JP2004361495A - Paper transport device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive paper transport device that positions and locks an outer cover in a simple structure and makes it possible to easily remove a jam of transported paper by associating the removal of jammed paper with the order in which the outer cover is opened and closed, and to provide an image forming apparatus. <P>SOLUTION: The paper transport device includes a paper transport path f, retransport path r, a transfer roller 16 for pinching and transporting the paper, and a front cover 42 and an upper cover 43 that accommodate the above mentioned constituents in the main body of the device. The paper transport device is provided with: a locking mechanism 44 that positions and locks an upper face cover 43 into a specific position in such a manner that, when the upper part of the front cover 42 is moved closer to the side 43b of the upper face cover 43, the press lever 91 of the front cover 42 is inserted into the engaging hole of the side 43b and then pushed down; and an energizing mechanism 61 whose movement is associated with the opening operation of the front cover 42, thereby releasing the nip pressure of the roller 16 and the like pinching the paper between them. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sheet conveying apparatus and an image forming apparatus, and more particularly, to an apparatus in which positioning of an exterior cover that accommodates a sheet conveying path and jam processing are linked.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a paper transport device that transports a paper by passing the paper into a transport path is mounted, so that the paper is automatically supplied to a processing position of the device main body. For example, it is mounted on an image forming apparatus that forms an image such as a character on a transport sheet.
[0003]
Generally, a paper transport device mounted on an image forming apparatus of this type includes various types of means for forming an image on a paper by housing a transport path for transporting and transporting the paper to an image forming position in an outer cover. At the same time, it is protected so that hands are not inadvertently touched.
[0004]
This exterior cover needs to be properly closed and locked, and when two or more members that perform opening and closing operations are provided, an interlock mechanism that detects each position is provided to ensure the Various devices have been devised to close and lock.
[0005]
For example, by providing an interlock mechanism having a locking lever for restricting the closing of the top cover, even if the top cover is to be closed unless the side cover is closed and the locking lever is moved to the unlock position. It has been proposed to make a lock lever impulsive so that it cannot be closed (for example, see Patent Document 1).
[0006]
A switch body is disposed on one of the front cover and the upper unit, which independently opens and closes, and an interlock switch is disposed on the other side, which is provided with an interlock switch for turning the switch ON / OFF, so that both are in a closed state. It has been proposed that the closing signal cannot be output unless it becomes (see, for example, Patent Document 2).
[0007]
[Patent Document 1]
JP 2001-152724 A (Patent No. 3341113)
[Patent Document 2]
Japanese Utility Model Laid-Open No. 3-100853 (utility model registration No. 2514666)
[0008]
[Problems to be solved by the invention]
However, in such a conventional interlock of the exterior cover, the mechanism for positioning the two members that perform the opening and closing operations and locking them in the closed state is separately provided, so that the structure is complicated. It became expensive.
[0009]
Further, unless the two members performing the opening / closing operation are operated in a proper order, it is impossible to set the proper closed state (see the above-mentioned document 1), and it is possible to determine whether both of the two members are in the closed state (the above-mentioned document 2). It is possible to perform the jam clearance of the transported paper, but it is necessary to open and close the outer cover and release the nip pressure of the rollers, which is complicated. For this reason, if the operator forgets to release the nip pressure of the roller, there is a risk that the roller may be damaged or the paper may be broken and left in the transport path in an attempt to remove the paper that has stayed forcibly. .
[0010]
In view of the above, the present invention facilitates the jam clearance of the transported paper by easily locking the position of the exterior cover accommodating the paper transport path with a simple configuration and linking the opening / closing order of the exterior cover with the paper jam clearance. It is an object of the present invention to provide an inexpensive paper transport apparatus and an image forming apparatus that can be used.
[0011]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a paper transport apparatus that transports a sheet, a transport path defined in the apparatus body, a roller that sandwiches and transports the sheet in the transport path, A sheet transport device comprising: an exterior cover that accommodates a path and rollers in an apparatus main body; wherein the exterior cover has a set of a first cover and a second cover that open and close with their leading ends close to and separated from each other. A positioning engagement mechanism for positioning and engaging the first cover at a specified position so that the first cover cannot be opened by the second cover when the distal end of the second cover is brought close to the distal end of the first cover; An interlocking mechanism for releasing the nip pressure of a roller for nipping the paper in the transport path in conjunction with the opening operation of the cover.
[0012]
According to the present invention, when closing the exterior cover, the second cover positions the first cover at the specified position only by performing the closing operation of the second cover following the first cover to bring the tips of the two close to each other. As a result, it is possible to engage (lock) so that it cannot be opened. When the exterior cover is opened, the nip pressure of the roller can be released and the positioning engagement of the first cover can be released by simply performing the opening operation of the second cover. Therefore, the first cover and the second cover can be positioned by one mechanism, and the opening operation of the outer cover is performed from the second cover, so that the nip pressure of the rollers for nipping the paper in the transport path is reliably released. can do.
[0013]
According to a second aspect of the present invention which solves the above problems, in addition to the specific features of the first aspect, the interlocking mechanism biases the second cover in an opening direction. is there.
[0014]
According to the present invention, when an opening operation for releasing the closed (locked) state of the second cover is performed, the opening of the second cover is automatically started. Therefore, only by releasing the lock of the second cover, the second cover can be opened simultaneously with the release of the nip pressure of the roller.
[0015]
According to a third aspect of the paper transport apparatus for solving the above-described problems, in addition to the specific features of the first or second aspect, the interlocking mechanism is configured such that an elastic force of an elastic member that generates a nip pressure on the roller is the second cover. The elastic member is compressed and expanded in accordance with the closing / opening operation of the second cover to generate and open the nip pressure of the roller by setting the second cover to be biased in the opening direction. Is what you do.
[0016]
In the present invention, the elastic member is compressed by closing the second cover to generate the nip pressure of the roller, and the second cover is constantly urged in the opening direction. Therefore, the opening of the second cover and the opening of the nip pressure of the roller can be performed in conjunction with each other with a simple and inexpensive configuration.
