JP4931724B2 - Inkjet recording device - Google Patents

Description

The present invention relates to a recording apparatus having a platen, in particular, it relates to an ink jet recording equipment for forming an image on a mesh-like recording medium.

  In an inkjet printer, ink can be ejected from an inkjet head and characters and images can be recorded on a wide variety of print media. For example, there is one that records images and characters on a sheet-like printing medium such as vinyl chloride or tarpaulin using a solvent ink as a paint. In addition, these print media are sometimes used outdoors, and tarpaulins are used for building cover sheets and signboards. Further, there are mesh-like objects in the print media. The ink jet printer can also print characters and images by ejecting ink onto a mesh-like medium. However, when a mesh-like print medium is used, there is a problem that ink passes through the print medium and stains the platen, and the dirt also stains the back surface of the print medium.

  Conventionally, polyester non-woven fabric is used as a slip sheet, and this slip sheet is placed between the back side of the printing media and the platen, transported with the printing media, and the penetrating ink is absorbed by the slip sheet. It was avoiding by letting.

Japanese Patent Laid-Open No. 2002-337405 discloses an ink jet printer in which one or more portions of a printing ink landing surface of a platen are cut out in a concave shape, and an ink absorbing member made of an ink absorbing material is attached to the concave portion. It is disclosed. The ink penetrating the print medium is absorbed by the ink absorbing material in the concave portion to prevent the ink from adhering to the back surface of the print medium. In this ink jet printer, the platen is detachable and the ink absorbing material is exchangeable.
JP 2002-337405 A

  In the conventional method, when the interleaving paper is transported along with the printing medium, the same amount of interleaving paper as the printing media is required, and the printing media becomes heavy and large. It is necessary to transport the print media and the interleaving paper in an overlapping manner, or to separate the print media and the interleaving paper after printing, and the mounting and handling properties of the print media to the ink jet printer are poor.

  Further, when a printer is used in which a concave portion is provided on the platen and an ink adsorbing member is adhered thereto, the platen becomes a dedicated platen using an ink absorbing material. Some print media tend to bend and wrinkle on the printing surface, and wrinkles and bends in the concave portion, making it difficult to print. In addition, when replacing the platen, the platen with the concave portion must be removed and a flat surface platen must be attached, resulting in poor handling of the printer. Further, the ink adhering to the ink absorbing material is not immediately dried, and the handling property is inconvenient and inconvenient such as a problem that the ink adhering to the media or the operator when the printing medium is replaced or the ink absorbing material is replaced.

As means for solving the above-mentioned problems, a first aspect of the present invention includes a transport unit that transports a print medium, an ink jet head that discharges ink to the print medium transported by the transport unit, and the ink jet head. A carriage that moves in a direction perpendicular to the conveyance direction, a platen that is disposed at a position facing the ink jet head and has a suction hole for sucking the print medium, and a distance between the platen and the ink jet head Elevating means for changing the elevating means, operating means for operating the elevating means, a heater disposed on the platen, and drive control means for driving the heater and controlling the temperature of the heater. Means is a platen driving means that contacts the opposite side of the platen to the inkjet head. The platen driving means includes a cam that is in contact with the platen, and a shaft that rotates the cam. The operating means is connected to the shaft, and the shaft is rotated by operating the operating means. The distance between the platen and the inkjet head is changed by changing the position of the platen that is in contact with the cam, and the drive control means adjusts the temperature of the heater according to the operation of the operation means. In a variable inkjet recording apparatus, the platen is lowered in a direction away from the inkjet head and the conveyance surface, a tray is disposed in the lowered portion, and the tray is sucked through the suction hole to be fixed to the platen. When the print medium is a mesh medium, the mesh medium is discharged from the inkjet head. Receiving the ink passing through the A in the tray, by heating the tray by the heater, an ink jet recording apparatus according to claim Rukoto to promote vaporization of the ink.

According to a second aspect, in the first aspect, the ink jet head further includes a head position adjusting unit that varies a distance from the platen of the ink jet head, the head position adjusting unit being interlocked with the operation unit, and When the head is moved in a direction away from the head, the head position adjusting unit moves the ink-jet head in a direction away from the platen.

