JP2006012390A - Optical information recording medium and image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical information recording medium provided with a reversible display function, and to provide an image processing method using the optical information recording medium. <P>SOLUTION: The optical information recording medium is provided with a substrate, an optical information layer disposed on the substrate and a reversible thermosensitive layer in which at least a part of the information recorded in the optical information layer can be recorded in such a manner that the part of the information can be visually recognized, in this order. The optical information recording medium further has a cushion layer having a film thickness a (μm) between the optical information layer and the reversible thermosensitive layer, a relation of a formula; 0.3≤b/a≤0.8 is satisfied when deformation in a direction vertical to the cushion layer when at least either of the formation and the erasure of an image is performed using an image processing means to the optical information recording medium is defined as b (μm) and the cushion layer has 40 to 100 μm film thickness a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical information recording medium having a reversible display function and an image processing method using the optical information recording medium.

In addition to optical information recording media such as read-only DVDs, recordable DVDs (for example, DVD + R, DVD + RW, DVD-R, DVD-RW, DVD-RAM, etc.) have been put into practical use. The DVD + R and DVD + RW are positioned on the extension of the conventional recordable CD-R and CD-RW (recordable compact disc) technology, and ensure reproduction compatibility with a reproduction-only DVD. The recording density (track pitch, signal mark length), substrate thickness, and the like are designed to meet the DVD conditions from the CD conditions. For example, DVD + R, like CD-R, has an optical recording layer formed by spin-coating a dye on a substrate, and an information recording substrate having a metal reflective layer behind it is formed in the same shape via a bonding material. It is configured to be bonded to the substrate.
In addition, the CD-R is one of the features that has a high reflectance (65%) that satisfies the CD standard. In order to obtain a high reflectance with the above configuration, the optical recording layer is used for recording. It is necessary to satisfy a specific complex refractive index at the reproduction light wavelength. This is true for DVD as well.

  By the way, when the CD-ROM and DVD-ROM are manufactured, data is already recorded, and they are used as reproduction-only optical information recording media. And the index display which shows the recorded data content, and various designs are printed on the surface of the protective layer using ultraviolet curable ink or oil-based ink. These printings are usually performed by screen printing or offset printing. These printing means are so-called large-volume printing means for simultaneously printing a large number of the same pattern.

  On the other hand, when recording electronic information or the like using a write-once type optical information recording medium such as DVD + R, DVD-R, or CD-R, the recorded contents cannot be recognized unless the optical information recording medium is reproduced. Therefore, as index display and various designs, for example, (1) a method of writing using an oil-based felt pen etc. on a protective layer, (2) a method of applying a thin label or the like, and (3) optical information recording An ink receiving layer is provided on the surface of the medium for display recording by the ink jet recording method (see Patent Document 1), and (4) a dye receiving layer is provided on the surface of the optical information recording medium for display recording by the sublimation thermal transfer recording method. The method (refer patent document 2) etc. are proposed.

  On the other hand, rewritable optical information recording media such as DVD + RW, DVD-RW, DVD-RAM, and CD-RW are recorded when an index is displayed and recorded by a felt pen, an ink jet recording method, or a thermal transfer recording method as described above. When the contents are changed, the display cannot be changed, and there is a drawback that the recorded contents are different from the recorded contents and the recorded contents cannot be understood only by looking at the display. In this case, there is a possibility that the optical information recording medium may be damaged if the display is changed by attaching the label according to the change of the recording content using a thin label such as that used in the CD-R.

Further, the optical information recording medium is inserted into the reproducing device, clamped, and rotated while being irradiated with laser light from the side of the data recording / reading surface through the pickup to reproduce the recorded data. In order to perform such insertion / removal to / from the reproducing apparatus and reproduction of recorded data stably and reliably, the optical information recording medium has specifications regarding thickness, warpage amount, and dynamic balance.
By the way, it can be considered that the optical information recording medium is attached to a printing display surface such as a printing medium. However, depending on the amount of warpage of the optical information recording medium, the adhesiveness with the thermal head is deteriorated, and the display of the printing medium is performed. Malfunctions. The adhesion between the print medium and the thermal head also depends on the size of the thermal head. For an optical information recording medium whose warp angle is within ± 0.7 °, a thermal head having a size of 35 mm is used. When the contact is made with the print display medium, the maximum distance between the thermal head and the optical information recording medium becomes as large as 30 to 60 μm, the adhesion with the thermal head is deteriorated, and the image display on the print medium becomes uneven. There is a problem of end.

  Therefore, it is possible to stably and surely reproduce the recorded data in and out of the reproducing apparatus, visually confirm the recorded contents, and easily and visually without damaging the optical information recording medium, and excellent in image uniformity. An optical information recording medium having a reversible display function that can perform at least one of recording, erasing, and rewriting of a display has not been provided yet, and the rapid development thereof is desired at present.

JP-A-5-238005 JP-A-8-48080

  This invention is made | formed in view of this present condition, and makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, the present invention enables stable and reliable reproduction of recorded data and reproduction of recorded data, visual confirmation of recorded contents, and simple and good appearance without damaging the optical information recording medium. It is an object of the present invention to provide an optical information recording medium and an image processing method that are excellent in uniformity and have a reversible display function capable of at least one of recording, erasing, and rewriting of display.

Means for solving the problems are as follows. That is,
<1> A substrate, at least an optical information layer on the substrate, and a reversible thermosensitive layer capable of recording so that at least a part of information recorded on the optical information layer can be visually recognized. An optical information recording medium provided in order, having a cushion layer having a film thickness a (μm) between the optical information layer and the reversible thermosensitive layer, and using an image processing means for the optical information recording medium When the deformation amount in the vertical direction of the cushion layer when performing at least one of image formation and erasure is defined as b (μm), the relationship of 0.3 ≦ b / a ≦ 0.8 is obtained: The optical information recording medium is characterized in that the film thickness a of the cushion layer is 40 to 100 μm.
<2> In the above <1>, the image processing means is a thermal head, and the thermal head is brought into contact with the reversible thermosensitive layer in the optical information recording medium from the vertical direction to perform at least one of image formation and erasure. The optical information recording medium described.
<3> When the amount of deformation of the cushion layer in the vertical direction is b (μm), at least one of image formation and erasure is performed on the optical information recording medium using a thermal head, and the thermal head is removed The optical information recording medium according to <2>, wherein the amount of restoration in the vertical direction of the cushion layer is c (μm), and satisfies the relationship: 0.5 ≦ c / b ≦ 1.
<4> When the film thickness of the reversible thermosensitive layer is d (μm) and the film thickness of the cushion layer is a (μm), <1> to <3 satisfying the following formula: 60 μm ≦ a + d ≦ 200 μm The optical information recording medium according to any one of the above.
<5> The optical information recording medium according to any one of <1> to <4>, wherein a deformation amount b of the cushion layer in a vertical direction is 5 to 60 μm.
<6> The optical information recording medium according to any one of <4> to <5>, wherein the reversible thermosensitive layer has a film thickness d of 25 to 150 μm.
<7> The optical information recording medium according to any one of <1> to <6>, wherein the cushion layer contains at least one of a buffer material and an elastic material.
<8> The optical information recording medium according to any one of <1> to <7>, wherein the color tone of the reversible thermosensitive layer reversibly changes depending on temperature.
<9> The optical information recording medium according to any one of <1> to <8>, wherein the reversible thermosensitive layer contains a resin and an organic low-molecular compound, and the transparency reversibly changes depending on temperature. is there.
<10> The optical information recording medium according to any one of <1> to <8>, wherein the reversible thermosensitive layer contains an electron donating color-forming compound and an electron accepting compound.
<11> The optical information recording medium according to any one of <1> to <10>, wherein the optical information recording medium has a diameter of 80 to 120 mm.
<12> The optical information recording medium according to any one of <1> to <11>, wherein the optical information layer includes an organic dye-containing recording layer.
<13> The optical information recording medium according to any one of <1> to <11>, wherein the optical information layer is formed by laminating a first protective layer, a phase change recording layer, and a second protective layer in this order. is there.
<14> An image forming step of forming an image on the reversible thermosensitive layer by heating the reversible thermosensitive layer in the optical information recording medium according to any one of <1> to <13> with an image processing unit, and Including at least one of an image erasing step of erasing an image of the reversible thermosensitive layer by heating the reversible thermosensitive layer in the optical information recording medium according to any one of <1> to <13> by an image processing unit; The image processing means is a thermal head of size f (mm), and the maximum distance between the thermal head and the optical information recording medium when the thermal head is brought into contact with the optical information recording medium is g (μm). Then, the image processing method is characterized by satisfying the relationship of the following formula: 0.58 ≦ f / g.
<15> The image processing method according to <14>, wherein the thermal head size f is 10 to 60 mm.
<16> The image processing method according to any one of <14> to <15>, wherein a new image is formed while erasing the image using a thermal head.

