JP2004101558A - Screen for projection and its manufacture method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screen for projection which provides a clear image without being affected by projection environment, has flexibility and is manufactured at reduced cost. <P>SOLUTION: An optical multilayer film 12 is formed by alternately layering a metallic film 12M<SB>P</SB>and a dielectric film 12D<SB>P</SB>on a transparent substrate 11 by using a sputtering method. The film 12 has high reflecting characteristic to light in three-primary-color wavelength regions and high absorbing characteristic to light other than the light in the three-primary-color wavelength regions. Thus, the white level and the black level of the image are enhanced. Then, the film thickness dependency of the reflectance change of the film 12 becomes small and the incident angle dependency of the reflectance change becomes small, whereby the wide angle of view is obtained. Manufacture margin becomes large, and labor and time are not required so much in a manufacturing process. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a projection screen that displays an image by receiving light from a light source and a method of manufacturing the same, and more particularly, to a reflective projection screen and a method of manufacturing the same.
[0002]
[Prior art]
2. Description of the Related Art In recent years, overhead projectors and slide projectors have been widely used as means by which presenters present materials in conferences and the like, and video projectors and moving image film projectors have become widespread in ordinary households. In these projector devices, light output from a light source is spatially modulated by a light valve (Light Valve) to be image light, and the image light is projected on a projection screen through an illumination optical system such as a lens. .
[0003]
Some of this type of projector device can display a color image, and emits white light including three primary colors, red (Red = R), green (Green = G), and blue (Blue = B), as a light source. A light-emitting lamp is used, and a transmissive liquid crystal panel is used as a light valve. In this projector device, white light emitted from a light source is separated into red, green, and blue light beams by an illumination optical system, and these light beams are converged on a predetermined optical path. These light beams are spatially modulated by a liquid crystal panel in accordance with an image signal, the modulated light beams are combined as color image light by a light combining unit, and the combined color image light is enlarged and projected on a projection screen by a projection lens. .
[0004]
Recently, as a projector device capable of displaying a color image, a narrow-band three-primary-color light source, for example, a laser oscillator that emits narrow-band light of each of the three primary colors is used as a light source, and a diffraction grating light valve (GLV: An apparatus using Grating Light Valve has been developed. In this projector device, the luminous flux of each color emitted from the laser oscillator is spatially modulated by the GLV according to the image signal. The light flux modulated in this manner is combined as color image light by a light combining unit in the same manner as in the above-described projector device, and the combined color image light is enlarged and projected on a projection screen by a projection lens.
[0005]
[Problems to be solved by the invention]
By the way, the projection screen used in the projector apparatus is of a transmission type in which projection light is emitted from the back side and viewed from the front side, and a reflection type in which projection light is emitted from the front side and the reflected light is viewed from the front side. Divided into In any method, it is desired to obtain a bright and high-contrast image in order to realize a screen with good visibility. In addition, in order to improve the storability, a projection screen using a polymer material as a substrate material and utilizing the flexibility of the polymer material is desired.
[0006]
However, a bright and high-contrast image is obtained, and a flexible projection screen has not been realized. For example, in the projection screen 100 as shown in FIG. 11, a projection 112A is formed on the surface of the transparent layer 112, and an opaque layer 113 made of black paint is formed on the side surface of the projection 112A. By devising the shape, the black level is lowered to increase the brightness and contrast (for example, see Patent Document 1). However, a lot of time and labor is required in the process of forming the protrusion 112A and the process of forming the opaque layer 113, so that the manufacturing cost is increased and the flexibility cannot be obtained.
[0007]
[Patent Document 1]
Japanese Patent No. 2889153 [0008]
The projection screen 200 as shown in FIG. 12 includes a substrate 211, on which a reflective layer 212, a light absorbing layer 213, and a diffusion layer 214 are sequentially formed. Reference 2). The projection screen 200 having such a configuration has flexibility as a whole because all layers have flexibility, but the light absorbing layer 213 is formed closer to the light incident surface than the reflective layer 212. Since most of the incident light is absorbed by the light absorbing layer 213, the white level is reduced, and there is a problem that sufficient brightness and contrast cannot be obtained.
