JP4075788B2 - Automatic document feeder - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus having an ADF (automatic document feed) function, and in particular, an image reading configured such that image information on a first surface (front surface) and a second surface (back surface) can be continuously scanned by ADF. Relates to the device.

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a multifunction machine combining a facsimile machine and a copying machine function, an FBS (flat bed scanner) provided with a large-size platen for placing and reading a document of a book is read. In addition to the above, a sheet-through type ADF (automatic document feeder) that reads an image while conveying a sheet document is provided. In the ADF, after reading the first side of the double-sided document, the image is read on the second side while the document is reversed and returned through the switchback type conveyance path. . It has also been proposed that when the second surface is read, the sheet alignment operation can be satisfactorily performed so that the document to be switched back is not obliquely fed (see, for example, Patent Document 1). ).
Japanese Patent Laid-Open No. 11-263539

  However, the reverse roller mechanism is arranged on the upper part of the ADF even when using a mechanism for switching back the document on which the first surface has been read and feeding it toward the second surface. The combination of the sheet conveyance paths leading to the reversing unit is complicated. In addition, since the document discharge mode cannot be selected due to the configuration of the document transfer path, there are characteristics such as being unable to cope with various user requirements such as page alignment and reverse discharge, etc. Is required to set.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus that can easily select a document transport and discharge mode and can improve the readability of a double-sided document.

The present invention relates to an automatic document feeder. According to a first aspect of the present invention, there is provided a reading path that guides a document taken out from the document tray one by one to a reading unit, a first discharge path that guides the document that has passed through the reading path to a first discharge tray, An intermediate path that guides the original whose image has been read from the first surface via the reading path to the reversing tray, and the original that has passed the reversing tray are guided to the reading path. A document return path that enables reading of the second surface, a short-circuit path that guides the document that has passed through the reversing tray to the first discharge tray, and an entrance portion of the reversing tray are provided for forward and reverse rotation. A possible reverse roller, a second discharge path that linearly guides the document read by the reading unit from the reading path toward the second discharge tray, and the document conveyed through the reading path. First Comprising a first gate for branching the exhaust path, and reads the first surface of the original to be guided to the reversing tray from the document tray via the intermediate path and the read path, the said document intermediate path A mode in which the reversing tray guides to the first discharge tray via the short-circuit path and the first discharge path, the reading path, and the document discharge tray from the document tray via the first discharge path. A mode for reading the first surface of the document guided to the first discharge tray can be selected , and the document tray is transferred to the second discharge tray via the reading path and the second discharge path. The first surface of the document guided by the first gate can be read so as to be conveyed .
According to a second aspect of the present invention, there is provided a second gate that branches the document that has passed through the reading path into either the first discharge path or the intermediate path, and the document that has passed through the reversing tray. A third gate for branching to one of the document return paths, and the document transported by reversing the reversing roller are provided between the second and third gates and branch to the short-circuit path. And a fourth gate.

The invention of claim 3 is characterized in that the first discharge tray, the reversing tray, and the document tray are arranged in this order from the top to the bottom with a predetermined interval.
The invention according to claim 4 reads the first surface of the document guided by the second gate so as to be conveyed from the document tray to the reversing tray through the reading path and the intermediate path. And the second and third gates so as to be conveyed from the reversing tray to the first discharge tray via the document return path, the reading path, and the first discharge path. The second side of the original can be read.

  With the configuration as described above, by setting the double-sided original of the sheet on the original tray once, the images on the first side and the second side can be continuously read, and the original transport mechanism is simplified. It can be configured as an integrated mechanism. In addition, after reading the double-sided original, it is possible to arbitrarily select the mode for sending out the original, and it is possible to arbitrarily set the mode for discharging with the pages aligned, the mode for selecting the discharge tray, etc. Therefore, it is possible to easily cope with various requirements of the operator.

  The automatic document feeder described below can be provided in combination with an image forming apparatus having an arbitrary configuration, and can be particularly effective when creating a duplex copy using a duplex document. It becomes. In addition to the large-sized double-sided copying machine that is generally used as a conventional image forming apparatus that can make a double-sided copy, a duplex-compatible module is attached to a small-sized image forming apparatus. It is also possible to provide a small apparatus.

