Canon X-1M Brochure
LASER
ROTARY ENCODER
Canon’s Technology Has Changed the World of Rotary Encoders:
81 000 Pulses with 36mm Diameter
81 000 Pulses with 36mm Diameter
81,000 Pulses with 36mm Diameter
THEORY
As illustrated in the diagram, laser beams are applied to two
points equidistant from the grating disc's center of revolution
points equidistant from the grating disc's center of revolution
points equidistant from the grating disc s center of revolution.
One diffraction beam is positive first order (+1) and the other is
negative first order (-1).
For each 1 pitch that the grating disc revolves, the ±1 diffraction
light will change each phase by ±2π. Reflecting the ±1 diffraction
light into respective mirrors and then reapplying it to the
grating disc changes the phase by ±4π.
In this way, each time the grating disc revolves 1 pitch, the
brightness interference signals for 4 cycles can be obtained,
making highly accurate angle sensing possible.
One diffraction beam is positive first order (+1) and the other is
negative first order (-1).
For each 1 pitch that the grating disc revolves, the ±1 diffraction
light will change each phase by ±2π. Reflecting the ±1 diffraction
light into respective mirrors and then reapplying it to the
grating disc changes the phase by ±4π.
In this way, each time the grating disc revolves 1 pitch, the
brightness interference signals for 4 cycles can be obtained,
making highly accurate angle sensing possible.