1.  Field of the Invention
The present invention relates to a thermal transfer recording system. 
2.  Description of the Prior Art
An extensive study has been made on a methods for reproducing an image in a form of a hard copy such as a photograph from an electrical image signal derived from a video camera, a still camera, television, video disk or a facsimile machine.  One of the important methods is a thermal transfer recording method. 
In the thermal transfer recording method, a thermo-sensing recording paper is applied to a thermal head having a group of heat generating dots arranged at 4-10 dots/mm and a two-dimensional image is printed on the recording paper based on an image signal sent to the thermal head one line at a time.  The thermo-sensitive record paper may be a thermosensitive coloring paper or a composite sheet of an image forming sheet and an ink sheet. 
The recorder of this method usually includes a thermal head having a group of heat generating dots arranged one-dimensionally and a group of electrode pairs for energizing the dots, a platen for urging the composite sheet of the image forming sheet and the ink sheet to the thermal head, an image forming sheet supply unit, an image forming sheet feed roller, an ink sheet supply unit, a take-up roller for taking up the used ink sheet, motors for driving the rollers and an electrical circuit. 
In the prior art machine, the ink sheet supply unit and the image forming sheet supply unit are separately provided.  Thus, when the sheets accommodated therein have been exhausted and the unit is to be replaced by a new one, such replacement must be done at two locations.  The replacement work is troublesome because the hands of an operator may be contaminated or the ink sheets may be contaminated.  It is hard for the operator to conduct such replacement at two locations.