[0009]
[Patent Document 2]
Japanese Patent No. 3103802
The present invention has been made in view of such a problem, and an object thereof is to be able to obtain a clear image without being affected by a projection environment, to obtain flexibility, and to improve productivity. It is an object of the present invention to provide a projection screen and a method of manufacturing the same.
[0011]
[Means for Solving the Problems]
A projection screen according to the present invention includes a substrate and a light selection formed on one surface of the substrate and having a reflection characteristic for light in a specific wavelength region and an absorption characteristic for light in a region other than the specific wavelength region. And a reflective layer.
[0012]
The method for manufacturing a projection screen according to the present invention uses a sputtering method, on a substrate, has a reflection characteristic for light in a specific wavelength region, and absorbs light for light outside the specific wavelength region. The method includes a step of forming a light selective reflection layer having characteristics.
[0013]
In the projection screen according to the present invention, the light selective reflection layer shows a reflection characteristic for light in a specific wavelength region, and shows an absorption characteristic for light in a region other than the specific wavelength region. An image with high contrast is obtained.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0015]
FIG. 1 shows a partial cross-sectional configuration of a projection screen 10 according to an embodiment of the present invention. The projection screen 10 is a so-called reflection type screen. The projection screen 10 includes a transparent substrate 11, on which an optical multilayer film 12 is formed as a light selective reflection layer. The optical multilayer film 12 has a high reflection characteristic with respect to light in a specific wavelength region, and has a high absorption characteristic with respect to light outside the specific wavelength region. This will be described later. A light diffusion layer 13 is formed on the optical multilayer film 12.
[0016]
The transparent substrate 11 is made of, for example, a polymer material, has a thickness of 188 μm, and has flexibility. Examples of the polymer material include polycarbonate (PC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether sulfone (PES), and polyolefin (PO).
[0017]
Optical multilayer film 12 is a metal film 12M _p and the dielectric film 12D _p are alternately stacked (Here, p is a positive number of 1 to n). That is, the metal film 12M ₁ , the dielectric film 12D ₁ , the metal film M ₂ , the dielectric film 12D ₂ ,..., The metal film 12M _n , and the dielectric film 12D _n are sequentially stacked. Metal film 12M _p is of niobium (Nb), aluminum (Al) or silver (Ag). For example, when Al is used as the metal film 12M _p, average reflectance is increased in the optical multilayer film 12, the upper limit of the average reflectance this Al is determined. On the other hand, when Nb is used as the metal film 12M _p, average reflectance becomes small in the optical multilayer film 12, the lower limit of the average reflectance The Nb is determined. The dielectric film 12D _p is niobium pentoxide _{(Nb 2 O} 5), titanium dioxide _(TiO 2), tantalum pentoxide _{(Ta 2 O} 5), aluminum oxide _(Al 2 _{O 3)} or silicon oxide (SiO ₂₎ Become.
[0018]
Each film thickness of the optical multilayer film 12 has, for example, a high reflection characteristic of, for example, a reflectance of 70% or more with respect to three primary color wavelength region lights composed of light of red, green and blue wavelength regions, and the three primary colors. For light in a wavelength range other than the wavelength range light, it is designed to have high absorption characteristics, for example, an absorptance of 80% or more. Here, as for each film thickness of the optical multilayer film 12, assuming that the thickness of each film is d, the refractive index of each film is n, and the wavelength of incident light incident on the optical multilayer film is λ, The optical thickness nd is designed to satisfy the expression shown in Expression 1 with respect to the wavelength λ of the incident light.
[0019]
(Equation 1)
nd = λ (α ± １ ／) (where α is a natural number)
[0020]
For example, the metal film 12M _{1 Nb,} Nb 2 _{O 5} in the dielectric film 12D _1, the metal film 12M ₂ Nb, the dielectric film 12D _{2 Nb 2 O 5} is used, the total number of layers in total It has four layers and is designed to have the optical characteristics as shown in FIG. That is, the optical multilayer film 12 has a high reflectance, for example, a reflectance of 70%, with respect to the three primary color wavelength bands of red light having a wavelength of 642 nm, green light having a wavelength of 532 nm, and blue light having a wavelength of 457 nm. It has a high absorptivity for light in a wavelength region other than the three primary color wavelength regions, for example, an absorptivity of 80% or more, and for example, 5 to 10% for light in all wavelength regions. It is designed to have transmittance. By thus designed, the thickness of each layer, the metal film 12M ₁ is 40 nm, the dielectric film 12D ₁ is 553 nm, the metal film 12M ₂ is 20 nm, the dielectric film 12D ₂ is a 553 nm.
