JP7306181B2 - Moire display, pattern for expressing moire image, pattern generation method, and pattern generation system - Google Patents

Description

The present invention relates to a moire display, a pattern for expressing a moire image, a pattern generation method, and a pattern generation system.

"Moire (also called moire)" is interference fringes that occur when multiple periodic patterns or structures are superimposed, and a moire image that expresses moire in a visible state is called a moire image. Physically, moiré can be said to be a beat phenomenon of two spatial frequencies.
Moire occurs in various forms, and while moire may be removed as undesirable, it may also be used as a useful moire.

For example, Patent Document 1 discloses an image forming member having a latent image as an example of using a moire image for preventing counterfeiting/duplication. In this image forming body, wavy lines that are transverse waves and a line pattern that is substantially perpendicular to the wavy lines in the background of the wavy lines are provided on a base material, and the wavy lines forms a relief image, and the parallel line pattern is composed of a latent image portion shifted by 1/2 pitch and a non-latent image portion other than the latent image portion.

Further, Japanese Patent Laid-Open No. 2002-200000 discloses a method of manifesting a moiré image using a copying machine or a pattern discriminating tool while shifting the phase of a part of a pattern in order to prevent forgery/duplication.

Japanese Patent No. 4403694 Japanese Patent No. 4457220

By the way, the moiré image displayed in the prior art is generally a binary moiré image represented by black and white binary values. Such a binary moiré image cannot be controlled appropriately for its sharpness and blurring, which sometimes results in an unclear image or a finish that is inferior to the design design.

The clarity of the displayed moire image depends on the pattern in which the moire is displayed. That is, when it is desired to express a clear moire image, it is preferable that the lines of the pattern are clear. The clearest moire image is obtained when the ratio of openings to non-openings in the pattern is equal, that is, when the pattern is a rectangle of openings:non-openings=1:1. Apertures and non-apertures will be described later.

When a pattern that expresses moire is realized by printing, for example, if pitch change or phase shift is used as in the conventional technology, limitations due to resolution and pitch will occur, so moire images cannot be expressed by rectangular representation. Movement of pitch and phase is limited.
Also, if the difference in transmittance of the pattern between the aperture and the non-aperture is small, or if the boundary between the aperture and the non-aperture is blurred, the contrast of the pattern or moire display as a whole will be low, and the moire image will be inadequate. becomes clear.

The present invention has been made in view of such problems. It is an object of the present invention to provide a pattern generation system.

A moire display body according to the present invention is a moire display body in which a plurality of patterns including openings and non-openings are formed, wherein the average transmittance of the openings is higher than the average transmittance of the non-openings, and the openings The difference between the maximum transmittance of the portion and the minimum transmittance of the non-opening portion is 1% or more, and when the plurality of patterns partially overlap, at least the pattern on the back side can be seen through the opening portion of the pattern on the front side. A moire image is developed by being viewed as an image, and the pattern can change the degree of moire pattern blur within the display surface, and the degree of moire pattern blur is determined by at least one of a gradient area, a gradient area, and a gradient angle. Defined.

According to the present invention, it is possible to provide a moire display body using a pattern that can obtain a clear moire image, a pattern that expresses a moire image, a pattern generation method, and a pattern generation system when using moire for design. can.
As a result, it is possible to obtain moire images and moire image display bodies that are clearer and have more gradation than conventional techniques. By setting the part ratio and the degree of moire pattern blurring, it is possible to efficiently create a superimposed pattern.
Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

FIG. 1 is a diagram showing a typical example of a basic pattern as a moire pattern. FIG. 2 is a schematic diagram showing an example of opening/non-opening setting when transmittance is adopted as a characteristic value and rectangular wave-like transmittance is obtained. FIG. 3 is a schematic diagram showing an example of opening/non-opening setting when a sinusoidal transmittance is obtained by adopting transmittance as a feature value. FIG. 4 is a diagram for explaining the degree of moiré pattern blurring due to gradient regions. FIG. 5 is a diagram for explaining the degree of moire pattern blurring based on the gradient area. FIG. 6 is a diagram for explaining the degree of moire pattern blurring depending on the gradient angle. FIG. 7 shows printed matter with different degrees of moire pattern blurring, each showing an example formed on a PET base material by a UV inkjet printer. FIG. 8 is a diagram schematically showing a moire display. FIG. 9 is a cross-sectional view of a structural example (basic form) of the display. FIG. 10 is a cross-sectional view of another configuration example (panel/film split type) of the display. FIG. 11 is a cross-sectional view of another structural example (direct printing type) of the display. FIG. 12 is a cross-sectional view of another structural example (gap type 1) of the display. FIG. 13 is a cross-sectional view of another configuration example (gap type 2) of the display. FIG. 14 is a diagram schematically showing an example of an input image for which a moiré image is to be generated. FIG. 15 is a diagram for explaining layer information. 16A and 16B are diagrams showing examples of the basic pattern of the stripe pattern used in this embodiment and the pattern with the opening/non-opening ratio changed. FIG. 17 is a diagram showing an example of an input image in this embodiment. FIG. 18 is a diagram showing an output pattern example on the near side. FIG. 19 is a diagram showing an example of an output pattern on the far side. FIG. 20 is a diagram showing the results of appearance evaluation in Examples. FIG. 21 is a diagram showing the difference in observation state of the pattern due to the difference in the phase variation amount of the phase with respect to the aperture. FIG. 22 is a diagram showing the difference in observation state of the pattern due to the difference in the phase variation amount of the phase with respect to the opening. FIG. 23 is a schematic diagram of a pattern generation system SYS that develops a moire image.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The present invention is not limited to the embodiments described below, and modifications such as design changes can be made within the scope of the present invention based on the knowledge of those skilled in the art. Modified embodiments may also be included in the present invention.

