Abstract:
A sheet receiving apparatus includes a tray swingably supported by an apparatus main body so that it is selectively put to a state of use, in which sheets can be loaded thereon, and to a state of accommodation and a regulation unit abutted against the tray for regulating the swing motion thereof to keep the state of accommodation, wherein the center of swing of the tray is arranged movably and the tray can be shifted to the state of use by releasing the swing thereof regulated by the regulation unit by moving the center of swing thereof. With this arrangement, the sheet receiving apparatus can be highly reliably arranged without an increase in a cost and has no possibility of the deformation and breakage of the parts thereof.

Description:
BACKGROUND OF THE INVENTION 
     1. Filed of the invention 
     The present invention relates to a sheet receiving apparatus which is mounted on an image forming apparatus such as a copying machine, a printer, a recording device and the like and on a sheet processing apparatus for carrying out binding and the like, and so on for loading sheets such as recording sheets and the like thereon. In particular, the present invention relates to the arrangement of a sheet receiving apparatus which can be selectively put in two states, that is, a state of use and a state of accommodation and has a center of rotation through which the two states can be selected by the rotational motion of the tray. 
     2. Description of the Related Art 
     In general, recording apparatuses are provided with a sheet tray as a sheet receiving apparatus such as a sheet feed tray for holding recording mediums on which images are to be recorded, a discharged sheet tray for holding recording mediums on which the images have been recorded, and the like. 
     In these recording apparatuses, the sheet tray is arranged such that it can be accommodated when it is not used to save a space. 
     There is a method of accommodating the sheet tray by sliding it into the main body of the recording apparatus as the accommodating methods thereof. However, a problem arises in this method in that the size of the recording apparatus main body is increased to secure a space for accommodating it. 
     To solve the above problem, there is also proposed a method of selectively putting the sheet tray in the state of use and the state of accommodation by rotating it. 
     In the above arrangement, it is necessary to hold the sheet tray by additionally providing an elastic member such as a metal spring or the like or to form an elastically deformable portion at a part of the sheet tray or at a part of a recording apparatus main body in order to keep the state of the sheet tray when it is accommodated. 
     In the above arrangement, however, a cost is increased by the addition of the elastic member such as the metal spring or the like. 
     While it has been proposed to form the elastically deformable portion at a part of the sheet tray or at a part of the recording apparatus main body without the addition of the elastic member such as the metal spring or the like to keep the state of the sheet tray when it is accommodated, there is caused a problem in that the accommodated state of the sheet tray cannot be kept due the deformation or breakage of the elastic portion. Thus, there has been desired a sheet tray having a reliable structure by which the state of accommodation of the sheet tray can be reliably kept without an increase in a cost. 
     SUMMARY OF THE INVENTION 
     An object of the present invention for solving the above problem is to provide a sheet tray having high reliability without an increases in a cost which can securely keep the state of accommodation of the sheet tray through a simple arrangement and is not broken even if it is handled somewhat violently. 
     To achieve the above object, a sheet receiving apparatus of the present invention includes a tray swingably supported by an apparatus main body so that it is selectively put to a state of use, in which sheets can be loaded thereon, and to a state of accommodation; and a regulation unit abutted against the tray for regulating the swing motion thereof to keep the state of accommodation, wherein the center of swing of the tray is arranged movably and the tray can be shifted to the state of use by releasing the swing thereof regulated by the regulation unit by moving the center of swing thereof. 
     According to a first aspect of the present invention, a sheet receiving apparatus includes a tray and a regulation unit. The tray is rotatably supported about a center of rotation by an apparatus main body to be selectively positioned in a use position, in which sheets can be loaded thereon, and in an accommodation position. The regulation unit is abuttable against the tray for regulating a rotational motion thereof when the tray is in the accommodation position to maintain the tray in the accommodation position. The center of rotation of the tray is arranged movably and the tray is shiftable from the accommodation position to the use position by permitting the rotational motion thereof, regulated by the regulation unit, by moving the center of rotation thereof. 
     According to another aspect of the present invention, a sheet receiving apparatus includes a tray, supporting means and regulation means. The tray loads a sheet. The supporting means rotatably supports the tray in a rotational motion between a use position in which the sheet is loadable thereon and an accommodation position. The regulation means abuts against the tray when in the accommodation position so as to regulate the rotational motion of the tray to thereby maintain the tray in the accommodation position. The tray is releasable from the regulation means by application of a rotational force to slide the tray over the regulation means. 
