JPH10250880A - Sheet carrier device and control method of sheet carrier device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To complete biased movement correction and sheet-to-sheet distance correction of sequentially carried sheet materials in a short period of time. SOLUTION: Under a control method of this sheet carrier device, original detection sensors 15, 16 detect a carrying state of originals sequentially carried by pulse motors 11, 12 respectively rotationally driven independently, a bias movement computation part 301 and a sheet-to-sheet distance computation part 303 respectively compute a bias moving direction, bias moving quantity and a sheet-to-sheet distance of each sheet material from the detected carrying state of the originals, and a bias movement correction control part 302 carries out bias movement correction with sheet-to-sheet distance correction by controlling a driving state of the pulse motors 11, 12 in parallel in accordance with these computed bias moving direction of the originals, bias moving quantity, the sheet-to-sheet distance of each of the sheet materials.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying device for sequentially conveying sheet materials at predetermined intervals and a method for controlling the sheet conveying device.

[0002]

2. Description of the Related Art Conventionally, a paper transport device such as an automatic document feeder (ADF) mounted on an image forming apparatus such as a copying machine has been known.
It has a function of correcting skew of a document before sending the document to an image reading unit that reads an image of a conveyed document. In such a paper transport apparatus, a transport roller pair and a document detection sensor are provided on the left and right in a width direction orthogonal to the transport direction, respectively.
The rotation speed of each motor that drives the pair of transport rollers in accordance with the skew amount of the document calculated from the detection information of the document detection sensor is determined by one of (A) to (C) shown in FIG. By changing the skew, the skew of the document is corrected.

FIG. 9 is a schematic diagram for explaining a method of correcting skew of a sheet material conveyed by a conventional sheet conveying device.

As shown in the drawing, the conventional skew correction control method includes a deceleration control method in which the skew correction is performed by decelerating the feed roller L1 on the leading side of the document (arrow D in the figure). (A), an acceleration control method (B) for accelerating the conveying roller L2 on the side where the document is delayed (arrow A in the figure) to perform skew correction, and decelerating the conveying roller L1 on the preceding side. There is an acceleration / deceleration control method (C) for simultaneously performing acceleration (arrow D in the figure) and acceleration of the transport roller L2 on the side that is delayed (arrow A in the figure).

Reference numerals 15 and 16 denote document detection sensors which measure the skew direction, the detected skew amount Nb, and the like of the document conveyed by the conveyance rollers L1 and L2. Usually, a pulse motor is used as a motor for rotating and driving the transport roller pair, and the detection skew amount Nb is determined by the document detection sensor 15 and
The time from when one of the right and left 16 sensors detects a document to when the other sensor detects the document is measured by counting the clocks for driving the pulse motors PM1 and PM2.

Further, since the original detection sensors 15 and 16 are arranged at equal distances to the left and right from the center of the original conveyance path in the width direction, the original detection sensors 15 and 16 correspond to the detected skew amount Nb calculated from the detection information of the detection sensors. When the skew control is performed, the document is delayed by Nb / 2 from the normal conveyance at the central portion in the width direction of the document in the case of the deceleration control method shown in FIG.
In the case of the acceleration control method shown in (1), the original is advanced by Nb / 2 compared with the normal conveyance, and in the case of the acceleration / deceleration control method shown in (C), the original is not different from the normal conveyance.

Further, if the roller diameters of the left and right transport roller pairs differ due to the tolerance of the transport rollers L1 and L2 or wear due to long-term use, the original is excessively skewed during transport, and the original is skewed. This affects the image read by the reading unit. For this reason, a document detection sensor is provided to calculate the skew displacement direction and the skew displacement amount during transport, and to change the drive clocks applied to the left and right pulse motors PM1 and PM2, thereby keeping the left and right document transport speeds constant. I was

[0008]

However, the ADF
When a document is continuously transported using a paper transport device such as the above, in the above-described conventional skew feeding correction method, as described above, the interval between the document and a previously fed document is changed by the skew feeding correction control. In addition, it is necessary to perform the sheet interval control after the skew feeding correction control, and these have a problem in that they reduce the throughput of the sheet material to be conveyed synergistically.

Further, when a difference occurs in the roller diameter of the pair of left and right transport rollers due to tolerance of the transport rollers or wear due to long-term use, the driving clock for driving the pulse motor is changed and differs between the left and right. However, the skew amount cannot be measured accurately, and as a result, accurate skew correction cannot be performed.

