JP3970113B2 - Image reading apparatus and image forming apparatus having the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image reading apparatus and an image forming apparatus including the image reading apparatus, and more particularly to a configuration of a roller that conveys a document when an image is read with an image reading unit stopped at a reading position.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an image forming apparatus such as a digital copying machine, a printer, or a facsimile includes an image forming unit and an image reading apparatus that reads an original, and forms an image based on image information read by the image reading apparatus. There is something.
[0003]
As such an image reading apparatus, in addition to book original reading, in which the original is read by moving the image reading means in the left-right direction and scanning the original while the book original is placed on the original glass, In some cases, the reading means is stopped, and in this state, a document image is read by moving the document in the sub-scanning direction by the document feeding device (ADF), so-called flow reading is performed.
[0004]
Here, many image reading apparatuses that perform such a flow reading process include a document guide for scooping a document that has passed through the reading position from the document glass during the scanning operation, and a predetermined document reading when reading a book document. In order to provide an original abutting plate that abuts the end of the original for placement at a position, there are some in which a book original reading original glass and a flow reading glass are provided separately.
[0005]
However, when the book original reading original glass and the flow reading glass are separately provided as described above, the image reading apparatus becomes large, so that, for example, the read original reading is performed on the book original reading original glass. By doing so, an image reading apparatus has been proposed in which the size and cost of the apparatus are reduced.
[0006]
FIG. 5 is a diagram showing a schematic configuration of a conventional image reading apparatus having such a configuration. This image reading apparatus includes a document feeding device 511 and a reading housing portion 512 as shown in FIG. .
[0007]
Here, the reading housing 512 is irradiated with light from the LED array as a light source for illuminating the document to the image information surface of the document, and the reflected light reflected by the image information surface is reflected by the SELFOC LENS (trademark). A contact-type image sensor 613 that forms an image on the sensor element and reads image information is provided.
[0008]
The contact image sensor 613 scans the book document placed on the document glass 501 by moving in the left-right direction when reading the book document, and reads the sheet document conveyed by the document feeder 511 by reading. At this time, it is stopped at the predetermined reading position shown in FIG.
[0009]
The document feeder 511 is provided with a document tray 502 on which documents are placed, a pickup roller 503 provided at a position facing the document above the document tray 502, and a separation pad provided downstream of the pickup roller 503. A separation unit including 504 and a separation roller 505 is provided. The pickup roller 503 is held so as to be in contact with and separated from the document by an arm 520 that is rotatably provided at the rotation center of the separation roller 505.
[0010]
Further, the document feeding device 511 is provided downstream of the separation roller 505, a registration roller pair 506, 507, a registration roller pair 506, 507, and a platen roller 508. A conveyance roller pair 509 and a paper discharge roller pair 510 for discharging a document are provided. The platen roller 508 can convey the original while pressing it on the glass table 501 of the reading casing 512.
[0011]
Here, each roller is rotated by transmitting a drive from a drive motor (not shown) by a gear train or a timing belt. For example, a one-way clutch (not shown) is provided for the pickup roller 503 and the separation roller 505. When the drive motor rotates in the forward direction, the drive is transmitted, and the drive of the drive motor is transmitted to the registration roller 507, the platen roller 508, the transport roller 509, and the paper discharge roller 510 through the one-way clutch when the drive motor rotates in the reverse direction. It has become so.
[0012]
In the image reading apparatus shown in the figure, an unillustrated original abutting plate is provided at the left end of the original glass 501, and an original guide 521 for scooping the original from the original glass 501 at the time of flow reading is provided at the right end of the original glass 501. Provided.
[0013]
Next, a flow reading operation of the image reading apparatus having such a configuration will be described.
