JP2021062938A - Sheet conveyance device and image forming apparatus - Google Patents

Abstract

To provide a sheet conveyance device capable of preventing a foreign substance retrieved from a pair of conveyance rollers that can be pressure-welded to and separated from each other from entering a conveyance path when the pair of conveyance rollers are separated from each other, and an image forming apparatus.SOLUTION: In a registration roller unit 100 capable of pressure-welding and separating a driven roller 101 to and from a driving roller 102, a foreign substance removal mechanism makes a long side 302a of a thin film 302 contact an outer peripheral surface of the driven roller 101 to scrape a foreign substance such as paper powder and wipe the remaining foreign substance with a foam sponge 301. A partition member 201 is fixed to a conveyance guide 103 that guides a recording sheet to a conveyance nip 501, and a distal end 201a of the partition member 201 contacts the outer peripheral surface of the driven roller 101. The partition member 201 separates the foreign substance removal mechanism and a conveyance path 104, to prevent a foreign substance that drops from the foreign substance removal mechanism from entering the conveyance path 104.SELECTED DRAWING: Figure 5

Description

The present disclosure relates to a sheet transport device and an image forming device, and more particularly to a technique for preventing image deterioration due to paper dust generated from paper.

In the electrophotographic image forming apparatus, for example, as a timing roller for skew correction, paper is conveyed by using a transfer roller pair and used for image formation. After the paper dust generated from the paper during transportation adheres to the surface of the transport roller, it is shaken off by the separating operation of the transport roller pair, and when the paper is transported to the downstream side in the paper transport direction, the toner image is transferred to the paper. Image deterioration occurs in the transfer section. Further, in the tandem image forming apparatus, when the paper dust adhering to the intermediate transfer belt is clogged between the intermediate transfer belt and the cleaning blade for cleaning the residual toner on the intermediate transfer belt, the residual toner slips through the cleaning blade. Since it becomes easy, image deterioration may occur.

To solve such a problem, for example, a technique for removing paper dust adhering to the surface of a transport roller with a film-shaped scraper is known.

Further, in recent years, as a result of being able to use various types of paper in an image forming apparatus, the shape of paper dust generated from the paper has also diversified into fine powder and fibrous forms. Various types of scrapers have been devised accordingly. For example, an effervescent sponge can wipe off fine paper dust that cannot be scraped off with a film-like scraper.

Japanese Unexamined Patent Publication No. 2006-264838 Japanese Unexamined Patent Publication No. 2004-161473 Japanese Unexamined Patent Publication No. 2004-161409

Of the foamed sponges, the single-foamed foamed sponge has independent bubbles, so that air cannot flow in and out of each bubble. Therefore, in order to elastically deform the foam sponge of a single bubble, the air in the bubble must be compressed, so that the elastic modulus is high. Due to these characteristics, when the foamed sponge is pressed against the transport roller, the surface of the transport roller is likely to be scratched or the torque is easily increased due to a high load.

On the other hand, in the foam sponge of continuous foam, the bubbles are communicated with each other, and when elastically deformed, the air in the bubbles is discharged to the outside of the sponge via this communication path. Therefore, since the continuous foam foam sponge has a lower elastic modulus than the single foam foam sponge, the above-mentioned problems can be avoided.

However, the communication path of air bubbles not only allows air to flow, but also allows paper dust to pass through if it is fine, so that the paper dust wiped from the transport roller cannot always be retained and diffuses. It ends up.

In particular, when the foam sponge is pressed against a transport roller pair that can be pressure-welded and separated to wipe off the paper dust, if the transport roller pair is separated, the paper dust diffused from the foam sponge enters the paper transport path. , May cause image deterioration as described above.

The present disclosure has been made in view of the above-mentioned problems, and prevents foreign matter collected from a pair of transport rollers that can be pressure-welded and separated from entering the transport path when the pair of transport rollers is separated. It is an object of the present invention to provide a sheet transfer device and an image forming device that can be prevented.

In order to achieve the above object, the sheet transfer device according to one embodiment of the present disclosure is capable of pressure contact separation, and at the time of pressure contact, a transfer roller pair that conveys a sheet along a transfer path and a transfer roller pair from the pressure contact position. A foreign matter removing mechanism for removing foreign matter adhering to the outer peripheral surface of the movable roller displaced to the separated position, a moving means for moving the foreign matter removing mechanism together with the movable roller to the separated position side, and the foreign matter removing mechanism for the transport path. The partition member is provided with a partition member for partitioning between the inside of the path and the outside of the path so as to be located outside the path, and the partition member is immovable regardless of the pressure contact separation state of the transport roller pair.

