JP5664951B2 - Automatic document feeder and document reader having the same - Google Patents

Description

  The present invention relates to an automatic document feeder and a document reading device that reads image information while conveying a document by the automatic feeding and conveying device.

  2. Description of the Related Art Conventionally, there has been known an automatic document feeder having a structure in which a branch is provided in a path through which a document is conveyed, and a document passing through the branch location is guided in an appropriate direction by a switching guide disposed at the branch location. . Patent Document 1 discloses an automatic document feeder having a plurality of switching guides.

  The automatic document feeder of Patent Document 1 includes a swing flapper, a follow-up flapper, and an engagement flapper as a switching guide. The follow-up flapper and the engagement flapper are configured to operate according to the operation of the swing flapper. By operating these switching guides, it is possible to switch the path along which the document is conveyed. The automatic document feeder controls the switching guides to operate in accordance with the length of the document in the conveyance direction (document length), and follows an appropriate route according to the document length. The document can be conveyed.

JP 2000-233872 A

  By the way, in the structure provided with a some switching guide like the said patent document 1, in order to avoid the collision of these switching guides, it is necessary to arrange | position each switching guide at an appropriate distance. In particular, in a configuration in which a plurality of switching guides can be individually operated in order to correspond to a plurality of branch points, each switching guide has an operating range that does not include the operating ranges of other switching guides. There was a need to make arrangements. In this case, since the branching portions are separated from each other, the path becomes long and the size of the automatic document feeder increases.

  The present invention has been made in view of the above circumstances, and a main object thereof is to provide a compact configuration in an automatic document feeder provided with a plurality of switching guides.

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 a first aspect of the present invention, an automatic document feeder having the following configuration is provided. That is, the automatic document feeder includes a document transport path, a first switching guide, and a second switching guide. The document transport path is a path for transporting a document, and includes a first branch portion and a second branch portion where the route is branched. The first switching guide can be switched by a first switching driving member so that a path along which the document is conveyed is switched in the first branching section. The second switching guide can be switched by the second switching drive member so that the path where the document is conveyed is switched in the second branching section. The first switching guide and the second switching guide are movable to positions where they overlap each other when viewed in the document width direction. Further, when the first switching guide moves, it is switched whether the document is guided to the second branching section without moving the second switching guide. Further, when the first switching guide guides the document to the second branch portion, the second switching guide moves, and the first switching guide is viewed in the document width direction without moving the first switching guide. When the document is guided along a curved path including a portion where the first switching guide and the second switching guide overlap each other, the conveyance direction and the reverse side of the document are reversed , and the first switching guide and the second switching guide Switching between the state where the document is conveyed between the switching guide and the switching guide.

  Thereby, since the distance between the first switching guide and the second switching guide can be reduced, the size of the automatic document feeder can be reduced. Further, when the first switching guide and the second switching guide are brought close to each other without overlapping, a gap is generated between the first switching guide and the second switching guide, and the document may be caught in this gap. With the above configuration, occurrence of this catch can also be prevented.

  The automatic document feeder preferably has the following configuration. That is, the first switching guide is formed with a first uneven portion including a plurality of grooves and protrusions. The second switching guide is formed with a second concavo-convex portion disposed so as to correspond to the first concavo-convex portion. When the first switching guide and the second switching guide overlap each other, the protrusions of each other enter the groove on the other side.

  Thereby, in the position where a 1st switching guide and a 2nd switching guide mutually overlap, the force which a 1st switching guide and a 2nd switching guide exert with respect to a document can be disperse | distributed to the width direction. Therefore, the original can be appropriately conveyed.

  The automatic document feeder preferably has the following configuration. In other words, the automatic document feeder includes a fixed guide that forms the document conveyance path. The first switching guide can switch between guiding the document to the second branch portion and guiding the document to a path formed by the fixed guide by swinging.

  Thereby, the first branching section is constituted by the fixed guide and the first switching guide, and the path along which the document is conveyed can be switched.

  The automatic document feeder preferably has the following configuration. That is, when viewed in the width direction of the document, the leading end of the first switching guide on the upstream side in the transport direction is in a position overlapping the fixed guide, and the leading end of the first switching guide on the upstream side in the transport direction. The path for guiding the document is different between when the part is in a position where it does not overlap the fixed guide.

  Thereby, since the distance between the first switching guide and the fixed guide can be reduced, the size of the automatic document feeder can be reduced.

  The automatic document feeder preferably has the following configuration. In other words, the automatic document feeder includes a second fixed guide that forms the document conveyance path. When viewed in the width direction of the document, the leading end of the second switching guide on the upstream side in the transport direction is at a position overlapping the second fixed guide, and the leading end of the second switching guide on the upstream side in the transport direction The path for guiding the document is different when the part is at a position where the second fixed guide does not overlap with the second fixed guide.

