JP2018135213A - Transport device, image forming device, and post-processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that contact resistance occurs when a to-be-transported medium contacts with a peripheral member such as a transport guide, etc. at position correction and, by the contact resistance, the to-be-transported medium is difficult to follow the motion of position correction means.SOLUTION: This transport device transports a to-be-transported medium, and further comprises position correction means for correcting a position of the to-be-transported medium. A rolling member 80 rotatable at least in a direction crossing to a transportation direction is arranged on one or both of transportation paths on an upstream side in the transportation direction and a downstream side in the transportation direction of the position correction means.SELECTED DRAWING: Figure 16

Description

  The present invention relates to a transport apparatus that transports a transported medium, an image forming apparatus including the transport apparatus, and a post-processing apparatus.

  For example, in an image forming apparatus such as a copying machine or a printer, when a transported medium such as paper or an OHP sheet is transported, an inclination amount (a skew amount) of the transported medium or a lateral shift amount in the width direction is detected. A technique for correcting the transported medium to the correct position and orientation is employed.

  As a conveyance device for performing this type of position correction, Patent Document 1 (Japanese Patent Application Laid-Open No. 2014-88263) discloses a recording medium by rotating a pair of nipping rollers for nipping a recording medium or moving it in an axial direction. A transport device that corrects the position of the lens has been proposed.

  However, as described above, in the technology for correcting the position by moving the transported medium in the transport path, contact resistance is generated when the transported medium comes into contact with a peripheral member such as a transport guide during the position correction. For this reason, this contact resistance may make it difficult for the transported medium to follow the movement of the position correction means such as the pair of clamping rollers. As a result, there has been a problem that the accuracy of position correction decreases.

  In order to solve the above problems, the present invention is a transport apparatus that transports a transported medium and includes a position correcting unit that corrects the position of the transported medium, and transports the upstream side of the position correcting unit in the transport direction. A rolling member that is rotatable at least in a direction crossing the transport direction is disposed on one or both of the transport paths on the downstream side in the direction.

  According to the present invention, the movement of the medium to be transported in the transport path becomes smooth, and the contact resistance generated in the medium to be transported becomes small. Can be performed with higher accuracy.

1 is a schematic diagram illustrating an overall configuration of an image forming apparatus according to an embodiment of the present invention. It is the schematic of a clamping roller pair and its peripheral part. It is the schematic of a clamping roller pair and its peripheral part, Comprising: (a) is a top view, (b) is a side view. It is a perspective view of a clamping mechanism and a drive mechanism for driving the same. It is a figure for demonstrating position correction operation | movement, Comprising: (a) is a top view, (b) is a side view. It is a figure for demonstrating position correction operation | movement, Comprising: (a) is a top view, (b) is a side view. It is a figure for demonstrating position correction operation | movement, Comprising: (a) is a top view, (b) is a side view. It is a figure for demonstrating position correction operation | movement, Comprising: (a) is a top view, (b) is a side view. It is a figure for demonstrating position correction operation | movement, Comprising: (a) is a top view, (b) is a side view. FIG. 6 is a diagram for explaining a method for calculating a positional deviation of a sheet. It is a figure for demonstrating the correction amount of the width direction. It is a figure for demonstrating the pick-up operation of a clamping roller pair. It is a control flowchart which shows the flow to 1st correction | amendment. It is a block diagram of the control part which controls a clamping roller pair. It is a control flowchart which shows the flow of 2nd correction | amendment. It is a figure which shows the structure which used the spherical body as a contact resistance reduction means. It is a perspective view of the conveyance guide by which the spherical body is arrange | positioned. It is sectional drawing of a spherical body unit. It is a figure which shows a mode that the paper was conveyed in the curved part of the conveyance path | route where the spherical body is arrange | positioned. It is a figure which shows the structure which has arrange | positioned the spherical body also to another music part. It is a figure which shows the structure which has arrange | positioned the spherical body also in another music part. It is a figure which shows the structure which has arrange | positioned the spherical body in the outer side in a curved part. It is a figure which shows the structure which attached the several spherical body unit to the base. It is a figure which shows the attachment structure of the spherical body unit with respect to a base. It is a figure which shows the structure which assembled | attached the spherical body and the support spherical body directly to the conveyance guide. It is a figure which shows the structure which provided the inclined surface around the spherical body. It is a figure which shows the structure which enabled change of the protrusion amount of a sphere. It is a figure which shows the structure which made the spherical body protrude in conjunction with the separation operation | movement of a conveyance roller pair, Comprising: (a) is a figure which shows the state which the spherical body does not protrude, (b) shows the state which the spherical body protruded. FIG. It is a figure which shows the structure which used the roller as a contact resistance reduction means. It is a figure which shows the structure which used the air blowing means as a contact resistance reduction means. It is a figure which shows the structure which used the vibration provision means as a contact resistance reduction means. It is a figure which shows the structure which has arrange | positioned the spherical body in the linear conveyance path | route downstream from the clamping roller pair. 1 is a schematic diagram illustrating an overall configuration of an ink jet image forming apparatus. It is the schematic which shows the whole structure of a post-processing apparatus.

  Hereinafter, the present invention will be described with reference to the accompanying drawings. In the drawings for explaining the present invention, components such as members and components having the same function or shape are denoted by the same reference numerals as much as possible, and once described, the description will be given. Omitted.

First, the overall configuration and operation of an image forming apparatus according to an embodiment of the present invention will be described.
In FIG. 1, 1 is a copying machine as an image forming apparatus, 2 is a charging unit that charges the surface of a plurality of (in this case, four) photoconductors 5, and 3 is an exposure that irradiates each photoconductor 5 with exposure light L. , 4 is a developing unit for forming a toner image (image) on each photoconductor 5, 6 is a primary transfer unit (intermediate transfer belt) to which a toner image formed on the photoconductor 5 is primarily transferred, and 7 is toner. A secondary transfer unit (secondary transfer roller) for transferring an image from the primary transfer unit 6 to the paper P, 12 to 14 are a paper feeding unit (paper feeding cassette) in which the paper P is stored, and 20 is an unfixed on the paper P A fixing device for fixing an image, 21 is a fixing roller provided in the fixing device 20, 22 is a pressure roller provided in the fixing device 20, 30 is a conveying device that conveys the paper P along the conveying path, and 31 is a paper A pair of nipping rollers that correct the posture and position of the paper P while conveying the P ) Shows the. In addition to the function as a correction roller, the pair of nipping rollers 31 may have a function as a timing roller that adjusts the conveyance timing of the paper P to the secondary transfer unit 7 (changes the conveyance speed). Further, a separate timing roller may be arranged on the downstream side in the conveyance direction of the pair of clamping rollers 31.

With reference to FIG. 1 and FIG. 2, the operation during normal image formation in the copying machine 1 will be described.
First, the surface of each photoconductor 5 is uniformly charged to a predetermined polarity by the charging unit 2 (charging process). Next, exposure light L is irradiated from the exposure unit 3 to the surface of each photoconductor 5 based on image information obtained from a reading device or a computer, and an electrostatic latent image is formed on the surface of each photoconductor 5. (Exposure process). Then, toners of different colors (for example, yellow, magenta, cyan, black) are supplied from the developing unit 4 to the surface of each photoconductor 5 to form toner images of the respective colors (development process).

  Thereafter, the toner images of the respective colors formed on the respective photoreceptors 5 are primarily transferred so as to overlap the primary transfer unit 6 to form a color image, and then the secondary transfer unit 7 performs the secondary transfer onto the paper P. Is done.

