JP6452408B2 - Sheet conveying apparatus, image reading apparatus, and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet conveying apparatus that conveys a sheet, an image reading apparatus that reads an image of the conveyed sheet, and an image forming apparatus.

  In general, in an image forming apparatus such as a copying machine or a facsimile, a sheet feeding device such as a document feeding device feeds a sheet such as a document from a stacking tray to a separation unit by a pickup roller, and the separation unit feeds the sheets one by one. It has a configuration for feeding. Some image forming apparatuses include an image reading apparatus that optically reads a document image. Some of these image reading apparatuses include an automatic document feeder (Auto Document Feeder (hereinafter referred to as “ADF”)) that conveys documents one by one to an image reading unit.

  As the image reading means, a “fixed reading method” and a “flow-reading method” are employed independently or in combination, respectively. The “fixed reading method” is a method of reading an image by placing an original on the platen glass and then scanning the placed original by an image reading unit. The “flow-reading method” is a method in which an image reading unit fixed at a fixed position facing a flow-reading glass provided on a document transport path reads a document transported by the ADF. In particular, the flow scanning method using the ADF has an advantage of high productivity because a large amount of images of a document can be read by one operation. For this reason, the image reading method has become the mainstream in monochrome copying machines and color copying machines.

  However, in the case of the flow-reading method, the image reading unit is fixed at a fixed position facing the flow-reading glass, and the reading optical system is focused on the transported original document surface through the flow-reading glass. Susceptible to foreign matter such as residual and attached dust and paper dust. For example, when there is foreign matter on the flow reading glass, there is an image defect problem that a portion shielded by the foreign matter appears as linear image noise (hereinafter referred to as “image streak”) in the read image. . Examples of foreign matters that cause image streaks include paper dust generated from a document, scraped scraps of a conveyance roller, ink attached to a document, toner, and graphite.

  In order to solve the above problems, conventionally, in the process of processing the scanned image, a foreign object on the image is detected and a warning is issued to the user, the image processing is performed to erase the image streak, and the flow scanning glass is moved. Measures have been taken, such as reading by avoiding foreign objects. However, these measures cannot prevent the accumulation of foreign matters on the flow-reading glass, which is the root cause, and have a limited effect and are insufficient as measures.

  Therefore, an image forming apparatus having the following configuration has been proposed from the viewpoint of reducing the amount of foreign matter such as paper dust generated by document conveyance falling into the document (sheet) conveyance path (see Patent Document 1). . In this image forming apparatus, the surface of one roller (electrostatic roller) of a pair of transport rollers is coated with a fluororesin to form an insulating layer, and static electricity is generated on this insulating layer. Adsorb foreign substances such as. Furthermore, a foreign object is separated from the electrostatic roller by bringing a scraper made of a PET film or the like into contact with the electrostatic roller and collected in a box.

  In addition, an image reading apparatus configured to rotate an elastic cleaning member on a flow reading glass has been proposed (see Patent Document 2). In this image reading apparatus, the cleaning member has an elastically deformable cleaning brush fixed to the flat surface of the shaft member in a line shape in the width direction orthogonal to the document conveying direction, and has a predetermined timing and a predetermined speed. It is configured to be driven forward or reverse. The cleaning member is implanted with conductive polyimide resin as a cleaning brush, and the cleaning brush that rotates on the flow-reading glass and adsorbs the foreign matter is struck by the scrubbing member on the downstream side in the document transport direction. It is wiped off downstream of the reading position. Furthermore, the foreign matter is caught in a document conveyed on the flow reading glass and discharged to the outside of the apparatus, so that the surface of the flow reading glass corresponding to the reading position can be cleaned, and image streaking is reduced. It becomes possible to do.

JP-A-8-133514 JP 2010-89851 A

  However, according to the technique described in Patent Document 1, when the foreign matter adsorbed by the electrostatic roller cannot be recovered by the scraper, the roller that is paired with the electrostatic roller does not hold the document while holding the document. Foreign matter moves. In this case, there is a risk that the amount of foreign matter on the side of the document on which foreign matter is not collected increases. For example, when electrostatic rollers are arranged on the front surface side when reading on both sides, a phenomenon that image streaks increase in an image related to the back surface side may occur.

  Moreover, according to the technique described in Patent Document 2, there are the following problems. That is, in this technique, the foreign material is collected by the cleaning member directly above the flow reading glass. However, when the user opens and closes the ADF, there is a possibility that the foreign material such as an adhesive adheres to the flow reading glass. is there. If the ADF flow reading is performed thereafter, an adhesive may adhere to the cleaning member, and thereafter, the cleaning member may continuously cause the flow reading glass to become dirty. In addition, according to this technology, there are many control restrictions such as rotating the cleaning member by a certain angle at a certain timing, and the apparatus configuration, the sensor for recognizing the position of the cleaning member, and the cleaning member itself must be provided. Therefore, there is a risk of increasing the size and cost of the apparatus.

  The present invention has a simple structure, but does not cause a phenomenon that foreign matter moves to the opposite roller, reduces control restrictions, simplifies the structure, and avoids an increase in apparatus size and cost. An object is to provide an apparatus, an image reading apparatus, and an image forming apparatus.