  As a result, the distance between the second switching guide and the second fixed guide can be reduced, so that the size of the automatic document feeder can be reduced.

The automatic document feeder preferably has the following configuration. That is, the automatic document feeder has a path for guiding the document to the second branch portion when the first switching drive member does not apply force to the first switching guide. When the second switching drive member does not apply force to the second switching guide, a path for discharging the document without inverting it is configured.

That is, when reading a document, it is generally more common to read only one side than to read both sides. In this regard, in the above configuration, the second switching drive member does not need to generate a force when reading and discharging image information on only one side. Therefore, an automatic document feeder excellent in energy saving can be realized.

  According to a second aspect of the present invention, there is provided a document reading apparatus including the automatic document feeder.

  As a result, the size of the apparatus can be reduced, and a document reading apparatus having a configuration that prevents the document from being caught can be realized.

1 is an external perspective view of a multifunction peripheral according to an embodiment of the present invention. FIG. 3 is a front cross-sectional view showing the configuration of the image scanner device. The schematic diagram explaining the introduction path | route and the discharge path for single sides | surfaces. The schematic diagram explaining a 1st inversion path | route. The schematic diagram explaining a 2nd inversion path | route. The schematic diagram explaining the discharge path for both surfaces. The figure which shows the positional relationship of an upper switching guide and a lower switching guide when a 1st inversion path | route is formed. The figure which shows the positional relationship of an upper switching guide and a lower switching guide when a 2nd inversion path | route is formed. The figure which shows the positional relationship of the upper switching guide and the lower switching guide when the single-sided discharge path or the double-sided discharge path is formed. The perspective view which shows the detailed shape of an upper switching guide and a lower switching guide. The front view which shows the structure which drives an upper switching guide and a lower switching guide.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view of a multifunction machine 1 according to an embodiment of the present invention.

  The multifunction device 1 has a copy function and a facsimile function, and an image scanner device (document reading device) 11 that functions as a book scanner and an auto document feed scanner is provided on the upper portion of the multifunction device 1. The multifunction machine 1 also includes an operation panel 12 for instructing the number of copies, a facsimile transmission destination, a document reading, and the like.

  The multifunction device 1 further includes a multifunction device main body 13 including an image forming unit that forms an image on a sheet as a recording medium, and a sheet feeding cassette 14 that sequentially supplies the sheet. The multifunction machine main body 13 includes a transmission / reception unit (not shown) for transmitting image information via a communication line.

  Next, the image scanner device 11 provided in the multifunction machine 1 will be described with reference to FIG. FIG. 2 is a front sectional view showing the configuration of the image scanner device 11. The front view in the present embodiment can also be expressed as a view seen in the width direction of the conveyed document.

  As shown in FIG. 2, the image scanner device 11 includes a document table cover 21, a platen glass 22, and a contact glass 23. The document table cover 21 is provided with an automatic document feeder (auto document feeder, ADF) 24. Further, the image scanner device 11 includes a scanner unit 25 for reading image information of the original 100 below the platen glass 22 and the contact glass 23.

  The scanner unit 25 includes a carriage 110 that can move in the left-right direction inside the document table. In the carriage 110, a light source 111, a plurality of reflecting mirrors 112, a condenser lens 113, and a charge coupled device (CCD) 114 are arranged. The light source 111 irradiates the read original with light, and the reflected light from the read original is reflected by a plurality of reflecting mirrors 112 and then converges through the condenser lens 113 to form an image on the surface of the CCD 114. Then, the CCD 114 converts the incident convergent light into an electrical signal and outputs it.

  Further, as shown in FIG. 2, the ADF 24 provided in the document table cover 21 includes a paper feed tray 52 provided above the document table cover 21 and a paper discharge tray provided below the paper feed tray 52. 53. A document transport path 40 that connects the paper feed tray 52 and the paper discharge tray 53 is formed inside the ADF 24.

  When the user operates the operation panel 12 shown in FIG. 1 to instruct to use the image scanner device 11 as an auto document feed scanner, the original 100 set on the paper feed tray 52 is placed on the original conveyance path 40. It is conveyed one by one along. Then, when the document 100 transported along the document transport path 40 passes through the glass surface (reading position) of the contact glass 23, the image information of the document 100 is read by the scanner unit 25. Thereafter, the document 100 is transported along the document transport path 40 and is discharged to the paper discharge tray 53.

