JP3401645B2 - Magnetic card reader / writer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic card used as a prepaid card such as a traffic card, a membership card and a leisure card, and more particularly to a magnetic card reader / writer for writing and reading recorded data.

[0002]

2. Description of the Related Art A conventional magnetic card reader / writer will be described with reference to FIG. This magnetic card reader / writer has a reference clock generation circuit 31 for generating a reference clock 32 and a counter circuit 33 for counting the reference clock 32, and magnetic recording data of a magnetic card recorded by the F2F frequency modulation recording method. When reading, the counter circuit 33 counts one bit of the recording data with the reference clock 32, and the counter signal 34 is supplied to the first to third determination position designating circuits 35, 37, 39.
The first judgment position designating circuit 35 generates a first judgment position signal 36 for designating a position of about 75% of the previous 1-bit length for every 1 bit of the recording data. Second determination position designation circuit 3
7 generates a second determination position signal 38 for designating the forward position by about 10% bit length with respect to the first determination position signal 36 of the first determination position designating circuit 35. The third determination position designating circuit 39 generates a third determination position signal 40 which designates a rear position by about 10% bit length with respect to the first determination position signal 36 of the first determination position designating circuit 35. . These first, second, and third determination position signals are selected by the selection circuit 42 according to the selection signal 41 input from the outside, and output as the determination position signal 43.

The judgment of the recording data is made bit by bit using the selection judgment position signal 43. In the recording data recorded by the F2F frequency modulation recording method, as shown in FIG. 4, data “0” is not inverted between 1-bit data (FIG. 4 (1)), and data “1” is 1-bit data. 1 / long
It is reversed at position 2 (Fig. 4 (2)). As a result, the selection signal 41 externally input from the selection circuit 42
The selection determination position signal 43 selected by determines whether the recording data is "1" or "0".

[0004]

In such a conventional magnetic card reader / writer, the recording data has a prescribed F depending on the situation when the recording data is written in the magnetic card.
The data may not be written according to the 2F frequency modulation recording method. For example, when the reversal position of the recording data is changed due to the jitter of the recording magnetic head or when the speed fluctuation is large during the manual operation of the magnetic card, the recording data is not reversed at the correct position (FIG. 4 (3), (4)
reference). When the magnetic card recorded in such a state is read, the recorded data cannot be correctly determined and erroneous reading is performed, which is a problem in use. In order to solve this problem, it has been attempted to select a judgment position signal by an external selection signal to make a judgment, but a fluctuation of the recording data is detected in the recording data of one magnetic card and the selection signal is selected. Since it is necessary to perform the operation of selecting the judgment position signal by the selection signal after reading the magnetic card and reading it again, there is a problem that the reading operation is complicated and takes a long time. It was

Therefore, the present invention eliminates the above-mentioned drawbacks of the conventional magnetic card reader / writer and provides a function of accurately determining the recorded data, so that the position of the recorded data may change during reading or the magnetic card may run. The object of the present invention is to provide a magnetic card reader / writer capable of making a correct determination by determining data at a plurality of determination positions and determining data at an optimum data determination position even when the speed fluctuation is large. To do.

[0006]

According to the present invention, the F2F
In a demodulation circuit of a magnetic card reader / writer for reading magnetic recording data of a magnetic card recorded by a frequency modulation recording method, a plurality of judgment position designating circuits for specifying a data judgment channel of the recording data for each bit of the recording data. When,
A plurality of data judgment circuits for judging the magnetic recording data at the judgment positions designated by the outputs of these judgment position designating circuits, and a 1-bit long / short fluctuation of the recording data is judged from the outputs of these data judgment circuits. And a selection signal generation circuit for setting a signal for selecting a data determination position output signal to be output as the magnetic recording data from the plurality of outputs from the data determination circuit at the plurality of determination positions, and the selection signal generation circuit. There is provided a magnetic card reader / writer, comprising: a selection circuit that selects the data determination position signal based on an output from the circuit.

