JPH07218704A - Fresnel lens body manufacturing method - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a manufacturing method capable of efficiently manufacturing a Fresnel lens body. [Structure] A plurality of Fresnel members 2 having one Fresnel shape a are arranged in parallel to form a first mold 3 on which a plurality of Fresnel shapes a are formed, and subsequently, on the first mold 3 after curing. Also, an appropriate resin 1 having flexibility is provided, and subsequently,
The second mold 5 is formed by demolding and transferring the plurality of Fresnel shapes a to form a plurality of Fresnel shapes b. Subsequently, an appropriate resin 4 is provided on the second mold 5, and subsequently, It is a method of manufacturing the Fresnel lens body 6 in which a plurality of Fresnel shapes a are formed by demolding and transferring the plurality of Fresnel shapes b.

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 Fresnel lens body used for a multi-vision screen.

[0002]

2. Description of the Related Art In recent years, multi-vision has been widely used, and the multi-vision screen 7 is not simply a large screen, but a screen 8 in which a plurality of screens 8 are arranged vertically and horizontally. Which is an aggregate of the images, and each image is projected on each screen 8 or one image is projected on the entire screen 7.

Up to now, for example, in the case of manufacturing a multi-vision screen 7 in which four screens 8 are connected in series as shown in FIG. 1, each separately manufactured screen 8 is a metal fitting as shown in FIG. It was connected by 9 (joint).

However, this structure naturally has a drawback in that the image is obstructed by the metal fitting 9.

[0007] Therefore, although the structure is not a structure in which four separately manufactured screens 8 are connected to each other, but partitions are made, research is being made on a screen 7 for multi-vision, which has a single structure, but at present, it is not completed. Not not.

This is because the multi-vision screen 7 has a plurality of divided screens 8 as described above.
And the Fresnel lens 10 as shown in FIG. 3 is combined for collecting light in each section.

The cross section of this Fresnel lens 10 is shown in FIG.
As shown in FIG. 5, the depth of the convex is deeper toward the outside and shallower toward the center. Therefore, the Fresnel lens 10 as shown in FIG.
As a matter of fact, the Fresnel lens body 6 in which four pieces are assembled cannot be molded.

More specifically, for example, when the Fresnel lens 10 made of acrylic resin is molded with a mold, the acrylic resin 11 is laminated on the mold 12 and heated as shown in FIG.
During cooling (while it is soft), the acrylic resin 11 is released from the outside to the inside so as to be removed from the mold. This is because when cooled, the acrylic resin 11 contracts and cannot be demolded.

Therefore, if the Fresnel lens body 6 in which a plurality of Fresnel lenses 10 are assembled as shown in FIG. 5 is to be molded, the above-mentioned demolding cannot be performed (the Fresnel lens body can be peeled off from the outside). Since there is also a deep convexity on the center side of 6, it is very difficult to manufacture.

In such a case, there is nothing wrong with trying to forcibly remove the mold. In that case, when four dies are arranged in series, and when four Fresnel lenses 10 are used.
There is a case where a large single mold capable of simultaneously molding is formed. However, in the former case, if the molds 2 do not match each other well, the streak ( Line appears, and in the latter case, the cost of the mold becomes very high.

In any case, it has been very difficult to manufacture the Fresnel lens body 6 in which a plurality of Fresnel lenses 10 as shown in FIG. 5 are assembled.

The present invention solves such a problem, and it is a technical object to provide a method of manufacturing a Fresnel lens body capable of efficiently manufacturing the Fresnel lens body as shown in FIG.

[0013]

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

A plurality of Fresnel members 2 having one Fresnel shape a are arranged in parallel to form a first mold 3 having a plurality of Fresnel shapes a, and subsequently, on the first mold 3 after curing. Also, a suitable resin 1 having flexibility is provided, and then the second mold 5 is formed by demolding and transferring a plurality of Fresnel shapes a to form a plurality of Fresnel shapes b. An appropriate resin 4 is provided on the second mold 5, and subsequently,
The present invention relates to a method of manufacturing a Fresnel lens body, which comprises removing the mold and manufacturing the Fresnel lens body 6 having a plurality of Fresnel shapes a formed by transferring the plurality of Fresnel shapes b.

A method of manufacturing a Fresnel lens body 6 according to claim 1, wherein a silicone resin is adopted as an appropriate resin 1 having flexibility even after curing provided on the first mold 3, and a second mold. The present invention relates to a method for manufacturing a Fresnel lens body, characterized in that an ultraviolet curable resin 4 is adopted as an appropriate resin 4 provided on the surface 5.

