JP6284880B2 - Lenticular lens sheet - Google Patents

Description

Since the observed image differs depending on the viewing angle, the present invention provides a three-dimensional effect of a stereoscopic image by giving a moderate tan effect to the lenticular lens sheet that appears stereoscopically or changes. The present invention relates to a lenticular lens sheet in which an image is brought close to a natural one so that a change in an image moves naturally.

In general, a lenticular lens sheet has a configuration in which a plurality of different images are divided into strip-shaped bands, each band is sequentially arranged adjacently, and a lenticular lens is stacked thereon. Then, by observing the image through this lenticular lens, the image looks three-dimensional or changes. (Patent Documents 1 to 3)

Until now, as in Patent Documents 4 and 5, by improving the accuracy of the image and the concavo-convex lens, it has been devised to improve the sharpness of the image and clarify the stereoscopic effect of the stereoscopic image and the switching of the image. Has been done.

Registered Utility Model No. 3016876 JP 2000-298319 A Registered Utility Model No. 3058277 JP 11-84550 A JP 2008-77711 A

The conventional lenticular lens sheet has a problem that the eyes of the user are easily fatigued due to an unnatural three-dimensional effect or a gradual change in the observed image and excessive sharpness of the image.

The causes of the lenticular lens sheet image appearing unnatural or fatigued by the user's eyes can be broadly divided into the following two factors.

The first factor is considered to be that the three-dimensionality of the three-dimensional image of the lenticular lens sheet and the stepwise change of the image are created by a plurality of different planar and discontinuous images. An image recognized by a human in nature is a continuous image having a stereoscopic effect and perspective. On the other hand, since the stereoscopic image of the lenticular lens sheet is created by a plurality of different planar images, it appears as an unnatural image to human eyes. In particular, an image in which a plurality of images are changed in stages depending on the viewing angle is an image that is originally discontinuous, and thus further promotes an unnatural change.

The second factor is considered to be because the image of the lenticular lens sheet tends to appear too clear. For example, in the case of a 40 Lpi lenticular lens, the width of one bowl-shaped lens is about 0.6 mm, and the original image is further subdivided from the above-mentioned lens width. For this reason, lenticular lens sheets require the use of lenticular lenses and images that are highly accurate and have excellent clarity, and as a result, for example, objects that exist far away can be clearly and clearly reflected in the actual natural world. On the contrary, the sharpness of the image that cannot be obtained becomes an unnatural image.

As a solution to the above-mentioned prisoners, by combining sheets that have the effect of moderately distorting the image of the lenticular lens sheet, the stereoscopic effect of the image is changed to a natural texture, It is considered effective to make the gradual change more natural. In this case, there is a concern about the adverse effect due to the decrease in the sharpness of the image, but since the sharpness of the image of the lenticular lens sheet is generally high, even if the outline of the pattern or the like in the image is blurred, It is possible to identify the image of the lenticular lens sheet.

However, if the degree of tanning is excessive, the stereoscopic effect of the image of the lenticular lens sheet may be lost, and the change in the image may not be visible as originally designed. There is a problem that the image cannot be obtained and the image looks unnatural.

In addition, since the lenticular lens is disposed on the outermost surface of the lenticular lens sheet, there is a problem that it is easily scratched and lacks a high-class feeling because the touch feeling is rough.

The present invention provides a lenticular lens sheet that eliminates the three-dimensional image, the unnaturalness of the gradual change of the image, the susceptibility to scratching of the sheet surface, and the rough feel as described above.

The inventors of the present invention have made extensive studies on the improvement of the lenticular lens sheet that can make the stereoscopic effect of the lenticular lens sheet natural and make the change in the image of the lenticular lens sheet appear to move naturally. As a result, by laminating a sheet having a specific range of porosity and optical characteristics on the lenticular lens, the image of the lenticular lens sheet is imparted with a certain degree of blurring (or stagnation or fogging) effect. Has been found to be the most effective, and the present invention has been completed.

