JP3268204B2 - Lenticular sheet for transmission screen and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lenticular sheet constituting a transmissive screen used in a liquid crystal projection television in combination with a Fresnel lens sheet, and more particularly to a simple structure having a lens portion formed on only one side. , A lens portion formed by juxtaposing convex cylindrical lenses (semi-cylindrical convex lenses) can have a fine pitch (miniaturization) and a stripe shape formed at a position corresponding to a non-light-collecting portion of each cylindrical lens. A lenticular sheet and a method for manufacturing the same, wherein a light-shielding pattern (black stripe; hereinafter, referred to as BS) can be accurately formed at a desired portion.

[0002]

2. Description of the Related Art A transmission screen generally comprises a combination of a Fresnel lens sheet and a lenticular sheet. As shown in FIG. 4, the lenticular sheet has a convex cylindrical lens surface formed on both surfaces and a single surface (for image light). In general, a projection is formed at the boundary between the cylindrical lenses on the emission side, and a light-shielding layer (a black stripe having light absorbency) is formed on the projection.

A convex cylindrical lens surface is formed on the front and back of a CRT having a three-tube projector (light source).
This is because in the case of the system, it is necessary to correct the deviation of the three colors by the lens on the incident side.

In recent years, liquid crystal projection televisions have become widespread, and a transmission screen for observing the image has been demanded. The liquid crystal projection television has a structure as shown in FIG. 3, in which image light from a projector (light source) is projected onto a transmission screen via a mirror, and an observer views the projected image through the screen.

Since the number of pixels of the liquid crystal projector has been increased (from the conventional hundreds of thousands of pixels to more than one million pixels) with the increase in definition of the image quality, the fine pitch of the cylindrical lens can be adjusted even for a lenticular sheet. Is required. The fine pitch reduces moire phenomenon caused by the periodicity of the pixels of the liquid crystal projector and the periodicity of the cylindrical lens.
Specifically, a fine pitch of 0.3 mm or less is demanded from the current 0.7 mm.

The lenticular sheet is currently obtained by press-molding a transparent thermoplastic resin sheet or by performing double-side molding simultaneously with melt extrusion. According to the method, it is very difficult to make the above fine pitch. The reason for this is that the temperature is non-uniform at the time of cooling after thermoforming, and the molded product is warped or the heat shrinkage is non-uniform.

As a manufacturing method suitable for molding a fine pitch lens sheet, various molding methods using a radiation (ultraviolet ray or electron beam) curable resin are known.
The proposals exemplified below are representative.

[0008] An ultraviolet curable resin is injected into a gap between a Fresnel mold and a transparent resin plate, and is irradiated with ultraviolet rays to polymerize and bond the transparent resin plate to the transparent resin plate. And a UV curable resin having a Fresnel lens surface on the anti-transparent resin plate side (and a method for producing the same).

[0009] After applying an ultraviolet (electron beam) curable resin to a Fresnel mold, the resin is laminated while defoaming a film.
After molding by irradiation with ultraviolet rays (electron beams), the film (and resin) is released, and then integrated with the transparent substrate.

Ultraviolet light (electron beam) represented by the above proposal
Most molding methods using a curable resin aim at manufacturing a Fresnel lens sheet having a complicated shape as compared with lenticular, and no proposal has been made on a fine pitch lenticular sheet for a transmission screen. is the current situation.

[0011] When a lenticular sheet molded by various techniques is used as a screen, a BS is conventionally formed to improve contrast. Various printing methods such as offset, gravure, and screen are commonly used as a method for forming the BS. However, in the printing method, a printing plate having high positional accuracy such that an image portion becomes a light absorbing portion is produced. When the cylindrical lens has a fine pitch or the lenticular sheet has a large size, it becomes more difficult to manufacture and register (position) a printing plate. As a method of forming a light-shielding pattern other than the normal printing method, the following methods are known.

JP, 56-38035, A A light absorption layer is formed in "the surface of a crevice or a convex part" other than a field including a condensing part of a lenticular board.

