JP3614530B2 - Magnetic recording medium and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic recording medium having a high security function such as a cash voucher card (prepaid card) and an ID card, and a method for manufacturing the same.
[0002]
[Prior art]
Magnetic cards are often used as cash vouchers in recent years. However, the ease of recording and reproduction, which is a feature of the magnetic card, also means the ease of copying, and it is necessary to take various measures for preventing forgery. Like cash cards, there is a way to avoid misuse with a security system that restricts the user, such as a PIN, but closes the ease of card duplication, but it is used without specifying the user Various kinds of magnetic cards have been devised in order to provide a security function to the card itself. For example, 1) a method of concealing a magnetic signal so that it cannot be easily read from the outside, 2) a method involving a change in structure before and after use, and 3) a method of detecting by providing a card-specific authentication mark. This is a typical example.
Of these, the method of applying and detecting the individual authentication mark of 3) is roughly classified into optical and magnetic methods. As a method for forming and detecting the latter magnetic authentication mark, for example, as described in (1) Japanese Patent Laid-Open No. 1-208725 and (2) Japanese Patent Laid-Open No. 1-208726, a magnetic card unique to the magnetic card by screen printing or the like is used. A method of applying a bar code, (3) a method of fixing the magnetic recording layer by changing the orientation partially as in Japanese Patent Publication No. 3-68543, or (4) a method of previously disclosed in Japanese Patent Laid-Open No. 6-203366. A method in which a magnetic signal is recorded on the formed first magnetic layer, a second magnetic layer is coated thereon, the concentration of the second layer magnetic particles is generated at the interface of the magnetic reversal portion of the first layer, and the drying is fixed. Proposed.
[0003]
[Problems to be solved by the invention]
The problem of the invention that the present inventor intends to provide is that a unique authentication signal that is different for each card is inherent, the unique signal is a high-density, high-output non-rewritable fixed magnetic signal, and It is an object of the present invention to provide a magnetic card that has a variable magnetic recording / reproducing area for use in the above-described applications and cannot be easily forged, and a production system capable of easily mass-producing the magnetic card. When such a magnetic recording medium is completed, a security system for a magnetic card that is extremely difficult to counterfeit can be constructed in combination with the output reproduction method of the unique signal.
[0004]
Looking at the prior art from this point of view, when applying magnetic bar codes by screen printing represented by the above (1) and (2), since the bar code pattern depends on the printing plate, a specific pattern is used. Although it is suitable for a certain amount of printing, it is not possible to give different unique patterns to the cards. In the method (3), at least from the disclosed contents, it is considered that the output is small and the recording density is inevitably low, and it is difficult as a method for giving a unique signal to a large number of cards. It is understood. In the invention of (4), the recording density of the specific signal is higher than that of the conventional method, and it is possible to give a non-rewritable specific signal different for each card, but the existence of the first magnetic layer is essential for some reason. For this reason, there is a disadvantage that the structure of the medium is limited and the manufacturing method is complicated, and the effect is due to the minute amount of magnetization of the first magnetic layer, so that the intrinsic signal formed in the second magnetic layer A satisfactory solution has not yet been found, such as the expected output value is generally small.
[0005]
[Means for Solving the Problems]
The present invention is a rectangular parallelepiped type in which the tip is appropriately shaped from the top of the coating surface at an arbitrary position in the coating width direction when the magnetic coating is not dried in the step of coating the magnetic coating on the substrate. The magnetic particles in the magnetic paint are caused by the effect of the attraction / release of the magnetic poles that are generated intermittently by causing a predetermined signal current to flow in the coil and causing a predetermined signal current to flow in the coil. Is partially unevenly distributed, and a magnetic particle density pattern is formed in the coating film. By aligning the magnetic particles in the coating direction and then drying and fixing the coating film in a drying oven, the fine magnetic pattern of the magnetic particles is formed, and the fixed magnetic signal pattern area that is not rewritable is not fixed. To provide a method of manufacturing a magnetic recording medium having combination of the gas-recording area in the same magnetic layer.
