Inkjet head ink supply system and inkjet printer comprising the same

Abstract

The present invention relates to an ink jet head ink supply system equipped with an emergency recovery function and an ink jet printer including the ink supply system. The ink jet head ink supply system is characterized by including: an ink jet head; an ink storage device; a supply flow path; a recovery flow path; a flow path blocker; a flow path switcher; a drain pipe; a discharge ink storage portion; and, a drain portion.

Description

Technical Field

[0001] This invention relates to a system for supplying ink to an inkjet head in an inkjet printer, and more particularly to an inkjet head ink supply system capable of emergency recovery of ink from the inkjet head when the inkjet printer stops, and an inkjet printer including said ink supply system. 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 dispensing preparation 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, and a vacuum is maintained within the reservoir using a gas pressure regulating device. This creates negative pressure within the printhead supply reservoir, preventing ink from flowing out of the printhead and thus maintaining the meniscus state.

[0006] As described above, industrial inkjet printers perform printing by continuously supplying ink to the printhead and dispensing the required amount of ink through the nozzle's ejection action and a gas pressure regulating device. However, if an emergency such as a power outage causes the nozzles or gas pressure regulating device of the printhead in the inkjet printer to lose control, ink can leak downwards through the printhead. To prevent ink leakage through the printhead as described above, a technique is used to stop supplying ink to the printhead in an emergency; however, the ink already supplied to the printhead will still leak out completely. As mentioned above, when ink leaks from the printhead, not only can the object below it be no longer usable, but printing operations also suffer from a significant decrease in productivity because the surrounding contamination must be addressed before printing can resume.

[0007] Prior technology documents

[0008] Patent documents

[0009] (Patent Document 1) Japanese Patent Registration No. 4382013 Summary of the Invention

[0010] The present invention aims to solve the problems existing in the prior art as described above and to provide an inkjet head ink supply system and an inkjet printer that can prevent ink leakage by recovering all the ink supplied to the inkjet head.

[0011] To achieve the objectives described above, the inkjet head ink supply system equipped with an emergency recovery function according to the present invention is characterized by comprising: an inkjet head equipped with a nozzle for dispensing ink; an ink storage device for storing the ink supplied to the inkjet head; a supply flow path connecting the ink storage device and the inkjet head for supplying the ink stored in the ink storage device to the inkjet head; a recovery flow path connecting the ink storage device and the ink storage device for recovering at least a portion of the ink supplied to the inkjet head back to the ink storage device; and a flow path interrupter installed in the supply flow path and the recovery flow path. At one point, the ink flow between the inkjet head and the ink storage device is blocked in an emergency; a flow path converter, installed at another point in the supply flow path and the return flow path, blocks the ink flow between the inkjet head and the ink storage device in an emergency and connects the drain pipe to the inkjet head; a drain pipe, connected to the flow path converter and connected to the inkjet head in an emergency; an ink discharge storage section, connected to the drain pipe, discharges and stores ink previously supplied to the inkjet head in an emergency; and a drain section for discharging ink previously supplied to the inkjet head in an emergency.

[0012] The ink discharge storage section may further include a return flow path connected between the ink discharge storage section and the ink storage device for returning the ink stored in the ink discharge storage section to the ink storage device.

[0013] The present invention may further include: a return valve, installed in the return flow path, for adjusting the connection between the discharged ink storage section and the ink storage device.

[0014] The discharge section is a gas pressure control device that can apply negative and positive pressure to the discharge ink storage section. It applies negative pressure to the discharge ink storage section when discharging ink that has been supplied to the inkjet head in advance through the discharge pipe, and applies positive pressure to the discharge ink storage section when returning the ink stored in the discharge ink storage section to the ink storage device.

[0015] The flow path blocker is preferably a normally closed valve.

[0016] The flow path blocker preferably has a normally closed valve installed between the inkjet head and the drain pipe, and a normally closed valve installed between the inkjet head and the ink storage device.

[0017] An inkjet printer according to another aspect of the present invention includes an inkjet head ink supply system equipped with an emergency recovery function, characterized in that it comprises: an inkjet head equipped with nozzles for dispensing ink; an ink storage device for storing ink supplied to the inkjet head; a supply flow path connected to the inkjet head for supplying ink stored in the ink storage device; a recovery flow path connected to the ink storage device for recovering at least a portion of the ink supplied to the inkjet head back to the ink storage device; and a flow path interrupter installed in the supply flow path and the recovery flow path. At one point in the supply flow path and the return flow path, the ink flow between the inkjet head and the ink storage device is blocked in an emergency; a flow path converter, installed at another point in the supply flow path and the return flow path, blocks the ink flow between the inkjet head and the ink storage device in an emergency and connects the drain pipe to the inkjet head; a drain pipe, connected to the flow path converter and connected to the inkjet head in an emergency; an ink discharge storage section, connected to the drain pipe, discharges and stores ink previously supplied to the inkjet head in an emergency; and a drain section for discharging ink previously supplied to the inkjet head in an emergency.

