JP2008222387A - Attachment member for sheet housing device, sheet housing device, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tray attachment capable of leveling the top surface of sheets partially different in thickness thereof independently of the number of housed sheets. <P>SOLUTION: This tray attachment 50 to be attached to a paper feeding cassette 6 housing conveyed sheets 18 can be attached so that a sheet ejecting direction side thereof is moved with a bottom plate 44 provided freely to move in the vertical direction comprises a support base 51a having a stacking part 51a-1, on which a range of the sheet 18 including one part on a tip side of the sheet 18 in the sheet ejecting direction is stacked at a position higher than the bottom plate 44, a flapper 52 provided to be fitted to the bottom plate 44 through the support base 51a and freely to move in the vertical direction and having a stacking section 52-1, on which a range of the sheet 18 including other parts of the sheet 18 on the tip side in the sheet ejecting direction is stacked, and a coil spring 53 for energizing the flapper 52 in the sheet 18 stacking direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mounting member for a sheet storage device, a sheet storage device, and an image forming apparatus.

  The image forming apparatus is provided with a paper feed cassette (sheet storage apparatus) that stores sheets such as paper used for image formation in the image forming apparatus.

  The paper feed cassette is provided with a bottom plate (bottom plate) provided so as to be movable in the vertical direction, and a raising mechanism for raising the bottom plate in the paper take-out direction (sheet take-out direction). When sheets are stacked on the bottom plate and mounted on the image forming apparatus, the bottom plate rises so that the uppermost sheet comes into contact with the pickup roll (sheet take-out means). Then, when the pickup roll is rotated, the uppermost sheet is taken out from the paper feed cassette to the image forming apparatus, and is sent to a conveyance path formed in the image forming apparatus.

  In such a paper feeding cassette, when a large number of sheets of different thickness are stacked on the bottom plate, such as a medicine bag or envelope with a hook, there is a difference in height between the hooked part and the non-hooked part. End up. For example, in a paper sheet with a crease at both ends (this type of paper has a thickness of 2 sheets at the center and 4 sheets at both ends), the height difference between the center part and both ends is doubled. And the center part is depressed.

  In FIG. 12, the lower end of the sheet upper surface restraint 136 provided in the image forming apparatus and the lower end of the pickup roll 135 are arranged substantially in a straight line. Therefore, when the paper cassette loaded with the paper 118 is loaded into the image forming apparatus, both ends of the paper 118 are pushed against the paper upper surface restraint 136 by the raised bottom plate 144 as shown in FIG. Although it is applied, the central portion that is not a heel does not hit the pickup roll 135, or even if it hits, a nip pressure sufficient to feed out the paper 118 cannot be obtained. Therefore, misfeed of the paper 118 occurs.

  It is also conceivable to flatten the upper surface of the paper by forming a step in the bottom plate to eliminate the above-described height difference. However, since the level of the height difference of the paper fluctuates depending on the number of stacked sheets, the fixed means such as the step of the bottom plate takes out the paper in the paper storage device for image formation and the stored number of paper fluctuates. In this case, it is inevitable that a height difference will occur.

For example, Japanese Patent Application Laid-Open No. 2006-103949 discloses a technique for forming an image on a sheet of paper having a partially different thickness accommodated in a sheet feeding cassette.
JP 2006-103949 A

  The present invention has been made from the above-described technical background, and is capable of flattening the upper surface of a sheet having a partially different thickness regardless of the number of sheets accommodated. An object is to provide an apparatus and an image forming apparatus.

  In order to solve the above-mentioned problem, the mounting member for a sheet storage device according to the first aspect of the present invention is a mounting member that is mounted on a sheet storage device that stores a conveyed sheet, and at least the sheet take-out direction side is vertically A support unit having a stacking unit that can be mounted so as to follow a bottom plate that is movably movable in a direction, and on which a region including a part of the front end side of the sheet in the sheet is stacked at a position higher than the bottom plate; The stack is mounted so as to be driven by the bottom plate and is movable in the stacking direction of the sheet and in the opposite direction thereof. And a biasing unit that applies a biasing force in the sheet stacking direction to the moving unit.

  According to a second aspect of the present invention, in the first aspect of the present invention, the moving means may be configured such that the loading portion of the moving means is on the same plane as the loading portion of the supporting means or more than the loading portion of the supporting means. The first moving end position, which is the moving end at the position displaced in the sheet stacking direction, and the position at which the stacking unit of the moving unit is displaced in the direction opposite to the sheet stacking direction from the stacking unit of the support unit. It moves between the second moving end position which is the moving end opposite to the first moving end position.

  A third aspect of the invention is characterized in that, in the first or second aspect of the invention, the moving means and the urging means can be integrally attached to the bottom plate.

  The invention according to claim 4 is the invention according to claim 3, wherein the moving means is attached with a gap formed in a direction intersecting the moving direction of the moving means. .

  The invention according to claim 5 is the invention according to claim 4, wherein the urging means is a coil spring, and one is provided at a central portion of the moving means.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the support means prevents the rear end side of the sheet in the sheet extraction direction from bending in a direction intersecting with the sheet extraction direction. It is characterized by being set to a possible length.

  According to a seventh aspect of the present invention, there is provided a sheet storage device according to the present invention, comprising the sheet storage device mounting member according to any one of the first to sixth aspects.

