JP3905702B2 - Paper reversing device and image forming apparatus provided with paper reversing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus that switches back a sheet such as a sheet transported from a main transport path in a switchback transport path and reverses it in a branch transport path direction, and in particular reverses the sheet after image formation of an image forming apparatus. The present invention relates to a sheet reversing device and an image forming apparatus including the sheet reversing device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a sheet reversing device for reversing and transporting a sheet, which is provided in an image forming apparatus such as a printer, a copier, or a facsimile, there is one shown in FIGS. As shown in FIG. 5A, the sheet reversing device conveys the image-formed sheet from the main conveyance path K1 to the switchback conveyance path K2, as shown in FIG. 5A, and the switchback conveyance path. It is conveyed to the branch conveyance path K3 by the reversing roller (driving side reversing roller 71h, driven reversing roller 74c) at K2. The main transport path K1, the switchback transport path K2, and the branch transport path K3 constitute a substantially Y-shaped transport path.
[0003]
When a paper sheet is transported from the main transport path K1 to the switchback transport path K2 and is switched from the switchback transport path K2 to the branch transport path K3, high speed processing is supported when a branch claw (not shown) is used. As shown in FIG. 5A, switching is performed using a branch member 72 made of Mylar (manufactured by DuPont).
[0004]
This sheet reversing device is configured to be openable and closable with respect to the fixed-side sheet guide members 71a and 71b and the fixed-side sheet guide members 71a and 71b that are fixed to the main body side and have the main transport path K1, and are fixed to the fixed-side sheet guide. In addition to the members 71a and 71b, a movable-side paper guide member 174 that forms a switchback conveyance path K2 and a branch conveyance path K3 is provided. A branching member 72 is attached to the fixed-side paper guide members 71a and 71b. The branching member 72 blocks the conveyance path with an elastic force between the main conveyance path K1 and the switchback conveyance path K2.
[0005]
As described above, in the sheet reversing device, the branching member 72 is arranged so as to cross the portion transported from the main transporting path K1 to the switchback transporting path K2, so that the branching member 72 does not cross the transporting path due to the sheet transporting force. By elastically deforming, the sheet is conveyed to the switchback conveying path K2.
[0006]
The branching member 72 returns to a free state that crosses the transport path after the sheet has passed. Then, the sheet is conveyed in the reverse direction by the reversing rollers (the driving reversing roller 71h and the driven reversing roller 74c). At this time, since the branch member 72 blocks the main transport path K1, the paper can be branched and transported to the branch transport path K3. According to this paper reversing device, since it is branched using an elastic member instead of the branching claw, it is possible to cope with high-speed processing.
[0007]
In such a paper reversing device, as shown in FIG. 5B, when the paper is clogged in the main transport path K1, the movable side paper guide member 174 is opened to perform the jam processing manually. Can be done.
[0008]
[Problems to be solved by the invention]
However, according to the conventional paper reversing device, when the jam processing is performed, as shown in FIG. 5B, after the movable paper guide member 174 is opened, a part of the jammed paper is exposed. The exposed jammed paper can be grasped by hand and pulled out. At this time, the branching member 72 is plastically deformed toward the outside of the apparatus (movable side paper guide member 174 side) by the paper pulling force, and the branching function is lowered. There was a problem to do.
[0009]
SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet reversing apparatus that can cope with high-speed processing and prevent a decrease in branching function, and an image forming apparatus including the sheet reversing apparatus.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the invention of claim 1 includes a fixed-side sheet guide member having a main conveyance path fixed to the apparatus main body, and a switchback conveyance path and a branch conveyance path together with the fixed-side sheet guide member. A movable side paper guide member configured to be openable and closable with respect to the fixed side paper guide member, and the fixed side paper guide member that blocks between the main transport path and the switchback transport path. A sheet reversing device having a fixed-side sheet guide member, the apparatus main body having a fixed guide for restricting deformation of the elastic member, and the fixed guide being the branch A sheet reversing device, wherein the sheet reversing device is disposed to face the elastic member so as to constitute a part of a conveyance path.
[0011]
According to a second aspect of the present invention, in the paper reversing device according to the first aspect, the fixed guide and the movable paper guide member are comb-shaped when the movable paper guide member is in a closed state. It is characterized by being overlapped.
[0012]
According to a third aspect of the present invention, in the paper reversing device according to the first or second aspect, a paper delivery position between the fixed guide and the movable side paper guide member is arranged in the branch conveyance path. It is characterized by.
