JP2006209092A - Reflector for screen, and screen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reflector which makes contrast of image higher and can obtain the clear image, without being environmentally affected, by deterring the mixing of excess light, other than projection light, into the image under the actual usage environment, and eliminates the occurrence of deterioration in reflection characteristics and color unevenness, and is appropriate for a low-cost screen, and to provide the screen. <P>SOLUTION: The reflector for the screen is constituted of thermoplastic films of ≥50 in the number of laminations and is characterized in that the maximum reflectivity R1 to a polarized beam 1, made incident from a direction forming an angle of 10° with an axis perpendicular to a film plane in any one of the bands corresponding to RGB, is ≥70%; and the maximum reflectivity R2 to a polarized beam 2 with the perpendicular direction of the polarized beam 1 as a polarization plane is ≤60%; and further, the difference between the maximum value and the minimum value of R1 is set ≤20% within 1 m<SP>2</SP>. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a screen that displays an image by receiving light from a light source and a reflector for the screen.

  In recent years, an enlarged display on a screen using a liquid crystal projector, a slide projector or the like is generally performed. As this type of projector, for example, an illumination optical system that separates light beams emitted from a light source into light beams of each color of red (R), green (G), and blue (B) and converges them on a predetermined optical path, and RGB A liquid crystal panel (light valve) that light-modulates each color beam and a light combining unit that combines the light-modulated RGB color beams, and enlarges and projects the color image combined by the light combining unit onto the screen using a projection lens. There is something.

  Recently, a narrow band three primary color light source, for example, a laser oscillator that emits narrow band light of each RGB color, is used as a light source, and a RGB light beam is emitted using a grating light valve (GLV) instead of a liquid crystal panel. Spatial modulation projectors have also been developed.

  In such a projector, a projection screen is used. The projection screen is roughly classified into a transmission type and a reflection type. The transmissive screen transmits the projection light emitted from the projector behind the screen (rear projector) so that the projected image can be seen by the transmitted light. The reflective screen is a projector (front projector) The projection light irradiated from the front projector) is reflected so that the projected image can be seen by the reflected light. In either the transmission type or the reflection type, it has been conventionally necessary to darken the room in order to obtain an image with high brightness and high contrast.

  As such a projection screen, there are projection screens (for example, Patent Documents 1 and 2) that can obtain an image with high brightness and high contrast even in a bright place. The projection screen includes a reflector made of an optical multilayer film in which a high refractive index layer and a low refractive index layer are alternately laminated on a light-absorbing screen substrate, a light diffuser that scatters reflected light, and a protective film. Films are formed sequentially, reflecting only the three primary colors that make up the projection light, and transmitting the other light to be absorbed by the screen substrate, allowing high-contrast images to be displayed regardless of the projection environment. It is like that. However, in the conventional technology, the reflector constituting the screen is made of an inorganic material, so there is not much flexibility, and it is easy to get cracks and scratches during storage and repeated use, and the reflection characteristics deteriorate. There was a problem such as. In addition, since the film is formed by the sputtering method, there is a problem of high cost.

  On the other hand, several films in which thermoplastic resins are laminated in multiple layers have been proposed. For example, a film that selectively reflects a specific wavelength (for example, by selectively laminating resin layers having different refractive indexes in multiple layers) Patent Documents 3 to 5) and the like exist. Among these, a film that selectively reflects a specific wavelength acts as a filter that transmits or reflects specific light, and is used as a film for a backlight such as a liquid crystal display.

However, in the conventional technology, the uniformity of the reflection characteristics in a large area is insufficient when reflecting light of a specific narrow band such as RGB, so when a reflector is used, the color within the screen There is a problem that unevenness occurs, and extra light other than the projection light, such as light from the luminaire and outside light, is close to the wavelength of the light emitted from the projector, so it cannot be cut completely. It was difficult and caused a decrease in contrast in the bright room.
JP 2003-270725 A (page 2) JP 2004-138938 A (2nd page) Japanese Patent Laid-Open No. 3-41401 (2nd page) JP-A-4-295804 (page 2) Japanese translation of PCT publication No. 9-506837 (2nd page)

  In view of the above-described problems of the prior art, the present invention provides a reflector suitable for a low-cost screen that has high contrast and is less likely to cause deterioration of reflection characteristics and has no color unevenness in a bright room usage environment. The challenge is to provide a screen.

In order to solve the above-described problems, the screen reflector of the present invention is made of a thermoplastic film having a lamination number of 50 or more, and in any of the bands corresponding to RGB, the axis perpendicular to the film plane and 10 °. The maximum reflectance R1 with respect to the polarized light beam 1 incident from an angled direction is 70% or more, and the maximum reflectance R2 with respect to the polarized light beam 2 whose polarization plane is the vertical direction of the polarized light beam 1 is 60% or less. The difference between the maximum value and the minimum value of R1 is 20% or less within 1 m ² .

  The screen reflector according to the present invention is characterized by the above-described constituent elements. Therefore, in a use environment of a bright room, the reflection characteristics are hardly deteriorated with high contrast, and there is no color unevenness. A suitable reflector can be provided.

  In addition, since the reflection band is asymmetric with respect to the wavelength that gives the maximum reflectance and is tailored to the lower wavelength side, the incident angle of the projection light from the projector or the like is from the vertical direction of the screen. Even if it shifts, the contrast is less likely to decrease. In the present invention, “tailing” refers to the reflection on the lower wavelength side closest to A when the reflectance reaches the baseline with the reflection wavelength at the maximum reflectance for the polarized light beam 1 (R1) as the reference A. A case where | (A−n1) − (A−n2) | ≧ 20 nm is assumed when the wavelength is n1 and the reflection wavelength on the high wavelength side closest to A when the reflectance reaches the baseline is n2. . Then, it is assumed that tailing is performed in the direction where the absolute value when n1 and n2 are compared is larger.

  The screen reflector of the present invention needs to be composed of a thermoplastic resin. This is because it has flexibility, is less likely to be scratched or cracked due to deformation, and does not cause deterioration of reflection characteristics in an actual use environment, so that it is difficult to produce defects when used as a screen.

  In addition, the number of layers needs to be 50 or more. This is because even if the surface is scratched, most of the layers are not affected, and the deterioration of the reflection characteristics becomes small. Furthermore, in one of the bands corresponding to RGB, the maximum reflectance (R1) with respect to the polarized light beam 1 incident from a direction that forms an angle of 10 ° with the axis perpendicular to the film plane is 70% or more. It is necessary that the maximum reflectance (R2) with respect to the polarized light beam 2 whose surface is perpendicular to the polarized light beam 1 is 60% or less. This is because the polarized light emitted from the projector is efficiently reflected, but most of the external light is transmitted without being reflected, so that the brightness and contrast under bright light are improved. This is because even if the external light matches the emission wavelength from the projector, only one polarization component is reflected, so that the luminance of black becomes smaller while maintaining the luminance of white.

  Here, the band corresponding to RGB in the present invention specifically refers to a band where “R” is 600 nm to less than 700 nm, “G” is 500 nm to less than 600 nm, and “B” is 400 nm to less than 500 nm. More preferably, it means the three primary color bands in the vicinity of R (642 nm ± 25 nm), G (532 nm ± 25 nm), and B (457 nm ± 25 nm) constituting the projector light. The screen reflector of the present invention has a maximum reflectivity (R1) with respect to the polarized light beam 1 incident from a direction that forms an angle of 10 ° with an axis perpendicular to the film plane in any of the R, G, and B bands. ) Must be 70% or more, more preferably the maximum reflectance is 80% or more, and still more preferably 90% or more. A higher maximum reflectance is preferable because higher brightness and higher contrast can be obtained. Here, the maximum reflectance is defined as the maximum reflectance in each band corresponding to RGB. Moreover, the preferable upper limit of the maximum reflectance as a reflector is 120%. Further, the polarized light beam referred to in the present invention refers to positively polarized light, elliptically polarized light, and circularly polarized light, and refers to light (emitted light) that is vibrated strongly in a specific direction. This indicates light emitted from a polarization conversion optical system or an optical integrator optical system, or a polarization conversion integrator optical system in which these two technologies are fused.

  In the screen reflector of the present invention, the maximum reflectance (R2) for the polarized light beam 2 whose polarization plane is in the direction perpendicular to the polarized light beam 1 in a band corresponding to RGB must be 60% or less. More preferably, it is 50% or less, More preferably, it is 40% or less. When the maximum reflectance with respect to the polarized light 2 is 40% or less, the difference (R1−R2) between the maximum reflectance (R2) with respect to the polarized light 2 and the maximum reflectance (R1) with respect to the polarized light 1 becomes large. The emitted polarized light beam is reflected more efficiently, while part of the outside light is transmitted, so that high brightness and high contrast can be obtained.

The screen reflector of the present invention has a maximum reflectance (R2) with respect to the polarized light beam 2 of 60% or less in any of the bands corresponding to RGB at the positions of the four corners and the center in 1 m ² . In addition, the maximum reflectance (R1) for the polarized light beam 1 is required to be 70% or more, and the difference between the maximum value and the minimum value of R1 (hereinafter sometimes referred to as R1 distribution range) is 20% or less. It is necessary to be. This is because the reflection characteristics in a large area are homogenized, and the color unevenness in the screen becomes almost no problem when a reflector is used.

Preferably, the maximum reflectance distribution range is 10% or less. This is because it is difficult to visually perceive color unevenness, and it hardly causes a problem. More preferably, it is 5% or less. This is because even if the angle at which the screen is viewed is changed, it will be impossible to capture color irregularities. Moreover, it is preferable that the distribution range of the wavelength which gives the maximum reflectance within 1 m ² is 50 nm or less. More preferably, it is 25 nm or less. This is because high contrast can be obtained over a wide range.