In this case, when the partition member is pressed against the transport roller pair, the partition member extends from the removal action position of the foreign matter removing mechanism to the transport nip of the transport roller pair along the rotation direction on the outer peripheral surface of the movable roller. Even if it comes into contact with the outer peripheral surface portion between the two to remove foreign matter adhering to the outer peripheral surface and the contact position is set and adjusted to a position close to the transport nip within a range that does not interfere with the transport of the sheet. Good.

Further, the partition member may abut on the outer peripheral surface in a posture from the upstream side to the downstream side of the contact position with the movable roller in the rotation direction of the movable roller.

Further, the moving means swings the movable roller between the pressure contact position and the separated position with the upstream side of the transport roller pair in the sheet transport direction as the swing center, and the foreign matter together with the movable roller. The removal mechanism may be rocked.

Further, the foreign matter removing mechanism may include a plurality of foreign matter removing members made of different materials from each other, and the foreign matter may be removed by bringing the plurality of foreign matter removing members into contact with the outer peripheral surface of the movable roller.

Further, the plurality of foreign matter removing members are a thin-walled film and a continuous foam foam sponge, and the tip of the thin-walled film is brought into contact with the outer peripheral surface of the movable roller to scrape off the foreign matter, and the foamed sponge is used. Foreign matter may be wiped off by pressure contacting the outer peripheral surface.

Further, a plate-shaped rush guide for guiding the sheet to the transport nip of the transport roller pair along the transport path is provided, and the partition member is fixed to a surface of the rush guide opposite to the transport path. You may.

Further, the image forming apparatus according to one aspect of the present disclosure is provided with the sheet conveying device according to one aspect of the present disclosure, and the sheet conveying device is used to convey a sheet to be used for image forming.

In this case, the resist roller is provided with a transfer unit for transferring an image to the sheet, and the transfer roller pair is arranged on the upstream side of the transfer unit in the sheet transfer direction to adjust the transfer timing of the sheet. May be good.

In this way, since the inside and outside of the transport path are partitioned by the partition member so that the foreign matter removing mechanism is outside the transport path, the foreign matter removed by the foreign matter removal mechanism enters the sheet transport path from the outer peripheral surface of the movable roller. It is possible to prevent deterioration of image quality.

It is a figure which shows the main structure of the image forming apparatus 1 which concerns on embodiment of this disclosure. In the external perspective view of the resist roller unit 100, (a) shows a state in which the driven roller 101 is pressed against the drive roller 102, (b) shows a state in which the driven roller 101 is separated from the drive roller 102, and (c). ) Is an enlarged view of the rectangular region 221 in (b). (A) is an external perspective view of the driven roller 101 and the foreign matter removing mechanism 300, and (b) is an exploded perspective view of the driven roller 101 and the foreign matter removing mechanism 300. It is a figure explaining the contact angle of the thin film 302 and the partition member 201 with respect to the outer peripheral surface of a driven roller 101. It is sectional drawing of the resist roller unit 100, the partition member 201 and the foreign matter removal mechanism 300, (a) shows the state which pressed the driven roller 101 with the drive roller 102, (b) is the state which pressed the driven roller 101 with the drive roller 102. Indicates a state separated from. It is a figure which shows the main structure of the image forming apparatus 1 which concerns on the modification of this disclosure.

Hereinafter, embodiments of the sheet transfer device and the image forming device according to the present disclosure will be described with reference to the drawings.

[1] Configuration of Image Forming Device First, the configuration of the image forming apparatus according to the present embodiment will be described.

As shown in FIG. 1, the image forming apparatus 1 according to the present embodiment is a so-called tandem color multifunction device (MFP: Multi-Function Peripheral), and is a control unit 111 and an image forming unit 120Y, 120M, 120C. And 120K, the paper feed trays 131a and 131b, the image reading unit 141, the operation panel 151 and the like are provided.

When reading a document by the sheet-through method, the image reading unit 141 reads the documents sent out one by one from the document tray 143 using an automatic document feeder (ADF: Automatic Document Feeder) 142, and reads the image data. Generate. The generated image data is stored in the control unit 111.

