Transmission mechanism and image forming apparatus employing the same

An image forming apparatus, comprising:

• an image forming unit configured to form images on a printing sheet;
• and
• a transmission mechanism configured to transmit a driving force to the image forming unit,
• the transmission mechanism including:
• an input gear configured to receive a driving force of a forward direction and a driving force of a reverse direction;
• a first intermediate gear configured to engage with the input gear to rotate, a rotation shaft of the first intermediate gear being movable between a first position and a second position;
• a supporting member having an elongated hole which slidably receives the rotation shaft of the first intermediate gear;
• a first output gear configured to engage with the first intermediate gear to rotate when the rotation shaft is located at the first position;
• and
• a second output gear configured to engage with the first intermediate gear to rotate when the rotation shaft is located at the second position,
• wherein the rotation shaft can be located at a third position which is an intermediate position between the first position and the second position, the first intermediate gear engaging with both the first output gear and the second output gear when the rotation shaft is located at the third position.