JP4660509B2 - Paper transport device and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet conveying device and an image forming apparatus, and more particularly to a device that prevents noise accompanying sheet conveyance from leaking outside the apparatus.

  Conventionally, by mounting a paper transport device that transports paper through a transport path, the paper is automatically supplied to the processing position of the apparatus main body. For example, it is mounted on an image forming apparatus that forms an image such as a character on a transport sheet.

  The paper conveyance device mounted on this type of image forming apparatus is configured to stack paper for image formation in a paper cassette and continuously convey the paper cassette. It is set to be detachable so that it can be replenished (see, for example, Patent Documents 1 to 3).

JP-A-5-740 JP-A-8-53253 JP 2002-370847 A

  However, in such a conventional paper transport apparatus, the paper cassette is often arranged at the lower part of the main body of the apparatus, and in this case, the paper is loaded so that the paper is drawn out from the paper cassette and passed. The conveyance path is defined in a vertical shape. A gap is formed between the sheet cassette and the apparatus main body so that the sheet cassette is slid to the front side and pulled out to communicate with the sheet conveyance path and the outside of the apparatus.

  When the paper width direction of the paper transport path is arranged in parallel with the front surface of the apparatus main body, the paper transport path is positioned in the vicinity of the operation surface side of the apparatus, and the gap between the paper cassette and the apparatus main body. In some cases, noise accompanying the conveyance of the paper leaks and becomes annoying.

  In particular, when the exterior cover arranged at the upper part of the paper cassette is configured to be rotatable forward, it is necessary to secure a wide gap between the upper part of the paper cassette and the outer cover to be rotated. , The noise accompanying the conveyance of paper is easy to leak.

  Accordingly, the present invention provides a paper transport apparatus and an image forming apparatus that can be used comfortably by closing a gap between the paper cassette and the apparatus main body, thereby shielding noise associated with paper transport. With the goal.

A first invention of a paper transport device that solves the above problems includes a transport means for transporting paper to a processing position of the apparatus main body, a paper cassette that can be attached to and detached from the apparatus main body for stacking paper transported by the transport means, A paper transport apparatus comprising a transport path for passing a sheet transported from a sheet cassette to a processing position of the apparatus main body, and an exterior cover that defines or opens the transport path ,
Wherein with the paper cassette is formed on the conveyance path vertical sheet is disposed in the lower the apparatus main body, by the said transport path exterior cover is disposed on the front side of the apparatus body, said device between the outer cover and can be drawn out the paper cassette on the front side of the main body, a gap that communicates the way the transport path to the outside of the apparatus is defined,
The outer cover rotates around a rotation fulcrum near the upper side of the gap,
It is characterized in further comprising a shielding member for closing the gap in the outer cover.

In the present invention, the gap between the sheet cassette communicating with the vertical conveyance path disposed on the front side and the exterior cover is closed by the shielding material. Therefore, the noise accompanying the conveyance of the sheet passing through the conveyance path does not leak as it is from the gap, and the sheet can be conveyed gently to the processing position of the apparatus main body.

A second invention of a paper conveying device that solves the above-mentioned problems is characterized in that, in addition to the specific matters of the first invention, the exterior cover rotates around a rotation fulcrum near the upper side of the gap. To do.

  In the present invention, since the outer cover at the top of the paper cassette rotates, even when a large gap is defined, the gap is blocked by the shielding material. Therefore, even in the case of a structure in which the noise accompanying the conveyance of the paper is likely to leak, it is possible to reliably close the gap and prevent the noise from leaking, and it is possible to quietly convey the paper to the processing position of the apparatus main body. it can.

A third invention of the sheet conveying apparatus to solve the above problems, in addition to the first or second specific matters of the invention, the shielding member is secured to the lower surface of the outer cover defining said gap, said The outer cover is slidably contacted with a member that defines a gap on the paper cassette side by rotation of the outer cover .

In this invention, the shielding material that closes the gap between the paper cassette and the exterior cover is fixed to the lower surface of the exterior cover on the apparatus main body side. Therefore, when the paper cassette is pulled out from the apparatus main body, the shielding material is not exposed to an easily viewable position, and the aesthetic appearance of the apparatus is not impaired. Even if the opening / closing (turning) of the exterior cover is repeated, the noise associated with the conveyance of the recording paper does not become annoying and the image recording process can be comfortably performed on the recording paper.

