JP5206046B2 - Photochromic composition, image display medium, image forming apparatus, and image erasing apparatus - Google Patents

Description

  The present invention relates to a photochromic composition, an image display medium, an image forming apparatus, and an image erasing apparatus. More specifically, the present invention relates to a photochromic composition capable of repeatedly forming an image by light irradiation and heat treatment, an image display medium, and the same. The present invention relates to an image forming apparatus and an image erasing apparatus.

  As a method of forming a color image using a photochromic compound, for example, in Patent Document 1 (Japanese Patent Laid-Open No. 5-271649), yellow-orange is irradiated with 254 nm ultraviolet light, red is irradiated with 313 nm ultraviolet light, and 365 nm ultraviolet light is irradiated. A method has been proposed in which three types of photochromic diarylethene compounds that develop a blue-violet color upon irradiation are mixed and irradiated with ultraviolet light of each wavelength. In order to form a full-color image, it is necessary to control the extinction / color development of three or more photochromic compounds that develop the three primary colors (blue, green, red or yellow, magenta, cyan) with light. It is necessary to be able to select whether or not each material is colored according to the three types of ultraviolet light wavelength range, that is, three or more types of photochromic compounds that do not overlap in the absorption band in the ultraviolet region are required. Although the three primary colors must be shown in the state, no system of such compounds is found in practice. For practical use, it is necessary to consider not only the color development characteristics but also the repeated durability and heat / humidity stability, and it is very difficult to develop a material satisfying all of these.

  In Patent Document 2 (Japanese Patent Application Laid-Open No. 7-199401), all photochromic compounds were colored with 366 nm ultraviolet light with respect to three types of photochromic fulgide compounds showing yellow, magenta, and cyan in a colored state. A method for obtaining a color image by selectively erasing each photochromic fulgide compound as necessary by irradiating white light through a color positive film later has been proposed. Although this method has the advantage that only one type of ultraviolet light source can be used, it requires a color positive film for the image to be formed, and it is not practical to prepare it each time. Not suitable for use in image output. Furthermore, the image formed in this way is gradually discolored by the illumination light and the image is lost.

  In addition, in the case where a photochromic compound is used for an image display medium, one of the problems that must be overcome is that a formed image is held for a long time under visible light. So far, preservation of the color development state of photochromic compounds has been studied. Although the use is an optical recording material, Patent Document 3 (Japanese Patent Laid-Open No. Sho 62-147455) and Patent Document 4 (Japanese Patent Laid-Open Publication No. Sho 62-1461979) associate the colored state (photomerocyanine) of a spiropyran compound, Increases the storage stability of the chromophore.

  However, when used as an image display medium, the above-mentioned aggregate is erased at about 60 ° C., and thus the formed image is erased at a high temperature in the living environment. In addition, spiropyran compounds generally tend to be unable to ensure sufficient strength in various durability such as repeated durability of color development and decoloration and storage stability in a decolored state and a colored state.

Japanese Patent Laid-Open No. 5-271649 JP 7-199401 A Japanese Patent Laid-Open No. 62-147455 JP-A-62-146979

  The present invention has been made in view of the above-described state of the art and problems, can form an image by light, can be erased by light or heat treatment, and can be repeatedly formed and erased. It is another object of the present invention to provide a rewritable multicolor image display medium and a multicolor image method that are excellent in image retention and excellent in image retention.

  The photochromic composition of the present invention includes a photochromic compound represented by the following general formula (I) and a compound having a long chain structure.

（ただし、Ｒ_１、Ｒ_２、Ｒ_３、Ｒ_４はアルキルであり、Ｒ_１、Ｒ_２の炭素数の合計、およびＲ_３、Ｒ_４の炭素数の合計がともに１２以上である。ＸおよびＹはそれぞれ独立して水素結合性基または会合性基を１つあるいは複数含む構造である。Ｚ_１、Ｚ_２は存在しないか、あるいは−ＣＨ_２ＯＣＯ−、−ＮＨＣＯ−、−Ｏ−、−ＯＣＯ−の中から選択される１つであり、Ｒ_５〜Ｒ_１６は独立して水素であるかまたは置換基である。）

(However, R ₁ , R ₂ , R ₃ , R ₄ are alkyl, and the total number of carbon atoms of R ₁ , R ₂ and the total number of carbon atoms of R ₃ , R ₄ are both 12 or more. X and Y is each independently a structure containing one or more hydrogen bonding groups or associative groups, Z ₁ and Z ₂ do not exist, or —CH ₂ OCO—, —NHCO—, —O—, — OCO- is one selected from RCO and R _{5 to} R ₁₆ are independently hydrogen or a substituent.)

  The image display medium of the present invention is characterized in that a display layer made of the above-described photochromic composition is formed on a support substrate.

  Furthermore, the image display medium of the present invention is characterized in that the display layer contains two or more kinds of photochromic compounds having different hues in the associated state.

  The image display medium of the present invention displays a first photochromic compound exhibiting a yellow hue in an associated state, a second photochromic compound exhibiting a magenta hue, and a third photochromic compound exhibiting a cyan hue. Each photochromic compound contained in the layer is composed of the above-described photochromic composition.

  In the image display medium of the present invention, the display layer includes a display layer containing only the first photochromic compound, a display layer containing only the second photochromic compound, and a display layer containing only the third photochromic compound. It is a laminated structure.

  An image forming apparatus of the present invention includes an ultraviolet light irradiation unit that partially irradiates the above image display medium with ultraviolet light, and a heating unit that raises the display layer to a predetermined temperature necessary for image stabilization. It is characterized by that.

  The image forming apparatus of the present invention also includes a rotation driving means for rotationally driving an optical disk having an optical disk label recording surface including the above-described image display medium, and an ultraviolet light that partially irradiates the optical disk label recording surface with ultraviolet light. It is characterized by comprising a light irradiation means and a heating means for raising the temperature to a predetermined temperature necessary for image stabilization.

  Furthermore, the image forming apparatus of the present invention includes an ultraviolet light irradiation unit that partially irradiates the image display medium with ultraviolet light, and a heating unit that raises the display layer to a predetermined temperature necessary for image stabilization. And heating means for raising the temperature of the display layer to a predetermined temperature necessary for erasing the formed image.

  The image forming apparatus of the present invention also includes a rotation driving means for rotationally driving an optical disc having an optical disc label recording surface including the portion of the image display medium, and ultraviolet light is partially applied to the display layer of the optical disc label recording surface. Irradiating ultraviolet light irradiation means, heating means for raising the display layer to a predetermined temperature necessary for image stabilization, and heating means for raising the display layer to a predetermined temperature necessary for erasing the formed image It is characterized by that.

  In addition, the image forming apparatus of the present invention comprises an ultraviolet light irradiation means for irradiating the display layer with ultraviolet light on the image display medium, and a visible wavelength region corresponding to the maximum absorption wavelength of each photochromic compound in a colored state. Visible light irradiation means for irradiating light and heating means for raising the temperature of the display layer to a predetermined temperature necessary for image stabilization are provided.

  An image forming apparatus according to the present invention includes a rotation driving unit that rotates an optical disc having an optical disc label recording surface including the image display medium portion, and an ultraviolet ray that irradiates the display layer of the optical disc label recording surface with ultraviolet light. Light irradiation means, visible light irradiation means for irradiating visible light in a wavelength range corresponding to the maximum absorption wavelength of each photochromic compound in a colored state, and heating means for raising the display layer to a predetermined temperature necessary for image stabilization It is characterized by providing.

  Further, the image forming apparatus of the present invention comprises an ultraviolet light irradiation means for irradiating the display layer with ultraviolet light on the image display medium, and a visible wavelength region corresponding to the maximum absorption wavelength of each photochromic compound in a colored state. Visible light irradiation means for irradiating light, heating means for raising the display layer to a predetermined temperature necessary for image stabilization, and heating means for raising the display layer to a predetermined temperature necessary for erasing the formed image; It is characterized by providing.

  An image forming apparatus according to the present invention includes a rotation driving unit that rotates an optical disc having an optical disc label recording surface including the image display medium portion, and an ultraviolet ray that irradiates the display layer of the optical disc label recording surface with ultraviolet light. Light irradiation means, visible light irradiation means for irradiating visible light in a wavelength range corresponding to the maximum absorption wavelength of each photochromic compound in a colored state, and heating means for raising the display layer to a predetermined temperature necessary for image stabilization And heating means for raising the temperature of the display layer to a predetermined temperature necessary for erasing the formed image.

  The image erasing apparatus of the present invention is characterized by comprising heating means for raising the temperature of the display layer to a predetermined temperature necessary for erasing the formed image with respect to the image display medium.

  The image erasing apparatus of the present invention further comprises heating means for raising the temperature of the display layer to a predetermined temperature necessary for erasing the formed image with respect to the optical disc label recording surface including the portion of the image display medium. Features.

  According to the first aspect of the present invention, the storage stability and the repetitive durability against rewriting are improved, the stability against the heat in the associated state is improved, and the light is not affected by the use environment temperature or the apparatus internal temperature. An image forming material capable of imparting sufficient stability to the above can be obtained.

  According to the second aspect of the present invention, the storage stability and the repeated durability against rewriting are excellent, and sufficient stability to light can be imparted without being affected by the use environment temperature or the apparatus internal temperature. An image display medium is obtained.

  According to the invention described in claim 3, it is possible to display a plurality of colors having different hues without being affected by storage stability and repetitive durability against rewriting, and without being affected by the use environment temperature or the temperature in the apparatus. In addition, the color retention of the formed image can be improved.

  According to the invention described in claim 4, it is excellent in storage stability and repetitive durability against rewriting, and it is possible to impart sufficient stability to light without being affected by the use environment temperature or the apparatus internal temperature. An image display medium is obtained and full color display is possible.

  According to the fifth aspect of the present invention, in addition to the above-described effects, an appropriate laminated structure without mixed fat stains of materials between the display layers can be obtained, and appropriate color display can be performed for each display layer.

  According to the invention described in claim 6, it is excellent in storage stability and repetitive durability against rewriting with respect to a medium including a sheet mold, and is sufficient for light without being affected by the use environment temperature or the apparatus internal temperature. Thus, a monochrome image forming apparatus capable of imparting a high degree of stability can be obtained.

  According to the seventh aspect of the present invention, the optical disk type medium is excellent in storage stability and repeated durability against rewriting, and is sufficiently stable against light without being affected by the use environment temperature or the apparatus internal temperature. Thus, a monochrome image forming apparatus capable of imparting the property can be obtained.

  According to the invention described in claim 8, it is excellent in storage stability and repetitive durability against rewriting with respect to media including a sheet mold, and is sufficient for light without being affected by the use environment temperature or the temperature in the apparatus. Thus, a device capable of forming and erasing a monochrome image capable of imparting a high degree of stability can be obtained.

  According to the ninth aspect of the present invention, the optical disk type medium is excellent in storage stability and repetitive durability against rewriting, and is sufficiently stable against light without being affected by the use environment temperature or the apparatus internal temperature. Thus, an apparatus capable of forming and erasing a monochrome image capable of imparting the property can be obtained.

