JP4329504B2 - Document reader - Google Patents

Description

  The present invention relates to a document reading device provided in a copying machine, a facsimile machine, a scanner, a multi-function device thereof, and the like, and particularly when discharging a document stocked on a document table without reading it. The present invention relates to a document reading apparatus that corrects skew of a document.

Conventionally, as this type of document reading device, for example, configurations described in Patent Document 1, Patent Document 2, and Patent Document 3 have been proposed. That is, in the conventional apparatus described in Patent Document 1, a hook is provided in the upstream portion of the document transport path, and the skew of the document is corrected by bringing the leading end of the document into contact with the hook. . In the conventional apparatus described in Patent Document 2, a conveyance member for guiding the conveyance of the document is provided on the upstream side of the discharged document tray located at the most downstream portion of the conveyance path, and the conveyance member is cut obliquely. A guide portion (the paper discharge end portion in Patent Document 2) is provided. Then, the corners of the document are guided by the guide unit, whereby the skew of the document is corrected, and the document is discharged to the discharge tray in a stacked state. Further, in the conventional apparatus described in Patent Document 3, the document is circulated and conveyed to read both the front and back sides of the document, and the discharge roller moves in the axial direction at the most downstream position of the document conveyance path. The skew of the outgoing document is corrected, and the refeed (return) document placed on the document placement unit is aligned.
Japanese Patent Laid-Open No. 11-49395 JP-A-10-330007 JP-A-6-183651

  However, in the conventional configuration of Patent Document 1, since the front ends of all documents to be conveyed are brought into contact with the hooks protruding into the conveyance path, the conveyance speed cannot be increased. That is, when an original is discharged, it is not necessary to read an image. Therefore, it is desirable to increase the discharge speed as much as possible. However, the conventional configuration of Patent Document 1 is not suitable for such a request. is there. In addition, the conventional configuration of Patent Document 1 is inconvenient because all the originals always come into contact with the hooks, and an extra operation is involved in conveyance when skew correction is not required. In addition, since the conventional configuration of Patent Document 1 requires a special configuration in which a hook is provided, the device and components that do not require skew correction cannot be used in common.

  The conventional configuration of Patent Document 2 also has substantially the same problem as Patent Document 1. That is, since the corners of all the documents to be conveyed are guided by the guide unit, the conveyance speed cannot be increased, and a special configuration of providing the guide unit is necessary, so that the parts are shared. Can not do.

  Further, in the conventional configurations of Patent Document 2 and Patent Document 3, since skew correction is performed at the most downstream portion of the transport path, it is not possible to correct the skew of the document carried into the transport path. There was a problem that the paper jam inside could not be prevented. Moreover, the configuration of Patent Document 3 requires a configuration of an actuator or the like for moving the paper discharge roller in the axial direction, and the configuration is complicated.

  The present invention has been made paying attention to the problems existing in the prior art as described above. An object of the present invention is to provide a document reading apparatus that can increase the document discharge speed, prevent paper jams in the conveyance path, and can use parts in common without requiring a special configuration.

In order to achieve the above object, the invention described in claim 1 is provided in an upstream side of the reading unit in a document reading apparatus in which an image of a document conveyed in a conveyance path is read by a reading unit, A skew correction means comprising a pair of correction rollers, a feed roller positioned upstream of the correction roller, and a stop means for temporarily stopping rotation of the correction roller during document conveyance by the feed roller, and an image Control means for controlling the skew correction means to be operated during document discharge conveyance without reading, skew correction mode for enabling the operation of the skew correction means, and correction invalid mode for invalidation Sorted count and selection means for selecting, jams number in the conveying path, the accumulated number of paper jam becomes a constant value, the skew correction by the skew correcting means Characterized by comprising a setting means for setting the over-de.

According to a second aspect of the present invention, in the first aspect of the present invention, the reading unit includes a first reading unit for reading an image on the front side of the document and a second reading for reading an image on the back side. And a section.

According to a third aspect of the present invention, in the second aspect of the present invention, the first and second reading units are juxtaposed along the conveyance direction of the conveyance path, and images on both sides of the document are obtained in one pass. It is characterized by reading.

  According to the present invention, since a member such as a hook does not protrude in the conveyance path, the document discharge speed can be increased, paper skewing can be prevented, and paper jam in the conveyance path can be prevented. Moreover, there is an effect that parts can be used in common without any special configuration.

(First embodiment)
Hereinafter, a first embodiment in which a document reading apparatus according to the present invention is embodied in a multifunction machine will be described with reference to FIGS.

