Patent ID: 8099613

Claim:
An image forming apparatus having a first mode for performing an image forming process and a second mode with power consumption lower than that of the first mode, comprising: a detection unit that includes a plurality of error detection units and configured to detect presence and absence of an error of the image forming apparatus; a main control unit configured to switch to the second mode in response to the error being detected in the first mode, and to return to the first mode in response to the error being removed in the second mode, wherein the main control unit is further configured to select a timing for switching from the first mode to the second mode, from at least two different timings, based on content of the error; a power source circuit configured to generate power for the first mode and the second mode, and to supply the power for operation of the image forming apparatus; and a power source control unit configured to supply power to a first circuit portion including an image forming unit and the detection unit in the first mode, and to stop power supply to the image forming unit and to supply power to a second circuit portion including at least the detection unit in the second mode.