  On the other hand, when the image scanner device 11 is used as a book scanner, the user places a book document to be read on the platen glass 22. Then, the book document is pressed from above by the platen sheet 51 arranged at the lower part of the ADF 24 and fixed so as not to move. In this state, the scanner unit 25 performs reading while moving in the left-right direction, whereby the image information of the book document is read.

  Next, the internal configuration of the ADF 24 will be described in detail. In the following description, when viewed from the front, the side with the paper feed tray 52 may be simply referred to as “right side”, and the opposite side in front view may be simply referred to as “left side”.

  In the ADF 24 according to the present embodiment, the path through which the document 100 is conveyed differs when reading only one side (first surface) of the document 100 and when reading both surfaces (first surface and second surface) of the document 100. It is configured as follows. First, a path for reading only one side of the document 100 and members arranged in the path will be described with reference to FIGS. FIG. 3 is a schematic diagram illustrating the introduction path 41 and the single-side discharge path 43.

  When only one side of the original 100 is read, as shown in FIG. 3, an introduction path 41 for guiding the original 100 to the reading position and a single-sided discharge for guiding the original 100 from the reading position to the paper discharge tray 53. The document 100 is conveyed along the path 43.

  In the introduction path 41, a pickup roller 30, a separation roller 31, a registration roller 32, a triple roller 33, and a conveyance roller 34 are arranged in order from the upstream side. Below, the structure of each part arrange | positioned on the path | route of the introductory path | route 41 is demonstrated from the upstream to the downstream order.

  A pickup roller 30 and a separation roller 31 are disposed in the vicinity of the upstream end of the introduction path 41. The pickup roller 30 is configured to be rotatable around the rotation axis of the separation roller 31. When the ADF 24 is not operating, the pickup roller 30 is held on the upper side in FIG. On the other hand, when the original 100 is fed, the pickup roller 30 rotates downward and comes into contact with the end of the original 100 on the uppermost layer of the originals 100 set on the paper feed tray 52. When the pickup roller 30 rotates in this state, the uppermost document 100 on the paper feed tray 52 is conveyed to the separation roller 31.

  The document 100 sent to the separation roller 31 by the drive of the pickup roller 30 is separated one by one by the rotationally driven separation roller 31 and then conveyed to a registration roller 32 disposed on the downstream side.

  The registration roller 32, together with the opposing roller, temporarily stops and loosens the leading edge of the document 100 being conveyed, and conveys it downstream while removing the slackness after a predetermined time. Thereby, the skew of the document 100 is corrected. The document 100 that has passed the registration roller 32 is conveyed to a triple roller 33 disposed on the downstream side.

  The introduction path 41 from the separation roller 31 to the slightly upstream side of the triple roller 33 is a linear path.

  The triple roller 33 includes a driving roller 331 disposed at the center and driven rollers 332 and 333 disposed vertically so as to sandwich the driving roller 331 therebetween. The document 100 conveyed along the introduction path 41 passes between the driving roller 331 and the driven roller 332 disposed above the driving roller 331 and is conveyed obliquely to the lower left. The document 100 that has passed through the triple roller 33 is conveyed to a conveyance roller 34 disposed on the downstream side. The driven roller 333 disposed below the driving roller 331 has a rotation direction opposite to that of the driven roller 332, and conveys the document 100 passing between the driving roller 331 and the driven roller 333 to the right side. Can do.

  The conveyance roller 34 nips and rotates the original 100 together with the opposite roller, thereby conveying the original 100 to the lower right side (reading position side). Then, when the document 100 passes through the reading position, the image information on the first surface is read by the scanner unit 25. The conveyance roller 34 is configured to be able to switch the rotation direction. By rotating in the reverse direction, the document 100 can be conveyed to the upper left side (the triple roller 33 side).

  The introduction path 41 from the slightly upstream side of the triple roller 33 to the reading position is a path (introduction curve path 411 shown in FIG. 3) that swells to the left side (curves so as to be convex on the left side). .

  Next, the single-sided discharge path 43 will be described. A triple roller 35, a transport roller 36, a common roller 38, and a counter roller 39 are arranged in this order from the upstream side in the single-side discharge path 43. Below, the structure of each part arrange | positioned on the path | route of the single-sided discharge path | route 43 is demonstrated in order of the downstream from an upstream.

