JP4581303B2 - Sheet transport device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet conveying apparatus that conveys a sheet by a conveying member driven by an actuator, and more particularly to a sheet conveying apparatus that can reliably separate and convey a single sheet from stacked sheets.
[0002]
[Prior art]
Various recording apparatuses have been proposed that employ a recording method in which sheet-like recording paper is sequentially conveyed and recording is performed sequentially on the recording paper while the recording paper is sequentially moved to a recording position where the recording head performs recording. Yes. There have been proposed various reading apparatuses that employ a system in which sheet-like originals are sequentially conveyed and the original information is read while passing the original to a reading position on a fixed original reading sensor. In these recording apparatuses or reading apparatuses, a sheet conveying apparatus that conveys a sheet-like recording sheet to a recording position or a sheet conveying apparatus that conveys a sheet-like document to a reading position is attached by a conveying member. Yes. As one method of such a sheet conveying apparatus, a separation method called a bank separation method is known. In this method, the sheet is separated using a separation member in which minute irregularities are formed in a portion that contacts the leading edge of the sheet or a separation member having a high friction coefficient.
[0003]
[Problems to be solved by the invention]
However, in the separation method in which the uppermost sheet is separated from the stacked sheets by moving the uppermost sheet to the downstream side in the conveying direction by the paper feed roller provided at the tip of the swinging arm member, the sheet is moved. The direction and the direction of action of gravity are close. For this reason, when the leading edge of the sheet enters the valleys of the minute unevenness of the separation member and is difficult to come off, the sheet advances at a stroke or is detached when the leading edge of the sheet is removed. There is a possibility that inconvenience that proper conveyance control cannot be performed due to the paper feed roller floating due to the impact.
[0004]
An object of the present invention is to provide a sheet conveying apparatus capable of appropriately controlling sheet conveyance by reliably separating and conveying a single sheet from stacked sheets.
[0005]
[Means for Solving the Problems]
Sheet conveying apparatus of the present invention includes a sheet holding means for holding the stacked sheets, is driven by an actuator, and a conveying means for conveying the sheet held by said sheet holding means, the transport direction downstream side of the laminated sheet A sheet separating unit that has a surface that holds the leading end and separates the plurality of sheets by contacting the leading end of the sheet that is conveyed by the conveying unit on the downstream side in the conveying direction; and a first driving period In this case, the conveying means is driven to convey the leading edge on the downstream side in the conveyance direction of the sheet to a position where the leading edge on the downstream side in the conveyance direction of the sheet is disengaged from the sheet separating means , and after the first driving period, the conveying means is stopped, thereafter, Preparations and control means for driving the actuator so as to drive the conveying means again at a second drive period, the And wherein the Rukoto. In addition, on the surface of the sheet separating means, fine irregularities or one having a high friction coefficient may be arranged.
[0006]
According to this sheet conveying apparatus, the conveying member is driven in the first driving period, the conveying member is stopped after the first driving period, and then the conveying member is driven again in the second driving period. Before the two driving periods are started, one sheet can be reliably separated and conveyed, and the sheet conveyance can be appropriately controlled.
[0007]
The driving speed in the first driving period may be different from the driving speed in the second driving period.
[0008]
In this case, the sheet can be more reliably separated in the first driving period by setting the driving speed in the first driving period to be lower than the driving speed in the second driving period. In addition, since the driving speed in the second driving period is high, it does not take much time for separation and conveyance.
[0009]
The conveying member may be continuously stopped for a predetermined period between the first driving period and the second driving period.
[0010]
In this case, since the conveying member is stopped for a predetermined time between the first driving period and the second driving period, the sheet can be further separated and conveyed more stably. For this reason, even a sheet that is difficult to separate can be reliably separated and conveyed.
[0011]
A detection unit that is provided on the downstream side of the conveying member and detects the sheet may be provided, and the control unit may determine that the operation is abnormal when the detection unit detects the sheet at a predetermined timing.
[0012]
In this case, when accurate separation / conveyance of the sheet fails, processing different from the normal case can be executed. For example, when the sheet is ejected by the ejecting unit, printing may not be performed, or processing that does not perform reading of the document may be performed.
[0013]
You may provide the sheet separation means which performs sheet separation by a bank separation system.
[0014]
However, the present invention is not limited to the bank separation method, and can be applied to other methods such as a nail separation method.
