Power transmission system, ic card and information communicating system using ic card

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical Fields Targeted by the Invention]

The present invention is a power transmission system that transmits power from a power transmission device to an IC card using electromagnetic waves, and converts the transmitted induced power into a DC voltage to convert the transmitted induced power into the transmitted induced power or the induced power. It is characterized by having an IC card that detects a corresponding voltage, controls the impedance based on the detected induced voltage or the voltage corresponding to the induced power, obtains a desired DC voltage, and supplies it to an internal circuit. It is a power transmission system, an IC card, and an information communication system using an IC card.

【0002】

[Conventional technology]

According to the present invention, a commuter ticket, a ticket, etc. used at a station ticket gate or a bus can be converted into an IC card, which can be passed or approached by a reader / writer provided at the station ticket gate or a bus without contact. On the other hand, the present invention relates to a power transmission system that transmits power wirelessly, an IC card, and an information communication system using an IC card.

【0003】

Conventionally, it has been known that power is supplied from the power supply side to the IC card in a non-contact manner using light or a magnetic field. By the way, commuter passes and tickets used at station ticket gates and buses are converted into IC cards, and users pass through these IC cards without contacting the readers / writers provided at station ticket gates and buses. When this is done, the distance between the IC card and the reader / writer will fluctuate significantly. When the distance between the IC card and the reader / writer is large When the reader / writer is set to transmit appropriate power to the IC card, the distance between the IC card and the reader / writer is close. At times, excessive power is transmitted from the reader / writer to the IC card, causing the IC card to malfunction or even be damaged. That is, in the above-mentioned prior art, even if the distance between the IC card and the reader / writer fluctuates significantly, the point that power is stably transmitted from the reader / writer to the IC card is not considered. It was. However, as a conventional technique for stably transmitting electric power from the reader / writer to the IC card even if the distance between the IC card and the reader / writer fluctuates significantly, JP-A-7-85233 There are Japanese Patent Application Laid-Open No. 9-62816 and Japanese Patent Application Laid-Open No. 9-62816.

【0004】

Japanese Patent Application Laid-Open No. 7-85233 describes a non-contact electromagnetic coupling type data carrier having a function of receiving data including a control signal from a fixed facility, and a rectifier D1 in parallel with the receiving coil of the data carrier. The rectifier circuit consisting of the capacitor C2 and the transistor T2 controlled by the DC power supply voltage obtained from the rectifier circuit, and the variable resistance element consisting of the resistor R3 and the resistor R4 are connected, and excessive power is consumed by this variable resistor element. It is stated that it should be done. Further, Japanese Patent Application Laid-Open No. 7-85233 describes the rectifier D2, the resistor R1 and the capacitor for detecting the amplitude modulation data superimposed on the AC voltage induced in the receiving coil and transmitting it as an input signal to the data carrier main circuit. A signal detection circuit consisting of C3, and amplitude modulation consisting of a transistor T1 that receives an output signal from the data carrier main circuit, switches the transistor T1, and transmits data from the data carrier to a fixed facility, a capacitor C4, and a resistor R2. It is described that the circuit is connected in parallel to the receiving coil of the data carrier. In this conventional technique, since the resonance circuit is not incorporated in the receiving coil of the data carrier, when the distance between the transmitting coil on the fixed side and the receiving coil on the data carrier side becomes large and significantly separated, the receiving coil Will not induce a large induced voltage and will not be able to transmit the power required by the data carrier main circuit. Further, in this conventional technique, since it is half-wave rectification, there is a problem that the ripple is large and the smoothing capacitance is large, and as a result, it becomes difficult to reduce the size of the capacitor and incorporate it.

【0005】

Further, in JP-A-9-62816, the received signal level of the antenna resonance circuit for data transmission / reception is detected by, and the quality factor Q of the antenna resonance circuit is changed by the variable resistance element according to the detected level and input. It is described that the received signal level is adjusted to a preferable value.

【0006】

[Problems to be Solved by the Invention]

In any of these conventional techniques, since the variable resistance element is directly connected to the receiving antenna in parallel, there is a problem that the temperature rise of the variable resistance element becomes large and the element size of the withstand voltage protection circuit becomes large.

【0007】

An object of the present invention is to make an IC card from the reader / writer wirelessly to the internal circuit of the IC card even if the distance between the IC card and the reader / writer fluctuates significantly in order to solve the above problems. An object of the present invention is to provide a wireless power transmission system and an IC card in which the element size of the withstand voltage protection circuit provided is reduced and the temperature rise of the variable impedance circuit is reduced so that power can be stably supplied. Another object of the present invention is to simply pass or bring the IC card non-contact to the reader and / or the writer, and wirelessly from the reader and / or the writer to the internal circuit of the IC card. A wireless power transmission system and IC card that reduces the element size of the withstand voltage protection circuit provided in the circuit and reduces the temperature rise of the variable impedance circuit to improve the responsiveness of power and enable stable power supply. Is to provide. Another object of the present invention is to stably supply electric power from a reader and / or a writer to an IC card in a non-contact manner, and to reduce and change the element size of a withstand voltage protection circuit provided in the IC card. To provide an information communication system using an IC card that reduces the temperature rise of an impedance circuit and supplies it to an internal circuit so that information can be communicated with high reliability between a reader and / or a writer and an IC card. There is.

【0008】

Another object of the present invention is to control the capacitance with respect to the induced power received on the IC card side even if the distance between the IC card and the reader / writer fluctuates significantly. An object of the present invention is to provide a wireless power transmission system capable of stably supplying electric power by reducing a temperature rise of an impedance circuit, an IC card, and an information communication system using an IC card. Another object of the present invention is to simply pass or bring the IC card non-contactly to the reader and / or the writer, and to wirelessly transfer appropriate power from the power transmitter of the reader and / or the writer to the IC card. A wireless power transmission system and IC that stably supplies information to the internal circuit of the IC card and enables highly reliable communication of information between the reader and / or writer and the IC card. The purpose is to provide an information communication system using a card and an IC card.