  In the optical information recording medium of the present invention, it is possible to record the substrate, at least the optical information layer on the substrate, and at least a part of the information recorded on the optical information layer so that it can be visually recognized. A reversible thermosensitive layer is provided in this order, and a cushion layer having a film thickness of a (μm) is provided between the optical information layer and the reversible thermosensitive layer, and image processing means is used for the optical information recording medium. When the deformation amount in the vertical direction of the cushion layer when performing at least one of image formation and erasure is defined as b (μm), the relationship of 0.3 ≦ b / a ≦ 0.8 is obtained: The film thickness a of the cushion layer is 40 to 100 μm. As a result, the stored contents of the optical information recording medium can be visually confirmed, and a uniform image can be easily formed without damaging the information recording medium.

  In the image processing method of the present invention, the reversible thermosensitive layer in the optical information recording medium of the present invention is heated by an image processing means to form an image on the reversible thermosensitive layer, and the optical information recording of the present invention. The image processing means includes at least one of an image erasing step of erasing an image of the reversible thermosensitive layer by heating the reversible thermosensitive layer in the medium with an image processing means, and the image processing means is a thermal head having a size f (mm) When the maximum distance between the thermal head and the optical information recording medium when the thermal head is brought into contact with the optical information recording medium is g (μm), the relationship of 0.58 ≦ f / g is obtained: Fulfill. In the image processing method of the present invention, it is possible to stably and reliably insert and remove the recorded data and reproduce the recorded data, visually confirm the recorded contents of the optical information recording medium, and damage the optical information recording medium. Therefore, it is possible to form a uniform image efficiently with ease and appearance.

  According to the present invention, it is possible to solve various problems in the prior art, to stably and surely reproduce the recorded data and to / from the reproducing apparatus, to visually confirm the storage contents of the optical information recording medium, and to the optical information recording medium. An optical information recording medium and an image processing method provided with a reversible display function capable of recording, erasing, and rewriting display in a simple and good manner without damaging the image.

(Optical information recording medium)
The optical information recording medium of the present invention comprises a substrate, and at least an optical information layer and a reversible thermosensitive layer laminated on the substrate in this order, and a cushion layer is provided between the optical information layer and the reversible thermosensitive layer. And other layers as necessary.

  When forming and erasing an image on the reversible thermosensitive layer in the optical information recording medium having the reversible display function using the same image processing means (heating means), the image processing means includes, for example, Thermal heads and lasers are used. When a thermal head is used as the image processing means (heating means), the adhesiveness between the thermal head and the reversible thermosensitive layer is deteriorated due to the warp or thickness difference that the optical information recording medium normally has, and the print quality is reduced. There is a problem of lowering. In this case, with respect to mechanical characteristics such as the warp angle and the warp amount of the optical information recording medium, the warp angle is within ± 0.7 ° and the warp amount is 300 μm or less in the physical format standard of DVD-Video / ROM. Further, according to the physical format standard of CD-ROM, the warp angle is within ± 0.6 ° and the warp amount is 400 μm or less.

  Here, as shown in FIG. 1, the warping angle refers to a disc surface when a completely flat optical information recording medium is clamped, and a tangent line is drawn on all surfaces of the optical information recording medium to be measured. Is defined as the maximum angle formed by the tangent and the reference plane. Further, the warpage amount means a distance between a reference surface and a part farthest from the reference surface of the optical information recording medium to be measured. When the warp angle and the warp amount are equal to or greater than the above-mentioned standard values, incident light cannot be returned to the pickup after being reflected by the optical information recording medium, and thus the recording information cannot be read. The warp angle and the amount of warp greatly affect the maximum distance g when the thermal head is brought into contact with the optical information recording medium, and are directly related to print quality.

In the present invention, as shown in FIG. 2, a cushion layer 10 having a film thickness a (μm) is provided between the optical information layer 20 and the reversible thermosensitive layer 11, and image processing is performed on the optical information recording medium. The amount of deformation in the vertical direction of the cushion layer when the image is formed and / or erased using the means (that is, when pressure is applied to the optical information recording medium from the vertical direction by the thermal head 30) is b ( (μm), a cushion layer that satisfies the following formula, 0.3 ≦ b / a ≦ 0.8 is provided. In this case, the cushion layer preferably satisfies the following formula, 0.5 ≦ b / a ≦ 0.8.
Here, the conditions for actually printing and erasing the reversible thermosensitive layer in the optical information recording medium using a thermal head are, for example, about 2-3 seconds at a pressure of 1.8 N.

  The cushion layer has a film thickness a (μm) of 40 to 100 μm, more preferably 50 to 80 μm. The deformation amount b (μm) in the vertical direction of the cushion layer is preferably 5 to 60 μm, and more preferably 10 to 40 μm. As a result, a gap is generated between the optical information recording medium and the thermal head, and the print quality can be maintained by using a cushion layer that satisfies the above value even if it is not completely adhered. Furthermore, if the cushion layer is not sufficiently restored by repeated printing and erasing using a thermal head and a ceramic heater, the cushion layer will not return to its original thickness, and the cushion layer thickness will decrease. There is a concern that the effect as a layer cannot be obtained.

Therefore, in the present invention, as shown in FIG. 3, the amount of deformation of the cushion layer 10 in the vertical direction is b (μm), and an optical information recording medium is formed and / or erased using a thermal head. When the thermal head is removed (that is, when printing is finished, specifically, when the pressure by the thermal head 30 from the direction perpendicular to the reversible thermosensitive layer of the optical information recording medium is removed). When the amount of restoration in the vertical direction of the cushion layer is c (μm), the cushion layer is provided so as to satisfy the relationship of the following formula, 0.5 ≦ c / b ≦ 1. As a result, even if printing and erasing are repeated, the effect as a cushion layer can be maintained and the printing quality can be maintained. In this case, it is more preferable that the cushion layer satisfies the following formula: 0.85 ≦ c / b ≦ 1.
The restoration amount c of the cushion layer is not particularly limited and can be appropriately selected according to the purpose, and is preferably 8.5 to 40 μm.

The cushion layer contains at least one of a cushioning material and an elastic material, and further contains other components as necessary.
There is no restriction | limiting in particular as said buffer material or an elastic material, According to the objective, it can select suitably, For example, a urethane resin, a soft polyethylene resin, a polyvinyl acetate resin, a nitrile butadiene rubber etc. are mentioned.
The cushion layer can be formed by ordinary means such as a solution coating method. Examples of the coating method include conventional coating methods such as spraying, roller coating, dipping, and spin coating.

It is preferable that an adhesive layer is provided between the optical information layer and the reversible thermosensitive layer and below the cushion layer. The material for the adhesive layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, urea resin, melamine resin, phenol resin, epoxy resin, vinyl acetate resin, vinyl acetate-acrylic copolymer Polymer, ethylene-vinyl acetate copolymer, acrylic resin, polyvinyl ether resin, vinyl chloride-vinyl acetate copolymer, polystyrene resin, polyester resin, polyurethane resin, polyamide resin, chlorinated polyolefin resin , Polyvinyl butyral resin, acrylic ester copolymer, methacrylic ester copolymer, natural rubber, cyanoacrylate resin, silicone resin, and the like. These may be used individually by 1 type and may use 2 or more types together.
There is no restriction | limiting in particular as a film thickness of the said adhesion layer, According to the objective, it can select suitably, 10-50 micrometers is preferable and 20-40 micrometers is more preferable.

In the optical information layer of the optical information recording medium of the present invention, the recording layer is not particularly limited as long as the recording layer generates some optical change upon irradiation with laser light, and information can be recorded by the change, and the phase change recording layer Or any of the organic dye-containing recording layers.
FIG. 4 shows a basic configuration of an optical information recording medium (DVD + RW, DVD-RW medium) having a phase change recording layer in the present invention. 1 is a substrate, 2 is a first protective layer (inorganic protective layer), 3 is a recording layer, 4 is a second protective layer (inorganic protective layer), 5 is a reflective layer, 6 is a third protective layer (organic protective layer), 7 is an adhesive layer, 8 is a cover substrate, 9 is an adhesive layer, 10 is a cushion layer, and 11 is a reversible thermosensitive layer, and recording / reproduction is performed by light from the surface of the substrate 1. A guide groove as shown in FIG. 6 is formed on the substrate surface.

