Ink storage device and inkjet printer comprising the same

Abstract

The present invention relates to an ink storage device and an inkjet printer including the same. The ink storage device is characterized by including, as a storage device for storing ink in order to supply the ink to an inkjet head equipped with a nozzle for discharging the ink, an ink bag, a gas-tight case, a bag fixing portion, and a bag rotating portion, and a gas pressure control device maintains the meniscus state of the ink stored in the ink bag in the inkjet head by controlling the gas pressure inside the gas-tight case separate from the ink. The present invention adopts a configuration that rotates the ink bag while storing the ink in the ink bag located inside the gas-tight case, and thus can maintain the dispersibility of the ink while preventing the ink or ink droplets from flowing into the gas pressure control device in advance.

Description

Technical Field

[0001] This invention relates to an ink storage device for storing ink supplied to the printhead in an inkjet printer, and more particularly to an ink storage device that can maintain the dispersibility of the stored ink while preventing the ink or ink droplets stored in the ink storage device from flowing into the gas pressure control device, and an inkjet printer including the ink storage device. Background Technology

[0002] Currently, devices that dispense liquids for various purposes are widely used in industry. For example, liquids are protruded into desired locations to form patterns in order to draw specific shapes such as circuits; liquids are dispensed at a thin thickness to manufacture thin fibers; or liquids are dispensed onto the surface of an object to be coated.

[0003] Inkjet printing, which sprays liquid ink into droplets onto a media surface based on shape signals, is used not only for printing documents or advertising flyers, but also for solution engineering in the semiconductor or display industry.

[0004] Inkjet printing, which can form complex patterns on a substrate or accurately eject ink to specific locations, is becoming increasingly widely applicable. Small inkjet printers used for printing documents employ a design where ink is stored in an inkjet head that ejects ink droplets. However, large-format document printers or industrial inkjet printers, which require large quantities of ink, use a structure where the ink storage section is separated from the inkjet head.

[0005] Furthermore, in order to accurately eject the required amount of ink during inkjet printing, the ink in the printhead, in its ejection-ready state, needs to maintain a meniscus state, a concave shape relative to the nozzle inlet, achieved through capillary action. To achieve this, the printhead supply reservoir is typically positioned higher than the printhead itself. A gas pressure control device maintains a vacuum within the printhead supply reservoir, creating negative pressure to prevent ink from flowing out of the printhead and thus maintain the meniscus state.

[0006] However, the gas pressure control device still frequently malfunctions due to excessive ink being added to the ink storage device or ink droplets generated inside the ink storage device flowing into the gas pressure control device.

[0007] Figure 4 This is a schematic diagram illustrating the connection between the ink storage device and the gas pressure control device used to store ink in an existing inkjet printer. Figure 5This is a schematic diagram illustrating the state of ink droplets flowing into the gas pressure control device between the ink storage device and the gas pressure control device in an existing inkjet printer.

[0008] As explained above, in order to maintain the meniscus state in the inkjet printer's printhead, the gas pressure control device 20 applies negative pressure to the internal space of the ink reservoir 10. Applying negative pressure to the internal space of the ink reservoir 10 by the gas pressure control device 20 means that the gas pressure control device 20 draws in air that fills the internal space of the ink reservoir 10. Figure 4 The state described above is illustrated in the diagram. Therefore, when too much ink is filled into the ink storage device 10, or when ink droplets generated inside the ink storage device 10 easily flow into the gas pressure control device 20, as shown... Figure 5 As shown, the liquid droplets floating inside the ink storage device 10 will flow into the gas pressure control device 20 through the pressure regulating pipe 21. As described above, when too much ink is filled into the ink storage device 10, or when ink droplets generated inside the ink storage device 10 and floating therein continuously flow into the gas pressure control device 20, problems such as condensation or corrosion due to high humidity may occur inside the gas pressure control device 20. The ink condensation inside and the corrosion of components, as described above, are the main causes of malfunctions in the gas pressure control device.

[0009] To prevent the problems mentioned above, if a filter is used between the ink storage device and the gas pressure control device, it will cause problems with pressure control. Therefore, although the ink storage device is currently constructed by adding a simple protective device, a simple protective device alone cannot fundamentally prevent ink from flowing into the gas pressure control device.

[0010] Furthermore, with the increasing applicability of inkjet printers, there has been a growing trend of using inks containing dispersed particles, such as those used to form electrode patterns, and inks containing dispersed flat panel display materials or organic light-emitting diode (OLED) materials. However, inkjet printing is not feasible due to reduced ink dispersion caused by the weight of the metal particles, flat panel display materials, or OLED materials settling in the ink reservoir of the printhead.

[0011] Although technologies such as installing agitators inside ink storage devices to maintain ink dispersion have been developed, the types of inks applicable to industrial inkjet printing remain relatively limited because there are certain limitations to the method of agitating only the stored ink while maintaining the meniscus state.

[0012] Prior technology documents

[0013] Patent documents

[0014] Republic of Korea Patent No. 10-2139137 Summary of the Invention

[0015] The present invention aims to solve the problems existing in the prior art as described above, and to provide an ink storage device and an inkjet printer that can maintain the dispersibility of ink while preventing ink or ink droplets stored in the ink storage device from flowing into the gas pressure control device.

[0016] To achieve the above-mentioned objectives, the ink storage device according to the present invention, equipped with a rotary ink storage bag, is characterized in that: as a storage device for storing ink to supply ink to an inkjet head equipped with a nozzle for dispensing ink, it comprises: an ink bag made of a flexible material, which stores ink inside and supplies the stored ink to the inkjet head; an airtight housing, in which the ink bag is installed and connected to a gas pressure control device; a bag fixing part installed inside the airtight housing to fix the ink bag at a specific tilt angle; and a bag rotating part that agitates the ink stored in the ink bag by rotating around a specific rotation axis; and the gas pressure control device maintains the ink stored in the ink bag in a curved state in the inkjet head by controlling the gas pressure inside the airtight housing, which is separate from the ink.

[0017] The present invention may further include: two anti-twist connecting parts, located on the rotating shaft of the bag fixing part, one end of which is connected to the ink bag, and the other end of which is respectively connected to a supply flow path for supplying ink to the inkjet head and a recycling flow path for refilling ink discharged from the inkjet head into the ink bag.

[0018] At this time, the additional supply flow path for adding ink to the ink bag can be connected to the recycling flow path or the anti-twist connection connected to the recycling flow path.