  As a raw material used in the present invention, a thermoplastic resin is most suitable. For example, polyolefin resin such as polyethylene, polypropylene, polystyrene, and polymethylpentene, alicyclic polyolefin resin, polyamide resin such as nylon 6 and nylon 66, aramid resin, Polyester resin such as polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, polybutyl succinate, polyethylene-2,6-naphthalate, polycarbonate resin, polyarylate resin, polyacetal resin, polyphenylene sulfide resin, tetrafluoroethylene resin, trifluoride Fluorine resin, acrylic resin, such as ethylene resin, trifluorochloroethylene resin, tetrafluoroethylene-6fluoropropylene copolymer, vinylidene fluoride resin, Methacrylic resins, polyacetal resins, polyglycolic acid resins, polylactic acid resins, and the like. Among these, polyester is particularly preferable from the viewpoint of strength, heat resistance, and transparency. Further, these thermoplastic resins may be homo resins, copolymerized or blends of two or more. Also, in each thermoplastic resin, various additives such as antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, organic particles, thickeners, thermal stabilizers, lubricants, infrared absorbers, ultraviolet absorbers. An agent, a dopant for adjusting the refractive index, and the like may be added.

  Here, the polyester means a homopolyester or a copolyester that is a polycondensate of a dicarboxylic acid component skeleton and a diol component skeleton. Typical examples of the homopolyester include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, and polyethylene diphenylate. In particular, polyethylene terephthalate is preferable because it is inexpensive and can be used in a wide variety of applications.

  The copolyester of the present invention is preferably a polycondensate comprising at least three or more components selected from the following dicarboxylic acid component skeleton and diol component skeleton. Examples of the dicarboxylic acid skeleton component include terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 4 4,4'-diphenylsulfone dicarboxylic acid, adipic acid, sebacic acid, dimer acid, cyclohexanedicarboxylic acid and ester derivatives thereof. Examples of the glycol skeleton component include ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentadiol, diethylene glycol, polyalkylene glycol, and 2,2-bis (4 '-Β-hydroxyethoxyphenyl) propane, isosorbate, 1,4-cyclohexanedimethanol and the like.

  Particularly in the present invention, it is preferable that the thermoplastic resin film comprises a layer made of polyethylene terephthalate and a layer made of polyester copolymerized with cyclohexanedimethanol. More preferably, the thermoplastic resin film comprises a layer made of polyethylene terephthalate and a layer made of an ethylene terephthalate polycondensate having a copolymerization amount of cyclohexanedimethanol of 15 mol% or more and 60 mol% or less. By doing in this way, while having high reflective performance, the change of a reflective characteristic becomes small especially by heating, such as a bonding process.

  The thermoplastic film of the present invention includes a structure in which layers made of a thermoplastic resin A (A layer) and layers made of a thermoplastic resin B (B layer) are alternately laminated, and the A layer and the B layer are ordered in the thickness direction. Preferably, there is a portion having a laminated structure. That is, it is preferable that the order of arrangement in the thickness direction of the A layer and the B layer in the film of the present invention is not in a random state, and the order of arrangement of the third layer or more other than the A layer and the B layer is as follows. It is not particularly limited. Moreover, when it has C layer which consists of A layer, B layer, and thermoplastic resin C, it may be laminated | stacked by regular permutations, such as A (BCA) n, A (BCBA) n, A (BABCBA) n. More preferred. Here, n is the number of repeating units. For example, in the case of A (BCA) n where n = 3, this indicates that the layers are stacked in a permutation of ABCABCABCA in the thickness direction.

  Further, in the present invention, the thermoplastic film must have a lamination number of 50 layers or more. More preferably, the layer made of the thermoplastic resin A (A layer) and the layer made of the thermoplastic resin B (B layer) are alternately arranged. It is a laminated film of 50 layers or more including 25 layers or more. More preferably, each has 50 layers or more, and particularly preferably, each has 80 layers or more. If the structure in which the A layer and the B layer are laminated by 25 layers or more is not included, sufficient reflectance cannot be obtained. Further, the upper limit is not particularly limited, but it is preferably 1500 layers or less in consideration of a decrease in wavelength selectivity accompanying a decrease in stacking accuracy due to an increase in the size of the device and an increase in the number of layers. .

  Here, the refractive index difference in one direction of the A layer or the B layer is preferably 0.03 or more and 0.25 or less. More preferably, it is 0.05 or more, More preferably, it is 0.08 or more. When the refractive index difference is smaller than 0.03, a sufficient reflectance cannot be obtained, which is not preferable. Further, it is more preferable that the difference between the refractive index difference in one direction and the refractive index in the thickness direction in the plane of the A layer or the B layer is 0.03 or more because the angle dependency of the reflection band is reduced.

  In the present invention, it is preferable that at least one of the higher-order reflection bands has a reflectance of 30% or less. Here, the higher-order reflection band refers to the observed reflection peak on the highest wavelength side as the primary reflection peak, and the wavelength band X of the primary reflection peak is the order N (N is an integer of 2 or more). Each wavelength band X / N ± 25 nm obtained by dividing by. In addition, this ± 25 nm takes into consideration a measurement error and a peak reading error. Further, when at least one of the higher-order reflection bands has a reflectance of 30% or less, when the wavelength band X of the first-order reflection peak is composed of, for example, certain wavelength regions X1 to X2, in the section of X1 / N to X2 / N It means having at least one region having a reflectance of 30% or less. More preferably, at least one of the higher-order reflection band peaks has a reflectance of 20% or less, and more preferably has a reflectance of 15% or less. By having at least one higher-order reflection band having a reflectivity of 30% or less in this way, there is almost no coloration due to the higher-order reflection band, a decrease in color purity, or deterioration due to ultraviolet rays. It is suitable because it is difficult to get up. Further, if the reflectance is 15% or less, the level is almost the same as that of the surface reflection, so that it is optimal with almost no effect on coloring or a decrease in color purity.

  Further, it is more preferable that the order of the higher-order reflection band of the present invention is 2nd order or more and 4th order or less. More preferably, it is 2nd order or more and 3rd order or less. It is preferable that at least one second-order or fourth-order or lower reflection peak band having a reflectance of 30% or less does not occur due to coloring by a higher-order reflection band or a decrease in color purity.

The screen reflector of the present invention preferably has a thickness unevenness of 5% or less in the longitudinal direction and / or the width direction. In such a case, color unevenness due to thickness variation does not become a problem, and the clarity of the film becomes good, so that a reflector is bonded together and the screen is not slack. Further, when the thickness variation in the longitudinal direction and / or the width direction of the reflector is subjected to Fourier transform analysis, the Pw value at a wave number of 1 to 100 (1 / m) is preferably 0.5 or less. More preferably, it is 0.3 or less. In such a case, in the screen, color unevenness can hardly be detected visually. Here, the method of analyzing the fluctuation cycle of the film thickness is preferably a method in which the film thickness is continuously measured and evaluated by performing Fourier transform (hereinafter referred to as “FFT treatment”) of the obtained data. Used. As for FFT processing, for example, “Mathematics of Engineer 1” first edition (Kyoritsu Publishing Co., Ltd. Kyoritsu Zensho 516) etc. about the theory of Fourier transform, “Optical Engineering” first edition (Kyoritsu Publishing Co., Ltd.) etc. about FFT processing techniques As described. Here, Pw is obtained by converting the thickness change data into an absolute value of the thickness, and using the data obtained by converting the average value so as to be the center value of the thickness change, by FFT processing. It is the spectral intensity Pwn at a certain wave number, which is determined by the following equation when the real part is an and the imaginary part is bn.
Pwn = 2 (an ² + bn ² ) ^1/2 / N
n: Wave number (m-1)
N: Number of measurements In the screen reflector of the present invention, the reflection band is preferably asymmetric with respect to the wavelength giving the maximum reflectance, and is tailed to the low wavelength side. This is because even if the incident angle of projection light from a projector or the like deviates from the vertical direction of the screen, it is difficult for the contrast to decrease. In order to do this, it is preferable to widen the flow path 1.1 to 2 times in the thickness direction at the die position opening when the feed block is stacked and then supplied to the die. By doing so, the thickness of the reflector surface layer is reduced, and as a result, the reflection peak tails to the low wavelength side.

  In the reflector for a screen of the present invention, the absolute value | Y (MD) −Y (TD) | of the difference between the Young's modulus Y (MD) in the longitudinal direction and the Young's modulus Y (TD) in the width direction of the thermoplastic film is 1 GPa. The above is preferable. More preferably, it is 2 GPa or more, More preferably, it is 3 GPa or more. In such a case, the degree of polarization of the reflector increases due to the difference in orientation and crystallinity between the longitudinal direction and the width direction of the thermoplastic film, and more selectively reflects polarized light from a projector, etc. Since some of the components are less reflected, an image with high brightness and high contrast can be obtained without being affected by the projection environment. The contrast improves as the absolute value of the difference in Young's modulus increases. In addition, since it becomes a handling property and dimensional stability defect when it becomes 8 GPa or more, it is not preferable.

  In the screen reflector of the present invention, the difference (R1−R2) between the maximum reflectance (R1) for the polarized light beam 1 and the maximum reflectance (R2) for the polarized light beam 2 is preferably 30% or more. More preferably, it is 40% or more, More preferably, it is 50% or more. In such a case, by making the polarization direction of the projection light projected from the projector or the like the same as the polarization plane of the reflector, external light or the like different from the polarization plane of the reflector is transmitted without being reflected. For this reason, an image with high brightness and high contrast can be obtained without being affected by the projection environment. Also for this work, the greater the difference, the greater the effect of improving contrast.

