Document transport device and image reading device, image forming device

Abstract

The present invention provides a document transport device, an image reading device, and an image forming device that can stabilize the transport of documents in a oscillating guide member and suppress the deterioration of the quality of scanned images. [Solution] The reader 103 has a plurality of scooping guides 318 that scoop up the document from the scanning glass 312. The ADF 102 is movable in the thickness direction of the document and includes a platen guide 410 that guides the document at the reading position RP, a plurality of rotating members 452 provided on the platen guide 410 and positioned downstream of the reading position RP in the transport direction and arranged side by side in the width direction, and a rocking guide member 471 that is arranged alternately with the plurality of scooping guides 318. The rocking guide member 471 is positioned opposite the plurality of rotating members 452.

Description

Technical Field

[0001] The present invention relates to a document conveying device that conveys documents, and an image reading apparatus and an image forming apparatus provided with the same.

Background Art

[0002] Conventionally, an image reading apparatus mounted on an image forming apparatus such as a copying machine is known to be provided with an automatic document feeder (ADF) that conveys documents placed on a document tray one by one.

[0003] In an ADF, if speed fluctuation occurs during document reading, the quality of the read image will deteriorate, so it is particularly required to stabilize the conveyance of the document at the reading position. Accordingly, Patent Document 1 proposes a configuration that reduces the conveyance load caused by friction between the document and the conveyance guide by arranging a plurality of rotating members arranged side by side in the width direction on the conveyance guide.

Prior Art Document

Patent Document

[0004]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0005] Incidentally, in image reading apparatuses, a configuration is generally known in which the ADF is supported so as to be openable and closable relative to the reader (the main body of the image reading apparatus). In such a configuration, the ADF may be provided with a swing guide member for guiding the leading edge of the document from the reader into the interior of the ADF.

[0006] However, because the position of the oscillating guide member changes depending on the position of the ADF when it is closed, the size of the gap in the transport path formed by the oscillating guide member is unstable. As a result, there is a risk that the document may become unstable during transport due to the position of the oscillating guide member, which could degrade the quality of the scanned image.

[0007] Therefore, the present invention aims to provide a document transport device, an image reading device, and an image forming device that can stabilize the transport of documents in a rocking guide member and suppress the deterioration of the quality of scanned images. [Means for solving the problem]

[0008] To solve the above problems, one aspect of the present invention provides a document transport device that is openably and closably provided with respect to a reading unit that reads an image of a document, wherein the reading unit includes a transparent member, a reading unit that reads an image of a document transported by the document transport device through the transparent member, and a plurality of scooping guides arranged at intervals in the width direction perpendicular to the document transport direction, which scoop up and guide the leading edge of the transported document from the transparent member into the interior of the document transport device, wherein the document transport device includes a transport means for transporting the document, a transport guide member that is movable in the thickness direction of the document and guides the document at the reading position of the reading unit, a plurality of rotating members provided on the transport guide member and arranged downstream of the reading position in the transport direction, and a plurality of swinging guide members that are swingably provided and arranged alternately with the scooping when the document transport device is closed with respect to the reading unit, wherein the swinging guide members are arranged at positions opposite to the plurality of rotating members. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a document transport device, an image reading device, and an image forming device that can stabilize the transport of documents in the oscillating guide member and suppress the deterioration of the quality of the scanned image. [Brief explanation of the drawing]

[0010] [Figure 1] A schematic cross-sectional view of an image forming apparatus. [Figure 2] Perspective view of the image reading device. [Figure 3] A schematic cross-sectional view of the image reading device. [Figure 4] A diagram showing an image reading device with the ADF (Automatic Document Feeder) in the open position. [Figure 5] Enlarged cross-sectional view of the vicinity of the reading position of the image reader. [Figure 6] Perspective view of the platen guide unit. [Figure 7] A plan view of the platen guide unit, seen from below. [Figure 8] A view from above of the area near the reading position of the image reader. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the attached drawings. However, the following embodiments are merely examples of the present invention and do not limit the technical scope of the present invention.

