JP2000007175A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device equipped with a sheet feed device which can perform the sheet feeding operation certainly. SOLUTION: A first conductive member 8 contacting with the reverse surface of a sheet of paper S1 is installed between a sheet feeding means 10 and separating means 7 while a second conductive member 12 is installed upstream of the feeding means 10 about the sheet transporting direction, and a bias voltage is impressed on these conductive members 8 and 12 so as to remove the static electricity generated on the sheet. The surfaces of the conductive members 8 and 12 are rubbed by electricity removing members 14 and 16 to remove the static electricity so that the paper dust attached to the surfaces of the conductive members 8 and 12 is taken away. A bias voltage is impressed on a conductive pressing member 9 which abuts the sheet S1 to the first member 8, and the static electricity is removed from the sheet S1 and the paper dust is prevented from attaching to the transporting means 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus provided with a paper feeding device, and more particularly to an image forming device for preventing paper dust from adhering to paper feeding means provided in the paper feeding device.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as an LBP or a copying machine, a sheet loaded on a sheet stacking unit is fed by a feeding unit by a substantially constant amount, and the fed sheet is separated by a separating / conveying unit. Some include a sheet feeding device configured to separate and convey each sheet.

FIG. 7 is a diagram showing a schematic configuration of a separating and conveying means in such a conventional sheet feeding apparatus. In FIG. 7, reference numeral 101 denotes a substantially constant amount of the uppermost sheet S1 stacked on the sheet stacking means. A feeding roller which is a feeding means for feeding,
102 is a feed roller, and 103 is a retard roller. Here, the retard roller 103 is rotatably supported on a fixed shaft 106 by a roller holder 104 that is rotatably supported by a rotating shaft 10.
9 and is in pressure contact with the feed roller 102 at a predetermined pressure by the force of a spring 105.

Here, at the time of separation and conveyance, the feed roller 1
02 rotates in the sheet conveying direction indicated by the arrow a in the figure, while the retard roller 103 originally rotates in the direction of the arrow b in the figure. It is configured to follow in the direction of arrow c.

[0005] This torque is applied to the feed roller 10.
The frictional force between the sheets when a plurality of sheets S has entered the nip portion between the sheet 2 and the retard roller 103 is larger than
Retard roller 10 when one sheet S has entered
3 is set to be smaller than the frictional force between the sheet S and the sheet S.
In order to take such a configuration, it is common to provide a torque limiter (not shown) on the shaft 109 of the retard roller 103 which rotates in a direction in which the sheet is returned by a drive transmission means (not shown).

Therefore, when only the uppermost sheet S1 is fed by the feeding roller 101, the frictional force between the retard roller 103 and the sheet S1 is larger than the torque limiter value, so that the frictional force between the retard roller 103 and the sheet S1 is increased. Is rotated in the direction of arrow c. Also, sheet S
When a plurality of sheets have entered, since the set value of the torque limiter is larger than the frictional force between the sheets, the retard roller 103 rotates in the direction of arrow b to prevent the plurality of sheets from entering.

As a result, only the uppermost sheet S1 is fed by the feed roller 102, and the sheets can be reliably fed one by one into the image forming apparatus main body.

[0008]

However, in such a conventional image forming apparatus, when the number of fed sheets increases,
A frictional potential is generated on the sheets due to frictional charging between the sheets, and when a frictional potential is generated on the sheets in this manner, the paper powder attached to the front and back surfaces of the sheets is also charged.

Here, when the paper dust is charged in this way, the paper dust adheres to the surfaces of the feed roller 101, the feed roller 102 and the retard roller 103, whereby the friction coefficient of the roller surface decreases. .

When the friction coefficient of each roller surface is reduced as described above, The feed roller 101 comes into contact with the uppermost sheet S1, and feeds the sheet S1 to the feed roller 102 and the retard roller 10
3, the feeding roller 101 slips. 2. Even if the sheet S1 is conveyed to the nip of the feed roller 102 and the retard roller 103, the feed roller 102
Slips. 3. Even if the retard roller 103 is in contact with the feed roller 102, the sheet S1 does not rotate with the feed roller 102, and moves to return the sheet S1 to the sheet stacking unit. Thus, when the sheet S1 hits the retard roller 103, the sheet S1 does not enter the nip between the rollers.

