JPH0667307A - Retroreflection screen - Google Patents

Abstract

(57) [Abstract] [Object] An object of the present invention is to provide a screen having a retroreflective property and a wide service area. [Structure] A vapor deposition film 2 having a top gain of 12 to 25 is laminated on the surface of a substrate 1, and a plurality of beads 3 having a refractive index of 1.9 to 2.3 are laminated on the surface of the vapor deposition film 2 and a transparent layer having a refractive index of 1.4 to 1.5. 4, the retroreflective layer 5 fixedly formed is laminated, and the matte layer 6 having a haze of 50 to 80 is laminated on the surface of the retroreflective layer 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen having retroreflectivity.

[0002]

2. Description of the Related Art Conventionally, as a movie screen for hot spot countermeasures, FIG.
By fixing a plurality of glass beads 22 on the surface of the white reflecting material 21 as shown in FIG.
A bead screen (screen β described later) that collects reflected light in the light source direction has been proposed.

However, this bead screen has no effect unless the beads are arranged on the incident side surface because the refractive index of the beads is the current glass (refractive index n = 1.5 to 1.55). However, it is effective as a countermeasure against hot spots, but there is a drawback that the screen cannot be washed because the beads are lost when used for a long time or the beads are lost when the beads are soiled.

In addition, there are various problems such as an optical glare and an iridescent phenomenon.

The present invention aims to provide a screen that solves these drawbacks.

[0006]

The gist of the present invention will be described with reference to the accompanying drawings.

A vapor deposition film 2 having a top gain of 12 to 25 is laminated on the surface of a substrate 1, and a plurality of beads 3 having a refractive index of 1.9 to 2.3 are laminated on the surface of the vapor deposition film 2 and a transparent layer having a refractive index of 1.4 to 1.5. The present invention relates to a retroreflective screen in which the retroreflective layer 5 fixedly formed in 4 is laminated, and the matte layer 6 having a haze of 50 to 80 is laminated on the surface of the retroreflective layer 5.

[0008]

The retroreflective layer 5 has a retroreflective property, and since the refractive index of the beads 3 and the transparent layer 4 is set to a predetermined value, the service area can be widened. Since the beads 3 are protected by the transparent layer 4 and the matte layer 6 without being exposed, the beads 3 are not lost, and since the matte layer 6 is present on the surface, the screen is free from glare.

[0009]

EXAMPLES A perfect diffuser plate (generally Mgo powder adhered thereto) refers to a diffuser plate having the property that the brightness of any reflected light of the light applied to the perfect diffuser plate is equal.

On the other hand, the imperfect diffuser means that the brightness of the reflected light of the light irradiated on the imperfect diffuser becomes non-uniform.

When the brightness (gain) of the reflected light from the perfect diffuser is 1, and the gain of the reflected light from the imperfect diffuser is 12, the reflected light is from the perfect diffuser. It is said that a reflected light that is 12 times brighter than that is generated, and if the reflected light of this gain 12 is the brightest reflected light among the reflected lights of the incomplete diffuser, this incomplete diffuser has a top gain of 12. Say.

Haze is the degree of haze (cloudiness value),

[0013]

[Equation 1]

It is represented by The larger the haze, the more cloudy and less transparent it is.

Further, the retroreflection means that most of the reflected light returns to a narrow range on the incident light side, as shown in FIGS. 1 and 2, that is, most of the reflected light has a reflection angle with little change with respect to the incident angle. It has the property of becoming reflected light.

Specifically, when the light incident on the screen in FIG. 1 is specularly reflected, that is, when the screen is a sparse surface, the characteristic of the screen is represented by the curve of x in FIG. , A screen having retroreflectivity is shown in FIG.
Is represented by the curve.

Therefore,

[0018]

[Equation 2]

Is a tentative guide for the determination of retroreflectivity.

Recently, a large number of home projectors have become popular.

By the way, since the room is naturally small, the distance between the projector and the screen becomes short.

Therefore, in the screen corner portion, the reflected light diffuses and escapes, but it is desirable that the reflected light returns to the light source (projector) side as much as possible without escaping. That is, a screen having retroreflectivity is desirable.

The screen according to the present embodiment has retroreflectivity, and further, the service area (bright part of the screen) can be made very wide.

This has been confirmed by the following experiment. The data of each component of the screen according to this example used in this experiment are as follows.