[0012] (Image forming apparatus) First, the image forming apparatus 100 according to this embodiment will be described using Figure 1. Figure 1 is a schematic cross-sectional view of the image forming apparatus 100 as seen from the front.

[0013] As shown in Figure 1, the image forming apparatus 100 comprises an image forming apparatus body 104 that forms an image on paper P, and an image reading device 101 provided above the image forming apparatus body 104. The image forming apparatus 100 forms a toner image on paper P in response to image data read by the image reading device 101 or an image signal from a host device such as a personal computer that is communicably connected to the image forming apparatus 100. Examples of the recording medium paper P include plain paper, plastic film, and sheet materials such as cloth.

[0014] The main body 104 of the image forming apparatus contains four laser scanners 107-110 corresponding to each of the YMCK colors, four image forming units 111-114, and a fixing unit 118, all of which are image forming units using an electrophotographic method. The laser scanners 107-110 irradiate lasers onto the photoreceptors of the corresponding image forming units 111-114 according to the input image signal. These image forming units 111-114 are arranged horizontally (left-right direction in Figure 1) along the intermediate transfer belt 115.

[0015] In the image forming unit 111, a yellow toner image is formed, and the formed yellow toner image is first transferred to the intermediate transfer belt 115. In the image forming unit 112, a magenta toner image is formed, and the formed magenta toner image is first transferred onto the yellow toner image already transferred to the intermediate transfer belt 115. In the image forming unit 113, a cyan toner image is formed, and the formed cyan toner image is first transferred onto the yellow and magenta toner images already transferred to the intermediate transfer belt 115. In the image forming unit 114, a black toner image is formed, and the formed black toner image is first transferred onto the yellow, magenta, and cyan toner images already transferred to the intermediate transfer belt 115.

[0016] A paper feed cassette 105 is positioned at the bottom of the main body 104 of the image forming apparatus so as to be retractable to the front. The image forming apparatus 100 feeds the paper P contained in the paper feed cassette 105 towards the secondary transfer nip section where the intermediate transfer belt 115 and the secondary transfer section 116 come into contact, using a pickup roller 106. During the transport of the paper P, the image forming apparatus 100 transports the paper P in synchronization with the toner image on the intermediate transfer belt 115. The multi-layered toner image on the intermediate transfer belt 115 is then transferred onto the paper P in the secondary transfer nip section by the action of the secondary transfer bias voltage applied to the secondary transfer section 116.

[0017] The sheet P on which the toner image has been secondarily transferred by the secondary transfer unit 116 is conveyed to the fixing unit 118 by the conveyance belt 117. The sheet P is then heated and pressurized by the fixing unit 118 to fix the toner image, and after the toner image is fixed on the surface, the sheet P is discharged to the paper discharge tray 119.

[0018] Note that in the present embodiment, the image forming apparatus 100 includes an electrophotographic image forming unit, but the image forming unit is not limited to this, and may be another image forming unit such as an inkjet system.

[0019] (Image Reading Apparatus) Next, the image reading apparatus 101 will be described with reference to Figs. 2 to 4. Fig. 2 is a perspective view of the image reading apparatus 101. Fig. 3 is a schematic diagram showing a cross section of the image reading apparatus 101. Fig. 4 is a schematic diagram showing the image reading apparatus 101 in a state where the ADF 102 is opened.

[0020] The image reading apparatus 101 includes a reader 103 and an automatic document feeder (Auto Document Feeder, hereinafter referred to as ADF) 102. The reader 103 is attached to the upper portion of the printer main body 104. As shown in Fig. 4, the ADF 102 is supported by the reader 103 via a hinge 317, and is provided to be rotatable (openable and closable) relative to the reader 103. The ADF 102 is an example of a document conveying device that conveys documents. The reader 103 is an example of a reading unit of the image reading apparatus 101.

[0021] As shown in Fig. 3, the reader 103 includes a first reading unit 306, a flow reading glass 312, and a platen glass 316. The flow reading glass 312 is an example of a transparent member. Further, the ADF 102 includes a document tray 200, a discharge tray 202, a second reading unit 307, and a flow reading glass 313. Further, the ADF 102 includes a pickup roller 300, a separation roller pair 301, a pull-out roller pair 302, a first read roller pair 303, a second read roller pair 304, and a discharge roller pair 305. All of these conveyance rollers (300 to 305) are examples of conveyance units that convey the document D1.