  When the half width of the reflection band corresponding to RGB is substantially the same in the reflector for the screen, there is an overlap between the green light emission of the fluorescent lamp that is commonly used and the G reflection wavelength of the reflector. Therefore, in the reflector for a screen of the present invention, the half width of the reflection band corresponding to G is preferably 10 nm or more narrower than the half width of the reflection bands corresponding to R and B. More preferably, it is narrower than 15 nm.

  The screen reflector of the present invention has a total light transmittance of not less than 400 nm and less than 700 nm of 50% or more. High contrast can be obtained while improving the color purity. More preferably, the total light transmittance is 70% or more. This is because even higher contrast can be obtained even under bright light. The total light transmittance is more preferably 80% or less. This is because when the total light transmittance is greater than 80%, a color change due to an angle is likely to occur, and sufficient contrast is difficult to obtain.

  Further, the number of laminated thermoplastic films is 150 or more, the adhesive layer and the adhesive layer are not substantially included, and the maximum reflectance (R1) with respect to the polarized light beam 1 is 70% or more in each band corresponding to RGB. The reflector is preferably used. The reflector does not include an adhesive layer or adhesive layer, and is a thermoplastic film consisting of 150 or more layers, and there is a peak in each band corresponding to RGB. Therefore, it is necessary to attach a reflector corresponding to RGB. In addition, scattering at the bonding interface is reduced, resulting in higher definition display. In the band corresponding to RGB, it is preferable that the maximum reflectance (R1) with respect to the polarized light 1 is 70% or more, and the total light transmittance of 400 nm or more and less than 700 nm is 50% or more. This is because high contrast can be obtained while improving the color purity. When the RGB reflectors are integrated as described above, the total light transmittance is more preferably 75% or less. This is because when the total light transmittance is larger than 75%, a color change due to an angle is likely to occur, and it is difficult to obtain a sufficient contrast. Further, the number of stacked layers is more preferably 400 layers or more and 1500 layers or less so that the maximum reflectance is 90% or more in each of the RGB bands.

  Moreover, in the reflector of this invention, it is preferable to have a layer which has a polyethylene terephthalate of 3 micrometers or more as a main component on at least one surface of a laminated film. More preferably, it has a layer mainly composed of polyethylene terephthalate of 5 μm or more. Further, it is more preferable to have a layer mainly composed of polyethylene terephthalate of 3 μm or more on both sides. If there is no layer made of polyethylene terephthalate having a thickness of 3 μm or more, the reflectance distribution becomes abnormal when the surface is scratched or the like, which is not preferable.

  In the reflector of the present invention, it is preferable that layers other than the outermost layer contain substantially no particles having an average particle diameter of 20 nm to 20 μm. When particles having an average particle diameter of 20 nm or more and 20 μm or less are contained in the laminated film, it is not preferable because transparency is deteriorated or diffuse reflection occurs. Moreover, it is not preferable because only the stacking accuracy causes a sagging and there is a possibility that the reflection performance is lowered.

  The reflector of the present invention preferably has at least one absorption peak at 520 to 620 nm. In this case, since extra external light is absorbed, the band corresponding to G can be efficiently reflected, color unevenness due to color shift is reduced, and the contrast is further improved.

  The reflector of the present invention includes an easy adhesion layer, an easy slip layer, a hard coat layer, an antistatic layer, an abrasion resistant layer, an antireflection layer, a color correction layer, a color absorbing layer, an electromagnetic wave shielding layer, and an ultraviolet absorbing layer. Functional layers such as a printing layer, a metal layer, a transparent conductive layer, a gas barrier layer, a hologram layer, a release layer, an adhesive layer, an adhesive layer, a diffusion layer, and a lens layer may be added.

  The screen of the present invention must be composed at least of the above-described reflector and absorber. With such a configuration, it is possible to provide a low-cost screen that is less likely to cause deterioration of reflection characteristics in an actual use environment and that has no color unevenness. The screen of the present invention is preferably composed of a reflector that reflects the bands corresponding to RGB and an absorber that absorbs the entire visible light band. In this case, since the projection light from the projector can be efficiently reflected and excess external light can be absorbed, the contrast is further improved.

  The absorber in the present invention is for absorbing light transmitted through the reflector, and the absorber is preferably a substrate containing a black film or black paint. More preferably, the absorber has a thickness of 1 μm to 250 μm. When the absorber is thinner than 1 μm, when the reflector is bonded together under heating conditions, wrinkles or the like is generated or light absorption is insufficient, which is not preferable. On the other hand, when the thickness is 250 μm or more, the handling property becomes unsatisfactory, and when a screen is used, the winding property becomes insufficient, which is not preferable.

  The screen of the present invention preferably includes a diffuser and / or a lens body. Here, the diffuser scatters the light reflected by the reflector, and this greatly improves the visual field characteristics. As the diffuser, a glass having a diameter of about 1 μm to 5 mm, inorganic particles, a polymer dispersed therein, or a material having an uneven structure is preferable. The lens body is for reducing the directivity of the light reflected by the reflector, adjusting the directivity of the light incident on the reflector, and suppressing the angle dependence due to the incident light. For example, there is a microlens film on which a two-dimensional microlens array is formed, and the microlens may be a convex lens, a concave lens, or a combination of both. The microlens only needs to be about the same as or smaller than the pixel size. For example, lenses having a diameter of about 0.1 mm may be densely arranged in the plane.

  The screen diffuser of the present invention is preferably an anisotropic diffuser having a vertical diffusion angle FWHM of less than 45 ° and a horizontal diffusion angle FWHM of 45 ° or more. Here, FWHM indicates a full width at half maximum at a scattering angle of 0 ° of light incident at an incident angle of 0 ° (Full Width Half Maximum). When the horizontal diffusion angle FWHM is 45 ° or more, light with substantially uniform luminance is reflected in the horizontal direction, and a wide viewing angle is obtained. Also, when the vertical diffusion angle FWHM is less than 45 °, most of the external light such as illumination enters the screen from above, so the smaller the vertical diffusion angle, the more the external light that reflects in the viewer direction. The ratio becomes smaller and the contrast becomes higher. However, if the diffusion angle in the vertical direction is too narrow, there is a difference in luminance in the vertical direction within the screen surface. Therefore, the FWHM in the vertical direction is more preferably in the range of 20 ° to 40 °. When the image light is laser light, the surface shape pattern is preferably random from the viewpoint of preventing speckle pattern generation. Such an anisotropic diffuser has an anisotropic diffuser with shape irregularities formed on the surface, or needle-shaped fine particles with different refractive indexes such as glass fibers are oriented and dispersed in a transparent resin. It may be a diffuser.

  Further, the screen of the present invention preferably has a protective film, and the protective film protects the diffuser and the reflector from the outside, and can improve the quality and durability of the screen.

  In the screen of the present invention, the permutation of the arrangement of the units constituting the screen may be a protective layer, a diffuser, a B reflector, a G reflector, an R reflector, and an absorber from the light incident surface side. preferable. In this case, the surface is hard to be scratched, the visual field characteristics are good, and it is difficult to be influenced by external light, so that a high contrast can be obtained. In addition, since light having a shorter wavelength is more likely to be scattered, it is preferable that the B reflector is closer to the light incident side in order to reduce scattered light. Each of these units may be bonded with a commercially available adhesive or adhesive, and the diffuser or the surface protective layer may be formed on the surface of the reflector by coating.

  The screen of the present invention is suitable as a screen for a front type projector or a rear type projector, and is particularly suitable for a front type.

  Next, the preferable manufacturing method of the reflector of this invention is demonstrated below.

  Two types of thermoplastic resins A and B are prepared in the form of pellets. If necessary, the pellets are pre-dried in hot air or under vacuum and supplied to an extruder. In the extruder, the resin heated and melted to a temperature equal to or higher than the melting point is homogenized by a gear pump or the like, and foreign matter or denatured resin is removed through a filter or the like.

  The thermoplastic resin sent out from different flow paths using these two or more extruders is then sent into the laminating apparatus. As a laminating apparatus, a method of laminating in multiple layers using a multi-manifold die, a field block, a static mixer, or the like can be used. Moreover, you may combine these arbitrarily. Here, in order to efficiently obtain the effects of the present invention, a multi-manifold die or a feed block capable of individually controlling the layer thickness for each layer is preferable. Furthermore, in order to control the thickness of each layer with high accuracy, a feed block provided with fine slits for adjusting the flow rate of each layer by electric discharge machining or wire electric discharge machining with a machining accuracy of 0.1 mm or less is preferable. At this time, in order to reduce nonuniformity of the resin temperature, heating by a heat medium circulation method is preferable. Moreover, in order to suppress the wall resistance in the feed block, the roughness of the wall surface is preferably 0.4 S or less, or the contact angle with water at room temperature is 30 ° or more. By using such an apparatus, high stacking accuracy is achieved, so that it is easy to obtain a reflector having a maximum reflectance of 60% or more.

