JP4810839B2 - Transmission screen - Google Patents

Description

  The present invention relates to a transmission screen used for a rear projection television or the like.

  Conventionally, a transmissive screen used in a rear projection type projection television for observing an image by enlarging and projecting an image from an image projection device such as a liquid crystal panel on the screen from the back is a combination of a Fresnel lens sheet and a lenticular lens sheet. The Fresnel lens sheet is used to direct the image light from the image projection device in the direction in which the observer is present, and to uniformly brighten the entire screen.

  On the other hand, a lenticular lens sheet in which convex lenses that refract image light in the horizontal direction are arranged acts to refract and diffuse image light from the image projection device in the left-right direction where the observer is present, and the horizontal field of view. It is used to widen the corner, that is, the observation area so that many people can observe. In addition, a diffusion plate for diffusing the image light in the vertical direction and refracting and diffusing the image light from the image projection apparatus to some extent in the vertical direction where the observer is present and a screen for forming an image on the screen are used. In general, the diffusion plate is generally laminated and used on a flat surface opposite to the lenticular lens layer of the lenticular lens sheet.

  In the rear projection type projection television as described above, development called scintillation that has not become obvious in an apparatus using a CRT as an image source is a problem. This causes glare on the screen due to fine light and darkness, and is also called speckle.

As a method for reducing such scintillation, a lenticular lens sheet having a diffusion layer in which a large amount of a diffusing agent is dispersed is known. The diffusion layer of a conventional lenticular lens sheet is a lenticular lens through a resin-made translucent substrate. It is common to face the layer and be placed on the viewer side.
However, although the diffusion layer in which the diffusing agent is dispersed reduces scintillation, there is a problem that as the amount of the diffusing agent to be dispersed increases, the transmittance of the image light is reduced and the contrast is lowered.

The known literature is shown below.
JP 2004-77781 A

  An object of the present invention is to provide a transmission screen capable of solving the above-described problems and reducing scintillation.

In order to solve the above-mentioned problem, the present invention provides a transmission screen comprising at least a Fresnel lens sheet and a lenticular lens sheet, wherein the Fresnel lens sheet includes a Fresnel lens layer and the Fresnel lens. And a first diffusion layer in which a diffusion material disposed opposite to each other with a light-transmitting substrate is dispersed, and the lenticular lens sheet includes a lenticular lens layer and a second diffusion layer in which the diffusion material is dispersed And a third diffusion layer, wherein the third diffusion layer is disposed opposite to the lenticular lens layer via the second diffusion layer , and the diffusivity of the first diffusion layer and the second diffusion The diffusivity of the layer and the diffusivity of the third diffusion layer have a relationship of third diffusion layer> first diffusion layer> second diffusion layer, and the thickness of each layer is
The transmission screen is characterized by having a relationship of second diffusion layer> third diffusion layer ≧ first diffusion layer .

A second aspect of the present invention is the transmission type screen according to the first aspect, wherein the light source side surface of the first diffusion layer has a fine uneven shape.

The invention according to claim 3 is the transmission type screen according to any one of claims 1 to 2, wherein the second diffusion layer is formed by dispersing a diffusing agent on the light-transmitting substrate by melt extrusion molding.
A transmissive screen characterized by the following.

According to a fourth aspect of the present invention, in the transmission type screen according to any one of the first to third aspects, the surface of the third diffusion layer on the viewer side is selected from a hard coat treatment, an antistatic treatment, and an antireflection treatment. It is a transmissive screen characterized by having a configuration in which at least one kind of surface treatment is performed.

  According to the present invention, the first diffusion layer is disposed on the image light incident surface opposite to the Fresnel lens layer of the Fresnel lens sheet, and the diffusing agent is dispersed on the exit light beam surface of the lenticular lens sheet opposite to the lenticular lens layer. The second diffusion layer and the third diffusion layer are arranged to face each other, have three diffusion layers in the transmissive screen, and have an uneven surface on the incident surface of the first diffusion layer. Thus, the light can be sufficiently diffused. Furthermore, the diffusivity of the first diffusion layer is made larger than the diffusivity of the second diffusion layer, the diffusivity of the third diffusion layer is made larger than the diffusivity of the first diffusion layer, and the layer thickness of the third diffusion layer is increased. The scintillation can be reduced by reducing the scintillation and the contrast generated by making the thickness of the second diffusion layer larger than the thickness of the third diffusion layer. Can be balanced. With the above-described configuration, it is possible to provide a transmission screen that can reduce the occurrence of scintillation while suppressing a decrease in contrast.

