JP2011121749A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress any alignment deviation of a medium passing through a second conveying passage. <P>SOLUTION: An image forming device (U) includes: second conveying passages (SH4-SH6, SH1) which are connected to a first conveying passage (SH1) and through which a medium (S) is passed when the medium (S) with an image being formed on its one side is conveyed again to image forming units ((UG+GG) to (UK+GK), T1g to T1k+T2+B); aligning units (Sha+Rc+SGa) provided on the first conveying passage (SH1) to align the medium (S); and adjustment units (Sk+81+91) provided on the second conveying passages (SH4 to SH6, SH1) to adjust the position in the width direction of the medium (S) to be conveyed to the aligning units (Sha+Rc+SGa). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  Conventionally, in an image forming apparatus such as an electrophotographic copying machine or printer, as a technique for correcting the inclination of a medium conveyed to an image recording area on which an image is recorded, for example, described in Patent Documents 1 and 2 below. The technology is known.

Japanese Patent Laid-Open No. 2004-28495 as Patent Document 1 discloses a skew roll (321 to 323) for transporting a sheet (S) transported from a sheet supply unit (22) and the skew roll (321 to 323). ) Describes a transport unit (340) having a side guide (310) that aligns the side edges of the sheet (S) transported by the above-described method.
In Patent Document 1, a first adjustment mechanism (350) having a guide motor (353), a drive transmission system (354), a home sensor (361), and the like is controlled to move the side guide (310) downstream in the sheet conveying direction. In addition to rotating around the pivot point (351) at the end, the second adjustment mechanism (370) having a unit motor (373), drive transmission system (374), home sensor (386), etc. is controlled. In addition, the transport unit (340) itself is also described with a technique of rotating the swing fulcrum (371) at the downstream end in the sheet transport direction as the center of rotation.

Japanese Patent Application Laid-Open No. 2005-314097 as Patent Document 2 describes a technique regarding a skew correction unit (Us) that corrects a side skew of the recording paper (S) conveyed from the paper feeding device (U2). ing. In Patent Document 2, by rotating a manual position adjustment bar (31) of a skew correction unit (Us), a bevel gear (34, 37), an intermediate gear (G1 to G5), and a position adjustment cam (52). In addition, a technique is described in which the skew correction unit (Us) is rotationally moved about the pivot (4) via the cam follower (17) or the like.
That is, in Patent Documents 1 and 2, when the paper transport path until the paper is carried in is long, the skew correction unit itself, which has a possibility that the passing position in the width direction of the paper may be largely shifted, is rotated to rotate the paper. A technique for correcting side skew is described.

Japanese Unexamined Patent Publication No. 2004-284795 ("0029" to "0036", "0043", FIGS. 1 to 13) JP-A-2005-314097 ("0029" to "0036", "0059", FIGS. 1 to 12)

  An object of the present invention is to suppress misalignment of a medium that has passed through the second transport path.

In order to solve the technical problem, an image forming apparatus according to claim 1 is provided.
An image forming unit for forming an image on a medium;
A first conveyance path through which the medium conveyed to the image forming unit passes;
A second transport path that is coupled to the first transport path and through which the medium passes when the medium on which an image is formed on one side by the image forming section is transported to the image forming section again.
An alignment unit provided on the first conveyance path for aligning the medium conveyed to the image forming unit;
An adjustment unit that is provided on the second conveyance path and adjusts the position in the width direction perpendicular to the conveyance direction of the medium conveyed to the alignment unit;
It is provided with.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect,
An image forming apparatus main body having the respective transport paths;
The alignment unit having the first unit for conveying the medium carried in from the carry-in unit to the downstream side in the conveyance direction;
The adjusting unit having a second unit for conveying the medium to the first unit;
A frame of the second unit that rotatably supports a medium conveying member that conveys the medium;
A supported portion provided in the frame;
A support portion provided in the image forming apparatus main body and supporting the supported portion from the width direction;
When the second unit is configured to be detachable between the supported part and the support part and is mounted between the supported part and the support part, the second unit is moved in the width direction with respect to the transport direction. And an adjustment member that adjusts the position in the width direction of the medium conveyed by the medium conveyance member, and a carry-in range in which a carry-in position at which the medium is carried into the carry-in unit is set in advance The adjustment member for inclining the second unit so as to be inside the carry-in range when the outer side is outside,
It is provided with.

According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect,
The first unit having a side edge aligning member that aligns the widthwise side edges of the medium;
The second transport path having a reversing path for reversing the front and back of the medium on which the image is recorded on one side through an image recording area in which an image is recorded on the medium and bringing the medium into the loading section;
The carry-in position in which the width direction side end of the medium on the side end alignment member side is set at a position away from the side end alignment member in the width direction;
It is provided with.

According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects,
The frame length, which is the length of the frame in the transport direction, is set to be equal to or greater than a maximum medium length which is a preset maximum value of the length of the medium in the transport direction.

According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects,
A drive source provided on the frame for rotating the medium conveying member;
It is provided with.

According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects,
A housing part that is provided in the frame body and that accommodates the adjustment member removed from between the supported part and the support part when the second unit is not inclined;
It is provided with.

According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the first to sixth aspects,
An upstream gap formed between the upstream end of the second unit in the transport direction and the second transport path upstream of the second unit in the transport direction;
A downstream gap formed between the downstream end of the second unit in the transport direction and the second transport path on the downstream side of the second unit in the transport direction;
It is provided with.

According to the first aspect of the present invention, it is possible to suppress misalignment of the medium that has passed through the second transport path as compared with the case where this configuration is not provided.
According to the second aspect of the present invention, the shift in the width direction of the medium can be reduced with a simple configuration as compared with the case where the second unit is not inclined.
According to the third aspect of the present invention, it is possible to accurately correct the inclination of the medium and to correct the inclination of the side edge aligning member as compared with the case where the medium is not carried into the carry-in position away from the side end aligning member in the width direction. It is possible to reduce clogging of the medium that comes into contact with the front end of the medium reversed to the upstream end in the transport direction.

  According to the fourth aspect of the present invention, it is possible to secure a period during which the entire medium is accommodated in the second unit, and the medium is transported in a direction to cancel the displacement in the width direction of the medium only by the medium transport member inside the second unit. Compared to the configuration in which the medium is conveyed across the conveyance path inside and outside the second unit, the medium can be easily conveyed in a direction that cancels the deviation in the width direction of the medium, and the medium is twisted or wrinkled. Can be reduced.

According to invention of Claim 5, the 2nd unit which has a drive source can be inclined.
According to the sixth aspect of the present invention, the adjustment member can be accommodated in the second unit even when the second unit is not inclined.
According to the seventh aspect of the present invention, it is possible to reduce the fact that the inclination of the second unit is prevented as compared with a configuration in which each gap is not formed.

FIG. 1 is a diagram illustrating the entire printer according to the first embodiment. FIG. 2 is an explanatory diagram of an image forming apparatus main body of the printer according to the first exemplary embodiment. FIG. 3 is an explanatory diagram of the interface module and the stacker device of the printer according to the first embodiment. FIG. 4 is an enlarged explanatory view of the main part of the image forming apparatus main body of Example 1, and is an explanatory view of the visible image forming apparatus and the belt module. FIG. 5 is an explanatory diagram of the medium transport unit according to the first embodiment, FIG. 5A is an enlarged perspective view of the medium transport unit, and FIG. 5B is an explanatory diagram of opening and closing of the medium transport unit as viewed from the right. FIG. 6 is an explanatory diagram of a state in which the medium transport unit is looked up diagonally to the right from the position on the diagonally lower left side. FIG. 7 is a perspective enlarged explanatory view of the handle and the latch according to the first embodiment. FIG. 8 is an enlarged explanatory view of the main body fixing bracket of the first embodiment. FIG. 9 is an enlarged explanatory view of the spacer of the first embodiment. FIG. 10 is an explanatory diagram of a state in which a spacer is mounted between the right supported portion and the right frame support portion from the state of FIG. FIG. 11 is an enlarged explanatory view of a main part in a state in which the medium transport unit in which the spacer is mounted between the right supported part and the right frame support part is viewed from below the lower chute. FIG. 12 is an explanatory view of the inclination of the medium transport unit, and FIG. 12A is an illustration of a state in which the medium transport unit in which a spacer is mounted between the right supported part and the right frame support part is looked down from above. FIG. 12B is an explanatory diagram of a state in which the medium transport unit in which a spacer is mounted between the left supported portion and the left frame supporting portion is viewed from above. FIG. 13 is an explanatory diagram of the carry-in position of the skew correction unit according to the first embodiment.

