(19)

(11)

EP 0 890 295 A1

(12)

(43) Date of publication: 13.01.1999 Bulletin 1999/02 (21) Application number: 97908378.0 (22) Date of filing: 20.03.1997

(51) International Patent Classification (IPC):  H04S 1/ 00( . ) (86) International application number: PCT/GB1997/000772 (87) International publication number: WO 1997/037514 (09.10.1997 Gazette 1997/43)

(84) Designated Contracting States: DE DK FR GB NL (30) Priority: 30.03.1996 GB 19960006814 (71) Applicant: CENTRAL RESEARCH LABORATORIES LIMITED Hayes, Middlesex, UB3 1HH (GB)	(72) Inventors: CLEMOW, Richard Hayes, Middlesex UB3 1HH (GB) NACKVI, Fawad Hayes, Middlesex UB3 1HH (GB) (74) Representative: Leaman, Keith, et al  QED Patents Limited, Dawley Road Hayes, Middlesex UB3 1HH Hayes, Middlesex UB3 1HH (GB)