Abstract:
A feeder that stores a sheet used to form an image in an image forming apparatus main body and that is configured to be drawn out from the image forming apparatus main body in a perpendicular direction to a sheet conveying direction. The feeder includes: a separation member that is in press-contact with a sheet feed member disposed in the image forming apparatus main body for separating a stored sheet in cooperation with the sheet feed member; an arm part that is attached to the separation member, the separation member being rotatably attached through the arm part; and a rotation mechanism that rotates the separation member downward through the arm part and releases the press contact with the sheet feed member when the feeder is drawn out from the image forming apparatus main body.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2008-304289 filed on Nov. 28, 2008. 
     BACKGROUND 
     1. Technical Field 
     This invention relates to a feeder and an image forming apparatus. 
     2. Related Art 
     A sheet feed tray for storing sheets used to form an image exists in an image forming apparatus. 
     If a sheet stored in a sheet feed tray runs out, the user draws out the sheet feed tray from the image forming apparatus and replenishes the sheet storage portion of the drawn-out and exposed sheet feed tray with sheets. 
     On the other hand, to convey a sheet stored in the sheet feed tray at the image forming time, a pickup roller exerts a sheet feed pressure on a stored sheet and a feed roller and a retard roller exert a separation pressure on a conveyed sheet to separate conveyed sheets overlapping each other. 
     SUMMARY 
     According to an aspect of the invention, a feeder that stores a sheet used to form an image in an image forming apparatus main body and that is configured to be drawn out from the image forming apparatus main body in a perpendicular direction to a sheet conveying direction, the feeder includes: a separation member that is in press-contact with a sheet feed member disposed in the image forming apparatus main body for separating a stored sheet in cooperation with the sheet feed member; an arm part that is attached to the separation member, the separation member being rotatably attached through the arm part; and a rotation mechanism that rotates the separation member downward through the arm part and releases the press contact with the sheet feed member when the feeder is drawn out from the image forming apparatus main body. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiment(s) of the present invention will be described in detail based on the following figures, wherein: 
         FIGS. 1A and 1B  are configuration drawings to show an outline of an image forming apparatus  1 ; 
         FIG. 2  is a schematic drawing to show a state in which a nip state is released when a sheet feed tray  20  is placed and is drawn out; 
         FIG. 3  is a schematic drawing to show various components placed in the sheet feed tray  20 ; 
         FIGS. 4A and 4B  are schematic drawings to show various components placed in the sheet feed tray  20 ; 
         FIGS. 5A and 5B  are schematic drawings to show a nip state between a retard roller  21  and a feed roller  6 ; 
         FIGS. 6A ,  6 B and  6 C are schematic drawings to show how the retard roller  21  moves down when the sheet feed tray  20  is drawn out; 
         FIG. 7  is a schematic drawing to show the positional relationship between the feed roller  6  and the retard roller  21  in a nip state; 
         FIGS. 8A ,  8 B and  8 C are schematic drawings to show how the retard roller  21  moves down when the sheet feed tray  20  is pushed; 
         FIGS. 9A and 9B  are schematic drawings to show a protective cover  27  and a finger insertion hole  28 ; 
         FIG. 10  is a schematic drawing to show how the protective cover  27  is closed; 
         FIG. 11  is a schematic drawing to show a chute shape made up of the sheet feed tray  20  and the image forming apparatus  1 ; 
         FIG. 12  is a schematic drawing to show a state in which the sheet feed tray  20  has been drawn out from the image forming apparatus  1 ; 
         FIGS. 13A ,  13 B and  13 C are schematic drawings to show how the sheet feed tray  20  is separated from the image forming apparatus  1 ; 
         FIG. 14  is a schematic drawing to show various components in the sheet feed tray  20  having a handle  31 ; and 
         FIGS. 15A and 15B  are schematic drawings to show motion of the various components in the sheet feed tray  20  having the handle  31 . 
     
    
    
     DETAILED DESCRIPTION 
     An exemplary embodiment of the invention will be discussed in detail with reference to the accompanying drawings. 
