Infusion pump with associated rotary encoder.

摘要

A rotary encoder comprises a rotary plate having a plurality of primary slits defined in the rotary plate in a circular row coaxial with the axis of rotation of the rotary plate. The rotary plate also has at least one reference slit defined therein at a position radially of the circular row of the primary slits. A primary photoelectric detector including a source of light and a photo-sensor positioned one above the other with the circular row of the primary slits intervening therebetween is used to detect the passage of the primary slits therethrough while an auxiliary photoelectric detector including a source of light and a photo-sensor positioned one above the other with the path of travel of the reference slit intervening therebetween is used to detect the passage of the reference slit therethrough.