3620590 is referenced by 28 patents.

A holographic method and apparatus for storing and retrieving information only by authorized persons, particularly used for identifying the bearer of a record of such information, comprises storing the information on a record medium as a hologram, scrambling the image of the information on the hologram so that it cannot be recreated except by authorized persons using a master code, and then recreating the scrambled holographic image using apparatus that eliminates the effect of the master code. The information is recreated and displayed using apparatus for displaying holograms which further includes a master code hologram that is reciprocated across the optical axis of the display apparatus so as to eliminate the scrambling effect of the master code on the hologram. The master code may consist of a series of parallel randomly undulating lines.

Title
Holographic method and apparatus for information storage and retrieval
Application Number
04/828,184
Publication Number
3620590
Application Date
May 27, 1969
Publication Date
November 16, 1971
Inventor
Ronald C Barker
Agent
Seidel Gonda & Goldhammer
Assignee
Applied Laser Technology
IPC
G09f 03/03
G02b 27/22
G07C 09/00
G03H 01/04
G06K 19/16
G06K 19/14
View Original Source