JP2011057309A - Sheet conveyor and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress non-feed of a lowest sheet with a compact and simple constitution in an air-suction type sheet conveyor employing air assist for enhancing the separate-conveyance performance. <P>SOLUTION: A sheet conveyor 1 includes a bottom plate 19 for stacking sheets thereon, a sheet suction-conveying belt 12C which is arranged above the stacked sheets to suck and convey the highest loaded sheet 2A to the surface, a sheet suction unit 13 for sucking the highest sheet 2A stacked on the bottom plate 19 to the sheet suction-conveying belt 12C with the air suction, an elevating/lowering means 18 for elevating/lowering the bottom plate 19, an air generation unit 22 for generating air to be blown to a sheet end, and an air nozzle 23 for blowing air to the sheet end. An opening part 25 is formed in the bottom plate 19, through which air is passed, and a guide flow passage changing guide 24 is provided so that air blown from the lower part of the air nozzle 23 flows toward the opening part 25 of the bottom plate 19. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sheet conveying apparatus that conveys a sheet to a transfer unit of an image forming apparatus, and an image forming apparatus such as a copying machine, a facsimile, a printer, and an offset printing machine that employs the sheet conveying apparatus.

  In the image forming apparatus, single sheets (hereinafter referred to as sheets) stacked and accommodated in a sheet feeding tray are separated by a sheet conveying apparatus, and are sequentially conveyed one by one and supplied to a transfer unit. As such a sheet conveying apparatus, an FRR system that has a pickup roller, a feed roller, and a reverse roller and conveys the uppermost sheet while being separated by rotational friction of the pickup roller that contacts the upper surface of the sheet is widely used. Yes.

  On the other hand, as a sheet conveying apparatus, a stacking plate that is movable in the vertical direction, a sheet conveying belt that is spaced above the sheets stacked on the stacking plate, and a sheet that is stacked on the stacking plate is used as a sheet conveying belt. 2. Description of the Related Art An air suction type sheet conveying apparatus having a sheet suction unit that sucks air is known. In the air suction type sheet conveying apparatus, the stacking plate is moved so that the uppermost sheet stacked on the stacking plate takes a vertical position optimal for air suction by the sheet suction unit. Then, the uppermost sheet is lifted and separated by air suction of the sheet suction unit, moved and adsorbed onto the upper sheet transport belt, and transported by moving the surface of the sheet transport belt.

  In recent years, with the diversification of recording media, image forming apparatuses have a problem of frequent occurrence of double feeding or non-feeding by a sheet conveying device. Conventionally, sheets used in an image forming apparatus are limited to plain paper such as high-quality paper, and adhesion between stacked sheets is low, so that it is rare that sheets cannot be separated one by one. However, in recent years, sheets having high surface smoothness such as OHP paper, art paper, and coated paper have been used. This is because a sheet with high smoothness has high adhesion between the sheets in a stacked state, and it is difficult to reliably separate and convey the sheets one by one by the sheet conveying device.

  As a technique for improving the separation and conveyance performance of the sheet conveying apparatus, there is an air assist that blows air to the edge of the stacked sheets to loosen the adhesion between the sheets. In the air assist, air is blown onto the end portion of the sheet to move the end portion of the sheet so that the air enters between the sheets that are in close contact, and the air is forced to flow between the sheets to loosen the close contact.

  Japanese Patent Application Laid-Open No. 2004-228561 has a configuration in which air assist is adopted in the FRR type sheet conveying apparatus, and a substantially horizontal direction toward a sheet side end on which a fan for generating air and the air generated by the fan are stacked. Are provided with an air nozzle to be sprayed from.

  Patent Document 2 describes an air suction type sheet conveying apparatus that employs air assist. In this sheet conveying apparatus, air is blown to the end portion of the sheet in the vicinity of the portion sucked upward by the sheet suction unit. Thus, air is forced to flow between the closely contacted sheets to lift the sheet and loosen the contact, thereby facilitating movement to the sheet conveying belt above the uppermost sheet. Japanese Patent Application Laid-Open No. H10-228688 also describes a configuration in which an air nozzle is arranged so as to blow air from an obliquely downward direction toward the sheet end. Compared to a case where air is blown from substantially horizontal, by blowing air from obliquely below, the sheet can be easily lifted upward, and can be easily moved to the upper sheet conveying belt.

