| 摘要 |
PURPOSE:To keep printing quality constant even when the recording is operated continuously for a long time by detecting the optical concentration of recording paper contacting the end of the substrate of a thermal head and controlling recording energy based on the detected signals. CONSTITUTION:The optical concentration of the balnk space of rocording paper 3 which contacted the end part of the substrate of a thermal heat 1 (a part where heating dots are not provided) is detected by a light source 4 and a detector 5. Signals from the detector are transferred to a control circuit (a), and the circuit controls a power source (b) and a driver (c) to adjust voltage, current, time, etc., applied to the thermal head appropriately so that optimum recordig energy may be obtained. |