The present invention has been made to solve the above problems, and a first object of the first to ninth inventions according to the present invention is to provide a sheet material having a width perpendicular to a conveying direction of a sheet material. The conveyance state of the sheet material sequentially conveyed is detected by a plurality of driving means independently rotating on both sides on the same straight line in the direction, and the skew direction of the sheet material, the skew amount, and each sheet material are determined from the conveyance state. And the driving state of the driving means is controlled in parallel based on the calculated skew direction and skew amount of the sheet material, and the space between the sheet materials.
The second purpose is to complete the skew correction and the sheet interval correction of the sequentially conveyed sheet material in a short time, and independently on both sides on the same straight line in the width direction orthogonal to the sheet material conveyance direction. The conveyance state of the sheet material sequentially conveyed by the plurality of driving units that are rotationally driven is detected, the skew direction of the sheet material is determined from the conveyance state, and the skew direction of the sheet material is determined based on the skew direction of the determined sheet material. Select one of the drive units to be line-corrected, calculate the skew amount of the sheet material with respect to the selected drive unit from the conveyance state of the sheet material, and calculate the skew amount based on the calculated skew amount. By controlling the correction drive for the selected drive unit and the normal drive for the other drive units in parallel, even if there is a difference between the left and right roller diameters of the pair of transport rollers for transporting the sheet material, a simple configuration is possible. Accurate It is to provide a control method of the paper conveying apparatus and a sheet conveying device capable of performing line correction.

[0011]

According to a first aspect of the present invention, a sheet material (paper, document) is rotated independently on both sides on the same straight line in a width direction perpendicular to a conveying direction, and the sheet material is independently driven. A plurality of driving means (pulse motors 11 and 12) for sequentially transporting the sheet material; a detecting means (document detection sensors 15 and 16) for detecting a transport state of the sheet material transported by the rotation of each of the driving means; From the state of conveyance of the sheet material by the detecting means, the skew direction of the sheet material,
Calculating means (a skew amount calculating unit 301 and a sheet interval calculating unit 303) for calculating a skew amount N and a sheet interval X of each sheet material, respectively, and a skew direction of the sheet material calculated by the calculating unit;
Control means for controlling the driving states of the respective driving means in parallel based on the skew amount N and the sheet interval X of each sheet material to perform skew correction with sheet interval correction (control operation section 304, control method selector section) 305, a skew feed correction control unit 302).

In a second aspect according to the present invention, the control means is configured to determine the skew direction, the skew amount N, and the sheet interval X of each sheet material calculated by the calculation means. First drive control in which acceleration drive of one of the drive units and normal drive of the other drive unit are performed in parallel (FIG. 9B)
And a second drive control (deceleration control shown in FIG. 9A) in which deceleration drive of any one of the drive units and normal drive of another drive unit are performed in parallel. Third drive control in which acceleration drive of any one of the drive units and deceleration drive of another drive unit are performed in parallel (FIG. 9C).
(Acceleration / deceleration control shown in FIG. 1).

According to a third aspect of the present invention, the control means outputs a warning when the sheet interval of each sheet material calculated by the calculation means deviates from a predetermined range.

According to a fourth aspect of the present invention, a plurality of sheets for sequentially transporting the sheet material (sheets, originals) by sequentially rotating and driving each independently on both sides on the same straight line in the width direction orthogonal to the transport direction of the sheet material (paper, document). Driving means (pulse motors 11, 12)
Detection means (document detection sensors 15 and 16) for detecting a conveyance state of the sheet material conveyed by the rotational driving of each of the driving means; and an inclination of the sheet material based on the conveyance state of the sheet material by the detection means. Discriminating means (skew direction discriminating section 722) for discriminating the row direction, and selecting means for selecting any one of the drive means to be subjected to the skew correction based on the skew direction of the sheet material determined by the discriminating means. (Reference clock selector unit 723) and calculation means (Skew amount counter unit 724) for calculating the skew amount of the sheet material with respect to the driving unit selected by the selection unit from the conveyance state of the sheet material by the detection unit Correction driving for the driving means selected by the selecting means based on the skew amount calculated by the calculating means, and normal driving for the other driving means. And it has a control unit (controller 725) for controlling in parallel and.

According to a fifth aspect of the present invention, the driving means is a pulse motor.

In a sixth aspect according to the present invention, the control means includes an acceleration drive for the drive means selected by the selection means based on the skew amount calculated by the calculation means, and an acceleration drive for another drive means. This controls the normal driving in parallel.

According to a seventh aspect of the present invention, the control means includes a deceleration drive for the drive means selected by the selection means based on the skew amount calculated by the calculation means and a control for other drive means. This controls the normal driving in parallel.

