JP5067613B2 - Signal processing apparatus and method, and non-contact IC card device - Google Patents

Description

  The present invention relates to a signal processing apparatus and method, and a non-contact IC card device, and more particularly to a signal processing apparatus and method and a non-contact IC card that can be easily developed and can suppress an increase in cost. Regarding devices.

  2. Description of the Related Art Conventionally, there is a non-contact IC card that incorporates an integrated circuit (IC chip) and an antenna and performs near field communication with other devices such as a reader / writer. This non-contact IC card is compact and has good portability, and also has high reliability because it uses an IC chip. For example, ID cards, credit cards, point cards, etc. are used for authentication and payment purposes. Often done.

  FIG. 1 is a block diagram showing a configuration example of a conventional non-contact IC card.

  As shown in FIG. 1, the non-contact IC card 100 includes a non-contact IC card chip 101 made of a semiconductor integrated circuit, a loop antenna 102, and a capacitor 103.

  The non-contact IC card chip 101 is provided with a CP terminal which is a signal input / output terminal and a CM terminal which is a clock extraction terminal, and a loop antenna 102 and a capacitor 103 are connected in parallel between both terminals. In the non-contact IC card chip 101, the CP terminal is connected to one terminal of each of the capacitor 111 and the resistor 112, and the other terminal is grounded. Further, a regulator 114 for rectifying a signal is connected to the CP terminal via a resistor 113. The signal input to the CP terminal is converted to a constant voltage by the regulator 114 and then used as a power source such as a CPU. Is supplied to the IC card control unit 121.

  The CP terminal is also connected to an input terminal of a demodulator 115 that demodulates a modulation signal input from the CP terminal, and a resistor 117. The output terminal of the demodulator 115 is connected to the IC card controller 121, and the signal demodulated by the demodulator 115 is supplied to the IC card controller 121. The other terminal of the resistor 117 is connected to the drain of an FET (Field Effect Transistor) 116 and the source is grounded. A signal to be transmitted from the IC card control unit 121 to an external device such as a reader / writer is supplied to the gate of the FET 116, and the drain voltage (that is, the CP voltage) varies according to the supply signal. By doing so, a transmission signal is generated.

  Further, the input terminal of the clock extraction unit 119 is connected to the CM terminal, and the clock signal generated by the clock extraction unit 119 is supplied to the IC card control unit 121 as an operation clock.

  The IC card control unit 121 performs control processing and arithmetic processing for the non-contact IC card 100 to realize a function as a non-contact IC card. The IC card control unit 121 includes an EEPROM (Electronically Erasable and Programmable Read Only Memory) 131.

  Next, an operation example of this non-contact IC card will be described.

  First, for example, when an antenna or the like of an external reader / writer is brought close to the loop antenna 102 and a signal is transmitted from the external device, the magnetic field changes in the loop antenna 102 and an electromotive force is generated. That is, a signal transmitted from an external device is received by the loop antenna 102 and supplied to the CP terminal and the CM terminal. This received signal is rectified by the diode 118 provided between the CM terminal and GND (ground) and (2) the capacitor 111 connected to the CP terminal side, and then is constant-voltaged by the regulator 114 to serve as an operating power source. It is supplied to the IC card control unit 121. At the same time, the rectified voltage is input to the demodulator 115, demodulated, and supplied to the IC card controller 121. Thereby, the IC card control unit 121 acquires information transmitted from an external device. The IC card control unit 121 updates the information stored in the EEPROM 131 using the acquired information.

  Further, the IC card control unit 121 reads the information stored in the EEPROM 131, generates transmission data, drives the FET 116 according to the transmission data, and varies the potential of the CP terminal, thereby changing the loop antenna 102. The transmission data is transmitted as a signal to an external device.

  In recent years, in order to improve the convenience of contactless IC cards, a small display device is provided on the surface of the contactless IC card, and information held by the IC chip (for example, ID information, balance information, or It is also considered to improve the convenience of the card by displaying the history information etc. on the display device (see, for example, Patent Document 1).

JP 2003-208582 A

  By the way, a display device is not provided in a non-contact IC card which is currently popularized, and a display function is not provided in an IC chip mounted on the card. Therefore, in order to give a display function to a non-contact IC card, the conventional IC chip for non-contact IC card cannot be used as it is, and a function to display the retained information on the display device is added. New IC chips need to be developed. However, it is not easy to add a display function while maintaining communication performance and to achieve a certain yield. As a result, the development cost and the manufacturing cost of the product increase, and as a result, there is a possibility that the penetration rate of the product is increased.

  Therefore, a method of realizing a non-contact IC card with a display function using the IC chip (non-contact IC card chip) of the existing non-contact IC card shown in FIG. In other words, in addition to the existing non-contact IC card chip in the non-contact IC card, a display device and an IC chip for display control processing (display control processing chip) for controlling the display are provided. The internal data of the non-contact IC card chip is read by wire, and the data to be displayed is displayed on the display device according to the result.

  However, as shown in FIG. 1, the conventional contactless IC card chip 101 is only connected to the loop antenna 102 (and the capacitor 103), and has a circuit configuration that performs wired readout. Absent.

  More specifically, the contactless IC card chip 101 does not have a terminal for supplying power, for example, and the contactless IC card chip 101 is driven even if an information read command is simply input to the CP terminal. do not do.

  As described above, there is a fear that it is difficult to read information from a conventional chip for a non-contact IC card.

  The present invention has been proposed in view of such circumstances, and facilitates development and suppresses an increase in cost.

A first aspect of the present invention is an electronic circuit that transmits and receives signals to and from other devices via an antenna, and includes a pair of signal input / output terminals , a writable storage unit that stores information, and the storage unit and a control unit for controlling the input and output of information, and an electronic circuit driven by the drive power that is generated based on the input signal, to one of the signal input and output terminals, said electronic circuit is a voltage that can drive Information of a command that reads the information stored in the storage unit and outputs a signal including the read information via one of the signal input / output terminals to the electronic circuit that can generate the power supply voltage Including a first signal supply means for supplying a signal having a predetermined waveform, a second signal supply means for supplying a synchronization signal to the other of the signal input / output terminals, and one of the signal input / output terminals . Connect to the antenna And a switching means for switching between the first signal supply means.

The first aspect of the present invention is also an electronic circuit that transmits and receives signals to and from other devices via an antenna, and includes a pair of signal input / output terminals , a writable storage unit that stores information, A control unit that controls input / output of information in the storage unit, and controls one switching destination of the signal input / output terminal of the electronic circuit driven by the driving power generated based on the input signal by controlling the switching unit. Switching between the antenna and the first signal supply unit, and controlling the first signal supply unit connected to one of the signal input / output terminals by the switching, with respect to one of the signal input / output terminals The electronic circuit can generate a power supply voltage that can be driven , reads information stored in the storage unit from the electronic circuit, and outputs a signal including the read information to the signal input / output terminal. Out through one side Supplying a signal of a predetermined waveform including information of the instruction to be force to control the second signal supplying unit, relative to the other of the signal input and output terminals, is a signal processing method comprising the step of supplying a synchronization signal .

According to a second aspect of the present invention, there is provided an antenna and a semiconductor integrated circuit that transmits / receives a signal to / from another device via the antenna, a pair of signal input / output terminals, and a writable memory that stores information and parts, and a control unit for controlling input and output of information in the storage unit, and a semiconductor integrated circuit for driving the drive power that is generated based on the input signal, to one of said signal input-output terminal, wherein The semiconductor integrated circuit that can generate a power supply voltage that can be driven by the semiconductor integrated circuit is read from the information stored in the storage unit, and a signal including the read information is output to the signal input / output terminal. First signal supply means for supplying a signal having a predetermined waveform including information on a command to be output via one of the signals; and second signal supply means for supplying a synchronization signal to the other of the signal input / output terminals The above And switching means for switching one of the connection destination of the signal input-output terminal between said first signal supply means and the antenna, said switching means by the signal input connected to said first signal supplying means to one terminal A signal acquisition means for acquiring a response signal including information read from the storage unit , which is output from one of the signal input / output terminals based on an instruction included in a signal supplied from the signal input / output terminal , and acquired by the signal acquisition means A non-contact IC card device further comprising display means for displaying information included in the response signal.

According to a first aspect of the present invention, there is provided an electronic circuit that transmits / receives a signal to / from another device via an antenna, a pair of signal input / output terminals , a writable storage unit that stores information, and the storage And an electronic circuit driven by driving power generated based on the input signal, and the electronic circuit can be driven with respect to one of the signal input / output terminals. Predetermined information including instructions for reading information stored in the storage unit and outputting a signal including the read information via one of the signal input / output terminals to an electronic circuit capable of generating a power supply voltage of the voltage Is supplied from the first signal supply unit , one connection destination of the signal input / output terminal is switched between the antenna and the first signal supply unit, and the other of the signal input / output terminals is Sync signal is second signal Supplied from the supply unit .

In a second aspect of the present invention, in the semiconductor integrated circuit, a pair of signal input / output terminals, a writable storage unit for storing information, and a control unit for controlling input / output of information in the storage unit are provided. provided, is driven by a driving power that is generated based on the input signal, to one of the signal input and output terminals of the semiconductor integrated circuit, the semiconductor integrated circuit can generate a supply voltage of a voltage that can drive the semiconductor integrated A signal having a predetermined waveform including information of an instruction for reading out information stored in the storage unit and outputting a signal including the read information via one of the signal input / output terminals is supplied to the circuit as a first signal. From the second signal supply unit , and one connection destination of the signal input / output terminal is switched between the antenna and the first signal supply unit. And that A storage unit built in the semiconductor integrated circuit that is output from one of the signal input / output terminals based on a command included in a signal supplied from the first signal supply unit connected to one of the signal input / output terminals by switching A response signal including information to be read out is acquired, and information included in the acquired response signal is displayed.

