Production of holograms

Patent 4992346 Issued on February 12, 1991. Estimated Expiration Date:

December 19, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

A method of preparing a hologram having an increased replay wavelength and resulting hologram Patent #: 4769300
Issued on: 09/06/1988
Inventor: Butcher

Inventors

Assignee

Ilford Limited

Application

No. 452843 filed on 12/19/1989

US Classes:

430/2, Composition or product or process of making the same430/1, HOLOGRAPHIC PROCESS, COMPOSITION, OR PRODUCT430/430Bleaching

Examiners

Primary: McCamish, Marion E.
Assistant: Weddington, J.

Attorney, Agent or Firm

Darby & Darby

Foreign Patent References

0230208 EP. 07/13/1987
0332577 EP. 09/13/1989

International Class

G03C 001/04

Foreign Application Priority Data

1988-12-20 GB

Abstract

There is described a method of processing exposed holographic material to obtain holograms having a broader band replay a hologram which is of the silver halide in gelatin binder type which method comprises holographically exposing the holographic material by use of coherent light, developing the holographic image by a chemical process and then treating the material sequentially either firstly with a solution of an anionic surfactant which comprises at least one alkyl group having at least four carbon atoms and then with a solution of a quaternary ammonium compound which comprises at least one alkyl group having from 10 to 18 carbon atoms or a polymeric compound which comprises at least one quaternary ammonium group in the repeating unit or firstly with a solution of said quaternary ammonium compound or polymeric compound and then with a solution of an anionic surfactant, the material being subjected to a silver bleaching step at one stage after development.Preferably the anionic surfactant is present either in an acid stop bath after the development bath or in the bleach bath which is an acid bath. Then after the bleach bath the material is treated with the aqueous solution of the quaternary ammonium compound.