Papers by Keyword: Aspherical Lens

Abstract: A point autofocus instrument (PAI) is widely used for the roughness and contour measurement of various precision processing surfaces, because it is capable of measuring a large area in high precision. The only disadvantage of PAI is to require a long measurement time. Its conventional index measurement stops the scanning stage in order to obtain each coordinate value of the fixed sampling pitch. Hence, it was necessary to develop a scanning point autofocus instrument (SPAI) which can obtain coordinate values while the scanning stage is moving. As an achievement of the development, the SPAI offers 26 times faster measurement speed than that of the index measurement with equivalent accuracy. The SPAI easily measures 3D surface texture and provides quantitative evaluations of the precision processing surfaces.

Abstract: In order to do the precision grinding of optical aspheric lens, it is essential to achieve high quality surface roughness. Experiments show that the contacting area between the wheel and workpiece in a grinding process is critical to influence the surface roughness for a fine grit size resin bonded wheel. The precision grinding are performed with BK7 optical lens. This paper deals with the grinding of an aspheric surface optical lens by diamond wheel. This study also compares each machining parameter (work spindle speed, wheel spindle speed, feedrate, etc.) in rough grinding, fine grinding and polishing on the aspheric lens. In this study, several experiments were carried out BK7 optical glass lens by using vitrified, metal, resin bond diamond wheel and the polisher of urethane ball was used to remove the tool marks with an ultra-precision in-line grinding system. It was found that machining parameters significantly influence the surface roughness of aspheric optical lens.