| 摘要 |
PURPOSE:To normally actuate automatic exposure and to obtain an image with stable image density in forming the image with automatic exposure by specifying the control of the application of a current to a fixing heater so that the great change of voltage does not occur in preliminary exposure. CONSTITUTION:The titled device installs a heater control means for controlling the temperature of a fixing roller 44 by controlling the application of the current to the fixing heater 45 and a heater control specification means for specifying the control by a fixing heater control means in the midst of sampling the data of original density with preliminary exposure. Since the control of the application of the current to the fixing heater 45 is specified so as not to cause the great change of voltage in the preliminary exposure, automatic exposure is always executed normally and the image density is not influenced. Also there is no possibility that the temperature of a fixing device is drastically changed from a control level to cause a fault in fixing because the control of the application of the current to the fixing heater 45 is specified only in a comparatively short time in the preliminary exposure. Thus, an image forming device in which the image is not influenced and the fault in fixing is not caused can be obtained. |