[0018] The ink discharge storage section may further include a return flow path connected between the ink discharge storage section and the ink storage device for returning the ink stored in the ink discharge storage section to the ink storage device.

[0019] The present invention may further include: a return valve, installed in the return flow path, for adjusting the connection between the discharged ink storage section and the ink storage device.

[0020] The discharge section is a gas pressure control device that can apply negative and positive pressure to the discharge ink storage section. It applies negative pressure to the discharge ink storage section when discharging ink that has been supplied to the inkjet head in advance through the discharge pipe, and applies positive pressure to the discharge ink storage section when returning the ink stored in the discharge ink storage section to the ink storage device.

[0021] The flow path blocker is preferably a normally closed valve.

[0022] The flow path blocker preferably has a normally closed valve installed between the inkjet head and the drain pipe, and a normally closed valve installed between the inkjet head and the ink storage device.

[0023] The present invention, as described above, can not only disconnect the connection between the inkjet head and the ink storage device in emergency situations such as power outages, but also discharge the ink that has been pre-supplied to the inkjet head, thereby preventing leakage of ink ejected during the diaphragm valve closure process or leakage of ink pre-supplied to the inkjet head through the nozzle.

[0024] In addition, the emergency recovery function can prevent ink leakage, thereby preventing contamination of the printed object or inkjet printer due to ink leakage.

[0025] This can reduce the time spent cleaning and maintaining contaminated inkjet printers before resuming work after an emergency, thereby improving the efficiency of projects using inkjet printers. Attached Figure Description

[0026] Figure 1 This is a schematic diagram illustrating the main components of an inkjet head ink supply system equipped with an emergency recovery function according to a first embodiment of the present invention.

[0027] Figure 2 This is a schematic diagram illustrating the ink supply structure of an ink supply system equipped with an emergency recovery function for inkjet heads, which can be applied according to the present invention.

[0028] Figures 3 to 4 This is a schematic diagram illustrating the process of emergency ink recovery in an inkjet head ink supply system equipped with an emergency recovery function according to a first embodiment of the present invention.

[0029] Figure 5 This is a schematic diagram illustrating the configuration of an inkjet head ink supply system equipped with an emergency recovery function according to a second embodiment of the present invention.

[0030] Figures 6 to 8This is a schematic diagram illustrating the process of emergency ink recovery in an inkjet head ink supply system equipped with an emergency recovery function according to a second embodiment of the present invention.

[0031] [Symbol Explanation]

[0032] 100: Inkjet head

[0033] 200: Ink storage device

[0034] 300: Supply Flow

[0035] 400: Recycle Flow Path

[0036] 510: Flow path blocker

[0037] 520: Flow Path Converter

[0038] 530: drain pipe

[0039] 540: Drainage Department

[0040] 550: Discharge ink storage section

[0041] 570: Return flow path

[0042] 580: Return valve

[0043] 600: Gas pressure control device

[0044] 610: Pressure regulating pipe

[0045] 700: Circulation pump

[0046] 800: Buffer Storage Section Detailed Implementation

[0047] The embodiments to which the present invention is applied will now be described in detail with reference to the accompanying drawings.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] Figure 1 This is a schematic diagram illustrating the main components of an inkjet head ink supply system equipped with an emergency recovery function according to a first embodiment of the present invention. Figure 2 This is a schematic diagram illustrating the ink supply structure of an ink supply system equipped with an emergency recovery function for inkjet heads, which can be applied according to the present invention.

[0052] The inkjet head ink supply system equipped with an emergency recovery function according to the first embodiment of the present invention can be applied to, for example... Figure 2 The inkjet printer shown here is equipped with a circulating ink supply system. The circulating ink supply system will be explained first.

[0053] 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 200. 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.

[0054] The ink storage device 200 is a part for storing ink to supply ink to the inkjet head 100. It is connected to one end of the supply flow path 300 for supplying ink to the inkjet head 100 and the recovery flow path 400 for recycling ink remaining in the inkjet head 100, and is also connected to one end of the pressure regulating pipe 610 for maintaining the state of the meniscus.

[0055] One end of the ink supply path 300 and the other end of the ink recovery path 400 are connected to the inkjet head 100. The inkjet head 100 receives ink through the supply path 300 and performs inkjet printing through the nozzle. At least a portion of the supplied ink is recovered to the ink storage device 200 through the recovery path 400, thereby realizing the circulation of ink.

[0056] The gas pressure control device 600 regulates the pressure of the ink reservoir 200 by connecting to the other end of the pressure regulating pipe 610, thereby creating a negative pressure inside the ink reservoir 200 and maintaining the ink inside the inkjet head 100 in a curved state. As a result, because the configuration continuously draws in air through the pressure regulating pipe 610 except in special circumstances, ink droplets that diffuse upwards when bubbles formed in the ink reservoir 200 burst may be moved through the pressure regulating pipe 610. Ink droplets flowing into the pressure regulating pipe 610 can induce a malfunction in the gas pressure control device 600.