Further, according to the present invention, the plurality of determination position designating circuits include a first determination position designating circuit and the first determination position designating circuit.
A second judgment position specifying circuit for specifying a data judgment position at a front position with respect to the data judgment position of the judgment position specifying circuit;
A third determination position designating circuit that designates a data determination position at a position behind the data determination position of the first determination position designating circuit, and a third determination position designating circuit that designates a data determination position at a position ahead of the second determination position designating circuit. The first, second, third, and fourth data determination circuits have four determination position designating circuits, and each of the plurality of data determination circuits makes a data determination corresponding to the output of each determination position designating circuit. A magnetic card reader / writer is provided that includes a circuit.

Further, according to the present invention, in the first decision position designating circuit, the data decision position is set to about 75 bits which is one bit long before.
% Position, and the second determination position designating circuit determines that the first determination position designating circuit has a data determination position of about 1
Specify the data judgment position at the forward position by 0% bit length,
The third determination position designating circuit designates a data determination position at a position backward by a bit length of about 10% of the first determination position designating circuit data determination position, and the fourth determination position designating circuit designates the data determination position. Second determination position designating circuit First, second, which designates a data determination position at a position ahead of the data determination position by a bit length of about 10%, and makes a determination corresponding to the output of each determination position designating circuit. There is provided the magnetic card reader / writer characterized in that the magnetic card reader / writer comprises a third and a fourth data judging circuit.

[0009]

According to the magnetic card reader / writer of the present invention, in the demodulation circuit, in addition to the predetermined position signal for specifying the data judgment position of the recording data, the judgment position is specified in front of and behind this predetermined position signal. A plurality of judgment position designating circuits for generating the second, third and fourth position signals and a circuit for generating a selection signal by the output of the plurality of data judgment circuits are provided. Since the signal is selected, the print data can be correctly determined regardless of the positional deviation of the print data.

At the time of reading data, even if there is a position variation in the recorded data or a large velocity variation in running a magnetic card, the data is determined at a plurality of determination positions and the data is determined at the optimum data determination position. Since the determination is made, the recording data can be correctly determined regardless of the presence of the positional deviation.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the magnetic card reader / writer of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram showing a configuration of a judgment position designating circuit in a magnetic card reader / writer demodulation circuit of the present invention. The reference clock generation circuit 1 generates a reference clock 2 faster than the frequency of the human power data, and the counter circuit 3 uses this reference clock 2 to count one bit of the recording data. Judgment position designating circuits 5, 7,
9 and 11 are supplied. The first determination position specifying circuit 5 is
A first determination position signal 6 for designating a position of about 75% of the previous 1-bit length is generated for each 1-bit of the recording data. The second determination position designating circuit 7 generates a second determination position signal 8 for designating the forward position by about 10% bit length with respect to the first determination position signal 6 of the first determination position designating circuit 5. To do. The third determination position designating circuit 9 includes the first determination position designating circuit 5
The third determination position signal 10 designating the rear position by about 10% bit length is generated with respect to the first determination position signal 6 of. The fourth determination position designation circuit 11 is a fourth determination position signal 12 for designating the forward position by about 10% bit length with respect to the second determination position signal 8 of the second determination position designation circuit 7.
To occur.

The first judgment position signal 6 is supplied to a first data judgment circuit 13 to which a recording data signal 21 is supplied, and a first judgment signal 14 indicating the result of data judgment is generated at the output side thereof. To be done. The second determination position signal 8 is the second data determination circuit 15 to which the recording data signal 21 is supplied.
Is supplied to the output side, and shows the judgment result of the data,
The second decision signal 16 is generated. The third determination position signal 10 is supplied to a third data determination circuit 17 to which a recording data signal 21 is supplied, and a third determination signal 18 indicating the result of data determination is generated at the output side thereof. . The fourth determination position signal 12 is supplied to the fourth data determination circuit 19 to which the recording data signal 21 is supplied, and the fourth determination signal 20 indicating the result of data determination is generated at the output side thereof.

