JP2006337462A - Diffusive laminate, manufacturing method of directive diffuser and directive diffuser - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diffusive laminate which reduces defects upon duplication by making it possible to perform the adhesion and release smoothly between an original plate and photosensitive material and is capable of manufacturing a directive diffuser having high diffusiveness by improving the diffusiveness of the original plate. <P>SOLUTION: In the diffusive laminate, relief processing is performed on one side surface of a film having no birefringence and a releasing layer, composed of a releasing agent and fillers which have refractive index different from that of the releasing agent and are dispersed in the releasing agent is laminated on the other side surface of the film. This invention also provides a manufacturing method of a directive diffuser using the diffusive laminate, and the directive diffuser. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a method of manufacturing a directional diffuser having directivity that diffuses only light incident from a specific direction and allows other light to pass through.
In particular, in a duplicating method in which a directional diffuser having a calasilencon-like region structure having a different refractive index is adhered to a diffusive laminate and a photosensitive material, and recording is performed with a laser beam.
The present invention relates to a technique for making it possible to smoothly perform close contact and release between a diffusive laminate, which is an original plate, and a photosensitive material, and to improve the diffusion performance of a produced directional diffuser.

  Directional diffusers that diffuse only light incident from a specific direction and allow light incident from other directions to pass through have been used in fields such as liquid crystal panels.

  As one of such directional diffusers, for example, there is known a directional diffuser having a structure like a kalashenkon, in which a large number of parallel columnar regions having different refractive indexes are formed as shown in FIG. Yes.

  In the directional diffuser having such a structure, for example, as shown in FIG. 7, light incident from substantially the same direction as the direction of the parallel columnar region is light 2 incident on the region 1 having a high refractive index. Since the light 4 that has been emitted through only 1 and entered the region 3 having a low refractive index is emitted only through the region 3 having a low refractive index, the emitted light has a large level in each adjacent region. Because of the phase difference, it diffuses strongly.

  On the other hand, for example, as shown in FIG. 8, the light incident from different directions is a region in which both the light 5 incident on the high refractive index region 1 and the light 6 incident on the low refractive index region 3 have a high refractive index. It is injected after passing through several low areas. For this reason, there is almost no phase difference between adjacent regions, so that they pass almost without being scattered. For this reason, it becomes a directional diffuser that diffuses only light incident from a specific direction and allows light incident from other directions to pass through. A directional diffuser having such a structure is known from Patent Document 1.

  As a method for manufacturing a directional diffuser having such a structure, the applicants have proposed the following method in a patent application.

  First, a light-sensitive material having tackiness is recorded on the base film so that a difference in exposure amount is recorded as a difference in refractive index. Then, a diffusion film having no birefringence is laminated thereon to produce a film in which the photosensitive material 7 is sandwiched between the base film 8 and the diffusive film 9 as shown in FIG. For example, OMNIDEX 352 manufactured by DuPont is considered as a photosensitive material used in this case, and as a diffusible film having no birefringence, a film provided with a non-stretched polycarbonate surface relief is considered.

  Using this sandwich-shaped film, for example, a parallel laser beam 11 is irradiated from the diffusion film 9 side while feeding the film 10 by a system as shown in FIG.

At this time, the laser light that has passed through the diffusion film 9 forms a speckle pattern by interference. A speckle pattern is a bright and dark speckle pattern that occurs when light with good coherence is scattered or reflected or transmitted by a rough surface. It happens.

In general, the average length t of the speckle pattern with respect to the (central) traveling direction of the diffused light is t = It is known that the average size d of the speckle pattern in the direction perpendicular to 4.0λ (F / D) ² (Equation 1) can be calculated by d = 1.2λF / D (Equation 2).

  From this calculation formula, it can be seen that unless the diffusibility of the diffusible film is particularly large, the speckle pattern has an elongated shape with respect to the (central) traveling direction of the diffused light. For example, when a laser beam having a wavelength of 355 nm is used and diffused light is diffused light having a spread of about 10 cm by 50 cm, t = 35.5 μm and d = 2.13 μm. The shape is elongated with respect to the traveling direction.

  As can be seen from this, the parallel laser beam 11 that has passed through the diffusion film 9 is formed as a speckle pattern 12 that is elongated in the traveling direction of the incident laser beam 11 as schematically shown in FIG. It is injected. For this reason, as shown in FIG. 12, a pattern in which the speckle pattern is divided by the thickness of the photosensitive material 7 is recorded on the photosensitive material 7, and as a result, a kalashenkon pattern is recorded. Become.

