GB2284679A

GB2284679A - Anti-fog swimming goggles

Info

Publication number: GB2284679A
Application number: GB9325158A
Authority: GB
Inventors: Herman Chiang
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-12-08
Filing date: 1993-12-08
Publication date: 1995-06-14
Also published as: GB9325158D0

Abstract

An eyepiece for an anti-fog swimming goggles includes a lens unit 41 having an outer lens 410 and an inner lens 411 separated by a gap 45 that contains trapped air and which is mounted within a lens receiving space of a frame 40. The double lens prevents condensation. The outer lens may be of polycarbonate and bear an anti-scratch or metal coating. The inner lens may be cellulose acetate and have anti-fogging, polarising and/or photochromic properties. <IMAGE>

Description

EYEPIECE FOR AN ANTI-FOG SWIMMING GOGGLES This invention relates to an eyepiece for an antifog swimming goggles, more particularly to an eyepiece for an anti-fog swimming goggles which has a lens unit that includes an outer lens and an inner lens. The outer and inner lenses respectively undergo many kinds of optical function treatment processes and can provide an excellent anti-fog effect.

Fogging of the lens of a conventional pair of swimming goggles occurs due to the presence of a large temperature difference between the inner and outer surfaces of the lens when the swimming goggles are worn. To solve the aforementioned problem, three methods are commonly employed: 1. A Cellulose Acetate sheet which has undergone anti-fog treatment is used to form an eyepiece of a conventional pair of swimming goggles. Referring to Fig. lA, an anti-fog sheet (10) having a thickness between lmm and 1.5mm is punched to form a lens (11).

The lens (11) is inserted into a mold so as to inject a frame (12) that is molded integrally with the lens (11), thereby forming an eyepiece (13).

Referring to Fig. 1B, the Cellulose Acetate anti-fog sheet should be flat. Furthermore, the frame (12) must be formed with an engaging groove (121) for receiving the lens (11), thus limiting the style of the eyepiece (13).

2. Referring to Fig. 2A, an anti-fog film (20), which has a thickness between 0.125mm and 0.25mm and which has undergone anti-fog treatment, is punched to form a desired lens configuration (21). Either side of the film (20) can be provided with adhesive so that the film (20) can be attached to the internal surface of a lens of an eyepiece, thereby resulting in an anti-fog eyepiece. The film (20) does not limit the style of the eyepiece. However, the process effects are unstable since the adhering process cannot be accomplished conveniently.The drawbacks which are associated with the use of the film (20) are as follows: Referring to Fig. 2B, a pneumatic device (23) having a resilient spherical head (24) is used to impact instantaneously the film (20) so as to expel the air between the film (20) and the internal surface of the lens in order to achieve a firm contact between the film (20) and the internal surface of lens. Thus, it is possible that the film (20) will not adhere on the desired sticking position. Furthermore, it is also possible that the periphery of the film (20) will adhere onto the internal surface of the lens before the air can be expelled entirely, thereby resulting in airfilled bubbles and crack marks. In addition, the periphery of the head (24) of the pneumatic device (23) may be damaged after a period of use so that the periphery of the film (20) will not adhere securely.

Thus, an air aperture, which is invisible to the naked eye, may be formed. The air aperture permits water to permeate therein, thereby causing the untimely removal of the film (20) from the lens surface.

3. Referring to Fig. 3, an anti-fog coating treatment is conventionally achieved by spraying a mixture of anti-fog solution on the internal surface of the lens by means of a prescribed nozzle (30). The outer appearance of the swimming goggles is not limited when this treatment is used.

The aforementioned are the most popular anti-fog treatments used in the manufacture of an eyepiece for a swimming goggles. Both anti-fog sheet and film can be applied only to planar lens surfaces. The anti-fog coating, however, can be applied to any lens configuration. Nevertheless, the anti-fog coating process suffers from the following drawbacks: (a) The anti-fog coating treatment must take place in an air-conditioned room in which the room temperature and relative humidity are precisely controlled. Moreover, after mixing resin and curing agents by the prescribed ratios, the resulting solutions have an expiration date and are moisture sensitive.

(b) Since the anti-fog solution is water-soluble, the anti-fog effectiveness of the cured coating will decrease slightly after prolonged exposure to water.

(c) Most quality optical lenses are made from tough, durable resin so as to provide shatter resistance. In order to reduce "stress crazing" and/or ',craze", the anti-fog treated swimming goggles is air dried and is placed in an oven at a prescribed temperature of 115 C for one and half hour. The multi-curing process thus attacks the resin to weaken considerably the same.

Furthermore, recent developments in the field of swimming goggles have shown that an anti-fog lens can be upgraded by further treatment, such as by hardcoating, metalization, polarizing, gradating, etc., so as to enhance appearance and functionality of the same.

However, the anti-fog sheet cannot undergo metalized treatment and is insufficiently hard to resist scratching. As for the anti-fog film process, the injected-lenses cannot undergo polarizing and/or gradating. Moreover, remnants of chemical will be left on the lens surface when the injected-lenses undergo hard-coating and/or metalizing. This can result in difficulty when securing the anti-fog film on the lens surface. The anti-fog coating usually exhibits less adhesion to hard (abrasion-resistance) coated lenses, but hard coatings can be applied over the anti-fog coating without undesirable side effects. Obviously, anti-fog activity is lost when over-coating with a hard finish occurs. It is clear that an individual coating on either side of the lens is required to come up a multi-functional lens, such as anti-fog with antiscratch, anti-fog with metalization, etc.In addition, the hard coating reacts with the metalization coating, thereby diminishing the intended functions of both coatings.

