JP5029816B2 - Hologram production method - Google Patents

Description

The present invention relates to a hologram manufacturing method, particularly, it relates to making how the recording the reproduced image of the computer-generated hologram volume hologram.

2. Description of the Related Art Conventionally, there are those in which a hologram is attached to a cash voucher or a credit card or integrally formed to prevent forgery. As this hologram, there is a computer generated hologram by recording interference fringes on a predetermined recording surface by calculation using a computer (Patent Document 1).
JP 2000-214751 A JP 2002-72837 A JP 2005-215570 A "3D Image Conference '99 -3D Image Conference '99-" Lecture Collection CD-ROM (June 30-July 1, 1999, Kogakuin University Shinjuku Campus), Paper "Image Binary CGH by EB Drawing ( 3)-Improvement of stereoscopic effect by hidden surface removal and shading-

  However, the conventional computer holograms proposed so far are excellent in design and security, but are relief-type holograms that are more easily counterfeited than volume-type holograms. There is an inferior part.

The present invention has been made in view of such problems of the prior art, its object is to provide a way of making a good volume hologram design and security properties in a simple way.

The hologram production method of the present invention solves the above-mentioned problem, and defines a predetermined original image, a recording surface for recording the original image, and reference light irradiated to the recording surface. A plurality of calculation points are defined on the recording surface, and the intensity of the interference wave formed by the object light emitted from the light source defined on the original image and the reference light is determined for each calculation point. Divide into unit areas having a certain shape and size including the calculation points into a first area having a first pixel value and a second area having a second pixel value. By defining a binary pattern, a plurality of binary patterns can be defined by changing the occupancy ratio of the first area with respect to the unit area. Having the occupation rate corresponding to the interference wave intensity Allocating the value pattern, on the basis of the binary image consisting of a set of binary patterns assigned to the recording surface, a relief having a parallax on the medium to record the amplitude and phase information, the two-dimensional direction perpendicular Type computer-generated hologram, irradiating the relief-type computer-generated hologram with first reproduction illumination light to generate first diffracted light from the relief-type computer-generated hologram to reproduce the first reproduced image, and hologram recording The first diffracted light and the first reference light are simultaneously incident on the material and recorded as a reflective or transmissive volume hologram.

2. The hologram production according to claim 1, wherein the first reproduction image is reproduced at a position separated from the relief-type computer-generated hologram, and the hologram recording material is disposed in the vicinity of the first reproduction image. Method.

  Further, the 0th-order light of the first reproduction illumination light is not covered with the hologram recording material.

In addition, a relief computer-generated hologram capable of full-color image reproduction under white light is used as the relief-type computer-generated hologram, and the hologram recording material has a single layer by sequentially changing the wavelength of the first reproduction illumination light. Multiple recording is performed in the hologram recording material, or a plurality of hologram layers having different wavelengths recorded in different hologram recording materials are integrally laminated each time the wavelength of the first reproduction illumination light is changed. 4. The hologram manufacturing method according to claim 1, wherein the hologram is a hologram capable of reproducing two or more wavelengths.

In addition, a relief-type computer-generated hologram capable of full-color image reproduction under white light is used as the relief-type computer-generated hologram, and the hologram recording material is formed by integrating a plurality of hologram recording materials each having sensitivity at different wavelengths. 4. The hologram according to claim 1, wherein the holograms are stacked and simultaneously irradiated and recorded with the first reproduction illumination light corresponding to each of the different wavelengths to form a hologram capable of reproducing two or more wavelengths. Hologram production method.

In addition, a plurality of relief-type computer-generated holograms having different wavelengths are used as the relief-type computer-generated hologram, and the hologram recording material is multiplexed in one hologram recording material by sequentially changing the wavelength of the first reproduction illumination light. Two or more wavelengths are reproduced by recording or by laminating a plurality of hologram layers of different wavelengths recorded in different hologram recording materials each time the wavelength of the first reproduction illumination light is changed. 4. The hologram manufacturing method according to claim 1, wherein the hologram is a hologram that can be used.

  In addition, the first reproduced image is reproduced, and the first diffracted light and the first reference light are simultaneously incident on the first-stage hologram recording material arranged in the vicinity of the first reproduced image to record the first-stage hologram. Then, the recorded hologram of the first stage is irradiated with the second reproduction illumination light to generate second diffracted light from the hologram of the first stage to reproduce the second reproduced image, and in the vicinity of the second reproduced image. The second diffracted light and the second reference light are simultaneously incident on the arranged second-stage hologram recording material, and the second-stage hologram is recorded as a reflection-type or transmission-type volume hologram.

  The zero-order light of the first reproduction illumination light is not incident on the first-stage hologram, and the zero-order light of the second reproduction illumination light is at least one not incident on the second-stage hologram. To do.

In addition, a relief computer-generated hologram capable of reproducing a full-color image under white light is used as the relief-type computer-generated hologram, and the wavelength of the first reproduction illumination light is changed in order when the first-stage hologram is produced. A plurality of first-stage holograms corresponding to the wavelengths are produced, and when the second-stage hologram is produced, the second reproduction illumination light having the corresponding wavelength is replaced while replacing the plurality of first-stage holograms corresponding to the respective wavelengths. Incidently, multiple holograms corresponding to the respective wavelengths are recorded in the second-layer hologram recording material of one layer, or in separate second-stage hologram recording materials corresponding to the respective wavelengths. The method for producing a hologram according to claim 7, wherein multilayer recording is performed by recording a hologram corresponding to the wavelength of the hologram.

