JP3383004B2 - Method and apparatus for producing hologram recording medium - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a work <br/> forming method and producing apparatus of the hologram recording medium, in particular, the hologram recording which is suitable for application to a security hologram seal for prove genuine article medium on creating a method and create device.

[0002]

2. Description of the Related Art Hologram stickers are used as a means for preventing counterfeiting of credit cards, bankbooks, cash vouchers and the like. In addition, hologram seals are used for products such as video tapes and luxury watches to prevent pirated copies from circulating. In addition, hologram stickers are also used for purposes such as decoration and sales promotion. In such a hologram sticker, a two-dimensional picture is often used as a motif instead of a three-dimensional stereoscopic image.

To make such a hologram sticker, an optical hologram photographing method in which an interference fringe is formed by using a laser beam is usually used. That is, a manuscript on which a two-dimensional pattern motif is drawn is prepared, and one of the laser beams branched into two is irradiated to this manuscript, and the reflected light and the other branched laser light are interfered with each other. The interference fringes are recorded on the photosensitive material. After the hologram master plate is created in this manner, hologram seals can be mass-produced using the master plate by a pressing method.

[0004]

However, the above-mentioned conventional optical hologram photographing method has a problem that a clear hologram image cannot be obtained. That is, since the optically formed interference fringe is sensitive to vibration, it is necessary to perform hologram imaging in an environment in which vibration is completely eliminated. However, it is difficult to completely eliminate the vibration even when shooting with a vibration-proof table with considerable accuracy.
Therefore, so-called "blur" occurs in the recorded image of the interference fringes,
A bright hologram image with contrast cannot be obtained. Further, since the oscillation wavelength of the laser light used also fluctuates, spider glass noise cannot be avoided. As described above, since there is a problem of poor reproducibility in optical hologram photographing, it is difficult to make several same original plates.

[0005] The present invention is a clear hologram image can be obtained. Moreover an object of the invention to provide a forming method and producing apparatus of good reproducibility holographic recording medium.

[0006]

[0007]

[0008]

[0009]

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

Means for Solving the Problems (1) First Invention of the Present Application
Is a method for producing a hologram recording medium in which a predetermined motif is expressed by a diffraction grating, in which a pixel pattern in which a grid line having a predetermined line width is arranged in a predetermined closed region at a predetermined pitch and a predetermined angle is used. , A first step of preparing a plurality by changing at least one of the three parameters of angle, and a predetermined motif by defining a plurality of pixels each having a predetermined pixel value at a predetermined position on a plane. The second step of preparing the motif pixel information expressing the above, and the correspondence between each pixel defined in this motif pixel information and each pixel pattern prepared in the first step are represented by the pixel value for each pixel. And a fourth step of arranging the pixel pattern at a predetermined pixel position based on this correspondence relationship. It is obtained by the.

(2) The second invention of the present application is based on the first invention.
In the method for producing a hologram recording medium according to Ming ,
In the step of, the motif pixel information for a plurality of different motifs is prepared respectively, and in the third step, for the pixels belonging to different motifs, different pixel patterns are made to correspond, and a plurality of motifs are made to overlap on the same plane. Is expressed as follows.

(3) The third invention of the present application is based on the first invention.
In the method for producing a hologram recording medium according to Ming ,
In the step, a plurality of pixel patterns having parameters close to each other are set as one group, a plurality of groups of pixel patterns are prepared, and in a second step, motif pixel information about a plurality of different motifs is prepared respectively. At this stage, with respect to pixels belonging to different motifs, pixel patterns belonging to different groups are made to correspond to each other, and a plurality of motifs are represented by overlapping on the same plane.

(4) A fourth invention of the present application is a method for producing a hologram recording medium in which a predetermined motif is expressed by a diffraction grating, in which a grid line having a predetermined line width is formed in a predetermined closed region at a predetermined pitch and a predetermined angle. The first step of preparing a plurality of pixel patterns arranged in the above by changing at least one of three parameters of line width, pitch, and angle, and a plurality of pixels each having a predetermined pixel value in M rows. A unit composed of a second stage in which motif pixel information expressing a predetermined motif by defining it on an array of N columns is prepared for each of a plurality of different motifs, and sub-pixels arranged in m rows and n columns. A third step of defining a sub-pixel array and preparing sub-pixel configuration information that defines which motif pixel is to be arranged at each sub-pixel position in this unit sub-pixel array. The fourth step of defining the correspondence between each pixel defined in the pixel information and each pixel pattern prepared in the first step by referring to the pixel value of each pixel, and the unit sub-pixel array Self M row N
By arranging them in columns, a sub-pixel array of (m × M) rows (n × N) columns is defined, and based on the correspondence defined in the fourth step, each unit sub-pixel array is arranged for each motif. The fifth step of extracting the corresponding pixel pattern and arranging the extracted pixel pattern at a predetermined sub-pixel position based on the sub-pixel configuration information prepared in the third step. is there.

(5) A fifth invention of the present application is a method for producing a hologram recording medium in which a predetermined motif is expressed by a diffraction grating, wherein a grid line having a predetermined line width is formed in a predetermined closed region at a predetermined pitch and a predetermined angle. The first step of preparing a plurality of pixel patterns arranged in the above by changing at least one of three parameters of line width, pitch, and angle, and a plurality of pixels each having a predetermined pixel value in M rows. A unit composed of a second stage in which motif pixel information expressing a predetermined motif by defining it on an array of N columns is prepared for each of a plurality of different motifs, and sub-pixels arranged in m rows and n columns. A third step of defining a sub-pixel array and preparing sub-pixel configuration information that defines which motif pixel is to be arranged at each sub-pixel position in this unit sub-pixel array. The fourth step of defining the correspondence between each pixel defined in the pixel information and each pixel pattern prepared in the first step by referring to the pixel value of each pixel, and the unit sub-pixel array Self (M /
m) rows (N / n) columns to define a sub-pixel array of M rows and N columns, and based on the correspondence defined in the fourth step, each sub-pixel array for each motif A fifth step of extracting a corresponding pixel pattern, selecting a part of the extracted pixel pattern based on the sub-pixel configuration information prepared in the third step, and disposing the selected pixel pattern at a predetermined sub-pixel position.
The steps and are to be performed.

