JP2014193769A - Carrier device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carrier device and an image forming apparatus, which enable skew correction and lateral registration correction of a recording medium to be performed with a high degree of accuracy, without reducing productivity of the device and the apparatus.SOLUTION: The amount of oblique-direction misregistration of a recording medium P and the amount of width-direction misregistration of the recording medium P are corrected while the recording medium P is carried in the state of being held by a holding roller 31, by a plurality of drive motors 61-63 (drive means) installed in the state of being fixed to a frame of a carrier device (image forming apparatus).

Description

  The present invention relates to a conveyance device that conveys a recording medium, and an image forming apparatus such as a copying machine, a printer, a facsimile, or a multifunction machine or an offset printing machine provided with the same, and more particularly to a recording medium in a conveyance path. The present invention relates to a conveyance device that performs lateral registration correction and skew correction, and an image forming apparatus.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a printer, after correcting a positional deviation (skew) in a diagonal direction of a recording medium in a conveyance path, the width direction of the recording medium (a direction perpendicular to the conveyance direction). There is known a technique for correcting the deviation of the position (hereinafter referred to as “lateral resist” as appropriate) to a regular position (see, for example, Patent Document 1).

  Specifically, in Patent Document 1, the recording medium conveyed along the conveyance path by a plurality of conveyance roller pairs hits the stopper and is subjected to skew correction (skew correction). After that, the recording medium in contact with the stopper moves in the width direction while being pinched by the pair of horizontal registration rollers disposed on the upstream side of the stopper to correct the horizontal registration. Become. Thereafter, the recording medium in which the lateral registration is corrected is conveyed toward the image forming unit.

  On the other hand, in Patent Document 2, a driving roller connected to a coupler and a nip forming roller that presses against the driving roller are provided at both ends in the width direction, and they are moved in the width direction and driven at both ends. There has been disclosed a technique for simultaneously performing skew correction and lateral registration correction of a recording medium by adjusting the speed of a roller.

In the technique of Patent Document 1, since the recording medium is temporarily stopped so as to abut against the stopper and the skew feeding correction is performed, the lateral registration correction of the recording medium is performed. I was sorry.
On the other hand, since the technique of Patent Document 2 simultaneously performs the skew feeding correction and the lateral registration correction of the recording medium while transporting the recording medium without stopping, the productivity of the apparatus is reduced. Absent. However, when thin paper is passed as the recording medium, the recording medium may be bent by adjusting the speed of the driving rollers at both ends, or the recording medium having a low surface friction coefficient (for example, when printing on both sides) When the image is formed on one side of the recording medium), slip adjustment may occur between the recording medium and the roller by adjusting the speed of the driving roller at both ends. In some cases, the accuracy of the skew correction of the medium is lowered.

  The present invention has been made to solve the above-described problems, and is capable of carrying out skew correction and lateral registration correction of a recording medium with high accuracy without reducing the productivity of the apparatus. Another object is to provide an image forming apparatus.

  According to a first aspect of the present invention, there is provided a conveying device for conveying a recording medium in a conveying path, wherein the conveying device is rotated by a first driving unit and conveys the recording medium in a nipped state. A holding member rotatably supported by the holding roller and detecting a positional deviation amount of the recording medium conveyed in the conveyance path in an oblique direction. 1 detection means, second detection means for detecting a positional deviation amount in the width direction of the recording medium conveyed in the conveyance path, and the holding member together with the nip roller based on a detection result of the first detection means. Second driving means configured to be rotatable in a direction, and third driving means configured to be capable of moving the clamping roller in the width direction based on a detection result of the second detecting means, The drive means and the second drive means and said third driving means is obtained by configured not installed in the holding member.

  The present invention corrects the positional displacement amount of the recording medium in the oblique direction while transporting the recording medium in a state of being sandwiched by the sandwiching roller by a plurality of driving means configured not to be installed on the holding member that holds the sandwiching roller. At the same time, the positional deviation amount in the width direction of the recording medium is corrected. Accordingly, it is possible to provide a transport device and an image forming apparatus in which the skew correction and the lateral registration correction of the recording medium are performed with high accuracy without reducing the productivity of the apparatus.

1 is an overall configuration diagram illustrating an image forming apparatus according to Embodiment 1 of the present invention. It is a block diagram which shows a conveying apparatus. It is a top view which shows a part of conveying apparatus. It is a perspective view which shows the principal part of a conveying apparatus. It is the schematic which shows operation | movement of a conveying apparatus. FIG. 6 is a schematic diagram illustrating the operation of the conveyance device following FIG. 5. It is the schematic which shows operation | movement of the conveying apparatus as a modification. FIG. 8 is a schematic diagram illustrating an operation of the conveyance device following FIG. 7. It is a block diagram which shows the principal part of the conveying apparatus in Embodiment 2 of this invention. It is a block diagram which shows the coupling installed in the conveying apparatus of FIG. It is a block diagram which shows the principal part of the conveying apparatus in Embodiment 3 of this invention. It is a block diagram which shows the principal part of the conveying apparatus as a modification.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

Embodiment 1 FIG.
The first embodiment of the present invention will be described in detail with reference to FIGS.
First, the configuration and operation of the entire image forming apparatus will be described with reference to FIG.
In FIG. 1, reference numeral 1 denotes an apparatus main body of a copying machine as an image forming apparatus, 2 an original reading unit that optically reads image information of an original D, and 3 an exposure light L based on image information read by the original reading unit 2. Is exposed to the photosensitive drum 5, 4 is an image forming unit for forming a toner image (image) on the photosensitive drum 5, and 7 is a toner image formed on the photosensitive drum 5 on the recording medium P. A transfer section (image forming section) for transferring, 10 a document transport section for transporting a set document D to the document reading section 2, and 12 to 14 a paper feed section for storing a recording medium P (sheet) such as transfer paper. (Paper feed cassette), 20 is a fixing device for fixing an unfixed image on the recording medium P, 21 is a fixing roller installed in the fixing device 20, 22 is a pressure roller installed in the fixing device 20, and 30 is recording. A transport device 45 for transporting the medium P along the transport path, Part 7 timing roller as conveying rollers for conveying the recording medium P toward the (image forming section) shows.

With reference to FIG. 1, an operation during normal image formation in the image forming apparatus will be described.
First, the document D is conveyed from the document table in the direction of the arrow in the drawing by the conveyance roller of the document conveyance unit 10 and passes over the document reading unit 2. At this time, the document reading unit 2 optically reads the image information of the document D passing above.
Then, the optical image information read by the document reading unit 2 is converted into an electric signal and then transmitted to the exposure unit 3 (writing unit). An exposure light L (laser light) based on the image information of the electrical signal is emitted from the exposure unit 3 toward the photosensitive drum 5 of the image forming unit 4.

On the other hand, in the image forming unit 4, the photosensitive drum 5 is rotated in the clockwise direction in the drawing, and image information is transferred onto the photosensitive drum 5 through a predetermined image forming process (charging process, exposure process, development process). An image (toner image) corresponding to is formed.
Thereafter, the image formed on the photosensitive drum 5 is transferred onto the recording medium P conveyed by the timing roller 45 serving as a conveying roller pair in the transfer unit 7 serving as an image forming unit.

On the other hand, referring to FIGS. 1 and 2, the recording medium P conveyed to the transfer unit 7 (image forming unit) operates as follows.
First, one of the plurality of paper feeding units 12 to 14 of the image forming apparatus main body 1 is automatically or manually selected (for example, the paper feeding unit 12 provided in the main body 1 is selected. )
Then, the uppermost sheet of the recording medium P stored in the paper feed unit 12 is directed by the paper feed roller 41 toward the curved conveyance path where the first conveyance roller pair 42 and the second conveyance roller pair 43 are installed. Be fed.

  Thereafter, the recording medium P passes through the curved conveyance path through the position of the merging portion X (the portion where the conveyance paths from the two paper feeding units 13 and 14 installed outside the apparatus main body 1 merge). The third conveying roller pair 44 and the linear conveying path in which the aligning portion 51 is installed are passed to reach the position of the timing roller 45 (fourth conveying roller pair). Then, the recording medium P that has reached the position of the timing roller 45 is conveyed toward the transfer unit 7 (image forming unit) at the same timing in order to align with the image formed on the photosensitive drum 5. The

After the transfer process, the recording medium P passes through the position of the transfer unit 7 and then reaches the fixing device 20 through the conveyance path. The recording medium P that has reached the fixing device 20 is fed between the fixing roller 21 and the pressure roller 22, and the image is fixed by the heat received from the fixing roller 21 and the pressure received from both members 21 and 22. The The recording medium P on which the image has been fixed is delivered from between the fixing roller 21 and the pressure roller 22 (a nip portion) and then discharged from the image forming apparatus main body 1.
Thus, a series of image forming processes is completed.

