| 摘要 |
<p>A thermal printhead (19), which is pivotally mounted on a carrier (11), is moved into and out of its printing position by a four bar linkage (33, 34, 38, 11), which is responsive to the direction in which the carrier (11) is being advanced, rendering a spring (40), which urges the thermal printhead (19) into its printing position, effective and ineffective. When the carrier (11), is advanced from left to right to print, the linkage responds to a drive mechanism (23, 24) for the carrier (11) to enable movement of the printhead into its printing position by the spring (40) prior to the carrier drive mechanism (23, 24) moving the carrier. When the carrier (11) is to be moved from right to left in the non-printing direction, the linkage responds to the initial motion of the carrier drive mechanism (23, 24) in this direction to render the spring (40) ineffective and to move the printhead (19) out of its printing position prior to the carrier drive mechanism (23, 24) moving the carrier (11).</p> |