(6) The sixth invention of the present application is the above-mentioned first to third inventions.
In the method for producing a hologram recording medium according to any one of the fifth invention, the area ratios of the total occupied area as a pixel and the closed area in which the lattice line is arranged in the entire occupied area are respectively Prepare multiple different pixel patterns,
A pixel pattern having an area ratio corresponding to the pixel value of the pixel is associated with each pixel position to express a motif having gradation.

(7) A seventh invention of the present application is, in an apparatus for producing a hologram recording medium in which a predetermined motif is expressed by a diffraction grating, in a predetermined closed region at a predetermined pitch and a predetermined angle with respect to a grid line having a predetermined line width. A means for holding a plurality of pixel pattern files prepared by changing at least one of three parameters of the line width, pitch, and angle of the pixel pattern arranged in, and a plurality of pixels each having a predetermined pixel value. Means for inputting a motif pixel information file expressing a predetermined motif by defining at a predetermined position on the plane, each pixel defined in this motif pixel information file, and each prepared in the pixel pattern file. The correspondence with the pixel pattern,
Means for creating a correspondence relationship information file defined by referring to pixel values for each pixel, and means for creating image data in which pixel patterns are arranged at predetermined pixel positions based on the correspondence relationship information file, m rows and n columns
For the unit subpixel array that consists of arrayed subpixels
Which sub-pixel position in this unit sub-pixel array
Sub-pixel configuration information file that defines whether to arrange the pixels
And a means for creating image data
Of the pixel pattern based on the sub-pixel configuration information file
The arrangement processing is performed.

[0022]

[0023]

[Operation] The features of the hologram recording medium according to the present invention are:
The point is that a hologram pattern is recorded by arranging pixels on which a diffraction grating is formed in a plane. By adopting the method of arranging pixels in this way, an arbitrary motif image can be created by a computer. The image pattern of the diffraction grating formed in each pixel can also be created by a computer, and all the operations up to the final hologram pattern creation can be processed by the computer. In short, according to the present invention, it is possible to create a hologram recording medium by computer-generated diffraction grating pattern data without performing optical imaging. If the diffraction grating pattern data created once is saved and the hologram recording medium is created again based on this data, almost the same recording medium can be obtained and almost complete reproducibility can be obtained. . Further, since it is not necessary to perform optical photographing, a clear hologram image can be obtained.

As described above, according to the present invention, since a desired motif is expressed by arranging the pixels on which the diffraction grating is formed, various special effects can be utilized. For example, a diffraction grating having different optical characteristics can be created by changing the line width, pitch, and arrangement angle of the grating lines that form the diffraction grating. Therefore, various special effects can be expressed by preparing a plurality of such pixels having different optical characteristics and appropriately using them. Specifically, if the first pixels are arranged side by side for the first motif and the second pixels are arranged side by side for the second motif, two motifs are recorded on the same plane. In addition, these two motifs can be observed separately due to the difference in optical characteristics.

In general, the word "hologram" is used as a word indicating an image obtained by interference fringes. From such a meaning, the image formed on the recording medium of the present invention is It should be called "pseudo hologram" or "diffraction grating pattern" instead of "hologram". However, since a recording medium used as a seal for preventing forgery is generally called a "hologram seal", the "diffraction grating pattern" formed on the recording medium is also referred to as "hologram seal" in this specification. We will use the term "hologram".

[0026]

The present invention will be described below based on several illustrated embodiments.

§1. Basic Example A feature of the hologram recording medium according to the present invention is that a motif composed of a plurality of pixels is represented as a hologram on the medium. Here, a method of expressing a relatively simple motif (indicating an English letter "A") as shown in FIG. 1 (a) on a hologram recording medium according to the present invention will be described. The method for producing a hologram recording medium according to the present invention is premised on being carried out by using a computer, and each processing described below is executed by using the computer.

First, as the image data corresponding to the motif shown in FIG. 1A, motif pixel information as shown in FIG. 1B is prepared. In the example shown here, pixels are arranged in 7 rows and 7 columns, and each pixel has a pixel value of either "0" or "1", which is information indicating a so-called binary image. Such information is general image data called so-called "raster image data", and can be created by an ordinary drawing device. Alternatively,
Such motif pixel information may be prepared by capturing a design image drawn on the paper surface with a scanner device.

Subsequently, as shown in FIG. 2, a pixel pattern is defined in which lattice lines having a predetermined line width d are arranged in a predetermined closed region V at a predetermined pitch p and a predetermined angle θ. Here, the closed region V is a region that constitutes one pixel and is actually a very small element. In other words, it has a size corresponding to each pixel in the 7 × 7 array shown in FIGS. 1 (a) and 1 (b). In this embodiment, as the closed region V,
A rectangle with a size of 50 μm × 45 μm in length × width is used. Further, the line width d and the pitch p of the lattice lines L arranged in the closed region V also have minute dimensions according to the wavelength of light. In this embodiment, the line width d = 0.6 μ.
m, pitch p = 1.2 μm. In short, the grid line L
Is a line width d and a pitch p that function as a diffraction grating
Must be placed in. Arrangement angle θ of the grid line L
Is an angle set with respect to a predetermined reference axis. In this specification, an XY coordinate system in which the X axis and the Y axis are taken in the directions shown in the figure is defined, and the arrangement angle θ of the grid line L is represented with the X axis as the reference axis. Such a pixel pattern is also prepared as image data on the computer. The image data of this pixel pattern is
It may be prepared as "raster image data" (in this case, each pixel forming the motif is represented by a smaller pixel), or
You may prepare as "vector image data" which defined the outline of the grid line L by designating the coordinate value of four vertices of the quadrangle which comprises the grid line L. The latter is preferable in order to reduce the amount of data.

