■Rotary Encoder Slit Disks
High-precision Circle Division Writing Technology
For rotary encoders, the precision of the Slit Disk that turns the revolutions into signals or code is quintessential.
In order to create more precise patterns, we have incorporated Laser Direct Write Pattern Generators, and carry out production in-house from the master disk.
Unwavering Dependability Founded in Each Step of the Process
Our manufacturing process begins with the grinding of the glass surface. The polished glass then goes through an ultrasonic cleaning machine with 14 tanks to achieve an exceptionally clean surface. A sputtering device is then used to uniformly coat the cleaned surface with a film of chrome (Cr), without even a pinhole-sized discrepancy, creating a glass blank.
Ultrasonic Cleaning Machine
Sputtering Device
Next, in a clean room, photo-fabrication techniques are used to create a precise pattern on the glass blank.
Spin Coater
Exposure Apparatus
Stepper
Stepper
Finally, we use our expert techniques and original methods to machine the patterned glass blank to the form and dimensions required to attain the final Slit Disk.
Core
Dicing Machine
Automatic Chamfering Machine
In this way, we carry out all the steps ourselves, from grinding the glass to machining the glass, as well as creating the master.
Rotary Encoder Slit Disk Principal Specifications
■We can manufacture absolute, incremental, and reflective types. We can also manufacture curved patterns.
■Please ask us for details about the number of partitions and glass materials.
■Standard Glass Material………………Blue sheet, White sheet, BK7, Quartz
■Maximum Diameter…………………………………………………◯150
■Minimum Diameter……………………………………………………◯3
■Standard Glass Thickness (for reference)
※The above are standard values, but we can accommodate other specifications. Please ask us.

■3D Resist Pattern (Gray scale mask)
Summary
Resist is applied to the surface of the glass, and a 3D form is created directly on the resist using a laser (gradation/128/256). Based on this form, a wide range of micro-lenses, etc., can be utilized.
In our company, we only perform the manufacture of resist patterns (3D forms), but it is also possible for us to accommodate further steps such as Nickel plating and imprinting. Please let us know if you wish to pursue these options.
Various reference patterns（3D）
Convex Patterns
Concave patterns
Cones