[0021]
The optical multilayer film 12 having such a configuration has a high reflection characteristic with respect to light in the three primary color wavelength ranges and a high absorption characteristic with respect to light in wavelength regions other than the three primary color wavelength ranges. The level and black level are increased. Further, since the total number of optical multilayer films 12 is reduced and the film thickness is reduced, the optical multilayer film 12 has flexibility. The wavelength of each color light of the three primary color wavelength ranges is the wavelength of the laser light of each color emitted from the light source (laser oscillator 21) of the projector device 20 (FIG. 8) applied to the present embodiment.
[0022]
If the thicknesses of all the films are changed at the same ratio based on the thicknesses of the metal film 12M ₁ , the dielectric film 12D ₁ , the metal film 12M ₂ , and the dielectric film 12D ₂ at this time, the three primary color wavelength ranges are obtained. In the wavelength region of each color light, the reflectance changes as indicated by (1) to (3) shown in FIG. Further, when the incident angle with respect to the screen is changed, the reflectance changes as shown in FIG. 4 in (1) to (3) shown in FIG. Here, as a comparative example, the film thickness dependence of the reflectance change in the optical thin film of the projection screen proposed by the same applicant as Japanese Patent Application No. 2002-070799 in FIG. 4 to 6 show the incident angle dependence of the reflectance change together with 4 to 6 in FIG. This optical thin film is obtained by alternately laminating a high refractive index layer and a low refractive index layer having a lower refractive index than the high refractive index layer, and niobium pentoxide (Nb ₂ O) is used as the high refractive index layer. ₅ ) Silicon dioxide (SiO ₂ ) is used as the low refractive index layer.
[0023]
As shown in FIG. 3, when the thickness of the optical multilayer film 12 is changed, in the present embodiment, the dependency of the reflectance change on the film thickness is smaller than in the comparative example. Further, as shown in FIG. 4, when the incident angle with respect to the screen is changed, in this embodiment, the dependency of the change in reflectance on the incident angle is smaller than in the comparative example. Especially in this case, because Nb is used for the metal film 12M ₁ and the metal film 12M _2, the incident angle dependence of the reflectance change becomes small, wide viewing angle characteristics can be obtained.
[0024]
Further, for example, the metal film 12M ₁ Al, _Nb 2 _{O 5} in the dielectric film 12D _1, the metal film 12M ₂ Nb, the dielectric film 12D _{2 Nb 2 O 5} is used, the total number of layers Have a total of four layers, and are designed to have optical characteristics as shown in FIG. That is, the optical multilayer film 12 has a high reflectance, for example, 80%, for the three primary wavelength bands, and has a high absorptance, for example, an absorption for light in a wavelength region other than the three primary wavelength bands. It is designed to have an absorptance of 90% or more and to have a transmittance of, for example, approximately 0% for light in all wavelength regions. By thus was designed, and 50nm thickness of the metal film 12M _1, the thickness of the dielectric film 12D ₁ is 551 nm, the thickness of the metal film 12M ₂ is 15 nm, the thickness of the dielectric film 12D ₂ 551 nm Has become.
[0025]
The optical multilayer film 12 having such a configuration has a high reflection characteristic with respect to light in the three primary color wavelength ranges and a high absorption characteristic with respect to light in a wavelength region other than the three primary color wavelength ranges. And the black level is increased. Further, the optical multilayer film 12 is thin because the total number of layers is small, and therefore has flexibility.