Next, based on each pixel value in the motif pixel information as shown in FIG. 1 (b), a pixel pattern as shown in FIG. 2 is associated with a predetermined pixel, and a pixel corresponding to each pixel position is provided. Perform the process of placing the pattern. Specifically, in the motif pixel information shown in FIG. 1B, the pixel pattern of FIG. 2 is associated with each pixel having a pixel value of “1”. No pixel pattern is associated with a pixel having a pixel value of “0”. Pixel patterns are arranged at the pixel positions thus associated. So to speak, if the array shown in Fig. 1 (b) is compared to a wall, the work of sticking tiles as shown in Fig. 2 to each area drawn as "1" in this wall will be performed. . As a result,
An image pattern as shown in is obtained. This image pattern is the pattern finally recorded on the hologram recording medium. The motif shown in Fig. 1 (a) is expressed as it is, but each pixel is composed of a diffraction grating,
The visual effect as a hologram will be obtained.

Of course, the process of pasting pixel patterns as shown in FIG. 2 as "tiles" is performed as image processing in the computer. This process can be
As shown in FIG. 4, when the coordinate origin O is set at the lower right position of the image corresponding to the entire motif, the offset amounts a and b based on the pixel positions to be pasted are calculated and the pasted as image data. It suffices to perform processing. As a result of such arithmetic processing, image data showing a pattern as shown in FIG. 3 is obtained, and therefore, based on this image data,
By physically outputting the pattern shown in FIG. 3 on a film or the like, a desired hologram recording medium can be created. In the present embodiment, as will be described later, image data created by a computer is given to an electron beam drawing apparatus, an electron beam is used to draw a pattern as shown in FIG. 3 on an original plate, and this original plate is used to press a pattern. We are trying to mass produce hologram stickers by the method.

§2. Implementation using multiple pixel patterns
Example In the above-described basic example, the hologram recording medium was created using only the pixel patterns shown in FIG. 2, but here, a method of using a plurality of types of pixel patterns will be described. As shown in FIG. 2, this pixel pattern has a grid line L.
Is a pattern specified by three parameters, namely, the line width d, the pitch p, and the arrangement angle θ. Different patterns will be obtained by changing at least one of these three parameters. More specifically, when the line width d and the pitch p are changed, the color observed from the pattern changes, and when the arrangement angle θ is changed, the observable direction of the pattern changes. Therefore, by preparing a plurality of types of pixel patterns with different parameters and using these differently, it is possible to form an effective hologram image rich in variations.

A concrete example is as follows. For example, five types of pixel patterns P1 to P as shown in FIG.
Prepare 5. Among these three parameters, these pixel patterns have the same line width d and pitch p, but different angles θ. That is, as shown in the figure, the angles θ = 30 °, 60 °, 90 °, 120 °, 15
Five types of 0 ° are prepared (the actual grid line has a predetermined width, but for convenience of illustration, the grid line is shown as a simple line in the following figures).

When using a plurality of pixel patterns in this way, it is necessary to determine which pixel pattern is to be arranged at which pixel position. Therefore, the correspondence information as shown in FIG. 6 (a) is prepared. This correspondence information includes five types of pixel patterns P shown in FIG. 5 for each pixel whose pixel value is “1” in the motif pixel information shown in FIG. 1 (b).
It is information indicating that any one of 1 to P5 is associated. Regarding a pixel having a pixel value of “0”, no pixel pattern is associated (or an empty pixel pattern P0 in which no grid line is formed is defined, and the pixel value is “0”). The pixels having “” may correspond to this empty pixel pattern P0). This correspondence information is, so to speak, information that indicates "which of the five types of tiles is to be attached to which position". Therefore, if such correspondence information is created, mechanical pasting work by a computer becomes possible. In the example of FIG. 6A, the pixel pattern names P1 to P are used as the correspondence information.
Although the information for specifying 5 is used, as in the example of FIG. 6 (b), the value of the angle θ of the grid line (that is, the value of the parameter)
You may use the information which specifies.

Thus, the hologram image formed by using the five types of pixel patterns becomes more varied. When a plurality of pixel patterns with different parameters of angle θ are used as in this example, the angle at which light is observed at the left and right parts of the motif shown in FIG. If you hold it in your hand and observe it while tilting it, you can get the effect that light flows left and right. By using a plurality of pixel patterns having different parameters such as the line width d or the pitch p, it is possible to obtain the effect that the colors observed on the left and right are different. Of course 2
It is also possible to prepare various pixel patterns in which one or more parameters are changed.

By the way, in order to prepare the correspondence information as shown in FIG. 6, it is necessary to give some instructions to the computer. The most basic way to give instructions is to display a motif as shown in Fig. 1 (a) on the display, and select P1 to P5 (or 30 ° to 150 °) for each pixel that constitutes this motif. ) Is one of the methods to specify. By creating the correspondence information by such a method, it is possible to define a completely arbitrary correspondence. However, the task of instructing the corresponding pixel pattern one by one for each pixel is a task that requires considerable effort and time. Therefore, in this embodiment, a computer program has a function capable of creating correspondence information by a simple operation. Looking at the correspondence information shown in FIG. 6 (b),
A certain regularity can be discovered. That is, the pixel in the second column is θ
A pixel pattern of θ = 150 ° is associated with the pixel in the sixth column of = 30 °, and the value of θ increases by 30 ° from the second column to the sixth column. Such a method of gradually changing the parameter value is generally called a “gradation”, and in this example, gradation is applied in the horizontal direction.

The correspondence information for applying such gradation can be created by the following simple operation. That is, as shown in FIG. 7, after displaying the theme motif on the display screen, an instruction to create correspondence information for applying a gradation may be given. Specifically, while giving an instruction to apply horizontal gradation,
Initial value θ = 3 by specifying the pixel position of the second row with a mouse
The final value θ = 150 ° may be input by inputting 0 °, specifying the pixel position of the sixth column with a mouse or the like. If such information is given, the value of θ can be automatically set by performing linear interpolation for the pixels in the third to fifth columns. Therefore, the operator does not need to specify the corresponding pixel pattern for each pixel. Of course, it is possible to make the setting in which the gradation is applied in the vertical direction as well. Further, although the gradation regarding the angle θ is applied here, the gradation regarding the line width d and the pitch p of the lattice lines can be set in the same manner.

