JP2008242090A - Reflection screen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reflection screen whose angle of view is wide, which reduces reflection of external light and a video source and whose contrast is high. <P>SOLUTION: The reflection screen is attained by providing an optical control layer 102 having actions of scattering and transmitting light made incident at an incident angle within a specific angle range and transmitting light made incident at other angles as it is without scattering on the observation surface side of a retroreflection layer 103 having retroreflectivity and providing a mat layer 101 on the surface of which a fine irregular shape 101a is formed on the observation surface side from the optical control layer 102. The optical control layer 102 is provided so that an incident angle range for scattering and transmitting the incident light is overlapped with an angle range α of the incident angle on which video light is mainly made incident. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a reflective screen that reflects and displays projected video light.

  Conventionally, a reflection screen using a reflective layer having retroreflectivity that reflects incident light in the same direction as the incident light is known (for example, Patent Document 1). Such a reflective screen has a problem that the viewing angle is narrowed because the image light is reflected only to the image source side due to the retroreflectivity.

Patent Document 2 discloses a reflective screen in which a reflective layer having a sawtooth reflective surface and a light control layer that scatters or transmits light depending on the incident direction are combined. However, the reflection screen of Patent Document 2 has a problem that a sharp image cannot be obtained due to a reflection of a video source such as a projector or indoor lighting. In addition, depending on the position of the image source, there is a problem that the image light is not reflected to the observer side and the image becomes very dark.
JP-A-6-75303 JP 2004-69836 A

  An object of the present invention is to provide a reflective screen having a wide viewing angle, reducing reflection of external light, an image source, and the like and having high contrast.

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to the Example of this invention is attached | subjected and demonstrated, it is not limited to this.
The invention of claim 1 is a reflection layer (103) having retroreflectivity, and is provided closer to the observation surface than the reflection layer, scatters and transmits light incident at an incident angle within a specific angle range, And a light control layer (102) that transmits light incident at other angles.
A second aspect of the invention is the reflective screen according to the first aspect of the invention, characterized in that the observation screen side has a fine uneven portion (101a).

According to the present invention, the following effects can be obtained.
(1) A reflective screen of the present invention is provided with a reflective layer having retroreflectivity and an observation surface side of the reflective layer, and scatters and transmits light incident at an incident angle within a specific angle range. A light control layer that transmits light incident at an angle other than, so that unnecessary external light is reflected in the same direction (external light source side) as the direction in which external light is incident, and the image light is observed by the observer It can be reflected and diffused to the side. Therefore, it is possible to prevent a decrease in contrast due to outside light, improve the contrast of the image, and widen the viewing angle of the image light.

(2) Since the observation surface side has a fine concavo-convex shape portion, regular reflection of external light to the observer side can be prevented, and the viewing angle can be improved by diffusing video light. Further, it is possible to prevent a hot spot or the like generated when a light source that emits image light is reflected.

  The present invention aims to provide a reflective screen having a wide viewing angle, reducing reflection of external light, an image source, and the like and providing a high-contrast reflection screen with a specific angle range on the observation side of the reflective layer having retroreflectivity. This is realized by providing a light control layer that scatters the incident light at, and transmits the incident light at other angles.

(Embodiment)
FIG. 1 is a diagram showing a reflective screen 10 of the present embodiment.
In addition, each figure shown below including FIG. 1 is the figure shown typically, and the magnitude | size and shape of each part are exaggerated suitably for easy understanding. FIG. 1 collectively shows the interior lighting (external light source) G, the video source L, the reflective screen 10, and the like, and includes portions that are different from the actual arrangement. Furthermore, numerical values such as dimensions and material names of each member described in the present specification are examples of the embodiment, and the present invention is not limited thereto, and may be appropriately selected and used.
The reflective screen 10 according to the present embodiment is a reflective screen that reflects the image light projected from the projector optical engine unit (image source) L to the viewer O side so that the image can be observed.

