JP2013258641A - Image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a configuration by which a part of multiple-fed documents can be prevented from being ejected irrespective of multiple-feed states.SOLUTION: A multiple-feed detection sensor 8 as multiple-feed detection means detects multiple-feed of documents conveyed in a conveyance path 14. A CPU 80 as control means determines a multiple-feed area where a plurality of documents are overlapped with one another from a detection result of the multiple-feed detection sensor 8, and stops ejection of the documents while the multiple-feed area passes through an ejection roller 12 as ejection means. Accordingly, part of the multiple-fed documents can be prevented from being ejected to a paper ejection tray 13.

Description

  The present invention relates to an image reading apparatus that reads a document conveyed in a conveyance path, and more particularly to control when documents are double-fed in a conveyance path.

  2. Description of the Related Art Conventionally, there has been proposed an image reading apparatus in which an image reading unit serving as a reading unit is arranged on a document conveyance path and an image of a document conveyed by the image reading unit is read. As such an image reading apparatus, for example, a structure in which a plurality of documents placed on a paper feed tray are transported into a transport path by a feed roller and separated from other documents by a separation roller is known. It has been. However, even with such a structure, there may be a case where a plurality of documents are overlapped to be transported into the transport path. Therefore, a structure for detecting such double feed is conventionally known.

  Further, there has been proposed a structure in which the conveyance of a document is stopped when the document is discharged when double feeding is detected (Patent Document 1). As shown in FIG. 16, if the discharge is stopped in a state where the documents 90a and 90b in the double feed state are nipped by the discharge roller 12 as a discharge unit, the documents 90a and 90b in the double feed state are discharged to the discharge tray 13 Can be prevented from being discharged. Since it is necessary to perform the image reading process again for the double-fed document, it is not preferable that the image reading process has already ended normally and mixed with the document placed on the paper discharge tray. Therefore, as shown in FIG. 16, if the documents 90a and 90b in the double-feed state can be stopped by the discharge roller 12, the documents 90a and 90b in the double-feed state have already finished the image reading process normally and are placed on the discharge tray. It is possible to prevent mixing with placed originals.

JP 2008-271537 A

  By the way, when a document is double-fed, there are various cases as a double-fed state. For example, as shown in FIG. 17A, the double feed area 91 where the originals overlap each other is large, or as shown in FIG. 17B, the double feed area 92 is small. Accordingly, when the document discharge is stopped when the double feed is detected without considering such a double feed area, depending on the double feed area, as shown in FIG. There is a possibility that the document 90 a) is discharged to the discharge tray 13. When the original 90a is discharged, the image reading process has already been completed normally and mixed with the original 90c placed on the discharge tray 13.

  In this case, the operator must confirm whether or not the processing has been completed for all the documents placed on the paper discharge tray 13 when the image reading apparatus detects the double feed state and interrupts the processing. Therefore, it was a factor that lowered work efficiency.

  In view of such circumstances, the present invention has been invented to realize a structure capable of preventing a part of a double-fed original from being discharged regardless of a double-fed state.

  The present invention includes a transport unit that transports a document in a transport path, a reading unit that reads a document transported in the transport path, a discharge unit that discharges a document read by the reading unit, and a transport unit in the transport path. And a control for stopping the document discharge operation while the document double feed area obtained from the detection result of the double feed detection unit passes through the discharge unit. And an image reading apparatus comprising the means.

  According to the present invention, since the document discharge is stopped while the document multi-feed area passes through the discharge unit, a part of the document that has been multi-feeded is discharged regardless of the multi-feed state. Can be prevented.

1 is a perspective view schematically showing an image reading apparatus according to a first embodiment of the present invention. FIG. 2 is a perspective view schematically showing a connection state between the image reading apparatus according to the first embodiment and a host computer. 1 is a schematic cross-sectional view of an image reading apparatus according to a first embodiment. FIG. 3 is a control block diagram of the image reading apparatus according to the first embodiment. FIG. 3 is a sequence diagram of reading processing of the host computer according to the first embodiment. FIG. 3 is a sequence diagram of reading processing of the image reading apparatus according to the first embodiment. FIG. 3 is a sequence diagram of double feed processing of the image reading apparatus according to the first embodiment. The schematic diagram which shows a double feeding area | region. The perspective view of the image reading apparatus which concerns on the 2nd Embodiment of this invention. FIG. 5 is a schematic configuration cross-sectional view illustrating a partially omitted image reading apparatus according to a second embodiment. FIG. 9 is a sequence diagram of reading processing of a host computer according to the second embodiment. FIG. 10 is a sequence diagram of double feed processing of the image reading apparatus according to the second embodiment. FIG. 6 is a cross-sectional view illustrating a state where the discharge of a double-fed document is stopped. FIG. 3 is a perspective view of a document with a sticky note. FIG. 10 is a sequence diagram of double feed cancellation processing of the image reading apparatus according to the second embodiment. FIG. 6 is a diagram illustrating a state where the discharge of a document that has been multi-fed by a discharge roller is stopped. (A) The schematic diagram which shows the state where a double feed area is large, and (B) the state where a double feed area is small, respectively. FIG. 5 is a diagram illustrating a state in which a part of a double-fed document has been discharged.