Below, the pattern which expresses a moire image is demonstrated first.

<Moire pattern>
As used herein, the term "moiré pattern" (also simply referred to as "pattern") means a periodic pattern or structure that is superimposed to generate moiré.
Also, a pattern used as a base when generating a moiré pattern is referred to as a "basic pattern".

FIG. 1 shows typical examples of basic patterns, including a linear pattern (FIG. 1(a)) as a unidirectional pattern and a lattice pattern (FIG. 1A) as a bidirectional pattern. (b)), check pattern (FIG. 1(c)), and the like. The basic pattern is not limited to these, and as a unidirectional pattern, instead of a straight line pattern, a waveform pattern, a zigzag pattern, a pattern consisting of repeated characters, or the like may be used. Moreover, as the bidirectional pattern, it is possible to use not only a geometric pattern such as dots (polka dots) but also a pattern consisting of chaotic designs, characters, and the like. Information representing these is called basic pattern information.

In the present specification, the term "characteristic value of pattern" refers to transmittance, reflectance, optical density, ink density, lightness, grayscale level (grayscale value), and the like.
Characteristic values of patterns are obtained from image data for pattern printing, from image data converted by photographing the printed pattern with a scanner or camera, or by irradiating the printed pattern with laser light. can be obtained by measuring the reflected light by

Furthermore, in the present specification, the "opening/non-opening ratio" is a new concept indicating the properties of a pattern, and is different from conventional information such as line width, pitch, and L/S (Line & Space) ratio. are different. The "opening/non-opening ratio" will be described below.

<Ratio of opening/non-opening>
The pattern is repeated at regular intervals. Therefore, the feature values of the pattern also change periodically. In such a periodically changing pattern, a portion having a high characteristic value in terms of brightness or transparency can be set as an opening, and portions other than the opening can be set as a non-opening. The area ratio between the aperture and the non-aperture is called the aperture/non-aperture ratio.

Specifically, in one period of the pattern, a portion where the feature value is equal to or greater than the threshold value can be set as the opening. When determining the threshold value, the average value or the median value of the feature values of the entire pattern may be used, or the maximum value and the minimum value may be normalized and the integrated ratio may be used.
Furthermore, FFT (Fast Fourier Transform) may be used to determine aperture/non-aperture.

Also, one or more specific regions in the pattern may be regions that are neither openings nor non-openings, which are not classified as openings or non-openings, regardless of the above conditions. Here, the specific region is, for example, a pattern, character, or pattern that is intentionally provided for the purpose of design, or a region corresponding to stains or omissions that may occur during manufacturing.

In the case of a linear pattern (FIG. 1(a)), which is a unidirectional pattern, the characteristic value is obtained using the pattern period in the direction perpendicular to the direction in which the straight line extends, and the lattice pattern (FIG. 1(b) ), the feature values are obtained along the two directions in which the pattern appears periodically.

<Transmittance of moire pattern>
When an observer observes the pattern, the higher the contrast, the more clearly the pattern can be perceived.
The appearance of the pattern varies depending on the color difference, saturation, and brightness, but it is also affected by the color tone. In addition, when patterns are superimposed, it affects the visibility of the pattern on the back side that is seen through the pattern on the front side. is large.

Therefore, in order to make the pattern clearer, it is preferable to provide a difference in transmittance between the openings and the non-openings. Specifically, the average transmittance of the apertures defined by the feature values is higher than the average transmittance of the non-apertures, and the difference between the maximum transmittance of the apertures and the minimum transmittance of the non-apertures is 1 % or more, and more preferably 5% or more.

FIG. 2 is a schematic diagram showing an example of opening/non-opening settings when transmittance is adopted as a characteristic value and rectangular wave-like transmittance is obtained, and (a) shows an actual pattern. , (b) show the transmittance associated with the pattern.

In this example, the area showing the maximum value of the transmittance (the white rectangular portion of the pattern) is the opening, and the other area (the solid black rectangular portion of the pattern) is the non-opening portion. As shown in FIG. 2(b), the maximum transmittance of the opening is 100%, the minimum transmittance of the non-opening is 0%, and the difference between them is 100%.

FIG. 3 is a schematic diagram showing an example of aperture/non-aperture settings when sinusoidal transmittance is obtained using transmittance as a characteristic value, and (a) shows an actual pattern. , (b) shows the transmittance associated with the pattern, and (c) shows the pattern formed by the halftone dot image.

In this example, the transmittance of the pattern changes steplessly from 0% to 100%, but the area showing the average value (transmittance of 50%) or more becomes the opening, and the other area becomes the non-opening. As shown in FIG. 3(b), the maximum transmittance of the opening is 100%, the minimum transmittance of the non-opening is 0%, and the difference is 100%.

<Moire pattern blur>
In addition to the contrast, the clearness of the pattern is not only the contrast, but the larger the gradation difference in the contour portion, the clearer the pattern is perceived, and the clearer the moire image developed by the pattern.

The contour portion is the border between the opening and the non-opening in the pattern, and is the front and rear region including the points separating the opening/non-opening by the selected feature value.

