JP2010024021A - Paper feeder, document feeder, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent damage of a sheet or reduce sheet carrying failures in a paper feeder or the like provided with a sheet separating mechanism for separating sheets one by one. <P>SOLUTION: A storage part 37 is provided between a delivery roll 32 and a document separation part 33 in a carrying guide 36. The storage part 37 is a groove (dent) formed along the axis of a retard roll 35, and has a V-shaped section in this embodiment. Namely, in the carrying guide 36, the storage part 37 is formed by extending a carrying path (the width between an upper guide 36A and a lower guide 36B) once from the delivery roll 32 toward the document separation part 33, and then bending the carrying path to be narrowed. When a sheet is distorted, the distortion of the sheet is stored (evacuated) to the storage part 37, whereby damage of the sheet is prevented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sheet feeder, a document feeder, and an image forming apparatus.

  In an image forming apparatus such as a printer or a copying machine, sheets are sequentially sent out from a sheet bundle stored in a sheet tray and supplied to a subsequent image forming process section. Also in a so-called automatic document reading apparatus, an image is read while sequentially sending documents from a bundle of documents set on a document tray. In these apparatuses, a sheet feeding apparatus that sequentially feeds sheets from a sheet bundle such as a document or a sheet is mounted.

  Here, in the sheet feeding device, so-called double feeding may occur in which a plurality of sheets fed from the sheet bundle are stacked and supplied to the conveyance path. In general, therefore, a sheet separating mechanism for separating sheets one by one is provided in order to prevent double feeding in the sheet feeding device. For example, Patent Document 1 includes a roll that is driven to rotate in the paper feeding direction and a reverse rotation roll that rotates in the direction opposite to the paper feeding direction, and is reverse to the paper feeding direction for sheets that are multi-fed by the reverse rotation roll. A paper feeding device that separates sheets by applying a force of orientation is described.

JP 58-119525 A

By the way, in the sheet separation mechanism in the sheet feeding device, when a plurality of sheets enter the sheet separation mechanism, one of the plurality of sheets is given a conveyance force that promotes conveyance in the sheet conveyance direction, and the other sheet For this, a force is temporarily applied to prevent conveyance so as not to be conveyed downstream in the conveyance direction. At this time, the other sheets are dragged to the downstream side in the conveyance direction by the frictional force with the one sheet, although the conveyance is blocked. As a result, wrinkles or other damage may occur on other sheets that are temporarily blocked from being conveyed. Further, a sheet conveyance failure may occur in the sheet feeding device due to the blockage of the conveyance path due to the damage of the sheet.
An object of the present invention is to prevent damage to a sheet and to suppress occurrence of sheet conveyance failure in a sheet feeding device or the like that includes a sheet separation mechanism that separates sheets one by one.

  The invention according to claim 1 is a feeding unit that feeds out a sheet from a sheet bundle, a separation unit that is provided on the downstream side of the feeding unit in the sheet conveyance direction, and separates the sheets fed from the feeding unit one by one; A sheet guide member provided between the feeding unit and the separating unit and guiding a sheet fed from the feeding unit; and the sheet guiding member is provided between the feeding unit and the separating unit. The sheet feeding device is characterized in that a housing portion that houses the bending of the sheet when the sheet is bent is formed.

According to a second aspect of the present invention, the separation unit includes a first roll that rotates in a sheet conveyance direction and a second roll that rotates in a direction opposite to the sheet conveyance direction, and the accommodation of the sheet guide member. 2. The sheet feeding device according to claim 1, wherein the portion accommodates a deflection generated in the sheet when the sheet is returned by the second roll. 3.
According to a third aspect of the present invention, the sheet guide member is provided on the first roll side and the second roll side to form a sheet conveyance path, and the storage portion is formed on the second roll side. The sheet feeding device according to claim 2, wherein:
The invention according to claim 4 is characterized in that the sheet guiding member is bent so as to once widen the conveying path from the feeding portion side toward the separating portion side and then narrow to form the accommodating portion. The sheet feeding device according to claim 3.

  The invention according to claim 5 includes: a sheet stacking unit that stacks sheets; and a sheet feeding device that sends out the sheets stored in the sheet stacking unit toward a reading position where an image on the sheet is read. The apparatus includes a feeding unit that feeds out the sheet from the sheet bundle, a separation unit that is provided downstream of the feeding unit in the sheet conveyance direction, and separates the sheets fed from the feeding unit one by one, the feeding unit, and the A sheet guide member that is provided between the separation unit and guides the sheet fed from the feeding unit, and the sheet guide member is bent between the feeding unit and the separation unit. In this case, the document feeding device is characterized in that an accommodating portion for accommodating the bending of the sheet is formed.

In the invention according to claim 6, the sheet guide member is provided on the front side and the back side of the conveyed sheet to form a sheet conveyance path, from the feeding unit side toward the separation unit side, 6. The document feeding apparatus according to claim 5, wherein the accommodating portion is formed by bending the conveying path once and then narrowing the conveying path.
The invention according to claim 7 is characterized in that the accommodating portion of the sheet guide member includes a movable member that is movable, and the sheet guide member changes the shape of the accommodating portion by the movable member. Item 6. The document feeder according to Item 5.
According to an eighth aspect of the present invention, in the storage unit of the sheet guide member, a rear end side of one sheet conveyed by the feeding unit passes through the separation unit and is conveyed next to the one sheet. 8. The document feeder according to claim 7, wherein the movable member is moved at a timing when the leading end side of the sheet enters the separating portion to close the accommodating space formed by the accommodating portion.

  The invention according to claim 9 is a sheet stacking unit that stacks sheets, a sheet feeding device that feeds out sheets stored in the sheet stacking unit, and an image forming unit that forms an image on the sheet fed from the sheet feeding device The sheet feeding device includes a feeding unit that feeds the sheet from the sheet bundle, and a separation unit that is provided downstream of the feeding unit in the sheet conveyance direction and separates the sheets fed from the feeding unit one by one. And a sheet guide member that is provided between the feeding portion and the separating portion and guides the sheet fed from the feeding portion, and the sheet guiding member is formed between the feeding portion and the separating portion. The image forming apparatus is characterized in that an accommodating portion is formed for accommodating the bending of the sheet when the sheet is bent in between.

