JP2015227971A - Video projection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video projection window that can project a video in which a projected video has high visibility without reducing visibility of a background image that is seen through a video projection structure.SOLUTION: There is provided a video projection structure having a transparent layer and a plurality of light scattering parts linearly formed inside the transparent layer, where the plurality of light scattering parts are arranged at a predetermined interval, and diffraction efficiency of a diffraction light beam with highest intensity, of light beams diffracted by the video projection structure, is 20% or less.

Description

  The present invention relates to a video projection structure.

  Usually, the screen that displays the image light projected from the projector in a viewable manner is intended to display the image light projected from the projector regardless of whether it is a reflective type or a transmissive type. (Back side) cannot be observed. In the transmissive screen, the image light projected from the back side is transmitted to the observer side (front side) so that the image is displayed, so that the light from the back side can be transmitted. However, in such a transmissive screen, for example, because the surface has irregularities, it is possible to transmit light, but there is a case where the state on the back side cannot be observed.

  That is, most of the transmission screens that have been put to practical use use a polarizing film, a Fresnel lens sheet, a lenticular lens sheet, etc. in order to achieve high brightness and high contrast. However, such a conventional transmission screen is expensive because it uses a polarizing film or a lens sheet, and it is almost impossible to see the opposite side of the screen.

  A transmissive screen that can see the other side of the screen is disclosed in Patent Document 1.

JP 2014-13369 A

  In the above-described Patent Document 1, since the background and the image of the object that can be seen through the window and the like appear to be multiple, the visibility of the background that appears through the window and the like becomes low.

  When an image is projected from a projection device onto a window or the like, the projected image that has been transmitted can be seen. When no image is projected from the projection device, the background that has been transmitted through the window or the like What can be seen is required.

  It is an object of the present invention to provide a video projection window structure with high visibility of a projected video without reducing the visibility of a background image seen through the video projection structure window. In addition, the present invention can obtain a video projection structure having high visibility of a projected video with high accuracy and low cost without reducing the visibility of a background image that can be seen through the video projection structure. Provided is a method for manufacturing an image projection structure.

  The video projection structure of the present invention is a video projection structure having a transparent layer and a plurality of light scattering portions formed linearly inside the transparent layer, wherein the plurality of light scattering portions are: The diffraction efficiency of the diffracted light having the highest intensity among the lights diffracted by the image projection structure is 20% or less.

  The image projection structure manufacturing method of the present invention includes a step of forming a resin material layer on a surface of a substrate, forming a plurality of grooves on the surface of the resin material layer, and curing the resin material. Forming a transparent layer, and filling the groove in the transparent layer with a material containing a resin and a light scattering material and curing to form a light scattering layer.

  According to the video projection structure of the present invention, the visibility of the background image seen through the video projection structure is high, and the projected video can be viewed with high visibility. According to the method of manufacturing a video projection structure of the present invention, a video projection structure with high visibility of a projected video can be accurately obtained without reducing the visibility of a background image that can be seen through the video projection structure. Good and can be obtained at low cost.

Structure diagram of video projection window in this embodiment (1) Structure diagram of video projection window in this embodiment (2) Characteristic diagram of video projection window in this embodiment Illustration of video projection window in this embodiment Structure of video projection window in this embodiment (3) Process drawing of manufacturing method of video projection window in the present embodiment

  Modes for carrying out the invention will be described below. In addition, about the same member etc., the same code | symbol is attached | subjected and description is abbreviate | omitted.

(Video projection window)
A video projection window that is a video projection structure in the present embodiment will be described with reference to FIG. In the image projection window 100 according to the present embodiment, a plurality of stripe-shaped light scattering portions 20 extending in a one-dimensional direction are formed in the transparent layer 30 so as to be substantially parallel to the main surface of the transparent layer 30. . In addition, it is preferable that the cross section perpendicular | vertical to the extending | stretching direction of the light-scattering part 20 of the light-scattering part 20 is shapes, such as a triangle, trapezoid, and a bell. A structure in which a plurality of light scattering portions 20 extending in a one-dimensional direction is formed in a stripe shape as described above may be referred to as a louver structure. Therefore, in the present embodiment, a plurality of light scattering portions 20 are linearly formed inside the transparent layer 30, and the plurality of light scattering portions 20 are arranged at a predetermined interval.

