Thermal recording apparatus

摘要

The thermal recording apparatus of the present invention includes a plurality of thermal resistive elements placed in a line, a plurality of drive circuits connected to the thermal resistive elements to drive the thermal resistive elements and a plurality of latch circuits connected to the drive circuits to supply recording signals in order to the drive circuits. A first memory receives and stores incoming recording signals formed by a series of 1 and 0 signals. These recording signals are supplied to the latch circuits. A second memory stores previously received recording signals which are output from the first memory. A comparator then compares the incoming recording signals with the previously received recording signals after the first memory supplies the incoming recording signals to the latch circuits. The comparator generates modified recording signals. The modified recording signals include 0 signals which are generated when 1 signals in the incoming recording signals follow 1 signals in the previously received recording signals. These modified recording signals are supplied to the latch circuits after the incoming recording signals are supplied to the drive circuits. Thus, if successive 1 signals occur in the same bits of the recording signals, the latch circuits and drive circuits do not receive successive 1 signals so the thermal resistive elements are not continuously driven. By using such a modified recording signal to drive the thermal resistive elements for part of the time period, burn out of the thermal resistive elements can be prevented.