  According to the present invention, information can be easily acquired from an electronic circuit that does not have a power supply terminal. In particular, an increase in the development cost of a contactless IC card with a display function can be suppressed.

  Embodiments of the present invention will be described below.

  FIG. 2 is a diagram showing a configuration example of a contactless IC card to which the present invention is applied.

  In FIG. 2, a non-contact IC card 200 is a card-type device that incorporates an integrated circuit (IC chip) and an antenna, and performs near field communication with other devices such as a reader / writer, and is held by the IC chip. This is a non-contact IC card with a display function that also has a display function for displaying information and the like. This non-contact IC card 200 is small and has good portability, and also has high reliability because it uses an IC chip. For example, an ID card, a credit card, a point card, etc., for authentication and settlement purposes. Used.

  As shown in FIG. 2, the non-contact IC card 200 includes, in addition to the non-contact IC card chip 101, the loop antenna 102, and the capacitor 103, which are used in the conventional non-contact IC card 100 having no display function. It has a wired information reading unit 210 that reads information from the non-contact IC card chip 101 in a wired manner, and a display device 241 that displays information.

  As described with reference to FIG. 1, the non-contact IC card chip 101 is an electronic circuit that transmits and receives signals to and from other devices such as a reader / writer via the loop antenna 102. The non-contact IC card chip 101 is connected to the loop antenna 102 (and the capacitor 103) via a CP terminal which is a signal input / output terminal. That is, a signal transmitted from another device received by the loop antenna 102 is input to the non-contact IC card chip 101 via the CP terminal. As described with reference to FIG. 1, the non-contact IC card chip 101 does not have a power supply terminal, and is based on a signal transmitted from another device that is input via the CP terminal. A power supply voltage is generated and driven by the power supply voltage.

  The display device 241 is configured by a small display device capable of displaying characters and images, such as an LCD (Liquid Crystal Display), an organic EL display (Organic ElectroLuminescence Display), or electronic paper. The display device 241 may be any device, but it is desirable that the display device 241 be small, thin, and light enough to be mounted on a card type device. Further, it is desirable that the display capability is high definition enough to display a certain amount of information. However, the lower the development cost, manufacturing cost, power consumption, etc., the better.

  The wired information reading unit 210 generates a signal including a read command for reading information stored in the EEPROM 131 inside the non-contact IC card chip 101 (hereinafter referred to as “read signal”), and the non-contact IC card chip 101, and an element for causing the display device 241 to display an image corresponding to the signal returned from the chip 101. The read signal generator 211, the electronic switch 212, the demodulator 213, the clock generator 214, and An electronic switch 215 is included.

  The electronic switch 212 is a switch circuit for switching the connection destination of the CP terminal which is the signal input / output terminal of the non-contact IC card chip 101. In the example of FIG. 2, the electronic switch 212 is a three-terminal switch, and connects the CP terminal of the non-contact IC card chip 101 to either the loop antenna 102 or the read signal generation unit 211. The operation of the electronic switch 212 is controlled by the display control unit 221 of the read signal generation unit 211. That is, the connection destination of the CP terminal is switched based on the control of the display control unit 221. Note that any switch may be used as the electronic switch 212 as long as the CP terminal can be connected to at least the loop antenna 102 and the readout signal generation unit 211. However, the simpler the configuration, the smaller the circuit scale and the easier the control, so the cost can be reduced. For example, if the communication performance of the non-contact IC card 200 (the non-contact IC card chip 101) does not deteriorate to a practical extent, the electronic switch 212 is omitted and the CP terminal is connected to the loop antenna 102 and the read signal is generated. You may make it connect to both of the part 211. FIG.

  The demodulator 213 is a processing unit configured as a demodulator that demodulates the modulated signal by a predetermined method corresponding to the modulation method. The demodulator 213 demodulates the modulation signal output from the contactless IC card chip 101 (CP terminal thereof) and supplied via the electronic switch 212, and reads the obtained demodulated signal (demodulation signal) as a read signal. This is supplied to the display control unit 221 of the generation unit 211. The demodulator 213 is for demodulating a signal transmitted / received from the contactless IC card chip 101, and thus basically has the same configuration as the demodulator 115 inside the contactless IC card chip 101. Just do it. For example, the development cost of the demodulation unit 213 can be reduced by applying the existing demodulation unit 115. Of course, the demodulator 213 may have a different demodulation function from the demodulator 115.