  According to the invention described in claim 10, it is excellent in storage stability and repetitive durability against rewriting with respect to a medium including a sheet mold, and is sufficient for light without being affected by the use environment temperature or the apparatus internal temperature. A monochrome or multi-color image forming apparatus can be obtained which can impart a high degree of stability.

  According to the eleventh aspect of the present invention, the optical disc type medium is excellent in storage stability and repetitive durability against rewriting, and is sufficiently stable against light without being affected by the use environment temperature or the temperature in the apparatus. A monochrome image or a multicolor image forming apparatus capable of imparting the property can be obtained.

  According to the invention described in claim 12, it is excellent in storage stability and repetitive durability against rewriting with respect to a medium including a sheet mold, and is sufficient for light without being affected by the use environment temperature or the apparatus internal temperature. Thus, a device capable of forming and erasing a monochrome image or a multicolor image capable of imparting high stability can be obtained.

  According to the invention described in claim 13, the optical disk type medium is excellent in storage stability and repeated durability against rewriting, and is sufficiently stable against light without being affected by the use environment temperature or the temperature in the apparatus. Thus, an apparatus capable of forming and erasing a monochrome image or a multicolor image capable of imparting the property can be obtained.

  According to the fourteenth aspect of the present invention, an apparatus capable of erasing an image from a medium including a sheet mold can be obtained.

  According to the fifteenth aspect of the present invention, an apparatus capable of erasing an image from an optical disk type medium can be obtained.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated in order to avoid duplication of description.

  First, the basic mechanism of an image display medium in which a display layer containing a photochromic compound is formed on a substrate and a method of forming a color image by light irradiation on the display layer will be described.

FIG. 1 is a schematic diagram showing a configuration of an image display medium (1) used in the present invention.
In this image display medium (1), a display layer containing two or more types of photochromic compounds having different maximum absorption wavelengths in the colored state, that is, different colors recognized in the colored state, is formed on the support substrate (10). The The structure shown in FIG. 1 is formed by laminating display layers (11), (12), and (13) containing three types of photochromic compounds having different maximum absorption wavelengths. The display layer (11) containing the first photochromic compound has the characteristics of the maximum absorption wavelength shown in FIG. 2 (A), and the display layer (12) containing the second photochromic compound is shown in FIG. The display layer (13) having the maximum absorption wavelength characteristic indicated by ()) and including the third photochromic compound is composed of each having the maximum absorption wavelength characteristic indicated by (C) in FIG. In the image display medium of the present invention, the stacking order of the display layers (11), (12), and (13) is not necessarily the same as this example.

  In this, after coloring all kinds of photochromic compounds contained in the display layer by ultraviolet light irradiation, in the wavelength range corresponding to the visible absorption band of each colored photochromic compound (wavelength range near the maximum absorption wavelength) A desired color image is obtained by irradiating each predetermined region with light and selectively decoloring a corresponding photochromic compound. In the example shown in FIG. 1, the first display layer (11) is decolored with respect to light of wavelength A, and the second display layer (12) is decolored with respect to light of wavelength B. The third display layer (13) is decolored with respect to light of wavelength C.

  More specifically, the fact that the maximum absorption wavelength in the colored state is different means that the recognized color is different, and this maximum absorption wavelength only needs to be set according to the color to be used for display. In addition, the type of the photochromic compound may be set corresponding to the number of colors desired for display. By using photochromic compounds in which the hues in the colored state are yellow, magenta, and cyan, respectively, three primary colors for color display are formed.For example, by adjusting the degree of decoloration of each photochromic compound in the visible light irradiation step, It becomes possible to control the density of the color obtained by the photochromic compound, and the above-described image display method enables multicolor display with a wide color reproduction range.

  The above describes the case where an image is formed on an image display medium composed of a display layer containing two or more kinds of photochromic compounds having different maximum absorption wavelengths in a colored state. When an image display medium consisting of a display layer containing only one type of photochromic compound is targeted, a so-called monochrome image having a single color hue and a different density is formed. The basic method of forming an image by controlling the degree of color development of the photochromic compound contained is the same as in the case of forming a color image described above.

  In addition, even when the photochromic compound contained in the display layer is one type or when there are two or more types having different maximum absorption wavelengths in the colored state, the photochromic compound is in a predetermined region with respect to the state where all the photochromic compounds are decolored. A monochrome image can be formed by irradiating ultraviolet light to cause color development.

  The present invention can form a color image by light irradiation based on an image display medium having a display layer containing the photochromic compound described above formed on a substrate, and a method of forming an image by light irradiation on the display medium. In addition, the present invention was obtained as a result of studying an image display medium and an image forming method that are excellent in practical use so that an image can be rewritten and the formed image has sufficient stability to light.

Hereinafter, the present invention will be described in more detail.
One of the characteristics of the present invention is to constitute a photochromic composition containing a photochromic compound represented by the following general formula (I) and a compound having a long chain structure.

（ただし、Ｒ_１、Ｒ_２、Ｒ_３、Ｒ_４はアルキルであり、Ｒ_１、Ｒ_２の炭素数の合計、およびＲ_３、Ｒ_４の炭素数の合計がともに１２以上である。ＸおよびＹはそれぞれ独立して水素結合性基または会合性基を１つあるいは複数含む構造である。Ｚ_１、Ｚ_２は存在しないか、あるいは−ＣＨ_２ＯＣＯ−、−ＮＨＣＯ−、−Ｏ−、−ＯＣＯ−の中から選択される１つであり、Ｒ_５〜Ｒ_１６は独立して水素であるかまたは置換基である。）

(However, R ₁ , R ₂ , R ₃ , R ₄ are alkyl, and the total number of carbon atoms of R ₁ , R ₂ and the total number of carbon atoms of R ₃ , R ₄ are both 12 or more. X and Y is each independently a structure containing one or more hydrogen bonding groups or associative groups, Z ₁ and Z ₂ do not exist, or —CH ₂ OCO—, —NHCO—, —O—, — OCO- is one selected from RCO and R _{5 to} R ₁₆ are independently hydrogen or a substituent.)

  The spirooxazine photochromic compound represented by the general formula (I) changes its color from a spiro structure to a planar structure when irradiated with ultraviolet light, forms a stable aggregate upon heating, and disappears even when irradiated with visible light. Color will not occur.

  Compared to the conventionally well-known photochromic compounds, the photochromic compound of the general formula (I) shown here has a structure in which a hydrogen bonding group or an associative group is inserted in the middle of a long chain structure extending from the base skeleton. Thus, the interaction between long-chain structures between molecules in the associated state is strengthened, and the stability of the aggregate to heat is improved as compared with a compound having no hydrogen bonding property.

  Examples of the hydrogen bonding group or associative group in the long chain structure include an ester group, a carbonyl group, an amide group, an imide group, a urea group, a urethane group, and a diimide group.

In the general formula (I), R _{5 to} R ₁₆ are independently a substituent such as hydrogen or halogen, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a dialkylamino group, a cyano group, an amino group, or a nitro group.

In the general formula (I), Z ₁ and Z ₂ do not exist or are one selected from —CH ₂ OCO—, —NHCO—, —O—, —OCO—, and Z ₁ , Z _{When 2} does not exist, R ₁ and R ₃ are directly bonded to the photochromic compound.

  Regarding the length of the long chain structure of the general formula (I), that is, the total number of carbon atoms, when the long chain structure is generally shorter than 12, sufficient self-association is not exhibited. Also in this invention, when the number of carbon atoms as a whole of the long-chain structure compound is shorter than 12, sufficient self-association property is not expressed, and therefore, the association promoting effect is not expressed. is there.

  It has been confirmed as an experimental result that a long-chain alkyl compound improves the efficiency of association formation of a photochromic compound in a polymer medium.

  The long-chain alkyl structure preferably has 12 or more carbon atoms in order to control cohesion between molecules. For example, n-hexadecane, n-pentadecane, n-heptadecane, n-octadecane, n-nonadecane, n-eicosane, n-docosan and the like can be mentioned.

  In addition to the photochromic compound and long-chain alkyl compound, the material constituting the display layer includes a binder material, but it does not adversely affect the photochromic function of the photochromic compound and is compatible with the photochromic compound and long-chain alkyl compound. It is preferable to use a resin material that can be formed into a film and has excellent transparency after curing. Examples of such materials include polystyrene, polyester, polymethyl methacrylate, vinyl chloride-vinylidene chloride copolymer, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, and polyvinylphenol.

  With respect to each ratio when the photochromic composition in the present invention is constituted by the photochromic compound / long-chain alkyl compound / polymer represented by the general formula (I), the photochromic compound is 0.1 per 100 parts by weight of the polymer. It is desirable that the amount of the long-chain alkyl compound is 10 to 200 parts by weight.

  Another feature of the present invention is that an image display medium is formed by forming the above-described photochromic composition as a display layer on a support substrate.

  Materials for the supporting substrate include polyethylene terephthalate, polyethersulfone, polycarbonate, phenoxy resin, aromatic polyester, phenolic resin, epoxy resin, etc., or opaque materials formed by adding a white pigment thereto, and paper Materials can be used.

  The shape of the support substrate is not limited to a sheet shape, a card shape, or a film shape, and may be a block shape, for example, and the shape is not limited.

  Examples of the method for forming the display layer include a vapor deposition method in addition to the coating method, but the coating method is simple, and the photochromic compound, the long-chain structure compound, and the polymer material are both dissolved in a solvent, a printing method, The film may be applied by a method such as spin coating and dried to form a film. The display layer does not necessarily have to be formed on the entire support substrate, and may be formed on a part. The preferred thickness of the display layer varies depending on the concentration of the photochromic compound contained in the photochromic composition, but is preferably about 0.1 to 10 μm.

  Another feature of the present invention is that the display layer of the image display medium includes two or more photochromic compounds having different hues in an associated state.

  Another feature of the present invention is that an image is displayed by forming a display layer containing two or more photochromic compounds represented by the general formula (I) and a long-chain alkyl on the support substrate, which have different maximum absorption wavelengths in the associated state. That is, the medium is configured.

  As described above, by using two or more kinds of photochromic compounds represented by the general formula (I) having different maximum absorption wavelengths in the associated state, it is possible to display a plurality of colors having different hues.

  Another feature of the present invention is that the display layer includes all of a photochromic compound in which the hue in the association state is yellow, a photochromic compound in which the hue in the association state is magenta, and a photochromic compound in which the hue in the association state is cyan. Is to do.

  As a result, the three primary colors necessary for color display are formed, and a full color image can be formed by controlling and combining the respective photochromic compound erasing and decoloring states.

  As described above, the photochromic compound represented by the general formula (I) changes its color to a merocyanine structure when irradiated with ultraviolet light, forms a stable aggregate upon heating, and is decolored even when irradiated with visible light. Although it hardly occurs, the hue changes slightly because the absorption characteristics change before and after the aggregate formation. Considering this, it is necessary to set the photochromic compound by paying attention to the hue in the state in which the aggregate is formed.

