| 摘要 |
PURPOSE: To accelerate a first copy speed and to reduce power consumption of a heat insulating heater by executing heat insulation to keep a fluorescent tube temp. to the temp. capable of obtaining an absolutely minimum light quantity when a copying machine stands by. CONSTITUTION: To a CPU 30, a lamp lighting control circuit 32 lighting the fluorescent tube 21 is connected, and a light quantity sensor 26 is connected through a light quantity detection circuit 31. Further, to the CPU 30, a heater control circuit 34 allowing a heat insulating heater 24 to generate heat is connected, and a temp. sensor 25 is connected through a temp. detection circuit 33. The temp. of the heat insulating heater 24 is detected by the temp. sensor 25, and a tube wall temp. is controlled from the temp. nearby the fluorescent tube 21 by controlling a calorific value. Then, when the copying machine is in standby state, the fluorescent tube 21 is kept at the temp. capable of obtaining the absolutely minimum light quantity b the heater control circuit 34. Thus, a time required for raising the fluorescent temp. up to the temp. (optimum tube wall temp.) capable of obtaining the maximum light emitting efficiency is saved at a copying time. |
