JP4561206B2 - Hologram recording apparatus, recording medium, recording medium holding member, and hologram recording method - Google Patents

Description

  The present invention relates to a hologram recording apparatus, a recording medium, a recording medium holding member, and a hologram recording method, and in particular, a hologram recording apparatus capable of recording a hologram having a high anti-counterfeit effect and a decoration effect on a recording medium, and a high anti-counterfeit A hologram-recorded recording medium having an effect and a decoration effect, a recording medium holding member having a hologram-recording recording medium having a high anti-counterfeiting effect and a decoration effect, and a high anti-counterfeiting effect and a decoration effect The present invention relates to a hologram recording method capable of recording a hologram on a recording medium.

  As an anti-counterfeiting effect and a decoration effect, a technique is used in which a hologram whose color or pattern changes with the addition or subtraction of light on a recording medium such as a card or paper is used.

  Holograms generally used for these applications include surface relief holograms recorded by surface irregularities, volume holograms recorded as refractive index modulation inside the resin using photosensitive resin, etc., simple diffraction gratings There is a grating image in which an image is formed as a small pixel.

  In any of these holograms, a master hologram is used for replication. In the surface relief type hologram, a metal mold is produced from a concavo-convex shape formed on a photoresist or the like using a plating technique. A large number of holograms are duplicated by heating and pressing the same pattern onto a thermoplastic using this mold. In addition, the volume hologram is replicated by using a master hologram and performing close contact exposure to a new photosensitive resin recording medium.

  Therefore, these conventional holograms are suitable for duplicating the same hologram from the original, but it is practically impossible to produce individually different information such as a face photograph and ID information as a hologram.

In order to overcome these problems, a technique has been proposed in which a transfer ribbon made of a hologram foil is transferred into an arbitrary shape using a heating means such as a thermal head (Patent Documents 1 to 3, etc.).
In addition, there is a method in which different holograms are directly formed individually on an optical recording layer such as a photosensitive resin formed on a card, film, or paper using an existing hologram recording method. In this method, signal light having a pattern formed according to an image or character to be recorded is incident on the recording medium, and the reference light is crossed so as to cover it.
JP 2000-163535 A JP 2000-2111256 A JP 2000-2111257 A

However, the techniques of Patent Documents 1 to 3 have the following problems.
(1) An expensive hologram transfer foil ribbon is required.
(2) It is necessary to record the hologram on the entire ribbon surface in advance.
(3) Since the hologram formed on the transfer foil ribbon is not used except for the transferred pattern and is difficult to reuse, there are many useless parts.
(4) Since there is another hologram transfer foil having substantially the same diffraction grating as the transfer partner, the security is lowered.
(5) Discarding the transfer foil remaining after transfer becomes a security and environmental problem.

Further, when the signal light is incident on the recording medium and the reference light is crossed and irradiated so as to cover it, there are the following problems.
(1) As shown in FIG. 10A, the signal light L1 and the reference light L2 are irradiated to the recording medium 100 for recording the hologram. However, the pattern of the signal light L1 (here, the letter X) ) Does not exist, the reference light L2 is irradiated alone. Therefore, as shown in FIG. 10B, the region 102 irradiated with the reference light due to multiple interference of the layer structure constituting the recording medium 100 or the like. Unnecessary diffraction gratings (hatched portions in the figure) are formed, thereby reducing the contrast of the hologram. In order to prevent this, it is effective to form an antireflection layer or the like on the recording medium 100, but this increases the cost of the recording medium 100.
(2) There is a method in which a mask on which a pattern to be recorded is formed is adhered to a recording medium and irradiated with two light waves. However, since a mask is required, it is difficult to individually record different holograms. That is, there is a problem in on-demand performance.

  The present invention has been made to solve the above problems, and a first object is to provide a hologram recording apparatus capable of recording a hologram having a high anti-counterfeit effect and a decoration effect on a recording medium, and a high anti-counterfeit effect and decoration. It is an object of the present invention to provide a recording medium on which a hologram is recorded having an effect, and a recording medium holding member including a recording medium on which a hologram is recorded having a high anti-counterfeiting effect and a decoration effect.

  A second object is to make it possible to record different holograms on an individual basis at low cost.

The invention according to claim 1 is a hologram recording apparatus that irradiates a photosensitive recording medium with signal light and reference light, and records a hologram on the recording medium by interference between the signal light and the reference light. A signal light irradiating means for irradiating the recording medium with signal light; and a reference light irradiating means for irradiating reference light only to a portion of the recording medium irradiated with the signal light. , And at least one of the reference beams is characterized by intensity modulation .

