Liquid dispensing device

Abstract

To provide a liquid discharge device which is applicable to a large size medium and increases drying performance of liquid ink.SOLUTION: A liquid discharge device comprises: a liquid discharge head for discharging liquid to a medium; a carriage equipped with the liquid discharge head; a guide rail which supports the carriage in such a manner that the carriage can be slid in a main scanning direction with respect to the medium; a rail holding part which supports the guide rail in such a manner that the guide rail can be moved in a sub-scanning direction; a first drying part which is mounted on the carriage and blows air in the direction in which the liquid is discharged; and a second drying part which is mounted on the guide rail and blows air in the direction in which the liquid is discharged.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a liquid ejection device.

Background Art

[0002] Liquid ejection devices that eject liquid toward a medium, adhere it, and form an image are known. Liquid ejection devices that form an image on large media such as the body of a vehicle or the wall surface of a building are also known.

[0003] In a liquid ejection device in which the liquid ejected onto the medium adheres to the medium by drying and is used for image formation, there is known a device provided with a heater as a drying device for drying the liquid ink adhering to the medium (see Patent Document 1).

Summary of the Invention

Problems to be Solved by the Invention

[0004] The device disclosed in Patent Document 1 is not assumed to be applied to image formation on large media such as vehicles. In addition, when forming an image on a large image area such as a vehicle, the liquid ink used is conventionally often a mixture containing volatile chemical components, and the environmental load of these chemical components is high. Therefore, in recent years, there has been an increasing demand for using aqueous liquid ink for the same applications.

[0005] However, compared with conventional liquid inks containing volatile components, aqueous ink requires a longer time to dry. Therefore, in the case of a large medium such as the housing of a vehicle, it takes time until drying is completed. Furthermore, the image formation surface of a large medium is not always a horizontal plane, and may be a vertical plane such as the wall surface of a building. Therefore, if drying is not performed more quickly, the liquid ink landing on the image formation surface will drip and the image quality will deteriorate.

[0006] If, for example, water-based ink were used as the liquid ink for forming an image on a large medium using the prior art disclosed in Patent Document 1, a higher temperature would be required than for conventional drying equipment, resulting in enormous energy consumption and a significant impact on the environment.

[0007] Therefore, there is a need for a liquid dispensing device that can handle large media and improve the drying speed of liquid ink.

[0008] The present invention aims to provide a liquid dispensing device that can handle large media and improves the drying properties of liquid ink. [Means for solving the problem]

[0009] To solve the above technical problems, one aspect of the present invention relates to a liquid dispensing device, comprising: a liquid dispensing head for dispensing liquid onto a medium; a carriage equipped with the liquid dispensing head; a guide rail that supports the carriage so as to be slidable in the main scanning direction relative to the medium; a rail holding part that holds the guide rail so as to be movable in the sub-scanning direction; a support column that supports the rail holding part; a first drying part mounted on the carriage and blowing air in the direction from which the liquid is discharged; and a second drying part mounted on the guide rail and blowing air in the direction from which the liquid is discharged. The first drying section is arranged on both sides of the liquid discharge head in the main scanning direction and comprises a first heat source and a first outlet that is tapered toward the medium and sends warm air from the first heat source toward the medium. The second drying section is provided on a rod-shaped member provided below the guide rail and is installed at one end of the rod-shaped member in the longitudinal direction and comprises a second heat source equipped with a blower that blows warm air into the internal space of the rod-shaped member and comprises a plurality of second outlets provided at predetermined intervals on the surface of the rod-shaped member facing the medium and sending warm air from the second heat source toward the medium through the internal space. It is characterized by being equipped with [the following features]. [Effects of the Invention]

[0010] According to the present invention, it is possible to handle large media and improve the drying properties of liquid ink. [Brief explanation of the drawing]