  In the present embodiment, the transparent layer 30 preferably has a transmittance of 50 to 100%. The transparent layer 30 is preferably a transparent resin layer. The transparent resin is preferably a photo-curing resin such as an acrylic resin or an epoxy resin, a thermosetting resin, or a thermoplastic resin. In order to maintain transparency, the yellow index of the transparent resin is preferably 10 or less, and more preferably 5 or less so that the function as a window is not impaired.

The thickness of the transparent layer 30 is preferably 10 to 200 μm.
When it is 10 μm or less, the pitch is also 10 μm or less, and the effect of the louver structure becomes difficult to be seen. Moreover, when it becomes 200 micrometers or more, the production by roll-to-roll becomes difficult in terms of thickness.

  The light scattering portion 20 is formed of a transparent resin containing a light scattering material, or a transparent resin containing a light scattering material and a light absorbing material. As the transparent resin used for the light scattering portion 20, a photo-curing resin such as an acrylic resin or an epoxy resin, a thermosetting resin, a thermoplastic resin, or the like can be used. The transparent resin used for the light scattering unit 20 may be the same as or different from the transparent resin used for the transparent layer 30.

  As light scattering material, fine particles of high refractive index material such as titanium oxide (refractive index: 2.5 to 2.7), zirconium oxide (refractive index: 2.4), aluminum oxide (refractive index: 1.76), etc. Fine particles of a low refractive index material such as porous silica (refractive index: 1.25 or lower), hollow silica (refractive index: 1.25 or lower), or the like; a resin material having a low refractive index compatible with the transparent resin; Alternatively, a crystallized resin material of 1 μm or less can be used.

  The concentration of the light scattering material contained in the light scattering portion 20 is preferably 0.01 vol% or more and 5 vol% or less, and more preferably 0.05 vol% or more and 1 vol% or less.

  When the light scattering material 20 is a fine particle, the size of the fine particle has a probability of being scattered forward when the central value of the distribution is the same as or slightly smaller than the wavelength of the scattered light, and the incident light is refracted. The function to scatter without strengthening. As a result, the distortion of the background image is suppressed and the amount of light is not changed abruptly, which has the effect of improving transparency. The size of the central value of the distribution is preferably 1 μm to 0.05 μm, and preferably 0.8 μm to 0.15 μm.

  As the light absorbing material, carbon black, titanium black, or the like can be used. The concentration of the light absorbing material contained in the light scattering portion 20 is preferably 0.01 vol% or more and 10 vol% or less, and more preferably 0.1 vol% or more and 3 vol% or less. The light scattering portion 20 preferably has an optical density at the maximum height of 0.05 to 2, and more preferably 0.1 to 1. In addition, by including a light absorbing material in the light scattering unit 20, it is possible to absorb a part of the light propagating as unnecessary stray light in the image projection window 100, and the scattered light is reduced. Therefore, it is possible to suppress the phenomenon of appearing cloudy in the video projection window 100, to improve the visibility by improving the contrast of the projected video, and to view the video with improved contrast in the background. Can be improved. In particular, when an environment of 100 lux or more is present in the observer's line of sight due to external light, the above effect can be easily obtained.

  The transparent layer 30 may be laminated with the transparent substrate 10. The transparent substrate 10 may be glass or a transparent resin, and is preferably a transparent resin. As glass which comprises the transparent base material 10, soda-lime glass and an alkali free glass are preferable. In order to improve durability, chemical strengthening, hard coating, or the like may be performed. As the transparent resin constituting the transparent substrate 10, a photo-curing resin such as an acrylic resin or an epoxy resin, a thermosetting resin, a thermoplastic resin, or the like can be used. The transparent resin constituting the transparent substrate 10 is preferably the same as the transparent resin constituting the transparent layer 30.

