JP2001174608A - Method for producing optical collimator sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an optical collimator sheet by which a high performance optical collimator sheet which efficiently converges diffused light, has high directivity and gives high luminance collimated light can easily be produced with good productivity. SOLUTION: A coating fluid containing a binder, two or more solvents different from each other in the boiling point and a dispersed light scattering material is applied on a transparent substrate and many light transmissive spheres are scattered on the coating fluid while the coating fluid is in a semi-hardened state. The light transmissive spheres not bonded to the coating fluid are removed, the bonded light transmissive spheres are pressed and brought into contact with the substrate and then the coating fluid is hardened to produce the objective optical collimator sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of an optical collimator sheet for making diffused light parallel, and
The present invention relates to a method for manufacturing an optical collimator sheet capable of producing a high-performance optical collimator sheet capable of obtaining collimated light having high directivity and high brightness.

[0002]

2. Description of the Related Art In recent years, the frequency of use of liquid crystal displays (LCDs) as word processor and computer displays has been greatly increased. In addition, the use of the LCD as a monitor of a medical diagnostic apparatus such as an ultrasonic diagnostic apparatus, a CT diagnostic apparatus, and an MRI diagnostic apparatus, which has conventionally been mainly a CRT (Cathode Ray Tube), is being considered.

[0003] LCDs have numerous advantages, such as being easy to miniaturize, thin and lightweight. On the other hand, the viewing angle characteristics are poor (the viewing angle is narrow). That is, the contrast ratio of the image sharply decreases depending on the viewing direction and the angle, and the inversion of the gradation also occurs, so that the image looks different. Therefore, there is a problem that the image cannot be properly observed depending on the position of the observer or the like. In particular,
In medical applications such as those described above, diagnosis is performed based on the density of the image, so an image with a high contrast ratio is required.
Inappropriate recognition of an image causes erroneous diagnosis and discrepancy in diagnosis results. Therefore, especially over a wide viewing angle,
A display image with a high contrast ratio is required. further,
In a medical monitor, a display image is usually a monochrome image, and the image contrast greatly depends on the viewing angle, which is more problematic.

As a wide viewing angle LCD, IPS (In-Plan)
e Swiching) mode, MVA (Multidomaoin Vertical A)
lignement mode LCDs are also known. However, even with these, a sufficiently wide viewing angle has not been ensured for monochrome images, particularly for medical use.

On the other hand, as an LCD capable of obtaining an image having a good contrast ratio over a wide viewing angle, collimated light (parallel light) is used as light (backlight) illuminating the liquid crystal panel from the back (collimated backlight). Further, there is known an LCD in which light carrying an image passing through a liquid crystal panel is diffused by a diffusion plate. Also,
A PL-LCD that combines ultraviolet light and a fluorescent screen is also being studied. In these LCDs, higher contrast can be realized by using a backlight having higher directivity and higher luminance. Therefore, in medical applications requiring high contrast and a wide viewing angle as described above, it is particularly preferable to use a backlight having strong directivity and high luminance. for that reason,
There has been a demand for an optical collimator having strong directivity and capable of obtaining high-brightness collimated light.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-performance optical collimator sheet capable of efficiently condensing diffused light, having strong directivity and obtaining high-luminance collimated light. It is another object of the present invention to provide a method for manufacturing an optical collimator sheet which can be manufactured at a time. By using the optical collimator sheet manufactured by the manufacturing method of the present invention, a fluorescent lamp is used in a rear projection display such as a liquid crystal display of a type in which the distance from the image forming surface to the screen (observation surface) is relatively short. Diffuse light source, such as
When used together with an image display element such as a liquid crystal panel and a light diffusion screen (or a fluorescent screen), a high-quality image with a wide viewing angle can be displayed.

[0007]

In order to achieve the above object, the present invention provides a coating solution containing two or more solvents having different boiling points and a binder, and a light scattering material dispersed therein. Applying to the body, this coating solution is dispersed in a semi-cured state, and a large number of light-transmitting spheres are sprinkled. Thereafter, the light-transmitting spheres not adhered to the coating solution are removed, and the light-transmitting spheres are further pressed. And then curing the coating liquid after contacting the support with the support.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing an optical collimator sheet according to the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

FIG. 1 conceptually shows an example of a display device using an optical collimator sheet manufactured by the manufacturing method of the present invention. A display device 10 shown in FIG. 1 is a so-called liquid crystal display (hereinafter, referred to as an LCD) using a liquid crystal panel 12 as an image display means.
2, a backlight unit 14 that uses a light collimator sheet 20 manufactured by the manufacturing method of the present invention, in which a backlight is incident on the liquid crystal panel 12, and light that diffuses light carrying an image that has passed through the liquid crystal panel 12. And a diffusion plate 16.

