JP6303647B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  Printing is performed by image forming means on a print medium having an adhesive surface, such as a tape or a label paper without a mount, and having no release paper on the adhesive surface (hereinafter also referred to as “linerless label paper”). 2. Description of the Related Art An image forming apparatus such as a label printer is known which is cut to a required length after printing to form a print medium piece (hereinafter also referred to as “label piece”).

  For example, it is known that a baseless label continuous body is drawn out from a baseless label continuous body supply roll wound with a baseless label continuous body, and the baseless label continuous body is guided to a printing unit via a peeling roller. (Patent Document 1).

JP 2002-284131 A

  When transporting a print medium having an adhesive surface exposed like linerless label paper, it may be transported with the adhesive surface protected by a protective member such as a belt-like member. In this case, it is necessary to use a member that suppresses the adhesiveness to the adhesive surface so that the protective member can be re-peeled from the adhesive surface. With respect to such a protective member, the adhesive surface of the printing medium is not easily slipped in a direction parallel to the surface of the protective member, but is easily peeled off in a direction perpendicular to the surface of the protective member.

  Therefore, when the print medium is conveyed while being in close contact with the protective member, there is a problem that the lift occurs, the lift cannot be eliminated, and wrinkles are generated.

  The present invention has been made in view of the above problems, and an object of the present invention is to reduce generation of wrinkles when a print medium having an adhesive surface is conveyed.

In order to solve the above-described problem, a medium transport device according to the present invention includes:
Image forming means for forming an image on a print medium drawn from the roll body;
Transporting means for protecting and transporting the adhesive surface of the print medium with a protective member,
The conveying means is
A transport rotator for transporting the print medium drawn from the roll body;
Anda guide member for supporting and guiding the protective member at a position opposed to said image forming means,
The guide member includes at least a flat part facing the image forming unit, and an inclined part that is continuous to the upstream side of the flat part in the medium conveying direction and is inclined to the opposite side of the image forming unit. ,
The printing medium and the protection member conveyed by the conveyance rotating body are conveyed along the plane portion from the inclined portion of the guide member,
A configuration in which a winding angle a around which the adhesive surface of the print medium is wound around the transport rotating body and an angle b formed by the inclined portion of the guide member with the flat surface portion have a relationship of a> b. did.

  According to the present invention, generation of wrinkles when a print medium having an adhesive surface is conveyed can be reduced.

It is explanatory drawing of an example of the image forming apparatus which concerns on this invention. It is explanatory drawing with which it uses for description of a printing medium. It is principal part plane explanatory drawing of a protection belt. It is explanatory drawing with which it uses for description of the angle (tilt angle) with respect to the flat part of the winding angle of the printing medium to the conveyance roller, and the inclined part of a guide member. It is explanatory drawing with which it uses for description of generation | occurrence | production of the wrinkle of a printing medium. It is explanatory drawing with which it uses for description of the relationship (inclination angle) with respect to the plane part of the inclination part of a guide member, and generation | occurrence | production of a wrinkle.

  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 an explanatory view of the image forming apparatus, FIG. 2 is an explanatory view for explaining a print medium, and FIG. 3 is an explanatory plan view of a main part of a protective belt.

  The image forming apparatus transports the paper supply unit 101 that feeds the print medium 2, the image forming unit 102 that is an image forming unit that forms an image on the print medium 2, and the print medium 2 facing the image forming unit 102. A transport unit 103 serving as a transport unit and a paper discharge unit 104 are provided.

  The paper supply unit 101 is loaded with a roll body 4 that is a roll of the printing medium 2 that is a linerless label paper.

  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 image forming unit 102 includes a carriage 12 on which a recording head 11 including a liquid discharge head that discharges droplets onto the print medium 2 is mounted. The carriage 12 is movably held by a guide member (not shown) and is reciprocated in a direction perpendicular to the feeding direction of the print medium 2 (in the direction perpendicular to the paper in FIG. 1).

  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.

  Further, 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 or non-contact can be used.

  In the transport unit 103, a protective belt 21 as an endless belt-like member is disposed below the recording head 11. The protection belt 21 is wound around a conveyance roller 22 as a conveyance rotation body and a driven roller 23 as a passive rotation body so as to be able to move around.

  A pressure roller 24 is disposed opposite the conveying roller 22. The print medium 2 and the protective belt 21 are sandwiched together by a rotating body pair (here, a roller pair) composed of the transport roller 22 and the pressure roller 24 and transported to the image forming area by the recording head 11. Means. Here, the adhesive surface 2b side of the printing medium 2 is held (protected) by the protective belt 21 and conveyed.

  A guide member 29 that supports and guides the protection belt 21 at a position facing the image forming unit 102 is disposed inside the protection belt 21.

