JPH04132018A - Magnetic card - Google Patents

Abstract

PURPOSE:To prohibit the easy reading of data and to improve security by forming a clock track 4 of a magnetic material having a low residual magnetic flux density, thereby varying the magnetization systems of a data track and the clock track. CONSTITUTION:This magnetic card 1 is arrayed with the band-shaped data track 3 and the clock track 4 on the front surface of a card-shaped base material 2. The data track 3 is formed of the magnetic material having a high residual magnetic flux density and the clock track 4 is formed of the magnetic material having the low residual magnetic flux density. The security of the magnetic card 1 is improved in this way and the generation of data errors is effectively prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic card that improves the reliability of data reading and improves security.

[Prior Art] In a conventional magnetic card, a data track for writing data and a clock track for writing a clock signal are formed of the same magnetic material (hard magnetic material with high residual magnetic flux density), and data is written on the data track. When writing, the clock signal was written to the clock track using the same magnetization method.

[Problems to be Solved by the Invention] However, in conventional magnetic cards, data tracks and clock tracks are formed of the same magnetic material and written using the same magnetization method, so data cannot be easily read. Unfortunately, there was a security problem.

In addition, if there are speed fluctuations in the transport system of the reader/writer that reads and writes magnetic cards, the speed fluctuations will be affected during writing and reading, and the clock signal and data will not be synchronized, resulting in data errors. There was such a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic card that can solve the above-mentioned conventional problems, improve the security of the magnetic card, and effectively prevent the occurrence of data errors.

[Means for Solving the Problems] The present invention that achieves the above object includes a data track for writing magnetic data on the surface of a card-like base material, and a system for synchronizing the reading and writing of magnetic data on the data track. A magnetic card provided with a clock track for writing a clock signal, characterized in that the clock track is formed of a magnetic material with a low residual magnetic flux density.

The second aspect of the invention is characterized in that the clock track is formed of a soft magnetic material.

The third aspect of the invention is characterized in that a clock signal is recorded on the clock track in advance.

The fourth aspect of the invention is characterized in that the clock track is formed by arranging blocks made of a magnetic material with low residual magnetic flux density in a line at equal intervals, and the data track is formed between the blocks.

[Examples] Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows a plan view of a magnetic card according to an embodiment of the present invention.

This magnetic card 1 has a strip-shaped data track 3 and a clock track 4 arranged side by side on the surface of a card-shaped base material 2.

The data track 3 is formed of a magnetic material (for example, a hard magnetic material) having a -H curve (hysteresis characteristic) and a high coercive force, that is, a high residual magnetic flux density, as shown in FIG. 3(A).

The clock track 4 is formed of a magnetic material with a low coercive force, that is, a low residual magnetic flux density, and has a B-H curve (hysteresis characteristic) as shown in FIG. 2(B).

Here, as the magnetic material with low residual magnetic flux density, for example, a soft magnetic material is used.

The clock track 4 is constructed by arranging block pieces 5 made of magnetic material in a row at equal intervals as shown in FIG. It is assumed that a clock signal is written in advance when manufacturing a magnetic card. This clock track 4
As described above, since it is constructed using a magnetic material with a low coercive force, that is, a low residual magnetic flux density, it cannot be detected by the conventional detection method of reading the data track 3.

Next, we will explain the use example of the magnetic card configured for the above purpose in the fourth example.
This will be explained with reference to the drawings and FIG.

FIG. 4 shows the head configuration of a reader for reading the magnetic card 1 in correspondence with the magnetic card 1. The reader has a reading head 10 for reading the data track 3 and a reading head 11 for reading the clock track 4. , drivers 12 and 13 of the reading head 10.11, a data decoder 14 for decoding read data, and a reading head 11.
A bias application circuit 15 is provided to apply a bias magnetic field to.

Further, it is assumed that a lock signal as shown in FIG. 5 is written in advance in the clock track 4 of the magnetic card 1, and data as shown in FIG. 4 is written in the data track 3.

Clock track 4 cannot be read with a normal head because of its low residual magnetic flux as described above.
Therefore, the bias application circuit 15
It becomes possible to read by applying a bias magnetic field to 1.

Further, the data track 3 is read by the read head IO in synchronization with the read clock signal. and,
The pulse signal read from the data track 3 is decoded by the data decoding circuit 14 to obtain binary data as shown in FIG. In FIG. 5, when reading the second and fourth block pieces 5, the position of the clock signal tends to shift due to speed fluctuations in the conveyance system, but the position where data is written is physically The data is read without any problem because it matches the position of .

In the above embodiment, the data track 3 and the clock track 4 are provided separately, but the data track 3 is formed between the block pieces 5 of the clock track 4, so that the data track 3 and the clock track 4 are located at the same position. They may be overlapped; in this way, only one track is required, which is efficient.

[Effects of the Invention] As explained above, according to the magnetic card of the present invention, since the clock track is formed of a magnetic material with a low residual magnetic flux density, the magnetization methods of the data track and the clock track are different, so that data can be easily transferred. cannot be read, greatly improving security.

In addition, in the invention of item 3, by recording a clock signal on the clock track in advance, even if there is a speed fluctuation in the conveyance system of the league writer that reads and writes magnetic cards, the speed of the clock track only changes when reading. , the occurrence of data errors can be reduced.

In the invention set forth in item 4, the clock track is formed by arranging blocks made of a magnetic material with low residual magnetic flux density at equal intervals in a row, and the data track is formed between the blocks, so that only one track is required. Efficient.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a magnetic card according to an embodiment of the present invention, Fig. 2 is a partially enlarged view of a clock track of the magnetic card shown in Fig. 1, and Figs. 3 (A) and (B) are data data. A diagram showing the B-H curves of the hard magnetic material and soft magnetic material constituting the track and the clock track. FIG. 4 is a circuit diagram showing an example of the read head for reading the magnetic card of this embodiment. FIG. 5 is the clock track. FIG. 3 is a diagram showing an example of a lock signal and data on a data track. l: Magnetic card 2: Base material 3: Data track 4: Clock track 5 Ni block piece 10.11: Reading head 12.13: Driver 14: Data decoding circuit 15: Bias application circuit Applicant: SiniSkei Nippon Card Center Co., Ltd. Co., Ltd.

Claims (4)

[Claims] (1) In a magnetic card provided with a data track for writing magnetic data on the surface of a card-like base material, and a clock track for writing a clock signal for synchronizing the reading and writing of magnetic data on the data track, the above-mentioned clock A magnetic card characterized in that a track is formed of a magnetic material with low residual magnetic flux density. (2) The magnetic card according to claim 1, wherein the clock track is formed of a soft magnetic material. (3) The magnetic card according to claim 1 or 2, wherein a clock signal is recorded in advance on the clock track. (4) The magnetic field according to claim 1, wherein the clock track is formed by arranging blocks made of a magnetic material with a low residual magnetic flux density in a line at equal intervals, and the data track is formed between the blocks. card.