When the user accepts an image forming job by instructing using the operation panel 151, or receives an image forming job from another device via a communication network 110 (not shown), the control unit 111 receives the image forming device 1. Is controlled to execute an image forming process using the image data generated by the image reading unit 141 and the image data received from another device.

The image-forming units 120Y, 120M, 120C and 120K form toner images of each color of yellow (Y), magenta (M), cyan (C) and black (K), respectively. Since the image forming unit 120Y, 120M, 120C and 120K have a common configuration, the image forming unit 120Y will be described as an example. The image forming unit 120Y includes a photoconductor drum 121Y, a charging device 122Y, an exposure device 123Y, and a developing unit. It includes a device 124Y, a primary transfer roller 125Y and a cleaning device 126Y.

The image forming unit 120Y uniformly charges the outer peripheral surface of the photoconductor drum 121Y by using the charging device 122Y while rotating the photoconductor drum 121Y in the direction of arrow A. The exposure apparatus 123Y forms an electrostatic latent image by irradiating the outer peripheral surface of the photoconductor drum 121Y with a laser beam modulated according to the image data. The developing apparatus 124Y develops an electrostatic latent image and forms a toner image by supplying Y-colored toner to the outer peripheral surface of the photoconductor drum 121Y.

The primary transfer roller 125Y electrostatically transfers the toner image supported on the outer peripheral surface of the photoconductor drum 121Y onto the outer peripheral surface of the intermediate transfer belt 112 by applying the primary transfer bias (primary transfer). .. After the primary transfer, the cleaning device 126Y removes static electricity by exposing the outer peripheral surface of the photoconductor drum 121Y, and then scrapes off the toner remaining on the outer peripheral surface with a cleaning blade.

The intermediate transfer belt 112 is hung around a roller such as the primary transfer roller 125Y, and while traveling in the direction of arrow B, the intermediate transfer belt 112 is primarily transferred so that the toner images of each color of YMCK overlap each other. As a result, a color toner image is formed. The color toner image is conveyed to the secondary transfer position by the intermediate transfer belt 112.

In parallel with the toner image forming process as described above, the recording sheet S of the paper type specified in the image forming job is fed. For example, the recording sheets housed in the paper feed tray 131a are sent out one by one by the paper feed mechanism 132a, and the recording sheets housed in the paper feed tray 131b are sent out one by one by the paper feed mechanism 132b. Further, FIG. 1 shows a state in which the manual feed tray 131c is closed, and when the manual feed tray 131c is opened in the direction of the arrow C, the recording sheet S can be placed. The recording sheets S on the bypass tray 131c are also sent out one by one by the paper feeding mechanism 132c.

A resist roller unit 100 is arranged on the transport path of the recording sheet S from the paper feed trays 131a and 131b and the manual feed tray 131c to the secondary transfer position. The resist roller unit 100 includes a driven roller 101 and a driving roller 102. The drive roller 102 is arranged below the transport path 104 of the recording sheet S in the vertical direction, and the rotation axis is fixed. On the other hand, the driven roller 101 is arranged above the transport path 104 of the recording sheet S in the vertical direction. The driven roller 101 is a movable roller that swings around a swing shaft (not shown), and can be pressure-contacted and separated from the drive roller 102.

The resist roller unit 100 adjusts the timing of transporting the recording sheet S to the secondary transfer position. Specifically, with the drive roller 102 stopped, the recording sheet S is conveyed along the transfer path 104 using the transfer guide 103, and the driven roller 101 and the drive roller 102 are pressure-welded to each other. The head of the recording sheet S is abutted against 5 (a).). In this state, if the recording sheet S is further conveyed to form a loop, the skew of the recording sheet S is corrected. After that, the drive roller 102 starts rotating in accordance with the secondary transfer timing, and conveys the recording sheet S to the secondary transfer position.

At the secondary transfer position, the secondary transfer roller 113 is pressed against the intermediate transfer belt 112, and is supported on the outer peripheral surface of the intermediate transfer belt 112 by applying the secondary transfer bias to the secondary transfer roller 113. The color toner image is electrostatically transferred to the recording sheet S (secondary transfer). The toner remaining on the outer peripheral surface of the intermediate transfer belt 112 after the secondary transfer is conveyed to the cleaning device 117 by the intermediate transfer belt 112 traveling around. The cleaning device 117 uses a cleaning roller or a cleaning blade to scrape the residual toner from the outer peripheral surface of the intermediate transfer belt 112 and discard it.