[0011] [Figure 1] A schematic diagram showing an embodiment of the liquid dispensing device according to the present invention. [Figure 2] This figure shows an example of the configuration of the liquid dispensing mechanism according to the above embodiment. [Figure 3] This figure shows an example of the configuration of the liquid dispensing mechanism according to the above embodiment. [Figure 4] This figure shows an example of the configuration of the liquid dispensing mechanism according to the above embodiment. [Figure 5] This figure shows an example of the configuration of the first drying section according to the above embodiment. [Figure 6] This figure shows an example of the configuration of the second drying section according to the above embodiment. [Figure 7] This figure shows another example of the configuration of the second drying section according to the above embodiment. [Figure 8] A figure showing an example of a liquid dispensing head according to the above embodiment. [Figure 9] A diagram showing another example of a liquid dispensing head according to the above embodiment. [Figure 10] A functional block diagram showing an example of a control unit according to the above embodiment. [Modes for carrying out the invention]

[0012] [Liquid Dispensing Device Embodiment] Hereinafter, embodiments of the liquid dispensing apparatus according to the present invention will be described with reference to the figures. As shown in Figures 1 to 3, the printer 1 according to this embodiment is applicable as an inkjet type image forming apparatus capable of forming images on a large object such as the body CB of a large vehicle. The following description will illustrate the case in which an image is formed on one side wall of the vehicle body CB as the image forming area IA, as shown in Figure 2.

[0013] In other words, printer 1 is a method of printing directly onto large areas such as the casings of large vehicles like trucks or the walls of buildings, without using wrapping media.

[0014] Note that the image formation area IA according to the present embodiment assumes a two-dimensional area standing vertically like the side wall of the vehicle body CB. However, the image formation area IA to which the printer 1 can be applied is not limited to the examples of the present embodiment. For example, using the same configuration as the printer 1, an image formation area IA can be assumed as a two-dimensional area such as a horizontal plane, and an image can be formed on the horizontal image formation area IA. The medium (image formation area IA) assumed in this case is, for example, a road or a floor.

[0015] The printer 1 mainly includes a carriage 10 equipped with a liquid ejection head 100, a guide rail 40 that slidably supports the carriage 10, a rail holding portion 30 supported by a support column 20 via a moving mechanism that moves the guide rail 40 in a direction orthogonal to the sliding direction of the carriage, and a support column 20 that supports the rail holding portion 30 via a moving mechanism that moves the rail holding portion 30 in a direction orthogonal to the sliding direction of the carriage.

[0016] The support column 20 is a pair of columnar members that can be erected near the vehicle body CB as a medium. The first support column 21a and the second support column 21b configured as a pair are installed at a predetermined interval in the longitudinal direction of the vehicle body CB. This installation interval is wider than the width dimension of the image formation area IA. The support column 20 includes a rail holding portion 30 for suspending the guide rail 40 toward the vehicle body CB as a medium on a part of its side surface. The support column 20 includes a rail holding portion moving mechanism 21 that allows the rail holding portion 30 to move in the height direction (the longitudinal direction of the support column 20) by the control unit 150.

[0017] The rail holding portion 30 has a first rail holding portion 31a held by the first support column 21a and a second rail holding portion 31b held by the second support column 21b. The guide rail 40 is suspended between the first rail holding portion 31a and the second rail holding portion 31b.

[0018] The rail holding part 30 is a member for holding the guide rail 40 at a predetermined height position with respect to the support column 20. And the rail holding part 30 is supported by the support column 20 via a rail holding part moving mechanism 21 that can change the height position with respect to the support column 20 under the control of a control part 150 described later. The rail holding part 30 corresponds to a sub-scanning direction moving means for making the guide rail 40 movable in the sub-scanning direction of the image forming area IA so that the carriage 10 performs sub-scanning.

[0019] Here, the main scanning direction and the sub-scanning direction according to this embodiment will be described. When performing image formation, while moving the carriage 10 two-dimensionally at a position away from a certain process in the image forming area IA, liquid is ejected from the liquid ejection head 100. As shown in FIG. 2, the sliding direction of the carriage 10 is the direction of the installation interval of the support columns 20. If the axis in this direction is the X-axis, the X direction becomes the main scanning direction. While the carriage 10 changes its position in the main scanning direction, the liquid ejection head 100 ejects liquid toward the image forming area IA at a predetermined timing.

