JP2007168974A - Sheet carrying device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet carrying device capable of properly adjusting a position in the width direction of a sheet by accurately positioning a guide plate in a home position. <P>SOLUTION: A sensor 401 detects the guide plate in a detecting section including the home position of the guide plate 139. A data acquiring part 604 acquires the pulse number of a motor when moving the guide plate to the detecting section. A storage part 606 stores data on the pulse number measured in the past. A determining part 605 determines whether or not normal data is acquired on the basis of a statistical value provided from the stored data and a value of the acquired data. A guide plate movement control part 603 positions the guide plate in the home position by using the normally acquired data, and moves the guide plate from the home position in response to a width of the sheet. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sheet conveying apparatus and an image forming apparatus including the sheet conveying apparatus, and more particularly to a sheet conveying apparatus and an image forming apparatus that adjust a position in the width direction of a sheet during conveyance.

  Some image forming apparatuses such as printers, copiers, and multi-function machines adjust the position in the width direction of a sheet during sheet conveyance in order to align the position of a sheet such as paper and the image formed on the sheet. is there. For example, in an image forming apparatus that performs double-sided printing by the switchback method, when the sheet is switched back and conveyed, the position in the width direction of the sheet can be adjusted and the direction of the sheet can be aligned in the conveyance direction.

For this adjustment, a guide plate that can be reciprocated in the width direction of the sheet can be used. In the sheet conveying apparatus as described in Patent Document 1 or Patent Document 2, the guide plate is moved according to the width of the sheet, and the width of the conveying path is adjusted to the width of the sheet. The position in the width direction of the sheet is adjusted by regulating the side edge of the sheet with the guide plate. The amount of movement of the guide plate can be determined from a value of a predetermined size if it is a sheet of a specified size. If the sheet is not a specified size, for example, the size in the width direction of the sheet may be detected.
Japanese Patent Laid-Open No. 7-330228 JP-A-11-43265

  However, even if the amount of movement of the guide plate is appropriately determined as described above, there is a possibility that the position of the guide plate after the movement is displaced, thereby shifting the position in the width direction of the sheet. For example, the amount of movement of the guide plate is determined according to the width of the sheet as the distance from the home position where the width of the conveyance path is maximized. When the driving amount of the motor is determined in order to align the guide plate with the home position, an error may occur due to the sensitivity of the sensor or the slipping of the gear. If there is an error in the driving amount such as the number of pulses of the stepping motor, even if the movement amount is determined according to the width of the sheet, the error appears as a deviation of the sheet position.

  The present invention has been made in view of such problems in the conventional technology, and by appropriately aligning the guide plate to a reference position such as the home position, the position and orientation in the width direction of the sheet are appropriately adjusted. It is an object of the present invention to provide a sheet conveying apparatus that can be adjusted and an image forming apparatus including the sheet conveying apparatus.

  In order to solve the above problems, the present invention employs the following configuration. The sheet conveying apparatus provided by the present invention includes a guide plate provided so as to be capable of reciprocating in the sheet width direction, and a motor for driving the guide plate. In addition, a sensor that detects the guide plate in a section including the reference position of the guide plate and a data acquisition unit that acquires data of a drive signal to the motor when the detection section is moved to the guide plate. Further, a storage unit that stores drive signal data, a determination unit that determines whether normal data is acquired based on a statistical value obtained from the stored data and a value of acquired data, and a normal acquisition A guide plate movement control unit that aligns the guide plate with the reference position using the data and moves the guide plate from the reference position according to the width of the sheet.

  In this sheet conveying apparatus, data of a drive signal to the motor when the sensor detection section is moved to the guide plate is stored in a storage unit such as a memory. The data is data relating to the number of pulses to the stepping motor, for example. The sheet conveying apparatus determines whether normal data has been acquired based on the statistical value obtained from the data and the newly acquired data value. By aligning the guide plate with the reference position using the data acquired normally, it is guaranteed that the guide plate is accurately aligned with the reference position. The guide plate can always be appropriately adjusted.

  The sheet conveying apparatus may further include a retry unit that acquires data of the drive signal and repeats determination when normal data is not acquired. By providing the retry unit, even when normal data is not acquired due to a temporary malfunction, it is possible to perform accurate alignment without taking the user's trouble.

  Further, a defect notification unit may be provided in the sheet conveying apparatus. The defect notifying unit notifies a registration defect when normal data is not acquired even after repeated determinations. By this notification, it is possible to notify the user of the possibility of failure or the like.