The present invention provides a sheet conveying apparatus having a pair of conveying guides that are opposed to each other with a gap therebetween, a sheet conveying path that can convey a sheet between the pair of conveying guides, and one side of the pair of conveying guides A rotating body that rotates by allowing a part of the outer peripheral surface to enter the sheet conveying path, and a collecting unit that collects foreign matter adhering to the outer peripheral surface in contact with the sheet conveyed through the sheet conveying path; The other of the pair of transport guides is an upstream side and a downstream side in a sheet transport direction within a range of a sheet length to be transported, in a portion facing the outer peripheral surface entering from the one transport guide And the sheet conveyed through the sheet conveyance path is pressed against the rotating body by the convex part .

  According to the present invention, while having a simple configuration, it is possible to reduce control restrictions, simplify the configuration, and avoid an increase in size and cost of the device without causing a phenomenon that foreign matter moves to the opposite roller. It becomes possible.

1 is a cross-sectional view schematically showing an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a block diagram illustrating a control system of the image forming apparatus according to the first embodiment. 1 is a perspective view illustrating an image reading apparatus according to a first embodiment. FIG. 4 is a cross-sectional view of the image reading apparatus shown in FIG. 3 at the time of flow reading shown in a cross-sectional view taken along the line D-D in FIG. Sectional drawing which shows FIG. 4 in the state at the time of fixed reading. Sectional drawing which shows the detail of the collection | recovery part which concerns on this embodiment. Sectional drawing which shows the detail of the collection | recovery part which concerns on the 2nd Embodiment of this invention.

<First Embodiment>
Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. The image forming apparatus according to the present embodiment can be configured from a copying machine, a multifunction machine, or the like, and includes an image reading apparatus having a document feeding device capable of feeding a document (sheet-like document) to an image reading unit. .

[Image forming apparatus]
First, a schematic configuration of the image forming apparatus 100 according to the present embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view schematically showing an image forming apparatus 100 according to the present embodiment. In the following description, a position where a user faces an operation unit (not shown) that performs various inputs and settings on the image forming apparatus 100 is referred to as “front side” of the image forming apparatus 100, and a rear side is referred to as “back side”. . That is, FIG. 1 shows the internal configuration of the image forming apparatus 100 viewed from the front side.

  As shown in FIG. 1, the image forming apparatus 100 includes an image reading apparatus 200 that can read an image of a document G as a sheet stacked on the document stacking tray 221, and an image read by the image reading apparatus 200. The apparatus main body 10 is formed. Further, the image forming apparatus 100 includes a control unit 50 as a control unit that controls the image reading apparatus 200 and the apparatus main body 10.

  The image reading apparatus 200 includes a scanner unit 210 that reads an image of a document (sheet document) G, and an automatic document feeder (hereinafter referred to as ADF) 220 that can automatically feed the document G to the scanner unit 210. And. The scanner unit 210 and the ADF 220 will be described in detail later.

  The apparatus main body 10 includes an image forming unit 20 that forms an image on a sheet S that is a recording medium, and a sheet feeding unit 30 that feeds the sheet S to the image forming unit 20. Further, the apparatus main body 10 includes a discharge roller pair (discharge section) 40 that discharges the sheet S on which an image is formed to the outside of the apparatus main body 10 (outside the apparatus), a sheet discharge tray 45 on which the discharged sheets S are stacked, have.

  The image forming unit 20 fixes the toner image, the photosensitive drum 22 on which the toner image is formed, the laser scanner unit 21 that irradiates the photosensitive drum 22 with laser light, the transfer unit 24 that transfers the toner image to the sheet S, and the toner image. And a fixing unit 25. A registration roller pair 11 is disposed upstream of the transfer unit 24 in the sheet conveyance path 36. Reference numeral 12 denotes a reverse conveyance path. The image forming unit 20 constitutes an image forming unit that forms an image on the sheet S based on image information read from the original G by the image reading device 200.

  The sheet feeding unit 30 in the sheet conveying device 34 separates the sheets S one by one, a sheet feeding cassette 31 on which the sheets S are stacked, a feeding roller 32 that feeds the sheets S in the sheet feeding cassette 31, and the sheet S. It has a conveyance roller 33a and a separation roller 33b for conveyance. Reference numeral 35 denotes a manual feed tray for manually feeding the sheet S.

  Next, the control system in the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram showing a control system of the image forming apparatus 100.

  As shown in FIG. 2, the control unit 50 as a control unit includes an ADF 220 having motors M1, M2, M3, and M4, a scanner unit 210 having a motor M5, each operation unit of the image forming unit 20, and a sheet feeding unit. 30 operating parts, a discharge roller pair 40 and the like are connected. The control unit 50 includes a CPU 51 that controls these units, and a memory 52 such as a ROM and a RAM that store various programs such as an image reading program and an image forming program, and various types of information.