However, there has been a problem that the sheet feeding becomes defective.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide an image forming apparatus provided with a sheet feeding device capable of reliably performing a sheet feeding operation. It is assumed that.

[0013]

According to the present invention, there is provided an image forming apparatus provided with a sheet feeding device for feeding a sheet stacked on a sheet stacking means. The paper dust adhered by the method is removed.

According to another aspect of the present invention, there is provided an image forming apparatus provided with a sheet feeding device having a sheet feeding device for feeding a sheet stacked on a sheet stacking device inside a main body. A conductive member that is provided on the side and is in contact with the sheet and is electrically connected to the main body, or to which a bias voltage for removing static electricity generated in the sheet while being electrically insulated from the main body is applied. A removing member that rubs the surface of the conductive member and removes paper dust attached to the surface of the conductive member with the removal of the static electricity;
It is characterized by having.

According to the present invention, there is further provided a feeding means for feeding a sheet stacked on a sheet stacking means into a main body, a conveying means rotating in a sheet conveying direction, and a separating means rotating in a direction opposite to the sheet conveying direction. And a separating and conveying unit for separating the sheets fed by the feeding unit one by one and conveying the separated sheets to an image forming unit. Between the sheet and the separating means, which is in contact with the back surface of the sheet fed by the feeding means and is electrically connected to the main body, or is electrically insulated from the main body to the sheet. A conductive member to which a bias voltage for removing generated static electricity is applied, and a removing member for rubbing the surface of the conductive member and removing paper dust attached to the surface of the conductive member as the static electricity is removed. And the sheet A conductive pressing member that is pressed to make contact with the conductive member and is electrically connected to the main body, or to which the bias voltage is applied while being electrically insulated from the main body. It is characterized by the following.

According to the present invention, there is further provided a feeding means for feeding a sheet stacked on a sheet stacking means into a main body, a conveying means rotating in a sheet conveying direction, and a separating means rotating in a direction opposite to the sheet conveying direction. And a separating and conveying unit for separating the sheets fed by the feeding unit one by one and conveying the separated sheets to an image forming unit. Between the sheet and the separating means, which is in contact with the back surface of the sheet fed by the feeding means and is electrically connected to the main body, or is electrically insulated from the main body to the sheet. A first conductive member to which a bias voltage for removing the generated static electricity is applied, and a paper that rubs the surface of the first conductive member and adheres to the surface of the first conductive member with the removal of the static electricity First removing member for removing powder The bias voltage is provided upstream of the feeding unit in the sheet conveying direction so as to be in contact with the sheet and is electrically connected to the main body, or is electrically insulated from the main body. A second conductive member, a second removing member for rubbing the surface of the second conductive member to remove paper dust attached to the surface of the conductive member as the static electricity is removed, and A conductive pressing member that is pressed to make contact with the first conductive member and is electrically connected to the main body, or to which the bias voltage is applied while being electrically insulated from the main body. It is characterized by the following.

Further, as in the present invention, the sheet fed by the feeding means is provided between the feeding means for feeding the sheets stacked on the sheet loading means and the separating means constituting the separating / conveying means. A first conductive member in contact with the back surface is provided.
The conductive member is electrically connected to the main body, or a bias voltage is applied to the first conductive member in a state of being electrically insulated from the main body to remove static electricity generated on the sheet. Further, the surface of the first conductive member is rubbed with the first removing member to remove paper dust attached to the surface of the first conductive member as static electricity is removed.

A second conductive member is provided on the upstream side of the feeding means in the sheet conveying direction so as to contact the sheet.
The conductive member is electrically connected to the main body, or a bias voltage is applied to the second conductive member while being electrically insulated from the main body, thereby removing static electricity generated on the sheet. Further, the surface of the second conductive member is rubbed with the second removing member to remove paper dust attached to the surface of the second conductive member as static electricity is removed.

A conductive pressing member for pressing the sheet so as to contact the first conductive member with the main body;
Alternatively, a bias voltage is applied to the conductive pressing member in a state of being electrically insulated from the main body, thereby removing static electricity generated on the sheet and separating and transporting the paper powder with the removal of the static electricity. Do not adhere to the transport means that constitutes the means.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view of a laser beam printer which is an example of the image forming apparatus according to the first embodiment of the present invention.

