WO2016084415A1

WO2016084415A1 - Inkjet printing apparatus

Info

Publication number: WO2016084415A1
Application number: PCT/JP2015/067820
Authority: WO
Inventors: 直樹松屋
Original assignee: 株式会社データ・インフォテック
Priority date: 2014-11-26
Filing date: 2015-06-22
Publication date: 2016-06-02
Also published as: JP2016097671A; JP6373178B2

Abstract

Provided is an inkjet printing apparatus that limits nonuniformities of platen surface temperature and is capable of printing favorably. The inkjet printing apparatus has a flat platen in which suction holes for sucking print medium are formed, the inkjet printing apparatus being provided with a platen cover so as to cover the platen. The platen cover is fixed on the platen surface closely adhering thereto and limits nonuniformities of surface temperature. By making the platen surface temperature uniform, it is possible to eliminate differences in fixing rate according to location and print high quality images.

Description

Inkjet recording device

The present invention relates to an ink jet recording apparatus.

Conventionally, an inkjet recording apparatus that includes an inkjet recording head and ejects ink droplets from nozzles is known. Some inkjet recording apparatuses have a recording head mounted on a carriage and eject ink droplets while moving the carriage. In this ink jet recording apparatus, a recording medium is held on a flat platen, a carriage is moved along the platen, and ink droplets are ejected from nozzles onto the recording medium for recording. In such an ink jet recording apparatus, a suction hole is provided in the platen, and the recording medium is sucked and fixed to the platen through the suction hole. Therefore, the recording surface of the recording medium can be kept flat along the platen.

Also, the recording medium is conveyed by sliding on the platen by the conveying device while being sucked by the suction holes. In such a recording operation of the ink jet recording apparatus, the recording medium is transported by a predetermined movement distance and stopped, and ink is ejected from the nozzles onto the recording medium while scanning the carriage in the width direction of the recording medium. Record. When one scan is completed, the recording medium is again conveyed by a predetermined distance and stopped, and ink is ejected in the same manner as described above to perform recording. By repeating such an operation, a desired image is formed on the recording medium.

The recording medium needs to slide on the platen. However, the recording medium may not be smoothly moved on the platen due to the frictional resistance between the platen and the recording medium or due to the suction force to the recording medium by the suction holes, and may be conveyed in a distorted state such as a wavy state. is there. For example, as disclosed in Patent Document 1, an ink jet recording apparatus is disclosed in which a countermeasure such as providing a fluororesin layer is provided on the surface of the platen to reduce the frictional resistance between the platen and the recording medium. . Also, in the cited document 1, an ink jet recording apparatus in which a contact area between the platen and the recording medium is reduced by providing a groove in the platen in order to reduce the frictional resistance between the platen and the recording medium is also disclosed.

JP 2004-122554 A

However, the inkjet recording apparatus uses PVC tarpaulin or cloth as a recording medium, or resin sheets made of various resins such as polyester and PVC. Various recording media have different frictional resistances with respect to the platen. Further, the recording medium is easily bent depending on the thickness and material. Also, in the case of a platen with a heater that promotes drying of ink, if there is a groove in the platen, the temperature of the recording medium in the part corresponding to the groove is higher than the temperature of the part of the recording medium in direct contact with the platen. It will be lower. Due to the temperature difference, a difference in the drying speed of the ink may occur, and a groove pattern may appear in the formed image. Further, in the conventional platen, depending on the type of the recording medium, it may be undulated and conveyed due to frictional resistance, and appropriate recording may not be possible. Further, depending on the type of the recording medium, it may bend along the groove of the platen, and ink may not be ejected to a desired position on the recording medium, so that proper recording may not be performed.

The present invention has been made in order to solve the above-described problems. Even when various recording media are used, the recording medium can be appropriately conveyed, appropriately held on the platen, and appropriately recorded on the recording medium. An object of the present invention is to provide an ink jet recording apparatus, a recording method, and a platen cover.