The lenticular surface is extruded, and at the same time, a light absorbing layer is formed on a portion other than the lenticular light collecting portion by heat laminating the ink using an ink application roll. The ink application roll is installed immediately after the molding die roll on the lenticular surface, and a ridge is provided at a position corresponding to a portion other than the lenticular light collecting portion. The light-absorbing layer is formed while supplying an ink containing a light-absorbing agent to the transparent substrate (lenticular plate) and a resin as a binder. In order to form a light absorbing layer in a desired portion, registration of an ink application roll is performed with respect to a lenticular mold roll.

[0014] In the above, since the portion on which the light absorbing layer is formed needs the “surface of the concave portion or the convex portion” formed on the flat surface of the lenticular plate, the shape of the lens sheet becomes complicated and molding is difficult. In addition to the difficulty, there is a problem that the strength of the lens sheet (the portion corresponding to the valley of the lenticular surface becomes thinner when the concave portion is deepened) is reduced.

The above method is similar to the ordinary printing method,
It is necessary to produce a printing plate (ink application roll) with high positional accuracy. The light-shielding pattern depends on the image portion of the printing plate (the ridge portion of the ink application roll). Depends on plate accuracy and printing alignment. Further, in the above-described apparatus, it is difficult to form the BS only at the same position for each cylindrical lens (the same non-light-collecting portion in all the cylindrical lenses). Therefore, it is necessary to form a light shielding pattern at a different position for each cylindrical lens (for example, when the lenticular plate is large and the observation optical path is different between the central cylindrical lens and the end cylindrical lens). It is difficult to respond.

In addition, as a method for forming a BS with a reliable positional accuracy on the back surface of a lens sheet without the need for a printing plate, even if the lens sheet does not require the uneven portion on which the BS is formed, the following method is used. Is known.

JP, 59-121033, A A positive type photosensitive adhesive (an adhesive whose adhesiveness is lost by exposure to light) is provided on the observation surface side of a transmission type screen (lens sheet). After exposing the adhesive with light rays projected from a projection light source (projector) or a light source having an opening equivalent thereto from the surface opposite to the surface, and after removing the adhesiveness of the light-collecting portion of each unit lens of the lens sheet, The wet process is performed by spraying light-shielding toner from the observation surface, sticking it to the unexposed portion where the adhesive remains, and removing the toner that has just adhered to the portion that has become non-sticky by exposure and excess toner. A method of easily and inexpensively obtaining a transmissive projection screen on which a BS having excellent light-shielding properties is formed without need.

[0018]

The present invention has a structure in which a BS corresponding to a non-light-collecting portion of a lens portion is formed via a diffusion layer formed on an anti-lens surface (flat surface). It is an object of the present invention to provide a lenticular sheet suitable for a high-definition and high-quality liquid crystal projection television and having a high contrast of an observed image.

[0019]

According to a first aspect of the present invention, a convex lenticular lens is provided in a lenticular sheet which constitutes a transmission type screen in combination with a Fresnel lens sheet. A radiation-curable resin in which an inorganic compound powder is dispersed and mixed is provided on the flat surface of a lenticular sheet having a lens portion and having a flat surface on the opposite side.
A photosensitive diffusion layer made of a fat is formed on the entire surface, and a stripe-shaped light shielding pattern is formed on the photosensitive diffusion layer at a position corresponding to a non-light-collecting portion of each cylindrical lens.
It also has a function to protect the lens from the effects of ultraviolet rays.
A lenticular sheet for a transmission screen having a configuration in which a protective layer is provided.

According to a second aspect of the present invention, there is provided a lenticular sheet which constitutes a transmission type screen in combination with a Fresnel lens sheet, wherein a cured material of a radiation-curable resin is provided on one surface of a transparent support. , convex cylindrical lenses are lens portion is formed comprising juxtaposed in the following pitch 0.3 mm, the flat surface of the opposite side of the support is, no
From radiation curable resin in which organic compound powder is dispersed and mixed.
A photosensitive diffusion layer is formed on the entire surface, and a stripe-shaped light-shielding pattern is formed on the photosensitive diffusion layer at a position corresponding to a non-light-collecting portion of each cylindrical lens .
Protection that protects the lens from the effects of ultraviolet light
This is a lenticular sheet for a transmission type screen having a layer.