  The clock generation unit 214 is a circuit that generates and outputs a clock signal that is a synchronization signal. The clock generator 214 is connected to the loop antenna 102 via the electronic switch 215 and is input to the CM terminal of the non-contact IC card chip 101. The electronic switch 215 is a two-terminal switch that connects and disconnects both terminals, and controls the input of the clock signal output from the clock generator 214 to the CM terminal. Although not shown, the operation of the electronic switch 215 is controlled by the display control unit 221. Specifically, while the CP terminal is connected to the read signal generation unit 211 by the electronic switch 212, both terminals of the electronic switch 215 are connected, and the clock signal generated in the clock generation unit 214 is input to the CM terminal. . Both terminals of the electronic switch 215 are disconnected while the CP terminal is connected to the loop antenna 102 by the electronic switch 212, that is, while the non-contact IC card chip 101 is communicable with an external reader / writer. The clock signal generated by the clock generator 214 is prevented from being input to the CM terminal.

  When the CP terminal is not connected to the loop antenna 102 by the electronic switch 212, that is, when the contactless IC card chip 101 cannot communicate with the external reader / writer, A read signal having a predetermined waveform that can generate a power supply voltage that can be driven by the non-contact IC card chip 101 is generated and supplied to the terminal. When this signal is generated, the read signal generator 211 receives a signal similar to a signal received by the loop antenna 102 and transmitted from an external reader / writer or the like, that is, a voltage at which the non-contact IC card chip 101 can be driven. A signal capable of generating a power supply voltage is generated. As a result, the non-contact IC card chip 101 can acquire and drive the signal supplied from the read signal generation unit 211 in the same manner as when the signal is received via the loop antenna 102. That is, the wired information reading unit 210 drives the non-contact IC card chip 101 and reads information from the non-contact IC card chip 101 in the same manner as when the reader / writer reads information from the non-contact IC card chip 101. It can be done. As a result, it is possible to read information from the chip 101 without adding any special measures to the existing non-contact IC card chip 101.

  As shown in FIG. 2, the read signal generation unit 211 includes a display control unit 221, a non-contact IC drive power supply 222, a data transmission FET 223, a resistor 224, and a resistor 225.

  The display control unit 221 is a control unit related to processing for causing the display device 241 to display information stored in the EEPROM 131. In other words, the display control unit 221 generates and outputs a transmission signal that is a signal including a read command for reading information stored in the EEPROM 131, and outputs a demodulation signal output from the demodulation unit 213, that is, reads from the EEPROM 131. The acquired information is acquired, or the acquired information or new information generated from the information is displayed on the display device 241. The display control unit 221 has a built-in EEPROM 231 as a storage unit, and the information read from the EEPROM 131 acquired from the demodulation unit 213 can be held in the EEPROM 231. Note that any storage medium may be used in place of the EEPROM 131 as long as it has a response speed that does not cause a practical problem. However, it is desirable that the circuit scale of this storage medium is smaller. Also, the smaller the cost, the better.

  The non-contact IC driving power source 222 is a direct-current voltage source (for example, a solar cell) that generates a direct-current voltage VDD, and a direct-current component supply unit that supplies a direct-current component of a voltage that can drive the non-contact IC card chip 101. Function as.

  The data transmission FET 223 has a source grounded and a gate connected to the display control unit 221. As shown in FIG. 2, the DC voltage VDD generated by the non-contact IC drive power supply 222 is supplied to the terminal of the electronic switch 212 via the resistor 224. It fluctuates according to the gate voltage value of the trust FET 223. Therefore, by supplying at least a binary transmission signal (AC component) from the display control unit 221 to the gate, it is possible to displace the voltage value applied to the terminal of the electronic switch 212 and generate a modulation signal. . As a result, the data transmission FET 223 functions as a synthesis unit that synthesizes the transmission signal generated in the display control unit 221, that is, the AC component, with the DC component generated in the non-contact IC driving power source 222.

  At this time, since the terminal voltage of the electronic switch 212 fluctuates using the direct-current voltage VDD as a reference voltage, the non-contact IC card chip 101 always has a predetermined value or more (that is, a drivable voltage value or more). A voltage value can be secured. The output of the non-contact IC drive power supply 222 is a voltage that can acquire a power supply voltage at a level that can drive the non-contact IC card chip 101 as a result of rectification in the non-contact IC card chip 101 (including a DC component). However, for the sake of convenience of explanation, it is assumed that the voltage is constant. The data transmission FET 223 only needs to be able to modulate the output of the non-contact IC driving power source 222, and other than the FET can be applied.

  As described above, the readout signal generation unit 211 combines the AC component generated by the display control unit 221 with the DC component generated by the non-contact IC driving power source 222 using the data transmission FET 223. Thus, it is possible to easily generate a read signal capable of generating a power supply voltage that can drive the non-contact IC card chip 101.