  Next, the operation of the hologram recording apparatus according to claim 1 will be described.

  In the hologram recording apparatus according to claim 1, the reference light is irradiated only to a portion irradiated with the signal light on the photosensitive recording medium, and the portion irradiated with the signal light on the recording medium, that is, a portion other than the pattern portion. Since an unnecessary hologram is not recorded, the contrast between the pattern portion and the portion other than the pattern portion can be increased.

Further , since intensity modulation (or intensity distribution) is given to at least one of the signal light and the reference light, the hologram portion on the recording medium can have a density distribution.

Invention according to claim 2, in a hologram recording apparatus according to claim 1, a light source for emitting a light beam, a spatial light modulator for modulating the light beam emitted from the light source, said spatial light modulator A light separating means that transmits a part of the light beam through the light beam to be either one of the signal light and the reference light, and reflects the other part to be either the signal light or the reference light; and the light separation disposed to the reference light emission side of the device, the optical deforming the reference light as the reference light only in the region where the signal light is irradiated in the recording medium in response to the incident angle to the recording medium is irradiated And a system.

Next, the operation of the hologram recording apparatus according to claim 2 will be described .

  Since the incident angle to the recording medium differs between the signal light and the reference light, a part of the light beam that has passed through the spatial light modulator is transmitted through the spatial light modulator using the light separation means, and the other part is reflected. When the reference light is used, the reference light is deformed using an optical system so that the reference light is irradiated only to the portion of the recording medium irradiated with the signal light corresponding to the incident angle to the recording medium.

Note that a part of the light beam that has passed through the spatial light modulator may be transmitted through the spatial light modulator using the light separating means to be the reference light, and the other part may be reflected to be the signal light.
According to a third aspect of the present invention, in the hologram recording apparatus according to the second aspect, the optical system includes an anamorphic optical system, and the reference light is applied to the recording medium via the anamorphic optical system. It is characterized by that.
Next, the operation of the hologram recording apparatus according to claim 3 will be described.
In the hologram recording apparatus according to the third aspect, the reference light is applied to the recording medium via the anamorphic optical system.

  According to a fourth aspect of the present invention, in the hologram recording apparatus according to the first or second aspect, a light source that emits a light beam and a part of the light beam that is emitted from the light source are transmitted through the signal light and A light separation unit that reflects either one of the reference light and the other part of the signal light or the reference light, and is disposed on the signal light emission side of the light separation unit, and irradiates the signal light. A first spatial light modulator that generates a pattern; and a second spatial light modulator that is disposed on the reference light emission side of the light separating unit and generates an irradiation pattern of the reference light. .

  Next, the operation of the hologram recording apparatus according to claim 4 will be described.

  Since the incident angle to the recording medium differs between the signal light and the reference light, when the light beam from the light source is separated into two light beams by the light separation means, the signal light irradiation pattern on the signal light emission side of the light separation means A first spatial light modulator for generating a reference light, a second spatial light modulator for generating a reference light irradiation pattern on the reference light emitting side of the light separating means, and a signal light of the recording medium being irradiated Irradiation patterns are formed by the respective spatial light modulators so that the reference light is irradiated only to the portions to be irradiated.

  The light separation means may be used to transmit a part of the light beam emitted from the light source to be used as signal light, and the other part may be reflected as reference light, or a part of the light beam emitted from the light source. May be used as the reference light and the other part may be reflected as the signal light.

  According to a fifth aspect of the present invention, in the hologram recording apparatus according to the third or fourth aspect of the present invention, there is provided a changing unit that changes an angle of the reference light with respect to the signal light.

  Next, the operation of the hologram recording apparatus according to claim 5 will be described.

  In the hologram recording apparatus according to the fifth aspect, the angle of the reference light with respect to the signal light can be changed by the changing means. For this reason, multiple exposure can be performed by changing the angle of the reference light with respect to the signal light.

  According to a sixth aspect of the present invention, in the hologram recording apparatus according to any one of the third to fifth aspects, the diffusing unit diffuses the incident light beam on the reference light emitting side of the light separating unit. It is characterized by having arranged.

  Next, the operation of the hologram recording apparatus according to the sixth aspect will be described.

  In the hologram recording apparatus according to the sixth aspect, the recording medium is irradiated with the reference light that has been diffused by the diffusion means.

  The invention according to claim 7 is the hologram recording apparatus according to any one of claims 3 to 6, wherein the light source emits light beams having a plurality of different wavelengths. .