These first to fourth data judging circuits 1
The first to fourth determination signals 14, 16, 18, and 20 which are the outputs of 3, 15, 17, and 19 are supplied to the selection signal generation circuit 22, and the result is output as the selection signal 23 and supplied to the selection circuit 24. To be done. The first to second determination position signals 6 and 8 supplied to the selection circuit 24 are selected by the selection signal 23 and output as the selection determination position signal 25.

FIG. 2 is a waveform diagram for explaining the operation of judging the recording signal using the judgment position designating circuit shown in FIG. FIG. 2A is a waveform diagram of recording data, where (1) and (2) show data "0" and "1", respectively, and (3) and (4) show data "0" and "0", respectively. 1 "indicates a state in which the data length has become short because the card running speed has suddenly increased.

2 (B), (D), (F) and (H),
First to fourth determination position designating circuits 5, 7, 9,
11 shows the first to fourth determination position signals 6, 8, 10, and 12, which are output signals of 11. The first determination position signal 6 is generated at a position of about 75% of the 1-bit length of the previous data for each 1-bit of the recording data. The second determination position signal 8 is
The first determination position signal 6 is generated at the front position by about 10% bit length. The third determination position signal 10 is the first
With respect to the judgment position signal 6 of No. 3, the signal is generated at a rear position by about 10% bit length. The fourth determination position signal 12 is generated at a position ahead of the second determination position signal 8 by about 10% bit length.

These first to fourth judgment position signals 6,
When the recorded data is judged by 8, 10, and 12, the first to third data judgment signals 14, 16 are applied to the data recorded in the regular position (FIGS. 2A and 2B). ,
Since 18 outputs the same determination result, the selection signal generation circuit 22 outputs the selection signal 23 of "0", the selection circuit 24 selects the first determination position signal 6, and the selection determination position signal 25 Is output as. When the recording data length is suddenly shortened because the card traveling speed is suddenly increased (FIGS. 2 (3) and (4)), first, FIG.
Although the first to third data determination signals 14, 16 and 18 output the same determination result, the third determination position designation signal 1
Since 0 is not output in the 1-bit data signal, the selection determination position signal 2 at the time of the next data signal (FIG. 2 (4))
5 outputs the second determination position signal 8 when the selection signal 23 selects "1". Similarly, the third data determination signal 18
The same is true when only different judgment results are obtained.

On the other hand, when the card running speed suddenly decreases, the first, second and fourth data judgment signals 14,
When 16 and 20 output the same determination result or output different determination results only for the data determination signal 20, the selection signal 23 selects "0" as the selection position signal 25 for the next data signal. And outputs the first determination position signal 6.

In the above-mentioned embodiment, there are four judgment circuits for data judgment depending on the recording data judgment position and the data judgment position, and two judgment position signals are selected by the selection circuit. It is possible to guarantee the quality of the recording data and improve the reliability of reading the recording data by selecting an appropriate value without being limited to the above value.

Further, in the above embodiment, the positions of the second and third determination position signals 8 and 10 are arranged at positions displaced by about 10% from the first determination position signal, but they are not necessarily 10%. In addition, the position of the fourth determination position signal 12 is arranged at a position deviated from the position of the second determination position signal 8 by about 10%. The reading margin of the recorded data during running,
The quality of the recorded data can be guaranteed and the reliability of reading the recorded data can be improved by selecting an appropriate value in consideration of the read margin of the recorded data with respect to the speed fluctuation when the magnetic card is manually driven.

[0020]

As described above, according to the present invention, every 1 bit of the recording data recorded on the magnetic card,
A plurality of judgment position designating circuits for designating the data judgment positions of the recording data, and a plurality of data judgment circuits for judging the magnetic recording data at the judgment positions designated by the outputs of these judgment position designating circuits; By providing a selection signal generating circuit that sets a signal for selecting a data determination position output signal from the output of the data determination circuit, and a selection circuit that selects the data determination position signal by the output from the selection signal generating circuit, It is possible to obtain a highly accurate magnetic card reader / writer that is not affected by fluctuations in the running speed of magnetic cards, changes in ambient temperature, variations in magnetic cards used, and the like. That is, in the magnetic card reader / writer of the present invention, the data read determination position of the magnetic card is automatically selected and the data is determined at the optimum data determination position. Therefore, the reread operation is performed like the conventional magnetic card reader / writer. It became possible to read quickly without any need.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a determination position specifying unit and a data determination unit in a demodulation circuit of a magnetic card reader / writer according to the present invention.

