JP5494912B2 - Hologram production method - Google Patents

Description

The present invention relates to a hologram manufacturing method , and more particularly to a hologram manufacturing method using ultraviolet light.

  Conventionally, various anti-counterfeiting measures have been taken for goods that require anti-counterfeiting as well as authentication such as cards such as cash cards, credit cards, check cards, cash vouchers, identification cards, important documents, etc. ing. For example, in a credit card, a rainbow hologram composed of a relief hologram having a metal reflection layer is provided on the surface of the card as an authentication structure for visually checking the authenticity of the card. Such a hologram recording apparatus is disclosed in Patent Document 1.

  In general, as a feature of holograms, Lippmann holograms (volume type / reflection type holograms) have high angle selectivity and wavelength selectivity, and transmission type holograms (volume type and surface relief type) produce large color dispersion. It is well known that many substances have light absorption and fluorescence characteristics in the ultraviolet region.

Japanese Patent Publication No. 60-30948 Special table 2007-538293 gazette Japanese Patent No. 2849021

  However, in the conventional technology, when the hologram recording wavelength is set to ultraviolet light, if the subject material has characteristics such as ultraviolet absorption and fluorescence, it becomes difficult to record as a hologram.・ There were great restrictions on materials. This was particularly noticeable in paper containing fluorescent coloring materials and films that absorb ultraviolet rays. As a case where recording with ultraviolet rays is necessary, for example, there is a case where a material for HPDLC (holographic polymer dispersed liquid crystal) that records using an ultraviolet laser as disclosed in Patent Document 2 is used.

The present invention has been made in view of such problems of the prior art, and an object of the present invention is to provide a hologram manufacturing method that eliminates the limitation of a material that is a subject when recording a hologram using ultraviolet light. It is.

The hologram production method of the present invention that achieves the above object irradiates visible light as object illumination light to a subject arranged on the first surface side of the first photosensitive material, and uses the object light emitted from the subject as the first light. The light is incident on the photosensitive material from the first surface side, and at the same time, the first photosensitive material has the same wavelength as the object light composed of parallel light or substantially parallel light from the same first surface side as the object light incident side. Reference light is incident at a predetermined incident angle to produce a first hologram, the first hologram and the second photosensitive material are arranged side by side, and are arranged on the side opposite to the first surface of the first hologram. The step of making the second illuminating light and the reproduction light of the first hologram incident on the second photosensitive material by making the reproduction illumination light composed of ultraviolet light having a predetermined wavelength from the surface, thereby producing a second hologram And having To.

  Further, a back layer that absorbs ultraviolet light is disposed on the side opposite to the first hologram of the second photosensitive material.

  Further, a material that absorbs ultraviolet rays is used as the subject.

  In addition, a material that emits fluorescence by ultraviolet rays is used as the subject.

  According to the present invention, reflected light or diffracted light from a subject in visible light can be recorded on a material sensitive to ultraviolet light. Thereby, the restriction | limiting of the substance and material used as a to-be-photographed object at the time of recording a hologram using an ultraviolet light can be eliminated.

It is a figure which shows the method of producing the hologram original plate of this embodiment. It is a figure which shows the method of reproducing | regenerating the hologram original plate of this embodiment. It is a figure which shows the method of reproducing | regenerating the hologram original plate of this embodiment by ultraviolet light. It is a figure which shows the method to duplicate the hologram of this embodiment. It is a figure which shows the method to reproduce | regenerate the duplicate hologram of this embodiment. It is a figure which shows the method of reproducing | regenerating the replicated hologram of this embodiment by ultraviolet light.

  Hereinafter, a hologram according to the present invention will be described with reference to the drawings.

  First, a method for producing a transmission hologram master using visible light, which is a premise of the present invention, will be described.

