JP4945786B2 - Magnetic information reading method - Google Patents

Description

  The present invention relates to a magnetic information reading method for reading magnetic information recorded on a magnetic medium using a magnetic head, and more particularly to a method for improving the reliability.

  In general, as a magnetic recording system used in a magnetic recording / reproducing apparatus such as a card reader, an FM modulation system in which binary magnetic information is recorded on a magnetic medium by a combination of two types of frequencies F and 2F is known. Yes. When reading the magnetic information recorded by the FM modulation method, the magnetic head is slid relative to the magnetic stripe on the magnetic medium to reproduce the magnetic information as an analog reproduction signal, and based on the analog reproduction signal. Then, the binary data is demodulated (see, for example, Patent Document 1).

The magnetic card reader disclosed in Patent Document 1 compares a magnetic head and a reproduction signal from the magnetic head with two slice levels (± V ₁ , ± V ₂ (<± V ₁ )). It has a plurality of sense circuits for converting into (binary) signals, and a switching circuit for switching between two slice levels. The switching circuit switches the slice level used in the sense circuit in accordance with the level change of the reproduction signal.

For example, when a reading error occurs using a slice level ± V ₁ in a card reader for motor conveyance, the slice level is switched to ± V ₂ by the switching circuit, and the magnetic card is again conveyed in the conveyance path. is (move back and forth in the magnetic card in the transport path), this time has been attempted to read the magnetic information by using the slice level ± V _2. Further, in the case of a manual card reader instead of a motor-conveyed card reader, after switching the slice level, it is necessary to hold the magnetic card in the hand and travel in the conveyance path.

As described above, in the conventional magnetic card reader, even if a plurality of slice levels (± V ₁ , ± V ₂ (<± V ₁ )) are set, they are converted in comparison with the slice level ± V _1. Either a digital signal enters the control unit, or when a reading error occurs, a digital signal converted in comparison with the slice level ± V ₂ enters the control unit. .

JP-A-2-244407 (FIG. 3)

However, in the manual of the card reader, when the read error by using the slice level ± V ₁ occurs, with the hand again the magnetic card, when it comes must be swiped in a conveying path, the operator Complicated work will be forced.

  In other words, even if a reading error occurs, a motor-carrying card reader can automatically reverse the magnetic card in the card reader as described above and re-capture a stable magnetic reproduction signal. However, in the case of a manual card reader (a swipe type card reader is considered here), since the magnetic card does not automatically reverse, a swipe operation is always required. In addition, when a person who handles a manual card reader is a beginner, it is difficult to obtain a stable magnetic reproduction signal by one swipe operation, and it is necessary to swipe twice or three times. There is.

  On the other hand, even if a person who handles a manual card reader is an expert, if the magnetic card has been used for many years, the magnetism in the magnetic stripe has deteriorated due to the influence of the outside world, and is stable. It may be difficult to capture the magnetic reproduction signal. Even if the magnetic card has not been used for many years, there is no guarantee that magnetism is correctly recorded in the magnetic stripe, and there is a possibility that a reading error will occur.

  The present invention has been made in view of the above points, and an object of the present invention is to accurately read magnetic information recorded on a magnetic medium with a small number of medium operations (for example, a card swipe operation), and thus the apparatus. An object of the present invention is to provide a magnetic information reading method capable of improving the reliability.

  In order to solve the above problems, the present invention provides the following.

(1) A magnetic head for reproducing magnetic information recorded on a magnetic medium and generating a reproduction signal, an amplification circuit for amplifying the reproduction signal and generating an amplification signal, and the amplification signal at a predetermined level At least two detectors that activate the point and output an original signal that is a source for decoding, and at least two detectors that are provided corresponding to each of the detectors and determine whether magnetic information is read correctly or not A magnetic information reading method in a manual magnetic medium processing apparatus having a determination unit, wherein the reproduction signal generated by reading by the magnetic head is amplified by the amplification circuit and amplified to be generated Are input to each of the detection units, and each of the detection units generates and outputs the original signal from the amplified signal, and the original signal output from each of the detection units. A step of inputting to each of the corresponding determination units ; a step of decoding the input original signal in each of the determination units; and a magnetic field based on the original signal decoded in each of the determination units. And a step of independently determining whether the information is read correctly or not.

