Today, I will introduce the cold working process of optical spherical lens. The old rules are illustrated and easy to understand.
The processing of optical parts is divided into hot processing, cold processing and special processing. At present, Manufacturer of spherical lens hot processing is mostly used in the blank preparation of optical parts;
Cold working refers to sawing, rough grinding, fine grinding, polishing and centering edge grinding with loose abrasive or fixed abrasive.
Special machining only changes the performance of the polished surface without changing the shape and size of optical parts. It includes coating, scale, photography and gluing.
The main tasks of each cold working process are:
Milling process: remove the uneven bubbles and impurities on the lens surface to play a forming role;
Fine grinding process: it is to process the parts to the specified size and requirements, eliminate the damaged layer of the milled lens, fix the R value and prepare for polishing;
Polishing process: it is to make the surface of parts bright and meet the required optical accuracy;
Centering process: process the outer circle of the lens relative to the optical axis and grind the outer diameter of the lens to the specified diameter;
Coating process: coating antireflection, reflection and other films on the surface of the lens;
Gluing process: gluing different optical parts together to make their optical axes coincide or turn in a certain direction;
Blackening process: apply a layer of black ink on the rough surface of the lens to achieve the purpose of extinction;
How to maintain the accuracy of surface curvature radius of rough grinding dish?
Rough grinding is carried out by contacting the grinding dish with the lens surface. Although the radius of curvature of the surface of the grinding dish is well modified at the beginning of use, with the grinding of the lens, the grinding dish is constantly worn, Manufacturer of spherical lensand the processing accuracy of the lens may not be guaranteed gradually.
To keep the curvature radius of the rough grinding dish unchanged or less changed, the following measures shall be taken:
1. Reasonably select tools and Fixtures
The size of the upper fixture is always smaller than that of the lower fixture, because the upper fixture has to swing.
If the size of the upper fixture is the same as that of the lower fixture, the edge grinding opportunities of the upper fixture are too few, and the upper fixture has the trend of edge warping.
If the size of the upper fixture is much smaller than that of the lower fixture and exceeds the specified data, Manufacturer of spherical lens the edge of the upper fixture will not be exposed during the swing process, the edge of the upper fixture will be worn too much, and the upper fixture has the trend of edge collapse.
If the size of the upper fixture is larger than that of the lower fixture, there will be too few opportunities for the edge of the lower fixture to be exposed when swinging. The edge of the lower fixture is worn too much, and the lower fixture has the trend of edge collapse.
Factors affecting polishing
Polishing results are affected by many factors:
Roughness of workpiece
Air temperature and relative humidity
Air dust content
Glass type
Part size
1. Size comparison of parts and Fixtures
2. Properties of polishing agent
3. Working shaft speed
4. Swing frequency, Manufacturer of spherical lens swing amplitude and swing center position
5. Temperature and pressure of polished surface
6. Input quantity and temperature of polishing agent
From optical cold working technology, thank you!
