JP2010100430A - Image reading device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a partially missing read image, show-through, and document jam even when an excessively long document is set in a document tray, in an image reading device inverting the document with an inverting path and reading both faces. <P>SOLUTION: An image scanner device 20 includes a scanner unit 25, an inverting path 82, a tray document sensor 45, and a control part. The scanner unit 25 reads image information of the document at a reading position 90. The inverting path 82 conveys the document that passes the reading position 90 in a warped state, inverts its surface and back face, and guides it to the reading position 90. The tray document sensor 45 detects that the length in the conveyance direction of the document set in the document tray 23 is at and less than the path length from the reading position 90 to the reading position 90 after passing through the inverting path 82 and at and more than the predetermined length. When the tray document sensor 45 detects that the length of the document in the conveyance direction is at and more than the predetermined length, the control part prohibits both-face reading of the document. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image reading apparatus. Specifically, the present invention relates to an image reading apparatus that inverts an original by an inversion path and reads both sides of the original.

A reading unit that reads an image of the original, and after passing the original through the reading unit and reading one side, the original is reversed by moving the original along a curved reverse path; There is known an image reading apparatus configured to read a surface on the other side by passing the light. The image reading apparatus having this configuration can read both sides of a document with one reading unit. Patent Documents 1 and 2 disclose this type of image reading apparatus.
Japanese Patent No. 2828866 Japanese Patent No. 3007858

  By the way, in the image reading apparatus configured as described above, when reading both sides, it is necessary to start reading the second side after the first side is completely read. That is, in the image reading apparatus described above, the document is curved and conveyed in a U-turn shape by the reversing path. However, before the leading edge of the document reaches the reading position again for reading the second surface, the first reading is performed. When reading the surface, the trailing edge of the document must pass through the reading position. In this specification, the leading edge of the document refers to an end portion on the downstream side in the conveyance direction of the document, and the trailing edge of the document refers to an end portion on the upstream side in the conveyance direction of the document.

  However, if the length in the document transport direction is longer than the path length from the reading position via the reverse path to the reading position again, the original before the trailing edge of the original passes the reading position. Will return to the reading position. When such a long document is conveyed to the reverse path and double-sided reading is executed, the following problems occur.

  That is, since the original is hidden behind the original at the reading position, the read image on the first side or the second side is missing at the end of the original in the conveyance direction. In addition, since the leading edge and the trailing edge of the document overlap at the reading position, the content of the other surface is read through during the reading of one of the first surface and the second surface, so-called show-through. Degradation of image quality due to. Further, since the originals overlap in the vicinity of the reading position, the path switching member that prevents the reverse original from flowing backward to the path for conveying the original before the reverse cannot function well, causing jamming (original jam). The maintenance work is a burden on the user.

  In this regard, Patent Document 2 discloses an image reading apparatus configured to detect the length of a document and change the length of the reversing path according to the length of the document. According to this configuration, the above problem does not occur as long as the length of the reverse path can be changed according to the length of the document. However, since the configuration of Patent Document 2 requires a large configuration for changing the length of the reversing path, the manufacturing cost increases and the apparatus is enlarged. Further, even in the configuration of Patent Document 2, since there is a limit to the range in which the length of the reversing path can be increased, the above problem has occurred when attempting to read both sides of a document that is too long.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to read an image on both sides by reversing a document by a reversing path, even when an excessively long document is set on a document tray. Another object of the present invention is to provide an image reading apparatus capable of preventing the occurrence of chipped readings, show-through, and document jamming.

Means and effects for solving the problems

  The problems to be solved by the present invention are as described above. Next, means for solving the problems and the effects thereof will be described.

  According to an aspect of the present invention, an image reading apparatus having the following configuration is provided. That is, the image reading apparatus includes a document tray, a separation unit, a reading unit, an introduction path, a reversing path, a tray document sensor, and a control unit. The document tray can set stacked documents. The separation unit separates and conveys the documents stacked on the document tray one by one. The reading unit reads image information of the document. The introduction path guides the document so that a surface on one side of the document separated by the separation unit passes through a reading position of the reading unit. The reversing path reverses the document and guides it to the reading position of the reading unit so that the other surface of the document whose one surface is read through the introduction path is read. In the tray document sensor, the length of the document set in the document tray in the conveyance direction is not less than a predetermined length not more than a path length from the reading position to the reading position through the reverse path. Can be detected. When the tray document sensor detects that the length of the document in the conveyance direction is equal to or longer than the predetermined length, the control unit prohibits reading both sides of the document.

  As a result, when an original longer than the path length from the reading position to the reading position through the reverse path is set on the original tray, the length of the original is determined to be a predetermined length or more. It is possible to prohibit double-sided reading by detecting with a document sensor. Accordingly, since the long original can be prevented from being conveyed again from the reverse path to the reading position, show-through and jamming can be prevented in advance.

  The image reading apparatus is preferably configured as follows. That is, the image reading apparatus includes an operation unit capable of selecting whether to read both sides of the document. If the tray document sensor detects that the length of the document set on the document tray is not less than the predetermined length before the selection is performed by the operation unit, the control is performed. The section prohibits selection by the operation section to read both sides of the document.

  This prevents the user from selecting duplex scanning when a document whose length in the transport direction is a predetermined length or more is set on the document tray. Therefore, it is possible to prevent show-through and jamming, and it is possible for the user to know in advance that there is a document on the document tray that cannot be scanned on both sides. Can start.

  The image reading apparatus is preferably configured as follows. That is, the image reading apparatus includes an operation unit capable of selecting whether to read both sides of the document. The tray document sensor detects that the document is set on the document tray after the operation unit is selected to read both sides of the document, and the length of the document in the transport direction is equal to or longer than the predetermined length. Is detected, the control unit does not start reading the document.

  As a result, even when a document longer than a predetermined length is set on the document tray after the user selects duplex scanning, the document is conveyed again from the reverse path to the reading position. Therefore, the occurrence of show-through and jamming can be prevented.

  Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a copy facsimile multifunction peripheral (multifunction peripheral) 10 including an image scanner 20 as an image reading apparatus according to an embodiment of the present invention. FIG. 2 is a front sectional view showing a configuration of an automatic document feeder (auto document feeder, ADF) 21 provided in the image scanner device 20.

  As shown in FIG. 1, the copy facsimile multifunction peripheral 10 of this embodiment includes a main body 11, an operation panel 12, a paper feed cassette 13, and an image scanner device 20.