Next, specific examples of embodiments of the present invention (hereinafter referred to as examples) will be described with reference to the drawings, but the present invention is not limited to the following examples.
In order to facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left-right direction is the Y-axis direction, the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The directions indicated by Z and -Z or the indicated side are defined as front, rear, right, left, upper, lower, or front, rear, right, left, upper, and lower, respectively.
In the figure, “•” in “○” means an arrow pointing from the back of the page to the front, and “×” in “○” is the front of the page. It means an arrow pointing from the back to the back.
In the following description using the drawings, illustrations other than members necessary for the description are omitted as appropriate for easy understanding.

(Description of Printer U of First Embodiment)
FIG. 1 is a diagram illustrating the entire printer according to the first embodiment.
FIG. 2 is an explanatory diagram of an image forming apparatus main body of the printer according to the first exemplary embodiment.
FIG. 3 is an explanatory diagram of the interface module and the stacker device of the printer according to the first embodiment.
1 to 3, a printer U as an example of an image forming apparatus is disposed on the downstream side of the image forming apparatus main body U1 and the medium discharging direction of the image forming apparatus main body U1, and an operation unit UI for operating the printer U. And an interface module U2 as an example of a bend removing device, and a stacker device U3 as an example of a medium discharge stacking device disposed downstream of the interface module U2 in the medium discharge direction.

(Description of Image Forming Apparatus Main Body U1 of Embodiment 1)
In FIG. 2, the image forming apparatus main body U1 includes an image recording unit U1a and a fixing / reversing unit U1b, and a main body side control unit C1 for controlling the image forming apparatus main body U1 and an external information transmitting device COM. An information transmission / reception device (not shown) that receives image information transmitted from the computer via the interface module U2, a latent image forming device drive circuit D, a power supply circuit E, and the like controlled by the main body control unit C1.
The latent image forming device driving circuit D of the image recording unit U1a, the operation of which is controlled by the main body side control unit C1, is based on the image information transmitted through the interface module U2, and is G: green, O: orange, Y : Yellow, M: Magenta, C: Cyan, K: Black image information is generated, and drive signals corresponding to the image information are set in advance at the preset timings for the latent image forming devices ROSg, ROSo, ROSi, ROSm of the respective colors G to K. , ROSc, and ROSk.

FIG. 4 is an enlarged explanatory view of the main part of the image forming apparatus main body of Example 1, and is an explanatory view of the visible image forming apparatus and the belt module.
2 and 4, below the latent image forming devices ROSg to ROSk for the respective colors G to K, image holding unit units UG, UO, UY, UM, UC, UK for the respective colors G to K, and a developing device are provided. As an example, developing devices GG, GO, GY, GM, GC, GK for the respective colors G to K are detachably mounted.
The black K image carrier unit UK includes a photosensitive drum Pk as an example of an image carrier, a charger CCk, and a drum cleaner CLk as an example of an image carrier cleaner. Further, a developing roll R0k as an example of a developing member of the black K developing device GK is disposed adjacent to the right side of the photosensitive drum Pk.

The image holding units UG to UC for the other colors G to C are also provided with the photosensitive drums Pg, Po, Py, Pm, and Pc, chargers CCg, CCo, CCy, CCm, CCc, drum cleaners CLg, CLo, and CLy. , CLm, CLc. Further, on the right side of the photosensitive drums Pg to Pc for the other colors G to C, developing rolls R0g, R0o, R0y, R0m as examples of developing members of the developing units GG to GC for the other colors G to C are provided. , R0c are arranged adjacent to each other.
In Example 1, the K photosensitive drum Pk, which is frequently used and has a lot of surface wear, is configured to have a larger diameter than the photosensitive drums Pg to Pc of other colors, and is capable of high-speed rotation and has a long service life. It is planned.
Visible image forming devices (UG + GG), (UO + GO), (UY + GY), (UM + GM), (UC + GC), and (UK + GK) are configured by the image carrier units UG to UK and the developing units GG to GK. Is done.

2 and 4, the photosensitive drums Pg to Pk are uniformly charged by the chargers CCg to CCk, respectively, and then are examples of latent image writing light output from the latent image forming devices ROSg to ROSk. An electrostatic latent image is formed on the surface by the laser beams Lg, Lo, Ly, Lm, Lc, and Lk. The electrostatic latent images on the surfaces of the photosensitive drums Pg to Pk are made of G: green, O: orange, Y: yellow, M: magenta, C: cyan, K: black by the developers in the developing units GG to GK. An image and a toner image as an example of a visible image are developed.
When the developer in the developing devices Gg to Gk is consumed by the development, the developer is replenished to the developing devices Gg to Gk from the developer replenishing device U1c provided on the upper part of the image forming apparatus main body U1. In the developer supply device U1c, toner cartridges Kg, Ko, Ky, Km, Kc, Kk as an example of a developer supply container are supported so as to be detachable and replaceable.

2 and 4, the toner images on the surfaces of the photosensitive drums Pg to Pk are primary transfer rolls T1g as an example of a primary transfer member in the primary transfer regions Q3g, Q3o, Q3y, Q3m, Q3c, and Q3k. , T1o, T1y, T1m, T1c, and T1k are sequentially transferred onto an intermediate transfer belt B as an example of an intermediate transfer member, and a multicolor image, so-called color image, is formed on the intermediate transfer belt B. The color image formed on the intermediate transfer belt B is conveyed to a secondary transfer area Q4 as an example of an image recording area.
In the case of only black image data, only the black K photosensitive drum Pk and the developing device GK are used, and only the black K toner image is formed. In addition, when four-color printing of Y, M, C, and K, or two-color and three-color printing according to user settings, etc. are performed, the corresponding photosensitive drums Pg to Pk and developing units GG to GK is used.
After the primary transfer, the residual toner on the surface of the photosensitive drums Pg to Pk is cleaned by the drum cleaners CLg to CLk for the photosensitive drum and recharged by the chargers CCg to CCk.

1, 2, and 4, below each of the photosensitive drums Pg to Pk, a belt module BM as an example of an intermediate transfer device is in a raised position where it contacts the lower surface of each of the photosensitive drums Pg to Pk. It is supported so that it can be moved up and down between a lowering position separated downward from the lower surface.
The belt module BM has the intermediate transfer belt B. The intermediate transfer belt B is rotationally driven in the direction of the arrow Ya by a belt drive roll Rd as an example of an intermediate transfer body drive member that supports the intermediate transfer belt B from the back surface, and tension is applied by a tension roll Rt as an example of a tension applying member. Is attached and stretched. The intermediate transfer belt B includes a walking roll Rw as an example of a meandering prevention member for preventing meandering of the intermediate transfer belt B, a plurality of idler rolls Rf as an example of a driven member, and an example of a secondary transfer counter member. The back side is supported by the backup roll T2a.

  In FIG. 4, in Example 1, the upstream side of the G-color primary transfer roll T <b> 1 g in the direction of the arrow Ya is perpendicular to the direction of the arrow Ya and is intermediate to the photosensitive drum Pg. A first retracting roll R1 as an example of an intermediate transfer member support member for contact / separation supported so as to be movable in a contact / separation direction that is a direction in which the transfer belt B is contacted / separated is disposed. Further, on the downstream side in the arrow Ya direction of each O-color primary transfer roll T1o and on the upstream side in the arrow Ya direction of each Y-color primary transfer roll T1y, the contact configured similarly to the first retract roll R1 is provided. A second retract roll R2 and a third retract roll R3, which are examples of the separating intermediate transfer member support member, are arranged side by side. Further, on the downstream side in the arrow Ya direction of each primary transfer roll T1c for C color and on the upstream side in the arrow Ya direction for each primary transfer roll T1k for K color, the contact configured similarly to the first retract roll R1 is provided. A fourth retract roll R4 as an example of a separating intermediate transfer member support member is disposed. Further, a fifth retract roll as an example of the intermediate transfer member support member for contact / separation configured similarly to the first retract roll R1 is provided downstream of the K primary transfer rolls T1k in the direction of the arrow Ya. R5 is arranged.

