| 摘要 |
<p>PURPOSE:To prevent dots of the LED array from shifting in position owing to heat expansion by detecting the temperature of an LED array that each recording unit has, controlling electric power supplied to a heater according to the temperature, and uniforming the temperature of each LED array. CONSTITUTION:Recording units A - N are each equipped with an LED array 1 provided with a heating means 3 and a temperature sensor 2. The temperature of each LED array 1 is detected by the temperature sensor 2 and compared by a temperature comparing means 5 with predetermined reference temperature to find the mutual temperature difference. This reference temperature is set a little bit higher than temperature in normal use so as to perform control only by heating. A heating control means 6 controls the quantity of heat supplied to the heating means 3 according to the temperature difference found by the comparing means to hold the temperature of the LED 1 of each recording unit at the reference temperature, thereby uniforming the length of each LED array due to its heat expansion. Consequently, the recording dots do not shift in relative position.</p> |
