| 摘要 |
PURPOSE:To miniaturize an image former by providing a coil spring between the first presser to be coupled with the axial periphery of a thermal head drive shaft and the second presser fixed to the drive shaft. CONSTITUTION:When a thermal head is separated from a platen, an aperture (delta1) is present only on one side between the projection 128 of the first presser 123 and the groove 127 of a drive shaft 126. The length of the coil spring 132 becomes l1-natural length. When a motor 83 is driven and the drive shaft 126 is turned to the direction of arrow X, the first presser 123 is turned through the second presser 129 and the spring 132 and the thermal head is driven toward the direction of platen through a rod 75. The second presser 129 is further turned and the spring 132 is extended to a length (l2)<(l1). An aperture (delta2) is formed in the opposite direction of the aperture (delta1), and the thermal head is pressingly contacted with the platen. The coil spring can thus be made smaller to permit the miniaturization of the device. |