[0057] A circulation pump 700 is installed in a recovery flow path 400 of the ink supplied to the inkjet head 100 to return at least a portion of the ink to the ink storage device 200, thereby circulating the ink. Figure 2 In the embodiment shown, the circulation pump 700 is installed in the recovery flow path 400, but it is not limited to this and can also be installed in the supply flow path 300. As shown, by using the circulation pump 700 to continuously circulate ink between the ink storage device 200 and the inkjet head 100, the dispersibility of the ink can be maintained. At this time, it is advisable to avoid the operation of the circulation pump 700 from affecting the state of the meniscus.

[0058] The buffer reservoir 800 is used to inject ink into the ink storage device without disrupting the meniscus. When adding ink to the buffer reservoir 800, the meniscus does not need to be considered, and ink can be directly added. If printing is stopped while replenishing ink consumed during printing, loss will occur. However, when replenishing ink through the buffer reservoir 800, ink can be replenished without stopping the printing process.

[0059] like Figure 1 As shown, the main components of the ink supply system equipped with an emergency recovery function according to the first embodiment of the present invention are the same as those of a general circulating ink supply system in terms of the ink head 100, ink storage device 200, supply flow path 300 and recovery flow path 400. In addition, the emergency recovery unit also includes a flow path blocker 510, a flow path converter 520, a drain pipe 530, an ink discharge storage unit 550 and a drain unit 540.

[0060] The inkjet head 100 is equipped with nozzles for dispensing ink, and can be used without limitation in the configuration of printheads in general inkjet printers used for industrial purposes.

[0061] The ink storage device 200 is a separate part from the inkjet head 100 that stores the ink supplied to the inkjet head 100. Although not shown, it is connected to a gas pressure control device for maintaining the meniscus state in the inkjet head 100, and may also be connected to a buffer storage device for adding ink while maintaining the meniscus state. The ink storage device 200 described above can be applied without limitation to the configuration of ink storage devices in general inkjet printers without prejudice to the features of this invention.

[0062] The supply flow path 300 is a conduit used to supply ink stored in the ink reservoir 200 to the printhead 100. As described above, in order to make industrial inkjet printers suitable for mass production processes, a continuous ink supply is required. Therefore, a structure where the printhead and ink reservoir are separated is used, instead of the cartridge structure where the reservoir is integrated into the printhead used in past small document printers. The inkjet head ink supply system equipped with an emergency recovery function in this embodiment is also a structure where the printhead 100 and ink reservoir 200 are separated. One end is connected to the ink reservoir 200, and the other end supplies ink stored in the ink reservoir 200 to the printhead 100 through the supply flow path 300 connected to the printhead 100. A flow path blocker 510 is installed in the supply flow path 300, but other than that, a configuration used in general ink reservoirs for supplying ink to the printhead can be used without limitation.

[0063] The recovery flow path 400 is configured to prevent ink stagnation and maintain continuous flow by recirculating at least a portion of the ink supplied from the ink reservoir 200 to the ink head 100 back to the ink reservoir. Currently, in inkjet printers where the ink head and ink reservoir are separated, only unidirectional ink movement is possible, allowing ink to be supplied from the ink reservoir to the ink head. However, with the diversification of ink compositions for industrial inkjet printers, maintaining ink uniformity has become crucial. Furthermore, as inks containing dispersed particles are increasingly used, preventing particle sedimentation and maintaining a uniformly dispersed state has become even more important. To maintain ink uniformity and dispersion, various technical elements can be applied to the ink reservoir, among which a structure as described in this embodiment, which allows continuous ink flow by recirculating at least a portion of the ink supplied to the ink head 100 back to the ink reservoir 200, can be used without limitation. A flow path converter 520 is installed in the recovery flow path 400; however, configurations used in general ink head systems for recirculating ink to the ink reservoir can also be used without limitation.

[0064] The inkjet head 100, ink storage device 200, supply flow path 300, and recovery flow path 400 described above can be applied without limitation to existing technologies without prejudice to the features of the present invention.

[0065] Next, the flow path blocker 510, flow path converter 520, drain pipe 530, ink discharge storage section 550, and drain section 540, which are particularly suitable for use as emergency recovery sections in this embodiment, will be described.

[0066] A flow path interrupter 510 is installed in the supply flow path 300 to prevent ink from moving through the supply flow path 300. Different structures can be used for the flow path interrupter 510, but a normally closed valve that is closed when there is no power supply and only opens when there is power is preferred. In this embodiment, the flow path interrupter 510 is configured to prevent ink stored in the ink storage device 200 from flowing into the inkjet head 100 and leaking in emergency situations such as power outages. By using a normally closed valve that blocks flow when there is no power supply, the supply flow path 300 can be blocked in the event of a power outage, thereby preventing ink stored in the ink storage device 200 from flowing into the inkjet head 100. The accompanying drawings illustrate a normally closed valve that blocks fluid flow through a diaphragm, but this is not a limitation; normally closed valves of various structures can be used without prejudice to the features of the invention.