  FIG. 1 is a diagram showing a method for producing a transmission hologram master with visible light. In the present embodiment, as shown in FIG. 1, to the scattering plate 0 that is a subject arranged on the first surface 1a side of the first hologram recording photosensitive material 1 having sensitivity to visible light such as a photopolymer or a silver salt material. The first object light 12 having a predetermined wavelength emitted from the scattering plate 0 is incident on the first hologram recording photosensitive material 1 from the first surface 1a side and simultaneously with the first hologram. The first reference light 13 having the same first wavelength λ as the first object light 12 made of parallel light or substantially parallel light is applied to the recording photosensitive material 1 from the same first surface 1 a side as the incident side of the first object light 12. The light is incident at a predetermined first incident angle α.

  Thus, the 1st object light 12 and the 1st reference light 13 interfere by making the 1st object light 12 and the 1st reference light 13 inject into the photosensitive material 1 for a 1st hologram recording. Thereafter, the first hologram recording photosensitive material 1 is post-processed to produce a first hologram 1 '.

  In the present embodiment, in order to produce such a transmission type first hologram 1 ′, the photopolymer of Example 1 of Patent Document 2 was used as the hologram sensitive material 1 for green. Further, the laser and wavelength used for photographing are 532 nm of the DPSS laser.

  FIG. 2 is a diagram for explaining a process of reproducing a transmission hologram master recorded with visible light. The first reproduction illumination light 21 that travels in the opposite direction to the first reference light 13 and has the same wavelength as the first wavelength λ at the time of recording with respect to the produced first hologram 1 ′ is angle α from the side opposite to the first surface 1a. 1 diffracts the first reproduction light 22 traveling in the opposite direction to the object light 3 in FIG. 1, and forms a first reproduction image 20 on the first surface 1a side.

  FIG. 3 is a diagram for explaining a process of reproducing the first hologram 1 ′ with ultraviolet light having the second wavelength λ ′. By causing the second reproduction illumination light 31 traveling in the opposite direction to the first reference light 3 at a second incident angle β different from the first reference light 13 shown in FIG. 2 from the opposite side to the first surface 1a. The second reproduction light 32 is diffracted, and a second reproduction image 30 is formed on the first surface 1a side. β is preferably the Bragg angle at the second wavelength λ ′ of the first hologram 1 ′.

  Thus, the first hologram 1 'can be reproduced by visible light and ultraviolet light. However, since the first hologram recording photosensitive material 1 for producing the first hologram 1 ′ uses a material (sensitizing dye) that enhances the reaction promoting energy of visible light, the first hologram 1 ′ Is colored, dark and inferior in transparency.

  For this reason, when a recording material having an absorption wavelength in visible light as used when the first hologram 1 ′ is recorded is used as a master for the first hologram 1 ′, the copied hologram is It is dark and inferior in transparency.

  Therefore, the produced first hologram 1 ′ is used as a master, and the hologram material having sensitivity to the ultraviolet light is duplicated by the ultraviolet light having the second wavelength λ ′. This is because the ultraviolet material does not use a sensitizing dye and therefore absorbs less by the dye. Hereinafter, the process of duplicating will be described.

  FIG. 4 is a diagram for explaining a process of copying to the second hologram recording photosensitive material 2 having sensitivity to ultraviolet light.

  First, the second hologram recording photosensitive material 2 having sensitivity to the second wavelength λ ′ is vacuum-injected into a liquid crystal glass cell 6 whose inner surface is coated with a transparent electrode, and is applied to the back layer 7 that absorbs ultraviolet light. Adhesion is made through the index matching liquid 8.

  Subsequently, on the opposite side of the back layer 7 side of the second hologram recording photosensitive material 2, the first surface 1 a is directed to the second hologram recording photosensitive material 2, and the first hologram 1 ′ is passed through the index matching liquid 8. Adhere.

  Next, as in FIG. 3, when the second reproduction illumination light 31 that is ultraviolet light having the second wavelength λ ′ is irradiated to the first hologram 1 ′ at the second angle β, the second reproduction light 32 (not shown) is diffracted. Then, the second reproduction light 32 enters the second hologram recording photosensitive material 2 as the second object light 32 ′ (not shown), and the zero-order light of the second reproduction illumination light 31 is the second reference light 31 ′ (not shown). As incident and interfere. Thereafter, the second hologram recording photosensitive material 2 is post-processed to produce a second hologram 2 '.

