JP2006248137A - Image display medium and method for manufacturing image display medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display medium which takes an effective visual effect to make a light diffraction structure appear as if it were painted in a desired color. <P>SOLUTION: This image display medium 1 comprises a light diffraction structure part 21 constituted of a halftone dot-like light diffraction structure, formed in a colored region 20 on a base material 10. In addition, the halftone dot area ratio of a halftone dot 21a constituting the light diffraction structure part 21 to the colored region 20, is 15 to 60%. Further, the area of each halftone dot 21a is less than 0.25 mm<SP>2</SP>and diffuse-formed by an error diffusion process. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image display body including an optical diffraction structure and a method for manufacturing an image display body including an optical diffraction structure.

  A transfer foil having a light diffraction structure forming layer on which a light diffraction structure that is a fine relief structure such as a hologram or a diffraction grating is formed is used for the purpose of improving high designability and security. And the method of coloring a light diffraction structure is also known in order to improve design nature and security nature further. For example, as a colored layer transfer material for obtaining an effect that looks like a colored light diffraction structure (hereinafter sometimes referred to as “colored hologram”), a metal that is colored with a fine relief structure and a unique color There are known those having a reflective layer composed of (see, for example, Patent Documents 1 and 2). Further, the present applicant also discloses a layer structure in which a light diffraction structure forming layer and a reflective layer are laminated and a colored layer is added to the observation side from the reflective layer in order to obtain an effect that looks like a colored hologram. (For example, see Patent Documents 3 to 4).

  In addition, as a colored layer transfer material that can be transferred onto a transfer target and can obtain a colored metallic gloss color, a colored layer and a metal layer (reflective layer) having a colored layer and a metallic sensation are known. (See, for example, Patent Documents 5 to 7). However, since such a colored layer transfer material is not provided with a fine uneven relief structure that exhibits a light diffraction effect such as a hologram or a diffraction grating, a specific design or optical effect cannot be obtained.

  On the other hand, by transferring the light diffractive structure onto a substrate having a predetermined image in the form of a halftone dot, a light diffractive structure composed of the halftone dot light diffractive structure is formed, and the decorative effect by the diffracted light is imaged Also known is a method of adding to (see, for example, Patent Documents 8 to 10).

JP 09-160475 A JP 08-328456 A Japanese Patent Laid-Open No. 61-238079 JP-A-62-17784 JP 63-30288 A Japanese Unexamined Patent Publication No. 63-230389 Japanese Patent Laid-Open No. 09-11638 Japanese Patent Laid-Open No. 08-123299 JP-A-11-227368 Japanese Patent Application Laid-Open No. 2004-101834

  However, the above-described method of forming the reflective layer with a metal having a specific color uses a metal alloy having a specific color, so it is extremely difficult to stably deposit the desired compounding ratio of the metal alloy stably. is there. In addition, it takes a lot of time to change to a predetermined metal alloy material at the time of vapor deposition, there is a risk of contamination (contamination with materials used before and after), and there is a disadvantage that it is extremely disadvantageous in terms of cost. is there.

  Further, in the method of additionally providing a colored layer, the colored layer transfer material is basically one color, and the light diffraction structure cannot be colored into a plurality of desired colors. For example, it is difficult to color a plurality of portions of the light diffraction structure in different colors such as gold, sapphire, emerald, and ruby. Therefore, there is no colored layer transfer material that is low in cost, has good manufacturability and good color tone preservation, and has a light diffraction effect due to the light diffraction structure.

  Furthermore, in the conventional method of transferring a light diffractive structure to a halftone dot, the visual synergistic effect obtained by the diffracted light of the light diffractive structure and the color of the region located under the light diffractive structure is almost taken into consideration. It has not been. Therefore, the colored region may be almost covered by the transferred light diffraction structure. Even when the above-mentioned synergistic effect is taken into consideration, in the conventional method, the brightness of the light diffraction structure portion due to the diffracted light may be unnatural.

