| 摘要 |
PURPOSE:To inform the trouble of a device by disabling the titled copying circuit itself and turning off an external display when a lamp is disconnected and copying operation is disabled. CONSTITUTION:In normal copying state, electric power is supplied from a power source 9 to a data output device 15 through a lamp 1 and a diode 13. At the copying time, a transistor (TR) 12 is turned on, the potential of a connection point (a) between the lamp 1 and the diode 13 is reduced and the lamp 1 is turned on. On the other hand, power is supplied from a capacitor 14 to the data output device 15 to keep its power supply. The reverse current preventing diode 13 prevents current from flowing from the capacitor 14 to the TR12. If a filament of the lamp 1 is disconnected, power supply from the power source 9 is interrupted, so that the data output device 15 is disabled at the time when charge accumulated in the capacitor 14 is completely discharged, and the display of the external display element 8 is turned off. |