<First Embodiment>
A first embodiment of the present invention will be described with reference to FIGS. First, the overall configuration of the image reading apparatus 1 of the present embodiment will be described with reference to FIGS. 1 to 4.

[Image reading device]
As shown in FIG. 1, the image reading apparatus 1 includes a paper feed tray 4 as a document placement portion for placing a document to be read, a transport path 14 for transporting a document, and a discharge from the transport path 14. A paper discharge tray 13 on which the printed document is placed. The paper feed tray 4 has a document detection sensor 4a that detects whether or not a document is placed on the tray. Such an image reading apparatus 1 is connected to a host computer 2 via a communication cable 3 as shown in FIG.

  In addition, as shown in FIG. 3, the image reading apparatus 1 includes a feeding roller 5, a separation roller 6, a conveying roller 7, a double feed detection sensor 8, a registration sensor 9, image sensors 10, 11 in the conveyance path. A roller 12 is provided.

  Various rollers for transporting documents such as the feeding roller 5 and the transport roller 7 in the transport path 14 correspond to a transport unit. These various rollers such as the feeding roller 5 and the conveying roller 7 are rotationally driven by a motor M as driving means.

  The double feed detection sensor 8 is a double feed detection unit that detects double feed in which a plurality of documents are transported in the transport path 14. The double feed detection sensor 8 is disposed on both sides in the thickness direction of the document conveyed in the conveyance path, and is transmitted from the ultrasonic transmitter 8a as an ultrasonic transmitter for transmitting ultrasonic waves. And an ultrasonic receiver 8b as ultrasonic receiving means for receiving the ultrasonic waves. Then, double feeding is detected from the difference in the signal (ultrasonic wave) received by the ultrasonic receiver 8b between when one original passes and when a plurality of originals are conveyed in a superimposed manner.

  For example, when two originals are overlapped and fed, an air layer exists between the originals. When such an air layer exists, the passing ultrasonic waves are attenuated. For this reason, double feed can be detected from the difference in the signals (ultrasonic waves) received by the ultrasonic receiver 8b. In addition to the configuration using such ultrasonic waves, for example, another conventionally known configuration using light can be used as the sensor for detecting double feeding.

  The registration sensor 9 is a leading edge detection unit that detects the leading edge of the document conveyed in the conveyance path 14. The registration sensor 9 is, for example, a photosensor including a light emitting unit that emits light and a light receiving unit that receives light emitted from the light emitting unit, which are arranged on both sides in the thickness direction of the document conveyed in the conveyance path. Can be used. Then, the light emitted from the light emitting unit is blocked by the conveyed document, thereby detecting that the leading edge of the document has passed.

  The image sensors 10 and 11 are reading units that read a document conveyed in the conveyance path 14. The image sensor 10 is a front image reading unit that reads information on the front side of the document, and the image sensor 11 is a back image reading unit that reads information on the back side of the document. As the image sensors 10 and 11, for example, a sensor such as a CIS (Contact Image Sensor) is used.

  The discharge roller 12 is a discharge unit that discharges the document read by the image sensors 10 and 11. The discharge roller 12 is rotationally driven by a motor M that drives the feeding roller 5 described above. That is, various rollers such as the feeding roller 5 and the conveying roller 7 and the discharge roller 12 are driven to rotate synchronously by one motor M. Note that a plurality of motors may be arranged, and any one of the motors and the other motors may be individually controlled.

  When receiving an image reading instruction from a capture application (not shown) running on the host computer 2, the image reading apparatus 1 separates a plurality of documents placed on the paper feed tray 4 one by one by the separation roller 6. However, the sheet is conveyed into the conveyance path by the feeding roller 5. The document transported into the transport path 14 is further transported by the transport roller 7 and the leading edge is detected by the registration sensor 9. Thereafter, when the original passes through the image sensors 10 and 11 as reading means, information on the front or back of the original is read, and is discharged to a paper discharge tray 13 by a discharge roller 12 as discharge means.

