JP2010269934A - Image reading device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a construction excellent in energy saving and quietness in an image reading device capable of reading both sides of a document. <P>SOLUTION: An image scanner device 20 includes a plurality of feed rollers for delivering the document along a document delivery passage, and these feed rollers are driven by a first motor 201. Clutches 58 and 66 can switch between transmission and interruption of the power of the first motor 201 transmitted by a transmission gear group 71, with respect to these feed rollers. In single side reading mode, a controller included in the image scanner device 20 transmits the power generated by the first motor 201 to the feed roller dedicated to single side reading among the plurality of feed rollers, and controls the clutches 58 and 66 not to transmit the power to the roller dedicated to double side reading. In double side reading mode, the controller transmits the power generated by the first motor 201 to the roller dedicated to double side reading, and controls the clutches 58 and 66 not to transmit the power to the roller dedicated to single side reading. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image reading apparatus capable of reading both sides of a document.

  In an image reading apparatus such as an image scanner apparatus equipped with an automatic document feeder (ADF), various configurations have been proposed in order to automatically read images on both sides of a document. For example, a configuration in which a document reading unit is provided for each of the front side and the back side and both sides are read in one pass, a configuration having a so-called switchback function for reversing the document transport direction, and the like are known.

  In addition to the above, there is known an image reading apparatus configured to read both the front side surface and the back side surface of a document with a single reading unit by providing a path for inverting the document. Patent Document 1 and Patent Document 2 disclose this type of image reading apparatus.

  Patent Document 1 discloses an image reading apparatus configured as follows. That is, the image reading apparatus includes a sheet conveyance path having an introduction path, a reverse path, and a discharge path. The introduction path guides the document from one end to the reading position. The reversing path is formed in an annular shape that reverses the front and back of the document discharged from the other end of the reading position and guides it from the other end to the reading position again. The discharge path discharges the document discharged from the one end portion of the reading position to the discharge portion. The automatic document feeder is provided in the sheet conveyance path, and drives a plurality of document feeding rotators rotating in one direction in which a sheet document is fed, and the document feeding rotator. Driving means rotating in one direction.

  Patent Document 2 discloses an image reading apparatus configured as follows. That is, the image reading apparatus includes a tray on which documents are stacked and a feeding unit that feeds the documents one by one from the tray. The double-sided document feeder also feeds the first surface of the fed document to the scanning surface, and after scanning, reverses the front and back surfaces of the document and feeds the second surface of the document to the scanning surface. A conveying means for discharging after scanning is provided. The conveying means includes a first conveying means for feeding the first surface of the fed document to the scanning surface, and the front and back surfaces of the document after scanning the first surface without reversing the conveying state of the document. Reversing means for reversing the front and back surfaces. Further, the conveying means shares a part of the first conveying means in order to send the second surface of the document whose front and back surfaces are reversed without reversing the conveying state by the reversing means to the scanning surface. And a second conveying means for feeding in the direction opposite to the feeding direction of the first surface through the conveying unit. The conveying means includes a branching means for selectively branching the direction of feeding to the scanning surface from the position of the conveying unit sharing the part through the first or second conveying means, and a second surface Discharging means for discharging the document after scanning.

JP-A-6-247642 JP 10-69129 A

  Since the image reading apparatuses of Patent Documents 1 and 2 need to have a reversing path, it is difficult to configure the conveyance path to be shorter than the one-pass method or the switchback method described above. In addition, since it is necessary to arrange a large number of conveying rollers (original feed rotating bodies), a motor having a relatively large size or a plurality of motors are often required to drive these conveying rollers. As a result, power consumption increases and noise during document conveyance also increases.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image reading apparatus that has a reversing path and has means for reading images on both sides of a document, and is excellent in energy saving and quietness. Is to provide.

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, a document conveyance path, a feed roller, a drive source, a power transmission unit, a clutch, and a control unit. A document can be set on the document tray. 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 document transport path guides the document so that only one side of the document is read by the reading unit when reading only one side of the document, and both sides of the document are read when reading both sides of the document. The document is guided to be read by the reading unit. The feed roller conveys the document along the document conveyance path. The drive source generates power for rotating the feed roller. The power transmission unit transmits power generated by the drive source. The clutch can be switched between transmitting or interrupting the power of the power transmission unit to the feed roller. When the controller reads only one side of the document, it transmits the power generated by the drive source to the feed roller used to read only one side of the feed rollers and reads both sides. The clutch is controlled so that it is not transmitted to at least a part of the feed roller used only for. In addition, when reading both sides of the document, the control unit transmits the power generated by the drive source to a feed roller used only when reading both sides of the feed roller, and only one side is read. The clutch is controlled so that it is not transmitted to at least some of the feed rollers used only for reading.

  Thereby, an ADF type image reading apparatus capable of switching between single-sided reading and double-sided reading can be provided. Further, since power can be prevented from being transmitted to the feed roller on the path where the document is not conveyed, the load on the drive source can be reduced, and an energy-saving and low-noise image reading apparatus can be realized.

  In the image reading apparatus, the clutch is preferably an electromagnetic clutch.

  Thereby, the image reading apparatus can be reduced in size and weight. Further, since the electromagnetic clutch can be controlled by an electric signal, it can be controlled with a simple configuration.

