JP4408942B1 - Linearly polarized light selective reflection screen - Google Patents

Abstract

Provided is a reflective screen that has a simple configuration, enables a large contrast even in a bright environment, and has a wide viewing angle.
At least an oriented film (1) and a light absorbing layer (2) laminated on the oriented film; the oriented film is dispersed in the oriented polymer matrix and the polymer matrix Having a scattering axis with the largest scattering for linearly polarized light and a transmission axis with the smallest scattering for linearly polarized light; and the oriented film has a specific optical A linearly polarized light selective reflection type screen (10) having special properties. This linearly polarized light selective reflection screen (10) can be used with a video projector (20) that projects an image by polarized light.
[Selection] Figure 1

Description

  The present invention relates to a linearly polarized light selective reflection type screen, and more particularly to a linearly polarized light selective reflection type screen for an image projector such as a liquid crystal projector.

  Video projectors (projection type display devices) are increasing in demand because they can realize a large screen display at a small size and at a lower cost than direct view type display devices. In particular, a video projector using a liquid crystal element as a two-dimensional optical switch, that is, a liquid crystal projector, unlike a video projector using a CRT projection tube, is capable of high-definition display without blurring to the periphery of the screen by a dod matrix display. Therefore, it is expected as a favorite of high-resolution digital television.

  Screens onto which images are projected by a video projector are roughly classified into a reflective screen for observing an image from the video projector side and a transmissive screen for observing an image from the opposite side of the video projector across the screen.

  Conventionally, as the reflective screen, a white screen that totally reflects the projection light from the video projector has been used. However, in recent years, a selective reflection type screen that selectively reflects only a specific polarized light has been proposed in order to improve the contrast of a reflection type screen that is used with a video projector that projects an image with polarized light, particularly a liquid crystal projector. In such a selective reflection type screen, the contrast of the displayed image is reflected by reflecting the polarized light projected from the image projector and transmitting and / or absorbing the polarized light in a different direction, that is, half of the ambient light. Has been improved.

  For example, Patent Documents 1 and 2 disclose a reflective screen of a circularly polarized reflection type using cholesteric liquid crystal. In these circularly polarized reflection type reflective screens, contrast is improved by reflecting specific circularly polarized light and absorbing circularly polarized light opposite thereto.

  Patent Document 3 proposes a reflective screen including a specular reflective polarizing element and a diffusing element that scatters polarized light reflected by the reflective polarizing element. Further, Patent Document 4 includes a diffuse reflective polarizing element and a second polarizer that transmits the polarized light that has passed through the diffuse reflective polarizing element, adjacent to the rear side of the diffuse reflective polarizing element. A device has been proposed.

  Patent Document 5 includes an oriented film having a scattering axis with the largest scattering with respect to linearly polarized light and a transmission axis with the smallest scattering with respect to linearly polarized light, and containing polymer fine particles in a polymer matrix. A screen in which a polymer matrix and polymer fine particles have specific refractive index anisotropy is disclosed.

JP-A-5-107660 JP 2005-17751 A Special Table 2002-540445 JP 2005-526283-A International Publication WO2006 / 009293

  The main object of the present invention is to provide a reflective screen that enables a large contrast, particularly a reflective screen that has a simple structure, enables a large contrast even in a bright environment, and has a wide viewing angle. Other objects and advantages of the present invention will become apparent from the following description.

  The present invention is as follows:

