GB391174A - Process for the production of two- or three-colour photographs and cinematograph films - Google Patents

Abstract

391,174. Colour photography. ANDERSEN, P. S. R., 14, Ulrich Birchs AllÚ, Copenhagen. Oct. 12, 1931, No. 28325. Convention date, Oct. 17, 1930. [Class 98 (ii).] Two- or three-colour photographs and kinematograph films are obtained by exposing a double-coated negative film having on the front side of the support B an orthochromatic emulsion layer A mixed with or applied over a yellow filter dye, and a panchromatic rear layer C ; after developing, the images in the two layers are converted into hardened gelatin reliefs, that in the layer A is allowed to absorb a red dye in the unhardened portions and a layer of grease is applied by a roll passed over the surface of the images in the layer C, as indicated in Fig. 4 ; a positive film or paper is then pressed into contact with the layer C and exposed to light and the light and grease impressions are subsequently converted into appropriate coloured images. For three-colour work, the exposed positive is developed and the image converted, in the dark, into a Prussian blue image ; the layer of grease is then removed and the latent green image is deveoped and converted to a chrome yellow image by a lead toning bath ; finally, the positive is exposed to light and the remaining image is developed and converted to a red image by a uranium toning bath. Alternatively, the images may be converted into diachromes. For two-colour work, the emulsion in the layer A is arranged to pass only red rays which are recorded in the layer C ; the procedure is otherwise similar to that for three-colour work. The Specification as open to inspection under Sect. 91 describes a modified three-colour process according to which the negative images in the layer C are treated according to the pigment process so as to absorb colour substances which are transferred directly to the positive. This subject-matter does not appear in the Specification as accepted.