Sheet feeding device and image forming apparatus

Abstract

One aspect of the present invention provides a sheet feeding device and an image forming apparatus, in which a sheet can stably be separated and fed irrespective of stiffness of the sheet. A movable wall includes a sheet abutting surface that separates the sheet one by one by abutting on the sheet, which is stacked on a tray and fed by a feeding roller. The movable wall is movable in a sheet feeding direction, and a force applying spring applies a force to the movable wall in a direction opposite to the sheet feeding direction. A support portion supports the movable wall such that the movable wall is movable, and such that the movable wall is sloped when abutting on the sheet, which is fed by a feeding roller, and moving on a downstream side in the sheet feeding direction against an applying force of a force applying spring.

What is claimed is: 
     
         1 . A sheet feeding device comprising:
 a sheet stacking portion on which a sheet is stacked;   a sheet feeding portion which feeds the sheet stacked on the sheet stacking portion;   a separating portion which includes a separating slope, the separating slope separating the sheet one by one by abutting on the sheet fed by the sheet feeding portion, the separating portion being movable along a sheet feeding direction;   a force applying portion which applies a force to the separating portion in a direction opposite to the sheet feeding direction; and   a support portion which supports the separating portion such that the separating portion is movable, and such that the separating portion is sloped in connection with the movement when abutting on the sheet, which is fed by the sheet feeding portion, and moving on a downstream side in the sheet feeding direction against an applying force of the force applying portion.   
     
     
         2 . The sheet feeding device according to  claim 1 , wherein the support portion includes a guide portion which guides the separating portion when the separating portion moves onto the downstream side in the sheet feeding direction while sloped. 
     
     
         3 . The sheet feeding device according to  claim 2 , wherein the guide portion is formed such that an upper end position of the separating slope is higher than a level of the pre-slope upper end position when the separating portion is sloped. 
     
     
         4 . The sheet feeding device according to  claim 1 , wherein the applying force of the force applying portion is set to magnitude at which the separating portion moves when the sheet having predetermined stiffness or more abuts on the separating portion. 
     
     
         5 . The sheet feeding device according to  claim 1 , wherein the support portion includes a projection and a groove, the projection guiding the separating portion when the separating portion moves onto the downstream side in the sheet feeding direction while sloped, the projection being guided in the groove,
 a pair of the projection and the groove is disposed on each of both sides of the separating portion along the sheet feeding direction, and   when the separating portion moves on the downstream side in the sheet feeding direction, the groove disposed on an upstream side substantially horizontally or upwardly guides the projection and the groove disposed on the downstream side downwardly guides the projection.   
     
     
         6 . The sheet feeding device according to  claim 1 , further comprising a regulation portion which abuts on the separating portion to regulate the movement of the separating portion on the downstream side in the sheet feeding direction until the sheet feeding portion starts to feed the sheet. 
     
     
         7 . An image forming apparatus comprising:
 a sheet feeding device including:   a sheet stacking portion on which a sheet is stacked;   a sheet feeding portion which feeds the sheet stacked on the sheet stacking portion;   a separating portion which includes a separating slope, the separating slope separating the sheet one by one by abutting on the sheet fed by the sheet feeding portion, the separating portion being movable along a sheet feeding direction;   a force applying portion which applies a force to the separating portion in a direction opposite to the sheet feeding direction; and   a support portion which supports the separating portion such that the separating portion is movable, and such that the separating portion is sloped in connection with the movement when abutting on the sheet, which is fed by the sheet feeding portion, and moving on a downstream side in the sheet feeding direction against the applying force of the force applying portion, and   an image forming portion which forms an image on the sheet fed from the sheet feeding device.   
     
     
         8 . The image forming apparatus according to  claim 7 , wherein the support portion includes a guide portion which guides the separating portion when the separating portion moves onto the downstream side in the sheet feeding direction while sloped. 
     
     
         9 . The image forming apparatus according to  claim 8 , wherein the guide portion is formed such that an upper end position of the separating slope is higher than a level of the pre-slope upper end position when the separating portion is sloped. 
     
     
         10 . The image forming apparatus according to  claim 7 , wherein the applying force of the force applying portion is set to magnitude at which the separating portion moves when the sheet having predetermined stiffness or more abuts on the separating portion. 
     
     
         11 . The image forming apparatus according to  claim 7 , wherein the support portion includes a projection and a groove, the projection guiding the separating portion when the separating portion moves onto the downstream side in the sheet feeding direction while sloped, the projection being guided in the groove,
 a pair of the projection and the groove is disposed on each of both sides of the separating portion along the sheet feeding direction, and   when the separating portion moves on the downstream side in the sheet feeding direction, the groove disposed on an upstream side substantially horizontally or upwardly guides the projection and the groove disposed on the downstream side downwardly guides the projection.   
     
     
         12 . The image forming apparatus according to  claim 7 , further comprising a regulation portion which abuts on the separating portion to regulate the movement of the separating portion on the downstream side in the sheet feeding direction until the sheet feeding portion starts to feed the sheet.