Wear Resistant Glass Optical Encoder Disc with Excellent Light Transmittance and Resolution 300CPR–5000CPR for Glass Code Disc

A glass code disc is the core component for signal transmission in photoelectric encoders. It is typically made of transparent glass material, with a series of engraved lines or optical patterns formed on its surface through precision processing. As an essential element in modern precision measurement and control systems, it is widely used in equipment requiring accurate position feedback — such as CNC machine tools, robots, servo systems, and automation equipment.

• Transparent glass disc: Usually made of high-quality optical glass with excellent light transmittance, capable of withstanding high-precision laser engraving processes.
• Engraved lines (optical patterns): Fine stripes or optical patterns are engraved on the surface, representing different coding information.

Glass code discs are used in conjunction with photoelectric sensors. The encoder irradiates a light source (usually LED or laser) onto the code disc, and the light is "refracted" and "blocked" by the engraved lines or optical patterns on the glass code disc.

The sensor captures these changes and converts them into electrical pulse signals. These signals can be used to calculate the rotation angle, position, or speed, ultimately providing accurate data feedback for the control system.

1. High Precision and High Resolution: Glass material allows for the production of extremely fine and uniform engraved lines through photolithography processes, enabling the code disc to achieve very high resolution (such as tens of thousands of lines or even higher). This is the core reason it is more precise than metal or plastic code discs.
2. Excellent Light Transmittance: Glass itself has good light transmittance. When used with photoelectric sensors, it provides higher signal contrast and more stable output, which is particularly critical for encoder signal quality.
3. Good Thermal Stability: Glass has a low thermal expansion coefficient, resulting in minimal dimensional changes with temperature fluctuations. It therefore performs more stably in high-precision equipment such as CNC machine tools and semiconductor equipment.
4. Wear Resistance and Long Service Life: The engraved lines are usually formed by photolithography or chromium plating processes, which are not easy to wear. Compared with some printed code discs, it maintains better accuracy after long-term use.
5. Strong Anti-interference Ability: Due to clear signals and high contrast, it is less prone to error codes or jitter in environments with electrical noise or complex conditions.
6. Support for Multiple Coding Methods: It can be manufactured as incremental code discs (common for speed measurement and positioning) and absolute code discs (with a unique code for each position, used for high-reliability positioning).

The structure of a glass code disc typically consists of two parts: the transparent glass substrate and the precision-engraved optical pattern layer.