  The invention according to claim 8 is the sheet storage device according to claim 7, wherein the sheet storage device stores a recording sheet used for image formation, and the sheet storage device is an image formation device. The image forming apparatus is provided so as to be detachable.

  The invention according to claim 9 is the invention according to claim 8, wherein when the sheet storage device is mounted on the image forming apparatus, the support means is an uppermost portion stacked on the sheet storage device. It is attached to the position which opposes the sheet | seat taking-out means which takes out the sheet | seat located in this.

  According to a tenth aspect of the present invention, an image forming apparatus according to the present invention includes the sheet storage device according to the eighth or ninth aspect.

  According to the first aspect of the present invention, when the sheets are stacked on the sheet storage device, it is possible to flatten the upper surface of the sheets partially different in thickness regardless of the number of sheets stored.

  According to the second aspect of the present invention, it is possible to regulate the amount of movement of the moving means, and to flatten the upper surface of a sheet having a partially different thickness regardless of the number of stacked sheets.

  According to the third aspect of the present invention, the support means, the moving means, and the urging means are attached at the same time, so that the attachment time is reduced compared to the case where they are attached individually.

  According to the fourth aspect of the present invention, even when there is uneven thickness due to the location where the sheet is stacked on the sheet moving means becoming a boundary portion of the thickness, the moving means positioned on the lower surface of the sheet follows the uneven thickness. Therefore, the upper surface of the sheet can be surely flattened.

  According to the fifth aspect of the present invention, since the moving means is inclined with the coil spring as a fulcrum, the followability to the uneven thickness of the sheet is improved.

  According to the sixth aspect of the present invention, since the sheet take-out resistance caused by bending the rear end side of the sheet in a direction intersecting the sheet take-out direction is eliminated, the sheet can be taken out smoothly.

  According to the seventh aspect of the present invention, when the sheets are stacked on the sheet storage device, the upper surface of the sheet having a partially different thickness can be flattened regardless of the number of sheets stored. An apparatus can be provided.

  According to the eighth aspect of the invention, by flattening the upper surface of the partially different thickness sheet, the sheet can be stably conveyed to the image forming apparatus, and when the sheet is insufficient, The sheet can be replenished by being detached from the image forming apparatus.

  According to the ninth aspect of the present invention, since the sheet take-out means and the sheet are securely nipped on the support means, the nip pressure is stabilized.

  According to the tenth aspect of the present invention, it is possible to reliably take out the partially different thickness sheets stored in the sheet storage device from the sheet storage device and convey them to the image forming apparatus. Formation can be easily performed.

  Hereinafter, an embodiment as an example of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

  FIG. 1 is a conceptual diagram of a tandem full-color printer as an image forming apparatus according to an embodiment of the present invention. This full-color printer is configured to execute a printing operation based on image data sent from, for example, a personal computer or a scanner. Of course, the image forming apparatus may be configured as a copier or facsimile provided with a scanner, or a multifunction machine provided with these functions. Furthermore, a monochrome printer or a color printer other than a tandem type may be used.

  In FIG. 1, an image forming unit 2 is arranged in the vertical direction in a substantially central portion of a tandem type full-color printer main body 1. Further, inside the full-color printer main body 1, a transfer material onto which toner images of a plurality of colors formed by the image forming unit 2 are transferred is adsorbed to one side (left side in the case of illustration) of the image forming unit 2. A sheet conveying belt unit 3 that conveys the sheet in a state is disposed, and a control unit 4 including a control circuit or the like is provided on the other side of the image forming unit 2 (on the right side in the drawing). Power supply circuit units 5 each including a high voltage power supply circuit and the like are disposed obliquely above.

  In addition, a paper feed cassette (sheet accommodation device) 6 that accommodates and feeds paper 18 or the like as a sheet on which an image is transferred is disposed at the bottom of the full-color printer main body 1.

  The image forming unit 2 includes four image forming units 7Y, 7M, 7C, and 7K that form toner images of yellow (Y), magenta (M), cyan (C), and black (K) in order from the bottom. These four image forming units 7Y, 7M, 7C, and 7K are arranged in series at regular intervals along the vertical direction.

  These four image forming units 7Y, 7M, 7C, and 7K are configured in the same manner except for the color of the image to be formed, and roughly divided, as shown in FIG. 1, a photoconductor that rotates at a predetermined rotation speed. A drum 8, a charging roll 9 for primary charging that uniformly charges the surface of the photosensitive drum 8, and an image corresponding to each color are exposed on the surface of the photosensitive drum 8 to form an electrostatic latent image. An exposure device 10; a developing device 11 that develops the electrostatic latent image formed on the photosensitive drum 8 with toner of a corresponding color; and a cleaning device 12 that cleans transfer residual toner remaining on the photosensitive drum 8. The toner cartridge 13 supplies toner to the developing device 11.

  As shown in FIG. 1, the developing device 11 supplies the two-component or one-component developer housed therein to the developing roll 14 while stirring, and the layer thickness of the developer supplied to the developing roll 14. The electrostatic latent image formed on the surface of the photosensitive drum 8 is developed with toner of a predetermined color.

  The yellow (Y), magenta (M), cyan (C), and black (K) developing devices 11Y, 11M, 71C, and 17K corresponding to yellow (Y), magenta (M), cyan (C) C) and toner cartridges 13Y, 13M, 13C, and 13K as developer containers for supplying toner of each color of black (K).