In addition, a relief computer-generated hologram capable of full-color image reproduction under white light is used as the relief-type computer-generated hologram, and a plurality of hologram recording materials each having sensitivity to different wavelengths when the first stage hologram is manufactured Are laminated together, the first reproduction illumination light corresponding to each of the different wavelengths is simultaneously irradiated and recorded, and the first-stage hologram capable of reproducing two or more wavelengths is produced, and the second-stage hologram is produced. When producing a hologram, a plurality of hologram recording materials each having sensitivity to different wavelengths are laminated together, and the second reproduction illumination light respectively corresponding to the different wavelengths is simultaneously irradiated onto the first-stage hologram to perform recording. The hologram production according to claim 7 or 8, wherein the second-stage hologram capable of reproducing two or more wavelengths is produced. Law.

In addition, a plurality of relief-type computer-generated holograms having different wavelengths are used as the relief-type computer-generated hologram, and a plurality of 1's corresponding to the respective wavelengths are changed by sequentially changing the wavelength of the first reproduction illumination light when the first-stage hologram is produced. A first-stage hologram is manufactured, and when the second-stage hologram is manufactured, the second reproduction illumination light having the corresponding wavelength is incident while replacing the plurality of first-stage holograms corresponding to the respective wavelengths. The hologram corresponding to each wavelength is multiplexed and recorded in the second-stage hologram recording material, or the hologram corresponding to each wavelength is recorded in the separate second-stage hologram recording material corresponding to each wavelength. 9. The hologram manufacturing method according to claim 7, wherein multilayer recording is performed by recording. "

  According to the present invention, a hologram excellent in design and security can be produced by a simple method, and the process of producing a conventional H1 hologram when producing a volume hologram can be reduced. In addition, since the 0th-order light of the reproduction illumination light is not covered with the hologram recording material, noise of the 0th-order light can be prevented from being generated. In addition, since the hologram can be reproduced with two or more wavelengths, a hologram with further enhanced design and security can be produced.

  Further, by using the hologram produced in this way as a security medium, the design and security of the security medium are further improved.

  Hereinafter, a method for producing a hologram of the present embodiment will be described with reference to the drawings. In the present embodiment, first, a computer-generated hologram 1 having a parallax in a two-dimensional direction that is orthogonal is produced. 1 to 8 show the principle of producing the computer-generated hologram 1.

  In the present embodiment, as shown in FIG. 1, a method of recording the original image 10 on the recording surface 20 as interference fringes is used. Here, for convenience of explanation, it is assumed that an XYZ three-dimensional coordinate system is defined as shown and the recording surface 20 is placed on the XY plane. When the optical method is used, an object to be recorded is prepared as the original image 10. The object light O emitted from an arbitrary point P on the original image 10 travels toward the entire recording surface 20. On the other hand, the recording surface 20 is irradiated with the reference light R, and interference fringes between the object light O and the reference light R are recorded on the recording surface 20.

In order to create a computer generated hologram at the position of the recording surface 20, the original image 10, the recording surface 20, and the reference light R are defined as data on the computer, and the interference wave intensity at each position on the recording surface 20 is calculated. That's fine. Specifically, as shown in FIG. 2, the original image 10 is treated as a set of _N point light sources P ₁ , P ₂ , P ₃ ,..., P _i ,. light _{O 1, O 2, O 3} , ..., O i, ..., O N are each calculation point Q (x, y) with progression to the reference light R toward the calculation point Q (x, y) And calculating the amplitude intensity at the position of the calculation point Q (x, y) of the interference wave generated by the interference between the _N object lights O _{1 to} O _N and the reference light R. . The object light and the reference light are usually calculated as monochromatic light. A large number of calculation points corresponding to the required resolution are defined on the recording surface 20, and the calculation of the amplitude intensity is performed for each of these calculation points. A distribution will be obtained.

Specifically, assuming that the coordinates of the point light source arranged on the object are P _i (x _i , y _i , z _i ) and the energy of the point light source is 4πA _i ² , the calculation point Q (x, The combined complex amplitude value O (x, y) of the object light at the position y) can be obtained by the following equation (1).

ここで、Ａ_iは点光源Ｐ_iから発せられた物体光の振幅を表す係数を示し、ｒ_i（ｘ，ｙ）は、式（２）に示すように、点光源Ｐ_iと演算点Ｑ（ｘ，ｙ）との距離を示している。

Here, A _i represents a coefficient representing the amplitude of the object light emitted from the point light source P _i , and r _i (x, y) represents the point light source P _i and the calculation point Q as shown in Equation (2). The distance to (x, y) is shown.

すなわち、式（１）におけるＡ_i／ｒ_i（ｘ，ｙ）の項は、距離による振幅の減衰を示すものである。

That is, the term A _i / r _i (x, y) in equation (1) indicates the attenuation of the amplitude due to the distance.

