JP2004037959A - Document conveying device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an apparatus from being large-sized while stably conveying a document by reducing an impact of a document front end. <P>SOLUTION: The document conveying device is equipped with a read part 422 which reads an image of a moving document (d), a before-read conveyor roller 421 which is arranged upstream from the read part 422 and conveys the document (d), and an after-read conveyor roller 424 which is arranged downstream from the read part 422 and conveys the document (d) having been read; and a conveyance guide 860 which guides the document (d) to the after-read conveyor roller 424 is arranged downstream from the read part 422 and has a plurality of guide surfaces 860a and 860b with different tilt angles which guide the document front end d1, the tilt angle θ1 of the guide surface 860a on the read part side that the document front end d1 abuts against between the guide surfaces 860a and 860b is made smaller than the tilt angle θ2 of the guide surface 860b on the after-read conveyor roller side. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a manuscript that conveys a manuscript so that the image can be read in order to form an image by an image forming apparatus such as an electrophotographic copier, a printer, a facsimile, and a multifunction machine or a printing machine having a plurality of these functions. The present invention relates to a transport device and an image forming apparatus.
[0002]
[Prior art]
In a document conveying device provided in such a digital image forming apparatus, there is a document conveying device that separates and conveys documents stacked on a sheet feed tray one by one, and can read an image of the document by a reading unit.
[0003]
In such a document feeder, as shown in FIG. 12, a slit glass 101 is arranged in the reading section 100, and a conveyance guide 102 is arranged at a position facing the slit glass 101, and further, is opposed to the conveyance guide 102. The conveyance guides 103 and 104 are arranged before and after reading.
[0004]
By driving a pair of pre-read conveyance rollers 110 arranged on the upstream side of the reading unit 100, the document d is guided and conveyed by the conveyance guide 103, and the reading unit 100 reads an image of the moving document d. The leading end of the document d after reading abuts on the transport guide 104, and is guided by the transport guide 104 to a pair of post-read transport rollers 111 arranged downstream of the reading unit 100.
[0005]
[Problems to be solved by the invention]
In such a configuration, the conveyance guide 104 arranged after reading has a single R-surface shape, although the guide surface has a slope shape. In order to save space, the radius of curvature of the R-plane shape of the guide surface must be reduced.
[0006]
By the way, if the radius of curvature of the R-surface shape is reduced, the impact when the leading end of the read document d collides with the guide surface of the transport guide 104 increases, resulting in an image defect.
[0007]
In order to prevent such image defects, it is desirable to increase the radius of curvature of the R surface shape of the guide surface. However, this causes a problem that the document transport device itself becomes large.
[0008]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a document feeder and an image forming apparatus that reduce the impact of the leading edge of the document, perform stable document feed, and prevent the apparatus from being enlarged. And
[0009]
[Means for Solving the Problems]
In order to solve the above problems and achieve the object, the present invention is configured as follows.
[0010]
The invention according to claim 1 is a reading unit that reads an image of a moving document, a pair of pre-read transport rollers that are arranged upstream of the reading unit and transport the document, and downstream of the reading unit. A document transport device including a pair of post-read transport rollers that transports the document that has been placed and has been read,
A conveyance guide that guides the document on the downstream side of the reading unit and guides the document to the conveyance roller after reading is arranged,
The conveyance guide has a plurality of guide surfaces having different inclination angles for guiding the leading edge of the document, and among the plurality of guide surfaces, the inclination angle of the guide surface on the reading unit side where the leading edge of the document abuts is read. A document feeder characterized in that the angle of inclination is smaller than the inclination angle of the guide surface.
[0011]
According to the first aspect of the present invention, the inclination angle of the guide surface on the reading section, on which the leading end of the document abuts, of the guide surface of the transport guide is made smaller than the inclination angle of the guide surface on the transport roller after reading. In addition, it is possible to reduce the impact of the leading edge of the original and to stably convey the original while preventing the apparatus from being enlarged.