  The control unit 50 controls the motor M1 so that the first platen roller 237 has a predetermined rotational speed. The controller 50 controls the motors M2 and M3 to drive the third transport roller pair 236 and the fourth transport roller pair 238 (see FIG. 4). The control unit 50 controls the motor M4 to rotate the second transport roller pair 234 and the foreign matter removal roller 211 of the collection unit (collection unit) 201 in the same direction at the same outer peripheral speed. The control unit 50 operates other rollers including the registration roller pair 235 by controlling a motor (not shown). Further, the control unit 50 controls the motor M5 so as to drive the first scanner unit 253 (see FIG. 4) of the scanner unit 210. Further, the control unit 50 controls the image forming unit 20, the sheet feeding unit 30, and the discharge roller pair (discharge unit) 40, respectively.

  Next, an image forming operation (image forming control by the control unit 50) of the image forming apparatus 100 under the control of the control unit 50 will be described with reference to FIG. Here, an image forming operation for forming an image on the sheet S based on the image information of the original G automatically fed by the ADF 220 and read by the scanner unit 210 will be described. The image reading operation by the image reading apparatus 200 (image reading control by the control unit 50) will be described in detail later.

  That is, when image information of the original G fed by the ADF 220 shown in FIG. 1 and read by the scanner unit 210 is input, the laser beam is applied from the laser scanner unit 21 to the photosensitive drum 22 based on the input image information. Is irradiated. At this time, the photosensitive drum 22 is charged in advance via the charger 27, and an electrostatic latent image is formed by irradiation with laser light. The electrostatic latent image is developed by the developing device 23 and formed as a toner image on the photosensitive drum 22.

  In parallel with the toner image forming operation on the photosensitive drum 22, the sheet S stored in the sheet feeding cassette 31 of the sheet feeding unit 30 is fed by the feeding roller 32. The sheets S fed by the feeding roller 32 are nipped by a separation nip portion between the conveyance roller 33a and the separation roller 33b, and are separated and conveyed one by one.

  The sheets S separated one by one are synchronized with the toner image on the photosensitive drum 22 by the registration roller pair 11 and are sent to the transfer unit 24. The toner image on the photosensitive drum 22 is transferred to the sheet S sent to the transfer unit 24 by the transfer unit 24.

  The sheet S to which the toner image has been transferred is heated and pressed by the fixing unit 25, and the toner image is melted and fixed to the sheet S. The sheet S on which the toner image is fixed is discharged to the sheet discharge tray 45 by the discharge roller pair 40 and is sequentially stacked. When images are formed on both sides of the sheet S, after the image is fixed on the first side of the sheet S, the sheet S is re-conveyed toward the registration roller pair 11 via the reverse conveyance path 12. The above operation is repeated.

[Image reading device]
Next, the image reading apparatus 200 will be described with reference to FIGS. 3 is a perspective view of the image reading apparatus 200 according to the present embodiment, and FIG. 4 is a cross-sectional view of the image reading apparatus 200 shown in FIG. It is sectional drawing at the time of flow reading shown by. FIG. 5 is a cross-sectional view showing FIG. 4 in a fixed reading state.

  As shown in FIGS. 3 to 5, the image reading apparatus 200 includes a scanner unit 210 and an ADF 220 that is disposed on the scanner unit 210 and includes a document conveying device (sheet conveying device) 208. Further, in the image reading apparatus 200, the ADF 220 is rotatably supported by the scanner unit 210 by a hinge (not shown) disposed on the back side so that a later-described original platen glass 213 can be opened and closed. ing. Hereinafter, the scanner unit 210 and the ADF 220 will be specifically described.

  The scanner unit 210 includes a first scanner unit 253 that reads an image on the first surface of a document (sheet) G. Further, the scanner unit 210 includes a first flow reading glass (platen glass) 209 as a transparent member, and a first plate reading glass 209 and an original table glass 213 arranged side by side in the sub-scanning direction (left-right direction in FIG. 4). have.

  For the first scanner unit 253, for example, a contact image sensor (hereinafter referred to as CIS (Contact Image Sensor)) of an equal magnification optical system is used. The first scanner unit 253 includes an illumination 310 that irradiates light on an image surface of a document, mirrors 301, 302, and 303 that guide reflected and scattered light from the document irradiated by the illumination 310 to an imaging lens 304, and a charge coupled device. 305 and the like. In the CIS, light is emitted from an LED array as a light source to the image information surface of the original G, and reflected light reflected by the image information surface is formed on a sensor element to read image information.

  The first scanner unit 253 is connected to a motor M5 (FIG. 2) of the scanner unit 210 via a timing belt (not shown). The first scanner unit 253 is driven by the motor M5, and the position C below the first flow reading glass 209 shown in FIG. 4, the position A below the first flow reading glass 209 shown in FIG. 5, and the original shown in FIG. It is configured to be movable between a position B below the table glass 213.

  Further, the position of the first scanner unit 253 can be grasped by the control unit 50 based on a position sensor (not shown) and the number of rotation pulses of the motor M5. The first scanner unit 253 constitutes an image reading unit that reads image information from a document (sheet) G conveyed by the document conveying device 208.

