JP7163089B2 - Sheet conveying device and image forming device - Google Patents

Description

The present invention relates to a sheet conveying device for conveying sheets and an image forming apparatus having the same.

Generally, an electrophotographic printer transfers a toner image formed on a photosensitive drum onto a sheet fed from a cassette, fixes the toner image on the sheet, and then ejects the sheet. Paper dust may be generated on the sheet due to rubbing between the conveying roller, the separation pad, and the like, and the paper dust adheres to the photosensitive drum and toner, resulting in deterioration of image quality.

2. Description of the Related Art Conventionally, an image forming apparatus includes a first paper dust removing roller that contacts a sheet to trap paper dust on the sheet, and a first sponge member that scrapes paper dust adhering to the first paper dust removing roller. proposed (see Patent Document 1). In this image forming apparatus, paper dust is scraped off by the first sponge member when the first paper dust removing roller rotates in the forward rotation direction. , the paper dust scraped by the first sponge member may flow back into the conveying path. For this reason, a first reverse-conveyance prevention member is provided upstream of the first sponge member in the forward rotation direction of the first paper dust removing roller to scrape paper dust from the first paper dust removing roller. When the first paper dust removing roller rotates in the reverse direction, the paper dust is scraped off by the first reverse transport prevention member.

Between the first paper dust removing roller and the first reverse conveyance prevention member, there is provided a mechanism that inhibits scraping of paper dust by the first sponge member when the first paper dust removing roller rotates in the normal rotation direction. A small gap is provided to prevent this. This gap allows paper dust to be transported toward the first sponge member when the first paper dust removing roller rotates in the forward direction, and allows the paper dust to be conveyed toward the first sponge member when the second paper dust removing roller rotates in the reverse direction. When the paper dust is present, the paper dust is restricted from being transported toward the transport path as a lump to some extent.

JP-A-2003-267579

However, although the first reverse-conveyance prevention member described in Patent Document 1 can restrict the conveyance of large clumps of paper dust, for example, small-sized paper dust whose main component is the filler of the sheet, etc. Sometimes it slips through. As a result, there is a risk that paper dust that has slipped through this gap will adhere to the photosensitive drum or toner, resulting in an image defect.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a sheet conveying apparatus and an image forming apparatus that reduce backflow of paper dust by restricting rotation of the rotating body in the second direction, thereby solving the above-described problems.

According to the present invention, a sheet conveying apparatus includes a rotating body and a facing member that faces the rotating body and forms a conveying nip together with the rotating body. a conveying portion that conveys a sheet in a conveying nip; a contact member that contacts the surface of the rotating body and scrapes off paper dust adhering to the surface; and a second direction opposite to the first direction of the rotating body. a rotation restricting mechanism capable of restricting rotation in a direction , wherein the rotation restricting mechanism includes a first engaging portion that rotates integrally with the rotating body; a second engaging portion for restricting rotation of the rotating body in the second direction; an urging portion that urges the other of the first engaging portion and the second engaging portion to be engaged; a moving part that resists and separates one of the first engaging part and the second engaging part from the other of the first engaging part and the second engaging part , characterized in that

According to the present invention, since the rotation of the rotating body in the second direction is restricted, image defects can be prevented.

1 is an overall schematic diagram showing a printer according to a first embodiment; FIG. 2A is a plan view showing the sheet conveying device, and FIG. 2B is a view taken along the line AA in FIG. (a) is a plan view showing a state in which the first ratchet and the second ratchet are separated according to the second embodiment, and (b) is a plan view showing a state in which the first ratchet and the second ratchet are engaged. BB arrow view of FIG. 3 (a). The figure which shows the 2nd ratchet based on a 1st modification. The top view which shows the convex part formed in the cassette which concerns on a 2nd modification.

