JP6885064B2 - Conveyor device and image forming device - Google Patents

Description

The present invention relates to a transport device for transporting sheets, and an image forming device such as a copying machine, a printer, a facsimile, or a composite machine thereof or an offset printing machine provided with the transport device.

Conventionally, in image forming devices such as copiers and printers, a plurality of CIS (contact image sensors) are installed at intervals in the transport direction in the transport path, and based on the detection results, the sheet is slanted. Corrects the misalignment (oblique) in the direction, and corrects the misalignment in the width direction of the sheet (the direction orthogonal to the transport direction) (hereinafter, appropriately referred to as "horizontal resist") to the normal position. A technique for correcting is known (see, for example, Patent Document 1).

Specifically, the image forming apparatus in Patent Document 1 is provided with a holding roller configured to be able to rotate in an oblique direction or move in a width direction while holding and transporting a sheet. Further, two CIS are arranged side by side along the transport path on the upstream side of the holding roller, and one CIS is installed on the downstream side of the holding roller. Each of these CISs detects a side edge of the sheet passing through that position.
Then, the sandwiching roller rotates in the oblique direction to perform skew correction (skew correction) based on the detection results detected by the two CIS on the upstream side while sandwiching and conveying the sheet, and also performs skew correction in the width direction. The horizontal resist is corrected by moving to. After that, the sandwiching roller rotates and further tilts in an oblique direction based on the detection results detected by the two CIS on the downstream side while sandwiching and transporting the sheet that has been subjected to the skew correction and the lateral resist correction. In addition to performing line correction, it moves in the width direction to further perform horizontal resist correction.

In the above-mentioned conventional technique, shading correction and zero point alignment of a plurality of CIS arranged side by side in the transport path cannot be performed efficiently and with high accuracy.
In particular, even if shading correction and zero point alignment of multiple CIS are performed with high accuracy during manufacturing, when the sensitivity of multiple CIS changes due to repeated use of the device by the user in the market. When CIS replacement maintenance is performed by a service person in the market, it is necessary to efficiently and highly accurately perform shading correction and zero point alignment of a plurality of CIS.
If the accuracy of shading correction and zero point alignment of a plurality of CIS is lowered, the accuracy of skew correction and lateral resist correction based on the detection results of the plurality of CIS is also lowered.

The present invention has been made to solve the above-mentioned problems, and can efficiently and highly accurately perform shading correction and zero point alignment of a plurality of CIS arranged side by side in a transport path. It is an object of the present invention to provide an apparatus and an image forming apparatus.

The transport device in the present invention is a transport device that transports sheets in a transport path, has a plurality of photosensors arranged side by side in the width direction, and detects sheets transported in a predetermined transport direction in the transport path. A plurality of CISs are installed in the transport direction, and the plurality of CISs perform shading correction for correcting the output voltage by detecting an adjustment reference plate arranged so as to face all of the plurality of CISs. and zero point alignment defining a photosensor as a reference among the plurality of photo sensors, cracks Gaokona, the adjustment reference plate is provided with an edge portion extending linearly parallel to the conveying direction, said plurality The shading correction is performed by reading the output voltage in a state where the facing surfaces facing the CIS are facing each other and the facing surfaces of the adjustment reference plate are opposed to the plurality of CIS, and the plurality of CIS are subjected to the shading correction. The zero point alignment is performed by detecting the edge portion in a state where the edge portions of the adjustment reference plate are opposed to each other.

According to the present invention, it is possible to provide a transport device and an image forming device capable of efficiently and highly accurately performing shading correction and zero point alignment of a plurality of CIS arranged side by side in a transport path. ..

It is an overall block diagram which shows the image forming apparatus in Embodiment 1 of this invention. It is the schematic which shows the transport device. It is a top view which shows a part of the transport device. It is a perspective view which shows the main part of the transport device. It is the schematic which shows the operation of a transport device. It is the schematic which shows the operation of the transport device following FIG. (A) A schematic top view showing a state in which the facing surfaces of the adjustment reference plates are installed so as to face a plurality of CIS, and (B) an edge portion of the adjustment reference plate is installed so as to face a plurality of CIS. It is a schematic top view showing a state. It is a schematic side view which looked at the state which the adjustment reference plate was installed in the transport device in the transport direction. (A) A schematic side view showing a state in which the facing surfaces of the adjustment reference plate are set to face the plurality of CIS, and (B) the edge portion of the adjustment reference plate is set to face the plurality of CIS. It is a schematic side view showing a state. It is a graph which shows the output voltage of the whole of CIS. As a modification 1, (A) a schematic side view showing a state in which the facing surfaces of the adjustment reference plates are set to face a plurality of CIS, and (B) an edge portion of the adjustment reference plate facing a plurality of CIS. It is a schematic side view which shows the state which is set to do so. In the transport device according to the second embodiment of the present invention, (A) a schematic top view showing a state in which the adjustment reference plate has been moved to the first position, and (B) a schematic view showing a state in which the adjustment reference plate has been moved to the second position. It is a top view and (C) a schematic top view showing a state in which the adjustment reference plate is moved to the third position. (A) A schematic side view showing a state in which the adjustment reference plate is moved to the third position, and (B) a schematic side view showing a state in which the adjustment reference plate is moved from the third position to the center side in the width direction. It is a schematic top view which shows the state which the adjustment reference plate moved to the 3rd position in the transport device in the modification 2. (A) A schematic side view showing a state in which the adjustment reference plate has been moved to the third position, and (B) a schematic side view showing a state in which the adjustment reference plate has been rotated from the third position.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are designated by the same reference numerals, and the duplicated description thereof will be appropriately simplified or omitted.

<Embodiment 1>
The first embodiment of the present invention will be described in detail with reference to FIGS. 1 to 10.
First, FIG. 1 describes the overall configuration and operation of the image forming apparatus.
In FIG. 1, 1 is a copying machine as an image forming apparatus, 2 is a document reading unit that optically reads image information of a document D, and 3 is a photoconductor that emits exposure light L based on the image information read by the document reading unit 2. The exposure unit 4 that irradiates the surface of the drum 5 is an image forming unit that forms a toner image (image) on the surface of the photoconductor drum 5 as an image carrier, and 7 is a toner image formed on the surface of the photoconductor drum 5. A transfer roller as a transfer unit for transferring the image to the sheet P, 10 is a document transfer unit for transporting the set document D to the document reading unit 2, and 12 to 14 are supplies in which the sheet P (recording medium) such as paper is stored. The paper unit (paper feed cassette), 20 is a fixing device for fixing the unfixed image on the sheet P, 21 is a fixing roller installed in the fixing device 20, 22 is a pressurizing roller installed in the fixing device 20, and 30 is. A transport device that transports the sheet P along the transport path, 31 is a holding roller (horizontal resist / skew correction roller) that functions as a resist roller (timing roller) that transports the sheet P toward the transfer roller 7 (image forming unit). ), Indicates.

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 transfer roller of the document transfer 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). Then, the exposure light L (laser beam) based on the image information of the electric signal is emitted from the exposure unit 3 toward the surface of the photoconductor drum 5 of the image forming unit 4.

On the other hand, in the image forming unit 4, the photoconductor drum 5 is rotated in the clockwise direction of FIG. 1, and undergoes a predetermined image forming process (charging step, exposure step, developing step), and image information is displayed on the photoconductor drum 5. An image (toner image) corresponding to is formed.
After that, the image formed on the surface of the photoconductor drum 5 is an image forming portion (transfer nip) in which the transfer roller 7 and the photoconductor drum 5 come into contact with each other, and the sheet P conveyed by the holding roller 31 functioning as a resist roller. Transferred on.

On the other hand, referring to FIGS. 1 and 2, the sheet P conveyed to the position (image forming portion) of the transfer roller 7 operates as follows.
First, one of the plurality of paper feed units 12 to 14 of the image forming apparatus main body 1 is automatically or manually selected (for example, the paper feed unit 12 built in the device main body 1 is selected. It shall be.).
Then, the uppermost sheet of the sheet P housed in the paper feed unit 12 is supplied by the paper feed roller 41 toward the curved transport path in which the first transport roller pair 42 and the second transport roller pair 43 are installed. Will be sent.

After that, the sheet P passes through the position of the merging portion X (the portion where the transport paths from the two paper feeding units 13 and 14 installed outside the apparatus main body 1 merge) from the curved transport path, and then passes through the position. The third transport roller pair 44 and the matching portion 51 pass through the straight transport path in which the matching portion 51 is installed, and reach the position of the holding roller 31 constituting the matching portion 51. Then, skew correction and lateral resist correction are performed by the sandwiching roller 31 constituting the matching portion 51, and the transfer roller is timed to align with the image formed on the photoconductor drum 5. It is conveyed toward the position 7 (image forming portion).

Then, the sheet P after the transfer step reaches the fixing device 20 via the transfer path after passing through the position of the transfer roller 7 (transfer portion). The sheet 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 sheet P on which the image is fixed is sent out from between the fixing roller 21 and the pressure roller 22 (which is the nip portion), and then discharged from the image forming apparatus main body 1.
In this way, a series of image forming processes is completed.

