JP2023146482A - Medium guide device, image forming device, image reading device, and post-processing device - Google Patents

Abstract

To provide a medium guide device capable of suppressing an occurrence of collision noise caused by bouncing up of a rear end of a medium while ensuring smooth conveyance of the medium on a curved path.SOLUTION: A medium guide device 35 includes: an upstream roller pair 42 and a downstream roller pair 43 provided in a curved path 6A; a first rib 44 protruding from/withdrawing to outside in a radial direction of the curved path 6A on an upstream side of an apex portion 6T; a second rib 45 protruding from/withdrawing to inside in the radial direction of the curved path 6A on a downstream side of the apex portion 6T; and an interlocking part 46 interlocking the first rib 44 with the second rib 45, wherein when paper P being conveyed by the upstream roller pair 42 is in a first conveyance state S1 where it is away from the downstream roller pair 43, the interlocking part 46 withdraws the first rib 44 and protrudes the second rib 45, and when the paper P is in a second conveyance state where the paper P is conveyed by the downstream roller pair 43, the interlocking part 46 protrudes the first rib 44 and withdraws the second rib 45.SELECTED DRAWING: Figure 3

Description

The present invention relates to a medium guiding device, an image forming device, an image reading device, and a post-processing device that guide a conveyed medium.

For example, the image forming apparatus described in Patent Document 1 is provided with a paper guide device that guides a paper conveyed along a paper conveyance path. This paper guide device included a guide roller that rotates in contact with a conveyance roller and a movable rib that is supported by the guide roller via a floating shaft. When the diameter of the conveyance roller increases or decreases, the guide roller and the movable rib move in and out of the paper conveyance path, and the movable rib is said to be kept at an appropriate position relative to the nip between the conveyance roller and the guide roller.

Japanese Patent Application Publication No. 2004-345746

Here, a configuration in which roller pairs are provided on the upstream side and the downstream side of a curved conveyance path (curved path) will be considered. The paper is conveyed while being sandwiched between the pair of upstream rollers (nip conveyance), and is conveyed while being curved along the outer diameter surface of the curved path (hereinafter referred to as the "first state"). As the conveyance progresses and the paper continues to be nip-transported by the upstream roller pair and begins to be nip-transported by the downstream roller pair, the paper is drawn radially inward from the outer diameter surface of the curved path and is drawn to the inner diameter surface. (hereinafter referred to as the "second state (early stage)"). Conveyance further progresses, and the trailing edge of the sheet passes through the upstream roller pair (nip conveyance is completed), and is in a state where it is nip conveyed by the downstream roller pair (hereinafter referred to as the "second state (late stage)"). When this happens, the stiffness of the curved paper causes the trailing edge of the paper to spring up to the outside of the curved path in the radial direction. Then, the trailing edge of the paper slams against the outer diameter surface of the curved path, producing a collision sound.

In the first state, it is preferable that the upstream side of the curved path is a wide path, and that there is a rib that presses the paper from the inside in the radial direction on the downstream side of the curved path. Thereby, it is possible to ensure smooth conveyance of the paper without hindering the conveyance of the paper along the outer diameter surface of the curved path. On the other hand, in the second state (first half, second half), it is preferable that the downstream side of the curved path is a wide path, and that there is a rib that presses the paper from the outside in the radial direction on the upstream side of the curved path. Thereby, it is possible to suppress the occurrence of collision noise caused by the rear end of the sheet jumping up.

However, since the technology described in Patent Document 1 maintains the position of the movable rib with respect to the nip regardless of the diameter of the conveyance roller, the technology described in Patent Document 1 is applied to a curved path. However, while ensuring smooth conveyance of the paper in both the first state and the second state, it was not possible to suppress the collision noise caused by the rear end of the paper bouncing up.

In consideration of the above circumstances, the present invention provides a medium guiding device, an image forming device, and an image reading device that are capable of suppressing the occurrence of collision noise caused by the rear end of the medium bouncing up while ensuring smooth conveyance of the medium on a curved path. Provides equipment and post-processing equipment.

The medium guide device according to the present invention is provided in a conveyance path including a curved path for conveying the medium while being curved, and is provided upstream of the apex of the curved path in the conveyance direction of the medium, and rotates while sandwiching the medium. a pair of upstream rollers that are provided on the conveying path downstream of the apex in the conveying direction and that convey the medium by rotating while sandwiching the medium; It is provided so as to be able to appear in and out of the curved path from the outside in the radial direction of the curved path on the downstream side of the pair in the conveying direction and the upstream side of the apex portion in the conveying direction. A first rib that contacts the medium, and a first rib that can appear and retract from the curved path from the inside in the radial direction of the curved path on the upstream side of the downstream roller pair in the conveyance direction and the downstream side of the apex portion in the conveyance direction. a second rib provided in the curved path and in contact with the medium in a state of protruding into the curved path; and an interlocking portion that interlocks the first rib and the second rib to move in and out of the curved path, When the medium being conveyed while being sandwiched between the upstream roller pair is in a first conveying state in which it is separated from the downstream roller pair, the interlocking section retracts the first rib from the curved path and When the medium is in a second transport state in which the second rib is projected onto the curved path and the medium is transported while being sandwiched between the pair of downstream rollers, the interlocking section causes the first rib to project onto the curved path; The second rib is retracted from the curved path.

In this case, the interlocking part includes a first link part that is attached to the first rib and rotatable around the first axis, and a first link part that is attached to the second rib and rotatable around the second axis. a second link part provided in the main link part and rotatably and slidably connected to the first link part, and a biasing member that directly or indirectly biases the first rib or the second rib. and when in the first conveyance state, the biasing force of the biasing member is such that the first rib is retracted from the curved path and the second rib is projected into the curved path. When the first link part and the second link part are rotated and the second transport state is in the second transport state, the second rib is pressed by the medium being transported, and while the second link part is rotated, the second link part is rotated. It is preferable that the first link part is moved away from the curved path against the biasing force of the biasing member, and the first link part is slid relative to the second link part to cause the first rib to protrude into the curved path. .

In other cases, the interlocking unit includes a driving unit that causes the first rib to appear and retract from the curved path, a detection unit that detects the second rib that has retreated from the curved path, and a detection unit that moves the second rib to the curved path. and a biasing member that biases the biasing member to protrude, and when in the first conveyance state, the drive unit retracts the first rib from the curved path, and the second rib retracts the biasing member from the curved path. When the second rib is in the second transport state, the second rib is pressed by the medium being transported and retreats from the curved path against the urging force of the urging member. However, the driving section may cause the first rib to protrude into the curved path based on the sensing section detecting the retracted second rib.

