JP2011068477A - Sheet carrying mechanism and image forming device incorporated with sheet carrying mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet carrying mechanism and an image forming device incorporated with this sheet carrying mechanism, for reducing a defective percent of separating a sheet. <P>SOLUTION: This sheet carrying mechanism includes a sheet storage part for storing a sheet bundle T prepared by layering a plurality of sheets S, a carrying element 630 for taking out and carrying the sheets from the sheet bundle, and an air sending mechanism 640 having an air sending port for blowing off gas toward a side surface SS of the sheet bundle T in the carrying direction of the sheets S. The air sending port includes an upstream air sending port 643 arranged on the upstream side in the carrying direction, a downstream air sending port 644 arranged on the downstream side in the carrying direction, and a main air sending port 645 arranged between the upstream air sending port 643 and the downstream air sending port 644. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sheet conveying mechanism that accommodates and conveys a sheet, and an image forming apparatus incorporating the sheet conveying mechanism.

  In general, an image forming apparatus typified by a copier, a printer, a facsimile, or a multifunction machine having these functions uses a sheet of high-quality paper or copy paper. The printing processing surface of such a commonly used sheet is usually not subjected to processing for improving the smoothness of the processing surface. Therefore, in general, a high adhesion force between the sheets that causes inconvenience in taking out and conveying the sheets does not occur.

  In recent years, with the development of colorization technology for image forming apparatuses, there are increasing opportunities to use coated paper having high whiteness and gloss. A coating for improving whiteness and gloss is generally applied to both sides or one side of the coated paper. The application of this paint increases not only the whiteness and gloss, but also the smoothness of the printing surface of the sheet. The improvement in the smoothness of the print processing surface of the sheet increases the adhesion between the stacked sheets. For this reason, when it is going to convey a sheet | seat from the accommodating part which accommodates the laminated | stacked sheet | seat, due to the high contact | adhesion force between sheets, the problem that a several sheet is taken out and conveyed will arise.

  In addition to coated paper, there are increasing opportunities for various types of sheets such as film sheets and tracing paper to be used in image forming apparatuses. Film sheets and tracing paper also have a very smooth treated surface like coated paper. Accordingly, film sheets and tracing paper also cause the inconvenience that a plurality of overlapping sheets are transported, similarly to coated paper.

  The outer peripheral surface of the sheet bundle including a plurality of stacked sheets is in direct contact with the outside air. For this reason, the outer peripheral surface of the sheet bundle absorbs moisture from the outside air as compared to the inside of the sheet bundle (a portion that does not directly contact outside air). For this reason, the upper surface of the sheet bundle and the peripheral surface of the sheet bundle swell compared to other portions. As a result, a very thin space generated between the sheets becomes a negative pressure, and adhesion between adjacent sheets is generated. This further exacerbates the inconvenience that a plurality of overlapping sheets are conveyed.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a sheet feeding device including an air feeding mechanism that blows gas from the side of a sheet bundle. In this disclosed technique, the central portion of the sheet to be fed out from the sheet feeding device is pressed by blowing air into the side surface of the sheet bundle between the upstream edge and the downstream edge while holding the upstream edge and the downstream edge of the sheet bundle. The purpose is to lift and release the adhesion between the sheets.

JP-A-4-23747

  As described above, the adhesion between the stacked sheets is caused by factors such as the smoothness of the processed surfaces of the sheets and the swelling of the outer peripheral surface of the sheet bundle, and thus the adhesion between the sheets varies due to variations in these factors. For this reason, when the adhesive force is extremely high between the edge portions of the sheet to which the air from the air supply port of the sheet feeding device disclosed in Patent Document 1 is blown, separation of the sheets cannot be suitably performed. This causes inconvenience. Although it is possible to increase the air volume, the increase in the air volume may cause inconvenience in other processes such as sheet conveyance.

  The problems as described above are common not only to the image forming apparatus but also to other processes for handling the sheet material.

  SUMMARY An advantage of some aspects of the invention is that it provides a sheet conveying mechanism that reduces a defective rate related to sheet separation and an image forming apparatus incorporating the sheet conveying mechanism. To do.

  A sheet transport mechanism according to one aspect of the present invention includes a sheet storage unit that stores a sheet bundle formed by stacking a plurality of sheets, a transport element that takes out and transports the sheet from the sheet bundle, and a transport direction of the sheet An air supply mechanism including an air supply port from which gas is discharged toward a side surface of the sheet bundle along, and the air supply port includes an upstream air supply port disposed on the upstream side in the conveying direction; And a downstream air supply port disposed on the downstream side in the transport direction, and a main air supply port disposed between the upstream air supply port and the downstream air supply port. Claim 1).

  According to the above configuration, the conveying element takes out and conveys the sheet from the sheet bundle accommodated in the sheet accommodating portion. The sheet bundle is formed by laminating a plurality of sheets and includes a side surface along the sheet conveyance direction. Gas is discharged from the air supply port of the air supply mechanism to the side surface of the sheet bundle. According to the above configuration, the air supply port from which the gas is released is disposed between the upstream air supply port disposed on the upstream side, the downstream air supply port disposed on the downstream side, and between these. Includes main air inlet. Therefore, when the gas from the main air supply port first causes separation of the sheet, the gas from the upstream air supply port and the gas from the downstream air supply port may play a role in promoting the separation of the sheet. it can. When the gas from the upstream air inlet first causes separation of the sheet, the gas from the main air inlet prompts the separation of the sheet, and then the gas from the downstream air inlet further promotes the separation of the sheet. It will be. When the gas from the downstream air inlet first causes separation of the sheet, the gas from the main air inlet prompts the separation of the sheet, and then the gas from the upstream air inlet further promotes the separation of the sheet. It will be. In this way, when any of the gas from the plurality of air supply ports causes separation of the sheet, from the air supply port adjacent to the air supply port from which the gas that first caused separation of the sheet was sent out. This gas plays a role of promoting separation of the sheet. For this reason, even when the adhesion between the sheets is locally high, the separation of the sheets can be preferably caused, and the defect rate related to the separation of the sheets can be reduced.

