EP 0746472 A4 19970305 - DIFFRACTIVE DEVICE WITH ENHANCED ANTI-COPYING PROTECTION
Title (en)
DIFFRACTIVE DEVICE WITH ENHANCED ANTI-COPYING PROTECTION
Title (de)
DIFFRAKTIVES GERÄT MIT KOPIERSCHUTZ
Title (fr)
DISPOSITIF DIFFRACTIF AVEC PROTECTION CONTRE LE COPIAGE AMELIOREE
Publication
Application
Priority
- AU 9500062 W 19950213
- AU PM382994 A 19940214
Abstract (en)
[origin: WO9521747A1] When a diffractive device (2) is illuminated by a light source, it generates one or more diffraction images which are observable from particular ranges of viewing angles around the device. The device comprises a substrate (6), a diffractive structure (3) embossed into or adhered onto the substrate, a first substantially transparent layer (7) over the diffractive structure, light splitting means (8, 10, 11) over the first substantially transparent layer, and a second substantially transparent layer (9) over the light splitting means. The light splitting means protects the diffractive device against replication using near field or far field imaging procedures which require coherent light illumination.
IPC 1-7
IPC 8 full level
B42D 15/10 (2006.01); B42D 25/328 (2014.01); G02B 5/18 (2006.01); G03H 1/00 (2006.01); G03H 1/02 (2006.01); G06K 19/16 (2006.01)
CPC (source: EP)
B42D 25/328 (2014.10); G03H 1/00 (2013.01); G06K 19/16 (2013.01); G03H 1/0244 (2013.01); G03H 1/0256 (2013.01); G03H 2001/0027 (2013.01); G03H 2001/263 (2013.01); G03H 2001/264 (2013.01)
Citation (search report)
- [A] WO 9007133 A1 19900628 - AUSTRALIA RESERVE BANK [AU]
- See references of WO 9521747A1
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
WO 9521747 A1 19950817; AU PM382994 A0 19940310; EP 0746472 A1 19961211; EP 0746472 A4 19970305; JP H09508594 A 19970902
DOCDB simple family (application)
AU 9500062 W 19950213; AU PM382994 A 19940214; EP 95908825 A 19950213; JP 52085595 A 19950213