[0019] The present invention may further include: a weight measuring unit, which derives the amount of ink stored in the ink bag by measuring the weight of the ink stored in the ink bag.

[0020] The invention may also include a leak detection sensor that detects leaked ink by being mounted on the bottom of the airtight housing.

[0021] An inkjet printer according to another aspect of the present invention includes an ink storage device equipped with a rotary ink reservoir bag, characterized in that it comprises: an inkjet head equipped with nozzles for dispensing ink; an ink storage device for storing ink to supply ink to the inkjet head; and a gas pressure control device connected to the ink storage device to control the internal pressure therein, thereby maintaining the ink stored in the ink storage device in a meniscus state in the inkjet head; wherein the ink storage device includes: an ink bag made of a flexible material, in... The ink bag is internally stored and supplied to the inkjet head; an airtight housing houses the ink bag and is connected to a gas pressure control device; a bag fixing part is installed inside the airtight housing to fix the ink bag at a specific angle; and a bag rotating part agitates the ink stored in the ink bag by rotating around a specific axis; the gas pressure control device controls the gas pressure inside the airtight housing, which is separate from the ink, to maintain the ink stored in the ink bag in a curved state in the inkjet head.

[0022] The present invention may further include: two anti-twist connecting parts, located on the rotating shaft of the bag fixing part, one end of which is connected to the ink bag, and the other end of which is respectively connected to a supply flow path for supplying ink to the inkjet head and a recycling flow path for refilling ink discharged from the inkjet head into the ink bag.

[0023] At this time, the additional supply flow path for adding ink to the ink bag can be connected to the recycling flow path or the anti-twist connection connected to the recycling flow path.

[0024] The present invention may further include: a weight measuring unit, which derives the amount of ink stored in the ink bag by measuring the weight of the ink stored in the ink bag.

[0025] The invention may also include a leak detection sensor that detects leaked ink by being mounted on the bottom of the airtight housing.

[0026] The present invention, configured as described above, can prevent ink or ink droplets from flowing into the gas pressure control device in advance by storing the ink in an ink bag located inside an airtight housing.

[0027] Furthermore, by rotating the ink storage bag and thereby continuously agitating the ink, the uniformity of the ink composition and the uniform dispersion of the particulate matter contained in the ink can be maintained.

[0028] Furthermore, by using a weighing sensor to accurately confirm the amount of ink filled into the ink bag, problems such as adding too much ink or adding the wrong amount of ink can be prevented. Attached Figure Description

[0029] Figure 1 This is a schematic diagram illustrating the configuration of an ink storage device equipped with a rotary ink storage bag and an ink supply system including the ink storage device according to a first embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram illustrating the configuration of an ink storage device equipped with a rotary ink storage bag and an ink supply system including the ink storage device according to a second embodiment of the present invention.

[0031] Figure 3 This is a schematic diagram illustrating the configuration of an ink storage device equipped with a rotary ink storage bag and an ink supply system including the ink storage device according to a third embodiment of the present invention.

[0032] Figure 4 This is a schematic diagram illustrating the connection between the ink storage device and the gas pressure control device used to store ink in an existing inkjet printer.

[0033] Figure 5 This is a schematic diagram illustrating the state of ink droplets flowing into the gas pressure control device between the ink storage device and the gas pressure control device in an existing inkjet printer.

[0034] [Symbol Explanation]

[0035] 100: Inkjet head

[0036] 110: Supply Flow

[0037] 120: Recycling Flow Path

[0038] 130: Circulation pump

[0039] 200: Ink bag

[0040] 210: Airtight outer shell

[0041] 220: Bag fixing part

[0042] 222: Anti-twist connection part

[0043] 230: Bag Rotating Part

[0044] 240: Leak Detection Sensor

[0045] 300: Gas pressure control device

[0046] 310: Pressure regulating pipe

[0047] 400: Buffer Storage Section

[0048] 410: Add supply flow path

[0049] 500: Load cell Detailed Implementation

[0050] The embodiments to which the present invention is applied will now be described in detail with reference to the accompanying drawings.

[0051] However, embodiments of the present invention can be modified into many other forms, and the scope of the present invention is not limited to the embodiments described below. The shapes and sizes of the elements in the drawings may be exaggerated for clarity of illustration, and elements represented by the same numbers in the drawings represent the same elements.

[0052] Furthermore, throughout the specification, when a part is described as being "connected" to other parts, this includes not only "direct connection" but also "electrical connection" where other elements are present between them. Additionally, when a part is described as "comprising" or "equipped" with a certain constituent element, unless otherwise expressly stated to the contrary, this does not mean the exclusion of other constituent elements, but rather that other constituent elements may be included or equipped.

[0053] Furthermore, terms such as "first" and "second" are merely used to distinguish one constituent element from other constituent elements, and the scope of the claims is not limited by these terms. For example, a first constituent element can be named a second constituent element, and similarly, a second constituent element can be named a first constituent element.

[0054] Figure 1 This is a schematic diagram illustrating the configuration of an ink storage device equipped with a rotary ink storage bag and an ink supply system including the ink storage device according to a first embodiment of the present invention.

[0055] The ink storage device equipped with an ink storage bag according to the present invention is suitable for an ink supply system that supplies ink to an inkjet head. The ink supply system will be described first.

[0056] The inkjet head 100 is a portion equipped with nozzles for dispensing ink. The inkjet printer illustrated is an industrial configuration, in which the inkjet head 100 is separated from the ink storage device. Regarding the specific configuration of the inkjet head 100, all technical configurations of inkjet heads used in the past can be applied to the extent that they do not impair the features of the present invention, and in particular, configurations for discharging air bubbles to the outside of the inkjet head 100 to prevent the nozzles in the inkjet head 100 from being clogged by microbubbles.

[0057] The ink storage device is a part for storing ink in order to supply ink to the inkjet head 100. It is connected to one end of the supply flow path 110 for supplying ink to the inkjet head 100 and the recovery flow path 120 for recycling at least a portion of the ink supplied to the inkjet head 100, and is also connected to one end of the pressure regulating pipe 310 for maintaining the state of the meniscus.

[0058] One end of the supply flow path 110 and the other end of the recovery flow path 120 of the ink storage device are connected to the inkjet head 100. The inkjet head 100 receives ink through the supply flow path 110 and performs inkjet printing through the nozzle. At least a portion of the supplied ink is recovered to the ink storage device through the recovery flow path 120, thereby realizing the circulation of ink.