  Further, in the sheet conveying apparatus, when normal data is acquired, the guide plate movement control unit corrects the value of the data based on an error between the value of the data and the statistical value, and uses the corrected data. The guide plate may be aligned with the reference position. As a result, it is possible to make the alignment of the guide plate to the reference position more suitable according to the time series tendency.

  In another aspect, the present invention provides a section including a pair of guide plates that are reciprocally movable in the width direction of the sheet, a stepping motor that drives the guide plates, and a reference position where the distance between the guide plates is maximum. A sensor for detecting the guide plate, a data acquisition unit for acquiring data on the number of pulses to the stepping motor while the sensor is detecting the guide plate, a storage unit for storing data on the number of pulses, and Based on the statistical value obtained from the data and the value of the acquired data, a determination unit that determines whether normal data has been acquired, and the guide plate is aligned with the reference position using the data acquired normally, Provided is a sheet conveying apparatus including a guide plate movement control unit that moves a guide plate from a reference position according to the width of the sheet.

  In this sheet conveying apparatus, for example, an optical sensor having a detection width in the sheet width direction can be used as the sensor.

  In still another aspect, the present invention provides an image forming apparatus including the sheet conveying device as described above. By providing the sheet conveying device, the image forming apparatus can appropriately align the position of the image and the sheet.

  By adopting the configuration as described above, in the present invention, it is possible to accurately align the guide plate to a reference position such as the home position and appropriately adjust the position and orientation in the width direction of the sheet. .

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. In this embodiment, the present invention is embodied as a printer having a double-sided printing function and a sheet conveying device built in the printer.

  FIG. 1 is a diagram for explaining a schematic configuration of a printer according to the present embodiment. The printer 101 includes an image forming unit 102, a paper feed cassette 103, and a paper transport device 104.

  A photosensitive drum 105 is disposed in the image forming unit 102. The photosensitive drum 105 rotates in the direction of arrow 106 at a constant speed. Around the photosensitive drum 105, a charger 107, a developing device 108, a transfer device 109, and a cleaning unit 110 are arranged in this order from the upstream side in the rotation direction. Further, a laser unit 111 is disposed on the upper part of the image forming unit 102.

  In the image forming unit 102, the charger 107 uniformly charges the surface of the photosensitive drum 105. The laser unit 111 irradiates the uniformly charged surface of the photosensitive drum 105 with light modulated in accordance with data input from an external device, thereby forming an electrostatic latent image on the photosensitive drum 105. The developing device 108 attaches toner to the electrostatic latent image and forms a toner image on the photosensitive drum 105. The transfer unit 109 transfers the toner image on the photosensitive drum 105 to a sheet, and the cleaning unit 110 cleans the surface of the photosensitive drum 105. These processes are performed in series by rotating the photosensitive drum 105.

  The paper feed cassette 103 is disposed below the image forming unit 102 and can store a plurality of sheets 112 supplied to the image forming unit 102. The stacked sheets 112 are fed one by one to the sheet conveying device 104 by the sheet feeding roller 113.

  The paper transport device 104 has a transport path 114 that transports the paper 112 from the paper feed cassette 103 to the image forming unit 102. A conveyance roller 115 and a registration roller 116 are provided in the conveyance path 114. The transport roller 115 transports the paper 112 from the paper feed cassette 103 to the registration roller 116. The registration roller 116 conveys the paper 112 to a transfer portion between the photoconductive drum 105 and the transfer device 109 in synchronization with the formation of the toner image on the photoconductive drum 105. The sheet on which the toner image is transferred by the transfer unit is conveyed to the fixing device 117. The fixing device 117 includes a heating roller 118 and a pressure roller 119, and fixes the toner image on the paper 112 by heat and pressing force. The sheet 112 on which the image is printed in this way is conveyed to the conveyance roller 121 through the conveyance path 120. The transport roller 121 transports the paper 112 to the paper discharge roller 123 through the transport path 122, and the paper discharge roller 123 discharges the paper 112 to the paper discharge tray 124 face down.