[0022] The first reading unit 306 and the second reading unit 307 are examples of reading means for reading image information from a document being transported. In this embodiment, the first reading unit 306 is a CCD type image sensor unit, and the second reading unit 307 is a CIS type image sensor unit. The first reading unit 306 includes a sensor substrate 309 on which light-receiving elements are arranged in the sheet width direction, a light source 310 for irradiating light onto the document D1, and a plurality of mirrors 308 that constitute a reduction optical system for forming an optical image of the document D1 onto the light-receiving surface of the sensor substrate. The second reading unit 307 includes a CMOS sensor substrate on which light-receiving elements are arranged in the sheet width direction, a light source for irradiating light onto the document D1, and a 1:1 optical system for forming an optical image of the document D1 onto the light-receiving surface of the sensor substrate.

[0023] In this embodiment, the first reading unit 306 and the second reading unit 307, which serve as reading means, are both line sensors that acquire line images of the original document D1 at a predetermined reading cycle. The line image is a single-row image in which pixels are arranged in the sheet width direction, which is the main scanning direction. The control unit of the image reading device 101 acquires image information as two-dimensional image data by connecting the line images acquired by the first reading unit 306 and the second reading unit 307 in the sub-scanning direction (document transport direction).

[0024] The pickup roller 300 is a pickup member that feeds the document D1 from the document tray 200, which is a loading area on which the document D1 is placed. The separation roller pair 301 includes a feed roller and a separation roller. The feed roller is a feeding member that feeds the document D1 fed from the document tray 200. The separation roller comes into contact with the feed roller to form a separation nip.

[0025] A separation roller is an example of a separation member that separates sheets by applying frictional force to them. The separation roller may be a roller member supported via a torque limiter on a shaft member fixed to the frame of the ADF102. Alternatively, the separation roller may be a retard-driven roller to which a driving force in the opposite direction (clockwise in Figure 3) to the direction of movement of the original document D1 in the separation nip (original document feeding direction) is input via the torque limiter. Alternatively, instead of a separation roller, a pad-shaped elastic member (rubber pad) that contacts the feed roller may be used as the separation member.

[0026] The image reading device 101 is capable of performing an image reading operation (swimming operation) in which the first reading unit 306 and the second reading unit 307 read the image information of the document D1 while the document D1 is transported one by one by the ADF 102. When the image reading operation starts, the pickup roller 300 rotates while in contact with the uppermost document D1 on the document tray 200, and feeds the document D1 out of the document tray 200. The separation roller pair 301 transports the document D1 by the feed roller while the separation roller applies a frictional force to the document D1 in the separation nip in the opposite direction to the document feeding direction. When multiple documents D1 enter the separation nip, the separation roller restricts the passage of documents D1 other than the one document D1 that is in contact with the feed roller. As a result, the documents D1 pass through the separation nip in a separated state.

[0027] After passing through the separation nip, the original document D1 is transported sequentially by the withdrawal roller pair 302, the first lead roller pair 303, and the second lead roller pair 304. During this process, the first reading unit 306 optically scans the first side (front) of the original document D1 through the flow-reading glass 312 at the reading position RP (see Figure 5) and converts it into an electronic signal. The second reading unit 307 optically scans the second side (back) of the original document D1 through the flow-reading glass 313 and converts it into an electronic signal. This acquires image information as electronic image data. The original document D1, from which the image information has been read, is discharged from the transport path in the ADF 102 by the discharge roller pair 305 and loaded onto the discharge tray 202.

[0028] The image reading device 101 can also read image information from a stationary document placed on the reader 103. In this case, as shown in Figure 4, the user opens the ADF 102, places the document D2 on the document glass 316 of the reader 103, and then closes the ADF 102 to instruct the device to perform scanning. The first reading unit 306 then moves in the sub-scanning direction, optically scanning the document D2 to acquire image information.

