JP3993960B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a duplex unit that reverses a sheet for duplex printing.HaveThe present invention relates to an image forming apparatus.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as an example of an image forming apparatus that forms images on both sides of a sheet, there is a type in which a duplex unit 101 for reversing a sheet is retrofitted to the side surface of a main body case 102 as shown in FIG. The double-sided unit 101 is rotatable in a direction away from the main body case 102 with a first support shaft (not shown) provided below the double-sided unit 101 as a rotation center.
[0003]
Below the duplex unit 101, a manual paper feed tray 103 that accepts manual paper feed is provided. The manual paper feed tray 103 is rotatably provided in a direction away from the main body case 102 with the second support shaft 104 as a rotation center.
[0004]
In addition, the main body case 102 is provided with a paper feed tray 105 and a paper discharge stacker unit 106. A paper conveyance path 109 is formed in the main body case 102 from the paper feed tray 105 and the manual paper feed tray 103 to the paper discharge stacker unit 106 via the image forming unit 107 and the fixing unit 108.
[0005]
In the case 110 of the duplex unit 101, a reversing path 111 that branches from the paper transport path 109 and a refeed path 112 that branches from the reversing path 111 are formed. A reversing roller 113 that can rotate forward and backward is provided at a branch point between the reversing path 111 and the refeeding path 112. The other end of the inversion path 111 is connected to an opening 114 provided on the side surface of the duplex unit 101 and opening outward. The opening 114 is closed by the reversing guide plate 115. The reversing guide plate 115 is provided so as to be rotatable in a direction away from the double-sided unit 101 with a support shaft 116 provided in the double-sided unit 101 as a rotation center.
[0006]
In such a structure, the paper conveyed from the paper feed tray 105 or the manual paper feed tray 103 is formed with an image by the image forming unit 107 while being conveyed through the paper conveyance path 109, and the paper discharge stacker unit 106. It is conveyed to. When images are formed on both sides of the paper, the paper reversed by the reversing path 111 is transported to the refeed path 112 and transported again to the paper transporting path 109 to form an image.
[0007]
At this time, when a jam such as paper jamming in the paper transport path 109 occurs, the double-sided unit 101 is rotated in a direction away from the main body case 102 with the first support shaft as a rotation center. Make space. Then, put a hand in this space and remove the jammed paper.
[0008]
Here, in the case of a large-size sheet in which the length of the sheet to be reversed in the conveyance direction is longer than the reversing path length, the opening 114 is opened by rotating the reversing guide plate 115 about the support shaft 116, and the reversing path is opened. The leading edge of the paper longer than the length is projected out of the duplex unit 101. The reversing guide plate 115 guides the paper protruding from the opening 114 while being opened in a direction away from the duplex unit 101.
[0009]
[Problems to be solved by the invention]
However, in the image forming apparatus having such a structure, since the manual paper feed tray 103 projects to the side of the duplex unit 101, a person passing near the apparatus may hit the manual paper feed tray 103. The device may be damaged. When the apparatus is transported, the overhanging manual feed tray 103 may collide with the surrounding area and the apparatus may be damaged.
[0010]
Further, when the apparatus is transferred, the manual paper feed tray 103 may open due to vibration. There may be a case where a person collides with the opened manual paper feed tray 103 to damage the apparatus.
[0011]
When opening the duplex unit 101, the manual feed tray 103 is first opened and then the duplex unit 101 is opened. Even when the duplex unit 101 is closed, it is necessary to follow a two-step procedure of closing the manual feed tray 103 after the duplex unit 101 is closed. That is, since the manual feed tray 103 prevents the duplex unit 101 from being opened and closed, there is a problem in that the duplex unit 101 cannot be directly opened and closed and the operation is troublesome.
[0012]
Further, when the reversing guide plate 115 is opened in order to reverse a large-sized sheet longer than the reversing path length, the reversing guide plate 115 projects to the side of the apparatus and requires a large installation space. The plate 115 is retracted to the side of the duplex unit 101 in a substantially raised state along the image forming apparatus main body. For this reason, when reversing a large-sized sheet, the reversing guide plate 115 must be rotated about the support shaft 116 to open the opening 114, and the operation becomes complicated. There is a problem that it ends up. Also, when reversing large-size paper with the image forming device installed at a location away from the operator and being used remotely, the operator has to go to the place where the device is installed, There is also a problem that the reversing guide plate 115 needs to be rotated around the support shaft 116 to open the opening 114, and the operation becomes complicated. In order to solve this problem, when a device for opening the reversing guide plate by remote operation is provided, there is a problem that the number of parts increases or the installation space increases.