  As shown in FIG. 2, the wired information reading unit 210 has the same configuration as the non-contact IC card chip 101. For example, the non-contact IC card chip 101 includes the demodulation unit 115, while the wired information reading unit 210 includes the demodulation unit 213. The non-contact IC card chip 101 has a regulator 114, whereas the wired information reading unit 210 has a non-contact IC driving power source 222. Further, the non-contact IC card chip 101 has a resistor 113, whereas the wired information reading unit 210 has a resistor 224. Further, the non-contact IC card chip 101 has a resistor 117, whereas the wired information reading unit 210 has a resistor 225. Further, the non-contact IC card chip 101 has the FET 116, whereas the wired information reading unit 210 has the data transmission FET 223. The non-contact IC card chip 101 includes the diode 118 and the clock extraction unit 119, whereas the wired information reading unit 210 includes the clock generation unit 214.

  Therefore, the wired information reading unit 210 can generate a read signal in the same manner as the non-contact IC card chip 101, and can process a signal supplied from the non-contact IC card chip 101. . That is, the wired information reading unit 210 can easily generate a signal that can be driven by the contactless IC card chip 101 and can easily read information from the contactless IC card chip 101.

  Although not shown, the non-contact IC card 200 requires power supply means for driving the wired information reading unit 210 and the display device 241. This power supply means may be one that generates a power supply voltage inside the non-contact IC card 200, such as a battery, or obtains a power supply voltage supplied from the outside of the non-contact IC card 200. , May be appropriately provided to each part.

  FIG. 3 is a functional block diagram illustrating functions of the display control unit 221 in FIG. As illustrated in FIG. 3, the display control unit 221 includes an electronic switch control unit 251, a transmission signal supply unit 252, a signal acquisition unit 253, an information storage unit 254, and an output control unit 255.

  The electronic switch control unit 251 is a control unit that controls the read signal generation unit 211, the electronic switch 212, and the electronic switch 215 of FIG. 2, and at a predetermined timing or with a predetermined event as a trigger, the read signal generation unit 211. A control signal is supplied to each of the electronic switch 212 and the electronic switch 215. As a result, the connection state is switched in the electronic switches 212 and 215, and a read signal is generated in the read signal generator 211 and supplied to the CP terminal.

  The method for determining the switching timing of the electronic switch 212 is arbitrary. For example, a sensor (for example, a magnetic field sensor) for detecting the presence of an external device is provided, and the switching timing is set based on the detection result of this sensor. It may be determined.

  The transmission signal supply unit 252 functions as an AC component supply unit that supplies an AC component having a predetermined waveform (that is, a transmission signal) among signals supplied from the wired information reading unit 210 to the CP terminal. For example, the transmission signal supply unit 252 generates a transmission signal including a command for reading information stored in the EEPROM 131 and supplies the transmission signal to the data transmission FET 223. Thereby, the read signal generator 211 can generate a read signal.

  The signal acquisition unit 253 acquires a response signal including information read from the EEPROM 131 that is output from the CP terminal based on a read command included in the signal supplied from the wired information reading unit 210 to the CP terminal. Function as. The signal acquisition unit 253 acquires the demodulated signal demodulated by the demodulation unit 213 and supplies the acquired signal to the information storage unit 254. Thereby, the wired information reading unit 210 can not only supply the read signal to the non-contact IC card chip 101 but also obtain a response signal output from the non-contact IC card chip 101.

  The information storage unit 254 is a processing unit that stores information included in the signal acquired by the signal acquisition unit 253 in the EEPROM 231 configured as a storage unit. Accordingly, the wired information reading unit 210 can store information included in the response signal output from the non-contact IC card chip 101, and access to the non-contact IC card chip 101 for information display. And the power consumption of the non-contact IC card 200 can be reduced.

  The output control unit 255 functions as a display control unit that causes the display device 241 to display information stored in the EEPROM 231. The output control unit 255 appropriately reads information from the EEPROM 231 and causes the display device 241 to display image information including at least one of the information and new information generated from the information. Thereby, the non-contact IC card 200 can display more appropriate information on the display device 241.

  Next, an example of the flow of information reading processing for reading information stored in the EEPROM 131 will be described with reference to the flowchart of FIG. This will be described with reference to FIGS. 5 to 10 as necessary.

  When the information reading process is started, the electronic switch control unit 251 determines whether or not to read data stored in the EEPROM 131 of the non-contact IC card chip 101 in step S1. If it is determined not to read data, the electronic switch control unit 251 advances the process to step S <b> 2 to control the electronic switch 212 to connect the CP terminal to the loop antenna 102. The electronic switch control unit 251 controls the electronic switch 215 in step S3 to release the connection between both terminals, and stops supplying the clock generated by the clock generation unit 214 to the non-contact IC card chip 101. To do.