According to a third aspect of the present invention, the light-shielding pattern is a positive photosensitive adhesive in which inorganic compound powder is dispersed and mixed.
請 characterized in that it consists of a black transfer layer formed on the adhesive portion is a non-condensing portions of the photosensitive diffusion layer consisting of material
A lenticular sheet for a transmission screen according to claim 1 or 2 .

According to a fourth aspect of the present invention, there is provided the transmission type screen according to any one of the first to third aspects, wherein a film having an antistatic function is further laminated on the outermost surface opposite to the lens portion. Wrench sheet for the

According to a fifth aspect of the present invention, there is provided a transmission type screen according to any one of the first to fourth aspects, wherein a film having an antireflection function is further laminated on the outermost surface on the opposite side of the lens portion. Wrench sheet for the

According to a sixth aspect of the present invention, there is provided a method for producing a lenticular sheet according to the first or second aspect, comprising the following steps. A radiation curable resin in which an inorganic compound powder is dispersed and mixed is applied to the entire flat surface of a lenticular sheet having a lens portion in which convex cylindrical lenses are juxtaposed and the opposite side being a flat surface. Then, irradiate radiation from the cylindrical lens side,
A step of curing the radiation-curable resin in a portion condensed by a lens and coloring the resin surface other than the cured portion black.

[0025]

[Function] By forming a light-shielding pattern (black stripe) on the diffusion layer and directly facing the observer,
The contrast of the viewed image is improved.

By forming the lens portion with a cured product of a radiation (ultraviolet ray, electron beam) curable resin, it is possible to make a fine pitch which cannot be realized with a thermoplastic resin, and a fine pitch up to a minimum pitch of 50 μm. Lenticular sheet can be produced. (Claim 2)

By using a radiation-curable resin in which inorganic compound powder is dispersed and mixed as the diffusion layer, the layer structure on the flat surface is simplified, and the lenticular sheet can be made thinner.

A film having an antistatic function or an antireflection function is laminated on the outermost surface on the opposite side of the lens portion, so that the screen function is improved when the lenticular sheet is used and the BS is protected. Will be fulfilled. The role of the latter is roughly classified into physical protection against scratching and friction during use, and chemical protection against moisture, chemicals, ultraviolet rays from external light, and the like. (Claims 4 and 5 )

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. First, in the following (A), other than the present invention
An embodiment will be described. (A) When the diffusion layer is not a radiation-curable resin (see FIG. 1) An inorganic compound such as TiO2, SiO2 is dispersed and mixed in a binder (transparent resin) to form a coating, which is then formed into a transparent material such as polyester, polycarbonate or acrylic. It is applied to a film having good properties (light transmittance of 80% or more) to form a diffusion film. The above film is laminated on a flat surface of a lenticular sheet 10 made of a transparent resin such as PVC, acrylic, polycarbonate, polystyrene, etc.
20. Alternatively, the above-mentioned coating material may be directly applied to the flat surface of the lenticular sheet without being applied to the film to form a diffusion layer. (Fig. 1 (a))

A method of forming a light-shielding pattern at a position corresponding to the boundary of a fine-pitch cylindrical lens has been proposed in the aforementioned Japanese Patent Application Laid-Open No. 59-121033. Also in the present invention, a light-shielding pattern is formed on a flat surface of a lenticular sheet using the above-mentioned proposed method.

As the photosensitive resin, it is preferable that the exposed portion becomes non-tacky due to the reaction, and the unexposed portion exhibits a tacky property. Among various ultraviolet photopolymers that are sensitive to ultraviolet light, a chromin film (trade name; manufactured by DuPont) is remarkably exhibiting the above characteristics, and thus is suitable for use in forming a light-shielding pattern (black stripe).