In FIG. 4, a plate-shaped discharge sheet metal JB as an example of a charge removal member for removing charges on the back surface of the intermediate transfer belt B is disposed on the downstream side in the direction of arrow Ya of each of the primary transfer rolls T1g to T1k. ing. The neutralizing sheet metal JB of Example 1 is disposed in a non-contact manner with the intermediate transfer belt B, and can be disposed, for example, at a position 2 mm away from the back surface of the intermediate transfer belt B.
Belt support rolls Rd, Rt, Rw, Rf as an example of an intermediate transfer member support member that rotatably supports the intermediate transfer belt B from the back surface by the rolls Rd, Rt, Rw, Rf, T2a, R1 to R5. , T2a, R1 to R5 are configured.
Further, the belt module according to the first embodiment includes the intermediate transfer belt B, the belt support rolls Rd, Rt, Rw, Rf, T2a, R1 to R5, the primary transfer rolls T1g to T1k, the static elimination sheet metal JB, and the like. A BM is configured.

  A secondary transfer unit Ut is disposed below the backup roll T2a. The secondary transfer unit Ut is provided with a secondary transfer roll T2b as an example of a secondary transfer member. The secondary transfer roll T2b is disposed so as to be in contact with or separated from the backup roll T2a with the intermediate transfer belt B interposed therebetween. The secondary transfer area Q4 is formed by the area where the secondary transfer roll T2b is in pressure contact with the intermediate transfer belt B. Is formed. Further, a contact roll T2c as an example of a contact conduction member is in contact with the backup roll T2a. A secondary transfer voltage having the same polarity as the charging polarity of the developer is applied to the contact roll T2c at a preset time from the power supply circuit E controlled by the main body side controller C1.

The backup roll T2a, the secondary transfer roll T2b, and the contact roll T2c constitute the secondary transfer device T2 of Example 1. The primary transfer rolls T1g to T1k, the intermediate transfer belt B, and the secondary transfer unit T2 constitute a transfer device T1g to T1k + T2 + B according to the first embodiment.
The visible image forming devices (UG + GG) to (UK + GK), the transfer devices T1g to T1k + T2 + B, and the like constitute the image forming units (UG + GG) to (UK + GK) and T1g to T1k + T2 + B of Example 1.

Below the belt module BM, paper feed trays TR1 and TR2 are provided as an example of a medium storage unit that stores a recording sheet S as an example of a medium. The recording sheets S accommodated in the paper feed trays TR1 and TR2 are taken out from the paper feed trays TR1 and TR2 by a pick-up roll Rp as an example of a medium take-out member, and one sheet at a time by a paper roll Rs as an example of a curling member. It is separated and transported to the medium supply path SH1 as an example of the first transport path.
The recording sheet S conveyed to the medium supply path SH1 is conveyed to a deburring device Bt as an example of a medium unnecessary part removing device by a conveying roll Ra as an example of a medium conveying member. The deburring device Bt includes a pressure roll Bt1 as an example of a pressure member, and a counter roll Bt2 that is pressed against and contacts the pressure roll Bt1 as an example of a counter member. The recording sheet S is pressed and sandwiched by the pressure roll Bt1 and the counter roll Bt2, and is removed, and unnecessary portions at the end of the recording sheet S are removed, so-called deburring of the recording sheet S is performed.

The deburred recording sheet S is conveyed to the double feed detection device Jk. The double feed detection device Jk detects whether or not the recording sheet S is conveyed without being rolled by the separation roll Rs, and a plurality of recording sheets S are conveyed in an overlapping manner, that is, whether or not multiple recording is performed. To do.
Note that a manual feed path SH0 is connected to the upstream side in the medium conveyance direction as an example of the conveyance direction of the multifeed detection device Jk, and the recording sheet S supplied from a manual medium supply unit (not shown) is also double-fed. The double feed is detected by the detection device Jk.
The recording sheet S in which it is detected whether or not it is double fed is an example of a first unit, and is conveyed to a skew correction unit Sh as an example of an inclination posture correction unit. The skew correction unit Sh includes a cross roll Rc as an example of a skew roll, and a side guide SGa as an example of a side edge aligning member shown in FIG. 13 which will be described later, disposed at the front end of the skew correction unit Sh. Have. In the first embodiment, the recording sheet S is brought into contact with the front side guide SGa by the cross-trol Rc to correct the inclination posture of the recording sheet S, so-called skew.
The recording sheet S whose skew has been corrected is conveyed to a registration roll Rr as an example of a conveyance timing adjusting member.

The recording sheet S conveyed to the registration roll Rr passes through the pre-transfer medium guide member SG1 in accordance with the time when the multi-color image or single-color image on the intermediate transfer belt B is conveyed to the secondary transfer region Q4. It is conveyed to the next transfer area Q4.
The multicolor image on the intermediate transfer belt B is transferred to the recording sheet S by the secondary transfer device T2 when passing through the secondary transfer region Q4. In the case of a multi-color image, the toner images primarily transferred onto the surface of the intermediate transfer belt B are secondarily transferred onto the recording sheet S at once. The intermediate transfer belt B after the secondary transfer is cleaned by a belt cleaner CLb as an example of an intermediate transfer body cleaner.

1 to 3, the recording sheet S on which the unfixed visible image is secondarily transferred passes through the post-transfer medium guide member SG <b> 2, and is fixed to the fixing reversal unit by a conveyance belt HB as an example of a medium conveyance member before fixing. It is conveyed to the fixing device F provided in U1b.
In FIG. 3, the fixing device F includes a heating roll Fh as an example of a heat fixing member and a pressure roll Fp as an example of a pressure fixing member. The recording sheet S is conveyed to a fixing region Q5 where a pair of fixing members Fh and Fp are in contact with each other under pressure. The unfixed visible image on the recording sheet S is heated and fixed by the fixing device F when passing through the fixing region Q5.

In FIG. 2, the heat-fixed recording sheet S is conveyed to the cooling device Co. The cooling device Co rotates as an example of an endless belt-shaped upper transport member, and is opposed to the upper transport belt Co1 as an example of an endless belt-shaped upper transport belt Co1 and an endless belt-shaped lower transport member. And a lower conveyance belt Co2 stretched in a possible manner. A heat sink Co3 as an example of a heat radiating member is disposed inside the upper transport belt Co1, and the heat of the upper transport belt Co1 is taken away and released to the outside by a blower member (not shown).
As a result, when the recording sheet S heated by the fixing device F is sandwiched and transported between the pair of transport belts Co1 and Co2, the heat of the recording sheet S is taken away by the transport belts Co1 and Co2, and the recording is performed. The sheet S is cooled.

The cooled recording sheet S is conveyed to a main body decurling device Hd as an example of a main body side curvature removing device. The main body decurling device Hd, as an example of the first bend removal member, sandwiches the recording sheet S between a large-diameter upper flexible cylindrical member and a small-diameter lower rigid cylindrical member, so that the recording sheet S is curved, so-called curl. Has a roll-type decal member Hd1 for removing water. On the downstream side of the roll-type decal member Hd1 in the medium conveying direction, as an example of the second bend removing member, the recording sheet S is sandwiched between a stretched endless belt-like member and a cylindrical member that contacts the endless belt-like member from above. A belt-type decurling member Hd2 for removing curl is disposed.
In the main body decurling device Hd, after the curl is removed by the roll type decurling member Hd1 and the belt type decurling member Hd2, the recording sheet S is discharged from the main body decurling device Hd by the discharge member Hd3.