  Here, when the distance on the conveyance path between the registration sensor 9 and the image sensor 10 is L1, and the conveyance speed of the document is v, the leading edge of the document is detected by the registration sensor 9 and the image sensor 10 is detected after time L1 / v. To reach. Accordingly, when the image reading apparatus 1 detects that the leading edge of the document has passed by the registration sensor 9, the image reading apparatus 1 measures time using a timer (not shown). Then, after L1 / v has elapsed from the time when the leading edge of the document has passed through the registration sensor 9, the image sensor 10 reads the front image (information) of the document.

  Similarly, if the distance between the registration sensor 9 and the image sensor 11 on the conveyance path is L2 and the conveyance speed of the document is v, the leading edge of the document is detected by the registration sensor 9 and the image sensor 11 is detected after a time L2 / v. To reach. Accordingly, when the image reading apparatus 1 detects that the leading edge of the document has passed by the registration sensor 9, the image reading apparatus 1 measures time using a timer (not shown). Then, after L2 / v elapses from the time when the leading edge of the document passes through the registration sensor 9, the image sensor 11 reads the back image (information) of the document.

  After reading the front image and the back image, the image reading apparatus 1 transfers the image data to the host computer 2 via the communication cable 3 and discharges the document to the discharge tray 13.

  Such an image reading apparatus 1 is controlled by a CPU 80 as a control unit. As shown in FIG. 4, the CPU 80 controls the feeding unit 81, the conveying unit 82, the double feed detecting unit 83, and the image reading unit 84. The feeding unit 81 is a feeding roller 5 for feeding a document placed on the above-described sheet feeding tray 4 to the conveyance path 14. The conveyance unit 82 is a roller such as a conveyance roller 7 that conveys a document on the conveyance path 14 described above. The double feed detection means 83 is the double feed detection sensor 8 described above. The image reading unit 84 is the image sensors 10 and 11 described above. Such a CPU 80 receives an instruction from the host computer 2 connected via the communication cable 3 or transfers the state of the image reading apparatus 1 to the host computer 2 through the I / F 85.

[Image reading sequence]
Next, an image reading sequence of the image reading apparatus 1 will be described. First, the sequence of the host computer 2 will be described with reference to FIG. In S1000, the host computer 2 that has started the image reading start process in response to the operator's instruction issues a reading instruction to the image reading apparatus 1 in S1001. In step S1002, the host computer 2 receives the image read by the image reading apparatus 1 via the I / F 85, executes an appropriate process, and ends the process in step S1003.

  Next, the sequence of the image reading apparatus 1 instructed to read in S1001 of FIG. 5 will be described with reference to FIG. The CPU 80 of the image reading apparatus 1 instructed to read from the host computer 2 starts reading processing in S2000. In step S2001, the CPU 80 detects whether or not a document is placed on the paper feed tray 4 by the document detection sensor 4a. If no document is placed, the CPU 80 ends the process in S2007.

  On the other hand, in S2001, the CPU 80 that has detected that an original is placed on the paper feed tray 4 is separated by the feeding roller 5 while being separated one by one so that the separation roller 6 is not double-fed in S2002. The document is fed downstream in the conveyance direction. The CPU 80 that has fed the document to the conveyance path 14 performs image reading processing in S2003.

  In step S2004, the CPU 80 that has started the image reading process uses the double feed detection sensor 8 to detect whether or not the document is being conveyed in a double-feed state. If the CPU 80 recognizes that the original is not conveyed in the double feed state in S2004, it monitors whether the original is discharged to the paper discharge tray 13 in S2005. Whether or not the document has been discharged to the discharge tray 13 is determined by, for example, arranging a document detection sensor for detecting the document such as a photo sensor in the vicinity of the discharge roller 12 so that the trailing edge of the document is within a predetermined time. This is done by detecting the passage through the detection sensor. If the trailing edge of the document does not pass the document detection sensor within a predetermined time, it is determined that a jam has occurred and jam processing is performed.

  In step S2005, the CPU 80 that has detected that the document has been discharged to the discharge tray 13 transfers the read image data to the host computer 2 via the I / F 85, and ends the processing in step S2007.

  On the other hand, if the CPU 80 detects in S2004 that the document is being conveyed in a double-feed state, the CPU 80 performs double-feed processing in S2006.