On the diffusion layer 20 formed on the flat surface of the lenticular sheet, a photosensitive resin (chromin film) 30
To form a laminate. (FIG. 1 (b)) Next, by irradiating ultraviolet rays from an ultraviolet irradiating device (not shown), a light condensing unit based on the condensing action of the lenticular lens
After a non-adhesive portion / adhesive portion corresponding to the non-light-collecting portion is formed on the photosensitive resin (chrominary film) 30, the paper is passed through a pair of laminating rolls (not shown) so that the transfer paper ( (Not shown), the black transfer layer is transferred only to the adhesive portion, and the light-shielding pattern (black stripe) 40
To form In the drawing, the light-collecting portion serving as the non-adhesive portion is shaded, and the non-light-collecting portion serving as the adhesive portion is represented by a white portion, but in both cases, the transparency and light transmittance of the photosensitive resin 30 change. I do not. (Fig. 1 (c)-(d))

Ultraviolet rays reach the photosensitive resin 30 even through the diffusion layer 20, but as the exposure amount (exposure intensity × exposure time) increases, the photosensitive portion (cured portion) spreads from the converging portion. The adhesive portion (line width of the light-shielding pattern) can be adjusted.

For the pressure transfer of the light-shielding pattern, for example, a chrominance ink foil (trade name, manufactured by DuPont) or the like is used.

Note that various changes exemplified below may be added to the above embodiment .

The photosensitive resin layer 30 is formed by coating and forming a liquid positive type ultraviolet photosensitive resin instead of laminating the chrominary film.

Instead of transferring the black transfer layer, a light-shielding pattern is formed by adhering black powder toner only to the adhesive portion.

As the lenticular sheet, a lens in which convex cylindrical lenses are juxtaposed and formed on one surface of a transparent support with a cured product of a radiation-curable resin is used. In this case, it is more suitable for achieving a fine pitch of the cylindrical lens than a lens sheet formed by molding a thermoplastic resin, and the lens pitch is preferably 0.3 mm or less.

A protective layer 50 is formed on the outermost surface on the opposite side of the lens portion. In particular, when the lens portion is formed of a cured product of a radiation-curable resin, when the screen is used,
The problem of weather resistance such as the yellowing of the lens portion due to the influence of ultraviolet light included in external light is remarkable.
And a film of vinylidene fluoride, PMMA or the like. In order to improve the screen function, the protective layer 50 may be provided with an anti-reflection function by, for example, applying a matte treatment (fine irregularities) on the surface so as to irregularly reflect external light, or an acrylic resin serving as a base of the protective layer. Such as adding silica or the like, or forming a multilayer film having a change in the refractive index by vapor deposition. To have an antistatic function,
There is a treatment such as coating a surfactant on the surface of the protective layer. In order to improve the contrast, a transparent film (smoke film) colored dark may be used. In any case, a film-like protective layer having a thickness of 1 mm or less is sufficient. However, if the protective layer is a thick and rigid sheet-like protective layer, the protective layer functions as a support base for the lenticular sheet, and the projection television It is also easy to attach to the device. (Figure e))

(B) When the Diffusion Layer is a Radiation Curable Resin (See FIG. 2) The above (A) is a description of the case where the diffusion layer 20 and the photosensitive resin layer 30 have different layer configurations. However, according to the present invention, by providing the photosensitive resin with a diffusion function, it is possible to form both layers into the same layer.

There are various types of photopolymers (photosensitive resins), but generally have an acroyl group in the molecule, and include epoxy acrylates, urethane acrylates, polyester acrylates, polyol acrylates and the like. And a methacrylic monomer having a monofunctional group, a bifunctional group, and a polyfunctional group; and a mixture of a polymer and an ogomer such as tetrahydrofurfuryl acrylate, polyethylene glycol diacrylate, and trimethylolpropane triacrylate.

Using the above photopolymer as a binder,
An inorganic compound powder such as TiO2, SiO2, CaCO3, Al2O3 is dispersed and mixed as a diffusing agent to form a paint. In addition, additives such as a photopolymerization initiator, a surfactant, and an antifoaming agent may be added as necessary.