The gradation difference of the contour portion is the gradient of variation of the feature value in the front and rear areas including the point separating the aperture/non-opening by the selected feature value at the boundary between the aperture and the non-opening.

As means for measuring the gradation difference of the contour portion, there is a method of obtaining and utilizing the gradient area, the gradient area, and the gradient angle using the characteristic values of the pattern. Further, by evaluating the numerical value (dimensionless quantity) obtained by these as the "moire pattern blurring degree", the clarity of the pattern can be defined, and a clearer moire image can be stably obtained.

Here, focusing on the variation of the characteristic value of the pattern when passing through the point separating the opening/non-opening, there are at least two gradients in one cycle of the pattern. There are gradients that change from non-aperture to aperture, and gradients that change from non-aperture to aperture. The moiré pattern blurring degrees may be the same or different, but if they are different, the evaluation based on the moiré pattern blurring degree is determined by the gradient with the larger blurring.

Moreover, it is also possible to vary the degree of moiré pattern blurring in a plurality of cycles of the pattern. The moire pattern blurring degree can also use the average value of evaluation values for each gradient in a plurality of cycles.

Moiré patterns can be used more effectively by using different degrees of moiré pattern blurring (also simply referred to as blurring degrees) in the design drawing. In other words, the moire pattern has a strength distribution within the display surface. The distribution can be uniform, or the degree of blur can be different depending on the position within the display plane. For example, by decreasing the degree of blurring in the main area in the design drawing and increasing the degree of blurring in areas other than the main area, the sense of perspective can be enhanced. It is also possible to reduce the degree of blurring in portions where moire phase fluctuations are small and increase the blurring degree in portions where moire phase fluctuations are large.

This blur distribution may be continuous or discontinuous. If it is continuous, it is easy to visually recognize a natural wavy shape, and if it is discontinuous, it is easy to display an image with a modern impression. Also, the distribution of the degree of blurring may be associated with a moire pattern, or may form a different pattern. When associated with the moire pattern, the moire pattern is easily emphasized. When a pattern different from moire is formed, it is easy to realize a more complicated pattern.

Further, the blurring of the moire pattern can be formed by adjusting the density of halftone dots. That is, it can be expressed in printing as a difference in halftone dot density. Also, the difference in halftone dot density can be realized by a difference in halftone dot size, a difference in density, or both, as shown in FIG. 3(c). At this time, the number of lines of the halftone dots is preferably within a range in which no moire image occurs in relation to the number of lines of the moire pattern. There is little effect on the resolution of the moire image to be expressed. It is preferable that the number of printing lines is finer than three times the moire pattern pitch, because unintended moire due to the moire pattern and the printed lines does not occur. Further, the fineness of the number of lines (the numerical value of the number of lines increases) can be selected according to the performance of the printing machine.
On the other hand, the roughness of the number of lines (the numerical value of the number of lines becomes smaller) is too coarse to draw blur, and when the moire patterns are superimposed, unintended moire due to printed lines and printed lines can be seen. It is desirable to make the roughness up to about 60 lines. However, if you want to use more lines for design reasons, this is not the case.

1) Definition by Gradient Area The gradient area is a diagram drawn with the characteristic value of the pattern existing between the opening and the non-opening on the vertical axis and the position on the pattern on the horizontal axis. It refers to an area extending from the maximum value to the minimum value of the feature values across the point separating the aperture/non-aperture (FIG. 4).

The moire pattern blurring degree is determined by Equation (1) based on the gradient area, where the half period of the pattern is the pitch.
Moire pattern blur by gradient area=gradient area/pitch (1)
In this case, the degree of moire pattern blur due to the gradient area is preferably 0.6 or less, more preferably 0.4 or less. Note that the lower limit value is 0 because moiré occurs even when there is no blurring (pattern blurring degree is 0). However, it is desirable that the degree of moire pattern blur due to the gradient area is 0.2 or more, because a blurred image can be made to look better than without blur.

2) Definition by Gradient Area Gradient area is defined by the following: With the point separating the opening/non-opening as a boundary, the area α obtained by integrating the difference between the maximum feature value and the diagram on the opening side, and the minimum feature value and the diagram on the non-opening side. The area (α + β) obtained by summing the area β obtained by integrating the difference. In other words, the gradient area is the sum of the areas between the rectangular diagram of maximum and minimum values that can be taken by the feature values and the waveform diagram formed by the feature values of the pattern (FIG. 5).

Based on the gradient area, the moire pattern blurriness is determined by equation (2).
Moiré pattern blur due to gradient area = gradient area/pitch (2)
Further, at this time, the degree of moire pattern blurring due to the gradient area is preferably 0.1 or less, and more preferably 0.07 or less. The lower limit is 0, because moiré occurs even when there is no blurring (pattern blurring degree is 0). However, it is desirable that the degree of moire pattern blurring due to the gradient area is 0.01 or more, because a blurred image can be made to look better than a blurred image.

3) Definition by slope angle The slope angle is defined by taking the characteristic value of the pattern existing between the opening and the non-opening on the vertical axis and the position on the pattern on the horizontal axis, and dividing the opening/non-opening. It refers to the slope of a diagram drawn from the maximum value to the minimum value of the feature values through the dividing point (FIG. 6).

