JPH10300904A - Manufacture of prism lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new method for manufacturing a prism lens, to eliminate the need to manufacture and use a metal mold for injection molding of a synthetic resin material like conventional technologies, and to speedily and easily manufacture the prism lens at low cost without causing material defects peculiar to infection moldings. SOLUTION: An ultraviolet-ray setting ink(UV ink) lens element 5 is printed on the surface of a transparent plate type adhered body 4 by using a screen 1 for screen printing. The printed lens element 5 naturally becomes hemispherical because of its surface tension and functions as a piano-convex lens. The UV ink in the desired shape is irradiated with ultraviolet rays to set, so that the prism lens is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of industrially producing a prism lens using a special printing technique.

[0002]

2. Description of the Related Art Prism lenses are widely used for lamps, ornaments, traffic lights, sign boards, and the like. FIG. 4 is a partial cross-sectional perspective view illustrating an example of the prism lens, which is cut and drawn on a plane perpendicular to the plate-like portion. Prism lens 6 of this example
Has a shape in which a number of plano-convex lens elements 6b are arranged side by side in a matrix on the surface of a plate-like portion 6a, and is integrally formed of a transparent synthetic resin material. Although not shown, there is an example in which lens elements are arranged diagonally (so-called staggered arrangement).

[0003]

When a prism lens as shown in FIG. 4 is industrially produced, a method of molding a synthetic resin material using a mold has conventionally been generally used. In order to perform molding using the above-described mold, a mold must be made that matches the type and size of the prism lens to be manufactured. The mold is very expensive because its production requires a high level of technology and great effort.
Therefore, in the case of multi-model production, the burden of mold cost is heavy. The present invention has been made in view of the above circumstances, and has as its object to provide a method for manufacturing a prism lens with high efficiency without using a mold or an injection molding device.

[0004]

The basic principle of the method of the present invention created to achieve the above object will be briefly described with reference to FIG. 1 corresponding to one embodiment of the present invention. A mesh portion 1b corresponding to the planar shape of the lens element is formed on the screen 1, and an ultraviolet-curable ink (abbreviated as UV ink) 2 is spread by a squeegee 3 to form the above-mentioned on a transparent plate-shaped adherend 4. A small block of ultraviolet curable ink having the same shape as the mesh portion 1b is formed. The small lumps become hemispherical due to surface tension. When the hemispherical ultraviolet curable ink is irradiated with ultraviolet rays and cured, a hemispherical lens element 5 is formed. The method according to the first aspect of the present invention is based on the principle described above. The method according to claim 1, wherein a lens element is screen-printed on a surface of a transparent plate-shaped adherend using a UV-curable transparent ink, and the printed UV-curable By applying and curing ultraviolet rays in a state where the hydrophilic ink has a hemispherical shape due to surface tension, the lens element having a hemispherical shape or a shape similar to the hemispherical shape is fixed to the surface of the adherend. Features.

According to the above-described method of the present invention, the ultraviolet curable ink is printed in the form of a lens element by screen printing without using a mold, and the surface of the printed ultraviolet curable ink itself is printed. By irradiating and curing ultraviolet rays in a state of being formed into a hemispherical shape by tension, a prism lens can be quickly and easily formed. Since this method can be carried out without preparing a mold, even in the case of multi-model production, the setup can be easily changed, and can be dealt with only by replacing the screen for screen printing. Since this method applies screen printing technology, equipment costs and running costs are low, and unlike the synthetic resin injection molding in the prior art, high temperatures and high pressures are not used, which is safe and work efficiency is low. In addition to being high, there is no danger of causing material defects such as sink marks, skin spots and residual stress as in synthetic resin molded products, and the product failure rate is low. Moreover, there is no possibility that a shape defect such as a burr is generated as in the case of a synthetic resin molded product, so that an operation corresponding to the finishing of the molded product is not required.

According to a second aspect of the present invention, in addition to the constitutional requirements of the first aspect, the planar shape of the lens element is circular, triangular, polygonal, or similar. In the case of a circle, the diameter is 5 mm or less, in the case of a triangle, the diameter of the circumscribed circle is 5 mm or less, and in the case of a polygon, the length of the maximum diagonal is 5 mm or less. According to the above-described method of the second aspect of the invention, the contour dimension of the planar shape corresponding to the lens element of various shapes is not excessively large. If the shape and dimensions of this lens element are excessive, it becomes difficult for the ultraviolet curable ink in a screen printed state to maintain a hemispherical three-dimensional shape due to surface tension, and the lens element to be a plano-convex lens is shaped like a plano-concave lens. However, when the outline (that is, the printing shape) of the planar shape is regulated by applying the present invention, the screen-printed ultraviolet curable ink becomes a beautiful hemisphere due to surface tension. This hemispherical surface is formed not by engraving the mold artificially but by balancing the forces of natural physical properties, so that no labor is required, and there is a risk that artificial mistakes and errors are mixed. Without any trouble, it is automatically finished to the correct shape.

