JP2015168207A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems, for example, when a print medium is transported by supporting it with a rib, an end part of the print medium is deviated from the rib and falls from the rib, due to transport accuracy, resulting in image failure on the end part.SOLUTION: An image formation device comprises a transport guide member 27 for supporting and guiding a print medium 2 which faces an image formation part 102 and is transported. The transport guide member 27 comprises; plural first ribs 28 for supporting the print medium 2; and support parts 29, 29 for supporting end parts of the print medium 2 in a direction orthogonal to a medium transport direction. The support part 29 is formed of a width wide rib 29A in which width (width in a direction orthogonal to the medium transport direction) is wider than that of the first rib 28, and the support part 29 has a contact area with the print medium 2 wider than a contact area with the print medium 2 and the first rib 28.

Description

  The present invention relates to an image forming apparatus.

  Printed on a roll-shaped print medium (hereinafter also referred to as “linerless label paper”) that has an adhesive surface and does not have a release paper on the adhesive surface, such as tape and label paper without backing paper. There is known an image forming apparatus such as a label printer that is cut into a length of 2 to obtain a print medium piece (hereinafter also referred to as “label piece”).

  As a conventional image forming apparatus, there is known an apparatus in which a print medium is guided by a conveyance guide member such as a platen member, and the conveyance guide member is provided with a plurality of ribs for supporting the print medium (Patent Document 1).

JP 2001-315993 A

  By the way, when a printing medium having a particularly adhesive surface such as a linerless label sheet is guided by the conveyance guide member, it is preferable to reduce the conveyance resistance by reducing the contact area between the print medium and the conveyance guide member. For this purpose, it is preferable to narrow the width of the ribs that support the print medium and widen the interval between the ribs.

  However, when the rib width is narrowed and the rib interval is widened in this way, particularly when the conveyance accuracy in the medium width direction is poor, the end in the direction perpendicular to the print medium conveyance direction (medium width direction) Is shifted in the width direction and hangs down without being placed on the rib, causing a problem of image formation failure at the end.

  The present invention has been made in view of the above problems, and an object of the present invention is to ensure the flatness of the edge of a print medium during image formation and reduce the occurrence of image defects.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
Image forming means for forming an image on a print medium;
A conveyance guide member that guides the print medium facing the image forming unit,
In the conveyance guide member,
A plurality of first ribs for supporting the print medium;
A support portion for supporting an end portion of the print medium in the medium conveyance direction,
The support portion is configured to have a larger contact area with the print medium than the first rib.

  According to the present invention, it is possible to ensure the flatness of the edge of the print medium during image formation and reduce the occurrence of image defects.

FIG. 2 is a front explanatory view of a mechanism unit of an example of an image forming apparatus according to the present invention. It is principal part front explanatory drawing with which it uses for description of a printing medium. It is a perspective explanatory view of the conveyance guide member in a 1st embodiment of the present invention. It is a perspective explanatory view of the conveyance guide member in a 2nd embodiment of the present invention. It is a perspective explanatory view of a conveyance guide member in a 3rd embodiment of the present invention. It is a perspective explanatory view of a conveyance guide member in a 4th embodiment of the present invention. It is a perspective explanatory view of a conveyance guide member in a 5th embodiment of the present invention. Similarly it is principal part plane explanatory drawing. It is sectional explanatory drawing which follows the BB line of FIG. It is a perspective explanatory view of a conveyance guide member in a 6th embodiment of the present invention. It is a perspective explanatory view of a conveyance guide member in a 7th embodiment of the present invention. It is a perspective explanatory view of a conveyance guide member in an 8th embodiment of the present invention. It is principal part plane explanatory drawing of the conveyance guide member in 9th Embodiment of this invention. It is explanatory drawing which looked at the conveyance guide member from the upstream. It is principal part plane explanatory drawing of the conveyance guide member in 10th Embodiment of this invention. It is a plane explanatory view of a conveyance guide member in an 11th embodiment of the present invention. It is principal part front explanatory drawing of the conveyance part of the image forming apparatus which concerns on 12th Embodiment of this invention. It is a principal plane explanatory drawing of a conveyance guide member similarly. It is principal part plane explanatory drawing of the conveyance guide member which concerns on 13th Embodiment of this invention. It is a cross-sectional explanatory drawing along the medium conveyance direction of the support part of the conveyance guide member. It is a perspective explanatory view of the conveyance guide member concerning a 14th embodiment of the present invention. It is a perspective explanatory view of the conveyance guide member concerning a 15th embodiment of the present invention. It is a perspective explanatory view of the conveyance guide member concerning a 16th embodiment of the present invention. It is a principal front explanatory view of a conveyance section of an image forming apparatus according to a seventeenth embodiment of the present invention. It is a plane explanatory drawing similarly. It is a cross-sectional explanatory drawing along the conveyance direction of a support part. It is principal part plane explanatory drawing of the conveyance guide member which concerns on 18th Embodiment of this invention. It is principal part plane explanatory drawing of the conveyance guide member which concerns on 19th Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an example of an image forming apparatus according to the present invention will be described with reference to FIGS. FIG. 1 is a front explanatory view of a mechanism part of the image forming apparatus, and FIG. 2 is a front explanatory view of a main part for explaining a print medium.

