Compare two existing disc design examples before defining a custom rotary pattern.
Optical Encoder Discs
Photolithography-patterned glass for rotary position sensing. Compare two pattern layouts or discuss a custom drawing.
Photolithography product familyRotary position sensingTransmissive or reflective layouts by specification
Precision in
every track.
A fine-pattern glass encoder disc for optical position sensing. Explore the original pattern geometry in the interactive view.
- Outer diameter
- 79 mm
- Bore diameter
- 51 mm
- Material
- Ultra-clear glass
TLoptikGlass encoder disc / 79 mm
Choose by function
What it is and what it does
The patterned glass is the physical position reference in an optical encoder. A compatible readhead illuminates the pattern and converts changes in light into signals for a controller.
When to choose it
Use a disc for rotary motion and a scale for linear travel. Then choose whether the instrument can establish a reference at startup or must identify its position directly from the code.
How it differs from related products
Transmission versus reflection defines the optical path; incremental versus absolute defines the position code. These are separate choices: first check readhead access, then decide how the machine should recover its position.
What can be customised
Track geometry, periods or code layout, reference marks, active reading area, mounting datums and substrate outline can be adapted together. Optical contrast is matched to the illumination and readhead arrangement.
What you receive
A patterned encoder disc or linear scale with the agreed track layout, mounting dimensions and component inspection records.
Annular-pattern
glass encoder disc
The annular code track surrounds a clear central opening. Radial graduations provide the angular reference, while index marks establish a repeatable zero position.
Explore this designDefine your encoder disc
Share the track layout, geometry, optical mode and acceptance criteria for the component you need.
Read the specification guide| Outer diameter | 79 mm |
|---|---|
| Bore diameter | 51 mm |
| Material | Ultra-clear glass |
| Pattern | As supplied in the original artwork |
| Photolithographic line-width tolerance | ±0.2 µm |
| Mechanical cutting accuracy | ±0.02 mm |
| Pattern-to-bore concentricity | ≤0.02 mm |
| Thickness & tolerances | To be defined in the drawing |
| Quantity & delivery | Confirmed per inquiry |
What belongs in the drawing
- Outer diameter, bore, thickness and datum features
- Track layout, line count, reference marks and orientation
- Substrate, optical mode and contrast requirements
- Inspection criteria, quantity and target delivery
Where this product is used
Existing glass disc examples and a starting point for custom track layouts.
Fine-pattern disc example with an interactive view of the code track.
Technical reading
Selection notes
Optical encoder discs use periodic or coded tracks on glass as the optical reference for rotary position and speed sensing.
Choose incremental or absolute coding, then match track radius, bore, zero position, read direction and optical mode to the readhead.
Information for your inquiry
Outer diameter, bore, thickness, tracks or code map, wavelength, film side and mounting datums.
Is the disc a complete encoder?
The disc is the patterned optical component. A complete encoder also needs illumination, a readhead, mechanical installation and processing electronics.