JP5364626B2 - Conveying device and image forming apparatus provided with conveying device - Google Patents

Description

  The present invention relates to a conveyance device for conveying a sheet and an image forming apparatus including the conveyance device.

  An image forming apparatus such as a copier, a printer, a facsimile machine, or a multifunction machine having these functions generally forms a toner image while conveying a sheet. In the image forming apparatus, a conveyance path for conveying the sheet is formed. In many cases, the image forming apparatus includes a rotatable wall portion for removing a sheet jammed in the conveyance path.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a conveying device disposed below a housing that houses an image forming unit that forms a toner image. A conveyance path for conveying the sheet into the housing is formed in the conveyance device. In order to facilitate removal of a sheet jammed in the conveyance path, an inner cover forming the conveyance path and an outer cover disposed adjacent to the inner cover are rotatably attached to the frame of the conveyance device. The inner cover and the outer cover are connected by a link element. As a result, when the user rotates the outer cover, the inner cover rotates in conjunction with each other, and a sheet jammed in the conveyance path is exposed to the outside.

JP 2004-352380 A

  The transport apparatus of Patent Document 1 includes a positioning mechanism for positioning the inner cover at a predetermined position where the inner cover forms a transport path. In order to operate the positioning mechanism disclosed in Patent Document 1, the user needs to close the outer cover with a relatively strong force.

  In many cases, the outer cover is formed thin for weight reduction. For this reason, the thin outer cover is relatively easily deformed by the force from the user applied to the outer cover and the drag from the positioning mechanism. The deformation of the outer cover results in uncertain positioning of the outer cover and the inner cover connected to the outer cover. For example, when the user applies a force at a position greatly deviated from the center of the outer cover, the outer cover is twisted and deformed, and one positioning mechanism positions the inner cover, while the other positioning mechanism is positioned by the positioning mechanism. Will not be.

  The present invention has been made to solve the above-described problem, and provides a conveyance device having a structure that suppresses deformation of the outer cover and promotes reliable positioning of the inner cover, and an image forming apparatus including the conveyance device. The purpose is to do.

A conveying apparatus according to one aspect of the present invention includes an inner cover that rotates between a first position that guides a sheet to be conveyed, and a second position that is rotated outward from the first position, A rotatable outer cover disposed outward from the inner cover and connected to the outer cover and the inner cover so as to rotate the inner cover in conjunction with the rotation of the outer cover. A link element; and a positioning mechanism that positions the inner cover at the first position. The outer cover includes a protruding piece that protrudes toward the inner cover, and the inner cover has a recess. , in the middle of said cover toward said first position from said second position, by the protruding piece in the recess is at least partially inserted, characterized in that deformation of the outer cover is suppressed .

  According to the above configuration, the inner cover at the first position guides the conveyed sheet. Since the inner cover can be rotated outward toward the second position, the user can preferably remove the jammed sheet in the conveying device. A rotatable outer cover is disposed outside the inner cover. The inner cover and the outer cover are connected by a link element. Therefore, the user can rotate the inner cover between the first position and the second position by rotating the outer cover. A recess is formed in the inner cover, and the outer cover includes a protruding piece. In the middle of the inner cover from the second position to the first position, the protruding piece fits into the recess. As a result, deformation of the outer cover is suitably suppressed, and reliable positioning by the positioning mechanism is promoted.

A conveying device according to another aspect of the present invention includes an inner cover that rotates between a first position that guides a conveyed sheet and a second position that is rotated outward from the first position; A rotatable outer cover disposed outside the inner cover, and connected to the outer cover and the inner cover so as to rotate the inner cover in conjunction with the rotation of the outer cover. A link element and a positioning mechanism for positioning the inner cover at the first position, the inner cover including a protruding piece protruding toward the outer cover, and the outer cover is formed with a recess. It is, in the middle of said cover toward said first position from said second position, by the protruding piece in the recess is at least partially inserted, and wherein the deformation of said outer cover is suppressed To do.

  According to the above configuration, the inner cover at the first position guides the conveyed sheet. Since the inner cover can be rotated outward toward the second position, the user can preferably remove the jammed sheet in the conveying device. A rotatable outer cover is disposed outside the inner cover. The inner cover and the outer cover are connected by a link element. Therefore, the user can rotate the inner cover between the first position and the second position by rotating the outer cover. A recess is formed in the outer cover, and the inner cover includes a protruding piece. In the middle of the inner cover from the second position to the first position, the protruding piece fits into the recess. As a result, deformation of the outer cover is suitably suppressed, and reliable positioning by the positioning mechanism is promoted.

In the above configuration, when the protruding piece is fitted into the concave portion, a surface forming the concave portion is in contact with the protruding piece in a direction along the rotation center axis of the inner cover, and the outer cover is deformed. it is good preferable to be suppressed.

  According to the said structure, since a protrusion piece contacts the surface which forms a recessed part in the direction in alignment with the rotation center axis | shaft of an inner cover, a deformation | transformation of an outer cover is suppressed suitably. As a result, reliable positioning by the positioning mechanism is promoted.

In the above configuration, the protruding piece includes a main body portion protruding from the outer cover toward the inner cover, and a fitting portion protruding from the main body portion and fitted into the concave portion. It is preferable that the main body abuts on the inner cover when inserted into the recess .

  According to the said structure, the external force applied to the outer cover is transmitted to an inner cover through the main-body part of a protrusion piece.

In the above-described configuration, the protruding piece includes a main body portion protruding from the inner cover toward the outer cover, and an insertion portion protruding from the main body portion and fitted into the recess, and the insertion portion is the when fitted into the recess, the body part is good preferable that abuts the outer cover.