[0020] Also, since the rail holding part 30 is held via a mechanism movable in the longitudinal direction of the support column 20, the moving direction of the guide rail 40 is also the longitudinal direction of the support column 20. If the axis in this direction is the Y-axis, the Y direction becomes the sub-scanning direction. While the guide rail 40 changes its position in the sub-scanning direction, at the position in the sub-scanning direction, the carriage 10 performs main scanning along the guide rail 40. Therefore, due to the movement of the guide rail 40, the carriage 10 moves in a direction orthogonal to the main scanning direction, and at the moving destination, the liquid ejection head 100 ejects liquid while moving in the main scanning direction. As described above, the liquid ejection head 100 can move two-dimensionally with respect to the image forming area IA and eject liquid to form an image.

[0021] The guide rail 40 is a type of columnar member that movably supports the carriage 10, and as will be described later, it is a hollow columnar member. A part of the low-temperature hot air heater 410, which serves as a second drying section, is mounted on one end of the guide rail 40 in the longitudinal direction. As will be described later, the guide rail 40 is configured to blow out the heat released by the heat source of the low-temperature hot air heater 410 as low-temperature hot air towards the image forming area IA. The low-temperature hot air heater 410 consists of a heat source and a configuration for blowing out hot air.

[0022] Furthermore, as shown in Figure 1, the printer 1 is configured to control the image forming process by installing, for example, a control device 15 equipped with a control unit 150 near the support column 20, and an operation terminal 16 for operating the control device 15. The control unit 150 controls the movement of the rail holding unit 30 in the sub-scanning direction and the movement of the carriage 10 in the main scanning direction. In addition, the discharge operation of the liquid discharge head 100 is controlled in conjunction with these movements and timing. Furthermore, the control unit 150 also controls the operation of the high-temperature hot air heater 110 and the low-temperature hot air heater 410, which will be described later. Details of the control unit 150 will be described later.

[0023] [Carriage 10 Details] As shown in Figure 3, the carriage 10 is supported by a guide rail 40 held by a rail holding section 30, and discharges liquid at a predetermined position on the vehicle body CB. The guide rail 40 has a mechanism that allows the distance from the image forming area IA to be changed relative to the rail holding section 30. That is, it holds the carriage 10 so that it can move in the Z-axis direction. With this mechanism, even if the image forming area IA has irregularities, a suitable image forming environment can be obtained by adjusting the liquid discharge distance.

[0024] Therefore, the carriage 10 is configured to be able to move freely in two dimensions relative to the image forming region IA, and the guide rail 40 held by the rail holding portion 30 can adjust the distance of the liquid flight by changing the distance from the image forming region IA, thereby maintaining favorable discharge characteristics.

[0025] Figure 4 is a plan view of the carriage 10 as seen from the Y direction. The carriage 10 is equipped with a liquid discharge head 100 for discharging liquid. Details of the liquid discharge head 100 will be described later. The carriage 10 is also equipped with a high-temperature hot air heater 110 as a first drying unit. The high-temperature hot air heater 110 moves in conjunction with the movement of the carriage 10 in the main scanning direction. The high-temperature hot air heater 110 is configured to blow hot air in the direction of liquid discharge.

[0026] The high-temperature hot air heaters 110 are arranged on both sides of the main scanning direction in the carriage 10, for example, with the liquid discharge head 100 in between, and a first high-temperature hot air heater 110a mounted on one side of the carriage 10 and a second high-temperature hot air heater 110b mounted on the other side.

[0027] Assume that the carriage 10 is moving in the direction of the arrow on the X axis (from left to right when facing directly in Figure 4). In this case, first, the image forming region IA is heated by the high-temperature hot air blown from the second high-temperature hot air heater 110b, and the liquid discharge head 100 discharges liquid into the heated region. After that, the first high-temperature hot air heater 110a blows high-temperature hot air into the region where the liquid was discharged. In this way, as the carriage 10 moves, the temperature of the image forming region IA where the liquid ink is about to land is raised to improve the adhesion of the liquid ink. Then, after the liquid ink has landed on the image forming region IA, high-temperature hot air is blown onto the surface of the liquid ink to quickly dry it and prevent it from dripping vertically on the image forming region IA. In this way, the temperature can be quickly raised before and after the liquid ink lands to improve adhesion and drying properties.

