Direct binary interpretation
Binary weights simplify the numeric interpretation when the reader is designed for this code. The installed transition behaviour must be evaluated with that reader.
See why multi-bit transitions need coordinated samplingBinary Code Encoder Discs
A code map matched to your decoder.
Patterned glass encoder componentCustom formats
Product selection
What it is and what it does
A natural-binary encoder disc assigns binary weights to optical tracks. The matching reader combines their states into a single-turn position word.
When to choose it
Choose it for an existing binary-weighted reading architecture with a defined method for sampling and resolving code transitions.
How it differs from related products
A transition such as 0111 to 1000 changes four bits. Gray encoding changes only one bit between adjacent words; the two disc types require different code interpretation.
What can be customised
Bit count, MSB/LSB track positions, transition angles, optical polarity, reading direction and code zero can be aligned with the electronics.
What you receive
A patterned glass disc with the selected track layout, mounting geometry and component inspection records. The light source, readhead, decoder and shaft assembly are defined by the instrument design.
Specifications and inspection
Product configuration
| Substrate | B270 / K9 / soda-lime glass; fused silica by request |
|---|---|
| Pattern medium | Chromium-on-glass or a specified clear/opaque pattern |
| Photolithographic line-width tolerance | ±0.2 µm |
| Mechanical cutting accuracy | ±0.02 mm |
| Thickness | ≥0.4 mm |
| Total thickness variation (TTV) | ≤2 µm |
| Surface figure | λ/4 |
| Optical mode | Transmissive or reflective, matched to the readhead wavelength |
| Maximum disc diameter | 1500 mm |
| Pattern-to-bore concentricity | ≤0.02 mm |
Pattern architecture and system fit
A disc or scale is the passive optical reference inside a larger encoder system. The artwork, readhead and mounting datum must be designed together so that the manufactured pattern is read in the intended direction and at the intended contrast.
| Property | Specification |
|---|---|
| Pattern architecture | Multi-track natural-binary sequence for absolute angular position |
| Code definition | Bit count, most-significant-bit and least-significant-bit track locations |
| Critical geometry | Transition angle, track registration and mechanical zero datum |
| Readhead interface | Wavelength, contrast and transition handling defined with the electronics |
System resolution and system accuracy are separate from the manufactured CD and outline values. Interpolation, bearing runout, eccentricity, alignment and electronics contribute to the final error budget.
Glass code discs carrying natural-binary tracks for absolute angular-position measurement in compatible optical encoders. Each concentric track represents a weighted bit, so the approved bit order and reading direction must be unambiguous on the drawing.
Built for your process.
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A code map for a binary-weighted reader
Existing optical layouts
Keep the established track order and datum when replacing a drawing-defined part. A Gray-code disc with the same dimensions is not a code-compatible replacement.
Match the complete code map to the readerInspection and acceptance
Compare the manufactured code map with the approved sequence and inspect transition positions, radial registration, concentricity and any ambiguous or damaged code cells.
| Property | Specification |
|---|---|
| Pattern dimensions | Measured CD at agreed locations; report nominal and measured values |
| Outline geometry | Outer diameter, bore or scale length checked to the mechanical drawing |
| Registration | Pattern origin, track-to-bore or pattern-to-datum position |
| Optical defects | Clear/opaque defects, broken lines, pinholes and contamination |
| Traceability | Drawing revision, lot identification, inspection method and report |
What to include in the drawing
| Property | Specification |
|---|---|
| Geometry | Disc outer diameter and bore, or scale length, width and thickness |
| Pattern data | Approved artwork or code map, line count/pitch, polarity and revision |
| Optical interface | Transmissive or reflective mode, wavelength, contrast and readhead gap |
| Datum scheme | Mechanical datum, pattern origin, index/zero position and orientation |
| Acceptance record | CD measurement, cutting dimensions, registration, defects and report format |
Substrate & optical configuration
Specify substrate material and geometry together with the operating wavelength. For transmissive reading, define clear-area transmission and opaque-track density. Reflective reading also needs the high/low reflectance pair and illumination geometry. Optical contrast must match the readhead, not only the appearance of the part.
Compare transmissive and reflective readoutQuality & Inspection PhotolithographyWhere this product is used
Absolute angular code for a readhead designed for this encoding.
Natural-binary patterns for readheads and decoders designed for that code.
Natural-binary track layouts for compatible decoders.
Selection notes
Binary-code absolute encoder discs represent angular position with natural-binary optical tracks.
Define MSB and LSB locations, transition boundaries, mechanical zero and sampling convention as a consistent system.
Information for your inquiry
Bit count, MSB/LSB order, track boundaries, angular direction, zero and optical window.
How does natural binary differ from Gray code?
Natural binary can change several bits at a boundary; adjacent Gray words change one bit. The readhead and sampling scheme must support the selected code.