[0012]
According to a second aspect of the present invention, a reading unit that reads an image of a moving document, a pair of pre-read conveyance rollers that are arranged upstream of the reading unit and convey the document, and downstream of the reading unit A document transport device including a pair of post-read transport rollers that transports the document that has been placed and has been read,
A conveyance guide that guides the document on the downstream side of the reading unit and guides the document to the conveyance roller after reading is arranged,
The conveyance guide has a plurality of different R-shaped guide surfaces for guiding the document, and, among the plurality of guide surfaces, the radius of curvature of the guide surface on the reading section side where the leading end of the document abuts is on the conveyance roller side after reading. A document conveying device characterized in that the document conveying device has a larger radius of curvature than a guide surface.
[0013]
According to the second aspect of the present invention, the radius of curvature of the guide surface on the reading section, on which the leading end of the document abuts, is larger than the radius of curvature of the guide surface on the transport roller after reading. In addition, it is possible to reduce the impact of the leading edge of the original and to stably convey the original while preventing the apparatus from being enlarged.
[0014]
According to a third aspect of the present invention, there is provided a reading unit that reads an image of a moving document, a pre-reading conveying roller that is disposed upstream of the reading unit and conveys the document, and that is disposed downstream of the reading unit. And a post-reading conveyance roller for conveying the document whose reading has been completed.
A reading guide that is located at the reading section and extends toward the post-reading conveyance roller; and a conveyance guide that is disposed downstream of the reading section and faces the reading guide and guides the document and guides the document to the post-reading conveyance roller. And having
A passage for conveying the document is formed by the reading guide and the conveyance guide, and the passage has a smaller passage interval on the conveying roller after reading than the passage interval on the reading section where the leading edge of the document contacts. A document transport device.
[0015]
According to the third aspect of the present invention, a passage for conveying the document is formed by the reading guide and the conveyance guide, and the passage is closer to the conveying roller after reading than the passage interval on the reading section where the leading end of the document contacts. By reducing the interval, it is possible to reduce the impact of the leading edge of the document, to stably transport the document, and to prevent an increase in the size of the apparatus.
[0016]
According to a fourth aspect of the present invention, there is provided an image forming apparatus including the document feeder according to any one of the first to third aspects.
[0017]
According to a fourth aspect of the present invention, the document feeder according to any one of the first to third aspects is provided, the impact of the leading edge of the document is reduced, and the document is transported stably. It is possible to prevent the device from being enlarged.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of an image forming apparatus provided with the document feeder of the present invention will be described with reference to the drawings, but the present invention is not limited to this embodiment.
[0019]
FIG. 1 is an overall configuration diagram of an image forming apparatus 1 equipped with a sheet post-processing device FS, a document transport device DF, and an image reading device (scanner) SC.
[0020]
The illustrated image forming apparatus main body 1A includes an image processing unit 2, an image writing unit 3, an image forming unit 4, a high-voltage power supply unit 5, a cassette paper feeding unit 6, a fixing device 7, a paper discharging unit 8, and an automatic duplex copy. A re-transporting means (ADU) 9 is provided.
[0021]
An image reading device SC and a document conveying device DF are mounted on the upper part of the image forming apparatus main body 1A. A sheet post-processing device FS is connected to the upper left side of the image forming apparatus main body 1A on the side of the paper discharge unit 8 in the drawing.
[0022]
The original d placed on the original table of the original transport device DF with the first surface facing upward is transported in the direction of the arrow, and the image of one or both sides of the original is read by the optical system of the image reading device SC. The image is read by the image sensor C1.
[0023]
The analog signal photoelectrically converted by the CCD image sensor C1 is subjected to analog processing, A / D conversion, shading correction, image compression processing, and the like in the image processing unit 2, and then sent to the image writing unit 3.
[0024]
In the image writing section 3, the output light from the semiconductor laser is applied to the photosensitive drum 4A of the image forming section 4 to form a latent image. In the image forming unit 4, processes such as charging, exposure, development, transfer, separation, and cleaning are performed, and an image is transferred to the sheet S transported from the cassette sheet feeding unit 6. The sheet S carrying the image is fixed by the fixing device 7 and sent from the sheet discharge unit 8 to the sheet post-processing device FS. Alternatively, the single-sided image-processed sheet S sent to the re-conveying means 9 by the sheet discharging path switching plate 8A is subjected to the double-sided image processing again in the image forming unit 4, and then the sheet S is discharged by the sheet discharging rollers 8B of the sheet discharging unit 8. It is sent to the processing device FS.
