JPH0620109A - Data processor using non-contact data carrier - Google Patents

Abstract

PURPOSE:To evade beforehand the occurrence of the disabling of a communication due to the power interruption of a data carrier during a reading operation, regarding a data processor using a non-contact carrier to be used for the toll utilization, etc., of facilities or equipments. CONSTITUTION:When the control part 22 from a reader/writer 10 to a data carrier 20 decides the reception of a prescribed command, a preliminarily fixed pseudo random signal is returned from a pseudo random signal generation part 23. The correlation arithmetic part 13 of the reader/writer 10 determines a self-correlation peak value when the reference signal which is the same as the pseudo random signal of the data carrier 20 and a reception signal coincide, this self-correlation peak value is compared with the preliminarily fixed threshold in a comparison part 15, and a reading control part 12 executes the reading operation when the peak value becomes more than the threshold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data processing device using a non-contact data carrier used for paid use of facilities and equipment.

[0002]

2. Description of the Related Art Conventionally, as a data processing device using a non-contact data carrier known as a so-called data coin, which is used for a fee-based use in a ski lift, a play facility, etc., for example, one shown in FIG. 8 is known. ing. In FIG.
Reference numeral 10 is a reader / writer, and 20 is a data carrier. The reader / writer 10 is fixedly installed and includes a controller 11, a read controller 12, a correlation calculator 13, and a transmitter 14. The data carrier 20 is carried by a user as, for example, a pendant or a wrist watch, and includes a non-volatile memory 21, such as an E ² PROM, a control unit 22, a pseudo random signal generation unit 23, a transmission unit 24, and a power supply circuit unit 25. .

In the operation of such a data processing apparatus, when the data carrier 20 is brought close to the communicable distance of the reader / writer 10, for example, the operating power is supplied from the transmission section 14 of the reader / writer 10 by electromagnetic inductive coupling.
0 is received by the transmission section 24, the received signal is rectified and smoothed by the power supply circuit section 25, and the capacitor C is charged with the power supply voltage Vcc to operate.

In this state, when the read control unit 12 of the reader / writer 10 issues a read command of the ID number to release the access prohibition of the memory 21, that is, to open the key, the control unit 22 of the data carrier 20 causes the reader to read. The command content from the writer 10 is decoded, and the ID number stored in the memory 21 is read. For returning read data, for example, a pseudo-random sequence to be used is determined in advance corresponding to data bits 1 and 0, and a pseudo-random generating unit 23 generates a pseudo-random sequence according to the bits of the read data, and the transmitting unit 24 Sent to the reader / writer 10.

The correlation calculation unit 13 of the reader / writer 10 includes
The same pseudo-random signal as that of the data carrier 20 is held as a reference signal, and the autocorrelation with the received signal is obtained. When the received signal and the reference signal match, the autocorrelation value increases in a peak, and bit 1 or 0 The reception of can be determined.

[0006]

However, in the data processing device using such a non-contact data carrier, since the data carrier 20 is supplied with operating power by the reader / writer 10, the data carrier 20 is supplied from the reader / writer 10. When an arbitrary command is issued to obtain a response from the data carrier 20 by a pseudo random signal, the operating power of the data carrier 20 is insufficient and power cutoff occurs during the return of data using the pseudo random sequence. I was afraid to do it.

The present invention has been made in view of the above-mentioned conventional problems, and data using a non-contact data carrier for performing a reliable read operation by determining the operating power state of the data carrier. An object is to provide a processing device.

[0008]

To achieve this object, the present invention is constructed as follows. First, the present invention is directed to a data processing device using a non-contact data carrier for writing data or reading data from the reader / writer to the data carrier by non-contact coupling.

In the present invention as such a data processing device, the data carrier is provided with a response means for returning a predetermined pseudo random signal when a predetermined command is received from the reader / writer. Further, the reader / writer has a correlation calculation means for obtaining an autocorrelation between the same signal as the pseudo random signal of the data carrier and the received signal, and an autocorrelation peak value obtained by the correlation calculation means when the received signal and the reference signal match. And a read control means for executing a read operation when the threshold value is equal to or more than a predetermined threshold value.

