JP2004038003A - Screen for projection and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screen for projection which not only makes it possible to obtain a clear image without being affected by projection environment, but also can improve the contrast of the image to obtain a sharp image, and to provide a manufacturing method for the same. <P>SOLUTION: A stray light absorbing layer 13 is formed on an optical thin film 12. This stray light absorbing layer 13 transmits light of the primary-color wavelength region and light in an invisible wavelength region, and absorbs stray light near the wavelength region of the primary-color light. Hence the light of the primary-color light wavelength region with a sharp spectrum falls on the optical thin film 12. The optical thin film 12 reflects only the light of the primary-color wavelength having the sharp spectrum, and light of other wavelength regions is absorbed by a substrate 11. Consequently, the contrast of an image formed on the screen 10 for projection is enhanced. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a projection screen for displaying an image by receiving light from a light source and a method for manufacturing the same, and more particularly, to a reflective projection screen and a method for 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 this image light is projected on a projection screen through an illumination optical system such as a lens.
[0003]
There are projector devices of this type that can display a color image. As a light source, white light including red (Red = R), green (Green = G), and blue (Blue = B), which are three primary colors of light, is used. A lamp that emits light 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 the liquid crystal panel according to the image signal. The modulated light flux is 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 emitting narrow band light of each of the three primary colors is used as a light source, and a diffraction grating type 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 luminous flux modulated in this manner is combined as color image light by a light combining unit, similarly to 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.
[0006]
However, unlike a self-luminous display or a rear projector device, a front type projector device using a reflection type projection screen cannot reduce the reflection of external light by using, for example, an ND filter. When the projection environment is bright, there is a problem that it is difficult to increase the contrast between light and dark on the projection screen.
[0007]
In order to solve such a problem, a projection screen 100 on which an optical thin film 112 having a function as a so-called bandpass filter is formed as shown in FIG. 7 has been proposed (Japanese Patent Application No. 2002-070799). . The projection screen 100 includes a substrate 111 having a function as a light absorbing layer, on which an optical thin film 112 is formed. The optical thin film 112 is a dielectric multilayer film having a high reflection characteristic for light in a specific wavelength band and a high transmission characteristic for at least visible wavelength light other than the specific wavelength light. Each film thickness of the dielectric multilayer film is designed by simulation based on a matrix method. On the optical thin film 112, a light diffusion layer 113 for scattering light in a specific wavelength band reflected by the optical thin film 112 is formed.
[0008]
In the projection screen 100 having such a configuration, of the light emitted from the projector device, light in a specific wavelength band is reflected by the optical thin film 112, and the reflected light is scattered by the light diffusion layer 113 to form an image. It is formed. On the other hand, of the light emitted from the projector device, light outside the specific wavelength band passes through the optical thin film 112 and is absorbed by the substrate 111. As described above, the projection screen 100 can enhance the contrast between light and dark by the optical thin film 112 functioning as a bandpass filter, so that a clear image can be obtained even in a bright projection environment.
[0009]
However, in the projection screen 100, light outside the specific wavelength band is slightly reflected by the optical thin film 112, and reflected light in a wavelength region other than the specific wavelength band is scattered by the light diffusion layer 113, so that light other than the specific wavelength band is emitted. In particular, since stray light in the wavelength region described above, particularly in the region near the specific wavelength band, is mixed into the image, the contrast is reduced, and a clear image cannot be obtained.
[0010]
The present invention has been made in view of such a problem, and an object thereof is to reduce the contrast of an image by preventing light other than a specific wavelength region, particularly stray light near a specific wavelength region from being mixed into an image. It is an object of the present invention to provide a projection screen capable of obtaining not only a clear image without being affected by a projection environment but also a clear image, and a method of manufacturing the same.
[0011]
[Means for Solving the Problems]
The projection screen according to the present invention is formed on the substrate and the substrate, and has a high reflection characteristic with respect to light in a specific wavelength region, and at least with respect to light in a visible wavelength region other than the wavelength region. An optical thin film having high transmission characteristics, and an optical functional layer formed on the optical thin film and having a function of improving the reflection characteristics of the optical thin film with respect to light in the wavelength region.
