JP7037745B2 - Conveyor device, image forming device - Google Patents

Description

The present invention relates to a transport device and an image forming device.

In a transport device for transporting a sheet, positional deviation such as skewing of the sheet or displacement in the width direction during transport becomes a problem. For example, in an image forming apparatus that forms an image on a recording medium, there is a problem that the image position formed on the recording medium is deviated from the ideal position due to the positional deviation during transportation of the recording medium.

Further, it is provided with a detection mechanism for detecting such a misalignment of the sheet and a holding roller for correcting the misalignment of the sheet based on the detection result by the detection mechanism, and the misalignment of the sheet is corrected while the sheet is conveyed by the pinching roller. An amended invention has already been made (for example, Patent Document 1). Further, in the transport device disclosed in Patent Document 2 and Patent Document 3, the sandwiching roller corrects the position deviation of the sheet for the first time based on the detection result of the detection mechanism provided on the upstream side, and then the downstream side. Based on the detection result of the detection mechanism provided in the above, the holding roller corrects the misalignment of the seat again. By performing the re-correction operation in this way, it is possible to correct the misalignment of the sheet with high accuracy while transporting the sheet.

When performing the sheet position deviation correction operation and the re-correction operation while transporting the sheet as in Patent Documents 2 and 3, if the correction amount at the time of re-correction is large, the correction is completed before the sheet passes. There is a problem that it becomes difficult to do so and the accuracy of the sheet position deviation correction is adversely affected.

From such a problem, it is an object of the present invention to provide a transport device capable of reducing the correction amount at the time of re-correction operation and correcting the misalignment of the sheet with high accuracy.

In order to solve the above problems, the present invention is provided with a correction member for correcting the position deviation of the sheet, an upstream side detection mechanism for detecting the position deviation of the sheet, and a downstream side of the upstream side detection mechanism in the sheet transport direction. A transport device having a downstream side detection mechanism for detecting the positional deviation of the sheet and a control unit for controlling the correction operation of the correction member, wherein the control unit is the one detected by the downstream side detection mechanism. The average position deviation amount obtained by averaging the position deviation amounts of the sheets for the plurality of the sheets is stored, and the control unit causes the correction member to have at least the detection result of the upstream detection mechanism and the average position deviation amount. Based on the above, a correction operation for correcting the position deviation of the sheet is performed, and a re-correction operation for correcting the position deviation of the sheet again based on at least the detection result of the downstream side detection mechanism is performed, respectively, and the upstream By moving or attaching / detaching at least one of the side detection mechanism and the downstream side detection mechanism, the set average position deviation amount is initialized, and the position deviation amount is newly stored from the subsequent sheet transfer to store the average position. It is characterized by calculating the amount of deviation .

In the present invention, the sheet is pre-corrected based on the average position deviation amount before the re-correction operation. As a result, a part of the detection error that occurs between the position deviation detection during the correction operation and the position deviation detection during the subsequent correction operation can be corrected in advance. Therefore, the correction amount at the time of the re-correction operation can be reduced, and the position deviation of the sheet can be corrected with high accuracy.

It is a schematic block diagram of an image forming apparatus. It is a figure which shows the transporting apparatus which concerns on this embodiment, (a) is a plan view, (b) is a side view. It is a figure which shows each operation of the transfer apparatus which concerns on this embodiment. It is a figure which shows each operation of the transfer apparatus which concerns on this embodiment. It is a figure which shows each operation of the transfer apparatus which concerns on this embodiment. It is a figure which shows each operation of the transfer apparatus which concerns on this embodiment. It is a figure which shows each operation of the transfer apparatus which concerns on this embodiment. It is a figure which shows each operation of the transfer apparatus which concerns on this embodiment. It is a figure which shows the method of calculating the skew amount of a paper. It is a flow chart which shows each operation of a transfer device. It is a figure which shows the locus of movement of a holding roller. It is a figure which shows the locus of movement of a holding roller. It is a block diagram which shows the structure of the control part of a transport device. It is sectional drawing which shows the holding roller and its peripheral structure. FIG. 14 is a plan view taken along the line bb of FIG. It is a figure which shows the width direction movement operation of a roller holding member, and the rotation operation in a transport surface. It is a figure which shows the movement amount Δy in the width direction of a roller holding member, and the rotation amount Δx in a transport surface. It is a schematic block diagram which shows the image forming apparatus of a different embodiment.

Hereinafter, embodiments according to the present invention will be described 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.

The color image forming apparatus 1 shown in FIG. 1 is provided with an image forming unit 2 to which four process units 9Y, 9M, 9C, and 9Bk are detachably provided. Each process unit 9Y, 9M, 9C, 9Bk accommodates developers of different colors of yellow (Y), magenta (M), cyan (C), and black (Bk) corresponding to the color separation components of the color image. It has the same configuration except that it is.

Specific process units 9 include a photoconductor drum 10 which is a drum-shaped rotating body capable of supporting toner as a developer on the surface, and a charging roller 11 which uniformly charges the surface of the photoconductor drum 10. It also includes a developing device 12 that supplies toner to the surface of the photoconductor drum 10, a cleaning device, and the like.

An exposure unit is arranged above the process unit 9. The exposed unit is configured to emit laser light based on the image data.

The transfer unit 4 is arranged directly below the image-creating unit 2. The transfer unit 4 includes a drive roller 13, a secondary transfer facing roller 15, a plurality of tension rollers, an endless intermediate transfer belt 16 stretched by these rollers so as to be able to travel around, and a photoconductor drum of each process unit 9. It is composed of primary transfer rollers 17 and the like arranged at positions facing the intermediate transfer belt 16 with respect to 10. Each primary transfer roller 17 presses the inner peripheral surface of the intermediate transfer belt 16 at each position, and a primary transfer nip is formed at a position where the pressed portion of the intermediate transfer belt 16 and each photoconductor drum 10 come into contact with each other. Has been done.

Further, the drive roller 13 of the intermediate transfer belt 16 and the secondary transfer roller 18 are arranged at positions facing the drive roller 13 with the intermediate transfer belt 16 interposed therebetween. The secondary transfer roller 18 presses the outer peripheral surface of the intermediate transfer belt 16, and a secondary transfer nip is formed at a position where the secondary transfer roller 18 and the intermediate transfer belt 16 come into contact with each other.

The paper feed unit 5 is located at the lower part of the image forming apparatus 1, and is a paper feed cassette 19 as a sheet loading unit that accommodates the paper P as a sheet, and a paper feed roller that carries out the paper P from each paper feed cassette. It consists of 20 mag.

The transport path 6 is a transport path for transporting the paper P carried out from the paper feeding unit 5. A plurality of transport roller pairs are appropriately arranged on the transport path 6 up to the paper ejection portion described later.