  In the above configuration, the upstream air supply port is defined as an intermediate position of a section from a first position defined as an intermediate position between the upstream edge and the downstream edge of the sheet bundle to the upstream edge. It is preferable that the gas is disposed so as to be released toward the position.

  According to the above configuration, the distance from the second position to the first position to which the gas from the upstream air supply port is directed is equal to the distance from the second position to the upstream edge, and therefore flows toward the upstream edge. The gas flow rate is not increased unnecessarily, and the separation action between the sheets by the gas from the upstream air supply port can be suitably exhibited.

  In the above configuration, the downstream air supply port is the middle of the section from the first position to the downstream edge defined as the intermediate position between the upstream edge and the downstream edge of the sheet bundle. It is preferable that the gas is discharged toward a third position defined as a position (Claim 3).

  According to the above configuration, the distance from the third position to the first position where the gas from the downstream air supply port is directed is equal to the distance from the third position to the downstream edge, and therefore flows toward the downstream edge. The flow rate of the gas is not increased unnecessarily, and the separation action between the sheets by the gas from the downstream air supply port can be suitably exhibited.

  In the above configuration, the main air supply port is configured such that the upstream air supply port is directed toward a first position defined as being defined as an intermediate position between an upstream edge and a downstream edge of the sheet bundle. The upstream air supply port is disposed so as to be discharged, and is arranged so that the gas is discharged toward a second position defined as an intermediate position of a section from the first position to the upstream edge. Preferably, the downstream air supply port is disposed so that the gas is discharged toward a third position defined as an intermediate position of a section from the first position to the downstream end edge. (Claim 4).

  According to the above configuration, the distance from the upstream end edge to the second position where the air from the upstream air supply port is directed, the distance from the second position to the first position where the air from the main air supply port is directed, from the first position Since the distance to the third position where the air from the downstream air supply port is directed is equal, the separation action between the sheets is not extremely weakened on either the upstream side or the downstream side, and the adjacent sheets are preferably separated. It becomes possible to do.

  In the above configuration, the air supply port includes a first sub-air supply port from which the gas is discharged toward a region between the upstream end edge and the second position, the second position, and the first position. A second sub-air supply port from which the gas is released toward a region between the second sub-air supply port and a third sub-air supply from which the gas is released toward a region between the first position and the third position. It is preferable to further include a fourth sub-air supply port from which the gas is discharged toward a region between the third position and the downstream end edge.

  According to the above configuration, the region existing between the positions to which the gas from the upstream air supply port, the main air supply port, and the downstream air supply port is directed, the region between the upstream edge and the second position, and the downstream edge. Since the gas is released toward each of the regions between the third positions, separation between the sheets can be achieved more preferably. Separation between sheets can be preferably achieved particularly for large sheets.

  In the above configuration, the main air supply port, the upstream air supply port, the downstream air supply port, the first sub air supply port, the second sub air supply port, the third sub air supply port, and the fourth sub air supply port. It is preferable that the air supply ports are arranged at equal intervals.

  According to the above configuration, the separation effect between the sheets can be equalized.

  An image forming apparatus according to another aspect of the present invention includes: a sheet conveying mechanism that accommodates and conveys a sheet; and an image forming unit that forms an image on the sheet fed from the sheet conveying mechanism, and the sheet The transport mechanism includes a sheet storage unit that stores a sheet bundle formed by stacking a plurality of the sheets, a transport element that takes out and transports the sheet from the sheet bundle, and a side surface of the sheet bundle along the transport direction of the sheet. An air supply mechanism that includes an air supply port that discharges gas toward the upstream side, and the air supply port is disposed on the upstream side in the transport direction, and on the downstream side in the transport direction. It includes a downstream air supply port disposed, and a main air supply port disposed between the upstream air supply port and the downstream air supply port (Claim 7).

  According to the above configuration, the conveying element takes out and conveys the sheet from the sheet bundle accommodated in the sheet accommodating portion. The sheet bundle is formed by laminating a plurality of sheets and includes a side surface along the sheet conveyance direction. Gas is discharged from the air supply port of the air supply mechanism to the side surface of the sheet bundle. According to the above configuration, the air supply port from which the gas is released is disposed between the upstream air supply port disposed on the upstream side, the downstream air supply port disposed on the downstream side, and between these. Includes main air inlet. Therefore, when the gas from the main air supply port first causes separation of the sheet, the gas from the upstream air supply port and the gas from the downstream air supply port may play a role in promoting the separation of the sheet. it can. When the gas from the upstream air inlet first causes separation of the sheet, the gas from the main air inlet prompts the separation of the sheet, and then the gas from the downstream air inlet further promotes the separation of the sheet. It will be. When the gas from the downstream air inlet first causes separation of the sheet, the gas from the main air inlet prompts the separation of the sheet, and then the gas from the upstream air inlet further promotes the separation of the sheet. It will be. In this way, when any of the gas from the plurality of air supply ports causes separation of the sheet, from the air supply port adjacent to the air supply port from which the gas that first caused separation of the sheet was sent out. This gas plays a role of promoting separation of the sheet. For this reason, even when the adhesion between the sheets is locally high, the separation of the sheets can be preferably caused, and the defect rate related to the separation of the sheets can be reduced. As a result, the sheets are suitably taken out from the sheet storage portion one by one and are subjected to image forming processing by the image forming portion.

  As described above, the sheet conveyance mechanism and the image forming apparatus according to the present invention can reduce the defect rate related to sheet separation.