The recording sheet S to which the color toner image is secondarily transferred is heat-fixed with the color toner image by the fixing device 114, and then discharged onto the paper ejection tray 116 by the paper ejection roller pair 115.

[2] Configuration of Resist Roller Unit 100 The configuration of the resist roller unit 100 will be described in more detail.

(2-1) Resist Roller Unit 100
As shown in FIG. 2A, the resist roller unit 100 is covered with the cover 211 in a state where the driven roller 101 and the driving roller 102 are in pressure contact with each other, and the driven roller 101 and the like cannot be seen from the outside.

On the other hand, as shown in FIG. 2B, when the driven roller 101 and the driving roller 102 are separated from each other, the cover 211 also swings together with the driven roller 101 so that the driven roller 101 can be seen from the outside. Become. When the control unit 111 controls a drive motor (not shown), the driven roller 101 reciprocates around a swing shaft 212, which will be described later, swings together with the cover 211, and is pressure-contacted and separated from the drive roller 102.

Further, in a state where the driven roller 101 and the driving roller 102 are separated from each other, as shown in FIG. 2C, in addition to the driven roller 101, foreign matter such as paper dust removed from the driven roller 101 is recorded on the recording sheet S. The partition member 201 that prevents the paper from entering the transport path of the paper can be seen from the outside.

(2-2) Foreign matter removal mechanism 300
As shown in FIG. 3A, the resist roller unit 100 includes a foreign matter removing mechanism 300 for removing foreign matter such as paper dust adhering to the outer peripheral surface of the driven roller 101. The foreign matter removing mechanism 300 includes a foam sponge 301, a thin film 302, and a support member 303, and the foam sponge 301 and the thin film 302 are fixed and supported by the support member 303.

The foam sponge 301 is a continuous foam foam sponge member made of a material such as urethane, EPDM (Ethylene Propylene Diene Monomer), or PP (Poly Propylene). The thin film 302 is a thin film member made of a material such as SUS (Steel Use Stainless), PI (Poly Imide), PPS (Poly Phenylene Sulfide), PC (Poly Carbonate) sheet and PET (Poly Ethylene Terephthalate) sheet. ..

The thin film 302 is a film member that is long in the axial direction of the driven roller 101. One long side 302a of the thin film 302 has a free end and is in contact with the outer peripheral surface of the driven roller 101. The other long side 302b of the thin film 302 is fixed to the support member 303. The driven roller 101 and the support member 303 are fixed so as to have a constant positional relationship with each other regardless of the pressure contact separation state between the driven roller 101 and the driving roller 102, and shake together in the fixed state. Can move. As a result, the one long side 302a of the thin film 302 is pressed against the outer peripheral surface of the driven roller 101.

As shown in FIG. 4, the thin-walled film 302 has a driven roller 101 from the downstream side to the upstream side of the contact position between the thin-walled film 302 and the driven roller 101 in the rotation direction of the driven roller 101 rotating in the arrow D direction. Contact the outer peripheral surface of the. Therefore, the contact angle of the thin film 302 centered on the contact position with respect to the outer peripheral surface of the driven roller 101 is an acute angle.

Due to the space and component configuration in the image forming apparatus 1, it is more difficult to arrange the thin film 302 as it gets closer to the transport nip 501 (see FIG. 5A) from the upstream side in the rotation direction of the driven roller 101. Become. This is because, for example, the support member 303 that supports the thin film 302 and the transport guide 103 interfere with each other. For this reason, in the present embodiment, the thin film 302 comes into contact with the driven roller 101 at a position far from the transport nip 501.

In the process of removing paper dust from the outer peripheral surface of the driven roller 101 using the thin film 302, for example, when long fibrous paper dust is sandwiched between the thin film 302 and the outer peripheral surface of the driven roller 101, the thin film 302 A gap may be formed between the surface and the outer peripheral surface of the driven roller 101.

