WO1997015437A1 - Mold for molding a resin lens and resin lens produced by using the same mold - Google Patents

Abstract

A mold for molding a resin lens for glasses or an optical instrument, and more particularly for precisely molding a concave surface into a non-spherical and/or toroidal surface into a non-spherical and/or toroidal surface such as a hyperboloidal or ellipsoidal surface wherein a cross-sectional configuration of a gasket for the mold can be made constant and wherein only one type of commonly usable gasket is required for respective types of molds. To this end, that surface (A) of the circumferential edge portion of the mold for molding the concave surface that is in contact with the gasket (3) is formed to be in the same plane along the full circumference of the mold, and the height of a surface (B) adjacent to this surface (A) can be changed so that the height (H) of an inner protruding portion (3a) serving as a spacer for the gasket can be constant. In addition, at least two surfaces that are adjacent to the surface (A) are provided so as to improve the sealing performance between the gasket and the mold.

Description

 Description Molding mold for resin lens and resin lens made using this mold

[ Technical field ]

 The present invention relates to a shape of a molding for molding a resin lens and a resin lens made by using the molding.

[Background technology]

 For example, in a plastic spectacle lens, a lens having a power in a normal range is manufactured by a casting polymerization molding method, but a prescription lens manufactured based on a spectacle method, particularly a lens having a strong power. Almost all lenses with both sphericity and astigmatism are manufactured from preliminarily manufactured semi-finished lenses by polishing based on eyeglass prescriptions.

 In this polishing process from a semi-finished lens, rather than polishing both surfaces based on the prescription of the eye, one surface is formed into a surface that does not require polishing and the other surface is formed into an unprocessed surface. Therefore, it is efficient to grind only this unprocessed surface based on the prescription.

An eyeglass lens generally has a meniscus shape, and the concave surface is formed by a mold having an arbitrary simple curvature, and is usually formed as an unprocessed surface of a spherical shape, and the convex surface is a predetermined shape. It is formed by a mold polished with high precision in the shape and curvature of the surface, and is formed on a spherical shaped surface corresponding to the mold surface that does not require polishing. When the eyeglass prescription is determined, the unprocessed concave surface is polished based on the prescription, thereby completing and providing a prescription lens desired by the customer.

 As described above, in order to complete a semi-finished lens as a prescription lens, it is necessary to polish the concave side, and to obtain an aspherical shape such as a hyperboloid or elliptical surface, or the like. Polishing a cylindrical lens that composes a complex toroidal surface requires a variety of complex jigs and tools and requires extremely advanced technology. For this reason, there is the disadvantage that it takes a lot of processing time to obtain a lens with high processing accuracy.In addition, among plastic single focus lenses, semi-finished lenses are polished and processed. The finished prescription lenses are mainly used for special powers outside the range normally produced by lens manufacturers, and the sphericity and astigmatism mainly consist of lenses with fairly high power. is there. Therefore, the lens completed by polishing the concave surface as described above has a considerably thicker peripheral portion, which is not preferable in appearance.

 In addition, both spherical and astigmatic degrees have a spherical shape, and a lens manufactured by polishing has a drawback that spherical aberration occurs.Because of the intensity number as described above, this spherical aberration The problem is even greater.

In particular, plastic lenses with a shape that is extremely difficult to mass-produce technically due to polishing, rather than producing the required complicated shape by polishing each time, Any surface that is complicated in shape, difficult to polish and requires advanced technology, It is more difficult to use a molding surface that does not need to be polished by using a mold that is formed with high precision with a curvature, and it is more difficult to perform polishing, and production yield and processing In terms of time, it is more desirable. In order to overcome such a problem, the present inventor has proposed that the convex surface has an aspherical shape such as a hyperboloidal surface or an elliptical surface, or that the concave surface has a toroidal shape. We tried to make a semi-finished lens molded into a molded lens surface that does not require polishing and has a special surface shape with additional surfaces, and the results were reported in Jpn. Indicated.

 At the practical stage, the resin 4 of the lens material is injected using a mold consisting of a pair of molds 7 and 9 for molding both sides of the lens as shown in Fig. 4 and a gasket 8 connecting the two. In order to improve the sealing performance between the mold 7 and the gasket 8 for molding the concave side of the lens, the molding contact follows the curved surface at the peripheral edge of the molding 7. The gasket 8 was manufactured such that the height H ′ of the contact portion was changed in the circumferential direction and matched with the curved surface E of the mold.

