Patent ID: 9535379
Date: 2017-01-03
CPC Classifications: G03G

Claim:
1. An image forming apparatus, to which an option device is connectable, for forming a toner image on a recording material, the image forming apparatus comprising: an image forming unit configured to form an unfixed toner image on the recording material; a fixing unit, including a heater, configured to fix the unfixed toner image on the recording material; a temperature detection unit configured to detect a temperature of the fixing unit; a power control unit configured to control power to be supplied to the heater so that a detected temperature by the temperature detection unit becomes a target temperature for enabling fixing the unfixed toner image, and to set a maximum power suppliable to the heater according to a total power to be supplied to the image forming apparatus; a conveyance unit configured to convey the recording material to the fixing unit; and a conveyance control unit configured to control the conveyance unit; a connection detecting unit configured to detect a connection status of the option device to the apparatus; and a comparison unit configured to compare the maximum power and a threshold power to find which is greater, the comparison unit setting a different value to the threshold power according to the connection status detected by the connection detecting unit, wherein in a case where the comparison unit finds that the maximum power is greater than the threshold power in a warm-up period of the fixing unit, the conveyance control unit controls the conveyance unit such that the conveyance unit conveys the recording material to the fixing unit, according to a time that has elapsed from a start of supplying power to the heater.