  In the image forming apparatus, a sheet feeding unit 101 serving as a sheet feeding device, an image forming unit 102 serving as an image forming unit, a transport unit 103 serving as a transport unit, and a discharge unit serving as a paper discharge transport unit are included in the apparatus main body 100. And a paper transport unit 104. Further, a discharge port 105 is provided as a discharge port portion for discharging the print medium 2 on which an image is formed to the outside of the apparatus main body 100, and guide means for guiding the roll-shaped print medium 2 when the print medium 2 is transported and pulled back. 106.

  A roll body 4 in which the print medium 2 is wound in a roll shape is loaded in the paper supply unit 101.

  Here, as shown in FIG. 2, the printing medium 2 has an adhesive layer (hereinafter referred to as “adhesive surface”) 2b on one surface of a medium (hereinafter also referred to as “printing surface”) 2a capable of forming an image. It is a continuum formed. And this printing medium 2 is the linerless label paper made into the roll shape in the state which has not affixed the mount (release paper, separator) on the adhesive surface 2b.

  The roll body 4 is fitted into a spool 5, and the spool 5 is a first roller 111, a second roller 112, and a third roller 113, which are first to third rotating bodies arranged at both ends on the roll holder member 6. It is held rotatably at three points.

  In the present invention, the “spool” is not limited to a member that is provided separately from the core member and is used by being fitted into the core member. 4 may be formed integrally with the core member. Further, when the core member of the roll body 4 is directly held, such a core member is also included in the “spool”.

  The image forming unit 102 includes a carriage 12 on which a recording head 11 including a liquid discharge head as an image forming unit that discharges droplets onto the print medium 2 is mounted. The carriage 12 is movably held by the main guide member 13 and the sub-guide member 14 and is reciprocated in a direction (main scanning direction) perpendicular to the transport direction of the print medium 2. As a result, the recording head 11 can reciprocate.

  Here, the recording head 11 is a liquid ejection head having two nozzle rows, and the two recording heads 11 are mounted on the carriage 12. The four nozzle rows of the two recording heads 11 eject ink droplets of black (K), cyan (C), magenta (M), and yellow (Y), respectively. However, the present invention is not limited to this, and a line-type head can also be used.

  Ink supply to the recording head 11 is performed by supplying ink of a required color from an ink cartridge 15 that is replaceably mounted to the apparatus main body 100 to a head tank (not shown) mounted on the carriage 12 via a supply tube 16. In this method, ink is supplied from the head tank to the recording head 11.

  Further, ink waste liquid generated by a maintenance operation for maintaining and recovering the performance of the recording head 11 is discharged and stored in a waste liquid tank 17 that is replaceably attached to the apparatus main body 100.

  The image forming unit 102 is not limited to the form of the liquid ejection head, and various image forming units that form an image in contact and non-contact can be used.