Here, referring to FIG. 2, the image forming apparatus 1 in the first embodiment can feed the sheet P from the three paper feeding units 12 to 14 toward the position of the transfer roller 7 (image forming unit). It is configured as follows.
Further, the transport roller pairs 42 to 44 (including unmarked transport roller pairs) installed in the transport device 30 are all a drive roller (a roller that is rotationally driven by a drive mechanism). It is a roller pair composed of a driven roller (a roller that rotates driven by frictional resistance with a driving roller), and is configured so that the seat P can be conveyed while being sandwiched between the two rollers. Further, the transfer roller 7 abuts on the photoconductor drum 5 at the image forming portion (transfer nip) in a state where a predetermined transfer bias is applied, and rotates counterclockwise with the photoconductor drum 5 in the drawing. The image carried on the photoconductor drum 5 is transferred to the sheet P while carrying the sheet P sandwiched between the two.

Here, the position of the transfer roller 7 (image formation) from the confluence X where the transfer path from the first paper feed section 12 and the transfer path from the second and third paper feed sections 13 and 14 merge. As a transport path to the section), a linear transport path formed substantially linearly along the transport direction of the sheet P is provided. This linear transport path is formed by linear transport guide plates 65 and 66 (guide plates installed so as to sandwich the front and back surfaces of the sheet P to be transported, and FIG. 8 can be referred to), and the linear transport path is formed by a transport direction. A third transport roller pair 44, a first CIS35, a second CIS36, a holding roller 31 (matching portion 51), and a third CIS37 are installed along the above. The third transfer roller pair 44 and the holding roller 31 are both a roller pair consisting of a driving roller and a driven roller, and the seat P is conveyed while being sandwiched between the two rollers. Then, the sandwiching roller 31 performs a matching operation of skew correction (correction for position deviation in the oblique direction with respect to the transport direction) and lateral resist correction (correction for position deviation in the width direction). It will also function as the matching unit 51 of the above, which will be described in detail later.

Next, with reference to FIGS. 2 to 10, the transport device 30 characteristic of the first embodiment will be described in detail.
Hereinafter, the configuration in the transport path from the confluence portion X to the transfer roller 7 (image forming portion) and the operation performed therethrough will be mainly described.
With reference to FIGS. 2 and 3, the transfer device 30 is provided with the third transfer roller pair 44, the third transfer roller pair 44, along the linear transfer path of the sheet P (the transfer path from the merging portion X to the transfer roller 7). The first CIS35, the second CIS36, the sandwiching roller 31 (horizontal resist / skew correction roller) that functions as a matching portion 51 and also as a resist roller, and the third CIS37 are installed.
Each of the three CIS 35 to 37 is a contact image sensor composed of a plurality of photosensors arranged side by side in the width direction (matching in the vertical direction of the paper surface in FIG. 2 and in the vertical direction in FIG. 3). Therefore, the side end portion (edge portion) of the sheet P passing through the position is optically detected.
As described above, in the transport device 30 according to the first embodiment, a plurality of CIS for detecting the side end portions of the sheets P transported in the predetermined transport direction in the transport path are installed at intervals in the transport direction. There is.

Here, the sandwiching roller 31 is a roller pair having a plurality of roller portions divided in the width direction, and is rotated by a first drive motor 59 (see FIG. 4) as a drive means (first drive means). It is composed of a driven roller 31a to be driven and a driven roller 31b that rotates in accordance with the rotation of the driving roller 31a. The sandwiching roller 31 is formed so that the sheet P can be conveyed by rotating while sandwiching the sheet P.
In the first embodiment, as the sandwiching roller 31, a roller pair having a plurality of roller portions divided in the width direction is used, but a roller having a roller portion extending in the width direction without being divided in the width direction is used. Pairs can also be used.

Further, the holding roller 31 is formed so as to be able to rotate in an oblique direction (rotation in the double-headed arrow W direction in FIG. 3) and in the width direction (in the direction of the dashed double-headed arrow S in FIG. 3). It is formed so that it can be moved to.

Specifically, referring to FIG. 4, the sandwiching roller 31 (driving roller 31a and driven roller 31b) is rotationally driven by a first driving motor 59 as a driving means (first driving means) to sandwich the seat P. Transport in the state.
Specifically, the first drive motor 59 (first drive means) is fixedly installed on the frame of the transfer device 30 (image forming device 1). The first drive motor 59 has a gear portion 76a (sufficient in the width direction) of the frame-side rotating shaft 76 in which the drive gear 59a installed on the motor shaft is rotatably held by the standing portion 71b of the base portion 71 (frame). The frame-side rotation shaft 76 is rotationally driven in the direction of the arrow W in FIG. Then, when the frame-side rotating shaft 76 is rotationally driven, the rotational driving force is transmitted to the rotating shaft of the driving roller 31a via the coupling 75, the driving roller 31a rotates, and the driven roller 31a is driven accordingly. 31b will also rotate.
Here, the coupling 75 interposed between the rotating shaft of the drive 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. The holding roller 31 rotates together with the holding member 72 by the drive of the second drive motor 62, which will be described later, and the rotation speed changes even if the axis angle between the rotation shaft of the drive roller 31a and the frame side rotation shaft 76 changes. The rotational driving force is transmitted without the occurrence of.

Further, the holding 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, the drive roller 31a and the driven roller 31b are rotatably held by the holding member 72 at both ends in the width direction of the rotating shaft via bearings (fixed to the holding member 72), respectively. ing. Further, the drive roller 31a and the driven roller 31b are respectively held by the holding member 72 so as to be movable in the width direction (rotational axis direction). In particular, a sufficient gap is provided between the support column portion 72b on one end side of the holding member 72 and the gear portion 72a, and even if the drive roller 31a and the driven roller 31b slide to one end side in the width direction, The rotating shafts are configured so as not to interfere with the gear portion 72a.
Further, the holding member 72 is rotatably supported around the shaft portion 71a with respect to the base portion 71 that functions as a part of the frame of the transport device 30 (image forming device 1). Further, a second drive motor 62 (rotary motor) as a second drive means is fixedly installed on one end side in the width direction of the base portion 71, and is formed on the motor shaft 62a of the second drive motor 62. The gear is formed so as to mesh with the gear portion 72a formed on one end side in the width direction of the holding member 72. As a result, the holding roller 31 rotates about the shaft portion 71a together with the holding member 72 by rotationally driving the second drive motor 62 in the forward and reverse directions (rotation in the double-headed arrow W direction of FIGS. 3 and 4). .) Will be. The second drive motor 62 (second drive means) is configured to be able to rotate the holding member 72 in an oblique direction together with the holding roller 31 based on the detection results of CIS 35 to 37 described later. A known encoder is installed on the motor shaft of the second drive motor 62 (rotating motor), and the amount of rotation and the direction of rotation in the diagonal direction with respect to the reference position of the holding roller 31 are indirectly detected. It is configured as follows. As a result, skew correction by the holding roller 31 based on the detection result of CIS 35 to 37 becomes possible.
In the first embodiment, the holding roller 31 (holding member 72) is configured to rotate about the central position in the width direction, but the holding roller 31 (holding member 72) is at the end in the width direction. It can also be configured to rotate around a side position.

Further, on the other end side in the width direction of the frame-side rotating shaft 76 rotatably held by the base portion 71 (frame), the motor shaft 63a of the third drive motor 63 (shift motor) as the third drive means is formed. A rack gear portion 78 that meshes with the pinion gear is installed so as to be rotatable relative to the frame-side rotating shaft 76. The rack gear portion 78 is held by the frame so that it can slide along the guide rail formed on the frame together with the frame-side rotating shaft 76 in the width direction (the S direction of the double-headed arrow in FIG. 4) in a non-rotating manner. ing. Here, the third drive motor 63 (third drive means) is fixedly installed on the frame of the transfer device 30 (image forming device 1) in the same manner as the first and second drive motors 59 and 62.
On the other hand, between the coupling 75 and the support column on the other end side of the holding member 72, both rollers 31a and 31b are moved so that the drive roller 31a and the driven roller 31b move in the width direction in conjunction with each other. A connecting member 73 is provided which is rotatably connected to each other. Specifically, the connecting member 73 is sandwiched by retaining rings 81 installed in the grooves formed in the rotating shaft of the driving roller 31a and the rotating shaft of the driven roller 31b, respectively, and the driving 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, the holding roller 31 is driven in the forward and reverse directions of the third drive motor 63 in the width direction (the S direction of the double-headed arrow in FIG. 4, the vertical direction on the paper surface in FIG. 2, and the vertical direction in FIG. It will move to.). As will be described later, the third drive motor 63 (third drive means) is configured so that the holding roller 31 can be moved in the width direction together with the frame side rotating shaft 76 based on the detection results of CIS 33 to 37. is there.
A known encoder is installed on the motor shaft of the third drive motor 63 (shift motor) so that the movement amount and movement direction in the width direction with respect to the reference position of the holding roller 31 are indirectly detected. It is configured. As a result, the lateral resist correction by the holding roller 31 based on the detection result of CIS 35 to 37 becomes possible.

