JP5293518B2 - Image forming apparatus and assembly method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately match a feed paper conveying unit and a delivery paper conveying unit with position of the guide roller of each image forming unit without depending on connection accuracy of a housing. <P>SOLUTION: In an image forming apparatus, from the upstream side to the downstream side in the conveying direction of a medium 1 to be recorded, there are connected to each other a feed paper conveying unit 2 having a conveying guide roller 7, one or more image forming units 3a-3d having a conveying guide roller 13, and a delivery paper conveying unit 4 having a conveying guide roller 20. The apparatus includes a positioning member 22 which extends from the feed paper conveying unit 2 to the delivery paper conveying unit 4 and which has a positioning part 28 formed each engaging with the respective guide rollers 7, 13, 20, With end parts of the respective guide rollers 7, 13, 20 engaged with each positioning part 28, using as a reference a position of the guide roller 7 of the feed paper conveying unit 2 and the guide roller 20 of the delivery paper conveying unit 4, the positioning of the guide roller 13 of the image forming unit is performed for the guide rollers 7, 20 by means of the positioning member 22. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

The present invention relates to an inkjet system that forms an image by ejecting droplets onto a sheet, an electrophotographic system that forms an image by transferring a toner image on a photosensitive drum onto a sheet, and a printing machine that uses an uneven plate or a stencil In particular, an image in which a paper feed conveyance unit, one or a plurality of image forming units, and a paper discharge conveyance unit are detachably connected from the upstream side to the downstream side in the conveyance direction of a recording medium. The present invention relates to a forming apparatus and an assembling method thereof.

 In recent years, in the field of image forming apparatuses, there has been a demand for an image forming apparatus that has a high degree of freedom in function expansion and change in accordance with specifications, and that can reduce development and manufacturing costs. There is a proposal like that.

 Patent Document 1 describes an image forming apparatus in which a plurality of image forming units each provided with an ink jet engine that ejects ink droplets are detachably connected.

 Further, in Patent Document 2, a plurality of inkjet print units are arranged at predetermined intervals along the conveyance direction of the continuous paper so that multiple colors can be printed on the front and back of the continuous paper, and marks formed on the continuous paper An ink jet printing system is described in which the printing start of the ink jet printing unit is controlled based on the detection signal.

 7 and 8 are a schematic configuration diagram and a top view of an image forming apparatus in which a conventional paper feed conveyance unit, a plurality of image forming units, and a paper discharge conveyance unit are connected in a separable manner. Here, an example of an ink jet system in which an ink head is mounted as an image forming unit is shown.

 As shown in FIG. 7, in the image forming apparatus 201, four image forming units 3 a to 3 d are interposed between the paper feed transport unit 2 and the paper discharge transport unit 4. The ink color array of the ink head 12 in the image forming unit 3a is YYYY, the ink color array of the image forming unit 3b is MMMM, and the ink color array of the image forming unit 3c is CC. The ink color arrangement of -C-C and the image forming unit 3d is KK-KK, and four ink heads 12 for each color are mounted.

 An ink cassette 10 corresponding to each color is mounted on the top of the ink head 12, and an ink supply path (not shown) for supplying ink in the ink cassette 10 to the ink head 12 is provided inside.

 The sheet feeding / conveying unit 2 includes an infeed roller 5, a nip roller 6, a plurality of guide rollers 7, a motor (not shown) for driving the infeed roller 5, and the like. Further, the paper discharge transport unit 4 includes an outfeed roller 18, a nip roller 19, a plurality of guide rollers 20, a motor (not shown) for driving the outfeed roller 18, and the like. A caster 9 with a stopper is provided in the lower part of each of the paper feed transport unit 2, the paper discharge transport unit 4, and the image forming units 3a to 3d.

 FIG. 9 is a perspective view of the image forming unit 3 in the conventional image forming apparatus. The head base 27 on which the ink head 12 is mounted is fixed on a rail 17 installed between the front frame 24 and the rear frame 25, and the ink head 12 is used for maintenance operations (wiping, ink discharge detection, etc.). The rail 17 is movable to the maintenance mechanism 8 (see FIG. 8).