In addition, the conventional lenticular lens sheet has been devised to enhance the sharpness of the image and clarify the switching of the image, but the accuracy of the image and the concave-convex lens is lowered, or a non-transparent sheet is laminated. Thus, there has been no technical idea of actively reducing the sharpness of the image of the lenticular lens sheet, and such technical development has hardly been performed.

According to the present invention, since a fiber sheet is laminated on a conventional lenticular lens sheet, an image pattern or the like can be observed as if it exists in atmospheric fluctuations, so that the stereoscopic effect of the image is natural. Get closer to. At the same time, since the outline of the image is blurred, the change of the image becomes ambiguous, so that the change of the image seems to move naturally. Thus, the present invention provides a lenticular lens sheet that is gentle to the human eye. Moreover, it is strong against scratches and is improved to a smooth surface state.

It is sectional drawing of the lenticular lens sheet | seat of this invention.

That is, the lenticular lens sheet of the present invention balances the sharpness of the image of the conventional lenticular lens sheet and the wrinkle by the fiber sheet in order to solve the above-mentioned problems.

Specifically, the characteristics required for the fiber sheet laminated on the lenticular lens are porosity and optical characteristics, preferably the porosity is 20% or more and 80% or less, and the optical characteristics are the haze value H. Is 1 or more and 95 or less, the total light transmittance Tt is 60% or more, and the parallel-line transmittance Tp is 10%, more preferably the porosity is 30% or more and 65% or less, and the haze value H Is 15 to 90, the total light transmittance Tt is 85% or more, and the parallel light transmittance Tp is 40% or more.

The fiber sheet described in the present invention refers to Japanese paper / processed paper made of cellulose or paper-like paper made of organic synthetic polymer fibers. This organic synthetic polymer material is polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, fluororesin, poly (meth) acrylic acid (ester), poly (meth) acrylamide, poly (meth) acrylonitrile. It is made of a polymer material such as phenol resin, polyimide, polyamide, polyurethane, and polyester.

The porosity described in the present invention means that a sample is photographed with a microscope from the front in incident light, and the area (B) covered with fibers is subtracted from the total area (A). The figure divided by) is expressed as a percentage.
Porosity = (A−B) / A × 100

Here, the haze value H means the ratio (cloudiness) of diffuse transmitted light to the total transmitted light when the test piece is irradiated with light according to JIS-K7136, and haze according to JIS-K7136. It is measured by a meter (trade name: NDH-2000, manufactured by Nippon Denshoku Industries Co., Ltd.) as a ratio (Td / Tt) of diffuse transmittance PT to total light transmittance Tt described later.

Accordingly, it can be said that the smaller the haze value H is, the better the transparency is. However, in the case of the present invention, a haze value of a certain level or more is necessary in order to approximate a natural texture, and a haze value H of 15 or more is necessary. It becomes. However, if the haze value H is greater than 95, diffusion increases, and it becomes difficult to identify changes in the stereoscopic image or dynamic image of the lenticular lens sheet.

The total light transmittance Tt (based on JIS-K7361-1) means the ratio of the total transmitted light to the total incident light when the test piece is irradiated with light, and the total transmitted light is parallel to the diffuse transmitted light. And transmitted light.

Therefore, it can be said that the larger the total light transmittance Tt is, the better the brightness and transparency are. In the case of the present invention, if the total light transmittance Tt is preferably 80% or more, in the cloudy image of the lenticular lens sheet. In addition, it becomes possible to easily recognize the pattern of the image and its outline, and to grasp the change of the stereoscopic image and the dynamic image of the lenticular lens sheet. On the other hand, when the total light transmittance Tt is less than 60%, it is difficult to grasp the change in the stereoscopic image or dynamic image of the lenticular lens sheet.

The parallel light transmittance Tp (based on JIS-K7361-1) means the ratio of parallel transmitted light that travels straight in the traveling direction of the incident light with respect to the total incident light when the test piece is irradiated with light. It is expressed as a difference between the total light transmittance Tt and the diffuse transmittance Td.

