EP 0681711 A4 19950726 - MULTIFOCAL CONTACT LENS.
Title (en)
MULTIFOCAL CONTACT LENS.
Title (de)
MULTIFOKALE KONTAKTLINSE.
Title (fr)
LENTILLE DE CONTACT MULTIFOCALE.
Publication
Application
Priority
- GB 9301614 A 19930127
- US 9400918 W 19940125
Abstract (en)
[origin: WO9417435A1] A multifocal contact lens has diffractive power arising from a series of concentric zones each providing an asymmetric retardation of light across the zone width to direct light predominantly into a required order and sign of diffraction. At least some of the concentric zones are shaped so that the step height varies so that it is different in one region (A) of the lens from that in another region (B), whereby the intensity of light associated with an image observed by diffraction at one order in that region (A) of the lens is greater than the light intensity associated with the same image when observed at the same order through another region (B) of the lens.
IPC 1-7
IPC 8 full level
B23K 26/06 (2006.01); G02B 5/18 (2006.01); G02C 7/04 (2006.01); G02C 7/06 (2006.01)
CPC (source: EP)
B23K 26/066 (2015.10); G02B 5/1876 (2013.01); G02B 5/1895 (2013.01); G02C 7/041 (2013.01); G02C 7/043 (2013.01); G02C 7/044 (2013.01); G02C 2202/20 (2013.01)
Citation (search report)
- [A] EP 0457553 A2 19911121 - IOLAB CORP [US]
- [A] US 5089023 A 19920218 - SWANSON GARY J [US]
- [DA] EP 0109753 A2 19840530 - PILKINGTON PERKIN ELMER LTD [GB]
- See references of WO 9417435A1
Designated contracting state (EPC)
AT BE DE DK ES FR GB IE IT NL
DOCDB simple family (publication)
WO 9417435 A1 19940804; AU 6095994 A 19940815; CA 2150478 A1 19940804; EP 0681711 A1 19951115; EP 0681711 A4 19950726; GB 9301614 D0 19930317; JP H08507158 A 19960730
DOCDB simple family (application)
US 9400918 W 19940125; AU 6095994 A 19940125; CA 2150478 A 19940125; EP 94907325 A 19940125; GB 9301614 A 19930127; JP 51729894 A 19940125