Caere Corporation

William R Smith

Peter A Ronzani

Serge L Blanc

Richard E Kumpf

Anthony Sun

A matrix extractor is described which is particularly useful for extracting data from a memory which contains representations of optically scanned characters. The method and apparatus of the present invention permits the isolation of packets of data in the memory and the determination of the location of these packets. Data representing the packets is then extracted from the memory for character recognition. The isolation of packets in memory greatly reduces the amount of data which must be processed by the recognition processor and provides much more reliable recognition.

OCR Matrix extractor

An apparatus for processing video signals received from an optical scanner is described. A comparator means is used for comparing the video signals with a dynamic threshold voltage. This threshold voltage is generated by a peak detector circuit which also receives the video signals. The peak detector circuit includes decay means for decaying signals representative of the detected peaks at a predetermined rate. This thresholding technique provides compensation for a wide dynamic range of video signals received from a photodiode array.

Apparatus for processing video signals received from an optical scanner

A hand-held optical reading device, commonly called a wand, for reading a field of printed characters. The wand includes a light source for illuminating the printed characters, a photodiode array and a lens for collecting reflected light and forming an image on the diode array corresponding to the printed characters. Apertures are formed in the lower portion of the wand housing for projecting light from the light source onto the surface upon which the characters are printed. The projected light forms a pattern on the surface which is used for visually aligning the wand with respect to character field.

Hand-held optical character recognition wand with visual aligner

An optical reader for recognizing printed characters, such as alpha-numeric characters, is disclosed. The characters are scanned in parallel, vertical slices by a photodiode array contained in a hand-held wand which is manually moved over the printed characters. The resultant video signals are examined for predetermined features, such as gaps, bars, strokes, etc. These features are encoded into a digital word for each slice. A logic tree analysis is used in which each new digital word is compared to words along the tree to direct the analysis to branches or substances. The continued comparison leads to a positive recognition of a single character. The raw video is not stored as in prior art systems, but rather the video signals are processed in a serial manner with feature identification occurring without storage. The processing circuitry thus is efficiently used since the video signals are processed as they occur.

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Mountain View, CA, United States of America

William R Smith