Here, in order that the maximum reflectance (R1) with respect to the polarized light beam 1 which is the first feature of the present invention is 70% or more, the A layer and the B layer are alternately laminated by 25 layers or more, It is important to have 50 layers or more. Further, the layer thickness of each layer needs to be designed so as to obtain a desired reflection performance based on the following formula 1, and the uniaxial refractive index and the layer thickness in each plane are in the range 40. % Distribution is acceptable. If there is a distribution larger than 40%, the half-value width of the reflection peak becomes too large, and there is a problem that contrast is lowered or color purity is lowered when a screen is formed. Moreover, in order that the maximum reflectance (R1) with respect to the polarized light beam 1 which is a more preferable embodiment of the present invention is 80% or more, the number of stacked layers is preferably 100 or more. Moreover, in order that the maximum reflectance (R1) which is a more preferable aspect of the present invention is 90% or more, the number of stacked layers is preferably 150 or more.
2 × (na · da + nb · db) = λ Equation 1
na: Refractive index in a certain uniaxial direction in the plane of the A layer nb: Refractive index in a certain uniaxial direction in the plane of the B layer da: Layer thickness (nm) of the A layer
db: Layer thickness of layer B (nm)
λ: main reflection wavelength (primary reflection wavelength)
Further, the maximum reflectance (R1) with respect to the polarized light beam 1 which is a feature of the present invention is 70% or more, and the maximum reflectance (R2) with respect to the polarized light beam 2 whose polarization plane is perpendicular to the polarized light beam 1 is 60% or less. In order to achieve this, the absolute value of the difference between the Young's modulus Y (MD) in the longitudinal direction and the Young's modulus Y (TD) in the width direction of the thermoplastic film is | Y (MD) −Y (TD) | ≧ 1 GPa It is preferable. As film forming conditions, a uniaxial direction with an unstretched film may be stretched by 2.3 times or less, and a uniaxial direction forming an angle substantially perpendicular to the stretching direction may be stretched by 4.0 times or more. In addition, when x is a uniaxial direction in the plane of the thermoplastic film composed of the thermoplastic resin a and the thermoplastic resin b and y is a uniaxial direction forming an angle substantially perpendicular to x, the x direction It is preferable to use a thermoplastic resin having an in-plane refractive index difference (nax-nby) of 0.04 or more and an in-plane refractive index difference (nay-nby) of 0.03 or less. In order to satisfy R1 ≧ 80% and R2 ≦ 50%, which is a more preferred embodiment of the present invention, it is preferable that | Y (MD) −Y (TD) | ≧ 3GPa. In this case, the unstretched film may be stretched 4.0 times or more in one direction by uniaxial stretching in the range of (Tga-10) (° C) or more and (Tga + 40) (° C) or less. Alternatively, it may be stretched by (Tga + 40) (° C.) or more and 2.2 times or less in a uniaxial direction in biaxial stretching and 5.0 times or more in a uniaxial direction forming an angle substantially perpendicular to this direction. In addition, a resin having an x-direction refractive index difference (nax-nbx) in the plane of the thermoplastic film of 0.05 or more and a y-direction refractive index difference (nay-nby) of 0.025 or less is used. preferable. Further, in order to satisfy R1 ≧ 90% and R2 ≦ 40%, which is a further preferred embodiment of the present invention, | Y (MD) −Y (TD) | ≧ 3 or more and unstretched film formation conditions The film is stretched 5.0 times or more in one uniaxial direction within the range of (Tga-10) (° C.) or more and (Tga + 30) (° C.) or less, and then (Tm + 90) (° C.) or more of the thermoplastic resin A. In order to have at least one higher-order reflection band having a reflectance of 30% or less, which is one of the preferred embodiments of the present invention, most of the adjacent A layer and B layer satisfy the following formula 2. It is good to have a simple layer structure. In order to efficiently obtain the effects of the present invention, it is preferable that the following formula 2 is satisfied, but it is acceptable even if a deviation of 10% or less occurs in a certain uniaxial refractive index and layer thickness in each plane. Is. In order to have at least one higher-order reflection band having a reflectance of 15% or less, which is a preferred embodiment of the present invention, the layer thickness deviation is 5% or less, and the layer thickness deviation is adjacent. Rather than being regular between layers, it is preferable to be random. For a reflector with a large area, the maximum reflectance is 80% or more, and very high stacking accuracy is required to satisfy Equation 2, but such stacking accuracy is easily and stably achieved by the conventional method. It was impossible to do. In order to achieve such high lamination accuracy, 100 to 300 fine slits having a surface roughness of 0.1 S or more and 0.6 S or less, particularly in discharge wire processing with a processing accuracy of 0.01 mm or less. It is particularly preferable to laminate with a feed block. Further, even if Equation 2 is not satisfied, the total light transmittance of not less than 400 nm and less than 700 nm is achieved by using the special feed block as described above, while the maximum reflectance is 70% or more in any of the RGB bands. % Or more can be achieved.
na · da = nb · db × (N−1) Equation 2
na: Refractive index in a certain uniaxial direction in the plane of the A layer nb: Refractive index in a certain uniaxial direction in the plane of the B layer da: Layer thickness (nm) of the A layer
db: Layer thickness of layer B (nm)
N: degree (integer of 2 or more)
In the present invention, it is preferable to adjust the thickness of each layer in the laminating apparatus so that the distribution range of the thickness ratio of the adjacent A layer and B layer in a certain cross section is 5% or more and 40% or less. More preferably, it is 10% or more and 30% or less. If the thickness ratio distribution is smaller than 5%, the repetition periodicity of the layer is too high, and high-order reflection is very likely to occur. Further, when it is larger than 40%, since the lamination accuracy is too low, not only the reflectance of the desired band is lowered, but also a reflection peak appears in an unexpected wavelength band, and the half width of the reflection peak becomes too large, When a screen is used, there are problems that the contrast is lowered and the color purity is lowered.

  In order to achieve the order of the higher-order reflection band having a reflectance of 30% or less, which is a preferred embodiment of the present invention, from 2nd to 4th, N in Formula 2 is 2 or more and 4 or less. Is preferred.

In the present invention, the distribution range of the maximum reflectance (R1) for the polarized light beam 1 in the band corresponding to RGB within 1 m ² must be 20% or less. For this purpose, as a laminating apparatus, it is preferable to use at least a feed block having fine slits as shown in FIGS. 2 and 4, and the number of slits is preferably 50 or more. Here, FIG. 2 is a conceptual plan view of each part of the feed block having the fine slit 3. FIG. 3 is a three-dimensional view thereof. In FIG. 2, members 1 to 5 are stacked in this order to form a stacking device 6. 2 and 3, the thermoplastic resin A is supplied from the upper part of 2 and distributed to the slits 3b. Moreover, the thermoplastic resin B is supplied from the upper part of 4, and is distributed to the slit of 3a. And each resin which passed the slit merges and is laminated | stacked in a multilayer. The ridge line 10 at the top of each slit in the slit member has an inclination with respect to the thickness direction of the slit member (FIGS. 3B and 3C). Here, as shown in FIG. 2, the slit area on the thermoplastic resin supply surface side and the slit area on the non-supply surface side are preferably not the same as the slit shape. Further, (the slit area on the non-supply side of the thermoplastic resin) / (the slit area on the supply surface side) is preferably 50% or less. In this case, the distribution range can be easily made 10% or less. More preferably, the pressure loss in the feed block is 1 MPa or more, and further preferably the slit length (Z-direction slit length in the figure) is 100 mm or more. By these, it becomes easy to make a distribution range into 5% or less. It is also preferable to have a manifold corresponding to each slit inside the feed block. By these methods, the flow velocity distribution in the width direction (Y direction in the figure) inside the slit is made uniform, so that the lamination ratio in the width direction of the laminated films is also made uniform, and reflection within a large area. The rate distribution is small.

  The molten laminate thus obtained is then formed into a target shape by a die and then discharged. Here, as the die to be molded into a sheet shape, it is preferable that the widening ratio of the laminated body in the die is 1 to 100 times. More preferably, it is 1 to 50 times. When the width-expansion ratio of the laminated body in the die is larger than 100 times, the disturbance of the laminated thickness of the surface layer of the laminated body increases, which is not preferable. When the widening ratio of the laminate in the die is 1 to 100 times, the distribution range of the maximum reflectance (R1) with respect to the polarized light beam 1 in the band corresponding to RGB can be easily set to 10% or less. In addition, the total light transmittance from 400 nm to 700 nm can be easily set to 70% or more. In addition, in order to make the maximum reflectance distribution range of the band corresponding to RGB 5% or less, the flow path widening ratio in the film thickness direction is doubled in the flow path process in which the melt lamination flows in a laminar flow state. It is also preferable that: In this way, the total light transmittance can be 80% or more. Once the molten laminate laminated with high accuracy is widened in the flow path by more than twice in the thickness direction, the flow velocity in the surface layer becomes too larger than the flow velocity in the central portion, and the lamination thickness gradually increases in the film thickness direction. When an extremely inclined structure that changes is formed, and the width is increased in order to form the sheet into a sheet shape (the channel is expanded in the film width direction), the inclined structure of the laminate in the center in the width direction where the flow velocity is high is further expanded. For this reason, it is difficult for the resulting sheet to have a reflectance difference of 5% or less in the width direction.

  Moreover, the reflector which is a preferred embodiment of the present invention is a thermoplastic film which does not include an adhesive layer or an adhesive layer and has a lamination number of 150 layers or more, and has a maximum reflectance with respect to polarized light 1 in each band corresponding to RGB. In order to obtain a reflector having a total light transmittance of not less than 70% and not less than 400 nm and less than 700 nm of 50% or more, it is preferable to use a feed block as shown in FIG. FIG. 4 illustrates a feed block composed of three independent fine slit portions, each of which has a laminated structure as a reflector corresponding to R, G, and B. In FIG. 4, members 13 to 21 are stacked in this order to form a stacking device 22. 4 has four resin introduction ports derived from the resin introduction portions 14, 16, 18, and 20, for example, the resin A is supplied from the introduction ports 23 of the resin introduction members 14 and 18, and the resin B Is supplied from the introduction port 25 of the resin introduction members 16 and 20. Then, the slit member 15 receives the resin A from the resin introduction member 14 and the resin B from the resin introduction member 16, and the slit member 17 supplies the resin A from the resin introduction member 18 and the resin B from the resin introduction member 16. The slit member 19 receives the supply of the resin A from the resin introduction member 18 and the resin B from the resin introduction member 20.

