JP2007030394A - Optical structure, its manufacturing method and displaying apparatus provided with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical structure enable to exhibit an advanced optical function and being made at a low cost and also being superior in a mass productivity, and a displaying apparatus provided with the structure. <P>SOLUTION: A plastic film substrate 1 in this invention comprises a coloring layer 3 formed on the surface of a film 2 transparent to a light in a visible range, wherein a plurality of an aperture part 4 is formed as a matrix by selectively removed by a laser light on the coloring layer 3 and a part of the surface of the plastic film 2 is made an exposed surface 5 by these of the aperture part 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical structure, a method for manufacturing the same, and a display device including the same, and more particularly, a black matrix such as a liquid crystal display (LCD), a plasma display panel (PDP), or an organic electroluminescence display (organic EL). An optical structure that can be suitably used for a film substrate, a projector screen, a rear projection television screen, a microlens array, and the like, and can exhibit a high degree of optical functions, and is inexpensive and excellent in mass productivity. The present invention relates to a manufacturing method and a display device including the same.

  Conventionally, in a display device having a black matrix such as a liquid crystal display (LCD), a plasma display panel (PDP), an organic electroluminescence display (organic EL), or a video device such as a projector (PJ) or a rear projection television (RPTV) However, glass substrates have been used exclusively from the viewpoint of high transparency, mechanical strength, etc., but in recent years, in applications that require such high transparency, transparent glass substrates have been used instead of conventional glass substrates. Plastic materials have been used (see Non-Patent Document 1).

The reason is that the plastic material is lightweight, rich in flexibility, hard to break, and easy to process. Therefore, the liquid crystal display (LCD), plasma display panel (PDP), rear projection television (RPTV) It is because it becomes a big advantage in manufacturing etc.
For the above reasons, the range of use of transparent plastic materials is expanding in many industrial fields.
Supervised by Fumio Ide, “Optical Film for Display”, CMC Publishing Co., Ltd., published on February 29, 2004

By the way, although it is a transparent plastic material whose range of use has expanded in many fields in this way, it is generally inferior in heat resistance compared to glass, so deformation and breakage occur during the heating process. There was a problem that it was easy.
Therefore, there is a case where a processing method and a processing apparatus that have been developed on the premise that a glass substrate is conventionally used cannot be applied.
Thus, it has been desired to develop an optical structure that exhibits the target optical function while taking advantage of the plastic material, and a method for manufacturing the same.

  In addition, a photolithographic technique using a photosensitive resin or the like is used for an optical member such as a black matrix or a microlens array that needs to form a pattern on the surface of a transparent material in order to add an optical function. In many cases, this photolithography technique has a problem that the manufacturing cost increases because it includes a plurality of steps such as exposure, development, and etching.

  The present invention has been made in order to solve the above-described problems, and is capable of expressing a high-level optical function, and is inexpensive and excellent in mass productivity, a manufacturing method thereof, and the same An object is to provide a display device provided.

  As a result of intensive studies to solve the above problems, the inventors of the present invention intermittently or continuously apply laser light having a center wavelength of 250 nm or more and 600 nm or less to a colored layer formed on a transparent plastic substrate. When the colored layer is selectively removed by irradiation, the present inventors have found that a high-level optical function is expressed in a transparent plastic substrate, and the present invention has been completed.

That is, the optical structure of the present invention is characterized in that a colored layer is formed on a base material made of a light-transmitting organic polymer, and this colored layer is selectively removed by laser light.
A modified region in which a part of one main surface of the substrate is exposed as a result of selective removal of the colored layer, and a plurality of flat cavities are irregularly formed in the region of the exposed surface and in the substrate. Is preferably formed.
A plurality of locations on the one principal surface may be exposed surfaces, and the modified region may be formed in the region of one or more exposed surfaces of these exposed surfaces and in the substrate.

An intermediate layer having translucency is formed between the base material and the colored layer, and a part of one main surface of the intermediate layer is exposed by selective removal of the colored layer, and within the region of the exposed surface In addition, it is preferable that a modified region in which a plurality of flat cavities are irregularly formed is formed in the intermediate layer.
A plurality of locations on the one principal surface may be exposed surfaces, and the modified region may be formed in the region of one or more of the exposed surfaces and in the intermediate layer.