The invention according to claim 10 is characterized in that the accommodating portion of the sheet guide member includes a movable member that is movable, and the sheet guide member changes the shape of the accommodating portion by the movable member. Item 10. The image forming apparatus according to Item 9.
According to an eleventh aspect of the present invention, in the storage unit of the sheet guide member, a rear end side of one sheet conveyed by the feeding unit passes through the separation unit and is conveyed next to the one sheet. The image forming apparatus according to claim 10, wherein the movable member is moved at a timing when the leading end side of the sheet enters the separating portion to close the accommodating space formed by the accommodating portion.

According to the first aspect of the present invention, when the sheet is bent at the separating portion, for example, damage to the sheet can be further suppressed as compared with the case where the present configuration is not provided.
According to the second aspect of the present invention, as compared with the case where the present configuration is not provided, it is possible to more easily escape the bending of the sheet that occurs when the sheet is pushed back by the roll that rotates in the direction opposite to the sheet conveyance direction. be able to.

According to the third aspect of the present invention, it is possible to efficiently accommodate the bending of the sheet caused by the roll rotating in the direction opposite to the sheet conveyance direction, as compared with the case where the present configuration is not provided.
According to the fourth aspect of the present invention, it is possible to more easily transport the sheet toward the separation unit while absorbing the bending generated in the sheet as compared with the case where the present configuration is not provided.

According to the fifth aspect of the present invention, it is possible to supply a sheet while suppressing damage to the sheet, for example, toward an image reading position, for example, as compared with the case where the present configuration is not provided.
According to the sixth aspect of the present invention, as compared with the case where the present configuration is not provided, it is possible to absorb the bending generated in the sheet and to more easily carry the sheet toward the separation unit.

According to the seventh aspect of the present invention, as compared with the case where the present configuration is not provided, in the accommodating portion, a state in which a space for accommodating a deflection that can occur in the sheet is formed, and the accommodated sheet is directed toward the separating portion. The state of extruding can be taken.
According to the eighth aspect of the present invention, the rear end side of one sheet passes through the separation unit and then is conveyed next to the one sheet accommodated in the accommodation unit, as compared with the case without this configuration. It is possible to make the other sheet easier to guide toward the separation portion.

According to the ninth aspect of the present invention, compared to the case where the present configuration is not provided, sheet conveyance failure due to wrinkle damage in the sheet feeding device is further suppressed, and for example, the sheet is supplied toward the image forming unit. It can be realized.
According to the tenth aspect of the present invention, as compared with the case where the present configuration is not provided, in the accommodating portion, a state in which a space for accommodating a deflection that can occur in the sheet is formed, and the accommodated sheet is directed toward the separating portion. The state of extruding can be taken.
According to the eleventh aspect of the present invention, the rear end side of one sheet passes through the separation section and is then conveyed next to the one sheet accommodated in the accommodation section, as compared with the case without this configuration. It is possible to make the other sheet easier to guide toward the separation portion.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
<Embodiment 1>
FIG. 1 is a diagram illustrating an overall configuration of an image forming apparatus 1 according to the present embodiment.
An image forming apparatus 1 shown in FIG. 1 is a multi-function machine that is provided with a copying function, a printing function, and the like, and includes a scanner device 2 and a main body device 3.
The scanner device 2 reads an image of the document P, generates image data, and transmits the generated image data to the main body device 3. The scanner device 2 includes a document feeding unit 10 that sequentially conveys a document P as an example of a sheet from a document (sheet) bundle, and an image reading unit 20 that reads an image of the document P.

  The document feeding unit 10 that functions as a document feeding device includes a scanner sheet feeding unit 30 as an example of a sheet feeding device that supplies the document P to the transport unit 11, a transport path 12 through which the document P is transported, and reading is completed. And a paper discharge container 18 on which the document P is stacked. The transport unit 11 includes a transport path 12 through which the document P is transported, a transport roll 13, a registration roll 14, a platen roll 15, an out roll 16, and a discharge roll 17 in order from the upstream side in the document transport direction.

  The transport roll 13 further transports the document P transported from the scanner paper feeding unit 30 toward the registration roll 14. The registration roll 14 conveys the original P toward the platen roll 15 while performing registration adjustment, and further supplies the original P to a later-described original reading system. The platen roll 15 assists the conveyance of the document P being read by the image reading unit 20. The out roll 16 conveys the document P read by the image reading unit 20 further downstream. The discharge roll 17 further conveys the read original P and discharges it to the paper discharge storage unit 18.

The image reading unit 20 reads an image of the document P conveyed by the document feeding unit 10. The image reading unit 20 has a platen glass 21 on which a document P is placed in a stationary state at the time of reading, and a full-rate carriage 22 that rests under the platen glass 21 or scans the entire platen glass 21 to read an image. And a half-rate carriage 23 that supplies light obtained from the full-rate carriage 22 to the imaging unit.
The full rate carriage 22 is provided with a light source 24 for irradiating light toward the original P and a first mirror 25A for receiving reflected light obtained from the original P. On the other hand, the half-rate carriage 24 is provided with a second mirror 25B and a third mirror 25C that supply the light obtained from the first mirror 25A to the imaging unit.

The image reading unit 20 includes an imaging lens 26 and a CCD image sensor 27. Among these, the imaging lens 26 optically reduces the optical image obtained from the third mirror 25C. The CCD image sensor 27 photoelectrically converts the optical image formed by the imaging lens 26.
Further, the scanner device 2 includes a scanner control unit 28. The scanner control unit 28 controls each unit in the image reading operation of the image reading unit 20 and processes the read image data. The above functions in the scanner control unit 28 are realized by a CPU or the like controlled by a program.

