Patent GB-417722-A (GB)
Title: Improvements in or relating to combined color-picture and sound-record kinematograph films
IPC: G03C7/24
Filed: 1933-04-05
Abstract: 417,722. Combined sound and picture films. THORNTON, J. E., 8, Hill Street, Jersey, Channel Islands. April 5, 1933, No. 10160. [Class 40 (ii).] Consists in a process whereby the silver images on the sound track and the kinematograph picture portion of a positive combination record film, more particularly a multi-colour film, are changed simultaneously so that the picture record becomes relief colloid images in one or more colours, and the sound record becomes a relief colloid record in a different colour, (the term " colour " including black). According to the invention, one or more tapes or ribbons, carrying or consisting of a colloid mixed with colouring matter in parallel stripes of different colours, is or are applied adherently to the face of a positive sound and picture film after it has been produced by printing, developing, and fixing in the usual way ; the combination is acted upon by a bleaching and hardening agent, which has the effect of rendering insoluble the coloured colloid in contact with the silver images, after which the soluble part of the coloured colloid is dissolved out, and then the silver salts are dissolved from the film, leaving coloured colloid images in relief. The colour applied to the sound track is different from that or those used for colouring the pictures, for example, the pictures may consist of superposed sets of images respectively coloured orange-red and blue-green, whilst the sound record is coloured black. Hardening of the positive silver print is necessary if the removal of the unwanted coloured colloid is effected by washing out with warm water. Such hardening may be done before or after development, e.g. during manufacture of the sensitized film or simultaneously with fixing. Numerous variations in the ways of carrying out the invention, and in applying it to the production of films having monochrome pictures or multicolour pictures constituted by two, three, or four colour components are described and illustrated. For example, the different component images may be printed and coloured upon a single surface of the film, using a multiple-width film and coloured ribbon, the film being afterwards slit longitudinally and the images superposed. The invention can also be applied to films having two or more sound tracks. The ribbon used for applying the colours may be a strip of porous paper coated on one side with parallel stripes of differently coloured colloid. Several ways of making the coated ribbons, which may be perforated along one or both edges, are described. The colloid preferably used as a coating is a mixture of clear soft gelatine and glue, but various other suitable substances are specified. Any suitable pigment or dye may be incorporated in the colloid. Ribbons of colloid having no paper backing may be used, and methods of making such ribbons are described. To produce the effect of a black sound record, it may be coloured red and covered with a green blank stripe on the other side of the film. The Figure shows a machine for carrying out the process. The film on which the pictures and sound record have been printed by usual photographic processes, and which has been hardened and dried, is drawn from a roll F and is passed through a damping trough F<2>, after which it is led between two dry colouring-ribbons 2, 3 which are fed from rolls L. The colloid faces of the ribbons are pressed into contact with the opposite sides of the film by pressure rollers A<1>, B<1>, one set of rollers being carried by a weighted frame B. The ribbons are thus caused to adhere closely to the film, and the combination then passes through a drying chamber K, and into a bleaching bath M<1>, wherein the silver images are bleached, and the colloid in contact with the images is rendered insoluble and amalgamates with the hardened gelatine of the silver image layer. Next, the unwanted soluble coloured colloid is dissolved in a water bath M<2>, and on emerging from this, the combined film and ribbons pass between rollers m<1> which strip away the paper backings of the ribbons. The film then passes through a fixing bath M<3>, which removes the soluble silver salts, and finally through one or more washing tanks M<4>, M<5> and a drying chamber P. Alternatively, the film may be treated in the last tank, and by means of sprayers N, with a hardening and flexing solution of alum and glycerine, or with a varnish. The bleaching and hardening bath may be of the kind known by the Registered Trade Marks " Ozobrome " and " Carbro " ; examples of suitable reagents are given. Among the various modifications of details referred to are the following :-To secure better adhesion between the ribbons and the film, both may be passed through a weak alkaline bath, which may contain glycerine and glue. Bleaching and hardening may be effected in separate operations, and the bleaching reagent may be incorporated with the colloid before application of the ribbons to the film; or the printed film may be soaked in chromic acid before the ribbons are applied. The ribbons may be pressed into contact with the film under water, to ensure good contact. Instead of drying the original silver print film, and reeling it as at F in the apparatus shown, the film may pass, whilst wet, straight from the developing machine to the ribbon-applying machine. The apparatus, processes, or materials described in Specifications 224,569, 232,302, 233,985, 246,282, 285,227, 285,228, 303,262, 316,388, [all in Class 98 (ii)], and 373,312, [Group XX], may be used in carrying out the invention. Specifications 224,573, [Class 98 (ii)], and 377,706, [Group XX], also are referred to.