  In the association state of the photochromic compounds, three primary colors of yellow, magenta, and cyan are configured, so that multicolor display is possible.

  As the photochromic compound represented by the general formula (I) in which the hue in the association state is yellow, for example, 3-((8′-bromo-5- (dimethylamino) -3,3-dimethyl-1- (2- (Pentadecanoyloxy) ethyl) spiro [indoline-2,3′-naphtho [2,1-b] [1,4] oxazin] -5′-yl) methoxy) -3-oxopropylpentadecanate or (8'-Bromo-5- (dimethylamino) -3,3-dimethyl-1- (2-pentadecanamidoethyl) spiro [indoline-2,3'-naphtho [2,1-b] [1,4] Oxazine] -5′-yl) methyl 3-pentadecanamide propanate.

  As the photochromic compound represented by the general formula (I) in which the hue in the association state indicates magenta, for example, 3-((8′-bromo-5-chloro-3,3-dimethyl-1- (2- (pentadeca Noyloxy) ethyl) spiro [indoline-2,3′-naphtho [2,1-b] [1,4] oxazin] -5′-yl) methoxy) -3-oxopropylpentadecanate or (8 ′ -Bromo-5,7-dichloro-3,3-dimethyl-1- (2-pentadecanamidoethyl) spiro [indoline-2,3'-naphtho [2,1-b] [1,4] oxazine] -5 '-Yl) methyl 3-pentadecanamide propanate.

  As the photochromic compound represented by the general formula (I) in which the hue in the associated state is cyan, for example, 3-((8′-bromo-3,3-dimethyl-1- (2- (pentadecanoyloxy) ethyl)) Spiro [indoline-2,3′-naphtho [2,1-b] [1,4] oxazin] -5′-yl) methoxy) -3-oxopropylpentadecanonate or (5,8′-dibromo -3,3-dimethyl-1- (2-pentadecanamidoethyl) spiro [indoline-2,3'-naphtho [2,1-b] [1,4] oxazin] -5'-yl) methyl 3-pentadecane Amidopropanate or (5,7,8′-tribromo-3,3-dimethyl-1- (2- (3-tridecylureido) ethyl) spiro [indoline-2,3′-naphtho [2,1 b] [1,4] oxazin] -5'-yl) and methyl 3- (3-tridecyl ureido) Puropaneto.

  Another feature of the present invention is that the display layer includes a first display layer containing a photochromic compound represented by the general formula (I) in which the hue in the associated state is yellow and a long-chain alkyl compound, and the hue in the associated state A second display layer containing a photochromic compound represented by the general formula (I) and methylene and a long chain alkyl compound, and a photochromic compound and a long chain alkyl represented by the general formula (I) in which the hue of the associated state is cyan The third display layer containing the compound has a laminated structure.

  An intermediate layer may be provided between each layer. In the process of laminating each layer, depending on the method of forming the laminated film, the constituent elements of each layer may be mixed around the boundary of each layer, so providing an intermediate layer prevents such mixing, resulting in each layer In this case, it becomes possible to form an appropriate aggregate. The material for forming the intermediate layer is transparent or has a certain degree of resistance to the organic solvent used in the coating method suitably used for forming the display layer, even if it is colored or small. Are preferable, and silicone resin, PVA (polyvinyl alcohol), and the like can be given. The forming method is the same as that of the display layer, and any method may be used, but the coating method is simple.

  Next, the above-described image display medium and an apparatus for forming and erasing an image of the above-described image display medium, for example, on a sheet-like printing body or a recording surface formed on a label recording surface of an optical disc will be described. First, a method for forming and erasing an image will be described.

(Method of forming a monochrome image)
A step of partially irradiating the above-described image display medium (whether one or more photochromic compounds are contained in the display layer) with ultraviolet light according to image data, and a step of raising the temperature to a predetermined temperature required for the association By applying the above, it becomes possible to form a monochrome image. Further, the image can be erased by performing a process of raising the temperature to a predetermined temperature necessary for erasure.

  First, a monochrome image is created by partially irradiating UV light based on the data corresponding to the image to be formed, with all the photochromic compounds contained in the display layer decolored as the initial state. Is formed.

  Next, by raising the temperature of the display layer to, for example, about 40 ° C., the photochromic compound contained in the display layer forms an aggregate, so that the monochrome image is stabilized and exposed to light such as illumination for a long time. The image will not fade or disappear. When the image is to be erased, the display layer is heated to a temperature of about 100 ° C., for example, and the association state of the photochromic compound contained in the display layer is solved and the color is erased to erase the image.

  As a method of partially irradiating ultraviolet light, a method of combining a lamp-shaped UV light source and an array-type or surface-type shutter, a method using a UV array light source capable of controlling irradiation ON / OFF by itself, or a UV laser Scan etc. are mentioned.

  As a means for raising the temperature to a predetermined temperature required for the meeting, conventional heaters such as a heat roller, a thermal head, a halogen heater, a ceramic heater, and a quartz tube heater can be used. In addition, the heating temperature and heating time of the photosensitive layer of the image display medium can be adjusted according to conditions such as the proximity distance to the image display medium and time, or the contact pressure and time. Therefore, they can also be used as means for raising the temperature to a predetermined temperature necessary for erasing.

(Method for forming a multicolor image)
A step of developing all the photochromic compounds contained in the display layer by irradiating the above-mentioned image display medium with ultraviolet light, and visible light in a wavelength region corresponding to the maximum absorption wavelength of each of the colored photochromic compounds. By applying a process of selectively erasing the photochromic compound by irradiation based on the image data and a process of raising the temperature to a predetermined temperature required for the association, the photochromic compound contained in the display layer is applied to one type of image display medium. On the other hand, a monochrome image is formed, and a multicolor image can be formed on an image display medium having two or more photochromic compounds contained in the display layer.

  First, all the photochromic compounds contained in the display layer are colored by irradiating the entire surface of the display layer with ultraviolet light. Next, by partially irradiating visible light in the wavelength region corresponding to the maximum absorption wavelength of each colored photochromic compound corresponding to the image to be formed, based on the image data, the photochromic compound is selectively decolored. A desired image is formed. Next, when the display layer is heated to a temperature of, for example, about 40 ° C., the photochromic compound contained in the display layer forms an aggregate and the image is stabilized. No longer fades or disappears. When it is desired to erase this image, for example, by raising the temperature of the display layer to a temperature of about 100 ° C., the association state of the photochromic compound contained in the display layer is solved and the color is erased to erase the image.

  As a method of irradiating the entire surface of the display layer with ultraviolet light, a mercury lamp or xenon lamp may be used in combination with an optical filter to extract ultraviolet light in a desired wavelength range, or in a specific wavelength range such as an LED or LD. A light-emitting element that emits light may be used.

  As a method of partially irradiating visible light, lamps having a configuration in which an optical filter is combined with a white light source may be used, or a light emitting element that emits light in a specific wavelength range such as an LED or LD may be used. Good. As a method of irradiating only a desired region, for example, a light source array is formed by relatively moving a light source array in which light emission surfaces capable of controlling on / off of irradiation for each minute region are continuously arranged, and an image display medium. This can also be achieved by controlling on / off of irradiation of each light emitting surface of the array.

  As a means for raising the temperature to a predetermined temperature required for the meeting, conventional heaters such as a heat roller, a thermal head, a halogen heater, a ceramic heater, and a quartz tube heater can be used. In addition, the heating temperature and heating time of the photosensitive layer of the image display medium can be adjusted according to conditions such as the proximity distance to the image display medium and time, or the contact pressure and time. Therefore, they can also be used as means for raising the temperature to a predetermined temperature necessary for erasing.

  Another feature of the present invention is that ultraviolet light irradiation means for partially irradiating the above-mentioned image display medium with ultraviolet light corresponding to the image data, and raising the display layer to a predetermined temperature necessary for image stabilization. It is to construct an apparatus having heating means for heating.

  The support substrate used for the image display medium in the present invention is not limited to a sheet shape, but may be any shape. Here, a configuration example and operation of a device capable of forming and erasing a monochrome image will be illustrated with a sheet-like image display medium as an example. 3 will be described.

  FIG. 3 is a schematic diagram illustrating an example of an image forming apparatus that forms a monochrome image on a sheet-like image display medium according to the first embodiment of the image forming apparatus of the present invention.

  A sheet-like image display medium (1) according to the present invention is set on a sheet mounting table (28) of an image forming apparatus (20). In the image display medium (1), a display layer containing the photochromic compound according to the present invention is provided on a substrate (10). The color of the substrate (10) is white, and the image display medium (1) is white when the photochromic compound is not colored.

  The image display medium (1) is conveyed from the insertion port (21) into the device (20) by the conveying roller (22). The ultraviolet light irradiating means (24) forms a monochrome image by partially irradiating ultraviolet light corresponding to the image to be formed to cause color development. This ultraviolet light irradiation means (24) is a method of combining a lamp-shaped UV light source and an array-type or surface-type shutter, a method using a UV array light source capable of controlling ON / OFF of irradiation by itself, a UV laser scan, etc. Consists of.

  The image display medium (1) on which the monochrome image is formed on the display layer by the ultraviolet light irradiation means (24) is further fed by the transport roller (22), and the predetermined temperature required for the association by the heating means (25). The temperature is increased to stabilize the image. As a means for raising the temperature to a predetermined temperature necessary for the meeting, a heat roller, a thermal head, a halogen heater, a ceramic heater, a quartz tube heater, or the like is used.

  The image display medium (1) for which the image stabilization processing has been completed by the heating means (25) is conveyed by the conveying roller (23), discharged from the discharge port (29), and placed on the discharge tray (27). Discharged.

  For example, it is possible to form a monochrome image by manufacturing the apparatus with such a configuration.

  Next, the optical disk label recording surface on which the display layer described above is provided, including an ultraviolet light irradiation means for partially irradiating ultraviolet light, and a heating means for raising the temperature to a predetermined temperature necessary for image stabilization, An apparatus for forming an image on an optical disk label recording surface will be described.

  In recent years, optical discs such as CDs and DVDs have become widespread as information recording media. Examples of the CD include a reproduction-only CD-ROM, a recordable CD-R, a rewritable CD-RW, and the like. As the DVD, a reproduction-only DVD-ROM, a recordable DVD-R, and a rewritable DVD. -RAM, DVD-RW, etc. For example, a recordable optical disc has an information recording layer. An optical disk having a label recording surface capable of recording characters and images by handwriting on a label recording surface opposite to the surface on the information recording layer is widely used.

  Once a character or image is recorded on the label recording surface by an ink jet printer or handwriting, the image or the like cannot be erased. In a rewritable optical disk, it is desirable that the label recording surface be rewritten correspondingly when the contents are rewritten. Therefore, if a recording layer made of the image display medium according to the present invention is provided on the label recording surface, image formation and erasure can be easily performed. Therefore, the present invention includes an ultraviolet light irradiation means for partially irradiating the optical disk label recording surface with ultraviolet light, and a heating means for raising the temperature to a predetermined temperature necessary for image stabilization. It is an object of the present invention to provide an apparatus capable of forming an image and erasing it if necessary.