A ninth aspect is an ink jet recording apparatus according to the first aspect or the second aspect, further comprising a media guide that presses both ends of the print medium, and printing while pressing both ends of the print medium. is there.

  In the present invention, the back surface of the print medium is prevented from being soiled by ink that has passed through the print medium. Further, the ink that has passed through the print medium is collected in the tray and prevents the back surface of the print medium from being stained. Furthermore, since the ink accumulated in the tray is heated by the heater and can be quickly evaporated, it is possible to prevent the back surface of the print medium from being stained. In addition, since the platen can be moved up and down, mesh-shaped print media is used when the platen is lowered to prevent contamination of the back side of the print media, and when the platen is raised, the print media is adsorbed to the platen. High quality printing is possible.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a main configuration of an ink jet recording apparatus according to the present invention. FIG. 2 is a partially enlarged view of a sectional view showing the configuration of the ink jet recording apparatus of the present invention. The configuration of the ink jet recording apparatus 20 will be described with reference to FIGS. 1 and 2. The ink jet recording apparatus 20 is a recording apparatus that forms an image on the print medium 19. The head 1 is fixed to a carriage 2, and the carriage 2 is fixed to a rail 3 so as to be movable. The carriage 2 is moved along the rail 3, the print medium 19 is conveyed by the conveyance roller 9 and the pinch roller 10, and ink is ejected from the head 1, thereby forming an image on the print medium 19. The first platen 6 is installed on the platen support arm 11 so that the first platen 6 can move to and away from the head 1 at a position facing the head 1. Further, the carriage 2 is provided with a head height adjusting rail 21 that adjusts the height of the head 1 so that the head 1 can be moved to and away from the first platen 6.

  The print medium 19 before printing is wound around the supply roller 15. The printing medium 19 after printing is wound and stored by the winding roller 14.

  When the conveyance roller 9 is driven to rotate, the pinch roller 10 that is in pressure contact with the conveyance roller 9 is rotated. The print medium 19 is sandwiched between the conveyance roller 9 and the pinch roller 10 and is conveyed by a necessary amount. The print medium 19 is tensioned by a supply tension roller 17 to apply a predetermined tension between the supply roller 15 and the transport roller 9 so that the medium does not wrinkle. Further, between the conveying roller 9 and the winding roller 14, pressure is applied in the direction in which the printing medium 19 is stretched by the winding tension roller 16, that is, in the conveying direction so that the printing medium 19 is not wrinkled.

  The first shaft 22 and the second shaft 23 are rotatably attached to the platen support arm 11. The first cam 4 is fixed to the first shaft 22, and when the first shaft 22 rotates, the first cam 4 rotates in conjunction with it. A plurality of the first cams 4 are preferably arranged in the extending direction of the first shaft 22. The second cam 5 is fixed to the second shaft 23, and when the second shaft 23 rotates, the second cam 5 rotates in conjunction with it. A plurality of second cams 5 are preferably arranged in the extending direction of the second shaft 23. Backlash can be prevented by supporting the first platen 6 with a plurality of cams.

  The platen includes three parts: a first platen 6, a second platen 7, and a third platen 8. The first platen 6 can be moved away from and in contact with the head 1, but the second platen and the third platen are fixedly installed on the platen support arm 11. Although the first platen 6 is at a position facing the head 1, the second platen 7 and the third platen 8 are not facing the head 1 and are disposed at positions facing the carriage 2. The first platen 6 is in contact with the first cam 4 and the second cam 5 on the side opposite to the head 1, that is, the back surface. The first cam 4 and the second cam 5 are eccentric and rotate to move the first platen 6 upward and downward.

  A plurality of through holes are formed in the first platen 6, the second platen 7, and the third platen 8. A suction box 12 is disposed below the first platen 6, the second platen 7, and the third platen 8, and a fan 13 is attached to the suction box 12. The print medium 19 can be sucked to the first platen 6, the second platen 7, and the third platen 8 by lowering the air pressure in the suction box 12 by the fan 13. By conveying the print medium 19 while sucking it, it is possible to eject ink with the distance between the head 1 and the print medium 19 being constant, so that the manner in which the ink adheres is constant and an image with good image quality is obtained. Can be formed.

  These components are attached to the frame 18 and constitute an ink jet recording apparatus 20.