Next, the main body device 3 will be described.
The main body device 3 includes an electrophotographic image forming process unit 40 that forms an image corresponding to image data of each color, and a main body paper feeding unit 90 that supplies the image forming process unit 40 with a sheet S as an example of a sheet. And a main body control unit 56 that performs operation control of each unit, image processing of image data, and the like.
As shown in FIG. 1, a main body sheet feeding unit 90 as an example of a sheet feeding device feeds a sheet S from a sheet tray 91 that stores a bundle of sheets S to be subjected to image formation by the image forming process unit 40. Then, it is conveyed toward the image forming process unit 40. The basic configuration of the main body paper feeding unit 90 in the main body device 3 to which the present embodiment is applied is the scanner paper feeding unit 30 except that the paper S on which an image is formed is supplied to the image forming process unit 40. It is the same. Therefore, the detailed description of the main body sheet feeding unit 90 is omitted.

  The image forming process unit 40 that functions as an image forming unit includes four image forming units of yellow (Y), magenta (M), cyan (C), and black (K) that are arranged in parallel at regular intervals. 41Y, 41M, 41C, 41K (hereinafter collectively referred to as image forming unit 41). Each image forming unit 41 includes a photosensitive drum 42 that forms an electrostatic latent image and holds a toner image, a charger 43 that charges the surface of the photosensitive drum 42, and a photosensitive drum 42 that is charged by the charger 43. An exposure unit 44 that performs exposure based on image data is provided. Each image forming unit 41 further includes a developing unit 45 that develops the electrostatic latent image formed on the photosensitive drum 42 and a cleaner 46 that cleans the surface of the photosensitive drum 42 after transfer.

Further, the image forming process unit 40 includes an intermediate transfer belt 51 onto which the color toner images formed on the photosensitive drums 42 of the image forming units 41 are transferred, and the color toner images from the image forming units 41 to the intermediate transfer belt. A primary transfer roll 52 that sequentially transfers (primary transfer) to 51, a secondary transfer roll 53 that collectively transfers (secondary transfer) the superimposed toner image transferred onto the intermediate transfer belt 51 to the paper S, and a secondary transferred image. Is fixed on the sheet S.
The main body control unit 56 receives image data from an external device such as a personal computer (PC) via a network such as a LAN (Local Area Network) and the image data sent from the image reading unit 20 in advance. The image processing for performing the above processing, the image forming process section 40, and the operation control of various rolls in the main body sheet feeding section 90 are performed. The above functions in the main body control unit 56 are realized by a CPU or the like controlled by a program.
In the above-described example, the main body device 3 is a so-called color machine that forms Y, M, C, and K color images on the paper S, but is not limited to a color machine. For example, the main body device 3 may be a so-called monochrome machine in which the image forming process unit 40 forms only black (K) on the paper S.

FIG. 2 is a diagram for explaining the scanner paper feeding unit 30 and the main body paper feeding unit 90 to which the present embodiment is applied. As described above, in this embodiment, the scanner paper feed unit 30 and the main body paper feed unit 90 have the same basic configuration. Therefore, hereinafter, the scanner sheet feeding unit 30 will be described as a representative example.
The scanner paper feeding unit 30 includes a document stacking tray 31 as an example of a sheet stacking unit for stacking document bundles, a feeding roll 32 that feeds the document P from the document stack loaded on the document stacking tray 31, and a fed document P. And a conveyance guide 36 that guides the conveyance. Further, the scanner paper supply unit 30 includes a document separation unit 33 on the downstream side of the feeding roll 32.

  The feed roll 32 as an example of the feed section is a roll member that rotates clockwise (in the direction of arrow A) in the example shown in FIG. 2, and is provided on the upper side of the document stacking tray 31. The feeding roll 32 is set so as to come into contact with the document P positioned at the top of the document bundle, and sequentially feeds the document P at the top of the document bundle toward the conveyance guide 36 by rotating. That is, in the example shown in FIG. 2, the scanner paper feed unit 30 is a so-called top feed type paper feed mechanism.

  The document separation unit 33 as an example of a separation unit includes a feed roll 34 and a retard roll 35 that face each other, and separates the document P supplied from the feeding roll 32 one by one. As shown in FIG. 2, the feed roll 34 is provided on the upper guide 36A (described later) side, and the retard roll 35 is provided on the lower guide 36B (described later) side. The document separation unit 33 conveys the document P further downstream while sandwiching the document P in a portion (hereinafter, referred to as a nip portion N) between the feed roll 34 and the retard roll 35.

  The feed roll 34 as an example of the first roll is a roll member that rotates clockwise (in the direction of arrow B) in the example shown in FIG. That is, the feed roll 34 rotates in the same direction as the feeding roll 32, and gives a transport force for transporting the document P supplied from the feed roll 32 further downstream in the transport direction. On the other hand, the retard roll 35 as an example of the second roll is a roll member that rotates clockwise (in the direction of arrow C) in the example shown in FIG. That is, the retard roll 35 rotates in the same direction as the feed roll 34 with the document P interposed therebetween. Accordingly, the retard roll 35 gives a conveyance force in a direction to push the document P back to the upstream in the conveyance direction (on the document stacking tray 31 side), contrary to the feed roll 34.

  As shown in FIG. 2, the conveyance guide 36 as an example of a sheet guide member includes an upper guide 36 </ b> A and a lower guide 36 </ b> B that guide conveyance of the document P. Then, the document P is conveyed between the upper guide 36A and the lower guide 36B (hereinafter referred to as the inner side). Further, as shown in FIG. 2, the above-described nip portion N is provided between the upper guide 36A and the lower guide 36B. The conveyance guide 36 constitutes a part of the conveyance path of the document P in the document feeder 10 (see FIG. 1).