  As shown in FIG. 1, the cleaning device 12 removes the transfer residual toner remaining on the surface of the photosensitive drum 8 by the cleaning blade 15, and transports the removed transfer residual toner into the cleaning device 12. It is designed to be accommodated.

  Further, as shown in FIG. 1, a control unit 4 is disposed inside the full-color printer main body 1. The control unit 4 includes, for example, an image processing apparatus that performs predetermined image processing on image data. 16 is provided. The image processing device 16 sequentially outputs image data of each color of yellow (Y), magenta (M), cyan (C), and black (K) to the exposure device 10, and the exposure device 10 according to the image data. The four laser beams LB emitted in this manner are scanned and exposed on the respective photosensitive drums 8Y, 8M, 8C, and 8K to form electrostatic latent images. Each photosensitive drum 8Y. The electrostatic latent images formed on 8M, 8C, and 8K are converted into yellow (Y), magenta (M), cyan (C), and black (K) colors by developing devices 11Y, 11M, 11C, and 11K, respectively. Developed as a toner image.

  Further, as shown in FIG. 1, the sheet conveying belt unit 3 includes a sheet conveying belt 17 that circulates and moves as an endless belt, and the sheet conveying belt 17 includes the image forming units 7Y, 7M, and 7C. , Transported in a state of electrostatically adsorbing paper 18 as a transfer material onto which toner images of each color of yellow (Y), magenta (M), cyan (C), and black (K) formed at 7K are transferred. Is configured to do.

  As shown in FIG. 1, the paper transport belt 17 is stretched with a predetermined tension between a drive roll 19 and a driven roll 20 as stretch rolls arranged along the vertical direction. A drive roll 19 rotated by a motor is configured to circulate counterclockwise at a predetermined speed in FIG.

  For example, the distance between the drive roll 19 and the driven roll 20 is set to a length substantially equal to the length of the A3 size paper 18, but is not limited thereto, and may be set arbitrarily. As the paper transport belt 17, for example, a flexible synthetic resin film such as polyimide is formed in an endless belt shape.

  Further, as shown in FIG. 1, an attracting roll 22 for electrostatically attracting the paper 18 to the surface of the paper transport belt 17 is brought into contact with the surface of the drive roll 19 via the paper transport belt 17. Is arranged. The suction roll 22 is configured, for example, by covering the surface of a metal cored bar with conductive rubber in the same manner as the charging rolls 9 of the image forming units 7Y, 7M, 7C, and 7K. A predetermined bias voltage for adsorption is applied. The suction roll 22 is configured to electrostatically charge the paper 18 sent from the paper feed cassette 6 and suck the paper 18 on the surface of the paper transport belt 17. Note that the suction roll 22 is not necessarily provided.

  Toner of each color of yellow (Y), magenta (M), cyan (C), and black (K) formed on the photosensitive drums 8Y, 8M, 8C, and 8K of the image forming units 7Y, 7M, 7C, and 7K As shown in FIG. 1, the images are sequentially transferred in multiple layers onto the sheet 18 conveyed while being attracted to the surface of the sheet conveying belt 17 while being superimposed on each other by the transfer rolls 23Y, 23M, 23C, and 23K. Is done. The transfer rolls 23Y, 23M, 23C, and 23K are integrally attached to the paper transport belt unit 3.

  As shown in FIG. 1, the paper 18 is fed from a paper feed cassette 6 disposed at the bottom of the printer main body 1 and conveyed to the printer main body 1. The paper feed cassette 6 includes a paper tray 24 in which paper 18 having a desired size and material is accommodated. Further, a pickup roll (sheet take-out means) 35 that nips the uppermost sheet 18 is disposed immediately above the sheet tray 24. As a result, the paper 18 of a desired size and material is taken out from the paper tray 24 one by one by the pickup roll 35 and fed by the feeding roll 25 and separated one by one by the separating roll 26. The sheet is fed in a state, and is conveyed to a suction position on the sheet conveying belt 17 at a predetermined timing via a registration roll 27 as a sheet feeding unit.

  The feeding roll 25 and the pickup roll 35 are provided on the full color printer main body 1 side, and the separating roll 26 is provided on the paper feeding cassette 6 side. Details of the paper feed cassette 6 will be described later.

  Here, a roll that combines the function of the pickup roll 35 and the function of the feeding roll 25 may be used. Further, instead of the separating roll 26, a pad type separating means having a predetermined friction resistance with respect to the paper 18 to be taken out may be used.

  The sheet is a sheet-like member, for example, various sizes such as A4 size, A3 size, B5 size, B4 size, and various materials such as thick paper such as plain paper and coated paper, and OHP sheets In addition, various forms such as a medicine bag with a hook and an envelope are used.

  As shown in FIG. 1, the paper 18 on which the toner images of each color of yellow (Y), magenta (M), cyan (C), and black (K) are transferred in a multiple manner has a rigidity ( After being separated from the paper transport belt 17 by so-called stiffness, the paper is transported along the transport path 28 to the fixing device 29. The fixing device 29 applies heat and pressure to the paper 18 to fix the toner image on the paper 18.

  The paper transport belt 17 and the fixing device 29 are arranged close to each other, and the paper 18 separated from the paper transport belt 17 is transported to the fixing device 29 by the transport force of the paper transport belt 17. The fixing device 29 is rotationally driven in a state in which the heating roll 30 and the pressure belt 31 are in pressure contact with each other, and the sheet 18 is passed through a nip portion formed between the heating roll 30 and the pressure belt 31. The fixing process is performed by heat and pressure.

