Angle sensing instrument for monitoring position of shaft with limited rotation has codes printed or inscribed on disc and read by optical detector

摘要

The shaft (1) rotates through a limited arc inside a housing (2). A disc (3) with optical codes may be connected to the shaft by planetary gearing (6-8), and the movement arc of the disc may be limited. An optical detector (4) is positioned to read codes printed or inscribed or pierced through the edge of the disc.