Patent Application
20220242084
This application is based on and claims the benefit of priority from Japanese Patent Application No. 2021-016540 filed on Feb. 4, 2021, the contents of which are hereby incorporated by reference.
The present disclosure relates to a sheet post-processing apparatus that performs a folding process on, to make a fold in, a sheet having an image formed on it by an image forming apparatus.
Known sheet post-processing apparatuses include those which perform a folding process on, to make a fold in, a sheet that has an image formed on it by an image forming apparatus such as a copier or printer.
For example, a known sheet post-processing apparatus includes a first conveyance passage, a second conveyance passage, a communication passage that connect together the first and second conveyance passages, a second conveyance roller and a third conveyance roller that are arranged opposite each other in the communication passage, and the second and a fourth conveyance roller that are disposed opposite each other across the second conveyance passage. The second and third conveyance rollers constitute a first folding portion, and the second and fourth conveyance rollers constitute a second folding portion. This sheet post-processing apparatus can perform a folding process on a sheet with a short conveyance passage length and contributes to reducing the size of the apparatus.
According to one aspect of the present disclosure, a sheet post-processing apparatus includes: a sheet introduction port, a first sheet conveyance passage, a second sheet conveyance passage, a switch guide, a sheet folding portion, a folding conveyance passage, a merging portion, and a controller. Through the sheet introduction port, a sheet is introduced. The first sheet conveyance passage extends from the sheet introduction port, and along the first sheet conveyance passage, the sheet is conveyed. The second sheet conveyance passage extends so as to branch off from a branch portion on the first sheet conveyance passage. The switch guide pivots, in the branch portion, between a first position in which the switch guide guides the sheet conveyed from the sheet introduction port along the first sheet conveyance passage toward the downstream end of the first sheet conveyance passage in the sheet conveyance direction and a second position in which the switch guide guides the sheet conveyed from the sheet introduction port along the first sheet conveyance passage to the second sheet conveyance passage. The sheet folding portion is located upstream, in the sheet conveyance direction, of the branch portion on the first sheet conveyance passage, and performs a folding process on the sheet. Through the folding conveyance passage, the sheet is conveyed in the sheet folding portion. The merging portion is located downstream, in the sheet conveyance direction, of the branch portion on the first sheet conveyance passage, and at the merging portion, the folding conveyance passage merges with the first sheet conveyance passage. The controller controls the first sheet conveyance passage, the second sheet conveyance passage, the switch guide, and the sheet folding portion. When performing the folding process on the sheet in the sheet folding portion, the controller first guides the downstream end, in the sheet conveyance direction, of the sheet conveyed from the sheet introduction port into the first sheet conveyance passage via the branch portion to the second sheet conveyance passage, then reverses the conveyance direction of the sheet to guide the sheet to the sheet folding portion to perform the folding process on the sheet, and then passes the sheet subjected to the folding process through the folding conveyance passage, and merges the sheet into the first sheet conveyance passage at the merging portion.
An embodiment of the present disclosure will be described below with reference to the accompanying drawings. What is specifically disclosed herein is not meant to limit the scope of the present disclosure.
As shown in
The sheet introduction port 2 is provided so as to be open in the side face of the sheet post-processing apparatus 1 facing the image forming apparatus (not shown). A sheet conveyed from the image forming apparatus to the sheet post-processing apparatus 1 is conveyed from the sheet introduction port 2 into the sheet post-processing apparatus 1.
The first sheet conveyance passage 3 extends from the sheet introduction port 2 to the first sheet discharge portion 4 substantially horizontally in a direction away from the image forming apparatus (i.e., leftward in
The first sheet discharge portion 4 is provided in the side face of the sheet post-processing apparatus 1 opposite from its side face facing the image forming apparatus. The first sheet discharge portion 4 is disposed at the downstream end of the first sheet conveyance passage 3 in the sheet conveyance direction. The first sheet discharge portion 4 includes a first discharge port 41, a pair of first discharge rollers 42, and a first discharge tray 43.
