JPH11212502A - Magnetic display medium and three-dimensional image forming method using this medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming method, by which a visual effect unobtainable by a conventional method is given to an image recorded on a card or the like and a variety of recording information is recorded on the card by recording an image which can be stereoscopically viewed on the card, and to provide a magnetic display medium suitable for this method. SOLUTION: Such a magnetic display medium 10 is used that a display layer where at least flaky magnetic materials 16 are dispersed in a dispersion medium 18 presenting a solid state at a normal temperature and a liquid state at heating is formed on a support body 11. Minute areas of this display layer are selectively heated to put a part of the dispersion medium in the liquid state, and magnetic fields different in directions are locally applied to these areas, and thus, orientation of flaky magnetic materials is controlled, and images different in observation directions are stored to form an image which can be stereoscopically viewed with naked eyes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for displaying a three-dimensional image, and more particularly to a method for displaying thermal energy using a display medium in which a flake-like magnetic material having a greatly different viewing angle depending on an observation direction is dispersed in a dispersion medium. And a method for recording and displaying an image by simultaneously applying magnetic energy.

[0002]

2. Description of the Related Art In recent years, plastic card certificates issued to individuals as seen in identification cards such as employee ID cards and student ID cards, various membership cards, and credit cards (hereinafter simply referred to as ID cards). .) Has been generalized. These ID cards typically include a name, gender, or other information to indicate who owns the card.
In addition to the date of birth, an employee number, student number, member number, etc. are printed. Further, cards having a magnetic recording layer due to the need for embossed data or machine reading for improving the durability of recording are widely used. With the spread of the card, in order to improve the personal identification function for determining whether the owner and the user of the card are the same, the card is printed or pasted on the card to produce a black and white or color face. The number of printers to which photographs are added has increased, and various card printers for individual issuance have been marketed.

Other information recorded on the card includes, for example, machine-readable information using a bar code, a signature that the owner directly writes on a sign bar provided on the card, an outline of a fingerprint, or a holographic pattern.
Etc. It is not an exaggeration to say that the surface of the card has been completely filled with the recorded information. It can be said that the recording on the ID card surface is sufficiently satisfied from the quantitative viewpoint of the content of the information. Therefore, it is required that the card issuance in the future has an unprecedented added value.

[0004] On the other hand, many kinds of entertainment cards for the general public, especially for children, are commercially available in large quantities, and in order to achieve unprecedented visual effects and diversification of recorded contents, combinations with other information have been made. For this purpose, a recording medium and a recording method have been devised, and one of the means is a three-dimensional image expression.

[0005] As a conventional technique for a stereoscopic recording method, for example, there is a method using an auxiliary device such as glasses, such as a method using anaglyph or Pulfrich effect.
However, in the case of a card that is always carried, it is not desirable to use an auxiliary device for observation because the situation in which a person checks the record information of the card cannot be specified. Therefore, a recording means capable of autostereoscopic viewing which does not require auxiliary equipment such as glasses must be adopted.

[0006] The most excellent means of stereoscopic vision that does not require glasses or the like is based on a three-dimensional hologram.
Generally, the hologram seal of the same pattern is attached to all the cards issued by the card issuing company with an adhesive or transferred. However, the method using the hologram has a problem that the manufacturing process is complicated and the manufacturing cost is high, so that it is not suitable for recording individual information such as a face photograph.

Therefore, there is a relief card proposed in Japanese Patent Application Laid-Open No. 58-147397. According to this, by giving an uneven pattern on the surface of the metallic glossy sheet and laminating a transparent plastic sheet on this sheet,
It is said that patterns, characters, etc. emerge three-dimensionally. Further, for example, JP-A-5-158207 and JP-A-5-158207
As disclosed in JP-A-158208, there is a method of automatically constructing a relief pattern using an input image as a motif simply by inputting a two-dimensional gradation image to the computer by an image processing function of the computer. As another method of stereoscopically viewing an image two-dimensionally recorded on a plane, there is a technique called a so-called random dot stereogram. However, these methods do not allow stereoscopic viewing depending on the observer, and cannot reproduce a fine image, so that they cannot be adopted as an image recording technique in which the detailed structure is important such as a face photograph. There is.