[0028] Therefore, the high-temperature hot air heater 110 has the function of warming the position of the image forming area IA to which the liquid discharged by the liquid discharge head 100 is to adhere, and the function of drying the position of the image forming area IA to which the liquid discharged by the liquid discharge head 100 has adhered. However, if the adhesion and drying of the liquid ink can be performed in a suitable state without prior heating, then only one of the functions (second high-temperature hot air heater 110b) is required.

[0029] [Details of the first drying section] Figure 5 shows a perspective view (a) and a plan view (b) illustrating the high-temperature hot air heater 110 as the first drying unit. The high-temperature hot air heater 110 has a first heat source 111 mounted inside the housing and a first outlet 112 for directing and discharging the hot air from the first heat source 111 in a predetermined direction.

[0030] The first heat source 111 includes a heater to which an electric heating wire or the like is applied, and a blower (fan) that sends out the heat from the heater. The heating operation and blowing operation are controlled by the control unit 150. For example, when the carriage 10 is outside the image forming area IA (outside the image forming area), that is, when it is outside the main scanning range, there is no need to heat up. Therefore, when the carriage 10 moves to the corresponding position, the operation of the first heat source 111 is turned off. Then, when the carriage 10 is in a position facing the image forming area IA due to the main scanning operation, the operation of the first heat source 111 is controlled to be turned on.

[0031] As shown in Figure 5(b), the first outlet 112 is tapered in the direction of discharge. This first outlet 112 is directed toward the image forming region IA. In other words, the high-temperature hot air heater 110 is configured to blow out high-temperature hot air in the same direction as the liquid discharge direction, and has the effect of narrowing the airflow so that the hot air flow does not adversely affect the flight space of the discharged liquid until it hits the image forming region IA.

[0032] The high-temperature hot air heater 110 is configured to blow hot air at a higher temperature than the low-temperature hot air heater 410 (described later) toward the image forming region IA, and its temperature is approximately 150°C near the outlet.

[0033] By incorporating the high-temperature hot air heater 110 with the above configuration, the liquid ink can be quickly dried while the position of the hot air outlet moves in conjunction with the movement of the carriage 10. Furthermore, the first heat source 111 can be turned off in conjunction with the position of the carriage 10 when drying is not required. By performing this control, it is possible to maintain the quality of image formation for the large image forming area IA while suppressing power consumption.

[0034] [Details of the second drying section] Figure 6 is a perspective view illustrating the low-temperature hot air heater 410 as a second drying section. As shown in Figure 6, the low-temperature hot air heater 410 is configured to include a second heat source 411 and a plurality of second outlets 412 arranged in the longitudinal direction of the guide rail 40 as outlets for low-temperature hot air.

[0035] The second heat source 411 includes a heater to which an electric heating wire or the like is applied, and a blower (fan) that sends out the heat from the heater, and the heating operation and blowing operation are controlled by the control unit 150. The second heat source 411 is provided at the longitudinal end of the guide rail 40 and is configured to blow low-temperature warm air into the internal space of the guide rail 40.

[0036] The second outlets 412 are provided in multiple locations at predetermined intervals on the side surface of the guide rail 40, facing the image forming region IA. The second outlets 412 send warm air from the second heat source 411 toward the image forming region IA. Since the second outlets 412 are formed over a width equivalent to that of the image forming region IA, the warm air blown out from the low-temperature warm air heater 410 contributes to warming and drying the entire width of the image forming region IA.

[0037] The position from which liquid can be discharged from the second outlet 412 changes as the position of the carriage 10, which is held by the guide rail 40, moves. That is, since a part of the second outlet 412 is blocked by the carriage 10, when the liquid discharge head 100 discharges liquid while the carriage 10 moves in the main scanning direction, the warm air from the second outlet 412 located around it is blocked.

[0038] By having the carriage 10 function as a shielding member for the low-temperature hot air heater 410, when the low-temperature hot air is blown in the same direction as the liquid discharge direction, the airflow of the hot air does not adversely affect the flight space of the discharged liquid until it hits the image forming region IA.

[0039] The low-temperature hot air heater 410 is configured to blow out hot air at a lower temperature than that of the high-temperature hot air heater 110 toward the image forming region IA, and its temperature is approximately 100°C near the outlet.

