JP2008162035A - Ink image drying device and ink image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently dry an ink image formed on a paper sheet. <P>SOLUTION: This ink image drying device 3 for drying an ink image is built in an inkjet printer 1 for forming an image on a paper sheet by using ink. The ink image drying device 3 is equipped with a first paper conveyance belt 31 and a belt heating mechanism 32. The first paper conveyance belt 31 is adapted to convey a paper sheet having an ink image formed on its surface. The belt heating mechanism 32 is adapted to raise the temperature of the first paper conveyance belt 31 by directly heating the first paper conveyance belt 31. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ink image drying apparatus and an ink image forming apparatus, and in particular, an ink image drying apparatus and an ink image drying apparatus for drying an ink image disposed in an image forming apparatus of an image forming system using ink. The present invention relates to an ink image forming apparatus comprising:

  The ink image forming apparatus includes: an ink image forming unit that forms an ink image based on image information; a paper storage unit that stores paper for forming an ink image; and a sheet in the paper storage unit that conveys paper to the ink image forming unit A paper transporting unit that discharges the paper on which the ink image is formed. In this ink image forming apparatus, the paper in the paper storage unit is transported to the ink image forming unit by the paper transport unit, and the paper on which the ink image is formed in the ink image forming unit is discharged by the discharge unit.

  Here, since the ink image requires a certain period of time to dry, the ink image may be damaged if the ink image touches the ink image portion of the paper formed on the surface. In addition, for the same reason, if papers on which ink images are formed immediately after being discharged from the discharge unit are stacked, the ink adheres to the back side of the stacked sheets, and thus the sheets cannot be stacked and placed. There is.

  Therefore, an ink image forming apparatus having a mechanism for drying after forming an ink image is provided (see Patent Document 1).

In this ink image forming apparatus, an ink image is formed on a sheet by an ink image forming unit, and then the ink is dried by a drying mechanism.
JP 2004-203034 A

  In the ink image forming apparatus described in Patent Document 1, there is a description using a coil heater, a halogen heater, and electromagnetic induction heating as a drying mechanism of the ink image, but it is not described to the extent that it can be implemented, and the ink image is efficiently used. It is difficult to realize an apparatus for drying well.

  An object of the present invention is to efficiently dry an ink image formed on a sheet.

  An ink image drying apparatus according to claim 1 is an ink image drying apparatus that dries an ink image disposed in an image forming apparatus that forms an image on a sheet using ink, the ink image drying apparatus including: a first sheet conveying belt; And a belt heating mechanism. The first paper transport belt is a belt for transporting paper on which an ink image is formed. The belt heating mechanism is a mechanism that directly heats the first paper transport belt to raise the temperature of the first paper transport belt.

  In this ink image drying apparatus, the first paper transport belt is heated by the belt heating mechanism, and the paper on which the ink image is formed is transported by the first paper transport belt.

  Here, since the temperature of the first paper transport belt is raised and the paper is in contact with the first paper transport belt, heat is efficiently transferred from the first paper transport belt to the paper. For this reason, the ink image on the paper is easily dried.

  An ink image drying apparatus according to a second aspect is the ink image drying apparatus according to the first aspect, wherein the first paper transport belt has a metal portion, and the belt heating mechanism is in the vicinity of the first paper transport belt. Having an exciting coil.

  Here, the temperature of the metal part is raised by electromagnetic induction heating, and the temperature of the first paper transport belt is raised as the temperature of the metal part increases, so that the thermal efficiency is high and the temperature of the first paper transport belt is high. Easy to raise.

  An ink image drying apparatus according to a third aspect is the ink image drying apparatus according to the first or second aspect, wherein the ink image drying apparatus is disposed on the rear side in the paper conveyance direction of the belt heating mechanism and heats the paper on which the ink image is formed. A heating roller is further provided.

  Here, after the ink image is dried, it can be completely fixed on the paper.

  An ink image drying apparatus according to a fourth aspect is the ink image drying apparatus according to any one of the first to third aspects, further comprising a cooling device that cools the first paper transport belt.

