Laser Rotary Encoder
Product
Laser Rotary Encoder
Product ID: R-1SL
Canon’s Technology Has Changed the World of Rotary Encoders:
81,000 Pulses with36mmDiameter
Canon laser rotary encoders use the light-diffraction interference method, with a semiconductor laser as the lightemitter element. The result is an ultra-compact size encoder that combined was impossible with traditional rotary encoders. This product is a compact, high-precision rotary-angle sensor that is certain to play a major role in the development of high-technology products that will lead the market in the 21st century in a wide variety of fields such as robotics, manufacturing machinery, and measuring equipment.
THEORY
As illustrated in the diagram, laser beams are applied to two 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.
Features:
- Using diffraction and interference with high precision grating disk, Canon laser rotary encoders minimize the product size and offer very high density pulse making features.
- Two laser beams are irradiated simultaneously onto two locations which are symmetrical with respect to the rotational center of the grating disk. This configuration compensates for the eccentricity of the disk, which often causes measurement error.
- The new reflection optical system eliminates measurement error caused by temperature change which affects the wavelength stability of a semiconductor laser.
- Based on the interference principle, light intensities at the end of optical paths are modulated sinusoidally with rotation of the grating disk changing them into electrical signal.
APPLICATION EXAMPLES
- Robotic engineering
- Sensor for NC machine
- Stage position control
- Direct motor control
- Angle sensor for measuring instruments
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