<First Embodiment>
〔overall structure〕
First, a first embodiment of the present invention will be described. A printer 1 as an image forming apparatus is an electrophotographic laser beam printer that forms a monochrome toner image. As shown in FIG. 1, the printer 1 includes a sheet feeding device 100 that feeds stacked sheets, and a sheet conveying device 10 that conveys the sheets fed by the sheet feeding device 100. there is The printer 1 also includes an image forming unit 300 that forms an image on the sheet conveyed by the sheet conveying device 10 , a fixing device 500 that fixes the image transferred onto the sheet, and a discharge tray 700 capable of discharging the sheet. and a roller pair 600 .

When an image forming job is output to the printer 1 , an image forming process by the image forming section 300 is started based on image information input from an external computer or the like connected to the printer 1 . The image forming section 300 has a process cartridge 300 a , a laser scanner 400 and a transfer roller 302 . The process cartridge 300a has a photosensitive drum 301 that rotates in the direction of the arrow, and a charging roller, a developing roller, and a cleaning blade (not shown) arranged along the photosensitive drum 301 . The photosensitive drum 301 and transfer roller 302 form a transfer nip T1. The process cartridge 300a is detachable from the apparatus main body 1A of the printer 1. As shown in FIG.

The laser scanner 400 irradiates the photosensitive drum 301 with laser light based on the input image information. At this time, the photosensitive drum 301 is charged in advance by the charging roller, and an electrostatic latent image is formed on the photosensitive drum 301 by being irradiated with laser light. After that, the developing roller develops the electrostatic latent image to form a monochrome toner image on the photosensitive drum 301 .

The sheet S is fed from the sheet feeding device 100 in parallel with the image forming process described above. The sheet feeding apparatus 100 includes a cassette 101 that can be pulled out from and attached to the apparatus main body 1A, and a middle plate 104 that can support the sheets S stored in the cassette 101 and can be raised around a rotation shaft 104a. have. The intermediate plate 104 rotates upward, for example, when an image forming job is input, and the uppermost sheet stacked on the intermediate plate 104 comes into contact with the feeding roller 102 . Then, the intermediate plate 104 rotates downward when the image forming job is completed. The intermediate plate 104 may be urged upward by a spring (not shown), and pressed downward by a cam (not shown) against the urging force of the spring each time one sheet is fed.

The sheet S supported by the intermediate plate 104 is fed by the feeding roller 102 , and the sheet S fed by the feeding roller 102 is separated one by one by the separation mechanism 103 . As shown in FIG. 2B, the separation mechanism 103 includes a holder 103b rotatable about a rotation shaft 103d with respect to the apparatus main body 1A, a separation pad 103a fixed to the holder 103b, and a separation holder 103b. and a separation spring 103c that biases the . The separation pad 103a is pressed against the feeding roller 102 by the biasing force of the separation spring 103c.

The sheet S fed by the feeding roller 102 is handled by the separation nip N1 formed by the feeding roller 102 and the separation pad 103a and separated one by one. At this time, paper dust may be generated on the surface of the sheet S due to sliding between the feeding roller 102 and the separation pad 103a. Paper dust generated on the surface of the sheet S is collected by the sheet conveying device 10, which will be described later.

The sheet S conveyed by the sheet conveying device 10 is guided to the registration roller pair 200 by the conveying path 210 and hits the nip of the registration roller pair 200 in the stopped state, thereby correcting the skew. The registration roller pair 200 conveys the sheet S in synchronization with the transfer timing of the toner image in the transfer nip T1.

The toner image on the photosensitive drum 301 is transferred to the sheet S conveyed by the registration roller pair 200 at the transfer nip T1 due to the electrostatic load bias applied to the transfer roller 302 . Residual toner remaining on the photosensitive drum 301 is collected by a cleaning blade. The fixing device 500 applies predetermined heat and pressure to the sheet S onto which the toner image has been transferred, thereby melting and fixing (fixing) the toner. The fixing device 500 has a heating roller 501 having a heater (not shown) and a pressure roller 502 . After passing through the fixing device 500 , the sheet S is discharged onto the discharge tray 700 by the discharge roller pair 600 .

When images are formed on both sides of the sheet S, the sheet S with the image formed on the first side is switched back by the reversing roller pair 800 and conveyed to the double-sided conveying path CP. The double-sided conveying path CP guides the sheet S to the registration roller pair 200 again. An image is formed on the second surface of the sheet S at the transfer nip T1, and the sheet S is discharged onto the discharge tray 700. FIG.