  The thickness of the transparent substrate 10 is preferably within 0.05 mm to 10 mm, and more preferably within 0.1 mm to 5 mm.

  In the video projection structure in the present embodiment, the difference between the refractive index of the transparent layer 30 and the refractive index of the light scattering portion 20 is preferably 0.01 or less, more preferably 0.005 or less, and 0.001 or less. Is more preferable. This is because if the difference between the refractive index of the transparent layer 30 and the refractive index of the light scattering portion 20 is large, the images seen through the image projection window appear to be multiple. In order to suppress rainbow unevenness and background splitting, periodic modulation of the refractive index and transmittance is prevented from occurring. The portions 20 preferably have the same refractive index.

  Moreover, it is preferable that the refractive index of the transparent base material 10 and the refractive index of the transparent layer 30 are as close as possible. Further, the difference between the refractive index of the transparent substrate 10 and the refractive index of the light scattering portion 20 is preferably 0.1 or less, more preferably 0.05 or less, further preferably 0.01 or less, and 0.001 or less. Particularly preferred. As will be described later, in the manufacturing process of the image projection structure, the transparent base material 10 has periodic unevenness due to polymerization shrinkage when the light scattering portion 20 is cured, so that it has the same refractive index. It may be a member intended to be embedded with a member. In addition, the polymerization shrinkage is often about 10%. Therefore, as the degree of influence that the refractive index shifts, the difference between the transparent substrate 10 and the transparent layer 30 is different from the difference between the transparent substrate 10 and the light scattering portion 20. May be in the range of about 10 times.

In the case where there is a louver structure as shown in FIG. 2, I ₀ shown in Equation 1, which is a number correlated with the amount of light transmitted through the light scattering portion 20 and the transparent layer 30 without being diffracted, is 0. It is preferably 6 or more, more preferably 0.7 or more, and further preferably 0.85 or more. In Equation 1, each symbol has the following meaning. θ = Δn × d / λ ( Δn: difference in refractive index between the transparent layer 30 and the light scattering portion 20, lambda: wavelength of incident light, d: the maximum height of the light scattering portion 20) is, K ₀ is transparent layer 30 is a difference in extinction coefficient between the light scattering unit 20 and the light scattering unit 20. When the length X0 of one period of the louver structure is 1, X1 is the length of the region where the light scattering portion 20 does not exist, and X2 and X4 are the length of the region where the light scattering portion 20 and the transparent layer 30 are mixed. X3 is an area of 90% or more of the maximum height of the light scattering portion 20.

本実施の形態における映像投影窓は、映像投影窓を透過した光のうち、映像投影窓において回折された最も強度の高い回折光の回折効率が、２０％以下となるように形成されており、１０％以下となるように形成されていることが好ましく、５％以下となるように形成されていることがより好ましい。回折効率は、透過する光の全光量に対して、測定したい次数の回折光のスポットを中心としたある範囲に含まれる光を測定することによって得られる。ある範囲とは、測定したい次数の１つ小さい次数との中間地点から、１つ大きい次数までの中間地点までの間の範囲である。

The image projection window in the present embodiment is formed so that the diffraction efficiency of the highest intensity diffracted light diffracted in the image projection window out of the light transmitted through the image projection window is 20% or less, It is preferably formed so as to be 10% or less, and more preferably formed so as to be 5% or less. The diffraction efficiency is obtained by measuring light included in a certain range centered on a spot of diffracted light of the order to be measured with respect to the total amount of transmitted light. The certain range is a range from an intermediate point with one order of the order to be measured to an intermediate point with an order of one higher.

