(19)

(11)

EP 0 151 155 A1

(12)

(43) Date of publication: 14.08.1985 Bulletin 1985/33 (21) Application number: 84902771.0 (22) Date of filing: 16.07.1984

(51) International Patent Classification (IPC):  G12B 15/ 02( . ) H01S 3/ 04( . ) (86) International application number: PCT/AU1984/000137 (87) International publication number: WO 1985/000688 (14.02.1985 Gazette 1985/04)

(84) Designated Contracting States: AT BE CH DE FR GB LI LU NL SE (30) Priority: 22.07.1983 AU 19830000439 (71) Applicant: THE COMMONWEALTH OF AUSTRALIA Canberra, Australian Capital Territory 2600 (AU)	(72) Inventors: O'CONNOR, Graham, Geoffrey Lower Mitcham, S.A. 5062 (AU) TAYLOR, Donald George Street Greenock, S.A. 5360 (AU) (74) Representative: Opperman, Stuart Richard, et al  Haseltine Lake & Co. Hazlitt House 28 Southampton Buildings Chancery Lane London WC2A 1AT London WC2A 1AT (GB)