[0014]
When a document is set on the document tray 502 with the document surface facing downward and a start button (not shown) is pressed, a drive motor (not shown) first rotates forward, thereby causing the pickup roller 503 to rotate in the document conveyance direction. The original is conveyed to the separation units 504 and 505. Then, after the original is separated into one sheet by the separation units 504 and 505, the original is abutted against a pair of registration rollers 506 and 507 that are not driving the original.
[0015]
Thereafter, the skew is corrected by rotating the drive motor forward for a predetermined time to form a loop on the document, and then the drive motor is stopped. As a result, the document is temporarily stopped in a state where it is in contact with the pair of registration rollers 506 and 507.
[0016]
Next, the drive motor rotates in the reverse direction to rotate the registration roller 507, whereby the document is conveyed to the platen roller 508 and read by the contact image sensor 613 while being in close contact with the glass table 501. Note that when the original comes off the platen roller 508, the reading is completed, and the original is discharged onto the paper discharge tray 522 by the transport roller pair 509 and the paper discharge roller pair 510.
[0017]
Then, when the document is discharged onto the discharge tray in this way, the drive motor rotates again. As a result, the next original is fed, and thereafter, reading is performed in the same manner as described above, and this is continued until there is no more original.
[0018]
By the way, when reading is performed by moving the document in the sub-scanning direction with the contact image sensor 613 fixed in this manner, stable conveyance of the document at the reading position is required. 507, the conveyance roller 509 and the discharge roller 510 on the downstream side of the reading position are configured to have the same roller outer diameter so that all have the same conveyance speed.
[0019]
[Problems to be solved by the invention]
However, in such a conventional image reading apparatus, even if the registration roller 507, the transport roller 509, and the paper discharge roller 510 have the same roller outer diameter, the same roller outer diameter does not occur due to variations in component accuracy. There is a case.
[0020]
Here, for example, when the roller diameter of the conveyance roller 509 on the downstream side of the reading position is larger than the registration roller 507 on the upstream side of the reading position, the conveyance speed of the conveyance roller 509 is high, and the conveyance roller 509 pulls the document due to the speed difference. In this case, there is a problem in that the original is quickly fed at the reading position at the moment when the rear end of the original passes through the registration roller 507, and the image blurring occurs.
[0021]
It should be noted that a one-way clutch is provided on the registration roller 507 on the upstream side of the reading position, and the outer diameter of the conveying roller 509 on the downstream side of the reading position is sufficiently larger than that of the registration roller 507 so as to absorb such variations in roller component accuracy. Therefore, there has also been proposed an apparatus in which the conveying roller 509 always pulls out the original from the registration roller 507. However, in such an apparatus, the number of one-way clutches is increased and the cost is increased. There is a problem that the arrangement of the clutch restricts the drive system and complicates the apparatus.
[0022]
Further, when the original document glass 501 is scanned as in the case of reading the book document as in the conventional example, the document feeder 511 places the document on the document glass 501 at a shallow approach angle with respect to the document glass 501. After the conveyance, the document is returned to the document feeder 511 by the document guide 521 provided at the right end of the document glass 501 to scoop the document from the document glass 501, and then the document is reversed by the reversing path Pr. Is discharged.
[0023]
Here, in the path configuration in which the original is conveyed to the reading position at such a shallow approach angle, since the stiffness of the original pressed against the original glass 501 at the reading position is weak, the roller diameters of the registration roller 507 and the conveying roller 509 are small. The posture of the document in the path is likely to change due to the difference in the conveyance speed due to the difference.
[0024]
Therefore, when the roller diameter of the conveying roller 509 is larger than that of the registration roller 507 as described above, the conveying speed of the conveying roller 509 is high, and the document is pulled between the registration roller 507 and the conveying roller 509. The document is positioned at the shortest distance in the paper path.
[0025]
When the original is positioned at the shortest distance in the paper path as described above, the original becomes free at the moment when the rear end of the original passes through the registration roller 507, and the original is quickly fed at the reading position. Image blurring tends to occur.