  The paper P is transported from the paper feeding units 12 to 14 selected manually or automatically. For example, when one of the paper feed units 12 and 13 arranged in the copying machine 1 is selected, the paper P is fed by the paper feed roller 41 toward the first curved portion 200 (see FIG. 2) of the transport path. Sent. On the other hand, when the paper feeding unit 14 arranged outside the copying machine 1 is selected, the paper P is fed by the paper feeding roller 41 toward the second curved portion 300 (see FIG. 2) in the transport path. . The first music part 200 and the second music part 300 merge at the junction X and continue to the third music part 400 in the transport path. Therefore, the paper P fed from any of the paper feeding units 12 to 14 passes through the merging unit X and reaches the third music unit 400. Thereafter, the paper P passes through the straight conveyance path 500 and reaches the position of the pair of nipping rollers 31 constituting the alignment unit 51. Then, the position of the sheet P in the width direction and the skew direction is corrected by the pair of nipping rollers 31, and the sheet P is conveyed toward the secondary transfer unit 7.

  The sheet P is conveyed to the fixing device 20 after the toner image is transferred by the secondary transfer unit 7. The paper P transported to the fixing device 20 is fed between the fixing roller 21 and the pressure roller 22 and the toner image is fixed by applying heat and pressure. Then, the paper P is discharged from the copying machine 1.

  When performing duplex printing, as described above, the toner image is transferred to one side (front side) of the paper P through the charging process, the exposure process, and the development process, and the fixing device 20 performs the fixing process. After being broken, the paper P is transported to the reverse transport path 600 (see FIG. 1) without being discharged from the copying machine 1. The paper P transported to the reverse transport path 600 is switched back in the reverse transport path 600 (reversed in the transport direction), passes through the first curved section 200, the third curved section 400, and the straight transport path 500, and then becomes secondary again. It is conveyed to the transfer unit 7. Then, the toner image for the back surface formed through the charging process, the exposure process, and the development process is transferred to the paper P, and after the toner image is fixed by the fixing device 20, the paper P is discharged from the copying machine 1. .

  Although a series of image forming processes has been described above, it is also possible to select one of all the photoconductors 5 to form a single color image or to form a two-color or three-color image. is there.

  Next, the transport device 30 according to the present embodiment will be described in detail. In the following description, “upstream side in the transport direction” in the transport path is referred to as “upstream side”, and “downstream side in the transport direction” is referred to as “downstream side”.

FIG. 3A is a plan view of the sandwiching roller pair 31 and its periphery, and FIG. 3B is a side view thereof.
As shown in FIG. 3, the conveyance device 30 includes a plurality of CISs 100 to 102 as position detection units that detect the position of the paper P, a function as a conveyance unit that conveys the paper P, and a position that corrects the position of the paper P. A clamping roller pair 31 that also functions as a correcting unit is provided. The plurality of CISs 100 to 102 are, in order from the upstream side (the right side in the drawing) of the straight conveyance path 500, a first CIS (first position detection unit) 100, a second CIS (second position detection unit) 101, and a third CIS. The CIS (third position detecting means) 102 will be referred to. The first CIS 100 and the second CIS 101 are disposed on the upstream side of the sandwiching roller pair 31 and on the downstream side of the transport roller pair 44 serving as transport means on the upstream side of the sandwiching roller pair 31. Yes. On the other hand, the third CIS 102 is arranged on the downstream side of the sandwiching roller pair 31 and on the upstream side of the secondary transfer portion 7 {see FIG. 3B}. Each of the CISs 100 to 102 is arranged in parallel to the width direction of the paper P (direction orthogonal to the transport direction), and the relative position and the sandwiching roller pair 31 etc. with respect to the transport direction of the paper P. The positional relationship with the surrounding members is predetermined.

  In recent years, CIS uses a light emitting diode (LED) as a light source for the purpose of downsizing the device, and a contact image sensor (Contact Image Sensor) that directly reads an image with a linear sensor through a lens. (Sensor). Each of the CISs 100 to 102 can detect the side end portion Pa {see FIG. 3A} on one end side in the width direction of the paper P by a plurality of line sensors provided in the width direction of the paper P. . Note that the position detection means is not limited to the CIS, and may be any device that can detect the side edge Pa of the paper P, such as a plurality of photosensors arranged along the width direction of the paper P.

  The pair of nipping rollers 31 includes a correction in the width direction {correction for the positional deviation α in the width direction shown in FIG. 3A} and a skew correction {correction for the positional deviation β in the skew shown in FIG. 3A}. It functions as a matching unit 51 that performs a matching operation. Therefore, the nipping roller pair 31 is centered on the shaft portion 104a provided at the axial center position in the W direction {the sheet conveyance surface (conveyed medium conveyance surface) corresponding to the skew direction in FIG. It is configured to be able to rotate in the rotation direction} and to be movable in the S direction {direction corresponding to the paper width direction (conveyed medium width direction)} in FIG. Note that the sandwiching roller pair 31 may be configured to rotate in the W direction around the position on the end side in the axial direction.

FIG. 4 shows the configuration of the sandwiching roller pair 31 and a drive mechanism for driving it.
As shown in FIG. 4, the sandwiching roller pair 31 is a roller pair having a plurality of roller portions divided in the axial direction, and is rotationally driven by a first drive motor 61 as drive means (first drive means). Drive roller 31a and a driven roller 31b that rotates following the rotation of the drive roller 31a. The sandwiching roller pair 31 conveys the paper P by being driven to rotate while the paper P is sandwiched. The sandwiching roller pair 31 may be a roller pair having one roller portion that extends continuously in the axial direction without being divided in the axial direction.

  The first drive motor 61 is fixed to the frame of the transport device 30. A drive gear 61 a is provided on the motor shaft of the first drive motor 61, and the drive gear 61 a meshes with the gear portion 105 a of the frame-side rotation shaft 105 that rotates together with the drive roller 31 a of the pair of clamping rollers 31. As a result, when the first drive motor 61 is driven, the driving force is transmitted to the drive roller 31 a of the clamping roller pair 31 via the drive gear 61 a and the gear portion 105 a of the frame-side rotating shaft 105.

  The frame-side rotating shaft 105 is moved by the standing portion 104b of the base portion 104 so that the frame-side rotating shaft 105 can similarly move in the S direction as the sandwiching roller pair 31 moves in the S direction (direction corresponding to the paper width direction) in FIG. Held possible. The gear portion 105a of the frame side rotation shaft 105 is formed long enough in the axial direction so that the engagement with the drive gear 61a is maintained even if the frame side rotation shaft 105 moves in the S direction.

  The frame-side rotating shaft 105 and the driving roller 31a of the pair of sandwiching rollers 31 are coupled via a coupling 106 so as to be able to transmit driving. The coupling 106 includes a coupling (shaft joint) such as a constant velocity joint and a universal joint. As a result, even if the shaft angle with respect to the frame-side rotation shaft 105 changes as the pinching roller pair 31 rotates in the W direction in FIG. 4 (the rotation direction in the sheet conveyance surface corresponding to the skew direction), the rotation speed The driving force can be transmitted without any change.

  The driving roller 31a and the driven roller 31b of the pair of clamping rollers 31 are held rotatably around their respective axes by a holding member 72 formed in a substantially rectangular frame shape. The driving roller 31a and the driven roller 31b are each held so as to be movable in the S direction (axial direction) with respect to the holding member 72.