The display device 10 includes a backlight unit 1
4 is a known LCD except that the optical collimator sheet according to the present invention is used. That is, the backlight unit 1
The collimated light (collimated backlight) emitted from 4 enters the liquid crystal panel 12 driven according to the display image and passes therethrough to become light carrying an image, which is diffused by the light diffusion plate 16. The image is displayed.

FIG. 2 shows a conceptual diagram of the optical collimator sheet 20. The light collimator sheet 20 according to the present invention includes a transparent support sheet 22 and a plurality of light-transmitting spheres 24 (hereinafter, beads 2) that are partially in contact with and fixed to the support sheet 22.
4) and a reflective layer 26 that diffuses light incident on portions other than the contact portion between the support sheet 22 and the beads 24 (or further in the vicinity of the contact portion) and fixes the beads 24 to the support sheet 22. It is configured to have.

As shown in FIG. 2, the optical collimator sheet 20 is arranged and held in the backlight section 14 with the beads 24 facing the liquid crystal panel 12. Housing 18
The diffused light emitted from the light source inside enters from the support sheet 22 side, and enters the beads 24 from the contact portion between the beads 24 and the support sheet 22 by the action of the reflection layer 26,
The light is refracted by the spherical beads 24 and is appropriately condensed to be collimated light (parallel light). On the other hand, the diffused light other than the contact portion, that is, the diffused light incident on the reflective layer 26 is preferably diffused on the surface or inside of the reflective layer 26, that is,
Reflected by the optical collimator sheet 2, returned to the housing 18, reflected by the inner surface of the housing 18, and again
Incident at 0.

That is, the optical collimator sheet 20
Of the diffused light emitted from the light source, only the light appropriately incident on the beads 24 is collected and emitted as collimated light. On the other hand, the light incident on the reflection layer 26 is well reflected, so that the light emitted from the light source can be used without waste. Therefore, the optical collimator sheet 20
Can emit collimated light with high directivity and high luminance with little light passing through the reflective layer 26 (hereinafter referred to as leakage light), high light use efficiency, and high efficiency. Therefore, by using the optical collimator sheet 20, it is possible to realize a display device 10 which realizes a high contrast ratio over a wide viewing angle and is suitable for a monitor of a medical diagnostic apparatus.

The support sheet 22 is not particularly limited, and various materials can be used as long as they have a sufficient light transmittance and a sufficient mechanical strength according to the application. Specifically, various types of glass, polyester, polyolefin, polyamide, polyether, polystyrene,
Various resin materials such as polyesteramide, polycarbonate, polyphenylene sulfide, polyetherester, polyvinyl chloride, and polymethacrylic acid ester are preferably exemplified. The optical collimator sheet 20 is
It may be a rigid plate or a flexible sheet or film. The material and thickness of the support sheet 22 may be selected depending on the required mechanical strength and application.

The beads 24 are light-transmitting (substantially) spheres,
In the illustrated example, a part thereof is in contact with the support sheet 22 and is fixed to the support sheet 22 by the reflection layer 26 (the binder thereof). The material of the beads 24 is not particularly limited, and various materials can be used as long as they are transparent. For example, various examples of the material of the above-described sheet material 18 are provided.
Glass and (meth) acrylic resin are preferably used in terms of good optical characteristics.

The diameter of the beads 24 is not particularly limited.
An appropriate selection may be made according to the use and size (area) of the optical collimator sheet 20. If the size of the beads 24 is too small, the reflection layer 26 to be described later must be thinned, so that leakage light and the like increase, and as a result, the directivity and efficiency of the optical collimator sheet 20 (that is, the luminance of the emitted light) decrease. Would.
Therefore, the diameter of the beads 24 is preferably set to 40 μm or more. Conversely, if the size of the bead 24 is too large, the shape of the bead 24 causes noise to the image. Therefore, empirically, the diameter of the bead 24 is preferably set to 5 mm or less. Therefore, the diameter of the beads 24 is 40 μm.
m to 5 mm, particularly preferably 100 μm to 2 mm.

