JP2009202394A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer which properly makes high-quality printing by suppressing a degradation of an image quality by occurrence of a roller trail. <P>SOLUTION: The printer 10, making printing with ink, is provided with: a print head 12 for discharging ink to a printing surface of a medium 50; and a roller 16b which conveys the medium 50 and comes into contact with the printing surface of the medium 50 on the upstream side from the print head 12 in the conveying direction of the medium 50, as the upstream printing surface side roller. At least a portion to come into contact with the medium 50 in the roller 16b is formed of fluororesin. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a printing apparatus.

Conventionally, in a printing apparatus such as an ink jet printer, a technique for conveying a medium using a roller has been widely used. Such a roller is provided, for example, on each of the printing surface side and the back surface side of the medium, and conveys the medium by rotating with the medium interposed therebetween. As this roller, for example, a rubber roller whose surface is formed of a rubber-based material is widely used. Also. Conventionally, regarding a roller that comes into contact with a printed portion of a medium, a configuration has been proposed in which a material that exudes from rubber or a roller mark due to retransfer or the like is prevented (see, for example, Patent Document 1).
JP-A-8-85646

  However, in recent years, due to an increase in printing accuracy that is required, for example, matters that have not been a problem in the past are becoming the cause of deterioration in printing image quality. The inventor of the present application has conducted intensive research from such a viewpoint, and has found that the contact between the roller and the medium before ink ejection may cause the printing image quality to deteriorate.

  FIG. 2 is a diagram for explaining a problem of deterioration in printing image quality, and shows a state of deterioration in image quality due to contact between the roller 20 and the medium 50. The roller 20 is a rubber roller that transports the medium 50 in the ink jet printer, and contacts the printing surface of the medium 50 on the upstream side of the ink jet head in the transport direction of the medium 50. The roller 20 is a pinch roller that rotates with the medium 50 sandwiched between a roller (not shown) provided on the back surface side of the medium 50, and rotates following the rotation of the roller on the back surface side of the medium 50. .

  In such a configuration, the inventor of the present application has found that the contact between the roller 20 and the medium 50 before applying the ink may cause deterioration in the image quality of printing, through intensive research. For example, due to the contact between the roller 20 and the medium 50 that occurs before the ink application, there may be a case where the roller mark 52 in which the color of only the portion in contact with the roller 20 changes in the medium 50 after the ink application. I found.

  Further, through further earnest research, it has been found that changes in chemical properties and surface roughness of the surface of the medium 50 due to contact with the roller 20 can be considered as the cause of such roller marks. When this occurs, for example, the ink color changes, and roller marks are generated. In addition, as another cause, it has been found that static electricity is generated in a portion of the medium 50 that is in contact with the roller 20 and ink mist concentrates on the portion, thereby degrading image quality.

  Therefore, in order to appropriately suppress the deterioration of the printing image quality, it is required to solve such problems and to suppress the deterioration of the image quality due to the contact between the medium and the roller before applying the ink. Accordingly, an object of the present invention is to provide a printing apparatus that can solve the above-described problems.

In order to solve the above problems, the present invention has the following configuration.
(Configuration 1) A printing apparatus that performs printing using ink, and includes a print head that discharges ink to a printing surface of a medium and a roller that conveys the medium, and is upstream of the print head in the medium conveyance direction. Then, an upstream printing surface side roller that contacts the printing surface of the medium is provided, and at least a portion that contacts the medium in the upstream printing surface side roller is formed of a fluorine-based resin.

  Since the fluorine-based resin has extremely high chemical resistance, for example, it is difficult to cause alteration to other chemical substances. Therefore, when configured in this way, for example, even if the upstream printing surface side roller comes into contact with the medium, it is difficult to cause a chemical change in the medium and hardly affect the chemical properties of the surface of the medium. In addition, since the fluororesin has non-adhesiveness and low friction, it is difficult to cause changes in the surface roughness of the medium. Furthermore, compared with the case where a rubber roller and a medium contact, for example, it is difficult to generate static electricity on the medium. As a result, the concentration of ink mist due to the generation of static electricity hardly occurs.

  Therefore, if comprised in this way, it can prevent appropriately that a roller trace will generate | occur | produce by the contact with the medium and roller before apply | coating ink, for example. In addition, this makes it possible to suppress deterioration in image quality and appropriately perform high quality printing.

  Further, such an upstream printing surface side roller is less likely to be contaminated than, for example, a rubber roller. In addition, cleaning is also simplified when dirt is attached. Therefore, with this configuration, maintenance of the medium feeding mechanism is facilitated.

  (Configuration 2) The medium is a vinyl chloride sheet. The vinyl chloride sheet may be a glossy vinyl chloride sheet, for example.

