JPH0216497B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a transmissive black stripe screen that is effective for improving the contrast of a large television screen.

(Prior art) Conventionally, this type of screen has been designed to improve contrast by using a screen with a rough surface on the input side of the projected image, and an anti-reflection treatment applied to the screen surface on the exit side of the projected image, that is, the viewing side. Measures have been taken to prevent room illumination light from being reflected on the screen surface and reducing the contrast of the projected image, such as by making the screen material itself slightly absorbent. However, applying a good anti-reflection finish to the screen surface complicates the process and increases costs, and providing the screen material itself with light absorption properties also reduces the amount of transmitted light of the projected image. There were flaws.

As a method to eliminate these drawbacks, a lenticular sheet made of transparent synthetic resin with the light refraction directions perpendicular to each other is provided on both sides, and by limiting the light dispersion angle in the horizontal and vertical directions of projection, the contrast can be improved. An improved screen has been proposed.

This method gives directionality to the light emitted from the screen, allowing more of the projected image's light intensity to enter the viewer's eyes, thereby increasing the ratio to the constant light level of room light and improving contrast. However, it is difficult to obtain sufficient contrast in that the indoor light reflected by the screen surface still enters the viewer's eyes.

Furthermore, Japanese Patent Laid-Open No. 56-38035 discloses a method that can eliminate the above-mentioned drawbacks by providing a light absorption layer only on the projection image exit surface of a screen made of a lenticular sheet, excluding the light transmitting portion. has been done.

(Problems to be Solved by the Invention) In the device disclosed in Japanese Patent Application Laid-Open No. 56-38035, a light absorption layer is formed on the surface of the concave portion or convex portion other than the region including the light condensing portion.

However, when forming the light absorption layer on a convex part, the projected light diverges from the surface of the condensing part, so if the convex part is formed high, the optical path of the projected light can be blocked. There is a disadvantage that the more the convex portion is formed, the wider the width of the convex portion, that is, the width of the light absorbing portion, cannot be increased, and the contrast cannot be obtained sufficiently.

In addition, when forming a light absorption layer in a recess, if the recess is formed deep in order to increase the concentration of the light absorption layer, the portion corresponding to the valley of the lenticular lens will be thinned, so the thickness of the sheet will be reduced. Strength is extremely reduced. Therefore, the present invention makes it possible to easily produce a high-precision screen with good contrast and strong sheet strength for large-sized televisions by thermally laminating the light absorption layer for blackstrive with registration during the molding process. Moreover, the purpose is to be able to manufacture it at low cost.

(Means for Solving the Problems) In order to achieve the above objects, the present invention provides the following method for manufacturing a transmission screen.

In other words, in manufacturing a transmission screen in which a lenticular surface is formed on one side of a transparent substrate and a light absorption layer is provided on the other side in areas other than the lenticular light condensing part, a lenticular mold is used to hold the extruded transparent resin facing. At the same time as the transparent substrate is formed by being guided between the roll and the pressure roll, the ink coating is installed immediately after the lenticular mold roll and has protrusions at positions corresponding to areas other than the light condensing part. While supplying an ink containing a light absorbing agent to the ridges of the roll and using a resin as a binder that can be thermally laminated to the transparent substrate, the ink is thermally laminated to a portion of the transparent substrate other than the lenticular light condensing portion. This is a method of manufacturing a transmission screen characterized by forming a light absorption layer.

(Function) The present invention provides a light-absorbing layer on the back surface of a lenticular sheet, or a screen made of a Fresnel lens and a lenticular sheet, during molding. A method for easily manufacturing a screen provided with a light absorbing layer that does not cause misalignment between the light absorbing layer and the light condensing part position of a lenticular sheet due to expansion and contraction caused by changes in temperature, humidity, molding conditions, etc. It is.

(Example) This will be explained below based on the drawings.

First, the structure of the screen of the present invention will be explained with reference to FIG. 1. Reference numeral 1 is a light source, 2 is a Fresnel lens sheet for making the light rays from the light source 1 parallel, and 3 is the lens surface thereof. 4 is a lenticular sheet for widening the viewing angle,
The lens surface 5 faces the Fresnel lens sheet 2, and a light absorption layer 8 is formed in register at a position on the back surface 7 corresponding to the non-light transmitting portion 6 of the concave portion of the lens surface 5. ing.

The reason why the contrast increases in a screen with such a configuration is that the transmitted light brightness of the maximum part of the image projected from the screen is Tmax, the transmitted light brightness of the minimum part is Tmin, and the reflection of the screen without a light absorption layer is Let R be the light intensity, R′ be the reflection intensity of the screen with a light absorption layer, and let C and C′ be the respective contrasts of the normal screen and the screen with the light absorption layer, then C=Tmax+R/Tmin+R C′=Tmax+R′ /Tmin+
R′. Here, since Tmax>Tmin and R>R', C-C'=(Tmax-Tmin)(R-R')/(Tmin+R)(
Tmin+R')<0, and the contrast is greater in a screen with a light absorption layer.

Next, the manufacturing method of the present invention will be explained.

In FIG. 2, reference numeral 9 denotes a T-die for extruding a transparent substrate or a translucent substrate material 10 kneaded with a light diffusing agent into a sheet. 12
However, ink application rolls 13 are provided opposite each other at the bottom, and a rubber roll 16 that receives and applies ink from an ink pan 14 at an ink supply roll 15 is in contact with the ink application rolls 13.