The example shown is for a relatively small 7 × 7 pixel array, but in reality, a motif for a larger pixel array is used. Therefore, if only the initial value and the final value are specified, the number of pixel pattern variations may become enormous. For example, if 121 pixels exist from the pixel for which the initial value is specified to the pixel for which the final value is specified, in the above setting, the value of θ changes from the right pixel to the left pixel. 30 °, 31 °, 32 °, ..., 149 °, 150 °
As the number of pixel patterns increases, 121 pixel patterns are required. In such a case, the step value may be designated in addition to the initial value and the final value. For example, if 30 ° is specified as the step value, the variation of the value of θ is 3
Since it is limited to five kinds of 0 °, 60 °, 90 °, 120 °, and 150 °, it is sufficient to prepare five kinds of pixel patterns as shown in FIG.

The motif pixel information shown in FIG. 1 (b) is binary image information in which each pixel value is either "0" or "1", but an image having gradation is used as a motif. When used as, it is also possible to determine the corresponding pixel pattern based on each pixel value. For example, in Figure 1.
Consider a case where motif pixel information as shown in FIG. 8 is given instead of the motif pixel information shown in (b). Here, each pixel value takes any value from 0 to 255. Here, each pixel having such a pixel value is shown in FIG.
It is assumed that the following rule is defined to associate with the five types of pixel patterns P1 to P5 shown in FIG.

Pixels having a pixel value of 50 or less: Pixels having unassociated pixel values 51 to 100: Pixels having pixel values 101 to 150 associated with P1: Pixels having pixel values 151 to 200 associated with P2: Pixels associated with P3 Pixels having values 201 to 250: P4 having pixel values 251 or more: pixels having pixel values 251 or more: P5 having such a rule defined are shown in FIG. 6 based on motif pixel information as shown in FIG. It becomes possible to automatically set such correspondence information.

§3. Example in which a plurality of motifs are expressed Next, an example in which a plurality of motifs are overlapped and expressed on the same plane will be described. For example, suppose that a motif A shown in FIG. 9 (a) and a motif B shown in FIG. 9 (b) are given, and that these two motifs are redundantly expressed on the same plane. In this case, two pixel patterns P1 and P2 as shown in FIG. 10 are prepared. Here, in the pixel patterns P1 and P2, the line width d and the pitch p of the lattice lines are the same, but the angle θ is 45 ° in P1, whereas P
At 2, it is 90 °. The pixels belonging to the motif A are associated with the pixel pattern P1 and the pixels belonging to the motif B are associated with the pixel pattern P2.
Correspondence relationship information is created so as to correspond to each other. Specifically, as shown in FIG. 11A, the correspondence information R1 in which the pixel pattern P1 is associated with the pixel position having the pixel value “1” in the motif A is created as shown in FIG.
The correspondence relationship information R2 in which the pixel pattern P2 is associated with the pixel position having the pixel value “1” in the motif B is shown in FIG.
Create it as shown in (b). Then, based on these two pieces of correspondence information R1 and R2, the pixel patterns P1 and P
By performing the sticking process of No. 2, a hologram recording medium having a diffraction grating pattern as shown in FIG. 12 is created.
Here, since the motif A is expressed by a diffraction grating of θ = 45 ° and the motif B is expressed by a diffraction grating of θ = 90 °, the observable angles of both motifs are different, and they are distinguished and observed as separate motifs. To be done. According to such a method, a plurality of motifs (three or more are possible) can be overlapped and expressed on the same plane.

It is also possible to use a plurality of pixel patterns for the same motif. In this case, in order to distinguish it from other motifs, it is preferable to define a plurality of pixel patterns having similar parameters as one group. For example, the six types of pixel patterns shown in FIG. 13 include three pixel patterns P11, P12, P13 belonging to the first group and three pixel patterns P21, P22, P23 belonging to the second group.
It is composed by. These pixel patterns have the same line width d and pitch p, but have different angles θ. However, the angle θ of the pixel patterns belonging to the first group is 40 °, 45 °, 50 °.
And the angles θ of the pixel patterns belonging to the second group are also close to 85 °, 90 °, and 95 °. Six kinds of pixel patterns like this are prepared. For example, for pixels belonging to the motif A,
Pixel patterns belonging to the first group are associated with each other, and pixels belonging to the motif B are associated with pixel patterns belonging to the second group. Specifically, for motif A shown in FIG. 9 (a), FIG.
The correspondence information R1 as shown in FIG. 9 is created, and the correspondence information R2 as shown in FIG. 14 (b) is created for the motif B shown in FIG. 9 (b). The pattern on the hologram recording medium created using such correspondence information is almost the same as that shown in FIG. 12, but it is more effective because the lattice angle values are slightly dispersed within the same motif. Can be expressed. For motif A, θ
= 45 ° as the center and 5 ° at a time,
Since the motif B is dispersed by 5 ° around θ = 90 °, pattern recognition for distinguishing and understanding the motifs A and B is sufficiently possible.