  Next, the elevation state of the platen will be described with reference to FIGS. FIG. 3 is a cross-sectional view showing the rising state of the platen of the ink jet recording apparatus of the present invention. FIG. 4 is a sectional view showing the lowered state of the platen of the ink jet recording apparatus of the present invention. When printing on the mesh-shaped print medium 19, ink passes through the print medium 19 and adheres to the platen, not only soiling the platen but also the back surface of the print medium 19. Therefore, when the mesh-shaped print medium 19 is used, the first platen 6 facing the head 1 is brought to the lowered position, and a tray or an ink absorbing material is placed on the first platen 6 so that the ink is on the back surface of the print medium 19. Not to get dirty. When using a printing medium 19 that is not mesh-shaped, the first platen 6 is placed in the raised position and printing is performed on the printing medium 19.

  FIG. 3 is a view when the first platen 6 is in the raised position. The first platen 6 is lifted by the first cam 4 and the second cam 5. In printing in this state, the fan 13 operates and the air pressure in the suction box 12 decreases, so that air is sucked into the suction box 12 through the suction holes 25. The heater 26 maintains a predetermined temperature setting value at the time of printing. The media guide 24 presses both side ends of the print medium 19 so that the print medium 19 is not curled.

FIG. 4 is a view when the first platen 6 is in the lowered position. The first platen 6 is lowered by the first cam 4 and the second cam 5. Since the first platen 6 is pulled by a spring in the direction of the platen support arm 11, the position of the first platen 6 moves depending on the position where the cam contacts. Printing in this state corresponds to printing on a mesh print medium.
In the case of a mesh-shaped print medium, the operation of the fan 13 is stopped because suction is not performed on the platen. Further, the heater 26 is variable to a predetermined temperature setting value at the time of printing on the mesh-shaped print medium.

  In the case of a mesh-shaped print medium, since it is not sucked by the platen, both ends are pressed by the media guide 24 so that the print medium 19 is not curled. Further, printing is performed while applying tension to the print medium in the transport direction. Further, the head 1 is moved in the direction of the arrow 27, that is, in the direction away from the platen. In the case of mesh-shaped print media, since it is not sucked by the platen, the position of the print media floats from the platen compared to when the print media is sucked, and comes into contact with the head 1, so that the head 1 moves away from the platen. And printing while preventing contact.

  FIG. 5 is a sectional view showing another lowered state of the platen of the ink jet recording apparatus of the present invention. The tray 28 is disposed at a position where the first platen 6 is lowered. Ink is stored in the tray 28, the first platen 6 is heated by the heater 26, and the ink stored by the heat transmitted to the tray 28 is further vaporized. Further, by operating the fan 13, the tray 28 is attracted to the first platen 6 by the suction hole 25, so that the tray 28 is prevented from coming into contact with the print medium 19 and the head 1 during printing. Further, instead of the tray 28, a non-woven ink absorbing material can be laid. In this case, the ink absorbing material can be sucked to the first platen by sucking, and the back side of the printing medium 19 can be drawn. Ink can be prevented from adhering. Heating by the heater 26 accelerates ink vaporization, makes it difficult for ink to adhere to the back surface of the print media, and further facilitates handling of the tray 28 and the print media 19 by drying the ink.

  FIG. 6 is a perspective view showing a state where printing is performed on a print medium of the ink jet recording apparatus of the present invention. The carriage 2 reciprocates along the rail 3 and prints on the print medium 19. A first platen 6 is disposed facing the moving surface of the carriage 2, and a media guide 24 is installed so as to straddle the first platen 6. The media guide 24 presses both side edges of the print medium 19 to prevent it from curling. In particular, when the mesh-shaped print medium 19 is used, since suction by the platen is not performed, it is necessary to press both ends of the print medium 19 with the media guides 24. Further, printing is performed while the print medium 19 is pulled in the transport direction and is always stretched. Printing is performed with the interval between the print medium 19 and the head 1 as constant as possible to improve the quality of the print image.