  The image reading apparatus preferably has the following configuration. That is, the document transport path includes a single-side dedicated path and a double-side dedicated path. The single-side dedicated path conveys the original only when reading only one side of the original. The double-side dedicated path transports the original only when reading both sides of the original. The feed roller includes a single-side feed roller and a double-side feed roller. The single-side dedicated feed roller is installed in the single-side dedicated path. The duplex duplex feed roller is installed in the duplex duplex path. When reading only one side of the document, the control unit transmits the power of the drive source to the single-side dedicated feed roller and shuts off the power of the drive source to the double-side dedicated feed roller. The clutch is controlled as follows. On the other hand, when reading both sides of the original, the control unit transmits the power of the drive source to the dedicated duplex feed roller and shuts off the power of the drive source to the dedicated duplex feed roller. The clutch is controlled to do so.

  As a result, the feed roller that is not necessary for conveying the document can be stopped only by controlling the clutch. Therefore, further energy saving can be realized.

  In the image reading apparatus, the duplex dedicated path includes a first duplex dedicated path and a second duplex dedicated path. The first double-side dedicated path guides the original so that one side of the original separated by the separation unit is read by the reading unit. The second double-side exclusive path guides the original so that the other side of the original read on one side through the first double-side exclusive path is read by the reading unit.

  Thus, by providing the first duplex dedicated path and the second duplex dedicated path, it is possible to flexibly set the path through which the document is conveyed during duplex scanning.

  In the image reading apparatus, it is preferable that the clutch is installed in the vicinity of a junction where the single-side dedicated path and the double-side dedicated path merge.

  Thereby, the structure of the power transmission path including the power transmission unit and the clutch can be simplified.

  In the image reading apparatus, the power generated by the drive source includes the power transmission unit, and a power transmission unit that transmits power to a feed roller disposed in the vicinity of a document reading position by the reading unit, It is preferable to be divided and transmitted.

  As a result, the feed roller in the vicinity of the reading position is directly driven without passing through the clutch, so that it is possible to avoid the backlash of the clutch from adversely affecting the rotation of the feed roller in the vicinity of the reading position. As a result, blurring at the time of reading the document can be suppressed, and distortion of the read image can be prevented.

  In the image reading apparatus, it is preferable that a current flowing through the driving source when reading only one side is smaller than a current flowing through the driving source when reading both sides.

  As a result, when only one side of the original is read, power consumption during conveyance of the original can be saved. On the other hand, when both sides of a document are read, a large amount of power is generally required as compared to when only one side is read, but a sufficient current can be supplied to generate the power.

1 is a front view of a multifunction machine according to an embodiment of the present invention. FIG. 3 is a front cross-sectional view of an ADF in an image scanner device provided in the multifunction peripheral. The front view which shows the power transmission path | route for transmitting motive power to each roller of ADF. The block diagram which shows the electric constitution of ADF.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a multifunction machine 10 according to an embodiment of the present invention.

  A multifunction device 10 shown in FIG. 1 includes an image scanner device (image reading device) 20 that functions as a book scanner and an auto document feed scanner at the top of the multifunction device 10. The multifunction machine 10 further includes an operation panel 12 for instructing the number of copies, a document reading mode (single-sided reading mode, double-sided reading mode, etc.) and the like.

  Further, the multifunction machine 10 includes a main body 11 having an image forming unit that forms an image on a sheet as a recording medium, and a sheet feeding cassette 79 that sequentially supplies the sheet. The main body 11 includes a transmission / reception unit (not shown) for transmitting image data via a communication line.

  The image scanner device 20 includes a platen glass (not shown) and a document table cover 13. The document table cover 13 is provided with an automatic document feeder (auto document feeder, ADF) 21. The image scanner device 20 includes a scanner unit 25 for reading an image of a document.

  The scanner unit 25 is configured as a scanner unit of a reduction optical system including a light source, a reflection mirror, a condenser lens, a CCD, and the like, and can read a document conveyed in the ADF 21 at a predetermined reading position 90. 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.

  With the above configuration, when the image scanner device 20 is used as an auto document feed scanner, the ADF 21 transports documents one by one. Then, only one side or both sides of the original are read by the scanner unit 25.

  On the other hand, when the image scanner device 20 is used as a book scanner, a user places a book document to be read on the platen glass and presses it from above with a document table cover 13 to fix the book document so that it does not move. To do. In this state, the scanner unit 25 can read the original image.

  Image data read by any of the methods described above is input to the image forming apparatus or the like. The data is printed on the paper supplied from the paper feed cassette 79, so that the copy function of the multifunction machine 10 can be realized. Alternatively, the facsimile transmission function of the multifunction machine 10 can be realized by transmitting image data to the facsimile machine of the other party.

  Next, a detailed configuration of an ADF (automatic document feeder, auto document feeder) 21 included in the image scanner device 20 will be described with reference to FIG. FIG. 2 is a front sectional view of the ADF 21.

  The image scanner device 20 includes a scanner unit 25 for reading a document 99 and an ADF 21 for conveying the document 99. A contact glass 45 for reading the document 99 is disposed at the bottom of the ADF 21. Has been. The contact glass 45 is disposed so as to correspond to the reading position 90 of the scanner unit 25. The contact glass 45 is disposed so as to face the lower surface of the document 99 that passes through the reading position 90.

  Inside the ADF 21, a curved document transport path 70 that connects the document tray 23 and the discharge tray 24 so as to pass the reading position 90 is configured. The document conveyance path 70 includes an introduction path 80, a single-side exclusive path (single-side exclusive path) 81, a first double-side exclusive path (first double-side exclusive path) 83, and a second double-side exclusive path (second double-side exclusive path). 84, a common guide path 85, and a discharge path 82. Hereinafter, these paths constituting the document conveyance path 70 will be described.

