Full-band high-precise machining method for aspheric surface optical element

Abstract

The invention discloses a full-band high-precise aspheric surface machining method. The method mainly comprises the following steps: 1) detecting the surface shape of a to-be-machined aspheric surface which is formed by milling and grinding by using an interferometer; 2) according to the error data of the surface shape to be machined, selecting a suitable flexible polishing small tool, and determining machining parameters of a numerical control machine tool by combining a removal function of the small tool; 3) placing an aspheric surface element to be machined on a machining platform of the machine tool, inputting machining parameters, and executing a polishing process by adopting a variable step pitch spiral machining path; 4) after one-period polishing is completed, detecting the surface shape of the aspheric surface element, and repeating the steps 2, 3 and 4 until the precision of the low-frequency surface shape of the aspheric surface reaches a standard according to the feedback situation of the error data of the surface shape; 5) performing PSD (Power Spectral Density) analysis on the surface shape data of the low-frequency surface shape which reaches the standard, selecting a flexible polishing small tool with a large diameter according to medium-high frequency error frequency distribution characteristics determined by a PSD curve, performing fairing process machining on the aspheric surface optical element, and repeating several times until the medium-high frequency error is controlled effectively. According to the full-band high-precise machining method for the aspheric surface optical element, the full-band high-precise machining of the aspheric surface optical element is completed by only using a CCOS (Computer Controlled Optical Surfacing) numerical control small grinding head machine tool.

Description

technical field [0001] The invention belongs to the field of numerical control processing of aspheric optical elements, and in particular relates to a method for controlling full frequency band errors of aspheric optical elements. Background technique [0002] With the development of modern optical element processing technology, the traditional manual processing of aspheric surface has been gradually replaced by the modern advanced manufacturing technology marked by "deterministic processing" - Computer Controlled Optical Surface Shaping (CCOS) technology. CCOS technology is a technology that uses computer-controlled small tools to achieve a certain amount of processing in a certain area. The theoretical basis for material removal is the Preston equation, which is a processing method that relies on positive pressure to achieve effective material removal. A typical gadget construction is a metal chassis covered with a layer of asphalt, often referred to as a rigid disc due to...

AI Technical Summary

Problems solved by technology

Although this method effectively suppresses the medium and high-frequency errors generated in the processing process and realizes the processing of high-precision aspheric elements, the processing process of this method is too cumbersome, requiring the use of three precision CNC machine tools, and the processing cost is extremely high. high

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