Here, referring to FIG. 2, the image forming apparatus 1 according to the first embodiment can feed the recording medium P from the three paper feeding units 12 to 14 toward the transfer unit 7 (image forming unit). It is configured.
Further, the conveyance roller pairs 42 to 45 (including a conveyance roller pair that is not attached with a symbol) installed in the conveyance device 30 are all driving rollers (rollers that are rotationally driven by a driving mechanism (not shown)). And a driven roller (a roller that is driven to rotate by frictional resistance with the driving roller), and is configured to be able to convey the recording medium P while being sandwiched between the two rollers.

  Here, the conveyance from the junction X where the conveyance path from the first sheet feeding unit 12 and the conveyance path from the second and third sheet feeding units 13 and 14 merge to the position of the timing roller 45 is performed. As the path, a linear transport path formed in a substantially straight line along the transport direction of the recording medium P is provided. This linear transport path is formed by a linear transport guide plate (not shown) (installed so as to sandwich the front and back surfaces of the transported recording medium P), and the third transport roller pair 44 along the transport direction. The skew detection sensor 35 (first detection means), the clamping roller 31 (horizontal registration / skew correction roller), the CIS 36 (second detection means), the timing roller 45, and the paper detection sensor 37 (third detection means) are installed. Has been. The third transport roller pair 44, the sandwiching roller 31 and the timing roller 45 are all roller pairs composed of a driving roller and a driven roller, and transport the recording medium P while being sandwiched between two rollers. . The sandwiching roller 31 performs an alignment operation between skew correction (correction for a positional deviation in the oblique direction with respect to the conveyance direction) and lateral registration correction (correction for a positional deviation in the width direction). This will also function as the matching unit 51, which will be described in detail later.

Next, with reference to FIG. 2 to FIG. 6, the characteristic transport device 30 in the first embodiment will be described in detail.
Hereinafter, the configuration in the transport path from the junction X to the transfer unit 7 (image forming unit) and the operations performed there will be mainly described.
2 and 3, the conveyance device 30 includes a third conveyance roller pair 44, along a linear conveyance path of the recording medium P (a conveyance path from the merging portion X to the transfer portion 7). A skew detection sensor 35 as a first detection means, a clamping roller 31 (horizontal registration / skew correction roller), a CIS 36 (contact image sensor) as a second detection means, a timing roller 45, and a third detection means A paper detection sensor 37 is installed.

Here, the sandwiching roller 31 is a roller pair having a roller portion divided into a plurality of parts in the width direction, and a first drive motor 61 as a first drive means (first drive source) (see FIG. 4 can be referred to). And a driven roller 31b that is driven to rotate by the rotation of the driving roller 31a. The drive roller 31a and the driven roller 31b are both roller members in which a plurality of roller portions are formed on the rotation shaft.
Further, the sandwiching roller 31 is configured such that the roller pair can be contacted and separated by a separation mechanism (not shown). That is, the sandwiching roller 31 is formed to be separable so as to be able to switch between a state in which the recording medium P is sandwiched and a state in which the recording medium P is not sandwiched, and is configured to be able to transport the recording medium P by rotating.

  Further, the sandwiching roller 31 is formed so as to be able to rotate in an oblique direction (rotation in the direction of the broken line double arrow W in FIG. 3) and in the width direction (in the direction of the broken line arrow S in FIG. 3). It is formed so that it can move to.

In detail, with reference to FIG. 4, the clamping roller 31 (the driving roller 31a and the driven roller 31b) is rotated by a first driving motor 61 as a first driving means, and is conveyed in a state where the recording medium P is sandwiched. To do.
Specifically, the first drive motor 61 (first drive means) is fixedly installed on a frame (not shown) of the transport device 30 (image forming apparatus 1). The first drive motor 61 has a gear portion 76a (sufficient in the width direction) of the frame-side rotary shaft 76 in which the drive gear 61a installed on the motor shaft is rotatably held by the rising portion 71b of the base portion 71 (frame). The frame-side rotary shaft 76 is rotationally driven in the direction of the arrow in FIG. When the frame-side rotating shaft 76 is driven to rotate, the rotational driving force is transmitted to the rotating shaft of the driving roller 31a through the coupling 75, the driving roller 31a rotates, and is driven to follow the driven roller. 31b also rotates.
Here, the coupling 75 interposed between the rotating shaft of the driving roller 31a and the frame-side rotating shaft 76 held by the frame is a coupling (shaft joint) such as a constant velocity joint or a universal joint. Thus, even if the clamping roller 31 is rotated together with the holding member 72 by the driving of the second drive motor 62, which will be described later, the rotational speed changes even if the shaft angle of the drive roller 31a and the frame-side rotary shaft 76 changes. The rotational driving force is transmitted without the occurrence of.

The sandwiching roller 31 is rotatably held by a holding member 72 (movable member) having a substantially rectangular frame shape, and is held movably in the width direction. Specifically, each of the driving roller 31a and the driven roller 31b has a holding member 72 via bearings (not shown and fixed to the holding member 72) at both ends in the width direction of the rotating shaft. Is held rotatably. The driving roller 31a and the driven roller 31b are each held by a holding member 72 so as to be movable in the width direction (rotating axis direction). In particular, 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 driving roller 31a and the driven roller 31b slide to one end side in the width direction, These rotation shafts are configured not to interfere with the gear portion 72a.
The holding member 72 is supported so as to be rotatable about a shaft portion 71a with respect to a base portion 71 that functions as a part of the frame of the transport device 30 (image forming apparatus 1). Further, a second drive motor 62 as second drive means (second drive source) is fixedly installed on one end side in the width direction of the base portion 71 and formed on the motor shaft 62 a of the second drive motor 62. The formed gear is formed so as to mesh with a gear portion 72 a formed on one end side in the width direction of the holding member 72. Accordingly, the holding roller 72 and the pinching roller 31 are rotated about the shaft portion 71a by the rotational drive of the second drive motor 62 in the forward and reverse directions (rotation in the direction of the double arrow in FIG. In the W direction). The second drive motor 62 (second drive means) is configured to be capable of rotating the holding member 72 in an oblique direction together with the clamping roller 31 based on a detection result of a skew detection sensor 35 (first detection means) described later. It has been done.
In the first embodiment, the sandwiching roller 31 (holding member 72) is configured to rotate around the center position in the width direction. However, the sandwiching roller 31 (holding member 72) has an end in the width direction. It can also be configured to rotate around the position on the side.

Further, a motor shaft 63a of a third drive motor 63 as third drive means (third drive source) is disposed on the other end in the width direction of the frame side rotation shaft 76 rotatably held by the base portion 71 (frame). A rack gear portion 78 that meshes with the pinion gear formed on the frame is installed so as to be rotatable relative to the frame-side rotation shaft 76. The rack gear portion 78 is slidable along the guide rail (not shown) formed on the frame together with the frame-side rotation shaft 76 in the width direction (in the direction of the double arrow in FIG. 4) without rotation. Is held by the frame. Here, like the first and second drive motors 61 and 62, the third drive motor 63 (third drive means) is fixedly installed on the frame of the transport device 30 (image forming apparatus 1).
On the other hand, between the coupling 75 and the post portion on the other end side of the holding member 72, both the rollers 31a and 31b are moved so that the driving roller 31a and the driven roller 31b move in the width direction in conjunction with each other. There is provided a connecting member 73 that is rotatably connected. Specifically, the connecting member 73 is sandwiched by retaining rings 80 installed in grooves formed on the rotation shaft of the drive roller 31a and the rotation shaft of the driven roller 31b, respectively, and the drive roller 31a moves in the width direction. Then, in conjunction with this, the driven roller 31b is also configured to move in the width direction by the same distance.
With such a configuration, when the third driving motor 63 is rotationally driven in the forward and reverse directions, the clamping roller 31 is moved in the width direction (the direction of the double arrow in FIG. Will be moved to). As will be described later, the third drive motor 63 (third drive means) is configured to be able to move the clamping roller 31 in the width direction together with the frame-side rotation shaft 76 based on the detection result of the CIS 36 (second detection means). It has been done.

The nipping roller 31 rotates in an oblique direction together with the holding member 72 on the basis of the detection result of the skew detection sensor 35 (first detection means) while conveying the recording medium P in a nipped state, thereby recording. The positional deviation amount of the medium P is corrected. That is, the sandwiching roller 31 functions as means for performing skew correction (skew correction) of the recording medium P by displacing the recording medium P conveyed in the conveyance path in an oblique direction.
Further, the sandwiching roller 31 moves in the width direction based on the detection result of the CIS 36 (second detection means) while transporting the recording medium P in a sandwiched state, so that the positional displacement amount in the width direction of the recording medium P is reached. Will be corrected. In other words, the pinching roller 31 also functions as means for correcting the lateral registration of the recording medium P by displacing the recording medium P conveyed in the conveyance path in the width direction.