  The introduction path 80 is for introducing the document 99 on the document tray 23 into the ADF 21. As shown in FIG. 2, the introduction path 80 is configured to extend substantially horizontally from the position where the document 99 on the document tray 23 is supplied into the ADF 21 in a direction away from the document tray 23. A pickup roller 31 is disposed on the introduction path 80. Further, on the downstream side of the pickup roller 31 and on the path of the introduction path 80, a separation unit 32 including a separation roller and a counter roller disposed to face the separation roller is disposed.

  The pickup roller 31 is configured to be rotatable around 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 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 to the registration roller 33 on the downstream side. The registration roller 33 is composed of a pair of rollers arranged on the downstream side of the separation unit 32 and on the path of the introduction path 80. The registration roller 33 temporarily stops and loosens the leading side of the document conveyed by the separating unit 32, and conveys the document to the downstream side while removing the slack after a predetermined time. Thereby, the skew of the original is corrected.

  On the downstream side of the registration roller 33, a three-way branch is connected to the downstream end of the introduction path 80, the upstream end of the single-side dedicated path 81, and the upstream end of the first double-sided dedicated path 83. A portion 91 is formed. A switching device 95 is disposed in the branch portion 91, and the switching device 95 includes a rotating member formed in a claw shape and a solenoid (not shown). The switching device 95 can distribute the document 99 conveyed from the introduction path 80 by driving the registration roller 33 to the single-side exclusive path 81 or the first double-side exclusive path 83 by rotating the rotating member by the solenoid. It is configured.

  The path switching between the single-side dedicated path 81 and the first double-side dedicated path 83 is performed by the control unit 110 (see FIG. 4) provided in the main body 11 based on the specification of the document reading mode on the operation panel 12. ). The control unit 110 is a microcomputer, and includes a CPU as a calculation unit and ROM and RAM as storage units.

  The single-side dedicated path 81 is a path used only when reading one side of the document 99. As shown in FIG. 2, the single-side dedicated path 81 extends substantially horizontally from the branching portion 91 in a direction away from the document tray 23 and passes above the contact glass 45 (reading position 90), and then its direction is lowered. It is comprised so that it may curve so that it may face. The single-side dedicated path 81 is configured to connect to the upstream end of the common guide path 85 while joining the second double-side dedicated path 84 at the junction 92. Conveying rollers (single-side dedicated feed rollers) 34 and 35 are arranged on the path of the single-side dedicated path 81. By driving these rollers, the document 99 guided to the single-side exclusive path 81 can be conveyed to the junction 92.

  The common guide path 85 is a path that is commonly used in both cases of single-sided reading and double-sided reading. The common guide path 85 has a shape that extends downward from the junction 92 and is bent obliquely toward the reading position 90 (to the discharge tray 24 side). On the common guide path 85, a conveying roller (feed roller) 36 and a triple roller (feed roller) 37 are arranged. By driving the transport roller 36 and the triple roller 37, the document 99 sent to the junction 92 can be transported to the reading position 90 at the bottom of the ADF 21. The configuration of the triple roller 37 will be described later.

  In the present embodiment, the reading position 90 by the scanner unit 25 is configured to be located on the downstream side of the laterally U-shaped folded portion 93 including the single-side dedicated path 81 and the common guide path 85. Accordingly, the original 99 is guided to the reading position 90 in an inverted state by a route constituted by the single-side exclusive path 81 and the common guide path 85. Here, the document 99 is set on the document tray 23 so that the surface on the front side faces upward. Accordingly, the document 99 passes through the turn-back portion 93 so that the front side surface thereof is directed downward, and is conveyed so as to face the reading surface (contact glass 45) of the scanner unit 25 at the reading position 90. Become. The transport direction of the document 99 when it is transported through the single-side exclusive path 81 and passes the reading position 90 is opposite to the direction in which the document 99 is fed into the introduction path 80 by the pickup roller 31.

  The document 99 whose image has been read at the reading position 90 of the scanner unit 25 is guided to the discharge path 82. The discharge path 82 is disposed below the first double-sided dedicated path 83, and is configured to extend slightly obliquely upward from the reading position 90 and then extend substantially horizontally to connect to the discharge tray 24. . A triple roller (feed roller) 40 and a discharge roller 39 are arranged on the path of the discharge path 82, and the document 99 is discharged to the discharge tray 24 by driving these rollers. . The configuration of the triple roller 40 will be described later.

  The first duplex dedicated path 83 is a path that is used only when both sides of the document 99 are read. The first double-sided path 83 is positioned below the single-sided dedicated path 81 and is configured to be substantially straight toward the reading position 90. The guide roller 38 and the triple roller 40 are disposed on the path of the first double-side exclusive path 83, and the document 99 is conveyed to the reading position 90 by driving these rollers. The transport direction when the document 99 that has passed through the first duplex dedicated path 83 passes through the reading position 90 is opposite to the transport direction when the document 99 that has passed through the single-side dedicated path 81 passes through the read position 90. It has become.

  The first double-sided pass 83 is configured to convey the original 99 to the reading position 90 without being reversed, unlike the single-sided dedicated pass 81. Accordingly, when the document 99 set on the document tray 23 with the front side facing upward is conveyed to the reading position 90 via the first duplex duplex path 83, the back side is read. The first double-side dedicated path 83 is connected to the upstream end portion of the second double-side dedicated path 84 on the downstream side of the reading position 90 and in the vicinity of the bottom of the ADF 21.