[0012]
The method of manufacturing a projection screen according to the present invention has a high reflection characteristic for light in a specific wavelength region on a substrate and a high transmission characteristic for light in a visible wavelength region other than the wavelength region. Forming an optical thin film having the function of improving the reflection characteristic of the optical thin film with respect to light in the wavelength region.
[0013]
In the projection screen or the method of manufacturing the same according to the present invention, an optical functional layer is formed on the optical thin film, and the optical functional layer improves the reflection characteristics of the optical thin film with respect to light in a specific wavelength range. Other light, particularly stray light in the vicinity of a specific wavelength region, is prevented from being reflected by the optical thin film, whereby an image is formed by light in a specific wavelength region having a sharp spectrum.
[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 substrate 11. On the substrate 11, an optical thin film 12 having a function as a so-called bandpass filter is formed. On this optical thin film 12, a stray light absorbing layer 13 is formed. The stray light absorbing layer 13 improves the function of the optical thin film 12 as a bandpass filter. This will be described later. On the stray light absorption layer 13, a light diffusion layer 14 and a protective film 15 are sequentially formed.
[0016]
The substrate 11 is made of, for example, a polymer material containing a black paint or the like. Examples of the polymer material include polycarbonate (PC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether sulfone (PES), and polyolefin (PO). Since the substrate 11 is black including a black paint, the substrate 11 has a function as a light absorbing layer for absorbing light transmitted through the optical thin film 12, thereby increasing the black level of the screen and increasing the contrast between light and dark. improves.
[0017]
The optical thin film 12 is formed by alternately laminating a high refractive index film 12H made of a dielectric material having a high refractive index and a low refractive index film 12L made of a dielectric material having a lower refractive index than the high refractive index film 12H. The thickness of each of the dielectric multilayer films is, for example, not less than 80 nm and not more than 200 nm. As the dielectric material of the high refractive index film 12H, for example, niobium pentoxide (Nb ₂ O ₅ ), titanium dioxide (TiO ₂ ) or tantalum pentoxide (Ta ₂ O ₅ ), and as the dielectric material of the low refractive index film 12L, For example, silicon dioxide (SiO ₂ ) or magnesium fluoride (MgF ₂ ) can be used.
[0018]
Each film thickness of the optical thin film 12 has, for example, a high reflection characteristic with respect to light in three primary color wavelength ranges composed of light in wavelength ranges of red, green, and blue by a simulation based on a matrix method, and the three primary color wavelength ranges. It is designed to have high transmission characteristics at least for light in the visible wavelength region other than the light wavelength region. Specifically, the optical thin film 12 has high reflection characteristics with respect to red light having a wavelength of about 630 nm, green light having a wavelength of about 540 nm, and blue light having a wavelength of about 460 nm. It has high transmission characteristics for light in the visible wavelength range other than (FIG. 2).
[0019]
The stray light absorbing layer 13 is composed of a high refractive index film 13H made of a dielectric material having a high refractive index and a low refractive index film 13L made of a dielectric material having a lower refractive index than the high refractive index film 13H alternately. It is a laminated dielectric multilayer film. According to a simulation based on the matrix method, each film thickness of the dielectric multilayer film has a high absorption characteristic with respect to stray light near the wavelength region of the three primary color wavelength regions, and has a high transmittance with respect to at least the three primary color wavelength region lights. Designed to have properties. Specifically, the stray light absorbing layer 13 is provided for at least red light having a wavelength of about 630 nm, green light having a wavelength of about 540 nm, and blue light having a wavelength of about 460 nm. It has a high absorption characteristic and a high transmission characteristic at least for light in the three primary color wavelength ranges (FIG. 3).
[0020]
The stray light absorbing layer 13 configured as described above absorbs stray light in the vicinity of the wavelength region of the three primary color wavelength ranges, and light transmitted through the stray light absorbing layer 13 and incident on the optical reflection film 12 is shown in FIG. As shown, the spectrum of the light in the three primary color wavelength ranges becomes sharp.