  That is, in this case, the non-contact IC card chip 101 operates in the same manner as the conventional non-contact IC card 100 and communicates with a reader / writer outside the card. That is, when the magnetic field near the loop antenna 102 is changed by the reader / writer outside the card, an electromotive force is generated in the loop antenna 102. FIG. 5 is a graph showing a waveform of the electromotive force induced in the loop antenna 102. That is, the loop antenna 102 receives a signal having a waveform as indicated by the signal 301 in FIG. This signal is input to the non-contact IC card chip 101 via the CP terminal.

  The non-contact IC card chip 101 rectifies this signal by the diode 118 and the capacitor 111. FIG. 6 is a graph showing changes in voltage after rectification generated at the CP terminal. As shown in FIG. 6, the signal 301 received by the loop antenna 102 is rectified like a signal 302 to generate a power supply voltage. The non-contact IC card chip 101 is driven by using the power supply voltage (power) generated by rectification, and further demodulates the rectified signal 302 by the demodulator 115, and includes information contained in the signal (transmitted from the reader / writer). Information). The IC card control unit 121 rewrites the information stored in the EEPROM 131 using this information, or reads the information stored in the EEPROM 131 to generate transmission data. Based on the transmission data, the IC card control unit 121 drives the FET 116 to perform modulation, and transmits the modulation signal to a reader / writer outside the card via the CP terminal and the loop antenna 102.

  In step S4, the display control unit 221 determines whether or not to end the information reading process. If it is determined to end, the information reading process is ended. Conversely, if it is determined in step S4 that the information reading process is not terminated, the display control unit 221 returns the process to step S1 and causes the subsequent processes to be executed.

  If it is determined in step S <b> 1 that data is to be read, the electronic switch control unit 251 advances the process to step S <b> 5, controls the electronic switch 212, and connects the CP terminal to the read signal generation unit 211. In step S6, the electronic switch control unit 251 controls the electronic switch 215 to connect both terminals, and starts supplying the clock generated by the clock generation unit 214 to the contactless IC card chip 101. .

  In step S <b> 7, the non-contact IC driving power source 222 starts supplying driving power that can drive the non-contact IC card chip 101. In step S <b> 8, the transmission signal supply unit 252 generates a transmission signal including a read command having a waveform such as the signal 303 illustrated in FIG. 7 and supplies the transmission signal to the gate of the data transmission FET 223.

  In step S9, the data transmission FET 223 supplied with the transmission signal synthesizes the DC component and the AC component by applying the power supply voltage supplied from the non-contact IC driving power supply 222 as a bias to the transmission signal. In other words, the data transmission FET 223 modulates the power supply voltage supplied from the non-contact IC drive power supply 222 with the transmission signal, and generates a read signal having a waveform such as the signal 304 shown in FIG. This read signal is input to the non-contact IC card chip 101 via the CP terminal.

  The voltage generated at the CP terminal at this time will be described with reference to FIG. FIG. 9 is an equivalent circuit schematically showing a configuration relating to the potential of the CP terminal when the wired information reading unit 210 reads information from the non-contact IC card chip 101.

  As shown in FIG. 9, when the resistance value of the resistor 224 of the wired information reading unit 210 is R1, the resistance value of the resistor 225 is R2, and the resistance value of the resistor 117 of the contactless IC card chip 101 is R3, The impedance inside the non-contact IC card chip 101 is substantially equal to R3. The resistance value R3 is substantially equal to the circuit load of the non-contact IC card chip 101 when the non-contact IC card chip 101 receives a signal via the loop antenna 102. That is, the circuit load of the non-contact IC card chip 101 when the wired information reading unit 210 supplies a read signal is substantially the same as that when the reader / writer transmits the signal.

  Therefore, the non-contact IC card 200 at this time can be represented by an equivalent circuit shown in FIG. Therefore, when the data transmission FET 223 is in the OFF state, the CP voltage, which is the voltage at the CP terminal, can be expressed as the following equation (1).

  Further, when the data transmission FET 223 is in the ON state, the CP voltage can be expressed as the following formula (2).

  That is, when the state of the data transmission FET 223 is switched by the transmission signal, the CP voltage alternately takes the binary values of the above-described equations (1) and (2). That is, a read command is included as the CP voltage displacement timing (AC component of this switching).

  The non-contact IC card chip 101 is driven based on this read signal, reads information stored in the EEPROM 131 based on a read command included in the read signal, and outputs it from the CP terminal as a response signal. At this time, the non-contact IC card chip 101 uses the FET 116 to generate a response signal having a waveform such as a signal 305 shown in FIG. To do.