  The holding member 72 is supported so as to be rotatable in the W direction around the shaft portion 104a with respect to the base portion 104 that functions as a part of the frame of the transport device 30 (the copying machine 1). Furthermore, a second drive motor 107 is provided on one end side in the width direction of the base portion 104 as second drive means for rotating the holding member 72 in the W direction around the shaft portion 104a. A gear portion is formed on the surface of the motor shaft 107 a of the second drive motor 107, and this gear portion meshes with a gear portion 72 a formed on one end side in the width direction of the holding member 72. Accordingly, when the second drive motor 107 is rotationally driven in the forward and reverse directions, the holding member 72 and the pair of clamping rollers 31 held by the second drive motor 107 rotate in the W direction around the shaft portion 104a. The motor shaft 107a of the second drive motor 107 is provided with a known encoder so that the rotation amount in the W direction and the forward / reverse direction with respect to the reference position of the sandwiching roller pair 31 are indirectly detected. Has been. In addition, a sufficient gap is provided between the support column 72b on one end side of the holding member 72 and the gear portion 72a, and even if the drive roller 31a and the driven roller 31b slide and move to one end side in the width direction, These rotating shafts are configured not to interfere with the gear portion 72a.

  The frame of the transport device 30 (the copying machine 1) is provided with a third drive motor 108 as third drive means for moving the clamping roller pair 31 in the S direction. A pinion gear is formed on the motor shaft 108 a of the third drive motor 108, and this pinion gear meshes with a rack gear portion 109 provided on the other axial end side of the frame side rotating shaft 105. The rack gear unit 109 is provided so as to be rotatable relative to the frame-side rotation shaft 105, and is configured to slide in the S direction without rotation even when the frame-side rotation shaft 105 rotates.

  The driving roller 31a and the driven roller 31b of the sandwiching roller pair 31 are connected to each other via a connecting member 110 so that they can move in the S direction together. The connecting member 110 is disposed between the coupling 106 and the holding member 72, and is sandwiched between retaining rings 111 provided on the respective rotation shafts of the driving roller 31a and the driven roller 31b. With such a configuration, when the third drive motor 108 is rotationally driven in the forward and reverse directions, the sandwiching roller pair 31 moves in the S direction. Further, a known encoder is provided on the motor shaft 108a of the third drive motor 108 so that the movement amount in the S direction and the forward / reverse direction with respect to the reference position of the pair of clamping rollers 31 are indirectly detected. Has been.

  Hereinafter, the correction operation for correcting the position of the sheet will be described with reference to FIGS. 3 and 5 to 15.

  The paper P sent out from the paper supply unit to the transport device 30 is transported further downstream by the transport roller pair 44 and passes through the first CIS 100 (FIG. 3). When the leading end portion Pb of the paper P reaches the second CIS 101 (FIG. 5), the position of the paper P is detected (hereinafter referred to as “first detection”). Based on the result of the first detection, the positional deviation amount of the paper P in the width direction and the skew positional deviation amount are calculated.

  Specifically, the calculation of the positional deviation amount in the width direction of the paper P based on the result of the first detection is performed based on the position in the width direction of the paper P detected by the second CIS 101 (the side edge portion Pa in the width direction of the paper P). Is compared with a transport reference position K indicated by a straight line parallel to the transport direction in FIG. That is, the distance K1 in the width direction between these positions is calculated as the positional deviation amount α in the width direction of the paper P.

  Next, the positional deviation amount of the skew of the paper P can be calculated from the difference in the end position in the width direction of the paper P detected by each of the first CIS 100 and the second CIS 101. That is, as shown in FIG. 10, when the leading end Pb of the paper P reaches the second CIS 101, the distance K1 and the distance K2 in the width direction from the conveyance reference position K are the first CIS 100 and the second CIS. Detected by CIS 101. Since the conveyance direction distance M1 between the first CIS 100 and the second CIS 101 is determined in advance, tan β = (K1−K2) / M1 and the skew position with respect to the conveyance direction of the paper P A deviation amount β is obtained.

  Based on the positional deviation amount α in the width direction of the paper P and the skew positional deviation amount (skew angle) β obtained as described above, the width direction correction and the skew correction of the paper P are performed by the sandwiching roller pair 31. (This is hereinafter referred to as “first correction”). The amount of skew correction is the skew angle β. The correction amount in the width direction is calculated based on the positional deviation amount α and the skew angle β in the width direction. For example, as shown in FIG. 11, the skew-corrected sheet P ′ having the skew angle β changes in the amount of positional deviation in the width direction from α to α ′. This positional deviation amount α ′ is calculated and used as the correction amount α ′ in the width direction by the pair of nipping rollers 31 (however, the correction amount α ′ varies depending on which position is used to correct the skew angle correction). To do.)

  Here, the sandwiching roller pair 31 is disposed at the reference position shown in FIG. 3A before the first detection. Then, until the sheet P is conveyed to the pair of sandwiching rollers 31, the pair of sandwiching rollers 31 performs a reception operation of moving in the direction opposite to the direction of the first correction by the amount of movement by the first correction. Specifically, as shown in FIG. 12, before the sheet P is sandwiched, the pair of sandwiching rollers 31 rotates about the shaft portion 104a by the angle β in the direction of the arrow W1 and in the direction of the arrow S1. Translate by distance α ′. As a result, the shaft portion 104a moves to the position of the shaft portion 104a ′. Such a pick-up operation is performed by the clamping roller pair 31 after the first detection until the clamping roller pair 31 clamps the paper P (FIG. 5).

  When the leading end portion Pb of the paper P reaches the sandwiching roller pair 31, the sandwiching roller pair 31 grips the paper P (FIG. 6). At this time, as shown in FIG. 6B, the transport roller pair 44 on the upstream side of the sandwiching roller pair 31 is separated from each other, and the sheet P is not sandwiched.

  As shown in FIG. 6A, when the first correction is started, the pair of sandwiching rollers 31 causes the positional deviation amount of the sheet P obtained from the first detection result while sandwiching and transporting the sheet P. Based on this, the position of the sheet P in the skew direction is corrected by rotating in the direction of the arrow W2 around the shaft portion 104a, and the position of the sheet P in the width direction is corrected by moving in parallel in the direction of the arrow S2. To do. Thus, the first correction by the sandwiching roller pair 31 is completed, and the position of the paper P is corrected (FIG. 7).

  FIG. 13 shows a control flow up to the first correction described above, and FIG. 14 shows a block diagram of a control unit related to the first correction.

  As shown in FIG. 13, first, the first CIS 100 and the second CIS 101 detect the paper P (step N1), and the positional deviation amount α in the width direction of the paper P and the positional deviation amount β of the skew are determined. Calculated (step N2). Then, based on the calculated misregistration amounts α and β, a correction amount α ′ in the width direction is calculated (step N3), and a correction amount for the first correction (a skew correction amount β and a correction amount α ′ in the width direction). ) Is determined.

  Based on this correction amount, the encoder count is calculated by each encoder (see FIG. 14) (step N4).

  Then, the determined count number is input to a controller for driving the nipping roller pair 31. Then, according to the input count number, the second drive motor 107 and the third drive motor 108 are driven by the respective motor drivers, and the nipping roller pair 31 rotates in the rotation direction (W direction) in the sheet conveyance surface. Or moving in the width direction (S direction), the pick-up operation is performed (step N5). After the nipping roller pair 31 nipping the paper P, the driving of the motors 107 and 108 causes the nipping roller pair 31 to rotate or move in the direction opposite to the pick-up operation while conveying the paper P, and the first correction is performed. Performed (step N6). During the pick-up operation and the first correction, the encoder feeds back the positional information of the pinching roller pair 31 from moment to moment, and controls the pinching roller pair 31 to move by a determined amount of movement. Thereby, the position of the pair of nipping rollers 31 after the completion of the first position correction is closer to the reference position. However, it does not always return to the reference position by the second correction described later.

