JP6517160B2 - inkjet printer - Google Patents

Description

  The present invention relates to an ink jet printer.

  2. Description of the Related Art Inkjet printers for recording an image by discharging ink onto a recording medium are widely used. In recent years, large-sized ink jet printers for recording on wide recording media exceeding 1 m are widely used, as well as being used for document preparation as home printers and office printers. In order to use the recorded matter outdoors, in order to prevent the color from being faded or dropped due to the influence of wind or sunlight, there is one using a pigment ink in which a pigment is dispersed in a solvent.

  For example, in such an inkjet printer, a recording medium such as a plastic film wound in a roll is conveyed to a flat platen to perform recording. Recording is performed by discharging ink from the recording head to a recording medium supported flat on the platen. In an ink jet printer using a pigment ink, if it takes a long time to dry ink droplets attached to a recording medium, adjacent ink droplets may mix and blur, or a blurred image may occur. Further, even if the temperature distribution on the platen surface is different, a difference occurs in the fixing of the ink on the recording medium, which causes the deterioration of the image quality.

  For example, in the ink jet recording apparatus of JP-A-2014-237308, a groove is provided on the back surface of a flat plate supporting a recording medium, and a heater wire is inserted and fixed there. Furthermore, the easily folded back portion is supported by a plate so that the heater wire does not fall out of the groove and hang down. By doing this, heat from the heater wire can be efficiently transmitted to the platen, and the distribution of the surface temperature of the platen can be made uniform.

JP, 2014-237308, A

  The platen is provided with numerous suction holes. Further, the back side of the platen is a suction chamber for decompressing and sucking air from the suction hole. In the platen, the suction hole is closed at the portion where the recording medium is placed, but at the portion where the recording medium is not placed, air is sucked from the suction hole to generate an air flow. When the recording medium is in the form of a mesh or a porous medium, air passes through the recording medium and the suction holes to generate an air flow.

  By drawing air from the suction holes, an air flow is generated in the suction chamber, and the back side of the platen is cooled. A groove is provided on the back of the platen, and a heater wire is disposed there. The back of the platen is not uniform, and there is a difference in cooling due to the air flow, which has a problem of affecting the temperature distribution on the surface.

  Therefore, an object of the present invention is to provide an ink jet printer capable of efficiently transmitting the heat of the heater to the platen, suppressing a partial temperature difference of the platen, and capable of good recording. In the inkjet printer according to the present invention, a plurality of suctions are provided at positions facing a recording head including a nozzle for discharging ink onto a recording medium, a carriage on which the recording head is mounted, and the nozzle of the recording head. A platen provided with a hole and supporting the recording medium by suctioning air from the suction hole, a heater disposed in a groove provided on the back surface of the platen, and heating the platen, and conveying the recording medium A conveying means, a frame for fixing the platen, and a plurality of support plates fixed to the platen to adjust the distortion of the platen by changing the fixing position with the frame; The above recording is performed while reciprocating the carriage on the heated recording medium in the direction intersecting the conveyance direction of the recording medium. In an ink jet printer which ejects the ink from a head to record an image, the ink jet printer is disposed on the back side of the platen, covers the groove, has a through hole at a position corresponding to the suction hole, and has thermal conductivity from the platen A low cover and a fixing member for fixing the cover to the platen.

  According to the present invention, heat is efficiently conducted from the heater to the platen, and good recording can be performed by suppressing a partial temperature difference of the platen.

FIG. 1 is a view for explaining the structure of the back side of the platen. FIG. 2 is an enlarged view of the back surface of the platen. FIG. 3 is a cross-sectional view for explaining the support structure of the platen of the ink jet printer. FIG. 4 is a schematic view showing the entire ink jet printer.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, the structure of the platen will be described. FIG. 1 is a view for explaining the structure of the back side of the platen. FIG. 2 is an enlarged view of the back surface of the platen. These figures are viewed from the back side of the platen 1.