Then, the sandwiching roller 31 rotates diagonally together with the holding member 72 based on the detection result of two CIS out of the three CIS35 to 37 while conveying the sheet P while sandwiching the sheet P. The amount of misalignment will be corrected twice. That is, the sandwiching roller 31 functions as a means for diagonally displacing the sheet P transported in the transport path to perform skew correction (skew correction) of the sheet P.
Further, the holding roller 31 moves in the width direction based on the detection result of two CIS out of the three CIS 35 to 37 while carrying the seat P while holding the seat P, so that the position of the seat P is displaced in the width direction. The amount will be corrected twice. That is, the sandwiching roller 31 also functions as a means for correcting the lateral resist of the sheet P by displacing the sheet P transported in the transport path in the width direction.

Here, the third transport roller pair 44 is installed at a position on the upstream side (upstream side in the transport direction) with respect to the sandwiching roller 31. The third transfer roller pair 44 is formed so that the sheet P can be conveyed by rotating while sandwiching the sheet P, and can be separated so that the state in which the sheet P is sandwiched and the state in which the sheet P is not sandwiched can be switched. It is a pair of transport rollers. Then, when the seat P reaches the position of the sandwiching roller 31 and is sandwiched and conveyed by the sandwiching roller 31, the third transport roller pair 44 is switched from the state in which the sheet P is sandwiched to the state in which the sheet P is not sandwiched. ..

Further, in the first embodiment, the sandwiching roller 31 is a transfer roller pair that is arranged at a position on the upstream side of the transfer path with respect to the transfer roller 7 as the downstream transfer roller and also functions as a resist roller. Then, by rotating the sheet P in a sandwiched state, the sheet P (the sheet P after the skew correction and the lateral resist correction are performed by the sandwiching roller 31 itself) is conveyed toward the image forming portion.
Here, the first drive motor 59 that rotationally drives the holding roller 31 (drive roller 31a) is a rotation speed variable drive motor, and is formed so that the transport speed of the seat P can be changed. Then, when the timing at which the sheet P is conveyed to the position of the sandwiching roller 31 is detected by the paper detection sensor (photo sensor) (the sheet P is conveyed to the position of the sandwiching roller 31, the sheet P is sandwiched by the sandwiching roller 31. (When the state is detected), the sandwiching roller 31 performs the desired lateral resist correction and skew correction, and the transport speed by the sandwiching roller 31 is variable based on the detection result (detection timing) of the paper detection sensor. Will be done. That is, the transfer speed of the sandwiching roller 31 is adjusted so that the timing at which the sheet P is conveyed to the transfer roller 7 by the sandwiching roller 31 and the timing at which the image formed on the photoconductor drum 5 reaches the transfer roller 7 are matched. It is variable (the transfer timing of the sheet P transferred toward the image forming unit is adjusted). As a result, the image can be transferred to a desired position on the sheet P while performing lateral resist correction and skew correction on the sheet P without stopping the transfer of the sheet P by the sandwiching roller 31.
It should be noted that the sandwiching roller 31 does not distort the image transferred onto the sheet P due to a linear velocity difference with the photoconductor drum 5 immediately after the tip of the sheet P reaches the image forming portion. The transport speed will be variable (the transport speed will be variable so that the linear velocity ratio with the photoconductor drum 5 is 1).

With reference to FIG. 3, the first CIS 35 is arranged on the upstream side of the transport path with respect to the sandwiching roller 31. The second CIS 36 is arranged on the upstream side of the transport path with respect to the sandwiching roller 31, and is arranged on the downstream side of the transport path with respect to the first CIS 35. The third CIS 37 is arranged on the downstream side of the transport path with respect to the sandwiching roller 31, and on the upstream side of the transport path with respect to the transfer roller 7. Each of the three CIS 35 to 37 is composed of a plurality of photosensors (consisting of a light emitting element such as an LED and a light receiving element such as a photodiode) arranged side by side in the width direction, and is on one end side in the width direction of the sheet P. Detects the position of the side end Pa (edge).

Then, in the first embodiment, the amount of positional deviation (horizontal) in the width direction of the sheet P transported in the transport path of the transport device 30 by the first and second CIS 35, 36 (or the second and third CIS 36, 37). The amount of resist) is detected. Then, based on the detection result, the lateral resist correction is performed while sandwiching and transporting the sheet P by the sandwiching roller 31.
As a specific example, with reference to FIG. 3, the sheet P is on one end side in the width direction (lower side of FIG. 3) with respect to the normal position indicated by the alternate long and short dash line (the normal position with no positional deviation in the width direction). When the first and second CIS35, 36 (or the second and third CIS36, 37) detect a state in which the position is displaced by the distance α, the control unit uses the position deviation amount α as the correction amount. In the state where the sheet P is sandwiched and conveyed by the sandwiching roller 31, the sandwiching roller 31 (holding member 72) is moved to the other end side in the width direction (upper part of FIG. 3) by a distance α (shift control is performed). It is carried out).

More specifically, the position deviation amount M1 in the width direction of the sheet P detected by the first CIS35 (or the second CIS36) and the position deviation amount M2 in the width direction of the sheet P detected by the second CIS36 (or the third CIS37). Based on the average value of ((M1 + M2) / 2), the amount of positional deviation of the sheet P in the width direction is detected. Then, the above-mentioned average value ((M1 + M2) / 2) is set as the correction amount α to be corrected, and the sandwiching roller 31 (holding member) is sandwiched and conveyed by the sandwiching roller 31 so as to cancel the value α. 72) will be shifted (shift control will be performed).

More specifically, in the calculation unit (control unit), the position deviation amount α in the width direction is calculated based on the detection results of the first and second CIS35 and 36 (or the second and third CIS36 and 37). The count number p2 (shift motor encoder count number) in the encoder (shift motor encoder) of the third drive motor 63 is calculated based on the position shift amount α. Then, the count number p2 is stored as the "target transfer encoder count number p2" of the third drive motor 63 (shift motor). Then, based on the above-mentioned "target transfer encoder count number p2", the motor driver is controlled by the controller (shift controller) while detecting the shift position by the shift motor encoder (while performing feedback control), and the third drive is performed. The motor 63 (shift motor) will be driven.
For the calculation of the "target transfer encoder counter number", the correction amount (transport amount) per count (1 pulse) is checked in advance by calculation from the design value, and the correction amount (convey amount) is stored in the calculation unit. deep.

Further, in the first embodiment, the amount of oblique positional deviation (oblique) of the sheet P conveyed in the transfer path of the transfer device 30 by the first and second CIS 35, 36 (or the second and third CIS 36, 37). Line volume) is detected. Then, based on the detection result, skew correction is performed while sandwiching and transporting the sheet P by the sandwiching roller 31.
As a specific example, with reference to FIG. 3, the sheet P is inclined by an angle β in the positive direction (positive direction in the rotation direction) with respect to the normal position indicated by the alternate long and short dash line (the normal position without skewing). When the running state is detected by the first and second CIS35, 36 (or the second and third CIS36, 37), the control unit uses the position deviation amount β as the correction amount, and the sandwiching roller 31 sets the sheet P. The sandwiching roller 31 (holding member 72) is rotated in the opposite direction (the direction opposite to the rotation direction, which is the clockwise direction in FIG. 3) by the angle β (rotation control). It is carried out).

More specifically, the position deviation amount M1 in the width direction of the sheet P detected by the first CIS35 (or the second CIS36) and the position deviation amount M2 in the width direction of the sheet P detected by the second CIS36 (or the third CIS37). And the difference (M2-M1) divided by the separation distance H between the first CIS35 (or the second CIS36) and the second CIS36 (or the third CIS37) in the transport direction ((M2-M1) / H). Based on this, the amount of oblique positional deviation of the sheet P is detected. Then, the correction angle β to be corrected is obtained by using the above-mentioned value ((M2-M1) / H) as tan β, and the sheet P is sandwiched and conveyed by the sandwiching roller 31 so as to cancel the angle β. The roller 31 (holding member 72) is rotated to the opposite side (rotation control is performed).
The above-mentioned positional deviation amounts M1 and M2 in the width direction are all deviation amounts from the normal position (the regular position without the positional deviation in the width direction).

More specifically, in the calculation unit (control unit), the diagonal position deviation amount β is calculated based on the detection results of the first and second CIS35 and 36 (or the second and third CIS36 and 37). The count number p1 (rotation motor encoder count number) in the encoder (rotation motor encoder) of the second drive motor 62 is calculated based on the position deviation amount β. Then, the count number p1 is stored as the "target transfer encoder count number p1" of the second drive motor 62 (rotary motor). Then, based on the above-mentioned "target transfer encoder count number p1", the motor driver is controlled by the controller (rotation controller) while detecting the rotation position by the rotation motor encoder (while performing feedback control). The second drive motor 62 (rotary motor) will be driven.

As described above, in the first embodiment, the sandwiching roller 31 rotates in the oblique direction based on the detection results of the plurality of CIS 35 to 37 in the state of sandwiching the sheet P without stopping the transport of the sheet P. By doing so, the amount of the position deviation of the sheet P in the diagonal direction is corrected, and by moving in the width direction, the amount of the position deviation of the sheet P in the width direction is corrected.
As a result, the productivity of the apparatus can be remarkably improved as compared with the case where the transport of the sheet P is stopped and the skew correction and the lateral resist correction are performed separately. Further, when performing skew correction and lateral resist correction, there is no difference in linear velocity between the roller portions installed in the width direction in the sandwiching roller 31, so that the thin paper or the sheet P having a low surface friction coefficient is used. Even when the paper is passed, the sheet P does not bend or slip.