[0059] The gas pressure control device 300 regulates the pressure of the ink reservoir by connecting to the other end of the pressure regulating pipe 310, thereby creating a negative pressure inside the ink reservoir and maintaining the ink inside the inkjet head 100 in a curved state. In the case of normal use where the gas pressure control device is directly connected to the ink reservoir without a bag, because air is continuously drawn in through the pressure regulating pipe 310, ink droplets that diffuse upwards when air bubbles form in the ink reservoir burst may be moved through the pressure regulating pipe 310. Ink droplets flowing into the pressure regulating pipe 310 can induce a malfunction in the gas pressure control device 300.

[0060] A circulation pump 130 is installed to return at least a portion of the ink supplied to the inkjet head 100 to the recovery flow path 120 of the ink reservoir, thereby circulating the ink. In the illustrated embodiment, the circulation pump 130 is shown installed in the recovery flow path 120, but this is not a limitation; it may also be installed in the supply flow path 110. As shown, by continuously circulating the ink between the ink reservoir and the inkjet head 100 using the circulation pump 130, the ink dispersion can be maintained. It is advisable to avoid the operation of the circulation pump 130 affecting the meniscus state.

[0061] The buffer reservoir 400 injects ink into the ink storage device without disrupting the meniscus state, and supplies ink to the ink storage device by connecting the additional supply flow path 410 to the ink storage device. During the injection process from the buffer reservoir 400 into the ink storage device, the meniscus state can be maintained. When adding ink to the buffer reservoir 400, the influence on the meniscus state does not need to be considered, thus simplifying the process of adding ink from the outside. If printing is stopped while replenishing ink consumed during printing, losses will occur; however, when replenishing ink through the buffer reservoir 400, ink can be replenished without stopping the printing process.

[0062] In the ink supply system of the inkjet head described above, if the existing structure of the commonly used ink storage device is directly applied, the ink or ink droplets stored in the ink storage device may flow into the gas pressure control device 300 through the pressure regulating tube 310.

[0063] The ink storage device of the present invention employs a novel structure that prevents ink or ink droplets from flowing into the gas pressure control device 300.

[0064] The ink storage device of this embodiment includes an ink bag 200, an airtight outer shell 210, a bag fixing part 220, and a bag rotating part 230.

[0065] The ink bag 200 is a space for storing ink. It is made of a flexible material and the pressure of the ink stored inside the ink bag 200 can be adjusted according to the external air pressure. As for the material of the ink bag 200, all flexible materials can be used without special restrictions. For example, polypropylene (PP) can be used when using solutions where chemical resistance is not a concern, while polytetrafluoroethylene (PTFE) can be used when using solutions where chemical resistance is a concern. The shape of the ink bag 200 is not particularly limited; general bag shapes for storing liquid substances can be used, especially wider bag shapes.

[0066] Furthermore, the supply flow path 110 and the recovery flow path 120 described above are connected to the ink bag 200. As mentioned above, from the viewpoint that the supply flow path 110 and the recovery flow path 120 are connected to the ink bag 200, it may be considered that the overall function and structure correspond to that of conventional ink storage devices. However, the difference between the present invention and conventional ink storage devices is that the ink bag 200 is not directly connected to the gas pressure control device 300. The gas pressure control device 300 of the present invention adopts a structure that is only connected to the airtight housing 210 and completely separated from the ink bag 200, which will be explained in detail later.

[0067] As a result, because the ink is stored inside a separate ink bag 200 that is not connected to the gas pressure control device 300 in this invention, even if an excessive amount of ink is injected into the ink bag 200, the problem of ink flowing into the gas pressure control device 300 can be prevented. Furthermore, because the ink bag 200 is a structure completely separated from the gas pressure control device 300, droplets generated in the ink exist only inside the ink bag 200 and cannot flow into the gas pressure control device 300, thereby effectively preventing the problem of ink or ink droplets flowing into the gas pressure control device 300 in advance. In addition, compared with the existing structure where the ink is stored in a space where the internal pressure is reduced by the gas pressure control device 300, the evaporation of the stored ink can be suppressed because the ink is stored in the ink bag 200 that is completely separated from the gas pressure control device 300.

[0068] The airtight outer shell 210 is an airtight shell in which the ink bag 200 is disposed and connected to the gas pressure control device 300 via a pressure regulating pipe 310, so as to apply pressure to the ink stored in the ink bag 200 by regulating the gas pressure. The gas pressure control device 300 can control the internal pressure of the airtight outer shell 210. Since changes in the gas pressure inside the airtight outer shell 210 will affect the flexible ink bag 200 installed inside the airtight outer shell 210, when a negative pressure is applied to the inside of the airtight outer shell 210, the gas pressure around the flexible ink bag 200 decreases, and the negative pressure is also applied to the inside of the ink bag 200. Conversely, when a positive pressure is applied to the inside of the airtight outer shell 210, the gas pressure around the flexible ink bag 200 increases, and the positive pressure is also applied to the inside of the ink bag 200.

[0069] Because existing ink storage devices store ink directly inside a housing connected to the pressure regulating pipe 310 of the gas pressure control device 300, excessive ink injection can cause ink to flow into the gas pressure control device 300. Furthermore, ink droplets generated by the bursting of air bubbles within the stored ink can also flow into the gas pressure control device 300. In this embodiment, because the gas pressure control device 300 is only connected to the airtight housing 210, and a separate ink bag 200 for storing ink is formed inside the airtight housing 210, the internal structure of the flexible ink bag 200 can be indirectly adjusted by regulating the gas pressure inside the airtight housing 210. This maintains the curved surface state and prevents ink or ink droplets from flowing into the gas pressure control device 300.

[0070] The bag fixing part 220 is a configuration for fixing the ink bag 200, and is a configuration introduced to enable the rotation of the flexible material ink bag 200. This invention employs a configuration that rotates the stored ink to maintain ink dispersion; however, because the ink bag 200 storing the ink is made of a flexible material, it is difficult to directly rotate the ink bag 200 itself. To solve the problem described above, a structure is adopted in which the ink bag 200 is mounted and fixed to the bag fixing part 220, and the bag fixing part 220 is rotated around a specific rotation axis by means of the bag rotating part 230, causing the ink bag 200 fixed in the bag fixing part 220 to rotate accordingly.