  The conveyance unit 103 sends the upstream rotating member pair including the conveyance roller 22 and the opposing roller 24 that are fed toward the image forming unit 102 with the print medium 2 interposed therebetween, and sends the print medium 2 on which the image is formed to the downstream side. A downstream rotating body pair including a paper discharge roller 23 and a pressure roller 25 is provided.

  A conveyance guide member 27 that guides the print medium 2 to face the recording head 11 is disposed between the conveyance roller 22 and the opposing roller 24, the paper discharge roller 23, and the pressure roller 25.

  The paper discharge transport unit 104 cuts the print medium 2 to a desired length on the downstream side in the transport direction of the receiving member 30 that guides the print medium fed from between the paper discharge roller 23 and the pressure roller 25. A cutter unit 31 serving as a cutting means for forming a print medium piece (label piece) 200 is disposed.

  The cutter unit 31 has a lower blade 31b formed on the downstream end surface of the receiving member 30 that receives the print medium 2, and a cutting blade (upper blade: cutter) 31a that cuts the print medium 2 between the lower blade. Then, the cutter 31a moves in a direction orthogonal to the transport direction, thereby cutting the print medium 2.

  A discharge roller 32 and a spur roller 33 facing the discharge roller 32 are disposed on the downstream side of the cutter unit 31. The discharge roller 32 and the spur roller 33 hold the leading end of the label piece 200 that has been cut by the cutter unit 31 in a state of being sent to the discharge port 105 that is a discharge port portion of the apparatus main body 100.

  Here, the surface holding the label piece 200 of the discharge roller 32 is subjected to, for example, a non-adhesive process (a process in which the adhesive surface does not adhere) so that the adhesive surface 2b of the label piece 200 can be peeled off. In this case, the discharge roller 32 itself can be formed of a peelable material.

  In addition, a paper sensor 34 that detects the presence or absence of the print medium 2 is disposed. The paper sensor 34 can be constituted by a photo sensor or a combination of a mechanical lever and a photo sensor.

  The guide means 106 includes a second roller 42 serving as a separation roller disposed on the upstream side of the image forming unit 102 on the downstream side of the opposing roller 24 that also serves as the first roller constituting the conveying unit 103, and the opposing roller 24. And a third roller 43 disposed on the opposite side of the second roller 42, and an endless guide belt 44 is hung between the opposing roller 24, the second roller 42, and the third roller 43. It is turning.

  Here, the guide belt 44 is, for example, a belt-like member that uses polyimide as a base material and has a release layer (for example, silicone coating) on the surface layer to improve the release property from the adhesive surface 2 b of the printing medium 2.

  The counter roller 24, the second roller 42, and the third roller 43 are rotatably held by the holder member 45. The holder member 45 is disposed so as to be rotatable about a shaft 46. The holder roller 45 is positioned so that the opposing roller 24 faces the conveying roller 22, and the opposing roller 24 is separated from the conveying roller 22 between the opposing roller 24 and the conveying roller 22. It is possible to displace it from the position where it is opened.

  When the roll body 4 is loaded and the print medium 2 is set, the gap between the opposing roller 24 and the transport roller 22 is opened, and when the print medium 2 is transported, the counter roller 24 is pressed against the transport roller 22 side. Therefore, the opposing roller 24 is pressurized toward the conveying roller 22 by a pressing means such as a spring.

  In the present embodiment, as described above, the image forming is described with the adhesive surface 2b of the print medium 2 facing the conveyance guide member 27. However, the image forming is performed on the adhesive surface 2b of the print medium 2. It can also be. In this case, it is preferable to perform a non-adhesive treatment (a treatment in which the adhesive surface does not adhere) on the surface of the guide belt 44 described above.

  In the image forming apparatus configured as described above, the print medium 2 drawn out from the roll body 4 loaded in the paper feeding unit 101 is sandwiched between the transport roller 22 and the opposing roller 24. By rotating the transport roller 22, the print medium 2 is transported while being guided by the transport guide member 27, and a desired image is formed by the recording head 11 of the image forming unit 102.