<1> having at least an oriented film and a light absorbing layer laminated on the oriented film;
The oriented film has an oriented polymer matrix and polymer fine particles dispersed in the polymer matrix, so that the scattering axis has the largest scattering with respect to linearly polarized light, and linearly polarized light. A transmission axis that minimizes scattering in the plane; and the oriented film satisfies the following formulas (1) to (4):
Linearly polarized light selective reflective screen:
| N _trans −n _trans | ≦ 0.050 (1)
0.080 ≦ | N _scat −n _scat | (2)
H _scat / H _trans > 1.50 (3)
H _scat −H _trans ≧ 30.0 (4)
(N _trans : refractive index in the transmission axis direction of the polymer matrix,
N _scat : refractive index in the scattering axis direction of the polymer matrix,
n _trans : refractive index in the transmission axis direction of the polymer fine particles,
n _scat : refractive index in the scattering axis direction of the polymer fine particles H _scat : haze value in the scattering axis direction of the oriented film H _trans : haze value in the transmission axis direction of the oriented film)
<2> The screen according to <1>, wherein the oriented film further satisfies the following formula (5):
1.510 ≦ n ≦ 1.580 (5)
[N: Average refractive index of polymer fine particles {(n _trans + n _scat ) / 2}]
<3> The screen according to <1> or <2> above, wherein the light absorbing layer does not have polarization selectivity.
<4> The content according to any one of <1> to <3>, wherein the content of the polymer fine particles in the oriented film is 0.01 to 40 parts by weight with respect to 100 parts by weight of the polymer matrix. Screen.
<5> The screen according to any one of <1> to <4>, wherein the polymer fine particles are fine particles having a core-shell structure.
<6> The screen according to any one of <1> to <5>, wherein the polymer matrix is made of polyethylene terephthalate.

  According to the linearly polarized light selective reflection type screen of the present invention, when used in combination with a video projector that projects an image by polarized light by combining an alignment film having specific optical properties and a light absorbing layer, A simple configuration provides the unexpected effect of allowing large contrast even in bright environments and providing a wide viewing angle.

As shown in FIG. 1, the linearly polarized light selective reflection type screen (10) of the present invention has at least a oriented film (1) and a light absorbing layer (2) laminated on the oriented film. Here, the oriented film has a polymer axis that is oriented, and a polymer axis that is dispersed in the polymer matrix, so that the scattering axis has the largest scattering with respect to the linearly polarized light, and the linearly polarized light. Has a transmission axis that minimizes scattering in the plane; and satisfies the following formulas (1) to (4):
| N _trans −n _trans | ≦ 0.050 (1)
0.080 ≦ | N _scat −n _scat | (2)
H _scat / H _trans > 1.50 (3)
H _scat −H _trans ≧ 30.0 (4)
(N _trans : refractive index in the transmission axis direction of the polymer matrix,
N _scat : refractive index in the scattering axis direction of the polymer matrix,
n _trans : refractive index in the transmission axis direction of the polymer fine particles,
n _scat : refractive index in the scattering axis direction of the polymer fine particles H _scat : haze value in the scattering axis direction of the oriented film H _trans : haze value in the transmission axis direction of the oriented film)

Here, the haze values (H _scat and H _trans ) of the oriented film are values (%) defined in accordance with JIS K7136, and are defined as the ratio of the diffuse transmittance τ _{d to} the total light transmittance τ _t .

Further, the refractive indexes (n _trans and n _scat ) in the transmission axis direction and the scattering axis direction of the polymer fine particles are the refractive indexes in the transmission axis direction and the scattering axis direction, respectively, measured as the entire polymer fine particle. That is, for example, when the polymer fine particles have a multi-layered structure of two or more layers (for example, core-shell type), n _trans and n _scat are the refractive indexes in the transmission axis direction and the scattering axis direction of the respective layers. Instead, it is the refractive index in the transmission axis direction and the scattering axis direction as a whole of the polymer fine particles.

The difference (| N _trans −n _trans |) between the refractive index of the polymer matrix and the refractive index of the polymer fine particles in the transmission axis direction of the above formula (1) is 0.050 or less, preferably 0.040 or less. More preferably, it is 0.035 or less. When this value is too large, the reflection / scattering of polarized light in the direction of the transmission axis included in the ambient light becomes large, thereby reducing the bright place contrast.

The difference (| N _scat −n _scat |) between the refractive index of the polymer matrix and the refractive index of the polymer fine particles in the scattering axis direction of the above formula (2) is 0.080 or more, preferably 0.090 or more. More preferably, it is 0.095 or more. When this value is too small, the scattering property with respect to the polarized light in the scattering axis direction becomes small, and the brightness of the image intended to be displayed on the screen decreases.