     According to yet another aspect of the present invention a sheet receiving apparatus includes a tray and a regulation means. The tray is rotatably supported about a center of rotation by an apparatus main body to be selectively positioned in a use position, in which sheets can be loaded thereon, and in an accommodation position. The regulation means abuts against the tray and regulates a rotational motion thereof when the tray is in the accommodation position to maintain the tray in the accommodation position. The center of rotation of the tray is arranged movably and the tray is shiftable from the accommodation position to the use position by permitting the rotational motion thereof, regulated by the regulation means, by moving the center of rotation thereof. 
     According to still another aspect of the present invention a sheet receiving apparatus includes a tray, a support and a regulation unit. The tray loads a sheet. The support rotatably supports the tray in a rotational motion between a use position in which the sheet is loadable thereon and an accommodation position. The regulation unit is abuttable against the tray when in the accommodation position so as to regulate the rotational motion of the tray to thereby maintain the tray in the accommodation position. The tray is releasable from the regulation unit by application of a rotational force to slide the tray over the regulation unit. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic perspective view showing an arrangement of a recording apparatus according to the present invention. 
     FIG. 2 is a schematic perspective view showing a state in which a discharged sheet tray is removed. 
     FIG. 3 is a schematic sectional view showing an arrangement of the recording apparatus according to the present invention (a state in which the discharged sheet tray is used). 
     FIG. 4 is a schematic sectional view showing an arrangement of the recording apparatus according to the present invention (a state in which the discharged sheet tray is accommodated). 
     FIG. 5 is an enlarged view showing the state of use of the discharged sheet tray according to the present invention is used. 
     FIG. 6 is an enlarged view showing the state of accommodation of the discharged sheet tray according to the present invention. 
     FIG. 7 is a view explaining the state of operation of the discharged sheet tray according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment in which the present invention is applied to an inkjet recording apparatus as an example of a recording apparatus which is a kind of an image forming apparatus will be specifically described with reference to the accompanying drawings. 
     As shown in FIG. 3, an inkjet recording apparatus  100  of the embodiment includes a recording head  1  as an image forming means mounted on a carriage  2  to form an image on a recording medium by ejecting ink thereto. The carriage  2  is supported by a carriage shaft  3  and a guide rail  4  and reciprocated in a direction perpendicular to the feed direction (direction vertical to a sheet surface) of a recording medium  201  as a sheet by a carriage drive motor (not shown) through a timing belt  5 . An image is formed on the surface of the recording medium by the ink ejected from the recording head  1  during the movement of the recording head  1  while the reciprocating movement of the recording head  1  caused by the movement of the a carriage  2  and the feed operation of the recording medium at each predetermined pitch are alternately carried out. 
     A feed roller  11  and a pinch roller  12 , which constitute a feed means for feeding recording mediums, are disposed below the a carriage  2 . In the embodiment, the recording mediums are fed one by one to a feed means from an auto sheet feeder  200  disposed rearward of the carriage  2 . 
     The recording mediums are fed from the auto sheet feeder  200  to the feed means by a sheet feed roller  202 . On the reception of a sheet feed command issued from a computer or the like connected to the apparatus  100 , the sheet feed roller  202  is rotated clockwise, separates each of a multiplicity of the recording mediums  201  from the bundle thereof loaded on the auto sheet feeder  200  and feeds them in the direction of an arrow A shown in FIG.  3 . Each recording medium  201  is fed from the sheet feed roller  202  until the extreme end thereof reaches the nip between the feed roller  11  and the pinch roller  12  and stopped thereat in a state that the recording medium  201  is curved between the nip and the sheet feed roller  202 . 
     Next, the feed roller  11  is rotated counterclockwise by a sheet feed motor (not shown), and the recording medium  201  having been fed to the feed means is fed while being clamped between the feed roller  11  and the pinch roller  12  which is urged into contact with the feed roller  11  by an urging spring  13 . 
     The recording medium  201  is fed in a left direction in FIG. 3 along the platen  10  as a recording section and stopped when the portion of the recording medium  201 , to which a first line of images is printed, reaches the recording position of the platen  10 . 