[0017]
According to a fourth aspect of the present invention which solves the above problems, in addition to the features of any one of the first to third aspects, the first cover and the second cover define at least one side of a transport path. Along with the opening / closing operation for connecting / disconnecting the leading ends of the guides, the guides are moved to define / open a transport path.
[0018]
According to the present invention, the sheet transport path can be opened and closed by opening and closing the first cover and the second cover. Therefore, the transport path can be fully opened by the operation of opening the first cover and the second cover.
[0019]
According to a fifth aspect of the present invention, there is provided an image forming apparatus including the sheet transport device according to any one of the first to fourth aspects, wherein a transport path for transporting a sheet to a position where an image is formed and discharging the sheet is provided. It is characterized by having.
[0020]
According to the present invention, the operation and effect of the present invention can be obtained even in an image forming apparatus having a conveyance path before and after the image forming position. Therefore, it is easy to position and close the outer cover and release the nip pressure for nipping the paper conveyed to the image forming position in conjunction with the opening operation of the outer cover, and at the same time, automatically open the second cover. In addition, the transport path can be fully opened by opening the first cover and the second cover.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 to FIG. 16 are views showing an embodiment of an image forming apparatus equipped with a sheet conveying device according to the present invention.
[0022]
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 has one surface of a recording sheet (conveying sheet). An image recording apparatus 10 for recording and forming image data such as characters received on one side or both sides by electrophotography, and a plurality of stacked recording sheets (cut sheets) are conveyed to the image recording apparatus 10 and images are recorded. And a sheet transport device 20 for carrying out the formed recording sheet outside the apparatus and stacking it.
[0023]
The image recording device 10 includes a laser light scanning device 11 that scans a laser beam based on image data, and a laser beam from the laser scanning device 11 is irradiated and scanned to form an electrostatic latent image on the surface based on the image data. And a developing device 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 stored developing rotary unit 13, a waste toner tank 14 for collecting and storing the toner remaining on the photosensitive drum 12, and receiving the toner image formed on the photosensitive drum 12 and transferring it to recording paper A transfer belt 15 that forms a recordable toner image (monochrome image or color image) and a recording belt that is nipped and conveyed by being pressed (nip) between the transfer belt 15 and the transfer belt 15 A transfer roller 16 for transferring the toner image to the recording paper, and a recording sheet to which the toner image has been transferred and conveyed, is heated and pressed to fix the toner image, and also nips and conveys the recording paper further downstream. And a pair of rollers 17a and 17b. That is, the transfer belt 15 and the transfer roller 16 constitute a transfer section, and the fixing roller pairs 17a and 17b constitute a fixing section. The transfer belt 15, the transfer roller 16 and the fix roller pairs 17a and 17b constitute transport means in the paper transport apparatus 20. Is also configured.
[0024]
The image recording device 10 records the image data received on one side or both sides of the recording paper by being nipped and conveyed to a recording paper forming position by the transfer belt 15 and the transfer roller 16 and supplied. Form.
[0025]
The sheet conveying device 20 sets a plurality of recording sheets on which images are to be formed and feeds the separated sheets one by one to a conveying path f (f1 to f6 described later). A transport unit 22 that transports the paper through the transport path f and transports it to the image recording apparatus 10; a discharge unit 23 that discharges the recording paper on which an image has been recorded by the image recording apparatus 10 to the outside of the apparatus; A reversing unit 24 that passes through a re-conveying path r (r1, r2 described later) for reversing and re-conveying a recording sheet on which an image has been formed and then passes the sheet again to a conveying path f on the upstream side of the image recording apparatus 10. It has.
[0026]
The feeding section 21 is provided with an elevating plate 25a for stacking and setting a plurality of recording sheets, and presses against a sheet cassette 25 detachably attached to a lower portion of the apparatus main body and a recording sheet bundle raised by the elevating plate 25a. A pickup roller 26 that pulls out the recording paper by rotating the recording paper, and a separation that presses the pickup roller 26 at a constant pressure and slidably contacts the drawn out recording paper to restrict the recording paper from being sent downstream. And a pad 27.
[0027]
In the feeding section 21, the pickup roller 26 is pressed against the uppermost recording sheet pulled out from the sheet cassette 25, and the lower recording sheet or the separation pad 27 slides on the lower recording sheet. By contact, the difference between the coefficients of friction of the pickup roller 26, the separation pad 27, and the recording sheet can be utilized to pull out only the uppermost recording sheet pressed by the pip-up roller 26 with its rotation. Then, the single recording sheet can be separated, passed through the transport path f of the transport section 22 and fed downstream.
[0028]
The transport unit 22 receives the recording paper fed by the pickup roller 26 of the feeding unit 21 into the transport path f in addition to the transfer belt 15, the transfer roller 16, and the fixing roller pairs 17a and 17b of the image recording apparatus 10. A pair of relay rollers 28a and 28b pinched and transported further downstream, and the pair of relay rollers 28a and 28b receive the recording paper transported in the transport path f and receive an image by the transfer belt 15 and the transfer roller 16 of the image recording apparatus 10. The pair of registration rollers 29a and 29b that pinch and convey the sheet to the recording forming position, and the image-formed recording sheet in the conveying path f that is sent out from the pair of fixing rollers 17a and 17b of the image recording apparatus 10 are pinched and conveyed further downstream. And a relay roller pair 30a, 30b.
[0029]
The transport unit 22 transfers the recording paper sent from the feed unit 21 and passed through the transport path f to the transfer belt 15 and the transfer belt 15 such that the pair of registration rollers 29 a and 29 b synchronize with the driving of the image recording apparatus 10. The sheet is nipped and conveyed to the image forming position of the image by the transfer roller 16, and thereafter is nipped and conveyed so as to pass through the fixing position by the pair of fixing rollers 17a and 17b. As a result, the recording paper is supplied to the image recording position of the image recording apparatus 10 with one surface as the image recording surface.