Each of the exposed surfaces may be connected to at least one adjacent exposed surface.
The exposed surface is preferably a curved surface.
The modified region preferably has a spherical shape, a polyhedron shape, or a spindle shape.
An intermediate layer having translucency may be formed between the base material and the colored layer.
An upper layer having translucency may be provided on one or both of the colored layer and the exposed surface.

In the method for producing an optical structure of the present invention, a colored layer is formed on a substrate made of a light-transmitting organic polymer, and the colored layer is irradiated with laser light intermittently or continuously. Is selectively removed.
The center wavelength of the laser beam is preferably 250 nm or more and 600 nm or less.
The colored layer may be formed by a transfer method.

  A display device according to the present invention includes the optical structure according to the present invention.

According to the optical structure of the present invention, a colored layer is formed on a substrate made of a light-transmitting organic polymer, and the colored layer is selectively removed by laser light. A high-level optical function such as a black matrix and a microlens can be imparted to the substrate made of
Therefore, an organic polymer optical structure having a high degree of optical function such as a black matrix and a microlens can be provided.

  According to the method for producing an optical structure of the present invention, a colored layer is formed on a substrate made of a light-transmitting organic polymer, and the colored layer is irradiated with laser light intermittently or continuously. Since the colored layer is selectively removed, it is possible to easily and inexpensively manufacture an organic polymer optical structure having a high optical function such as a black matrix and a microlens.

  According to the display device of the present invention, since the optical structure of the present invention is provided, high-level optical functions such as a black matrix and a microlens can be expressed, and it is inexpensive and excellent in mass productivity.

The best mode for carrying out the optical structure of the present invention, the method for manufacturing the same, and the display device including the optical structure will be described.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

“First Embodiment”
FIG. 1 is a perspective view showing a plastic film substrate (optical structure) for a liquid crystal display (LCD: display device) according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA of FIG. It is.
The plastic film substrate 1 has a colored layer 3 formed on the surface (one principal surface) 2a of a plastic (organic polymer) film (base material) 2 having transparency to visible light. A plurality of circular openings 4 formed by selective removal with laser light are formed in a matrix. By these openings 4, a plurality of locations on the surface 2 a of the plastic film 2 are exposed surfaces 5.

The plastic film 2 is not particularly limited as long as it has sufficient strength and can be an organic polymer film transparent to visible light. For example, polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), triallyl cyanurate (TAC), cellulose acetate, polystyrene (PS), polyether, polyimide, epoxy, phenoxy, polyvinylidene fluoride, acrylic, polyethylene (PE), nylon, polyvinyl alcohol ( PVA), polytetrafluoroethylene (PTFE), polyfluoroacetylene (PFA) and the like can be appropriately selected.
Further, the thickness of the plastic film 2 is not particularly limited, and a film having a thickness of about 50 to 250 μm can be used.

Depending on the application, a plastic sheet may be used instead of the plastic film 2. In this case, the material of the transparent sheet may be any material as long as it has sufficient strength and can be a transparent polymer sheet, and a sheet made of the above-described material is preferable.
The thickness of the plastic sheet is not particularly limited, and those having a thickness of about 30 μm to 10 mm can be used.
Further, instead of the plastic film 2, a plastic plate made of the above-described material may be used. The thickness of the plastic plate is not particularly limited, and those of 0.5 mm to 30 mm can be usually used.

The colored layer 3 is a film containing a pigment, metal fine particles and the like having sufficient shielding properties against light in a desired wavelength band in a thin plastic (organic polymer) layer, For example, it is 0.1 μm to 10 μm.
As the plastic, any material may be used as long as it has good wettability with the above-described substances and has good adhesion to the plastic film 2, such as acrylic, polyester, polyurethane, polyolefin, polystyrene, cellulose, polyvinyl pyrrolidone, polyvinyl alcohol, Resins such as polyethylene glycol, polypropylene glycol, butyral and alkyd, or celluloses such as ethyl cellulose can be used alone or in combination.
These plastics may be appropriately selected from any one of a room temperature curable resin, an ultraviolet curable resin, and an electron beam curable resin depending on the application.