The present invention also provides an apparatus for manufacturing a magnetic recording medium comprising means for carrying out each step of the above method.
The present invention also provides a magnetic recording medium having a non-rewritable fixed magnetic signal pattern region and a non-fixed magnetic recording region manufactured by the above method in the same magnetic layer.
According to the method of the present invention, since the magnetization easy axis of the magnetic particles is oriented in a direction advantageous for output reproduction in the fixed magnetic signal pattern region, a sufficiently large identification output can be obtained as compared with the conventional case.
When this magnetic recording medium was cut out in a card shape and the output of the sparse / dense pattern portion was measured with a predetermined reproducing head, a desired and clear high-output signal could be obtained. In other words, the density pattern of magnetic particles similar to a magnetic bar code is a fixed signal that cannot be rewritten and is high in density, and if the signal current applied to the electromagnet is devised, each card has a high density. It can be formed as a different unique authentication signal.
[0006]
[Action]
Since the magnetic recording medium according to the present invention has a card-specific and high-density non-rewritable fixed magnetic signal, if you attempt to duplicate it, the same manufacturing process and equipment are indispensable. If you do not have it, you cannot forge it. In addition, if the concealment method of the unique signal is devised, the sparse / dense state cannot be discriminated from the outside, so it is not easily seen, and if the used card or the purchased card is examined in detail, the unique signal of the card can be known. Even if it can be duplicated, there is no meaning in the limited use of a single sheet and there is no reason for it to be economically fit. The present invention for fabricating a card, for example, JISII shape, set the recording area length of the fixed signal to 5 cm, if tentatively form fixed signal of 1mm length per 1bit, is 50 bits across, ^{2 50} a simple calculation on It is possible to generate as many as several unique signals. Furthermore, if a plurality of fixed signal recording track areas are provided and used together, almost infinite inherent signals can be handled.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Next, examples will be described in detail with reference to the accompanying drawings.
FIG. 1 is an outline of the installation of each part of a magnetic paint coating apparatus according to the present invention. DESCRIPTION OF SYMBOLS 1 is the unwinding part of a support base, 2 is a support base, 3 is a magnetic paint coating head apparatus, 4 is a magnetic paint, 5 is a magnetic paint magnetizing apparatus, 6 is a magnetic orientation apparatus, 7 is a drying furnace, 8 is a coated roll It is a winding part. The support base film 2 starts the unwinding unit 1 in order from the left to the right, and is coated with the magnetic paint 4 by the magnetic paint coating head device 3. The magnetic paint magnetizing device 5, the orientation device 6, and the drying furnace 7 are then applied. Are taken up by the winding unit 8 in order.
[0008]
FIG. 2 is a schematic diagram showing a change in the state of magnetic particles in the magnetic paint during the process of forming a coating film of the magnetic recording medium according to the present invention.
Phase 1 is a state in which the magnetic paint 4 is applied to the support base 2 by the coating head unit 3 with a thickness of about 100 μm, for example. In this state, the magnetic particles 4A (indicating easy axes as long lines) are uniformly suspended in a random state in the vehicle 4B. Phase 2 represents a state in which magnetizing action is applied in the vertical direction of the substrate by the magnetizing device 5 and magnetic particles are loosened / dense in the coating film due to the action of attraction / release. Phase 3 represents a state in which the easy axis of magnetization of the magnetic particles oriented in the vertical direction by the magnetic orientation device 6 is oriented in the coating traveling direction. Phase 4 represents a state in which the solvent in the magnetic paint is evaporated by the drying furnace 7 and the thickness is simultaneously reduced to about 15 μm so that the density of the magnetic particles is fixed in the coating film.
[0009]
As the support base 2, a white polyester film having a thickness of 188 to 250 μm is used in many magnetic cards, but the film used in the present invention has flexibility and can be continuously wound by an apparatus. Anything is fine. Of course, it is possible to use a film in which a lower layer including a magnetic layer of a single layer or more is already formed, but in this case, the solvent of the magnetic coating material to be coated soaks into the lower layer, increasing the viscosity of the coating material and increasing the mobility of the magnetic particles. Try to keep it intact.