  The configuration of the apparatus of the present invention will be described according to the illustrated example. In the explanatory view of the image forming apparatus 1 shown in FIG. 1, an image forming apparatus 2 configured by combining an automatic document feeder 40 is configured as an apparatus capable of creating recording paper using an electrophotographic method. The apparatus main body 2 of the image forming apparatus 1 is provided with a paper feed tray 3 at the lowermost part thereof so that paper can be fed by a paper feed roller 4 toward a recording unit. In addition, a sheet feeding device capable of mounting one or a plurality of sheet feeding trays or the like can be separately combined in the lower part of the apparatus main body 2, and the operator can store different size sheets in the sheet feeding unit. It is also possible to easily respond to the request.

  Corresponding to the sheet conveyance path 7 arranged on one side surface of the apparatus main body 2, a recording unit 10 is provided in the upper part of the sheet feeding unit, and the recording unit records a toner image on the sheet. Then, fixing is performed through the fixing device 18 provided on the upper portion, and the created recording paper is discharged to the discharge tray 22. In the lower part of the recording unit 10, a sheet aligning device that aligns the sheet fed from the sheet feeding tray 3 by the sheet feeding roller 4 at the position of the merging unit in the sheet conveying path is provided. In the sheet aligning device, the leading end of the sheet is inserted into the nip portion of the registration roller device 6, a loop is formed on the sheet in a state where an additional feeding action is applied by the sheet feeding roller, and the leading end of the sheet is moved to the roller The nip portion is pressed so as to perform the alignment action. In the recording unit 10, the registration roller device 6 is driven to synchronize with the toner image formed on the photosensitive drum 11, and the sheet is fed out. The sheet is conveyed in an obliquely fed state in the recording unit. Control so that it is not.

  The recording unit 10 is provided with a charging unit 12, a writing unit 13, a developing device 16, a transfer unit 14, a cleaner 15, and the like around the photosensitive drum 11 according to a predetermined arrangement relationship. For the photosensitive drum 11 arranged in the recording unit 10, the surface of the photosensitive drum 11 is uniformly charged by the discharge from the corotron 12 as a discharging means, and then the information on the light scanned by the original is scanned. Is applied from the writing device 13 to form an electrostatic latent image on the surface of the photosensitive drum. Then, toner is supplied from the developing roller 17 of the developing device 16 to the electrostatic latent image to make it visible as a toner image, and the toner image is transferred to a sheet. At a position where the toner image is transferred to the paper, a predetermined value of voltage is applied to the transfer roller while conveying the paper so that the paper is sandwiched between the photoconductive drum and the transfer roller 14. The transfer to the sheet is performed in the same manner as in the case of an image forming apparatus using a conventional general electrophotographic system.

  The sheet on which the toner image has been transferred is sent to a fixing device 18 provided at the upper part thereof to be fixed. In the fixing device 18, a heating roller 19 and a pressure roller 19a are arranged inside the frame, and a predetermined nip pressure is set between both rollers, as in a conventionally known heat roller type fixing device. It is configured as follows. Then, toner is melted by the heat of the heat roller 19 with respect to the paper passing through the fixing device 18, and the melted toner is pressed by the pressure roller 19a from the back of the paper to be fixed on the paper. ing. The paper fixed as described above is sent to the discharge tray 22 by the discharge roller device 21 through the discharge path 20, and when a plurality of recording papers are continuously discharged, the image surface faces downward. Are stacked one after another. In addition, when the apparatus main body 2 is configured as a single-sided recording apparatus, the discharge roller apparatus 21 has a drive system configured to be driven only in one side.

  On the other hand, as will be described below, when the apparatus main body 2 is configured as an apparatus capable of performing double-sided recording, the discharge roller device 21 is not illustrated so that it can rotate forward and backward. Connected to the apparatus, the single-sided recording paper is returned to the paper feed unit through the reverse conveyance path, and an operation of making a double-sided copy is performed. In order to configure the apparatus capable of duplex copying, an optional reversing conveyance unit 30 is provided on one side (right side of the drawing) of the apparatus body 2 as auxiliary means (sheet reversing conveyance mechanism) for double-sided recording. It is configured to be wearable. When the reverse conveyance unit 30 as the optional unit is attached to form an apparatus capable of double-sided recording, the unit frame 31 is attached to the side of the apparatus main body 2.

