Patent ID: 6427065
Filing Date: 2002-07-30
Classification: G06K,G07C,H01Q,H02J

Abstract:
A power transmission and information communication system in which power is transmitted by radio wave from a reader and/or writer device to an IC card and information is communicated by radio wave between the reader and/or writer device and the IC card, said IC card comprising:a converter circuit including a first antenna having a resonance circuit for receiving said transmitted radio wave and a rectifier circuit which converts an induced power received in said antenna into a DC voltage in rectifying it, the DC voltage being supplied to an internal circuit, a detector circuit portion for detecting one of the induced power obtained from said first antenna of the converter circuit and a voltage corresponding to said induced power, and a transmitting unit which transmits an information by a radio wave to the reader and/or writer device, the information concerning one of the induced power and the voltage detected by said detector circuit portion, said reader and/or writer device comprising: a receiving unit which receives said information by the radio wave being transmitted from the transmitting unit of the IC card, a control power supply circuit which controls an output of high frequency power based on the information received by the receiving unit, and a power transmitting unit having a second antenna for transmitting the output of high frequency power by the radio wave, the output of high frequency power being controlled by said control power supply circuit, wherein said system provides an arrangement so that information communication can be performed by the radio wave between an information communication portion of said reader and/or writer device and said internal circuit of the IC card.