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First embodiment)
Fig.1 (a) is the perspective view which showed 1st Embodiment of the transmission type screen 10 of this invention. Moreover, FIG.1 (b) is sectional drawing of the transmission type screen of this invention. As shown in FIG. 1A, the transmissive screen 10 of the present invention has, for example, a configuration in which a Fresnel lens sheet 30 and a lenticular lens sheet 20 are sequentially combined from the image light incident side.

  As shown in FIG. 1B, the Fresnel lens sheet 30 has a sawtooth-shaped Fresnel lens layer 31 formed concentrically on a resin base material, and the Fresnel lens layer 31 sandwiches a translucent substrate 32. The first diffusion layer 33 is disposed on the opposite surface. The Fresnel lens sheet 30 used in the transmission screen of the present invention is a mold using a mold by heating a base material such as polystyrene resin, acrylic resin, polycarbonate resin, vinyl chloride resin, etc., in a hot press in a flat press. The Fresnel lens layer 31 can be formed by a pressing method. In addition, the Fresnel lens layer may be provided by a method of extruding the above resin on the surface of a substrate extruded in a molten state using an embossing roll mold by melt extrusion molding using an extruder. Furthermore, using an ultraviolet curable resin or an electron beam curable resin, for example, the resin composition is applied to the molding surface of an embossing roll mold having a lens reverse shape, and the substrate is supplied to the embossing roll mold. Then, the resin is cured by irradiation with ultraviolet rays or ionizing radiation through the base material, and at the same time, the Fresnel lens layer 31 made of the resin-cured molding is polymerized and bonded to the base material, and is transferred and formed. You can also.

The first diffusion layer 33 is obtained by dispersing a diffusing agent 33a in a translucent resin substrate and has a fine uneven shape 33b on the incident light side surface.
Examples of the diffusing agent 33a include inorganic fine powders such as titanium oxide, calcium carbonate, silicon dioxide (silica), and aluminum oxide.
Further, the first diffusion layer 33 is formed by sticking a diffusion sheet in which a diffusing agent 33a is dispersed in an ultraviolet curable resin to the translucent resin substrate 32, and irradiating ultraviolet rays from the upper part of the protective film to cure the ultraviolet curable resin. Then, it can be formed by a diffusion transfer method in which the protective film is peeled off.
Compared with the conventional multilayer extrusion sheet method, the diffusion transfer method has the advantage that production efficiency is high because it can cope with a wide variety of small-scale production and the production cost is low.

The lenticular lens sheet 20 has a lenticular lens layer 29 in which a plurality of vertically long convex lenses 21 having an action of refracting and diffusing image light in the horizontal direction are arranged on a base material 22 as shown in FIG. A light shielding layer 23, an adhesive layer 24, a second diffusion layer 25, and a third diffusion layer 26. The substrate 22 of the lenticular lens sheet 20 is not particularly limited, but a film substrate made of a polyester resin is preferably used.
A method of forming the convex lens 21 on the base material 22 of the lenticular lens layer 29 is not particularly limited, but a lens portion made of a cured product using an ultraviolet curable resin or an electron beam curable resin. Is preferably used from the standpoints of productivity and lens molding accuracy.

  The ultraviolet curable resin or electron beam curable resin is not particularly limited, but urethane acrylate and epoxy acrylate resins are preferable. The convex lens 21 made of a cured product of an ultraviolet curable resin or an electron beam curable resin, for example, applies the resin composition to a molding surface of an embossing roll mold having an inverted shape of the lens, and embosses the film substrate. It can be formed by a method such as supplying to a roll mold and curing the resin by irradiating ultraviolet rays or ionizing radiation through the base material and at the same time polymerizing and bonding the lens part made of the resin-cured molding to the base material. .