  In the video projection window in the present embodiment, in order to prevent multiple images seen through the video projection window from being seen, light that is transmitted through the video projection window without being diffracted is transmitted. Is preferably formed so as to be 60% or more of the total transmitted light amount, more preferably formed so as to be 80% or more, and further preferably formed so as to be 90% or more. preferable. However, the light that is transmitted without being diffracted includes light that is scattered and spread.

  In addition, when the light scattering portion 20 includes a light absorbing material, the light absorbed by the light scattering portion 20 is preferably 80% or less of the light incident on the light scattering portion 20.

Note that the transmittance of visible light in the video projection window in this embodiment is preferably 40% or more and 90% or less, and more preferably 50% or more. In order to improve the contrast, an absorbing material having a haze of 5 or less may be laminated and disposed on the outside of the transparent substrate 10 or the outside of the transparent layer 30. In that case, the value of transmittance of the image projection window / (1-transmittance of the absorbing material) is 40% or more, 90% or more, and preferably 50% or more.

Moreover, in this Embodiment, it is preferable to satisfy | fill the formula shown by following (1).

(Average thickness of light scattering portion 20) × (Concentration of light scattering material in light scattering portion 20) / (Particle diameter of light scattering material) ≦ 1400 (1)

For example, the cross section of the light scattering portion 20 is formed in a triangular shape, the thickness d in the light scattering portion 20 is 80 μm, the concentration of the light scattering material in the light scattering portion 20 is 5%, and the fine particle diameter of the light scattering material is 0.25 μm. In this case, the average thickness in the light scattering portion 20 is 40 μm, and the value of (average thickness of the light scattering portion 20) × (concentration of light scattering material in the light scattering portion 20) / (fine particle diameter of the light scattering material) is 800. Further, when it is considered to be 0.15 μm or more which is a preferable fine particle diameter range, (average thickness of light scattering portion 20) × (concentration of light scattering material in light scattering portion 20) / (fine particle diameter of light scattering material) Since the value is a little over 1300, the value is preferably 1400 or less, and preferably satisfies (1). Therefore, in order to increase the visibility of the image projected in the video projection window and to increase the visibility of the background that can be seen through the video projection window, the expression shown in the above (1) must be satisfied. preferable. The background that can be seen through the video projection window is an image of an object that the viewer sees through the video projection window when the video projection window is installed between the viewer and the thing. That is, it is an image of a background or an object that can be seen through the image projection window.

When the width of the light scattering portion 20 is A and the width of the region where the light scattering portion 20 is not formed, that is, the width of the region between the light scattering portion 20 and the light scattering portion 20 is B, It is preferable that the formula shown in (2) is satisfied. Incidentally, _{T A} is the average transmittance in the light scattering portion 20.

_{(T A × A) / (} A + B) + B / (A + B) ≧ 0.6 ···· (2)

Further, in the case of A: B = 1: 1, when the difference in refractive index between the light scattering portion 20 and the transparent layer 30 is Δn and the wavelength is λ, the thickness d of the light scattering portion 20 is 70% of the thickness d. The relationship between the transmittance and Δnd / λ is preferably a region indicated by satin hatching in FIG.

  Note that the video projection window 100 in the present embodiment is a transmissive video projection window. That is, as shown in FIG. 4, an image is projected from the projector 110 onto the image projection window 100, and an image seen through the image projection window 100 is on the side opposite to the side where the projector 110 is installed. It is for the observer to see.

  Note that the image projection window in the present embodiment has a visible light transmittance of 40% or more and 90% or less, a front haze of 0 or more and 40 or less, and a rear haze of 5 or more and 50 or less. In addition, it is preferable that the intensity of the backscattered light when the light is incident at an angle of 45 ° with respect to the surface of the image projection window is lower than the intensity of the forward scattered light. The forward haze is a percentage of transmitted light that deviates by 2.5 ° or more from incident light. The back haze is a percentage of the reflected light that is deviated by 2.5 ° or more from the regular reflected light.

