(19)

(11)

EP 0 250 532 A1

(12)

(43) Date of publication: 07.01.1988 Bulletin 1988/01 (21) Application number: 87900233.0 (22) Date of filing: 23.12.1986

(51) International Patent Classification (IPC):  H04N 7/ 015( . ) H04N 7/ 12( . ) (86) International application number: PCT/GB1986/000794 (87) International publication number: WO 1987/004032 (02.07.1987 Gazette 1987/14)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 24.12.1985 GB 19850031778 (71) Applicant: BRITISH BROADCASTING CORPORATION London W1A 1AA (GB)	(72) Inventors: WELLS, Nicholas, Dominic Sussex BN2 2ZA (GB) KNEE, Michael, James Surrey GU1 1EP (GB) SANDBANK, Charles, Peter Surrey RH2 9NA (GB)