JP3227807B2 - Method for manufacturing transmissive screen, screen mold, and transmissive multi-vision projector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a transmission screen used for a video projector and the like, a screen mold, and a rear projection type multi-vision projector using the transmission screen.

[0002]

2. Description of the Related Art A transmission screen used for a projector or the like is composed of a Fresnel lens and a lenticular lens. The lenticular lens contains a light scattering substance made of an inorganic or organic material having a particle size of 0.45 to 25 μm in order to have a diffusion action. The Fresnel lens has a function of refracting the divergent light from the projection lens toward the observer, and has a lens surface composed of a large number of concentric V-shaped grooves and a non-lens surface on one side of a transparent synthetic resin disk. Usually, a hot press molding method is adopted for the production of a Fresnel lens screen.

In the hot press method, a V-shaped groove opposite to the Fresnel lens shape is formed on a copper plate having a thickness of 1 to 3 mm between a cutting die concentrically cut and a mirror-finished metal plate.
It is manufactured by sandwiching a 4 mm transparent synthetic resin board, shaping under pressure after heating. The lenticular lens screen is manufactured by an extrusion method using a mold roll.

In a projection multi-system using the above-mentioned transmissive screen and arranged at a place where an advertisement, a publicity or the like is performed, a plurality of units (2, 4, 6, 8, etc.) incorporating the above-mentioned Fresnel lens and lenticular lens are provided.
Are stacked and used.

[0005]

However, according to the conventional manufacturing method, one cutting die is required to mold one surface of the lens, and a large number of cutting dies are required to mass-produce Fresnel lenses and lenticular lenses. Needed. The cutting dies are expensive at 1.5 to 2 million yen per surface and require a large number of surfaces, so that the cost of the dies increases the production cost. Also, in the above hot press molding method, it takes 60 to 90 minutes to mold one surface, and it is difficult to remove the molded Fresnel lens screen unless it is separated from the cutting mold at a high temperature of 80 to 100 ° C. This was also a cause of the occurrence of defects due to unevenness.

In a projection multi-system, when a plurality of projectors (2, 4, 6, 8, etc.) are stacked and used, the divergent light from the projection lens does not reach the image portion between the screens of the projectors. Observed black. Therefore, it has been considered that a plurality of Fresnel lens screens are bonded on a cut surface and fixed to a transparent support plate of an enlarged size.However, part of the divergent light from the projection lens that has reached the bonding surface of the Fresnel lens screen is The light is reflected by the difference in the refractive index of the joint and formed as a ghost image on both sides of the joint surface, and each multi-screen is observed as if the surrounding light beams were outlined. As described above, when the screen has a multi-layer structure, multiple reflections at the boundary surface between the screens increase, which causes deterioration in contrast.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and a thermosetting resin having plasticity in a mold having a lens surface opposite to a Fresnel lens screen is formed. Casting a mold to produce an inverted mold,
A step of arranging two or four of the reversing dies on the same plane, casting a high-strength, heat-resistant thermosetting resin on the same and manufacturing a resin mold, and forming an ultraviolet-curable resin on the resin mold. Applying, a step of vacuum degassing the bubbles contained in the applied ultraviolet curable resin, a step of applying a back film to the applied surface of the ultraviolet curable resin, and a step of applying the ultraviolet curable resin. and curing the ultraviolet irradiation of the ultraviolet curable resin, a step of peeling the transmission screen cured with ultraviolet from the resin mold, a step of finishing by cutting the transmission screen fabricated into a predetermined size And a projection multi-system is realized by a transmission type screen constituted by a Fresnel lens screen or the like manufactured in each of the above steps.

[0008]

The present invention makes it possible to manufacture two or more Fresnel lenses in a single step, and to realize a projection multi-system using a transmissive screen having no seamless Fresnel lenses.

