WO2013042168A1

WO2013042168A1 - Reflective screen

Info

Publication number: WO2013042168A1
Application number: PCT/JP2011/005324
Authority: WO
Inventors: 政敏丹羽; 一丸田; 誠楚山
Original assignee: 株式会社有沢製作所
Priority date: 2011-09-21
Filing date: 2011-09-21
Publication date: 2013-03-28
Also published as: CN203882085U

Abstract

In order to address the problem of providing a reflective screen that prevents light which has been diffusely reflected by the apex portion of protruding parts from entering a user's, that is, an observer's, field of view, and reducing the contrast, this reflective screen is equipped with: a plate-shaped base part; multiple prism parts provided on one face of the base part and having a pair of intersecting faces at least one of which is inclined from the normal line direction of the aforementioned one face; reflecting parts which reflect light and are formed on one of the faces of the pairs of faces of each prism part; and multiple light-absorbing layers which absorb light and are provided straddling the apex portion between the aforementioned one face and the other face of the pair of faces of each prism part.

Description

Reflective screen

The present invention relates to a reflective screen.

A reflection type screen is known in which image light is reflected by a reflecting member provided on an inclined surface of a protrusion having a triangular cross section (see, for example, Patent Document 1).
[Patent Document 1] Japanese Patent Application Laid-Open No. 2003-156799

However, the reflective screen has a problem that the light diffusely reflected by the top of the ridge enters the field of view to the user who is an observer and the contrast is lowered.

In the first aspect of the present invention, a flat base portion and a plurality of surfaces having a pair of surfaces provided on one surface of the base portion, at least one inclined from the normal direction of the one surface and intersecting each other. Between the prism portion, the reflecting portion that reflects light formed on one surface of the pair of surfaces of each prism portion, and the one surface and the other surface of the pair of surfaces of each prism portion A reflective screen is provided that includes a plurality of light absorbing layers that absorb light provided across the top of the screen.

Note that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

1 is an overall configuration diagram of a projector system 10. FIG. 1 is an overall perspective view of a reflective screen 14. FIG. 3 is an enlarged cross-sectional view of a reflective screen 14. FIG. It is an expanded sectional view of another reflective screen 114. It is an expanded sectional view of another reflective screen 214.

Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

FIG. 1 is an overall configuration diagram of the projector system 10. As shown in FIG. 1, the projector system 10 includes a projector 12 and a reflective screen 14. The projector 12 outputs image light PL for forming an image to the reflective screen 14. The reflective screen 14 reflects the image light PL forward. Thereby, the user can see the image projected on the reflective screen 14.

FIG. 2 is an overall perspective view of the reflective screen 14. FIG. 3 is an enlarged cross-sectional view of the reflective screen 14. As shown in FIGS. 2 and 3, the reflective screen 14 includes a base portion 20, a plurality of prism portions 24, a plurality of reflection layers 26, and a plurality of light absorption layers 28.

The base portion 20 is formed in a rectangular flat plate shape when viewed from the front. Examples of the material constituting the base portion 20 are acrylic resin, epoxy resin, polycarbonate resin, polyester resin, styrene resin, and acrylic styrene copolymer resin. The material constituting the base portion 20 may be a plate-curable material or a flexible material that can be wound up.

The plurality of prism portions 24 are provided on the front surface of the base portion 20. The prism portion 24 includes a light absorbing material. An example of the material constituting the prism portion 24 includes urethane containing carbon black. The prism portion 24 is formed in a triangular prism shape extending linearly along the horizontal direction. The length of the prism portion 24 in the horizontal direction is equal to the length of the base portion 20 in the horizontal direction. The prism portion 24 is provided over the entire length of the base portion 20 in the horizontal direction. Each prism part 24 is arrange | positioned mutually parallel. The plurality of prism portions 24 are periodically arranged along the vertical direction. An example of the pitch of the prism portions 24 is 100 μm to 300 μm. An example of the height in the front-rear direction of the prism portion 24 is 70 μm to 200 μm. The prism portion 24 is transferred and molded by a molding die or the like.

The prism portion 24 has an upper surface 32 and a lower surface 34. The upper surface 32 and the lower surface 34 are an example of a pair of surfaces. The lower surface 34 is an example of one surface of a pair of surfaces, and the upper surface 32 is an example of the other surface of the pair of surfaces.

The upper surface 32 is formed in a rectangular flat shape. The upper surface 32 is disposed above the lower surface 34. The upper surface 32 may be parallel to the normal direction of the base portion 20, and may be inclined downward from the normal direction of the base portion 20 when viewed from the base portion 20.

The lower surface 34 is formed in a rectangular planar shape. The lower surface 34 is disposed below the upper surface 32. The lower surface 34 is disposed upstream of the upper surface 32 in the traveling direction of the image light (also referred to as projector light) PL. The lower surface 34 and the upper surface 32 intersect each other. The lower surface 34 is inclined from the normal direction of the base portion 20 when viewed from the base portion 20.

