(19)
(11) EP 0 272 218 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
02.08.1989 Bulletin 1989/31

(43) Date of publication A2:
22.06.1988 Bulletin 1988/25

(21) Application number: 87810745.7

(22) Date of filing: 11.12.1987
(51) International Patent Classification (IPC)4: G03C 5/44, G03H 1/18
(84) Designated Contracting States:
BE CH DE FR GB IT LI NL

(30) Priority: 17.12.1986 GB 8630187

(71) Applicant: ILFORD Limited
Mobberley Knutsford Cheshire WA16 7HA (GB)

(72) Inventors:
  • Groves, Trevor
    Wincham Northwich (GB)
  • Hopwood, Antony Ian
    Withington Manchester M20 9DU (GB)
  • Clark, John Andrew
    Altrincham Cheshire WA15 9HY (GB)
  • Briggs, Timothy Nigel
    Sandbach Cheshire CW11 9BU (GB)


(56) References cited: : 
   
       


    (54) Method of preparing a hologram


    (57) Method of preparing a hologram which is of the silver halide in gelatin binder type which method comprises holographically exposing, developing, and bleaching holographic materials by means of a rehalogenation bleach bath, which contains a water-soluble halide and a ferric salt of an acetic acid derivative. Holograms thus prepared exhibit less haze and stain.







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