A transport path switching member GT1 is provided on the downstream side of the main body decurling apparatus Hd in the medium transport direction. The transport path switching member GT1 selectively switches the transport destination of the recording sheet S transported through the main body processing path SH2 as an example of the medium transport path to either the main body discharge path SH3 or the medium inversion path SH4.
The recording sheet S conveyed to the main body discharge path SH3 is in a so-called face-up state with the image recording surface on which the image is recorded facing upward by a main body discharge roll Rh as an example of a main body discharge member. It is transferred to the interface module U2.

  When the image recording surface of the recording sheet S is reversed from the upward state to the downward state and conveyed to the interface module U2 in a so-called face-down state, the recording sheet S conveyed from the main body processing path SH2 It is guided to the medium reversing path SH4 by the path switching member GT1. Then, when the rear end of the recording sheet S in the medium conveyance direction passes through the conveyance path switching member GT2 provided at the branch portion of the medium reversal path SH4, the reversing roll Rb capable of forward and reverse rotation as an example of the reversal conveyance member is used. Then, the recording sheet S is reversely conveyed and so-called switch back is performed. Then, the recording sheet S that has been switched back is guided to the main body discharge path SH3 by the conveyance path switching member GT2, and the image recording surface of the recording sheet S is inverted from the upward state to the downward state, and is transferred to the interface module U2. Be transported.

  When images are recorded on both sides of the recording sheet S, the recording sheet S on which an image has been recorded on one side conveyed from the main body processing path SH2 is guided to the medium reversing path SH4 by the conveyance path switching member GT1. Then, the recording sheet S is conveyed to the medium circulation path SH5 having the medium conveyance unit Sk as an example of the second unit by the reversing roll Rb of the medium reversing path SH4, and is conveyed toward the double-sided recording reversing path SH6. . When the rear end of the recording sheet S in the medium conveyance direction passes through the conveyance path switching member GT3 provided at the connection between the medium circulation path SH5 and the double-sided recording reversal path SH6, the recording sheet S is switched back. The recording sheet S that has been switched back is guided to the medium supply path SH1 by the transport path switching member GT3 and is retransmitted to the medium supply path SH1.

As a result, the recording sheet S on which the image is recorded on one side is conveyed through the medium supply path SH1 in a state where the front and back sides are reversed, and is retransmitted to the secondary transfer region Q4, on the other side where no image is recorded. Also images are recorded.
The reversing paths (SH4 to SH6) of the first embodiment are configured by the symbols SH4 to SH6 and the like, and the second transport path of the first embodiment is configured by the reversing paths (SH4 to SH6) and the medium supply path SH1. Has been. Further, the conveyance paths (SH1 to SH6) of the first embodiment are configured by the respective symbols SH1 to SH6 and the like.

(Description of Interface Module U2 of Example 1)
In FIG. 3, the operation unit UI of the interface module U2 includes a display unit UI1 for displaying information and an input button UI2 for performing various settings of the printer U. Further, the interface module U2 includes a main control unit C2 that receives image information transmitted from the external information transmission device COM and performs various processes and controls the printer U.
Inside the interface module U2, a curl removal path SH21 is provided as an example of a conveyance path of the bend removal device. The recording sheet S is conveyed to the curl removal path SH21 from the main body discharge path SH3 of the image forming apparatus main body U1. The recording sheet S conveyed to the curl removal path SH21 is conveyed to a module decurling apparatus Md as an example of a curvature removing apparatus main body by a conveyance roll MRa. The recording sheet S is decurled by the module decurling device Md, and is discharged from the decurling path SH21 to the stacker device U3 by the discharge roll MRh. The module decal device Md is conventionally known, and, for example, a configuration similar to the configuration described in Japanese Patent Application Laid-Open No. 2006-520333 can be adopted, and thus detailed description thereof is omitted.

(Description of Stacker Device U3 of Example 1)
In FIG. 3, the stacker device U3 according to the first embodiment includes a stacker discharge path SH31 connected to the curl removal path SH21 of the interface module U2 as an example of a conveyance path of the medium discharge stacking apparatus. A stacker discharge roll SRh as an example of a medium discharge member of the medium discharge stacking device is disposed on the downstream side of the stacker discharge path SH31 in the medium conveyance direction. The recording sheets S are discharged and stacked by the stacker discharge roll SRh in a stacker container TRh, which is an example of a stack container disposed below. In the stacker container TRh, as an example of a stacking member, a bottom plate TRh1 on which the recording sheets S are stacked is disposed on the top surface. The bottom plate TRh1 automatically moves up and down according to the loading amount of the recording sheets S.

(Description of Medium Transport Unit Sk of First Embodiment)
FIG. 5 is an explanatory diagram of the medium transport unit according to the first embodiment, FIG. 5A is an enlarged perspective view of the medium transport unit, and FIG. 5B is an explanatory diagram of opening and closing of the medium transport unit as viewed from the right.
FIG. 6 is an explanatory diagram of a state in which the medium transport unit is looked up diagonally to the right from the position on the diagonally lower left side.
5 and 6, the medium transport unit Sk according to the first embodiment includes a lower fixing portion 1 fixed to the image forming apparatus main body U1, and an upper portion supported to be openable and closable with respect to the fixing portion 1. Open / close part 2.

(Description of the fixing part 1 of Example 1)
The fixing unit 1 includes a fixing frame 3 supported by the image forming apparatus body U1 as an example of a frame.
The fixed frame 3 according to the first embodiment includes a lower chute 4 as an example of a lower guide member, and a front support plate 6 and a rear side as an example of a front support part that supports both front and rear ends of the lower chute 4 with upper ends. It has the back side support plate 7 as an example of a support part. Roller through-holes 4a are formed at the center in the front-rear direction, which is the medium width direction as an example of the width direction of the lower chute 4, with a space in the left-right direction.
The support plates 6 and 7 support the drive shaft 8 of the transport roll Ra extending in the front-rear direction at a position corresponding to the roller through hole 4a. The drive shaft 8 supports a drive roller 9 corresponding to the roller through hole 4a. The drive roller 9 is supported in a state where a part of the drive roller 9 penetrates the roller through hole 4a upward. Has been.
Further, a right tie bar 11 as an example of a right connection part and a left tie bar 12 as an example of a left connection part, which are disposed on both left and right sides, are supported at the lower ends of the support plates 6 and 7 of the first embodiment. ing.

That is, the support plates 6 and 7 according to the first embodiment are connected by the lower chute 4, the drive shaft 8, and the tie bars 11 and 12.
Further, latch receiving portions 13 and 14 as an example of held portions protruding forward are formed at a central portion of the front end surface 6a of the front support plate 6 of the first embodiment with an interval in the left-right direction. . In addition, guide bar support portions 16 and 17 as an example of a guide shaft support portion protruding forward are supported at lower ends of the left and right ends of the front end face 6a. Further, guide bars 18 and 19 as an example of guide shafts are supported on the front end portions of the guide bar support portions 16 and 17 so as to be rotatable about the rotation shafts 16a and 17a at the lower ends extending in the left-right direction. Yes. Further, the guide bars 18 and 19 are mounted with pressing springs 21 and 22 as examples of pressing members being passed therethrough.

Further, a right screw through hole 23 and a right protrusion through hole 24 as an example of a right fixing part are formed at the lower right end of the front support plate 6. Further, a right screw through hole 26 and a right protrusion through hole 27 as an example of a right adjustment fixing portion are formed above the right screw through hole 23 and the right protrusion through hole 24.
Similarly to the holes 23 to 27, a left screw through hole 28 and a left protrusion through hole 29 as an example of the left fixing portion are provided on the left lower end portion of the front support plate 6, and the left adjustment is performed. A left screw through hole 31 and a left protrusion through hole 32 are formed as an example of the fixing portion.
Further, at the lower end of the center of the front support plate 6, as with the screw through holes 26, 31 and the protrusion through holes 27, 32, a central screw through hole 33 and a central protrusion as an example of an accommodation fixing portion are provided. A through hole 34 is formed.