[0067] A flow path converter 520 is installed in the recovery flow path 400 and can perform the action of changing the fluid flow direction of the recovery flow path 400, which connects the inkjet head 100 and the ink storage device 200, to the drain pipe 530. The recovery flow path 400, installed to maintain ink uniformity and dispersion, is used to move ink from the inkjet head 100 to the ink storage device 200. However, in the event of loss of control due to conditions such as a power outage, it can become a channel for backflow of ink from the ink storage device 200 back into the inkjet head 100. In this case, a structure can be used to block the movement of ink through the recovery flow path 400 during a power outage by also installing a flow path blocker in the recovery flow path 400. However, even under the aforementioned conditions, the existing problem of ink leakage already supplied to the inkjet head 100 cannot be solved. In this embodiment, a method is used to connect the drain pipe 530, which discharges ink filled into the inkjet head 100 to the outside, to the recovery flow path 400 and change the connection direction using the flow path converter 520. The flow path converter 520 can be a three-way valve that changes the connection direction between the recovery flow path connected to the inkjet head 100, the recovery flow path connected to the ink storage device 200, and the drain pipe 530. In particular, by using a normally closed valve in the bidirectional connection to the recovery flow path to block flow in the absence of power, and a normally open valve in the connection to the drain pipe 530 to open flow in the absence of power, the recovery flow path 400 can be blocked during a power outage, preventing ink stored in the ink storage device 200 from flowing into the inkjet head 100, and the ink filled in the inkjet head 100 can be discharged to the outside through the drain pipe 530. The accompanying drawings illustrate a three-way valve comprising a normally closed valve that blocks fluid flow at a diaphragm location and a normally open valve, but this is not a limitation; valves of various structures can be used without prejudice to the characteristics of the invention.

[0068] The drain pipe 530 is connected to the recovery flow path 400. Normally, the movement of ink is blocked by the flow path converter 520. However, in the event of a power outage, the flow path converter 520 connects to the recovery flow path 400 on the side of the inkjet head 100, thus becoming a channel for the movement of ink that fills the inkjet head 100.

[0069] The ink storage section 550 is connected to the other end of the drain pipe 530 to store the ink supplied to the inkjet head 100 that moves through the drain pipe 530. Because inks used for industrial purposes may contain components that are harmful to humans or the environment, it is advisable to store them in a separate storage space.

[0070] The drain section 540 generates a force to move the ink filled in the inkjet head 100 through the drain pipe 530 to the ink discharge reservoir 550. Various techniques can be applied to move the ink filled in the inkjet head 100; for example, the ink can be drawn into the inkjet head 100 and moved to the ink discharge reservoir 550 by the negative pressure of a vacuum pump or gas pressure regulating device. Since the drain section 540 operates under conditions such as power outages, it is preferable that it be equipped with its own power supply, and to reduce power consumption, it is advisable that it remain in standby mode and only operate in emergency situations.

[0071] The first embodiment illustrated is a structure in which the flow path blocker 510 is installed in the supply flow path 300 and the flow path converter 520 is installed in the return flow path 400. However, it is not limited to this. The flow path blocker 510 can also be installed in the return flow path 400 and the flow path converter 520 can be installed in the supply flow path 300.

[0072] Figures 3 to 4 This is a schematic diagram illustrating the process of emergency ink recovery in an inkjet head ink supply system equipped with an emergency recovery function according to a first embodiment of the present invention.

[0073] In the event of an emergency such as a power outage that causes the power supply to be cut off, the power supply to the flow path interruptor 510 and the flow path converter 520 will also be cut off.

[0074] In the situation described above, such as Figure 3 As shown, the flow path interrupter 510, which uses a normally closed valve, closes and blocks the supply flow path 300, thereby preventing ink stored in the ink reservoir 200 from flowing into the inkjet head 100. Furthermore, the normally closed portion of the three-way valve constituting the flow path converter 520 closes and blocks the movement of ink through the recovery flow path 400, thereby preventing ink stored in the ink reservoir 200 from flowing into the inkjet head 100. At this time, the normally closed portion of the three-way valve constituting the flow path converter 520 closes while the normally open portion opens, thereby connecting the inkjet head 100 to the drain pipe 530. However, even when the flow between the inkjet head 100 and the ink reservoir 200 is blocked using the flow path interrupter 510 and the flow path converter 520, it is still impossible to prevent ink leakage through the inkjet head 100. First, during the closure of the flow path interruptor 510 and flow path converter 520 of the valve using the diaphragm method, a small amount of ink is ejected from the diaphragm. This results in a small amount of ink additionally flowing into the printhead 100, causing leakage through the printhead. Furthermore, in the event of an emergency such as a power outage lasting for an extended period, the loss of control over the printhead 100 can lead to continuous leakage of ink previously supplied to the printhead 100.