  Similarly to the first double-sided path 83, the second double-sided dedicated path 84 is used only when both sides of the document 99 are read. As shown in FIG. 2, the second double-side dedicated path 84 is configured in a substantially U-turn shape so that the document 99 can be reversed by the folding portion 94. Specifically, the second dedicated duplex path 84 extends substantially horizontally (in a direction away from the discharge tray 24) from the reading position 90 at the bottom of the ADF 21, and then curves so that the direction is directed upward. Thereafter, the second double-side exclusive path 84 is bent downward so as to approach the document tray 23, is bent downward, and merges with the single-side exclusive path 81 at the merging section 92. It is comprised so that it may connect with an upstream edge part.

  On the path of the second double-side exclusive path 84, the triple roller 37 and the transport rollers (double-side exclusive feed rollers) 41, 42, 43 are arranged. With this configuration, the back surface of the document 99 is read at the reading position 90 after passing through the first duplex duplex path 83, and the document 99 guided to the second duplex dedicated path 84 is reversed by the folding unit 94 and then the document. In the state where the up and down directions are reversed, the sheet is conveyed to the merging portion 92 and thereafter is guided again to the reading position 90 by the common guide path 85 (conveying roller 36 and triple roller 37). Therefore, when the original 99 passes the reading position 90 for the second time, the front side surface of the original 99 is read. The direction in which the document 99 that has passed through the second duplex dedicated path 84 passes through the reading position 90 is opposite to the direction in which the document 99 that has passed through the first duplex dedicated path 83 passes through the reading position 90. .

  Further, in the present embodiment, the second double-side dedicated path 84 is configured so that the path is a relatively long distance. This is to enable reading of a long document. In other words, if the distance between the second double-side dedicated path 84 and the common guide path 85 is short, the original that has passed through the reading position and turned back by the second double-side exclusive path is read again at the reading position. A part (the end side) of the image has not yet passed through the reading position, causing interference and reading cannot be performed normally.

  In this regard, in the configuration of the present embodiment, the length of the second double-side dedicated path 84 is sufficiently secured so that a document having a certain length can be read appropriately. Further, the length of the document 99 passing through the second duplex dedicated path 84 varies, and even a short-length document can be appropriately conveyed along the second duplex dedicated path 84 along the path. It is necessary to shorten the interval between the arranged conveying rollers to some extent. Accordingly, in the present embodiment, a relatively large number (specifically, three) of the transport rollers 41, 42, 43 are provided in the second double-side dedicated path 84 corresponding to the long path. They are arranged in the double-side exclusive path 84.

  Further, in the present embodiment, the downstream end portion (merging portion 92) of the single-side dedicated path 81 and the second double-side dedicated path 84 and the reading position 90 are connected by a common route (common guide path 85). It is configured as follows. In other words, the single-side exclusive path 81 and the second double-side exclusive path 84 merge at the junction 92, and the common guide path 85 from the junction 92 to the reading position 90 is common for single-side reading and double-side reading. To be used. As a result, the members (conveying roller 36, triple roller 37, etc.) for conveying the document 99 can be shared, and the number of parts can be reduced. In addition, the document conveyance path 70 can be compactly integrated, and the space in the ADF 21 can be efficiently used.

  The triple roller 40 will be described. The triple roller 40 is composed of a driving roller disposed on the center side and two driven rollers disposed so as to sandwich the driving roller. The triple roller 40 is disposed in the vicinity of the reading position 90 so that the driving roller is sandwiched between the first duplex dedicated path 83 and the discharge path 82. One of the two driven rollers is disposed to face the driving roller with the first double-sided dedicated path 83 interposed therebetween, and the other driven roller is disposed to face the driving roller with the discharge path 82 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.

  The triple roller 37 has the same configuration as the triple roller 40, and its drive roller is sandwiched between the second double-side dedicated path 84 and the common guide path 85 so that the vicinity of the reading position 90 Is arranged. One of the two driven rollers is disposed at the bottom of the ADF 21 in the vicinity of the reading position 90 so as to face the driving roller with the second dedicated duplex path 84 interposed therebetween. The other driven roller is disposed obliquely above the drive roller so as to face the drive roller across the common guide path 85.

  Further, rollers other than the triple roller (separation roller of separation unit 32, registration roller 33, conveyance rollers 34 to 36, guide roller 38, discharge roller 39, conveyance rollers 41 to 43) are also driven rollers and driven rollers facing each other. It consists of and. That is, in FIG. 2, among the rollers arranged in pairs with the document path interposed therebetween, the driving roller is depicted slightly larger, and the other roller is the driven roller. Further, in the separation unit 32, a driving roller is depicted on the upper side in FIG.

  Each of the driving rollers is driven by transmitting a driving force of a motor described later. On the other hand, the driven roller is pressed against the driving roller by an elastic member (not shown) so that the document 99 can be nipped with the driving roller.

  Next, a configuration for driving the above-described rollers disposed in the document conveyance path 70 will be described with reference to FIG. FIG. 3 is a front view showing a drive transmission path for transmitting power to each roller of the ADF 21.

  The power of each roller (drive roller) described with reference to FIG. 2 is supplied by a first motor (drive source) 201 and a second motor 202 shown in FIG. Specifically, the transport rollers 34 to 36 and 41 to 43 and the triple rollers 37 and 40 are driven by the first motor 201. Further, the separation roller, the registration roller 33, the guide roller 38, and the discharge roller 39 of the separation unit 32 are driven by the second motor 202.

