(19)

(11)

EP 0 570 567 A1

(12)

(43) Date of publication: 24.11.1993 Bulletin 1993/47 (21) Application number: 93900271.0 (22) Date of filing: 09.12.1992

(51) International Patent Classification (IPC):  G09G 3/ 36( . ) (86) International application number: PCT/GB1992/002282 (87) International publication number: WO 1993/012516 (24.06.1993 Gazette 1993/15)

(84) Designated Contracting States: BE DE ES FR NL (30) Priority: 09.12.1991 GB 19910026127 (71) Applicant: GEC-MARCONI LIMITED Stanmore, Middlesex HA7 4LY (GB)	(72) Inventors: YEOH, Colin, Teck, Hooi London NW10 7EL (GB) AULTON, Derek James Edgware, Middlesex HA8 8TX (GB) WITHERS, Nicholas, Hugh South Oxhey, Hertfordshire WD1 6HQ (GB) (74) Representative: Keppler, William Patrick  The General Electric Company, p.l.c. GEC Patent Department Waterhouse Lane Chelmsford, Essex CM1 2QX Chelmsford, Essex CM1 2QX (GB)