| 摘要 |
PURPOSE:To prevent the temperature of original glass from rising more efficiently by measuring previously variation in the temperature of the original glass from the level of the quantity of exposure and an exposure time and estimating the temperature of the original glass. CONSTITUTION:The temperature T of the original glass is not detected by using a sensor and variation in the temperature T with time is estimated from the quantity of lamp light (exposure level) to control operation. When the copying operation is in process, the rising temperature is estimated and when not, cooling temperature is estimated; when a timer which indicates the time of temperature estimation counts up to a specific value, it is decided whether or not the original glass temperature T is lower than a temperature level T1. Then it is decided whether or not the original glass temperature T is lower than a temperature level T2 and the cooling temperature is estimated; and then it is decided whether or not T is lower than T0 and if so, a cooling fan is stopped, thereby making a return. The temperature rises during the copying operation owing to exposure, so a temperature increment corresponding to each mode and each exposure level is added to the timer at constant intervals of time, thus estimating the temperature rise. |