According to a third aspect of the present invention, in addition to the constitutional requirements of the first aspect, a plurality of lens elements are vertically, horizontally and / or diagonally arranged on the surface of one adherend. It is characterized by. According to the method of the third aspect described above, a wide variety of products (prism lenses) are formed by arranging single-shaped lens elements or lens elements of various shapes in a matrix in a matrix, or in a staggered diagonally. ), And has a high degree of design freedom,
The degree of freedom in design is also large. Although it is not impossible to manufacture such a variety of prism lenses by the conventional technique, the cost of manufacturing the mold is high and it is difficult to use the lens for practical use. Claim 3 makes use of the characteristics of the manufacturing method according to the present invention,
This makes the production of various prism lenses practical.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a prism lens according to the first aspect, wherein the lens element is screen-printed on the front surface of the adherend before or after the lens element is screen-printed. In addition, a color transparent thin film is formed in advance, or a color transparent thin film is formed on the back surface of the adherend after the lens element is screen-printed. According to the method of claim 4 described above,
A prism lens having any desired color tone can be manufactured using a colorless ultraviolet curable ink. For this reason, not only the degree of freedom in selecting a color tone is large, but also symbols, characters, patterns, and the like can be easily displayed according to the color tone. Even when producing prism lenses of various colors, there is no need to convert screens and inks, so that process control is easy, production efficiency is high, and industrial productivity is excellent.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a prism lens according to the second aspect of the present invention, wherein the lens is cured by ultraviolet irradiation of an ultraviolet curable ink printed on the surface of the adherend. The device is characterized in that the dimension of the element protruding and protruding from the surface of the adherend is equal to or more than 200 microns. When the method according to claim 5 described above is applied to the method according to claim 2, on the one hand, the upper limit of the planar shape and size of the lens element is regulated, and on the other hand, the three-dimensional bulging protrusion of the lens element. By regulating the lower limit of the dimension, it is possible to secure a diopter (reciprocal of the focal length) for the lens element to function effectively, and to increase the practical effect.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic sectional view showing one embodiment of a method for manufacturing a prism lens according to the present invention. FIG. 1 (A) shows a screen and its accompanying materials. (B) shows a state in which a hemispherical lens element is screen-printed on a surface of a transparent plate-shaped adherend using an ultraviolet-curable ink to facilitate the process. . Since the basic configuration related to the screen printing technique is publicly known, details thereof are omitted, and points different from the prior art (that is, matters changed by applying the present invention) will be described in detail below. 1 shown
a is a medium portion of the screen 1, and 1b is a mesh portion. There are no particular restrictions on the constituent materials of the screen. In this embodiment, a stainless plate was used.
The planar shape of the mesh portion 1b is formed in the same manner as the contour of the planar shape of the lens element to be formed. The details will be described later in detail with reference to FIG.

An ultraviolet curable ink (abbreviation: UV ink) is supplied onto the screen 1, and the squeegee 3 is moved in the direction of arrow a to spread the UV ink 2. In FIG. 1, the portion (A) and the portion (B) are drawn vertically separated from each other. However, when the UV ink 2 is spread by the squeegee 3 as described above, the screen 1 is covered with a transparent plate. It is carried out while being held parallel to the body 4 with a spacing dimension of 1.5 to 2.0 mm. The material of the transparent plate-shaped adherend 4 is:
There is no harmful chemical reactivity to UV ink 2, and
It is necessary that the balance between the adhesion to the UV ink 2 and the surface tension is appropriate, and that the printed UV ink be a hemispherical surface or a transparent material having a surface shape similar to a hemispherical surface. Even if the material has a surface tension that is too large and is almost spherical, it is useful, but the lens element and the adherend do not adhere firmly. In addition, a hemispherical lens element is not formed with a material having an adhesive force that is too large (wetting property is too good) compared to the surface tension.

The balance between the surface tension and the adhesive force described above is a problem determined by the combination of the UV ink 2 and the adherend 4. However, since the surface properties of the UV ink 2 are limited, the range of selection is narrow. The material of the transparent plate-shaped adherend 4 is U
It is practical to choose according to the V ink. If the above selections are appropriate, the printed lumps of UV ink form a hemispherical lens element 5 as shown in FIG.
When irradiated with ultraviolet light and cured, it becomes a prism lens as a product.