  As described above, in the present embodiment, the position correction (first correction) of the paper P is performed based on the positional deviation amount of the paper P obtained from the detection results of the first CIS 100 and the second CIS 101. The correction alone may not be sufficient for the positional accuracy required for the paper P.

  In other words, after the first detection, when the paper P is sandwiched between the sandwiching roller pair 31, a force may be applied to the paper P from the sandwiching roller pair 31, and the position of the paper P may be further shifted. Further, it is also conceivable that the position of the paper P is shifted during the correction of the position of the paper P by the sandwiching roller pair 31 and the conveyance to the downstream side. Further, a correction error at the time of the first correction may be considered.

  Therefore, in the transport apparatus according to the present embodiment, the second correction for correcting the position of the paper P is further performed after the first correction. Hereinafter, the second correction will be described.

  After the first correction, when the leading end Pb of the paper P reaches the third CIS 102 (FIG. 8), the position of the paper P is detected again by the third CIS 102 and the second CIS 101 (this will be referred to as the following). , Referred to as “second detection”). Based on the result of the second detection, the amount of misalignment of the paper P is calculated.

  The calculation of the positional deviation amount of the paper P based on the result of the second detection is performed in the same manner as in the first detection, and the detection results of the two CISs provided on the upstream side and the downstream side in the conveyance direction of the paper P are calculated. Based on. That is, the positional deviation amount α in the width direction is obtained from the position in the width direction (position of the side end portion Pa in the width direction) of the paper P obtained by the third CIS 102. Further, the skew displacement amount of the paper P is calculated from each position in the width direction of the paper P obtained by the second CIS 101 and the third CIS 102 and the transport direction distance between the CIS 101 and 102. (In the second detection, the second CIS 101 replaces the first CIS 100 during the first detection, and the third CIS 102 replaces the second CIS 101 during the first detection. Will be detected.)

  Then, based on the positional deviation amount of the paper P calculated from the result of the second detection, the nipping roller pair 31 moves in the direction of the arrow S3 shown in FIG. The second correction is performed by rotating in the direction of arrow W3 about 104a.

  FIG. 15 shows a control flow of the second correction.

  In the second correction, first, the paper P is detected by the second CIS 101 and the third CIS 102 (step N11), and the positional deviation amount (the positional deviation amount in the width direction and the positional deviation amount of the paper P is determined in the same manner as the first correction). A skew position deviation amount) is calculated (step N12). Then, a correction amount is calculated from the calculated positional deviation amount (step N13), and an encoder count number is calculated (step N14). Then, according to the calculated encoder count number, the second drive motor 107 and the third drive motor 108 are driven by the respective motor drivers, and the second correction is performed (step N15).

  In the second correction, the position information of the paper P is detected every moment by the second CIS 101 and the third CIS 102 after the correction is started. Then, the positional deviation amount of the paper P is calculated based on the positional information and fed back to the control unit, and the positional correction amount (encoder count number) of the paper P is corrected every moment. By performing this feedback control, it is possible to reduce the positional deviation of the paper P that occurs during the second correction, the correction error during the second correction, and the like, and it is possible to perform more accurate correction. . However, the second correction may be performed based on the correction amount calculated when the leading edge of the paper P first reaches the third CIS 102 without performing this feedback control.

  As described above, the sheet P subjected to the first correction and the second correction is conveyed toward the secondary transfer unit 7 by the pair of clamping rollers 31. When the sheet P reaches the secondary transfer unit 7 (FIG. 9), the pair of nipping rollers 31 is separated from the sheet P and returns to the reference position again in preparation for position correction and conveyance of the next sheet P {FIG. ) Returns to the reference position by movement in the direction of arrow S4 and rotation in the direction of arrow W4 about the shaft 104a}.

  Incidentally, as described above, in the transport device that moves the paper in the transport path and corrects the position, contact resistance is generated when the paper contacts a peripheral member such as a transport guide or a transport roller pair during the position correction. . And it becomes difficult for the paper to follow the correction operation of the pair of sandwiching rollers due to the influence of such contact resistance, so that the accuracy of the position correction may be lowered. In particular, in a configuration in which there is a curved portion (first to third curved portions 200 to 400) on the upstream side of the sandwiching roller pair 31 as in the present embodiment (see FIG. 2), during position correction by the sandwiching roller pair 31 Since the trailing edge of the sheet is in strong contact with the curved conveyance guide or the like, the contact resistance generated at the trailing edge of the sheet is increased, and it is considered that the followability of the sheet to the correction operation is further reduced.

Therefore, the transport device according to the present embodiment is provided with a contact resistance reducing unit that reduces the contact resistance caused when the sheet comes into contact with surrounding members.
Hereinafter, the contact resistance reducing means will be described.

FIG. 16 is a diagram showing a configuration using a sphere as the contact resistance reducing means.
As shown in FIG. 16, in this embodiment, a plurality of spheres 80, which are rolling members, are arranged as contact resistance reducing means in the third curved portion 400 (upstream of the sandwiching roller pair 31). Each spherical body 80 is arranged so as to protrude upward (conveyance path side) from the lower conveyance guide 120b among the conveyance guides 120a and 120b opposed in the vertical direction for guiding the conveyed sheet. The portion protruding upward (conveying path side) from the lower conveyance guide 120b is a portion smaller than half of the sphere 80, and the center of the sphere 80 is the upper surface (guide surface) of the lower conveyance guide 120b. It is arranged below (on the opposite side to the conveyance path side).

  Each sphere 80 is disposed at a position corresponding to a bent portion (vertex or corner portion of a bent portion) 121 of the lower conveyance guide 120b. In other words, each sphere 80 is disposed at a location where the paper is likely to come into contact, among the upper surface of the lower conveyance guide 120b.

  As shown in FIG. 17, a hole 122 is formed in the bent portion 121 of the lower conveyance guide 120 b, and the spherical body 80 is disposed so as to protrude upward from the hole 122. Moreover, in this embodiment, each spherical body 80 is arrange | positioned in the symmetrical position on both sides on the basis of the width direction center position (position shown with the dashed-dotted line in FIG. 17) in the 3rd music part 400. FIG.

  As shown in FIG. 18, the sphere 80 is assembled in a housing 81 together with a plurality of support spheres 82, and these are configured as one sphere unit 83. The plurality of support spheres 82 are formed to have a smaller diameter than the sphere 80 and are accommodated between the housing 81 and the sphere 80. Since the sphere 80 is supported by a rotatable support sphere 82, the sphere 80 is configured to be rotatable in any arbitrary direction, that is, in the conveyance direction in which the sheet is conveyed and in all directions intersecting with the conveyance direction.

  By providing such a spherical body 80 so as to protrude from the conveyance guide 120b, as shown in FIG. 19, the sheet P is conveyed into the third curved portion 400, and the sheet P is conveyed (by the sandwiching roller pair 31). When the position correction is performed, the sheet P contacts the sphere 80, so that each sphere 80 rotates following the movement of the sheet P in the width direction or the rotation direction in the sheet conveyance surface. Thereby, the paper P can be moved smoothly. At this time, since the paper P is in point contact with the sphere 80, the contact resistance is smaller than when the paper P is in surface contact with the lower conveyance guide 120b. As described above, the movement of the paper P is smoothed by the sphere 80, and the contact resistance generated on the paper P is reduced, so that the followability of the paper P with respect to the position correction operation is improved, and the position correction is performed with higher accuracy. Will be able to do.

