JP5648093B2 - Sheet conveying mechanism and image forming apparatus incorporating sheet conveying mechanism - Google Patents

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. The air feeding mechanism of the paper feeding device discharges air toward the central region on the side surface of the sheet bundle. The sheet feeding device includes a contact member disposed along the vicinity of the edge of the sheet parallel to the air discharge direction and in contact with the upper surface of the sheet bundle. The edge portion of the sheet bundle is pressed by the contact member, and an air layer is formed across the central portion of the sheet bundle, so that separation between sheets in the sheet bundle is achieved.

  Japanese Patent Application Laid-Open No. 2004-228688 is arranged on the downstream side of an air supply mechanism that discharges air to a central region of a stacking surface of a sheet bundle formed by stacking edge portions of sheets parallel to the sheet conveying direction. A sheet feeding device including a contact member is disclosed. The paper feeder of Patent Document 2 also attempts to separate sheets in a sheet bundle by forming an air layer in the sheet bundle using an air feeding mechanism.

  Patent Documents 3 and 4 disclose a paper feeding device in which an air volume variation mechanism is added to the techniques disclosed in Patent Documents 1 and 2.

JP-A-4-23747 JP 2003-63675 A JP 2002-128300 A JP-A-11-5543

  The disclosed technologies of Patent Documents 1 and 2 have a problem that an air layer is formed between sheets with weak adhesion in the sheet bundle, and the adhesion of the bundle of sheets above the air layer cannot be released. Patent Documents 3 and 4 attempt to release the close contact of the sheet bundle above the air layer by increasing or decreasing the flow rate of the air discharged into the sheet bundle. The above-described problem cannot be solved sufficiently only by changing the thickness dimension.

  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 support surface that supports 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 an edge portion of the sheet. A gas supply mechanism for releasing gas toward the stacking surface of the sheet bundle formed by stacking and levitation of a part of the sheet bundle; and a force applied intermittently toward the support surface; A restriction mechanism for restricting the partial levitation of the gas, and the air supply mechanism includes an air supply port that is disposed in the vicinity of the laminated surface and discharges the gas. Includes a contact member that contacts a sheet appearing on the outer surface of the sheet bundle, and the contact member includes a bearing having an annular outer ring portion and an inner ring portion, and a circular plate fitted into the inner ring portion, Corresponding to mouth Characterized by contacting the surface area of the sheet.

  According to the above configuration, a part of the sheet bundle is floated by the gas released toward the stacking surface of the sheet bundle. The restriction mechanism applies force intermittently toward the support surface, and as a result, the separated and floated sheet bundle is pressed by the force toward the support surface. During this period and thereafter, the air supply mechanism continues to release air to form an air layer in the sheet bundle, so that the probability that an air layer is formed in other portions can be increased. As a result, separation between sheets is promoted. In addition, the inertia force generated by the movement of the floated sheet bundle due to physical force also promotes separation between the sheets. The transport element picks up the sheet with separation between the sheets from the sheet bundle and transports the sheet. Therefore, the above configuration can contribute to reducing the defect rate related to sheet separation. Moreover, according to the said structure, since a contact member is arrange | positioned in the part of the sheet | seat bundle with a large floating amount, the effect of the above-mentioned sheet separation can be improved.

  In the above configuration, the contact member is a cam, and the regulation mechanism is eccentrically connected to the contact member and rotates integrally with the contact member, and connected to the rotation shaft and It is preferable to further include a drive source for rotating the rotary shaft.

  According to the above configuration, since the contact member comes into contact with the sheet as an eccentric cam in an eccentric rotational manner, it is possible to repeatedly control and release the lifting of the separated sheet bundle in a relatively short period, and in a relatively short period of time. Separation between sheets can be achieved.

  In the above-described configuration, the apparatus further includes a control unit, and the control unit causes the air supply mechanism to release the gas toward the stacked surface, and while the air supply mechanism releases the gas, It is preferable that the rotating shaft is rotated and the conveying element is made to take out the sheet from the sheet bundle.

  According to the above configuration, the control unit can rotate the rotating shaft while the gas supply mechanism is releasing gas, and can perform separation between sheets in a relatively short period of time as described above. Further, the conveying element can take out the sheet from the sheet bundle which has been subjected to the inter-sheet separation process.