In order to solve the above-described problems, an inkjet recording apparatus of the present invention includes a conveyance device that conveys a recording medium, a recording head that includes a plurality of nozzles for ejecting ink, and a plurality of surfaces on a surface facing the recording medium A flat platen having a suction hole, suction means communicating with the suction hole for sucking the recording medium, and a flat platen cover provided on the platen and having a plurality of communication holes communicating with the front and back. The suction hole sucks the recording medium through the communication hole and transports the recording medium while adsorbing the recording medium to the platen cover, and fixing means for fixing the platen cover to the platen The fixing means is a magnet placed in a recess provided in the platen, and the recording head side of the magnet is configured to be flat. The bottom of the recess is provided with a screw hole communicating with the back surface of the platen, a screw is disposed in the screw hole, a tip of the screw is in contact with the magnet, and the screw is rotated to rotate the magnet. The platen cover is prevented from bending at the fixing means by matching the height of the flattened surface of the magnet with the height of the platen surface, and the platen cover is moved by the magnet. It is characterized by adsorbing.

According to the present invention, even if the type of the recording medium is different, the recording medium can be smoothly conveyed on the platen, the recording medium is appropriately held on the platen, and unevenness of the surface temperature of the platen is suppressed, Recording suitable for the recording medium is possible.

FIG. 1 is a perspective view showing the configuration of the ink jet recording apparatus. FIG. 2 is a diagram illustrating the configuration of the platen. FIG. 3 is a diagram illustrating an example of fixing the platen cover. FIG. 4A is a diagram for explaining a first state of the platen cover fixing means. FIG. 4B is a diagram illustrating a second state of the platen cover fixing means. FIG. 5 is a diagram illustrating a preferred arrangement of the platen cover. FIG. 6 is a diagram illustrating an example of the surface of the platen cover.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.
FIG. 1 is a perspective view showing the configuration of the ink jet recording apparatus. As shown in FIG. 1, the inkjet recording apparatus 1 conveys a film-like or plate-like recording medium 17 indicated by a broken line, and images, characters, etc. according to image data are formed on the surface of the recording medium 17 by an inkjet method. Record. Examples of the recording medium 17 include paper, PVC tarpaulin, cloth, a film made of a synthetic resin such as polyester or PVC, and a plate. The inkjet recording apparatus 1 is roughly configured to include a base 13, a transport device 10 that transports a recording medium 17 provided on the base 13, and a print recording apparatus 2 that records and records on the recording medium 17. ing.

The transport apparatus 10 includes at least a transport roller 9 that rotates by receiving a rotational drive of a motor, and a pressure roller unit 8 that pressurizes the transport roller 9. A recording medium 17 is sandwiched between the transport roller 9 and the pressure roller unit 8 and is transported by the rotation of these rollers. A platen 12 that supports the recording medium 17 is provided at a location adjacent to the transport device 10. A platen cover 20 is placed and fixed on the platen 12. The platen 12 and the platen cover 20 serve as locations for printing and recording on the recording medium 17 by the printing recording apparatus 2. A heater for heating the platen 12 is provided under the platen 12. With this heater, the platen 12 and the platen cover 20 are heated, and the recording medium 17 is further heated to promote fixing of the ink ejected to the recording medium 17. The platen 12 is provided on the base 13 so as to extend in a direction orthogonal to the direction in which the recording medium 17 is conveyed. Further, 19 pairs of the transport roller 9 and the pressure roller unit 8 are arranged on the same axis line at adjacent portions of the platen 12 at a predetermined interval, for example, 87.65 mm.