[0008] For these reasons, it has not been widespread to date to record and display an image including individual information such as a face photograph in a low-cost and natural way for all persons to view in a stereoscopic manner.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and is intended to provide a stereoscopic image on an information recording medium such as a card. By recording images, it is possible to give an unprecedented visual effect as an image recorded on the information recording medium, and to diversify the information recorded on the information recording medium such as a card. Another object of the present invention is to provide a magnetic display medium as an information recording medium satisfying the above, and a three-dimensional image forming method used for the magnetic display medium.

[0010]

The present invention provides the following inventions to solve the above-mentioned problems. According to a first aspect of the present invention, a display layer formed by dispersing at least a flake-like magnetic material in a dispersion medium that exhibits a solid phase at normal temperature and a liquid phase during heating is formed on a support. And a binocular parallax image is recorded using the display layer.

According to a second aspect of the present invention, a display layer comprising at least a flake-like magnetic material dispersed in a dispersion medium that exhibits a solid phase at normal temperature and a liquid phase during heating is provided on a support. The dispersion medium is placed in a liquid phase state by selectively partially heating a fine region of the display layer of the magnetic display medium with respect to the magnetic display medium formed in the magnetic display medium. A three-dimensional image forming method characterized by applying different magnetic fields in different directions and controlling the orientation of the flake-shaped magnetic material to record different images depending on the observation direction.

According to a third aspect of the present invention, in the three-dimensional image forming method of the second aspect, the heating is performed by using either a laser beam or a thermal head.

According to a fourth aspect of the present invention, there is provided the three-dimensional image forming method according to the second or third aspect, wherein the magnetic field is applied by moving the magnetic field applying means one-dimensionally. It is characterized in that the direction of the line of magnetic force applied to the flake-shaped magnetic material in a minute region is changed.

According to a fifth aspect of the present invention, there is provided the three-dimensional image forming method according to the second or third aspect, wherein the application of the magnetic field is performed by oscillating the magnetic field applying means. It is characterized in that the direction of the line of magnetic force applied to the flake-shaped magnetic material in the region is changed.

According to a sixth aspect of the present invention, in the three-dimensional image forming method according to any one of the second to fifth aspects, the magnetic field is applied by using either a permanent magnet or an electromagnet. It is characterized by performing.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, binocular parallax is basically used as a stereoscopic viewing method. As is known for a long time, the method using binocular parallax is a method that uses two photographs for the left eye and the right eye taken from a slightly distant viewpoint as represented by an anaglyph. This is a method of observing a stereoscopic image by preparing image data and superimposing the two images at the focal position of the eye.

FIG. 1 is a schematic structural view of a display medium according to the present invention on which a stereoscopically visible image is recorded. The magnetic display medium 10 used in the present invention is obtained by sequentially laminating a magnetic display layer 12 and a protective layer 13 on a support 11. Here, the microcapsules are described as a single layer for the purpose of explanation, but there are actually microcapsules, which are fine particles, arranged in the thickness direction.

On the support 11, flake-like magnetic particles 16
And microcapsule 14 containing laser light absorbing substance 17
Was applied to a binder 15 to form a magnetic display layer 12. Here, the microcapsules 14 containing the flake-shaped magnetic particles 16 are obtained by dispersing the flake-shaped magnetic particles 16 and the laser light absorbing substance 17 in a dispersion medium 18 such as wax which shows a solid state at normal temperature, and Is 1
It is prepared by microencapsulation to a size of 0 μm or more and 100 μm or less. As the flake-like magnetic particles 16, a mixture of a kind of magnetic particles can be used and includes, for example, magnetite, irons including ferrite, metals exhibiting soft magnetism such as cobalt and nickel, or containing these elements. Flake magnetic powder of an alloy or a compound may be used. The flake-shaped magnetic particles 16 have a major axis of 5 μm to 30 μm and a thickness of 0.1 μm to 3 μm. The holding force of the flake-shaped magnetic particles 16 is 1,000 Oe (Oe is a unit symbol,
Oersted. ) The size of these microcapsules and the size of the flake-shaped magnetic particles, or the value of the holding power of the flake-shaped magnetic particles 16 is usually preferable in consideration of the practicality of the present invention.