[0025]
The sheet post-processing device FS is detachably mounted on the upper left portion of the image forming apparatus main body 1A. The sheet post-processing apparatus FS includes a sheet transporting unit 10, a sheet discharging unit 20, a post-processing unit 30, and an elevating sheet discharging unit 40, and these are arranged in a sheet post-processing unit main body 45.
[0026]
In FIG. 1, on the right side in the main body 1A of the image forming apparatus, a cassette paper feeding section 6 is provided below the main body 1A of the image forming apparatus 1A in the height direction, and a fixing device 7 is provided above the main body 1A. A paper section 8 is provided. With this vertical arrangement, a paper transport path (1) in a substantially vertical direction is formed. The sheet S sent out from the cassette sheet feeding unit 6 is conveyed along the vertically upper sheet conveying path (1) and discharged out of the image forming apparatus main body 1A.
[0027]
A paper transport path (2) by the re-transporting means 9 is formed substantially parallel to the vertical paper transport path (1).
[0028]
By forming the above-described paper transport paths (1) and (2) in the vertical direction, the shortest paper transport path from the cassette paper feed unit 6 to the paper discharge unit 8 is configured.
[0029]
The sheet conveying means 10 of the sheet post-processing device FS is accommodated in the space above the image forming apparatus main body 1A as shown. The paper inlet 11 of the paper transporting means 10 is connected to a paper discharge roller 8B of the paper discharge part 8 of the image forming apparatus main body 1A. Further, in this mounting state, the sheet discharging means 20 and the post-processing means 30 of the sheet post-processing apparatus FS are accommodated in the upper left space of the image forming apparatus main body 1A in the drawing. The elevating and lowering discharging means 40 including a plurality of discharging trays (also referred to as bins) 41 and elevating and lowering driving means 42 is located on the left side of the post-processing means 30 in the drawing.
[0030]
Next, the document feeder will be described with reference to FIGS. 2 is a cross-sectional view of the document feeder, FIG. 3 is a plan view of the document feeder, FIG. 4 is an enlarged view of a main part of the document feeder, FIG. 5 is an enlarged view of a switching unit, and FIG. FIG. 7 is a diagram showing a two-sided paper passing path.
[0031]
The document feeder DF includes a document feeder 200, a document discharger 300, and a document feeder 400.
[0032]
The document feeding section 200 has a sheet feeding tray 201 on which a plurality of documents can be set, and a pair of regulating plates 202 for positioning the document in the width direction are provided on the sheet feeding tray 201 so as to be movable in the width direction. ing. Further, sensors constituting the length direction detecting means S11 and S12 for detecting the length direction of the document are arranged at two places on the sheet feeding tray 201.
[0033]
The document discharge unit 300 has a discharge plate 301, and the discharge plate 301 is disposed below the document supply unit 200. A document conveyed so that one side is read by the document conveying unit 400 or a document conveyed such that both sides are read is discharged onto the sheet discharge tray 301.
[0034]
The document transport section 400 has a first transport path 410 on the upstream side, a second transport path 420 and a third transport path 430 branched to the downstream side, and a discharge section 440. In the first transport path 410, a movable pressing plate 411, a pickup roller 412, a separation transport roller 413, and a double feed prevention roller 414 are arranged. The movable pressing plate 411 rises at each paper feeding, presses the original against the pickup roller 412 and presses the original against the separation and conveyance roller 413, and separates and conveys the original one by one by the separation and conveyance roller 413 and the double feeding prevention roller 414. Is done. Further, a sensor constituting the document length detecting means S21 is disposed downstream of the separation conveyance roller 413 and the double feed prevention roller 414.
[0035]
In the second transport path 420, a transport roller 421 before reading, a reading unit 422, a reading guide 831 and a transport roller 424 after reading are arranged. On the downstream side of the pre-read conveyance roller 421, a sensor constituting the document leading edge detecting means S31 is arranged. The pre-read conveyance roller 421 and the post-read conveyance roller 424 can rotate forward in the document conveyance direction.
[0036]
In the third transport path 430, a transport roller 431 and a reversing unit 432 are arranged. The reversing unit 432 has a reversing roller 433. The transport roller 431 and the reversing roller 433 can rotate forward and backward. In the discharge unit 440, a paper discharge roller 441 is arranged.