 In the case of an ink jet printer, the gap G (see FIG. 9) between the ink head 12 and the platen roller 13 is important because the influence of ink droplet merging and the airflow of the recording paper (web) 1 has a great influence on the print quality. Become.

 Therefore, as shown in FIG. 9, in the assembly stage, the height adjustment unit 21 that adjusts the height of the rail 17 on which the head base 27 of the ink head 12 is mounted and the position adjustment of the platen roller 13 are carefully performed. Reference numeral 23 in the figure denotes a power source, and 26 denotes a base frame.

 With the above configuration, the image forming apparatus 201 has a high degree of freedom in expansion and change of each function in response to demands for higher printing speed, higher printing quality, and higher image quality. It is possible to realize an image forming apparatus of a unit connection system that can reduce the cost.

  From the viewpoint of preventing color misregistration, there is a proposal as described in Patent Document 3 as a similar image forming unit positioning unit. The image forming apparatus described in Patent Document 3 positions the inclination and position of the rotation axis of each color image carrier using a single alignment member, and the alignment member is positioned and fixed with respect to the main body frame. It has a structured.

 In the conventional image forming apparatus, when a plurality of image forming units 3 are connected, the positional accuracy of the platen roller 13 of the adjacent image forming units 3 depends on the connection accuracy between the casings. For this reason, when the base frame 26 (see FIG. 9) of the image forming unit 3 is twisted or when the connecting position of the casing is insufficient, for example, as shown by the arrow in FIG. As indicated by the arrows, the discharge direction of 1 differs for each of the image forming units 3a, 3b, 3c, and 3d, and causes the meandering and wrinkling of the paper 1. As a result, not only the image quality is deteriorated, but also printing is stopped due to poor conveyance in some cases.

 In that case, it is necessary to readjust the position of the platen roller 13 in each of the image forming units 3a to 3d. At the same time, it is also necessary to readjust the gap G between the ink head 12 and the platen roller 13 adjusted at the time of assembly. There is a problem that enormous time is required in the connection work including adjustment.

 Further, in the content proposed in Patent Document 3, in the image forming apparatus in which a plurality of units as described above are connected, since the frame is divided, it is structurally impossible, and is assumed to be an integrated configuration. However, there is a problem that the image forming apparatus is increased in size. Further, unlike the case of the cut sheet, since the eccentricity and arrangement accuracy of the guide rollers 7 and 20 and the platen roller 13 (see FIG. 7) appear as color misalignment in the case of continuous paper, the alignment member is positioned on the frame. In this case, since the intersections are accumulated, it is considered preferable to provide and guide the guide rollers 7 and 20 as a reference.

SUMMARY OF THE INVENTION An object of the present invention is an image forming apparatus in which a paper feed transport unit, a plurality of image forming units, and a paper discharge transport unit are connected in a separable manner. It is an object of the present invention to provide an image forming apparatus capable of aligning the positions of the guide rollers and the guide rollers of each image forming unit with high accuracy and an assembling method thereof.

In order to achieve the above object, the first present invention provides:
From the upstream side to the downstream side in the recording medium conveyance direction, a sheet feeding conveyance unit having a recording medium conveyance guide roller and one or a plurality of recording medium conveyance guide rollers such as a platen roller described later In an image forming apparatus configured by connecting the image forming unit and a paper discharge transport unit having a recording medium transport guide roller,
An alignment member that extends from the paper feed conveyance unit to the paper discharge conveyance unit and that forms an alignment portion that engages with each guide roller;
Engage the end portions of the guide rollers with the alignment portions of the alignment members,
The position of the guide roller of the image forming unit with respect to the guide roller of the paper feed transport unit and the paper discharge transport unit by the alignment member based on the position of the guide roller of the paper feed transport unit and the guide roller of the paper discharge transport unit It is characterized by combining.