FIG. 2 is a front view showing three examples of the prism lens manufactured by the method of the present invention.
FIG. 1B shows a state in which a large number of lens elements are arranged on the surface of the transparent plate-like member shown in FIG. 1B, and also shows a mesh portion formed on the screen shown in FIG. 2A shows a state in which circular lens elements are arranged, FIG. 2B shows a state in which triangular lens elements are arranged, and FIG. 2C shows a state in which quadrangular lens elements are arranged. , (D) shows a state in which various lens elements are arranged,
Each is represented. Polygonal lens elements other than the above-described triangles and quadrangles can be configured, and their arrangement may be vertical and horizontal, or may be staggered vertical and oblique. In addition, a plurality of types of lens elements may be arranged, and in addition, they may be arranged to represent characters, symbols, and figures. By using such various screens, setup change for configuring different types of lens elements can be performed quickly and easily.

FIG. 3 is a cross-sectional view for explaining a state in which a lens element is formed on the surface of a transparent adherend. FIG. 3A shows a state in which a relatively small lens element is formed. , (B) are drawn so that lens elements having an excessively large planar shape can be compared with each other. The lens element 5d having a relatively small diameter tends to form a hemispherical shape due to surface tension, whereas the lens element 5e having a large diameter tends to have a concave top surface. In order to prevent such a problem, in the case of a circular lens element, it is desirable to set the diameter φ to 5 mm or less. When the diameter 越 え る exceeds 5 mm, the lens does not have a plano-convex lens shape as shown in FIG.
As shown in (B), the shape tends to be similar to a plano-concave lens.
By setting the diameter φ to 5 mm or less and the bulging height h of the lens element to 200 μm or more as shown in FIG. 3A, the hemispherical shape of the lens element becomes an appropriate curvature, andヂ optical (reciprocal of the focal length) is obtained. In the above description, the diameter dimension φ of the circular lens element was described. However, in the case of a triangular lens element, the diameter dimension of the circumscribed circle may be set within 5 mm, and in the case of a square lens element, the length of the diagonal line The size may be set so as to be within 5 mm. In the case of an irregular square or other polygon having a plurality of diagonal lines, the length of the largest diagonal line is set to be within 5 mm. In the case of having a contour of a curved shape similar to a polygon, it is desirable to experimentally determine the above-mentioned standard as a guide.

It is obvious that the adherend 4 and the cured UV ink in the present invention must be made of a transparent material as a constituent member of the prism lens, but two examples of a method of manufacturing a colored transparent prism lens are described below. Is described below. As shown in FIG. 3 (A), the surface of the transparent adherend 4 (the surface constituting the lens element) is previously colored with a transparent printing ink with a desired character, symbol, figure, or pattern. After forming the transparent film 7a, the lens element 5d is formed by screen printing as described above. The above-described printing using the colored transparent printing ink may be performed on the back surface of the transparent adherend 4 to form the colored transparent film 7b. When the colored transparent film is formed on the back side (the side opposite to the lens element), it may be performed before or after screen printing for forming the lens element.

The working conditions when a circular lens element having a diameter of about 5 mm is constructed in the present embodiment are as follows. However, the following is one example, and the present invention is not limited to this. (A) Composition of UV curable ink A UV resin containing 94% of urethane acrylate, 3% of a photoreaction initiator, and 3% of an auxiliary (all by weight) was used.

(B) Viscosity of UV-curable ink BH-type rotational viscometer 2 rpm ... 450p 4rpm ... 450p 10rpm ... 450p 20rpm ... 440p Splat meter value 1 minute value ... 21.5 (c) Screen printing conditions Squeegee pressure ... 3 to 4.5 kg / cm Squeegee speed 20 to 30 cm / sec Number of meshes 80 to 100 mesh (d) Curing condition UV energy density 80 to 100 w / cm ² UV lamp specification … Metahara lamp (2 lamps) Speed of the irradiated object… 10m / 60sec

[0018]

As described above, according to the embodiment of the present invention, the lens element is formed by screen printing without using a mold according to the method of the present invention. Therefore, even in the case of multi-model production, the setup can be easily changed, and can be dealt with only by changing the screen for screen printing. Since this method uses screen printing, the equipment cost and the running cost are low, and there is no risk of causing material defects as in the synthetic resin molding in the prior art. In addition, there is no possibility that a shape defect such as a burr is generated as in a synthetic resin molded product, and an operation corresponding to finish processing of the molded product is not required.