[0026]
If the thicknesses of all the films are changed at the same ratio based on the thicknesses of the metal film 12M ₁ , the dielectric film 12D ₁ , the metal film 12M ₂ , and the dielectric film 12D ₂ at this time, the three primary color wavelength ranges are obtained. In the wavelength region of each color light, the reflectance changes as shown in (1) to (3) in FIG. Further, when the incident angle with respect to the screen is changed, the reflectance changes as shown in (1) to (3) in FIG. Here, as comparative examples, the film thickness dependence of the reflectance change in the optical thin film described above ((4) to (6) in FIG. 6) and the incident angle dependence of the reflectance change ((4) to (4) in FIG. 7). 6)) is also shown.
[0027]
As shown in FIG. 6, when the thickness of the optical multilayer film 12 is changed, in the present embodiment, the dependency of the reflectance change on the film thickness is smaller than in the comparative example. Further, as shown in FIG. 7, when the incident angle with respect to the screen is changed, in the present embodiment, the dependency of the change in reflectance on the incident angle is smaller than in the comparative example. Especially in this case, Al in the metal film 12M _1, since Nb is used for the metal film 12M _2, film thickness dependency of the reflectance change becomes smaller.
[0028]
Here, the material used for the metal film 12M _p is not limited to the above metal material, metal material uniform reflectance in the visible light wavelength region is desirable. The material used for the dielectric film 12D _p is the dielectric material is not limited, the dielectric film 12D _p half of the reflection peak in the wavelength region of each color light enough three primary-color wavelength range is greater refractive index of the Since the value width increases and the half value width of the reflection peak in the wavelength region of each color light tends to decrease as the refractive index decreases, it can be appropriately selected according to the required optical characteristics of the screen. .
[0029]
The light diffusion layer 13 is, for example, a film on which a microlens array (MLA) is formed, and has flexibility. The light diffusion layer 13 scatters the three primary color wavelength regions reflected by the optical multilayer film 12. As a result, the viewing angle increases and good viewing characteristics can be obtained. Note that the light diffusion layer 13 may be one in which a plurality of spherical beads having a diameter of, for example, about several μm to several mm are arranged at equal intervals. These beads are made of a transparent material such as glass or a polymer material. Further, the light diffusion layer 13 may be a layer in which fine metal particles such as silver (Ag) and copper (Cu) are dispersed in a predetermined medium.
[0030]
As described above, in the present embodiment, since the transparent substrate 11, the optical multilayer film 12, and the light diffusion layer 13 all constituting the screen have flexibility, the screen itself has flexibility.
[0031]
Next, a method of manufacturing the projection screen 10 having such a configuration will be described. First, the transparent substrate 11 made of the above-mentioned polymer material is prepared. Then, for example, by sputtering, on a transparent substrate 11, to form an optical multilayer film 12 and a metal film 12M _p and the dielectric film 12D _p are laminated alternately. As described above, each film thickness of the optical multilayer film 12 has a high reflection characteristic with respect to three primary color wavelength band lights composed of red, green and blue color wavelength regions, and the wavelength of the three primary color wavelength band light. It is designed to have high absorption characteristics for light outside the region.
[0032]
Optical multilayer film 12, specifically, the dielectric film 12D ₂ made of a metal film _12M 2, _Nb 2 _{O 5} formed of a metal film _12M 1, _Nb 2 _O consisting of ₅ dielectric film _12D 1, Nb consisting Nb a four-layer structure, the thickness of each layer, 40 nm metal film 12M _1, the dielectric film 12D ₁ 553 nm, 20 nm and the metal film 12M _2, and 553 nm of the dielectric film 12D _2. As a result, the optical multilayer film 12 has a high reflectance, for example, 70%, for the three primary color wavelength bands, and a high absorptivity, for example, for light in a wavelength region other than the three primary wavelength bands. It has an absorptivity of 80% or more, and has a transmissivity of, for example, 5 to 10% for light in all wavelength regions (FIG. 2).
[0033]
Also, the optical multilayer film 12, four layers of dielectric films 12D ₂ made of a metal film _12M 2, _Nb 2 _{O 5} formed of a metal film _12M 1, _Nb 2 _O consisting of ₅ dielectric film _12D 1, Nb made of Al the structure, 50 nm metal film 12M ₁ the thickness of each layer, the dielectric film 12D ₁ 551 nm, 15 nm and the metal film 12M _2, and 551 nm of the dielectric film 12D _2. As a result, the optical multilayer film 12 has a high reflectance, for example, 80% for the three primary wavelength bands, and a high absorptivity, for example, for light in a wavelength region other than the three primary wavelength bands. It has an absorptivity of 90% or more, and has a transmittance of, for example, approximately 0% for light in all wavelength regions (FIG. 5).