[0013]
According to a fourth aspect of the present invention, the fixed sheet guide member having a main conveyance path fixed to the main body of the apparatus, and the fixed sheet guide member and the fixed sheet guide member form a switchback conveyance path and a branch conveyance path. A movable side paper guide member configured to be openable and closable with respect to the side paper guide member; and an elastic member provided on the fixed side paper guide member that closes between the main transport path and the switchback transport path; In the image forming apparatus including the sheet reversing apparatus having the fixing device, the apparatus main body to which the fixed-side sheet guide member is fixed has a fixed guide that restricts deformation of the elastic member, and the fixed guide is the branch An image forming apparatus including a sheet reversing device, wherein the image forming device is disposed to face the elastic member so as to constitute a part of a conveyance path.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 4 is a schematic diagram illustrating the overall configuration of a color image forming apparatus including a sheet reversing device according to an embodiment of the present invention.
[0015]
As shown in FIG. 4, this color image forming apparatus is disposed on the image forming unit 1 disposed obliquely with respect to the vertical direction V and on the downstream side of the image forming unit 1 (the upper end side of the image forming unit 1). A fixing unit 6, a sheet feeding tray 4 that is disposed below the image forming unit 1 and feeds paper toward the image forming units 1 Bk, 1 C, 1 M, and 1 Y of the image forming unit 1, and an image forming unit A transfer unit 2 arranged side by side with respect to the unit 1, a double-sided reversing unit 7 which is a sheet reversing device disposed on the side of the apparatus downstream of the fixing unit 6, and a lower side of the transfer unit 2. A double-sided reversing unit 7 and a double-sided conveying unit 3 for refeeding the transfer paper whose front and back are reversed toward the image forming unit 1 are provided.
[0016]
The image forming units 1Bk, 1C, 1M, and 1Y for each color of the image forming unit 1 are not shown, but an exposure device having a color laser beam emitting device, a drum-shaped photoconductor as a latent image carrier, and a charging charger. And a developing device.
[0017]
In this image forming unit 1, the arrangement direction (transfer sheet conveying direction) of the image forming units 1Bk, 1C, 1M, and 1Y is arranged obliquely with respect to the vertical direction V. With respect to the oblique angle of the image forming unit 1 with respect to the vertical direction, the horizontal length when the image forming unit 1 is disposed obliquely is substantially equal to the length of the paper feed tray 4 in the horizontal direction (left-right direction in the figure). An angle is most desirable for space saving.
[0018]
The transfer unit 2 includes a transfer charger 22 that transfers a visible image onto transfer paper, and a transfer belt 21 that conveys the transfer paper.
The fixing unit 6 includes a fixing roller 61 for fixing the visible image transferred on the transfer paper. Although the fixing roller 61 is shown in the figure, a fixing belt may be used instead of the fixing roller.
[0019]
The double-sided reflection unit 7 has a function of discharging the transfer paper having a visible image fixed on one side thereof 8 with face-up, and a double-sided conveyance unit 3 for forming a visible image on the other surface of the transfer paper reversed by a reversing roller. And a function of branching the transfer sheet reversed by the reversing roller and transporting it to the post-processing apparatus (not shown) by the transporting roller. The post-processing device performs sorting, stapling, and the like.
[0020]
The double-sided conveyance unit 3 has a function of re-feeding the image forming unit 1 in a state where the transfer paper having a visible image fixed on one side thereof is reversed in cooperation with the double-side reversing unit 7.
[0021]
The paper feed tray 4 is disposed below the duplex conveyance unit 3 and is configured such that the sheet paper 41 is taken out from the tray one by one by a pickup roller 42, a paper feed roller 43, and a separation roller 44.
[0022]
FIGS. 1A and 1B are diagrams showing a main part of a sheet reversing device according to an embodiment of the present invention. FIG. 1A shows a movable sheet guide member in a closed state (normal use state), and FIG. The guide member is in an open state (jam processing state). In FIG. 1, the sheet conveyance path from the switchback conveyance path K2 toward the duplex reversing unit 3 is omitted.
[0023]
As shown in FIG. 1 (A), the paper reversing device has fixed-side paper guide members 71a and 71b fixed to the paper reversing device main body side, and a lower end portion of the paper reversing device with respect to the fixed-side paper guide members 71a and 71b. A movable-side paper guide member 74 that rotates around the moving shaft 76 (see FIG. 4) and opens and closes the switchback conveyance path K2 and the branch conveyance path K3 is provided.