  Note that any attachment means can be used to attach the main body frame 31 to the reverse conveyance unit 30, and a space for accommodating the manual feed tray 25 on the exposed surface side of the frame. Can be provided. Further, the reverse conveying unit 30 can be attached to the apparatus main body 2 using the support shaft 32 so that the outer portion of the frame 31 can be opened and closed. When the reverse conveyance unit 30 is provided, it is necessary to send a single-side recorded sheet from the discharge path 20 of the apparatus main body toward the reverse conveyance path 33. Therefore, at the end of the discharge path 20 of the apparatus main body, the discharge roller device 21 is a forward / reverse conveying roller, and a branch claw member (gate) 23 is provided so as to be able to swing around a support shaft 23a. Is sent toward the reversing path 33.

  The reversal conveyance unit 30 is provided with one or a plurality of conveyance roller devices 34 in the reversal conveyance path 33, and feeds the sheet from the reversal path 33 toward the aligning portion of the apparatus main body 2. After the front end is positioned, the paper is fed toward the back side recording. Further, when a paper jam occurs at the position of the reversing path 33, it is possible to easily perform the jam processing by opening the module outside the unit through the support shaft 32.

  In the state where the reversing conveyance unit 30 is attached, the manual feed tray 25 is provided so that it can be folded largely and leaned along the lower part of the unit. The manual feed tray 25 is provided with a second tray member 27 at the front end portion of a tray body 26 supported so as to be swingable with respect to the apparatus body via a support shaft 28 by using hinge means. The second tray member 27 can be used according to the paper size. Then, the paper set in the manual feed tray is sent out by the paper feed roller 29, and below the paper feed path 7 in the main body, the paper feed tray 3, the reverse conveyance path 33, and the paper feed path from the manual feed tray Are merged, aligned by the registration roller device 6, and sent to the recording unit.

  An automatic document feeder 40 is provided on the upper part of the apparatus main body 2. In the automatic document feeder 40, the scanning device 45 can be moved in the left-right direction in the figure inside the frame 42 of the reading device 41. Provided. A large platen 43 corresponding to a flat bed scanner (FBS) and a small platen 44 corresponding to an automatic document feeder (ADF) are provided on the upper portion of the frame 42 of the reading device 41. Then, a reading operation is performed on the book original set on the platen 43 while moving the scanning device 45 at a predetermined speed. Further, when reading using the ADF function, the document conveyed in the document conveyance path 55 of the ADF 51 is read while the scanning device 45 is stopped at the position of the small platen 44.

  The scanning device 45 provided so as to be movable in the frame 42 of the reading device 41 is provided so as to be reciprocally movable at a constant speed by a driving mechanism (not shown), and is set on the platen 43 using the FBS function. A document is read. The scanning device 45 is provided with a lamp 46 at the top of its moving frame, and a plurality of mirrors 47... Are combined in the frame so as to reflect light at a predetermined angle. The length of the reflected optical path is configured to be a predetermined length. Then, the light reflected by the multiple mirrors 47... Is imaged through a lens 48 on a CCD 49 as a photoelectric conversion means, and the image light is converted as a digital signal by the CCD. The image information obtained as described above can be written directly on the photosensitive drum using a writing device, or can be transmitted to another FAX device using the image transmission function of the FAX device. It is possible to cope with how to use.