In other cases, the interlocking unit includes a first drive unit that causes the first rib to move in and out of the curved path, a second drive unit that causes the second rib to move in and out of the curved path, and a pair of downstream rollers that a detection unit that detects that the medium is being conveyed, and when in the first conveyance state, the first drive unit retracts the first rib from the curved path, and the second drive unit causes the second rib to protrude into the curved path, and when in the second conveyance state, the first drive section detects conveyance of the medium by the downstream roller pair. The first rib may be made to protrude into the curved path, and the second drive unit may retract the second rib from the curved path.

In these cases, the first rib and the second rib may be provided so as to be rotatable around an axis while contacting the medium.

An image forming apparatus according to the present invention includes any one of the medium guide devices described above.

An image reading device according to the present invention includes any one of the medium guide devices described above.

A post-processing device according to the present invention includes any one of the above-mentioned medium guide devices.

According to the present invention, it is possible to suppress the occurrence of collision noise caused by the rear end of the medium bouncing up while ensuring smooth conveyance of the medium on the curved path.

1 is a schematic diagram (front view) showing the internal structure of a copying machine according to an embodiment of the present invention. FIG. 1 is a front view showing a medium guide device according to a first embodiment of the present invention. FIG. 2 is a front view showing the medium guide device (first conveyance state) according to the first embodiment of the present invention. FIG. 2 is a front view showing the medium guide device (second conveyance state (first half)) according to the first embodiment of the present invention. It is a front view showing the medium guide device (second conveyance state (later stage)) according to the first embodiment of the present invention. It is a front view which shows the medium guide device (1st conveyance state) based on 2nd Embodiment of this invention. It is a front view which shows the medium guide device (2nd conveyance state) based on 2nd Embodiment of this invention. It is a front view which shows the medium guide device (1st conveyance state) based on 3rd Embodiment of this invention. It is a front view which shows the medium guide device (2nd conveyance state) based on 3rd Embodiment of this invention. FIG. 2 is a schematic diagram (front view) showing the internal structure of a copying machine according to a first modification of the first to third embodiments of the present invention. FIG. 2 is a schematic diagram (front view) showing the internal structure of a copying machine (including a post-processing device) according to a second modification of the first to third embodiments of the present invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that Fr, Rr, L, R, U, and D shown in the drawings indicate front, rear, left, right, top, and bottom. Although terms indicating directions and positions are used in this specification, these terms are used for convenience of explanation and do not limit the technical scope of the present invention.

[Multifunction device]
The multifunction device 1 will be described with reference to FIG. 1. FIG. 1 is a schematic diagram (front view) showing the internal structure of the multifunction device 1. As shown in FIG.

The multifunction device 1 includes an image forming device 1A that forms an image on paper P (medium) using an electrophotographic method, and an image reading device 1B that optically reads an image of a document and converts it into electronic data.

[Image forming device]
The image forming apparatus 1A includes an apparatus main body 2 having a substantially rectangular parallelepiped appearance. A paper feed cassette 3 for storing paper P is removably provided at the bottom of the apparatus main body 2, and a paper ejection tray 4 is provided on the upper surface of the apparatus main body 2. Note that the paper P as an example of the medium is not limited to paper, and may be any material that can be elastically bent, such as a resin sheet (film). Furthermore, in the description of the image forming apparatus 1A, the direction in which the paper P is conveyed is referred to as the "conveyance direction", and "upstream" and "downstream" and similar terms are used as "upstream" and "downstream" in the conveyance direction. It also refers to concepts similar to these.

The image forming apparatus 1A includes a toner container 10, a photosensitive drum 11, a charging device 12, a developing device 13, a transfer roller 14, an optical scanning device 15, and a fixing device 16. The toner container 10 is arranged at the upper left of the apparatus main body 2, and contains, for example, black toner (developer). The photosensitive drum 11 is provided at an intermediate portion of the first conveyance path 5 extending from the paper feed cassette 3 to the paper discharge tray 4, and is driven to rotate around an axis by a motor (not shown). The charging device 12, the developing device 13, and the transfer roller 14 are arranged around the photosensitive drum 11 in the order of the image forming process. The transfer roller 14 contacts the photosensitive drum 11 from below to form a transfer nip. The optical scanning device 15 is provided above the photoreceptor drum 11. The fixing device 16 is provided on the downstream side of the first conveyance path 5.

The upstream side of the first conveyance path 5 is curved in a substantially U-shape, and at the upstream end of the curved portion is a paper feed roller that feeds the paper P stored in the paper feed cassette 3 to the first conveyance path 5. 40 pairs are provided. A pair of conveyance rollers 41 is provided at the downstream end of the curved portion of the first conveyance path 5, and a pair of registration rollers 43 is provided downstream of the pair of conveyance rollers 41. The registration roller pair 43 temporarily blocks the conveyed paper P and corrects the inclination of the paper P (skew correction). Further, inside the apparatus main body 2, a second conveyance path 6 is provided which branches off on the downstream side of the first conveyance path 5 and merges with the upstream side of the first conveyance path 5. The second transport path 6 is provided with a plurality of transport roller pairs 42 for transporting the paper P.

[Image formation processing]
The operation of the image forming apparatus 1A will be explained. A control device (not shown) that centrally controls the multifunction peripheral 1 executes image forming processing as described below, for example, based on image data input from an external terminal.

The charging device 12 charges the surface of the photoreceptor drum 11, and the optical scanning device 15 emits scanning light based on image data to form an electrostatic latent image on the surface of the photoreceptor drum 11. The developing device 13 develops a toner image on the surface of the photoreceptor drum 11 using the toner supplied from the toner container 10 . The paper feed roller pair 40 feeds the paper P from the paper feed cassette 3 to the first conveyance path 5 one by one. The paper P is conveyed along the first conveyance path 5, skew-corrected by a pair of registration rollers 43, and enters the transfer nip. The transfer roller 14 transfers the toner image on the photosensitive drum 11 to the paper P passing through the transfer nip, and the fixing device 16 heat-fixes the toner image to the paper P. In the case of one-sided printing, the paper P is discharged to the paper discharge tray 4.

In the case of double-sided printing, the paper P is switched back at the downstream end of the first conveyance path 5 and sent to the second conveyance path 6, and then conveyed by a pair of conveyance rollers 42 and returned to the first conveyance path 5. be returned. Thereafter, an image is formed on the back side of the paper P through the same steps as described above, and the paper P with double-sided printing is discharged to the paper discharge tray 4.

