JP2005178999A - Paper feeding device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of frictional electrification between the lowest paper sheet and a transfer plane when transferring paper sheets in a lump from a second paper storage part to a first paper storage part. <P>SOLUTION: This paper feeder comprises the first paper storage part for stacking the plurality of paper sheets, the second paper storage part arranged horizontal and parallel to the first paper storage part, and a paper transfer means for transferring the paper sheets in a lump from the second paper storage part to the first paper storage part. A frictional electrification preventing means is arranged on the paper transfer plane. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a paper feeding device provided in an image forming apparatus such as a copying machine, a printer, and a facsimile machine, and more particularly, in an image forming apparatus in which two paper storage portions are juxtaposed in a horizontal direction, The present invention relates to a paper feeding device that can prevent the occurrence of static electricity due to friction between the paper transport surface of a second paper storage unit and the bottom paper of the paper.

In image forming apparatuses such as copying machines, printers, and facsimile machines, in recent years, from the viewpoint of space saving, a paper storage unit such as a paper feed tray has been built in the apparatus main body, and a paper storage unit from the front side of the apparatus main body. A so-called front-loading type device that can be pulled out is widely used.
In order to further save space in this type of image forming apparatus, recently, a tandem type paper feeding apparatus in which paper storage portions are arranged in parallel in the horizontal direction has been developed.
As one of the methods, when a sheet in the first sheet storage unit runs out, a sheet bundle stored in the adjacent second sheet storage unit is collectively slid into the first storage unit.
As such a tandem type paper feeding device, for example, those disclosed in Patent Literature 1, Patent Literature 2, and the like are known. The former is automatically performed when it is detected that there is no sheet in the first sheet storage unit including the sheet feeding unit, and when it is detected that sheets are stacked in the adjacent second sheet storage unit. By moving the sheet bundle stored in the second sheet storage unit to the first sheet storage unit in a lump, it is possible to save the trouble of stopping the copying operation and replenishing the sheet.
Further, the latter is a lock mechanism that prohibits the second paper storage unit from being pulled out of the apparatus during a paper feeding operation from the first paper storage unit, and allows both storage units to be pulled out during a non-paper feeding operation. It is equipped with. In addition to the above, Patent Documents 3 to 6 disclose the above-mentioned dandem type paper feeding devices.
By the way, such a tandem type paper feeding device has a specific operation of loading and transferring a large amount of paper, so that due to the weight of the loaded paper, it is caused by the bending of the paper, especially by friction. Deterioration in transfer quality, such as sticking of paper to the bottom plate due to generated static electricity, is a problem.
Japanese Patent Laid-Open No. 3-195539 JP-A-6-144600 Japanese Patent Laid-Open No. 3-124633 JP-A-3-223031 Japanese Patent Application Laid-Open No. 9-077291 JP-A-9-202462

Any of the conventional tandem type paper feeding devices collectively moves the paper in the second paper storage unit toward the first paper storage unit when the paper in the first paper storage unit on the paper supply side runs out. For this purpose, a sheet transfer means is provided.
As described above, when the sheet transporting means is provided, the problem is that when the sheets are transported from the second sheet storage unit to the first sheet storage unit as described above, Due to static electricity generated at the time of transfer on the transfer surface of the two sheet storage units, the first sheet storage unit transfer surface and the bottom sheet of the sheet bundle stick together and have a close contact force, and the sheet feeding operation from the first sheet storage unit It is a point where trouble occurs.
In the prior art, there are also known sheets provided with an antistatic sheet in a sheet feeding stand or a sheet conveying device, but all of these problems are encountered when feeding one sheet at a time caused by the sticking of sheets due to static electricity. It is only for the purpose of preventing jamming, and the fact that the problem of preventing frictional electrification that occurs at the bottom paper and the transfer surface when the paper is collectively transferred has not been recognized so far. .
Accordingly, the present invention has been made in view of the above-described problems, and frictional charge generated on the lowermost sheet and the transfer surface when the sheets are collectively transferred from the second sheet storage unit to the first sheet storage unit. The purpose is to prevent problems at the time of paper transport by selecting materials having good slidability as well as preventing them.