  According to the said structure, the external force applied to the outer cover is transmitted to an inner cover through the main-body part of a protrusion piece.

In the above configuration, the frame further includes a frame that rotatably supports the inner cover and the outer cover, and the frame includes a surface on which an opening into which a cassette that stores the sheet is inserted is formed. While the inner cover is in the first position, the outer cover preferably forms another surface opposite to the one surface .

  According to the above configuration, the user can suitably position the inner cover at the first position by fitting the protruding piece into the recess even when the posture during the operation of inserting the cassette is maintained. it can.

In the above configuration, the frame includes an inner wall that is adjacent to a side surface of the inner cover and rotatably supports the inner cover, and the positioning mechanism protrudes from the side surface of the inner cover toward the inner wall. And a groove wall that forms a groove portion that is recessed along the locus of the pin drawn by the rotation of the inner cover, and is disposed to face the groove wall and is rotatable on the inner wall. A hook element that is attached and engages the pin of the inner cover in the first position; and a biasing member that biases the hook element toward the groove wall, wherein the protruding piece includes the hook It is preferred that the recess is fitted into the recess before the element and the pin are engaged .

  According to the above configuration, the projecting piece is fitted into the recess before the inner cover generated when the hook is rotated against the urging member and the drag connected to the inner cover are generated. Therefore, the deformation of the outer cover due to the generation of the drag of the positioning mechanism and the increase of the external force from the user to counter the drag is suitably suppressed. As a result, reliable positioning by the positioning mechanism is promoted.

An image forming apparatus according to still another aspect of the present invention includes an image forming unit that forms an image on a sheet, a housing that houses the image forming unit, and the transport device that transports the sheet into the housing. It is characterized by providing .

  According to the above configuration, since the image forming apparatus includes the above-described transport device, reliable positioning by the positioning mechanism is promoted.

  As described above, the present invention can suppress the deformation of the outer cover and promote the reliable positioning of the inner cover.

1 is a diagram schematically showing an internal structure of an image forming apparatus according to a first embodiment of the present invention. It is a figure which shows the conveying apparatus of the image forming apparatus shown by FIG. It is a perspective view which shows the conveying apparatus from which the top plate was removed. It is a perspective view which shows the guide part of the conveying apparatus shown by FIG. FIG. 4 is a side view of an inner cover and an outer cover of the transport apparatus shown in FIG. 3. It is a perspective view of the inner cover and outer cover rotated to the 2nd position. It is a figure which shows the structure of the inner wall used for the connection of the inner cover shown in FIG. 6, and an outer cover. It is a perspective view which shows the inner cover and outer cover which are in a 1st position. It is a perspective view which shows the inner cover and outer cover in the middle of being rotated from the 2nd position to the 1st position. FIG. 6 is a perspective view of an inner cover and an outer cover used in an image forming apparatus and a conveying device according to a second embodiment of the present invention.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. Note that terms used in the following description, such as “up”, “down”, “left”, “right” and the like, are merely for the purpose of clarifying the explanation and do not limit the present invention. Not what you want. In the following description, the term “sheet” means copy paper, coated paper, OHP sheet, cardboard, postcard, tracing paper, and other sheet materials that are subjected to image forming processing. The term “sheet leading edge” means the edge of the sheet positioned at the leading edge in the sheet conveyance direction. The terms “upstream”, “downstream” and similar terms used in the following description mean “upstream”, “downstream” and similar concepts in the sheet conveyance direction.

  FIG. 1 schematically shows the internal structure of the image forming apparatus. The image forming apparatus shown in FIG. 1 is a printer. However, in another embodiment, an arbitrary apparatus for forming an image such as a copier, a facsimile machine, or a multifunction machine having these functions is used as the image forming apparatus. May be.

  The image forming apparatus 1 is disposed under various apparatuses (for example, an image forming unit 410 described later) for forming an image on a sheet, a housing 2 that houses these devices, and a lower portion of the housing 2. A transfer device 600. In the present embodiment, two transport devices 600 are disposed below the housing 2, but in another embodiment, one transport device 600 may be disposed below the housing 2. In still another embodiment, three or more transfer devices 600 may be disposed below the housing 2. In the present embodiment, the lowermost transport device 600 is referred to as a first transport device 610 for convenience, and is transported between the housing 2 and the first transport device 610. The apparatus 600 is referred to as a second transport apparatus 620.

  The image forming apparatus 1 receives a control signal related to the image forming process from an external device (for example, a personal computer (not shown)), and performs various operations necessary for the image forming process based on the control signal. The image forming apparatus 1 includes a first cassette 631 that is removably accommodated in the first transport device 610, a second cassette 632 that is removably accommodated in the second transport device 620, and a lower portion of the housing 2. It includes a third cassette 633 that is removably accommodated. For example, when the sheets accommodated in the first cassette 631, the second cassette 632, and the third cassette 633 have different dimensions, the image forming apparatus 1 determines whether the sheets are specified by the control signal. Cassettes 631, 632, and 633 serving as sheet supply sources are selected. The image forming apparatus 1 further includes a tray 510. The tray 510 can be rotated up and down with respect to the housing 2. The user may rotate the tray 510 downward and place the sheet on the tray 510. If the control signal from the external device designates the tray 510 as a sheet supply source, the sheet on the tray 510 is pulled into the housing 2.