  Here, the type of resin introduced into each slit is the liquid reservoir 24 in the resin introduction members 14 and 18, the bottom surface of the liquid reservoir 26 in the resin introduction members 16 and 20, and the end of each slit in the slit member. It is determined by the positional relationship. That is, as shown in FIG. 5, the ridge line at the top of each slit in the slit member has an inclination with respect to the thickness direction of the slit member (FIGS. 5B and 5C). And the height of the bottom face of the liquid reservoir part of the resin introduction members 14, 16, 18, 20 is located at a height between the upper end part 28 and the lower end part 29 of the ridge line 27. Accordingly, resin is introduced from the liquid reservoirs 24 and 26 of the resin introduction members 14, 16, 18, and 20 from the side where the ridge line 27 is raised (30 in FIG. 6), but the ridge line 27 is lowered. From the side, the slit is sealed and no resin is introduced. Thus, since the resin A or B is selectively introduced for each slit, a resin flow having a laminated structure is formed in the slit members 15, 17, 19, and the outlets below the members 15, 17, 19 are formed. 31 flows out. The shape of the slit is as shown in FIG. 5, and the preferred form is as described above. FIG. 7 shows a case where the laminated fluids laminated at each fine slit are merged and further integrated. The thermoplastic resin laminate laminated in the fine slit portion 15 is supplied to the 33L portion, from 17 to the 34L portion, from 19 to the 35L portion, and from the LL ′ to the MM ′ in the junction device 32. In this way, the arrangement is changed by restricting the flow path (33M, 34M, and 35M in FIG. 7), and the laminated structure of the three resin flows is also in series. The resin flow is widened from M-M ′ to N-N ′ in FIG. 7 and merges downstream from N-N ′ in FIG. 7. In the conventional apparatus, when the number of stacked layers is 300 layers or more, a static mixer is used in combination with a feed block of about 200 layers. However, a reflector having a reflection peak with a narrow half-value width in each of the R, G, and B bands is used. Couldn't get. This is because, in order to obtain a band corresponding to R, G, and B, the layers must be made of laminates having different layer thicknesses. When a static mixer is used, the layer thickness gradually changes, and half This is because the price range widens. In addition, if only a feed block as shown in FIG. 2 is used without using a mixer, if there are more than 300 layers, there is a problem that the layer thickness cannot be controlled due to a modified polymer due to thermal deterioration or the length in the X direction is too long. .

  In addition, in order to obtain a reflector for a screen in which the half-value width of the reflection band corresponding to G is 10 nm or more narrower than the half-value width corresponding to R and B, which is a preferred embodiment of the invention, Then, when forming a G film, the flow rate of the resin from the laminating apparatus to the die is slowed by 10% or more, or the thickness-direction widening ratio of the flow path shape from the laminating apparatus to the die is made 100% or more and 200% or less Is preferred.

  And the sheet | seat laminated | stacked in the multilayer discharged | emitted from die | dye is extruded on cooling bodies, such as a casting drum, and is cooled and solidified, and a casting film is obtained. At this time, using a wire-like, tape-like, needle-like or knife-like electrode, it is brought into close contact with a cooling body such as a casting drum by electrostatic force and rapidly cooled and solidified, or from a slit-like, spot-like, or planar device. A method in which air is blown out and brought into close contact with a cooling body such as a casting drum and rapidly cooled and solidified, and a method in which the nip roll is brought into close contact with the cooling body and rapidly solidified is preferable. In particular, in the Fourier analysis of thickness variation, in order to set the Pw value at a wave number of 1 to 100 (1 / m) to 0.5 or less, a tape-like electrode is used and a cooling body such as a casting drum is applied by electrostatic force. A method of close contact and rapid solidification is preferred.

  Here, when making the casting film, if the die lip gap is adjusted and the draft ratio (lip gap / casting film thickness) is 15 or less, the thickness unevenness in the longitudinal direction and / or the width direction can be easily set to 5% or less. In addition, when the Fourier transform analysis is performed on the thickness variation in the longitudinal direction and / or the width direction of the reflector, the Pw value at a wave number of 1 to 100 (1 / m) can be easily set to 0.5 or less. preferable. Further, it is more preferable that the melt viscosity at 270 ° C. of the thermoplastic resin A and / or the thermoplastic resin B is 3200 poise or more and the resin temperature is 275 ° C. or less because the Pw value is easily 0.3 or less.

  The casting film thus obtained is preferably biaxially stretched as necessary. Biaxial stretching refers to stretching in the longitudinal direction and the width direction. Stretching may be performed sequentially biaxially or simultaneously in two directions. Further, the film may be redrawn in the longitudinal and / or width direction. In particular, in the present invention, it is preferable to use simultaneous biaxial stretching from the viewpoint of suppressing in-plane orientation difference and suppressing surface scratches.

  First, the case of sequential biaxial stretching will be described. Here, stretching in the longitudinal direction refers to stretching for imparting molecular orientation in the longitudinal direction to the film, and is usually performed by a difference in peripheral speed of the roll, and this stretching may be performed in one step. Alternatively, a plurality of roll pairs may be used in multiple stages. Although it changes with kinds of resin as a magnification of extending | stretching, 2 to 15 times is preferable normally, and when polyethylene terephthalate is used for either of the resin which comprises a laminated | multilayer film, 2 to 7 times are used especially preferably. Moreover, as extending | stretching temperature, the glass transition temperature-glass transition temperature +100 degreeC of resin which comprises a laminated | multilayer film are preferable.

  The uniaxially stretched film thus obtained is subjected to surface treatment such as corona treatment, flame treatment, and plasma treatment as necessary, and then functions such as slipperiness, easy adhesion, and antistatic properties are provided. It may be applied by in-line coating.

  The stretching in the width direction refers to stretching for giving the film an orientation in the width direction. Usually, the tenter is used to convey the film while holding both ends of the film with clips, and the film is stretched in the width direction. Although it changes with kinds of resin as a magnification of extending | stretching, 2 to 15 times is preferable normally, and when polyethylene terephthalate is used for either of the resin which comprises a laminated | multilayer film, 2 to 7 times are used especially preferably. Moreover, as extending | stretching temperature, the glass transition temperature-glass transition temperature +120 degreeC of resin which comprises a laminated | multilayer film are preferable.

  The biaxially stretched film is preferably subjected to a heat treatment at a temperature not lower than the stretching temperature and not higher than the melting point in the tenter in order to impart flatness and dimensional stability. After being heat-treated in this way, it is gradually cooled down uniformly, then cooled to room temperature and wound up. Moreover, you may use a relaxation process etc. together in the case of annealing from heat processing as needed.

  Next, the case of simultaneous biaxial stretching will be described. In the case of simultaneous biaxial stretching, the difference between the maximum value and the minimum value of the peak top reflectance in the band corresponding to RGB in the screen area is easily set to 20% or less, which is preferable. In the case of simultaneous biaxial stretching, the resulting cast film is subjected to surface treatment such as corona treatment, flame treatment, and plasma treatment as necessary, and then, such as slipperiness, easy adhesion, antistatic properties, etc. The function may be imparted by in-line coating.

  Next, the cast film is guided to a simultaneous biaxial tenter, and conveyed while holding both ends of the film with clips, and stretched in the longitudinal direction and the width direction simultaneously and / or stepwise. As simultaneous biaxial stretching machines, there are pantograph method, screw method, drive motor method, linear motor method, but it is possible to change the stretching ratio arbitrarily and drive motor method that can perform relaxation treatment at any place or A linear motor system is preferred. Although the stretching magnification varies depending on the type of resin, it is usually preferably 6 to 50 times as the area magnification. When polyethylene terephthalate is used as one of the resins constituting the laminated film, the area magnification is 8 to 30 times. Is particularly preferably used. In particular, in the case of simultaneous biaxial stretching, it is preferable to make the stretching ratios in the longitudinal direction and the width direction the same and to make the stretching speeds substantially equal in order to suppress the in-plane orientation difference. Moreover, as extending | stretching temperature, the glass transition temperature-glass transition temperature +120 degreeC of resin which comprises a laminated | multilayer film are preferable.

  The film thus biaxially stretched is preferably subsequently subjected to a heat treatment not less than the stretching temperature and not more than the melting point in the tenter in order to impart flatness and dimensional stability. In order to suppress the distribution of the main alignment axis in the width direction during this heat treatment, it is preferable to perform a relaxation treatment in the longitudinal direction immediately before and / or immediately after entering the heat treatment zone. After being heat-treated in this way, it is gradually cooled down uniformly, then cooled to room temperature and wound up. Moreover, you may perform a relaxation | loosening process in a longitudinal direction and / or the width direction at the time of annealing from heat processing as needed.

  In addition, in the present invention, when used in a large area such as a screen, an instantaneous spectroscope is installed in the width direction before the winding portion of the film forming process so as not to cause a problem as uneven color, and the reflection characteristics in the width direction. Preferably, the distribution is measured in-line, and the measurement result is fed back to the operation of the die lip gap adjusting bolt. By doing so, color unevenness in the width direction can be greatly reduced. Here, it is more preferable to feedback-control the measurement result of the conventional non-contact thickness meter together with the feedback control of the reflection characteristic. By doing so, it becomes easy to obtain a reflector for a screen that has no color unevenness and good flatness and is easy to bond. The obtained reflector for the screen becomes a screen by bonding the polarizing layer and / or the protective layer, the diffuser, the B reflector, the G reflector, the R reflector, and the absorber in this order from the light incident surface side. . The screen of the present invention is suitable as a screen for a front type projector or a rear type projector, and is particularly suitable for a front type.