[0040] Figure 7 shows another configuration example of the low-temperature hot air heater 410. As shown in Figure 7, the low-temperature hot air heater 410 may be provided on a rod-shaped member 41 separate from the guide rail 40. The rod-shaped member 41 is fixed to the bottom side of the guide rail 40 and is held below the guide rail 40 in the sub-scanning direction.

[0041] If a low-temperature hot air heater 410 is provided on the rod-shaped member 41, for example, suppose that image formation starts from above in the image forming region IA. In this case, the temperature of the image forming region IA is raised by the low-temperature hot air heater 410 before the liquid ink ejection operation in the main scanning direction. Therefore, when the guide rail 40 moves downward in the sub-scanning direction, and the carriage 10 moves in the main scanning direction at that height, and the liquid ejection head 100 ejects the liquid, drying can be achieved even more quickly.

[0042] Furthermore, since the height position of the carriage 10 in the main scanning direction and the airflow position from the low-temperature hot air heater 410 are different in the height direction, the possibility of the airflow from the low-temperature hot air heater 410 adversely affecting the liquid flight space can be further reduced.

[0043] By incorporating the low-temperature hot air heater 410 having the above configuration, it is possible to continuously blow hot air in the main scanning direction of the image forming area IA without disturbing the airflow in the liquid flight space due to the movement of the carriage 10. This promotes the drying of the liquid ink. Furthermore, in order to further dry the liquid ink that has been quickly fixed by the high-temperature hot air heater 110, the system is configured to allow drying to be performed continuously in the main scanning direction. This allows for rapid drying of the large image forming area IA while suppressing power consumption, thereby maintaining the quality of image formation.

[0044] [Liquid Dispensing Head 100 Embodiment] Figure 8 shows an example of a liquid discharge head 100 applicable to this embodiment, viewed from the discharge port side. Figure 9 shows another example of a liquid discharge head 100 applicable to this embodiment, viewed from the discharge port side.

[0045] As illustrated in Figures 8 and 9, the liquid discharge head 100 has a discharge surface in which a plurality of discharge ports are arranged in a predetermined direction. The plurality of discharge ports are distinguished by the color of the liquid ink, and for example, there is a nozzle 101Y for discharging yellow liquid ink, a nozzle 101M for discharging magenta liquid ink, a nozzle 101C for discharging cyan liquid ink, and a nozzle 101Bk for discharging black liquid ink.

[0046] The liquid ejection head 100 assigns each color of liquid ink to each row of nozzles 101 arranged in the sub-scanning direction (nozzle row), as illustrated in Figure 8, and arranges the nozzle rows corresponding to each color in the main scanning direction. As illustrated in Figure 8, the resolution of the image formed can be increased by arranging multiple nozzle rows corresponding to the same color. Furthermore, by using a similar arrangement, the amount of liquid ejected per main scan can also be increased. In addition, by setting one nozzle row to correspond to one color of liquid ink, it is possible to use liquid ink of a different color (for example, white ink), and pre-printing becomes possible.

[0047] Furthermore, the liquid ejection head 100 is arranged such that each nozzle 101 corresponding to each color of liquid ink is inclined with respect to both the main scanning direction and the sub-scanning direction, as illustrated in Figure 9. By adopting this arrangement, the resolution per main scan can be increased. Regardless of how the nozzles 101 are arranged, the operation of mounting them on the carriage 10 and ejecting the liquid ink at a predetermined timing is performed in the same way.

[0048] [Functional blocks of the control unit 150] Here, an example configuration of the control device 15 will be explained using Figure 10. As shown in Figure 10, the control device 15 has a configuration in which a CPU (Central Processing Unit) 151, RAM (Random Access Memory) 152, ROM (Read Only Memory) 153, HDD (Hard Disk Drive) 154, and I / F 155 are connected via a common bus 159.

[0049] The CPU 151 is the arithmetic unit and controls the overall operation of the control unit 15 and the printer 1. The RAM 152 is a volatile storage medium that allows high-speed reading and writing of information and is used as a workspace for the CPU 151 when processing information. The ROM 153 is a read-only, non-volatile storage medium that stores programs such as firmware. The HDD 154 is a non-volatile storage medium that allows reading and writing of information and has a large storage capacity, and stores the OS (Operating System), various control programs, application programs, etc.