In the above formulas (3) and (4), the ratio of the haze value in the scattering axis direction to the haze value in the transmission axis direction and the difference (H _scat / H _trans and H _scat −H _trans ) The haze anisotropy of

Here, the value of the ratio (H _scat / H _trans ) between the haze value in the scattering axis direction and the haze value in the transmission axis direction of the above formula (3) is 1.50 or more, preferably 1.60 or more. Preferably it is 1.65 or more. In addition, the value of the difference (H _scat −H _trans ) between the haze value in the scattering axis direction and the haze value in the transmission axis direction in the above formula (4) is 30.0 or more, preferably 31.0 or more, more preferably. Is 32.0 or more. If these values are too small, the haze anisotropy of the alignment film with respect to the polarized light is insufficient, and it cannot be said that the film has sufficient selective scattering property with respect to the polarized light. It cannot be reflected or scattered.

In the screen of the present invention, the oriented film may further satisfy the following formula (5):
1.510 ≦ n ≦ 1.580, preferably 1.520 ≦ n ≦ 1.580 (5)
[N: Average refractive index of polymer fine particles {(n _trans + n _scat ) / 2}]

  If the average refractive index of the polymer fine particles is too large or too small, it may be difficult to match the refractive index of the polymer fine particles in the transmission axis direction with the refractive index of the polymer matrix in the transmission axis direction.

<Oriented film>
The orientation film (1) used in the linearly polarized light selective reflection type screen (10) of the present invention is laminated with the light absorbing layer (2) as shown in FIG. This oriented film has an oriented polymer matrix and polymer fine particles dispersed in the polymer matrix, so that the polarization direction (scattering axis) in which scattering is greatest with respect to linearly polarized light, and linear It has a polarization direction (transmission axis) that minimizes scattering with respect to polarized light. That is, when the polarized light coincides with the scattering axis, the polarized light is hardly transmitted to the opposite side of the oriented film and / or scattered and transmitted due to scattering in the oriented film. On the other hand, when the polarized light coincides with the transmission axis, there is little scattering in the oriented film, and therefore the polarized light is not scattered and easily transmitted to the opposite side of the oriented film.

  The thickness of the oriented film can be selected so as to obtain a desired optical property, and is preferably 0.1 to 500 μm, more preferably 5 to 100 μm.

<Oriented film-polymer matrix>
An oriented polymer matrix used for an oriented film, that is, a polymer matrix having a refractive index anisotropy with respect to polarized light, can be any polymer material, particularly any polymer material that is optically transparent. Can be made. Thus, for example, materials for the polymer matrix can include crystalline aromatic polyesters such as polyethylene terephthalate and polyethylene naphthalate, and more preferably polyethylene terephthalate. Use of such a crystalline polymer is preferable in that a difference in refractive index between the transmission axis and the scattering axis is likely to occur.

<Oriented film-polymer fine particles>
The polymeric microparticles used for the oriented film can be made of any polymeric material, especially any optically transparent polymeric material, preferably substantially compatible with the material for the polymeric matrix. Can be made of polymer material that does not. Therefore, for example, materials for polymer fine particles include acrylics such as polymethyl methacrylate resin, methacryl styrene resin (MS resin), acrylonitrile-styrene resin (AS resin), polystyrenes such as syndiotactic styrene resin, and polybutadienes. And other thermoplastic polymers. Examples of the material for the polymer fine particles include crosslinkable polymer materials such as a crosslinked acrylic resin and a crosslinked polystyrene resin.

  Examples of the shape of the polymer fine particles include a spherical shape, a spindle shape (rugby ball type), a circular shape, an elliptical shape, and a rectangular shape. By having one or more specific shapes in this way, the polymer fine particles reflect the light projected from the projector at a wider angle than in the case of a polymer alloy having a sea-island structure, thereby suppressing glare. Can do.

  The fine polymer particles may be fine particles made of a single polymer material or fine particles made of a plurality of types of polymer materials. For example, fine particles made of a plurality of types of polymer materials, particularly a core-shell type Fine particles having the following structure can be preferably used. The core-shell structure here refers to a two-layer structure in which fine particles have a central portion (core) and a surface layer (shell), but the boundary between the core and the shell is not necessarily clear. Therefore, for example, as the core-shell structure, a material composed of at least two kinds of polymer materials, that is, a polymer material that forms a core and a polymer material that forms a shell of the outermost layer can be exemplified. Specifically, as the core-shell structure, the core is formed of a homopolymer composed of monomer A, and from the outside of the core to the outermost portion of the shell is formed of a copolymer of monomer A and monomer B. In addition, a structure in which the proportion of the monomer A decreases as the copolymerization ratio moves away from the core can be given. Moreover, the core and the shell may be composed of polymers having completely different basic skeletons.