[Image reading device]
The image reading device 1B includes a reading section 20 and a document conveying device 21. The reading unit 20 is attached to the upper surface of the apparatus main body 2 and is arranged above the paper discharge tray 4 with the paper discharge space in between. The document conveyance device 21 is attached to the upper surface of the reading section 20.

<Reading section>
The reading section 20 includes an optical scanning unit 22, a reflection unit 23, and an image sensor 24. The optical scanning unit 22 irradiates light onto a document placed on a contact glass 25A or a platen glass 25B. The reflection unit 23 reflects the light reflected by the original toward the image sensor 24. When reading the original on the platen glass 25B, the optical scanning unit 22 and the reflection unit 23 move so that the optical path length from the original to the image sensor 24 is constant. The image sensor 24 photoelectrically converts the input light.

<Original transport device>
The document conveyance device 21 includes a document holding section 26 , a supply tray 27 , an ejection tray 28 , and a conveyance section 29 . In the description of the image reading device 1B, the direction in which the document is transported is referred to as the "conveyance direction", and "upstream", "downstream", and similar terms are used to refer to "upstream", "downstream", and "downstream" in the conveyance direction. It refers to concepts similar to these.

The original holding unit 26 is rotatably (openable and closable) attached to the upper rear part of the reading unit 20 via a hinge (not shown). The supply tray 27 extends diagonally upward to the right from the conveyance section 29, and the discharge tray 28 is provided on the upper surface of the document holding section 26. The supply tray 27 is located upwardly apart from the discharge tray 28.

A document transport path 30 is formed inside the transport section 29 and is curved in a substantially U-shape so as to connect the supply tray 27 to the discharge tray 28 . At the upstream end of the document conveyance path 30 , a document feeding section 31 is provided that separates the documents stacked on the supply tray 27 one by one and feeds them out onto the document conveyance path 30 . A plurality of pairs of document conveyance rollers 32 are provided at the intermediate portion of the document conveyance path 30 (between the document feeding section 31 and the contact glass 25A), and a pair of document discharge rollers 33 is provided at the downstream end of the document conveyance path 30. It is being

[Image reading processing]
The operation of the image reading device 1B will be explained. When a document is set on the supply tray 27 with the document holding unit 26 closed, the control device executes the image reading process as follows. Note that although the originals stacked on the supply tray 27 are in the form of sheets, the originals stacked on the platen glass 25B are not limited to the sheets, and may be in the form of booklets, cards, or the like.

The document feeding unit 31 feeds the document set on the supply tray 27 to the document conveyance path 30 . The document is conveyed onto the contact glass 25A by a pair of document conveyance rollers 32. The optical scanning unit 22 irradiates light onto the document passing over the contact glass 25A, and the light reflected by the document is input to the image sensor 24 and converted into an electrical signal. As a result, the image of the document is read as image data. The document ejection roller pair 33 sends out the document that has passed through the contact glass 25A to the ejection tray 28.

Next, when the document holding unit 26 is opened and a document is set on the platen glass 25B, the control device executes the image reading process as described below. The optical scanning unit 22 irradiates the document on the platen glass 25B with light while moving rightward. The light reflected by the original is input to the image sensor 24 and converted into an electrical signal, thereby reading the image of the original as image data.

The image data read as described above is stored in the storage section of the control device, and the control device executes the image forming process (printing) described above. Note that the image data may be saved in an external terminal without being printed.

Incidentally, it is preferable that the multifunction device 1 is made smaller in consideration of installation in a limited space such as an office. For this reason, in the downsized image forming apparatus 1A, the transport paths 5 and 6 for transporting the paper P are often formed in a meandering manner (see FIG. 1). As a specific example, a curved path 6A is formed on the downstream side of the second conveyance path 6 (including the part where it merges with the first conveyance path 5), in which the paper P is conveyed while being curved. . The most downstream conveyance roller pair 42 among the plurality of conveyance roller pairs 42 described above is provided on the upstream side of the curved path 6A (or may be at the end of the straight portion of the second conveyance path 6), and the registration roller pair 43 is provided on the downstream side of the curved path 6A (or may be a straight portion of the first conveyance path 5). Note that the curved path 6A refers to the range in which the paper P is conveyed while being curved on the downstream side of the second conveyance path 6 (including a part of the first conveyance path 5) (for example, the range indicated by the two-dot chain line in FIG. 2). range). Further, the curved path 6A may be an arc-shaped path, a broken line path in which a plurality of straight paths are connected with fine bends, or a combination thereof. Any route that allows the (medium) to be conveyed while being curved may be used. Further, in the description of this specification, the transport roller pair 42 will be referred to as an upstream roller pair 42, and the registration roller pair 43 will be referred to as a downstream roller pair 43.

The upstream roller pair 42 and the downstream roller pair 43 transport (the paper P) by rotating while sandwiching the paper P (hereinafter also referred to as "nip transport"). Note that in each roller pair 42, 43, one roller is driven by a motor or the like, and the other roller is driven, but the invention is not limited to this, and both rollers may be driven. In addition, in the description of this specification, a state in which the paper P is nip-conveyed by the upstream roller pair 42 and is away from the downstream roller pair 43 (not nip-conveyed by the downstream roller pair 43) is referred to as a first state. This is called a transport state S1 (see FIG. 3). On the other hand, the state in which the paper P is nip-transported by the downstream roller pair 43 regardless of whether it is nip-transported by the upstream roller pair 42 is referred to as a second conveyance state S2 (FIGS. 4 and 5). reference).

In the first conveyance state S1, the paper P is conveyed while being curved along the radially outer surface (outer diameter surface 6B) of the curved path 6A by its own stiffness (see FIG. 3). Next, the first conveyance state S1 begins to change to the second conveyance state S2 (first half of the second conveyance state S2), that is, while the paper P continues to be nip conveyed by the upstream roller pair 42, the downstream roller pair 43 However, when the paper P starts to be conveyed in the nip, it receives the conveyance force from the downstream roller pair 43, is drawn radially inward from the outer diameter surface 6B of the curved path 6A, and is drawn along the inner diameter surface 6C of the curved path 6A. It begins to be transported (see Figure 4). Conveyance of the paper P further progresses, and the trailing edge of the paper P passes through the upstream roller pair 42 (nip conveyance by the upstream roller pair 42 is completed), and reaches a state where the paper P is nip conveyed by the downstream roller pair 43 (nip conveyance by the downstream roller pair 43 is completed). 2 in the latter half of the transport state S2), the stiffness (restoring force) of the paper P curved along the inner diameter surface 6C causes the rear end of the paper P to spring up from the inside to the outside in the radial direction of the curved path 6A (see FIG. 5). ). Then, the rear end of the paper P hits the outer diameter surface 6B of the curved path 6A, and a collision sound is generated.