If there is such a gap, paper dust having a fine particle size may pass through the thin film 302 and enter the transport path of the recording sheet S, which may deteriorate the image quality. The foam sponge 301 is provided for the purpose of wiping off fine paper dust having a fine particle size that has slipped through the thin film 302. The foam sponge 301 has a long square pillar shape along the axial direction of the driven roller 101 in a free state without elastic deformation, and one side surface of the square pillar is fixed to the support member 303. ..

When the foam sponge 301 is pressed against the outer peripheral surface of the driven roller 101, the air inside is pushed out via the continuous foam and elastically compressed to form a shape along the outer peripheral surface. Since the continuous foam foam sponge 301 has a low elastic modulus as described above, it is difficult to wear the outer peripheral surface of the driven roller 101, and it is difficult to increase the torque of the driven roller 101.

A partition member 201 is arranged on the downstream side of the foamed sponge 301 in the rotation direction of the driven roller 101. The partition member 201 is made of materials such as SUS (Steel Use Stainless), PI (Poly Imide), PPS (Poly Phenylene Sulfide), PC (Poly Carbonate) sheet and PET (Poly Ethylene Terephthalate) sheet, similarly to the thin film 302. It is a thin-walled film member. The partition member 201 positions the foreign matter removing mechanism 300 outside the transport path 104 by partitioning the inside and outside of the transport path 104 of the recording sheet S.

(2-3) Partition member 201
The partition member 201 is a film member that is long in the axial direction of the driven roller 101. One long side 201a of the partition member 201 has a free end and is in contact with the outer peripheral surface of the driven roller 101. The contact position of the long side 201a is on the upstream side of the transfer nip 501 in the rotation direction of the driven roller 101, and is as close as possible to the transfer nip 501 within a range that does not prevent the recording sheet S from entering the transfer nip 501. The position is preferable.

It is desirable that the long side 201a of the partition member 201 is at least at a position closer to the transport nip 501 than the downstream end of the transport guide 103 in the transport direction of the recording sheet S. In this way, when the driven roller 101 is separated from the driving roller 102, it is possible to more reliably prevent paper dust from entering the transport path 104 from the foreign matter removing mechanism 300.

The other long side 201b of the partition member 201 is fixed to the transport guide 103. As a result, the one long side 302a of the thin film 302 is pressed against the outer peripheral surface of the driven roller 101.

Further, the transport guide 103 is fixed so as to be in a fixed position regardless of the pressure contact separation state between the driven roller 101 and the drive roller 102, and does not swing. Therefore, when the driven roller 101 is swung to be separated from the drive roller 102, even if the fine paper dust falls from the foreign matter removing mechanism 300 due to the continuous bubbles of the foam sponge 301 or the like. Since the partition member 201 partitions between the foreign matter removing mechanism 300 and the transport path of the recording sheet S, the amount of paper dust entering the transport path is suppressed to be small.

If a non-conductive resin film is used as the partition member 201 and also serves as a plunge guide for guiding the recording sheet S to the transport nip 501, the non-conductive resin film is charged by friction with the recording sheet S. , There is a risk of causing a paper jam by electrostatically adsorbing the recording sheet S.

To solve such a problem, if a conductive metal sheet metal guide plate is used as the transport guide 103 and the partition member 201 is fixed on the side opposite to the transport path 104 of the transport guide 103, the partition due to friction with the recording sheet S is formed. The charge on the member 201 can be reduced, and the partition plate 201 can be statically eliminated by the transport guide 103. Therefore, it is possible to prevent the occurrence of a paper jam due to the charging of the partition member 201.

(2-4) Swing mechanism As shown in FIGS. 2 (c) and 5 (a), the bearing member 214 of the driven roller 101 swings in the direction of arrow E about the swing shaft 212. It is fixed at 213. When the control unit 111 controls a drive motor (not shown) to swing the swing member 213 in the direction of arrow E in order to press-contact and separate the driven roller 101 and the drive roller 102, the bearing member 214 also swings in the direction of arrow E. Swing in the direction.

On the other hand, since the partition member 201 is fixed to the transport guide 103 and the transport guide 103 is fixed to a housing (not shown), the partition member 201 is held at a constant position regardless of the pressure contact separation state between the driven roller 101 and the drive roller 102. is there.

When the driven roller 101 is pressed against the drive roller 102, the tip 201a of the partition member 201 comes into contact with the outer peripheral surface of the driven roller 101. This prevents the paper dust that has fallen from the foreign matter removing mechanism 300 from entering the transport path 104.