  According to the present invention, in a manual magnetic medium processing apparatus having a magnetic head, an amplifier circuit, at least two detection units, and at least two determination units provided corresponding to each of the detection units. In the magnetic information reading method, in each determination unit, a step of decoding an original signal which is an output of a corresponding detection unit, and a step of independently determining whether or not the magnetic information is read based on the decoded original signal Therefore, the reliability of the apparatus can be improved.

That is, for example, in the conventional magnetic card reading apparatus in which the slice levels ± V ₁ and ± V ₂ are set, when reading at the slice level ± V ₁ fails, the reading at the slice level ± V ₂ is executed. The operator has been requested to operate the medium again (for example, swipe operation). However, according to the present invention, the original signals that are the outputs of at least two detection units are input to at least two determination units corresponding to them, and then decoded and read independently by each determination unit. Since the correct / incorrect determination is made, for example, even when reading at the slice level ± V ₁ fails, the operator again performs medium operation (for example, swipe operation) to execute reading at the slice level ± V _2. Does not have to be requested.

  Therefore, the magnetic information recorded on the magnetic medium can be read with high accuracy by a small number of medium operations (for example, a swipe operation), and the reliability of the apparatus can be improved. In addition, when considering a DIP type (plug-in type) magnetic medium processing apparatus as a manual magnetic medium processing apparatus, it is difficult to operate a card at a constant speed compared to a swipe type magnetic medium processing apparatus. Therefore, it is more difficult to slide in and out at a constant speed than in the vertical and horizontal directions, so that magnetic information can be read accurately and effectively by applying the present invention. .

(2) The manual magnetic medium processing apparatus includes a selection unit that selects one of the determination units, and after each of the determination units independently determines whether or not magnetic information is read, the magnetic information A method for reading magnetic information, comprising the step of the selection unit selecting one of the determination units that succeeded in reading.

  According to the present invention, the above-described manual magnetic medium processing apparatus is provided with a selection unit that selects any one of the determination units. In the above-described magnetic information reading method, each determination unit reads magnetic information. Since the step of selecting one of the determination units that have succeeded in reading the magnetic information after the determination of whether the magnetic information is correct or not is included, the magnetic information can be read using a suitable determination result with a small number of medium operations. Reading can be performed with high accuracy, and as a result, the reliability of the apparatus can be increased. In addition, the selection aspect by a selection part does not ask | require. For example, when reading is successfully performed by a plurality of determination units, the most accurate one can be used (for example, if reading is performed at a slice level as large as possible, adverse effects due to minute noise are minimized. be able to).

(3) the at least two detector, Part 1 is the amplified signal is composed of high-slice circuit to enable the point to the first level, than the other one is the amplified signal is the first level A method for reading magnetic information, characterized by comprising a low slice circuit that validates a low second level point.

  According to the present invention, the detection unit described above enables a high slice circuit that enables a point where the amplified signal becomes the first level, and a point where the amplified signal becomes the second level lower than the first level. The low-slicing circuit is provided, so that the detection accuracy can be set easily (to change the detection accuracy, the slice level can be changed), and the magnetic information can be read with high accuracy, thereby improving the reliability of the apparatus. Can be increased.

(4) said at least two detector, method for reading magnetic information, characterized in that one of which is constituted by a peak detector for detecting a peak value of the amplified signal.

  According to the present invention, since the detection unit described above is provided with a peak detection unit that detects the peak value of the amplified signal, for example, by combining with the above-described high slice circuit or low slice circuit (increasing variations), It becomes possible to read magnetic information with higher accuracy.

