JP2010215358A - Image reading device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reading device for properly detecting a paper medium longer than the path length of an inversion path before the front end of the paper medium reaches a selection part of a reading path with respect to the paper medium being delivered from a storage part to a conveyance path. <P>SOLUTION: This image reading device consists of a separating part separating the paper medium in the storage part and delivering it to the conveyance path, a co-rotated roller arranged at a position wherein the distance to the branch point of the reading path is longer than the path length of the inversion path, which is contacted with the paper medium in the storage part and submissively rotated when the paper medium is delivered by the separating part, a roller rotational amount detecting part detecting the rotational amount of the co-rotated roller, a paper length determining part determining the length of the paper medium in the conveying direction based on the rotational amount from the start of delivery of the paper medium by the separating part, and a conveyance control part controlling the conveyance of the paper medium based on the determination result of the length. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image reading apparatus, and more specifically, a single-sided reading path that allows a reading unit to read one side of a paper medium, and a paper medium guided from a storage unit to a reading unit via a reading path selection unit. The present invention also relates to an improvement in an image reading apparatus having a double-sided reading path that guides the reading medium again through a reversing path for reversing the paper medium.

  2. Description of the Related Art Conventionally, there is known a two-pass one-scanner type image reading apparatus including a single-sided path for reading one side of a document by a reading unit that reads an image from a document being conveyed and a double-sided path for reading both sides. Yes. As the single-sided path, for example, a route is used in which the document is guided from the storage unit to the reading unit via a path branch point and then guided to the discharge unit. On the other hand, as the double-sided path, a path is used in which the document is guided from the storage unit to the reading unit via a path branch point, and then guided to the reading unit again via an inversion path for inverting the document.

  In the case of the image reading apparatus described above, if the length of the document in the conveyance direction is longer than the path length of the reversing path, the front end of the document is reversed before the trailing edge of the document is guided into the reversing path. You will be guided to the entrance of the route. Therefore, if such a document is guided into the reversing path, a paper jam occurs near the entrance / exit, and double-sided reading cannot be performed correctly. Therefore, the document is longer than the reversing path length, that is, the reversing path length. It is necessary to detect in advance. In particular, in order to retract a document longer than the reverse path length to a single-sided path, it is detected whether the length of the original is longer than the reverse path length before the front edge of the original reaches the branch point of the path. It is desirable to be possible.

  Therefore, it is conceivable to arrange an optical sensor in the storage unit and detect the length of the document stored in the storage unit in the conveyance direction. However, although this method can detect whether or not a document longer than a certain length exists in the document group, there is a problem in that it cannot detect the length of the document being sent from the storage unit to the conveyance path. . It is also conceivable to arrange an optical sensor on the transport path and detect the front and rear edges of the document to determine the length of the document. However, with this method, the length cannot be detected until the document has passed through the optical sensor, so that the front edge of the document reaches the path branch point before the length can be detected.

  As another method for detecting the length of the paper as a paper medium in the conveyance direction, a rotation roller that contacts the document in the container and rotates when the document is sent to the conveyance path is provided. A technique for detecting the length from the rotation amount of the roller has been conventionally known (for example, Patent Document 1). However, in the method of detecting the length from the rotation amount of the follower roller, the front end of the document reaches the branch point of the path before it can be detected whether the length of the document is longer than the reverse path length. There was a problem that a case would occur.

JP-A-6-130762

  The present invention has been made in view of the above circumstances, and determines whether or not the paper medium is longer than the reversing path length before the front end of the paper medium reaches the branch point of the reading path. It is an object of the present invention to provide an image reading apparatus that can be used. In particular, it is possible to provide an image reading apparatus capable of correctly detecting a paper medium longer than the reversing path length until the front end of the paper medium reaches the branch point with respect to the paper medium being sent from the storage unit to the conveyance path. With the goal.

  An image reading apparatus according to a first aspect of the present invention includes a storage unit that stores a paper medium, a transport unit that transports the paper medium from the storage unit to the discharge unit, and a reading unit that reads an image from the paper medium being transported. A single-sided reading path for causing the reading unit to read one side of the paper medium and a double-sided reading path for reading both sides of the paper medium, and the single-sided reading path and the double-sided reading. A reading path selection unit for selecting one of the paths, and the double-sided reading path guides the paper medium from the storage unit to the reading unit via the branch point, and then reverses the paper medium. An image reading apparatus that guides the reading unit again through the reversing path to be separated, the separating unit that separates the paper medium in the storage unit and sends it to the conveyance path, and the distance to the branch point is reversed. Position longer than the path length of the path A rotating roller that is disposed and contacts the paper medium in the storage unit and rotates when the paper medium is sent by the separating unit; a roller rotation amount detection unit that detects a rotation amount of the rotating roller; and A paper length determination unit that determines the length of the paper medium in the transport direction based on the rotation amount from the start of the paper medium delivery by the separation unit, and a paper length determination unit that determines the length of the paper medium based on the length determination result. And a conveyance control unit that controls conveyance.

  According to such a configuration, the follow-up roller for detecting the length that is rotated in contact with the paper medium in the storage unit has a reverse path length, that is, a path length of the reverse path. Therefore, it is possible to determine whether or not the paper medium is longer than the reverse path length before the front end of the paper medium reaches the branch point. In particular, with respect to a paper medium being sent from the storage unit to the conveyance path, it is possible to correctly detect a paper medium whose length in the conveyance direction is longer than the reverse path length before the front end of the paper medium reaches the branch point. . Accordingly, it is possible to perform conveyance control by determining whether or not the paper medium is longer than the reverse path length before the front end of the paper medium reaches the branch point of the reading path. In addition, since the length of the paper medium is determined based on the rotation amount of the follower roller after the separation unit starts sending the paper medium, the separation unit sends the paper medium after the paper medium in the storage unit is picked up. The rotation of the follower roller until it is started can be ignored, and the length detection accuracy can be improved.

  In addition to the above configuration, the image reading apparatus according to the second aspect of the present invention is configured such that the distance between the separation unit and the follower roller is shorter than the path length of the reversing path. According to such a configuration, since the follower roller is disposed at a position where the distance to the separation unit is shorter than the reverse path length, a paper medium whose length in the transport direction is longer than the reverse path length is always detected correctly. can do. Further, whether or not the paper medium is shorter than the distance between the separation unit and the follower roller can be determined based on the presence or absence of the rotation of the follower roller at the start of the paper medium delivery.

