JP2005343669A - Sheet material feeding method, sheet material feeder and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide sheet material feeding method and device, preventing adhesion of filling material and paper dust of a sheet material by releasing electric charges from a conductive material when electrostatic electricity is generated by rubbing between an inclined member and a sheet material feeding member to apply electric charges to the outer peripheral surface of the sheet material feeding member. <P>SOLUTION: This sheet material feeder includes: a feeding means 4 brought into pressure contact with the sheet material 2 stored in a sheet material loading member 1 to deliver the sheet material 2 to a separating part; and an inclined member 6 having a slant face 9 on which the leading edge of the sheet material 2 in the delivery direction abuts. The inclined member 6 forms an abutting part 12 to the feeding means 4 like a projection along the axial direction of the feeding means 4, and the tip of the slant face 9 abuts on the feeding means 4 at the edge thereof. In this sheet material feeding method, the delivered sheet materials 2 are separated and transported by the slant face 9 of the inclined member 6 and the nip forming part. In the method, a conductive material 19 is made close to or brought into contact with the surface of the feeding means 4, and the conductive material 19 is grounded. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet material feeding method for separating and feeding stacked sheet materials one by one, an apparatus therefor, and an image forming apparatus including the sheet material feeding method.

2. Description of the Related Art Conventionally, a sheet material feeding device that presses a sheet material accumulated in a sheet material stacking member and separates and feeds the stacked sheet materials one by one at a separation unit has been known (for example, Patent Documents). 1 and 2).
JP-A-8-91612 JP 2003-26348 A

The sheet material feeding device presses the sheet material accumulated in the sheet material stacking member, feeds the sheet material to the separation unit, presses the sheet material, and the leading end of the sheet material feeding direction is And an inclined member having an inclined surface that abuts.
The inclined member forms a contact surface with the feeding means in a protruding shape along the axial direction of the feeding means, and the tip of the inclined surface is in contact with the feeding means at the edge. The sheet material is fed to the separation unit by the feeding unit, and the fed sheet material is separated by the inclined surface of the inclined member and the nip forming unit.
In such a sheet material feeding apparatus, when continuous feeding is performed in a low-temperature and low-humidity environment, the feeding unit may slip, and non-feeding may occur due to exceeding a predetermined feeding time.
As a condition for the occurrence of the slip, the material of the inclined member is usually formed of resin, and the material is PE. In particular, the sheet is more susceptible to static electricity due to rubbing with the feeding means than other resin members, and the sheet. When the material is high-quality paper and the amount of filler is abnormally large, the feeding means is charged by the generated static electricity.
In addition, when the feeding means is non-conductive, electric charges are likely to accumulate, and the filler adheres to the feeding means, and slippage occurs due to the filler being interposed between the feeding means and the sheet material when the next sheet material is fed. Will occur.
The material of the inclined member is selected as PE because the wear of the inclined member due to rubbing with the sheet material is low, and the generation of sliding noise due to rubbing with the sheet material is also more slidable than other resin materials. This is because the generated sound is lowered.
The object of the present invention is to take into account the above-mentioned situation, when static electricity is generated by rubbing between the inclined member and the sheet material feeding member, and the outer peripheral surface of the sheet material feeding member is charged, the electric charge is charged from the conductive material. An object of the present invention is to provide a sheet material feeding method and apparatus in which the filler, paper powder, etc. of the sheet material do not adhere by escaping.

In order to solve the above problems, the invention according to claim 1 is directed to a feeding unit that presses the sheet material accumulated in the sheet material stacking member and feeds the sheet material to the separation unit, and the feeding unit. And an inclined member having an inclined surface against which the leading end of the sheet material abuts against, and the inclined member has a projecting shape along the axial direction of the feeding means at the contact portion with the feeding means And the tip of the inclined surface is in contact with the feeding means at the edge, the sheet material is fed to the separating portion by the feeding means, and the fed sheet material is fed to the inclined surface of the inclined member and The sheet material feeding method for separating and conveying by a nip forming portion is characterized in that the sheet material feeding method is such that a conductive material is brought close to or in contact with the surface of the feeding means and the conductive material is grounded.
According to a second aspect of the present invention, there is provided a feeding unit that press-contacts the sheet material accumulated in the sheet material stacking member and feeds the sheet material to the separation unit, and press-contacts the feeding unit, An inclined member having an inclined surface against which a leading end in the feeding direction abuts, and the inclined member forms a contact portion with the feeding unit in a protruding shape along the axial direction of the feeding unit, and the inclined surface The leading end is in contact with the feeding means at the edge, the sheet material is fed to the separation unit by the feeding unit, and the fed sheet material is separated and conveyed by the inclined surface of the inclined member and the nip forming unit. The sheet material feeding device is characterized by a sheet material feeding device having a conductive material that is in contact with or in contact with the surface of the feeding means.
According to a third aspect of the present invention, there is provided an image forming apparatus comprising: the sheet material feeding device according to the second aspect; and image forming means for forming an image on the sheet material fed from the sheet material feeding device. It is characterized by.

