JPH0345901A - Production of modified fly eye lens - Google Patents

Abstract

PURPOSE:To efficiently produce the modified fly eye lens by curing a UV curing type resin and parting the molding thereof from a mold, then uniaxially stretching the synthetic resin substrate formed with the lens. CONSTITUTION:The synthetic resin substrate 3 and the lens mold 1 having the mold surface for forming the fly eye lens are disposed to face each other and a UV curing type resin liquid 2 is interposed between the substrate and the mold. The liquid is then irradiated with UV rays and is thereby cured; thereafter, the synthetic resin substrate 3 formed with the lens 4 is uniaxially stretched. Transparent synthetic resins, such as methacrylic resin, polycarbonate resin and styrene resin, are used as the synthetic resin substrate 2. An epoxy acrylate, urethane acrylate, polyester acrylate, etc., are used as the UV curing type resin. The modified fly eye lens having a difference in the transmitted light distribution in a vertical direction and horizontal direction is efficiently produced in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for efficiently manufacturing a modified fly's eye lens for use in a transmission screen such as a projection television.

(Prior Art) A transmissive screen used as a projection television screen is required to have a wide viewing angle in the horizontal direction, be bright as a whole, and have no reduction in contrast due to external light. A wider field of view is also desired.

In response to these demands, various types of screens have been proposed in the past. For example, a lenticular lens extending vertically is provided on the light source side, and a horizontally extending lenticular lens is provided on the observation side in a condensing section corresponding to the lenticular lens. Screens provided with directional lenticular lenses are known. (Unexamined Japanese Patent Publication No. 58-216233,
-216234 publication and Utility Model Application Publication No. 57-124838
Publication No.).

However, with such screens, although the vertical viewing range is certainly widened, it is difficult to widen the horizontal viewing range, which has a high weight, and in the case of screens used for 3-tube 3-lens TVs, the color uniformity There were aspects of Mitty that were difficult to fully express.

In addition to the above examples, there is also a screen (Japanese Unexamined Patent Application Publication No. 49/1989) with many fly's eye lenses formed on the observation side.
109037, Japanese Patent Laid-Open No. 58-216235) are also known, but these fly-eye lenses are difficult to form and are difficult to put into practical use.

(Problems to be Solved by the Invention) In view of this situation, the present invention provides a method for efficiently manufacturing a modified fly's eye lens that can secure a sufficient horizontal viewing range and at the same time ensure a vertical viewing range. This is what we are trying to provide.

(Means for Solving the Problems) That is, the present invention has been made to achieve the above problems, and its gist is to provide a synthetic resin substrate and a mold surface for forming a fly's eye lens. and a lens mold, with an ultraviolet curing resin liquid interposed between them,
A method for manufacturing a modified fly's eye lens, which comprises removing the mold after curing by irradiating ultraviolet rays, and then stretching the synthetic resin substrate on which the lens is formed in a uniaxial direction.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

In Fig. 1, (1) is a lens mold, which has a mold surface for forming a fly's eye lens, but this mold surface may be formed directly on a metal mold, or it can be It may also be obtained by transferring from a fly's eye lens sheet.

Then, this lens mold (1) and a synthetic resin substrate (2) are placed opposite each other, and an ultraviolet curable resin liquid (3) is interposed between them.
The synthetic resin substrate (2) used in this case is a transparent synthetic resin such as methacrylic resin, polycarbonate resin, styrene resin, or vinyl chloride resin.

In addition, as ultraviolet curable resins, - epoxy acrylate type, urethane acrylate type used in the shell,
A polyester acrylate type or a polyol acrylate type is used, but it is desirable that the molecular chain between the functional groups is long so that it can be thermoformed to some extent even after curing. For example, in a structure like , the sum of n++++ is 8~
It is desirable to use, as the basic monomer, something that has a concentration of 1O or more. The reactive diluent monomer used at the same time can be one or more reactive mono-, di- or polyfunctional acrylic monomers, such as pentaerythritol triacrylate, trimethylolpropane triacrylate, hexanediol diacrylate, tetraethylene glycol diacrylate, etc. Acrylate, isoformyl acrylate, etc. are used. Desirably, monomers with a small number of functional groups that are difficult to form a strong crosslinked structure or monomers with long molecular chains between functional groups are preferable.

Figure 3 shows a synthetic resin substrate (2) on which a lens (4) is formed.
) is shown stretched in the - axial direction, but specifically, as shown in Figure 5 (A), support frames (5) are sandwiched on both sides, heated, and stretched as shown in (B). Stretch. Furthermore, as shown in Fig. 6, if the heated synthetic resin substrate (2) is ejected and molded using an ejector rod (6) with a slippery tip and stretched uniaxially, it is possible to manufacture it efficiently and to reduce the stretching ratio. Can be regulated.