Further, in the first embodiment, the skewing correction and the lateral resist correction of the sheet P are performed twice by the sandwiching roller 31 by using the three CIS 35 to 37 arranged along the transport path.
Specifically, while the sandwiching roller 31 is sandwiching and conveying the sheet P, the skew amount and the lateral resist amount of the sheet P are detected by the first and second CIS 35 and 36, and the sheet P is based on the detection result. The skew correction is performed, and the lateral resist correction of the sheet P is performed at substantially the same timing (these corrections are appropriately referred to as "first corrections"). Further, after the "first correction" is performed, the skew amount and the lateral resist amount of the sheet P are detected by the second and third CIS 36 and 37 in a state where the sandwiching roller 31 is sandwiching and conveying the sheet P. Then, based on the detection result, the skew correction of the sheet P is performed, and the lateral resist correction of the sheet P is performed at almost the same timing (these corrections are appropriately "second correction (re-correction)". Called.).

Here, in the first embodiment, the sandwiching roller 31 corrects the amount of the diagonally displaced position of the sheet P based on the detection results of the first CIS35 and the second CIS36 arranged on the upstream side of the sandwiching roller 31. The seat P is rotated from the reference position (the position corresponding to the normal position without any positional deviation in the diagonal direction) before the seat P is sandwiched, and then the seat P is rotated so as to return to the reference position. The reference position (the position corresponding to the normal position without the positional deviation in the width direction) before sandwiching the sheet P so as to correct the position deviation amount in the width direction of the sheet P based on the detection results of the 1CIS35 and the 2nd CIS36. After moving in the width direction from (.) To sandwich the sheet P, it moves in the width direction so as to return to the reference position (the first correction).

Then, the position deviation amount in the width direction and the diagonal direction of the sheet P after the position deviation amount in the width direction and the diagonal direction is corrected by the holding roller 31 is arranged so as to sandwich the holding roller 31 between the upstream side and the downstream side. It is detected by the second CIS36 and the third CIS37, and the amount of misalignment in the width direction and the diagonal direction of the sheet P is further corrected based on the detection result (“second correction (re-correction)”). ..
Specifically, the sandwiching roller 31 rotates from the above-mentioned reference position with the sheet P sandwiched so as to further correct the amount of the oblique positional deviation of the sheet P based on the detection results of the second CIS36 and the third CIS37. At the same time, the sheet P is moved in the width direction from the above-mentioned reference position while the sheet P is sandwiched so as to further correct the amount of the positional deviation in the width direction of the sheet P.

Based on the detection result before the sheet P is sandwiched by the sandwiching roller 31 in this way, the lateral resist correction and the skew correction are performed once while the sheet P is sandwiched and conveyed by the sandwiching roller 31, and then the second step is performed. Based on the detection results of the 3rd CIS 36 and 37, the lateral resist correction and the skew correction are performed again while sandwiching and transporting the sheet P by the sandwiching roller 31 when the sheet P rushes into the nip of the sandwiching roller 31. There is a possibility that the horizontal resist may be slightly misaligned or skewed due to the shock, and the lateral resist may be slightly misaligned or slanted when the roller portion of the sandwiching roller 31 is eccentric or has improper assembly. This is because there is a possibility that a line will be generated.
On the other hand, in the first embodiment, the lateral resist correction and the skew correction are once performed while the sheet P is sandwiched and conveyed by the sandwiching roller 31 based on the detection result before being sandwiched by the sandwiching roller 31. After that, based on the detection results of the second and third CIS 36 and 37 after being sandwiched by the sandwiching rollers 31, the lateral resist correction and the skew correction are performed again while sandwiching and transporting the sheet P by the sandwiching rollers 31. Therefore, the possibility as described above is limited, and the horizontal resist correction and the skew correction can be performed with higher accuracy.

Here, in the first embodiment, the detection results of the second and third CIS 36 and 37 that are continuously detected when the second and third CIS 36 and 37 function as the detection means for performing the second correction. The amount of misalignment in the width direction and the diagonal direction of the sheet P is corrected by feedback control based on the above. That is, in the second correction, the position information of the sheet P is detected moment by moment by the two CIS 36 and 37, respectively. Then, the position deviation amount in the width direction and the diagonal direction of the sheet P is calculated based on the position information and fed back to the control unit, and the position deviation correction amount (encoder count number) in the width direction and the diagonal direction of the sheet P is calculated. It is fixed every moment.
By performing feedback control in this way, it is possible to responsively correct the positional deviation of the seat P that occurs during the second correction, the correction error during the second correction, and the like, and the lateral resist correction with even higher accuracy. And skew correction can be performed.

Hereinafter, an example of the operation of the transfer device 30 configured as described above will be described in detail with reference to FIGS. 5 and 6.
5 (A1) to (C1) and 6 (A1) to (B1) are top views showing the operation of the transport device 30 in that order, and FIGS. 5 (A2) to 5 (C2). 6 (A2) to (B2) are side views of the transport device 30 corresponding to the operations of FIGS. 5 (A1) to (C1) and 6 (A1) to (B1), respectively.
First, as shown in FIGS. 5 (A1) and 5 (A2), the sheet P fed from the paper feeding unit 12 is sandwiched and conveyed toward the position of the sandwiching roller 31 by the third transport roller pair 44 ( Transport in the direction of the white arrow.) At this time, the position of the holding roller 31 in the rotation direction is at the first reference position (a regular position corresponding to the sheet P having no skew), and the position in the width direction is the second reference position (horizontal resist). It is a regular position corresponding to the seat P without any misalignment.).
Then, when the sheet P passes through the position of the first CIS35 and reaches the position of the second CIS36, the displacement amount α of the lateral resist of the sheet P is detected by the two CIS35s and 36s. Further, the skew amount β of the sheet P is detected by the two CIS 35 and 36.

After that, as shown in FIGS. 5 (B1) and 5 (B2), the holding roller 31 together with the holding member 72 has a shaft portion 71a in the same inclination direction according to the skew amount β detected by the first and second CIS 35 and 36. It rotates from the first reference position by an angle β around the center, and shifts from the second reference position by a distance α in the same width direction according to the position deviation amount α detected by the first and second CIS35 and 36.
Then, as shown in FIGS. 5 (C1) and 5 (C2), the rotational drive of the sandwiching roller 31 (rotational driving in the direction of the arrow in the figure) is started immediately before the tip of the sheet P reaches the sandwiching roller 31. When the sheet P is sandwiched and transported by the sandwiching roller 31, the third transport roller pair 44 opens the transport path and moves apart in the direction in which the sheet P is not sandwiched (in the direction of the solid arrow). The timing at which the tip of the seat P reaches the pinching roller 31 is the timing at which the tip of the seat P is detected by the CIS 35, 36, the transport speed of the seat P, and the position of the CIS 35, 36 to the position of the pinching roller 31. It can also be calculated by the calculation unit (control unit) based on the distance of.

Then, as shown in FIGS. 6 (A1) and 6 (A2), the holding roller 31 holds and conveys the sheet P, and shafts so as to cancel the skew amount β detected by the first and second CIS 35 and 36. It rotates around the portion 71a so as to return to the first reference position, and moves in the width direction so as to cancel the position deviation amount α detected by the first and second CIS35 and 36. To do.
Then, as shown in FIGS. 6 (B1) and 6 (B2), when the corrected seat P reaches the position of the third CIS 37, the skew amount β'of the seat P is continuously detected by the second and third CIS 36 and 37. Will be done. Further, the corrected sheet P is continuously detected by the second and third CIS 36 and 37 in the position deviation amount α'of the lateral resist of the sheet P. Then, the holding roller 31, together with the holding member 72, has an angle β ′ about the shaft portion 71a in a different inclination direction (reverse direction) according to the skew amount β ′ continuously detected by the second and third CIS 36 and 37. Only rotates from the first reference position, and the distance α'from the second reference position in different width directions (reverse direction) according to the amount of positional deviation α'continuously detected by the second and third CIS 36, 37. Shift move.
In this way, the sheet P is conveyed toward the transfer roller 7 (image forming portion) while the skew correction and the lateral resist correction are performed again every moment. At this time, the rotation speed of the sandwiching roller 31 (the transport speed of the sheet P until reaching the transfer roller 7) is changed so as to match the timing with the image on the photoconductor drum 5.

Then, as shown in FIGS. 6 (C1) and 6 (C2), the sheet P is conveyed toward the transfer roller 7 (image transfer unit), and the image is transferred to a desired position on the sheet P. .. Then, the third transport roller pair 44, which was in the separated state, is returned to the contact state (the state of FIG. 5 (A2)) to assist the transport of the sheet P by the holding roller 31, and then transport. The sheet P will be prepared for the transport operation.
After that, when the rear end of the sheet P passes the position of the sandwiching roller 31, the sandwiching roller 31 prepares for the skew correction and the lateral resist correction of the sheet P to be conveyed next, and the first reference position and the second reference position. Will be returned to.