On the transport path 6, on the downstream side in the paper transport direction from the paper feed unit 5, and on the upstream side from the secondary transfer nip position, the misalignment of the paper P on the transport path 6 is corrected, and the paper P is moved to the downstream side. A transport device 30 for transport is provided.

The fixing device 7 has a fixing roller 22 heated by a heating source, a pressure roller 23 capable of pressurizing the fixing roller 22, and the like.

The paper ejection unit is provided at the most downstream side of the transport path 6 of the image forming apparatus 1.

Hereinafter, the basic operation of the image forming apparatus 1 will be described with reference to FIG.

When the image forming operation is started in the image forming apparatus 1, an electrostatic latent image is formed on the surface of the photoconductor drum 10 of each process unit 9Y, 9C, 9M, 9Bk. The image information exposed by the exposure unit 3 on each photoconductor drum 10 is monochromatic image information obtained by decomposing a desired full-color image into yellow, cyan, magenta, and black color information. An electrostatic latent image is formed on each photoconductor drum 10, and the toner stored in each developing device is supplied to the photoconductor drum 10 by a drum-shaped developing roller, so that the electrostatic latent image is visualized. It is visualized as a toner image (developer image).

In the transfer unit 4, the intermediate transfer belt 16 is driven to travel in the direction of the arrow A1 in the figure by the rotational drive of the drive roller 13. Further, a constant voltage or a constant current controlled voltage having a polarity opposite to the charging polarity of the toner is applied to each primary transfer roller 17. As a result, a transfer electric field is formed at the primary transfer nip, and the toner images formed on each photoconductor drum 10 are sequentially superimposed and transferred on the intermediate transfer belt 16 at the primary transfer nip. As described above, for example, the image forming unit 2, the exposure unit, the transfer unit 4, and the like function as an image forming unit that forms an image on the paper P.

On the other hand, when the image forming operation is started, in the lower part of the image forming apparatus 1, the paper feeding roller 20 of the paper feeding unit 5 is rotationally driven, so that the paper P accommodated in the paper feeding cassette 19 is moved to the transport path 6. Be sent out.

The paper P sent out to the transport path 6 is transported to the downstream side by the transport device 30 and the roller pair on the transport path 6, and the misalignment is corrected by the transport device 30, so that the secondary transfer roller 18 and the secondary transfer roller 18 are secondary. It is sent to the secondary transfer nip formed between the transfer facing roller 15. At this time, a transfer voltage having a polarity opposite to the toner charging polarity of the toner image on the intermediate transfer belt 16 is applied, and a transfer electric field is formed in the secondary transfer nip. The toner image on the intermediate transfer belt 16 is collectively transferred onto the paper P by the transfer electric field formed in the secondary transfer nip.

The paper P on which the toner image is transferred is conveyed to the fixing device 7, and the paper P is heated and pressed by the fixing roller 22 and the pressure roller 23 to fix the toner image on the paper P. Then, the paper P on which the toner image is fixed is separated from the fixing roller 22 and conveyed to the downstream paper ejection unit, and is ejected to the outside of the apparatus.

The above description is an image forming operation when forming a full-color image on paper P, but a single-color image can be formed by using any one of four process units 9Y, 9C, 9M, and 9Bk. It is also possible to use two or three process units 9 to form a two-color or three-color image.

As shown in FIGS. 2 (a) and 2 (b), the transport device 30 is a transport roller 31 for transporting the paper P, a holding roller (correction member) 32, and a first CIS (upstream) for detecting the paper P. It has a side detection mechanism) 34, a second CIS (detection mechanism) 35, and a third CIS (downstream side detection mechanism) 36. A secondary transfer roller 18 is provided on the downstream side of the sandwiching roller 32. Hereinafter, the transport direction of the paper P is simply referred to as a transport direction, and the upstream side and the downstream side in the transport direction are also simply referred to as an upstream side and a downstream side. Further, the width direction of the paper P is also simply referred to as the width direction.

The transport roller 31 and the pinching roller 32 are transport members composed of a pair of rollers, and the paper P is transported to the downstream side by rotationally driving each roller with the paper P sandwiched between the nip portions of the rollers. can do.

The sandwiching roller 32 is provided so as to be rotatable in the transport surface of the paper P and movable in the width direction (see the arrow in FIG. 2a). By these operations, the sandwiched paper P can be rotated or moved in the width direction, and the skewing or the positional deviation in the width direction of the paper P can be corrected. Hereinafter, with respect to the sandwiching roller 32, the rotation of the roller for transporting the paper P is simply referred to as the rotation, and the rotation for skew correction is described as the rotation in the paper transport surface to distinguish them.

The first CIS34, the second CIS35, and the third CIS36 are contact image sensors in which a plurality of photosensors composed of a light emitting element such as an LED and a light receiving element such as a photodiode are arranged side by side in the width direction of the paper P. ..

The first CIS 34 and the second CIS 35 are provided on the downstream side of the transport roller 31 and on the upstream side of the sandwiching roller 32. Further, the third CIS 36 is provided on the downstream side of the holding roller 32.

Next, the process of correcting the positional deviation while transporting the paper P by the transport device 30 will be described with reference to FIGS. 3 to 9 and the flow chart of FIG.

As shown in FIGS. 3A and 3B, the paper P is conveyed by the transfer roller 31 and reaches the first CIS34 and then the second CIS35 (step S1 in FIG. 10). Then, these CIS detect the amount of skew of the paper P and the amount of positional deviation in the width direction (step S2).

An example of a specific method for calculating the amount of skew of the paper P1 and the amount of positional deviation in the width direction will be described with reference to FIG.
As shown in FIG. 9, the first CIS34 and the second CIS35 can detect the boundary between the paper portion and the non-paper portion, and can detect the side edge Pa of the paper P. Specifically, the first CIS34 can detect the widthwise position L1 of the point Pa1, and the second CIS35 can detect the widthwise position L2 of the point Pa2. The amount of positional deviation of the paper P in the width direction can be obtained, for example, by averaging the width direction position L1 and the width direction position L2. Further, the inclination angle (inclination amount) θ of the paper P1 is determined by using the distance M between the first CIS34 and the second CIS35 in the transport direction.
TANθ = (L1-L2) / M ... (1)
It can be expressed as. The skew amount of the paper P can be obtained by this equation (1). The amount of positional deviation of the paper P in the width direction can be detected by one CIS, and for example, the detection may be performed at the position shown in FIG.

Then, as shown in FIGS. 4 (a) and 4 (b), the holding roller 32 performs the picking operation with the detected amount of skew of the paper P and the amount of positional deviation in the width direction as the correction amount (step S2). , S5). The pick-up operation is an operation of moving from the reference position in the skewing direction of the paper P1 and in the position deviation direction in the width direction by the amount of the position deviation. In other words, it is an operation in which the holding roller 32 moves so that it can be received in a state of facing the misaligned paper P1. Further, the reference position of the holding roller 32 is a position arranged orthogonally to the conveying direction of the paper P (see FIG. 3a). It is assumed that the average position deviation amount described later is not set in the correction operation this time (step S3), and the details of the average position deviation amount will be described later.