  According to the magnetic information reading method of the present invention, in a manual magnetic medium processing apparatus having at least two detection units and at least two determination units, the outputs of these detection units are sent to corresponding determination units. Since it is input and effectively used, it is possible to prevent the operator from forcing media operation again due to the change in detection accuracy of the detection unit (for example, changing the slice level). As a result, the reading accuracy of magnetic information can be improved and the reliability of the apparatus can be improved.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a card reader 1 in which a magnetic information reading method according to an embodiment of the present invention is used. In particular, FIG. 1A is a schematic plan view when the card reader 1 is viewed from above, and FIG. 1B is a schematic side view when the card reader 1 is viewed from the side. In FIG. 1, a DIP card reader is used. However, for example, a swipe card reader may be used.

  In FIG. 1, the card reader 1 has a magnetic head 11, and when the magnetic card 20 is inserted into the transport path, magnetic information is read by the magnetic head 11. More specifically, the card reader 1 employs an FM modulation method in which binary magnetic information is recorded on the magnetic card 20 by a combination of two types of frequencies F and 2F, and is recorded by the FM modulation method. When reading the magnetic information, the magnetic head 11 is made to contact and slide relative to the magnetic stripe 20a on the magnetic card 20, and the magnetic information is reproduced as an analog reproduction signal. Demodulate binary data.

  The magnetic head 11 includes at least a pair of magnetic cores arranged to face each other with a magnetic gap (gap spacer) interposed therebetween, and a reproducing coil is wound around one of the magnetic cores. Moves relative to each other with a predetermined pad pressure. Thereby, the magnetic information stored in the magnetic card 20 can be read. As described above, the magnetic head 11 has a function of reproducing the magnetic information recorded on the magnetic card 20 and generating a reproduction signal. Further, the magnetic head 11 is generally arranged such that the gap forming surface protrudes into the card transport path.

  FIG. 2 is a block diagram showing an electrical configuration of the card reader 1 shown in FIG.

  In FIG. 2, a high slice circuit 13 and a low slice circuit 14 are connected to the magnetic head 11 via an amplifier circuit 12. The amplifier circuit 12 includes an operational amplifier, a capacitor, and the like, and is a circuit that amplifies the reproduction signal sent from the magnetic head 11 and generates an amplified signal. Then, the high slice circuit 13 and the low slice circuit 14 enable a point where the amplified signal becomes a predetermined slice level (for example, 120 mV, 30 mV), and output an original signal that is a source for decoding. That is, for example, an original signal is output that becomes Hi in an area exceeding a predetermined slice level and becomes Lo in an area within a predetermined slice level.

  The high slice circuit 13 and the low slice circuit 14 are respectively connected to a determination unit 16 and a determination unit 17 in the signal processing unit 15 (for example, a CPU). The determination unit 16 and the determination unit 17 decode the original signals sent from the high slice circuit 13 and the low slice circuit 14, respectively, and independently determine whether the magnetic information is read or not based on the decoded original signals. judge.

  In FIG. 2, the outputs of the high slice circuit 13 and the low slice circuit 14 are input to the signal processing means 15 through different (two) electrical wirings, but the present invention is not limited to this, and these outputs are not limited thereto. May be input by one electric wiring as long as the relationship satisfies the independent relationship. Further, in the signal processing means 15, the determination unit 16 and the determination unit 17 are provided as separate block diagrams for convenience of explanation. 17 may be created. Further, in the signal processing means 15, a memory such as a RAM or a ROM is arranged, although not particularly shown.

FIG. 3 is a waveform diagram showing signal waveforms in the respective parts (a) to (c) of the block diagram shown in FIG. Note that the signal waveforms (a) to (c) in FIG. 3 indicate the signal waveforms at the positions (a) to (c) in FIG. 2.

  In FIG. 3, the reproduction signal obtained by sliding the magnetic head 11 relative to the magnetic stripe 20a is amplified by the amplifier circuit 12, and as shown in FIG. And an amplified signal having a signal waveform oscillating in the negative direction.