It is a schematic diagram of a sheet conveyance mechanism concerning one embodiment of the present invention. It is a figure explaining an example of the behavior of the sheet bundle at the time of air feeding. It is the schematic of the other sheet conveyance mechanism which concerns on one Embodiment of this invention. FIG. 4 is a diagram showing an internal structure of a digital copying machine incorporating a stocker to which the principle of the sheet conveying mechanism shown in FIGS. 1 and 3 is applied. FIG. 4 is a cross-sectional view illustrating an air feeding mechanism of the sheet conveying mechanism shown in FIGS. 1 and 3. FIG. 4 is a cross-sectional view illustrating an air feeding mechanism of the sheet conveying mechanism shown in FIGS. 1 and 3. FIG. 5 is a diagram schematically showing a tray lifting mechanism of the digital copying machine shown in FIG. 4. FIG. 5 is a diagram schematically showing a feeding device of the digital copying machine shown in FIG. 4. FIG. 2 is a cross-sectional view illustrating a stocker of the digital copying machine shown in FIG. 1.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that terms used in the following description, such as “up”, “down”, “left”, “right” and the like, are merely for the purpose of clarifying the explanation and do not limit the present invention. Not what you want. In the following description, “upstream side”, “downstream side”, or similar terms mean “upstream side” or “downstream side” in the sheet conveyance direction unless otherwise specified.

  FIG. 1 is a conceptual diagram illustrating the principle according to an embodiment of the present invention. FIG. 1A is a perspective view of a sheet bundle formed by stacking a plurality of sheets, and FIG. 1B promotes separation between sheets in the sheet bundle shown in FIG. It is a conceptual diagram of a sheet conveying mechanism that separates and conveys sheets one by one from a bundle. In addition, although the sheet | seat shown by FIG. 1 can be mainly used as a coated paper, a tracing paper, and an OHP film sheet, this invention is not restricted to this, It laminated | stacked and was preserve | saved for the predetermined time. Any sheet-like material conveyed from the state may be a conveyance target.

  Each sheet S constituting the sheet bundle T shown in FIG. 1 includes a rectangular processing surface PS and an edge surrounding the processing surface PS. The edge is located at the leading edge of the sheet S conveyance direction (indicated by an arrow in FIG. 1A) and at a position facing the downstream edge DE, and the sheet S conveyance direction. An upstream edge UE positioned on the rear side, and a pair of side edges SE extending between both ends of the upstream edge UE and both ends of the downstream edge DE and extending in the conveying direction of the sheet S Including. In the following description, the surface of the sheet bundle T in which the side edges SE are stacked (the surface extending in the direction perpendicular to the processing surface PS) is referred to as a stacked surface SS. Further, the surface of the sheet bundle T formed by stacking the downstream edges DE (the surface extending in the direction perpendicular to the processing surface PS) is referred to as a downstream lamination surface DS. A surface of the sheet bundle T formed by stacking the upstream edges UE (a surface extending in a direction perpendicular to the processing surface PS) is referred to as an upstream lamination surface US. The stacking surface SS includes the lowermost position of the sheet bundle T and the side edges SE of the pair of sheets S existing at the uppermost position, the upstream edge UT formed by stacking the ends of the upstream edges UE, and the ends of the downstream edges DE. And a downstream end edge DT formed by stacking layers. The upstream lamination surface US is surrounded by the lowermost position of the sheet bundle T and the upstream edge UE of the pair of sheets S existing at the uppermost position and the pair of upstream end edges UT. The downstream lamination surface DS is surrounded by the lowermost position of the sheet bundle T and the downstream edge DE of the pair of sheets S existing at the uppermost position and the pair of downstream end edges DT. In the following description, the processing surface PS is subjected to printing processing (image forming processing), but the present invention is not limited to this, and for example, desired processing such as perforation processing or bending processing is performed. Also good.

  The sheet transport mechanism 600 includes a sheet storage unit 610 that stores the sheet bundle T. The sheet storage unit 610 is, for example, a substantially rectangular parallelepiped box having an open top, and includes a bottom 611 and a peripheral wall 612 that extends upward from the periphery of the bottom 611. For example, a thin plate-like support plate 620 is disposed in the sheet storage unit 610. The support plate 620 contacts the lower surface of the sheet bundle T and supports the sheet bundle T in the sheet storage unit 610. The sheet transport mechanism 600 further includes a transport element 630 that takes out and transports the sheets S from the sheet bundle T one by one. FIG. 1 shows a pickup roller that rotatably contacts the upper surface (processing surface PS) of the sheet bundle T as the conveying element 630. The pickup roller 630 shown in FIG. 1 abuts on the sheet S in the vicinity of the downstream edge DE of the sheet S and extends in the width direction of the sheet S (direction orthogonal to the transport direction). In the present invention, the conveyance element 630 is not limited to the illustrated pickup roller, and may have another structure that allows the sheet to be taken out from the sheet bundle T and conveyed. For example, a spring body (not shown) is disposed between the support plate 620 and the bottom portion 611 of the sheet storage unit 610, and the support plate 620 is urged upward so that the sheet bundle T The sheet S existing at the uppermost position is pressed against the pickup roller 630. As a result, when the pickup roller 630 rotates, the sheet S existing at the uppermost position of the sheet bundle T is taken out from the sheet bundle T and conveyed.

  The sheet conveyance mechanism 600 further includes an air supply mechanism 640. The air supply mechanism 640 is fed from an air supply source 641 such as a fan or a blower containing a drive source such as a motor (not shown) connected to a drive source such as a motor (not shown) and the air supply source 641. And a conduit 642 for guiding the gas to be discharged. The distal end portion of the pipe line 642 becomes an air supply port that opens toward the stacking surface SS and discharges the gas sent from the air supply source 641 toward the stacking surface SS. The sheet conveyance mechanism 600 shown in FIG. 1 has an upstream air supply port 643 arranged on the upstream side, a downstream air supply port 644 arranged on the downstream side, and an upstream air supply port 643 as downstream air supply ports. A main air inlet 645 disposed between the air inlet 644 is included.