  Moreover, as a method for obtaining a reflector for a screen having an absorption band at least at 570 to 620 nm and / or 520 to 580 nm, which is a preferred embodiment of the present invention, the surface of the reflector of any of R, G, and B is used. A coating solution in which the specific wavelength absorbing dye is dissolved may be applied during the production process of the specific wavelength absorbing dye or on the film after the production. Specific wavelength-absorbing dyes are classified into pigments (organic / inorganic) and dyes, and dyes are preferred in consideration of solubility in solvents. Examples of dyes include cyanine, quinoneimine, triphenylmethane, diphenylmethane, azo, indigoid, anthraquinone, quinone-hydroquinone redox, acridine, xanthene, azine, oxazine, and thiazine. It is done. In particular, anthraquinone, cyanine, tetraazeporphyrin compounds, dicyanoethylene compounds, and the like are preferable from the viewpoints of dispersibility in a solvent, wavelength absorption characteristics, and the like. Among them, SD50-E09V (Sumitomo Seika Co., Ltd.), TAP-2 (Yamada Chemical Co., Ltd.), TY171, TY100 (Adeka) and the like are more preferable in terms of wavelength absorption peak and absorption wavelength. Examples of the solvent for dissolving the dye include water, ethyl acetate, methyl ethyl ketone, toluene, and acetone. However, since selection of the solvent shifts the absorption wavelength depending on the compatibility with the dye, it is preferable to select a solvent having a desired absorption wavelength.

  Further, in order to obtain an anisotropic diffuser which is a preferred embodiment of the present invention, for example, an abrasive material such as alumina particles and silica particles is sprayed on the surface of a mold base material with an blast gun from an angle of less than 90 °. There is a method of forming a fine engraving surface having an uneven shape and replicating the fine engraving surface on the resin surface directly or indirectly using this sandblasted mold. In this method, the anisotropic diffusion characteristics of the diffusion plate can be controlled by changing the spraying conditions such as the abrasive spray angle.

An evaluation method of physical property values used in the present invention will be described.
(Method for evaluating physical properties)
(1) Lamination Thickness, Number of Laminations The layer configuration of the film was determined by observation with an electron microscope for a sample cut out of a cross section using a microtome. That is, using a transmission electron microscope HU-12 (manufactured by Hitachi, Ltd.), the cross section of the film was magnified 40000 times, a cross-sectional photograph was taken, and the layer structure and each layer thickness were measured. The embodiment of the present invention was not used because sufficient contrast was obtained, but the contrast may be increased by using a dyeing technique using RuO ₄ or OsO ₄ depending on the combination of the thermoplastic resins used.

(2) Reflectance A Φ60 integrating sphere 130-0632 (Hitachi Ltd.) and a 10 ° inclined spacer were attached to a spectrophotometer (U-3410 Spectrophotometer) manufactured by Hitachi, Ltd., and the reflectance was measured. The band parameter was set to 2 / servo, the gain was set to 3, and the range from 187 nm to 2600 nm was set to 120 nm / min. Measured at a detection speed of. In order to standardize the reflectance, an attached BaSO ₄ plate was used as a standard reflecting plate. In order to obtain a polarized light beam, a polarizing film made by Nitto Denko was installed on the surface of the sample on the light source side so that the polarization direction was up and down. The reflectance with respect to the polarized light beam 1 indicates the reflectance in the direction in which the reflectance of the film is highest, and the reflectance with respect to the polarized light beam 2 is obtained by rotating the sample placed with the polarized light beam 1 by about 90 °. The reflectivity in angle is shown. In Tables 1 to 4, the maximum reflectance is the measurement result at a location corresponding to the center of the screen. Moreover, the distribution range described the result of having measured about the center part and four corners in 1 m < ² >.

(3) Intrinsic viscosity Calculated from the solution viscosity measured at 25 ° C in orthochlorophenol. The solution viscosity was measured using an Ostwald viscometer. The unit is [dl / g]. The n number was 3, and the average value was adopted.

(4) Film thickness fluctuation The thickness thickness unevenness and the width direction thickness unevenness were measured using an Anritsu Co., Ltd. film thickness tester “KG601A” and an electronic micrometer “K306C”. Regarding the thickness unevenness in the longitudinal direction, the thickness of a film sampled 30 mm wide and 10 m long was continuously measured. In the width direction, the thickness was continuously measured for a length of 1 m. The film thickness unevenness was obtained by dividing the difference between the maximum thickness and the minimum thickness within the measured range by the average thickness and multiplying by 100 (%). In addition, about this film thickness nonuniformity, it measured by n number 5 times.

(5) Fourier analysis of longitudinal thickness variation of film At the time of measuring the longitudinal thickness variation described above, the output from the electronic micrometer was digitized using KEYENCE “NR-1000” and incorporated into a computer. The sampling rate and the winding speed were adjusted so that the data was sampled at 1024 points at a measurement length of 10 m. The numerical data taken in this way was converted into a quantitative thickness using Microsoft Excel 2000), and a Fourier transform (FFT) process was performed on the thickness variation. At this time, the thickness change data was converted into an absolute value of the thickness, and the average value was converted to the center value of the thickness change and used for analysis. At this time, if the length (m) of the film is taken as a variable in the flow direction, an intensity distribution with respect to the wave number (1 / m) is obtained by FFT processing. Here, the obtained real part a _n, when the imaginary part and b _n, spectral intensity Pw ⁿ can be expressed as the following equation.
^{_{Pw n = 2 (a n 2}} + b n 2) 1/2 / N
n: Wave number (m ⁻¹ )
N: 1024 (number of measurements).

(6) Total light transmittance Using a spectrophotometer (U-3410 Spectrophotometer) manufactured by Hitachi, Ltd., transmittance in the range of 400 nm to 700 nm was measured in the transmission mode. The transmittance for each wavelength (every 1 nm) was added and divided by the number of measurement points (number of wavelength points) to calculate a transmittance average value in the range of 400 nm to 700 nm to obtain the total light transmittance (%). The band parameter was set to 2 / servo, the gain was set to 3, and the range from 187 nm to 2600 nm was set to 120 nm / min. Measured at a detection speed of.

(7) Young's modulus It measured using the Instron type tensile tester according to the method prescribed | regulated to JIS-K7127 (1999). The measurement was performed under the following conditions.
Measuring device: “Tensilon AMF / RTA-100” automatic tensile strength measuring device manufactured by Orientec Co., Ltd.
Sample size: width 10mm x test length 50mm
Pulling speed: 300mm / min
Measurement environment: temperature 23 ° C., humidity 65% RH.

(8) Transmittance A transmittance was measured by attaching a φ60 integrating sphere 130-0632 (Hitachi, Ltd.) to a spectrophotometer (U-3410 Spectrophotometer) manufactured by Hitachi, Ltd. The band parameter was set to 2 / servo, the gain was set to 3, and the range from 187 nm to 2600 nm was measured at a detection speed of 120 nm / min. In order to standardize the transmittance, an attached BaSO ₄ plate was used as a standard white plate. In order to obtain a polarized light beam, a polarizing film made by Nitto Denko was installed on the surface of the sample on the light source side so that the polarization direction was up and down. The transmittance for the polarized light 1 indicates the transmittance for the polarized light in the same direction as R1, and the transmittance for the polarized light 2 indicates the transmittance for the polarized light in the same direction as R2. In Tables 1 to 4, the maximum reflectance is the measurement result at a location corresponding to the center of the screen.

Example 1
1. Example of Manufacturing R Reflector A thermoplastic resin A and a thermoplastic resin B were prepared as two types of thermoplastic resins. In Example 1, polyethylene terephthalate (PET) [Toray F20S] having an intrinsic viscosity of 0.65 was used as the thermoplastic resin A. The melt viscosity of this PET at 270 ° C. was 2600 poise. Further, as a thermoplastic resin B, polyethylene terephthalate (CHDM copolymerized PET) obtained by copolymerizing 30 mol% of cyclohexanedimethanol with ethylene glycol (PETG6763 manufactured by Eastman) and polyethylene terephthalate having an intrinsic viscosity of 0.65 at a weight ratio of 85:15. A resin kneaded and alloyed with a twin-screw extruder was used. The melt viscosity at 270 ° C. of this raw material was 4500 poise. These thermoplastic resins A and B were each dried and then supplied to an extruder. The resin temperature was 270 ° C.

  Thermoplastic resins A and B were each melted at 270 ° C. by an extruder, passed through a gear pump and a filter, and then joined by a feed block having 201 fine slits as shown in FIG. A structure in which 101 layers of A and 100 layers of thermoplastic resin B are alternately stacked in the thickness direction was used. The slit shape of the feed block was 45% (slit area on the thermoplastic resin non-supply side) / (slit area on the supply side), and the slit length was 100 mm. In addition, both surface layer parts were made to become the thermoplastic resin A. The thickness of each layer is adjusted by the gap between fine slits (formed at a processing accuracy of 0.01 mm) in the feed block and the discharge amount of each resin. The thermoplastic resin A layer has a thickness of 125 nm in the stretched and heat-treated film. The plastic resin B layer was designed to be 68 nm. Here, the thickness ratio of the adjacent A layer and B layer (A layer thickness / B layer thickness) was 1.98. The laminate composed of a total of 201 layers thus obtained was supplied to a T-die and formed into a sheet shape (draft ratio 10), and then applied with static electricity (DC voltage 8 kV) using a tape-like electrode. And rapidly solidified on a casting drum kept at a surface temperature of 25 ° C.