[0021]
The light diffusion layer 14 is formed by arranging a plurality of spherical beads having a diameter of, for example, about several μm to several mm at equal intervals, and these beads are made of a transparent material such as glass or a polymer material. The light diffused layer 14 scatters light in the three primary color wavelength ranges transmitted through the stray light absorption layer 13. As a result, the viewing angle increases and good viewing characteristics can be obtained. Note that the arrangement of the beads does not have to be at equal intervals. The protective film 15 is for protecting the optical thin film 12, the light absorbing layer 13, and the light diffusing layer 14.
[0022]
Next, a method of manufacturing the projection screen 10 having such a configuration will be described. First, a substrate 11 made of a polymer material containing a black paint is prepared. Next, the optical thin film 12 is formed on the substrate 11 by, for example, a sputtering method. The optical thin film 12 is a dielectric multilayer film, and the dielectric multilayer film is formed by alternately stacking a high refractive index film 12H and a low refractive index film 12L having a lower refractive index than the high refractive index film 12H. . According to a simulation based on the matrix method, each film thickness of the optical thin film 12 has a high reflection characteristic with respect to the light of the three primary color wavelength ranges, and at least the wavelength other than the wavelength range of the light of the three primary color ranges. It is designed to have high transmission characteristics for light in the visible wavelength range.
[0023]
Subsequently, the stray light absorption layer 13 is formed on the optical thin film 12 by, for example, a sputtering method. The stray light absorbing layer 13 is a dielectric multilayer film, and the dielectric multilayer film is formed by alternately stacking a high refractive index film 13H and a low refractive index film 13L having a lower refractive index than the high refractive index film 13H. And The film thickness of the stray light absorbing layer 13 is such that the stray light absorbing layer 13 has a high absorption characteristic for stray light in the vicinity of the wavelength region of the three primary color wavelength regions by a simulation based on the matrix method. It is designed to have high transmission characteristics for wavelength band light. Finally, the light diffusing layer 14 and the protective film 15 are sequentially formed on the stray light absorbing layer 13 to complete the projection screen 10 shown in FIG.
[0024]
Here, an outline of a simulation based on a matrix method used when designing the optical thin film 12 and the stray light absorption layer 13 will be described. In this simulation, for example, a dielectric multilayer film formed on a substrate is used as a model. In this model of the dielectric multilayer film, assuming that predetermined light is incident on the surface of the dielectric multilayer film from the light source at a certain angle, multiple reflection occurs at the boundary of each film of the dielectric multilayer film. The multiple reflected lights interfere with each other depending on the wavelength of the light source, the thickness of each film of the dielectric multilayer film, and the refractive index.
[0025]
The matrix method is applied to such a dielectric multilayer model. Specifically, using the wavelength of light, the thickness and refractive index of the substrate, the thickness and refractive index of each film of the dielectric multilayer film, the angle of incident light on the surface of the dielectric multilayer film, and the like as parameters, A matrix operation is performed so that optical laws such as Maxwell's equation and Snell's law satisfy the boundary conditions in each of the dielectric multilayer films. Thus, the optical characteristics such as the transmittance and the reflectance of the dielectric multilayer film for predetermined light are obtained, and the dielectric multilayer film can be designed.
[0026]
The projection screen 10 having such a configuration is used, for example, as a screen of a front type projector device 20. FIG. 5 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.
[0027]
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.
[0028]
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, and 22B, and in the GLV 24, these components are arranged so as to be incident on the ribbon rows 24R, 24G, and 24B for each color.
[0029]
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. These condensed three primary color wavelength region lights are spatially modulated by driving each ribbon row of the GLV 24 independently according to an image signal.
[0030]
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 combined 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.