[0043]§4. Multiple motifs with overlapping pixels
Example of expressing In the above example, the two motifs A and B shown in FIG.
, The pixels with the pixel value "1" never overlap.
Therefore, as shown in FIG. 12, pixels of both motifs were mixed.
Expression becomes possible. However, an image with a pixel value of "1"
For multiple motifs with overlapping elements, see the example above.
Such a method cannot be applied as it is. for example
For example, two motifs A as shown in FIGS. 15 (a) and 15 (b),
For B, apply the above-mentioned method as it is and proceed with the work.
Try. Here, the motif A is shown in FIG.
The pattern P1 is made to correspond, and the motif B is shown in FIG.
Let it correspond to the pattern P2 shown in FIG. Do
And motif A corresponds to the one shown in Fig. 16 (a).
Relationship information R1 is created, and for motif B, FIG.
Correspondence information R2 as shown in (b) is created. Toko
Based on these two correspondence information R1 and R2,
When actually trying to paste the pixel pattern,
Pixel pattern collision for pixels surrounded by solid lines in FIG.
Occurs. For example, look at the pixel in the second row and third column
According to the correspondence information R1, the pixel pattern P1 is pasted.
Although it is shown that the correspondence information R2
This indicates that the pixel pattern P2 is to be attached. This
Therefore, which pixel pattern should you actually paste?
I can't judge how.

In order to solve such a problem, the present invention introduces the following concept of subpixel. Now, consider a case where a predetermined motif is expressed by a pixel array of M rows and N columns (7 rows and 7 columns in this example) as shown in FIG. In this case, as shown on the right side of the drawing, what is defined as a "unit sub-pixel array" that is composed of sub-pixels arranged in m rows and n columns (2 rows and 2 columns in this example). In this example, this "unit subpixel array" has a size corresponding to one pixel. More specifically, referring to FIG.
In the example shown in (1), one pixel is divided into four to form a sub-pixel, and the four sub-pixels form one "unit sub-pixel array". Subsequently, sub-pixel configuration information that defines which motif pixel is to be arranged at each sub-pixel position in this "unit sub-pixel array" is created. For example, when the motif A and the motif B are displayed in an overlapping manner, either the pixel of the motif A or the pixel of the motif B is arranged at each sub-pixel position. Therefore, sub-pixel configuration information as shown in FIG. 18 is created to define which motif pixel is to be arranged at each sub-pixel position. FIG.
In the above example, it is defined that the pixels of the motif A are arranged at the upper left and lower right subpixel positions, and the pixels of the motif B are arranged at the lower left and upper right subpixel positions, respectively. Although any definition may be made, it is preferable to arrange pixels of the same motif in diagonal positions in this way in order to display both motifs equally.

Next, as shown in FIG. 19A, the "unit subpixel array" itself defined as shown in FIG.
Arrange in columns. As described above, in this example, since the “unit subpixel array” has a size corresponding to one pixel, the array of the “unit subpixel array” shown in FIG. It becomes the same as the array of pixels shown on the left side of 17.
When the array of "unit subpixel array" shown in FIG. 19A is viewed as an array of "subpixel", (m × M) rows (n × N) as shown in FIG. 19B. It becomes an array of columns (14 rows and 14 columns in this example).

By the way, as shown in FIGS. 16 (a) and 16 (b), the correspondence information R1 and R2 can be obtained for the two motifs A and B, respectively. A predetermined pixel pattern can be extracted from the “sub-pixel array”. FIG. 20 shows a pixel pattern extracted in this way. Pixel patterns P1 or P2 are extracted in some of the 49 sets of "unit subpixel arrays", and both are extracted in some of them. Then, based on the sub-pixel configuration information defined in FIG. 18, the extracted pixel pattern is
It is arranged at a predetermined sub-pixel position. That is, the pixel pattern P1 for the motif A is arranged at the upper left and lower right subpixel positions in the “unit subpixel array (shown by the solid line in FIG. 21)” as shown in FIG. .
The pixel pattern P2 for the motif B is shown in FIG.
As shown in 1 (b), they are arranged at the lower left and upper right subpixel positions in the "unit subpixel array". If such an arrangement is duplicated on the same plane, a pattern as shown in FIG. 22 is obtained, and this becomes a pattern actually recorded on the hologram recording medium.

In the pattern shown in FIG. 22, the motif A and the motif B are redundantly expressed. Moreover, since the sub-pixel expressing the motif A and the sub-pixel expressing the motif B have different grid line formation angles, the motif A can be recognized when observed from one direction (see FIG. 21 (a)). Pattern can be recognized), and motif B can be recognized when observed from another direction (Fig. 21).
(A pattern like (b) can be recognized). By using such a method, it is possible to represent a plurality of motifs with overlapping pixels on the same plane in an overlapping manner. Since the two motifs A and B shown in FIG. 15 are both low-resolution images,
The patterns shown in 1 (a) and (b) are considerably distorted compared to the original motif, but in reality, since the image with higher resolution is used as the motif, Distortion is hardly a problem.

In this method, it is possible to represent three or more motifs in an overlapping manner. For example, in FIG.
By defining the sub-pixel configuration information as shown in (a), the four motifs A, B, C and D can be expressed in duplicate on the same plane. Further, if the sub-pixel configuration information as shown in FIG. 23 (b) is defined, the three motifs A, B, and C can be expressed in duplicate on the same plane. However, in this case,
The three motifs A, B and C are not equal, but motif C
Is twice as high as that of motifs A and B. As an irregular example, it is also possible to define sub-pixel configuration information as shown in FIG. 23 (c). Here, the display “A + C” means that either one of the pixels A or C is displayed here, and the motif A and the motif C are complementary patterns (for example, as shown in FIG. 9). The definition method is based on the premise that patterns such as motifs A and B are such that pixel positions having a pixel value “1” do not overlap). When the three motifs A, B, and C are equally expressed in duplicate, the sub-pixel configuration information as shown in FIG. 24 (a) or (b) may be defined. In this case, the “unit subpixel array” is an array of 3 rows and 3 columns.

