Electronic Products bvba EN
How it works
Encoders: digital or analog


Both codestrip and encoder must have exactly the same window sizes and distances between windows in order to work properly. Movement of the encoder with respect to the codestrip changes resulting window size gradually as a function of the displacement. When both windows match each other, light can pass from the light source in the encoder through the codestrip, through the windows of the encoder onto the photocells in the encoder.( sometimes the photocells are made just the same size(s) and distances as the windows resulting the same effect ). When the windows don't match at all, and as the bar ratio equals the window size, no light can reach the photocells. The number of the dark/light transitions for a given displacement gives relative position.


In order to detect the direction of the relative motion, another set of photocells is positioned with a half a window offset from the former set of photocells. The detection of the light by one set before the other set allows the user to identify the direction of the movement.


This technique applies to both encoder types: transmissive and reflective. Where transmissive codestrips have transparent windows, reflective codestrips have reflective windows.


Both encoder systems exist with analog and digital outputs.



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