JP3972538B2 - Paper transport device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet conveying apparatus that guides a sheet through a curved conveyance path and sends the sheet toward a reading unit, and in particular, improves the sheet conveying performance of a main roller that imparts a conveying action to the sheet at the curved unit. The present invention relates to a sheet transport apparatus.
[0002]
[Prior art]
In an image forming apparatus or the like, the sheets placed on the supply tray are separated and fed one by one and conveyed toward a processing unit such as a reading unit or a printing unit by a conveyance roller device provided in a conveyance path. Means are used. In order to send out the paper from the tray, a pickup roller is disposed at a position corresponding to the tray, and the paper taken out by the pickup roller is separated one by one by a paper separating device and directed toward the reading unit of the image reading device. It is configured to send in. In order to supply the sheets one by one toward the reading unit, a sheet separating device is disposed downstream of the pickup roller, the retard roller is rotated in the opposite direction to the sheet feeding direction, and is rotated in the sheet feeding direction. It is arranged so as to face the separate roller.
[0003]
When the image reading apparatus is combined with a flat bed scanner mechanism (FBS) and disposed on the upper part of the image forming apparatus, the sheet conveyance path of the image reading apparatus is formed in a substantially U shape in the horizontal direction, It is necessary to provide the apparatus in a small size so that the apparatus is curved with a very small radius. In the U-shaped conveyance path, a curved guide having substantially the same diameter as that of the large-diameter conveyance roller is arranged, and the sheet is guided and conveyed between the outer guide plates arranged opposite to each other. Thus, the sheet conveying action in the curved path can be performed in a good state.
[0004]
The large-diameter conveying roller disposed on the curved path of the sheet conveying device is one in which one or a plurality of rollers are arranged in a skewered manner with a predetermined interval, and a curved guide is provided between the rollers. It is necessary to arrange. Therefore, as shown in FIG. 7, the large-diameter conveying roller 20A arranged on the curved path is constituted by a wide roller supported by the drive shaft 22, and an opposing wide pinch roller 24A is provided on the shaft 24B. It can be considered that the sheet is nipped between the rollers 20A and 24A. As described above, in the paper conveyance device in which the wide rollers 20A and 24A are arranged to face each other, the configuration of the rollers can be simplified, and the assembly work to the paper conveyance device can be easily performed. It is considered that the advantage of assembly work that it can be performed is exhibited.
[0005]
[Problems to be solved by the invention]
When a wide roller as shown in FIG. 7 is used, the large-diameter conveying roller 20A supported by the drive shaft 22 is supported by a shaft having a large rigidity. Even if a large nip pressure is set, the roller itself is not deformed. However, the pinch roller 24A supported by the shaft 24B has a large nip pressure because the support shaft 24B has a relatively low rigidity and the structure of the roller itself is also relatively thin. When trying to set, there is a problem that it is easily deformed. Further, since the pinch roller 24A is a resin molded product, there is a problem that when the roller width is widened, there is a problem that it is likely to be formed into a drum shape or a drum shape, and as a countermeasure, it can be divided into a plurality of narrow roller members. Conceivable. The wide pinch roller 24A is divided into a roller member together with the large-diameter conveying roller 20A. If only the pinch roller 24A is divided and the large-diameter conveying roller 20A remains wide, the divided pinch roller 24A This is for the purpose of dealing with the problem that the sheet may enter a gap formed between the unit bodies and the document is likely to be wrinkled.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide a paper transport device that can prevent wrinkles and the like from occurring in a nip portion of a paper and can perform the paper transport and guide operations at a curved portion of a paper transport path. .