An object of the present invention is to provide an eyepiece for a pair of swimming goggles that can reduce the temperature difference between the inner and outer surfaces of a lens unit thereof in order to provide an excellent anti-fog effect.

Another object of the present invention is to provide an eyepiece for a pair of swimming goggles that can be made to undergo a plurality of different optical lens treatment processes, such as hard-coating, metalization, polarizing, gradating, etc.

According to this invention, an eyepiece for an anti-fog swimming goggles includes a frame which is provided with a lens receiving space, and a lens unit received in the lens receiving space. The lens unit includes an outer lens and an inner lens. The outer and inner lenses cooperatively define a gap that contains trapped air therebetween.

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment, with reference to the accompanying drawings, of which: Fig. 1A is a flow diagram illustrating the fabrication of an eyepiece of a conventional pair of swimming goggles; Fig. 1B is a sectional view of the eyepiece in Fig.

lA; Fig. 2A is a flow diagram illustrating the fabrication of an eyepiece of another pair of conventional swimming goggles; Fig. 2B illustrates the fabrication of the eyepiece in Fig. 2A with the use of a pneumatic device; Fig. 3 illustrates how an eyepiece for still another pair of conventional swimming goggles undergoes an anti-fog coating treatment process; Fig. 4 is a sectional view showing a pair of antifog swimming goggles according to the present invention; and Fig. 5 is a sectional view showing how an outer lens and an inner lens are joined during a heat-melt operation to form the lens unit of the swimming goggles of the present invention.

With particular reference to Fig. 4, it will be noted that the goggles comprises two eyepieces with a frame (40) and a lens unit (41), a gasket (42), a nosebridge (43) and a head strap (44).

The frame (40) is provided with a lens receiving space. The gasket (42), the nose-bridge (43) and the head strap (44) are formed and are mounted on the frame (40) in a conventional manner.

The lens unit (41) includes an outer lens (410) and an inner lens (411) and is received in the lens receiving space. The outer lens (410) is made from an impact resistant resin. In the present embodiment, the impact resistant resin is Polycarbonate, although Cellulose Acetate may also be used. The inner lens (411) is an anti-fog sheet. The outer and inner lenses (410,411) cooperatively define a gap (45) therebetween.

The gap (45) has a width of about 0.6mm. Trapped air in the gap (45) between the outer and inner lenses (410,411) serves to prevent a large temperature difference between the surfaces of the lenses (410,411) when the goggles is in use, thereby enhancing the antifogging characteristic of the present invention.

The outer lens (410) can be processed with hardcoating, metalization and/or gradating. The hardcoating lens provides an anti-scratch feature.

Moreover, the metalized lens is anti-glare to prevent water reflection. Furthermore, the gradating lens can reflect harmful light and can enhance the aesthetic appeal of the goggles.

The inner lens (411) can undergo regular anti-fog treatment and/or either photochromic or polarizing with anti-fog treatment. Moreover, the photochromic antifog lens can adjust light to a dark tint and back again in accordance with the amount of UV to which it is exposed. Furthermore, the polarizing anti-fog lens screens up to 100% of reflected light, making it ideal for changing light conditions.

The lenses (410,411) and the frame 40 are processed separately and are welded together during sonic welding operation to form a single unit quickly and efficiently. Alternatively, the outer and inner lenses (410,411) can be joined together during a heat-melt operation, as shown in Fig. 5, to be followed by a sonic welding operation to join the lenses (410,411) and the frame 40. The outer lens (410) has a flange portion (4101) formed at the outer edge thereof at a location away from the nose bridge (43). The flange portion (4101) is then heated and crimped toward the inner lens (411) so as to prevent disengagement of the inner lens (411) from the outer lens (410). The crimped flange portion is shown in Fig. 5 by the phantom lines. The method to be used in joining the outer and inner lenses (410,411) to the frame 40 would depend on what materials are employed to form the same.

The combination of the heat-melt and sonic welding operations ensures that a higher quality finished product can be attained.

Claims

1. An eyepiece for an anti-fog swimming goggles, said eyepiece including a frame which is provided with a lens receiving space, and a lens unit received in said lens receiving space, wherein the improvement comprises: said lens unit including an outer lens and an inner lens, said outer and inner lenses cooperatively defining a gap that contains trapped air therebetween.

2. An eyepiece for an anti-fog swimming goggles as claimed in Claim 1, wherein said gap has a width of about 0.6mm.

3. An eyepiece for an anti-fog swimming goggles as claimed in Claim 1, wherein said outer lens is made of an impact resistant material.

4. An eyepiece for an antifog swimming goggles as claimed in Claim 3, wherein said impact resistant material is cellulose acetate.

5. An eyepiece for an anti-fog swimming goggles as claimed in Claim 3, wherein said impact resistant material is polycarbonate.

6. An eyepiece for an anti-fog swimming goggles as claimed in Claim 3, wherein said inner lens is made from a cellulose acetate sheet which had undergone anti-fog treatment.

7. An eyepiece for an anti-fog swimming goggles as claimed in Claim 4, wherein said outer lens is provided with hard-coating treatment.

8. An eyepiece for an anti-fog swimming goggles as claimed in Claim 4, wherein said outer lens is provided with metalization treatment.

9. An eyepiece for an anti-fog swimming goggles as claimed in Claim 8, wherein said inner lens is provided with polarizing treatment.

10. An eyepiece for an anti-fog swimming goggles as claimed in Claim 8, wherein said inner lens is provided with photochromic treatment.

11. An eyepiece for an anti-fog swimming goggles as claimed in Claim 9, wherein said outer lens is provided with gradating treatment.

12. An eyepiece for an anti-fog swimming goggles as substantially described hereinbefore with reference to the accompanying drawing.