[0029] (ADF document detection mechanism) Furthermore, the ADF102 has a detection means (size detection means) for detecting the size of the document. In this embodiment, the size detection means consists of a document presence sensor Sn1, a document width sensor Sn2, and a document length sensor Sn3. The document presence sensor Sn1, the document width sensor Sn2, and the document length sensor Sn3 are examples of size acquisition means that acquire information regarding the size of the document D1. The size acquisition means may also be an operation panel on which the user can input the document size.

[0030] The document presence sensor Sn1 and the document length sensor Sn3 are sensors that detect the presence or absence of a document D1 at a predetermined position on the document tray 200. The document presence sensor Sn1 is positioned near the downstream end of the document tray 200 in the document feeding direction. The document length sensor Sn3 is positioned upstream of the document presence sensor Sn1 at a predetermined distance away in the document feeding direction. Both the document presence sensor Sn1 and the document length sensor Sn3 can use reflective or transmissive optical sensors.

[0031] The document width sensor Sn2 is a sensor that detects the width of a document in the width direction perpendicular to the document feeding direction (document transport direction). As the document width sensor Sn2, an optical sensor such as a photointerrupter that detects the position of a light-shielding plate provided on the side regulating plate 201 of the document tray 200 can be used. The side regulating plate 201 is a pair of regulating members that move in conjunction with each other in the document width direction and regulate both ends of the document (Figure 2).

[0032] The control unit of the image reading device 101 determines the presence or absence of a document D1 on the document tray 200 based on the detection result of the document presence sensor Sn1. The control unit of the image reading device 101 also determines the length of the document D1 on the document tray 200 in the document width direction (hereinafter simply referred to as the document width) based on the detection result of the document width sensor Sn2. The control unit of the image reading device 101 also determines whether the length of the document D1 on the document tray 200 in the document feeding direction (hereinafter simply referred to as the document length) is greater than or equal to a predetermined length based on the detection result of the document length sensor Sn3.

[0033] (Platen guide unit configuration) Next, the configuration of the platen guide unit 400 will be explained using Figures 5 to 7. Figure 5 is an enlarged view of region A (see Figure 4) near the reading position RP. Figure 6 is a diagram showing the components that make up the platen guide unit 400. Figure 7 is a plan view of the platen guide unit 400 as seen from the transport path side (the side of the flow-read glass 312).

[0034] The platen guide unit 400 is positioned to face the slide-read glass 312 at the reading position RP of the first reading unit 306, and guides the document at the reading position RP. The platen guide unit 400 consists of a platen guide 410, a reinforcing member 420, a biasing member 430, a white member 440, and a plurality of rotating members (450, 451, 452). The platen guide unit 400 is mounted on the housing 102a of the ADF 102 so as to be movable in the thickness direction of the document (height direction, vertical direction in Figure 5), and is biased toward the slide-read glass 312 by the biasing member 430, which is a spring.

[0035] The platen guide 410 is a main component of the platen guide unit 400 and forms a guide surface that guides the original document. The platen guide 410 is an example of a transport guide member. The reinforcing member 420 is a component made of metal material that reinforces the resin platen guide 410 and prevents deformation of the platen guide 410. The white member 440 is a white plate-shaped component that serves as the background when the first reading unit 306 reads the image of the original document at the reading position RP.

[0036] The platen guide unit 400 includes a plurality of rotating members 450 positioned upstream of the reading position RP, and a plurality of rotating members 451 and 452 positioned downstream of the reading position RP. As shown in Figure 7, the plurality of rotating members 450 positioned upstream of the reading position RP consists of eight rotating members 450a to 450h, but when there is no need to distinguish between each of the rotating members 450a to 450h, they are collectively referred to as the rotating member 450. Similarly, the plurality of rotating members 451 positioned downstream of the reading position RP consists of six rotating members 451a to 451f, but when there is no need to distinguish between each of the rotating members 451a to 451f, they are collectively referred to as the rotating member 451. Likewise, the plurality of rotating members 452 positioned downstream of the reading position RP consists of three rotating members 452a to 452c, but when there is no need to distinguish between each of the rotating members 452a to 452c, they are collectively referred to as the rotating member 452.