  A groove is provided on the back surface side of the platen 1, and the heater wire 6 is fitted and fixed in the groove. Further, a plurality of divided plates 2 are fixed to the platen 1 so as to cover the heater wires 6 embedded in the grooves. The plate 2 is fixed to the platen 1 by a plate support plate 3. That is, the plate support plate 3 is a fixing member for fixing the plate 2 to the platen 1. Further, the platen 1 is fixed to the frame of the ink jet printer through the platen support plate 4. The plate 2 is provided with holes 7 corresponding to the positions of suction holes 9 provided in the platen 1. The plate 2 is a cover that covers the heater wire 6.

  The temperature sensor 5 measures the temperature of the end portion and the central portion of the platen 1. The temperature sensor 5 is fixed to the platen 1. The plate 2 is opened at a portion corresponding to the temperature sensor 5. Also, the temperature sensor 5 can be fixed to the plate 2. In this way, even if the platen 1 is fixed to the housing, the plate 2 can be attached and detached, so that maintenance of the temperature sensor 5 can be facilitated. When the temperature sensor 5 is fixed to the plate 2, with such a configuration, the temperature sensor 5 can be disposed at an arbitrary position on the platen 1 simply by replacing the plate 2. The temperature sensors 5 can also be arranged on all the plates 2. Also, in accordance with the width of the recording medium used frequently, for example, when using one having a half width of the platen 1 often, the temperature is finely set by arranging the three temperature sensors 5 in the half width part. Adjustments can also be made.

  The plate position 8 indicated by a dotted line indicates where the plate 2 is to be fixed. The heater wire 6 is disposed along the longitudinal direction of the platen 1. A plurality of grooves are arranged in parallel. The suction holes 9 of the platen 1 are holes penetrating the front and back of the platen 1, and a plurality of suction holes 9 are arranged on the entire surface of the platen 1. In the plate 2, holes 7 penetrating the front and back of the plate 2 are disposed at positions corresponding to the suction holes 9.

  The plate 2 is formed in a flat plate along the shape of the back surface of the platen 1. The plate 2 covers the heater wire 6 fitted in a groove provided in the platen 1 and is fixed to the platen 1. The plate support plate 3 is a plate having a length approximately equal to the width of the platen 1, and the longitudinal direction is disposed along the conveyance direction of the recording medium. The plate support plate 3 is provided with three screw holes and fixed to the platen 1 by screws 11. The platen support plate 4 is fixed to the platen 1 by a screw 10. A disc spring is inserted between the platen support plate 4 and the screw 10. It is possible to prevent loosening of screws such as vibration and impact, and obtain stable tightening axial force by heavy load. Thus, when deformation of the platen 1 occurs due to heat, the deformation can be allowed.

  The heater wire 6 is fitted in a groove provided in the platen 1. The plate 2 covers the top. For example, when air flow is generated on the back side of the platen 1 by suction of air, the heater wire 6 can be prevented from hitting the wind. Thereby, the cooling by airflow can be suppressed. Further, the platen 1 is made of aluminum or aluminum alloy having a good thermal conductivity, and the plate 2 uses a metal plate having a thermal conductivity lower than that. For example, it is preferable to use an iron alloy, such as SUS, which is less susceptible to the influence of the solvent of the ink. Further, this can prevent the heater wire from being detached, and can prevent the temperature difference from becoming uneven due to the detachment.

  The heater wire 6 fitted in the groove of the platen 1 is pressed by the plate 2 so that the heater wire 6 is in contact with the bottom of the groove in the back direction. That is, the outer skin of the heater wire 6 is crushed and fitted into the groove. The platen support plate 4 also presses the heater wire 6 in the same manner. By bringing the heater wire 6 and the platen 1 into close contact, it is possible to reduce the loss of heat conduction. Moreover, the hole 7 is not provided in the part facing the heater wire 6 of the plate 2. It is because it can not be pushed in suitably. The plate 2 is fixed to the platen 1 by the plate support plate 3 only at the central portion. The plate 2 is desired to have high rigidity in order to push the heater wire 6 suitably. Preferably, it is made of metal such as SUS, and it is preferable that there is a rib in the direction along the heater wire 6.