[0013]
An object of the present invention is to prevent the manual paper feed tray from being damaged by eliminating the protrusion of the manual paper feed tray.
[0014]
An object of the present invention is to improve the opening / closing operability of a duplex unit in an image forming apparatus provided with a manual paper feed tray.
[0015]
An object of the present invention is to obtain a duplex unit capable of reversing sheets of various sizes without performing complicated operations.
[0016]
An object of the present invention is to obtain a duplex unit that can invert sheets of various sizes without increasing the number of parts.
[0017]
An object of the present invention is to obtain a duplex unit capable of reversing sheets of various sizes without increasing the installation space of the apparatus.
[0018]
[Means for Solving the Problems]
[0019]
  The image forming apparatus according to claim 1, wherein the double-sided unit rotatably attached with the first support shaft provided on the double-sided unit attachment side of the main body case including the image forming unit as a rotation center; A paper reversing path for refeeding the supplied paper provided in the duplex unit and a second support shaft provided horizontally on the duplex unit mounting side of the main body case is rotatable about the rotation center. A manual paper feed tray that allows paper to be fed from a manual paper feed port provided on the double-side unit attachment side of the image forming apparatus by rotating, and the double-side unit includes the manual paper feed tray. A storage recess for storing the paper tray without projecting is provided, the second support shaft is attached to a portion other than the duplex unit, and the rotation angle of the manual feed tray is the rotation of the duplex unit. The manual feed tray support position by the second support shaft is disposed inside the support position of the duplex unit by the first support shaft, and the first support shaft and the The second support shaft is provided coaxially.
  According to a second aspect of the present invention, there is provided the image forming apparatus according to the first aspect, wherein an engaging means for fitting the concave portion and the convex portion is provided between the duplex unit and the manual paper feed tray.
  Here, the protrusion means that the manual paper feed tray projects so as to hit a person passing nearby.
[0020]
Therefore, the manual feed tray is stored without protruding from the case.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS. The duplex unit of this embodiment is an example applied to an electrophotographic image forming apparatus.
[0040]
Such an image forming apparatus includes a main body case in which an image forming unit is built in, and a duplex unit and a manual sheet feeding unit that are optionally attached to the main body.
[0041]
First, the main body case will be described based on a longitudinal side view showing a part of the image forming apparatus of FIG. Formed in the main body case 1 is a paper transport path 5 from the paper feed tray 2 to the paper discharge stacker (not shown) via the image forming unit 3 and the fixing unit 4.
[0042]
A reverse sheet discharge port 6, a refeed port 7, and a manual sheet feed port 8 that open toward the double-side unit mounting surface side are provided on the outer periphery of the main body case 1. The reverse paper discharge port 6 is branched from the paper transport path 5 and is opened downstream of the image forming unit 3 in the paper transport direction. The paper discharge stacker unit and the reverse paper discharge port 6 are opened by a switching claw 9 so as to be freely switched. Further, the sheet re-feed port 7 is connected to the sheet conveyance path 5 on the upstream side in the sheet conveyance direction from the image forming unit 3.
[0043]
Then, around the photoconductor 10 positioned at the center of the image forming unit 3, a charger 11 that uniformly charges the photoconductor 10 and an image read by a scanner unit (not shown) are exposed on the photoconductor 10 by an exposure unit (not shown). The developing unit 12 forms a toner image by attaching toner to the electrostatic latent image formed by exposing the toner, the transfer unit 13 for transferring the toner image to the conveyed paper, and the charge on the photoconductor 10. A static eliminator 14 that cleans up, a cleaner 15 that removes toner remaining on the photoreceptor 10, and the like are provided.
[0044]
The fixing unit 4 that fixes the transferred toner image on the paper is provided with a pressure roller 16 and a heating roller 17.
[0045]
Next, the duplex unit 18A will be described. The case 18 of the double-sided unit 18A is attached to the attachment surface (right side) side of the double-sided unit of the main body case 1 as shown in FIG.
[0046]
In the case 18, there is provided a paper reversing passage 19 for reversing the paper supplied from the reversing paper discharge port 6 and having an image formed on one side thereof and refeeding it to the refeeding port 7. The sheet reversing path 19 includes a reversing path 20 and a refeeding path 21 that branches from the reversing path 20. One end of the reversing path 20 is connected to the reversing paper discharge port 6 through the reversing paper supply port 20 a, and the other end is connected to the opening 39. One end of the refeed path 21 is connected to a branch point with the reversing path 20, and the other end is connected to the refeed slot 7 via a refeed sheet discharge port 21a.
[0047]
A reversing roller 22 and a switching claw 23 are provided at a branch point between the reversing path 20 and the refeeding path 21. The reverse roller 22 is provided so as to be rotatable forward and backward, and conveys the paper guided from the reverse paper discharge port 6 to the refeed path 21. The switching claw 23 switches the reversing path 20 and the refeeding path 21 so as to be switchable.
[0048]
Further, the refeed path 21 is provided with a plurality of sets of transport rollers 24 for transporting the reversed paper to the refeed port 7.
[0049]
FIG. 2 is a side view showing a part of the image forming apparatus including the duplex unit 18A. The case 18 of the duplex unit 18A is fixedly provided with hinge pieces 25 protruding downward from both sides in the direction perpendicular to the paper surface. These hinge pieces 25 are first provided horizontally on the paper feed unit 26. Is pivotably mounted with the support shaft 27 as a rotation center.
[0050]
Further, as shown in FIGS. 2 to 3, the duplex unit 18A is provided with a storage recess 29 for storing the manual sheet feed tray 28. FIG. 3 is a perspective view illustrating a part of an image forming apparatus including a duplex unit. As shown in FIGS. 2 to 3B, the manual paper feed tray 28 is rotatably provided with a second support shaft 30 provided horizontally in the paper supply unit 26 as a rotation center. In addition, a manual paper feed path 31 for guiding paper from the manual paper feed tray 28 to the manual paper feed port 8 is formed in the paper feed unit 26, and the manual feed path 31 is interposed between the paper feed roller 32 and the manual paper feed path 31. The friction pad 33 pressed against the paper feed roller 32 is disposed oppositely. The paper feed unit 26 and the manual paper feed tray 28 constitute a manual paper feed unit 34.
[0051]
The manual paper feed tray 28 and the case 18 of the duplex unit 18 </ b> A detachably engage a convex portion 35 provided at one end of the manual paper feed tray 28 with a concave portion 36 provided in the storage concave portion 29. Is engaged by. These convex portions 35 and concave portions 36 constitute engaging means 37.
[0052]
The engaging means 37 will be described with reference to FIGS. 4 is an enlarged perspective view of the engaging means 37, FIG. 5 is an enlarged perspective view of the concave portion 36, and FIG. 6 is a horizontal sectional view showing a fitting state of the concave portion 36 and the convex portion 35. The recess 36 is a long hole extending in the vertical direction. The convex portion 35 is engaged with a part of the concave portion 36. In addition, a slope 36 a is formed at the lower end of the recess 36 so that the depth from the bottom surface of the recess 36 gradually decreases as the manual feed tray 28 is opened. For this reason, when the case 18 is in the closed position, the engagement is easily released by the projection 35 getting over the slope 36a. When the convex portion 35 climbs over the slope 36 a, the slope 36 a with which the convex portion 35 abuts or the storage concave portion 29 is pushed by the convex portion 35, and the movement of the convex portion 35 due to the rotation of the manual feed tray 28 is allowed. Transforms into
[0053]
Such an image forming apparatus is provided with a control unit (not shown) that controls the switching operation, the image forming operation, and the like of the paper transport path 5, the reverse paper discharge port 6, the reverse path 20, and the refeed path 21. It has been.
[0054]
A case where an image forming operation is performed in such a configuration will be described. First, in the image forming unit 3, exposure corresponding to the image read by the scanner unit is performed on the photoreceptor 10 uniformly charged by the charger 11. By exposing, an electrostatic latent image is formed on the photoreceptor 10. A toner image is formed on the photosensitive member 10 by attaching a toner to which electric charges are applied to the electrostatic latent image. This toner image is transferred to the paper by applying a bias when the paper conveyed by adjusting the timing from the paper feed tray 2 or the manual paper feed tray 28 passes through the transfer device 13. The toner image transferred to the sheet is fixed on the sheet by being pressurized and heated by passing between the pressure roller 16 and the heating roller 17 when the sheet passes through the fixing unit 4.
[0055]
When an image is formed on one side of a sheet, the sheet that has passed through the fixing unit 4 is conveyed to a sheet discharge stacker unit.