  There is a portion that branches vertically on the slightly downstream side of the reading position, and a triple roller 35 is disposed in the vicinity of the branched portion. The triple roller 35 includes a registration roller 351 disposed at the center, and driven rollers 352 and 353 disposed above and below so as to sandwich the registration roller 351 therebetween. The document 100 whose image information has been read by the scanner unit 25 passes between the registration roller 351 and the driven roller 352 disposed above the registration roller 351 and is conveyed obliquely to the upper right. The document 100 that has passed through the triple roller 35 is conveyed to a common roller 38 that is positioned diagonally to the lower right of the conveyance roller 36 by a conveyance roller 36 disposed on the downstream side. The registration roller 351 has the same configuration as that of the registration roller 32. The registration roller 351 is inclined obliquely to the lower left side between the registration roller 351 and the driven roller 353 disposed below the registration roller 351. The line can be corrected.

  The common roller 38 nips and rotates the original 100 together with the opposing roller 39 disposed so as to face the original roller 100, thereby conveying the original 100 to the right side and discharging it to the paper discharge tray 53. As described above, image information on only one side of the original 100 set on the paper feed tray 52 is read. The common roller 38 is configured to be able to switch the rotation direction, and can rotate the document 100 to the left side (reading position side) by rotating in the opposite direction to when the document 100 is discharged.

  Next, a path for reading both sides of the document 100 will be described with reference to FIGS. 2 and 4 to 6. FIG. 4 is a schematic diagram for explaining the first inversion path 45. FIG. 5 is a schematic diagram for explaining the second inversion path 46. FIG. 6 is a schematic diagram for explaining the discharge path 47 for both sides.

  When reading both sides of the original 100, the original set on the paper feed tray 52 is conveyed to the reading position along the introduction path 41, as in the case of reading only one side of the original 100. Then, the image information on the first surface of the document 100 is read by the scanner unit 25. Further, the ADF 24 of the present embodiment is configured to be able to detect the length of the document 100 in the conveyance direction (document length), and operates a route guide or the like (not shown) based on the detected document length. Thus, the path through which the document 100 is conveyed next to the introduction path 41 can be switched.

  First, a path along which the document 100 is conveyed when the document length is short will be described. The document 100 in this case is configured to be conveyed along the first reversing path 45 shown in FIG. 4 after being conveyed along the introduction path 41 to the reading position. The first inversion path 45 includes, in order from the upstream side, a first pre-inversion path 451, a first inversion middle path 452, and a first post-inversion path 453.

  In the first pre-reversal path 451, a triple roller 35 and a transport roller 36 are arranged in order from the upstream side. Similar to the single-side discharge path 43, the document 100 conveyed along the first pre-reversal path 451 passes between the registration roller 351 and the driven roller 352 disposed thereabove and is conveyed diagonally to the upper right. Is done. Then, the document 100 is conveyed rightward by the conveyance roller 36 and conveyed to the first reverse path 452.

  The first inversion middle path 452 guides the document 100 obliquely downward to the right as in the case of the single-side discharge path 43 until halfway. However, after the branch point in the middle, the document 100 is guided so as to be conveyed obliquely downward to the left. This first inversion middle path 452 is a path that swells to the right (curves so as to be convex to the right). By being conveyed along this first reversing path 452, the front and back sides of the document 100 are reversed. That is, after the first surface facing the lower side (scanner unit 25 side) before being transported along the first reversing path 452 is transported along the first reversing path 452, Turn to face. Then, the document 100 conveyed along the first reversing path 452 is conveyed to the first reversing path 453.

  A conveyance roller 37 and a triple roller 35 are arranged in order from the upstream side in the first reverse path 453. The document 100 transported along the first reverse path 453 is transported to the left by the transport roller 37, and after the skew is corrected by the registration roller 351 of the triple roller 35, the document 100 passes through the reading position. In this way, the original 100 when the original length is short is reversed.

  Next, a path for reversing the document 100 when the document length is long will be described. Here, the case where the document length is long means that the document length is equal to the length of the first inversion path 45 or the document length is longer. If the document 100 having a long document length is conveyed along the first reversing path 45, the leading end of the document 100 after reversing the reading position with the trailing edge of the document 100 still remaining at the reading position. Since they are going to pass, the originals 100 overlap and cause a paper jam. Therefore, as shown in FIG. 5, the second inversion path 46 through which the document 100 passes when the document length is long is configured to be longer than the first inversion path 45.

  The second inversion path 46 includes a second pre-inversion path 461, a second inversion middle path 462, and a second post-inversion path 463. The second pre-inversion path 461 extends further to the right than the first pre-inversion path 451. Similar to the first inversion middle path 452, the second inversion middle path 462 has a path swelled to the right side (curved so as to be convex on the right side). The second post-inversion path 463 extends further to the right than the first post-inversion path 453.

