JP2010202373A - Paper feeder and image forming device - Google Patents

Abstract

A sheet such as a thin sheet can be reliably fed while suppressing the floating of the leading end of the sheet.
SOLUTION: Air is blown from a jet port 22 arranged on a side fence 13 in a paper storage unit to the side of a paper bundle in which air is stored, paper is blown, and paper is fed one sheet at a time by a pickup roller 31 from this paper bundle. In the sheet feeding device, the guide member 50 that guides the sheet fed by the transport device toward the transporting portion of the feed roller 32 and the reverse roller 33 is disposed on the sheet transport side of the pickup roller 31. The guide member 50 includes a snap-fit member retaining ring for fixing the pickup roller 31 to the shaft portion 31a and the feed roller 32 to the shaft portion 32a as the attachment portions 54 and 55, and when the mounting posture is incorrect, the pickup The roller 31 includes a shaft portion 32a and a convex portion 53 for buffering.
[Selection] Figure 1

Description

  The present invention relates to a sheet feeding device and an image forming apparatus, and in particular, blows a sheet from a jet outlet disposed on a side fence in a sheet storage unit to a side of a sheet bundle in which air is stored, performs sheeting, and picks up the sheet bundle from the sheet bundle. The present invention relates to a sheet feeding device that feeds sheets one by one and an image forming apparatus including the sheet feeding device.

  Various image forming apparatuses such as electrophotographic copying machines, printers, facsimiles, and ink jet printers are provided with a paper feeding device. This sheet feeding device takes out sheets one by one from a bundle of sheets stored in a sheet storage unit and feeds them to an image forming unit and a printing unit. In recent years, with the diversification of paper, paper other than plain paper, for example, coated paper, art paper, film paper, and the like have been used.

  Here, various types of paper other than plain paper have characteristics that the surface of the paper has good smoothness, low air permeability, and moisture absorption, so there is a tendency for the inter-paper adhesion to increase. For this reason, there is a problem that separability is poor compared to plain paper, and double feeding and non-feeding are likely to occur. When feeding various types of paper with these characteristics, the paper is fed one by one using a suction cup as in a conventional printing machine, or a feed roller is used as a belt. A sheet that uses negative pressure to suck paper by blowing air is used.

  In addition, a nozzle is provided on the upper part of the guide part that regulates the side edge or the rear edge of the paper, and the air sent from the blowing means such as a blower provided inside the guide part is blown to the upper end surface of the loaded paper. There are also things. Since this type of paper feeding device can send air between the stacked paper sheets, the stacked paper sheets can be blown with air to prevent double feeding.

  As an image forming apparatus provided with such a sheet feeding device, there is the following. FIG. 5 is a schematic diagram showing a configuration of an image forming apparatus provided with a paper feeding device to which the present invention is applied, and FIG. 6 is a perspective view showing an internal configuration of a conventional paper feeding device. As shown in FIG. 5, the image forming apparatus 1 includes an image forming apparatus main body 2 and a paper feeding device 5 connected to one side surface of the image forming apparatus main body 2.

  As shown in FIG. 6, the sheet feeding device 5 takes out a sheet feeding tray (sheet storage unit) 8 having a bottom plate 6 on which a sheet bundle is stacked and an uppermost sheet of the sheet bundle one by one. A paper feeding unit (paper feeding device) 9 for feeding paper to the main body 2 side. In the paper feeding unit 9, a pickup roller 31, a feed roller 32, and a reverse roller 33 are arranged. The pickup roller 31, the feed roller 32, and the reverse roller 33 are rotationally driven at respective preset sheet feeding timings.

  Further, in the paper feed tray 8, side fences 13 are provided on both sides for guiding side surfaces in the width direction (direction perpendicular to the paper feed direction) of the sheet bundle stacked on the bottom plate 6, and the rear side of the sheet bundle is behind. An end fence 14 that holds the end face is disposed. The upper limit of the sheet bundle is detected by a sensor 15 consisting of a photo interrupter. The sensor 15 detects the sheet feeding position, and the bottom plate is not always scattered even if the remaining amount of the sheet is low. The sheet feeding position is controlled by moving 6 up and down by a lifting motor M. In this way, in order to keep the paper feed separation condition constant, the paper upper limit position is always optimized so that the paper feed position is always constant even when the paper stacking amount increases or decreases.

