EQUIPMENT FOR REGULATION OF ORIGIN

PURPOSE:To enable the high accuracy regulation of the error range settled with the resolution of an encoder, by pure-binary-coding the signal from a rotary encoder of absolute type and by generating the complement value. CONSTITUTION:The code of electric signal of rotary encoder 2 of absolute type is converted to an easily calculable pure binary number with a conversion circuit 61. The complement value generation circuit 62 generates 2 complement values of the output number of the circuit 61 and outputs then to an adder 63 when the machine is at an origin. The output signal of adder 63 is zero when the machine is at the origin and increases at the same rate with the increase of input from the encoder 2. As a result, the mechanical origin coincides with the zero point of electric signal. Furthermore, the easy coincidence of them with the high accuracy of the error range of the minimum angle settled with the resolution of encoder can be provided without the necessity of mechanically difficult regulation.