Abstract: A video image of a region including characters recorded on a document is converted into electric signals. From the electric signals unit signals corresponding to subregions obtained by dividing the region is picked up. Horizontal, vertical and slanted stroke components included in each of the subregions are detected from the unit signals. The detected numbers of the horizontal, vertical and slanted stroke components are counted. The ratio of the counted numbers of the slanted stroke component to the total of the horizontal, vertical and slanted stroke components is calculated. The characters on the document is judged as handwritten ones and machine-printed ones if the ratio is above and not above a predetermined threshold, respectively. The threshold is preferably set at 0.2.

Abstract: An optical character reader distinguishes between black and white image signals by comparing a center reader with readings from surrounding areas. Variations on the surface of a paper bearing the image can add or subtract values so that the comparison may be in error. The invention overcomes the problem by using logic circuits to add, subtract and compare signals out of a mask in order to improve the accuracy of the comparison between the center reading and the readings from the surrounding areas.

Abstract: The disclosure describes a character recognition apparatus comprising a scanner for optically scanning a prescribed area and outputting a scanned signal, a binary processing circuit for receiving the scanned signal and producing a plurality of binary signals, a counting mechanism for counting black meshes in the scanned area, a counting mechanism for counting insulated meshes, a mechanism for calculating the ratio of the number of black meshes and the number of insulated meshes, and a mechanism for selecting one optimum binary signal from the plurality of binary signals on the basis of a comparison of the ratios.

Abstract: A detector for use in a mail sorter is positioned along a path over which articles (letters, postcards, etc.) travel while in an upright position. A problem with such paths is that sometimes articles are overlapped, and sometimes small articles are hidden behind large articles. The invention detects such overlaps by (1) detecting height changes of any single article which trips a detector only once, and (2) forcibly displacing one article relative to the other of two overlapped articles. The change of length resulting from the forced displacement is detected.