[0075] In this embodiment, to prevent ink already supplied to the inkjet head 100 from leaking through the nozzle, a structure is used to discharge it to the outside via a drain pipe 530. For example... Figure 4 As shown, when the flow path converter 520 is working, the inkjet head 100 is connected to the drain pipe 530. At the same time, the drain section 540 will start working and generate suction force through the drain pipe 530, so that the ink pre-filled in the inkjet head 100 moves through the drain pipe 530 and is stored in the discharged ink storage section 550.

[0076] Through the process described above, leakage caused by ink ejected by the diaphragm can be prevented during the closure of the flow path blocker 510 and flow path converter 520 of the valve with diaphragm type. Furthermore, since the ink supplied to the inkjet head 100 is discharged to the outside through the drain pipe 530, the problem of ink leakage through the nozzle can also be solved.

[0077] Inkjet printers equipped with an inkjet head ink supply system featuring an emergency recovery function, as described above, will not leak ink even in emergencies such as power outages. This prevents contamination of the printed object or the inkjet printer due to ink leakage. Furthermore, it reduces the time spent cleaning and maintaining a contaminated inkjet printer before resuming work after an emergency, thereby improving the efficiency of projects using inkjet printers.

[0078] Figure 5 This is a schematic diagram illustrating the configuration of an ink supply system for an inkjet head equipped with an emergency recovery function according to a second embodiment of the present invention. Figure 2 This is a schematic diagram illustrating the ink supply structure of an ink supply system equipped with an emergency recovery function for inkjet heads, which can be applied according to the present invention.

[0079] The ink supply system for an inkjet head equipped with an emergency recovery function according to the second embodiment of the present invention can be applied to, for example... Figure 2 The inkjet printer shown here is equipped with a circulating ink supply system. The circulating ink supply system will be explained first.

[0080] 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 200. 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.

[0081] The ink storage device 200 is a part for storing ink to supply ink to the inkjet head 100. It is connected to one end of the supply flow path 300 for supplying ink to the inkjet head 100 and the recovery flow path 400 for recycling ink remaining in the inkjet head 100, and is also connected to one end of the pressure regulating pipe 610 for maintaining the state of the meniscus.

[0082] One end of the ink supply path 300 and the other end of the ink recovery path 400 are connected to the inkjet head 100. The inkjet head 100 receives ink through the supply path 300 and performs inkjet printing through the nozzle. At least a portion of the supplied ink is recovered to the ink storage device 200 through the recovery path 400, thereby realizing the circulation of ink.

[0083] The gas pressure control device 600 regulates the pressure of the ink reservoir 200 by connecting to the other end of the pressure regulating pipe 610, thereby creating a negative pressure inside the ink reservoir 200 and maintaining the ink inside the inkjet head 100 in a curved state. As a result, because the configuration continuously draws in air through the pressure regulating pipe 610 except in special circumstances, ink droplets that diffuse upwards when bubbles formed in the ink reservoir 200 burst may be moved through the pressure regulating pipe 610. Ink droplets flowing into the pressure regulating pipe 610 can induce a malfunction in the gas pressure control device 600.

[0084] A circulation pump 700 is installed in a recovery flow path 400 of the ink supplied to the inkjet head 100 to return at least a portion of the ink to the ink storage device 200, thereby circulating the ink. Figure 2 In the embodiment shown, the circulation pump 700 is installed in the recovery flow path 400, but it is not limited to this and can also be installed in the supply flow path 300. As shown, by using the circulation pump 700 to continuously circulate ink between the ink storage device 200 and the inkjet head 100, the dispersibility of the ink can be maintained. At this time, it is advisable to avoid the operation of the circulation pump 700 from affecting the state of the meniscus.

[0085] The buffer reservoir 800 is used to inject ink into the ink storage device without disrupting the meniscus. When adding ink to the buffer reservoir 800, the meniscus does not need to be considered, and ink can be directly added. If printing is stopped while replenishing ink consumed during printing, loss will occur. However, when replenishing ink through the buffer reservoir 800, ink can be replenished without stopping the printing process.

[0086] like Figure 2As shown, the main components of the ink supply system equipped with an emergency recovery function according to the second embodiment of the present invention are the same as those of a general circulating ink supply system in terms of the ink head 100, ink storage device 200, supply flow path 300 and recovery flow path 400. In addition, the emergency recovery unit also includes a flow path blocker 510, a flow path converter 520, a drain pipe 530, an ink discharge storage unit 550, a drain unit 540 and a return flow path 570.

[0087] The inkjet head 100 is equipped with nozzles for dispensing ink, and can be used without limitation in the configuration of printheads in general inkjet printers used for industrial purposes.

[0088] The ink storage device 200 is a separate part from the inkjet head 100 that stores the ink supplied to the inkjet head 100. Although not shown, it is connected to a gas pressure control device for maintaining the meniscus state in the inkjet head 100, and may also be connected to a buffer storage device for adding ink while maintaining the meniscus state. The ink storage device 200 described above can be applied without limitation to the configuration of ink storage devices in general inkjet printers without prejudice to the features of this invention.