-Phase change recording layer-
The phase change type recording layer material used in the present invention uses phase change type optical recording like DVD + RW and CD-RW, and forms amorphous marks by rapidly irradiating the recording layer with laser light. To do. As a recording layer material, a chalcogen alloy thin film such as Ge—Te, Ge—Te—Sb, Ge—Sn—Te, etc. is often used, but an Sb—Te eutectic thin film is recorded (amorphized). Since the sensitivity, speed, and erase ratio are extremely good, it is suitable as a phase change recording layer material. These phase change recording layer materials can be added with other elements and impurities such as Ag, In and Ge for the purpose of further improving performance and reliability.

The film thickness of the phase change recording layer is not particularly limited and may be appropriately selected depending on the purpose, and is preferably 50 to 200 mm (5 to 20 nm). When the film thickness of the phase change type recording layer is less than 5 nm, the repetitive recording characteristics may deteriorate, and when it exceeds 20 nm, the transmittance may decrease.
As the method for forming the phase change recording layer, various vapor phase growth methods such as vacuum deposition, sputtering, plasma CVD, photo CVD, ion plating, and electron beam deposition are used. Among these, the sputtering method is excellent in mass productivity and film quality.

-1st protective layer and 2nd protective layer-
The first protective layer 2 and the second protective layer 4 have effects such as preventing deterioration and deterioration of the phase change recording layer 3, increasing the adhesive strength of the phase change recording layer 3, and enhancing the recording characteristics. . Examples of the material for the protective layer include metal oxides such as SiO, SiO ₂ , ZnO, SnO ₂ , Al ₂ O ₃ , TiO ₂ , In ₂ O ₃ , MgO, and ZrO ₂ , Si ₃ N ₄ , AlN, Nitrides such as TiN, BN, ZrN, sulfides such as ZnS, In ₂ S ₃ , TaS ₄ , carbides such as SiC, TaC, B ₄ C, WC, TiC, ZrC, diamond-like carbon (DLC), or These mixtures are mentioned. Among these, a mixture of ZnS and SiO ₂ is preferable. The mixture of ZnS and SiO ₂ is excellent in heat resistance, low thermal conductivity, and chemical stability, has a small residual stress in the film, and has a recording sensitivity, an erasure ratio, etc. even when at least one of recording and erasing is repeated. It is preferable in that it is difficult to cause deterioration of characteristics and has excellent adhesion to the recording layer.
The first protective layer 2 and the second protective layer 4 can be formed by various vapor deposition methods such as vacuum vapor deposition, sputtering, plasma CVD, photo CVD, ion plating, electron beam vapor deposition. The law is used. Among these, the sputtering method is excellent in mass productivity and film quality.
The thicknesses of the first protective layer 2 and the second protective layer 4 are not particularly limited and can be appropriately selected according to the purpose. The thickness of the first protective layer is usually preferably 50 to 90 nm.

-Reflective layer-
While the reflective layer serves as a reflective layer, it also serves as a heat radiating layer that releases heat applied to the recording layer by laser light irradiation during recording. Since the formation of the amorphous mark greatly depends on the cooling rate by heat dissipation, the selection of the reflective layer is particularly important in the high linear velocity compatible optical recording medium.
As the material of the reflective layer 6, for example, a metal material such as Al, Au, Ag, Cu, Ta, or an alloy thereof can be used. Moreover, Cr, Ti, Si, Cu, Ag, Pd, Ta, etc. can be used as an additive element to these metal materials. Among these, it is preferable to contain either Ag or an Ag alloy. This is because the reflective layer constituting the phase change optical information recording medium usually has a thermal conductivity viewpoint that adjusts a cooling rate of heat generated during recording, and an optical that improves the contrast of a reproduction signal by using an interference effect. From a general point of view, a metal with high thermal conductivity / high reflectance is desirable, and pure Ag or Ag alloy has a very high thermal conductivity of Ag of 427 W / m · K, and immediately after the recording layer reaches a high temperature during recording, This is because a rapid cooling structure suitable for forming an amorphous mark can be realized.
Note that pure silver is the best in view of the high thermal conductivity in this way, but Cu may be added in consideration of corrosion resistance. In this case, in order not to impair the characteristics of Ag, the addition amount range of copper is preferably 0.1 to 10 atomic%, particularly preferably 0.5 to 3 atomic%. On the other hand, excessive addition of copper deteriorates the corrosion resistance of Ag.
The reflective layer 6 can be formed by various vapor deposition methods, for example, vacuum deposition, sputtering, plasma CVD, photo CVD, ion plating, electron beam deposition, and the like. Among these, the sputtering method is excellent in mass productivity and film quality.
Although the heat dissipation capability of the reflective layer is basically proportional to the thickness of the layer, the thickness of the reflective layer is preferably 60 to 300 nm.
A resin protective layer can be provided on the reflective layer as necessary. The resin protective layer has an effect of protecting the recording layer in the process and when it becomes a product, and is usually formed of an ultraviolet curable resin. The thickness of the resin protective layer is preferably 2 to 5 μm.

-Third protective layer-
It is preferable to provide the 3rd protective layer 5 which does not contain sulfur as a barrier layer between the said protective layer and the said reflection layer.
Examples of the material of the third protective layer 5 include Si, SiC, SiN, GeN, and ZrO _2. Among these, Si or SiC is preferable in terms of particularly high barrier properties.
When pure Ag or an Ag alloy is used for the reflective layer, when a protective layer containing sulfur such as a mixture of ZnS and SiO ₂ is used, there is a problem that sulfur diffuses into Ag and causes disk defects (Ag sulfide). reaction). Therefore, as the third protective layer for preventing such a reaction, (1) it has a barrier ability to prevent the sulfurization reaction of Ag, (2) it is optically transparent to laser light, (3 ) Select an appropriate material from the viewpoints of low thermal conductivity, (4) good adhesion to the protective layer and the reflective layer, and (5) easy formation to form amorphous marks. Desirably, a material mainly composed of Si or SiC that satisfies the above requirements is preferable as a constituent material of the third protective layer.
The thickness of the third protective layer is preferably 2 to 20 nm, and more preferably 2 to 10 nm. If the film thickness is less than 2 nm, it may not function as a barrier layer, and if it exceeds 20 nm, the degree of modulation may be reduced.

-Board-
As the material of the substrate 1, glass, ceramics, resin, or the like is usually used, but a resin substrate is preferable in terms of moldability and cost. Examples of the resin include polycarbonate resin, acrylic resin, epoxy resin, polystyrene resin, acrylonitrile-styrene copolymer resin, polyethylene resin, polypropylene resin, silicone resin, fluorine resin, ABS resin, and urethane resin. Among these, polycarbonate resin and acrylic resin are preferable in terms of moldability, optical characteristics, and cost. These may be used individually by 1 type and may use 2 or more types together.

The substrate is provided with a guide groove having irregularities as shown in FIG. One of the features of recording media that can be played back by a CD player such as DVD + R and CD-R is that track information is recorded by wobbling guide grooves or pit rows in a meandering manner. The meandering state of the guide groove can be detected from the track signal as a wobble signal, and the track information is recorded in advance on the substrate by FM modulation or phase modulation of a predetermined frequency. The track information is address information, disk rotation frequency information, and the like. When detected from the track signal, the track information is easily separated from the information data signal and has a feature of easily obtaining ROM signal compatibility. A preferable groove depth formed on the substrate is 100 to 400 mm (10 to 40 nm), and a groove width is 0.1 to 0.35 μm.
Note that the adhesive layer for bonding the substrate on which the information signal is written and the bonding substrate are formed of a double-sided adhesive sheet, a thermosetting resin, or an ultraviolet curable resin in which an adhesive is applied to both sides of the base film. . The thickness of the adhesive layer is usually preferably about 50 μm.
The bonding substrate (dummy substrate) does not have to be transparent when an adhesive sheet or a thermosetting resin is used as an adhesive layer, but a transparent substrate that transmits ultraviolet rays when an ultraviolet curable resin is used for the adhesive layer. And The thickness of the bonding substrate is usually 0.6 mm, which is the same as that of the transparent substrate 1 on which information signals are written.

  FIG. 5 shows a basic configuration of an optical information recording medium (DVD + R, DVD-R medium) using an organic dye material for the recording layer. 1 is a substrate, 3 is a dye-containing recording layer, 5 is a reflective layer, 6 is a protective layer (organic protective layer), 7 is an adhesive layer, 8 is a cover substrate, 9 is an adhesive layer, 10 is an elastic layer, and 11 is a reversible feeling It is a thermal layer, and recording / reproduction is performed by light from the substrate 1 surface side. A guide groove as shown in FIG. 6 is formed on the substrate surface.

-Dye-containing recording layer-
The dye-containing recording layer is capable of producing some optical change upon irradiation with laser light, and can record information by the change. The dye-containing recording layer contains at least an organic dye, and includes a binder, a stabilizer, and the like. It contains.
The organic dye is configured to obtain a high reflectivity by the multiple interference effect at both interfaces of the dye recording layer. The dye-containing recording layer must have optical characteristics having a large refractive index n and a relatively small absorption k. Preferred ranges are n> 2, 0.03 <k <0.2. Such optical characteristics can be obtained by utilizing the characteristics of the long wavelength end of the light absorption band of the dye recording layer. Examples of the organic dyes include cyanine dyes, phthalocyanine dyes, pyrylium / thiopyrylium dyes, azurenium dyes, squarylium dyes, azo dyes, formazan chelate dyes, metal complex salt dyes such as Ni and Cr, Examples thereof include naphthoquinone dyes, anthraquinone dyes, indophenol dyes, indoaniline dyes, triphenylmethane dyes, triallylmethane dyes, aminium dyes / diimmonium dyes, and nitroso compounds. Among these, as the dye compound having the maximum absorption wavelength of the light absorption spectrum of the film in the range of 550 to 650 nm and easily obtaining desired optical characteristics at the laser light wavelength (about 650 nm), film forming properties and optical characteristics by solvent coating can be used. Therefore, at least one kind of dye selected from a tetraazaporphyrazine dye, a cyanine dye, an azo dye, and a squarylium dye is preferable.

In addition, a polymer material can be blended in the dye. As the polymer material, for example, various materials such as ionomer resin, polyamide resin, vinyl resin, natural polymer compound, silicone, liquid rubber, or silane coupling agent may be dispersed and mixed. Alternatively, stabilizers (for example, transition metal complexes), dispersants, flame retardants, lubricants, antistatic agents, surfactants, plasticizers, and the like can be used together for the purpose of improving characteristics.
The film thickness of the dye-containing recording layer is preferably 100 to 5000 mm (10 to 500 nm), more preferably 500 to 2000 mm (50 to 200 nm). When the film thickness is less than 100 mm (10 nm), the recording sensitivity may decrease, and when it exceeds 5000 mm (500 nm), the reflectance may decrease.

The recording layer can be formed by ordinary means such as vapor deposition, sputtering, CVD, or solution coating. When the coating method is used, the dye is dissolved in an organic solvent or the like, and is performed by a conventional coating method such as spraying, roller coating, dipping, or spin coating.
The organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, alcohols such as methanol, ethanol, isopropanol, 2,2,3,3-tetrafluoropropanol; acetone, methyl ethyl ketone, Ketones such as cyclohexanone; amides such as N, N-dimethylformamide and N, N-dimethylacetamide; sulfoxides such as dimethyl sulfoxide; ethers such as tetrahydrofuran, dioxane, diethyl ether and ethylene glycol monomethyl ether; methyl acetate; Esters such as ethyl acetate; Aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethane, carbon tetrachloride, and trichloroethane; Aromatics such as benzene, xylene, monochlorobenzene, and dichlorobenzene ; Methoxyethanol, cellosolves such as ethoxyethanol; hexane, pentane, cyclohexane, and the like hydrocarbons such as methylcyclohexane. These may be used individually by 1 type and may use 2 or more types together.

-Undercoat layer-
The undercoat layer includes (1) improved adhesion, (2) a barrier such as water or gas, (3) improved storage stability of the recording layer, (4) improved reflectance, and (5) from a solvent. And (6) formation of guide grooves, guide pits, preformats, and the like.
For the purpose of (1), polymer materials such as ionomer resins, polyamide resins, vinyl resins, natural resins, natural polymer compounds, silicones, liquid rubbers, and various other polymer substances, and silane cups A ring agent or the like can be used. For the purposes (2) and (3), in addition to the polymer material, an inorganic compound such as SiO ₂ , MgF ₂ , SiO, TiO ₂ , ZnO, TiN, SiN, etc., and also a metal or semimetal For example, Zn, Cu, Ni, Cr, Ge, Se, Au, Ag, Al, or the like can be used. For the purpose (4), metals such as Al and Ag, and organic thin films having a metallic luster such as methine dyes and xanthene dyes can be used. For the purposes (5) and (6), an ultraviolet curable resin, a thermosetting resin, a thermoplastic resin, or the like can be used.
There is no restriction | limiting in particular in the film thickness of the said undercoat layer, According to the objective, it can select suitably, 0.01-30 micrometers is preferable and 0.05-10 micrometers is more preferable.

-Reflective layer and substrate-
As the material for the reflective layer and the substrate, the same materials as those for the optical information recording medium having the phase change recording layer can be used.

-Protective layer and substrate surface hard coat layer-
The protective layer or the substrate surface hard coat layer is (1) protection from scratches, dust, dirt, etc. of the recording layer (reflection / absorption layer), (2) improvement in storage stability of the recording layer (reflection / absorption layer), (3) Used for the purpose of improving the reflectance. As the material of the protective layer or the substrate surface hard coat layer, an inorganic material or an organic material is used. Examples of the inorganic material include SiO and SiO ₂ . There is no restriction | limiting in particular as said organic material, According to the objective, it can select suitably from well-known ultraviolet curable resin, For example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meta) ) Acrylate, hydroxypentyl (meth) acrylate, phenoxyhydroxypropyl (meth) acrylate, chlorohydroxypropyl (meth) acrylate, diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, Dipropylene glycol mono (meth) acrylate, poropropylene glycol mono (meth) acrylate, glycerin mono (meth) acrylate, glycerin di (meth) acrylate DOO, pentaerythritol (meth) acrylate, phenyl glycidyl ether (meth) acrylate, dipentaerythritol penta (meth) acrylate, etc. acrylate resin di (meth) acrylate of bisphenol A epoxy resin. These may be used individually by 1 type and may use 2 or more types together.
Examples of the radical initiator for UV curing include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2.2-diethoxyacetophenone, 4-phenoxy-2. Acetophenone series such as 2-dichloroacetophenone; propiophenone series such as 2-hydroxy-2-methylpropiophenone; anthraquinone series such as 2-chloroanthraquinone; thioxanthone series such as 2.4-diethylthioxanthone, etc. It is done. At least one of the composition ratio and the mass ratio of the radical initiator overcoat forming material is usually preferably 1 to 10%. These may be used individually by 1 type and may use 2 or more types together.

Moreover, you may add a crosslinkable monomer to these resin. Examples of the crosslinkable monomer include trimethylolpropane tri (meth) acrylate, acrylated isocyanurate, 1.4 butanediol di (meth) acrylate, 1.6 hexanediol di (meth) acrylate, neopentyl glycol di ( And (meth) acrylate, dicyclopentadienyl di (meth) acrylate, pentaerythritol tetra (meth) acrylate, and the like. These may be used individually by 1 type and may use 2 or more types together. Moreover, you may add thickeners, such as an antifoamer and a silica, as needed.
There is no restriction | limiting in particular in the film thickness of the said substrate surface hard-coat layer, According to the objective, it can select suitably, 1-30 micrometers is preferable.

  In the present invention, as in the case of the organic dye-containing recording layer, the undercoat layer, the protective layer, and the substrate surface hard coat layer may further include a stabilizer, a dispersant, a flame retardant, a lubricant, a charge, depending on the purpose. An inhibitor, a surfactant, a plasticizer, and the like can be contained.

-Adhesive, adhesive layer-
The adhesive is not particularly limited as long as it is a material capable of bonding two recording media, and can be appropriately selected according to the purpose, and is irradiated with ultraviolet rays such as an ultraviolet curable adhesive or a cationic ultraviolet curable adhesive. Therefore, an adhesive that exhibits adhesive ability (ultraviolet curable adhesive) is suitable. Moreover, you may use the ultraviolet curing adhesive which exhibits an adhesive ability by irradiating a photoinitiator (initiator) with an ultraviolet-ray. The ultraviolet curable adhesive is applied to at least one of the two substrates to be bonded by spin coating or the like on the surface to be bonded.
There is no restriction | limiting in particular in the film thickness of the said ultraviolet curing adhesive, According to the objective, it can select suitably, 5-50 micrometers is preferable.

−Protection board−
When the protective substrate is irradiated with laser light from the protective substrate side, the protective substrate must be transparent to the laser light to be used, and when used as a simple protective plate, transparency is not an issue. Usable substrate materials are the same as the above substrate materials, for example, polyester resins, acrylic resins, polyamide resins, polycarbonate resins, polyolefin resins, phenol resins, epoxy resins, polyimide resins and other plastics, glass, ceramics, metals, etc. Can be used.

<Reversible thermosensitive layer>
The reversible thermosensitive layer in the optical information recording medium of the present invention comprises at least a reversible thermosensitive recording layer capable of recording so that at least a part of information recorded on the optical information layer can be visually recognized. And other layers as necessary. For example, as shown in FIG. 7, the reversible thermosensitive layer 11 includes a support 12, a reversible thermosensitive recording layer 13, and a protective layer 14, which are printed by contacting a thermal head from the protective layer 14 side. And erasing can be performed.

  The material of the reversible thermosensitive recording layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include an electrochromic material, a photochromic material, a thermochromic material, a magnetic recording material, and bidirectional stability (Bistable). ) Liquid crystal materials, thermoreversible recording materials, and the like. Among these, by applying energy, it becomes the first transparency or color tone, and by applying the same or different energy again, it becomes the second transparency or color tone, and the above-mentioned first and second transparency or color tone are energy. What can hold | maintain without applying is preferable. In this case, examples of the energy to be applied include light, heat, electric field, magnetism, and the like, but a reversible thermosensitive layer using thermal energy is preferably used in terms of stability and cost.

  The reversible thermosensitive recording layer is not particularly limited and may be any layer as long as the transparency and color tone are reversibly changed by heat, but at least one of color tone and transparency is different at room temperature without application of energy. It is preferable that two or more forms can be maintained. In the present invention, “the color tone reversibly changes depending on the temperature” means a phenomenon in which a visible change is reversibly caused by a temperature change, and is relative to the difference in heating temperature and cooling rate after heating. This means that a colored state and a decolored state can be formed. For example, two or more kinds of polymers are mixed and changed to transparent and cloudy depending on their compatibility state (Japanese Patent Laid-Open No. Sho 61-255883), and those utilizing the phase change of liquid crystal polymer (Japanese Patent Laid-Open No. Sho) No. 62-66990), a first color state is obtained at a first specific temperature higher than room temperature, the second color is obtained by heating at a second specific temperature higher than the first specific temperature and then cooling. The thing which will be in the state of this is mentioned.

The resin used for the reversible thermosensitive recording layer material preferably has a glass transition temperature (Tg) of 60 to 120 ° C, more preferably 70 to 100 ° C. If the glass transition temperature is too low, the heat resistance of the image may be lowered, and if it is too high, the erasability may be lowered.
There is no restriction | limiting in particular as resin used for the said reversible thermosensitive recording layer material, According to the objective, it can select suitably, For example, a polyvinyl chloride resin, a vinyl chloride-vinyl acetate copolymer, vinyl chloride-acetic acid Vinyl chloride copolymers such as vinyl-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer, vinyl chloride-acrylate copolymer; polyvinylidene chloride resin, vinylidene chloride-vinyl chloride copolymer, Vinylidene chloride copolymers such as vinylidene chloride-acrylonitrile copolymer; polyester resin; polyamide resin; polyacrylate resin or polymethacrylate or acrylate, methacrylate copolymer; silicone resin, polyethylene resin, polypropylene resin, polystyrene resin, polyacrylamide Resin, Polyvinyl Rupiroridon resin, natural rubber, polyvinyl alcohol resins, polyacrolein resins, polycarbonate resins. These may be used individually by 1 type and may use 2 or more types together. Among these, polyvinyl chloride resin, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer, vinyl chloride-acrylate copolymer, etc. The vinyl chloride copolymer is particularly preferred.

  Furthermore, in order to improve repeated durability, it is preferable to crosslink the resin, and as a method for crosslinking, it is preferable to use heat, ultraviolet rays, or an electron beam. When crosslinking the resin, various crosslinking agents may be used. For example, in the case of thermal crosslinking, there is a method of crosslinking by combining a resin having an hydroxyl group such as vinyl chloride-vinyl acetate-vinyl alcohol copolymer with a material having an isocyanate group, and in the case of ultraviolet crosslinking or electron beam crosslinking. Includes a method of crosslinking using an acrylic or methacrylate monomer or oligomer together with a resin, but is not limited thereto. These resins, crosslinking agents and crosslinking methods are described in JP-A No. 64-62368, JP-A No. 3-227688, JP-A No. 7-96679 and JP-A No. 7-172072.

  On the other hand, the organic low molecular weight substance used for the reversible thermosensitive recording layer material is not particularly limited as long as it is in the form of particles in the reversible thermosensitive recording layer. In general, the melting point is preferably 30 to 200 ° C, and preferably 50 to 200 ° C. Is more preferable. As such an organic low molecular weight substance, a long-chain hydrocarbon-containing compound having a long-chain hydrocarbon is preferable. 6-50 are preferable, as for carbon number of the said long chain hydrocarbon, 8-40 are more preferable, and 10-30 are especially preferable. This carbon number may be divided into two or more places in one molecule, and represents the total carbon number of hydrocarbon chains in one molecule.

  The organic low molecular weight material is preferably used in combination of a low melting point material and a high melting point material. The temperature difference between the melting points of the low melting point organic low molecular substance and the high melting point low molecular substance is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, and particularly preferably 50 ° C. or higher. By using a combination of organic low-molecular substances having different melting points, the range of the temperature at which the material becomes transparent can be expanded. The melting point of the low melting point organic low molecular weight substance is preferably 50 ° C. or higher, more preferably 70 ° C. or higher, particularly preferably 80 ° C. or higher. In this case, the upper limit is preferably less than 100 ° C. When the melting point of the low melting point organic low molecular weight substance is increased, the image heat resistance is improved. 100-200 degreeC is preferable, as for melting | fusing point of the said high-low-melting-point organic low molecular weight substance, 120-180 degreeC is more preferable, and 130-170 degreeC is especially preferable. When the melting point of the high melting point organic low molecular weight material is increased, the temperature difference from the melting point of the low melting point organic low molecular weight material is widened, the transparency temperature range is widened, and it becomes easy to be transparent even if the processing speed is increased. When the melting point of the low molecular weight material is lowered, the sensitivity of image formation may be improved.

The low-melting-point organic low-molecular substance is not particularly limited and can be appropriately selected according to the purpose. For example, fatty acid ester, dibasic acid ester, polyhydric alcohol difatty acid ester, ketone having a higher alkyl group, Examples include fatty acids, alkylamides, and alkylureas. These may be used individually by 1 type and may use 2 or more types together.
The high melting point organic low molecular weight substance is not particularly limited and may be appropriately selected depending on the intended purpose. For example, an aliphatic saturated dicarboxylic acid, a semicarbazone derived from a ketone having a higher alkyl group, an α-phosphono fatty acid , Fatty acid amide, aliphatic bisamide, alicyclic dicarboxylic acid, fatty acid having a steroid skeleton, and the like. These may be used alone or in combination of two or more.

Examples of these organic low-molecular substances include JP-A-2-1363, JP-A-3-2089, JP-A-5-77549, JP-A-5-96850, JP-A-5-124343, All known materials and known combinations described in, for example, Kaihei 5-294602, JP-A-6-48024, and JP-A-8-20167 can be used.
The mixing mass ratio of these low melting point organic low molecular substances and high melting point organic low molecular substances is preferably 95: 5 to 5:95, more preferably 90:10 to 10:90, and particularly preferably 80:20 to 20:80. preferable. The ratio of the organic low molecular weight substance and the resin in the reversible thermosensitive layer is preferably about 1: 2 to 1:16, more preferably 1: 2 to 1: 8, and more preferably 1: 2 to 1: 4. Is more preferable. When the ratio of the resin is less than this, it may be difficult to form a film in which the organic low molecular weight substance is held in the resin. Can be difficult.

  In addition to the above components, additives such as surfactants and plasticizers can be added to the reversible thermosensitive recording layer in order to facilitate the formation of a transparent image. These are disclosed in, for example, JP-A Nos. 63-104879 and 63-178079.

