Abstract: A web take-up roll including a cylindrical body and a web taken up around the cylindrical body. A terminal portion of the web is joined to the cylindrical body through a double-coated tacky tape including a paper substrate and adhesive layers formed on both sides of the substrate. The substrate is capable of ply separation by a force smaller than a force required to separate adhesive faces of the adhesive layers from either the terminal portion of the web or the cylindrical body.

Abstract: A thermal transfer image-receiving sheet is provided which is, in use, superimposed on a thermal transfer sheet and can form a printed, recorded image, having excellent storage stability, with a high density and a high resolution. The sheet includes a substrate and an intermediate layer and a receptive layer formed in that order on at least one surface of the substrate, wherein the intermediate layer contains a polyurethane resin having a specific glass transition temperature of 40.degree. C. or above.

Abstract: A medical image forming method including, the steps of superposing a three-primary-color thermal transfer sheet and an image receiving sheet, the thermal transfer sheet having a base film and three color dye layers of yellow, magenta, and cyan, each of the dye layer; being composed of a dye and a binder, the image receiving sheet having a dye accepting layer heating the rear surface of the thermal transfer sheet with a heating device in an image shape; and driving and controlling the heating device with a control unit so as to form a full color image on the image receiving sheet. The control unit is adapted to compensate tones of the image so that chromaticity values thereof formed on the image receiving sheet are in a region defined by four points of (a*=0, b*=0), (a*=20, b*=-5), (a*=18, b*=15), and (a*=0, b*=15) when an achromatic color signal is input and L*=80.

Abstract: This invention relates to a heat transfer sheet including a substrate film and a dye layer formed on the surface of the substrate film, the dye layer containing a dye and a binder resin and, if required, a release agent. The binder resin and/or release agent include a graft copolymer containing at least releasable segment selected from polysiloxane, carbon fluoride and long-chain alkyl segments grafted onto its major chain. According to this invention, there is provided a heat transfer sheet which enables an image of high density to be made at high speeds with neither adhesion between the dye layer and the dye-receiving layer nor peeling-off of the dye layer at the time of heat transfer and can produce an image on the surface of which a transparent film can be laminated.

Abstract: A medical image forming method including the steps of superposing a three-primary-color thermal transfer sheet and an image receiving sheet, the thermal transfer sheet having a base film and three color dye layers of yellow, magenta, and cyan, each of the dye layer being composed of a dye and a binder, the image receiving sheet having a dye accepting layer; heating the rear surface of the thermal transfer sheet with a heating device in an image shape; and driving and controlling the heating device with a control unit so as to form a full color image on the image receiving sheet. The control unit is adapted to compensate tones of the image so that chromaticity values thereof formed on the image receiving sheet are in a region defined by four points of (a*=0, b*=0), (a*=20, b*=-5), (a*=18, b*=15), and (a*=0, b*=15) when an achromatic color signal is input and L*=80.

Abstract: The present invention provides a heat transfer sheet including a substrate film and a dye and binder-containing dye layer formed thereon, characterized in that the substrate film includes a polyester film and an adhesive layer is formed between the substate film and the dye layer. The adhesive layer is stretched simultaneously with the substrate film, while the adhesive layer remains formed on the substrate film. Such an adhesive layer can be made very thin and is very effective in preventing the dye layer from peeling off. Thus, the invention makes it possible to provide a heat transfer sheet which can impart a high density to the image with an improved heat efficiency.