  According to the present invention, the charge charged to the feeding means is released, so that the deposits such as the filler on the feeding means surface are eliminated, and the feeding means is prevented from slipping, thereby stabilizing the feeding quality. I can plan.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic vertical sectional view showing an embodiment of an image forming apparatus configured as a printer. The image forming apparatus main body 30 includes a sheet material feeding device 20, a registration unit 17 that performs registration adjustment of an image forming position with respect to the sheet material 2 fed from the sheet material feeding device 20, and a sheet material. 2 is provided with image forming means 21 for forming an image.
First, the configuration and operation of the registration unit 17 and the image forming unit 21 will be described. In the registration means portion 17 of this embodiment, the registration sensor 18 detects the leading edge of the sheet material 2. The sheet material 2 is conveyed by a predetermined amount by the sheet material feeding device 20.
At that time, when the sheet material feeding device 20 is stopped, the registration roller (registration unit) 17 and the opposing roller 16 are stopped at this time, and the leading edge of the sheet material 2 fed out is located between the registration roller 17 and the opposing roller 16. It hits the nip.
By feeding a predetermined amount by the sheet material feeding device 20, a slack is formed at the front end of the sheet material 2, and when the full width of the front end of the sheet material 2 abuts against the registration roller 17, the skew of the sheet material 2 is corrected. Is done.
As a result, when the sheet material 2 is conveyed to the image forming unit including the image forming means 21 by driving the registration roller 17 at the time of image formation, the timing of the image forming position can be achieved.

Further, in the image forming section of the present embodiment, the image forming means 21 has a drum-shaped photoconductor 22, and this photoconductor 22 is rotationally driven counterclockwise in FIG. 1 during an image forming operation.
At this time, the surface of the photosensitive member 22 is charged to a predetermined polarity by a charging roller 23 which is an example of a charging device, and a light-modulated laser beam emitted from the exposure device 24 is applied to the surface of the charged photosensitive member 22. L is irradiated, whereby an electrostatic latent image is formed on the surface of the photoreceptor 22.
This electrostatic latent image is visualized as a toner image by the developing device 25. A transfer roller 26, which is an example of a transfer device, is disposed facing the photoconductor 22, and the sheet material 2 fed from the sheet material feeding device 20 in the direction of arrow A in a manner described later is transferred to the photoconductor 22. The toner image on the photosensitive member 22 is transferred to the sheet material 2 through the transfer portion between the roller 26 and the roller 26.
The transfer residual toner that is not transferred to the sheet material 2 and adheres to the photosensitive member 22 is removed by the cleaning device 27. Further, the sheet material 2 that has passed through the transfer section passes through the fixing device 28 as indicated by an arrow B, and at this time, the toner image on the sheet material 2 is fixed to the sheet material by the action of heat and pressure.
The sheet material 2 that has passed through the fixing device 28 is discharged to a paper discharge unit 29. As described above, a predetermined image is formed by the image forming means 21 on the sheet material 2 fed from the sheet material feeding device 20.