In the first conveyance state S1, it is preferable that the upstream side of the curved path 6A is a wide path, and that the paper P is pressed from the inside in the radial direction on the downstream side of the curved path 6A. This makes it possible to ensure smooth conveyance of the paper P without hindering the conveyance of the paper P along the outer diameter surface 6B of the curved path 6A. On the other hand, in the second conveyance state S2, it is preferable that the downstream side of the curved path 6A is a wide path, and that the paper P is pressed from the outside in the radial direction on the upstream side of the curved path 6A. This makes it possible to suppress the occurrence of collision noise caused by the rear end of the paper P jumping up. Therefore, the image forming apparatus 1A is provided with a medium guide device 35 that suppresses the collision noise caused by the rear end of the paper P bouncing up while ensuring smooth conveyance of the paper P in the curved path 6A.

[Media guide device]
The medium guide device 35 according to the first embodiment will be described with reference to FIGS. 2 and 3. FIG. 2 is a front view showing the medium guide device 35. As shown in FIG. FIG. 3 is a front view showing the medium guide device 35 (first conveyance state S1).

As shown in FIG. 2, the medium guide device 35 includes an upstream roller pair 42, a downstream roller pair 43, a first rib 44, a second rib 45, and an interlocking part 46.

<Upstream roller pair, downstream roller pair>
As shown in FIG. 2, the upstream roller pair 42 (conveyance roller pair 42) is provided upstream of the apex portion 6T of the curved path 6A in the second conveyance path 6. The downstream roller pair 43 (registration roller pair 43) is provided downstream of the apex portion 6T in the second conveyance path 6. Specifically, the upstream roller pair 42 is provided slightly downstream from the upstream end of the curved path 6A, and the downstream roller pair 43 is provided at the downstream end of the curved path 6A (or the first conveyance path 5). (straight section). In addition, the apex portion 6T of the curved path 6A refers to the portion that protrudes most to the left in FIG. 2, but it does not strictly refer to only one point, but refers to a portion that includes a certain range. ing.

<First rib, second rib>
The first rib 44 is arranged between the upstream roller pair 42 and the apex portion 6T, and the second rib 45 is arranged between the apex portion 6T and the downstream roller pair 43. The first rib 44 is provided on the downstream side of the upstream roller pair 42 and on the upstream side of the apex portion 6T so as to be able to move into and out of the curved path 6A from the outside in the radial direction of the curved path 6A. The second rib 45 is provided on the upstream side of the downstream roller pair 43 and on the downstream side of the apex portion 6T so as to be able to protrude and retract into the curved path 6A from the inside of the curved path 6A in the radial direction. The first rib 44 and the second rib 45 are each formed in a substantially cylindrical shape (substantially disk shape), and contact (or are provided so as to be able to contact) the paper P while protruding into the curved path 6A. Although details will be described later, the first rib 44 and the second rib 45 are provided so as to be in contact with the paper P and rotatable around the axis. Needless to say, openings are formed in the outer diameter surface 6B and the inner diameter surface 6C of the curved path 6A for allowing the first rib 44 and the second rib 45 to emerge and retract.

<Interlocking part>
The interlocking section 46 is provided at the rear (or front) of the apparatus main body 2 (curved path 6A) so as not to obstruct conveyance of the paper P. The interlocking portion 46 has a function of interlocking the first rib 44 and the second rib 45 to move them into and out of the curved path 6A. Specifically, as shown in FIG. 3, the interlocking section 46 is a so-called link mechanism, and includes a first link section 51, a second link section 52, and a biasing member 53.

(1st link part)
The first link portion 51 is formed, for example, in an L-shape (or T-shape) from a metal plate, and is attached to the first rib 44 . The first rib 44 is supported at one end of the first link portion 51 so as to be rotatable around an axis. A first shaft 51A is provided at the bent portion of the first link portion 51, and the first link portion 51 is supported by the device main body 2 (or the member forming the curved path 6A) via the first shaft 51A. The first link portion 51 is rotatably provided around the first shaft 51A. A substantially cylindrical interlocking convex portion 51B is provided on the other end side of the first link portion 51 in a protruding manner.

(Second link)
The second link portion 52 is formed, for example, in an I-shape from a metal plate, and is attached to the second rib 45 . The second rib 45 is supported at one end of the second link portion 52 so as to be rotatable around the axis. A second shaft 52A is provided at one end of the second link portion 52, and the second link portion 52 is supported by the device main body 2 (or the member forming the curved path 6A) via the second shaft 52A. The second link portion 52 is rotatably provided around the second shaft 52A. A diagonally extending interlocking groove 52B is bored from the middle to the other end of the second link part 52. The interlocking convex portion 51B of the first link portion 51 is slidably inserted into the interlocking groove portion 52B. The second link portion 52 is rotatably and slidably connected to the first link portion 51 by inserting the interlocking convex portion 51B into the interlocking groove portion 52B.

(biasing member)
The biasing member 53 is a so-called tension coil spring, and is installed between the other end of the second link portion 52 and the device main body 2. The biasing member 53 biases (pulls) the other end of the second link portion 52 inward in the radial direction. In other words, the biasing member 53 indirectly biases the second rib 45 through the second link portion 52 in the direction of protruding into the curved path 6A. Note that the biasing member 53 may be considered to indirectly bias the first rib 44 in a direction to retreat from the curved path 6A via the first link portion 51 engaged with the second link portion 52. good.

[Function of medium guide device]
Next, the operation of the medium guide device 35, that is, the operation of the first rib 44 and the second rib 45 will be described with reference to FIGS. 3 to 5. FIG. 4 is a front view showing the medium guide device 35 (second transport state S2 (first half)). FIG. 5 is a front view showing the medium guide device 35 (second conveyance state S2 (later stage)).

<First transport state>
First, a first conveyance state S1 in which the paper P is nip-conveyed by the upstream roller pair 42 but not nip-conveyed by the downstream roller pair 43 will be described. As shown in FIG. 3, in the first conveyance state S1, the interlocking unit 46 retracts the first rib 44 from the curved path 6A and causes the second rib 45 to protrude into the curved path 6A. Specifically, the biasing force of the biasing member 53 is applied to the first link portion 51 and the second link portion 52 so as to retract the first rib 44 from the curved path 6A and cause the second rib 45 to protrude into the curved path 6A. and rotate. At this time, the interlocking convex portion 51B of the first link portion 51 abuts the other end (on the opposite side to the second rib 45) of the interlocking groove portion 52B of the second link portion 52. Note that the first rib 44 retracting from the curved path 6A does not require that the first rib 44 completely retract from the curved path 6A, but may only slightly protrude from the outer diameter surface 6B of the curved path 6A. It means permissive. Moreover, the second rib 45 protruding into the curved path 6A means a state in which it does not obstruct the conveyance of the paper P, lightly contacts the paper P, and causes the paper P to follow the outer diameter surface 6B of the curved path 6A. Further, even when the paper P is not being transported (a state in which the image forming process is not executed and is stopped), the first transporting state S1 is maintained.