  FIG. 4 is a schematic diagram showing an apparatus for forming an image on an optical disc label recording surface, showing a second embodiment of the image forming apparatus of the present invention. A configuration example of an apparatus for forming an image on an optical disk label recording surface and an outline of the operation will be described with reference to FIG.

  For example, an optical disk (100) is fixed and an apparatus capable of controlling rotation is used as a base, such as an existing optical disk drive apparatus. A label recording surface (100a) is provided on the surface opposite to the information recording surface of the optical disc (100). The label recording surface (100a) is provided with the above-described image recording medium according to the present invention. In this case, the optical disk substrate constitutes the base body (10).

  Then, a heating means (110) and an ultraviolet light irradiation means (111) are provided facing the label recording surface (100a).

  To record an image, first, the optical disk (100) is rotated in the direction of the arrow in the figure, and the ultraviolet light irradiating means (111) generates a color by partially irradiating ultraviolet light corresponding to the image to be formed. Form an image. Next, the heating means (110) raises the temperature to a predetermined temperature required for the meeting and stabilizes the image, whereby a monochrome image can be formed.

  The formation of an image on the optical disc label recording surface (100a) is basically performed as described above. In practice, however, the rotational speed of the optical disc, the irradiation timing of ultraviolet light corresponding to the radial direction of the disc, and the like. It is necessary to control according to the image data.

  Next, a configuration example of an apparatus in which the above-described optical disk drive apparatus is provided with the image recording apparatus of the present invention will be described with reference to the block diagram of FIG.

  An image recording apparatus capable of forming an image on a label recording surface without resetting the optical disc with respect to the optical disc (100) provided with the image recording medium of the present invention on the label recording surface (100a) of the optical disc. An optical disc device provided is provided.

  FIG. 5 is a block diagram showing a configuration of an optical disc apparatus provided with an image recording apparatus according to the second embodiment of the present invention.

  In FIG. 5, (120) is a drive mechanism section, (123) is a spindle motor, (124) is an optical pickup, (127) is a feed section, (111) is an ultraviolet light irradiation means, (125) is a heating means, ( 128) is a first analog processing unit, (129) is a servo processing unit, (130) is a motor driving unit, (131) is a controller, (132) is a laser driving unit, (133) is a digital signal processing unit, (134) ) Is a buffer memory, (137a) is an irradiation means driving unit, and (100) is an optical disk.

  The operation of the optical disc apparatus configured as described above according to an embodiment of the present invention will be described. In FIG. 5, the drive mechanism (120) includes a spindle motor (123) that rotates the optical disc (100), and an optical pickup (124) that records or reproduces information on the information recording surface of the optical disc (100). An optical light irradiation means (111) for forming a visible image by irradiating ultraviolet light onto the label recording surface (100a) of the optical disk, and a carriage on which the optical pickup (124) is mounted, the radius of the optical disk (100) It is composed of a feed part (127) for moving in the direction and a heating means (125) for raising the temperature to a predetermined temperature necessary for the meeting and stabilizing the image.

  The first analog signal processing unit (128) generates a focus error signal based on a signal output from an optical sensor (not shown) in the optical pickup (124) provided in the drive mechanism unit (120). A tracking error signal is generated and output to the servo processing unit (129).

  The servo processing unit (129) generates a lens position signal indicating the relative positional relationship between the objective lens of the optical pickup (124) and the carriage, and outputs the lens position signal to the first motor driving unit (130). The first motor drive unit (130) drives the optical pickup (124), the spindle motor (123), and the feed unit (127).

  The servo processing unit (129) includes an ON / OFF circuit, an arithmetic circuit, a filter circuit, an amplifier circuit, and the like, and the objective of the optical pickup (124) is set so that the light beam spot follows the information track of the optical disc (100). Focus / tracking control of the lens is performed, and further, feed control is performed so that the objective lens maintains a substantially neutral position by using a low frequency component of the tracking error signal.

  The feed unit (127) is composed of a feed motor, a gear, a screw shaft (not shown), and the like, and the carriage moves in the radial direction of the optical disc (100) by rotating the feed motor.

  The digital signal processing unit (133) converts the analog signal sent from the first analog signal processing unit (128) into a digital signal, and the controller (131), the laser driving unit (132), and the ultraviolet light irradiation means driving unit. (137), and sent to each part of the buffer memory (134).

  The controller (131) performs overall control of the servo unit configured as described above, and includes a first analog signal processing unit (128), a servo processing unit (129), a motor driving unit (130), a digital signal. The processing unit (133) receives signals sent from the respective units of the irradiation means driving unit (137), performs arithmetic processing of these signals, and sends out the results (signals) of the arithmetic processing to the respective units. Driving and processing to control each part.

  The motor drive unit (130) has an FG pulse signal having a frequency corresponding to the rotation speed of the spindle motor (123) in the digital signal processing unit (133) using the back electromotive current obtained from the spindle motor (123). Output to the PLL circuit.

  The PLL circuit multiplies the FG pulse signal and generates a PLL clock signal used for visible image formation. For example, when the spindle motor (123) generates n FG pulses while the optical disk rotates once, that is, when the optical disk rotates once, the PLL circuit generates a PLL clock signal obtained by multiplying the FG pulse.

  The digital signal processing unit (133) reads out data necessary for image formation indicating the gradation degree of one coordinate from the buffer memory (134) for each PLL clock signal, that is, every time the optical disk rotates by a certain angle. A lighting control signal is sent to the irradiation means driving unit (137).

  The ultraviolet light irradiation means (111) in this embodiment has a plurality of irradiation portions in a line shape in the radial direction of the optical disc (100). As the line-shaped ultraviolet light irradiation means (111), a combination of a lamp-shaped UV light source and an array-type shutter, or a UV array light source capable of controlling irradiation ON / OFF by itself is used. In the case of using a shutter, the irradiation driving means (137) controls the opening and closing of the shutter corresponding to the image data. When a UV array light source is used, the irradiation drive means (137) controls ON / OFF.

  By the way, as shown in the conceptual diagram of the recording track on the label recording surface in FIG. 6, the number of dots to be recorded on the optical disc (100) increases along the outer peripheral direction. When the linear ultraviolet light irradiation means (111) is used, the number of dots to be recorded is different between the inner peripheral side and the outer peripheral side. For this reason, the light emission part corresponding to the dot of the light irradiation means (111) of the inner peripheral side has fewer dots to be lit than the light emission part of the outer peripheral side. According to the example of FIG. 6, first, the dots corresponding to the L3 and L2 lines are turned on. At this time, the L1 line is not lit. Subsequently, when the optical disk (100) for one dot in the L3 line is rotated, the dots corresponding to the L3 line are turned on. At this time, the L1 and L2 lines are not lit. Subsequently, when the optical disk (100) for one dot of three lines is rotated, the dots corresponding to the L1, L2, and L3 lines are turned on. Further, when the optical disk (100) for one dot in the L3 line is rotated, the dots corresponding to the L2 and L3 lines are turned on. At this time, the L1 line is not lit.

  Thus, in this example, while the L3 line 4 dots are lit, the L2 line is controlled to be 3 dots and the L1 line is 1 dot, and the number of dots recorded on the inner and outer peripheral sides is different. Controlled to record.

  Next, an image recording operation on the label recording surface of the optical disc (100) will be described. When the optical disc (100) is inserted, the optical disc apparatus rotates the spindle motor (123), starts the activation process, applies focus servo and tracking servo, and disc discriminates.

  Next, a visible image recording operation on the label recording surface (100a) is performed according to a user instruction. In the image recording operation on the label recording surface (100a), the disk rotation speed is first set.

  For setting the rotation speed of the optical disc (100), various user input information is transmitted from the host device to the controller (131) via the digital signal processing unit (133), and the controller (131) is based on the information. An instruction is given to the motor drive unit (130) via the servo processing unit (129) to operate the spindle motor (123). Further, the controller (131) transmits information to the ultraviolet light irradiation means (111) via the ultraviolet light irradiation driving means (137), and starts the lighting control operation of the ultraviolet light irradiation means (111).

  Next, the controller (131) detects each recording position linear velocity from the operation status of the spindle motor (123). The recording position linear velocity detection is calculated from the radial position of each irradiation part of the ultraviolet light irradiation means (111) and the rotation speed of the spindle motor (123).

  Subsequently, an image recording operation on the label recording surface (100a) of the optical disc (100) is started. In the image recording operation on the label recording surface (100a) of the optical disc (100), the controller (131) first gives an instruction to the digital signal processing unit (133) based on the information already received from the user. It is transmitted in the order of the ultraviolet light irradiation means (111) via the ultraviolet light irradiation driving means (137), and the desired irradiation part of the ultraviolet light irradiation means (111) is turned on.

  By rotating the optical disc (100) once, an image is recorded on the label recording surface (100a) of the optical disc (100). Here, when the output of the recording power of the ultraviolet light irradiation means (111) is limited, the optical disk (100) is rotated several times in order to perform multiple recording at the same location for multiple recording operations. What is necessary is just to comprise so that it may superimpose and record in a location.

  Then, after an image is recorded on the label recording surface (100a) of the optical disc (100), an operation for stabilizing the image is started. To stabilize the image, the heating means (110) is heated to a predetermined temperature required for the meeting, the spindle motor (123) is driven, the optical disk (100) is rotated, and the heating means (110) is passed under the heating means (110). . When the temperature is raised to a predetermined temperature required for the meeting by passing once, the rotation of the optical disk (100) may be one degree, but according to the power of the heating means (110), the optical disk (100 ) Is rotated and stabilized.

  Next, a third embodiment of the present invention will be described. In the third embodiment, as shown in FIG. 7, an ultraviolet light irradiation means (24) for partially irradiating the above-mentioned image display medium with ultraviolet light, and a display layer at a predetermined temperature necessary for image stabilization. And a first heating means (25a) for raising the temperature of the display layer to a predetermined temperature necessary for erasing the formed image.

  FIG. 7 is a schematic diagram illustrating an example of an image forming apparatus for forming and erasing a monochrome image on a sheet-like image display medium according to the third embodiment of the present invention.

  A sheet-like image display medium (1) according to the present invention is set on a sheet mounting table (28) of an image forming apparatus (20). In the image display medium (1), a display layer containing the photochromic compound according to the present invention is provided on a substrate (10). The color of the substrate (10) is white, and the image display medium (1) is white when the photochromic compound is not colored.

  The image display medium (1) is conveyed from the insertion port (21) into the device (20) by the conveying roller (22). If necessary, the first heating means (25a) erases the image by raising the temperature of the display layer to a predetermined temperature necessary for erasing the image. Then, the ultraviolet light irradiation means (24) forms a monochrome image by irradiating the ultraviolet light partially in correspondence with the image to be formed to cause color development.

  The image display medium (1) on which the monochrome image is formed on the display layer by the ultraviolet light irradiation means (24) is further fed by the transport roller (22), and is necessary for the meeting by the second heating means (25b). The image is stabilized by raising the temperature to a predetermined temperature.