According to a fourth aspect of the paper conveying apparatus that solves the above problem, in addition to the specific matters of the third aspect, the shielding material covers an elastic material that is in close contact with the lower surface of the exterior cover on the apparatus main body side, and covers the elastic material. The sheet material is excellent in sliding property, and the sheet material is fixed to at least the outer surface side of the apparatus main body on the lower surface of the exterior cover to hold the elastic material and to form a gap on the paper cassette side set in the apparatus main body. It contacts the upper surface of the member to be defined.

In this invention, the sheet material attached to the lower surface of the exterior cover on the apparatus main body side is pressed against the upper surface of the member on the paper cassette side by the elastic material, so that the gap can be reliably shielded. When the sheet cassette is pulled out, the shielding material comes into sliding contact with the upper surface of the member on the sheet cassette side, and when the sheet cassette is set , the upper surface of the member on the sheet cassette side from the fixing portion side of the sheet material on the outer surface of the apparatus main body. It returns to the state where it is slidably contacted and shielded (contacted). Therefore, by repeatedly attaching and detaching the paper cassette, the shielding material will not be worn and will not function, and the noise accompanying the conveyance of the paper can be shielded for a long period of time.

Invention of the image forming apparatus to solve the above-mentioned problems, which is provided with a paper conveying apparatus of a fourth one of the invention from the first, to convey the paper pull the paper in the paper cassette to the forming position of the image It is a feature.

According to the present invention, even in an image forming apparatus in which a transport path for transporting paper from the paper cassette to the image forming position is arranged vertically on the front side of the apparatus, the effects of the above invention can be obtained. Therefore, the gap between the paper cassette communicating with the vertical conveyance path and the outer cover is closed with a shielding material, and noise accompanying the conveyance of the paper is not leaked from the gap as it is, so that an image can be formed gently. The sheet can be conveyed to the position.

  Hereinafter, the present invention will be described with reference to the drawings. 1 to 3 are views showing an embodiment of an image forming apparatus equipped with a paper conveying apparatus according to the present invention.

  In FIG. 1, an image forming apparatus 100 is used by connecting to an external device such as a personal computer that creates and outputs an image such as a character. The image forming apparatus 100 is provided on one side of a recording sheet (conveying sheet). The image recording apparatus 10 for recording and forming image data such as characters received on the side or both sides by the electrophotographic method, and transporting a plurality of stacked recording sheets (cut sheets) to the image recording apparatus 10 and recording images And a paper transport device 20 for carrying the formed recording paper out of the apparatus and stacking it.

  The image recording device 10 forms a electrostatic latent image on the surface by irradiating and scanning the laser beam scanning device 11 that scans the laser beam based on the image data and the laser beam from the laser scanning device 11. And a developing unit for each color for developing the electrostatic latent image on the photosensitive drum 12 with yellow (Y), cyan (C), magenta (M), and black (K) toners. The developing rotary unit 13 accommodated, the waste toner tank 14 for collecting and storing the toner remaining on the photosensitive drum 12, and the toner image formed on the photosensitive drum 12 are received and transferred onto the recording paper. A recording belt that forms a recordable toner image (monochrome image or color image) and a recording belt that is nipped and conveyed so as to be sandwiched between the transfer belt 15 and the transfer belt 15 The transfer roller 16 for transferring the toner image to the recording roller and the recording paper transferred with the toner image transferred thereto are heated and pressed to fix the toner image and the recording paper is further nipped and conveyed downstream. A pair of rollers 17a and 17b. That is, the transfer belt 15 and the transfer roller 16 constitute a transfer portion, and the fixing roller pairs 17a and 17b constitute a fixing portion. The transfer belt 15, the transfer roller 16 and the fixing roller pairs 17a and 17b together with rollers described later together with a sheet A conveying means in the conveying device 20 is also configured.

  The image recording apparatus 10 records the received image data on one side or both sides of the recording sheet by feeding the recording sheet to the recording formation position of the image by the transfer belt 15 and the transfer roller 16. Form.

