Technology
Core encoder disc manufacturing processes at Jingzheng Optoelectronics: lapping and polishing, optical coating, photolithographic patterning, precision laser cutting and machine vision inspection.
The encoder disc is the core component of an optical encoder: its graduation quality, pitch uniformity and edge quality directly affect the encoder's resolution and signal stability. Jingzheng Optoelectronics has built an end-to-end precision process chain for encoder disc manufacturing, from substrate preparation to final inspection.
Lapping and Polishing
Substrates are precision-lapped and polished to control flatness and surface quality, providing a sound basis for subsequent coating, photolithographic patterning and inspection.
Optical Coating
Reflective or anti-reflective coating stacks are deposited according to the optical path, suiting both transmissive and reflective encoder designs and improving optical signal efficiency.
Precision Photolithographic Patterning
Photolithography is used to pattern the disc graduations on glass or metal substrates. Compared with mechanical ruling, photolithography produces sharper line edges, more uniform pitch and higher light/dark contrast, making it the key process for high-resolution encoder discs.
- Suitable for incremental and absolute multi-track patterns
- Sharp line edges and high contrast
- Uniform pitch for better signal interpolation
Precision Laser Cutting
Lasers are used to cut the outer diameter of the disc and to machine the bore. Laser machining has a small heat-affected zone and low edge chipping, helping keep substrate edge quality consistent.
- Laser OD cutting: forms the disc outer diameter with a small heat-affected zone, low chipping and consistent edge quality.
- Laser bore machining: machines the central mounting hole of the disc with controlled hole position accuracy.
Automated Machine Vision Inspection
An automated machine vision system inspects disc graduations and surface defects, with key parameters checked disc by disc to ensure the consistency and reliability of shipped products.
- Graduation integrity and pitch inspection
- Detection of surface defects (scratches, stains, chips)
- Automatic measurement of critical dimensions
Technical Articles
- Encoder disc glossary: 30 common terms explained
- Does temperature change affect encoder disc accuracy? How to evaluate substrate thermal expansion
- Where does the interpolation error of sine/cosine encoder discs come from? 4 signal quality metrics to check
- What is the difference between incremental and absolute encoder discs? How to choose
- How do you choose the line count of an encoder disc? Line count, interpolation and encoder resolution
- What should incoming inspection of encoder discs check? Visual defects, dimensions and optical parameters
- Reflective metal or glass encoder disc? Choosing by optical path, accuracy and environment
- Weak signal and large interpolation error with a reflective disc? Check the high/low reflectance contrast first
- How much angular error does 5 μm of disc eccentricity cause? Sources, measurement and control of eccentricity
- Requesting a quote for a custom encoder disc: 20 parameters to send the manufacturer