  A first motor gear 50 and a second motor gear 59 are fixed to the output shafts of the first motor 201 and the second motor 202, respectively. The ADF 21 also includes a transmission member group for transmitting the power generated by the first motor 201 and the second motor 202 to each roller. This transmission member group is roughly divided into a transmission gear group (power transmission unit) 71, a single-side dedicated pulley group 72, a double-side dedicated gear group 73, a reading gear group (power transmission unit) 74, and a second gear. And a group 75.

  The first motor 201 and the second motor 202 are configured as electric motors. As shown in FIG. 4, these motors 201 and 202 are electrically connected to the control unit 110, and the control unit 110 can appropriately control the rotation and stop of the respective motors 201 and 202. In addition, the ADF 21 includes a current control unit 111, and the current control unit 111 is configured to change the current flowing through the first motor 201 in accordance with a signal from the control unit 110.

  As shown in FIG. 3, the first motor gear 50 driven by the first motor 201 meshes with the transmission gear 55 of the transmission gear group 71 and also meshes with the transmission gear 51 of the reading gear group 74.

  The transmission gear group 71 includes a roller gear 56 and a transmission gear 57 in addition to the transmission gear 55. The transmission gear 55 meshes with both the roller gear 56 and the transmission gear 57. The roller gear 56 is connected to the transport roller 36 shown in FIG. 2 by a shaft. As shown in FIG. 3, the transmission gear 57 meshes with the input gear of the first clutch 58 and also meshes with the input gear of the second clutch 66.

  The reading gear group 74 includes a roller gear 53, a transmission gear 52 and a roller gear 54 in addition to the transmission gear 51. The transmission gear 51 meshes with both the roller gear 53 and the transmission gear 52. Further, the roller gear 54 meshes with the transmission gear 52. The roller gear 53 is connected to the triple roller 37 shown in FIG. 2 by a shaft. The roller gear 54 shown in FIG. 2 is connected to the triple roller 40 shown in FIG. 3 by a shaft.

  The first clutch 58 includes an input gear and an output gear arranged coaxially. Further, the first clutch 58 is disposed in the vicinity of the junction 92 (FIG. 2) where the single-side dedicated path 81 and the second double-side dedicated path 84 merge. The input gear meshes with the transmission gear 57 of the transmission gear group 71, and the output gear meshes with the transmission gear 68 of the one-side dedicated pulley group 72. The first clutch 58 is configured as a known electromagnetic clutch, and is between a contact state (power transmission state) in which the input gear and the output gear are integrally connected and a disconnection state (disconnection state) in which the connection is released. Can be switched. As shown in FIG. 4, the first clutch 58 is electrically connected to the control unit 110. The controller 110 can switch the state of the first clutch 58 by outputting a control signal to the first clutch 58.

  Similar to the first clutch 58, the second clutch 66 also includes an input gear and an output gear arranged coaxially. Further, the second clutch 66 is disposed in the vicinity of the joining portion 92 (FIG. 2) where the single-side dedicated path 81 and the second double-side dedicated path 84 merge. The input gear meshes with the transmission gear 57 of the transmission gear group 71, and the output gear meshes with the two roller gears 62, 63 of the double-side dedicated gear group 73. The second clutch 66 is also configured as an electromagnetic clutch, and is switched between a contact state (power transmission state) in which the input gear and the output gear are integrally connected and a disconnection state (disconnection state) in which the connection is released. be able to. As shown in FIG. 4, the second clutch 66 is electrically connected to the control unit 110. The controller 110 can switch the state of the second clutch 66 by outputting a control signal to the second clutch 66.

  The single-side dedicated pulley group 72 includes two pulleys 64 and 65 in addition to the transmission gear 68. A pulley is fixed to the transmission gear 68, and a timing belt 60 is wound around the pulley and the two pulleys 64 and 65. A belt roller 69 is installed so as to be in contact with the outer periphery of the timing belt 60. The belt roller 69 ensures the winding angle of the timing belt 60 with respect to the pulley 65 by bending the track of the timing belt 60. The pulley 64 is connected to the transport roller 34 shown in FIG. 2 by a shaft. Further, the pulley 65 shown in FIG. 3 is connected to the conveying roller 35 shown in FIG. 2 by a shaft.

  The double-side dedicated gear group 73 includes a transmission gear 67 and a roller gear 61 in addition to the roller gears 62 and 63. The transmission gear 67 meshes with the roller gear 62, and the roller gear 61 meshes with the transmission gear 67. The roller gear 63 is connected to the transport roller 43 shown in FIG. 2 by a shaft. Further, the roller gear 62 shown in FIG. 3 is connected to the conveying roller 42 shown in FIG. 2 by a shaft. Further, the roller gear 61 shown in FIG. 3 is connected to the conveying roller 41 shown in FIG. 2 by a shaft.

  As shown in FIG. 3, the second motor gear 59 driven by the second motor 202 meshes with the transmission gear 101 of the second gear group 75.

  In addition to the transmission gear 101, the second gear group 75 includes a roller gear 109, a transmission gear 104, a roller gear 108, a transmission gear 105, a transmission gear 106, a roller gear 103, a transmission gear 107, and a roller gear 102. The transmission gear 104 meshes with the transmission gear 104 at the same time as meshing with the roller gear 109. The transmission gear 104 meshes with the transmission gear 105 at the same time as meshing with the roller gear 108. The transmission gear 105 meshes with the transmission gear 106, and the transmission gear 106 meshes with the roller gear 103. The roller gear 103 meshes with the transmission gear 107, and the transmission gear 107 meshes with the roller gear 102.

