Matsushita Electric Industrial Co., Ltd.

Keiichi Iiyama

Nobuyoshi Asaka

Hideo Ohara

Makoto Uchida

Yasushi Sugawara

Masayuki Arai

Nobuo Eda

Yutaka Harada

Yuko Fukuoka

Takuya Oka

Shinji Murakami

Seiki Yokozeki

Takashi Noda

Masaru Tanichi

Itsuo Takamiya

Akihisa Yamazaki

The reader/writer of this invention includes a high voltage withstanding amplifier, plural resonance circuits and plural high voltage withstanding analog switching circuits. The high voltage withstanding amplifier amplifies an analog signal to be sent to the outside. Each of the resonance circuits sends the analog signal amplified by the high voltage withstanding amplifier to the outside. The high voltage withstanding analog switching circuits are provided between the high voltage withstanding amplifier and the resonance circuits correspondingly to the resonance circuits. Each of the high voltage withstanding analog switching circuits electrically connects/disconnects the high voltage withstanding amplifier to/from the corresponding resonance circuit. Since the reader/writer includes the high voltage withstanding analog switching circuits, there is no need to provide high voltage withstanding amplifiers at the previous stages of the resonance circuits as in a conventional reader/writer. Accordingly, as compared with the conventional reader/writer in which the high voltage withstanding amplifiers are provided correspondingly to the respective resonance circuits, the number of high voltage withstanding amplifiers (the number of components) can be reduced.

Reader/writer and analog switching circuit

An electronic circuit module formed of an antenna coil and an integrated circuit provided on a circuit board is provided inside a hollow resin case formed of a first part and a second part. A first slit leading into the hollow portion is provided in one side face of the resin case formed of the first and second parts joined to each other. Since the electronic circuit module is not exposed to high temperatures and high pressure during the manufacturing process, defects such as the breakage of the integrated circuit or the disconnection of the antenna coil can be avoided. Since the slit leading into the hollow portion is provided, the hollow portion does not swell by the temperature increase. In addition, pinholes do not tend to be formed during the joining of the first and second parts. Thus, a contactless data carrier with an excellent electrostatic withstand voltage characteristic can be provided.

Contactless data carrier

A non-contact data carrier includes a battery, an electric-supply circuit for rectifying a received carrier signal and generating power, and an electric-supply switching circuit for comparing the voltage of the battery and the voltage generated by the electric-supply circuit and selecting either one of the voltages. When the battery can supply power, long-distance communication can be performed by supplying power from the battery. In case of battery exhaustion, power is supplied from the electric-supply circuit which receives a stronger carrier signal by using the non-contact IC card in the proximity of a question unit and rectifies the carrier signal, so that the function of the non-contact data carrier is maintained.

Non-contact data carrier system

A fuel cell device, wherein, after an output voltage from a main body of a fuel cell is converted using a converter, the relation between the resultant predetermined output voltage V,and an output voltage V,from a secondary battery is so set as to satisfy V,>V,. When, at the time of a sudden change of an external load, the output voltage V from the main body of the fuel cell becomes lower than a predetermined voltage V,, an output to a charge controlling unit is stopped. When the output voltage V from the main body of the fuel cell is lowered even further and becomes lower than a predetermined voltage V,, an output to an auxiliary device, which is necessary for driving the fuel cell device, is switched from the output from the converter to the output from the secondary battery.

Fuel cell device

A data transmission and reception system according to this invention comprises a transmitter for transmitting data by modulating transmit data and a receiver for receiving and demodulating a signal from the receiver, wherein the receiver includes a parallel resonator for receiving a PSK signal; a full rectification circuit for detecting output from the parallel resonator; a low pass filter for shaping the waveform of output from the full rectification circuit; and a comparator for converting output from the low pass filter into a binary-coded signal so that demodulated signals can be obtained from the output of the comparator. Therefore, PSK signals can be demodulated without a PLL or a tank circuit, the overall system consumes a smaller amount of power and is thin and reliable, the transmitter has an amplifier that can operate efficiently, particularly with a limited power supply as in IC cards or a single power supply used for portable terminals, and the receiver is reliable even with a simple circuit using a communication method that locally suppresses the amplitude at phase change points to remove an oscillation circuit in order to reduce the size and thickness of the device.

Data transmission and reception system

Growing community of inventors

Neyagawa, Japan

Keiichi Iiyama