  FIG. 7 is a block diagram showing the configuration of the ink jet recording apparatus of the present invention. The CPU 29 is a control unit that operates based on a program stored in the ROM 30 and controls the operation of the entire apparatus. The ROM 30 is a non-volatile memory and stores various setting values such as a temperature setting according to a program and printing conditions, and a condition value with and without suction. The RAM 31 stores a work area for calculation by the CPU 29 and temporary data. The LCD 32 controls the CPU 29 to display data such as input instructions and messages to the user. The switch 33 is an input unit that performs an input operation of the inkjet recording apparatus 20.

  The heater 26 is a heater that heats the first platen 6. The heater 26 varies the heating temperature according to the drive signal of the heater drive circuit 34. The heater drive circuit 34 is controlled by the CPU 29. The fan 13 operates according to the drive signal of the fan drive circuit 35. The fan drive circuit 35 is controlled by the CPU 29. The first platen 6 is moved up and down by the platen driving means 40. The platen drive means 40 is driven by the operation of the platen position instruction means 36. The platen position instruction means 36 outputs a signal indicating whether the first platen 6 is in the raised position or the lowered position to the CPU. Further, the head position adjusting means 41 operates in conjunction with the operation of the platen position instruction means 36.

  The head position adjusting means 41 moves the carriage 2 along the head height adjusting rail 21 in order to change the head height. When the first platen 6 is in the lowered position, the carriage 2 is slid in a direction away from the first platen 6. When the first platen 6 is in the raised position, the carriage 2 is slid in a direction approaching the first platen 6. This is because when the mesh-shaped print medium 19 is used, suction does not occur, so that the position of the head 1 is moved away from the print medium 19 in advance so that the print medium 19 is not turned and collides with the head 1 during printing.

  The carriage drive circuit 37 reciprocates the carriage 2 along the rail 3 based on a control signal from the CPU 29. The head drive circuit 38 drives the head 1 based on a control signal from the CPU 29 and ejects ink. The conveyance roller drive circuit 39 drives the conveyance roller 9 based on a control signal from the CPU 29 and conveys the print medium 19.

  Next, an operation when the first platen 6 is raised and lowered will be described. FIG. 8 is a flowchart showing the operation of the ink jet recording apparatus of the present invention. When the operation of raising and lowering the first platen 6 is performed by the platen position instruction unit 36, the print preparation process S1 starts.

  An input value indicating whether the first platen 6 is in the raised position (position away from the head 1) or the lowered position (position approaching the head 1) is input to the CPU 29 (processing S2).

  Next, it is determined whether or not the input value is a position away from the head. If the position is away, the process proceeds to step S4. If the position is closer, the process proceeds to step S11 (process S3).

  In the process S4, when the first platen 6 moves to a position away from the head 1, the fan 13 is stopped. The CPU 29 outputs a control signal for stopping the fan to the fan drive circuit 35, and the fan drive circuit 35 stops the fan 13. Suction is stopped. Next, in process 5, the CPU 29 outputs a control signal for changing the heater temperature to the heater drive circuit 34, in this case, a control signal for increasing the temperature. The heater drive circuit 34 increases the temperature of the heater 26. In order to quickly evaporate the ink accumulated in the tray 28, control is performed to raise the temperature.

  Next, in process 11, when the first platen 6 moves to a position approaching the head 1, the fan 13 is operated. The CPU 29 outputs a control signal for operating the fan to the fan drive circuit 35, and the fan drive circuit 35 operates the fan 13. Suction starts. Next, in process 12, the CPU 29 outputs a control signal for changing the heater temperature to the heater drive circuit 34, in this case, a control signal for lowering it.

  Next, in step S6, a head position confirmation display is performed. The CPU 29 displays the current state by the operation input made by the platen position instruction means 36. The fan 13 displays an operating state, a heater temperature, a position of the first platen 6 and a position of the head 1, and the user confirms this. If there is no problem, the user inputs an operation for starting printing using the switch 33 (step S7).

  Next, in step S8, it is determined whether or not the input is a switch for starting printing, and if it is an instruction to start printing, the process proceeds to step S9 to start the printing process, and proceeds to process S10 to end the print preparation process. Let If it is not an instruction to start printing, the process proceeds to step S10 to end the process for resetting again, and the print preparation process is ended.