The actuator 16 for operating the sensor 15 is connected to the pickup roller 31 and the feed roller 32, and the filler disposed at the end of the actuator 16 shields the sensor 15 so that the upper limit of the sheet is always reached. The position of the pickup roller 31 is kept constant. Further, even if the bottom plate 6 is raised in conjunction with the reduction of the sheet stacking amount, this position detection is performed by the actuator 16. The paper feed tray 8 is configured to be detachable from the paper feed device main body, and when the user sets paper in the paper feed tray 8, the paper feed tray 8 is pulled out.
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  FIG. 7 is a perspective view showing a main part of the paper feeding device shown in FIG. 6, and FIG. 8 is a schematic view showing a characteristic shape of the air jet outlet on the side fence surface. As shown in FIGS. 7 and 8, a blower fan 20 is attached to the outside of each side fence 13, and an air outlet (nozzle) 21 that blows out the air generated by the blower fan 20 opens to the side surface of the side fence. is doing. The air ejection port 21 is arranged at a position where the height of the upper edge 22 a is lower than the sheet passing path P of the sheet fed by the sheet feeding unit 9 and extends along the sheet passing path P. It has an outlet 22. Since air can be sent between the coated paper sheets loaded from the jet port 22, double feeding can be prevented.

  Patent Document 1 discloses a sheet stacking table that can be raised and lowered in order to improve the positional accuracy of various detection means such as a paper surface detection device with respect to the separation mechanism, to accurately perform various controls such as paper surface control and to reduce the cost of the device. And a paper surface detection device for detecting the height of the paper stacking base, a bearing member for supporting a rotating shaft of a feed roller as a holder member for holding at least a part of the paper surface detection device Are formed integrally.

  Further, in Patent Document 2, a sheet storage unit for stacking a plurality of sheets, a sheet feeding roller for taking out the sheet from the sheet storage unit, and the sheet fed by the sheet feeding roller, one by one. A sheet feeding device having a sheet feeding unit having separation rollers for feeding one by one to the image forming apparatus, wherein the separation roller and the sheet feeding roller are driven in both axial directions. The connecting member is disposed between a source and a separating means for separating and contacting the separating roller with respect to the sheet, and the separating means includes a connecting member for supporting the sheet feeding roller and the shaft of the separating roller. Describes the one that is rotatable about the drive shaft of the paper feed roller so that the separation roller side is raised.

  However, when air is fed between sheets of paper as in a conventional paper feeder, the leading edge of the paper may move above the target position in the case of thin paper coated paper, etc. It may collide with the top of the roller and cause non-feed.

  FIG. 9 is a perspective view showing the periphery of the roller of the paper feeding unit, and FIG. 10 is a side view of the main part of the paper feeding device showing a paper feeding problem. Here, a notch portion 42 for roller replacement is formed in the guide plate 41 disposed on the side of the pickup roller 31, the feed roller 32, and the reverse roller 33. When air is blown from the blower fan to the paper when the thin coated paper is passed by such a paper feeding device, air blows from the notch 42 to the side of the paper roller, and the leading edge Sa of the paper S is aimed. If the feed roller 32 and the reverse roller 33 are in contact with each other and the paper feed operation is performed in this state, the leading edge of the paper collides with the upper portion of the feed roller 32 as shown in FIG. It becomes a feed.

  For this reason, the guide plate 41 itself can be extended to restrict the paper floating, and the paper floating can be restricted by installing a roller or the like. However, the side of the roller where the paper is most likely to float is the reason described above. Since the guide plate cannot be installed, the floating of the paper cannot be regulated.

  SUMMARY An advantage of some aspects of the invention is that it provides a sheet feeding device that can reliably feed a sheet such as a thin sheet while preventing the leading edge of the sheet from rising, and an image forming apparatus including the sheet feeding device.

  According to the first aspect of the present invention, air is blown to the side of a bundle of sheets containing air from a jet port disposed on the side fence in the sheet storage unit, and the sheets are blown, and sheets are fed one by one from the sheet bundle by a pickup device. In the sheet feeding device, a guide member for guiding a sheet sent from the conveying device to a next-stage conveying device toward a carry-in portion is disposed on the sheet conveying side of the pickup roller.

  According to a second aspect of the present invention, in the paper feeding device according to the first aspect, the pickup device includes a pickup roller, and the next-stage transport device includes a feed roller and a reverse roller.

  According to a third aspect of the present invention, in the paper feeding device according to the second aspect, the guide member includes a shaft portion of the pickup roller and a mounting portion attached to the shaft portion of the feed roller.

  According to a fourth aspect of the present invention, in the paper feeding device according to the third aspect, the mounting portion of the guide member also serves as a snap-fit snap ring member that fixes the pickup roller and the feed roller to each shaft portion. Features.

  According to a fifth aspect of the present invention, in the paper feeding device according to any one of the second to fourth aspects, the guide member interferes with at least one shaft portion of the pickup roller or the feed roller when the mounting posture is incorrect. It is characterized by having a convex part.

  A sixth aspect of the present invention is an image forming apparatus comprising the paper feeding device according to any one of the first to fifth aspects.

  According to the paper feeding device and the image forming apparatus according to the present invention, since the guide member that guides the paper sent from the transport device toward the transport unit of the next stage is arranged on the paper transport side of the pickup roller, Therefore, it is possible to reliably feed paper such as thin paper.

It is a perspective view which shows the structure of the paper feeder which concerns on an Example. It is a side view which shows the structure of the paper feeder which concerns on an Example. It is a perspective view which shows the guide member provided in the paper feeder which concerns on an Example. It is a perspective view which shows the state which attached the guide member upside down. 1 is a schematic diagram illustrating a configuration of an image forming apparatus including a paper feeding device to which the present invention is applied. It is a perspective view which shows the internal structure of the conventional paper feeder. FIG. 3 is a perspective view illustrating a main part of the sheet feeding device illustrated in FIG. 2. It is a schematic diagram which shows the characteristic shape of the air jet nozzle in a side fence surface. FIG. 6 is a perspective view illustrating the periphery of a roller of a paper feeding unit. It is a principal part side view of the paper feeder which shows the malfunction of paper feed.

  According to the present invention, paper is blown to a side surface of a sheet bundle containing air from a jet port disposed on a side fence in a sheet storage unit, and a sheet is fed one by one by a pickup device from the sheet bundle. In the apparatus, a guide member for guiding the sheet sent out by the conveying device to the next conveying device on the paper conveying side of the pickup roller toward the carry-in portion is arranged. In the present invention, the pickup device includes a pickup roller, and the next-stage transport device includes a feed roller and a reverse roller. The guide member includes a shaft portion of the pickup roller and a mounting portion attached to the shaft portion of the feed roller. The mounting portion of the guide member also serves as a snap-fit snap ring member that fixes the pickup roller and the feed roller to each shaft portion, and when the guide member has an incorrect mounting posture, A convex portion that interferes with at least one shaft portion of the feed roller is provided.

  With such a configuration, according to the present invention, even if air is blown from the notch portion of the guide plate, the leading edge of the sheet at the portion corresponding to the notch portion is prevented from rising, and the non-feed is eliminated to ensure the sheet feeding. it can. Further, since the mounting portion of the guide member also serves as a snap-fit snap ring for the pickup roller and the feed roller, the number of parts can be reduced. Further, when the guide member is turned upside down and misassembled, the convex portion interferes with the axis of the pickup roller, so that the misassembly can be prevented. The image forming apparatus provided with this paper feeding device can improve the paper feeding performance of thin paper and the like, which are difficult to feed, and the conveyance quality is improved.

  Hereinafter, a sheet feeding device and an image forming apparatus according to the embodiment will be described. The paper feeding apparatus according to this example is applied to the image forming apparatus described as background art with reference to FIG. That is, the image forming apparatus according to this example is applied to each image forming apparatus such as an electrophotographic copying machine, a printer, a facsimile, and an ink jet printer having the above-described configuration.

  Further, the basic structure of the paper feeding apparatus according to this example is the same as that of the paper feeding apparatus described with reference to FIGS. The paper feeding device according to this example is applied to a paper feeding device that blows paper before feeding by blowing air from a jet port arranged on a side fence in a paper storage unit to the side of the paper bundle. In the sheet feeding device according to this example, a blower fan 20 is attached to the outside of each side fence 13, and an air outlet (nozzle) 21 that blows out the air generated by the blower fan 20 opens on the inner side surface of the side fence. ing. In addition, the air ejection port 21 is disposed at a position where the height of the upper edge 22 a is lower than the sheet passing path P of the sheet fed by the sheet feeding unit 9, and extends along the sheet passing path P. The nozzle 22 is provided. Air can be sent between the coated paper sheets loaded from the jet port 22 (see FIGS. 7 and 8).

  The paper feeding apparatus according to this example includes a pickup roller 31, a feed roller 32, and a reverse roller 33. A guide plate 41 is disposed on the side of these pickup roller 31, feed roller 32, and reverse roller 33. The plate 41 is provided with a notch 42 for roller replacement. The configuration up to here is the same as that of the paper feeding device described in the background art.