Vapor-deposited film 2: Top gain 25-Beads 3: Refractive index 2.25-Transparent layer 4: Refractive index 1.48-Mat layer 6: Haze 80 i) Regarding retroreflectivity, FIG. The following is a comparison table of data regarding retroreflectivity between a bead screen (hereinafter referred to as a screen α) and a conventional bead screen (hereinafter referred to as a screen β; white reflector: top gain 0.95, beads: refractive index 1.5). The numerical values in this table are the values of B / A described above.

As is apparent from the table of FIG. 3, it can be confirmed that the retroreflectivity of the screen α is similar to that of the screen β. Therefore, the screen α is
The screen also has a bright screen corner.

Ii) Size of Service Area FIG. 4 is a comparison table of data on the size of service areas of the screens α and β. This FIG. 4 is viewed as follows.

For example, in the case of the screen α, the top gain is 2.7 and the place where the brightness becomes 1/2 of the top gain is ± 19.4 ° with respect to the position where the top gain is obtained (in this case, the light source). , Brightness is top gain 1
This means that the position where the angle becomes / 3 is ± 26.5 ° with respect to the light source.

Therefore, for example, regarding the screen α and the screen β of FIG. 4, the places where the 1/2 top gain and the 1/3 top gain are illustrated in an explanatory manner as shown in FIGS.

Therefore, the range in which the screen α has a brightness equal to or higher than ⅓ of the top gain is wider than the screen β, which means that the screen α has a larger service area than the screen β. It is a wide screen.

It is generally said that human beings perceive that it becomes dark when the brightness is ⅓ or less of the top gain.
Therefore, the numerical value of 1/3 top gain in FIG. 4 is a criterion for determining the brightness of the screen, that is, the size of the service area.

Iii) About Glitter of Screen Since the screen according to this embodiment has the matte layer 6 formed on the surface thereof, an image without glare can be observed.

From the above, the screen of this embodiment has retroreflectivity and is bright at the screen corners.
It has been confirmed that the screen has a wide service area due to the wide range in which the / 3 top gain can be obtained, and that it is a very excellent screen for observing glare-free images.

The present inventors have completed this embodiment having the configuration shown in FIG. 7 from the above basic data and the following data regarding each constituent material.

A) Vapor-deposited film 2 Non-directional vapor-deposited film 2 with top gain 25.6 (manufactured by Toyo Metallizing Co., Ltd.), directional vapor-deposited film 2 with top gain 12.0 (manufactured by Acrymir Co., Ltd.), top gain 5.2 Three types of white mats (PET film: manufactured by Teijin Ltd.) were examined (experiments were conducted by using a screen having the same configuration as the above-mentioned example and changing the top gain of the vapor deposition film 2). .

As a result, the following conclusions were obtained.

In the case of the vapor-deposited film 2, by forming the matte layer 6 on the beads 3 and the surface, the vapor-deposited film 2 may or may not have directivity, but the screen becomes non-directional.

It is well known that the top gain of the screen is influenced by the top gain of the reflective material. Therefore, it is preferable that the vapor-deposited film 2 has a diffusive property rather than a mirror surface.

On the other hand, when the reflecting material is white mat, the diffusivity is strong, so that the gain is low and the retroreflectivity is not sufficiently exhibited.

From the above, it was judged that the vapor-deposited film 2 was good as the reflecting material, the presence or absence of directivity was irrelevant, and the vapor-deposited film 2 had a top gain of 12 to 25th optimal.

(B) Transparent Layer 4 It was examined how the refractive index of the transparent layer 4 used for bonding the matte layer 6 affects the characteristics of the screen (a screen having the same structure as that of the above-mentioned embodiment was used). Experiments were carried out using the beads 3 with appropriate changes in the refractive index.

As a result, the following conclusions were obtained.

It was found that the lower the refractive index of the transparent layer 4, the higher the top gain of the screen.

The lower the refractive index of the transparent layer 4, the narrower the 1/3 top gain.

It was found that the lower the refractive index of the transparent layer 4, the better the retroreflectivity of the screen.

From this experiment, a refractive index of 1.
A urethane type ultraviolet curable resin (UV resin) manufactured by Nippon Kayaku Co., Ltd. of 4 to 1.55 was selected.

C) Beads 3 It was examined how the refractive index and particle size of the beads affect the screen characteristics.