Next, a reversible thermosensitive recording material capable of color development and decoloration using an electron donating color developing compound (for example, leuco dye) and an electron accepting compound (developer) will be described in detail. The reversible thermosensitive recording material is formed by dispersing a leuco dye and a developer in a resin binder.
The leuco dye is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a triphenylmethane phthalide compound, a fluoran compound, a phenothiazine compound, a leucooramine compound, an indinophthalide compound Compound etc. are mentioned.
The developer includes a structure having a color developing ability for developing a leuco dye in a molecule, such as a phenolic hydroxyl group, a carboxylic acid group, and a phosphate group, and a structure that controls cohesion between molecules, such as a long It is a compound having a structure in which chain hydrocarbon groups are linked. The connecting part may be via a divalent group containing a hetero atom, and the long chain hydrocarbon group may contain a divalent group or an aromatic group containing a hetero atom. Specifically, a known developer described in JP-A-5-124360 can be used. The melting point of the developer is preferably 120 to 200 ° C, and more preferably 140 to 180 ° C. If the melting point of the developer is too low, the erasability may be lowered, and if it is too high, the energy required for image formation is increased and the sensitivity may be lowered.

FIG. 8 shows the relationship between the color density and temperature of a composition obtained by dispersing a leuco dye and a developer in a resin binder. First, when gradually heated a composition in the decolorized state (A), a molten colored state occurs coloration at temperatures T ₁ begins to melt (B). When rapidly cooled from the melt color state (B), the color state can be lowered to room temperature and a solid color state (C) is obtained. Whether or not this color development state is obtained depends on the rate of temperature decrease from the molten state, and in slow cooling, the color disappears during the temperature decrease, and the same color disappearance state (A) or rapid color development state (C ) A relatively low concentration state is formed. On the other hand, quenched coloring state again raising the (C) will and decoloration occurs with a color temperature lower than temperature T ₂ and (D to E), returns from here to the same colorless state, including when the temperature decreases (A).

  There is no restriction | limiting in particular as said support body, According to the objective, it can select suitably, For example, a polyimide film, an aramid film, a polyphenyl sulfide film, a polyester film etc. are mentioned. The thickness of the support is preferably 3 to 250 μm, more preferably 10 to 150 μm, and still more preferably 20 to 100 μm. If the support is too thin, it may cause problems such as wrinkles when coating and drying the reversible thermosensitive recording layer or when a label is applied. If the support is too thick, the disk drive may store information. Or there may be a problem in reading.

The material of the protective layer is preferably a resin, and more preferably a curable resin such as a thermosetting resin, an ultraviolet curable resin, or an electron beam curable resin. Specific examples include silicone rubber, silicone resin (Japanese Patent Laid-Open No. 63-221087), polysiloxane graft polymer, ultraviolet curable resin, electron beam curable resin (Japanese Patent Laid-Open No. 3-205655), and the like. When heating by contacting a thermal head or the like, it is particularly necessary to protect the surface from being damaged from both heat and mechanical stress.
There is no restriction | limiting in particular in the thickness of the said protective layer, According to the objective, it can select suitably, 0.1-20 micrometers is preferable and 0.5-10 micrometers is more preferable.

In the present invention, as shown in FIG. 9, the film thickness d of the reversible thermosensitive layer (the total thickness of the support 12 + reversible thermosensitive recording layer 13 + protective layer 14) varies depending on the materials used, 1.0-200 micrometers is preferable and 25-150 micrometers is more preferable. When the film thickness of the cushion layer is a (μm), it is preferable to satisfy the following formula: 60 μm ≦ a + d ≦ 200 μm, and more preferably 75 μm ≦ a + d ≦ 150 μm. As a result, since the thickness of CD discs, CD-R discs, CD-RW discs and DVD video discs that are currently widely distributed in the world is about 1.2 mm, the infrastructure of the world can be used in common.
As shown in FIG. 10, the optical information recording medium of the present invention has an information area (outside of the stack rib) and a clamping area (inside of the stack rib), and is formed in a donut disk shape. The diameter is 80-120 mm. As a result, the world's infrastructure can be used in common.

(Image processing method)
The image processing method of the present invention comprises an image forming step of forming an image on the reversible thermosensitive layer by heating the reversible thermosensitive layer in the optical information recording medium of the present invention by an image processing means, and the optical information recording medium of the present invention. In which the reversible thermosensitive layer is heated by an image processing means to erase at least one of the image erasing process of erasing the image of the reversible thermosensitive layer, and further appropriately selected as necessary, for example, It has a conveyance process, a control process, etc.

There is no restriction | limiting in particular as said image processing means, According to the objective, it can select suitably, For example, a thermal head, a laser, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
There is no restriction | limiting in particular as preset temperature of the said thermal head, According to the objective, it can select suitably, For example, 110 degreeC or more is preferable, 112 degreeC or more is more preferable, and 115 degreeC or more is especially preferable.

  By using the thermal head, the size can be further reduced, the power consumption can be reduced, and a battery-driven handy type device can also be realized. Also, a single thermal head can be used for recording and erasing the image. In this case, the size can be further reduced. When recording and erasing with one thermal head, once all the previous images are erased, a new image may be recorded again, or the energy is changed for each image and the previous image is erased at one time. An overwrite method for recording images is also possible. In the overwrite method, the time required for recording and erasing the image is reduced, leading to an increase in recording speed.

  Here, as shown in FIG. 11, the thermal head has the same size (length) as the thermal head if the thermal head length f (mm) is short in an optical information recording medium having the same curvature. Is brought into contact with the optical information recording medium, the maximum distance g (μm) between the thermal head and the optical information recording medium becomes small, and satisfies the relationship of the following equation: 0.58 ≦ f / g, and 0.75 ≦ f / It is more preferable to satisfy the relationship of g. Thereby, print quality can be maintained.

The transporting step is not particularly limited as long as it has a function of sequentially transporting the reversible thermosensitive recording medium, and can be appropriately selected according to the purpose. For example, the transporting belt, the transporting roller, and the transporting belt can be transported. Combination with a roller, etc. are mentioned.
The control step is not particularly limited as long as it has a function of controlling each step, and can control each step. Examples thereof include devices such as a sequencer and a computer.

  The optical information recording medium and the image processing method of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
A substrate having a guide groove uneven pattern having a depth of about 1700 mm, a width of about 0.21 μm, and a track pitch of 0.74 μm was prepared on the surface of a polycarbonate resin disk having a diameter of 120 mm and a thickness of 0.6 mm.
On this substrate, squarylium dye compound is applied. A recording layer made of an organic dye having a thickness of 800 mm (80 nm) was formed by dissolving in tetrafluoropropanol and spin-coating as a coating solution. On this organic dye-containing recording layer, a reflective layer made of Ag was formed to a thickness of 1400 mm (140 nm) by sputtering using Ar as a sputtering gas. A protective layer made of an ultraviolet curable resin was formed on the reflective layer so as to have a thickness of 4 μm. Subsequently, it bonded together with the cover board with the ultraviolet curable adhesive (The Nippon Kayaku Co., Ltd. make, KARAYAD DVD003), and produced the part (optical information layer) corresponded to 20 of FIG.

  Next, a label having a reversible thermosensitive layer in which a transparent state and a cloudy state change by heating was produced. First, aluminum (Al) was vacuum-deposited on a support made of a transparent polyaramid film having a thickness of 50 μm (Aramika 50R, manufactured by Teijin Ltd.) to a thickness of about 600 mm to provide a reflective layer. On the reflective layer, a vinyl chloride-vinyl acetate-phosphate ester copolymer (Denka Vinyl # 1000P, manufactured by Denki Kagaku Kogyo Co., Ltd.) was dissolved in a 1: 1 mixed solvent of methyl ethyl ketone (MEK) and toluene, dried by heating, and then thickened. The adhesive layer was formed so as to be about 1 μm.

  Next, 9 parts by mass of behenic acid (manufactured by Sigma, reagent, purity 99%), 0.5 parts by mass of 1,4-ciscyclohexyldicarboxylic acid (manufactured by Tokyo Chemical Industry Co., Ltd., reagent), 1,4-transcyclohexyldicarboxylic 0.5 parts by weight of acid (manufactured by Tokyo Chemical Industry Co., Ltd., reagent), 27 parts by weight of vinyl chloride-vinyl acetate-vinyl alcohol copolymer (manufactured by Dow Chemical Co., Ltd., VAGH), isocyanate compound (manufactured by Nippon Polyurethane Industry Co., Ltd., A reversible thermosensitive recording layer coating solution consisting of 3 parts by weight of coronate HL, 250 parts by weight of tetrahydrofuran (THF), and 20 parts by weight of toluene is coated on the adhesive layer and dried by heating to form a layer having a thickness of about 10 μm. After that, the resin was cross-linked by leaving it in an environment of 60 ° C. for 24 hours to provide a reversible thermosensitive recording layer.