  An image reading apparatus according to a third aspect of the present invention includes a storage unit that stores a paper medium, a transport unit that transports the paper medium from the storage unit to the discharge unit, and a reading unit that reads an image from the paper medium being transported. A single-sided reading path for causing the reading unit to read one side of the paper medium and a double-sided reading path for reading both sides of the paper medium, and the single-sided reading path and the double-sided reading. A reading path selection unit for selecting one of the paths, and the double-sided reading path guides the paper medium from the storage unit to the reading unit via the branch point, and then reverses the paper medium. An image reading apparatus that guides the reading unit again through the reversing path to be separated, the separating unit that separates the paper medium in the storage unit and sends it to the conveyance path, and the distance to the branch point is reversed. Position longer than the path length of the path A rotating roller that is disposed and contacts the paper medium in the storage unit and rotates when the paper medium is sent by the separating unit; a roller rotation amount detection unit that detects a rotation amount of the rotating roller; and Based on the paper front end detection sensor that is disposed between the reading path selection unit and the separation unit and detects the front end of the paper medium being conveyed, and the rotation amount after the front end of the paper medium is detected, the paper A paper length determination unit that determines a length in the conveyance direction of the medium; and a conveyance control unit that controls conveyance of the paper medium based on the determination result of the length, and includes the paper front end detection sensor and the follower The distance between the rollers is configured to be shorter than the path length of the reversing path.

  According to such a configuration, the follow-up roller for detecting the length that is rotated in contact with the paper medium in the storage unit has a reverse path length, that is, a path length of the reverse path. Longer than the reverse path length, the paper medium is longer than the reverse path length before the front end of the paper medium reaches the branch point. Can always be determined correctly. In particular, it is possible to always correctly detect a paper medium whose length in the transport direction is longer than the reversing path length by the time the front end of the paper medium reaches the branch point with respect to the paper medium being sent from the storage unit to the transport path. it can. Accordingly, it is possible to perform conveyance control by determining whether or not the paper medium is longer than the reverse path length before the front end of the paper medium reaches the branch point of the reading path. Further, the length of the paper medium is determined based on the rotation amount of the follower roller after the front edge of the paper medium is detected by the paper front edge detection sensor disposed between the reading path selection unit and the separation unit. The rotation of the follower roller while the medium is conveyed from the storage unit to the paper front end detection sensor can be ignored, and the length detection accuracy can be improved. The paper front edge detection sensor here is a sensor that can detect at least the front edge of the paper medium being transported. It detects not only the front edge but also the front edge and the rear edge of the paper medium. Possible sensors are also included.

  According to a fourth aspect of the present invention, there is provided an image reading apparatus for storing a paper medium, a transport unit for transporting the paper medium from the storage section to the discharge section, and a reading section for reading an image from the paper medium being transported. A single-sided reading path for causing the reading unit to read one side of the paper medium and a double-sided reading path for reading both sides of the paper medium, and the single-sided reading path and the double-sided reading. A reading path selection unit for selecting one of the paths, and the double-sided reading path guides the paper medium from the storage unit to the reading unit via the branch point, and then reverses the paper medium. An image reading apparatus that guides the reading unit again through the reversing path to be separated, the separating unit that separates the paper medium in the storage unit and sends it to the conveyance path, and the distance to the branch point is reversed. Longer than the path length of the path, above A follower roller disposed at a position where the distance to the separating unit is shorter than the path length of the reversing path, contacting the paper medium in the housing unit, and rotating when the paper medium is sent by the separating unit; Based on the roller rotation detection unit that detects the rotation of the follower roller and the rotation duration time of the follower roller from the start of feeding of the paper medium by the separation unit, the length in the transport direction of the paper medium is reversed. A paper length determination unit that determines whether or not the path length is longer than a path length and a conveyance control unit that controls the conveyance of the paper medium based on the determination result of the length.

  According to such a configuration, the follow-up roller for detecting the length that is rotated in contact with the paper medium in the storage unit has a reverse path length, that is, a path length of the reverse path. Longer than the reversing path length, and whether or not the paper medium is longer than the reversing path length before the front end of the paper medium reaches the branch point. It can always be judged correctly. In particular, it is possible to always correctly detect a paper medium whose length in the transport direction is longer than the reversing path length by the time the front end of the paper medium reaches the branch point with respect to the paper medium being sent from the storage unit to the transport path. it can. Accordingly, it is possible to perform conveyance control by determining whether or not the paper medium is longer than the reverse path length before the front end of the paper medium reaches the branch point of the reading path. In addition, since the length of the paper medium is determined based on the rotation duration time of the follower roller after the separation unit starts sending the paper medium, the separation unit sends out the paper medium in the storage unit after being picked up. The rotation of the follower roller until the start of the rotation can be ignored, and the length detection accuracy can be improved. Furthermore, whether or not the paper medium is shorter than the distance between the separation unit and the follower roller can be determined by the presence or absence of rotation of the follower roller at the start of the paper medium feed.

  An image reading apparatus according to a fifth aspect of the present invention is a storage unit that stores a paper medium, a transport unit that transports the paper medium from the storage unit to the discharge unit, and a reading unit that reads an image from the paper medium that is being transported. A single-sided reading path for causing the reading unit to read one side of the paper medium and a double-sided reading path for reading both sides of the paper medium, and the single-sided reading path and the double-sided reading. A reading path selection unit for selecting one of the paths, and the double-sided reading path guides the paper medium from the storage unit to the reading unit via the branch point, and then reverses the paper medium. An image reading apparatus that guides the reading unit again through the reversing path to be separated, the separating unit that separates the paper medium in the storage unit and sends it to the conveyance path, and the distance to the branch point is reversed. Position longer than the path length of the path A rotation roller that is disposed and contacts the paper medium in the storage unit and rotates when the paper medium is delivered by the separation unit; a roller rotation detection unit that detects rotation of the rotation roller; and the reading path A paper front end detection sensor that is disposed between the selection unit and the separation unit and is located at a position where the distance to the follower roller is substantially the same as the path length of the reversing path, and detects the front end of the paper medium being conveyed. And determining whether the length in the transport direction of the paper medium is longer than the path length of the reversing path based on the presence / absence of rotation of the follower roller when the front end of the paper medium is detected. A paper length determination unit and a conveyance control unit that controls the conveyance of the paper medium based on the length determination result are configured.