The next term described in the form of an exponential function is a term indicating the periodic amplitude fluctuation of the object light in the form of complex amplitude, j is a complex unit, and k is k when the wavelength is λ. = 2π / λ, φ _i indicates the initial phase of the point light source at P _i . Here, the term kr _i (x, y) indicates the optical path length. By adding the initial phase φ _i to this optical path length, the combined complex amplitude value of the object light at the calculation point Q (x, y) is obtained. Will be given. The initial phase φ _i can be set randomly for each object beam.

Further, assuming that the incident vector of the reference light R composed of parallel light is (R _x , R _y , R _z ), the amplitude is A _R , and the phase at the coordinate origin is φ _R , the position of the calculation point Q (x, y) The complex amplitude value R (x, y) of the reference light R in can be obtained by the following equation (3).

このような強度分布を示す画像データに基づいて、実際の媒体上に物理的な濃淡パターンやエンボスパターンを形成すれば、原画像１０を干渉縞として記録したホログラムが作成できる。媒体上に高解像度の干渉縞を形成する手法としては、電子線描画装置を用いた描画が適している。電子線描画装置は、半導体集積回路のマスクパターンを描画する用途などに広く利用されており、電子線を高精度で走査する機能を有している。そこで、演算によって求めた干渉波の強度分布を示す画像データを電子線描画装置に与えて電子線を走査すれば、この強度分布に応じた干渉縞パターンを描画することができる。

If a physical gray pattern or emboss pattern is formed on an actual medium based on such image data showing the intensity distribution, a hologram in which the original image 10 is recorded as interference fringes can be created. As a technique for forming high-resolution interference fringes on a medium, drawing using an electron beam drawing apparatus is suitable. An electron beam drawing apparatus is widely used for drawing a mask pattern of a semiconductor integrated circuit, and has a function of scanning an electron beam with high accuracy. Accordingly, if image data indicating the intensity distribution of the interference wave obtained by calculation is applied to the electron beam drawing apparatus and the electron beam is scanned, an interference fringe pattern corresponding to the intensity distribution can be drawn.

  However, a general electron beam drawing apparatus has only a function of drawing a binary image by controlling drawing / non-drawing. Therefore, the intensity distribution obtained by the calculation may be binarized to create a binary image, and this binary image data may be given to the electron beam drawing apparatus.

  FIG. 3 is a conceptual diagram of a general method for recording an interference fringe pattern using such binarization processing. With the above-described calculation, a predetermined interference wave intensity value, that is, an amplitude intensity value of the interference wave is defined at each calculation point Q (x, y) on the recording surface 20. For example, a predetermined amplitude intensity value is also defined at the calculation point Q (x, y) shown in FIG. Therefore, a predetermined threshold value (for example, an average value of all amplitude intensity values distributed on the recording surface 20) is set for the amplitude intensity value, and an arithmetic point having an intensity value equal to or greater than the threshold value is set. A pixel value “1” is given, and a pixel value “0” is given to a calculation point having an intensity value less than this threshold value. Therefore, a pixel value of “1” or “0” is defined at the calculation point Q (x, y) shown in FIG.

Therefore, as shown in FIG. 3B, a unit area U (x, y) is defined at the position of the calculation point Q (x, y), and this unit area U (x, y) is set to “1”. If it is handled as a pixel having any pixel value of “0”, a predetermined binary image can be obtained. If the binary image data is supplied to the electron beam drawing apparatus and drawn, interference fringes can be drawn as a physical binary image. Actually, for example, by creating an embossed plate based on the physically drawn interference fringes and performing embossing using the embossed plate, a hologram having the interference fringes formed as a concavo-convex structure on the surface is obtained. FIG. 4 shows unit areas U1 to U24 that are two-dimensionally arranged on the recording surface 20. In this example, each unit region is a square having a side of 2 μm, because the calculation points Q1 to Q24 defined on the recording surface 20 are arranged at a pitch of 2 μm vertically and horizontally. . Since the calculation point defined on the recording surface 20 functions as a sample point of the interference wave intensity, the point light source pitch defined on the original image 10, the original image 10 and the recording surface 20, and so on. In consideration of the optical conditions such as the distance, the direction of the reference light R, and the wavelength, they may be arranged at an optimum pitch for recording interference fringes. In the example shown in FIG. 4, the pitch of the calculation points Q is 2 μm in both vertical and horizontal directions, but the vertical and horizontal pitches may be changed (in this case, each unit area is a rectangle). In the example shown in FIG. 4, each unit area is arranged on each calculation point so that the center point of the square unit area overlaps each calculation point. It is not always necessary that the positional relationship is as described above. For example, the upper left corner point of each unit area may be defined as a reference point, and the individual unit areas may be arranged so that the upper left corner reference point overlaps the calculation point.

  As described above, predetermined interference wave intensity values are calculated at the calculation points Q1 to Q24 shown in FIG. In the conventional general method, each intensity value is binarized based on a predetermined threshold value and converted into a pixel value of “1” or “0”. Therefore, for example, if the unit area U including the calculation point Q in which the pixel value “1” is defined is treated as a white pixel and the unit area U including the calculation point Q in which the pixel value “0” is defined as a black pixel, Thus, a binary image is obtained. If a physical concavo-convex structure is formed on the basis of the binary image, the white pixel portion is a concave portion and the black pixel portion is a convex portion (or vice versa), a hologram medium can be obtained.