[0026]
Further, a reverse path Pr is provided between the transport roller 509 and the paper discharge roller 510, and the document becomes stiff when passing through the reverse path Pr. For this reason, when the roller diameter of the paper discharge roller 510 is larger than the transport roller 509, the transport speed of the paper discharge roller 510 is fast, and the document is pulled between the transport roller 509 and the paper discharge roller 510.
[0027]
When the document is pulled between the transport roller 509 and the paper discharge roller 510 in this way, the document is not only positioned at the shortest distance in the paper path (inside the reverse path), but also transported by the waist of the document. As a result, a pulling force of the document is generated, and as a result, the registration roller 507 and the conveyance roller 509 pull the document, resulting in image blurring as described above.
[0028]
Therefore, the present invention has been made in view of such a current situation, and provides an image reading apparatus capable of reading an image with less image blur with an inexpensive and simple configuration, and an image forming apparatus including the image reading apparatus. It is the purpose.
[0029]
[Means for Solving the Problems]
The present invention includes image reading means for reading an image of a document, and when reading the image of the document, the image reading means is stopped at a reading position, and the document is passed over the stopped image reading means. An image reading apparatus configured to read an image by providing an upstream roller provided upstream of the reading position and conveying an original to the reading position; and provided downstream of the reading position, wherein the reading position is A downstream roller that conveys the document that has passed through; a paper discharge roller that discharges the document conveyed by the downstream roller; A curved reversing path provided between the downstream roller and the paper discharge roller; With In order to prevent the document from being pulled between the upstream roller and the downstream roller due to the waist of the document when the document is conveyed by the paper discharge roller and passes the curved reversal path, The outer diameter of the upstream roller is the outer diameter of the downstream roller. Bigger And the outer diameter of the downstream roller is equal to the outer diameter of the paper discharge roller. Made bigger It is characterized by this.
[0031]
Further, the present invention is characterized in that a restriction roller for restricting the upward movement of the document passing above the image reading means is provided above the reading position.
[0032]
According to the present invention, in the image forming apparatus, the image reading apparatus according to any one of the above and an image forming unit that forms an image based on image information read by the image reading apparatus are provided. Is.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0034]
FIG. 1 is a diagram showing a schematic configuration of an image reading apparatus that performs flow reading using the same platen glass as when reading a book document according to an embodiment of the present invention.
[0035]
In the figure, 1A is an image reading device, and 1 is a document feeding device arranged on the upper portion of the image reading device 1A. This document feeding device 1 has a document tray 2 on which a document is placed and a position facing the document. In addition, a pickup roller 3 provided so as to be movable in the vertical direction, a separation unit provided downstream of the pickup roller 3, and comprising a separation pad 4 and a separation roller 5, and provided downstream of the separation roller 5. A registration roller pair 6 and 7 including a registration roller 6 and a driven roller 7 for correcting the skew of the document are provided.
[0036]
Here, the pickup roller 3 is rotatably attached to the distal end portions of the arms 19 and 20 rotatably attached to the rotation shaft 33 of the separation roller 5 shown in FIG. The arms 19 and 20 are rotated downward along with the rotation of the separation roller 5 so as to come into contact with the original.
[0037]
A document set sensor 41 is provided between the pickup roller 3 and the separation roller 5 to detect the presence or absence of documents on the document tray 2, and 42 is provided between the separation roller 5 and the registration roller pairs 6 and 7, The separation roller 5 is a pre-registration sensor for determining the conveyance amount for conveying the original to the registration roller pairs 6 and 7.
[0038]
Reference numeral 8 denotes a platen roller that is provided downstream of the registration roller pairs 6 and 7 and conveys the original while pressing it onto the platen glass 101 of the reading housing unit 100. The platen glass 101 is downstream of the platen roller 8. A pair of conveyance rollers 9 and 10 including a conveyance roller 9 for discharging the upper document and a driven roller 10 are provided. Further, downstream of the conveying roller pair 9, 10 are provided a pair of paper discharge rollers 11, 12 composed of a paper discharge roller 11 that discharges the document to the discharge tray 18 via the reverse path Pr and a driven roller. .