[0056]
On the other hand, when forming images on both sides of the paper, the switching claw 9 is switched from the fixing unit 4 to the reverse paper discharge port 6 to rotate the reverse roller 22 in the direction in which the paper is conveyed to the reverse path 20. A sheet on which an image is formed on one side is conveyed to the reverse path 20 by the reverse roller 22. After the trailing edge of the sheet passes through the switching claw 23, the switching claw 23 is switched to connect the reversing path 20 and the refeed path 21. Then, the reverse roller 22 is rotated in the direction in which the paper is conveyed to the refeed path 21 while the trailing edge of the paper conveyed to the reverse path 20 is in contact with the reverse roller 22. As a result, the sheet conveyed to the reversing path 20 is conveyed to the refeed path 21 by the reversing roller 22. Then, the sheet conveyed to the refeed path 21 is refeeded from the refeed port 7 to the sheet transport path 5 by the transport roller 24.
[0057]
Next, the paper transported to the paper transport path 5 is transported to the image forming unit 3 with timing adjustment. In the image forming unit 3, the toner image for the back surface formed on the photoconductor 10 by the above-described image forming operation is transferred to the back surface of the paper, and this toner image is fixed by the fixing unit 4.
[0058]
The paper on which images are formed on both sides in this way is discharged to the paper discharge stacker section by switching the paper transport path 5 to the paper discharge stacker section by the switching claw 9.
[0059]
Next, a case where an image is formed on a manually fed sheet will be described. First, the manual paper feed tray 28 rotates in a direction away from the case 18 with the second support shaft 30 as a rotation center. As a result, the convex portion 35 climbs over the inclined surface 36a as indicated by an arrow in FIG. 5, and the engagement between the case 18 and the manual paper feed tray 28 is released. When the manual paper feed tray 28 is rotated to a predetermined position, the manual paper feed port 8 closed by the manual paper feed tray 28 is opened, and the manual paper feed path connected from the manual paper feed tray 28 to the paper transport path 5 is opened. A paper path 31 is formed. The manually fed sheet is conveyed from the manual sheet feeding path 31 to the sheet conveying path 5, and an image is formed on one or both sides by the above-described image forming operation, and the sheet is discharged to a sheet discharge stacker unit.
[0060]
Next, a paper removal operation when paper is jammed in the paper conveyance path 5 will be described. First, the case 18 rotates in a direction away from the main body case 1 with the first support shaft 27 as a rotation center. Then, the manual paper feed tray 28 is pushed by the case 18 and rotates in a direction away from the main body case 1 with the second support shaft 30 as a rotation center.
[0061]
At this time, since the rotation center of the case 18 and the manual paper feed tray 28 is different, the relative positional relationship between the convex portion 35 and the concave portion 36 is changed by the rotation. That is, as shown in FIG. 2, when the case 18 rotates around the first support shaft 27, the recess 36 has a circumference whose radius is the distance from the first support shaft 27 to the recess 36. Move up (A shows the trajectory of the upper end). Then, the case 18 engaged by the engaging means 37 rotates about the first support shaft 27 as a rotation center, so that the convex portion 35 has the second support shaft 30 as the rotation center. It moves on a circle whose radius is the distance from 30 to the convex portion 35 (B shows the movement locus of the convex portion 35). Since the concave portion 36 of the engaging means 37 is a long hole, the movement locus A of the concave portion 36 overlaps the movement locus B of the convex portion 35. For this reason, even if the convex part 35 slides the concave part 36 upward while changing the position by the rotation, and the positional deviation occurs between the duplex unit 18A and the manual paper feed tray 28 by the rotation, the convex part 35 is not affected. The match is maintained. As a result, the sheet conveying path 5 can be opened by rotating the case 18 in a direction away from the main body case 1 while the duplex unit 18A and the manual sheet feeding tray 28 are engaged.
[0062]
As the case 18 rotates, a space is formed in the paper transport path 5, and the operator puts his hand in this space and removes the jammed paper.
[0063]
Next, an operation for closing the case 18 after the jam is released will be described. First, the case 18 rotates in the direction of the main body case 1 with the first support shaft 27 as a rotation center. At this time, the manual feed tray 28 engaged with the case 18 is interlocked with the engaging means 37 and rotates in the direction of the main body case 1 with the second support shaft 30 as the rotation center. Here, since the rotation center of the case 18 and the manual feed tray 28 is different, the relative positional relationship between the concave portion 36 and the convex portion 35 is changed by the rotation. In response to this change in the positional relationship, in the engaging means 37, the convex portion 35 slides in the concave portion 36 and moves the engaging position. As a result, the case 18 and the manual paper feed tray 28 are interlocked and rotated while being engaged.