  When the diffusive film 9 is peeled off from the photosensitive material 7 on which the pattern of the kalashenkon pattern is recorded in this way and the photosensitive material 7 is developed, a large number of parallel columnar regions having different refractive indexes are formed. Thus, it is possible to obtain a directional diffuser having a structure like a kalashenkon.

  This method is convenient because a directional diffuser can be manufactured with a relatively simple apparatus and a seamless one can be obtained.

  By the way, the characteristics of the directional diffuser that can be produced by this method depend on the optical characteristics of the diffusible film that is not birefringent, which is used as an original plate. There were only two problems as described below because there was only a conductive film.

  The first is that the photosensitive material partially remains on the diffusive film in the step of peeling the diffusive film from the photosensitive material after exposure. When such a phenomenon occurs, not only a defect occurs in the directional diffuser as a product, but also a diffusive film as a replication master is destroyed, which is a serious problem in terms of productivity and cost.

  Second, it is difficult to make the directional diffuser sufficiently diffuse. The pattern produced by this method depends on the diffusivity of the original, but the surface diffusivity alone has a limit on the level of diffusivity, so that the directional diffuser to be produced has sufficient diffusibility. I couldn't make it.

  This was the same when using a mask-like film having a different transmittance as in Patent Document 2.

The patent literature is as follows.
JP 2000-171619 A JP 2004-283968 A

As described above, in the manufacture of a conventional directional diffuser, in the process of peeling the diffusible film from the photosensitive material after exposure, the photosensitive material partially remains on the diffusive film, and the product and the duplication master are no longer used. And the problem of becoming
Since the diffusibility of the diffusible film that can be used as the original plate is low, the directional diffuser that can be produced cannot have sufficient diffusibility.

  The present invention has been made in order to solve such problems, and by making it possible to smoothly close and release the original plate and the photosensitive material, it is possible to reduce defects generated during copying. The aim is to increase the diffusibility of the original plate so that a highly diffusive directional diffuser can be manufactured.

In order to solve the above-described problems, in the invention of claim 1, as an original plate for manufacturing a directional diffuser,
One surface relief treatment of a film having no birefringence is performed, and a release layer in which a release agent and a filler having a refractive index different from that of the release agent are dispersed is laminated on the other surface. The present invention proposes a diffusive laminate that replaces the conventional diffusive film characterized by the above.

In the invention of claim 2, a surface relief diffusion layer is formed on one surface of a film in which a film material having no birefringence and a filler having a refractive index different from that of the film material are dispersed, and a release layer is formed on the other surface. The present invention proposes a diffusive laminate that replaces a conventional diffusive film characterized in that is laminated.

In the invention of claim 3,
The diffusable laminate according to claim 1 or 2, wherein the film material is unstretched polycarbonate.

In the invention of claim 4, using the diffusive laminate as described in claims 1, 2, and 3 as an original plate,
The surface of the diffusive laminate according to any one of claims 1 to 3 on which the release layer is laminated and the photosensitive material whose refractive index changes upon exposure and which is sticky are adhered and laminated together. We propose a method of manufacturing a directional diffuser characterized by irradiating a laser beam from the side of the laminate. By irradiating a laser beam from the side of the diffusive laminate, the diffusive material is incorporated into the photosensitive material. A method for producing a directional diffuser has been proposed in which a directional diffuser is formed by recording a speckle pattern of laser light generated in a laminate as a refractive index distribution. In particular, it is also conceivable to irradiate a laser beam while bringing a photosensitive material into close contact with the release layer side of the diffusive laminate and transporting them.

  The invention of claim 5 proposes a directional diffuser manufactured using the method of claim 4.

In the diffusive laminate of the present invention, a release layer is laminated on one surface of a film that does not have birefringence, so that the diffusive laminate as the original plate and the photosensitive material can be smoothly adhered and released. By doing so, the original plate lasts longer while reducing the defects generated at the time of duplication.

  Moreover, by putting a filler in the release layer or film, the diffusibility of the original plate can be increased, and the directivity of the directional diffuser to be duplicated can be increased.

  Hereinafter, the diffusive laminate of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic view showing an embodiment of the diffusive laminate according to claim 1 of the present invention.

  In this figure, a release layer 14 is coated on the surface opposite to the surface-relieved surface of the non-birefringent film 13 whose surface is surface-relieved, and the release layer is in the release layer. The filler 15 different from the refractive index of the layer is dispersed.