The laser light absorbing substance 17 may be any substance having a light absorption sensitivity in the near infrared region and capable of performing light-to-heat conversion. Examples thereof include polymethine dyes (cyanine), phthalocyanine, and dithiol metal. Complex salts, naphthalocyanines, naphthoquinones, anthraquinones, triphenylmethanes (derivatives), indophenols, aluminum diimmoniums, and the like are used. More specifically,
In the case where the absorption wavelength range is 700 to 800 nm, the trade name IR
-750 (anthraquinone type); manufactured by Nippon Kayaku Co., Ltd., trade name SIR114 (anthraquinone type); manufactured by Mitsui Toatsu Chemicals Co., Ltd., or trade name: CY-20 (cyanine type); manufactured by Nippon Kayaku Co., Ltd. Is 800-900 nm, trade name KIR-103 (phthalocyanine type); manufactured by Mitsui Toatsu Chemicals, trade name PA1005 (dithiol metal complex salt); manufactured by Mitsui Toatsu Chemicals, or trade name NK-29
11 (cyanine type); manufactured by Japan Photographic Dye Laboratories, and having an absorption wavelength range of 900 to 1100 nm, trade name I
RF-1000; manufactured by Fuji Photo Film Co., Ltd., trade name IRG
-003 (diimmonium-based); manufactured by Nippon Kayaku Co., Ltd .; or CIR-1081 (cyanine-based); This laser light absorbing substance 17
Is contained in the microcapsules 14 or contained in the wall.

As the dispersion medium 18, a room temperature (about 10 to 35
(In the range of ° C.) and a fluid state when heated to a temperature exceeding room temperature (in the range of about 40 to 100 ° C.). For example, synthetic waxes such as paraffin wax and polyethylene wax, natural waxes such as carnauba wax and petrolatum, higher fatty acid esters such as butyl stearate, methyl stearate, myristyl myristate and stearyl myristate, or dodecyl alcohol, stearyl alcohol, Higher alcohols such as myristyl alcohol and the like are used alone or in combination.

The microcapsules 14 are formed by dispersing the flake-shaped magnetic particles 16, the laser light absorbing substance 17, the core substance 19 mainly composed of the dispersion medium 18 and the like in a dispersion medium 18 which shows a solid state at normal temperature. Covered with shell material 20,
Alternatively, microcapsulation is performed by covering the core material 19 mainly composed of the flake-shaped magnetic particles 16 and the laser light absorbing material 17 and the dispersion medium 18 with a shell material 20 such as a polymer containing the laser light absorbing material 17. The resin used as the shell material 20 includes commonly used resins,
For example, acrylic resin, methacrylic resin, polystyrene, polyester resin, polyurethane resin, polyurea resin, polyamide resin, epoxy resin, natural resin, etc., can be used alone or in combination of two or more. It is.

The binder 15 for dispersing and disposing the microcapsules 14 is a thermosetting aqueous emulsion resin, for example, a polyurethane resin, a polyester resin, an epoxy resin, or the like. The binder 15 holds and protects the microcapsules 14 formed on the support, and has transparency so that the microcapsules 14 can be seen from the outside.

Next, as the support 11 made of an opaque non-magnetic material, for example, a plastic film such as polyvinyl chloride, polyester film, polyimide film, polyethylene terephthalate film, natural resin, paper, synthetic paper, etc. are used. Can be

Next, as the protective layer 13, an epoxy resin, tetrafluoroethylene or the like, or a synthetic resin such as polyvinyl chloride, polyester, polycarbonate, polymethyl methacrylate, polystyrene or polyethylene terephthalate, or a natural resin is used. Is done. This protective layer 1
3 holds the magnetic display layer 12 formed on the support 11 and also includes the microcapsules 1 in the magnetic display layer 12.
The flake-shaped magnetic particles 16 contained in the light-transmitting member 4 have a light-transmitting property so that they can be seen. The protective layer 13 may be colored in a range that does not affect the display and reading of the lower magnetic display layer 12, or may be provided with a colored layer (not shown) having optical transparency.

The basic principle of recording on the magnetic display medium 10 used in the present invention is as follows.

As shown in FIG. 2, the manufactured magnetic display medium 10 has a microcapsule 14 in which flake-shaped magnetic particles 16 are fixed in a dispersion medium 18 in a uniformly dispersed state. In this state, the flake-shaped magnetic particles 16 are oriented in an arbitrary direction and exhibit a halftone color tone.