  The sheet conveying device 20 sets a plurality of recording sheets for recording and forming an image and separates and feeds the recording sheets one by one to a conveying path f (f1 to f7 described later), and the recording that has been fed. A transport unit 22 that transports the paper through the transport path f to the image recording apparatus 10; a paper discharge unit 23 that discharges recording paper on which an image has been recorded by the image recording apparatus 10; A reversing unit 24 that passes through a re-conveying path r (r1, r2 to be described later) for reversing and re-conveying a recording sheet on which an image has been formed, and re-passes through a conveying path f on the upstream side of the image recording apparatus 10. It has.

  The feeding unit 21 is in pressure contact with a sheet cassette 25 that includes an elevating plate 25a for stacking and setting a plurality of recording sheets and is detachably attached to the lower part of the apparatus main body, and a recording sheet bundle raised by the elevating plate 25a. And a pickup roller 26 that pulls out the recording paper by rotating it, and a separation that restricts the recording paper from being slid in contact with the recording paper that has been pulled out while pressing the pickup roller 26 at a constant pressure. And a pad 27.

  In the feeding unit 21, a pickup roller 26 is pressed against the uppermost recording paper drawn from the paper cassette 25, while a lower recording paper and a separation pad 27 slide on the lower recording paper. By making contact, it is possible to draw out only the uppermost recording sheet with which the pip-up roller 26 is in pressure contact with each other by utilizing the difference in friction coefficient between the pickup roller 26, the separation pad 27 and the recording sheet. Then, the recording sheet can be separated and fed to the conveyance path f of the conveyance unit 22 and fed downstream.

  In addition to the transfer belt 15, the transfer roller 16, and the fixing roller pair 17 a and 17 b of the image recording apparatus 10, the transport unit 22 receives a recording sheet fed by the pickup roller 26 of the feeding unit 21 into the transport path f. Further, the pair of relay rollers 28a and 28b that are nipped and conveyed downstream, and the pair of relay rollers 28a and 28b receives the recording paper conveyed in the conveyance path f, and the image is transferred by the transfer belt 15 and the transfer roller 16 of the image recording apparatus 10. A pair of registration rollers 29a and 29b that are nipped and conveyed to the recording formation position and a recording sheet on which an image has been formed in the conveyance path f sent from the fixing roller pair 17a and 17b of the image recording apparatus 10 are received and nipped and conveyed further downstream. And a pair of relay rollers 30a and 30b.

  The conveying unit 22 is configured to transfer the recording sheet sent from the feeding unit 21 and pass through the conveying path f so that the registration roller pair 29 a and 29 b are synchronized with the driving of the image recording apparatus 10. The image is nipped and conveyed to the image recording position by the transfer roller 16, and thereafter, nipped and conveyed by way of the fixing position by the fixing roller pair 17a and 17b. At this time, the registration roller pair 29a, 29b is fed by a recording sheet (an unused recording sheet from the sheet cassette 25 or the image recording apparatus 10) sandwiched and conveyed by the relay roller pair 28a, 28b or a later-described relay roller pair 35a, 35b. When the image recording apparatus 10 receives the recording sheet having an image formed on one side and conveys it to the recording formation position of the image by the image recording apparatus 10, after the leading edge of the recording sheet is abutted against the nip portion in a paused state, The rotational driving is resumed and the recording paper is nipped and conveyed. As a result, the recording paper has an appropriate posture in which the skew is corrected so that the leading ends thereof are parallel to the roller axes of the registration roller pairs 29a and 29b, and one side is set as an image recording formation surface, and the image by the image recording apparatus 10 is used. Are supplied to the recording forming position.

  The paper discharge unit 23 includes a pair of paper discharge rollers 31a and 31b on which the pair of relay rollers 30a and 30b of the transport unit 22 receives the recording paper that is transported in the transport path f, and is transported and stacked on the paper discharge table 23a. The paper discharge unit 23 receives the recording paper on which the image has been formed sent from the transport unit 22 and discharges the recording paper to the outside of the apparatus.

  The pair of paper discharge rollers 31a and 31b of the paper discharge unit 23 rotate in the reverse direction according to the recording formation mode of the image to be processed, in addition to the rotation drive (paper discharge function) for discharging the recording paper onto the paper discharge table 23a. It is configured to be drivable, and when the duplex mode for recording and forming images on both sides of the recording paper is instructed, it is temporarily stopped at the position where the trailing edge of the recording paper carried onto the paper discharge table 23a is sandwiched. By later driving in reverse, the recording paper on which the image has been formed on one side is sent out to the re-conveyance path r. That is, the paper discharge roller pair 31 a and 31 b is also used as the reversing unit 24.