In order to achieve the above object, the second present invention provides:
From the upstream side to the downstream side in the recording medium conveyance direction, a paper feeding conveyance unit having a recording medium conveyance guide roller, and one or a plurality of image forming units having a recording medium conveyance guide roller, In an assembling method of an image forming apparatus configured by connecting a discharge conveyance unit having a recording medium conveyance guide roller,
A gap adjusting step in which a guide roller and an image forming unit constituting the image forming unit are installed on a unit frame, and a gap between the guide roller and the image forming unit is adjusted and held constant;
The unit frame is placed on the unit base, and an image is formed by penetrating the end portion of the guide roller through a vertically long guide portion formed at a position facing the guide roller on the front wall and the rear wall of the unit base. The process of assembling the unit;
Out of the alignment portions of the alignment members, each of which is formed with an alignment portion that engages with each of the guide rollers, an end portion of each guide roller of the image forming unit is aligned with the alignment portion corresponding to the guide roller of the image forming unit. And then engaging the end portions of the guide rollers of the paper feed / conveyance unit with the alignment portions corresponding to the guide rollers of the paper feed / conveyance unit respectively. The ends of the guide rollers of the paper discharge conveyance unit are engaged with the corresponding alignment portions, one end of the alignment member is attached to the paper feed conveyance unit, and the other end of the alignment member is connected to the paper discharge conveyance. It has the positioning member attachment process attached to a unit, It is characterized by the above-mentioned.

 According to the present invention, in the image forming apparatus in which the paper feed transport unit, the image forming unit, and the paper discharge transport unit are connected in a separable manner, the guide roller of the paper feed and paper discharge transport unit can The position of the guide roller (platen roller) of the image forming unit can be set with high accuracy. For this reason, problems such as a decrease in image quality and stoppage of printing due to poor running of the recording medium are solved.

Further, according to the embodiment of the present invention , the guide roller (platen roller) and the image forming means of each image forming unit are integrally formed on the unit frame, and the guide roller even when the connecting position of the casing is insufficient. The gap between the (platen roller) and the image forming unit can be kept constant.

Further, according to the embodiment of the present invention , the guide roller of the paper feeding / conveying unit, the guide roller (platen roller) of one or a plurality of image forming units, and the guide roller that runs on the guide roller of the paper discharging / conveying unit. Since the travel trajectory of the recording medium is set on the opposite side to the mounting direction of the image forming means, that is, in a curved state so that the central portion protrudes upward, each guide roller (platen roller) of the image forming unit The recording medium can be reliably brought into contact with the recording medium.

1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention. 2 is a partial perspective view of the image forming apparatus. FIG. It is a front view of the alignment member used for embodiment of this invention. It is a perspective view of a unit frame carrying an ink head and a platen roller according to an embodiment of the present invention. 1 is a perspective view of an image forming unit according to an embodiment of the present invention. 1 is a top view of an image forming apparatus according to an embodiment of the present invention. It is a schematic block diagram of the conventional image forming apparatus. It is a top view of the image forming apparatus. 2 is a perspective view of an image forming unit of the image forming apparatus. FIG. It is a top view for demonstrating the subject of the conventional image forming apparatus.

  Next, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention, FIG. 2 is a partial perspective view of the image forming apparatus, and FIG. 3 is a front view of an alignment member used in the image forming apparatus.

 As shown in FIG. 1A, the image forming apparatus 202 according to the first embodiment of the present invention includes four sheet feeding / conveying units 2 from the upstream side toward the downstream side in the conveying direction of the recording paper (web) 1. The image forming units 3a to 3d and the paper discharge transport unit 4 are arranged in this order, and the units are connected to each other so as to be separable.

 Although not shown, a paper transport outlet is formed on one side surface of the paper feed transport unit 2, a paper transport inlet is formed on one side surface of the image forming unit 3, and a paper sheet is formed on the other side surface on the opposite side. A conveyance outlet is formed, and a paper conveyance inlet is formed on one side surface of the paper discharge conveyance unit 4.

