JPS61132313A - Manufacture of lens for spectacles - Google Patents

Abstract

PURPOSE:To make it possible to produce a lens without requiring cutting and buffing even if it has a great surface such as a diamond cut surface, by melting acrylate pellets followed by injection into a mold under a high pressure to be molded into a lens. CONSTITUTION:Fine acrylate pellets 11 are heated and melted, followed by injection into a mold 12. The mold 12 comprises a master mold 12a and a servant mold 12b, a nozzle 13 is pushed into an injection port 14 and the melt is injected under a high pressure. After the completion of the injection and the cooling, the mold 12 is opened, and the molded lens is removed. If two lens are molded, they are removed with a small leg 15 left on one of them. After annealing for about 1-2hr at a certain temperature, the lens is coated with a coating liquid so that the surface may be hardened.

Description

[Detailed description of the invention] (Industrial use diacritics) The present invention relates to a method for manufacturing eyeglass lenses.

(Prior art) There are eyeglass lenses for nearsightedness, presbyopia, and sunglasses, and even among these, there are colored lenses.
Furthermore, there are many designs and shapes of spectacle frames to which the lenses are attached, and the types of lenses to be attached to the seven frames are diverse. Generally, eyeglass lenses are formed into a circular shape, and the pressed lenses are cut and polished into a predetermined shape so as to fit into the frame of each frame.

By the way, glasses do not just have to function as glasses, but are highly design-oriented, so the frames have various shapes and decorations.In recent years, not only the frames mentioned above but also diamond-cut Lenses with designs such as these are being used. However, such a large diamond cut surface (1) as shown in Figure 1
Even if the lens is made with
The lens must be finished by buffing, which increases the number of processing steps and makes it impossible to produce uniform lenses.

In other words, even if some degree of non-uniformity exists in the external shape, it is covered by the frame and is hardly considered a problem in terms of appearance.
If minute irregularities or undulations exist on the large diamond-cut surface, they can be identified at a glance, and even if a final buff polishing is performed after polishing with a rough puff, the above-mentioned irregularities and undulations cannot be removed. Therefore, the decorative surface has a very negative effect on the design.

(Problems to be solved by the present invention) As described above, for lenses that form a large surface such as a diamond-cut surface, the conventional manufacturing method that involves cutting from a distorted shape and buffing requires very high processing effort. The power of the diamond has been further processed.

The desired quality cannot be obtained from the top surface, which is a very serious problem when used as a decorative cut surface.

The present invention was developed with the aim of solving the above problems, and provides a lens with no variation in size and shape, that is,
To provide a lens that perfectly fits into a frame for eyeglass frames, and a high-quality lens having a decorative lower surface formed by cutting or buffing such as a diamond-cut surface, and sometimes a curved surface.

(Means for solving the problem) When cutting a very hard lens from a distorted mold into a predetermined shape, unevenness in the shape inevitably occurs due to cutter wear and rough buffing. In particular, when cutting a flat surface, the contact area with the cutter is wide, and a very light lens will cause chatter, making it impossible to avoid fine uneven surfaces.

Therefore, the present invention proposes a method of manufacturing lenses by injection molding, in which a predetermined external shape, a decorative cut plane, and sometimes even a curved surface are simultaneously formed. Therefore, in this manufacturing method, fine acrylic pellets are melted and injected into a mold under high pressure, and after cooling for a certain period of time, the mold is opened and the molded lens is taken out.After that, annealing and coating treatments are performed to complete the process. It is.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the eyeglass lens fitting method according to the present invention will be described in detail below with reference to the drawings.

(Example) A lens to be manufactured by the manufacturing method of the present invention has a diamond-cut surface (1) formed on the outer periphery of the lens, as shown in FIG. The diamond-cut surface (1) (force... is formed with a flat surface, and the outer surface of the lens curved with a constant curvature (
2). In addition, the lens forms a convex lens and is used for farsightedness or as reading glasses.
The thickness is also relatively thick, and the outer circumferential surface U) does not have a groove or a convex part that fits into the frame, but uses a hole l)σ), and a restricting hole (Hiro)l)
By attaching a connecting fitting (not shown) to the hole (5) and an end fitting (not shown) to the hole (5), glasses can be constructed without attaching the lens to the 7-contre frame. Further, the lens may be formed with a convex portion (B) like a pyramid in a part as shown in FIG. 6, or a diamond-cut surface (C) may be formed with a smooth concave or convex surface instead of a flat surface.

