KR20020015245A - Contactless IC Card Reader of ISO-14443 Type B - Google Patents

Abstract

PURPOSE: An RF card reader is provided to realize an ISO(International Organization for Standardization)-14442 B type communication signal connection type among the communication signal connection type of the RF card. CONSTITUTION: The RF card reader comprises a transmission part(122) transmitting the data modulating a carrier wave to ASK(Amplitude Shift Keying) 10% to an RF card(110) through an antenna(121), a receiving part(123) receiving a BPSK(binary Phase Shift Keying) signal of the sub carrier wave received from the RF card through the antenna, a CPU, a memory storing a necessary data under a control of CPU and an I/O interface(126) interfacing the CPU with an outer computer(131) or outer device(132). The transmission part includes an oscillation part oscillating a carrier wave of 13.56MHz, a modulation part modulating a NRZ(Non Return to Zero) serial data transmitted to the RF card to the carrier wave with ASK 10%, a power amplifying part amplifying the modulated wave and a low pass filter filtering the power amplified signal.

Description

Contactless IC card reader of non-type {Contactless IC Card Reader of ISO-14443 Type B}

The present invention relates to a contactless IC card reader, and more specifically, to a contactless IC card reader for implementing an ISO-14443 B-type communication signal connection method among communication signal connection methods of a contactless IC card. It is about.

Modern society is flooded with so many cards in life that it is called a card society. A representative example is a magnetic stripe card (M / S card) in which a magnetic recording medium is attached to a plastic card. Such magnetic stripe cards include a cash card of a bank and a credit card of a credit company. The card reads a digital signal recorded on a magnetic stripe with a magnetic head to determine whether or not it is itself. Used to check. On the other hand, a card of a revocation ticket type such as a public telephone card is called a prepaid card or a prepaid card, which reads and writes digital signals on magnetic materials and processes data with a terminal device.

IC cards are plastic cards that contain a microprocessor and memory, allowing information to be stored and processed within the card. This IC card is an abbreviation of Integrated Circuit Card, and ISO refers to it as an IC card, but there are other smart cards, memory cards, chip-in cards, and intelligent. Also called an Intelligent Card.

The IC card can change the information stored on the IC card while performing data communication between the card reader and the IC card and a memory card that allows the card reader to simply read the service information stored on the IC card or input only simple data. It is divided into a smart card. The smart card includes a memory device that stores service information and a microprocessor that can register, change, and delete service information of the memory device, and includes a chip operating program for driving the microprocessor. The smart card not only can access the memory by a control signal supplied from an external card reader, but also perform data communication with the card reader according to the recommended protocol through the input / output unit, thereby providing information in the memory device. You may register, delete or change it from time to time.

The IC card consists of random access memory (RAM), read only memory (ROM), microprocessor, and nonvolatile memory (EEPROM). RAM is a memory for data processing of a microprocessor, ROM is a program memory for a microprocessor, and nonvolatile memory is a memory for data. That is, the nonvolatile memory stores information about the issuer and data for the issuer to provide a service, and the microprocessor stores information in the nonvolatile memory by data stored in a RAM and a program stored in a ROM. Accordingly, control to provide a desired service to the user.

The IC card is classified into two types according to the communication method with the outside. The IC card communicates by radio frequency using a contact card inserting a contact surface into a card reader and an antenna built in the card. There is a Contactless Card.

Contact cards require physical contact with a card reader to obtain a clock signal and a power source for operating the chips in the card. For this purpose, the card is inserted into the reader, and power to the card is supplied or disconnected from the reader to the card under the control of a host application or reader. This contact card is suitable for high security systems.

On the other hand, a contactless card places a card in the vicinity of a card reader, and information is exchanged between the contactless card and the card reader. The contactless card is divided into close coupling and remote coupling according to its approach distance, and the remote type is further divided into proximity, near-infrared and microwave-type. Lose. Standards are in progress at close contact (CICC) at ISO 10536, near proximity (PICC) at ISO / IEC 14443, and near-view (VICC) at ISO / IEC 15693. The close contactless card gets its power from capacitive coupling, and the remote contactless card gets its power from inductive coupling.

Such a contactless card does not need to be inserted into a card reader and does not need accurate card positioning, so it is easy to design and manufacture, and the maintenance cost can be reduced because the terminal can be manufactured ruggedly and inexpensively. In addition, since the card itself does not have a mechanical contact surface, it is resistant to static electricity, chemical damage, moisture, contamination, dust, or friction, and thus can be used for a long time. In addition, since direct connection to the IC card is not possible, content interpretation is difficult and forgery is difficult. While this contactless card has the above advantages, it has a disadvantage of weak security.