The first discharge port 41 is located at the downstream end of the first sheet conveyance passage 3 in the sheet conveyance direction. The pair of first discharge rollers 42 is disposed in the first discharge port 41. The first discharge tray 43 is located downstream of the first discharge port 41 in the sheet conveyance direction. The sheet conveyed along the first sheet conveyance passage 3 to reach the first discharge port 41 is discharged through the first discharge port 41 onto the first discharge tray 43 by the pair of first discharge rollers 42. The first discharge tray 43 is one of the places where the sheet post-processed by the sheet post-processing apparatus 1 is eventually discharged.
The second sheet conveyance passage 5 branches off from a first branch portion (branch portion) 31 on the first sheet conveyance passage 3, and extends to the second sheet discharge portion 6 laterally, with an upward inclination, in a direction away from the image forming apparatus (i.e., leftward in
The first branch portion 31 includes a first switch guide 311. The first switch guide 311 can pivot between a first position (broken line P1 in
The second sheet discharge portion 6 is provided in the side face of the sheet post-processing apparatus 1 opposite from its side face facing the image forming apparatus, over the first sheet discharge portion 4. The second sheet discharge portion 6 is disposed at the downstream end of the second sheet conveyance passage 5 in the sheet conveyance direction. The second sheet discharge portion 6 includes a second discharge port 61, a second pair of discharge rollers 62, and a second discharge tray 63.
The second discharge port 61 is located at the downstream end of the second sheet conveyance passage 5 in the sheet conveyance direction. The second pair of discharge rollers 62 is disposed in the second discharge port 61. The second discharge tray 63 is located downstream of the second discharge port 61 in the sheet conveyance direction. The sheet conveyed along the second sheet conveyance passage 5 to reach the second discharge port 61 is discharged through the second discharge port 61 onto the second discharge tray 63 by the second pair of discharge rollers 62. The second discharge tray 63 is one of the places where the sheet post-processed by the sheet post-processing apparatus 1 is eventually discharged. Also discharged onto the second discharge tray 63 are sheets that are not subjected to post-processing and sheets of small sizes.
The third sheet conveyance passage 7 branches off from a second branch portion 32 on the first sheet conveyance passage 3, and extends downward to the third sheet discharge portion 8. In the present description, the direction pointing from the second branch portion 32 to the third sheet discharge portion 8 is referred to as the sheet conveyance direction along the third sheet conveyance passage 7. The second branch portion 32 is located downstream, in the sheet conveyance direction, of the first branch portion 31 on the first sheet conveyance passage 3, and is located at the upstream end of the third sheet conveyance passage 7 in the sheet conveyance direction. The third sheet conveyance passage 7 has a plurality of pairs of conveyance rollers 7r, and conveys the sheet having left the first sheet conveyance passage 3 at the second branch portion 32 downstream in the sheet conveyance direction.
The second branch portion 32 includes a second switch guide 321. The second switch guide 321 pivots between a first position in which the second switch guide 321 guides the sheet conveyed from the sheet introduction port 2 along the first sheet conveyance passage 3 toward the first discharge port 41 and a second position in which the second switch guide 321 guides the sheet conveyed from the sheet introduction port 2 along the first sheet conveyance passage 3 and then forwarded to the second branch portion 32 to be switched back toward the third sheet conveyance passage 7. The second switch guide 321 is connected to a drive mechanism (not shown), and its operation is controlled by the post-processing controller 10.
The third sheet discharge portion 8 is provided in the side face of the sheet post-processing apparatus 1 opposite from its side face facing the image forming apparatus, under the first sheet discharge portion 4. In other words, the third sheet discharge portion 8 is disposed near a bottom part of the sheet post-processing apparatus 1. The third sheet discharge portion 8 includes a third discharge port 81, a pair of third discharge rollers 82, and a third discharge tray 83.