  Here, the third transport roller pair 44 is installed at a position upstream of the sandwiching roller 31 (upstream in the transport direction). The third conveying roller pair 44 is formed so as to be able to convey the recording medium P by rotating in a state in which the recording medium P is sandwiched, and is separated so as to be able to switch between a state in which the recording medium P is sandwiched and a state in which the recording medium P is not sandwiched. It is a pair of conveyance rollers formed so as to be possible. When the recording medium P reaches the position of the sandwiching roller 31 and is sandwiched and transported by the sandwiching roller 31, the third transport roller pair 44 is switched from the state in which the recording medium P is sandwiched to the state in which it is not sandwiched. become.

  In the first embodiment, the nipping roller 31 has a frictional force generated between the nipping roller 31 and the recording medium P when nipping and conveying the recording medium P as compared with that of the third conveying roller pair 44. It is formed to become. Specifically, the friction coefficient (or / and the pressure contact force) of the roller portions of the driving roller 31a and the driven roller 31b in the pinching roller 31 is determined by the driving roller and the driven roller in the third conveying roller pair 44, respectively. It is formed so as to be larger than the friction coefficient (or / and the pressure contact force) of the roller portion. As a result, even if the recording medium P is transported while being sandwiched between the sandwiching roller 31 and the third transporting roller pair 44, the transporting force (holding force) by the sandwiching roller 31 has priority. Therefore, it is possible to suppress a problem that the accuracy of the skew correction and the lateral registration correction of the recording medium P performed by the sandwiching roller 31 is lowered.

The timing roller 45 (fourth conveyance roller pair) is located downstream of the conveyance path with respect to the sandwiching roller 31 (downstream in the conveyance direction) and upstream of the conveyance path with respect to the transfer unit 7 (image forming unit). The pair of transport rollers disposed at the position on the side of the recording medium P is rotated in a state where the recording medium P is nipped, and the recording medium P (the recording medium P after being subjected to the skew correction and the lateral registration correction by the nipping roller 31) Is conveyed toward the image forming unit.
Here, the timing roller 45 is connected to a rotation speed variable drive motor (not shown), and is formed so that the conveyance speed of the recording medium P can be varied. When the timing at which the recording medium P is conveyed to the position of the timing roller 45 is detected by the paper detection sensor 37 (photo sensor) as the third detection means (the recording medium P is conveyed to the position of the timing roller 45). When the state in which the recording medium P is sandwiched by the timing roller 45 is detected), the sandwiching roller 31 is separated so as not to sandwich the recording medium P, and further, based on the detection result (detection timing) of the paper detection sensor 37. Thus, the conveyance speed by the timing roller 45 is varied. That is, the conveyance speed by the timing roller 45 so that the timing at which the recording medium P is conveyed to the transfer unit 7 by the timing roller 45 and the timing at which the image formed on the photosensitive drum 5 reaches the transfer unit 7 are matched. (The conveyance timing of the recording medium P conveyed toward the image forming unit is adjusted). Thereby, the vertical registration correction (position shift correction in the conveyance direction) of the recording medium P can be performed without stopping the conveyance of the recording medium P by the timing roller 45.
Note that the timing roller 45 causes a linear velocity difference with the photosensitive drum 5 immediately after the leading edge of the recording medium P reaches the image forming unit, and thus an image transferred onto the recording medium P is not distorted. Thus, the conveyance speed is varied (the conveyance speed is varied so that the linear velocity ratio with respect to the photosensitive drum 5 is 1).

The skew detection sensor 35 as the first detection means detects the amount of positional deviation (skew amount) in the oblique direction of the recording medium P conveyed in the conveyance path.
Specifically, with reference to FIG. 3, the skew detection sensor 35 is installed on the upstream side of the conveyance path with respect to the sandwiching roller 31 and on the downstream side of the conveyance path with respect to the third conveyance roller pair 44. Yes. The skew detection sensor 35 is two photosensors (consisting of a light emitting element such as an LED and a light receiving element such as a photodiode) installed at positions equidistant from the center position in the width direction. The skew amount β (skew amount) of the recording medium P is detected by detecting the deviation of the timing when the leading end of the recording medium passes. In the first embodiment, based on the detection result of the skew detection sensor 35, skew correction is performed while the recording medium P is sandwiched and conveyed by the sandwiching roller 31.
As a specific example, referring to FIG. 3, the recording medium P is only in the positive direction (the positive direction of the rotation direction) by an angle β with respect to the reference position indicated by the alternate long and short dash line (the normal position without skew). When the skew detection state is detected by the skew detection sensor 35, the control unit sets the positional deviation amount β as a correction amount and moves the sandwiching roller 31 in the reverse direction while sandwiching the recording medium P by the sandwiching roller 31. (The reverse direction of the rotation direction and the clockwise direction in FIG. 3) is rotated by an angle β.

Referring to FIG. 3, the CIS 36 as the second detection means is installed on the downstream side of the conveyance path with respect to the sandwiching roller 31 and on the upstream side of the conveyance path with respect to the timing roller 45. The CIS 36 includes a plurality of photosensors (consisting of a light emitting element such as an LED and a light receiving element such as a photodiode) arranged in the width direction, and is a side end portion on one end side in the width direction of the recording medium P. By detecting the position of Pa (edge portion), the shift amount of the lateral resist is detected. That is, the CIS 36 (second detection means) detects the amount of positional deviation in the width direction of the recording medium P that is transported in the transport path of the transport device 30. Then, based on the detection result of the CIS 36, the lateral registration correction by the sandwiching roller 31 is performed.
In the first embodiment, as shown in FIG. 3, the CIS 36 is installed only on one end in the width direction and the position of the side end Pa on one end in the width direction of the recording medium P is detected. It is also possible to detect the positions of the respective side end portions at both ends in the width direction of the recording medium P by installing over the entire direction.

Based on the detection result of the CIS 36 (second detection means), the recording roller P is moved in the width direction while the recording medium P is sandwiched and transported by the sandwiching roller 31, and the recording medium P transported in the transport path. The positional deviation (lateral registration) in the width direction is corrected.
As a specific example, referring to FIG. 3, the recording medium P is positioned at one end side in the width direction (below the lower side of FIG. When the CIS 36 detects that the position is shifted by the distance α, the control unit sets the position shift amount α as a correction amount, and the recording medium P is sandwiched and conveyed by the sandwiching roller 31. The roller 31 is moved by a distance α to the other end in the width direction (upward in FIG. 3).

As described above, in the first embodiment, the sandwiching roller 31 does not stop the conveyance of the recording medium P, and the detection result of the skew detection sensor 35 (first detection means) in the state of sandwiching the recording medium P. By rotating in the oblique direction based on this, the positional displacement amount in the oblique direction of the recording medium P is corrected, and the width of the recording medium P is moved by moving in the width direction based on the detection result of the CIS 36 (second detection means). This corrects the amount of positional deviation in the direction. That is, in the first embodiment, the skew amount of the recording medium P is detected by the skew detection sensor 35 in a state where the pinching roller 31 is rotated so that the recording medium P can be conveyed, and the recording medium P is detected based on the detection result. Next, the lateral registration correction of the recording medium P is detected by the CIS 36, and the lateral registration correction of the recording medium P is performed based on the detection result.
As a result, the productivity of the apparatus can be significantly improved as compared with the case where the conveyance of the recording medium P is stopped and the skew feeding correction or the lateral registration correction is performed. Further, when skew correction or lateral registration correction is performed, there is no difference in linear velocity between a plurality of roller portions installed in the width direction in the pinching roller 31, so that the recording medium P having a low friction coefficient on thin paper or the surface. Even when the paper is passed, the recording medium P is not bent or slipped.

  Further, in the first embodiment, as described above with reference to FIG. 4, the first drive motor 61 (first drive means), the second drive motor 62 (second drive means), and the third drive motor 63. The (third drive means) is not installed (fixed) on the holding member 72 that holds the pinching roller 31, but is fixedly installed on the frame of the conveying device 30 (image forming apparatus 1). . As a result, the holding member 72 that holds the pinching roller 31 is reduced in weight and size as compared with the case where the driving motor is fixed and installed on the holding member 72. The load generated when the slide movement operation is performed by the motor 63 is reduced, so that the responsiveness of those operations can be improved, and a drive motor with a small drive torque and relatively low power consumption can be selected. Therefore, the skew correction and the lateral registration correction of the recording medium P are performed with higher accuracy without reducing the productivity of the transport device 30 (image forming apparatus 1).

Further, in the first embodiment, after the skew feeding correction / lateral registration correction described above is performed, when the recording medium P is clamped by the timing roller 45, the clamping roller 31 does not clamp the recording medium P. Are spaced apart.
As a result, the conveyance process toward the image forming unit by the timing roller 45 is surely performed, and the operation of the alignment unit 51 for the recording medium P to be conveyed next is quickly prepared.