According to an eighth aspect of the present invention, there is provided an apparatus for detecting the conveying state of the sheet material sequentially conveyed by driving means for independently rotating and driving both sides on the same straight line in the width direction perpendicular to the conveying direction. And a skew direction, a skew amount, and a skew amount of the sheet material from the detected conveyance state of the sheet material.
A calculation step (step (1) in FIG. 4) for calculating the sheet interval of each sheet material, and each of the sheet materials based on the calculated skew direction, skew amount, and sheet interval of each sheet material. A driving step of driving the driving means in parallel (step (3) in FIG. 4,
(5), (7)).

According to a ninth aspect of the present invention, there is provided a method for detecting the state of conveyance of the sheet material sequentially conveyed by drive means which are independently driven to rotate on both sides on the same straight line in the width direction orthogonal to the conveyance direction of the sheet material. 6 (a step (not shown) before step (1) in FIG. 6), and a discrimination step (step (FIG. 6) in which the skew direction of the sheet material is discriminated from the detected conveyance state of the sheet material. 1)) and a selection step (steps (2) and (5) in FIG. 6) of selecting any one of the driving units to be skew-corrected based on the determined skew direction of the sheet material. A calculating step of calculating the skew amount of the sheet material with respect to the selected driving unit from the detected conveyance state of the sheet material (step (3) in FIG. 6,
(6), step (2) in FIG. 7, step (2) in FIG. 8), correction driving for the selected driving unit and normal driving for other driving units based on the calculated skew amount. Are performed in parallel (steps (4) and (7) in FIG. 6, step (5) in FIG. 7, and step (5) in FIG. 8).

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] FIG. 1 is a block diagram for explaining a control configuration of a sheet conveying apparatus according to a first embodiment of the present invention.
The same components as those in FIG. 9 are denoted by the same reference numerals.

Referring to FIG. 1, reference numeral 301 denotes a skew amount calculating unit which receives detection information from the document detection sensors 15 and 16 and calculates the skew direction and the skew amount N of the transport paper. Reference numeral 303 denotes a sheet interval calculation unit that receives the detection information from the document detection sensors 15 and 16 and calculates the sheet interval X of each sheet sequentially conveyed. 30
Reference numeral 4 denotes a control operation unit that receives the skew amount N and the sheet interval X calculated by the skew amount operation unit 301 and the sheet interval operation unit 303 and performs an operation on the skew amount N and the sheet interval X.

Reference numeral 305 denotes a control method selector unit which receives the operation result transmitted from the control operation unit 304 and
(A) to (C), one of the three skew control methods (deceleration control method, acceleration control method, acceleration / deceleration control method) is selected, and the control method signal is sent to the skew correction control unit 302. Send. If the control method selector unit 305 determines that the optimum paper interval correction cannot be performed using any of the three skew feeding correction methods, the control method selector unit 305 outputs an error signal instead of the control method signal. The data is transmitted to the row correction control unit 302.

The skew correction control unit 302 controls the left and right motors based on the control method signal transmitted from the control method selector unit 305, the skew direction signal transmitted from the skew amount calculation unit 301, and the skew amount N. The skew correction accompanying the sheet interval correction of the conveyed sheet material is controlled by adjusting the number of drive pulses applied to the sheets 11 and 12.

The above-mentioned reference numerals 301 to 305 denote CPU, RO
It may be configured by a controller including M and RAM and controlled according to the procedure of a flowchart described later.

In calculating the skew amount N, first, the time from when one of the left and right sensors of the document detection sensors 15 and 16 detects a document to when the other sensor detects the document is determined. The detection skew count number Csk is measured by counting at a constant frequency f. Next, the amount of skew Nb detected by the sensor unit is calculated as Nb = Csk *
It is calculated by V / f. The skew amount N of the roller unit actually used by the control unit 302 to control the pulse motors 11 and 12 is determined by the skew amount Nb detected by the document detection sensor, the distance a between the conveyance rollers, and the distance b between the document detection sensors. (Shown in FIG. 2 which will be described later) using N = Nb * b / a.
Next, the controller 1 controls the drive pulses of the pulse motors 11 and 12 based on the skew amount N, thereby correcting and controlling the skew with the sheet interval correction of the transported paper.

Here, the document detection sensors 15 and 16 are arranged as means for detecting a sheet material as a document. However, the present invention is not limited to the above-described document detection sensors 15 and 16, and is not limited thereto. Alternatively, the original may be detected using a CCD or the like. The sheet material also includes an OHP film sheet, cardboard, an envelope, and the like.

FIG. 2 is a schematic diagram for explaining an arrangement state of each part of the sheet conveying apparatus shown in FIG. 1, and the same components as those in FIG. 1 are denoted by the same reference numerals.

In the figure, pulse motors 11 and 12 are
The rollers are independently driven to rotate on both sides on the same straight line in the width direction which is directly connected to the sheet conveyance direction, and the active rollers 13 and 14 are driven to rotate as driving means. The document detection sensors 15 and 16 are provided at the center in the document width direction on the document conveyance path to measure the skew direction, the skew amount N, and the sheet interval X of the document conveyed by the active rollers 13 and 14. Are arranged at equal distances to the left and right.