  The guide member 29 is continuous to at least the height of the flat surface portion 29a continuously from the flat surface portion 29a that secures the flatness of the print medium 2 in the region facing the image forming portion 102 and the upstream side of the flat surface portion 29a in the medium conveyance direction. And an inclined portion 29b that rises.

  Further, for example, as shown in FIG. 3, the protective belt 21 is formed with a plurality (a plurality) of suction holes 21a for air suction. The number and shape of the suction holes 21a are not limited to the example shown in FIG.

  The guide member 29 disposed inside the protective belt 21 also serves as a suction chamber forming member, and is a suction unit that sucks the print medium 2 toward the surface (conveying surface) of the protective belt 21 through the suction hole 21a. A certain suction fan 27 is arranged.

  In this case, as shown in FIG. 1, in the medium transport direction, the image forming area by the recording head 11 of the image forming unit 102 is A, the area of the flat portion 29a of the guide member 29 is B, and the suckable area by the suction hole 21a is When C, the relationship is A ≦ B <C.

  Thereby, the flatness of the print medium 2 in the image forming area can be ensured.

  Here, the print medium 2 is sucked onto the protective belt 21 by suction. However, the present invention is not limited to this, and the print belt 2 is held on the protective belt 21 using the electrostatic force or the adhesiveness of the adhesive surface of the print medium. You can also

  Further, a spur roller 28 is disposed so as to face the driven roller 23.

  Further, on the upstream side of the image forming unit 102 in the medium conveyance direction, a pressure roller 25 that presses the print medium 2 toward the guide member 29 is disposed in the vicinity of the image forming unit 102.

  The paper discharge unit 104 is provided on the downstream side of the protection belt 21 with a cutter unit 31 that cuts the print medium 2 fed from the protection belt 21 into a predetermined length and prints a piece of print medium (label piece), and a paper discharge roller 32. And a spur roller 33 opposed thereto.

  In the image forming apparatus configured as described above, when an image is formed on the printing medium 2, the roll body 4 is loaded into the paper feeding unit 101 and the printing medium 2 is pulled out, while the pressure roller 24 is separated from the conveying roller 22. Retract to the position where it was moved.

  Then, the printing medium 2 is passed between the conveyance roller 22 and the pressure roller 24, the pressure roller 24 is moved in a direction in which the printing medium 2 and the protection belt 21 are pressed, and the conveyance roller 22 and the pressure roller 24 are moved. The print medium 2 and the protective belt 21 are sandwiched together.

  Thereafter, the conveyance roller 22 is rotated to convey the adhesive surface 2b of the print medium 2 with the protection belt 21 protected, and a desired image is formed by the recording head 11 of the image forming unit 102.

  The protective belt 21 is peeled from the print medium 2 on which the image is formed, and only the print medium 2 is sent to the paper discharge unit 104, cut at a required position by the cutter unit 31, and becomes a label piece, and the paper discharge roller 32 Sent out.

  Next, the winding angle of the print medium around the conveyance roller and the angle (inclination angle) of the inclined portion of the guide member with respect to the flat portion will be described with reference to FIG.

  As shown in FIG. 4, the winding angle “a” around the conveyance roller 22 that is the conveyance rotation body of the print medium 2 and the angle “b” formed by the inclined portion 29 b with the flat surface portion 29 a have a relationship of a> b.

  As a result, it is possible to reduce the occurrence of wrinkles due to a gap between the print medium 2 and the protective belt 21 when the print medium 2 is conveyed.

  Here, the occurrence of wrinkles on the print medium 2 will be described with reference to FIG.

  The inclined portion 29b and the flat portion 29a of the guide member 29 are continuous via the rounded portion 29c.

  On the other hand, the printing medium 2 and the protection belt 21 are pressurized and conveyed by the conveyance roller 22 and the pressure roller 24, and then conveyed together to the image forming area in a close contact state.

  At this time, the protective belt 21 side of the print medium 2 is the adhesive surface 2 b, and a large frictional force is generated between the print medium 2 and the protective belt 21, so that the print medium 2 hardly moves along the surface of the protective belt 21.

  Here, if the radius of the round shape portion 29c is r29, the radius of the protective belt 21 is r21, and the radius of the printing medium 2 is r2, the protective belt 21 and the printing medium 2 have their own thicknesses. The relationship is r29 <r21 <r2.

Considering the length in the transport direction from the relationship of the radius,
The round shape portion 29c of the guide portion 29 <protective belt 21 <printing medium 2
It becomes.