     To begin with, an image forming apparatus  1  having a nip release mechanism of a retard roller as a separation member will be discussed with reference to  FIGS. 1A and 1B . 
       FIG. 1A  is a configuration drawing to show an outline of the image forming apparatus  1 , and  FIG. 1B  is a schematic drawing to show a sheet storage tray and a sheet conveying direction. 
     The image forming apparatus  1  has a scanner section  2 , a display/operation section  3 , a control section  4 , a pickup roller  5 , a feed roller  6 , a print engine  7 , a sheet feed tray  20 , and a retard roller  21 . 
     The scanner section  2  is a unit for applying light to a document and reading an image of the document as image data. 
     The display/operation section  3  is implemented as a liquid crystal touch panel for displaying information for the user and accepting a command from the user. 
     The control section  4  controls the whole image forming apparatus  1 . 
     The pickup roller  5  delivers a sheet in a sheet conveying direction from the sheet feed tray  20 . 
     The feed roller  6  and the retard roller  21  placed in the sheet feed tray  20  enter a nip state in which they are in press-contact with each other at a predetermined separation pressure when the sheet feed tray  20  is completely housed in the image forming apparatus  1 . 
     The feed roller  6  rotates in a direction feeding the sheet delivered by the pickup roller  5  from the sheet feed tray  20  in the sheet conveying direction. 
     A drive system of the retard roller  21  is provided with a torque limiter. If two or more sheets enter the nip between the feed roller  6  and the retard roller  21 , the retard roller  21  rotates backward for returning any other sheet than the conveyed sheet in the opposite direction to the conveying direction. When one sheet is sandwiched between the feed roller  6  and the retard roller  21 , the retard roller  21  rotates in association with the feed roller  6  as the torque limiter is turned off. 
     When no sheet enters the nip between the feed roller  6  and the retard roller  21 , the retard roller  21  also rotates in association with the feed roller  6  as the torque limiter is turned off. 
     Thus, when the feed roller  6  and the retard roller  21  enter the nip state, the sheet conveyed from the sheet feed tray  20  is conveyed to the print engine  7  one sheet at a time. 
     The print engine  7  performs processing of forming an image on the sheet conveyed one at a time by the feed roller  6  and the retard roller  21  in the nip state. 
     The sheet on which an image has been formed by the print engine  7  is discharged to a sheet discharge tray  8 . 
     The sheet feed tray  20  is a sheet storage case that can be placed in and drawn out from the image forming apparatus  1 ; it contains the retard roller  21 . 
     The sheet feed tray  20  is pushed into and is drawn out from the image forming apparatus  1  along a drawing-out rail. 
     As shown in  FIG. 1B , the tray drawing-out direction to draw out the sheet feed tray  20  from the image forming apparatus  1  is at the right angle to the sheet conveying direction of conveying a sheet in the sheet feed tray  20 . When the sheet feed tray  20  is completely housed in the image forming apparatus  1  and it is possible to form an image on a sheet in the sheet feed tray  20 , the feed roller  6  placed in the main body of the image forming apparatus  1  and the retard roller  21  placed in the sheet feed tray  20  are in a nip state. 
     However, to draw out and separate the sheet feed tray  20  from the image forming apparatus  1  because of sheet replacement, etc., the image forming apparatus  1  has a configuration in which the nip state between the feed roller  6  and the retard roller  21  is released as the sheet feed tray  20  is drawn out from the main body of the image forming apparatus  1 , so that an interference problem of the feed roller  6  and the retard roller  21  rubbing against each other when the sheet feed tray  20  is placed and is drawn out is solved. 
     Next, a state in which the nip state is released when the sheet feed tray  20  is placed and is drawn out will be discussed with reference to  FIG. 2 . 
       FIG. 2  is a schematic drawing to show the state in which the nip state is released when the sheet feed tray  20  is placed and is drawn out. 