[0007]
[Means for Solving the Problems]
The present invention relates to a sheet conveying apparatus that has a curved sheet conveying path and conveys a sheet fed to the sheet conveying path. The invention according to claim 1 of the present invention is a sheet conveying apparatus that has a curved sheet conveying path and conveys the sheet fed into the sheet conveying path , and includes a plurality of narrow first roller members. A large-diameter conveying roller used for conveying a sheet on a curved path on the sheet conveying path, and a plurality of guide members made of resin and having a cylindrical shape having substantially the same diameter as each first roller member. A cylindrical guide capable of disposing each first roller member in a roller space provided between each guide member, and a plurality of narrow second roller members, A pinch roller that nips the paper with a roller, and a rib for paper guide that is integrated with the cylindrical guide and is disposed between the first roller member, Each of the plurality of second roller members has a corresponding first row. Characterized that you have been disposed opposite to the member. As a result, the paper can be conveyed while preventing the paper from being wrinkled.
[0008]
Further, the invention of claim 1, by those of the narrow by dividing the peak Nchirora, as in the case of constituting the wide roller of width, can be prevented as a drum-shaped or drum-shaped, the conveying action Can demonstrate well. Further, the invention of claim 1, together with the obtained reliably performs guidance of the paper, the number of auxiliary components is not increased.
The invention of claim 2 further includes a drive shaft that supports the large-diameter conveyance roller, and an auxiliary roller that is supported by the drive shaft, and the large-diameter conveyance roller corresponds to a small-size document. The auxiliary roller is supported on one side from the center in the axial direction of the drive shaft, and the auxiliary roller is arranged in the axial direction of the drive shaft to assist the conveyance by the large-diameter conveyance roller when conveying a large-size document. It is characterized by being supported from the center to the other side .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The configuration of the sheet conveying apparatus provided with the sheet conveying apparatus of the present invention will be described according to the illustrated example. The example shown in FIG. 1 describes the configuration of an automatic document feeder (ADF) 1 that is used in combination with a facsimile machine or an image forming apparatus and used to read an image of a document. In the automatic document feeder 1, the paper is conveyed through a conveyance path configured in a substantially U shape in the horizontal direction. The conveyance path includes a conveyance path 14 from the insertion port 14a, a curved path 19, and The document image is read by the reading device at the position of the platen 29 which is composed of the discharge path 25 connected to the discharge tray 72 and is arranged below the curved path 19. In the automatic document feeder 1, an intermediate frame 30 and an upper frame 3 are provided in combination with a base frame 2 disposed at the top of the image forming apparatus, and the upper frame 3 is centered on a support shaft 4. The intermediate frame 30 is provided so as to be swingable about the shaft 18 of the driving roller 17 of the transport roller device 15.
[0010]
In the example shown in FIG. 1, the pickup roller 5 supported by the arm 6 positioned at the paper insertion opening 14a, the paper separating device 10, the transport roller device 15, and the large roller are used to transport the paper in the paper transport path. A diameter conveying roller 20, a plurality of pinch rollers 24 and 23 a, and a discharge roller device 26 are disposed. Among the rollers, the large-diameter conveying roller 20 functions as a main conveying roller in the embodiment described below, and bears the sheet conveying action in the curved path 19. Further, the upper frame 3 includes a pickup roller 5 for taking a sheet from the tray, a separation roller 11 of the sheet separating apparatus 10, a pinch roller 16 of the conveying roller apparatus 15, and a large-diameter conveying roller (main conveying roller) 20. A pinch roller 24 is provided. The two pinch rollers 16 and 24 are attached to a roller support frame 8 supported by a stay 7 disposed on the upper frame 3 via an urging spring and a support arm member (not shown). , It is pressed against the corresponding drive roller with a constant pressing force. Further, the roller support frame 8 is provided with a guide plate 9 facing the large-diameter roller 20 of the curved path 19 to guide the paper in the curved path 19.
[0011]
The intermediate frame 30 includes an upper cover 35 as a lower guide member of the paper insertion opening 14a connected to the document tray 71, a retard roller 12 of the paper separating device 10, a driving roller 17 of the transport roller device 15, and a discharge roller. A drive roller 28 of the device 26 is provided. Further, the base frame 2 is provided with a large-diameter conveying roller 20 for performing a conveying action at the curved portion 19 of the sheet conveying path 6, a pinch roller 23a, and a pinch roller 27 of the discharge roller device 26, and the base portion The frame 2 is provided with a reading plate and a guide plate member for the transport path on the discharge side. In the apparatus having the above-described configuration, when the paper jam processing in the paper transport path, the adjustment of the nip pressure of the nip portion of the transport roller device 15, and other maintenance are performed, the upper frame is sequentially opened. By doing so, the sheet conveyance path is opened or each component is exposed so that the operation can be performed.