The reading control means of the reader / writer has a first threshold value TH1 and a second threshold value TH2 smaller than the first threshold value TH1, and the autocorrelation peak value obtained by the correlation calculating means is the first threshold value T.
If it is H1 or more, the read operation is executed, and if the autocorrelation peak value is smaller than the first threshold value TH1 and is the second threshold value TH2 or more, the autocorrelation peak value obtained from the pseudo-random signal returned from the data carrier when the command is issued. The comparison process may be repeated, and if the autocorrelation peak value is smaller than the second threshold value TH2, the read operation may be stopped.

Further, as the reading control means of the reader / writer, a differential coefficient showing the time change of the previous and present autocorrelation peak values is obtained, and if the differential coefficient is positive, the autocorrelation peak value tends to increase. Threshold value T determined and determined in advance
The comparison process with H (= TH1) is repeated, and the read operation is executed when the autocorrelation peak value becomes equal to or higher than the threshold value TH, while the autocorrelation peak value tends to decrease when the differential coefficient is negative. It is also possible to judge and stop the read operation.

[0012]

According to the data processing device using the non-contact data carrier of the present invention having such a configuration, when the data carrier is read, a pseudo random signal is sent back to check the operating power by issuing a command. To find the autocorrelation. Since the autocorrelation value is the sum of the values obtained by multiplying the received sequence and the reference sequence of the pseudo-random signal, the autocorrelation peak value obtained when the received sequence and the reference sequence match is a value proportional to the power of the received signal. Is. The received signal is inversely proportional to the square of the distance. The amplitude of the transmission signal on the data carrier is proportional to the power supply voltage.

Therefore, if the autocorrelation peak value is equal to or higher than a predetermined threshold value, the power supply voltage of the data carrier can be estimated to be a voltage sufficient for the read operation, and the reader / writer executes the read operation. On the contrary, if the peak value of autocorrelation is smaller than the threshold value, it can be estimated that the power supply voltage of the data carrier is insufficient, and either the recovery is waited or the read operation is stopped and the power is cut off during the read operation. Can be avoided in advance.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of an embodiment showing one embodiment of the present invention. In FIG. 1, 10 is a reader / writer,
A control unit 11 using an MPU, a read control unit 12, a correlation calculation unit 13, a transmission unit 14, and a comparison unit 15 are provided. Reference numeral 20 denotes a data carrier, which is a non-volatile memory 21 such as an E ² PROM, a control unit 22 that performs command determination and control based on the determination result, a pseudo random signal generation unit 23, and a transmission unit 2.
4. A power supply circuit unit 25 is provided.

In this embodiment, electromagnetic inductive coupling using a coil is used as the non-contact coupling by the transmission units 14 and 24 provided in the reader / writer 10 and the data carrier 20. FSK modulation is used for data transmission from the reader / writer 10 to the data carrier 20. In addition, a pseudo random signal is transmitted as a spread spectrum communication method for data transmission from the data carrier 20 to the reader / writer 10.

An M-sequence signal is used as the pseudo-random signal. The transmission unit 14 of the reader / writer 10 constantly outputs the FSK modulated signal corresponding to the data bit 0 to the communicable area, and when the data carrier 20 enters the communicable area, the transmission unit 24 indicates the data bit 0. The power supply voltage Vcc can be obtained by receiving the FSK signal, rectifying and smoothing it in the power supply circuit 25 and charging the capacitor C.

The pseudo random signal generator 23 provided in the data carrier 20, as shown in FIG. 2, corresponding to M _0-sequence signal generator 26 and the data bit 1 for generating a M ₀ sequence example corresponding to the data bit 0 comprises M _1-sequence signal generator 27 for generating the M ₁ sequence signals. M _0-sequence signal is given a bit data to be returned for generator 26 and M ₁ sequence signal generator 27, M _0-sequence signal generator 26
Is inverted and given by the inverter 28.
In addition, the M ₀ series signal generator 26 and the M ₁ series signal generator 27
Is output to the transmission unit via the OR gate 29.