  Then, the amplified signal shown in (a) is input to the high slice circuit 13 and the low slice circuit 14, and the point at which it reaches a predetermined level is validated. Specifically, the waveform falls as the output of the high slice circuit 13 at the slice level HS below (−) the reference potential, and becomes the slice level HS above (+) the reference potential. At this point, a signal whose waveform rises, that is, an original signal shown in (b) is obtained. On the other hand, as the output of the low slice circuit 14, the waveform falls and becomes the slice level LS above (+) the reference potential at the point where the slice level LS is below (−) the reference potential. A signal whose waveform rises, that is, an original signal shown in (c) is obtained.

  Here, the amplitude of the amplified signal shown in (a) is small during the time interval X. Therefore, when focusing on the original signal shown in (b), the amplified signal shown in (a) is not faithfully reflected even though the polarity is inverted during the time interval X (time). There is no on / off during interval X). Therefore, when the original signal shown in (b) is used for reading correctness of magnetic information, a reading error occurs in the determination unit 16 (and thus the signal processing means 15).

  Therefore, the original signal shown in (c) is used instead of the original signal shown in (b) for correct / incorrect reading of the magnetic information. The original signal shown in (c) is repeatedly turned on and off during the time interval X, and the amplified signal shown in (a) faithfully reflects that the polarity is inverted during the time interval X. is doing. Therefore, the magnetic information can be appropriately read by the determination unit 17 based on the original signal shown in (c).

  FIG. 4 is a waveform diagram showing other signal waveforms in the respective parts (a) to (c) of the block diagram shown in FIG. In addition, the signal waveforms of (a) to (c) in FIG. 4 also show signal waveforms at the positions (a) to (c) in FIG. In particular, FIG. 4 differs from FIG. 3 in that a read error occurs when the output of the low slice circuit 14 is used for reading magnetic information, and when the output of the high slice circuit 13 is used for reading magnetic information, the magnetic information is appropriately displayed. An example that can be read is shown.

In the amplified signal shown in FIG. 4, noise N _{1 to} N ₃ occurs in the time interval Y. When the output of the low slice circuit 14 is used, these noises N _{1 to} N ₃ are picked up and repeatedly turned on and off as shown in (c). Accordingly, since the number of times of ON / OFF of the desired original signal is repeated, a reading error occurs in the determination unit 17 (and thus the signal processing unit 15).

  Therefore, the original signal shown in (b) is used instead of the original signal shown in (c) for correct / incorrect reading of magnetic information. The original signal shown in (b) is repeatedly turned on and off during the time interval Y, but the amplified signal shown in (a) faithfully reflects that the polarity is inverted during the time interval Y. is doing. Therefore, the magnetic information can be appropriately read by the determination unit 16 based on the original signal shown in FIG.

  FIG. 5 is a flowchart for explaining the magnetic information reading method according to the embodiment of the present invention.

  In FIG. 5, first, magnetic card reading is performed (step S1). More specifically, when the magnetic card 20 is inserted into the card insertion slot, the magnetic head 11 comes into contact / sliding contact with the stripe 20a on the surface of the magnetic card 20 to obtain a reproduction signal. Thereafter, the reproduction signal is amplified through the amplifier circuit 12, and the amplified signal is input to each of the high slice circuit 13 and the low slice circuit 14.

  Next, the original signals output from the high slice circuit 13 and the low slice circuit 14 are input to the determination unit 16 and the determination unit 17 (step S2), respectively, and then decoded (step S3).

  Here, the determination unit 16 and the determination unit 17 determine whether or not the magnetic information has been successfully read (step S4). More specifically, as described above, the number of times of polarity reversal (others such as parity check may be used) is detected to determine whether reading is correct or not. Then, the determination result of the determination unit 16 is checked, and if it is determined to be correct, the determination unit 16 is selected (step S5), and the magnetic information is read using the original signal input to the determination unit 16 ( Step S6). If it is determined that the determination result of the determination unit 16 is not correct, the determination result of the determination unit 17 is checked next. If it is determined to be correct, the determination unit 17 is selected (step S5), and the determination unit The magnetic information is read using the original signal input to 17 (step S6). If the determination result of the determination unit 16 is not correct, a reading error occurs although not shown.