  In this embodiment, the sheet conveying apparatus 104 has a switchback type conveying path in the double-sided conveying unit 125 in addition to such a normal conveying path. The duplex conveyance unit 125 reverses the conveyance direction of the paper 112 on which an image is printed on one side so that the other surface of the paper 112 faces the image forming unit 102 and then conveys the paper to the image forming unit 102 again. Branches for connecting the double-sided conveyance unit 125 to the normal conveyance path are provided immediately downstream of the conveyance roller 121 and immediately upstream of the conveyance roller 115, respectively, and downstream of the conveyance path 120 via the double-sided conveyance unit 125. And the upstream side of the conveyance path 114 are connected. When performing duplex printing, a branching claw 126 disposed at a branch downstream of the conveyance roller 121 closes the conveyance path 122 and guides the paper 112 that has passed through the fixing device 117 to the conveyance path 127 of the double-side conveyance unit 125. The sheet 112 guided to the conveyance path 127 is returned to the conveyance path 114 through the reverse conveyance path 128 and the conveyance path 129. Guidance from the conveyance path 129 to the conveyance path 114 is performed by a branching claw 130 disposed at a branch upstream of the conveyance roller 115. The sheet 112 that has once passed through the fixing device 117 is returned to the image forming unit 102 through such a bypass path. When images are printed on both sides of the paper 112, the paper transport device 104 guides the paper 112 to the transport path 122 by the branching claw 126 and discharges the paper 112 to the paper discharge tray 124.

  In the double-sided conveyance unit 125, a conveyance roller 131 is provided in the conveyance path 127. The sheet 112 guided to the double-sided conveyance unit 125 is conveyed along the conveyance path 127 by the conveyance roller 131. A conveyance roller 132 is disposed between the conveyance path 127 and the reverse conveyance path 128. The conveyance roller 132 conveys the paper 112 from the conveyance path 127 to the reverse conveyance path 128. The reverse conveyance path 128 is a path for reversing the conveyance direction of the paper 112. A conveyance roller 133 is provided in the reverse conveyance path 128, and the paper 112 is conveyed in the direction of the arrow 134 in the reverse conveyance path 128 and then temporarily stopped. Thereafter, the transport roller 133 rotates in the reverse direction, and transports the paper 112 in the direction of the arrow 135 opposite to the direction of the arrow 134. The reverse conveyance path 128 is connected not only to the conveyance path 127 but also to the conveyance path 129. With the branching claw 136 arranged at the branch, the sheet 112 conveyed in the direction of the arrow 135 is guided to the conveyance path 129. In the transport path 129, the paper 112 is transported by the transport rollers 137 and 138, and the paper 112 is returned to the image forming unit 102 through the transport path 114.

  A guide plate 139 is provided on the reverse conveyance path 128 in order to adjust the position of the paper 112 in the width direction. As described above, when the paper 112 is switched back, the guide plate 139 contacts the side edge of the paper 112 to adjust the position of the paper 112 in the width direction.

  FIG. 2 is a perspective view of the guide plate 139. Although the left side structure is omitted in this figure, a guide plate 139 is also provided symmetrically on the left side. When the user designates the size of the paper 112 during printing, the guide plate 139 moves in the direction of arrow A (paper width direction) according to the size of the paper 112 and the side plate 201 of the guide plate 139 contacts the paper 112. Touch. When the guide plates 139 on both sides come into contact with the paper 112, the paper 112 is aligned with the center position in the paper width direction.

  FIG. 3 is a view of the guide plate 139 as viewed from above. The guide plate 139 is connected to the gear 301 at its inner side end. A pin 302 is erected on the gear 301, and the pin 302 is inserted into a guide groove 303 disposed on the inner side end of the guide plate 139. When the gear 301 rotates, the pin 302 slides along the guide groove 303 provided in the arrow B direction, and accordingly, the guide plate 139 moves in the arrow A direction. A protruding piece 304 is disposed on the outer side end of the guide plate 139. The protruding piece 304 is used for detecting the guide plate 139 at the home position H. The home position H is a position where the width of the conveyance path is maximized. For example, the position of the guide plate 139 can be adjusted in accordance with the width of the sheet by moving the guide plate 139 by an amount determined from the size in the width direction of the sheet with reference to the position.

  FIG. 4 is a diagram for explaining the detection of the guide plate. In order to detect the guide plate 139 at the home position H, for example, an optical sensor 401 is provided on the side wall of the conveyance path. The optical sensor 401 is disposed at a location facing the protruding piece 304 of the guide plate 139. While the guide plate 139 is within a predetermined distance C from the side wall, the protruding piece 304 is positioned on the optical path of the optical sensor 401. Since the home position is located in the section, when the guide plate 139 is at the home position, the protruding piece 304 is located on the optical path of the optical sensor 401. When the guide plate 139 moves in the paper width direction and moves away from the section, the protruding piece 304 is removed from the optical path of the optical sensor 401. Accordingly, the sensor 401 detects the guide plate 139 in a detection section including the home position of the guide plate 139. Using this sensor 401, the guide plate 139 is moved to the home position.

