| 摘要 |
PURPOSE:To achieve simpler protection of a thermal element, by a method wherein an abnormal state by an abnormal operation of a microcomputer or the like of a system control part is detected with a part controlling a driving circuit of a thermal head, and a recording enabling signal is forbidden to be outputted. CONSTITUTION:An AND circuit 6 takes an AND condition of designation signals B50-B57 of a recording block and an application time control signal S11 of one recording block, and outputs recording enabling signals B60-B67 to a thermal head driving circuit. Further, when an abnormal value larger than a specified maximum application time is set to an application time setting registor 11 of the one block recording, an AND circuit 13 of an abnormal detection circuit decodes it to output an abnormal detection signal S10, and resets a SR-FF 15 via an OR circuit 14. Thereby, the application time control signal S11 of the one recording block becomes zero, and the recording enabling signals B60-B67 of the AND circuit 6 are forbidden to be outputted. Recording is thus disabled automatically by the abnormal detection signal S10, and a thermal element of a thermal head is protected. |
