
Encoder discs are one of our specialties at Photo Reticle
Optical encoder discs are one of our core specialties. With over 20 years of focused manufacturing, we deliver high-precision encoder discs from 5 mm to 600 mm in diameter — in glass, quartz, film, and aluminum. From standard OEM volumes to one-off mission-critical designs, we provide custom tooling, composite assemblies for easy installation, and full support for unusual or highly specialized projects. Bring us your toughest requirements — we turn precision ideas into reliable reality.
Optical Encoder Discs
GLASS – Highest performance, best resolution, critical applications
Maximum OD:
Thickness:
Minimum teature size:
Operating Mode:
Material:
Fatem metallzacion;
300mm
03mm-0.5mm
3μm
Transmissive / Reflective
Sodalime, Borosilicate, Quartz
High/low reflective coating,chrome, gold, and aluminum
PET (MYLAR) – Low-cost alternative, easy installation
Maximum OD:
Thickness:
Minimum reature size:
Operating Mode:
Material:
600mm
0.18mm (Transmissive) / 0.3mm (Reflective)
10μm
Transmissive / Reflective
Photographic film, composite PET, acrylic,and PSA backing
ALUMINUM – Ideal for extreme environmental conditionst
Maximum OD:
Thickness:
Minimum reature size:
Operating Mode:
Material:
250mm
0.5mm
10μm
Reflective
1100 Aluminum alloy

Glass Encoder Discs
Chrome-on-Glass Encoder Discs offer the highest level of accuracy thanks to the exceptional flatness of the glass substrate and the ultra-precise photolithographically etched chrome pattern.
We directly use your CAD data to fabricate the discs exactly to your specifications. The process starts with creating a high-resolution glass master, followed by precise replication to produce the final parts.
Glass encoder discs are typically shipped within two weeks after final data approval.
Available specifications:
- Outer diameter (OD): 5 mm to 400 mm
- Thickness: 0.010″ (≈0.25 mm) to 0.120″ (≈3.0 mm)
In short:op-tier precision, fast turnaround, and flexible sizing. If you have CAD files or specific requirements ready, we can quickly turn them into high-performance chrome-on-glass encoder discs!

Transmissive Mode Glass Discs
Transmissive Glass Encoder Discs are specifically designed for OEM integration and high-performance applications.
Standard configuration: Soda-lime glass substrate + low-reflective chrome coating (optical density OD 2.8), upgradable to OD 5.0+ for improved contrast and signal quality.
Premium options:
- Extreme accuracy / sine-wave signal applications → ultra-flat quartz substrate
- High-temperature environments → borosilicate glass substrate (excellent thermal shock resistance and heat stability)
- Primary use: OEM & high-performance transmissive encoders
- Standard: Soda-lime glass + low-reflective chrome (OD 2.8, upgradable to 5.0+)
- Enhanced: Quartz (ultra-precision/stability) or borosilicate (high-temperature resistance)
Quick summary:
- Primary use: OEM & high-performance transmissive encoders
- Standard: Soda-lime glass + low-reflective chrome (OD 2.8, upgradable to 5.0+)
- Enhanced: Quartz (ultra-precision/stability) or borosilicate (high-temperature resistance)
Flexible combinations of materials and coatings meet demands for precision, signal quality, environmental durability, and thermal performance.

High-Temperature Reflective Aluminum Encoder Discs
For high-temperature applications, we offer reflective aluminum discs that can withstand extreme environmental conditions, with diameters up to 250 mm.
Key points:
- Withstands temperatures up to 700°F (≈371°C)
- Excellent durability against shock, vibration, moisture, solvents, and corrosion
- High reflectivity for reliable optical signal in reflective-mode encodersExcellent durability against shock, vibration, moisture, solvents, and corrosion
- Diameters available up to 250 mm
In short: Aluminum reflective discs are the rugged, high-temperature solution when glass or Mylar cannot handle the heat or harsh conditions — ideal for industrial, automotive, aerospace, and heavy-duty environments.

Reflective Mode Glass Discs
High Reflective Chrome (HRC) Coating — Optional, with >60% reflectivity (excellent in 400–1000 nm), ideal for reflective-mode encoders requiring strong, consistent signals.
Key Configurations:
- High reflective + transparent patterns (for hybrid optical designs)
- High reflective front + ultra-low reflective chrome back (<5% in 550–720 nm), eliminating ghosting, stray light, and parasitic signals for cleaner, more reliable performance
Premium Option: Gold coating for superior corrosion resistance and extreme durability
Unique Capability: Single glass disc with combined transmissive + reflective patterns, enabling dual-mode reading and simplifying integration
Summary: HRC ensures strong signals, high contrast, low noise, and multi-mode flexibility — perfect for robotics, precision servos, medical devices, aerospace, and other high-reliability applications.

Mylar Encoder Discs
PET (Mylar) Encoder Discs — Ideal for Low-Cost Applications
We use automated precision processes to produce lightweight PET encoder discs, offering major cost savings for prototypes and high-volume runs.
Key Features:
- Optical-grade PET film, 0.18 mm thick
- High-resolution printed pattern for clear readability
- ID/OD cutting tolerance: ±0.025 mm (to pattern); eccentricity <0.05 mm TIR
- Simple static press-fit mounting
Optional Features:
- Laser-cut registration/alignment holes
- Peel-off protective liner
- Bonded to acrylic for added thickness & rigidity
Main Advantages:
- Cost only 1/5–1/3 of glass discs
- Extremely lightweight → low inertia, great for high-speed use
- Sufficient accuracy for medium-to-low resolution needs
- Fast production and delivery for volume orders
We’ve been partnering with you for 10 years now, and have used quite a number of your encoder discs over that time. I have to say, the latest batches are the best-looking and most precise ones I’ve seen in all these years on our test equipment. Our theodolite and level instrument motors are now fully back in spec, with rock-solid performance. It’s great to see the flutter tests and time base error tests all returning to normal — the results are excellent. Thank you and your team for the consistent support and quality over the past decade!
Yu Da | Engineer Tianjin SET Surveying Instruments Co., Ltd. | Precision Geodetic Measurement Solutions