Although the degree of dispersion of the beads 24 is not particularly limited, it is preferable that the diameter of the beads 24 is as uniform as possible (monodispersion). For example, if the average diameter of the beads 24 is 800 μm, as in the example described later, 600 μm to 100 μm
It is preferably within 0 μm. That is, beads 24
Is preferably within ± 25% of the average particle size.

The reflection layer 26 is formed of the beads 24 as described above.
In addition to blocking the passage of light in areas other than the contact portion between the sheet and the support sheet 22, the beads 24 are fixed (adhered) to the support sheet 22. Basically, the entire surface of the support sheet 22 at least in a region where the beads 24 are fixed. Formed so as to cover The reflective layer 26 is used to wrap the beads 24 on the support sheet 22.
The light scattering substance is dispersed in a binder (adhesive) fixed to the substrate.

In the optical collimator sheet 20, if the reflection layer 26 is thin, a large amount of leakage light is generated, the directivity and luminance of the collimated light are reduced, and the beads 2
4, the adhesive strength is weak, and sufficient mechanical strength cannot be obtained.
Conversely, if the beads 24 are buried in the reflective layer 26 more than half, the light incident on the beads 24 is reflected by the reflective layer 26, and the efficiency is reduced, and the directivity and the brightness are also reduced. In consideration of the above, the thickness (the thickness of the maximum portion) of the reflective layer 26 is preferably 20 μm to the radius of the beads 24, particularly preferably 50 μm to the radius of the beads 24.

The binder used for the reflection layer 26 is not particularly limited, and various binders can be used as long as the beads 24 can be fixed to the support sheet 22. Therefore,
A solid binder may be dissolved in a solvent, applied, and then the solvent may be evaporated and then cured.The binder may be a radiation-curable binder such as an ultraviolet-curable binder or an electron beam-curable binder. May be used, a moisture-curable binder may be used, or a self-curing binder such as a two-component type may be used. Preferably, a binder in which a solid binder is dissolved in a solvent and applied, and then the solvent is evaporated and cured, or a radiation-curable binder is used.

Examples of the material include urethane resin, vinyl acetate resin, ethylene-vinyl acetate copolymer, vinyl chloride resin, vinyl chloride-vinylidene chloride copolymer, (meth) acrylate resin, butyral resin, silicone resin, and polyester. , Vinylidene fluoride resin, nitrocellulose resin, polystyrene, styrene-acrylic copolymer, polyethylene, polypropylene, polyethylene chloride, rosin derivative, and mixtures thereof. In particular, urethane resins, acrylic resins and silicone resins are preferably used. In the present invention, it goes without saying that the binder may have various components contained in a normal binder such as a plasticizer, in addition to the adhesive component.

On the other hand, the light scattering substance used for the reflection layer 26 is not particularly limited, and various substances can be used as long as they do not absorb the light emitted from the light source. Preferably, fine particles of a substance having a refractive index of 1.6 or more are preferred. Thus, efficient light diffusion (reflection) with little attenuation can be performed. Specifically, yttrium oxide (Y ₂ O
₃ ), zirconium oxide (ZrO ₂ ), gadolinium oxide (Gd
₂ O ₃ ), lanthanum oxide (La ₂ O ₃ ), hafnium oxide (Hf
One or more of fine particles such as O ₂ ), barium sulfate (BaSO ₄ ), alumina (Al ₂ O ₃ ), and titanium oxide (TiO ₂ ) are preferably exemplified. In particular, yttrium oxide, zirconium oxide, gadolinium oxide, lanthanum oxide, hafnium oxide, titanium oxide, and the like are preferable.

In the coating film of these fine particles, a gap is formed between the contacting fine particles, and the binder does not flow into this gap, and there are many regions where air exists. Therefore, a large difference in the refractive index between the air (refractive index 1) and the light scattering substance can be ensured, whereby the attenuation of light in the reflective layer 26 is significantly reduced, and
Can be returned to the inside of the housing 18 or the like with high efficiency.

Although the particle size of the light scattering substance is not particularly limited, fine particles having a D50% particle diameter of 0.1 μm to 2 μm in a laser diffraction method, for example, are preferable in that good optical characteristics can be obtained. is there.

Hereinafter, such an optical collimator sheet 20 will be described.
The manufacturing method of the present invention for fabricating is described with reference to FIG.