[0037] These multiple rotating members 450, 451, and 452 are driven rollers that rotate by contacting the original document being conveyed by the first lead roller pair 303 and the second lead roller pair 304. In other words, the rotating members 450, 451, and 452 are simply rotatably mounted on the platen guide 410, and no driving force is input from a drive source such as a motor.

[0038] Here, the transport of the document in region A near the reading position RP will be described in detail. The document fed in by the pull-out roller pair 302 is held by the first lead roller pair 303 and transported along a transport path formed by the outer guide member 470 and the inner guide member 480 provided on the housing 102a of the ADF 102. Then, the document transported by the first lead roller pair 303 comes into contact with a plurality of rotating members 450 arranged in the platen guide unit 400 and is transported between the slide-read glass 312 and the white member 440. At this time, the image of the document is read by the first reading unit 306 at the reading position RP.

[0039] A scooping guide 318 is provided adjacent to the reading glass 312 of the leader 103 (to the right of the reading glass 312 in Figure 5). The scooping guide 318 has a curved surface that is higher towards the downstream side in the conveying direction, and multiple scooping guides are arranged at intervals in the width direction. In addition, a swinging guide member 471 is provided adjacent to the reading glass 312 of the outer guide member 470. The swinging guide member 471 is provided so as to be able to swing around the downstream side in the conveying direction relative to the outer guide member 470, and multiple swinging guide members 471 are arranged at intervals in the width direction.

[0040] As shown in Figure 8, the oscillating guide member 471 is positioned to fit between the multiple scooping guides 318, which are spaced apart in the width direction, when the ADF 102 is closed. In other words, when the ADF 102 is closed, the oscillating guide member 471 is positioned so that at least a portion of it overlaps with the scooping guides 318 when viewed from the width direction. To put it another way, the multiple scooping guides 318 and the multiple oscillating guide members 471 are arranged alternately in the width direction.

[0041] The upstream end of the scooping guide 318 in the transport direction is located below the upper surface of the slide-reading glass 312. Also, when the ADF 102 is closed, the upstream end of the oscillating guide member 471 in the transport direction is also located below the upper surface of the slide-reading glass 312. Therefore, the leading edge of the document that has passed the reading position RP is scooped up by the scooping guide 318 and the oscillating guide member 471 and guided into the interior of the ADF 102. At this time, the document is transported through the transport path to the second lead roller pair 304 while in contact with the rotating members 451 and 452 of the platen guide unit 400.

[0042] Thus, in this embodiment, the document comes into contact with multiple rotating members 450, 451, and 452 near the reading position RP. The multiple rotating members 450, 451, and 452 restrict the lifting of the document at the reading position RP. Therefore, the position of the platen guide unit 400 in the height direction and the transport direction greatly affects the quality of the scanned image.

[0043] Therefore, in this embodiment, the platen guide unit 400 is mounted to the housing 102a of the ADF 102 so as to be movable in the height direction. Furthermore, as shown in Figure 6, a downwardly projecting abutment portion 411 is formed on the outside of the document passage area in the width direction of the platen guide 410, and a biasing member 430 is attached above the abutment portion 411. With this configuration, the platen guide 410 is biased toward the slide-reading glass 312 by the biasing member 430, and the abutment portion 411 comes into contact with the slide-reading glass 312. This determines the height position of the platen guide unit 400 and allows the gap between the slide-reading glass 312 and the white member 440 to be maintained at an appropriate size. In addition, the position of the platen guide unit 400 in the transport direction is restricted by the contact between a projection 481 provided on the inner guide member 480 and a surface portion 415 provided on the platen guide 410.

[0044] As shown in Figure 4, when the ADF 102 is opened relative to the leader 103, the platen guide unit 400 may be exposed to the outside and detach from the housing 102a. To prevent this, the platen guide 410 has two upward-extending claw portions 416 (see Figure 6), and these claw portions 416 engage with the internal guide member 480 to prevent the platen guide unit 400 from detaching from the housing 102a.