     As in a drawing indicated by reference numeral  201 , when the sheet feed tray  20  is completely housed in the image forming apparatus  1  so that the sheet feed tray  20  is used and it is made possible to form an image, the feed roller  6  placed in the main body of the image forming apparatus  1  and the retard roller  21  placed in the sheet feed tray  20  are in a nip state in which they are in press-contact with each other at a predetermined separation pressure. 
     However, when the sheet feed tray  20  is drawn out from the main body of the image forming apparatus  1 , a tip  33  of a ratchet component  25  placed in the sheet feed tray  20  moves down and accordingly the retard roller  21  falls as in a drawing indicated by reference numeral  202 . 
     Then, the nip state between the feed roller  6  and the retard roller  21  is released. 
     When the sheet feed tray  20  is drawn out to a predetermined position, the tip  33  of the ratchet component  25  placed in the sheet feed tray  20  moves up and accordingly the retard roller  21  rises. 
     When the sheet feed tray  20  is drawn out, then the sheet feed tray  20  is replenished with sheets, etc., and then is pushed into the image forming apparatus  1 . 
     When the sheet feed tray  20  is pushed into a predetermined housing position of the image forming apparatus  1 , the tip  33  of the ratchet component  25  placed in the sheet feed tray  20  also moves down and as the tip  33  of the ratchet component  25  moves down, the retard roller  21  also falls as in a drawing indicated by reference numeral  204 . 
     Thus, when the sheet feed tray  20  is drawn out and is pushed, the tip  33  of the ratchet component  25  moves down and accordingly the retard roller  21  falls, so that the retard roller  21  placed in the sheet feed tray  20  and the feed roller  6  placed in the main body of the image forming apparatus  1  do not come in contact with each other and the sheet feed tray  20  is drawn out and pushed smoothly. 
     Next, the retard roller  21 , the ratchet component  25 , etc., placed in the sheet feed tray  20  will be discussed with reference to  FIG. 3 . 
       FIG. 3  is a schematic drawing to show the retard roller  21 , the ratchet component  25 , etc., placed in the sheet feed tray  20 . 
     As shown in  FIG. 3 , the retard roller  21 , an assembly  22 , a rotation component  23 , a component  24 , the ratchet component  25 , and a spring  26  are placed in the sheet feed tray  20 . 
     The spring  26  pulls the tip  33  of the ratchet component  25  so that the tip points upward. 
     The ratchet component  25  makes a rotation move at a predetermined angle with the rotation axis as a supporting point, whereby the tip  33  portion of the ratchet component  25  moves up or down relative to the sheet feed tray  20 . 
     The spring  16  adds a force to the ratchet component  25  at all times so that the ratchet component  25  makes a rotation move in a direction in which the tip  33  of the ratchet component  25  moves up. 
     The component  24  is placed so as to move back and forth in the tray drawing-out direction as the tip  33  of the ratchet component  25  moves up and down. 
     The rotation component  23  is placed so as to make a rotation move with a supporting point as an axis as the component  24  moves back and forth in the tray drawing-out direction. 
     The assembly  22  is an assembly including the retard roller  21  and is placed so as to make a rotation move up and down with a supporting point as an axis with a rotation move of the rotation component  23 . 
     Thus, as the tip  33  of the ratchet component  25  placed in the sheet feed tray  20  moves up and down, the component  24  moves back and forth in the tray drawing-out direction, the rotation component  23  makes a rotation move, and the assembly  22  makes a rotation move up and down. 
     Since the retard roller  21  is placed in the assembly  22 , the retard roller  21  moves up and down relative to the sheet feed tray  20  as the assembly  22  makes a rotation move up and down. 
     This means that the retard roller  21  moves up and down as the tip  33  of the ratchet component  25  moves up and down. 
     Next, the components in the sheet feed tray  20  in the nip state between the retard roller  21  and the feed roller  6  and those in the sheet feed tray  20  when the nip state is released will be discussed with reference to  FIGS. 4A and 4B . 