  In the above configuration, the restriction mechanism further includes a cylinder having a rod connected to the contact member, a solenoid valve that switches a path of the working fluid toward the cylinder, and a control unit that controls the solenoid valve. Is preferred.

  According to the above configuration, the air layer can be separated without unnecessarily generating a force parallel to the surface of the sheet.

  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 conveyance mechanism includes a support surface that supports a sheet bundle formed by stacking a plurality of sheets, a conveyance element that takes out and conveys the sheet from the sheet bundle, and the sheet formed by stacking edges of the sheets. An air supply mechanism that releases gas toward the stacking surface of the bundle and levitates a part of the sheet bundle, and intermittently applies force toward the support surface to regulate the levitation of the part of the sheet bundle A restriction mechanism that is disposed in the vicinity of the lamination surface and has an air supply opening for discharging the gas, and the restriction mechanism is provided on an outer surface of the sheet bundle. Appearing sea The contact member includes a bearing having an annular outer ring portion and an inner ring portion, and a circular plate fitted into the inner ring portion, and in a surface area of the seat corresponding to the air supply port. It is characterized by contacting.

  According to the above configuration, a part of the sheet bundle is floated by the gas released toward the stacking surface of the sheet bundle. The restriction mechanism applies force intermittently toward the support surface, and as a result, the separated and floated sheet bundle is pressed by the force toward the support surface. During this period and thereafter, the air supply mechanism continues to release air to form an air layer in the sheet bundle, so that the probability that an air layer is formed in other portions can be increased. As a result, separation between sheets is promoted. In addition, the inertia force generated by the movement of the floated sheet bundle due to physical force also promotes separation between the sheets. The conveying element takes out and conveys the sheet with separation between the sheets from the sheet bundle, and then the image forming unit forms an image on the sheet sent out from the sheet conveying mechanism. Therefore, the above configuration can contribute to reducing the defect rate related to sheet separation.

  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 which shows the control mechanism of the sheet | seat conveyance mechanism shown by FIG. FIG. 2 is a diagram illustrating a principle for regulating the floating of a bundle of sheets separated by a regulation mechanism of the sheet conveying mechanism shown in FIG. 1. It is a figure which shows the contact member which the control mechanism of the sheet | seat conveyance mechanism shown by FIG. 1 contains. It is a figure which illustrates the other structure of a control mechanism. It is a figure which shows the internal structure of a digital copying machine provided with the stocker to which the principle of the sheet | seat conveyance mechanism shown by FIG. 1 was applied. It is a figure which shows an example of the air supply mechanism used for the digital copying machine shown by FIG. It is a figure which shows schematically the raising / lowering mechanism of the tray of the digital copying machine shown by FIG. FIG. 5 is a diagram schematically showing a feeding device of the digital copying machine shown in FIG. 4.

  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.

  The sheet bundle T shown in FIG. 1 includes a plurality of stacked sheets S. Each of the sheets S constituting the sheet bundle T includes a rectangular processing surface PS and an edge that surrounds 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 along the conveyance 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 upper surface of the support plate 620 is in contact with the lower surface of the sheet bundle T and serves as a support surface that 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 643 that opens toward the stacked surface SS and discharges the gas sent from the air supply source 641 toward the stacked surface SS. In FIG. 1, the air supply port 643 formed in the peripheral wall portion 612 located on the back side is indicated by a dotted line, but a similar air supply port 643 is also formed in the peripheral wall portion 612 located on the front side. May be. The air supply port 643 is close to the stacking surface of the sheet bundle T to an extent sufficient to separate and float a part of the sheet bundle T. 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.

  The sheet conveyance mechanism 600 further includes a restriction mechanism 650. In FIG. 1, a plate-like contact member 651 and a rotating shaft 652 that is eccentrically connected to the contact member 651 are shown as the regulation mechanism 650. The contact member 651 shown in FIG. 1 functions as a cam.

  FIG. 2 is a cross-sectional view of the sheet accommodating portion 610 in the air supply port 543 of the air supply mechanism 640 shown in FIG. The regulating mechanism 650 of the sheet conveying mechanism 600 will be further described with reference to FIG. 1 in conjunction with FIG.

