Abstract: A heat transfer sheet having a heat transfer layer on one surface of a base sheet, said heat transfer layer being formed of a material containing a dye substantially dissolved in a binder with a weight ratio of the dye to the binder (dye/binder ratio) of 0.3 or more, and said base sheet having a heat-resistant slipping layer provided on the surface on which the heat transfer layer is not provided.A heat transferable sheet to be used in combination with the heat transfer sheet, comprising a receptive sheet having (a) a base sheet and (b) a receptive layer for receiving the dye migrated from the above-mentioned heat transfer sheet on heating, said receptive sheet having an intermediate layer provided between the base sheet and the receptive layer.

Abstract: A transfer ink film having one major surface containing sublimable dyes is passed through a path between the surface of a drum and a thermal head having a plurality of heating elements which are selectively energized in response to input image signal, while a record sheet is fed from a record-sheet feed part of a printing apparatus to said path so as to be superposed on the transfer ink film. As a result, the dyes are transferred by sublimation from the transfer ink film to the superposed record sheet. During the feed of the record sheet, any dust particles or the like attached to the surface of the sheet are removed by an adhesive roller, an electric discharge brush and so on whereby a high-quality image can be obtained on the record sheet. The record sheets are contained in the form of a stack in a sealed cassette which is detachably inserted into the record-sheet feed part of the printing apparatus.

Abstract: An image-forming agent selected from polyacids of molybdenum and tungsten and salts and complexes of these polyacids and disposed as a layer on at least one surface of a support substrate is reduced thereby being caused to undergo coloring in the form of an image and is then irradiated over its entire surface including thus colored parts and yet uncolored parts with long wavelength light rays which are absorbable by only the colored parts thereby to produce a colored image wherein the optical density of only the colored parts is selectively increased to a remarkable degree.