By the way, such decorative flat surfaces, curved surfaces, and convex portions (g)
To explain the manufacturing method of the lens that forms the lens below, first, we use fine acrylic pellets (
Figure 4(a)). The acrylic pellet (//) is 220
The acrylic that has been heated to between °C and 230 °C and melted into a fluid state is injected into a mold (/2), but the original mold (
/2) consists of a main mold (12&) and an inverted mold (12t+), and the nozzle (/3) is pushed into the injection port (/≠), and from the nozzle (/3) approximately 100 kq/cd to 120
Inject at high pressure of JAZ/LRI. Of course, the above injection pressure depends on the size, thickness, etc. of the molded lens, and is not limited to a positive value. After the injection is completed, the mold (/, 2) is cooled for a while, and then the molded lens is removed by 6 g, but as shown in Figure 4 (C) < 211i1 When molded at the same time, the molded lens is removed, as shown in Figure 4 (D). Separate it leaving a small leg (/j) like this. Some residual strain remains inside lenses molded in this way, and because the interior contains moisture due to the characteristics of acrylic, it is kept at a constant temperature (approximately 75°C).
Annealing is performed for about 1 to 2 hours at ~7'l''C), and the annealed lens is coated with a coating liquid to harden the surface.The legs (15) are then coated with a coating liquid to harden the surface. Use as a holder.

As described above, the method for manufacturing eyeglass lenses according to the present invention targets lenses that form a decorative surface such as a diamond-cut surface, and involves a series of steps that are completed by processing by injection molding, followed by annealing and coating. The following unique effects can be obtained.

(Effects) (1) Unlike the conventional process of cutting and buffing a jade lens into a predetermined shape, the outer shape and decorative surface are formed at the same time, greatly reducing the number of processing steps.

(2) This manufacturing method not only eliminates the traditional puff polishing and reduces the number of steps mentioned above, but also makes the decorative surface extremely elegant, and since the molding is done using the same mold, the quality is uniform, making it possible to improve the quality of the decorative surface compared to the conventional decorative surface. There are no minute irregularities caused by the cutting process.

(3) In addition, when forming a decorative surface by cutting or buffing a distorted mold, the size and shape of the decorative surface are restricted, and it may be difficult to process a decorative surface with an uneven surface, etc. many. However, with the molding according to the present invention, as long as mold processing is possible, molding can be performed without any burden on cost or process, making it possible to provide a very novel lens.

[Brief explanation of drawings]

1 and 2 are examples of eyeglass lenses to be manufactured according to the present invention. FIG. 1 is a front view, and FIG. 2 is an A--
A cross-section is shown in Figure 6 (a) (t+) is a spectacle lens of another form, (a) is a front view, (b) is a cross-sectional view, and Figures 4 (a) to (e,) are Each represents an example of the manufacturing process of the present invention. (1)...Diamond cut surface (2)...Outer surface (,?)...Outer peripheral surface l)σ)...Hole (
6)... Convex part (/ /)... Acrylic pellet (/, 2)"
・■Type (/j)...Fist nozzle (/4Z)Φ・
・・Inlet (／ri・・・・legs)

Claims (2)

[Claims] (1) Heat and melt acrylic pellets as a material, inject the melted acrylic pellets into a mold with a predetermined external shape and decorative surface, cool temporarily after injection, open the mold, and release the molded lens. 1. A method for producing a spectacle lens, which comprises annealing at a predetermined temperature and then coating the outer surface with a coating liquid to produce a spectacle lens having a predetermined outer shape and a decorative surface. (2) The method for manufacturing a spectacle lens according to claim 1, wherein a diamond-cut surface is formed in a part of the decorative surface.