JP4061790B2 - Paper guide and paper transport device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet conveying apparatus that reads a sheet fed from a supply tray through a reading unit, and a sheet guide that guides the sheet toward a curved conveying path.
[0002]
[Prior art]
In an image forming apparatus or the like, a unit that separates and feeds sheets placed on a supply tray one by one and conveys them toward a processing unit by a conveyance roller device provided in a conveyance path is 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]
In the case where the image reading device is configured as a miniaturized device and disposed in the upper part of the image forming device in combination with a flat bed scanner mechanism (FBS), the sheet conveying path of the image reading device is set to a substantially U It is necessary to provide a mechanism that forms a letter shape and feeds the paper with a very small radius. In the U-shaped conveyance path, a guide is provided around the intermediate frame to guide the paper, and the intermediate frame supports the retard roller of the paper separating device and is arranged on the upper frame. A nip pressure of a predetermined value is set between both rollers. In the elastic pressing means arranged with respect to the retard roller, a means for adjusting the pressing force is provided so that the nip pressure can be adjusted at any time, so that double feeding does not occur on the fed paper.
[0004]
[Problems to be solved by the invention]
In the paper transport path, a paper guide is disposed between the transport roller device and the large-diameter driving roller disposed in the curved path, and the paper fed from the transport roller device is guided toward the curved path through the guide. To do. The paper guide is a plastic molded product and is narrow in the paper transport direction but is configured to be long corresponding to the width of the paper transport path. However, the guide is controlled by molding conditions and pressure applied during transportation. Are easily deformed, and there is a problem that irregularities and the like are formed in an unexpected part when guiding the sheet by incorporating it in the apparatus. When the paper guide surface of the paper guide is not accurately set, for example, when the downstream guide surface protrudes from the upstream guide surface (a reverse step portion is formed). However, there is a disadvantage that the paper is caught by the protruding portion and a jam occurs.
[0005]
The present invention is intended to solve the problem of the paper conveyance path guide as described above, so that the paper guide disposed in the upstream portion of the curved path can be bent and attached so that the central portion is lowered, The object of the present invention is to make it possible to satisfactorily perform the sheet guiding operation.
[0006]
[Means for Solving the Problems]
The present invention relates to a guide member provided in a paper conveyance path. According to a first aspect of the present invention, there is provided a paper guide for further guiding the paper guided by the guide member provided in the upstream portion in the paper transport direction in the paper transport path by the guide member provided in the downstream portion thereof. When both ends of the guide member in the downstream portion are screwed to the frame of the apparatus, an intermediate portion in the width direction of the guide surface of the guide member in the downstream portion with respect to the sheet conveying direction is caused by stress at the time of screw tightening. It is configured to be forcibly deformed in a direction away from the paper path surface . Accordingly, it is possible to prevent the upstream end portion of the guide member from protruding, and it is possible to prevent the sheet from jamming in the sheet conveyance path.
[0007]
According to a second aspect of the present invention, mounting surfaces are provided at both ends of the paper guide, and the mounting surface is an inclined surface that curves the entire guide downward with respect to a horizontal mounting surface formed on the apparatus main body. It is characterized by having. Therefore, even if the paper guide is curved upward so as to bend upward due to molding conditions or the like, the curved state of the paper guide can be reduced and the paper can be guided toward the curved path.
[0008]
The invention of claim 3 is characterized in that a paper guide for guiding the paper is provided in a curved paper conveyance path disposed between the supply tray and the discharge tray. Even if the paper guide is curved downward, it can be mounted on the apparatus with the curved state corrected by the guide support.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The configuration of the paper transport device provided with the paper guide of the present invention will be described according to the example shown in the drawing. 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 20, and The document image is read by the reading device at the position of the platen 23 formed of the discharge path 24 connected to the discharge tray 72 and disposed below the curved path 20. 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 via the shaft 18 of the driving roller 17 of the transport roller device 15.