[0089] The supply flow path 300 is a conduit used to supply ink stored in the ink reservoir 200 to the printhead 100. As described above, in order to make industrial inkjet printers suitable for mass production processes, a continuous ink supply is required. Therefore, a structure where the printhead and ink reservoir are separated is used, instead of the cartridge structure where the reservoir is integrated into the printhead used in past small document printers. The inkjet head ink supply system equipped with an emergency recovery function in this embodiment is also a structure where the printhead 100 and ink reservoir 200 are separated. One end is connected to the ink reservoir 200, and the other end supplies ink stored in the ink reservoir 200 to the printhead 100 through the supply flow path 300 connected to the printhead 100. A flow path blocker 510 is installed in the supply flow path 300, but other than that, a configuration used in general ink reservoirs for supplying ink to the printhead can be used without limitation.

[0090] The recovery flow path 400 is configured to prevent ink stagnation and maintain continuous flow by recirculating at least a portion of the ink supplied from the ink reservoir 200 to the ink head 100 back to the ink reservoir. Currently, in inkjet printers where the ink head and ink reservoir are separated, only unidirectional ink movement is possible, allowing ink to be supplied from the ink reservoir to the ink head. However, with the diversification of ink compositions for industrial inkjet printers, maintaining ink uniformity has become crucial. Furthermore, as inks containing dispersed particles are increasingly used, preventing particle sedimentation and maintaining a uniformly dispersed state has become even more important. To maintain ink uniformity and dispersion, various technical elements can be applied to the ink reservoir, among which a structure as described in this embodiment, which allows continuous ink flow by recirculating at least a portion of the ink supplied to the ink head 100 back to the ink reservoir 200, can be used without limitation. A flow path converter 520 is installed in the recovery flow path 400; however, configurations used in general ink head systems for recirculating ink to the ink reservoir can also be used without limitation.

[0091] The inkjet head 100, ink storage device 200, supply flow path 300, and recovery flow path 400 described above can be applied without limitation to existing technologies without prejudice to the features of the present invention.

[0092] Next, the flow path blocker 510, flow path converter 520, drain pipe 530, ink discharge storage section 550, drain section 540 and return flow path 570, which are particularly suitable for this embodiment as emergency recovery section, will be described.

[0093] A flow path interrupter 510 is installed in the supply flow path 300 to prevent ink from moving through the supply flow path 300. Different structures can be used for the flow path interrupter 510, but a normally closed valve that is closed when there is no power supply and only opens when there is power is preferred. In this embodiment, the flow path interrupter 510 is configured to prevent ink stored in the ink storage device 200 from flowing into the inkjet head 100 and leaking in emergency situations such as power outages. By using a normally closed valve that blocks flow when there is no power supply, the supply flow path 300 can be blocked in the event of a power outage, thereby preventing ink stored in the ink storage device 200 from flowing into the inkjet head 100. The accompanying drawings illustrate a normally closed valve that blocks fluid flow through a diaphragm, but this is not a limitation; normally closed valves of various structures can be used without prejudice to the features of the invention.

[0094] A flow path converter 520 is installed in the recovery flow path 400 and can perform the action of changing the fluid flow direction of the recovery flow path 400, which connects the inkjet head 100 and the ink storage device 200, to the drain pipe 530. The recovery flow path 400, installed to maintain ink uniformity and dispersion, is used to move ink from the inkjet head 100 to the ink storage device 200. However, in the event of loss of control due to conditions such as a power outage, it can become a channel for backflow of ink from the ink storage device 200 back into the inkjet head 100. In this case, a structure can be used to block the movement of ink through the recovery flow path 400 during a power outage by also installing a flow path blocker in the recovery flow path 400. However, even under the aforementioned conditions, the existing problem of ink leakage already supplied to the inkjet head 100 cannot be solved. In this embodiment, a method is used to connect the drain pipe 530, which discharges ink filled into the inkjet head 100 to the outside, to the recovery flow path 400 and change the connection direction using the flow path converter 520. The flow path converter 520 can be a three-way valve that changes the connection direction between the recovery flow path connected to the inkjet head 100, the recovery flow path connected to the ink storage device 200, and the drain pipe 530. In particular, by using a normally closed valve in the bidirectional connection to the recovery flow path to block flow in the absence of power, and a normally open valve in the connection to the drain pipe 530 to open flow in the absence of power, the recovery flow path 400 can be blocked during a power outage, preventing ink stored in the ink storage device 200 from flowing into the inkjet head 100, and the ink filled in the inkjet head 100 can be discharged to the outside through the drain pipe 530. The accompanying drawings illustrate a three-way valve comprising a normally closed valve that blocks fluid flow at a diaphragm location and a normally open valve, but this is not a limitation; valves of various structures can be used without prejudice to the characteristics of the invention.

[0095] The drain pipe 530 is connected to the recovery flow path 400. Normally, the movement of ink is blocked by the flow path converter 520. However, in the event of a power outage, the flow path converter 520 connects to the recovery flow path 400 on the side of the inkjet head 100, thus becoming a channel for the movement of ink that fills the inkjet head 100.