[Sheet Conveying Device]
Next, the sheet conveying device 10 will be described in detail with reference to FIGS. 1 and 2. FIG. As shown in FIGS. 1 and 2, the sheet conveying device 10 includes a drive roller 108 driven by a motor (not shown), a paper dust collection roller 106 which is driven to rotate in contact with the drive roller 108, and a one-way clutch 107b which will be described later. and have A driving roller 108 as a facing member forms a conveying nip N2 together with the paper dust collecting roller 106 so as to face the paper dust collecting roller 106 as a rotating body. The driving roller 108 and the paper dust collecting roller 106 constitute a conveying section 900 that conveys the sheet at the conveying nip N2.

As shown in FIGS. 2A and 2B, the frame 50 of the apparatus main body 1A is provided with ribs 105a, and bearings 107a are fixed to the ribs 105a. A one-way clutch 107b as a rotation restricting mechanism is press-fitted into the bearing 107a. More specifically, the one-way clutch 107b is arranged coaxially with the rotating shaft 106c, allows the paper dust collecting roller 106 to rotate in the normal rotation direction R1, and rotates the paper dust collecting roller 106 in the opposite direction to the normal rotation direction R1. Rotation in the reverse direction R2 is restricted. When the drive roller 108 rotates the paper dust collecting roller 106 in the forward rotation direction R1 as the first direction, the sheet is conveyed at the conveying nip N2.

The roller portion 106a of the paper dust collecting roller 106 is fixed to the central portion in the axial direction of the rotating shaft 106c. The frame 50 also has ribs 105b and 105c on the opposite side of the rib 105a across the roller portion 106a in the axial direction. is rotatably supported. That is, the rotating shaft 106c of the paper dust collecting roller 106 is supported on both sides of the roller portion 106a in the axial direction.

Further, the sheet conveying device 10 has a paper dust collecting pad 106 b as a contact member capable of coming into contact with the surface of the paper dust collecting roller 106 . The paper dust collecting pad 106b is made of a sponge member and is always in contact with the surface of the paper dust collecting roller 106. As shown in FIG. For example, the roller portion 106a of the paper dust collecting roller 106 is coated with a fluorine resin, and the paper dust collecting pad 106b is made of a nylon sponge member. When the paper dust collecting roller 106 rotates in the forward rotation direction R1, the surface of the paper dust collecting roller 106 is charged by sliding against the paper dust collecting pad 106b. More specifically, the roller portion 106a of the paper dust collecting roller 106 coated with fluororesin is easily charged negatively (-), and the paper dust collecting pad 106b made of a nylon sponge member is positively charged. easily charged.

Therefore, the paper dust generated in the separation nip N1, adhered to the surface of the sheet S, and positively charged is electrostatically attracted by the paper dust collection roller 106. FIG. The paper dust adhering to the surface of the paper dust collecting roller 106 is scraped off by the paper dust collecting pad 106b and collected in a paper dust collecting area (not shown). As a result, it is possible to prevent the paper dust from adhering to the photosensitive drum 301 and the toner, thereby reducing the image quality. In addition, by scraping off paper dust on the sheet S, slippage of the sheet S in the transfer nip T1 can be reduced, and image defects such as image misalignment in the transfer nip T1 can be prevented. In addition, since the paper dust collecting pad 106b is always in contact with the paper dust collecting roller 106, it is possible to scrape off small-sized paper dust such as fillers (for example, calcium carbonate and talc) contained in the sheet S. Image defects caused by paper dust can be prevented.

[Jam clearing operation]
Next, a jam processing operation for a jammed sheet (hereinafter referred to as a jammed sheet) held in the conveying nip N2 will be described. The user can access the jammed sheet from the upstream side or the downstream side in the sheet conveying direction (direction of arrow G in FIG. 2B). More specifically, when accessing the jammed sheet from the upstream side in the sheet conveying direction, the user pulls out the cassette 101 from the apparatus main body 1A. The direction of pulling out the cassette 101 may be either the axial direction of the paper dust collecting roller 106 (the paper surface direction in FIG. 1) or the direction orthogonal to the axial direction of the paper dust collecting roller 106 (the horizontal direction in FIG. 1). .