  Here, it is possible to prevent the temperature of the first paper transport belt from becoming too high.

  An ink image forming apparatus according to a fifth aspect includes an image forming unit, a paper storage unit, a discharge unit, a paper transport unit, and an ink image drying device. The image forming unit has an inkjet head capable of ejecting ink on a sheet, and is a part capable of forming an ink image on a sheet based on image information. The paper storage unit is a part that stores paper for forming an ink image in the image forming unit. The discharge portion is a portion that discharges the paper on which the ink image is formed on the surface in the image forming portion. The paper transport unit is a part that transports paper from the paper storage unit to the discharge unit. The ink image drying apparatus is an apparatus according to any one of claims 1 to 4, which is disposed downstream of the image forming unit in the sheet conveyance direction.

  In this ink image forming apparatus, the paper in the paper storage unit is transported to the image forming unit by the paper transport unit, and ink is ejected from the inkjet head onto the paper based on the image information. The sheet on which the ink image is formed is conveyed to the fixing unit, and after the ink image is dried, it is discharged from the discharge unit.

  Here, since the ink image is discharged in a dried state, the sheets can be stacked, and even when the ink image is touched, the ink image is not easily broken.

  An ink image forming apparatus according to a sixth aspect is the ink image forming apparatus according to the fifth aspect, wherein the paper transport unit includes a second paper transport belt that transports the paper provided at a position facing the inkjet head. In addition. A second paper transport belt heating device for heating the second paper transport belt is further provided.

  Here, since the temperature of the paper is raised before being conveyed to the ink image drying device, the time required for drying the ink image can be further shortened.

  In the present invention, the ink image formed on the paper can be efficiently dried.

1. Overall Configuration FIG. 1 shows an inkjet printer 1 as an image forming apparatus in which an embodiment of the present invention is adopted. The ink jet printer 1 is connected to an external computer or the like, and is an apparatus capable of forming an image based on image information transmitted from the computer. The image forming unit 2, the ink image drying device 3, and paper storage A section 4, a paper transport section 5, and a discharge section 6 are provided. The ink used in the ink jet printer 1 is obtained by coating the surface of a pigment with a resin. Further, the ink image drying device 3 will be described in detail later.

  The image forming unit 2 is a part that forms an image based on image information, and includes an inkjet head 21. Four inkjet heads 21 are arranged side by side on the upper side of a second paper transport belt 52 of a paper transport unit 5 to be described later, and are portions that eject ink onto paper based on image information. Each inkjet head 21 stores ink of different colors, and has an ink discharge portion 211 that can discharge the stored ink. Furthermore, the inkjet head 21 is a member extending in one direction (a direction orthogonal to the paper surface of FIG. 1) and is a substantially rectangular parallelepiped member. The ink ejection part 211 is a plurality of holes formed side by side on an ink ejection surface arranged to face the paper.

  The paper storage unit 4 is a part capable of storing paper on which an image is formed, and is disposed below the ink jet printer 1. Further, the paper storage unit 4 has a paper supply roller 41 for supplying paper to the paper transport unit 5 above the front end on the paper transport direction side.

  The paper transport unit 5 is a part for transporting the paper in the paper storage unit 4 to the image forming unit 2 and transporting the paper on which the image is formed on the surface in the image forming unit 2 in the direction of the discharge unit 6. The paper transport unit 5 includes a plurality of rollers 51 for transporting paper, a second paper transport belt 52, and a first suction roller 53.

  The second paper transport belt 52 is for transporting paper to the lower side of the ink jet head 21, that is, the position facing the ink discharge portion 211 of the ink jet head 21, and includes a first circulation roller 521 and a second circulation roller. 522 and a second endless belt 523. The first circulation roller 521 as a driven roller is disposed on the upstream side in the paper conveyance direction of the paper conveyance unit 5 and extends in a direction orthogonal to the paper surface of FIG. The second circulation roller 522 is a roller arranged in parallel with the first circulation roller 521, and is connected to a drive mechanism including a motor (not shown). The second endless belt 523 is stretched between the first circulation roller 521 and the second circulation roller 522, and as shown in FIG. 3B, two layers of an elastic member layer 523a and a metal layer 523b. An annular belt member having a structure. Here, a metal effective for electromagnetic induction heating such as iron is used for the metal layer 523b of the second endless belt 523. When the paper is conveyed, the paper contacts the elastic member layer 523a. Here, FIG. 3B is an enlarged cross-sectional view of the second endless belt 523.