Here, the M ₀ and M ₁ sequence signal generator 2
6, 27 operates so as to generate a series signal when the input data bit is 1. Therefore, when the input data bit is 0, the inverter 28 inverts the M ₀ series signal generator 26 to operate. On the other hand, when the input data bit is 1, the M ₁ series signal generator 27 operates.

As the M ₀ series signal and the M ₁ series signal,
For example, one having a sequence length of 511 word length (bit length) is used, and each sequence element is sequentially output in synchronization with the clock. FIG. 3 shows the configuration of the correlation calculation unit 13 provided in the reader / writer 10 of FIG. In FIG. 3, the correlation calculation unit is provided on the demodulation side of the data bit 0 and the demodulation side of the data bit 1.
The same circuit is provided for the system. That is, the shift registers 30 and 40, the sum-of-products arithmetic units 31 and 41, and the reference value register 3 for each system of the data bits 0 and 1.
2, 42 and comparators 33, 43 are provided.

Received signals, that is, received sampling data, are sequentially input to the shift registers 30 and 40. The number of stages of the shift register 30 has 511 shift stages corresponding to the sequence length of each sequence signal generated by the M ₀ and M ₁ sequence signal generators 26 and 27 shown in FIG. 2, for example, 511 words. The reference value registers 32 and 42 fixedly hold the M ₀ series signal and the M ₁ series signal generated in the data carrier. The reference series signal may be held by a memory instead of a register or a fixed circuit such as a wired logic.

The product-sum calculators 31 and 41 are the shift register 3
0, 40 reception sequence and M of reference value registers 32, 42
₀ , M₁ The product-sum operation with each reference series of is performed. That is, the receiving system
Multiply the columns and each series element of the reference series to find the sum
To calculate the autocorrelation value. Of the product-sum calculators 31 and 41
The correlation value output is given to the comparators 33 and 43. M
₀ , M₁ The autocorrelation value of the sequence signal is as shown in Fig. 4.
It FIG. 4 shows that M-sequence signals of sequence length n are continuously received and received.
It shows the correlation value when calculating the optical correlation, and
It is a value of-(1 / n) until the reference value series match.
However, if both match, the autocorrelation peak value indicated by relative value 1
Is obtained.

The comparators 33 and 43 in FIG. 3 judge the autocorrelation peak value shown in FIG. When the comparator 33 determines the autocorrelation peak value, it outputs bit 0, and when the comparator 43 determines the autocorrelation peak value, it outputs bit 1. Referring again to FIG. 1, in the present invention, the reader / writer 10
Prior to the reading of the data carrier 20 from the read control unit 12 provided in the above, a predetermined command is issued to cause the pseudo random signal generation unit 23 to return an M ₀ series signal corresponding to, for example, bit 0, and the correlation calculation unit 13 The comparison section 15 determines the autocorrelation peak value from the above to determine whether the operating power of the data carrier 20 is sufficient, and the read control section 12 executes the read operation based on the result.

FIG. 5 is a read control section 12 and a comparison section 1 which operate as read control means provided in the reader / writer 10 of FIG.
5 is a flowchart showing a first embodiment of a control process for checking the operating power of the data carrier 20 according to No. 5. In FIG. 4, the read control unit 12 of the reader / writer 10 first issues a command in step S1, for example, a test command for requesting a response from the data carrier 20, in a constant cycle under the instruction from the control unit 11.

When the data carrier 20 enters the receivable range of the reader / writer 10, the FSK by non-contact coupling is performed.
The modulation signal is received and the power supply voltage Vcc is supplied from the power supply circuit unit 25.
You will get The activated data carrier 20 receives the command issued by the reader / writer 10 in step S1, and when the control unit 22 determines that the command is a test command, for example, it instructs the pseudo random signal generation unit 23 to respond to bit 0. .

Bit 0 for this test command means that, for example, the memory 21 is in an access prohibited state. On the other hand, when the memory 21 is in the access permitted state, bit 1 is returned. Pseudo-random signal generator 23 which receives a return instruction of bit 0 from the controller 22
Activates the M _0-sequence signal generator 26 as shown in FIG. 2, sends back from the transmission unit 24 to M _0-sequence signal.