【0009】

[Means for solving problems]

The present invention is a power transmission system for transmitting power from a power transmission device (reader and / or writer device) to an IC card using electromagnetic waves in order to achieve the above object, and the IC card is transmitted. An antenna having a resonance circuit that receives the electromagnetic waves, a full-wave rectifying circuit that full-wave rectifies the induced power received by the antenna, and a DC voltage that is full-wave rectified by the full-wave rectifying circuit into a power supply voltage consisting of a DC voltage. The power supply circuit to be converted, the detection circuit that detects the DC voltage that has been full-wave rectified by the full-wave rectifier circuit, and the power supply that has been converted by the power supply circuit so that the DC voltage detected by the detection circuit becomes a desired DC voltage. Power transmission characterized by having an impedance control circuit unit that controls an impedance with respect to a voltage to obtain a desired power supply voltage and an internal circuit that receives a supply of a desired power supply voltage obtained from the impedance control circuit unit. It is a system. Further, the present invention is a power transmission system for transmitting power from a power transmission device to an IC card using an electromagnetic wave, wherein the IC card has a receiving unit that receives induced power by the transmitted electromagnetic wave and the receiving unit. A rectifying circuit unit that rectifies the induced power received in the above and converts it into a DC voltage, a detection circuit unit that detects the induced power obtained from the receiving unit or a voltage corresponding to the induced power, and a detection circuit unit that detects the induced power. A variable impedance control circuit unit that controls the impedance of the DC voltage obtained from the rectifying circuit unit based on the induced power or a voltage corresponding to the induced power, and a DC voltage supply controlled from the variable impedance control circuit unit. It is a power transmission system characterized by having an internal circuit that receives it.

【0010】

Further, the present invention is a power transmission system for transmitting power from a power transmission device to an IC card using electromagnetic waves, in which the transmitted induced power is converted into a DC voltage, and the transmitted induced power or the induced power is used. An IC that detects a voltage corresponding to power and controls the capacitance based on the detected induced voltage or the voltage corresponding to the induced power to obtain a power supply voltage consisting of a desired DC voltage and supply it to an internal circuit. It is a power transmission system characterized by having a card. Further, the present invention is a power transmission system for transmitting power from a power transmission device to an IC card using electromagnetic waves, and is obtained from a rectifier circuit that converts the transmitted induced power into a DC voltage and the rectifier circuit. Based on an internal circuit that receives a DC voltage, a detection circuit that detects the transmitted induced power or a voltage corresponding to the induced power, and an induced voltage detected by the detection circuit or a voltage corresponding to the induced power. The power transmission system is provided with an IC card having a capacitance control circuit that controls the capacitance to obtain a power supply voltage composed of a desired DC voltage and supplies the power supply voltage to the internal circuit.

【0011】

Further, the present invention is a power transmission system that transmits power from a power transmission device to an IC card using electromagnetic waves, converts the transmitted induced power into a DC voltage, supplies the power to an internal circuit, and transmits the power. It has an IC card that detects the induced power or the voltage corresponding to the induced power and transmits the information about the detected induced power or the voltage corresponding to the induced power to the power transmission device using electromagnetic waves. It is a power transmission system characterized in that the power transmitted from the power transmission device is controlled based on the transmitted information. Further, the present invention is a power transmission system that transmits power from a power transmission device to an IC card using electromagnetic waves, and has an IC card that converts the transmitted induced power into a DC voltage and supplies it to an internal circuit. Then, the electric power according to the relative position between the IC card and the electric power transmitting device is detected, and the electric power transmitted from the electric power transmitting device is controlled based on the detected information. It is a transmission system.

【0012】

Further, the present invention is a power transmission system for transmitting power from a power transmission device to an IC card using electromagnetic waves, and has an IC card that converts the transmitted induced power into a DC voltage and supplies it to an internal circuit. Then, information according to the relative position between the IC card and the power transmission device is detected, and the impedance of the IC card is controlled based on the detected information to obtain a desired DC voltage. It is a power transmission system.

【0013】

Further, in the present invention, an antenna having a resonance circuit for receiving the transmitted electromagnetic wave, a full-wave rectification circuit for full-wave rectifying the induced power received by the antenna, and a full-wave rectification circuit for full-wave rectification are performed. A power supply circuit that converts a DC voltage into a power supply voltage composed of a DC voltage, a detection circuit that detects a DC voltage that has been fully wave rectified by the full wave rectifier circuit, and a DC voltage that is a desired DC voltage detected by the detection circuit. The impedance control circuit unit that controls the impedance with respect to the power supply voltage converted by the power supply circuit to obtain a desired power supply voltage and the desired power supply voltage obtained from the impedance control circuit unit are supplied. It is an IC card characterized by having an internal circuit. Further, the present invention includes a receiving unit that receives induced power by an electromagnetic wave, a rectifying circuit unit that rectifies the induced power received by the receiving unit and converts it into a DC voltage, and an induced power or the induced power obtained from the receiving unit. Variable impedance control that controls the impedance of the detection circuit unit that detects the voltage according to the voltage, and the DC voltage obtained from the rectifier circuit unit based on the induced power detected by the detection circuit unit or the voltage corresponding to the induced power. The IC card is characterized by having a circuit unit and an internal circuit that receives a DC voltage supplied from the variable impedance control circuit unit. Further, the present invention is characterized in that, in the IC card, the impedance in the variable impedance control circuit unit is formed by a resistor. Further, the present invention is characterized in that, in the IC card, the full-wave rectifier circuit, the power supply circuit, the detection circuit, the impedance control circuit, and the internal circuit are configured by one chip.

【0014】

Further, the present invention includes a receiving unit that receives induced power by an electromagnetic wave, a rectifying circuit unit that rectifies the induced power received by the receiving unit and converts it into a DC voltage, and an induced power or the induced power obtained from the receiving unit. The capacitance is controlled based on the detection circuit unit that detects the voltage corresponding to the voltage, and the induced power detected by the detection circuit unit or the voltage corresponding to the induced power, and the desired DC voltage is obtained from the rectifying circuit unit. The IC card is characterized by having a capacitance control circuit unit to be obtained and an internal circuit controlled by the capacitance control circuit unit and receiving a DC voltage from the rectifier circuit unit. The present invention also includes a reader and / or a writer device (unit) that has an information communication unit and a power transmission unit, and transmits power from the power transmission unit to an IC card using electromagnetic waves, and the reader. A rectifying circuit unit that rectifies the induced power transmitted from the lighter device and converts it into a DC voltage, a detection circuit unit that detects the induced power obtained from the receiving unit or a voltage corresponding to the induced power, and the like. A variable impedance control circuit unit that controls the impedance of the induced power detected by the detection circuit unit or a DC voltage obtained from the rectifying circuit unit based on the induced power or a voltage corresponding to the induced power, and a desired variable impedance control circuit unit from the variable impedance control circuit unit. It has the IC card that obtains a DC voltage and supplies it to the internal circuit, and communicates information using electromagnetic waves between the internal circuit of the IC card and the information communication unit of the reader and / or writer device. It is an information communication system using an IC card, which is characterized by being configured.