  Thereafter, the paper 18 on which the toner images of the respective colors are fixed is discharged by the discharge roll 32 with the print surface down on the discharge tray 33 provided on the upper part of the full-color printer main body 1, and the printing operation is completed. .

  Note that a full-color printer can print an image of a desired color such as monochrome as well as a full-color image. Depending on the color of the image to be printed, yellow (Y), magenta (M), A toner image is formed by all or part of the cyan (C) and black (K) image forming units 7Y, 7M, 7C, and 7K.

  In FIG. 1, reference numeral 34 denotes an operation panel provided with a display unit such as a liquid crystal panel attached to the front of the printer main body 1. The operation panel 34 displays the status of the printer and is necessary. It is configured to perform operations and the like.

  Next, the paper feed cassette provided in the image forming apparatus according to the present embodiment will be described.

  Here, FIG. 2 is a perspective view showing a paper feed cassette according to an embodiment of the present invention with the flapper raised, FIG. 3 is a cross-sectional view taken along the line AA 'in FIG. 2, and FIG. FIG. 5 is a perspective view showing a paper feed cassette according to an embodiment of the invention with a flapper lowered, FIG. 5 is a cross-sectional view taken along line BB ′ of FIG. 4, and FIG. 6 is a tray attached to the paper feed cassette. FIG. 7 is a perspective view showing an example of the movement of the flapper constituting the tray attachment attached to the paper feed cassette.

  As shown in FIGS. 2 to 5, the paper feed cassette 6 includes the paper tray 24 described above, a front cover 41 that is operated when the paper feed cassette 6 is detached from the full-color printer body 1, the paper tray 24, and the front There is provided a roll casing 42 which is positioned between the cover 41 and the roll 26 is disposed, and these are integrally formed with each other.

  As shown in FIGS. 2 and 4, the front cover 41 has a wider width than the roll casing 42 and the paper tray 24, and both ends slightly wrap around the side according to the shape of the full-color printer main body 1. It is curved. As shown in FIGS. 3 and 5, at the center of the front cover 41, when the paper feed cassette 6 is pulled out from the full-color printer main body 1, a handle portion is a space in which an operator inserts a finger from below to above. 41a is formed.

  2 and 4, the roll casing 42 is pressed against and fed to a feed roll 25 that is rotationally driven in a direction in which the paper 18 is fed into the full-color printer main body 1 by a rotation driving means (not shown). A separating roll 26 driven to rotate by the feed roll 25 is attached at a position facing the feed roll 25 when the paper feed cassette 6 is mounted on the printer main body 1. The two rolls 26 are provided coaxially with each other and are arranged at the approximate center in the width direction of the roll casing 42. Then, the shaft-coupled torque limiter 43 provides a rotation prevention force (that is, a force that prevents the driven rotation) below the rotational force of the feeding roll 25.

  When the pickup roll 35 is rotationally driven as described above, the uppermost paper 18 accommodated in the paper tray 24 is taken out and reaches between the feeding roll 25 and the separating roll 26.

  At this time, if a plurality of sheets 18 including the uppermost sheet 18 have been taken out, the uppermost sheet 18 is sandwiched between the feeding roll 25 and the separating roll 26 by the feeding roll 25 and the printer main body. 1, but the other papers 18 are rolled one by one by being prevented from being moved forward by the roll 26 to which the rotation preventing force is applied. This prevents double feeding. If only the uppermost sheet 18 has been sent, the rotational force of the feed roll 25 exceeding the rotation prevention force applied by the torque limiter 43 is transmitted to the separating roll 26 via the sheet 18. Therefore, the separating roll 26 is driven to rotate against the rotation blocking force from the torque limiter 43 and the paper 18 moves into the printer main body 1.

  As shown in FIGS. 2 to 5, a bottom plate (bottom plate) 44 that receives a weight load of the stored paper 18 is provided on the bottom surface of the paper tray 24. A guide pin 45 is attached to the front end of the bottom plate 44 in the sheet take-out direction (sheet take-out direction) D so as to face outward. Further, long holes 24a through which the guide pins 45 penetrate with a gap are formed in the side walls facing each other on the roll casing 42 side of the paper tray 24 so as to extend linearly in the vertical direction. Further, a coil spring 46 is disposed between two positions on the front end side of the bottom plate 44 in the paper transport direction D and the bottom surface of the paper tray 24, and applies an upward spring force to the bottom plate 44. .

  Thereby, in a state where the paper 18 is not stored in the paper tray 24 (no load state), the bottom plate 44 is lifted forward in the paper take-out direction D by the spring force of the coil spring 46. At this time, since the guide pin attached to the bottom plate 44 moves upward in the long hole 24a, the bottom plate 44 rises so that the leading end in the paper take-out direction D draws a linear movement locus, The guide pin 45 stops at a position where it hits the upper end of the long hole 24a. Therefore, by the movement of the front end of the bottom plate 44, the rear end of the paper extraction direction D of the bottom plate 44 moves so as to slide the bottom surface of the paper tray 24 toward the front end.

  On the other hand, in a state where the paper 18 is stored in the paper tray 24, the spring force of the coil spring 46 loses the weight of the paper 18, so that the bottom plate 44 has a front side in the paper take-out direction D of the weight of the paper 18. It descends by the amount corresponding to that. If a large amount of paper 18 is accommodated in the paper tray 24 and the spring force of the coil spring 46 is completely lost to the weight of the paper 18, the bottom plate 44 is positioned closest to the bottom surface of the paper tray 24. It becomes.

