Power off sequence of image forming apparatus

An image forming apparatus comprising:

• a storage unit that stores information;
• a first control unit that controls at least the storage unit;
• a first power source unit that supplies power to the first control unit;
• an image forming unit provided with a plurality of loads for forming an image;
• a second control unit that controls the image forming unit;
• a second power source unit that supplies power to the storage unit and the image forming unit;
• a switch unit configured to notify the first control unit and the second control unit of a shutdown instruction to shut down the image forming apparatus through an operation by an operator;
• a delay unit that outputs an off-signal after a first predetermined time elapses from receipt of the shutdown instruction by the switch unit;
• an off-signal transfer unit that, upon receiving an input of either an off-signal output from the first control unit or the off-signal output from the delay unit in response to the shutdown instruction by the switch unit, transfers the off-signal to the first power source unit;
• a first relay unit that switches between supplying alternating current power to the first power source unit and stopping the supply of alternating current power to the first power source unit, the first relay unit supplying alternating current power to the first power source unit when a first power supply instruction signal is input from the first power source unit, and stopping the supply of alternating current power to the first power source unit when the off-signal is input from the off-signal transfer unit to the first power source unit and thereby the first power source unit stops transmitting the first power supply instruction signal;
• and
• a second relay unit that supplies alternating current power to the second power source unit when a second power supply instruction signal is input from the first control unit, and stops the supply of alternating current power to the second power source unit when the second power supply instruction signal is no longer input from the first control unit,
• wherein the second control unit stops the supply of power from the second power source unit to the storage unit and the image forming unit if the second control unit receives a shutdown instruction from the first control unit after input of the shutdown instruction from the switch unit or if a second predetermined time elapses from input of the shutdown instruction from the switch unit.

An image forming apparatus comprising:

• a first control unit that controls the image forming apparatus;
• a first power source unit that supplies power to the first control unit;
• an image forming unit configured to form an image;
• a second control unit that controls the image forming unit based on an instruction from the first control unit;
• a second power source unit that supplies power to the image forming unit;
• a power switch that is operated manually, the power switch transmitting status signals indicating a state of the power switch to the first control unit and the second control unit,
• wherein the first control unit transmits a termination instruction to the second control unit and stops the supply of power from the first power source unit and the second power source unit after receiving a status signal indicating that the power switch has been turned off, and
• wherein the second control unit terminates the operation of the image forming unit upon receiving the termination instruction from the first control unit, and
• the second control unit stops the supply of power from the second power source unit after receiving the status signal indicating that the power switch has been turned off even if the first control unit does not stop the supply of power from the second power source unit.