[0030]
The paper discharge unit 23 includes paper discharge roller pairs 31a and 31b that receive the recording paper conveyed by the relay roller pairs 30a and 30b of the conveyance unit 22 in the conveyance path f, carry out the paper onto the paper discharge table 23a, and stack the paper. The paper discharge unit 23 receives the recording paper on which the image is recorded and sent from the transport unit 22 and discharges the recording paper outside the apparatus.
[0031]
The paper discharge roller pair 31a, 31b of the paper discharge unit 23 rotates 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. When the double-side mode in which the image is formed on both sides of the recording sheet is instructed, the recording sheet is temporarily stopped at a position where the rear end of the recording sheet carried out onto the sheet discharge table 23a is nipped. By performing reverse rotation later, a recording sheet on which an image has been recorded on one surface side is sent out to the re-transport path r. That is, the sheet discharge roller pair 31a, 31b is also used as the reversing unit 24.
[0032]
The reversing unit 24 is disposed between the pair of discharge rollers 31 a and 31 b of the discharge unit 23 and the pair of relay rollers 30 a and 30 b of the transport unit 22 in addition to the pair of discharge rollers 31 a and 31 b. A switching guide 32 for switching the path through which the sheet can pass to either the transport path f or the re-transport path r, and the pair of discharge rollers 31a and 31b receive the recording sheet passing through the re-transport path r and go further downstream. And a pair of relay rollers 30a, 30c, 34a and 34b for nipping and conveying, and the pair of relay rollers 34a and 34b receive the recording paper conveyed in the re-conveying path r and are located upstream of the pair of registration rollers 29a and 29b of the conveying unit 22. And a pair of relay rollers 35a and 35b for sending out into the transport path f. As shown in FIG. 2A, the switching guide 32 is designed to open the re-conveying path r as a recording paper passing path by its own weight, and passes through the fixing roller pairs 17a and 17b. The recording paper nipped and conveyed by the relay roller pairs 30a and 30b is transferred to the paper discharge roller pairs 31a and 31b of the paper discharge unit 23 so as to push up the switching guide 32 as shown in FIG. 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 and the relay roller 30b, 30c on the driven side in common, and the relay roller pair 30a, 30b While the recording sheet in the transport path f is nipped and conveyed, the relay roller pairs 30a and 30c pinch and transport the recording sheet in the re-transport path r.
[0033]
The reversing unit 24 pushes up the switching guide 32 to transfer the recording sheet nipped and conveyed by the relay roller pair 30a, 30b to the discharge roller pair 31a, 31b of the discharge unit 23. After exiting from the lower surface of the switching guide 32, the discharge roller pair 31a, 31b of the discharge unit 23 is driven to rotate reversely when the duplex mode is designated. 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 discharge roller pair 31a, 31b re-conveys the recording sheet on which an image is formed on one side. By passing the sheet through the path r and nipping and transporting it between the relay roller pairs 30a, 30c, 34a, 34b, 35a, and 35b, the recording sheet, which has been turned upside down, is again passed through the transport path f and the registration of the transport unit 22 is performed. Transfer to roller pair 29a, 29b. As a result, the recording sheet is again conveyed and supplied to the image recording position of the image recording apparatus 10 with the other side (one side on which the image is not recorded) as the image recording surface.
[0034]
The paper transport device 20 is attached to a cassette cover 41 at a lower portion of the apparatus main body and an upper portion of the cassette cover 41 as an exterior cover on a front side (left side in the figure) for operating the apparatus main body (image forming apparatus 100). A front cover (second cover) 42 and a top cover (first cover) 43 attached to the upper surface of the apparatus main body, which is continuous with the front cover 42, are openably and closably mounted. The upper cover 43 is opened and closed while being positioned by engagement / disengagement of a lock mechanism 44 described later provided. Inside the covers 41 to 43, various guide members for defining transport paths f1 to f6 for transporting the recording paper and re-transport paths r1 and r2 are stored. By rotating the guide member in coordination, the transport paths f1 to f6 and the re-transport paths r1 and r2 are opened / closed (open / defined) and the nip pressure of the transfer roller 16 and the like is released. Have been. Needless to say, the image forming apparatus 100 may be installed such that the front cover 42 is on the side.
[0035]
The cassette cover 41 is formed with a pull-out hook 41a to be gripped and attached to the front surface of the paper cassette 25 so that the paper cassette 25 can be slid toward the user and pulled out. Inside the cassette cover 41, a guide member 45 is attached to the apparatus main body so as to be located 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 supply path s that feeds the recording paper drawn upward from the paper cassette 25 and supplies the recording paper to the transport path f1. A pickup roller 26 is rotatably supported on the guide member 45 (apparatus main body) side, and a drive-side relay roller 28a is supported on the drive side. The pickup roller 26 is separated on the cassette cover 41 (paper cassette 25) side. The pad 27 is attached, and the driven-side relay roller 28b is pivotally supported.
[0036]
Thus, when the cassette cover 41 is opened, the paper cassette 25 is pulled out from the lower portion of the apparatus main body, the supply path s 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 if a recording sheet being supplied is nipped, the recording sheet can be collected and removed as it is. The supply path s is also formed continuously between the paper cassette 25 and the lower portion of the cassette cover 41 so that the paper cassette 25 can be stacked in multiple stages as shown in FIG. Has become.
[0037]
Here, the relay roller pairs 28a and 28b are positioned through 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, so that the relay roller pairs 28a and 28b The pressing force is different from that of other roller pairs and the like, and has a mechanism in which a plurality of positioning members are interposed between the rollers 28a and 28b, thereby greatly affecting processing accuracy and assembly accuracy. For this reason, the relay roller pairs 28a and 28b are divided and formed in a short roller shape, are respectively supported by separate roller shafts, and press-contact the driven-side relay roller 28b to the drive-side relay roller 28a. The compression springs are also separately provided. As the compression spring, a spring having a small spring constant and a long stroke length is selected, and is designed to form a mutually pressed state by being largely displaced at the time of pressing. 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 even if the displacement amount of the compression spring varies due to the interposition of a plurality of positioning members, the pressure contact is stable. A force can be obtained, and the recording paper can be reliably and accurately pinched and conveyed and transferred to the downstream side.