[0096] The ink storage section 550 is connected to the other end of the drain pipe 530 to store the ink supplied to the inkjet head 100 that moves through the drain pipe 530. Because inks used for industrial purposes may contain components that are harmful to humans or the environment, it is advisable to store them in a separate storage space.

[0097] The drain section 540 generates a force to move the ink filled in the inkjet head 100 through the drain pipe 530 to the ink discharge reservoir 550. Various techniques can be applied to move the ink filled in the inkjet head 100; for example, the ink can be drawn into the inkjet head 100 and moved to the ink discharge reservoir 550 by the negative pressure of a vacuum pump or gas pressure regulating device. Since the drain section 540 operates under conditions such as power outages, it is preferable that it be equipped with its own power supply, and to reduce power consumption, it is advisable that it remain in standby mode and only operate in emergency situations.

[0098] A return flow path 570 is formed between the ink discharge storage section 550 and the ink storage device 200, and is configured to return the ink stored in the ink discharge storage section 550 to the ink storage device 200. To selectively perform the operation of returning the ink stored in the ink discharge storage section 550 to the ink storage device 200, a return valve 580 can be installed on the return flow path 570. Alternatively, a pump or similar device can be provided for returning ink to the ink storage device 200 via the return flow path 570; however, this embodiment employs a structure utilizing the negative pressure generated in the discharge section 540 of a suitable gas pressure regulating device.

[0099] Furthermore, during the process of returning the ink stored in the discharge ink storage section 550 to the ink storage device 200 via the return flow path 570, the ink stored in the discharge ink storage section 550 may flow into the drain pipe 530. At this time, due to the operation of the flow path converter 520 connected to the drain pipe 530, the ink will not be able to enter the recovery flow path 400 through the drain pipe 530. However, if the ink flows into the drain pipe 530, it will lead to a reduction in the amount recovered into the ink storage device 200. As shown in the illustrated embodiment, ink can be prevented from flowing into the drain pipe 530 by specifying the installation position of the drain pipe 530 and the return flow path 570, or a suitable valve can be added at the location where the drain pipe 530 is connected.

[0100] The second embodiment illustrated is a structure in which the flow path blocker 510 is installed in the supply flow path 300 and the flow path converter 520 is installed in the return flow path 400. However, it is not limited to this. The flow path blocker 510 can also be installed in the return flow path 400 and the flow path converter 520 can be installed in the supply flow path 300.

[0101] Figures 6 to 8 This is a schematic diagram illustrating the process of emergency ink recovery in an inkjet head ink supply system equipped with an emergency recovery function according to a second embodiment of the present invention.

[0102] In the event of an emergency such as a power outage that causes the power supply to be cut off, the power supply to the flow path interruptor 510 and the flow path converter 520 will also be cut off.

[0103] In the situation described above, such as Figure 6 As shown, the flow path interrupter 510, which uses a normally closed valve, closes and blocks the supply flow path 300, thereby preventing ink stored in the ink reservoir 200 from flowing into the inkjet head 100. Furthermore, the normally closed portion of the three-way valve constituting the flow path converter 520 closes and blocks the movement of ink through the recovery flow path 400, thereby preventing ink stored in the ink reservoir 200 from flowing into the inkjet head 100. At this time, the normally closed portion of the three-way valve constituting the flow path converter 520 closes while the normally open portion opens, thereby connecting the inkjet head 100 to the drain pipe 530. However, even when the flow between the inkjet head 100 and the ink reservoir 200 is blocked using the flow path interrupter 510 and the flow path converter 520, it is still impossible to prevent ink leakage through the inkjet head 100. First, during the closure of the flow path interrupter 510 and flow path converter 520 of the valve using the diaphragm method, a small amount of ink is ejected from the diaphragm, resulting in a small amount of ink additionally flowing into the inkjet head 100 and causing leakage through the inkjet head. Furthermore, in the event of an emergency such as a prolonged power outage, the ink previously supplied to the inkjet head 100 may continue to leak due to loss of control over the inkjet head 100. At this time, the return valve 580 installed in the return flow path 570 is in the closed state.

[0104] In this embodiment, to prevent ink already supplied to the inkjet head 100 from leaking through the nozzle, a structure is used to discharge it to the outside via a drain pipe 530. For example... Figure 7 As shown, when the flow path converter 520 is working, the inkjet head 100 is connected to the drain pipe 530. At the same time, the drain section 540 starts working and generates suction force through the drain pipe 530, so that the ink pre-filled in the inkjet head 100 moves through the drain pipe 530 and is stored in the discharged ink storage section 550. At this time, the return valve 580 is also in the closed state.

[0105] Through the process described above, leakage caused by ink ejected by the diaphragm can be prevented during the closure of the flow path blocker 510 and flow path converter 520 of the valve with diaphragm type. Furthermore, since the ink supplied to the inkjet head 100 is discharged to the outside through the drain pipe 530, the problem of ink leakage through the nozzle can also be solved.