As shown in FIGS. 5A and 5B, when the paper P reaches the pinching roller 32, the paper P is pinched and further downstream is conveyed (step S6). Further, the transport roller 31 on the upstream side is separated from the paper P.

As shown in FIGS. 6 (a) and 6 (b), the sandwiching roller 32 conveys the paper P and corrects the misalignment of the paper P by rotation and movement in the width direction in the transport surface. The operation is performed (step S7). This return operation is performed until the paper P reaches the third CIS36 downstream. The pinching roller 32 moves to the reference position by the return operation.

Next, as shown in FIGS. 7A and 7B, when the paper P reaches the third CIS36 (step S8), the skew amount and the width direction of the paper P are increased by the second CIS35 and the third CIS36. The amount of misalignment is detected again (step S9). The method for detecting the amount of misalignment is the same as the detection method by the first CIS34 and the second CIS35. Further, the first position deviation amount detected by the second CIS35 and the third CIS36 is stored (step S9). This position shift amount is used to calculate the average position shift amount (details will be described later. Therefore, in this description, the description of steps S10 and S11 related to the average position shift amount will be omitted).

Then, the holding roller 32 corrects the paper P again based on the amount of the positional deviation of the paper P detected by the second CIS35 and the third CIS36 (hereinafter, this operation is referred to as a paper re-correction operation, see step S12). .). During this re-correction operation, the second CIS35 and the third CIS36 repeatedly detect the amount of misalignment of the paper P every moment, and the detected amount of misalignment is fed back to the correction operation of the holding roller 32 each time. Feedback control is performed. As a result, the amount of misalignment of the paper P can be corrected with high accuracy. The detection operation by the second CIS35 and the third CIS36 is performed until the rear end of the paper P passes through the second CIS35. Further, the re-correction operation is completed before the paper P reaches the downstream roller.

Then, as shown in FIGS. 8A and 8B, the paper P corrected for the positional deviation reaches the secondary transfer roller 18 downstream, and the image is transferred at the secondary transfer nip position. (Step S13). As described above, the transfer device 30 performs the transfer operation of the paper P and the position shift correction operation during the transfer operation. In this way, the paper P reaches the secondary transfer position with the positional deviation corrected, and the image is transferred. Further, the holding roller 32 that has finished transporting the paper P returns to the reference position (see FIG. 2a) that is a position facing the transport path again in order to prepare for the next transport of the paper.

11 (a) and 11 (b) are views showing the locus of movement of the pinching roller 32 during the transporting operation by the above transporting device 30, and the vertical axis of FIG. 11 (a) is the width direction of the pinching roller 32. The vertical axis of the figure (b) shows the reference value of the rotation angle in the transport surface, and 0 on the vertical axis of the figure (a) is a state arranged in the center of the transport path 6, (b). 0 on the vertical axis of the above indicates a state facing the transport path 6. The value [μm] on the vertical axis in FIG. 9 shows the value of L1-L2 (difference in the detection position in the width direction by each CIS) when the distance M in FIG. 9 is 200 mm. The larger this value, the larger the amount of rotation of the sandwiching roller 32. Further, the horizontal axis indicates the position of the paper P in the transport direction, the point T1 is the position immediately before the pick-up operation (position in FIG. 3), the point T2 is the position immediately before the return operation (position in FIG. 5), and the point T3 is. The position after the return operation is completed (position in FIG. 6), the point T4 is the position immediately before the detection of the position shift again (the position in front of FIG. 7), and the point T5 is the position during the re-correction operation or after the completion (FIG. 8). The position in front of) is shown respectively. The thick line portion shown in the upper right of the figure shows the amount of misalignment of the paper detected by the second CIS35 and the third CIS36.

In the examples of FIGS. 11A and 11B, the amount of positional deviation in the width direction detected by the first CIS34 and the second CIS35 was about −500 μm, and the amount of skew was about 20 μm. Therefore, the sandwiching roller 32 picks up from the point T1 to the point T2 and moves by the amount of the above-mentioned positional deviation. Then, by performing the return operation from the point T2 to the point T3, the holding roller 32 returns to the reference position, and the positional deviation of the paper P is corrected.

At the position of the point T3 after the return operation, the amount of positional deviation detected by the first CIS34 and the second CIS35 is corrected. However, as shown by the thick line at the point T4, when the position deviation amount of the paper P is detected by the second CIS35 and the third CIS36, the position deviation amount in the width direction is detected by about 300 μm and the skew amount is detected by about 150 μm. .. After that, based on the amount of positional deviation detected by the second CIS35 and the third CIS36, the sandwiching roller 32 performs a re-correction operation between the points T4 and T5 to correct the positional deviation of the paper P.

In this way, even when the first correction operation (picking operation and returning operation), which is the first correction operation, is performed based on the detection results of the first CIS34 and the second CIS35, the second CIS35 and the third CIS36 A considerable amount of misalignment is detected at the time of detection. In this way, the factors that detect the positional deviation at the time of the second detection (hereinafter, also referred to as error factors) are the error of the mounting position of each CIS, the error of the correction amount by the holding roller 32, and the detection variation of the CIS. There is. In addition, as another factor, there is a positional deviation that occurs after detection by the first CIS34 and the second CIS35. Specifically, after the detection by the first CIS34 and the second CIS35, the position shift that occurs during the transfer by the transfer roller 31, the position shift due to the sandwiching roller 32 sandwiching the paper P, and the transfer and correction operation by the sandwiching roller 32. There are occasional misalignments, etc.

When the correction amount during the re-correction operation is large in this way, the re-correction operation cannot be completed by the time the paper P reaches the secondary transfer roller 18 (see FIG. 8) on the downstream side. There is a risk. Therefore, the correction amount at the time of the re-correction operation is reduced by the following configuration of the present embodiment.

First, among the above error factors, the mounting error of each CIS is an error that occurs by a fixed amount each time. Regarding other errors, it is considered that there are fixed components that occur in a substantially fixed amount each time and variable components that vary. For example, an error that occurs when the holding roller 32 holds, conveys, and corrects the paper P may tend to occur in a fixed direction each time due to an error in the shape of the parts of the holding roller 32 or the like. On the other hand, for example, since the amount of misalignment of the conveyed paper P varies, it is considered that the amount of error due to the above-mentioned operation of the holding roller 32 varies depending on the amount of misalignment of the paper P. As described above, there are a fixed component and a variable component as error factors.