The printing recording apparatus 2 roughly includes an inkjet head 3 that performs recording by ejecting ink droplets onto a recording medium 17, a carriage 4 that houses the inkjet head 3, a transport belt 11 that is connected to the carriage 4, A driving pulley 5 and a driven pulley 6 that are wound around the conveying belt 11, a driving motor 18 that rotationally drives the driving pulley 5, and a guide rail that guides scanning of the carriage 4 in a direction orthogonal to the conveying direction of the recording medium 17. 7. Further, like the platen 12, the transport belt 11 and the guide rail 7 are provided on the base 13 so as to extend in a direction orthogonal to the direction in which the recording medium 17 is transported. The carriage 4 slides in a direction orthogonal to the direction in which the recording medium 17 is conveyed, that is, in the direction of the bidirectional arrow AB in the drawing.

The ink supplied to the inkjet head 3 is stored in the ink cartridge 14. The ink cartridge 14 is a replaceable cartridge type ink container. Replace when ink runs out.

The pressure roller unit 8 is disposed so as to form a pair for each conveyance roller 9 that conveys the recording medium 17. The roller of the pressure roller unit 8 is driven to rotate while pressing the recording medium 17 toward the conveying roller 9. That is, the lower surface of the recording medium 17 is in contact with the conveying roller 9, and the upper surface is in contact with the roller of the pressure roller unit 8. The pressure roller unit 8 is fixedly attached to the base 13 of the printer 1.

The inkjet recording apparatus 1 is provided with a suction means for adsorbing the recording medium 17 to the platen cover 20 or the platen 12. The suction means is roughly provided in the platen 12, a suction hole that penetrates the platen 12, a suction fan 16 that sucks air, a suction chamber 15 that connects the suction hole and the suction fan 16, and a platen cover 20. A communication hole 19 is provided. The platen 12 has a plurality of suction holes communicating with the suction chamber 15. The inside of the suction chamber 15 is partitioned into four rooms, and a suction fan 16 is provided for each room. The communication hole 19 of the platen cover 20 passes through the platen cover 20. Details will be described later.

FIG. 2 is a diagram illustrating the configuration of the platen. The platen cover 20 is provided with a plurality of through holes 19 on substantially one surface. The platen 12 is provided with a plurality of suction holes 31. The area of the opening of one suction hole 31 is larger than the area of the opening of one through hole 19. However, regarding the portion where the suction holes 31 of the platen 12 are arranged, the opening ratio of the suction holes 31 per unit area is lower than the opening ratio of the through holes 19 per unit area of the platen cover 20. That is, the through-hole 19 has a large number of small openings, so that the entire opening is widened. On the other hand, the suction holes 19 are arranged with few large holes. This is because the thickness of the platen cover 20 can be made thinner than that of the platen 12, so that small holes can be formed with a fine pitch. As a result, the recording medium 17 can be adsorbed in a wide range and flattened. The smaller the opening is, the more the recording medium 17 can be kept flat without being recessed there even if it is sucked there.

Further, magnets 21 are arranged at predetermined intervals in the longitudinal direction of the platen 12. By making the platen cover 20 from an iron alloy such as stainless steel, the magnet 21 can be fixed to the platen 12 as a fixing means. The fixing means may be a screw or a structure that hangs on a groove, but a magnet that can be easily attached and detached is preferable.

The platen 12 needs to heat the recording medium 17 uniformly, and is preferably made of aluminum or aluminum alloy having high thermal conductivity. If the platen 12 is made of aluminum and the platen cover 20 is made of stainless steel, the thermal expansion coefficients of the two are different. If the platen 12 and the platen cover 20 are fixed together with an adhesive or a screw, the amount of deformation due to a change in temperature differs and the platen cover 20 is bent. On the other hand, since the surface can be slid by fixing with the magnet 21, generation | occurrence | production of bending can be prevented. Therefore, it can ensure that it is flat.