  The movement of the bottom plate 44 at this time follows the reverse of the movement to the no-load state described above. That is, when the guide pin 45 is guided through the long hole 24 a, the front end in the paper take-out direction D descends so as to draw a linear movement locus, and the rear end retreats so as to slide on the bottom surface of the paper tray 24. To do.

  In the present embodiment, the bottom plate 44 is movable in the vertical direction on the front side in the paper take-out direction D by the coil spring 46, but the entire bottom plate 44 may be movable in the vertical direction. Further, although the bottom plate 44 is lifted by the coil spring 46, it may be lifted by a force other than the spring force such as a motor.

  On the bottom surface of the paper tray 24, a pair of side fences 47 that approach and separate from each other in synchronization with each other in the width direction slide on guide rails 24c formed along the width direction on the bottom surface of the paper tray 24. It has been fitted. A back fence 48 that approaches and separates from the forward fence 49 that is the inner wall at the front end of the paper tray 24 in the paper ejection direction D is disposed at the rear end side of the paper tray 24 in the length direction on the bottom surface of the paper tray 24. A guide rail 24b formed along the guide rail 24b is slidably fitted. The bottom plate 44 is surrounded by the fences 47, 48, and 49.

  The side fence 47 and the back fence 48 are provided with fixing levers 47a and 48a that fit into locking grooves (not shown) continuously formed on the bottom surface of the tray along the moving direction of the fences 47 and 48. Therefore, the side fence 47 and the back fence 48 are moved in a state where the fitting of the fixing levers 47a and 48a into the locking grooves is released, and these are adjusted to the size and orientation of the paper 18 accommodated in the paper tray 24, and then fixed. By fitting the levers 47a and 48a into the locking grooves, the fences 47 and 48 are fixed at the positions. As a result, the paper 18 is regulated at a predetermined stacking position of the paper tray 24 and is accommodated on the bottom plate 44.

  As shown in the figure, a tray attachment (sheet storage device mounting member) 50 is attached to the bottom plate 44 so as to follow the movement of the bottom plate 44 described above.

  As shown in detail in FIG. 6, the tray attachment 50 includes an upper plate 51 and a flapper (moving means) 52. The upper plate 51 includes a support base (support means) 51a that is positioned at the center and has a stacking portion 51a-1 that is an upper surface on which the sheets 18 are stacked, and bases 51b that are positioned on both sides of the support base 51a. The base 51b has a lower height than the support base 51a and is integrally formed with the support base 51a. And it is attached to the bottom plate 44 so that the longitudinal direction of the support base 51a is along the paper take-out direction D.

  Fixing pieces 51b-2 are formed at four locations on the base 51b downward. These fixing pieces 51b-2 are respectively engaged with four corners formed on the bottom plate 44, thereby restricting the free movement of the tray attachment 50 in the plane direction of the bottom plate 44, and the tray attachment. A substantially central portion of 50 is fixed to the bottom plate 44 with screws. The attachment of the tray attachment 50 is not limited to this structure, and various other attachment structures can be employed.

  In the tray attachment 50, when the paper feed cassette 6 is mounted on the full-color printer main body 1, the support base 51a of the upper plate 51 is positioned so as to face the pickup roll 35 described above. When the feeding roll 25 is configured to pick up a sheet by directly contacting the top surface of the loaded user 18 (when the feeding roll 25 is used as a sheet take-out means), it faces the feeding roll 25. What is necessary is just to comprise so that the support stand 51 may be located in the done position.

  The flapper 52 is attached to the base 51b so as to sandwich the front end of the support base 51a in the sheet take-out direction D, and has a stacking unit 52-1, which is an upper surface on which the sheets 18 are stacked. As shown in the drawing, mounting holes 51b-1 are formed to open upward at two positions in the paper take-out direction D of the base 51b, and the flapper 52 is inserted into such mounting holes 51b-1. Thus, it is movable in the vertical direction (that is, in the stacking direction of the paper 18 and the opposite direction).

  A claw portion 52a is formed on the side of the flapper 52 so as to face outward. In addition, on both sides of each mounting hole 51b-1, guide grooves 51b-2 into which the claw portions 52a of the flapper 52 are fitted are formed long in the vertical direction with a closed shape at the upper end. Accordingly, the flapper 52 moves up and down so that the claw portion 52a moves in the guide groove 51b-1, and further increases with the upper end of the guide groove 51b-1 as the first moving end position, that is, Detachment from the mounting hole 51b-1 is prevented. Further, since the flapper 52 is attached to the base 51b, the position where the flapper 52 descends and hits the base 51b becomes the second moving end position which is the moving end opposite to the first moving end position. . Accordingly, the flapper 52 moves between the first moving end position and the second moving end position.

  The flapper 52 is set so that the stacking portion 52-1 is flush with the stacking portion 51a-1 of the support base 51a of the upper plate 51 at the first moving end position. However, the two loading portions 51a-1 and 52-1 do not necessarily have to be on the same plane at the first moving end position, but the loading portion 52-1 of the flapper 52 is not the loading portion of the support base 51a. If it is on the same plane as 51a-1 or higher than that, it is advantageous when a pickup roll 35 and a sheet upper surface restraint (sheet upper surface restraint) 36 are brought into contact with the paper 18 described later.