FIG. 3 is a schematic diagram for explaining a sheet interval detecting method of the sheet conveying apparatus shown in FIG. 1, and the same components as those in FIG. 1 are denoted by the same reference numerals.

In the figure, the time from when the document detection sensors 15 and 16 detect the trailing edge of the document 1 for which the skew correction has been completed to when the leading edge of the document 2 to be conveyed next is detected is a constant frequency. The count C between sheets is measured by counting with the pulse signal of f. Here, the leading edge detection of the original 2 is detected by the original detection sensor (the preceding original detection sensor) of the left and right original detection sensors that has been detected first. Assuming that the transport speed of the original 1 and the original 2 is V, the sheet interval Xs of the original detection sensor unit is represented by Xs = C * V / f.

Therefore, the sheet interval X at the center in the width direction of the transport path is obtained.
Is calculated as X = Xs + Nb / 2 using the sheet interval Xs of the document detection sensor unit and the detected skew amount Nb.

Hereinafter, the skew feed correction control operation involving the sheet interval correction of the sheet conveying apparatus of the present invention will be described with reference to the flowchart shown in FIG.

FIG. 4 is a flow chart for explaining a skew feeding correction control procedure involving a sheet interval correction of the sheet conveying apparatus of the present invention. (1) to (8) indicate each step.

In the drawing, the proper range of the sheet interval X is represented by Xo ± Xm using the optimum value Xo of the sheet interval and the margin Xm.

First, when the document detection sensors 15 and 16 detect a document, the skew amount detection unit 301 sets the skew direction and the skew amount N.
Is calculated, and the sheet interval calculation unit 303 calculates the sheet interval X (1). Next, the control method selector unit 305 determines whether or not the sheet interval X is within the range of Xo−Xm ≦ X ≦ Xo + Xm (2). 305 transmits an acceleration / deceleration control method signal to the skew feed correction control unit 302, and the skew feed correction control unit 302 sends the skew feed amount N
The skewed sheet interval correction is performed using the acceleration / deceleration control method in which the sheet interval does not change irrespective of the value of (3), and the process ends.

On the other hand, if it is determined in step (2) that the sheet interval X is not in the range of Xo−Xm ≦ X ≦ Xo + Xm, X + N / 2 calculated from the sheet interval X and the skew amount N.
Is determined to be within a range of Xo−Xm ≦ X + N / 2 ≦ Xo + Xm (4). If it is determined that the range is within the range, the control method selector unit 305 causes the skew correction control unit 302 to
To the skew feed correction control unit 302
Performs the skewed sheet interval correction using the deceleration control method in which the sheet interval becomes longer by N / 2 (5), and ends the processing.

On the other hand, in step (4), X + N / 2 calculated from the sheet interval X and the skew amount N is Xo−Xm ≦ X +
If it is determined that the range is not in the range of N / 2 ≦ Xo + Xm,
X−N / 2 calculated from the sheet interval X and the skew amount N is Xo−X
It is determined whether or not the range is m ≦ X−N / 2 ≦ Xo + Xm (6). If it is determined that the range is within the range, the control method selector unit 305 causes the skew correction control unit 302 to perform an acceleration control method. The skew feed correction control unit 302 transmits a signal and the sheet interval is N / N.
The skewed sheet gap correction is performed by using the acceleration control method that is shortened by 2 (7), and the process ends.

On the other hand, in step (6), X−N / 2 calculated from the sheet interval X and the skew amount N is Xo−Xm ≦ X−
If it is determined that the range is not in the range of N / 2 ≦ Xo + Xm,
The control method selector unit 305 transmits a warning (error signal) indicating that the sheet interval control is impossible to the skew feeding correction control unit 302,
The skew correction control unit 302 controls the conveyance of the document to be stopped, displays the stop to the operator (8), and ends the processing.

As described above, the driving states of the pulse motors 13 and 14 are controlled in parallel according to the skew direction, the skew amount N, and the sheet interval X calculated based on the detection of the conveyed sheet, and the skew correction control is performed. And the sheet interval control are performed at the same time, the sheet can be conveyed in a state where the sheet interval X is constant and the skew is corrected.

[Second Embodiment] In the first embodiment, the skew direction calculated by detecting the sheet being conveyed,
The configuration has been described in which the drive means is controlled in parallel based on the skew amount and the sheet interval to perform skew correction control with sheet gap correction. The driving means to be selected may be selected, and the skew correction may be performed based on the skew amount calculated for the selected driving means. Hereinafter, the embodiment will be described.