In FIG. 5B, an open / close bearing portion 35 protruding forward is supported on the front end surface 7a of the rear support plate 7 of the first embodiment.
5 and 6, a drive motor 36 as an example of a drive source that rotationally drives the transport roll Ra is supported on the left upper end portion of the rear end surface 7 b of the rear support plate 7 of the first embodiment. ing.
Further, the drive shaft 8 penetrates and extends rearward in the central portion of the rear end surface 7b in the vertical direction, and a plurality of shaft portions 37 extending rearward are formed between the penetrated drive shafts 8. Has been. A pulley 38 as an example of a drive transmission member is supported on the drive shaft 8 and the shaft portion 37, and the pulley 38 rotates endlessly by rotation of a rotation shaft (not shown) of the drive motor 36. A belt 39 as an example of a belt-like member is stretched.

Therefore, in the first embodiment, the driving force of the driving motor 36 is transmitted to the driving shaft 8 via the belt 39 and the pulley 38, so that the driving shaft 8 and the driving roller 9 are rotationally driven.
Also, rear brackets 41 and 42 as an example of rear supported parts extending rearward from the drive shaft 8 and the shaft portion 37 are spaced apart in the left-right direction at the central portion in the vertical direction of the rear end surface 7b. It is supported. Boss 41a, 42a as an example of the rear positioning part which protrudes back is formed in the rear end surface of the rear brackets 41, 42.
In Embodiment 1, when the medium transport unit Sk is attached to the image forming apparatus main body U1, the bosses 41a and 42a are fitted into holes (not shown) on the image forming apparatus main body U1 side. The transport unit Sk is positioned with respect to the image forming apparatus main body U1.

(Description of Opening / Closing Unit 2 of Example 1)
Further, the opening / closing part 2 is arranged as an example of a lower end wall so as to face the lower chute 4, and an upper chute 51 as an example of an upper guide member that forms the medium circulation path SH <b> 5 with the lower chute 4. Have Both front and rear ends of the upper chute 51 are supported by lower ends of a front support plate 52 as an example of a front support part and a rear support plate 53 as an example of a rear support part. The support plates 52 and 53 are connected by a right tie bar 54 as an example of a right connection part and a left tie bar 56 as an example of a left connection part.
In FIG. 5B, an opening / closing shaft 57 extending in the left-right direction is supported on the rear end surface 53 a of the rear support plate 53, and the opening / closing shaft 57 is rotatable on the opening / closing bearing portion 35 of the rear support plate 7. It is supported by. For this reason, the opening / closing part 2 according to the first embodiment is supported so as to be rotatable with respect to the fixed frame 3 with the opening / closing shaft 57 as a rotation center.

A roller through hole 51 a similar to the roller through hole 4 a of the lower chute 4 is formed at the center in the front-rear direction of the upper chute 51. The upper chute 51 has an upper end surface 51b formed with a driven bearing portion 51c protruding upward at a position corresponding to the roller through-hole 51a. The driven bearing portion 51c is connected to the drive shaft 8. A corresponding driven shaft 58 of the transport roll Ra is rotatably supported. The driven shaft 58 supports a driven roller 59 facing the drive roller 9 corresponding to the roller through-hole 52a, and the driven roller 59 partially includes the roller through-hole 52a. The lower end is supported so as to be able to contact the upper end of the drive roller 9 while penetrating downward.
Further, a sheet sensor SN1 as an example of a medium detecting member that detects the recording sheet S conveyed by the conveying roll Ra is disposed between the driven shafts 58.
Therefore, in the first embodiment, when the sheet sensor SN1 detects that the recording sheet S is carried into the medium transport unit Sk, the driving roller 36 is rotated between the driving roller 9 and the driven roller 59 by the driving motor 36. The sheet S is conveyed to the left on the downstream side in the medium conveyance direction while being sandwiched.

FIG. 7 is a perspective enlarged explanatory view of the handle and the latch according to the first embodiment.
5 and 7, a plate-like handle support portion 61 protruding forward is formed as an example of the operation support portion at the center of the front end surface 53a of the front support plate 53 of the first embodiment. Yes. An opening 61 a penetrating in the vertical direction is formed at the center in the left-right direction of the handle support portion 61. A handle 62 as an example of an operation unit is supported at the front end of the handle support unit 61. Further, bearing portions 63 and 63 that extend upward are supported at both ends in the left-right direction of the handle support portion 61. On the left and right outer sides of the bearing portions 63, 63, shaft support brackets 64, 64 as an example of bearing members extending forward from the front end surface 53a are supported.

  A lock shaft 66 extending in the left-right direction is rotatably supported by the bearing portions 63 and 63 and the shaft support brackets 64 and 64 as an example of a closing holding shaft. Base end portions 67 a and 67 a of latches 67 and 67 as an example of a closing and holding member are supported at both left and right end portions of the lock shaft 66. In FIG. 6, latches 67 and 67 are supported so as to be rotatable integrally with the lock shaft 66 around the base end portions 67 a and 67 a as rotation centers, and from the base end portions 67 a and 67 a to the latch receiving portions 13 and 14. Claw-like hook portions 67c and 67c that protrude rearward and can be hooked on the lower surfaces of the latch receiving portions 13 and 14 are formed at the leading end portions 67b and 67b that extend toward the rear.

A latch release lever 68 as an example of a closure release member is supported at the center in the left-right direction of the lock shaft 66. The latch release lever 68 includes a lever grip 69 that extends downward through the opening 61a as an example of a release operation portion.
In addition, a torsion spring 71 formed by winding a wire rod in a string form is attached to the central portion of the lock shaft 66 in the left-right direction as an example of an urging member. One end of the torsion spring 71 is supported by the handle support portion 61, and the other end is supported by a latch release lever 68.
The torsion spring 71 of the first embodiment is a so-called torsion spring, and always biases the lever grip 69 of the latch release lever 68 downward.
Further, guided portions 72 and 73 projecting forward are supported on the left and right ends of the front end surface 53a of the front support plate 53, and the guide bar 72 and 73 are supported on the front end portions thereof by the guide bar. Guide bar through-holes 72a and 73a through which 18 and 19 pass are formed.

(Description of movement between the closed position and the opened position of the opening / closing part 2 of the first embodiment)
Here, in the first embodiment, as shown by the solid lines in FIGS. 5A and 5B, the upper chute 51 of the opening / closing portion 2 faces the lower chute 4 of the fixing portion 1 during image forming operation, that is, so-called job execution. Thus, the medium circulation path SH5 is configured. That is, the opening / closing part 2 is in a state of moving to the closing position where the opening / closing part 2 is closed with respect to the fixing part 1.
At this time, on the front end faces 53a and 6a of the opening / closing part 2 and the fixing part 1, the latches 67 and 67 are urged downward by the biasing force of the torsion spring 71, and FIG. As shown in FIG. 2, the hooks 67c and 67c are held at the hooking positions where the hooks 67c and 67c are hooked. Therefore, the opening / closing part 2 is held at the closed position by the latching between the latches 67 and 67 and the latch receiving parts 13 and 14. The pressure springs 21 and 22 are pressed downward by the guided portions 72 and 73 and are held in a state of being contracted from the natural length.

  From this state, when a paper jam or the like occurs in the medium transport unit Sk and the medium circulation path SH5 is opened, when the lever grip 69 and the handle 62 are gripped by the operator, the lever grip 69 is moved upward. The latches 67 and 67 are rotated upward via the lock shaft 66 against the biasing force of the torsion spring 71, and the hook portions 67c and 67c are released from the latch receiving portions 13 and 14. Moves to, and the lock is released. Therefore, when the opening / closing part 2 is rotatable with respect to the fixed part 1 and an operator rotates the opening / closing part 2 upward, the opening / closing part 2 moves to an open position indicated by a broken line in FIG. The medium circulation path SH5 is opened.