Further, as shown in FIG. 5B, when the driven roller 101 is swung in the direction of arrow E and separated from the driving roller 102, the driven roller 101 is also separated from the partition member 201. At this time, the foreign matter removing mechanism 300 also swings and moves to the upstream side in the transport direction of the recording sheet S, so that the falling position of the paper dust falling from the foreign matter removing mechanism 300 also moves to the upstream side. On the other hand, the partition member 201 is fixed to the transport guide 103 and does not move.

When the driven roller 101 is separated from the drive roller 102, the transport path 104 of the recording sheet S is exposed to the foreign matter removing mechanism 300 on the upstream side of the tip 201a of the partition member 201 in the transport direction of the recording sheet S. However, as described above, while the falling position of the paper dust moves to the upstream side in the transport direction of the recording sheet S, the partition member 201 does not move, so that the paper dust does not enter the transport path 104 of the recording sheet S. It can be prevented with high accuracy.

[3] Modified Examples Although the present disclosure has been described above based on the embodiments, it goes without saying that the present disclosure is not limited to the above-described embodiments, and the following modified examples can be implemented. ..

(3-1) In the above embodiment, the image forming apparatus 1 for plunging the recording sheet S into the transport nip 501 while transporting the recording sheet S in a substantially horizontal direction has been described as an example, but it goes without saying that the present disclosure is not limited to this. Alternatively, as shown in FIG. 6, the present disclosure may be applied to the image forming apparatus 1 that causes the recording sheet S to enter the transport nip 501 while transporting the recording sheet S in the substantially vertical direction.

For example, when the recording sheet S is transported from the bottom to the top and plunged into the transport nip 501, the swing shaft 212 of the driven roller 101 is arranged below the driven roller 101 in the vertical direction, and the swinging shaft 212 is arranged. By swinging the driven roller 101 with the shaft 212 as the swing center, the driven roller 101 and the driving roller 102 are pressed and separated from each other. The foreign matter removing mechanism (not shown) 300 swings together with the driven roller 101.

The transfer guide 103 guides the recording sheet S from below to above toward the transfer nip 501. The partition member (not shown) 201 is fixed to the side of the transport guide 103 opposite to the transport path 104, and projects from the upper end of the transport guide 103 toward the transport nip 501. Therefore, when the driven roller 101 is separated from the driving roller 102, the foreign matter removing mechanism 300 moves downward.

On the other hand, since the position of the long side 201a of the partition member 201 is fixed, the partition member 201 partitions the foreign matter removing mechanism 300 and the transport path 104 at the time of separation. Therefore, the partition member 201 can prevent the paper dust from scattering from the foreign matter removing mechanism 300 to the transport path 104 when separated.

When the driven roller 101 is pressed against the driving roller 102, the position of the foreign matter removing mechanism 300 is higher than when the driven roller 101 is separated. However, at the time of pressure welding, not only the partition member 201 partitions between the foreign matter removing mechanism 300 and the transport path 104, but also the long side 201a of the partition member 201 comes into contact with the outer peripheral surface of the driven roller 101, so that the driven roller 101 is also It will partition between the foreign matter removing mechanism 300 and the transport path 104. Therefore, it is possible to prevent paper dust from entering the transport path 104 from the foreign matter removing mechanism 300.

As described above, even when the recording sheet S is vertically transported, the same effect as that of the above-described embodiment can be obtained by applying the present disclosure.

(3-2) In the above embodiment, the case where the foreign matter removing mechanism 300 includes two foreign matter removing members of the foamed sponge 301 and the thin film 302 has been described as an example, but the present disclosure is not limited to this. Needless to say, the number of foreign matter removing members included in the foreign matter removing mechanism 300 may be one or three or more.

Further, it goes without saying that the positional relationship between the foamed sponge 301 and the thin film 302 is not limited to the positional relationship in the above-described embodiment, and the positional relationship may be different from the positional relationship in the above-described embodiment. Further, even when a foreign matter removing member other than the film and sponge is used such as a foreign matter removing brush, the same effect can be obtained by applying the present disclosure.

(3-3) In the above embodiment, the case where the partition member 201 is a film has been described as an example, but it goes without saying that the present disclosure is not limited to this, and the partition member 201 is a member other than a film such as a sponge. May be used. Even if a member other than the film is used, it is possible to prevent foreign matter such as paper dust from entering the transport path 104.