Both surfaces of the cast film thus obtained are subjected to corona discharge treatment in air, the wetting tension of the base film is set to 55 mN / m, and the treated surface is (polyester resin having a glass transition temperature of 18 ° C.) / (Glass transition temperature is A layer forming film coating solution composed of silica resin having an average particle diameter of 100 nm was applied to form a transparent, easy-sliding, and easy-adhesion layer. This cast film was guided to a tenter, preheated with hot air at 90 ° C., and then stretched 6.0 times in the width direction. The stretched uniaxially stretched film was directly heat-treated in a tenter with hot air of 235 ° C., subsequently subjected to a relaxation treatment of 5% in the width direction at the same temperature, and then cooled to room temperature and wound up. . In addition, a width direction scanning β-ray thickness meter and an instantaneous spectrometer that measures the reflection characteristics at 10 points in the width direction in-line are installed before winding, and the thickness distribution data and reflection obtained by measuring them are measured. Based on the data of the rate distribution, feedback was applied to the die lip gap adjustment. The resulting film had a thickness of 20 μm and was cut for a 2.25 m ² screen. The obtained results are shown in Table 1.

2. Production Example of G Reflector In Example 1, the film was produced under the same apparatus and conditions except that the film formation speed was adjusted and the film thickness was 16.5 μm. Moreover, the obtained film was cut for a 2.25 m ² screen. The obtained results are shown in Table 1.

3. Example of Manufacturing Method of B Reflector In Example 1, the film was formed under the same apparatus and conditions except that the film forming speed was adjusted and the film thickness was 14 μm. Moreover, the obtained film was cut for a 2.25 m ² screen. The obtained results are shown in Table 1.

4). Screen production example 1
The obtained B reflector, G reflector, R reflector and “Lumilar” X30, which is a black biaxially stretched PET film having a thickness of 188 μm, were bonded together with an acrylic adhesive. In addition, it bonded together so that it might become in order of B reflector, G reflector, R reflector, and X30 from the projection surface side. Further, a 19 μm mat film “Lumirror” X42 as a diffuser was bonded to the surface (projection surface side) of the B reflector with an acrylic adhesive. Furthermore, for reinforcement, it was bonded to a woven fabric to obtain a 2.25 m ² reflective screen. The obtained screen had high contrast, color purity and brightness even under bright light, and there was no color unevenness in the screen. Moreover, even if it wound up and stored repeatedly, neither a defect nor a bright spot due to breakage of the reflector occurred.

(Example 2)
1. BGR reflectors 201 layers are alternately laminated (B reflector) from the projection surface side with A layer 68 nm and B layer 72 nm, then 201 layers are alternately laminated (G reflector portion) with A layer 80 nm and B layer 84 nm, and further A film was formed under the same conditions and apparatus as in Example 1 except that a 603-layer feed block as shown in FIG. 4 was used so that 201 layers (R reflection portion) could alternately be formed by 97 nm of A layer and 102 nm of B layer. . However, the shape of the fine slit is (slot area on the non-feeding side of the thermoplastic resin) / (slit area on the supply side) is 40%, the slit length is 160 mm, and the pressure loss in the feed block is 3 MPa. The slit gap and discharge rate were designed. The draft ratio was 5. The results are shown in Table 1 for the obtained integrated BGR reflector. The thickness of the BGR reflector was 50.5 μm and was cut for a 2.25 m ² screen.

2. Screen production example 2
The obtained BGR reflector and “Lumilar” X30, which is a black biaxially stretched PET film having a thickness of 188 μm, were bonded together with an acrylic adhesive. In addition, it bonded together with X30 so that the projection surface side might become a B reflection layer. Further, a 19 μm mat film “Lumirror” X42 serving as a diffuser was bonded to the surface (projection surface side) of the B reflection layer with an acrylic adhesive. Furthermore, for reinforcement, it was bonded to a woven fabric to obtain a 2.25 m ² reflective screen. In this case, since the number of times of bonding was reduced, defects due to air entrainment during bonding and poor flatness were less likely to occur, and scattering by the adhesive layer was suppressed, resulting in higher definition than in Example 1. The obtained screen had high contrast, color purity and brightness even under bright light, and there was no color unevenness in the screen. Moreover, even if it wound up and stored repeatedly, neither a defect nor a bright spot due to breakage of the reflector occurred.

(Example 3)
1. Example of manufacturing R reflector, G reflector, and B reflector In Example 1, the apparatus and conditions were the same as in Example 1 except that the widthwise draw ratio was 5.0 times and heat treatment was performed at 200 ° C. It was. The obtained results are shown in Table 1.

2. Screen production example 3
A screen was prepared in the same manner as in Example 1 using the R reflector, G reflector, and B reflector obtained in Example 3. Although the obtained screen had high contrast and color purity under bright light, the luminance was slightly low, but it was in the range where there was no problem. Moreover, even if it wound up and stored repeatedly, neither the fault nor the bright spot by damage to a reflector generate | occur | produced.

Example 4
1. Production Example of R Reflector, G Reflector, and B Reflector In Example 1, in a feed block having 51 fine slits, a thickness composed of 26 layers of thermoplastic resin A and 25 layers of thermoplastic resin B A film was formed under the same conditions and apparatus as in Example 1 except that the structure was alternately laminated in the direction. Table 1 shows the results of the obtained RGB reflector. 2. Screen production example 4
A screen was prepared in the same manner as in Example 1 using the R reflector, G reflector, and B reflector obtained in Example 4. Compared with the screen of Screen Production Example 1, the contrast and color purity under bright light were slightly lower, but they were within the range of no problem. Moreover, even if it wound up and stored repeatedly, neither the fault nor the bright spot by damage to a reflector generate | occur | produced.

(Example 5)
1. Example of production of R reflector, G reflector, and B reflector In Example 1, the obtained cast film was heated with a roll group set at 90 ° C., and stretched 2.1 times in the longitudinal direction, and then this uniaxial stretching. Both surfaces of the film are subjected to corona discharge treatment in the air, the wetting tension of the base film is 55 mN / m, and the treated surface is (polyester resin having a glass transition temperature of 18 ° C.) / (Polyester resin having a glass transition temperature of 82 ° C.) ) / A laminate-forming film coating solution composed of silica particles having an average particle diameter of 100 nm was applied to form a transparent, easy-sliding, and easy-adhesion layer. This uniaxially stretched film was guided to a tenter, preheated with hot air at 100 ° C., and then stretched 5.0 times in the width direction. The stretched film was directly heat treated in a tenter with hot air at 230 ° C., then subjected to a relaxation treatment of 5% in the width direction at the same temperature, and then cooled to room temperature and wound up. The rest is the same as in Example 1. Table 2 shows the results of the obtained RGB reflector.

2. Screen production example 5
A screen was produced in the same manner as in Example 1 using the R reflector, G reflector, and B reflector obtained in Example 5. The obtained screen had a slightly low contrast and color purity, but was in a range where there was no problem. Moreover, even if it wound up and stored repeatedly, neither the fault nor the bright spot by damage to a reflector generate | occur | produced.

(Example 6)
1. Example of Manufacturing R Reflector, G Reflector, and B Reflector In Example 1, the draft ratio was set to 19, and the reflectance distribution data was not fed back by the instantaneous spectrometer. The obtained results are shown in Table 2.

2. Screen production example 6
A screen was prepared in the same manner as in Example 1 using the R reflector, G reflector, and B reflector obtained in Example 6. Since the thickness unevenness of the reflector is somewhat large, air tends to be engulfed when the screens are pasted together as compared with Example 1, and the handling property is slightly deteriorated. On the other hand, color irregularities with a slight periodicity were also observed, but the contrast and color purity under bright light were high, and no defects or bright spots due to damage to the reflector occurred even after repeated winding and storage. .

(Example 7)
1. Example of production of R reflector, G reflector and B reflector In Example 1, as thermoplastic resin B, a copolymer having an intrinsic viscosity of 0.95 obtained by copolymerizing 20 mol% of adipic acid and 10 mol% of isophthalic acid with respect to terephthalic acid. The conditions were the same as in Example 1 except that polymerized polyester was used. The obtained results are shown in Table 2.

2. Screen production example 7
A screen was prepared in the same manner as in Example 1 using the R reflector, G reflector, and B reflector obtained in Example 7. The obtained screen had higher contrast and color purity and higher brightness under bright light than Example 1. Moreover, even if it wound up and stored repeatedly, neither the fault nor the bright spot by damage to a reflector generate | occur | produced.

(Example 8)
1. Example of production of R reflector, G reflector, and B reflector In Example 1, the apparatus and conditions were the same as in Example 1 except that the widthwise draw ratio was 6 times and heat treatment was performed at 230 ° C. . The obtained results are shown in Table 3.

2. Screen production example 8
A screen was prepared in the same manner as in Example 1 using the R reflector, G reflector, and B reflector obtained in Example 8. Although the obtained screen is slightly inferior in contrast and color purity to the screen of Example 1, it is in a problem-free range, and even if it is repeatedly wound and stored, defects and bright spots due to damage to the reflector are not found. Did not occur.

Example 9
1. Example of manufacturing R reflector, G reflector, and B reflector In Example 1, the apparatus and conditions were the same as in Example 1 except that the widthwise draw ratio was set to 4 and heat treatment was performed at 230 ° C. . The obtained results are shown in Table 3.

2. Screen production example 9
A screen was prepared in the same manner as in Example 1 using the R reflector, G reflector, and B reflector obtained in Example 9. Although the obtained screen is slightly inferior in contrast and color purity to the screen of Example 8, there are no problems, and even if it is repeatedly wound and stored, defects and bright spots due to damage to the reflector are not found. Did not occur.