Therefore, in the present embodiment, the above-mentioned average position deviation amount is used in order to reduce the correction amount at the time of re-correction. Specifically, the amount of misalignment of each sheet first detected by the second CIS35 and the third CIS36 is stored (step S9), and when N sheets of this data are accumulated (step S10), N sheets are stored. The average position shift amount is calculated as the average value of the position shift amount (step S11). That is, after the correction operation and before the re-correction operation, the position deviation amount detected by the second CIS35 and the third CIS36 is stored, and the average position deviation amount is calculated. By doing so, the amount of misalignment detected by the first CIS34 and the second CIS35 is corrected, and the amount of misalignment detected by the second CIS35 and the third CIS36 with respect to the paper P in the state before the re-correction is performed. Can be memorized. In other words, the detection error between the two CIS of the former and the two CIS of the latter can be stored. As N, a necessary value can be set as appropriate, and in this embodiment, it is set to 200 sheets.

The average position deviation amount calculated in this way is the sum of the above-mentioned fixed components and the average value of each variable component. Then, the calculated average position deviation amount is stored as a set value (step S11).

The average position deviation amount calculated as described above is used in the first correction operation. Specifically, it is determined whether or not there is a set average position shift amount before the pick-up operation (step S3). Then, when the average position shift amount is set, this average position shift amount is added to the position shift amount of the paper P detected by the first CIS34 and the second CIS35 in step S2 (step S4). The pick-up operation (step S5) and the return operation (step S7) are performed.

In this way, by adding the average value of the misalignment amount of the paper P first detected by the second CIS35 and the third CIS36 to the first correction amount, the correction amount at the time of re-correction, in other words, pinching. The amount of movement of the roller 32 can be reduced. That is, by adding the average position deviation amount to the first correction amount, the paper P is moved by the average value of the above fixed component and the variable component among the above error factors before the re-correction operation is started. Can be made to. As a result, the fixed component of the error factor can be removed in advance, and the variable component can be moved in advance by the average value, so that the correction amount at the time of re-correction can be reduced. Therefore, since the time required for the re-correction operation can be shortened, it is possible to prevent the re-correction operation from being completed during the paper P transfer by the holding roller 32. Therefore, the distance between the holding roller 32 and the downstream secondary transfer roller 18 can be reduced, and the device can be miniaturized.

If there is an error between the amount of positional deviation detected by the first CIS34 and the second CIS35 and the amount of positional deviation detected by the second CIS35 and the third CIS36, any of the detection results is regarded as positive on the paper P. In the present embodiment, the detection results of the second CIS35 and the third CIS36 on the downstream side are positive. This makes it possible to average and correct the amount of the positional deviation even after the first correction.

12 (a) and 12 (b) show an example of the movement locus of the pinching roller 32 when the above average position deviation amount is added and the first correction operation is performed. In the case of the present embodiment in which the solid line portion in the figure is corrected by adding the average position shift amount, the dotted line portion in the figure is the case where the same average position shift amount as in FIG. 11 is not used. The set average position shift amount is 200 μm for the position shift amount in the width direction and 100 μm for the skew amount, and the pick-up operation and the return operation are performed extra by this amount.

As shown in FIG. 12A, the amount of positional deviation in the width direction was detected by the first CIS34 and the second CIS35 at the point T1 by about −500 μm. Since the stored average position shift amount is 200 μm, the movement amount during the pick-up operation is −300 μm, and the movement amount during the return operation is 300 μm. That is, the correction amount of the paper P at the time of the first correction is 200 μm smaller than that of the dotted line portion in the figure.

Then, when the point T4 is reached, the misalignment amount of the paper is detected again by the second CIS35 and the third CIS36. When the average position shift amount is not used, a position shift amount in the width direction of about 300 μm is detected (position of the dotted line portion T4 in FIG. 12a). On the other hand, in the present embodiment, the amount of positional deviation detected at the point T4 is reduced by 200 μm to about 100 μm. As a result, the amount of movement during the re-correction operation is reduced, and the re-correction operation can be completed at an earlier stage.

Further, as shown in FIG. 12B, the amount of skew detected by the first CIS34 and the second CIS35 is about 20 μm, and the stored average position deviation amount is 100 μm, so that the amount of movement during the pick-up operation is Is 120 μm, and the amount of movement during the return operation is −120 μm. That is, the correction amount of the paper P at the time of the first correction is larger by 100 μm in the negative direction as compared with the dotted line portion in the figure. Therefore, at the point T4, the amount of skew detected at the dotted line portion by about 150 μm is reduced to about 50 μm. As a result, the amount of movement during the re-correction operation is reduced, and the re-correction operation can be completed at an earlier stage.

In this way, by adding and correcting the average position shift amount during the first correction operation, a part of the position shift amount detected by the second CIS35 and the third CIS36 can be corrected in advance. Therefore, it is possible to reduce the correction amount at the time of re-correction and complete the re-correction operation at an early stage in both the positional deviation in the width direction and the skew.

In particular, among the error factors that occur between the time of detection by the first CIS34 and the second CIS35 and the time of detection by the second CIS35 and the third CIS36, the mounting error of each CIS is an error that occurs quantitatively each time. Therefore, according to the configuration of the present embodiment, the correction amount at the time of re-correction caused by the mounting error of each CIS can be surely eliminated.

As described above, the number N of the sheets P for accumulating the data for calculating the average position deviation amount is set to 200 sheets from the time of the output operation in the present embodiment. In addition, the average position shift amount is replaced with the latest average value of 200 sheets every 200 sheets, and when the average position shift amount is replaced with a new average value, the count of step S10 is reset and 200 sheets are displayed again. I try to count. For example, the 1st to 200th sheets do not have the data of the average position deviation amount, and are the period for accumulating the data. When the data of the 200th sheet is stored, the average position deviation amount is calculated and the value is obtained. Is set as the set value (step S11). The 201st to 400th sheets are periods in which the first correction operation is performed using the average position deviation amount calculated from the data of the 1st to 200th sheets. At this time, a new count is started again from the 201st sheet, a new average position deviation amount is calculated for the 400th sheet, and the value is set as a new set value. Further, the period from the 401st sheet to the 600th sheet is a period in which the average position deviation amount calculated from the data of the 201st sheet to the 400th sheet is used. In this way, it is possible to replace every 200 sheets with a new average position shift amount.

At this time, it is necessary to add the already set average position deviation amount to the average position deviation amount calculated after the 201st sheet. For example, assuming that the average position deviation amount in the width direction calculated for the 1st to 200th sheets is 60 μm, and the average position deviation amount in the width direction calculated for the 201st to 400th sheets is 20 μm. The amount of positional deviation detected in the 201st to 400th sheets is the amount of positional deviation that has already occurred after adding 60 μm during the first correction operation. Therefore, the average positional deviation amount of the 201st to 400th sheets is It is necessary to add 60 μm to make it 80 μm.