Next, 10 parts by mass of 75 mass% butyl acetate solution of urethane acrylate UV curable resin (Dainippon Ink Chemical Co., Ltd., Unidic C7-157), 1 mass of calcium carbonate (Shiraishi Kogyo Co., Ltd., Brilliant 15) And a coating solution consisting of 10 parts by mass of toluene is uniformly dispersed, and the obtained dispersion solution is applied onto the reversible thermosensitive recording layer with a wire bar and cured with an 80 W / cm ultraviolet lamp to obtain a thickness of about A protective layer of 3 μm was provided. Thus, a reversible thermosensitive layer corresponding to 11 in FIG. 5 was produced.
Next, a cushion layer coating solution made of urethane resin was applied to the back surface of the reversible thermosensitive layer to form a cushion layer having a thickness of 40 μm. An acrylic adhesive layer coating solution was applied to the lower side of the cushion layer to form an adhesive layer having a thickness of 29 μm.
Finally, the optical information layer and the reversible thermosensitive layer were bonded together using a jig to produce an optical information recording medium with a reversible display function of the present invention.

  Using a thermal head (made by Kyocera, print width 35 mm × 60 mm, resolution 305 dpi) on the reversible thermosensitive layer of the obtained optical information recording medium, pressure (about 1.8 N) is applied from about 2 to 3 from the vertical direction. The maximum distance g between the reversible thermosensitive layer and the thermal head when printing was performed over a period of time was 25 μm. The amount of deformation b in the vertical direction of the cushion layer was 32 μm. When the printing on the optical information recording medium was completed (when the pressure from the vertical direction was removed), the restoration amount c in the vertical direction of the cushion layer was 19 μm.

(Example 2)
In Example 1, an optical information recording was performed in the same manner as in Example 1 except that a cushion layer made of urethane resin was provided to a thickness of 40 μm and the optical information layer and the reversible thermosensitive layer were bonded together. A medium was made.
When printing was performed on the reversible thermosensitive layer of the obtained optical information recording medium under the same conditions as in Example 1 using a thermal head having a length of 35 mm (pressure was applied from the vertical direction). The maximum distance g between the reversible thermosensitive layer and the thermal head was 30 μm. The amount of deformation b in the vertical direction of the cushion layer was 32 μm. When the printing on the optical information recording medium was completed (when the pressure from the vertical direction was removed), the restoration amount c in the vertical direction of the cushion layer was 19 μm.

Example 3
In Example 1, optical information was obtained in the same manner as in Example 1 except that a cushion layer made of urethane resin was provided to have a thickness of 60 μm and the optical information layer and the reversible thermosensitive layer were bonded together. A recording medium was produced.
When printing was performed on the reversible thermosensitive layer of the obtained optical information recording medium under the same conditions as in Example 1 using a thermal head having a length of 60 mm (pressure was applied from the vertical direction). The maximum distance g between the reversible thermosensitive layer and the thermal head was 40 μm. Further, the deformation amount b of the cushion layer in the vertical direction was 48 μm. Further, when the printing on the optical information recording medium was finished (when the pressure from the vertical direction was removed), the restoration amount c in the vertical direction of the cushion layer was 29 μm.

Example 4
Optical information recording was performed in the same manner as in Example 1 except that the cushion layer made of urethane resin was provided to have a thickness of 70 μm and the optical information layer and the reversible thermosensitive layer were bonded together in Example 1. A medium was made.
When printing was performed on the reversible thermosensitive layer of the obtained optical information recording medium under the same conditions as in Example 1 using a thermal head having a length of 35 mm (pressure was applied from the vertical direction). The maximum distance g between the reversible thermosensitive layer and the thermal head was 25 μm. The amount of deformation b in the vertical direction of the cushion layer was 56 μm. When the printing on the optical information recording medium was completed (when the pressure from the vertical direction was removed), the restoration amount c in the vertical direction of the cushion layer was 34 μm.

(Example 5)
In Example 1, an optical information recording medium was produced in the same manner as in Example 1 except that the maximum distance g between the reversible thermosensitive layer and the thermal head was adjusted to 70 μm.
When printing was performed on the reversible thermosensitive layer of the obtained optical information recording medium under the same conditions as in Example 1 using a thermal head having a length of 35 mm (pressure was applied from the vertical direction). The amount of deformation b of the cushion layer in the vertical direction was 32 μm. When the printing on the optical information recording medium was completed (when the pressure from the vertical direction was removed), the restoration amount c in the vertical direction of the cushion layer was 19 μm.

(Comparative Example 1)
In Example 2, optical information was obtained in the same manner as in Example 2 except that the cushioning layer made of urethane resin was provided to have a film thickness of 10 μm and the optical information layer and the reversible thermosensitive layer were bonded together. A recording medium was produced.
When printing was performed on the reversible thermosensitive layer of the obtained optical information recording medium under the same conditions as in Example 1 using a thermal head having a length of 35 mm (pressure was applied from the vertical direction). The maximum distance g between the reversible thermosensitive layer and the thermal head was 30 μm. The amount of deformation b in the vertical direction of the cushion layer was 8 μm. Further, when the printing on the optical information recording medium was finished (when the pressure from the vertical direction was removed), the restoration amount c in the vertical direction of the cushion layer was 5 μm.

(Comparative Example 2)
In Example 1, an optical information recording medium was produced in the same manner as in Example 1 except that the optical information layer and the reversible thermosensitive layer were bonded together without providing the cushion layer.
When printing was performed on the reversible thermosensitive layer of the obtained optical information recording medium under the same conditions as in Example 1 using a thermal head having a length of 35 mm (pressure was applied from the vertical direction). The maximum distance g between the reversible thermosensitive layer and the thermal head was 25 μm. Further, the deformation amount b in the vertical direction of the cushion layer was 5 μm. Further, when the printing on the optical information recording medium was finished (when the pressure from the vertical direction was removed), the restoration amount c in the vertical direction of the cushion layer was 3 μm.

(Comparative Example 3)
In Example 1, except that the cushioning layer made of a soft polyethylene resin was provided so that the film thickness was 30 μm and the optical information layer and the reversible thermosensitive layer were bonded together, An information recording medium was produced.
When printing was performed on the reversible thermosensitive layer of the obtained optical information recording medium under the same conditions as in Example 1 using a thermal head having a length of 35 mm (pressure was applied from the vertical direction). The maximum distance g between the reversible thermosensitive layer and the thermal head was 25 μm. The amount of deformation b in the vertical direction of the cushion layer was 6 μm. Further, when the printing on the optical information recording medium was finished (when the pressure from the vertical direction was removed), the restoration amount c in the vertical direction of the cushion layer was 3 μm.

(Comparative Example 4)
Optical information recording was performed in the same manner as in Example 1 except that a cushion layer made of urethane resin was provided to have a thickness of 105 μm and the optical information layer and the reversible thermosensitive layer were bonded together in Example 1. A medium was made.
When printing was performed on the reversible thermosensitive layer of the obtained optical information recording medium under the same conditions as in Example 1 using a thermal head having a length of 35 mm (pressure was applied from the vertical direction). The maximum distance g between the reversible thermosensitive layer and the thermal head was 25 μm. The amount of deformation b in the vertical direction of the cushion layer was 21 μm. Further, when the printing on the optical information recording medium was finished (when the pressure from the vertical direction was removed), the restoration amount c in the vertical direction of the cushion layer was 11 μm.

(Comparative Example 5)
Optical information recording was performed in the same manner as in Example 1 except that a cushion layer made of urethane resin was provided to have a thickness of 180 μm and the optical information layer and the reversible thermosensitive layer were bonded together in Example 1. A medium was made.
When printing was performed on the reversible thermosensitive layer of the obtained optical information recording medium under the same conditions as in Example 1 using a thermal head having a length of 35 mm (pressure was applied from the vertical direction). The maximum distance g between the reversible thermosensitive layer and the thermal head was 25 μm. Further, the deformation amount b in the vertical direction of the cushion layer was 162 μm. Further, when the printing on the optical information recording medium was finished (when the pressure from the vertical direction was removed), the restoration amount c in the vertical direction of the cushion layer was 100 μm.