  An inlet 641 for introducing a sheet is formed on the lower surface of the conveying device 600. Further, a discharge port 642 through which the sheet is discharged is formed on the upper surface of the conveying device 600. In the present embodiment, the lower surface of the transfer device 600 is referred to as a first surface 643 for convenience. Further, the upper surface (that is, the surface opposite to the first surface 643) of the transfer device 600 is referred to as a second surface 644 for convenience. A connection conveyance path 645 extending between the introduction port 641 and the discharge port 642 is formed in the conveyance device 600. The first surface 643 of the second transport device 620 is adjacent to the second surface 644 of the first transport device 610. Further, the discharge port 642 of the first transport device 610 communicates with the introduction port 641 of the second transport device 620. Thus, the connection conveyance path 645 formed in the first conveyance apparatus 610 and the connection conveyance path 645 formed in the second conveyance apparatus 620 are continuously connected.

  Each of the cassettes 631, 632, 633 includes a lift plate 634 for pushing up the leading edge of the sheets stored in the cassettes 631, 632, 633. The conveyance device 600 includes a pickup roller 646 disposed above the downstream end (the right end in FIG. 1) of the lift plate 634. The pickup roller 646 contacts the leading edge of the sheet pushed up by the lift plate 634. By the rotation of the pickup roller 646, the sheet is taken out from the cassettes 631 and 632 and conveyed downstream.

  The conveyance device 600 includes a paper feed roller 647 and a retard roller 648 disposed to face the paper feed roller 647. The pickup roller 646 feeds the sheet between the paper feed roller 647 and the retard roller 648. The paper feed roller 647 rotates to send the sheet further downstream. The rotation of the retard roller 648 is controlled by a torque limiter (not shown). When the pickup roller 646 feeds two or more sheets between the paper feed roller 647 and the retard roller 648, the torque limiter is activated, and the retard roller 648 is made non-rotatable. As a result, the retard roller 648 provides a frictional force that resists the conveyance of a sheet other than the uppermost sheet (a sheet that is in direct contact with the sheet feeding roller 647). When the pickup roller 646 feeds one sheet between the sheet feeding roller 647 and the retard roller 648, the torque limiter does not operate, and the retard roller 648 rotates according to the conveyance of the sheet. As a result, the sheets are sent downstream one by one.

  The conveyance device 600 includes a conveyance roller pair 649 attached to the discharge port 642. The pair of conveyance rollers 649 of the first conveyance device 610 sends the sheet fed by the paper feed roller 647 of the first conveyance device 610 to the introduction port 641 of the second conveyance device 620 through the discharge port 642. The conveyance roller pair 649 of the second conveyance device 620 is configured so that the sheet fed by the paper feed roller 647 of the second conveyance device 620 or the sheet fed by the conveyance roller pair 649 of the first conveyance device 610 is outside the second conveyance device 620. To discharge.

  An introduction port 650 is formed on the lower surface of the housing 2. In addition, an introduction conveyance path 651 extending upward from the introduction port 650 as a base end is formed inside the housing 2. The sheet fed by the pair of conveyance rollers 649 of the second conveyance device 620 is introduced into the introduction conveyance path 651 through the introduction port 650 of the housing 2. Thus, the conveyance device 600 can suitably convey the sheet into the housing 2.

  The image forming apparatus 1 includes a pickup roller 311 disposed above the downstream end (right end in FIG. 1) of the lift plate 634 of the third cassette 633. The pickup roller 311 comes into contact with the leading edge of the sheet pushed up by the lift plate 634. By the rotation of the pickup roller 311, the sheet is taken out from the third cassette 633 and conveyed downstream.

  The image forming apparatus 1 includes a paper feed roller 312 and a retard roller 313 disposed to face the paper feed roller 312. The pickup roller 311 sends the sheet between the paper feed roller 312 and the retard roller 313. The paper feed roller 312 rotates to send the sheet further downstream. The rotation of the retard roller 313 is controlled by a torque limiter (not shown). When the pickup roller 311 feeds two or more sheets between the paper feed roller 312 and the retard roller 313, the torque limiter is activated to make the retard roller 313 non-rotatable. As a result, the retard roller 313 gives a frictional force that resists the conveyance of a sheet other than the uppermost sheet (a sheet that is in direct contact with the paper feed roller 312). When the pickup roller 311 feeds one sheet between the paper feed roller 312 and the retard roller 313, the torque limiter does not operate and the retard roller 313 rotates according to the conveyance of the sheet. Therefore, as a result, the sheets are sent downstream one by one.

  The image forming apparatus 1 includes a registration roller pair 320. The registration roller pair 320 sends the sheet to the image forming unit 410 in synchronization with the image forming process executed by the image forming unit 410. In the housing 2, a first paper feed conveyance path 310 that guides the sheet fed by the paper feed roller 312 to the registration roller pair 320 is formed. Between the registration roller pair 320 and the paper feed roller 312, a transport roller pair 315 for transporting a sheet passing through the first paper feed transport path 310 is disposed. The sheet introduced into the introduction conveyance path 651 or the sheet sent out from the third cassette 633 is conveyed to the registration roller pair 320 by the conveyance roller pair 315.

  The image forming apparatus 1 includes a sheet feeding structure 520 that pulls a sheet on the tray 510 into the housing 2. The sheet feeding structure 520 is disposed so as to be able to come into contact with the lift plate 521 that pushes up the leading edge of the sheet on the tray 510 that is inclined downward toward the housing 2, and the leading edge of the sheet pushed up by the lift plate 521. A sheet feeding roller 522 and a separation pad 523 disposed below the sheet feeding roller 522. When the sheet feed roller 522 rotates, the sheet passes between the sheet feed roller 522 and the separation pad 523. The separation pad 523 gives a frictional force to the sheet passing between the paper feed roller 522 and the separation pad 523. Therefore, when the paper feed roller 522 tries to draw a plurality of sheets into the housing 2, the separation pad 523 is transported to a sheet other than the uppermost sheet (a sheet that directly contacts the paper feed roller 522). A frictional force acting in the opposite direction is applied to prevent the frictional force from being pulled into the housing 2. As a result, the sheets are fed into the housing 2 one by one.