  As a form of dispersion of the polymer fine particles in the polymer matrix, it is preferable that the polymer fine particles are basically aligned with respect to the orientation direction of the molecular chains of the polymers constituting the polymer matrix. Before the treatment for orientation such as stretching, the fine polymer particles are usually dispersed in the polymer matrix as secondary aggregates due to the influence of the surface energy. By stretching this in, for example, a uniaxial direction, the polymer fine particles are aligned in the stretching direction. When a long and narrow light scatterer in which polymer fine particles are linked in this way is formed, shape anisotropy is added in addition to refractive index anisotropy, and the polarization selectivity of the alignment film is amplified.

  The average primary particle diameter of the polymer fine particles is preferably in the range of 0.01 μm to 10 μm, more preferably 0.05 μm to 1 μm, and even more preferably 0.05 μm to 0.50 μm. When the average particle size of the polymer fine particles is too small, the scattering efficiency may be insufficient. On the other hand, when the average particle diameter of the polymer fine particles is too large, voids are generated around the fine particles due to stress during production such as stretching of the oriented film, which may significantly impair the optical characteristics.

  The content of the polymer fine particles is preferably 0.01 to 40 parts by weight, more preferably 0.1 to 20 parts by weight, and even more preferably 0.2 to 15 parts by weight with respect to 100 parts by weight of the polymer matrix. It is. If the content of the polymer fine particles is too small, the haze value in the scattering axis direction of the oriented film cannot be sufficiently increased. On the other hand, if the content of the polymer fine particles is too large, the haze in the transmission axis direction of the oriented film is particularly large when the difference between the refractive index of the polymer matrix and the refractive index of the polymer fine particles is relatively large in the transmission axis direction. The value may be too large.

<Oriented film-production method>
The alignment film can be produced by any method. Therefore, for example, an oriented film is a film obtained by mixing a predetermined amount of a polymer material constituting a polymer matrix and a predetermined amount of polymer fine particles by melt kneading, and then using the obtained mixture by a method such as melt extrusion. And then obtained by uniaxially stretching the obtained film in one direction, for example, the film extrusion (longitudinal) direction (MD direction) or the width (transverse) direction (TD direction) perpendicular to the extrusion direction. it can.

  The stretching method of the oriented film is preferably continuous longitudinal uniaxial stretching or continuous transverse uniaxial stretching from the viewpoint of productivity. The stretching conditions can be appropriately selected depending on the polymer used. For example, when polyethylene terephthalate (PET) is used as a polymer, PET can be melt-kneaded with polymer fine particles, then formed into a film by melt extrusion, and the obtained film can be stretched at a temperature of usually 80 to 110 ° C. it can. A draw ratio can be normally selected in the range of 3 to 5 times. After stretching the film, a heat setting treatment can be performed at 120 to 180 ° C. The polymer matrix constituting the oriented film is preferably strongly uniaxially oriented. The oriented film may be stretched by normal uniaxial stretching or width-fixed uniaxial stretching or biaxial stretching as long as the polymer matrix constituting the oriented film can be strongly uniaxially oriented.

  As described above, the oriented film used in the present invention is manufactured by mixing the polymer material constituting the polymer matrix and the polymer fine particles by the melt kneading method, and then forming the film (forming a film) by the melting method. Can be used, so it is highly productive.

<Light absorbing layer>
The light absorbing layer (2) used in the linearly polarized light selective reflection type screen (10) of the present invention is laminated on the oriented film (1) as shown in FIG. This light absorbing layer can absorb the amount of the ambient light that is transmitted through the alignment film, that is, the polarized light in the direction of the transmission axis of the alignment film of the ambient light. According to this, the contrast, particularly the bright place contrast can be increased.