[0038]
The front cover 42 is rotatably supported in a direction away from the apparatus main body with a position (lower part of the apparatus main body) close to the upper part of the cassette cover 41 as a rotation fulcrum 42a. With the guide surface 42b on the inner side of the main body facing the upper part of the guide member 45, similarly to the cassette cover 41, a transport path for passing the recording paper that is nipped and transported by the relay roller pairs 28a and 28b and sent out from the supply path s. f1 is defined.
[0039]
As a result, the front cover 42 can open the transport path f1 by rotating about the rotation fulcrum 42a as shown in FIG. 3, so that the recording paper being supplied from the paper cassette 25 can be seen. In this case, the cassette cover 41 can be slightly pulled out to release the nip pressure between the pair of relay rollers 28a and 28b, and the collection and removal can be performed. Therefore, it is possible to collect and remove the recording paper without pulling the staying recording paper forcibly and damaging the relay roller pair 28a, 28b, or breaking and leaving the recording paper.
[0040]
Further, inside the front cover 42, transport paths f1 to f5 substantially parallel to the front cover 42 arranged inside the apparatus main body, and parallel to the front cover 42 arranged outside the apparatus main body. The re-transport path r2 is defined by the guide members 46 to 52. That is, the paper transporting device 20 is constructed vertically so that the recording paper is passed through these transport paths f1 to f5 and the re-transport path r2 and is nipped and transported in the vertical direction.
[0041]
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 the guide members 47 and 48 are attached to the outside of the apparatus main body so as to face the guide member 46. I have. The guide member 46 axially supports the driven registration roller 29b, and 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 disposed above and below the driving registration roller 29a. Guide members 47 and 48 are arranged. That is, between each of the guide members 46 and 47 and each of the guide members 46 and 48, there are defined transfer paths f2 and f3 which are continuous with the transfer path f1. The recording paper delivered to the roller pairs 29a and 29b passes from the transport path f1 to the transport paths f2 and f3.
[0042]
Further, similarly to the front cover 42, the guide member 48 is rotatably supported in a direction away from the apparatus main body, with a lower side near the drive registration roller 29a as a rotation fulcrum 48a. The guide member 48 rotatably supports a transfer roller 16 that is in pressure contact with the transfer belt 15 at an intermediate portion (a position corresponding to the upper side of the guide member 46) inside the apparatus main body. Face the guide member 46 to define the transport path f3. On the upper side of the intermediate portion (transfer roller 16) inside the apparatus main body, the guide member 48 defines a one-side open conveyance path f4 for guiding the recording paper to the fixing roller pair 17a, 17b further downstream. The transfer belt 15 and the transfer roller 16 make contact with the other side of the recording sheet before fixing in which the image has been transferred to one side by the transfer belt 15 and guide it to the pair of fixing rollers 17a and 17b so as not to deteriorate the image quality. .
[0043]
As a result, the guide member 48 can open the transport paths f3 and f4 by rotating about the rotation fulcrum 48a as shown in FIG. Thus, the nip pressure for holding the recording paper can be released. Therefore, when the recording paper being conveyed is being viewed, the recording paper is not pulled without forcibly pulling the recording paper and damaging the transfer belt 15 or the transfer roller 16 or breaking the recording paper. Can be collected and removed.
[0044]
The guide members 49 to 51 are fixed to the apparatus main body. The guide member 49 defines a transport path f4 continuously with the guide member 48 when the front cover 42 is closed, while the guide members 50 and 51 are provided. Defines a transport path f5 between the fixing roller pair 17a, 17b and the relay roller pair 30a, 30b. As a result, the recording paper on which the image has been transferred and formed can be fixed via the fixing roller pairs 17a and 17b, then transferred to the relay roller pairs 30a and 30b, and further conveyed downstream.
[0045]
The guide member 52 is rotatably supported by the front cover 42 with a side near the upper part of the guide surface 42b of the front cover 42 as a rotation fulcrum 52a.
It is located between the guide member 48 and the front cover 42 main body, and can rotate together with the front cover 42 in the direction away from the apparatus main body and simultaneously in the direction away from the front cover 42. The guide member 52 faces the inner surface of the front cover 42, and defines a re-transport path r2 of the recording sheet nipped and transported by the relay roller pairs 34a, 34b, 35a, 35b. The drive side relay rollers 34a and 35a are pivotally supported on the side, while the driven side relay rollers 34b and 35b are pivotally supported on the front cover 42 side.
[0046]
The guide member 52 is provided with a biasing mechanism 61 that includes a resilient member such as a spring and forms a connection mechanism at a position facing the guide member 48, and the biasing mechanism 61 includes a guide mechanism. The guide member 48 is urged in the extending direction while the rear side of the member 52 is pressed against the front cover 42 to position the guide member 48 and press the transfer roller 16 against the transfer belt 15 to press the recording paper. , And the front cover 42 is always urged together with the guide member 52 in the opening direction.
[0047]
Further, a turning lever 63 is rotatably mounted on the upper part of the guide member 52, and the turning lever 63 urges the torsion spring 62 to turn in the direction of the front cover 42. . For this reason, as shown in FIG. 3, 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.
[0048]
As a result, as shown in FIG. 3, the guide member 52 is popped up by the rotation lever 63 in a direction away from the inner surface of the front cover 42 with the rotation of the front cover 42, and expands the re-transport path r2. The nip pressure of the relay roller pair 34a, 34b, 35a, 35b can be released while opening and releasing can be performed. Therefore, when the recording paper being conveyed is peeping, the recording paper is not forcibly pulled to damage the relay roller pairs 34a to 35b or to break the recording paper and leave the recording paper without remaining. Can be collected and removed. Further, as shown in FIG. 4, the guide member 52 can be manually rotated so as to be separated from the inner surface of the front cover 42, so that the recording paper being conveyed can be more easily collected and removed. it can. At this time, the guide member 48 is released from the urging by the urging mechanism 61 and rotated about the rotation fulcrum 48a with the rotation of the guide member 52 (the rotation of the front cover 42). The recording paper can be easily collected and removed from the transport paths f3 and f4.