  The image scanner device 20 is configured to function as an auto document feed scanner, and includes an automatic document feeder 21. The operation panel 12 allows the user to instruct the multifunction device 10 about the discharge location of the original set on the image scanner device 20, the number of copies, the copy mode (single-sided copy, double-sided copy, consolidated copy, etc.), and the facsimile transmission destination. belongs to.

  The operation panel 12 includes a display unit such as a liquid crystal display, and is configured to display various items such as the original discharge location, the number of copies, a copy mode, and a facsimile transmission destination in a menu format. Further, the menu item can be selected by appropriately operating the operation panel 12 by the user, so that the user can intuitively instruct the multifunction device 10 while viewing the display on the display unit. Can be given.

  The ADF 21 is disposed above the main body 11, and an image forming apparatus 15 is built in the main body 11. Further, the main body 11 is provided with a transmission / reception unit (not shown) for transmitting image data via a communication line, and the transmission / reception unit is configured to enable facsimile communication. The paper feed cassette 13 is arranged on the lower side of the main body 11 and is configured so that the recording paper 100 can be sequentially supplied to the image forming apparatus 15.

  The ADF 21 includes a document tray 23 and a first discharge tray 24 provided below the document tray 23. In the ADF 21, a document conveyance path 70 that connects the document tray 23 and the first discharge tray 24 is formed. A scanner unit (reading unit) 25 is disposed in the document transport path 70, and the scanner unit 25 is configured to be able to read image information of the document 99 transported through the document transport path 70.

  Further, the ADF 21 includes a second discharge tray 26 connected to the document conveyance path 70 via a second discharge path 84 described later. The second discharge tray 26 is disposed on the opposite side of the document tray 23 with the scanner unit 25 interposed therebetween. When the image scanner device 20 according to the present embodiment reads one side of the original 99, the operation panel determines whether the original 99 after being read is to be discharged to the first discharge tray 24 or the second discharge tray 26. 12, the user can select.

  The ADF 21 is configured to set one or a plurality of documents 99 on the document tray 23 with the front side (one side) facing up and the back side (other side) facing down. It is. At an appropriate position of the document tray 23, a mark or the like indicating that the document should be set with the front side facing up is displayed by an appropriate method such as engraving or sticking. Further, the document tray 23 includes a tray document sensor 45 configured to be able to detect that the length of the set document 99 in the conveyance direction is equal to or longer than a predetermined length.

  In this configuration, the originals 99 set so that the front side faces upward are separated one by one and conveyed along the original conveyance path 70, and after passing through the reading position 90 of the scanner unit 25, It is discharged to the first discharge tray 24 or the second discharge tray 26. Details of the ADF 21 will be described later.

  As described above, the image forming apparatus 15 is disposed inside the main body 11. As shown in FIG. 1, the image forming apparatus 15 includes an image forming unit 50, a fixing device 51, a switchback mechanism 59, and a discharge unit 53 as main components.

  The paper feed cassette 13 is disposed at the lower part of the main body 11 and is configured to be able to be pulled out to the front side of the apparatus (the front side of the paper in FIG. 1). An image forming unit 50, a fixing device 51, a switchback mechanism 59, and a discharge unit 53 are disposed above the paper feed cassette 13.

  The image forming apparatus 15 is provided with an unillustrated control unit for controlling the image forming unit 50, rollers of each unit described later, a switchback mechanism 59, and the like. The switchback mechanism 59 includes a recording paper discharge roller 62, a switch unit 52, and a switchback path 57 as main components.

  Inside the main body 11, a recording paper transport path 56 for transporting the recording paper 100 from the paper feed cassette 13 to the tray-shaped discharge unit 53 is formed. The recording paper transport path 56 is connected from the paper feed cassette 13 to the discharge unit 53 so as to be substantially C-shaped when viewed from the front shown in FIG.

  The recording paper transport path 56 is connected to the switchback path 57 for enabling double-sided printing. One end of the switchback path 57 is connected to the recording paper transport path 56 on the downstream side of the fixing device 51, and a switch section 52 is disposed in the vicinity of the connection portion. The other end of the switchback path 57 is connected to the recording paper transport path 56 at a location downstream from the paper feed section 55 and upstream from the image forming section 50.

  As shown in the front view of FIG. 1, the switchback path 57 is combined with a part of the recording paper transport path 56 to form a substantially U-turn path. The folded path is configured so that the recording paper 100 once passed through the image forming unit 50 can be reversed and guided to the image forming unit 50 again. Printing is realized.

  Hereinafter, a detailed configuration of each part of the image forming apparatus 15 will be described. First, the configuration of each unit arranged in the recording paper transport path 56 will be described in order from the upstream side to the downstream side.

  A flapper 54 for stacking the recording paper 100 is rotatably disposed at the bottom of the paper feed cassette 13. The flapper 54 is biased upward by a spring (not shown). In addition, above the flapper 54, a paper feed unit 55 including a paper feed roller and a paper feed pad is disposed. The paper feed roller of the paper feed unit 55 is configured to come into contact with the uppermost recording paper 100 stacked on the flapper 54.

  A pair of recording paper transport rollers 61 are arranged on the downstream side of the paper feed cassette 13. The recording paper transport roller 61 is configured to feed the recording paper 100 along the recording paper transport path 56 to the downstream image forming unit 50 while nipping the recording paper 100.

  The recording paper conveyance path 56 is formed to be curved in a C shape as described above, and the image forming unit 50 is disposed on the inner peripheral side thereof so as to face the recording paper conveyance path 56. The image forming unit 50 includes, for example, a photosensitive drum, a charger, an exposure head, a developing device, and a transfer roller. The image forming unit 50 can transfer (form) a toner image corresponding to the image information to the recording paper 100 conveyed by the recording paper conveyance roller 61. The recording paper 100 on which the toner image is formed by the image forming unit 50 is sent along the recording paper conveyance path 56 to the fixing device 51 on the downstream side.

  The fixing device 51 includes a heat roller that is rotationally driven, and a press roller that is disposed to face the heat roller. The fixing device 51 is configured to melt the toner of the toner image transferred to the recording paper 100 by the image forming unit 50 by the heat of the high-temperature heat roller and the pressure by the press roller and fix the toner on the recording paper 100. Has been.

  As described above, the switch portion 52 including a claw portion configured to be rotatable is disposed at a connection portion between the recording paper conveyance path 56 and the switchback path 57 on the downstream side of the fixing device 51. Yes. The recording paper 100 can be guided to the switchback path 57 by the rotation operation of the claw portion of the switch portion 52. In addition, a switchback sensor 65 is disposed at a position slightly downstream of the connection portion with the switchback path 57 in the recording paper transport path 56.