 Then, by arranging the sheet feeding / conveying unit 2, the plurality of image forming units 3a to 3d, and the sheet discharging / conveying unit 4 as described above, the sheet conveying outlet of the sheet feeding / conveying unit 2 and the most upstream image forming unit adjacent thereto. 3a, the paper conveyance inlet of the image forming unit 3 on the upstream side in the paper conveyance direction is matched with the paper conveyance inlet of the downstream image forming unit 3 adjacent thereto, and the most downstream image forming unit 3d One image forming apparatus is configured by matching the sheet conveyance outlet and the sheet conveyance inlet of the paper discharge conveyance unit 4 adjacent thereto.

 Each of the image forming units 3a to 3d has four ink cassettes 10 and ink heads 12 serving as image forming means. In this embodiment, one image forming unit 3 is, for example, YYYYY. It has a configuration that bears a single color. Here, an example of an ink jet type in which the ink head 12 is mounted on the image forming means is shown. However, as the image forming means, an electrophotographic method composed of a photosensitive drum and a developing unit, or a drum around which plate making is rotated is rotated. It is also possible to use a plate printing method for printing.

 The sheet feeding / conveying unit 2 has an infeed roller 5, a nip roller 6, a plurality of guide rollers 7, a motor (not shown) for driving the infeed roller 5, and the like at predetermined positions inside. Further, the paper discharge transport unit 4 has an outfeed roller 18, a nip roller 19, a plurality of guide rollers 20, a motor (not shown) for driving the outfeed roller 18, and the like at predetermined positions inside. A caster 9 with a stopper is provided in the lower part of each of the paper feed transport unit 2, the paper discharge transport unit 4, and the image forming units 3a to 3d.

 As shown in FIGS. 1 and 2, the alignment member 22 made of a plate material having rigidity such as metal or reinforced plastic is discharged from the sheet feeding / conveying unit 2 through a plurality of image forming units 3 a to 3 d. This alignment member 22 guides the guide roller 7 of the paper feeding / conveying unit 2, the platen rollers 13 of the plurality of image forming units 3a to 3d, and the guide roller 20 of the paper discharging / conveying unit 4. Are aligned. If the plate-like alignment member 22 is used in this way, the function of the alignment member 22 can be exhibited without substantially increasing the width of the image forming apparatus. Since the alignment member 22 is long, reinforcing ribs extending in the longitudinal direction of the alignment member 22 can be provided as necessary.

 As shown in FIG. 2 and FIG. 3A, an alignment engaging portion 28a into which the shaft of the guide roller 7 of the sheet feeding / conveying unit 2 is inserted is positioned near one end of the alignment member 22. Near the other end of the aligning member 22, an alignment engaging portion 28 b into which the shaft of the guide roller 20 of the paper discharge transport unit 4 is inserted is formed. Between the positioning engaging portions 28a and 28b, the positioning engaging portion 28c into which the shaft of the platen roller 13 of the first image forming unit 3a is inserted, and the second image forming unit 3b. The alignment engaging portion 28d into which the shaft of the platen roller 13 is inserted, the alignment engaging portion 28e into which the shaft of the platen roller 13 of the third image forming unit 3c is inserted, and the fourth image forming. Alignment engaging portions 28f into which the shafts of the platen roller 13 of the unit 3d are inserted are formed.

 As shown in FIG. 1, the conveyance path of the paper 1 drawn by the guide roller 7 of the paper feeding / conveying unit 2, the platen rollers 13 of the image forming units 3a to 3d, and the guide roller 20 of the paper discharging / conveying unit 4 is shown in FIG. The positioning engagement portions 28a to 28f are arranged so that the mounting track is curved in the direction opposite to the mounting direction, that is, the conveyance locus is curved upward, and the angle θ as shown in FIG. The platen roller 13 is wound around (= about 1 ° to 10 °).