  The roller gear 109 is connected to the discharge roller 39 of FIG. 2 by a shaft. The roller gear 108 shown in FIG. 3 is connected to the guide roller 38 shown in FIG. 2 by a shaft. The roller gear 103 shown in FIG. 3 is connected to the registration roller 33 shown in FIG. 2 via a clutch (not shown). The roller gear 102 shown in FIG. 3 is connected to the drive roller of the separation unit 32 shown in FIG. 2 via a clutch (not shown).

  Next, a case where the original 99 is conveyed by the ADF 21 having the above configuration and only one side (front side) is read will be described.

  Assume that the user designates the single-sided reading mode by operating the operation panel 12 of FIG. 1 or the like, sets the document 99 on the document tray 23, and instructs the multifunction device 10 to start copying. Then, under the control of the control unit 110 shown in FIG. 4, the switching device 95 switches the path of the document 99 to the single-side dedicated path 81 side. The control unit starts driving the first motor 201 and the second motor 202, and controls the first clutch 58 to be in the engaged state and the second clutch 66 to be in the disengaged state. As a result, the driving forces of the motors 201 and 202 are transmitted to the transmission gear group 71, the single-side dedicated pulley group 72, the reading gear group 74, and the second gear group 75.

  By driving the second gear group 75, the pickup roller 31 and the separation unit 32 of the ADF 21 are driven. Accordingly, the document 99 is separated one by one by the separation unit 32, passes through the introduction path 80, and is guided to the single-side dedicated path 81 (by the switching device 95). Further, the conveying rollers 34 and 35 are driven via the single-side exclusive pulley group 72, the conveying roller 36 is driven via the transmission gear group 71, and the triple roller 37 is driven via the reading gear group 74. . Accordingly, the document 99 is conveyed along the single-sided dedicated path 81 and the common guide path 85 by the rotation of the roller, and is sent to the reading position 90 while making a U-turn at the folding unit 93. The contents of the document 99 are read by the reading surface (contact glass 45) of the scanner unit 25 located below the reading position 90.

  Further, the triple roller 40 is driven via the reading gear group 74, and the discharge roller 39 is driven via the second gear group 75. Accordingly, the document 99 that has passed through the reading position 90 is conveyed along the discharge path 82 by the rotation of the roller and is discharged to the discharge tray 24.

  In this single-sided reading mode, since the second clutch 66 is in a disconnected state, power transmission to the double-sided dedicated gear group 73 is cut off, and the transport rollers 41, 42, and 43 of the second double-sided dedicated path 84 are driven. Not. Accordingly, the driving of the portion of the second double-side exclusive path 84 through which the document 99 does not pass can be stopped, so that power consumption of the first motor 201 can be saved and noise can be reduced. In the present embodiment, the control unit 110 controls the current flowing through the first motor 201 in the single-sided reading mode through the current control unit 111 (FIG. 4) so that the current flowing in the first motor 201 is slightly smaller than that in the double-sided reading mode. Electric power is realized. In particular, in the present embodiment, as described above, since the number of transport rollers 41, 42, 43 in the second double-side dedicated path 84 is relatively large, the effects of power saving and noise reduction are remarkable.

  Next, a case where both sides of a document are read will be described.

  Assume that the user operates the operation panel 12 shown in FIG. 1 to designate the double-sided reading mode, sets the document 99 on the document tray 23, and instructs the MFP 10 to start copying. Then, under the control of the control unit 110 in FIG. 4, the switching device 95 switches the path of the document 99 to the first duplex dedicated path 83 side. Then, the control unit 110 starts driving the first motor 201 and the second motor 202 in the same manner as in the single-sided reading mode, makes the first clutch 58 disengaged, and makes the second clutch 66 engaged. Control. As a result, the driving forces of the motors 201 and 202 are transmitted to the transmission gear group 71, the double-sided dedicated gear group 73, the reading gear group 74, and the second gear group 75.

  Accordingly, the pickup roller 31 and the separation unit 32 are driven as in the above-described single-sided reading mode. Further, the guide roller 38 and the triple roller 40 are driven in the same manner. Accordingly, the document 99 that has been separated by the separation unit 32 and passed through the introduction path 80 is guided (by the switching device 95) to the first double-sided path 83 side, and is conveyed obliquely in a substantially straight line to the reading position 90.

  Since the original 99 is transported without being reversed in the first double-sided pass 83, the lower surface (rear surface) of the original 99 is read first at the reading position 90. The document 99 that has passed the reading position 90 is conveyed to the second duplex exclusive path 84.

  Further, the triple roller 37 and the transport roller 36 are driven through the reading gear group 74, and the transport rollers 41 to 43 are driven by the double-side dedicated gear group 73. Accordingly, the document 99 guided to the second duplex dedicated path 84 is reversed by the second duplex dedicated path 84 formed in a folded shape, and reaches the reading position 90 with the front side of the document facing downward. Guided and read by the scanner unit 25.

  Further, the triple roller 40 and the discharge roller 39 are driven via the second gear group 75. Accordingly, the document 99 passes through the discharge path 82 and is discharged to the discharge tray 24.