  Next, a method for manufacturing a video projection window in the present embodiment will be described. Specifically, a manufacturing method of the video projection window having the structure shown in FIG. 5 which is a kind of video projection window in the present embodiment will be described.

  The image projection window having the structure shown in FIG. 5 is laminated glass, and a transparent resin film 40 is pasted on the transparent layer 30 in the image transparent window having the structure shown in FIG. A first glass substrate 61 is attached to the transparent resin film 40 with an adhesive layer 51, and a second glass substrate 62 is attached to the transparent base material 10 with an adhesive layer 52.

  A method of manufacturing the image projection window in the present embodiment shown in FIG. 5 will be described with reference to FIG.

  First, as shown in FIG. 6A, the transparent layer 30 is formed on the transparent resin film 40. Specifically, a photocurable resin is applied to the surface of the transparent resin film 40 by spin coating, die coating, inkjet coating, spray coating, or the like, and the mold 90 is pressed onto the applied photocurable resin. By irradiating ultraviolet rays, the photocurable resin is cured to form the transparent layer 30 which is a transparent resin layer. Thereafter, the mold 90 is peeled off from the transparent layer 30. Thereby, the transparent layer 30 which has the groove | channel 30a of the shape corresponding to the shape of the light-scattering part 20 on the surface is formed. The mold 90 may be formed of a resin mold, and is provided with a protrusion 90a having a shape corresponding to the shape of the light scattering portion 20 to be formed later. The molding die 90 is pressed so that the surface on which the protrusions 90 a are provided is on the coated photocurable resin, and grooves 30 a corresponding to the shape of the protrusions 90 a are formed on the surface of the transparent layer 30. To be. In addition, you may form the transparent layer 30 with a thermosetting resin.

  Thereby, the groove | channel 30a for forming the light-scattering part 20 which is a louver structure can be formed in the surface of the transparent layer 30. FIG.

  The pitch of the grooves 30a is preferably small enough to be invisible, preferably 250 μm or less, and more preferably 100 μm or less. Further, from the viewpoint of manufacturing, it is easy to manufacture if it is large to some extent, and specifically, it is preferable to be 10 μm or more. The width of the groove 30a is preferably narrower for the purpose of improving the transmittance and the visibility of the background, preferably 70% or less of the pitch, and preferably 50% or less. From the viewpoint of manufacturing, the pitch is preferably 10% or more of the pitch, and more preferably 25% or more. Regarding the depth, the aspect ratio is preferably higher than the width of the groove 30a, preferably 1 or more, preferably 1.5 or more, and more preferably 2 or more. Regarding the length, from the viewpoint of production, it is preferable that the length in the groove direction is as long as that of the film so that a one-dimensional groove structure is obtained, since this is suitable for low cost. In addition, it is preferable that a pillar structure having the same width and length of the groove 30a is less likely to generate projection angle dependency even when the projector that projects the screen is close to the screen.

  Next, as shown in FIG. 6B, the light scattering portion 20 is formed in the groove 30 a of the transparent layer 30. Specifically, for example, a paste containing a photocurable resin for forming the light scattering portion 20 is supplied to the groove 30a of the transparent layer 30, and the excess is scraped off with a doctor blade. Thereby, the paste is embedded in the groove 30 a of the transparent layer 30. Then, the light-scattering part 20 is formed in the groove | channel 30a of the transparent layer 30 by irradiating an ultraviolet-ray and hardening a paste. In this manner, the light scattering portion 20 having a louver structure is formed. In addition, you may form the light-scattering part 20 using a thermosetting resin.

  In the present embodiment, the paste for forming the light scattering portion 20 is obtained by mixing the light diffusing material with the photocurable resin used when forming the transparent layer 30 so as to have a desired concentration. Is formed.

