JPH0660557A - Magnetic card reader writer - Google Patents

Abstract

PURPOSE:To obtain a high-accuracy magnetic card reader writer which is not affected by use environment by providing a comparison and decision circuit comparing and deciding plural data decision signals obtained by deciding recording data by majority decision. CONSTITUTION:A 1st data decision circuit 11 decides the recording data 19 according to a 1st decision position signal 6 and generates a 1st data decision signal 12. Similarly, 2nd and 3rd data decision circuits 13 and 15 generate 2nd and 3rd data decision signals 14 and 16. The signals 12, 14 and 16 are supplied to a confirmation and decision circuit 17. Since the signals 12, 14 and 16 are confirmed and decided by majority decision in the circuit 17, the data decision signal having large number out of the data decision signals showing the same decided result among the 1st to the 3rd signals 12, 14 and 16 is fetched to the output side of the circuit 17 as decision data 18. By providing plural data decision circuits 11, 13 and 15 and the comparison and decision circuit comparing and deciding the obtained decision signals 12, 14 and 16 by majority decision, the high-accuracy magnetic card reader writer which is not influenced by the use environment is obtained.

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. The conventional magnetic card reader / writer has a reference clock generation circuit 31 for generating a reference clock 32, a counter circuit 33 for counting the reference clock 32, and a determination position for specifying a data determination position by a counter signal 34 from the counter circuit 33. Designation circuit 35 and determination position signal 36 from determination position designation circuit 35
A data judgment circuit 38 for judging the recording data 37 by
When reading the magnetic recording data (recording data 37) of the magnetic card recorded by the F2F frequency modulation recording method, the counter circuit 33 first sets 1 of the recording data 37.
The bit count is counted by the reference clock 32, and the counter signal 34 is generated. Next, by using this counter signal 34, about 1 bit length of about 7
Judgment position signal 3 that specifies the data judgment position at the 5% position
6 is generated by the judgment position designating circuit 35. And
Using this judgment position signal 36, the data judgment circuit 38 judges the data bit by bit of the recording data 37, and the judgment data 39 is obtained as the judgment result of the recording data 37.

Magnetic recording data (recording data 37) of a magnetic card recorded by the F2F frequency modulation recording system is shown in FIG.
As shown in Fig. 4, the data "0" is not inverted during the 1-bit length (Fig. 4 (1)), and the data "1" is inverted at the 1/2 position of the 1-bit length (Fig. 4 (2)). As a result, the judgment position designating circuit 35 sends the recording data 37
The data judgment circuit 38 judges whether the recording data 37 is "1" or "0" using the judgment position signal 36 generated at a position of about 75% of the 1-bit length for each 1 bit.

[0004]

In such a conventional magnetic card reader / writer, even if the recording data written in the magnetic card is written in accordance with the prescribed F2F frequency modulation recording method, the magnetic card reader / writer. The recording data may be affected by noise due to the environment in which the writer is used (see FIG. 4C). When the recorded data is read in this state,
The recorded data could not be correctly judged, resulting in incorrect reading, which was a problem in use. Also, conventionally, 1 of the recorded data
A magnetic card reader having a plurality of judgment position designating circuits for designating data judgment positions of recording data for each bit, and judging the magnetic recording data at the judgment positions designated by the outputs of these judgment position designating circuits. Writer is also known, but it was not used for the purpose of preventing the influence of noise.

Therefore, the present invention eliminates the above-mentioned drawbacks of the conventional magnetic card reader / writer and adds a function of accurately determining the recorded data, so that accurate data determination can be performed without being affected by noise during reading. The purpose is to provide a possible magnetic card reader / writer.

[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 specifying circuits for specifying a data judgment position for each bit of the recording data, and these judgment position specifying circuits A plurality of data judging circuits for judging the recording data at the data judging position designated by the judging position designating circuit, and a confirmation judging circuit for judging the data judging signals from these data judging circuits by majority decision. A magnetic card reader / writer is provided.

Further, according to the present invention, the plurality of judgment position specifying circuits include a first judgment position specifying circuit and a first judgment position specifying circuit.
The second determination position designating circuit that designates the data determination position at the front position with respect to the data determination position of the determination position designating circuit and the rear position with respect to the data determination position of the first determination position designating circuit. A plurality of data judgment circuits, the third judgment position specifying circuit specifying a data judgment position, and the plurality of data judgment circuits include first to third data judgment specified by the first to third judgment position specifying circuits. In position,
There is provided a magnetic card reader / writer characterized by having first to third data judging circuits for respectively judging data.