  The main air supply port 645 is disposed so that gas is discharged toward the central region of the stacked surface SS (the first position defined as the intermediate position of the section from the upstream end edge UT to the downstream end edge DT). It is preferable. In the following description, an area of the stacked surface SS existing between the intermediate position C of the section defined by the upstream end edge UT and the downstream end edge DT and the upstream end edge UT is referred to as an upstream area UR. In addition, a region of the stacked surface SS existing between the intermediate position C of the section defined by the upstream edge UT and the downstream edge DT and the downstream edge DT is referred to as a downstream region DR. The upstream air supply port 643 is disposed so that gas is discharged toward the central region of the upstream region UR (second position C2 defined as the intermediate position of the section from the first position C1 to the upstream edge UT). It is preferred that The downstream air supply port 644 is arranged so that gas is discharged toward the central region of the downstream region DR (the third position C3 defined as the intermediate position of the section from the first position C1 to the downstream edge DT). It is preferred that When the arrangement of the air supply ports 643 to 645 shown in FIG. 1 is followed, the distance from the upstream edge UT to the second position C2 where the gas from the upstream air supply port 643 is directed, and the second position C2 to the main air supply port 645. The distance from the first position C1 to the first position C1, the distance from the first position C1 to the third position C3 to which the gas from the downstream air supply port 644 is directed, and the distance from the third position C3 to the downstream edge DT are Will be equal. For example, when the sheet S is the A4 size of the vertical size, these distances are about 74 mm (about 53 mm for the horizontal size).

  2 is a perspective view showing the behavior of the sheet bundle T when the upstream air supply port 643 or the downstream air supply port 644 shown in FIG. 1 is disposed at a position extremely close to the upstream end edge UT or the downstream end edge DT. FIG. The behavior of the sheet bundle T will be described with reference to FIG. 1 together with FIG.

  The upstream air supply port 643 or the downstream air supply port 644 is preferably arranged at a distance of 50 mm or more from the upstream end edge UT or the downstream end edge DT. For example, when the distance between the upstream air supply port 643 or the downstream air supply port 644 and the upstream end edge UT or the downstream end edge DT is less than 20 mm, the air discharged from the upstream air supply port 643 or the downstream air supply port 644 2 flows in a direction that tends to flow, and as shown in FIG. 2, once separation between the sheets S is performed at the upstream edge UT or the downstream edge DT, air is directed toward the inside between the separated sheets. However, the separation effect to the other edge region of the sheet S is remarkably reduced.

  In the present embodiment, the gas sent out by the air supply source 641 is, for example, air that has been warmed to such an extent that the water component absorbed by the sheet S can be evaporated, but the present invention is not limited to this. A sufficiently dried gas or a gas composed of a specific component such as nitrogen can be used as desired. Alternatively, the gas sent out by the air supply source 641 can be air fed with a predetermined wind speed. By sending an arbitrary gas toward the sheet S, moisture that induces the close contact between the sheets S can be suitably evaporated.

  FIG. 3 is a schematic diagram illustrating a sheet conveying mechanism 600 that conveys a sheet S having a size larger than the sheet S illustrated in FIG. 1 (for example, an A3 size sheet S). Compared with the sheet conveying mechanism 600 shown in FIG. 1, the sheet conveying mechanism 600 shown in FIG. 3 includes a large number of air supply ports. Other structures are the same as those shown in FIG. 1, and only the differences will be described in the following description.

  The sheet conveying mechanism 600 shown in FIG. 3 has a first sub-air inlet that discharges air to the region of the stacking surface SS between the second position C2 to which the air from the upstream air-feed port 643 travels and the upstream edge UT. 646, a second sub-air inlet 647 that discharges air to the region of the laminated surface SS between the first position C1 and the second position C2 toward which the air from the main air-supply port 645 is directed, and the first position C1 and the downstream air-feed The third sub-air supply port 648 that discharges air to the region of the stacked surface SS between the third position C3 to which the air from the air port 644 heads and the stacked surface SS between the third position C3 and the downstream edge DT. A fourth sub-air inlet 649 that discharges air is included in the area of the first sub-air. These air supply ports 643 to 649 are preferably arranged at equal intervals. For example, when the sheet S is A3 size, the distance between them is about 74 mm.

  The first to fourth air supply ports 646, 647, 648, and 649 may be formed as distal end openings of a pipe line 642 that extends from the air supply source 641 and guides the air sent from the air supply source 641. it can.

  FIG. 4 shows an internal structure of an image forming apparatus incorporating a stocker to which the principle of the sheet conveying mechanism 600 described with reference to FIGS. 1 and 3 is applied. The image forming apparatus will be described with reference to FIGS. 1 and 3 in conjunction with FIG. Note that the image forming apparatus shown in FIG. 4 is a digital copying machine, but the present invention is not limited to this, and a printer, a facsimile, a multi-function machine having a plurality of functions including an image forming function, or a sheet It can be set as the apparatus for performing arbitrary processing to the processing surface PS of S.

  The digital copying machine 1 includes a housing 2 formed in a substantially rectangular parallelepiped, a storage unit 3 that is disposed in the lower part of the inner space of the housing 2 and stores the sheet S, and takes out the sheet S from the storage unit 3 and conveys it. A conveying unit 4 that performs the transfer, an image forming unit 5 that forms a toner image on the surface of the sheet S that is being conveyed, a fixing unit 6 that fixes the toner image formed on the sheet onto the processing surface PS of the sheet S, and a toner And a discharge unit 7 for discharging the sheet S on which the image is fixed to the outside of the housing 2. A document reading unit 8 for reading a document image is disposed on the upper portion of the housing 2. The document reading unit 8 reads an image of a document and converts it into electronic data.

  The storage unit 3 includes a first cartridge 31 and a second cartridge 32 that store a sheet bundle T including a small amount of sheets S. The second cartridge 32 is disposed above the first cartridge 31. The storage unit 3 further includes a stocker 33 that is formed so as to be able to store a sheet bundle T including a number of sheets S that can be stored in the first cartridge 31 and the second cartridge 32. The stocker 33 is disposed above the second cartridge 32. The stocker 33 corresponds to the sheet storage unit 610 of the sheet transport mechanism 600 described with reference to FIGS. 1 and 3.