[0064]
Here, when the case 18 is closed, as shown in FIG. 6A, the engaging position between the concave portion 36 and the convex portion 35 is at the end portion on the inclined surface 36a side. It can be easily attached and detached, and only the manual paper feed tray 28 can be smoothly rotated. On the other hand, when the case 18 is opened by turning, the engagement position moves to the upper end side of the recess 36 as shown in FIG. Engagement force with the concave portion 36 becomes strong, and the manual paper feed tray 28 does not open carelessly while performing work.
[0065]
Further, when the jam processing is performed, when the duplex unit 18A is rotated outward about the first support shaft 27, the first support shaft 27 that rotates the duplex unit 18A is below the duplex unit 18A. Further, since it is disposed at a position away from the main body case 1, the inner surface (particularly the lower surface) of the double-sided unit 18 </ b> A is largely separated from the main body case 1 when the double-sided unit 18 </ b> A is rotated outward. Can be made. Thereby, the jam processing can be easily performed. Furthermore, according to the arrangement of the first support shaft 27, the center of gravity of the double-sided unit 18A can be positioned closer to the main body case 1 than the center of the first support shaft 27. Can be applied to the main body case 1 side. Therefore, when providing a lock mechanism (not shown) for locking the duplex unit 18A in a vertical posture, an inexpensive and simple lock mechanism can be used.
[0066]
Note that the convex portion 35 and the concave portion 36 may be interchanged between the case 18 and the manual paper feed tray 28.
[0067]
Further, the first support shaft 27 and the second support shaft 30 may be provided at the same position.
[0068]
Next, a second embodiment of the present invention will be described with reference to FIGS. The same parts as those in the above embodiment are denoted by the same reference numerals, and the description thereof is also omitted. FIG. 7 is an enlarged perspective view of the concave portion, and FIG. 8 is a horizontal sectional view showing a fitting state of the concave portion and the convex portion.
[0069]
The image forming apparatus according to the present embodiment includes a duplex unit 18A attached to the main body case 1 and a manual sheet feeding unit 34. The difference from the first embodiment is that both the storage recesses 29 are provided. The only difference is the shape of the recess 38 formed on the inner surface. The description of other structures is omitted because they are the same.
[0070]
That is, the concave portion 38 having a long hole shape in the vertical direction has a portion 38a having a shallow depth at the lower end and a portion 38b having a deep depth from the center to the upper end. In this example, the depth of the recess 38 is changed by projecting the upper portions of both side surfaces of the storage recess 29 inward.
[0071]
In such a configuration, when the duplex unit 18A is closed, the convex portion 35 is positioned at the lower end of the concave portion 38 as described above. In this state, as shown in FIG. 8A, the convex portion 35 is fitted into the shallow portion 38a of the concave portion 38, so that the fitting amount h becomes shallow. Thereby, the opening / closing operation force of the manual paper feed tray 28 can be reduced. Conversely, in a state where the duplex unit 18 </ b> A is separated from the main body case 1 and opened, the convex portion 35 is positioned in the deep portion 38 b of the concave portion 38. In this state, as shown in FIG. 8B, the convex portion 35 is fitted into the deep portion 38b of the concave portion 38, so that the fitting amount H becomes deep. Thereby, it is possible to prevent the manual feed tray 28 from being opened carelessly.
[0072]
Also in this embodiment, the convex portion 35 and the concave portion 38 may be replaced with each other by the case 18 and the manual paper feed tray 28.
[0073]
Next, a third embodiment of the present invention will be described with reference to FIG. The same parts as those in the above embodiment are denoted by the same reference numerals, and the description thereof is also omitted. The image forming apparatus according to the present embodiment includes a duplex unit 18 </ b> A attached to the main body case 1 and a manual paper feed unit 34. The case 18 of the duplex unit 18A has an inversion path 20 having an opening 39 formed at the lower end. The length of the reversing path 20 from the vicinity of the reversing roller 22 to the opening 39 is set in accordance with the size of the most frequently used paper, and is shorter than the length of the large-sized paper that is less frequently used. This is to limit the height of the duplex unit 18A and to secure a space for installing the manual sheet feeding unit 34 below the duplex unit 18A.