FIG. 5 is a block diagram illustrating a control configuration of a sheet transporting apparatus according to a second embodiment of the present invention. The same components as those in FIG. 2 are denoted by the same reference numerals.

In the figure, reference numeral 721 denotes a reference clock generation unit which generates a reference clock having a predetermined frequency related to a driving clock for driving the left and right pulse motors 11 and 12, respectively. The reference clock generation unit 721 generates the left and right reference clocks by a control signal (not shown) from the document detection sensors 15 and 16 so that the sheet material as the document does not skew due to the tolerance of the left and right rollers or the depletion due to long-term use. Variable. Reference numeral 722 denotes a skew direction discrimination unit, and 724 denotes a skew amount counter unit, which calculates the skew direction and skew amount of the document from the detection information transferred from the document detection sensors 15 and 16.

The document detecting sensor 1
5 and the document detection sensor 16, the skew direction is determined, and the skew direction (whether left or right) of the document is defined as binary information of “1” or “0”. The data is transmitted to the reference clock selector 723 and the controller 725.
The reference clock selector unit 723 is to correct based on the skew direction information transmitted from the skew direction discrimination unit 722 (so that the skew amount of the document is measured by the reference clock on the controlling side). Select one of the left and right reference clocks. The skew feed counter 724 counts the detected skew feed Nb of the document using the reference clock selected by the reference clock selector 723. The skew amount counter 724 transmits the detected skew amount Nb to the controller 725 immediately after the measurement of the detected skew amount Nb is completed. The control unit 725 does not perform normal clock control until receiving the skew direction and the detected skew amount Nb from the skew direction discrimination unit 722 and the skew amount counter unit 724, and controls the right reference clock and the left reference clock, respectively. The frequency dividing or right driving clock and the left driving clock are output to the pulse motors 11 and 12 as they are, and the left and right pulse motors 11 and 12 are driven.

Next, when the control unit 725 receives the skew direction and the detected skew amount Nb, the control unit 725 calculates the skew amount N from the detected skew amount Nb based on the calculation formula N = Nb * b / a. And
If the received skew direction signal is, for example, information indicating that the right side of the document is skewed ahead, the deceleration control method (decelerates the skewed feed roller by decelerating the conveyance roller on the front side) Is performed, the right reference clock is controlled and the right drive clock is decelerated by the skew amount N to perform skew correction.

When the acceleration control method (a control method for accelerating the skew feeding by accelerating the transport roller on the lag side) is used, the left driving clock is accelerated by the skew amount N to perform the skew correction. Do. As described above, the control unit 725 controls the left or right driving clock based on the skew direction and the skew amount N of the document to perform skew correction. At this time, a drive pulse corresponding to normal motor drive is given to one of the motors not to be corrected.

The above-mentioned 721 to 725 are CPU, RO
It may be configured by a controller including M and RAM and controlled according to the procedure of a flowchart described later.

In calculating the skew amount N, the time from when one of the left and right sensors of the document detection sensors 15 and 16 detects a document to when the other sensor detects the document is determined. The detection skew amount Nb is measured by counting with a clock for driving the pulse motors 11 and 12. Actually, the controller 1 operates the pulse motors 11, 1
The skew amount N of the roller unit used to control the number 2 is calculated by using the detected skew amount Nb detected by the document detection sensor, the distance a between the conveying rollers, and the distance b between the document detection sensors.
It is calculated by b / a.

As described above, the control section 725 corrects the skew of the conveyed paper by controlling the drive clock of either the left or right pulse motor by the skew amount N. Here, the document detection sensors 15 and 16 are arranged as means for detecting a sheet material such as a document.
However, the present invention is not limited to the embodiments described above. For example, a configuration may be adopted in which a document is detected using a CCD or the like instead of the sensor.

Hereinafter, the skew feeding correction control operation of the sheet conveying apparatus according to the present invention will be described with reference to the flowcharts of FIGS.

FIG. 6 is a flowchart for explaining the skew feeding correction control procedure of the sheet transporting apparatus according to the present invention.
A case in which skew correction is performed by a deceleration control method (a control method of decelerating a transport roller on the leading side of a sheet) will be described. Note that (1) to (7) indicate each step.

First, either the left or right original detection sensor 1
The original is detected by the skew direction 5 and the skew direction determining unit 722.
When the reference clock selector unit 723 receives the skew direction signal, the reference clock selector unit 723 determines whether the document is skewed in the left or right direction (1). If it is determined that the clock signal is detected, the right reference clock is selected, and the right reference clock is output to the skew amount counter (2). The skew amount counter 724 calculates the skew amount N based on the right reference clock and the detection information from the document detection sensor (3), and transmits the skew amount N to the control unit 725. The control unit 725 that has received the skew amount N from the skew amount counter unit 724 performs deceleration control of the right drive clock (right drive clock control shown in FIG. 7 described later) to perform skew correction based on the skew amount N ( 4), end the process.