As described above, the contact card and the contactless card have advantages and disadvantages, respectively, and a combination card has been developed to compensate for the disadvantages of the two cards. This combination card, also known as a dual interface card, has contact and contactless surfaces, and has a microprocessor chip that runs through two inputs and outputs.

ISO 14443 defines the physical characteristics and proximity protocols (radio frequency power and signal connections, initialization and collision avoidance) for proximity IC cards in contactless IC cards. This standard describes two types of communication signaling connections (A-type and B-type).

When the ISO-14443 A-type communication signal is connected, the communication from the card reader to the IC card uses ASK (Amplitude Shift Keying) 100% modulation method in the radio frequency range. The IC card communicates with the card reader via the inductive coupling area. The signal transmitted from the IC card to the card reader is coded in Manchester.

Currently, most contactless card readers used in public transportation such as subways and buses are operated by communication signals of ISO-14443 A-type. On the other hand, compared to the ISO-14443 A-type card reader, the card reader of the ISO-14443 B-type is extremely weak in development, and furthermore, the technology is not disclosed, which adversely affects the spread of the ISO-14443 B-type card. .

Accordingly, an object of the present invention is to provide a contactless card reader that realizes an ISO-14443 B-type communication signal connection system.

1 is a block diagram showing an ISO-14443 B-type contactless IC card reader according to an embodiment of the present invention.

Fig. 2 is a block diagram showing a transmitting unit of an ISO-14443 B-type contactless IC card reader according to an embodiment of the present invention.

Fig. 3 is a block diagram showing a receiving unit of an ISO-14443 B-type contactless IC card reader according to an embodiment of the present invention.

※ Explanation of code about main part of drawing ※

110: contactless IC card 120: IC card reader

121: antenna 122: transmitter

123: receiving unit 124: central processing unit (CPU)

125: memory 126: input and output interface

131: computer 132: external device

211: low pass filter 212: power amplifier

213 modulator 214 oscillator

311: first band pass filter 312: subcarrier detection circuit

313: first subcarrier amplifier 314: second bandpass filter

315: second subcarrier amplifier 316: level comparator

317: subcarrier detection unit 318: subcarrier synchronization unit

319: BPSK / NRZ converter

In order to achieve the above object, an ISO-14443 B-type contactless IC card reader according to the present invention includes: transmitting means for transmitting data to be transmitted to a non-contact IC card on an ASK 10% modulated carrier;

Receiving means for receiving a BPSK signal of a subcarrier transmitted from said contactless IC card and converting it into an NRZ signal;

And a control means for processing the NRZ received signal converted by the receiving means and converting the data to be transmitted to the contactless IC card into NRZ type serial data and transmitting it to the transmitting means.

Preferably, the transmitting means comprises: an oscillator for oscillating a carrier frequency, a modulator for modulating NRZ serial data to be transmitted to the contactless IC card at an ASK of 10% on the carrier, and amplifying the signal modulated by the modulator. And a low pass filter for emitting low power through the antenna after low pass filtering the power amplified signal.

More preferably, the receiving means receives a signal received through an antenna and passes a first bandpass filter for selectively passing only a frequency band obtained by adding a frequency of a carrier wave and a frequency of a subcarrier, and the first bandpass filter. A subcarrier detection circuit for detecting a subcarrier BPSK signal from a signal, a second bandpass filter for selectively passing only a subcarrier frequency band of the detected subcarrier BPSK signals, and a signal passing through the second bandpass filter to a reference voltage A level comparator for converting to a digital signal, a subcarrier detector for outputting a detection signal by checking whether the frequency of the digitized signal in the level comparator is a subcarrier frequency, and a subcarrier BPSK signal receiving an internal clock by receiving the detection signal from the subcarrier detector. Subcarrier synchronized with And a vaporizer and a BPSK / NRZ converter converting the subcarrier BPSK signal synchronized with the internal clock by the subcarrier synchronization unit to an NRZ signal and transmitting it to the control means.