  Moreover, according to this light absorbing layer, the incidence of light from the back surface of the light absorbing layer, that is, the incidence of light from the surface opposite to the surface laminated on the alignment film of the light absorbing layer is prevented, Thereby, the contrast of the image projected on the linearly polarized light selective reflection type screen of the present invention can be improved.

  As this light-absorbing layer, any light-absorbing layer can be used, and in particular, any light-absorbing layer having substantially no polarization selectivity can be used. Therefore, examples of the light absorbing layer include a layer made of a polymer material such as polyethylene terephthalate (PET) colored black with a pigment or dye such as carbon black.

  The light absorbing layer can have any thickness. In determining the thickness of the light-absorbing layer, the handleability when laminated with an oriented film to form the polarization-selective reflective screen of the present invention, the degree of light blocking by the light-absorbing layer (that is, light transmittance) Etc. can be considered. Moreover, a light absorption layer can be laminated | stacked on an oriented film using an adhesive agent, an adhesive, etc. arbitrarily.

<Other layers>
The alignment film and the light-absorbing layer can be laminated directly using an adhesive, a pressure-sensitive adhesive, etc., but other layers such as a polarizing film can be interposed between the alignment film and the light-absorbing layer. A reinforcing layer may be disposed for reinforcing the selective reflection type screen. As such a reinforcing layer, a plate-like body, a cloth, or the like can be used. In addition, for example, when a substrate is further used to provide self-supporting property to the polarization-selective reflective screen of the present invention, the substrate may be laminated on the light-absorbing layer on the surface opposite to the oriented film. it can. As the base material in this case, for example, a plate made of a polymer material having a thickness of 0.5 to 10 mm can be used.

<Video projector>
As a video projector used for projecting an image on the polarization-selective reflective screen of the present invention, any video projector that projects an image by polarized light, particularly a liquid crystal projector, can be used. In addition, when the polarization direction of the image projector is not aligned with the projected colors (for example, three colors of RGB), it is necessary to align the polarization directions of those colors, for example, using a color select film of Color Link Co., Ltd. Can be done.

  When the polarization-selective reflective screen (10) of the present invention is actually used with the image projector (20), as shown in FIG. 1, the image projector (20) is used from the same side as the observer (30). An image is projected on a polarization selective reflection type screen (10). At this time, the direction of polarized light projected by the video projector is set to be directed to the scattering axis direction of the alignment film constituting the polarization selective reflection type screen.

  Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

1. Haze value The haze value is measured using a digital turbidimeter NDH-2000 (Digital Haze Meter NDH-2000) manufactured by Nippon Denshoku Industries Co., Ltd., which measures light transmittance, scattered light transmittance, parallel light transmittance, and the like. It was measured.

2. Refractive index The refractive index was measured using an Abbe refractometer 2-T (ATAGO Abbe refractometer 2-T) manufactured by ATAGO Co., LTD. In the fine polymer particles used in Examples and Comparative Examples, the refractive index in the transmission axis direction and the refractive index in the scattering axis direction were the same (n = n _trans = n _scat relationship).

3. Screen characteristic evaluation (contrast)
A color select manufactured by Color Link was installed on a liquid crystal projector (made by PLUS U4-131), and projected from an angle of 20 degrees below the screen. The contrast was obtained by measuring the brightness of white display and black display of the projector with a luminance meter (manufactured by Minolta Camera Co., Ltd., LS-110) at an angle of 0 °, and obtaining white brightness / black brightness. Here, the dark place contrast was measured in a dark room. The bright place contrast was measured under the condition that the illumination was turned on and the illuminance on the screen surface was 500 lux.

4). Screen characteristic evaluation (visual sensory test)
In the visual sensory test, the visual display quality test was performed under the same conditions as the photopic contrast measurement, and evaluated by ○ (good) and x (poor).

5). Screen characteristics evaluation (chromaticity difference and viewing angle characteristics)
The chromaticity difference (color misregistration) and viewing angle characteristics were evaluated by CONOSCOPE manufactured by autonic-MELCHERS. Here, the chromaticity difference is indicated by a difference in chromaticity coordinates measured in 5 ° increments within a range of ± 80 ° in the vertical and horizontal directions. As for the viewing angle characteristics, luminance was measured in 5 ° increments in the range of ± 80 ° to the left and right, and a range showing luminance of 50% or more with respect to the front luminance was taken as the viewing angle.