On the other hand, if it is determined in step (1) that the right side of the document is not skewed ahead (the left side of the document is skewed ahead), the reference clock selector unit 723 determines The left reference clock is selected (5) and output to the skew amount counter 724. The skew amount counter unit 724 calculates the skew amount N based on the left reference clock and the detection information from the document detection sensor (6), and transmits the calculated skew amount N to the control unit 725. The controller 725 performs deceleration control of the left drive clock (left drive clock control shown in FIG. 8 described later) to perform skew correction based on the skew amount N (7), and ends the processing.

FIG. 7 is a flowchart for explaining the detailed procedure of the right drive clock control shown in FIG. 6, and in particular, the deceleration control method will be described. Note that (1) to (6) indicate each step.

First, the right reference clock counter Cbr for counting the number of clocks of the right reference clock and the right drive clock counter Cdr for counting the number of clocks of the right drive clock are set to 0 (1), and the skew amount counter 724 is set.
When the detected skew amount Nb is received from N, the skew amount N is calculated from N = Nb * b / a (2), and the right drive clock counter Cd is calculated.
The skew amount N is added to r (3).

Next, the control unit 725 starts counting by the right reference clock counter Cbr and the right driving clock counter Cdr (4). The right reference clock counter Cbr is incremented by one for each pulse of the right reference clock, and the right drive clock counter Cd is added for each pulse of the right drive clock.
r is incremented by one. Next, the frequency of the right drive clock is reduced to reduce the rotation speed of the right transport roller (5). The deceleration of the right drive clock in step (5) is performed until the values of the right reference clock counter Cbr and the right drive clock counter Cdr match, and when the values of the right reference clock counter Cbr and the right drive clock counter Cdr match (6). ,
The control of the right driving clock is stopped, the right driving clock is returned to the clock frequency before the control, and the process is terminated.

FIG. 8 is a flowchart for explaining the detailed procedure of the left drive clock control shown in FIG. 6, and in particular, a deceleration control method. Note that (1) to (6) indicate each step.

First, the left reference clock counter Cbl for counting the number of clocks of the left reference clock and the left drive clock counter Cdl for counting the number of clocks of the left drive clock are set to 0 (1), and the skew amount counter 724 is set.
When the detected skew amount Nb is received from N, the skew amount N is calculated from N = Nb * b / a (2), and the left drive clock counter Cd is calculated.
The skew amount N is added to 1 (3).

Next, the control section 725 starts counting by the left reference clock counter Cbl and the left drive clock counter Cdl (4), and then reduces the frequency of the left drive clock to reduce the rotation speed of the left transport roller. (5). The deceleration of the left drive clock in step (5) is performed until the values of the left reference clock counter Cbl and the left drive clock counter Cdl match, and if the values of the left reference clock counter Cbl and the left drive clock counter Cdl match (6). ,
The control of the left driving clock is stopped, the clock frequency of the left driving clock is returned to the clock frequency before the control, and the process is terminated.

When the control unit 725 generates a drive clock by dividing the reference clock,
The skew amount N calculated from the detected skew amount Nb is divided by the divided frequency and added to the left and right driving clock counters Cdl and Cdr, and the counts of the left and right reference clock counters Cbl and Cbr are calculated by dividing the reference clock. Should be performed.

As described above, the skew amount of the conveyed document (with respect to the motor on which the drive control is performed) is calculated from the motor drive clock on the drive control side, and the deceleration drive for the motor and the normal operation for the other motors are performed. By performing control in parallel with driving, even when the left and right diameters of the roller pair that conveys the paper are different and the rotational speeds of the right and left rollers are different, it is not necessary to make new settings, and high accuracy is easily achieved. Skew correction control can be performed.

Further, in this embodiment, a deceleration control method for controlling the deceleration drive for the driving of the motor on the side obliquely preceding the conveyed document and the normal driving for the other motors in parallel. Although the skew correction control is described using the skew feed correction control, the skew feed correction is performed by using an acceleration control method that controls the acceleration drive for the motor on the side of the document being conveyed late and the normal drive for the other motors in parallel. You may comprise so that it may control.

Further, in the present embodiment, the case where the paper transporting device according to the present invention is applied to a document feeding device has been described, but a sheet material such as a recording paper transporting device for transporting recording paper to a recording section is transported. The present invention can also be applied to other transport devices that perform the above.