As a result, in Example 1, the opening / closing part 2 can be moved between the closed position shown by the solid line in FIG. 5A and the open position shown by the broken line in FIG. 5B.
When the latches 67 and 67 are released, the pressing springs 21 and 22 press the guided portions 71 and 72 upward, thereby assisting the operator in lifting the opening / closing portion 2. Further, the pressing springs 21 and 22 exert a force in a braking direction when the opening / closing portion 2 is about to move from the open position to the closing position, so that the opening / closing portion 2 is contrary to the operator's intention due to its own weight or the like. Thus, the movement to the closed position can be suppressed, and the operability for the operator is improved.

(Description of Main Body Fixing Bracket 81 and Spacer 91 of Example 1)
FIG. 8 is an enlarged explanatory view of the main body fixing bracket of the first embodiment.
6 and 8, a pair of left and right main body fixing brackets 81, 81 are supported on the rear end surface 6b of the front support plate 6 of the first embodiment as an example of a main body fixing member. The medium transport unit Sk is fixed to the image forming apparatus main body U1 via brackets 81 and 81.
The main body fixing bracket 81 according to the first exemplary embodiment is an example of a support portion of the medium transport unit Sk that is disposed to face the rear end surface 6b and supports the rear end surface 6b, and has a flat plate shape as an example of a unit support portion. A frame body support portion 82; and a plate-like body supported portion 83 that extends rearward from the lower end of the frame body support portion 82 and is supported by the image forming apparatus body U1 below.
On the left side of the frame body support portion 82, a projection portion 84 is formed that projects forward and passes through each of the projection through holes 24 and 29 to position the frame body support portion 82. A screw hole 85 is formed on the right side of the frame body support portion 82, and screws 86, 86 passing through the screw through holes 23, 28 are screwed into the screw hole 85.

Accordingly, the right supported portion 6c is formed at the right end portion of the rear end face 6b formed with the holes 23 to 27 and supported by the right frame support portion 82, and the holes 28 to 32 are formed. A left supported portion 6d is formed at the left end portion of the rear end surface 6b that is formed and supported by the left frame support portion 82. That is, in the first embodiment, the right supported portion 6c and the left supported portion 6d are integrally disposed on the front support plate 6.
Further, a round hole-shaped main screw through hole 87 is formed on the left side of the main body supported portion 83, and a long main body screw through long hole extending in the left-right direction is formed on the right side of the main body supported portion 83. 88 is formed. The main body supported portion 83 is supported by the image forming apparatus main body U1 by screwing screws (not shown) penetrating the holes 87 and 88 into main screw holes (not shown) on the image forming apparatus main body U1 side. The

FIG. 9 is an enlarged explanatory view of the spacer of the first embodiment.
In FIG. 6, a spacer 91 as an example of an adjustment member is supported on the rear end surface 6 b of the front support plate 6 of the first embodiment.
6 and 9, the spacer 91 according to the first embodiment includes a flat spacer body 91a that is disposed to face the rear end face 6b as an example of an adjustment member body. An extension 91b extending leftward is formed at the upper left end of the spacer body 91a. The left end of the extension 91b protrudes forward and passes through the protrusion through holes 27, 32, and 34. Thus, a protrusion 92 that can position the spacer 91 is formed. A screw hole 93 is formed at the upper right end of the spacer body 91a. The screw hole 93 can be screwed by a screw 94 that passes through the screw through holes 26, 31, and 33. Further, a conical wall-shaped conical wall projecting portion 96 projecting rearward is formed in the central portion of the spacer body 91a, and the conical wall projecting portion 96 has a screw through hole 96a penetrating in the front-rear direction. Is formed. The screw through hole 96a of the first embodiment is formed to have a larger diameter than the screw hole 86 of the main body fixing bracket 81.

(Explanation of attachment / detachment of the spacer 91 of the first embodiment)
In FIG. 6, in Example 1, the protrusion 91 is positioned through the central protrusion through hole 34, and the screw hole 93 is screwed to the screw 94 that passes through the central screw through hole 33, so that the spacer 91 is fixed. The spacer 91 is accommodated in the medium transport unit Sk by being supported by the central portion of the rear end face 6b.
Therefore, the accommodating portion 6e of the spacer 91 is formed in the central portion of the rear end face 6b in which the holes 33 and 34 are formed and the spacer 91 is accommodated. In other words, in the first embodiment, the housing portion 6 e is integrally disposed on the front support plate 6.

FIG. 10 is an explanatory diagram of a state in which a spacer is mounted between the right supported portion and the right frame support portion from the state of FIG.
FIG. 11 is an enlarged explanatory view of a main part in a state in which the medium transport unit in which the spacer is mounted between the right supported part and the right frame support part is viewed from below the lower chute.
FIG. 12 is an explanatory view of the inclination of the medium transport unit, and FIG. 12A is an illustration of a state in which the medium transport unit in which a spacer is mounted between the right supported part and the right frame support part is looked down from above. FIG. 12B is an explanatory diagram of a state in which the medium transport unit in which a spacer is mounted between the left supported portion and the left frame supporting portion is viewed from above.
In the first embodiment, as shown in FIGS. 10 to 12, the spacer 91 is interposed between the supported portions 6 c and 6 d of the rear end wall 6 b and the frame support portion 82 of the main body fixing bracket 81. It can also be installed.

  Specifically, when the spacer 91 is mounted between the right supported portion 6c and the right frame support portion 82, first, the right supported portion 6c and the right frame support portion 82 are connected to each other. The medium transport unit Sk is detached from the image forming apparatus main body U1 at a distance. Next, the protrusion 92 is passed through the right protrusion through hole 27 and the screw hole 93 is screwed with a screw 94 passing through the right screw through hole 26 to support the spacer 91 on the right supported part 6c. . Then, the protrusion 84 is passed through the right protrusion through hole 24 and the screw hole 85 is screwed with a screw 86 passing through the screw through holes 23 and 96a, and the right supported portion 6c is fixed to the right body fixing bracket. By supporting 81, the spacer 91 is mounted between the right supported portion 6c and the right frame supporting portion 82.

  As a result, as shown in FIGS. 10 and 11, when the spacer 91 is mounted between the right supported portion 6 c and the right frame support portion 82, as indicated by the one-dot chain line in FIG. 12A. Further, the right end portion of the medium transport unit Sk is disposed in front of the left end portion, and the medium transport unit Sk is fixed to the image forming apparatus body U1 in a state inclined with respect to the left-right direction. Therefore, when the recording sheet S is carried into the inclined medium conveying unit Sk, the recording sheet S is conveyed in a direction inclined backward from the left-right direction which is the medium conveying direction by the conveying roll Ra. That is, when the spacer 91 is mounted, the recording sheet S is transported in a direction that intersects the medium transport direction of the recording sheet S when the spacer 91 is not mounted.

Further, when the spacer 91 is mounted between the left supported portion 6d and the left frame support portion 82, the medium transport unit Sk is removed from the image forming apparatus main body U1, and the spacer 91 is removed from the left supported portion. 6d, the spacer 91 is mounted between the left supported part 6d and the left frame support part 82 by supporting the left supported part 6d by the left body fixing bracket 81. It becomes a state.
As a result, when the spacer 91 is mounted between the left supported portion 6d and the left frame support portion 82, as shown by the two-dot chain line in FIG. 12B, the left end portion of the medium transport unit Sk. Is disposed in front of the right end, and is fixed to the image forming apparatus body U1 in a state where the medium transport unit Sk is inclined with respect to the left-right direction. Therefore, when the recording sheet S is carried into the inclined medium conveying unit Sk, the recording sheet S is conveyed in a direction inclined forward from the left-right direction which is the medium conveying direction by the conveying roll Ra.

Here, in the first embodiment, even when the spacer 91 is mounted between the supported parts 6c and 6d and the frame support part 82, the main body screw of the image forming apparatus main body U1 is formed by the main body screw through long hole 88. The upper part of the hole is opened. For this reason, the screw which penetrated the main body screw penetration long hole 88 can be screwed to the main body screw hole. That is, the main body supported portion 83 can be fixedly supported on the image forming apparatus main body U1 by two screws passing through the holes 87 and 88.
Further, as shown in FIG. 11, with respect to the spacer 91 and the frame body support portion 82, only the rear end portion of the conical wall projecting portion 96 is in contact with the frame body support portion 82. The contact area with 82 is small.
Here, if the conical wall protrusion 96 is not formed and the spacer 91 and the frame support 82 are screwed in a state of facing each other, the medium transport unit Sk and the image forming apparatus main body U1 are used. Are inclined, and the plate-like spacer main body 91a and the frame support portion 82 which are inclined to each other are screwed together.