After pulling out the cassette 101 from the apparatus main body 1A, the user pulls out the jammed sheet sandwiched between the separation nip N1 and the conveying nip N2 to the upstream side in the sheet conveying direction. At this time, the paper dust collecting roller 106 tries to rotate in the reverse direction R2 as the second direction shown in FIG. 2B by the force received from the jam sheet. However, in this embodiment, the one-way clutch 107b restricts the paper dust collecting roller 106 from rotating in the reverse direction R2. For this reason, the paper dust collection roller 106 is in sliding contact with the jam sheet pulled out by the user while being stopped.

Since the paper dust collecting roller 106 normally rotates in the forward rotation direction R1, the paper dust removed by the paper dust collecting pad 106b is removed near or at the nip N3 between the paper dust collecting roller 106 and the paper dust collecting pad 106b. It accumulates on the upstream side in the forward rotation direction R1. Therefore, if the paper dust collecting roller 106 rotates in the reverse direction R2, the paper dust collected by the paper dust collecting pad 106b flows back into the transport path 210. FIG. In the present embodiment, the one-way clutch 107b regulates the rotation of the paper dust collecting roller 106 in the reverse direction R2. can be suppressed.

When accessing the jammed sheet from the downstream side in the sheet conveying direction, the user opens the door 1B that is openably and closably supported by the apparatus main body 1A, as shown in FIG. The door 1B rotates around a pivot point 1C with respect to the apparatus main body 1A. When the door 1B is opened, the transport path 210 is opened and the user can access the jammed sheet. When the user pulls out the jammed sheet downstream in the sheet conveying direction, the paper dust collecting roller 106 tries to rotate in the forward rotation direction R1 shown in FIG. 2B by the force received from the jammed sheet.

Since the one-way clutch 107b allows the paper dust collecting roller 106 to rotate in the normal rotation direction R1, the paper dust collecting roller 106 rotates in the normal rotation direction R1. Therefore, the resistance at the conveying nip N2 when pulling out the jammed sheet can be reduced, and the user can pull out the jammed sheet with less force.

<Second Embodiment>
Next, a second embodiment of the present invention will be described. In the second embodiment, a rotation restricting mechanism 60 is provided in place of the one-way clutch 107b of the first embodiment. Therefore, the configuration similar to that of the first embodiment will be omitted from illustration or given the same reference numerals in the drawings.

The sheet conveying device 20 has a driving roller 108 (see FIG. 1), a paper dust collecting roller 106, and a rotation restricting mechanism 60, as shown in FIG. 3A. The rotation restricting mechanism 60 includes a first ratchet 110a as a first engaging portion that is fixed to the rotating shaft 106c and rotates integrally with the rotating shaft 106c, a second ratchet 110b that can be engaged with the first ratchet 110a, and an intermediate ratchet 110a. and a projection 112 b provided on the plate 112 . As will be described later, the rotation restriction mechanism 60 is configured to be able to restrict rotation of the paper dust collecting roller 106 in the reverse direction.

Ratchet-shaped teeth 120a and 120b are formed on the first ratchet 110a and the second ratchet 110b, respectively, and the teeth 120a and 120b face each other. The second ratchet 110b is movably supported in the axial direction of the rotating shaft 106c with respect to the first ratchet 110a. A spring 111 as a biasing member is arranged between the second ratchet 110b and the rib 105e formed on the frame 50, and the second ratchet 110b is engaged with the first ratchet 110a by the biasing force of the spring 111. are biased in the direction of mating. A second ratchet 110b as a second engaging portion is supported by, for example, a rib 105d formed on the frame 50 so as to be movable in the axial direction of the rotating shaft 106c and unrotatable in the forward rotation direction R1 and the reverse rotation direction R2. It is