[0012]
In the automatic document feeder 1, when transporting a sheet along the sheet transport path, the sheet is taken in by the pickup roller 5 arranged corresponding to the tray connected to the sheet insertion port 14a, and the transport path Send it to 14 Then, a separating action is applied to the sheet between the separation roller 11 and the retard roller 12 of the sheet separating apparatus 10, and only one sheet is fed toward the conveying roller apparatus 15. The sheet conveyed by the conveying roller device 15 is nipped between the large-diameter conveying roller 20 and the pinch roller 24 in the curved path 19 of the sheet conveying path, passes through the reading unit of the platen 29, and is connected to the pinch roller 23a. The paper is fed toward the discharge tray 72 by the discharge roller device 26 disposed at the end of the discharge path 25 through the nip portion.
[0013]
The retard roller 12 of the paper separating device 10 is provided with a pressing force adjusting mechanism 45 for adjusting the nip pressure between the retard roller 12 and the separating roller 11, and the paper separating action in the paper feeding device. The nip pressure between both rollers can be adjusted according to the state of implementation. In the pressing force adjusting mechanism 45, one end of the adjusting arm 46 with the shaft of the pinch roller 28 of the discharge roller device 26 as a fulcrum is brought into contact with the lower surface of the shaft of the retard roller 12, and the other end of the adjusting arm 46 is contacted. By adjusting the pressing force of the spring 47 arranged in the section, the force for pushing up the shaft of the retard roller 12 from the lower surface can be adjusted.
[0014]
The intermediate frame 30 of the automatic document feeder 1 is configured by combining a frame 31 made of sheet metal and an upper cover 35 as a guide plate disposed on the frame body 31, and the driving roller 17 of the carry roller device 15. The shaft 18 is provided so as to be swingable. In order to drive the retard roller 12 disposed on the intermediate frame 30 and the drive roller 28 of the discharge roller device 26, a gear transmission mechanism (not shown) is provided that transmits drive from the drive shaft 18 of the transport roller device 15. Yes. When performing the sheet separating action, the retard roller 12 is rotated so as to be conveyed in the opposite direction with respect to the sheet conveying direction by the feed roller 11 with respect to the axis of the retard roller 12.
[0015]
A curved path 19 partitioned by a large-diameter transport roller 20 and a guide plate 9 is disposed in the downstream portion of the transport path 14 including the transport roller device 15. In order to guide the paper discharged from the nip portion of the transport roller device 15 toward the curved path 19, a guide member 40 and a guide film 41 are provided as paper guide means, and the paper fed from the transport roller device 15 is Smooth guidance toward the curved road. The guide member 40 as the sheet guide means has a downward U-shaped support member 43 attached to the shaft 18 of the driving roller 17 of the transport roller device 15, and the guide member 40 is supported by the support member 43. .
[0016]
The curved path 19 is formed by a guide plate 9 and a large-diameter conveying roller 20, and the large-diameter conveying roller 21 is provided in combination with a cylindrical guide 50 configured as shown in FIGS. It is done. As shown in the plan view of FIG. 2, the cylindrical guide 50 is configured as a unit in which a plurality of guide members 51, 51 a... Are integrated via a connecting portion by a connecting shaft 56 at the end. In the roller spaces 52, 52a... Provided between the guide members, the rubber roller 21a and the free roller 21 are respectively disposed. For example, the maximum size of paper that can be conveyed is A3 size. In the case of the A4 size paper, a large-diameter conveyance roller (main conveyance roller) 20 composed of three rubber rollers is arranged in correspondence with the center of the vertical feeding of the A4 size paper. The auxiliary rubber roller 21a is arranged at a predetermined interval, and the free roller 21 is arranged at an arbitrary position with respect to other parts. The configuration of the large-diameter conveyance roller (main conveyance roller) 20 will be described later with reference to FIG.