In this case, if the screw 86 is tightened too much, the inclined spacer body 91a and the frame body support portion 82 are distorted until they come into surface contact, and the medium transport unit Sk to which the spacer 91 is fixed is twisted or distorted as a whole. There is a risk of deformation. Then, when the medium transport unit Sk is twisted, there is a risk that a transport failure such as a change in the transport direction of the recording sheet S may occur.
On the other hand, in the first embodiment, since the contact is made by the cone wall projection 96, when the screw is fastened, the contact surface is small and distortion is small. Even if the screw 86 is tightened too much, the cone is mainly used. By only distorting the wall protrusion 96, the influence on the distortion and the like of the entire medium transport unit Sk can be reduced. For this reason, a conveyance failure such as a change in the conveyance direction of the recording sheet S conveyed by the medium conveyance unit Sk due to the deformation of the medium conveyance unit Sk is reduced.

In FIG. 12, in the first embodiment, an upstream gap SP1 is formed on the right side of the right end of the medium transport unit Sk, and on the downstream side of the left end of the medium transport unit Sk. The gap SP2 is formed. The gaps SP1 and SP2 of the first embodiment are sufficient to allow the medium transport unit Sk to tilt, and can be set to 3 [mm], for example.
In addition, the frame length L1 that is the length in the left-right direction of the fixed frame 3 of the first embodiment is set to be equal to or greater than the maximum medium length that is the length in the left-right direction of the maximum size of the recording sheet S. Specifically, it is set to 488 [mm] which is 420 [mm] or more which is the length in the left-right direction of “A3SEF (Short Edge Feed)” which is a preset maximum size.

Further, the frame width L2 that is the length in the front-rear direction of the fixed frame 3 of the first embodiment is set to be larger than the medium maximum width that is the length in the front-rear direction of the maximum size of the recording sheet S. . Specifically, it is set to 345 [mm] which is larger than 297 [mm] which is the length in the front-rear direction of “A3SEF”.
The medium transport unit Sk, the main body fixing bracket 81, the spacer 91, and the like constitute the adjustment unit (Sk + 81 + 91) of the first embodiment.

(Description of loading position of skew correction unit Sh of Embodiment 1)
FIG. 13 is an explanatory diagram of the carry-in position of the skew correction unit according to the first embodiment.
In FIG. 13, a recording sheet S carry-in portion Sha is formed at the left end of the skew correction unit Sh according to the first embodiment. In Embodiment 1, the recording sheet S loading position in the loading section Sha is set in advance so that the front end of the recording sheet S is located behind the side guide SGa and behind the preset abutting interval L3. ing.
The carry-in portion Sha of the skew correction unit Sh, the cross and roll Rc, the side guide SGa, and the like constitute the alignment portion (Sha + Rc + SGa) of the first embodiment.

(Operation of Example 1)
In the printer U according to the first embodiment having the above-described configuration, when a job is executed, the recording sheet S supplied from the manual feed medium supply unit (not shown) and the paper feed trays TR1 and TR2 is conveyed through the medium supply path SH1, After the skew correction is performed by the skew correction unit Sh, the toner image is transported by the registration roll Rr in accordance with the transport timing to the secondary transfer area Q4, and an image is recorded on the first surface. When images are recorded on both sides of the recording sheet S, the recording sheet S on which the image is recorded in the secondary transfer area Q4 has the fixing area Q5, the main body processing path SH2, the reversing path (SH4 to SH6), and After passing through the medium supply path SH1, the recording sheet S that has been recorded on one side is turned upside down and is carried back into the carry-in portion Sha of the skew correction unit Sh.

Here, in the printer U according to the first embodiment, as shown in FIGS. 1 and 2, the conveyance path (Q4, 4) until the reversal sheet S that has passed through the reversal path (SH4 to SH6) is carried into the carry-in portion Sha. The length of Q5, SH2, SH4 to SH6, SH1) is set to be longer than the length of the conveyance path (SH1) until the first recording sheet S is carried into the carry-in portion Sha. Therefore, the number of transport rolls Ra arranged on the transport path (SH1) increases, and the medium transport directions of all the transport rolls Ra are not accurately aligned due to an installation error during manufacture of the printer U, and the medium transport direction is wide. There is a possibility of tilting in the direction.
In the printer U according to the first exemplary embodiment, the conveyance path between the secondary transfer area Q4 and the fixing area Q5 and the conveyance path between the reversing path (SH4 to SH6) and the medium supply path SH1 are as follows. The image recording unit U1a and the fixing reversing unit U1b are connected by different housings. Therefore, there is a possibility that the connecting portion is displaced in the front-rear direction, which is the width direction, due to an assembly error when the printer U is installed.

Further, in the printer U according to the first exemplary embodiment, the first recording sheet S is accurately positioned in the width direction by the side edge aligning members (not shown) of the manual feeding medium supply unit and the paper feed trays TR1 and TR2. On the other hand, the reversing sheet S is not positioned in the width direction after the image is recorded on the first surface until the reversing sheet S is loaded again into the loading portion Sha.
Therefore, the reversal sheet S is compared with the recording sheet S on the first surface from the loading position shown in FIG. In the width direction), and the skew correction unit Sh may not be able to correct the skew. If the loading position of the recording sheet S greatly deviates forward, in the worst case, it exceeds the loading range of the loading portion Sha, and the front end of the recording sheet S in the medium conveyance direction is the upstream end of the side guide SGa in the medium conveyance direction. There is also a possibility that a paper jam or the like occurs due to the bump.

In contrast, in the first embodiment, when the printer U is installed, the spacer 91 is first accommodated in the accommodating portion 6e inside the medium conveying unit Sk so that the medium conveying unit Sk is not inclined with respect to the image forming apparatus main body U1. In the state, as an adjustment operation, the reversal sheet S that has passed through the reversal path (SH4 to SH6) is carried into the carry-in portion Sha of the skew correction unit Sh. When the conveyed recording sheet S is displaced or tilted in the front-rear direction from the carry-in position, as shown in FIG. 12, a spacer 91 is attached on the side that cancels the deviation or tilt of the reversed sheet S and is carried in. Position adjustment is complete.
For example, when the reversal sheet S is displaced forward from the carry-in position, the spacer 91 is mounted between the right supported portion 6c and the frame support portion 82, and the medium transport unit Sk is shown in FIG. 12A. In this state, the image forming apparatus body U1 is tilted and fixed. For this reason, the reversal sheet S carried into the medium carrying unit Sk is carried in a direction inclined rearward from the left-right direction, and the front shift in the carry-in portion Sha is canceled.

As a result, the printer U according to the first embodiment has a spacer 91 between the supported portions 6c and 6d and the frame support portion 82, as compared with the conventional configuration in which the spacer 91 is attached and the medium transport unit Sk is not inclined. The shift in the width direction of the recording sheet S is reduced with a simple configuration of mounting the. Therefore, the printer U according to the first exemplary embodiment aligns the reversal sheet S that has passed through the second conveyance path (SH4 to SH6, SH1), that is, the position and orientation of the sheet such as side registration correction, lead registration correction, and skew correction. A misalignment that is a misalignment of correction is suppressed.
Further, in the printer U according to the first embodiment, the carry-in position of the carry-in portion SHa is set to a position that is separated from the side guide SGa and rearward from the abutting interval L3, and compared to the case where the carry-in portion SHa is not separated from the side guide SGa. The clogging of the recording sheet S is reduced, and the inclination of the recording sheet S is corrected with high accuracy.