  However, in such a general method for creating a computer generated hologram, since each unit area is limited to either a white pixel or a black pixel, the interference wave intensity obtained by calculation is Is lost.

  Therefore, in the present embodiment, a binary pattern defined by dividing a unit area into a first area having a first pixel value and a second area having a second pixel value is expressed as “ A plurality of types are prepared by changing the occupancy ratio of the first area with respect to the unit area, and the occupancy ratios corresponding to the interference wave intensities at the respective calculation points (the “first area with respect to the unit area”) are prepared. The binary pattern having the area occupancy ratio “)” is assigned.

  First, as shown in FIG. 5, a specific gradation value is assigned to a pixel according to the value of the interference wave intensity. In the present embodiment, as shown in FIG. 6, five types of binary patterns D0 to D4 are prepared in advance. Each of the binary patterns is a pattern in a unit region made up of a square having a side of 2 μm, and includes a first region having a first pixel value “1” (a white portion in the figure) and a second pixel value. And a second region having “0” (the hatched portion in the figure). Of course, the binary pattern D0 includes only the second region, and the binary pattern D4 includes only the first region. For convenience, the area of the other region is 0. Consider a special case. Here, paying attention to “occupancy ratio of the first area (white portion) with respect to the unit area (entire square)”, the occupancy ratios of the binary patterns D0, D1, D2, D3, D4 are 0%, 25%, 50%, 75%, and 100%.

  In any binary pattern, as shown in the figure, the first area (white portion) has a vertical width equal to the vertical width of the unit area (whole square) and has a horizontal width corresponding to a predetermined occupation ratio. In addition, the rectangle constituting the first area is arranged at the center position with respect to the lateral width of the unit area. And the remaining part in which the 1st field in a unit field is arranged serves as the 2nd field (part given hatching). The binary pattern is not limited to that shown in FIG. 6, but may be various patterns as shown in FIG. 7 or other patterns. Further, gradation may be expressed by making each refractive pattern correspond to a different refractive index.

  Now, by selectively assigning the five types of binary patterns D0 to D4 thus prepared to the respective calculation point positions on the recording surface, the interference wave intensity at each calculation point is expressed by five levels of gradation. Is possible. In the example shown in FIG. 5, the interference wave intensity at each calculation point is given as five levels of intensity values from 0 to 4. In order to assign five types of binary patterns D0 to D4 to the five levels of intensity values, for example, a binary pattern D0 for intensity value 0, a binary pattern D1 for intensity value 1, and an intensity value 2 Corresponding relationships such as the binary pattern D2 and the intensity value 3 for the binary pattern D3 and the intensity value 4 for the binary pattern D4 may be defined in advance. FIG. 7 is a diagram illustrating an example of a binary image obtained by assigning a binary pattern corresponding to each intensity value illustrated in FIG. 5 based on the above-described correspondence relationship. Compared to a binary image obtained by a general method, all of them are binary images, but the interference wave intensity value at each calculation point is expressed with gradation information.

  When a binary image as shown in FIG. 8 is obtained, a computer capable of reproducing a high-quality gradation image by forming physical interference fringes on the medium based on the binary image. A hologram medium is obtained. Specifically, an embossed structure in which a black portion in FIG. 8 is a convex portion and a white portion is a concave portion (or vice versa) may be formed on the medium. In practice, it is preferable to form such a binary image by electron beam scanning using an electron beam drawing apparatus. A binary pattern having a dimensional configuration as shown in FIG. 6 has a spot diameter of an electron beam of about 0.05 μm and a scanning accuracy of about 0.01 μm in a currently used electron beam lithography system. If so, it can be drawn sufficiently. Of course, the process up to obtaining the binary image as shown in FIG. 8 is performed by a computer in which a predetermined program is incorporated, and the binary image data created by this computer is actually given to the electron beam drawing apparatus. The physical drawing process is performed.

  In the above method, the amplitude and phase of the object light at the calculation point Q on the divided area may be recorded in addition to the method of recording with interference fringes due to interference with the reference light as described above. As described in 2 and 3, the phase may be recorded by the depth of the groove of the three-dimensional cell having a groove on one side, and the amplitude may be recorded by the width of the groove.

  Alternatively, as described in A.N. W. You may make it record an amplitude and a phase by the method of Lohmann etc., the method of Lee, etc.

  In the present embodiment, the intensity distribution of the interference wave is used to produce the computer-generated hologram 1. However, a complex amplitude distribution may be applied without causing interference with the reference light.

Next, FIG. 9 shows a first embodiment of a method for producing a volume hologram from the CGH original plate 1 as the obtained computer-generated hologram 1. In the present embodiment, as shown in FIG. 9A, the first reproduction illumination light 3 is applied to the obtained CGH original plate 1 on the side opposite to the side on which the H2 hologram recording photosensitive material 21 is arranged. Incident from. At this time, the zero-order light 4 ₀ of the first reproduction illumination light 3, reduces noise By not suffer the H2 hologram recording photosensitive material 21 preferably. When the first reproduction illumination light 3 is incident on the CGH original 1, the first diffracted light 4 is generated from the CGH original 1, and the same position as the relative position of the original image O at the time of recording separated from the surface of the CGH original 1 The first reconstructed image O ′ of the original image O is reconstructed. At this time, as shown in FIG. 9A , the first diffracted light 4 from the CGH original plate 1 is condensed toward the imaging position of the first reproduced image O ′. Thereby, the intensity of the object light can be increased.

