Document scan colour data compression - has data compression circuit on OR-gated photocell sensor output to reduce data capacity requirement

摘要

Coloured document scanning using a line method with three scanned segments so that a majority logic type system of data processing can be used to determine the colour of the portion being scanned, whether it differs from the background colour, and to enable a data compression technique to be employed which reduces the data handling requirement of the equipment, e.g. copier or facsimile machine. The document (103) carrying drm (101) is driven from a pulse generator source (109,107) and the document scanned (110) in areas of approx. 1mm x 0.9mm by photocells (119,121) receiving light along optical fibres (113,115). The photocells parallel feed on three highways into the colour decoder (123) which determines which of eight colours has been sesed. The photocells (119,121) also parallel feed into an OR gate logic circuit (129) which outputs into the data compressor (127) for code reduction. The colour decoder (123), the data compressor (127) and the final stage colour coder (131) which otpts the final data are all coupled to the timing pulse generator (107) for synchronisation. PS.