Image forming apparatus

Abstract

An image forming apparatus includes a sheet cassette, a sheet feed roller, and a separating blade. An image forming section and a sheet conveying path for conveying a sheet to the image forming section are placed in a position within the width of a cassette body defined in a sheet feeding direction and above the cassette. The tip of the separating blade is placed in a portion of stacked sheets accommodated in the cassette between a front end portion and a rear end portion of the cassette. The sheet feed roller is placed in a position between the front end portion and the rear end portion of the cassette and apart from the tip of the separating blade toward the rear end portion.

What is claimed is: 
     
         1 . An image forming apparatus comprising:
 a sheet cassette configured to accommodate stacked sheets;   a separating member configured to separate an uppermost sheet from the stacked sheets accommodated in the sheet cassette;   a sheet feed roller configured to feed the uppermost sheet from the stacked sheets accommodated in the sheet cassette;   an image forming section configured to form an image on the sheet fed from the sheet cassette; and   a sheet conveying path placed between the sheet cassette and the image forming section,   wherein the image forming section and the sheet conveying path are placed in a position within a width of the sheet cassette defined between a front end and a rear end of the cassette in a sheet feeding direction and above the sheet cassette,   the separating member has a tip to be placed to contact with a portion of the stacked sheets accommodated in the sheet cassette between the front end and the rear end of the cassette, and   the sheet feed roller is placed in a position between the front end and the rear end of the sheet cassette and apart from the tip of the separating member toward the rear end of the sheet cassette.   
     
     
         2 . The image forming apparatus according to  claim 1 , further including a sheet feed roller controller configured to control the sheet feed roller to rotate reversely to feed the uppermost sheet of the stacked sheets in a direction opposite to the sheet conveying path and thereafter rotate forwardly to feed the sheet in a direction toward the sheet conveying path. 
     
     
         3 . The image forming apparatus according to  claim 2 , wherein an amount of reverse rotation of the sheet feed roller to be controlled by the sheet feed roller controller is determined to an amount of rotation at which a leading end of a sheet is moved to a position between the tip of the separating member and the sheet feed roller. 
     
     
         4 . The image forming apparatus according to  claim 1 , further including a press-contact member configured to bring the tip of the separating member into press-contact with the uppermost sheet of the stacked sheets accommodated in the sheet cassette. 
     
     
         5 . The image forming apparatus according to  claim 1 , further including a conveying roller configured to convey the sheet toward the sheet conveying path, the sheet having been fed by the sheet feed roller from the stacked sheets accommodated in the sheet cassette and separated by the separating member. 
     
     
         6 . The image forming apparatus according to  claim 5 , further including a guide member holding the separating member at one end, the guide member being configured to be rotatable about a position opposite to the separating member and to guide the sheet separated by the separating member toward the sheet conveying path,
 wherein the conveying roller is provided at the other end of the guide member opposite to the separating member.   
     
     
         7 . The image forming apparatus according to  claim 5 , further including a conveying roller controller configured to control the conveying roller to start rotation to convey the sheet toward the sheet conveying path before the leading end of the uppermost sheet of the stacked sheets accommodated in the sheet cassette reaches the conveying roller. 
     
     
         8 . The image forming apparatus according to  claim 2 , further including:
 a conveying roller configured to convey the sheet toward the sheet conveying path, the sheet having been fed by the sheet feed roller from the stacked sheets accommodated in the sheet cassette and separated by the separating member;   a guide member holding the separating member at one end, the guide member being configured to be rotatable about a position opposite to the separating member and to guide the sheet separated by the separating member toward the sheet conveying path,   wherein the conveying roller is provided at the other end of the guide member opposite to the separating member, and   a conveying roller controller configured to control the conveying roller to start rotation to feed the sheet toward the sheet conveying path after the sheet feed roller is started to rotate forwardly but before the leading end of the uppermost sheet of the stacked sheets accommodated in the sheet cassette reaches the conveying roller.   
     
     
         9 . The image forming apparatus according to  claim 1 , wherein the sheet cassette includes a lifting plate having an angularly bent or round curved shape to load the stacked sheets in the form of an upward convex curve. 
     
     
         10 . The image forming apparatus according to  claim 1 , wherein the sheet cassette includes a slanted surface at the rear end, the slanted surface being so slanted as to be more apart from the front end of the sheet cassette with distance from a bottom plate of the sheet cassette. 
     
     
         11 . The image forming apparatus according to  claim 10 , wherein the slanted surface is made of a high friction member having a larger friction coefficient than a material forming other portions of the sheet cassette than the slanted surface. 
     
     
         12 . The image forming apparatus according to  claim 11 , wherein the high friction member is made of cork. 
     
     
         13 . The image forming apparatus according to  claim 11 , wherein the high friction member is made of rubber.