  Therefore, an object of the present invention is to provide an image display body that has a more effective visual effect that the light diffraction structure appears to be colored in a desired color.

  The present invention solves the above-described problems by the following method. In order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are appended in parentheses, but the present invention is not limited to the illustrated embodiment.

The image display body (1) of the present invention is an image display body in which a light-diffractive structure part (21) composed of a dot-like light diffraction structure is provided in a colored region (20) on a base material (10). The halftone dot area ratio of the halftone dots (21a) constituting the light diffraction structure portion to the colored region is 15% to 60%, and each halftone dot has an error of less than 0.25 mm ^2. The above-mentioned problem is solved by being provided by being diffused by a diffusion method.

  By providing the halftone dots constituting the light diffraction structure portion on the colored region in a state of being diffused by the error diffusion method with the above halftone dot area and halftone dot area ratio, the natural brightness due to the diffracted light is uniform in the colored region. The inventor has found that it can be added to. According to the present invention, a uniform brightness can be given to the colored region, so that the colored region in which the light diffraction structure portion of the present invention is formed can be used like a colored light diffraction structure.

  In the present invention, the light diffraction structure includes a diffraction grating having a certain uneven pattern and a hologram on which interference fringes for generating a predetermined hologram image are formed. In addition, the error diffusion method includes a random dither method, a Floyd & Steinberg type, a Jarvis, Judice & Ninke type, and any of them may be used. Any method may be used for printing the colored region. The colored region of the image display body of the present invention may be colored with a single color. Thereby, the colored area | region in which the light diffraction structure part was formed can be utilized as a monochromatic light diffraction structure colored in the color of the colored area.

The method for producing an image display body (1) of the present invention uses a transfer sheet (60) in which a light diffraction structure forming layer (63) on which a light diffraction structure is formed is laminated on a substrate sheet (61). The method of manufacturing an image display body, wherein the light diffraction structure portion (21) is formed by transferring the light diffraction structure formation layer in a halftone dot pattern onto the colored region (20) on the transfer target (1 ′). Then, each halftone dot (21a) constituting the light diffraction structure portion has an area of less than 0.25 mm ² and an error diffusion method so that the halftone dot area ratio with respect to the colored region is 15% to 60%. The above-mentioned problem is solved by being transferred to the colored region in a state of being diffused by.

  By this manufacturing method, the image display body of the present invention can be obtained. The interpretation of the light diffraction structure and the error diffusion method is as described above.

  The optical diffraction structure forming layer is thermally transferred from the transfer sheet to the colored region using a thermal head, and the halftone dot of the area is based on the printing energy applied to the thermal head. The image may be transferred while being diffused by the error diffusion method at a rate. As a result, the printing energy of the thermal head can be optimized based on the light diffraction structure and the material of the transfer target, and each halftone dot is transferred based on the optimized printing energy, resulting in a more natural glow. Can be obtained.

  Further, the colored region of the transfer object may be colored with a single color. Thereby, the colored area | region in which the light diffraction structure part was formed by this invention can be utilized as a monochromatic light diffraction structure colored in the color of the colored area.

As described above, according to the present invention, a halftone dot light diffraction structure is formed in the colored region, the area of each halftone dot is less than 0.25 mm ² , and the halftone dot area ratio is 15% to 60%. It is possible to provide an image display body and an image display body manufacturing method that have a more effective visual effect that the light diffraction structure appears to be colored in a desired color by being provided in a diffused state. it can.

  FIG. 1 is a diagram showing an example of an image display body 1 of the present invention. The image display body 1 has a plurality of colored portions 20, 30, 40 on the substrate 10. The colored portions 20, 30, and 40 are colored with different colors. The entire colored portion 20 is provided with a light diffraction structure as a light diffraction structure portion 21 in a dot pattern. For this reason, in addition to coloring, the colored part 20 is in a state where a visual effect by diffracted light is given. Hereinafter, the colored portion 20 in a state where the light diffraction structure portion 21 is provided is referred to as a colored hologram portion 22. In this embodiment, the colored portions 20, 30, and 40 are colored by sublimation printing, but the printing method for coloring the colored portions 20, 30, and 40 is not limited.