[0034]
Finally, the projection screen 10 shown in FIG. 1 is completed by bonding a light diffusion layer 13 which is a film on which a microlens array (MLA) is formed, for example, on the optical multilayer film 12.
[0035]
As described above, in the present embodiment, not only the black level of an image is improved by providing the transparent substrate 11 with a function as a light absorbing layer, but also the white level of an image is improved by forming the optical multilayer film 12. By increasing the contrast of the image, a clear image can be obtained, so that the surface shape of the screen is devised by forming projections or the like to increase the contrast of the image as in the conventional case. It becomes unnecessary. As a result, labor and time are reduced, thereby reducing the manufacturing cost.
[0036]
Further, in the present embodiment, by which the optical multilayer film 12 configured to alternately stacked and a metal film 12M _p and the dielectric film 12D _p, small thickness dependency of the reflectance as compared with Comparative Example In addition, since the dependency of the reflectance change on the incident angle is reduced, the manufacturing margin is increased, the manufacturing cost is further reduced, and the productivity is improved.
[0037]
The projection screen 10 having such a configuration is used, for example, as a screen of a front type projector device 20. FIG. 8 shows a schematic configuration of the projector device 20. The projector device 20 includes, as a light source, a laser oscillator 21 that emits three-primary-color narrow-band light having a wavelength region of each of the three primary colors. The laser oscillator 21 includes, for example, a laser oscillator 21R that emits red light with a wavelength of 642 nm, a laser oscillator 21G that emits green light with a wavelength of 532 nm, and a laser oscillator 21B that emits blue light with a wavelength of 457 nm. ing.
[0038]
In addition, the projector device 20 includes a collimator lens 22, a cylindrical lens 23, a GLV 24, a volume hologram element 25, and a galvanomirror as an illumination optical system for guiding the light emitted from the laser oscillator 21 to the projection screen 10 as image light. 26 and a projection lens 27. The collimator lens 22 includes a collimator lens 22R for red light, a collimator lens 22G for green light, and a collimator lens 22B for blue light. The GLV 24 includes a ribbon row 24R for red light, a ribbon row 24G for green light, and a ribbon row 24B for blue light. The volume hologram element 25 includes a first volume hologram element 25a and a second volume hologram element 25b.
[0039]
In the projector device 20, the red light emitted from the laser oscillator 21R, the green light emitted from the laser oscillator 21G, and the blue light emitted from the laser oscillator 21B are respectively transmitted to the collimator lens 22 by the collimator lens 22R for each color. , 22G, 22B, and GLV 24, these components are arranged so as to be incident on the ribbon rows 24R, 24G, 24B for the respective colors.
[0040]
In the projector device 20 having such a configuration, each of the red light, the green light, and the blue light emitted from the laser oscillator 21 becomes parallel light by transmitting through the collimator lens 22. The three primary color wavelength regions converted into parallel light by the collimator lens 22 are condensed on the GLV 24 by the action of the cylindrical lens 23. The collected three primary color wavelength band lights are spatially modulated by driving each ribbon row of the GLV 24 according to the image signal.
[0041]
The three primary color wavelength region lights modulated by the action of the GLV 24 are condensed on the volume hologram element 25 by the action of the cylindrical lens 23. In this volume hologram element 25, red light is diffracted by the first volume hologram element 25a, and blue light and red light are diffracted in the same direction by the second volume hologram element 25b. In the first volume hologram element 25a and the second volume hologram element 25b, the green light travels straight without being diffracted, passes through, and is emitted in the same direction as the red light. In this way, the light of each color of red light, green light and blue light is synthesized by the action of the volume hologram element 25 and emitted in the same direction. The three primary color wavelength bands emitted in the same direction are scanned in a predetermined direction by a galvanomirror 26 and projected on the front surface of the projection screen 10 via a projection lens 27.