 In the case of an image forming apparatus that conveys continuous recording paper 1, the recording locus of the recording paper 1 is arranged so as to be curved in the direction opposite to the mounting direction of the ink head 12. This controls the tension applied in the conveyance direction of the paper 1 between the infeed roller 5 of the paper feed conveyance unit 2 and the outfeed roller 18 of the paper discharge conveyance unit 4 to a predetermined value (for example, about 10 kgf to 20 kgf), A small angle θ (= about 1 ° to 10 °) is applied to the platen roller 13 to prevent the paper sagging between the platen rollers 13 due to the tension of the paper 1 and to ensure that the paper 1 and the platen roller 13 are in contact with each other. By winding the paper 1 within the range, a gap G between the paper 1 and the ink head 12 is secured. Therefore, by positioning the platen rollers 13 as in the present invention, the platen rollers 13 of the image forming units 3 can be arranged with high accuracy.

 Although FIG. 3A shows the alignment member 22 used when four image forming units 3 are connected, the length and the alignment engaging portion 28 according to the number of connected image forming units 3. The alignment members 22 having different numbers are prepared. FIG. 3B shows an alignment member 22 used when two image forming units 3 are connected.

 FIG. 3C shows another example of the alignment member 22. In the example of FIGS. 3A and 3B, all of the alignment engaging portions 28 have a hole shape, but in the example of FIG. 3C, the guide roller 7 of the paper feed unit 2 is provided. In addition, in order to engage with the guide roller 20 of the paper discharge conveyance unit 4, cut-in position engaging portions 28g and 28h are formed.

 As shown in FIG. 2, the alignment member 22 is installed on both the front surface and the back surface of the image forming apparatus, and both end portions of each roller are engaged with the alignment member 22 so as to align each other.

FIG. 4 is a perspective view showing a state in which the ink head 12 and the platen roller 13 are arranged on the same unit frame 14.
As shown in the figure, both end shaft portions of the platen roller 13 are rotatably supported between a front wall 14a and a rear wall 14b of a unit frame 14 having a U-shaped side surface. A rail 17 is installed between the front wall 14 a and the rear wall 14 b of the unit frame 14, and a head base 27 in which four ink heads 12 are installed in parallel is mounted on the rail 17. The ink head 12 is movable to the maintenance mechanism 8 (see FIG. 6) by a rail 17 for a maintenance operation (wiping, ink ejection detection, etc.).

 In the case of an ink jet printer, the influence of the ink droplet merging and the air flow of the recording paper (web) 1 has a great influence on the print quality, so the gap G between the ink head 12 and the platen roller 13 is important. Therefore, as shown in FIG. 4, in the assembly stage, the height adjustment unit 21 for adjusting the height of the rail 17 on which the head base 27 of the ink head 12 is mounted and the position adjustment of the platen roller 13 are carefully performed.

 The gap G between the ink head 12 and the platen roller 13 and the distance between the platen roller 13 are already adjusted at the stage of assembling the unit frame 14, and after the adjustment, they are mounted on the image forming units 3a to 3d.

 FIG. 5 is a perspective view of the image forming unit 3. The unit frame 14 shown in FIG. 4 is placed inside a unit base 15 having a U-shaped side surface. A vertically long guide hole 16 is formed at a position facing the platen roller 13 on the front wall 15 a and the rear wall 15 b of the unit base 15. The lateral width of the guide hole 16 is designed to be slightly longer than the shaft diameter of the platen roller 13 so as not to restrict the rotation of the platen roller 13, and the shaft end of the platen roller 13 protrudes from the guide hole 16. Within this range, the unit frame 14 can move up and down. The base frame 26 is provided with a fixing member (not shown) that can fix the unit frame 14 at an arbitrary position.

Next, a method for connecting the units will be described.
First, the image forming units 3a to 3d on which the ink cassettes 10 and the ink heads 12 of the respective colors are mounted, and the paper discharge transport unit 4 at the end are roughly arranged adjacent to each other with the paper feed transport unit 2 at the top. Thereafter, the levels of the paper feed transport unit 2 and the paper discharge transport unit 4 are adjusted, and the levels are adjusted so that the guide roller 7 of the paper feed transport unit 2 and the guide roller 20 of the paper discharge transport unit 4 are parallel. The guide rollers 7 and 20 on both sides are positioned at appropriate positions.