  The image display medium (1) for which the image stabilization processing has been completed by the second heating means (25b) is conveyed by the conveying roller (23), discharged from the discharge port (29), and discharged from the discharge tray (27). ) Discharged on top.

  For example, it is possible to form and erase a monochrome image by manufacturing the apparatus with such a configuration.

  In the configuration example described above, the first heating means (25a) for erasing and the second heating means (25b) for stabilizing the image are provided separately. However, only one heating means is used for the erasing process and the stabilizing process. They may be used by heating them to the necessary temperatures. In that case, the image display medium (1) is transferred to the heating means again after the erasing process by the heating means and the image forming process by the ultraviolet light irradiation means (24) while being conveyed, and the stabilization process is performed. However, various configurations are conceivable.

  Next, a fourth embodiment of the present invention will be described. In this embodiment, as shown in FIG. 8, the optical disk label recording surface (100a) on which the display layer is formed is irradiated with ultraviolet light irradiation means (111) that partially irradiates ultraviolet light, and image stabilization. A second heating means (125b) for raising the display layer to a predetermined temperature required for the image and a first heating means (125a) for raising the display layer to a predetermined temperature required for erasing the formed image Is to build.

  An example of the configuration of the apparatus is the same as that shown in FIGS. 4 and 5, the second heating means (125b) for raising the display layer to a predetermined temperature necessary for image stabilization, and the display layer at a predetermined temperature necessary for erasing the formed image. A first heating means (125a) for raising the temperature of

  4 and 5, the same heating means may be used properly by heating to the respective temperatures required for the erasing process and the stabilizing process. In this case, for example, if necessary, the display layer is first heated to a predetermined temperature necessary for erasing the image, and the rotation of the disk is controlled to erase the image. Next, a monochrome image is formed by irradiating the ultraviolet light partially with the ultraviolet light irradiation means in correspondence with the image to be formed to cause color development. Next, the temperature is raised to a predetermined temperature required for the association by the heating means and the image is stabilized, whereby a monochrome image can be formed and erased.

  Next, a fifth embodiment of the present invention will be described. In this embodiment, as shown in FIG. 9, the image display medium (1) is irradiated with ultraviolet light irradiation means (24) for irradiating the display layer with ultraviolet light, and the maximum absorption of each photochromic compound in the colored state. A visible light irradiating means (26) for irradiating visible light in a wavelength region corresponding to the wavelength, and a heating means (25) for raising the display layer to a predetermined temperature necessary for image stabilization are provided.

  A configuration example and operation of the fifth embodiment will be described with reference to FIG.

  A sheet-like image display medium (1) according to the present invention is set on a sheet mounting table (28) of an image forming apparatus (20). In the image display medium (1), a display layer containing the photochromic compound according to the present invention is provided on a substrate (10). The color of the substrate (10) is white, and the image display medium (1) is white when the photochromic compound is not colored.

  The image display medium (1) is conveyed from the insertion port (21) into the device (20) by the conveying roller (22). If necessary, the temperature of the display layer is raised to a predetermined temperature necessary for erasing the image by the heating means (25) to erase the image. Then, all photochromic compounds contained in the display layer are colored by the ultraviolet light irradiation means (24).

  The colored image display medium (1) is sent to the visible light irradiation means (26) by the transport roller (22). The visible light irradiation means (26) partially irradiates visible light in a wavelength region corresponding to the maximum absorption wavelength of each colored photochromic compound corresponding to the image to be formed, as shown in FIG. Selectively decolorize photochromic compounds. By selectively erasing, a desired image is formed.

  Next, the heating means (25) raises the display layer to a predetermined temperature necessary for the association to stabilize the image, and the image is discharged out of the apparatus from the discharge port (29). For example, it is possible to form a monochrome image or a multicolor image by manufacturing the apparatus with such a configuration.

  Next, a sixth embodiment of the present invention will be described. In the present embodiment, as shown in FIG. 10, an ultraviolet light irradiation means (111) for irradiating the display layer with ultraviolet light on the optical disc label recording surface (100a) on which the display layer is formed, A visible light irradiating means (126) for irradiating visible light in a wavelength range corresponding to the maximum absorption wavelength of the photochromic compound, and a heating means (110) for raising the display layer to a predetermined temperature necessary for image stabilization. Composed.

  A configuration example and operation of the apparatus according to the sixth embodiment will be described with reference to FIG.

  For example, an optical disk (100) is fixed and an apparatus capable of controlling rotation is used as a base, such as an existing optical disk drive apparatus. A label recording surface (100a) is provided on the surface opposite to the information recording surface of the optical disc (100). The label recording surface (100a) is provided with the above-described image recording medium according to the present invention. The image recording medium (1) is configured to be capable of color display. As shown in FIG. 1, the image display medium 1 is configured in the same manner as having the first, second, and third photosensitive layers (11), (12), and (13). The first photosensitive layer (11) includes the above-described fulgide compound having a maximum absorption wavelength in the range of 400 nm to less than 500 nm, and the second photosensitive layer (12) has a maximum absorption wavelength of 500 nm to less than 600 nm. The layer containing the fulgide compound and the third photosensitive layer (13) in the above range are composed of a layer containing the fulgide compound in which the maximum absorption wavelength is in the range of 400 nm to less than 500 nm. The photosensitive layer thus formed is colorless and the color of the substrate (10) is white. This image display medium (1) is recognized as white by the observer.

  Then, a heating means (110), an ultraviolet light irradiation means (111), and a visible light irradiation means (126) are provided facing the label recording surface (100a). The visible light irradiation means (126) is configured to irradiate three types of visible light corresponding to the respective maximum absorption wavelengths in order to perform color display. For example, it is composed of three types of light emitting diode arrays. For example, the first light emitting diode array is irradiated with visible light having a center wavelength of 460 nm and a half width of 10 nm, and the second light emitting diode array is irradiated with visible light having a center wavelength of 560 nm and a half width of 10 nm. As such, it may be configured such that visible light having a center wavelength of 660 nm and a half width of 10 nm can be irradiated. By irradiating the above three types of light emitting diode arrays based on the corresponding image data, the display layer having the absorption wavelength in the irradiated visible light is selectively decolored and a color image is displayed.

  First, when the optical disk (100) is rotated in the direction of the arrow in the figure and the ultraviolet light irradiating means (111) partially irradiates ultraviolet light corresponding to the image to be formed to cause color development, all three display layers are formed. Color develops to black. Next, the visible light irradiation means (126) selectively irradiates the photochromic compound by partially irradiating visible light in a wavelength region corresponding to the maximum absorption wavelength of each photochromic compound colored corresponding to the image to be formed. A desired image is formed by decoloring.

  Thereafter, the heating means (110) raises the temperature to a predetermined temperature required for the meeting and stabilizes the image, whereby a monochrome image or a multicolor image can be formed.

  Next, a sixth embodiment in which the above-described apparatus is applied to an optical disk drive apparatus will be described with reference to the block diagram of FIG. Although the basic configuration is the same as that shown in FIG. 5, the image shown in FIG. 5 was recorded by the irradiation of the ultraviolet light irradiation means (111). Image recording based on the image data is performed by the light irradiation means (126). The same components as those in FIG. 5 are denoted by the same reference numerals, and description thereof is omitted here in order to avoid duplication of description.

  FIG. 11 is a block diagram showing a configuration of an optical disc apparatus provided with an image recording apparatus according to the sixth embodiment of the present invention.

  In FIG. 11, (120) is a drive mechanism section, (123) is a spindle motor, (124) is an optical pickup, (127) is a feed section, (111a) is an ultraviolet light irradiation means, and (126) is a visible light irradiation means. , (125) is a heating means, (128) is a first analog processing unit, (129) is a servo processing unit, (130) is a motor driving unit, (131) is a controller, (132) is a laser driving unit, (133) ) Is a digital signal processing unit, (134) is a buffer memory, (137a) is a visible light driving unit, and (100) is an optical disk.

  In the embodiment shown in FIG. 5, image data is recorded by the ultraviolet light irradiation means. For this reason, it is configured to be able to be turned on / off corresponding to the pixel dot. On the other hand, in the embodiment shown in FIG. 11, the ultraviolet light irradiation means (111a) may color the entire image display medium (1) regardless of the pixel dots. For this reason, what is necessary is just to be able to irradiate the radial direction of the optical disc (100) in a line shape with a mercury lamp or the like. In this embodiment, the light irradiation based on the image data is performed by the visible light irradiation means (126). For this reason, as described above, the visible light irradiation means (126) is configured to be able to irradiate three types of visible light corresponding to the respective maximum absorption wavelengths in order to perform color display. Yes. In this embodiment, the first light-emitting diode array can emit visible light with a center wavelength of 460 nm and a half-value width of 10 nm, and the second light-emitting diode array emits visible light with a center wavelength of 560 nm and a half-value width of 10 nm. As a light-emitting diode array, a light-emitting diode array capable of irradiating visible light with a center wavelength of 660 nm and a half-value width of 10 nm is prepared, and the three light-emitting diode arrays constitute the visible light irradiation means (126). The visible light irradiating means (126) performs lighting control of each dot of the light emitting diode array corresponding to the image data by a driving signal given from the visible light driving unit (137a).

  Next, an image recording operation on the label recording surface of the optical disc (100) will be described. When the optical disc (100) is inserted, the optical disc apparatus rotates the spindle motor (123), starts the activation process, applies focus servo and tracking servo, and disc discriminates.

  Next, a visible image recording operation on the label recording surface (100a) is performed according to a user instruction. In the image recording operation on the label recording surface (100a), the disk rotation speed is first set.

  For setting the rotation speed of the optical disc (100), various user input information is transmitted from the host device to the controller (131) via the digital signal processing unit (133), and the controller (131) is based on the information. An instruction is issued to the first motor drive unit (130) via the servo processing unit (129) to operate the spindle motor (123). The controller (131) transmits information to the ultraviolet light irradiation means (111a) and the visible light irradiation means (126), and starts the lighting control operation of the ultraviolet light irradiation means (111a) and the visible light irradiation means (126). .

  Next, the controller (131) detects each recording position linear velocity from the operation status of the spindle motor (123). The recording position linear velocity detection is calculated from the radial position of each irradiation section of the visible light irradiation means (126) and the rotation speed of the spindle motor (123).

  Subsequently, an image recording operation on the label recording surface (100a) of the optical disc (100) is started. In the image recording operation on the label recording surface (100a) of the optical disc (100), the label recording surface (100a) is first irradiated with ultraviolet rays by the ultraviolet light irradiation means (11a). All three display layers are colored and become black by the ultraviolet irradiation. When the ultraviolet light irradiation means (111a) detects that the optical disk (100) has rotated once in the ultraviolet light irradiation means (111a), the irradiation stops. By controlling in this way, it is possible to prevent the color erased by the visible light irradiation means (126) from recurring.

  Based on the information already received from the user, the controller (131) first issues an instruction to the digital signal processing unit (133), which passes through the visible light driving unit (137a), and the visible light irradiation means ( 126), and a desired light emitting diode of the visible light irradiation means (126) is turned on, whereby the display layer having an absorption wavelength in the irradiated visible light is selectively decolored, and a color image or a monochrome image is formed. Is displayed.