Therefore, it can be said that the larger the parallel light transmittance Tp, the better the clarity and transparency. However, in the case of the present invention, a balance between the sharpness of the image and the degree of blur is achieved, and a certain blur effect is imparted. Therefore, if the parallel light transmittance Tp is preferably 40% or more, the pattern in the image and its outline are stunned, but the change in the stereoscopic image or dynamic image of the lenticular lens sheet is fully recognized. As a whole, the image looks gentle on the human eye. On the other hand, when the parallel light transmittance Tp is less than 10%, it is difficult to visually recognize the pattern of the image and its outline.

The diffuse transmittance Td (conforming to JIS-K7136-1) means the ratio of diffused diffused light diffused with respect to all incident light when a test piece is irradiated with light. Therefore, it can be said that the smaller the diffuse transmittance Td is, the better the clarity and transparency are. However, the diffuse transmittance Td is also the relationship between the above-mentioned total light transmittance Tt and the parallel light transmittance Tp. In the invention, the diffuse light transmittance Td is specified adjointly by specifying the total light transmittance Tt and the parallel light transmittance Td, and all optical characteristics required for the fiber sheet are determined.

In the lenticular lens sheet of the present invention, it is particularly preferable to use Japanese paper or processed paper as the fiber sheet. Since Japanese paper or processed paper is formed by complex intertwining of a large number of fibers, the desired porosity and optical properties of the Japanese paper or processed paper, that is, haze value H, light transmittance Tt and parallel light transmittance If Tp is specified, a fiber sheet useful for the present invention in which the fiber diameter, fiber orientation, density, and the like of Japanese paper or processed paper are inevitably adjusted can be selected.

When Japanese paper or processed paper is used as the fiber sheet, the image of the lenticular lens sheet reaches the human eye through the gap between the fibers. Therefore, even if a fiber sheet made of Japanese paper or processed paper is laminated on the lenticular lens, the lenticular lens sheet of the present invention does not change the refractive index of the lenticular lens. The change of the target image can be projected.

Furthermore, the hand feeling of Japanese paper or processed paper is a smooth material created by a large number of fibers, and is therefore suitable as a sheet material that enhances the texture. Also, Japanese paper or processed paper has many fibers intricately and tightly intertwined, so that it can protect the surface of the lenticular lens and can also serve as a sheet material for reinforcing the lenticular lens sheet itself.

In addition, Japanese paper or processed paper is less susceptible to static electricity and easier to write than resin lenticular lenses and other plastic sheets, so the application of Japanese paper or processed paper has the antistatic function of lenticular lens sheets. There is also an effect of improving writing characteristics.

In the present invention, the fiber sheet is preferably in close contact with the lenticular lens from the viewpoint of improving physical strength and visibility. The adhesion method is not particularly limited, but it can be physically bonded such as by pressing along the concave-convex lens surface, chemically bonded using a resin adhesive or adhesive, or lightly It can also be heat-welded by hot pressing. If the resin is embedded in the uneven surface of the lens, the image becomes unclear and obstructs the effect of the fiber sheet.

1. Test method The porosity of the sheet material used as the fiber sheet laminated on the lenticular lens is measured using image processing, and the haze value H, total light transmittance Tt, diffuse transmittance Td, parallel light is measured. The optical characteristics of the transmittance Tp were measured using a haze meter.
Next, the sheet material whose optical characteristics were measured was laminated on the lenticular lens of the same lenticular lens sheet as shown in FIG. 1, and the visibility was visually evaluated.

2. Image processing The lenticular lens sheet having the configuration shown in Fig. 1 was imaged with a microscope under incident light and lens magnification of 50 times, and the image was binarized and the porosity was measured. . If the magnification of the lens is too low, the depth of focus will be deep and the lenticular lens will be focused even on the uneven surface, so that the desired image cannot be obtained, so it is necessary to select an appropriate lens magnification. Become.