  A second paper feed conveyance path 530 for guiding sheets from the tray 510 is formed in the housing 2. The second paper feed conveyance path 530 extends toward the back wall 24 of the housing 2 above the third cassette 633, and then gradually curves upward and toward the registration roller pair 320. The second paper feed path 530 joins the first paper feed path 310 upstream of the registration roller pair 320. Three conveyance roller pairs 360 are arranged in a substantially straight section of the second paper feed conveyance path 530 before bending upward. The transport roller pair 360 transports the sheet in the second paper feed transport path 530 toward the registration roller pair 320.

  In the housing 2, there are a section from the registration roller pair 320 to the fixing unit 430, a main conveyance path 330 that guides the sheet, a section from the fixing unit 430 to the discharge unit 450, and a discharge conveyance path 340 that guides the sheet. It is formed. The sheet that has reached the registration roller pair 320 is subjected to an image forming process by the image forming unit 410 and a toner image fixing process by the fixing unit 430 while passing through the main conveyance path 330 and the discharge conveyance path 340. Thereafter, if the user causes the image forming apparatus 1 to perform single-sided printing, the sheet is discharged onto the discharge tray 23 that forms a part of the upper surface of the housing 2 through the discharge portion 450 provided in the discharge conveyance path 340. Is done. The discharged sheets are stacked on the paper discharge tray 23.

  When the user causes the image forming apparatus 1 to perform double-sided printing, the discharge unit 450 sends the sheet sent from the fixing unit 430 to the discharge conveyance path 340 out of the case 2 by a predetermined amount, and then enters the case 2. Perform a switchback operation to pull back. The conveyance path further includes a return conveyance path 350 for guiding the sheet pulled back by the discharge unit 450. The return conveyance path 350 extends from the discharge portion 450 toward the back wall 24 of the housing 2 and then extends downward. Thereafter, the return transport path 350 extends toward the first paper feed transport path 310 and joins the first paper feed transport path 310 upstream of the transport roller pair 360. At appropriate positions on the return conveyance path 350, a conveyance roller pair 360 for conveying the sheet guided by these conveyance paths is disposed.

  The image forming unit 410 includes a yellow toner container 900Y, a magenta toner container 900M, a cyan toner container 900C, and a black toner container 900K. Below these containers, developing devices 10Y, 10M, 10C, and 10K corresponding to the respective colors of YMCK are disposed. The image forming unit 410 forms an image on a sheet using toner stored in the toner containers 900Y, 900M, 900C, and 900K.

  The image forming unit 410 includes a photoconductor drum 17 (a photoconductor on which a latent image is formed by an electrophotographic method) that carries a toner image of each color. As the photosensitive drum 17, a photosensitive drum using an amorphous silicon (a-Si) material can be used. The photosensitive drums 17 are supplied with yellow, magenta, cyan, and black toners from the toner containers 900Y, 900M, 900C, and 900K, respectively.

  Around the photosensitive drum 17, a charger 16, a developing device 10 (10Y, 10M, 10C, 10K), a transfer device (transfer roller) 19 and a cleaning device 18 are arranged. The charger 16 uniformly charges the surface of the photosensitive drum 17. The surface of the photosensitive drum 17 after charging is exposed by the exposure unit 94 to form an electrostatic latent image. For example, the exposure unit 94 irradiates a laser beam based on an image signal (a signal including image information) from an external device. The developing devices 10Y, 10M, 10C, and 10K develop the electrostatic latent images formed on the respective photosensitive drums 17 using the toners of the respective colors supplied from the toner containers 900Y, 900M, 900C, and 900K, respectively ( Visualization). The transfer roller 19 forms a nip portion with the photosensitive drum 17 across the intermediate transfer belt 921, and primarily transfers the toner image on the photosensitive drum 17 onto the intermediate transfer belt 921. The cleaning device 18 cleans the peripheral surface of the photosensitive drum 17 after the toner image is transferred.

  Each developing device 10Y, 10M, 10C, 10K includes a developing case 20. A two-component developer having a magnetic carrier and toner is accommodated in the developing case 20. Further, in the developing case 20, two stirring rollers 11 and 12 (developer stirring members) are rotatably arranged in parallel near the bottom of the developing case 20 with the longitudinal direction as an axial direction.

  A developer circulation path is set on the inner bottom surface of the developing case 20, and the stirring rollers 11 and 12 are disposed in the circulation path. A partition wall 201 erected from the bottom of the developing case 20 is provided in the axial direction between the stirring rollers 11 and 12. The partition wall 201 divides the circulation path. A circulation path is formed so as to circulate around the partition wall 201. The two-component developer is charged while being stirred and conveyed on the circulation path by the stirring rollers 11 and 12.

  The two-component developer circulates in the developing case 20 while being stirred by the stirring rollers 11 and 12, and the toner is charged. The two-component developer on the stirring roller 11 is attracted and conveyed by the magnetic roller 14 located on the upper side. The sucked two-component developer forms a magnetic brush (not shown) on the magnetic roller 14. The layer thickness of the magnetic brush is regulated by the doctor blade 13. The toner layer on the developing roller 15 is formed by a potential difference between the magnetic roller 14 and the developing roller 15. The electrostatic latent image on the photosensitive drum 17 is developed by the toner layer.

  The exposure unit 94 includes various optical system devices such as a light source, a polygon mirror, a reflection mirror, and a deflection mirror. Light based on an image signal is provided on the peripheral surface of the photosensitive drum 17 provided in each of the image forming units 410. To form an electrostatic latent image.