[0042]
In the projection screen 10 of the present embodiment, external light passes through the light diffusion layer 13 and enters the optical multilayer film 12 together with the light of the three primary color wavelength ranges projected from the projector device 20. Since the optical multilayer film 12 has the reflection characteristics shown in FIG. 2 or FIG. 5, the optical multilayer film 12 reflects the light in the three primary color wavelength ranges and absorbs light other than the three primary color wavelength ranges. The three primary color wavelength regions reflected by the optical multilayer film 12 enter the light diffusion layer 13 and are scattered by the light diffusion layer 14 to form an image on the front surface of the screen. At this time, since the white level and the black level are increased by the optical multilayer film 12, an image having a high contrast between light and dark can be formed. Therefore, a clear image can be obtained without being affected by the projection environment.
[0043]
Further, since the configuration of the optical multilayer film 12 and a metal film 12M _p and the dielectric film 12D _p are alternately laminated, a good viewing characteristic can be obtained as compared with Comparative Example. For example, the optical multilayer film 12, Nb in the metal film 12M _{1, Nb} 2 _{O 5} to the dielectric film 12D _1, Nb in the metal film 12M _2, the _Nb 2 _{O 5} to the dielectric film 12D ₂ are used, the total number of layers Has a total of four layers, as shown in FIG. 3, the dependency of the reflectance change on the film thickness is smaller than in the comparative example, and as shown in FIG. Good visual field characteristics can be obtained by reducing the dependence of the reflectance change on the incident angle. Further, for example, the metal film 12M ₁ Al, _Nb 2 _{O 5} in the dielectric film 12D _1, the metal film 12M ₂ Nb, the dielectric film 12D _{2 Nb 2 O 5} is used, the total number of layers Has a total of four layers, as shown in FIG. 7, the film thickness dependence of the reflectance change is smaller than in the comparative example. In addition, as shown in FIG. 8, a wide viewing angle can be obtained by reducing the dependency of the reflectance change on the incident angle as compared with the comparative example. As a result, the visual field characteristics can be improved, and the screen can be enlarged.
[0044]
Furthermore, over the transparent substrate 11 as the polymer material, since the configuration of the optical multilayer film 12 optical multilayer film 12 and a metal film 12M _p and the dielectric film 12D _p are alternately stacked, the screen It becomes flexible, which makes it possible to improve the storage ability.
[0045]
Also, by forming the optical multilayer film 12, the white level and the black level of the image are improved, so that the contrast of the image is enhanced so that a clear image can be obtained. It is not necessary to devise the surface shape of the screen by forming projections or the like to increase the contrast of the screen. As a result, labor and time are not required, thereby making it possible to reduce the manufacturing cost. Further, since the optical multilayer film 12 has a structure obtained by alternately laminating the metal film 12M _p and the dielectric film 12D _p, decreases the film thickness dependency of the reflectance change as compared with the comparative example, also, the reflectance The incident angle dependence of the change is reduced. As a result, the manufacturing margin can be increased, and as a result, the manufacturing cost can be further reduced, and the productivity can be improved.
[0046]
As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the above embodiment, and various modifications are possible. For example, in the above embodiment, the transparent substrate 11 is used as the substrate. However, for example, as in the projection screen 20 shown in FIG. 9, a black substrate 31 made of a polymer material containing a black paint or the like is used. Alternatively, the substrate itself may have a function as a light absorbing layer. Further, a light absorbing layer 32 made of a black paint may be separately formed on the back surface of the transparent substrate 31, as in the projection screen 30 shown in FIG. 10, for example. Further, a transparent substrate 31 may be used as a substrate, and a black substrate may be separately provided on the back surface of the transparent substrate 31.
[0047]
It is also possible to form a dielectric film between the transparent substrate 11 and the metal film 12M _1. This dielectric film is made of, for example, niobium pentoxide (Nb ₂ O ₅ ), titanium dioxide (TiO ₂ ), tantalum pentoxide (Ta ₂ O ₅ ), aluminum oxide (Al ₂ O ₃ ), or silicon oxide (SiO ₂ ). To be.