  The first suction roller 53 is for applying a bias voltage to the paper so that the paper is attracted to the second paper transport belt 52 to facilitate transport, and is arranged to face the first circulation roller 521. Has been.

  The discharge unit 6 is a part for discharging the paper on which the image is formed by the image forming unit 2, and is disposed on the upper part of the inkjet printer 1.

2. Configuration of Ink Image Drying Device The ink image drying device 3 is a device for drying an ink image formed on a sheet. As shown in FIG. 2, the first sheet conveying belt 31 and a belt heating mechanism 32 are used. A heating roller 33, a pressure roller 34, a cooling device 35, and an exhaust fan 36. The ink image drying device 3 is mainly disposed on the upper side of the paper storage unit 4.

  The first paper transport belt 31 is a part for transporting the paper transported by the second paper transport belt 52 to the discharge unit 6 side, and includes a third circulation roller 311, a fourth circulation roller 312, and an annular shape. A first endless belt 313. The third circulation roller 311 as a driven roller is disposed in the vicinity of the second paper transport belt 52. The fourth circulation roller 312 is arranged in parallel with the third circulation roller 311 and is connected to a drive system including a motor and the like. The first endless belt 313 is a member that is stretched between the third circulation roller 311 and the fourth circulation roller 312, and is composed of an elastic member layer 313 a and a metal layer 325 (second metal portion). It has a layered structure. The sheet is conveyed by the first sheet conveying belt 31 with the surface on which the ink image is formed on the upper side, that is, the sheet is conveyed without contacting the first sheet conveying belt 31.

  An air suction device (not shown) is provided inside the first paper transport belt 31, and a plurality of through holes having a hole diameter that does not hinder paper heating are provided in the first endless belt 313 of the first paper transport belt 31. The sheet is adsorbed to the surface of the first endless belt 313 by air suction.

  The belt heating mechanism 32 is a mechanism for directly heating the first paper transport belt 31 to increase its temperature, and includes a first excitation coil core 321, a first excitation coil 322, and a first excitation coil core support member. 323, a first coil guide plate 324, and a first temperature sensor 326 are provided. The belt heating mechanism 32 raises the temperature of the first endless belt 313 to about 120 degrees. The first coil guide plate 324 is a plate-like member provided in the vicinity of the first endless belt 313. The first exciting coil 322 is formed by alternately winding a long exciting coil wire along the coil guide plate 324 in the axial direction of the first endless belt 313, and the winding length of the first exciting coil 322 is the same as that of the first endless belt 313. The length is the same as the length orthogonal to the paper transport direction. The first excitation coil core 321 is a member formed of a ferromagnetic material such as ferrite, and is provided close to the first excitation coil 322. The first coil guide plate 324 is a plate-like member for guiding the first excitation coil 322. The first temperature sensor 326 is a device for measuring the temperature of the first endless belt 313, in the vicinity of the end of the first coil guide plate 324 on the fourth circulation roller 312 side, and in the third circulation of the cooling device 35. It is arranged near the roller 311 side and is a non-contact thermometer, for example, a radiation thermometer. A power source (not shown) is controlled according to the measurement result of the first temperature sensor 326, and it is determined whether or not to supply power to the first excitation coil 322. Here, FIG. 3A is an enlarged cross-sectional view of the first endless belt 313.

  With the above configuration, that is, since metal is provided on one layer of the first endless belt 313, when a current flows from the power source (not shown) to the first excitation coil 322, the first endless belt 313 is directly moved by electromagnetic induction heating. Will be heated.