  In addition to the paper discharge roller pair 31a and 31b of the paper discharge unit 23, the reversing unit 24 is disposed between the paper discharge roller pair 31a and 31b and the relay roller pair 30a and 30b of the transport unit 22 and is a recording sheet. The switching guide 32 that switches the path through which the sheet can pass to either the conveyance path f or the re-conveyance path r, and the discharge roller pair 31a, 31b receive the recording paper that passes through the re-conveyance path r and further downstream. And a pair of relay rollers 30a, 30c, 34a, 34b for nipping and transporting, and a pair of relay rollers 34a, 34b receiving the recording paper transported in the re-transport path r and upstream of the registration roller pairs 29a, 29b of the transport unit 22 And a pair of relay rollers 35a and 35b that are fed into the transport path f. The switching guide 32 is designed to open the re-conveying path r side as a recording paper passing path by its own weight, and the relay roller pair 30a, 30b is nipped and conveyed via the fixing roller pair 17a, 17b. The recording paper to be transferred is delivered to the paper discharge roller pair 31a, 31b of the paper discharge unit 23 so as to push up the switching guide 32 thereof. The relay roller pair 30a, 30b and the relay roller pair 30a, 30c are configured by pressing the relay roller 30a on the driving side in common with the relay rollers 30b, 30c on the driven side. While the recording paper in the conveyance path f is nipped and conveyed, the relay roller pairs 30a and 30c nipping and conveying the recording paper in the re-conveyance path r.

  The reversing unit 24 switches the recording paper that has been nipped and conveyed by the conveying roller pair 30a and 30b to the discharge roller pair 31a and 31b of the paper discharging unit 23 by pushing up the switching guide 32. When the duplex mode is instructed after the guide 32 is removed from the lower surface of the guide 32, the paper discharge roller pair 31a, 31b of the paper discharge unit 23 is driven in reverse. At this time, since the switching guide 32 opens the re-conveying path r as a recording paper passing path by its own weight, the paper discharge roller pair 31a, 31b re-conveys the recording paper on which an image is formed on one side. By passing the paper through the path r and nipping and transporting it between the relay roller pairs 30a, 30c, 34a, 34b, 35a, and 35b, the recording paper with the front and back reversed is passed again through the transport path f and registered in the transport unit 22 Delivered to the roller pair 29a, 29b. As a result, the recording sheet is transported and supplied again to the image recording position by the image recording apparatus 10 with the other side (one side where no image is recorded) as the image recording surface.

  The sheet conveying apparatus 20 is attached to the cassette cover 41 at the lower part of the apparatus main body and the upper part of the cassette cover 41 as an exterior cover on the front side (left side in the figure) for operating the apparatus main body (image forming apparatus 100). A front cover 42 and an upper surface cover 43 attached to the upper surface of the apparatus main body continuous with the front cover 42 are attached to be openable and closable, and the front cover 42 is associated with a positioning lock mechanism 44 disposed on the upper part. The upper cover 43 is opened and closed while being positioned by the combination / release. Inside these covers 41 to 43 are stored various guide members that define transport paths f1 to f7 for transporting the recording paper, re-transport paths r1 and r2, and the like to open and close the covers 41 to 43. It is constructed to open and close (open / define) the transport paths f1 to f7 and the re-transport paths r1 and r2 by rotating the guide member in conjunction with each other.

  The cassette cover 41 is formed with a pull-out hook 41 a to be gripped so that the paper cassette 25 can be slid out and pulled out, and is attached to the front surface of the paper cassette 25. In this cassette cover 41, a guide member 45 is attached to the apparatus main body side so as to be positioned above the paper cassette 25. When the upper portion of the cassette cover 41 and the lower portion of the guide member 45 face each other, The pickup roller 26 defines a transport path f1 through which the recording paper is drawn upward from the paper cassette 25 to pass and transport. A pickup roller 26 is rotatably supported on the guide member 45 (device main body) side, and a relay roller 28a on the driving side is axially supported, and is separated on the cassette cover 41 (paper cassette 25) side. A pad 27 is attached and a relay roller 28b on the driven side is pivotally supported. Thus, when the cassette cover 41 is opened, the paper cassette 25 is pulled out from the lower part of the apparatus main body, the conveyance path f1 is opened, the separation pad 27 from the pickup roller 26, and the drive relay roller 28a. The driven relay roller 28b can be separated, and when a recording sheet being conveyed is pinched, the recording sheet can be collected and removed as it is. The transport path f1 is also continuously formed between the paper cassette 25 and the lower part of the cassette cover 41, so that the paper cassettes 25 can be stacked in multiple stages.