The gradient angle [deg] can be obtained by the following formula (3).
Gradient angle = tan ^-1 {(maximum feature value - minimum feature value)/gradient region} (3)

Based on the gradient angle, the moire pattern blurriness is determined by equation (4).
Moiré pattern blur due to gradient angle = 90 - gradient angle (4)
At this time, the moire pattern blurring degree due to the gradient angle is preferably 30 or less, and more preferably 21 or less. The lower limit is 0, because moiré occurs even when there is no blurring (pattern blurring degree is 0). However, it is desirable that the degree of moire pattern blurring due to the gradient angle is 10 or more, because it is possible to create a better-looking image with blurring than without blurring.

Specific examples of printed matter with different moire pattern blurring degrees and calculation examples of the moire pattern blurring degrees are shown. FIG. 7 shows printed matter with different degrees of moire pattern blurring, each showing an example formed on a PET base material by a UV inkjet printer. When the grayscale luminance when scanned at 600dpi by a scanner is averaged for 400px in the same direction as the stripe, normalized by the maximum and minimum values and used as a feature value, the moire pattern blur due to the gradient area is It is 0.46 for the moire pattern of FIG. 7(a) and 0.38 for the moire pattern of FIG. 7(b). The moire pattern blurring degree based on the gradient area is 0.04 for the moire pattern of FIG. 7(a) and 0.08 for the moire pattern of FIG. 7(b). Furthermore, the degree of moiré pattern blurring due to the gradient angle is 21 for the moiré pattern of FIG. 7(a) and 25 for the moiré pattern of FIG. 7(b).

The method of calculating the degree of moire pattern blurring of a pattern based on pattern feature values has been described above. It is discrete data sampled according to the laser beam diameter and the like when measuring by irradiating a laser beam on the area, and depending on the sampling interval, the degree of moire pattern blurring is not limited to the specified limits.

<Information on moire display>
FIG. 8 is a diagram schematically showing a moire display. In this specification, a "moire display" (also simply referred to as a display) means a display that can express a moire image, and is generally assumed to be a poster, a panel, a POP advertisement, or the like. At least a portion of the moire display is made of a material that can transmit light.

Here, information such as the size of the expression area 6, the thickness of the panel (also called "gap") 5, the refractive index of the material constituting the panel, and the "visible distance" which is the distance from the average observer to the expression area. is information about the moire display 4 (moire display information).

For example, three-dimensional moiré can be observed when one pattern is viewed through the other pattern among patterns with different distances from the observer. Since stereoscopic moiré is caused by binocular parallax of the observer, information regarding the positional relationship between the observer and the panel is required for calculating the parallax.
Basically, when the height of the center of the expression area 6 and the viewer's eyes match, the distance between the viewer and the panel is the visible distance.
If the center of the expression region 6 does not match the height of the observer's eye, or if the height of the position where the moiré image is generated does not match the height of the observer's eye, the "visible distance ” can be corrected by the relationship between the moiré occurrence location and the position of the observer's eyes.

The pattern in this embodiment and the output pattern output by the pattern generation system to be described later are two types of patterns, a moire pattern A (front side) and a moire pattern B (back side).
Patterns that produce a moire image are premised on being superimposed, and the pattern closer to the observer is called the front side pattern, and the one farther from the observer is called the back side pattern. When the patterns partially overlap each other, at least the pattern on the back side can be seen through the opening of the pattern on the front side, so that a moire image appears.

<Construction of Display>
FIG. 9 is a cross-sectional view of a structural example (basic form) of the display. In the example of FIG. 9, films F1 and F2 printed with pattern layers PL1 and PL2 are attached to the front and rear surfaces of the panel PN. Here, the "pattern layer" means a layer on which a pattern is drawn by printing or the like. Pattern layers PL1 and PL2 in FIG. 9 have moire pattern A and pattern B, respectively, output by the pattern generation system.

In the case of this basic form, patterns A and B are printed on the panel PN side of the films F1 and F2, respectively, and the panel PN and the patterns A and B are in contact with each other. Therefore, the thickness (gap) and refractive index of a single panel PN should be taken into account when performing pattern generation.

FIG. 10 is a cross-sectional view of another configuration example (panel/film split type) of the display. In the example of FIG. 10, the panel is divided in the thickness direction into panel PN1 and panel PN2, and the lower film is divided in the plane direction into film F2 and film F3. Other than that, it is the same as the display body of FIG.

The dividing direction of the panel is not limited to the thickness direction, but may be the surface direction of the panel, and the number of divisions and the manner of division can be freely set. By dividing the panel or film, it becomes easy to maintain the accuracy of installation and bonding of the display body when the display body has a large area.

FIG. 11 is a cross-sectional view of another structural example (direct printing type) of the display. In the example of FIG. 11, the pattern layers PL1 and PL2 are directly printed on the front and back surfaces of the panel PN. Since a resin layer such as UV ink is laminated on the panel PN to form a display body without using a film or the like, the step of attaching the film layer can be omitted.

Only one of the pattern layer PL1 or the pattern layer PL2, or a portion of the pattern layer PL1 or the pattern layer PL2, is directly printed. A printed film may be adhered to serve as a display.

FIG. 12 is a cross-sectional view of another structural example (gap type 1) of the display. In the example of FIG. 12, a gap CL is provided between the panel PN1 and the panel PN2. The gap CL is filled with a medium having a refractive index different from that of the panel, such as air, liquid (water, oil, etc.).

The gap of the display body shown in FIG. 12 is the distance from the pattern layer PL1 to the pattern layer PL2, and the refractive index thereof is a combination of the refractive indices of the panel PN1, the panel PN2, and the filler in the gap CL. .