Any dye may be used as long as it can ensure sufficient shielding against light in a desired wavelength band. For example, organic dyes such as carbon black, aniline black, titanium black, and phthalocyanine are preferably used. . Among these organic dyes, black dyes such as carbon black are particularly preferable because they almost block light in the visible light range.
As the metal fine particles, fine particles such as gold fine particles, silver fine particles, ruthenium fine particles, palladium fine particles, copper fine particles and tin fine particles, or alloy fine particles containing one or more of these metals are preferably used.

The opening 4 has a diameter of, for example, 10 μm to 100 μm, and the optical function of the colored layer 3 can be further enhanced by forming the colored layer 3 with a certain rule.
As the arrangement of the openings 4, besides a matrix shape, a honeycomb lattice shape, a kagome lattice shape, a triangular lattice shape, a Penrose lattice shape, or the like is selected as appropriate.

  In this plastic film substrate 1, since, for example, a plurality of circular openings 4 are formed in a matrix in the colored layer 3 having sufficient shielding properties against visible light, these openings 4 are made of visible light. It becomes a transmission area. Therefore, the colored layer 3 in which the openings 4 are formed in a matrix has a function as a black matrix for LCD.

Next, a method for manufacturing the plastic film substrate 1 will be described.
First, a plastic material in which the colored layer 3 is formed on the surface 2a of the plastic film 2 is prepared.
This plastic material can be produced by applying a colored layer-forming paint to the surface 2 a of the plastic film 2.
This colored layer-forming coating material can be adjusted by dissolving and mixing the above-described pigment in an organic solvent.

  Next, the plastic material is intermittently irradiated with a laser beam having a center wavelength of 250 nm or more and 600 nm or less, more preferably 250 nm or more and 450 nm or less, thereby forming a plurality of openings 4 in the colored layer 3 in a matrix. . In this case, since only the colored layer 3 is selectively removed, the plastic film 2 therebelow is not damaged by the laser beam or the like and remains almost in its original shape.

Here, when the center wavelength of the laser beam is less than 250 nm, the processing efficiency is poor, and in some cases, the colored layer 3 cannot be completely removed selectively, and a part of the colored layer remains in the opening 4. On the other hand, when the center wavelength exceeds 600 nm, the plastic film 2 in the opening 4 is damaged, the periphery of the opening 4 is damaged, or the inside of the opening 4 is irregularly shaped. This is because problems such as formation of a raised portion are likely to occur, and it becomes difficult to form the opening 4 having a desired shape.
The intensity of this laser beam is preferably a Gaussian distribution.

  As the type of laser light, pulsed laser light is preferable. The reason why this pulsed laser beam is preferable is that the irradiation energy can be easily controlled. The frequency of the pulse laser beam is preferably 10 KHz or more and 300 KHz or less, more preferably 50 KHz or more and 100 KHz or less. Here, the reason for limiting the frequency as described above is that when the frequency is less than 10 KHz, it is difficult to control the irradiation energy. On the other hand, when the frequency exceeds 100 KHz, the laser beam irradiation apparatus is enlarged. It is also complicated and the cost of the apparatus becomes high.

The irradiation energy of this pulse laser beam is preferably 5 μJ or more and 100 μJ or less per pulse. This is because if the irradiation energy per pulse is less than 5 μJ, the processing speed is reduced and the working efficiency is lowered. On the other hand, if the irradiation energy per pulse exceeds 100 μJ, the shape of the opening 4 is controlled. Because it becomes impossible.
As described above, the plurality of openings 4 can be easily and inexpensively formed in the colored layer 3 formed on the surface of the plastic film 2.

The LCD plastic film substrate 1 thus obtained can be used as a black matrix by sticking it to the surface of the glass substrate on the front side of the LCD with an adhesive or the like.
The plastic film substrate 1 can be applied to a display device such as a projector screen or a rear projector screen. Even in this case, a function peculiar to each device can be expressed. Moreover, it can be mass-produced at a low cost with a simpler manufacturing process.