[0031]
In the projection screen 10, external light passes through the protective film 15 and the light diffusion layer 14 and enters the stray light absorption layer 13 together with the three primary color wavelength regions projected from the projector device 20. Since the stray light absorbing layer 13 has optical characteristics as shown in FIG. 3, the stray light absorbing layer 13 absorbs stray light in the vicinity of the wavelength region of the three primary color wavelength bands, and also emits the three primary color wavelength bands and invisible wavelengths. The light in the area is transmitted. Thereby, the spectrum of the light in the three primary color wavelength ranges incident on the optical thin film 12 becomes sharp.
[0032]
The light in the three primary color wavelength ranges and the light in the invisible wavelength range transmitted through the stray light absorption layer 13 enter the optical thin film 12. Since the optical thin film 12 has the reflection characteristics as shown in FIG. 2, only the light of the three primary colors is reflected, and the other light is absorbed by the substrate 11. That is, the optical thin film 12 reflects only the light in the three primary color wavelength ranges having sharp spectra, so that the spectrum of light in other wavelength ranges is greatly reduced (FIG. 4). The light in the three primary color wavelength ranges reflected by the optical thin film 12 passes through the stray light absorption layer 13 and enters the light diffusion layer 14. The light diffusion layer 14 scatters the light of the three primary color wavelengths transmitted through the stray light absorption layer 13 to form an image on the front surface of the screen.
[0033]
As described above, even if external light is incident on the screen together with the three primary color wavelength bands projected from the projector device 20, reduction in image contrast and reflection of external light due to external light are prevented. A clear image is obtained. In particular, since the stray light absorbing layer 13 absorbs stray light in the vicinity of the wavelength region of the three primary color wavelength regions and enhances the reflection characteristics of the optical thin film 12 with respect to the three primary color wavelength region light, an image is formed by the three primary color wavelength region light having a sharp spectrum. Therefore, a clear and clear image can be obtained.
[0034]
As described above, in the present embodiment, the stray light absorbing layer 13 is formed on the optical thin film 12, and the stray light near the wavelength region of the three primary color wavelength regions is absorbed by the stray light absorbing layer 13. The spectrum of the light in the three primary color wavelength ranges incident on the surface becomes sharp. Only the light in the three primary color wavelength ranges having a sharp spectrum is reflected by the optical thin film 12, and an image is formed by the reflected light composed of only the three primary color wavelength ranges. Therefore, a clear image is obtained without being affected by the brightness of the projection environment. Not only can it be obtained, but clear images can also be obtained.
[0035]
(Modification)
In the above embodiment, the stray light absorbing layer 13 is formed on the optical thin film 12, but the light selection auxiliary layer 31 may be formed as shown in FIG. The light selection auxiliary layer 31 has dots in the respective colors of cyan (C), magenta (M), and yellow (Y), which are the three primary colors of subtractive color mixing, arranged in the in-plane direction. These dots are formed in a predetermined shape, size, density, and arrangement by, for example, a printing method using a dye material of a transmission dye. Specifically, the dots have a size of 10 μm to several mm, and are regularly arranged in the order of cyan, magenta, and yellow.
[0036]
The projection screen 30 provided with such a light selection auxiliary layer 31 is applied to the projector device 20 used in the above embodiment. When light of three primary colors (R, G, B) is irradiated from the projector device 20, green light and blue light are reflected in cyan dots and red light is transmitted in the light selection auxiliary layer 31, and magenta dots are reflected in the light selection auxiliary layer 31. The red light and the blue light are reflected and the green light is transmitted, and the yellow dot reflects the red light and the green light and transmits the blue light. At this time, the light in the wavelength region other than the light of the three primary colors is transmitted through the light selection auxiliary layer 31. In this manner, only the three primary color wavelength bands of light are selectively reflected in each of the areas corresponding to the dots of each color, so that stray light in the vicinity of the three primary color wavelength bands of light is particularly reduced by the optical thin film 12. Since the reflection is prevented, the spectrum of the light in the three primary color wavelength bands transmitted through the light selection auxiliary layer 31 becomes sharp.