[0050] The control device 15 processes control programs stored in the ROM 153, information processing programs (application programs) loaded into the RAM 152 from storage media such as the HDD 154, etc., using the arithmetic functions of the CPU 151. This processing constitutes a software control unit that includes various functional modules of the control device 15. The combination of this software control unit and the hardware resources installed in the control device 15 constitutes a functional block that realizes the functions of the control device 15. In other words, the CPU 151, RAM 152, ROM 153, and HDD 154 constitute a control unit 150, which acts as a controller that controls the operation of the control device 15 and the printer 1.

[0051] I / F155 is an interface that connects the liquid discharge head 100, carriage 10, rail holding mechanism 21, high-temperature hot air heater 110, low-temperature hot air heater 410, and operation terminal 16 to the common bus 159.

[0052] The control unit 150 operates the liquid discharge head 100, carriage 10, rail holding mechanism 21, high-temperature hot air heater 110, and low-temperature hot air heater 410 via the I / F 155.

[0053] Furthermore, the control unit 150 acquires input from the operation terminal 16 via the I / F 155 and controls the operation of each of the above configurations based on the input setting values ​​and image formation data. It also controls the operation terminal 16 to output information such as the control content.

[0054] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the technical essence, and all technical matters included in the technical concept described in the claims are subject to the present invention. The above embodiments are shown as preferred examples, but those skilled in the art can realize various modifications from the disclosed content. Such modifications are also included in the technical scope described in the claims. [Explanation of Symbols]

[0055] 1: Printer 10: Carriage 15: Control device 16: Operating terminal 20: Strut 21: Rail holding mechanism 21a: First pillar 21b:Second pillar 30: Rail holding part 31a: First rail holding section 31b: Second rail retaining section 40: Guide rail 41: Rod-shaped member 100: Liquid dispensing head 101: Nozzle 110: High-temperature hot air heater 110a: First high-temperature hot air heater 110b: Second high-temperature hot air heater 111: Primary heat source 112:First outlet 150: Control Unit 151: CPU 152: RAM 153 :ROM 154: HDD 155 :I / F 159: Common Bus 410: Low-temperature hot air heater 411:Second heat source 412:Second outlet CB: Vehicle body IA: Image Formation Region [Prior art documents] [Patent Documents]

[0056] [Patent Document 1] Japanese Patent Publication No. 2013-184383

Claims

1. A liquid dispensing head that dispenses liquid onto a medium, A carriage equipped with the aforementioned liquid discharge head, A guide rail supports the carriage so that it can slide in the main scanning direction relative to the medium, A rail holding unit that holds the guide rail so as to be movable in the sub-scanning direction, Support columns for the rail holding section, A first drying unit mounted on the carriage blows air in the direction from which the liquid is discharged, It comprises a second drying unit mounted on the guide rail and blowing air in the direction from which the liquid is discharged, The first drying section is, Arranged on both sides of the liquid discharge head in the main scanning direction, The first heat source and It comprises a first outlet that is tapered toward the medium and sends warm air from the first heat source toward the medium, The second drying section is It is provided on a rod-shaped member located below the guide rail, and is installed at one end of the rod-shaped member in the longitudinal direction, A second heat source equipped with a blower that blows warm air into the internal space of the rod-shaped member, Multiple second outlets are provided at predetermined intervals on the surface of the rod-shaped member facing the medium, and these outlets send warm air from the second heat source toward the medium through the internal space. A liquid dispensing device characterized by comprising the following features.

2. The first drying unit blows air toward the medium when the carriage is inside the image forming region from which the liquid discharge head discharges the liquid. The liquid dispensing device according to claim 1.

3. The second drying section blows air toward the medium across the entire width of the image forming region from which the liquid discharge head discharges the liquid. The liquid dispensing device according to claim 1 or 2.

4. The liquid dispensing device according to any one of claims 1 to 3, wherein the air outlet of the second drying section directed toward the medium is shielded by the carriage.

5. The liquid dispensing apparatus according to any one of claims 1 to 4, wherein the temperature of the air blown from the first drying section is higher than the temperature of the air blown from the second drying section.

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