  An ADF 50 as an automatic document feeder of the present invention is provided on the upper part of the image reading device 40 and as shown in FIG. The module including the ADF 50 can be opened and closed on the rear side of the frame 42 of the reading device 40 through a hinge portion (not shown) so that the upper device that also serves as a platen cover and the ADF 50 can be opened widely. It is supported. In the ADF 50 provided with the upper device, a document tray 51 provided with a paper feeding device 52, a reverse tray 57, and a discharge tray 62 are vertically stacked so that a set document can be taken out from below. It is arranged. In the ADF 50, a reading path 53 is arranged corresponding to the small platen 44 provided on the upper portion of the reading device 41, and the original is conveyed at a constant speed by the conveying roller devices 54 and 55 arranged on the upstream and downstream sides thereof. Thus, the document conveying apparatus is configured. In the paper feeding device 52 provided in the paper feeding unit from the original tray 51, a feeding roller 52a, a paper feeding roller 52b, and a pressing roller 52c for pressing the original are provided in combination, and the original set on the original tray 51 is placed below. Take one sheet at a time and send it to the reader.

  As described above, the document that has been sent out from the document tray 51 and has finished reading the first surface is guided to the gates G 1 and G 2, passes through the intermediate path 56, and is sent toward the reversing tray 57. A reversing roller 58 capable of rotating in the forward and reverse directions is provided at the entrance of the reversing tray 57, and the rear end portion of the document that is fed toward the reversing tray 57 after the reading of the first surface is reversed. The reversing roller 58 is driven in reverse at a predetermined timing while being nipped by the roller 58 so that the original is fed from the return path 59 toward the reading path 53. When the reading of the image on the second side of the document is completed, the image is sent toward the discharge tray 62 by the discharge roller device 63 through the discharge path 60. In addition to the three trays 51 and 57 and the discharge tray 62 arranged so as to overlap each other, a second discharge tray 66 is arranged in a straight line from the document tray 51 through the reading path 53.

  Gates G1 to G4 are provided at branch portions of the respective conveyance paths provided in the reading path 50, and each of the gates performs a switching operation of the document conveyance path by a driving means such as a solenoid. . The requirements such as the configuration of the drive source used for switching the document transport path are not particularly the gist of the present application, and any conventionally known technical means can be used. Description is omitted.

When reading an image of a double-sided original while inverting and conveying the original using the original conveying means described with reference to FIG. 2, the original conveying mode is an arbitrarily set reading as described below. And according to the discharge mode.
a: First, when images on both sides of a document are read and discharged toward the discharge tray 62, the document set on the document tray 51 is sent out one by one by the paper feeding device 52, and is conveyed along the conveyance path A. While reading the first surface, the original is conveyed from the intermediate path 56 toward the reverse tray 57. When transporting along the route A, it is guided by the gates G 1 and G 2 so as to pass through the transport paths 53 and 56.
b: Next, the paper is reversely conveyed through the return path 59 by the reverse roller 58 provided on the reverse tray 57, and is conveyed from the reading path 53 through the discharge path 60 to the discharge tray 62 along the path B. When the document is transported along the transport path B, the gate G2 is swung so as to close the intermediate path 56 and guides the document.

In the mode of reading an image on one side of the document, the document set on the document tray 51 is discharged from the reading path 53 toward the document tray 62 through the discharge path 60. When such a transport path is selected, the page of the document is changed. There is an inconvenience that it is reversed. Therefore, in order not to disturb the page of the document to be discharged to the discharge tray,
c: As shown in FIG. 4, the document read from the document tray 51 through the reading path 53 is transported along the transport path A and is transported so as to be temporarily accommodated in the reverse tray 57. In the middle of feeding toward the reversing tray, the reversing roller 58 is driven to rotate in the reverse direction, and is fed through the short-circuit path 61 according to the conveying path C via the gates G3 and G4 and discharged toward the discharge tray 62. Therefore, when such a conveyance mode is set, the page of the document is not disturbed.

In addition to performing the document transport operation between the three trays 51, 57, 62 arranged so as to overlap with each other, a second discharge is additionally provided on the side of the ADF 50 as shown in FIG. It is also possible to set the A1 mode in which the document is conveyed toward the tray 66.
d: When the second discharge tray 66 is provided, it is possible to set the mode for conveying the document linearly from the reading path 53 toward the second discharge tray 66 by switching the gate G1. Also, it can be used effectively even when a special paper document is conveyed without being bent. When the second discharge tray 66 is provided, it is possible to additionally provide the gate G1, the discharge path 65, and the second discharge tray 66 only when it is necessary. Further, the discharge tray can be provided so as to hang down from the side of the apparatus main body, and an arbitrary arrangement mode can be set.

  e: As described with reference to the path C in FIG. 4, in addition to the case where the conveyance mode is set so that the page is not disturbed in the original, the page on which the original image is displayed is in the reverse side. If it does not matter, it may be configured such that the mode for conveying the document can be set according to the conveyance path B in FIG.

