JPH08106604A - Magnetic data reader - Google Patents

Abstract

(57) [Summary] [Purpose] The output of the magnetic head is divided into two systems and read.
Increase the reliability of data reading. A first data reading means for reading data recorded on a magnetic recording medium (magnetic card) on the basis of peak detection of a signal extracted via a magnetic head, and a signal extracted via the magnetic head are predetermined. Second data reading means for reading based on the threshold value of, and data check for checking the data read respectively by the first reading means and the second reading means using a data check method such as a CRC check method And the data checking means determines that both the data read by the first reading means and the data read by the second reading means are correct, it is determined that one of the data is correct or only one of the data is correct. In this case, the data fetching means fetches the data determined to be correct for arithmetic processing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic data reader for reading data recorded on a magnetic recording medium such as a magnetic card, and more particularly, it is called a frequency modulation (FM) system or an F2F system. Reading device.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing a schematic configuration of a conventional F2F type magnetic data reader, in which a magnetic recording medium (hereinafter referred to as a magnetic card) C is pinched via a transport mechanism (not shown). When the roller R moves while contacting the magnetic head H while being pressed by a predetermined pressure, the magnetic head H is configured to obtain a waveform output of a read voltage corresponding to the data recorded on the magnetic card C. .

An output from the magnetic head H is processed by a peak detection / amplification circuit 1 having an amplification function, a peak detection function and a waveform shaping function, and then input to an F2F demodulation logic circuit 2. The peak detecting / amplifying circuit 1 and the F2F demodulating logic circuit 2 are usually composed of a semiconductor integrated circuit (LSI) and are commercially available.

As shown in FIG. 5, the F2F demodulation circuit 2 is configured to generate an F2F signal synchronized with a clock signal. That is, this F2F signal is
When there is no edge change in 1 bit, that is, when the frequency is 1F, a logical value "0" (hereinafter, the logical value may be omitted), and when there is an edge change in 1 bit That is, when the frequency is 2F, it is set to "1".

The signal (data) converted into the F2F pattern signal by the F2F demodulation circuit 2 has a predetermined number of bits read and discarded in order to remove the unstable data at the beginning of the data reading of the magnetic card C. , The serial interface (I / F) circuit 3 is incorporated into the CPU 4.

For example, when the magnetic data reader is incorporated in an automatic ticket gate, the CPU 4 controls the automatic ticket gate in a centralized manner. Therefore, the data taken in via the serial I / F circuit 3 is used for the arithmetic processing of the ticket gate processing.

[0007]

However, in the above-mentioned conventional magnetic data reading apparatus, the processing until the signal read by the magnetic head is input to the CPU is performed by one hardware processing, so that it is determined by noise or the like. All read signals out of the standard of 1 result in a read error, and there is a drawback that the reliability of the entire system incorporating the magnetic data reader, for example, an automatic ticket gate, is deteriorated.

Therefore, the present invention has been made to solve the above-mentioned drawbacks, and an object of the present invention is to provide a magnetic data reading apparatus capable of reducing reading errors and improving reliability. .

[0009]

In order to achieve the above object, a magnetic data reader according to the present invention is based on peak detection of a signal obtained by extracting data recorded on a magnetic card through a magnetic head. First data reading means for reading, second data reading means for reading a signal extracted via the magnetic head based on a predetermined threshold value, and data read by the first reading means and the second reading means, respectively. When the data check means for performing the data check using the data check method such as the CRC check method and the data check means determines that the data read by the first reading means and the data read by the second reading means are both correct, When it is judged that either one of them or only one of them is correct, the data judged as correct is processed. It is characterized by having a Tokomu data acquisition means.

[0010]

In the above structure, the data check means is the first
When it is determined that the data read by the reading means and the data read by the second reading means are both correct, one of the data is determined, and when it is determined that only one of the data is determined, the data determined to be correct. Is taken in for arithmetic processing.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an apparatus according to an embodiment. Note that the same reference numerals are used for the same components as the conventional ones, and the description of these components will be duplicated, so only the new portions will be assigned different reference numerals for the description.

In the figure, reference numeral 5 is a comparator circuit, which outputs the output waveform of the magnetic head H shown in FIG. 2 (the waveform in FIG. 1B) to the + and-sides to a predetermined threshold value ± th. It is configured to be used for slicing to obtain respective outputs. Reference numeral 6 is the same F2F demodulation logic circuit as the F2F demodulation logic circuit 2, and reference numeral 7 is the same serial I / F circuit as the serial I / F circuit 3.