【0015】

Further, the present invention includes an information communication unit and a power transmission unit, and includes a reader and / or a writer device (unit) for transmitting power from the power transmission unit to an IC card using electromagnetic waves. The card is an antenna having a resonance circuit that receives electromagnetic waves transmitted from the reader and / or writer device, a full-wave rectifier circuit that full-wave rectifies the induced power received by the antenna, and a full-wave rectifier circuit. A power supply circuit that converts the rectified DC voltage into a power supply voltage consisting of a DC voltage, a detection circuit that detects the full-wave rectified DC voltage by the full-wave rectifier circuit, and a desired DC voltage detected by the detection circuit. An impedance control circuit that controls the impedance with respect to the power supply voltage converted by the power supply circuit so as to become a voltage to obtain a desired power supply voltage, and an internal circuit that receives the supply of the desired power supply voltage obtained from the impedance control circuit. An IC card is used, which is configured to communicate information using electromagnetic waves between the internal circuit of the IC card and the information communication unit of the reader and / or writer device. It is an information communication system.

【0016】

The present invention also includes a reader and / or writer device that has an information communication unit and a power transmission unit, and transmits power from the power transmission unit to an IC card using electromagnetic waves. The induced power transmitted from the reader and / or the writer device is converted into a DC voltage and supplied to the internal circuit, and the induced power transmitted to the IC card or the voltage corresponding to the induced power is detected and detected. It has the IC card that transmits information about the induced power or the voltage corresponding to the induced power to the power transmission unit of the reader and / or the writer device using electromagnetic waves, and the reader and / or the writer device has the IC. It is configured to control the power transmitted from the power transmission unit based on the information transmitted from the card, and electromagnetic waves are transmitted between the internal circuit of the IC card and the information communication unit of the reader and / or writer device. It is an information communication system using an IC card, which is characterized in that it is configured to communicate information by using it. Further, according to the present invention, in an information communication system using the IC card, power transmission using electromagnetic waves from the reader and / or writer device to the IC card, an internal circuit of the IC card, the reader and / or Information communication using electromagnetic waves with the information communication unit of the writer device is configured to be performed using a common antenna provided in each of the reader and / or the writer device and the IC card. It is a feature.

【0017】

Further, according to the present invention, in the information communication system using the IC card, the reader and / or writer device encodes a power supply unit that generates a signal for power transmission and input data for transmission. A circuit, a modulator that amplitude-modulates and superimposes a signal obtained from a coding circuit on a signal obtained from the power supply unit, a feeding circuit that supplies power based on the signal obtained from the modulator, and the feeding circuit. It is characterized by having an antenna that generates the electromagnetic wave according to the current fed by.

【0018】

Further, the present invention relates to a decoding circuit that shapes and decodes a communication modulated wave detected by the antenna as the internal circuit in the IC card in an information communication system using the IC card. A microcomputer that inputs received data decoded by a decoding circuit and outputs transmission data, a coding circuit that encodes transmission data output from the microcomputer, and a signal encoded by the coding circuit. It is characterized by having a modulator which is modulated based on the above and is input to the antenna.

【0019】

As described above, according to the above configuration, even if the distance between the IC card and the reader / writer (power transmitter) fluctuates significantly, the IC is wirelessly transmitted from the reader / writer to the internal circuit of the IC card. It is possible to realize a wireless power transmission system and an IC card in which the element size of the withstand voltage protection circuit provided on the card is reduced and the temperature rise of the variable impedance circuit is reduced so that power can be stably supplied. .. In particular, since the element size of the withstand voltage protection circuit can be reduced and the temperature rise of the variable impedance circuit can be reduced, it can be configured as an IC card by mounting an antenna that receives electromagnetic waves and an element of one chip, which is inexpensive. IC card can be realized. Further, according to the above configuration, the IC card is simply passed or brought close to the reader and / or the writer in a non-contact manner by transmitting electric power by electromagnetic waves using a coiled or spiral antenna coil. Reader and / or By wirelessly from the writer, the element size of the withstand voltage protection circuit provided in the IC card is reduced with respect to the internal circuit of the IC card, and the temperature rise of the variable impedance circuit is reduced to improve the responsiveness of the power and stabilize the power. It is possible to realize a wireless power transmission system and an IC card that can supply power. Further, according to the above configuration, even if the distance between the IC card and the reader / writer fluctuates significantly, the variable impedance circuit is controlled by controlling the capacitance with respect to the induced power received on the IC card side. It is possible to realize a wireless power transmission system and an IC card and an information communication system using an IC card that reduce the temperature rise of the electric power and enable a stable supply of electric power.

【0020】

Further, according to the above configuration, an appropriate power is wirelessly transmitted to the IC card from the power transmitter of the reader and / or the writer simply by passing or bringing the IC card in contact with the reader and / or the writer in a non-contact manner. A wireless power transmission system and IC card that transmits information in a stable manner to the internal circuit of the IC card and enables highly reliable communication of information between the reader and / or writer and the IC card. In addition, an information communication system using an IC card can be realized. Further, according to the above configuration, the reader and / or the writer device stably supplies power to the IC card in a non-contact manner, and the reader and / or the writer device and the IC card communicate information with high reliability. It is possible to realize an information communication system using an IC card that enables (transmission and reception).

【0021】

BEST MODE FOR CARRYING OUT THE INVENTION

The wireless power transmission method and the embodiment of the IC card according to the present invention will be described with reference to the drawings. FIG. 1 shows an outline of a power transmission method for wirelessly transmitting power to an IC card 2 that passes or is in contact with a reader and / or a writer 1 provided at a ticket gate or a bus of a station according to the present invention. It is a figure which shows the structure. The IC card 2 is held by the user and passed wirelessly by passing it at a distance of about 5 to 20 cm without contact with the reader and / or writer 1 provided at the ticket gate of the station or the bus. It serves as a ticket, commuter pass, etc. by transmitting and receiving information such as a ticket and a commuter pass.