  Then, an H2 hologram recording photosensitive material 21 made of a photopolymer, a silver salt material, or the like is disposed in the immediate vicinity of the first reproduced image O ′, and is composed of parallel light from the same light source that is coherent with the first reproduced illumination light 3. The first reference light 5 is simultaneously incident at an arbitrary incident angle from the opposite side or the same side as the first diffracted light 4, and the H2 hologram is exposed in the H2 hologram recording photosensitive material 21.

  Here, for comparison, a two-step method as a conventional volume hologram manufacturing method will be described. FIG. 12 is a side view showing the imaging arrangement (a) of the first stage H1 hologram and the imaging arrangement (b) of the second stage H2 hologram when producing a hologram by the conventional two-step method. First, using an H1 hologram recording photosensitive material 111 such as a photopolymer or a silver salt material, as shown in FIG. 12A, it faces an object 100 (shown as a cube here) to be recorded on a hologram. The H1 hologram recording photosensitive material 111 is disposed. Then, the object 100 is illuminated with a laser beam having a predetermined wavelength and the object light 101 scattered by the object 100 is incident on the photosensitive material 111 for H1 hologram recording, and is incident on the surface of the photosensitive material 111 for H1 hologram recording at an incident angle θ. A reference beam 102 composed of parallel light from the same light source that is coherent with the object beam 100 is simultaneously incident, and the H1 hologram recording photosensitive material 111 is exposed to the hologram of the object 100. The H1 hologram recording photosensitive material 111 exposed with this hologram is post-processed to produce the H1 hologram 111. Here, the H1 hologram recording photosensitive material 111 and the H1 hologram 111 are denoted by the same reference numeral 111.

  Next, as shown in FIG. 12B, the reproduction light 103 conjugate with the reference light 102 at the time of recording is incident on the obtained H1 hologram 111 with respect to the H1 hologram 111. Incident light is incident from the opposite side. Then, diffracted light 104 is generated from the H1 hologram 111, and an image 100 'of the object 100 is reproduced and formed at the same position as the relative position of the object 100 when recording with respect to the surface of the H1 hologram 111. A second-stage H2 hologram recording photosensitive material 121 made of a photopolymer, a silver salt material, or the like is disposed in the vicinity of the position where the image 100 ′ of the object 100 is formed, and from the same light source that can interfere with the reproduction illumination light 103. The reference beam 105 composed of the parallel beam is simultaneously incident at an arbitrary incident angle from the opposite side or the same side as the diffracted beam 104, and the second stage H2 hologram is exposed in the photosensitive material 121 for H2 hologram recording. The H2 hologram recording photosensitive material 121 on which the second stage H2 hologram is exposed is post-processed to produce an H2 hologram 121. Here, the H2 hologram recording photosensitive material 121 and the H2 hologram 121 are denoted by the same reference numeral 121.

  The H2 hologram 121 recorded as described above is a volume hologram. When the reference beam 105 is incident from the side opposite to the diffracted beam 104, the H2 hologram 121 is recorded as a reflection type hologram, and the reference beam 105 is recorded on the same side as the diffracted beam 104. When the light is incident from the recording medium, it is recorded as a transmission hologram.

  As described above, the method of the embodiment according to the present invention uses the CGH original plate 1 as compared with the conventional hologram manufacturing method by the two-step method. Therefore, when the volume hologram 21 corresponding to the H2 hologram is manufactured, The step of manufacturing the H1 hologram 111 can be reduced.

  In this embodiment, the CGH original plate 1 capable of reproducing a full-color image under white light is used as the CGH original plate 1, and the photosensitive material 21 for H2 hologram recording changes the wavelength of the first reproduction illumination light 3 in order. A plurality of different wavelengths recorded in the H2 hologram recording photosensitive material 21 are recorded in each layer of the H2 hologram recording photosensitive material 21 or each time the wavelength of the first reproduction illumination light 3 is changed. It is preferable that the hologram layer is integrally laminated to form the H2 hologram 21 capable of reproducing two or more wavelengths.

  Further, the CGH original plate 1 capable of reproducing a full-color image under white light is used as the CGH original plate 1, and the H2 hologram recording photosensitive material 21 includes a plurality of H2 hologram recording photosensitive materials 21 each having sensitivity to different wavelengths. The H2 hologram 21 may be laminated so that the first reproduction illumination light 3 corresponding to each of the different wavelengths is irradiated and recorded at the same time, and can be reproduced with two or more wavelengths.

  In addition, the CGH master plate 1 having a plurality of different wavelengths is used as the CGH master plate 1, and the H2 hologram recording photosensitive material 21 is changed into the one layer H2 hologram recording photosensitive material 21 by sequentially changing the wavelength of the first reproduction illumination light 3. Multiple recording is performed, or each time the wavelength of the first reproduction illumination light 3 is changed, a plurality of hologram layers having different wavelengths recorded in different H2 hologram recording photosensitive materials 21 are laminated together. It is good also as the H2 hologram 21 which can reproduce | regenerate more than a wavelength.