  When a highly smooth sheet is used in a sheet conveying apparatus, the lowest sheet is not fed even though the lowest sheet stacked on the stacking plate remains. There's a problem. This problem is particularly likely to occur in an air suction type sheet conveying apparatus.

  This is because, in a state where a plurality of sheets are stacked on the stacking plate, not only the sheets but also the lowermost sheet lower surface and the stacking plate are in close contact with each other. As mentioned above, the air assist moves the end of the sheet by the air blown to the end and the air enters between the sheets, and the air is forced to flow between the sheets to lift the sheet and loosen the adhesion. is there. However, since the stacking plate does not move due to the air blown to the end portion, it is difficult for air to enter between the lowermost sheet lower surface and the stacking plate. For this reason, it is difficult to loosen the contact between the lowermost sheet lower surface and the stacking plate by flowing air.

  When the air is blown obliquely from the lower side toward the end of the sheet, the lowermost sheet can be easily lifted upward, and air can easily enter between the lowermost sheet lower surface and the stacking plate. However, if the adhesion is high due to the sheet characteristics, the effect of loosening the adhesion between the lowermost sheet lower surface and the stacking plate is not sufficient.

  If the close contact between the lowermost sheet lower surface and the stacking plate cannot be sufficiently loosened, the lowermost sheet is difficult to move to the upper sheet conveying belt, and the lowermost sheet is not fed.

  Further, as means for loosening the close contact between the lowermost sheet lower surface and the stacking plate, a fan is provided below the sheet stacking plate, and an opening through which air passes is provided in the sheet stacking plate. It is conceivable to blow air toward the lower surface of the lowermost sheet. In this configuration, the lowermost sheet can be lifted by reliably sending air between the lowermost sheet lower surface and the sheet stacking plate, and the close contact between the lowermost sheet and the stacking plate can be reliably unraveled. However, as the number of fans increases, the apparatus becomes larger.

  On the other hand, in the FRR method, in the sheet conveying apparatus, the lowermost sheet is separated and conveyed by rotational sliding of a pickup roller that contacts the upper surface of the lowermost sheet. For this reason, the lowermost sheet is easier to be conveyed than an air suction type sheet conveying apparatus that moves the sheet to a sheet conveying belt separated by air suction.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a sheet conveying apparatus and an image that can suppress non-feeding of the lowest-level sheet with a small and simple configuration in an air suction type sheet conveying apparatus. A forming apparatus is provided.

In order to achieve the above object, the invention of claim 1 includes a stacking plate on which a plurality of sheets are stacked, a moving means for moving the stacking plate in a vertical direction, and a sheet stacked on the stacking plate. A sheet adsorbing / conveying body that is spaced apart and that attracts the topmost stacked sheets to the surface and conveys them by its own surface movement, and air that generates air to blow onto the end of the sheets stacked on the stacking plate A generator, an air nozzle provided opposite to the sheet end for blowing the air generated by the air generator onto the sheet end stacked on the stacking plate, and the uppermost stack stacked on the stacking plate In a sheet conveying apparatus provided with a sheet suction unit that adsorbs the sheet to the sheet adsorption conveyance body by air suction,
The loading plate is provided with an opening through which air can pass, and a guide member is provided to guide the air blown downward from the loading plate from the air nozzle toward the opening of the loading plate. It is characterized by this.
According to a second aspect of the invention, there is provided the sheet conveying apparatus according to the first aspect, further comprising: a stacking plate position detecting unit that detects a vertical position of the stacking plate, and based on a detection result of the stacking plate position detecting unit, The air generation unit adjusts the air volume generated by the air generation unit.
According to a third aspect of the present invention, in the sheet conveying apparatus according to the first or second aspect, the air volume generated by the air generating unit is adjusted with respect to the stacked sheet size, sheet type, or sheet basis weight. It is characterized by doing.
According to a fourth aspect of the present invention, an image carrier, image forming means for forming a visible image on the image carrier, a plurality of sheets are accommodated, and the accommodated sheets are conveyed one by one. 4. An image forming apparatus comprising: a sheet conveying unit; and a transfer unit that transfers a visible image on the image carrier to a sheet conveyed by the sheet conveying unit. Any one of the sheet conveying apparatuses is employed.
The invention according to claim 5 is characterized in that the image forming apparatus according to claim 4 is a digital copying machine, a printer, a facsimile machine, or an offset printing machine.