【0022】

FIG. 2 is a diagram showing a wireless power transmission method according to the present invention. Reference numeral 21 denotes a power supply circuit provided in the reader and / or writer 1 provided in the ticket gate of the station or the bus. This power supply circuit 21 has a power supply 22 that generates a high frequency voltage of 13.56 MHz, a matching circuit 23 for matching impedance to prevent reflection, and an electromagnetic wave (wireless) of about 2 to 5 W of power at 13.56 MHz. It is composed of a coil 24 for transmission in. The IC card 2 has a coil 26 that receives power by electromagnetic waves (radio) from the power supply circuit 21 provided in the reader and / or writer 1, and converts the high-frequency power received by the coil 26 into a DC voltage of about 7 to 15 V. An induced voltage generating unit 28 including a rectifying circuit 27 and an internal circuit (for example, composed of an IC chip) 29 that operates by receiving a DC voltage of about 7 to 10 V generated from the induced voltage generating unit 28. And have. Even if the distance between the IC card 2 and the reader and / or writer 1 is significantly large, the coil 26 has a tuning capacity of 25 so that a desired DC voltage can be supplied to the internal circuit 29. A resonance circuit is provided so that a large induced power can be obtained by connecting the above. As the coil 26, a spiral-shaped antenna coil is continuously wound in the same direction to form a multi-layer structure of two or more layers, so that a parallel resonant circuit is formed by the stray capacitance generated between the coils and the inductance of the coil, and is tuned. The required capacitance 25 can be unnecessary or significantly reduced.

【0023】

In addition, the use of a coil (coil-shaped or spiral-shaped antenna) 24 and a coil (coil-shaped or spiral-shaped antenna) 26 to transmit power by electromagnetic waves (radio) takes less than 0.1 sec for power transmission. This is to improve the responsiveness so that power can be supplied to the internal circuit (for example, the IC chip) 29 of the IC card 2. Further, when the coil 26 is formed on the IC card 2, there is a strong advantage against the deformation of the IC card 2. Therefore, if power can be supplied to the internal circuit 29 of the IC card 2 in 0.1 sec or less, it is possible to use a light emitting element, a light receiving element, or the like instead of the coils 24 and 26. FIG. 3 shows the relationship between the distance d between the coil 24 of the power supply circuit 21 provided in the reader / writer 1 and the IC card 25 and the induced voltage VL obtained from the rectifier circuit 27. As shown in Fig. 3, when the distance d between the coil 24 of the power supply circuit 21 and the IC card 25 is about 20 cm at the maximum, the induced voltage VL is the minimum allowable voltage Vmin. When the circuit is designed so that 2 to 4V can be obtained, when the distance between the coil 24 of the power supply circuit 21 and the IC card 25 becomes the minimum d1 5cm, the induced voltage VL is the maximum allowable voltage Vmax It greatly exceeds 5 to 15V and becomes about 40V, which causes malfunction or damage in the internal circuit 29. Therefore, in the present invention, the induced voltage VL obtained from the rectifier circuit 27 is always within the allowable induced voltage range Vmin ~, even if the reader / writer 1 is passed at a distance of about 5 to 20 cm without contact. It is to control so that it is within Vmax.

【0024】

Next, the first embodiment of the wireless power transmission control method according to the present invention will be described with reference to FIG. FIG. 4 is a diagram showing a schematic configuration of a first embodiment of a wireless power transmission control method according to the present invention. The power supply circuit 21 provided in the reader and / or the writer 1 is similar to the configuration shown in FIG. The induced voltage generator 28a in the IC card 2 applies the high-frequency power controlled by varying the impedance to the high-frequency power obtained from the coil 26 to the coil 26 and the rectifying circuit 27, which is also shown in FIG. 2, to the rectifying circuit 27. Induced voltage VL obtained from the variable impedance circuit 30 to be supplied and the rectifier circuit 27 A voltage detection circuit 31 for detecting the above voltage detection circuit 31 and a control circuit 32 for controlling the impedance of the variable impedance circuit 30 to be variable based on the induced voltage value detected by the voltage detection circuit 31 are added. The internal circuit 29 in the IC card 2 is the same as in FIG. As shown by the chain line, the voltage detection circuit 31 may detect the high frequency power (high frequency voltage) obtained from the variable impedance circuit 30 and calculate, for example, the average induced voltage. With this configuration, when the voltage detection circuit 31 detects the induced voltage VL obtained from the rectifying circuit 27 and detects that it deviates from the allowable induced voltage value range Vmin to Vmax, the control circuit 32 controls the variable impedance circuit 30. The impedance is controlled, the high frequency power obtained from the coil 26 is controlled and supplied to the rectifying circuit 27, and the voltage within the allowable induced voltage value can always be obtained from the rectifying circuit 27. As a result, even if the distance between the reader / writer 1 and the IC card 2 is as close as 5 cm, a voltage within the allowable induced voltage value can be supplied to the internal circuit 29. The rectifier circuit 27 and the internal circuit 29 may be configured by one IC chip.

【0025】

Next, a second embodiment of the wireless power transmission control method according to the present invention will be described with reference to FIG. FIG. 5 is a diagram showing a schematic configuration of a second embodiment of the wireless power transmission control method according to the present invention. The second embodiment shown in FIG. 5 differs from the first embodiment shown in FIG. 4 in that the variable impedance circuit 30 is provided after the rectifier circuit 27. The power supply circuit 21 provided in the reader and / or the writer 1 is similar to the configuration shown in FIG. The induced voltage generator 28a in the IC card 2 includes a rectifier circuit 27 that converts high-frequency power obtained from the coil 26 into an induced DC voltage, and an induced voltage VL obtained from the rectifier circuit 27. The impedance is variably controlled with respect to the DC voltage output from the rectifier circuit 27 based on the voltage detection circuit 31 that detects the voltage and the induced voltage value detected by the voltage detection circuit 31, and the DC voltage is supplied to the internal circuit 29. The variable impedance circuit 30 is provided with a control circuit 32 for controlling the impedance of the variable impedance circuit 30 so as to be variable. The internal circuit 29 in the IC card 2 is the same as in FIG. With this configuration, when the voltage detection circuit 31 detects the induced voltage VL obtained from the rectifying circuit 27 and detects that it deviates from the allowable induced voltage value range Vmin to Vmax, the control circuit 32 controls the variable impedance circuit 30. The impedance is controlled, the DC voltage obtained from the rectifying circuit 27 is controlled and supplied to the internal circuit 29, and the voltage within the allowable induced voltage value can always be obtained from the rectifying circuit 27. As a result, even if the distance between the reader and / or the writer 1 and the IC card 2 is as close as 5 cm, a voltage within the allowable induced voltage value can be supplied to the internal circuit 29.