Hereinafter, an example of the operation of the transport apparatus 30 configured as described above will be described in detail with reference to FIGS. 5 and 6.
5 (A1) to (D1) and FIGS. 6 (A1) to (C1) are top views showing the operation of the conveying device 30 in that order, and FIG. 5 (A2) to (D2). FIGS. 6A2 to 6C2 are side views of the transfer device 30 corresponding to the operations of FIGS. 5A1 to 5D1 and 6A1 to 6C1, respectively.
First, as shown in FIGS. 5A1 and 5A2, the recording medium P fed from the paper feed unit 12 is nipped and conveyed toward the position of the nipping roller 31 by the third conveying roller pair 44. (Conveyance in the direction of white arrow). When the recording medium P reaches the position of the skew detection sensor 35 (first detection means), the skew detection sensor 35 detects the skew amount β of the recording medium P.

  Thereafter, as shown in FIGS. 5B1 and 5B2, immediately before the leading end of the recording medium P reaches the clamping roller 31, the first driving motor 61 rotates the clamping roller 31 (rotation driving in the direction of the arrow in the figure). When the recording medium P is nipped and conveyed by the nipping roller 31, the third conveying roller pair 44 opens the conveying path so that the recording medium P is not nipped (the direction of the solid arrow). ). The timing at which the leading end of the recording medium P reaches the pinching roller 31 is determined by the timing at which the leading end of the recording medium P is detected by the skew detection sensor 35, the conveyance speed of the recording medium P, and the position of the skew detection sensor 35. Is calculated by a calculation unit (control unit) based on the distance from the position to the position of the pinching roller 31.

5 (C1) and 5 (C2), the sandwiching roller 31 is configured to cancel the skew amount β detected by the skew detection sensor 35 while sandwiching / conveying the recording medium P. The drive motor 62 rotates together with the holding member 72 around the shaft 71a. Thus, the skew of the recording medium P is corrected.
Thereafter, as shown in FIGS. 5D1 and 5D2, the recording medium P (which has been skew-corrected) is sandwiched and conveyed by the sandwiching roller 31 and the leading end thereof is CIS 36 (second The position of the detecting means) is reached, and the position shift amount α of the lateral resist is detected at that position.

Then, as shown in FIGS. 6A1 and 6A2, the clamping roller 31 is moved in the width direction by the third drive motor 63 based on the detection result of the CIS 36. That is, the displacement amount of the lateral registration of the recording medium P is detected by the CIS 36, and the sandwiching roller 31 moves in the width direction so as to cancel the displacement amount. Thus, the recording medium P is conveyed toward the timing roller 45 while performing lateral registration correction.
After that, as shown in FIGS. 6B1 and 6B2, when the paper detection sensor 37 detects that the recording medium P has reached the position of the timing roller 45, the recording medium P is sandwiched and conveyed. The clamping roller 31 moves away in a direction (a solid arrow direction) in which the conveyance path is opened and the recording medium P is not clamped.

Thereafter, as shown in FIGS. 6C1 and 6C2, the rotational speed of the timing roller 45 (the conveyance speed of the recording medium P until reaching the transfer unit 7 is adjusted so as to be synchronized with the image on the photosensitive drum 5). ) Is changed, and the recording medium P is conveyed toward the transfer unit 7 (image transfer unit). Thus, the image is transferred to a desired position on the recording medium P.
At this time, the sandwiching roller 31 that has been rotated in the oblique direction and moved in the width direction in order to perform the skew correction and the lateral registration correction is provided in the recording medium P to be transported next, and the second and third. By driving by the drive motors 62 and 63, it is rotated and moved to the reference position (position of FIG. 5 (A1)) as the home position. Further, after the rear end of the recording medium P passes the position of the sandwiching roller 31, the sandwiching roller 31 that has been separated is returned to the contact state (the state of FIG. 5 (A2)).

In the first embodiment, the sandwiching roller 31 rotates in an oblique direction based on the detection result of the skew detection sensor 35 (first detection means) while sandwiching the recording medium P, thereby recording the recording medium. In addition to correcting the positional deviation amount of P in the oblique direction, it operates to correct the positional deviation amount of the recording medium P in the width direction by moving in the width direction based on the detection result of the CIS 36 (second detection means). .
On the other hand, as a modification, the clamping roller 31 is obliquely moved from the first reference position together with the holding member 72 based on the detection result of the skew detection sensor 35 (first detection means) before the recording medium P is clamped. , And after moving in the width direction from the second reference position based on the detection result of the CIS 36 (second detection means), the recording medium P is returned to the first reference position together with the holding member 72 while being sandwiched. By rotating in the diagonal direction, the positional deviation amount of the recording medium P in the diagonal direction is corrected, and by moving in the width direction so as to return to the second reference position, the positional deviation amount of the recording medium P in the width direction is corrected. It may operate to correct.

7 and 8 show an example of the operation of the transport apparatus 30 as such a modification.
7 (A1) to (C1) and FIGS. 8 (A1) to (B1) are top views showing the operation of the conveying device 30 in that order, and FIG. 7 (A2) to (C2). FIGS. 8A2 to 8B2 are side views of the transfer device 30 corresponding to the operations of FIGS. 7A1 to 7C1 and 8A1 to 8B1, respectively.
Referring to FIGS. 7A1 and 7A2 and the like, in the transport apparatus 30 as a modified example, the CIS 36 as the second detection means is on the upstream side of the skew detection sensor 35 and the third transport roller pair 44 Except for the point installed on the downstream side, the configuration is almost the same as that of the transfer device 30 in the first embodiment.

First, as shown in FIGS. 7A1 and 7A2, the recording medium P fed from the paper feeding unit 12 is nipped and conveyed toward the position of the nipping roller 31 by the third conveying roller pair 44. (Conveyance in the direction of white arrow). At this time, the pinching roller 31 is positioned at the first reference position (a normal position corresponding to the recording medium P without skew) by the driving of the second drive motor 62, and the third drive. By driving the motor 63, the position in the width direction is at the second reference position (a normal position corresponding to the recording medium P with no lateral registration misalignment).
Then, when the recording medium P reaches the position of the CIS 36 (second detection means), the lateral registration positional displacement amount α of the recording medium P is detected by the CIS 36. Further, when the recording medium P reaches the position of the skew detection sensor 35 (first detection means), the skew detection sensor 35 detects the skew amount β of the recording medium P. Note that the amount of positional deviation detected directly by the CIS 36 is in a state where the recording medium P is skewed, so that the positional deviation is detected from the detection result detected by the skew detection sensor 35 and the position of the CIS 36. Based on the distance to the position of the row detection sensor 35, etc., the position registration amount α of the lateral registration when there is no skew is obtained by the calculation unit (control unit).

Thereafter, as shown in FIGS. 7B1 and 7B2, the sandwiching roller 31 is shifted by the angle β around the shaft portion 71a in the same inclination direction in accordance with the skew amount β detected by the skew detection sensor 35. While rotating from the first reference position, it shifts from the second reference position by the distance α in the same width direction in accordance with the positional deviation amount α detected by the CIS 36.
Then, as shown in FIGS. 7 (C1) and (C2), immediately before the leading end of the recording medium P reaches the nipping roller 31, the nipping roller 31 is driven to rotate by driving by the first driving motor 61 (in the direction of the arrow in the figure). When the recording medium P is sandwiched and transported by the sandwiching roller 31, the third transport roller pair 44 opens the transport path and does not sandwich the recording medium P (in the direction of the solid arrow). To move away. Note that the timing at which the leading end of the recording medium P reaches the pinching roller 31 is the timing at which the leading end of the recording medium P is detected by the skew detection sensor 35 or the CIS 36, the conveyance speed of the recording medium P, and the skew detection sensor 35. Or the distance from the position of the CIS 36 to the position of the pinching roller 31, etc.

Then, as shown in FIGS. 8A1 and 8A2, the sandwiching roller 31 is configured to cancel the skew amount β detected by the skew detection sensor 35 while sandwiching and transporting the recording medium P. The drive motor 62 is driven to rotate together with the holding member 72 so as to return to the first reference position around the shaft portion 71a, and the third drive motor 63 is driven so as to cancel the positional deviation amount α detected by the CIS 36. To move in the width direction so as to return to the second reference position. In this way, the recording medium P is conveyed toward the timing roller 45 while performing skew feeding correction and lateral registration correction.
Thereafter, as shown in FIGS. 8B1 and 8B2, when the paper detection sensor 37 detects that the recording medium P has reached the position of the timing roller 45, the recording medium P is held and conveyed. The clamping roller 31 moves away in a direction (a solid arrow direction) in which the conveyance path is opened and the recording medium P is not clamped.