  Next, as shown in FIG. 6C, a photocurable resin that forms the transparent substrate 10 is applied on the transparent layer 30 and the light scattering portion 20. Thereby, when the unevenness | corrugation has arisen when forming the light-scattering part 20, the surface can be planarized. Specifically, after applying the photocurable resin used when forming the transparent layer 30 on the transparent layer 30 and the light scattering portion 20, a transparent substrate (non-conductive) is applied on the applied photocurable resin. (Shown) is placed, irradiated with ultraviolet rays, and then the transparent substrate is peeled off. Thereby, the transparent substrate 10 is formed on the transparent layer 30 and the light scattering portion 20. Note that the transparent substrate 10 is preferably formed of the same material as the transparent layer 30.

  Next, as shown in FIG. 5, the image projection window is laminated and vitrified. Specifically, a first vinyl substrate 61 and a second glass substrate 62 and PVB (Poly vinyl butyral) films to be the adhesive layers 51 and 52 are prepared. Thereafter, a PVB film to be the adhesive layer 51 and the first glass substrate 61 are sequentially laminated on the transparent resin film 40, and a PVB film to be the adhesive layer 52 and the second glass are laminated on the transparent substrate 10. The substrates 62 are stacked in order. After that, by performing vacuum thermocompression bonding, an image projection window having a structure shown in FIG. 5 can be manufactured which becomes a laminated glass having a light scattering louver inside.

  The adhesive layers 51 and 52 are for bonding the first glass substrate 61 and the second glass substrate 62, and are made of, for example, a thermoplastic resin composition mainly composed of a thermoplastic resin. is there. Although the thickness of the adhesive layers 51 and 52 is not necessarily limited, for example, 0.025 to 1.0 mm is preferable, and 0.05 to 0.5 mm is more preferable.

  Examples of the thermoplastic resin used for the adhesive layers 51 and 52 include thermoplastic resins conventionally used for this type of application. For example, plasticized polyvinyl acetal resin, plasticized polyvinyl chloride resin, saturated polyester resin, plasticized saturated polyester resin, polyurethane resin, plasticized polyurethane resin, ethylene-vinyl acetate copolymer resin, ethylene- Examples include ethyl acrylate copolymer resins.

Next, the use of the video projection structure in the present embodiment will be described.
The following uses are mentioned as a window etc. in structures, such as a building.
・ Display of interiors, CMs and educational images in living spaces ・ Display of advertisements by projection from inside the building ・ Display of information and advertisements at car dealers ・ Triangle windows and tooth-killing windows of buildings Changes in the design of advertisements, movies, and exteriors, especially display on the top of windows, supermarkets, displays used for glass doors in retail and public buildings, information displays, events, etc., greenhouses (green houses), etc.・ Growth information etc. as a structural material in the building ・ Use as a glass wall that can change the pattern of wallpaper ・ Partition of a bathroom in a stadium, studio, hotel, etc. ・ Project and unproject appropriate images and light Use as a switchable privacy screen. In particular, in a conference room, hospital, bank, restaurant, or public facility, when the light is not projected, it can be clearly seen, so that security can be improved when the privacy filter is not used.
・ Display of characters, signs, images, and videos at airports, stations, hospitals, and schools ・ Display of regional and tourism information at religious institutions such as temples, shrines, shrines, churches, etc. ・ Space production at commercial facilities ・ Projection mapping ・Display of characters, signs, images and videos in the stadium ・ Projection of information in the kitchen and video for individuals ・ Use as a member that can be written and displayed in schools and meeting rooms. Also used with user interface.
・ Used as a pair of insulated glass, refrigerator doors at supermarkets and convenience stores.

The following uses are mentioned as a use in a table top, a casing, or the like.
・ Restaurant table top ・ Sushi restaurant counter ・ Desktop (desktop), kitchen counter ・ Tabletop partition ・ Department store basement ・ Boutique showcase ・ Change room ・ Vending machine ・ Pachinko parquet ・ Pachinko stand front glass. When you are playing a pachinko, it is transparent so you can hit it as you normally. When the table is empty and no one is sitting, it is used to advertise the store on the front glass.