The magnetic paint coating head device 3 is a system that provides a smooth coated surface that can be used for magnetic recording, although there are various coating methods such as normal gravure coating, reverse roll coating, knife coating, wire bar coating, nozzle coating, hopper coating, etc. Anything is fine.
[0010]
The magnetic coating 4 is used for the production of a normal coating type magnetic recording medium containing magnetic particles such as γ-Fe ₂ O ₃ , Fe ₃ O ₄ , Co-ferrite, Ba-ferrite, Ba-ferrite, iron, Sendust and the like. However, the viscosity of the paint and the volume concentration of the magnetic particles should be generally low so that the magnetic particles can move freely in the paint, in addition to maintaining the fluidity required for coating. Is desirable.
For the magnetic orientation device 6, a counter magnet or a Helmholtz coil is usually used, but either may be used. However, considering the effect of the reversal of the orientation magnetic field on the magnetic particles, the latter is considered to be slightly advantageous for the characteristics.
[0011]
FIG. 3 is a schematic diagram of the simplest configuration of the coating film magnetizing apparatus 5 according to the present invention. The magnetizing device includes a rod-shaped core 5A made of a soft magnetic material and a coil 5B. 5C represents a magnetic field generated when a current is passed. The material of the core 5A may be anything as long as it is a material such as pure iron, permalloy, or sendust used for general cores. In short, the magnetizing apparatus is a method that increases the magnetizing force in the vertical direction of the coating film, for example, a method of opposing the yokes 5A and 5D having the same shape across the coating film substrate as shown in FIG. Alternatively, a ring-type electromagnet in which the coating substrate is sandwiched by a gap is also possible. The shape of the part close to the coating surface of the core is almost rectangular, the width is equal to the track width of the fixed magnetic recording layer to be formed, and the length is appropriately designed to obtain the recording density of the desired fixed magnetic recording pattern Is done. When a signal current flows through the coil, a magnetic pole is generated at the tip of the electromagnet core, and the magnetic particles in the coating film are attracted and blocked. Therefore, the coating film that moves away from the lower portion generates less [sparse] magnetic particles. Conversely, when the current of the coil is turned off, the attraction is released, the magnetic particles that have been held by the magnetic pole until then are released, and a [dense] presence of particles is generated in the coating film. Thus, a [sparse] / [dense] pattern corresponding to the pulse signal flowing through the coil is formed.
[0012]
FIG. 5 is a schematic diagram of the fixed signal reading created as described above.
The reading of the fixed magnetic signal can be used as it is because the signal form resembles a magnetic barcode. That is, as shown in FIG. 5, the normal ring reproducing head 10 is brought into contact with the fixed signal track portion to run the card. If the coercive force of the magnetic particles forming the fixed signal at this time is small, and there is no magnetic pole between the sparsely and densely even if a DC magnetic field is applied, the fixed magnetic signal can be saturated in the bias coil 10A of the ring head. Reading is performed by the reproduction coil 10B while applying a DC bias current. In addition, as shown in FIG. 6, when the magnetic particles have a high coercive force, in addition to the above method, the permanent magnet 11 is brought close in advance, and magnetic poles are generated at the sparse and dense edges of the fixed signal. Reading with the reproduction coil 10B ′ is also possible.
[0013]
FIG. 7 shows an example of the correlation between the signal current flowing through the coil, the density of the formed coating film, and the reproduction output. As an easy-to-understand example, an RZ (return zero) type DC pulse current is listed as the current flowing through the coil. At this time, 1 pulse per unit time corresponds to 0, and 2 pulses correspond to 1. [Sparse] of the magnetic particles occurs during the attracting action associated with the generation of the magnetic pole, and [Dense] occurs according to the disappearance of the magnetic pole. Reproduction output occurs at the edge of the [dense] pattern of the coating. Although the case where the magnetizing signal current waveform of the coil is an RZ type DC signal has been described above, the same result can be obtained even if it is an FM type signal waveform.