[Example 1]
85 parts by weight of polyethylene terephthalate (hereinafter referred to as “PET”) (manufactured by Teijin Ltd.) as a polymer material constituting the polymer matrix, and core-shell particles (manufactured by Mitsubishi Rayon, W-) as polymer particles 15 parts by weight of 300A (average refractive index 1.530), primary particle diameter 0.15 μm) were kneaded at 280 ° C. using a single-screw kneading extruder, formed into a film by melt extrusion, and continuously and perpendicular to the extrusion direction. In the width direction (TD direction), the film was uniaxially stretched 4.5 times at 80 ° C. and heat-set at 120 ° C. to obtain an oriented film having a thickness of 100 μm.

  The obtained oriented film was laminated with black PET using an adhesive (“SK Dyne” 1811L manufactured by Soken Chemical Co., Ltd.) to obtain a linearly polarized light selective reflection type screen of Example 1.

[Example 2]
85 parts by weight of PET as a polymer material constituting the polymer matrix, and core-shell fine particles as polymer fine particles (manufactured by Kureha Chemical Co., Ltd., paraloid BTA712J (average refractive index 1.540), primary particle diameter 0.10 μm) 15 weights The part was kneaded at 280 ° C. using a uniaxial kneading extruder, formed into a film by a melt extrusion method, and continuously stretched uniaxially at 80 ° C. in the width direction perpendicular to the extrusion direction at 120 ° C. This was carried out in the same manner as in Example 1 except that a heat setting treatment was performed to obtain an oriented film having a thickness of 110 μm.

[Example 3]
85 parts by weight of PET as a polymer material constituting the polymer matrix, and core-shell fine particles as polymer fine particles (manufactured by Kureha Chemical Co., Ltd., paraloid BTA712J (average refractive index 1.540), primary particle diameter 0.10 μm) 15 weights The part was kneaded at 280 ° C. using a uniaxial kneading extruder, formed into a film by a melt extrusion method, and continuously stretched uniaxially at 80 ° C. in the width direction perpendicular to the extrusion direction at 120 ° C. Was carried out in the same manner as in Example 1 except that a heat setting treatment was performed to obtain an oriented film having a thickness of 80 μm.

[Comparative Example 1]
A general white projector screen (manufactured by Sanwa Supply, PR-SC61) was used for comparison.

[Comparative Example 2]
90 parts by weight of a polyethylene naphthalate resin (manufactured by Teijin Ltd.) as a polymer material constituting the polymer matrix, and syndiotactic polystyrene (manufactured by Idemitsu Petrochemical Co., Ltd., Zalek 141AC (manufactured by Idemitsu Petrochemical Co., Ltd.)) Refractive index 1.582)) 10 parts by weight are kneaded at 300 ° C. using a single-screw kneading extruder, formed into a film by melt extrusion, and in the width direction perpendicular to the extrusion direction at a preheating temperature of 120 ° C. and a stretching temperature of 135 °. It was carried out in the same manner as in Example 1 except that uniaxial tenter stretching was performed 4.5 times, heat setting was performed at 170 ° C., and an oriented film having a thickness of 80 μm was obtained. The oriented film obtained here was a polymer alloy having a structure (sea island structure) in which a phase of syndiotactic polystyrene was dispersed in a polyethylene naphthalate resin.

[Comparative Example 3]
85 parts by weight of PET as a polymer material constituting the polymer matrix and core-shell particles as polymer particles (Rohm and Haas, Paraloid EXL2311 (average refractive index 1.470), primary particle size 0.4 μm) 15 parts by weight was kneaded at 280 ° C. using a uniaxial kneading extruder, formed into a film by melt extrusion, and continuously stretched uniaxially by 4.5 times at 80 ° C. in the width direction perpendicular to the extrusion direction. This was carried out in the same manner as in Example 1 except that a heat setting treatment was performed at 120 ° C. to obtain an oriented film having a thickness of 100 μm. The oriented film obtained here had a smaller ratio and difference between the haze value in the scattering axis direction and the haze value in the transmission axis direction than the oriented film of the example.