[0039]
Here, by having such a reversal path Pr, the discharge tray 18 can be provided above the document tray 2, so that the discharge tray 18 does not jump out of the left and right outer sides of the document feeder 1, and the document feeder 1. The installation space can be reduced. Reference numeral 13 denotes a shutter, and reference numerals 14 and 15 denote first and second shutter links that move the shutter 13 to a position where the document is locked or a position where the document is allowed to enter.
[0040]
Next, driving of each roller provided in the document feeder 1 will be described with reference to FIG.
[0041]
In the figure, reference numeral 21 denotes a drive motor, and a first pulley 23 attached to a rotating shaft 21a of the drive motor 21 is an open / close cover 51 (see FIG. 1). Provided in It is connected via a timing belt 62 to a pulley 61 on the paper feed drive shaft 43 that is the center of rotation. Further, a pulley 25 arranged at the central portion of the paper feed drive shaft 43 is connected to a pulley 26 arranged on the separation roller shaft 33 via a timing belt 27.
[0042]
The pulley 26 disposed on the separation roller shaft 33 is connected to a pulley 29 disposed on the pickup roller shaft 35 via a timing belt 30, whereby the drive motor 21 is driven via the pulley 26. Is transmitted to the pulley 29.
[0043]
Here, the rotational drive of the pulley 26 is transmitted to the separation roller 5 via the one-way clutch 24, and the one-way clutch 24 causes the separation roller 5 to rotate counterclockwise in FIG. The drive is transmitted, but is not driven clockwise.
[0044]
The pulley 29 disposed on the pickup roller shaft 35 is driven to rotate by a feed arm (front) 19 and a feed arm (back) 20 that swing about the separation roller shaft 33 via a coupling portion 32. It is transmitted to the pickup roller shaft 35 of the pickup roller 3 that is rotatably supported at the tip.
[0045]
Here, a friction member 31 is provided on the pickup roller shaft 35 between the pulley 29 and the paper feed arm (back) 20, and the friction member 31 is fed by a pressure spring (not shown) to the paper feed arm (back) 20. Is biased to the side. As a result, when the pulley 26 is rotated counterclockwise and the pulley 29 is rotated counterclockwise via the timing belt 30, the sheet feeding arm (back) 20 (and the sheet feeding arm) is caused by the sliding load of the friction member 31. (Front) 19) rotates counterclockwise (downward) about the separation roller shaft 33. As a result, when the pickup roller 3 comes into contact with the document, the pickup roller 3 is subjected to the sliding load of the friction member 31. Rotate counterclockwise.
[0046]
Further, when the pulley 26 is rotated clockwise and the pulley 29 is rotated clockwise via the timing belt 30, the sheet feeding arm (back) 20 (and the sheet feeding arm (front)) is caused by the sliding load of the friction member 31. 19) rotates in the clockwise direction (upward direction) about the separation roller shaft 33. As a result, the pickup roller 3 is separated from the document.
[0047]
Next, drive systems for the registration roller 6, the platen roller 8, the transport roller 9, and the paper discharge roller 11 will be described.
[0048]
A second pulley 22 is attached to the rotating shaft 21 a of the drive motor 21, and the second pulley 22 is connected to the pulley 63 via a timing belt 64. A one-way clutch 65 provided on the shaft 6a of the registration roller 6 is connected to the pulley 63, and the registration roller 6 is driven by the one-way clutch 65 only in the direction opposite to the driving direction to the separation roller 5. Is transmitted.
[0049]
In other words, when the drive motor 21 rotates forward, the separation roller 5 is driven counterclockwise, but is not transmitted to the registration roller 6. Further, when the drive motor 21 rotates in the reverse direction, the drive is not transmitted to the separation roller 5, but the drive is transmitted to the registration roller 6 in the clockwise direction.