[0015]
If it is determined that the operation is abnormal, the control unit may discharge the sheet without executing printing on the sheet. In this case, it is possible to prevent printing from being performed at an incorrect position on the sheet, and it is possible to prevent useless use of the sheet. Further, there is no need for the user to remove the sheet that has failed to be conveyed.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
-First embodiment-
Hereinafter, a first embodiment of the sheet conveying apparatus of the present invention will be described with reference to FIGS.
[0017]
FIG. 1A is a side view of the sheet conveying apparatus of the present embodiment, FIG. 1B is a control block diagram of the sheet conveying apparatus of the present embodiment, and FIGS. 2 and 3 are diagrams illustrating the operation of the sheet separating roller. is there. As shown in FIGS. 1A and 1B, the sheet conveying apparatus of the present embodiment includes a sheet separating roller unit 1 that feeds out sheets 100, and a sheet storage plate that holds the stacked sheets 100 in an inclined state. 2, a sheet separating member 3 having a bank portion 31 having minute unevenness on the surface (upper surface), a registration sensor 4 for detecting the leading edge of the sheet 100, and a PF that conveys the sheet 100 along the conveyance path 6. And a roller 5.
[0018]
As shown in FIGS. 1 to 3, the sheet separation roller unit 1 includes an arm unit 1 a, a sun gear TG, a planetary gear YG that meshes with the sun gear TG, and a driven gear PG that is attached so as to mesh with the planetary gear YG. And a sheet separation roller KR1 that meshes with the driven gear PG. Further, the sun gear TG is coaxially connected to a drive shaft (not shown) of the sheet separating roller unit 1, and the sheet separating roller unit 1 is driven by a biasing member 60 formed of a wire spring shown in FIGS. 2 and 3. It is urged toward the seat 100 around (coaxial with the sun gear TG).
[0019]
The driving force of the stepping motor 11 is transmitted to the PF roller 5 and the sun gear TG of the sheet separating roller unit 1 through a driving system (not shown).
[0020]
As shown in FIG. 2, when the stepping motor 11 is reversely rotated, the sun gear TG rotates counterclockwise and the planetary gear YG meshes with the driven gear PG. Therefore, the sheet separation roller KR1 rotates in the clockwise direction, and the sheet 100 on the uppermost surface side of the stacked sheets is sent out toward the sheet separation member 3. At this time, the PF roller 5 rotates in the clockwise direction.
[0021]
On the other hand, as shown in FIG. 3, when the stepping motor 11 rotates forward, the sun gear TG rotates in the clockwise direction, and the planetary gear YG separates from the driven gear PG. For this reason, the driving force of the stepping motor 11 is not transmitted to the sheet separation roller KR1, and the sheet separation roller KR1 is in a free state. At this time, the PF roller 5 rotates counterclockwise.
[0022]
As shown in FIG. 1A, a regulation spring 22 is attached to the holder of the sheet separation roller unit 1. The regulating spring 22 abuts against the internal member 23 when the sheet 100 is set in a full state on the sheet storage plate, and serves to regulate the position of the sheet separating roller KR1. Thereby, even when the sheet 100 is set in a full state, the leading end of the sheet on the uppermost surface is configured to surely cover the bank portion 31 of the sheet separating member 3.
[0023]
As shown in FIG. 1A, the holder of the sheet separation roller unit 1 is provided with an operation protrusion 1 c that protrudes slightly above the case cover 50 that covers the upper part of the sheet separation roller 1. . The operation projection 1c is a state where the planetary gear YG is engaged with the driven gear PG as shown in FIG. 2 when a jam or the like occurs during the paper feeding operation by the reverse driving of the stepping motor 11. Even when the sheet is stopped, the sheet 100 that is in contact with the sheet separation roller KR1 is used to be able to be extracted upward. That is, the operation protrusion 1c is placed on the rear side of the apparatus against the action of the urging member 60 that urges the sheet separating roller portion 1 so that the sheet separating roller KR1 always contacts the sheet 100 (see FIG. 1, the sheet separating roller KR1 is separated from the sheet 100. Therefore, the free sheet 100 can be freely extracted upward without being interrupted by the sheet separation roller KR1.
[0024]
In addition, the operation projection 1c is operated when the rear side unit composed of the sheet storage plate 2, the bank portion 3 and the like is removed from the front side unit (apparatus main body) having the sheet separation roller portion 1 and its driving mechanism. The projection 1c abuts against the rear end edge of the case cover 50, so that the sheet separating roller 1 is prevented from jumping further to the rear side (right side in FIG. 1). Thereby, when reattaching the rear unit, or when newly assembling, the sheet separating roller unit 1 can be reliably placed at a predetermined position against the action of the biasing member 60. For example, there is no fear that the rear unit is attached by mistake while the sheet separating roller part 1 is raised to the rear side by the action of the urging member 60, and the sheet separation roller part 1 is attached while being pressed by hand so as not to be raised. Troublesome work is also unnecessary.
