| 摘要 |
PURPOSE:To prevent damage of the platen and display the cause of extinction, by detecting the temperature rise due to light source for image exposure, and cutting off power supply to the light source and displaying the cut-off, in an electronic copier. CONSTITUTION:When the temperature in the vicinity of the platen of a copying machine is raised by a halogen lamp 16 for image exposure and exceeds a specified value, it is detected, and a fuse 315 melts down, so that power supply to the lamp 16 is cut off. As a result, a voltage is applied to a photo coupler 316, and a transistor 317 is made to conduct to light up a light emitting diode 318, etc. Then, cut-off of power supply to the lamp 16 is display, and damage of the platen due to overheat may be prevented. In the event of failure of stabilizing circuit 324 of the lamp 16 and driver circuit 119, similarly, light emitting diodes 323, 321 are lit, and the cause of extinction of light source lamp due to cut-off of power source may be displayed. |