[0037]
The light in the three primary color wavelength ranges and the other wavelength ranges having sharp spectra transmitted through the light selection auxiliary layer 31 is incident on the optical thin film 12. The optical thin film 12 reflects only the light in the three primary color wavelength ranges, and the other light is absorbed by the substrate 11. The three primary color wavelength regions reflected by the optical thin film 12 pass through the light selection auxiliary layer 31 and enter the light diffusion layer 14. In the light diffusion layer 14, the light of the three primary color wavelength ranges transmitted through the light selection auxiliary layer 31 is scattered, and an image is formed on the front surface of the screen.
[0038]
As described above, in the present modification, the light selection auxiliary layer 31 is formed on the optical thin film 12, and the light selection auxiliary layer 31 is formed such that dots of each of the three primary colors of subtractive color mixing, namely, cyan, magenta, and yellow are formed in the in-plane direction. Since the arrangement is arranged, only the three primary wavelength bands of light are selectively reflected in each of the regions corresponding to the dots of each color, thereby stray light in the vicinity of the wavelength region of the three primary wavelength bands of light. Is prevented from being reflected by the optical thin film 12. This sharpens the spectrum of the light of the three primary colors in the optical thin film 12. Since only the light in the three primary color wavelength ranges having a sharp spectrum is reflected by the optical thin film 12, an image is formed by the reflected light consisting only of the three primary color wavelength ranges of the light, so that the image is formed without being affected by the brightness of the projection environment. Not only can a clear image be obtained, but also a clear image can be obtained.
[0039]
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 stray light absorbing layer 13 is formed on the optical thin film 12, but the light selection auxiliary layer 31 used in the above modification is formed on or below the stray light absorbing layer 13. You may do so. Further, in the above-described embodiment, the substrate 11 is made black by absorbing a light other than the three primary color wavelength bands by including a black paint in the polymer material. However, for example, a black paint is separately provided on the back side of the substrate 11. A light absorbing layer may be formed, and the light absorbing layer may absorb light other than the light in the three primary color wavelength ranges.
[0040]
【The invention's effect】
As described above, according to the projection screen and the method of manufacturing the same of the present invention, an optical functional layer is formed on an optical thin film, and the optical functional layer improves the reflection characteristics of the optical thin film with respect to light in a specific wavelength region. As a result, light other than the specific wavelength region, in particular, stray light near the specific wavelength region is prevented from being reflected by the optical thin film, and even when the projection environment is bright, the spectrum of the light in the specific wavelength region is reduced. It becomes sharp, and an image can be formed with light in this wavelength region. Therefore, the contrast of the image is increased, and a clear image can be obtained without being affected by the projection environment, and a clear image can be obtained.
[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 optical characteristics of an optical thin film constituting the projection screen shown in FIG.
FIG. 3 shows optical characteristics of a stray light absorbing layer included in the projection screen shown in FIG.
FIG. 4 shows the optical characteristics of the projection screen shown in FIG.
5 is a schematic configuration diagram of a projector device using the projection screen shown in FIG.
FIG. 6 is a schematic configuration diagram of a modification of the projection screen.
FIG. 7 is a schematic configuration diagram of a comparative example of a projection screen.
[Explanation of symbols]
10, 30 ... Projection screen, 11 ... Substrate, 12 ... Optical thin film, 12H, 13H ... High refractive index film, 12L, 13L ... Low refractive index film, 13 ... Stray light Absorbing layer, 14 Light diffusion layer, 15 Protective film, 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 ... 2 volume hologram element, 26 ... Galvano mirror, 27 ... Projection lens, 31 ... Light selection auxiliary layer

Claims (28)

Board and
An optical thin film formed on the substrate and having high reflection characteristics for light in a specific wavelength region and having high transmission characteristics for light in at least a visible wavelength region other than the wavelength region.