  In such a diffusive laminate, for example, a filler having a refractive index different from that of a release agent material is dispersed in a release agent material dissolved in a solvent or the like, and this liquid is conventionally used. It can be obtained by coating on a film having no birefringence.

  As the film having no birefringence, for example, a polycarbonate film produced by extrusion molding can be used, and as the release agent, for example, a silicon-based UV curable resin or a water-soluble resin can be used. A release agent or the like can be used. Moreover, as a filler, Sekisui Chemical technopolymer etc. can be used, for example.

  When a directional diffuser is manufactured using such a diffusive laminate as an original plate, as shown in FIG. 2, a photosensitive material 16 having an adhesive property such that a difference in exposure amount is recorded as a difference in refractive index. The diffusive laminate that has been coated and laminated on the film is adhered to the release layer 14 side, and the laser beam is irradiated from the surface diffusion layer side by the system of FIG. After the pattern is recorded on the photosensitive material, the photosensitive material is peeled off from the diffusive laminate.

  In this way, as shown in FIG. 3, the laser light 17 is further diffused by the release layer 14 and the filler 15 after being diffused on the surface relief-treated surface of the film 13 that has undergone surface relief treatment and has no birefringence. Therefore, the diffused light spreads over a wider range than the conventional diffusive laminate.

  For this reason, the speckle pattern formed by this diffusive laminate has a smaller F / D value in the equation (2) and becomes finer in the plane direction. Therefore, since a finer refractive index modulation pattern is recorded on the photosensitive material 16, a highly diffusive directional diffuser can be obtained.

  In addition, since the photosensitive material 16 is in close contact with the release layer 14 having good releasability, there is a problem that the photosensitive material partially remains on the diffusive laminate in the step of peeling the photosensitive material after recording the pattern. Does not occur.

  FIG. 4 is a schematic view showing an embodiment of the diffusive laminate according to claim 2 of the present invention.

  In this figure, a filler 19 having a refractive index different from the refractive index of the film material is dispersed in a film 18 that has been subjected to surface relief treatment that does not have birefringence and does not have birefringence, and a release layer 20 is formed on the surface thereof. It has a coated structure.

Such a diffusive laminate can be obtained, for example, by mixing a filler in a material to produce a film and then applying a release layer to the film.

  When such a film is used as an original plate, as shown in FIG. 5, the laser beam 21 is diffused on the relief-treated surface of the film 18 that is not surface-relieved and has no birefringence, and then a filler. 19 is further diffused, so that the diffused light spreads over a wider range than the conventional diffusive laminate.

  For this reason, as in the case of the diffusive laminate of claim 1, a highly diffusive directional diffuser can be obtained, and no problem occurs when releasing the photosensitive material.

  FIG. 1 is a schematic view showing an embodiment of the diffusive laminate according to claim 1 of the present invention.

  In this figure, a release layer 14 is coated on the surface opposite to the surface-relieved surface of the non-birefringent film 13 whose surface is surface-relieved, and the release layer 14 is applied to the release layer. The filler 15 different from the refractive index of the mold layer is dispersed.

  Such a diffusive laminate, for example, disperses a release agent material and a refractive index 1.6 filler at a ratio of 5% by weight in a release agent material having a refractive index of 1.5 dissolved in a solvent or the like. In addition, this liquid can be obtained by coating a film having no birefringence as conventionally used by a thickness of 5 μm.

  As the film having no birefringence, for example, a polycarbonate film (thickness: 100 μm) produced by extrusion molding can be used, and as the release agent, for example, a silicon-based UV curable resin is used. Alternatively, a water-soluble release agent (trade name: Saimak, manufactured by Toa Gosei Co., Ltd.) can be used. Moreover, as a filler, Sekisui Chemical technopolymer (made by Sekisui Chemical Co., Ltd.) etc. can be used, for example. When a directional diffuser is duplicated using such a diffusive laminate as an original plate, as shown in FIG. 2, the photosensitive material 16 having adhesiveness such that a difference in exposure amount is recorded as a difference in refractive index. OMNIDEX 352 having a thickness of 20 μm is applied and adhered on the release layer 14 side of the diffusive laminate, and laser light having a wavelength of 355 nm is applied from the surface diffusion layer side by the system shown in FIG. After the pattern is recorded on the photosensitive material by irradiation, the diffuser is manufactured in a process of peeling the photosensitive material.

  In this way, as shown in FIG. 3, the laser light 17 is further diffused by the release agent layer 14 and the filler 15 after being diffused on the surface relief treated surface of the film 13 that has been surface relief-treated and does not have birefringence. Since it is diffused, it becomes diffused light that spreads over a wider range than the conventional diffusive laminate.