[0010]
In the example shown in FIG. 1, a pickup roller 5 positioned at the paper insertion opening 14a, a paper separating device 10, a transport roller device 15, a large-diameter drive roller 21 and a plurality of rollers are provided to transport the paper in the paper transport path. The pinch rollers 22 and 22a and the discharge roller device 25 are arranged. Among the rollers, the upper frame 3 has a pickup roller 5 for taking in paper from the tray, a separation roller 11 of the paper separating device 10, a pinch roller 16 of the conveying roller device 15, and a large-diameter driving roller 21. A pinch roller 22 is provided. The two pinch rollers 16 and 22 are attached to a roller support frame 8 supported by a stay 7 arranged on the upper frame 3 via a biasing spring and a support arm member (not shown). The corresponding drive roller is pressed with a constant pressing force. Further, the upper frame 3 is provided with a guide plate 9 facing the large-diameter roller 21 of the curved path 20 to guide the paper in the curved path 20.
[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 driving roller 27 of the device 25 is provided. Further, the base frame 2 is provided with a large-diameter driving roller 21 and a pinch roller 22a for performing a transport operation in the curved portion of the paper transport path 6, and a pinch roller 26 of the discharge roller device 25, and the base frame In 2, a reading plate and a guide plate member for the conveyance path on the discharge side are arranged. 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 carrying a paper along the paper carrying path, the paper is taken in by the pickup roller 5 arranged corresponding to the tray 71 connected to the paper insertion opening 14a, and carried. It sends in toward the road 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 transported by the transport roller device 15 is nipped between the large-diameter driving roller 21 and the pinch roller 22 at the curved portion 20 of the sheet transport path, passes through the reading unit of the platen 23, and contacts the pinch roller 22a. Through the nip portion, the paper is sent out toward the discharge tray 72 by the discharge roller device 25 provided with the drive roller 27 and the pinch roller 26 facing each other from the discharge path 24. Further, a pressing force adjusting mechanism (not shown) is arranged for the retard roller 12 of the paper separating device 10 in order to adjust the nip pressure with the separating roller 11, The nip pressure between the two rollers can be adjusted in accordance with the state of the sheet separating action in the apparatus.
[0013]
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 27 of the discharge roller device 25, a gear group for transmitting drive from the drive shaft 18 of the transport roller device 15 is provided. Then, when performing the sheet separating action, the retard roller 12 is rotated with respect to the shaft 13 of the retard roller 12 so that the retard roller 12 is conveyed in the opposite direction with respect to the sheet conveying direction by the separate roller 11.
[0014]
A curved path 20 defined by a large-diameter driving roller 21 and a guide plate 9 is disposed downstream of the conveyance path 14 including the conveyance roller device 15 and is discharged from a nip portion of the conveyance roller apparatus 15. In order to guide the paper smoothly toward the curved path, paper guide means is provided. As shown in FIG. 2, the sheet guide means is configured by combining a support member 50 supported by the shaft 18 of the driving roller 17 of the transport roller device 15 and a guide member 40 for guiding the sheet. Yes. The main body 51 of the support member 50 is configured as a downward substantially U-shaped member, and the inner surface of the main body 51 has a friction coefficient in order to be mounted and held on the drive shaft 18 from above. A bearing member 53 made of a small material is disposed so as not to hinder the rotation of the drive shaft 18. The main body 51 may be made of a material having a small friction coefficient. A plurality of protrusions 52 are provided on the upper surface of the main body 51 of the support member 50 so as to protrude in the width direction of the sheet conveying device at a predetermined interval to guide the sheet. Further, a claw receiving member 55 for locking and holding the locking claw member 45 of the guide member is provided at the downstream portion of the support member 50 in the sheet conveyance direction at a substantially central portion in the width direction of the apparatus. ing.
[0015]
The guide member 40 supported by the support member 50 is integrally formed using a plastic material, and includes a main body 41 having a substantially arc-shaped guide surface 41a, and a vertical member 42 protruding toward the lower surface. And the flange 43 arrange | positioned at both ends and arbitrary positions, and the rib 44 arrange | positioned at predetermined intervals between the said flanges are provided. Further, the locking claw member 45 provided at the center of the vertical member 42 is locked to the claw receiving member 55 provided on the support member 50, and the guide member 40 is combined with the bearing member 50 to be integrated and driven. The shaft 18 is held to act as a guide plate for the paper. Furthermore, even if the guide member 40 is curved downward from the beginning, the support member 50 has an effect of suppressing the curvature. A guide sheet 49 extending from the guide surface is disposed at the tip of the main body 41 of the guide member to guide the paper toward the large-diameter driving roller 21. As the guide sheet 49, a plastic thin sheet is used. For example, a PET (polyethylene terephthalate) resin film (Mylar: trade name) may be used.
