Patent Application
20200166674
The present invention relates to an anti-fog lens and, more particularly, to a lens which includes an anti-fog film pre-attached to a polycarbonate film and subsequently placed in a mold to be securely attached on an optical body under a high temperature, so that the lens can achieve a stable and excellent performance on prevention of fog.
For a general lens made of a polycarbonate material, due to the confined space of the associated goggles and the body temperature of a wearer's body, fogging may happen on the lens. To achieve anti-fog effect, it is necessary to take corresponding anti-fog measures for a lens. The most common measure is using an anti-fog film, which can be attached to a rear surface of a lens via an adhesive. However, this attachment is insecure. For polycarbonate lenses, due to their smooth surfaces, they are somewhat difficult to be attached with an anti-fog film, such as a triacetate (TAC) film. Even though a polycarbonate lens is configured with recesses thereon to facilitate attachment with an anti-fog film, a secure bonding effect cannot be ensured. Thus, there is a need for improvement.
One object of the present invention is to provide an anti-fog lens, which has a stable and excellent performance on prevention of fog.
The anti-fog lens comprises an optical body made of polycarbonates and an anti-fog film combination located at a rear surface of the optical body. The anti-fog film combination is constructed of an anti-fog film made of triacetate, and a polycarbonate film, which are joined together by spreading an optical adhesive therebetween. The optical body and the anti-fog film combination are placed in a mold into which a molten polycarbonate material is injected. As such, the optical body and the anti-fog film can be joined together after the molten polycarbonate material is cooled and solidified. Preferably, the anti-fog film has a thickness between 0.3 and 0.6 mm, and the polycarbonate film has a thickness between 0.3 and 0.6 mm.
One advantageous feature of the anti-fog lens is that an anti-fog film associated therewith is pre-attached to a polycarbonate film to form an anti-fog film combination, which is subsequently placed on an optical body located in a mold, which is subsequently filled with a molten polycarbonate material, whereby the high temperature of the molten polycarbonate material enables the optical body and the anti-fog film to be joined securely.
Other objects, advantages, and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
To illustrate the features and effect of the present invention, a preferred embodiment with reference to the accompanying drawings is provided in the following.
Referring to
The anti-fog lens of the present invention can be configured to any shapes and applied to various helmets and goggles. As an application example shown in
As another application example shown in
As a further application example shown in
A method for manufacturing the anti-fog lens of the present invention may include the following steps:
Step 1: joining an anti-fog film 1 and a polycarbonate film 2 together by spreading an optical adhesive therebetween to form an anti-fog film combination 4, which can be further shaped by heat, wherein the anti-fog film 1 is arranged on a rear surface of the polycarbonate film 2;
Step 2: placing the anti-fog film combination 4 in a mold, on a rear surface of an optical body 3 that had been located in the mold; and
Step 3: injecting a molten polycarbonate material into the mold such that the interior of the mold achieves a temperature between 260 and 280 degrees C. upon the molten polycarbonate material being fed into the mold, thus forming a multi-layer anti-fog lens after the molten polycarbonate material being cooled and solidified.
It is noted that the above temperature range, between 260 and 280 degrees C., is the temperature of the polycarbonate material which has been fully melted and fed by a screw to enter the mold. There is no limitation about the pressure of the molten polycarbonate material and the time of the material retained in the mold, if the two pieces can be secured. Also, it is noted that the polycarbonate film 2 is indispensable in making an anti-fog lens. Thus, the polycarbonate film 2 serves as a key element in the present invention. With the polycarbonate film 2 pre-attached with the anti-fog film 1 to form a combination, an anti-fog lens can be successfully produced in the subsequent molding process.
While the invention has been described with reference to the preferred embodiment above, it should be recognized that the preferred embodiment is given for the purpose of illustration only and is not intended to limit the scope of the present invention and that various modifications and changes, which will be apparent to those skilled in the relevant art, may be made without departing from the scope of the invention.