The lens mold (1) used in the present invention is preferably transferred from a fly's eye lens sheet prepared in advance as described above, but the mold material to be transferred may include silicone resin, epoxy resin, urethane resin, etc. The following casting materials are used.

Further, if the fly's eye lens sheet has good heat resistance, thermal transfer may be performed using polyolefin resin or polyester resin. The fly-eye lens sheet used for this transfer is
A transfer mold is made using a matrix packed with bottles with spherical tips or a matrix filled with spherical glass beads or metal balls, and this mold can be used for production.

FIG. 4 shows a modified fly's eye lens obtained according to the present invention, in which the lens is stretched in the -axial direction (4
) are arranged in large numbers and the directivity is different in the vertical and horizontal directions, making it possible to obtain a fly's eye lens that is effective as a transmissive screen for brosi-exception television.

(Example) Examples of the present invention will be described below.

Example 1 Production of lens mold> LEGTRICLITES
A #300 hexagonal fly-eye lens sheet made by Co., Ltd. was prepared. Note that the average diameter of the lens units formed on this sheet is 2.2 mm.

This fly's eye lens sheet has T
SE 3453 silicone resin was poured and cured to obtain a lens mold.

Production of fly-eye lens> An ultraviolet curable resin liquid having the following composition was poured into the lens mold described above.

(1) U m + n = 10 70 parts (3) 3 parts benzophenone Next, on top of this, a methacrylic resin plate manufactured by Mitsubishi Rayon "Acrylite #000J (does not contain ultraviolet absorber, thickness 3 mm)" was placed and cured by irradiation with three 80 W ultraviolet lamps at a speed of 5 m/min.The frame was removed to obtain a fly's eye lens.

<Production of deformed fly-eye lens> The fly-eye lens obtained above was heated at 180°C for 3
The sheet was heated for 0 minutes and then pushed up at a ratio of about 1/10 in height to width and stretched in a uniaxial direction to obtain a deformed fly's eye lens sheet. As a result, it was 1.02 times larger in the vertical direction and 0.98 times larger in the horizontal direction than the original fly's eye lens.

<Performance evaluation> Point the lens surface of the obtained modified fly-eye lens toward the light source,
A diffuser plate was placed on the observation side and the transmitted light distribution was measured.

FIG. 7 shows this result, and it can be seen that there is a difference between the vertical direction and the horizontal direction. Here, what is screen gain?
It is the ratio of the illuminance of a place illuminated by a light source to the brightness on the observation side of this place, and the value when the observation angle is 0, that is, directly in front, is indicated by GO, and when this value is 172, it is α
When it is 1/3, it is called the β value, which indicates the directional characteristics of the screen.

FIG. 8 shows the transmitted light distribution of the fly's eye lens before stretching in the -axial direction, but there is naturally no difference in the distribution in the vertical and horizontal directions.

Example 2 Using the fly's eye lens obtained in Example 1 as a matrix, a lens mold was produced in the same manner as in Example 1, and this mold was used to form a lens made of ultraviolet curable resin to form a fly's eye lens. I got the lens.

Subsequently, this fly's eye lens was stretched in the -axial direction in the same manner as in Example 1 to produce a deformed fly's eye lens. The fly-eye lens at this time was 1.16 times larger in the vertical direction and 0.85 times larger in the horizontal direction than the original lens.

FIG. 9 shows the results of measuring the transmitted light distribution of the obtained fly's eye lens, and it can be seen that the difference between the vertical direction and the horizontal direction is even wider than in FIG. 7.

(Effects of the Invention) Since the present invention has the configuration as described in detail above, it has the advantage of being able to efficiently manufacture a modified fly-eye lens with a difference in transmitted light distribution in the vertical and horizontal directions. .

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a state in which the ultraviolet curable resin liquid of the present invention is cured, FIG. 2 is a sectional view showing a fly's eye lens obtained thereby, and FIG. 3 is a sectional view showing a state in which it is stretched in a uniaxial direction. 4 is a perspective view showing a modified fly's eye lens obtained by these methods, FIGS. 5 and 6 are sectional views showing an example of the uniaxial stretching method of the present invention, and FIGS. 7 to 9 The figure is a graph showing the characteristics of the transmitted light distribution of the fly's eye lens according to the example. Lens type ultraviolet curable resin liquid synthetic resin substrate lens Fig. 7 B 2 Fig. Fig. 74.7 Concave OI Ne 8 Fig. VT self (shi C3,)

Claims (1)

[Claims] A synthetic resin substrate and a lens mold having a mold surface for forming a fly's eye lens are placed opposite each other, an ultraviolet curable resin liquid is interposed between them, and after curing by irradiating ultraviolet rays, the mold is removed. A method for manufacturing a modified fly's eye lens, comprising stretching a synthetic resin substrate on which a rear lens is formed in a uniaxial direction.