[0017]
In the cylindrical guide 50, the plurality of guide members 51... Are integrally molded using a plastic material together with the metal connecting shaft 56. In order to position the connecting shaft 56 in a mold, the gaps 53. Are arranged at predetermined intervals, but this portion does not exhibit a special action. Further, fixing brackets 58 and 58 provided with screw holes 58a are disposed at both ends of the cylindrical guide 50, and the fixing bracket 58 is positioned with respect to a support portion of a main body frame (not shown). The cylindrical guide 50 corresponding to the large-diameter conveying roller 20 and the guide plate 9 is positioned by screwing through the screw hole 58a. Ribs 54 are formed at predetermined intervals on the surface of the cylindrical guide 50 on which the paper slides so as to reduce friction with the paper. It is not necessary to fix and hold both ends of the connecting shaft 56 that supports the guide members 51 in a skewered manner with respect to the main body frame. You may extend to a side part and you may fix to the latching | locking part provided in the main body frame.
[0018]
The example shown in FIG. 3 shows a configuration of a main conveyance roller (large-diameter conveyance roller) 20 disposed in a curved portion of the conveyance path. The large-diameter conveyance roller 20 has an A4 size as shown in FIG. Corresponding to the vertical feeding of the paper, the paper is arranged at a substantially central portion in the paper width direction, and performs a paper transporting action along the curved path 19 together with the auxiliary rollers 21 and 21a. The large-diameter conveying roller 20 is configured by uniting three narrow roller members 20a to 20c in parallel with the shaft 22, and between these roller members, As shown in FIG. 1, ribs 55 and 55 a are provided so as to protrude from the paper discharge side of the cylindrical guide, and the paper is guided toward the discharge path 25. Also, in the pinch roller 24 disposed with respect to the large-diameter conveying roller 20, the narrow roller members 24a to 24c are skewered on the shaft 24B in correspondence with the roller members 20a to 20c of the large-diameter conveying roller. The unit is provided as a unit.
[0019]
As described above, each of the roller members 20a to 20c of the large-diameter conveying roller 20 and the roller members 24a to 24c of the pinch rollers facing each other forms a nip portion for each sheet. As described above, the roller members 24a to 24c of the narrow pinch rollers are each configured as a resin molded product, so that when the roller members 24a to 24c are molded, a drum shape or a drum shape is formed. Therefore, the sheet can be conveyed while being nipped so as to correspond to each of the roller members 20a to 20c of the large-diameter conveying roller having a narrow width. In addition, it is possible to satisfactorily maintain the sheet conveyance state when the sheet is conveyed while nipping between the large-diameter conveyance roller 20 and the pinch roller 24.
[0020]
The cylindrical guide 50 provided in combination with the large-diameter conveying roller 20 is configured as shown in the side view of FIG. 4, and the cylindrical guide 50 is arranged with respect to the drive shaft 22 of the large-diameter conveying roller 20. The shaft support 59 is supported and positioned. The shaft support 59 is engaged with the drive shaft 22 and is fixed with screws via the fixing bracket 58, and the surface of the cylindrical guide 50 is positioned on the conveying surface of the large-diameter conveying roller 20 to convey the paper. It is comprised so that a guide effect | action can be performed. Further, as shown in FIG. 4, the connecting shaft 56 for connecting the plurality of guide members 51... Constituting the cylindrical guide 50 is disengaged from the position where the large-diameter conveying roller 20 is arranged, so that the paper conveying path Since a position that does not get in the way is selected and arranged, it is preferably provided in the vicinity of the connection portion between the curved path 19 and the discharge path 25. By forming the connecting portion corresponding to the connecting shaft 56 in a curved shape as shown in the drawing, it is possible to satisfactorily guide the sheet from the curved path toward the discharge path.