FIG. 2 is a waveform diagram for explaining an operation of determining a recording signal using the determination position specifying circuit and the data determination circuit of the magnetic card reader / writer of the present invention.

FIG. 3 is a block diagram showing a configuration of a determination position in a demodulation circuit of a conventional magnetic card reader / writer.

FIG. 4 is a waveform diagram for explaining an operation of determining a recording signal using a demodulation circuit of a conventional magnetic card reader / writer.

[Explanation of symbols]

1, 31 Reference clock generation circuit 2, 32 reference clock 3, 33 Counter circuit 4, 34 Counter signal 5, 35 First judgment position designating circuit 6, 36 First judgment position signal 7, 37 Second determination position designation circuit 8, 38 Second judgment position signal 9, 39 Third judgment position designation circuit 10, 40 Third judgment position signal 11 Fourth judgment position designation circuit 12 Fourth judgment position signal 13 First data determination circuit 14 First judgment signal 15 Second data determination circuit 16 Second judgment signal 17 Third Data Judgment Circuit 18 Third judgment signal 19 Fourth data determination circuit 20 Fourth judgment signal 21 Recording data signal 22 Selection signal generation circuit 23, 41 selection signal 24, 42 selection circuit 25, 43 Selection judgment position signal

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G11B 20/10 G11B 20/14 G11B 20/18 G06K 7/08 H04L 25/00

Claims (3)

(57) [Claims] 1. A demodulation circuit of a magnetic card reader / writer for reading magnetic recording data of a magnetic card recorded by an F2F frequency modulation recording method, wherein a plurality of data specifying channels for recording data are designated for each bit of the recording data. and pieces of position determination specifying circuit, a plurality of data determination circuit for determining the magnetic recording data in the determination position designated by the output of the determination position designation circuit, of the recording data from the outputs of these data decision circuit 1
Judgment of bit length fluctuations can be made at multiple judgment positions.
From the plurality of outputs from the data determination circuit of
A selection signal generating circuit for setting a signal for selecting a data determination position output signal to be output as recording data; and a selection circuit for selecting the data determination position signal by an output from the selection signal generating circuit. Magnetic card reader / writer. 2. The plurality of determination position designating circuits include a first
Determination position designating circuit, a second determination position designating circuit that designates a data determination position at a front position with respect to the data determination position of the first determination position designating circuit, and data determination of the first determination position designating circuit. A third judgment position specifying circuit for specifying a data judgment position at a position behind the position, and a fourth judgment position specifying circuit for specifying a data judgment position at a position in front of the second judgment position specifying circuit.
The first, second, third, and fourth data judgment circuits each of which has a judgment position designating circuit, and each of the plurality of data judgment circuits makes a data judgment corresponding to an output of each judgment position designating circuit. The magnetic card reader / writer according to claim 1, further comprising: 3. The first determination position designating circuit designates a data determination position at a position of about 75% of the previous 1-bit length, and the second determination position designating circuit designates the first determination position circuit. The data judgment position is specified by a position ahead of the data judgment position by a bit length of about 10%, and the third judgment position specifying circuit causes the first judgment position specifying circuit to determine about 10% of the bits of the data judgment position. The data determination position is designated by the backward position for a long time, and the fourth determination position designating circuit designates the data determination position by the forward position by a bit length of about 10% of the second determination position designating circuit data determination position. At the same time, the first, second, and
The magnetic card reader / writer according to claim 2, wherein the magnetic card reader / writer comprises a third and a fourth data determination circuit.