| 摘要 |
<p>PURPOSE:To prevent the breakage of a heat-sensitive recording head by overheating by using a system in which when the connection between a temperature detection element to detect the peripheral temperature of a heat-sensitive head and a drive control circuit is disconnected, the disconnection is detected and a protective circuit is actuated. CONSTITUTION:In case where no breaking of lead line and no disconnection of connectors occur, the output signal D of a comparator C1 is in low levels within a control temperature range. In this case, on the basis of comparison between the threshold voltages TH1-TH2 of a split resistor group AR and temperature signal THS from a heat sensor element RS, comparators C2 and C3 send out temperature information signals OS2 and OS3 to the drive control circuit 3. However, in case where the breaking of the lead line an disconnection of connectors occur, the output signal D of the comparator C1 becomes high levels and thereby the protective circuit 2 is actuated.</p> |