  The printing medium 2 on which the image is formed is sent to the paper discharge conveyance unit 104 between the paper discharge roller 23 and the pressure roller 25, and is cut at a required position by the cutter unit 31 to become a label piece 200. And the spur roller 33 are held in a state where they can be extracted from the discharge port 105 of the apparatus main body 100.

  Further, the guide means 106 prevents the print medium 2 from being caught in the opposing roller 24 at the time of conveyance and pullback, particularly when an image is formed on the adhesive surface 2b side of the print medium 2.

  In other words, even if the surface of the opposing roller 24 is non-adhesive, the adhesive roller 2b of the printing medium 2 is stuck to the peripheral surface of the opposing roller 24 only by the opposing roller 24 because the curvature of the opposing roller 24 is small. There is a possibility of getting involved. In this case, it is only necessary to increase the curvature of the opposing roller 24. However, in this case, the area of the nip region between the opposing roller 24 and the conveying roller 22 is reduced, and a stable conveying force cannot be obtained.

  Therefore, during conveyance, the printing medium 2 is conveyed while being pressed by the guide belt 44, and the guide belt 44 is reliably separated from the printing medium 2 by the second roller 42 serving as a separation roller having a large curvature, so that the opposing roller during conveyance 24 is prevented from being caught.

  Also, when the print medium 2 is pulled back, the adhesive surface 2 b side of the print medium 2 is received by the guide belt 44 to prevent the print medium 2 from being caught by the counter roller 24.

  At the stage where the image formation is completed and the print medium 2 is cut by the cutter unit 31, the tip of the print medium 2 is at the position of the cutter unit 31, and the area facing the image forming unit 102 of the print medium 2 is unused. It becomes an area. If the next image forming operation is resumed, the unused area of the print medium 2 is wasted. Therefore, the print medium 2 is pulled back in the pull-back direction (the direction opposite to the transport direction) to a position where the front end of the print medium 2 is in front (upstream side) of the image forming unit 102.

  Next, the conveyance guide member in 1st Embodiment of this invention is demonstrated with reference to FIG. FIG. 3 is a perspective explanatory view of the conveyance guide member.

  The transport guide member 27 includes a plurality of first ribs 28 that support the print medium 2, and support portions 29 and 29 that support end portions of the print medium 2 in a direction orthogonal to the medium transport direction.

  The support portion 29 has a larger contact area with the print medium 2 than the first rib 28. Here, the support portion 29 is configured by a wide rib 29 </ b> A having a width (width in a direction orthogonal to the medium conveyance direction) wider than the width of the first rib 28.

  Since it comprised in this way, even if the conveyance precision of the printing medium 2 falls, the both ends of the printing medium 2 are reliably supported by the support part 29, and are prevented from dripping.

  Accordingly, the flatness of the edge of the print medium during image formation is ensured, and the occurrence of image defects is reduced.

  When the linerless label paper is used as the print medium 2 and the adhesive surface 2b side is guided by the conveyance guide member 27 as described above, the portion that contacts the print medium 2 is subjected to non-adhesive treatment. It is preferable to keep it.

  Next, the conveyance guide member in 2nd Embodiment of this invention is demonstrated with reference to FIG. FIG. 4 is a perspective explanatory view of the conveyance guide member.

  The support portion 29 of the transport guide member 27 is configured by providing a plurality of third ribs 29B that cross in the medium width direction between two ribs extending in the medium transport direction.

  Since it comprised in this way, while supporting the both ends of the printing medium 2 with the support part 29 reliably, the contact area of the printing medium 2 and the support part 29 becomes smaller than 1st Embodiment, and a conveyance load can be reduced.

  At this time, the third rib 29B may be arranged so as to be orthogonal to the medium conveyance direction, but as shown in FIG. 4, it is arranged so as to be inclined in a direction extending from the upstream side toward the downstream side in the medium conveyance direction. It is preferable. By inclining in this way, when the leading edge of the print medium is conveyed, it becomes difficult to be caught by the third rib 29B, the occurrence of jam is suppressed, and the conveyance stability is improved.

  Next, the conveyance guide member in 3rd Embodiment of this invention is demonstrated with reference to FIG. FIG. 5 is an explanatory perspective view of the conveyance guide member.

