Precise measuring and displaying of linear motions in machine tool, metal-prossesing, electro-erosive and wood-prossesing machines, control and measuring devices and microscopes.

The encoders can be fixed on the moving machine parts and the DRO units on comfortable position for the operator. The measuring and the readout are realized directly. In this way the lead screws play can be successfully compensated.

MEASURING PRINCIPLE
Оptoelectronic reading of light beams modulated by precise graduated glass scales.
The encoder consists of a measuring scale and a scanning unit. The measuring scale has a measuring pattern with grating period of 20 or 40 µm and a reference track of reference marks coded at 50 mm intervals. The scale is protected against mechanical and chemical contamination by sealed aluminum housing and flexible lips. The scanning unit includes a reading carriage, a coupling cable and a housing with mounting holes. A scanning plate and PCBs with LEDs and phototransistors are integrated in the carriage. When the scanning unit slides along the measuring scale, the grating of the scale coincides periodically with the pattern of the scanning plate changing the light intensity exposed on the phototransistors. Two phase- shifted by 90° sinusoidal signals and one reference signal are generated as a result of this modulation. The signals are additionally amplified and processed by the electronics in the reading head.

OUTPUT SIGNALS
The linear encoders are offered with square wave or sinusoidal output signals depending on the application and the readout resolution. The 90° phase shift of the output signals enables additional digital multiplying and determination of the motion direction. The reference pulse generated in the moment of crossing of the reference mark of the encoder is used for defining the output coordinates of the measuring system. Noise resistance is additionally increased using both normal and inverted signals.