Since the first rib 44 is retracted from the curved path 6A, a wide distance is ensured between the inner diameter surface 6C and the outer diameter surface 6B on the upstream side of the curved route 6A. Thereby, the paper P can smoothly enter the curved path 6A. The paper P that has entered the curved path 6A is pressed against the outer diameter surface 6B of the curved route 6A, and is conveyed while being curved along (in contact with) the outer diameter surface 6B. Since the second rib 45 protrudes into the curved path 6A, it comes into contact with (or is allowed to come into contact with (does not always need to come into contact with)) the inner surface of the paper P that is conveyed along the outer diameter surface 6B. Thereby, the paper P conveyed along the outer diameter surface 6B of the curved path 6A can be guided. Note that when the second rib 45 comes into contact with the paper P, it guides the paper P while rotating around the axis.

<Second feeding state>
Next, a second conveyance state S2 in which the paper P is nip conveyed by the pair of downstream rollers 43 will be described. As shown in FIG. 4, in the second conveyance state S2, the interlocking section 46 causes the first rib 44 to protrude into the curved path 6A, and retracts the second rib 45 from the curved path 6A. To explain in detail, in the first half of the second conveyance state S2, when the paper P continues to be nip-conveyed by the upstream roller pair 42 and starts to be nip-conveyed by the downstream roller pair 43, the outer diameter surface of the curved path 6A 6B, it is drawn inward in the radial direction and begins to be conveyed along the inner diameter surface 6C. Then, the second rib 45 is pressed by the paper P being conveyed as shown by the white arrow in FIG. 4, and rotates the second link part 52 (clockwise in FIG. It retreats from the curved path 6A against the urging force. As the second link part 52 rotates around the second shaft 52A, the first link part 51 moves the interlocking convex part 51B to the second rib 45 side along the interlocking groove part 52B of the second link part 52. While sliding, it rotates around the first shaft 51A (counterclockwise in FIG. 4). That is, the first link part 51 rotates in conjunction with the second link part 52 so that the first rib 44 projects into the curved path 6A while sliding relative to the second link part 52. At this time, the interlocking convex portion 51B of the first link portion 51 abuts one end (on the second rib 45 side) of the interlocking groove portion 52B of the second link portion 52.

Note that the retraction of the second rib 45 from the curved path 6A does not mean that the second rib 45 must be completely retracted from the curved path 6A, but it is permissible for the second rib 45 to slightly protrude from the inner diameter surface 6C of the curved path 6A. It means to do. Moreover, the first rib 44 protruding into the curved path 6A means a state in which it does not obstruct the conveyance of the paper P, lightly contacts the paper P, and causes the paper P to follow the inner diameter surface 6C of the curved path 6A.

In the first half of the second conveyance state S2, the second rib 45 is retracted from the curved path 6A, so that a wide gap is ensured between the inner diameter surface 6C and the outer diameter surface 6B on the downstream side of the curved route 6A. Thereby, smooth conveyance of the paper P along (in contact with) the inner diameter surface 6C of the curved path 6A can be ensured. Further, since the first rib 44 protrudes into the curved path 6A, it contacts (or is capable of contacting (does not always need to contact)) the outer surface of the paper P that is conveyed along the inner diameter surface 6C. . Thereby, the paper P conveyed along the inner diameter surface 6C of the curved path 6A can be guided. Note that when the first rib 44 comes into contact with the paper P, it guides the paper P while rotating around the axis.

As shown in FIG. 5, when the rear end of the paper P passes through the upstream roller pair 42 and enters the latter half of the second conveyance state S2, the stiffness (restoring force) of the paper P curved along the inner diameter surface 6C causes The trailing end of the paper P tries to jump radially outward of the curved path 6A (see the arrow indicated by the broken line in FIG. 5). However, as described above, since the first rib 44 protrudes into the curved path 6A, the rear side of the paper P contacts the first rib 44 and is prevented from jumping up.

When the paper P is conveyed and the push of the second rib 45 by the paper P is released, the second link portion 52 is biased by the biasing member 53 to cause the second rib 45 to protrude into the curved path 6A. (counterclockwise in Figure 3). The first link portion 51 rotates (clockwise in FIG. 3) in conjunction with the second link portion 52 so as to retract the first rib 44 from the curved path 6A.

In the medium guide device 35 according to the first embodiment described above, in the first conveyance state S1, the interlocking unit 46 retracts the first rib 44 from the curved path 6A and moves the second rib 45 to the curved path 6A. The structure is such that it protrudes (see Fig. 3). According to this configuration, the first rib 44 does not become an obstacle to the paper P (medium) being conveyed along the outer diameter surface 6B of the curved path 6A. Further, the second rib 45 contacts the paper P from the inside in the radial direction, so that the paper P conveyed along the outer diameter surface 6B of the curved path 6A can be guided. In addition, in the medium guide device 35, when in the second conveyance state S2, the interlocking section 46 is configured to cause the first rib 44 to protrude into the curved path 6A and to retract the second rib 45 from the curved path 6A (Fig. 4 and Figure 5). According to this configuration, the first rib 44 contacts the paper P from the outside in the radial direction, so that the rear side of the paper P that has passed the upstream roller pair 42 can be held down so that it does not jump up. Further, the second rib 45 does not become an obstacle to the paper P being conveyed along the inner diameter surface 6C of the curved path 6A. Thereby, it is possible to suppress the occurrence of collision noise caused by the rear end of the paper P bouncing up while ensuring smooth conveyance of the paper P in the curved path 6A.

Further, in the medium guide device 35 according to the first embodiment, the interlocking section 46 includes a link mechanism, and the paper P is nip-conveyed by the downstream roller pair 43 and drawn from the outer diameter surface 6B to the inner diameter surface 6C of the curved path 6A. The link mechanism is configured to operate using the force exerted by the link mechanism. According to this configuration, without using a power source such as a motor, the first rib 44 and the second rib 45 can be operated in conjunction with each other so that the protruding and retracting states are opposite to each other. Further, a sensor for detecting the actuation timing of the two ribs 44, 45, a power source, a controller for controlling the sensor, etc. are also unnecessary. Thereby, manufacturing costs and running costs such as power consumption of the medium guide device 35 can be reduced.