[0050]
A pulley 66 is provided at one end of the shaft 6 a of the registration roller 6, and this pulley 66 is connected to a pulley 67 on the shaft 8 a of the platen roller 8 via a timing belt 68. Further, two pulleys 69 and 72 disposed at the other end of the shaft 6a of the registration roller 6 are respectively connected to a pulley 70 provided on the shaft 9a of the transport roller 9 via timing belts 71 and 74, and a paper discharge roller 11. Is connected to a pulley 73 provided on the shaft 11a. As a result, the drive of the drive motor 21 is transmitted to the transport roller 9 and the paper discharge roller 11, respectively.
[0051]
Next, the document conveying operation of the document feeder 1 having such a drive system will be described with reference to FIG.
[0052]
When a document is set on the document tray 2 with the document surface facing down, the document set sensor 41 is turned on, and a control signal (not shown) indicates that the document is on the document tray 2 by a detection signal from the document set sensor 41. Is detected. Here, when a start button (not shown) is pressed, first, the drive motor 21 rotates normally by a drive signal from the control unit, and when the pickup roller 3 descends and comes into contact with the document, the document transport direction is reached. It rotates counterclockwise and conveys the document to the separating sections 4 and 5.
[0053]
Next, the separation units 4 and 5 separate the original into a single sheet and abut against the resist roller pairs 6 and 7 that are not driven. After that, when the original forms a predetermined amount of loop, the drive motor 21 stops and the conveyance is temporarily stopped. Thereafter, the drive motor 21 is reversely rotated by the drive signal from the control unit, and the registration roller 6, the platen roller 8, the transport roller 9, and the paper discharge roller 11 are rotated.
[0054]
As a result, the document is conveyed while being in close contact with the platen glass 101, exposed by illumination means (not shown), and read. After that, when the original comes off the platen roller 8, the reading is finished, and the drive motor 21 is stopped, whereby the first original is stopped while being sandwiched between the discharge roller pairs 11 and 12.
[0055]
Next, the drive motor 21 rotates in the forward direction again according to the drive signal from the control unit and feeds the second original, and then abuts against the pair of registration rollers 6 and 7 which are not driven in the same manner as described above. A predetermined loop amount is obtained and the drive motor 21 is stopped to temporarily stop the conveyance. Thereafter, when the drive motor 21 is rotated again by the drive signal from the control unit and the registration roller 6, the platen roller 8, the transport roller 9 and the paper discharge roller 11 are rotated, the second original is read and 1 The first original is discharged onto a paper discharge tray 18 by a pair of paper discharge rollers 11 and 12.
[0056]
When the above operation is continued and the document set sensor 41 is turned OFF during the reading of the final document, the control unit detects that there is no document on the document tray 2. When it is detected that the document has run out in this way, the drive motor 21 continues to be driven even after the reading is completed, whereby the final document is discharged onto the paper discharge tray 18 by the paper discharge roller pair 11, 12. Is done.
[0057]
Incidentally, FIG. 3 is a diagram showing a configuration in the vicinity of the reading position when performing the continuous reading in the present embodiment. In FIG. 3, 56 is a reading position. An exposure device 55 of a contact-type image sensor (not shown) (not shown) is stopped immediately below the reading position, and an original image reading operation is performed by illuminating the original conveyed at this position. It is configured.
[0058]
Further, the registration rollers 6 and 7 are upstream of the reading position 56, the transport rollers 9 and 10 are downstream of the reading position 56, and the platen roller 8 that is a regulating roller is substantially above the reading position 56. Is provided with both ends rotatably supported by a swing arm 52.
[0059]
Here, the swing arm 52 receives a force acting downward by the urging member 53, so that when the document feeder 1 is opened, the swing arm 52 is equalized with the rotation fulcrum 54 as the rotation center. The platen roller 8 is pressed substantially downward.