  In this embodiment, a diffraction grating is used as the light diffraction structure constituting the light diffraction structure 21. The light diffraction structure includes a diffraction grating and a hologram, and is strictly distinguished from a diffraction grating composed of a certain uneven pattern and a hologram composed of interference fringes that generate a predetermined hologram image. Hereinafter, the hologram is used in the same meaning as the light diffraction structure. The material which respectively comprises the base material 10 and the coloring part 20 may be suitably determined by the use application of the image display body 1. FIG. The hologram of the light diffraction structure 21 is not limited as long as it is a diffraction grating that can be formed as a hologram forming layer on a hologram transfer sheet described later.

As shown in FIG. 2, the colored hologram portion 22 of the image display body 1 is formed by laminating a colored portion 20 made of ink on a base material 10, and a light diffraction structure portion 21 on one surface of the colored portion 20. A plurality of halftone dots 21a to 21a are provided. In less than an area of 0.25 mm ² each halftone dot 21a, the state dot percent for colored hologram portion 22 of the halftone dot 21a is 15% to 60%, each halftone dot 21a is diffused by the error diffusion method, That is, the halftone dots having a certain shape are not regularly arranged at regular intervals, and the nonuniform halftone dots are provided in a nonuniform state.

  Since the plurality of halftone dots 21a... 21a constituting the light diffraction structure 21 are provided in the colored portion 20 under the above conditions, the colored hologram portion 22 has a natural brightness due to diffracted light on one side, and the colored portion. It looks like a hologram colored with 20 colors. For example, when the colored portion 20 is colored red, it looks like a hologram colored red. 3, 4, and 5 show a plurality of halftone dots 21 a provided in the colored portion 20 at a halftone dot area ratio of 15%, 35%, and 60%, respectively. In each figure, the whited portion is the portion where the halftone dot 21a is provided.

  Next, the manufacturing method of the image display body 1 is demonstrated. In this embodiment, the image display body 1 is manufactured by the image manufacturing apparatus 50 shown in FIG. The image manufacturing apparatus 50 includes an input unit 51 that receives various setting operations of the user, a display unit 52 that displays images and various messages according to the settings of the user, and a hologram transfer unit 53 that transfers a hologram. , A storage unit 54 that stores various symbols and various information provided on the substrate 10, a transferred object supply unit 55 that supplies the transferred object, a discharge unit 56 that discharges the manufactured image display 1, and And a control unit 57 that controls the operation of each of the components 51.

  The hologram transfer unit 53 of this embodiment prints a hologram by a thermal transfer method using the hologram transfer sheet 60 shown in FIG. On the hologram transfer sheet 60, a release layer 62, a hologram forming layer 63 on which a hologram is formed, a reflection layer 64, and an adhesive layer 65 are laminated on one side of the base sheet 61, and on the other side of the base sheet 61. A heat resistant layer 66 is provided. The hologram transfer sheet 60 of this embodiment is a transfer foil in which a diffraction grating is formed as a hologram of the hologram forming layer 63.

  By adhering the adhesive layer 65 to the transfer target and pressing the thermal head from the heat resistant layer 66 side, the base material sheet 61 side and the hologram forming layer 63 side are peeled off at the part of the peeling layer 62, and the hologram forming layer 63. Is transferred onto the transfer medium. The material constituting each layer 61... 66 may be a conventionally known material.