Further, according to the medium guide device 35 according to the first embodiment, each rib 44, 45 rotates while contacting the paper P, so that the conveyance of the paper P is not obstructed and smooth conveyance of the paper P is achieved. Can be guaranteed.

Note that in the medium guide device 35 according to the first embodiment, the biasing member 53 is a tension coil spring that pulls the second link portion 52, but by changing the arrangement, a compression coil spring that pushes the second link portion 52 is adopted. (not shown). Moreover, the biasing member 53 may be provided instead of the second link part 52 so as to pull or push the first link part 51 (not shown). Further, the biasing member 53 is not limited to a coil spring, and may be an elastic body such as a plate spring or rubber (not shown).

Further, in the medium guide device 35 according to the first embodiment, the biasing member 53 indirectly biases the second rib 45 via the second link portion 52, but the present invention is not limited to this. For example, when the first rib 44 (or the second rib 45) is provided in a non-rotatable manner, the biasing member 53 is connected to the first rib 44 (or the second rib 45) and the biasing member 53 is connected to the first rib 44 (or the second rib 45). 2 ribs 45) may be directly biased (not shown).

Further, in the medium guide device 35 according to the first embodiment, the first link portion 51 is provided with the interlocking convex portion 51B, and the second link portion 52 is provided with the interlocking groove portion 52B, but the present invention is not limited to this. The first link portion 51 may be provided with an interlocking groove portion 52B, and the second link portion 52 may be provided with an interlocking convex portion 51B (not shown).

Further, in the medium guide device 35 according to the first embodiment, the interlocking portion 46 has a structure in which the first rib 44 and the second rib 45 are moved in and out in conjunction with each other without using any other power source. The invention is not limited to this. For example, the biasing member 53 may be omitted and the interlocking section 46 may include a driving section (not shown) such as a solenoid (a modification of the first embodiment). In this case, for example, the tip of the plunger of the solenoid is rotatably connected to the first link part 51 or the second link part 52, and the solenoid is driven and controlled by the control device to reciprocate the plunger. The respective link portions 51 and 52 may be swung to cause the respective ribs 44 and 45 to appear and retract (not shown). Further, the interlocking unit 46 includes a detection unit such as a reflection type or transmission type optical sensor, and activates a drive unit such as a solenoid at the timing when the detection unit detects the paper P that has passed through the downstream roller pair 43. It is better to control the drive.

[Other embodiments]
Other embodiments will be described below with reference to FIGS. 6 to 9. FIG. 6 is a front view showing the medium guide device 36 (first conveyance state S1) according to the second embodiment. FIG. 7 is a front view showing the medium guide device 36 (second transport state S2) according to the second embodiment. FIG. 8 is a front view showing the medium guide device 37 (first conveyance state S1) according to the third embodiment. FIG. 9 is a front view showing the medium guide device 37 (second transport state S2) according to the third embodiment. In the following description (including modifications), the same reference numerals are given to the same or corresponding configurations as those of the medium guide device 35 according to the first embodiment described above, and the description thereof will be omitted.

[Second embodiment]
As shown in FIG. 6, in the medium guide device 36 according to the second embodiment, the interlocking section 47 includes a driving section 61, a detecting section 62, and a biasing member 63 instead of the link mechanism. There is.

(Drive part)
The drive unit 61 is, for example, a servo motor that can control the rotation angle of the drive shaft 61A. The drive unit 61 is electrically connected to the control device of the multifunction device 1 and controlled by the control device. An arm portion 61B is attached to the drive shaft 61A of the drive portion 61, and the first rib 44 is rotatably supported at the tip of the arm portion 61B. The drive unit 61 moves the first rib 44 into and out of the curved path 6A by swinging the arm unit 61B (drive shaft 61A).

(Detection part)
The detection section 62 is, for example, a transmission type optical sensor in which a light emitting section and a light receiving section are arranged facing each other, and is provided near the second rib 45 . The detection unit 62 is electrically connected to the control device of the multifunction device 1 and transmits a detection signal to the control device. The above-mentioned second rib 45 is rotatably supported by the support part 64, and the support part 64 is slidably supported by the device main body 2 so that the second rib 45 appears and disappears in the curved path 6A. When the second rib 45 retreats from the curved path 6A, the light shielding piece 64A formed on the support part 64 enters between the light emitting part and the light receiving part and blocks the light emitted from the light emitting part (see FIG. 7). Thereby, the detection unit 62 detects the second rib 45 that has retreated from the curved path 6A.

(biasing member)
The biasing member 63 is, for example, a compression coil spring, and is provided so as to wrap around the support portion 64 . One end of the biasing member 63 is in contact with the flange portion 64B of the support portion 64, and the other end of the biasing member 63 is in contact with the device main body 2. The biasing member 63 biases the second rib 45 via the support portion 64 so as to protrude into the curved path 6A.

Note that although the control device is a component of the multifunction peripheral 1, it may also be considered as a component of the medium guide device 36 or the drive section 61. Further, a dedicated control device for the medium guide device 36 (drive section 61) may be provided separately from the control device of the multifunction device 1, and the drive section 61 and the detection section 62 may be controlled by the dedicated control device (not shown). ).

[Function of medium guide device]
Next, the operation of the medium guide device 36 (interlocking section 47) will be briefly explained.

As shown in FIG. 6, in the first conveyance state S1, the drive unit 61 moves the first rib 44 away from the curved path 6A, and the second rib 45 is urged by the urging member 63 to move toward the curved path 6A. It stands out. Specifically, the detection unit 62 transmits a detection signal indicating that the second rib 45 (light shielding piece 64A) that has retreated from the curved path 6A is not detected to the control device, and the control device transmits the detection signal from the detection unit 62 to the control device. In response to the detection signal (detection result), the drive unit 61 is rotationally controlled to retract the first rib 44 from the curved path 6A (or maintain the retracted state).

As shown in FIG. 7, in the second conveyance state S2, the second rib 45 is pressed by the conveyed paper P and retreats from the curved path 6A against the biasing force of the biasing member 63, and the detection unit Based on the detection of the second rib 45 (light shielding piece 64A) from which the second rib 62 has retreated, the drive unit 61 causes the first rib 44 to protrude into the curved path 6A. Specifically, the detection unit 62 transmits a detection signal indicating that the second rib 45 retracted from the curved path 6A has been detected to the control device, and the control device receives the detection signal (detection result) from the detection unit 62. In response, the drive unit 61 is rotationally controlled to cause the first rib 44 to protrude into the curved path 6A (or to maintain the protruded state).