  The stocker 33 includes a substantially rectangular plate-shaped bottom portion 331 and a peripheral wall portion 332 extending upward from the periphery of the bottom portion 331. The bottom portion 611 and the peripheral wall portion 612 of the sheet storage unit 610 provided in the sheet conveying mechanism 600 described with reference to FIGS. 1 and 3 correspond to the bottom portion 331 and the peripheral wall portion 332 of the stocker 33, respectively. The upper edge of the peripheral wall portion 332 forms an opening of the stocker 33. The sheet S accommodated in the internal space of the stocker 33 defined by the bottom portion 331 and the peripheral wall portion 332 is taken out by the transport unit 4 through the opening formed in the upper portion of the stocker 33 and transported toward the image forming unit 5. Is done. It is preferable that the first cartridge 31, the second cartridge 32, and the stocker 33 can be pulled out from the inside of the housing 2.

  The stocker 33 further includes a partition plate 333 disposed across the internal space of the stocker 33 in the vertical direction. The partition plate 333 extends upward from the bottom portion 331, and partitions the internal space of the stocker 33 into small spaces adjacent to each other in the right and left in FIG. The small space formed on the left side will be referred to as the first housing part for convenience, and the small space formed on the right side will be referred to as the second housing part for convenience. A first tray 334 is disposed in the first housing portion, and a second tray 335 is disposed in the second housing portion. The support plate 620 of the sheet conveying mechanism 600 shown in FIG. 1 corresponds to the first tray 334 and / or the second tray 335.

  For convenience, the sheet bundle T disposed in the first storage unit will be referred to as a first sheet bundle T1, and the sheet bundle T disposed in the second storage unit will be referred to as a second sheet bundle T2. The first tray 334 includes a support surface that supports the first sheet bundle T1. The second tray 335 includes a support surface that supports the second sheet bundle T2. The partition plate 333 is erected between the first sheet bundle T1 and the second sheet bundle T2, and when the first sheet bundle T1 and / or the second sheet bundle T2 is about to collapse, The first sheet bundle T1 and / or the second sheet bundle T2 can be supported from the side. The partition plate 333 is detachably attached to the bottom portion 332 of the stocker 33.

  The main air supply port 645, the upstream air supply port 643, and the downstream side described in relation to FIGS. 1 and 3 are formed in the peripheral wall portion 332 on the back surface side that forms the first storage unit in which the first sheet bundle T1 is stored. An air supply port 644 is formed. Similarly to the first storage portion, the main air supply port 645, the upstream air supply port 643, and the downstream air supply port are also provided on the peripheral wall portion 332 on the back side that forms the second storage unit in which the second sheet bundle T2 is stored. 644 is formed (in FIG. 4, the air supply ports 643, 644, 645 of the second storage portion are hidden by the second sheet bundle T2). The main air supply port 645, the upstream air supply port 643, and the downstream air supply port 644 are aligned in the horizontal direction in the vicinity of the upper edge of the peripheral wall portion 332 on the back surface side that forms the first storage portion and the second storage portion. .

  FIG. 5 is a schematic cross-sectional view of the air feeding mechanism 640 attached to the outer surface of the peripheral wall portion 332 on the back side of the first housing portion or the second housing portion shown in FIG. The air supply mechanism 640 will be described with reference to FIGS. 1, 3, and 4 in conjunction with FIG.

  1 and 3, the air supply mechanism 640 is shown very schematically, but the air supply mechanism 640 may have the structure shown in FIG. 5, for example. The air supply mechanism 640 shown in FIG. 5 can be supported by, for example, a bracket (not shown) attached to the outer surface of the peripheral wall portion 332 on the back side of the first storage portion or the second storage portion.

  The air supply mechanism 640 shown in FIG. 5 includes an air supply source 641 and a conduit 642 as described with reference to FIGS. 1 and 3. The proximal end portion of the pipe line 642 is integrally connected to a housing 141 that forms the outer surface of the air supply source 641. The pipe line 642 includes a main pipe 241 extending in one direction from the housing 141 and three branch pipes 242 branched from the main pipe 241. The distal ends of the three branch pipes 242 are opened. For example, the distal opening of the branch pipe 242 close to the proximal end of the conduit 642 of the main pipe 241 is used as the upstream air supply port 643, and the distal opening of the central branch pipe 242 is used. Can be the main air supply port 645, and the tip opening of the branch pipe 242 close to the tip of the pipe 642 can be the downstream air supply port 644.

  A suction fan 142 and a heater 143 are disposed in the housing 141. The suction fan 142 is rotatably supported in the housing 141 by a rotating shaft of a motor 144 disposed outside the housing 141. An opening 145 is formed on the surface of the housing 141 opposite to the surface on which the motor 144 is attached. When the motor 144 is operated, the suction fan 142 rotates, and the air around the air supply source 641 is drawn into the housing 141 through the opening 145.

  The heater 143 is disposed between the connection portion between the pipe line 642 and the housing 141 and the suction fan 142. The air drawn into the housing 141 by the suction fan 142 passes through the heater 143 and the conduit, and is discharged from the air supply ports 643, 644, 645 toward the stacking surface SS of the sheet bundle T in the stocker 33. . The heater 143 warms the air passing through the heater 143. Therefore, the air discharged from the air supply ports 643, 644, 645 prompts the removal of the water component contained in the sheet bundle T in the stocker 33, and as a result, the separation of the sheet bundle T between the sheets is promoted. Become.

  FIG. 6 illustrates another structure of the air supply mechanism 640. The air supply source 641 shown in FIG. 5 branches the three branch pipes 242 from one main pipe 241 to form the air supply ports 643, 644, 645, but like the air supply mechanism 640 shown in FIG. The air supply ports 643, 644, and 645 may be formed using an elbow pipe 243 extending from the housing 141 of the air supply source 641. In this case, the upstream air supply port 643, the main air supply port 645, and the downstream air supply port 644 are formed using the individual air supply mechanisms 640, respectively.

  Note that the air supply mechanism 640 described with reference to FIGS. 5 and 6 is merely illustrated for description, and does not limit the present invention. Any mechanism capable of releasing air toward the air supply mechanism 640 can be used.

  FIG. 7 shows an example of an elevating mechanism for moving the first tray 334 and the second tray 335 up and down. The lifting mechanism will be described with reference to FIG. 4 together with FIG. 7. Note that the lifting mechanism shown in FIG. 7 is merely an example, and any mechanism that can move the first tray 334 and the second tray 335 up and down may be used as the lifting mechanism.