  In the hologram recording apparatus according to the seventh aspect, multiple exposure can be performed with light beams having a plurality of different wavelengths, and a color hologram can be obtained on a recording medium.

  A recording medium according to an eighth aspect is characterized in that a hologram is recorded by the hologram recording apparatus according to any one of the first to seventh aspects.

  Since the hologram of the recording medium according to the eighth aspect is recorded by the hologram recording apparatus according to any one of the first to seventh aspects, it has a high anti-counterfeiting effect and a decorative effect.

  A recording medium holding member according to a ninth aspect carries the recording medium according to the eighth aspect.

  Since the recording medium holding member according to the ninth aspect carries the recording medium according to the eighth aspect, the recording medium holding member has a high anti-counterfeiting effect and a decorative effect.

The invention according to claim 10 is a hologram recording method in which a photosensitive recording medium is irradiated with signal light and reference light, and a hologram is recorded on the recording medium by interference between the signal light and the reference light. In this case, only the portion of the signal light irradiated on the recording medium is irradiated with reference light, and at least one of the signal light and the reference light is given intensity modulation .

  Next, a hologram recording method according to claim 10 will be described.

11. The hologram recording method according to claim 10, wherein the photosensitive recording medium is irradiated with the reference light only on the portion irradiated with the signal light, and the portion other than the pattern portion on which the signal light is irradiated on the recording medium. Since an unnecessary hologram is not recorded, the contrast between the pattern portion and the portion other than the pattern portion can be increased.
Further, since intensity modulation (or intensity distribution) is given to at least one of the signal light and the reference light, the hologram portion on the recording medium can have a density distribution.

  As described above, the hologram recording apparatus of the present invention has an excellent effect that a hologram capable of obtaining a high forgery prevention effect and a decoration effect can be recorded on a recording medium.

  The recording medium of the present invention has an excellent effect that a high anti-counterfeit effect and a decorative effect can be obtained.

  The recording medium holding member of the present invention has an excellent effect that a high anti-counterfeiting effect and a decorative effect can be obtained.

  Moreover, according to the hologram recording method of the present invention, there is an excellent effect that a hologram capable of obtaining a high forgery prevention effect and a decoration effect can be recorded on a recording medium.

[First Embodiment]
Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows the configuration of a hologram recording apparatus 10 according to the first embodiment of the present invention.

  As shown in FIG. 1A, the hologram recording apparatus 10 includes a laser light source 12 that emits a light beam. As the laser light source 12, laser light in the visible region having a wavelength of 400 nm to 780 nm is preferable, and a laser light source that emits a wavelength sensitive to the recording material can be used. Furthermore, since the reproduced image from the hologram exhibits a color close to that of the recording light, when a red hologram is to be formed, for example, a wavelength of 580 nm or more is used, a wavelength of 500 to 580 nm for green, and a wavelength of 500 nm or less for blue. Good. On the light beam emission side of the laser light source 12, a shutter 14, a reflection mirror 16, a beam expander 18 for expanding the beam diameter, a reflection mirror 20, a spatial light modulator 22, and a light separation means 24 are arranged in this order.

  In this embodiment, the light separating unit 24 uses a half mirror that reflects a part of the incident light beam. Here, a half mirror is used as the light separating means 24, but a known optical element such as a beam splitter or a polarizing beam splitter can be used.

  As the spatial light modulator 22, for example, a transmissive liquid crystal display element can be used. Here, although a transmissive liquid crystal display element is used as the spatial light modulator 22, a known spatial light modulator such as a reflective liquid crystal display element or an electrically drivable mirror array can be used.

  As shown in FIG. 1B, the spatial light modulator 22 is connected to a computer 25, and patterns (characters, numbers, images, etc.) created by the user using the computer 25 are displayed. Yes.

  As shown in FIG. 1A, on the light beam transmitting side of the light separating means 24, an imaging optical system 26 and a loading unit 30 for arranging a recording medium 28 are arranged.

  Details of the recording medium 28 will be described later.

  The imaging optical system 26 images the pattern displayed on the spatial light modulator 22 on the recording medium.

  In the present embodiment, the light beam transmitted through the light separating means 24 is used as signal light for producing a hologram, and the light beam reflected from the light separating means 24 is used as reference light for producing a hologram.

  In the spatial light modulator 22 of the present embodiment, a pattern, for example, a letter “X” as shown in the figure is displayed, and the light beam is transmitted only through the pattern portion.

  Therefore, the recording medium is irradiated with the light beam of only the pattern portion as the signal light.