[0016]

The resin 1 provided on the first mold 3 has flexibility even after being cured, and therefore can be easily released from the mold. Therefore, the second mold 5 can be easily obtained. Since 5 is naturally flexible, even if the resin provided on the second mold 5 is cured and contracted, the mold can be easily removed.

The Fresnel lens body 6 is not molded by one-time transfer, and the Fresnel lens body 6 is not transferred by two-time transfer.
Therefore, even if the first mold 3 is formed by using a plurality of Fresnel members 2, it is possible to prevent the abutting portions of the Fresnel members 2 from clearly appearing on the Fresnel lens body 6.

[0018]

EXAMPLE A first mold 3 is formed by arranging four Fresnel members 2 having a Fresnel shape a side by side. This Fresnel member 2 uses a Fresnel lens 10 (convex lens). When the Fresnel lenses 10 are arranged side by side, the side surface of the Fresnel lenses 10 has an acrylic resin-based double-sided adhesive tape on the laser-cut end surface so that there is no gap as much as possible when the Fresnel lenses 10 are butted. , Apply pressure from both sides and connect both without a gap.

Subsequently, a resin 1 such as a silicone resin (Shin-Etsu Silicone 1300-10, which has flexibility even after curing on the first mold 3 and does not hinder the demolding.
T) is cast (see FIG. 7), followed by demolding to form a second mold 5 having four Fresnel shapes b formed by transferring the four Fresnel shapes a. An ultraviolet curable resin 4 which is easy to cure is applied and laminated on the second mold 5,
Further, a support material 13 (see FIG. 8) is laminated, and then, for flattening, for example, a pair of rollers is passed through, followed by irradiation with ultraviolet rays to cure the ultraviolet curable resin 4, and then demolding. By transferring the four Fresnel shapes b, four Fresnel shapes a are formed to form the Fresnel lens body 6 (convex lens).

The ultraviolet curable resin 4 and the support material 13 may be replaced by cast molding using a transparent resin (acrylic urethane resin and epoxy resin).

According to the present embodiment, since the silicone resin having flexibility even after curing is used, the mold release from the first mold 3 and the UV curable resin 4 from the second mold 5 can be performed. The Fresnel lens body 6 in which a plurality of Fresnel lenses 10 are assembled can be formed satisfactorily and efficiently.

The Fresnel lens body 6 is obtained by transferring twice.
To form the molded product, a streak (line) generated by a gap between the Fresnel lens body 6 as the molded product and the Fresnel lens 10 butting.
Hardly appears.

No special mold is required, and since the Fresnel lens 10 is only used, there is no manufacturing cost (needless to say, a mold for molding the Fresnel lens 10 is necessary).

[0024]

As described above, the present invention makes it possible to efficiently and inexpensively manufacture a Fresnel lens body having excellent optical characteristics.

[Brief description of drawings]

FIG. 1 is a front view of a multi-vision screen.

FIG. 2 is a vertical sectional view of the above.

FIG. 3 is a perspective view with a part of a Fresnel lens omitted.

FIG. 4 is a sectional view of the same.

FIG. 5 is a perspective view of a Fresnel lens body.

FIG. 6 is a cross-sectional view illustrating the manufacturing process of the Fresnel lens.

FIG. 7 is a drawing explaining the manufacturing process of this embodiment.

FIG. 8 is a drawing explaining the manufacturing process of this embodiment.

[Explanation of symbols]

 1 Resin 2 Fresnel member 3 First type 4 Resin 5 Second type 6 Fresnel lens body a Fresnel shape b Fresnel shape

Claims (2)

[Claims] 1. A plurality of Fresnel members each having one Fresnel shape a are arranged side by side to form a first mold having a plurality of Fresnel shapes a, and subsequently, even after curing on the first mold. An appropriate resin having flexibility is provided, and then the mold is released to form a second mold in which a plurality of Fresnel shapes b are formed by transferring the plurality of Fresnel shapes a, and then the second mold is formed. An appropriate resin is provided on the upper surface, and then a plurality of Fresnel shapes a are formed by demolding and transferring the plurality of Fresnel shapes a.
A method of manufacturing a Fresnel lens body, comprising manufacturing a Fresnel lens body having a groove formed therein. 2. The method of manufacturing a Fresnel lens body according to claim 1, wherein a silicone resin is used as an appropriate resin having flexibility even after curing provided on the first mold, and the second mold is used. A method of manufacturing a Fresnel lens body, characterized in that an ultraviolet curable resin is adopted as an appropriate resin provided in the.