Patent attributes
The present invention provides a fixing device and a digital photocopier which can shorten the time from an instruction of starting image formation to end of fixing. The fixing device is provided in a cylinder made of metal and having a small thickness, and includes a magnetic excitation coil. When the power source is turned on, all the electric power defined by subtracting an electric power amount consumed by components other than the fixing device is supplied to the magnetic excitation coil to perform heating. As the structural components of the photocopier and auxiliary devices added to the photocopier operate, the electric power defined by subtracting, from the maximum input electric power, the electric power consumed by the structural components of the photocopier and the auxiliary devices is supplied to perform heating. In this manner, the heat roller of the fixing device is heated, in a short time, to a temperature which enables fixing, so that the time required for first copying can be shortened.