(Example 10)
1. Example of manufacturing R reflector, G reflector, and B reflector When forming a G reflector, in Example 1, except that the polymer flow rate from the laminating device to the die was slowed by 10% or more, Example 1 and The same apparatus and conditions were used.

2. Screen production example 10
A screen was prepared in the same manner as in Example 1 using the R reflector, G reflector, and B reflector obtained in Example 10. The obtained screen did not show a decrease in contrast due to light from a fluorescent lamp, and had high contrast, high color purity, and high brightness. Moreover, even if it wound up and stored repeatedly, neither the fault nor the bright spot by damage to a reflector generate | occur | produced.

(Example 11)
1. Example of manufacturing R reflector, G reflector, and B reflector In Example 1, after laminating by a feed block, when supplying to the die, the flow path is 1.1 to 2 times in the thickness direction at the die position opening. The apparatus and conditions were the same as in Example 1 except that the thickness of the reflector layer was designed to be thin. When the reflectance of the obtained R reflector, G reflector, and B reflector was measured with a spectrophotometer, the reflected wavelength tailed to the low wavelength side as shown in the reflectance distribution diagram of FIG. For comparison, FIG. 9 shows a reflectance distribution diagram in the case of the first embodiment.

2. Screen production example 11
A screen was prepared in the same manner as in Example 1 using the R reflector, G reflector, and B reflector obtained in Example 11. The obtained screen is less likely to cause a decrease in contrast even when the incident angle of projection light from a projector or the like deviates from the vertical direction of the screen. Did not occur.

(Example 12)
1. Example of production of R reflector, G reflector, and B reflector The apparatus and conditions were the same as in Example 1.

2. Screen production example 12
In the B reflector obtained in Example 1, 0.001 wt% of TAP-2 (Yamada Chemical Co., Ltd.), which is a specific wavelength absorbing dye, was dissolved in acetone, and IR-G205 as a binder was added to methyl ethyl ketone in 0%. .15 wt% dissolved solution was mixed and applied using a metabar with a winding diameter (mil) of 10 μm. Thereafter, it was placed in a hot air oven at 90 ° C. for 30 seconds and dried. Thereafter, the B reflector having the specific wavelength absorber, the G reflector and the R reflector obtained in Example 1, and “Lumirror” X30, which is a black biaxially stretched PET film having a thickness of 188 μm, are acrylic. It bonded together with the adhesive. In addition, it bonded together so that it might become in order of B reflector which has an absorber from a projection surface side, G reflector, R reflector, and X30. At this time, the B reflector was bonded with the absorber coating surface facing the projection surface. Further, a 19 μm mat film “Lumirror” X42 serving as a diffuser was bonded to the surface (projection surface side) of the B reflector with an acrylic adhesive. Furthermore, for reinforcement, it was bonded to a woven fabric to obtain a 2.25 m ² reflective screen. The resulting screen absorbs extraneous external light under bright light, and thus has very high contrast, color purity, and brightness, and has no uneven color within the screen. Moreover, even if it rewinds and stores repeatedly, neither the fault nor the brightness | luminance by damage to a reflector generate | occur | produced.

(Comparative Example 1)
1. Production Example of R Reflector, G Reflector, and B Reflector In Example 5, the apparatus and conditions were the same as in Example 5 except that the film was stretched 3.4 times in the longitudinal direction and 3.7 times in the width direction. . The results obtained are shown in Table 5.

2. Screen production example 11
A screen was prepared in the same manner as in Example 1 using the R reflector, G reflector, and B reflector obtained in Comparative Example 1. Since the obtained screen reflects not only the polarized light beam 1 but also the polarized light beam 2, the contrast and the color purity are lowered.

(Comparative Example 2)
1. Production Examples of R Reflector, G Reflector, and B Reflector In Example 1, polyethylene terephthalate (CHDM copolymerized PET) obtained by copolymerizing 33 mol% of cyclohexanedimethanol with ethylene glycol as the thermoplastic resin B and an intrinsic viscosity of 0. The apparatus and conditions were the same as in Example 1 except that a low-viscosity resin obtained by kneading and alloying 67 polyethylene terephthalate at a weight ratio of 85:15 in a twin-screw extruder was used. The melt viscosity of this thermoplastic resin B was 1300 poise. The obtained results are shown in Table 1.

2. Screen production example 12
A screen was prepared in the same manner as in Example 1 using the R reflector, G reflector, and B reflector obtained in Comparative Example 2. Even though the obtained screen was repeatedly wound up and stored, although there were no defects or bright spots due to breakage of the reflector, the color was uneven and the contrast was low.

(Comparative Example 3)
1. Production Example of BGR Reflector-Absorber The following thin films were formed by sputtering on the surface of “Lumirror” X30, which is a black biaxially stretched PET film having a thickness of 250 μm.
High refractive index layer: ZnS (refractive index 2.4, thickness 611 nm, 4 layers)
Low refractive index layer: MgF ₂ (refractive index 1.4, thickness 1047 nm, 3 layers)
2. Screen production example 13
A 19 μm mat film “Lumirror” X42 serving as a diffuser was bonded to the BGR reflector-absorber prepared in Comparative Example 3 with an acrylic adhesive. Furthermore, for reinforcement, it was bonded to a woven fabric to obtain a 2.25 m ² reflective screen. The obtained screen had high contrast and color purity even under bright light, and there was no color unevenness in the screen. However, repeated winding and storage caused many defects and bright spots due to breakage of the reflector, and the image quality gradually deteriorated.

  The present invention is used for a screen reflector and a screen. More specifically, it is suitably used for a screen and a screen reflector that display an image by receiving light from a light source such as a liquid crystal projector and a slide projector.

It is a schematic diagram which shows the characteristic of this invention. It is the top view which looked at the suitable feed block for manufacturing the laminated | multilayer film of this invention from the Y direction. It is the front view and sectional drawing of the slit member which comprise the said lamination | stacking apparatus. It is the top view which looked at the foot block from the Y direction. It is the front view and sectional drawing of the slit member which comprise the said lamination | stacking apparatus. It is sectional drawing which shows the relationship between the internal structure of the said lamination | stacking apparatus, and the flow of resin. It is a figure explaining the confluence | merging apparatus part of the said feed block. 6 is a reflectance distribution diagram of a screen reflector of Example 1. FIG. It is a reflectance distribution map of the reflector for screens of Example 11.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Side plate 2 Thermoplastic resin A supply part 3 Slit part 3a, 3b Slit 4 Thermoplastic resin B Supply part 5 Side plate 6 Laminating apparatus 7 Inlet 8 Liquid reservoir part (and its bottom face)
9 Outlet of laminating apparatus 10 Ridge line at top of slit 11 Upper edge part of ridge line 12 Lower edge part of ridge line

13, 21 Side plate 14, 18 Thermoplastic resin A supply part 15, 17, 19, Slit part 15a, 15b Slit 16, 20 Thermoplastic resin B supply part 22 Laminating device 23, 25 Inlet 24, 26 Liquid reservoir (or Its bottom)
27 Ridge line at the top of the slit 28 Upper edge part of the ridge line 29 Lower edge part of the ridge line 30 Flow of resin 31 Outlet of laminating apparatus 32 Merge apparatus 33 to 35 Flow path of resin

Claims (14)

The maximum reflectance R1 with respect to the polarized light beam 1 made of a thermoplastic film having a lamination number of 50 or more and incident from a direction that forms an angle of 10 ° with an axis perpendicular to the film plane in any of the bands corresponding to RGB. Is 70% or more, and the maximum reflectance R2 with respect to the polarized light beam 2 whose polarization plane is the vertical direction of the polarized light beam 1 is 60% or less, and the difference between the maximum value and the minimum value of R1 is 20 within 1 m ² . % Or less of a reflector for a screen.   The absolute value | Y (MD) -Y (TD) | of the difference between the Young's modulus Y (MD) in the longitudinal direction and the Young's modulus (TD) in the width direction of the thermoplastic film is 1 GPa or more. 2. A reflector for a screen according to 1.   The screen reflector according to claim 1 or 2, wherein a difference (R1-R2) between R1 and R2 is 30% or more.   The number of laminated thermoplastic films is 150 or more, substantially does not include an adhesive layer and an adhesive layer, and has a maximum reflectance of 70% or more for polarized light 1 in all bands corresponding to RGB. The reflector for a screen according to any one of claims 1 to 3.   5. The screen reflector according to claim 1, wherein a half-value width of a reflection band corresponding to G is 10 nm or more narrower than a half-value width of reflection bands corresponding to R and B. 6.   6. The screen reflector according to claim 1, wherein the thickness unevenness in the longitudinal direction and / or the width direction is 5% or less.   The reflector for a screen according to any one of claims 1 to 6, wherein the reflection band is asymmetric with respect to a wavelength giving the maximum reflectance, and is tailed to a low wavelength side.   The screen reflector according to any one of claims 1 to 7, wherein the thermoplastic film includes a layer made of polyethylene terephthalate and a layer made of polyester copolymerized with cyclohexanedimethanol.   The screen reflector according to claim 1, wherein the total light transmittance at 400 nm or more and less than 700 nm is 50% or more.   The reflector for a screen according to claim 1, which has at least one absorption peak at 520 to 620 nm.   The screen containing the reflector for screens in any one of Claims 1-10, and an absorber.   The screen according to claim 11, comprising a diffuser and / or a lens body.   13. The screen according to claim 12, wherein the diffuser according to claim 12 is an anisotropic diffuser, the vertical diffusion angle FWHM is less than 45 °, and the horizontal diffusion angle FWHM is 45 ° or more.   The screen according to claim 11, wherein the absorber has a thickness of 100 μm to 250 μm.

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