  In the present invention, as the sheets stacked on the stacking plate are sequentially conveyed, the stacked uppermost sheet is arranged at a position suitable for being adsorbed by the upper sheet adsorption conveyance body. The loading plate is moved upward by the moving means. Due to the upward movement of the loading plate, the lower part of the air nozzle blows the air generated by the air generating portion downward from the loading plate. Air that is blown downward from the stacking plate is guided by a guide member so as to flow toward the opening of the stacking plate, and is blown to the lower surface of the lowermost sheet stacked on the stacking plate through the opening. Thereby, a part of the air generated from the air generating unit can be blown from the lower side of the stacking plate toward the lower surface of the lowermost sheet. By blowing air from below, air can be surely flowed between the lowermost sheet and the stacking plate to lift the lowermost sheet, thereby loosening the close contact between the lowermost sheet and the stacking plate. The lowermost sheet that has been loosely adhered becomes easy to be adsorbed by the upper sheet adsorbing and conveying body by air suction by the sheet suction unit. Therefore, non-feeding of the lowest sheet is suppressed. As described above, the present invention merely provides the opening portion of the stacking plate and the guide member that allows air to flow toward the opening portion, and does not require a new air generating portion, and has a small and simple configuration.

  According to the present invention, in the air suction type sheet conveying apparatus, there is an excellent effect that non-feeding of the lowermost sheet can be suppressed with a small and simple configuration.

1 is a schematic configuration diagram of a printer according to an embodiment. The side view which shows schematic structure of a sheet conveying apparatus. FIG. 2 is a top view illustrating a schematic configuration of a sheet conveying apparatus. FIG. 4 is a cross-sectional view of the sheet conveying device from a direction X shown in FIG. Sectional drawing of the sheet conveying apparatus regarding a comparative example. Sectional drawing of the sheet conveying apparatus regarding another comparative example.

Hereinafter, an embodiment using an electrophotographic printer as an image forming apparatus to which the present invention is applied will be described. First, the overall configuration and operation of the printer will be described.
FIG. 1 is a schematic configuration diagram of a printer according to the present embodiment.
The image forming unit 30 of the printer includes a charging device 32, a developing device 34, a transfer device 35, a photoconductor cleaning device 36, and the like around a photoconductor 31 as a latent image carrier. The image forming unit 30 also includes an optical writing unit (not shown) for irradiating the photoreceptor 31 with laser light 33, a fixing device 37 for fixing a toner image on the paper, and the like. Below the image forming unit 30, there is provided a sheet conveying apparatus 1 that stacks and stores sheets P for transferring images formed by the image forming unit and sequentially conveys the sheets P to be supplied to the image forming unit 30. Yes.

  In the image forming unit configured as described above, as the photoconductor 31 rotates, the surface of the photoconductor 31 is first uniformly charged by the charging device 32. Next, a laser beam 33 from an optical writing unit (not shown) based on the image data is irradiated to form an electrostatic latent image on the photoreceptor 31. Thereafter, a toner image is formed on the photosensitive member 31 by attaching toner with the developing device 34 to visualize the electrostatic latent image. On the other hand, the sheet conveying apparatus 1 separates and conveys the sheets one by one, puts them in the sheet conveying path 44, conveys them by the conveying roller 45 of the sheet conveying path 44, and abuts against the registration roller 46 to stop. Then, in synchronization with the toner image formation timing of the image forming unit 30, the paper P that is abutted against the registration roller 46 and stopped is sent to the transfer unit where the photoconductor 31 and the transfer device 35 face each other. In the transfer unit, the toner image on the photoreceptor 31 is transferred to the supplied sheet. The sheet on which the toner image has been transferred is discharged outside the apparatus after the toner image is fixed by the fixing device 37. On the other hand, the surface of the photoconductor 31 after the toner image transfer is cleaned by removing residual toner by the photoconductor cleaning device 36 to prepare for image formation again.