  The intermediate transfer unit 92 includes an intermediate transfer belt 921, a driving roller 922, and a driven roller 923. On the intermediate transfer belt 921, toner images are overcoated from a plurality of photosensitive drums 17 (primary transfer). The overcoated toner image is secondarily transferred to a sheet supplied from the cassettes 631, 632, 633 or the tray 510 by the secondary transfer unit 98. A driving roller 922 and a driven roller 923 that rotate the intermediate transfer belt 921 are rotatably supported by the housing 2.

  The sheet fed from the registration roller pair 320 is supplied between the intermediate transfer belt 921 and the transfer roller 981 constituting the secondary transfer unit 98. Thereafter, the sheet is sent to the fixing unit 430 while carrying the toner image transferred by the secondary transfer unit 98.

  The fixing unit 430 includes a heating roller 432 including a heater 431 and a pressure roller 433 pressed against the heating roller 432. The sheet sent out from the secondary transfer unit 98 is sent between the heating roller 432 and the pressure roller 433. The toner on the sheet is melted by receiving heat energy from the heating roller 432 and is fixed to the sheet by receiving pressure from the pressure roller 433. After fixing the toner on the sheet, the fixing unit 430 sends the sheet to the discharge unit 450 via the discharge conveyance path 340.

  The discharge unit 450 includes a discharge roller pair 451. The discharge roller pair 451 is formed so as to be capable of normal rotation and reverse rotation. Thereby, the above-described switchback operation is achieved.

  FIG. 2 shows the transfer device 600. FIG. 2A is a plan view of the transfer device 600. FIG. 2B is a perspective view of the transfer device 600. The conveyance apparatus 600 will be described with reference to FIG. 1 in conjunction with FIG. 2.

  The conveyance device 600 includes a frame body 660 having a substantially rectangular tube shape. The frame 660 forms a third surface 661 that is continuous with the front wall 25 of the housing 2 of the image forming apparatus 1 and a fourth surface 662 that is continuous with the back wall 24 of the housing 2 of the image forming apparatus 1. The frame body 660 includes a pair of side walls 663 extending between both ends of the third surface 661 and the fourth surface 662. The third surfaces 661 of the first transfer device 610 and the second transfer device 620 are used to insert the first cassette 631 and the second cassette 632, respectively.

  The conveyance device 600 includes an outer cover 670 for removing a sheet jammed in the connection conveyance path 645 formed in the frame 660. The outer cover 670 is pivotally connected to a wall portion that forms the fourth surface 662 opposite to the third surface 661 and forms a part of the fourth surface 662. On the outer surface of the outer cover 670, a handle portion 671 that is recessed so that a user's finger is inserted is formed. The user can insert a finger into the handle portion 671 and rotate the outer cover 670 up and down around the lower edge of the outer cover 670 as an axis.

  The conveyance device 600 includes a first top plate 681, a second top plate 682, a third top plate 683, and a fourth top plate 684 that partially close an opening formed on the upper surface of the frame body 660. The first top plate 681, the second top plate 682, the third top plate 683, and the fourth top plate 684 form the second surface 644 of the transfer device 600 described with reference to FIG. The first top plate 681 extends between the upper edges of each of the pair of side walls 663, and the edge of the first top plate 681 forms a discharge port 642. On the lower surface of the first top plate 681, the pickup roller 646, the paper feed roller 647, the driving roller 732 forming the conveying roller pair 649, and the driving device for driving them (not shown) are described. Connected). On the upper surface of the first top plate 681, there is provided a first conductor for conducting electricity between the first transport device 610 and the second transport device 620 or between the second transport device 620 and the housing 2 of the image forming apparatus 1. Two conductive portions 692 are attached. Thus, the second conductive portion 692 is exposed on the second surface 644 of the transfer device 600. The second conductive portion 692 is an elongated plate made of a conductive material, and extends between the pair of side walls 663 on the upper surface of the first top plate 681.

  The second top plate 682 is disposed between the first top plate 681 and the upper edge of the third surface 661. The lower surface of the second top plate 682 of each of the first transport device 610 and the second transport device 620 includes a fan 685 for sending air current into the first cassette 631 and the second cassette 632. The airflow from the fan 685 reduces the suction force between the sheets in the first cassette 631 and the second cassette 632 and suppresses the double feeding of the sheets. Each of the third top plate 683 and the fourth top plate 684 is disposed so as to close a region surrounded by the upper edges of the first top plate, the second top plate 682, and the pair of side walls 663.

  FIG. 3 is a perspective view of the transfer device 600 with the first top plate 681 and the second top plate 682 removed. 3A and 3B are drawn from different angles. The conveyance device 600 will be further described with reference to FIGS. 1 and 2 in conjunction with FIG. 3.

  Openings 664 into which the first cassette 631 and the second cassette 632 are inserted are formed in the third surfaces 661 of the first transport device 610 and the second transport device 620, respectively. In addition, a space for accommodating the first cassette 631 and the second cassette 632 is formed in the frame 660 of the first transport device 610 and the second transport device 620. The user can insert the first cassette 631 and the second cassette 632 into the first transport device 610 and the second transport device 620 through the opening 664, respectively.

  A fan 686 is attached to the inner surface of the side wall 663. The fan 686 sends airflow into the first cassette 631 and the second cassette 632 in the same manner as the fan 685 attached to the second top plate 682 described with reference to FIG. The airflow from the fan 686 reduces the suction force between the sheets in the first cassette 631 and the second cassette 632, and suppresses the double feeding of the sheets.