  According to such a configuration, the follow-up roller for detecting the length that is rotated in contact with the paper medium in the storage unit has a reverse path length, that is, a path length of the reverse path. Longer than the reverse path length, and the paper medium is longer than the reverse path length before the front end of the paper medium reaches the branch point. It can always be determined correctly. In particular, it is possible to always correctly detect a paper medium whose length in the transport direction is longer than the reversing path length by the time the front end of the paper medium reaches the branch point with respect to the paper medium being sent from the storage unit to the transport path. it can. Accordingly, it is possible to perform conveyance control by determining whether or not the paper medium is longer than the reverse path length before the front end of the paper medium reaches the branch point of the reading path. Further, since the length of the paper medium is determined based on the presence or absence of rotation of the follower roller when the front edge of the paper medium is detected by the paper front edge detection sensor disposed between the reading path selection unit and the separation unit, The rotation of the follower roller while the paper medium is conveyed from the storage unit to the paper front end detection sensor can be ignored, and the length detection accuracy can be improved.

  An image reading apparatus according to a sixth aspect of the present invention includes, in addition to the above configuration, positioning means for positioning the positions in the transport direction of the front ends of the two or more paper media stacked in the storage unit.

  According to the image reading apparatus of the present invention, the length detection follower roller that rotates in contact with the paper medium in the container is disposed at a position where the distance to the branch point of the read path is longer than the reversing path length. Therefore, it is possible to determine whether or not the paper medium is longer than the reverse path length before the front end of the paper medium reaches the branch point. In particular, with respect to a paper medium being sent from the storage unit to the conveyance path, it is possible to correctly detect a paper medium whose length in the conveyance direction is longer than the reverse path length before the front end of the paper medium reaches the branch point. . Accordingly, it is possible to perform conveyance control by determining whether or not the paper medium is longer than the reverse path length before the front end of the paper medium reaches the branch point of the reading path.

1 is an external view showing a configuration example of an image reading apparatus according to a first embodiment of the present invention, and shows a multifunction peripheral 100 as an example of the image reading apparatus. FIG. 2 is a cross-sectional view illustrating a configuration example of a main part of the multifunction peripheral 100 of FIG. 1, schematically illustrating the state around the ADF unit 10. FIG. 2 is a block diagram illustrating a configuration example of a main part of the multifunction peripheral 100 of FIG. 1, in which a reading control unit 60 is illustrated. 3 is a flowchart illustrating an example of an operation at the time of double-sided reading in the multifunction peripheral 100 of FIG. 1. FIG. 6 is a cross-sectional view illustrating a configuration example of an image reading apparatus according to a second embodiment of the present invention, and schematically illustrates the surroundings of the ADF unit 210 of the multifunction peripheral 200. FIG. 6 is a block diagram illustrating a configuration example of a main part of the MFP 200 in FIG. 5, in which a reading control unit 70 is illustrated. 7 is a flowchart showing an example of an operation at the time of double-sided reading in the multifunction machine 200 of FIG. 6. FIG. 6 is a block diagram showing an example of the configuration of an image reading apparatus according to Embodiment 3 of the present invention, in which a reading control unit 80 is shown. 10 is a flowchart illustrating an example of an operation at the time of double-sided reading in the image reading apparatus of FIG. 8. FIG. 10 is a block diagram showing an example of the configuration of an image reading apparatus according to Embodiment 4 of the present invention, in which a reading control unit 90 is shown. 12 is a flowchart illustrating an example of an operation at the time of double-sided reading in the image reading apparatus of FIG. 10.

Embodiment 1 FIG.
<Multifunction device>
FIG. 1 is an external view showing a configuration example of an image reading apparatus according to Embodiment 1 of the present invention, and shows a multifunction peripheral 100 as an example of the image reading apparatus. A multifunction peripheral (MFP) 100 is an image processing apparatus having functions such as a scanner function, a printer function, and a FAX (facsimile) transmission / reception function, and can selectively execute these functions.

  The multifunction machine 100 includes an ADF (Auto Document Feeder) unit 10 provided with a paper feed tray unit 11 and a paper discharge tray unit 12, and a main body unit 20 incorporating a scanner unit, a printing unit, a communication processing unit, and the like. . The paper feed tray unit 11 is a document storage unit that stores a document.

  The ADF unit 10 separates the originals in the paper feed tray unit 11 one by one and sends them to the conveyance path. The ADF unit 10 causes the scanner unit of the main body unit 20 to read the image and discharge it into the paper discharge tray unit 12. Device. In the ADF unit 10, a paper feed tray unit 11 and a paper discharge tray unit 12 are both disposed at the right end of the ADF unit 10 housing. The paper discharge tray unit 12 is located below the paper feed tray unit 11. Located on the side.

  The main body 20 is provided with an operation panel 21 on the top surface of the housing, and a paper feed cassette 22 for storing printing paper at the bottom of the housing. The operation panel 21 is provided with various operation keys such as a start key and a numeric keypad, and a display unit for displaying operation information, an operation state, and the like.

<ADF part>
FIG. 2 is a cross-sectional view illustrating a configuration example of a main part of the multifunction peripheral 100 of FIG. 1, and schematically illustrates the periphery of the ADF unit 10. The ADF unit 10 has a single-sided path and a double-sided path as a reading path for guiding the document A1 sent from the paper feed tray unit 11 to the paper discharge tray unit 12 via the scanner unit 24. The path selection unit 5 It can be switched by controlling. The document A1 is a paper medium on which images such as characters, symbols, and figures are recorded in advance by printing or the like.

  A part of the upper surface of the main body 20 casing is a flat bed on which optical reading is performed while moving the light source unit 23 and the scanner unit 24 in the left-right direction. The ADF unit 10 is arranged with its lower surface facing the flat bed of the main body unit 20.

  The light source unit 23 is a projector that emits light to the original on the flat bed. The scanner unit 24 is a reading unit that optically reads an image from a document, and includes an image sensor that receives light reflected by the document.