     The recording head  1  reciprocates in a direction vertical to the sheet surface while ejecting ink in accordance with image information in the state that the recording medium  201  is stopped so as to record an image having a predetermined width (recording width) in the feed direction. Thereafter, the recording medium  201  is fed by the recording width by the feed roller  11  and stopped again and images are recorded in the recording width by the recording head  1 . The images are recorded onto the recording medium  201  by alternately repeating the feed operation and the recording operation. 
     Sheet discharge rollers  14  and  15  and spurs  16  and  17  for pressing the recording medium against the sheet discharge rollers  14  and  15  are disposed downstream of the platen  10  in the feed direction of the recording medium. The sheet discharge rollers  14  and  15  are driven in synchronism with the feed roller  11  while the recording operation is carried out, whereby the recording medium is fed by the predetermined recording width. After the completion of the recording operation, the recording medium, onto which the images have been formed by the recording head  1 , is discharged to the outside of the recording apparatus by the sheet discharge rollers  14  and  15 . Each of the spurs  16  and  17  is a rotor having a multiplicity of sharp projections formed around the outer periphery thereof so that the extreme end of each projection comes into contact with the recording medium  201  in a minute area. 
     The recording medium  201  having been discharged from the recording apparatus by the sheet discharge rollers  14  and  15  and the spurs  16  and  17  is loaded on a discharged sheet tray unit  300  as a tray. Note that the discharged sheet tray unit  300  is composed of a discharged sheet tray  301  and a sub discharged sheet tray  302  so that a recording sheet which is long in the feed direction can be sufficiently loaded as shown in FIG. 1, and the sub discharged sheet tray  302  can be freely expanded and contracted in the feed direction of the recording medium with respect to the discharged sheet tray  301 . 
     Next, the arrangement of the discharged sheet tray unit  300  according to the present invention will be described with reference to FIGS. 3 to  7 . Side walls  303  and  304  are disposed to the ends of the discharged sheet tray  301  in the width direction thereof perpendicular to the feed direction of the recording medium, and swing shafts  305  and  306  are disposed to the side walls  303  and  304 , respectively. 
     U-shaped groove-like discharged sheet tray mounting sections (shaft receiving sections)  101  and  102 , which have openings  106  at the upper portions thereof, are disposed to the inner walls of the main body of the inkjet recording apparatus  100  in the width direction thereof perpendicular to the feed direction of the recording medium downwardly of the sheet discharge roller  15  and the spur  17 . 
     The swing shafts  305  and  306  of the discharged sheet tray unit  300  are fallen into the U-shaped grooves of the discharged sheet tray mounting sections  101  and  102  and engaged therewith. With this arrangement, the discharged sheet tray unit  300  is mounted on the inkjet recording apparatus  100  so as to swing with respect to the inkjet recording apparatus  100  about the centers of the swing shafts  305  and  306 . 
     When the discharged sheet tray unit  300  is in a state of use (FIGS. 1,  3  and  5 ), the position thereof at which it is used is determined in such a manner that the discharged sheet tray  301  is supported by the discharged sheet tray mounting sections  101  and  102  as well as the counterclockwise swing thereof is regulated by the upper surface  307  of the upstream end  308  of the discharged sheet tray  301  in the feed direction abutted against a stopper  300  disposed to the main body of the inkjet recording apparatus  100 . Further, the weight of the discharged sheet tray unit  300  can be supported as well as the weight of the recording mediums loaded on the discharged sheet tray unit  300  can be supported. 
     Next, operation performed when the discharged sheet tray unit  300  is made to a state of accommodation will be described. When the discharged sheet tray unit  300  is swung in the direction of an arrow B in FIGS. 3 and 5, the upstream end  308  of the discharged sheet tray  301  begins to be abutted against a convex section  104  as a regulating means disposed to the inkjet recording apparatus  100 . At the time, the discharged sheet tray unit  300  is pushed upward because the upstream end  308  is formed in a cam shape. As a result, the swing shafts  305  and  306  are guided by the U-shaped grooves of the discharged sheet tray mounting sections  101  and  102  so that the discharged sheet tray unit  300  can continue its swing motion while moving the center of swing thereof upward. When the discharged sheet tray unit  300  is further swung, the upstream end  308  gets over the convex section  104  and the state of the discharged sheet tray unit  300  shown in FIG. 6 is achieved. 