The second reverse path 463 passes through the common roller 38 when the document 100 is transported to the left side. However, as described above, the common roller 38 can switch the rotation direction, so that the document 100 is transported to the left side. be able to. Thus, the common roller 38 has a function as a discharge roller and a function as a transport roller. In this way, the document 100 when the document length is long is reversed.

  Then, the original 100 which has been reversed by the first reversing path 45 or the second reversing path 46 and whose image information on the second surface has been read is conveyed to the duplex discharge path 47 shown in FIG.

  The document 100 conveyed along the duplex discharge path 47 passes through the reading position to the left side, and is then conveyed to the upper left side by the conveyance roller 34. Then, the document 100 passes between the driving roller 331 and the driven roller 333 disposed below the driving roller 331 and is conveyed rightward.

  Note that the duplex discharge path 47 from the reading position to the triple roller 33 is a path (a curved discharge path 471 shown in FIG. 6) that bulges to the left (curves so as to be convex on the left). Note that, in the original 100 conveyed along the introduction curved path 411 and the original 100 conveyed along the discharge curved path 471, the conveyance directions of the original 100 are opposite to each other. In this respect, the conveyance roller 34 of the present embodiment can switch the rotation direction, and further, the rotation directions of the driven roller 332 and the driven roller 333 are opposite to each other.

  Then, the document 100 conveyed along the duplex discharge path 47 and passed through the triple roller 33 is conveyed in the right direction, and after passing through the conveyance roller 36, is conveyed obliquely downward to the right. Then, similarly to the original 100 conveyed along the single-sided discharge path 43, it is discharged to the discharge tray 53 by the common roller 38 and the counter roller 39. Note that the double-side discharge path 47 from the branch point slightly downstream of the transport roller 36 to the branch point slightly upstream of the common roller 38 connects the second pre-reverse path 461 and the second post-reverse path 463 ( Connection path 472 shown in FIG. As described above, the image information on both sides of the original 100 set on the paper feed tray 52 is read.

  Next, a member that is arranged in the vicinity of the first reversing path 452 and switches the path for transporting the document 100 will be described with reference to FIGS. FIG. 7 is a diagram illustrating a positional relationship between the upper switching guide 75 and the lower switching guide 76 when the first inversion path 45 is formed. FIG. 8 is a diagram illustrating a positional relationship between the upper switching guide 75 and the lower switching guide 76 when the second reversing path 46 is formed. FIG. 9 is a diagram showing a positional relationship between the upper switching guide 75 and the lower switching guide 76 when the single-side discharge path 43 or the double-side discharge path 47 is formed. FIG. 10 is a perspective view showing the detailed shapes of the upper switching guide 75 and the lower switching guide 76.

  In the vicinity of the first reversing path 452, a fixed guide (first fixed guide) 71, a fixed guide (second fixed guide) 72, a fixed guide 73, and an upper switching guide (first switching guide) 75 , A lower switching guide (second switching guide) 76 is arranged.

  Further, as shown in FIGS. 7 to 9, the upper switching guide 75 has a triangular shape when viewed in the width direction of the document 100. As shown in FIG. 10, the upper switching guide 75 has a configuration in which a plurality of triangular plate materials (triangular plates 751) having a predetermined thickness are stacked in the document width direction. Under the triangular plate 751, an uneven portion (first uneven portion) 754 including a plurality of protrusions and grooves is formed. The upper switching guide 75 is configured to be rotatable about a rotation shaft 752 oriented in the width direction of the document 100 as a rotation center.

  Further, as shown in FIGS. 7 to 9, the lower switching guide 76 is also configured in a triangular shape when viewed in the width direction of the document 100. As shown in FIG. 10, the lower switching guide 76 also has a plurality of triangular plate members (triangular plates 761) having a predetermined thickness arranged in the width direction of the document 100. The downward switching guide 76 is provided with an uneven portion (second uneven portion) 764 composed of a tip portion (projection) of the triangular plate 761 and a portion (groove) where the triangular plate 761 is not formed. I can say. The downward switching guide 76 is configured to be rotatable about a rotation shaft 762 directed in the width direction of the document 100 as a rotation center.

  Then, when the upper switching guide 75 or the lower switching guide 76 rotates, the interval between the protrusions and the grooves is set so that the protrusions of the uneven portion 754 can enter the grooves of the uneven portion 764. . On the other hand, when the upper switching guide 75 or the lower switching guide 76 is rotated, the interval between the protrusions and the grooves is set so that the protrusions of the uneven portion 764 can enter the grooves of the uneven portion 754. . As described above, when the lower portion of the upper switching guide 75 (tip portion on the downstream side in the conveyance direction) and the upper portion of the lower switching guide 76 (tip portion on the upstream side in the conveyance direction) are viewed in the width direction of the document 100, Can be overlapped.