[0037]
Further, the first transport path 410 is provided with a first switching member 450 that can switch from the first transport path 410 to a second transport path 420 and a third transport path 430 on the downstream side. The first switching member 450 is provided so as to be rotatable integrally with the support shaft 453. An arm 453a is provided at one end of the support shaft 453, and an arm 453b is provided at the other end. The arm 453a is urged by a spring 451, the first switching member 450 opens the second transport path 420, and The three transport path 430 is closed. The arm 453b is operated by a solenoid 452 against a spring 451. When the solenoid 452 is operated, the second transport path 420 is closed and the third transport path 430 is opened.
[0038]
Further, a second switching member 460 and a third switching member 470 integrally formed are rotatably supported by the support shaft 453. The second switching member 460 and the third switching member 470 are urged by a spring 471, the second switching member 460 opens the second transport path 420, and the third switching member 470 closes the third transport path 430. I have.
[0039]
In the second transport path 420, a second switching member 460 urged in one direction enabling transport from both sides of the first transport path 410 and the third transport path 430 is disposed. The spring 471 allows the transfer from the first transfer path 410 and regulates the transfer from the third transfer path 430. However, when the document is transferred from the third transfer path 430, the document is , And can be automatically opened and transported.
[0040]
Further, a third switching member 470 urged in one direction that enables transport from both sides of the first transport path 410 and the second transport path 420 is disposed in the third transport path 430. The spring 471 regulates the conveyance from the first conveyance path 410 and is urged to allow the conveyance from the third conveyance path 430. However, when the document is conveyed from the first conveyance path 410, The document can be automatically opened and transported by transporting the document.
[0041]
The first switching member 450, the second switching member 460, and the third switching member 470 move the coaxial support shaft 453 disposed at the junction of the first transport path 410, the second transport path 420, and the third transport path 430. It can be opened and closed as a fulcrum, and it is easy to secure an arrangement space at one place, and it is possible to reduce the size.
[0042]
On the downstream side of the reading unit 422, a fourth switching member 490 that can switch between the reversing unit 432 and the discharging unit 440 is provided so as to be integrally rotatable with the support shaft 493. An arm 493a is provided at one end of the support shaft 493, and an arm 493b is provided at the other end. The arm 493a is urged by a spring 491, opens the inlet 440a of the discharge unit 440, and opens the inlet 432a of the reversing unit 432. Is closed. The arm 493b is operated by a solenoid 492 against a spring 491, and when the solenoid 492 is operated, the entrance 440a of the discharge part 440 is closed and the entrance 432a of the reversing part 432 is opened.
[0043]
When reading one side of the document d in this embodiment, as shown in FIG. 6, the reading unit 422 reads one side of the document d and conveys it through a single-sided paper passing path P1.
[0044]
That is, the originals d stacked on the paper feed tray 201 are separated and transported one by one, and the first switching member 450 closes the third transport path 430. The document D is conveyed to the second conveyance path 420 and the reading unit 422 reads one side of the document d. The read document d is discharged onto the discharge tray 301 through the discharge unit 440 because the fourth switching member 490 closes the entrance 432a of the reversing unit 432 and opens the entrance 440a of the discharge unit 440. Paper.
[0045]
When reading both sides of the document d, as shown in FIG. 7, one side of the document d is guided to the reversing unit 432 to be inverted and conveyed, and the reading unit 422 guides it to the reading reversing unit 432. Then, the document D is conveyed in reverse, and the other side of the document d is conveyed through the double-sided paper passing path P2 in which the reading unit 422 reads and discharges the sheet.
[0046]
That is, the originals d stacked on the sheet feeding tray 201 are separated and conveyed one by one, the solenoid 452 is operated, the first switching member 450 opens the third conveying path 430, and the original d is the first original. The sheet is transported from the transport path 410 to the third transport path 430. Although the third switching member 470 disposed in the third transport path 430 closes the third transport path 430, the third switching member 470 is pushed by the document d being transported, opens against the spring 471, and closes when the document d passes. .
