The aim of the present invention is to provide a projector device and a medical device with said projector device, said projector device facilitating an improved measurement of the local refractive power of an optical body, in particular an eye. A polymer housing houses the position indicator display and mechanism and a one-piece clear polymer cover encloses the position indicator display and mechanism in the polymer housing. Assuming that the shorter distance between the shortest distance from a rotation axis of a target rod to the side face of the reaction vessel and the shortest distance from the rotation axis of the target rod to the wall face is L, and the outer diameter of the glass particles deposit deposited on the target rod is d, L is greater than d. Thus, the time required for opening the choke valve can be controlled in accordance with the level of the environmental temperature of an engine, thereby providing the stabilization of the warming operation of the engine and a reduction in fuel consumption. In the region of the slaving section, at least one of the shaft or the hub demonstrates at least two retaining sections angularly displaced to each other around the longitudinal axis.