  Here, the relay roller pair 28a and 28b are positioned via a plurality of members such as the paper cassette 25 and its slide mechanism, and are configured to be in pressure contact with each other. Unlike the other roller pairs, the pressure contact force is a mechanism that greatly affects machining accuracy and assembly accuracy by interposing a plurality of positioning members between the rollers 28a and 28b. Therefore, the relay roller pair 28a and 28b are divided into short roller shapes and are supported by separate roller shafts, and the driven-side relay roller 28b is pressed against the driving-side relay roller 28a. The compression springs are also provided separately. As the compression spring, one having a small spring constant and a long stroke length is selected, and is designed to form a mutual pressure contact state by being largely displaced during the pressure contact. For this reason, the relay roller pairs 28a and 28b are designed so that the fluctuation of the elastic force due to the displacement of the compression spring is reduced, and stable pressure contact is achieved even when the displacement amount of the compression spring varies due to the presence of a plurality of positioning members. Force can be obtained, and the recording paper can be pinched and conveyed with high accuracy and delivered to the downstream side.

  The front cover 42 is supported so as to be rotatable in a direction away from the apparatus main body with a position close to the upper part of the cassette cover 41 (lower part of the apparatus main body) as a rotation fulcrum 42a. A conveyance path through which the recording sheet fed by the relay roller pair 28a, 28b is nipped and conveyed from the conveyance path f1, with the guide surface 42b on the inner side of the main body facing the upper portion of the guide member 45, like the cassette cover 41 f2 is defined. Thereby, the front cover 42 can open the conveyance path f2 by rotating around the rotation fulcrum 42a. When the recording sheet from the sheet cassette 25 is being viewed, the cassette cover 41 is opened. The recording sheet can be easily collected and removed by slightly pulling out the ink and releasing the nip pressure between the relay roller pair 28a, 28b.

  Further, in the front cover 42, the conveyance paths (inner sheet conveyance paths) f <b> 1 to f <b> 6 that are arranged inside the apparatus main body and substantially parallel to the front cover 42, and the outside arranged in the apparatus main body and the front thereof are arranged. A re-transport path (outer paper transport path) r2 substantially parallel to the cover 42 is defined by the guide members 46 to 52. That is, the paper transport device 20 is constructed in a vertical type so that the recording paper is passed through the transport paths f1 to f6 and the re-transport path r2 and nipped and transported in the vertical direction.

  The guide member 46 is attached to the inside of the apparatus main body so as to be continuous with the upper side of the guide member 45, and guide members 47 and 48 are attached to the outside of the apparatus main body so as to face the guide member 46. Yes. The guide member 46 pivotally supports a driven registration roller 29b. The driving registration roller 29a that is in pressure contact with the driven registration roller 29b is attached to the apparatus main body, and is positioned above and below the driving registration roller 29a. Guide members 47 and 48 are arranged. That is, between the guide members 46 and 47 and the guide members 46 and 48, conveyance paths f3 and f4 that are continuous to the conveyance path f2 are defined, and the pair of relay rollers 28a and 28b are nipped and conveyed to form a resist. The recording paper delivered to the roller pair 29a, 29b is passed from the conveyance path f2 to the conveyance paths f3, f4.

  Similarly to the front cover 42, the guide member 48 is supported so as to be rotatable in a direction away from the apparatus main body, with the lower side close to the drive registration roller 29a as a rotation fulcrum 48a. The guide member 48 pivotally supports the transfer roller 16, which is pressed against the transfer belt 15, at an intermediate portion (upper side of the guide member 46) inside the apparatus main body, and the lower side of the transfer roller 16 is guided by the guide member 46. The conveyance path f4 is defined so as to face each other. Further, the guide member 48 defines a one-side open conveyance path f5 that guides the recording sheet to the downstream fixing roller pair 17a and 17b on the upper side of the intermediate portion (transfer roller 16) on the inner side of the apparatus main body. The transfer belt 15 and the transfer roller 16 are in contact with the other side of the recording sheet before fixing, on which the image is transferred to one side, and are guided to the fixing roller pair 17a and 17b so as not to deteriorate the image quality. . As a result, the guide member 48 can open the transport paths f4 and f5 by rotating about the rotation fulcrum 48a, and the recording roller is clamped by separating the transfer roller 16 that is in pressure contact with the transfer belt 15. The nip pressure is released, and the recording paper can be easily collected and removed.