<Image uniformity evaluation test>
About each obtained optical information recording medium, a part of information (for example, date, time, etc.) recorded using a DVD + R / RW drive (manufactured by Ricoh Co., Ltd., MP5240A) is recorded as recording means (thermal head). Using a recording apparatus having an erasing means (ceramic heater), the recording energy of the thermal head was adjusted in accordance with the recording temperature change of each medium, displayed and recorded on the heat sensitive layer, and visualized. Then, after erasing the image formed at this time using a ceramic heater, the image quality was measured again using a reflection densitometer (Macbeth RD914) for the print quality recorded on the reversible display recording layer with a thermal head. Evaluated. The evaluation standard for the image uniformity was 0.9 or more as “◯”, 0.4 or more and less than 0.9 as “Δ”, and less than 0.4 as “x”.

<Evaluation test of recording characteristics>
Thereafter, recording was performed with a DVD + R / RW drive [MP5240A, manufactured by Ricoh Co., Ltd.], and a DVD signal (8/16 modulation signal) was measured, and a parity of inner code error (parity of inner code error, hereinafter referred to as “PIE”). ”), Parity of Outer Code Fail (hereinafter referred to as“ POF ”), and jitter, the recording characteristics were evaluated based on whether the physical format standard of DVD-Video / ROM was satisfied. Here, according to the physical format standard of DVD-Video / ROM with respect to the recording / reproducing signal, PIE is 280 or less, POF is 0 or less, and jitter is 9% or less. As the evaluation criteria for the recording characteristics, “◯” indicates that all standards of PIE, POF, and jitter are satisfied, and “x” indicates that none of the standards satisfy the standards.

表１の結果から、比較例１〜４は、サーマルヘッドと可逆表示記録層との間のわずかなギャップ量、クッション層の膜厚、垂直方向への変形量などによって密着性が損なわれ、画像均一性を確保できないことが認められた。また、比較例５では、画像均一性は保たれているが、記録特性においてディスク厚みの影響から規格外になっていることが認められた。
これに対し、実施例１〜５は、再生装置への出し入れや記録データの再生が安定的にかつ確実に行え、特に、実施例１〜４では、光情報記録媒体の記憶内容を目視で確認でき、しかも光情報記録媒体にダメージを与えることなく簡便、かつ体裁良く、表示を記録、消去、及び書き換えを行うことができる可逆表示機能を備えた光情報記録媒体及び画像処理方法を提供できることが確認できた。

From the results shown in Table 1, in Comparative Examples 1 to 4, the adhesion is impaired by the slight gap amount between the thermal head and the reversible display recording layer, the thickness of the cushion layer, the amount of deformation in the vertical direction, and the like. It was found that uniformity could not be ensured. In Comparative Example 5, the image uniformity was maintained, but it was recognized that the recording characteristics were out of specification due to the influence of the disc thickness.
On the other hand, in Examples 1 to 5, it is possible to stably and reliably insert and remove the recorded data and playback of recorded data. In particular, in Examples 1 to 4, the storage contents of the optical information recording medium are visually confirmed. In addition, it is possible to provide an optical information recording medium and an image processing method having a reversible display function capable of recording, erasing, and rewriting the display without causing damage to the optical information recording medium. It could be confirmed.

  The optical information recording medium of the present invention can be stably and reliably put in and out of a reproducing apparatus and recorded data can be confirmed visually, and the optical information recording medium can be easily and without damaging the optical information recording medium. Since it has a reversible display function that can be recorded, erased, and rewritten, it is suitable for various optical information recording media such as CD-R, CD-RW, and DVD. .

FIG. 1 is an explanatory diagram for explaining the definition of a warp angle and a warp amount in an optical information recording medium. FIG. 2 is a diagram showing the relationship between the amount of deformation of the cushion layer in the vertical direction when pressure is applied to the optical information recording medium from the vertical direction. FIG. 3 is a diagram showing the relationship of c with respect to the amount of restoration of the cushion layer in the vertical direction when the pressure from the vertical direction on the optical information recording medium is removed. FIG. 4 is an explanatory diagram showing an example of the layer structure of the optical information recording medium with a reversible display function of the present invention. FIG. 5 is an explanatory diagram showing another example of the layer structure of the optical information recording medium with a reversible display function of the present invention. FIG. 6 is an explanatory view showing guide grooves on the substrate surface. FIG. 7 is a schematic cross-sectional view showing an example of the layer configuration of the reversible thermosensitive layer. FIG. 8 is an explanatory diagram for explaining the principle of coloring and decoloring of the reversible thermosensitive layer. FIG. 9 is a diagram showing the relationship between the film thickness d of the reversible thermosensitive layer and the film thickness a of the cushion layer. FIG. 10 is a plan view showing an example of an optical information recording medium with a reversible display function of the present invention. FIG. 11 is a diagram showing the relationship between the size f of the thermal head and the maximum distance g between the thermal head and the optical information recording medium when the thermal head is brought into contact with the optical information recording medium.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 1st protective layer 3 Recording layer 4 2nd protective layer 5 Reflective layer 6 3rd protective layer 7 Adhesive layer 8 Cover substrate 9 Adhesive layer 10 Cushion layer 11 Reversible thermosensitive layer 12 Support body 13 Reversible thermosensitive recording layer 14 Protective layer 20 Optical information layer 30 Thermal head

Claims (16)

  A substrate, at least an optical information layer on the substrate, and a reversible thermosensitive layer capable of recording so that at least part of information recorded on the optical information layer can be visually recognized are provided in this order. An optical information recording medium comprising a cushion layer having a thickness of a (μm) between the optical information layer and the reversible thermosensitive layer, and image processing means is used for the optical information recording medium. When the amount of deformation in the vertical direction of the cushion layer when performing at least one of formation and erasure is defined as b (μm), the following relationship is satisfied: 0.3 ≦ b / a ≦ 0.8, and An optical information recording medium, wherein the cushion layer has a thickness a of 40 to 100 μm.   2. The optical information according to claim 1, wherein the image processing means is a thermal head, and the thermal head is brought into contact with the reversible thermosensitive layer in the optical information recording medium from the vertical direction to perform at least one of image formation and erasure. recoding media.   The cushion layer when the amount of deformation in the vertical direction of the cushion layer is b (μm), and at least one of image formation and erasure is performed on the optical information recording medium using a thermal head, and the thermal head is removed. The optical information recording medium according to claim 2, wherein a relationship of 0.5 ≦ c / b ≦ 1 is satisfied, where c is a recovery amount in the vertical direction.   4. The system according to claim 1, wherein the thickness of the reversible thermosensitive layer is d (μm) and the thickness of the cushion layer is a (μm), and the relationship of the following formula, 60 μm ≦ a + d ≦ 200 μm is satisfied. Optical information recording medium.   The optical information recording medium according to any one of claims 1 to 4, wherein a deformation amount b of the cushion layer in a vertical direction is 5 to 60 µm.   6. The optical information recording medium according to claim 4, wherein the film thickness d of the reversible thermosensitive layer is 25 to 150 [mu] m.   The optical information recording medium according to claim 1, wherein the cushion layer contains at least one of a buffer material and an elastic material.   8. The optical information recording medium according to claim 1, wherein the color tone of the reversible thermosensitive layer reversibly changes depending on the temperature.   The optical information recording medium according to any one of claims 1 to 8, wherein the reversible thermosensitive layer contains a resin and an organic low molecular weight compound, and the transparency reversibly changes depending on the temperature.   The optical information recording medium according to any one of claims 1 to 8, wherein the reversible thermosensitive layer contains an electron-donating color-forming compound and an electron-accepting compound.   The optical information recording medium according to claim 1, wherein the diameter of the optical information recording medium is 80 to 120 mm.   The optical information recording medium according to claim 1, wherein the optical information layer has an organic dye-containing recording layer.   The optical information recording medium according to claim 1, wherein the optical information layer is formed by laminating a first protective layer, a phase change recording layer, and a second protective layer in this order.   An image forming step of forming an image on the reversible thermosensitive layer by heating the reversible thermosensitive layer in the optical information recording medium according to any one of claims 1 to 13 by an image processing unit, and any one of claims 1 to 13 Including at least one of an image erasing step of erasing an image of the reversible thermosensitive layer by heating the reversible thermosensitive layer in the optical information recording medium according to claim 1, wherein the image processing means has a size f ( mm), and when the maximum distance between the thermal head and the optical information recording medium when the thermal head is brought into contact with the optical information recording medium is g (μm), the following formula: 0.58 An image processing method characterized by satisfying a relationship of ≦ f / g.   The image processing method according to claim 14, wherein a size f of the thermal head is 10 to 60 mm. The image processing method according to claim 14, wherein a new image is formed while erasing the image using a thermal head.

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