As shown in FIG. 2, an accommodating portion 37 is provided between the feeding roll 32 of the conveyance guide 36 and the document separating portion 33. The accommodating portion 37 is provided on the upstream side of the retard roll 35 with respect to the transport direction, and is provided in the vicinity of the retard roll 35 in this example.
The accommodating portion 37 is a groove (dent) formed along the axis of the retard roll 35 (from the front side of FIG. 2 to the back side). And in the example shown in FIG. 2, the cross section of the accommodating part 37 is V-shaped. In other words, the conveyance guide 36 has a conveyance path (width between the upper guide 36 </ b> A and the lower guide 36 </ b> B) once extended from the feeding roll 32 toward the document separation unit 33, and then bent so that the conveyance path is narrowed. 37 is formed.

The cross-sectional shape of the container 37 is set so as to absorb (release) the deflection (described later) of the document P generated when the document P is pushed back when the retard roll 35 pushes the document P back. In other words, the cross section of the accommodating portion 37 is set based on a size that absorbs an amount that the retard roll 35 tries to push back the original P.
As for the cross section of the accommodating portion 37, a preferable shape may be selected so that the resistance is reduced in the conveyance of the original P such as a round shape.

Next, operations of the scanner device 2 and the main body device 3 will be described with reference to FIG.
First, the image reading operation of the scanner device 2 will be described.
The original P supplied by the scanner paper supply unit 30 is transported by the transport unit 11 and passes over the platen glass 21. At this time, the full-rate carriage 22 and the half-rate carriage 23 stand by in a state where they are stopped at the solid line positions shown in FIG. Then, the light source 24 emits light, and light is irradiated toward the original P. The reflected light reflected from the document P is supplied to the imaging lens 26 via the first mirror 25A, the second mirror 25B, and the third mirror 25C. Further, the CCD image sensor 27 reads the optical image formed by the imaging lens 26. Such scanning is performed in the sub-scanning direction of the document P, and the document reading for one sheet of the document P is completed.

  When the original P is read on the platen glass 21, the original P is set on the platen glass 21. When the reading is started, the full rate carriage 22 and the half rate carriage 23 are 2: 1. The movement is started at a rate in the scanning direction (the direction of the white arrow in FIG. 1). At this time, light is emitted from the light source 24 of the full rate carriage 22 toward the original P as described above. Then, the reflected light from the document P is reflected in the order of the first mirror 25A, the second mirror 25B, and the third mirror 25C and guided to the imaging lens 26. The light guided to the imaging lens 26 is imaged on the light receiving surface of the CCD image sensor 27. By performing the scanning operation as described above over the entire document P, the document reading for one sheet of the document P is completed.

Here, the paper feeding operation of the scanner paper feeding unit 30 will be described in detail with reference to FIG.
FIG. 3A shows a state in which the original P is fed from the original bundle by the feeding roll 32, and FIG. 3B shows a state in which a plurality of originals P enter the nip portion N in the original separation unit 33. Is shown.
When the document bundle is set on the document stacking tray 31 and reading is started, the feeding roll 32 starts to rotate clockwise in the example shown in FIG. Then, as shown in FIG. 3A, the uppermost document P (hereinafter referred to as the first document P1) of the document bundle in contact with the feeding roll 32 is given a conveying force by the feeding roll 32, and one sheet is fed. The eye original P1 is conveyed toward the inside of the conveyance guide 36. The first original P1 enters the nip N in the original separation unit 33, is conveyed downstream in the conveyance direction by the feed roll 34, and is further fed to the conveyance unit 11 in the original feeding unit 10 described above.

Here, as shown in FIG. 3A, when the first original P1 is conveyed with a conveying force applied directly from the feeding roll 32, the original P (hereinafter referred to as the original P1) is positioned below the first original P1. The second original document P2) may be conveyed toward the nip portion N in the same manner as the first original document P1 due to frictional force generated between the first original document P1 and the first original document P1. In such a case, a plurality of documents P enter the nip portion N of the document separation unit 33.
At this time, as described above, of the plurality of documents P that have entered the nip portion N, the first document P1 receives the transport force from the feed roll 34, passes through the nip portion N, and is transported downstream in the transport direction. The At this time, in the example shown in FIG. 3B, the second original P2 is not in contact with the feed roll 34 due to the presence of the first original P1, and is in contact with only the retard roll 35. Accordingly, the second document P2 is pushed back to the document stacking tray 31 side by the retard roll 35 with a transport force directed upstream in the transport direction. Similarly, when a plurality of documents P are temporarily sandwiched in the nip portion N, the second document P2 is pushed back upstream in the transport direction by the retard roll 35.

  However, depending on conditions such as the thickness of the original P and the friction coefficient, the second original P2 may not return to the original bundle on the original stacking tray 31 even with the retard roll 35. In this way, when the second original P2 has been subjected to the pushing back force but is difficult to be inserted into the original bundle again, the second original P2 is retarded until the first original P1 passes through the nip N. The conveying force from the roll 35 continues to be applied. As a result, the leading edge of the second document P2 may bend and the shape of the leading edge of the second document P2 may swell. Further, depending on the conditions of the original P, the second original P2 may be buckled on the leading end side.

  On the other hand, as shown in FIG. 3B, the scanner paper feeding unit 30 absorbs the bending generated in the second original P2 and the like in the bending storage space formed by the storage unit 37 in the lower guide 36B. ing. As described above, in the scanner paper supply unit 30 to which the first exemplary embodiment is applied, the conveyance guide 36 is provided with the storage unit 37 to prevent the document P from being damaged or the so-called jam in which the document P blocks the conveyance path. I am trying.

Next, an image forming operation of the main body device 3 will be described.
When the image data received from the PC or the like via the scanner device 2 or the network is formed on the paper S, the main body control unit 56 acquires the image data, and is further predetermined for the acquired image data. Apply image processing. In each image forming unit 41, Y, M, and C color toner images are similarly formed.

