Scale for encoder

Scales for encoders that support position detecting sensor technology

MELTEC’s scales are essential for motion controlling technology and are used in many applications such as industrial robotics, positioning servos, factory automation, and the auto industry.

 

Product features

  • Materials: Metal, PET film, plastic, and others
  • Supported encoder types: Incremental and Absolute
  • Shape: Disk and Linear
  • Style: Transparent and Reflective
  • Combined processing: Assembly of reinforcement plate, double-sided tape, hub, etc.

Introduction to scales for encoders

Click on each link below for more details.

  1. PET film type (Transparent/Reflective styles) : Die cutting of film sheet
  2. Metal type(Transparent style) : Etching of SUS or other metals.
  3. Hybrid type(Transparent/Reflective style) : Precise etching of nickel clad material.
  4. Mirror black type(Reflective style): Etching of metal and low reflection black surfacing treatment.
  5. Plycartonate type: Stamping of polycarbonate material.
  6. Long linear scale(Transparent/Reflective styles): Die cutting of film sheet or etching of metal.

1. PET film type (Transparent/Reflective styles)

A fine pattern on a PET film sheet is created and then stamped out. Mass production at low cost is possible.

Technical features (Unit: mm)

  • High-precision product with a minimum slit width of 0.01 (pitch 0.02) is possible.
  • Achievable pitch tolerance within ±0.002, slit area tolerance is within ±0.005.
  • Disc (transparent style): Achievable center run-out within 0.02, inner diameter accuracy within ±0.02, and roundness within 0.015.
  • Disc (reflective style): Achievable center run-out within 0.05, inner diameter accuracy within ±0.05, and roundness within 0.02
  • Disk: Concyclic bar code difference error is within 0.005.
  • Rate of change of temperature 1×10-3%/℃
  • Rate of change to relative humidity 1% is 1×10-3/%
  • Aluminum metalized film type (reflective style): Reflectance over 60%.

2. Metal type (Transparent style)

Metal (SUS) is processed by photo etching to make the encoder scales. They are not suitable for high resolution but are made at low cost.

Technical features (Units: mm)

  • SUS304 planarity sheet for photo etching is used.
  • Minimum slit width is 0.08 (material t=0.05). A general rule of thumb for the minimum slit width is plate thickness × 150%.
  • Pitch tolerance within ±0.003, the difference between the biggest and smallest slit is within 0.04 in the same lot (when t = 0.1 mm or less).
  • Disc: Achievable center run-out within 0.01, and roundness within 0.01.
  • Disc: Tolerance range for internal diameter accuracy is within 0.04 when t=0.1mm or less (0.01 possible for reamer finish) (for t=0.1 or more, 30% of thickness)

3. Hybrid type – high precision metal (Transparent/Reflective styles)

Etching is performed on a Nickel clad material (Ni-Cu-Ni patented material) for industrial encoders. Precise dimensions and accuracy are realized, unlike with conventional etching processing.

Transparent type etching Dimension accuracy figure

Reflective type etching Dimension accuracy figure

The standard for the minimum slit size D is 75% of the plate thickness.
In the case of t=0.15 and 0.2, plate thickness × 120%.

Technical features (Units: mm)

  • Precision is enhanced on the nickel layer, so high-precision and high-definition etching is possible.
  • Disc: Concyclic slit error is within 0.008.
  • Disc: Pitch tolerance within 0.003, and roundness within ±0.01.
  • Reflective style: High contrast between reflective and non-reflective areas.
  • Reflective style: Compared to the film type product, it is less influenced by humidity.
  • Reflective style: Reflective area at least 65% and non-reflective area less than 10%.
  • Reflective style: Achievable minimum slit width of 0.04.
  • 1m long linear scale is available

4. Mirror black type (Reflective style)

Originally developed and patented, “Mirror Black” is a reflective encoder scale made of SUS material with high-precision etching and low-reflection black treatment.
It provides high resolution and excellent brightness/darkness ratio (signal-to-noise ratio) at a low cost with specifications comparable to those of glass scales.

Technical features (Units: mm)

  • Offers the same spec as glass scales but at a lower cost.
  • Slit tolerance ±0.003.
  • LD ratio at least 65%.
  • High SN ratio: High reflectivity SUS mirror finish and low reflectivity by our unique matte black treatment.
  • Flat structure: The unevenness of the slit pattern is minimized to obtain a noiseless signal.
  • Long type is also available, please contact us for 600~1000mm.
  • The slit width of 0.02 (20 μm) is a reference value. For a slit width of less than 0.04, please contact us.

5. Polycarbonate type (Transparent/Reflective styles)

Thin film etching to polycarbonate base material. The same precision as the glass scale but at a lower cost.

Technical features (Units: mm)

  • Offers the same spec as glass scales but at a lower cost.
  • Excellent impact resistance and hard to crack.
  • High-definition and high-precision
  • High heat resistance (120℃)
  • Both transparent and reflective types are available.
  • Reflective style: At least 70% contrast ratio.
  • Non-transparent slits made of aluminum

6. Long linear scales (Transparent/Reflective styles)

We manufacture PET film and long metal products.

 

Scales for encoders: Table of precision by type

Additonal points

Assembly with hub

Encoder disk unit

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