How does the encoder work！

How the encoder works

    A four-phase sine wave signal is combined into A, B, C, D, and each sine wave is composed of a center-axis optical encoder disk, on which there are circular through and dark scribe lines, and photoelectric transmitting and receiving devices are read. Phase difference of 90 degrees (360 degrees relative to a cycle), the C, D signal reverse, superimposed on the A, B two-phase, can enhance the stability of the signal; the other per revolution to output a Z-phase pulse to represent zero reference Bit.

    Because A, B two-phase difference of 90 degrees, can be compared by A-phase or B-phase before the former to determine the encoder forward and reverse, through the zero-bit pulse, the encoder can be zero reference bit. The encoder disc material is glass, metal, plastic, glass disc is deposited on the glass thin groove, the thermal stability, high precision, metal code directly to the disc and pass through groove, not friable, But the metal has a certain thickness, accuracy is limited, its thermal stability is worse than the glass of an order of magnitude, plastic disc is economical, its cost is low, but the accuracy, thermal stability, life are worse .

    Resolution - The number of pass or dark lines that the encoder provides at each rotation of 360 degrees is called resolution, also known as resolution indexing, or directly number of lines, typically 5 to 10000 lines per revolution.

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