 However, since the gasket requires a mold because it is manufactured by injection molding, a large number of molds are required to match the mold abutting portion to changes in the aspheric surface and Z or toroidal surface of the mold. The need for molds increased the cost, which led to higher lens costs. Also, as shown in Fig. 4, the contact surfaces between the gasket 8 and the mold 7 are only two surfaces, E and F, and there is concern about the adhesion. Is increasing.

Therefore, the present invention solves the above-mentioned problems by improving the shape of a molding mold, and provides a molding die used for casting polymerization molding of a resin lens. The type of gasket, and thus the type and number of molds for gasket molding, are reduced, and the adhesion between the mold and the gasket is improved. It is an object of the present invention to solve the same problem and to reduce the cost of the molded resin lens.

[Disclosure of the Invention]

 The present invention relates to a molding mold for a resin lens molding die comprising a pair of moldings for molding both surfaces of a lens and a gasket for joining both moldings, wherein the surface polished precisely is formed. At least one surface of an aspherical surface such as a hyperbolic surface or an elliptical surface and a no- or toroidal surface, at least one surface of a contact portion of the mold with the gasket, is formed to be the same plane. It is characterized by.

 Thus, the gasket connecting the two molds constituting the molding die can be formed so that the contact portion with the mold has a plane corresponding to the same plane. Therefore, it is not necessary to use a different gasket for each mode, and one and the same gasket can be commonly used for each mode. As a result, the type and number of molds for producing gaskets can be greatly reduced, and lens costs can be reduced.

 In the present invention, the surface of the contact portion between the gasket and the mold may be formed by a surface formed of the same plane and at least two other surfaces adjacent to the surface. Thereby, the surface formed from the same plane and the surface adjacent thereto improve the sealing property between the mold and the gasket, and can thereby prevent generation of bubbles and early release.

Further, in the above, the peripheral edge of the mold is precisely polished. It is preferable that the side of the cut surface is notched so that the surface of the contact portion with the gasket is formed as a stepped surface that forms the same plane and a surface that intersects and is adjacent to the surface. New Thereby, the sealing between the mold and the gasket can be further improved.

 Further, the present invention relates to a molding mold for a resin lens molding die comprising a pair of moldings for molding both surfaces of a lens and a liner interposed between the moldings, The surface polished to form an aspheric surface such as a hyperboloid or an ellipsoid and a no or toroidal surface, and at least one surface of a contact portion of the mold with the liner is at least one plane. It is characterized by being formed.

 Also in this case, it is not necessary to change the liner interposed between the two molds constituting the molding die for each mold, so that the number and types of liners can be reduced, and the cost can be reduced.

 Further, the present invention is characterized by a resin lens for spectacles or optical equipment molded by using the molding mold of each of the above inventions, whereby a cost-effective lens can be obtained.

[Brief description of drawings]

 FIG. 1 is a sectional view showing a relationship between a mold and a gasket according to an embodiment of the present invention.

 FIG. 2 is a partially enlarged view of FIG.

 FIG. 3 is a sectional view of another embodiment of the present invention.

FIG. 4 is a cross-sectional view showing the relationship between a mold and a gasket in a conventional molding die. BEST MODE FOR CARRYING OUT THE INVENTION FIG. 1 is a cross-sectional view of a mold used for casting polymerization of a resin lens, showing one embodiment of the present invention. In the figure, reference numerals 1 and 2 denote a pair of moldings forming both surfaces of the lens, and reference numeral 3 denotes an annular gasket connecting the moldings 1 and 2. Both the molds 1 and 2 are fitted to the gasket 3 from above and below, and are held at a predetermined interval with the inner protruding portion 3 a of the gasket 3 interposed therebetween. Reference numeral 4 denotes a resin of the lens material, which is injected from the injection port 10 of the gasket 3.

 FIG. 2 is an enlarged view of a circle indicated by a dashed line in FIG. The mold 1 has a horizontal edge in the figure by forming a notch from the side of the precisely polished surface 5 that becomes the lens molding surface, as the peripheral portion that comes into contact with the gasket 3 is formed. The stepped surface A is formed so as to be present on the same plane over the entire circumference, and the inner surface B adjacent to the surface A and the outer surface C of the mold are orthogonal to the surface A and the gasket 3. It is set so that it can be pressed lightly.

 Here, the height h of the surface B follows the shape of the aspheric surface such as the hyperbolic surface or the elliptical surface of the precisely polished surface 5 of the mold 1 and the shape of the Z or toroidal surface over the entire circumference of the mold. And change.