As described above, the storage medium storing the program code of the software for realizing the functions of the above-described embodiments is supplied to the system or the apparatus, and the computer (or CPU or MP) of the system or the apparatus is supplied.
It goes without saying that the object of the present invention is also achieved when U) reads out and executes the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the novel function of the present invention, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, C
DR, magnetic tape, nonvolatile memory card, RO
M, EEPROM and the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) And the like perform part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instructions of the program code, The CPU provided in the function expansion board or function expansion unit performs part or all of the actual processing,
It goes without saying that a case where the function of the above-described embodiment is realized by the processing is also included.

Further, the present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus. In this case, by reading a storage medium storing a program represented by software for achieving the present invention into the system or the apparatus, the system or the apparatus can enjoy the effects of the present invention. .

Further, by downloading and reading out a program represented by software for achieving the present invention from a database on a network by a communication program, the system or apparatus can be
It is possible to enjoy the effects of the present invention.

[0070]

As described above, the first embodiment according to the present invention is described.
According to the second and third aspects of the present invention, the state of conveyance of the sheet material sequentially conveyed by the plurality of driving units that rotate independently on both sides on the same straight line in the width direction perpendicular to the conveyance direction is detected. Means for detecting the sheet material from the state of conveyance of the sheet material by the detecting means,
The calculating unit calculates the skew amount and the sheet interval of each sheet material, and the control unit calculates the skew direction, the skew amount, and the sheet interval of each sheet material calculated by the calculating unit. Since the skew correction with the sheet gap correction is performed by controlling the driving states of the respective driving units in parallel, it is possible to simultaneously perform the skew correction and the sheet gap correction of the sequentially conveyed sheet material.

According to the third aspect, the control means outputs a warning when the sheet interval of each sheet material calculated by the calculating means deviates from a predetermined range. When the line correction is impossible, it is possible to notify the user.

According to the fourth invention to the seventh invention, the sheet material sequentially conveyed by a plurality of driving means independently rotating on both sides on the same straight line in the width direction orthogonal to the conveying direction of the sheet material. Detection means detects the conveyance state of the sheet material, and the discrimination means determines the skew direction of the sheet material from the conveyance state of the sheet material by the detection means, and determines the skew direction of the sheet material determined by the discrimination means. The selecting means selects any one of the driving means to be corrected based on the skew based on the
A calculating unit calculates a skew amount of the sheet material with respect to a driving unit selected by the selecting unit from a conveyance state of the sheet material by the detecting unit, and calculates the skew amount based on the skew amount calculated by the calculating unit. Since the control unit controls the correction driving for the driving unit selected by the selecting unit and the normal driving for the other driving units in parallel, even if the left and right rotation speeds of the conveying roller pair for conveying the sheet material are different. Thus, accurate skew correction control can be performed.

According to the eighth aspect, the conveyance state of the sheet material sequentially conveyed by the plurality of driving means which independently rotate and drive the sheet material on both sides on the same straight line in the width direction perpendicular to the conveyance direction is detected. Then, the skew direction, the skew amount, and the sheet interval of each sheet material are calculated from the detected conveyance state of the sheet material, and the calculated skew direction, skew of the sheet material are calculated. Since the respective driving units are driven in parallel based on the amount and the sheet interval of each sheet material, the skew correction and the sheet interval correction of the sequentially conveyed sheet materials can be performed simultaneously.

According to the ninth aspect, the conveyance state of the sheet material sequentially conveyed by a plurality of driving means which are independently driven to rotate on the same straight line in the width direction orthogonal to the conveyance direction of the sheet material is detected. Then, the skew direction of the sheet material is determined from the detected conveyance state of the sheet material, and any one of the driving units to perform the skew correction based on the determined skew direction of the sheet material is determined. Calculating a skew amount of the sheet material with respect to the selected driving means from the selected and detected conveyance state of the sheet material, and correcting the selected driving means based on the calculated skew amount; Since the driving and the normal driving for the other driving means are performed in parallel, accurate skew correction control can be performed even when the right and left rotation speeds of the conveying roller pair for conveying the sheet material are different. It made.

Therefore, the skew correction and the sheet gap correction of the sequentially conveyed sheet material can be completed in a short time, and even if the right and left roller diameters of the pair of conveying rollers for conveying the sheet material are different. Thus, it is possible to perform an accurate skew correction with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a control configuration of a sheet conveying apparatus according to a first exemplary embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating an arrangement state of each unit of the sheet transport device illustrated in FIG. 1;

FIG. 3 is a schematic diagram illustrating a sheet interval detecting method of the sheet conveying device illustrated in FIG. 1;

FIG. 4 is a flowchart illustrating a skew feeding correction control procedure involving a sheet interval correction of the sheet conveying device according to the present invention.