The peak detecting / amplifying circuit 1, the F2F demodulating logic circuit 2 and the serial I / F circuit 3 in the apparatus of the present embodiment detect the peaks p, p ... Of the waveform in FIG. 2 and read the data of the magnetic card C. It constitutes the first data reading means of the invention.

The comparator circuit 5, the F2F demodulation logic circuit 6 and the serial I / F in the apparatus of this embodiment are also provided.
The circuit 3 reads the data of the magnetic card C obtained by slicing the waveform of FIG. 2 at a predetermined threshold value ± th.
It constitutes data reading means.

Next, the data reading control operation of the magnetic card C will be described with reference to the flowchart of FIG.

Now, when the magnetic card C is inserted into a magnetic card processor such as an automatic ticket gate and slides on the magnetic head H,
A signal having an output waveform corresponding to the data recorded on the magnetic card C as shown in FIG. 2 is obtained from the magnetic head H (Yes at step 100. Hereinafter, step is referred to as S).

The output of the magnetic head H is divided into two, one of which is taken in by the CPU 4 through the peak detection amplification circuit 1, the F2F logic circuit 2 and the serial I / F circuit 3, and the other of which is the comparator 5. , F2F demodulation logic circuit 6 and serial I / F circuit 7 are taken in by the CPU 4 (S102).

That is, two kinds of read data having different detection methods are fetched into the CPU 4, and the RAM of the CPU 4 is loaded.
(Not shown). The stored read data should match if read normally. Then, in order to check whether or not the data is normally read, it is determined by the CRC check method (S104).
It should be noted that this determination method may be based on another check method such as parity check instead of CRC check.

First, a CRC check is performed on the data obtained on the peak detection amplifier circuit 1 side (S106). Then, if the result of the CRC check is OK (normal), the data is used for predetermined arithmetic processing such as automatic ticket gate arithmetic (Yes at S106, S108).

When the above-mentioned CRC check is NO (abnormal) (No in S106), the data is discarded and the data CR on the side of the comparator circuit 5 is CR.
A C check is performed (No at S106, S110). If the result of this CRC check is OK, the data is used for predetermined arithmetic processing (S112). Also, this C
When the determination of RC check is also NO (No in S110),
Since both read data are abnormal, a read error occurs and abnormal processing is performed. Specifically, when the magnetic card C is inserted in the automatic ticket gate, the door is closed to prevent passage through the ticket gate passage, and the inserted magnetic card C is returned.

As described above, the apparatus of this embodiment can read the output of the magnetic head in two systems, and if the read data of either one of them is correct, the data can be adopted for the arithmetic processing. Therefore, the reliability of reading can be improved.

In the above-mentioned embodiment, the CRC check of the peak read data is performed first, but it may be performed after the CRC check of the threshold data. Alternatively, the CRC check may be performed on both of them in parallel, and if both are OK, either one of the data may be adopted.

[0023]

The magnetic data reading apparatus according to the present invention includes the first data reading means for reading the data recorded on the magnetic card based on the peak detection of the signal extracted through the magnetic head, and the magnetic head. Second data reading means for reading the signal extracted through the first threshold value based on a predetermined threshold value;
Data checking means for checking the data respectively read by the reading means and the second reading means using a data checking method such as a CRC checking method, and the data checking means is the first reading means and the second reading means. If both of the read data are judged to be correct, the data of one of them is taken in, and if the data of only one of them is judged to be correct, the data judged to be correct is taken in for arithmetic processing. Since it is composed of the data fetching means, the output of the magnetic head is read by two systems, and if the read data of either one is correct, the data can be adopted and used for the arithmetic processing. The reliability of can be increased.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is an output waveform of a magnetic head.

FIG. 3 is a flowchart illustrating a control operation.

FIG. 4 is a schematic configuration diagram of a conventional device.

FIG. 5 is an explanatory diagram of an F2F signal.

[Explanation of symbols]

 1 Peak detection amplification circuit 2,6 F2F demodulation logic circuit 3,7 Serial I / F circuit 4 CPU 5 Comparator circuit

Claims (1)

[Claims] 1. A first data reading means for reading data recorded on a magnetic recording medium based on peak detection of a signal extracted through a magnetic head, and a predetermined signal for extracting the signal extracted through the magnetic head. Second data reading means for reading based on a threshold value, and data checking means for checking the data respectively read by the first reading means and the second reading means using a data checking method such as a CRC checking method When the data checking means determines that both the data read by the first reading means and the data read by the second reading means are both correct, it is determined that one of the data is correct, or only one of the data is correct. In this case, a magnetic data reading device comprising: a data fetching unit that fetches the data determined to be correct for arithmetic processing.