Here, for the purpose of summary, a general correspondence relationship between each pixel and each sub-pixel when the above-described method is used will be described. Now, as shown in FIG. 25, the motif A is expressed by a pixel array of M rows and N columns, and individual pixels are named A11, A12, ... As shown, consider a case where the motif B is represented by a pixel array of M rows and N columns, and individual pixels are named B11, B12, .... In this case, as shown in FIG. 27, a “unit sub-pixel array” of M rows and N columns can be defined, which is (m × M) rows (n ×
It can also be referred to as a subpixel array of N) columns. At this time,
The correspondence between the individual pixels shown in FIGS. 25 and 26 and the individual sub-pixels shown in FIG. 27 is as shown in the figure (see the names given to the individual pixels). Here, the upper left subpixel and the lower right subpixel in one "unit subpixel array" correspond to exactly the same pixel, and the lower left subpixel and the upper right subpixel also correspond to exactly the same pixel (for example, , Paying attention to the "unit sub-pixel array" in the first row and first column in FIG.
The same pixel A11 corresponds to the upper left subpixel and the lower right subpixel, and the same pixel B11 corresponds to the lower left subpixel and the upper right subpixel).

On the other hand, the modified example described below shows a method of arranging completely different pixels in each of the sub-pixels. In this modification, instead of the "unit subpixel array" shown in FIG. 27, the "unit subpixel array" shown in FIG.
Is used. In each case, the area shown by the solid line is the "unit sub-pixel array", but the sizes are different in both areas. That is, in the example of FIG. 27, since the “unit subpixel array” having the same size as one pixel of the motif is defined, the subpixel has a size of ¼ of one pixel of the motif. On the other hand, in the example of FIG. 28, since the “unit subpixel array” having the size of four pixels of the motif is defined, the subpixel has the same size as one pixel of the motif. After all, FIG.
In the above example, in order to show the entire motif, an array of “unit subpixel array” in which the “unit subpixel array” itself is arranged in (M / m) rows (N / n) columns is defined. When viewed as an array of sub-pixels, this array is an array of M rows and N columns.

Here, the "unit sub-pixel array Z (the periphery is shown by hatching)" in the first row and first column in FIG.
Let us consider what kind of pixel pattern is to be embedded. Regarding the motif A, as can be seen by referring to FIG. 25, pixels A11, A12, A2
A pixel pattern corresponding to 1, A22 is extracted as a paste candidate. On the other hand, regarding the motif B, as can be seen by referring to FIG. 26, the pixels B11, B12, B2
A pixel pattern corresponding to 1, B22 is extracted as a paste candidate. Therefore, based on the sub-pixel configuration information shown in the lower part of FIG. 28, only a part of the extracted pixel pattern is selected and arranged at a predetermined sub-pixel position. Specifically, for the motif A, only the pixels A11, A22 at the upper left and lower right positions of the extracted pixels A11, A12, A21, A22 are selected, and for the motif B, the extracted pixel B11 is selected. , B
Only the pixels B12 and B21 at the lower left and upper right positions of 12, B21 and B22 are selected. Thus, as shown in the "unit sub-pixel array Z" of FIG. 28, the pixels A11, B12, B21, A
Pixel patterns for four of 22 will be pasted. Here, as can be seen by observing the entire arrangement of the “unit subpixel arrangement” shown in FIG. 28, one of two pixels forming the original motif A and motif B is thinned out. . Since the motif actually used is an image with a fairly high resolution, there is no particular problem even if such thinning is performed.

In the method shown in FIG. 27, the pixels are not thinned out, but the size of the sub-pixel becomes smaller than the size of the pixel of the motif, whereas in the method shown in FIG. The size of is the same as the size of the pixel of the motif, but the pixels are thinned out, and both have advantages and disadvantages. Therefore, any suitable method may be adopted in consideration of the pattern of the motif to be actually used, the resolution, and the like.

The shape of the pixel or sub-pixel is rectangular in the above embodiments, but FIG.
Square shape as shown in (a) (for example, 50 μm ×
A size of 50 μm) or a circular shape as shown in FIG. 29 (b) may be used. However, in terms of increasing the formation density of the diffraction grating, it is preferable to use rectangular pixels (rectangular or square) rather than circular pixels.

[0054]§5. Expressing gradational motifs
Example The explanation so far is basically a binary image without gradation.
And the processing when a motif is given
However, the present invention is also suitable for motifs with gradation.
It can be used. When expressing a motif with gradation
Is a plurality of pixel patterns as shown in FIG.
You should prepare. Here, the area indicated by the solid line is the pixel
Is the total occupied area V, and the area indicated by the broken line
A closed region W in which a grid line is arranged in the existing region V
Is. The five pixel patterns shown in FIG. 30 are all occupied areas.
The area ratio of the closed area W to the area V is 100%,
50%, 30%, 10%, 5%,
It can be said that the pixel patterns have different density values. Originally
Pixel value (density value) of each pixel that constitutes the changed motif
The pixel patterns with different density values are used according to
By doing so, it is possible to express motifs with gradation.
become.

§6. Specific Device Configuration Example Lastly, FIG. 31 shows a specific device configuration example for implementing the above-described hologram recording medium producing method.
The basic components of this device are the workstation 1
0, a data format conversion device 20, an electron beam drawing device 30, and a pressing device 40. The workstation 10 is a computer equipped with a program for performing the above-described various arithmetic processes, and has input devices such as a keyboard and a mouse, output devices such as a display and a printer, and external devices such as a floppy disk drive device and a hard disk drive device. It has a memory device and the like. Here, a state is shown in which motif pixel information files for three motifs A, B, and C are supplied to the workstation 10 by the floppy disks 1, 2, and 3, respectively. As described above, the motif pixel information (raster image data) may be created by another drawing device or the like and input to the workstation 10. Alternatively, the design image drawn on the paper may be processed by the scanner device. The data may be input to the station 10, or may be created by the workstation 10 itself by using the drawing software installed in the workstation 10.

Subsequently, the workstation 10 is used to create correspondence information based on the input motif pixel information, and this is stored as a correspondence information file 11. Further, the sub-pixel configuration information is defined, this is stored as the sub-pixel configuration information file 12, further, necessary pixel patterns are created in the required types, and this is stored as the pixel pattern file 13. An operator can prepare these files by interactively entering instructions into the workstation 10. Once you have these files, workstation 10
While searching the correspondence relationship information file 11 and the sub-pixel configuration information file 12, the pixel pattern file 13
A predetermined pixel pattern therein is pasted at a predetermined pixel position, and hologram pattern data is output.