(3-4) In the above embodiment, the case where the long side 201a of the partition member 201 comes into contact with the outer peripheral surface of the driven roller 101 while the driven roller 101 is pressed against the driving roller 102 has been described as an example. Needless to say, the present disclosure is not limited to this, and the long side 201a does not have to be in contact with the outer peripheral surface of the driven roller 101.

However, the larger the distance between the long side 201a and the outer peripheral surface of the driven roller 101 at the time of pressure welding, the more difficult it becomes to prevent the paper dust from entering the transport path 104. Therefore, it goes without saying that it is desirable that the distance between the long side 201a and the outer peripheral surface of the driven roller 101 is as narrow as possible.

(3-5) In the above embodiment, the case where only the driven roller 101 swings and the drive roller 102 does not swing has been described as an example, but it goes without saying that the present disclosure is not limited to this. The drive roller 102 may be swung in addition to the driven roller 101 according to the pressure contact separation between the 101 and the drive roller 102.

Further, instead of swinging the driven roller 101, the driven roller 101 and the driving roller 102 may be pressed apart from each other by swinging the driving roller 102 without swinging the driven roller 101. In any case, by providing a partition member 201 that partitions between the foreign matter removing mechanism 300 for removing foreign matter such as paper dust from the outer peripheral surface of the roller to be swung and the transport path 104 of the recording sheet S, the paper dust or the like is provided. It is possible to prevent foreign matter from entering the transport path 104 and deteriorating the image quality.

(3-6) In the above embodiment, the case where paper dust is removed from the outer peripheral surface of the resist roller has been described as an example, but it goes without saying that the present disclosure is not limited to this, and a transport roller other than the resist roller is used. Even so, the same effect can be obtained by applying the present disclosure. For example, if the present disclosure is applied to a transport roller provided by the automatic document transport device 142 for transporting a document, FD streaks (FD: Feeding Direction. It is possible to prevent the generation of streak-like image noise).

(3-7) In the above embodiment, the case where the driven roller 101 is swung around the swing shaft 212 to be pressed and separated from the drive roller 102 has been described as an example, but the present disclosure is not limited to this. Needless to say, instead of this, the driven roller 101 may be pressure-welded and separated from the drive roller 102 by a method other than rocking. For example, the driven roller 101 may be translated and separated from the driving roller 102.

For example, a bearing member that supports the rotation axis of the driven roller 101 is supported by a guide member so that the driven roller 101 can reciprocate between a pressure contact position and a separation position, and the bearing is supported by an elastic member such as a spring. By urging the member, the driven roller 101 is urged toward the pressure contact position. Further, even if the bearing member is reciprocated by using the eccentric cam, the driven roller 101 can be pressed and separated from the drive roller 102.

Similarly, for the foreign matter removing mechanism 300, instead of swinging around the swing shaft 212, when the driven roller 101 is pressure-welded and separated from the drive roller 102, the swing shaft other than the swing shaft 212 is used as the center. It may be swung or may be translated. In this way, the relative positional relationship between the driven roller 101 and the foreign matter removing mechanism 300 can be kept constant. Further, as compared with the case where the driven roller 101 and the foreign matter removing mechanism 300 are translated by using individual mechanisms, the device can be downsized and the cost can be reduced.

When the driven roller 101 is pressed and separated from the driving roller 102, the relative positional relationship between the driven roller 101 and the foreign matter removing mechanism 300 changes, and the foam sponge 301 and the thin film 302 are moved to the outer peripheral surface of the driven roller 101. When separated from, foreign matter such as paper dust sandwiched between the foam sponge 301 or the thin film 302 and the outer peripheral surface of the driven roller 101 is likely to fall.

On the other hand, if the relative positional relationship between the driven roller 101 and the foreign matter removing mechanism 300 is maintained constant, the foamed sponge 301 and the thin film 302 are maintained in contact with the outer peripheral surface of the driven roller 101. Can be done. Therefore, it is possible to reduce the amount of foreign matter such as paper dust falling.

(3-8) In the above embodiment, a case where foreign matter such as paper dust adhering to the outer peripheral surface of the driven roller 101 is removed by using the foreign matter removing mechanism 300 has been described as an example, but the present disclosure is limited to this. Needless to say, foreign matter adhering to the outer peripheral surface of the drive roller 102 may be removed by the foreign matter removing mechanism 300 instead of the driven roller 101 or together with the driven roller 101.

