while buried in a signal transmitted from the mobile tag to the antenna while the mobile tag is positioned at a location where communication with the antenna is expected. Conversely, when the mobile tag is at least a prescribed distance away from the antenna, the signal from the mobile tag cannot be read while buried in the signal from the fixed tag.

RFID system

A communication processing apparatus alternately transmits a carrier wave carrying a command and receives a response from a tag while transmitting an unmodulated carrier wave. A transmission control unit changes the phase of the unmodulated carrier wave transmitted from a transmission/reception circuit in response to start of reception of the reflected wave from the tag. The transmission/reception circuit includes a circuit for separating and detecting an I signal and a Q signal included in the reflected wave from the tag. A phase detection unit uses the I signal and the Q signal to detect change of the phase of the reflected wave. A distance calculation unit measures a time from a change of the phase of the unmodulated carrier wave to a detection of a corresponding change in the phase of the reflected wave, and uses the time to calculate the distance from the antenna to the tag.

Communication processing apparatus and distance measuring method for communication processing apparatus

It is possible to provide a tag communication device, a tag communication system, and a tag communication method which can secure an optimal communication region even when an antenna installation environment or a peripheral environment changes. A tag A is arranged in a preset communication region while a tag B is arranged outside the communication region. A reader/writer () repeatedly scans a radio beam M emitted from a scan antenna () and then controls the radio beam so that all the tags A can be read while no tag B can be read according to the ID which has been read.

Tag communication device, tag communication system, and tag communication method

A tag communication apparatus conducts wireless communication with an RFID tag through a radio wave. The tag communication apparatus includes a data receiver that receives transmit data to be transmitted to the RFID tag, a data compressor that compresses at least a part of the transmit data obtained by the data receiver, and outputs the compressed data, and a transmitter that transmits the compressed data, which is compressed and output by the data compressor, to the RFID tag.

Tag communication apparatus, tag communication apparatus control method, and tag communication apparatus control program

A radio frequency signal oscillator and an intermediate frequency signal oscillator are incorporated in a communication processing device, and a carrier wave with which an intermediate frequency signal is overlapped is generated using the oscillators and transmitted from an antenna. Mixers separate and extract an I signal and a Q signal from the intermediate frequency signal in the signal received by the antenna. A phase difference detector detects a phase difference of the intermediate frequency signal in a reflected wave to the intermediate frequency signal in the carrier wave using the I signal and the Q signal after the reception of the reflected wave from a tag is started. A distance calculator calculates a distance from the antenna to the tag using the phase difference and a wavelength of the intermediate frequency signal.

Communication processing device and distance measurement method in communication processing device

To improve communication between tags by causing a mobile object having a RFID tag attached to transmit an interrogating wave only when moving in a communication range to reduce power consumption and prevent occurrence of tag confusion. By acquiring two Doppler signals from 2-frequency transmission waves (CW) with different frequencies and respective reflected waves and detecting phase difference from the Doppler signals, a cargo (A) is detected to be moving in the communication range (A). Only when the movement is detected, a reader-writer (A) transmits the interrogating wave (RW).

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Kyoto, Japan

Hirokazu Kasai