  Each of the flappers 52 and a portion of the base 51b located below the flapper 52 are provided with coil springs (attaching force) that apply a spring force (biasing force) in the upward direction (that is, the stacking direction of the paper 18) to the flapper 52. Force means) 53 is mounted. The spring force of the coil spring 53 is set so as to lose against the loaded weight of the paper 18. Therefore, the flapper 52 is in the first moving end position by the spring force of the coil spring 53 when the paper 18 is not stacked. Further, when the sheets 18 are stacked, the spring force of the coil spring 53 loses the load, and the flapper 52 gradually descends to finally reach the second moving end position depending on the load.

  The flapper 52 is inserted into the mounting hole 51b-1 so as to have play. That is, the flapper 52 is attached to the base 51 b of the upper plate 51 with a gap formed in the lateral direction that intersects the vertical direction that is the moving direction. Thereby, as shown in FIG. 7, the flapper 52 can be inclined.

  Here, in the present embodiment, there is one coil spring 53 between the flapper 52 and the base 51 b at the center of the flapper 52. Therefore, the flapper 52 is inclined with the single coil spring 53 located at the center as a fulcrum, and can be inclined smoothly in all directions (that is, before and after the sheet take-out direction D and left and right). However, a plurality of coil springs 53 may be mounted, and as a biasing means for applying a biasing force to the flapper 52, a coil spring other than the coil spring may be used.

  Further, as described above, in the present embodiment, the flapper 52 is attached to the upper plate 51 provided with the support base 51a, and the coil spring 53 is mounted between the flapper 52 and the upper plate 51, thereby supporting the flapper 52. The base 51a, the flapper 52, and the coil spring 53 are unitized. Therefore, the support base 51a, the flapper 52, and the coil spring 53 can be attached simultaneously (integrally) by simply attaching the upper plate 51 to the paper feed cassette 6 (the bottom plate 44 provided on the paper tray 24). Compared with the case where these are attached individually, attachment can be performed in a short time. However, these may be individually attached without being unitized.

  Further, as in the present embodiment, the flapper 52 is not attached to the bottom plate 44 via the upper plate 51, but the flapper is attached to the bottom plate and the upper plate is attached to the flapper. It may be attached to the bottom plate via a flapper.

  Furthermore, in this embodiment, the tray attachment 50 is attached to the bottom plate 44 so as to be driven by the bottom plate 44. However, as long as the tray attachment 50 is driven by the bottom plate 44, other attachments are possible. It may be a structure. As an example, an attachment structure in which the tray attachment 50 is attached to the bottom plate 44 such as the bottom surface of the paper tray 24 and placed on the bottom plate 44 may be used.

  Now, since the paper 18 is regulated by the fences 47, 48, and 49 and accommodated on the bottom plate 44, and the tray attachment 50 is attached on the bottom plate 44, the paper 18 is loaded on the tray attachment 50. Will be. The tray attachment 50 is attached to the base 51b so that the longitudinal direction of the support base 51a formed on the upper plate 51 is along the paper take-out direction D, and the flapper 52 is sandwiched between the tips of the support stand 51a in the paper take-off direction D. Therefore, the sheet 18 is loaded on the stacking portion 51a-1 of the support base 51a of the upper plate 51 in the area extending from the center of the front end side in the paper takeout direction D, and on the front end side in the paper takeout direction D. An area other than the area loaded on the support base 51 a is loaded on the loading section 52-1 of the flapper 52.

  The support base 51a and the flapper 52 of the upper plate 51 only need to be able to stack the leading end side of the sheet 18 in the sheet take-out direction D on the stacking portions 51a-1 and 52-1, respectively. An area extending a predetermined length from the front end side in the paper take-out direction D may not be stacked on the support base 51a. However, it is preferable that the support base 51a has a length that can prevent the rear end side of the paper take-out direction D of the paper 18 from bending in a direction intersecting the paper take-out direction D. More specifically, the support base 51a may have a length that is ½ or more, preferably 2/3 or more of the maximum length of the paper 18 that is accommodated. When the support base 51a has such a length, the take-out resistance of the paper 18 due to bending of the rear end side of the paper 18 in the direction intersecting the paper take-out direction D is eliminated, so that the paper 18 can be smoothly taken out. Because.

  Next, a description will be given of a case where the paper cassette 6 having the above-described configuration accommodates paper 18 having both edges as an example of paper having partially different thicknesses and is attached to the full-color printer main body 1.

  Here, FIG. 8 is an explanatory view showing the bottom plate and the tray attachment of the paper feed cassette in a state in which no paper is stacked, from the front in the paper take-out direction, and FIG. FIG. 10 is an explanatory view showing the tray attachment from the front in the paper take-out direction, FIG. 10 is an explanatory view showing a state where the paper feeding cassette full of paper is mounted on the full-color printer body, and FIG. FIG. 6 is an explanatory diagram showing a state in which the paper feeding cassette is attached to the full-color printer main body.

  As shown in FIG. 8, the flapper 52 is positioned at the first moving end position by the spring force of the coil spring 53 in a state where the sheets are not stacked, and the stacking portion 52-1 is located on the upper plate 51. It is on the same plane as the stacking portion 51a-1 of the support base 51a.

