Automatic document feeder, image reading device having the same and image forming apparatus having the same

An automatic document feeder, comprising:

• a pickup roller to pick up a document sheet;
• a supporting member to support the pickup roller;
• a rotating shaft to rotatably support the supporting member;
• a lifting lever to lift the pickup roller by rotating the supporting member;
• a pickup motor to drive the pickup roller and the lifting lever;
• a first power transmission path to transmit power from the pickup motor to the pickup roller;
• and
• a second power transmission path branched from the first power transmission path to receive power from the first power transmission path and to transmit power from the pickup motor to the lifting lever.

An image reading device, comprising:

• a reading device body including a document supply tray and a document feeding path;
• a reading unit to read image information from a document sheet in the document feeding path;
• a pickup device including a pickup roller to pick up a document sheet from the document supply tray and feed the document sheet to the document feeding path;
• a lifting device to move the pickup device between a standby position and a pickup position;
• a pickup motor configured to be driven in clockwise and counterclockwise directions to drive the pickup roller and the lifting device;
• a first power transmission unit to transmit power from the pickup motor to the pickup roller;
• and
• a second power transmission unit to transmit power from the pickup motor to the lifting device.

An image forming apparatus, comprising:

• an image reading device including a reading unit to read image information from a document sheet and an automatic document feeder to pick up a document sheet and feed the document sheet to the reading unit, the automatic document feeder including:
• a pickup device including a rotating shaft, a supporting member rotatably mounted on the rotating shaft, and a pickup roller supported by the supporting member,
• a lifting lever to move the supporting member between a standby position and a pickup position, and
• a pickup motor to drive the pickup roller by rotating in a first direction and to drive the lifting lever by rotating in a second direction;
• and
• a printing device to print an image on a printing medium.

An image reading device, comprising:

• a reading unit to read information of a document sheet;
• a pickup device including a pickup roller to feed the document sheet to the reading unit when the pickup device is in a pickup position;
• a lifting device to move the pickup device between the pickup position and a standby position;
• and
• a pickup driving device to drive the pickup roller by rotating in a first direction and to drive the lifting device by rotating in a second direction.

An image forming apparatus, comprising:

• an image reading device including:
• a reading unit to read information of a document sheet,
• a pickup device including a pickup roller to feed the document sheet to the reading unit when the pickup device is in a pickup position,
• a lifting device to move the pickup device between the pickup position and a standby position, and
• a pickup driving device to drive the pickup roller by rotating in a first direction and to drive the lifting device by rotating in a second direction;
• and
• a printing device to print an image on a printing medium.