Apparatus for discrimination of sheet transfer condition

Abstract

An apparatus for discriminating a sheet transfer condition has two opposite rollers at least one of which has an axis of rotation which is movable toward and away from that of the other roller. The thickness of a sheet nipped between the two rollers is detected while the rollers are rotated, through a displacement of the movable roller. The thickness is computed utilizing a value provided by integrating, averaging, smoothing or other wise processing on a time series basis the displacement which occurs during a time period for which at least one of the rollers completes an integral number of rotations. The thickness is computed by subtracting a so processed value for a case wherein a sheet is absent between the rollers from a so processed value for a case wherein a sheet is present between the rollers. Where the rollers have a common diameter, the time period which they take to complete an integral number of rotations is employed as the aforesaid time period for an integral number of rotations. Where the diameters of the rollers differ from each other, the time period for a larger diameter roller to complete an integral number of rotations or the time period for both the rollers to complete their integral numbers of rotations is selected as the same time period concerned.

Dependencies are inferred from the claim text.