  Thus, the HPDLC material described in Patent Document 1 was used as the second hologram recording photosensitive material 2 for duplicating the transmission hologram. The laser and wavelength used for imaging are 363.8 nm of Ar laser. Blackboard glass was used as the back layer 7.

  FIG. 5 is a diagram for explaining a process of reproducing a transmission hologram replicated with ultraviolet light with visible light.

  The produced second hologram 2 ′ is irradiated from the first surface 2 a side with the third reproduction illumination light 41 having the first wavelength λ and the first angle α from the same direction as the second reference light 31 ′ (not shown). The third reproduction light 42 is diffracted to the side opposite to the surface 2 a, and the original subject image can be reproduced as the third reproduction image 40. Further, by applying a voltage to the liquid crystal cell, it is possible to control the presence or absence of diffraction, which is a feature of HPDLC.

  FIG. 6 is a diagram for explaining a process of reproducing a transmission hologram replicated with ultraviolet light with ultraviolet light.

  The produced second hologram 2 ′ is irradiated with the fourth reproduction illumination light 51 having the second wavelength λ ′ from the same direction as the second reference light 31 ′ (not shown) and the second wavelength λ ′ from the first surface 2a side. The fourth reproduction light 52 can be diffracted to the opposite side of the first surface 2 a and the original subject image can be reproduced as the fourth reproduction image 50. Further, by applying a voltage to the liquid crystal cell, it is possible to control the presence or absence of diffraction, which is a feature of HPDLC.

  According to the present embodiment, reflected light or diffracted light from a subject in visible light can be recorded on a material sensitive to ultraviolet light. Thereby, the restriction | limiting by the material by recording a hologram using an ultraviolet light can be eliminated.

  As described above, the hologram and the hologram manufacturing method of the present invention have been described based on the embodiments. However, the present invention is not limited to these embodiments, and various modifications are possible.

0 ... Scatter plate (subject)
DESCRIPTION OF SYMBOLS 1 ... Photosensitive material 1 'for 1st hologram recording ... 1st hologram 2 ... 1st hologram recording photosensitive material 2' ... 2nd hologram 6 ... Glass cell 7 for liquid crystal ... Back layer 8 ... Index matching liquid 11 ... Object illumination light DESCRIPTION OF SYMBOLS 12 ... Object light 13 ... 1st reference light 20 ... 1st reproduction image 21 ... 1st reproduction illumination light 22 ... 1st reproduction light 30 ... 2nd reproduction image 31 ... 2nd reproduction illumination light 31 '... 2nd reference light 32 ... second reproduction light 32 '... second object light 40 ... third reproduction image 41 ... third reproduction illumination light 42 ... third reproduction light 50 ... fourth reproduction image 51 ... fourth reproduction illumination light 52 ... fourth reproduction light

Claims (4)

Visible light is irradiated as object illumination light to the subject disposed on the first surface side of the first photosensitive material, and the object light emitted from the subject is incident on the first photosensitive material from the first surface side, and at the same time The reference light having the same wavelength as the object light composed of parallel light or substantially parallel light is incident on the first photosensitive material from the same first surface side as the object light incident side at a predetermined incident angle. Producing one hologram;
The first hologram and the second photosensitive material are arranged side by side, and the reproduction illumination light made of ultraviolet light having a predetermined wavelength is incident from a surface opposite to the first surface of the first hologram, Making the reproduction illumination light and the reproduction light of the first hologram incident on a second photosensitive material to produce a second hologram;
A method for producing a hologram, comprising: In the step of producing the second hologram,
2. The hologram manufacturing method according to claim 1, wherein a back layer that absorbs ultraviolet light is disposed on a side of the second photosensitive material opposite to the first hologram. The hologram manufacturing method according to claim 2, wherein a material that absorbs ultraviolet rays is used as the subject. The hologram production method according to claim 2, wherein a material that emits fluorescence by ultraviolet rays is used as the subject.

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