In FIG. 1, reference numeral 200 denotes a laser beam printer main body (hereinafter, referred to as main body); 201, a paper feeding device provided in the main body 200; this paper feeding device 201 is a cassette 202 which is an example of sheet stacking means; A feeding roller (pickup roller) 10 serving as feeding means for feeding a substantially constant amount of recording paper (hereinafter, referred to as a sheet) stored in the cassette 202 by rotating and moving up and down; The feed roller 6 is provided downstream, and is provided with a feed roller 6 as a transporting unit for separating and transporting the sheets S fed by the feeding roller 10 one by one, and a retard roller 7 as a separating unit.

Downstream of the feed roller 6 and the retard roller 7, a transport roller 206 and a registration roller 207 for synchronously transporting the sheet S are provided.
Further, downstream of the registration roller 207, an image forming unit 209 having a photosensitive drum 208 for forming an image by a laser beam from the laser scanner unit 210 and a transfer roller 211 are provided. Further, a fixing device 212 and a sheet discharge conveyance roller 213 are provided downstream of the fixing device 212.

The sheet S synchronously conveyed by the registration rollers 207 is transferred to the image forming section 209 and the fixing device 2.
After the image is formed (printed) and the image is fixed by the sheet 12, the sheet is conveyed to a sheet discharge tray 216 by a sheet discharge conveyance roller 213. 4 is a resist sensor, 5
Is a conveyance guide plate.

On the other hand, in FIG.
Is a paper feed deck provided below the paper feeder and capable of supplying a large amount of paper. The sheet feeding device 1 includes a sheet stacking table 2 that is an example of a sheet stacking unit that is installed movably in the vertical direction.
, A feed roller 10, a feed roller 6, and a retard roller 7.

Here, the sheet loading table 2 is connected to a wire 51
The wire 51 is suspended by a take-up drum 53, which is a lifting / lowering means, or lifted up or down by winding. When the sheets are stacked on the sheet stacking table 9, the wire 51 is unwound by the winding drum 53 to lower the sheet stacking table 2 to a predetermined position, and then the sheet storage 15 is fed along the rail 54. This is done by pulling it out toward the deck.

On the other hand, the feed roller 10 holds the feed roller 6 at one end as shown in FIG. 2, and is held at the other end of a pickup arm 11 which moves up and down by a cam or the like (not shown). When the sheet S is separated and conveyed, the top sheet S1 on the sheet stacking table is brought into contact with the top sheet S1 in a rotating state for a certain period of time as the pickup arm 11 descends.
Is transported to the nip between the feed roller 6 and the retard roller 7.

In FIG. 1, reference numeral 20 denotes a sheet feeding deck 2.
The transport path forming unit 20 is provided at the upper end of the side surface of the transport unit 20. The transport path forming unit 20 includes a connecting transport path R between the main body 200 and the sheet feeding deck 220.

Next, the sheet feeding deck 2 constructed as described above
The separation and conveyance operation of the sheet 20 will be described.

To separate and transport the sheet S, first, FIG.
As shown in (1), the pickup arm 11 is lowered, and the rotating paper feed roller 10 is brought into contact with the uppermost sheet S1 on the sheet stacking table rising to a predetermined height for a certain period of time. Feed roller 6 for sheet S1
And feeds to the nip of the retard roller 7. After the uppermost sheet S1 has been fed to the nip of the feed roller 6 and the retard roller 7 in this manner, the sheet S
Is separated from the uppermost sheet S1 as shown in FIG.

On the other hand, the feed roller 6 rotates forward in the direction of feeding the sheet S1, and the retard roller 7 is pressed against the feed roller 6 with a predetermined pressure, and reversely rotates in the direction of feeding the sheet S1. ing.

When only one uppermost sheet S1 is fed, the conveying force due to the frictional force between the sheet S1 and the retard roller 7 exceeds the transmission torque of the torque limiter described above, so that the retard roller 7 The roller 6 rotates in the sheet feeding direction following the roller 6. In addition, 2
When more than one sheet is fed, the retard roller 7 rotates in the reverse direction, and only the top sheet S1 that is in contact with the feed roller 6 is fed by the feed roller 6, and the other sheets S2 are fed by the retard roller 7. Pushed back by.

