Security diffraction devices difficult to exactly duplicate
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
May 23, 1989
Grant Date -
N/A
app pub date -
May 16, 1986
filing date -
May 16, 1986
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
Holograms, including diffraction gratings, and methods of making them, that reconstruct an image which changes as the hologram is tilted with respect to the viewer and in a manner that images reconstructed from copies made of the hologram in monochromatic light do not have that motion. The hologram is a valuable security device for authenticating documents or objects to which it is attached since it is extremely difficult to duplicate.
First Claim
Family
International Classification(s)
- [Classification Symbol]
- [Patents Count]
Cited Art Landscape
Patent Citation Ranking
Advertisement
Advertisement
Advertisement
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully