An image forming device includes a pickup roller, a planetary gear mechanism having an input gear, trigger and an output gear, lift mechanism, a cam member, a change-over member, and a stop assembly. The change-over member includes a first arm movable between a first position engaging with the trigger for transmitting rotation of the input gear to the output gear and a second position disengaging from the trigger for stopping transmission of rotation from the input gear to the output gear. The second arm is contactable with the cam member for moving the first arm between the first and second positions with movement of the pickup roller. The stop assembly includes a third arm movable between a third position engageable with and a fourth position disengageable from the output gear, and a fourth arm contactable with the cam member for moving the third arm between the third and fourth positions.