Since the display as shown in FIG. 12 can be divided in the thickness direction, it is possible to use the glass of a show window, an automatic door, etc. as the panel PN1 and the panel PN2, and install it in existing equipment. It has the advantage of being easy. Further, by installing the panel PN1 and the panel PN2 in an automatic door or the like, the panel PN1 and the panel PN2 can be slid relative to each other, thereby further enhancing the effect when a moire image is generated.

FIG. 13 is a cross-sectional view of another configuration example (gap type 2) of the display. In the example of FIG. 13, the film F1 and the film F2 printed with the pattern layers PL1 and PL2 are attached to the inner surfaces of the panel PN1 and the panel PN2, respectively, and the gap CL is provided between the film F1 and the film F2. there is

When the panel PN1 and the panel PN2 are display panels installed outdoors, adopting such a configuration also makes it possible to protect the films F1 and F2 from the outdoor environment.

In the case of FIG. 13, the gap is the distance from the pattern layer PL1 to the pattern layer PL2, and its refractive index is a combination of the refractive indices of the film F1, the film F2, and the filler in the gap CL.

The structure of the display has been described above. Whether the pattern layer is provided between the film and the panel or on the opposite side can be determined as appropriate. It is preferable to provide

Moreover, it is possible to partially combine or change the configurations described in FIGS. 9 to 13 .
Furthermore, panel PN1 and panel PN2 may be the same or different. The films F1 and F2 may be the same or different.

<Characteristics of moire appearance>
The difference in the pitch and opening/non-opening ratio between moire pattern A (front side) and moire pattern B (back side), and the difference between moire pattern A (front side) and moire pattern B (back side) Due to the existence of the gap, the moire image has the following effects in combination.

<Moire strength>
Moire images tend to appear more strongly as the opening/non-opening ratios of moiré pattern A (front side) and moiré pattern B (back side) are closer to 1, and this tendency is called moiré intensity. Further, even if the aperture/non-aperture ratio is the same, the moire intensity tends to increase if the moire pattern blurring degree is small.

<Appearance density>
In the present specification, the term “appearance density” means the degree of apparent density due to the difference in ratio of openings/non-openings in moiré pattern A (front side) and moiré pattern B (back side). do. The pattern and the moire image tend to appear brighter as the opening/non-opening ratio of the pattern increases. Also, even if the aperture/non-aperture ratio is the same, the appearance density may differ depending on the degree of moiré pattern blurring.

<Moire variation>
Since the moiré pattern A (front side) and the moiré pattern B (back side) overlap with each other with a gap interposed therebetween, the moiré phase differs depending on the position (angle) of the observer. At this time, the higher the aperture/non-aperture ratio, the easier it is for the moire image to remain bright, and the lower the aperture/non-aperture ratio, the easier it is for the moire image to remain dark (that is, it tends to change less). In addition, there is a tendency that the closer the opening/non-opening ratio is to 1, the larger the amount of change in moire.

<Evaluation of moire appearance>
When evaluating the appearance of the moire image, the above effects and the like are observed in a composite manner. In addition to these effects, moire appearance characteristics can also be evaluated from the viewpoint of "moire resistance," which is the extent to which moire images can be seen even when the viewing distance is longer than expected. There is

In the present embodiment, the moire appearance is evaluated by paying attention to the ratio of openings to non-openings of the pattern, and the suitability for using the moire image as a design is comprehensively judged.
Specific judgment levels are divided into comparative methods and graded evaluations such as 3 stages (○△×, etc.).
In addition to the overall evaluation, additional evaluations such as moire image brightness and moire image mobility of external appearance may be additionally performed. However, depending on the design you want to express, what is important differs, so evaluation may or may not be performed.

Further, in the present embodiment, when generating the moire pattern A (front side) and the moire pattern B (back side) from the input image, the result of this appearance evaluation is used as a reference to determine the opening/non-opening ratio. will be selected.
In general, the appearance of a moire image differs depending on conditions such as the pattern used, the composition of the image, and the viewing environment. Therefore, it is desirable to evaluate each specific attribute in addition to the comprehensive appearance evaluation. Therefore, in this specification, the following attributes are also evaluated.

<Moire image intensity>
“Moire image intensity” means evaluation of apparent brightness (brightness and darkness) in the appearance of a moire image. This moire image intensity differs mainly due to the multiple effects of moire intensity and appearance density. The evaluation is carried out by a comparative method or by graded evaluation such as 11 grades (dark: -5, -4, ..., 4, 5: light).

<Moire image mobility>
“Moire image mobility” means an evaluation of movement and flickering of a moire image among appearances of the moire image. The difference is mainly due to the multiple effects of moire intensity and moire movement amount. The evaluation is carried out by a comparative method or by graded evaluation such as 6 stages (small: 0, 1, ..., 4, 5: large).

<Input information>
1, 8, 14, and 15 are diagrams for explaining an outline of input information in a pattern generating system for expressing a moire image. Input information to the generation system includes characteristic values of the input image (FIG. 14), layer information (FIG. 15), information on display objects (FIG. 8), and basic pattern information (FIG. 1).

<Input image and feature values>
FIG. 14 is a diagram schematically showing an example of an input image for which a moiré image is to be generated. In this specification, the "input image" means data of an image to be moire-processed, such as a design pattern. In FIG. 14, in order to explain the input image in an easy-to-understand manner, a pattern consisting of three parts, a triangle, a circle, and a quadrangle, is used, and each part is described with a sense of front and back. However, the input image is not limited to these, and any image may be used. Also, the input image may be either color or monochrome.