  In the present embodiment, the light beam as the signal light is irradiated perpendicularly to the recording medium 28. Here, the signal light is irradiated perpendicularly to the recording medium 28, but this does not limit the present invention. As will be described later, any irradiation angle can be selected as long as the same pattern can be irradiated on the recording medium.

  An anamorphic optical system 34 such as a reflecting mirror 32 and an anamorphic lens is disposed on the light beam reflecting side of the light separating means 24.

  The light beam reflected by the light separating means 24 is irradiated as a reference light to the recording medium 28 from an oblique direction via the anamorphic optical system 34.

  In the present embodiment, the angle formed by the reference light and the signal light is set to θ. Here, the reference light and the signal light may be irradiated onto the recording medium in any state of a plane wave, divergent light, and convergent light. It is preferable to use divergent light or convergent light, which can improve the visibility under ambient lighting. Further, it is preferable to adjust the polarization directions of the reference light and the signal light on the recording medium by inserting a λ / 2 wavelength plate or the like in the optical path. In a recording material that reacts to light intensity such as a photopolymer, it is preferable that both the signal light and the reference light are s-polarized with respect to the recording medium. When a polarization-sensitive recording material that exhibits light-induced anisotropy, such as an azo polymer, is used, an arbitrary polarization state such as linearly polarized light or elliptically polarized light can be selected.

  In the present embodiment, since the signal light is irradiated perpendicularly to the recording medium 28 and the reference light is irradiated obliquely to the recording medium 28, the spatial light modulator is provided without the anamorphic optical system 34. The magnification of the pattern generated in 22 differs only in one direction on the recording medium.

The anamorphic optical system 34 of the present embodiment forms an image of the pattern displayed on the spatial light modulator 22 on the recording medium, but the reference light pattern matches the signal light pattern on the recording medium. The reference beam is deformed by cos θ times only in one direction (in this embodiment, the direction corresponding to the vertical direction of the letter “X”). Therefore, on the recording medium, the reference light is irradiated only to the place where the signal light is irradiated.
(recoding media)
2A and 2B are views showing an example of the recording medium holding member 60 to which the recording medium 28 is added. The recording medium 28 of the present embodiment is, for example, a small piece formed in a sheet shape having a thickness of several tens of μm and an area of several mm square, and is attached to the recording medium holding member 60 by a transparent protective film 62. ing.

  As shown in FIG. 3, one surface of the recording medium 28 may be directly attached on the recording medium holding member via the adhesive layer 64, and the other surface may be protected with a protective film 62.

  Next, details of each member constituting the recording medium 28 of the present invention will be described below.

  The recording medium 28 uses a hologram recording material whose refractive index and transmittance change at least by light irradiation in order to record a hologram. In the present invention, a known material can be used. In the present invention, it is preferable to use a hologram recording material of a type in which the refractive index changes because the sensitive wavelength can be easily adjusted.

  Examples of the hologram recording material include inorganic ferroelectric crystals such as barium titanate, lithium niobate, and bismuth silicate as inorganic materials. However, in the present invention, an organic material-based hologram recording material is used in terms of manufacturability of the hologram recording medium, flexibility in the hologram recording medium, and the necessity of an external electric field when changing the refractive index. It is particularly preferable to use

  As an organic material-based hologram recording material, it is preferable to use a photopolymer or an azopolymer.

  As the photopolymer, a known material whose refractive index or transmittance is changed by a chemical change in a portion irradiated with light can be used. As a positive polymer (a material that is solubilized by light irradiation), Examples include materials that change functional groups and materials that have a reduced molecular weight. Negative types (materials that cure the light-irradiated part) include materials that polymerize reactive monomers when irradiated with light, materials that polymerize with generated radicals, Examples include materials that overlap (condense) with the generated acid, materials in which components diffuse and move between the polymerized and non-polymerized parts, and materials that crosslink by light irradiation (for example, “Photopolymer Basics and Applications” "Akio Yamaoka, CMC Publishing"), it is more preferable to use a negative type in the present invention.

  In addition, since a photopolymer basically has an irreversible reaction due to light irradiation, it is suitable for producing a read-only type hologram recording medium.

  As the photopolymer, for example, a photopolymer film (for example, DuPont, Omnidex, etc.) previously formed in a film shape, a volume hologram photosensitive material (Nihon Paint Co., Ltd.), or the like can be used.