  As shown in FIG. 2, a pair of contact members 651 are disposed in the vicinity of each of the pair of stacked surfaces SS of the sheet bundle T. The rotating shaft 652 extends between the pair of contact members. The rotation shaft 652 further extends through the contact member 651 located on the right side. A gear 653 is formed at the right end of the rotating shaft 652. The restriction mechanism 650 further includes a motor 654 used as a drive source. A gear 655 attached to the tip of the rotating shaft of the motor 654 meshes with a gear 653 disposed at the right end of the rotating shaft 652. In FIG. 2, the peripheral wall portion 612 shown on the right side is the back wall 612a, and the peripheral wall portion 612 shown on the left side is the front wall 612b. An air supply port 643 is formed in the back wall 612a and the front wall 612b, and the pair of air supply ports 643 face each other. The rotation shaft 652 extends along a line connecting the pair of air supply ports 643. The contact member 651 is positioned in the direction in which the gas from the air supply port 643 is released, and is the surface of the uppermost sheet S that appears on the outer surface of the sheet bundle T, and in a surface region corresponding to the air supply port 643. Contact. When the motor 654 rotates the rotary shaft 652 attached eccentrically to the contact member 651, the contact member 651 rotates integrally with the rotary shaft 652, and intermittently applies a force toward the upper surface of the support plate 642. Will be given to T.

  FIG. 3 is a view for explaining a regulation principle for regulating the floating of the separated sheet bundle by the regulation mechanism 650 shown in FIG. 3A shows an air layer formed in the sheet bundle T by the air supply mechanism 640 shown in FIG. 1, and FIG. 3B shows a first example in which the outer peripheral contour of the contact member 651 is located at the uppermost position. FIG. 3C shows the sheet bundle T when the outer peripheral contour of the contact member 651 is located at the lowest position. With reference to FIG. 1 in conjunction with FIG. 3, the regulation principle for regulating the floating of the separated sheet bundle will be described.

  By the operation of the air supply source 641, the gas is released from the air supply port 643. The gas sent out from the air supply port 643 collides with the lamination surface SS of the sheet bundle T. The adhesion force between the sheets S constituting the sheet bundle T is not uniform, and the gas colliding with the laminated surface SS tends to enter between the sheets S having a weak adhesion force. As a result, the gas discharged from the air supply port 643 floats the sheets S forming the sheet bundle, and forms a gas layer (gas flow path) in the sheet bundle T.

  Once the gas layer is formed, the gas from the air supply port 643 continues to pass through the gas layer, and separation between the floated sheets S is not promoted. For this reason, in this embodiment, by using the regulating mechanism 650, the floating of the sheet bundle T is regulated by compressing the gas layer, and the separation between the sheets S into other parts of the sheet bundle T is promoted. As shown in FIG. 3B, when the contact member 651 exists at the first position, a gas layer is formed in the sheet bundle T, and separation between the sheets S is promoted. Thereafter, when the rotary shaft 652 is rotated, the contact member 651 reaches the second position and compresses the gas layer. As a result, the gas sent out from the air supply port 643 again collides with the lamination surface SS of the sheet bundle T, and a new gas layer is formed in the sheet bundle. When the contact member 651 repeats the operations shown in FIGS. 3A and 3B, the floating of the sheet bundle T is regulated intermittently, and separation between the sheets S is promoted in the entire sheet bundle T. It will be.

  FIG. 4 shows the contact member 651 of the regulating mechanism 650 described with reference to FIGS. The contact member 651 will be described with reference to FIGS. 1 and 3 in conjunction with FIG. 4. In addition, the contact member 651 shown in FIG. 4 exists in the 2nd position where the outer periphery outline of the contact member 651 is located in the lowest part.

  When the contact member 651 is in the second position, the lower end of the contact member 651 may be disposed slightly above the lower end of the pickup roller 630 (indicated by reference numeral “X” in FIG. 4). Thereby, the contact member 651 can compress the gas layer while reducing the force acting in the direction parallel to the processing surface PS of the sheet S. As a result, it is possible to compress the gas layer and regulate the floating of the sheet bundle while reducing the influence on the conveyance of the sheet S.