  For this reason, the speckle pattern formed by this diffusive laminated body has a value of F / D in (Equation 2) that is reduced from the conventional 5.5 to 2.5 of the present embodiment, and is reduced in the plane direction. On the other hand, it becomes finer. Therefore, since a finer refractive index modulation pattern is recorded on the photosensitive material 16, a highly diffusive directional diffuser can be obtained.

  In addition, since the photosensitive material 16 is in close contact with the release layer 14 having good releasability, there is a problem that the photosensitive material partially remains on the diffusive laminate in the step of peeling the photosensitive material after recording the pattern. Does not occur.

As shown in FIG. 4, a filler 19 having a refractive index different from the refractive index of the film material is dispersed in a film 18 having a surface relief treatment having no birefringence, and a release layer 20 is coated on the surface thereof. It becomes the composition.

  Such a diffusive laminate, for example, after producing a filler in polycarbonate by extrusion molding so that a relief on one surface is formed so that the thickness of the film finally becomes 100 μm, This film can be obtained by coating a release layer made of a silicon-based UV resin by a thickness of 5 μm.

  When such a diffusive laminate is used as an original plate of a photosensitive material having a thickness of 29 μm, the laser light 21 having a wavelength of 355 nm is subjected to the relief processing of the surface relief-treated film 18 as shown in FIG. Since it is further diffused by the filler 19 after being diffused on the surface, it becomes diffused light spreading in a wider range than the conventional diffusive laminate.

  For this reason, as in the case of the diffusive laminate of claim 1, a highly diffusive directional diffuser can be obtained, and no problem occurs when releasing the photosensitive material.

  By using the diffusive laminate of the present invention as an original plate, a directional diffuser used in a liquid crystal panel or the like can be produced stably and with high performance. There is a lot of potential in producing.

It is a general | schematic perspective view which shows an example of a diffusable laminated body. It is a general | schematic perspective view which shows the state of an original and a photosensitive material at the time of manufacture of the directional diffuser of this invention. It is a general | schematic perspective view for demonstrating increasing diffusibility with the diffusable laminated body of this invention. It is a general | schematic perspective view which shows an example of another diffusable laminated body of this invention. It is a general | schematic perspective view for demonstrating increasing diffusibility with the diffusable laminated body of FIG. It is a schematic perspective view which shows an example of a structure of a directional diffuser. It is a general | schematic perspective view for description in which the film of the structure of FIG. 6 represents directional diffusion. It is a general | schematic perspective view for description in which the film of the structure of FIG. 6 represents directional diffusion. It is a general | schematic perspective view which shows the state of an original and a photosensitive material at the time of the conventional directional diffuser manufacture. It is a general | schematic process drawing which shows the replication system of a directional diffuser. It is a general | schematic perspective view which shows an example of the speckle pattern by the conventional diffusive laminated body. It is a general | schematic perspective view which shows the pattern recorded on a photosensitive material by a speckle pattern.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High refraction area 2 Light 3 Low refraction area 4 Light 5 Light 6 Light 7 Photosensitive material 8 Base film 9 Diffusion film 10 Film 11 Laser beam 12 Speckle pattern 13 Film without birefringence 14 Release layer 15 Filler 16 Photosensitive material 17 Laser light 18 Film without birefringence 19 Filler 20 Photosensitive material 21 Laser light 22 Light diffused by surface relief 23 Light further diffused by filler 25 Side with surface relief 26 Developing device 27 Unwinding roll 28 Winding roll

Claims (5)

  One surface relief treatment of a film having no birefringence is performed, and a release layer in which a release agent and a filler having a refractive index different from that of the release agent are dispersed is laminated on the other surface. A diffusive laminate characterized by comprising:   A surface relief diffusion layer is formed on one surface of a film in which a filler having a refractive index different from that of the film material and the film material having no birefringence is dispersed, and a release layer is laminated on the other surface A diffusive laminate characterized by the above.   The diffusive laminate according to claim 1 or 2, wherein the film material is unstretched polycarbonate.   The surface of the diffusive laminate according to any one of claims 1 to 3 on which the release layer is laminated and the photosensitive material whose refractive index changes upon exposure and which is sticky are adhered and laminated together. A method for producing a directional diffuser, wherein the laser beam is irradiated from the laminated body side.   5. A directional diffuser manufactured using the method of claim 4.

Images