 Next, the alignment members 22 are arranged on the front and rear surfaces of the image forming units 3a to 3d, and both end shaft portions of the platen rollers 13 protruding from the image forming units 3a to 3d are engaged for alignment of the alignment members 22. Insert into the sections 28c-28f. Subsequently, the guide roller 7 of the paper feeding / conveying unit 2 is inserted into the positioning engaging portion 28a of the positioning member 22, and the guide roller 20 of the paper discharging / conveying unit 4 is inserted into the positioning engaging portion 28b of the positioning member 22. The one end of the alignment member 22 is detachably fixed to the paper feed conveyance unit 2, and the other end of the alignment member 22 is detachably fixed to the paper discharge conveyance unit 4.

 As a result, the assembly such as the ink head 12, the platen roller 13, and the unit frame 14 of each of the image forming units 3 a to 3 d shown in FIG. 4 is supported by the alignment member 22 and automatically positioned within the range of the guide hole 16. Adjustments are made. That is, the positioning of the platen roller 13 of each of the image forming units 3a to 3d can be easily performed by the single alignment member 22 with reference to the guide roller 7 of the paper feeding and conveying unit 2 and the guide roller 20 of the paper discharging and conveying unit 4. And it is done accurately. That is, the positions of the guide rollers 7 and 20 and the platen rollers 13 are appropriately arranged along the positions of the alignment engaging portions 28a to 28f of the alignment member 22 shown in FIG. 3A, for example. Become.

 For example, as shown in FIG. 10, when the connecting positions of the image forming units 3 a to 3 d connected by twisting of the image forming unit 3 are insufficient, in this embodiment, as shown in FIG. 2, the platen roller on the unit frame 14 is used. 13 is inserted into the alignment engaging portion 28 of the alignment member 22 through the guide hole 16 of the unit base 15. At this time, since the unit frame 14 can move within the range of the guide hole 16 together with the platen roller 13, the level where the guide roller 7 and the guide roller 20 are inserted regardless of the case connection direction. The entire unit frame 14 is positioned by the alignment member 22. The shafts of the platen rollers 13 of all the connected image forming units 3 a to 3 d, the guide rollers 7 of the paper feed unit 2, and the guide rollers 20 of the paper discharge transport unit 4 are aligned engaging portions of the alignment member 22. When all of the platen rollers 13 are inserted, the alignment of the platen roller 13 is completed.

 As described above, the guide roller 7 of the paper feeding unit 2 and the guide roller 20 of the paper discharge / conveyance unit 4 and the platen roller 13 of each of the image forming units 3a to 3d are not a connecting accuracy of the housing but a single alignment member. Therefore, even when the connecting position of the casing is insufficient due to, for example, twisting of the base frame 26 as shown in FIG. 6, the connecting accuracy of the casing as shown in FIG. Regardless of this, it can be arranged with high accuracy.

Further, since the ink head 12 and the platen roller 13 are arranged on the same frame 14, the gap G between the platen roller 13 and the ink head 12 can be kept constant. Further, since the conveyance locus of the paper 1 traveling on the platen roller 13 is curved in the direction opposite to the mounting direction of the ink head 12, the paper 1 is surely in contact with the platen roller 13 and the paper 1 is meandered and wrinkled. Can be prevented.

 FIG. 1B is a schematic configuration diagram of an image forming apparatus 202 according to the second embodiment of the present invention. In the case of the present embodiment, two image forming units 3e and 3f are interposed between the paper feed transport unit 2 and the paper discharge transport unit 4, and the color arrangement of ink in the first image forming unit 3e is Y. -YM-M, the color arrangement of the ink in the second image forming unit 3f is C-C-K-K, and two colors are printed by one image forming unit 3. As a result, the number of image forming units 3 is reduced as compared with FIG.