FIG. 2 is a perspective view showing a sheet material feeding device of the printer of FIG. On the other hand, as shown in FIGS. 1 and 2, the sheet material feeding device 20 includes a main body case 10 through a box-shaped main body case 10 having an open upper portion and an opening 10 b formed in the rear portion of the main body case 10. The cassette 11 is detachably mounted inside.
In the cassette 11, a sheet material stacking member 1 generally called a bottom plate is disposed, and holes formed in the ear portion 1 a projecting from the rear end side project from each side wall 11 b of the cassette 11. The pin 11a is rotatably fitted.
Further, as shown in FIG. 1, a compression spring 3 is disposed between the front end side of the sheet material stacking member 1 and the bottom wall 11c of the cassette 11, so that the front end side of the sheet material stacking member 1 faces upward. It is energized.
A shaft 8 shown in FIGS. 1 and 2 is rotatably supported by the main body case 10, and a sheet material feeding member 4 configured as a feeding roller made of an elastic body is attached to the shaft 8. On the other hand, it is fixed concentrically.
FIG. 3 is a schematic diagram for explaining a state in which the leading end portion X of the uppermost sheet material of the sheet material stacked on the sheet material stacking member is in pressure contact with the outer peripheral surface of the sheet material feeding member. As shown in FIGS. 1 and 3, the sheet material 2 described above is stacked on the sheet material stacking member 1.
When the sheet material stacking member 1 is biased upward by the compression spring 3, as shown in FIG. 3, the front end side portion X of the uppermost sheet material 2a of the sheet material 2 stacked on the sheet material stacking member 1 is shown. Is in pressure contact with the outer peripheral surface of the sheet material feeding member 4. Hereinafter, this portion is referred to as a pressure contact portion X.

In the present embodiment, the uppermost sheet material 2a is made of paper or a resin sheet. As will be described later, the uppermost sheet material 2a is sent in the direction indicated by the arrow S in FIG. 3 as the sheet material feeding member 4 rotates, but downstream of the above-described pressure contact portion X in the sheet material conveyance direction. On the side, an inclined member 6 having an inclined surface 9 is arranged.
The portion indicated by reference numeral 12 of the inclined member 6 is in pressure contact with the outer peripheral surface of the sheet material feeding member 4 by the biasing action of the compression spring 5 (FIGS. 1 and 2). Hereinafter, this portion is referred to as a pressure contact portion 12.
As described above, the inclined member 6 includes the press contact portion 12 that presses against the outer peripheral surface of the sheet material feeding member 4, and the portion on the upstream side in the sheet material feeding direction from the press contact portion 12 is configured as the inclined surface 9. Has been. Further, as shown in FIG. 2, protrusions 13 protruding from the respective side surfaces of the inclined member 6 are slidably fitted to guide rails 7 provided in the main body case 10.
Accordingly, the inclined member 6 is supported so as to be movable in a direction in which the inclined member 6 is in contact with or separated from the outer peripheral surface of the sheet material feeding member 4, that is, in a direction in which the inclined member 6 approaches or separates from the outer peripheral surface. The pressure contact portion 12 of the inclined member 6 is in pressure contact with the outer peripheral surface of the sheet material feeding member 4 by a compression spring 5 disposed between the feeding member 4 and the main body case 10.
A pair of hooks 15 are provided at the lower part of the inclined member 6, and when these engage with a locking portion (not shown) of the main body case 10, the inclined member 6 moves above its highest position. As a result, separation from the main body case 10 is prevented.
As can be seen from FIG. 2, the pressure contact portion 12 of the inclined member 6 extends in the axial direction of the sheet material feeding member 4 made of a feeding roller, and its width W is narrower, so that the sheet material is fed out than the pressure contact portion 12. The portion 14 of the inclined member 6 on the downstream side in the direction is separated from the outer peripheral surface of the sheet material feeding member 4.
It is also possible to divide the pressure contact portion 12 into a plurality of the sheet material 2 a in the feeding direction S, and to press these pressure contact portions 12 to the outer peripheral surface of the sheet material feeding member 4. Further, as shown in FIG. 3, the sheet material stacked on the sheet material stacking member 1 is pressed against the outer peripheral surface of the sheet material feeding member 4, and the pressure contact portion 12 of the inclined member 6 is the sheet material feeding member. The distance LS along the sheet material feeding direction S between the portion 4 and the portion in pressure contact with the outer peripheral surface is set to a short distance of about 2 mm to 6 mm.