  When the paper 18 with both ends thereof is tacked from the state shown in FIG. 8, the flapper 52 receives the load of the paper spring 18 loaded on the stacking unit 52-1 of the flapper 52. The spring force is lost, and the flapper 52 gradually descends and finally sinks to the second moving end position depending on the load. On the other hand, in the support base 51a of the upper plate 51, even if the paper 18 is stacked on the stacking portion 51a-1 of the support base 51a, there is no sinking unlike the flapper 52. When the thickness of the sheet bundle at the central portion that is not the ridge is 20 mm and the thickness of the sheet bundle 18 at the ridge portion at both ends is 40 mm, the flapper is formed at the leading edge in the sheet conveyance direction D as shown in FIG. Since the portion 52 is submerged by 20 mm and the portion that is not a ridge is supported by the support base 51a and does not sink, the upper surface of the sheet bundle 18 does not swell on both sides by the thickness of the ridge, but slightly swells. Stay.

  In the present embodiment, the flapper 52 is completely buried in the base 51b at the second moving end position, but a part of the flapper 52 may protrude. Of course, it is not necessary to stack the sheets 18 until the flapper 52 reaches the second moving end position.

  When the paper feed cassette 6 is inserted into the full-color printer main body 1 in the stacked state shown in FIG. 9, the front side of the bottom plate 44 in the paper take-off direction D is raised by the spring force of the coil spring 46 to lift the paper bundle 18. Here, in FIG. 10, the lower end of the sheet upper surface holder 36 provided above the paper feed set mounting portion (not shown) of the full-color printer main body 1 and the lower end of the pickup roll 35 are arranged in a substantially linear relationship. Has been. Accordingly, as shown in the figure, the raised sheet bundle 18 abuts against the lower end of the sheet upper surface restraint 36 and the lower end of the pickup roll 35 and the upper surface thereof is flattened.

  As a result, a sufficient nip pressure can be obtained between the uppermost sheet 18 and the pickup roll 35 for taking it out and introducing it into the conveyance path of the full-color printer body 1. 18 is reliably removed from the paper feed cassette 6.

  When the uppermost sheet 18 is taken out from the sheet feeding cassette 6 one by one and the thickness of the sheet bundle 18 is reduced and the weight is gradually reduced, the sheet 18 in the sheet take-out direction D of the bottom plate 44 is reduced. The front side is further raised by the spring force of the coil spring 46, and the force of pushing the flapper 52 against the spring force of the coil spring 53 by the sheet bundle 18 is gradually weakened. Therefore, as shown in FIG. 11, the sheet bundle 18 always abuts on the pickup roll 35 at a portion that is not the bag loaded on the loading portion 51 a-1 of the support base 51 a of the upper plate 51, and the loading portion of the flapper 52. The eaves portion stacked on 52-1 always abuts against the sheet upper surface restraint 36. Therefore, regardless of the number of sheets 18 stacked (that is, whether the sheets 18 are fully loaded or one sheet), the upper surface of the sheet bundle 18 is kept flat and is positioned at the top. The attached paper 18 is reliably taken out from the paper feed cassette 6 by the pickup roll 35.

  Here, a case has been described in which a paper 18 with double-sided flanges is targeted for storage as an example of a paper having a partially different thickness. For example, from the end (the end in the direction perpendicular to the paper take-out direction D). The present invention can be applied to image formation on various papers that are partially different in thickness, such as paper that is folded by a predetermined width. Of course, the present invention can also be applied to a sheet having no wrinkles such as a single sheet.

  As described above, when the paper 18 having a partially different thickness is accommodated in the paper feed cassette 6 to which the tray attachment 50 is attached, the thin portion is stacked on the support base 51a of the upper plate 51. If the thick part is stacked on the flapper 52, the spring force of the coil spring 53 is lost by the weight of the paper 18 in the thick part, and the flapper 52 is lowered. Thus, when the paper feed cassette 6 is mounted on the full-color printer main body 1, the upper surface is flattened regardless of the number of sheets 18 accommodated, so that the space between the uppermost sheet 18 and the pickup roll 35 is A sufficient nip pressure can be obtained, and the paper 18 can be reliably picked up from the paper feed cassette 6 and sent to the conveyance path of the printer main body 1.

  Further, since the stacking portion 52-1 of the flapper 52 is on the same plane as the stacking portion 51a-1 of the support base 51a at the first moving end position, the sheet 18 is picked up even if the number of sheets is reduced. 35 and the sheet upper surface restraint 36 can be reliably brought into contact with each other.

  Furthermore, as described above, the flapper 52 is inclined by being attached to the base 51b of the upper plate 51 with a gap formed in the lateral direction, so that the portion of the paper 18 stacked on the flapper 52 has a thickness. Even when there is uneven thickness due to the boundary portion or the like, the flapper 52 positioned on the lower surface of the paper 18 is inclined following the uneven thickness, so that the upper surface of the paper 18 is reliably flattened.

  At this time, if a single coil spring 53 is provided in the central portion of the flapper 52 as an urging means for the flapper 52, the flapper 52 can be smoothly inclined regardless of front and rear, left and right. The follow-up performance to is improved.

  As described above, the support base 51a of the upper plate 51 is attached at a position facing the pickup roll 35 when the paper feed cassette 6 is attached to the full-color printer body 1, and therefore the pickup roll 35, the paper 18, and the like. Is necessarily nipped on the support base 51a, and the nip pressure is stabilized.