  Alternatively, a spacer may be inserted between the heater wire 6 and the plate 2 and pushed by the plate 2 to the back of the groove. The spacer is preferably a heat insulating material made of resin. If the heater wire 6 fitted in the groove can be sufficiently in close contact with the platen 1, an air layer can be provided without pressing the heater wire 6 with the plate 2. It is preferable to provide a gap equal to or greater than the radius of the heater wire 6, more preferably equal to or greater than the diameter. If there is a certain distance, it can be effectively insulated. This air layer serves as a heat insulating layer, and the heat of the heater wire 6 can be prevented from being directly transferred to the plate 2, and can be efficiently transferred to the platen 1.

  As a recording medium for an outdoor display, a plastic film such as vinyl chloride or PET having good weather resistance, which is not easily affected by ultraviolet light and heat, is used. Such a recording medium is easily charged. Therefore, it is preferable that the plate 2 be also conductive such as metal so as not to be affected by the recording medium in which the plate 2 is charged from the gaps such as the suction holes 9 of the platen 1.

  By dividing the plate 2 into a plurality of pieces and fixing each plate 2 to the platen 1 by one plate support plate 3, it is possible to prevent distortion or the like due to the difference in thermal expansion coefficient between the plate 2 and the platen 1. In particular, since the platen 1 is easily stretched in the longitudinal direction, the platen 1 and the plate 2 are not fixed in that direction. The plate support plate 3 can also be used to correct bending of the platen 1 in the lateral direction. The plate support plate 3 has a length extending in the lateral direction of the plate 2, that is, the transport direction of the recording medium. This is wider than the recording area of the recording head.

  Since the plate support plate 3 is fixed via the plate 2, heat loss can be suppressed more than direct fixing. Further, since the back surface side of the platen 1 can be substantially covered by the plate 2, the influence of the cooling of the heater wire 6 and the air flow of the groove and the like can be suppressed and the temperature on the back surface can be made uniform. Thereby, the influence on the temperature distribution on the surface side due to the difference in the temperature distribution on the back surface side can be suppressed.

  In addition, it is preferable that the holes 7 of the plate 2 are disposed corresponding to all the suction holes 9, but if it is desired to reduce the number of the suction holes 9, etc. The hole 9 can also be closed. By changing the plate 2, it is possible to easily change.

  In addition, the plate support plate 3 is a wall standing vertically to the plate 2. In the vicinity of this wall, it becomes difficult for the wind to pass. For example, when air is introduced from the suction holes 9, the plate support plate 3 is provided between the platen support plates 4 so that the flow of air on the plate 2 side of the suction chamber can be restricted. The influence of air flow can be partially suppressed.

  FIG. 3 is a cross-sectional view for explaining the support structure of the platen of the ink jet printer. The ink jet printer 20 has a recording head 28 mounted on a carriage 27 and discharges ink from the recording head 28 to make recording while reciprocating the carriage 27. The recording medium is fed from the rear paper guide 29 side, is sandwiched between the conveyance roller 33 and the pressure roller unit 35, and is conveyed by the rotation of the conveyance roller 33. The recording medium is conveyed while being adsorbed by the plurality of suction holes 9 on the platen 1. The recording medium after recording is supported by the front paper guide 30 and discharged.

  A rear heater 31 is provided on the back of the rear paper guide 29. The rear paper guide 29 is heated by the rear heater 31. By preheating before the recording medium is conveyed to the platen 1, the temperature drop of the platen 1 can be prevented. The platen 1 is heated by the heater wire 6. By uniformly heating the recording medium to an appropriate temperature, variations in image quality can be suppressed. A front heater 32 is provided on the back of the front paper guide 30. The front paper guide 30 is heated by the front heater 32. By heating the recording medium after recording, the solvent of the ink is evaporated to dry and accelerate fixing.

  The platen 1 is disposed along the longitudinal direction of the ink jet printer 20, and the rail 26 is disposed parallel thereto. The carriage 27 reciprocates along the rails 26. The exterior cover 34 covers these.

  The ink jet printer 20 is provided with a standing plate 21 which is one of the frame configurations for fixing the platen 1. The platen 1 is fixed to the standing plate at a plurality of positions. For example, when only the both ends are supported, a problem such as distortion of the center occurs. Fix the platen 1 so as not to distort. Further, the back side of the platen 1 is divided into a plurality of rooms by the plurality of standing plates 21. Each room or suction chamber is provided with an exhaust fan 25 which sucks air from the suction holes 9 of the platen 1. When the recording medium is present on the platen 1, the recording medium can be adsorbed. The air sucked by the exhaust fan 25 is exhausted from the lower part of the housing to the outside.

