JPS59187316A - Multiple focus lens - Google Patents

Abstract

PURPOSE:To obtain a multiple focus lens which facilitates variation in focal length, restoration, and movement of a variation part by making a detachable lens made of soft synthetic resin adsorbed to a part of the lens. CONSTITUTION:The lens 2 made of soft synthetic resin differs in focal length from the lens 1 of a main body. In order that this lens 2 is made contact to the lens 1 of the main body tightly, the radius of curvature of the side where the lens of soft synthetic resin tightly contacts with the main body lens should be a little bit smaller than that of the main body lens, but almost neither distortion of an image nor variation in degree due to the suction is recognized within a >=1mm. maximum interval DELTAH of the gap formed between the lens 2 and main body lens 1. Thus, this multiple focus lens facilitates the attachment and detachment of the lens for varying the focal length locally, and the attachment position is selected optionally.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multifocal lens having a plurality of focal points with partially different focal lengths.

Glasses for nearsightedness, farsightedness, presbyopia, etc. are used to correct vision, but once a person reaches the age of 40 or 45, it becomes clear whether the person was nearsighted, farsighted, or emmetropic. (Presbyopia occurs, and the ability to accommodate decreases with age.)
Therefore, people with nearsightedness or farsightedness must carry glasses for farsightedness in addition to glasses for nearsightedness or farsightedness, and use them depending on the purpose. It is extremely inconvenient.

In order to solve this problem, we developed bifocal lenses that correct distance vision, near vision, and trifocal lenses that correct distance vision, intermediate vision, and near vision with one lens.
Multifocal lenses such as progressive lenses that change the focal length continuously from distance to near vision have been developed and are in wide use. However, in these multifocal lenses, the The geometric and optical position is predetermined by the manufacturer, and once you use Ceratos as a pair of glasses, you cannot change that position.For this reason, for example, if you set the near part for reading, In this case, it would be inconvenient to look up at something on the shelf with the near part of the body.

In order to solve this problem, it is sufficient to attach a lens having a focal length necessary for viewing the desired object to a commonly used spectacle lens at an appropriate position. Japanese Utility Model Application Publication No. 54-33653 proposes using flexible plastic lenses for vision correction by adhering them to lenses with an adhesive or adhesive.

However, when adhesive is used, it is difficult to remove and cannot be reused. Also, if it does not stick well, it will be difficult to redo it. Furthermore, if an adhesive is used, the lens will become dirty due to the adhesive sticking out, and the adhesive cannot be easily removed, so this is not a practically preferable method.

An object of the present invention is to provide a multifocal lens in which the focal length of a part of the lens can be temporarily changed to a desired focal length, and the focal length can be easily changed and restored, and the focal length changing part can be easily moved. .

The multifocal lens according to the present invention is a lens characterized in that a removable soft synthetic resin lens is attached to a part of the lens.

In a preferred embodiment of the multifocal lens according to the present invention, the soft synthetic resin lens has a focal length different from that of the main body lens.

In another preferred embodiment of the multifocal lens according to the present invention, the maximum gap between the soft synthetic resin lens and the lens of the main body is 1 mm or less, particularly preferably 0-5 mm or less.

In yet another preferred embodiment of the multifocal lens according to the present invention, the soft synthetic resin is transparent silicone rubber,
The synthetic resin is selected from the group consisting of vinyl chloride resin, vinylidene chloride resin, epoxy resin, zotyral resin, vinyl acetate resin, ionomer resin, polyester resin, and copolymers of these resins.

In the multifocal lens of the present invention, the soft synthetic resin lens is brought into close contact with the main lens by adsorption, so the radius of curvature of the soft synthetic resin lens on the side that comes into close contact with the main lens is the same as the curvature of the main lens. The radius of curvature of the main lens varies significantly depending on the visual acuity of the user, so the radius of curvature of a soft synthetic resin lens cannot be unambiguously limited, but If the value of the maximum interval △H between the synthetic resin lens 2 and the lens 1 of the main body in the shape P2 is less than 1, there will be distortion of the image due to the distortion due to adsorption and the change in the power from the set power due to the change in the curve. Almost no changes are observed.

The soft synthetic resin lens in the multifocal lens of the present invention can be manufactured by various methods such as cast polymerization molding, injection molding, compression molding, transfer molding, and spin-cast molding, depending on the properties and form of the synthetic resin used. be able to.

