Dot matrix print detector
USH681H · kind H · statutory invention registration
Inventor
Key dates
| Filing date | — |
| Grant date | Sep 5, 1989 |
| Priority date | — |
| Expiry date | — |
Classification
- Technology area (CPC —)General
Abstract
A dot matrix print detector (24) for use in an optical character recognition system for detecting the presence of characters on a document printed in a dot matrix print format is provided. A scanning device (26) generates pixel signals representing pixel values of portions of characters in a predetermined area appearing on the document. A filter (28) functions to generate filtered signals representing energy levels of pixels associated with the edges of the characters. Summation circuitry (30, 32) is provided for determining the energy levels of the filtered signals for the predetermined area and for generating a summation signal. Summation circuitry (38, 40) generates a summation signal representing the energy levels of unfiltered pixel elements or low pass filtered pixel elements. The output of the summation circuitry (40, 32) is applied to a decision circuit (34) for determining the presence of dot matrix print in the predetermined area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.