This hologram pattern data is given to the data format conversion device 20. The data format conversion device 20 is a device having a function of converting the hologram pattern data output from the workstation 10 into a format required by the electron beam drawing device 30. The format-converted data is given to the electron beam drawing device 30, and the hologram pattern is output as a physical pattern on the hologram master 4. The pressing device 40 is a device that presses a hologram pattern on a film using the hologram original plate 4, and the hologram seal 5 is mass-produced.

In the pixel pattern shown in FIG. 2,
Each grid line L has an arbitrary square shape,
If a general device commercially available for photomask production is used as the electron beam drawing device 30, a parallelogrammatic lattice line L whose opposite sides are parallel to the X axis or the Y axis is used. Is preferred. For example, the grid line L
When the arrangement angle θ is −45 ° ≦ θ ≦ 45 °, a parallelogrammatic grid line L whose short side is parallel to the Y axis is used and the arrangement angle of the grid line L is as shown in FIG. When θ is θ> 45 ° or θ <−45 °, as shown in FIG.
It is preferable to use parallelogrammatic grid lines L whose short sides are parallel to the X axis. As described above, when the parallelogram whose opposite sides are parallel to the X axis or the Y axis is used, the drawing efficiency in the electron beam drawing apparatus for making a photomask is improved.

[0059]

As described above, according to the method for producing a hologram recording medium of the present invention, the hologram pattern is recorded by arranging the pixels on which the diffraction grating is formed in a plane. A hologram image with good properties can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of pattern and pixel information used as a motif of a hologram recording medium according to the present invention.

FIG. 2 is a diagram showing an example of a pixel pattern used in the hologram recording medium according to the present invention.

FIG. 3 is a diagram showing a hologram recording medium created using the motif shown in FIG. 1 and the pixel pattern shown in FIG.

4 is a diagram showing a concept of a pasting process for producing the hologram recording medium shown in FIG.

FIG. 5 is a diagram showing an example of a plurality of pixel patterns used in the hologram recording medium according to the present invention.

6 is a diagram showing correspondence relationship information that defines a correspondence relationship between the motif shown in FIG. 1 and the pixel pattern shown in FIG.

FIG. 7 is a diagram showing an example of creating the correspondence information shown in FIG. 6;

FIG. 8 is a diagram showing an example of pixel information about a motif having gradation.

FIG. 9 is a diagram showing an example of two motifs that are redundantly recorded on the hologram recording medium according to the present invention.

FIG. 10 is a diagram showing an example of a pixel pattern used for each of the two motifs shown in FIG.

11 is a diagram showing correspondence relationship information defining a correspondence relationship between the two motifs shown in FIG. 9 and the two pixel patterns shown in FIG.

12 is a diagram showing two motifs shown in FIG. 9, two pixel patterns shown in FIG. 10, and correspondence information shown in FIG.
It is a figure which shows the hologram recording medium created using.

13 is a diagram showing an example of pixel patterns belonging to two groups used respectively for the two motifs shown in FIG.

14 is a diagram showing correspondence relationship information defining a correspondence relationship between the two motifs shown in FIG. 9 and the two pixel patterns shown in FIG. 13.

FIG. 15 is a diagram showing another example of two motifs that are redundantly recorded in the hologram recording medium according to the present invention.

16 is a diagram showing correspondence relationship information defining a correspondence relationship between the two motifs shown in FIG. 15 and the two pixel patterns shown in FIG.

FIG. 17 is a diagram illustrating the concept of a “unit subpixel array” used in the present invention.

18 is a diagram showing an example of sub-pixel configuration information defined for the "unit sub-pixel array" shown in FIG.

FIG. 19 is a diagram showing an array regarding the “unit subpixel array” shown in FIG. 17 and a subpixel array corresponding to this array.

FIG. 20 is a diagram showing a pixel pattern extracted for each element of the array of “unit subpixel array” shown in FIG. 19;

FIG. 21 is a diagram showing a state in which the pixel pattern shown in FIG. 20 is arranged in each sub-pixel.

22 is a diagram showing a hologram recording medium created by the arrangement shown in FIG.

FIG. 23 is a diagram showing another configuration example of sub-pixel configuration information used in the present invention.

[Fig. 24] Fig. 24 is a diagram illustrating a configuration example of sub-pixel configuration information suitable for the case where three motifs are redundantly expressed.

25 is a diagram showing a pixel arrangement for motif A. FIG.

26 is a diagram showing a pixel arrangement for motif B. FIG.

FIG. 27 is a diagram showing an example in which the motif A shown in FIG. 25 and the motif B shown in FIG. 26 are overlappingly expressed by using subpixels.

FIG. 28 is a diagram showing another example in which the motif A shown in FIG. 25 and the motif B shown in FIG. 26 are overlappingly expressed using subpixels.

FIG. 29 is a diagram showing various shapes of pixels that can be used in the hologram recording medium according to the present invention.

FIG. 30 is a diagram showing a pixel pattern used when expressing a motif having gradation according to the present invention.

FIG. 31 is a block diagram showing an example of an apparatus configuration for carrying out the method for producing a hologram recording medium according to the present invention.

FIG. 32 is a diagram showing a first example of a pixel pattern suitable for drawing a lattice line using an electron beam drawing device.

FIG. 33 is a diagram showing a second example of a pixel pattern suitable for drawing a lattice line using an electron beam drawing device.

