(19)

(11)

EP 0 783 816 A1

(12)

(43) Date of publication: 16.07.1997 Bulletin 1997/29 (21) Application number: 95932830.0 (22) Date of filing: 29.09.1995

(51) International Patent Classification (IPC):  G03B 17/ 02( . ) H04N 5/ 225( . ) H04S 1/ 00( . ) G03B 31/ 00( . ) H04R 5/ 027( . ) (86) International application number: PCT/GB1995/002310 (87) International publication number: WO 1996/010884 (11.04.1996 Gazette 1996/16)

(84) Designated Contracting States: DE FR GB NL (30) Priority: 01.10.1994 GB 19940019832 (71) Applicant: CENTRAL RESEARCH LABORATORIES LIMITED Hayes, Middlesex, UB3 1HH (GB)	(72) Inventor: SIBBALD, Alastair Middlesex UB3 1HH (GB) (74) Representative: Leaman, Keith, et al  QED Patents Limited, Dawley Road Hayes, Middlesex UB3 1HH Hayes, Middlesex UB3 1HH (GB)