Tool, apparatus, and method for precision polishing of lenses and lens molds

Abstract

A tool for polishing objects having a wide variety of materials and shapes including precision optical surfaces, injection mold inserts, and thin film coating dies. The tool has an elastic solid bladder with a curved surface, upon which is disposed an abrasive band. The curved bladder surface is produced by compressing the bladder between two parallel plates. The apparatus comprises a multi-axis computer controlled machine to which the tool is attached.

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS [0001] This application is a continuation-in-part of copending patent application U.S. Ser. No. 10 / 863,702, filed on Jun. 8, 2004, which is a continuation-in-part of copending patent application U.S. Ser. No. 10 / 439,833, filed on May 16, 2003, the disclosures of which are incorporated herein by reference.FIELD OF THE INVENTION [0002] A polishing tool for correcting surface errors, and for polishing objects comprising a wide variety of materials and shapes including precision optical surfaces and injection mold inserts. BACKGROUND OF THE INVENTION [0003] This invention relates to tools, an apparatus, and a method for correcting figure errors, and for polishing a wide variety of materials and shapes including but not limited to precision optical surfaces, injection mold inserts, thin film coating dies, and the like. The method of the present invention provides for improving and further finishing of any surface, ranging from a relatively r...

AI Technical Summary

Benefits of technology

[0029] The tools, apparatus, and method of the present invention are advantageous because they are simple and lower in cost compared to other approaches, and it can be adapted for the polishing of a variety of materials and shapes, particularly those objects having deeply concave shapes. As a result of the invention, articles of manufacture such as precision optics, injection mold inserts, and thin film coating dies can be polished with high precision at a high throughput and low cost.

Problems solved by technology

This prior art process is sufficient for many conventional low-precision lenses, but when the desired lens has a shape that is not spherical or plano and / or where such conventional methodologies cannot be applied e.g., aspherics, or where the lens has very high accuracy requirements, such prior art process is not sufficient.

The polishing tool wears quickly due to its small diameter, which results in the distinct disadvantages of a) typically very long polishing cycles; and b) because of quicker degradation of the small polishing foil it is much more difficult and costly to develop accurate corrective polishing routines.

Another disadvantage is due to the small spot diameter of the tool.

Material removal rates are typically very slow, since the performance is directly proportional to the size of the surfaces that are in contact during the polishing routine.

Although the MRF process has many attributes, such process also has some distinct disadvantages as follows: 1) Cost-effective polishing of deviations is limited to errors of less than 200 nanometers only.

2) There is a very high capital cost of entry into the MRF technology.

The process entails very complex technology, which also increases the cost of operation.

It is also necessary to continuously change the MRF polishing suspension, which is very expensive because of its proprietary nature.

3) Parts made of magnetic materials are not able to be polished with this process, as the workpiece will become magnetized and not release the magnetic process fluid.

4) Small concave parts cannot be polished due to the configuration and size of the MRF polishing wheel.

Although as stated therein, the apparatus of Mandler can change the pressure during the process, such process does not have the ability to change to softer media, such as felt or other softer synthetic materials as is disclosed and claimed in this application.

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