As the sheet P continues to be conveyed and the second rib 45 is no longer pushed by the sheet P, the second rib 45 is urged by the urging member 63 and protrudes into the curved path 6A (see FIG. 6). Since the detection unit 62 no longer detects the second rib 45, the control device rotationally controls the drive unit 61 to retreat the first rib 44 from the curved path 6A (see FIG. 6).

In the medium guide device 36 according to the second embodiment described above, in the first conveyance state S1, the drive unit 61 retracts the first rib 44, the second rib 45 is urged by the urging member 63 and protrudes, In the second conveyance state S2, the drive unit 61 causes the first rib 44 to protrude, and the second rib 45 is pushed by the paper P and retracted. According to this configuration, the medium guide device according to the first embodiment can suppress the occurrence of collision noise caused by the rear end of the paper P bouncing up while ensuring smooth conveyance of the paper P in the curved path 6A. The same effect as 35 can be obtained. Further, according to the medium guide device 36 according to the second embodiment, the first rib 44 is configured to protrude and retract in response to the driving force of the drive unit 61, in addition to the protruding and retracting operation of the second rib 45, so that, for example, To make the first rib 44 protrude earlier (or later), or to adjust the protrusion amount (including not protruding it) of the first rib 44 according to the thickness (firmness) and type of paper P. You can also do it.

Note that in the medium guide device 36 (interlocking unit 47) according to the second embodiment, the drive unit 61 is a servo motor, but is not limited to this, and may be a solenoid that can reciprocate the plunger, for example. Good (not shown). Further, the detection unit 62 is not limited to a transmission type optical sensor, but may be a reflection type optical sensor that detects light reflected by the light shielding piece 64A, or a micro switch pressed by the support unit 64, etc. (not shown). Further, the biasing member 63 is not limited to a coil spring, and may be an elastic body such as a plate spring or rubber (not shown).

[Third embodiment]
As shown in FIG. 8, in the medium guide device 37 according to the third embodiment, the interlocking section 48 includes a first drive section 71, a second drive section 72, and a detection section 73.

(First drive section, second drive section)
The first drive section 71 (first drive shaft 71A, first arm section 71B) and the second drive section 72 (second drive shaft 72A, second arm section 72B) are respectively the medium guide device according to the second embodiment. The first drive section 71 has the same structure as the drive section 61 (drive shaft 61A, arm section 61B) of No. 36, and the first drive section 71 makes the first rib 44 appear and disappear in the curved path 6A, and the second drive section 72 moves the second rib 45. It appears on the curved path 6A.

(Detection part)
The detection unit 73 is, for example, a reflective optical sensor in which a light emitting unit and a light receiving unit are arranged side by side, and is provided near the downstream side of the downstream roller pair 43. The detection unit 73 is electrically connected to the control device of the multifunction device 1 and transmits a detection signal to the control device. When the leading edge of the paper P passes the pair of downstream rollers 43, the light emitted from the light emitting section is reflected by the paper P and enters the light receiving section. Thereby, the detection unit 73 detects that the downstream roller pair 43 is conveying the paper P.

[Function of medium guide device]
Next, the operation of the medium guide device 37 (interlocking section 48) will be briefly explained.

As shown in FIG. 8, in the first conveyance state S1, the first drive section 71 retracts the first rib 44 from the curved path 6A, and the second drive section 72 moves the second rib 45 to the curved path 6A. let Specifically, the detection unit 73 transmits a detection signal indicating that the paper P is not detected to the control device, and the control device receives the detection signal (detection result) from the detection unit 73 and starts the first drive. The portion 71 is rotationally controlled to retract the first rib 44 from the curved path 6A, and the second drive portion 72 is rotationally controlled to cause the second rib 45 to protrude into the curved path 6A (or to cause the second rib 45 to protrude into the curved path 6A). Hold.)

As shown in FIG. 9, in the second transport state S2, the first drive unit 71 bends the first rib 44 based on the detection unit 73 detecting the transport of the paper P by the downstream roller pair 43. The second driving section 72 causes the second rib 45 to protrude into the curved path 6A, and then retracts the second rib 45 from the curved path 6A. Specifically, the detection unit 73 transmits a detection signal indicating that the paper P has been detected to the control device, and the control device receives the detection signal (detection result) from the detection unit 73 and controls the first drive unit 71. is rotationally controlled to cause the first rib 44 to protrude into the curved path 6A, and the second drive unit 72 is rotationally controlled to retract the second rib 45 from the curved path 6A (or to maintain the retracted/protruded state). .)

When the conveyance of the paper P progresses and the detection unit 73 no longer detects the paper P, the control device rotationally controls the first drive unit 71 to retract the first rib 44 from the curved path 6A, and the second drive unit 72 is rotationally controlled to cause the second rib 45 to protrude into the curved path 6A (see FIG. 8).

According to the medium guide device 37 according to the third embodiment described above, it is possible to suppress the occurrence of collision noise caused by the rear end of the paper P bouncing up while ensuring smooth conveyance of the paper P in the curved path 6A. The same effects as those of the medium guiding devices 35 and 36 according to the first and second embodiments can be obtained.

Note that in the medium guide device 37 (interlocking unit 48) according to the third embodiment, the first drive unit 71 and the second drive unit 72 are servo motors, but the invention is not limited to this. It may also be a movable solenoid (not shown). Further, the detection unit 73 is not limited to a reflective optical sensor, but may be a transmissive optical sensor, for example, or an electrostatic sensor that detects the capacitance that changes when the paper P is sandwiched between the downstream roller pair 43. It may be a capacitance sensor or a camera that photographs the paper P (not shown). Furthermore, the detection section 73 of the medium guide device 37 according to the third embodiment may be employed as the detection section 62 of the medium guide device 36 according to the second embodiment (not shown).

Note that although the medium guide devices 35 to 37 according to the first to third embodiments are provided in the curved path 6A on the downstream side of the second conveyance path 6, the present invention is not limited thereto. For example, the medium guide devices 35 to 37 may be provided in a substantially U-shaped curved portion (see FIG. 1) on the upstream side of the first conveyance path 5 (near the paper feed cassette 3). In this case, the paper feed roller pair 40 becomes an upstream roller pair, and the transport roller pair 41 becomes a downstream roller pair. In this way, the medium guide devices 35 to 37 can be applied to any route that allows the medium such as the paper P to be conveyed while being curved.

[First modification]
Although the medium guide devices 35 to 37 according to the first to third embodiments are provided in the image forming apparatus 1A, the present invention is not limited thereto. For example, as shown in FIG. 10, the medium guide devices 35 to 37 may be provided in the document transport path 30 curved in a substantially U-shape of the image reading device 1B (first modification). In this case, the document transport roller pair 32 disposed upstream of the curved portion becomes an upstream roller pair, and the document transport roller pair 32 disposed downstream of the curved portion becomes a downstream roller pair.