Next, the sheet conveying apparatus 1 which is a characteristic part of the printer of this embodiment will be described.
FIG. 2 is a side view illustrating a schematic configuration of the sheet conveying apparatus 1, and FIG. 3 is a top view illustrating a schematic configuration of the sheet conveying apparatus 1. As shown in FIG. 2, the sheet conveying apparatus 1 adsorbs the sheet storage unit 11, the sheet conveyance unit 12 above the sheet storage unit 11, and the uppermost sheet stored in the sheet storage unit 11 to the sheet conveyance unit 12. And a sheet suction part 13 for air suction.

  The sheet storage unit 11 has a bottom plate 19 that forms a horizontal surface 19A on which a plurality of stacked sheet bundles 2 are stacked. The bottom plate 19 is connected to lifting means 18 connected to a control unit (not shown), and the lifting means 18 drives the bottom plate 19 to move in the vertical direction by a signal from the control unit.

  The bottom plate 19 is moved by the elevating means 18 as follows. The sheet bundle is detected so that the downstream end of the sheet bundle 2 stacked on the bottom plate 19 is detected at the upper part on the downstream side (right side in FIG. 2) in the sheet conveyance direction (arrow A in FIG. 2) of the sheet storage unit 11. 2 is provided with a downstream end uppermost sheet detecting means 15 opposite the downstream end. Further, upstream sheet regulating means 16 is provided on the upstream side (left side in FIG. 2) of the sheet storage unit 11 so as to be movable in the sheet conveying direction and not to restrict the upstream end of the sheet. An upstream end uppermost sheet detecting unit 16 </ b> A that detects an upstream end of the sheet bundle 2 stacked on the bottom plate 19 is provided on the upper side of the upstream regulating unit 16. The downstream end uppermost sheet detecting means 15 is a non-contact type digital sensor such as a reflective optical photosensor, and is connected to a control unit (not shown). The stacked sheet bundle 2 is raised by driving the elevating means 18 to raise the bottom plate 19, and the downstream end uppermost sheet detecting means 15 detects the downstream end of the uppermost sheet 2A. As a result, the position of the stacked uppermost sheet 2A is detected, and the bottom plate 19 is raised and stopped by the elevating means 18 to the vertical position optimal for the suction of the uppermost sheet 2A by the air suction unit 13. The upstream end uppermost sheet detecting means 16A is a sensor of a type that recognizes the vertical position of the uppermost sheet 2A by detecting the rotation angle of the support arm, and is connected to a control unit (not shown). . Further, the elevating means 18 is provided with a detection unit 18A for detecting the drive amount, and it is possible to calculate the rising amount of the bottom plate 19 from the drive amount detected by the detection unit 18A and to calculate the number of stacked sheets. is there.

  The sheet suction transport unit 12 includes a sheet suction transport belt 12C as a sheet suction transport body stretched between two rollers 12A and 12B. The roller 12A is a drive roller, and is driven to rotate in the direction of the arrow in FIG. 2 by a belt drive motor 17 connected to a control unit (not shown), thereby moving the surface of the sheet adsorption transport belt 12C. Further, as shown in FIG. 3, the suction suction conveyance belt 12C is formed with a large number of suction holes 12D. In addition, a sheet suction unit 13 that sucks air from the suction holes 12D is provided in a space that is an inner periphery of the sheet suction conveyance belt 12C.

  The air suction unit 13 is connected to a control unit (not shown), and by sucking air from the suction hole 12D in response to a signal from the control unit, among the sheet bundles 2 stacked on the bottom plate 19, The uppermost sheet 2A is adsorbed to the outer peripheral surface of the sheet adsorbing and conveying belt 12C one by one. With the sheet 2A adsorbed on the outer peripheral surface of the sheet adsorption / conveyance belt 12C, the control unit (not shown) drives the belt drive motor 17 to move the surface of the sheet adsorption / conveyance belt 12C. In FIG. 2, the sheet is conveyed in the direction of a broken line arrow and sent to a sheet conveyance path 44 for supply to the transfer unit.

  In the sheet conveying apparatus 1, it is desirable that the air suction unit 13 described later adsorbs the sheet with a suction force that is as small as possible. By reducing the suction force, it is possible to reduce the influence of damage to the sheet and the noise and supply power of the sheet conveying apparatus 1. From such points, the optimum vertical position for the suction of the uppermost sheet 2A by the air suction unit 13 is determined.