  The light source unit 23 and the scanner unit 24 are used for an auto document feed operation for reading an image from the document A1 being conveyed by the ADF unit 10 and a direct reading operation for reading a document placed on the flat bed of the main body unit 20. .

  The ADF unit 10 includes a pickup roller 1, a separation roller 2, a retard roller 3, transport rollers 4, 41 to 50, and a path selection unit 5 in addition to the paper feed tray unit 11 and the paper discharge tray unit 12. . Further, the document tray 31, the document stopper 32, the guide plate 33 and the length detection roller 35 are disposed in the paper feed tray unit 11. For example, the document A 1 having different lengths in the transport direction, in this figure, in the left-right direction. A plurality of originals A1 are accommodated in a mixed state.

  The document table 31 is a thin flat plate having a main surface disposed substantially parallel to a horizontal plane and urged upward by a biasing means such as a spring, and the document A1 placed on the upper surface is picked up by the pickup roller 1. Is pressed against. The document stopper 32 positions the front end of each document A1, that is, the position in the transport direction of the paper feed direction, that is, the left end in this figure, with respect to the plurality of documents A1 stacked and placed on the document table 31. Means.

  The guide plate 33 is a regulating unit that regulates the positions of the plurality of documents A1 stacked in the sheet feeding tray unit 11 in the direction intersecting the transport direction and guides each document A1 in the transport direction. It consists of a flat plate arranged in the horizontal direction.

  The pickup roller 1, the separation roller 2, and the retard roller 3 are separation units that separate the originals A1 in the paper feed tray unit 11 one by one and send them to the conveyance path B1. The pick-up roller 1 is a transport roller for taking out the originals A1 in the paper feed tray unit 11 one by one by urging the originals A1 in the feeding direction and sending them out to the separation roller 2 side.

  Here, a large number of documents A1 are stacked on the document table 31 biased upward, and the uppermost document A1 is always in contact with the pickup roller 1 regardless of the stacking amount of the documents A1. Shall.

  The separation roller 2 and the retard roller 3 are separation devices for separating the document A1 sent by the pickup roller 1 one by one and sending it to the conveyance path B1. The separation roller 2 is a transport roller that transports the document A1 in the feed direction.

  The retard roller 3 is a driven roller for applying a frictional force in the returning direction to the document A1 in the double feed state, and the circumferential surface thereof is arranged to face the separation roller 2 so as to sandwich the document A1 being conveyed. . That is, the separation roller 2 is disposed on the upper side of the conveyance path B1, while the retard roller 3 is disposed on the lower side of the conveyance path B1. The retard roller 3 is provided with a torque limiter so as to be driven to rotate when a torque exceeding a certain level is applied.

  The single-sided path is a reading path that causes the scanner unit 24 to read one surface of the document A1, that is, the upper surface (first surface) of the document A1 accommodated in the paper feed tray unit 11, and includes a conveyance path B1, It consists of a path branch point and transport paths B11 and B2. This single-sided path is a path for guiding the document A1 from the paper feed tray section 11 to the discharge section 34 via the transport path B1, the branch point, the transport path B11, the scanner section 24, and the transport path B2.

  The discharge unit 34 is an opening for discharging a read paper medium provided in the housing of the ADF unit 10, and the document A1 discharged from the discharge unit 34 is accommodated in the discharge tray unit 12. .

  On the other hand, in the duplex path, the scanner unit 24 reads both the first surface of the document A1 and the other surface, that is, the lower surface (second surface) of the document A1 in the paper feed tray unit 11. The reading path includes a conveyance path B1, a path branch point, and conveyance paths B21, B22, and B2. This double-sided path is a path for guiding the document A1 from the paper feed tray unit 11 to the discharge unit 34 via the conveyance path B1, the branch point, the conveyance path B21, the scanner unit 24, the conveyance path B22, the scanner unit 24, and the conveyance path B2. It has become.

  The conveyance path B <b> 1 is a conveyance path common to the single-sided path and the double-sided path, and a conveyance roller 4 that conveys the document A <b> 1 sent by the separation roller 2 to the path selection unit 5 is provided.

  The path selection unit 5 is a reading path selector that selects either a single-sided path or a double-sided path, and is arranged at a branch point of the path. For example, the path selection unit 5 switches the reading path by rotating a claw-shaped rotating member.

  The conveyance path B <b> 11 is a conveyance path used for reading the first surface of the document A <b> 1, and is provided with conveyance rollers 41 to 44 that convey the document A <b> 1 that has passed through the path selection unit 5 to the scanner unit 24. The conveyance path B2 is a conveyance path common to the single-sided path and the double-sided path, and is provided with conveyance rollers 45 and 46 for conveying the original A1 after image reading by the scanner unit 24 to the discharge unit 34.

  The conveyance path B21 is a conveyance path that conveys the document A1 that has passed through the path selection unit 5 to the scanner unit 24 in order to cause the scanner unit 24 to read the second surface of the document A1, and includes conveyance rollers 47 and 45. Has been.

  The conveyance path B22 is a reversing path for inverting the original A1 after the second surface is read by the scanner unit 24 and causing the scanner unit 24 to read the first surface of the original A1, and conveying rollers 43, 44, 48 to 50 are arranged.

  A part of the transport paths B11 and B22 is a transport path common to the single-sided path and the double-sided path, and the transport rollers 43 and 44 are disposed in a common part of both paths.

  The pickup roller 1, the separation roller 2, the transport rollers 4 and 41 to 50 are transport means for transporting the document A1 from the paper feed tray unit 11 to the discharge unit 34, and are driven by a roller driving unit, for example, a common electric motor. The

  The conveyance rollers 4, 41 to 43, 46, and 47 to 50 include a driving roller that is rotationally driven by a roller driving unit, and a driven roller that is disposed to face the driving roller across the conveyance path. The conveying rollers 44 and 45 are triple rollers each composed of a driving roller and two driven rollers arranged so as to sandwich the driving roller.

  The transport roller 44 transports the document A1 sent out by the transport roller 43 to the scanner unit 24, and transports the document A1 after the second surface read by the scanner unit 24 to the transport roller 48. The transport roller 45 transports the document A1 sent by the transport roller 47 to the scanner unit 24, and transports the document A1 after the first surface read by the scanner unit 24 to the transport roller 46.