  In this double-sided reading mode, since the first clutch 58 is in the disconnected state, power transmission to the single-side dedicated pulley group 72 is interrupted, and the transport rollers 34 and 35 of the single-side exclusive path 81 are not driven. Therefore, the driving of the portion of the single-side exclusive path 81 through which the document 99 does not pass can be stopped, so that energy saving is excellent and noise can be reduced.

  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 document transport path 70, the transport rollers 34 to 36, 41 to 43, and the triples. The rollers 37 and 40, the first motor 201, the transmission gear group 71, the two clutches 58 and 66, and the control unit 110 are provided. On the document tray 23, a document 99 can be set. The separation unit 32 separates and conveys the originals 99 stacked on the original tray 23 one by one. The scanner unit 25 reads image information on the document 99. The document conveyance path 70 guides the document 99 so that only one side of the document 99 is read by the scanner unit 25 in the single-sided reading mode, and the document so that both sides of the document 99 are read by the scanner unit 25 in the double-sided reading mode. Guide 99. The conveyance rollers 34 to 36 and 41 to 43 and the triple rollers 37 and 40 convey the document 99 along the document conveyance path 70. The first motor 201 generates power for rotating the transport rollers 34 to 36 and 41 to 43 and the triple rollers 37 and 40. The transmission gear group 71 transmits the power generated by the first motor 201. The clutches 58 and 66 can switch whether the power of the transmission gear group 71 is transmitted to the conveying rollers 34, 35, and 41 to 43 or cut off. In the single-sided reading mode, the control unit 110 transmits the power generated by the first motor 201 to the conveying rollers 34 and 35 used when reading only one side, and the conveying roller 41 used only when reading both sides. The clutches 58 and 66 are controlled so as not to transmit to .about.43. In the double-sided reading mode, the control unit 110 transmits the power generated by the first motor 201 to the conveyance rollers 41 to 43 used only when reading both sides and is used only when reading only one side. The clutches 58 and 66 are controlled so that they are not transmitted to the conveying rollers 34 and 35.

  Accordingly, it is possible to provide the ADF type image scanner device 20 capable of switching between single-sided reading and double-sided reading. In addition, since it is possible to prevent power from being transmitted to the conveyance roller on the path not used for conveying the document, the load on the first motor 201 can be reduced, and the image scanner device 20 that has low power consumption and excellent quietness can be provided. realizable.

  In the image scanner device 20 of the present embodiment, the clutches 58 and 66 are electromagnetic clutches.

  Thereby, the image scanner apparatus 20 can be reduced in size and weight. Further, since it can be controlled by an electric signal, it can be controlled with a simple configuration.

  Further, the image scanner device 20 of the present embodiment has the following configuration. That is, the document conveyance path 70 includes a single-side exclusive path 81 and a double-side exclusive path (a first double-side exclusive path 83 and a second double-side exclusive path 84). The single-side exclusive path 81 transports the original 99 only when reading only one side of the original 99. In the duplex-only path, the original 99 is transported only when both sides of the original 99 are read. The feed rollers (conveying rollers 34 to 36, 41 to 43 and the triple rollers 37 and 40) that can be driven by the first motor 201 include one-side exclusive conveying rollers 34 and 35 installed in the single-side exclusive path 81; And double-side dedicated transport rollers 41 to 43 installed in the double-side dedicated path (second double-side dedicated path 84). In the single-sided reading mode, the control unit 110 transmits the power of the first motor 201 to the conveyance rollers 34 and 35 dedicated to one side, and the power of the first motor 201 to the conveyance rollers 41 to 43 dedicated to both sides. The clutches 58 and 66 are controlled so as to be disconnected. In the double-sided reading mode, the control unit 110 transmits the power of the first motor 201 to the conveyance rollers 41 to 43 dedicated to both sides, and the first motor 201 to the conveyance rollers 34 and 35 dedicated to one side. The clutches 58 and 66 are controlled so as to cut off the power.

  As a result, with a simple configuration for controlling the clutches 58 and 66, the transport rollers on the transport path not used for transporting the document 99 can be stopped according to the situation.

  Further, in the image scanner device 20 of the present embodiment, the duplex dedicated path includes a first duplex dedicated path 83 and a second duplex dedicated path 84. The first duplex dedicated path 83 guides the document 99 so that one surface of the document 99 separated by the separation unit 32 is read by the scanner unit 25. The second duplex dedicated path 84 inverts and guides the document 99 so that the scanner unit 25 reads the other surface of the document 99 that has been read on one surface through the first duplex dedicated path 83.

  As a result, by providing the first duplex dedicated path 83 and the second duplex dedicated path 84, it is possible to flexibly set the path through which the document 99 is conveyed during duplex scanning.

  In the image scanner device 20 of the present embodiment, the two clutches 58 and 66 are both installed in the vicinity of the junction 92 between the single-side exclusive path 81 and the double-side exclusive path (second double-side exclusive path 84). Yes.

  Thereby, the structure of the power transmission path including the transmission gear group 71 and the clutches 58 and 66 can be simplified.

  In the image scanner device 20 of the present embodiment, the power generated by the first motor 201 is read to transmit power to the transmission gear group 71 and the triple rollers 37 and 40 located near the reading position 90. The gear group 74 is transmitted separately.

  As a result, the triple rollers 37 and 40 located in the vicinity of the reading position 90 are directly driven without passing through the clutches 58 and 66, so that the play of the clutches 58 and 66 is not rotated when the triple rollers 37 and 40 rotate. Avoid adverse effects. As a result, blurring during reading of the document 99 can be suppressed, and distortion of the read image can be prevented.