[0024]
The fixed-side sheet guide member 71a and the fixed-side sheet guide member 71b form a main transport path K1. Further, a branch conveyance path K3 is formed by the movable side paper guide member 74 and the fixed side paper guide member 71a. Further, a switchback conveyance path K2 is formed by the movable side paper guide member 74 and the fixed side paper guide member 71b.
[0025]
The fixed-side paper guide member 71a includes a branching member mounting portion for mounting a driven-side reversing roller 71c that projects into the main transport path K1, a discharge roller 71e that projects into the branch transport path K3, and a branching member 72 that is an elastic member. 71f. The branch member 72 is made of a polyester film in the present embodiment.
[0026]
The fixed-side paper guide member 71b protrudes into the main transport path K1 so as to face the driven-side reverse roller 71c, and cooperates with the driven-side reverse roller 71c to drive the paper in both forward and reverse directions. , A recess 71g that escapes the leading end 72a of the branching member 72, and a driven reverse roller 74c that protrudes into the switchback feeding path K2 and cooperates with the driven reverse roller 74c to convey the paper in both forward and reverse directions. And a side reversing roller 71h.
[0027]
The movable sheet guide member 74 projects into the branch conveyance path K3 so as to face the discharge roller 71e, and cooperates with the discharge roller 71e to convey the sheet in the branch conveyance direction A3, and a sheet delivery position 75. The rib 74b that overlaps with the fixed guide 73 in a comb-tooth shape, and protrudes into the switchback conveyance path K2 so as to face the driving-side reversing roller 71h. And a driven reversing roller 74c for conveying in both directions.
[0028]
FIG. 2 is a diagram illustrating a sheet delivery portion between the movable sheet guide member and the fixed guide.
As shown in FIG. 2, the fixed guide 73 is formed with a notch 73 a that opens toward the movable paper guide member 74, and the movable paper guide member 74 projects to face the notch 73 a of the fixed guide 73. Ribs 74b are formed. When the movable side paper guide member 74 is in the closed state (FIGS. 1A and 2), the fixed guide 73 and the movable side paper guide are inserted by inserting at least a part of the rib 74b into the notch 73a. The member 74 overlaps in a comb-tooth shape. That is, the fixed guide 73 and the movable paper guide member 74 are arranged so that the pair of comb teeth alternately cross each other via the notch 73a and the rib 74b.
[0029]
Since the fixed guide 73 is made of a metal such as iron, it is possible to obtain sufficient strength against mechanical deformation that acts when taking out jammed paper and thermal deformation due to the paper immediately after fixing.
[0030]
FIG. 3 is a view showing a fixed guide taken along line AA in FIG.
As shown in FIG. 3, the fixed guide 73 includes a notch 73a into which the above-described rib 74b is inserted, attachment plates 73b provided at both ends, and a fixed-side sheet guide member 71a via the attachment plates 73b. And an attachment shaft 73c attached to the main body fixing side such as a side plate not to be provided.
[0031]
Next, the operation of the sheet reversing device described with reference to FIGS. 1 to 3 will be described.
The transfer sheet on which the toner image is fixed by the fixing unit 6 and is transported downward along the main transport direction A1 passes through the branch member 72, and then the reflection sensor includes the lower end position of the transfer sheet on the fixed-side sheet guide member 71b. , And reversely rotates the drive-side reversing roller 71h to move the transfer paper upward in the switchback conveyance direction A2. At this time, the branching member 72 is restored from the elastic deformation and the tip 72a is disposed in the recess 71g. Therefore, the branching conveyance direction A3 along the branching conveyance path K3 between the branching member 72 and the fixed guide 73. And is supplied to a post-processing apparatus (not shown).
[0032]
In such paper reversal, when a jam occurs in the main transport path K1, the movable paper guide member 74 can be opened to take out the jammed paper as shown in FIG. At this time, as shown in FIG. 1B, since the branching member 72 is regulated within the elastic limit by the fixed guide 73, after the jammed paper is taken out, the branching member 72 is quickly moved back by the elastic force of the branching member. , That is, the position where the tip 72a is in the recess 71g. Therefore, the branching function is not deteriorated by removing the jammed paper.
[0033]
Further, since the movable paper guide member 74 that can be opened and the fixed guide 73 that faces the branching member 72 that is fixed to the apparatus main body overlap in a comb shape, the movable paper guide member 74 and the fixed guide are overlapped. 73, it is possible to improve the sheet conveyance performance at the connection portion 73, that is, the sheet transfer position 75.