Thereafter, the rotational speed of the timing roller 45 (the conveyance speed of the recording medium P until reaching the transfer unit 7) is varied so that the timing is synchronized with the image on the photosensitive drum 5, and the recording medium P is transferred to the transfer unit 7 ( It is conveyed toward the image transfer unit. Thus, the image is transferred to a desired position on the recording medium P.
At this time, the nipping roller 31 is driven by the second and third drive motors 62 and 63 in preparation for the skew correction and the lateral registration correction of the recording medium P to be transported next. Will be located. Then, after the rear end of the recording medium P passes through the position of the sandwiching roller 31, the sandwiching roller 31 that has been separated is returned to the contact state (the state of FIG. 7 (A2)).
Also in the transfer apparatus 30 as such a modification, the same effect as that of the first embodiment can be obtained.

  As described above, in the first embodiment, the recording medium is held by the nipping roller 31 by the plurality of driving motors 61 to 63 (driving means) configured not to be installed on the holding member 72 that holds the nipping roller 31. While transporting while holding P, the positional displacement amount in the oblique direction of the recording medium P is corrected and the positional displacement amount in the width direction of the recording medium P is corrected. As a result, the skew correction and the lateral registration correction of the recording medium P can be performed with high accuracy without reducing the productivity of the transport device 30 (image forming apparatus 1).

Embodiment 2. FIG.
A second embodiment of the present invention will be described in detail with reference to FIGS.
FIG. 9 is a configuration diagram illustrating a main part of the transfer device 30 according to the second embodiment. In particular, FIG. 9A is a side view illustrating the main part of the transfer device 30, and FIG. FIG. 3 is a schematic top view showing a main part of the transport device 30. FIG. 10 is a configuration diagram showing the coupling 75 installed in the transport device 30 of FIG.
The conveying device 30 according to the second embodiment mainly uses a two-stage spline coupling as a coupling 75 interposed between the frame-side rotating shaft 76 and the rotating shaft of the driving roller 31a, and driving. The point that the roller 31a is installed below the driven roller 31b and the mechanism for performing skew feeding correction and lateral registration correction are different from those of the first embodiment.

  Similarly to the first embodiment, the conveying device 30 according to the second embodiment also has a third conveying roller pair 44 and a skew detection sensor 35 (first detecting means) along the linear conveying path of the recording medium P. ), A sandwiching roller 31, a CIS 36 (second detection means), a timing roller 45, and a paper detection sensor 37 (third detection means). Also in the second embodiment, as in the first embodiment, the nipping roller 31 (consisting of the driving roller 31a and the driven roller 31b) held rotatably by the holding member 72 is recorded. It is configured to function as an alignment unit 51 for performing the alignment operation between the skew correction and the lateral registration correction while conveying the medium P.

Here, as shown in FIG. 9, in the conveying device 30 (alignment unit 51) according to the second embodiment, the driving roller 31a is installed below and the driven roller 31b is installed above the clamping roller 31. .
In the second embodiment, the relay frame 92 is interposed between the base portion 71 (frame) and the holding member 72 (a frame body that rotatably holds the pinching roller 31). The relay frame 92 holds the holding member 72 movably in the width direction (the left-right direction in FIG. 9), and is rotatably held by the base portion 71 (frame). The holding member 72 is indirectly supported so as to be rotatable with respect to the base portion 71 (frame) via the relay frame 92.
Further, in the second embodiment, the first drive motor 61 as the first drive means (first drive source) is applied to the base portion 71 (frame) so as to transmit the rotational drive force to the frame-side rotary shaft 76. It is fixed and installed by screw fastening. The third drive motor 63 as third drive means (third drive source) is fixed to the relay frame 92 by screw fastening or the like so as to move the holding member 72 in the width direction. The second drive motor 62 as the second drive means (second drive source) is fixed to the base portion 71 (frame) by screw fastening or the like so as to rotate the relay frame 92.

Specifically, referring to FIG. 9, relay frame 92 is rotatable about shaft portion 71 a with respect to base portion 71 that functions as a part of the frame of transport device 30 (image forming apparatus 1). It is supported. A gear portion 93 is formed on one end side in the width direction of the relay frame 92, and the gear portion 93 meshes with a drive gear installed on the motor shaft of the second drive motor 62. On the relay frame 92, a holding member 72 on which the clamping roller 31 is installed is held.
With such a configuration, the relay frame 92 is rotated in the forward / reverse direction (clockwise / counterclockwise in FIG. 9B) about the shaft portion 71a by the forward / reverse rotation of the second drive motor 62. ).

At the bottom of the holding member 72, two long holes 72c (slide guides) whose longitudinal direction is the width direction are arranged in parallel at different positions in the width direction. Then, two projections 92a (boss portions) formed so as to stand on the relay frame 92 are fitted in these elongated holes 72c, respectively. A rack gear 100 is formed on the side of the holding member 72 so as to extend in the width direction, and the rack gear 100 is a motor of a third drive motor 63 (fixed on the relay frame 92). It meshes with a pinion gear installed on the shaft.
With such a configuration, the holding member 72 is bidirectional on the relay frame 92 along the longitudinal direction of the elongated hole 72c by the rotational drive in the forward and reverse directions of the third drive motor 63 (the lateral direction in FIG. 9). ) Will slide.

A first drive motor 61 is fixed to a side plate of the base portion 71 (frame). The frame side rotation shaft 76 may be a motor shaft of the first drive motor 61 or may be connected so as to be coaxial with the motor shaft of the first drive motor 61. The frame-side rotating shaft 76 is connected to the rotating shaft of the driving roller 31a via a coupling 75 (two-stage spline coupling) described later.
With such a configuration, the rotational driving force is transmitted to the driving roller 31a by the rotational driving of the first driving motor 61 in a predetermined direction, and the clamping roller 31 is rotationally driven.

In the transport device 30 according to the second embodiment, the recording medium is also used by the sandwiching roller 31 in the same manner as that described with reference to FIGS. 5 and 6 (or FIGS. 7 and 8) in the first embodiment. The skew correction and the lateral registration correction are performed while conveying P.
Thus, in the second embodiment, the first drive motor 61 (first drive means), the second drive motor 62 (second drive means), and the third drive motor 63 (third drive means) are nipped. The two drive motors 61 and 62 are not fixed and installed on the holding member 72 that holds the roller 31, and are fixed and installed on the frame 71 of the transport device 30 (image forming apparatus 1), and one drive motor 63 is relayed. The frame 92 is fixed and installed. As a result, the holding member 72 that holds the pinching roller 31 is reduced in weight and size as compared with the case where the driving motor is fixed and installed on the holding member 72. The load generated when the slide movement operation is performed by the motor 63 is reduced, so that the responsiveness of those operations can be improved, and a drive motor with a small drive torque and relatively low power consumption can be selected. Therefore, the skew correction and the lateral registration correction of the recording medium P are performed with higher accuracy without reducing the productivity of the transport device 30 (image forming apparatus 1).

Here, as shown in FIG. 10A, in the second embodiment, the rotation shaft of the drive roller 31a and the frame-side rotation shaft 76 held by the base portion 71 (frame) are interposed. As the coupling 75, a two-stage spline coupling is used.
Specifically, the coupling 75 (two-stage spline coupling) is installed on the first external gear 81 and the frame-side rotating shaft 76 installed on the rotating shaft of the driving roller 31a with reference to FIG. The second external gear 82, the drive transmission member 83 (cylindrical member) formed with the internal gear 83a meshing with the first external gear 81 and the second external gear 82, and the drive transmission member 83 rotate to transmit the drive. The member 83 includes a restricting member 85 that restricts the movement of the member 83 in the width direction.

  Each of the first external gear 81 and the second external gear 82 is formed in a substantially crown shape so that the size in the pitch circle direction gradually increases from both ends in the width direction toward the center in the width direction. With this configuration, the shaft deflection angle is absorbed at two locations, the position where the first external gear 81 and the internal gear 83a mesh with each other, and the position where the second external gear 82 and the internal gear 83a mesh with each other. Will be. That is, even if the shaft center shift occurs between the rotation shaft of the drive roller 31a and the frame-side rotation shaft 76, the drive transmission member 83 on which the internal gear 83a is formed tilts (swings) accordingly. Thus, the axial misalignment is absorbed. Therefore, even when the rotation shaft of the driving roller 31a and the frame-side rotation shaft 76 are not on the same straight line, an axial reaction force is not generated and an angular velocity is not changed (a rotation transmission error is generated). The rotation driving force can be transmitted by absorbing the axial misalignment.