FIG. 5 is a block diagram illustrating a control configuration of a sheet transport device according to a second embodiment of the present invention.

FIG. 6 is a flowchart illustrating a skew feeding correction control procedure of the sheet conveying device according to the present invention.

FIG. 7 is a flowchart illustrating a detailed procedure of a right driving clock control illustrated in FIG. 6;

FIG. 8 is a flowchart illustrating a detailed procedure of left drive clock control shown in FIG. 6;

FIG. 9 is a schematic diagram illustrating a method for correcting skew of a sheet material conveyed by a conventional sheet conveying device.

[Explanation of symbols]

 Reference Signs List 11 pulse motor (right pulse motor) 12 pulse motor (left pulse motor) 15 document detection sensor (right detection sensor) 16 document detection sensor (left detection sensor) 301 skew amount calculating unit 302 skew correction control unit 303 paper interval calculation Unit 304 control operation unit 305 control method selector unit

Claims (9)

[Claims] 1. A plurality of driving means for independently rotating and driving the sheet material on both sides on the same straight line in the width direction orthogonal to the conveying direction to sequentially convey the sheet material, and conveying the sheet material by rotationally driving each of the driving means. Detecting means for detecting a transport state of the sheet material, and calculating means for calculating a skew direction, a skew amount, and a sheet interval of each sheet material from the transport state of the sheet material by the detecting means. And skew feeding with sheet gap correction by controlling the driving states of the respective driving means in parallel based on the skew direction and skew amount of the sheet material calculated by the calculation means, and the sheet interval of each sheet material. A sheet transport device comprising: a control unit that performs correction. 2. The method according to claim 1, wherein the control unit is configured to perform acceleration driving of one of the driving units based on a skew direction and a skew amount of the sheet material calculated by the calculation unit, and a sheet interval between the sheet materials. A first drive control for performing the normal drive of the drive means in parallel, a second drive control for performing the deceleration drive of one of the drive means and the normal drive of the other drive means in parallel, 2. The sheet transporting device according to claim 1, wherein any one of the third drive controls, in which acceleration drive of any one of the drive means and deceleration drive of the other drive means are performed in parallel, is selected and performed. . 3. The sheet transport device according to claim 1, wherein the control unit outputs a warning when the sheet interval of each sheet material calculated by the calculation unit deviates from a predetermined range. 4. A plurality of drive means for independently rotating and driving the sheet material sequentially on both sides on the same straight line in the width direction orthogonal to the sheet material transport direction, and sequentially transporting the sheet material, and transporting by rotating the respective drive means. Detecting means for detecting the conveyance state of the sheet material to be performed; determining means for determining the skew direction of the sheet material from the conveying state of the sheet material by the detecting means; and the sheet material determined by the determining means Selecting means for selecting one of the driving means to be corrected for skew based on the skew direction of the sheet material; and selecting the driving means selected by the selecting means from the conveying state of the sheet material by the detecting means. Calculating means for calculating the amount of skew; correcting drive for the driving means selected by the selecting means based on the amount of skew calculated by the calculating means; Sheet conveying apparatus characterized by comprising control means for controlling in parallel with normal drive to the drive means. 5. The sheet conveying device according to claim 4, wherein said driving means is a pulse motor. 6. The control unit controls the acceleration drive for the drive unit selected by the selection unit and the normal drive for another drive unit in parallel based on the skew amount calculated by the calculation unit. The paper transport device according to claim 4, wherein 7. The control unit controls the deceleration drive for the drive unit selected by the selection unit and the normal drive for another drive unit in parallel based on the skew amount calculated by the calculation unit. The paper transport device according to claim 4, wherein 8. A detecting step of detecting a conveying state of the sheet material sequentially conveyed by a plurality of driving units that rotate independently on both sides on the same straight line in the width direction that is orthogonal to the conveying direction, and Calculating a skew direction, a skew amount, and a sheet interval of each sheet material from the detected conveyance state of the sheet material; and calculating the skew direction, skew of the sheet material. A driving step of driving the respective driving means in parallel based on the amount and the sheet interval of each sheet material. 9. A detecting step of detecting a conveying state of the sheet material sequentially conveyed by a plurality of driving units independently rotating and driving on both sides on the same straight line in a width direction orthogonal to the conveying direction of the sheet material; A determining step of determining the skew direction of the sheet material based on the detected conveyance state of the sheet material; and any one of the driving units for performing the skew correction based on the determined skew direction of the sheet material. A selecting step of selecting; a calculating step of calculating a skew amount of the sheet material with respect to the selected driving unit from a detected conveyance state of the sheet material; and the selecting based on the calculated skew amount. A driving step of performing the corrected driving for the driving unit and the normal driving for the other driving units in parallel.