In this specification, the "characteristic value of the input image" is a value of the input image, such as luminance, saturation, hue, density, transparency, lightness, chromaticity, grayscale level (grayscale value), etc. . These feature values may be indicated for each pattern of the input image, for each part, for each area, for each pixel, or for each block divided by several pixels. Furthermore, representative values such as the average value, median value, maximum value and minimum value for each area may be used.

<Layer information>
FIG. 15 is a diagram schematically showing layer information by dividing the design pattern of FIG. 14 into layers.
In this specification, "layer information" is information that designates the sense of front and back of the pattern and parts of the input image. It is also possible to indicate only the order of the order before and after.

FIG. 15 schematically shows three parts of a triangle, a circle, and a rectangle divided into three layers (1, 2, 3), but the number of layers is limited to three. It is not a thing, and the sense of distance before and after the layer may be a continuous thing, not a discrete one.
In addition, the sense of distance in front of and behind the layer can be set so that the moire display body appears to protrude from the moire display body toward the observer when viewed from the observer side, or the moire display body appears to be behind the moire display body. can also be set.

A.
<Example of Generation of Moiré Pattern>
In the following, the case of using a stripe pattern will be taken as an example, and a method and system for generating a moire pattern according to an input image of the embodiment will be described.

<Basic pattern and change pattern>
16A and 16B are diagrams showing examples of the basic pattern of the stripe pattern used in this embodiment and the pattern with the opening/non-opening ratio changed.
The basic pattern (a) has an opening/non-opening ratio of 1.0, and the opening/non-opening ratios of (b) to (e) range from 1.9 to 9.0, respectively. It shows the changed pattern.
The moire pattern blurring degree is defined by the gradient area when the feature value is the grayscale luminance, and is 0.4 for any pattern.

<Example of input image>
FIG. 17 is a diagram showing an example of an input image in this embodiment. The input image in FIG. 17 has a different grayscale value for each figure, and the respective grayscale values are as shown in the figure. These individual grayscale values become the feature values of the input image.
Note that dashed lines in the drawing are added to make the target image easier to see.

<Selection of opening/non-opening ratio of pattern according to feature value of input image>
The procedure for generating the moire pattern is as follows: 1) first, define a region where the opening/non-opening ratio of the pattern is to be changed; set accordingly.

1) The simplest way to determine the area for changing the opening/non-opening ratio of the pattern is to determine the area according to the contour of the input image, but it is not necessarily determined by the contour of the image. , may be appropriately set according to the situation in which the moire display is used.
In this embodiment, as shown in FIG. 17, circles, triangles, and squares are defined as regions for changing the aperture/non-aperture ratio, respectively, in order to simplify the explanation.

2) When setting the opening/non-opening ratio of the pattern according to the characteristic value of the pattern, select the opening/non-opening ratio of each region based on the "appearance evaluation of moire" described later. .

<Selection of moire pattern blur degree of pattern according to feature value of input image>
The degree of blurring of the moire pattern may be constant at any position of the input image, or may be changed according to the feature value of the input image. Alternatively, the area may be divided according to the design pattern. For example, it is also possible to reduce the degree of blurring in portions where moire phase fluctuations are small and increase the degree of blurring in portions where moire phase fluctuations are large. It may be 0 in the portion where the phase fluctuation is small. On the other hand, a portion with a large phase fluctuation can be made clear if the moire pattern blur degree is within a desirable range. The following moiré pattern blurriness can be used. In other words, it can have two or more areas of a low blur area, a medium blur area, and a high blur area. In other words, it may have a low blur area, a medium blur area, and a high blur area. Alternatively, it may have any two areas of a low blur area, a medium blur area, and a high blur area.
(1) Low blur area: Moire pattern blur due to gradient area is 0 to 0.2
: Moire pattern blurring degree by gradient area is 0 to 0.05
: Moire pattern blurring degree by gradient angle is 0 to 12
(2) Middle blur area: Moire pattern blur due to gradient area is 0.2 to 0.5
: The degree of moire pattern blurring due to the gradient area is 0.05 to 0.08
: The degree of moire pattern blurring depending on the gradient angle is 12 to 25
(3) High blur area: Moire pattern blur due to gradient area is 0.5 to 0.6
: The degree of moire pattern blurring due to the gradient area is 0.08 to 1
: The degree of moire pattern blurring due to the gradient angle is 25 to 30
As a modification of the above, the overall degree of blurring can be lowered or raised while maintaining the respective ratios. Also, the moire pattern blurriness can be adjusted to have a similar appearance. Alternatively, only two of the above may be used.
In this way, the present invention can include those that can be modified and adjusted by those skilled in the art according to common technical knowledge. Therefore, it should not be construed as being limited only to the above moire pattern blurring degree.

This blur distribution may be continuous or discontinuous. If it is continuous, it is easy to visually recognize a natural wavy shape, and if it is discontinuous, it is easy to display an image with a modern impression. Also, the blur degree distribution may be associated with a moire pattern, or may form a different pattern. When associated with the moire pattern, the moire pattern is easily emphasized. When a pattern different from moire is formed, it is easy to realize a more complicated pattern.
The blur degree distribution may be implemented by numerical values, or may be implemented by classifying the blur areas as described above. The low blur area and the medium blur area may be adjacent to each other. Also, the medium-bokeh area and the high-bokeh area may be adjacent to each other. A low blur area may be surrounded by a medium blur area. This makes it easy to achieve both high definition and naturalness. Furthermore, a high blur area may be arranged around the medium blur area. This high-bokeh area can be used as a background, and easily enhances the pattern. Also, the high blur area may be surrounded by the low blur area. As a result, it is possible to provide an effect that makes it possible to feel the difference in depth between the high-bokeh area and the low-bokeh area.