  The arrangement, number, and diameter of the spheres 80 may be appropriately determined according to the type and size of the sheet to be conveyed, the curvature of the conveyance path, and the like. In this embodiment, as shown in FIG. 17, the sphere 80 (the sphere 80 on the near side in the figure) is disposed in the vicinity of the pair of conveying rollers 44 so that the sphere 80 comes into contact with papers of various width sizes. Like to do. That is, by arranging the spheres 80 so as not to widen the interval in the width direction, the spheres 80 can be brought into contact with a sheet having a particularly small size in the width direction.

  In the present embodiment, the two spheres 80 arranged on the downstream side in the transport direction (the direction of the arrow in FIG. 17) are wider than the two spheres 80 arranged on the upstream side in the width direction. The interval is wide. As described above, since the spheres 80 can be in contact with the paper at different positions in the width direction by making the width direction intervals between the spheres 80 different between the upstream side and the downstream side, the paper is stabilized by the spheres 80. It becomes easier to support. In addition, it is good also as the space | interval of the width direction of the spherical bodies 80 not only in this but the same space | interval.

  In the present embodiment, each sphere 80 is arranged only in the third music part 400, but the sphere 80 may be arranged in the second music part 300 as in the configuration shown in FIG. Since the path from the second curved section 300 to the third curved section 400 is an S-shaped transport path whose bending direction is reversed in the middle, when the sheet is transported along this path, the sheet with respect to the transport guide Contact resistance can be particularly large. For example, in the case of a long sheet, when the position correction is performed by the sandwiching roller pair 31, the rear end of the sheet is in the second curved portion 300, so that a large contact resistance with respect to the rear end of the sheet. Is expected to occur. Therefore, in order to reduce such contact resistance in the second music part 300, it is effective to arrange the sphere 80 in the second music part 300 as in the configuration shown in FIG. Thereby, the movement of the paper in the S-shaped transport path is smooth, and the followability of the paper to the position correction operation can be improved.

  Moreover, you may arrange | position the spherical body 80 in the 1st music part 200 like the structure shown in FIG. The path from the first curved part 200 to the third curved part 400 is a U-shaped conveyance path in which the bending direction is continuously the same direction. When the trailing edge is passing through the first curved portion 200, contact resistance is generated with respect to the trailing edge of the sheet. For this reason, like the structure shown in FIG. 21, by arranging the spherical body 80 also in the first music part 200, the contact resistance in the first music part 200 can be reduced, and the paper can be moved smoothly. It becomes like this.

  In the embodiment shown in FIG. 16, each sphere 80 is arranged on the inner side (the opposite side to the direction in which the third curved portion 400 swells) in the third curved portion 400, but as in the configuration shown in FIG. The sphere 80 may be disposed outside the third music part 400. Since the contact point of the paper in the transport path differs depending on the shape of the transport path, the rigidity of the paper, and the like, there are various conditions on whether the sphere 80 is arranged on the inner side, the outer side, or both of the curved portions. What is necessary is just to determine suitably according to.

  As the material of the sphere 80, metal, resin, glass, or the like can be used. Further, the surface of the sphere 80 may be coated. For example, when the sphere 80 is made of a steel ball, it is possible to suppress vibration noise during rotation by coating the surface of the steel ball with a resin.

  Further, it is desirable that the sphere 80 is processed so that the toner does not easily adhere thereto. If there are slight scratches on the surface of the sphere 80, toner adheres to the surface and accumulates, and when the paper comes into contact with the sphere 80, rubbing marks are generated on the image, or smooth rotation of the sphere 80 is hindered. Become a factor. In particular, when performing double-sided printing as in the copying machine according to the present embodiment, the toner image fixed on the front side of the paper comes into contact with the sphere 80 during conveyance of double-sided printing, so a part of the toner adheres to the sphere 80. there's a possibility that. Therefore, it is desirable that the sphere 80 is made of a stainless steel or brass metal sphere, a glass sphere, or a resin sphere that is mirror-finished by a method such as lapping so that the toner does not easily adhere to the surface.

  Further, in order to improve the followability of the sphere 80 to the movement of the sheet at the time of position correction, the sphere 80 may be reduced in mass to reduce rolling resistance. For example, the core material (core part) of the sphere 80 is made of plastic, and the surface thereof is subjected to hard plating such as bright nickel or bright chrome so that smoothness and hardness can be obtained while having a low mass. In addition, when smoothness, hardness, and low friction are insufficient, a process of applying diamond coating (DLC) or the like to the sphere surface is effective. Further, such surface processing may be performed on the support sphere 82. Thereby, the smoothness, hardness, and low friction property of the support sphere 82 are improved, and more stable rotation of the sphere 80 can be obtained.

  When arranging a plurality of spheres 80 in the conveyance path, if a sphere unit (see FIG. 18) composed of the sphere 80, the support sphere 82, and the housing 81 is attached to the conveyance guide one by one, especially when the number of sphere units to be attached is large. It will be a hard work. In addition, a structure for attaching the spherical units one by one is required. For example, when a screw hole for fixing the sphere unit, a positioning hole for positioning the sphere unit, or the like is provided in the conveyance guide, it is considered that these obstruct the movement of the sheet.

  Therefore, as shown in FIG. 23, a base 85 that is formed so as to extend in the paper width direction and in which a plurality of sphere units 83 are attached may be prepared in advance and attached to the conveyance guide. . As shown in FIG. 24, a recess 85a is formed on the back surface (surface opposite to the conveyance path side) of the base 85, and the spherical unit 83 is fitted and fixed in the recess 85a. A spherical body 80 is rotatably attached to the base 85. In order to attach such a base 85 to the transport guide, the spherical bodies 80 attached to the base 85 are aligned with the holes 122 (see FIG. 17) provided in the transport guide, and both ends of the base 85 are aligned. A fastener such as a screw is inserted into the hole 85b (see FIG. 23) provided in the guide and fastened to the conveyance guide. Further, by attaching a plurality of such bases 85 to the transport guide in the transport direction, the spherical units 83 can be arranged side by side in the transport direction.

  In this way, by attaching a plurality of sphere units 83 to one base 85 in advance, it is easy to attach the sphere unit 83 to the transport guide. Furthermore, the mounting accuracy of each sphere unit 83 can be improved. In addition, since it is not necessary to provide screw holes, positioning holes, and the like for attaching the sphere units 83 one by one in the conveyance guide, the sheet is prevented from being caught on the conveyance guide, and the sheet can be moved more smoothly during position correction. It becomes like this.

  In the above example, the sphere unit 83 is attached to the conveyance guide. However, the sphere 80 and the support sphere 82 may be directly assembled to the conveyance guide 120 as shown in FIG.

  In the configuration shown in FIG. 25, the curved conveyance guide 120 is integrally molded with resin, and the sphere 80 and the support sphere 82 are directly assembled thereto. The conveyance guide 120 is provided with a sphere housing portion 123 in which a hole into which the sphere 80 is fitted and two grooves into which the support spheres 82 are fitted are formed. The sphere 80 and the support sphere 82 are inserted and accommodated in the sphere accommodating portion 123 from the back side of the conveyance guide 120 (the opposite side to the conveyance path side indicated by the dotted arrow). With the sphere 80 and the support sphere 82 accommodated in the sphere accommodating portion 123, the lid member 124 is attached to the opening of the sphere accommodating portion 123 from the back side of the conveyance guide 120, so that the sphere 80 and the support sphere 82 are detached. Is prevented.

  Thus, by directly assembling the sphere 80 and the support sphere 82 to the transport guide 120, it is possible to reduce the cost, reduce the size, and improve the efficiency of the assembling work. That is, since the conveyance guide 120 also functions as a housing that holds the sphere 80 and the support sphere 82, it is not necessary to provide a separate housing, and the number of parts can be reduced.