Here, in the second embodiment, as shown in FIG. 10 (A), a protrusion 83b (head portion) is provided on one end side in the width direction of the drive transmission member 83 so as to stand up from the outer peripheral portion. The regulating member 85 (guide member) is formed with a substantially U-shaped inner wall portion so that the protruding portion 83b of the drive transmission member 83 faces with a gap. The drive transmission member 83 swings between the inner wall of the restricting member 85 and the protrusion 83b of the drive transmission member 83 to absorb sufficient gaps (axial misalignment) in the width direction (thrust direction) and the radial direction. Sometimes, the gap is sufficient to prevent the drive transmission member 83 from interfering with the protrusion 83b.
With such a configuration, the driving roller 31a (holding member 72) is removed from the coupling 75 at the time of maintenance, manufacturing, and the like, while preventing the problem that the restricting member 85 hinders the rotation operation and swinging operation of the drive transmission member 83. It is possible to prevent a problem that the drive transmission member 83 falls off in the detached state (can be held on the frame side rotating shaft 76 side).

  The regulating member 85 has an inner diameter portion that is larger than the shaft diameter of the frame-side rotating shaft 76 and is installed so as to be movable in the width direction (thrust direction) with respect to the frame-side rotating shaft 76. The regulating member 85 is brought into contact with the rim portion 82a of the second external gear 82 by a compression spring 84 (one end side is in contact with the regulating member 85) held at one end side by the spring holding portion 86. It is energized.

As a result, the urging force of the compression spring 84 is not transmitted to the frame-side rotating shaft 76, and the position of the drive transmission member 83 in the width direction is also controlled by the regulating member 85 that is positioned in the width direction by the urging force of the compression spring 84. Being regulated, it is possible to reliably absorb the axial misalignment of both rotating shafts.
When the drive roller 31a (holding member 72) is attached to the coupling 75 from the state where the drive roller 31a (holding member 72) is removed from the coupling 75 during maintenance or manufacturing, the first external gear 81 is moved. Even if the teeth collide with the teeth of the internal gear 83 a and the drive transmission member 83 is pushed, the drive transmission member 83 moves to the right in FIG. 10 so as to resist the urging force of the compression spring 84 together with the regulating member 85. Since the first external gear 81 and the internal gear 83a mesh with each other, it is possible to reduce a problem that the first external gear 81 and the internal gear 83a are damaged.
Further, in the second embodiment, since the restricting member 85 is configured to rotate together with the drive transmission member 83 (and the external gears 81 and 82), the restricting member 85 is fixed to the device without rotation. Compared to the case, it is possible to reliably reduce the problem that the regulating member 85 slides on the drive transmission member 83 and the members 83 and 85 are worn.

In the second embodiment, the first external gear 81 and the second external gear 82 are formed to have the same number of teeth and the same tooth shape, and the drive gear 83 has two internal gears 83a. It is formed with the same number of teeth and tooth shape in the width direction so as to mesh with the external gears 81 and 82.
On the other hand, the drive transmission member 83 can also be formed so that the internal gear 83a is formed only in the portions that mesh with the two external gears 81 and 82, respectively. In this case, the internal gear 83a divided into two parts is formed so that the phases of the respective teeth coincide with each other.

  Further, in the second embodiment, the first external gear 81 is formed in a tapered shape so that the teeth at the width direction front end portion (the right end portion in FIG. 10) are reduced in tooth thickness and tooth depth. Has been. Accordingly, when the drive roller 31a (holding member 72) is mounted on the coupling 75 from the state where the drive roller 31a (holding member 72) is removed from the coupling 75 during maintenance or manufacturing, the first external gear 81 is mounted. And the internal gear 83a are easily meshed with each other. Specifically, when the drive roller 31a (holding member 72) is mounted on the coupling 75 from a state in which the drive roller 31a (holding member 72) is removed from the coupling 75, the teeth of the first external gear 81 are in contact with the internal gear 83a. Even if it is likely to collide with teeth, the internal gear 83a (drive transmission member 83) is connected to the internal gear 83a and the second external gear with respect to the first external gear 81 by the tapered portion formed at the tip of the first external gear 81. The internal gear 83a and the second external gear 82 mesh with each other at the correct meshing phase, for example, by changing the posture in the rotational direction by the amount of backlash with the gear 82.

  In the second embodiment, as described above, the first drive roller 31a (clamping roller 31) is held together with the holding member 72 by the third drive motor 63 (third drive means) fixed and installed on the relay frame 92. Will move in the width direction (the left-right direction in FIG. 9), but even if the first drive roller 31a (clamping roller 31) moves to the maximum in the width direction, the first external gear from the coupling 75 The configuration is such that 81 does not fall off or the first external gear 81 and the second external gear 82 interfere with each other. Specifically, during the lateral registration correction, even if the first drive roller 31a moves to the left in FIG. 9 as much as possible, the first external gear 81 does not fall off the coupling 75 (internal gear 83a), and the first drive In order to prevent the first external gear 81 and the second external gear 82 from interfering with each other even when the roller 31a moves to the right in FIG. 9, the coupling 75 (the first external gear 81, the second external gear 82, the internal The length in the width direction of the gear 83a) and the positional relationship are set.

  In addition, with reference to the A portion surrounded by the solid line in FIG. 10B, in the second embodiment, the tip end portion of the projection 83b (head portion) of the drive transmission member 83 is substantially hemispherical (convex spherical). ) And the inner wall portion of the restricting member 85 can be formed in a substantially hemispherical shape (concave spherical shape) so as to match the shape. By configuring in this way, it is possible to reduce the frictional resistance when the protruding portion 83b comes into contact with the inner wall portion of the regulating member 85.

  As described above, also in the second embodiment, as in the first embodiment, a plurality of drive motors 61 to 63 (not shown) installed on the holding member 72 that holds the pinching roller 31 ( The drive means) corrects the positional displacement amount of the recording medium P in the oblique direction and the positional displacement amount of the recording medium P in the width direction while conveying the recording medium P while being sandwiched by the sandwiching rollers 31. As a result, the skew correction and the lateral registration correction of the recording medium P can be performed with high accuracy without reducing the productivity of the transport device 30 (image forming apparatus 1).

In the second embodiment, in the conveying device 30 in which the holding member 72 that holds the sandwiching roller 31 (the driving roller 31a and the driven roller 31b) so as not to move in the width direction is installed, the rotation shaft of the driving roller 31a A two-stage spline coupling was used as the coupling 75 interposed between the frame side rotation shaft 76 and the frame side rotation shaft 76.
On the other hand, as in the first embodiment, in the conveying device 30 in which the holding member 72 that holds the clamping roller 31 (the driving roller 31a and the driven roller 31b) so as to be movable in the width direction is installed, the driving roller A two-stage spline coupling can also be used as the coupling 75 interposed between the rotating shaft 31a and the frame-side rotating shaft 76. In that case, a means for limiting the positional relationship (distance) in the width direction between the first external gear 81 and the second external gear 82 in the coupling 75 is not changed.

Embodiment 3 FIG.
A third embodiment of the present invention will be described in detail with reference to FIG.
FIG. 11 is a configuration diagram illustrating a main part of the transfer device 30 according to the third embodiment, and corresponds to FIG. 9 according to the second embodiment. FIG. 12 is a configuration diagram showing a main part of a transport apparatus 30 as a modification to the transport apparatus 30 of FIG. 11, and corresponds to FIG. 9 in the second embodiment.
The transport apparatus according to the third embodiment is mainly configured as one drive means (drive source) in which the second drive means (second drive source) and the third drive means (third drive source) are common. The point and the mechanism for performing the skew correction and the lateral registration correction are different from those of the second embodiment.

  The transport device 30 in the third embodiment also has a third transport roller pair 44, a skew detection sensor 35 (first detection means) along the straight transport path of the recording medium P, as in the above embodiments. ), A sandwiching roller 31, a CIS 36 (second detection means), a timing roller 45, and a paper detection sensor 37 (third detection means). Also in the third embodiment, as in the above-described embodiments, the sandwiching roller 31 (consisting of the driving roller 31a and the driven roller 31b) that is rotatably held by the holding member 72 is recorded. It is configured to function as an alignment unit 51 for performing the alignment operation between the skew correction and the lateral registration correction while conveying the medium P.

Further, as shown in FIG. 11, the conveying device 30 (alignment unit 51) in the third embodiment also has a driving roller 31a and a driven roller 31b below the nipping roller 31, as in the second embodiment. It is installed above.
Also in the third embodiment, a relay frame 92 is interposed between the base portion 71 (frame) and the holding member 72 as in the second embodiment. The relay frame 92 holds the holding member 72 movably in the width direction (the left-right direction in FIG. 11) and is rotatably held by the base portion 71 (frame).
Furthermore, also in the third embodiment, the first drive motor 61 as the first drive means (first drive source) is configured to transmit the rotational drive force to the frame-side rotary shaft 76 so that the base portion 71 (frame). It is fixed by screw fastening etc. In the third embodiment, as in the second embodiment, a two-stage spline coupling is used as the coupling 75 interposed between the rotating shaft of the drive roller 31a and the frame-side rotating shaft 76. It has been.

  Here, as shown in FIG. 11, in the conveyance device 30 (alignment unit 51) according to the third embodiment, the second driving means for performing skew feeding correction and the third driving means for performing lateral registration correction. Are configured as a drive motor 90 (correction drive motor) as one common drive means. The correction drive motor 90 is fixed to the relay frame 92 by screw fastening or the like. Further, the correction drive motor 90 (one common drive means) is configured to transmit the driving force via the first one-way clutch 87 as the first switching means to move the holding member 72 in the width direction. In addition, the relay frame 92 is rotated by transmitting a driving force via a second one-way clutch 88 as a second switching means.

Then, transmission of driving force by the first one-way clutch 87 (first switching means) and transmission of driving force by the second one-way clutch 88 (second switching means) are performed at different timings.
Specifically, the first one-way clutch 87 (first switching means) is a one-way clutch (one-way clutch) that can rotate in the forward direction, and the second one-way clutch 88 (second switching means) can rotate in the reverse direction. The correction drive motor 90 is a drive motor that can rotate in the forward and reverse directions. Then, by switching the rotation direction of the correction drive motor 90, transmission of driving force to the holding member 72 by the first one-way clutch 87 (first switching means) and by the second one-way clutch 88 (second switching means). The driving force is transmitted to the relay frame 92 (or the base portion 71) at different timings (skew correction and lateral registration correction are performed at different timings).

Specifically, referring to FIG. 11, relay frame 92 is rotatable about shaft portion 71 a with respect to base portion 71 that functions as a part of the frame of transport device 30 (image forming apparatus 1). It is supported. On the relay frame 92, a holding member 72 on which the clamping roller 31 is installed is held.
At the bottom of the holding member 72, two long holes 72c (slide guides) whose longitudinal direction is the width direction are arranged in parallel at different positions in the width direction. Then, two projections 92a (boss portions) formed so as to stand on the relay frame 92 are fitted in these elongated holes 72c, respectively.

The correction drive motor 90 is fixed on the relay frame 92, and two one-way clutches 87 and 88 having different rotation directions are connected to the motor shaft.
The first one-way clutch 87 is connected to one end side of the link 89 at a position away from the rotation center (motor shaft) in the radial direction. The other end side of the link 89 is connected to the holding member 72.
With such a configuration, the first one-way clutch 87 is also rotated in the forward direction (clockwise) by the rotational drive of the correction drive motor 90 in the forward direction (clockwise), and the holding member 72 is long on the relay frame 92. It slides in both directions (the left-right direction in FIG. 11) along the longitudinal direction of the hole 72c. Here, when the first one-way clutch 87 makes one rotation in the forward direction, the holding member 72 slides in both directions and returns to the original position. That is, one forward rotation of the first one-way clutch 87 corresponds to one cycle of the sliding movement of the holding member 72.
When the correction drive motor 90 is driven to rotate in the reverse direction (counterclockwise), the first one-way clutch 87 is idled and the holding member 72 is not slid.

The outer periphery of the second one-way clutch 88 has a cam shape, and the guide portion 93 is energized by a tension spring 94 (one end side is connected to the base portion 71 and the other end side is connected to the relay frame 92). Abut. The guide portion 93 is a substantially columnar member and is installed so as to stand on the base portion 71.
With such a configuration, the second one-way clutch 88 is also rotated in the reverse direction (counterclockwise) by the reverse rotation (counterclockwise) of the correction drive motor 90, so that the relay frame 92 moves the shaft portion 71a. It rotates about the center in the forward and reverse directions (clockwise and counterclockwise in FIG. 11B). Here, when the second one-way clutch 88 rotates once in the reverse direction, the relay frame 92 rotates in the forward and reverse directions and returns to the original position. That is, one reverse rotation of the second one-way clutch 88 corresponds to one rotation cycle of the relay frame 92.
When the correction drive motor 90 is rotationally driven in the forward direction (clockwise), the second one-way clutch 88 is idled and the relay frame 92 is not rotated.

  In the transport device 30 according to the third embodiment, the recording medium is also used by the sandwiching roller 31 in the same manner as that described in the first embodiment with reference to FIGS. 5 and 6 (or FIGS. 7 and 8). The skew correction and the lateral registration correction are performed while conveying P.

In particular, in the third embodiment, skew correction and lateral registration correction are performed at different timings using one correction drive motor 90.
As a specific example of the correction operation, the detection result detected by the skew detection sensor 35 (first detection means) and the CIS 36 (second detection) before the recording medium P reaches the position of the sandwiching roller 31 (alignment unit 51). Based on the detection result detected by the means, the correction drive motor 90 is sequentially driven by the necessary rotation amounts in the forward direction and the reverse direction. Then, while the recording medium P is sandwiched and conveyed by the sandwiching roller 31, the correction drive motor 90 is sequentially moved in the forward direction and the reverse direction so that the rotation amount of each one-way clutch 87, 88 reaches one rotation. To drive.
As another specific example of the correction operation, based on the detection result detected by the skew detection sensor 35 (first detection means) before the recording medium P reaches the position of the sandwiching roller 31 (alignment unit 51). Then, the correction drive motor 90 is driven in the reverse direction by a necessary amount of rotation. Then, while the recording medium P is sandwiched and conveyed by the sandwiching roller 31, the correction drive motor 90 is sequentially driven in the reverse direction so that the rotation amount of the second one-way clutch 88 reaches one rotation, and thereafter Based on the detection result detected by the CIS 36 (second detection means), the correction drive motor 90 is driven in the forward direction by a necessary amount of rotation. Then, after the recording medium P passes through the position of the pinching roller 31, the correction driving motor 90 is driven in the forward direction so that the rotation amount of the first one-way clutch 87 reaches one rotation, so that the pinching roller 31 is In preparation for the correction operation of the recording medium P which is returned to the original position (slide position and rotation position) and then transported.

Thus, in the third embodiment, the first drive motor 61 (first drive means) and the correction drive motor 90 (one drive means in which the second drive means and the third drive means are made common) and However, it is not fixed / installed on the holding member 72 that holds the sandwiching roller 31, and one drive motor 61 is fixed / installed on the frame 71 of the transport device 30 (image forming apparatus 1), and one drive motor 90 is provided. It is fixed and installed on the relay frame 92. As a result, the holding member 72 that holds the pinching roller 31 is reduced in weight and size as compared with the case where the driving motor is fixed and installed on the holding member 72. The load generated when the slide movement operation is performed by the motor 63 is reduced, so that the responsiveness of those operations can be improved, and a drive motor with a small drive torque and relatively low power consumption can be selected. Therefore, the skew correction and the lateral registration correction of the recording medium P are performed with higher accuracy without reducing the productivity of the transport device 30 (image forming apparatus 1).
In particular, the third embodiment is configured such that skew correction and lateral registration correction can be performed by a single drive motor 90, so that the transport device 30 (image forming apparatus 1) can be reduced in weight and size. Cost can be reduced.

Here, the conveyance apparatus 30 as a modification is demonstrated using FIG.
Unlike the one shown in FIG. 11, the conveying device 30 shown in FIG. 12 has two one-way clutches in which the drive gear installed on the motor shaft of the correction drive motor 90 fixed to the relay frame 92 has different rotation directions. The gears formed on the outer peripheries of 91 and 96 are engaged with each other. One end sides of the links 89 and 95 are connected to the two one-way clutches 91 and 96, respectively, at positions away from the rotation shaft in the radial direction.
The other end side of the first link 89 connected to the first one-way clutch 91 is connected to the holding member 72. Then, the first one-way clutch 91 rotates in the forward direction (clockwise) by the counterclockwise rotation drive of the correction drive motor 90, and the holding member 72 slides on the relay frame 92.
Two boss portions installed on the other end side of the second link 95 connected to the second one-way clutch 96 are two guide rails 97 formed on the base portion 71 (in a direction perpendicular to the width direction). Are fitted to each other. The first one-way clutch 91 is rotated in the reverse direction (counterclockwise) by the clockwise driving of the correction drive motor 90, and the second link 95 is moved along the guide rail 97. The frame 92 rotates around the shaft portion 71a.
Even when the transport device 30 is configured in this manner, the same effects of the invention as in the third embodiment can be obtained.

  As described above, also in the third embodiment, a plurality of drive motors 61 and 90 (not shown) which are configured not to be installed on the holding member 72 that holds the holding roller 31, as in the above embodiments. The drive means) corrects the positional displacement amount of the recording medium P in the oblique direction and the positional displacement amount of the recording medium P in the width direction while conveying the recording medium P while being sandwiched by the sandwiching rollers 31. As a result, the skew correction and the lateral registration correction of the recording medium P can be performed with high accuracy without reducing the productivity of the transport device 30 (image forming apparatus 1).