  Returning to FIG. 4, when the demodulation unit 213 acquires the response signal of the read signal in step S <b> 10, the demodulation unit 213 demodulates the response signal and supplies the demodulated signal indicating the information read from the EEPROM 131 to the display control unit 221. In step S <b> 11, the signal acquisition unit 253 acquires the demodulated signal and supplies it to the information storage unit 254. In step S <b> 12, the information storage unit 254 stores information read from the EEPROM 131 included in the supplied demodulated signal in the EEPROM 231. In step S <b> 13, the output control unit 255 causes the display device 241 to display image information related to information stored in the EEPROM 231. When the process of step S13 is completed, the process returns to step S1, and the subsequent processes are repeated.

  The information reading process is executed as described above. That is, in the non-contact IC card 200, signals having similar waveforms such as the signal 302, the signal 304, and the signal 305 are input / output at the CP terminal. That is, the wired information reading unit 210 can generate and supply a signal having a waveform similar to that of the signal input / output by the non-contact IC card chip 101, like an external reader / writer. As a result, the wired information reading unit 210 can read information stored in the EEPROM 131 of the non-contact IC card chip 101.

  As described above, the non-contact IC card 200 can realize a non-contact IC card with a display function by using the conventional non-contact IC card chip 101. That is, a non-contact IC card with a display function can be realized without developing a new dedicated IC card chip with a display function added to the conventional non-contact IC card chip 101. Thereby, it becomes easy to develop the non-contact IC card 200 without reducing the communication performance, and the increase in cost can be suppressed.

  In FIG. 2, it has been described that the terminal on the opposite side of the terminal connected to the clock generation unit 214 of the electronic switch 215 is connected to the CP terminal side of the loop antenna 102. The clock generator 214) may be connected to the CM terminal (that is, the CM terminal side of the loop antenna 102). However, in the non-contact IC card chip 101, the impedance and capacity of the circuit connected to the CM terminal are smaller than the impedance and capacity of the circuit connected to the CP terminal, and are susceptible to other influences. Therefore, as shown in FIG. 2, connecting the electronic switch 215 to the CP terminal side of the loop antenna 102 reduces the influence of the clock generator 214 on the non-contact IC card chip 101, and for the non-contact IC card. Reduction in communication performance of the chip 101 can be suppressed.

  The series of processes described above can be executed by hardware, but can also be executed by software. When a series of processing is executed by software, a program constituting the software may execute various functions by installing a computer incorporated in dedicated hardware or various programs. For example, it is installed from a program recording medium into a general-purpose personal computer or an information processing apparatus of an information processing system including a plurality of devices.

  This recording medium is distributed to distribute the program to the user separately from the main body of the apparatus, and includes a magnetic disk (including a flexible disk) on which the program is recorded, an optical disk (CD-ROM (Compact Disc-Read Only Memory). ), DVD (including Digital Versatile Disc), magneto-optical disc (including MD (Mini-Disc) (registered trademark)), or removable media such as semiconductor memory. It is composed of an EEPROM 231 in which a program is recorded, which is distributed to the user in an incorporated state.

  In the present specification, the step of describing the program recorded on the recording medium is not limited to the processing performed in chronological order according to the described order, but is not necessarily performed in chronological order. It also includes processes that are executed individually.

  In the above, the configuration described as one device may be divided and configured as a plurality of devices. Conversely, the configurations described above as a plurality of devices may be combined into a single device. Of course, configurations other than those described above may be added to the configuration of each device. Furthermore, if the configuration and operation of the entire system are substantially the same, a part of the configuration of a certain device may be included in the configuration of another device. That is, the embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

It is a block diagram which shows the structural example of the conventional non-contact IC card. It is a figure which shows the structural example of the non-contact IC card to which this invention is applied. It is a functional block diagram which shows the function which the display control part 221 of FIG. 2 has. It is a flowchart explaining the example of the flow of an information read-out process. 3 is a graph showing an example of an electromotive force waveform induced in a loop antenna 102; It is a graph which shows the example of the change of the voltage after the rectification which generate | occur | produces in CP terminal. It is a graph which shows the example of the waveform of a transmission signal. It is a graph which shows the example of the waveform of a read signal. It is an equivalent circuit which shows roughly the structure regarding the electric potential of CP terminal. It is a graph which shows the example of the waveform of a response signal.

Explanation of symbols

  101 chip for contactless IC card, 102 loop antenna, 115 demodulator, 116 FET, 117 resistor, 121 IC card controller, 131 EEPROM, 200 contactless IC card, 210 wired information read unit, 211 read signal generator, 212 Electronic switch, 213 demodulator, 214 clock generator, 215 electronic switch, 221 display controller, 222 non-contact IC drive power supply, 223 data transmission FET, 224 resistor, 225 resistor, 231 EEPROM, 241 display device, 251 electronic Switch control unit, 252 transmission signal supply unit, 253 signal acquisition unit, 254 information storage unit, 255 output control unit

Claims (12)