  The guide members 49 to 51 are fixed to the apparatus main body, and the guide member 49 continuously defines the transport path f5 when the front cover 42 is closed, while the guide members 50 and 51 are defined. Defines a conveying path f6 between the fixing roller pair 17a, 17b and the relay roller pair 30a, 30b. As a result, the recording sheet on which the image has been transferred can be fixed via the fixing roller pair 17a, 17b, and then transferred to the relay roller pair 30a, 30b and further conveyed downstream.

  The guide member 52 is rotatably supported by the front cover 42 with the side close to the upper portion of the guide surface 42b of the front cover 42 as a rotation fulcrum 52a, and between the guide member 48 and the front cover 42 main body. At the same time, it rotates in the direction away from the apparatus main body together with the front cover 42, and can also rotate in the direction away from the front cover 42. The guide member 52 faces the inner surface of the front cover 42 so as to define a re-conveying path r2 for the recording paper nipped and conveyed by the relay roller pairs 34a, 34b, 35a, 35b. Driving relay rollers 34a and 35a are pivotally supported on the side, and driven relay rollers 34b and 35b are pivotally supported on the front cover 42 side.

  In addition, a biasing mechanism 61 is attached to the guide member 52 at a position facing the guide member 48, and the biasing mechanism 61 biases the guide member 48 in the extending direction, and the guide member 48. And the transfer roller 16 is pressed against the transfer belt 15.

Further, a rotation lever 63 is rotatably attached to the upper portion of the guide member 52, and this rotation lever 63 biases the torsion spring 62 to rotate in the direction of the front cover 42. . Therefore, when the front cover 42 is opened, the guide member 52 is popped up so as to be separated from the inner surface of the front cover 42 by the rotation of the rotation lever 63. As a result, the guide member 52 can be popped up by the turning lever 63 in a direction away from the inner surface of the front cover 42 with the turning of the front cover 42, and the re-conveying path r2 can be expanded and opened. The nip pressures of the relay roller pairs 34a, 34b, 35a, and 35b are released, and the recording paper can be easily collected and removed. Further, since the guide member 52 can be manually rotated so as to be separated from the inner surface of the front cover 42, it is possible to more easily collect and remove the recording sheet being conveyed.
At this time, as the guide member 52 rotates (the front cover 42 rotates), the guide member 48 is released from the biasing mechanism 61 and rotates around the rotation fulcrum 48a. The recording paper can be easily collected and removed from the transport paths f4 and f5.

  Here, the guide member 52 may form a plurality of opening holes on the rotation tip side opposite to the rotation fulcrum 52a, and the opening holes are located within the conveyance range of the recording paper in the re-conveyance path r2. To be formed. In this case, the recording paper staying in the reconveying path r2 can be seen through the opening hole of the guide member 52, and the guide member 52 pops up from the front cover 42 and looks through the reconveying path r2. In this way, it is not necessary to confirm the presence or absence of the recording paper P.

  The upper surface cover 43 is supported so as to be rotatable in a direction in which the front side is separated from the upper portion of the front cover 42 with the inner side of the upper surface of the apparatus body as a rotation fulcrum 43a. The guide members 53 and 54 include a conveyance path f7 through which the recording paper from the conveyance paths f1 to f6 passes and a re-conveyance path r1 through which the recording paper to be reversely conveyed again from the conveyance path f7 to the image recording position. It is defined by.