  When the document 100 is guided at the overlapped portion, the document 100 is guided by the plurality of protrusions, so that force is applied evenly (distributed) to the document 100 at a plurality of positions in the width direction. Can do.

  Further, the upper switching guide 75 and the lower switching guide 76 can be rotated independently of each other, and the path along which the document 100 is conveyed can be switched by this rotation. Specifically, by changing the position of the tip of the upper switching guide 75 on the upstream side in the conveyance direction, it is possible to switch between conveying the document 100 obliquely to the lower right or conveying the document 100 to the right. (First branch portion). Further, by changing the position of the leading end portion of the lower switching guide 76 on the upstream side in the conveyance direction, it is possible to switch between conveying the document 100 obliquely to the lower left or conveying the document 100 obliquely to the lower right. (Second branch portion). Hereinafter, the positional relationship of each guide when the first inversion path 45 is formed, when the second inversion path 46 is formed, and when the single-side discharge path 43 or the double-side discharge path 47 is formed. Will be described.

  When the first reversing path 45 is formed, as shown in FIG. 7, a position where the tip of the upper switching guide 75 on the downstream side in the transport direction overlaps the tip of the lower switching guide 76 on the upstream side in the transport direction. It has become a relationship. Further, a lower portion of the fixed guide 71 is formed with a groove (not shown) through which the triangular plate 751 of the upper switching guide 75 can enter. With this configuration, the upstream side of the fixed guide 71 and the upper switching guide 75 in the transport direction. The top end portions of the two are overlapped with each other.

  The document 100 conveyed along the first inversion path 45 formed in this way is first conveyed along the path formed between the upper switching guide 75 and the fixed guide 72. Next, the document 100 is guided by the surface on the side where the first reversing path 45 is formed among the overlapping portions of the upper switching guide 75 and the lower switching guide 76. Thereafter, the document 100 is conveyed toward the reading position along a path formed by the lower switching guide 76 and the fixed guide 73. In this specification, “the document 100 is guided by the surface on the side where the first reversing path 45 is formed among the overlapping portions of the upper switching guide 75 and the lower switching guide 76” is simply described. The document 100 may be referred to as “the document 100 is guided where the upper switching guide 75 and the lower switching guide 76 overlap”.

  When the second reversing path 46 is formed, as shown in FIG. 8, the upper switching guide 75 is located at a position rotated counterclockwise compared to when the first reversing path 45 is formed. Yes. For this reason, the positional relationship is such that the distal end portion of the upper switching guide 75 on the upstream side in the conveyance direction and the fixed guide 71 do not overlap. In addition, when the 2nd inversion path | route 46 is formed, the position of the downward switching guide 76 is arbitrary.

  The document 100 conveyed along the second reversing path 46 formed in this way is conveyed along a linear path formed below the fixed guide 71 and above the upper switching guide 75. The

  When the single-side discharge path 43 or the double-side discharge path 47 is formed, the positional relationship is such that the upper switching guide 75 overlaps the fixed guide 71 as shown in FIG. Specifically, a groove (not shown) is formed on the right side of the fixed guide 72 so that the triangular plate 761 of the lower switching guide 76 can enter. With this configuration, the first inversion path 45 of the fixed guide 72 is formed. The end portion on the side where the folds are formed and the front end portion on the upstream side in the transport direction of the lower switching guide 76 overlap each other.

  The document 100 conveyed along the single-sided discharge path 43 or the double-sided discharge path 47 formed in this way is first along the path formed between the upper switching guide 75 and the fixed guide 72. Be transported. Thereafter, the sheet is conveyed along a path formed above the lower switching guide 76 and reaches the common roller 38.

  Next, a configuration for driving the upper switching guide 75 and the lower switching guide 76 will be described with reference to FIG. FIG. 11 is a front view showing a configuration for driving the upper switching guide 75 and the lower switching guide 76.

A drive mechanism 750 for rotating the upper switching guide 75 includes a solenoid (first switching drive member) 755, a rotation arm 757, and a coil spring 759 as main components.

  The solenoid 755 can be driven so as to retract the movable iron core 756 by passing a current. A rotating arm 757 is attached to the tip of the movable iron core 756 so as to be relatively rotatable. Further, since the rotation arm 757 is configured to be rotatable about the rotation shaft 758, the rotation arm 757 is rotated clockwise when the movable iron core 756 is pulled. Since the rotation arm 757 rotates clockwise, the transmission shaft 753 for transmitting force to the upper switching guide 75 is pulled obliquely to the lower left, and therefore the upper switching guide 75 is moved from the fixed guide 71. It can be turned away.