  In the present embodiment, a mode in which an image is read while the original G is moved on the first flow reading glass 209 by the ADF 220 while the first scanner unit 253 is stopped at the position C in FIG. Method). In addition, a form in which the original G is placed on the original platen glass 213 and the first scanner unit 253 is moved in the direction of the arrow X in FIG. 5 from the position A to the position B in FIG. "Reading".

  In reading the original image by the fixed reading method, the first scanner unit 253 waiting for the original placed on the original platen glass 213 at the position A in FIG. This is done by operating at a constant speed in the direction of arrow X up to position B and reading the image. Reading the original image by the flow reading method is performed by causing the first scanner unit 253 to stand by at the position C in FIG. 4 and reading the image when the original is conveyed at a constant speed by the ADF 220 at the image reading position 91.

  As shown in FIGS. 3 to 5, the ADF 220 includes a document stacking tray 221 on which a document (sheet) G for flow reading is stacked, a document transport path (sheet transport path) 41 on which the document G is transported, A document discharge unit 223. In the document conveyance path 41, the document G is conveyed toward the image reading position 91 when being scanned. On the document discharge unit 223, the flow-read original G is discharged and stacked. The ADF 220 is configured so that the original G can be pressed by a resin plate (not shown) so that the original G placed on the original table glass 213 does not move during fixed reading.

  As shown in FIGS. 4 and 5, in the document transport path 41 of the document transport device 208, a document feeding roller 231 that feeds the document G stacked on the document stacking tray 221 and the document G one by one. A separation roller pair 232 for separation is arranged. Further, a second conveyance roller pair 234 that conveys the original G, a third conveyance roller pair 236, a fourth conveyance roller pair 238, and a fifth conveyance roller pair 240 are arranged in the document conveyance path 41. .

  Further, a registration roller pair 235, a first platen roller 237, and a discharge roller pair 241 are disposed in the document conveyance path 41. A collection unit (collection unit) 201 is disposed in the curved conveyance unit Hw between the second conveyance roller pair 234 and the registration roller pair 235. The registration roller pair 235 is disposed between the second conveyance roller pair 234 and the third conveyance roller pair 236 and corrects (corrects) the skew of the original G.

  The first platen roller 237 is provided on the opposite side of the first flow reading glass 209 and biases the conveyed original to the first flow reading glass 209 when reading the image on the first surface (front surface) of the conveyed original. The first platen roller 237 is disposed immediately above the glass so as to face the first flow reading glass 209 between the third conveyance roller pair 236 and the fourth conveyance roller pair 238. When the first platen roller 237 reads an image on the first surface of the document G, the first platen roller 237 conveys the document G with a predetermined interval from the first flow reading glass 209.

  The first platen roller 237 is disposed so as to face the first scanner unit 253 through the first flow reading glass 209 at the image reading position 91. The first platen roller 237 holds the document G from the second surface side and suppresses lifting from the first flow reading glass 209. Further, the discharge roller pair 241 is disposed downstream of the fifth transport roller pair 240 and discharges the document G after image reading to the document discharge unit 223.

  In the present embodiment, since the dual scan ADF is employed, the document transport path 41 has the following members on the downstream side in the document transport direction from the first scanner unit 253 and the first flow reading glass 209. . That is, the second scanner unit 251 that reads an image on the second surface of the original G, the second flow reading glass (platen glass) 252, and the original G is conveyed at a predetermined interval with respect to the second flow reading glass 252. And a second platen roller 239. The second platen roller 239 is provided on the opposite side of the second flow reading glass 252 and biases the conveyed original to the second flow reading glass 252 when reading an image on the second surface (back surface) of the conveyed original.

  Here, the CIS is used for the second scanner unit 251 similarly to the first scanner unit 253. The second scanner unit 251 passes through the document conveyance path 41 at a second reading position 92 facing the second flow reading glass 252 provided downstream in the document conveyance direction (sheet conveyance direction) of the first scanner unit 253. The image on the second side of the conveyed document G is read.

[Image reading operation]
Next, an image reading operation (image reading control by the control unit 50) by the flow reading method by the image reading apparatus 200 having the above-described configuration will be described with reference to FIG.

  When reading by the flow reading method, the user places a document on the document stacking tray 221 with its surface facing upward. A document size detection sensor (not shown) is arranged on the document stacking tray 221 so that the vertical and horizontal sizes of the document can be recognized. The control unit 50 reads an image of a document as described later according to the recognized document size.

  First, an arbitrary number of documents G placed on the document stacking tray 221 are fed by the document feeding roller 231 and separated one by one at the separation nip portion of the separation roller pair 232. The separated original G is pulled out by the first transport roller pair 234 and then transported to the nip portion of the registration roller pair 235 by the first transport roller pair 234.

  When the original G reaches the nip portion of the registration roller pair 235, the registration roller pair 235 is kept stationary so that the leading edge of the original G is brought into contact with the nip portion and stopped. In this state, the original G is bent by a predetermined amount by the first conveying roller pair 234 on the upstream side in the original conveying direction, whereby the original G is bent to generate a curved shape.

  Here, when the document G is skewed, the leading edge of the document G is inclined with respect to the main scanning direction (the width direction orthogonal to the document transport direction), but the stiffness (rigidity) of the document G due to the above-described curve. Thus, the leading edge of the document follows the nip line of the registration roller pair 235 parallel to the main scanning direction. Thereby, the inclination of the leading edge of the document is eliminated. In this way, the skew of the original G is corrected by the registration roller pair 235.