  In addition, as in the configuration illustrated in FIG. 26, an inclined surface 84 that is inclined toward the conveyance path side (upward in the drawing) toward the sphere 80 may be provided around the sphere 80. Since the inclined surface 84 is on the upstream side (right side in the drawing) of the sphere 80, the leading edge of the sheet can easily ride on the sphere 80 smoothly. Thereby, it is possible to prevent the occurrence of skew due to the leading end of the sheet contacting (collision) with the sphere 80, and it is possible to prevent the skew amount of the sheet from increasing and exceeding the correctable range. Further, since the inclined surface 84 is on the downstream side (the left side in the figure) of the sphere 80, it is possible to reduce the generation of sound due to the trailing edge of the paper bouncing at the step of the sphere 80, particularly during thick paper conveyance or high-speed conveyance. Silence can be maintained.

  In the configuration shown in FIG. 26, the inclined surface 84 is integrally formed with the housing 81, but an inclined surface having a similar function may be provided in the conveyance guide. For example, when the conveyance guide is made of sheet metal, the inclined surface can be formed by bending the edge of the hole 122 for projecting the sphere 80. In addition, the inclined surface 84 may be formed separately for each sphere 80. When a plurality of spheres 80 are arranged at a narrow interval in the width direction, the inclined surface 84 is formed continuously in the width direction. Also good.

  Moreover, you may comprise so that the protrusion amount of the spherical body 80 with respect to a conveyance guide can be changed. In the configuration shown in FIG. 27, a protrusion amount changing mechanism 86 that changes the protrusion amount A of the sphere 80 with respect to the conveyance guide 120a is provided. The protrusion amount changing mechanism 86 includes a slide member 88 that slides along a columnar guide member 87 fixed to the frame of the copying machine, a cam member 90 that slides the slide member 88 against the biasing force of the spring 89, and the like. A motor 91 or the like is provided as drive means for driving the cam member 90. A sphere unit 83 is attached to the slide member 88. When the slide member 88 slides, the sphere 80 moves in a direction protruding from the conveyance guide 120a and the opposite direction. The motor 91 is a stepping motor, and rotates the cam member 90 by a predetermined angle from the home position (initial position) detected by the home position sensor 92 by rotating a predetermined number of steps. When the cam member 90 rotates and the slide member 88 is pushed to the left in FIG. 27 by the cam member 90, the protruding amount A of the sphere 80 with respect to the conveyance guide 120a increases. On the other hand, when the cam member 90 rotates in the reverse direction, the slide member 88 is pulled back to the right side in FIG.

  Further, the protrusion amount changing mechanism 86 uses the paper type (rigidity and thickness) input by the user through the operation panel 93 or the paper type detected by the paper type detection sensor 94 provided in the copying machine. Based on this, it is configured to be adjustable (changeable) to a preset optimum projection amount A of the sphere 80. Information on the type of paper that is input or detected is sent to a control unit 95 comprising a CPU or the like provided in the copying machine, and the motor 91 gives an instruction to the motor controller 96 based on the type of paper, so that the motor 91 The cam member 90 rotates by a predetermined number of steps to rotate the cam member 90 by a predetermined angle. Thereby, the protrusion amount A of the sphere 80 is adjusted to an optimum amount for the type of paper.

  For example, when the sheet is a thin sheet having a thickness of 0.2 mm or less, even if the projection amount A is small, the leading end of the sheet is likely to be deformed due to contact resistance with the sphere 80. For this reason, there is a concern that the accuracy of detection of misalignment of the paper and the quality of the printed matter may be deteriorated due to the deformation at the leading end of the paper. It is also conceivable that extra skew occurs due to the leading edge of the paper contacting (colliding) with the sphere 80. Therefore, when transporting such thin paper, the sphere 80 is not projected from the transport guide 120a (the projection amount A is 0 or minus), and the leading edge of the sheet passes the position of the sphere 80. After that, the sphere 80 may be protruded from the conveyance guide 120a. As a result, it is possible to avoid the occurrence of deformation and skew due to the leading end of the paper contacting (collising) the sphere 80. Further, the timing of projecting the sphere 80 is performed before the paper position correction is started, so that the paper can be smoothly moved by the sphere 80 during the position correction. Note that the timing at which the leading edge of the sheet passes the position of the sphere 80 can be grasped by a sheet position detection sensor provided in the conveyance path.

  In FIG. 27, only one sphere unit 83 is shown, but if a plurality of sphere units 83 are attached to one slide member 88, it is possible to simultaneously change the protruding amounts A of the plurality of spheres 80. Moreover, you may provide the protrusion amount change mechanism 86 shown in FIG. 27 for every some sphere 80 or some sphere row | line | column. In this case, the plurality of cam members 90 are configured to rotate by one motor 91 using a gear, a timing belt, or the like, thereby simultaneously moving the plurality of spheres 80 or the plurality of sphere rows by the same displacement amount. Is possible.

  In the configuration shown in FIG. 28, the protruding operation of the sphere 80 with respect to the transport guide 120b is interlocked with the separating operation of the transport roller pair 44. In this configuration, the sphere 80 is configured to be interlocked with the contact / separation operation of the conveying roller pair 44 (in this case, the contact / separation operation of the driven roller 44b with respect to the drive roller 44a) by the link mechanism 97.

  As shown in FIG. 28A, in a state where the conveyance roller pair 44 is in contact with each other, the sphere 80 is held in a state where it does not protrude upward (conveyance path side) from the conveyance guide 120b. In this state, as shown in FIG. 28B, when the conveying roller pair 44 is separated from each other, the link mechanism 97 operates in conjunction with the separating operation, so that the sphere 80 moves upward from the conveying guide 120b. It is switched to the state which protruded to. Thereafter, when the conveying roller pair 44 returns to a state where they are in contact with each other, the sphere 80 is returned to a state {the state shown in FIG. 20A) that does not protrude from the conveying guide 120b by an urging means such as a spring.

  As described above, the configuration can be simplified and miniaturized by switching the spherical body 80 to the protruding state in conjunction with the separating operation of the conveying roller pair 44. That is, since the drive source for projecting the sphere 80 can be shared with the drive source for separating the conveyance roller pair 44, it is not necessary to provide a dedicated drive source for projecting the sphere 80. Also in this configuration, as in the configuration shown in FIG. 27, the sphere 80 is not protruded from the conveyance guide 120b until the leading edge of the sheet passes the position of the sphere 80. It can be avoided that the leading edge of the sheet contacts (collises) with the sphere 80. In addition, after the leading edge of the sheet passes the position of the sphere 80, the conveying roller pair 44 is separated from each other at a timing before the position correction of the sheet is performed, so that the sphere 80 protrudes in conjunction with this. Thus, the sheet can be moved smoothly during position correction.

  In the configuration described above, the sphere 80 that can rotate in any direction is used as the rolling member that rotates in contact with the paper. However, a member other than the sphere 80 may be used. For example, in a configuration in which the paper is moved only in the width direction to correct the position of the paper, a roller 130 that can rotate in the width direction may be used as a rolling member, as shown in FIG. In this case, since the paper can smoothly move in the width direction when the paper contacts the roller 130, the followability of the paper to the position correction operation can be improved.