  The contact member 651 includes a bearing 513 having an annular outer ring portion 511, an annular inner ring portion 512 disposed concentrically with the outer ring portion 511 in a circular inner space surrounded by the outer ring portion 511, and an inner ring portion 512. And a circular plate 514 to be fitted into the. The circular plate 514 is connected to the rotating shaft 652. The outer ring portion 511 can rotate relative to the inner ring portion 512. The circular plate 514 and the inner ring portion 512 rotate together with the rotation of the rotating shaft 652. When the outer ring portion 511 comes into contact with the sheet S, the outer ring portion 511 rotates relative to the inner ring portion 512, so that the force acting in a direction parallel to the processing surface PS of the sheet S can be reduced. is there. As a result, it is possible to compress the gas layer and regulate the floating of the sheet bundle while reducing the influence on the conveyance of the sheet S.

  FIG. 5 shows another embodiment of the restriction mechanism 650. Unlike the restriction mechanism 650 including the rotating contact member 651 described with reference to FIGS. 1 to 4, the restriction mechanism 650 illustrated in FIG. 5 includes a contact member 651 that reciprocates up and down.

  The regulation mechanism 650 shown in FIG. 5 includes a thin bar-like contact member 651. The contact member 651 extends along the air discharge direction from the air supply port 643 formed in the back wall 612a and the front wall 612b. A pair of cylinders 656 is disposed above the contact member 651, and the distal ends of the rods 657 of the pair of cylinders 656 are connected to the upper surfaces of both ends of the contact member 651. Each of the pair of cylinders 656 is connected to a working fluid source 658 using a pipe line 659. A solenoid valve 660 is disposed in the middle of the pipe line 659. The solenoid valve 660 is electrically connected to the control unit 348 (see the dotted line portion in FIG. 5). The solenoid valve 660 switches the flow path of the working fluid sent from the working fluid source 658 to the cylinder 656 under the control of the control unit 348. Thereby, the rod 657 of the cylinder 656 is expanded and contracted. As a result, the contact member 651 moves up and down, compressing the gas layer and restricting the floating of the sheet bundle as described with reference to FIG.

  FIG. 6 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 2 is applied. The image forming apparatus will be described with reference to FIGS. 1 and 2 in conjunction with FIG. The image forming apparatus shown in FIG. 6 is a digital copying machine, but the present invention is not limited to this, and a printer, a facsimile, a multifunction machine having a plurality of functions including an image forming function, etc., 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 2.

  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 2 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 331, and partitions the internal space of the stocker 33 into small spaces adjacent to each other in the left and right 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 air supply port 643 described in relation to FIGS. 1 and 2 is formed in the peripheral wall portion 332 on the back surface side that forms the first storage portion in which the first sheet bundle T1 is stored. An air supply port 643 is also formed in the peripheral wall portion 332 on the back side that forms the second accommodation portion in which the second sheet bundle T2 is accommodated, as in the first accommodation portion (in FIG. 6, The air supply port 643 of the second storage unit is hidden by the second sheet bundle T2. Above the air inlet 643, the restriction mechanism 650 described with reference to FIGS. 1 and 2 is schematically shown.

  FIG. 7 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, 2, and 6 in conjunction with FIG.

  1 and 2, the air supply mechanism 640 is shown very schematically, but the air supply mechanism 640 may have the structure shown in FIG. 7, for example. The air supply mechanism 640 shown in FIG. 7 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. 7 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 is formed by using an elbow pipe 243 extending from the housing 141. The tip of the elbow pipe 243 is opened and becomes an air supply port 643.

  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 port 643 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 port 643 prompts the removal of the water component contained in the sheet bundle T in the stocker 33, and as a result, the separation between the sheets S of the sheet bundle T is promoted.

  Note that the air supply mechanism 640 described with reference to FIG. 7 is merely illustrated for the purpose of illustration, and does not limit the present invention, and air is directed toward the lamination surface SS of the sheet bundle T. Any mechanism capable of releasing can be used as the air feeding mechanism 640.

  FIG. 8 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. 6 together with FIG. 8. Note that the lifting mechanism shown in FIG. 8 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 rotate in the direction indicated by the arrow in FIG. 8, 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. 9 is a schematic diagram of the feeding device 41. The feeding device 41 will be described with reference to FIG. 6 together with FIG. 9. FIG. 9 also shows the structure around the second housing portion of the stocker 33. The feeding device 41 shown in FIG. 9 corresponds to the transport element 630 described with reference to FIGS. 1 and 2.