An electronic circuit that transmits and receives signals to and from other devices via an antenna, a pair of signal input / output terminals ,
A writable storage unit for storing information;
An electronic circuit that is driven by driving power generated based on an input signal, and a control unit that controls input / output of information in the storage unit ;
The information stored in the storage unit is read out from the electronic circuit, which can generate a power supply voltage that can drive the electronic circuit with respect to one of the signal input / output terminals. First signal supply means for supplying a signal having a predetermined waveform including information on a command to output a signal including the signal via one of the signal input / output terminals ;
Second signal supply means for supplying a synchronization signal to the other of the signal input / output terminals;
Signal processing apparatus including one of the connection destination the antenna of the signal input and output terminals, and a switching means for switching between said first signal supply means. A response signal including information read from the storage unit and output from one of the signal input / output terminals based on a command included in the signal having the predetermined waveform supplied by the first signal supply unit; Further comprising a signal acquisition means for acquiring
The signal processing apparatus according to claim 1 . The response signal is a modulated signal modulated in the electronic circuit;
Further comprising demodulation means for demodulating the modulated signal;
The signal acquisition means acquires the signal demodulated by the demodulation means
The signal processing apparatus according to claim 2 . The apparatus further comprises storage means for storing information included in the response signal acquired by the signal acquisition means.
The signal processing apparatus according to claim 2 . Display means for displaying information;
The signal processing apparatus according to claim 4 , further comprising: display control means for causing the display means to display the information stored in the storage means. The controller is
When one of the signal input / output terminals is connected to the antenna by the switching means, it is generated based on an input signal supplied from another device and input through one of the antenna and the signal input / output terminal. Driven by the drive power generated, information based on information included in the input signal is stored in the storage unit, information stored in the storage unit is read, one of the signal input / output terminals and the antenna To the other device via
When one of the signal input / output terminals is connected to the first signal supply means by the switching means, it is supplied from the first signal supply means, and passes through the antenna and one of the signal input / output terminals. Driven by drive power generated based on the input signal input, and included in the input signal in synchronization with a synchronization signal supplied from the second signal supply means via the other of the signal input / output terminals Is read from the storage unit and supplied as the response signal to the signal acquisition means via one of the signal input / output terminals.
The signal processing apparatus according to claim 2. The signal processing apparatus according to claim 1, wherein the first signal supply unit supplies the signal having the predetermined waveform when the signal input / output terminal is not connected to the antenna by the switching unit. The antenna is a loop antenna, one end of the loop antenna is connected to one of the input / output terminals via the switching means, and the other end of the loop antenna is connected to the other of the input / output terminals. Be done
The signal processing apparatus according to claim 1. The signal processing apparatus according to claim 8, wherein the second signal supply unit supplies a synchronization signal to the other of the signal input / output terminals via the loop antenna . Only when one of the signal input / output terminals is connected to the first signal supply means by the switching means, the synchronization signal supplied from the second signal supply means is transferred to the other of the signal input / output terminals. Further provided is a synchronizing signal control means to be supplied.
The signal processing apparatus according to claim 1 . An electronic circuit that transmits and receives signals to and from other devices via an antenna, a pair of signal input / output terminals , a writable storage unit that stores information, and a control that controls input / output of information in the storage unit A switching unit for controlling one connection destination of the signal input / output terminals of the electronic circuit driven by the driving power generated based on the input signal, so that the antenna and the first signal supply unit Switch between
The first signal supply unit connected to the signal input / output terminal is controlled by the switching, and a power supply voltage that can drive the electronic circuit can be generated for one of the signal input / output terminals . A signal having a predetermined waveform including information of an instruction for reading the information stored in the storage unit to the electronic circuit and outputting a signal including the read information through one of the signal input / output terminals. supplied,
A signal processing method comprising: controlling a second signal supply unit to supply a synchronization signal to the other of the signal input / output terminals . An antenna,
A semiconductor integrated circuit for transmitting and receiving signals to and from other devices via the antenna, and a pair of signal input / output terminals ;
A writable storage unit for storing information;
A semiconductor integrated circuit that includes a control unit that controls input / output of information in the storage unit and is driven by driving power generated based on an input signal
The information stored in the storage unit is read and read from the semiconductor integrated circuit, which can generate a power supply voltage that can drive the semiconductor integrated circuit with respect to one of the signal input / output terminals . First signal supply means for supplying a signal having a predetermined waveform including information on a command for outputting a signal including the information via one of the signal input / output terminals ;
Second signal supply means for supplying a synchronization signal to the other of the signal input / output terminals;
Switching means for switching one connection destination of the signal input / output terminal between the antenna and the first signal supply means;
From the storage unit , which is output from one of the signal input / output terminals based on a command included in a signal supplied from the first signal supply means connected to one of the signal input / output terminals by the switching means. Signal acquisition means for acquiring a response signal including information to be read;
A non-contact IC card device comprising: display means for displaying information included in the response signal acquired by the signal acquisition means.

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