In this case, if the partition member 201 is fixed on the side of the transport guide 105 on the drive roller 102 side opposite to the transport path 104, it is possible to prevent foreign matter from entering the transport path 104 from the foreign matter removing mechanism 300. .. In particular, it is effective when the drive roller 102 is arranged above the transport path 104 in the vertical direction.

(3-9) In the above embodiment, the case where the image forming apparatus 1 is a tandem color multifunction device has been described as an example, but it goes without saying that the present disclosure is not limited to this. It may be a color multifunction device or a monochrome multifunction device. Further, the present disclosure may be applied to a single-function device such as a printer device, a scanner device, a copying device, or a facsimile device, and even in that case, the effect described in the above embodiment can be obtained.

The sheet transfer device and the image forming device according to the present disclosure are useful as devices capable of preventing foreign matter collected from a transfer roller pair that can be pressure-welded and separated from entering the transfer path when the transfer roller pair is separated. Is.

1 ... Image forming apparatus 100 ... Resist roller unit 101 ... Driven roller 102 ... Drive roller 103 ... Transfer guide (driven roller 101 side)
104 ... Transfer path 105 of recording sheet S ... Transfer guide (drive roller 102 side)
201 ... Partition member 300 ... Foreign matter removing mechanism 301 ... Foam sponge 302 ... Thin film 303 ... Support member 501 ... Conveying nip

Claims (9)

A pair of transport rollers that can be separated by pressure welding and transport the sheet along the transport path during pressure welding.
Among the transport roller pairs, a foreign matter removing mechanism for removing foreign matter adhering to the outer peripheral surface of the movable roller that is displaced from the pressure contact position to the separated position.
A moving means for moving the foreign matter removing mechanism together with the movable roller to the separation position side,
A partition member for partitioning the inside of the path and the outside of the path for locating the foreign matter removing mechanism outside the path of the transport path is provided.
A sheet transfer device, characterized in that the partition member is immovable regardless of a pressure contact separation state of the transfer roller pair. When the partition member is pressed against the transport roller pair, the outer circumference of the outer peripheral surface of the movable roller is located along the rotation direction from the removal action position of the foreign matter removing mechanism to the transport nip of the transport roller pair. It comes into contact with the surface portion and removes foreign matter adhering to the outer peripheral surface.
The sheet transfer device according to claim 1, wherein the contact position is set and adjusted to a position close to the transfer nip within a range that does not interfere with the transfer of the sheet. The second aspect of the present invention, wherein the partition member is in contact with the outer peripheral surface in a posture from the upstream side to the downstream side of the contact position with the movable roller in the rotation direction of the movable roller. Sheet transfer device. The moving means swings the movable roller between the pressure contact position and the separated position with the upstream side of the transport roller pair in the sheet transport direction as the swing center, and
The sheet transport device according to any one of claims 1 to 3, wherein the foreign matter removing mechanism is swung together with the movable roller. The foreign matter removing mechanism includes a plurality of foreign matter removing members made of different materials from each other.
The sheet transport device according to any one of claims 1 to 4, wherein the plurality of foreign matter removing members are brought into contact with the outer peripheral surface of the movable roller to remove the foreign matter. The plurality of foreign matter removing members are a thin-walled film and a continuous foam foam sponge.
The tip of the thin-walled film is brought into contact with the outer peripheral surface of the movable roller to scrape off foreign matter, and at the same time.
The sheet transport device according to claim 5, wherein the foamed sponge is pressed against the outer peripheral surface to wipe off foreign matter. A plate-shaped inrush guide for guiding the sheet to the transport nip of the transport roller pair along the transport path is provided.
The sheet transport device according to any one of claims 1 to 5, wherein the partition member is fixed to a surface of the plunge guide opposite to the transport path. The sheet transport device according to any one of claims 1 to 7 is provided.
An image forming apparatus characterized in that a sheet to be used for image forming is conveyed using the sheet conveying device. A transfer unit for transferring an image to the sheet is provided.
The image forming apparatus according to claim 8, wherein the transfer roller pair is a resist roller arranged on the upstream side of the transfer portion in the sheet transfer direction and adjusting the transfer timing of the sheet.

Images