Is used for the traffic circle encoder and this traffic circle encoder the rotary disk

摘要

PURPOSE: To provide a rotary encoder for highly accurately detecting the rotation angle and rotation direction of a rotary shaft with a very simple structure. ;CONSTITUTION: A rotary disk 10 is provided with a digital track 1 constituted of a plurality of slits and an analog track 3 with its light transmission coefficient gradually changed, the light quantity of light passing through the analog track 3 is detected by a photodiode 5b, converted into a digital value by an A/D converter 6 and based on this digitized output signal, the absolute rotary angle of the rotary disk 10 is calculated. A plurality of digitized light quantities are compared by a rotary direction detection part 7 and the increase/decrease thereof is detected and the rotation direction of the rotary disk 10 is calculated. On the other hand, a pulse passing through the digital track 1 is detected by a phototransistor 5a and the relative rotation angle of the rotary disk 10 is calculated based on its pulse number and information on the rotation direction of the rotary disk 10.;COPYRIGHT: (C)1996,JPO