Image forming apparatus

Abstract

The present invention provides an image forming apparatus that can perform stable sheet conveyance, regardless of whether a sheet processing apparatus is connected thereto. The image forming apparatus can be connected to a sheet processing apparatus that performs post processing on each conveyed sheet. The image forming apparatus includes: a pair of discharge rollers that are located at the discharge outlet of the image forming main body for sheet conveyance, and have rotational members arranged so as to alternately face both sides of each sheet in the direction perpendicular to the sheet conveying direction; and an upper discharge roller holding member that changes the center distance between the discharge rollers from a first center distance observed when the sheet processing apparatus is not connected to the image forming main body to a second center distance observed when the sheet processing apparatus is connected to the image forming main body to convey a sheet to the sheet processing apparatus.

1 . An apparatus to which a sheet processing apparatus that performs post processing on sheets discharged from a main body of the apparatus can be connected, the apparatus comprising:
 a discharge portion which discharges a sheet from the main body of the apparatus; and   a curvature providing portion, located in the discharge portion, which gives curvature to the sheet to be discharged and enables to release the curvature, the curvature being directed in a direction perpendicular to the sheet discharging direction,   the curvature providing portion being engaged with an engaging portion to the sheet processing apparatus, thereby releasing the curvature to be provided to the sheet when the sheet processing apparatus is connected to the main body of the apparatus.   
   
   
       2 . The apparatus according to  claim 1 , wherein
 the discharge portion comprises a pair of discharge rollers having a plurality of rotational members arranged so as to alternately face both sides of the sheet, and   the curvature providing portion changes the center distance between the pair of discharge rollers so as to change the amount of the curvature to be provided to the sheet.   
   
   
       3 . The apparatus according to  claim 2 , further comprising:
 a biasing member which applies a force to the pair of discharge rollers toward each other.   
   
   
       4 . An apparatus to which a sheet processing apparatus that performs post processing on sheets discharged from a main body of the apparatus can be connected, the apparatus comprising:
 a pair of discharge rollers which discharge a sheet from the main body of the apparatus; and   a curvature providing portion, located in the discharge portion, which gives curvature to the sheet to be discharged and changes the center distance between the pair of discharge rollers, the curvature being directed in a direction perpendicular to the sheet discharging direction,   the curvature providing portion being engaged with an engaging portion provided to the sheet processing apparatus, thereby changes the center distance between the pair of discharge rollers so as to reduce the amount of the curvature to be provided to the sheet when the sheet processing apparatus is connected to the main body of the apparatus.   
   
   
       5 . The apparatus according to  claim 4 , wherein
 the pair of discharge rollers having a plurality of rotational members arranged so as to alternately face both sides of the sheet.   
   
   
       6 . The apparatus according to  claim 4 , further comprising:
 a biasing member which applies a force to the pair of discharge rollers toward each other.