  As shown in FIG. 2, a document feeding unit 11, a stationary document placing unit 12, and a document reading mechanism unit 13 are installed on the upper part of the multifunction machine 10 as a document reading device. The document feeding unit 11 constitutes a transport path 50 for transporting a plurality of documents continuously when the images on both the front and back sides are read or discharged. When reading a still image from a document, the document is placed on the document placement unit 12. In addition, a well-known recording paper supply unit, a recording unit, and a recording paper discharge unit (not shown) are installed below the multifunction machine 10.

  As shown in FIGS. 1 and 2, on the document feeder 11, a document table 14 for placing a plurality of documents before reading in a stacked state, and a document after reading are mounted in a stacked state. A document discharge table 15 is provided. A section between the document feed port 51 of the document table 14 and the document discharge port 52 of the document discharge table 15 is a conveyance path 50 for continuously conveying the plurality of documents.

  A shutter 16 that can be opened and closed is disposed in the vicinity of the document feed port of the document table 14 so as to abut the front ends of a plurality of documents placed on the document table 14. On the upstream side of the shutter 16, a pickup roller 17 is disposed to abut on the uppermost document among a plurality of documents on the document table 14 and send the document to the conveyance path 50 side. . On the downstream side of the shutter 16, there are a separation roller 18 and a separation pad 18 a as a feeding roller for separating the originals sent through the shutter 16 by the pickup roller 17 and feeding them one by one into the conveyance path 50. It is arranged.

  As shown in FIGS. 1 and 2, on the downstream side of the separation roller 18 of the document feeding unit 11, a registration roller 19, a first feeding roller 20, a second feeding roller 21, a surface reading roller 22, A third feeding roller 23, a back surface reading roller 24, and a fourth feeding roller 25 are disposed along the conveyance path 50 in the order of document conveyance. Among these rollers 19 to 25, the registration rollers 19, the first feeding roller 20, the second feeding roller 21, the third feeding roller 23, and the fourth feeding roller 25 include idle rollers 19 a, 20 a, 21a, 23a, and 25a are arranged in contact with each other. In this embodiment, a correction roller that forms a pair is constituted by a registration roller 19 and an idle roller 19a.

  Each of the rollers 17 to 25 from the pickup roller 17 to the fourth feeding roller 25 is operatively connected to a step motor 26 as one drive motor shown in FIG. Further, among these rollers 17 to 25, the electromagnetic clutch 27 shown in FIG. 3 is provided between the pickup roller 17 and separation roller 18 and the step motor 26 and between the registration roller 19 and the step motor 26. 28 and 28, respectively, and the operation connection between the rollers 17-19 and the step motor 26 is cut off as necessary. Further, a contact type image sensor 29 as a reading unit having an image pickup element is disposed at a position corresponding to the back surface reading roller 24. The clutch 28 constitutes a stop means for temporarily stopping the rotation of the correction roller. Further, the skew feeding correcting means is constituted by the separation roller 18, the registration roller 19, the idle roller 19a and the clutch 28.

  As shown in FIG. 1, the document table 14 of the document feeder 11 detects the document size by detecting the size in the sub-scanning direction based on the width of the document placed on the document table 14. A document size detection sensor DLS is provided. Between the pickup roller 17 and the shutter 16, a document presence / absence detection sensor DS1 for detecting the presence / absence of a document in contact with the shutter 16 is provided. A first document position detection sensor DSS for detecting the position of the document being conveyed is provided between the separation roller 18 and the registration roller 19 near the separation roller 18.

  Further, a registration sensor DRS for detecting that the front end of the document is in contact with the registration roller 19 is provided in the vicinity of the registration roller 19. A second document position detection sensor DS2 for detecting the position of the document is provided between the second feed roller 21 and the third feed roller 23 at a position near the third feed roller 23. A third document position detection sensor DS3 for detecting the position of the document is provided between the third feeding roller 23 and the back surface reading roller 24.

  As shown in FIG. 2, the document placement section 12 is provided with a transparent document placement plate 30 for placing a document on the upper surface, and on the document placement plate 30 so as to be openable and closable. A presser lid 31 is provided. The document table 14 and the document discharge table 15 of the document feeding unit 11 are disposed on the presser lid 31 of the document placing unit 12.