  Further, the CGH original plate 1 capable of reproducing a full-color image under white light is used as the CGH original plate 1, and the H2 hologram recording photosensitive material 21 is simultaneously irradiated with the first reproduction illumination light 3 having a different wavelength to form a single layer. The H2 hologram 21 may be recorded in the H2 hologram recording photosensitive material 21 by multiple recording and capable of reproducing two or more wavelengths.

  Next, a second embodiment of a method for producing a volume hologram from the obtained CGH master 1 will be described. First, a second embodiment of the present invention shown in FIG. 10 will be described. FIG. 10A shows an imaging arrangement for producing the first-stage H1 hologram 11 from the CGH original plate 1, and FIG. 10B shows the production of the second-stage H2 hologram 21 from the first-stage H1 hologram 11. It is a figure which shows the imaging | photography arrangement | positioning.

  As shown in FIG. 10A, a photosensitive material 11 for H1 hologram recording such as a photopolymer or a silver salt material is disposed facing the CGH original plate 1. Then, the CGH original 1 is irradiated with the first reproduction illumination light 3 to generate the first diffracted light 4, and the first reproduction image O ′ of the original image O is formed, and the H1 hologram recording photosensitive material 11 is subjected to the first reproduction. 1 diffracted light 4 is incident. Then, simultaneously with the first diffracted light 4, first reference light 5 made of parallel light from the same light source coherent with the first diffracted light 4 at the incident angle θ is incident on the surface of the photosensitive material 11 for H1 hologram recording simultaneously. The hologram of the first reproduced image O ′ is exposed to the photosensitive material 11 for H1 hologram recording. At this time, it is preferable that the 0th-order light of the first reproduction illumination light 3 is not covered with the photosensitive material 11 for H1 hologram recording because noise is reduced. Then, the H1 hologram recording photosensitive material 11 on which the hologram is exposed is post-processed to produce the H1 hologram 11. Here, the H1 hologram recording photosensitive material 11 and the H1 hologram 11 are denoted by the same reference numeral 11.

  Next, as shown in FIG. 10B, an H2 hologram recording photosensitive material 21 such as a photopolymer or a silver salt material is arranged facing the obtained H1 hologram 11, and the first reference light at the time of recording is arranged. 5 is incident on the H1 hologram 11 from the side opposite to the side on which the first reference light 5 is incident. At this time, it is preferable that the 0th-order light of the second reproduction illumination light 6 is not covered with the H2 hologram recording photosensitive material 21 because noise is reduced.

  Then, the second diffracted light 7 is generated from the H1 hologram 11, and the second diffracted light 7 and the parallel light from the same light source coherent with the second diffracted light 7 at a predetermined incident angle on the surface of the H2 hologram recording photosensitive material 21. The second reference light 8 made of light is simultaneously incident to expose the hologram of the second reproduced image O ″ on the H2 hologram recording photosensitive material 21. At this time, when the H2 hologram 21 is a transmission type, the second reference light 8 is incident from the same side as the second diffracted light 7, and when the H2 hologram 21 is a reflection type, the second reference light 8 is the second diffracted light 7. Incident from the opposite side. The photosensitive material 21 for recording the H2 hologram on which the hologram is exposed is post-processed to produce the H2 hologram 21. Here, the H2 hologram recording photosensitive material 21 and the H2 hologram 21 are denoted by the same reference numeral 21.

  FIG. 11 is a diagram showing a shooting arrangement when replicating an H3 hologram 31 having the same characteristics as an H2 hologram 21 manufactured as a reflection type. As shown in FIG. 11, a volume type H3 hologram recording photosensitive material 31 such as a photopolymer or the like is placed in close contact with an H2 hologram 21 made of a volume type reflection hologram or in close contact with a refractive index matching liquid. Next, the H3 hologram 21 is conjugated with the first reference light 5 when the H2 hologram shown in FIG. 9 or the second reference light 8 when the H2 hologram shown in FIG. The third reproduction illumination light 9 is incident from the side opposite to the side on which the second reference light 8 is incident when the H2 hologram is produced. Then, the third reproduction illumination light 9 incident on the H3 hologram recording photosensitive material 31 and the first-order diffracted light from the H2 hologram 21 are caused to interfere in the H3 hologram recording photosensitive material 31 to cause the H3 hologram recording photosensitive material 31 to have H2 The hologram 21 is duplicated.

  Thus, a hologram can be produced by a simple method without using an actual object. Furthermore, since an original image can be produced by a computer, a hologram having a fine structure and excellent design and security can be produced.

  In the present embodiment, the computer-generated hologram 1 capable of reproducing a full-color image under white light is used as the CGH master 1, and the wavelength of the first reproduction illumination light 3 is changed in order when the first stage H1 hologram 11 is produced. A plurality of first-stage H1 holograms 11 corresponding to the respective wavelengths are manufactured, and the corresponding wavelengths are changed while the plurality of first-stage H1 holograms 11 corresponding to the respective wavelengths are replaced when the second-stage H2 hologram 21 is manufactured. The second reproduction illumination light 6 is incident, so that holograms corresponding to the respective wavelengths are multiplexed or recorded in the second layer of the H2 hologram recording photosensitive material 21 of one layer, or corresponding to the respective wavelengths. Multi-layer recording may be performed by recording H2 holograms 21 corresponding to respective wavelengths in separate second-stage H2 hologram recording photosensitive materials 21.