[0071] Furthermore, as mentioned above, it is preferable that the ink bag 200 be made in a flat, bag-like shape. When the ink bag 200 is installed upright, there is a problem that the ink is only present in the lower part of the overall volume of the ink bag 200, thus failing to fully utilize its shape. Conversely, when it is installed flat, it becomes difficult to discharge ink when the amount of ink is small. Therefore, by configuring the ink bag 200 at a specific angle, compared to an upright installation, the ink can be evenly distributed throughout the ink bag 200, and compared to a flat installation, the ink stored in the ink bag 200 can be used more easily. To install the ink bag 200 at an angle, the bag fixing part 220 that secures the ink bag 200 is installed at a specific angle, and the rotating shaft for driving the bag fixing part 220 to rotate is formed at the same angle.

[0072] The bag fixing part 230 is connected to the bag fixing part 220 via a specific rotating shaft. By rotating the bag fixing part 220 around the rotating shaft, the ink bag 200 fixed in the bag fixing part 220 is driven to rotate, thereby achieving the effect of stirring the ink stored in the ink bag 200.

[0073] Furthermore, as described above, the ink bag 200 is connected to a supply flow path 110 for supplying ink to the inkjet head 100 and a recovery flow path 120 for circulating and returning at least a portion of the ink supplied to the inkjet head 100. However, since the ink bag 200 is rotated by rotating the bag fixing part 220, connecting the supply flow path 110 and the recovery flow path 120 to the ink bag 200 in a conventional manner can cause the supply flow path 110 and the recovery flow path 120 to twist when the bag fixing part 220 rotates. To solve the problem described above, it is preferable that the supply flow path 110 and the recovery flow path 120 are connected to the ink bag 200 via an anti-twist connection 222, and the anti-twist connection 222 is located on the rotation axis of the bag fixing part 220. As described above, in order to ensure that the ink is evenly distributed throughout all parts of the ink bag 200 and to facilitate the discharge of ink stored in the ink bag 200, the bag fixing part 220 on which the ink bag 200 is mounted is configured at a specific angle. Therefore, the rotation axis of the bag fixing part 220 is also tilted at a specific angle. At this time, among the two anti-twist connecting parts 222 located on the rotation axis of the bag fixing part 200, only by connecting the supply flow path 110 to the anti-twist connecting part located on the lower side and the return flow path 120 to the anti-twist connecting part located on the upper side can the ink be smoothly supplied to the inkjet head 100 regardless of the amount of ink stored in the ink bag 200.

[0074] Furthermore, an additional supply flow path 410 is required in the ink bag 200 for adding ink without disrupting the meniscus. However, due to the rotating structure of the ink bag 200, the additional supply flow path 410 cannot be connected to any location other than the supply flow path 110 connected to the two anti-twist connectors 222 and the recovery flow path 120. Therefore, the additional supply flow path 410 is configured to be connected to the anti-twist connector 222 connected to the recovery flow path 120 or simultaneously connected to the recovery flow path 120.

[0075] According to this embodiment, an inkjet printer including an ink storage device equipped with a rotary ink storage bag can prevent ink or ink droplets from flowing into the gas pressure control device used to apply negative pressure by separating the space where the gas pressure control device controls the pressure and the space where the ink is stored.

[0076] Furthermore, the storage and usage efficiency of ink can be improved by installing the bag-shaped ink bag at a specific angle, and the ink dispersion can be maintained by rotating the ink bag.

[0077] Figure 2This is a schematic diagram illustrating the configuration of an ink storage device equipped with a rotary ink storage bag and an ink supply system including the ink storage device according to a second embodiment of the present invention.

[0078] The ink storage device equipped with an ink storage bag according to the present invention is suitable for an ink supply system that supplies ink to an inkjet head. The ink supply system will be described first.

[0079] The inkjet head 100 is a portion equipped with nozzles for dispensing ink. The inkjet printer illustrated is an industrial configuration, in which the inkjet head 100 is separated from the ink storage device. Regarding the specific configuration of the inkjet head 100, all technical configurations of inkjet heads used in the past can be applied to the extent that they do not impair the features of the present invention, and in particular, configurations for discharging air bubbles to the outside of the inkjet head 100 to prevent the nozzles in the inkjet head 100 from being clogged by microbubbles.

[0080] The ink storage device is a part for storing ink in order to supply ink to the inkjet head 100. It is connected to one end of the supply flow path 110 for supplying ink to the inkjet head 100 and the recovery flow path 120 for recycling at least a portion of the ink supplied to the inkjet head 100, and is also connected to one end of the pressure regulating pipe 310 for maintaining the state of the meniscus.

[0081] One end of the supply flow path 110 and the other end of the recovery flow path 120 of the ink storage device are connected to the inkjet head 100. The inkjet head 100 receives ink through the supply flow path 110 and performs inkjet printing through the nozzle. At least a portion of the supplied ink is recovered to the ink storage device through the recovery flow path 120, thereby realizing the circulation of ink.

[0082] The gas pressure control device 300 regulates the pressure of the ink reservoir by connecting to the other end of the pressure regulating pipe 310, thereby creating a negative pressure inside the ink reservoir and maintaining the ink inside the inkjet head 100 in a curved state. In the case of normal use where the gas pressure control device is directly connected to the ink reservoir without a bag, because air is continuously drawn in through the pressure regulating pipe 310, ink droplets that diffuse upwards when air bubbles form in the ink reservoir burst may be moved through the pressure regulating pipe 310. Ink droplets flowing into the pressure regulating pipe 310 can induce a malfunction in the gas pressure control device 300.

[0083] A circulation pump 130 is installed to return at least a portion of the ink supplied to the inkjet head 100 to the recovery flow path 120 of the ink reservoir, thereby circulating the ink. In the illustrated embodiment, the circulation pump 130 is shown installed in the recovery flow path 120, but this is not a limitation; it may also be installed in the supply flow path 110. As shown, by continuously circulating the ink between the ink reservoir and the inkjet head 100 using the circulation pump 130, the ink dispersion can be maintained. It is advisable to avoid the operation of the circulation pump 130 affecting the meniscus state.