[0049]
Here, as shown in FIG. 6, the guide member 52 may form a plurality of opening holes 52b on the rotation tip side opposite to the rotation fulcrum 52a, and the opening holes 52b are formed in the re-transport path r2. Is formed so as to be located within the transport range of the recording paper. In this case, as shown in FIG. 7, the recording paper P staying in the re-transport path r2 can be visually recognized through the opening 52b of the guide member 52, and the guide member 52 pops up from the front cover 42. It is not necessary to check the presence or absence of the recording paper P by looking into the expanding re-transport path r2.
[0050]
The upper surface cover 43 is rotatably supported in a direction in which the front side is separated from the upper portion of the front cover 42 with the inside of the upper surface of the apparatus main body as a rotation fulcrum 43a. Guide members 53 and 54 include a transport path f6 through which the recording paper from the transport paths f1 to f5 passes, and a re-transport path r1 through which the recording paper reversely re-transports from the transport path f6 to the image forming position. Is defined by
[0051]
The guide member 53 is attached to the apparatus main body side so as to be continuous with the guide member 50 that defines the transport path f5 on the downstream side of the fixing roller 17a, and faces the inner surface of the upper cover 43 to define the transport path f6. The driven relay roller 30b and the paper discharge roller 31b are pivotally supported by the guide member 53. The guide member 54 is attached to the upper cover 43 so as to be continuous with the upper portion of the guide member 52 defining the re-transport path r2, and faces the inner surface of the upper cover 43 to define the re-transport path r1. The guide member 54 supports the driving-side relay roller 30a and the discharge roller 31a, and the driven-side relay roller 30c that is pressed against the relay roller 30a. The switching member 32 is swingably attached to the guide member 54.
[0052]
Thereby, as shown in FIG. 5, the top cover 43 can open the connecting portion of the transport path f6 and the re-transport paths r1 and r2 by rotating about the rotation fulcrum 43a, and can also relay the relay roller. The nip pressure of the pair 30a, 30b and the discharge roller pair 31a, 31b can be released. Therefore, when the recording paper being conveyed is being peeped, the recording paper is forcibly pulled to damage the relay roller pair 30a, 30b and the paper discharge roller pair 31a, 31b, or to break the recording paper and leave the recording paper. The recording paper can be collected and removed without being lost.
[0053]
Further, as shown in FIG. 8, the paper transporting device 20 has a link mechanism 71 including connecting plates 72 and 73 and rotating levers 74 and 75 on both sides in the paper width direction above the rotating fulcrum 42a of the front cover 42. Attached, it is possible to restrict the front cover 42 from rotating and falling indefinitely, and to make the rotation adjustable.
[0054]
In the link mechanism 71, a base end 72a of a connection plate 72 is rotatably attached to the apparatus body side, and a base end 73a of a connection plate 73 is rotatably mounted to the front cover 42 side. In addition, since the rotating front ends 72b and 73b of the connecting plates 72 and 73 are connected to each other so as to be relatively rotatable, the apparatus main body side can suspend and support the front cover 42. Thereby, the front cover 42 can be closed with the connecting plates 72, 73 folded, and when opened, the connecting plates 72, 73 close the base ends 72a, 73a as shown in FIG. By rotating so as to separate them, the opening (rotating) angle is maintained.
[0055]
Returning to FIG. 8, in the link mechanism 71, the outer peripheral surface of the base end 72a of the connecting plate 72 is formed on the cam surface 72c, and the rotating lever arrays 74 and 75 are connected to the cam surface 72c to be connected. The rotation (opening) of the front cover 42 is adjusted by restricting the rotation of the plates 72 and 73.
[0056]
Specifically, the rotation lever 74 pivotally supports the rotation shaft 17c of the fixing roller 17b, and is rotatably attached to the apparatus main body with the upper portion of the rotation shaft 17c as a rotation fulcrum 74a. A tension spring 76 that urges the fixing roller 17b in a direction to approach the fixing roller 17a to apply a pressing force is attached to a distal end portion that is separated from the fulcrum 74a below the rotation shaft 17c. The rotation lever 75 is rotatably attached to the apparatus main body with the intermediate portion serving as a rotation fulcrum 75 a, and one end 75 b of the rotation lever 75 is pulled by a tension spring 76. The other end 75c is in sliding contact with the cam surface 72c of the connecting plate 72 while being in contact with the pin 74b.
[0057]
The cam surface 72c of the connecting plate 72 changes the distance between the position at which the other end 75c of the rotating lever 75 slides and the base end 72a of the rotating fulcrum, as the connecting plate 72 rotates. When the front cover 42 is closed, the tension spring 76 rotates the rotation lever 74 in a direction in which the fixing roller 17b is pressed against the fixing roller 17a. On the other hand, when the front cover 42 is opened, the rotation lever 74 is rotated in a direction to separate the fixing roller 17b from the fixing roller 17a against the urging force (elastic force) of the tension spring 76. Then, the pressed state of the fixing roller pair 17a, 17b is released to release the nip pressure for nipping the recording sheet. The front cover 42 does not naturally return from the open state to the closing direction due to the biasing force of the tension spring 76 overcoming the rotational force due to its own weight.
[0058]
Thereby, as shown in FIG. 10, when the lock is released by the lock mechanism 44, the front cover 42 is pushed in the opening direction together with the guide member 52 by the urging force (reaction force) of the urging mechanism 61 that presses the guide member 48. Returning to FIG. 8, the connecting plates 72, 73 are turned by the turning levers 74, 75 connected to the cam surface 72c of the connecting plate 72 and pulled by the tension spring 76. Is restricted and held at the pivot position. Therefore, the front cover 42 is held in a state where it is automatically rotated to a position where the upper part is slightly opened, and is suddenly rotated and dropped to a completely open state shown in FIG. Can be prevented from being generated.