[0048]
Further, in the above-described embodiment, the light diffusion layer 13 is formed on the optical multilayer film 12 and the light diffusion layer 13 scatters the light of the three primary color wavelengths reflected by the optical multilayer film 12. A light diffusing portion having a plurality of convex portions or a plurality of concave portions is formed on the surface of the substrate 11, and the light diffusing portion has the same shape as the convex portions or the concave portions, and has a shape corresponding to light of a specific wavelength region. The optical thin film 12 having high reflection characteristics and high absorption characteristics for light in at least the visible wavelength region other than the wavelength region may be formed.
[0049]
【The invention's effect】
As described above, according to the projection screen according to any one of the first to twelfth aspects, the projection screen has a reflection characteristic with respect to light in a specific wavelength region on a substrate, and has a property other than the specific wavelength region. Since the light selective reflection layer having the absorption characteristic is provided for the light, the white level and the black level of the image can be increased. Therefore, a clear image can be obtained without being affected by the projection environment.
[0050]
In particular, according to the projection screen of the third aspect, since the light selective reflection layer has a configuration in which metal films and dielectric films are alternately laminated, a wide viewing angle can be obtained. As a result, the visual field characteristics can be improved, and the screen can be enlarged.
[0051]
According to the projection screen of the eighth aspect, the substrate is made of a polymer material and the light selective reflection layer is formed by alternately laminating a metal film and a dielectric film, so that the screen is flexible. , So that it is possible to improve the storability.
[0052]
According to the projection screen manufacturing method of any one of claims 13 to 24, the white level and the black level of the image are improved by forming the light selective reflection layer. The contrast between the light and dark is increased to obtain a clear image, so that it is not necessary to devise the surface shape of the screen by forming projections or the like to increase the contrast between the light and dark of the image as in the related art. . As a result, labor and time are not required, thereby making it possible to reduce the manufacturing cost.
[0053]
In particular, according to the projection screen manufacturing method of the present invention, since the light selective reflection layer is formed by alternately laminating the metal film and the dielectric film, the dependency of the reflectance change on the film thickness is reduced. It is possible to increase the manufacturing margin by reducing the incident angle dependence of the change in reflectivity, thereby making it possible to further reduce the manufacturing cost and improve the productivity. Become.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a projection screen according to an embodiment of the present invention.
FIG. 2 shows the optical characteristics of an optical multilayer film of the projection screen shown in FIG.
FIG. 3 is a graph comparing the reflection characteristics of an optical multilayer film of the projection screen shown in FIG. 1 with the reflection characteristics of an optical thin film of a projection screen of a comparative example.
FIG. 4 is a graph comparing the reflection characteristics of the optical multilayer film of the projection screen shown in FIG. 1 with the reflection characteristics of the optical thin film of the projection screen of the comparative example.
FIG. 5 shows the optical characteristics of the optical multilayer film of the projection screen shown in FIG.
6 is a graph comparing the reflection characteristics of the optical multilayer film of the projection screen shown in FIG. 1 with the reflection characteristics of the optical thin film of the projection screen of the comparative example.
7 is a graph comparing the reflection characteristics of the optical multilayer film of the projection screen shown in FIG. 1 with the reflection characteristics of the optical thin film of the projection screen of the comparative example.
FIG. 8 is a schematic configuration diagram of a projector device using the projection screen shown in FIG.
FIG. 9 is a schematic configuration diagram of a modification of the projection screen.
FIG. 10 is a schematic configuration diagram of a modification of the projection screen.
FIG. 11 is a schematic configuration diagram of a conventional projection screen.
FIG. 12 is a schematic configuration diagram of a conventional projection screen.