  Each color toner image formed by each image forming unit 41 is sequentially electrostatically transferred onto an intermediate transfer belt 51 by a primary transfer roll 52. The synthetic toner image on the intermediate transfer belt 51 is conveyed to a secondary transfer portion in which a secondary transfer roll 53 is disposed as the intermediate transfer belt 51 moves. When the composite toner image is conveyed to the secondary transfer unit, the sheet S is conveyed to the secondary transfer unit by the main body sheet feeding unit 90 in accordance with the timing at which the toner image is conveyed to the secondary transfer unit. At this time, the sheet S is conveyed from the sheet bundle of the sheet tray 91 in the same manner as the scanner sheet feeding unit 30 described above. Then, the composite toner image is collectively electrostatically transferred onto the paper S by the secondary transfer roll 53 in the secondary transfer portion.

  Thereafter, the sheet S on which the composite toner image is electrostatically transferred is peeled off from the intermediate transfer belt 51 and conveyed to the fixing device 54. Then, the image is fixed on the paper S by being subjected to fixing processing by heat and pressure by the fixing device 54. The paper S on which the fixed image is formed is discharged to a paper stacking unit provided in the main body device 3.

  As described above, in the main body device 3 as well, the main body paper supply unit 90 is provided in the same manner as the scanner paper supply unit 30, thereby preventing the paper S from being damaged and the so-called jamming of the paper S blocking the conveyance path. I am trying.

  For example, instead of the retard roll 35 in the document separation unit 33 of the present embodiment, a so-called fixed retard roll in which the roll itself does not rotate, a retard pad that is a plate-like frictional resistance member, or the like may be used. In this case, when the second original P2 dragged by the conveyance of the first original P1 reaches the original separation unit 33, the second original P2 is temporarily prevented from being conveyed by a fixed retard roll, a retard pad, or the like. . At this time, as long as the first original P1 continues to be conveyed, the second original P2 is dragged downstream in the conveying direction, and the original P may bend. Therefore, even when a configuration using a fixed retard roll or the like is adopted, the conveyance guide 36 may be provided with the accommodating portion 37 to suppress damage to the document P and poor conveyance of the document P.

<Embodiment 2>
FIG. 4 is a diagram for explaining the scanner paper feeding unit 70 to which the second exemplary embodiment is applied. In addition, about the same thing as the member etc. which were demonstrated in Embodiment 1, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.
A scanner paper feeding unit 70 as an example of a paper feeding device includes a document stacking tray 31, a feeding roll 32, a document separation unit 33, a conveyance guide 76, a movable storage unit 77 provided in the conveyance guide 76, and a downstream side of the document separation unit 33. Is provided with a document detection sensor 80. As shown in FIG. 4, the conveyance guide 76 in the scanner paper feeding unit 70 according to the second embodiment includes an upper guide 76 </ b> A and a lower guide 76 </ b> B that guide the document P. A part of the transport path of the document P is formed.

  The movable guide member 71 as an example of the movable member is a rectangular plate member configured to be movable in the present embodiment. The movable guide member 71 is provided along the axis of the retard roll 35. The fixing member 73 is a rectangular plate member. Similarly to the movable guide member 71, the fixed member 73 is provided along the axis of the retard roll 35. A movable accommodating portion 77 is formed by the movable guide member 71 and the fixed member 73.

In the example shown in FIG. 4, one end 73a of the fixing member 73 is fixed to the upstream side of the retard roll 35 in the lower guide 36B, and the other end 73b side is separated from the upper guide 76A toward the upstream in the transport direction. It is configured as follows.
On the other hand, a rotating shaft 72 is provided on the downstream side of the document stacking tray 31 in the lower guide 76B. The one end 71 a side of the movable guide member 71 is connected to the rotating shaft 72. Moreover, the other end 71b side of the movable guide member 71 is a free end. Therefore, as shown in FIG. 4, the movable guide member 71 is configured to swing around the rotation shaft 72.
The movable guide member 71 may be driven by connecting a solenoid to the movable guide member 71, for example. Further, a motor or the like may be connected to the rotation shaft 72, and the rotation guide 72 may be rotated to swing the movable guide member 71.

  In the example shown in FIG. 4, the other end 71b of the movable guide member 71 rotates in the clockwise direction around the rotation shaft 72, moves in the direction of the arrow G, and moves to the one end 73a side of the fixed member 73 (indicated by the broken line in FIG. 4). Show). On the other hand, the other end 71b of the movable guide member 71 moves counterclockwise around the rotation shaft 72 in the example shown in FIG. 4, thereby moving in the arrow direction H to the one end side 73b of the fixed member 73 (see FIG. 4). (Indicated by 4 solid lines). In other words, the movable accommodating portion 77 has a state in which a groove (dent) is formed along the axis of the retard roll 35 according to the movement of the movable guide member 71 (hereinafter referred to as an open state), and A state (hereinafter referred to as a closed state) that is substantially parallel to the surface can be taken.

  The document detection sensor 80 is provided on the downstream side of the document separation unit 33 in the example shown in FIG. The document detection sensor 80 detects the presence or absence of the document P transported by the transport guide 76 using, for example, sensor light. The document detection sensor 80 sends the detection result of the document P to the scanner control unit 28.

Next, the operation of the scanner paper feed unit 70 to which the second exemplary embodiment is applied will be described. Hereinafter, as described in the first exemplary embodiment, a case where a plurality of originals are conveyed from the original bundle toward the nip portion N will be described as an example.
5A to 5D are views for explaining the relationship between the open / close state of the movable accommodating portion 77 and the document P. FIG.
First, a bundle of documents is set on the document stacking tray 31, and reading is started. Then, at the timing when the feeding roll 32 starts to rotate, in the example shown in FIG. 5A, the movable guide member 71 rotates clockwise and the movable accommodating portion 77 is closed. Further, the feed roll 34 and the retard roll 35 in the document separation unit 33 also start rotating. Then, the first original P1 is sent out from the original bundle by the feeding roll 32, and the first original P1 reaches the nip portion N.

