1. Field of the Invention
The present invention relates generally to a printer for saving a recording picture, such as a video picture or the like, as a hard copy, and particularly to a sublimation type thermal transfer system video printer for producing a hard copy of a video picture.
2. Description of the Related Art
Conventional video printers include a gear mechanism for searching a head of an ink ribbon of a ribbon cassette housed in the printer and taking up the ink ribbon by a take-up reel during a printing operation using a DC motor as a drive source. These printers typically include a gear mechanism for feeding a printing paper housed in a tray, and a cam mechanism for pressing the ink ribbon on the printing paper and moving a printing head, which subjects the printing paper to a printing processing. A DC motor is provided for moving the printing head and for use as a drive source to rotate a capstan for carrying the printing paper to a printing position and a paper delivering position successively. A complex cam mechanism and a link mechanism are required to drive the paper feeding mechanism, the cam mechanism and the printing head with a single drive motor. Other printer devices include a stepping motor as a second drive source for driving one or more of the printer mechanisms.
These conventional printers suffer from a linkage and drive mechanism which is complex and space consuming and fails to provide effective operation in the event of paper jams or other interruptions during normal printing operations. Thus, one object of the present invention is to provide a printer construction whereby miniaturization of the printer can be realized and printer operations can be enhanced under adverse conditions.
Another problem with conventional video printers is that they waste printer ribbon between successive printing operations. Conventional printers typically include a mechanism for holding a printing paper and an ink ribbon between a printing head and a platen and use a stepping motor as a drive source and a cam mechanism for pressing and heating the ink ribbon on the printing paper for printing processing. When the ink ribbon is released from the printing paper, it has a slack between the supply reel and the take-up reel of the ribbon cassette. This slack is typically removed by winding the ribbon in the direction of winding during the printing operation, thereby increasing the amount of ribbon required for printing. In addition, identification systems on ribbon cassettes often require rotation of the take-up and/or supply reels resulting in further waste of the ink ribbon. Accordingly, it is a further object of the present invention to eliminate wasteful usage of ink ribbon in printer devices.
Yet another problem with conventional video printers is that the printer head moving mechanism is typically interconnected with the paper moving mechanism or the ribbon identification mechanism such that the printing head cannot be moved independent of those mechanisms. This results in unnecessary movement of the printing head during paper feeding and ribbon identification, and restricts the use of the printing head for guiding the printing paper into a printing position. Thus, a further object of the present invention is to provide a driving mechanism for a printer which allows the printing head to be freely moved while maintaining a compact printer arrangement.