     In this state (FIG.  6 ), since the upstream end  308  gets over the convex section  104 , the discharged sheet tray unit  300  is moved downward again and the swing shafts  305  and  306  are also moved downward by being guided by the U-shaped grooves of the discharged sheet tray mounting sections  101  and  102 . At the time, since the upper cam surface  308   a  of the upstream end  308  is abutted against the downstream end surface  104   a  of the convex section  104  at an angle which is sufficient to support the weight of the discharged sheet tray unit  300 , the swing of the discharged sheet tray unit  300  is regulated by the convex section  104  so that the state of accommodation thereof can be kept. 
     A convex section  104  having a length covering the entire width of the discharged sheet tray unit  300  may be formed over the entire sheet discharge section of the recording apparatus main body. Otherwise, or one or a plurality of convex sections  104  may be formed at suitable positions of the recording apparatus main body in the width direction thereof. 
     When the discharged sheet tray unit  300  is shifted from the state of accommodation to the state of use, it is pushed down in the direction of an arrow C in FIG.  6 . With this operation, the upstream end  308  gets over the convex section  104  and the discharged sheet tray unit  300  can be swung because the swing thereof regulated by the convex section  104  is released, whereby the state of use of the discharged sheet tray unit  300  can be achieved (FIGS.  3  and  5 ). 
     When force is imposed on the discharged sheet tray unit  300  in the direction of the arrow C in FIG. 6 to shift it from the state of accommodation to the state of use, the discharged sheet tray unit  300  is lowered at the center in the width direction thereof and deformed concavely in a lower direction as a whole. At the time, the upstream end  308  is also lowered at the center thereof and more engaged with the convex section  104 . Thus, the upstream end  308  may not get over the convex section  104 . 
     To prevent the occurrence of this problem, a support section  105  is formed to the inkjet recording apparatus  100  as shown in FIG.  2 . Accordingly, even if the discharged sheet tray unit  300  is deformed, it is abutted against the a support section  105  to prevent the further deformation thereof. With this arrangement, the upstream end  308  can get over the convex section  104 . 
     The discharged sheet tray unit  300  is arranged detachably to reduce the size of the recording apparatus main body when it is transported or when it is packaged. Accordingly, guide surfaces  309  and  310  are formed on the side walls  303  and  304  so that the discharged sheet tray unit  300  can be reliably mounted on the inkjet recording apparatus  100 , that is, the discharged sheet tray unit  300  can be reliably mounted by being guided along the inside upper surface  107  of the inkjet recording apparatus  100 . 
     Note that the above embodiment is arranged such that the swing shafts are provided with the discharged sheet tray unit and the U-shaped mounting sections are formed to the recording apparatus main body. It is needless to say, however, that a similar effect can be obtained by an arrangement opposite to the above arrangement, that is, by an arrangement in which the swing shafts are provided with the recording apparatus main body and slot-shaped or U-shaped receiving sections, into which the swing shafts are loosely fitted, are formed on the discharged sheet tray unit. 
     It is sufficient for the swing shafts to move in the mounting sections (shaft receiving sections) in such a degree as to permit the end of the discharged sheet to get over the projection. Thus, the mounting sections may be formed in a circular shape or an oval shape without opening in addition to the U-shape so that the swing shafts can be loosely fitted thereinto. 
     In the above embodiment, the upstream end of the tray is formed in the cam shape and gets over the convex section. However, the cam surface may be formed on the convex section or both the upstream end and the projection may be formed in the cam shape. 
     Further, while the above embodiment is described as to the arrangement of the discharged sheet tray unit of the inkjet recording apparatus, the present invention is not limited thereto and can be embodied in the arrangement of a sheet tray of a recording apparatus employing other recording system or in the arrangement of a sheet tray of an image forming apparatus. That is, it is needless to say that the present invention can be embodied in the arrangement of, for example, a discharged sheet tray of a copying machine and a laser beam printer (LBP) and in the arrangement of a sheet feed tray on which recording sheets to be fed into an apparatus main body are loaded. Furthermore, the present invention can be also embodied in a sheet processing apparatus for binding the bundle of sheets using a stapler or the like or folding or punching sheets. 
     As described above, according to the present invention, there can be provided a sheet receiving apparatus having high reliability the cost of which is not increased because elastic parts such as metal springs or the like need not be added and elastically deformable sections also need not be formed and which has no possibility that the components thereof are deformed or broken. 
     While the present invention has been described with respect to what is currently considered to be the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.