       FIGS. 4A and 4B  are schematic drawings to show various components placed in the sheet feed tray  20  and the retard roller  21  nipped with the feed roller  6 ;  FIG. 4A  is a schematic drawing to show the case where the sheet feed tray  20  is completely housed in the image forming apparatus  1  and the feed roller  6  and the retard roller  21  are in a nip state; and  FIG. 4B  is a schematic drawing to show the case where the sheet feed tray  20  is drawn out and the nip state between the feed roller  6  and the retard roller  21  is released. 
     When the sheet feed tray  20  is completely housed in the image forming apparatus  1  and an image can be formed as a sheet is conveyed from the sheet feed tray  20 , the feed roller  6  and the retard roller  21  placed in the image forming apparatus  1  are in the nip state as shown in  FIG. 4A . 
     However, when drawing out the sheet feed tray  20  from the image forming apparatus  1  starts, the tip  33  of the ratchet component  25  placed in the sheet feed tray  20  comes in contact with a convex portion  9  placed in the main body of the image forming apparatus  1  and as the sheet feed tray  20  is drawn out, the tip  33  of the ratchet component  25  is brought down by the convex portion  9  as shown in  FIG. 4B . 
     That is, the sheet feed tray  20  makes a parallel move relative to the main body of the image forming apparatus  1 , so that the ratchet component  25  placed in the sheet feed tray  20  also makes a parallel move relative to the convex portion  9  placed in the image forming apparatus  1 . At the time, a protrusion portion of the tip  33  of the ratchet component  25  passes through below the convex portion  9  placed in the main body of the image forming apparatus  1 , as shown in  FIGS. 4A and 4B . To allow the ratchet component  25  to pass through below the convex portion  9 , the tip  33  of the ratchet component  25  needs to move down. Thus, to draw out the sheet feed tray  20  by a force of a human being, mechanically, when the ratchet component  25  of the sheet feed tray  20  passes through below the convex portion  9  placed in the image forming apparatus  1 , the ratchet component  25  makes a rotation move and the tip  33  of the ratchet component  25  moves down. 
     As shown in  FIG. 4B , if the tip  33  of the ratchet component  25  moves down, the assembly  22  moves down as described above, so that the nip state between the retard roller  21  and the feed roller  6  is released. 
     Next, the nip state between the retard roller  21  and the feed roller  6  is released will be discussed with reference to  FIGS. 5A and 5B . 
       FIGS. 5A and 5B  are schematic drawings to show the nip state between the retard roller  21  and the feed roller  6 ;  FIG. 5A  is a schematic drawing to show a nip state; and  FIG. 5B  is a schematic drawing to show a nip release state. 
     As shown in  FIG. 5A , in the nip state between the retard roller  21  and the feed roller  6 , the feed roller  6  and the retard roller  21  are in press-contact with each other at a predetermined separation pressure. 
     However, when the assembly  22  moves down as the tip  33  of the ratchet component  25  falls, the feed roller  6  and the retard roller  21  are brought away from each other and the nip state is released. 
     The assembly  22  and the retard roller  21  are integrated and the retard roller  21  also falls as the assembly  22  falls. 
     When the sheet feed tray  20  is drawn out or is pushed, the feed roller  6  placed in the main body of the image forming apparatus  1  and the retard roller  21  placed in the sheet feed tray  20  to be drawn out or pushed are at a distance from each other as shown in  FIG. 5B . Thus, when the sheet feed tray  20  is drawn out or is pushed, the feed roller  6  and the retard roller  21  do not come in contact with each other. 
     Next, how the retard roller  21  moves down when the sheet feed tray  20  is drawn out from the image forming apparatus  1  will be discussed with reference to  FIGS. 6A ,  6 B and  6 C. 
       FIGS. 6A ,  6 B and  6 C are schematic drawings to show how the retard roller  21  moves down when the sheet feed tray  20  is drawn out;  FIG. 6A  is a schematic drawing to show a state in which the sheet feed tray  20  is completely housed in the image forming apparatus  1 ;  FIG. 6B  is a schematic drawing to show a state in which the sheet feed tray  20  is drawn out from the image forming apparatus  1  and the retard roller  21  moves down; and  FIG. 6C  is a schematic drawing to show a state in which the sheet feed tray  20  is drawn out to a predetermined position from the image forming apparatus  1  and the retard roller  21  rises. 