Further, regarding the above setting values of the average position deviation amount, the average position deviation amount is initialized when the operation in which the error factor fluctuates occurs, and the data is input from the first sheet of the paper P which has been conveyed thereafter. You can also take it. For example, it is assumed that a jam of the paper P occurs in the transport device 30 and the guide plate provided in the transport device 30 is opened and closed to eliminate the jam of the paper P. In this case, it is considered that the mounting position of each CIS changes slightly due to the opening and closing of the guide plate, and the error of the mounting position of each CIS fluctuates. Therefore, the average position deviation amount can be calculated when the 200th sheet is printed, with the first printed sheet after the jam processing as the first sheet, and can be used for the correction of the 201st and subsequent sheets.

In addition, as the operation in which the error factor fluctuates, each member constituting the holding roller 32, particularly the replacement operation of the drive motor for operating each operation of the holding roller 32, the replacement of the holding roller 32 itself, the attachment / detachment operation, and the operation of attaching / detaching the holding roller 32 are also performed. Each member provided in the transport device 30 or the transport device 30 itself may be attached to or detached from the image forming device for reasons such as parts replacement. With such an operation as a starting point, the average position shift amount can be initialized, and new data can be obtained from the paper conveyed thereafter.

Further, in the case where the image forming apparatus is provided with a plurality of paper feed units, the value of the above error factor fluctuates because the paper transfer path changes depending on which paper feed unit the paper is conveyed from. do. Further, when the size of the paper differs depending on the paper feed unit, the error factor also changes depending on the size of the paper. Therefore, it is possible to store the data of the average position shift amount for each paper feed unit and perform the correction operation by using the average position shift amount corresponding to each paper feed unit. Alternatively, when the paper feed unit that supplies the paper P is changed, the average position shift amount that has been set up to that point is initialized, and the position shift amount is newly stored and averaged from the paper to be printed next. It is also possible to calculate the amount of misalignment. Further, even when the same paper feed unit is used, the average position deviation amount can be initialized when the used paper feed unit is opened and closed. That is, once the paper feed unit is opened and closed, it is conceivable that a new bundle of paper is set in the paper feed unit and the posture of the paper loaded in the paper feed unit is changed. In such a case, it is considered that the tendency of the misalignment of the conveyed paper changes and the error factor changes.

As described above, it is possible to initialize the average position deviation amount that has been set up to that point from the operation in which the error factor fluctuates, and then to newly calculate the average position deviation amount. By doing so, it is possible to more accurately capture the change in the detection error that occurs between the time of detection by the first CIS34 and the second CIS35 and the time of detection by the second CIS35 and the third CIS36. That is, the holding roller 32 can be made to perform the first correction operation by using the data of the appropriate average position deviation amount, and the correction amount at the time of the re-correction operation can be reduced more effectively.

FIG. 13 is a block diagram showing a configuration of a control unit that controls each operation of the above transport device 30.
As shown in FIG. 13, the control unit 60 includes a first motor control unit 61, a second motor control unit 62, a correction amount calculation unit 63, and a position shift amount storage unit 64.

The first motor control unit 61 and the second motor control unit 62 are parts that control each movement operation of the sandwiching roller 32 based on the correction amount information sent from the correction amount calculation unit 63.

The first motor control unit 61 is a part that controls the rotational operation of the holding roller 32 in the transport surface. In response to the signal from the first motor control unit 61, the first motor driver 611 drives the first motor 612 to rotate the holding roller 32 in the transport surface. Then, the rotation amount of the sandwiching roller 32 in the transport surface is detected by the first motor encoder 613.

The second motor control unit 62 is a portion that controls the movement operation of the sandwiching roller 32 in the width direction. In response to the signal from the second motor control unit 62, the second motor driver 621 drives the second motor 622 to move the sandwiching roller 32 in the width direction. Then, the second motor encoder 623 detects the amount of movement of the sandwiching roller 32 in the width direction.

These first motor 612 and second motor 622 pick up the holding roller 32 (step S5 in FIG. 10), return operation (step S7), re-correction operation (step S12), and return to the reference position. Will be driven at the time.

The correction amount calculation unit 63 calculates the skew amount of the paper P and the position deviation amount in the width direction from the detection information received from each CIS. Then, the correction amount calculation unit 63 sends the information of this positional deviation amount to the first motor control unit 61 and the second motor control unit 62.

Further, when the correction amount calculation unit 63 calculates the position deviation amount of each paper P from the position information first detected by the second CIS35 and the third CIS36, the position deviation amount is stored in the position deviation amount storage unit 64. It will be remembered. Then, when the stored position shift amount reaches the reference number (200 sheets in this embodiment), the average position shift amount is calculated. Further, the position shift amount storage unit 64 inputs the average position shift amount, which is the current set value, to the correction amount calculation unit 63. The correction amount calculation unit 63 adds the input average position deviation amount to the movement amount during the pick-up operation and the return operation.

The first motor control unit 61 and the second motor control unit 62 drive each motor according to the correction amount (movement amount) input from the correction amount calculation unit 63, and rotate the holding roller 32 in the transport surface in the width direction. Move to.

As described above, the control unit 60 can move the holding roller 32 based on the detection information of each CIS to correct the misalignment of the paper P.

Next, the configuration of the sandwiching roller 32 that performs each of the above-mentioned operations will be described in more detail with reference to FIGS. 14 to 17. Specific operations performed by the sandwiching roller 32 include a rotation operation for conveying the paper, a rotation operation in the conveying surface for correcting the positional deviation, and a movement operation in the width direction.

The sandwiching roller 32 can perform a rotational operation in the transport surface and a movement operation in the width direction by the roller moving mechanism. As shown in FIG. 14, this roller moving mechanism has a base frame 152 fixed on the main body frame 151. The base frame 152 has two upper and lower horizontal plates 153 and 154, and a roller holding member 110 for supporting the sandwiching roller 32 is movably arranged on the upper horizontal plate 154 in the horizontal direction.

As shown in FIG. 15, four free bearings 111 (ball transfer) are arranged at positions corresponding to the four corners of the bottom surface of the roller holding member 110 on the upper surface of the upper horizontal plate 154. A roller holding member 110 is arranged on the free bearing 111 so as to be movable back and forth and left and right in the horizontal direction. The arrow in FIG. 15 indicates the paper transport direction.

As is known, the free bearing 111 has a steel ball rotatably fitted in a recess of a pedestal, and the top of the steel ball is in point contact with the bottom surface of the roller holding member 110. The minimum number of free bearings 111 is three, but in the illustrated example, four are arranged to ensure stable movement of the roller holding member 110.

As shown in FIG. 14, the roller holding member 110 is composed of a plate-shaped frame extending in a direction orthogonal to the transport direction of the paper P. Both ends of the plate-shaped frame are bent upward at a right angle, and bearings 114 and 115 are fixed side by side in the bent portion. On one side of the lower surface of the roller holding member 110, a rotation receiving portion 110b extending by a predetermined length in a direction orthogonal to the transport direction of the paper P is integrally formed vertically with the lower surface of the roller holding member 110.