Eventually, as shown in FIG. 5B, the document P enters the nip portion N, and thereafter the document detection sensor 80 provided on the downstream side of the document separation unit 33 detects the leading edge FE of the first document P1. Then, the feeding roll 32 stops rotating. In the scanner paper supply unit 70 of the present embodiment, when the original P reaches the nip portion N, the subsequent conveyance of the original P is performed by the feed roll 34. Therefore, the rotation of the feeding roll 32 is stopped at the timing when the leading edge FE of the document P passes through the nip portion N, that is, when the document detection sensor 80 detects the leading edge FE of the document P.
Then, at the timing when the feeding roll 32 stops rotating, in the example shown in FIG. 5B, the movable guide member 71 rotates counterclockwise, and the movable accommodating portion 77 is opened. In this way, when the movable accommodating portion 77 is opened, a space for accommodating the bending when the second and subsequent originals P2 are bent is secured. The stage where the first original P1 reaches the nip portion N is also a stage where the second and subsequent originals P2 are also dragged out of the original bundle, reach the nip N, and begin to be pushed back by the retard roll 35. Probability is high. Therefore, at the above timing, the scanner paper feed unit 70 of the present embodiment keeps the movable housing portion 77 open.

Subsequently, as shown in FIG. 5C, the timing when the trailing edge BE of the first document P1 passes through the nip N, that is, the timing when the document detection sensor 80 detects the trailing edge BE of the first document P1. Accordingly, the feeding roll 32 starts to rotate again to convey the second original P2. At this timing, in the example shown in FIG. 5C, the movable guide member 71 rotates clockwise, and the movable accommodating portion 77 is closed.
By setting the movable accommodating portion 77 in a closed state, for example, as described with reference to FIG. 5B, the second original document that has been retracted into the retracting (accommodating) space when the movable accommodating portion 77 is opened. The front end side of P2 is pushed out to the nip portion N side. That is, by pushing up the movable guide member 71 in the movable accommodating portion 77 to the nip portion N side, the second original P2 is guided to the original separation portion 33 to facilitate the conveyance of the second original P2.

  Then, as shown in FIG. 5D, the feeding roll 32 stops rotating at the timing when the document detection sensor 80 detects the leading edge FE of the second document P2. At the timing when the feeding roll 32 stops rotating, the movable accommodating portion 77 is opened as described above. By opening the movable accommodating portion 77, a space is formed that absorbs the bending that may occur in the third document P3 attracted to the document separation unit 33 by the conveyance of the second document P2.

  As described above, in the scanner paper feeding unit 70, the operation described with reference to FIGS. 5A to 5D is similarly performed for the third original P3 and the third original P3 and subsequent originals P. Then, the bundle of documents stacked on the document stacking tray 31 is sequentially conveyed. Focusing on the relationship between the movable accommodating portion 77 and the feeding roll 32 in the operation described above, the movable accommodating portion 77 opens at a timing when the feeding roll 32 starts to rotate, and closes at a timing at which the feeding roll 32 stops rotating. ing.

For driving the movable guide member 71, a drive source such as the same motor as the feeding roll 32 may be used. Below, the specific example corresponding to the operation example demonstrated in FIG. 5 about the case where the same drive source is used for the drive of the movable guide member 71 and the delivery roll 32 is demonstrated.
As described above, the timing for opening the movable accommodating portion 77 is the timing at which the feeding roll 32 stops rotating (see FIG. 5B). At this time, the connection from the drive source to the supply roll 32 is cut off, while the rotational driving force from the drive source is transmitted to the rotary shaft 72. On the contrary, the timing for closing the movable accommodating portion 77 is also the timing when the feeding roll 32 starts to rotate (see FIG. 5C). At this time, the driving force from the driving source is transmitted to the rotating shaft 72 and the feeding roll 32.

  As described above, the scanner paper feed unit 70 to which the second exemplary embodiment is applied includes the movable storage unit 77, so that when the document P is bent, a space for storing the bending is secured and further movable storage is performed. The document P that has been retracted in the retreat space with the portion 77 opened is easily transported downstream in the transport direction.

  Further, although an example has been described in which the movable guide member 71 having a rectangular shape is used as a member for pushing out the leading end side of the document P in the movable accommodating portion 77 of the second embodiment, the present invention is not limited to this. For example, as in the first embodiment, the storage portion itself is configured by a fixed member, and a member that can be advanced and retracted toward the nip portion N is provided in the storage portion. Any mechanism can be used as long as it can guide the nip to the nip portion N.

Further, for example, in the scanner paper supply unit 30 of the first embodiment, the storage unit 37 is provided on the retard roll 35 side, but this is not a limitation. For example, even when the accommodating portion 37 is provided on the feed roll 34 side, the upper guide 36A and the lower guide are provided as long as a space for absorbing the bending generated in the document P or the like is provided inside the conveyance guide 36. It may be formed on either side of 36B.
In the above-described embodiment, the electrophotographic image forming apparatus 1 has been described as an example. However, even in a paper feed mechanism provided in various devices such as an ink jet printer and a facsimile machine having a configuration for taking out a document from a document bundle, the conveyance of a suitable document can be realized by providing the accommodating portion 37 and the like.

<Embodiment 3>
FIG. 6 is a diagram for explaining a scanner paper feeding unit 60 to which the third exemplary embodiment is applied. In the first and second embodiments, the so-called top feed type paper feeding mechanism that sequentially feeds from the topmost document P in the document bundle has been described as an example. On the other hand, the scanner paper feed unit 60 to which the third exemplary embodiment is applied is a so-called bottom feed type paper feed mechanism that sequentially feeds from the lowest document P in the document bundle. In addition, about the same thing as the member etc. which were demonstrated in Embodiment 1, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.
A scanner paper feeding unit 60 as an example of a paper feeding device includes a document stacking tray 61 for stacking document bundles, a feed roll 62 for feeding the documents P from the document stacks stacked on the document stacking tray 61, and a fed document. And a conveyance guide 66 for guiding the conveyance of P. Further, the scanner paper feed unit 60 includes a document separation unit 63 on the downstream side of the feeding roll 62.