     As shown in  FIG. 6A , when the sheet feed tray  20  is completely housed in the image forming apparatus  1 , the feed roller  6  and the retard roller  21  are in the nip state, a sheet stored in the sheet feed tray  20  is conveyed, and an image can be formed. 
     To draw out the sheet feed tray  20  from the image forming apparatus  1 , the tip  33  of the ratchet component  25  placed in the sheet feed tray  20  passes through below the convex portion  9  placed in the main body of the image forming apparatus  1  as the tip  33  moves down. The sheet feed tray  20  has the mechanism in which the retard roller  21  moves down if the ratchet component  25  moves down. Thus, the retard roller  21  moves down, the nip state between the feed roller  6  and the retard roller  21  is released, and the sheet feed tray  20  is drawn out. 
     When the sheet feed tray  20  is drawn out to a predetermined length, the state in which the tip  33  of the ratchet component  25  placed in the sheet feed tray  20  passes through below the convex portion  9  terminates and the tip  33  of the ratchet component  25  moves up, as shown in  FIG. 6C . 
     When the tip  33  of the ratchet component  25  moves up, the retard roller  21  moves up. When the sheet feed tray  20  is drawn out and the retard roller  21  moves up, the feed roller  6  and the retard roller  21  are placed where they do not come in contact with each other. Thus, there is no problem if the sheet feed tray  20  is drawn out as it is. 
     When the sheet feed tray  20  is drawn out, the retard roller  21  moves down in the case where the tip  33  of the ratchet component  25  is moved down by the convex portion  9 . Thus, the length in which the state in which the retard roller  21  moves down is maintained depends on the length of the convex portion  9  in the drawing-out direction of the sheet feed tray. 
     Next, the length of the convex portion  9  for maintaining the state in which the tip  33  of the ratchet component  25  is moved down will be discussed with reference to  FIG. 7 . 
       FIG. 7  is a drawing to show the positional relationship between the feed roller  6  and the retard roller  21  in the nip state. 
     When the feed roller  6  and the retard roller  21  are in the nip state as in  FIG. 7 , a length from an opposite end part (reference number  701 ) of the retard roller  21  to the sheet feed tray drawing out port to an end part (reference number  702 ) of the feed roller  6  on the side of the sheet feed tray drawing out port becomes necessary to maintain the state in which the retard roller  21  moves down when the sheet feed tray  20  is drawn out. 
     Then, the length of the convex portion  9  for moving down the tip  33  of the ratchet component  25  becomes equal to or greater than the length from the opposite end part (reference number  701 ) of the retard roller  21  to the sheet feed tray drawing out port to the end part (reference number  702 ) of the feed roller  6  on the side of the sheet feed tray drawing out port. 
     Next, how the retard roller  21  moves down when the sheet feed tray  20  is pushed into the image forming apparatus  1  will be discussed with reference to  FIGS. 8A ,  8 B and  8 C. 
       FIGS. 8A ,  8 B and  8 C are schematic drawings to show how the retard roller  21  moves down when the sheet feed tray  20  is pushed;  FIG. 8A  is a schematic drawing to show a state in which the sheet feed tray  20  is drawn out from the image forming apparatus  1  until the tip  33  of the ratchet component  25  moves up;  FIG. 8B  is a schematic drawing to show a state in which the sheet feed tray  20  is pushed into the image forming apparatus  1  and the tip  33  of the ratchet component  25  placed in the sheet feed tray  20  moves down; and  FIG. 8C  is a schematic drawing to show that the sheet feed tray  20  is completely housed in the image forming apparatus  1  and the retard roller  21  and the feed roller  6  are in the nip state. 
     As shown in  FIG. 8A , the tip  33  of the ratchet component  25  placed in the sheet feed tray  20  moves up and the sheet feed tray  20  is not housed in the image forming apparatus  1 . 