Further, according to the present invention, the first determination position designating circuit designates a data determination position at a position of about 75% of a 1-bit length for each bit of the recording data, and the second determination position is specified. The designating circuit designates the data determination position at a front position by a bit length of about 10% with respect to the data determination position of the first determination position designating circuit, and the third determination position designating circuit designates the data determination position. The magnetic card reader / writer is configured so as to specify the data determination position at a backward position by a bit length of about 10% with respect to the data determination position of the determination position designation circuit 1 described above. Provided.

[0009]

According to the magnetic card reader / writer of the present invention, in the demodulation circuit, a plurality of judgment position designating circuits for generating first to third judgment position signals for designating the data judgment position of the recording data, and these are provided. A plurality of data judgment circuits for judging recording data at the data judgment positions designated by the first to third judgment position signals;
From the first to third data determination signals from the third to third data determination circuits, confirmation determination is performed by majority so that the data determination signal having the larger number of data determination signals showing the same determination result is used as the determination data. Since it is provided with a confirmation determination circuit for performing the determination, it becomes possible to accurately determine the recording data regardless of the presence of noise.

That is, when reading the recording data, the one having the larger number of the data judging signals showing the same judgment result among the plural data judging signals obtained by judging the recording data at the plural data judging positions. Since the data determination signal of is used as the determination data, it is possible to accurately determine the recording data that is not affected by noise.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a magnetic card reader / writer according to the present invention will be described with reference to FIGS.

FIG. 1 is a block diagram showing the configuration of a decision position designating section and a data decision section in the magnetic card reader / writer demodulation circuit of the present invention. Reference clock generation circuit 1
Generates a reference clock 2 faster than the human power data. The counter circuit 3 counts one bit of the recording data 19 with the reference clock 2 and generates a counter signal 4. Then, the counter signal 4 is supplied to the first to third determination position specifying circuits 5, 7, and 9.

The first judgment position designating circuit 5 generates a first judgment position signal 6 for designating a position of about 75% of a 1-bit length for each 1 bit of the recording data 19. The second determination position designating circuit 7 outputs 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. Occur. The third determination position designating circuit 9 is the first determination position designating circuit 5 of the first determination position designating circuit 5.
With respect to the judgment position signal 6 of No. 3, the third judgment position signal 10 for designating the rear position by a bit length of about 10% is generated. These first to third determination position signals 6, 8, 10
Are the first to third data determination circuits 11 and 1 respectively.
3 and 15 are supplied.

The first data judgment circuit 11 judges the recording data 19 according to the first judgment position signal 6 and generates the first data judgment signal 12 which is the result of the judgment. The second data judgment circuit 13 judges the recording data 19 based on the second judgment position signal 8 and generates a second data judgment signal 14 which is the result of the judgment. Third data determination circuit 15
Determines the recording data 19 by the third determination position signal 10 and generates a third data determination signal 16 as a result of the determination. These first to third data determination signals 12,
14 and 16 are supplied to the confirmation determination circuit 17.

The confirmation and judgment circuit 17 confirms and judges the first to third data judgment signals 12, 14 and 16 by a majority decision, and therefore the first to third data judgment signals 12, 14 and 16 are provided on the output side thereof. The data judgment signal having the larger number of data judgment signals showing the same judgment result out of 16 is taken out as judgment data 18.

FIG. 2 shows the judgment position designating circuit shown in FIG.
FIG. 6 is a waveform diagram for explaining a recording data determination operation by a data determination circuit and a confirmation determination circuit. FIG. 2A is a waveform diagram of the recording data 19, where (1) and (2) show data “0” and “1”, respectively, and (3) shows data “0”.
Indicates that it is affected by noise. Figure 2
(B), (C), and (D) show the first to third determination position signals 6, 8 and 10 which are the output signals of the first to third determination position designating circuits 5, 7 and 9, respectively. , FIG. 2 (E),
(F) and (G) show the first to third data determination signals 12, 14 and 16 which are the output signals of the first to third data determination circuits 11, 13 and 15, respectively.

The first determination position signal 6 is the recording data 19
It occurs at a position of about 75% of the 1-bit length for each 1-bit. The second determination position signal 8 is generated at a position ahead of the first determination position signal 6 by about 10% bit length.
The third determination position signal 10 is generated at a rear position with respect to the first determination position signal 6 by a bit length of about 10%.
FIG. 2H shows the determination data 18 which is the output signal of the confirmation determination circuit 17.

First to third determination position signals 6, 8, 10
When the recording data 19 is affected by noise in the recording data determination operation by the recording data determination operation according to (1), for example, as shown in FIG.
When 9 is affected by noise, different determination results are obtained from the data determination signal 12 based on the first determination position signal 6 and the data determination signals 14 and 16 based on the second and third determination position signals 8 and 10. Although shown, the second data determination signal 14 based on the second determination position signal 8 and the third data determination signal 16 based on the third determination position signal 10 show the same determination result.