[0084] The buffer reservoir 400 injects ink into the ink storage device without disrupting the meniscus state, and supplies ink to the ink storage device by connecting the additional supply flow path 410 to the ink storage device. During the injection process from the buffer reservoir 400 into the ink storage device, the meniscus state can be maintained. When adding ink to the buffer reservoir 400, the influence on the meniscus state does not need to be considered, thus simplifying the process of adding ink from the outside. If printing is stopped while replenishing ink consumed during printing, losses will occur; however, when replenishing ink through the buffer reservoir 400, ink can be replenished without stopping the printing process.

[0085] In the ink supply system of the inkjet head described above, if the existing structure of the commonly used ink storage device is directly applied, the ink or ink droplets stored in the ink storage device may flow into the gas pressure control device 300 through the pressure regulating tube 310.

[0086] The ink storage device of the present invention employs a novel structure that prevents ink or ink droplets from flowing into the gas pressure control device 300.

[0087] The ink storage device of this embodiment includes an ink bag 200, an airtight outer shell 210, a bag fixing part 220, a bag rotating part 230, and a weighing sensor 500.

[0088] The ink bag 200 is a space for storing ink. It is made of a flexible material and the pressure of the ink stored inside the ink bag 200 can be adjusted according to the external air pressure. As for the material of the ink bag 200, all flexible materials can be used without special restrictions. For example, polypropylene (PP) can be used when using solutions where chemical resistance is not a concern, while polytetrafluoroethylene (PTFE) can be used when using solutions where chemical resistance is a concern. The shape of the ink bag 200 is not particularly limited; general bag shapes for storing liquid substances can be used, especially wider bag shapes.

[0089] Furthermore, the supply flow path 110 and the recovery flow path 120 described above are connected to the ink bag 200. As mentioned above, from the viewpoint that the supply flow path 110 and the recovery flow path 120 are connected to the ink bag 200, it may be considered that the overall function and structure correspond to that of conventional ink storage devices. However, the difference between the present invention and conventional ink storage devices is that the ink bag 200 is not directly connected to the gas pressure control device 300. The gas pressure control device 300 of the present invention adopts a structure that is only connected to the airtight housing 210 and completely separated from the ink bag 200, which will be explained in detail later.

[0090] As a result, because the ink is stored inside a separate ink bag 200 that is not connected to the gas pressure control device 300 in this invention, even if an excessive amount of ink is injected into the ink bag 200, the problem of ink flowing into the gas pressure control device 300 can be prevented. Furthermore, because the ink bag 200 is a structure completely separated from the gas pressure control device 300, droplets generated in the ink exist only inside the ink bag 200 and cannot flow into the gas pressure control device 300, thereby effectively preventing the problem of ink or ink droplets flowing into the gas pressure control device 300 in advance. In addition, compared with the existing structure where the ink is stored in a space where the internal pressure is reduced by the gas pressure control device 300, the evaporation of the stored ink can be suppressed because the ink is stored in the ink bag 200 that is completely separated from the gas pressure control device 300.

[0091] The airtight outer shell 210 is an airtight shell in which the ink bag 200 is disposed and connected to the gas pressure control device 300 via a pressure regulating pipe 310, so as to apply pressure to the ink stored in the ink bag 200 by regulating the gas pressure. The gas pressure control device 300 can control the internal pressure of the airtight outer shell 210. Since changes in the gas pressure inside the airtight outer shell 210 will affect the flexible ink bag 200 installed inside the airtight outer shell 210, when a negative pressure is applied to the inside of the airtight outer shell 210, the gas pressure around the flexible ink bag 200 decreases, and the negative pressure is also applied to the inside of the ink bag 200. Conversely, when a positive pressure is applied to the inside of the airtight outer shell 210, the gas pressure around the flexible ink bag 200 increases, and the positive pressure is also applied to the inside of the ink bag 200.

[0092] Because existing ink storage devices store ink directly inside a housing connected to the pressure regulating pipe 310 of the gas pressure control device 300, excessive ink injection can cause ink to flow into the gas pressure control device 300. Furthermore, ink droplets generated by the bursting of air bubbles within the stored ink can also flow into the gas pressure control device 300. In this embodiment, because the gas pressure control device 300 is only connected to the airtight housing 210, and a separate ink bag 200 for storing ink is formed inside the airtight housing 210, the internal structure of the flexible ink bag 200 can be indirectly adjusted by regulating the gas pressure inside the airtight housing 210. This maintains the curved surface state and prevents ink or ink droplets from flowing into the gas pressure control device 300.

[0093] The bag fixing part 220 is a configuration for fixing the ink bag 200, and is a configuration introduced to enable the rotation of the flexible material ink bag 200. This invention employs a configuration that rotates the stored ink to maintain ink dispersion; however, because the ink bag 200 storing the ink is made of a flexible material, it is difficult to directly rotate the ink bag 200 itself. To solve the problem described above, a structure is adopted in which the ink bag 200 is mounted and fixed to the bag fixing part 220, and the bag fixing part 220 is rotated around a specific rotation axis by means of the bag rotating part 230, causing the ink bag 200 fixed in the bag fixing part 220 to rotate accordingly.

[0094] Furthermore, as mentioned above, it is preferable that the ink bag 200 be made in a flat, bag-like shape. When the ink bag 200 is installed upright, there is a problem that the ink is only present in the lower part of the overall volume of the ink bag 200, thus failing to fully utilize its shape. Conversely, when it is installed flat, it becomes difficult to discharge ink when the amount of ink is small. Therefore, by configuring the ink bag 200 at a specific angle, compared to an upright installation, the ink can be evenly distributed throughout the ink bag 200, and compared to a flat installation, the ink stored in the ink bag 200 can be used more easily. To install the ink bag 200 at an angle, the bag fixing part 220 that secures the ink bag 200 is installed at a specific angle, and the rotating shaft for driving the bag fixing part 220 to rotate is formed at the same angle.

[0095] The bag fixing part 230 is connected to the bag fixing part 220 via a specific rotating shaft. By rotating the bag fixing part 220 around the rotating shaft, the ink bag 200 fixed in the bag fixing part 220 is driven to rotate, thereby achieving the effect of stirring the ink stored in the ink bag 200.