  As described above, when the print medium 2 and the protection belt 21 that have passed through the rounded shape portion 29c in a state where the length does not match in the transport direction enter the flat portion 29a of the guide member 29, the print medium 2 and the protection belt in the flat portion 29a. Accordingly, the print medium 2 having a long length is peeled off from the surface of the protective belt 21 to generate an upward convex portion 202a.

  If printing is performed in this state, printing disturbance will occur. When the convex portion 202a is large, rubbing with the recording head 11 may occur.

  If there is a pressure roller 25 on the downstream side of the round-shaped portion 29 c, if the pressure roller 25 is pressed as it is, the wrinkles 202 b are generated on the print medium 2.

  That is, the print medium 2 is lifted from the protection belt 21 due to a difference in curvature between the protection belt 21 and the print medium 2 in the rounded portion 29c, and wrinkles are generated.

  Here, the generation of this wrinkle is caused by setting a> b as the relationship between the angle a around which the printing medium 2 is wound around the conveyance roller 22 that is the conveyance rotation body and the angle b formed by the inclined portion 29b with the flat surface portion 29a. Can be suppressed.

  When the above relationship is satisfied, the difference in length between the print medium 2 and the protection belt 21 is proportional to the change angle in the conveyance direction, so that the winding portion around the conveyance roller 22 is larger. In this state, the print medium 2 and the protective belt 21 are pressed and pressed together by the pressure roller 24 so as to be integrated with each other, so that the difference in length between the print medium 2 and the protective belt 21 is smaller than this. Even if it passes through the round shape portion 29c, peeling does not occur, and generation of wrinkles can be suppressed.

  Here, the evaluation result about the angle b and the generation | occurrence | production of a wrinkle with respect to the plane part 29a of the inclined part 29b of the guide member 29 is shown in FIG. At this time, the winding angle “a” of the printing medium 2 around the conveyance roller 22 which is a conveyance rotation body is set to 35 °.

  As can be seen from the results of FIG. 6, when the angle b is increased, that is, when the conveyance direction change angle of the print medium 2 at the rounded portion 29c is increased, the print medium 2 is likely to float and wrinkles are likely to occur. From this evaluation result, the angle b is preferably set to 30 ° or less.

  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 applies an image having no meaning such as a pattern to the medium (for example, simply It also means that a droplet is landed on a medium).

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

2 Print medium 4 Roll body 11 Recording head 21 Protective belt (protective member)
22 Conveying roller (conveying rotating body)
24 Pressure roller 101 Paper feed unit 102 Image forming unit 103 Transport unit 104 Paper discharge unit

Claims (6)

Image forming means for forming an image on a print medium drawn from the roll body;
Transporting means for protecting and transporting the adhesive surface of the print medium with a protective member,
The conveying means is
A transport rotator for transporting the print medium drawn from the roll body;
Anda guide member for supporting and guiding the protective member at a position opposed to said image forming means,
The guide member includes at least a flat part facing the image forming unit, and an inclined part that is continuous to the upstream side of the flat part in the medium conveying direction and is inclined to the opposite side of the image forming unit. ,
The printing medium and the protection member conveyed by the conveyance rotating body are conveyed along the plane portion from the inclined portion of the guide member,
A winding angle a where the adhesive surface of the print medium is wound around the transport rotating body and an angle b formed by the inclined portion of the guide member with the flat surface portion have a relationship of a> b. An image forming apparatus. The image forming apparatus according to claim 1, wherein the protection member is a belt-like member that wraps around the conveyance rotating body and a driven rotating body and moves around. The protective member is provided with a suction hole for air suction,
In the media transport direction,
An image forming area by the image forming means is A,
The area of the planar portion of the guide member is B,
When the suckable area by the suction hole is C,
A ≦ B <C
The image forming apparatus according to claim 1, wherein the image forming apparatus has a relationship of: The image forming apparatus according to claim 1, wherein an angle b formed by the inclined portion of the guide member and the flat portion is 30 ° or less.   The roll body is disposed at a position lower than the transport rotary body,
  The planar portion of the guide member is disposed at a position higher than the transport rotating body.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   Image forming means for forming an image on a print medium drawn from the roll body;
  Transporting means for protecting and transporting the adhesive surface of the print medium with a protective member,
  The conveying means is
  A transport rotating body for transporting the print medium drawn from the roll body in a state protected by the protective member;
  A guide member that supports and guides the protection member at a position facing the image forming unit,
  The guide member includes at least a flat part facing the image forming unit, and an inclined part that is continuous to the upstream side of the flat part in the medium conveying direction and is inclined to the opposite side of the image forming unit. ,
  A winding angle a where the adhesive surface of the printing medium is wound around the transport rotating body and an angle b formed by the inclined portion of the guide member with the flat surface portion have a relationship of a> b.
An image forming apparatus.

Images