| 摘要 |
PURPOSE:To improve durability of a heating head by a method wherein driving time for a heating head in copy printing is made longer than in an ordinary printing and the head is kept in a constant temperature. CONSTITUTION:An input signal of COPY is sent to an AND gate 4. When a printing command signal ST arrives, a pit signal ''1'' is written to T1 step of a shift register 1 in synchronization with a clock pulse CP, the 1st flip-flop 2 is set and the output Q1 disappears when the pit signal reaches T4 step. At the same time, the 2nd flip-flop 3 is set and the output Q2 disappears 6mm sec after the pit signal reaches T12 step. A gate 4 is closed every time the CP arrives and the output Q3 of the gate 4 is equal to that which gives a pause period to the output Q1 at every given period. Accordingly there appears a head driving signal HT composed of a continuous period of 6mm sec after the HT arrives from the OR gate 5 and an intermittent period of 6mm sec continued after this continuous period, a constant voltage is supplied to the heating head for a corresponding while and a constant temperature is maintained. |
