GB679771A - Improvements in or relating to photographic developing machines - Google Patents

Abstract

679,771. Photographic developing apparatus. OZALID CO.,. Ltd., and CROSS, E. L. June 15, 1951 [June 26, 1950], No. 15882/50. Class 98 (ii). Exposed photographic sensitive material, for example paper or other sheet material sensitized with a composition comprising a light-sensitive diazo compound, a coupling component, and an acidic coupling inhibitor, is developed by effecting, external to the development chamber, the substantially complete evaporation of a supply of developing solution comprising an aqueous solution of ammonia or other gaseous alkaline developing agent and the condensing out of the resulting mixture of water vapour and gaseous developing agent of a portion of its water content, and conveying the partially dehumidified mixture to the development chamber. As shown, the perforated upper wall 2 of the development chamber 1 is surmounted by the lower lap of a non-permeable rubber endless belt 3 carried on rollers 4 of which at least one is driven. Ammonia solution is dripfed from the reservoir 8 at a rate controlled by the needle valve 10 into the tray 6 in the evaporating chamber 5 provided with an electric heater 7, and the resultant mixture of ammonia and water vapour is passed along the tube 11 and through the air-cooled condenser 12 to remove a controlled portion of the water vapour content. The mixture is discharged through the slotted tube 15 into the development chamber 1, which is provided with an electric heater 16. Specification 495,392 is referred to.