  A recording paper discharge roller 62 is disposed further downstream of the switchback sensor 65. The recording paper discharge roller 62 is configured to be able to switch the rotation direction between the forward direction (clockwise direction in FIG. 1) and the reverse direction (counterclockwise direction in FIG. 1).

  A discharge unit 53 is connected to the end of the recording paper transport path 56 further downstream of the recording paper discharge roller 62. The recording paper 100 on which the image is formed by the image forming unit 50 passes through the curved recording paper conveyance path 56 and is discharged to the discharge unit 53 so that the surface on which the image is formed faces downward. (Face-down paper discharge).

  Note that recording paper transport rollers 63 and 64 are disposed in the switchback path 57, and the recording paper 100 sent to the switchback path 57 is directed to a location upstream of the recording paper transport roller 61. It is configured so that it can be conveyed.

  With the above configuration, when the operation panel 12 or the like is instructed to perform single-sided printing (for example, a mode for performing single-sided copying), the image forming apparatus 15 operates as follows. That is, when the paper feeding unit 55 is driven at the start of printing, the uppermost recording paper 100 set in the paper feeding cassette 13 is separated and picked up by the paper feeding roller, and the recording paper transport path Sent to 56. Then, the recording paper 100 is sent downstream along the recording paper conveyance path 56, and a desired toner image is formed when passing through the image forming unit 50. Thereafter, the recording paper 100 passes through the fixing device 51, whereby the toner image is fixed on the recording paper 100. Thereafter, the recording paper 100 is discharged by the recording paper discharge roller 62 that is rotationally driven in the forward direction to the discharge portion 53 with the surface on which the image is formed facing downward.

  On the other hand, when double-sided printing (for example, double-sided copying) is instructed on the operation panel 12 or the like, similarly, one sheet of recording paper 100 is picked up from the paper feed cassette 13, and the image forming unit 50 is moved along the recording paper conveyance path 56. And a toner image is formed. However, in the multi-function device 10 (image forming apparatus 15) of the present embodiment, in the case of double-sided printing in which images are formed on the front and back of one recording paper 100, the recording paper 100 passes through the image forming unit 50 for the first time. In some cases, a toner image on the back side (second side) is first formed.

  The recording paper 100 on which the image on the back side is formed passes through the fixing device 51 and is further conveyed downstream along the recording paper conveyance path 56. The recording paper 100 is conveyed while being nipped by the recording paper discharge roller 62, and eventually the rear end passes through the switchback sensor 65. The switchback sensor 65 that detects the passage of the trailing edge of the recording paper 100 sends a detection signal to the control unit. The control unit that has received this signal drives the recording paper discharge roller 62 in the reverse direction and operates the switch unit 52 at an appropriate timing so as to guide the recording paper 100 to the switchback path 57. As a result, the recording paper 100 is fed into the switchback path 57.

  In the switchback path 57, the recording paper 100 is transported downstream by driving the recording paper transport rollers 63 and 64, and is introduced into the recording paper transport path 56. Further, the recording paper 100 is conveyed downstream by the recording paper conveying roller 61 and passes through the image forming unit 50 again. Since the recording paper 100 is reversed by passing through the switchback path 57, the surface opposite to the surface on which the image is formed when passing the first image forming unit 50 is in the image forming unit 50. You will face each other. Then, this time (when the recording paper 100 passes for the second time), the image forming unit 50 forms a toner image on the front surface (first surface) on the recording paper 100.

  The recording paper 100 on which the image on the front side is formed passes through the fixing device 51 and is further conveyed downstream along the recording paper conveyance path 56. The recording paper discharge roller 62 is switched to rotate in the forward direction again at an appropriate timing after the recording paper 100 is fed into the switchback path 57 by the reverse rotation as described above. Accordingly, the recording paper 100 for which double-sided printing has been completed is discharged by the recording paper discharge roller 62 to the discharge unit 53 with the front side surface (first surface) facing down.

  Next, a detailed configuration of the ADF 21 will be described with reference to FIG. The image scanner device 20 includes an ADF 21 for conveying the document 99, and a scanner unit 25 for reading the document 99 is disposed inside the ADF 21. In addition, a curved document conveyance path 70 that connects the document tray 23 and the first discharge tray 24 is configured inside the ADF 21 so as to pass the reading position 90 of the scanner unit 25.

  The scanner unit 25 will be described. The scanner unit 25 is configured as a reduction optical system type scanner unit including a light source, a reflection mirror, a condensing lens, a CCD, and the like, and is disposed in the upper part of the ADF 21. With this configuration, the scanner unit 25 irradiates light from the light source onto the document conveyed through the document conveyance path 70. Reflected light from the original is guided to the CCD and imaged, and the CCD outputs an electrical signal corresponding to the original. This signal is sent to the image forming unit 50 after appropriate conversion processing and printed, or transmitted to another facsimile apparatus via the communication line by the transmission / reception unit.

  Next, the document conveyance path 70 will be described. The document transport path 70 is an introduction path 80 for guiding the document 99 to the reading position 90, a reversing path 82 for inverting the document 99 and guiding it again to the reading position 90, and for discharging the read document 99. The first discharge path 83, the second discharge path 84, and the single-sided path 81 are provided. Hereinafter, these paths constituting the document conveyance path 70 will be described.

  As shown in FIG. 2, the introduction path 80 is formed in a straight line extending substantially horizontally in a direction away from the document tray 23 from a position where the document 99 on the document tray 23 is supplied into the ADF 21. In the introduction path 80, a pickup roller 31, a separation unit 32, a document length detection sensor 41, a triple roller 33, a first read sensor 42, a scanner unit 25, and a conveyance roller 34 are arranged. Below, the structure of each part arrange | positioned on the path | route of the introductory path | pass 80 is demonstrated from the upstream side to the downstream side.

  In the vicinity of the upstream end portion of the introduction path 80, a pickup roller (feeding portion) 31 and a separation portion 32 are disposed. The separation unit 32 includes a separation roller and a counter roller disposed opposite to the separation roller.

  The pickup roller 31 is configured to be rotatable about the rotation axis of the separation roller. When the ADF 21 is not operating, the pickup roller 31 is held at an upper position indicated by a two-dot chain line. On the other hand, when the original 99 is fed, the pickup roller 31 is rotated downward to come into contact with the end of the original 99 on the uppermost layer among the originals set on the original tray 23 (shown in FIG. 2). Solid line position). When the pickup roller 31 rotates in this state, the uppermost document 99 on the document tray 23 is sent to the separation unit 32.