  As another aspect, the operation of the fan 13 can be controlled by the presence or absence of the tray 28 when the first platen 6 is in the lowered state. When there is a tray 28, the operation is continued without stopping the fan 28, and when there is no tray 28, the fan 28 is stopped. By doing so, the tray 28 can be sucked to the first platen 6 and can be closely contacted so that heat can be easily transmitted, and rattling of the tray 28 can be prevented. This control can also be used when an ink absorbing material is used instead of the tray 28. Further, the tray 28 can be determined whether or not the tray 28 is present by using detection means or input means for inputting presence or absence.

  FIG. 9 is a block diagram showing a first configuration for driving the platen of the ink jet recording apparatus of the present invention. The platen position instruction means is a lever 36 and operates between the A position and the B position. The A position indicates the rising position of the first platen 6, and the B position indicates the lowering position of the first platen. The lever 36 can be fixed at the A position and the B position.

  The lever 36 is connected to the first shaft 22 via the gear 42, and the first shaft 22 rotates by operating the lever 36. The first shaft 22 is linked to the second shaft 23 and rotates in conjunction with it. When the first cam 4 installed on the first shaft 22 and the second cam 5 installed on the second shaft 23 rotate, they are in contact with the first cam 4 and the second cam 5. The first platen 6 moves up and down. Here, the platen support arm 11 is provided with a lock mechanism (not shown) that supports the first platen with a spring so as to be movable in the direction of separation from the head 1 and locks the lever 36 at the A and B positions. The position of the first platen 6 may be fixed.

  FIG. 10 is a block diagram showing a second configuration for driving the platen of the ink jet recording apparatus of the present invention. For example, when the first platen 6 is operated from the platen position support means 36 such as a switch to the up position or the down position, a signal corresponding to the operation enters the CPU, and the CPU 29 sends a control signal to the motor drive circuit 43 based on the signal. Is output. The motor drive circuit 43 rotates the motor 44. The first shaft 22 is rotated by the rotation of the motor 44. The second shaft 23 is linked to the first shaft 22 and rotates in conjunction therewith. When the first cam 4 installed on the first shaft 22 and the second cam 5 installed on the second shaft 23 rotate, they are in contact with the first cam 4 and the second cam 5. The first platen 6 moves up and down. Based on the operation of the platen position support means 36, the motor 44 rotates, and the first platen 6 moves up and down to a predetermined position by the rotation.

  FIG. 11 is a block diagram showing a third configuration for driving the platen of the ink jet recording apparatus of the present invention. This is an example in which slide means is used as lifting means for the first platen 6. As the sliding means, a male screw and a female screw are used. By rotating one screw, the other screw is slid and the first platen 6 fixed to the other screw is moved up and down.

  When the platen position instructing unit 36 is operated to set the first platen 6 to the raised position or the lowered position, one of the signals enters the CPU 29. Based on the signal input by the CPU 29, control for rotating the motor 44 in a desired rotation direction is performed. The CPU 29 outputs to the motor drive circuit 43 a drive control signal indicating whether the rotation is right rotation or left rotation calculated based on the input signal. The motor 44 rotates based on the drive signal of the motor drive circuit 43. The rotation of the motor 44 is transmitted to a support plate screw 45 that is rotatably attached to the platen support arm 11 side. The support plate screw 45 rotates on the spot. The platen screw 46 fixed to the first platen 6 is installed so as to engage with the support plate screw 45. The first platen 6 is attached to the platen support arm 11 so as to be slidable in the vertical direction. The second platen 7 and the third platen 8 are fixed to the platen support arm 11, and the first platen 6 is disposed so as to be movable up and down therebetween. When the support plate screw 45 rotates, the platen screw 46 and the first platen 6 engaged with each other move up and down depending on the direction of rotation.

  FIG. 12 is a cross-sectional view showing the state of the tray of the ink jet recording apparatus of the present invention. When printing on a mesh-shaped print medium, ink passes through the gap of the print medium and reaches the tray 28. The tray 28 is laid with an absorbent material 47 that absorbs ink up to about half the depth. Ink reaches the ink absorbing material 47 and ink droplets 48 adhere to the ink absorbing material 47. The adhering ink droplet 48 is transferred from the first platen 6 heated by the heater 26 in the direction of the arrow 49, and heats the ink droplet 48 via the tray 28 and the absorbing material 47. The ink droplet 48 is vaporized by heat. The absorbent material 47 is preferably a nonwoven fabric that absorbs ink.