[0034]
Further, the sheet delivery position 75 is located on the fixed portion side with respect to the branch member tip 72a, that is, the delivery position 75 is located in the branch conveyance path K3. To improve the conveyance performance, improve the function of regulating the deformation of the branching member 72 by minimizing the size of the fixed portion guide 73, and the visibility and processing of jammed paper. Can do.
In addition, this invention is not limited to the said Example. That is, various modifications can be made without departing from the scope of the present invention.
[0035]
【The invention's effect】
As described above, according to the first aspect of the present invention, the branching member is made of an elastic member to enable high-speed processing, and the branching function is reduced due to deformation of the branching member due to jamming or the like. Therefore, it is possible to provide a sheet reversing device that can prevent the above.
[0036]
According to the invention of claim 2, the guide portion provided on the fixed side and the movable paper guide member are configured to overlap in a comb-tooth shape when the movable paper guide member is in the closed state. Therefore, there is an effect that the sheet transportability is high in the connecting portion between the guide portion and the movable guide member.
[0037]
According to the invention of claim 3, since the paper delivery position is arranged in the branch conveyance path, the conveyance direction is improved by making the conveyance direction of the sheet one-way in the connecting portion between the guide portion and the movable side guide member. In addition, the size of the guide portion can be minimized, and the visibility and processability of jammed paper can be improved.
[0038]
According to the invention of claim 4, the branch member is made of an elastic member to enable high-speed processing, and it is possible to prevent deterioration of the branch function that occurs due to deformation of the branch member due to jam processing or the like. It is possible to provide an image forming apparatus provided with a paper reversing device capable of performing the above.
[Brief description of the drawings]
1A and 1B are diagrams illustrating a main part of a sheet reversing device according to an embodiment of the present invention, in which FIG. 1A is a movable sheet guide member in a closed state (normal use state), and FIG. The paper guide member is in an open state (jam processing state).
FIG. 2 is a diagram illustrating a paper delivery portion between a movable paper guide member and a fixed guide.
FIG. 3 is a view showing a fixed guide taken along line AA in FIG. 2;
FIG. 4 is a schematic diagram illustrating an overall configuration of a color image forming apparatus including a sheet reversing device according to an embodiment of the present invention.
5A and 5B are diagrams showing main parts of a conventional paper reversing device, in which FIG. 5A shows a movable paper guide member in a closed state (normal use state), and FIG. 5B shows a movable paper guide member in an open state. This is the state of the jam processing.
[Explanation of symbols]
71a, 71b Fixed-side paper guide member 71f Branch member mounting portion 71h Drive-side reversing roller 72 Branch member (elastic member)
72a Branch member tip 73 Fixed guide (guide part)
73a Notch 73b Mounting plate 73c Mounting shaft 74 Movable paper guide member 74b Rib 74c Driven reversing roller 75 Paper delivery position A1 Main transport direction A2 Switchback transport direction A3 Branch transport direction K1 Main transport path K2 Switchback transport path K3 Branch Transport path P Paper

Claims (4)

A fixed-side paper guide member having a main conveyance path fixed to the apparatus main body;
A movable side paper guide member configured to be openable and closable with respect to the fixed side paper guide member, which forms a switchback conveyance path and a branch conveyance path together with the fixed side paper guide member;
An elastic member provided on the fixed-side paper guide member that blocks between the main transport path and the switchback transport path;
In the paper reversing device having
The apparatus main body to which the fixed side paper guide member is fixed has a fixed guide for restricting deformation of the elastic member, and
The sheet reversing device , wherein the fixed guide is disposed to face the elastic member so as to constitute a part of the branch conveyance path . Said fixed guide and said movable sheet guide member, when the movable-side sheet guide member is in the closed state, the sheet reversing apparatus according to claim 1, characterized in that the overlapping comb-like. It said fixed guide and the paper delivery position between the movable-side sheet guide member, the sheet reversing apparatus according to claim 1 or 2, characterized in that it is disposed in said branched transport path. A fixed-side paper guide member having a main conveyance path fixed to the apparatus main body;
A movable side paper guide member configured to be openable and closable with respect to the fixed side paper guide member, which forms a switchback conveyance path and a branch conveyance path together with the fixed side paper guide member;
An elastic member provided on the fixed-side paper guide member that blocks between the main transport path and the switchback transport path;
In an image forming apparatus provided with a sheet reversing device having
The apparatus main body to which the fixed side paper guide member is fixed has a fixed guide for restricting deformation of the elastic member, and
An image forming apparatus comprising a sheet reversing device, wherein the fixed guide is disposed to face the elastic member so as to constitute a part of the branch conveyance path .

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