[0025]
As shown in FIG. 1B, the stepping motor 11 and the registration sensor 4 are connected to a control device 12, and the control device 12 is connected to a personal computer 15 via an interface 14. The stepping motor 11 is controlled by the control device 12. The detection signal of the registration sensor 4 is input to the control device 12. Further, the paper feeding / printing process is executed based on the control by the control device 12 in accordance with a command from the personal computer 15.
[0026]
Next, the operation of the sheet conveying apparatus of the present embodiment will be described with reference to FIGS. FIG. 4 is a flowchart showing the paper feeding / printing process, FIG. 5 is a diagram showing the driving speed of the stepping motor in the first paper feeding mode, and FIG. 6 is a diagram showing the driving speed of the stepping motor in the second paper feeding mode.
[0027]
In step S11 of FIG. 4, after waiting for a print command from the personal computer 15, the process proceeds to step S12. In step S12, based on the signal from the personal computer 15, it is determined whether or not an envelope or a card has been selected as a printing target. If the determination is negative, that is, if plain paper is selected, the process proceeds to step S13. If the determination is affirmed, the process proceeds to step S14. In step S13, paper feed / printing in the first paper feed mode is executed, and the process returns to step S11.
[0028]
As shown in FIG. 5, in the first paper feeding mode, after the first driving period in which the stepping motor 11 is reversely rotated at a low speed (driven to the position where the leading edge of the sheet is removed from the bank portion 31), the stepping is instantaneously performed. The motor 11 is stopped, and the stepping motor 11 is reversed at a higher speed in the second drive period provided thereafter. Thus, in the first paper feed mode, the sheet separation roller KR1 is stopped by stopping the stepping motor 11 between the first drive period and the second drive period. By executing such an operation, the leading edge of the uppermost sheet can be reliably removed from the bank portion 31 in the first driving period.
[0029]
In other words, by driving the stepping motor 11 at a low speed until the leading edge of the paper is removed from the bank 31, separation can be reliably performed. In particular, the leading edge of the paper is not easily detached from the bank 31 and has come off. Even when the sheet separation roller KR1 is lifted from the sheet due to momentum (vibration), the sheet is stopped once at a position deviated from the bank, and the sheet separation roller KR1 is normal during that time. You can return to the correct state. Therefore, in the subsequent second driving period, since the leading edge of the sheet is already out of the bank portion, the sheet can be conveyed at a higher speed than in the first driving period, and the sheet can be conveyed by the sheet separation roller KR1. Along with the rotation, it can be conveyed quickly and reliably. When the leading edge of the sheet is detected by the registration sensor 4 in the second driving period, the sheet is nipped by the PF roller 5 by continuing the reverse rotation of the stepping motor 1 and conveying the sheet by a predetermined conveyance amount. Resist. Thereafter, the stepping motor 1 is rotated forward to transport the paper along the transport path 6.
[0030]
For example, the sheet conveying speed in the first driving period can be set to 2 IPS (inch per second), and the sheet conveying speed in the second driving period can be set to 4 IPS (inch per second).
[0031]
On the other hand, in step S14, paper feeding / printing in the second paper feeding mode is executed, and the process returns to step S11.
[0032]
As shown in FIG. 6, in the second paper feed mode, a stop period in which the stepping motor 11 is stopped for a predetermined time is provided after the first driving period in which the stepping motor 11 is reversely rotated at a low speed. In the second drive period provided thereafter, the stepping motor is reversed at a higher speed. As described above, in the second paper feeding mode, the sheet separation roller KR1 is stopped for a predetermined time by stopping the stepping motor 11 for a predetermined time between the first driving period and the second driving period. By executing such an operation, the leading edge of the uppermost sheet can be reliably removed from the bank portion 31 even in the case of a sheet such as an envelope that is likely to cause a problem in conveyance.
[0033]
For example, the sheet conveyance speed in the first drive period can be set to 1 IPS (inch per second), and the sheet conveyance speed in the second drive period can be set to 4 IPS (inch per second). Further, the stop period can be set to 300 ms (0.3 seconds).