  Further, the rotation direction of such a roller 130 is significantly limited as compared with the spherical body 80. However, the roller 130 that can rotate in the width direction is not limited to a conveyance device that only corrects the width direction of the paper, but as described above. The present invention may be applied to a transport device that can correct both the width direction and the skew direction of the paper, or a transport device that can only correct the skew direction of the paper. Even in such a case, since the paper can be smoothly moved in the width direction, it is expected that the followability of the paper to the position correction operation is improved to some extent. The rotation direction of the roller 130 is not limited to the direction orthogonal to the conveyance direction, and can be appropriately set in any direction as long as the width direction intersects the conveyance direction. Needless to say, the sphere 80 is not limited to the conveyance device that can correct both the width direction and the skew direction of the paper as described above, and the conveyance device that can only correct the width direction of the paper, and the skew of the paper. The present invention is also applicable to a transfer device that can only correct the direction.

  Hereinafter, the structure using things other than a rolling member as a contact resistance reduction means is demonstrated.

  In the configuration shown in FIG. 30, an air blowing means 140 for blowing out air is provided as the contact resistance reducing means. The air blowing means 140 is a member in which a plurality of very small blowing holes 140a are formed, and the blowing holes 140a are closer to the conveyance path than the conveyance guides 120a and 120b from the openings provided in the conveyance guides 120a and 120b. It is arranged so as to protrude slightly. The air blowing means 140 is configured such that air is sent from an air compressor 141 as an air supply means, and the sent air is blown out from the blowing holes 140a toward the conveyance path. In the configuration shown in FIG. 30, the air blowing means 140 is arranged in each of the first music part 200, the second music part 300, and the third music part 400, but the air blowing means 140 is the same as the rolling member. Moreover, what is necessary is just to select and arrange | position a required location from these music parts 200-400. Further, it is desirable that the air blowing means 140 is arranged in the width direction so as to be compatible with the paper widths of all sizes used.

  As described above, since the air blowing means 140 is arranged in each of the curved portions 200 to 400, when the paper is conveyed into the curved portions 200 to 400, the air blown from the air blowing means 140 is used. Contact resistance between the sheet and the conveyance guides 120a and 120b can be reduced. That is, the air (airflow) blown out between the paper and the conveyance guides 120 and 120b causes the paper to float (separate) from the conveyance guides 120a and 120b by a small amount. Therefore, the paper and the conveyance guide 120a. , 120b can be reduced in contact resistance. As a result, contact resistance in the transport direction and in all directions intersecting with this can be reduced, and the followability of the sheet to the position correction operation can be improved, so that position correction can be performed with higher accuracy. .

  In the configuration shown in FIG. 30, the air valve 142 as a blowing amount adjusting means for adjusting the amount (strength) of air sent from the air compressor 141, and the type of paper (rigidity) input by the user on the operation panel 144 And a control unit 143 for controlling the air valve 142 based on the thickness). As a result, the air valve 142 adjusts the amount of air blown out from the air blowing means 140 by changing the opening amount of the air flow path based on the input paper type.

  As described above, the control unit 143 controls the air valve 142 based on the type of paper, so that the amount of air blown out from the air blowing means 140 (outlet strength) is optimized for each type of paper. Can be adjusted. In general, thicker and more rigid paper tends to have stronger contact with peripheral members such as a conveyance guide. Therefore, by increasing the amount of blowout (intensity) of such a sheet, the sheet is conveyed to the conveyance guide. It is possible to reduce the contact resistance by reliably floating from the surface.

  Next, in the configuration shown in FIG. 31, vibration applying means 150 for applying vibration to the paper is provided as the contact resistance reducing means. The vibration applying unit 150 includes a vibrator 150a, a horn 150b, and a vibration unit 150c. For the vibrator 150a, a piezoelectric element (piezoelectric element) that is vibrated by a vibration wave transmitter 151 is used. Further, a stainless steel horn 150b is joined to the vibrator 150a, and the vibration of the vibrator 150a is amplified by the horn 150b. In addition, a vibration unit 150c is joined to the horn 150b, and the vibration amplified by the horn 150b is transmitted to the vibration unit 150c, so that the vibration unit 150c vibrates. The vibration unit 150c is disposed so as to slightly protrude from the openings provided in the transport guides 120a and 120b to the transport path side than the transport guides 120a and 120b. In the configuration shown in FIG. 31, the vibration applying means 150 is disposed in each of the first music part 200, the second music part 300, and the third music part 400. However, the vibration application means 150 is not limited to the rolling member or the air. Similar to the blowing means, it is only necessary to select and place a necessary portion from these music parts 200 to 400. In addition, it is desirable that a plurality of vibration applying means 150 are arranged in the width direction so that vibration can be applied corresponding to the width through which all sizes of paper to be used pass.

  As described above, since the vibration applying means 150 is disposed in each of the curved portions 200 to 400, when the paper is conveyed into the curved portions 200 to 400, the paper contacts the vibration applying means 150 and vibrates. Is applied, it is possible to reduce the contact resistance between the sheet and the conveyance guides 120a and 120b. That is, when the sheet vibrates, the sheet floats (separates) by a small amount with respect to the transport guides 120a and 120b, and thus the contact resistance between the sheet and the transport guides 120a and 120b can be reduced. Thereby, the contact resistance in the transport direction and all directions intersecting with it is reduced, and the followability of the sheet to the position correction operation is improved, so that the position correction can be performed with higher accuracy.

  In the configuration shown in FIG. 31, the vibration adjusting unit 152 that adjusts the frequency and amplitude of the vibration wave generated by the vibration applying unit 150 and the type of paper (rigidity and thickness) input by the user through the operation panel 154. And a control unit 153 for controlling the vibration adjustment unit 152 based on the above. As a result, the vibration adjustment unit 152 adjusts the frequency and amplitude of the vibration wave based on the input paper type.

  As described above, the control unit 153 controls the vibration adjustment unit 152 based on the type of paper, thereby adjusting the frequency and amplitude of the vibration wave generated by the vibration applying unit 150 to optimum values for each type of paper. Can do. The vibration wave generated by the vibration applying means 150 has a frequency of approximately 40 to 60 KHZ and an amplitude of 15 to 30 μm. Particularly, a thick and highly rigid sheet is formed by increasing the frequency or increasing the amplitude. The contact resistance can be reduced by reliably floating from the conveyance guide or the like.

  The contact resistance reducing means (the sphere 80, the roller 130, the air blowing means 140, and the vibration applying means 150) included in the conveyance device according to the present invention has been described above, but the present invention is not limited to the above-described configuration. Of course, various modifications can be made without departing from the scope of the present invention.

  In the above-described configuration, the contact resistance reducing means is arranged in the curved portion, but the curved portion is not limited to one formed only by a continuous curve, and a plurality of straight lines having different angles are formed by bending portions (corner portions). It may be formed by combining them continuously or by combining a curve and a straight line.

  Further, in the above-described configuration, the contact resistance reducing means is disposed on the curved portion on the upstream side of the sandwiching roller pair 31, but not limited to such a location, You may arrange | position a contact resistance reduction means in a linear conveyance path | route. For example, in the case where the sphere 80 is used as the contact resistance reducing means, as shown in FIG. 32, the sphere 80 is arranged in the linear conveyance path 500 between the pair of sandwiching rollers 31 and the secondary transfer unit 7 as shown in FIG. May be. In the configuration in which the sheet position correction (second correction) is performed even after the leading end of the sheet has passed the pinching roller pair 31 as in the above-described copying machine, the sheet is not moved in the linear conveyance path 500 during the position correction. Contact resistance may occur at the tip. For this reason, as shown in FIG. 32, by arranging the sphere 80 in the linear transport path 500, the leading edge of the sheet can move smoothly, and the followability of the sheet to the position correction operation can be improved.