Further, laying the absorbent material 47 on the tray 28 prevents the ink from splashing back on the tray 28 and soiling the back surface of the print media, facilitates the processing of the ink after drying, and prevents the ink from scattering. Because of that. The tray 28 preferably has a shape in which the uneven shape on the front surface of the first platen and the uneven shape on the back surface of the tray 28 are engaged with each other in order to transfer heat from the first platen 6 well. Further, it is preferable that the surface of the tray 28 is colored black in order to transfer heat well. The tray 28 is preferably made of metal, preferably the same material as the first platen, or an aluminum alloy in order to transfer heat well.

FIG. 2 is a cross-sectional view schematically illustrating a main configuration of the ink jet recording apparatus according to the invention. FIG. 3 is a partially enlarged view of a cross-sectional view showing the configuration of the ink jet recording apparatus of the present invention. It is sectional drawing showing the rising state of the platen of the inkjet recording device of this invention. It is sectional drawing showing the fall state of the platen of the inkjet recording device of this invention. It is sectional drawing showing another fall state of the platen of the inkjet recording device of this invention. It is a perspective view showing the state currently printing on the printing medium of the inkjet recording device of this invention. It is a block diagram showing the structure of the inkjet recording device of this invention. 3 is a flowchart showing the operation of the ink jet recording apparatus of the present invention. FIG. 2 is a configuration diagram showing a first configuration for driving a platen of the ink jet recording apparatus of the present invention. It is a block diagram showing the 2nd structure which drives the platen of the inkjet recording device of this invention. It is a block diagram showing the 3rd structure which drives the platen of the inkjet recording device of this invention. It is sectional drawing showing the state of the tray of the inkjet recording device of this invention.

Explanation of symbols

1 Inkjet head 2 Carriage 3 Rail 3
4 1st cam 5 2nd cam 6 1st platen 7 2nd platen 8 3rd platen 9 Conveyance roller 10 Pinch roller 11 Platen support arm 12 Suction box 13 Fan 14 Winding roller 15 Supply roller 16 Winding Tension roller 17 Supply tension roller 18 Frame 19 Print media 20 Inkjet recording device 21 Head height adjustment rail 22 First shaft 23 Second shaft 24 Media guide 25 Suction hole 26 Heater 27 Arrow 28 Tray 42 Gear 45 Support plate screw 46 Platen screw 47 Absorbent 48 Ink drop 49 Arrow 50 Arrow

Claims (3)

A transport unit configured to transport a print medium; an inkjet head that ejects ink to the print medium transported by the transport unit; a carriage that mounts the inkjet head and moves in a direction perpendicular to the transport direction; and the inkjet head A platen provided with a suction hole that is disposed at a position facing the print medium and sucks the print medium ;
Elevating means for varying the distance between the platen and the inkjet head;
Operating means for operating the elevating means;
A heater disposed on the platen;
Drive control means for driving the heater and controlling the temperature of the heater;
The elevating means has platen driving means that contacts the opposite side of the platen to the inkjet head,
The platen drive means has a cam that contacts the platen, and a shaft that rotates the cam.
The operation means is connected to the shaft, and the distance between the platen and the inkjet head is changed by rotating the shaft by operating the operation means and changing the position of the platen in contact with the cam. Change
In the inkjet recording apparatus in which the drive control unit varies the temperature of the heater in accordance with the operation of the operation unit ,
The platen is lowered in a direction away from the inkjet head and the conveyance surface, a tray is disposed in the lowered portion, and the tray is sucked by the suction hole to be fixed to the platen,
When the print medium is a mesh-like medium, the ink that has been ejected from the inkjet head and penetrates the mesh-like medium is received by the tray, and the tray is heated by the heater, thereby vaporizing the ink. an ink jet recording apparatus according to claim Rukoto to promote.   The ink jet head further includes a head position adjusting unit that varies a distance from the platen, and the head position adjusting unit is linked to the operation unit, and when the platen is moved away from the ink jet head, The ink jet recording apparatus according to claim 1, wherein the head position adjusting unit moves the ink jet head in a direction away from the platen.   The inkjet recording apparatus according to claim 1, further comprising a media guide that presses both ends of the print medium, and performing printing while pressing both ends of the print medium.

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