Furthermore, when the friction coefficient of the outer peripheral surface of the sheet material feeding member 4 with respect to the sheet material 2 is μ1, the friction coefficient between the sheet materials is μ2, and the friction coefficient of the pressure contact portion 12 of the inclined member 6 with respect to the sheet material 2 is μ3, μ1>μ2> μ3 is set. If the inclined member 6 is made of resin, the coefficient of friction of the inclined member 6 with respect to the sheet material 2 can be reliably lowered.
When a feeding signal is issued from a control unit (not shown), a motor (not shown) starts to operate, and the sheet material feeding member 4 including the shaft 8 and a feeding roller fixed thereto is shown in FIG. And it is rotationally driven counterclockwise in FIG.
As a result, the outer peripheral surface of the sheet material feeding member 4 is moved, so that the uppermost sheet material 2 a pressed by the compression spring 3 and pressed against the outer peripheral surface of the sheet material feeding member 4 becomes the sheet material feeding member 4. It is sent out in the direction of arrow S shown in FIG.
FIG. 4 is a schematic view showing a state in which the leading end portion X of the uppermost sheet material of the sheet material stacked on the sheet material stacking member hits the inclined surface of the inclined member. In this way, the sheet material feeding member 4 is pressed against the sheet material 2a loaded on the sheet material stacking member 1 at its outer peripheral surface, and sends out the sheet material 2a pressed against the outer peripheral surface by movement of the outer peripheral surface. To help.
Next, as shown in FIG. 4, the leading end of the sheet material 2 a sent out abuts against the inclined surface 9 of the inclined member 6. At this time, the angle θ2 formed between the inclined surface 9 of the inclined member 6 and the feeding direction of the sheet material 2 is such that the tip of the sheet material 2a that has abutted against the inclined surface 9 is guided to the inclined surface 9 as shown in FIG. Therefore, it is set at an acute angle so that it can move toward the pressure contact portion 12. This angle θ2 is preferably 50 ° to 70 °.

FIG. 5 is a schematic view showing a sheet material passing between the outer peripheral surface and the pressure contact portion of the inclined member while receiving a frictional force from the outer peripheral surface of the sheet material feeding member. As described above, the uppermost sheet material 2a guided to the press contact portion 12 receives the frictional force from the outer peripheral surface of the sheet material feeding member 4 as shown in FIG. It passes between 6 pressure contact parts 12.
The inclined member 6 is separated from the outer peripheral surface of the sheet material feeding member 4 by a distance corresponding to the thickness of the uppermost sheet material 2a, and this is subjected to frictional force from the outer peripheral surface of the sheet material feeding member 4. The sheet material 2a passes through.
At this time, as described above, since the friction coefficients μ1, μ2, and μ3 are set such that μ1>μ2> μ3, the uppermost sheet material 2a is hindered by the frictional force received from the sheet material feeding member 4. Without being sent out from the cassette 11, it passes through the portion of the pressure contact portion 12.
Next, as described above with reference to FIG. 1, the sheet material 2a is conveyed to a transfer portion between the photoconductor 22 and the transfer roller 26. At this time, the toner image on the photoconductor 22 is transferred to the sheet material. Transferred onto 2a. According to the sheet material feeding device 20 described above, the uppermost sheet material 2a among the plurality of sheet materials 2 stacked on the sheet material stacking member 1 is separated from other sheet materials, for example, 2b and 2c. Only the uppermost sheet material 2a can be fed.
The operation at this time will be clarified with reference to FIG. 4 and FIG. As shown in FIG. 4, when the tip of the uppermost sheet material 2a hits the inclined surface 9 of the inclined member 6, the force exerted by the sheet material 2a on the inclined surface 9 is F, and the inclined surface 9 of this force F F1 is a component force in a direction perpendicular to the angle F1, and F2 is a component force in a direction along the inclined surface 9.
Further, if the compression spring 3 shown in FIG. 1 presses the inclined member 6 against the outer peripheral surface of the sheet material feeding member 4 as a separation pressure Q, the direction of action of the separation pressure Q is the same as the sheet material 2a feeding direction. The angle indicated by θ1 is formed.
Therefore, the pressure contact portion 12 of the inclined member 6 is shown in FIG. 5 by setting the separation pressure so that the separation pressure Q is smaller than the component F1α of the component force F1 along the acting direction of the separation pressure Q. Thus, the sheet material 2a is separated from the outer peripheral surface of the sheet material feeding member 4 by a distance substantially corresponding to the thickness of the sheet material 2a, and the sheet material 2a passes therethrough.