The third discharge port 81 is located at the downstream end of the third sheet conveyance passage 7 in the sheet conveyance direction. The pair of third discharge rollers 82 is disposed in the third discharge port 81. The third discharge tray 83 is located downstream of the third discharge port 81 in the sheet conveyance direction. The sheet conveyed along the third sheet conveyance passage 7 to reach the third discharge port 81 is discharged via the third discharge port 81 onto the third discharge tray 83 by the pair of third discharge rollers 82. The third discharge tray 83 is one of the places where the sheet post-processed by the sheet post-processing apparatus 1 is eventually discharged.
The post-processing portion 9 performs predetermined post-processing on the sheet having undergone image formation by the image forming apparatus and introduced into the sheet post-processing apparatus 1. The post-processing portion 9 includes a punching portion 91, a stapling portion 92, a sheet folding portion 100, and a book-binding portion 94.
The punching portion 91 is disposed in the first sheet conveyance passage 3, closely downstream of the sheet introduction port 2. The punching portion 91 can performs a punching process on the sheet conveyed along the first sheet conveyance passage 3, thereby to form punch holes in it.
The stapling portion 92 is disposed in a downstream part of the first sheet conveyance passage 3 in the sheet conveyance direction, near the first sheet discharge portion 4. The stapling portion 92 can perform a stapling process (binding process) on a bundle of sheets formed by stacking together a plurality of sheets, thereby to bind the bundle of sheets.
The sheet folding portion 100 is disposed in the first sheet conveyance passage 3, downstream of the punching portion 91, upstream of the stapling portion 92. In other words, the sheet folding portion 100 is located upstream, in the sheet conveyance direction, of the first branch portion 31 on the first sheet conveyance passage 3. The sheet folding portion 100 can perform a folding process on a single sheet, thereby to make a fold in it.
The sheet folding portion 100 can perform folding processes such as double-folding, Z folding, outward triple folding, inward triple folding, and quadruple-folding.
Z folding is a manner of folding in which, for example as shown in
Outward triple folding is a manner folding in which, for example as shown in
In inward triple folding, for example as shown in
The construction of the sheet folding portion 100 will be described in detail later.
The book-binding portion 94 is disposed in a downstream part of the third sheet conveyance passage 7 in the sheet conveyance direction, near the third sheet discharge portion 8. The book-binding portion 94 includes a middle-folding portion 941 and a middle-binding portion 942. The book-binding portion 94 performs, on a bundle of sheets formed by stacking together a plurality of sheets, a middle-folding process and a middle-binding process in which it folds and staples the bundle of sheets substantially at its middle, thereby to form a booklet.
The post-processing controller 10 includes a CPU, an image processor, and a storage as well as other electronic circuits and electronic components (of which none are shown). The post-processing controller 10 is connected to, so as to be able to communicate with, a main controller in the image forming apparatus (not shown). In response to instructions from the main controller, by the operation of the CPU, and based on control programs and control data stored in the storage, the post-processing controller 10 controls the operation of the individual blocks provided in the sheet post-processing apparatus 1 to perform processes related to the functions of the sheet post-processing apparatus 1. The first sheet conveyance passage 3, the first sheet discharge portion 4, the second sheet conveyance passage 5, the second sheet discharge portion 6, the third sheet conveyance passage 7, the third sheet discharge portion 8, and the post-processing portion 9 individually receive instructions from the post-processing controller 10 to cooperate so as to perform post-processing on sheets. The functions of the post-processing controller (controller) 10 may be assumed by the main controller in the image forming apparatus.
Next, the construction of the sheet folding portion 100 will be described with reference to
The first folding portion 101 is disposed on the first sheet conveyance passage 3. Specifically, the first folding portion 101 is located downstream, in the sheet conveyance direction, of where the punching portion 91 (see
The first folding conveyance passage 102 extends so as to branch off from the first folding portion 101 on the first sheet conveyance passage 3. The first folding conveyance passage 102 extends downward from the first folding portion 101. In the embodiment, the first folding conveyance passage 102 extends substantially vertically downward from the first folding portion 101. The first folding conveyance passage 102 at its lowest end connects to the third sheet conveyance passage 7.