First, a predetermined amount of a binder is dissolved in an appropriate solvent, a predetermined amount of a light-scattering substance is added to this solution, and the mixture is stirred, and a coating liquid (hereinafter referred to as a paint) in which the light-scattering substance is dispersed. Is prepared. In addition, this paint (that is, reflection layer 2)
In 6), the amount ratio of the binder to the light-scattering substance is not particularly limited. However, considering the adhesive force of the beads 24 and the optical characteristics of the reflection layer 26, the weight ratio of “light-scattering substance: binder” is 0.1%. Preferably, the ratio is 5: 1 to 20: 1. In addition,
At this ratio, the binder also contains components such as a plasticizer.

In the present invention, a paint is prepared using two (or three or more) solvents having different boiling points.

As will be described in detail later, in the production method of the present invention,
After the paint is applied to the instruction sheet 22, a large amount of the beads 24 are scattered and adhered while the paint is in a semi-cured state, and then the extra beads 24 (beads 24 not adhered to the paint) are removed. Therefore, in order to ensure suitable workability and productivity, the coating material can easily and suitably disperse the light scattering material during preparation, and has a viscosity and thixotropic properties suitable for application at the time of application, It becomes a semi-cured state in a short time after application, and in this semi-cured state, scattering and adhesion of beads,
It is preferable to have appropriate hardness and adhesive strength (adhesive strength) for pressing.

Therefore, as in the present invention, by using two or more solvents having different boiling points (hereinafter referred to as a low-boiling solvent and a high-boiling solvent) as a solvent for preparing the coating material, the coating material is coated with a low-boiling solvent. Quickly evaporates, and in a short time, the low-boiling solvent in the paint almost evaporates and a large amount of the high-boiling solvent remains, that is, a semi-cured state. In addition, the dispersibility of the light-scattering substance and the viscosity at the time of application can be adjusted with the entire amount of the solvent, and the hardness and adhesive strength at the time of semi-curing can be adjusted mainly with the amount of the high-boiling solvent, so that good workability can be ensured. Therefore, according to this method, an optical collimator sheet having the above-described excellent characteristics can be easily manufactured with high productivity.

The low-boiling solvent and the high-boiling solvent are not particularly limited, and a solvent which can dissolve the binder to be used and has a different boiling point may be appropriately selected. In consideration of productivity, workability, and the like, the low-boiling solvent has a boiling point of 50 ° C or higher.
A solvent having a boiling point of 115 ° C. to 200 ° C. is preferably used as the high boiling point solvent. Specifically, examples of the low boiling point solvent include acetone, chloroform, tetrahydrofuran, hexane, ethyl acetate, ethanol, methyl ethyl ketone, cyclohexane, acetonitrile, 2-propanol and the like. Examples of the high boiling point solvent include methyl isobutyl ketone, ethylenediamine, 1-butanol, butyl acetate, xylene, N, N-dimethylformamide, cyclohexanone, diacetone alcohol, N, N-dimethylacetamide, N-methylformamide and the like. .

The amount ratio of the low-boiling solvent to the high-boiling solvent in the coating material is not particularly limited, and may be appropriately determined according to the solvent and the binder used. In consideration of the time required to reach an appropriate semi-cured state, the viscosity and hardness at the time of application or semi-cured state, workability, and the like, the low-boiling solvent and the high-boiling solvent have a volume ratio of 2: 8 to Preferably, the ratio is 8: 2. The ratio of the binder to the solvent (all two or more solvents) is not particularly limited, and may be appropriately determined according to the workability, the viscosity at the time of application or in a semi-cured state, and the like.

The coating thus prepared is subjected to viscosity adjustment, filtration, defoaming, etc., if necessary.
This paint is applied to the support sheet 22 as shown in FIG. At this time, the amount of the paint applied (the thickness of the paint layer 28) is appropriately determined according to the intended thickness of the reflective layer 26. The method of applying the paint is not particularly limited,
All known coating methods such as a doctor blade, a roll coater, and a knife coater can be used.

The paint is dried to a semi-cured state in which the low boiling point solvent has almost evaporated. Drying may be natural drying, heating drying, or drying under reduced pressure. In the semi-cured state, the paint layer 28 preferably has such a hardness that the paint does not touch the finger even when touched with a finger, and that the beads 24 do not settle under their own weight, and that the adhesive strength is sufficient to sufficiently adhere the beads 24. .