3. Measurement method of optical properties The haze value H of the fiber sheet is JIS-K7136, the total light transmittance Tt, the diffuse transmittance Td, and the parallel light transmittance Tp are DENKI in accordance with JIS-K7361-1. It measured using the color industry company make haze meter (brand name: NDH-2000).

4). Evaluation of visibility Visibility was evaluated by visual observation of changes in a stereoscopic image and a dynamic image of a lenticular lens sheet on which fiber sheets were laminated by 10 panelists.
In the evaluation, each lenticular lens sheet on which each fiber sheet was laminated was given a score of 1 to 4 points based on the evaluation criteria shown in Table 1, and an average score was calculated from the total score.
From the average score of the lenticular lens sheet, 4 or more points are “◎”, 3 points or more and less than 4 points are “◯”, 2 points or more and less than 3 points are “△”, and less than 2 points are “×”. “◎” is a sheet in the most preferable range, “◯” is a sheet in the preferable range after “◎”, and “Δ” and “×” are sheets that are not suitable for the fiber sheet of the present invention. As evaluated.

5. Fiber sheet material (1) Japanese paper (chlorine-free material book, made by Hidaka Washi)
Basis weight (g / m ² ) 2.0; 3.5; 5.0; 7.3; 9.0
(2) Palette color paper (20 g / m ² , manufactured by Takeo)
Color: White; Straw; Pink; Blue; Red; Yellow; Green (3) Palette color / paraffin paper (20 g / m ² , manufactured by Takeo)
Color: White; Straw; Pink; Blue; Red; Yellow; Green (4) Other general paper types ... White glassine paper (manufactured by Takeo); Classico tracing paper (A size T 30kg, GL Tracing paper (A book size T / Y 35.5kg, Takeo company); Tengu paper (Ogino); Master paper processing base paper (Ogino); Paper (manufactured by Ogino); high-quality paper for copying (multi-paper super economy, manufactured by ASKUL)
(5) Resin sheet type: PVC sheet (Sumitomo Bakelite, VSS-3701, 0.1 mm); PVC sheet (Hanashin, A7, 0.5 mm); TAC sheet (LOFO, Tacphan R862SM, 0.04 mm); PET sheet (manufactured by Taiheisha, PG-700M, 0.36 mm)

Table 2 shows evaluations of porosity, optical characteristics, and visibility for Japanese paper having different basis weights.

As shown in Table 2, when Japanese paper is used as the fiber sheet, regardless of the basis weight, excellent visibility in which the sharpness of the image and the degree of image fringing are highly balanced for all types of Japanese paper Can be obtained. However, when the basis weight decreases, the haze value H tends to decrease, and the degree of cloudiness of the image tends to be slightly lacking. Conversely, when the basis weight of the Japanese paper increases, the parallel light transmittance Tp decreases and the pattern of the image slightly increases. There is a tendency for the visibility of the outline of the to decrease.

Table 3 shows the evaluation of optical characteristics and visibility for palette color papers with different colors.

As shown in Table 3, when general processed paper such as pallet color paper is used as the fiber sheet, the parallel light transmittance Tp for pallet color paper of all colors is small regardless of the color. Therefore, neither a contour of a pattern in the image nor a stereoscopic image and a dynamic image can be visually recognized.

Table 4 shows the evaluation of optical characteristics and visibility of palette colors and paraffin papers having different colors.

As shown in Table 4, when pallet color / paraffin paper is used as the fiber sheet, the visibility evaluation differs depending on the color, unlike pallet color paper. This is because the transparency of the paper, especially the parallel light transmittance Tp, was improved by paraffin processing the palette color paper, and the visibility of the contour of the image pattern and the like was improved relative to the parent color paper. Conceivable. However, when a dark color such as red is used in the palette color / paraffin paper, both the total light transmittance Tt and the parallel light transmittance Tp are lowered, so that the contour of the pattern in the image is also a three-dimensional image. In addition, almost no dynamic image can be visually recognized.