That is, in the case of FIG. 2C, the data determination result by the first determination position signal 6 is the data "1" because the high level portion of the data is detected, but the second and third data determination results are obtained. It can be seen that the data determination result based on the determination position signals 8 and 10 is data "0" because the low level portion is detected.

In this case, the confirmation / judgment circuit 17 performs the confirmation / judgment of these first to third data judgment signals 12, 14, 16 by a majority decision, and the second or third data judgment signal 14 showing the same judgment result. Since or 16 is output as the determination data 18, the data determination result of FIG. 2C is data “0”.

That is, the first to third determination position signals 6,
First to third three data determination signals 1 by 8 and 10
Even if one of 2, 14, 16 shows a different judgment result from the other two data judgment signals, if the other two data judgment signals show the same judgment result, the same judgment result is shown. Since the data determination signal is used as the determination data at that time, accurate data determination that is not affected by noise can be performed.

In the above embodiment, the data judgment position is set at three positions, but the data judgment position is not necessarily limited to three positions, and by selecting an appropriate value in consideration of the usage environment etc., the reliability of reading out the recorded data can be improved. It is possible to improve the property.

Further, in the above embodiment, the positions of the second and third judgment position signals 8 and 10 are arranged at positions displaced by about 10% from the position of the first judgment position signal 6. It is not necessarily limited to 10%, but by selecting an appropriate value in consideration of the read margin of the recorded data when the magnetic card is running at a constant speed, and the read margin of the recorded data when the speed of the magnetic card is manually run. The reliability of reading recorded data can be improved.

[0024]

As described above, according to the present invention,
A plurality of judgment position designating circuits that specify a plurality of data judgment positions for each bit of the recording data recorded on the magnetic card; and a plurality of data judgment circuits that judge the recording data at the plurality of data judgment positions. A magnetic card reader / writer with high accuracy that is not affected by the usage environment is provided by including a comparison / determination circuit that performs a comparison determination based on a majority decision of a plurality of data determination signals obtained by determining recorded data at a plurality of data determination positions. can get.

That is, in the magnetic card reader / writer of the present invention, since the recorded data can be confirmed and read from a plurality of data determination results obtained by determining the recorded data at a plurality of data determination positions, Some magnetic card reader / writers can also read magnetic cards that could not be read due to noise.

[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 magnetic card reader / writer demodulation circuit of 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 shown in FIG. 1 of the present invention.

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

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

[Explanation of symbols]

 1 Reference Clock Generation Circuit 2 Reference Clock 3 Counter Circuit 4 Counter Signal 5 First Judgment Position Designating Circuit 6 First Judgment Position Signal 7 Second Judgment Position Designation Circuit 8 Second Judgment Position Signal 9 Third Judgment Position Designating circuit 10 Third determination position signal 11 First data determination circuit 12 First data determination signal 13 Second data determination circuit 14 Second data determination signal 15 Third data determination circuit 16 Third data determination Signal 17 Confirmation determination circuit 18 Determination data 19 Recording data 31 Reference clock generation circuit 32 Reference clock 33 Counter circuit 34 Counter signal 35 Determination position designation circuit 36 Determination position signal 37 Recording data 38 Data determination circuit 39 Determination data

Claims (3)

[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 designating positions of the recording data are designated for each bit of the recording data. Decision position designating circuits, a plurality of data decision circuits for determining the recording data at the data decision positions designated by these decision position designating circuits, and the data decision signals from these data decision circuits are confirmed by majority decision. A magnetic card reader / writer, comprising: 2. The plurality of determination position designating circuits include a first
Of the first determination position designating circuit, and 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. A third determination position designating circuit that designates a data determination position at a rear position with respect to the data determination position, and the plurality of data determination circuits are designated by the first to third determination position designating circuits. The magnetic card reader / writer characterized in that the magnetic card reader / writer has first to third data determination circuits for respectively performing data determination at the selected first to third data determination positions. 3. The first determination position designating circuit determines the data determination position by 1 bit length for each bit of the recording data, which is about 7 bits.
5% position is specified, and the second judgment position specifying circuit is
The data determination position is designated by a front position by a bit length of about 10% with respect to the data determination position of the first determination position circuit, and the third determination position designating circuit designates the first determination position designating circuit. The magnetic card reader / writer is configured so that the data determination position is designated at a rear position by a bit length of about 10% with respect to the data determination position of the circuit.