  In addition, by providing the reflective layer 64 on the relief surface of the hologram forming layer 63, the relief diffraction effect can be enhanced. The reflective layer 64 is preferably made of a metal having a high light reflectance. The higher the reflectance of the metal constituting the reflective layer 64, the brighter the diffracted light can be obtained. Specifically, a metal such as Cr, Ni, Ag, Au, and Al, and thin films such as oxides, sulfides, and nitrides thereof may be used alone or in combination. The light-reflective metal thin film desirably has a thickness of about 10 to 2000 nm, preferably 20 to 1000 nm so that a sufficient reflection effect can be obtained.

  In this embodiment, an image display body 1 ′ shown in FIG. 7 is used as a transfer target. The image display body 1 ′ is provided with a plurality of colored portions 20, 30, and 40 on the base material 10. The colored portions 20, 30, and 40 are colored by a sublimation method, but may be colored by another printing method. In the transferred object supply section 55, a plurality of variations colored with different colors for the colored sections 20, 30, and 40 are prepared.

  The overall flow of the process for manufacturing the image display body 1 by the image manufacturing apparatus 50 will be described with reference to the flowchart shown in FIG. Each process in the flowchart of FIG. 9 is performed by the control unit 57 according to a predetermined program. First, a symbol selection process is performed (step S70). In the symbol selection process, the user is made to select a desired colored symbol provided on the base material 10. For example, a plurality of selectable colored symbols are displayed on the display unit 52, and a user's selection operation is accepted by the input unit 51.

  An image display body 1 ′ corresponding to the user's selection operation in the symbol selection process is displayed on the display unit 52. At this time, the size and position of the coloring portions 20, 30, and 40 may be appropriately changed by a user input operation. When the symbol selection process is completed, the user is caused to specify a region where the hologram is to be transferred on the image display body 1 ′ (step S72). In this embodiment, the user is allowed to select a design for transferring the hologram on the image display 1 ′. Hereinafter, the case where the coloring part 20 of the image display body 1 ′ is selected will be described. When the coloring unit 20 is specified as a region to which the hologram is transferred, a hologram transfer process is performed (step S74). In the hologram transfer process, the light diffraction structure portion 21 is formed in the coloring portion 20, and the image display body 1 is manufactured. Specific processing of the hologram transfer processing will be described later. Finally, the manufactured image display body 1 is discharged from the discharge unit 56 (step S76), and the process related to the manufacture of the image display body 1 is completed.

  The hologram transfer process will be specifically described with reference to the flowchart shown in FIG. When the coloring unit 20 is specified as a region to which the hologram is transferred, gray information is read from the storage unit 54 (step S80). The gray information is a ratio of an area occupied by the hologram to a predetermined region, for example, one dot when transferring the hologram, and is set as a value of printing energy given to the thermal head. Optimal values are preset and stored in the storage unit 54 according to the hologram of the hologram forming layer 63, the material constituting the image display body 1 ′, and the use application of the image display body 1.

Next, diffusion processing is performed based on the gray information (step S82). In the diffusion processing, the position and size of the halftone dots 21a provided as the light diffraction structure portion 21 on the coloring portion 20 are determined so as to satisfy a predetermined condition based on the gray information. Hereinafter, information regarding the halftone dot 21a determined by the diffusion process is referred to as halftone dot information. The predetermined conditions are a halftone dot area, a halftone dot area ratio with respect to the colored portion 20, and processing by an error diffusion method. In this embodiment, the area of the halftone dot 21a is 0.04 mm ² , the halftone dot area ratio is 30%, and it is arranged in a state of being diffused by a random dither method which is one of error diffusion methods. The halftone dot information of each halftone dot 21a is calculated.

The area of the halftone dots 21a may be less than 0.25 mm ² and the halftone dot area ratio may be in the range of 15% to 60%. The error diffusion method is not limited to the random dither method, and any method may be used. As the area and the dot area ratio, appropriate values are set in advance according to the intended use of the image display body 1.

