| 摘要 |
PURPOSE:To prevent a form from turning yellow without varying the heat capacity of a heating plate by powering off a heater for a specific time forcibly when a printing form has stopped during heating and restarting power supply when the form has started running. CONSTITUTION:Heat generated by the heater 3 is supplied to the printing form 1 through the heating plate 2. A temperature detecting element 4 is fitted to the reverse surface of the heating plate 2 to detect the temperature of the heating plate 2 and connected to a heater driving circuit 7 through a temperature controller 6 and an AND gate 16. A paper feed signal B for the form 1 is inputted to the reset terminal of a counter 9 and differentiators 11 and 12. Once the form 1 has stopped running, the differentiator 12 resets an FF14 and the gate 16 is held closed until the FF14 is set by the counter 9 and a differentiator 10 some set time later; and no signal is inputted to the circuit 7 even when the detected temperature of the element 4 is lower than control temperature, and the heater 3 is powered off. When the run of the form 1 has been restarted within the set time of the counter 9, the FF14 is set to restart powering on the heater 3 in response to a signal H from the controller 6. |