【0026】

FIG. 6 is a diagram showing a specific first embodiment of the variable impedance circuit 30 shown in FIG. That is, the variable impedance circuit 30 is configured by connecting the resistor R1 and the electronic switch S1 connected in series to both ends of the coil 26, and the resistor R2 and the electronic switch S2 in parallel, and these electronic switches S1 and S2 are connected. It is configured to be turned on / off by a control signal from the control circuit 32. With such a configuration, as shown in FIG. 7, when the distance between the coil 24 of the power supply circuit 21 and the coil 26 of the IC card 2 is large d2, the control circuit first approaches when the induced voltage VL exceeds Vmax. By turning on the electronic switch S1 with the electronic switch S2 turned off by the control signal from 32, the resistor R1 is connected and the induced voltage VL drops to Vmin, and the coil 24 of the power supply circuit 21 and the coil of the IC card 2 When the distance from 26 approaches and the induced voltage VL exceeds Vmax, the resistance R1 and resistance R2 are first generated by turning on the electronic switch S2 with the electronic switch S1 turned on by the control signal from the control circuit 32. Connected and induced voltage VL is Vmin Furthermore, it is possible to prevent the induced voltage VL from exceeding Vmax even if the distance between the coil 24 of the power supply circuit 21 and the coil 26 of the IC card 2 becomes close to d1. By further increasing the number of resistors, the tolerance between Vmin and Vmax can be narrowed. When the variable impedance circuit 30 is configured by connecting the resistor R1 and the electronic switch S1 connected in series to both ends of the coil 26 and the resistor R2 and the electronic switch S2 in parallel in this way, it is extremely responsive. Excellent in terms of points.

【0027】

The variable impedance circuit 30 described above can be applied to the variable impedance circuit 30 including the variable resistance element shown in FIG. In particular, as shown in FIG. 14, the element size of the withstand voltage protection circuit 30 is increased by providing a variable impedance circuit 30 composed of a variable resistance element after the constant voltage power supply circuit 204 provided after the rectifier circuit 27 (203). It can be made smaller, and as a result, the wireless chip 202 can be made smaller, and the cost of the IC card as well as the chip can be reduced. FIG. 8A is a diagram showing a specific second embodiment of the variable impedance circuit 30 shown in FIG. That is, the variable impedance circuit 30 is configured by connecting the capacitor C1 and the electronic switch S1 connected in series to both ends of the coil 26, and the capacitor C2 and the electronic switch S2 in parallel, and these electronic switches S1 and S2 are connected. It is configured to be turned on / off by a control signal from the control circuit 32. Even with such a configuration, as in the first embodiment shown in FIG. 5, even if the distance between the coil 24 of the power supply circuit 21 and the coil 26 of the IC card 2 becomes close, FIG. 7 (b) shows. From the relationship shown, the induced voltage VL obtained from the rectifier circuit 27 The range of can be controlled to the allowable voltage range Vmin ~ Vmax. According to this second embodiment, it is possible to reduce the temperature rise as compared with the first embodiment, and it is excellent in terms of reliability. However, in order to carry out the second embodiment, a technique for manufacturing a small element having a variable capacitance is required.

【0028】

FIG. 9 is a diagram showing a specific third embodiment of the variable impedance circuit 30 shown in FIG. That is, the variable impedance circuit 30 is formed by terminals T1, T2, T3 according to the length of the coil 26, and is switched to these terminals T1, T2, T3 by the control signal from the control circuit 32 by the electronic switch St. It is configured. Even with such a configuration, the high-frequency power induced in the coil 26 can be changed, and as a result, even if the distance between the coil 24 of the power supply circuit 21 and the coil 26 of the IC card 2 becomes closer, the rectifier circuit 27 Obtained induced voltage VL The range of can be controlled to the allowable voltage range. Next, a third embodiment of the wireless power transmission control method according to the present invention will be described with reference to FIG. FIG. 10 is a diagram showing a schematic configuration of a third embodiment of the wireless power transmission control method according to the present invention. The power supply circuit 21a provided in the reader and / or writer 1 includes a control power supply 22a that generates a variable voltage with a high frequency of 13.56 MHz, a matching circuit 23 for matching impedance, and about 2 to 5 W at 13.56 MHz. Coil 24 for transmitting power by electromagnetic waves (radio), coil (coil-shaped or spiral-shaped antenna) 37 and receiving circuit 38 that receive the signal of the induced voltage value detected from IC card 2 by electromagnetic waves (radio) And a control circuit 39 that controls the high frequency voltage of the control power supply 22a to be variable based on the induced voltage value received by the reception circuit 38. The induced voltage generator 28b in the IC card 2 has the coil 26 and the rectifier circuit 27, which are also shown in FIG. 2, and the induced voltage VL obtained from the rectifier circuit 27. The voltage detection circuit 31 for detecting the above, and the transmission circuit 35 and the coil (coil or spiral) for transmitting the signal of the induced voltage value detected by the voltage detection circuit 31 to the coil 37 of the power supply circuit 21a by electromagnetic waves (wireless). The shape of the antenna) 36 was added. The internal circuit 29 in the IC card 2 is the same as in FIG.

【0029】

With this configuration, the voltage detection circuit 31 detects the induced voltage VL obtained from the rectifier circuit 27, and the signal of the detected induced voltage value is supplied by the transmission circuit 35 and the coil 36 by electromagnetic waves (radio). It is transmitted to the coil 37 of the circuit 21a and received by the receiving circuit 38, and the control circuit 39 is in the range of the allowable induced voltage value Vmin to Vmax based on the signal of the induced voltage value received by the receiving circuit 38. The high frequency voltage of the control power supply 22a is controlled by detecting the deviation from the control power supply 22a, the high frequency power transmitted from the coil 24 to the coil 26 is controlled and supplied to the rectifying circuit 27, and the rectifying circuit 27 always has a range of allowable induced voltage values. The voltage inside can be obtained. As a result, even if the distance between the reader and / or the writer 1 and the IC card 2 is as close as 5 cm, a voltage within the allowable induced voltage value can be supplied to the internal circuit 29. Next, a fourth embodiment of the wireless power transmission control method according to the present invention will be described with reference to FIG. FIG. 11 is a diagram showing a schematic configuration of a fifth embodiment of the wireless power transmission control method according to the present invention. The power supply circuit 21b provided in the reader and / or writer 1 includes a control power supply 22a that generates a variable voltage with a high frequency of 13.56 MHz, a matching circuit 23 for matching impedance, and about 2 to 5 W at 13.56 MHz. A sensor circuit 41 that detects the instantaneous distance between the coil 24 for transmitting power by electromagnetic waves (radio) and the passing IC card 2 using infrared rays or ultrasonic waves, and a signal obtained from the sensor circuit 41. Based on the information of the instantaneous distance (position) d between the position detection circuit 42 that calculates the instantaneous distance (position) with the passing IC card 2 and the passing IC card 2 detected by the position detection circuit 42. It is composed of a control circuit 39 that controls the high frequency voltage of the control power supply 22a so as to be variable. The induced voltage generating unit 28 in the IC card 2 is composed of the coil 26 and the rectifier circuit 27, which are also shown in FIG.