  FIG. 5 is a diagram for explaining the relationship between the rotation of the gear for adjusting the position of the guide plate and the position of the guide plate in the paper width direction. 5A shows the position in the paper width direction, and FIG. 5B shows the relationship between the adjustment gear and the position in the paper width direction. When the adjustment gear 301 rotates in the direction of arrow D, the guide plate 139 moves in the direction of arrow E, for example, and approaches the position R1 in the paper width direction. When the adjustment gear 301 further rotates, the guide plate 139 reaches the position R1, and the sensor 401 detects the guide plate 139. The guide plate 139 passes through the position R1 and eventually reaches the home position H. When the adjustment gear 301 further rotates, the guide plate 139 moves away from the home position H and moves in the direction opposite to the arrow E. When the guide plate 139 continues to move in the direction opposite to the arrow E, the guide plate 139 returns to the position R1. The sensor 401 detects the guide plate 139 until it reaches the position R1 after reaching the position R1 first. Outside the section from the position R1 to the home position H, the sensor 401 does not detect the guide plate 139. For this reason, if the drive amount of the motor from the position R1 to the home position H can be specified, the guide plate 139 can be moved to the home position H based on the detection result of the sensor 401.

  FIG. 6 is a block diagram illustrating an example of a functional configuration of the printer. In this example, the controller 600 aligns the guide plate 139 with the home position. A gear 301 for adjusting the position of the guide plate 139 is connected to a stepping motor 601, and the stepping motor 601 drives the adjustment gear 301 in accordance with a drive signal from the drive circuit 602. The controller 600 outputs a control signal to the drive circuit 602 to control the stepping motor 601.

  In the controller 600, a sensor 401 is connected to the data acquisition unit 604. The data acquisition unit 604 counts the number of pulses to the stepping motor 601 while the guide plate 139 is detected by the sensor 401. The determination unit 605 determines whether data having a normal number of pulses has been acquired. A storage unit 606 such as a nonvolatile memory is connected to the determination unit 605. The storage unit 606 stores data on the number of pulses to the stepping motor 601 while the guide plate 139 is detected by the sensor 401. In this embodiment, the storage unit 606 stores data on the average value of the number of pulses. The determination unit 605 performs determination based on the average value data on the storage unit 606 and the data from the data acquisition unit 604.

  When it is determined that the data has been normally acquired, the guide plate movement control unit 603 moves the guide plate 139 to the home position based on the data acquired by the data acquisition unit 604, and moves the guide plate 139 to the home position. Align to. When the size of the conveyed paper in the width direction is input from the size setting unit 615, the guide plate movement control unit 603 moves the guide plate 139 from the home position according to the size, and the guide plate 139 moves in the paper width direction. Adjust the position.

  Further, when it is determined that the data has been normally acquired, the statistical value calculation unit 607 calculates an average value of the number of pulses based on the data acquired by the data acquisition unit 604 and the data on the storage unit 606, The data in the storage unit 606 is updated using the calculated value.

  If it is determined that data has not been acquired normally, the retry unit 608 repeats the determination. For this purpose, the guide plate movement control unit 603 moves the guide plate 139 again, and the data acquisition unit 604 counts the number of pulses to the stepping motor 601. When the number of pulses while the guide plate 139 is detected by the sensor 401 is counted, the determination unit 605 determines based on the data. If data is not normally acquired even if the determination is repeatedly performed according to the instruction from the retry unit 608, the defect notification unit 609 outputs a notification of misalignment. For example, a message is displayed on the display panel 610 or a warning sound is output from the speaker 611.

  In this embodiment, the controller 600 includes a data matching confirmation unit 613 and a checksum calculation unit 614 in order to ensure the validity of the data stored in the storage unit 606.

  FIG. 7 is a diagram illustrating a configuration example of the storage unit. In this embodiment, the storage unit 606 includes two average value storage areas 701 and 702, two checksum areas 703 and 704, and a measurement count storage area 705. The average value storage areas 701 and 702 store average value data of the number of pulses required for the guide plate 139 to move to the home position after the sensor 401 detects the guide plate 139. By storing data in the two areas, the stored value is protected even when there is an error when writing to the nonvolatile memory. Checksum areas 703 and 704 store checksums of data stored in average value storage areas 701 and 702, respectively. The measurement count storage area 705 stores data of past measurement counts. This data is used to calculate the average number of pulses.