  In the single-sided pass, when the document A1 is transported from the paper feed tray unit 11 to the discharge unit 34, the separation roller 2, the transport roller 4, the path selection unit 5, the transport rollers 41 to 44, the scanner unit 24, and the transport rollers 45 and 46 are used. Is a route that guides in this order.

  On the other hand, the double-sided path includes the separation roller 2, the conveyance roller 4, the path selection unit 5, the conveyance rollers 47 and 45, the scanner unit 24, the conveyance rollers 44, 48 to 50, 43 and 44, the scanner unit 24, the conveyance rollers 45 and 46. Is a route that guides in this order. That is, in the double-sided path, the document A1 is guided from the paper feed tray unit 11 to the scanner unit 24 via the path selection unit 5, and then guided again to the scanner unit 24 via the conveyance path B22 that reverses the document A1. It is a route.

  The length detection roller 35 is a follower roller that contacts the document A1 in the paper feed tray unit 11 and rotates when the document A1 is sent out by the separation roller 2, and the transport direction of the document A1 is based on the amount of rotation. Can be detected.

  This length detection roller 35 detects whether the document A1 is longer than the path length of the conveyance path B22 before the front end of the document A1 reaches the branch point of the path. The distance D1 is arranged at a position longer than the path length. Specifically, the path length of the transport path B22 is set as the reverse path length D, and the distance D1 is arranged at a position longer than the reverse path length D (D1> D). Further, the length detection roller 35 is disposed at a position where the distance D2 to the separation roller 2 is shorter than the reverse path length D in order to always correctly detect the document A1 whose length in the transport direction is longer than the reverse path length D. (D2 <D).

<Reading control unit>
FIG. 3 is a block diagram illustrating a configuration example of a main part of the multifunction peripheral 100 of FIG. 1. The reading control unit controls the path selection unit 5 based on an input signal from the operation panel 21 and drives the conveyance roller. 60 is shown. The reading control unit 60 includes a roller rotation amount detection unit 61, a paper length determination unit 62, a conveyance control unit 63, a roller drive unit 64, and a rotation amount reset unit 65, and selects a path based on an input signal from the operation panel 21. The unit 5 is controlled to drive the conveying roller.

  The roller driving unit 64 performs an operation of rotationally driving the pickup roller 1, the separation roller 2, the transport rollers 4 and 41 to 50. The conveyance control unit 63 is a control unit that controls conveyance of the document A <b> 1, and performs an operation of controlling the path selection unit 5 and the roller driving unit 64 based on an input signal from the operation panel 21.

  For example, an operation of switching the conveyance path to the reading path designated by the user and driving the conveyance roller based on an instruction to start reading is performed.

  The roller rotation amount detection unit 61 detects the rotation amount of the length detection roller 35 based on the reset signal from the rotation amount reset unit 65, and outputs the detection result to the paper length determination unit 62. . Here, it is assumed that an operation for detecting the rotation amount after reset, for example, the rotation angle or the rotation speed of the length detection roller 35 at regular intervals is performed.

  The paper length determination unit 62 performs an operation of determining the length of the document A1 in the conveyance direction based on the detection result by the roller rotation amount detection unit 61 and outputting the determination result to the conveyance control unit 63. The rotation amount reset unit 65 performs an operation of generating a reset signal for resetting the detection value of the rotation amount when the separation roller 2 starts to send the document A1.

  In the paper length determination unit 62, the rotation amount of the length detection roller 35 from the start of sending of the document A1 by the separation roller 2 is converted into the length in the conveyance direction of the document A1, and the separation roller 2 and the length detection roller 35 are converted into this. The operation of determining the paper length by adding the distance D2 between them is performed.

  In the conveyance control unit 63, an operation for controlling the conveyance of the document A <b> 1 is performed based on the length determination result by the paper length determination unit 62. For example, when it is detected that the length in the transport direction of the document A1 being transported is longer than the reverse path length D, control for stopping the transport until the front end of the document A1 reaches the path selection unit 5 is performed. Done.

<Double-sided scanning operation>
Steps S101 to S107 in FIG. 4 are flowcharts showing an example of the operation at the time of duplex reading in the multi-function device 100 in FIG. First, the conveyance control unit 63 controls the roller driving unit 64 to rotationally drive the conveyance roller (step S101).

  Next, the roller rotation amount detection unit 61 detects the rotation amount of the length detection roller 35 after the separation roller 2 starts to send the document A1, and the paper length determination unit 62 detects the rotation amount based on the rotation amount detection result. The length of the document A1 in the conveyance direction is determined (steps S102 and S103).

  At this time, the conveyance control unit 63 immediately stops the conveyance if the length in the conveyance direction of the original A1 being conveyed is longer than the upper limit, that is, the reversing path length D (step S104). S107).

  On the other hand, if the length in the transport direction does not exceed the upper limit, the transport of the document A1 is continued as it is, and the processing procedure from step S102 to step S104 is repeated until the length detection roller 35 stops rotating (step S104). S105).

  If the length detection roller 35 stops rotating without the length determination value exceeding the upper limit, the transport control unit 63 transports the document A1 to the scanner unit 24 as it is, and causes the scanner unit 24 to perform image reading. This process is finished (step S106).

  According to the present embodiment, the length detection roller 35 that rotates in contact with the document A1 in the paper feed tray unit 11 is disposed at a position where the distance D1 to the path branch point is longer than the reverse path length D. Therefore, it is possible to determine whether or not the document A1 is longer than the reverse path length D before the front end of the document A1 reaches the branch point. Further, since the length of the original A1 is determined based on the rotation amount of the length detection roller 35 after the separation roller 2 starts sending the original A1, the original A1 in the paper feed tray unit 11 is picked up. Thus, the rotation of the length detection roller 35 from when the separation unit starts to the delivery can be ignored, and the length detection accuracy can be improved.

  Further, since the length detection roller 35 is disposed at a position where the distance D2 to the separation roller 2 is shorter than the reverse path length D, the document A1 whose length in the transport direction is longer than the reverse path length D is always detected correctly. can do. Further, whether or not the document A1 is shorter than the distance D2 between the separation roller 2 and the length detection roller 35 can be determined by the presence or absence of rotation of the length detection roller 35 at the start of sending the document A1.