When setting according to the feature values of the input image, for example, when setting the moiré pattern blurring degree to be small in dark portions of the design image and to set the moiré pattern blurring degree to be large in bright portions of the design image, the input image is an 8-bit grayscale image, When grayscale pixel values are treated as feature values, the range of moiré pattern blurring that you want to set is determined in advance, and the grayscale pixel values are normalized in the range of 0 to 255, or allocated from the minimum value to the maximum value in the image. A method of allocating by values normalized is conceivable.

<Example of output pattern after changing aperture/non-aperture ratio>
FIG. 18 is a diagram showing an output pattern example on the near side. Also, FIG. 19 is a diagram showing an example of an output pattern on the far side.
In this embodiment, the opening/non-opening ratio of the front side pattern to be output is changed according to the feature value of the input image, and the opening/non-opening ratio of the back side pattern is kept constant.

<Appearance Evaluation Method for Moire>
The aperture/non-aperture ratio selected according to the feature value of the input image can be selected by combining moiré appearance evaluation and moiré contrast evaluation under the same conditions as the situation in which the moiré display is used.
For example, select the aperture/non-aperture ratio evaluated as the brightest and the aperture/non-aperture ratio evaluated as the darkest of the moiré light-dark evaluations. and correspond to the feature values of the input image.

In addition, when the brightest opening / non-opening ratio and the darkest opening / non-opening ratio of the moiré light and dark evaluation are set as the upper limit / lower limit, the moire appearance evaluation is good (for example, ○△ × It is desirable to select the upper limit/lower limit in the range of △ when adopting the three-grade evaluation.
Furthermore, the method of fitting from the upper limit to the lower limit may be linear, exponential, or logarithmic, and may be determined with several gradations or selected arbitrarily.

It should be noted that the method of reflecting the results of moire appearance evaluation is not limited to the above, and upper and lower limits may be arbitrarily set, an intermediate value may be set, and moiré light and shade evaluation may be performed. The gradation of the part/non-aperture ratio may be determined in advance. Furthermore, only part of the appearance evaluation may be used.

<Specific example of moire appearance evaluation>
Based on the above appearance evaluation method, appearance evaluation is performed under the following requirements in this example.
Pattern type: Apply stripe pattern.
Pitch: The pitch of the pattern on the front side and the pattern on the back side shall be the same.
The opening/non-opening ratio of the pattern on the front side: 1 (1/1) to 9 (9/1).
The aperture/non-aperture ratio of the deep pattern is fixed at 1 (1/1).
Construction: Similar to the one shown in Fig. 9, patterns are printed on two sheets of transparent film and pasted on both sides of a 5 mm thick acrylic plate. The basic viewing distance is 1m. The pattern and the observer's eye level coincide.

FIG. 20 shows the results of appearance evaluation performed under the above conditions.
The evaluation was made by two observers, and the moire appearance evaluation was evaluated on a 3-level scale (bad: ×, average: △, good: ○), and the moire intensity was evaluated on a 6-level scale (the darkest case is 0, the brightest case is is expressed as a number between 5).

Regarding the input image of FIG. 17 in this embodiment, if the feature value of the input image is the grayscale level, the background has a grayscale level of 100%, and the figure has grayscale levels of 0, 45, and 75% in order from the left. .

In this example, the lower limit of the aperture/non-opening ratio is set to 1.0 (=1/1) where the appearance evaluation is △, corresponding to the grayscale level of 0% which is the darkest part, and the upper limit is set to the appearance evaluation. is 4.0 (=8/2), which is Δ.
Then the aperture/non-aperture ratio between the upper and lower limits varies linearly, with an aperture/non-aperture ratio of 1.8 at a grayscale level of 45% and an aperture of 1.8 at a grayscale level of 75%. The output pattern shown in FIG. 18 is obtained when the /non-aperture ratio is 3.0.

<Determining Phase Fluctuation Amount>
In order to express a moire image by superimposing patterns, it is necessary to match the feature value of the input image with the phase variation amount of the phase of one of the patterns. In the simplest way, if the feature value of the input image is the grayscale level, the higher the grayscale level (the more whitish the image is), the smaller the amount of phase change in the phase. ) The amount of phase variation of the phase should be increased.

In this embodiment, the phase variation corresponding to (1) grayscale level 0% (black), (2) grayscale level 50% (gray), and (3) grayscale level 100% (white) is This will be described below with reference to FIGS. 21 and 22. FIG.
The following description is based on the premise that the pattern on the near side has an opening/non-opening ratio of 1 (the ratio of openings to non-openings is 1:1).

For a gray scale level of 0%: the phase of the pattern is shifted by half a cycle (π) (non-aperture and aperture are reversed), that is, phase shift variation = π.
When the gray scale level is 50%: The phase of the pattern is shifted by 1/4 period (π/2) (corresponding to 50% of the aperture, and the ratio of the non-aperture and the aperture in the overlapping state is 3:1). ), that is, the amount of phase shift variation=π/2.
When the gray scale level is 100%: The phase of the pattern is not changed, and the non-opening portion and the opening portion are kept at 1:1, that is, the amount of phase shift variation=0.