The above coating material is applied to the flat surface of the lenticular sheet 10 to form a photosensitive diffusion layer 25 (FIG. 2A).
), The same operation as in the above (A) is performed to form a light shielding pattern (black stripe) 40. (Fig. 2 (b)
)

[0044]

According to the present invention, a lenticular sheet suitable for observation of a high-definition and high-quality liquid crystal projection television is provided. The lenticular sheet is effective in the points listed below. (1) Since the light-shielding pattern (BS) is formed on the diffusion layer and directly faces the observer, the contrast of the image to be viewed is improved. (2) Fine pitch (fine) light-shielding patterns can be formed with high precision corresponding to cylindrical lenses. (3) By forming the lens portion with a cured product of a radiation (ultraviolet ray, electron beam) curable resin, a fine pitch which cannot be realized with a thermoplastic resin can be obtained. (4) By using a radiation-curable resin in which inorganic compound powder is dispersed and mixed as the diffusion layer, the layer configuration on the flat surface is simplified, and the lenticular sheet can be made thinner.

[0045]

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a manufacturing process of a lenticular sheet.

FIG. 2 is an explanatory view showing a manufacturing process of a lenticular sheet according to the present invention.

FIG. 3 is an explanatory diagram illustrating an example of the structure of a liquid crystal projection television.

FIG. 4 is an explanatory view showing a conventional lenticular sheet for a transmission screen.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Lenticular sheet 20 ... Diffusion layer 25 ... Photosensitive diffusion layer 30 ... Photosensitive resin layer 40 ... Light shielding pattern 50 ... Protective layer

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-127401 (JP, A) JP-A-3-64701 (JP, A) JP-A-59-121033 (JP, A) JP-A-4- 340534 (JP, A) JP-A-3-220542 (JP, A)

Claims (6)

(57) [Claims] 1. A lenticular sheet comprising a transmissive screen in combination with a Fresnel lens sheet, comprising a lens portion in which convex cylindrical lenses are juxtaposed, and having a flat surface on the opposite side. A radiation hardening material in which an inorganic compound powder is dispersed and mixed on the flat surface of the sheet;
A photosensitive diffusion layer made of a curable resin is formed on the entire surface, and a stripe-shaped light-shielding pattern is formed on the photosensitive diffusion layer at a position corresponding to a non-light-collecting portion of each cylindrical lens . Has a function to protect the lens from the effects of ultraviolet rays
Lenticular sheet for a transmission screen having a protective layer provided. 2. A lenticular sheet which constitutes a transmission screen in combination with a Fresnel lens sheet, wherein a convex cylindrical lens is formed on one surface of a transparent support by a cured product of a radiation-curable resin. A lens portion arranged in parallel with a pitch of 3 mm or less is formed, and an inorganic compound powder is dispersed and mixed on the flat surface on the opposite side of the support.
A photosensitive diffusion layer made of a radiation-curable resin is formed on the entire surface, and a stripe-shaped light-shielding pattern is formed on the photosensitive diffusion layer at a position corresponding to a non-light-collecting portion of each cylindrical lens. And a function to protect the lens from the effects of ultraviolet rays.
Lenticular sheet for a transmission screen having a protective layer provided. 3. A light-shielding pattern comprising an inorganic compound powder dispersed and mixed.
3. The transmission according to claim 1 , further comprising a black transfer layer formed on an adhesive portion that is a non-light-collecting portion with respect to the photosensitive diffusion layer made of the combined positive photosensitive adhesive. Lenticular sheet for mold screen. The outermost surface of the opposite side of 4. A lens unit is configured such that the film was further laminated with an antistatic function according
Item 5. A lenticular sheet for a transmission screen according to any one of Items 1 to 3 . The outermost surface of the opposite side of the 5. A lens unit is configured such that the film was further laminated with an antireflection function according
Item 5. A lenticular sheet for a transmission screen according to any one of Items 1 to 4 . 6. A method comprising the following steps :
3. The method for producing a lenticular sheet according to 1 or 2 .
A radiation curable resin in which inorganic compound powders are dispersed and mixed is applied to the entire surface of a lenticular sheet having a lens portion in which convex cylindrical lenses are juxtaposed and a flat surface on the opposite side. Irradiating radiation from the side of the cylindrical lens to cure the radiation-curable resin in a portion condensed by the lens, and coloring the surface of the resin other than the cured portion black.