Here, in the transport device 30 according to the first embodiment, the plurality of CIS 35 to 37 detect the adjustment reference plate 70 (adjustment reference member) arranged so as to face all of the plurality of CIS 35 to 37, respectively. As a result, "shading correction" that corrects the output voltage and "zero point alignment" that determines a reference photo sensor among the plurality of photo sensors are performed.
Specifically, as shown in FIGS. 7 to 9, the adjustment reference plate 70 is configured to be detachable from the image forming apparatus 1 (conveying apparatus 30). Then, at the time of manufacturing, when the sensitivity of a plurality of CIS is changed due to repeated use of the device by the user in the market, or when the CIS is replaced and maintained by a serviceman in the market, the worker As a result, "shading correction" and "zero point alignment" of the three CIS 35 to 37 are performed with one adjustment reference plate 70 mounted on the image forming apparatus 1 (conveying apparatus 30). Then, after the "shading correction" and the "zero point alignment" are performed, the adjustment reference plate 70 is removed from the image forming apparatus 1 (conveying apparatus 30).

Here, referring to FIG. 10, the "shading correction" of CIS35-37 changes the output voltage of CIS35-37 composed of a plurality of photosensors (appropriately referred to as "pixels") from a disjointed state to a smooth state. It means to correct to. The output (analog output) of CIS35 to 37 varies depending on the amount of light, sensitivity, lens characteristics, etc., which are different for each pixel. Shading correction is a process for canceling these effects. Specifically, by reading the reference white portion (in the first embodiment, the facing surface 70a2 of the adjustment reference plate 70) on the entire surface of the CIS, the output voltage at that time and the correction target can be obtained. The difference voltage between the output level to be output and the voltage difference is obtained and given as a correction voltage for each pixel so that the output voltage is smoothed.
By performing the shading correction of CIS 35 to 37 in this way, it is possible to reduce the detection error of CIS 35 to 37 that detects the side end portion of the sheet P. Then, by multiplying the inter-pixel pitch based on these values, it is possible to detect the position of the high-definition sheet P having linearity.

Further, the "zero point alignment" of CIS35 to 37 is for determining a photosensor that serves as a reference (the position of the side end portion of the ideal sheet P) among a plurality of photosensors. Also called "offset".
By aligning the zero points of CIS35-37 in this way, even if there is an error in the mechanical mounting position of CIS35-37 that detects the side end of the seat P, the misalignment correction with respect to the seat P can be performed. It can be done with high accuracy.

More specifically, with reference to FIG. 9, the adjustment reference plate 70 is formed by integrating a thin plate 70a having a plate thickness of about 0.5 mm with a base material 70b made of a metal material or a resin material and having a thickness and rigidity. It is the one that is held in the same way. The thin plate 70a is provided with an edge portion 70a1 extending linearly in parallel with the transport direction, and the facing surfaces 70a2 facing the plurality of CIS 35 to 37 are formed of a material having high light reflectance. In the first embodiment, as the thin plate 70a, a sheet (or a stainless steel plate coated in white) which is close to the thickness of the frequently used sheet P and is made of white PET (polyethylene terephthalate) is used. ing. Further, the thin plate 70a is attached to the base material 70b via double-sided tape so that the edge portion 70a1 protrudes. The edge portion 70a1 of the thin plate 70a is formed with high accuracy so that the straightness is within 10 μm in the transport direction. Further, as shown in FIGS. 7 and 8, the adjustment reference plate 70 is formed so that the length in the transport direction thereof is longer than the distance between the first CIS 35 and the third CIS 37 in the transport direction.

Then, as shown in FIG. 7A, the shading correction of CIS35-37 is performed by reading the output voltage of CIS35-37 with the facing surfaces 70a2 of the adjustment reference plate 70 facing each other with the plurality of CIS35-37. Is done.
In the present embodiment, in all of the three CIS 35 to 37, not the entire region in the width direction is used as the reading region, but a part of the region on one end side in the width direction is used as the reading use region M. It is used as a region that may substantially detect the side edge of the sheet P, and the other regions may be used as the reading unused area N to substantially detect the side edge of the sheet P. Absent. Then, in the present embodiment, as shown in FIG. 10, the output voltage of the CIS 35 to 37 is applied in a state where the white facing surface 70a2 of the adjustment reference plate 70 faces the reading and use area M of the plurality of CIS 35 to 37. By reading, shading correction of CIS35 to 37 (reading use area M) is performed. Specifically, for each of the three CIS 35 to 37, the outputs of the plurality of photo sensors are individually adjusted so that the outputs of the plurality of photo sensors installed in the reading use area M are made uniform. .. After that, based on the adjusted output, detection by CIS35 to 37 is performed, and based on the detection result, the horizontal resist correction and the skew correction described above are performed.

Further, as shown in FIG. 7B, the zero point alignment can be achieved by detecting the edge portion 70a with the CIS 35-37 in a state where the edge portion 70a1 of the adjustment reference plate 70 is opposed to the plurality of CIS 35-37. It is carried out.
In the present embodiment, the adjustment reference plate 70 is moved to one end side (upper in FIG. 7) in the width direction from the position of the adjustment reference plate 70 when shading correction is performed, and the CIS 35 to 37 is read. With the edge portion 70a1 of the adjustment reference plate 70 facing the center of the use area M, the photosensor (pixel) that detects the edge portion 70a1 at that time is placed at the reference position (at the target position without displacement). There is.) After that, detection by CIS35 to 37 is performed based on the determined reference position (zero point position), and the horizontal resist correction and skew correction described above are performed based on the detection result. ..

As described above, in the first embodiment, the adjustment reference plate 70 is detachably installed with respect to the main body of the transport device 30. Specifically, as shown in FIGS. 7 to 9, the adjustment reference plate 70 stands upright on the center side in the width direction of the main body side plate 60 which is a part of the housing of the transport device 30 (image forming device 1). It is detachably installed on the fixed portion 61 installed in the above. The fixing portions 61 are provided at positions (two locations) separated from each other in the transport direction.
Further, the adjustment reference plate 70 is formed with a plurality of first reference holes 70c and a plurality of second reference holes 70d. The first reference hole 70c and the second reference hole 70d are both in the transport direction at positions separated from each other in the transport direction (the left-right direction in FIGS. 7 and 8 and the vertical direction on the paper surface in FIG. 9). Two are arranged so as to be parallel to each other. Further, the two second reference holes 70d are formed at positions closer to the edge portion 70a1 than the two first reference holes 70c.

On the other hand, a plurality of positioning pins 61a are arranged at positions separated from each other in the transport direction on the main body of the transport device 30. Specifically, positioning pins 61a are formed on the two fixing portions 61 fixed to the main body side plate 60 so as to stand upward. The distance between the two positioning pins 61a in the transport direction is equivalent to the distance between the two first reference holes 70c in the transport direction, and is equivalent to the distance between the two second reference holes 70d in the transport direction. Further, the outer diameters of the two positioning pins 61a are equivalent to the hole diameters of the two first reference holes 70c and the same as the hole diameters of the two second reference holes 70d.

Then, as shown in FIGS. 7 (A) and 9 (A), the adjustment reference is such that the edge portion 70a1 faces the center side in the width direction (lower side of FIG. 7 and right side of FIG. 9). "Shading correction" is performed in a state where the posture of the plate 70 is determined, two first reference holes 70c are fitted to the two positioning pins 61a, and the adjustment reference plate 70 is fixed to the apparatus main body (fixing portion 61). It will be.
Further, as shown in FIGS. 7 (B) and 9 (B), the adjustment reference is such that the edge portion 70a1 faces the center side in the width direction (lower side of FIG. 7 and right side of FIG. 9). "Zero point alignment" is performed in a state where the posture of the plate 70 is determined, two second reference holes 70d are fitted to the two positioning pins 61a, and the adjustment reference plate 70 is fixed to the apparatus main body (fixing portion 61). It will be done.

In the first embodiment, the transport device 30 is configured as a unit that can be pulled out in the width direction with respect to the image forming device main body 1. Then, the adjustment reference plate 70 is attached to and detached from the transfer device 30 in a state where the transfer device 30 is pulled out from the image forming device main body 1 and exposed. Further, with the transport device 30 in which the adjustment reference plate 70 is set mounted on the image forming apparatus main body 1, shading correction and zero point alignment are performed on the three CIS 35 to 37. Therefore, when switching from shading correction to zero point alignment, the transport device 30 is pulled out from the image forming apparatus main body 1, and the adjustment reference plate 70 is manually moved from the position of FIG. 7 (A) to the position of FIG. 7 (B). It will be moved.
Further, it is preferable that the zero point alignment is performed after the output correction of CIS 35 to 37 is completed by the shading correction. That is, after the shading correction is performed, the zero point alignment is performed.

Further, in the first embodiment, as shown in FIG. 8, the adjustment reference plate 70 is configured to face the three CIS 35 to 37 via the linear transport guide plates 65 and 66. Therefore, the linear transport guide plates 65 and 66 prevent the incident light from the three CIS 35 to 37 on the adjustment reference plate 70 and the reflected light from the adjustment reference plate 70 to the three CIS 35 to 37. Window portions 65a and 66a that transmit light are formed so as not to be present.