Hereinafter, an "ISO-14443 B-type IC card reader" according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

ISO 14443 defines protocols for B-type communication signaling. When connecting to this ISO-14443 B-type communication signal, the card reader modulates the data with ASK (Amplitude Shift Keying) 10% modulation over a radio frequency range and then transmits it to the contactless IC card. The contactless IC card modulates the data by Binary Phase Shift Keying (BPSK) and transfers it to the card reader. The card reader receives this BPSK signal, converts it into a Non Return to Zero (NRZ) form, and then processes the received data accordingly.

1 is a block diagram showing an ISO-14443 B-type contactless IC card reader according to an embodiment of the present invention.

Referring to FIG. 1, the contactless IC card reader 120 modulates data to ASK 10% on a carrier wave and transmits the data to the contactless IC card 110 through the antenna 121 and the contactless IC card ( Data required under the control of the receiving unit 123, the central processing unit (CPU) 124, and the central processing unit 124 to receive the BPSK signal of the subcarrier transmitted from the 110 through the antenna 121 And a memory 125 for storing data, an input / output interface 126 for interfacing data input / output between the central processing unit 124 and an external computer 131 and / or an external device 132.

2 is a block diagram showing a transmitter of an ISO-14443 B-type contactless IC card reader according to an embodiment of the present invention.

Referring to FIG. 2, the transmitting unit 122 of the contactless IC card reader 120 transmits the oscillating unit 214 for oscillating a 13.56 MHz carrier and the NRZ serial data to be transmitted to the contactless IC card 110 to the carrier 10. A modulator 213 for modulating by%, a power amplifier 212 for power amplifying the signal modulated by the modulator 213, and a low pass filter 211 for filtering the power amplified signal.

In order to explain this operation, the modulator 213 receives the NRZ serial data to be transmitted from the CPU 124 to the contactless IC card 110, receives the 13.56 MHz carrier wave oscillated by the oscillator 214, and transmits to the carrier. Modulate NRZ serial data to ASK 10%. The power amplifier 212 receives a signal modulated by the modulator 213 and amplifies it sufficiently so that it can be radiated through an antenna, and the low pass filter 211 has unnecessary harmonics in the signal amplified by the power amplifier 212. To avoid unnecessary harmonic radiation. The signal passing through the low pass filter 211 is radiated from the antenna 121 and transmitted to the contactless IC card 110.

3 is a block diagram illustrating a receiver of an ISO-14443 B-type contactless IC card reader according to an embodiment of the present invention.

Referring to FIG. 3, the receiver 123 of the contactless IC card reader 120 receives a signal received through the antenna 212 and selectively passes only a frequency band obtained by adding a frequency of a carrier wave and a frequency of a subcarrier. A subcarrier detection circuit 312 for detecting a subcarrier BPSK signal from the signal passing through the bandpass filter 311, the first bandpass filter 311, a first subcarrier amplifying circuit 313 for amplifying the detected subcarrier BPSK signal, A second subcarrier amplification that sufficiently amplifies a signal passing through the second bandpass filter 314 and the second bandpass filter 314 selectively passing only a subcarrier frequency band among the signals output from the first subcarrier amplifying circuit 313. A level comparator 316 and a level comparator for converting the subcarrier BPSK signal sufficiently amplified by the circuit 315 and the second subcarrier amplifier circuit 315 into a digital signal in comparison with a reference voltage. The subcarrier detector 317 and the subcarrier detector 317 detect whether the frequency of the digitized signal is the subcarrier frequency, that is, the period of the received signal and output a high / low level detection signal. The subcarrier synchronization unit 318 for synchronizing the internal clock with the received subcarrier, and the subcarrier synchronization unit 318 sample the subcarrier BPSK signal synchronized with the internal clock, converts the subcarrier BPSK signal into an NRZ signal, and transfers the signal to the CPU. / NRZ conversion unit 319 is included.

Looking at the operation of the receiver configured as described above are as follows. First, when a signal is received through the antenna 121, the 14.4075 MHz first bandpass filter 311 selectively selects a frequency obtained by adding the frequency of the carrier wave transmitted from the non-contact IC card 110 and the frequency of the subcarrier, that is, the frequency band of 14.4075 MHz. Pass it through. The subcarrier detection circuit 312 detects only the subcarrier BPSK signal from the signal passing through the 14.4075 MHz first bandpass filter 311.

