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SCANNING HEAD
Scanning Head or
Angle Encoder functions
according to the reflected-light
principle. As the scale rotates the
periodic light fluctuation in the
scanning head is transformed into
electrical signals by photovoltaic
cells. The two sinusoidal signals
produced in this way from the
incremental track are shifted with
respect to each other by one fourth of a
signal period. The reference signal is a
signal peak that crosses zero at half
amplitude, at which level it has a width
of approx one signal period of the
incremental signal.
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