  The transfer device 600 includes a guide unit 700 disposed in the frame 660. The guide part 700 extends between the inner surfaces of the pair of side walls 663. The guide unit 700 includes a first guide plate 710 that forms a first guide surface 711 that forms a connection conveyance path 645. The first guide surface 711 guides the sheet from the introduction port 641 toward the discharge port 642 as described with reference to FIG. The guide portions 700 of the first transport device 610 and the second transport device 620 further form a second guide surface 721 for guiding the sheet taken out from the first cassette 631 and the second cassette 632 by the pickup roller 646. A guide plate 720 is included. The second guide plate 720 of each of the first conveyance device 610 and the second conveyance device 620 guides the sheet fed from the first cassette 631 and the second cassette 632 toward the discharge port 642. Since the first guide plate 710 and the second guide plate 720 include ribs extending along the sheet conveyance direction and have a relatively complicated shape, the first guide plate 710 and the second guide plate 720 are preferably molded from resin.

  An inner cover 730 is disposed between the outer cover 670 and the first guide plate 710. The inner cover 730 extends between the inner surfaces of the pair of side walls 663 similarly to the guide portion 700. The inner cover 730 rotates up and down in conjunction with the outer cover 670. Therefore, when the user inserts a finger into the handle 671 of the outer cover 670 and rotates the outer cover 670, the inner cover 730 also rotates around the lower edge of the inner cover 730. Thus, the first guide surface 711 is exposed to the outside, and the sheet jammed in the connection conveyance path 645 is suitably removed.

  The introduction port 641 described with reference to FIG. 1 is formed between the lower edge of the inner cover 730 and the lower edge of the guide portion 700. A discharge port 642 described with reference to FIGS. 1 and 2 is formed between the upper edge of the inner cover 730 and the upper edge of the guide portion 700. The inner surface 734 of the inner cover 730 facing the first guide surface 711 of the guide unit 700 cooperates with the first guide surface 711 to form a connection conveyance path 645 and guide the sheet toward the discharge port 642. In the present embodiment, the position of the inner cover 730 that guides the sheet to which the inner surface 734 is conveyed is referred to as a first position for convenience. The outer cover 670 partially forms the fourth surface 662 while the inner cover 730 is in the first position. In the present embodiment, the position where the inner cover 730 is rotated toward the outer cover 670 disposed outside the inner cover 730 is referred to as a second position for convenience. As described above, the inner cover 730 can rotate outwardly of the frame body 660 in conjunction with the outer cover 670.

  The conveyance device 600 includes a shaft 731 supported on the upper portion of the inner cover 730 and a pair of driven rollers 733 supported on the shaft 731. The driven roller 733 is pressed against the driving roller 732 of the conveying roller pair 649 and rotates together with the driving roller 732. Therefore, the driving roller 732 and the driven roller 733 are used as a conveyance roller that conveys the sheet guided by the first guide surface 711 toward the discharge port 642.

  The conveying device 600 includes a reinforcing plate 740 extending in the sheet width direction between the pair of side walls 663. The cross section of the reinforcing plate 740 is substantially L-shaped. The reinforcing plate 740 includes a connection portion 741 connected to the guide portion 700 and a first conductive portion 742 exposed on the lower surface of the frame body 660 (that is, the first surface 643 of the transfer device 600). The reinforcing plate 740 is preferably formed from a conductive metal material in order to achieve both an increase in mechanical strength of the guide portion 700 and a conductive function.

  The first conductive portion 742 of the second transfer device 620 contacts the second conductive portion 692 of the first transfer device 610. Thus, electrical connection between the first conductive unit 742 and the second conductive unit 692 is established, and conduction from the first transfer device 610 to the second transfer device 620 is achieved.

  FIG. 4 is a perspective view of the guide unit 700. 4A and 4B are drawn from different angles. The guide unit 700 will be described with reference to FIG. 1 in conjunction with FIG. 4.

  As described above, the guide unit 700 includes the first guide plate 710 and the second guide plate 720. As described above, the first guide plate 710 includes the first guide surface 711 that forms the connection conveyance path 645 and the reinforcing surface 712 opposite to the first guide surface 711. A connecting portion 741 of the reinforcing plate 740 is connected to the reinforcing surface 712. Thus, deformation of the first guide plate 710 is suppressed. The first guide plate 710 includes a plurality of ribs 713 protruding from the first guide surface 711. The rib 713 extends along the sheet conveyance direction in the connection conveyance path 645.

  The lower surface of the second guide plate 720 is connected to the rib 713. The second guide plate 720 is gently curved upward. The retard roller 648 described with reference to FIG. 1 and the torque limiter 481 for controlling the rotation of the retard roller 648 are embedded in a recess formed in the center of the second guide plate 720.

  FIG. 5 is a side view showing a connection structure between the outer cover 670 and the inner cover 730. The connection structure between the outer cover 670 and the inner cover 730 will be described with reference to FIG.

  Between the outer cover 670 and the inner cover 730, a link rod 750 used as a link element that rotates the inner cover 730 in conjunction with the rotation of the outer cover 670 is disposed. One end of the link bar 750 is rotatably connected to the outer cover 670. The other end of the link bar 750 is connected to the inner cover 730 so as to be rotatable. A rotating shaft 735 protrudes from the lower part of the side surface of the inner cover 730. Further, the rotation shaft 672 protrudes from the lower part of the side surface of the outer cover 670.

  FIG. 6 is a perspective view of the inner cover 730 and the outer cover 670 rotated to the second position. The rotation of the inner cover 730 and the outer cover 670 will be described with reference to FIG. 5 in conjunction with FIG.