  The processing in step S5 will be described in detail. Although not shown in FIG. 2, the signal processing unit 15 includes a selection unit that selects one of the determination units. This selection unit may be realized by a program element such as a CPU or a RAM in the signal processing means 15, or may be realized by hardware (logic IC or the like). By this selection unit, the determination unit 16 or the determination unit 17 that has successfully read the magnetic information is selected, and the magnetic information is read. In FIG. 5, “selection of determination unit” (step S <b> 5) is inserted in the flowchart, but this may be omitted in particular.

[Effect of the embodiment]
As described above, since reading at the slice level HS and reading at the slice level LS can be performed by one card operation, data that could not be read by one card operation until now is read. It will be assisted by another determination unit that has been able to. As a result, the magnetic information recorded on the magnetic card 20 can be read with high accuracy, and the reliability of the apparatus can be improved.

[Modification]
In FIG. 2, the number of detection units and the number of determination units are both two, but may be three, for example. For example, as illustrated in FIG. 6, a peak detection unit 18 and a determination unit 19 that detect the peak value of the amplified signal may be added as one of the detection units. By combining the high slice circuit 13 and the low slice circuit 14 with the peak detector 18 and increasing variations, it is possible to read magnetic information with higher accuracy.

  The magnetic information reading method according to the present invention is useful for enhancing the reliability of a card reader in which it is used.

It is a figure which shows schematic structure of the card reader in which the reading method of the magnetic information which concerns on embodiment of this invention is used. It is a block diagram which shows the electric constitution of the card reader shown in FIG. It is a wave form diagram which shows the signal waveform in each part (a)-(c) of the block diagram shown in FIG. It is a wave form diagram which shows the other signal waveform in each part (a)-(c) of the block diagram shown in FIG. It is a flowchart for demonstrating the reading method of the magnetic information which concerns on embodiment of this invention. It is a block diagram which shows the other electric structure of the card reader shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Card reader 11 Magnetic head 12 Amplifier circuit 13 High slice circuit 14 Low slice circuit 15 Signal processing means 16, 17 Judgment part 20 Magnetic card 20a Magnetic stripe

Claims (4)

A magnetic head for reproducing magnetic information recorded on a magnetic medium and generating a reproduction signal;
An amplification circuit for amplifying the reproduction signal and generating an amplified signal;
Enabling at least a point at which the amplified signal reaches a predetermined level, and outputting at least two detection units that are the original signals for decoding;
A method of reading magnetic information in a manual magnetic medium processing apparatus, which is provided corresponding to each of the detection units and has at least two determination units for determining whether magnetic information is read correctly or not,
Amplifying a reproduction signal generated by reading by the magnetic head with the amplification circuit, and inputting the amplified signal generated by amplification to each of the detection units;
In each of the detection units, generating and outputting the original signal from the amplified signal;
Inputting the original signal output from each of the detection units to each of the corresponding determination units;
Decoding each of the input original signals in each of the determination units;
Each of the determination units includes a step of independently determining whether the magnetic information is read correctly or not based on the decoded original signal. The manual magnetic medium processing apparatus includes a selection unit that selects one of the determination units,
The determination unit includes a step in which the selection unit selects one of the determination units that succeeded in reading the magnetic information after each determination unit independently determines whether or not the magnetic information is read correctly. The magnetic information reading method according to claim 1. Wherein at least two of the detector, high slice is composed of a circuit, a second other one is lower than the amplified signal is the first level one thereof to enable that the amplified signal reaches the first level 3. The magnetic information reading method according to claim 1, wherein the magnetic information reading method comprises a low slice circuit that activates a point that becomes a level. Wherein the at least two detector, method of reading the magnetic information according to any of claims 1 to 3, characterized in that one of which is constituted by a peak detector for detecting a peak value of the amplified signal.

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