US Patent 7978992 Image forming apparatus executing stabilization process at proper frequency

In an MFP, when a count of printed sheets of paper exceeds a predetermined count, a controller reads, from internal counters, a frequency of a stabilization process executed in return, a frequency of a stabilization process executed automatically in printing, a frequency of a stabilization process executed manually based on a user's instruction, and a frequency of return, respectively. When the frequency of the stabilization process executed automatically is small while the frequency of the stabilization process executed manually is large, the controller raises a frequency level of execution of the stabilization process. When the frequency of the stabilization process executed manually is small, the controller lowers the frequency level of execution of the stabilization process.