  As shown in FIGS. 1 and 2, the document reading mechanism 13 includes a translucent plate 32, a light source 33, a first mirror 34, a second mirror 35, a third mirror 36, a condenser lens 37, and the image sensor. 29 is equipped with an image pickup device (CCD) 38 as a reading means arranged in parallel. The translucent plate 32 is disposed so as to face the surface reading roller 22 of the document feeder 11. The light source 33 irradiates the original passing through the translucent plate 32 or the original placed on the original placement plate 30 with light. The first to third mirrors 34 to 36 change the optical path of the reflected light from the document. The condensing lens 37 converges the light from the third mirror 36 on the image sensor 38. The image sensor 38 reads an image of a document based on light incident through the condenser lens 37 and outputs an image signal of the read document.

  The light source 33 and the first mirror 34 are supported on a first carriage 39 that can move in the sub-scanning direction. The second and third mirrors 35 and 36 are supported on a second carriage 40 that is also movable in the sub-scanning direction. The first carriage 39 is moved at twice the moving speed of the second carriage 40 by a known moving mechanism (not shown).

  As a result, during continuous conveyance of a plurality of documents by the document feeder 11, the first and second carriages 39 and 40 are located directly below the translucent plate 32 from the standby position P1 set almost at the center of the movement range. Is moved and arranged at a reading position P2 opposite to the position. Further, when reading a still image on a document placed on the document placement unit 12, both carriages 39 and 40 are positioned so as to face each other directly below the end of the document placement plate 30 on the document feed unit 11 side. It is moved between P3 and a position P4 that is positioned directly opposite the opposite end of the document placing plate 30.

  An automatic document reading device (ADF) is configured by the document feeding unit 11 and the document reading mechanism unit 13 configured as described above, and the first and second carriages 39 and 40 are disposed at the reading position P2. Then, the image on the document passing over the translucent plate 32 is read. Further, the document placing unit 12 and the document reading mechanism unit 13 constitute a flat bed scanner (FBS), and the document is placed on the document placing plate 30 while the carriages 39 and 40 are moved from the position P3 to the position P4. The image on the placed document is read.

Next, the electrical configuration of the multifunction machine 10 configured as described above will be described.
As shown in FIG. 3, the control device 41 constitutes a control means for controlling the operation of the entire multifunction machine 10. The control device 41 includes a storage unit 42 for storing various data such as the operation program of the multifunction peripheral and the size of the document in the sub-scanning direction. The control device 41 has an image memory 71 for storing the read image data. Then, the control device 41, based on the signals input from the sensors DLS, DS1, DSS, DRS, DS2, DS3, and the document reading start button 43, the step motor 26, the separation roller clutch 27, The registration roller clutch 28 and the like are controlled to convey the document on the document table 14 toward the document discharge table 15 for image reading. The control device 41 controls the operations of the contact image sensor 29 and the image sensor 38 for image reading. Further, the control device 41 conveys the document on the document table 14 toward the document ejection table 15 without performing image reading for ejection based on a signal input from the ejection button 62. Further, based on a signal input from the skew correction button 63, the control device 41 causes the skew correction of the document to be described later when the document is discharged.

  Further, the light source 33, the first mirror 34, the second mirror 35, the third mirror 36, the condensing lens 37, the image sensor 38, and the like of the document reading mechanism unit 13 are used to read the image on the front or back surface of the document. One reading unit is configured. Further, the contact image sensor 29 of the document feeding unit 11 constitutes a second reading unit for reading an image on the back surface or the front surface of the document. Here, it is assumed that the first reading unit reads the front side of the document and the second reading unit reads the back side.

  Then, the controller 41 continuously conveys the document by the document feeding unit 11 and performs reading processing of the images on both the front and back sides, and during the reading operation of the preceding document, The image pickup element 38 of the reading unit, the contact image sensor 29, the registration roller clutch 28 of the correction unit, and the like are controlled to perform the skew correction operation. In this case, the control device 41 temporarily stops the registration roller 19 by cutting off the connection of the registration roller clutch 28 during the feeding operation of the document by the separation roller 18, thereby correcting the skew state of the document. It is like that. Further, the control device 41 temporarily stops the registration roller 19 by disconnecting the registration roller clutch 28 during the document discharge operation based on the signals from the discharge button 61 and the skew correction button 63. The document is stopped and the skew state of the document is corrected.

Next, the operation of the MFP 10 configured as described above will be described.
In the multi-function device 10, when the document feeding unit 11 is used to continuously read a plurality of documents while reading the images on both the front and back sides, based on the control of the control device 41. 4, the feeding process shown in the flowchart of FIG. 4 and the skew correction process shown in the flowchart of FIG. 5 are executed. These processes proceed by executing a program in the storage unit 42 under the control of the control device 41.