  The standing plate 21 and the platen support plate 4 are fixed by screws 22, 23 and 24. The fixing portion of the platen support plate 4 has an elongated hole, and the fixing position by the screw can be varied. By the part which is this long hole, the inclination of the platen 1 and the height of the platen 1 can be matched and fixed so that the whole becomes a flat plate. The length of the platen support plate 4 in the conveyance direction of the recording medium is wider than the width of the recording head in the conveyance direction of the recording head 28. In order to fix the platen 1 and correct it into a flat plate shape, it is necessary to have at least a width equal to or more than the recording width of the recording head 28. Also, the plate support plate 3 can be considered similarly to the platen support plate 4, and preferably the same one is used.

  The entire inkjet printer will be described with reference to FIG. The ink jet printer 20 has shown the internal structure which removed the exterior case. A carriage 27 mounted with a recording head for discharging and recording ink on a recording medium reciprocates along the platen 1 and performs recording on the recording medium supported by the platen 1. The carriage 27 is fixed to a belt 36 and moves by driving the belt 36. The platen 1 is disposed along the longitudinal direction of the ink jet printer 20. The recording medium is sandwiched between the conveyance roller 33 and the pressure roller unit 35, and is conveyed by the rotation of the conveyance roller 33. The conveying direction of the recording medium and the moving direction of the carriage 27 intersect. For example, it crosses at 90 degrees. A plurality of pressing roller units 35 are arranged along the longitudinal direction of the platen 1. The recording medium after recording is discharged along the front paper guide 30.

  The present invention can be used for a recording apparatus provided with an ink jet recording head.

Reference Signs List 1 platen 2 plate 3 plate support plate 4 platen support plate 5 temperature sensor 6 heater wire 7 hole 9 suction hole 20 ink jet printer 21 vertical plate 25 exhaust fan 26 rail 27 carriage 28 recording head 29 rear paper guide 30 front paper guide 33 transport Roller 34 Exterior cover 35 Pressure roller unit

Claims (5)

A recording head comprising a nozzle for ejecting ink onto a recording medium;
A carriage on which the recording head is mounted;
A platen provided with a plurality of suction holes at a position opposite to the surface on which the nozzles of the recording head are arranged, and suctioning air from the suction holes to support the recording medium;
A heater disposed in a groove provided on the back surface of the platen and heating the platen;
Transport means for transporting the recording medium;
A frame for fixing the platen;
A plurality of support plates that are fixed to the platen and that regulate the distortion of the platen by changing a fixed position with the frame;
An ink jet recording apparatus which ejects the ink from the recording head while reciprocating the carriage in a direction crossing the conveyance direction of the recording medium, onto the recording medium heated by the platen, thereby recording an image At the printer
A cover disposed on the back side of the platen, covering the groove, and having a through hole at a position corresponding to the suction hole, the cover having a thermal conductivity lower than that of the platen;
A fixing member for fixing the cover to the platen;
An inkjet printer characterized by having: The cover is divided into a plurality of parts,
The divided respective covers are disposed between the support plates for fixing the platen, and the respective covers are fixed by the fixing members corresponding to the respective covers,
The inkjet apparatus according to claim 1, wherein the fixing member includes a plate disposed along the lateral direction of the platen, and screws fixed to the platen at a plurality of locations along the lateral direction. printer. The back side of the platen is divided into a plurality of spaces, and each space has a fan, which sucks in air from the suction hole and exhausts it to the outside.
The said fixing member is standingly provided from the back surface side of the said platen, and restrict | limits the air flow which flows in the longitudinal direction of the said platen of the back surface side of the said platen, It is characterized by the above-mentioned. Inkjet printer.   The ink jet printer according to any one of claims 1 to 3, wherein the heater is pressed in the back direction of the groove by the cover, and the heater and the bottom surface of the groove are in contact with each other. .   The ink jet printer according to any one of claims 1 to 3, wherein a gap is provided between the heater and the cover.

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