[Explanation of symbols]
10, 20, 30 ... Projection screen, 11 ... Transparent substrate, 12 ... Optical multilayer film, 12M _p ... Metal film, 12D _p ... Dielectric film, 13 ... Light diffusion Layer, 20 Projector device, 21, 21R, 21G, 21B Laser oscillator, 22, 22R, 22G, 22B Collimator lens, 23 Cylindrical lens, 24 GLV, 24R, 24G, 24B ... Ribbon row, 25 ... Volume hologram element, 25a ... First volume hologram element, 25b ... Second volume hologram element, 26 ... Galvano mirror, 27 ...・ Projection lens, 31 ・ ・ ・ Black substrate, 32 ・ ・ ・ Light absorbing layer

Claims (24)

Board and
A light selective reflection layer formed on one surface of the substrate and having a reflection characteristic with respect to light in a specific wavelength region and having an absorption characteristic with respect to light other than the wavelength region. Projection screen. 2. The projection according to claim 1, wherein the light selective reflection layer has a reflectance of 70% or more for light in a specific wavelength region and an absorptivity of 80% or more for light other than the wavelength region. screen. 2. The projection screen according to claim 1, wherein the light selective reflection layer is an optical multilayer film in which metal films and dielectric films are alternately stacked. 4. The projection screen according to claim 3, wherein the metal film is made of Nb, Al, or Ag. The dielectric film is _{Nb 2 O 5, TiO 2,} Ta 2 O 5, Al 2 O 3 or projection screen according to claim 3, characterized in that of SiO _2. The light selective reflection layer, a first metal film made of Nb, the first dielectric film made of _Nb 2 _{O 5,} a second metal film made of Nb, the second dielectric film made of _Nb 2 _{O 5} are laminated in this order 4. The projection screen according to claim 3, wherein the projection screen has a configuration. The light selective reflection layer, a first metal film made of Al, a first dielectric film made of _Nb 2 _{O 5,} a second metal film made of Nb, the second dielectric film made of _Nb 2 _{O 5} are laminated in this order 4. The projection screen according to claim 3, wherein the projection screen has a configuration. The projection screen according to claim 1, wherein the substrate is made of a polymer material. The projection screen according to claim 8, wherein the polymer material is one of polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, and polyolefin. The projection screen according to claim 1, further comprising a light diffusion layer on a surface of the light selective reflection layer opposite to a surface adjacent to the substrate. The projection screen according to claim 1, further comprising a light diffusion portion having a plurality of convex portions or a plurality of concave portions on a surface of the substrate on which the light selective reflection layer is formed. 2. The projection screen according to claim 1, wherein the specific wavelength region includes each wavelength region of red light, green light, and blue light. Using a sputtering method, a step of forming a light selective reflection layer having a reflection characteristic on light in a specific wavelength region on a substrate and having an absorption characteristic on light outside the wavelength region is included. A method of manufacturing a projection screen. 14. The projection screen according to claim 13, wherein the light selective reflection layer has a reflectance of 70% or more for light in a specific wavelength region and an absorption of 80% or more for light other than the wavelength region. Manufacturing method. 14. The method for manufacturing a projection screen according to claim 13, wherein the light selective reflection layer is an optical multilayer film in which metal films and dielectric films are alternately laminated. The method according to claim 15, wherein the metal film is formed of Nb, Al, or Ag. The dielectric film _{Nb 2 O 5, TiO 2,} Ta 2 O 5, Al 2 O 3 or the method of manufacturing the projection screen according to claim 15, wherein the forming the SiO _2. The light selective reflection layer, is laminated first metal film made of Nb, the first dielectric film made of _Nb 2 _{O 5,} a second metal film made of Nb, the second dielectric film made of _Nb 2 _{O 5} in order The method for manufacturing a projection screen according to claim 15, wherein The light selective reflection layer, is laminated first metal film made of Al, a first dielectric film made of _Nb 2 _{O 5,} a second metal film made of Nb, the second dielectric film made of _Nb 2 _{O 5} in order The method for manufacturing a projection screen according to claim 15, wherein 14. The method according to claim 13, wherein the substrate is formed of a polymer material. 21. The method for manufacturing a projection screen according to claim 20, wherein the polymer material is selected from the group consisting of polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, and polyolefin. 14. The method according to claim 13, wherein a light diffusion layer is formed on the light selective reflection layer. 14. The method of manufacturing a projection screen according to claim 13, wherein a light diffusion portion having a plurality of convex portions or a plurality of concave portions is formed on a surface of the substrate. 14. The method of manufacturing a projection screen according to claim 13, wherein the specific wavelength region includes each wavelength region of red light, green light, and blue light.

Images