Method and device for producing thick lenses of plastic material
OwnerAndrea Falliniinventor
Life of this patent
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Abstract
To produce thick lenses of plastic material, a mold is first prepared having an inner cavity corresponding in shape to the lens for molding and having a work surface corresponding to an optical surface of the lens for molding; and liquid plastic material is then injected into the cavity of the mold. According to the invention, the injection is effected at a geometric center of the work surface and in a direction substantially perpendicular to the work surface, i.e. substantially along an optical axis of the lens for molding.
Claims9
A method of producing thick lenses of plastic material, in particular lenses having a diameter to thickness ratio of less than about 10, and comprising the steps of:
- preparing a mold (2) having an inner cavity (3) corresponding in shape to the lens for molding and having a first work surface (10) corresponding to a first optical surface of said lens;
- and
- effecting an injection of liquid plastic material into said cavity (3) of the mold (2);
- the method being characterized in that said injection of liquid plastic material is effected at a geometric center of said first work surface (10) and in a direction substantially perpendicular to said first work surface (10).
A device (1) for producing thick lenses of plastic material, in particular lenses having a diameter to thickness ratio of less than about 10, and comprising a mold (2) having an inner cavity (3) corresponding in shape to the lens for molding, and an injection channel (4) for feeding liquid plastic material into said cavity (3);
- an end wall (8) of said cavity (3) having a first work surface (10) corresponding to a first optical surface of said lens;
- and the device being characterized in that said injection channel (4) is formed through said end wall (8) of said cavity (3), is substantially perpendicular to said first work surface (10), and communicates with said cavity (3) through an injection hole (14) located at the geometric center of said work surface (14).
Dependencies are inferred from the claim text.