  It should be noted that setting each document transport mode for the automatic document transport apparatus can be handled by providing a document transport mode selection button or the like on the control panel of the image forming apparatus, for example. Then, when the selection button is pressed, the conveyance path shown in the schematic diagram is illuminated so that the operator can easily confirm it, so that the conveyance path of the document can be confirmed and mistakes can be prevented. It becomes possible.

1 is an explanatory diagram illustrating a configuration of an image forming apparatus. It is explanatory drawing of the Example of ADF for both sides. FIG. 6 is an explanatory diagram of a state of a document conveying device in ADF. It is explanatory drawing of the 2nd Example of an original conveying apparatus. It is explanatory drawing of another Example of an original conveying apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus, 2 Apparatus main body, 3 Paper feed tray, 4 Paper feed roller, 6 Registration roller apparatus, 7 Paper conveyance path, 10 Recording part,
11 photosensitive drum, 12 charging means, 13 writing device,
14 transfer roller, 15 cleaner, 16 developing device,
17 developing roller, 18 fixing device, 20 discharge path,
21 discharge roller, 22 discharge tray, 23 gate,
25 Manual feed tray, 30 Duplex unit, 33 Reverse path,
40 reading device, 43/44 platen, 45 scanning device,
48 lenses, 49 CCD, 50 ADF, 51 document tray,
52 paper feeding device, 53 reading path, 54/55 transport roller device,
56 intermediate path, 57 reverse tray, 58 reverse roller,
59 return path, 60 discharge path, 61 short circuit path,
62, 66 discharge tray, 63 discharge roller device, 65 second discharge path.

Claims (4)

A reading path for guiding the documents taken out from the document tray one by one to the reading unit;
A first discharge path for guiding the document that has passed through the reading path to a first discharge tray;
An intermediate path for guiding the original, from which an image has been read from the first surface via the reading path, to a reversing tray;
A document return path that guides the document that has passed through the reversing tray to the reading path and enables the reading unit to read the second surface of the document;
A short-circuit path for guiding the document that has passed through the reversing tray to the first discharge tray;
A reversing roller that is provided at the entrance portion of the reversing tray and is capable of rotating in the forward and reverse directions;
A second discharge path for linearly guiding the document read by the reading unit from the reading path toward the second discharge tray;
A first gate for branching the document conveyed on the reading path to the second discharge path;
With
The first surface of the document guided from the document tray to the reversing tray is read through the reading path and the intermediate path, and the document is scanned with the intermediate path, the short-circuit path, and the first discharge path. , A mode for guiding from the reverse tray to the first discharge tray via,
A mode for reading the first surface of the document guided from the document tray to the first discharge tray via the reading path and the first discharge path;
Is selectable ,
Reading the first surface of the document guided by the first gate so as to be conveyed from the document tray to the second discharge tray via the reading path and the second discharge path; An automatic document feeder characterized by being possible . A second gate for branching the document passing through the reading path to either the first discharge path or the intermediate path;
A third gate for branching the document that has passed through the reversing tray to either the intermediate path or the document return path;
Is provided between said second and third gates, the document conveyed by reversing the reverse roller, and a fourth gate for branching to the short-circuit path,
The automatic document feeder according to claim 1, further comprising:   3. The automatic document conveyance according to claim 1, wherein the first discharge tray, the reverse tray, and the document tray are arranged in this order from the top to the bottom with a predetermined interval. apparatus. Reading the first surface of the document guided by the second gate so as to be conveyed from the document tray to the reversing tray via the reading path and the intermediate path;
The document guided by the second and third gates so as to be conveyed from the reverse tray to the first discharge tray via the document return path, the reading path, and the first discharge path. Reading the second side of
4. The automatic document feeder according to claim 2, wherein the automatic document feeder is capable of performing the following operations.

Images