 In this case, the alignment member 22 shown in FIG. 3B is used for the alignment of the platen roller 13. If the alignment member 22 is aligned and connected and fixed in the same manner as described above, each platen roller 13 becomes a guide roller. 7 and 20 can be aligned with high accuracy. If an alignment member 22 corresponding to the number of connected image forming units 3 as shown in FIGS. 3A and 3B is prepared in advance, even after the image forming apparatus is introduced, there are local requests and requests. Accordingly, the connection configuration can be freely changed. For example, an image forming apparatus is configured with a configuration in which the number of image forming units 3 installed is reduced in accordance with the amount of printing work, or an image forming apparatus with higher image quality and higher speed by adding image forming units 3 to the contrary. An image forming apparatus having functions and expandability according to requirements can be provided as appropriate.

Next, operational effects according to the claims will be described as follows.
According to the first aspect of the present invention, there is provided a paper feeding / conveying unit having a recording medium conveying guide roller and a recording medium conveying guide roller from the upstream side toward the downstream side in the conveying direction of the recording medium. In an image forming apparatus configured by connecting a plurality of image forming units and a paper discharge transport unit having a recording medium transport guide roller,
An alignment member that extends from the paper feed conveyance unit to the paper discharge conveyance unit and that forms an alignment portion that engages with each guide roller;
Engage the end portions of the guide rollers with the alignment portions of the alignment members,
The position of the guide roller of the image forming unit with respect to the guide roller of the paper feed transport unit and the paper discharge transport unit by the alignment member based on the position of the guide roller of the paper feed transport unit and the guide roller of the paper discharge transport unit Because it is configured to align, it is possible to align the position of the guide rollers of the paper feed transport unit and paper discharge transport unit with the guide rollers of each image forming unit with high accuracy regardless of the connection accuracy of the housing. Is possible.

 In the invention according to claim 2, since the alignment member has a plate shape and the two alignment members support both ends of each guide roller of the image forming unit. The function of the alignment member can be reliably exhibited without making the device wide.

 According to a third aspect of the present invention, the guide roller and the image forming means in the image forming unit are installed on a unit frame, and the gap between the guide roller and the image forming means is kept constant. A vertically long guide portion is formed at a position facing the guide roller on the front wall and the rear wall of the unit base, and an end portion of the guide roller passes through the guide portion and Since it is configured to engage with the alignment portion, the alignment between the guide rollers can be performed by the alignment member while keeping the gap between the guide roller and the image forming means constant.

 According to a fourth aspect of the present invention, the image forming means in the image forming unit is an ink head, and the guide roller in the image forming unit is a platen roller. It is possible to provide an ink jet image forming apparatus that can align the guide rollers of the paper transport unit and the paper discharge transport unit with the positions of the platen rollers of each image forming unit with high accuracy.

 In the invention according to claim 5, since the alignment state of the alignment portions on the alignment member is curved so that the central portion protrudes upward, the recording medium is surely guided by the brewing unit. It is possible to prevent meandering and wrinkling of the recording medium while being in contact with the roller.

The invention according to claim 6
A gap adjusting step in which a guide roller and an image forming unit constituting the image forming unit are installed on a unit frame, and a gap between the guide roller and the image forming unit is adjusted and held constant;
Out of the alignment portions of the alignment members, each of which is formed with an alignment portion that engages with each of the guide rollers, an end portion of each guide roller of the image forming unit is aligned with the alignment portion corresponding to the guide roller of the image forming unit. And then engaging the end portions of the guide rollers of the paper feed / conveyance unit with the alignment portions corresponding to the guide rollers of the paper feed / conveyance unit respectively. The ends of the guide rollers of the paper discharge conveyance unit are engaged with the corresponding alignment portions, one end of the alignment member is attached to the paper feed conveyance unit, and the other end of the alignment member is connected to the paper discharge conveyance. By having the alignment member attachment process attached to the unit ,
With the gap between the guide roller and the image forming means in the image forming unit kept constant, the guide rollers of the paper feed and discharge units and the guide rollers of each image forming unit regardless of the connection accuracy of the casing Can be aligned with high accuracy.