In the plastic film substrate 1, an intermediate layer that transmits visible light may be formed between the plastic film 2 and the colored layer 3.
By setting the difference between the refractive index of the intermediate layer and the refractive index of the plastic film 2 to 0.2 or more, more preferable optical characteristics can be obtained. The reason is that the optical function is enhanced by increasing the refractive index difference at the interface between the intermediate layer and the plastic film 2.

As described above, according to the plastic film substrate for LCD 1 of the present embodiment, a plurality of openings 4 formed by selectively removing the colored layer 3 formed on the surface 2a of the plastic film 2 with a laser beam are provided in a matrix. Therefore, it is possible to impart a high degree of optical function such as a black matrix and a microlens to the plastic film substrate.
Therefore, it is possible to easily and inexpensively provide an LCD plastic film substrate having high optical functions such as a black matrix and a microlens.

  According to the manufacturing method of the plastic film substrate for LCD of the present embodiment, the colored layer 3 formed on the surface 2a of the plastic film 2 is intermittently irradiated with laser light having a center wavelength of 250 nm or more and 600 nm or less. Since the plurality of openings 4 are formed in a matrix in the layer 3, an LCD plastic film substrate having a high optical function called a black matrix can be manufactured easily and inexpensively.

“Second Embodiment”
FIG. 3 is a cross-sectional view showing a plastic film substrate (optical structure) according to the second embodiment of the present invention. The plastic film substrate 11 according to this embodiment is different from the plastic film substrate 1 according to the first embodiment. In the plastic film substrate 1 of the first embodiment, the plastic film substrate 1 of the first embodiment has only a plurality of circular openings 4 formed in a matrix in the colored layer 3, whereas the plastic film substrate 11 of the present embodiment has a plurality of circular openings 4. The plurality of openings 4 formed in a matrix form exposes a plurality of locations on the surface 2a of the plastic film 2, and these exposed surfaces are formed as spherical exposed surfaces (curved surfaces) 12 that expand upward. The modified region 14 in which a plurality of flat cavities 13 are irregularly formed is formed in the region of the exposed surface 12 and in the plastic film 2. That.

The modified region 14 is a region where the plastic film 2 has been altered by the irradiation of the laser beam, and has a spherical shape with a diameter of, for example, 1 μm to 50 μm. The shape of the modified region 14 is preferably a size and a shape suitable for the target optical function, and in addition to a spherical shape, a rotating body having an elliptical cross section having a major axis and a minor axis different from each other, a spindle, a convex lens, It can be appropriately selected from polyhedrons and the like.
In particular, when the plastic film substrate 11 is used for a reflector or the like, the modified region 14 is preferably spherical.

  These cavities 13 are arranged irregularly in the thickness direction of the plastic film 2, irregularly arranged in the direction along the surface 2 a of the plastic film 2, and the major axis direction thereof is the surface 2 a of the plastic film 2. Are scattered so as to substantially coincide with the direction along. Although FIG. 3 shows a case where the major axis direction of these cavities 13 substantially coincides with the direction along the surface 2a of the plastic film 2, the major axis direction of these cavities 13 may be oriented in various directions. Of course it exists. For example, the direction in which the major axis direction is inclined with respect to the surface 2a of the plastic film 2 may be mixed with the one that substantially coincides with the direction along the surface 2a, and the major axis direction is mixed with the surface 2a of the plastic film 2. On the other hand, various slopes may be mixed.

The plastic film substrate 11 can be manufactured in the same process as the plastic film substrate 1 of the first embodiment by changing the laser light irradiation conditions.
In this case, a part of the surface of the plastic film 2 is exposed in the opening 4, and a part of the surface becomes a spherical exposed surface 12. Further, in the region of the exposed surface 12 and in the plastic film 2. It is necessary to control the irradiation condition of the pulse laser beam so that a modified region 14 in which a plurality of flat cavities 13 are irregularly formed is formed.