  1 is a perspective view illustrating a configuration of a paper feeding device according to the embodiment, FIG. 2 is a side view illustrating a configuration of the paper feeding device according to the embodiment, and FIG. 3 illustrates a guide member provided in the paper feeding device according to the embodiment. FIG. 4 is a perspective view showing a state where the guide member is mounted upside down.

  The paper feeding apparatus according to the present example includes a guide member 50, which guides the paper S with the guide member 50 to suppress the leading edge Sa of the paper S caused by blowing from the notch portion 42 of the guide plate 41, thereby eliminating non-feeding. is doing.

  As shown in FIG. 3, the guide member 50 is a bent member as a whole and is made of synthetic resin. The guide member 50 includes a curved guide plate portion 51 that protrudes downward when placed in the sheet feeding device, a projecting portion 52 disposed on one surface of the guide plate portion 51, and one end side of the projecting portion 52. The provided convex part 53 and the two attaching parts 54 and 55 standingly arranged from the guide plate part 51 are provided. The attachment portion 54 is formed in a substantially C shape so as to also serve as a snap fit retaining ring attached to the shaft portion 31a of the pickup roller 31. Similarly, the attachment portion 55 is provided with a snap fit retaining ring of the shaft portion 32a of the feed roller 32. It is formed in a substantially C shape so as to serve as both. Moreover, the convex part 53 will contact | abut to the axial part 31a when the up-down direction of the guide member 50 is mistakenly reversed, and will prevent attaching the attaching part 55 to the axial part 31a, and prevent incorrect attachment. The overall shape of the guide member 50 can be other shapes such as a linear shape, and a cross-sectional shape can be selected as appropriate.

  Therefore, according to the paper feeding device according to this example, even if the leading end Sa of the paper S tries to float due to blowing from the notch portion 42 of the guide plate 41 or for other reasons, as shown in FIG. It is pressed by the lower surface of the guide plate portion 51 and reliably conveyed between the feed roller 32 and the reverse roller 33, and non-feed is prevented. Further, according to the guide member 50 according to the present example, the mounting portions 54 and 55 also serve as snap-fit snap rings for the pickup roller 31 and the feed roller 32, so that individual snap-fit snap rings can be omitted and parts can be omitted. Can be made. In addition, since the convex portion 53 is arranged on the guide member 50, when the guide member 50 is turned upside down and misassembled, the convex portion 53 interferes with the shaft portion 31a of the pickup roller 31 to cause misassembly. Can be prevented.

  In addition, according to the image forming apparatus including the paper feeding device according to the embodiment, the paper feeding performance of thin paper or the like that is difficult to feed can be improved, and the conveyance quality of the device can be improved.

1: Image forming apparatus 2: Image forming apparatus main body 5: Paper feeder 6: Bottom plate 8: Paper feed tray (paper storage unit)
9: Paper feeding unit (paper feeding device)
13: Side fence 14: End fence 15: Sensor 16: Actuator 20: Blower fan 21: Air outlet (nozzle)
22: First ejection port 22a: Upper edge 31: Pickup roller 31a: Shaft portion 32: Feed roller 32a: Shaft portion 33: Reverse roller 41: Guide plate 42: Notch portion 50: Guide member 51: Guide plate portion 52: Protruding portion 53: convex portions 54, 55: mounting portion M: lifting motor P: paper passing path S: paper Sa: leading edge

JP 2001-310827 A Japanese Patent No. 40111847

Claims (6)

In a paper feeding device that blows paper to the side of a paper bundle containing air from a jet port disposed on a side fence in the paper storage unit, papers the paper, and feeds paper one by one from the paper bundle with a pickup device.
A sheet feeding device, wherein a guide member for guiding a sheet sent by a conveying device toward a carry-in unit is arranged in a next-stage conveying device on a sheet conveying side of a pickup roller.   The sheet feeding device according to claim 1, wherein the pickup device includes a pickup roller, and the next-stage transport device includes a feed roller and a reverse roller.   The sheet feeding device according to claim 2, wherein the guide member includes a shaft portion of the pickup roller and a mounting portion attached to the shaft portion of the feed roller.   The sheet feeding device according to claim 3, wherein the attachment portion of the guide member also serves as a snap-fit snap ring member that fixes the pickup roller and the feed roller to each shaft portion.   5. The paper feed according to claim 2, wherein the guide member includes a convex portion that interferes with at least one shaft portion of the pickup roller or the feed roller when the mounting posture is incorrect. apparatus.   An image forming apparatus comprising the paper feeding device according to claim 1.