As described above, by determining the amount of phase variation of the phase with respect to the opening according to the grayscale level of the pattern, it is possible to express light and shade in the overlapping state.
In the above example, the amount of phase variation with respect to the opening is linear, but non-linearity such as exponential/logarithmic or gradation may be set.

Moreover, the pattern on the front side or the pattern on both sides may be shifted in phase. Since the front side pattern has a large influence as a design, it is desirable to shift the phase of the back side pattern according to the feature value of the input image while keeping the front side pattern constant.

<Determination of Pitch Phase Fluctuation Amount>
When the moiré pattern A (front side) and the moiré pattern B (back side) are placed with a gap therebetween, the generated moiré image is felt stereoscopically due to the binocular parallax.
When the pitch of the pattern on the back side is larger than that of the pattern on the front side, the moiré image appears to float on the front side. looks like
The depth of the pattern (appearing further back than the pattern) and the feeling of popping out (appearing in front of the pattern) depend on the ratio of the pattern on the front side and the pattern on the back side, and the pattern installation conditions (the base material and the panel to be laminated). (thickness, refractive index, etc.).

For example, when patterns are pasted on the front and back surfaces of a 5 mm thick acrylic plate, the ratio of the pitch of the pattern on the back side to the pitch of the pattern on the front side (also called the pitch ratio) is 100%, the pitch of both patterns is ), depth is felt in the range of 95% to 99.9%, and depth is felt more in the range of 98 to 99.5%.
Also, when the range is 100.3 to 105.0%, a popping feeling is felt, and when the range is 100.3 to 102.0%, a popping feeling can be felt more. The amount by which the pitch ratio changes from 100% is referred to as the pitch phase fluctuation amount.

<Generation system for pattern that expresses moire image>
FIG. 23 is a schematic diagram of a pattern generation system SYS that develops a moire image. The generation system SYS can realize the above-described pattern generation method and method for expressing the moiré image. can be output. The generation system SYS includes an input image reading unit RD for reading input image data, an input image feature value extraction unit PK for extracting feature values from the input image data, and a layer information input for setting layer information input. It has a setting section LI, an input setting section MI for inputting and setting moire display information, and an input setting section SI for basic pattern information for inputting and setting basic pattern information.

After inputting the above information, the calculation unit CA of the generation system SYS sets the aperture/non-aperture ratio and the moire pattern blurring degree for each area of the image from the feature values of the input image as described above. It is possible to calculate the variation amount and the pitch ratio, and output the printing data of the moire pattern A (front side) and the moire pattern B (back side). Based on such printing data, the moire pattern A (front side) and the moire pattern B (back side) can be printed on a film or the like.

It should be noted that the present invention is not limited to the above-described embodiments or examples, and includes various modifications. For example, various changes are possible, such as the setting of the shape of the basic pattern, the opening/non-opening ratio, and the reflection on the patterns on the near side and the far side. In addition, the drawings used in the embodiments and examples are described in detail to explain the present invention in an easy-to-understand manner, and are not necessarily limited to the designs and the like described in the embodiments and examples.
Also, it goes without saying that various changes are possible for the setting of the phase fluctuation amount and the pitch ratio.

1: Layer, 2: Layer, 3: Layer 4: Moire display body, 5: Panel thickness, 6: Expression area

Claims (6)

In a moire display body in which a plurality of patterns consisting of openings and non-openings are formed,
The average transmittance of the opening is higher than the average transmittance of the non-opening,
a difference between the maximum transmittance of the opening and the minimum transmittance of the non-opening is 1% or more;
When a plurality of the patterns partially overlap, at least the pattern on the back side can be seen through the opening of the pattern on the front side, so that a moire image appears,
The pattern can change moire pattern blurring within the display surface,
the moire pattern blur is defined by at least one of a gradient area, a gradient area, and a gradient angle;
A moiré display body characterized by: When the pattern is formed by printing, blurring of the moire pattern is formed by adjusting at least one of a difference in halftone dot size and a difference in density of halftone dots.
A moiré display member according to claim 1, characterized in that: A gap is formed between the pattern on the front side and the pattern on the back side.
3. A moiré display member according to claim 1 or 2, characterized in that: A pattern formed on the moire display body according to any one of claims 1 to 3, wherein the moire pattern blurring degree is changed within the display surface,
A pattern characterized by A pattern generation method for generating the pattern according to claim 4,
After reading an input image, extracting characteristic values of the input image, inputting and setting layer information, inputting and setting moire display body information, and inputting and setting basic pattern information,
An aperture/non-aperture ratio for each area of the image is set from the feature values of the input image, and the phase variation amount, the pitch ratio, and the degree of moire pattern blur are calculated, and the moire image is expressed in the front side pattern and the back side pattern. output the data of the side pattern,
A pattern generation method characterized by: A pattern generation system for generating the pattern of claim 4,
An input image reading unit that reads an input image, an input image feature value extraction unit that extracts feature values of the input image, a layer information input setting unit that performs input settings for layer information, and a moiré display body information input setting. It has a moire display body information input setting unit, a basic pattern information input setting unit for performing input setting of basic pattern information, and a calculation unit,
The computing unit sets an aperture/non-aperture ratio for each area of the image from the feature values of the input image, calculates a phase variation amount, a pitch ratio, and a moire pattern blur degree, and expresses a moire image. output the data of the front side pattern and the back side pattern,
A pattern generation system characterized by:

Images