     In this state, the retard roller  21  moves up and if the state in which the retard roller  21  moves up is maintained as it is and the sheet feed tray  20  is pushed, the retard roller  21  and the feed roller  6  come in contact with each other and there is the fear of damage to the components. 
     Then, if the sheet feed tray  20  is pushed to a predetermined position, the tip  33  of the ratchet component  25  placed in the sheet feed tray  20  passes through below the convex portion  9  placed in the main body of the image forming apparatus  1  and thus the tip  33  moves down and the retard roller  21  moves down. 
     Then, to push the sheet feed tray  20 , it is pushed in a state in which the retard roller  21  moves down, the retard roller  21  and the feed roller  6  do not come in contact with each other, and the sheet feed tray  20  is pushed into the image forming apparatus  1 . 
     The convex portion is formed so that the tip  33  of the ratchet component  25  moves up in a state in which the sheet feed tray  20  is pushed into the image forming apparatus  1  to the end in the pushing direction and the sheet feed tray  20  is completely housed in the image forming apparatus  1 . 
     Consequently, when the sheet feed tray  20  is completely housed in the image forming apparatus  1 , the ratchet component  25  moves up and the retard roller  21  rises, so that the feed roller  6  and the retard roller  21  are placed in the nip state. 
     Next, a protective cover for holding the assembly with which the retard roller  21  placed in the sheet feed tray  20  is integrated will be discussed with reference to  FIGS. 9A and 9B . 
       FIGS. 9A and 9B  are schematic drawings to show a protective cover  27  placed in the sheet feed tray  20  and a finger insertion hole  28  to open the protective cover;  FIG. 9A  is a schematic drawing to show a state in which the protective cover  27  is closed and the assembly  22  is housed in the sheet feed tray  20 ; and  FIG. 9B  is a schematic drawing to show a state in which the protective cover  27  is opened with a finger inserted into the finger insertion hole  28  provided in the sheet feed tray  20 . 
     As shown in  FIG. 9A , the protective cover  27  housing the assembly  22  with which the retard roller  21  is integrated and the finger insertion hole  28  into which a finger is inserted to open the protective cover  27  are placed in the sheet feed tray  20 . 
     The finger insertion hole  28  is formed by providing a notch in the sheet feed tray  20  and is shaped for allowing a finger to be inserted, as shown in  FIGS. 9A and 9B . 
     When a finger is inserted into the finger insertion hole  28  of the sheet feed tray  20  and the protective cover  27  is opened, the protective cover  27  rotates with the joint part to the sheet feed tray  20  as an axis and pops up, enabling the user to take out the assembly  22 . 
     The rotation axis of the protective cover  27  points in the perpendicular direction to the sheet conveying direction. 
     When the protective cover  27  is thus opened, the user is enabled to take out the assembly  22 ; the assembly  22  is taken out upward as shown in  FIG. 9B . 
     A spring  29  is placed in the protective cover  27  and is joined to the sheet feed tray  20 . 
     The spring  29  is placed in a state in which it adds a force in a direction opposite to the direction of opening the protective cover  27  with a finger inserted from the finger insertion hole  28 , namely, in the direction of closing the protective cover as shown in  FIG. 9A . 
     When the finger inserted into the finger insertion hole  28  is pulled out from the finger insertion hole  28 , the protective cover  27  opened as shown in  FIG. 9B  rotates with the joint part as an axis and moves down to the former closed state as shown in  FIG. 10 . 
     The finger is pulled out from the finger insertion hole  28 , whereby the protective cover  27  is automatically closed by the spring  29 . Thus, when the sheet feed tray  20  is pushed into the image forming apparatus  1 , a collision between the protective cover  27  and the front cover of the image forming apparatus  1  caused by forgetting about closing the protective cover  27  is prevented. 
     Thus, the assembly  22  placed in the sheet feed tray  20  is easily replaced as a finger is inserted from the finger insertion hole  28  and the protective cover  27  is opened. 
     Since abrasion of the retard roller  21  is intense, easy replacing of the assembly  22  is convenient for the user. 
     Thus, when the retard roller  21  is placed in the sheet feed tray  20 , the sheet feed tray  20  can be placed in and removed from the image forming apparatus  1  and thus the retard roller  21  integrated with the assembly  22  is easy to replace. 
     Next, the structure of the image forming apparatus  1  in which the sheet feed tray  20  is housed will be discussed with reference to  FIG. 11 . 
       FIG. 11  is a schematic drawing to show a sheet conveying chute shape made up of the main body of the image forming apparatus  1  and the sheet feed tray  20  in a state in which the sheet feed tray  20  is completely housed in the image forming apparatus  1 . However, components of the ratchet component  25 , etc., are not shown. 
     As shown in  FIG. 11 , the chute shape made up of the image forming apparatus  1  and the sheet feed tray  20  in one piece is formed to convey a sheet stored in the sheet feed tray  20  to the print engine  7  placed above the sheet feed tray  20 . 
     The protective cover  27  of the sheet feed tray  20  forms the chute shape and a component  30  formed with the chute shape is placed in the image forming apparatus  1  of the sheet conveying destination of the protective cover  27 . 
     The chute shape for conveying a sheet to the print engine  7  is formed not only in the protective cover  27 , but also in the sheet feed tray  20  in the opposite direction to the tray drawing-out direction of the protective cover (reference number  1101 ). 
     The chute shape projects upward so as to introduce a sheet upward for the purpose of conveying the sheet to the upward print engine. 
     However, the chute shape of the sheet feed tray  20  of the image forming apparatus  1  is formed so that a part of the chute shape of the back side (the side in the opposite direction to the tray drawing-out direction) of the image forming apparatus  1  is formed on the main body side of the image forming apparatus  1  (reference number  1102 ). 
     That is, as indicated by the reference number  1102  in  FIG. 11 , the projecting portion forming the chute shape of the sheet feed tray  20  is made lower than any other portion and the main body side of the image forming apparatus  1  bears the chute shape in the lower part. 
     Thus, the back side portion of the sheet feed tray  20  is made lower than others (reference number  1102 ). 
     Next, the chute shape made lower of the sheet feed tray  20  when the sheet feed tray  20  is drawn out from the image forming apparatus  1  will be discussed with reference to  FIG. 12 . 
       FIG. 12  is a schematic drawing to show a state in which the sheet feed tray  20  has been drawn out from the image forming apparatus  1 . 
     As shown in  FIG. 12 , the chute shape on the back side of the sheet feed tray  20  is formed lower than others (reference number  1201 ). 
     Thus, when the sheet feed tray  20  is separated from the image forming apparatus  1 , the projecting chute shape of the sheet feed tray  20  is prevented from coming in contact with the image forming apparatus  1  leading to occurrence of a flaw and damage to the components. 
     This means that interference between the projecting chute shape of the sheet feed tray  20  and the image forming apparatus  1  is eliminated. 
     To separate the sheet feed tray  20  from the image forming apparatus  1 , the user draws out the sheet feed tray  20  from the image forming apparatus  1  to the end along the drawing-out rail and last lifts up the sheet feed tray  20  to separate from the image forming apparatus  1 . 
     If the back side of the sheet feed tray  20  is low, when the sheet feed tray  20  is lifted up, it is prevented from coming in contact with the image forming apparatus  1 . 
     Next, how the sheet feed tray  20  is separated from the image forming apparatus  1  will be discussed with reference to  FIGS. 13A ,  13 B and  13 C. 
       FIGS. 13A ,  13 B and  13 C are schematic drawings to show how the sheet feed tray  20  is separated from the image forming apparatus  1 ;  FIG. 13A  is a schematic drawing to show a state in which the sheet feed tray  20  has been drawn out to the end of the drawing-out rail from the image forming apparatus  1 ;  FIG. 13B  is a schematic drawing to show a state in which the sheet feed tray  20  is lifted up and is separated from the image forming apparatus  1 ; and  FIG. 13C  is a schematic drawing to show a state in which the sheet feed tray  20  has been separated from the image forming apparatus  1 . However, components of the ratchet component  25 , etc., are not shown. 
     To separate the sheet feed tray  20  from the image forming apparatus  1 , the user draws out the sheet feed tray  20  to the end in the drawing-out direction from the image forming apparatus  1  and then lifts up the sheet feed tray  20 , as shown in  FIG. 13A . 
     When the sheet feed tray  20  is lifted up, the chute portion on the back side of the sheet feed tray  20  is low (reference number  1301 ) and thus does not come in contact with any component of the front cover, etc., of the image forming apparatus  1  (reference number  1302 ), as shown in  FIG. 13B . 
     Then, the user separates the lifted-up sheet feed tray  20  from the image forming apparatus  1 . 
     The sheet feed tray  20  has been described as a sheet feed tray such that the tip  33  of the ratchet component  25  placed in the sheet feed tray  20  is moved down by the convex portion  9  placed in the main body of the image forming apparatus  1  when the sheet feed tray  20  is drawn out or is pushed into the image forming apparatus  1 . However, the sheet feed tray  20  can also be configured so that the tip  33  of the ratchet component  25  is moved down by operation of a handle for drawing out the sheet feed tray  20 . 
     Next, the sheet feed tray  20  configured so that the tip  33  of the ratchet component  25  is moved down by operation of a handle  31  for drawing out the sheet feed tray  20  will be discussed with reference to  FIG. 14 . 
     As shown in  FIG. 14 , the handle  31 , a component  32 , the ratchet component  25 , the rotation component  23 , the assembly  22 , and the retard roller  21  are placed in the sheet feed tray  20  having the handle  31  (the retard roller  21  is built in the assembly  22 ). 
     As shown in  FIG. 14 , the handle  31  is a part held by a human being when drawing out or pushing the sheet feed tray  20 ; the user pulls the handle  31  in the tray drawing-out direction, whereby the component  32  is moved back and forth in the tray drawing-out direction. 
     As the user pulls the handle  31  in the tray drawing-out direction, the component  32  moves in the tray drawing-out direction. 
     As the component  32  moves in the tray drawing-out direction, it moves down the tip  33  of the ratchet component  25 . 
     As the component  32  moves in the tray drawing-out direction, it causes the rotation component  23  to make a rotation move with a supporting point as an axis. 
     The assembly  22  is an assembly containing the retard roller  21  is placed so as to make a rotation move up and down with a supporting point as an axis with the rotation move of the rotation component  23 . 
     Next, motion of the components in the sheet feed tray  20  having the handle  31  will be discussed with reference to  FIGS. 15A and 15B . 
       FIG. 15A  is a schematic drawing to show the components when the sheet feed tray  20  having the handle  31  is completely housed in the image forming apparatus  1  and the feed roller  6  and the retard roller  21  are in a nip state, and  FIG. 15B  is a schematic drawing to show the components in a state in which the handle  31  is pulled in the tray drawing-out direction and the nip state between the feed roller  6  and the retard roller  21  is released. 
     In the sheet feed tray  20  having the handle  31 , if the handle  31  is pulled in the tray drawing-out direction from the state in which the sheet feed tray  20  is completely housed in the image forming apparatus  1  and the retard roller  21  and the feed roller  6  are in the nip state as shown in  FIG. 15A , the shaft of the handle  31  rotates and causes the component  32  to move in the tray drawing-out direction. 
     When the component  32  is moved in the tray drawing-out direction, the rotation component  23  makes a rotation move, the assembly  22  falls, and the tip  33  of the ratchet component  25  also falls. Consequently, the nip state of the feed roller  6  and the retard roller  21  is released as shown in  FIG. 15B . 
     Thus, in the sheet feed tray  20  having the handle  31 , the handle  31  is pulled in the tray drawing-out direction, whereby the nip state of the feed roller  6  and the retard roller  21  is released, so that when the sheet feed tray  20  is drawn out from the state in which the sheet feed tray  20  is completely housed in the image forming apparatus  1 , the handle  31  is pulled in the tray drawing-out direction. 
     The invention can be used for a feeder and an image forming apparatus. 
     The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.