Paper feeding device for printer

A printer, comprising:

• a printer body;
• a paper feeding cassette to load a plurality of paper sheets;
• a driving power source;
• a driving gear having a rotation shaft and driven by the driving power source;
• a passive gear having a rotation shaft and rotated interlockingly with the driving gear;
• a first link having a first end pivotally installed on the rotation shaft of the driving gear, and a second end coupled to the rotation shaft of the passive gear;
• a pickup gear rotated interlockingly with the passive gear;
• a second link having a first end rotatably installed on the rotation shaft of the passive gear, and a second end coupled to a rotation shaft of the pickup gear;
• a pickup roller having a rotation shaft and coaxially coupled to the pickup gear, to simultaneously rotate and press the paper sheets to feed the paper sheets one by one into the printer body;
• and
• a supporting arm having a first end coupled to the rotation shaft of the pickup roller, and a second end pivotally installed on a side of the printer body.

A paper feeding device for a printer, comprising:

• a first gear having a rotation shaft to rotate in response to a driving torque;
• a second gear having a rotation shaft to receive the driving torque from the first gear;
• a first link, comprising:
• a first end connected to the rotation shaft of the first gear, and
• a second end connected to the rotation shaft of the second gear;
• a third gear having a rotation shaft to receive the driving torque from the second gear;
• a second link, comprising:
• a first end connected to the rotation shaft of the second gear, and
• a second end connected to the rotation shaft of the third gear;
• a paper unit to contain a plurality of paper sheets;
• and
• a roller, having a rotation shaft, connected to the third gear, to rotate and press the paper sheets to feed the paper sheets one by one into a printer body of the printer.

A printer, comprising:

• a printer body;
• a first gear having a rotation shaft to rotate in response to a driving torque;
• a second gear having a rotation shaft to receive the driving torque from the first gear;
• a first link, comprising:
• a first end connected to the rotation shaft of the first gear, and
• a second end connected to the rotation shaft of the second gear;
• a third gear having a rotation shaft to receive the driving torque from the second gear;
• a second link, comprising:
• a first end connected to the rotation shaft of the second gear, and
• a second end connected to the rotation shaft of the third gear;
• a paper unit to contain a plurality of paper sheets;
• and
• a roller connected to the third gear, to rotate and press the paper sheets to feed the paper sheets one by one into the printer body.

A printer, comprising:

• a printer body;
• a first link;
• a second link pivotally connected to the first link;
• a paper unit to contain a plurality of paper sheets;
• a wall installed on an end of the paper unit, to contact the paper sheets;
• a roller to rotate and press the paper sheets to feed the paper sheets one by one into the printer body;
• and
• an arm, pivotally connected to the roller,
• Fpick>Ffric>Fd>Fdouble being satisfied throughout a printing operation, wherein Fpick is a feeding force due to a torque of the roller, Ffric is a carrying force due to a friction between the roller and the paper sheets, Fd is a resistant force acting on a leading edge of the paper sheets by the wall, and Fdouble is a carrying force of a second paper sheet below an uppermost paper sheet.

A paper feeding device for a printer, comprising:

• a first rotation unit having a rotation shaft to rotate in response to a driving torque;
• a second rotation unit having a rotation shaft to receive the driving torque from the first rotation unit;
• a first link, comprising:
• a first end connected to the rotation shaft of the first rotation unit, and
• a second end connected to the rotation shaft of the second rotation unit;
• a third rotation unit having a rotation shaft to receive the driving torque from the second rotation unit;
• a second link, comprising:
• a first end connected to the rotation shaft of the second rotation unit, and
• a second end connected to the rotation shaft of the third rotation unit;
• a paper unit to contain a plurality of paper sheets;
• and
• a roller connected to the third rotation unit, to rotate and press the paper sheets to feed the paper sheets one by one into a printer body of the printer.