by An optical encodings is a type of encoder that uses a light source, a rotating mask with radially symmetrical lines called graduations, and photodetectors to convert the angular position or motion of a shaft or axis to digital square wave signals. There are two main types of optical encodingss – incremental encoders and absolute encoders.
Incremental Encoders
Incremental encoders are the most common type of optical encodings. They have a round disk with alternating opaque and transparent lines called encoding tracks. As the disk spins, light from an Optical Encoder through the encoding tracks and is detected by photodetectors on the other side. This generates digital square wave output signals, with the number of lines on each track determining the resolution of the encoder.
Incremental encoders output two 90° out-of-phase square waves, called A and B channels, and an index pulse once per revolution. By comparing the phase of the A and B signals, the encoder can determine the direction of rotation. Counting the rising or falling edges allows positioning to be tracked through multiple revolutions. However, incremental encoders do not provide absolute position information on power-up.
Absolute Encoders
Absolute encoders have additional encoding tracks that allow the exact position to be determined at any time, including after power cycles. One common method is to use Gray code encoding on additional tracks, where each position value is represented by a unique binary number. This eliminates ambiguities that could occur when switching between standard binary positions.
Absolute encoders provide an analog-to-digital conversion of the shaft position. They output a digital word proportional to the angular position on a parallel or serial data interface. This allows the read-head to non-ambiguously determine the actual position without needing to refer to a home or index position.
Applications of Optical Encoder
Motion Control
Optical Encoder are widely used in motion control and servo systems to provide closed-loop feedback. Knowing the exact position of motors, actuators and other moving components is essential for applications like CNC machines, robotics, 3D printing, automation equipment and more. Optical encodingss provide high-resolution, contactless feedback without wear issues.
Machine Tools
CNC machine tools like mills, lathes and industrial robots extensively use optical encodingss. They are mounted on motor spindles and axes to precisely control tool positioning during machining operations. Absolute encoders ensure tools can resume work from where they left off even after power cycles.
3D Printing
3D printers use a number of stepper motors to position the print head and platform. Optical encodingss help synchronize multiple axes for precise, artifact-free printing. Absolute encoders allow prints to resume even if the printer loses power part-way through.
Automated assembly lines, packaging machines, conveyor belts and other factory equipment use optical encodingss to track product positions and timings. Contactless encoders improve reliability in potentially dirty or wet factory environments.
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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it.