[0096] Furthermore, as described above, the ink bag 200 is connected to a supply flow path 110 for supplying ink to the inkjet head 100 and a recovery flow path 120 for circulating and returning at least a portion of the ink supplied to the inkjet head 100. However, since the ink bag 200 is rotated by rotating the bag fixing part 220, connecting the supply flow path 110 and the recovery flow path 120 to the ink bag 200 in a conventional manner can cause the supply flow path 110 and the recovery flow path 120 to twist when the bag fixing part 220 rotates. To solve the problem described above, it is preferable that the supply flow path 110 and the recovery flow path 120 are connected to the ink bag 200 via an anti-twist connection 222, and the anti-twist connection 222 is located on the rotation axis of the bag fixing part 220. As described above, in order to ensure that the ink is evenly distributed throughout all parts of the ink bag 200 and to facilitate the discharge of ink stored in the ink bag 200, the bag fixing part 220 on which the ink bag 200 is mounted is configured at a specific angle. Therefore, the rotation axis of the bag fixing part 220 is also tilted at a specific angle. At this time, among the two anti-twist connecting parts 222 located on the rotation axis of the bag fixing part 200, only by connecting the supply flow path 110 to the anti-twist connecting part located on the lower side and the return flow path 120 to the anti-twist connecting part located on the upper side can the ink be smoothly supplied to the inkjet head 100 regardless of the amount of ink stored in the ink bag 200.

[0097] Furthermore, an additional supply flow path 410 is required in the ink bag 200 for adding ink without disrupting the meniscus. However, due to the rotating structure of the ink bag 200, the additional supply flow path 410 cannot be connected to any location other than the supply flow path 110 connected to the two anti-twist connectors 222 and the recovery flow path 120. Therefore, the additional supply flow path 410 is configured to be connected to the anti-twist connector 222 connected to the recovery flow path 120 or simultaneously connected to the recovery flow path 120.

[0098] The weighing sensor 500 is a component used to confirm the amount of ink stored in the ink bag 200 by measuring the weight of the airtight housing 210. Because the ink bag 200, installed inside the airtight housing 210 in this invention, rotates together with the bag fixing part 220, it is not easy to easily confirm the amount of ink stored in the ink bag 200. Therefore, in this embodiment, the amount of ink stored in the ink bag 200 is confirmed by using a weighing sensor 500 that measures the weight of the airtight housing 210 containing the ink bag 200. Although components such as the bag fixing part 220 and the bag rotating part 230 are installed inside the airtight housing 210 in addition to the ink bag 200, their weight is constant, so only the amount of ink stored in the ink bag 200 causes a change in the overall weight of the airtight housing 210. Therefore, the amount of ink stored in the ink bag 200 can be deduced by the weighing sensor 500 that measures the weight of the airtight housing 210. At this time, the composition of the amount of ink stored in ink bag 200 is not limited to the illustrated embodiment, which is deduced by measuring the weight of the ink stored in ink bag. It is also possible to install a configuration for measuring weight inside the airtight housing 210.

[0099] According to this embodiment, an inkjet printer including an ink storage device equipped with a rotary ink storage bag can prevent ink or ink droplets from flowing into the gas pressure control device used to apply negative pressure by separating the space where the gas pressure control device controls the pressure and the space where the ink is stored.

[0100] Furthermore, the storage and usage efficiency of ink can be improved by installing the bag-shaped ink bag at a specific angle, and the ink dispersion can be maintained by rotating the ink bag.

[0101] Furthermore, the amount of ink stored in the ink bag can be accurately confirmed by measuring its weight.

[0102] Figure 3 This is a schematic diagram illustrating the configuration of an ink storage device equipped with a rotary ink storage bag and an ink supply system including the ink storage device according to a third embodiment of the present invention.

[0103] The ink storage device equipped with an ink storage bag according to the present invention is suitable for an ink supply system that supplies ink to an inkjet head. The ink supply system will be described first.

[0104] The inkjet head 100 is a portion equipped with nozzles for dispensing ink. The inkjet printer illustrated is an industrial configuration, in which the inkjet head 100 is separated from the ink storage device. Regarding the specific configuration of the inkjet head 100, all technical configurations of inkjet heads used in the past can be applied to the extent that they do not impair the features of the present invention, and in particular, configurations for discharging air bubbles to the outside of the inkjet head 100 to prevent the nozzles in the inkjet head 100 from being clogged by microbubbles.

[0105] The ink storage device is a part for storing ink in order to supply ink to the inkjet head 100. It is connected to one end of the supply flow path 110 for supplying ink to the inkjet head 100 and the recovery flow path 120 for recycling at least a portion of the ink supplied to the inkjet head 100, and is also connected to one end of the pressure regulating pipe 310 for maintaining the state of the meniscus.

[0106] One end of the supply flow path 110 and the other end of the recovery flow path 120 of the ink storage device are connected to the inkjet head 100. The inkjet head 100 receives ink through the supply flow path 110 and performs inkjet printing through the nozzle. At least a portion of the supplied ink is recovered to the ink storage device through the recovery flow path 120, thereby realizing the circulation of ink.

[0107] The gas pressure control device 300 regulates the pressure of the ink reservoir by connecting to the other end of the pressure regulating pipe 310, thereby creating a negative pressure inside the ink reservoir and maintaining the ink inside the inkjet head 100 in a curved state. In the case of normal use where the gas pressure control device is directly connected to the ink reservoir without using an ink reservoir bag, because air is continuously drawn in through the pressure regulating pipe 310, ink droplets that diffuse upwards when air bubbles formed in the ink reservoir burst may move through the pressure regulating pipe 310. Ink droplets flowing into the pressure regulating pipe 310 can induce a malfunction in the gas pressure control device 300.

[0108] A circulation pump 130 is installed to return at least a portion of the ink supplied to the inkjet head 100 to the recovery flow path 120 of the ink reservoir, thereby circulating the ink. In the illustrated embodiment, the circulation pump 130 is shown installed in the recovery flow path 120, but this is not a limitation; it may also be installed in the supply flow path 110. As shown, by continuously circulating the ink between the ink reservoir and the inkjet head 100 using the circulation pump 130, the ink dispersion can be maintained. It is advisable to avoid the operation of the circulation pump 130 affecting the meniscus state.

[0109] The buffer reservoir 400 injects ink into the ink storage device without disrupting the meniscus state, and supplies ink to the ink storage device by connecting the additional supply flow path 410 to the ink storage device. During the injection process from the buffer reservoir 400 into the ink storage device, the meniscus state can be maintained. When adding ink to the buffer reservoir 400, the influence on the meniscus state does not need to be considered, thus simplifying the process of adding ink from the outside. If printing is stopped while replenishing ink consumed during printing, losses will occur; however, when replenishing ink through the buffer reservoir 400, ink can be replenished without stopping the printing process.