In order to achieve the above object, the invention according to claim 1 is a first sheet storage unit for stacking a plurality of sheets, and a second sheet disposed horizontally and parallel to the first sheet storage unit. A sheet feeding device having a storage unit and a sheet transfer unit that collectively transfers the sheets of the second sheet storage unit to the first sheet storage unit. The most important feature.
According to a second aspect of the present invention, in the paper feeding device according to the first aspect, a main feature of the paper feeding device is that the antistatic means disposed on the paper transport surface of the second paper storage unit is an antistatic sheet.
According to a third aspect of the present invention, in the paper feeding device according to the first and second aspects, a main feature of the paper feeding device is that the sheet transport sliding surface of the antistatic means has a surface with good sliding properties.
According to a fourth aspect of the present invention, there is provided a first sheet storage unit for stacking a plurality of sheets, a second sheet storage unit disposed horizontally and in parallel to the first sheet storage unit, and the second sheet The most important feature of a paper feeding device including a paper transporting unit that collectively transports the paper in the storage unit to the first paper storage unit, is provided with a charge removal unit on the paper transfer surface.
According to a fifth aspect of the present invention, in the paper feeding device according to the fourth aspect, a main feature of the paper feeding device is that the discharging means disposed on the sheet transfer surface of the second sheet storage portion is a discharging brush.
According to a sixth aspect of the invention, an image forming apparatus including the paper feeding device according to any one of the first to fifth aspects is the main feature.

  According to the present invention, when the sheets are collectively transferred from the second sheet storage unit to the first sheet storage unit, frictional charging that occurs between the lowermost sheet and the transfer surface is prevented in advance. In addition, there is no adhesion due to static electricity between the lowermost paper and the transfer surface (bottom plate) of the first paper accommodating section, and the paper feeding quality of the lowermost paper can be stabilized.

The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a configuration diagram of an example of a copying machine which is an image forming apparatus provided with a sheet feeding device of the present invention.
A machine base 60 containing upper and lower two-stage sheet feeding devices 70 and 80 is provided at the lower part of the copying machine main body 50. Each of the sheet feeding devices 70 and 80 has a sheet feeding unit (such as a sheet feeding roller) 300 for feeding sheets one by one to the upper right end portion of the sheet storage unit, and the sheet fed by the sheet feeding unit 300 P is sent to the image forming unit 10 in the copying machine main body 50 via a common vertical conveyance path 90. In the copying machine main body 50, an image forming unit 10 and a reading optical system 20 are provided.
The image forming unit 10 includes a photoconductor 11, a charger 12, a developing device 13, a transfer / separator 14, a cleaning unit 15, a transport unit 16, a fixing unit 17, and the like. The reading optical system 20 includes a light source 21 that irradiates light on a document surface (not shown) on the contact glass 30, mirrors 22 and 23, a lens 24, and the like. The upper sheet feeding device 70 sets paper having a smaller size than that of the lower sheet feeding device 80. However, in order to eliminate the dead space caused by the small size paper, the small size paper is laterally (feeding direction lateral direction). ) Can be accommodated in parallel.
That is, the sheet storage unit for stacking and storing the sheets of the upper sheet feeder 70 is configured by the first and second sheet storage units 100 and 200, and each exists as an independent tray. When all the paper in the first paper storage unit 100 is consumed, the paper stored in the second paper storage unit 200 can be slid rightward and transferred into the first paper storage unit 100. Yes.
The first paper storage unit 100 can be pulled out integrally with the second paper storage unit 200 to the front side of the copying machine (front side of the drawing) (front loading type). Further, the second paper storage unit 200 can be pulled out to the front side of the copier alone or integrally with the first paper storage unit 100. When the second paper storage unit 200 is of a type that can be pulled out independently, only the second paper storage unit 200 can be pulled out during the paper feeding operation, and the paper is stored in the second paper storage unit 200 that has been pulled out. By performing the replenishment, it is possible to replenish paper during the paper feeding operation from the first paper storage unit 100, that is, during the operation of the copying machine, and endless paper feeding is possible.

