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.

Abstract: A character recognition circuit slices the character signal received from an optical scanner and counts a number of black bits at multiple levels. The number of black bits are normalized in accordance with the character row length. A pair of level judging circuits responds to the normalized black bits at the respective multiple levels to derive slicing levels for both the character and the background. Responsive thereto a binary signal is produced in accordance with the slice level. Thus, the differences in the background signals do not have an effect upon the recognization of the character signals.

Abstract: A character segmenting apparatus has an optical scanner for scanning the surface of an article of mail. The scan is in a direction which is substantially perpendicular to the direction of the relative movement between the optical scanner and the mail article. The scan generates a pattern signal which is then recurrsively compressed and updated in the width of a black picture element contained in the pattern signal. A character segmenting signal is produced when no black picture element exists in a portion of the pattern signal, delivered from the optical scanner, which corresponds to the black picture element contained in the compressed pattern signal. Size and position information of a whole segmented character is developed in response to the character segmenting signal.

Abstract: A postal code distinguishing apparatus extracts characters from an address code appearing on a mail article, forms words from the extracted characters, stores in a memory a set of key words (i.e., "ATTN", "TEL", "P.O. BOS", etc.) which indicate that a numeric code on the same line is not a postal code, compares the key words with the extracted words, and sorts the mail articles accordingly. In this manner, the various lines of the address code are "eliminated" such that the numeric code on the remaining line is automatically read out as the postal code.

Abstract: A binary pattern signal producing apparatus for optical character recognition comprises a pre-scanning section for determining an area containing the information to be scanned, a scanning apparatus for producing a signal in accordance with the luminance of the scanning area, an automatic gain control circuit for controlling the level of the information signal in accordance with the level of a portion of the same information signal representing less than the entire scanned area, and a comparison circuit responsive to the output of the automatic gain control circuit for generating the binary pattern signal. In addition to or in place of a gate circuit which is used to provide only a portion of the information signal to the gain control terminal of the automatic gain control device, the apparatus may include noise eliminating circuitry for removing pulsive noise from the gain control signal.