[0034]
As described above, in this embodiment, the sheet separation roller KR1 is stopped between the first driving period and the second driving period, so that the leading edge of the sheet completely enters the valley bottom of the bank portion 31. Even in the case of slackening, the leading edge of the sheet can be reliably removed from the bank portion 31 before the second driving period is started. On the other hand, when the sheet is transported at one time without stopping the sheet separation roller KB1, the leading edge of the sheet is not easily detached from the bank portion 31, and when the sheet is detached, the leading edge of the sheet may travel along the transportation path at once. is there. In such a case, the sheet separation roller KR1 is lifted by the momentum of the sheet, and the sheet cannot be conveyed. In addition, if the position detected by the registration sensor 4 is exceeded at a stretch with the momentum of being removed from the bank portion 31, the exact position of the sheet cannot be detected. Accordingly, there arises a problem that it becomes impossible to control the amount of paper transport. The present invention solves such a problem. By driving the sheet at a low speed until the leading edge of the sheet comes off the bank 31, the leading edge of the sheet is reliably and stably moved from the bank. In addition to being able to remove the sheet, it is possible to prevent as much as possible that the sheet that has largely jumped out with the momentum when it is removed from the bank 31 erroneously operates the registration sensor 4. Even if the sheet separation roller KR1 is lifted from the paper by the momentum (vibration) when it is removed from the bank, the paper stops once at the position where it is removed from the bank, The sheet separation roller KR1 can return to the normal state. In particular, when transporting relatively thick paper such as envelopes and cards, the impact when it comes off the bank is greater. In this case, however, the paper stays at a position off the bank for a predetermined time. Since it is stopped, the sheet separation roller KR1 can return to a normal state during that time. Therefore, even in the case of transporting relatively thick paper such as envelopes and cards as well as plain paper, in the subsequent second driving period, the sheet separation roller KR1 is reliably rotated. Can be conveyed. In addition, during the second driving period, the leading edge of the paper is already out of the bank, so that no large resistance is received during the conveyance. For this reason, in the second driving period, the sheet can be conveyed at a higher speed than in the first driving period, and the sheet can be conveyed promptly and reliably with the rotation of the sheet separation roller KR1. Thus, a series of paper feeding operations can be performed in as short a time as possible.
[0035]
The first paper feed mode and the second paper feed mode may be switched manually.
[0036]
-Second Embodiment-
Hereinafter, a second embodiment of the sheet conveying apparatus of the present invention will be described with reference to FIGS. In the second embodiment, a discharge operation when an abnormality is detected is added to the transport / print processing in the first paper feed mode of the first embodiment. FIG. 7 is a flowchart showing processing in the second embodiment, and FIG. 8 is a timing chart showing operation.
[0037]
Hereinafter, the process illustrated in FIG. 7 will be described.
[0038]
In step S21 of FIG. 7, pre-feeding is started, and in subsequent step S22, pre-feeding is terminated at a predetermined timing. This pre-feeding corresponds to the first drive period in the first feed mode.
[0039]
Next, in step S23, it is determined whether or not the registration sensor 4 is turned on at the end of pre-feeding. If this determination is affirmed, it is determined that the operation is abnormal, and the process proceeds to step S29. If this determination is negative, it is determined that the operation is normal, and the process proceeds to step S24.
[0040]
In step S24, actual paper feeding is started. This main paper feed corresponds to the second drive period in the first paper feed mode.
[0041]
Next, in step S26, it is determined whether or not the registration sensor 4 is turned on before the time T during actual paper feeding, that is, before switching to through-down. If this determination is affirmed, it is determined that the operation is normal, and the process proceeds to step S27. If this determination is negative and it is determined that the through-down is on (step S31: YES), it is determined that the operation is abnormal, and the process proceeds to step S29.
[0042]
If it is not turned on during the through-down (step S31: NO), it is determined that “paper feeding error (pickup error)” and the process returns to step S21.
[0043]
The process related to “N” shown in the flowchart of FIG. 7 is performed when the registration sensor 4 is not turned on even if a series of operations determined as “paper feeding error (pickup error)” is repeated three times. If the paper feeding is not normally performed even after the paper feeding retry operation is repeated three times, it is judged as “paper feeding error” or “no paper”, an error message is displayed, and the apparatus is stopped (step S32).
[0044]
In step S26, if the registration sensor 4 is turned on by the time during the main sheet feeding, that is, if it is determined to be normal operation, in step S27, the sheet is conveyed to a position nipped by the PF roller 5, and then In step S28, predetermined print processing and paper discharge processing are executed, and a series of processing ends. In this case, predetermined printing is performed on the paper.