  The guide member 53 is attached to the apparatus main body so as to be continuous with the guide member 50 that defines the conveyance path f6 on the downstream side of the fixing roller 17a, and faces the inner surface of the upper surface cover 43, thereby defining the conveyance path f7. The guide member 53 is supported by a driven relay roller 30b and a paper discharge roller 31b. The guide member 54 is attached to the upper surface cover 43 side so as to be continuous with the upper portion of the guide member 52 that defines the re-conveyance path r2, and defines the re-conveyance path r1 by facing the inner surface of the upper surface cover 43. The drive member relay roller 30a and the paper discharge roller 31a are pivotally supported by the guide member 54, and a driven relay roller 30c that is pressed against the relay roller 30a is also pivotally supported. The guide member 54 is attached so that the switching guide 32 can swing. Thereby, the upper surface cover 43 can open the connection portion of the transport path f7 and the re-transport paths r1 and r2 by rotating about the rotation fulcrum 43a, and the relay roller pair 30a and 30b and the paper discharge roller By releasing the nip pressure between the pair 31a and 31b, the recording paper can be easily collected and removed.

  As described above, the sheet conveying apparatus 20 has the vertical recording sheet conveying paths f1 to f7, r1, and r2 formed in the vicinity of the front side of the image forming apparatus 100, and conveys the recording sheet in the sheet cassette 25. A gap s formed between the cassette cover 41 of the paper cassette 25 and the front cover 42 on the apparatus main body side communicates between the transport paths f1 and f2 to be performed. The gap s is defined so that the lower surface of the front cover 42 and the upper surface of the cassette cover 41 are separated from each other so that the front cover 42 rotates about the rotation fulcrum 42a. ing.

  By the way, in this paper transport apparatus 20, after correcting the skew by abutting the leading ends of the recording papers nipped and transported by the relay roller pairs 28a and 28b of the transport unit 22 against the nip portions of the stopped registration roller pairs 29a and 29b, The registration roller pair 29a and 29b are driven to rotate to start nipping and conveying the recording paper. For this reason, in the transport paths f1 to f3, for example, a contact sound may be generated due to the recording sheet bent in the guide surface 42b of the front cover 42 being pulled and contacting the guide member 46 or the like. The contact sound leaks from a wide gap s communicating with the transport paths f1 and f2 in the vicinity of the operation surface (front surface) of the image forming apparatus 100, and may become annoying noise depending on the installation environment of the image forming apparatus 100. There is.

  For this reason, as shown in FIG. 2, the sheet conveying apparatus 20 has a shielding material 70 attached to the lower surface 42 c of the front cover 42, and the shielding material 70 is in close contact with the lower surface 42 c of the front cover 42. A sponge (elastic material) 71 and a PET (polyethylene terephthalate) sheet 72 attached to the lower surface 42c of the front cover 42 so as to cover and hold the sponge 71 are configured. The PET sheet 72 is affixed to the front surface side of the lower surface 42c of the front cover 42 and fixed in a state where one side is opened, and is pressed (contacted) against the upper surface 41c of the cassette cover 41 by the sponge 71. ing. The PET sheet 72 is adopted because it has good slip and excellent durability against friction due to the characteristics of polyethylene terephthalate, and it goes without saying that it may be replaced with a sheet material made of other materials.

  As a result, the image forming apparatus 100 transports the recording paper to the transport paths f1 to f7 and the like in a state where the gap s between the cassette cover 41 and the front cover 42 is closed by the shielding material 70, and performs image recording and forming processing. Further, the contact sound of the recording paper with the guide member 46 and the like can be absorbed by the sponge 71 having excellent soundproofing characteristics while restricting leakage by the PET sheet 72.

  Since the shielding member 70 is fixed to the lower surface 42c of the front cover 42, as shown in FIG. 3A, the shielding member 70 is exposed to a position that is easy to see even when the paper cassette 25 is pulled out from the lower part of the apparatus main body. Without losing the appearance of the device.

  Further, when the paper cassette 25 is pulled out, the shielding member 70 can slide the PET sheet 72 against the upper surface 41c of the cassette cover 41 so that the paper cassette 25 is set at the lower part of the apparatus main body. On the contrary, it is possible to return to the state in which the PET sheet 72 attached to the lower surface 42c of the front cover 42 is brought into sliding contact with the upper surface 41c of the cassette cover 41 from the inclined surface side so as to be smoothly adhered and shielded. Similarly, when the front cover 42 rotates about the rotation fulcrum 42a, the shielding member 70 is also made of a PET sheet 72 with respect to the upper surface 41c of the cassette cover 41 as shown in FIG. After the slide is rotated, the surface of the PET sheet 72 fixed to the lower surface 42c of the front cover 42 is slidably brought into sliding contact with the upper surface 41c of the cassette cover 41 to return to a state of smooth adhesion and shielding. it can.