  The heating roller 33 is disposed on the downstream side of the belt heating mechanism 32 in the sheet conveyance direction, that is, on the side where the fourth circulation roller 312 is disposed, and is a member for drying the ink image more reliably. The heating roller 33 is a member that contacts the first endless belt 313 and is a member that rises to about 160 degrees.

  The pressure roller 34 is a roller disposed so as to face the heating roller 33, and is disposed so as to contact the first endless belt 313.

  The cooling device 35 is disposed at a position facing the belt heating mechanism 32 with the first paper transport belt 31 interposed therebetween, and is a member that cools the first endless belt 313 with cooling water flowing through a cold water pipe (not shown).

  The exhaust fan 36 is disposed above the belt heating mechanism 32 and is a member for exhausting the vicinity of the belt heating mechanism 32.

  The second paper transport belt heating device 37 is a device for heating the temperature of the second paper transport belt 52 and is disposed at a position facing the inkjet head 21 with the second paper transport belt 52 interposed therebetween. The second paper transport belt heating device 37 includes a second excitation coil core 371, a second excitation coil core support member 372, a second excitation coil 373, a second excitation coil guide plate 374, and a second temperature sensor 375. It has. The second paper transport belt heating device 37 heats the second paper transport belt 52 to a temperature of 40 to 50 degrees.

  The second coil guide plate 374 is a plate-like member provided in the vicinity of the second endless belt 523. The second excitation coil 373 is formed by alternately winding one long excitation coil wire in the axial direction of the second endless belt 533 along the second coil guide plate 374, and the winding length is the second endless belt. The length 533 is orthogonal to the sheet conveyance direction. The second excitation coil core 371 is a member formed of a ferromagnetic material such as ferrite, and is provided close to the second excitation coil 373.

  The second excitation coil guide plate 374 is a plate-like member for guiding the second excitation coil 373.

  The second temperature sensor 375 is a radiation thermometer, and is disposed on the first circulation roller 521 side of the second excitation coil 373. A power source (not shown) is controlled by the second temperature sensor 375, and it is determined whether or not to supply power to the second excitation coil 373. That is, the temperature is prevented from excessively rising due to electromagnetic induction heating.

3. Operation The printing operation will be described.

  When image information is transmitted from an externally connected computer, the paper is transported from the paper storage unit 4 to the image forming unit 2 by the paper transport unit 5. Specifically, it is transported to the second paper transport belt 52. When the paper is transported onto the second paper transport belt 52, ink is ejected from the inkjet head 21 and an image is formed on the paper. Thereafter, the ink image is dried by the ink image drying device 3. The paper on which the ink image is formed is transported to the discharge unit 6 by the paper transport unit 5 and is discharged from the discharge unit 6. In this way, the printing operation is completed.

  Next, the ink image drying operation will be described in detail.

  Before the paper is transported onto the second paper transport belt 52, power is supplied to the second excitation coil 373 from a power source (not shown). When electric power is supplied to the second excitation coil 373, a magnetic field is generated around the second excitation coil 373, and the temperature of the metal layer 523b of the second endless belt 373 is increased by electromagnetic induction heating, so that the second endless coil 373 is heated. The temperature of the entire belt 523 is raised. At this time, the temperature of the second endless belt 523 is heated to about 40 to 50 degrees. In this state, when the paper is transported onto the second paper transport belt 52, the paper is warmed by the temperature of the second endless belt 523 and the paper is transported to the first paper transport belt 31 side. At that time, the first paper transport belt 31 is heated by the belt heating mechanism 32. Specifically, power is supplied from a power source (not shown) to the first excitation coil 322, and the second metal portion 325 is heated by electromagnetic induction heating, that is, the first paper transport belt 31 is heated to about 120 degrees. Has been. Then, the sheet is conveyed from the second sheet conveying belt 52 side to the first sheet conveying belt 31 side. The sheet is heated by the first sheet conveying belt 31 to dry the ink image. Thereafter, the sheet is conveyed between the heating roller 33 and the pressure roller 34, and the ink image is completely dried by the heating roller 33. When the heating roll 33 is heated using an electromagnetic induction heating method, for example, the printing rate is 20% or more, and the heating roller 33 is used only when drying a sheet on which an image including many solid parts is printed. You may make it heat. Since the temperature of the heating roller 33 is about 160 degrees, the temperature of the first paper conveying belt 31 in contact with the heating roller 33 is 120 degrees or higher, but the cooling device 35 cools the temperature to about 120 degrees. The In order to cool the temperature of the first paper transport belt 31 to such an extent that the paper can be removed from the first paper transport belt 31 without being burned when a paper jam occurs on the first paper transport belt 31. The cooling device 35 is also used. In order to prevent burns, if the temperature of the first paper transport belt 31 is cooled to a specified temperature (for example, 70 degrees) by the cooling device 35, the first paper transport belt 31 can be pulled out from the main body of the inkjet printer 1 so that paper jam can be handled. It is configured.