  In this case, the sending-in process refers to a control process in which the documents placed on the document table 14 are fed one by one into the conveyance path 50. Also, the skew correction process is a control process for temporarily stopping the conveyance of the document that is sent to the conveyance path 50 and waiting, and correcting the skew state. Further, the reading process refers to conveying the document sequentially to the front surface reading position FP and the back surface reading position BP shown in FIG. 1 and reading the images on both the front and back surfaces of the document in one pass by the image sensor 38 and the contact image sensor 29. Refers to control processing.

First, the sending process in FIG. 4 will be described.
In step (hereinafter abbreviated as S) 100, when the start button 43 is pressed, whether or not a document is placed on the document table 14 is determined based on a detection signal from the document presence / absence detection sensor DS1. It is determined (S101). When a document is present, the size of the document in the sub-scanning direction is determined by the detection signal from the document size detection sensor DLS, and the size is stored in the storage unit 42 (S102).

  Thereafter, the step motor 26 is started and the registration roller clutch 28 is switched from the disconnected state to the connected state (S103). Subsequently, the separation roller clutch 27 is switched from the disconnected state to the connected state (S104). As a result, the rotation of the step motor 26 is transmitted to the pickup roller 17, the separation roller 18, the registration roller 19 and the like. 50.

  Subsequently, based on the detection signal from the first document position detection sensor DSS, it is determined whether or not the front end of the document has been sent to a predetermined first transport position on the registration roller 19 side with respect to the separation roller 18 (S105). When the document is sent to the first transport position, measurement of the transport amount of the document from the first transport position is started based on the number of driving steps of the step motor 26 (S106). Further, during the feeding operation of the document by the separation roller 18, a skew correction process of the document shown in the flowchart of FIG. 5 described later is executed with the registration roller 19 (S107).

  Next, after executing the skew correction process, the front end of the document is conveyed from the registration roller 19 to the document reading unit such as the image sensor 29. Then, the transport amount of the document from the first transport position corresponds to the transport amount corresponding to the size of the document stored in the storage unit 42, that is, the transport amount transported to a position where the trailing edge of the document is separated from the separation roller 18. Is determined (S108). When the transport amount of the document reaches a predetermined amount, the separation roller clutch 27 is switched to the disconnected state, and the pickup roller 17 and the separation roller 18 are stopped (S109). As a result, the feeding of the succeeding document is temporarily stopped, and the preceding document is continuously conveyed by the registration roller 19 in this state.

  Thereafter, it is determined whether or not the trailing edge of the document has been transported to the first transport position based on a detection signal from the first document position detection sensor DSS (S110). When the trailing edge of the document is conveyed to a predetermined position, it is determined whether or not a subsequent document exists on the document table 14 based on a detection signal from the document presence / absence detection sensor DS1 (S111). When there is a subsequent document on the document table 14, the process returns to S104, and the processes of S104 to S111 are repeatedly executed. Thus, when a plurality of documents are placed on the document table 14, each document is transported with a predetermined interval between the trailing edge of the preceding document and the leading edge of the succeeding document. It is sent to the route 50 in order. On the other hand, if it is determined in S111 that there is no document on the document table 14, the sending process is terminated.

Next, the skew correction process of the document shown in FIG. 5 will be described.
In the document feeding process, during the operation of the document by the separation roller 18, first, whether or not the document is fed to the second transport position where the front edge of the document contacts the registration roller 19 is detected by a detection signal from the registration sensor DRS. It is determined (S200). When the front end of the document reaches the second transport position, the registration roller clutch 28 is switched from the connected state to the disconnected state, the registration roller 19 is stopped, and the front end of the document is based on the number of driving steps of the step motor 26. Measurement of the conveyance amount on the rear end side in a state where the side is stopped is started (S201).

  As a result, the conveyance of the front end side of the document by the registration roller 19 is temporarily stopped, and only the conveyance of the rear end side of the document by the separation roller 18 is continued. For this reason, the document is placed in a standby state, the front edge of the document is pressed against the registration roller 19, and the skew state of the document is corrected. In this case, if there is a document preceding the waiting document, the reading process for the preceding document is performed simultaneously with the skew correction process of the waiting document.

  Subsequently, it is determined whether or not the conveyance amount on the trailing edge side of the document by the separation roller 18 has reached a predetermined conveyance amount necessary for correcting the skew of the document stored in the storage unit 42 (S202). When the document transport amount reaches a predetermined value, the separation roller clutch 27 is switched from the connected state to the disconnected state, and the rotation of the pickup roller 17 and the separation roller 18 is stopped (S203). As a result, the conveying operation on the trailing edge side of the document is stopped, and the skew correction operation of the document is completed.