  When a vinyl chloride sheet medium is used, if a rubber roller, for example, is used as a roller that comes into contact with the printing surface of the medium upstream in the conveying direction, physical property changes on the surface of the medium and generation of static electricity will be particularly large, and image quality will deteriorate. It tends to occur. On the other hand, if comprised in this way, even if it is a case where the medium of a vinyl chloride sheet is used, degradation of an image quality can be suppressed and high quality printing can be performed appropriately.

  (Configuration 3) A roller for transporting a medium, further comprising an upstream back surface side roller in contact with the back surface of the printing surface of the medium on the upstream side of the print head in the medium transport direction, The roller rotates with the medium sandwiched between it and the upstream back surface side roller. If comprised in this way, a medium can be conveyed appropriately, suppressing deterioration of an image quality appropriately.

  The upstream printing surface side roller is, for example, a pinch roller. The upstream printing surface side roller may be a driven roller that rotates according to the rotation of the upstream back surface side roller. Moreover, it is preferable that the part which contacts a medium in an upstream back surface side roller is formed with a material with a bigger elasticity than a fluororesin. The upstream back side roller may be, for example, a rubber roller. If comprised in this way, a medium can be conveyed more appropriately.

  (Configuration 4) A printing apparatus that performs printing using ink, and includes a print head that discharges ink to a printing surface of a medium and a roller that conveys the medium, and is upstream of the print head in the medium conveyance direction. And a roller that rotates with the medium interposed between the upstream back surface side roller and the upstream back surface side roller that are in contact with the back surface of the printing surface of the medium, and on the upstream side of the print head in the medium transport direction. An upstream printing surface side roller in contact with the printing surface, and at least a portion in contact with the medium in the upstream printing surface side roller causes a chemical change in the medium more than a portion in contact with the medium in the upstream back surface side roller. It is made of a material that is difficult to generate static electricity due to contact with the medium.

  If comprised in this way, it can prevent appropriately that a roller trace will generate | occur | produce by the contact with the medium and roller before apply | coating an ink similarly to the structure 1, for example. In addition, this makes it possible to suppress deterioration in image quality and appropriately perform high quality printing. Furthermore, since it is difficult for dirt to adhere to the upstream printing surface side roller, maintenance of the medium feeding mechanism is facilitated.

  According to the present invention, for example, it is possible to appropriately suppress high-quality printing while suppressing deterioration in image quality due to generation of roller marks.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. FIG. 1 shows an example of the configuration of a printing apparatus 10 according to an embodiment of the present invention. FIG. 1A is a side view of the printing apparatus 10. FIG. 1B is a top view showing the vicinity of the roller 16 b in the printing apparatus 10. The printing apparatus 10 is an ink jet printer that performs printing using ink, and includes a print head 12, a platen 14, and a plurality of rollers 16a to 16d.

  The print head 12 is an ink jet head that ejects ink onto the printing surface of the medium 50 by an ink jet method. The print head 12 ejects ink to each position on the medium 50 by moving in the main scanning direction which is the width direction of the medium 50. The platen 14 is a table that holds the medium 50 on which the ink is ejected by the print head 12 on the upper surface.

  The plurality of rollers 16a to 16d are rollers that transport the medium 50 in the transport direction orthogonal to the main scanning direction. The plurality of rollers 16 a to 16 d convey the medium 50, thereby moving the print head 12 relative to the medium 50 in the sub-scanning direction parallel to the conveyance direction.

  Here, of the plurality of rollers 16 a to 16 d, the two rollers 16 a and 16 b are provided on the upstream side of the print head 12 in the conveyance direction of the medium 50. The roller 16a is an example of an upstream back surface side roller, and contacts the back surface of the printing surface of the medium 50 on the upstream side. In this example, the roller 16a is a paper feed roller that supplies the medium 50 onto the platen 14, and feeds the medium 50 onto the platen 14 by rotating by receiving power from a motor or the like, for example. The roller 16a may be a rubber roller, for example.

  The roller 16b is an example of an upstream printing surface side roller, and contacts the printing surface of the medium 50 on the upstream side. In this example, the roller 16b is a pinch roller and rotates with the medium 50 sandwiched between the roller 16a. The roller 16b is a driven roller and rotates according to the rotation of the roller 16a. In this example, the printing apparatus 10 includes a plurality of rollers 16b arranged in the main scanning direction, which is the width direction of the medium 50, as shown in FIG. The configuration of the roller 16b will be described in more detail later.

  The two rollers 16 c and 16 d are provided on the downstream side of the print head 12 in the conveyance direction of the medium 50. The roller 16c contacts the back surface of the printing surface of the medium 50 on the downstream side. In this example, the roller 16c is a paper discharge roller, and pulls out the medium 50 from the platen 14 by rotating by receiving power from, for example, a motor. The roller 16c may be a rubber roller, for example. The roller 16d is a pinch roller that comes into contact with the printing surface of the medium 50, and rotates on the downstream side with the medium 50 between the roller 16c and the roller 16d. The roller 16d is a driven roller and rotates according to the rotation of the roller 16c. The roller 16d may be a rubber roller, for example. The roller 16d may be the same as or similar to the roller 16b described below.