  Further, in the image scanner device 20 of the present embodiment, the control unit 110 causes the current flowing through the first motor 201 when reading only one side of the document 99 to flow through the first motor 201 when reading both sides of the document 99. Control is made to be smaller than the current.

  As a result, when only one side of the document is read, power consumption during document conveyance can be saved. On the other hand, when reading both sides of the document, it is necessary to drive a large number of transport rollers including the transport rollers 41 to 43 of the second duplex exclusive path 84, so that a large amount of power is required compared to reading only one side. However, sufficient current can be supplied to generate that power.

  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-described embodiment, the single-side dedicated path 81 and the second double-side dedicated path 84 are configured to merge at the junction 92, but instead of this configuration, the single-side dedicated path 81 and the second double-side dedicated path 84 merge. It is possible to change to a configuration in which the document is guided to the reading position 90 through different paths so as not to be.

  In the above embodiment, in the single-sided reading mode, the driving of the transport rollers 41 to 43 in the second double-side exclusive path 84 is all cut off. However, the power may be cut off only to some of the transport rollers (for example, the transport rollers 41 and 42) and the power may be transmitted to the remaining transport rollers 43.

  Further, in the above embodiment, in the double-sided reading mode, the driving of the transport rollers 34 and 35 of the single-side dedicated path 81 is all cut off. However, the power may be cut off only to a part of the transport rollers (for example, the transport roller 34) and the power may be transmitted to the remaining transport rollers 35.

  Instead of the triple rollers 37 and 40, it is also possible to change so as to arrange a conveying roller having a normal configuration including one driving roller and one driven roller.

  In the above-described embodiment, the reduction optical system scanner unit 25 is used as the reading unit. However, instead of this, the reading unit may be changed to a configuration using a contact image sensor or the like. In the above embodiment, the scanner unit 25 is arranged in the main body 11, but it can be changed to a configuration in which the reading unit is arranged in the ADF. Thus, the configuration of the reading unit can be changed as appropriate according to circumstances.

  The configuration of the above embodiment is not limited to a copy facsimile multifunction machine, but can be applied to, for example, a single copy machine.

20 Image scanner device (image reading device)
21 ADF
25 Scanner unit (reading unit)
32 Separating section 34, 35 Conveying roller
36 Conveyance roller (feed roller)
37, 40 Triple roller (feed roller)
41-43 Conveyance roller (Feed roller dedicated to both sides)
58 1st clutch (clutch)
66 Second clutch (clutch)
70 Document transport path 71 Transmission gear group (power transmission unit)
74 Reading gear group (power transmission part)
81 One-side exclusive pass 83 First double-side exclusive pass 84 Second double-side exclusive pass 90 Reading position 110 Control unit 201 First motor (drive source)

Claims (7)

A document tray where documents can be placed,
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;
When reading only one side of the document, the document is guided so that only one side of the document is read by the reading unit, and when reading both sides of the document, both sides of the document are read by the reading unit. A document conveyance path for guiding the document,
A plurality of feed rollers for transporting the document along the document transport path;
A drive source for generating power for rotating the feed roller;
A power transmission unit for transmitting power generated by the drive source;
A clutch capable of switching whether to transmit or block the power of the power transmission unit to the feed roller;
When reading only one side of the document, the power generated by the drive source is transmitted to the feed roller used when reading only one side of the feed roller, and the feed roller used only when reading both sides. Controlling the clutch not to transmit to at least a part of
When reading both sides of the document, the power generated by the drive source is transmitted to the feed roller used only when reading both sides of the feed roller, and the feed roller used only when reading only one side. A control unit for controlling the clutch not to transmit to at least a part of
An image reading apparatus comprising: The image reading apparatus according to claim 1,
The image reading apparatus, wherein the clutch is an electromagnetic clutch. The image reading apparatus according to claim 1, wherein
The document transport path includes a single-side dedicated path for transporting the document only when reading only one side of the document, and a duplex-only path for transporting the document only when reading both sides of the document;
The feed roller includes a single-side dedicated feed roller installed in the single-side dedicated path, and a double-sided dedicated feed roller installed in the double-side dedicated path,
The controller is
When reading only one side of the original, the power of the drive source is transmitted to the single-side dedicated feed roller, and the clutch is set to shut off the power of the drive source to the double-side dedicated feed roller. Control
When reading both sides of the original, the power of the drive source is transmitted to the duplex dedicated feed roller, and the clutch is controlled to shut off the drive source power to the single-side dedicated feed roller. An image reading apparatus. The image reading apparatus according to claim 3,
The both-side dedicated path is
A first double-sided path for guiding the document so that one side of the document separated by the separation unit is read by the reading unit;
A second double-side dedicated path that inverts and guides the original so that the other side of the original read through the first double-side exclusive path is read by the reading unit;
An image reading apparatus comprising: The image reading apparatus according to claim 3 or 4,
The image reading apparatus according to claim 1, wherein the clutch is installed in the vicinity of a junction where the one-side dedicated path and the two-side dedicated path merge. An image reading apparatus according to any one of claims 1 to 5,
The power generated by the drive source is transmitted separately to the power transmission unit and a power transmission unit that transmits power to a feed roller arranged in the vicinity of the reading position of the document by the reading unit. A characteristic image reading apparatus. The image reading apparatus according to any one of claims 1 to 6,
An image reading apparatus, wherein a current flowing through the drive source when reading only one side is smaller than a current flowing through the drive source when reading both sides.

Images