【0030】

With this configuration, the sensor circuit 41 detects the instantaneous distance to the passing IC card 2 using infrared rays, ultrasonic waves, or the like, and the position detection circuit 42 passes through the IC card 2 based on the detected signal. The instantaneous distance (position) with and from is calculated, and the control circuit 39 calculates the distance d and the induced voltage shown in FIG. 3 based on the information of the instantaneous distance (position) d with the IC card 2 calculated by the position detection circuit 42. VL The high frequency voltage value generated from the control power supply 22a is calculated from the relationship with the control power supply 22a, the calculated high frequency voltage value is controlled to be generated from the control power supply 22a, and the high frequency power transmitted from the coil 24 to the coil 26 is controlled. It is supplied to the rectifying circuit 27, and a voltage within the allowable induced voltage value can always be obtained from the rectifying circuit 27. As a result, even if the distance between the reader and / or the writer 1 and the IC card 2 is as close as 5 cm, a voltage within the allowable induced voltage value can be supplied to the internal circuit 29. Next, the whole will be described including the part that functions as a ticket, a commuter pass, etc. by transmitting and receiving information such as a ticket and a commuter pass using the radio according to the present invention. FIG. 12 shows a schematic configuration in the first embodiment for the whole including a part that functions as a ticket, a commuter pass, etc. by transmitting and receiving information such as a ticket and a commuter pass wirelessly. is there. That is, the reader and / or In addition to the power supply circuit 21, the writer 1 has an information transmission / reception unit 51 that transmits / receives information to / from the IC card 2 using electromagnetic waves (wireless). The information transmission / reception unit 51 is connected to a communication network and a mechanism or display means for opening / closing the ticket gate door, outputs information (data) to be transmitted to the IC card 2 to the modulation unit 54, and outputs information (data) to be transmitted to the IC card 2 to the modulation unit 54 and obtains information (information obtained from the demodulation unit 55). CPU 52 that processes and outputs data), memory 53 that stores information obtained from IC card 2 and processing program information, and a modulator that modulates at 3.39 MHz to transmit information from CPU 52 to IC card 2. 54, an amplifier 56 that amplifies the signal modulated by the modulation unit 54, a coil 59 that transmits and receives information by electromagnetic waves (radio) between the IC card 2, and an amplifier that amplifies the signal received by the coil 59. It is composed of 57, a demodulator 55 that demolishes the signal amplified by the amplifier 57 at 3.39 MHz, and a matching circuit 58 that matches the impedance.

【0031】

The IC card 2 also has an induced voltage generating unit 28 and an internal circuit 29, and the internal circuit 29 has a memory 63 for storing information such as a ticket and a commuter pass, and writes and reads to and from the memory 63. The CPU 62 that controls the above, the modulator 65 that modulates the information (data) read from the memory 63 at 3.39 MHz, the amplifier 67 that amplifies the signal from the modulator 65, and the coil of the information transmitter / receiver 51. A coil 69 that transmits and receives information to and from 59 by electromagnetic waves (radio), an amplifier 66 that amplifies the signal received by the coil 69, and a demodulator 64 that demolishes the signal amplified by the amplifier 66 at 3.39 MHz. , It is composed of a matching circuit 68 that matches the impedance. With such a configuration, power is wirelessly transmitted from the reader / writer 1 provided at the ticket gate of the station or the bus to the IC card 2 which passes or is approached in a non-contact manner, and the internal circuit 29 of the IC card 2 A stable DC voltage of 7 to 15V can be supplied to the computer, and the internal circuit 29 such as the CPU 62 can be operated stably. As a result, the IC card 2 is held by the user and installed at the ticket gate or bus of the station. Information such as tickets and commuter passes can be sent and received wirelessly by passing the reader / writer 1 at a distance of about 5 to 20 cm without contact, and the IC card 2 can be used as a ticket or a ticket. It can serve as a commuter pass, etc.

【0032】

FIG. 13 shows the IC card 2 with the coil 26 and the coil 69, and one or two circuit chips 70 in which the circuits 28, 27, 29, 31, and 32 connected to the coils 26 and 69 are collectively configured. Indicates the mounting state of. In the embodiment shown in FIG. 9, as shown in FIG. 9B, the number of turns of the coil 26 is increased to increase the coil length, and the terminals T1, T2, and T3 are output from the middle and input to the circuit chip 70. Just do it. FIG. 14 shows a schematic configuration of the entire second embodiment including a part that functions as a ticket, a commuter pass, etc. by transmitting and receiving information such as a ticket and a commuter pass wirelessly. is there. That is, in the second embodiment shown in FIG. 14, the R / W coil (coil-shaped or spiral-shaped R / W antenna) 101 and the IC card (proximity wireless card) 2 provided in the R / W unit 1 are formed. Both power transmission and communication transmission / reception using electromagnetic waves (wireless) consisting of the power transmission wave and data communication modulation wave shown in FIG. 15 to and from the card coil (coil-shaped or spiral-shaped card antenna) 201. It shows the case of performing. As described above, the power transmission wave and the signal wave in the ASK modulation method have different frequency components when viewed in the frequency domain, but the amplitude of the power transmission wave only changes according to the signal speed when viewed in the time domain. That is, the modulated wave obtained by multiplying the power transmission wave by the signal wave only seems to fluctuate up and down in the waveform amplitude of the power transmission wave in the time domain. When this is transmitted wirelessly, it is conceivable to transmit the power transmission wave and the signal wave by different antennas, but in the present invention, in order to simplify the non-contact card (proximity wireless card: IC card) 2. , The electric field strength was limited to within the radio wave method (500 μV / m at a distance of 3 m), and this modulated wave was transmitted by a single antenna (R / W coil) 101.