The first subcarrier amplifying circuit 313 amplifies the subcarrier BPSK signal detected by the subcarrier detecting circuit 312, and the second bandpass filter 314 is the frequency of the subcarrier among the signals amplified by the first subcarrier amplifying circuit 313. Only pass the signal of 847KHz. The second subcarrier amplifying circuit 315 sufficiently amplifies the signal passing through the second bandpass filter 314 to the level required by the next level comparator 316, and the level comparator 316 is sufficiently amplified subcarrier PBSK. The signal is converted into a digital signal by comparing with the reference voltage and output.

The subcarrier detector 317 confirms whether the frequency of the digitized signal in the level comparator 316 is 847 KHz. That is, if the period of the received signal is checked and a signal of a lower frequency or a higher frequency than the subcarrier is input, a low level detection signal is output. If the period of the received signal is a normal 847 kHz signal, the high level detection signal is output. Output The detection signal output from the subcarrier detector 317 is transmitted to the subcarrier synchronization unit 318 which is the next block. When the subcarrier synchronization unit 318 transmits a signal indicating that the subcarrier has been received from the subcarrier detector 317, the subcarrier synchronization unit 318 synchronizes an internal clock with the received subcarrier. That is, the signal output from the 1.7 MHz signal generator, which is twice the frequency of 847 KHz, is synchronized to 847 KHz. The subcarrier BPSK signal synchronized with the internal clock in the subcarrier synchronizer 318 is transmitted to the BPSK / NRZ converter 319.

The BPSK / NRZ converter 319 samples a synchronized subcarrier into a 1.7 MHz signal and compares each received data with the phase of the initially received signal. If the signal is 180 degrees out of phase with the initial received signal, a low level is output. By doing so, the BPSK signal received at the contactless IC card 110 is converted into an NRZ signal.

The central processing unit 124 reads serial data converted into the NRZ form by the BPSK / NRZ conversion unit 319 and stores the read data in the memory 125, or by using the input / output interface 126. B transmits to the external device (132).

In addition, the data received from the computer 131 or the external device 132, or the data of the memory 125 is converted into serial data in the form of NRZ and transmitted to the transmitter 122, and the transmitter 122 is thus sent Serial data is ASK 10% modulated and transmitted to the contactless IC card 110 through the antenna 110.

While the invention has been described above based on the preferred embodiments thereof, these embodiments are intended to illustrate rather than limit the invention. It will be apparent to those skilled in the art that various changes, modifications, or adjustments to the above embodiments can be made without departing from the spirit of the invention. Therefore, the protection scope of the present invention will be limited only by the appended claims, and should be construed as including all such changes, modifications or adjustments.

According to the present invention as described above, it is possible to use as needed through the use of a contactless card reader that communicates with the contactless IC card in the communication signal connection method of ISO-14443 B-type.

Claims (3)

A card reader for data communication with a contactless IC card and a communication signal connection method of ISO-14443 B-type, Transmitting means for loading data to be transmitted to the contactless IC card on an ASK 10% modulated carrier and transmitting the data to the IC card; Receiving means for receiving a BPSK signal of a subcarrier transmitted from said contactless IC card and converting it into an NRZ signal; And And a control means for processing the NRZ received signal converted by the receiving means and converting data to be transmitted to the contactless IC card into NRZ type serial data and transmitting the same to the transmitting means. . The method of claim 1, wherein the transmitting means, An oscillator for oscillating a carrier frequency, A modulator for modulating NRZ serial data to be transmitted to the contactless IC card at 10% ASK on the carrier; A power amplifier for power amplifying the signal modulated by the modulator; A B-type contactless IC card reader comprising a low pass filter for low pass filtering the power amplified signal and radiating it through an antenna. The method according to claim 1 or 2, wherein the receiving means, A first bandpass filter for receiving a signal received through an antenna and selectively passing only a frequency band obtained by adding a frequency of a carrier wave and a frequency of a subcarrier; A subcarrier detection circuit for detecting a subcarrier BPSK signal from the signal passing through the first bandpass filter; A second bandpass filter for selectively passing only a subcarrier frequency band among the detected subcarrier BPSK signals; A level comparator for converting the signal passing through the second band pass filter into a digital signal compared with a reference voltage; A subcarrier detector for outputting a detection signal by checking whether the frequency of the digitized signal in the level comparator is a subcarrier frequency; A subcarrier synchronization unit receiving the detection signal from the subcarrier detection unit and synchronizing an internal clock with the received subcarrier BPSK signal; And a BPSK / NRZ converter converting the subcarrier BPSK signal synchronized with the internal clock by the subcarrier synchronization unit to an NRZ signal and transmitting it to the control means.