  By rotating the optical disc (100) once, an image is recorded on the label recording surface (100a) of the optical disc (100). Here, when the output of the recording power of the visible light irradiating means (126) is limited, the optical disk (100) is rotated several times in order to perform the overlapping recording in which the recording operation is performed a plurality of times at the same location. What is necessary is just to comprise so that it may overlap and record in a location.

  Then, after an image is recorded on the label recording surface (100a) of the optical disc (100), an operation for stabilizing the image is started. In order to stabilize the image, the heating means (125) is heated to a predetermined temperature required for the meeting, the spindle motor (123) is driven, the optical disk (100) is rotated, and the heating means (125) is passed under. . When the temperature is raised to a predetermined temperature required for the meeting by passing once, the rotation of the optical disk (1) may be one degree, but according to the power of the heating means (125), the optical disk (100 ) Is rotated and stabilized. The heating means (125) uses a ceramic heater and is configured such that the temperature is controlled by the conveyance speed of the image display medium so that the display layer of the image display medium can be heated to 80 ° C. and 45 ° C., respectively. .

  Next, as shown in FIG. 12, in the seventh embodiment of the present invention, the above-mentioned image display medium is irradiated with ultraviolet light irradiation means (24) for irradiating the display layer with ultraviolet light, A visible light irradiation means (26) for irradiating visible light in a wavelength range corresponding to the maximum absorption wavelength of the photochromic compound, a second heating means (25b) for raising the display layer to a predetermined temperature required for image stabilization, and A first heating means (25a) for raising the temperature of the display layer to a predetermined temperature necessary for erasing the formed image is provided.

  FIG. 12 is a schematic diagram illustrating an example of an image forming apparatus that forms a multicolor image or forms a monochrome image and erases a sheet-like image display medium according to a seventh embodiment of the present invention.

  A sheet-like image display medium (1) according to the present invention is set on a sheet mounting table (28) of an image forming apparatus (20). The image display medium (1) is provided by laminating three display layers containing the photochromic compound according to the present invention on a substrate (10). The color of the substrate (10) is white, and the image display medium (1) is white when the photochromic compound is not colored.

  The image display medium (1) is conveyed from the insertion port (21) into the device (20) by the conveying roller (22). If necessary, the first heating means (25a) erases the image by raising the temperature of the display layer to a predetermined temperature necessary for erasing the image. Then, the ultraviolet light irradiating means (24) irradiates the ultraviolet light so that all the photochromic compounds contained in the display layer are colored.

  The visible light irradiation means (26) partially irradiates visible light in a wavelength region corresponding to the maximum absorption wavelength of each colored photochromic compound to selectively erase the photochromic compound, thereby obtaining a desired image. Form.

  The image display medium (1) on which the image is formed on the display layer is further fed by the transport roller (22), and the second heating means (25b) raises the temperature to a predetermined temperature necessary for the meeting and the image is displayed. Stabilized.

  The image display medium (1) for which the image stabilization processing has been completed by the second heating means (25b) is conveyed by the conveying roller (23), discharged from the discharge port (29), and discharged from the discharge tray (27). ) Discharged on top.

  For example, by manufacturing the apparatus with such a configuration, it is possible to form and erase a color image or a monochrome image.

  In the configuration example described above, the first heating means (25a) for erasing and the second heating means (25b) for stabilizing the image are provided separately. However, only one heating means is used for the erasing process and the stabilizing process. They may be used by heating them to the necessary temperatures. In that case, the image display medium (1) is transferred to the heating means again after the erasing process by the heating means and the image forming process by the ultraviolet light irradiation means (24) while being conveyed, and the stabilization process is performed. However, various configurations are conceivable.

  Next, an eighth embodiment of the present invention will be described. In this embodiment, as shown in FIG. 13, the optical disc label recording surface (100a) on which the display layer is formed is irradiated with ultraviolet light irradiation means (111) for irradiating the display layer with ultraviolet light, and in a colored state. Visible light irradiation means (126) for irradiating visible light in a wavelength region corresponding to the maximum absorption wavelength of each photochromic compound, and second heating means (125b) for raising the display layer to a predetermined temperature necessary for image stabilization And constructing an apparatus including first heating means (125a) for raising the temperature of the display layer to a predetermined temperature necessary for erasing the formed image.

  An example of the configuration of the apparatus is the same as that shown in FIGS. 10 and 11, the second heating means (125b) for raising the display layer to a predetermined temperature necessary for image stabilization, and the display layer at a predetermined temperature necessary for erasing the formed image. A first heating means (125a) for raising the temperature of

  As an example of the configuration of the apparatus, the same configuration as that shown in FIG. 12 may be used so that the same heating means is heated to the respective temperatures required for the erasing step and the stabilizing step. In this case, for example, if necessary, the display layer is first heated to a predetermined temperature necessary for erasing the image, and the rotation of the optical disc (100) is controlled to erase the image. Next, all the photochromic compounds contained in the display layer are colored by the ultraviolet light irradiation means (111), and then each photochromic compound colored by the visible light irradiation means (126) corresponding to the image to be formed. A desired image is formed by partially irradiating the photochromic compound by partially irradiating visible light in a wavelength region corresponding to the maximum absorption wavelength. Next, it is possible to form a monochrome image or a multi-color image by stabilizing the image by raising the temperature to a predetermined temperature required for the association by the heating means.

  About a heating means, as shown in FIG. 13, it is good also as a structure which provides the heating means for exclusive use for an erasing process and a stabilization process one by one.

  As shown in FIG. 14, the ninth embodiment of the present invention includes a heating means (25) for raising the temperature of the display layer to a predetermined temperature necessary for erasing the formed image with respect to the image display medium described above. It constitutes the device.

  A configuration example and operation of the apparatus will be described with reference to FIG.

  When the image display medium (1) is conveyed from the insertion opening (21) into the apparatus by the conveying roller (22), the display layer is heated to a predetermined temperature necessary for erasing the image by the heating means (25). Is erased and discharged out of the apparatus through the outlet (29). As another configuration example, as shown in FIG. 15, a plurality of image display media (1) subjected to the erasing process may be stored in the apparatus and taken out of the apparatus as necessary.

  In the tenth embodiment of the present invention, as shown in FIG. 16, the display layer is placed at a predetermined temperature required for erasing the formed image on the optical disc label recording surface (100a) on which the display layer is formed. The apparatus comprises a heating means (110) for raising the temperature.

  A configuration example and operation of the apparatus will be described with reference to FIG. A device that can fix the optical disk (100) and can control the rotation like the existing optical disk drive is used as a base, and the heating means (110) is provided. The disk (100) from which the image is to be erased is set in the apparatus, and the temperature of the display layer is raised to a predetermined temperature necessary for erasing the image by the heating means (110), and the rotation of the disk is controlled to erase the image.

  Alternatively, erasing can be performed using an apparatus having the same configuration as that shown in FIGS. 14 and 15 and having no disk rotation mechanism.

  Hereinafter, the present invention will be specifically described based on examples.

Example 1
As a photochromic compound, 3-((8′-bromo-3,3-dimethyl-1- (2- (pentadecanoyloxy) ethyl) spiro [indoline-2,3′-naphtho [2,1-b] [1 , 4] oxazin] -5′-yl) methoxy) -3-oxopropylpentadecanonate (hereinafter referred to as “PC1”), n-docosane as the long-chain alkyl compound, and polymethacryl as the binder. Methyl acid was used. 20 parts by weight of n-docosane was added to 20 parts by weight of PC1, and 80 parts by weight of polymethyl methacrylate was added. Using toluene as a solvent, a coating solution was prepared to produce a cast film on a quartz substrate.

  When the absorption spectrum before light irradiation was measured, the absorption band was recognized in the range of 300-400 nm, and it was colorless.

  When this was irradiated with 366 nm ultraviolet light extracted from a high-pressure mercury lamp, it developed blue and the maximum absorption wavelength of the absorption spectrum was 598 nm. When this was heat-processed at 40 degreeC with the heat roller, the hue changed to cyan and the maximum absorption wavelength of the absorption spectrum was 625 nm.

  When this was again heat-treated again at 100 ° C. with a heat roller, it returned to colorless and no absorption was observed in the visible region.

  A cast film having the same formulation as described above was formed on a white PET (polyethylene terephthalate) substrate (thickness: 188 μm), and a PVA film (thickness: 2 μm) was further formed as a protective layer to produce an image display medium. Since the display layer formed in this way is colorless and the color of the substrate is white, the produced image display medium was recognized as white by the observer.

Next, after irradiating the display layer of the image display medium with 366 nm ultraviolet light again to saturate the color reaction, the heat treatment is performed at 40 ° C. with a heat roller, and then visible light having a center wavelength of 620 nm and a half width of 10 nm is emitted. Irradiation was performed for 24 hours at an illuminance of 1 mW / cm ² , but the display layer did not change and was not decolored. Thereafter, it was stored in a thermostat set at 80 ° C. for 24 hours, but the display layer did not change and was not decolored. When the heat treatment was temporarily performed at 100 ° C. by the heat roller, the display layer returned to colorless.

  In addition, this image display medium was irradiated with 366 nm ultraviolet light to cause color development, heat treated with a heat roller to 40 ° C. and associated, and then decolored with a 100 ° C. heat roller 100 times. It did not occur and good repeated durability was confirmed.

(Example 2)
The image display medium produced in Example 1 was formed using the apparatus shown in FIG. The image display medium (1) is transported from the insertion port (21) into the device (20) by the transport roller (22), and is heat-treated at 100 ° C. by the heat roller (first heating means) (25a) to erase the image. To do. Next, when the display layer was irradiated with an ultraviolet LED (ultraviolet light irradiation means) (24), the display layer was colored blue-violet. Next, heat treatment was performed at 40 ° C. by a heat roller (second heating means) (25b), and the image display medium colored cyan was discharged from the discharge port (29). This image display medium was irradiated with a fluorescent lamp at an illuminance of 700 lx for 24 hours, but the display layer did not change and was not erased. Thereafter, it was stored in a thermostat set at 80 ° C. for 24 hours, but the display layer did not change and was not decolored. When the heat treatment was temporarily performed at 100 ° C. by the heat roller (25a), the display layer returned to colorless.

(Example 3)
As a photochromic compound, (5,8′-dibromo-3,3-dimethyl-1- (2-pentadecanamidoethyl) spiro [indoline-2,3′-naphtho [2,1-b] [1,4] oxazine ] -5′-yl) methyl 3-pentadecanamide propanate (hereinafter referred to as “PC2”) was used, n-eicosane was used as the long-chain alkyl compound, and polymethyl methacrylate was used as the binder. 20 parts by weight of n-eicosane and 80 parts by weight of polymethyl methacrylate were added to 20 parts by weight of PC2. Using toluene as a solvent, a coating solution was prepared to produce a cast film on a quartz substrate.

  When the absorption spectrum before light irradiation was measured, the absorption band was recognized in the range of 300-400 nm, and it was colorless.