[Comparative Example 4]
As in Example 2, 85 parts by weight of PET as a polymer material constituting the polymer matrix, core-shell particles (manufactured by Kureha Chemical Co., Ltd., paraloid BTA712J (average refractive index 1.540), primary particles) Example 1 except that 15 parts by weight (diameter of 0.1 μm) were kneaded at 280 ° C. using a uniaxial kneading extruder, formed into a film by melt extrusion, and an unstretched 110 μm thick oriented film was obtained. It carried out like. The oriented film obtained here was not oriented because it was not stretched.

[Comparative Example 5]
97 parts by weight of PET as a polymer material constituting the polymer matrix, and core-shell fine particles as polymer fine particles (manufactured by Kureha Chemical Co., Ltd., paraloid BTA712J (average refractive index 1.540), primary particle diameter 0.1 μm) 3 weights The part was kneaded at 280 ° C. using a uniaxial kneading extruder, formed into a film by a melt extrusion method, and continuously stretched uniaxially at 80 ° C. in the width direction perpendicular to the extrusion direction at 120 ° C. Was carried out in the same manner as in Example 1 except that a heat setting treatment was performed to obtain an oriented film having a thickness of 80 μm. The orientation film obtained here had a smaller difference between the haze value in the scattering axis direction and the haze value in the transmission axis direction than the orientation film of the example.

  Tables 1 and 2 show the evaluation results of the linearly polarized light selective reflection type screens of Examples and Comparative Examples.

  As can be seen from Tables 1 and 2, the screens of Examples 1 to 3 of the present invention clearly have superior performance as compared with the screens of Comparative Examples 1 to 5, and in particular, the contrast and brightness of the bright place. It had excellent performance with respect to the visual sensory test. On the other hand, in the screens of Comparative Examples 1 and 3 to 5 in which the ratio and / or difference between the haze value in the scattering axis direction and the haze value in the transmission axis direction is small, the bright place contrast was clearly inferior. Further, in the screen of Comparative Example 2, although the bright place contrast was relatively excellent, a luminance peak was present at a specific angle, thereby narrowing the viewing angle.

FIG. 1 is a schematic view showing a screen of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Orientation film 2 Light absorption layer 10 Linearly polarized light selective reflection type screen 20 of this invention 20 Image projector which projects an image with polarized light 30 Observer

Claims (5)

An alignment film, and at least a light-absorbing layer laminated on the alignment film and having no polarization selectivity;
The oriented film has an oriented polymer matrix and polymer fine particles dispersed in the polymer matrix, so that the scattering axis has the largest scattering with respect to linearly polarized light, and linearly polarized light. And has a transmission axis in the plane that minimizes scattering;
The average primary particle diameter of the polymer fine particles is in the range of 0.05 μm to 0.50 μm; and the oriented film satisfies the following formulas (1) to (4):
Linearly polarized light selective reflective screen:
| N _trans −n _trans | ≦ 0.050 (1)
0.080 ≦ | N _scat −n _scat | (2)
H _scat / H _trans > 1.50 (3)
H _scat −H _trans ≧ 30.0 (4)
(N _trans : refractive index in the transmission axis direction of the polymer matrix,
N _scat : refractive index in the scattering axis direction of the polymer matrix,
n _trans : refractive index in the transmission axis direction of the polymer fine particles,
n _scat : refractive index in the scattering axis direction of the polymer fine particles H _scat : haze value in the scattering axis direction of the oriented film H _trans : haze value in the transmission axis direction of the oriented film) The screen according to claim 1, wherein the oriented film further satisfies the following formula (5):
1.510 ≦ n ≦ 1.580 (5)
[N: Average refractive index of polymer fine particles {(n _trans + n _scat ) / 2}]   The screen according to claim 1 or 2, wherein the content of the polymer fine particles in the oriented film is 0.01 to 40 parts by weight with respect to 100 parts by weight of the polymer matrix.   The screen according to claim 1, wherein the polymer fine particles are fine particles having a core-shell structure.   The screen according to claim 1, wherein the polymer matrix is made of polyethylene terephthalate.

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