[0060]
On the other hand, when the document feeder 1 is closed, the swing arm 52 is equalized while receiving a substantially downward force following the platen glass 101, and the platen roller 8 is positioned substantially above the reading position 56. ing. As a result, the platen roller 8 is always kept horizontal with respect to the platen glass 101, and as a result, it is possible to suppress the document swaying due to the transport load, that is, the vertical shake.
[0061]
Furthermore, the outer diameter of the swing arm 52 is slightly larger than the outer diameter of the platen roller 8, so that when the swing arm 52 hits the platen glass 101, a minute amount is formed between the platen roller 8 and the platen glass 101. A gap is formed. The surface of the platen roller 8 is coated with a low friction treatment, and therefore the platen roller 8 does not exert a document conveying force.
[0062]
By the way, in the present embodiment, the roller diameter of the registration roller 6 that is an upstream roller is configured to be equal to or larger than the roller diameter of the conveyance roller 9 that is a downstream roller, With this configuration, the document is prevented from being pulled between the registration roller 6 and the conveyance roller 9.
[0063]
Further, the roller diameter of the paper discharge roller 11 is configured to be equal to or smaller than the roller diameter of the transport roller 9, and with this configuration, the transport roller 9 and the paper discharge roller are configured. Thus, it is possible to prevent the originals from being pulled together.
[0064]
Next, the result of actually examining the roller diameter of the document feeder in the present embodiment will be described.
[0065]
In this study, the registration roller 6 and the conveyance roller 9 are created every 0.03 mm (0.2%) in consideration of the tolerance that can be created as the roller diameter tolerance, and 128 g / m. ² Cardboard and 54 g / m ² The actual image using thin paper as a document was verified to confirm the magnitude of image blurring.
[0066]
As a result, when the roller diameter of the registration roller 6 is equal to or larger than that of the conveyance roller 9, there is little image blurring. In particular, the roller diameter of the registration roller 6 is φ15.97 with respect to the roller diameter φ15.97mm of the conveyance roller 9. The result shows that the roller diameter of the registration roller 6 is preferably in the range of φ16.00 to φ16.12 mm with respect to the range of φ16.09 mm and the roller diameter of the transport roller 9 of φ16.00 mm.
[0067]
Therefore, the maximum and minimum roller diameters of the registration roller 6 and the conveyance roller 9 are 15.97 ÷ 15.97 = 1, 16.09 ÷ 15.97 = 1.008, and the conveyance roller of the registration roller 6 The roller diameter range with respect to 9 was found to be 1 to 1.008 times that of the conveying roller 9 and the relationship of the roller diameter was found.
[0068]
Therefore, in the present embodiment, the roller diameter of the registration roller 6 is φ16.06 ± 0.03 mm (φ16.03 to φ16.09 mm), and the roller diameter of the transport roller 9 is φ16.00 ± 0.03 mm (φ15.97 to φ16). .03 mm) and a tolerance within the range that can be actually created, and the relationship between the roller diameters of the registration roller 6 and the conveyance roller 9 is defined and dealt with.
[0069]
If the diameter of the registration roller 6 becomes too large, the original stops after passing through the registration roller 6 due to the difference in the conveyance speed with the conveyance roller 9 caused by the difference in diameter, so that the image blur occurs. Therefore, in order to prevent this, the ratio of the diameters of the registration roller 6 and the conveyance roller 9 is preferably in the above range.
[0070]
Further, a reverse path Pr is provided between the transport roller 9 and the paper discharge roller 11, and when passing through the reverse path Pr, the stiffness of the document becomes strong, and the roller diameter of the paper discharge roller 11 is the transport roller. If it is greater than 9, the conveying speed of the paper discharge roller 11 will increase. When the conveyance speed is increased in this way, the original roller is pulled by the conveyance roller 9 and the paper discharge roller 11, and the original is not only positioned at the shortest distance in the paper path (inside the reverse path) but also the original document. As a result, the document is pulled out from the conveying roller 9 by the waist, and as a result, the registration roller 6 and the conveying roller 9 are pulled and the image blur occurs.
