1. Field of the Invention
The present disclosure relates to an ink sheet cartridge, and more particularly, to an ink sheet cartridge used in a line thermal printer for printing a print image.
2. Description of the Related Art
In general, a line thermal printer having a longitudinal thermal head, and heater elements of which are arranged in a width direction of a printing paper, is used as a printer which promptly performs a printing operation line-by-line or page-by-page on a printing paper.
An ink sheet cartridge which receives an ink sheet unit in a cartridge case is fitted into the line thermal printer as an ink sheet cartridge for the line thermal printer.
The ink sheet cartridge includes a longitudinal ink sheet of which a coloring region is continuously applied with ink of colors yellow, magenta, cyan, or the like. One end of the ink sheet is wound around a sheet supply bobbin of a cylindrical shape while the other end of the ink sheet is wound around a winding bobbin of a cylindrical shape. In addition, the cartridge case includes upper and lower halves made of a synthetic resin, which are bonded or engaged with each other by an ultrasonic welding or a snap-in method.
A known ink sheet cartridge allows the ink sheet unit to receive the sheet supply and winding bobbins to be rotatable in the cartridge case.
However, in an ink sheet cartridge formed by bonding the upper and lower halves with each other so as to form the cartridge case, it is difficult to reuse the cartridge case as the cartridge case needs, inevitably, to be broken to replace a used ink sheet unit with an unused ink sheet unit. Likewise, in an ink sheet cartridge formed by engaging the upper and lower halves with each other in terms of the snap-in method, it is difficult for a common user to reuse the cartridge case as a tool for detaching the engaged halves by the snap-in method, or a certain degree of skill, is necessary to replace the ink sheet unit.
Additionally, in the ink sheet unit of the known ink sheet cartridge, the coloring region applied with the ink of yellow, magenta, cyan, or the like color is exposed. Because of this, even when it is possible to detach the upper and lower halves to replace the ink sheet unit, there is a concern of touching a wound part of the ink sheet in the sheet supply bobbin or the sheet winding bobbin with a hand or finger, etc., so that a foreign substance such as dust can be attached to, or a flaw created on, the coloring region of the ink sheet. Therefore, when an image is printed by using the above-mentioned ink sheet, a failure or glitch in the transfer of the ink results in an unsatisfactory image print.
Examples of such an ink sheet cartridge are disclosed in Japanese Patent No. 3496267 and Japanese Unexamined Patent Application Publication No. 5-155122.