[0059]
The lock mechanism 44 of the paper transport device 20 (image forming apparatus 100) includes an engagement lock mechanism 80 shown in FIG. 11 and a positioning lock mechanism (positioning engagement mechanism) 90 shown in FIG. As shown in FIG. 11, the knob 44a of the lock mechanism 44 above the front cover 42 is pinched to release the engagement lock with the apparatus main body by the engagement lock mechanism 80, and as shown in FIG. The mechanism 90 releases the exterior cover from the front cover 42 by simultaneously releasing the state in which the top cover 43 is positioned and locked on the front cover 42 side.
[0060]
Specifically, as shown in FIG. 11, the engagement lock mechanism 80 is constructed by mounting a slide bar 81 inside an upper portion (a tip portion) of the front cover 42, and the slide bar 81 is configured as shown in FIG. As shown in FIG. 11A, the engaging hooks 82 formed at both ends are engaged with the engaging steps 44b on the apparatus main body side to lock the front cover 42 in the closed state, and at the same time, FIGS. As shown in c), when the front cover 42 is slid in the unlocking direction by the knob portion 44a, the engagement of the engagement hook 82 with the engagement step 44b is released to allow the front cover 42 to rotate in the opening direction. .
[0061]
The knob portion 44a is formed integrally with the front cover 42 and protrudes from the upper surface of the front cover 42, and the first protrusion 80a is formed integrally with the slide bar 81 so as to be adjacent to the first protrusion 80a. The first and second projections 80a and 80b are disposed so as to project to the center of the upper surface of the upper surface of the front cover 42.
[0062]
The slide bar 81 has a holding wall 42c protruding from the inner surface of the front cover 42 toward the apparatus body facing the facing wall 83, and a spring 84 is interposed between the holding wall 42c and the facing wall 83. 11 is urged rightward.
[0063]
For this reason, when the front cover 42 is closed, the slide bar 81 is pushed by the spring 84 so that the distal end of the engaging hook 82 rides over the engaging step 44b on the apparatus main body side and the engaging step 44b. , The front cover 42 can be locked in the closed state. When the front cover 42 is opened, the slide bar 81 resists the elastic force of the spring 84 when the first and second protrusions 80a and 80b of the knob 44a are pinched so as to approach each other. Then, the front end of the engaging hook 82 is disengaged from the engaging step 44b on the apparatus main body side by moving relative to the front cover 42 (the apparatus main body) leftward in FIG. 42 can be turned in the opening direction (downward in FIG. 11).
[0064]
Further, the slide bar 81 has a release lever 85 in which one end side end portion 85a is slidably contacted with a ride-over wall 42d protruding from the inner surface of the front cover 42 toward the apparatus main body, and is turned. , And is rotatably supported by the slide bar 81 with the intermediate portion as a rotation fulcrum 85b.
[0065]
The release lever 85 is attached to the slide bar 81 such that the other end is located at the center near the second protrusion 80b, and the other end of the release lever 85 is a side surface (tip portion) of the top cover 43 on the apparatus body side. A protruding piece 85c protruding from the side surface of the slide bar 81 in the direction is formed. The release lever 85 is provided with a spring 86 interposed between the one end portion 85 a and the inner surface of the slide bar 81, and is urged in a rotational direction to bring the projecting piece 85 c closer to the upper surface cover 43.
[0066]
From this, when the front cover 42 is opened, when the first and second protrusions 80a and 80b of the knob portion 44a are pinched so as to approach each other, the slide bar 81 is moved to the front cover 42 (apparatus main body). 11 (a), the release lever 85 is moved to the left in the figure from the state shown in FIG. 11 (a). Get over. At this time, the release lever 85 slides by the elastic force of the spring 84 by engaging the rear end face 85d of the one end side end 85a of the release lever 85 face-to-face with the riding wall 42d on the front cover 42 side, as shown in FIG. The bar 81 is restricted from returning rightward in the figure.
[0067]
On the other hand, when the upper portion of the front cover 42 is closed by abutting the upper portion of the front cover 42 against the side surface of the upper cover 43, the projecting piece 85 c of the release lever 85 abuts against the side surface of the upper cover 43 to resist the elastic force of the spring 86. When the release lever 85 is rotated, the rear end surface 85d of the one end side end portion 85a is disengaged from the riding-over wall 42d on the front cover 42 side where the rear-end surface 85d is engaged. At this time, the slide bar 81 is allowed to return to the left in the drawing due to the elastic force of the spring 84.
[0068]
Therefore, the front cover 42 can slide the slide bar 81 by simply gripping the first and second protrusions 80a and 80b of the knob portion 44a of the lock mechanism 44 to move the engagement hook 82 and the engagement step 44b on the apparatus body side. Can be released and the opening operation of the front cover 42 can be performed. At this time, the release lever 85 restricts the front cover 42 from returning to the state where the slide bar 81 slides in the opposite direction and the engagement hook 82 can be engaged with the engagement step 44b on the apparatus main body side. In the front cover 42 in this state, the projection 85c of the release lever 85 near the upper center is abutted against the side surface of the upper cover 43, so that the engagement hook 82 of the slide bar 81 is engaged with the engagement step 44b on the apparatus body side. It can be returned by sliding in the direction in which the engagement can be locked. That is, when the upper cover 43 is not closed or when the front cover 42 is rotated in the closing direction while supporting one side, the upper side is inclined and the protrusion 85 c of the release lever 85 is moved to the side of the upper cover 43. If the slide bar 81 cannot be properly brought into contact with the apparatus main body, the slide bar 81 cannot be returned to the apparatus main body side by sliding the slide bar 81 in a direction in which the lock can be engaged. As a result, only the front cover 42 cannot be closed, and the front cover 42 can be prevented from appearing to be in a closed state by engagement with only one side of the apparatus body. it can.
[0069]
As shown in FIG. 12, the positioning lock mechanism 90 is constructed by mounting a pressing lever 91 inside a slide bar 81 above the front cover 42 (the distal end portion). Are disposed in the vicinity of the inside of the engagement hooks 82 provided at both ends.