  After the skew correction, the conveyance of the original G by the registration roller pair 235 is started, and the original G is further conveyed downstream by the third conveyance roller pair 236 to reach the image reading position on the first flow reading glass 209. To reach. Then, the first scanner unit 253 reads the image on the first surface of the document G at a predetermined speed.

  Thereafter, the original G is conveyed by the fourth conveying roller pair 238. In that case, if the user instructs to read the second side of the document G, the control unit 50 controls the first side reading and then the second reading glass 252 at the image reading position at the image reading position. 2 The image reading of the second surface of the document G is performed at a predetermined speed by the scanner unit 251.

  Further, the original G after image reading is discharged to the original discharge unit 223 by the fifth conveying roller pair 240 and the discharge roller pair 241. Then, the above-described operation is repeated until there are no more documents G placed on the document stacking tray 221. The presence / absence of the document G placed on the document stacking tray 221 can be detected by a sensor (not shown).

[Details of collection unit]
Next, details of the collection unit (collection unit) 201 for collecting foreign matter in the present embodiment will be described with reference to FIGS. 4 and 6.

  That is, the following members are arranged in the curved conveyance portion Hw between the second conveyance roller pair 234 and the registration roller pair 235 in the document conveyance path 41 shown in FIG. That is, a single foreign matter removing roller (rotating body) 211 that rotates by driving a part of the original from the one side into the document conveying path 41 (in the sheet conveying path) and a collecting unit (collecting means) 201 are arranged. Has been.

  The collecting unit 201 comes into contact with the document conveyed on the document conveyance path 41 from the document stacking tray 221 through the document feeding roller 231, the separation roller pair 232, and the second conveyance roller pair 234, thereby allowing the outer periphery of the roller 211 to be contacted. The foreign material k adhering to the surface 211a from the original G is collected. This makes it possible to solve problems caused by foreign matters such as paper dust during sheet conveyance, such as the occurrence of image streaks during image reading by the flow reading method, with a simple configuration.

  As shown in FIGS. 4 and 6, the foreign matter removing roller 211 and the collecting unit 201 include a pair of first conveyance guides (one conveyance guide) 205 and second conveyance guides (one conveyance guide) 205 that face each other with a gap in the document conveyance path 41. It is provided at a position corresponding to the other conveyance guide 206). The document transport path 41 is configured to transport the document G between the first and second transport guides. The collection unit 201 is disposed at a substantially intermediate position between the second conveyance roller pair 234 and the registration roller pair 235 in the conveyance guides 205 and 206.

  As will be described later, the second transport guide 206 has a shape that allows the document G transported through the document transport path 41 to come into contact with the foreign matter removing roller 211 while increasing the rigidity. That is, the curved conveyance unit Hw is formed to bend downward to guide the document G to the image reading position 91, and the foreign matter removing roller 211 and the collection unit 201 are outside the curved conveyance unit Hw. Is arranged. The foreign matter removing roller 211 is positioned so that a part thereof enters from a notch 205a provided in the first transport guide 205 located on the outer diameter side of the curvature radius r in the curved transport section Hw.

  The first conveyance guide 205 positioned on the outer diameter side of the curvature radius r contacts the outer peripheral surface 211a entering the curved conveyance unit with the document G being curved and conveyed along the second conveyance guide 206. To function. In this case, since the foreign matter removing roller 211 is disposed outside the curved conveyance portion Hw, the conveyed document G is always pressed against the outer peripheral surface 211a of the foreign matter removing roller 211, and the foreign matter k can be stabilized. Can be adsorbed.

  The notch 205a is formed at a predetermined position of the conveyance guide 205 so that a part of the outer peripheral surface 211a of the foreign matter removal roller 211 of the collection unit 201 enters the curved conveyance unit Hw. The notch 205a extends so as to be slightly longer than the axial length of the foreign matter removing roller 211 in the front-back direction of FIG. In other words, the foreign matter removing roller 211 is configured as a roller that can face the entire region in the width direction (front-back direction in FIG. 6) orthogonal to the transport direction of the document G transported through the document transport path 41.

  Thus, the foreign matter removing roller 211 is longer than the width direction of the document G that can be transported by the document transport device 208 in the roller axial length, and is disposed over substantially the entire region including the dimensions in the width direction of the specification document. The For this reason, if the document has a size that can be used by the image forming apparatus 100, the foreign matter k attached to the entire first surface of the document can be effectively removed by the foreign matter removing roller 211.

  The recovery unit 201 includes a scraping member 212 as a contact member that contacts the outer peripheral surface 211a of the foreign matter removing roller 211, and a storage member 214 that stores the foreign matter k that is peeled off from the outer peripheral surface 211a by the contact of the scraping member 212. Have. The housing member 214 is provided so as to extend in the axial direction of the foreign matter removing roller 211. The housing member 214 is supported by the apparatus main body of the ADF 220. With this configuration, it is possible to reliably prevent the removed foreign matter k from scattering into the apparatus by storing the removed foreign matter in the storage member.

