| 摘要 |
<p>PURPOSE:To detect the temperature of a head accurately and with no time delay without using a temperature sensor by detecting the electric power consumed by at least one of the head and a power supply, and estimating the temperature of at least one of the head and the power supply on the basis of the power consumption. CONSTITUTION:A current-detecting means 23 outputs a voltage signal according to a supply current, and an electric charge according to the voltage signal is accumulated into a capacitor C1 through a resistor R1. The accumulation of the charge corresponds to heat accumulation in sn LED array head 3. When the voltage signal is not outputted from the detecting means 23, the charge accumulated in the capacitor C1 is consumed by the resistor R1. The consumption corresponds to release of heat from the head 3. Where a reference voltage Vref supplied to a plus (+) input terminal of a voltage comparator 24 is preliminarily set to an appropriate value, it is possible to turn ON a READY signal when the temperature of the head 3 is not higher than a predetermined temperature and to turn OFF the READY signal when the head temperature is above the predetermined temperature. With the READY signal turned OFF, supply of an output data signal from a host computer is stopped.</p> |
