Instrument for scanning document for quality

Claim 1

A scanning apparatus to detect and count speckle on an object surface including: an objective lens disposed on an optical axis relative to said object surface for scanning said object surface, a beam divider disposed in said optical axis behind said objective lens to divide said optical axis into transmitted and reflected components, a control aperture disposed along one of said components of said optical axis in conjugate relationship to said object surface, a counter aperture, smaller than said control aperture, disposed along the other of said components of said optical axis in conjugate relationship to said object surface, said control aperture and said counter aperture being partially optically superposed relative to said optical axis, a control photosensitive element in optical communication with said control aperture, said control photosensitive element operatively connected to a gate circuit and maintaining said gate circuit open when exposed to light above a threshold level and closing said gate circuit when exposed to light below said threshold level so that said gate circuit is either open or closed, a counter photosensitive element in optical communication with said counter aperture, said counter photosensitive element operatively connected, through said gate circuit, to a pulse counter whereby signals from said counter photosensitive element are counted when said gate circuit is open and said signals are not counted when said gate circuit is closed.