  In the present embodiment, the support base 51a of the upper plate 51 is located in the center and the flappers 52 are located on both sides. However, the positional relationship between the support base 51a and the flapper 52 is the same as that of the above embodiment. It is not limited to. That is, the support base may be arranged on one side in the width direction of the paper tray 24 and the flapper as the moving means may be arranged on the other side. However, regardless of the position, the support table is positioned so as to face the pickup roll 35 when the paper feed cassette 6 is mounted on the printer body 1 as in the present embodiment. Good.

  Then, the image forming apparatus such as the full-color printer main body 1 includes the paper feed cassette 6 having the above-described configuration, so that the papers 18 partially different in thickness accommodated in the paper feed cassette 6 can be reliably fed into the transport path. Therefore, it is possible to easily perform image formation on the paper 18 having partially different thicknesses.

  In the above description, the case where the present invention is mounted on an image forming apparatus that records toner is shown. However, the present invention is not limited to the image forming apparatus, and a sheet storage apparatus that partially stores sheets having different thicknesses, For example, the present invention can be applied to various apparatuses such as an ink jet type image forming apparatus that records with discharged ink and an ATM (automatic cash deposit / dispense machine).

1 is a conceptual diagram illustrating a tandem type full-color printer as an image forming apparatus according to an embodiment of the present invention. It is a perspective view which shows the paper feed cassette which concerns on one embodiment of this invention in the state which the flapper raised. FIG. 3 is a cross-sectional view taken along line A-A ′ of FIG. 2. It is a perspective view which shows the paper feed cassette which concerns on one embodiment of this invention in the state which the flapper fell. FIG. 5 is a cross-sectional view taken along line B-B ′ of FIG. 4. It is a perspective view which shows the tray attachment attached to the paper feed cassette. It is a perspective view showing an example of movement of a flapper which constitutes a tray attachment attached to a paper feed cassette. FIG. 4 is an explanatory diagram showing a bottom plate and a tray attachment of a paper feeding cassette in a state in which no paper is stacked from the front in the paper take-out direction. FIG. 4 is an explanatory diagram showing a bottom plate and a tray attachment of a paper feeding cassette full of paper from the front in the paper take-out direction. FIG. 4 is an explanatory diagram illustrating a state where a paper feeding cassette full of paper is mounted on a full-color printer main body. FIG. 6 is an explanatory diagram illustrating a state where a paper feeding cassette from which a predetermined number of sheets have been taken out from a full load is mounted on the full color printer main body. FIG. 10 is an explanatory diagram illustrating a state in which a sheet with a flange is accommodated in a sheet feeding cassette provided in a conventional image forming apparatus.

Explanation of symbols

1 Full color printer (image forming device)
6 Paper cassette (sheet storage device)
18 Paper, paper bundle (sheet)
24 Paper tray 25 Feed roll 35 Pickup roll (sheet take-out means)
36 Paper top side restraint (sheet top face restraint)
44 Bottom plate
50 Tray attachment (attachment member for sheet storage device)
51 Upper plate 51a Support base (support means)
51a-1 Loading section 51b Base 52 Flapper (moving means)
52-1 Loading part 53 Coil spring (biasing means)

Claims (10)

An attachment member attached to a sheet storage device in which a sheet to be conveyed is stored,
At least the sheet take-out direction side can be mounted so as to follow a bottom plate provided so as to be movable in the vertical direction, and the stack includes a region including a part of the sheet in the sheet take-out direction at a position above the bottom plate. A support means having a portion;
A stacking unit that can be mounted so as to follow the bottom plate and that is movable in the stacking direction of the sheet and in the opposite direction thereof, and stacks an area including the other part of the sheet in the sheet take-out direction. A moving means comprising:
Urging means for applying an urging force in the sheet stacking direction to the moving means;
A mounting member for a sheet storage device, comprising: The moving means is
A first moving end position serving as a moving end at a position where the stacking unit of the moving unit is displaced in the same plane as the stacking unit of the support unit or in the sheet stacking direction from the stacking unit of the support unit;
A second moving end position serving as a moving end opposite to the first moving end position at a position where the stacking portion of the moving means is displaced in a direction opposite to the sheet stacking direction with respect to the stacking portion of the support means; ,
Move between,
The mounting member for a sheet storage device according to claim 1. The support means, the moving means and the biasing means can be integrally attached to the bottom plate,
The attachment member for a sheet storage device according to claim 1, wherein the attachment member is a sheet storage device. The moving means is
It is attached with a gap formed in a direction intersecting the moving direction of the moving means,
The mounting member for a sheet storage device according to claim 3. The biasing means is a coil spring, and one is provided at the center of the moving means.
The mounting member for a sheet storage device according to claim 4. The support means is set to a length that can prevent the rear end side of the sheet in the sheet extraction direction from bending in the direction intersecting the sheet extraction direction.
The mounting member for a sheet storage device according to any one of claims 1 to 5.   A sheet storage device comprising the attachment member for a sheet storage device according to any one of claims 1 to 6.   The sheet storage device is a sheet storage device for storing a recording sheet used for image formation, and the sheet storage device is detachably provided in an image forming apparatus in which image formation is performed. Item 8. The sheet storage device according to Item 7. When the sheet storage device is attached to the image forming apparatus,
The support means is attached to a position facing the sheet take-out means for taking out the sheet located at the uppermost portion stacked on the sheet storage device.
The sheet storage device according to claim 8.   An image forming apparatus comprising the sheet storage device according to claim 8.

Images