  The feed roll 62 as an example of the feed section is a roll member that rotates counterclockwise (arrow D direction) in the example shown in FIG. 6, and is provided below the document stacking tray 61. The feeding roll 62 is set so as to contact the document P positioned at the lowest position of the document bundle, and sequentially supplies the document P positioned at the lowest position toward the conveyance guide 66 by its rotation. Further, the feeding roll 62 is a roll member having a cross section composed of an arc portion and a flat portion as shown in FIG. Then, the feeding roll 62 transports the document P with the arc portion in contact with the document P, and prevents the document P from being transported with the flat portion facing the document bundle. Thus, the feeding roll 62 intermittently conveys the original P by rotating.

  Next, the document separation unit 63 will be described in detail. As described above, the scanner paper feed unit 60 employs a bottom feed type paper feed mechanism. Therefore, for example, the vertical relationship is reversed compared to the top feed type scanner paper feeding unit 30 described with reference to FIG.

  The document separation unit 63 as an example of a separation unit includes a feed roll 64 and a retard roll 65 facing each other, and separates the document P supplied from the feeding roll 62 one by one. As shown in FIG. 6, the feed roll 64 is provided on the lower guide 66B (described later) side, and the retard roll 65 is provided on the upper guide 66A (described later) side. The document separation unit 63 conveys the document P further downstream while the document separation unit 63 sandwiches the document P in a facing portion (hereinafter, referred to as a nip portion N) between the feed roll 64 and the retard roll 65.

  The feed roll 64 as an example of the first roll is a roll member that rotates counterclockwise (arrow E direction) in the example shown in FIG. In other words, the feed roll 64 rotates in the same direction as the feeding roll 62, and gives a conveyance force for conveying the document P supplied from the feeding roll 62 further downstream in the conveyance direction. On the other hand, the retard roll 65 as an example of the second roll is a roll member that rotates counterclockwise (arrow F direction) in the example shown in FIG. That is, the retard roll 65 rotates in the same direction as the feed roll 64 with the document P interposed therebetween. Accordingly, the retard roll 65 gives a transport force in a direction to push the document P back to the upstream in the transport direction (the document stacking tray 61 side).

As shown in FIG. 6, the conveyance guide 66 as an example of a sheet guide member includes an upper guide 66A and a lower guide 66B that guide conveyance of the document P. The original P is conveyed between the upper guide 66A and the lower guide 66B (hereinafter referred to as the inner side).
As shown in FIG. 6, an accommodating portion 67 is provided between the feeding roll 62 of the conveyance guide 66 and the document separating portion 63. The accommodating portion 67 is provided on the upstream side of the retard roll 65 with respect to the transport direction, and is provided in the vicinity of the retard roll 65 in this example.

The accommodating portion 67 is a groove (dent) formed along the axis of the retard roll 65 (from the front side to the rear side in FIG. 6). And in the example shown in FIG. 6, the cross section of the accommodating part 67 is V-shaped. And in the example shown in FIG. 6, the cross section of the accommodating part 67 is V-shaped. In other words, the conveyance guide 66 has a conveyance path (width between the upper guide 66A and the lower guide 66B) once extended from the feeding roll 62 toward the document separation unit 63, and then bent so that the conveyance path is narrowed. 67 is formed.
The cross-sectional shape of the container 67 is set so as to absorb (release) the deflection of the document P that is generated when the document P is pushed back when the retard roll 65 pushes the document P back. In other words, the cross section of the accommodating portion 67 is set based on a size that absorbs an amount that the retard roll 65 tries to push back the original P.

Next, the paper feeding operation of the scanner paper feeding unit 60 in the third embodiment will be described in detail.
FIG. 7 is a diagram for explaining a sheet feeding operation of the scanner sheet feeding unit 60 according to the third embodiment. FIG. 7A shows a state in which the original P is fed from the original bundle by the feeding roll 62, and FIG. 7B shows a state in which a plurality of originals P enter the nip portion N.
The feeding roll 62 starts rotating in accordance with the timing when the bundle of documents P is set on the document stacking tray 61 and the image forming process is started. Then, as shown in FIG. 7A, the lowest document P in the bundle of documents in contact with the feeding roll 62 is conveyed by the feeding roll 62 to the inside of the conveyance guide 66, and further the document. It rushes into the separation part 63. Then, the document P is transported to the downstream side in the transport direction by the feed roll 64 and is sent to the transport unit 11 in the document feed unit 10 described above.

Here, as shown in FIG. 7A, when the lowermost document P (hereinafter referred to as the first document P1) is transported with a conveyance force applied directly from the feeding roll 62, the lowest document. A nip portion of a document P (hereinafter referred to as a second document P2) positioned on the P is similar to the first document P1 due to a frictional force generated between the first document P1 and the second document P2. May head to N. The same applies not only to the second original P2, but also to the original P located on the second original P2. In such a case, a plurality of documents P are conveyed toward the nip portion N.
At this time, the first document P1 out of the plurality of documents P that have entered the nip portion N receives the transport force from the feed roll 64, passes through the nip portion N, and is transported downstream in the transport direction. On the other hand, in the state shown in FIG. 7B, the second original P2 among the plurality of originals P is blocked by the first original P1 and does not contact the feed roll 64 but only the retard roll 65. To do. Then, the second document P2 of the plurality of documents P is given a transport force in the direction from the retard roll 65 toward the upstream side in the transport direction, and is pushed back to the document stacking tray 61 side.

  Here, even if the second original P2 receives a conveying force toward the original stacking tray 61 by the retard roll 65, the second original P2 may not be pushed back as it is. In this case, similarly to the scanner paper feeding unit 30 described with reference to FIG. 3, the document P may be subjected to a conveyance force to the upstream side in the conveyance direction by the retard roll 65, and may be bent at the leading end side. In particular, in the case of the bottom feed method such as the scanner paper feed unit 60 of the present embodiment, a plurality of other documents P are further stacked on the second document P2. In other words, the entire original bundle is loaded on the second original P2, and the difficulty of pushing the second original P2 back onto the original bundle by the retard roll 65 becomes more significant than in the top feed system.