  The side wall 663 includes an outer wall 665 that forms a side outer surface of the frame body 660, and an inner wall 666 that extends between the third surface 661 and the fourth surface 662 inside the frame body 660. The rotation shaft 735 of the inner cover 730 and the rotation shaft 672 of the outer cover 670 are rotatably inserted into a recess or an opening formed in the inner wall 666. Thus, the inner wall 666 disposed adjacent to the side surfaces of the inner cover 730 and the outer cover 670 supports the inner cover 730 and the outer cover 670 in a rotatable manner. On the inner wall 666, a positioning mechanism 760 for positioning the inner cover 730 at the first position is constructed.

  FIG. 7 shows a positioning mechanism 760 formed on the inner wall 666. The positioning mechanism 760 will be described with reference to FIGS. 5 and 6 in conjunction with FIG.

  As described above, the inner wall 666 is formed with the recess 667 into which the rotation shaft 735 of the inner cover 730 is inserted. In addition, an opening 669 is formed in the inner wall 666 outward from the recess 667. As described above, the rotation shaft 672 of the outer cover 670 is inserted into the opening 669. The inner cover 730 and the outer cover 670 are rotated around the rotation shafts 735 and 672 inserted in the recess 667 and the opening 669 formed in the inner wall 666.

  The positioning mechanism 760 includes a pin 761 that protrudes from the side surface of the inner cover 730 toward the inner wall 666 above the rotation shaft 735. As shown in FIGS. 6 and 7, the inner wall 666 has a groove 762 recessed along an arcuate locus drawn by the pin 761 while the inner cover 730 is rotating. The groove portion 762 prevents interference between the pin 761 and the inner wall 666. The positioning mechanism 760 includes a groove wall 763 that forms a groove 762. In the present embodiment, the arc-shaped groove wall 763 positioned below the arc-shaped locus drawn by the pin 761 is referred to as a first groove wall 764 for convenience. In addition, above the first groove wall 764, the groove wall 763 along the arcuate locus drawn by the pin 761 is referred to as a second groove wall 765 for convenience. Further, the groove wall 763 that forms the bottom surface of the groove portion 762 between the first groove wall 764 and the second groove wall 765 is referred to as a third groove wall 766 for convenience.

  The positioning mechanism 760 includes a substantially J-shaped hook element 767 that is rotatably attached to the inner wall 666. The hook element 767 is disposed to face the first groove wall 764. The hook element 767 cooperates with the first groove wall 764 to form a space having a substantially C-shaped profile for surrounding and engaging the pin 761 of the inner cover 730 in the first position.

  The positioning mechanism 760 includes a coil spring 768 that is used as a biasing member that biases the hook element 767 toward the first groove wall 764. The upper end of the coil spring 768 is connected to an upper edge wall 691 extending inward from the upper edge of the inner wall 666. The lower end of the coil spring 768 is connected to the upper surface of the substantially pentagonal tip 769 of the hook element 767. When the inner cover 730 moves from the second position toward the first position, the pin 761 moves along the groove 762. The pin 761 reaches a position where it contacts the proximal end portion 770 of the hook element 767 connected to the distal end portion 769 while pushing up the distal end portion 769 of the hook element 767 against the coil spring 768. At this time, the distal end portion 769 of the hook element 767 is pushed down by the restoration of the coil spring 768. As a result, the pin 761 is engaged by the tip end portion 769 of the hook element 767 protruding toward the first groove wall 764, and the inner cover 730 is positioned at the first position.

  FIG. 8 is a perspective view showing the inner cover 730 and the outer cover 670 in the first position. The inner cover 730 and the outer cover 670 will be further described with reference to FIGS. 5 and 6 in conjunction with FIG.

  The outer cover 670 includes a substantially T-shaped protruding piece 673 that protrudes toward the inner cover 730. The protruding piece 673 includes a main body portion 674 that protrudes from the upper edge of the inner surface of the outer cover 670 facing the inner cover 730 toward the inner cover 730, and a fitting portion 675 that is formed narrower than the main body portion 674. The fitting portion 675 protrudes further toward the inner cover 730 from the tip edge of the main body portion 674.

  The inner cover 730 includes a receiving portion 736 for receiving the protruding piece 673. The receiving portion 736 protrudes toward the outer cover 670 at the upper portion of the outer surface 737 opposite to the inner surface 734 of the inner cover 730. The receiving portion 736 is formed with a concave portion 738 extending in the vertical direction. The concave portion 738 has a width complementary to the width of the fitting portion 675 of the protruding piece 673, and the fitting portion 675 is fitted into the concave portion 738. In this embodiment, the engagement between the recess 738 and the insertion portion 675 is achieved at a position along the center position in the width direction of the sheet, but the engagement between the recess 738 and the insertion portion 675 is formed at other positions. May be.

  FIG. 9 is a perspective view showing the inner cover 730 and the outer cover 670 on the way from the second position to the first position. Note that the pin 761 of the inner cover 730 shown in FIG. 9 is in a position just before engaging with the hook element 767 described with reference to FIG. The effect of meshing between the recess 738 and the protruding piece 673 will be described with reference to FIGS. 5 to 7 in conjunction with FIG.

  For example, when the user applies an external force F1 to the right of the handle portion 671 formed at the center of the outer cover 670 and tries to rotate the outer cover 670 upward, the drag force and the external force F1 received from the hook element 767 are applied. Is transmitted to the outer cover 670, and the outer cover 670 tries to deform so as to be twisted. As a result, a force for moving the protruding piece 673 to the left acts on the outer cover 670. As shown in FIG. 9, the insertion portion 675 of the protruding piece 673 is inserted into the recess 738 on the way from the second position to the first position. Since the surface forming the recess 738 contacts the edge (side edge) of the fitting portion 675 in the direction along the rotation center axis of the inner cover 730 and / or the outer cover 670, deformation of the outer cover 670 is suppressed. It will be.