[0045] The control unit of the image reading device 101 performs image processing such as skew correction based on the shadow of the original document in the read image. Therefore, when the first reading unit 306 reads the image of the original document, it is preferable that the shadow of the leading edge of the original document projected onto the background is dark. Accordingly, the platen guide 410 has an inclined portion 412 that is inclined downwards towards the downstream side in the transport direction, and the white member 440 that forms the background of the read image is attached to the inclined portion 412. As a result, the shadow of the leading edge of the original document projected onto the white member 440 by light from the light source 310 located upstream of the reading position RP becomes darker. In this embodiment, the inclined portion 412 is inclined at 17 degrees with respect to the horizontal direction of the reading glass 312, and the angle of the inclined portion 412 with respect to the horizontal direction is preferably 10 to 20 degrees.

[0046] As described above, the platen guide 410 has complex shapes such as abutment portion 411 and inclined portion 412, and in order to realize these shapes, the platen guide 410 is made of resin material. However, when the platen guide 410 is made of resin material, warping that occurs during molding may increase the part crossover, or deformation may occur due to the reaction force received from the original. Therefore, the platen guide unit 400 of this embodiment is provided with a metal reinforcing member 420. The reinforcing member 420 has a long shape in the width direction and has a hole portion 421 and elongated holes 422a to 422d formed therein. On the side of the platen guide 410 opposite to the transport path (back side), four protruding portions 414a to 414d are formed that protrude upward, and each is inserted into the elongated holes 422a to 422d. In addition, the two claw portions 416 described above are inserted into the elongated holes 422a and 422d, respectively. In this state, the reinforcing member 420 is fixed to the platen guide 410 by screwing screws into the hole 421 and the four protrusions 414a to 414d.

[0047] (Arrangement of the rotating member of the platen guide unit) Next, the arrangement of the multiple rotating members in the platen guide unit 400 will be described. As mentioned above, the platen guide unit 400 is rotatably mounted with multiple rotating members 450 positioned upstream of the reading position RP, and multiple rotating members 451 and 452 positioned downstream of the reading position RP.

[0048] First, the arrangement of the plurality of rotating members 450 disposed on the upstream side of the reading position RP will be described. As shown in Figure 7, in the platen guide unit 400, eight rotating members 450a to 450h are arranged side by side in the width direction as the plurality of rotating members 450, and these rotating members 450a to 450h rotate around a common first rotation axis 4501. Further, the four rotating members 450a to 450d are disposed on one side (the left side in Figure 7) with respect to the conveyance center C which is the center of the conveyance path in the width direction, and the four rotating members 450e to 450h are disposed on the other side (the right side in Figure 7) with respect to the conveyance center C. The rotating members 450a to 450d and the rotating members 450e to 450h are arranged to be symmetric with respect to the conveyance center C.

[0049] The distance L1 between the adjacent rotating member 450a and rotating member 450b at a position close to the conveyance center C is smaller than the distance L2 between the adjacent rotating member 450c and rotating member 450d at a position far from the conveyance center C (L1<L2). In other words, on one side of the conveyance center C, the distance between two adjacent rotating members is smaller as it is closer to the conveyance center C. In the present embodiment, L1=25.6[mm] and L2=35.6[mm]. The distance between two adjacent rotating members refers to the distance from the end of one rotating member to the end of the other rotating member.

[0050] Further, in the present embodiment, the distance L3 between the rotating member 450a and the rotating member 450e that are closest to the conveyance center C is 40[mm]. Further, the distance L4 between the rotating member 450b and the rotating member 450f that are second closest to the conveyance center C is 91.2[mm].

[0051] In this embodiment, documents with a width of A6 size (width 105 [mm]) or less are called "small-size documents," and documents with a width larger than A6 size are called "large-size documents." When an A6-sized document, which is a small-size document, is being transported, the multiple rotating members 450 are arranged so that four rotating members (450a, 450b, 450e, 450f) can come into contact with the document upstream of the reading position RP. Furthermore, according to the product specifications of the ADF102 in this embodiment, the smallest document size that can be transported is a business card size with a width of 48 [mm]. That is, even when the smallest transportable document is being transported, two rotating members, rotating member 450a and rotating member 450e, can come into contact with the document upstream of the reading position RP.