FIG. 2 is an enlarged front view showing the configuration of the upper sheet feeder 70, and FIG. 3 is a plan view thereof. In the upper sheet feeder 70, the upper side of the sheet feeding side (right side in the figure) of the first sheet storage unit 100 is shown. A paper feeding means 300 is provided. The sheet feeding means 300 includes a pickup roller 301, separation roller pairs 302 and 303, and a paper end detection sensor 304. The paper end detection sensor 304 detects the presence / absence of a sheet raised to a paper feeding position by a bottom plate lifting / lowering device described later.
The first paper storage unit 100 includes a pair of opposing side fences 101a and 101b that guide both sides of the paper in the width direction, a bottom plate 102 for placing paper, and a pair of paper for holding the trailing edge of the loaded paper. It consists of end fences 105 and 106. The end fence pair 105 is assembled to each of the side fences 101a and 101b. In the case of the end fence 105 shown in the enlarged view of the main part of FIG. 4, the end fence pair 105 includes two parts, a guide 105a and a main body 105b. The rear end of the main body 105b (the rear end in the paper transport direction) is bent inward in an L shape to form a paper pressing portion 105c. And the long hole 105a-1 formed in extension part 105a 'of the lower end part of the guide 105a is fitted by the boss | hub 103a-1 provided in the edge part of the rack 103a. An extension portion 105a ′ is attached to the lower end portion of the shaft portion 105d provided at one end of the guide 105a.
The rack 103a is engaged with a pinion gear p of a stepping motor (not shown), and the rack 103a slides in the longitudinal direction by the rack and pinion mechanism. As a result, the end fence 105 rotates about the shaft portion 105d that is an assembly portion to the side fence 101a. When the rack 103a moves to the lower left in the figure, the end fence 105 rotates clockwise around the shaft part 105d in the figure, and the sheet pressing part 105c is located outside the side fence 101a (outside the sheet placing part). evacuate. When the rack 103a moves to the upper right in the drawing from the retracted state, the end fence 105 rotates counterclockwise in the drawing, and the sheet pressing portion 105c returns to the inside of the side fence 101a and the rear of the sheet on the bottom plate 102 is reached. Hold the edge. The other end fence 106 is similarly configured (symmetrically with the end fence 105 with the sheet placement portion interposed therebetween), and is also attached to the side fence 101b by the forward and backward movement of the rack 103b in the longitudinal direction. It turns around a certain shaft part. By rotating the end fences 105 and 106, the trailing edge of the loaded paper is pressed and the presser is released.

When the paper P1 in the first paper storage unit 100 is consumed, the paper P2 stored in the second paper storage unit 200 is transferred into the first paper storage unit 100, but in that case, it is not illustrated. The stepping motor is driven, the end fence 105 is rotated by the rack and pinion mechanism, and the bent portion of the end fence is retracted to the outside of the side fences 101a and 101b. Then, the rear end of the first paper storage unit 100 in the paper transport direction is opened and retracted from the paper transport area. 2 and 3, the back fence (pressing plate) 202 of the second paper storage unit 200 slides to the right, and the paper P2 placed on the paper placement plates 209a, 209b, and 209c is changed to the first paper. Transfer to container 100. When the transfer of the paper is completed, the end fence 105 rotates in the reverse direction by the reverse rotation of the stepping motor, and supports the rear end of the paper set on the paper placement plate 102 of the first paper storage unit 100.
As shown in FIG. 5, the bottom plate lifting / lowering device unit 800 has a compression spring 802 and a coupling 803 attached to the output shaft of a bottom plate lifting / lowering motor 801 capable of forward and reverse rotation, and the coupling 803 can slide in the output shaft direction. It has become. A pin 806 provided on the pressure shaft 804 is engaged with the coupling 803, and the pressure shaft 804 is rotated forward and backward by the bottom plate lifting / lowering motor 801. A pressure plate 805 is fixed to the pressure shaft 804.
As shown in FIG. 3, the pressure shaft 804 and the pressure plate 805 extend below the bottom plate 102 of the first paper storage unit 100 and are supported. When the pressure shaft 804 rotates counterclockwise, the pressure plate 805 lifts the bottom plate 102 from below, and the stack of sheets stacked on the bottom plate is urged upward on the feeding side, and the uppermost sheet is moved. It contacts the pickup roller 301.