Table 5 shows the evaluation of optical characteristics and visibility for Japanese paper and processed paper with different paper types.

As shown in Table 5, glasso paper with improved paper transparency (watermark) as a fiber sheet,
When processed paper such as tracing paper is used, the degree of crease is strong and it becomes difficult to visually recognize the contour of a pattern or the like in the image, but it is possible to clearly grasp a stereoscopic image and a dynamic image. . In addition, when Japanese paper such as traditional paper is used as the fiber sheet, the parallel light transmittance Tp is particularly improved, so that an image with good visibility of the contour of a pattern or the like can be obtained, and the image clarity and image Excellent visibility with a balance of tanning is obtained. On the other hand, when a processed paper whose transparency (watermark degree) is not improved, such as copy quality paper, both the total light transmittance Tt and the parallel light transmittance Tp are lowered, so that the image The outline of the inside pattern and the like as well as the stereoscopic image and the dynamic image can hardly be visually recognized.

Table 6 shows the evaluation of optical characteristics and visibility of the resin sheet.

As shown in Table 6, when a resin sheet is used as the fiber sheet, a lenticular lens sheet in which the balance between the sharpness of the image and the degree of fringing is obtained is slightly inferior to that of paper. In particular, when the fiber sheet is a thin PVC sheet, the haze value H tends to be small and the image is slightly less cloudy. Conversely, the fiber sheet is a thick PVC sheet or TAC sheet. However, the parallel light transmittance Tp tends to be small, and the visibility of the contour of the image pattern or the like tends to decrease. Further, when the fiber sheet is a PET sheet, both the total light transmittance Tt and the parallel light transmittance Tp are lowered, so that the outline of the pattern in the image and the stereoscopic image and the dynamic image are almost visually recognized. Can not be.

In particular, as a fiber sheet suitable for the purpose of the present invention, a sheet made of Japanese paper or processed paper is more suitable than a resin sheet, and Japanese paper is more preferable than processed paper.

In the resin sheet, visible light is uniformly transmitted through the material and reaches the human eye by changing the refraction of the lenticular lens sheet, so that a tan effect is obtained but a natural texture is given to the image. I can't. On the other hand, in the fiber sheet made of paper or processed paper, visible light reaches the human eye non-uniformly through the gaps between the fibers and the fibers, so that the transition is natural.

In addition, a sheet made of Japanese paper or processed paper is less likely to be charged with static electricity and easy to write as compared with a resin sheet, and thus can be used to prevent static charge and improve writing characteristics of the lenticular lens sheet.

In addition, Japanese paper sheets are more suitable than processed paper sheets because, in general, Japanese paper fibers are longer than processed paper fibers, and their density is sparse. This is because the gap between the fibers to be effectively passed is larger than that of the processed paper, which is advantageous for balancing the sharpness of the image and the degree of wrinkling.

1 .... Lenticular lens sheet 2 .... Image sheet 3 .... Print surface 4 .... Lenticular lens 41 ... Uneven lens surface 5 ... ... Fiber sheets

Claims (4)

An image sheet having a printing surface in which a plurality of different images are divided into strip-like strips arranged in parallel, and each strip is sequentially arranged adjacently;
A lenticular lens laminated on the image sheet, and a lenticular lens sheet comprising a fiber sheet laminated on the lenticular lens ,
The lenticular lens sheet, wherein the fiber sheet has a haze value H of 15 or more and 90 or less, a total light transmittance Tt of 85% or more, and a parallel light transmittance Tp of 40% or more.   The lenticular lens sheet according to claim 1, wherein the fiber sheet has a porosity of 20% to 80%.   The lenticular lens sheet according to claim 2, wherein the fiber sheet has a porosity of 30% to 65%. 2. The lenticular lens sheet according to claim 1, wherein the fiber sheet and the lenticular lens sheet are bonded only by a convex portion of the lens, and the concave portion of the lens does not contain a resin or fiber .

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