  When this was irradiated with 366 nm ultraviolet light extracted from a high-pressure mercury lamp, it developed blue and the maximum absorption wavelength of the absorption spectrum was 620 nm. When this was heat-treated at 40 ° C. with a heat roller, the hue changed to cyan, and the maximum absorption wavelength of the absorption spectrum was 636 nm.

  When this was again heat-treated again at 100 ° C. with a heat roller, it returned to colorless and no absorption was observed in the visible region.

  Next, a cast film having the same formulation as above was formed on a white PET (polyethylene terephthalate) substrate (thickness: 188 μm), and a PVA film (thickness: 2 μm) was further formed as a protective layer to produce an image display medium. . Since the display layer formed in this way is colorless and the color of the substrate is white, the produced image display medium was recognized as white by the observer.

Next, after irradiating the display layer of this image display medium with 366 nm ultraviolet light again to saturate the color reaction, it is heated to 40 ° C. with a heat roller, and then visible light having a center wavelength of 640 nm and a half width of 10 nm is applied. Irradiation was performed for 24 hours at an illuminance of 1 mW / cm ² , but the display layer did not change and was not erased. Thereafter, it was stored in a thermostat set at 80 ° C. for 24 hours, but the display layer did not change and was not decolored. When the heat treatment was temporarily performed at 100 ° C. by the heat roller, the display layer returned to colorless.

  In addition, this image display medium was irradiated with 366 nm ultraviolet light to cause color development, heat treated with a heat roller to 40 ° C. and associated, and then decolored with a 100 ° C. heat roller 100 times. It did not occur and good repeated durability was confirmed.

Example 4
A cast film having the same formulation as in Example 3 was formed on the optical disc 100, and a PVA film (film thickness: 2 μm) was further formed as a protective layer to produce an image display medium. Since the display layer formed in this way is colorless and the color of the substrate is white, the produced image display medium was recognized as white by the observer.

  Next, an image was formed on the optical disk (100) using the apparatus shown in FIG. When an ultraviolet LED (ultraviolet light irradiation means) (111) equipped with a liquid crystal shutter was arbitrarily irradiated, the portion irradiated with the ultraviolet light was colored blue-violet. When heat treatment was carried out at 40 ° C. with a ceramic heater (heating means) (125b), the portion that was colored blue exhibited cyan. The optical disk (100) was irradiated with a fluorescent lamp at an illuminance of 700 lx for 24 hours, but the display layer did not change and was not erased. Thereafter, it was stored in a thermostat set at 80 ° C. for 24 hours, but the display layer did not change and was not decolored. When the heat treatment was temporarily performed at 100 ° C. by the ceramic heater (125a), the display layer returned to colorless.

(Example 5)
As a photochromic compound, 3-((8′-bromo-5-chloro-3,3-dimethyl-1- (2- (pentadecanoyloxy) ethyl) spiro [indoline-2,3′-naphtho [2,1 -B] [1,4] oxazin] -5′-yl) methoxy) -3-oxopropylpentadecanate (hereinafter referred to as “PC3”), n-eicosane was used as the long-chain alkyl compound, Polystyrene was used as a binder. 20 parts by weight of n-eicosane and 80 parts by weight of polystyrene were added to 20 parts by weight of PC3. A coating solution was prepared using toluene as a solvent to prepare a cast film on a quartz substrate. When the absorption spectrum before light irradiation was measured, the absorption band was recognized in the range of 300 nm-400 nm, and it was colorless.

  When this was irradiated with 366 nm ultraviolet light extracted from a high-pressure mercury lamp, it developed blue-violet and the maximum absorption wavelength of the absorption spectrum was 570 nm.

  When this was heat-treated at 40 ° C. with a heat roller, the hue changed to magenta, and the maximum absorption wavelength of the absorption spectrum was 532 nm. When this was again heat-treated again at 100 ° C. with a heat roller, it returned to colorless and no absorption was observed in the visible region.

  20 parts by weight of n-eicosane and 80 parts by weight of polystyrene were added to 20 parts by weight of PC3. A coating solution is prepared using toluene as a solvent, a cast film is formed on a white PET (polyethylene terephthalate) substrate (thickness: 188 μm), and 20 weight parts of n-eicosane is added to 20 parts by weight of PC2. Then, 80 parts by weight of polystyrene was added, and a cast film was formed from a coating solution using toluene as a solvent to prepare an image display medium. Since the display layer formed in this way is colorless and the color of the substrate is white, the produced image display medium was recognized as white by the observer.

  When the display layer of this image display medium was irradiated with 366 nm ultraviolet light, both PC2 and PC3 developed color and exhibited a bluish green color. Further, when this was irradiated with white light, the display layer became colorless and transparent again, so that the image display medium was recognized as white.

  This image display medium was again irradiated with 366 nm ultraviolet light to develop a color, and then a part thereof was irradiated with visible light having a center wavelength of 620 nm and a half-value width of 10 nm. Exhibited a bluish purple color. Further, when another portion was irradiated with visible light having a center wavelength of 570 nm and a half-value width of 10 nm, PC3 was selectively decolored and the irradiated portion exhibited blue. Further, when this was irradiated with white light, the display layer became colorless and transparent again, so that the image display medium was recognized as white.

  This image display medium was again irradiated with 366 nm ultraviolet light to develop a color, and then a part thereof was irradiated with visible light having a center wavelength of 620 nm and a half-value width of 10 nm. Exhibited a bluish purple color. Further, when another portion was irradiated with visible light having a center wavelength of 570 nm and a half-value width of 10 nm, PC3 was selectively decolored and the irradiated portion exhibited blue. After that, when the heat treatment was carried out to 40 ° C. with a heat roller, the portion showing blue-purple became magenta, and the portion showing blue showed cyan. This image display medium was stored in a thermostat set at 80 ° C. for 24 hours, but the display layer did not change and was not decolored.

(Example 6)
The image display medium used in Example 5 was formed using the apparatus shown in FIG. The image display medium (1) is transported from the insertion port (21) into the device (20) by the transport roller (22), and is heat-treated at 100 ° C. by the heat roller (first heating means) (25a) to erase the image. To do.

  Next, when the display layer was irradiated with an ultraviolet light LED (ultraviolet light irradiation means) (24), the display layer was colored blue-green.

  Next, an arbitrary image was formed by an LED (visible light irradiation means) (26) having a central wavelength of 630 nm and a half-value width of 10 nm and an LED (visible light irradiation means) (26) having a half-value width of 10 nm and a liquid crystal shutter. Subsequently, heat treatment was performed at 40 ° C. by the heat roller (second heating means) (25b), and the image display medium (1) displaying an arbitrary image was discharged from the discharge port (29). This image display medium was irradiated with a fluorescent lamp at an illuminance of 700 lx for 24 hours, but the display layer did not change and was not erased. This image display medium was stored in a thermostat set at 80 ° C. for 24 hours, but the display layer did not change and was not decolored.

(Example 7)
As a photochromic compound, 3-((8′-bromo-5- (dimethylamino) -3,3-dimethyl-1- (2- (pentadecanoyloxy) ethyl) spiro [indoline-2,3′-naphtho [ 2,1-b] [1,4] oxazin] -5′-yl) methoxy) -3-oxopropylpentadecanate (hereinafter referred to as “PC4”), and n- Docosan was used and polystyrene was used as the binder. 20 parts by weight of n-docosane was added to 20 parts by weight of PC4, and 80 parts by weight of polystyrene was added. A coating solution was prepared using toluene as a solvent to prepare a cast film on a quartz substrate.

  When the absorption spectrum before light irradiation was measured, the absorption band was recognized in the range of 300 nm-400 nm, and it was colorless.

  When this was irradiated with 366 nm ultraviolet light extracted from a high-pressure mercury lamp, it developed red and the maximum absorption wavelength of the absorption spectrum was 498 nm. When this was heat-treated at 40 ° C. with a heat roller, the hue changed to yellow and the maximum absorption wavelength of the absorption spectrum was 466 nm. When this was again heat-treated again at 100 ° C. with a heat roller, it returned to colorless and no absorption was observed in the visible region.

  In addition, this image display medium was irradiated with 366 nm ultraviolet light to cause color development, heat treated with a heat roller to 40 ° C. and associated, and then decolored with a 100 ° C. heat roller 100 times. It did not occur and good repeated durability was confirmed.

  20 parts by weight of n-docosane was added to 20 parts by weight of PC4, and 80 parts by weight of polystyrene was added. A coating solution is prepared using toluene as a solvent, a cast film is formed on a white PET (polyethylene terephthalate) substrate (thickness: 188 μm), and 20 parts by weight of PC3 is formed on the PVA intermediate layer. On the other hand, 20 parts by weight of n-docosane was added and 80 parts by weight of polystyrene was added. A cast film is formed from a coating solution using toluene as a solvent, and 20 parts by weight of n-docosane is added to 20 parts by weight of PC2 through an intermediate layer of PVA, and 80 parts of polystyrene is added. An image display medium was prepared by adding parts by weight, forming a cast film by a coating solution using toluene as a solvent, and further forming a PVA film as a protective layer. Since the display layer formed in this way is colorless and the color of the substrate is white, the produced image display medium was recognized as white by the observer.

  When the display layer of this image display medium was irradiated with 366 nm ultraviolet light, all of PC2, PC3, and PC4 were colored and black. Further, when this was irradiated with white light, the display layer became colorless and transparent again, so that the image display medium was recognized as white.

  This image display medium was again irradiated with 366 nm ultraviolet light to develop color, and then a part thereof was irradiated with visible light having a central wavelength of 500 nm and a half-value width of 10 nm. Exhibited a bluish green color. Further, when another part was irradiated with visible light having a center wavelength of 570 nm and a half-value width of 10 nm, PC3 was selectively decolored, and the irradiated part exhibited a bluish purple color. Moreover, when another part was irradiated with visible light having a center wavelength of 620 nm and a half-value width of 10 nm, PC2 was selectively decolored, and the irradiated part was reddish purple. Further, when this was irradiated with white light, the display layer became colorless and transparent again, so that the image display medium was recognized as white.

  This image display medium was again irradiated with 366 nm ultraviolet light to develop color, and then a part thereof was irradiated with visible light having a central wavelength of 500 nm and a half-value width of 10 nm. Exhibited a bluish green color. Further, when another part was irradiated with visible light having a center wavelength of 570 nm and a half-value width of 10 nm, PC3 was selectively decolored, and the irradiated part exhibited a bluish purple color. Moreover, when another part was irradiated with visible light having a center wavelength of 620 nm and a half-value width of 10 nm, PC2 was selectively decolored, and the irradiated part was reddish purple. After that, when the heat treatment was performed at 40 ° C. with a heat roller, the portion that had been blue-green turned blue, the portion that had been bluish-purple became green, and the portion that had had red-purple color was red. Even when this image display medium was irradiated with white light (100,000 lux) for 24 hours, there was no change in the image display medium. Further, this image display medium was stored in a thermostat set at 80 ° C. for 24 hours, but the display layer was not changed and was not decolored.