A projection screen comprising: an optical functional layer formed on the optical thin film and having a function of improving a reflection characteristic of the optical thin film with respect to light in the wavelength region. 2. The stray light absorption layer according to claim 1, wherein the optical function layer has a high absorption characteristic with respect to stray light in the vicinity of the wavelength region, and at least a high transmission characteristic with respect to light in the wavelength region. The projection screen according to the above. The stray light absorbing layer is a dielectric multilayer film in which a high refractive index film having a high refractive index and a low refractive index film having a lower refractive index than the high refractive index film are alternately stacked. The projection screen according to claim 2. 4. The projection screen according to claim 3, wherein the thickness of each of the dielectric multilayer films is designed by simulation based on a matrix method. The projection screen according to claim 1, wherein the light functional layer is a light selection auxiliary layer in which dots of each color of cyan, magenta, and yellow are arranged in an in-plane direction. The optical thin film is a dielectric multilayer film in which a high refractive index film having a high refractive index and a low refractive index film having a lower refractive index than the high refractive index film are alternately laminated, and the dielectric multilayer film 2. The projection screen according to claim 1, wherein the thickness of each film is 80 nm or more and 200 nm or less. Projection screen according to claim 6, wherein the high refractive index film is characterized in that it consists of _Nb 2 _O 5, TiO ₂ or _Ta 2 _{O 5.} The projection screen according to claim 7, wherein the low refractive index film is characterized in that it consists of SiO ₂ or MgF _2. The projection screen according to claim 1, further comprising a light absorption layer that absorbs transmitted light transmitted through the optical thin film. The projection screen according to claim 9, wherein the light absorbing layer includes a black paint. The projection screen according to claim 10, wherein the substrate also serves as the light absorbing layer. The projection screen according to claim 11, wherein the substrate is made of a polymer material. The projection screen according to claim 12, wherein the polymer material is polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, or polyolefin. The projection screen according to claim 1, wherein the wavelength region includes a red light wavelength region, a green light wavelength region, and a blue light wavelength region. Forming an optical thin film having high reflection characteristics on light in a specific wavelength region on the substrate and having high transmission characteristics on light in at least a visible wavelength region other than the wavelength region,
Forming a light functional layer having a function of improving a reflection characteristic of the optical thin film with respect to light in the wavelength region on the optical thin film. The stray light absorption layer having a high absorption characteristic for stray light in the vicinity of the wavelength region and having at least a high transmission characteristic for light in the wavelength region. A method for producing the projection screen according to the above. The stray light absorption layer is a dielectric multilayer film in which a high refractive index film having a high refractive index and a low refractive index film having a lower refractive index than the high refractive index film are alternately laminated. A method for manufacturing a projection screen according to claim 16. 18. The method of manufacturing a projection screen according to claim 17, wherein the thickness of each of the dielectric multilayer films is designed by simulation based on a matrix method. 16. The method of manufacturing a projection screen according to claim 15, wherein the optical function layer is a light selection auxiliary layer in which dots of respective colors of cyan, magenta, and yellow are arranged in an in-plane direction. The optical thin film is a dielectric multilayer film in which a high refractive index film having a high refractive index and a low refractive index film having a lower refractive index than the high refractive index film are alternately laminated, and the dielectric multilayer film 16. The method of manufacturing a projection screen according to claim 15, wherein the thickness of each film is set to be 80 nm or more and 200 nm or less. Method of manufacturing a projection screen according to claim 20, wherein the forming the high refractive index film by _Nb 2 _O 5, TiO ₂ or _Ta 2 _{O 5.} Method of manufacturing a projection screen according to claim 21, wherein the forming the low-refractive index film by SiO ₂ or MgF _2. The method for manufacturing a projection screen according to claim 15, further comprising a step of forming a light absorbing layer that absorbs transmitted light transmitted through the optical thin film. The method for manufacturing a projection screen according to claim 23, wherein the light absorbing layer includes a black paint. The method of manufacturing a projection screen according to claim 24, wherein the substrate also functions as the light absorbing layer. The method for manufacturing a projection screen according to claim 25, wherein the substrate is formed of a polymer material. 27. The method of manufacturing a projection screen according to claim 26, wherein the polymer material is selected from the group consisting of polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone and polyolefin. The method according to claim 15, wherein the wavelength region includes a red light wavelength region, a green light wavelength region, and a blue light wavelength region.

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