As shown in FIG. 6, an antistatic sheet 400 is attached to the sheet stacking surfaces of the sheet stacking plates 209a, 209b, and 209c in the second sheet storing unit and the sheet stacking plate 102 in the first sheet storing unit. . The antistatic sheet 400 is made of a material having good slidability so as not to hinder the quality of sheet transfer from the second sheet storage unit to the first sheet storage unit.
Further, FIG. 6 shows an example in which a static eliminating brush is arranged on the sheet transfer surface. A neutralizing brush 250 is disposed on the first paper storage portion side of the paper placement plates 209a, 209b, and 209c. The angle α of the brush portion of the static elimination brush needs to be less than 90 degrees (acute angle) so as not to cause a load of paper transfer. Of course, it is essential that the neutralizing brush is securely grounded.
According to the present invention, by selecting a material having good sliding property for the sliding surface of the antistatic sheet for preventing frictional charging, it is possible to prevent paper transport problems and stabilize paper transport quality. Can do.
Furthermore, by configuring as described above, static electricity can be removed more positively by disposing a neutralizing brush in the middle of a transfer path for collectively transferring paper from the second paper storage unit to the first paper storage unit. As a result, there is no adhesion due to static electricity on the transfer surface (bottom plate) of the bottom sheet and the first sheet storage unit, and the sheet feeding quality of the bottom sheet can be stabilized.

1 is a configuration diagram of an example of a copying machine that is an image forming apparatus including a sheet feeding device according to the present invention. FIG. 3 is an enlarged front view showing the configuration of the paper feeding device of the present invention. The top view of FIG. FIG. 3 is an exploded perspective view of a main part of the paper feeding device in FIG. 2. FIG. 3 is an exploded perspective view of a main part of the paper feeding device in FIG. 2. Explanatory drawing of the example which has arrange | positioned the static elimination brush on the paper conveyance surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming part, 12 Charger, 13 Developer, 14 Transfer / separator, 15 Cleaning unit, 16 Conveying means, 17 Fixing means, 20 Reading optical system, 50 Copying machine main body, 60 units, 70, 80 Paper feeding Apparatus, 90 vertical conveyance path, 100 first paper storage unit, 102 bottom plate, 105, 106 end fence, 200 second paper storage unit, 201 back fence, 203 DC motor, 300 paper feeding means, 301 pickup roller, 302 , 303 Separating roller pair, 304 Paper end detection sensor, 800 Bottom plate lifting device, 801 Bottom plate lifting motor, 802 Compression spring, 803 Coupling, 804 Pressure shaft

Claims (6)

  A first sheet storage unit for stacking a plurality of sheets, a second sheet storage unit disposed horizontally and parallel to the first sheet storage unit, and a sheet in the second sheet storage unit as a first sheet A sheet feeding apparatus comprising a sheet transporting unit that collectively transports to a storage unit, wherein an antistatic unit is disposed on a sheet transporting surface.   2. The sheet feeding device according to claim 1, wherein the antistatic means disposed on the sheet transfer surface of the second sheet accommodating portion is an antistatic sheet.   3. A sheet feeding apparatus according to claim 1, wherein the sheet transfer sliding surface of the antistatic means has a surface having good sliding properties.   A first sheet storage unit for stacking a plurality of sheets, a second sheet storage unit disposed horizontally and parallel to the first sheet storage unit, and a sheet in the second sheet storage unit as a first sheet A sheet feeding apparatus comprising a sheet transporting unit that collectively transports to a storage unit, wherein a charge eliminating unit is disposed on a sheet transporting surface.   5. The paper feeding device according to claim 4, wherein the static elimination means disposed on the paper transport surface of the second paper storage unit is a static elimination brush.   An image forming apparatus comprising the paper feeding device according to claim 1.

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