[0110] In the ink supply system of the inkjet head described above, if the existing structure of the commonly used ink storage device is directly applied, the ink or ink droplets stored in the ink storage device may flow into the gas pressure control device 300 through the pressure regulating tube 310.

[0111] The ink storage device of the present invention employs a novel structure that prevents ink or ink droplets from flowing into the gas pressure control device 300.

[0112] The ink storage device of this embodiment includes an ink bag 200, an airtight outer shell 210, a bag fixing part 220, a bag rotating part 230, and a leakage detection sensor 240.

[0113] The ink bag 200 is a space for storing ink. It is made of a flexible material and the pressure of the ink stored inside the ink bag 200 can be adjusted according to the external air pressure. As for the material of the ink bag 200, all flexible materials can be used without special restrictions. For example, polypropylene (PP) can be used when using solutions where chemical resistance is not a concern, while polytetrafluoroethylene (PTFE) can be used when using solutions where chemical resistance is a concern. The shape of the ink bag 200 is not particularly limited; general bag shapes for storing liquid substances can be used, especially wider bag shapes.

[0114] Furthermore, the supply flow path 110 and the recovery flow path 120 described above are connected to the ink bag 200. As mentioned above, from the viewpoint that the supply flow path 110 and the recovery flow path 120 are connected to the ink bag 200, it may be considered that the overall function and structure correspond to that of conventional ink storage devices. However, the difference between the present invention and conventional ink storage devices is that the ink bag 200 is not directly connected to the gas pressure control device 300. The gas pressure control device 300 of the present invention adopts a structure that is only connected to the airtight housing 210 and completely separated from the ink bag 200, which will be explained in detail later.

[0115] As a result, because the ink is stored inside a separate ink bag 200 that is not connected to the gas pressure control device 300 in this invention, even if an excessive amount of ink is injected into the ink bag 200, the problem of ink flowing into the gas pressure control device 300 can be prevented. Furthermore, because the ink bag 200 is a structure completely separated from the gas pressure control device 300, droplets generated in the ink exist only inside the ink bag 200 and cannot flow into the gas pressure control device 300, thereby effectively preventing the problem of ink or ink droplets flowing into the gas pressure control device 300 in advance. In addition, compared with the existing structure where the ink is stored in a space where the internal pressure is reduced by the gas pressure control device 300, the evaporation of the stored ink can be suppressed because the ink is stored in the ink bag 200 that is completely separated from the gas pressure control device 300.

[0116] The airtight outer shell 210 is an airtight shell in which the ink bag 200 is disposed and connected to the gas pressure control device 300 via a pressure regulating pipe 310, so as to apply pressure to the ink stored in the ink bag 200 by regulating the gas pressure. The gas pressure control device 300 can control the internal pressure of the airtight outer shell 210. Since changes in the gas pressure inside the airtight outer shell 210 will affect the flexible ink bag 200 installed inside the airtight outer shell 210, when a negative pressure is applied to the inside of the airtight outer shell 210, the gas pressure around the flexible ink bag 200 decreases, and the negative pressure is also applied to the inside of the ink bag 200. Conversely, when a positive pressure is applied to the inside of the airtight outer shell 210, the gas pressure around the flexible ink bag 200 increases, and the positive pressure is also applied to the inside of the ink bag 200.

[0117] Because existing ink storage devices store ink directly inside a housing connected to the pressure regulating pipe 310 of the gas pressure control device 300, excessive ink injection can cause ink to flow into the gas pressure control device 300. Furthermore, ink droplets generated by the bursting of air bubbles within the stored ink can also flow into the gas pressure control device 300. In this embodiment, because the gas pressure control device 300 is only connected to the airtight housing 210, and a separate ink bag 200 for storing ink is formed inside the airtight housing 210, the internal structure of the flexible ink bag 200 can be indirectly adjusted by regulating the gas pressure inside the airtight housing 210. This maintains the curved surface state and prevents ink or ink droplets from flowing into the gas pressure control device 300.

[0118] The bag fixing part 220 is a configuration for fixing the ink bag 200, and is a configuration introduced to enable the rotation of the flexible material ink bag 200. This invention employs a configuration that rotates the stored ink to maintain ink dispersion; however, because the ink bag 200 storing the ink is made of a flexible material, it is difficult to directly rotate the ink bag 200 itself. To solve the problem described above, a structure is adopted in which the ink bag 200 is mounted and fixed to the bag fixing part 220, and the bag fixing part 220 is rotated around a specific rotation axis by means of the bag rotating part 230, causing the ink bag 200 fixed in the bag fixing part 220 to rotate accordingly.

[0119] Furthermore, as mentioned above, it is preferable that the ink bag 200 be made in a flat, bag-like shape. When the ink bag 200 is installed upright, there is a problem that the ink is only present in the lower part of the overall volume of the ink bag 200, thus failing to fully utilize its shape. Conversely, when it is installed flat, it becomes difficult to discharge ink when the amount of ink is small. Therefore, by configuring the ink bag 200 at a specific angle, compared to an upright installation, the ink can be evenly distributed throughout the ink bag 200, and compared to a flat installation, the ink stored in the ink bag 200 can be used more easily. To install the ink bag 200 at an angle, the bag fixing part 220 that secures the ink bag 200 is installed at a specific angle, and the rotating shaft for driving the bag fixing part 220 to rotate is formed at the same angle.

[0120] The bag fixing part 230 is connected to the bag fixing part 220 via a specific rotating shaft. By rotating the bag fixing part 220 around the rotating shaft, the ink bag 200 fixed in the bag fixing part 220 is driven to rotate, thereby achieving the effect of stirring the ink stored in the ink bag 200.