As described above, in the transport device 30 according to the first embodiment, the adjustment reference plate 70 is arranged so as to face all three CIS 35 to 37, and shading correction and zero point alignment for the three CIS 35 to 37 can be performed. It is carried out. As a result, not only during manufacturing, but also when the user repeatedly uses the device in the market and the sensitivity of multiple CIS changes, or when a serviceman performs CIS replacement maintenance in the market, etc. Even so, shading correction and zero point alignment of the three CIS 35 to 37 can be performed efficiently and with high accuracy. Therefore, the accuracy of skew correction and lateral resist correction based on the detection results of the three CIS 35 to 37 can be improved.

In the first embodiment, the adjustment reference plate 70 is provided with the first reference hole 70c and the second reference hole 70d, and one adjustment reference plate 70 is used to correct shading and zero points of the three CIS 35 to 37. It is configured so that it can be aligned. On the other hand, an adjustment reference plate for shading correction and an adjustment reference plate for zero point alignment can be prepared separately. In that case, although the number of adjustment reference plates is increased as compared with that of the first embodiment, the effect of simultaneously performing shading correction and zero point alignment for the three CIS 35 to 37 is maintained. It will be.

<Modification example 1>
FIG. 11A is a schematic side view showing a state in which the facing surfaces 70a2 of the adjustment reference plate 70 as the first modification are set so as to face a plurality of CIS 35 to 37, and is a schematic side view of the first embodiment. It is a figure corresponding to FIG. 9A. Further, FIG. 11B is a schematic side view showing a state in which the edge portion 70a1 of the adjustment reference plate 70 is set so as to face the plurality of CIS 35 to 37, and is a schematic side view showing a state in which the edge portion 70a1 of the adjustment reference plate 70 faces the plurality of CIS 35 to 37. It is a figure corresponding to (B).
The adjustment reference plate 70 in the first modification is the one of the first embodiment in that the orientation in the width direction is reversed between when the shading correction is performed and when the zero point alignment is performed. Is different from.

As shown in FIG. 11, in the adjustment reference plate 70 in the first modification, a plurality of reference holes 70e (two reference holes) are formed at positions closer to the edge portion 70a1 than the central position in the width direction. ing. Two reference holes 70e are arranged at positions separated from each other in the transport direction.
Then, as shown in FIG. 11A, the posture of the adjustment reference plate 70 is determined so that the edge portion 70a1 faces the end side in the width direction (the left side in FIG. 11), and the two positioning pins 61a The "shading correction" is performed in a state where the adjustment reference plate 70 is fixed to the apparatus main body (fixing portion 61) by fitting the two reference holes 70e into the device.
Further, as shown in FIG. 11B, the posture of the adjustment reference plate 70 is determined so that the edge portion 70a1 faces the center side in the width direction (the right side in FIG. 11), and the two positioning pins 61a are used. "Zero point alignment" is performed in a state where the adjustment reference plate 70 is fixed to the apparatus main body (fixing portion 61) by fitting the two reference holes 70e.
Even in the case of such a configuration, the same effect as that of the first embodiment can be obtained. In particular, in the modified example 1, since there is only one type of reference hole formed in the adjustment reference plate 70 with improved position accuracy, the adjustment reference plate 70 is cheaper than that of the first embodiment. become.

As described above, in the transport device 30 according to the first embodiment, a plurality of CIS 35 to 37 installed at intervals in the transport direction are arranged so as to face all of the plurality of CIS 35 to 37, respectively. By detecting the adjustment reference plate 70, shading correction for correcting the output voltage and zero point alignment for determining a reference photosensor among a plurality of photosensors are performed.
As a result, shading correction and zero point alignment of a plurality of CIS 35 to 37 arranged side by side in the transport path can be performed efficiently and with high accuracy.

<Embodiment 2>
A second embodiment of the present invention will be described in detail with reference to FIGS. 12 and 13.
FIG. 12A is a schematic top view showing a state in which the adjustment reference plate 70 is moved to the first position, and FIG. 12B is a schematic top view showing a state in which the adjustment reference plate 70 is moved to the second position. 12 (C) is a schematic top view showing a state in which the adjustment reference plate 70 is moved to the third position. Further, FIG. 13A is a schematic side view showing a state in which the adjustment reference plate 70 is moved to the third position, and FIG. 13B is a schematic side view showing the state in which the adjustment reference plate 70 is moved from the third position to the center side in the width direction. It is a schematic side view which shows the state of doing.
In the transfer device 30 according to the second embodiment, the adjustment reference plate 70 is built in the transfer device 30, and the adjustment reference plate 70 is automatically moved to a desired position. It is different from the one of the first embodiment, which is manually and detachably installed in the above.

Similarly to that of the first embodiment, the transfer device 30 in the second embodiment also has a third transfer roller pair 44, a first CIS35, a second CIS36, a sandwiching roller 31, and a second along the transfer path of the sheet P. 3CIS37, is installed.

Here, unlike the one in the first embodiment, the transport device 30 in the second embodiment has the adjustment reference plate 70 built in in advance, and the shading correction is performed when the normal image forming process is performed. The adjustment reference plate 70 is configured to automatically move to the optimum position when the adjustment is performed and when the zero point alignment is performed.

Specifically, as shown in FIGS. 12 and 13, the adjustment reference plate 70 is in a posture in which the edge portion 70a1 faces the center side in the width direction (lower side in FIG. 12 and right side in FIG. 13). , It is configured to be movable in the width direction (the vertical direction in FIG. 12 and the horizontal direction in FIG. 13) by the moving mechanisms 67 to 69 controlled by the control unit 100.
Then, "shading correction" is performed in a state where the adjustment reference plate 70 is moved to the first position shown in FIG. 12A by the moving mechanisms 67 to 69. Further, in a state where the adjustment reference plate 70 is moved to the second position (the position shown in FIG. 12B) closer to the end side in the width direction than the first position by the moving mechanisms 67 to 69, the “zero point” is reached. "Alignment" is performed. Further, when "shading correction" and "zero point alignment" are not performed, the adjustment reference plate 70 is closer to the end side in the width direction than the second position by the moving mechanisms 67 to 69 and faces a plurality of CIS 35 to 37. It is moved to the third position (the position shown in FIG. 12C).

More specifically, as shown in FIGS. 12 and 13, the moving mechanism includes a shift motor 67 (pulse motor), a feed screw 68 (linear screw), an encoder 69, and the like.
The shift motor 67 is fixed to the main body side plate 60 via a pedestal. The motor shaft of the shift motor 67 is a feed screw 68, the tip of which is in contact with the end surface of the adjustment reference plate 70. An encoder 69 is installed in the shift motor 67 so that the amount of movement of the feed screw 68 (position in the width direction of the adjustment reference plate 70) can be grasped from the amount of rotation of the feed screw 68 rotationally driven by the shift motor 67. It is configured in.
On the other hand, the fixing portion 61 is provided with a main body side slider 61b so as to extend in the width direction. Further, the adjustment reference plate 70 is provided with a slider 70f (reference plate side slider) that engages with the main body side slider 61b of the fixing portion 61 so as to extend in the width direction. As a result, the adjustment reference plate 70 can slide and move in the width direction along the main body side slider 61b.
Further, the adjustment reference plate 70 and the main body side plate 60 are connected by a tension spring 80 as an urging member. As a result, the adjusting reference plate 70 is always in contact with the tip of the feed screw 68 due to the urging force of the tension spring 80.

With such a configuration, when the feed screw 68 is rotationally driven in the positive direction by the control of the shift motor 67 by the control unit 100, the adjustment reference plate 70 resists the urging force of the tension spring 80. Will be pushed toward the bottom of FIG. On the other hand, when the feed screw 68 is rotationally driven in the opposite direction by the control of the shift motor 67 by the control unit 100, the feed screw 68 moves upward in FIG. The urging force of 80 causes the feed screw 68 to be moved upward in FIG. 12 while maintaining the contact state with the lead screw 68.
In this way, the adjustment reference plate 70 is moved to a desired position in the width direction by the moving mechanisms 67 to 69, and "shading correction" and "zero point alignment" are performed. Further, when shading correction or zero point alignment is not performed, the adjustment reference plate 70 is moved to a third position not facing the three CIS 35 to 37 by the moving mechanisms 67 to 69, so that the adjustment is performed in a normal image forming process. The reference plate 70 does not affect the detection of the sheet P by the three CIS 35-37.

As described above, in the second embodiment, the adjustment reference plate 70 moves so as to face all three CIS 35 to 37, and shading correction and zero point alignment are performed on the three CIS 35 to 37. Similar to the first embodiment, shading correction and zero point alignment of the three CIS 35 to 37 can be performed efficiently and with high accuracy. In particular, in the second embodiment, the adjustment reference plate 70 is built in the image forming apparatus main body 1 (conveying apparatus 30), and the operation panel (installed on the exterior portion of the image forming apparatus main body 1) is operated. Since it is configured so that it can be automatically moved to a desired position, the workability of shading correction and zero point alignment is further improved.