  When the fitting portion 675 is fitted into the recess 738, the leading edge of the main body portion 674 comes into contact with the receiving portion 736 of the inner cover 730. Thus, the projecting piece 673 plays a role of pushing the inner cover 730 into the first position in cooperation with the link rod 750.

(Second Embodiment)
FIG. 10 is a perspective view of an outer cover and an inner cover according to the second embodiment. The inner cover and the outer cover shown in FIG. 10 are in the first position. The inner cover and the outer cover of the second embodiment are different from the first embodiment in the formation of the protruding pieces and the recesses, but other structures and shapes are in accordance with the first embodiment. Hereinafter, differences from the first embodiment will be described.

  As shown in FIG. 10, the protruding piece 673A may protrude from the inner cover 730A toward the outer cover 670A. In the present embodiment, a recess 738A is formed in the outer cover 670A. Similar to the protruding piece 673 of the first embodiment, the protruding piece 673A is formed in a substantially T shape, and protrudes from the inner cover 730A toward the outer cover 670A, and a fitting portion 675A protruding from the main body portion 674A. Including. The fitting portion 675A is fitted into the recess 738A as in the first embodiment.

  Also with the structure of the protruding piece 673A and the recess 738A shown in FIG. 10, the fitting portion 675A is fitted into the recess 738A in the middle of the inner cover 730A toward the second position, and the deformation of the outer cover 670A is suitably suppressed. It becomes. Further, while the fitting portion 675A is fitted in the recess 738A, the front end edge of the main body portion 674A is in contact with the outer cover 670A, and the external force F1 applied to the outer cover 670A is suitably applied to the inner cover 730A. Can communicate.

  The present invention can be applied to a printer, a copier, a facsimile machine, a multifunction machine having these functions, and various apparatuses for forming an image on a sheet.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 2 ... Housing | casing 410 ... Image forming part 600 ... Conveying device 660 ... Frame body 661 ... 3rd surface (one surface)
662 ... Fourth surface (other surface)
664... Opening 666... Inner wall 670... Outer cover 670 A... Outer cover 673... Projection piece 673 A... Projection piece 674. 675A ··· insertion portion 730 ··· inner cover 730A ··· inner cover 738 ··· concave portion 738A ··· concave portion 750 ··· link bar (link element)
760 ... Positioning mechanism 761 ... Pin 762 ... Groove 763 ... Groove wall 767 ... Hook element 768 ... Coil spring (biasing member)

Claims (9)

An inner cover that rotates between a first position that guides the conveyed sheet and a second position that is rotated outward from the first position;
A rotatable outer cover disposed outward from the inner cover;
A link element connected to the outer cover and the inner cover so as to rotate the inner cover in conjunction with the rotation of the outer cover;
A positioning mechanism for positioning the inner cover at the first position;
The outer cover includes a protruding piece protruding toward the inner cover,
The inner cover is formed with a recess,
In the middle of the inner cover from the second position to the first position, the projecting piece is inserted into the recess at least partially so that deformation of the outer cover is suppressed. apparatus. An inner cover that rotates between a first position that guides the conveyed sheet and a second position that is rotated outward from the first position;
A rotatable outer cover disposed outward from the inner cover;
A link element connected to the outer cover and the inner cover so as to rotate the inner cover in conjunction with the rotation of the outer cover;
A positioning mechanism for positioning the inner cover at the first position;
The inner cover includes a protruding piece protruding toward the outer cover,
The outer cover is formed with a recess,
In the middle of the inner cover from the second position to the first position, the projecting piece is inserted into the recess at least partially so that deformation of the outer cover is suppressed. apparatus. When the projecting piece is inserted into the recess, the surface forming the recess comes into contact with the projecting piece in a direction along the rotation center axis of the inner cover, and deformation of the outer cover is suppressed. The conveying apparatus according to claim 1 . When the projecting piece is inserted into the recess, the surface forming the recess comes into contact with the projecting piece in a direction along the rotation center axis of the inner cover, and deformation of the outer cover is suppressed. The conveying apparatus according to claim 2 . The projecting piece includes a main body portion projecting from the outer cover toward the inner cover, and a fitting portion projecting from the main body portion and fitted into the concave portion,
4. The transport device according to claim 1, wherein the main body abuts on the inner cover when the insertion portion is inserted into the recess . 5. The projecting piece includes a main body portion projecting from the inner cover toward the outer cover, and a fitting portion projecting from the main body portion and fitted into the concave portion,
5. The transport device according to claim 2, wherein the main body abuts on the outer cover when the insertion portion is inserted into the recess . A frame that rotatably supports the inner cover and the outer cover;
The frame includes one surface on which an opening into which a cassette for storing the sheet is inserted is formed,
7. The transport device according to claim 1, wherein the outer cover forms another surface opposite to the one surface while the inner cover is in the first position. 8. . The frame includes an inner wall that is adjacent to a side surface of the inner cover and that rotatably supports the inner cover;
The positioning mechanism includes a pin that protrudes from the side surface of the inner cover toward the inner wall, a groove wall that forms a groove portion that is recessed along the locus of the pin drawn by the rotation of the inner cover, A hook element that is pivotally attached to the inner wall facing the groove wall and engages with the pin of the inner cover in the first position, and a bias that biases the hook element toward the groove wall And a member,
The conveying device according to claim 7, wherein the protruding piece is fitted into the recess before the hook element and the pin are engaged . An image forming unit for forming an image on a sheet;
A housing that houses the image forming unit;
An image forming apparatus comprising: the conveying device according to claim 1, which conveys the sheet into the housing.

Images