In this semi-cured state, a predetermined area of the paint layer 28 (a light passing area of the optical collimator sheet 20 to be produced)
A sufficient amount of beads 24 is sprayed so as to cover the entire surface of this region. Next, the beads 24 are evenly distributed. Preferably, the beads 24 are uniformly leveled while being pressed. As a result, as shown in FIG.
The entire surface of the predetermined region of the layer and the paint layer 28 is covered with a high density (optimally, a close-packed state), and is in a suitably bonded state. The pressing force at this time is not particularly limited, and may be appropriately determined according to the hardness, the adhesive strength, and the like of the paint layer 28.
/ Cm ^{2 to} 100 g / cm ² . The pressing may be performed by hand, or may be performed using a jig such as a roller or a plate material.

Next, as shown in FIG. 3C, excess beads 24 not adhered to the paint layer 28 are removed. In addition, in the present invention, as described above, since one layer of the beads 24 is in a state of covering and bonding the predetermined region of the paint layer 28 over the entire surface, the extra beads 24 are
The support sheet 22 can be easily removed by slanting the support sheet 22, turning over the support sheet 22, lightly wiping with a brush or the like, tapping lightly, or combining these operations.

Next, the beads 24 adhered to the paint layer 28 are pressed by using an elastic member (jig) such as a rubber roller or an elastic plate material, and as shown in FIG.
Part of each bead 24 (optimally part of all beads 24)
Are in contact with the support sheet 22. Thereafter, the paint layer 28 is completely dried (cured), and the support sheet 22,
An optical collimator sheet 20 having beads 24 fixed in a state of being partially in contact with the support sheet 22 and a reflection layer 26 for diffusing light incident to portions other than the contact portion and fixing the beads 24 is completed.

As described above, in the present invention, not only a binder which is melted and applied in a solvent and is cured by evaporating the solvent, but also various curable binders such as a radiation curable binder can be used. It is. At this time, similarly, a paint is prepared, applied to the support sheet 22 and dried to evaporate most of the low-boiling solvent, and the binder is not cured (if necessary, it may be slightly cured. Good)
After the semi-cured state is reached, the beads are sprayed, pressurized, the unadhered beads 24 are removed, and the beads 24 are pressed to contact the support sheet 22. Next, after evaporating the remaining solvent, the coating material is cured using a curing method according to the binder, and the optical collimator sheet 20 is completed.
For example, if an ultraviolet-curable binder is used, the coating is cured by irradiating ultraviolet rays using an ultraviolet lamp or the like to complete the optical collimator sheet 20.

In the manufacturing method of the present invention, in consideration of the contamination of the beads 24 by the paint, the coating thickness of the paint, and the ease of controlling the preparation of the paint, etc., the layer thickness of the paint layer 28 after the beads 24 are pressed, It is advantageous that the change in the thickness of the reflective layer 26 obtained by drying (curing) is small. Most ideally, when the beads 24 are pressed and brought into contact with the support sheet 22, the beads 24 are half-buried in the paint layer 28 (reflection layer 26), and the paint layer 28 is cured without shrinking as it is. It is. In this regard, when the beads 24 are pressed and brought into contact with the support sheet 22, it is advantageous that the high-boiling solvent contained in the paint layer 28 is small.

In the case of a curable binder such as a radiation curable binder, curing of the binder and evaporation of the solvent are basically unrelated, and the binder does not cure even when the solvent evaporates. Therefore, even if the amount of the high-boiling solvent after the low-boiling solvent evaporates is small, the support sheet 22 due to the pressing of the beads 24 can be used.
And the like can be easily performed. Therefore, when using a radiation-curable binder or the like, increase the ratio of the low-boiling solvent in the paint to ensure workability during preparation and application of the paint, and then evaporate the low-boiling solvent after application. It is preferable that the beads 24 be bonded in a semi-cured state by utilizing the hardness and adhesive strength of the uncured binder itself. Thereby, the volume change of the paint layer 28 after the beads 24 are pressed can be reduced.

Although the method of manufacturing the optical collimator sheet of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various modifications and changes can be made without departing from the gist of the present invention. Of course, you can.

[0041]

Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention. [Example 1] Pandex T-5265HM (manufactured by Dainippon Ink and Chemicals, Inc.) as a urethane resin binder was dissolved in a 1/1 solution of diacetone alcohol / methyl ethyl ketone to prepare a 13% by weight binder solution. To 200 g of the binder solution, 52 g of fine yttrium oxide powder (produced by Nippon Yttrium Co., Ltd.) was added and dispersed by a homogenizer to prepare a coating material for forming the reflective layer 26. In addition, the D50% particle size of the yttrium oxide fine powder by a laser diffraction method is 1.4 μm, and the FSSS (Fisher sub-s
The average particle size by an ieve sizer (Fisher air permeation apparatus) is 0.4 μm.