The intermediate plate 112 as a sheet support portion is rotatably supported by the cassette 101 (see FIG. 1) and has a support surface 112a capable of supporting the sheet. Further, the intermediate plate 112 has a convex portion 112b as a moving portion that is arranged directly below the second ratchet 110b and extends downstream in the sheet conveying direction. As shown in FIG. 4, a cam surface 130b is formed at a position facing the convex portion 112b of the second ratchet 110b. The cam surface 130b is an inclined surface that slopes downward in the arrow D direction. The direction of arrow D is the direction away from the first ratchet 110a, that is, the direction opposite to the biasing direction of the spring 111 in the axial direction of the rotating shaft 106c.

The ratchet-shaped teeth 120b are formed of a first surface 71 extending in the axial direction of the rotating shaft 106c and a second surface 72 extending in a direction crossing the axial direction. The second surface 72 extends toward the first ratchet 110a as it goes downstream in the normal rotation direction R1. A plurality of ratchet-shaped teeth 120b thus formed are formed in the circumferential direction. The ratchet-shaped teeth 120a formed on the first ratchet 110a are similarly formed so as to be meshable with the ratchet-shaped teeth 120b. Therefore, when the first ratchet 110a tries to rotate in the reverse direction R2, the first surfaces 71 of the teeth 120a and 120b mesh with each other, so that the rotation of the first ratchet 110a in the reverse direction R2 is restricted.

On the other hand, when the first ratchet 110a rotates in the forward rotation direction R1, the second ratchet 110b resists the biasing force of the spring 111 because the second surfaces 72 of the ratchet-shaped teeth 120a and 120b are in sliding contact. is pressed down. Therefore, the rotation of the first ratchet 110a in the forward rotation direction R1 is not restricted, and the second ratchet 110b reciprocates in the axial direction.

[Operation of Rotation Regulation Mechanism]
Next, operation of the rotation restricting mechanism 60 will be described. When the printer 1 is on standby when no image forming job is input, the intermediate plate 112 is positioned at the lowest standby position. At this time, the convex portion 112b of the intermediate plate 112 is separated from the cam surface 130b of the second ratchet 110b, as shown in FIG. Therefore, the second ratchet 110b is engaged with the first ratchet 110a by the biasing force of the spring 111 without receiving force from the protrusion 112b (see FIG. 3B). That is, the spring 111 as the biasing portion biases the second ratchet 110b to engage the first ratchet 110a when the conveying portion 900 does not convey the sheet.

At this time, due to the engagement between the first ratchet 110a and the second ratchet 110b, the paper dust collection roller 106 rotating integrally with the first ratchet 110a is allowed to rotate in the forward rotation direction R1, and is allowed to rotate in the reverse rotation direction R2. Regulated. As a result, when the cassette 101 is pulled out and the jammed sheet is pulled out to the upstream side in the sheet transport direction, it is possible to prevent paper dust from flowing back to the transport path 210 (see FIG. 1), thereby suppressing deterioration in image quality. can be done. As in the first embodiment, the rotation regulating mechanism 60 of the present embodiment allows the paper dust collecting roller 106 to rotate in the forward rotation direction R1. Therefore, the resistance at the conveying nip N2 when pulling out the jammed sheet from the downstream side in the sheet conveying direction can be reduced, and the user can pull out the jammed sheet with less force.

When an image forming job is input to the printer 1, the intermediate plate 112 rises in the direction of arrow C in FIG. 4 from the waiting position toward the feeding position. At this time, the convex portion 112b of the intermediate plate 112 presses the cam surface 130b of the second ratchet 110b. The cam surface 130b converts the force from the protrusion 112b in the axial direction of the rotating shaft 106c, that is, in the arrow D direction. As a result, the second ratchet 110b is separated from the first ratchet 110a against the biasing force of the spring 111. As shown in FIG. That is, the convex portion 112b as the moving portion separates the second ratchet 110b from the first ratchet 110a when the conveying portion 900 conveys the sheet. Therefore, the paper dust collecting roller 106 can rotate in the forward rotation direction R1 without contacting the second ratchet 110b, and can convey the sheet.