[0070]
As shown in FIG. 12A, the pressing lever 91 has a distal end portion 91a that protrudes toward the upper surface cover 43 and is inserted into the engaging hole 43c opened on the side surface 43b while being guided by the inclined surface 91d. The pressing lever 91 is supported on the inner surface side of the front cover 42 so that the upper end of the pressing lever 91 is rotatable up and down with the upper end on the base end side as a rotation fulcrum 91b. A flange 92c formed at the lower portion is urged by a spring 92 toward the inner surface side of the front cover 42.
[0071]
For this reason, when the pressing lever 91 is closed by abutting the upper portion of the front cover 42 against the side surface 43b of the upper surface cover 43, as shown in FIG. 12B, the distal end portion 91a slides on the inclined surface 91d. While being guided, it is inserted into the engagement hole 43c of the side surface 43b of the upper cover 43. In this state, the rotation of the pressing lever 91 in the opening direction of the upper surface cover 43 can be restricted by the distal end portion 91a engaged with the engaging hole 43c of the side surface 43b. Further, since the pressing lever 91 is urged by the elastic force of the spring 92 so that the tip end portion 91a rotates downward, the pressing lever 91 urges the upper cover 43 downward to define the re-transport path r1. At the same time, the relay roller pairs 30a and 30b and the paper discharge roller pairs 31a and 31b can be pressed against each other with a desired pressing force to lock the position at a position where a nip pressure for clamping the recording paper is generated. On the other hand, when the front cover 42 is opened, the distal end portion 91a of the pressing lever 91 is disengaged from the engagement hole 43c of the side surface 43b of the upper cover 43, so that the positioning lock of the upper cover 43 is released, and It is possible to make it possible to perform the opening operation.
[0072]
Therefore, when closing the outer cover of the sheet transporting device 20 (image forming apparatus 100), simply pressing the front cover 42 following the upper cover 43, the pressing lever 91 on the front cover 42 is moved to the upper surface. The cover 43 is positioned at a predetermined position and locked so as not to be released from the upper cover 43, and the front cover 42 itself is engaged with the engaging hook 82 of the slide bar 81 at the engaging step 44b on the apparatus main body side. Can be locked in a closed state. On the other hand, when the front cover 42 and the top cover 43 are to be opened, the opening operation of the front cover 42 is started simply by gripping the knob 44a on the front cover 42 side as described above, and the positioning lock of the top cover 43 is performed. Can be canceled. At this time, since the front cover 42 is urged by the urging mechanism 61 and rotates in the rotation direction together with the guide members 48 and 52, the transport paths f1, f3, f4 and f6 and the re-transport path r2 are opened. In addition, the nip pressure of the recording paper nipped and conveyed by the transfer belt 15 and the transfer roller 16, the fixing roller pair 17a, 17b, the relay roller pair 30a, 30b, 34a, 34b, 35a, 35b, and the discharge roller pair 31a, 31b. Can be opened.
[0073]
With this configuration, as shown in FIG. 13A, the paper conveyance device 20 can notify a paper jam error to a connected personal computer or operation panel 101 when a paper jam error is displayed. By releasing the positioning lock by gripping the knob 44a of the lock mechanism 44 on the front cover 42, the front cover 42 automatically rotates so as to be separated from the side surface of the upper cover 43, and the re-transport path r1 , R2 are expanded and exposed (see FIG. 10). Accordingly, when the recording paper on which the image has been recorded on one side is staying between the re-transport paths r1 and r2, it can be collected and removed as it is.
[0074]
Then, when the front cover 42 is manually rotated further from the position in the opening direction against the elastic force of the tension spring 76 of the link mechanism 71, as shown in FIG. Accordingly, the guide member 48 rotates together with the guide member 52 to further separate the connecting portion of the re-transport paths r1 and r2 to open the transport path f3 and the like, and at the same time, the transfer belt 15 and the transfer roller 16, The nip pressure of the fixing roller pair 17a and 17b is also released (see FIG. 3). Thus, when the recording paper P is staying on the re-transport path r1 side or the transport path f3, it can be collected and removed as it is.
[0075]
At this time, the guide member 52 pops up so as to be separated from the inner surface of the front cover 42 with the opening of the front cover 42 (see FIG. 3), so that the recording paper staying in the re-transport path r2 can be easily removed. As shown in FIG. 14 (c), the guide member 52 is manually lifted and rotated so as to be separated from the front cover 42 (see FIG. 4), as shown in FIG. 14 (c). As shown in ()), the recording paper P staying in the re-transport path r2 can be easily collected and removed. In this state, the transport path f1 upstream of the pair of registration rollers 29a and 29b is also open, so that the recording paper staying in the transport path f1 or the transport path f2 can be easily visually recognized for collection / removal. can do.
[0076]
The upper cover 43 can also open the upper transfer path f6 by rotating the upper cover 43 in the opening direction as shown in FIG. 15E (see FIG. 5). Thus, as shown in FIG. 15 (f), when the recording sheet P stays between the transport path f6 and the re-transport paths r1 and r2, it can be collected and removed as it is. At this time, the upper cover 43 is in a state where the relay roller pairs 30a and 30b are pressed against each other by its own weight, and releases the nip pressure for nipping the recording paper in the transport path f6.
[0077]
Thereafter, as shown in FIG. 16 (g), the upper cover 43 is rotated in the closing direction, then lifted in the closing direction to support the upper center of the front cover 42, and the front cover 42 is guided. By rotating and pressing together with the member 52 and the guide member 48, the urging mechanism 61 is compressed to generate an urging force, and the engaging lock mechanism 80 and the positioning lock mechanism 90 of the lock mechanism 44 function to properly function. It can be closed.
[0078]
As described above, in the present embodiment, the projecting piece 85c of the release lever 85 at the upper center of the front cover 42 abuts against the side surface 43b of the upper cover 43, and the engaging hook 82 of the slide bar 81 at the upper part of the front cover 42 is engaged. For the first time, when engaged with the engaging step 44b of the apparatus main body and locked in the closed state, the distal end portion 91a of the pressing lever 91 above the front cover 42 is inserted into the engaging hole 43c of the side surface 43b of the upper cover 43 for the first time. The top cover 43 can be positioned and locked at an appropriate position so that it cannot be opened.