A straight line H shown in FIG. 1 is a virtual straight line that passes through the center of the reflective screen 10 and extends in the normal direction of the screen surface. The screen surface indicates a surface in the plane direction of the reflection screen when viewed as the entire reflection screen, and is used as the same definition in the following description.
In the present embodiment, the reflective screen 10 of the present embodiment is configured such that the image source L is installed below the center of the screen in the usage state of the screen, and the image light is projected obliquely upward, so that illumination light or the like is unnecessary. This is a reflection screen for a front projector that has been developed considering that most of the extraneous light enters from above the reflection screen 10.
Therefore, in the present embodiment, the image light is incident on the reflection screen 10 mainly at an incident angle within the angle range α, and unnecessary external light such as illumination light is incident mainly within the angle range β1. It is incident on the reflective screen 10 at an angle.
Note that the angle range β2 illustrated in FIG. 1 is an angle range in which light incident on the reflective screen 10 from below is incident, but in the present embodiment, the image source L and the external light source G illustrated in FIG. Due to the positional relationship with respect to the reflective screen 10, the amount of image light and external light incident within the angle range β2 is much greater than the amount of image light and external light incident within the angle ranges α and β1. The effect on the contrast and the like is very small. Therefore, in the following description, the image light and the external light are described assuming that the main incident angles with respect to the reflective screen 10 are within the angle ranges α and β1.

FIG. 2 is a cross-sectional view of the reflective screen 10 of the present embodiment. In FIG. 2, the right side is shown as the light source side (observation surface side), and the left side is shown as the back side.
The reflective screen 10 includes a mat layer 101, a light control layer 102, a retroreflective layer 103, and the like.
The mat layer 101 is a layer provided on the most observation surface side of the reflective screen 10, and a fine uneven shape 101a is formed on the surface thereof. In the present embodiment, the mat layer 101 is formed on the observation surface side of the light control layer 102 using a resin having optical transparency.
The light control layer 102 is provided closer to the observation surface than the retroreflective layer 103, scatters and transmits light incident at an incident angle within a specific angle range, and does not scatter light incident at other incident angles. It is a layer having a function of allowing light to pass through as it is.

The light control layer 102 of the present embodiment overlaps an incident angle range in which light is scattered and transmitted and an incident angle range α in which image light is mainly incident on the reflective screen 10 to scatter light. The incident angle that is transmitted without being overlapped with the angle range β1 of the incident angle through which external light is mainly incident overlap.
Therefore, in the present embodiment, the light control layer 102 scatters and transmits light incident at an incident angle within the angle range α (see FIG. 1) to the retroreflective layer 103 side. Further, the light control layer 102 transmits light incident at an incident angle within the angle ranges β1 and β2 as it is to the retroreflective layer 103 side without being scattered.
As this light control layer 102, a sheet disclosed in JP-A No. 64-77001, which has a refractive index different and has a directional interface, can be used. In this embodiment, Lumisty (registered trademark) manufactured by Sumitomo Chemical Co., Ltd. is used.

  The retroreflective layer 103 is a layer having an action (retroreflective) of reflecting light incident on the retroreflective layer 103 at a certain angle in a direction incident at the angle. In the present embodiment, minute spherical beads (not shown) are arranged on the observation surface side of the retroreflective layer 103. As the retroreflective layer 103, ellipsoidal micro beads are arranged on the observation surface side so that the reflection characteristics in two directions of the major axis direction and the minor axis direction can be controlled, or the reflecting surface has a prism shape. You may use what was formed.