  The document 99 sent to the separation unit 32 by driving the pickup roller 31 is nipped between the separation roller and the opposing roller of the separation unit 32. The document 99 is separated one by one by a separation roller and a counter roller that are driven to rotate, and is sent downstream.

  The document length detection sensor 41 is for detecting the length of the document 99 conveyed through the introduction path 80 and is electrically connected to a control unit (not shown) that controls each part of the ADF 21. The control unit is configured to be able to control each part (such as a conveyance roller) of the ADF 21 based on the detection signal of the document length detection sensor 41. For example, the control unit detects the position of the trailing edge of the document 99 currently being conveyed by the document length detection sensor 41, determines the transfer timing of the subsequent document 99 based on this detection timing, and picks up the roller 31. The driving of the separation unit 32 and the like is controlled. The control unit includes a CPU as a calculation unit, a memory as a storage unit, and the like.

  The triple roller 33 includes a driving roller disposed on the center side and two driven rollers disposed so as to sandwich the driving roller. The drive roller is arranged in such a manner that the upper side is sandwiched between the introduction path 80 and the lower side is sandwiched between first discharge paths 83 described later. One of the two driven rollers is disposed to face the driving roller with the introduction path 80 interposed therebetween, and the other is disposed to face the driving roller with the first discharge path 83 interposed therebetween. With this configuration, by driving and rotating the driving roller disposed in the center, two driven rollers adjacent to the driving roller can be simultaneously rotated. Therefore, the number of parts can be reduced and the limited space in the ADF 21 can be used effectively.

  A first lead sensor 42 is disposed on the downstream side of the triple roller 33. The first read sensor 42 is disposed on the upstream side of the reading position 90 of the scanner unit 25, and reads the document 99 by the scanner unit 25 based on the timing when the first lead sensor 42 detects the top of the document 99. Timing is determined. The first read sensor 42 allows the scanner unit 25 to appropriately read the document 99 passing through the introduction path 80 at the reading position 90.

  The scanner unit 25 is arranged above the introduction path 80 and is configured to read the upper surface of the document 99 by a reading surface (not shown) arranged to face the lower side. As described above, since the reading surface faces the path (introduction path 80) of the document 99 from the upper side, paper dust and dust generated by the conveyance of the document 99 and the like are difficult to adhere to the reading surface. . Further, since the document 99 is set so that the surface of the document 99 faces upward, the document 99 that is guided from the document tray 23 to the linear introduction path 80 and passes the reading position 90 is The front side surface is read by the scanner unit 25.

  On the downstream side of the scanner unit 25, a transport roller 34 composed of a pair of rollers is disposed. By driving the transport roller 34, the document 99 whose front side has been read at the reading position 90 is further transported downstream along the introduction path 80.

  On the downstream side of the conveying roller 34, a three-way straight path branch is connected to the downstream end of the introduction path 80, the upstream end of the second discharge path 84, and the upstream end of the reverse path 82. A portion 92 is formed. The straight path branching unit 92 is provided with a straight path switching device (path switching unit) 96. The straight path switching device 96 includes a rotating member formed in a claw shape and a solenoid 71 as an actuator. The straight path switching device 96 is configured to be able to distribute the document 99 conveyed from the introduction path 80 to the reverse path 82 or the second discharge path 84 by rotating the rotating member by the solenoid 71. The switching of the path between the reversing path 82 and the second discharge path 84 is performed based on the designation of the discharge location on the operation panel 12 or the like.

  Next, the second discharge path 84 will be described. The second discharge path 84 is formed in a straight line extending substantially horizontally from the straight path branch portion 92, and connects the downstream end portion of the introduction path 80 and the second discharge tray 26. A transport roller 38 composed of a pair of rollers is disposed on the path of the second discharge path 84, and the document guided to the second discharge path 84 by driving the transport roller 38. 99 is discharged to the second discharge tray 26.

  Next, the reverse path 82 will be described. The reversing path 82 is configured in a substantially U-turn shape so that the document 99 can be reversed by the folding portion 94. Specifically, the reversing path 82 extends downward from the position of the straight path branching portion 92 in a direction away from the document tray 23, and then is further bent in a direction approaching the document tray 23 to form a folded portion 94. . The reverse path 82 extends obliquely upward from the folding portion 94 toward the reading position 90 and then bends in a substantially horizontal direction at a position near the reading position 90 to join a part of the introduction path 80 near the reading position 90. (Or close). Subsequently, the reversing path 82 is configured to bend obliquely downward so as to be separated from the introduction path 80 after passing the reading position 90, extend linearly, and be connected to the discharge path connecting portion 93.

  Conveying rollers 35 and 36 are arranged on the reverse path 82. In addition, a second read sensor 43 is disposed on the downstream side of these conveying rollers 35 and 36 and on the upstream side of the reading position 90. Based on the timing at which the second read sensor 43 detects the top of the document 99, the timing at which the scanner 99 reads the document 99 on the reverse path 82 is determined.

  The document 99 guided to the reversing path 82 is guided to the reading position 90 in a state where the up and down direction of the document 99 is reversed by driving of the conveying rollers 35 and 36 by the folding unit 94. Become. Therefore, when passing the reading position 90 for the second time, the surface on the back side of the document 99 is read. The transport direction when the document 99 transported along the reverse path 82 passes the reading position 90 is the transport direction when the document 99 transported along the introduction path 80 passes the reading position 90. It is reversed.

  Note that a flapper valve (route switching member, entry) is provided between the first lead sensor 42 and the scanner unit 25 to prevent the document 99 guided along the reverse path 82 from entering the introduction path 80 by mistake. Prevention member) 46 is arranged. The flapper valve 46 is configured to act as a kind of check valve against the flow of the document. For the document 99 conveyed through the introduction path 80 from the upstream side to the downstream side, the flapper valve 46 is The introduction path 80 is released in such a manner that it is pushed away by the document 99. On the other hand, for the document 99 conveyed from the reversing path 82, the flapper valve 46 prevents the document 99 from entering the introduction path 80 and simultaneously guides the document 99 downstream of the reversing path 82. The flapper valve 46 can be constituted by an appropriate member such as a plate member and a film member.

  The downstream end of the reversing path 82 is connected to the upstream end of the first discharge path 83 via the discharge path connecting portion 93. The first discharge path 83 is formed in a polygonal line shape, extends linearly downward from the discharge path connecting portion 93 and then bends in the horizontal direction and is connected to the first discharge tray 24. On the path of the first discharge path 83, the triple roller 33 and the transport roller 37 are arranged. With this configuration, when the triple roller 33 and the conveyance roller 37 are driven, the document 99 guided to the first discharge path 83 is discharged to the first discharge tray 24.