The light shielding layer 23 is formed in parallel in a stripe shape on the light emission surface, which is a flat surface of the base material 22 of the lenticular lens layer 29. The light shielding layer 23 is formed in a non-condensing portion region (region where image light is not transmitted) on the light exit surface of the base material 22.
The second diffusion layer 25 is attached to the light emission surface of the base material 22 of the lenticular lens layer 29 via an adhesive layer 24, and a diffusion agent 25a is dispersed on a translucent substrate. As the diffusing agent 25a, the same material as 33a can be used.

The third diffusion layer 26 is attached to the light emission side of the second diffusion layer 25, and a diffusing agent 26a is dispersed in a transparent resin-made transparent substrate.
Similarly to the first diffusion layer 33, the third diffusion layer 26 can be formed on the second diffusion layer 25 by using a diffusion transfer method.
As the diffusing agent 26a, the same diffusing agent 33a can be used.
The diffusivity of the diffusing agent is such that the diffusivity of the second diffusion layer 25 is lower than the diffusivity of the first diffusion layer 33 and the diffusivity of the third diffusion layer 26 is higher than the diffusivity of the first diffusion layer 33. The degree of refraction is controlled by using a diffusing agent having a difference in concentration depending on the amount of dispersion or a refractive index.
By making the degree of diffusion of the second diffusion layer 25 lower than the degree of diffusion of the third diffusion layer 26, the intensity of scintillation and the like is achieved by diffusing light while preventing unnecessary reduction in contrast. Can be reduced.

Such a lenticular lens sheet 20 is manufactured as follows.
First, the convex lens 21 is formed on the base material 22 of the lenticular lens layer 29.
Next, an adhesive ultraviolet curable resin layer is formed on the light exit surface of the base material 22 of the lenticular lens layer 29. The ultraviolet curable resin layer is irradiated with ultraviolet rays vertically through the respective convex lenses 21 to cure the portion of the ultraviolet curable resin layer condensed by the convex lenses 21 and to remove the ultraviolet curable resin layer. Adhesive. Thereafter, a black colorant is attached only to the uncured portion of the adhesive UV curable resin layer to form a light shielding layer. The black fine powder toner as a colorant can be selectively attached only to the uncured portion. Moreover, the transfer paper provided with the black ink layer can be used to selectively adhere the black ink layer only to the uncured portion.

According to the above exposure process, each convex lens is collectively irradiated with parallel light from the lens side to the entire surface of the lenticular lens sheet. Therefore, the light-shielding layer to be formed is for a non-condensing portion by irradiation of ultraviolet rays to an actual lenticular lens sheet, and in a place where the light-shielding layer needs to be truly formed, that is, in a region where image light does not pass, It can be formed with certain positional accuracy.
Thereafter, the pressure-sensitive adhesive layer 24 is pasted on the light shielding layer 23.
Next, the dispersing agent 25 a is dispersed in the translucent resin, and the second diffusion layer 25 integrated by melt extrusion molding is attached onto the pressure-sensitive adhesive layer 24.
Thus, the lenticular lens sheet 20 is completed.

The transmission screen according to the present embodiment includes a first diffusing layer 33 having a fine concavo-convex shape 33b on the incident light side surface of the Fresnel lens sheet 10 and a diffusing agent 33a dispersed therein. Since the second diffusion layer 25 in which the agent 25a is dispersed and the third diffusion layer 26 in which the diffusion agent 26a is dispersed is provided and has three diffusion layers, the transmitted light can be sufficiently diffused. it can.
In addition, the second diffusion layer 25 is less likely to impede light transmission because the amount of dispersion of the diffusing agent is small compared to the first diffusion layer 33 and the third diffusion layer, and the incident light is sufficiently stepwise. Since it is diffused, it is possible to reduce scintillation while preventing unnecessary reduction in contrast.