  The data matching check unit 613 checks whether the average values stored in the storage areas 701 and 702 match when the power is turned on. If there is a difference in data between the storage area 701 and the storage area 702, the checksum calculation unit 614 calculates a checksum for the data in each area and compares it with the values stored in the areas 703 and 704. If the checksum is correct, the correct average value is written to the other storage area. If the average value is different and the checksum is correct for any area, or if the checksum is incorrect for any area, the value of the predetermined storage area is set to the other storage area. And set the measurement count to “1”.

  FIG. 8 is a flowchart for explaining an example of a procedure for moving the guide plate to the home position. The controller 600 starts specifying the home position, for example, when the power supply management unit 612 is notified that the printer 101 is powered on. Then, the guide plate movement control unit 603 checks whether or not the guide plate 139 is within the detection section (step S801). The confirmation may be performed based on whether the sensor 401 detects the guide plate. When the guide plate 139 is already in the detection section, the number of pulses required for the sensor 401 to move to the home position after detecting the guide plate 139 cannot be specified. In that case, the controller 600 drives the motor 601 until the sensor 401 no longer detects the guide plate 139, thereby moving the guide plate 139 once outside the detection section. The controller 600 drives the motor 601 (step S802), and determines whether the sensor 401 detects the guide plate 139 (step S803). If the sensor 401 does not detect the guide plate 139, the guide plate 139 has moved out of the detection section.

  If the guide plate 139 is outside the detection section, the controller 600 drives the motor (step S804) to bring the guide plate 139 closer to the detection section. When the sensor 401 detects the guide plate 139 due to the movement of the guide plate 139 (step S805), the data acquisition unit 604 counts the number of pulses to the stepping motor 601 (step S806). This counting is continued while the sensor 401 detects the guide plate 139. When the guide plate 139 moves outside the detection section, the sensor 401 does not detect the guide plate 139 (No in step S805). As a result, the counting ends, and the number of pulses required for the guide plate 139 to move in the detection section is acquired. The storage unit 606 stores data on the average value of the number of pulses acquired in the past as described above. The determination unit 605 calculates an error between the number of pulses counted by the data acquisition unit 604 and the average value in the storage unit 606, and determines whether the calculated error is within an allowable range (step S807).

  If this error is outside the allowable range, the retry unit 608 confirms whether the number of times that it has been determined to be outside the allowable range in the past does not exceed the allowable number (for example, 3 times) (No in step S807 → S808). If the allowable number of times is not exceeded, steps S801 to S807 are repeated. On the other hand, if it exceeds the allowable number of times, it is considered that the guide plate has a defect in movement due to gear slipping, etc., so the retry unit 608 activates the defect notification unit 609 and aligns with the display panel 610. Notification is made by displaying a defective error or outputting a warning sound through the speaker 611 (step S809). Note that the retry unit 608 may be programmed to check whether the set time has elapsed by repeating the above series of operations instead of checking whether the allowable number of times has been exceeded.

  When it is determined that the error is within the allowable range, the guide plate movement control unit 603 moves the guide plate 139 to the home position after the sensor 401 detects the guide plate 139 based on the counted number of pulses. The number of pulses required for the calculation is calculated (step S810). If the error is 0, half of the counted number of pulses is obtained as the number of pulses. If the error is 0 or more and within the allowable range, the error is corrected by adding half of the error to the counted number of pulses and setting the half of the added value as the number of drive pulses.

  When the sensor 401 detects the guide plate 139 after calculating the number of drive pulses (step S811), the data acquisition unit 604 counts the number of pulses after the detection (step S812). Then, the guide plate movement control unit 603 checks whether or not the counted number of pulses is equal to or greater than the calculated number of drive pulses (step S813). If the counted number of pulses is smaller than the calculated drive pulse (No in step S813), steps S811 and S812 are repeated and the count is continued. When the counted number of pulses is equal to or greater than the calculated number of drive pulses (step 813 Yes), the guide plate movement control unit 603 stops driving the motor 601 (step S814). As a result, the guide plate 139 is aligned with the home position. If the amount of movement of the guide plate 139 is determined in accordance with the sheet width after the guide plate 139 is aligned with the home position in this way, the position of the guide plate 139 can be adjusted appropriately.