[0009]

Embodiments of the present invention will be described below. FIG. 1 is a diagram showing a reversing type manufacturing apparatus for a Fresnel lens screen, in which 1 is a vacuum vessel, 2 is a vacuum pump, 3 is a glass plate having a smooth surface, 4 is a heat platen, and 5 is, for example, a separation plate. It is an additional type which is a material excellent in moldability, transferability, dimensional accuracy, specularity, etc., and a non-filler silicone resin, which is molded into a Fresnel lens inversion type. Reference numeral 6 denotes a cutting die in which a V-shaped groove opposite to the Fresnel lens shape is concentrically cut, and reference numeral 7 denotes an injection port of the silicon resin inversion die 5.

After the silicone resin inversion mold 5 is cast from the injection port 7 of the vacuum vessel 1 onto the cutting die 6 in which the Fresnel lens pattern is engraved, the injection port 7 is sealed, and the silicon Vacuum degassing of the resin inversion mold 5 is performed. After vacuum degassing, a glass plate 3 is placed on the silicon resin inversion mold 5 to keep the thickness uniform.

FIG. 2 is an enlarged view of a range A surrounded by a dashed line shown in FIG. After casting the silicone resin inversion mold 5 in this way, the heat platen 4
After precuring at 5 ° C. for 24 hours, the mold is released from the cutting die 6. Then, in order to increase the strength and stability of the silicon resin inversion mold 5, after-curing is performed in a heating furnace at 75 ° C. for 14 hours.

Next, a process for manufacturing a resin mold for Fresnel lens screen molding using the silicon resin inversion mold 5 (hereinafter referred to as an original silicon resin inversion mold) manufactured by the above-described molding method will be described. FIG. 4 is a view showing an apparatus for manufacturing a resin mold, which is substantially the same as the apparatus for manufacturing the original silicon reverse mold 5 shown in FIG. 1, and the same reference numerals denote the same parts. In this figure, reference numeral 8 denotes a bismaleimide triazine resin molded into a resin mold, which is a material excellent in, for example, high strength, heat resistance, dimensional stability, and the like.

The original silicon resin reverse mold 5 manufactured by the reverse mold manufacturing apparatus described with reference to FIG. 1 is cut into a predetermined size by, for example, a sharp blade, and the cut original silicon resin reverse mold 5 is joined. It is arranged in the vacuum vessel 1 in the state. FIGS. 3A and 3B are explanatory views in the case where the original silicon resin inversion mold 5 is joined. FIG. 3A is a diagram showing a case where two long sides of the original silicone resin inversion mold 5 are cut and joined, for example, and the original silicon resin inversion mold 5 is used.
Are bonded to each other, it is possible to obtain a silicon resin inversion mold 5a having two fresnel lens patterns formed by concentric V-shaped grooves. FIG. 3
(B) is a diagram showing a case where four original silicone resin inversion molds 5 are used, and one of the long sides and one short side of the four original silicone resin inversion molds 5 are cut and joined. is there.
Also in this case, it is possible to obtain a silicon resin inversion type 5b having four V-shaped groove-shaped concentric Fresnel lens patterns on one surface. Hereinafter, a step of molding a resin mold using the two bonded silicon resin inversion molds 5a shown in FIG. 3A will be described with reference to FIG.

A bismaleimide triazine resin 8 heated to the same temperature is poured into a silicon resin inversion mold 5a previously heated and maintained at 75 ° C. from the injection port 7 of the vacuum vessel 1, and the injection port 7 is sealed. Vacuum degassing is performed by the vacuum pump 2. Then, after vacuum defoaming, a glass plate 3 having a smooth surface is arranged on the back surface of the bismaleimide triazine resin 8 in order to secure the uniformity of the thickness.

FIG. 5 is an enlarged view of a range B surrounded by a dashed line shown in FIG. After the bismaleimide triazine resin 8 is cast as described above, the pre-curing step at 75 ° C. and 14 hrs is performed on the hot platen 4, and then the mold is released from the silicon resin inversion mold 5 a. Then, in order to increase the strength and dimensional stability of the demolded bismaleimide triazine resin (resin mold) 8, the temperature is set to 150 ° C. in a heating furnace.
After-curing for 24 hrs.