[0014]
FIG. 8 is a plan view of an example in which the magnetic recording medium thus manufactured is cut out in a card shape. The card 20 has both a fixed magnetic recording track area 20A and a variable magnetic recording / reproducing area 20B in the same plane of the magnetic recording layer. If necessary, it is easy to form a plurality of fixed magnetic recording tracks on the same plane.
[0015]
【The invention's effect】
A magnetic recording medium having a variable magnetic recording area and one or more non-rewritable fixed magnetic recording areas in the same magnetic recording layer, which can be manufactured by the present invention, is obtained by the above-described manufacturing method. Regardless of the shape and nature, or regardless of whether it is a single layer or a laminated system, the pattern of the fixed signal and the position of the signal track area can be set independently. Therefore, magnetic cards manufactured by the method of the present invention can be widely used from simple and inexpensive ones to complicated and expensive ones in various combinations. Prepaid cards, other gold vouchers, magnetic commuter pass, personal It can be expected to be used in various magnetic card systems that require advanced security functions such as authentication cards. In addition, it can be noted that since the manufacturing apparatus can generally be diverted from the conventional apparatus as it is, the investment for mass production of the product of the present invention is considered to be very small.
[Brief description of the drawings]
FIG. 1 is a schematic view of a magnetic paint coating apparatus according to the present invention.
FIG. 2 is a schematic view showing a change in state of magnetic particles in a magnetic coating material in the process of forming a coating film of a magnetic recording medium according to the present invention.
FIG. 3 is a schematic view of a coating film magnetizing apparatus according to the present invention.
FIG. 4 is a schematic view of another coating film magnetizing apparatus according to the present invention.
FIG. 5 is a schematic diagram of fixed signal reading.
FIG. 6 is a schematic diagram of another reading of a fixed signal.
FIG. 7 is a diagram illustrating an example of a correlation between a signal current flowing through a coil, density of a coating film to be formed, and reproduction output.
FIG. 8 is a plan view of an example in which a magnetic recording medium manufactured by the method of the present invention is cut out in a card shape.
[Explanation of symbols]
1: Support base unwinding part 2: Support base 3: Magnetic paint coating head device,
4: Magnetic paint 5: Magnetic paint magnetizing device 5A: Core 5B: Coil 5C: Magnetic field 5D: Yoke 6: Magnetic orientation device 7: Drying furnace 8: Winding part 10 of applied roll 10: Reproducing head 10A: Bias coil 10 ' : Reproduction head 10B ': Reproduction coil

Claims (3)

When the coated magnetic paint on the support is in an undried state, one or more electromagnets are brought close to any position in the width direction of the coating surface to give a magnetization signal in the vertical direction of the coating surface, And the effect of release causes the magnetic particles in the coating film to be abundant in density, and then subjected to a normal orientation treatment to direct the magnetization easy axis of the magnetic particles in the coating direction, followed by drying and fixing. A method of manufacturing a magnetic recording medium, which is manufactured by the method described above and has a non-rewritable fixed magnetic signal pattern region and a non-fixed magnetic recording region in the same magnetic layer. For providing a magnetic signal in the vertical direction of the coating film at an arbitrary position in the width direction of the coating film surface when the coating part of the magnetic coating material on the support and the magnetic coating material coated on the support are undried A coating film magnetizing device that is composed of one or more electromagnets and causes magnetic particles in the coating film to become dense and dense due to the effect of magnetic attraction and release, and the easy axis of magnetization of the magnetic particles in the coating direction A magnetic paint coating apparatus characterized in that an aligning apparatus and a drying furnace are sequentially and continuously installed. In the same magnetic layer, one or more non-rewritable intrinsic magnetic signal pattern track areas due to the presence or absence of magnetic particles and non-fixed signal recording / reproducing areas in which magnetic particles are uniformly dispersed are combined, and all recording is performed. 2. The magnetic recording medium obtained by the method according to claim 1, wherein the easy magnetization axes of the magnetic particles constituting the layer are oriented in the coating direction.

Images