[Double feed processing]
Next, a sequence when the double feed process is started in S2006 of FIG. 6 will be described with reference to FIGS. In S3000, the CPU 80 that has started the double feed process obtains a double feed region where the originals that were double-fed in S3001 overlap each other from the detection result of the double feed detection sensor 8. That is, as shown in FIG. 8, a double feed area 93 where the original 90a and the original 90b overlap is detected. The double feed area 93 is detected as follows. That is, when the double feed state is detected by the double feed detection sensor 8, the document is continuously conveyed as it is, and the signal (ultrasonic wave) received by the ultrasonic receiver 8 b of the double feed detection sensor 8 is attenuated below a predetermined threshold. This area is referred to as a double feed area 93. Here, the predetermined threshold value is a threshold value of a signal received by the ultrasonic receiver 8b that is set in advance and for determining whether the multifeed is performed or not.

  As described above, when the document is in the double feed state, the signal received by the ultrasonic receiver 8b is attenuated as compared to the case where the document is not in the double feed state. Therefore, the region attenuated exceeding the predetermined threshold is overlapped. It can be obtained as a sending area. In the present embodiment, as described below, since it is only necessary to stop the document discharge while the multi-feed area 93 is passing the discharge roller 12, the multi-feed area 93 may not be strictly determined. . In other words, it is only necessary to detect a part of the actual double feed area and stop the document discharge while the detected double feed area passes through the discharge roller 12. Of course, if a sensor with high accuracy can be used, and by adding other conditions such as document information, it is possible to obtain an area that is almost the same as the actual multi-feed area. It is also possible to perform control.

  In any case, the obtained length in the transport direction of the double feed area 93 is set to D as shown in FIG. Further, since the registration sensor 9 can detect the leading edge of the document, as shown in FIG. 8, a non-multifeed area 94 between the leading edge of the document 90a and the multifeed area 93 where the document 90a and the document 90b do not overlap. Can be requested. The length of the non-multifeed area 94 in the transport direction is d1.

  When the multifeed area 93 and the non-multifeed area 94 are obtained in S3001 of FIG. 7, the CPU 80 determines whether or not the multifeed area 93 has reached the discharge roller 12 in S3002. Here, if the distance on the conveyance path between the registration sensor 9 and the discharge roller 12 is L3, and the conveyance speed of the original is v, the length of the non-multifeed area 94 is d1 from FIG. 8, and therefore the overlap after (L3 + d1) / v. The feeding area 93 reaches the discharge roller 12.

  Therefore, when the CPU 80 detects that the leading edge of the document 90a has passed by the registration sensor 9, the CPU 80 measures time using a timer (not shown). Then, the conveyance of the original 90a and the original 90b is continued until (L3 + d1) / v elapses from the time when the leading edge of the original 90a passes the registration sensor 9.

  In step S3002, the CPU 80 waits for the time (L3 + d1) / v calculated as described above to elapse after the registration sensor 9 detects that the leading edge of the document 90a has passed. Then, in S3003, when this time (L3 + d1) / v has elapsed, the CPU 80 stops discharging and conveying the original 90a and the original 90b. That is, after the non-multifeed area 94 has passed the discharge roller 12, the document discharge operation is stopped. As a result, the document discharge operation can be stopped while the multi-feed region 93 passes the discharge roller 12. In other words, the discharge is stopped in a state where the multifeed area 93 is held between the discharge rollers 12. Thereafter, the CPU 80 ends the process in S3004.

  Note that the CPU 80 waits after the registration sensor 9 detects that the leading edge of the document 90a has passed, since the length D of the multi-feed area 93 in FIG. 8 is (L3 + d1) / v ( Any one is acceptable as long as it is between L3 + d1 + D) / v.

  In the case of the present embodiment, since the document discharge is stopped while the multi-feed area 93 passes through the discharge roller 12 in this way, a part of the multi-feed document is discharged regardless of the multi-feed state. Can be prevented. That is, in any of the states shown in FIGS. 17A and 17B, the multifeed area 93 is obtained, and the discharge of the document is stopped while the multifeed area 93 passes the discharge roller 12. it can. For this reason, as shown in FIG. 18 described above, it is possible to prevent a part of the original (original 90b) from being discharged to the discharge tray 13 due to the double feed state. As a result, it is possible to prevent a document that has been double-fed and a document that has been normally processed and discharged to the discharge tray 13 from being mixed, thereby improving work efficiency. In addition, since the document in the double feed state is conveyed to the discharge roller 12 and then the conveyance and discharge of the document are stopped, it is easy to take out the document in the double feed state.