  Therefore, even if the image forming apparatus 100 is installed in a quiet environment and the attachment and detachment of the paper cassette 25 is repeated and the front cover 42 is repeatedly opened and closed (rotated), the noise associated with the conveyance of the recording paper The image forming process can be comfortably performed on the recording paper.

  As described above, in the present embodiment, even when the gap s between the cassette cover 41 and the front cover 42 communicates with the conveyance paths f1 to f3 that are vertically defined near the front side of the image forming apparatus 100, By closing the gap s with the shielding material 70, it is possible to prevent noise accompanying the nipping and conveyance of the recording paper in the conveyance paths f1 to f3 from leaking as it is. Further, since the shielding member 70 is fixed to the lower surface 42c of the front cover 42, the appearance of the apparatus is not impaired, and the two-layer structure of the sponge 71 and the PET sheet 72 is used for wear. The durability against it is improved. Therefore, it can be used for a long time in a quiet installation environment, and the recording paper can be gently conveyed to the image recording position to form an image on the recording paper.

  According to the present invention, since the gap between the sheet cassette communicating with the vertical conveyance path disposed on the front surface side and the apparatus main body is closed by the shielding material, noise accompanying the sheet conveyance in the conveyance path is generated. The sheet does not leak from the gap as it is, and the sheet can be gently conveyed to the processing position of the apparatus main body. For example, a comfortable image forming process on the conveyance sheet can be realized.

  By attaching this shielding material to the lower surface of the outer cover of the apparatus main body, it is possible to prevent the appearance of the apparatus from being impaired, and a sheet material having a good slip is fixed to the outer surface of the apparatus main body to cover the elastic material. By adopting the configuration, durability against wear and the like can be improved and comfortable use can be continued.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective side view showing an outline overall configuration of an image forming apparatus equipped with a paper conveying apparatus according to an embodiment of the present invention. It is a figure which shows the principal part structure, (a) is a see-through | perspective side view of the applicable location, (b) is the partially expanded see-through | perspective side view. 4A and 4B are diagrams illustrating a configuration of the main part, in which FIG. 4A is a state diagram illustrating when the paper cassette is pulled out, and FIG. 4B is a state diagram illustrating when the apparatus main body is rotated.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Image recording device, 11 ... Laser beam scanning device, 12 ... Photoconductor drum, 13 ... Development rotary unit, 14 ... Waste toner tank, 15 ... Transfer belt, 16 ... Transfer roller, 17a, 17b ... Fixing roller, 20 ... Paper transport device, 21 ... feed section, 22 ... transport section, 23 ... paper discharge section, 24 ... reversing section, 25 ... paper cassette, 26 ... pickup roller, 27 ... separation pad, 28a, 28b, 30a-30c, 34a 35b ... Relay roller, 29a, 29b ... Registration roller, 31a, 31b ... Paper discharge roller, 32 ... Switching guide, 41 ... Cassette cover, 42 ... Front cover, 43 ... Top cover, 44 ... Lock mechanism, 46-54 ... Guide member 61 ... Biasing mechanism 70 ... Shielding material 71 ... Sponge 72 ... PET sheet 100 ... Image forming apparatus f1-f7 ... Transport Route, r1, r2 ... re-transport route.

Claims (3)

Conveying means for conveying paper to a processing position of the apparatus main body, a paper cassette detachable from the apparatus main body for stacking paper conveyed by the conveying means, and paper conveyed from the inside of the paper cassette to a processing position of the apparatus main body A paper conveyance device comprising a conveyance path for passing paper,
A gap that communicates the middle of the transport path defined between the paper cassette mounted on the apparatus main body and the apparatus main body to the outside of the apparatus main body is one end of one member that defines the gap. A sheet conveying device characterized in that the sheet is fixed and closed by a sheet material pressed by an elastic material. The apparatus main body is provided with an exterior cover that rotates about a rotation fulcrum above the gap, and the elastic material is applied to one member that defines the gap by the rotation of the exterior cover. The sheet conveying device according to claim 1, wherein the sheet material is in close contact and is in sliding contact with the other member defining the gap.   An image forming apparatus comprising the sheet conveying device according to claim 1, wherein the sheet is pulled out of the sheet cassette and conveyed to an image forming position.

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