As a result, only the uppermost sheet S 1 is separated and conveyed by the feed roller 6 and the retard roller 7, and is conveyed to the main body 200 by the conveying rollers 21 arranged on the connecting conveying path R of the conveying path forming unit 20.

By the way, between the feed roller 10 and the feed roller 6, as shown in FIG. 2, a first conductive member which is a first conductive member which is in contact with the back surface of the sheet S1 conveyed by the feed roller 10. Sex rollers are provided.

Here, the first conductive roller 8 is electrically insulated from the sheet feeding deck 220 and has a bias voltage for canceling a triboelectric charge on the sheet surface generated when the sheets rub against each other. It is applied by a bias power supply 17. When the first conductive roller 8 to which such a bias voltage is applied comes into contact with the sheet S1, it is possible to remove frictional charges (static electricity) generated on the sheet S1.

When the bias voltage is applied to the first conductive roller 8 in this manner, the paper powder adhered to the back surface of the sheet S1 adheres to the first conductive roller 8 due to the bias voltage. In order to prevent the paper dust thus adhered from adhering to the sheet S1 again, there is a first removing member which rubs the surface of the first conductive roller 8 below the sheet passing surface as shown in FIG. A first cleaning blade 16 is provided.

Here, since the retard roller 6 and the feed roller 7 continue to convey the sheet S1 without being separated, the distance in contact with the sheet S1 becomes longer than that of the sheet feeding roller 10, so that the paper dust is easily adsorbed. The retard roller side where the two rub against each other is particularly easily charged.

However, after the paper dust adhering to the sheet S1 is attached to the first conductive roller 8 and then removed by the first cleaning blade 16, the paper dust adheres to the retard roller 6. Can be prevented. As a result, it is possible to prevent a decrease in the friction coefficient of the roller surface, and it is possible to reliably perform the sheet separating and conveying operation.

In the same figure, reference numeral 9 denotes a conductive sheet which is a conductive pressing member for pressing the sheet S1 so as to contact the first conductive roller 8. In the present embodiment, a bias voltage described later is also applied to the conductive sheet 9 by a bias power supply 18.

On the other hand, reference numeral 12 denotes a second conductive member provided upstream of the feeding roller 10 in the sheet conveying direction.
The second conductive roller 12 is held in contact with the sheet S1 by an arm 13 rotatably held by a pickup arm 11 via a rotation shaft 10a of a feeding roller 10. ing.

The second conductive roller 12 is electrically insulated from the sheet feeding deck 220 and is connected to a bias power supply 18 having characteristics reverse to the frictional charge on the sheet surface generated when the sheets rub against each other. ing. By the bias voltage applied by the bias power supply 18 having the reverse characteristic, the paper powder is adsorbed on the second conductive roller 12 and at the same time, the triboelectric charge (static electricity) generated on the sheet S1 can be removed. .

In order to prevent the paper dust adsorbed by the second conductive roller 12 from adhering to the sheet S1 again, the arm 13 is provided with a second removing member rubbing the surface of the second conductive roller 12. A certain second cleaning blade 14 is attached. Then, the second cleaning blade 14
As a result, the paper dust adsorbed on the second conductive roller 12 is scraped off, and the stripped paper powder P accumulates between the second conductive roller 12 and the second cleaning blade 14. .

Here, the paper dust adhering to the sheet S 1 is attached to the second conductive roller 12 and then removed by the second cleaning blade 14,
Paper dust can be prevented from adhering to the feeding roller 10. As a result, a reduction in the friction coefficient of the roller surface can be prevented, and the feeding roller 10 can reliably perform the sheet feeding operation.

Next, the paper dust removing operation of the paper feeder configured as described above will be described.

As described above, when the sheet S1 is separated and conveyed, the rotating sheet supply roller 10 is moved to the uppermost sheet S.
1, the top sheet S1 is fed to the nip between the feed roller 6 and the retard roller 7 while being in contact with
At this time, as shown in FIG. 2, the second conductive roller 12 is also in contact with the uppermost sheet S1.