<Second Embodiment>
A second embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 9, the image reading apparatus 1 </ b> A according to the present embodiment is provided with a paper feed tray 4 </ b> A as a document placement portion for placing a document, and a transport path 14 </ b> A for transporting the document. In the case of this embodiment, the document conveyed from the paper feed tray 4A to the conveyance path 14A is discharged without being folded back as in the first embodiment. Further, the image reading apparatus 1A of the present embodiment does not include the paper discharge tray 13 as in the first embodiment, and the discharged document is directly discharged to the portion where the image reading apparatus 1A is placed. The

  As shown in FIG. 10, the image reading apparatus 1 </ b> A according to the present embodiment also includes a conveyance roller 7, a double feed detection sensor 8, a registration sensor 9, and an image sensor in the conveyance path, as in the first embodiment. 10 and 11, discharge rollers 12, and the like. The configuration and operation of these are the same as in the case of the first embodiment. Also in this embodiment, the image reading apparatus 1A is connected to the host computer 2 as in the case shown in FIG. Further, the image reading apparatus 1 </ b> A has a CPU 80 as in the case shown in FIG. 4, and the CPU 80 controls various means other than the feeding means 81.

  The image reading apparatus 1A according to the present embodiment detects the document double feed and stops the document discharge and conveyance as in the first embodiment, and then stops the document discharge. Control is performed to resume document discharge and document reading. This will be specifically described below.

  First, the sequence of the host computer 2 in this embodiment will be described with reference to FIG. In step S7000, the host computer 2 that has started the image reading start process issues a reading instruction to the image reading apparatus 1A in step S7001. Thereafter, in S7002, the host computer 2 monitors the document feeding state by the image reading apparatus 1A. The CPU 80 of the image reading apparatus 1A instructed to read from the host computer 2 starts the reading process in the same manner as shown in FIG. When it is detected in S2004 in FIG. 6 that the original is being conveyed without being double-fed, the CPU 80 notifies the host computer 2 that the original is being conveyed normally.

  In S7002 of FIG. 11, the host computer 2 that has received the notification that the image reading apparatus 1A is normally conveying the document receives the image data transferred from the image reading apparatus 1A in S7005, and performs appropriate processing. Execute.

  On the other hand, if a double feed state is detected in S2004 of FIG. 6, a double feed process is performed in S2006. In the case of this embodiment, the multifeed process is performed according to the sequence shown in FIG. In S5000 of FIG. 12, the CPU 80 of the image reading apparatus 1A that has started the multi-feed process detects a multi-feed area 93 (see FIG. 8) in S5001, as in the first embodiment.

  In S5002, the CPU 80 determines whether or not the double feed area 93 has reached the discharge roller 12 as in the first embodiment. Next, in S5002, the CPU 80, which has waited for the time until the double feed area 93 reaches the discharge roller 12 to pass, stops discharging and conveying the original in S5003. At this time, the document reading by the image sensors 10 and 11 is continued. That is, even after the double feed detection sensor 8 detects the double feed of the original, the reading of the original by the image sensors 10 and 11 is continued until the discharge of the original is stopped.

  Here, when the discharge of the document is stopped, the document 90a and the document 90b may be stopped at the position shown in FIG. In FIG. 13, the rear end portion of the document 90 b that overlaps the document 90 a does not pass through the image sensors 10 and 11. However, as shown in FIG. 14, the conveyed document may be a document in which a sticky note 95 is attached to the document 90b. In other words, the document 90 a may be a sticky note 95. In this case, the operator may intentionally attach the sticky note 95, and even in such a case, it is contrary to the operator's intention to determine the double feed error. Therefore, in the present embodiment, the following processing is executed.

  First, in step S5003, the CPU 80 stops the document discharge and conveyance, and interrupts image reading in step S5004 in accordance with the reduction in the conveyance speed. In step S5005, the CPU 80 notifies the host computer 2 that a double feed state has occurred. In step S5006, the CPU 80 monitors whether the action for the double feed state that has occurred is confirmed.

  On the other hand, in S7002 of FIG. 11, the host computer 2 that has detected that the original is being conveyed in a double-feed state monitors an instruction from the operator as to whether or not the generated double-feed state should be canceled in S7003. . In the present embodiment, the host computer 2 corresponds to a release unit that cancels the stop of document discharge. The host computer 2 that has received an instruction from the operator to process the double feed as an error notifies the CPU 80 of the image reading apparatus 1A to that effect, and then ends the processing in S7006.