  The support portion 29 of the transport guide member 27 is configured by arranging a plurality of rollers 29C, which are rotatable members having an axis in the direction intersecting the medium transport direction, arranged in the medium transport direction.

  Since it comprised in this way, while being able to support the both ends of the printing medium 2 reliably by the support part 29, the conveyance load of a paper width direction edge part can further be reduced because the roller 29C rotates.

  Next, the conveyance guide member in 4th Embodiment of this invention is demonstrated with reference to FIG. FIG. 6 is an explanatory perspective view of the conveyance guide member.

  The support portion 29 of the conveyance guide member 27 is configured by a rib group in which a plurality of second ribs 29 </ b> D are arranged at a higher density than the first ribs 28.

  Since it comprised in this way, while supporting the both ends of the printing medium 2 with the support part 29 reliably, the contact area of the printing medium 2 and the support part 29 becomes smaller than 1st Embodiment, and a conveyance load can be reduced. Also, the leading edge of the print medium is not caught by the ribs and the conveyance is stabilized.

  Next, the conveyance guide member in 5th Embodiment of this invention is demonstrated with reference to FIG. 7 is an explanatory perspective view of the conveyance guide member, FIG. 8 is an explanatory plan view of the main part, and FIG. 9 is an explanatory sectional view taken along line BB in FIG.

  In the present embodiment, a chamfer 29Ba is formed on the upstream side of the third rib 29B in the medium conveying direction in the second embodiment.

  Thereby, it can prevent more reliably that the front-end | tip of the printing medium 2 catches on the 3rd rib 29B, and a conveyance defect generate | occur | produces.

  Next, the conveyance guide member in 6th Embodiment of this invention is demonstrated with reference to FIG. FIG. 10 is an explanatory perspective view of the conveyance guide member.

  In the present embodiment, the second rib 29D in the fourth embodiment is formed only in the image forming area.

  Thereby, the conveyance load can be further reduced.

  Further, a chamfer is formed at the upstream end portion of the second rib 29D in the medium conveyance direction to prevent the tip of the print medium 2 from being caught.

  Next, the conveyance guide member in 7th Embodiment of this invention is demonstrated with reference to FIG. FIG. 11 is a perspective explanatory view of the conveyance guide member.

  In the present embodiment, the second rib 29D in the fourth embodiment is formed only in the image forming area, and is divided into partial areas on the upstream side and the downstream side in the medium conveyance direction within the image forming area. ing.

  Thereby, the conveyance load can be further reduced as compared with the sixth embodiment.

  Next, the conveyance guide member in 8th Embodiment of this invention is demonstrated with reference to FIG. FIG. 12 is a perspective explanatory view of the conveyance guide member.

  In the present embodiment, the support portion 29 configured by the third rib 29B of the second embodiment is provided in accordance with the end portions of the print media 2 having a plurality of widths.

  As a result, it is possible to deal with print media having a plurality of types of widths.

  Next, the conveyance guide member in 9th Embodiment of this invention is demonstrated with reference to FIG.13 and FIG.14. FIG. 13 is an explanatory plan view of a main part of the transport guide member, and FIG. 14 is an explanatory view of the transport guide member as viewed from the upstream side.

  In the present embodiment, the third rib 29B constituting the support portion 29 of the second embodiment is formed in a shape whose height increases from the upstream side toward the downstream side in the medium transport direction.

  Thereby, it can convey, scooping up the front end side of the printing medium 2, and it can reduce the folding and catching of the edge part of the printing medium 2. FIG.

  Next, the conveyance guide member in 10th Embodiment of this invention is demonstrated with reference to FIG. FIG. 15 is an explanatory plan view of a main part of the conveyance guide member.

  In the present embodiment, the third rib 29B constituting the support portion 29 of the second embodiment is the end point e of the upstream third rib 29B among the two third ribs 29B and 29B adjacent in the medium transport direction. Is located downstream of the starting point s of the third rib 29B on the downstream side.

  Thus, since the print medium 2 is supported by the downstream third rib 29B before leaving the upstream third rib 29B, the end of the print medium 2 is always supported by the third rib 29B. It is possible to prevent the edge of the medium from being bent or caught.