  An azo polymer is a polymer containing an azo group that undergoes trans-cis isomerization when irradiated with light, and can record / reproduce a hologram by utilizing a change in refractive index. As the azo polymer, a known material can be used, but an azobenzene skeleton (a structure in which a benzene ring is provided at both ends of the azo group) is preferably used. Such polymer materials can be divided into main chain structure and side chain structure, and various molecular designs are possible, so that not only the absorption coefficient, but also the sensitive wavelength range, response speed, record retention, etc. It is easy to adjust various physical properties required for hologram recording to desired values at a high level. An example of such an azo polymer is a polyester containing a repeating unit having an azobenzene skeleton in the side chain portion as shown in the following structural formula.

  The azo polymer is basically suitable for producing a rewritable hologram recording medium that can rewrite a hologram once recorded because the reaction by light irradiation is reversible.

  In addition to azopolymers, holographic recording materials having a structure showing an isomerization reaction can also be used. For example, xanthene dyes and fulgides represented by diarylethenes, spiropyrans, uranin, erythrosine B, eosin Y, etc. can also be used. is there.

  Note that the recording medium 28 can be used in combination with other materials other than the hologram recording material described above, and various additives, a binder resin, and the like can also be used in combination.

The thickness of the recording medium 28 is preferably in the range of 0.1 μm to 200 μm from the viewpoint of preventing bulkiness, and more preferably in the range of 10 μm to 30 μm in order to obtain high diffraction efficiency. The recording medium 28 can be manufactured by a known film forming method such as a hot press method, a spin coat method, a cast method, an application method using an applicator, a bar coater, or an edge coater. For example, when an azo polymer is used as a hologram recording material, a plate-shaped molded product is produced by injection molding, and then the plate-shaped molded product is sandwiched between a pair of releasable resin films and hot pressed under vacuum. By doing so, it is formed into a sheet shape. A sheet-like hologram recording material is peeled off from a resin film and used by being cut into small pieces of several mm square (for example, 8 mm square). The heating temperature is preferably a temperature equal to or higher than the Tg of the recording material, and the pressing pressure is preferably 0.01 to 0.1 t / cm ² . As the releasable resin film, for example, a polyethylene terephthalate (PET) film in which a silicone resin is coated on the surface as a release agent can be used.

  The protective film 62 is made of a resin film that is transparent and flexible with respect to laser light used for recording / reproduction. The protective film 62 may include an adhesive layer having adhesiveness, and the sheet-like recording medium 28 can be held on the adhesive layer. When the recording medium 28 can be sufficiently attached to the recording medium holding member 60 by pressure bonding, the adhesive layer is not required. However, when the recording medium 28 is thick or long-term stability is desired, the adhesive layer is formed on the protective film 62. It is preferable to have Further, instead of laminating with the protective film 62, a protective film for covering the recording medium 28 can be formed by applying a resin.

  From the viewpoint of preventing bulkiness, the thickness of the protective film 62 is preferably in the range of 1 μm to 200 μm, and within this range, the thinner the better. From the viewpoint of light utilization efficiency, the light transmittance of the protective film 62 is preferably 50% or more, and more preferably 80% or more. As such a protective film, “OPP tape (R)” manufactured by Nitto Denko Corporation can be used.

  The recording medium holding member 60 is not particularly limited in shape, and may be a cylindrical shape such as a can, a cube shape, a card shape, or the like.

The recording medium holding member 60 may be made of any material as long as the recording medium 28 can be attached, such as paper, metal, synthetic resin, and ceramic.
(Function)
Next, the operation of the hologram recording apparatus 10 of the present embodiment will be described.

  First, the recording medium 28 is arranged in the loading unit 30, and a pattern that transmits light is displayed on the spatial light modulator 22 (in this embodiment, the letter “X”).

  Next, a light beam is emitted from the laser light source 12, and the shutter 14 is opened for a predetermined time.

  The light beam emitted from the laser light source 12 reaches the light separation means 24 via the reflection mirror 16, the beam expander 18, the reflection mirror 20, and the spatial light modulator 22, and a part of the light beam is transmitted through the light separation means 24 to be signal light. Is irradiated to the recording medium 28 through the imaging optical system 26, and the other part is reflected by the light separation means 24 and irradiated to the recording medium 28 through the reflecting mirror 32 and the anamorphic optical system 34 as reference light. Is done.

