Shaft-type linear motor

摘要

An image reading apparatus comprising a fluorescent lamp for lighting an original document; an inverter circuit for turning on the lamp; a plurality of optical part carrying sliders carrying the lamp on one of the sliders; and a magnetic encoder including a magnetism detecting element, wherein the detecting element and the inverter circuit (and an operation panel having a LCD) are spaced from each other and are located at opposite sides of a center of a travel region of the sliders. A shaft-type linear motor comprising a yoke stationarily arranged along the moving direction of a movable piece and made of a ferromagnetic material. A shaft-type linear motor comprising a shaft-type stator and a movable piece reciprocatable along the stator, wherein the stator and the movable piece are covered with a protection cover. The cover may be made of a ferromagnetic material.