[0052] Furthermore, for two rotating members to contact a business card-sized document when it is being transported, the distance L3 between the rotating members 450a and 450e closest to the transport center C should be 48 mm or less. Also, for four rotating members to contact an A6-sized document when it is being transported, the distance L4 between the rotating members 450b and 450f second closest to the transport center C should be 105 mm or less.

[0053] Next, the arrangement of the multiple rotating members 451 and 452 located downstream of the reading position RP will be described. As shown in Figure 7, the platen guide unit 400 has six rotating members 451a to 451f arranged in the width direction as multiple rotating members 451, and these rotating members 451a to 451f rotate around a common second rotation axis 4502. In addition, the platen guide unit 400 has three rotating members 452a to 452c arranged in the width direction as multiple rotating members 452, and these rotating members 452a to 452c rotate around a common third rotation axis 4503.

[0054] The three rotating members 452a to 452c are positioned downstream in the conveying direction from the six rotating members 451a to 451f, and are positioned so that a portion of rotating member 451 and rotating member 452 overlap when viewed from the direction of the rotation axis. The six rotating members 451a to 451f are an example of multiple first rotating members. The three rotating members 452a to 452c are an example of multiple second rotating members. The eight rotating members 450a to 450h described above are an example of multiple third rotating members.

[0055] In this embodiment, the distance L5 between the rotating member 451a and the rotating member 451d, which are the closest to the transport center C among the multiple rotating members 451, is 46.8 [mm]. In addition, the rotating member 452a is positioned at the transport center C. That is, even when the smallest possible document is being transported, the three rotating members, rotating member 451a, rotating member 451d, and rotating member 452a, can contact the document downstream of the reading position RP.

[0056] Furthermore, when a large-sized document such as A3 size (width 297 [mm]) is being transported, all of the rotating members 450a-450h, 451a-451f, and 452a-452c will come into contact with the document.

[0057] (Positional relationship between the rocking guide and the rotating member) Next, the positional relationship between the oscillating guide member provided on the outer guide member 470 of the ADF 102 and the multiple rotating members 452 will be described. As described above, the multiple scooping guides 318 and the multiple oscillating guide members 471 are arranged alternately in the width direction at a position adjacent to the reading glass 312. The multiple rotating members 452a to 452c are positioned to overlap with the multiple oscillating guide members 471 in the transport direction. Also, when the ADF 102 is viewed from below, the multiple rotating members 452a to 452c overlap with the multiple oscillating guide members 471 in at least part. In other words, the multiple oscillating guide members 471 are positioned opposite the multiple rotating members 452a to 452c.

[0058] (Summary of this embodiment) As described above, in the present embodiment, the distance L1 between the adjacent rotating member 450a and rotating member 450b located at a position close to the conveyance center C is smaller than the distance L2 between the adjacent rotating member 450c and rotating member 450d located at a position far from the conveyance center C (L1<L2). Accordingly, even when a small-size document is conveyed, more rotating members come into contact with the document, so that the conveyance of the small-size document can be stabilized.

[0059] Further, in the present embodiment, the distance L3 between the rotating member 450a and the rotating member 450e that are closest to the conveyance center C is smaller than the width of the minimum size document that can be conveyed. Accordingly, even when a document of the minimum size is conveyed, a plurality of rotating members come into contact with the document, so that the conveyance of the minimum size document can be stabilized.

[0060] Further, the plurality of rotating members 450a to 450h are arranged symmetrically with respect to the conveyance center C. Accordingly, the conveyance load applied to the document in the width direction can be made substantially uniform, and skewing of the document can be suppressed.