  In the hologram recording apparatus 10 of the present embodiment, irradiation is performed on the recording medium so as to match the pattern of the reference light and the pattern of the signal light, and a hologram (letter “X” in the present embodiment) is recorded only on the irradiated portion. In other words, only the pattern portion becomes an image hologram, and unnecessary holograms are not recorded in portions other than the pattern portion. Therefore, as shown in FIG. 4, the contrast between the pattern portion 29 and the portion other than the pattern portion increases, and the pattern The portion 29 can be easily recognized, and the decoration effect can be improved.

  Further, in the hologram recording apparatus 10 of the present embodiment, the pattern displayed on the spatial light modulator 22 can be easily changed by a computer, so there is no need to produce an expensive hologram transfer foil ribbon or mask, The recorded recording medium 28 can be provided on demand at low cost, and the security and environmental problems of the prior art can be avoided.

  The light intensity of the signal light and the reference light irradiated on the recording medium 28 may be uniform. For example, as shown in FIG. 5, the intensity of the signal light may have a distribution ( In FIG. 5, the black portion is high in strength). Further, as represented by azopolymer, in a polarization-sensitive recording material exhibiting light-induced anisotropy, signal light can have a polarization distribution.

  In addition, after recording the hologram on the recording medium 28, the recording medium 28 on which the hologram is recorded may be attached to the recording medium holding member 60. After the recording medium 28 is attached to the recording medium holding member 60, the hologram is recorded. You may do it.

  The form of the recording medium 28 may be a film or a plate.

  Further, the recording medium 28 may have a reflective layer on the back surface side, and after recording a hologram on the transparent recording medium 28, a reflective layer may be provided.

In the present embodiment, the light beam from the laser light source 12 that has passed through the light separation means 24 is used as signal light, and the reflected light beam is used as reference light. However, the light separation means can be changed by changing the arrangement of the optical system. The light transmitted through 24 may be used as the reference light, and the reflected light may be used as the signal light.
[Second Embodiment]
Next, a hologram recording apparatus 10 according to a second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same structure as 1st Embodiment, and the description is abbreviate | omitted.

  As shown in FIG. 6A, in the hologram recording apparatus 10 of the present embodiment, the first spatial light modulator 36 and the first imaging optical system 38 are sequentially arranged on the light beam transmitting side of the light separating means 24. The reflecting mirror 32, the second spatial light modulator 40, and the second imaging optical system 42 are sequentially arranged on the light beam reflecting side.

  As shown in FIG. 6B, the first spatial light modulator 36 and the second spatial light modulator 40 are connected to the computer 25, respectively, and a pattern created by the computer 25 is displayed. .

Also in the present embodiment, as in the first embodiment, the signal light is incident on the recording medium 28 perpendicularly, and the reference light is incident on the signal light at an angle θ.
(Function)
Next, the operation of the hologram recording apparatus 10 of the present embodiment will be described.

  In the present embodiment, the pattern displayed on the first spatial light modulator 36 is displayed on the second spatial light modulator 40 so that the patterns of the signal light and the reference light match on the recording medium. The pattern is deformed by cos θ times only in one direction (in this embodiment, the direction corresponding to the vertical direction of the letter “X”).

  As a result, similarly to the first embodiment, the recording medium is irradiated with the pattern of the reference light and the pattern of the signal light.

Other functions and effects are the same as those of the first embodiment.
[Third Embodiment]
Next, a hologram recording apparatus 10 according to a third embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same structure as embodiment mentioned above, and the description is abbreviate | omitted.

  As shown in FIG. 7A, in the hologram recording apparatus 10 of the present embodiment, a λ / 2 wavelength plate 44 is disposed between the reflecting mirror 20 and the light separating means 24.

  In this embodiment, the light separating means 24 of the present embodiment uses a polarizing beam splitter that reflects a part of the incident light beam.

  On the light beam reflecting side of the light separating means 24, a reflecting mirror 32, a second spatial light modulator 40, a second imaging optical system 42, a reflecting mirror 46, a reflecting mirror 48, and a reflecting mirror 50 are arranged in this order. Yes.

  As shown in FIG. 7B, the second spatial light modulator 40 of the present embodiment can be moved in the optical axis direction by an actuator 66 controlled by the computer 25.

Further, the reflection mirror 50 of this embodiment is attached to an attitude control device 52 controlled by the computer 25, and the attitude control device 52 enables the reflection mirror 50 to move in the X1 direction of FIG. 7A. The reflection angle can be changed in the direction of the arrow φ, whereby the angle θ of the reference light with respect to the signal light can be changed.
(Function)
In the hologram recording apparatus 10 of the present embodiment, a pattern is formed on the second spatial light modulator 40 so that it matches the pattern of the signal light generated by the first spatial light modulator 36 and irradiated on the recording medium. While being displayed, the position of the second spatial light modulator 40, the position of the reflecting mirror 50, and the orientation are determined by the computer 25.