FIG. 3 shows a state in which an image is not recorded, that is, a state at the time of erasure or non-recording. Orientation of the flake-like magnetic particles 16 in the microcapsule 14 is performed horizontally on the magnetic display layer 12. It is a figure showing the state made to be made. Erasing is performed by heating the magnetic display layer 12 by a heating means while applying a magnetic field horizontally to the magnetic display layer 12 so that the dispersion medium 18 in the microcapsule 14 is in a molten state, and along the direction of the magnetic field lines of the applied horizontal magnetic field. As a result, the flake-shaped magnetic particles 16 are oriented, and the flake-shaped magnetic particles 16 rotate and move in a direction horizontal to the magnetic display layer 12. As a result, the surface of the flake-like magnetic particles 16 reflects light, so that the surface of the magnetic display layer 12 has a uniform metallic luster and a bright color tone.

On the other hand, as shown in FIG. 4, when the direction of the applied magnetic field is perpendicular to the magnetic display layer 12, heating means (not shown) is applied while applying a magnetic field perpendicular to the magnetic display layer 12. By locally heating the magnetic display layer 12, the dispersion medium 18 in the microcapsule 14 of the heating unit is brought into a molten state, and the flake-like magnetic particles 16 are oriented along the direction of the magnetic field lines of the applied perpendicular magnetic field. Accordingly, the flake-shaped magnetic particles 16 rotate and move in a direction perpendicular to the magnetic display layer 12. As a result, the surface of the heated magnetic display layer 12 hardly reflects incident light,
Absorbed, dark tones. Alternatively, the incident light is transmitted through the magnetic display layer 12 and reflected on the surface of the support 11 to form the support 1.
One color is displayed. Here, by making the color of the surface of the support 11 black, the magnetic display medium 10 can be a monochrome display medium. As a heating means, a thermal head or a laser beam can be used.

The basic principle is that, by using the magnetic display layer 12 having the above-described structure, the viscosity of the dispersion medium 18 in the microcapsule 14 is reduced by heating to make the dispersion medium 18 in a fluid state, whereby the dispersion medium The light-reflective flake-shaped magnetic particles 16 dispersed in the microcapsule 14 can be translated, rotated, or translated and rotated. By applying a magnetic field thereto, the flake-shaped magnetic particles 16 are oriented in the direction of the magnetic field lines of the applied magnetic field.
Microcapsule 1 by natural cooling by the end of heating
The dispersion medium 18 in 4 becomes solid state, and the flake-shaped magnetic particles 16 are fixed while being oriented in the direction of the magnetic field lines of the applied magnetic field. Then, the above-described magnetic display medium 10 used in the present invention is used.
In this case, an image is recorded by the flake-shaped magnetic particles 16 dispersed in the microcapsules 14 only in the heating region being oriented along the direction of the magnetic field lines of the applied magnetic field. And
A difference occurs in the viewing angle of the flake-shaped magnetic particles 16 depending on the orientation direction, and the difference is reflected as a difference in the amount of reflected light, and the image density changes. Note that an area gradation image can be expressed by changing the heating time or the amount of heating energy.

FIG. 5 is a diagram for explaining the principle of stereoscopic image display using the magnetic display medium 10 in which fine flake-like magnetic particles 16 are dispersed in a dispersion medium 18. In the figure, 100 represents the left eye of a person, and 101 represents the right eye.

In FIG. 5, the whole of the flake-shaped magnetic particles 16 dispersed in the microcapsules 14 is schematically illustrated as a single rod for easy understanding. A, B,
C, D, or E indicate those recorded by changing the direction of the magnetic field of the magnetic field applied during heating for each heating area, and the flake-shaped magnetic particles 16 are oriented in different directions. Here, paying attention to the D flaky magnetic particles obliquely oriented, the viewing angle of the D flaky magnetic particles 16 seen by the human left eye 100 is β, and the human right eye 1
When the viewing angle of the flake-shaped magnetic particles 16 at D viewed at 01 is α, α> β, and the image of the flake-shaped magnetic particles 16 reflected on the right eye is better than the same flake-shaped magnetic particle 16 reflected on the left eye. growing. In the positional relationship of FIG.
, The other positions A, B, C, and E are respectively α <β, α <β, α = β, and α>
Becomes β.

For example, flake-like magnetic particles 1 at a certain position
When the eye 6 is oriented in the direction of the line of sight of one eye, the eye looks black because the eye cannot recognize the flake-shaped magnetic particles 16. At the same time, the other eye is observing the flake-shaped magnetic particles 16 at the same position. That is, parallax is generated between the left-eye image and the right-eye image depending on the orientation direction of the flake-shaped magnetic particles 16, and each eye observes a different image. As a result, when observing the magnetic display medium 10 including the flaky magnetic particles 16 oriented obliquely, a three-dimensional image emerges.