  On the other hand, the host computer 2 that has received an instruction from the operator to perform the process of canceling the double feed issues a cancel instruction to the CPU 80 of the image reading apparatus 1A in S7004, and performs the image reading process in S7005. Resume.

  In S5006 of FIG. 12, the CPU 80 of the image reading apparatus 1A that has detected that the treatment for the double feed state has been confirmed performs processing according to the treatment that has been confirmed in S5007. If the confirmed process is an instruction to process the double feed state as an error, the CPU 80 ends the double feed process in S5008. On the other hand, if the confirmed process is an instruction to cancel the double feed state, the CPU 80 performs a double feed cancel process in S5009.

  The double feed canceling process is performed in a sequence as shown in FIG. In step S6000, the CPU 80 of the image reading apparatus 1A that has started the double feed canceling process issues an instruction to resume image reading in step S6001, and in step S6002, discharges and resumes the document. Restart.

  Here, when resuming image reading, there is a possibility that the image reading position may deviate from the position where the conveyance is stopped. For this reason, when the motor M (see FIG. 1) for driving the various rollers is a DC motor, an encoder for detecting the rotation angle of the motor is provided, and when the reading is resumed based on the signal from the encoder, the reading position Is preferably corrected. If the motor M is a pulse motor, the number of pulses can be monitored to correct the reading position when reading is resumed.

  Next, in step S6003, the CPU 80 monitors whether the document is discharged. In step S6003, the CPU 80 that has detected that the document has been discharged stops the conveyance in step S6004, and ends the double feed cancellation processing in step S6005.

  In the case of the present embodiment, even when the document discharge is stopped due to the multi-feed, the document reading can be resumed according to the instruction of the operator. For this reason, for example, the operator can read an image of a document with a sticky note attached, and work efficiency can be improved. Other structures and operations are the same as those in the first embodiment.

<Other embodiments>
In each of the above-described embodiments, the structure in which the ultrasonic wave is desired to be used as the double feed detection unit has been described. However, for example, it is possible to detect double feed based on a difference in light transmission amount using light. In this case, if the area where the transmission amount is reduced is set as the double feeding area, the control as in the present invention is possible.

  The control means may be provided in an external terminal such as a host computer in addition to being provided in the image reading apparatus main body. In each of the above-described embodiments, the release unit that cancels the stop of document discharge is the host computer. However, the release unit may be provided in the image reading apparatus main body. Further, an instruction such as image reading start may be given on the image reading apparatus side.

  DESCRIPTION OF SYMBOLS 1, 1A ... Image reading device, 2 ... Host computer (release part), 5 ... Feed roller (conveyance means), 7 ... Conveyance roller (conveyance means), 8 ... Multi feed Detection sensor (double feed detection means), 8a ... ultrasonic transmitter (ultrasonic transmission means), 8b ... ultrasonic receiver (ultrasonic reception means), 9 ... resist sensor (tip detection means) , Image sensors 10, 11 (reading means), 12 ... discharge rollers (discharge means), 14, 14A ... transport path, 80 ... CPU (control means), 90a, 90b ... original, 93 ... Multi-feed area, 94 ... Non-multi-feed area, 95 ... Sticky notes

Claims (4)

Conveying means for conveying the document in the conveying path;
Reading means for reading a document conveyed in the conveyance path;
Discharging means for discharging the document read by the reading means;
A double feed detection means for detecting double feed of documents in the conveyance path;
Control means for stopping the document discharge operation while the double feed area of the document obtained from the detection result of the double feed detection means passes through the discharge means;
An image reading apparatus. A leading edge detecting means for detecting a leading edge of the document conveyed in the conveyance path;
The control means stops discharge of a document after a non-multifeed area between the leading edge of the document detected by the leading edge detection means and the multifeed area passes through the discharge means;
The image reading apparatus according to claim 1, wherein: The double feed detection means receives ultrasonic waves transmitted from the ultrasonic wave transmission means and ultrasonic wave transmission means that are disposed on both sides in the thickness direction of the document conveyed in the conveyance path. Ultrasonic receiving means for
The control means sets the area where the ultrasonic wave received by the ultrasonic wave receiving means is attenuated from a predetermined threshold as the double feed area.
The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus. A release unit for releasing the stop of document discharge,
The control means continues reading the document by the reading means until the document discharge is stopped even after the double feed detection means detects the double feed, and the document by the reading means is stopped along with the stop of the document discharge. Reading is interrupted, and when the stopping of the document discharge is canceled by the release unit, the document discharge and the document reading are resumed.
The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus.

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