1. Technical Field
The present invention relates to an image forming apparatus.
2. Related Art
An image forming apparatus has heretofore the following configuration. That is, a toner image in accordance with image information is formed on an image retainer, and the toner image formed on the image retainer is transferred directly onto a recording sheet and fixed by a fixing unit. Alternatively, a toner image formed on an image retainer is once primarily transferred onto an intermediate transferor, then secondarily transferred onto a recording sheet from the intermediate transferor, and fixed by a fixing unit. Thus, a monochrome or full-color image is formed.
Toner used in the image forming apparatus on that occasion is typically provided by a manufacturer of the image forming apparatus. However, the toner may be provided by a maker other than the manufacturer of the image forming apparatus. In this case, when an unfixed toner image transferred onto a recording sheet is fixed by the fixing unit, the fixability of the toner may be different from fixability set originally in the image forming apparatus, so that a desired quality of fixation cannot be always obtained.