[0021]
The example shown in FIG. 5 shows a state in which anti-slip processing is performed on the surface of the connecting shaft 56 at a predetermined position in order to fix and hold the guide members 51, 51 a. As the anti-slip 57 provided on the connecting shaft 56, for example, knurling can be performed on the shaft, but by providing irregularities of any other shape, the connecting shaft 56 and the guide members 51, 51a. .. Can be fixed together and fixed so that the guide members do not rotate unexpectedly with respect to the shaft. Further, when the plastic material is injection-molded by holding the connecting shaft 56 in a molding die, as shown in FIG. 2, the portion of the gap 53 formed after the molding is used for molding. The molding work can be performed while being supported by the protrusions of the mold.
[0022]
As shown in FIG. 1, the cylindrical guide 50 in which the guide members are integrally held with respect to the connecting shaft 56 and the fixing brackets 58 are provided at both ends, is connected to the large-diameter conveying roller 20 in the curved path 19. They can be arranged in combination and configured as an inner guide plate. Then, while the sheet is slid on the rib 54 protruding from the surface of the cylindrical guide 50, the large-diameter conveying roller 20 and the auxiliary rollers 21 and 21a convey the sheet, and the platen 29 reads the sheet on the reading unit. Can be passed at a constant speed to cope with the effect of image reading. Further, since the large-diameter conveying roller is divided, ribs 55... Are inserted between the roller members 20a to 20c of the large-diameter conveying roller 20, and the original read by the rib 55 is discharged. It can be sent out toward the road 25.
[0023]
The example shown in FIG. 6 shows the configuration of the reading device 60 provided integrally with the image forming apparatus. The scanning unit frame 61 is provided with a scanning device 63. The scanning device 63 includes a full-rate carriage 64 provided with a lamp 64a and one mirror m1, and two opposing mirrors, as in a conventionally used image reading device such as a copying machine. A half-rate carriage 65 in which m2 and m3 are arranged is provided in combination. The document reading information is transmitted to the CCD 69 via the lens 68, and the optical signal is converted into an electrical signal and transmitted to the image information processing unit of the image forming apparatus. In the scanning device, in order to drive the full-rate carriage 64 and the half-rate carriage 65, drive pulleys 66 and 66a having a diameter of 2: 1 are arranged coaxially, and wires are wound around the respective drive pulleys. A mechanism for moving the two carriages in conjunction with each other is provided via 67 and 67a.
[0024]
On the upper part of the frame 61, a book original is placed, and a platen 62 corresponding to the operation as an FBS (flatbed scanner) and an ADF (automatic document feeder) are placed below the document feeder. A platen 29 to be arranged is provided. With respect to the platen 62, the upper opening / closing frame 70 is opened to set a document, and the frame 70 is closed so that the platen cover 73 presses the image surface of the document against the upper surface of the platen 62. Scan. For the original set on the platen 62, the full-rate carriage 64 of the scanning device 63 reciprocates by the length in the scanning direction of the original in accordance with detection information of a sensor (not shown), and the half-rate carriage 65 is moved. The image information is read while moving at half the speed of the full rate carriage 64, and an image signal is output from the CCD 69. Further, when scanning a sheet document using the document tray 71, an image is conveyed while the document is conveyed through a conveyance path provided in a document conveyance unit as an ADF in a state where the scanning device is fixed to the platen 29. The reading operation is performed.
[0025]
When scanning the document set on the document tray 71 using the reading device 60, the controller is operated by a detection signal from a detection unit (not shown) that the document is set on the document tray 71. Alternatively, it is performed by inputting a command for performing scanning using the document conveying section to the control panel. In response to the read command signal, the full-rate carriage 64 of the scanning device 63 is stopped at a position corresponding to the platen 29, and the half-rate carriage 65 is moved to the left end of the scanning unit frame 63, so that the document tray A document is conveyed one by one from the 71 to the U-shaped conveyance path, and an image of the document is read by the platen 29. Therefore, in the scanning device arranged in the scanning unit frame 61, the scanning device can be set in correspondence with the two platens 62 and 29, and an operation for reading an arbitrary document can be performed. It can be used to transmit image information, or can be printed on recording paper using the function of a copying machine.