Here, in the transport device 30 according to the second embodiment, as shown in FIG. 13 (A), the adjustment reference plate 70 is at the third position (positions shown in FIGS. 12 (C) and 13 (A)). A cover member 85 is provided to cover at least the edge portion 70a1 and the facing surface 70a2 when the position is located at.).
Specifically, the cover member 85 is fixedly installed on the main body of the apparatus so as to cover the entire upper portion of the adjustment reference plate 70 located at the third position.
As a result, in the normal state where shading correction and zero point alignment are not performed, when the adjustment reference plate 70 is retracted to the third position, the toner floating in the device or the toner floating in the device on the edge portion 70a1 or the facing surface 70a2 This will reduce the problem of foreign matter such as paper dust adhering. Therefore, it is possible to prevent a problem that shading correction and zero point alignment are performed in a state where foreign matter is attached to the edge portion 70a1 and the facing surface 70a2, and the accuracy thereof is lowered.

Further, in the transport device 30 according to the second embodiment, as shown in FIG. 13B, when the adjustment reference plate 70 moves from the third position to the center side in the width direction, at least the edge portion 70a1 and the surface facing the edge portion 70a1 A cleaning member 86 for cleaning the 70a2 is provided.
Specifically, the cleaning member 86 is composed of a flocking brush, a rubber blade, or the like, and is installed so as to protrude downward from the end surface of the cover member 85 and come into contact with the edge portion 70a1 and the facing surface 70a2.
As a result, when the adjustment reference plate 70 moves from the third position to the center side in the width direction, or when the adjustment reference plate 70 moves from the center side in the width direction to the third position, the cleaning member 86 moves to the edge portion 70a1 or the opposite side. The foreign matter adhering to the edge portion 70a1 and the facing surface 70a2 is removed by sliding contact with the surface 70a2. Therefore, it is possible to prevent a problem that shading correction and zero point alignment are performed in a state where foreign matter is attached to the edge portion 70a1 and the facing surface 70a2, and the accuracy thereof is lowered.
In addition, in order to obtain the cleaning effect as described above more reliably, the adjustment reference plate 70 is moved from the third position at a predetermined timing (for example, the timing immediately before shading correction or zero point alignment is performed). The reciprocating movement of moving to the center side in the width direction and returning to the third position may be repeated.

Further, in the second embodiment, the moving mechanisms 67 to 69 move the adjustment reference plate 70 at a predetermined timing at the time of non-image formation in which the image forming process is not performed, and perform shading correction and zero point alignment. It is controlled by the control unit 100 so as to be used.
Specifically, in the second embodiment, the start-up operation after the image forming apparatus 1 has stopped operating for more than a predetermined time, or after the image forming process (printing operation) has not been performed for more than a predetermined time. The adjustment reference plate 70 is moved from the third position to the first position or the second position by the moving mechanisms 67 to 69 to perform shading correction and zero point alignment of the three CIS 35 to 37 during the start-up operation of the three CIS 35 to 37. Is done.
As a result, highly accurate detection by CIS35 to 37 is performed even over time, and highly accurate lateral resist correction and skew correction are performed based on the detection result.

Here, in the second embodiment, a sheet having a light reflectance exceeding a predetermined value (a normal sheet P having a high degree of whiteness) is conveyed, and a sheet having a light reflectance not exceeding a predetermined value (a sheet P having a high whiteness) is transported. A black sheet P or a sheet P close to black) is transported, and when shading correction or zero point alignment is not performed, control can be performed as follows.
When the shading correction and the zero point alignment are not performed and the sheet P whose light reflectance exceeds the predetermined value A is conveyed, the adjustment reference plate 70 is moved to the third position by the moving mechanisms 67 to 69. .. On the other hand, when the shading correction and the zero point alignment are not performed and the sheet P whose light reflectance does not exceed the predetermined value A is conveyed, the adjustment reference plate 70 is moved by the moving mechanisms 67 to 69. It is moved to the first position (the position shown in FIG. 12A).
Such control is performed by CIS35 to 37 at the side end portion of the sheet P because the light reflectance of the surface of the sheet P which is black or close to black is low in the normal image forming process. This is because it is difficult to detect optically. On the other hand, when the black or near sheet P is passed through, the adjustment reference plate 70 is positioned at the first position so that the white facing surface 70a2 located below the side end of the sheet P can be used. The reflected light of the sheet P makes it easier to optically detect the side end portion of the sheet P with CIS 35 to 37.
As a result, even when a black sheet P or a sheet P close to it is passed through the paper, highly accurate detection is performed by CIS35 to 37, and based on the detection result, highly accurate lateral resist correction and skew correction are performed. Will be done.

<Modification 2>
FIG. 14 is a schematic top view showing a state in which the adjustment reference plate 70 is moved to the third position in the transport device 30 in the second modification, and is a view corresponding to FIG. 12 (C) in the second embodiment. .. Further, FIG. 15A is a schematic side view showing a state in which the adjustment reference plate 70 is moved to the third position, and FIG. 15B is a state in which the adjustment reference plate 70 is rotated from the third position. It is a schematic side view which shows.
In the transport device 30 in the second modification, when the adjustment reference plate 70 is moved to the third position by the moving mechanisms 67 to 69, the facing surfaces 70a2 (thin plate 70a) are parallel to each other in the horizontal direction by the rotating mechanisms 92 to 94. It differs from that of the second embodiment in that the adjustment reference plate 70 is rotated so as to be parallel to the vertical direction from the state.

Specifically, as shown in FIGS. 14 and 15, in the transport device 30 in the second modification, the main body side slider 61b with which the slider 70f of the adjustment reference plate 70 is engaged is the adjustment reference plate 70, the moving mechanisms 67 to 69, and the like. Together with the cover member 85 (and the cleaning member 86), the cover member 85 (and the cleaning member 86) is rotatably held with respect to the fixing portion 61 (the main body of the transport device 30) via the rotating shaft 90.
A worm wheel 91 is installed at the end of the rotating shaft 90. On the other hand, a rotation motor 92 (pulse motor) is fixedly provided on the main body side plate 60. A worm gear 93 that meshes with the worm wheel 91 is installed on the motor shaft of the rotary motor 92. Further, an encoder 94 is installed in the rotary motor 92, and the amount of rotation of a rotating portion such as the adjustment reference plate 70 is calculated from the amount of rotation of the worm gear 93 (worm wheel 91) that is rotationally driven by the rotary motor 92. It is configured so that the posture in the rotation direction of the adjustment reference plate 70) can be grasped.

With such a configuration, in the second modification, when the worm gear 93 is rotationally driven in the positive direction by the control of the rotary motor 92 by the control unit 100, the adjustment reference plate 70 is moved from the horizontal state of FIG. 15 (A). It is rotated clockwise around the rotation shaft 90, and is in a substantially upright state as shown in FIG. 15B. On the other hand, when the worm gear 93 is rotationally driven in the opposite direction by the control of the rotary motor 92 by the control unit 100, the adjustment reference plate 70 is centered on the rotary shaft 90 from the upright state shown in FIG. 15 (B). It is rotated counterclockwise to reach the horizontal state shown in FIG. 15 (A).

As described above, in the modification 2, when the shading correction and the zero point alignment are not performed, the adjustment reference plate 70 (opposing surface 70a2) is parallel to the vertical direction with the edge portion 70a1 facing downward. Therefore, even if foreign matter adheres to the facing surface 70a2 or the edge portion 70a1, the foreign matter falls downward by its own weight and the foreign matter on the facing surface 70a2 or the edge portion 70a1 is removed. Therefore, even over time, high-precision detection by CIS35-37 is performed, and high-precision lateral resist correction and skew correction are performed based on the detection result.
Further, the position shown in FIG. 15B is also a position where the adjustment reference plate 70 is rotated so as not to face the three CIS 35 to 37, so that the main body side plate 60 and the three CIS 35 to 37 are not opposed to each other. Even if the distance between the two is short in the width direction, it is possible to form a state in which the adjustment reference plate 70 does not face the three CIS 35 to 37.

As described above, in the transport device 30 according to the second embodiment, the plurality of CIS 35 to 37 installed in the transport direction are all of the plurality of CIS 35 to 37, respectively, as in the case of the first embodiment. By detecting the adjustment reference plate 70 arranged so as to face the subject, shading correction for correcting the output voltage and zero point alignment for determining a reference photosensor among a plurality of photosensors are performed.
As a result, shading correction and zero point alignment of a plurality of CIS 35 to 37 arranged side by side in the transport path can be performed efficiently and with high accuracy.

In each of the above embodiments, the present invention has been applied to the transfer device 30 in which the sandwiching roller 31 that functions as the lateral resist / skew correction roller also functions as the resist roller, but the present invention can be applied. The transfer device is not limited to this, and even if the transfer device has other configurations, the present invention naturally applies to all the transfer devices having a plurality of CIS installed. Can be applied. For example, the present invention can naturally be applied to a transfer device in which a resist roller is installed on the downstream side of a sandwiching roller 31 that functions as a lateral resist / skew correction roller.
Further, in each of the above-described embodiments, the present invention is applied to the transport device 30 that performs skew correction and lateral resist correction of the transfer paper as the sheet P on which the image is formed, but the skew of the original document as the sheet P is applied. As long as a plurality of CIS are installed, the present invention can be naturally applied to a transfer device that performs line correction and horizontal resist correction.
Further, in each of the above-described embodiments, the present invention is applied to the transfer device 30 installed in the monochrome image forming device 1, but naturally the present invention is also applied to the transfer device installed in the color image forming device 1. The invention can be applied.
Further, in each of the above-described embodiments, the present invention is applied to the transport device 30 installed in the electrophotographic image forming apparatus 1, but the application of the present invention is not limited to this, and other methods are not limited to this. Even if it is a transport device installed in an image forming device (for example, an inkjet image forming device, an offset printing machine, etc.), all of them are as long as they are transport devices in which a plurality of CIS are installed. As a matter of course, the present invention can be applied to the transport device of the above.
And even in such a case, the same effect as in each of the above-described embodiments can be obtained.