  The scraping member 212 is also configured as a charging member that makes contact (sliding contact) with the outer peripheral surface 211a of the foreign matter removal roller 211 to frictionally charge the foreign matter removal roller 211, and scrapes the foreign matter k electrostatically attracted to the outer peripheral surface 211a. Remove.

  The scraping member 212 is formed in a plate shape such as a rubber material that is long in the front-back direction of FIG. 6 and extends in the axial direction of the foreign matter removing roller 211. The accommodating member 214 is also configured to have an equivalent length so as to correspond to the scraping member 212 extending in the axial direction of the foreign substance removing roller 211. Thereby, the scraping member 212 is brought into contact with the entire area in the axial direction (main scanning direction) of the foreign matter removing roller 211, and the foreign matter k adsorbed on the outer peripheral surface 211a of the foreign matter removing roller 211 can be efficiently collected.

  The foreign matter removing roller 211 is made of a resin member. That is, the material of the foreign matter removing roller 211 is made of a resin material such as ABS, PET, PE, PP, PS, and PTFE (fluororesin). Alternatively, it is also possible to apply resin coating or fluorine coating to the outer peripheral surface 211a of the foreign matter removing roller 211. As described above, when at least the outer peripheral surface 211a of the foreign matter removing roller (rotating body) 211 is made of a resin member, the roller surface is easily charged and the foreign matter removing performance is improved.

  The housing member 214 shown in FIG. 6 includes an inclined portion 214a that inclines so as to descend from the wall portion 214e toward the foreign matter removing roller 211, a wall portion 214b that protrudes upward from the opposite side of the wall portion 214e, and an inclined portion 214a. And a notch 214c provided between the walls 214b. The housing member 214 is positioned and fixed to the apparatus main body of the ADF 220 with the lower part of the foreign matter removing roller 211 entering the inclined lower side of the notch 214c. The rear end of the scraping member 212 is fixed to the front end of the inclined portion 214a in this state, and the front end of the scraping member 212 is in contact with the foreign matter removing roller 211. In other words, the foreign matter removing roller 211 is positioned obliquely in a direction against the rotation of the foreign matter removing roller 211 rotating in the clockwise direction (the direction of arrow I) in FIG. 6 and is fixed to the inclined portion 214a.

  The storage member 214 is configured to receive and store the foreign matter k scraped by the scraping member 212 at the bottom 214d below the scraping member 212. The accommodating member 214 may have another shape as long as it has a shape and configuration that collects the foreign matter k adsorbed on the outer peripheral surface 211a of the foreign matter removal roller 211 and does not drop the collected foreign matter k. Instead of the scraping member 212, a wiping member such as a sponge for wiping off the foreign matter k electrostatically attracted to the outer peripheral surface 211 a of the foreign matter removing roller 211 may be provided in the housing member 214. Also in this case, substantially the same effect as that of the scraping member 212 can be obtained.

  Further, the foreign matter removing roller 211 can be driven by a motor M4 that drives the second transport roller pair 234, and is configured to have the same outer peripheral speed (transport speed) as that of the second transport roller pair 234. Is done. Therefore, the foreign matter k adsorbed in the curved conveyance unit Hw is scraped off by the scraping member 212 on the front side (first surface side) of the document conveyance path 41 by the rotation of the foreign matter removal roller 211. Then, the foreign material k is scraped off by the scraping member 212, and the roller surface of the cleaned foreign material removal roller 211 is exposed again in the document conveyance path 41 by rotation, and the foreign material k can be re-adsorbed.

  The foreign matter adsorption effect of the foreign matter removing roller 211 is greater as the distance between the foreign matter removing roller 211 and the original G is closer or in close contact with each other. In the present embodiment, the foreign matter removing roller 211 is disposed outside the curved conveying portion Hw of the original conveying path 41 (on the outer diameter side of the radius of curvature r), so that the original G is stably adhered to the foreign matter removing roller 211. And the effect of removing foreign matters can be enhanced.

  According to the configuration that does not have a configuration for pressing the single foreign matter removal roller 211 against one side of the original G as in the present embodiment, for example, a roller pair that sandwiches and conveys the original G is used for foreign matter removal, the following problems occur: There is. That is, the foreign matter that could not be removed by the scraping member moves to the roller on the opposite side of the foreign matter removing roller while the document is not being conveyed, and the amount of foreign matter on the document surface on the opposite roller side increases. There is a fear. However, according to the present embodiment, since the foreign matter removing roller 211 is composed of a single roller, the foreign matter is not transferred to the opposite roller, and the foreign matter can be easily arranged in a compact configuration at a required place. A removal function can be incorporated.

  Further, since it is only necessary to rotate the single foreign substance removal roller 211 in one direction, it is possible to reduce control restrictions, simplify the configuration, and avoid an increase in size and cost of the apparatus.

<Second Embodiment>
Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment is the same as the first embodiment except that the arrangement of the collection unit is different. The same members as those in the first embodiment are denoted by the same reference numerals, and the same configuration and function are used. The description is omitted. FIG. 7 is a cross-sectional view showing details of the recovery unit according to the present embodiment.

