| 摘要 |
<p>PURPOSE:To prevent an erroneous action from occurring at the time of data input in a split block-type thermal head drive circuit which performs serial data input and head drive simultaneously. CONSTITUTION:Serial data 42 is sequentially entered into a shift register 10 in synchronization with a clock signal 43, and thereby is converted to parallel data for output. This parallel output drives a transistor group 16, so that an unillustrated thermal resistor connected to terminals DO1, DO2 is selectively energized to generate heat. So many pieces of the thermal head drive IC 34 of said constitution are used and divided into two blocks, one of which performs printing and the other of which enters print data. Thus these blocks are alternately changed to perform the parallel actions, one of which is to print data and the other of which is to enter data, simultaneously. In this case, a delay circuit 38 which delays a clock signal 43 by specified time is provided to inhibit data input only for a specified time (instable head voltage period) in the early stage of the drive period for thermal resistor elements in each block.</p> |