  Here, since the temperature of the first paper transport belt 31 is raised and the paper is in contact with the first paper transport belt 31, heat is efficiently transferred from the first paper transport belt 31 to the paper. For this reason, the ink image on the paper is easily dried. Further, since the first paper transport belt 31 does not directly contact the ink image, it is possible to make the ink image difficult to collapse. Further, since the temperature of the second paper transport belt 52 is raised and the temperature of the paper is raised by the second paper transport belt 52, the time required for drying the ink image can be further shortened. it can.

3. Other Embodiments (a) In the above embodiment, the temperatures of the first and second endless belts are increased by electromagnetic induction heating. However, the present invention is not limited to this, and other methods such as a coil heater are used to endlessly. The belt may be heated directly.

  (B) In the above embodiment, the heating roller 33 and the pressure roller 34 are disposed on the downstream side of the first excitation coil 322 in the sheet conveying direction. However, the present invention is not limited to this, and the heating and pressure roller 33, 34 may not be arranged.

  (C) In the above embodiment, the metal layer is provided on the paper conveying belt. However, the present invention is not limited to this, and a metal may be attached to the belt.

1 is an overall schematic diagram of an inkjet printer. FIG. 3 is a diagram illustrating an ink image drying device and an image forming unit. The enlarged view of the endless belt of a 1st paper conveyance belt and a 2nd paper conveyance belt.

Explanation of symbols

1 Inkjet printer (ink image forming device)
2 Image forming unit 3 Ink image drying device 4 Paper storage unit 5 Paper transport unit 6 Discharge unit 21 Inkjet head 31 First paper transport belt 32 Belt heating mechanism 33 Heating roller 35 Cooling device 37 Second paper transport belt heating device 52 Second Paper conveying belt 322 First excitation coil 325 Second metal part

Claims (6)

An ink image drying apparatus that dries an ink image disposed in an image forming apparatus that forms an image on paper using ink,
A first paper transport belt for transporting paper on which an ink image is formed;
A belt heating mechanism for directly heating the first paper transport belt to increase the temperature of the first paper transport belt;
Ink image drying apparatus comprising: The first paper transport belt has a metal portion;
The belt heating mechanism has an excitation coil disposed in the vicinity of the first paper transport belt,
The ink image drying apparatus according to claim 1. A heating roller that is disposed on the rear side of the belt heating mechanism in the paper conveyance direction and that heats the paper on which the ink image is formed;
The ink image drying apparatus according to claim 1.   The ink image drying apparatus according to claim 1, further comprising a cooling device that cools the first paper transport belt. An image forming unit having an inkjet head capable of ejecting ink on paper, and capable of forming an ink image on paper based on image information;
A paper storage portion for storing paper for forming an ink image in the image forming portion;
A discharge unit for discharging the paper on which the ink image is formed on the surface in the image forming unit;
A paper transport section for transporting paper from the paper storage section to the discharge section;
The ink image drying device according to any one of claims 1 to 4, wherein the ink image drying device is disposed downstream of the image forming unit in a sheet conveyance direction.
An ink image forming apparatus comprising: The paper transport unit further includes a second paper transport belt for transporting paper provided at a position facing the inkjet head,
A second paper transport belt heating device for heating the second paper transport belt;
The ink image forming apparatus according to claim 5.

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