  A single-sided path branching portion 91 for branching from the reverse path 82 to the single-sided path 81 is formed on the path of the reverse path 82 and downstream of the turn-back portion 94 and upstream of the reading position 90. . A single-sided path switching device 95 is disposed in the single-sided path branching portion 91, and the single-sided path switching device 95 includes a rotating member formed in a claw shape and a solenoid 72 as an actuator. The single-sided path switching device 95 switches between switching the path of the document 99 that has been transported through the reverse path 82 to the single-sided path 81 or passing the reverse path 82 as it is by rotating the rotating member by the solenoid 72. It is configured to be possible. This path switching is controlled based on designation of single-sided copying and double-sided copying on the operation panel 12.

  Next, the single-sided path 81 will be described. The single-sided path 81 is formed in a straight line extending in a direction approaching the document tray 23 while being slightly inclined upward from the single-sided path branching portion 91, and is connected to the single-sided path branching portion 91 and the discharge path below the inversion path 82. The unit 93 is connected.

  Further, an unillustrated shielding member for appropriately reading the scanner unit 25 is disposed above the single-sided path 81 and below the reversing path 82 in the vicinity of the reading position 90. This shielding member is configured as a film-like member, for example, and is arranged so as to cover the range of the reading position 90 of the scanner unit 25. With this shielding member, it is possible to shield the document 99 passing through the single-sided path 81 from being read by the scanner unit 25.

  With this configuration, the document 99 guided to the single-sided path 81 by driving the conveyance roller 36 passes under the reversing path 82 so as to avoid the reading position 90, and passes through the discharge path connecting portion 93. Guided to one discharge path 83.

  Next, a case where the document 99 is conveyed by the ADF 21 configured as described above to read only one side (front side) and the read document 99 is discharged to the first discharge tray 24 will be described with reference to FIGS. explain. FIG. 3 is a front sectional view showing a state where the front side surface of the document 99 guided to the introduction path 80 is read in the case of single-sided reading. FIG. 4 is a front sectional view showing a state in which the document 99 is guided to the first discharge path 83 via the single-sided path 81.

  The user operates the operation panel 12 of the multifunction device 10 to specify the single-sided copy mode as the copy mode, specify the first discharge tray 24 as the discharge location of the document 99, and set the document 99 on the document tray 23. Assume that a copy start is instructed. As a result, single-sided reading of the document 99 by the image scanner device 20 is started.

  With the start of this single-sided reading, the pickup roller 31 and separation unit 32 of the ADF 21 are driven, and the solenoid 71 of the straight path switching device 96 is controlled so as to switch the path of the document 99 to the reverse path 82 side. Further, the solenoid 72 of the single-sided path switching device 95 is controlled so that the path of the document 99 is switched to the single-sided path 81 side.

  As shown in FIG. 3, the document 99 introduced into the introduction path 80 by the pickup roller 31 and the separation unit 32 is guided to the reading position 90 by driving the triple roller 33 and the like, and the upper surface of the document 99 is read. . At this time, the document 99 advances through the introduction path 80 so as to push away the flapper valve 46 as shown in FIG. Since the front side of the original 99 is set on the original tray 23 so that the front side faces upward, the front side of the original 99 is read in the state shown in FIG.

  As shown in FIG. 3, the document 99 whose front side is read at the reading position 90 on the introduction path 80 is guided to the reversing path 82 side by the straight path switching unit 96 in the straight path branching section 92. Since the document 99 guided by the reversing path 82 is reversed by passing through the folding portion 94, the top and bottom directions of the document 99 are reversed, and the front side surface of the document 99 is directed downward.

  As shown in FIG. 4, the document 99 that has been transported through the folding unit 94 by driving the transport rollers 35 and 36 is guided to the single-sided path 81 side by the single-sided path switching unit 95 as shown in FIG. The passage of the reading position 90 is avoided. Thereafter, the document 99 is guided from the single-sided path 81 to the first discharge path 83 via the discharge path connecting portion 93. Thus, the original 99 after reading the front side surface is discharged without passing through the reading position 90. Therefore, even if the subsequent original 99 is brought into the introduction path 80 before the original 99 is discharged, In reading the succeeding document 99, the preceding document 99 does not get in the way.

  The document 99 guided to the first discharge path 83 is discharged to the document tray 23. Since the original 99 is reversed by making a U-turn at the turn-back portion 94, the originals 99 that have been read are sequentially stacked on the first discharge tray 24 with the front side facing down (see FIG. Face-down paper discharge). As a result, the document 99 can be discharged so as not to change the page order when it is set on the document tray 23, so that it is not necessary for the user to rearrange the read document 99 after collection, thereby realizing good workability. Has been.

  In this description, since the copy of the document 99 is instructed, the image information of the read document 99 is sent to the image forming unit 50 and sequentially printed. When facsimile communication is instructed, the single-sided reading of the original 99 is performed in the same manner as described above, and the image information of the read original 99 is transmitted to the counterpart facsimile machine.

  Next, a case where the document 99 is discharged to the second discharge tray 26 will be described with reference to FIG. FIG. 5 is a front sectional view showing a state in which the document 99 is discharged to the second discharge tray 26 via the second discharge path 84.

  The user operates the operation panel 12 of the multifunction device 10 to specify the single-sided copy mode as the copy mode, specify the second discharge tray 26 as the discharge location of the document 99, and set the document 99 on the document tray 23. Assume that a copy start is instructed. As a result, single-sided reading of the document 99 by the image scanner device 20 is started.

  When this one-sided reading is started, the pickup roller 31 and the separation unit 32 of the ADF 21 are driven as in the case of the one-sided reading in which the first discharge tray 24 is designated as the discharge location. At the same time, the solenoid 71 of the straight path switching device 96 is controlled so that the path of the document 99 is switched to the second discharge path 84 side this time.

  The document 99 separated by the separation unit 32 is guided to the reading position 90 by driving the triple roller 33 and the like, and the upper surface (front surface) of the document 99 is read. Thereafter, as shown in FIG. 5, the document 99 is guided to the second discharge path 84 side by the straight path switching device 96 in the straight path branching section 92. The document 99 guided to the second discharge path 84 side is discharged to the second discharge tray 26 by driving the conveyance roller 38.

  In the present embodiment, the transport path of the document 99 that connects the document tray 23 to the second discharge tray 26 is configured by an introduction path 80 and a second discharge path 84 that are formed in a straight line. Therefore, by controlling the original 99 to be discharged to the second discharge tray 26, the original 99 can be conveyed in a substantially straight line, and the reading operation can be completed without bending. As a result, even for a document (thick paper, plate, etc.) that is difficult to bend, by specifying the second discharge tray 26 as a discharge location on the operation panel 12, the reading operation can be performed without damaging the document. .

