A bearingless angle encoder.
A new series of bearingless modular angle encoders, the ERP 4080 and the ERP 8080, were recently introduced by HEIDENHAIN. These encoders incorporate a new scanning method that utilizes a very small scanning area illuminated by a spot laser. The fine grating period of the circular scale (approximately 2 [micro]m) diffracts the light, which is then collimated in the scanning reticle and brought into interference. As a result, circular scales with a grating period of 2 [micro]m supply output signals with a signal period of approximately 1 [micro]m. According to the company, these encoders offer high signal quality, in addition to:
* A combination of small signal periods and large mounting tolerances.
* Highly resolved speed control, as well as positioning requirements.
* An outside diameter of 44 mm, an insider diameter of 8 mm and 131,072 signal periods on the ERP 4080.
* An outside diameter of 108 mm, an inside diameter of 50 mm and 360,000 signal periods on the ERP 8080.
* Optimal position stability and reproducibility via the low-noise electronics integrated in the scanning head.
* The ability to compute measurements in the single-digit nanoradian realm.
* Typical applications in clean environments.