  As shown in FIG. 3, the sheet storage unit 11 includes side regulating members 14 </ b> A and 14 </ b> B that regulate both ends of the stacked sheets, and the side regulating members 14 </ b> A and 14 </ b> B are orthogonal to the sheet conveyance direction. Can be moved to. The restricting members 14A and 15A are provided with an air blowing part 22 made of, for example, an axial fan, a sirocco fan, a cross flow fan, etc. It is the composition which performs. In FIG. 3, the air blower 22 is provided on the side regulating members 14 </ b> A and 14 </ b> B that regulate both ends of the sheet bundle 2, but may be provided only on one side of the side regulating member 14. Moreover, even if an air blowing part sprays from a downstream side edge part, you may spray from all the above-mentioned positions. The air blowing unit 22 is connected to a control unit (not shown), and allows the air volume to be adjusted by the control unit.

  4 is a cross-sectional view of the sheet conveying apparatus from the direction X shown in FIG. The side regulating member 14 </ b> A is provided with an air nozzle 23 that forms an opening for blowing air from the air blowing portion 22 to the side end portion of the sheet bundle 2 stacked on the bottom plate 19. An opening 25 through which air can pass is provided at a position near the air blowing nozzle 23 of the bottom plate 19. The air blowing nozzle 23 is arranged such that the opening lower end 23A is below the uppermost sheet 2A of the sheet bundle 2 and the opening upper end 23B is above the uppermost sheet 2A. The air nozzle 23 blows air from the substantially horizontal side of the sheet bundle 2 through the opening. In addition, as described above, the sheet conveying apparatus 1 detects the position of the uppermost sheet 2A by the downstream end uppermost sheet detecting means 15, and reaches the vertical position optimal for the suction of the uppermost sheet 2A by the air suction unit 13. The bottom plate 19 is raised by the lifting means 18 and stopped. When the number of sheets stacked on the bottom plate 19 decreases, the bottom plate 19 rises so that the bottom plate 19 is positioned above the lower opening 23A of the air nozzle 23 (state shown in FIG. 4). For this reason, the lower part of the air nozzle 23 is below the bottom plate 19, and the air generated by the air generator 22 is blown toward the bottom plate 19 in a substantially horizontal direction.

  Under the bottom plate 19, a flow path of air blown from the lower part of the air nozzle 23 toward the substantially horizontal direction below the bottom plate 19 is changed and guided to the opening 25 of the bottom plate 19. A flow path changing guide 24 as a guide member is provided. The flow path changing guide 24 guides the air blown downward from the bottom plate 19 to flow toward the opening 25 of the bottom plate 19, and blows the lowermost sheet 2 </ b> B loaded on the bottom plate 19 through the opening 25. . Thereby, a part of the air generated from the air generation part 22 can be sprayed from the lower side of the bottom plate 19 toward the lower surface of the lowermost sheet 2B. By blowing air from below, the lowermost sheet 2B is lifted from the bottom plate 19 and is easily adsorbed by the upper sheet adsorbing and conveying belt 12C. Accordingly, non-feeding of the lowest sheet 2B is suppressed. Thus, only the opening 25 of the bottom plate 19 and the flow path changing guide 24 for flowing air toward the opening 25 are provided, and it is not necessary to provide a new air generating part, and the structure is small and simple. .

  In FIG. 4, the air nozzle 23 and the flow path changing guide 24 and the opening 25 provided in the bottom plate 19 are shown on the regulating member 14A side, but the air blower 22 is provided on the 14B and the downstream end. Therefore, the air nozzle 23, the flow path changing guide 24, and the opening 25 may also be provided.

  Furthermore, by configuring the air blower 22 so that the air volume can be adjusted in accordance with the number of sheets to be loaded on the bottom plate 19, all the sheets can be floated more reliably. Thereby, it is possible to further improve the separation and conveyance performance from the uppermost sheet 2A to the lowermost sheet 2B. Specifically, the rising amount of the bottom plate 19 is calculated from the driving amount detected by the detecting unit 18A of the elevating means 18, the number of stacked sheets is calculated, and the air volume of the air blowing unit 22 is adjusted based on this. As a means for calculating the number of stacked sheets, it is possible to detect the position of the bottom plate 19 by using a distance measuring sensor or the like in addition to the detection unit 18A for detecting the driving amount of the elevating means 18.