Note that even when the first ratchet 110a and the second ratchet 110b are engaged, the paper dust collecting roller 106 can rotate in the forward rotation direction R1. However, as the paper dust collecting roller 106 rotates in the forward direction R1, the ratchet-shaped teeth 120a and 120b repeatedly come into contact and separate from each other, resulting in abnormal noise. In the present embodiment, the second ratchet 110b is separated from the first ratchet 110a when the conveying unit 900 conveys the sheet. Therefore, the sheet can be conveyed without generating abnormal noise. can. On the other hand, if the abnormal noise is not a concern or if countermeasures against abnormal noise are taken, the projection 112b may not be provided and the first ratchet 110a and the second ratchet 110b may not be separated by the projection 112b. .

[Modification]
Next, a modified example of this embodiment will be described. The teeth of the first ratchet 110a and the second ratchet 110b are not limited to the ratchet shape. That is, as shown in FIG. 5, the teeth 160b of the second ratchet 110b may be rectangular when viewed from the radial direction. The teeth of the first ratchet 110a are also formed in the same shape as the teeth 160b. This is a so-called dog clutch configuration. In such a configuration, when the first ratchet 110a and the second ratchet 110b are engaged, the paper dust collecting roller 106 is restricted from rotating in the forward rotation direction R1 and the reverse rotation direction R2.

Furthermore, the protrusion 112b capable of pressing the second ratchet 110b may be provided at a location other than the intermediate plate 112. FIG. That is, as shown in FIG. 6, a convex portion 112c as a moving portion may be provided on the cassette 101 as the sheet storage portion. In this case, when the cassette 101 is attached to the apparatus main body 1A, the convex portion 112c as the moving portion provided on the cassette 101 presses the cam surface 130b of the second ratchet 110b against the biasing force of the spring 111. . Accordingly, when the conveying unit 900 conveys a sheet, the first ratchet 110a and the second ratchet 110b are separated from each other, and the sheet can be conveyed without generating abnormal noise. Further, when the cassette 101 is pulled out from the apparatus main body 1A, the biasing force of the spring 111 engages the first ratchet 110a and the second ratchet 110b. As a result, the rotation of the paper dust collecting roller 106 in the reverse direction R2 can be regulated, and the backflow of paper dust into the transport path 210 can be reduced.

In addition, in the first embodiment, the one-way clutch 107b may be provided between the rotating shaft 106c and the roller portion 106a. In this case, the roller portion 106a corresponds to the rotating body. Also, the configuration of the one-way clutch 107b is not limited, and various one-way clutches such as sprag type and cam type can be applied.

Further, in the second embodiment, the intermediate plate 112 is raised from the waiting position to the feeding position when an image forming job is input, but the present invention is not limited to this. For example, the intermediate plate 112 may be raised when the cassette 101 is attached to the apparatus main body 1A. Further, the first ratchet 110a and the second ratchet 110b are not limited to being separated from each other by a protrusion provided on the intermediate plate or the cassette. may

Furthermore, in the second embodiment, the second ratchet 110b is configured to move relative to the first ratchet 110a. good. For example, the first ratchet 110a may be spline-engaged with the rotating shaft 106c and configured to be movable in the axial direction. That is, any one of the first ratchet 110a and the second ratchet 110b may be configured to be movable with respect to the other. Further, the moving direction of the second ratchet 110b is not limited to the axial direction of the rotating shaft 106c, and may be another direction. For example, the second ratchet 110b may move radially into engagement with the first ratchet 110a.

In any of the above-described embodiments, the paper dust collecting roller 106 receives the force to rotate in the reverse direction R2 not only when the jammed sheet is pulled out from the upstream side in the sheet conveying direction, but also when the user directly Powder collection roller 106 may be rotated.

Further, in any of the above-described embodiments, the member that forms the conveying nip N2 together with the paper dust collecting roller 106 is not limited to the drive roller 108, and may be a non-rotating member such as a separation pad. In this case, a drive (not shown) is input to the paper dust collecting roller 106 .