  Thereafter, it is determined whether or not the standby document that has finished the skew correction operation is the first document among the plurality of documents on the document table 14 (S204). If it is the first document, both the separation roller clutch 27 and the registration roller clutch 28 are switched from the disconnected state to the connected state (S205). Thereby, the pickup roller 17, the separation roller 18, and the registration roller 19 are rotated, and the conveyance of the document in the standby state is resumed.

  On the other hand, if it is determined in S204 that the document in the standby state is not the first document, in the reading process, based on the determination result whether or not the trailing edge of the preceding document has reached the front surface reading position FP, It is determined whether the image reading on the surface of the document has been completed (S206). When the image reading of the preceding document is completed, the process proceeds to S205, where both the clutches 27 and 28 are switched, the rollers 17 to 19 are rotated, and the conveyance of the document in the standby state is resumed.

  As a result, when it is determined that the reading posture of the subsequent document is ready, that is, when the preceding document and the subsequent document have a predetermined front-rear interval in the transport path 50, the process waits in the middle of the transport path 50. The conveyance of the subsequent document is resumed. Here, the front-rear interval between the preceding document and the succeeding document is set to an interval at which the image reading data on the surface of the preceding document can be stored in the image memory 71 before the image reading on the surface of the succeeding document is started. Yes.

  As described above, in the multifunction machine 10 of this embodiment, the document feeding unit 11 reads a plurality of documents one by one into the transport path 50 one by one and reads the images on the front and back surfaces of these documents. In this case, the image reading operation for the preceding document and the skew correction operation for the succeeding document are simultaneously performed.

  Next, the operation when a plurality of documents on the document table 14 are continuously discharged in the multifunction machine 10 will be described with reference to FIG. Also in this discharge operation, various operations proceed by executing the program in the storage unit 42 under the control of the control device 41.

  When it is determined that the discharge button 61 is turned on (S300), processing similar to the processing from S101 onward in FIG. 4 is executed. That is, it is determined whether or not a document is placed on the document table 14 (S301), the size of the document in the sub-scanning direction is determined, and the size is stored in the storage unit 42 (S302). Then, the step motor 26 is activated, the registration roller clutch 28 is switched to the connected state (S303), the separation roller clutch 27 is switched to the connected state (S304), and the first sheet from the document table 14 is switched. The document is sent to the conveyance path 50.

  Subsequently, when it is determined that the front end of the document has been sent to a predetermined first transport position closer to the registration roller 19 than the separation roller 18 (S305), measurement of the transport amount of the document from there is started. (S306).

  Then, it is determined whether or not the skew correction button 63 as the selection means is turned on (S307). If the skew correction button 63 is turned on, a skew correction mode described later shown in FIG. A correction operation is executed (S308). When the skew correction button 63 is not turned on, the skew correction mode is invalidated and the skew correction operation is skipped.

  Next, when it is determined whether or not the transport amount has reached the position where the trailing edge of the document is separated from the separation roller 18 (S309), the separation roller clutch 27 is switched to the disconnected state, and the pickup roller 17 is turned off. Then, the separation roller 18 is stopped (S310), and the subsequent document feeding is temporarily stopped. Thereafter, it is determined whether or not the trailing edge of the document has been transported to the first transport position (S311), and then it is determined whether or not a subsequent document exists on the document table 14 (S312). When there is a subsequent document on the document table 14, the process returns to S304. Thus, when a plurality of documents are placed on the document table 14, each document is transported with a predetermined interval between the trailing edge of the preceding document and the leading edge of the succeeding document. Documents are sequentially sent to the path 50 and discharged. In the case of discharging the original, the original is not read.

Next, the skew correction process of the discharged document will be described with reference to FIG. This skew correction process is the same as the skew correction of FIG. 5 except for steps S204 and S206.
In other words, when the detection signal from the registration sensor DRS reaches the second transport position where the front end of the document contacts the registration roller 19 (S400), the registration roller clutch 28 is switched to the disconnected state, and the registration roller 19 is stopped. At the same time, based on the number of driving steps of the step motor 26, measurement of the conveyance amount on the rear end side in a state where the front end side of the document is stopped is started (S401). As a result, the skew state of the document is corrected as described above.

