(19)

(11)

EP 0 502 911 A1

(12)

(43) Date of publication: 16.09.1992 Bulletin 1992/38 (21) Application number: 90917584.0 (22) Date of filing: 28.11.1990

(51) International Patent Classification (IPC):  H04B 1/ 20( . ) H04N 5/ 50( . ) H04N 7/ 20( . ) (86) International application number: PCT/GB1990/001853 (87) International publication number: WO 1991/008645 (13.06.1991 Gazette 1991/13)

(84) Designated Contracting States: DE FR (30) Priority: 28.11.1989 GB 19890026882 (71) Applicant: ZETA TECHNOLOGY LIMITED Cheshire SK9 7QN (GB)	(72) Inventors: McCORMACK, James, Owen Lease Farm Cottage Cheshire SK9 7QN (GB) McCORMACK, Peter, Robert 37 Essex Close Cheshire CW12 1SH (GB) (74) Representative: Quest, Barry  Wilson, Gunn, M'Caw & Co., 41-51 Royal Exchange, Cross Street Manchester M2 7BD Manchester M2 7BD (GB)