IP Library › Granted Patent US 4,832,445
Granted Patent Utility
US 4,832,445 · App. 06/864,193

Security diffraction devices difficult to exactly duplicate

Inventors: Kenneth A. Haines, Robert H. Weller
Patented Case View Patent ↗
Granted: May 23, 1989 Filed: May 16, 1986
Inventors
Kenneth A. Haines
Robert H. Weller
Assignee (at issue)
AMERICAN BANK NOTE HOLOGRAPHICS, INC.

This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.

Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 4,832,445
App. No.
06/864,193
Filed
1986-05-16
Granted
1989-05-23
Kind
A