[0061] Since the swing guide members 471 are arranged alternately with the plurality of scooping guides 318, the leading edge of the document can be smoothly guided from the flow reading glass 312 into the interior of the ADF 102. In addition, since the swing guide member 471 is provided so as to be swingable, when the ADF 102 is closed, the swing guide member 471 comes into contact with the upper surface of the reader 103 and assumes an appropriate posture for conveyance. On the other hand, since the swing guide member 471 is swingable, the size of the gap in the conveyance path formed by the swing guide member 471 is not stable. For example, when the gap in the conveyance path formed by the swing guide member 471 is large, the document may be lifted, which may adversely affect the read image.

[0062] However, in this embodiment, the multiple rotating members 452a to 452c are positioned opposite the multiple oscillating guide members 471. This makes it possible to reduce the gap in the transport path of the oscillating guide members 471, thereby stabilizing the transport of the document. [Explanation of Symbols]

[0063] 100 Image forming apparatus 101 Image reading device 102 ADF 103 Leader 104 Image forming apparatus main unit 400 Platen Guide Unit 450, 451, 452 Rotating members 471 Swivel guide member

Claims

1. A document transport device that is provided so as to be openable and closable with respect to a reading unit that reads an image of a document, The reading unit is, Transparent material and A reading unit that reads the image of a document being transported by the document transport device via the transparent member, It includes multiple scooping guides, which are arranged at intervals in the width direction perpendicular to the document transport direction, and which scoop up and guide the leading edge of the transported document from the transparent member into the interior of the document transport device, The aforementioned document transport device, A means of transporting the manuscript, A transport guide member that is movable in the thickness direction of the document and guides the document at the reading position of the reading unit, A plurality of rotating members are provided on the transport guide member and are arranged downstream of the reading position in the transport direction, It includes a plurality of swingable guide members, which are swingably mounted and arranged so as to be alternating with the scooping mechanism when the document transport device is closed to the reading section, The swing guide member is positioned opposite to the plurality of rotating members. A document transport device characterized by the following features.

2. The aforementioned plurality of rotating members are A plurality of first rotating members are arranged in the width direction downstream of the reading position in the transport direction, It includes a plurality of second rotating members, which are arranged downstream in the transport direction from the plurality of first rotating members and aligned in the width direction, and which are arranged so as to partially overlap the plurality of first rotating members when viewed from the width direction, The swing guide member is positioned among the plurality of rotating members opposite to the plurality of second rotating members. The document transport device according to feature 1.

3. The transport guide member has a plurality of third rotating members arranged in the width direction upstream of the reading position in the transport direction. The document transport device according to feature 2.

4. The aforementioned plurality of rotating members are arranged symmetrically with respect to the center of the transport path. The document transport device according to feature 1.

5. The aforementioned transport guide member is made of resin material, and a metal reinforcing member is attached to the side opposite to the transport path. The document transport device according to feature 1.

6. The transport guide member has an inclined portion that is inclined downwards towards the downstream side in the transport direction at the reading position. The document transport device according to feature 1.

7. A document transport device that is provided so as to be openable and closable with respect to a reading unit that reads an image of a document, The reading unit is, Transparent material and A reading unit that reads the image of a document being transported by the document transport device via the transparent member, It includes multiple scooping guides, which are arranged at intervals in the width direction perpendicular to the document transport direction, and which scoop up and guide the leading edge of the transported document from the transparent member into the interior of the document transport device, The aforementioned document transport device, A means of transporting the manuscript, A transport guide member that is movable in the thickness direction of the document and guides the document at the reading position of the reading unit, A plurality of rotating members are provided on the transport guide member and are arranged downstream of the reading position in the transport direction, It includes a plurality of swingable guide members, which are provided to swing and are arranged such that, when the document transport device is closed to the reading unit, at least a portion of them overlap with the scooping mechanism when viewed from the width direction, The swing guide member is positioned opposite to the plurality of rotating members. A document transport device characterized by the following features.

8. A document transport device according to any one of claims 1 to 7, A reading unit having the aforementioned reading unit and rotatably supporting the document transport device, An image reading device characterized by the following.

9. The image reading device according to claim 8, The system includes an image forming means that forms an image on paper based on the image of the original document read by the reading unit. An image forming apparatus characterized by the following:

Images