Then, the second conductive roller 12 is
As shown in (2), even after the paper feed roller 10 is separated from the uppermost sheet S1, when the uppermost sheet S1 is being conveyed while being rubbed with other sheets on the sheet stacking table 2, the sheet is always in contact. Thereby, the triboelectric charge generated on the sheet S1 is removed by the bias voltage applied to the second conductive roller 12, and the paper dust attached to the sheet S1 is adsorbed on the second conductive roller 12.

The paper dust adsorbed on the second conductive roller 12 is scraped off by the second cleaning blade 14, and the second conductive roller 12 and the cleaning blade 1 are removed.
4 and does not adhere to the sheet S1 again.

On the other hand, the sheet S 1 fed by the feed roller 10 enters the nip between the feed roller 6 and the retard roller 7, but before this, the sheet S 1 passes while contacting the upper surface of the first conductive roller 8. . And at this time,
The triboelectric charge generated on the sheet S1 is removed by the bias voltage applied to the first conductive roller 8, and the paper dust attached to the sheet S1 is attracted to the first conductive roller 8 by an electric force. .

The paper dust adsorbed by the first conductive roller 8 is scraped off by the first cleaning blade 16 and accumulates in the paper dust receiver 16a attached to the first cleaning blade 16, and adheres again to the sheet S1. I will not do it.

Incidentally, the sheet S 1 is lightly pressed against the first conductive roller 8 by the conductive sheet 9 so as to surely contact the first conductive roller 8. , And is connected to a bias power source 18 having characteristics opposite to the frictional charges on the sheet surface generated when the sheets rub against each other.

Therefore, even if the sheet surface is frictionally charged due to the rubbing between the sheet S1 and the conductive sheet 9, the frictional charge is removed by the bias voltage. Further, since the paper dust adhering to the sheet S1 is attracted to the conductive sheet 9 by an electric force, the paper dust does not adhere even if the sheet S1 comes into contact with the feed roller 6.

As described above, the bias voltage is applied to the conductive sheet 9, the first conductive roller 8, and the second conductive roller 12 to remove the static electricity generated on the sheet S1, and to remove the first sheet.
By removing the paper dust attached to the surfaces of the conductive roller 8 and the second conductive roller 12, the paper dust can be prevented from attaching to the surfaces of the feed roller 10, the feed roller 6, and the retard roller 7. . As a result, a reduction in the coefficient of friction of the roller surface can be prevented, and the sheet feeding operation can be reliably performed.

Next, a second embodiment of the present invention will be described.

FIG. 4 is a sectional view of a laser beam printer as an example of the image forming apparatus according to the present embodiment, and FIG. 5 is an enlarged view of a main part of a paper feeding deck of the laser beam printer. 4 and 5, the same reference numerals as those in FIGS. 1 and 3 indicate the same or corresponding parts.

In FIGS. 4 and 5, reference numeral 1A denotes a sheet feeding device of a sheet feeding deck 220. The sheet feeding device 1A conveys the sheet between the feed roller 10 and the feed roller 6 by the feed roller 10. A first conductive roller 8A is provided in contact with the back surface of the sheet S1.

Here, the first conductive roller 8A is electrically connected to the sheet feeding deck 220. When the first conductive roller 8A is electrically connected to the sheet feeding deck 220 as described above, When the first conductive roller 8 </ b> A contacts the sheet S <b> 1, triboelectric charges on the sheet surface generated when the sheets rub against each other flow to the sheet feeding deck 220.

Reference numeral 12A denotes a second conductive roller provided on the upstream side of the feeding roller 10 in the sheet conveying direction.
The second conductive roller 12A is always in contact with the uppermost sheet S when the uppermost sheet S is conveyed while being rubbed with other sheets on the sheet stacking table 2.

Here, the second conductive roller 12A is electrically connected to the sheet feeding deck 220. Thus, the second conductive roller 12A is electrically connected to the sheet feeding deck 220, so that the sheet is The triboelectric charges on the sheet surface generated when the members rub against each other flow to the sheet feeding deck 220 through the second conductive rollers 12.