  Further, the CGH original plate 1 capable of reproducing a full-color image under white light is used as the CGH original plate 1, and a plurality of H1 hologram recording photosensitive materials 11 each having sensitivity to different wavelengths when the first stage H1 hologram 11 is manufactured. Are laminated together, the first reproduction illumination light 3 corresponding to each of the different wavelengths is simultaneously irradiated and recorded, and the first-stage H1 hologram 11 capable of reproducing two or more wavelengths is produced. When the H2 hologram 21 is produced, a plurality of H2 hologram recording photosensitive materials 21 each having sensitivity to different wavelengths are laminated together, and the second reproduction illumination light 6 corresponding to each different wavelength is applied to the first stage H1 hologram 11. The second stage H2 hologram 21 that can be irradiated and recorded at the same time and can be reproduced with two or more wavelengths may be produced.

  In addition, a plurality of CGH master plates 1 having different wavelengths are used as the CGH master plate 1, and when the first stage H1 hologram 11 is manufactured, the wavelength of the first reproduction illumination light 3 is changed in order, and a plurality of first stage H1s corresponding to the respective wavelengths. When the hologram 11 is produced and the second stage H2 hologram 21 is produced, the second reproduction illumination light 6 having the corresponding wavelength is incident while replacing the plurality of first stage H1 holograms 11 corresponding to the respective wavelengths. The H2 hologram 21 corresponding to each wavelength is multiplexed or recorded in the second layer H2 hologram recording photosensitive material 21 of one layer, or separate second-stage H2 hologram recording photosensitive corresponding to each wavelength. Multi-layer recording may be performed by recording holograms corresponding to the respective wavelengths in the material 21.

  Further, the CGH original plate 1 capable of reproducing a full-color image under white light is used as the CGH original plate 1, and when the first stage H1 hologram 11 is produced, the first reproduction illumination light 3 having a different wavelength is irradiated simultaneously. The first-stage H1 hologram 11 capable of reproducing two or more wavelengths is produced by multiple recording in the photosensitive material 11 for recording the H1 hologram layer, and the second-stage H2 hologram 21 has different wavelengths. 2 reproduction illumination light 6 is simultaneously irradiated onto the first-stage H1 hologram 11 to multiplex-record H2 holograms 21 corresponding to the respective wavelengths in one layer of the second-stage H2 hologram recording photosensitive material 21; It is good also as the H2 hologram 21 which can reproduce | regenerate 2 wavelengths or more.

  As a result, a hologram with further enhanced design and security can be produced.

  Furthermore, the hologram produced in this way can be used for security media such as cards, brand protection labels, banknotes, passports, stickers, portable stickers or gift certificates.

  As a result, the design and security of the security medium are further improved.

  The hologram manufacturing method of the present invention has been described based on the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made.

It is a perspective view which shows the concept of the recording method of a computer composition hologram. It is a figure which shows the specific example based on the concept of the arithmetic processing of FIG. It is a figure which shows the concept which acquires a binary image from interference wave intensity distribution. It is a figure which shows the area | region arranged in the grid | lattice form on the recording surface form. It is a figure which shows the quinary interference fringe intensity | strength of each area | region. It is a figure which shows the structure of a binary pattern. It is a figure which shows the structure of another binary pattern. It is a figure which shows the binary image obtained by this embodiment. It is a figure which shows 1st Embodiment of this invention. It is a figure which shows 2nd Embodiment of this invention. It is a figure which shows a 3rd hologram. It is a figure which shows the prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... CGH original plate (computer synthesis hologram), CGH original recording medium 3 ... 1st reproduction | regeneration illumination light 4 ... 1st diffracted light 4 ₀ ... 0th-order light 5 ... 1st reference light 6 ... 2nd reproduction | regeneration illumination light 7 ... 1st 2 diffracted light 8 second reference light 9 third reproduction illumination light 10 original image 20 recording surface 11 H1 hologram, photosensitive material for recording H1 hologram (first-stage hologram recording material)
21... H2 hologram, photosensitive material for recording H2 hologram (second-stage hologram recording material)
31. H3 hologram, photosensitive material for recording H3 hologram

Claims (11)