[0074]
A guide member 40 facing the opening 39 is formed integrally with the paper feed unit 26 of the manual paper feed unit 34. The guide member 40 has a notch 41 that deepens from below the opening 39 toward the main body case 1, and the bottom of the notch 41 has a guide surface 42 that guides the paper protruding from the opening 39. Has been.
[0075]
In such a configuration, a case will be described in which a large-sized sheet whose length in the sheet conveyance direction is longer than the reversing path length is reversed. The paper inversion path is the same as that of the above embodiment, but a large size paper projects from the opening 39. At this time, since the opening 39 opens downward and outward, the paper protrudes downward from the opening 39 and does not protrude to the side of the duplex unit 18A. Accordingly, it is possible to always open the opening 39 without expanding the installation space of the image forming apparatus, and it is possible to invert sheets of various sizes without performing a complicated operation.
[0076]
Then, the leading edge of the paper protruding from the opening 39 goes into the notch 41 arranged opposite to the opening 39. The notch 41 is provided so as to be deeper from the bottom of the opening 39 toward the main body case 1, and the bottom surface is the guide surface 42. Therefore, the sheet that is conveyed to the reversing roller 22 and wraps around the notch 41. Since the leading edge of the sheet is guided in the direction of the main body case 1, sheets of various sizes can be reversed without increasing the installation space of the image forming apparatus. In addition, by providing the guide member 40 integrally with the paper feeding unit 26 of the manual paper feeding unit 34, it is possible to invert sheets of various sizes without increasing the number of parts.
[0077]
Further, the paper stacked on the manual paper feed tray 28 is separated and fed by the paper feed roller 32 and the friction pad 33, so that the mechanism provided for separating the paper can be reduced.
[0078]
  Next, the present inventionReference exampleWill be described with reference to FIGS. The same parts as those in the above embodiment are denoted by the same reference numerals, and the description thereof is also omitted. FIG. 10 is a vertical side view showing a part of the image forming apparatus in which the duplex unit is mounted on the main body case, and FIG. 11 is an exploded perspective view showing a bracket and a guide member that support the case of the duplex unit.
[0079]
  BookReference exampleDoes not have a manual paper feed unit. Therefore, a guide member 43 that is opposed to the opening 39 at the lower end of the reversing path 20 formed in the case 18 is provided. The guide member 43 is formed with a guide surface 44 that guides the paper protruding from the lower end of the reversing path 20 downward when performing double-sided printing using a large size paper that is longer than the length of the reversing path 20. As shown in FIG. 11, the guide surface 44 is formed by upper edges of a plurality of ribs 45 formed integrally with the guide member 43.
[0080]
  In FIG. 11, reference numeral 46 denotes a bracket attached to the double-sided unit attachment surface side of the main body case 1 with screws 47. On the outside of the bent pieces 48 formed on both sides of the bracket 46, a first support shaft 27 for supporting the hinge piece 25 (see FIG. 10) provided on the case 18 so as to be rotatable is erected. Attachment pieces 49 are fixed on both sides of the inner surface of 46. In addition, on both sides of the upper surface of the guide member 43, slits 50 are formed for projecting the hinge pieces 25 provided on both sides of the case 18 to the inside of the guide member 43. Such a guide member 43 is configured to be attached to the attachment piece 49 of the bracket 46 by a screw 51. BookReference exampleThen, the case 18 provided with the reversing path 20, the refeeding path 21, the reversing roller 22, the switching claw 23, the conveying roller 24, etc., the guide member 43, and the bracket 46 having the first support shaft 27 are used on both sides. A unit 18B is configured.
[0081]
In such a configuration, when double-sided printing is performed using a large-size sheet that is longer than the length of the reversing path 20 of the duplex unit 18B, the lower end of the sheet has the opening 39 at the lower end of the reversing path 20 as described above. However, it is possible to guide the protruding paper toward the lower outer side of the case 18 by the guide surface 44 of the guide member 43 and align it. Further, the guide member 43 can function as a decorative member that covers the bracket 46 for rotatably supporting the case 18.
[0082]
Further, when the opening 39 of the duplex unit 18B is arranged near the side opposite to the main body case 1 as in the third embodiment, the paper protruding from the opening 39 is placed on the side of the main body case 1. You may form a guide surface so that it may guide toward. That is, on the paper surface of FIG. 10, by forming the rib so that the height decreases from the right side toward the side surface of the main body case 1, the guide surface is formed by the upper edge of the rib.