[0047]
In the third transport path 430, the transport roller 431 and the reversing roller 433 of the reversing unit 432 rotate forward to carry in the document d, and the transport roller 431 and the reversing roller 433 rotate in reverse to switch back and transport the document d. The document is conveyed from the third conveyance path 430 to the second conveyance path 420 via the second switching member 460 and the third switching member 470, and the reading section 422 reads one side of the document d.
[0048]
In the state in which the document d is switched back and transported, the second switching member 460 and the third switching member 470 are at the initial position by the spring 471, and the document d transported by switching back the third switching member 470. And pushes the second switching member 460. The second switching member 460 is pushed by the document d being conveyed, opens against the spring 471, and closes when the document d passes.
[0049]
For the document d thus read, the solenoid 492 operates and the fourth switching member 490 opens the entrance 432a of the reversing unit 432 and closes the entrance 440a of the discharging unit 440. Then, it is sent to the reversing unit 432. Then, the transport roller 431 and the reversing roller 433 rotate in the reverse direction to switch back and transport the document d, and are transported from the third transport path 430 to the second transport path 420 via the second switching member 460 and the third switching member 470. Then, the reading unit 422 reads the other side of the document d.
[0050]
The read document d is discharged onto the discharge tray 301 through the discharge unit 440 because the fourth switching member 490 closes the entrance 432a of the reversing unit 432 and opens the entrance 440a of the discharge unit 440. Paper.
[0051]
The document transport device capable of reading one side of the document d and both sides of the document d is a document registration mechanism A that abuts and aligns the leading edge of the document with a pair of rollers disposed upstream of the reading unit 422 and downstream of the reversing unit 432. The document registration mechanism A includes a pre-reading conveyance roller 421. The original registration mechanism A is arranged upstream of the reading unit 422 and downstream of the reversing unit 432, and the leading edge of the original is abutted by a pair of rollers of the original registration mechanism A to align the original d. The correction can be processed in one place.
[0052]
A registration loop formation space SP1 that allows a loop of the document d generated when the document d is aligned by the document registration mechanism A is formed in the single-sided paper passage path P1, and a registration loop formation space SP2 is formed in the double-sided paper passage path P2. By allowing the loop of the document d generated when the documents are aligned by the registration mechanism A in the registration loop forming spaces SP1 and SP2, it is possible to surely correct the bending of the document d on one side and both sides.
[0053]
A document position detecting means S41 is disposed upstream of the document registration mechanism A, and a document position detecting means S41 for detecting the position of the document is disposed immediately after the confluence of the single-sided paper path P1 and the double-sided paper path P2. By doing so, the position of the document d can be detected on both one side and both sides of the document d.
[0054]
In this embodiment, the downstream side of the reading unit 422 is configured as shown in FIGS. 8 to 11, FIG. 8 is an enlarged side view of the reading unit, and FIG. 9 is the downstream side of the reading unit of the first embodiment. FIG. 10 is an enlarged view showing the downstream side of the reading unit of the second embodiment, and FIG. 11 is an enlarged view showing the downstream side of the reading unit of the third embodiment.
[0055]
In the reading section 422 of this embodiment, a slit glass 830 is arranged, and a reading guide 831 is arranged to face the slit glass 830.
[0056]
The reading guide 831 is integrally formed in a plate shape with resin, and a central portion 831 a faces the slit glass 830 in a plane. The front end 831b of the reading guide 831 extends to the position of the pre-reading conveying roller 421, and the rear end 831c of the reading guide 831 extends to the position of the post-reading conveying roller 424.
[0057]
In this embodiment, a transport guide 850 is arranged on the upstream side in the transport direction of the reading unit 422 so as to face the read guide 831. The transport guide 850 is integrally formed of resin in a plate shape, and guides the original d from the rollers 421 a and 421 b which are the transport rollers 421 before reading to the reading unit 422 by the reading guide 831 and the transport guide 850.
[0058]
The roller 421a is a driven roller and the roller 421b is a driving roller. A pair of conveyance guides 831 and 850 form a conveyance path P5 having a curvature from the pair of rollers 421a and 421b to the reading unit 422. The document d is transported by P5, and the reading unit 422 reads the document.
[0059]
A transport guide 860 that guides the document d and guides it to the transport roller 424 after reading is arranged downstream of the reading unit 422.