  For example, if the center wavelength of the pulse laser beam is 250 nm or more and 400 nm or less, the frequency is 20 KHz or more and 60 KHz or less, and the irradiation energy is 5 μJ or more and 100 μJ or less per pulse, the region within the spherical exposed surface 12 and the plastic film 2, the denatured region 14 in which a plurality of flat cavities 13 are irregularly formed can be formed with high accuracy.

In the plastic film substrate 11, an upper layer having transparency with respect to light in the visible light region may be formed on the plastic film 2 and the colored layer 3.
Further, in order to give the plastic film substrate 11 the characteristics as an antireflection film or a reflection film, the plastic film 2 itself has an interference property, or is visible between the plastic film 2 and the colored layer 3. An intermediate layer that transmits light may be formed, and the intermediate layer may be provided with interference.

In particular, when used for applications such as a screen, it is preferable to form a layer having a function as a colored film, a reflective film, or a half mirror film around the opening 4.
Further, it is preferable to form a single-layer or multilayer interference film and a hard coat layer in the opening 4. With such a configuration, the optical characteristics can be further improved by reducing the reflected light on the surface. Further, by forming a hard coat layer, surface fastness can be enhanced.

This plastic film substrate 11 can also exhibit the same operations and effects as the plastic film substrate 1 of the first embodiment.
Moreover, since the modified region 14 in which a plurality of flat cavities 13 are irregularly formed is formed in the region of the spherical exposed surface 12 and in the plastic film 2, the exposed surface is spherical. The light transmitted or reflected through the exposed surface is dispersed in various directions, and an excellent effect of enhancing the scattering characteristic can be obtained.

“Third Embodiment”
FIG. 4 is a cross-sectional view showing a plastic film substrate (optical structure) according to the third embodiment of the present invention. The plastic film substrate 21 according to this embodiment is different from the plastic film substrate 11 according to the second embodiment. In the plastic film substrate 11 of the second embodiment, the plurality of openings 4 formed in a matrix form exposes a plurality of locations on the surface 2a of the plastic film 2, and these exposed surfaces face upward. Although a spherical exposed surface (curved surface) 12 is expanded, a modified region 14 in which a plurality of flat cavities 13 are irregularly formed is formed in the region of the exposed surface 12 and in the plastic film 2. On the other hand, in the plastic film substrate 21 of the present embodiment, the plastic film substrate 21 is transparent between the plastic film 2 and the colored layer 3 and has transparency to visible light. A spherical exposed surface in which a plurality of openings 4 formed in the form of a matrix 22 and a plurality of openings 4 formed in a matrix form exposes a plurality of portions of the surface 22a of the intermediate layer 22 and expands the exposed surfaces upward. 23, and a modified region 25 in which a plurality of flat cavities 24 are irregularly formed is formed in the region of the exposed surface 23 and in the intermediate layer 22.

By using the intermediate layer 22 as a base layer made of a high refractive index resin having a refractive index of 1.6 or more and 1.8 or less, for example, more preferable optical characteristics such as high light transmittance can be obtained.
As this high refractive index resin, organic high refractive index resin such as fluorene epoxy compound, fluorene acrylate compound, fluorene polyester, inorganic high refractive index material such as polymethyldiphenylsilane, polyphenylsilane, polyphenylsilane, or An organic-inorganic composite material in which metal oxides such as zirconium oxide, titanium oxide and tin oxide, and metal fine particles such as gold, silver, iron and ruthenium are dispersed is preferably used.

Furthermore, more preferable optical characteristics can be obtained by imparting conductivity to the underlayer.
Examples of the material that imparts conductivity to the underlayer include metal oxide fine particles such as antimony-containing tin oxide (ATO) fine particles and antimony oxide fine particles, ionic conductors such as quaternary ammonium salts, and conductive polymers. be able to.