Embodiment 2. FIG.
In the first embodiment, an example in which the length of the document A1 in the conveyance direction is determined based on the rotation amount of the length detection roller 35 from the start of the document A1 delivery by the separation roller 2 has been described. On the other hand, in the present embodiment, a case will be described in which the length of the document A1 is determined based on the rotation amount of the length detection roller 35 after the front end of the document A1 is detected by the paper detection sensor.

  FIG. 5 is a cross-sectional view showing a configuration example of the image reading apparatus according to the second embodiment of the present invention, and schematically shows the surroundings of the ADF unit 210 of the multi-function device 200. The ADF unit 210 is different from the ADF unit 10 of FIG. 2 in that a paper front end detection sensor 71 is provided.

  The paper front edge detection sensor 71 is disposed between the path selection unit 5 and the separation roller 2 and can detect at least the front edge of the document A1 being conveyed, and detects the presence or absence of a paper medium at a predetermined repetition interval. Thus, it is possible to detect the passage time of the front end of the document A1 being conveyed. The paper front edge detection sensor 71 may be a sensor capable of detecting only the front edge of the document A1 being conveyed, or may be a sensor capable of detecting the front edge and the rear edge of the document A1 being conveyed.

  As such a paper front end detection sensor 71, for example, an optical sensor including a light projecting unit that emits detection light and a light receiving unit that receives detection light from the light projecting unit can be used.

  The length detection roller 35 is a position where the distance D3 to the paper front edge detection sensor 71 is shorter than the reverse path length D in order to always correctly detect the document A1 whose length in the transport direction is longer than the reverse path length D. (D3 <D). In this case, since D3> D2, the distance D2 to the separation roller 2 is D2 <D.

  In this example, the paper front end detection sensor 71 is disposed between the transport roller 4 and the separation roller 2.

  FIG. 6 is a block diagram illustrating a configuration example of a main part of the multifunction peripheral 200 of FIG. 5. The reading control unit controls the path selection unit 5 based on an input signal from the operation panel 21 and drives the conveyance roller. 70 is shown. The reading control unit 70 includes a roller rotation amount detection unit 72, a paper length determination unit 62, a conveyance control unit 63, and a roller driving unit 64. The paper length determination unit 62, the conveyance control unit 63, and the roller driving unit 64 perform the same operation as the reading control unit 60 in FIG.

  The roller rotation amount detection unit 72 detects the rotation amount of the length detection roller 35 based on the output of the paper front end detection sensor 71 and outputs the detection result to the paper length determination unit 62. Specifically, an operation of detecting the rotation amount after the front end of the document A1 being conveyed is detected by the paper front end detection sensor 71 at regular intervals is performed.

  Steps S201 to S208 in FIG. 7 are flowcharts showing an example of an operation at the time of double-sided reading in the multifunction device 200 in FIG. First, the conveyance control unit 63 controls the roller driving unit 64 to rotationally drive the conveyance roller (step S201).

  Next, when the front end of the document A1 being conveyed is detected by the paper front end detection sensor 71 (step S202), the roller rotation amount detection unit 72 detects the rotation amount of the length detection roller 35 after the front end is detected. The paper length determination unit 62 determines the length of the document A1 in the transport direction based on the rotation amount detection result (steps S203 and S204).

  At this time, the conveyance control unit 63 immediately stops the conveyance if the length in the conveyance direction of the original A1 being conveyed is longer than the upper limit, that is, the reversing path length D (step S205). S208).

  On the other hand, if the length in the transport direction does not exceed the upper limit, the transport of the document A1 is continued as it is, and the processing procedure from step S203 to step S205 is repeated until the length detection roller 35 stops rotating (step S205). S206).

  If the length detection roller 35 stops rotating without the length determination value exceeding the upper limit, the transport control unit 63 transports the document A1 to the scanner unit 24 as it is, and causes the scanner unit 24 to perform image reading. This process is terminated (step S207).

  According to the present embodiment, the length detection roller 35 that rotates in contact with the document A1 in the paper feed tray unit 11 has a distance D1 to the path selection unit 5 that is longer than the reverse path length D, and the front edge of the paper. Since the distance D3 to the detection sensor 71 is arranged at a position shorter than the reverse path length D, whether or not the original A1 is longer than the reverse path length D before the front end of the original A1 reaches the branch point of the path. Can always be determined correctly. Further, the length of the original A1 is determined based on the rotation amount of the length detection roller 35 after the front end of the original A1 is detected by the paper front end detection sensor 71 disposed between the path selection unit 5 and the separation roller 2. Therefore, the rotation of the length detection roller 35 while the document A1 is conveyed from the paper feed tray unit 11 to the paper front end detection sensor 71 can be ignored, and the length detection accuracy can be improved.

Embodiment 3 FIG.
In the first embodiment, an example in which the length of the document A1 in the conveyance direction is determined based on the rotation amount of the length detection roller 35 from the start of the document A1 delivery by the separation roller 2 has been described. On the other hand, in the present embodiment, a case will be described in which the length of the document A1 is determined based on the rotation continuation time of the length detection roller 35 from the start of sending of the document A1 by the separation roller 2.

  FIG. 8 is a block diagram illustrating a configuration example of an image reading apparatus according to the third embodiment of the present invention. The image reading apparatus controls the path selection unit 5 based on an input signal from the operation panel 21 and drives a conveyance roller. A control unit 80 is shown. The reading control unit 80 includes a roller rotation detection unit 81, a paper length determination unit 82, a timer 83, a conveyance control unit 63, and a roller driving unit 64. The conveyance control unit 63 and the roller driving unit 64 perform the same operation as the reading control unit 60 in FIG.

  The roller rotation detection unit 81 performs an operation of detecting the rotation of the length detection roller 35 and outputting the detection result to the paper length determination unit 82. Here, it is assumed that an operation for detecting whether or not the length detection roller 35 is rotating is performed at regular intervals.

  The timer 83 is a timing unit that is activated based on the sending of the document A1 by the separation roller 2 and measures the elapsed time from the start of sending.

  Based on the output of the timer 83, the paper length determination unit 82 determines the rotation continuation time of the length detection roller 35 from the start of delivery of the document A1 by the separation roller 2, and based on the rotation continuation time, the document A1. The operation of determining whether or not the length in the transport direction is longer than the reverse path length D is performed.