The sandwiching roller 32 is composed of a drive roller 32b on the lower stage side and a driven roller 32a on the upper stage side. The rotating shaft of the driven roller 32a on the upper stage side is supported by the bearing 114 on the upper side of the roller holding member 110, and the rotating shaft of the drive roller 32b on the lower stage side is supported by the bearing 115 on the lower side of the roller holding member 110.

The rotary encoder 144 is mounted on the rotating shaft of the drive roller 32b protruding outward from the lower bearing 115. Then, based on the rotation speed of the drive roller 32b detected by the rotary encoder 144, the rotation speed variable roller drive motor 140 described later is driven, and the driven roller 32a rotates in accordance with the rotation of the drive roller 32b. It has become.

A support shaft 110a as a guided portion that projects downward shortly is fixed to the lower surface of one side of the roller holding member 110. A guide roller 136 is rotatably mounted on the lower end of the support shaft 110a, and a cam follower 135 is rotatably mounted on the intermediate portion of the support shaft 110a.

The first motor 120, the second motor 130, and the rotary encoders 128 and 138 are arranged side by side in the left-right direction on the lower horizontal plate 153. On the other hand, the first motor 120 is for skewing compensation, and the drive pulley 121 is fixed to the rotating shaft thereof. The other second motor 130 is for correcting the positional deviation in the width direction, and another drive pulley 131 is fixed to the rotating shaft thereof.

Instead of one of the rotary encoders 128, an arbitrary encoder (for example, a linear encoder) or an arbitrary sensor (for example, a laser displacement meter) for detecting the movement and position of the first rotation cam 124 or the lever member 125, which will be described later, is provided. You may. Further, instead of the other rotary encoder 138, an arbitrary encoder (for example, a linear encoder) or an arbitrary sensor (for example, a laser displacement meter) for detecting the movement and position of the shift cam 134 and the roller holding member 110 described later may be provided.

The driven pulleys 122 and 132 are rotatably supported between the upper and lower horizontal plates 153 and 154. The upper and lower ends of the rotary shafts 122a and 132a of the driven pulleys 122 and 132 are rotatably supported by the upper and lower horizontal plates 153 and 154, respectively. The axes of rotation 122a and 132a are parallel to each other. The timing belts 123 and 133 are bridged between the drive pulleys 121 and 131 and the driven pulleys 122 and 132, respectively.

The rotary plates 128a and 138a, which are the rotary side parts of the rotary encoders 128 and 138, are fixed to the rotary shafts 122a and 132a of the driven pulleys 122 and 132 protruding downward from the lower horizontal plate 153. A plurality of slits are continuously formed in the peripheral edge portion of the rotating plates 128a and 138a, and a light emitting / receiving device which is a fixed side component of the rotary encoder 128a and 138 is arranged so as to sandwich the peripheral edge portion vertically.

The first rotating cam 124 and the shift cam 134 are fixed to the upper ends of the rotating shafts 122a and 132a of the driven pulleys 122 and 132 protruding upward from the upper horizontal plate 154. The cam curves of the first rotating cam 124 and the shift cam 134 are formed so as to be constant velocity cam curves, respectively. By using the constant velocity cam, the rotation angle of the first rotation cam 124 and the shift cam 134 and the linear movement distance of the cam followers 126 and 135 described later become proportional to each other, and the shift position control of the support shaft 110a and the lever member 125 are made. Rotation control becomes easy.

An elongated hole 154a as a guide portion extending in a direction orthogonal to the paper transport direction is formed in the upper horizontal plate 154 located adjacent to the shift cam 134 on one side. A guide roller 136 at the lower end of the support shaft 110a is inserted into the elongated hole 154a. As shown in FIG. 15, the cam follower 135 at the intermediate portion of the support shaft 110a is in contact with the cam surface at the peripheral edge portion of the shift cam 134 by the force of the tension spring 113. The elongated hole 154a is for guiding the guide roller 136 in a straight line, and it is also possible to use an elongated groove instead of the elongated hole.

A fulcrum shaft 154b is projected on the upper horizontal plate 154 on the opposite side of the shift cam 134, and a lever member 125 is rotatably arranged on the fulcrum shaft 154b in the horizontal direction. The cam follower 126 and the acting roller 127 as the first pressing portion are rotatably mounted on the support shafts 125a and 125b integrally formed on both ends of the lever member 125 via an arbitrary bearing material such as a ball bearing. There is. The outer peripheral surface of the cam follower 126 is in contact with the outer peripheral surface of the first rotating cam 124 by the spring force of the first tension spring 112. The outer peripheral surface of the working roller 127 is in contact with the rotation receiving portion 110b by the spring force of the first tension spring 112.

That is, as shown in FIG. 14, the first pressing is performed by the first motor 120 for skew correction, the drive pulley 121, the timing belt 123, the driven pulley 122, the first rotating cam 124 and the lever member 125, and the acting roller 127. Acting as a unit A first driving unit that moves the roller 127 back and forth in the direction of the transport path of the paper P is configured.

Further, the second motor 130 for correcting the positional deviation in the width direction, the drive pulley 131, the timing belt 133, the driven pulley 132, and the shift cam 134 abut against the support shaft 110a as the guided portion via the cam follower 135. A second drive unit having a pressing portion (cam outer peripheral surface) and moving the support shaft 110a left and right in a direction orthogonal to the transport path of the paper P is configured.

The bracket 155 is vertically arranged on one end side of the holding roller 32 in the axial direction on the main body frame 151. A variable rotation speed roller drive motor 140 for rotationally driving the drive roller 32b of the holding roller 32 is fixed to the outer surface of the bracket 155. The rotation shaft of the roller drive motor 140 projects horizontally toward the inside of the bracket 155, and the pinion 141 is fixed to the rotation shaft protruding inward. The pinion 141 is meshed with a reduction gear 142 pivotally supported inside the bracket 155.

The rotary shaft 142a of the reduction gear 142 is connected to the rotary shaft 32b1 of the drive roller 32b of the sandwiching roller 32 via the two-stage spline coupling 143. As a result, the rotational driving force of the roller drive motor 140 is transmitted to the drive roller 32b via the pinion 141, the reduction gear 142, and the two-stage spline coupling 143, and the holding roller 32 is rotationally driven. Therefore, the paper P can be conveyed at an arbitrary transfer speed by rotating the drive roller 32b with the roller drive motor 140 while the sandwiching roller 32 sandwiches the paper P.

The two-stage spline coupling 143 is a kind of constant velocity universal joint, and as shown in the partially enlarged view of FIG. 14, the first spline gear 143a, the second spline gear 143b, the intermediate spline gear 143c, the guide ring 143d, etc. It is configured.

The first spline gear 143a is an external gear and is installed on a rotating shaft 142a that rotates together with the reduction gear 142 of the first drive unit. The rotary shaft 142a is rotatably held by the bracket 155 via a bearing.