As shown in FIG. 3, this lenticular mold 11 has a mold surface opposite to the lenticular surface, and the ink applicator roll 13 is placed on a disk at a position corresponding to the protrusion 17 of the lenticular mold 11. Ink is applied to the circumferential surface of the disc 18 by a rubber roll 16.

The transparent or translucent substrate 10 extruded from the T-die 9 by the device configured as above is made of a material of the lenticular sheet, and is made of transparent resin such as vinyl chloride, acrylic, polycarbonate, polystyrene, polyester, etc. or a translucent resin mixed with a light diffusing agent such as glass beads, silica, or talc, and this material 10 is pressed between a lenticular mold roll 11 and a press roll 12 to form a lenticular surface. It is formed as a light absorption layer 8 between the lenticular mold roll 11 and the disc 18 of the ink application roll 13 at a position on the back surface 7 corresponding to the non-light transmitting portion 6 of the concave portion of the lens surface 5. . The ink used here uses a resin that can be thermally laminated with the lenticular sheet material 10 as a binder, such as vinyl chloride, acrylic, urethane, polyamide, etc., and a light absorbing agent such as metal powder, carbon, etc. is dissolved in a solvent. , or in a hot molten state. The ink application roll 13 is movable in the axial direction with respect to the lenticular mold roll 11 so that registration can be performed during the application of the ink.

The applied ink is thermally laminated during the subsequent lenticular lens molding process, thereby forming a light absorption layer 8 on the back surface of the non-light transmitting portion of the lenticular lens.

(Effect of the invention) (a) The present invention has the following effects.

In the present invention, when molding a lenticular lens using a mold, an ink containing a light absorbing agent and a resin binder that can be thermally laminated with the lens body is applied to the back surface of the non-light transmitting part of the lens. Since we have adopted a method of forming a light absorbing layer by coating with the protrusions of the ink, registration during ink application can be achieved by a slight movement of the coating mold in the lateral direction relative to the lenticular mold. Since the coating is applied at a point when there is no change in the dimensions of the yular lens, it is simpler than the conventional method of applying a light absorption layer by printing etc. after lens molding, and the finished product has fewer errors. It is.

(b) The light absorption layer of the present invention is not formed by forming a convex portion on the back surface of the lenticular sheet, so it cannot prevent the optical path of the projection light.
In addition, since the width of the light-absorbing part can be widened, a screen with good contrast can be obtained.Also, since the light-absorbing layer is not formed by forming a concave part on the back of the lenticular sheet, it is possible to obtain a screen with good contrast. The portions corresponding to the valleys of the lens are not made thinner, and therefore the strength of the sheet is not reduced.

(c) Since the soft resin is laminated with a light-absorbing substance embedded in it, there is no need to use a large amount of binder to disperse the light-absorbing substance, as is the case with printing methods, and sufficient density can be obtained even with a thin light-absorbing layer. Not only is it possible to do this, but also the adhesive strength of the light absorption layer can be made higher than that of the printing method.

(d) It is preferable not to use a solvent when forming the light-absorbing layer because it prevents the occurrence of micro-cracks even when an acrylic agent is used as a transparent substrate; It does not deteriorate, and in the conventional method of applying ink to form a light absorption layer, molding and formation of the light absorption layer were performed as separate processes. However, in the present invention, the light absorption layer is applied immediately after molding. This problem can be solved and screens can be produced efficiently.

In any case, the present invention allows for highly accurate registration due to the combination of effects (a) and (b) to (d), and even without forming a convex portion on the back surface of the lenticular sheet.
Another feature is that a light absorption layer can be formed with high precision without forming deep recesses. The reason why the recesses do not have to be deep is that a large amount of binder is not required, and since a solvent is not necessarily required, a highly concentrated light absorption layer can be obtained with a thin film. .

From the above, the present invention enables the production of a high-precision black stripe screen with good contrast for large-sized televisions at low cost.

[Brief explanation of drawings]

FIG. 1 is an explanatory drawing of a screen structure manufactured by the method of the present invention, FIG. 2 is a side view schematically showing an apparatus for carrying out the method of the present invention, and FIG. 3 is a diagram showing a schematic diagram of an apparatus used in the method of the present invention. FIG. 3 is a front view of a lenticular mold roll and an ink application roll. DESCRIPTION OF SYMBOLS 1... Light source, 2... Fresnel lens sheet, 4... Lenticular sheet, 6... Non-light transmitting part of a recessed part,
8... Light absorption layer, 9... T-die, 10... Lenticular lens material, 11... Lenticular mold roll, 12... Ink coating roll.

Claims (1)

[Claims] 1. In manufacturing a transmission screen in which a lenticular surface is formed on one side of a transparent substrate and a light absorption layer is provided on the other side of the lenticular light-condensing area, a lenticular mold roll that faces the extruded transparent resin is used. and a pressure roll to mold the transparent substrate, and at the same time, the ink application roll is installed immediately after the lenticular mold roll and has protrusions at positions corresponding to areas other than the light condensing part. While supplying an ink containing a light absorbing agent to the ridges of the transparent substrate and using a resin as a binder that can be thermally laminated to the transparent substrate, the ink is thermally laminated to parts of the transparent substrate other than the lenticular light condensing part to generate light. A method for producing a transmission screen, which comprises forming an absorbing layer.