  Steps S301 to S308 in FIG. 9 are flowcharts showing an example of an operation at the time of duplex reading in the image reading apparatus in FIG. First, the conveyance control unit 63 controls the roller driving unit 64 to rotationally drive the conveyance roller (step S301).

  Next, if the rotation of the length detection roller 35 is not detected by the roller rotation detection unit 81 when the separation roller 2 starts to send the document A1, the paper length determination unit 82 is shorter than the distance D2. Is determined. At this time, the conveyance control unit 63 conveys the document A1 as it is to the scanner unit 24, causes the scanner unit 24 to perform image reading, and ends this processing (steps S302 and S307).

  On the other hand, if the rotation of the length detection roller 35 is detected, the timer 83 is started (steps S302 and S303), and the paper length determination unit 82 conveys the document A1 from the duration of the rotation of the length detection roller 35. The length of the direction is determined (step S304).

  At this time, if the length in the transport direction of the original A1 being transported is longer than the upper limit, that is, the reversing path length D, the transport control unit 63 immediately stops the transport and ends this processing (step S305, S308).

  On the other hand, if the length in the transport direction does not exceed the upper limit, the transport of the document A1 is continued as it is, and the processing procedure from step S304 to step S305 is repeated until the rotation of the length detection roller 35 stops (step S305). S306).

  If the length detection roller 35 stops rotating without the length determination value exceeding the upper limit, the transport control unit 63 transports the document A1 to the scanner unit 24 as it is, and causes the scanner unit 24 to perform image reading. This process is finished (step S307).

  According to the present embodiment, the length detection roller 35 that rotates in contact with the document A1 in the paper feed tray unit 11 has a distance D1 to the path selection unit 5 longer than the reverse path length D, and the separation roller. Since the distance D2 up to 2 is arranged at a position shorter than the reverse path length D, it is always determined whether or not the original A1 is longer than the reverse path length D before the front end of the original A1 reaches the branch point of the path. It can be judged correctly. Further, since the length of the original A1 is determined based on the rotation duration time of the length detection roller 35 after the separation roller 2 starts to send the original A1, the original A1 in the paper feed tray unit 11 is picked up. The rotation of the length detection roller 35 from when the separation is started to when the separation is started can be ignored, and the length detection accuracy can be improved. Further, whether or not the document A1 is shorter than the distance D2 between the separation roller 2 and the length detection roller 35 can be determined based on whether or not the length detection roller 35 is rotated when the document A1 starts to be sent.

Embodiment 4 FIG.
In the first embodiment, an example in which the length of the document A1 in the conveyance direction is determined based on the rotation amount of the length detection roller 35 from the start of the document A1 delivery by the separation roller 2 has been described. On the other hand, in the present embodiment, the length of the document A1 in the conveyance direction is determined based on the presence or absence of rotation of the length detection roller 35 when the front edge of the document A1 is detected by the paper front edge detection sensor 71. A case where it is determined whether or not it is longer than the length D will be described.

  FIG. 10 is a block diagram illustrating a configuration example of an image reading apparatus according to the fourth embodiment of the present invention. The image reading apparatus controls the path selection unit 5 based on an input signal from the operation panel 21 and drives the conveyance roller. A control unit 90 is shown. The reading control unit 90 includes a roller rotation detection unit 81, a paper length determination unit 91, a conveyance control unit 63, and a roller driving unit 64. The conveyance control unit 63 and the roller driving unit 64 perform the same operation as the reading control unit 60 in FIG.

  The roller rotation detection unit 81 performs an operation of detecting the rotation of the length detection roller 35 and outputting the detection result to the paper length determination unit 91. Here, it is assumed that an operation for detecting whether or not the length detection roller 35 is rotating is performed at regular intervals.

  The paper front end detection sensor 71 is disposed between the path selection unit 5 and the separation roller 2 at a position where the distance D3 to the length detection roller 35 is substantially the same as the reverse path length D.

  The paper length determination unit 91 reverses the length of the document A1 in the transport direction based on the presence or absence of rotation of the length detection roller 35 when the front edge of the document A1 being transported is detected by the paper front edge detection sensor 71. An operation for determining whether or not the length is longer than the path length D is performed.

  Steps S401 to S405 in FIG. 11 are flowcharts illustrating an example of an operation at the time of duplex reading in the image reading apparatus in FIG. First, the conveyance control unit 63 controls the roller driving unit 64 to rotationally drive the conveyance roller (step S401).

  Next, when the front end of the document A1 being conveyed is detected by the paper front end detection sensor 71 (step S402), the paper length determination unit 91 detects the rotation of the length detection roller 35 by the roller rotation detection unit 81. It is referred to whether or not (step S403).

  At this time, if the rotation of the length detection roller 35 is not detected, the paper length determination unit 91 determines that the length of the document A1 in the transport direction is shorter than the upper limit, that is, the reverse path length D. Then, the conveyance control unit 63 conveys the document A1 as it is to the scanner unit 24, causes the scanner unit 24 to perform image reading, and ends this processing (step S404).

  On the other hand, if the rotation of the length detection roller 35 is detected, the paper length determination unit 91 determines that the length of the document A1 in the transport direction is longer than the upper limit. And the conveyance control part 63 stops conveyance immediately, and complete | finishes this process (step S405).

  According to the present embodiment, the length detection roller 35 that rotates in contact with the document A1 in the paper feed tray unit 11 has a distance D1 to the path selection unit 5 that is longer than the reverse path length D, and the front edge of the paper. Since the distance D3 to the detection sensor 71 is arranged at a position substantially the same as the reverse path length D, is the original A1 longer than the reverse path length D before the front end of the original A1 reaches the branch point of the path? Whether or not can always be determined correctly. Further, the length of the original A1 is determined based on whether or not the length detection roller 35 is rotated when the front end of the original A1 is detected by the paper front end detection sensor 71 disposed between the path selection unit 5 and the separation roller 2. Since the determination is made, the rotation of the length detection roller 35 while the document A1 is conveyed from the paper feed tray unit 11 to the paper front end detection sensor 71 can be ignored, and the length detection accuracy can be improved.