[0045]
On the other hand, if it is determined in step S23 or step S26 that the operation is abnormal, the sheet is conveyed to a position where it is nipped by the PF roller 5 in step S29. Next, in step S30, the paper discharge process is executed without executing the print process, and the series of processes ends. In this case, since the conveyance operation is abnormal and normal printing cannot be expected, the sheet is discharged without printing.
[0046]
According to the above processing, as shown in FIG. 8, even if the registration sensor 4 is temporarily turned on before the end of the pre-feed due to vibration or the like, it is not determined that the operation is abnormal ((1) in FIG. 8). If the registration sensor 4 is on at the end of pre-feeding, it is determined that the operation is abnormal ((2) in FIG. 8). In addition, when the registration sensor 4 is turned on during the through-feeding of the main paper feed, it is determined that the operation is abnormal ((3) in FIG. 8), and only when the registration sensor 4 is turned on before the start of the down-feeding of the main paper feed. The normal operation is determined ((4) in FIG. 8).
[0047]
As described above, in the second embodiment, when the conveyance operation is determined to be abnormal based on the detection timing of the registration sensor, the sheet is discharged without executing the printing process. It is possible to reliably prevent printing from being executed.
[0048]
In the second embodiment, printing is not performed when it is determined that the operation is abnormal. However, the determination of the abnormal operation may be reflected in some processing. For example, printing may be executed even when the operation is determined to be abnormal.
[0049]
In the above embodiment, an example in which the sheet conveying apparatus of the present invention is applied to a printing apparatus has been described. However, the present invention is not limited to application to a printing apparatus. For example, the present invention can be applied to an apparatus for reading a document.
[0050]
【The invention's effect】
According to the sheet conveying apparatus of the present invention, the conveying member is driven in the first driving period, the conveying member is stopped after the first driving period, and then the conveying member is driven again in the second driving period. Before the second driving period is started, one sheet can be reliably separated and conveyed, and the conveyance of the sheet can be controlled appropriately.
[Brief description of the drawings]
1A and 1B are diagrams illustrating a sheet conveying apparatus according to a first embodiment, in which FIG. 1A is a side view and FIG. 1B is a control block diagram;
FIG. 2 is a diagram illustrating an operation of a sheet separation roller.
FIG. 3 is a diagram illustrating an operation of a sheet separation roller.
FIG. 4 is a flowchart illustrating paper feeding / printing processing.
FIG. 5 is a diagram illustrating a driving speed of a stepping motor in a first paper feed mode.
FIG. 6 is a diagram illustrating a driving speed of a stepping motor in a second paper feed mode.
FIG. 7 is a flowchart showing processing in the second embodiment.
FIG. 8 is a timing chart showing the operation.
[Explanation of symbols]
11 Stepping motor (actuator)
12 Control device (control means)
100 Sheet KR Sheet separation roller (conveying member)

Claims (6)

Sheet holding means for holding the laminated sheets;
Conveying means driven by an actuator and conveying the sheet held by the sheet holding means ;
A sheet having a surface that holds a leading end on the downstream side in the conveyance direction of the stacked sheets, and separating the plurality of sheets by contacting the front end on the downstream side in the conveyance direction of the sheet conveyed by the conveyance unit. Separating means;
In the first driving period, the conveying unit is driven so as to convey the leading end on the downstream side in the sheet conveying direction to a position where the leading end on the downstream side in the conveying direction of the sheet is disengaged from the sheet separating unit . Control means for driving the actuator so as to stop the conveying means after the driving period and then drive the conveying means again in the second driving period ;
A sheet conveying apparatus comprising: 2. The sheet conveying apparatus according to claim 1, wherein the surface of the sheet separating unit is arranged with minute irregularities or a high friction coefficient. 3. The sheet conveying apparatus according to claim 1, wherein the control unit drives the actuator such that a driving speed in the first driving period is different from a driving speed in the second driving period. . The said control means drives the said actuator which stops the said conveyance means continuously for a predetermined period between the said 1st drive period and the said 2nd drive period, The any one of Claims 1-3 characterized by the above-mentioned. The sheet conveying apparatus according to claim 1. Provided on the downstream side of the conveying means, comprising a detecting means for detecting the sheet;
Wherein, when said detected the sheet at a predetermined timing by detecting means, the sheet conveying device according to any one of claims 1 to 4, wherein determining that abnormal operation. The sheet conveying apparatus according to claim 5 , wherein the control unit discharges the sheet without executing printing on the sheet when it is determined as an abnormal operation.

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