In addition, although the electrophotographic printer 1 has been used in each of the above-described embodiments, the present invention is not limited to this. For example, the present invention can also be applied to an inkjet image forming apparatus that forms an image on a sheet by ejecting ink liquid from nozzles.

1: Image forming apparatus (printer)/1A: Apparatus main body/10, 20: Sheet conveying device/60: Rotation regulating mechanism/101: Sheet storage section (cassette)/106: Rotating member (paper dust collecting roller)/106b: Abutting member (paper dust collecting pad)/106c: Rotating shaft/107b: Rotation restricting mechanism (one-way clutch)/108: Opposing member (driving roller)/110a: First engaging portion (first ratchet)/110b: Second 2 engaging portion (second ratchet)/111: biasing portion (spring)/112: seat support portion (middle plate)/112b, 112c: moving portion (convex portion)/120a, 120b: ratchet-like teeth/130b : Cam surface/160b: Teeth/300: Image forming unit/N2: Conveying nip/R1: First direction (forward direction)/R2: Second direction (reverse direction)

Claims (9)

A conveying unit including a rotating body and a facing member that forms a conveying nip with the rotating body so as to face the rotating body, and conveys a sheet in the conveying nip when the rotating body rotates in a first direction. When,
a contact member that contacts the surface of the rotating body and scrapes off paper dust adhering to the surface;
a rotation restriction mechanism capable of restricting rotation of the rotating body in a second direction opposite to the first direction ;
The rotation restricting mechanism is
a first engaging portion that rotates integrally with the rotating body;
a second engaging portion that restricts rotation of the rotating body in the second direction by engaging with the first engaging portion;
When the conveying portion does not convey the sheet, one of the first engaging portion and the second engaging portion is engaged with the other of the first engaging portion and the second engaging portion. an urging unit that urges the
When the conveying section conveys the sheet, one of the first engaging section and the second engaging section is engaged against the biasing force of the biasing section. and a moving part that separates from either one of the two engaging parts,
A sheet conveying device characterized by: further comprising a seat support that supports the seat and can be lifted from the standby position;
The moving portion is provided on the seat support portion, and moves one of the first engaging portion and the second engaging portion to the biasing portion by raising the supporting portion from the standby position. pressing against a biasing force;
2. The sheet conveying apparatus according to claim 1 , wherein: an apparatus main body that supports the conveying section and the contact member;
a sheet storage unit that stores a sheet and can be pulled out and attached to the apparatus main body;
The moving portion is provided in the sheet accommodating portion and biases one of the first engaging portion and the second engaging portion when the sheet accommodating portion is attached to the apparatus main body. pressing against the biasing force of the
2. The sheet conveying apparatus according to claim 1 , wherein: Either one of the first engaging portion and the second engaging portion is movable in the axial direction of the rotating body, and has a cam surface that converts force from the moving portion in the axial direction,
4. The sheet conveying device according to any one of claims 1 to 3 , characterized in that: The first engaging portion and the second engaging portion each have ratchet-shaped teeth that can mesh with each other,
The rotation restricting mechanism permits the rotating body to rotate in the first direction and rotates the rotating body in the first direction when the first engaging portion and the second engaging portion are engaged with each other. restrict rotation in two directions,
The sheet conveying apparatus according to any one of claims 1 to 4 , characterized in that: The first engaging portion and the second engaging portion have teeth that mesh with each other when rotating in the first direction and the second direction,
The rotation restricting mechanism restricts rotation of the rotating body in the first direction and the second direction when the first engaging portion and the second engaging portion are engaged.
The sheet conveying apparatus according to any one of claims 1 to 4 , characterized in that: The moving portion separates the second engaging portion from the first engaging portion against the biasing force of the biasing portion,
The sheet conveying device according to any one of claims 1 to 6 , characterized in that: The facing member is a drive roller,
The rotating body is a roller driven to rotate by the drive roller.
The sheet conveying device according to any one of claims 1 to 7 , characterized in that: A sheet conveying device according to any one of claims 1 to 8 ;
an image forming unit that forms an image on the sheet;
An image forming apparatus characterized by:

Images