  In the first to fourth embodiments, an example in which the conveyance of the original A1 is immediately stopped if it is determined that the length in the conveyance direction of the original A1 being conveyed is longer than the reverse path length D will be described. However, the present invention is not limited to this. For example, when it is determined that the length in the transport direction of the document A1 being transported is longer than the reverse path length D, an error is notified, or the transport path is switched from the double-sided path to the single-sided path, or the transport direction is changed. It may be reversed.

DESCRIPTION OF SYMBOLS 1 Pickup roller 2 Separation roller 3 Retard roller 4,41-50 Transport roller 5 Path selection part 10 ADF part 11 Paper feed tray part 12 Paper discharge tray part 20 Main body part 21 Operation panel 22 Paper feed cassette 23 Light source part 24 Scanner part 31 Document table 32 Document stopper 33 Guide plate 34 Discharge unit 35 Length detection roller 60 Reading control unit 61 Roller rotation amount detection unit 62 Paper length determination unit 63 Transport control unit 64 Roller drive unit 65 Rotation amount reset unit 71 Paper front edge detection sensor 100 , 200 MFP 210 ADF section A1 Documents B1, B2, B11, B21, B22

Claims (6)

A storage unit that stores the paper medium; a transport unit that transports the paper medium from the storage unit to the discharge unit; a reading unit that reads an image from the paper medium that is being transported; A reading path selection unit that is arranged at a branch point of a single-sided reading path for reading a surface and a double-sided reading path for reading both sides of the paper medium, and selects either the single-sided reading path or the double-sided reading path The double-sided reading path guides the paper medium from the storage section to the reading section via the branch point, and then again passes through the reversing path for reversing the paper medium. In the image reading apparatus that guides to
A separation unit for separating the paper medium in the storage unit and sending it to a conveyance path;
A follower roller disposed at a position where the distance to the branch point is longer than the path length of the reversing path, contacting the paper medium in the storage unit, and being rotated when the paper medium is fed by the separation unit;
A roller rotation amount detection unit for detecting the rotation amount of the follower roller;
A paper length determination unit that determines the length of the paper medium in the conveyance direction based on the rotation amount from the start of the paper medium by the separation unit;
An image reading apparatus comprising: a conveyance control unit that controls conveyance of the paper medium based on the determination result of the length.   The image reading apparatus according to claim 1, wherein a distance between the separation unit and the rotation roller is shorter than a path length of the reversing path. A storage unit that stores the paper medium; a transport unit that transports the paper medium from the storage unit to the discharge unit; a reading unit that reads an image from the paper medium that is being transported; A reading path selection unit that is arranged at a branch point of a single-sided reading path for reading a surface and a double-sided reading path for reading both sides of the paper medium, and selects either the single-sided reading path or the double-sided reading path The double-sided reading path guides the paper medium from the storage section to the reading section via the branch point, and then again passes through the reversing path for reversing the paper medium. In the image reading apparatus that guides to
A separation unit for separating the paper medium in the storage unit and sending it to a conveyance path;
A follower roller disposed at a position where the distance to the branch point is longer than the path length of the reversing path, contacting the paper medium in the storage unit, and being rotated when the paper medium is fed by the separation unit;
A roller rotation amount detection unit for detecting the rotation amount of the follower roller;
A paper front end detection sensor that is disposed between the reading path selection unit and the separation unit and detects a front end of the paper medium being conveyed;
A paper length determination unit that determines the length of the paper medium in the transport direction based on the rotation amount after the front end of the paper medium is detected;
A conveyance control unit that controls conveyance of the paper medium based on the determination result of the length,
An image reading apparatus, wherein a distance between the paper front end detection sensor and the follower roller is shorter than a path length of the reversing path. A storage unit that stores the paper medium; a transport unit that transports the paper medium from the storage unit to the discharge unit; a reading unit that reads an image from the paper medium that is being transported; A reading path selection unit that is arranged at a branch point of a single-sided reading path for reading a surface and a double-sided reading path for reading both sides of the paper medium, and selects either the single-sided reading path or the double-sided reading path The double-sided reading path guides the paper medium from the storage section to the reading section via the branch point, and then again passes through the reversing path for reversing the paper medium. In the image reading apparatus that guides to
A separation unit for separating the paper medium in the storage unit and sending it to a conveyance path;
The distance to the branch point is longer than the path length of the reversing path, the distance to the separation unit is arranged at a position shorter than the path length of the reversing path, is in contact with the paper medium in the storage unit, and A revolving roller that revolves when the paper medium is sent out by the separation unit;
A roller rotation detector for detecting the rotation of the follower roller;
Paper for determining whether or not the length in the transport direction of the paper medium is longer than the path length of the reversing path based on the rotation continuation time of the follower roller from the start of feeding of the paper medium by the separation unit A length determination unit;
An image reading apparatus comprising: a conveyance control unit that controls conveyance of the paper medium based on the determination result of the length. A storage unit that stores the paper medium; a transport unit that transports the paper medium from the storage unit to the discharge unit; a reading unit that reads an image from the paper medium that is being transported; A reading path selection unit that is arranged at a branch point of a single-sided reading path for reading a surface and a double-sided reading path for reading both sides of the paper medium, and selects either the single-sided reading path or the double-sided reading path The double-sided reading path guides the paper medium from the storage section to the reading section via the branch point, and then again passes through the reversing path for reversing the paper medium. In the image reading apparatus that guides to
A separation unit for separating the paper medium in the storage unit and sending it to a conveyance path;
A follower roller disposed at a position where the distance to the branch point is longer than the path length of the reversing path, contacting the paper medium in the storage unit, and being rotated when the paper medium is fed by the separation unit;
A roller rotation detector for detecting the rotation of the follower roller;
A paper between the reading path selection unit and the separation unit, which is disposed at a position where the distance to the follower roller is substantially the same as the path length of the reversing path, and detects the front end of the paper medium being conveyed A front end detection sensor;
A paper length for determining whether or not the length in the transport direction of the paper medium is longer than the path length of the reversing path based on the presence or absence of rotation of the follower roller when the front end of the paper medium is detected A determination unit;
An image reading apparatus comprising: a conveyance control unit that controls conveyance of the paper medium based on the determination result of the length.   6. The image reading apparatus according to claim 1, further comprising positioning means for positioning a position in a transport direction of front ends of the two or more paper media stacked in the accommodating portion.

Images