  The lifting mechanism 34 includes a plurality of wires 341 having one end connected to the first tray 334 and the second tray 335 and a first drum around which the other end of the wire 341 connected to the first tray 334 is wound. 342, the second drum 343 around which the other end of the wire 341 connected to the second tray 335 is wound, the path of the wire 341 connecting the first tray 334 and the first drum 342, and the second tray 335 A plurality of pulleys 345 disposed in the middle of the path of the wire 341 connecting the second drum 343.

  The first drum 342 is connected to the first drive source 346. The second drum 343 is connected to the second drive source 347. The first drive source 346 and the second drive source 347 are electrically connected to a control unit 348 such as a control circuit. The first drive source 346 and the second drive source 347 drive the first drum 342 and the second drum 343, respectively, under the control of the control unit 348. The control unit 348 can control the entire digital copying machine 1. In the present embodiment, a pulse motor, a motor with an encoder, or the like can be used as the first drive source 346 and the second drive source 347, but the first drum 342 and the second drum 343 are driven to rotate. It is also possible to use other devices that can. Furthermore, in this embodiment, by rotating the first drum 342 and the second drum 343, the wire 341 is wound around the first drum 342 and the second drum 343, and the first tray 334 and the second tray 335 are raised. Although the structure is adopted, the present invention is not limited to this, and for example, a piston cylinder can be used instead of the rotating drums 342 and 343 and the driving sources 346 and 347 connected thereto. The first tray 334 and the second tray 335 can be moved in the same manner as in the present embodiment by connecting the end of the wire 341 to the rod tip of the piston cylinder and causing the rod to protrude into and out of the cylinder body.

  While the partition plate 333 is attached to the bottom 331 of the stocker 33, the control unit 348 can control the first drive source 346 and the second drive source 347 independently. By operating only one of the drive source 346 and the second drive source 347, only one of the first tray 334 and the second tray 335 can be raised and moved toward the transport unit 4. Therefore, a sensor device that can detect whether or not the partition plate 333 is attached to the bottom 331 may be used. For example, an optical sensor that forms an optical path that is blocked by the partition plate 333 when the partition plate 333 is attached to the bottom 331 of the stocker 33 can be used as such a sensor device.

  When the first drum 342 and / or the second drum 343 rotates in the direction indicated by the arrow in FIG. 7, the wire 341 is wound around the first drum 342 and / or the second drum 343, and the first tray 334 and / or Alternatively, the second tray 335 is raised. When the sheet bundle T is disposed on the first tray 334 and / or the second tray 335, the first tray 334 and / or the second tray 335 can be lowered by the weight of the sheet bundle T. The elevating mechanism 34 may include a sensor for controlling the height position of the first tray 334 and / or the second tray 335 as necessary.

  The transport unit 4 includes a feeding device 41 disposed in the vicinity of an opening formed in the upper part of the stocker 33. The elevating mechanism 34 raises the first tray 334 and / or the second tray 335 and conveys the sheet bundle T on the first tray 334 and / or the second tray 335 to the feeding device 41.

  FIG. 8 is a schematic diagram of the feeding device 41. The feeding device 41 will be described with reference to FIG. 4 together with FIG. 8. FIG. 8 also shows the structure around the second housing portion of the stocker 33. The feeding device 41 shown in FIG. 8 corresponds to the transport element 630 described with reference to FIGS. 1 and 3.

  As described above, the second tray 335 is disposed in the second storage portion of the stocker 33, and the second sheet bundle T2 is placed on the upper surface of the second tray 335. The feeding device 41 includes a belt device 412 and a second roller device 414. The belt device 412 is disposed above the downstream lamination surface DS of the second sheet bundle T2. As shown in FIG. 4, the feeding device 41 further includes a first roller device 413 for taking out the first sheet bundle T <b> 1 in the first storage portion of the stocker 33. The first roller device 413 is disposed above the right upper surface of the first sheet bundle. The first roller device 413 and the second roller device 414 can have substantially the same structure. FIG. 8 shows a motor 415 for driving the second roller device 414.

  The belt device 412 is disposed on the downstream side of the peripheral wall portion 332 of the stocker 33 and forms one end of the belt device 412. The belt device 412 forms the other end of the belt device 412 and the drive roller 416. A driven roller 417 that is rotated by a driving force, a belt 418 wound around the driving roller 416 and the driven roller 417, and a suction duct 419 disposed between the driving roller 416 and the driven roller 417 are included. FIG. 8 shows a motor 421 for driving the drive roller 416. The suction duct 419 includes a vacuum source (not shown) such as a blower and a pipe line 426 having a rectangular cross section connected to the vacuum source. A plurality of through holes 427 are formed in the bottom wall of the duct 426. The suction force is transmitted to the sheet S existing at the uppermost position of the second sheet bundle T2 through the through holes 427 and a plurality of holes (not shown) formed in the belt 418.

  The second roller device 414 includes a feed roller 422 that rolls on the sheet S present at the uppermost position of the second sheet bundle T2, and a support portion 423 that rotatably supports the feed roller 422. The feed roller 422 rotates around a rotation shaft 424 located at the center of the feed roller 422. The support portion 423 is pivotally supported by a support shaft 425 and can rotate around the support shaft 425. The second roller device 414 further includes a photo interrupter sensor 426 attached to the support portion 423. The photo interrupter sensor 426 detects the attitude of the support portion 423. When the elevating mechanism 34 described with reference to FIG. 7 raises the second tray 335, the upper surface of the second sheet bundle T2 on the second tray 335 comes into contact with the feed roller 422, and the support portion 423 is the support shaft. Rotate around 425. The photo interrupter sensor 426 transmits a detection signal to the control unit 348 (see FIG. 7) when it is detected that the support unit 423 is in a predetermined posture (tilt angle). The control unit 348 stops the raising operation of the second tray 335 based on the detection signal. A gear mechanism (not shown) is constructed between the motor 415 and the feed roller 422. The gear mechanism transmits a driving force to the feed roller 422 while allowing the support portion 423 to rotate.