【0033】

That is, the R / W (reader or / and writer) unit 1 encodes a power supply 105 that generates a high frequency voltage of 13.56 MHz and an input transmission data (DATA) 106 that is transmitted to the proximity radio card 2. Amplitude Shift Keying with the coding circuit 107 and the signal encoded by the coding circuit 107 on the high frequency voltage of 13.56MHz generated from the power supply 105. A modulator 108 that superimposes (modulation), a transmission amplifier 109 that amplifies a signal ASK-modulated on a high frequency voltage of 13.56 MHz by the modulator 108, and an inductance coupling 103 of the signal amplified by the transmission amplifier 109. A matching circuit (feeding circuit) 102 that has a capacitor 104 to match the impedance and prevent reflection, and an electromagnetic wave to transmit power and data according to the output of the matching circuit 102. Is generated, and the R / W coil 101 that receives the data transmitted by the electromagnetic wave from the card coil 201 of the proximity radio card 2 and the signal received by the R / W coil 101 are matched by the matching circuit 102 and subjected to inductance coupling. A filter circuit 110 that removes noise components from the signal generated by 103, a receiving amplifier 111 that amplifies the signal obtained through the filter circuit 110, and a high 13.56 MHz obtained from the power supply 105 that a signal amplified by the receiving amplifier 111. It includes a demodulator 112 that demodulates using a voltage signal of frequency, and a decoding circuit 113 that decodes the signal demodulated by the demodulator 112 and outputs it as received data (DATA) 114.

【0034】

The proximity wireless card (non-contact card: IC card) 2 includes a card coil 201, a wireless chip 202, and a CPU + interface chip 210. By downsizing the wireless chip 202, the wireless chip 202 and the CPU + interface chip 210 can be configured by one chip. The card coil 201 receives electromagnetic waves generated for power transmission and data transmission from the R / W coil 101 of the R / W unit 1, and generates electromagnetic waves according to the load switching modulated transmission data. is there. The wireless chip 202 rectifies the 13.56 MHz power received by the card coil 201, and matches the transmitted / received signals with the matching / rectifying circuit 203, and the matching / rectifying circuit 203 rectified from the matching / rectifying circuit 203. The DC voltage VL obtained from the constant voltage power supply circuit 204 supplied as a constant DC voltage power supply 205 of about 2 to 5 V at about 5 mW from the voltage and the matching / rectifying circuit 203. A voltage detection circuit 31 that detects the voltage by comparing with the reference voltage, and a variable resistor made of a FET or the like with respect to the DC voltage output from the constant voltage power supply circuit 204 based on the DC voltage value detected by the voltage detection circuit 31. A variable impedance control circuit 30 composed of a variable resistance element composed of a FET or the like that variably controls the variable impedance composed of the elements and supplies the DC power supply voltage 205 to the IC chips 202, 210 (internal circuit 29), and the card coil 201. The clock extraction circuit 206 that extracts the clock from the received signal obtained from the LPF circuit 206, the LPF circuit 207 that removes the noise component from the received signal obtained from the card coil 201, and the waveform shaping circuit that shapes the waveform of the received signal obtained from the LPF circuit 207. It has 208 and a load switching modulation circuit 209 that loads-switch-modulates a transmission signal and supplies it to the matching / rectifying circuit 203 for matching and supplying it to the card coil 201.

【0035】

The CPU + interface chip 210 has a frequency dividing circuit 211 that divides the frequency based on the clock signal extracted by the clock extraction circuit 206 of the wireless chip 202 to generate a signal for operating the microcomputer 214, and a waveform shaping circuit 208 of the wireless chip 202. The decoding circuit 212 that decodes the signal obtained from the decoding circuit 212, and the reception data control circuit 213 that controls the decoding data (received data) obtained from the decoding circuit 212 and inputs it to the microcomputer 214, and the transmission data from the microcomputer 214. The transmission data control circuit 215 obtained by controlling, the coding circuit 216 that encodes the transmission data obtained by controlling from the transmission data control circuit 215 and inputs it to the load switching modulation circuit 209 of the wireless chip 202, and the card. It has a built-in memory for storing information and a microcomputer 214 such as H8 that processes transmitted / received data and transfers data to and from the memory, and has a stable power supply 205 from the constant voltage power supply circuit 204 of the wireless chip 202. It is configured to receive the supply of. The reason why the R / W coil 101 and the card coil 201 are used to transmit electric power by electromagnetic waves (wirelessly) is to improve the efficiency of electric power transmission in the vicinity. Further, when the coil 201 is formed on the proximity radio card 2, there is a strong advantage that the proximity radio card 2 is deformed. Further, both the R / W coil 101 and the card coil 201 may be formed by a spiral antenna. Also, even if the distance between the IC card 2 and the reader and / or writer 1 is significantly large, the internal circuit 210, The card coil 201 is provided with a resonance circuit so that a tuning capacitance 25 can be connected to obtain a large induced power so that a desired DC voltage can be supplied to 202 (29). As the card coil 201, a spiral resonant antenna coil is continuously wound in the same direction to form a multi-layer structure having two or more layers, so that a parallel resonant circuit is formed by the stray capacitance generated between the coils and the inductance of the coil. The tuning capacitance 25 can be unnecessary or significantly reduced. Further, by configuring the rectifier circuit 203 to perform full-wave rectification, the ripple is reduced, the smoothing capacitance is also reduced, the smoothing capacitor can be miniaturized and incorporated, and the wireless chip 202 is miniaturized. It becomes possible to do. Further, in particular, by providing the variable impedance circuit 30 composed of the variable resistance element after the constant voltage power supply circuit 204 provided after the rectifying circuit 203, the element size of the withstand voltage protection circuit 30 can be reduced, and as a result, the wireless chip 202 It is possible to reduce the cost as an IC card as well as a chip by making it smaller, and it is possible to obtain high reliability as a chip 220 by reducing the temperature rise of the variable impedance circuit 30 composed of a variable resistance element.