  The rotating arm 757 has a coil spring 759 attached to the end opposite to the rotating shaft 758. The coil spring 759 biases the rotating arm 757 in the direction indicated by the arrow in FIG. 11 (the direction in which the rotating arm 757 rotates counterclockwise). Therefore, in a state where no current flows through the solenoid 755, the front end portion of the upper switching guide 75 on the upstream side in the transport direction rotates in a direction overlapping the fixed guide 71. Therefore, the upper switching guide 75 can form the first reversing path 45, the single-sided discharge path 43, and the double-sided discharge path 47 without flowing current through the solenoid 755. Therefore, the current flowing through the solenoid 755 can be minimized.

On the other hand, the drive mechanism 760 for rotating the lower switching guide 76 includes a solenoid ( second switching drive member) 765, a rotation arm 767, and a coil spring (elastic member) 769 as main components.

  When a current is passed through the solenoid 765 included in the drive mechanism 760, the movable iron core 766 is drawn toward the solenoid 765, so that the rotating arm 767 rotates clockwise about the rotating shaft 768. By rotating the rotating arm 767 clockwise, the transmission shaft 763 for transmitting force to the lower switching guide 76 can also be rotated clockwise, so that the lower switching guide 76 becomes the upper switching guide 75. It can be rotated in the direction of approach.

  On the other hand, the coil spring 769 biases the rotating arm 767 in the direction shown in FIG. 11 (the direction in which the rotating arm rotates clockwise). Therefore, the lower switching guide 76 rotates in a direction away from the upper switching guide 75 in a state where no current is passed through the solenoid 765. Accordingly, the lower switching guide 76 can form the second reversing path 46, the single-sided discharge path 43, and the double-sided discharge path 47 without flowing current through the solenoid 765. Therefore, the current flowing through the solenoid 765 can be minimized.

  As described above, the ADF 24 according to the present embodiment includes the document conveyance path 40, the upper switching guide 75, and the lower switching guide 76. The document transport path 40 is a path for transporting the document 100, and includes a first branch section and a second branch section where the path is branched. The upper switching guide 75 can switch the path along which the document 100 is conveyed in the first branching section. The lower switching guide 76 can switch the path along which the document 100 is conveyed in the second branching section. The upper switching guide 75 and the lower switching guide 76 are movable to positions where they overlap each other when viewed in the width direction of the document 100. In the second branch portion, when viewed in the width direction of the document 100, the document 100 is guided by the overlapping portion of the upper switching guide 75 and the lower switching guide 76, and the upper switching guide 75 and the lower switching guide 76. The document 100 is guided so that the document 100 is conveyed between the two.

  Thereby, since the distance of the upper switching guide 75 and the lower switching guide 76 can be shortened, the size of the ADF 24 in the height direction can be reduced.

  Further, in the ADF 24 of the present embodiment, the upper switching guide 75 is formed with an uneven portion 754 composed of a plurality of grooves and protrusions. On the other hand, the downward switching guide 76 is provided with an uneven portion 764 disposed so as to correspond to the uneven portion 754. When the upper switching guide 75 and the lower switching guide 76 overlap each other, the projections of each other enter the mating groove.

  As a result, at the position where the upper switching guide 75 and the lower switching guide 76 overlap each other, the force exerted on the document 100 by the upper switching guide 75 and the lower switching guide 76 can be dispersed in the width direction. Therefore, the document 100 can be conveyed appropriately.

  Further, the ADF 24 of the present embodiment includes a fixed guide 71 that forms the document conveyance path 40. The upper switching guide 75 can be rotated to switch between guiding the document 100 to the second branching section or guiding the document 100 to a path formed by the fixed guide 71 and the upper switching guide 75. It is.

  As a result, the fixed guide 71 and the upper switching guide 75 constitute a first branch portion, and the path along which the document 100 is conveyed can be switched.

  Further, in the ADF 24 of the present embodiment, when viewed in the width direction of the document 100, the upstream end portion of the upper switching guide 75 on the upstream side in the conveyance direction overlaps the fixed guide 71 and the fixed guide 71. The route for guiding the document 100 differs depending on the position where it is not.

  Thereby, since the distance of the upper switching guide 75 and the fixed guide 71 can be shortened, the size of the height direction of ADF24 can be made small.

  Further, the ADF 24 of the present embodiment includes a fixed guide 72 that constitutes the document conveyance path 40. When viewed in the width direction of the document 100, the document 100 is guided at a position where the leading end on the upstream side in the conveyance direction of the lower switching guide 76 overlaps with the fixed guide 72 and a position where it does not overlap with the fixed guide 72. The route is different.