  When the rising of the second tray 335 for transporting the second sheet bundle T2 to the transport unit 4 is stopped based on the detection signal of the photo interrupter sensor 426, the air supply described with reference to FIGS. The mechanism 640 operates, and warm air is discharged from the air supply ports 643, 644, 645 toward the stack surface SS of the second sheet bundle T2. As a result, air is introduced between the sheets S constituting the second sheet bundle T2, and separation between the sheets S is promoted. The motor 415 rotates the feed roller 422 to move the sheet S existing at the uppermost position of the second sheet bundle T2 to the left by a predetermined distance. As a result, the right edge of the sheet S existing at the uppermost position of the second sheet bundle T2 is positioned below the suction duct 419 of the belt device 412. The suction force from the suction duct 419 is transmitted to the right edge of the sheet S moved leftward via the belt 418. As a result, the right edge of the sheet S moved to the left is attracted to the belt 418, and the sheet S is taken out from the stocker 33. Thereafter, the motor 421 and / or the motor 415 rotates the belt 418 and / or the feed roller 422 counterclockwise, and feeds the sheet S adsorbed on the belt 418 downstream.

  Although the description has been given of taking out the sheet S from the stocker 33 using the second sheet bundle T2 in the second containing unit, the principle of taking out the sheet S and the structure for taking out the sheet S described above are described in the first containing case. The present invention can also be applied to the first sheet bundle T1 in the section.

  Refer to FIG. 4 again. The transport unit 4 includes a transport path 43 that extends in the vertical direction on the right side of the storage unit 3. The sheet S taken out from the stocker 33 by the belt device 412 is conveyed downstream along the conveyance path 43. The transport unit 4 further includes a pickup roller 44 disposed in the vicinity of the upper right corner of the first cartridge 31 and the second cartridge 32, and a separation / feed roller 45 disposed downstream of the pickup roller 44. . The pickup roller 44 and the separation / feed roller 45 take out the sheets S one by one from the first cartridge 31 and / or the second cartridge 32 and convey them to the conveyance path 43. The transport unit 4 further includes a plurality of transport rollers 46 disposed along the transport path 43. The conveyance roller 46 conveys the sheet S sent from the stocker 33, the first cartridge 31, or the second cartridge 32 to the image forming unit 5 along the conveyance path 43.

  The image forming unit 5 includes a substantially cylindrical photosensitive drum 51 that is rotatably supported by the housing 2, and a charger 52 disposed above the photosensitive drum 51. The photosensitive drum 51 rotates clockwise in FIG. The charger 52 applies a charge to the photosensitive drum 51 and uniformly charges the circumferential surface of the photosensitive drum 51. The image forming unit 5 further includes an exposure device 53. The exposure device 53 irradiates the charged peripheral surface of the photosensitive drum 51 with laser light based on image data obtained by the document reading unit 8 reading an image of the document. As a result, the laser light loses the electric charge on the photosensitive drum 51, so that an electrostatic latent image corresponding to the image data is formed on the photosensitive drum 51. The image forming unit 5 further includes a developing device 54. The developing device 54 includes a toner container 55 that contains toner, and supplies the toner from the toner container 55 to the peripheral surface of the photosensitive drum 51 on which the electrostatic latent image is formed. As a result, a toner image that matches the electrostatic latent image is formed on the peripheral surface of the photosensitive drum 51.

  The image forming unit 5 further includes a transfer belt 56 disposed below the photosensitive drum 51. The sheet S is fed between the photosensitive drum 51 and the transfer belt 56 through the conveyance path 43. When the sheet S passes between the photosensitive drum 51 and the transfer belt 56, the toner image formed on the peripheral surface of the photosensitive drum 51 is applied to the sheet S by applying a reverse bias having a polarity opposite to that of the toner. It will be transcribed.

  The image forming unit 5 further includes a cleaning device 57 that removes the toner remaining on the circumferential surface of the photosensitive drum 51 after the toner image is transferred to the sheet S, and the circumference of the photosensitive drum 51 from which the residual toner has been removed. And a static eliminator 58 for removing residual charges from the surface.

  The sheet S on which the toner image is transferred in the image forming unit 5 is sent to the fixing unit 6. The fixing unit 6 includes a fixing roller 61 and a pressure roller 62 pressed against the fixing roller 61. A heat source 63 is disposed inside the fixing roller 61, and the toner on the sheet S passing between the fixing roller 61 and the pressure roller 62 is melted, and the pressure on the sheet S is applied by the pressure from the pressure roller 62. The toner is fixed on the surface. As a result, the toner image is fixed on the sheet S.

  The discharge mechanism 7 is disposed downstream of the fixing unit 6 and is mounted near the inner wall surface of the housing 2, and a discharge tray 72 that receives the sheet S discharged from the discharge roller 71 to the outside of the housing 2. Including.

  The digital copying machine 1 shown in FIG. 4 includes a conveyance path 47 for double-sided printing between the stocker 33 and the image forming unit 5 / fixing unit 6. The discharge roller 71 can also send out the sheet S to the conveyance path 47 by a switchback method. The conveyance path 47 joins immediately before the registration roller 48 disposed in the middle of the conveyance path 43. The sheet S that has passed through the conveyance path 47 is sent to the image forming unit 5 by the registration roller 48, and the toner image is transferred to the surface of the image forming unit 5 where the toner image is not fixed. Thereafter, the toner image newly transferred by the fixing unit 6 is fixed to the sheet S. Finally, the sheet S is discharged onto the discharge tray 72 by the discharge roller 71.

  FIG. 9 is a cross-sectional view of the stocker 33 to which the arrangement of the air supply ports 643 to 649 shown in FIG. 3 is applied. A partition plate 33 is disposed in the stocker 33 shown in FIG. 9A, and the internal space of the stocker 33 is separated from the first housing portion and the second by the partition plate 333, similarly to the stocker 33 shown in FIG. It is divided into a housing part. The partition plate 333 shown in FIG. 9A is removed from the stocker 33 shown in FIG. 9B.