  In the above-described embodiment, the exposure is performed with the angle θ of the reference light with respect to the signal light fixed at a certain angle. However, in the present embodiment, the multiple exposure is performed by changing the angle θ from θ1 to θn by a predetermined angle. .

  The angle θ at the time of performing the multiple exposure is stored in the computer 25 in advance. In the first exposure, the second pattern is such that the pattern of the signal light matches the pattern of the reference light and the angle θ1. The first exposure is performed by changing the size of the pattern displayed on the spatial light modulator 40, the position of the second spatial light modulator 40, the position of the reflection mirror 50, and the orientation.

  Next, in the second exposure, the size of the pattern displayed on the second spatial light modulator 40 such that the angle θ2 (for example, a predetermined angle larger than θ1) is set, and the second spatial light modulator 40 The position, the position and orientation of the reflecting mirror 50 are changed, and the second exposure is performed.

  Thereafter, in the same manner, exposure is performed for the number of exposures (n times) preset in the computer 25.

  In order to change the angle θ, the position and orientation of the reflecting mirror 50 are changed. As a result, the optical path length changes, so that the second spatial light is matched so that the pattern of the reference light matches the pattern of the signal light. The position of the modulator 40 is changed. If the imaging magnification of the imaging optical system is different, a pattern that takes that into consideration is generated (by the way, the imaging magnifications of the first imaging optical system 38 and the second imaging optical system 42 are equal). When the height of the pattern displayed on the first spatial light modulator 36 is a and the angle of the reference light with respect to the signal light is θ, the height h of the pattern displayed on the second spatial light modulator 40 is H = a · cos θ).

  By performing multiple exposure as in the present embodiment, it is possible to make the hologram easy to see under environmental illumination and to improve the appearance of the hologram.

Here, as the diffusion plate 54, a transmission type diffusion plate in which at least one surface is roughened like rubbed glass can be used. For example, sand numbers # 240 to # 1500 of “Frost type diffusion plate” manufactured by Sigma Koki Co., Ltd. can be used.
[Fourth Embodiment]
Next, a hologram recording apparatus 10 according to a fourth embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same structure as embodiment mentioned above, and the description is abbreviate | omitted.

  In the present embodiment, a diffusion plate 54 that scatters a light beam is disposed between the second spatial light modulator 40 and the imaging optical system 42.

By disposing the diffuser plate 54, the reference light is scattered, and the same effect as multiple exposure can be obtained with one exposure, making it easy to see the hologram under ambient illumination and improving the appearance of the hologram. I can do it.
[Fifth Embodiment]
Next, a hologram recording apparatus 10 according to a fifth embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same structure as embodiment mentioned above, and the description is abbreviate | omitted.

  As shown in FIG. 9A, in the present embodiment, the light separation means 24 (polarization beam splitter) is arranged on the beam incident side of the second spatial light modulator 40, and the light separation means 24 and the first The reflection mirror 20 is arranged between the spatial light modulator 36.

  On the light beam incident side of the light separating means 24, a λ / 2 wavelength plate 44, a first dielectric multilayer mirror 55, a second dielectric multilayer mirror 56, and a reflection mirror 58 are arranged in this order.

  A first laser light source 12R is provided corresponding to the reflection mirror 58, and corresponding to the second laser light source 12G and the first dielectric multilayer mirror 55 corresponding to the second dielectric multilayer mirror 56. A third laser light source 12B is provided.

  The first laser light source 12R, the second laser light source 12G, and the third laser light source 12B have different wavelengths of emitted light beams. In this embodiment, the first laser light source 12R has a wavelength of 647 nm ( The second laser light source 12G emits a light beam having a wavelength of 532 nm (green), and the third laser light source 12B emits a light beam having a wavelength of 457 nm (blue).

  The reflection mirror 58 reflects the light beam emitted from the first laser light source 12 </ b> R toward the light separation unit 24.

  The second dielectric multilayer mirror 56 reflects the light beam emitted from the second laser light source 12G toward the light separating means 24 and reflects the light beam emitted from the first laser light source 12R. To Penetrate.

In addition, the first dielectric multilayer mirror 55 reflects the light beam emitted from the third laser light source 12B toward the light separating means 24, and the light beam emitted from the first laser light source 12R. And the light beam emitted from the second laser light source 12G is transmitted.
(Function)
In the hologram recording apparatus 10 of the present embodiment, exposure is performed in order with each laser light source (the order of the three colors is not particularly limited). If necessary, an optical system adjusting unit that corrects chromatic aberration may be used.