Next, a molding process of a Fresnel lens screen using the resin mold 8 manufactured by such a process will be described. FIG. 6 is a view showing a continuous manufacturing apparatus for a Fresnel lens screen. This continuous manufacturing apparatus includes a coating zone Z ₁ , a vacuum defoaming zone Z ₂ , a laminating zone Z
₃ , a curing zone Z ₄ , and a demolding zone Z ₅ , comprising five steps, 11 is a resin feeder for applying the ultraviolet curing resin 9, 12 is a vacuum exhaust chamber, 12 a is a vacuum pump, and 13 is a pressure roller. , 14 indicate an ultraviolet irradiation device.

Firstly, in a coating with zones Z _1, urethane acrylate-based resin feeder 11 a molten state, or the ultraviolet curing resin 9 ester acrylate or the like is supplied,
The resin mold 8 having the above-described 2 to 4 Fresnel lens patterns formed on the same surface is transported by a conveyor. Then, the resin is uniformly applied onto the resin mold 8. Conditions suitable for coating include an ultraviolet curing temperature and a resin viscosity of 500.
１００100 cps / at 25 ° C., resin mold transfer speed: 40
１２０120 m / min, and a coating amount of 30 to 100 gr / m ² are desirable.

A resin mold 8 coated with an ultraviolet curing resin 9
Is transferred to the vacuum exhaust chamber 12 of the vacuum degassing zone Z _2, causing pinholes in the Fresnel lens screen mixed in the ultraviolet curing resin 9 layers in a vacuum defoaming air bubbles by the vacuum pump 12a I do. Defoaming conditions are: ultimate vacuum: 50 to 0.01 Torr, evacuation time 60 to
80 sec is desirable.

[0019] When the vacuum degassing treatment in a vacuum degassing zone Z ₂ is completed, the resin mold 8 is transferred to the laminate zone Z _3, thickness is cut to the size of the pre-resin mold 8 fed from the upper portion Acrylic resin, acrylic styrene resin, polyester resin, polycarbonate
A backing material 10 such as polycarbonate, vinyl chloride resin, or the like is applied to the surface to which the ultraviolet curable resin 9 is applied through a gap between the pressure rolls 13.

The back member 10 is transferred to the next hardening zone Z ₄ Once deposited, the illuminated surface strength by the ultraviolet irradiation device 14 15~40sec between about 20 mW / cd, ultraviolet curing resin 8 is irradiated with UV To cure. FIG. 7 (a)
, In the curing zone Z _4, a partial sectional enlarged view of the ultraviolet curable resin, the back member 10 which is coated on the resin mold 8 when the ultraviolet rays are irradiated. As shown in the figure, the ultraviolet curing resin 9 has a V opposite to the resin mold 8.
The V-shaped groove is cured in a molded state.

[0021] In step of hardening zone Z _4, a resin mold 8 curing process by ultraviolet irradiation is completed is transferred to demolding zone Z _5, not shown, for example, a hoist or the like is suspended above The ultraviolet curing resin (Fresnel lens screen) 9 is peeled off from the resin mold 8 by utilizing. FIG.
(B) is an enlarged partial cross-sectional view of the ultraviolet curing resin (Fresnel lens screen) 9 peeled off from the resin mold 8.

The ultraviolet curable resin (Fresnel lens screen) 9 peeled off from the resin mold 8 in this manner is cut into two parts by cutting with, for example, a laser beam or the like at the boundary between two molded concentric Fresnel lens patterns. it allows a single step of the Fresnel lens screen 9 until the coating with zones Z ₁ ~ demolding zone Z ₅ shown in FIG. 7 (b), Ya improved two fabrication can be a result productivity Materials used can be reduced.

Next, a Fresnel lens manufactured by using a resin mold molded by the four-piece silicon resin inversion mold 5b described in FIG. 3B and having four lens surfaces per one piece is cut. In the following, an embodiment will be described in which a single Fresnel lens is used in a projection multi-system.