[0060]
The transport guide 860 of the embodiment of FIG. 9 has a plurality of guide surfaces 860a and 860b with different inclination angles for guiding the leading edge d1 of the document. Of the plurality of guide surfaces 860a and 860b, the inclination angle θ1 of the guide surface 860a on the reading section, where the leading edge d1 of the document abuts, is set smaller than the inclination angle θ2 of the guide surface 860b on the conveyance roller after reading. The inclination angle θ1 of the guide surface 860a on the reading unit side and the inclination angle θ2 of the guide surface 860b on the conveyance roller side after reading are determined by moving the document d on the reading unit 422 and setting the leading end d1 of the document to the guide surface 860a on the reading unit side. Is the angle with respect to the direction in which
[0061]
As described above, since the inclination angle θ1 of the guide surface 860a on the reading section at which the leading edge d1 of the document abuts is small, the impact when the leading edge d1 of the document abuts on the guide surface 860a of the reading portion is reduced, and stable document transport is achieved. Can do it. Further, since the inclination angle θ2 of the guide surface 860b on the side of the conveying roller after reading is large, the position of the conveying roller 424 after reading becomes high, but the conveying roller 424 after reading can be arranged closer to the reading unit 422, and accordingly, it can be arranged in the document conveying direction. Since the space is reduced, it is possible to prevent the device from being enlarged.
[0062]
The transport guide 861 of the embodiment shown in FIG. 10 has a plurality of different R-shaped guide surfaces 861a, 861b, 861c for guiding the document d. The curvature radii R2, R1, R3 of the plurality of guide surfaces 861a, 861b, 861c are R1 <R2, R1> R3.
[0063]
As described above, of the plurality of guide surfaces 861a, 861b, and 861c, the radius of curvature R2 of the guide surface 861a on the reading section where the leading edge d1 of the document abuts is larger than the radius of curvature R3 of the guide surface 861c on the conveying roller after reading. ing.
[0064]
As described above, among the guide surfaces 861a, 861b, and 861c of the transport guide 861, the curvature radius R2 of the guide surface 861a on the reading section where the leading edge d1 abuts is large, so that the leading edge d1 of the document is guided on the reading portion 861a. Impact on the document can be reduced, and the document can be stably conveyed. In addition, since the radius of curvature of the guide surface 861c on the side of the conveying roller after reading is small, the disposition position of the conveying roller 424 after reading is high, but the conveying roller 424 can be disposed closer to the reading unit 422, and the space in the document conveying direction is correspondingly increased. Therefore, it is possible to prevent an increase in the size of the device.
[0065]
In the embodiment of FIG. 11, a reading guide 831 that is located at the reading unit 422 and extends to the side of the conveyance roller after reading is provided. And a conveyance guide 862 that guides to the rear conveyance roller side. The reading guide 831 and the conveying guide 862 form a path D10 for conveying the document d. The path D10 is smaller than the path interval D12 on the conveying roller side after reading than the path interval D11 on the reading section where the leading edge d1 of the document contacts. are doing.
[0066]
In this embodiment, the transport guide 862 is configured in the same manner as the transport guide 860 in the embodiment in FIG. 9, but is configured in the same manner as the transport guide 861 in the embodiment in FIG. The passage interval D12 on the conveying roller side after reading may be smaller than the passage interval D11 on the reading unit side that comes into contact.
[0067]
In this way, by reducing the path spacing D12 near the apex portion of the transport guide 862 on the downstream side in the transport direction to be small, the impact given to the leading edge d1 of the document is reduced, and the behavior of the document d within the path spacing D12 is reduced. Can be minimized, image defects can be prevented, and the device can be prevented from being enlarged.
[0068]
Further, in the embodiment of the present invention, the document feeder connected to the copier is shown, but it is connected to an image forming apparatus such as a printer and a facsimile, and a multi-function printer and a light printer having a plurality of these functions. The present invention can also be applied to a document transport device that is used by a user.
[0069]
【The invention's effect】
As described above, according to the first aspect of the present invention, the inclination angle of the guide surface on the reading section, on which the leading end of the document abuts, is smaller than the inclination angle of the guide surface on the conveyance roller after reading. Thus, it is possible to reduce the impact of the leading edge of the document, to stably transport the document, and to prevent the apparatus from being enlarged.