[0016]
The guide member 40 is configured as shown in the front view of FIG. 3 and the bottom view of FIG. 4. End guides 46 and 46 are integrally provided at both ends of the main body 41, and the flange 43, the rib 44, Are arranged at predetermined intervals to reinforce the main body. In addition, a screw hole 48 is provided in the end fixing portion 46, and the end fixing portion 46 is screw-fixed so as to press the pressing surface 47 against the supporting surface 39 provided in the supporting member 38 of the intermediate frame 30. The support surface 39 of the support member 38 that supports the pressing surface 47 of the end fixing portion 46 is formed horizontally, but the pressing surface 47 of the end fixing portion 46 has an angle θ (for example, 1 to 2 °) with respect to the horizontal plane. It is formed as an inclined surface. Then, when the end fixing portion 46 is screwed to the support member, the pressing surface 47 is pressed against the support surface 39, so that the main body 41 of the guide member 40 is shown by the phantom line in FIG. In this state, it is bent downward. Note that the guide member 40 is bent upward so as to be bent substantially horizontally or downward by performing the fixing action, and can be positioned by the support member 50 so that the central portion is lowered. Therefore, since the action of bending the main body 41 is performed by the end fixing portions 46 at both ends of the guide member 40, the screw members are attached by fitting the screw holes of both the support member 50 and the guide member 40. A bending action is applied so that the center portion of the guide member 40 is lowest, and the guide surface for the sheet is set to a shape that is curved substantially horizontally or downward in the width direction of the sheet conveyance path.
[0017]
The main body 41 of the guide member 40 is provided with a locking claw member 45 at or near the center in the width direction so as to be locked and held with respect to the claw receiving member 55 provided on the support member 50. I have to. The curved state of the guide member 40 is kept constant while the locking claw member 45 is locked to the claw receiving member 55, so that the guide member 40 is attached to the mounting surface of the main body. The shape of the guide surface can be automatically set only by fixing with screws. The guide member 40 is not provided only in a portion for guiding the sheet toward the curved path 20, but can be disposed at an arbitrary position as a guide plate for the sheet conveyance path. On the other hand, it can be used as means for giving an action of bending in the width direction and guiding the guide member toward the guide member disposed in the downstream portion of the sheet conveyance path. In addition, the inclination angle θ of the pressing surface 47 of the end fixing portion 46 formed at both ends of the guide member 40 can be set to an arbitrary angle according to conditions such as the width of the paper conveyance path, Even when the central portion of the guide member 40 is bent more than the set state, the locking claw member 45 is locked to the claw receiving member 55 provided on the support member 50 to correct the curved state of the central portion. Can do.
[0018]
Example shown in FIG. 5 shows a configuration of a reader 60 provided in the image forming apparatus and integrally, to the scanning unit frame 61 is provided with a scanning device 63 configured as shown in FIG. The scanning device 63 includes a full-rate carriage 64 provided with a lamp 64a and one mirror m1, and two opposing mirrors m2, as in the device used in a conventionally known copying machine scanning device. A half-rate carriage 65 in which m3 is arranged is provided in combination. The document reading information is transmitted to the CCD 69 via the lens device 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.
[0019]
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 23 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 upper opening / closing frame 70 is closed, so that the platen cover 73 presses the image surface of the document against the upper surface of the platen, thereby Scan. For the document set on the platen 62, the full rate carriage 64 of the scanning device 63 reciprocates by the length of the document in accordance with detection information of a sensor (not shown), and the half rate carriage 65 moves to the full rate. Image information is read while moving at half the speed of the carriage, and an image signal is output from the CCD 69. Further, when scanning a document on a sheet using the document tray 71, the scanning device 63 is fixed to a portion of the platen 23 while the document is conveyed through a conveyance path provided in a document conveyance unit as an ADF. The image reading operation is performed.