[Explanation of symbols]

1, 2, 3 ... Floppy disk 4 ... Hologram original 5 ... Hologram sticker 10 ... workstation 11 ... Correspondence information file 12 ... Sub-pixel configuration information file 13 ... Pixel pattern file 20 ... Data format conversion device 30 ... Electron beam drawing device 40 ... Press machine A, B ... Motif L ... Lattice line P1 to P5, P11 to P23 ... Pixel pattern R1, R2 ... Correspondence information V: Closed area where grid lines are placed W: Total occupied area as pixels X, Y ... Coordinate axes Z ... Unit sub-pixel array d ... Line width of grid line p ... Pitch of grid lines θ: Arrangement angle of grid lines

Claims (7)

(57) [Claims] 1. A method for producing a hologram recording medium in which a predetermined motif is expressed by a diffraction grating, comprising a pixel pattern in which a grid line having a predetermined line width is arranged in a predetermined closed region at a predetermined pitch and a predetermined angle. , A first step of preparing a plurality by changing at least one of the three parameters of line width, pitch, and angle, and defining a plurality of pixels each having a predetermined pixel value at a predetermined position on the plane. A second step of preparing motif pixel information expressing a predetermined motif by the above, and a correspondence relationship between each pixel defined in the motif pixel information and each pixel pattern prepared in the first step, A third step defined by referring to a pixel value for each pixel, and a third step of arranging the pixel pattern at a predetermined pixel position based on the correspondence relationship. How to create a hologram recording medium, comprising the steps of, a. 2. The method for producing a hologram recording medium according to claim 1 , wherein in the second step, motif pixel information for a plurality of different motifs is prepared, and in the third step, the motif pixel information belongs to different motifs. Regarding a pixel, a method for producing a hologram recording medium, characterized in that different pixel patterns are made to correspond to each other, and a plurality of motifs are expressed by overlapping on the same plane. 3. The method for producing a hologram recording medium according to claim 1 , wherein in the first step, a plurality of pixel patterns having mutually similar parameters are set as one group, and a plurality of groups of pixel patterns are prepared. In the second stage, motif pixel information for a plurality of different motifs is prepared respectively, and in the third stage, for pixels belonging to different motifs, pixel patterns belonging to different groups are made to correspond, and a plurality of motifs are arranged on the same plane. A method for producing a hologram recording medium, characterized in that it is represented in an overlapping manner. 4. A method for producing a hologram recording medium in which a predetermined motif is expressed by a diffraction grating, comprising a pixel pattern in which a grid line having a predetermined line width is arranged at a predetermined pitch and a predetermined angle in a predetermined closed region. , A line width, a pitch, and a first step of preparing a plurality by changing at least one of three parameters, and a plurality of pixels each having a predetermined pixel value on an array of M rows and N columns. By defining the motif pixel information representing a predetermined motif by defining, a second stage is prepared for each of a plurality of different motifs, and a unit subpixel array composed of subpixels arranged in m rows and n columns is defined. A third step of preparing sub-pixel configuration information that defines which motif pixel is to be arranged at each sub-pixel position in this unit sub-pixel array; And a fourth step of defining the correspondence relationship between each pixel defined by the above and each pixel pattern prepared in the first step by referring to the pixel value of each pixel, and the unit subpixel array itself By arranging M rows and N columns to define a sub-pixel array of (m × M) rows (n × N) columns,
A fifth pattern in which a pixel pattern corresponding to each unit subpixel array is extracted for each motif based on the correspondence relationship, and the extracted pixel pattern is arranged at a predetermined subpixel position based on the subpixel configuration information. The method for producing a hologram recording medium, which comprises: 5. A method for producing a hologram recording medium in which a predetermined motif is expressed by a diffraction grating, comprising a pixel pattern in which grid lines having a predetermined line width are arranged in a predetermined closed region at a predetermined pitch and a predetermined angle. , A line width, a pitch, and a first step of preparing a plurality by changing at least one of three parameters, and a plurality of pixels each having a predetermined pixel value on an array of M rows and N columns. By defining the motif pixel information representing a predetermined motif by defining, a second stage is prepared for each of a plurality of different motifs, and a unit subpixel array composed of subpixels arranged in m rows and n columns is defined. A third step of preparing sub-pixel configuration information that defines which motif pixel is to be arranged at each sub-pixel position in this unit sub-pixel array; And a fourth step of defining the correspondence relationship between each pixel defined by the above and each pixel pattern prepared in the first step by referring to the pixel value of each pixel, and the unit subpixel array itself Are arranged in (M / m) rows (N / n) columns to define a subpixel array of M rows and N columns,
A pixel pattern corresponding to each unit sub-pixel array is extracted for each motif based on the correspondence relationship, and a part of the extracted pixel pattern is selected based on the sub-pixel configuration information. A method for producing a hologram recording medium, comprising: a fifth step of arranging at a predetermined sub-pixel position. 6. The method for producing a hologram recording medium according to claim 1 , wherein the entire occupied area as a pixel and the closed area in which the lattice line is arranged in the entire occupied area. A plurality of pixel patterns with different area ratios of and are prepared, and a pixel pattern having an area ratio corresponding to the pixel value of the pixel is made to correspond to each pixel position so that a motif with gradation can be expressed. A method for producing a hologram recording medium, characterized in that 7. A device for producing a hologram recording medium in which a predetermined motif is expressed by a diffraction grating, comprising a pixel pattern in which a grid line having a predetermined line width is arranged at a predetermined pitch and a predetermined angle in a predetermined closed region. , A means for holding a plurality of prepared pixel pattern files by changing at least one of the three parameters of line width, pitch and angle, and a plurality of pixels each having a predetermined pixel value at a predetermined position on the plane. Means for inputting a motif pixel information file expressing a predetermined motif by defining the above, and correspondence between each pixel defined in the motif pixel information file and each pixel pattern prepared in the pixel pattern file And a means for creating a correspondence relationship information file that defines the relationship by referring to the pixel value for each pixel. , On the basis of the correspondence relationship information file, and means for creating image data arranging the pixel pattern at a predetermined pixel position, based on the image data, means for forming a hologram pattern on a predetermined recording medium, m A unit subpixel composed of subpixels arranged in row n columns
For the array, for each subpixel position in this unit subpixel array
Sub-pixel configuration information that determines which motif pixels are arranged
Means for holding a report file, and means for creating the image data,
Pixel pattern placement processing based on the configuration information file
An apparatus for producing a hologram recording medium, which is characterized by performing .