  For example, when the guide plate 139 is aligned with the home position, the statistical value calculation unit 607 calculates a new average value from the data of the number of pulses counted in step S806 and the data in the storage unit 606 (step S815). The average value in the storage unit 606 is updated with the calculated average value (step S816). Here, the average value is obtained by dividing (measurement count × past average value + number of pulses counted in the first round) by (measurement count + 1). Data on the past average value and the number of measurements is acquired from the storage unit 606.

  As described above, in the paper transport device and the image forming apparatus according to the present embodiment, the guide plate is aligned with the reference position using normally acquired data. As a result, it is ensured that the guide plate is accurately aligned with the reference position, so that the position and orientation in the width direction of the sheet can always be appropriately adjusted by the guide plate.

  The embodiments described above do not limit the technical scope of the present invention, and various modifications and applications other than those already described are possible within the scope of the present invention. For example, instead of applying the present invention to a printer. The present invention can also be applied to other image forming apparatuses such as copying machines, facsimile machines, and multifunction machines.

  In the sheet conveying apparatus and the image forming apparatus according to the present invention, the guide plate can be accurately aligned with the reference position such as the home position, and the position and orientation in the width direction of the sheet can be adjusted appropriately. This is useful for various image forming apparatuses such as a multifunction peripheral and a multifunction peripheral.

1 is an internal structure diagram of an image forming apparatus of the present invention. The perspective view of the sheet conveying apparatus of this invention. FIG. 6 is an operation explanatory view of a guide plate in the sheet conveying apparatus of the present invention. Explanatory drawing of the reference position detection in the sheet conveying apparatus of this invention. FIG. 6 is an operation explanatory view of a guide plate in the sheet conveying apparatus of the present invention. 1 is a block configuration diagram of an image forming apparatus of the present invention. 2 is a configuration example of a storage unit in the image forming apparatus of the present invention. 6 is a flowchart showing the operation of the sheet conveying apparatus of the present invention.

Explanation of symbols

139 Guide plate 401 Sensor 601 Stepping motor 602 Drive circuit 603 Guide plate movement control unit 604 Data acquisition unit 605 Determination unit 606 Storage unit 607 Statistical value calculation unit 608 Retry unit 609 Defect notification unit 610 Display panel 611 Speaker 612 Power supply management unit 613 Data consistency check unit 614 Check sum calculation unit 615 Size setting unit

Claims (8)

A guide plate provided so as to be capable of reciprocating in the width direction of the sheet;
A motor for driving the guide plate;
A sensor for detecting the guide plate in a detection section including a reference position of the guide plate;
A data acquisition unit for acquiring data of a drive signal to the motor when the guide plate is moved to the detection section;
A storage unit for storing the data of the drive signal;
A determination unit that determines whether normal data is acquired based on a statistical value obtained from the stored data and a value of the acquired data;
A sheet conveying apparatus comprising: a guide plate movement control unit that aligns the guide plate with the reference position using data acquired normally and moves the guide plate from the reference position according to the width of the sheet.   The sheet conveying apparatus according to claim 1, further comprising a retry unit that acquires data of the drive signal and repeats the determination when normal data is not acquired in the determination of the determination unit.   The sheet conveying apparatus according to claim 2, further comprising a defect notifying unit that notifies misalignment when normal data is not acquired even if the determination is repeated.   When normal data is acquired, the guide plate movement control unit corrects the value of the data based on an error between the value of the data and the statistical value, and the guide plate is moved using the corrected data. The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is aligned with the reference position.   The sheet conveying apparatus according to claim 1, wherein the drive signal data to the motor is pulse number data to the stepping motor. A pair of guide plates provided so as to be capable of reciprocating in the width direction of the sheet;
A stepping motor for driving the guide plate;
A sensor for detecting the guide plate in a section including a reference position where the distance between the guide plates is maximum;
A data acquisition unit for acquiring data relating to the number of pulses to the stepping motor while the sensor is detecting the guide plate;
A storage unit for storing data relating to the number of pulses;
A determination unit that determines whether normal data is acquired based on a statistical value obtained from the stored data and a value of the acquired data;
A sheet conveying apparatus comprising: a guide plate movement control unit that aligns the guide plate with the reference position using data acquired normally and moves the guide plate from the reference position according to the width of the sheet.   The sheet conveying apparatus according to claim 6, wherein the sensor is an optical sensor having a detection width in a width direction of the sheet. An image forming apparatus comprising the sheet conveying device according to claim 1.

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