At this time, the distance between the human eye and the magnetic display medium 10 is sufficiently large as compared with the size of the flake-shaped magnetic particles 16 dispersed in the microcapsules 14, so that the positions A, C, and E The binocular parallax of the flake-shaped magnetic particles 16 oriented horizontally and vertically to the surface of the magnetic display medium 10 is small, and it is considered that most of the effect is provided by the flake-shaped magnetic particles 16 obliquely oriented. At this time, if the microcapsules 14 are of the order of 10 μm and the heated area is so small that it cannot be distinguished and resolved by the eyes, each eye will see a clear image according to the visual field.

According to this principle, flakes dispersed in the microcapsule 14 are created by creating recording data using two pieces of image data having a parallax corresponding to the left and right eyes, and modulating the direction of the magnetic field. Magnetic particles 1
By orienting 6 in accordance with the recording data, it is possible to perform display capable of stereoscopic viewing. In addition, by incorporating this configuration into a card, an unprecedented visual effect can be provided. In addition, by applying a magnetic field in a horizontal or vertical direction to the surface of the magnetic display medium 10 and recording the characters and the like together, the recorded characters and the like can also be made to emerge.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to specific embodiments.

<Embodiment> Magnetic Display Medium FIG. 6 shows an example of a card, wherein flake-like magnetic particles are dispersed in microcapsules 14 in which flake-like magnetic particles 16 contained in a magnetic display layer 12 of a magnetic display medium 10 are dispersed. FIG. 14 is a diagram illustrating an example of recording an image by controlling 16 orientation directions. In FIG. 6, a magnetic display medium 10 has a magnetic display layer 12 and a protective layer 13 sequentially laminated on a support 11. On the support 11 side of the magnetic display medium 10, a permanent magnet 50 having a magnetic flux density of 1000 Gauss was arranged. On the other hand, a laser device 51 was arranged on the transparent protective layer 13 side of the magnetic display medium 10.

Here, the permanent magnet 50 can be slid in a direction parallel to the surface of the magnetic display medium 10 by an actuator (not shown). By changing the positional relationship with the magnetic display medium 10 by sliding the permanent magnet 50, the direction M (indicated by an arrow in the drawing) of the magnetic field lines penetrating the magnetic display medium 10 is changed from horizontal to vertical. It is. Further, the image data (not shown) has spatial position information for each pixel, converts the parallax data to the orientation angle of the flake-shaped magnetic particles 16, and changes the direction M of the magnetic field lines of the permanent magnet 50 into an actuator (not shown). Drive control.

Recording Procedure Next, the recording procedure will be described. As shown in FIG. 6, let each pixel be a, b, c, d, e, and f. Pixel a
Then, the actuator is driven so as to orient the flake-shaped magnetic particles 16 in a direction perpendicular to the magnetic display medium 10 and slides the permanent magnet 50, and the magnetic flux M is perpendicular to the magnetic display medium 10 at the position of the pixel a. Permanent magnet 50
To stop.

Next, the pixel a is irradiated with a laser beam 52 for a certain time by a polarizer (not shown) of the laser device 51. The laser used preferably has an oscillation wavelength of 700 nm to 1100 nm. However, a laser in the visible light region can be used if the output of the laser is allowed.

When the laser irradiation is performed, the magnetic display medium 10
The laser light is absorbed by the laser light absorbing material 17 in the microcapsule 14 included in the magnetic display layer 12 and heat is generated by the light-heat conversion characteristic, and the heat is dissipated by the dispersion medium also included in the magnetic display layer 12. Heat 18 By heating, the viscosity of the dispersion medium 18 in the microcapsules 14 is reduced, and the dispersion medium 18 is brought into a fluid state, whereby the light-reflective flake-like magnetic particles 16 dispersed in the dispersion medium 18 are dispersed.
Becomes movable or rotatable. Here, the flake-shaped magnetic particles 16 can be oriented in a desired direction by a magnetic field applied in advance. Upon completion of the laser irradiation, the dispersion medium 18 is naturally cooled and returns to a solid phase.

Hereinafter, according to the image data, b, c,
For d, e, and f, as in the case of a, an image can be formed by positioning the permanent magnet 50 and determining the direction M of the line of magnetic force of the permanent magnet 50, followed by laser heating. .