After the viscosity of the paint was adjusted to 30 poise, the paint was filtered and defoamed, and applied to a 180 μm-thick polyethylene terephthalate support sheet 22 with a doctor blade (clearance 800 μm) to form a paint layer 28. After the paint layer 28 was air-dried for about 1 hour, a large amount of glass beads 24 having a diameter of about 800 μm (Hibee D24 manufactured by OHARA Co., Ltd., with a refractive index of 1.595) were sprayed on the paint layer 28.

Next, the beads 24 were weighed to about 100 g / cm ^2.
As shown in FIG. 3B, one layer of beads 24 is adhered to the entire surface of the paint layer 28 at a high density as shown in FIG. After the beads 24 not adhered to the paint layer 28 are removed by slanting and lightly wiping the support sheet 22, the beads 24 are pressed from above by a rubber roller, and the beads 24 are pressed until the beads 24 come into contact with the support sheet 22. 28. Thereafter, the paint layer 28 was completely dried (the binder was cured), and the optical collimator sheet 20 was completed.

With respect to the obtained optical collimator sheet, the luminous intensity of the light emitted from the light source, incident from the support sheet 22 side, and passing through the optical collimator sheet is measured, and the luminous intensity in the vertical direction becomes の of the vertical direction. The angle from was measured.
As a result, this angle was 17 °, and it was confirmed that the optical collimator sheet had good characteristics.

[Example 2] Calayat DPCA60 (caprolactone-modified dipentaerythritol hexaacrylate manufactured by Nippon Kayaku Co., Ltd.) which is a UV-curable binder
26 g, Irgacure 907 (polymerization initiator Nippon Ciba Geigy), 1 g, methyl ethyl ketone 100 g,
Dissolve in a mixed solvent of 73 g of diacetone alcohol, and add 13 g
A wt% binder solution was prepared. Into this binder solution, fine yttrium oxide powder 5 as in Example 1 was used.
By charging 2 g and dispersing with a homogenizer,
The paint for forming the reflection layer 26 was adjusted.

Except for using this paint, application of paint, drying for 1 hour, beads 24
Spraying, pressurizing beads 24, removing excess beads 24,
The beads 24 were brought into contact with the support sheet 22 by pressing. Next, after drying at 100 ° C. for 4 hours, ultraviolet rays are irradiated using an ultraviolet lamp to cure the paint layer 26,
The optical collimator sheet 20 was completed.

With respect to the obtained optical collimator sheet, the angle from the vertical direction at which the luminous intensity was の of the vertical direction was measured in the same manner as in Example 1. As a result, this angle is 1
It was confirmed that the optical collimator sheet had good characteristics of 6 °. From the above results, the effect of the present invention is clear.

[0048]

As described above in detail, according to the method of manufacturing the optical collimator sheet of the present invention, the diffused light is preferably condensed, and the collimated light having high directivity and high luminance is obtained. The obtained optical collimator sheet can be manufactured easily and with high production. By using this optical collimator sheet, it is possible to display a high-quality image with a wide viewing angle on an LCD or the like in which the distance from the image forming surface to the screen is relatively short by using the optical collimator sheet together with a light diffusion screen or the like. .

[Brief description of the drawings]

FIG. 1 is an exploded perspective view conceptually showing a display device using an optical collimator sheet manufactured by a method for manufacturing an optical collimator sheet of the present invention.

FIG. 2 is a conceptual diagram of an example of an optical collimator sheet manufactured by the method for manufacturing an optical collimator sheet of the present invention.

FIGS. 3A to 3D are conceptual diagrams for explaining a method of manufacturing an optical collimator sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Display apparatus 12 Liquid crystal panel 14 Backlight part 18 Housing 20 Optical collimator sheet 22 Support sheet 24 Bead 26 Reflection layer 28 Paint layer

Claims (1)

[Claims] A coating solution containing two or more solvents having different boiling points and a binder and having a light-scattering substance dispersed therein is applied to a transparent support. The light-transmitting spheres are scattered, and thereafter, the light-transmitting spheres that are not adhered to the coating liquid are removed. Further, after the light-transmitting spheres are pressed to contact the support, the coating liquid is cured. A method for manufacturing an optical collimator sheet, comprising: