Kabushiki Kaisha Toshiba

Kazuki Iwata

Tsuneshi Yokota

Kiyohito Sudo

A no-battery information storage medium has a radio communication function of receiving power while receiving an externally transmitted radio wave as modulated data, and transmitting data outside the medium. One transmission/reception antenna coil performs transmission/reception. A first full-wave rectifying circuit is constituted by four rectifying elements connected to each other by bridging connection and connected to the two terminals of the transmission/reception antenna coil. A second full-wave rectifying circuit is constituted by four rectifying elements, including two shared rectifying elements of the four rectifying elements constituting the first full-wave rectifying circuit, connected to each other by bridging connection and connected to the two terminals of the transmission/reception antenna coil. A power generating section is connected to the output of the first full-wave rectifying circuit to generate power to be used inside the information storage medium. A constant-current driver section is connected to the output of the second full-wave rectifying circuit to perform transmission by extracting a predetermined current from an output from the second full-wave rectifying circuit in accordance with transmission data.

No-battery information storage medium capable of efficiently

A reader/writer transmits power and modulated data to a no-battery information storage medium having a communication function in a noncontact state, and receives modulated data from the no-battery information storage medium. The reader/writer has a driver, a loop antenna, and a current detection unit. The driver transmits the power and the modulated data. The loop antenna is connected to the output line of the driver. The current detection unit is arranged between the loop antenna and the output line of the driver. While the reader/writer supplies a transmission carrier current from the driver to the loop antenna, if it receives the modulated data from the no-battery information storage medium, it uses the current detection unit to extract, as a reception signal, a change in transmission carrier current of the loop antenna caused by the modulated data signal received by the loop antenna.

Growing community of inventors

Yokohama, Japan

Kazuki Iwata