  Hereinafter, the roller 16b will be described in more detail. In this example, at least a portion in contact with the medium in the roller 16b is formed of a fluorine-based resin. The fluororesin (fluororesin) is, for example, a polymer containing F (fluorine) in the molecule. Examples of the fluororesin include PTFE (polytetrafluoroethylene), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), ETFE (tetra Fluoroethylene-ethylene copolymer) or PCTFE (polychlorotrifluoroethylene) can be used.

  The fluorine-based resin has extremely high chemical resistance and has non-adhesiveness and low friction. Therefore, for example, even when the roller 16b comes into contact with the medium 50, the chemical properties of the surface of the medium 50 are hardly affected, and the surface roughness of the medium 50 is not easily changed. Further, for example, compared to the case where a rubber roller is used instead of the roller 16b of this example, static electricity is less likely to be generated in the medium 50, so that concentration of ink mist due to the occurrence of static electricity is less likely to occur.

  Therefore, according to this example, for example, it is possible to appropriately prevent the occurrence of roller marks due to the contact between the medium 50 and the roller 16b before ink is applied. In addition, this makes it possible to suppress deterioration in image quality and appropriately perform high quality printing. Further, the roller 16b of this example is less likely to be contaminated than, for example, a rubber roller. In addition, cleaning is also simplified when dirt is attached. Therefore, according to this example, maintenance of the medium feeding mechanism is facilitated.

  Here, in this example, a vinyl chloride sheet etc. are used for the medium 50, for example. This vinyl chloride sheet may be, for example, a glossy vinyl chloride sheet. When using a vinyl chloride sheet medium 50, if a rubber roller is used as a roller in contact with the printing surface of the medium 50 upstream in the conveying direction, for example, physical property changes on the medium surface and generation of static electricity are particularly large. Deterioration in image quality is likely to occur. On the other hand, according to this example, it is possible to appropriately suppress high-quality printing while suppressing deterioration in image quality.

  Further, at least a portion in contact with the medium in the roller 16b may be formed of a material other than the fluorine resin, for example. In this case, at least a portion in contact with the medium 50 in the roller 16b is less likely to cause a chemical change in the medium 50 than a portion in contact with the medium 50 in the roller 16a, and is less likely to generate static electricity due to contact with the medium 50. Is preferably formed.

  Even in such a configuration, it is possible to appropriately prevent the occurrence of roller marks due to the contact between the medium 50 and the roller 16b before the ink is applied. In addition, this makes it possible to suppress deterioration in image quality and appropriately perform high quality printing. Furthermore, since it becomes difficult for dirt to adhere to the roller 16b, maintenance of the medium feeding mechanism is facilitated.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above embodiment. It is apparent from the description of the scope of claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

  The present invention can be suitably used for a printing apparatus, for example.

1 is a diagram illustrating an example of a configuration of a printing apparatus 10 according to an embodiment of the present invention. FIG. 1A is a side view of the printing apparatus 10. FIG. 1B is a top view showing the vicinity of the roller 16 b in the printing apparatus 10. It is a figure explaining the subject of deterioration of the image quality of printing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Printing apparatus, 12 ... Print head, 14 ... Platen, 16a, 16b, 16c, 16d ... Roller, 50 ... Medium

Claims (4)

A printing apparatus that performs printing using ink,
A print head for ejecting ink onto the printing surface of the medium;
An upstream printing surface side roller that is in contact with the printing surface of the medium on the upstream side of the print head in the conveyance direction of the medium.
The printing apparatus according to claim 1, wherein at least a portion in contact with the medium in the upstream printing surface side roller is formed of a fluorine-based resin.   The printing apparatus according to claim 1, wherein the medium is a vinyl chloride sheet. A roller for conveying the medium, further comprising an upstream back surface roller in contact with the back surface of the printing surface of the medium on the upstream side of the print head in the medium conveyance direction;
The printing apparatus according to claim 1, wherein the upstream printing surface side roller is a roller that rotates while sandwiching the medium with the upstream back surface side roller. A printing apparatus that performs printing using ink,
A print head for ejecting ink onto the printing surface of the medium;
An upstream back roller that contacts the back surface of the printing surface of the medium on the upstream side of the print head in the transport direction of the medium;
An upstream printing surface side that is in contact with the printing surface of the medium on the upstream side of the printing head in the conveyance direction of the medium, and is a roller that rotates while sandwiching the medium with the upstream back surface side roller With rollers,
At least a portion in contact with the medium in the upstream printing surface side roller is less likely to cause a chemical change in the medium than a portion in contact with the medium in the upstream back surface side roller, and static electricity due to contact with the medium is prevented. A printing apparatus characterized by being formed of a material that is difficult to generate.

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