Image formation apparatus that determines whether motor driving force is being transmitted to fixing unit

1. An image formation apparatus, comprising:

a fixing unit configured to heat a medium while moving the medium to fix a developer image on the medium;

a motor configured to provide the fixing unit with a driving force to be used to move the medium;

a controller configured to determine whether the driving force provided by the motor is being transmitted to the fixing unit;

a power supply configured to switch between a first mode in which electric power is supplied to the controller and a second mode in which no electric power or less electric power than that of the first mode is supplied to the controller; and

a sub-controller configured to be supplied with electric power from the power supply during the second mode and detect whether the fixing unit is detached,

wherein if the sub-controller detects a detachment of the fixing unit during the second mode, the controller determines whether the driving force provided by the motor is being transmitted to the fixing unit after the power supply is switched from the second mode to the first mode.

2. The image formation apparatus according to claim 1 , wherein the controller is configured to determine whether the driving force provided by the motor is being transmitted to the fixing unit when the fixing unit is attached.

3. The image formation apparatus according to claim 1 , wherein the controller is configured to determine whether the driving force provided by the motor is being transmitted to the fixing unit before performing a warming-up of the fixing unit and,

when the driving force provided by the motor is not being transmitted to the fixing unit, the controller does not perform the warming-up of the fixing unit.

4. The image formation apparatus according to claim 1 , wherein

the fixing unit includes:

a fixing roller and a fixing back-up roller which are configured to receive the driving force from the motor to rotate in predetermined directions, and to heat the medium while moving the medium: and

an adjustment mechanism configured to adjust a position of at least one of the fixing roller and fixing back-up roller when the fixing roller and the fixing back-up roller are rotated in directions reverse to the predetermined directions by using the driving force provided by the motor, and

the controller is configured to control the motor so that the fixing roller and the fixing back-up roller rotate in the reverse directions and to determine whether the driving force provided by the motor is being transmitted to the fixing unit based on whether the adjustment by the adjustment mechanism is successful.

5. The image formation apparatus according to claim 4 , wherein the adjustment mechanism is configured to move the fixing back-up roller to a previously determined position when the fixing roller and fixing back-up roller are rotated in the reverse directions.

6. The image formation apparatus according to claim 5 , further comprising:

a position detection sensor configured to detect whether the fixing back-up roller is moved to the previously determined position, wherein

the controller determines based on a detection signal from the position detection sensor whether the driving force provided by the motor is being transmitted to the fixing unit.