The layer thickness of the third diffusion layer 26 is preferably the same as or greater than the layer thickness of the first diffusion layer 33, and the layer thickness of the second diffusion layer 25 is the third diffusion layer 26. It is preferable that it is thicker than the layer thickness.
Further, the scintillation can be reduced as the distance between the lenticular lens layer 29 and the third diffusion layer 26 is increased. However, the scintillation is reduced as the distance is increased, but the contrast is lowered contrary to that.
Therefore, the layer thickness of the second diffusion layer 25 that determines the distance between the lenticular lens layer 29 and the third diffusion layer 26 is set in consideration of a decrease in contrast in exchange for a reduction in scintillation.

(Second Embodiment)
FIG. 2 is a sectional view showing a second embodiment of the transmission screen of the present invention.
In addition, about the member similar to the said 1st Embodiment, the same code | symbol is used and description is abbreviate | omitted.
The Fresnel lens sheet 30 of this embodiment includes the same Fresnel lens sheet 31 as that of the above-described embodiment, a translucent substrate 32, and a first diffusion layer 33.
The lenticular lens sheet 40 of the present embodiment includes a lenticular lens layer 29, a light shielding layer 23, a pressure-sensitive adhesive layer 24, a second diffusion layer 25, a third diffusion layer 26, and a translucent layer similar to those of the above-described embodiment. Resin substrates 27 and 28 are provided.
The second diffusion layer 25 has a configuration in which a diffusing agent 25a is dispersed in a resin-made translucent substrate. The second diffusing layer 25 is disposed to face the adhesive layer 24 with the translucent substrate 27 interposed therebetween. Thus, the third diffusion layer 26 is disposed to face the second diffusion layer 25 with the translucent substrate 28 interposed therebetween.

In addition, this invention is not limited to the above embodiment.
For example, the observer-side surface of the third diffusion layer of the lenticular lens sheet may be subjected to at least one surface treatment selected from hard coat treatment, antistatic treatment, and antireflection treatment.

(A) is the perspective view which showed 1st Embodiment of the structure of the transmission type screen of this invention. (B) is sectional drawing which showed 1st Embodiment of the structure of the lenticular lens sheet used for the transmission type screen of this invention. It is sectional drawing which showed 2nd Embodiment of the structure of the lenticular lens sheet used for the transmission type screen of this invention.

Explanation of symbols

10..Transmissive screen 20, 40..Lenticular lens sheet 21..Convex lens 22..Base material 23..Light shielding layer 24..Adhesive layer 25..Second diffusion layers 25a, 26a, 33a.Diffusion Agent 26 ·· Third diffusion layers 27, 28 and 32 · · Translucent substrate 29 · · Lenticular lens layer 30 · · Fresnel lens sheet 31 · · Fresnel lens layer 33 · · First diffusion layer 33b · Fine uneven shape

Claims (4)

In a transmission screen that combines at least a Fresnel lens sheet and a lenticular lens sheet,
The Fresnel lens sheet is
A Fresnel lens layer,
A first diffusion layer in which a diffusion material disposed opposite to the Fresnel lens layer and a translucent substrate is dispersed,
The lenticular lens sheet is
A lenticular lens layer,
A second diffusion layer in which a diffusion material is dispersed;
A third diffusion layer;
The third diffusion layer is disposed opposite to the lenticular lens layer via the second diffusion layer ,
And
The diffusivity of the first diffusion layer;
The degree of diffusion of the second diffusion layer;
What is the degree of diffusion of the third diffusion layer?
Third diffusion layer> First diffusion layer> Second diffusion layer
Have the relationship
The thickness of each layer is
Second diffusion layer> third diffusion layer ≧ first diffusion layer
Having a relationship
A transmissive screen characterized by The transmission screen according to claim 1.
The surface of the first diffusion layer on the light source side has a fine uneven shape;
A transmissive screen characterized by The transmission screen according to any one of claims 1 to 2,
The second diffusion layer is formed by dispersing a diffusing agent on a translucent substrate by melt extrusion molding;
A transmissive screen characterized by The transmission screen according to any one of claims 1 to 3,
A transmission type screen characterized in that at least one kind of surface treatment selected from hard coat treatment, antistatic treatment, and antireflection treatment is applied to the surface of the third diffusion layer on the viewer side.

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