Further, in each of the above-described embodiments, the present invention is applied to the transport device 30 in which three CIS 35 to 37 are installed, but the transport device in which two or four or more CIS are installed is used. Of course, the present invention can be applied.
And even in such a case, the same effect as in each of the above-described embodiments can be obtained.

It should be noted that the present invention is not limited to each of the above-described embodiments, and within the scope of the technical idea of the present invention, each of the above-described embodiments may be appropriately modified in addition to those suggested in the above-described embodiments. Is clear. Further, the number, position, shape, etc. of the constituent members are not limited to each of the above-described embodiments, and the number, position, shape, etc. suitable for carrying out the present invention can be used.

In the present application, the "width direction" is defined as a direction orthogonal to the sheet conveying direction.
Further, in the present application, the term "sheet" is defined to include all sheet-shaped recording media such as coated paper, label paper, transparencies, and films, in addition to ordinary paper.

1 Image forming apparatus (image forming apparatus main body),
7 Transfer roller (downstream transfer roller),
30 Conveyor,
31 Holding rollers (horizontal resist / skew correction roller, resist roller),
35 1st CIS (CIS),
36 Second CIS (CIS),
37 Third CIS (CIS),
60 body side plate,
61 Fixed part,
61a positioning pin,
61b Body side slider,
67 Shift motor (movement mechanism),
68 Feed screw (movement mechanism),
70 Adjustment reference plate (adjustment reference member),
70a thin plate,
70a1 edge part, 70a2 facing surface,
70b base material,
70c 1st reference hole, 70d 2nd reference hole,
70e reference hole,
70f slider,
80 Tension spring (biasing member),
85 cover member,
86 Cleaning member,
90 rotating shaft,
91 worm wheel,
92 Rotating motor (rotating mechanism),
93 Worm gear (rotation mechanism),
P sheet (recording medium).

Japanese Unexamined Patent Publication No. 2016-175776

Claims (12)

A transport device that transports sheets in a transport path.
A plurality of CIS having a plurality of photosensors arranged side by side in the width direction and detecting sheets transported in a predetermined transport direction in the transport path are installed in the transport direction.
The plurality of CIS have shading correction for correcting the output voltage by detecting adjustment reference plates arranged so as to face all of the plurality of CIS, and a photo sensor as a reference among the plurality of photo sensors. and zero point alignment defining a cracking Gaokona,
The adjustment reference plate includes an edge portion extending linearly in parallel with the transport direction, and has facing surfaces facing the plurality of CIS.
The shading correction was performed by reading the output voltage in a state where the facing surfaces of the adjustment reference plates were opposed to the plurality of CIS, and the edge portions of the adjustment reference plates were opposed to the plurality of CIS. A transport device characterized in that the zero point alignment is performed by detecting the edge portion in a state. The adjustment reference plate according to claim 1, wherein a thin plate having the facing surface made of a material having a high light reflectance is integrally held by a rigid base material. Conveyor device. The adjustment reference plate is
It is installed so that it can be attached to and detached from the main body of the transfer device.
A plurality of first reference holes arranged at positions separated from each other in the transport direction,
A plurality of second reference holes formed at positions closer to the edge portion than the plurality of first reference holes and arranged at positions distant from each other in the transport direction.
Equipped with
The posture of the adjustment reference plate is determined so that the edge portion faces the center side in the width direction, and the plurality of first reference holes are fitted into a plurality of positioning pins arranged at positions distant from each other in the transport direction in the apparatus main body. The shading correction is performed in a state where the adjustment reference plate is fixed to the main body of the apparatus.
The posture of the adjustment reference plate is determined so that the edge portion faces the center side in the width direction, and the plurality of second reference holes are fitted to the plurality of positioning pins to fix the adjustment reference plate to the apparatus main body. The transport device according to claim 1 or 2 , wherein the zero point alignment is performed in this state. The adjustment reference plate is
It is installed so that it can be attached to and detached from the main body of the transfer device.
It is provided with a plurality of reference holes formed at a position closer to the edge portion than the central position in the width direction and arranged at positions separated from each other in the transport direction.
The posture of the adjustment reference plate is determined so that the edge portion faces the end portion side in the width direction, and the plurality of reference holes are fitted into a plurality of positioning pins arranged at positions separated in the transport direction in the apparatus main body. The shading correction is performed in a state where the adjustment reference plate is fixed to the apparatus main body.
A state in which the posture of the adjustment reference plate is determined so that the edge portion faces the center side in the width direction, the plurality of reference holes are fitted into the plurality of positioning pins, and the adjustment reference plate is fixed to the apparatus main body. The transport device according to claim 1 or 2 , wherein the zero point alignment is performed. The adjustment reference plate is configured to be movable in the width direction by a movement mechanism controlled by the control unit in a posture in which the edge portion faces the center side in the width direction.
The shading correction is performed in a state where the adjustment reference plate is moved to the first position by the moving mechanism.
The zero point alignment is performed in a state where the adjustment reference plate is moved to a second position closer to the end side in the width direction than the first position by the moving mechanism.
When the shading correction and the zero point alignment are not performed, the adjustment reference plate is moved to a third position which is closer to the end side in the width direction than the second position and does not face the plurality of CIS by the moving mechanism. The transport device according to claim 1 or 2 , wherein the transfer device is characterized by being used. The adjustment reference plate is configured to be movable in the width direction by a movement mechanism controlled by the control unit in a posture in which the edge portion faces the center side in the width direction.
The shading correction is performed in a state where the adjustment reference plate is moved to the first position by the moving mechanism.
The zero point alignment is performed in a state where the adjustment reference plate is moved to a second position closer to the end side in the width direction than the first position by the moving mechanism.
When the shading correction and the zero point alignment are not performed and the sheet whose light reflectance exceeds a predetermined value is conveyed, the adjustment reference plate is moved in the width direction from the second position by the moving mechanism. Moved to a third position that is close to the end side and does not face the plurality of CIS
When the shading correction and the zero point alignment are not performed and the sheet whose light reflectance does not exceed the predetermined value is conveyed, the adjustment reference plate is moved to the first position by the moving mechanism. The transport device according to claim 1 or 2 , wherein the transfer device is characterized by being used. The transport device according to claim 5 or 6, further comprising a cover member that covers at least the edge portion and the facing surface when the adjustment reference plate is located at the third position. The transport according to any one of claims 5 to 7, wherein a cleaning member for cleaning at least the edge portion and the facing surface when the adjustment reference plate moves from the third position is provided. apparatus. When the adjustment reference plate is moved to the third position by the movement mechanism, the adjustment reference plate is moved from a state in which the facing surfaces are parallel in the horizontal direction to a state in which the facing surfaces are parallel in the vertical direction by the rotation mechanism. The transport device according to any one of claims 5 to 8, wherein the transport device is rotated. The claim is characterized in that the moving mechanism is controlled by the control unit so that the adjustment reference plate is moved at a predetermined timing at the time of non-image formation to perform the shading correction and the zero point alignment. Item 5. The transport device according to any one of claims 5 to 9. The plurality of CIS are provided with a holding roller that is rotationally driven by a driving means and conveys the sheet in a state of sandwiching the sheet. The plurality of CIS includes a first CIS disposed upstream of the conveying path with respect to the sandwiching roller, and the sandwiching roller. The second CIS, which is on the upstream side of the transport path and is disposed on the downstream side of the transport path with respect to the first CIS, and the second CIS, which is disposed on the downstream side of the transport path with respect to the holding roller. With the 3rd CIS,
The sandwiching roller was rotated from a reference position to sandwich the sheet before sandwiching the sheet so as to correct the amount of oblique positional deviation of the sheet based on the detection results of the first CIS and the second CIS. After that, it rotates so as to return to the reference position, and from the reference position before sandwiching the sheet so as to correct the amount of positional deviation in the width direction of the sheet based on the detection results of the first CIS and the second CIS. After moving in the width direction and sandwiching the sheet, the sheet is moved in the width direction so as to return to the reference position.
The diagonal and width positional deviations of the sheet after the diagonal and width positional deviations have been corrected by the sandwiching rollers are detected by the second CIS and the third CIS, and the detection results are used as the basis for the detection results. Any of claims 1 to 10, wherein the sandwiching roller rotates from the reference position and moves in the width direction so that the amount of positional deviation in the oblique direction and the width direction of the sheet is further corrected. The transport device described in. An image forming apparatus comprising the conveying apparatus according to any one of claims 1 to 11.

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