Moreover, the following uses are mentioned as a use in a vehicle.
In rail cars,
・ Window glass on the back of the driver's seat (prevents reflection of interior lighting when driving underground)
・ Information display on railway side window glass ・ Suspended in advertisement ・ Partition part of Shinkansen ・ Glass function for window glass for linear motor car ・ Window for train In particular, the visibility is improved when used after sunset.
In automobiles,
・ Display on the shade part of the windshield ・ Information display on the lower part of the windshield for automobiles ・ Information on the taxi and limousine in the car partition, advertisement in the video display bus (the back of the driver)
-In car sun visors, minivans, SUVs, TV and DVD images are displayed as in-car partitions. ] Is displayed.
-Mounted on rear glass, backlight, HMSL, information display on the back, destination display of buses, etc.-Meter surroundings-Screen for door glass Anti-glare glass, anti-glare to use the diffuse function of reflected light and transmitted light A mirror is mentioned. Other special applications include traffic light cover glass (integration of various signal displays) and the like.

  Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.

(Example 1)
As the transparent resin film 40, a transparent polyethylene terephthalate (PET) film (refractive index: 1.58) having a thickness of 50 μm was prepared. The refractive index is a value measured at room temperature using d-line (wavelength 589 nm) of a sodium lamp. As an ultraviolet curable resin, Hitaroid 7981 (manufactured by Hitachi Chemical Co., Ltd., specific gravity 1.1) was prepared. An ultraviolet curable resin was applied to the surface of the transparent resin film 40 by spin coating.

  A mold 90 in which a plurality of protrusions 90a are arranged in a stripe shape on a flat surface was prepared. The mold 90 was pressed onto the applied ultraviolet curable resin at a temperature of 25 ° C. and a gauge pressure of 0.5 MPa. By irradiating with ultraviolet rays, the photocurable resin was cured to form the transparent layer 30. Thereafter, the mold 90 was peeled off from the transparent layer 30.

  Thereby, on the surface of the transparent layer 30 in a region of 100 mm × 100 mm, the pitch of the grooves 30a is 80 μm, the width of the grooves 30a is 40 μm, the depth of the grooves 30a is 80 μm, the length of the grooves 30a is 100 mm, and the cross-sectional shape is triangular. Groove 30a was formed. As a result, the groove 30a for forming the light scattering portion 20 having a louver structure could be formed.

  As a paste for forming the light scattering portion 20, the ultraviolet curable resin used when forming the transparent layer 30 is filled with titanium oxide fine particles (average particle size 0.2 μm, specific gravity 4.2) as a light scattering material. What was mixed so that it might become 2 vol% was prepared. The paste was supplied to the groove 30a of the transparent layer 30, and the excess was scraped off with a doctor blade. Then, the light-scattering part 20 was formed in the groove | channel 30a of the transparent layer 30 by irradiating an ultraviolet-ray and hardening a paste.

  Next, after applying the ultraviolet curable resin used when forming the transparent resin layer 30 on the transparent resin layer 30 and the light scattering portion 20, a transparent substrate is placed on the ultraviolet curable resin. After irradiating with ultraviolet rays, the transparent substrate is peeled off. Thereby, the transparent substrate 10 was formed on the transparent layer 30 and the light scattering portion 20.

  Next, two soda lime glasses (3 mm thickness) to be the first glass substrate 61 and the second glass substrate 62 and a PVB (Poly vinyl butyral) film (250 μm thickness) to be the adhesive layers 51 and 52 are prepared. did. Thereafter, a PVB film to be the adhesive layer 51 and the first glass substrate 61 are sequentially laminated on the transparent resin film 40, and a PVB film to be the adhesive layer 52 and the second glass are laminated on the transparent substrate 10. The substrates 62 are stacked in order. Thereafter, the image projection window having the structure shown in FIG. 5 was produced by vacuum thermocompression bonding.