FIG. 3 is a diagram for explaining an example of fixing the platen cover. The magnet 21 is inserted into the fixing hole 24 penetrating the platen 12 from the front surface side of the platen 12, and the screw 23 is rotated into the fixing hole 24 from the back surface side to enter. The height from the platen surface is adjusted by the amount of penetration, and the surface of the magnet 21 is set to the same height as the surface of the platen 12. By making this the same height, the air layer in that portion is eliminated, so that the heat of the heater that heats the platen 12 can be transmitted without loss, and unevenness in the surface temperature can be suppressed. Also, variations in the attractive force due to the magnet 21 can be prevented. For example, when there is a space, the attractive force of the magnet 21 is reduced. With the magnet 21 disposed, the platen cover 20 is placed on the platen 12 and fixed with the force of the magnet 21. The platen cover 20 can be a resin including a magnet and a ferromagnetic material in consideration of fixing with the magnet 21, but a metal is preferable in consideration of heat conduction. In the case of metal, ferritic stainless steel such as SUS430 or an iron plate is preferable. Stainless steel is preferable in view of strength and handleability. Further, a sheet-like magnet may be disposed on the back side of the platen cover 20. Further, the platen cover 20 itself may be a sheet-like magnet.

Since the magnet 21 and the screw 23 are fixed by magnetic force, it is desirable that the tip of the screw 23 and the contact surface of the magnet 21 are flat. Alternatively, the magnet 21 and the screw 23 may be fixed with an adhesive. Alternatively, the magnet 21 and the screw 23 may be integrated, provided with a thread, and rotated into the fixing hole. In the above description, the magnet 21 and the screw 23 are fixed by magnetic force. However, the magnet 21 may be fixed by providing a screw groove.

The platen cover 20 is provided in the platen 12 at a position where the platen cover 20 is disposed, and the platen cover 20 is fitted into the platen 12, so that the platen cover 20 can be prevented from moving when the recording medium 17 is conveyed. This is preferably fixed only on one side of the platen 12 on the downstream side or the upstream side in the conveyance direction of the recording medium 17. This prevents unexpected deformation due to the difference in thermal expansion coefficient. For example, it is possible to prevent the platen cover 20 from moving in the conveyance direction of the recording medium 17 by bending one side in the longitudinal direction of the platen cover 20 and providing a recess at the edge along the longitudinal direction of the platen 12.

Also, the platen cover 20 may be fixed with screws or wedges at the corners so that the platen cover 20 does not move. It is preferable that the portion provided with the movement preventing means is a portion other than the recording range where ink is not ejected by the recording head 3 so that the image quality and the conveyance are not affected.

FIG. 4A is a diagram illustrating a first state of the platen cover fixing means. FIG. 4B is a diagram illustrating a second state of the platen cover fixing means. The platen 12 is provided with a heater groove 27 into which a heater wire 28 is fitted. The heater wire 28 is disposed on the back side of the platen 12.

The fixing hole 24 is provided with a screw groove. The screw 23 is provided with a screw thread. The screw 23 is preferably a set screw. The screw 23 advances and retreats in the fixing hole 24 by rotating. The tip of the screw 23 comes into contact with the magnet 21. When the screw 23 is in the first state, a gap is generated between the front end surface 2 of the screw 23 and the back surface 26 of the platen cover 20. When the screw 23 is rotated and advanced, the gap is eliminated in a second state. The screw 23 is advanced and retracted so that the tip surface 25 of the screw 23 and the surface of the platen 12 are at the same height. The screw 23 and the magnet 21 are fixed by magnetic force. Further, the magnet 21 and the platen cover 20 are also fixed by the magnet. The screw 23 and the magnet 21 may be fixed with an adhesive. The portion of the fixing hole 24 where the magnet 21 is inserted has a step, and the magnet 21 stops in the middle of the hole and does not fall.

Since both the platen 12 and the magnet 21 have variations in dimensions, the magnet 21 is thus retracted into the fixing hole 24 in the design so that the position can be adjusted with the screw 23. By using the screw 23 as a set screw, the platen 12 may be moved forward and backward.

