U.S. Philips Corporation

Robert Bodart

Jean P Werts

Pol A Gustin

Raymond G Schayes

Jean-Pierre Werts

Michel F Berck

Facsimile transmission arrangement for documents which are divided into document lines and which contain photographs in addition to text. The text zones of a document line are subjected to a normal run-length coding. The photo zones are subjected to a photo coding. Therein, areas which have a uniform grey tone are first converted into a sequence of binary '0' and '1' elements which succeed each other in a regular alternation. Thereafter a first and a second code word are generated which indicate the number of binary '0' elements and the number of binary '1' elements, respectively of the sequence. These code words are transmitted to the receiver either directly or after having been converted into a Huffman code.

Facsimile transmission arrangement

Described is the regeneration of dial pulses in the signalling system CCITT type B. The dial pulses are regenerated by a combined regeneration process comprising a reduced process with two sampling instants (10 ms, 30 ms) and an inverse process with four (anisochronous) sampling instants (10 ms, 30 ms, 52 ms, 72 ms). The reduced process is started by the stop-start transition at the beginning of the first of a series of dial pulses and the inverse process by the start-stop transition which occurs at the end of the series of dial pulses.

Arrangement for regenerating start-stop signals and dial pulses

A start-stop signal, such as a telex signal, having a stop polarity which is maintained for a period of time after a start-stop transition, is regenerated as a plurality of signal samples which are stored and then used to form an isochronous output signal. The invention resides in having unequal time intervals between the signal samples so that a range of periods of time for the stop polarity can be catered for to produce an isochronous output-signal of satisfactory duration.

Method of and arrangement for regenerating start-stop signals

Arrangement for restituting selection signals from a received isochronous signal which permits an ample variation in the number of consecutive bits of start polarity A and stop polarity Z, which represent respective values of the selection signals. This arrangement can handle 2, 3 or 4 bits A and 1,2 or 3 bits Z and restitute therefrom the intervals of stop polarity Z with a fixed duration and the intervals of start polarity A with a variable duration between two limits.

Arrangement for restituting selection signals

An arrangement is described wherein the leading edge of an A-pulse in a telex signal is additionally delayed relative to the trailing edge, in order to prevent a specified upper limit from being exceeded at the conversion into an isochronous signal. For Z-pulses, a high upper limit for the number of bits is prescribed which, in cascade connections, may lead to degradation of the Z-pulses. The arrangement further enables, because of an additional delay of the leading edge of the Z-pulse relative to the trailing edge, the maximum number of bits in the isochronous signal to be one less than the maximum permissible number.

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Brussels, Belgium

Robert Bodart