Image forming apparatus with an open-close regulation mechanism of the automatic document feeder

An image forming apparatus comprising:

• an image forming unit that forms an image on a recording sheet;
• an image reading unit provided above the image forming unit so as to open and close with respect to the image forming unit;
• an automatic document feeder provided above the image reading unit so as to open and close with respect to the image reading unit;
• and
• an open-close regulation mechanism that regulates opening and closing movements of the automatic document feeder so that
• when the image reading unit is closed with respect to the image forming unit, the automatic document feeder is capable of opening with respect to the image reading unit, and
• when the image reading unit is opened with respect to the image forming unit, the automatic document feeder is prevented to open with respect to the image reading unit,
• wherein the open-close regulation mechanism includes a lock mechanism that includes:
• a hook;
• a lock lever that engages with the hook;
• a spring that elastically urges the lock lever toward the hook;
• a contact member provided monolithically with the lock lever;
• a lever rotatable support member that rotatably supports the lock lever and the contact member;
• and
• an arm that rotates in conjunction with the opening and closing movements of the image reading unit, the arm being provided between the image forming unit and the image reading unit,
• wherein when the image reading unit is closed with respect to the image forming unit, the contact member remains in contact with the arm and the lock lever remains separated from the hook against an elasticity of the spring to thereby automatically disengage the image reading unit and the automatic document feeder, and
• wherein when the image reading unit is opened with respect to the image forming unit, the contact member is separated from the arm and the lock lever engages with the hook by the elasticity of the spring to thereby automatically engage the image reading unit and the automatic document feeder.