Further, it is preferable that the material of the screw 23 is determined so that the magnet 21 is more firmly attracted to the screw 23 so that the magnet 21 does not pop out even if the platen cover 20 is removed. Further, since the platen cover 20 has a hole, the attractive force of the magnet 21 is somewhat weakened.

FIG. 5 is a diagram illustrating a preferred arrangement of the platen cover. A large number of communication holes 19 are arranged in the platen cover 20. If there is a gap 30 between the platen cover 20 and the platen 12, air can be sucked in a wide range of the platen cover 20. If there is no gap between the platen cover 20 and the platen 12, air can be sucked only directly above the opening of the suction hole 31 of the platen 12. The communication hole 19 is provided over almost the entire surface of the platen cover 20. Since it is a pore, the recording medium 17 is difficult to sink there by suction, and can be kept flat. Further, the frictional resistance can be lowered by reducing the contact area with the recording medium 17.

FIG. 6 is a diagram illustrating an example of the surface of the platen cover. This is means for providing a gap between the platen cover 20 and the platen 12. By providing the minute unevenness 33 on the surface of the platen cover 20, a gap can be created. By providing minute irregularities 32 also on the recording medium side of the platen cover 20, the contact area with the recording medium can be reduced, the frictional resistance can be further reduced, and smooth conveyance can be achieved. There are etching, blasting, polishing, painting, etc. as a method for processing the unevenness.
Further, the platen 12 may be uneven.

It can be used for the ink jet recording apparatus of the present invention.

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 2 Print recording device 3 Inkjet head 4 Carriage 5 Drive pulley 6 Driven pulley 7 Guide rail 8 Pressure roller unit 9 Transport roller 10 Transport device 11 Transport belt 12 Platen 13 Base 14 Ink cartridge 15 Suction chamber 16 Suction fan 17 Recording medium 18 Drive motor 19 Communication hole 20 Platen cover 21 Magnet 24 Fixing hole 23 Screw 27 Heater groove 28 Heater wire 31 Suction hole

Claims

A conveyance device that conveys a recording medium, a recording head that includes a plurality of nozzles for ejecting ink, a flat platen having a plurality of suction holes on a surface facing the recording medium, and the recording medium A suction unit that communicates with the suction hole; and a plate-like platen cover that is disposed on the platen and includes a plurality of communication holes that communicate with the front and back sides. The suction hole communicates the recording medium via the communication hole. An inkjet recording apparatus that sucks and conveys the recording medium while adsorbing the recording medium to the platen cover,
A fixing means for fixing the platen cover to the platen;
The fixing means is a magnet placed in a recess provided in the platen, the recording head side of the magnet is configured flat, and a screw hole communicating with the back surface of the platen is provided at the bottom of the recess. The screw is disposed in the screw hole, the tip of the screw comes into contact with the magnet, the magnet is moved up and down by rotating the screw, and the flat surface of the magnet and the surface of the platen An ink jet recording apparatus, wherein the platen cover is prevented from bending at the fixing means by matching the heights, and the platen cover is attracted by the magnet.
When the aperture ratio per unit area of the communication hole of the platen cover is higher than the aperture ratio of the suction hole per unit area of the platen, and when the platen cover is fixed on the platen by the fixing means The inkjet recording apparatus according to claim 1, wherein a plurality of openings of the communication holes are arranged in the openings of the suction holes.
An area where recording is not performed on the recording medium by the recording head,
The movement preventing means for fixing the platen is disposed at a portion of the platen cover that does not face the recording head so that the platen cover does not move as the recording medium is conveyed. The ink jet recording apparatus according to claim 1 or 2.
The inkjet recording according to any one of claims 1 to 3, wherein the platen cover is provided with irregularities in order to provide a minute space between the platen and the platen cover. apparatus.
The inkjet recording apparatus according to any one of claims 1 to 4, wherein a side of the platen cover facing the platen is covered with a sheet-like magnet.