The production process of cylindrical lens mainly includes rough grinding, fine grinding, polishing, centering and edging.
Coarse grinding cylindrical lens:
Generally, the rough grinding of cylindrical mirror with small radius is to glue the square blank onto the mould, form the cylinder, and then process the outer circle to obtain the cylindrical surface. Generally, the parts with thickness equal to or greater than the radius of curvature R of the cylindrical surface are roughly ground into the overall aid, and then the surplus parts are ground after finishing the fine grinding and polishing.
Conventional cylindrical grinder can be used for rough grinding of cylindrical mirror cylinder, but centerless grinder should be used if the diameter of cylindrical mirror is small.
Generally, when the number of cylindrical mirrors is small, the four corners of the square blank can also be manually ground on the rough mill, and then the cylinder can be installed on the main shaft of the instrument lathe, and then the flat iron plate inclined to a certain angle with the horizontal plane can be installed on the lathe tool holder to process the outer circle. The rough grinding of cylindrical mirror with medium or more curvature radius can be formed by milling.
Fine grinding cylindrical mirror:
For the fine grinding of cylindrical mirrors with small radius, when the number of products is small, the method of manual plus instrument lathe can still be used. The details of the method is to replace the fine grinding abrasive. When mass production, the method of flat grinding up and down and clamping the separator in the middle is generally used. During the fine grinding process, the cylinder should be turned around regularly to avoid grinding into a cone. Another way to fix the separator is to replace the middle mandrel with an outer retaining ring.
For cylindrical lens with medium radius, after milling and forming, they are often glued to the mould to form a mirror column for fine grinding. Then install the mirror column on the lathe spindle, and then install the mold on the lathe tool holder, and then add loose abrasive for fine grinding. For concave cylindrical mirrors and large-radius cylindrical mirrors that are not suitable for gluing into cylinders, they are often glued into a mirror disk first, and then polished with corresponding cylindrical molds on a cylindrical machine tool.
Cylindrical lens polishing:
The polishing process is similar to fine grinding. Generally, there is a layer of felt with a thickness of 3~5mm on the polishing mold, and the length of the polishing mold is about 1/3 of the length of the cylinder.