Further, 9A is a conductive sheet for pressing the sheet S1 against the first conductive roller 8A. This conductive sheet 9A is also electrically connected to the sheet feeding deck 220. Sheet 9A is the paper feed deck 2
By conducting to the sheet 20, the triboelectric charges on the sheet surface generated when the sheet S1 and the conductive sheet 9A are rubbed flow through the sheet feeding deck 220 through the conductive sheet 9A.

Next, the paper dust removing operation of the paper feeder configured as described above will be described.

As described above, when the sheet S is separated and conveyed, the rotating sheet feed roller 10 is moved to the uppermost sheet S1.
Is fed to the nip between the feed roller 6 and the retard roller 7 for a certain period of time. At this time, as shown in FIG. 5, the second conductive roller 12A is also in contact with the uppermost sheet S1.

The second conductive roller 12A rubs the uppermost sheet S1 against other sheets of the sheet stacking table 2 even after the sheet feeding roller 10 is separated from the uppermost sheet S1 as shown in FIG. When the sheet is conveyed, the sheet is always in contact with the sheet S1. Thereby, the triboelectric charge generated on the sheet S1 flows to the sheet feeding deck 220 through the second conductive roller 12A, and the paper dust attached to the sheet S1 is adsorbed on the second conductive roller 12.

The paper dust P adsorbed by the second conductive roller 12 is scraped off by the second cleaning blade 14, accumulates between the second conductive roller 12 and the second cleaning blade 14, and becomes a sheet again. It does not adhere to S1.

On the other hand, the sheet S1 fed by the feed roller 10 passes through the nip between the feed roller 6 and the retard roller 7 while being in contact with the upper surface of the first conductive roller 8A. At this time, the sheet S1 is lightly pressed against the first conductive roller 8A by the conductive sheet 9 so as to surely contact the first conductive roller 8A.

Thus, the triboelectric charges of the sheets generated when the sheets rub against each other flow from the first conductive roller 8A to the sheet feeding deck 220. At this time, the first conductive rollers 8
The paper dust is adsorbed to A, and the paper dust is scraped off by the first cleaning blade 16 and accumulates in the paper dust receiver 16a of the first cleaning blade 16.

Further, the triboelectric charge on the sheet surface generated when the sheet S1 and the conductive sheet 9 are rubbed flows to the sheet feeding deck 220 through the conductive sheet surface. Therefore, even if the front and back surfaces of the sheet S1 come into contact with the feed roller 6 and the retard roller 7, paper powder does not adhere.

In this way, the conductive sheet 9, the first conductive roller 8, the second conductive roller 12, and the sheet feeding deck 220 are electrically connected to remove the static electricity generated on the sheet S1, and the first conductive roller 9, By removing the paper dust attached to the surfaces of the rollers 8 and the second conductive rollers 12, it is possible to prevent the paper dust from attaching to the surfaces of the feed roller 10, the feed roller 6, and the retard roller 7. As a result, a reduction in the coefficient of friction of the roller surface can be prevented, and the sheet feeding operation can be reliably performed.

In the above description, although the configuration of the first and second conductive rollers 8, 8A, 12, 12A is not particularly described, these first and second conductive rollers 8, 8 are not described.
A, 12, and 12A may be driven rollers that are brought in contact with the sheet S1 or drive rollers that rotate by a drive system (not shown). Further, the second conductive roller 1
2, 2A are separated from the sheet surface by operating means (not shown) at the time of attaching and detaching the sheet storage, so that they do not hinder the movement of the sheet storage 15.

[0069]

As described above, according to the present invention, the static electricity generated on the sheet by the first and second conductive members is removed and the surfaces of the first and second conductive members are removed with the removal of the static electricity. By removing the paper dust attached to the sheet, it is possible to prevent the paper dust from attaching to the feeding means and the separation / conveyance means. This makes it possible to prevent a decrease in the coefficient of friction of the surface of the feeding unit or the separation / conveying unit, and to reliably perform the sheet feeding operation.

[Brief description of the drawings]

FIG. 1 is a sectional view of a laser beam printer as an example of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of a sheet feeding device of a sheet feeding deck of the laser beam printer.

FIG. 3 is a diagram illustrating a sheet separating and conveying operation of a sheet feeding device of the sheet feeding deck.

FIG. 4 is a sectional view of a laser beam printer as an example of an image forming apparatus according to a second embodiment of the present invention.