  The image projection window manufactured by the above manufacturing method had a transmittance of 5% and a haze of 15. Of the light diffracted in the image projection window, the diffracted light having the highest intensity is the first-order diffracted light, and the diffraction efficiency of the first-order diffracted light is 5%. Further, 85% of the light transmitted through the video projection window is not diffracted by the video projection window.

(Example 2)
An image projection window was prepared in the same manner as in Example 1, except that in this example, the titanium oxide particles were 0.1 vol% as a paste for forming the light scattering portion 20, and carbon as a light absorbing material was used. What mixed black so that it might become 1.0 vol% was prepared. Further, a low refractive index resin (CH ₂ ═C (CH ₃ ) COOCH ₂ CH ₂ (CF ₂ ) ₆ F) is added to the paste, so that the refractive index of the light scattering layer 20 is 0. It adjusted so that it might become within 001.

  The manufactured video projection window had a high background and video contrast, and was more visible. Further, the transmittance was 65% and the haze was 9. Of the light diffracted in the image projection window, the diffracted light having the highest intensity is the first-order diffracted light, and the diffraction efficiency of the first-order diffracted light is 5%. Further, 85% of the light transmitted through the video projection window without being diffracted by the video projection window was 85%.

  As mentioned above, although the form which concerns on implementation of this invention was demonstrated, the said content does not limit the content of invention.

DESCRIPTION OF SYMBOLS 10 Transparent base material 20 Light-scattering part 30 Transparent layer 30a Groove 40 Transparent resin film 51 Adhesive layer 52 Adhesive layer 61 1st glass substrate 62 2nd glass substrate 90 Mold 90a Protrusion part 100 Image projection window 110 Projector

Claims (13)

A transparent layer,
A plurality of light scattering portions formed linearly inside the transparent layer;
A video projection structure comprising:
The plurality of light scattering portions are arranged at a predetermined interval,
Of the light diffracted in the image projection structure, the diffraction efficiency of the diffracted light having the highest intensity is 20% or less.   2. The video projection structure according to claim 1, wherein light that is not diffracted by the video projection structure is 60% or more of light transmitted through the video projection structure. 3.   The image projection structure according to claim 1, wherein a visible light transmittance in the image projection structure is 40% or more and 90% or less. The light scattering portion includes a light scattering material,
The image projection structure according to claim 1, wherein the light scattering material is a fine particle.   The image projection structure according to claim 4, wherein a concentration of the light scattering material included in the light scattering portion is 0.01 vol% or more and 5 vol% or less.   The image projection structure according to claim 1, wherein the light scattering portion includes a light absorbing material that absorbs light.   The image projection structure according to claim 6, wherein the light absorbing material is a material containing carbon black or titanium black.   The video projection structure according to claim 6 or 7, wherein the concentration of the light absorbing material included in the light scattering portion is 0.01 vol% or more and 5 vol% or less.   The video projection structure according to claim 1, wherein a difference between a refractive index of the transparent layer and a refractive index of the light scattering portion is 0.01 or less. If the width of the light scattering portion is A, the width of the areas not the light scattering portion is formed by B, where the average transmittance in the light scattering unit and T <sub>A,

(T A × A) / (</sub> A + B) + B / (A + B) ≧ 0.6

The video projection structure according to claim 1, wherein: Forming a resin material layer on the surface of the substrate, forming a plurality of grooves on the surface of the resin material layer, and curing the resin material to form a transparent layer;
Filling the groove in the transparent layer with a material containing a resin and a light scattering material and curing it to form a light scattering layer;
A method of manufacturing a video projection structure, comprising:   The method of manufacturing a video projection structure according to claim 11, further comprising a step of applying a photocurable resin on the surface of the transparent layer and the light scattering layer after forming the light scattering layer.   11. An image projection method, comprising: projecting an image from a projector onto the image projection structure according to claim 1, and visually recognizing the image transmitted through the image projection structure.

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