Abstract: An apparatus for automatically counting stacked sheet-like materials having sheet-to-sheet brightness gradients alternating between positive and negative while simultaneously eliminating problems encountered when the sheet edge reflectance characteristics have combined lambertian and specular reflective natures. Rectification of a pitch matched sensor array's data output combined with a selective disposition of the sensor and illumination optical components relative to the sheet edges to be counted based upon the maximum acceptance angle of the optical system yields the improved count data necessary to achieve accurate counting.

Abstract: An apparatus for automatically counting stacked sheet-like materials having sheet-to-sheet brightness gradients alternating between positive and negative while simultaneously eliminating problems encountered when the sheet edge reflectance characteristics have combined lambertian and specular reflective natures. Rectification of a pitch matched sensor arrays data output combined with a selective disposition of the sensor and illumination optical components relative to the sheet edges to be counted based upon the maximum acceptance angle of the optical system yields the improved count data necessary to achieve accurate counting.