Encoder : Part 1 Encoder Mean ?

What does the word encoder mean? The encoder is an electromechanical device that can measure displacement. Encoders are normally digital displacement transducers, consisting of a mechanical element and a sensing head, typically of optical type.

The mechanical element can be a disc (for rotary type encoders) or a ruler (for linear type encoders) with deposited or carved patterns. The sensing head includes a light source (LED) and a light sensor (photo detector) to read the generated code (the encoder output).

The Optical Encoders typically consist of a rotating and a stationary electronic circuit. The rotor is usually a metal, glass, or a plastic disc mounted on the encoder shaft. The disc has some kind of optical pattern, which is electronically decoded to generate position information.

The rotor disc in absolute optical encoder uses opaque and transparent segments arranged in a gray-code pattern. The stator has corresponding pairs of LEDs and photo-transistors arranged so that the LED light shines through the transparent sections of the rotor disc and received by photo-transistors on the other side. After the electronic signals are amplified and converted, they are then available for the evaluation of the position

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