[0020]
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. Then, 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 23, the half-rate carriage 65 is moved to the left end of the scanning unit frame 63, and the document tray The originals are conveyed one by one from the 71 into the U-shaped conveyance path, and the image of the original is read by the platen 23. 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 23, and an operation for reading an arbitrary document can be performed, and the transmission function of the facsimile device can be achieved. It can be used to transmit image information, or can be printed on recording paper using the function of a copying machine.
[0021]
Note that when the automatic document feeder 1 shown in the embodiment is used alone, and the reading apparatus configured by integrating the automatic document feeder and the FBS may be configured as a reading apparatus alone. it can. In general, it can be used as a document reading unit provided integrally in the image forming apparatus or as a reading device of a facsimile apparatus. Also in the example of the reading device 60 shown in FIG. 5, as shown in FIGS. 1 to 4, the guide member 40 is used to guide the paper from the conveying roller device 15 toward the large-diameter driving roller 21 on the curved path. It is possible to use means for disposing and transporting the paper in a curved state in the width direction. The paper guide that guides the paper by being fixed at both sides of the paper conveyance path and curving so that the central part is lowered is used as a member for guiding the paper toward the curved part of the paper conveyance path. In addition to this, it can be used as a means that is arranged at an arbitrary position in the sheet conveyance path and feeds it while correcting the curve in the width direction of the sheet toward the guide member at the downstream portion.
[0022]
【The invention's effect】
Since the apparatus of the present invention is configured as described above, the sheet guide is provided on the downstream side of the conveying roller apparatus that conveys the sheet sent from the supply tray and guides the sheet to the curved sheet conveying path. Is curved in a direction away from the paper path surface, it is possible to prevent the upstream end of the guide from protruding and to prevent jamming of the paper in the paper transport path. In addition, by providing an inclined surface that curves downward in the entire paper guide, even if the paper is curved upward so that both ends in the width direction are warped upward, the state of the paper guide The paper can be guided toward the curved road. Further, since a guide support attached to the shaft of the transport roller device is provided at the center of the paper guide, even if the paper guide is curved downward, the curved state is corrected by the guide support. Can be attached to the device in a state.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of the structure of an automatic document feeder to which the configuration of the present invention can be applied.
FIG. 2 is an explanatory view showing a configuration of a guide member and a support member.
FIG. 3 is a front view of a guide member.
FIG. 4 is a bottom view of the guide member.
FIG. 5 is an explanatory diagram of an example in which the apparatus of FIG. 1 is combined with an image reading apparatus.
[Explanation of symbols]
1 automatic document feeder, 2 base frame, 3 upper frame,
5 Pickup roller, 9 Guide plate, 10 Paper separation device,
11 Separating roller, 12 retard roller, 14 transport path,
15 transport roller device, 16 pinch roller, 17 drive roller,
18 axis, 20 curved path, 21 large diameter drive roller,
22 pinch rollers, 23 platens, 24 discharge paths,
25 discharge roller device, 27 driving roller, 30 intermediate frame,
31 frame body, 35 upper cover, 39 support surface,
40 guide member, 41 body, 42 vertical member,
43 flange, 44 rib, 45 locking claw member,
46 end fixing part, 47 pressing surface, 48 screw hole,
49 guide sheet, 50 support member, 51 main body,
52 ridges, 53 bearing members, 55 claw receiving members,
60 readers, 62 platens, 64 full-rate carriages,
65 half-rate carriage, 68 lenses, 69 CCD,
71 Document tray, 72 discharge tray.

Claims (3)

The sheet guided by the guide member provided on the upstream portion of the paper conveying direction definitive the paper transport path, the paper guide further guided by the guide member provided at a downstream portion,
When both ends of the guide member in the downstream portion are screwed to the frame of the apparatus, an intermediate portion in the width direction of the guide surface of the guide member in the downstream portion with respect to the sheet conveying direction is caused by stress at the time of screw tightening. A paper guide that is forcibly deformed in a direction away from the paper path surface . Mounted surfaces are provided at both ends of the paper guide, and the mounted surfaces have inclined surfaces that curve the entire guide downward with respect to a horizontal mounting surface formed in the apparatus main body. The paper guide according to claim 1. 3. A sheet conveying apparatus according to claim 1, wherein a sheet guide is provided for guiding the sheet to a curved sheet conveying path disposed between the supply tray and the discharge tray.

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