An example of the lower angle θ between the lower surface 34 of the prism portion 24 and the front surface of the base portion 20 is 40 °. It should be noted that the lower angles θ of the prism portions 24 are preferably all equal from the viewpoint of simplifying the manufacturing process. On the other hand, the lower angle θ of each prism portion 24 is preferably different from the viewpoint of improving the image quality. When the lower angles θ are made different, it is preferable that the expected incident angle α and the lower angle θ of the image light PL incident on each prism portion 24 are made to correspond and gradually change. For example, “2θ = α” is preferable. The incident angle α is an angle between the traveling direction of the image light PL and the horizontal direction.

The reflective layer 26 is formed on the lower surface 34 of each prism portion 24. The reflective layer 26 is made of a reflective paint containing titanium oxide, mica, and silica that serves as a diffusing agent that diffuses light. The reflection layer 26 diffuses and reflects the image light PL output from the projector 12. An example of the thickness of the reflective layer 26 is 10 μm to 20 μm. The reflective layer 26 is formed over the entire length of the lower surface 34 in the horizontal direction. The reflective layer 26 is provided from the top 40 between the upper surface 32 and the lower surface 34 to the middle portion of the lower surface 34. The top portion 40 is a portion where the upper surface 32 and the lower surface 34 intersect in each prism portion 24. Note that the reflective layer 26 may be formed from the top 40 to the bottom 42. The bottom portion 42 is a portion where the upper surface 32 of the prism portion 24 and the lower surface 34 of the adjacent prism portion 24 intersect.

The light absorption layer 28 is provided across the top 40 between the upper surface 32 and the lower surface 34 of each prism portion 24. An example of the material constituting the light absorption layer 28 includes urethane containing carbon black. The light absorption layer 28 absorbs light including external light that enters the vicinity of the top portion 40. An example of the thickness of the light absorption layer 28 is 5 μm to 10 μm. The light absorption layer 28 is formed over the entire length of the upper surface 32 and the lower surface 34 in the horizontal direction. The light absorption layer 28 is formed on the upper surface 32 from the top 40 to the middle of the upper surface 32. The light absorption layer 28 may be formed on the upper surface 32 from the top 40 to the bottom 42 of the upper surface 32. The light absorption layer 28 is formed on the reflection layer 26 on the lower surface 34 side. The light absorption layer 28 is formed from the top 40 to the middle of the reflective layer 26 on the lower surface 34 side. Therefore, the reflective layer 26 is exposed from the light absorption layer 28. The area of the light absorption layer 28 on the upper surface 32 side is larger than the area of the light absorption layer 28 on the lower surface 34 side. From the viewpoint of gain, the light absorption layer 28 is preferably formed only in the vicinity of the top 40 on the lower surface 34 side. As a result, most of the reflective layer 26 is exposed from the light absorbing layer 28, reducing the proportion of the video light PL absorbed by the light absorbing layer 28, and increasing the proportion of the reflected light reflected by the reflective layer 26. .

Next, the function of the reflective screen 14 will be described. The reflective screen 14 diffuses the image light PL output from the projector 12 by the reflective layer 26 and reflects it forward. Thereby, an image is formed by the image light PL, and the user can view the image. On the other hand, of the external light other than the image light PL, the external light that has reached the region where the reflective layer 26 is not formed is absorbed by the prism portion 24 or the light absorption layer 28 and is not reflected. In particular, outside light reaching the vicinity of the top 40 indicated by a dotted arrow in FIG. 3 is absorbed by the light absorption layer 28 without being diffusely reflected by the top 40.

As described above, the reflective screen 14 has the light absorption layer 28 formed so as to straddle the top 40. As a result, the reflective screen 14 can absorb the external light reaching the vicinity of the top 40, which causes a significant reduction in contrast, without diffuse reflection. As a result, the reflective screen 14 can improve the contrast.

Next, an experiment relating to the above-described reflective screen 14 will be described. As a comparative example to be compared with the reflection type screen 14 described above, a reflection type screen in which the light absorption layer 28 was removed from the reflection type screen 14 was created. The size of the reflective screen 14 of this embodiment and the comparative example was 80 inches with an aspect ratio of 9:16. The reflective screen 14 of this embodiment and the comparative example were irradiated with light by a projector PDG-DWL2500 manufactured by Sanyo Electric. In each experiment, the luminance meter used was BM-7A manufactured by Topcon. This luminance meter was installed at a distance of 3000 mm forward from the center of the reflective screen 14, and the measurement range was set to 1 °.

First, the gain of the reflective screen 14 of this embodiment and the gain of the comparative example were examined. The gain was calculated by equation (1).
Gain = Brightness of reflective screen / (Illuminance of projector / π) (1)
The brightness of the reflective screen and the illuminance of the projector were both measured at the center of the reflective screen. The gain of the reflective screen 14 of this embodiment is 0.44, and the gain of the comparative example is 0.55. Therefore, the gain of the present embodiment is smaller than that of the comparative example.