  This embodiment has a configuration corresponding to a case where the foreign matter removing roller 211 cannot be arranged on the curved conveyance unit Hw (FIG. 4) due to design reasons, for example, only on a linear conveyance path. That is, in this case, in FIG. 4, the foreign material removal roller 211 and the recovery unit 202 indicated by the alternate long and short dash line can be arranged on the linear conveyance unit Ht upstream of the second conveyance roller pair 234.

  That is, as shown in FIG. 7, the single foreign matter removing roller (rotating body) 211 in the present embodiment is one from the one side (the lower side in FIG. 7) in the linear conveyance portion Ht of the document conveyance path 41. Rotate by driving the part. The collection unit 202 of the present embodiment constitutes a collection unit that collects the foreign matter k attached to the outer peripheral surface 211a of the foreign matter removal roller 211 by contacting the original G that is transported through the original transport path 41.

  The linear transport unit Ht includes a first transport guide (one transport guide) 315 and a second transport guide (the other transport guide) 316 that face each other with a gap therebetween. The foreign matter removing roller 211 allows a part of the outer peripheral surface 211a to enter from a notch 315a provided at a predetermined position of the first conveyance guide 315. As in the first embodiment, the foreign matter removing roller 211 is provided so as to cover substantially the entire region including the dimension in the width direction of the specification document.

  The second conveyance guide 316 has a shape that allows the document G conveyed on the document conveyance path 41 to come into contact with the foreign matter removing roller 211 while increasing the rigidity. That is, the second transport guide 316 in the linear transport unit Ht has convex portions 316a and 316b. The convex portions 316a and 316b are in the direction of document transport (arrows) within the range of the transported document length (sheet length) of the portion (concave portion 316c) facing the outer peripheral surface 211a entering from the first transport guide 315. Projecting into the document transport path 41 from the upstream side and the downstream side in the direction E). In this case, since the conveyed document G is always pressed against the outer peripheral surface 211a of the foreign matter removal roller 211 by the convex portions 316a and 316b of the second transport guide 316, the foreign matter k can be stably adsorbed. become.

  The notch 315a is extended so as to be slightly longer than the axial length of the foreign matter removing roller 211 in the front-back direction of FIG. The foreign matter removing roller 211 is arranged over substantially the entire region including the dimension in the width direction of the specification document so that the foreign matter adhering to almost the entire region of the conveyed document G can be effectively collected. Composed. Also in this embodiment, the foreign matter removing roller 211 is rotated in the same direction and at the same speed together with the second conveying roller pair 234 by driving the motor M4. The foreign matter removing roller 211 is rotated in a direction (counterclockwise direction: direction of arrow F) according to the flow of the document G conveyed in the document conveyance direction (direction of arrow E).

  The recovery unit 202 includes a scraping member 312 as a contact member that contacts the outer peripheral surface 211a of the foreign matter removing roller 211, and a storage member 314 that stores the foreign matter k that is peeled off from the outer peripheral surface 211a by the contact of the scraping member 312. Have. The housing member 314 is provided so as to extend in the axial direction of the foreign matter removing roller 211, and is supported by the apparatus main body of the ADF 220 or the apparatus main body 10 of the image forming apparatus 100.

  The scraping member 312 is also configured as a charging member that makes contact (sliding contact) with the outer peripheral surface 211a of the foreign matter removal roller 211 and frictionally charges the foreign matter removal roller 211, and scrapes the foreign matter k electrostatically attracted to the outer peripheral surface 211a. Remove.

  The scraping member 312 is formed in a plate shape such as a rubber material that is long in the front-back direction of FIG. 7 and extends in the axial direction of the foreign matter removing roller 211. The accommodating member 314 is also configured to have an equivalent length dimension so as to correspond to the scraping member 312 extending in the axial direction of the foreign matter removing roller 211. Thereby, the scraping member 312 is brought into contact with the entire area in the axial direction (main scanning direction) of the foreign matter removing roller 211, and the foreign matter k adsorbed on the outer peripheral surface 211a of the foreign matter removing roller 211 can be efficiently collected.

  The housing member 314 includes an extending portion 314a extending from the wall portion 314e toward the foreign matter removing roller 211, a wall portion 314b projecting upward from the opposite side of the wall portion 314e, and between the extending portion 314a and the wall portion 314b. And a notch 314c provided on the surface. The housing member 314 is positioned and fixed in a state where the lower side of the foreign matter removing roller 211 enters the notch 314c. In this state, the rear end of the scraping member 312 is fixed to the front end of the extending portion 314 a, and the front end is in contact with the foreign matter removing roller 211. The foreign matter removing roller 211 is positioned in a direction against the rotation of the foreign matter removing roller 211 rotating in the counterclockwise direction (the direction of the arrow F) in FIG. 7, and is fixed to the extending portion 314a.

  The storage member 314 is configured to receive and store the foreign matter k scraped by the scraping member 312 at the bottom portion 314 d below the scraping member 312. The housing member 314 may have any shape and configuration that collects the foreign matter k adsorbed on the outer peripheral surface 211a of the foreign matter removing roller 211 and does not drop the collected foreign matter k.

