| 摘要 |
PURPOSE:To preheat a thermal printer with good efficiency and to miniaturize the device by a method in which the inside of a rotary roller is made of a conductive material, the outside is made of a magnetic material, the periphery of the roller is made of an elastic member, and a magnetic body to be applied AC magnetic field is provided in the inside hollow part. CONSTITUTION:A rotary platen 1 is provided with a conductive annular part (metal roller) 2 whose outside is overlapped with a magnetic roller 3 and then with an elastic member 4, rotatably supported by a supporter 8, and a magnetic body 5 fixed to the supporter inside. The magnetic poles 6 are arranged in the face of a transfer head. When applying AC magnetic field to the magnetic body 5 by a wiring 7, heat is produced in the section facing the magnetic poles 6 of the metal roller 2 due to the variation in magnetic flux between the magnetic poles 6, and by the heat, the transfer medium is preheated in the place where the transfer paper and transfer head are present through the magnetic roller and the elastic member 4. |