[0071]
Therefore, the roller diameter of the paper discharge roller 11 is set to φ15.94 ± 0.03 mm (φ15.91 to φ15.97 mm) in consideration of the roller tolerance so that the roller diameter is surely smaller than the transport roller 9.
[0072]
As described above, the outer diameter of the registration roller 6 is equal to or larger than the outer diameter of the conveyance roller 9, and the outer diameter of the conveyance roller 9 is equal to or larger than the outer diameter of the paper discharge roller 11. And the conveyance roller 9 can be prevented from being pulled. As a result, even when the original passes through the registration roller 6, the original can be stably conveyed, and image reading with less image blur can be achieved with an inexpensive and simple configuration.
[0073]
By the way, the configuration of the image reading apparatus alone has been described so far, but it goes without saying that the present invention can also be applied to the image reading apparatus 1 provided in an image forming apparatus (digital copying machine) as shown in FIG.
[0074]
In the figure, reference numeral 400 denotes a digital copying machine, 400A denotes a digital copying machine main body (hereinafter referred to as an apparatus main body), 401 denotes an image forming unit disposed in the central portion of the apparatus main body 400A, and 301 denotes the image forming unit 401. A sheet feeding unit that conveys a sheet.
[0075]
【The invention's effect】
As described above, according to the present invention, the outer diameter of the upstream roller that conveys the document to the reading position is equal to or larger than the outer diameter of the downstream roller that conveys the document that has passed the reading position, and the downstream roller. By setting the outer diameter of the paper to be equal to or larger than the outer diameter of the paper discharge roller, the original can be stably conveyed even at the moment when the original passes through the upstream roller. It is possible to read an image with less.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of an image reading apparatus according to an embodiment of the present invention.
FIG. 2 is a drive system diagram of a document feeder provided in the image reading apparatus.
FIG. 3 is a schematic view in the vicinity of a reading position of the image reading apparatus.
FIG. 4 is a diagram illustrating a schematic configuration of an image forming apparatus including the image reading apparatus.
FIG. 5 is a diagram showing a schematic configuration of a conventional image reading apparatus.
[Explanation of symbols]
1 Document feeder
1A image reader
6 Registration roller (drive)
7 Registration Roller (Follow)
8 Platen roller
9 Transport roller (drive)
10 Conveying roller (driven)
11 Paper discharge roller (drive)
12 Paper discharge roller (driven)
21 Drive motor
56 Reading position
400 Digital copier
401 Image forming unit

Claims (3)

An image reading unit that reads an image of a document is provided, and when reading an image of the document, the image reading unit is stopped at a reading position, and the image is read by passing the document over the stopped image reading unit. An image reading apparatus configured as described above,
An upstream roller that is provided upstream of the reading position and conveys a document to the reading position;
A downstream roller that is provided on the downstream side of the reading position and conveys a document that has passed through the reading position;
A paper discharge roller for discharging the original conveyed by the downstream roller;
A curved reversing path provided between the downstream roller and the paper discharge roller;
With
In order to prevent the document from being pulled between the upstream roller and the downstream roller due to the waist of the document when the document is conveyed by the discharge roller and passes through the curved reversal path, The outer diameter of the upstream roller is larger than the outer diameter of the downstream roller, and the outer diameter of the downstream roller is larger than the outer diameter of the paper discharge roller,
An image reading apparatus. The image reading apparatus according to claim 1, wherein the regulating roller is provided above the reading position to restrict the upward movement of the document passing over the said image reading means. An image forming apparatus comprising: the image reading apparatus according to claim 1 or 2, and an image forming unit for forming an image based on image information read by the image reading apparatus.

Images