FIG. 8 is a schematic diagram of a projection multi-system when four projectors are used. In this figure, reference numeral 20 denotes an outer housing of the projection multi-system, 21 denotes a projection type three primary color cathode ray tube arranged in each of the chambers that divide the rear surface of the outer housing 20 into four, and a front surface of the outer housing 20 , transmission type manufactured by the manufacturing method described above screen, i.e. the three primary colors bra
A Fresnel lens 22 having four Fresnel lens patterns (not shown) and a lenticular lens 24 are arranged at positions opposing the housing tube 21.

The difference between the projection system of the present embodiment shown in FIG. 8 and the projection system using a transmission type screen constituted by a conventional junction type Fresnel lens or the like will be described below with reference to FIGS. 9, 10 and 11.

FIGS. 9A and 9B are diagrams showing a Fresnel lens used for the screen of the projection multi-system of this embodiment and a conventional Fresnel lens.
FIG. 9 (a) shows that four Fresnel lenses 22a manufactured one by one are joined, and four lens surfaces A, B, C,
FIG. 4 is a diagram showing a transmission screen using a conventional junction type Fresnel lens having a D. As shown in FIG.
The joining surface 22b when 2a is joined exists on the screen. FIG. 9 (b) is a view showing a transmission type screen using a Fresnel lens 22 integrally molded and similarly having four lens surfaces A, B, C and D on one sheet.

FIGS. 10 (a) and 10 (b) correspond to FIGS.
10B is a partially enlarged cross-sectional view taken along line X-Y shown in FIG. 10B, where FIG. 10A is a transmission screen using a conventional junction type Fresnel lens, and FIG. 10B is a Fresnel of the present embodiment. FIG. 2 is a partially enlarged cross-sectional view of a transmission screen using a lens.
In this figure, 23 is a transparent support plate, and 24 is a lenticular lens for obtaining a diffusion action. As shown in FIG. 10A, the conventional junction type Fresnel lens 22a has a junction surface 22b within a range of a circle C indicated by a solid line.
For this purpose, a transparent support plate 23 for maintaining the smoothness and the adhesive strength of the screen is provided. On the other hand, since the Fresnel lens 22 of this embodiment is integrally molded, there is no joint surface as shown in the range of the circle D in FIG. 10B. Therefore, it is not necessary to provide the transparent support plate 23 in the transmission screen.

FIGS. 11 (a) and (b) show FIGS.
It is a figure showing a difference of multiple reflection of a transmissive screen explained in (b). FIG. 11A is a diagram showing a partial cross section of a conventional transmissive screen, in which light rays R of a projected image projected from behind are transparent support plate 23 and Fresnel lens 22.
a, when passing through the lenticular lens 24, it
Reflected light rays Rx are generated at approximately six points on each of the incident light surface and the outgoing light surface . However, in the transmission type screen using the Fresnel lens 22 of the present embodiment shown in FIG. 11B, the transparent reflection plate 23 can be omitted as described above, so that the incident light surface of the transparent support plate 23 and the light exiting therefrom can be obtained. The contrast is improved by not generating the reflected light beam Rx on the light emitting surface , that is, by reducing the number of components of the transmission screen.

[0029]

As described above, it was impossible to cut two lens patterns on one sheet with a metal mold, but the metal mold was formed on the cutting mold by the manufacturing method of the present invention. By molding a resin mold with two or more original silicone resin inversion molds, a resin mold having two or more Fresnel lens patterns can be obtained, and a Fresnel lens screen is manufactured using this resin mold. Accordingly, two or more Fresnel lens screens can be manufactured in one manufacturing process, which cannot be achieved by the conventional hot press working method using a cut metal mold. Therefore, the productivity can be improved and the materials used can be reduced, so that the cost can be significantly reduced. Further, the manufacturing time can be greatly reduced, and it becomes easy to make an unmanned automated line.