As described above, when the paper travels once toward the nip portion N and is subjected to the pushing back force from the retard roll 65 but is difficult to return to the original bundle, the retard until the first original P1 passes through the nip portion N. The conveying force from the roll 65 continues to be applied to the second original P2. As a result, the leading end portion of the document P may be bent and the shape of the leading end side of the document P may swell.
On the other hand, as shown in FIG. 7B, the scanner paper supply unit 60 absorbs the bending generated in the second original P2 and the like in the retreat space formed by the storage unit 67 provided in the upper guide 66A. I am letting. As described above, even in the scanner paper feeding unit 60 that employs the bottom feed type paper feeding mechanism, the accommodation unit 67 is provided in the conveyance guide 66 so that the document P is damaged or the document P is blocked in the conveyance path. The so-called jam is suppressed.

  As described in the third embodiment, the main body paper feeding unit 90 of the main body device 3 may be a bottom feed type paper feeding mechanism. Even in this case, similarly to the scanner paper feeding unit 60, it is possible to suppress the occurrence of damage to the paper S and the so-called jamming that the paper S is blocked in the transport path. Furthermore, the movable sheet storage unit 77 described in the second embodiment may be provided in the scanner paper feeding unit 60 of the third embodiment.

1 is a diagram illustrating an overall configuration of an image forming apparatus according to a first embodiment. FIG. 5 is a diagram for explaining a scanner paper feeding unit and a main body paper feeding unit to which the first exemplary embodiment is applied. FIG. 6 is a diagram for explaining the operation of the scanner paper feed unit of the first embodiment. FIG. 10 is a diagram for explaining a scanner paper feeding unit to which the second exemplary embodiment is applied. It is a figure for demonstrating the relationship between the open / close state of a movable accommodating part, and a document. FIG. 10 is a diagram for explaining a scanner paper feeding unit to which a third exemplary embodiment is applied. FIG. 10 is a diagram for explaining an operation of a scanner sheet feeding unit according to a third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Scanner apparatus, 3 ... Main body apparatus, 10 ... Document feeding part, 20 ... Image reading part, 30 ... Scanner paper feeding part, 31 ... Document loading tray, 32 ... Feeding roll, 33 ... Document separation , 34 ... feed roll, 35 ... retard roll, 36 ... conveying guide, 37 ... accommodating section, 40 ... image forming process section, 77 ... movable accommodating section, 90 ... main body feeding section, P ... original, S ... paper

Claims (11)

A feeding section for feeding out the sheet from the sheet bundle;
A separation unit that is provided on the downstream side in the conveyance direction of the sheet of the feeding unit, and separates the sheets fed from the feeding unit one by one;
A sheet guide member provided between the feeding unit and the separating unit and guiding a sheet fed from the feeding unit;
The sheet feeding device according to claim 1, wherein the sheet guide member forms an accommodating portion that accommodates the bending of the sheet when the sheet is bent between the feeding portion and the separating portion. The separation unit includes a first roll that rotates in the sheet conveyance direction, and a second roll that rotates in a direction opposite to the sheet conveyance direction,
2. The sheet feeding device according to claim 1, wherein the accommodating portion of the sheet guide member accommodates bending generated in the sheet when the sheet is returned by the second roll.   The sheet guide member is provided on the first roll side and the second roll side to form a sheet conveyance path, and the storage portion is formed on the second roll side. The paper feeder described.   The sheet feeding member according to claim 3, wherein the sheet guide member is bent so as to temporarily widen the conveyance path from the feeding unit side toward the separation unit side and then narrow the sheet. apparatus. A sheet stacking section for stacking sheets;
A sheet feeding device that feeds a sheet stored in the sheet stacking unit toward a reading position for reading an image on the sheet,
The paper feeder is
A feeding section for feeding out the sheet from the sheet bundle;
A separation unit that is provided on the downstream side in the conveyance direction of the sheet of the feeding unit, and separates the sheets fed from the feeding unit one by one;
A sheet guide member provided between the feeding unit and the separating unit and guiding a sheet fed from the feeding unit;
The document feeding device according to claim 1, wherein the sheet guide member forms an accommodating portion that accommodates bending of the sheet when the sheet is bent between the feeding portion and the separating portion.   The sheet guide member is provided on the front side and the back side of the sheet to be conveyed to form a sheet conveyance path, and once widens the conveyance path from the feeding unit side to the separation unit side, and thereafter 6. The document feeder according to claim 5, wherein the accommodating portion is bent so as to be narrowed. The accommodating portion of the sheet guide member includes a movable member that is movable,
The document feeder according to claim 5, wherein the sheet guide member changes a shape of the housing portion by the movable member.   The storage portion of the sheet guide member has a rear end side of one sheet conveyed by the feeding portion passing through the separation portion, and a front end side of another sheet conveyed next to the one sheet is the separation portion. The document feeder according to claim 7, wherein the movable member is moved at a timing of entering into the container to close a housing space formed by the housing portion. A sheet stacking section for stacking sheets;
A paper feeding device for feeding out the sheets stored in the sheet stacking unit;
An image forming unit that forms an image on a sheet fed from the sheet feeding device;
The paper feeder is
A feeding section for feeding out the sheet from the sheet bundle;
A separation unit that is provided on the downstream side in the conveyance direction of the sheet of the feeding unit, and separates the sheets fed from the feeding unit one by one;
A sheet guide member provided between the feeding unit and the separating unit and guiding a sheet fed from the feeding unit;
The image forming apparatus according to claim 1, wherein the sheet guide member forms an accommodating portion that accommodates bending of the sheet when the sheet is bent between the feeding portion and the separating portion. The accommodating portion of the sheet guide member includes a movable member that is movable,
The image forming apparatus according to claim 9, wherein the sheet guide member changes a shape of the housing portion by the movable member.   The storage portion of the sheet guide member has a rear end side of one sheet conveyed by the feeding portion passing through the separation portion, and a front end side of another sheet conveyed next to the one sheet is the separation portion. The image forming apparatus according to claim 10, wherein the movable member is moved at a timing of entering into the housing to close a housing space formed by the housing portion.

Images