In the printer U of the first embodiment, the frame length L1 and the frame width L2 of the fixed frame 3 are set to be larger than the maximum size of the recording sheet S.
Here, if the frame length L1 is shorter than the maximum size of the reversal sheet S, the reversal sheet S is in a state of straddling the transport roll Ra inside the medium transport unit Sk and the transport roll Ra outside the medium transport unit Sk. The reversing sheet S is twisted between the transport roll Ra inside the medium transport unit Sk that is easy to be transported and the medium transport unit Sk that is about to tilt, and the transport roll Ra outside the medium transport unit Sk that is not tilted. Wrinkles may occur. In addition, in the state straddling between the transport roll Ra inside the medium transport unit Sk that intends to tilt the medium transport direction and the transport roll Ra outside the medium transport unit Sk that does not try to tilt, the inside of the medium transport unit Sk Compared to the case where the transport roll Ra is transported only by the transport roll Ra, the transport roll Ra outside the medium transport unit Sk may interfere with the inclination of the medium transport direction in the transport roll Ra inside the medium transport unit Sk.

  In contrast, in the printer U according to the first embodiment, the frame length L1 is set to be longer than the maximum size of the reversal sheet S, and a period during which the entire reversal sheet S is accommodated in the medium transport unit Sk is secured. Further, it is possible to transport the medium in the direction to cancel the deviation only by the transport roll Ra inside the medium transport unit Sk. As a result, compared to the case where the reverse sheet S is transported across the transport rollers inside and outside the medium transport unit Sk, the transport in the direction to cancel the deviation of the reverse sheet S is not hindered, and the twist and wrinkles of the reverse sheet S are generated. Is reduced.

(Example of change)
As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example, A various change is performed within the range of the summary of this invention described in the claim. It is possible. Modification examples (H01) to (H07) of the present invention are exemplified below.
(H01) In the above embodiment, the printer U as the image forming apparatus has been exemplified. However, the present invention is not limited to this, and a FAX, a copying machine, or a multifunction machine having all or a plurality of functions may be used. Further, the present invention is not limited to a monochrome image forming apparatus, and can be applied to a color image forming apparatus. Furthermore, the present invention can also be applied to an ink jet recording type image forming apparatus other than an electrophotographic image forming apparatus, a thermal transfer type image forming apparatus, and the like.

(H02) In the above-described embodiment, the skew correction unit Sh is disposed in the image recording unit U1a, and the medium transport unit Sk is disposed in the fixing reversing unit U1b so that the units Sh and Sk are held in different housings. However, the present invention is not limited to this, and when the medium transport unit Sk is disposed upstream of the skew correction unit Sh in the medium transport direction, the units Sh and Sk are both disposed in the image recording unit U1a. Even when it is arranged in the fixing reversal portion U1b, the effects of the present invention can be obtained. For this reason, the medium transport unit Sk is not limited to being disposed in the medium circulation path SH5, and may be disposed in other transport paths SH2, SH4, SH6, and SH1 upstream of the skew correction unit Sh in the medium transport direction. Is possible.

(H03) In the above embodiment, the lower end of the medium transport unit Sk is supported by the image forming apparatus main body U1 via the main body fixing bracket 81. However, the medium transport unit Sk is supported by the image forming apparatus main body U1. The position is not limited to the lower end, and if the spacer 91 is attached and the medium transport unit Sk can be tilted in the front-rear direction, for example, the upper end and both front and rear ends of the medium transport unit Sk are supported by the image forming apparatus body U1. It is also possible to adopt a configuration that is suspended in the air.
(H04) In the above-described embodiment, one type of spacer 91 is mounted and the medium transport unit Sk is tilted by a preset tilt angle with respect to the image forming apparatus body U1, but this is not limitative. For example, several types of spacers 91 having different lengths in the front-rear direction of the conical wall projecting portion 96 are prepared, and either one is selectively mounted according to the degree of inclination, and the inclination angle is adjusted. It is also possible.

(H05) As in the above embodiment, it is preferable to form the conical wall protrusion 96 on the spacer 91 to reduce deformation such as torsion and distortion of the entire medium transport unit Sk. As long as it can be mounted between each supported portion 6c, 6d and the right frame support portion 82, it can be arbitrarily changed, and the conical wall protruding portion 96 can be omitted.
(H06) As in the above-described embodiment, it is preferable that the spacer 91 can be accommodated in the accommodating portion 6e inside the medium conveying unit Sk. However, the present invention is not limited to this, and the accommodating portion 6 is omitted and the medium conveying unit Sk is omitted. It is also possible to store the information outside the storage.
(H07) Although it is preferable that the frame length L1 of the fixed frame 3 is set to be equal to or larger than the maximum medium length of the recording sheet S as in the above embodiment, the shift of the reverse sheet S is sufficiently canceled. It is also possible to set the frame body length L1 of 3 shorter than the maximum medium length.

DESCRIPTION OF SYMBOLS 3 ... Frame, 6c, 6d ... Supported part, 6e ... Accommodating part, 82 ... Supporting part, 91 ... Adjustment member, L1 ... Frame body length, Ra ... Medium conveying member, S ... Medium, SGa ... Side edge alignment member, (Sha + Rc + SGa) ... Alignment section, Sh ... First unit, Sha ... Load-in section, SH1 ... First transport path, (SH4-SH6) ... Reverse path, (SH4-SH6, SH1) ... Second transport path, (Sk + 81 + 91) ... Adjusting unit, Sk ... Second unit, SP1 ... Upstream gap, SP2 ... Downstream gap, Q4 ... Image recording area, U ... Image forming apparatus, U1 ... Image forming apparatus body, (UG + GG) to (UK + GK) , T1g to T1k + T2 + B... Image forming unit.

Claims (7)

An image forming unit for forming an image on a medium;
A first conveyance path through which the medium conveyed to the image forming unit passes;
A second transport path that is coupled to the first transport path and through which the medium passes when the medium on which an image is formed on one side by the image forming section is transported to the image forming section again.
An alignment unit provided on the first conveyance path for aligning the medium conveyed to the image forming unit;
An adjustment unit that is provided on the second conveyance path and adjusts the position in the width direction perpendicular to the conveyance direction of the medium conveyed to the alignment unit;
An image forming apparatus comprising: An image forming apparatus main body having the respective transport paths;
The alignment unit having the first unit for conveying the medium carried in from the carry-in unit to the downstream side in the conveyance direction;
The adjusting unit having a second unit for conveying the medium to the first unit;
A frame of the second unit that rotatably supports a medium conveying member that conveys the medium;
A supported portion provided in the frame;
A support portion provided in the image forming apparatus main body and supporting the supported portion from the width direction;
When the second unit is configured to be detachable between the supported part and the support part and is mounted between the supported part and the support part, the second unit is moved in the width direction with respect to the transport direction. And an adjustment member that adjusts the position in the width direction of the medium conveyed by the medium conveyance member, and a carry-in range in which a carry-in position at which the medium is carried into the carry-in unit is set in advance The adjustment member for inclining the second unit so as to be inside the carry-in range when the outer side is outside,
The image forming apparatus according to claim 1, further comprising: The first unit having a side edge aligning member that aligns the widthwise side edges of the medium;
The second transport path having a reversing path for reversing the front and back of the medium on which the image is recorded on one side through an image recording area in which an image is recorded on the medium and bringing the medium into the loading section;
The carry-in position in which the width direction side end of the medium on the side end alignment member side is set at a position away from the side end alignment member in the width direction;
The image forming apparatus according to claim 1, further comprising: The frame length, which is the length of the frame in the transport direction, is set to be equal to or greater than a maximum medium length, which is a maximum value of the length of the medium in the transport direction. 4. The image forming apparatus according to any one of items 3 to 3. A drive source provided on the frame for rotating the medium conveying member;
The image forming apparatus according to claim 1, further comprising: A housing part that is provided in the frame body and that accommodates the adjustment member removed from between the supported part and the support part when the second unit is not inclined;
The image forming apparatus according to claim 1, further comprising: An upstream gap formed between the upstream end of the second unit in the transport direction and the second transport path upstream of the second unit in the transport direction;
A downstream gap formed between the downstream end of the second unit in the transport direction and the second transport path on the downstream side of the second unit in the transport direction;
The image forming apparatus according to claim 1, further comprising:

Images