In this embodiment, a permanent magnet is used for applying a magnetic field, but the use of an electromagnet is also included in the present invention. In addition, any means for applying a magnetic field irrespective of DC or AC is applicable to the present invention. The means for controlling the direction of the line of magnetic force is not limited to this embodiment, and rotating the magnet is also included in the present invention. Further, any other method of rotating the magnetic field is applicable to the present invention. Further, by modulating the irradiation time and irradiation intensity of the laser beam 52, the halftone image data of the area gradation can be overlapped, so that not only the geometric pattern but also the shape, color, and density of a human image can be obtained. It is also possible to record an image whose image expression such as light and darkness is complicated.

[0043]

As described above, by employing the medium containing the flake-shaped magnetic material in the microcapsule, parallax is generated between the left-eye image and the right-eye image depending on the orientation direction of the flake-shaped magnetic particles. By recording arbitrary image data as a stereoscopic image based on binocular parallax by observing images with different eyes, recording a card by giving an unprecedented visual effect to images recorded on a card etc. A recording method that provides information diversification could be provided.

Further, since the images of the left eye and the right eye can be recorded in substantially the same area, there is no difference between the convergence and the focal position. That is, since observation can be performed in a natural state, there is an advantage that all persons can observe a stereoscopic image without using a special instrument. Further, the recording device may be relatively simple, no special device for reproduction is required, and there is an advantage that the production cost and the issuance cost are lower than those of the conventional method. In addition, since this medium is rewritable, there is an advantage that a display image can be arbitrarily changed.

In short, by recording a stereoscopically visible image on an information recording medium represented by a card or the like, it is possible to provide an unprecedented visual effect as an image recorded on the information recording medium. And diversification of information recorded on an information recording medium represented by a card and the like, and a magnetic display medium and a three-dimensional image forming method used therefor as an information recording medium satisfying the requirements can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a magnetic display medium on which a stereoscopically visible image is recorded according to the present invention.

FIG. 2 is a sectional view showing an unrecorded state of the magnetic display medium according to the present invention.

FIG. 3 is a cross-sectional view showing a first-stage recording state of the magnetic display medium according to the present invention.

FIG. 4 is a cross-sectional view showing a second-stage recording state of the magnetic display medium according to the present invention.

FIG. 5 is a diagram illustrating the principle of stereoscopic image display using the magnetic display medium according to the present invention.

FIG. 6 is a diagram showing one embodiment for recording an image using the magnetic display medium according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Magnetic display medium 11 ... Support 12 ... Magnetic recording layer 13 ... Protective layer 14 ... Microcapsule 15 ... Binder 16 ... Flake-shaped magnetic particle 17 ... Laser Light absorbing material 18: Dispersion medium 19: Core material 20: Shell material 50: Permanent magnet 51: Laser device 52: Laser beam 100: Left eye 101: Right eye

Claims (6)

[Claims] A display layer formed by dispersing at least a flake-like magnetic material in a dispersion medium which shows a solid phase at normal temperature and shows a liquid phase at the time of heating, and is formed on a support; A magnetic recording medium, wherein a binocular parallax image is recorded using the display layer. 2. A magnetic material comprising a support having a magnetic display layer formed by dispersing at least a flake-like magnetic material in a dispersion medium exhibiting a solid phase at normal temperature and a liquid phase during heating. With respect to the display medium, the dispersion medium is brought into a liquid phase state by selectively heating a minute region of the surface layer of the magnetic display medium selectively. A three-dimensional image forming method, comprising: applying a magnetic field; and controlling the orientation of the flake-shaped magnetic material by these to record different images depending on the observation direction. 3. The three-dimensional image forming method according to claim 2, wherein said heating is performed using either a laser beam or a thermal head. 4. The method according to claim 1, wherein the magnetic field is applied by moving the magnetic field applying means in a one-dimensional manner to change the direction of the magnetic force lines applied to the flake-shaped magnetic material in a minute area to be recorded. The three-dimensional image forming method according to any one of 2 and 3. 5. The method according to claim 2, wherein said magnetic field is applied by oscillating a magnetic field applying means to change the direction of magnetic lines of force applied to the flake-shaped magnetic material in a minute area to be recorded. The three-dimensional image forming method according to any one of the above. 6. The method according to claim 2, wherein the application of the magnetic field is performed using either a permanent magnet or an electromagnet.
6. The three-dimensional image forming method according to any one of claims 1 to 5.