For example, when manufacturing lenses with silicone rubber, the second
In a mold consisting of a concave surface mold 3 and a convex surface mold 4 as shown in the figure,
A mixture of raw silicone rubber and a curing agent is poured into the mold and polymerized by casting. Lenses made of silicone rubber can also be manufactured by other methods such as extrusion molding and compression molding.

In the multifocal lens of the present invention, the number of soft synthetic resin lenses to be adsorbed to the main body lens is not limited to one, and a plurality of soft synthetic resin lenses can be adsorbed as desired.
The suction position can also be changed freely depending on the user's purpose.

Next, the multifocal lens of the present invention will be described in more detail based on examples.

Example 1 Concave curvature radius R1 = 92 mvt as shown in Fig. 6
A silicone rubber for casting (manufactured by Shin-Etsu Silicone Co., Ltd., trade name KE-106LTV) was placed in a mold consisting of a concave mold 3 having a radius of curvature of 65 mm and a convex mold 4 having a convex radius of curvature R2 = 65 mm.
Vulcanizing agent (manufactured by Shin-Etsu Silicone Co., Ltd., trade name Catal)
yst RG) plus 'i Mt, 70
It was heat-treated at °C for 4 hours and taken out from the bottle.

The silicone rubber lens taken out from the mold was densely layered on a lens having a convex radius of curvature of 95 rtan by adsorption.

When this lens was measured with a lens meter, the addition power was 2.
It had sufficient performance as a 46D bifocal lens.

A wear test was conducted for 10 days, and no abnormalities were observed during the test period, and the silicone rubber lens did not peel off. After 10 days, the silicone rubber lens could be easily removed from the main lens by pinching the periphery with your fingers, and no traces of removal remained.This is an effect that cannot be seen with adhesive bonding methods. be.

Example 2 A polyvinyl chloride resin lens was manufactured by injection molding using a mold having a convex radius of curvature of 61 mm and a concave radius of curvature of 92 mm.

This lens was brought into close contact with the lens of the same body as in Example 1 by suction, and measurements were taken using a lens meter. This lens had sufficient performance as a bifocal lens with an addition power of 2.78 D.

No peeling occurred during wearing, and the polyvinyl chloride resin lens could be easily removed after use in the same manner as in Example 1. No traces of removal remained, and this was significantly superior to the conventional technology shown in the next comparative example.

Comparative Example The polyvinyl chloride lens used in Example 2 was adhered to the same lens body as in Example 2 using a rubber adhesive.

Since the adhesive was used to adhere the parts, the adhesive sometimes overflowed and bubbles were mixed in during the bonding process.Although the adhesive was reapplied several times, it was difficult to wipe off the adhesive and it was not an easy method. Furthermore, it was necessary to wipe off the adhesive after peeling off the polyvinyl chloride lens, making repeated use difficult.

As described above, the multi-chamber focal lens according to the present invention allows easy attachment and detachment of the lens in order to partially change the focal length, allows the attachment point to be arbitrarily selected, and is free from the effects of distortion and curve changes. There aren't many. In addition, unlike adhesives or adhesives, there is no need for the adhesive or adhesive to protrude or remove the adhesive or adhesive after removing the lens, and both lenses can be used repeatedly, making it practical. Great value.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an embodiment of the multifocal lens of the present invention, Fig. 2 (a, l, and (1)), and Fig. 6 is a cross-sectional view of a soft synthetic resin lens of the multifocal lens of the present invention. FIG. 3 is a cross-sectional view of different embodiments of molds manufactured by the molding method. 1... Lens of main body, 2... Lens made of soft synthetic resin, 3... Mold for concave surface, 4... Mold for convex surface. Representatives: Asamura and Karugai 4 people Figure 1 Figure 2 Figure 3

Claims (3)

[Claims] (1) A multifocal lens characterized by having a removable soft synthetic resin lens attached to a part of the lens. (2) The multifocal lens according to claim 1, wherein the maximum distance between the gaps formed by the soft synthetic resin lens and the lens of the main body is 1 mm or less. (3) The soft synthetic resin is transparent silicone rubber,
Vinyl chloride resin, vinylidene chloride resin, epoxy resin,
Butyral resin, vinyl acetate resin, ionomer resin,
The multifocal lens according to claim 1 or 2, which is a synthetic resin selected from the group consisting of polyester resins and copolymers of these resins.