 The above configuration is significantly different from the conventional mold in that the surface A and the surface B are provided on the side of the polished surface 5 of the mold 1. Also, the plane A and the plane B do not necessarily need to be perpendicular to each other, but may be any two planes adjacent to each other in the direction of intersection. As a result, the mold 1 and the gasket 3 are in close contact with each other on the three surfaces A, B, and C, and the sealing performance is improved.

The molding surface 6 of the mold 2 has a spherical convex shape based on the optometry. Since the surface of the lens to be polished is molded and a spherical surface having a predetermined radius of curvature may be used, the surface D of the peripheral portion in contact with the gasket 3 must be in the same plane. Become. Therefore, the height H of the inwardly protruding portion 3a serving as a spacer of the gasket 3 is constant.

 That is, the gasket 3 forms a contact portion between the two molds 1 and 2 and a plane corresponding to the plane A and the plane D existing in the same plane of the both molds on the inner protruding part 3a. By doing so, the inner protruding portion 3a can be formed at a constant height H, so that it is not necessary to use a different gasket for each mold.

 Therefore, with the above-described configuration, only one type of die is required when the gasket 3 is injection-molded. In addition, even when considering extreme astigmatism, using only two or three types of molds will not work.

 FIG. 3 shows an embodiment in which the present invention is applied to a mold for injection molding a resin lens.

 In this embodiment, a liner 13 serving as a stirrer is interposed between the upper and lower moldings 11 and 12. The surface A 1 extends over the entire periphery of the contact portion of the mold 11 with the liner 13, that is, around the mold portion 11 a formed on the precisely polished surface 15 as described above. It is formed so as to exist on the same plane, and an inner surface B 1 adjacent to the surface A 1 is formed so as to be orthogonal to the surface A 1. Also in this case, the height h i of the surface B 1 changes along the shape of the aspheric surface and the Z or toroidal surface of the polished surface 15 over the entire circumference of the mold portion 11a.

Mold 12 is polished to a spherical convex surface based on the prescription of optometry. A molding surface 16 for molding the surface to be processed is formed in the mold portion 12a, and around the molding surface 16 which is a contact portion with the liner 13, the surface D1 is the same over the entire circumference. It is formed so as to lie on a plane, and the inner surface G 1 adjacent to the surface D 1 is formed so as to be orthogonal to the surface D 1.

 Therefore, the distance between the surface A1 and the surface D1 of both the molds 11 and 12 is constant, and the thickness T of the liner 13 interposed between them is also constant. Also in this case, it is not necessary to change the liner provided between the moldings constituting the molding apparatus for each molding, and the type and number of liners can be reduced.

 Therefore, by using the molding mold in the molding die of each of the above embodiments, a resin lens for spectacles or optical equipment can be molded at a low cost.

 It should be noted that the present invention can be implemented by configuring the contact portion between the above-described mold and the gasket or the liner in the same manner as described above even when the objective surface side of the lens is aspherical.

[Industrial applicability]

As described above, according to the molding die having the molding mold of the present invention, the molding has a precisely polished surface composed of a non-spherical surface such as a hyperbolic surface or an elliptical surface and a Z or toroidal surface. However, as a gasket to be combined with a mold, one type of the same gasket can be used in common for each mold, and a single type of gasket can be used to cast various lenses. . As a result, only one type of mold is required for injection molding the gasket, which is extremely economical, and is very economical for eyeglasses or optical equipment. Resin lenses can be provided at low cost.

 Also, in the case of a molding die composed of a pair of molds and a liner interposed between the pair of molds, the number of types of the liner can be reduced, and productivity can be improved as described above.

Claims

Scope of the request A mold in a resin lens mold consisting of a pair of molds for molding both sides of the lens and a gasket for joining both molds, and a precisely polished surface Constitutes an aspheric surface such as a hyperboloid or an ellipsoid and a Z or toroidal surface, at least one of the surfaces of the abutment portions of the mold with the gasket is formed on the same plane. A molding for molding a resin lens, characterized in that the surface of the contact portion is formed by a surface formed of the same plane and at least two other surfaces adjacent to the surface. The molding mold for a resin lens according to claim 1, wherein: The side of the polished surface of the peripheral edge of the mold is notched so that the surface of the contact portion with the gasket has a coplanar stepped surface and a surface adjacent to the surface. 3. The molding lens for a resin lens according to claim 1, which is formed. A mold in a resin lens mold consisting of a pair of molds that form both sides of the lens and a liner interposed between the molds, the surface polished precisely being a hyperboloid or ellipsoid And the like, wherein at least one surface of an abutting portion with the liner of the mold is formed on the same flat surface. Lens molding molding K o A resin lens for spectacles or optical equipment molded using the molding mold according to any one of claims 1 to 4.