According to the method of the present invention, an appropriate planar shape can be set corresponding to lens elements of various shapes, and a beautiful hemispherical lens element can be formed. The hemisphere is not formed by engraving the mold artificially, but is formed by balancing the forces of natural physical properties, so no labor is required and there is no risk of mixing in human errors and errors. , Automatically finished to the correct shape.

According to the third aspect of the present invention, a wide variety of products (prism lenses) can be formed by arranging lens elements, and the design and design degrees of freedom are large, and various prism lenses can be used. Make manufacturing practical. According to the method of claim 4, a prism lens having any desired color tone can be manufactured using a colorless ultraviolet curable ink. Even when manufacturing prism lenses of various colors, there is no need to change screens and inks, so that process control is easy, manufacturing efficiency is high, and industrial productivity is excellent. When the invention method of claim 5 is applied to the invention method of claim 2, on the one hand, the upper limit of the planar shape and size of the lens element is restricted, and on the other hand, the lower limit of the three-dimensional bulging protrusion dimension of the lens element is reduced. By regulating, it is possible to secure a diopter (reciprocal of the focal length) for the lens element to function effectively, and to increase the practical effect.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing one embodiment of a method for manufacturing a prism lens according to the present invention. FIG. 1 (A) depicts a screen and its accompanying materials. The thickness dimension is enlarged, and (B) shows a state in which a hemispherical lens element is screen-printed on the surface of a transparent plate-shaped adherend using an ultraviolet curable ink.

FIG. 2 is a front view showing three examples of a prism lens manufactured by the method of the present invention, in which a large number of lens elements are arranged on the surface of the transparent plate member shown in FIG. FIG. 2A shows a state in which circular lens elements are arranged, and has the same shape as the mesh portion formed on the screen shown in FIG. 1A described above. (B) shows a state where triangular lens elements are arranged, (C) shows a state where square lens elements are arranged,
(D) shows a state where various lens elements are arranged.

3A and 3B are cross-sectional views illustrating a state in which a lens element is formed on the surface of a transparent adherend. FIG. 3A illustrates a state in which a relatively small lens element is formed, and FIG. The parentheses are drawn so that the lens elements having an excessively large planar shape can be compared with each other.

FIG. 4 is a partial cross-sectional perspective view illustrating an example of a prism lens, which is cut and drawn on a plane perpendicular to a plate-like portion.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Screen for screen printing, 1a ... Medium part of screen, 1b ... Mesh part of screen, 2 ...
UV curable ink (abbreviation: UV ink), 3 ... squeegee for screen printing, 4 ... transparent plate-shaped adherend, 5 ...
Lens element, 5a: circular lens element, 5b: triangular lens element, 5c: square lens element, 5d: small-diameter lens element, 5e: large-diameter lens element, 6: prism lens, 6a: plate-shaped part, 6b ... lens element, 7a, 7b ...
Colored transparent film.

Claims (5)

[Claims] 1. A lens element is screen-printed on a surface of a transparent plate-shaped adherend using a UV-curable transparent ink, and the printed UV-curable ink forms a hemispherical shape due to surface tension. A method of manufacturing a prism lens, comprising: fixing a lens element having a hemispherical surface or a shape similar to a hemispherical surface to the surface of the adherend by irradiating and curing ultraviolet rays in a state where the prism lens is in a state of being applied. 2. The lens element according to claim 1, wherein the planar shape of the lens element is a circle, a triangle, a polygon, or a shape similar thereto, wherein the diameter is 5 mm or less for a circle, and the diameter of a circumscribed circle for a triangle. 2. The method according to claim 1, wherein the length of the longest diagonal line is 5 mm or less in the case of a polygon. 3. The method for manufacturing a prism lens according to claim 1, wherein a large number of lens elements are vertically, horizontally and / or diagonally arranged on the surface of one adherend. 4. Prior to screen-printing a lens element on the surface of the adherend, a colored and transparent thin film is previously formed on the front or back surface of the adherend, or the lens element is screen-printed. 2. The method for manufacturing a prism lens according to claim 1, wherein a colored transparent thin film is formed on the back surface of the adherend. 5. In a state where the ultraviolet curable ink printed on the surface of the adherend is cured by irradiation with ultraviolet light,
3. The method of manufacturing a prism lens according to claim 2, wherein the dimension of the lens element protruding and protruding from the surface of the adherend is made equal to or more than 200 microns.