According to the above-described manufacturing method, a Fresnel lens having a plurality of Fresnel lens surfaces used for a transmission type multi-vision projector can be obtained in one process, and is used for a conventional adhesive type transmission type screen. This eliminates the need for a transparent support plate, prevents multiple reflections at the boundary surface due to the multilayer structure, and improves contrast performance. Further, it is possible to prevent a ghost image or the like, which has been observed because a part of the light beam reaching the bonding surface is imaged on both sides of the bonding surface due to the difference in the refractive index of the bonding portion.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram in the case of manufacturing an inverted mold of a Fresnel lens according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view of a reversing mold being manufactured.

FIG. 3 is an explanatory diagram in a case where two or four inversion dies are joined.

FIG. 4 is an explanatory view in the case of manufacturing a resin mold for a Fresnel lens according to an embodiment of the present invention.

FIG. 5 is a partially enlarged view of a resin mold during manufacture.

FIG. 6 is a view showing a manufacturing process of the Fresnel lens.

FIG. 7 is a partial cross-sectional view of the Fresnel lens during curing and after demolding.

FIG. 8 is a schematic diagram of a projection multi-system using a Fresnel lens according to an embodiment of the present invention.

FIG. 9 is a diagram showing a difference between the Fresnel lens according to the embodiment of the present invention and a conventional Fresnel lens.

FIG. 10 is a diagram showing the difference between the configuration of the transmission screen of the embodiment of the present invention and the configuration of the conventional transmission screen.

FIG. 11 is a diagram showing a difference between reflected light beams of the transmission screen according to the embodiment of the present invention and a conventional transmission screen.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 2, 12a Vacuum pump 3 Glass plate 4 Heat platen 5, 5a Silicon resin inversion type 6 Metal cutting die 8 Resin die 9 Ultraviolet curing resin 10 Backing material 11 Resin feeder 12 Vacuum exhaust chamber 13 Pressure roller 14 Ultraviolet irradiation device 21 Projector 22, 22a Fresnel lens 22b Joining surface 23 Transparent support plate 24 Lenticular lens R ray Rx Reflected ray

Claims (5)

(57) [Claims] 1. A cutting mold for a Fresnel lens pattern
By removing the mold, at least two or more inverted molds are formed.
And cut the sides so that the two or more inversion molds are joined.
By juxtaposing a high-strength, heat-resistant resin material from the top
Have at least two Fresnel lens patterns
That the resin mold molding, an ultraviolet curable resin is applied to the resin mold, and irradiated with ultraviolet rays to the UV-curable resin, transparently a transmission screen which produced that Do from step separated from the resin mold Mold screen manufacturing method. 2. A cutting mold for a Fresnel lens pattern
By removing the mold, at least two or more inverted molds are formed.
Form, then juxtaposing the two or more inverted over the plate, high strength, the heat resistance of the resin material is cast from the upper and demolded infusion resin material from said inverting it Less
Trees with at least two Fresnel lens patterns
A method for manufacturing an oil mold. 3. A cutting die for a Fresnel lens pattern.
Cast silicone resin and remove the inverted mold of the silicone resin from the cutting mold
By using at least two sheets of the original silicone resin
A mold was formed, and then the two or more original silicone resin inverted molds were juxtaposed.
Place a heat platen, cast a high-strength, heat-resistant resin material from above , and remove the cast resin material from the original silicone resin inverted mold.
Have multiple Fresnel lens patterns
Manufacturing method of resin mold. 4. A silicone resin is poured onto a Fresnel lens pattern cutting die placed in a vacuum container, and the injection port is sealed, followed by vacuum degassing with a vacuum pump. at least form two or more sheets of the original silicone resin inverted mold by demolding from the cutting die, then heat plate was parallel location of the two or more original silicone resin inverted mold mounting in the vacuum chamber And then casting a high-strength, heat-resistant resin material from above, and removing the cast resin material from the original silicone resin inversion mold to produce a resin mold having two or more Fresnel lens patterns. Method. 5. A high-strength, heat-resistant bismaleimide having two or more original silicone resin inverted molds side-cut by cutting a side surface of the original silicone resin inverted mold having an inverted mold of a Fresnel lens pattern cast on a surface thereof. After casting the triazine resin,
A resin mold characterized by being removed from the mold.