  As shown in FIG. 9B, a rainbow-colored hologram can be created by changing the intensity pattern of the signal light for each wavelength and performing multiple exposure.

(A) is a whole block diagram of the hologram recording apparatus according to the first embodiment, and (B) is a block diagram of a control system. (A) is sectional drawing which shows an example of the recording medium holding member which affixed the recording medium, (B) is a perspective view of the recording medium holding member shown to FIG. 2 (A). It is sectional drawing which shows the other example of the recording-medium holding member which affixed the recording medium. It is a figure of the recording medium which recorded the hologram with the hologram recording device of 1st Embodiment. It is explanatory drawing which shows light intensity distribution of signal light and reference light. (A) is a whole block diagram of the hologram recording apparatus which concerns on 2nd Embodiment, (B) is a block diagram of a control system. (A) is a whole block diagram of the hologram recording apparatus which concerns on 3rd Embodiment, (B) is a block diagram of a control system. (A) is a whole block diagram of the hologram recording apparatus which concerns on 4th Embodiment. (A) is the whole block diagram of the hologram recording apparatus which concerns on 5th Embodiment, (B) is explanatory drawing which shows intensity distribution of the signal light of each color. (A) is explanatory drawing which shows the recording method of the conventional hologram, (B) is a figure which shows the recording medium with which the hologram was recorded by the conventional method.

DESCRIPTION OF SYMBOLS 10 Hologram recording device 12 Laser light source 12R Laser light source 12G Laser light source 12B Laser light source 18 Beam expander 22 Spatial light modulator 24 Light separation means 26 Imaging optical system 28 Recording medium 29 Pattern part 34 Anamorphic optical system 36 Spatial light modulator 38 Imaging Optical System 40 Spatial Light Modulator 44 λ / 2 Wave Plate 52 Attitude Control Device 54 Diffusion Plate 55 Dielectric Multilayer Film Mirror 56 Dielectric Multilayer Film Mirror 60 Recording Medium Holding Member 66 Actuator

Claims (10)

A hologram recording apparatus that irradiates a photosensitive recording medium with signal light and reference light, and records a hologram on the recording medium by interference between the signal light and the reference light,
Signal light irradiation means for irradiating the recording medium with signal light;
Reference light irradiating means for irradiating the reference light only to a portion of the recording medium to which the signal light is irradiated;
And at least one of the signal light and the reference light is intensity-modulated . A light source that emits a light beam;
A spatial light modulator for modulating the light beam emitted from the light source;
Light separation that passes through a part of the light beam via the spatial light modulator to be either signal light or reference light and reflects the other part to be either signal light or reference light Means,
The reference light is disposed on the reference light emitting side of the light separating means, and the reference light is irradiated so that only the portion of the recording medium irradiated with the signal light corresponds to the incident angle to the recording medium. An optical system to deform,
The a hologram recording apparatus according to claim 1, characterized in that. The hologram recording apparatus according to claim 2, wherein the optical system includes an anamorphic optical system, and the reference light is irradiated to the recording medium through the anamorphic optical system. A light source that emits a light beam;
A light separating unit that transmits a part of the light beam emitted from the light source to be one of signal light and reference light and reflects the other part to be either the signal light or reference light; ,
A first spatial light modulator disposed on the signal light emitting side of the light separating means and generating a signal light irradiation pattern;
A second spatial light modulator disposed on the reference light emitting side of the light separating means and generating an irradiation pattern of the reference light;
The hologram recording apparatus according to claim 1, further comprising:   The hologram recording apparatus according to claim 3, further comprising a changing unit that changes an angle of the reference light with respect to the signal light.   6. The hologram recording apparatus according to claim 3, further comprising a diffusing unit configured to diffuse the incident light beam on a reference light emitting side of the light separating unit.   The hologram recording apparatus according to claim 3, wherein the light source emits light beams having a plurality of different wavelengths.   A recording medium on which a hologram is recorded by the hologram recording apparatus according to claim 1.   A recording medium holding member carrying the recording medium according to claim 8. A hologram recording method of irradiating a photosensitive recording medium with signal light and reference light, and recording a hologram on the recording medium by interference between the signal light and the reference light,
A hologram recording method , wherein reference light is irradiated only to a portion of signal light irradiated on the recording medium , and intensity modulation is applied to at least one of the signal light and the reference light .

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