  Next, a case where both sides of the document 99 are read will be described with reference to FIGS. FIG. 6 is a front sectional view showing a state in which the front side surface of the document 99 guided to the introduction path 80 is read in the case of double-sided reading. FIG. 7 is a front cross-sectional view showing a state in which the reverse side surface of the document 99 guided by the reverse path 82 is read.

  It is assumed that the user operates the operation panel 12 of the multifunction machine 10 to designate the double-sided copy mode as the copy mode, sets the document 99 on the document tray 23, and instructs the copy start. As a result, double-sided reading of the document 99 by the image scanner device 20 is started. In the present embodiment, when the user designates double-sided reading (for example, double-sided copy mode), the first discharge tray 24 is automatically set as the discharge location of the document 99.

  When the double-sided reading is started, the pickup roller 31 and the separation unit 32 are driven as in the case of the single-sided reading described above. At the same time, the solenoid 71 of the straight path switching device 96 is controlled so as to switch the path of the document 99 to the reverse path 82 side. In the single-sided path branching unit 91, the solenoid 72 of the single-sided path switching device 95 is controlled so that the document 99 passes through the reverse path 82 as it is.

  When the document 99 is guided to the introduction path 80 by the pickup roller 31 and the separation unit 32, the document 99 advances so as to push away the flapper valve 46, and first, the front side surface of the document 99 is read at the reading position 90. Thereafter, the document 99 is guided to the reversing path 82 side in the straight path branching section 92 as shown in FIG. The document 99 is reversed by passing through the turn-back portion 94 in the reversing path 82, and the front side surface of the document 99 is directed downward. Then, the document 99 is conveyed to the single-sided path branching unit 91 by driving the conveying rollers 35 and 36.

  As shown in FIG. 7, the document 99 is guided by the single-sided path switching device 95 to the downstream side of the reverse path 82 (not the single-sided path 81) in the single-sided path branching portion 91 and reaches the reading position 90. Since the document 99 is inverted by the folding portion 94, the back side surface is facing upward in the state shown in FIG. Accordingly, at the reading position 90, the surface on the back side of the document 99 is read.

  As shown in FIG. 7, the flapper valve 46 is disposed so as to block the introduction path 80 on the downstream side of the reading position 90 in the reverse path 82, and the document 99 enters the introduction path 80 from the reverse path 82. Is prevented. As a result, the document 99 is guided further downstream of the reversing path 82 and conveyed to the first discharge tray 24 via the discharge path connecting portion 93 and the first discharge path 83.

  As in the case of single-sided reading described above, the document 99 is discharged to the first discharge tray 24 with the front side facing down (face-down discharge). Therefore, since the documents 99 set on the document tray 23 can be discharged to the first discharge tray 24 without changing the order, the work load such as rearrangement of the collected documents 99 is reduced.

  In this way, the originals 99 set on the original tray 23 are separated one by one, and both sides thereof are sequentially read by the scanner unit 25. The control unit of the ADF 21 controls the pickup roller 31 and the pickup roller 31 so that the subsequent document does not reach the reading position 90 on the introduction path 80 while the document 99 passes the reading position 90 of the reverse path 82. The driving timing of the separation unit 32 is appropriately controlled. Thereby, it is possible to prevent the documents 99 from colliding with each other in the vicinity of the reading position 90.

  By the way, since documents 99 of various sizes can be set on the document tray 23, depending on the situation, a document that is longer than the path length from the reading position 90 to the reading position 90 through the reverse path 82 again. There may be a case where (a document having a long length in the conveyance direction) is set. Hereinafter, control when reading such a document will be described.

  In the following description, a path from the reading position 90 to the reading position 90 through the reverse path 82 is referred to as a “turn path”, and an original longer than the path length of the turn path is simply referred to as a “long original”. Sometimes called. “Document length” means the length of the document in the transport direction. When the document is simply “long”, it means that the document is long in the transport direction.

  First, a problem that arises when such a long document is read on both sides will be described in detail with reference to FIG. FIG. 8 shows a state where it is assumed that the ADF 21 conveys the long original 101 along the reverse path 82 and reads both sides (forcibly).

  When this long document 101 is conveyed from the document tray 23 through the introduction path 80, the document 101 advances so as to push away the flapper valve 46, and the front side surface is read at the reading position 90. Thereafter, as shown in FIG. 8, the long original 101 is guided to the reverse path 82 side in the straight path branching section 92. Then, the long original 101 is reversed by passing through the folding portion 94 in the reversing path 82, and reaches the reading position 90 again via the single-sided path branching portion 91.

  As shown in FIG. 8, when the leading edge of the long document 101 reaches the reading position 90 through the reverse path 82, the trailing edge of the long document 101 has not yet passed through the reading position 90. (In other words, reading of the front side surface is not completed). For this reason, since the back surface cannot be read from the front end portion of the document 101, the read image on the back surface is chipped. In addition, the leading edge and the trailing edge of the long document 101 overlap each other at the reading position 90, and the contents of the back side surface are read through while reading the front side surface of the long document 101 (show-through).

  In addition, the document 101 may be longer than the path length from the position of the flapper valve 46 through the reverse path 82 to the position of the flapper valve 46 again. In this case, at the position of the flapper valve 46. Jam is likely to occur. That is, when such a long document is conveyed, even if the leading edge of the document 101 reaches the position of the flapper valve 46, as shown in FIG. The position has not been removed. In this state, the flapper valve 46 is pushed away by the rear end portion of the long document 101, so that the introduction path 80 cannot be blocked. Therefore, the flapper valve 46 cannot prevent the original 101 from entering (reversely flowing) from the reverse path 82 toward the introduction path 80. As a result, the leading edge of the long document 101 is not properly guided to the first discharge path 83, and document jam occurs.

  Considering the above points, in the present embodiment, the tray document sensor 45 disposed on the document tray 23 detects whether or not the length of the document set on the document tray 23 is equal to or longer than a predetermined length. It is configured as follows. The predetermined length can be set to be equal to the path length of the turn path, but with a slight margin, the predetermined length is shorter than the path length, that is, the predetermined length is turn. The route length may be obtained by subtracting the margin.

