Sheet ejection device and image forming apparatus incorporating the sheet ejection device

Abstract

A sheet ejection device includes a sheet stacker, a retainer, and a biasing member. The sheet stacker has a stacker face and a coupling portion. The sheet stacker is configured to stack a sheet on the stacker face. The retainer has a coupling portion and an adjuster configured to rotate the sheet stacker to adjust an angle of the stacker face. The retainer is configured to retain the sheet stacker to be movable in a vertical direction. The biasing member is coupled to the sheet stacker and the retainer to apply a biasing force to bias the sheet stacker in an upward direction to the retainer. The sheet stacker is configured to move in a downward direction against the biasing force, as a number of sheets stacked on the stacker face increases. The coupling portion of the retainer is configured to move when the adjuster rotates the sheet stacker.

What is claimed is: 
     
         1 . A sheet ejection device comprising:
 a sheet stacker having a stacker face and a coupling portion,   the sheet stacker configured to stack a sheet on the stacker face;   a retainer having a coupling portion and an adjuster configured to rotate the sheet stacker to adjust an angle of the stacker face,   the retainer configured to retain the sheet stacker to be movable in a vertical direction; and   a biasing member coupled to the sheet stacker and the retainer and configured to apply a biasing force to bias the sheet stacker in an upward direction to the retainer,   the sheet stacker being configured to move in a downward direction against the biasing force of the biasing member, as a number of sheets stacked on the stacker face of the sheet stacker increases,   the coupling portion of the retainer, to which the biasing member is coupled, being configured to move when the adjuster of the retainer rotates the sheet stacker.   
     
     
         2 . The sheet ejection device according to  claim 1 ,
 wherein the coupling portion of the retainer moves to prevent the biasing force of the biasing member from varying when the adjuster rotates the sheet stacker.   
     
     
         3 . The sheet ejection device according to  claim 1 ,
 wherein the retainer includes:
 a fixed retaining portion on which the coupling portion of the retainer is movably disposed; 
 a rotary retaining portion rotatably held relative to the fixed retaining portion; and 
 a movable member that is the adjuster configured to move in a given direction to rotate the rotary retaining portion; and 
   wherein the coupling portion of the retainer is configured to move along with movement of the movable member.   
     
     
         4 . The sheet ejection device according to  claim 1 , further comprising:
 a guide configured to guide the sheet stacker in movement in the vertical direction.   
     
     
         5 . The sheet ejection device according to  claim 1 , further comprising:
 a stopper configured to restrict movement of the sheet stacker in the upward direction.   
     
     
         6 . The sheet ejection device according to  claim 1 ,
 wherein the adjuster is configured to be operated manually.   
     
     
         7 . The sheet ejection device according to  claim 1 ,
 wherein the biasing member is a compression spring.   
     
     
         8 . An image forming apparatus comprising:
 an image forming device configured form an image on a sheet;   a sheet ejection unit configured to eject the sheet on which the image is formed by the image forming device; and   the sheet ejection device according to  claim 1 , configured to stack the sheet ejected by the sheet ejection unit.