Define a predetermined original image, a recording surface for recording the original image, and a reference light to be irradiated to the recording surface,
Defining a plurality of calculation points on the recording surface;
For each calculation point, calculate the intensity of the interference wave formed by the object light emitted from the light source defined on the original image and the reference light,
By dividing the unit region including the calculation point into a unit region having a certain shape and size into a first region having a first pixel value and a second region having a second pixel value Define value patterns,
A plurality of binary patterns are defined by changing an occupancy ratio of the first area with respect to the unit area,
A binary pattern having the occupancy corresponding to the interference wave intensity for each calculation point is allocated to the position of each calculation point,
Based on a binary image consisting of a set of binary patterns allocated on the recording surface, amplitude information and phase information are recorded on a medium, and a relief-type computer-generated hologram having parallax in an orthogonal two-dimensional direction is recorded. Made,
The relief-type computer-generated hologram is irradiated with a first reproduction illumination light to generate first diffracted light from the relief-type computer-generated hologram to reproduce a first reproduced image, and the hologram recording material has the first diffracted light and A hologram manufacturing method, wherein the first reference light is simultaneously incident and recorded as a reflection type or transmission type volume hologram. 2. The hologram manufacturing method according to claim 1, wherein the first reproduced image is reproduced at a position separated from the relief-type computer-generated hologram, and the hologram recording material is disposed in the vicinity of the first reproduced image.   3. The hologram manufacturing method according to claim 1, wherein the zero-order light of the first reproduction illumination light is not covered with the hologram recording material. As the relief-type computer-generated hologram, a relief-type computer-generated hologram capable of reproducing a full-color image under white light is used, and the hologram recording material is a single layer of the hologram by changing the wavelength of the first reproduction illumination light in order. Multiple recording in the recording material, or a plurality of hologram layers of different wavelengths recorded in different hologram recording materials each time the wavelength of the first reproduction illumination light is changed, 4. The hologram manufacturing method according to claim 1, wherein the hologram is a hologram capable of reproducing two or more wavelengths. As the relief-type computer-generated hologram, a relief-type computer-generated hologram capable of full-color image reproduction under white light is used, and the hologram recording material is formed by integrally laminating a plurality of hologram recording materials each having sensitivity to different wavelengths. The hologram according to any one of claims 1 to 3, wherein a hologram capable of reproducing two or more wavelengths is obtained by simultaneously irradiating and recording the first reproduction illumination light respectively corresponding to the different wavelengths. Manufacturing method. A plurality of relief-type computer-generated holograms having different wavelengths are used as the relief-type computer-generated hologram, and the hologram recording material performs multiple recording in one layer of the hologram recording material by sequentially changing the wavelength of the first reproduction illumination light. Or, each time the wavelength of the first reproduction illumination light is changed, two or more wavelengths can be reproduced by integrally laminating a plurality of hologram layers having different wavelengths recorded in the hologram recording materials. The method for producing a hologram according to claim 1, wherein the hologram is a simple hologram.   Reconstructing the first reconstructed image, recording the first-stage hologram by simultaneously injecting the first diffracted light and the first reference light into the first-stage hologram recording material disposed in the vicinity of the first reconstructed image; The recorded hologram of the first stage is irradiated with second reproduction illumination light to generate second diffracted light from the hologram of the first stage to reproduce the second reproduced image, which is arranged in the vicinity of the second reproduced image. 2. The second-stage hologram is recorded as a reflection-type or transmission-type volume hologram by simultaneously causing the second diffracted light and the second reference light to enter a second-stage hologram recording material. Hologram production method.   The zero-order light of the first reproduction illumination light is not incident on the first-stage hologram, and the zero-order light of the second reproduction illumination light is at least one not incident on the second-stage hologram. Item 8. A hologram production method according to Item 7. As the relief-type computer-generated hologram, a relief-type computer-generated hologram capable of reproducing a full-color image under white light is used, and the wavelength of the first reproduction illumination light is changed in order at the time of producing the first-stage hologram. A plurality of corresponding first-stage holograms are produced, and at the time of producing the second-stage hologram, the second reproduction illumination light having the corresponding wavelength is incident while replacing the plurality of first-stage holograms corresponding to the respective wavelengths. Thus, the hologram corresponding to each wavelength is multiplexed and recorded in the second-layer hologram recording material of one layer, or each wavelength is separately recorded in the second-stage hologram recording material corresponding to each wavelength. The method for producing a hologram according to claim 7, wherein multilayer recording is performed by recording a hologram corresponding to. As the relief-type computer-generated hologram, a relief-type computer-generated hologram capable of reproducing a full-color image under white light is used, and a plurality of hologram recording materials each having sensitivity to different wavelengths are integrated when the first-stage hologram is produced. The first-stage hologram capable of reproducing two or more wavelengths is produced by simultaneously irradiating and recording the first reproduction illumination light respectively corresponding to the different wavelengths. At the time of production, a plurality of hologram recording materials each having sensitivity to different wavelengths are integrally laminated, and the second reproduction illumination light corresponding to each of the different wavelengths is simultaneously irradiated onto the first stage hologram for recording, 9. The hologram production method according to claim 7, wherein the second-stage hologram capable of reproducing two or more wavelengths is produced. A plurality of relief-type computer-generated holograms having different wavelengths are used as the relief-type computer-generated hologram, and a plurality of first-stages corresponding to the respective wavelengths are obtained by sequentially changing the wavelength of the first reproduction illumination light when the first-stage hologram is produced. When the second stage hologram is manufactured, the second reproduction illumination light having the corresponding wavelength is made incident while the plurality of first stage holograms corresponding to the respective wavelengths are exchanged. The hologram corresponding to each wavelength is multiplexed and recorded in the hologram recording material of the second stage, or the hologram corresponding to each wavelength is recorded in a separate second-stage hologram recording material corresponding to each wavelength. 9. The hologram manufacturing method according to claim 7, wherein multi-layer recording is performed.

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