  Next, the conveyance guide member in 11th Embodiment of this invention is demonstrated with reference to FIG. FIG. 16 is an explanatory plan view of the conveyance guide member.

  In the present embodiment, in the configuration of the eighth embodiment, the conveyance guide member 27 is provided with a medium detection means 51 such as a photosensor at a position where the minimum print medium can be detected. Here, since one end of the print medium 2 is conveyed as a reference (paper reference), the medium detection unit 51 is arranged on the paper reference side. Further, the medium detection unit 51 is disposed on the upstream side of the conveyance guide member 27 in the medium conveyance direction in order to detect the leading edge of the print medium 2.

  Thereby, the print medium 2 can be reliably detected.

  Next, a twelfth embodiment of the present invention will be described with reference to FIGS. FIG. 17 is a front view of an essential part of a conveyance portion of the image forming apparatus according to the embodiment, and FIG. 18 is an explanatory plan view of an essential part of the conveyance guide member.

  In the present embodiment, a plurality of suction holes 51 are provided in the portion of the support portion 29 configured by the third ribs 29 </ b> B of the transport guide member 27.

  A suction means (for example, a suction fan) 52 that sucks air through the suction hole 51 of the transport guide member 27 is disposed.

  Thus, the end of the print medium 2 can be adsorbed and transported to the support unit 29 side by air suction in the region of the support unit 29 of the transport guide member 27, and the lift of the end of the print medium 2 can be prevented. Can do.

  Next, a conveyance guide member according to a thirteenth embodiment of the present invention will be described with reference to FIGS. FIG. 19 is an explanatory plan view of the main part of the transport guide member, and FIG. 20 is a cross-sectional explanatory view along the medium transport direction of the support portion of the transport guide member.

  In the present embodiment, the absorber 53 that absorbs liquid is disposed between the third ribs 29 </ b> B and 29 </ b> B on the support portion 29 configured by the third ribs 29 </ b> B of the conveyance guide member 27.

  As a result, the surplus liquid can be recovered by the absorber 53, for example, when borderless printing is performed.

  In this case, it is preferable that the surface of the third rib 29B is subjected to a liquid repellent treatment so that no ink remains on the upper surface of the rib.

  Next, a conveyance guide member according to a fourteenth embodiment of the present invention will be described with reference to FIG. FIG. 21 is a perspective explanatory view of the conveyance guide member.

  The support portion 29 of the transport guide member 27 is configured by a belt-like member 29E. The belt-like member 29E is arranged so as to be able to move around by being hung between two rollers (not shown). In this case, the belt-like member 29E is driven to rotate by frictional resistance caused by contact with the print medium 2.

  Since it comprised in this way, while supporting the both ends of the printing medium 2 with the support part 29 reliably, a conveyance load can be reduced.

  Next, a conveyance guide member according to a fifteenth embodiment of the present invention will be described with reference to FIG. FIG. 22 is an explanatory perspective view of the conveyance guide member.

  In the present embodiment, in the configuration of the fourteenth embodiment, the suction hole 61 is formed in the belt-like member 29E constituting the support portion 29.

  Then, air suction is performed through a suction hole by a suction unit (not shown) to adsorb the end of the print medium 2 to the belt-like member 29E.

  Thereby, lifting of the edge part of the printing medium 2 can also be prevented.

  Next, a conveyance guide member according to a sixteenth embodiment of the present invention will be described with reference to FIG. FIG. 23 is a perspective explanatory view of the conveyance guide member.

  In the present embodiment, the support portion 29 configured by the belt-like member 29E of the fourteenth embodiment is provided in accordance with the end portions of the print media 2 having a plurality of widths.

  As a result, it is possible to deal with print media having a plurality of types of widths.

  Next, a seventeenth embodiment of the present invention will be described with reference to FIGS. FIG. 24 is an explanatory front view of the main part of the conveying unit of the image forming apparatus according to the embodiment, FIG. 25 is an explanatory plan view, and FIG. 26 is an explanatory sectional view along the conveying direction of the supporting unit.

