SCANNING SYSTEMS

摘要

A hand-held scanning device is moved across a line of print and generates a two-dimensional scan of the print. A line array of photo diodes performs the scan in one direction and the movement across the paper generates strobe pulses each of which allows one scan of the array to be passed to a store from which a domestic T.V. set can be fed to provide an enlarged display. May be used as a reading aid for partially sighted people or as an input device for an optical character recognition machine. In the case of a reading aid using a T.V.-type raster display, the store is organized to allow new array scans to be written in at a variable rate dependent on hand motion while the contents of the store are read out repetitively and non-destructively at a constant line-by-line rate suitable for the T.V. raster.