[0070]
According to the second aspect of the present invention, the radius of curvature of the guide surface on the reading section where the leading edge of the document abuts among the guide surfaces of the transport guide is larger than the radius of curvature of the guide surface on the transport roller side after reading. It is possible to reduce the size of the apparatus while reducing the impact and performing stable document conveyance.
[0071]
According to the third aspect of the present invention, a passage for transporting the original is formed by the reading guide and the transport guide, and the passage has a smaller path interval on the conveying roller after reading than the path interval on the reading section where the leading edge of the original contacts. By doing so, it is possible to reduce the impact of the leading edge of the document, to stably transport the document, and to prevent an increase in the size of the apparatus.
[0072]
According to a fourth aspect of the present invention, there is provided the document feeder according to any one of the first to third aspects, the impact of the leading edge of the document is reduced, the document is transported stably, and the size of the device is increased. Can be prevented.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an image forming apparatus equipped with a sheet post-processing device, a document conveying device, and an image reading device.
FIG. 2 is a cross-sectional view of the document feeder.
FIG. 3 is a plan view of the document feeder.
FIG. 4 is an enlarged view of a main part of the document feeder.
FIG. 5 is an enlarged view of a switching unit.
FIG. 6 is a diagram illustrating a one-sided paper passing path.
FIG. 7 is a diagram illustrating a two-sided paper passing path.
FIG. 8 is an enlarged side view of a reading unit.
FIG. 9 is a diagram illustrating a downstream side of the reading unit according to the first embodiment.
FIG. 10 is a diagram illustrating a downstream side of a reading unit according to the second embodiment.
FIG. 11 is an enlarged view showing a downstream side of a reading unit according to the third embodiment.
FIG. 12 is an enlarged side view of a conventional reading unit.
[Explanation of symbols]
DF Document Conveyor
1 Image forming apparatus
1A Image Forming Apparatus Main Body
400 Document feeder
421 Transport roller before reading
422 reading unit
424 Transport roller after reading
831,860 transport guide
860a, 860b Guide surface
d manuscript
d1 Original document

Claims (4)

A reading unit that reads an image of a moving document, a pre-reading conveyance roller that is disposed upstream of the reading unit and conveys the document, and conveys the document that has been read and disposed downstream of the reading unit. And a post-reading conveying roller that performs
A conveyance guide that guides the document on the downstream side of the reading unit and guides the document to the conveyance roller after reading is arranged,
The conveyance guide has a plurality of guide surfaces having different inclination angles for guiding the leading edge of the document, and among the plurality of guide surfaces, the inclination angle of the guide surface on the reading unit side where the leading edge of the document abuts is read. A document feeder, wherein the inclination angle of the guide surface is smaller than the angle of inclination. A reading unit that reads an image of a moving document, a pair of pre-read conveyance rollers that are arranged upstream of the reading unit and convey the document, and the document that is disposed downstream of the reading unit and has been read And a pair of post-reading transport rollers for transporting
A conveyance guide that guides the document on the downstream side of the reading unit and guides the document to the conveyance roller after reading is arranged,
The transport guide has a plurality of different R-shaped guide surfaces for guiding the document, and, among the plurality of guide surfaces, the radius of curvature of the guide surface on the reading unit side where the leading edge of the document abuts is the guide on the transport roller side after reading. A document feeder characterized by having a larger radius of curvature of the surface. A reading unit that reads an image of a moving document, a pre-reading conveyance roller that is disposed upstream of the reading unit and conveys the document, and conveys the document that has been read and disposed downstream of the reading unit. And a post-reading conveying roller that performs
A reading guide that is located at the reading section and extends toward the post-reading conveyance roller; and a conveyance guide that is disposed downstream of the reading section and faces the reading guide and guides the document and guides the document to the post-reading conveyance roller. And having
A passage for conveying the document is formed by the reading guide and the conveyance guide, and the passage has a smaller passage interval on the conveying roller after reading than the passage interval on the reading section where the leading edge of the document contacts. Document feeder. An image forming apparatus, comprising: the document conveying device according to claim 1.

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