[0121] Furthermore, as described above, the ink bag 200 is connected to a supply flow path 110 for supplying ink to the inkjet head 100 and a recovery flow path 120 for circulating and returning at least a portion of the ink supplied to the inkjet head 100. However, since the ink bag 200 is rotated by rotating the bag fixing part 220, connecting the supply flow path 110 and the recovery flow path 120 to the ink bag 200 in a conventional manner can cause the supply flow path 110 and the recovery flow path 120 to twist when the bag fixing part 220 rotates. To solve the problem described above, it is preferable that the supply flow path 110 and the recovery flow path 120 are connected to the ink bag 200 via an anti-twist connection 222, and the anti-twist connection 222 is located on the rotation axis of the bag fixing part 220. As described above, in order to ensure that the ink is evenly distributed throughout all parts of the ink bag 200 and to facilitate the discharge of ink stored in the ink bag 200, the bag fixing part 220 on which the ink bag 200 is mounted is configured at a specific angle. Therefore, the rotation axis of the bag fixing part 220 is also tilted at a specific angle. At this time, among the two anti-twist connecting parts 222 located on the rotation axis of the bag fixing part 200, only by connecting the supply flow path 110 to the anti-twist connecting part located on the lower side and the return flow path 120 to the anti-twist connecting part located on the upper side can the ink be smoothly supplied to the inkjet head 100 regardless of the amount of ink stored in the ink bag 200.

[0122] Furthermore, an additional supply flow path 410 is required in the ink bag 200 for adding ink without disrupting the meniscus. However, due to the rotating structure of the ink bag 200, the additional supply flow path 410 cannot be connected to any location other than the supply flow path 110 connected to the two anti-twist connectors 222 and the recovery flow path 120. Therefore, the additional supply flow path 410 is configured to be connected to the anti-twist connector 222 connected to the recovery flow path 120 or simultaneously connected to the recovery flow path 120.

[0123] Leakage detection sensor 240 can detect whether ink is leaking from ink bag 200 by being installed in airtight housing 210. Ink may leak from ink bag 200 if it is damaged or if too much ink is added. As described above, leaked ink may evaporate and flow into gas pressure control device 300, potentially causing malfunction. Therefore, it is crucial to quickly detect ink leaking from ink bag 200. Various sensors for detecting liquids can be used as leakage detection sensor 240, without any particular limitation. By forming an inclined surface on the bottom of airtight housing 210 and installing leakage detection sensor 240 at its lowest point, even leaks of only a small amount of ink can be detected.

[0124] According to this embodiment, an inkjet printer including an ink storage device equipped with a rotary ink storage bag can prevent ink or ink droplets from flowing into the gas pressure control device used to apply negative pressure by separating the space where the gas pressure control device controls the pressure and the space where the ink is stored.

[0125] Furthermore, the storage and usage efficiency of ink can be improved by installing the bag-shaped ink bag at a specific angle, and the ink dispersion can be maintained by rotating the ink bag.

[0126] Furthermore, the problem of ink leaking from the ink bag flowing into the gas pressure control device used to apply negative pressure can be prevented by including a sensor for detecting ink leaking from the ink bag into the airtight housing.

[0127] The present invention has been described above with reference to preferred embodiments. However, these embodiments are merely illustrative examples of the technical concept of the invention. Those skilled in the art should understand that various modifications can be made to the invention without departing from its technical concept. Therefore, the scope of protection of the present invention should be interpreted through the matters recorded in the claims rather than the specific embodiments, and should be interpreted as including all technical concepts within the equivalent scope within the scope of the claims of the present invention.

Claims

1. An ink storage device equipped with a rotary ink storage bag, characterized in that: A storage device for storing ink in order to supply ink to an inkjet head equipped with nozzles for dispensing ink includes: Ink bags, made of flexible material, store ink inside and supply the stored ink to the inkjet head; An airtight outer shell, inside which the ink bag is installed and connected to a gas pressure control device; The bag fixing part is installed inside the airtight shell to fix the ink bag at a specific angle; The bag rotating section agitates the ink stored in the ink bag by rotating around a specific rotating axis; and, A leak detection sensor is installed at the bottom inside the airtight housing to detect leaking ink. The gas pressure control device maintains the ink stored in the ink bag in a curved state in the inkjet head by controlling the gas pressure inside the airtight housing that is separate from the ink, wherein the gas pressure control device applies internal negative pressure.

2. The ink storage device equipped with a rotary ink storage bag according to claim 1, characterized in that, Also includes: Two anti-twist connecting parts are located on the rotating shaft of the bag fixing part, one end of which is connected to the ink bag, and the other end is respectively connected to the supply flow path for supplying ink to the ink head and the recycling flow path for re-injecting ink discharged from the ink head into the ink bag.

3. The ink storage device equipped with a rotary ink storage bag according to claim 2, characterized in that: An additional supply flow path for adding ink to the ink bag is connected to the recycling flow path or an anti-twist connection connected to the recycling flow path.

4. The ink storage device equipped with a rotary ink storage bag according to claim 1, characterized in that, Also includes: The weight measuring unit derives the amount of ink stored in the ink bag by measuring the weight of the ink stored in the ink bag.

5. An inkjet printer comprising an ink storage device equipped with a rotary ink storage bag, characterized in that, include: The inkjet head is equipped with nozzles for dispensing ink. An ink storage device for storing ink in order to supply ink to the inkjet head; as well as, A gas pressure control device controls the internal pressure of the ink storage device by connecting to it, thereby maintaining the ink stored in the ink storage device in a meniscus state in the inkjet head. The ink storage device includes: Ink bags, made of flexible material, store ink inside and supply the stored ink to the inkjet head; An airtight outer shell, inside which the ink bag is installed and connected to a gas pressure control device; The bag fixing part is installed inside the airtight shell to fix the ink bag at a specific angle; The bag rotating section agitates the ink stored in the ink bag by rotating around a specific rotating axis; and, A leak detection sensor is installed at the bottom inside the airtight housing to detect leaking ink. The gas pressure control device maintains the ink stored in the ink bag in a curved state in the inkjet head by controlling the gas pressure inside the airtight housing that is separate from the ink, wherein the gas pressure control device applies internal negative pressure.

6. The inkjet printer according to claim 5, comprising an ink storage device equipped with a rotary ink storage bag, characterized in that, Also includes: Two anti-twist connecting parts are located on the rotating shaft of the bag fixing part, one end of which is connected to the ink bag, and the other end is respectively connected to the supply flow path for supplying ink to the ink head and the recycling flow path for re-injecting ink discharged from the ink head into the ink bag.

7. The inkjet printer according to claim 6, comprising an ink storage device equipped with a rotary ink storage bag, characterized in that: An additional supply flow path for adding ink to the ink bag is connected to the recycling flow path or an anti-twist connection connected to the recycling flow path.

8. The inkjet printer according to claim 5, comprising an ink storage device equipped with a rotary ink storage bag, characterized in that, Also includes: The weight measuring unit derives the amount of ink stored in the ink bag by measuring the weight of the ink stored in the ink bag.

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