(19)

(11)

EP 0 173 721 A1

(12)

(43) Date of publication: 12.03.1986 Bulletin 1986/11 (21) Application number: 85901308.0 (22) Date of filing: 14.03.1985

(51) International Patent Classification (IPC):  G03B 21/ 132( . ) (86) International application number: PCT/AU1985/000049 (87) International publication number: WO 1985/004264 (26.09.1985 Gazette 1985/21)

(84) Designated Contracting States: AT BE CH DE FR GB LI LU NL SE (30) Priority: 14.03.1984 AU 19840004057 (71) Applicant: RETEST MATERIALS PTY. LIMITED Wahroonga, NSW 2076 (AU)	(72) Inventor: WILSON, Mervyn Wahroonga, NSW 2076 (AU)