The pair of first folding rollers 103 is disposed on the first folding conveyance passage 102 in the first folding portion 101. The pair of first folding rollers 103 is composed of a first roller 111 and a second roller 112. With one of the first and second rollers 111 and 112 urged to make contact with the other, the pair of first folding rollers 103 forms a first folding nip N1. The sheet having entered the first folding conveyance passage 102 passes through the first folding nip N1 and is conveyed to under the pair of first folding rollers 103.
The second roller 112 doubles as one of the rollers that constitute one of the pairs of conveyance rollers 3r on the first sheet conveyance passage 3.
The first folding guide 104 is disposed in the first folding portion 101, opposite the first folding nip N1. Specifically, the first folding guide 104 is disposed upstream of the first folding nip N1 in the sheet conveyance direction along the first folding conveyance passage 102, that is, over the first folding nip N1 in
The first folding guide 104 is connected to a drive mechanism (not shown), and is reciprocatable in directions toward and away from the first folding nip N1. The first folding guide 104 guides the sheet conveyed along the first sheet conveyance passage 3 to the first folding nip N1.
The second folding portion 105 is disposed on the first folding conveyance passage 102. Specifically, the second folding portion 105 is located on the first folding conveyance passage 102, downstream, in the sheet conveyance direction, of where the pair of first folding rollers 103 is disposed, under the first folding nip N1.
The second folding conveyance passage 106 extends so as to branch off from the second folding portion 105 on the first folding conveyance passage 102. The second folding conveyance passage 106 extends from the second folding portion 105 toward the side face of the sheet post-processing apparatus 1 where the first sheet discharge portion 4 is provided, that is, leftward in
The first sheet conveyance passage 3 has a merging portion 33 located downstream of the first branch portion 31 in the sheet conveyance direction. The second folding conveyance passage 106 merges with the first sheet conveyance passage 3 at the merging portion 33. In other words, the merging portion 33 is located downstream, in the sheet conveyance direction, of the first branch portion 31 on the first sheet conveyance passage 3, and at the merging portion 33, the sheet subjected to a folding process in the sheet folding portion 100 is fed back into the first sheet conveyance passage 3.
Specifically, in the embodiment, the merging portion 33 is located in the vicinity of the first switch guide 311. The first switch guide 311, when located in the second position in which it guides the sheet conveyed from the sheet introduction port 2 along the first sheet conveyance passage 3 to the second sheet conveyance passage 5, guides the sheet subjected to a folding process and merged into the first sheet conveyance passage 3 at the merging portion 33 to the downstream end side of the first sheet conveyance passage 3 in the sheet conveyance direction. The first switch guide 311, when located in the second position, closes at the merging portion 33 the part of the first sheet conveyance passage 3 upstream of it in the sheet conveyance direction.
The pair of second folding rollers 107 is disposed in the second folding portion 105, on the second folding conveyance passage 106. The pair of second folding rollers 107 is composed of the first roller 111 and a third roller 113. With one of the first and third rollers 111 and 113 urged to make contact with the other, the pair of second folding rollers 107 forms a second folding nip N2. The sheet having entered the second folding conveyance passage 106 passes through the second folding nip N2 and is conveyed toward the merging portion 33, that is, toward the left side of the pair of second folding rollers 107 in
The second folding guide 108 is disposed in the second folding portion 105, opposite the second folding nip N2. Specifically, the second folding guide 108 is disposed upstream of the second folding nip N2 in the sheet conveyance direction along the second folding conveyance passage 106, that is, to the right of the second folding nip N2 in
The second folding guide 108 is connected to a drive mechanism (not shown), and is reciprocatable in directions toward and away from the second folding nip N2. The second folding guide 108 guides the sheet conveyed along the first folding conveyance passage 102 to the second folding nip N2.