  In this image forming apparatus, the transport unit 103 includes a protective belt 321 that is an adhesive surface protective member formed in an endless belt shape below the recording head 11.

  The protection belt 321 is wound around the transport roller 322 and the driven roller 323 so as to be able to move around. The protective belt 321 is preferably not sticky to the adhesive surface 2b of the print medium 2, but can be re-peeled from the adhesive surface 2b to prevent the print medium 2 from floating from the protective belt 321 during transportation. It may have some weak adhesiveness.

  A pressure roller 324 is disposed so as to face the conveying roller 322. The conveyance roller 322 and the pressure roller 324 sandwich the print medium 2 and the protective belt 321 that is an adhesive surface protection member, and convey them to the image forming area by the recording head 11.

  Although not shown, the protective belt 321 is formed with a number of suction holes, and is sucked by the suction fan 337 disposed inside the protective belt 321, thereby adsorbing the print medium 2 to the protective belt 321. Note that, here, the print medium 2 is sucked to the protection belt 321 by suction. However, the present invention is not limited to this, and the print medium 2 can be sucked by electrostatic force.

  Further, a conveyance guide member 327 also serving as a platen member that supports the protection belt 321 is disposed on the back surface side of the protection belt 321.

  As shown in FIG. 25, the conveyance unit 103 has one end in the width direction (also one end in the main scanning direction) orthogonal to the conveyance direction of the print medium 2 outside the width direction end of the protection belt 321. The print medium 2 is conveyed in the positioned state.

  On the other hand, the conveyance guide member 327 is disposed up to a portion facing the portion 201 that is separated from the protection belt 321 of the print medium 2, and has a support portion 329 that supports the portion 201 that is removed from the protection belt 321 of the print medium 2. Yes.

  Here, as in the second embodiment, the support portion 329 includes a plurality of ribs 329B arranged in an inclined manner in a direction that widens from the upstream side toward the downstream side in the medium conveyance direction.

  A reading sensor 350 is disposed between the ribs 329B and 329B as reading means for reading an eye mark or the like provided on the back side of the print medium 2 in a non-contact manner. The reading sensor 350 is composed of, for example, a reflective photosensor.

  Thus, the eye mark or the like provided on the back side of the print medium 2 (the surface in contact with the protection belt 321) can be read by the reading sensor 350 while adsorbing and transporting the print medium 2 to the protection belt 321. become.

  Since the portion 201 of the print medium 2 that is removed from the protective belt 321 can be supported by the support portion 329, the end of the print medium 2 can be prevented from sagging.

  Next, a conveyance guide member according to an eighteenth embodiment of the present invention will be described with reference to FIG. FIG. 27 is an explanatory plan view of a main part of the conveyance guide member.

  In the present embodiment, a plurality of suction holes 351 are provided in a portion of the support portion 329 configured by the ribs 329B of the conveyance guide member 327 of the seventeenth embodiment.

  The above-described suction fan 337 performs air suction through the suction hole 351 of the transport guide member 327.

  As a result, the end of the print medium 2 can be adsorbed and transported to the support section 329 side by air suction in the region of the support section 329 of the transport guide member 327, and the lift of the end of the print medium 2 can be prevented.

  Next, a transport guide member according to a nineteenth embodiment of the present invention is described with reference to FIG. FIG. 28 is an explanatory plan view of a main part of the conveyance guide member.

  In the present embodiment, an absorber 353 that absorbs liquid is disposed between the ribs 329B and 329B in the portion of the support portion 329 configured by the ribs 329B of the conveyance guide member 327 of the seventeenth embodiment.

  Thereby, surplus liquid can be collect | recovered with the absorber 353. FIG.

  Note that “image formation” in the present application not only applies an image having a meaning such as a character or a figure to a medium but also an image having no meaning such as a pattern or the like (simply a droplet). To land on the medium).

  Further, the printing medium is not limited to the linerless label paper having the adhesive surface shown in the embodiment, and even a medium such as a general paper can prevent the end portion from sagging. Further, the form of the print medium is not limited to roll paper, but may be cut paper or other forms.

