JPH0381702A - Production of lens sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a Fresnel lens or a lenticular lens used in a video projection television screen,
Or a lens such as a Fresnel lens for focusing light y ++
).

(Prior technology) When manufacturing lens sheets such as Fresnel lenses and lenticular lenses, when the size is relatively small and mass production is required, synthetic resin injection is used.

Molding method The force method is used, but when producing relatively large lens sheets for screens or light condensing as mentioned above, a resin plate is brought into contact with a flat lens mold, and this is heated and pressurized. This is the inside of a 14g shell, which is manufactured by transferring the lens surface.

However, when this method is used, the time required for heating and cooling is long and productivity cannot be increased.

For this reason, a method has recently been proposed in which an ultraviolet curable resin liquid is interposed between the lens mold and a substrate such as a transparent resin, and the liquid is cured by irradiating ultraviolet rays (Japanese Patent Application Laid-Open No. 1777-1983).
(See Publication No. 15).

(Issues to be solved by the invention) However, in the above method, air bubbles are likely to enter when the ultraviolet curable resin liquid is spread on the lens mold, or when the transparent resin is layered on top of the ultraviolet curable resin liquid. It is extremely difficult to remove the trapped air bubbles.

In view of this situation, the present invention aims to manufacture a lens sheet that is free of bubbles and has excellent performance by using a transparent resin film and taking advantage of its flexibility.

(Means for Solving the Problems) That is, the present invention has been made to achieve the above-mentioned problems, and its gist is to provide a lens in which a lens portion made of ultraviolet curable resin is formed on one side of a transparent resin film. In the sheet manufacturing method, an ultraviolet curable resin liquid is applied to one side edge of a lens mold so as to form a liquid pool, and the above-mentioned transparent resin film is coated thereon, and the film extends from the liquid pool side to the opposite side. The method of manufacturing a lens sheet is characterized by spreading an ultraviolet curable resin liquid while squeezing and then curing it by irradiating it with ultraviolet rays.

The invention will be explained below with reference to the examples of the drawings.

Figure 1 shows the state in which the ultraviolet curing resin liquid (2) is applied so as to form a pool on one side edge of the lens mold (1), and Figure 2 shows the transparent resin film (3) applied on top of this. ) is shown covered. Then, in this state, the present invention uses the ironing rod (4) to squeeze i from the liquid pool side to the opposite side.
Then, as shown in FIG. 4, the ultraviolet curable resin liquid (2) is uniformly spread.

At this time, apply pressure from the ironing rod (4) to spread it.
The bubbles generated during this time can be pushed out, but it is better to move the squeezing rod (4) slowly. Then the fourth
As shown in the figure, a lens sheet as shown in FIG. 5 can be obtained by irradiating ultraviolet rays from the side of the transparent resin film (3) to cure it and removing it from the mold.

As the transparent resin film (3) used in the present invention, various films such as polyethylene, polypropylene, polyester, polymethacrylic, polycarbonate, polystyrene, or polyvinyl chloride can be used. If there is a concern about the adhesion of
It is preferable to use a film that has been subjected to adhesion improvement treatment such as primer treatment.

Further, as the lens type used in the present invention, Fresnel lens,
A metal or synthetic resin mold with a surface that provides a lenticular lens can be used.

Further, as the ultraviolet curable resin, there are no particular limitations, but commonly used epoxy acrylates, urethacyacrylates, polyester acrylates, polyol acrylates, etc. can be used. and reactive diluent monomers used at the same time, including one or more reactive mono-, di- or polyfunctional acrylic monomers, such as pentaerythritol triacrylate, trimethylolpropane triacrylate, hexanediol diacrylate, tetraethylene glycol diacrylate, etc. Acrylate, infornyl acrylate, etc. can be used.

The ironing rod (4) used in the present invention may be a metal roll or a rubber roll made of butyl rubber, urethane rubber, silicone rubber, isoprene rubber, etc., but a doctor blade can be used instead of the ironing rod (4). You can stay there.

Further, in the method of the present invention, a transparent resin film (3) in a continuous state and a plurality of lens molds (1) are used.
It is also possible to manufacture continuously by performing the steps shown in FIGS. 5 through 5 intermittently depending on the required time.

(Example) Hereinafter, specific examples will be described.

As a lens type, it is 800w long x 1.000m wide.

A 3-inch thick brass material with a Fresnel lens surface was prepared, and an ultraviolet curable resin liquid having the following composition was prepared.

・Mitsubishi Rayon urethane acrylate RTRX-6
o3aJ (So heavy weight, manufactured by Mitsubishi Rayon Co., Ltd. and droxyethyl acrylate "acryester HO"
J 40 Weight: Benzophenone 3 weight (based on the total amount above) Also, as a transparent resin film, a polyester film "A O (D) grade manufactured by Toshisha Co., Ltd." on which a primer layer with a thickness of 125 μm was formed was prepared. .

A drop of approximately 5009 ultraviolet curable resin liquid was placed on one of the short sides of the lens mold to form a pool and then applied. Next, cover with a transparent resin film with the primer layer inside, place a butyl rubber roll with an outer diameter of 100 mm on the side edge of the lens mold on the liquid reservoir side, and press it against the transparent resin film at a speed of 50 mm/min. Moved on side 1. The average thickness of the ultraviolet curable resin liquid at this time was about 500 μm.

After spreading the ultraviolet curable resin liquid between the lens mold and the transparent resin film as described above, three 80W ultraviolet lamps were lit at a distance of 200 m from the transparent resin film side to irradiate it with ultraviolet rays. hardened. When the mold was removed after curing, a lens y) with good performance and no bubbles was obtained.

(Effects of the Invention) Since the present invention has the structure as described in detail above, the flexibility of the transparent resin film is utilized to prevent the generation of air bubbles, and the lens portion made of ultraviolet curable resin is formed on this film. This method has the advantage of being able to efficiently produce a lens sheet made of

[Brief explanation of drawings]

1 to 5 are cross-sectional views of each manufacturing process showing an embodiment of the present invention. (1)...Lens type (2)...Ultraviolet curing resin liquid (3)...Transparent resin film (4)...Stringing stick

Claims (1)

[Claims] In a method for manufacturing a lens sheet in which a lens part is formed using an ultraviolet curable resin on one side of a transparent resin film, an ultraviolet curable resin liquid is applied so as to form a pool on one side edge of the lens mold, and the above-described liquid is applied on top of this. A method for manufacturing a lens sheet, which comprises coating a transparent resin film, spreading an ultraviolet curable resin liquid while squeezing the film from the liquid reservoir side to the opposite side, and then curing the film by irradiating it with ultraviolet rays.