  As described with reference to FIG. 4, while the partition plate 333 is mounted in the stocker 33, one of the first tray 334 and the second tray 335 rises and supplies the sheet S to the feeding device 41. To do. As described above, the control unit 348 shown in FIG. 3 uses the motor 144 (see FIG. 5 or FIG. 6) of the air supply source 641 by using the signal from the photo interrupter sensor 426 generated by raising the trays 334 and 335 as a trigger signal. Actuate to release air to the stacking surface SS (see FIG. 1) of the sheet bundle T. In each of the first housing portion and the second housing portion of the stocker 33 shown in FIG. 9A, three air supply ports are shown. The air supply port located on the upstream side of each storage unit is an upstream air supply port 643, and the air supply port located on the downstream side of each storage unit is a downstream air supply port 644. The air supply port existing between the air supply port 644 is the main air supply port 645.

  When the partition plate 333 is removed, the stocker 33 can accommodate a large size sheet S. The large size sheet S is supported by the first tray 334 and the second tray 335. The control unit 348 shown in FIG. 3 controls the first tray 334 and the second tray 335 so that the first tray 334 and the second tray 335 rise while maintaining substantially the same height position.

  As shown in FIG. 9B, when the partition plate 333 is removed, one air supply port appears. As described above, when the control unit 348 shown in FIG. 3 operates the motor 144 of the air supply source 641 using the signal from the photo interrupter sensor 426 as a trigger signal, the air supply port that appears due to the removal of the partition plate 333 is It will function as the main air supply port 645. Further, when the partition plate 333 is attached, the air supply port used as the main air supply port 645 of the first housing portion functions as the upstream air supply port 643. When the partition plate 333 is attached, the air supply port used as the main air supply port 645 of the second housing portion functions as the downstream air supply port 644. When the partition plate 333 is attached, the air supply port used as the upstream air supply port 643 of the first housing part functions as the first auxiliary air supply port 646, and the downstream air supply port of the first storage unit The air supply port used as 644 functions as the second auxiliary air supply port 647. When the partition plate 333 is attached, the air supply port used as the upstream air supply port 643 of the third housing portion functions as the third auxiliary air supply port 648, and the downstream air supply port of the second housing portion. The air supply port used as 644 functions as the second auxiliary air supply port 649.

  The present invention can be applied to a printer, a copier, a facsimile machine, a multi-function machine having these functions, and various apparatuses having a function of performing arbitrary processing on the surface of a sheet.

DESCRIPTION OF SYMBOLS 1 ... Digital copying machine 600 ... Sheet conveyance mechanism 630 ... Conveyance element 640 ... Air supply mechanism 643 ... Upstream air supply port 644 ... Downstream air supply port 645 ... Main Air supply port 646... First sub-air supply port 647... Second sub-air supply port 648... Third sub-air supply port 649. Position C2 ... Second position C3 ... Third position DT ... Downstream edge PS ... Processing surface S ... Sheet SS ... Stacked surface (sheet bundle side)
T ... Sheet bundle UT ... Upstream edge

Claims (7)

A sheet storage portion for storing a sheet bundle formed by laminating a plurality of sheets;
A conveying element that removes and conveys the sheet from the sheet bundle;
An air supply mechanism provided with an air supply port through which gas is discharged toward the side surface of the sheet bundle along the sheet conveyance direction;
The air supply port includes an upstream air supply port disposed on the upstream side in the conveying direction, a downstream air supply port disposed on the downstream side in the conveying direction, the upstream air supply port, and the downstream air supply port. And a main air supply opening disposed between the opening and the sheet supply mechanism.   The upstream air supply port is directed toward a second position defined as an intermediate position of a section from a first position defined as an intermediate position between the upstream edge and the downstream edge of the sheet bundle to the upstream edge. The sheet conveying mechanism according to claim 1, wherein the sheet conveying mechanism is disposed so as to release the gas.   The downstream air inlet is defined as an intermediate position of a section from a first position defined as an intermediate position between the upstream edge and the downstream edge of the sheet bundle to the downstream edge. The sheet conveying mechanism according to claim 1, wherein the gas conveying mechanism is disposed so that the gas is discharged toward the third position. The main air supply port is disposed so that the gas is discharged toward a first position defined as being defined as an intermediate position between an upstream edge and a downstream edge of the sheet bundle,
The upstream air supply port is disposed so that the gas is discharged toward a second position defined as an intermediate position of a section from the first position to the upstream edge,
The said downstream air supply port is arrange | positioned so that the said gas may be discharge | released toward the 3rd position defined as the intermediate position of the area from the said 1st position to the said downstream edge. Item 2. A sheet conveying mechanism according to Item 1. A first sub-air port from which the gas is discharged toward a region between the upstream edge and the second position;
A second sub-air inlet from which the gas is released toward a region between the second position and the first position;
A third sub-air inlet from which the gas is discharged toward a region between the first position and the third position;
The sheet conveying mechanism according to claim 4, further comprising a fourth auxiliary air supply port from which the gas is discharged toward a region between the third position and the downstream end edge.   The main air supply port, the upstream air supply port, the downstream air supply port, the first sub-air supply port, the second sub-air supply port, the third sub-air supply port, and the fourth sub-air supply port The sheet conveying mechanism according to claim 5, wherein the sheet conveying mechanism is arranged at equal intervals. A sheet conveying mechanism for accommodating and conveying the sheet;
An image forming unit that forms an image on the sheet fed from the sheet transport mechanism,
The sheet transport mechanism includes a sheet storage unit that stores a sheet bundle formed by stacking a plurality of the sheets,
A conveying element that removes and conveys the sheet from the sheet bundle;
An air supply mechanism including an air supply port for releasing gas toward the side surface of the sheet bundle along the sheet conveyance direction;
The air supply port includes an upstream air supply port disposed on the upstream side in the conveying direction, a downstream air supply port disposed on the downstream side in the conveying direction, the upstream air supply port, and the downstream air supply port. An image forming apparatus comprising a main air supply port disposed between the mouth and the air supply port.

Images