(19)

(11)

EP 0 527 847 A1

(12)

(43) Date of publication: 24.02.1993 Bulletin 1993/08 (21) Application number: 91909034.0 (22) Date of filing: 17.04.1991

(51) International Patent Classification (IPC):  G02B 1/ 04( . ) G03C 1/ 005( . ) G02B 5/ 23( . ) (86) International application number: PCT/US1991/002634 (87) International publication number: WO 1991/016644 (31.10.1991 Gazette 1991/25)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IT LI LU NL SE (30) Priority: 17.04.1990 US 19900510146 (71) Applicant: WASSERMAN, Nelson West Newton, MA 02165 (US)	(72) Inventors: WASSERMAN, Nelson West Newton, MA 02165 (US) REID, Jerome, L. Wayland, MA 01778 (US) DO, Pauline Newton, MA 02159 (US) (74) Representative: Feldkamp, Rainer, Dipl.-Ing.  Patentanwälte Wallach, Koch, Dr. Haibach, Feldkamp Postfach 12 11 20 D-80035 München D-80035 München (DE)