On the other hand, when the next sheet material 2b in contact with the uppermost sheet material 2a as shown in FIG. 5 is fed together with the sheet material 2a by the frictional force received from the uppermost sheet material 2a, The front end of the sheet material 2b hits the inclined surface 9 of the inclined member 6, and a force Fp is applied to the inclined surface 9. This force Fp is also divided into a component force Fp1 in a direction perpendicular to the inclined surface 9 of the inclined member 6 and a component force Fp2 in a direction along the inclined surface 9 to generate a component Fp1α opposite to the separation pressure Q.
However, generally, the frictional force acting between the sheet materials 2 is small and is, for example, about 50% of the frictional force acting between the outer peripheral surface of the sheet material feeding member 4 and the sheet material 2. For this reason, the force Fp1α is also very small, and the inclined member 6 can be prevented from being separated from the outer peripheral surface of the sheet material feeding member 4 larger than the thickness of the uppermost sheet material 2a.
For this reason, the next sheet material 2 b is stopped by the inclined surface 9, and is not fed beyond the press contact portion 12. The same applies when the sheet material 2c below the next sheet material 2b is fed together and hits the inclined surface 9.
As described above, the illustrated sheet material feeding device 20 can feed only the uppermost sheet material 2 a among the stacked sheet materials 2. In addition, since the friction coefficient of the pressure contact portion 12 with respect to the sheet material 2a can be reduced, the sheet material 2 conveyed between the pressure contact portion 12 of the inclined member 6 and the outer peripheral surface of the sheet material feeding member 4 performs stick slip. The trouble which raises can be prevented and generation | occurrence | production of abnormal noise can be suppressed effectively.

A first embodiment of the present invention will be described with reference to FIGS. The conductive material 19 is brought close to or in contact with the outer periphery of the sheet material feeding member 4, and the conductive material 19 is grounded 32 outside the apparatus via the conductive wire material 31.
As the conductive material 19, a neutralizing brush or a neutralizing cloth is usually used. When static electricity is generated by rubbing between the inclined member 6 and the sheet material feeding member 4 and the outer peripheral surface of the sheet material feeding member 4 is charged, the charge of the sheet material 2 is released by releasing the charge from the conductive material 19. Paper dust does not adhere.
The present invention can also be applied to various types of image forming apparatuses other than the form shown in FIG. 1 or sheet material feeding apparatuses thereof, for example, a plurality of sheet material feeding units each accommodating sheet materials of different sizes. The present invention can be widely applied to an image forming apparatus having a feeding apparatus, an image forming apparatus including a copying machine, a facsimile machine, a printing machine, or a multifunction machine, or a sheet material feeding apparatus thereof.

1 is a schematic vertical sectional view showing an embodiment of an image forming apparatus configured as a printer. FIG. 2 is a perspective view illustrating a sheet material feeding device of the printer of FIG. 1. FIG. 5 is a schematic diagram illustrating a state in which a front end portion X of the uppermost sheet material of the sheet material stacked on the sheet material stacking member is in pressure contact with the outer peripheral surface of the sheet material feeding member. Schematic which shows the state which the front end part X of the uppermost sheet | seat material of the sheet | seat material loaded on the sheet | seat material stacking member contacts the inclined surface of an inclination member. Schematic which shows the sheet material which passes between between an outer peripheral surface and the press-contact part of an inclination member, receiving a frictional force from the outer peripheral surface of a sheet material feeding member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sheet material stacking member, 2 Sheet material, 2a Topmost sheet material, 4 Feeding means (sheet material feeding member, feeding roller), 6 Inclined member, 9 Inclined surface, 12 Contact part of inclined member (Press contact) Part), 19 Conductive material, X pressure contact part

Claims (3)

  A feeding unit that presses the sheet material accumulated in the sheet material stacking member and feeds the sheet material to the separation unit, and an inclined member that is in pressure contact with the feeding unit and has an inclined surface against which the leading end of the sheet material abuts. The inclined member is formed in a protruding shape along the axial direction of the feeding means, the tip of the inclined surface is in contact with the feeding means at the edge, In the sheet material feeding method in which the sheet material is fed to the separation unit by the feeding unit, and the fed sheet material is separated and conveyed by the inclined surface of the inclined member and the nip forming unit, the sheet material is provided on the surface of the feeding unit. A sheet material feeding method, wherein a conductive material is brought close to or in contact with the conductive material, and the conductive material is grounded.   A feeding unit that presses the sheet material accumulated in the sheet material stacking member and feeds the sheet material to the separation unit, and an inclined member that is in pressure contact with the feeding unit and has an inclined surface against which the leading end of the sheet material abuts. The inclined member is formed in a protruding shape along the axial direction of the feeding means, the tip of the inclined surface is in contact with the feeding means at the edge, In the sheet material feeding apparatus that feeds the sheet material to the separation unit by the feeding unit and separates and conveys the fed sheet material by the inclined surface of the inclined member and the nip forming unit, on the surface of the feeding unit A sheet material feeding device comprising a conductive material that is in close contact with or in contact with and grounded. An image forming apparatus comprising: the sheet material feeding device according to claim 2; and an image forming unit that forms an image on the sheet material fed from the sheet material feeding device.

Images