1: paper,
2: Paper feed unit,
3a-3f: Image forming unit,
4: Discharge transport unit,
5: Infeed roller
6: Nip roller,
7: Guide roller,
8: Maintenance mechanism part,
9: Caster,
10: Ink cassette,
12: Ink head
13: Platen roller,
14: Unit frame,
15: Unit base,
16: Guide hole,
17: Rail,
18: Outfeed roller,
19: Nip roller
20: guide roller,
21: Rail height adjustment part,
22: alignment member,
23: Power supply
24: Front frame,
25: Rear frame,
26: Base frame,
27: Head base,
28: Positioning engagement portion,
202: Image forming apparatus,
G: Gap between the platen roller and the head,

JP 2008-221500 A Japanese Patent No. 2979393 Japanese Unexamined Patent Publication No. 62-299777

Claims (6)

From the upstream side to the downstream side in the recording medium conveyance direction, a paper feeding conveyance unit having a recording medium conveyance guide roller, and one or a plurality of image forming units having a recording medium conveyance guide roller, In an image forming apparatus configured by connecting a paper discharge transport unit having a recording medium transport guide roller,
An alignment member that extends from the paper feed conveyance unit to the paper discharge conveyance unit and that forms an alignment portion that engages with each guide roller;
Engage the end portions of the guide rollers with the alignment portions of the alignment members,
The position of the guide roller of the image forming unit with respect to the guide roller of the paper feed transport unit and the paper discharge transport unit by the alignment member based on the position of the guide roller of the paper feed transport unit and the guide roller of the paper discharge transport unit An image forming apparatus characterized by performing alignment. The image forming apparatus according to claim 1.
2. The image forming apparatus according to claim 1, wherein the alignment member has a plate shape, and two alignment members support both ends of each guide roller of the image forming unit. The image forming apparatus according to claim 1.
The guide roller and the image forming means in the image forming unit are installed on a unit frame, and the gap between the guide roller and the image forming means is kept constant.
The unit frame is placed on the unit base, and a vertically long guide portion is formed at a position facing the guide roller on the front wall and the rear wall of the unit base, and an end portion of the guide roller passes through the guide portion. An image forming apparatus that engages with an alignment portion of the alignment member. The image forming apparatus according to claim 3.
An image forming apparatus, wherein the image forming means in the image forming unit is an ink head, and the guide roller in the image forming unit is a platen roller. 5. The image forming apparatus according to claim 1, wherein:
The image forming apparatus according to claim 1, wherein the alignment state of the alignment portions on the alignment member is curved so that a central portion protrudes upward. From the upstream side to the downstream side in the recording medium conveyance direction, a paper feeding conveyance unit having a recording medium conveyance guide roller, and one or a plurality of image forming units having a recording medium conveyance guide roller, In an assembling method of an image forming apparatus configured by connecting a discharge conveyance unit having a recording medium conveyance guide roller,
A gap adjusting step in which a guide roller and an image forming unit constituting the image forming unit are installed on a unit frame, and a gap between the guide roller and the image forming unit is adjusted and held constant;
The unit frame is placed on the unit base, and an image is formed by penetrating the end portion of the guide roller through a vertically long guide portion formed at a position facing the guide roller on the front wall and the rear wall of the unit base. The process of assembling the unit;
Out of the alignment portions of the alignment members, each of which is formed with an alignment portion that engages with each of the guide rollers, an end portion of each guide roller of the image forming unit is aligned with the alignment portion corresponding to the guide roller of the image forming unit. And then engaging the end portions of the guide rollers of the paper feed / conveyance unit with the alignment portions corresponding to the guide rollers of the paper feed / conveyance unit respectively. The ends of the guide rollers of the paper discharge conveyance unit are engaged with the corresponding alignment portions, one end of the alignment member is attached to the paper feed conveyance unit, and the other end of the alignment member is connected to the paper discharge conveyance. A method of assembling an image forming apparatus, comprising a step of attaching an alignment member to be attached to a unit .

Images