The second spline gear 143b is also an external gear and is connected to the rotating shaft 32b1 of the drive roller 32b of the holding roller 32. The intermediate spline gear 143c is an internal gear, and is extended in the width direction so as to always mesh with the two spline gears 143a and 143b even if the sandwiching roller 32 (roller holding member 110) moves in the width direction. Further, the two spline gears 143a and 143b are formed in a crown shape so as to mesh with the intermediate spline gear 143c even if the sandwiching roller 32 (roller holding member 110) rotates in an oblique direction.

By using such a two-stage spline coupling 143, the sandwiching roller 32 is satisfactorily rotationally driven. That is, even if the pinching roller 32 rotates around the support shaft 110a in the substantially horizontal plane direction or slides in the width direction, the driving force of the roller drive motor 140 on the fixed side drives the pinching roller 32. It is accurately and surely transmitted to the roller 32b.

The guide ring 143d is a substantially annular stopper member installed at both ends of the intermediate spline gear 143c in the width direction, and the two spline gears 143a and 143b move relatively in the width direction to form a two-stage spline cup. Prevents it from falling off the ring 143.

16 (a) to 16 (d) are diagrams showing the operation of the sandwiching roller 32 at the time of correcting the positional deviation, and FIGS. 16 (b) and 16 (c) show the skew correction of the paper P and the position in the width direction. In order to show the operation of the deviation correction in an easy-to-understand manner, the operation of the skew correction and the operation of the horizontal register correction are shown separately. Actually, as shown in FIG. 16D, the skew correction operation and the position deviation correction operation in the width direction are performed in combination.

16 (a) → (b) shows the horizontal register correction operation of the paper P. That is, when the second motor 130 is driven and the shift cam 134 is rotated, the roller holding member 110 slides to the right side so as to resist the spring force of the second tension spring 113 by the shift cam 134. At this time, since the cam follower 135 moves on the outer periphery of the shift cam 134 while rotating, the moving load of the roller holding member 110 acting on the second motor 130 for correcting the positional deviation in the width direction can be small.

Further, since the action roller 127 of the lever member 125 rolls on the surface of the rotation receiving portion 110b while receiving the force of the first tension spring 112, the roller holding member 110 slides smoothly. In other words, since the acting roller 127 is not subjected to the frictional load due to the lateral shift movement of the roller holding member 110, the roller holding member 110 can be smoothly rotated and shifted. In the state where the first rotation cam 124 is stopped, the rotation receiving portion 110b is also stopped in the paper transport direction, so that the skew correction operation of the paper P does not occur.

16 (a) → (c) show the skew correction operation of the paper P. That is, when the first motor 120 is driven and the first rotation cam 124 is rotated, the lever member 125 is pushed by the first rotation cam 124 and rotates counterclockwise around the fulcrum shaft 154b. ..

As a result, the roller holding member 110 is pushed by the action roller 127 of the lever member 125 at the position of the rotation receiving portion 110b, and the roller holding member 110 is a support shaft at the right end so as to resist the spring force of the first tension spring 112. It rotates counterclockwise around 110a. At this time, since the cam followers 126 and 135 move around the outer circumferences of the first rotating cam 124 and the shift cam 134 while rotating, the rotational load of the roller holding member 110 acting on the first motor 120 for skew correction is small. It's done.

16 (a) → (d) show a combination of the position shift correction operation and the skew correction operation in the width direction of the paper P. That is, when the first motor 120 is driven to rotate the first rotation cam 124 and the second motor 130 is driven to rotate the shift cam 134, the lateral registration correction operation of (b) described above (b) An operation in which the skew correction operation of c) is combined occurs.

As described above, in the present embodiment, the sandwiching roller 32 is held by the roller holding member 110 which can move in the width direction of the paper transport path and can rotate around the support shaft 110a, and the roller drive motor 140 on the fixed side is rotationally driven. The force is transmitted to the sandwiching roller 32 via the two-stage spline coupling 143. Therefore, the roller drive motor 140 and the second motor 130 for correcting the positional deviation in the width direction can be arranged on the fixed side, and the responsiveness of the skew correction can be improved by reducing the weight of the structure above the roller holding member 110. I can plan.

In the above-mentioned position deviation correction and skew correction in the width direction, as shown in FIG. 17, 1) the skew amount of the paper P is θ, 2) the position deviation correction amount in the width direction is Δy, and 3) the width direction of the paper. Let d be the distance between the reference position (the initial position of the support shaft 110a which is the guided portion) and the center of the support shaft 125b of the acting roller 127 as the first pressing portion of the first driving portion. In FIG. 17, Δy is brass on the right side and negative on the left side from the reference position in the width direction of the paper. Further, the arrow in FIG. 17 indicates the paper transport direction.

In this case, assuming that the back-and-forth movement distance of the rotation receiving part 110b that moves back and forth by the working roller 127 is Δx, skewing as the first driving part by the control unit based on the result calculated by the following mathematical formula (1). The first motor 120 for correction is controlled.
Δx = (d + Δy) tanθ ... (2)

The reason for multiplying tan θ by (d + Δy) instead of simply multiplying it by d when calculating Δx in the equation (2) is as follows. That is, as described above, it is rare that only the position shift correction operation in the width direction of FIG. 16 (b) or the skew correction operation of FIG. 16 (c) occurs, and usually as shown in FIG. 16 (d). The shape is a combination of the skew correction operation and the position deviation correction operation in the width direction.

Therefore, if the roller holding member 110 is rotated (pick-up operation) by Δx calculated by the mathematical formula (3) described later, ignoring Δy, the pick-up operation becomes too large or too small. That is, an skew correction error occurs due to the position shift correction in the width direction.

For example, as shown in FIG. 17, when the support shaft 110a moves to the right by Δy to correct the positional deviation in the width direction, the rotation receiving portion is driven by driving the first motor 120 for skew correction without considering this movement. If 110b is moved by Δx, the amount of skew cannot be corrected. That is, since the control unit calculates Δx by the following mathematical formula (2), as a result of the pick-up operation amount being too small, the skew amount cannot be corrected by the equal amount of return operation amount at the time of recovery.
Δx = d · tan θ… (3)

On the contrary, considering the case where the support shaft 110a moves to the opposite side (that is, the left side) by Δy for lateral registration correction in FIG. 17, the first motor 120 for skew correction is driven without considering this movement. If the rotation receiving portion 110b is moved by Δx, the skew amount is corrected too much this time. That is, as a result of the pick-up operation amount being too large, the return operation amount of the same amount at the time of recovery is too large and the skew amount is corrected too much.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

In the embodiment described above, the transport device 30 is provided with three CIS, the first CIS34 and the second CIS35 are used as the detection mechanism (upstream detection mechanism) for the first correction, and the second CIS35 and the third CIS36 are used. Was used as a detection mechanism (downstream side detection mechanism) for re-correction operation. However, for example, when only the positional deviation in the width direction of the paper is corrected, the detection operation can be performed even with one CIS, so that the transport device 30 may be provided with only two CIS. In this case, the average position shift amount can be calculated by storing the position shift amount in the width direction first detected by the CIS on the downstream side. Further, as for the detection mechanism, a known detection mechanism can be appropriately adopted as long as it can detect the misalignment of the paper.