Next, the viewing angle of the reflective screen 14 of this embodiment and the viewing angle of the comparative example were examined. The viewing angle here is an angle at which the gain becomes half of the maximum value. The maximum gain value is measured at 0 °. While the luminance at the center of the reflective screen was measured with the luminance meter, the luminance meter was rotated from 0 ° to 80 ° in the horizontal direction, and the viewing angle was examined. The viewing angles of the reflective screen 14 of this embodiment and the comparative example were both 80 °.

Next, the luminance uniformity of the reflective screen 14 of the present embodiment and the luminance uniformity of the comparative example were examined. The brightness uniformity was calculated by measuring the brightness of each area obtained by dividing the reflective screen into 9 parts vertically and horizontally, and substituting the measurement result into the following formula (2).
Brightness uniformity [%] = (luminance min / luminance max) × 100 (2)
The luminance min is the minimum luminance value among the luminances measured in the nine divided areas. The luminance max is the maximum luminance value among the luminances measured in the nine divided areas. The luminance uniformity of the reflective screen 14 of this embodiment and the comparative example was 86%.

Next, the contrast of the reflective screen 14 of the present embodiment and the contrast of the comparative example were examined. Contrast was examined by equation (3).
Contrast = white image brightness / black image brightness (3)
The white video luminance is the luminance at the center of the reflective screen when an all white pattern having a maximum input signal of 100% is projected onto the reflective screen 14. The black video luminance is the luminance at the center of the reflective screen when an all white pattern having a minimum input signal of 0% is projected onto the reflective screen 14. In addition, both the white image luminance and the black image luminance were irradiated with illumination light L having a screen center of 100 lx (= lux). The contrast of the reflective screen 14 of the present embodiment was 30, whereas the contrast of the comparative example was 20. That is, the reflective screen 14 of this embodiment can improve the contrast by 50% compared to the comparative example. Thereby, it can be seen that the reflective screen 14 of the present embodiment can improve the contrast even in the presence of external light.

The shape, arrangement, number, material, and the like of each component in the above-described embodiment may be changed as appropriate.

FIG. 4 is an enlarged cross-sectional view of another reflective screen 114. As shown in FIG. 4, the prism portion 24 may be bonded to the base portion 20 via the adhesive layer 122. The adhesive layer 122 is applied to the entire front surface of the base portion 20. The adhesive layer 122 is made of an adhesive material. An example of the material constituting the adhesive layer 122 is an acrylic adhesive. The adhesive layer 122 adheres the plurality of prism portions 24 to the front surface of the base portion 20. In the case of the reflective screen 114, the base portion 20 and the prism portion 24 may be separately manufactured and then bonded through the adhesive layer 122.

Any one or two of the base portion 20, the adhesive layer 122, and the prism portion 24 include a light absorbing material, and the other is formed of a material that can transmit light. Instead, any of the base part 20, the adhesive layer 122, and the prism part 24 may include a light absorbing material, or any of them may be formed of a material that can transmit light.

FIG. 5 is an enlarged cross-sectional view of another reflective screen 214. As shown in FIG. 4, the reflective screen 214 has a blank portion 222 provided between the base portion 20 and the prism portion 24. The blank part 222 is formed in substantially the same shape as the base part 20. The blank part 222 is formed integrally with the prism part 24. The blank part 222 may be formed by a mold together with the prism part 24, or after the blank part 222 is applied to the base part 20 and semi-cured, the prism part 24 is formed on the blank part 222. And may be integrated by curing together. The blank part 222 is provided between the prism part 24 and the base part 20.

The base portion 20 includes a light absorbing material and has a function of absorbing light. On the other hand, the blank part 222 and the prism part 24 are formed of a material capable of transmitting light. Instead, the base portion 20 may be formed of a material that can transmit light, and the blank portion 222 and the prism portion 24 may include a light absorbing material. Instead of these, any of the base part 20, the blank part 222, and the prism part 24 may contain a light absorbing material.

The surface of the lower surface 34 may function as a reflective surface, and the reflective layer 26 may be omitted.

As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

The execution order of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior”. It should be noted that they can be implemented in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for the sake of convenience, it means that it is essential to carry out in this order. is not.

Claims

A flat base portion;
A plurality of prism portions provided on one surface of the base portion and having a pair of surfaces that are inclined at least one from the normal direction of the one surface and intersect each other;
A reflecting portion that reflects light formed on one surface of the pair of surfaces of each prism portion;
A reflective screen comprising: a plurality of light absorbing layers that absorb light provided across the tops between the one surface and the other surface of the pair of surfaces of each prism portion.
The reflective screen according to claim 1, wherein the prism portion includes a light absorbing material.
The base portion includes a light absorbing material,
The reflective screen according to claim 1, wherein the prism portion is made of a material capable of transmitting light.
The reflective screen according to claim 1, wherein the reflection unit includes a diffusing agent that diffuses light.