Specifically, GB-731 (refractive index 1.53, manufactured by Toshiba Ballotini Co., Ltd.,
φ = 30 μm on average) GB-D (refractive index 1.53, φ manufactured by Toshiba Ballotini Co., Ltd.
= 212-300 μm on average) HGB210 (refractive index 1.93, made by Toshiba Ballotini Co., Ltd.
φ = 37 μm on average) WGB210 (refractive index 2.25, made by Toshiba Ballotini Co., Ltd.
Experiments were carried out using four types of beads (φ = average 5 to 44 μm) (a screen having the same configuration as that of the above-mentioned example was used and the refractive index of the beads 3 was changed).

As a result, the following conclusions were obtained.

The lower the refractive index of the beads, the better the diffusivity. The higher the refractive index of the beads, the higher the top gain.

Regarding the retroreflectivity, beads having a low refractive index are also effective when the mat layer 6 and the transparent layer 4 are not provided, but when the mat layer 6 and the transparent layer 4 are used,
The greater the difference in refractive index from the matte layer 6, the better the retroreflectivity.

With respect to the particle size, the smaller the particle size, the more the glare can be reduced, and the screen has a good resolution.

From the above, it was found that the beads having a high refractive index and the smallest particle size, specifically, those having a refractive index of about 1.9 to 2.3 were optimal.

Therefore, the WGB-210 having the highest refractive index available at present is selected.

D) Adhesive 7 Since the material and thickness of the adhesive 7 do not affect the screen characteristics so much, any adhesive 7 may be used as long as it is transparent. The adhesive 7 used for the substrate 1 does not have to be transparent.

E) Matte layer 6 The necessity of the matte layer 6 was examined. If the mat layer 6 is not formed on the surface, glare occurs, and the ratio of specular reflection also increases in the retroreflectivity curve (see FIG. 2). Therefore, as a result of conducting an experiment using a screen having the same configuration as that of the above-mentioned embodiment and appropriately changing the haze of the mat layer 6, a PVC mat film having a haze of 60 to 80 with a satin finish on the surface (K.K. Takato Kasei Co., Ltd.) was selected.

When the haze is 60 or less, the top gain becomes too high and the 1/2 top gain becomes narrower.
The retroreflective curve also has a peak at + 60 °, which is not preferable for a screen.

A screen is manufactured as follows using each of the constituent materials selected as described above.

On the surface of the vapor-deposited film 2, a pressure-sensitive adhesive 7 is applied, glass beads 3 are fixed, and a PVC mat film as a mat layer 6 having irregularities is formed of a transparent UV-curable resin as a transparent layer 4. It is laminated on the surface of the beads 3 via (UV resin), and finally the PVC film as the substrate 1 is attached to the back surface of the vapor deposition film 2 via the adhesive 7. Therefore, in this embodiment, the vapor deposition film 2 is subjected to adhesive processing,
Since it is manufactured by simple processes such as bead adhesion and UV curing, it is possible to consider cost reduction sufficiently.

[0060]

Since the present invention is constructed as described above,
The bead is protected by the surface layer, the bead does not drop out, and the retroreflective screen has the characteristics of good retroreflectivity and a wide service area.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of retroreflection.

FIG. 2 is an explanatory graph related to the above.

FIG. 3 is a characteristic comparison table between the present embodiment and a conventional example.

FIG. 4 is a characteristic comparison table between the present embodiment and a conventional example.

5 is an explanatory diagram related to FIG. 4. FIG.

6 is an explanatory diagram related to FIG. 4. FIG.

FIG. 7 is an enlarged structural explanatory diagram of the present embodiment.

FIG. 8 is an enlarged view of the structure of the conventional example.

[Explanation of symbols]

 1 Base Material 2 Vapor Deposition Film 3 Beads 4 Transparent Layer 5 Retroreflective Layer 6 Matte Layer

Claims (1)

[Claims] 1. A vapor deposition film having a top gain of 12 to 25 is laminated on the surface of a substrate, and the surface of the vapor deposition film has a refractive index of
A retroreflective layer formed by fixing multiple beads of 1.9 to 2.3 with a transparent layer having a refractive index of 1.4 to 1.5 is laminated, and a matte layer of haze 50 to 80 is laminated on the surface of this retroreflective layer. Reflective screen.