Patent US3733198A successfully refreshed from Google Patents.
← Back to Patent Explorer
US3733198A Expired / Lapsed US ⏱️ 0.0 years remaining

Direct positive processes utilizing silver halide internal latent image emulsions containing high concentration of heterocyclic thione antifoggants

Assignee: Agfa Gevaert NV
•
Filing: 1971-02-01
•
Granted: 1973-05-15
•
Expires: 1991-02-01
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract IN A KNOWN METHOD OFF SUCH WAVELENGTH TO PROVIDE PERMANENT RECT POSITVE IMAGES BY EXPOSING A LIGHT-SENSITIVE MATERIAL CARRYING A SILVER HALIDE EMULSION LAYER OF THE TYPE FORMINGA LATENT IMAGE PREDOMINANTLY IN THE INNER PART OF THE SILVER HALIDE GRAINS, I.E. A SO-CALLED INTERNAL IMAGE EMULSION, TREATING THE EXPOSED MATERIAL WITH A SURFACE DEVELOPER AND OVERALL EXPOSING THE MATERIAL DURING THIS TREATMENT TO ACTINIC LIGHT OF LOW INTENSITY, AN IMAGE HAVING MINIMUM DENSITY AND CONTRAST IS OBTAINED BY INCORPORATING WITHIN THE EMULSION LAYER AFOG-INHIBITING COMPOUND OF THE CLASS OF THE HETEROCYCLIC THIONE COMPOUNDS IN AN AMOUNT OF AT LEAST AOUT 0.1 MOLE PER 100 MOLE OF SILVER HALIDE AND WHICH IS SUBSTANTIALLY LARGER THAN NORMAL FOG-INHIBITING AMOUNTS. THE CONCEPT CAN BE APPLIED TO THE FORMATION OF BLACK AND WHITE IMAGES AS WELL AS TO COLORED IMAGES.

Inventors

  • 👤 G Vanreusel
  • 👤 Pee P Van
  • 👤 Laet J De

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 23:30
CPC Classifications
G; G03; G03C; G03C7/00; G03C7/30; G03C7/3022; G03C1/00; G03C1/005; G03C1/485; G03C1/48538; G03C1/48592

Claims Analysis

Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-05-14 1976-11-13 1977-05-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-05-14 1980-11-13 1981-05-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-05-14 1984-11-13 1985-05-15 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag