JP2016175729A - Conveyance device and image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem in which it is difficult to perform inclination correction and lateral dislocation correction of a recording medium by accurately moving holding rollers at a high speed when a heavy article is mounted on a holding member holding the holding rollers.SOLUTION: A conveyance device comprises: holding rollers 31 which convey a recording medium in the state of being held; a holding member 72 which holds the holding rollers 31 rotationally, and is configured to be able of reciprocally move in the width direction of the recording medium with respect to a device body and be able to rotate in the inclination direction of the recording medium and the direction opposite to the inclination direction; a first belt drive mechanism 75 which reciprocally moves the holding rollers 31 in the width direction of the recording medium together with the holding member 72 on the basis of the detection result of lateral dislocation detection means; and a second belt drive mechanism 76 which rotates the holding rollers 31 in the inclination direction of the recording medium and the direction opposite to the inclination direction together with the holding member 72 on the basis of the detection result of inclination detection means. The first belt drive mechanism 75 and the second belt drive mechanism 76 are provided on the device body side.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a conveying device that conveys a recording medium, and an image forming apparatus including such a conveying device.

  In an image diameter apparatus such as a copying machine or a printer, a technique for correcting an inclination with respect to a recording medium conveyance direction and a positional deviation (lateral deviation) in a width direction perpendicular to the recording medium conveyance direction is known.

  For example, in Patent Document 1 (Japanese Patent Laid-Open No. 10-67448), a conveyance roll that conveys a recording sheet while sandwiching a recording sheet with respect to a stage member that is rotatably attached to the apparatus main body around a support shaft. A configuration in which the pair is provided so as to be movable in the axial direction is described. In this configuration, when the inclination of the recording sheet is detected by the detection sensor, the inclination is corrected by rotating the stage member around the support shaft in a state where the recording sheet is sandwiched by the pair of conveying rolls. . Further, when a lateral deviation of the recording sheet is detected, the positional deviation in the width direction is corrected by moving the conveyance roll pair in the axial direction while the recording sheet is held.

  By employing the correction mechanism as described above, it is possible to reliably correct the tilt and lateral deviation of the recording medium. However, in the configuration described in Patent Document 1, since a heavy object such as a motor and a driving force transmission mechanism for moving the conveyance roll pair in the axial direction is provided on the stage member, the stage member is moved at high speed and with high accuracy. It was disadvantageous. Therefore, the image forming apparatus that performs printing at high speed may not be able to cope with it. Further, when the stage member is moved at a high speed, a drive source with a large output is required, which causes a problem that the apparatus is increased in size and weight.

  In order to solve the above-described problems, the present invention is a conveyance device that conveys a recording medium, and an inclination detection unit that detects an inclination amount with respect to the conveyance direction of the recording medium, and a position in a width direction orthogonal to the conveyance direction of the recording medium. A lateral deviation detecting means for detecting a deviation amount, a sandwiching roller that conveys the recording medium while sandwiching the recording medium, and rotatably holding the sandwiching roller, and capable of reciprocating in the width direction of the recording medium with respect to the apparatus main body, In addition, the holding member is configured to be rotatable in the tilt direction of the recording medium and in the opposite direction thereof, and the holding roller is reciprocated in the width direction of the recording medium together with the holding member based on the detection result of the lateral deviation detecting means. Based on the detection result of the first belt driving mechanism to be moved and the tilt detecting means, the holding roller and the holding roller are rotated in the tilt direction of the recording medium and in the opposite direction. And a belt drive mechanism, the said first belt drive mechanism and the second belt drive mechanism, characterized in that provided in the apparatus main body.

  In the present invention, since the first belt drive mechanism and the second belt drive mechanism are provided on the apparatus main body side and these are not provided on the holding member, the weight of the structure installed on the holding member can be reduced. This makes it easy to move the holding member at high speed and with high accuracy, and makes it possible to correct the tilt and lateral deviation of the recording medium at high speed and with high accuracy. In addition, a drive source having a relatively small output can be used to drive the holding member, and the apparatus can be reduced in size and weight.

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 which shows the whole structure of a conveying apparatus. It is a top view of a conveying apparatus. It is a front view of a conveying apparatus. It is a top view of a conveying apparatus. It is a front view which shows the structure of the relay support member of a conveying apparatus. It is a figure which shows the movement operation | movement to the width direction of a holding frame. It is a top view which shows rotation operation | movement of a holding frame. It is the schematic which shows the structure of a two-stage spline coupling. It is a figure which shows the structure of the attachment member which has a pair of clamping part, Comprising: (a) is a cross-sectional top view, (b) is a side view of one clamping part, (c) is a side view of the other clamping part. . It is a cross-sectional top view which shows the structure of another attachment member. It is the schematic which shows the correction | amendment operation | movement of a conveying apparatus. It is the schematic which shows the correction | amendment operation | movement of a conveying apparatus. It is a front view which shows the modification of a conveying 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 the image forming apparatus will be described with reference to FIG.
In FIG. 1, reference numeral 1 denotes a copying machine as an image forming apparatus, 2 denotes a document reading unit that optically reads image information of a document D, and 3 denotes a photosensitive member that exposes light L based on the image information read by the document reading unit 2. An exposure unit for irradiating the drum 5, 4 is an image forming unit for forming a toner image (image) on the photosensitive drum 5, and 7 is a transfer for transferring the toner image formed on the photosensitive drum 5 to the recording medium P. Section (image forming section), 10 is a document transport section that transports a set document D to the document reading section 2, and 12 to 14 are sheet feeding sections (sheet feeding) in which a recording medium (sheet) P such as transfer paper is stored. 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 a recording medium P. A transport device 31 that transports along the transport path is connected to the transfer unit 7. Only shows a nip roller that functions as a registration roller (timing roller) for conveying the recording medium P (lateral-inclination correcting roller).

With reference to FIG. 1, an operation during normal image formation in the copying machine 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 electrical signal and then transmitted to the exposure unit 3. Then, exposure light (laser light) L 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 clockwise 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 sandwiching roller 31 functioning as a registration roller in the transfer unit 7 as an image forming unit.

Further, the recording medium P conveyed to the transfer unit 7 is conveyed as follows.
First, as shown in FIG. 2, one of the plurality of paper feeding units 12 to 14 of the copying machine 1 is automatically or manually selected. For example, when the paper feed unit 12 provided in the copier 1 is selected, the uppermost sheet of the recording medium P stored in the paper feed unit 12 is fed by the paper feed roller 41 to the first transport roller. The pair 42 and the second transport roller pair 43 are fed toward the curved transport path where the pair is installed.

  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 copying machine 1 merge), and then the third medium. It passes through the straight conveyance path in which the conveyance roller pair 44 and the alignment unit 51 are installed, and reaches the position of the sandwiching roller 31 that constitutes the alignment unit 51. Then, the tilting and lateral shift correction of the recording medium P is performed by the sandwiching roller 31 constituting the aligning unit 51, and the timing is adjusted in order to align with the image formed on the photosensitive drum 5. It is conveyed toward the transfer unit 7.

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 is fixed is delivered from between the fixing roller 21 and the pressure roller 22 (nip portion), and then discharged from the copying machine 1.
Thus, a series of image forming processes is completed.

  Here, in this embodiment, the conveyance path from the paper feeding unit 12 installed in the copying machine 1 and the conveyance path from the two paper feeding units 13 and 14 installed outside the copying machine 1 merge. As a transport path from the joining section X to the transfer section 7, a linear transport path formed in a substantially linear shape along the transport direction of the recording medium P is provided. This linear transport path is formed by a linear transport guide plate or the like installed so as to sandwich the front and back surfaces of the recording medium P to be transported, and the third transport roller pair 44, CIS (lateral deviation detection means) along the transport direction. ) 36, a skew detection sensor (tilt detection means) 35, and a clamping roller 31 are provided.

  All of the transport roller pairs 42 to 44 (including transport roller pairs not denoted by reference numerals) installed in the transport device 30 including the third transport roller pair 44 and the sandwiching roller 31 are driven by a drive mechanism. It is a roller pair comprising a drive roller that is rotationally driven and a driven roller that is driven to rotate by frictional resistance with the drive roller. The recording medium P is conveyed while being sandwiched between these conveying roller pairs. The sandwiching roller 31 also serves as an alignment unit 51 for performing an alignment operation of inclination correction for correcting the inclination of the recording medium P with respect to the conveyance direction and lateral deviation correction for correcting a positional deviation in the width direction orthogonal to the conveyance direction. Function.

  Specifically, as shown in FIG. 3 when the conveying device 30 is viewed from above, the sandwiching roller 31 has an inclination direction of the recording medium P around a support shaft 73 serving as a rotation fulcrum and a direction opposite thereto (in FIG. 3). It is configured to be rotatable in the direction of the broken line arrow W and to be movable in the width direction of the recording medium P (the direction of the broken line arrow S in FIG. 3). The sandwiching roller 31 rotates around the support shaft 73 based on the detection result of the skew detection sensor 35 to correct the inclination of the recording medium P, or the width direction of the recording medium P based on the detection result of the CIS 36. To shift the lateral displacement of the recording medium P.

  The skew detection sensor 35 detects a positional deviation amount (skew amount) in the tilt direction of the recording medium P conveyed in the conveyance path. Specifically, as shown in FIG. 3, the skew detection sensor 35 is arranged 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 (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 inclination amount (skew amount) β of the recording medium P is detected by detecting the deviation of the passing timing. In the present embodiment, based on the detection result of the skew detection sensor 35, tilt correction is performed while the recording medium P is sandwiched and conveyed by the sandwiching roller 31.

  For example, as shown in FIG. 3, the recording medium P is in the positive direction (in the rotational direction) with respect to the reference position Y indicated by the alternate long and short dash line (the reference position at the end in the width direction of the recording medium P conveyed without tilting or lateral displacement). When the skew detection sensor 35 detects that the state is inclined by the angle β in the positive direction), the control unit sets the inclination amount β as a correction amount and holds the recording medium P by the holding roller 31. 31 is rotated by an angle β in the reverse direction (the reverse direction of the rotation direction and clockwise in FIG. 3).

  The CIS 36 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. The CIS 36 includes a plurality of photosensors (a light emitting element such as an LED, a light receiving element such as a photodiode, and an imaging lens) arranged in parallel in the width direction. The shift amount in the width direction is detected by detecting the position of the portion Pa (edge portion). Then, based on the detection result of the CIS 36, lateral deviation correction by the clamping roller 31 is performed.

  For example, as shown in FIG. 3, the recording medium P is displaced by a distance α on one end side in the width direction (downward in FIG. 3) with respect to the reference position Y indicated by the alternate long and short dash line. , When detected by the CIS 36, the control unit sets the positional deviation amount α as a correction amount, and the clamping roller 31 is held in the other end in the width direction (upward in FIG. 3) while the recording medium P is clamped and conveyed by the clamping roller 31. Is moved by a distance α.

Next, based on FIGS. 4-11, the structure of the conveying apparatus 30 is demonstrated in detail.
As shown in FIG. 4, the sandwiching roller 31 includes a driving roller 31 b to which a driving force from a motor 61 as a sandwiching roller driving unit is applied, and a driven roller 31 a that is driven and rotated together with the driving roller 31 b. These rollers 31a and 31b are held rotatably around a roller axis by a holding frame 72 as a holding member. The holding frame 72 is formed by forming a sheet metal in a substantially box shape, and the shaft portion of the sandwiching roller 31 is inserted into a hole portion formed in both end portions in the width direction (left-right direction in FIG. 4) via a bearing. Has been inserted.

  The holding frame 72 is supported by a base frame 71 as a fixed support fixed to a main body frame 70 constituting a frame on the apparatus main body side, and a movable frame 81 as a movable support provided on the base frame 71. Yes.

  As shown in FIG. 5, the holding frame 72 is installed on the upper surface of the base frame 71 via a free bearing (ball transfer) 95 as a relay support member. As a result, the holding frame 72 is configured to be movable relative to the base frame 71 in the front / rear / left / right (substantially horizontal) direction along the upper surface thereof.

  As shown in FIG. 6, the free bearing 95 is a known bearing in which a sphere (steel ball) 95a is rotatably mounted in a recess of a pedestal 95b, and the top of the sphere 95a makes point contact with the bottom surface of the holding frame 72. To do. In the present embodiment, four free bearings 95 are arranged at the four corners on the bottom surface of the holding frame 72 so as to support the holding frame 72 at four places, but there are three places where the holding frame 72 is supported by the free bearing 95. That is all you need.

  In this way, by supporting the holding frame 72 with respect to the base frame 71 via the free bearing 95, even if the holding frame 72 moves relative to the base frame 71, the friction load caused thereby is extremely reduced. Can be small. For this reason, lateral shift correction and inclination correction described later can be performed at high speed and with high accuracy.

  As shown in FIG. 4, a support shaft 73 is provided on the bottom surface of the holding frame 72 so as to extend downward. A lower end portion of the support shaft 73 is inserted into a width direction guide portion 71 a formed on the base frame 71. The width direction guide portion 71a is a hole formed so as to extend substantially linearly in the width direction of the recording medium P (the direction of the broken line arrow S in FIG. 5). In the present embodiment, the width direction guide portion 71a is configured by a hole portion that penetrates the upper surface portion of the base frame 71, but may be a groove portion that has a bottom portion without penetrating. In addition, a guide roller 79 is rotatably provided at the lower end portion of the support shaft 73, and the support shaft 73 is inserted into the width direction guide portion 71a via the guide roller 79.

  The support shaft 73 and the guide roller 79 are movable in the extending direction of the width direction guide portion 71a (the width direction S of the recording medium P). As the support shaft 73 moves along the width direction guide portion 71 a, the holding frame 72 can reciprocate in the width direction S of the recording medium P with respect to the base frame 71. The holding frame 72 is also configured to rotate with respect to the base frame 71 about the support shaft 73 (in the direction of the broken line arrow W in FIG. 5).

  The movable frame 81 is configured to be rotatable on the upper surface of the base frame 71 (in the direction of the broken line arrow Z in FIG. 5) around the rotation shaft 63 a of the motor 63 installed on the base frame 71. The movable frame 81 and the holding frame 72 are interlocked and connected via a connecting shaft 74. Specifically, the connecting shaft 74 is provided so as to extend downward from the holding frame 72, and a lower end portion thereof is substantially straight in a radial direction (direction of a broken line arrow R in FIG. 5) intersecting the rotation direction of the movable frame 81. It is inserted in the radial direction guide part 81a formed so that it may extend in a shape. In the present embodiment, the radial guide portion 81a is configured by a hole portion that penetrates the movable frame 81, but may be a groove portion that has a bottom portion without penetrating. Further, a guide roller 82 is rotatably provided at the lower end portion of the connecting shaft 74 in the same manner as the support shaft 73, and the connecting shaft 74 is inserted into the radial guide portion 81a via the guide roller 82. Yes.

  Since the holding frame 72 and the movable frame 81 are connected as described above, both the frames 72 and 81 are interlocked with each other. For example, in FIG. 7, when the support shaft 73 is moved in the right direction in the drawing along the width direction guide portion 71a and the holding frame 72 is moved in the same direction, the connecting shaft 74 is also moved in the right direction in the drawing. Moving. As the connecting shaft 74 moves, the movable frame 81 is interlocked so as to rotate clockwise around the rotating shaft 63a. On the other hand, as shown in FIG. 8, when the connecting shaft 74 is moved upward along the radial guide portion 81a without moving the support shaft 73, the movable frame 81 is centered on the rotating shaft 63a. While rotating clockwise in the figure, the holding frame 72 is interlocked so as to rotate clockwise around the support shaft 73 in the figure. 7 and 8, when the support shaft 73 or the connecting shaft 74 is moved in the opposite direction, the moving direction or the rotating direction of the frames 72 and 81 is opposite.

  Here, as shown in FIG. 4, the driving roller 31 b of the pinching roller 31 and the motor 61 that rotationally drives the driving roller 31 b are connected to each other via the transmission members of the gear trains 66 and 67. Therefore, when the holding frame 72 moves or rotates in the width direction as described above, the relative position between the drive roller 31b and the motor 61 changes. Therefore, in the present embodiment, the two-stage spline cup is added to the gear trains 66 and 67 so that the drive transmission from the motor 61 to the drive roller 31b can be satisfactorily performed even if the holding frame 72 moves or rotates in the width direction. It is connected via a ring 65.

  As shown in FIG. 9, the two-stage spline coupling 65 includes a first spline gear 65a, a second spline gear 65b, an intermediate spline gear 65c, a guide ring 65d, and the like. The first spline gear 65 a is an external gear, and is provided on the rotation shaft 67 a of one gear 67 of the gear trains 66 and 67. The second spline gear 65 b is an external gear and is provided on the shaft portion of the drive roller 31 b of the pinching roller 31. The intermediate spline gear 65c is an internal gear, and extends in the width direction of the recording medium P so as to mesh with the two spline gears 65a and 65b even if the holding frame 72 moves in the width direction of the recording medium P. ing. The two spline gears 65a and 65b are formed in a crown shape so as to mesh with the intermediate spline gear 65c even when the holding frame 72 rotates. The guide ring 65d is a substantially annular stopper member, and prevents the two spline gears 65a and 65b from moving relative to each other in the width direction and falling off the two-stage spline coupling 65. 65c is provided at both ends in the width direction.

  By using such a two-stage spline coupling 65, even if the holding frame 72 rotates or moves in the width direction, the driving force of the motor 61 fixed to the frames 69 to 71 of the apparatus main body is used as the clamping roller 31. Is accurately transmitted to the drive roller 31b. Thereby, the pinching roller 31 is driven to rotate favorably.

  As shown in FIG. 4, a rotary encoder 96 as a rotation detecting means for detecting the amount of rotation of the drive roller 31b is provided at the end of the drive roller 31b opposite to the side to which the rotational driving force is applied. It has been. The clamping roller 31 feeds back the detection result of the rotary encoder 96, and the rotation speed and rotation timing are controlled with high accuracy.

  Further, the holding roller 31 together with the holding frame 72 is attached to the apparatus main body (the main body frame 70, the base frame 71, and the movable frame 81) of the conveying device 30 together with the holding frame 72 based on the detection result of the CIS 36 as the lateral deviation detecting means. Based on the detection result of the first belt drive mechanism 75 that reciprocates in the width direction and the skew detection sensor 35 as the inclination detection means, the holding roller 72 and the holding roller 72 are moved in the inclination direction of the recording medium P and opposite to this. A second belt drive mechanism 76 that rotates in the direction is provided.

  As shown in FIG. 4, the first belt drive mechanism 75 includes an endless belt 77 stretched by a drive pulley 83 and a tension pulley 84 as a rotation support, and a belt 77 that rotates the drive pulley 83 to rotate. The motor 62 or the like as belt driving means for rotating the belt. The motor 62 is provided on the base frame 71, and a drive pulley 83 is attached to the upper end portion of the rotating shaft 62 a of the motor 62. On the other hand, a rotary encoder 57 as a rotation detecting means for detecting the amount of rotation of the motor 62 is attached to the opposite end (lower end) of the rotation shaft 62a of the motor 62.

  As shown in FIG. 5, the tension pulley 84 is attached to a support portion 87 provided on the base frame 71 via a tension spring 89 as an urging member. The belt 77 is held by the tension spring 89 in a state where a predetermined tension is applied.

  A support shaft 73 that is a rotation fulcrum of the holding frame 72 is integrally attached to the belt 77. Specifically, a support shaft 73 is attached to a linear portion of a belt 77 stretched between the drive pulley 83 and the tension pulley 84 via an attachment member 91.

FIG. 10A is a cross-sectional view of the attachment member 91 of the first belt drive mechanism 75 as viewed from above.
As shown in FIG. 10A, the attachment member 91 has a pair of clamping portions 91a and 91b for holding the belt 77 with the belt 77 interposed therebetween. FIG. 10B is a side view of the upper holding portion 91a in FIG. 10A, and FIG. 10C is a side view of the lower holding portion 91b in FIG.

  A plurality of fitting grooves 91c into which the convex portions 77a arranged in the circumferential direction (moving direction) of the belt 77 are fitted are formed in the upper clamping portion 91a in FIG. In the present embodiment, the fitting groove 91c is configured by a hole that penetrates the clamping portion 91a, but may be a groove having a bottom that does not penetrate. On the other hand, the lower holding portion 91b in FIG. 10A is provided with a cylindrical shaft holding portion 91e having an insertion hole 91d into which the support shaft 73 is rotatably inserted.

  The pair of sandwiching portions 91 a and 91 b are fixed to the belt 77 by being connected by a fixing tool such as a screw in a state where the belt 77 is sandwiched. Further, when the belt 77 is sandwiched between the pair of sandwiching portions 91a and 91b, the convex portion 77a of the belt 77 is fitted into the fitting groove 91c. Then, the support shaft 73 is integrally attached to the belt 77 by inserting the support shaft 73 into the insertion hole 91d of the shaft holding portion 91e.

  As shown in FIG. 10A, an encoder sensor 53 is attached to the holding portion 91a in which the fitting groove 91c is formed. The encoder sensor 53 is a transmissive photosensor or the like, and reads a predetermined pattern of an encoder scale 54 (see FIG. 5) provided on the base frame 71. These encoder sensor 53 and encoder scale 54 constitute a linear encoder as belt movement detecting means for detecting movement of the belt 77.

Next, the configuration of the second belt drive mechanism 76 will be described.
As shown in FIGS. 4 and 5, the second belt drive mechanism 76 is an endless belt stretched by a drive pulley 85 and a tension pulley 86 as a rotation support, similarly to the first belt drive mechanism 75. 78 and a motor 63 as belt driving means for rotating the driving pulley 85 to move the belt 78 around. However, unlike the belt 77 of the first belt drive mechanism 75, the belt 78 is provided on the movable frame 81 and is configured to be rotatable integrally with the movable frame 81. Here, when the movable frame 81 rotates around the rotating shaft 63a of the motor 63, the tension pulley 86 rotates around the driving pulley 85 attached to the upper end portion of the rotating shaft 63a of the motor 63 as the rotating shaft, thereby the belt 78. Rotate together.

  The tension pulley 86 is attached to a support portion 88 provided on the movable frame 81 via a tension spring 90 as an urging member. As a result, the belt 78 is held in a state where a predetermined tension is applied, like the belt 77 of the first belt drive mechanism 75. A rotary encoder 58 is attached to the lower end of the motor 63 as rotation detecting means for detecting the amount of rotation.

  A connecting shaft 74 that connects the holding frame 72 and the movable frame 81 is integrally attached to the belt 78. Specifically, the connecting shaft 74 is attached to the linear portion of the belt 78 stretched between the drive pulley 85 and the tension pulley 86 via the attachment member 92.

FIG. 11 is a cross-sectional view of the attachment member 92 of the second belt drive mechanism 76 as viewed from above.
The mounting member 92 has basically the same configuration as the mounting member 91 shown in FIG. As shown in FIG. 11, the attachment member 92 has a pair of clamping parts 92a and 92b. A plurality of fitting grooves 92c into which convex portions 78a arranged in the circumferential direction (moving direction) of the belt 78 are fitted are formed in one clamping portion 92a, and the connecting shaft 74 is rotatable in the other clamping portion 92b. A cylindrical shaft holding portion 92e in which an insertion hole 92d to be inserted is formed is provided. Here, the connecting shaft 74 is inserted through the bearing 93 into the shaft holding portion 92e. As in the case of the mounting member 91, the fitting groove 92c formed in the one sandwiching portion 92a may be a hole portion that penetrates the sandwiching portion 92a or a groove portion that has a bottom portion that does not penetrate.

  Similarly to the above, these sandwiching portions 92a and 92b also sandwich the belt 78 so that the convex portion 78a of the belt 78 fits into the fitting groove 92c, and are connected to each other by a fixing tool such as a screw. It is fixed against. Then, the connecting shaft 74 is integrally attached to the belt 78 by inserting the connecting shaft 74 into the insertion hole 92 d of the shaft holding portion 92 e through the bearing 93.

  The second belt drive mechanism 76 is also provided with a linear encoder as belt movement detection means for detecting the movement of the belt 78, as with the first belt drive mechanism 75. The linear encoder includes an encoder sensor 55 attached to the attachment member 92 and an encoder scale 56 provided on the movable frame 81. As shown in FIG. 11, here, the encoder sensor 55 is attached to the holding portion 92b provided with the shaft holding portion 92e. However, depending on the component layout, the encoder sensor 55 is attached to the holding portion 92a formed with the fitting groove 92c. May be.

Here, the operation of the holding frame 72 by the first belt driving mechanism 75 and the second belt driving mechanism 76 will be described with reference to FIGS.
First, when the holding frame 72 is moved in the width direction of the recording medium P, the belt 77 is moved around by driving the motor 62 of the first belt drive mechanism 75, and the support shaft 73 is moved to the width direction guide portion 71a. Move along. For example, in FIG. 7, when the support shaft 73 is moved in the right direction in the drawing, the holding frame 72 is also moved in the right direction in the drawing, that is, in the width direction of the recording medium P. Further, when the motor 62 is rotated in the reverse direction, the support shaft 73 moves in the left direction in the figure, and the holding frame 72 also moves in the left direction in the figure.

  Next, when rotating the holding frame 72, the belt 63 is moved around by driving the motor 63 of the second belt drive mechanism 76, and the connecting shaft 74 is moved along the radial guide portion 81a. For example, in FIG. 8, when the connecting shaft 74 is moved upward in the figure, the holding frame 72 rotates in the clockwise direction in the figure around the support shaft 73. On the other hand, when the motor 63 is rotated in the reverse direction, the connecting shaft 74 is moved downward in the figure, and the holding frame 72 is rotated counterclockwise in the figure.

Hereinafter, based on FIG.12 and FIG.13, an example of operation | movement of the conveying apparatus 30 comprised as mentioned above is demonstrated.
12 (a1) to (c1) and FIGS. 13 (a1) to (b1) are plan views showing the operation of the conveying device 30 in the order shown in FIGS. 12 (a2) to (c2). FIGS. 13 (a2) to (b2) are side views of the transfer device 30 corresponding to the operations of FIGS. 12 (a1) to (c1) and FIGS. 13 (a1) to (b1), respectively.

  First, as shown in FIGS. 12A1 and 12A2, the recording medium P fed from one of the paper feeding units is sandwiched by the third transport roller pair 44 toward the sandwiching roller 31. Be transported. The white arrow direction in the figure is the conveyance direction of the recording medium P. At this time, the nipping roller 31 has a rotation direction position at a first reference position (a normal position corresponding to the recording medium P without inclination), and a width direction position at a second reference position (a recording medium P without lateral deviation). In the normal position). In the present embodiment, the support shaft 73 serving as the rotation fulcrum of the holding frame 72 that holds the sandwiching roller 31 is disposed at a position corresponding to the width direction end portion reference position Y of the recording medium P that is conveyed without being inclined or laterally displaced. Has been.

  When the recording medium P reaches the position of the CIS 36 as the lateral deviation detecting means, the lateral deviation amount (position deviation amount in the width direction) 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 as the tilt detection means, the skew detection sensor 35 detects the tilt amount (skew amount) β of the recording medium P. Note that the lateral deviation amount directly detected by the CIS 36 is in a state where the recording medium P is tilted, and therefore, the skew detection is detected from the detection result detected by the skew detection sensor 35 and the position of the CIS 36 thereafter. Based on the distance to the position of the sensor 35 and the like, the amount of lateral deviation when there is no inclination is obtained by the calculation unit (control unit).

  Then, based on the detection results of the skew detection sensor 35 and the CIS 36, the holding frame 72 is moved and rotated in the width direction, and as shown in FIGS. 12 (b1) and 12 (b2), the sandwiching roller 31 is recorded. The medium P is rotated and moved in the width direction in accordance with the inclination and lateral deviation of the medium P. That is, the sandwiching roller 31 is rotated from the first reference position by the angle β around the support shaft 73 in the same inclination direction according to the detected inclination amount β, and the same width according to the detected positional deviation amount α. It is moved in the width direction from the second reference position by a distance α in the direction. Further, the pinching roller 31 starts to be rotated immediately before the leading end of the recording medium P reaches the pinching roller 31.

  Then, as shown in FIGS. 12C1 and 12C2, when the leading end portion of the recording medium P reaches the sandwiching roller 31, and the recording medium P is sandwiched and transported by the sandwiching roller 31, the third transport roller pair 44. Moves apart in a direction that opens the transport path and does not pinch the recording medium P. Note that the timing at which the leading end of the recording medium P reaches the clamping 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 a calculation unit (control unit) based on the distance from the position of the CIS 36 to the position of the clamping roller 31.

  13 (a1) and 13 (a2), the sandwiching roller 31 supports the shaft so as to cancel the tilt amount β detected by the skew detection sensor 35 while sandwiching / conveying the recording medium P. Rotate around the center 73 to return to the first reference position, and move in the width direction so as to return to the second reference position so as to cancel out the lateral shift amount α detected by the CIS 36. In this way, the recording medium P is conveyed toward the transfer unit 7 (image forming unit) while performing tilt correction and lateral shift correction. At this time, the number of rotations of the nipping roller 31 (the conveyance speed of the recording medium P until reaching the transfer unit 7) is adjusted by adjusting the driving of the motor 61 so that the timing is synchronized with the image on the photosensitive drum 5. Is done.

  Then, as shown in FIGS. 13B1 and 13B2, the recording medium P is conveyed toward the transfer unit 7 (image transfer unit), and the image is transferred to a desired position on the recording medium P. become. At this time, the nipping roller 31 is positioned at the first reference position and the second reference position in preparation for the inclination correction and the lateral deviation correction of the recording medium P to be conveyed next. Then, the third conveying roller pair 44 in the separated state is returned to the contact state to assist the conveyance of the recording medium P by the nipping roller 31 and to prepare for the conveyance operation of the recording medium P to be conveyed next. become.

  As described above, in the present embodiment, the clamping roller 31 rotates in the tilt direction based on the detection result of the skew detection sensor 35 while holding the recording medium P without stopping the conveyance of the recording medium P. Thus, the positional deviation amount in the tilt direction of the recording medium P is corrected, and the positional deviation amount in the width direction of the recording medium P is corrected by moving in the width direction based on the detection result of the CIS 36. 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 inclination correction or the lateral deviation correction is performed separately.

  In addition, in the configuration of the present embodiment, the first belt driving mechanism 75 and the second belt driving mechanism 76 having the heavy motors 62, 63 and the like, and the motor 61 for driving the clamping roller 31 are provided on the apparatus main body side. Since these are not provided on the holding frame 72, the structure installed on the holding frame 72 can be reduced in weight. As a result, it is easy to move the holding frame 72 at high speed and with high accuracy, and it is possible to correct the tilt and lateral deviation of the recording medium P at high speed and with high accuracy. In addition, a relatively small output motor (drive source) can be used to drive the holding frame 72, and the apparatus can be reduced in size and weight.

  In the present embodiment, the support shaft 73 or the connecting shaft 74 is attached to the belts 77 and 78 of the first belt drive mechanism 75 and the second belt drive mechanism 76 so that they are moved. There are few gaps between the components constituting the drive mechanism, and the motor drive response is excellent.

  Further, in the present embodiment, the motors 62 and 63 are affected by the effects of a gap between components, tension fluctuation and expansion / contraction of the belts 77 and 78, frictional resistance between the recording medium P and the conveyance guide, or driving frictional resistance of the holding frame 72. The rotary encoders 57 and 58 that detect the rotation amount of the motors 62 and 63 and the linear encoder that detects the movement amount of the belts 77 and 78 even if an error occurs between the rotation amount of the belts 77 and 78. The error can be grasped based on the detection results of the encoder sensors 53 and 55 and the encoder scales 54 and 56). Then, by adjusting the rotation amounts of the motors 62 and 63 based on the grasped error, it is possible to perform more accurate inclination correction and lateral deviation correction.

  In the present embodiment, the clamping roller 31 and the motor 61 are connected using the two-stage spline coupling 65, so that the clamping roller 31 rotates or slides together with the holding frame 72. In addition, the connection state between the two can be maintained satisfactorily, and the drive can be reliably transmitted to the pinching roller 31.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, Of course, a various change can be added in the range which does not deviate from the summary of this invention.

  For example, as shown in FIG. 14, the support shaft 73 of the holding frame 72 may be arranged in parallel to the two-stage spline coupling 65 in a direction substantially orthogonal to the rotation axis direction of the sandwiching roller 31. In the example shown in FIG. 14, the support shaft 73 is disposed at a position directly below the two-stage spline coupling 65. In such a configuration, since the deflection angle generated in the two-stage spline coupling 65 can be reduced when the clamping roller 31 (holding frame 72) is rotated in accordance with the inclination correction, the two-stage spline cup is reduced. The rotational driving force transmitted from the motor 61 to the pinching roller 31 via the ring 65 can be transmitted with higher accuracy.

  In the above-described embodiment (see FIG. 4), as the sandwiching roller 31, a roller portion is used that is not divided in the axial direction but continuously extends in the axial direction. You may use the roller pair which has the roller part divided into multiple in the axial direction like a form. In the above-described embodiment, the CIS 36 is arranged only on one end side in the width direction so as to detect the position of the side end Pa on the one end side in the width direction of the recording medium P. It is also possible to detect the positions of the side edge portions at both ends in the width direction of the recording medium P.

  Further, the above-described embodiment is an example in which the configuration of the present invention is applied to a conveyance device that performs inclination correction and lateral deviation correction of a transfer sheet serving as a recording medium P. The present invention can also be applied to a conveyance device (document conveyance device) that performs document inclination correction and lateral deviation correction. Further, the conveying device according to the present invention is not limited to that mounted on a monochrome image forming apparatus as shown in FIG. 1, but is mounted on a color image forming apparatus or an image forming apparatus other than an electrophotographic system. (For example, an inkjet image forming apparatus, an offset printing machine, or the like) may be mounted.

1 Copying machine (image forming device)
30 Conveying device 31 Nipping roller 35 Skew detection sensor (tilt detection means)
36 CIS (lateral deviation detection means)
61 Motor (Nipping roller driving means)
65 Two-stage spline coupling 70 Body frame 71 Base frame (fixed support)
71a Width direction guide part 72 Holding frame (holding member)
73 Support shaft 74 Connection shaft 75 First belt drive mechanism 76 Second belt drive mechanism 77 Belt 78 Belt 81 Movable frame (movable support)
81a Radial guide 95 Free bearing

Japanese Patent Laid-Open No. 10-67448

Claims (10)

A transport device for transporting a recording medium,
An inclination detecting means for detecting an inclination amount with respect to the conveyance direction of the recording medium;
A lateral deviation detecting means for detecting a positional deviation amount in the width direction orthogonal to the conveyance direction of the recording medium;
A sandwiching roller that transports the recording medium in a sandwiched state;
A holding member configured to rotatably hold the sandwiching roller, to reciprocate in the width direction of the recording medium with respect to the apparatus main body, and to be rotatable in the tilt direction of the recording medium and in the opposite direction;
A first belt drive mechanism for reciprocating the clamping roller in the width direction of the recording medium together with the holding member based on a detection result of the lateral deviation detection means;
A second belt drive mechanism for rotating the clamping roller together with the holding member in the tilt direction of the recording medium and in the opposite direction based on the detection result of the tilt detection means;
A conveying apparatus, wherein the first belt driving mechanism and the second belt driving mechanism are provided on the apparatus main body side. The apparatus main body includes a fixed support and a movable support provided to be rotatable with respect to the fixed support.
The holding member is reciprocally movable in the width direction of the recording medium with respect to the fixed support, and is provided so as to be rotatable in the tilt direction of the recording medium and in the opposite direction, and with respect to the movable support. The transport device according to claim 1, wherein the transport device is connected so as to be capable of reciprocating in a radial direction intersecting a rotation direction of the movable support. A width direction guide portion extending in the width direction of the recording medium is provided on the fixed support,
The transport apparatus according to claim 2, wherein a support shaft serving as a center when the holding member rotates with respect to the fixed support is inserted so as to be movable in the extending direction with respect to the width direction guide portion. The movable support body is provided with a radial guide portion extending in a radial direction intersecting the rotation direction,
The conveying apparatus of Claim 2 or 3 which inserted the connection shaft used as the part with which the said holding member is connected with respect to the said movable support body so that the movement to the extension direction is possible with respect to the said radial direction guide part.   4. The transport device according to claim 3, wherein the first belt driving mechanism includes a belt to which the support shaft is integrally attached and reciprocates the support shaft along the width direction guide portion.   5. The transport device according to claim 4, wherein the second belt driving mechanism includes a belt to which the connecting shaft is integrally attached and reciprocates the connecting shaft along the radial guide portion.   The conveying apparatus according to any one of claims 1 to 6, wherein the holding member is supported via free bearings arranged at three or more locations with respect to the apparatus main body. Provided on the apparatus main body side is a sandwiching roller driving means for rotationally driving the sandwiching roller,
The conveying apparatus according to any one of claims 1 to 7, wherein the sandwiching roller driving unit and the sandwiching roller are coupled to each other via a two-stage spline coupling so as to be able to transmit a driving force.   The transport apparatus according to claim 8, wherein a center when the holding member rotates with respect to the apparatus main body is arranged in a direction substantially perpendicular to a rotation axis direction of the clamping roller with respect to the two-stage spline coupling.   An image forming apparatus comprising the transport device according to claim 1.

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