  As a result, in addition to the upper switching guide 75, the lower switching guide 76 can be made closer to the fixed guide 72, so that the size of the ADF 24 in the width direction can be reduced.

  Further, the ADF 24 of this embodiment includes a coil spring 769 and a solenoid 765. The coil spring 769 presses the lower switching guide 76 in a direction away from the upper switching guide 75. The solenoid 765 can switch whether or not to apply a force to the lower switching guide 76 in a direction approaching the upper switching guide 75. When the solenoid 765 is not applying force to the lower switching guide 76, the single-sided discharge path 43 is configured.

  As a result, when reading image information on one side of the document 100, it is not necessary to pass a current through the solenoid 765, so that the ADF 24 having excellent energy saving can be realized.

  The preferred embodiment of the present invention has been described above, but the above configuration can be modified as follows, for example.

  In the above embodiment, the coil spring is used as the elastic member. However, if the upper switching guide 75 and the lower switching guide 76 can be biased in a predetermined direction, the elastic member is a member other than the coil spring (for example, a leaf spring, rubber, or the like). Can be used. Further, a member other than the solenoid (for example, a pneumatic cylinder) can be used as the switching drive member.

  A branch point may be provided in the path from the reading position to the conveyance roller 34, and a triple roller may be installed in place of the conveyance roller 34. Thereby, the structure for switching the rotation direction of the conveyance roller 34 can be omitted.

  Instead of the scanner unit 25 of the reduction optical system used in the above embodiment, a configuration using a contact image sensor or the like can be used.

  In the above-described embodiment, the image scanner device 11 is provided as a part of the multifunction device 1. However, instead of this configuration, the image scanner device 11 can be configured as a single image scanner device.

1 MFP 11 Image Scanner Device (Document Reading Device)
24 ADF (Automatic Document Feeder)
40 Document transport path 75 Upper switching guide (first switching guide)
76 Downward switching guide (second switching guide)

Claims (7)

A document transport path, which is a path for transporting a document, and includes a first branch portion and a second branch portion where the path is branched;
A first switching guide capable of switching a path along which the document is conveyed in the first branch portion by being driven by the first switching driving member;
A second switching guide capable of switching a path along which the document is conveyed in the second branch portion by being driven by a second switching drive member;
With
The first switching guide and the second switching guide are movable to positions that overlap each other when viewed in the width direction of the document,
As the first switching guide moves, it is switched whether or not the document is guided to the second branch without moving the second switching guide,
In a state where the first switching guide guides the document to the second branch portion, the second switching guide moves, so that the first switching guide is not moved.
When the document is guided along a curved path including a portion where the first switching guide and the second switching guide overlap when viewed in the width direction of the document, the document conveyance direction and the reverse side are reversed .
A state in which a document is conveyed between the first switching guide and the second switching guide;
Automatic document feeder characterized by switching between the two.
The automatic document feeder according to claim 1,
The first switching guide has a first concavo-convex portion formed of a plurality of grooves and protrusions,
The second switching guide has a second concavo-convex portion disposed so as to correspond to the first concavo-convex portion,
An automatic document feeder, wherein when the first switching guide and the second switching guide overlap each other, the projections of each other enter the groove on the other side. The automatic document feeder according to claim 1 or 2,
A fixed guide that forms the document transport path;
The first switching guide is swingable to switch between guiding the document to the second branching section and guiding the document to a path formed by the fixed guide. Document feeder. The automatic document feeder according to claim 3,
When viewed in the width direction of the document, the leading end portion on the upstream side in the transport direction of the first switching guide is at a position overlapping the fixed guide, and the leading end portion on the upstream side in the transport direction of the first switching guide is The automatic document feeder is characterized in that a route for guiding a document is different between when the fixed guide and the fixed guide are not overlapped with each other. The automatic document feeder according to claim 3 or 4,
A second fixed guide that forms the document transport path;
When viewed in the width direction of the document, the leading end of the second switching guide on the upstream side in the transport direction is at a position overlapping the second fixed guide, and the leading end of the second switching guide on the upstream side in the transport direction The automatic document feeder is characterized in that the path for guiding the document is different when the section is at a position where the second fixed guide does not overlap with the second fixed guide. An automatic document feeder according to any one of claims 1 to 5,
When the first switching drive member does not apply force to the first switching guide, a path for guiding the document to the second branch portion is configured,
An automatic document feeder comprising a path for discharging the document without reversing when the second switching drive member does not apply force to the second switching guide.
  A document reading apparatus comprising the automatic document feeder according to any one of claims 1 to 6.

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