Unlock instant, AI-driven research and patent intelligence for your innovation.

Methods Relating to Molding Optical Lenses

a technology of optical lenses and molding, applied in the direction of instruments, fluid-tightness measurement, measurement of fluid loss/gain rate, etc., can solve the problems of high rejection rate, high rejection rate, and often obtained optical lenses with localized optical defects of greater or lesser severity, so as to minimize (or even eliminate) the size of the opening, the effect of reducing the cost of inspection

Inactive Publication Date: 2008-05-15
KEITA GABRIEL +1
View PDF23 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

This approach allows for fast and cost-efficient molding of optical lenses with reduced microbubble formation and material leakage, enabling the production of high-quality lenses without the need for expensive valves, while evaluating sealing materials for their self-sealing properties to ensure effective sealing.

Problems solved by technology

Experience has shown that in the case of a relatively long waiting time (for example, on the order of two hours) between filling the mold and starting polymerization, unless special measures are implemented, the optical lenses obtained frequently have localized optical defects of greater or lesser severity, which leads to relatively high reject rates.
However, in the case of molding material that reacts at room temperature in less than ten minutes, such as the formulations disclosed in U.S. Pat. No. 5,973,098, the pipe will quickly clog.
While use of a check valve, which may be a duck bill valve as disclosed in the referenced application, addresses the aforementioned clogging problem, use of such valves may be expensive.
Next, the molding material is cured in a heating furnace for about 10 to 15 hours at about 100° C. The filling method disclosed in the Japanese application is not confronted with, and therefore does not address, the problem of molding material leaking out of the molding cavity A around the injection needle or exhaust tube.
In addition, problems with encountering localized optical defects due, for example, to microbubbles that form in the molding material as it fills up cavity A may be present with the method disclosed in the Japanese application unless special measures are implemented.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Methods Relating to Molding Optical Lenses
  • Methods Relating to Molding Optical Lenses
  • Methods Relating to Molding Optical Lenses

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0039]In order to enable the inventors to screen materials for use as sealing materials, the test set-up shown in FIGS. 5A and 5B was created. As shown in FIG. 5A, testing system 100 includes glass site tube 84, which is 6 inches long, has an outer diameter of 0.625 inches and an inner diameter of 0.500 inches. The glass tube permitted the testers to view the water level within the tube (i.e., within the cavity) such that those materials that were inefficient at self-sealing would be apparent (e.g., because the water would leak out and the water level would drop). In addition, the glass tube permitted the testers to view the formation of any bubbles in cases in which the material being tested was not sealing completely against the vacuum applied. The glass tube had an opening at its bottom end, which was covered with a piece of the material to be tested 99.

[0040]The piece of material to be tested was pierced by needle 96, which was a 16-gauge by 1-inch Becton-Dickinson insertion nee...

example 2

[0046]A polymerizable composition was prepared from two pre-polymers. Different materials were then tested for use as sealing materials in the creation of lenses from the polymerizable composition.

[0047]The two pre-polymers were prepared according to following procedure, which is described fully in U.S. patent application Ser. No. 10 / 012,727, filed Nov. 5, 2001 by Gabriel Keita, Joey 0. Obordo, Pamela Anne McClimans, and Yusef Turshani, and which is incorporated by reference:

[0048]Part A—NCO

[0049]A reactor equipped with a condenser, a thermal probe, and an agitator was charged with a determined amount of xylylene diisocyanate (XDI). The monomer XDI was heated to 115° C. Next, 3-(2-sulfanylethylthio)-2-(2-sulfanlethylthio)propane 1-thiol was introduced and mixed with polyisocyanate in amounts such that the molar ratio of isocyanate functions to the thiol function

(NCOSH)

was 8:1.

[0050]The reaction was complete after 3 to 4.5 hours. The final Part A prepolymer with isocyanate end groups...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
angleaaaaaaaaaa
angleaaaaaaaaaa
degree of rotationaaaaaaaaaa
Login to View More

Abstract

A method that includes providing a cavity defined by at least a portion of a mold and a closure member attached to the portion of the mold, the portion of the mold being oriented vertically and having a top and a bottom, and a sealing material being positioned near the bottom and attached to the closure member; puncturing the sealing material and the closure member with an instrument near the bottom, the puncturing creating an opening in the sealing material; and introducing a polymerizable composition into the cavity through the instrument. A method useful in testing sealing materials. Other methods are also disclosed.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The invention relates to testing materials for possible use during the molding of optical lenses. The invention also relates to molding optical lenses, particularly ophthalmic lenses, from polymerizable compositions.[0003]2. Description of Related Art[0004]The traditional mold comprises a molding cavity defined by two mold pieces, each typically made of mineral glasses, and an annular closure member, such as a gasket or an adhesive tape, disposed around the periphery of the two mold pieces and attached to them. The conventional way to fill such a two-piece mold is by causing the molding material to flow into the molding cavity through a casting opening provided for this purpose in the closure member. In at least a partly automated process, the molding cavity to be filled is vertically aligned with a filling device that is adapted to deliver a particular quantity of molding material through a nozzle.[0005]One way to fill...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(United States)
IPC IPC(8): G01M3/34B29C31/04B29C33/00B29C39/24B29C41/04B29D11/00G01N3/00G01N33/44
CPCB29C31/04B29C33/0038B29C39/006B29C39/24B29C39/26B29C39/42B29L2011/0041B29D11/00B29D11/00413B29D11/00528B29D11/00538B29L2011/0016B29C41/04
Inventor KEITA, GABRIELBORYSLAWSKI, JOSEPH
Owner KEITA GABRIEL