Feed cassette and image forming apparatus including the same

Abstract

A feed cassette including a frame, a knock-up plate hinge-coupled to the frame at a first end of the plate, to tilt about the first end according to an amount of paper stacked thereon, an overlap supply preventing part provided in front of a second end of the knock-up plate, the second end being opposite the first end, and to have a frictional surface forming a predetermined intermediate angle with respect to the knock-up plate and to prevent the paper supplied from the knock-up plate from being overlappingly supplied, a tilting arm having a hinge part provided on the frame, and a main body part to support the overlap supply preventing part, to have a leaning surface contacting an edge of the knock-up plate, and to tilt about the hinge part so that the leaning surface is slidably pressurized according to a tilting of the knock-up plate such that an intermediate angle between the frictional surface of the overlap supply preventing part and the knock-up plate remains within a predetermined angle range, and an elastic supporter having both sides thereof respectively coupled to the frame and the tilting arm so as to allow the leaning surface to remain in contact with the knock-up plate during the tilting thereof.

1 . A feed cassette, comprising: 
 a frame;    a knock-up plate hinge-coupled to the frame at a first end of the knock-up plate, to tilt about the first end according to an amount of paper stacked thereon;    an overlap supply preventing part, provided in front of a second end of the knock-up plate, the second end being opposite the first end, having a frictional surface forming a predetermined intermediate angle with respect to the knock-up plate to prevent the paper supplied from the knock-up plate from being overlappingly supplied;    a tilting arm having a hinge part provided on the frame, and a main body part to support the overlap supply preventing part, to have a leaning surface contacting an edge of the knock-up plate, and to tilt about the hinge part so that the leaning surface is slidably pressurized according to a tilting of the knock-up plate such that an intermediate angle between the frictional surface of the overlap supply preventing part and the knock-up plate remains within a predetermined angle range; and    an elastic supporter having both sides thereof respectively coupled to the frame and the tilting arm so as to allow the leaning surface to remain in contact with the knock-up plate during the tilting thereof.    
   
   
       2 . The feed cassette of  claim 1 , wherein the pressurization of the leaning surface causes the tilting arm to tilt in proportion to the tilting of the knock-up plate.  
   
   
       3 . The feed cassette of  claim 2 , wherein the leaning surface comprises a curved surface.  
   
   
       4 . The feed cassette of  claim 2 , wherein the leaning surface comprises a flat surface.  
   
   
       5 . The feed cassette of  claim 1 , wherein the overlap supply preventing part and the tilting arm are integrally formed with each other.  
   
   
       6 . An image forming apparatus, comprising: 
 a frame;    a knock-up plate hinge-coupled to the frame at a first end of the knock-up plate, to tilt about the first end according to an amount of paper stacked thereon;    a feed roller provided proximate to a second end of the knock-up plate, the second end being opposite the first end, to supply a paper from an uppermost stacking position of the knock-up plate;    a tilting arm part, having a frictional surface, to contact with the supplied paper and to make a predetermined angel with the knock-up plate so as to prevent the paper from being overlappingly supplied, and to maintain an intermediate angle between the frictional surface and the knock-up plate to be within a predetermined angle range as a result of the tilting arm part being hinge-coupled to the frame and being tilted due to contact and pressure of the knock-up plate; and    an elastic supporter having both sides thereof respectively coupled to the frame and the tilting arm part so as to cause the tilting arm part to remain in contact with the knock-up plate.    
   
   
       7 . The image forming apparatus of  claim 6 , wherein the tilting arm part comprises: 
 an overlap supply preventing part to which the frictional surface is attached;    a hinge part hinge-coupled with the frame; and    a main body to support the overlap supply preventing part and to tilt about the hinge part by the contact and pressure of the knock-up plate.    
   
   
       8 . The image forming apparatus of  claim 7 , wherein the main body part comprises a leaning surface to slidably contact the knock-up plate.  
   
   
       9 . The image forming apparatus of  claim 8 , wherein the leaning surface makes the tilting arm tilt in proportion to the tilting of the knock-up plate.  
   
   
       10 . The image forming apparatus of  claim 9 , wherein the leaning surface comprises a curved surface.  
   
   
       11 . The image forming apparatus of  claim 10 , wherein the leaning surface comprises a flat surface.  
   
   
       12 . A feed cassette, including a frame and a plate hinge-coupled to the frame at a first end of the plate to tilt about the first end according to an amount of paper stacked thereon, the cassette comprising: 
 an overlap preventing part including a frictional surface at a predetermined angle with respect to the plate provided in front of a second end of the plate, the second end being opposite the first end, so as to prevent the paper supplied from the plate from being overlappingly supplied from the cassette;    a tilting arm, including a leaning surface, elastically and hingeably provided on the frame to support the overlap preventing part and to contact an edge of the plate, the leaning surface being pressurized according to the tilting of the plate due to the contact between the leaning surface and the plate such that an angle between the frictional surface and the plate is within a predetermined range.    
   
   
       13 . An image forming apparatus having the feed cassette according to  claim 12  attached thereto, the cassette including a frame and a plate hinge-coupled to the frame at a first end of the plate to tilt about the first end according to an amount of paper stacked thereon.  
   
   
       14 . A feed cassette, including a frame to be attachable to an image forming apparatus, the cassette comprising: 
 a plate to rotate about an attachment of the plate and the frame in accordance with an amount of paper stacked thereon, the apparatus sequentially drawing pieces of the paper thereinto;    a tilting system, including a body biased to remain in contact with the plate during the rotation thereof and a hinge to connect the body with the frame about which the body rotates as the plate rotates; and    a means for preventing a drawing of overlapping pieces of paper into the apparatus within a range of angles relative to the plate supported by the tilting system.    
   
   
       15 . The cassette according to  claim 14 , wherein the image forming apparatus is a laser printer.  
   
   
       16 . The cassette according to  claim 15 , wherein the laser printer comprises: 
 a printer cartridge;    a scanning unit to form a latent image on an OPC (opto photo-organic conductor) drum of the printer cartridge;    a transfer roller to engage and rotate with the OPC drum so as to cause the paper to be transferred between the transfer roller and the OPC drum;    a fixing roller to fix a toner transferred on the paper; and    a feed roller to pick up the paper stacked on the plate.    
   
   
       17 . The cassette according to  claim 14 , further comprising a spring to bias the plate in a direction opposite to the direction of rotation due to the amount of paper stacked therein.  
   
   
       18 . The cassette according to  claim 14 , wherein the means for preventing a drawing of overlapping pieces of paper into the apparatus comprises an overlap preventing part having a frictional surface attached thereto.  
   
   
       19 . The cassette according to  claim 14 , wherein the body of the tilting system comprises a curved surface.  
   
   
       20 . The cassette according to  claim 14 , further comprising an elastic member to bias the body toward the plate.  
   
   
       21 . A method of preventing edge folding of paper fed to an image forming apparatus comprising automatically tilting an overlap preventing part of a feed cassette attached to the image forming apparatus in accordance with an amount of rotation of a plate on which paper to be fed to the apparatus is stacked.