  Further, in the above-described configuration, the present invention is applied to a transport device that transports paper, but the present invention is not limited to paper (including plain paper, cardboard, thin paper, coated paper, label paper, envelopes, etc.) The present invention can also be applied to a recording medium on which an image such as an OHP sheet or an OHP film is printed, or a conveyance device that conveys a sheet such as a document. Furthermore, the present invention is not limited to a sheet such as a recording medium or a document, but can also be applied to a transport device that transports a transported medium such as an electronic substrate.

  Further, the conveying device according to the present invention is not limited to the one mounted on the color image forming apparatus as shown in FIG. 1, but the one mounted on the monochrome image forming apparatus or the image forming apparatus other than the electrophotographic system (for example, Ink jet type image forming apparatus, offset printing machine, etc.) may be used.

FIG. 33 shows an example of a transport device mounted on an inkjet image forming apparatus.
An image forming apparatus 700 illustrated in FIG. 33 includes an image forming unit 701 including a plurality of ejection heads 705 that eject ink by an inkjet method, a paper feeding unit 702 that supplies paper, a transport device 706 that transports paper, and an image. A drying unit 703 that dries the paper on which the paper is formed, and a paper discharge unit 704 that discharges the dried paper. The transport device 706 includes a plurality of CISs 708 to 710 as position detecting means for detecting the position of the paper on the transport path from the paper supply unit 702 to the image forming unit 701, and the detection result of each paper based on the detection results of the CISs 708 to 710. A clamping roller pair 711 is provided as position correcting means for performing position correction. The paper supplied from the paper supply unit 702 is corrected by the position in the width direction or the skew direction based on the detection results of the CISs 708 to 710 while being conveyed by the pair of nipping rollers 711 and then to the image forming unit 701. It is conveyed. The image forming unit 701 forms an image by ejecting ink of each color from the ejection head 705 onto the paper. Thereafter, the paper is dried by the drying unit 703 and then discharged to the paper discharge unit 704.

  Also in such an ink jet image forming apparatus 700, when the paper position is corrected, a contact resistance is generated when the paper comes into contact with a peripheral member such as a conveyance guide. The contact resistance reducing means 800 (the sphere 80, the roller 130, the air blowing means 140, or the vibration applying means 150) may be arranged in one or both of the upstream and downstream conveying paths. Thereby, the movement of the sheet at the time of position correction becomes smooth, and the followability of the sheet to the position correction operation can be improved.

  The conveying device according to the present invention can also be applied to a post-processing device that performs post-processing on paper discharged from the image forming apparatus.

FIG. 34 shows an example of a transfer device mounted on the post-processing device.
A post-processing device 900 illustrated in FIG. 34 includes a receiving unit 901 that receives a sheet discharged from the image forming apparatus 1, a conveying device 902 that conveys the received sheet, and a folding process, a binding process, or a punching process on the sheet. A post-processing unit 903 that performs post-processing such as the above and a discharge unit 904 that discharges paper are mainly configured.

  The paper received from the receiving unit 901 into the post-processing device 900 is either the first transport path 210 that passes through the post-processing unit 903 or the post-processing by a plurality of transport roller pairs (transport means) 905 provided in the transport device 902. The sheet is transported to the second transport path 220 that continues to the discharge section 904 without passing through the section 903. In addition, the conveyance device 902 includes a plurality of CISs 906 to 908 as position detection means for detecting the position of the sheet, and each CIS 906 on the upstream side of the branching portion Y where the first conveyance path 210 and the second conveyance path 220 are branched. Are provided with a pair of clamping rollers 909 as position correcting means for correcting the position of the sheet based on the detection results of ˜908. While the paper is being conveyed by the pair of nipping rollers 909, the position correction in the width direction or the skew direction is performed based on the detection results of each of the CISs 906 to 908, and then to the first conveyance path 210 or the second conveyance path 220. Be transported.

  Here, even in such a post-processing apparatus 900, when the paper position is corrected by the pair of clamping rollers 909, contact resistance occurs when the paper comes into contact with a peripheral member such as a conveyance guide. In particular, as in the example shown in FIG. 34, the case where the sandwiching roller pair 909 is arranged at the curved portion of the transport path is even more so. Therefore, as in the image forming apparatus described above, in such a post-processing apparatus 900, as shown in FIG. 34, contact resistance reducing means 800 is provided on one or both of the upstream and downstream conveying paths of the pair of sandwiching rollers 909. By disposing (the sphere 80, the roller 130, the air blowing unit 140, or the vibration applying unit 150), the movement of the sheet at the time of position correction becomes smooth, and the followability of the sheet to the position correction operation can be improved.

1 Copying machine (image forming device)
30 Conveying device 31 Nipping roller pair (position correction means)
44 conveying roller pair 80 sphere (rolling member, contact resistance reducing means)
84 Inclined surface 97 Link mechanism 100 First CIS (position detecting means)
101 Second CIS (position detection means)
102 3rd CIS (position detection means)
120 conveying guide 120a conveying guide 120b conveying guide 130 roller (rolling member, contact resistance reducing means)
140 Air blowing means (contact resistance reducing means)
150 Vibration imparting means (contact resistance reducing means)
200 1st music part 300 2nd music part 400 3rd music part 800 Contact resistance reducing means 900 Post-processing device A Protruding amount P Paper (conveyed medium)

JP 2014-88263 A

Claims (14)

A transport device that transports a transported medium and includes position correction means for correcting the position of the transported medium,
A conveying apparatus, wherein a rolling member that is rotatable at least in a direction crossing the conveying direction is disposed on one or both of the conveying path upstream and downstream in the conveying direction of the position correction unit.   The transport apparatus according to claim 1, wherein the rolling member is a sphere that is rotatable in a transport direction and in all directions intersecting with the transport direction. The conveyance path has a curved portion,
The transport apparatus according to claim 1, wherein the rolling member is disposed at the curved portion. A conveyance guide for guiding the medium to be conveyed;
The said rolling member is a conveying apparatus of any one of Claim 1 to 3 arrange | positioned so that it may protrude in the said conveyance path | route side from the said conveyance guide.   The conveyance device according to claim 4, wherein the rolling member is configured to be able to change a protruding amount with respect to the conveyance guide. The rolling member is configured to be switchable between a state protruding from the conveyance guide toward the conveyance path and a state not protruding.
The switch to a state in which the rolling member protrudes at a timing after the leading end of the transport medium in the transport direction passes through the rolling member and before the position correction unit performs position correction of the transported medium. 4. The transfer device according to 4. A pair of conveyance rollers configured to convey the medium to be conveyed on the upstream side in the conveyance direction of the position correction unit, and to be able to contact and separate from each other;
The transport apparatus according to claim 6, further comprising: a link mechanism that switches the rolling member to a protruding state in conjunction with a separation operation of the transport roller pair.   The conveying apparatus of any one of Claim 1 to 7 which provided the inclined surface which inclines toward the said conveyance path | route toward the said rolling member. A transport device that transports a transported medium and includes position correction means for correcting the position of the transported medium,
A transport apparatus comprising: a contact resistance reducing unit that reduces contact resistance caused when the transported medium comes into contact with surrounding members when the position correction unit corrects the position of the transported medium.   The conveying apparatus according to claim 9, wherein the contact resistance reducing unit is an air blowing unit that blows air between the medium to be conveyed and the surrounding members.   The transport apparatus according to claim 9, wherein the contact resistance reducing unit is a vibration applying unit that applies vibration to the transported medium. A position detecting means for detecting the position of the transported medium;
The transport apparatus according to claim 1, wherein the position correction unit corrects a position of the transported medium based on a detection result of the position detection unit.   An image forming apparatus comprising the transport device according to claim 1. A post-processing apparatus that performs post-processing on a transported medium discharged from an image forming apparatus,
A post-processing device comprising the transport device according to claim 1.

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