In this state, when the response of the pseudo-random sequence signal is received in step S2, the process proceeds to step S3, in which the correlation calculation unit 13 receives the received signal and each reference sequence signal of M ₀ and M ₁ by the circuit configuration shown in FIG. Calculate the autocorrelation peak value between and. The outputs of the product-sum calculators 31 and 41 are given to the comparison unit 15, and it is determined whether or not they are equal to or more than a predetermined threshold value TH as shown in step S4.

Here, since the data carrier 20 returns the M ₀ series signal by bit 0, the product-sum calculator 31
Output becomes a peak value as shown in FIG. 5 when the reception of the M ₀ series signal is completed, and exceeds the threshold value TH. The result of this comparison is provided to read control unit 12, which determines that power supply voltage Vcc of data carrier 20 is at a voltage sufficient for the read operation, permits read, and executes read access in step S6. To do.

On the other hand, when the autocorrelation peak value does not exceed the threshold value TH, the power supply voltage Vcc of the data carrier 20 is insufficient, so in this embodiment, the procedure returns to step S1 to reissue the test command. , A corresponding pseudo-random sequence is sent back, and the obtained autocorrelation peak value is set to a threshold value T.
The process of comparing with H is repeated. Of course, if the autocorrelation peak value does not exceed the threshold value TH even after a certain period of time, the access may not be performed and the reading may be stopped.

FIG. 6 is a flow chart showing a second embodiment of the control processing of the present invention for judging the operating power of the data carrier. In the embodiment of FIG. 6, the autocorrelation peak value is calculated from the pseudo-random signal obtained as a response to the command issuance in FIG. 3 and then the first threshold value TH1 and the second threshold value TH2 smaller than that are compared. Is going.

For example, in step S4, the autocorrelation peak value is first compared with the smaller threshold value TH2. If the threshold value is TH2 or more, the process proceeds to step S5 to be compared with the larger threshold value TH1. It is determined that the power supply voltage Vcc is sufficient, the read is permitted in step S6, and the read access is executed in step S7.

On the other hand, if the autocorrelation peak value is greater than or equal to the smaller threshold TH2 in step S4 but smaller than the larger threshold TH1 in step S5, step S1.
The comparison process of steps S1 to S5 is repeated. Further, when the correlation peak value is smaller than the smaller threshold value TH2 in step S4, the process proceeds to step S8 and the read operation is stopped.

FIG. 7 is a flow chart showing a third embodiment of the control processing of the present invention for estimating the operating power of the data carrier. In this embodiment, the autocorrelation obtained from the response by issuing the test command. It is characterized in that the differential coefficient showing the time change of the autocorrelation peak value is obtained and judged from the difference between the previous peak value and the current peak value. That is, in the flowchart of FIG. 7, the current autocorrelation peak value C _n is obtained from the response of the data carrier to the issuance of the test command in step S3, and then the previous autocorrelation peak value already detected in step S4. The differential coefficient ΔC is obtained as the difference from C _n-1 .

ΔC = C _n-1 -C _{n In} step S5, it is checked whether the differential coefficient ΔC of the autocorrelation peak value obtained in step S4 is positive or negative. If the differential coefficient ΔC is positive, In step S6, the threshold value TH1 is compared with a predetermined threshold value TH1. This threshold TH1 is shown in FIG.
Is the same as the first threshold value TH1 used in the second embodiment, and if the threshold value is equal to or higher than the threshold value TH1, it is determined that the power supply voltage Vcc of the data carrier is sufficient, and the read is permitted, and the read access is performed in step S8. Run.

If it is smaller than the threshold value TH1, the comparison process based on the calculation of the differential coefficient in steps S1 to S5 is repeated. Here, in the second embodiment of FIG. 6, the reading is stopped if the autocorrelation peak value is smaller than the second threshold value TH2 which is smaller than the first threshold value TH1, but in the third embodiment, the autocorrelation peak value is stopped. Even if the value is smaller than the second threshold value TH2, if the differential coefficient ΔC is positive, the autocorrelation peak value tends to increase, and it is considered that the threshold value TH1 will eventually be reached during repeated reading by issuing the test command. The comparison process is repeated without stopping.

