Document card containing information in holographic form
US4400616A · kind A · utility
55Cited by
6References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1981 |
| Grant date | Aug 23, 1983 |
| Priority date | — |
| Expiry date | Aug 17, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S283/901
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An identification card provided with secret data contained in the form of a wave guide hologram recorded in a layer on the card. Light for developing or displaying the hologram is introduced into a wave guide layer extending along the surface of the card through a grating that admits light only of a given wave length suitable for developing the wave guide hologram. The secrecy of the wave guide hologram is further enhanced by incorporating into the light coupling grating a further hologram by which light only of a predetermined pattern can be coupled to the wave guide for delivery to the wave guide hologram.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.