  Further, by making it possible to adjust the air volume of the air blowing section 22 according to the sheet size to be stacked, the type of sheet, and the basis weight of the sheet, all the sheets can be floated more reliably.

Here, as a comparative example, means for suppressing non-feeding of the lowest sheet will be described in detail.
FIG. 5 shows that the air nozzle 23 is divided in the vertical direction, and the upper side blows air substantially in parallel to the sheet end so as to separate the sheets, and the lower side faces the sheet side so as to float the sheet. The shape of the nozzle is configured to blow air from obliquely below. Using an air nozzle having such a shape makes it easier to float the lowermost sheet with a simple configuration, but the effect is not sufficient depending on the characteristics of the sheet.
In FIG. 6, an air generating part such as a fan is separately provided below the bottom plate 19, an opening 25 through which air passes is provided in the bottom plate 19, and air is blown from the bottom of the bottom plate 19 toward the lowermost sheet lower surface. . In this configuration, as in the present invention, there is an effect that air is surely sent between the lowermost sheet lower surface and the stacking plate to float the lowermost sheet. However, as the number of fans increases, the size of the apparatus increases.
Compared to these comparative examples, the sheet conveying apparatus 1 of the present embodiment has an excellent effect that it is possible to effectively suppress non-feeding of the lowest-order sheet with a small and simple configuration.

  In the present exemplary embodiment, the present invention has been described using an electrophotographic printer as the image forming apparatus. However, the present invention is not limited to this, and the present invention can also be applied to an image forming apparatus such as a digital copying machine, a facsimile machine, or an offset printing machine. There are similar effects.

As described above, in the present embodiment, the bottom plate 19 that is a stacking plate for stacking a plurality of sheets and the uppermost sheet 2A that is placed above the sheets stacked on the bottom plate 19 are adsorbed to the surface and are themselves. The sheet suction conveyance belt 12C, which is a sheet suction conveyance body conveyed by the surface movement of the sheet, the sheet suction unit 13 for adsorbing the uppermost sheet 2A stacked on the bottom plate 19 to the sheet adsorption conveyance belt 12C by air suction, and the bottom plate 19 Lifting means 18 which is a moving means for moving the bottom plate 19 in the vertical direction so that the stacked uppermost sheet 2A takes a vertical position optimal for air suction by the sheet suction unit 13, and the sheets stacked on the bottom plate 19 An air generating unit 22 that generates air to be blown to the end of the sheet, and a sheet for blowing the air generated by the air generating unit 22 to the end of the sheet A sheet conveying apparatus 1 equipped with an air nozzle 23 provided to face the part. In this sheet conveying apparatus 1, when an opening 25 through which air can pass is provided in the bottom plate 19, and the bottom plate 19 is raised and lowered by the elevating means 18, the lower portion of the air nozzle 23 faces a position below the bottom plate 19. A flow path changing guide 24 is provided as a guide member for guiding the air blown from the lower part of the air nozzle 23 so as to flow toward the opening 25 of the bottom plate 19.
In this configuration, when the number of sheets stacked on the bottom plate 19 decreases, the bottom plate 19 is moved upward so that the uppermost sheet 2 </ b> A takes a vertical position optimal for air suction by the sheet suction unit 30. Due to the upward movement of the bottom plate 19, the lower part of the air nozzle 23 is opposed to the lower side of the bottom plate 19, and the air generated by the air generating unit 22 is blown downward from the bottom plate 19. The air blown downward from the bottom plate 19 is guided by the flow path changing guide 24 so as to flow toward the opening 25, and blown to the lower surface of the lowermost sheet 2 </ b> B stacked on the bottom plate 19 through the opening 25. Thereby, a part of the air generated from the air generation part 22 can be sprayed from the lower side of the bottom plate 19 toward the lower surface of the lowermost sheet 2B. By blowing air from below, the lowermost sheet 2B is lifted from the bottom plate 19 and is easily adsorbed to the upper sheet adsorbing and conveying belt 2C. Therefore, non-feeding of the lowest sheet is suppressed. Thus, only the opening 25 and the flow path changing guide 24 for flowing air toward the opening 25 are provided, and it is not necessary to provide a new air generation unit, and the configuration is small and simple.