  Specifically, as shown in FIGS. 2 to 8, the tray document sensor 45 is disposed so as to be embedded in the document tray 23. The tray document sensor 45 is, for example, a non-contact sensor, and can detect whether or not a document exists at a position where the tray document sensor 45 is disposed. The tray document sensor 45 is electrically connected to the control unit, and is configured to transmit the detection result to the control unit. The tray document sensor 45 is disposed at a position upstream from the position corresponding to the leading edge of the document set on the document tray 23 by the predetermined length.

  With the above configuration, when the length of the document set on the document tray 23 is shorter than a predetermined length (for example, in the case of FIGS. 2 to 7), the document is not detected by the tray document sensor 45. On the other hand, when the length of the document set on the document tray 23 is equal to or longer than the predetermined length (as shown in FIG. 8), the document is detected by the tray document sensor 45. Further, as described above, the predetermined length is set to the same length as the route length of the turn route or a length shorter than the route length. Therefore, when the tray document sensor 45 does not detect a document, it can be determined that the length of the document set on the document tray 23 is shorter than the turn path length.

  As is apparent from FIGS. 2 to 8, the path length of the turn path (from the reading position 90 to the reading position 90) is determined again from the position of the flapper valve 46 through the reverse path 82. It is shorter than the path length up to 46 position. Therefore, when the tray document sensor 45 does not detect the document, the length of the document is shorter than the path length from the position of the flapper valve 46 to the position of the flapper valve 46 again through the reverse path 82. Can do.

  Accordingly, when the tray document sensor 45 does not detect the document, the situation as shown in FIG. 8 cannot occur, and there is a possibility that the image is missing at the time of reading, show-through, or jammed at the flapper valve 46. It can be said that there is no. Therefore, in this case, it is possible to read both sides of the original set on the original tray 23 as usual.

  On the other hand, when the tray document sensor 45 detects a document, the length of the document set on the document tray 23 is equal to or longer than a predetermined length. It can be said that the nature is high. Therefore, in this embodiment, when the tray document sensor 45 detects a document, the control unit is configured to prohibit reading of both sides of the document. Specifically, it is as follows.

  First, a case will be described in which a document is set on the document tray 23 without instructing the multifunction machine 10 in advance whether to perform single-sided reading or double-sided reading. In this case, the control unit that has detected that a document has been set by an appropriate sensor checks the state of the tray document sensor 45. When the length of the set original is equal to or longer than the predetermined length, the original is detected by the tray original sensor 45, and the tray original sensor 45 transmits an appropriate signal to the control unit. When receiving the signal from the tray document sensor 45, the control unit is configured to transmit an instruction to the operation panel 12 to shift to the double-sided reading prohibit mode.

  The operation panel 12 is configured to prevent the user from instructing double-sided reading of a document when the mode is shifted to the double-sided reading prohibition mode in accordance with an instruction from the control unit. For example, the operation panel 12 can display a single-sided copy mode / double-sided copy mode selection menu on the display unit according to a user's appropriate operation, but the duplex copy mode item is grayed out in the double-sided reading inhibition mode. . In this state, even if the user performs an operation for selecting the duplex copy mode, the operation is not accepted. Along with this gray-out display, a message indicating that double-sided scanning cannot be performed because the set document is too long may be displayed on the display unit.

  Note that the above-described problems of missing, show-through, and jamming of the read image are problems that occur only when double-sided scanning of a long document. The mode can be selected as usual.

  Next, a case will be described in which a document whose length is equal to or longer than a predetermined length is set on the document tray 23 after selecting that double-sided scanning is to be performed (for example, duplex copying mode). In other words, the multifunction machine 10 of the present embodiment is configured so that either the single-sided copy mode or the double-sided copy mode can be selected in advance by the operation panel 12 even when no document is set. Then, it is assumed that the user operates the operation panel 12 and selects the double-sided copy mode before setting the document on the document tray 23 by using this fact.

  After selecting the double-sided copy mode as described above, the user sets a document on the document tray 23 and operates the operation panel 12 to instruct reading. By this operation, the operation panel 12 transmits an appropriate signal to the control unit, and the control unit that receives the signal checks the state of the tray document sensor 45. When the tray document sensor 45 does not detect the document (when the length of the document set on the document tray 23 is shorter than a predetermined length), the control unit performs image copying to realize double-sided copying instructed by the user. The scanner device 20 starts reading both sides of the document.

  On the other hand, when the tray document sensor 45 detects a document (when the length of the document is equal to or longer than a predetermined length), the control unit reads by the image scanner device 20 even when a reading start instruction is received. It is configured not to start. Even in this case, it is possible to read only one side (the front side of the document), but it may be unwilling for the user to perform single-sided reading even if double-sided scanning is selected. Therefore, the reading of the document itself is stopped. Further, at this time, the control unit may control the display unit of the operation panel 12 so as to display a message indicating that the both sides cannot be read because the document is too long.

  As described above, the image scanner device 20 according to the present embodiment includes the document tray 23, the separation unit 32, the scanner unit 25, the introduction path 80, the reverse path 82, the tray document sensor 45, and the control unit. And. The document tray 23 can set stacked documents. The separation unit 32 separates and conveys the documents stacked on the document tray 23 one by one. The scanner unit 25 reads image information of the original. The introduction path 80 guides the original so that the surface on the front side of the original separated by the separation unit 32 passes the reading position 90 of the scanner unit 25. The reversing path 82 reverses the document and guides it to the reading position 90 of the scanner unit 25 so that the surface on the back side of the document that has been read through the introduction path 80 is read. The document that has passed through the introduction path 80 is guided to the reverse path 82 without being switched back. The tray document sensor 45 can detect that the length of the document set on the document tray 23 is equal to or longer than a predetermined length equal to or shorter than the path length of the turn path. When the tray document sensor 45 detects that the length of the document is equal to or longer than the predetermined length, the control unit prohibits both-side reading of the document.

  Thus, when a document longer than the path length from the reading position 90 to the reading position 90 through the reverse path 82 is set on the document tray 23, the length of the document is equal to or longer than a predetermined length. Can be detected by the tray document sensor 45 to prohibit double-sided reading. Accordingly, since the long original can be prevented from being conveyed again from the reverse path 82 to the reading position 90, it is possible to prevent the reading image from being chipped, show-through, and jammed.

  The image scanner device 20 according to the present embodiment includes an operation panel 12 that can select, for example, one-sided copy mode or two-sided copy mode. When the tray document sensor 45 detects that the length of the document set on the document tray 23 is equal to or longer than the predetermined length before the selection is performed by the operation panel 12, the control unit Selection of the double-sided copy mode by the operation panel 12 is prohibited.