  Subsequently, when the conveyance amount on the trailing edge side of the document by the separation roller 18 reaches a predetermined conveyance amount necessary for correcting the skew feeding of the document (S402), the separation roller clutch 27 is switched from the connected state to the disconnected state. The rotation of the pickup roller 17 and the separation roller 18 is stopped (S403), the conveying operation on the trailing edge side of the document is stopped, and the skew correction operation of the document is finished.

Thereafter, both the separation roller clutch 27 and the registration roller clutch 28 are switched from the disconnected state to the connected state (S404), and the conveyance for discharging the document is resumed.
As described above, unlike the case of FIG. 4, this discharge process does not read the original, and therefore there is no need for a standby process in which the subsequent original is sent after the preceding original has been read. Therefore, the document can be discharged and conveyed continuously at a short interval. In addition, unlike the conventional configuration described above, the front end of the document is not brought into contact with the hook. Therefore, the document discharge speed can be increased.

  Each time a single original is transported for discharge, the skew state of the original is corrected, so that it is possible to prevent the original from being jammed in the transport path. Moreover, the configuration for this is not provided with a new mechanical configuration such as a hook, so that the configuration is simple and the commonality of components can be achieved.

  In the document discharge process, if the skew correction button 63 is not turned on, the document is sequentially discharged toward the document discharge table 15 without being corrected by the registration rollers 19.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG.
In the second embodiment, setting means is configured for the control device 41 to set the skew correction mode based on the presence or absence of a paper jam in the transport path 50. That is, the passage of a document transported for discharge is detected by any one of the sensors DS1, DSS, DRS, DS2, DS3 (S500), and the downstream side sensor DSS is downstream even if a predetermined time has elapsed. , DRS, DS2, and DS3 do not detect a document (S501), the control device 41 determines that a paper jam has occurred and counts the number of paper jams (S502). If the cumulative number of paper jams is a constant value (S503), the skew correction mode is set (S504).

  When this skew correction mode is set, the skew correction process shown in FIG. 7 is performed on the discharged document when the document is discharged. Therefore, if paper jams are likely to occur due to factors such as the operating status of the device, the environment surrounding the device, such as the humidity surrounding the device, or the paper quality of the document, the skew correction mode is automatically set when the document is ejected. Clogging can be prevented. Conversely, when no paper jam occurs, the skew correction mode is not set and the document can be discharged smoothly. Note that the skew correction mode can be canceled by an operation button (not shown).

  Further, the skew correction mode may be set so that the operator sets the operation button without using the program processing shown in FIG.

FIG. 3 is a longitudinal sectional view illustrating a document feeding unit and a reading unit in the multifunction machine according to the first embodiment. FIG. 3 is a longitudinal sectional view showing an upper part of the multifunction machine. The block diagram which shows an electrical structure. The flowchart of the sending process in reading control. The flowchart of a skew correction process similarly. 6 is a flowchart illustrating document discharge processing. 10 is a flowchart of skew correction processing at the time of document discharge. The flowchart which shows 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Multifunction machine as a document reading device, 18 ... Separation roller constituting feed roller and skew correction means, 19 ... Correction roller, registration roller constituting skew correction means, 19a ... Correction roller, skew correction means Constructing idle roller, 28... Clutch constituting skew correction means and stopping means, 29... Contacting image sensor constituting reading means and second reading unit, 38... Constituting reading means and first reading unit. Image sensor 41... Control device as control means and setting means, 50... Transport path, 63... Skew correction button constituting selection means, P3.

Claims (3)

In a document reading apparatus in which an image of a document conveyed in a conveyance path is read by a reading unit,
A pair of straightening rollers provided on the upstream side of the reading means; a feeding roller located on the upstream side of the straightening roller; and a stopping means for temporarily stopping the rotation of the straightening roller when the original is conveyed by the feeding roller; A skew correction means comprising:
Control means for controlling the skew correction means to be operated at the time of document discharge conveyance without image reading;
Selection means for selecting a skew correction mode for enabling the operation of the skew correction means and a correction invalid mode for invalidating ;
Document reading comprising: setting means for counting the number of paper jams in the conveyance path and setting the skew correction mode by the skew correction means when the cumulative number of paper jams reaches a constant value apparatus. The document reading apparatus according to claim 1, wherein the reading unit includes a first reading unit for reading an image on the front side of the document and a second reading unit for reading an image on the back side. apparatus. The first and the second reading section juxtaposed along the conveying direction of the conveying path, a document according to it has to read the both sides of the image of the document to 請 Motomeko 2 you wherein in one pass Reader .

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