(Example 8)
A display layer was also produced on the optical disc (100) in the same procedure as in Example 7. An image was formed on the optical disk (100) using the apparatus shown in FIG. First, when the display layer was irradiated with an ultraviolet LED (ultraviolet light irradiation means) (111), the display layer was colored black. An arbitrary image was formed by an LED having a liquid crystal shutter having a center wavelength of 620 nm and a half-value width of 10 nm and an LED having a half-value width of 10 nm and an LED (visible light irradiation means) (126) having a center wavelength of 500 nm and a half-value width of 10 nm. A ceramic heater (heating means) (125b) was heated to 40 ° C. to fix the image.

  The optical disk (100) was irradiated with a fluorescent lamp at an illuminance of 700 lx for 24 hours, but the display layer did not change and was not erased. Thereafter, it was stored in a thermostat set at 80 ° C. for 24 hours, but the display layer did not change and was not decolored. When the heat treatment was temporarily performed at 100 ° C. by the ceramic heater (125a), the display layer returned to colorless.

(Comparative Example 1)
As a photochromic compound, 8′-bromo-1,3-dihydro-3,3-dimethyl-1-octadecyl-5′-docosanoyloxymethylspiro [2H-indole-2,3 ′-[3H] naphtho [2,1-b] ] [1,4] oxazine] (hereinafter referred to as “PC5”), n-docosane was used as the long-chain alkyl compound, and polymethyl methacrylate was used as the binder. 20 parts by weight of n-docosane and 80 parts by weight of polymethyl methacrylate were added to 20 parts of PC5. Using toluene as a solvent, a coating solution was prepared to produce a cast film on a quartz substrate.

  When the absorption spectrum before light irradiation was measured, the absorption band was recognized in the range of 300-400 nm, and it was colorless.

  When this was irradiated with 366 nm ultraviolet light extracted from a high pressure mercury lamp, it developed blue-violet and the maximum absorption wavelength of the absorption spectrum was 575 nm. When this was heat-processed at 40 degreeC with the heat roller, the hue changed and the maximum absorption wavelength of the absorption spectrum was 538 nm.

  When this was again heat-treated again at 100 ° C. with a heat roller, it returned to colorless and no absorption was observed in the visible region.

  Next, a cast film having the same formulation as above was formed on a white PET (polyethylene terephthalate) substrate (thickness: 188 μm), and a PVA film (thickness: 2 μm) was further formed as a protective layer to produce an image display medium. . Since the display layer formed in this way is colorless and the color of the substrate is white, the produced image display medium was recognized as white by the observer.

Next, after irradiating the display layer of the image display medium with 366 nm ultraviolet light again to saturate the color reaction, heat treatment is performed at 40 ° C. with a heat roller, and then visible light having a center wavelength of 540 nm and a half width of 10 nm is emitted. Irradiation was performed for 24 hours at an illuminance of 1 mW / cm ² , but the display layer did not change and was not erased. Then, when it stored for 24 hours in the thermostat set to 80 degreeC, the display layer returned to colorless.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention can be used for so-called electronic paper, CD, DVD label surfaces, and the like.

It is a schematic diagram which shows the structure of the image display medium used for this invention. It is a schematic diagram which shows the relationship between the light absorbency of a photochromic compound, and a wavelength. 1 is a schematic diagram illustrating an image forming apparatus according to a first embodiment of the present invention, which forms a monochrome image on a sheet-like image display medium. FIG. FIG. 5 is a schematic diagram illustrating an apparatus for forming an image on an optical disc label recording surface according to a second embodiment of the image forming apparatus of the present invention. FIG. 5 is a block diagram illustrating an image forming apparatus according to a second embodiment of the present invention, in which the image recording apparatus of the present invention is provided in an optical disk drive device. It is a conceptual diagram of the recording track of a label recording surface. FIG. 10 is a schematic diagram illustrating an image forming apparatus that forms and erases a monochrome image on a sheet-like image display medium according to a third embodiment of the present invention. FIG. 9 is a schematic diagram illustrating an apparatus for forming an image on an optical disc label recording surface according to a fourth embodiment of the image forming apparatus of the present invention. FIG. 9 is a schematic diagram illustrating an image forming apparatus that performs monochrome image formation and erasure on a sheet-like image display medium according to a fifth embodiment of the present invention. FIG. 10 is a schematic diagram illustrating an apparatus for forming an image on an optical disc label recording surface according to a sixth embodiment of the image forming apparatus of the present invention. FIG. 10 is a block diagram illustrating an image forming apparatus according to a sixth embodiment of the present invention, in which the image recording apparatus of the present invention is provided in an optical disk drive device. FIG. 10 is a schematic diagram illustrating an image forming apparatus according to a seventh embodiment of the present invention, which performs multicolor image formation or monochrome image formation and erasure on a sheet-like image display medium. FIG. 10 is a schematic diagram illustrating an image forming apparatus according to an eighth embodiment of the present invention, which forms an image on an optical disc label recording surface. 1 is a schematic diagram showing an image erasing apparatus of the present invention. 1 is a schematic diagram showing an image erasing apparatus of the present invention. 1 is a schematic diagram showing an image erasing apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image display medium 10 Support base | substrate 11 Display layer 12 Display layer 13 Display layer 20 Device 21 Insertion port 22 Conveyance roller 23 Conveyance roller 24 Ultraviolet light irradiation means 25 Heating means 25a First heating means 25b Second heating means 26 Visible light irradiation means 27 Discharge tray 28 Sheet placement table 29 Discharge port 100 Optical disc 100a Optical disc label recording surface 110 Heating means 111 Ultraviolet light irradiation means 111a Ultraviolet light irradiation means 120 Drive mechanism 123 Spindle motor 124 Optical pickup 125 Heating means 125a First heating means 125b Second heating unit 126 Visible light irradiation unit 127 Feed unit 128 First analog processing unit 129 Servo processing unit 130 Motor drive unit 131 Controller 132 Laser drive unit 133 Digital signal processing unit 134 Buffer memory 137 Irradiation unit drive Part 137a visible light driver

Claims (15)

Containing a photochromic compound represented by the following general formula (I) and a long-chain alkyl compound comprising n-hexadecane, n-pentadecane, n-heptadecane, n-octadecane, n-nonadecane, n-eicosane or n-docosane. A photochromic composition characterized.

(However, R ₁ and R ₃ are alkylene groups, R ₂ and R ₄ are alkyls, and the total number of carbon atoms of R ₁ and R ₂ and the total number of carbon atoms of R ₃ and R ₄ are both 12 or more. X and Y are each independently an ester group, a carbonyl group, an amide group, an imide group, a urea group, a urethane group, or a diimide group , Z ₁ and Z ₂ are not present, or —CH ₂ OCO—, -NHCO-, -O-, -OCO-, wherein R _{5 to} R ₁₆ are independently hydrogen, halogen, alkyl group, alkoxy group, alkoxycarbonyl group, dialkylamino group, cyano Group, amino group, or nitro group .) An image display medium, wherein a display layer made of the photochromic composition according to claim 1 is formed on a support substrate. The image display medium according to claim 2, wherein the display layer contains two or more kinds of photochromic compounds having different hues in an associated state. The display layer includes a first photochromic compound exhibiting a yellow hue in an association state, a second photochromic compound exhibiting a magenta hue, and a third photochromic compound exhibiting a cyan hue. Item 4. The image display medium according to Item 3. The display layer has a structure in which a display layer containing only a first photochromic compound, a display layer containing only a second photochromic compound, and a display layer containing only a third photochromic compound are laminated. The image display medium according to claim 4. An ultraviolet light irradiation means for partially irradiating the image display medium according to any one of claims 2 to 5 with ultraviolet light, and a heating means for raising the temperature of the display layer to a predetermined temperature necessary for image stabilization. An image forming apparatus comprising the image forming apparatus. 6. Rotation driving means for rotationally driving an optical disc having an optical disc label recording surface including a portion of the image display medium according to claim 2, and ultraviolet light for partially irradiating the optical disc label recording surface with ultraviolet light. An image forming apparatus comprising: irradiation means; and heating means for raising a temperature to a predetermined temperature necessary for image stabilization. An ultraviolet light irradiation means for partially irradiating ultraviolet light to the image display medium according to any one of claims 2 to 5, and a heating means for raising the temperature of the display layer to a predetermined temperature necessary for image stabilization; An image forming apparatus comprising: heating means for raising the temperature of the display layer to a predetermined temperature necessary for erasing the formed image. A rotation driving means for rotating and driving an optical disc having an optical disc label recording surface including a portion of the image display medium according to any one of claims 2 to 5, and ultraviolet light is partially irradiated to the display layer of the optical disc label recording surface. An ultraviolet light irradiation means for heating, a heating means for raising the temperature of the display layer to a predetermined temperature necessary for image stabilization, and a heating means for raising the temperature of the display layer to a predetermined temperature necessary for erasing the formed image. An image forming apparatus. 6. An ultraviolet light irradiation means for irradiating the display layer with ultraviolet light on the image display medium according to claim 2, and visible light in a wavelength range corresponding to a maximum absorption wavelength of each photochromic compound in a colored state. An image forming apparatus comprising: a visible light irradiating unit that irradiates the display layer; and a heating unit that raises the temperature of the display layer to a predetermined temperature necessary for image stabilization. 6. Rotation driving means for rotationally driving an optical disc having an optical disc label recording surface including the image display medium portion according to claim 2, and ultraviolet light for irradiating the display layer of the optical disc label recording surface with ultraviolet light. Irradiation means, visible light irradiation means for irradiating visible light in a wavelength region corresponding to the maximum absorption wavelength of each photochromic compound in a colored state, and heating means for raising the temperature of the display layer to a predetermined temperature necessary for image stabilization An image forming apparatus comprising: 6. An ultraviolet light irradiation means for irradiating the display layer with ultraviolet light on the image display medium according to claim 2, and visible light in a wavelength range corresponding to a maximum absorption wavelength of each photochromic compound in a colored state. Visible light irradiating means, heating means for raising the display layer to a predetermined temperature necessary for image stabilization, and heating means for raising the display layer to a predetermined temperature necessary for erasing the formed image. An image forming apparatus comprising the image forming apparatus. 6. Rotation driving means for rotationally driving an optical disc having an optical disc label recording surface including the image display medium portion according to claim 2, and ultraviolet light for irradiating the display layer of the optical disc label recording surface with ultraviolet light. Irradiation means, visible light irradiation means for irradiating visible light in a wavelength region corresponding to the maximum absorption wavelength of each photochromic compound in a colored state, and heating means for raising the temperature of the display layer to a predetermined temperature necessary for image stabilization An image forming apparatus comprising: heating means for raising the temperature of the display layer to a predetermined temperature necessary for erasing the formed image. 6. An image erasing apparatus comprising: heating means for raising a temperature of a display layer to a predetermined temperature necessary for erasing a formed image with respect to the image display medium according to claim 2. A heating means for raising the temperature of the display layer to a predetermined temperature necessary for erasing the formed image is provided on the optical disc label recording surface including the image display medium portion according to any one of claims 2 to 5. An image erasing device.

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