  According to the above embodiment, the foreign matter removing roller 211 and the second conveyance guide 316 on the opposite side have the upstream and downstream convex portions 316a and 316b on the inner surface, and the foreign matter is removed in the concave portion 316c therebetween. The foreign material k is adsorbed from the original G in the form of pressing the roller 211. For this reason, the foreign material k can be stably adsorbed from the back side (second surface side) of the document G in a state in which the front and rear ends in the document transport direction are supported by the convex portions 316b and 316a and the rigidity (rigidity) is increased. It becomes possible.

  In the present embodiment, an example in which the configuration for removing foreign matter is applied to the image reading apparatus 200 has been described. However, the present invention is not limited to this as long as it is used for removing foreign matter from conveyed sheets. It is also possible to apply to the sheet conveying apparatus.

  That is, the collection units 201 and 202 and the foreign matter removal roller 211 described above can be arranged as follows in addition to the curved conveyance unit Hw and the linear conveyance unit Ht of the ADF 220 described with reference to FIG. For example, it can also be arranged in the curved conveying section Hw or the linear conveying section Ht in the sheet conveying path 36 of the sheet conveying apparatus 34 in the apparatus main body 10 shown in FIG. In this case, the linear transport unit Ht is provided in a linear part that feeds the sheet S from the sheet feeding unit 30 and the sheet S from the manual feed tray 35 shown in FIG. 1 to the registration roller pair 11. Further, the curved conveyance unit Hw is provided at a curved portion upstream of the linear conveyance unit Ht in the sheet conveyance direction.

  In this case, the collection units 201 and 202 collect the foreign material k attached from the sheet S to the outer peripheral surface 211a of the foreign material removal roller 211 by contacting the sheet S conveyed through the curved conveyance unit Hw and the linear conveyance unit Ht. can do. Even with such a configuration, it is possible to obtain substantially the same effect as described above.

  The first and second embodiments have been described using the electrophotographic image forming apparatus 100. Instead, for example, an ink liquid is ejected from a nozzle to form an image on a sheet. It can also be used in an inkjet image forming apparatus.

  20... Image forming unit (image forming means) / 34... Sheet conveying device / 36... Sheet conveying path / 41 .. document conveying path (sheet conveying path) / 100. Collection unit (collection means) / 205 ... first conveyance guide (one conveyance guide) / 205a ... notched portion / 206 ... second conveyance guide (other conveyance guide) / 208 ... original conveyance device (sheet conveyance device) / 211 ... Foreign matter removing roller (rotary member) / 211a ... outer peripheral surface / 212, 312 ... scraping member (contact member) / 214, 314 ... housing member / 253 ... first scanner unit (image reading means) / 315 ... first Conveying guide (one conveying guide) / 315a ... Notch / 316 ... Second conveying guide (the other conveying guide) / 316a, 316b ... Convex part / 316c ... Concave part / G ... Original ( Over DOO) / Ht ... straight transporting unit / Hw ... curved conveying section / k ... foreign objects / r ... curvature radius / S ... Sheet

Claims (8)

A sheet conveyance path having a pair of conveyance guides facing each other at an interval, and capable of conveying a sheet between the pair of conveyance guides;
A rotating body that rotates by allowing a part of the outer peripheral surface to enter the sheet conveying path from one side of the pair of conveying guides;
E Bei and a recovery means for recovering foreign matter adhered from the sheet on the outer peripheral surface in contact with the sheet conveyed to the sheet conveying path,
The other of the pair of transport guides is formed from the upstream side and the downstream side in the sheet transport direction within the range of the transported sheet length of the portion facing the outer peripheral surface entering from the one transport guide. A convex portion protruding into the sheet conveyance path;
The sheet conveyed through the sheet conveying path is pressed against the rotating body by the convex portion.
A sheet conveying apparatus. The rotating body and said recovery means, Ru are arranged corresponding to the linear transport section in the sheet conveying path,
The sheet conveying apparatus according to claim 1 . The recovery means includes
A contact member that contacts the outer peripheral surface of the rotating body;
A storage member that stores foreign matter that is peeled off from the outer peripheral surface by the contact of the contact member;
Sheet conveying apparatus according to claim 1 or 2, characterized in that. The contact member is slidably contacted with the outer peripheral surface to frictionally charge the rotating body and remove foreign matter electrostatically attracted to the outer peripheral surface.
The sheet conveying apparatus according to claim 3 . The rotating body is constituted by a resin member.
Sheet conveying device according to any one of claims 1 to 4, characterized in that. The rotating body is a roller that can face the entire region in the width direction orthogonal to the conveyance direction of the sheet conveyed through the sheet conveyance path.
Sheet conveying apparatus according to any one of claims 1 to 5, characterized in that. A sheet conveying apparatus according to any one of claims 1 to 6 ,
Image reading means for reading image information from a sheet that is a document conveyed by the sheet conveying device,
An image reading apparatus. An image reading apparatus according to claim 7 ;
Image forming means for forming an image on a sheet based on the image information read by the image reading means,
An image forming apparatus.

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