As shown in FIG. 1, the image light is incident on the reflective screen 10 mainly at an angle smaller than the external light (an angle within the angle range α). This image light is not regularly reflected by the fine uneven shape 101 a of the mat layer 101. Therefore, according to the present embodiment, it is possible to prevent hot spots caused by the reflection of the video source.
The image light transmitted through the mat layer 101 enters the light control layer 102 and is scattered. This has a function of selectively scattering and transmitting light incident at an incident angle within a specific angle range, and the specific angle range is mainly used as an image. This is because it is provided so as to overlap with the angle range α where light is assumed to be incident.
The image light scattered by the light control layer 102 is retroreflected by the retroreflective layer 103, is scattered again by the light control layer 102, is diffused by the fine uneven shape 101 a of the mat layer 101, and is emitted to the observer O side.
Therefore, according to this embodiment, the image light can be efficiently reflected toward the observer O, and the viewing angle can be improved.

On the other hand, unnecessary external light such as illumination light is incident at an angle larger than the incident angle of the image light (an angle within the angle range β1) mainly from above the reflection screen 10, as shown in FIG. . This external light is not regularly reflected by the fine uneven shape 101 a of the mat layer 101 provided on the most observation surface side of the reflective screen 10. Therefore, according to this embodiment, reflection of external light on the surface of the reflective screen 10 can be prevented.
Since the external light transmitted through the mat layer 101 is incident on the light control layer 102 at an incident angle outside the range of the incident angle range in which the light is scattered and transmitted by the light control layer 102, the light is transmitted through the light control layer 102 as it is. Then, the light is retroreflected by the retroreflective layer 103, passes through the light control layer 102 again, and exits in the incident direction. Note that the external light is diffused by the uneven shape 101a of the mat layer 101, but the external light that is emitted toward the observer O side is small, and most of the light is emitted toward the external light source G side. There is little effect on the image light
Therefore, according to the present embodiment, it is possible to prevent a reduction in the contrast of an image caused by reflection of external light toward the observer O side.

As described above, according to the present embodiment, the external light is retroreflected in the direction in which the external light is incident (in this embodiment, the external light source G side such as indoor lighting), and the image light is on the observer O side. Can be reflected and diffused efficiently, so that a reflective screen with a wide viewing angle and high contrast can be obtained.
In addition, the mat layer 101 can prevent reflection of external light and hot spots.
Furthermore, since the mat layer 101 and the light control layer 102 are provided, the effect of diffusing video light and improving the viewing angle can be enhanced.
Furthermore, an incident angle range in which the incident light of the light control layer 102 is scattered and an incident angle range in which the incident light is transmitted without being scattered are a main incident angle range of image light (an angle range α shown in FIG. 1), and Since the light control layer 102 having optimal characteristics can be selected as appropriate so as to overlap with the main incident angle range of external light (angle range β1 shown in FIG. 1), the external light of the environment where the reflective screen 10 is used. In addition, it is possible to produce a reflective screen that matches the incident angle of the image light.

(Deformation)
The present invention is not limited to the embodiment described above, and various modifications and changes are possible, and these are also within the scope of the present invention.
(1) In this embodiment, an example is shown in which a mat layer 101 is provided on the observation surface side of the light control layer 102, which is a layer separate from the light control layer 102 and has a fine uneven shape 101a on the observation surface side surface. However, the present invention is not limited thereto, and for example, a fine uneven shape may be formed on the observation surface side surface of the light control layer 102.

(2) The reflective screen 10 may be formed using a flexible material and may be a rollable reflective screen.
It should be noted that the present embodiment and each modified embodiment can be used in appropriate combination, but detailed description thereof is omitted.

It is a figure which shows the reflective screen 10 of this embodiment. It is sectional drawing of the reflective screen 10 of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Reflective screen 101 Matte layer 101a Fine uneven | corrugated shape 102 Light control layer 103 Retroreflective layer

Claims (2)

A reflective layer having retroreflectivity;
A light control layer that is provided closer to the observation surface than the reflective layer, scatters and transmits light incident at an incident angle within a specific angle range, and transmits light incident at other angles;
Reflective screen with. The reflective screen according to claim 1.
On the observation surface side, having a fine uneven shape part,
Reflective screen featuring.

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