[0079]
Accordingly, the top cover 43 can be positioned and locked so as not to be opened by one positioning lock mechanism 90 provided between the front cover 42 and the top cover 43. it can. Further, in conjunction with one operation of opening the front cover 42, the distal end portion 91a of the pressing lever 91 is disengaged from the engagement hole 43c of the side surface 43b of the upper cover 43, and the positioning lock of the upper cover 43 is released. be able to. At this time, the front cover 42 is opened by the urging force of the urging mechanism 61 to completely open the transport paths f1, f3, f4, f6 and the re-transport path r2 in the apparatus main body, and to pinch the staying recording paper. The nip pressure of the transfer roller 16 can be released at the same time.
[0080]
As a result, the image forming apparatus 100 (paper transport apparatus 20) can easily and reliably open and close the front cover 42 and the upper cover 43 in an appropriate order with a simple and inexpensive configuration, and easily recover the jammed recording paper.・ Can be removed.
[0081]
【The invention's effect】
According to the present invention, by abutting the tip of the second cover against the tip of the first cover, the first cover is positioned and engaged by the second cover so that it cannot be opened, and the exterior cover is closed. The cover and the second cover can be positioned and closed while regulating the opening order by one mechanism. Further, when the outer cover is opened, the positioning engagement of the first cover is released and the nip pressure of the roller is released in conjunction with the opening operation of the second cover, so that the opening operation of the outer cover is performed from the second cover. At the same time, the paper in the transport path can be easily collected and removed. Therefore, the exterior cover can be easily and reliably positioned and locked and opened and closed in a simple and inexpensive manner with a simple and inexpensive configuration, and the jam clearance can be easily performed in conjunction with the opening and closing operation.
[0082]
In addition, the second cover is automatically urged in the unlocking direction by, for example, using a mechanism for generating a nip pressure of the roller to be released in the opening direction, thereby releasing the nip pressure of the roller. Therefore, the jam can be easily removed with a simple and inexpensive configuration.
[0083]
Furthermore, by connecting the guides that define the transport path to the first cover and the second cover, the transport path can be fully opened by the operation of opening the first and second covers of the exterior cover, which makes it easier. Jam processing can be performed.
[Brief description of the drawings]
FIG. 1 is a view showing an embodiment of an image forming apparatus equipped with a sheet conveying device according to the present invention, and is a transparent side view showing a schematic overall configuration thereof.
FIG. 2 is a partially enlarged view showing a configuration of a main part thereof.
FIG. 3 is a perspective side view showing an open state of the cover.
FIG. 4 is a transparent side view showing an open state of the cover.
FIG. 5 is a transparent side view showing an open state of the cover.
FIG. 6 is a plan view showing another embodiment of the one part.
FIG. 7 is a plan view illustrating an operation and effect according to another embodiment.
FIG. 8 is a perspective side view showing a main part of an opening mechanism of the cover.
FIG. 9 is a transparent side view showing an open state of the cover.
FIG. 10 is a transparent side view showing an open state of the cover.
FIG. 11 is a partial cross-sectional plan view showing a configuration of a main part thereof.
FIG. 12 is a partially enlarged cross-sectional side view showing a configuration of a main part thereof.
FIG. 13 is a perspective view illustrating an operation of opening and closing the cover.
FIG. 14 is a perspective view for explaining an opening and closing operation of the cover.
FIG. 15 is a perspective view illustrating the operation of opening and closing the cover.
FIG. 16 is a perspective view illustrating an operation of opening and closing the cover.
[Explanation 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
17c Rotary axis
20 Paper transport device
21 Feeding unit
22 Transport unit
23 Paper output unit
24 Inversion section
25 Paper cassette
26 Pickup roller
27 Separation pad
28a, 28b, 30a-30c, 34a-35b Relay roller
29a, 29b Registration roller
31a, 31b discharge rollers
32 Switching guide
41 Cassette cover
42 Front cover
43 Top cover
43b side
43c engagement hole
44 Lock mechanism
44a knob
46-54 Guide member
61 biasing mechanism
71 Link mechanism
72, 73 Connecting plate
74, 75 Rotating lever
76 Extension Spring
80 Engagement lock mechanism
80a, 80b protrusion
81 Slide Bar
82 Engagement hook
84 Spring
85 Release lever
85c protruding piece
86 spring
90 Positioning lock mechanism
91 Push lever
92 spring
100 Image forming apparatus
f1-f6 transport route
P Recording paper
r1, r2 re-transport path

Claims (5)

The apparatus includes a transport path defined in the apparatus main body to transport the paper, a roller for nipping and transporting the paper in the transport path, and an outer cover for accommodating the transport path and the roller in the apparatus main body. A sheet transport device having a set of a first cover and a second cover in which the outer cover opens and closes the front end portion close to and away from each other,
A positioning engagement mechanism for positioning and engaging the first cover at a predetermined position so that the first cover cannot be opened when the front end of the second cover is brought close to the front end of the first cover; And an interlocking mechanism for releasing a nip pressure of a roller for nipping a sheet in the conveyance path in conjunction with the opening operation of the sheet conveyance device. The paper transport device according to claim 1, wherein the interlocking mechanism urges the second cover in an opening direction. The interlocking mechanism is configured so that the elastic force of the elastic member that generates the nip pressure on the roller urges the second cover in the opening direction, so that the second cover can be closed or opened according to the closing / opening operation. 3. The sheet conveying device according to claim 1, wherein the elastic member compresses and expands to generate and release the nip pressure of the roller. The first cover and the second cover are connected to a guide that defines at least one surface side of the transport path, and move the guides along with the opening and closing operation to approach and separate the leading ends of the transport path to move the transport path. 4. The paper transport device according to claim 1, wherein the paper transport device is configured and opened. An image forming apparatus comprising: the sheet conveying device according to any one of claims 1 to 4; and a conveying path for conveying and discharging the sheet to a position where an image is formed.

Images