  Further, the image forming apparatus includes both a serial type image forming apparatus and a line type image forming apparatus, unless otherwise limited.

DESCRIPTION OF SYMBOLS 2 Print medium 4 Roll body 11 Recording head 12 Carriage 21 Protection belt 22 Conveyance roller 23 Paper discharge roller 24 Opposed roller 27 Conveyance guide member 28 1st rib 29 Support part 32 Discharge roller 100 Apparatus main body 101 Paper supply part 102 Image formation part 103 Conveying unit 104 Discharging unit 105 Discharging port 327 Conveying guide member 329 Supporting unit

Claims (20)

Image forming means for forming an image on a print medium;
A conveyance guide member that guides the print medium facing the image forming unit,
In the conveyance guide member,
A plurality of first ribs for supporting the print medium;
A support portion for supporting an end portion of the print medium in the medium conveyance direction,
The image forming apparatus according to claim 1, wherein the support portion has a larger contact area with the print medium than the first rib. 2. The image forming apparatus according to claim 1, wherein the support portion is configured by a wide rib having a width in a direction perpendicular to the medium conveyance direction as compared with the first rib. 2. The image forming apparatus according to claim 1, wherein the support portion includes a rib group in which a plurality of second ribs are arranged at a higher density than the first ribs. 2. The image forming apparatus according to claim 1, wherein the support portion includes a plurality of third ribs arranged to be inclined in a direction extending from the upstream side toward the downstream side in the medium conveyance direction. The image forming apparatus according to claim 4, wherein a chamfer is formed on the upstream side of the third rib in the medium conveyance direction. The image forming apparatus according to claim 4, wherein the height of the third rib increases from the upstream side to the downstream side in the medium conveyance direction. 5. The two third ribs that are adjacent in the medium conveyance direction are such that the end point of the third rib on the upstream side is located downstream of the start point of the third rib on the downstream side. The image forming apparatus described in 1. The image forming apparatus according to claim 1, wherein the support portion is configured by a rotatable rotating member having an axis in a direction intersecting a medium conveyance direction. The image forming apparatus according to claim 1, wherein the support portion is provided at a position corresponding to each end portion of the print medium having a different width. The image forming apparatus according to claim 1, wherein the support portion is provided only in an image forming area in the medium conveyance direction. The image forming apparatus according to claim 1, wherein a medium detection unit is disposed at a position where the minimum print medium can be detected on the conveyance guide member. A suction hole is provided in the transport guide member,
The image forming apparatus according to claim 1, further comprising a suction unit configured to suck through the suction hole. The image forming means is a liquid ejection means for ejecting droplets;
The image forming apparatus according to claim 1, wherein the support portion of the transport guide member includes a recovery unit that recovers excess liquid. The image forming apparatus according to claim 1, wherein the support portion is configured by a belt-like member. The belt-like member is provided with a suction hole,
The image forming apparatus according to claim 14, further comprising a suction unit that sucks through the suction hole. The image forming apparatus according to claim 14, wherein the belt-shaped member is provided at a position corresponding to each end of the print medium having a different width. Image forming means for forming an image on a print medium;
Conveying means including a belt-like member for conveying the printing medium,
The conveying means is
In the direction perpendicular to the medium conveyance direction, the print medium is conveyed in a state where the print medium protrudes outward from the belt-shaped member,
A transport guide member having a support portion that supports a portion of the print medium that protrudes outward from the end in the width direction of the belt-shaped member;
The image forming apparatus according to claim 1, wherein the support portion of the transport guide member includes a plurality of ribs arranged to be inclined in a direction extending from the upstream side toward the downstream side in the medium transport direction. The image forming apparatus according to claim 17, wherein a reading unit that reads a surface of the printing medium facing the belt-like member is disposed on the support portion of the conveyance guide member. A suction hole is provided in the support portion of the transport guide member,
The image forming apparatus according to claim 17, further comprising a suction unit configured to suck through the suction hole. The image forming means is a liquid ejection means for ejecting droplets;
The image forming apparatus according to claim 17, wherein the support portion of the transport guide member includes a recovery unit that recovers excess liquid.

Images