  This prevents the user from selecting the double-sided copy mode when a document longer than a predetermined length is set on the document tray 23. Therefore, since the user can know in advance that there is a document on the document tray that cannot be scanned on both sides, it is possible to prevent the user's useless operation and to start reading the document smoothly.

  In the image scanner device 20 of the present embodiment, for example, a document is set on the document tray 23 after the duplex copy mode is selected by the operation panel 12, and the length of the document is equal to or longer than the predetermined length. When the tray document sensor 45 detects this, the control unit is configured not to start reading the document.

  As a result, even when a document longer than a predetermined length is set on the document tray 23 after the user selects the duplex copy mode, the document is conveyed again from the reverse path 82 to the reading position 90. Can be prevented.

  Although the preferred embodiment of the present invention has been described above, the above configuration can be changed as follows, for example.

  The shape of the path (path) for transporting the document in the ADF and the arrangement of the rollers are not limited to the embodiment, and for example, the second discharge path 84 and the transport roller 38 can be omitted.

  As described in the above embodiment, the predetermined length may be configured to be shorter than the path length of the turn path with a slight margin. When the image scanner device 20 is configured to perform predetermined processing (for example, encoding processing, filtering processing, image data storage processing, etc.) on the read image data every time the image is read, It is preferable to determine the margin in consideration of the processing time of the predetermined processing. This will be described below.

  That is, a certain processing time is required to execute the predetermined process on the image data. In other words, even if the rear end of the front side surface of the document has passed through the reading position 90, it takes some time to complete the predetermined processing on the image data on the front side surface. Therefore, when the length of the document is long, the predetermined processing may not be completed when the document is conveyed through the reverse path 82 and the leading edge of the document reaches the reading position 90 again. However, since the image scanner device 20 according to the present embodiment cannot execute the predetermined process and the image reading at the same time, if the predetermined process for the image data on the front side is not completed, the image on the back side is read. Can not do. As a result, there may be a problem that the leading edge of the image data on the back side is missing. Accordingly, when a document having such a length is set on the document tray 23, it is preferable not to perform duplex reading.

Considering the above points, the length of the document that does not reach the reading position 90 before the predetermined processing on the image data on the front side is completed is set as the predetermined length. The above-described problem can be prevented by the configuration of the invention. In other words, if the margin is set to be equal to or longer than the time required until the predetermined process is completed, the predetermined process for the image data on the front side surface before the leading edge of the document reaches the reading position 90 again. Can be terminated. Specifically, the margin is
Margin ≧ (time taken for the predetermined process to be completed after the trailing edge of the document passes the reading position 90) × (document transport speed)
Thus, whether the length of the document set on the document tray 23 is long enough to start reading the back side after reliably completing the predetermined processing on the image data on the front side. Whether or not (that is, whether or not double-sided reading can be performed) can be determined based on the detection result of the tray document sensor 45. As described above, even when such a margin is provided, the effect of preventing the occurrence of show-through and document jamming can be achieved as in the above-described embodiment.

  However, if the image scanner device 20 is configured so that image reading and the predetermined processing can be executed in parallel, the above margin need not be provided. However, even in this case, it is better to provide a slight margin from the viewpoint of detecting a document having a length that can cause show-through and document jam with a certain margin.

  The image scanner device 20 may include a one-touch button for starting double-sided reading, for example, instead of or in addition to the configuration for selecting whether or not to perform double-sided reading from the menu. In this case, when the tray document sensor detects a document longer than a predetermined length, the operation of the one-touch button can be invalidated by the control unit.

  In addition to the configuration of the above-described embodiment, when it is detected that a long original is additionally set on the original tray 23 during the double-sided reading of the original, the double-sided reading being executed is interrupted. You can also.

  In the above-described embodiment, when a long original is set after selecting double-sided reading, the reading is not performed at all. However, instead of this, it is also possible to have the user select whether to stop reading or to switch to single-sided reading and continue reading.

  The configuration of the above embodiment can be applied not only to a copy facsimile multifunction peripheral but also to, for example, a single image scanner device, a copy machine, and a facsimile device.

1 is a front view of a copy facsimile multifunction peripheral according to an embodiment of the present invention. Front sectional drawing of ADF of this embodiment. FIG. 6 is a front cross-sectional view illustrating a state in which a front side surface of a document guided by an introduction path is read in the case of single-side reading. FIG. 5 is a front cross-sectional view illustrating a state where a document guided to a single-side path is guided to a first discharge path. FIG. 6 is a front cross-sectional view illustrating a state where a document guided to a second discharge path is discharged to a second discharge tray. FIG. 6 is a front cross-sectional view illustrating a state in which a front side surface of a document guided to an introduction path is read in the case of duplex scanning. FIG. 6 is a front cross-sectional view illustrating a state where a reverse side surface of a document guided by a reverse path is read. FIG. 6 is a front cross-sectional view showing a state in a case where it is assumed that a long original is conveyed along a reverse path and both sides are read in the ADF.

Explanation of symbols

10 Copy Facsimile MFP 20 Image Scanner Device (Image Reading Device)
23 Document tray 24 First discharge tray 25 Scanner unit (reading unit)
32 Separating part 45 Tray document sensor 46 Flapper valve 80 Introduction path (introduction path)
82 Reverse path (Reverse path)
90 Reading position

Claims (3)

A document tray on which stacked documents can be set, and
A separation unit that separates and conveys the documents stacked on the document tray one by one;
A reading unit for reading image information of the document;
An introduction path for guiding the original so that a surface on one side of the original separated by the separation section passes through a reading position of the reading section;
A reversing path for reversing the document and guiding it to a reading position of the reading unit so that the other side of the document that has been read on one side through the introduction path is read;
It is possible to detect that the length of the document set in the document tray in the conveyance direction is equal to or longer than a predetermined length less than a path length from the reading position to the reading position through the reversing path. A tray document sensor,
A control unit that prohibits both-side reading of the document when the tray document sensor detects that the length of the document in the conveyance direction is equal to or greater than the predetermined length;
An image reading apparatus comprising: The image reading apparatus according to claim 1,
An operation unit capable of selecting whether to read both sides of the document;
If the tray document sensor detects that the length of the document set on the document tray is not less than the predetermined length before the selection is performed by the operation unit, the control unit An image reading apparatus that prohibits selection by the operation unit to read both sides of the document. The image reading apparatus according to claim 1, wherein
An operation unit capable of selecting whether to read both sides of the document;
The tray document sensor detects that the document is set on the document tray after the operation unit is selected to read both sides of the document and the length of the document in the transport direction is equal to or longer than the predetermined length. In this case, the control unit does not start reading the document.

Images