On the other hand, when the differential coefficient is negative in step S5, it can be seen that the autocorrelation peak value tends to decrease. If access is continued as it is, communication will eventually become impossible, so the read operation is stopped in step S9. To do. Although the above-described embodiment has been described by taking non-contact transmission by electromagnetic induction coupling using a coil as an example, an optical transmission method or a wireless transmission method may be used instead. Furthermore, although the M-sequence signal is taken as an example of the pseudo-random signal, an appropriate pseudo-random signal can be used in addition to this.

Further, in the above-mentioned embodiment, the psuedo-random signals unique to the data bit 0 and the data bit 1 are respectively used, that is, the M ₀ series signal and the M ₁ series signal are used. Prepare the M-sequence signal only for 1,
For data bit 0, the transmission of the M-sequence signal may be stopped.

[0037]

As described above, according to the present invention, the reader / writer sends a predetermined command before reading the data carrier to return a specific pseudo-random signal from the data carrier, and the received signal and the reference signal. By checking the peak value of the autocorrelation when the signals match, it is possible to determine whether the operating power of the data carrier is appropriate or insufficient.If the operating power is appropriate, the read operation is executed, and if it is insufficient, Since it sees the situation and stops the operation, it is possible to surely prevent the problem that the power of the data carrier is cut off during the read operation.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a pseudo random signal generator provided on the data carrier of FIG.

FIG. 3 is an explanatory diagram of a correlation calculation unit provided in the reader / writer of FIG.

FIG. 4 is an explanatory diagram of an autocorrelation value of a pseudo random signal.

FIG. 5 is a flowchart showing a first embodiment of the control processing of the present invention.

FIG. 6 is a flowchart showing a second embodiment of the control processing of the present invention.

FIG. 7 is a flowchart showing a third embodiment of the control processing of the present invention.

FIG. 8 is an explanatory diagram of a conventional device.

[Explanation of symbols]

10: data carrier 11, 22: control unit (MPU) 13: correlation calculation unit 14, 24: transmission unit 15: comparison unit 20: data carrier 21: memory (E ² PROM) 23: pseudo random signal generation unit 25: power supply Circuit part 26: M ₀ series signal generator 27: M ₁ series signal generator 28: Inverter 29: OR gate 30, 40: Shift register 31, 41: Sum of products calculator 32, 42: Reference value register 33, 43: Comparator

Claims (3)

[Claims] 1. A data processing device using a non-contact data carrier for writing data to or reading data from a reader / writer by non-contact coupling to the data carrier, wherein a predetermined command is issued to the data carrier from the reader / writer. Provided with a response means for returning a predetermined pseudo-random signal when receiving, the reader / writer, a correlation operation means for obtaining an autocorrelation between the same signal as the pseudo-random signal of the data carrier and the received signal, And a read control means for executing a read operation when the autocorrelation peak value when the received signal obtained by the correlating means and the reference signal are equal to or more than a predetermined threshold value is provided. A data processing device using a data carrier. 2. A data processing apparatus using a non-contact data carrier according to claim 1, wherein the reading control means of the reader / writer has a first threshold value TH1 and a second threshold value T smaller than the first threshold value TH1.
H2, and if the autocorrelation peak value obtained by the correlation calculation means is equal to or greater than the first threshold value TH1, a read operation is executed and the autocorrelation peak value is smaller than the first threshold value TH1.
If the threshold value is equal to or higher than the threshold value TH2, the comparison process of the pseudo random signal returned from the data carrier with the issue of the command and the autocorrelation peak value of the received signal is repeated. If the autocorrelation peak value is smaller than the second threshold value TH2, the read operation is stopped. A data processing device using a non-contact data carrier. 3. A data processing apparatus using the non-contact data carrier according to claim 1, wherein the reading control means of the reader / writer produces a differential coefficient indicating a temporal change of the previous and present autocorrelation peak values. If the differential coefficient is positive, it is determined that the autocorrelation peak value is on the increase, and the comparison processing with the predetermined threshold value TH is repeated. When the autocorrelation peak value becomes equal to or larger than the threshold value TH, the reading is performed. A data processing apparatus using a non-contact data carrier, which performs an operation and further judges that the autocorrelation peak value tends to decrease when the differential coefficient is negative and stops the read operation.