[0083]
【The invention's effect】
[0091]
  Claim1The image forming apparatus according to the present invention includes a double-sided unit attached to the double-sided unit attachment side of the main body case in which the image forming unit is built, and is rotatably attached around the first support shaft. The paper reversing path for re-feeding the supplied paper and the second support shaft provided horizontally on the double-side unit mounting side of the main body case are provided to be rotatable about a rotation center. A manual paper feed tray that allows paper to be fed from a manual paper feed port provided on the double-side unit mounting side of the image forming apparatus by rotating, and the double-side unit includes the manual paper feed tray. A storage recess for storing without protruding, and the second support shaft is attached to a portion other than the duplex unit.The rotation angle of the manual feed tray is set to be larger than the rotation angle of the duplex unit, and the support position of the manual feed tray by the second support shaft is the position of the duplex unit by the first support shaft. The first support shaft and the second support shaft are disposed coaxially with respect to the support position.Therefore, it is possible to prevent the manual feed tray from being damaged by a person hitting the manual feed tray.
  Claim2The image forming apparatus according to claim1In the invention described above, an engaging means for fitting the concave portion and the convex portion is provided between the double-side unit and the manual paper feed tray so that the manual paper feed tray can be used even when vibration is applied during movement, for example. Since the two-sided unit is not detached from the two-sided unit, only the manual sheet feeding tray is not inadvertently rotated and protrudes from the two-sided unit. As a result, it is possible to prevent the manual feed tray from being damaged by a person hitting the protruding manual feed tray.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view illustrating a part of an image forming apparatus including a duplex unit according to a first embodiment of the invention.
FIG. 2 is a side view showing a rotating operation of a duplex unit and a manual paper feed tray in the image forming apparatus.
FIG. 3 is a part of a perspective view showing an image forming apparatus including a duplex unit.
FIG. 4 is an enlarged perspective view showing engagement means.
FIG. 5 is an enlarged perspective view of a recess.
FIG. 6 is a horizontal cross-sectional view showing a fitting state between a concave portion and a convex portion.
FIG. 7 is an enlarged perspective view of a recess according to a second embodiment of the present invention.
FIG. 8 is a horizontal cross-sectional view showing a fitting state between a concave portion and a convex portion.
FIG. 9 is a longitudinal side view illustrating a part of an image forming apparatus including a duplex unit according to a third embodiment of the present invention.
FIG. 10 shows the present invention.Reference exampleFIG. 2 is a longitudinal sectional side view showing a part of an image forming apparatus including a duplex unit in FIG.
FIG. 11 is an exploded perspective view showing a bracket and a guide member that support the case of the duplex unit.
FIG. 12 is a longitudinal sectional side view showing a part of an image forming apparatus including a duplex unit as an example of the prior art.
[Explanation of symbols]
    6 Reverse paper exit
    7 Re-feed slot
    8 Manual feed slot
  18 cases
  19 Paper reversing path
  20 Reverse road
  21 Refeed path
  26 Paper feed unit
  27 First spindle
  28 Manual feed tray
  29 Storage recess
  30 Second spindle
  32 Paper feed roller
  33 Friction pad
  34 Manual feed unit
  35 Convex
  36,38 recess
  36a slope
  37 Engagement means
  42 Guide surface
  43 Guide member
  44 Guide surface

Claims (2)

A double-sided unit that is pivotably mounted about a first support shaft provided on the double-sided unit mounting side of the main body case having the built-in image forming unit;
A paper reversing path provided in the duplex unit for refeeding the supplied paper;
A hand provided on the double-sided unit mounting side of the image forming apparatus by rotating about a second support shaft provided horizontally on the double-sided unit mounting side of the main body case. A manual feed tray that allows paper feed from the differential feed slot,
With
The duplex unit includes a storage recess for storing the manual feed tray without protruding,
The second support shaft is attached to a portion other than the duplex unit ,
The rotation angle of the manual feed tray is set larger than the rotation angle of the duplex unit,
The support position of the manual sheet feeding tray by the second support shaft is disposed inside the support position of the duplex unit by the first support shaft,
The first support shaft and the second support shaft are provided coaxially.
Image forming apparatus. Wherein between the duplex unit and the manual paper feed tray, the image forming apparatus according to claim 1, wherein is provided an engaging means for engaging the recesses and projections.

Images