  A method for obtaining halftone dot information using gray information will be described with reference to FIG. As described above, the gray information is a ratio of an area that the hologram can occupy with respect to the predetermined region. For example, conceptually showing the case of 35% gray information for the colored portion 20, as in the state A before diffusion processing, the white region 90 to which the hologram is transferred occupies 35% of the entire colored portion 20, and the hologram is transferred. The remaining black area 91 is the remaining 65%. The white area 90 to which the hologram is transferred is diffused into nonuniform halftone dots by the error diffusion method so as to satisfy the above conditions, and halftone dot information of each halftone dot 21a is calculated. A state B after diffusion processing in FIG. 11 shows a state where the colored portion 20 is rectangular and diffused in a state where the dot area ratio is 35%.

  Returning to FIG. 10, when halftone dot information is obtained by the diffusion process, the operation of the thermal head is controlled based on the halftone dot information, and the hologram forming layer 63 from the hologram transfer sheet 60 is colored by the above-described aged portion. Thermal transfer is carried out in the form of halftone dots on 20 (step S84). Thereby, the light diffraction structure part 21 can be provided on the coloring part 20.

  The present invention is not limited to the form described above, and may be implemented in various forms. The image display body 1 may have at least one colored portion, and the entire image display body 1 may be colored. In addition, the colors of the plurality of colored portions may be different or the same. Further, the shape of the colored portion 20 of the image display body 1 is not limited to a star shape.

  In the image manufacturing apparatus 50, a plurality of types of holograms that can be transferred may be prepared and a user may select a desired hologram. In this case, the optimum gray information for each hologram may be set in advance in association with the hologram. Further, the area to which the hologram is transferred may be determined in advance. In the image manufacturing apparatus 50, a printing unit for coloring the base material 10 may be provided.

  In the hologram transfer sheet 60, the release layer 62 and the adhesive layer 65 do not need to be provided when other layers have sufficient peelability and adhesiveness. Other layers may be provided.

The figure which shows an example of the image display body of this invention. Sectional drawing along the VV line of FIG. The enlarged view of the coloring hologram part formed with the dot area rate of 15%. The enlarged view of the coloring hologram part formed with the dot area ratio of 35%. The enlarged view of the coloring hologram part formed with the halftone dot area rate of 60%. The figure which shows the image manufacturing apparatus of this form. Sectional drawing of the hologram transfer sheet used with the image manufacturing apparatus of FIG. The figure which shows the coloring part provided in the base material. The flowchart which shows the flow of the process which manufactures an image display body. The flowchart which shows the flow of a hologram transfer process. The figure which shows how halftone dot information is obtained from gray information.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image display body 10 Base material 20, 30, 40 Coloring part 21 Optical diffraction structure part 21a Halftone dot

Claims (5)

In the colored region on the substrate, an image display body provided with a light diffraction structure portion composed of a halftone dot light diffraction structure,
The halftone dot area ratio of the halftone dots constituting the light diffraction structure portion to the colored region is 15% to 60%, and each halftone dot is provided by being diffused by an error diffusion method with an area of less than 0.25 mm ^2. An image display body characterized by that.   The image display body according to claim 1, wherein the colored region is colored in a single color. Using a transfer sheet in which a light diffractive structure forming layer on which a light diffractive structure is formed is laminated on a base material sheet, the light diffractive structure forming layer is transferred in a halftone dot pattern to a colored region on a transfer target. A method of manufacturing an image display body that forms a light diffraction structure by:
Each halftone dot constituting the light diffractive structure has an area of less than 0.25 mm ² and is diffused by an error diffusion method so that a halftone dot area ratio with respect to the colored region is 15% to 60%. And transferring the image to the colored region.   The light diffractive structure forming layer is thermally transferred from the transfer sheet to the colored region using a thermal head, and each halftone dot is determined based on the printing energy applied to the thermal head based on the area and the area. 4. The method for producing an image display body according to claim 3, wherein the image is transferred while being diffused by the error diffusion method at a dot area ratio.   5. The method for producing an image display body according to claim 3, wherein the colored region of the transfer object is colored with a single color.

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