Next, the operation of the sheet folding portion 100 will be described with reference to
As shown in
In the first folding portion 101, the first folding guide 104 is retracted from the first sheet conveyance passage 3 in a direction away from the first folding nip N1, that is, to over the first sheet conveyance passage 3 in
Subsequently, when the part of the sheet S corresponding to the first fold F1 (see
Subsequently the first folding guide 104 is moved in a direction toward the first folding nip N1 and makes contact with the sheet S. The contact with the first folding guide 104 guides the sagging part of the sheet S to the first folding nip N1 in the pair of first folding rollers 103. As the sheet S passes through the first folding nip N1, the first fold F1 is formed in it as shown in
The timing with which the first fold F1 is formed in the sheet is determined in accordance with the timing with which a sheet sensor (not shown) detects, in the first sheet conveyance passage 3, the downstream end of the sheet S in the sheet conveyance direction, the length of the sheet S in the sheet conveyance direction, and the conveyance speed of the sheet S. The same is true with the timing with which the second fold F2 is formed (described later).
In the second folding portion 105, the second folding guide 108 is retracted from the first folding conveyance passage 102 in a direction away from the second folding nip N2, that is, to the right of the first folding conveyance passage 102 in
The sheet S having passed through the first folding nip N1 is conveyed, starting with its part where the first fold F1 is formed, and with its two regions that extend along the sheet conveyance direction overlapping with each other, along the first folding conveyance passage 102 in a direction away from the pair of first folding rollers 103. An upstream part of the sheet S having passed through the first folding conveyance passage 102 momentarily enters the third sheet conveyance passage 7.
Subsequently, when the part of the sheet S corresponding to the second fold F2 (see
Subsequently, the second folding guide 108 is moved in a direction toward to the second folding nip N2 and makes contact with the sheet S. As shown in
As shown in
As described above, when performing a folding process on a sheet S in the sheet folding portion 100, the post-processing controller 10 first guides the downstream end, in the sheet conveyance direction, of the sheet conveyed from the sheet introduction port 2 into the first sheet conveyance passage 3 via the first branch portion 31 to the second sheet conveyance passage 5, and then reverses the conveyance direction of the sheet to guide the sheet S to the sheet folding portion 100 to perform the folding process on the sheet S. Then, the post-processing controller 10 merges the sheet S subjected to the folding process into the first sheet conveyance passage 3 at the merging portion 33.
With this construction, as shown in
As described above, the sheet folding portion 100 includes the first folding conveyance passage 102, the pair of first folding rollers 103, the first folding guide 104, the second folding conveyance passage 106, the pair of second folding rollers 107, and the second folding guide 108. With this construction, the sheet S passing from the second folding portion 105 on the first folding conveyance passage 102 into the second folding conveyance passage 106 can be passed via the merging portion 33 into the first sheet conveyance passage 3. This contributes to reducing the size of the sheet post-processing apparatus 1.
Moreover, the sheet folding portion 100 includes the first and second rollers 111 and 112 that constitute the pair of first folding rollers 103 and the third rollers 113 that constitute the pair of second folding rollers 107 together with the first roller 111. With this construction, the first roller 111 can be shared between the two pairs of folding rollers, namely the pair of first folding rollers 103 and the pair of second folding rollers 107. This contributes to reducing the size of the sheet folding portion 100, and hence contributes to reducing the size of the sheet post-processing apparatus 1.
Moreover, the sheet post-processing apparatus 1 includes the first sheet discharge portion 4 that is disposed at the downstream end of the first sheet conveyance passage 3 in the sheet conveyance direction and on which the sheet S is discharged and the second sheet discharge portion 6 that is disposed at the downstream end of the second sheet conveyance passage 5 in the sheet conveyance direction and on which the sheet S is discharged. With this construction, in a case where a folding process is performed on the sheet, it is possible to use the second sheet conveyance passage 5 when discharging the sheet S onto the second sheet discharge portion 6 in order to prevent contact between parts of the sheet S. That is, contact between parts of the sheet S is prevented not by additionally providing the second sheet conveyance passage 5; instead, an efficient use of an existing structure is made to prevent contact between parts of the sheet S.
The embodiment specifically described above is in no way meant to limit the scope of the present disclosure, which thus allows for various modifications without departure from the spirit of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-016540 | Feb 2021 | JP | national |