  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. 6, 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. 9 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. 9 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. 8) 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. The motor 415 for rotating the feed roller 422 can also be used as a motor 654 for operating the restriction mechanism 650 shown in FIG. In this case, the gear mechanism for transmitting the driving force to the feed roller 422 is configured to transmit the driving force to the rotating shaft 652 connected to the contact member 651 at the same time. As a result, the contact member 651 rotates in synchronization with the feed roller 422, and has a restricting action on the floating of the sheet bundle T described with reference to FIG.

  When the rising of the second tray 335 for conveying the second sheet bundle T2 to the conveyance unit 4 is stopped based on the detection signal of the photo interrupter sensor 426, the control unit 348 controls and relates to FIG. The described air supply mechanism 640 is activated, and warm air is discharged from the air supply port 643 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 control unit 348 transmits a control signal of the motor 415, and the motor 415 rotates the feed roller 422 under the control of the control unit 348, so that the sheet S existing at the uppermost position of the second sheet bundle T2 is predetermined leftward. The contact member 651 is moved while being moved by the distance, and the restriction and the release of the restriction on the floating of the second sheet bundle T2 are repeated intermittently. As a result, separation between the sheets S of the second sheet bundle T2 is promoted, and 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. It becomes. 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, under the control of the control unit 348, the motor 421 and / or the motor 415 rotate 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.

  Reference is again made to FIG. 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. 6 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.

  Although the restriction mechanism 650 shown in FIG. 1 is applied to the digital copying machine 1 described with reference to FIG. 6, the restriction mechanism 650 shown in FIG. 5 may be applied. Further, a regulation mechanism having another structure capable of regulating the floating of the sheet bundle T intermittently may be applied.

  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 copier 348 ... Control part 620 ... Support plate 630 ... Conveyance element 640 ... Air supply mechanism 650 ... Restriction mechanism 651 ... Contact member 652 ... Rotating shaft 656 ... Cylinder 657 ... Rod 660 ... Solenoid valve S ... Sheet SS ... Laminated surface T ... Sheet bundle

Claims (5)

A support surface for supporting 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 that releases a gas toward a stacking surface of the sheet bundle formed by stacking edges of the sheets, and floats a part of the sheet bundle;
A regulation mechanism that applies force intermittently toward the support surface and regulates the levitation of the part of the sheet bundle, and
The air supply mechanism includes a pair of air supply ports that are opposed to each other in the width direction of the sheet and are disposed close to the lamination surface and for releasing the gas,
The restriction mechanism is provided on a line connecting the pair of air supply ports, and includes a contact member that contacts a sheet appearing on an outer surface of the sheet bundle,
The sheet conveying mechanism, wherein a lower end of the contact member is disposed slightly above the lower end of the conveying element and contacts a surface area of the sheet corresponding to the pair of air supply ports. The contact member is a cam;
The regulating mechanism is eccentrically connected to the contact member and rotates integrally with the contact member;
The sheet conveying mechanism according to claim 1, further comprising a drive source connected to the rotating shaft and rotating the rotating shaft. A control unit;
The control unit causes the air supply mechanism to release the gas toward the laminated surface, and while the air supply mechanism releases the gas, rotates the rotary shaft to the drive source and the transport element. The sheet conveying mechanism according to claim 2, wherein the sheet is taken out from the sheet bundle. The regulating mechanism includes a cylinder having a rod connected to the contact member;
A solenoid valve that switches a path of the working fluid toward the cylinder;
The sheet conveying mechanism according to claim 1, further comprising a control unit that controls the solenoid valve. 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 conveying mechanism includes a support surface that supports a sheet bundle formed by stacking a plurality of sheets,
A conveying element that removes and conveys the sheet from the sheet bundle;
An air supply mechanism that releases a gas toward a stacking surface of the sheet bundle formed by stacking edges of the sheets, and floats a part of the sheet bundle;
A regulation mechanism that applies force intermittently toward the support surface and regulates the levitation of the part of the sheet bundle, and
The air supply mechanism includes a pair of air supply ports that are opposed to each other in the width direction of the sheet and are disposed close to the lamination surface and for releasing the gas,
The restriction mechanism is provided on a line connecting the pair of air supply ports, and includes a contact member that contacts a sheet appearing on an outer surface of the sheet bundle,
The image forming apparatus according to claim 1, wherein a lower end of the contact member is disposed slightly above the lower end of the transport element and contacts a surface area of the sheet corresponding to the pair of air supply ports.

Images