  In the third embodiment, the drive from the correction drive motor 90 is performed using the first one-way clutch 87 as the first switching means for transmitting or interrupting the drive force from the correction drive motor 90. A second one-way clutch 88 is used as a second switching means for transmitting and interrupting force. However, these switching means are not limited to the one-way clutch, and an electromagnetic clutch or the like can be used, or another switching mechanism can be used.

In each of the above-described embodiments, the present invention is applied to the conveyance device 30 installed in the monochrome image forming apparatus 1. However, the present invention is naturally applied to the conveyance device installed in the color image forming apparatus. The invention can be applied.
In each of the above embodiments, the present invention is applied to the conveyance device 30 installed in the electrophotographic image forming apparatus 1. However, the application of the present invention is not limited to this, and other methods. Even if it is a transport apparatus installed in the image forming apparatus (for example, an inkjet image forming apparatus or an offset printing machine), if it is a transport apparatus that performs skew correction and lateral registration correction, Of course, the present invention can also be applied to all of these transport apparatuses.
Even in those cases, the same effects as those of the above-described embodiments can be obtained.

Further, in each of the above embodiments, the present invention is applied to the transport device 30 disposed at a position upstream of the timing roller 45 in the transport direction, but the application of the present invention is limited to this. Of course, the present invention can be applied to all of the transfer devices as long as the transfer device is installed in other positions as long as it performs skew feeding correction and lateral registration correction. Can do.
Moreover, in each said embodiment, although this invention was applied with respect to the conveying apparatus 30 in which two conveyance paths merge in the junction part X, the conveyance apparatus in which three or more conveyance paths merge in the junction part X, Naturally, the present invention can also be applied to a transport apparatus that is formed of only one transport path without the junction X.
Further, in each of the above embodiments, the present invention is applied to the conveyance device 30 in which the three paper feeding units 12 to 14 are installed, but the conveyance in which two or less or four or more paper feeding units are installed. Of course, the present invention can also be applied to an apparatus.
Even in those cases, the same effects as those of the above-described embodiments can be obtained.

  It should be noted that the present invention is not limited to the above-described embodiments, and within the scope of the technical idea of the present invention, the embodiments can be modified as appropriate in addition to those suggested in the embodiments. Is clear. In addition, the number, position, shape, and the like of the constituent members are not limited to the above embodiments, and can be set to a number, position, shape, and the like that are suitable for carrying out the present invention.

  In the present application, the “width direction” is defined as a direction orthogonal to the conveyance direction of the recording medium.

1 image forming apparatus (apparatus body),
30 transport device,
31 Nipping roller (horizontal registration / skew correction roller),
31a Driving roller,
31b driven roller,
35 Skew detection sensor (first detection means),
36 CIS (second detection means),
37 Paper detection sensor (third detection means),
44 Third conveying roller pair,
45 Timing roller (conveying roller pair),
51 alignment section,
61 1st drive motor (1st drive means),
62 second drive motor (second drive means),
63 third drive motor (third drive means),
71 Base part (frame),
72 holding members,
73 connecting member,
75 coupling,
76 Frame side rotation axis,
P Recording medium (sheet).

JP 2008-50069 A JP 2008-239348 A

Claims (12)

A transport device for transporting a recording medium in a transport path,
A nipping roller that is rotationally driven by the first driving means and conveys the recording medium in a nipped state;
A holding member that rotatably holds the clamping roller and is rotatably supported with respect to the frame of the apparatus;
First detection means for detecting the amount of positional deviation in the oblique direction of the recording medium conveyed in the conveyance path;
Second detection means for detecting the amount of positional deviation in the width direction of the recording medium conveyed in the conveyance path;
Second driving means configured to be able to rotate the holding member in an oblique direction together with the clamping roller based on a detection result of the first detection means;
Third driving means configured to be able to move the clamping roller in the width direction based on a detection result of the second detection means;
With
A conveying apparatus characterized in that the first driving means, the second driving means and the third driving means are not installed on the holding member. The holding member holds the pinching roller movably in the width direction,
A connecting member that rotatably connects both the rollers such that the driving roller and the driven roller in the clamping roller move in the width direction in conjunction with each other;
A coupling interposed between a rotation shaft of the drive roller and a frame-side rotation shaft held by the frame;
With
The first driving means is fixedly installed on the frame so as to transmit a rotational driving force to the frame-side rotating shaft,
The third driving means is fixedly installed on the frame so as to move the frame side rotation shaft in the width direction,
The transport apparatus according to claim 1, wherein the second driving unit is fixed to the frame so as to rotate the holding member. A coupling interposed between a rotation shaft of the drive roller and a frame-side rotation shaft held by the frame;
A relay frame interposed between the frame and the holding member to hold the holding member movably in the width direction and rotatably held by the frame;
With
The first driving means is fixedly installed on the frame so as to transmit a rotational driving force to the frame-side rotating shaft,
The third driving means is fixedly installed on the relay frame so as to move the holding member in the width direction,
The transport apparatus according to claim 1, wherein the second driving unit is fixed to the frame so as to rotate the relay frame. A coupling interposed between a rotation shaft of the drive roller and a frame-side rotation shaft held by the frame;
A relay frame interposed between the frame and the holding member to hold the holding member movably in the width direction and rotatably held by the frame;
With
The first driving means is fixedly installed on the frame so as to transmit a rotational driving force to the frame-side rotating shaft,
The second driving means and the third driving means are one common driving means fixedly installed on the relay frame, and transmit the driving force through the first switching means to transmit the holding member. Configured to move in the width direction, and configured to transmit the driving force via the second switching means to rotate the relay frame,
The transfer device according to claim 1, wherein the transmission of the driving force by the first switching unit and the transmission of the driving force by the second switching unit are performed at different timings. The first switching means is a one-way clutch that is rotatable in the forward direction,
The second switching means is a one-way clutch that can rotate in the reverse direction,
The common driving means is a driving motor that can rotate in forward and reverse directions, and the driving force is transmitted by the first switching means and the driving force by the second switching means by switching the rotation direction. The transfer device according to claim 4, wherein the transfer is performed at a different timing. A coupling interposed between the rotating shaft of the drive roller and the frame-side rotating shaft held by the frame;
The coupling is
A first external gear installed on the rotation shaft of the drive roller and formed so that the size in the pitch circle direction gradually increases from both widthwise end portions toward the widthwise central portion;
A second external gear installed on the frame-side rotation shaft and formed so that the size in the pitch circle direction gradually increases from both widthwise end portions toward the widthwise central portion;
A drive transmission member formed with an internal gear meshing with the first external gear and the second external gear;
The conveying apparatus according to claim 1, comprising:   The conveyance device according to claim 6, wherein the coupling includes a regulating member that rotates together with the drive transmission member and regulates movement of the drive transmission member in a width direction.   The sandwiching roller rotates in an oblique direction together with the holding member based on a detection result of the first detection unit in a state where the recording medium is sandwiched, thereby correcting a displacement amount of the recording medium in the oblique direction. The position shift amount in the width direction of the recording medium is corrected by moving in the width direction based on the detection result of the second detection means. Conveying device.   The clamping roller rotates in an oblique direction from the first reference position together with the holding member based on the detection result of the first detection means before clamping the recording medium, and based on the detection result of the second detection means. After moving in the width direction from the second reference position, the recording medium is rotated in an oblique direction so as to return to the first reference position together with the holding member while sandwiching the recording medium. The position shift amount in the width direction of the recording medium is corrected by correcting the amount and moving in the width direction so as to return to the second reference position. The conveying apparatus as described. The recording medium is disposed at a position downstream of the conveyance path with respect to the nipping roller, and rotates in a state where the recording medium is nipped, thereby conveying the recording medium toward the image forming unit and increasing the conveyance speed of the recording medium. A pair of transport rollers formed to be variable;
Third detection means for detecting the timing at which the recording medium is conveyed to the position of the conveyance roller pair;
With
The clamping roller corrects the positional deviation in the oblique direction and the width direction of the recording medium conveyed in the conveyance path, and when the recording medium is nipped between the conveyance roller pair, So as not to be pinched,
The conveying device according to any one of claims 1 to 9, wherein the conveying speed of the conveying roller pair is variable based on a detection result of the third detecting unit. A transport roller pair disposed at a position upstream of the transport path with respect to the sandwiching roller and transporting the recording medium toward the sandwiching roller by rotating in a state of sandwiching the recording medium;
The nipping roller is formed so that a frictional force generated between the nipping roller and the recording medium when nipping and conveying the recording medium is larger than that of the conveying roller pair. The conveyance apparatus in any one of Claims 1-10.   An image forming apparatus comprising the transport device according to claim 1.

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