【0036】

As described above, in the proximity wireless card system, the reader / writer 1 and the non-contact card 2 are arranged by bringing the non-contact card (proximity wireless card: IC card) 2 close to the reader or / and the writer 1. Power is transmitted wirelessly between the two, and information is transmitted and received (communication) wirelessly. That is, in the proximity wireless card system, the power transmission wave or communication wave is radiated by the reader / writer coil or spiral antenna 101, and this electromagnetic wave is received and induced by the card side coil or spiral antenna 201 to form the card side circuit. It operates and detects signals.

【0037】

[Effect of the invention]

According to the invention, even if the distance between the IC card and the reader / writer fluctuates significantly, the element size of the withstand voltage protection circuit provided on the IC card with respect to the internal circuit of the IC card wirelessly from the reader / writer can be determined. It has the effect of realizing a wireless power transmission system and an IC card that can be made smaller and can supply power in a stable manner by reducing the temperature rise of the variable impedance circuit. In particular, since the element size of the withstand voltage protection circuit can be reduced and the temperature rise of the variable impedance circuit can be reduced, it can be configured as an IC card by mounting an antenna that receives electromagnetic waves and an element of one chip, which is inexpensive. IC card can be realized. Further, according to the present invention, the IC card is simply passed or brought close to the reader and / or the writer in a non-contact manner by transmitting power by electromagnetic waves using a coiled or spiral antenna coil. By wirelessly from a reader and / or a writer, the element size of the withstand voltage protection circuit provided in the IC card is reduced with respect to the internal circuit of the IC card, and the temperature rise of the variable impedance circuit is reduced to improve the responsiveness of power. It has the effect of realizing a wireless power transmission system and an IC card that can stably supply power.

【0038】

Further, according to the present invention, even if the distance between the IC card and the reader / writer fluctuates significantly, the variable impedance circuit is controlled by controlling the capacitance with respect to the induced power received on the IC card side. It has the effect of being able to realize a wireless power transmission system that reduces the temperature rise and enables a stable supply of electric power, as well as an IC card and an information communication system using an IC card. Further, according to the present invention, an appropriate power can be wirelessly transmitted to the IC card from the power transmitter of the reader and / or the writer simply by passing or bringing the IC card in contact with the reader and / or the writer without contact. A wireless power transmission system and IC card that transmits information in a stable manner to the internal circuit of the IC card and enables highly reliable communication of information between the reader and / or writer and the IC card. In addition, it has the effect of realizing an information communication system using an IC card. Further, according to the present invention, the reader and / or the writer device stably supplies electric power to the IC card in a non-contact manner to provide highly reliable information between the reader and / or the writer device and the IC card. It has the effect of realizing an information communication system that uses an IC card that enables communication (transmission and reception).

[Simple explanation of drawings]

[Figure 1]

It is a figure which shows the schematic structure of the electric power transmission system which wirelessly transmits electric power to the IC card which passes or is approaching non-contactly from the reader and / or the writer provided in the ticket gate of the station and the bus which concerns on this invention. ..

[Figure 2]

It is a figure which shows the electric power transmission system by radio which concerns on this invention.

[Fig. 3]

It is a figure which shows the relationship between the distance d between a coil of a power supply circuit provided in a reader and / or a writer, and an IC card, and an induced voltage VL obtained from a rectifier circuit.

[Fig. 4]

It is a figure which shows the schematic structure of the 1st Embodiment of the electric power transmission control system by radio which concerns on this invention.

[Fig. 5]

It is a figure which shows the schematic structure of the 2nd Embodiment of the electric power transmission control system by radio which concerns on this invention.

[Fig. 6]

It is a figure which shows the specific 1st Embodiment of the variable impedance circuit 30 shown in FIG.

[Fig. 7]

It is a figure which shows the state which the induced voltage is controlled within the permissible range based on the impedance control.

[Fig. 8]

It is a figure which shows the specific 2nd Embodiment of the variable impedance circuit 30 shown in FIG.

[Fig. 9]

It is a figure which shows the specific 3rd Embodiment of the variable impedance circuit 30 shown in FIG.

[Fig. 10]

It is a figure which shows the schematic structure of the 3rd Embodiment of the power transmission control system by radio which concerns on this invention.

[Fig. 11]

It is a figure which shows the schematic structure of the 4th Embodiment of the power transmission control system by radio which concerns on this invention.

[Fig. 12]

It is a schematic block diagram which shows the 1st Embodiment about the whole including the part which serves as a ticket, a commuter pass, etc. by transmitting and receiving information of a ticket, a commuter pass, etc. by using the radio which concerns on this invention. ..

[Fig. 13]

It is a top view which shows the mounting state of the IC card which concerns on this invention.

[Fig. 14]

It is a schematic block diagram which shows the 2nd Embodiment about the whole including the part which serves as a ticket, a commuter pass, etc. by transmitting and receiving information of a ticket, a commuter pass, etc. by using the radio which concerns on this invention. ..

[Fig. 15]

It is a figure which shows the relationship between the power transmission wave and the data communication modulation wave which concerns on this invention.

[Explanation of symbols]

1 ... reader and / or writer (R / W unit), 2 ... IC card, 21, 21a, 21b ... power circuit, 22 ... power supply, 22a ... control power supply, 23 .. .Matching circuit, 24 ... coil, 26 ... coil, 28, 28a, 28b ... induced voltage generator, 29 ... internal circuit, 30 ... variable impedance circuit, 31 ... voltage detection Circuit, 32 ... control circuit, 36 ... coil, 37 ... coil, 51 ... information transmitter / receiver, 52 ... CPU, 53 ... memory, 54, 65 ... modulator, 55, 64 ... demodulator, 59 ... coil, 62 ... CPU, 63 ... memory 101 ... R / W coil, 102 ... matching circuit (feeding circuit), 103 ... inductance coupling, 105 ... power supply, 106 ... transmission data, 107 ... coding circuit, 108. .. Modulator, 109 ... Transmit amplifier, 110 ... Filter circuit, 111 ... Receive amplifier, 112 ... Demodulator, 113 ... Decoding circuit, 201 ... Card coil, 202. .. Wireless chip, 203 ... matching / rectifying circuit, 205 ... DC voltage power supply, 206 ... clock extraction circuit, 207 ... LPF circuit, 208 ... waveform shaping circuit, 209 ... load Switching modulation circuit, 210 ... CPU + interface chip, 211 ... frequency division circuit, 212 ... decoding circuit, 213 ... reception data control circuit, 214 ... microcomputer, 215 ... transmission data control Circuit, 216 ... coding circuit