[Second modification]
As shown in FIG. 11, the multifunction device 1 may be equipped with a post-processing device 7 that aligns a plurality of sheets P, and staples and bundles a plurality of sheets P that are arranged. A post-processing conveyance path 8 is provided inside the post-processing device 7, which is continuous from the first conveyance path 5 of the image forming apparatus 1A. The medium guide devices 35 to 37 according to the first to third embodiments may be provided in the post-processing conveyance path 8 of the post-processing device 7, which is curved in a substantially U-shape (second modification). In this case, the pair of post-processing rollers 74 arranged on the upstream side of the curved portion becomes the upstream roller pair, and the post-processing roller pair 74 arranged on the downstream side of the curved portion becomes the downstream roller pair.

Note that in the medium guide devices 35 to 37 according to the first to third embodiments (including each modification example; the same applies hereinafter), the first rib 44 and the second rib 45 are formed in a substantially cylindrical shape, and the axial center Although it is possible to rotate around the circumference, the present invention is not limited thereto. For example, at least one of the first rib 44 and the second rib 45 may be formed into a semicircular shape or a trapezoidal shape, or may be provided non-rotatably (not shown). Further, although one first rib 44 and one second rib 45 were provided, the present invention is not limited to this, and for example, a plurality of first ribs 44 (a plurality of second ribs 45) may extend in the front-rear direction. They may also be spaced apart on the shaft (not shown).

Furthermore, although the image forming apparatus 1A described above is a monochrome printer, it is not limited thereto, and may be a color printer, a copier, a facsimile, or the like. Further, although the image forming method of the image forming apparatus 1A is an electrophotographic method, it is not limited thereto, and may be an inkjet method.

Note that the description of the above embodiments shows one aspect of the medium guiding device, image forming device, image reading device, and post-processing device according to the present invention, and the technical scope of the present invention is limited to the above embodiments. It is not something that will be done. The present invention may be variously changed, replaced, and modified without departing from the spirit of the technical idea, and the scope of the claims includes all embodiments that can be included within the scope of the technical idea.

1 Multifunction device 1A Image forming device 1B Image reading device 5 First conveyance path (conveyance path)
6 Second conveyance path (conveyance path)
6A Curved path 6T Vertex portion 7 Post-processing device 8 Post-processing conveyance path (conveyance path)
30 Document conveyance path (conveyance path)
32 Original transport roller pair 35, 36, 37 Medium guide device 42 Upstream roller pair 43 Downstream roller pair 44 First rib 45 Second rib 46, 47, 48 Interlocking part 51 First link part 51A First shaft 52 Second Link section 52A Second shaft 53, 63 Biasing member 61 Drive section 62, 73 Detection section 71 First drive section 72 Second drive section 74 Post-processing roller pair S1 First conveyance state S2 Second conveyance state

Claims (8)

A pair of upstream rollers that are provided upstream of the apex of the curved path in the conveyance direction of the medium in a conveyance path including a curved path in which the medium is conveyed while being curved, and convey the medium by rotating while sandwiching the medium; ,
a pair of downstream rollers that are provided on the conveyance path downstream of the apex in the conveyance direction and convey the medium by rotating while sandwiching the medium;
Provided so as to be able to appear and retract into the curved path from the outside in the radial direction of the curved path on the downstream side of the upstream roller pair in the conveyance direction and the upstream side of the apex in the conveyance direction, and protrude into the curved path. a first rib that contacts the medium in a state of
Provided so as to be able to appear in and out of the curved path from inside the curved path in the radial direction on the upstream side of the downstream roller pair in the conveyance direction and downstream of the apex in the conveyance direction, and protrude into the curved path. a second rib that contacts the medium in a state of
an interlocking part that interlocks the first rib and the second rib to move in and out of the curved path,
When the medium being conveyed while being sandwiched between the upstream roller pair is in a first conveying state in which it is separated from the downstream roller pair, the interlocking section retracts the first rib from the curved path and causing a second rib to protrude into the curved path;
When the medium is in a second conveyance state in which the medium is conveyed while being sandwiched between the pair of downstream rollers, the interlocking section causes the first rib to protrude into the curved path and retracts the second rib from the curved path. A medium guiding device characterized in that: The interlocking part is
a first link portion attached to the first rib and rotatably provided around a first axis;
a second link part attached to the second rib, rotatably provided around a second axis, and rotatably and slidably connected to the first link part;
a biasing member that directly or indirectly biases the first rib or the second rib;
In the first transport state, the biasing force of the biasing member is applied to the first link portion and the biasing member so as to retract the first rib from the curved path and cause the second rib to protrude into the curved path. Rotate the second link part,
In the second conveyance state, the second rib is pressed by the conveyed medium and moves away from the curved path against the biasing force of the biasing member while rotating the second link portion. 2. The medium guide according to claim 1, wherein the first link part rotates so as to cause the first rib to protrude into the curved path while sliding relative to the second link part. Device. The interlocking part is
a drive unit that causes the first rib to move in and out of the curved path;
a detection unit that detects the second rib that has retreated from the curved path;
a biasing member that biases the second rib to protrude into the curved path;
When in the first conveyance state, the drive unit retracts the first rib from the curved path, and the second rib is urged by the biasing member to protrude into the curved path,
In the second conveyance state, the second rib is pressed by the medium being conveyed and retreats from the curved path against the biasing force of the biasing member, and the detection unit retracts from the second The medium guiding device according to claim 1, wherein the driving unit causes the first rib to protrude into the curved path based on detecting the rib. The interlocking part is
a first drive unit that causes the first rib to move in and out of the curved path;
a second drive unit that causes the second rib to move in and out of the curved path;
a detection unit that detects that the downstream roller pair is transporting the medium;
When in the first conveyance state, the first driving section retracts the first rib from the curved path, and the second driving section causes the second rib to protrude into the curved path,
In the second transport state, based on the detection unit detecting transport of the medium by the downstream roller pair, the first drive unit causes the first rib to protrude into the curved path, The medium guiding device according to claim 1, wherein the second driving section retracts the second rib from the curved path. The medium guide device according to any one of claims 1 to 4, wherein the first rib and the second rib are provided so as to be rotatable around an axis in contact with the medium. . An image forming apparatus comprising the medium guiding device according to any one of claims 1 to 4. An image reading device comprising the medium guide device according to claim 1 . A post-processing device comprising the medium guide device according to any one of claims 1 to 4.

Images