  Further, according to the present embodiment, all the sheets can be floated more reliably by configuring so that the air volume of the air blower 22 can be adjusted according to the number of sheets stacked on the bottom plate 19. Thereby, it is possible to further improve the separation and conveyance performance from the uppermost sheet 2A to the lowermost sheet 2B.

  In addition, according to the present embodiment, all the sheets are floated more reliably by making it possible to adjust the air volume of the air blower 22 according to the sheet size to be stacked, the type of sheet, and the basis weight of the sheet. Can do.

  Further, according to the present embodiment, the image forming unit that forms a toner image on the photosensitive member, the sheet conveying unit that stacks, stores, and conveys a plurality of sheets, and the supplied sheet on the image carrier. In the image forming apparatus having the transfer means for transferring the toner image, by adopting the sheet conveying apparatus 1, various sheets are reliably separated and sequentially supplied to the transfer unit one by one, and the image is transferred. Can.

DESCRIPTION OF SYMBOLS 1 Sheet conveying apparatus 2 Sheet bundle 2A Uppermost sheet 2B Lowermost sheet 11 Sheet accommodating part 12 Sheet conveying part 12A Tension roller (driving roller)
12B Tension roller (driven roller)
12C Sheet Conveying Belt 12D Suction Hole 13 Sheet Suction Part 14 Side Restricting Member 15 Downstream End Uppermost Sheet Detection Unit 16 Upstream Side Sheet Restricting Unit 16A Upstream End End Uppermost Sheet Detection Unit 17 Belt Drive Motor 18 Lifting Unit 19 Bottom Plate
22 Air generating part 23 Air nozzle 23A Nozzle opening lower end 23B Nozzle opening upper end 24 Flow path changing guide 25 Opening part 30 Image forming part 31 Photoconductor 35 Transfer device 44 Paper conveying path 45 Conveying roller 46 Registration roller

JP 2007-045630 A

Claims (5)

A stacking plate for stacking a plurality of sheets, and a sheet adsorbing and transporting body that is disposed above the sheets stacked on the stacking plate and sucks the topmost stacked sheet to the surface and transports it by its own surface movement. A sheet suction unit for adsorbing the uppermost sheet stacked on the stacking plate to the sheet suction conveyance body by air suction, and the uppermost sheet stacked on the stacking plate is optimal for air suction by the sheet suction unit. Moving means for moving the stacking plate in the vertical direction so as to take a position in the vertical direction, an air generating unit for generating air to be blown to the end portion of the sheets stacked on the stacking plate, and generated by the air generating unit In a sheet conveying apparatus provided with an air nozzle provided to face the sheet end to blow the air to the sheet end stacked on the stacking plate,
When the loading plate is provided with an opening through which air can pass, and the loading plate is moved by the moving means, the lower portion of the air nozzle faces a position below the loading plate. A sheet conveying apparatus comprising: a guide member that guides air blown from below to flow toward an opening of the stacking plate.   2. The sheet conveying apparatus according to claim 1, further comprising a stacking plate position detecting unit that detects a vertical position of the stacking plate, and an air flow rate generated by the air generating unit based on a detection result of the stacking plate position detecting unit. A sheet conveying apparatus characterized by adjusting the angle.   3. The sheet conveying apparatus according to claim 1, wherein an air volume generated by the air generating unit is adjusted with respect to a stacked sheet size, sheet type, or sheet basis weight. .   An image carrier, an image forming unit that forms a visible image on the image carrier, a sheet conveyance unit that accommodates a plurality of sheets and conveys the contained sheets one by one, and the sheet conveyance unit 4. An image forming apparatus comprising: a transfer unit that transfers a visible image on the image carrier to a sheet conveyed by the step 1. The sheet conveying device according to claim 1, wherein the sheet conveying unit is a sheet conveying unit. An image forming apparatus.   5. The image forming apparatus according to claim 4, wherein the image forming apparatus is a digital copier, a printer, a facsimile machine, or an offset printing machine.

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