FIG. 5 is an enlarged view of a main part of a paper feeding deck of the laser beam printer.

FIG. 6 is a diagram illustrating a sheet separating and conveying operation of a sheet feeding device of the sheet feeding deck.

FIG. 7 is an enlarged view of a main part showing a schematic configuration of a sheet feeding device of a conventional image forming apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sheet feeder 2 sheet stacking table 6 feed roller 7 retard roller 8, 8A first conductive roller 9 conductive sheet 10 feed roller 12, 12A second conductive roller 14 first cleaning blade 16 second cleaning blade A 17 , 18 Bias power supply 200 Main body 220 Paper feed deck S sheet

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuhiro Uchida 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Yuzo Isoda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside (72) Inventor Takashi Kuwata 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Makoto Izumi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. ( 72) Inventor Hiroaki Namiki 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2C061 BB19 CM03 CM13 CP03 2H072 BA03 BA13 3F101 AB03 AB09 AB14 AB16 AB19 LA01 LB01 3F343 FA02 FB01 FC17 FC20 FC24 GA01 GB01 GC01 GD01 JA01 KB04 KB05 KB11

Claims (4)

[Claims] 1. An image forming apparatus comprising a sheet feeding device for feeding a sheet stacked on a sheet stacking unit, wherein static electricity generated on the sheet is removed to remove paper dust adhered to the sheet by the static electricity. An image forming apparatus comprising: 2. An image forming apparatus comprising a sheet feeding device having a sheet feeding means for feeding a sheet stacked on a sheet stacking means inside a main body, wherein the image forming apparatus is provided upstream of the sheet feeding means in a sheet conveying direction. A conductive member that is in contact with the sheet and is electrically connected to the main body, or to which a bias voltage for removing static electricity generated in the sheet in a state of being electrically insulated from the main body is applied; An image forming apparatus comprising: a removing member that rubs the surface of a conductive member to remove paper dust attached to the surface of the conductive member as the static electricity is removed. 3. A sheet feeding device for feeding sheets stacked on a sheet stacking device, a conveying device rotating in a sheet conveying direction, and a separating device rotating in a direction opposite to the sheet conveying direction. An image forming apparatus provided with a sheet feeding device having a sheet conveying device for separating the sheets fed by the feeding unit one by one and conveying the separated sheets to an image forming unit; Provided between the sheet feeding means and the sheet feeding means, the sheet being in contact with the back surface of the sheet and being electrically connected to the main body, or generated in the sheet while being electrically insulated from the main body. A conductive member to which a bias voltage for removing the conductive member is applied; and a removing member for rubbing the surface of the conductive member to remove paper dust attached to the surface of the conductive member as the static electricity is removed. Sheet the conductive part And a conductive pressing member to which the bias voltage is applied in a state where the bias voltage is applied while being pressed to make contact with the material and electrically connected to the main body or electrically insulated from the main body. Image forming apparatus. 4. A sheet feeding device for feeding a sheet stacked on a sheet stacking unit, a conveying unit rotating in a sheet conveying direction, and a separating unit rotating in a direction opposite to the sheet conveying direction. An image forming apparatus provided with a sheet feeding device having a sheet conveying device for separating the sheets fed by the feeding unit one by one and conveying the separated sheets to an image forming unit; Provided between the sheet feeding means and the sheet feeding means, the sheet being in contact with the back surface of the sheet and being electrically connected to the main body, or generated in the sheet while being electrically insulated from the main body. A first conductive member to which a bias voltage for removing the first conductive member is applied; and rubbing the surface of the first conductive member to remove paper dust adhering to the surface of the first conductive member as the static electricity is removed. A first removing member, A second portion, which is provided on the upstream side in the sheet conveying direction of the feeding means so as to be in contact with the main body and is electrically connected to the main body, or in which the bias voltage is applied while being electrically insulated from the main body. A conductive member; a second removing member for rubbing the surface of the second conductive member to remove paper dust attached to the surface of the conductive member as the static electricity is removed; and A conductive pressing member that is pressed to make contact with a conductive member and is electrically connected to the main body, or to which the bias voltage is applied while being electrically insulated from the main body. Characteristic image forming apparatus.