The image forming apparatus according to the present invention is not limited to the color image forming apparatus shown in FIG. 1, and may be a monochrome image forming apparatus, a copying machine, a printer, a facsimile, or a combination machine thereof.

Further, in the embodiment described above, the present invention has been applied to the transport device 30 installed in the electrophotographic image forming apparatus 1, but to the transport device installed in the inkjet type image forming apparatus. The present invention can also be applied. Hereinafter, an inkjet type image forming apparatus will be described with reference to FIG.

As shown in FIG. 18, the inkjet type image forming apparatus 200 includes a feeding unit 210, a conveying device 220, an image forming unit 230, a drying unit 240, and a paper ejection unit 250.

The paper P sent out from the paper feeding unit 210 is conveyed by the conveying device 220 and sent out to the image forming unit 230.

In the image forming unit 230, the paper P is positioned on the cylindrical drum 231 and is conveyed in the direction of the arrow in the figure by the rotation of the cylindrical drum 231. Then, the paper P is conveyed to the lower part of the ejection head 232 of each color (the position where the image is formed on the paper P) at a predetermined timing, the ink of each color is discharged to the paper P, and the image is formed on the surface of the paper P. ..

The paper P on which the image is formed by the image forming unit 230 is conveyed to the drying unit 240 to evaporate the moisture in the ink, and then is discharged to a position where the operator can take it out by the paper ejection unit 250.

When double-sided printing is performed, after the drying step, the paper P is sent to the reverse transfer path 260, and the paper P is sent to the transfer device 220 again with the front and back sides inverted.

By applying the configuration of the transport device of the present invention described above to the transport device 220, the same effect as that of the present embodiment described above can be obtained. That is, the transport device 220 corrects the skew of the paper P and the positional deviation in the width direction. Then, the paper P is conveyed to the downstream image forming unit 230 in a state where the positional deviation of the paper P is corrected.

Sheets include paper P (plain paper), thick paper, postcards, envelopes, thin paper, coated paper (coated paper, art paper, etc.), tracing paper, transparencies, plastic films, prepregs, copper foil, etc. Is done.

1 Image forming device 18 Secondary transfer roller 30 Transfer device 31 Transfer roller 32 Holding roller (correction member)
34 First CIS (upstream detection mechanism)
35 Second CIS (Detection Mechanism)
36 Third CIS (downstream detection mechanism)
60 Control unit P paper (sheet)

Japanese Unexamined Patent Publication No. 2016-88702 Japanese Unexamined Patent Publication No. 2016-108152 Japanese Unexamined Patent Publication No. 2016-175776

Claims (10)

A correction member that corrects the misalignment of the seat, and
An upstream detection mechanism that detects the misalignment of the seat,
A downstream detection mechanism provided on the downstream side of the upstream detection mechanism in the seat transport direction to detect a positional deviation of the seat, and a downstream detection mechanism.
A transport device having a control unit for controlling the correction operation of the correction member.
The control unit stores the average position shift amount obtained by averaging the position shift amount of the sheet detected by the downstream detection mechanism for a plurality of the sheets.
The control unit performs a correction operation on the correction member to correct the position deviation of the seat based on at least the detection result of the upstream side detection mechanism and the average position deviation amount, and at least the downstream side detection mechanism. Based on the detection result of, the re-correction operation for correcting the misalignment of the sheet is performed again .
By moving or attaching / detaching at least one of the upstream side detection mechanism and the downstream side detection mechanism, the set average position shift amount is initialized, and the position shift amount is newly stored from the subsequent sheet transfer. A transport device characterized by calculating an average position shift amount . A correction member that corrects the misalignment of the seat, and
An upstream detection mechanism that detects the misalignment of the seat,
A downstream detection mechanism provided on the downstream side of the upstream detection mechanism in the seat transport direction to detect a positional deviation of the seat, and a downstream detection mechanism.
A transport device having a control unit for controlling the correction operation of the correction member.
The control unit stores the average position shift amount obtained by averaging the position shift amount of the sheet detected by the downstream detection mechanism for a plurality of the sheets.
The control unit performs a correction operation on the correction member to correct the position deviation of the seat based on at least the detection result of the upstream side detection mechanism and the average position deviation amount, and at least the downstream side detection mechanism. Based on the detection result of, the re-correction operation for correcting the misalignment of the sheet is performed again .
The transport is characterized in that the set average position shift amount is initialized by moving or attaching / detaching the correction member, the position shift amount is newly stored from the subsequent sheet transfer, and the average position shift amount is calculated. Device. The transfer device according to claim 1 or 2 , wherein the position shift amount used by the control unit to calculate the average position shift amount is the position shift amount first detected by the downstream detection mechanism for the sheet. The position deviation amount used by the control unit to calculate the average position deviation amount is the position deviation amount of the sheet detected by the downstream side detection mechanism before the start of the re-correction operation according to claim 1 or 2 The transport device according to any one of them. The transport device according to any one of claims 1 to 4 , wherein when the average position deviation amount is not set, the correction operation is performed based on the detection result of the upstream side detection mechanism. Further having a detection mechanism provided between the upstream side detection mechanism and the downstream side detection mechanism, the control unit is the correction member based on the detection result by the upstream side detection mechanism and the detection mechanism. To perform the correction operation, and the control unit causes the correction member to perform the re-correction operation based on the detection results of the detection mechanism and the downstream side detection mechanism, and the average position deviation amount. The transport device according to any one of claims 1 to 5 . The set average position deviation amount is initialized by moving or attaching / detaching the detection mechanism provided between the upstream side detection mechanism and the downstream side detection mechanism, and a new position deviation amount is newly obtained from the subsequent sheet transfer. 6. The transport device according to claim 6, which stores the above and calculates the average position deviation amount. An image forming apparatus including the transport device according to any one of claims 1 to 7. The image forming apparatus according to claim 8, further comprising a plurality of paper feeding units for transporting the sheet to the transport device.
The control unit initializes the average position deviation amount each time the paper feeding unit that supplies the sheet is changed, newly stores the position deviation amount from the subsequent sheet transfer, and calculates the average position deviation amount. Image forming device to calculate. The image forming apparatus according to claim 8, further comprising a plurality of paper feeding units for transporting the sheet to the transport device.
The control unit is an image forming apparatus that stores the average position deviation amount for each paper feeding unit that supplies the sheet.

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