  Such a plastic film substrate can be used for applications such as a film substrate on which a black matrix is formed, a projector screen, a rear projection television screen, and a microlens array.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by this Example.
"Example"
A carbon black particle dispersion film having a thickness of 2 μm was formed as a colored layer on the surface of a transparent plate made of a polymethyl methacrylate resin having a thickness of 2 mm to obtain a plastic substrate.
Next, using a high-power pulsed UV laser (AVIA ^™ 355, Coherent Japan), this plastic substrate was irradiated with pulsed laser light having a central wavelength of 355 nm, a frequency of 60 KHz, and an output of 1.8 W. An optical structure as shown was produced. The number of irradiations was 250 pulses per opening.

FIG. 5 is a laser microscope image showing the surface shape of the optical structure produced in this manner.
According to FIG. 5, the carbon black particle-dispersed film is formed in a straight line so that a plurality of circular openings selectively removed by laser light and adjacent openings are in contact with each other. I found out. It was also found that a part of the surface of the transparent plate was exposed by these openings, and this exposed surface was slightly concave with R.

  In the optical structure of the present invention, a colored layer is formed on a base material made of a light-transmitting organic polymer, and this colored layer is selectively removed by laser light. In particular, film substrates having a black matrix such as a liquid crystal display (LCD), a plasma display panel (PDP), an organic electroluminescence display (organic EL), a projector screen, a rear projection television screen, a microlens array, etc. When used in the above, it is possible to exhibit a high degree of optical function, and it is inexpensive and excellent in mass productivity, and its industrial utility value is very large.

It is a perspective view which shows the plastic film board | substrate for LCD of the 1st Embodiment of this invention. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which shows the plastic film board | substrate of the 2nd Embodiment of this invention. It is sectional drawing which shows the plastic film board | substrate of the 3rd Embodiment of this invention. It is a laser microscope image which shows the surface shape of the optical structure of the Example of this invention.

Explanation of symbols

1, 11, 21 Plastic film substrate 2 Plastic film 2a Surface 3 Colored layer 4 Opening 5, 12, 23 Exposed surface 13, 24 Cavity 14, 25 Denatured region 22 Intermediate layer 22a Surface

Claims (14)

A colored layer is formed on a base material made of an organic polymer having translucency,
An optical structure obtained by selectively removing the colored layer with a laser beam.   A modified region in which a part of one main surface of the substrate is exposed as a result of selective removal of the colored layer, and a plurality of flat cavities are irregularly formed in the region of the exposed surface and in the substrate. The optical structure according to claim 1, wherein the optical structure is formed.   3. The modified region is formed in a region of one or more of the exposed surfaces and in the base material, wherein a plurality of locations on the one main surface are exposed surfaces. Optical structure. Forming a light-transmitting intermediate layer between the substrate and the colored layer;
A modified region in which a part of one principal surface of the intermediate layer is exposed by selective removal of the colored layer, and a plurality of flat cavities are irregularly formed in the region of the exposed surface and in the intermediate layer The optical structure according to claim 1, wherein the optical structure is formed.   5. The modified region is formed by forming a plurality of portions of the main surface as exposed surfaces, and forming the modified region in a region of one or more exposed surfaces of the exposed surfaces and in the intermediate layer. Optical structure.   6. The optical structure according to claim 3, wherein each of the exposed surfaces is connected to at least one adjacent exposed surface.   The optical structure according to claim 2, wherein the exposed surface is a curved surface.   The optical structure according to any one of claims 2 to 7, wherein a shape of the denatured region is any one of a spherical shape, a polyhedron, and a spindle shape.   4. The optical structure according to claim 1, wherein an optically transparent intermediate layer is formed between the base material and the colored layer.   The optical structure according to claim 1, wherein an upper layer having translucency is provided on one or both of the colored layer and the exposed surface.   An optical structure characterized in that a colored layer is formed on a substrate made of an organic polymer having translucency, and the colored layer is selectively removed by irradiating the colored layer intermittently or continuously with a laser beam. Body manufacturing method.   12. The method of manufacturing an optical structure according to claim 11, wherein a center wavelength of the laser beam is 250 nm or more and 600 nm or less.   13. The method for manufacturing an optical structure according to claim 11, wherein the colored layer is formed by a transfer method.   A display device comprising the optical structure according to claim 1.

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