[0026]
【The invention's effect】
Since the apparatus according to the present invention is configured as described above, the main conveying roller among the large-diameter conveying rollers arranged in the curved sheet conveying path is arranged with a narrow roller member with respect to a plurality of driving shafts. Since a pinch roller having the same width as the main transport roller is arranged to face the main transport roller, the pinch roller facing the main transport roller is divided. As a result, the sheet can be conveyed while preventing wrinkles and the like from occurring on the sheet. Moreover, since the pinch roller is a resin molded product, the pinch roller is divided into small ones to prevent the drum or drum from being formed like a wide roller. Can be carried out well. Further, since the sheet guide ribs are inserted between the roller members of the main conveying rollers so as to be integral with the cylindrical guide, the sheet can be guided reliably and the number of auxiliary parts can be reduced. There is no increase.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of the structure of a paper transport apparatus to which the configuration of the present invention can be applied.
FIG. 2 is a plan view showing a relationship between a cylindrical guide and a roller of a large diameter conveying roller.
FIG. 3 is an explanatory diagram showing a configuration of a large-diameter conveying roller and a pinch roller.
FIG. 4 is a side view of a cylindrical guide.
FIG. 5 is an explanatory diagram showing a relationship between a guide member and a connecting shaft.
6 is an explanatory diagram of an example in which the apparatus of FIG. 1 is combined with an image reading apparatus.
FIG. 7 is an explanatory diagram showing a configuration of a roller member arranged on a curved path.
[Explanation of symbols]
1 automatic document feeder, 2 base frame, 3 upper frame,
5 Pickup roller, 9 Guide plate,
10 paper separating device, 11 feed roller,
12 retard roller, 14 transport path, 15 transport roller device,
16 pinch rollers, 17 drive rollers, 18 axes,
19 curved path, 20 large-diameter conveying roller, 21 conveying roller,
22 drive shaft, 23/24 pinch roller, 25 discharge path,
26 discharge roller device, 29 platen, 30 intermediate frame,
31 frame body, 35 upper cover, 40 guide member,
41 guide film, 43 support member, 50 cylindrical guide,
51 Guide member, 52 Space for roller, 53 Clearance,
54/55 rib, 56 connecting shaft, 57 non-slip part,
58 bracket for fixing, 59 shaft support member, 60 reader,
62 platen, 64 full rate carriage,
65 half-rate carriage, 66 drive pulley,
67 wires, 68 lenses, 69 CCD,
71 Document tray, 72 discharge tray.

Claims (2)

A paper transport device that has a curved paper transport path and transports the paper fed into the paper transport path,
A plurality of first roller members having a narrow width, a large-diameter conveying roller used for conveying a sheet in a curved path on the sheet conveying path;
It has a plurality of guide members that are made of resin and have a cylindrical shape substantially the same diameter as each first roller member, and each first roller member can be arranged in a roller space provided between each guide member A cylindrical guide,
A plurality of second roller members having a narrow width, and a pinch roller for nipping the paper with the large-diameter conveying roller;
A sheet guide rib which is integrated with the cylindrical guide and is disposed between the first roller members;
With
The plurality of each of the second roller member, the sheet conveying apparatus characterized that you have been disposed to face the corresponding first roller member. A drive shaft for supporting the large-diameter conveying roller;
An auxiliary roller supported by the drive shaft;
Further comprising
The large-diameter conveying roller is supported on one side of the center in the axial direction of the drive shaft in order to correspond to a small-size document,
Said auxiliary roller to assist in conveying the by the large-diameter feeding roller in transporting the original large size, claims, characterized that you have supported the central than at the other side in the axial direction of the drive shaft 2. The paper conveying apparatus according to 1.

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