[0106] In this embodiment, ink utilization can be improved by returning the ink that has been urgently recovered and stored in the discharged ink storage section 550 to the ink storage device 200. At this time, a separate pump or the like can also be used, but... Figure 8 As shown, ink stored in the discharged ink storage section 550 can be returned to the ink storage device 200 by applying positive pressure from the drain section 540, which is configured using a gas pressure control device. As described above, in order to return the ink stored in the discharged ink storage section 550 to the ink storage device 200 using the positive pressure of the drain section 540, it is necessary to open the return valve 580 and close the valve connected to the drain pipe 530 in the flow path converter 520. At this time, as shown in the embodiment, ink can be prevented from flowing into the drain pipe 530 by specifying the installation position of the drain pipe 530 and the return flow path 570, or an applicable valve can be added at the location where the drain pipe 530 is connected.

[0107] As described above, the operation of returning the ink stored in the ink discharge storage section 550 to the ink storage device 200 can be performed after all emergency situations have been resolved and power has been restored, or it can be performed without resolving all emergency situations. However, in the absence of power restoration, since the valve connected to the drain pipe 530 in the flow path converter 520 may be open, it is necessary to perform the operation with the valve connected to the drain pipe 530 closed by operating the flow path converter 520 separately.

[0108] Inkjet printers equipped with an inkjet head ink supply system featuring an emergency recovery function, as described above, will not leak ink even in emergencies such as power outages. This prevents contamination of the printed object or the inkjet printer due to ink leakage. Furthermore, it reduces the time spent cleaning and maintaining a contaminated inkjet printer before resuming work after an emergency, thereby improving the efficiency of projects using inkjet printers.

[0109] 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 supply system for an inkjet head equipped with an emergency recovery function, characterized by, An ink jet head equipped with nozzles for discharging ink; An ink storage device for storing ink supplied to the ink jet head; A supply flow path connecting the ink stored in the ink storage device to the ink jet head; A recovery flow path connecting at least a part of the ink supplied to the ink jet head to the ink storage device; A flow path stopper installed at one of the supply flow path and the recovery flow path to stop the flow of ink between the ink jet head and the ink storage device in an emergency; A flow path switcher installed at the other of the supply flow path and the recovery flow path to stop the flow of ink between the ink jet head and the ink storage device and connect a drain pipe to the ink jet head in an emergency; A drain pipe connected to the flow path switcher and connected to the ink jet head in an emergency; An ink discharge storage section connected to the drain pipe and discharging the ink previously supplied to the ink jet head and storing it in an emergency; A drain section for discharging the ink previously supplied to the ink jet head in an emergency. Further comprising: A return flow path connecting the ink stored in the ink discharge storage section to the ink storage device to return the ink to the ink storage device.

2. The inkjet head ink supply system equipped with an emergency recovery function according to claim 1, characterized by, Further comprising: A return valve installed in the return flow path to regulate the connection between the ink discharge storage section and the ink storage device.

3. The inkjet head ink supply system equipped with an emergency recovery function according to claim 2, characterized by, 4. The ink jet head ink supply system equipped with an emergency recovery function according to claim 2, wherein: The drain section is a gas pressure control device capable of applying negative pressure and positive pressure to the ink discharge storage section, The negative pressure is applied to the ink discharge storage section when discharging the ink previously supplied to the ink jet head through the drain pipe, The positive pressure is applied to the ink discharge storage section when returning the ink stored in the ink discharge storage section to the ink storage device.

5. The ink jet head ink supply system equipped with an emergency recovery function according to claim 1, wherein: The flow path stopper is a normally closed valve.

6. The ink jet head ink supply system equipped with an emergency recovery function according to claim 1, wherein: The flow path stopper installs a normally closed valve between the ink jet head and the drain pipe and a normally closed valve between the ink jet head and the ink storage device. An ink jet head equipped with nozzles for discharging ink; An ink storage device for storing ink supplied to the ink jet head; 7. An inkjet printer comprising an ink supply system for an inkjet head equipped with an emergency recovery function, characterized by A supply flow path connecting the ink stored in the ink storage device to the ink jet head; A recovery flow path connecting at least a part of the ink supplied to the ink jet head to the ink storage device; A flow path stopper installed at one of the supply flow path and the recovery flow path to stop the flow of ink between the ink jet head and the ink storage device in an emergency; A flow path switcher installed at the other of the supply flow path and the recovery flow path to stop the flow of ink between the ink jet head and the ink storage device and connect a drain pipe to the ink jet head in an emergency; ​ ​ ​ a drain pipe connected to the flow path switcher and connected to the inkjet head in an emergency; an ink discharge reservoir connected to the drain pipe and discharging and storing the ink previously supplied to the inkjet head in an emergency; and a drain section for discharging the ink previously supplied to the inkjet head in an emergency.

8. The inkjet printer comprising the ink supply system for an inkjet head equipped with an emergency recovery function according to claim 7, characterized by, Further comprising: a return flow path connected between the ink discharge reservoir and the ink storage device for returning the ink stored in the ink discharge reservoir to the ink storage device.

9. The inkjet printer comprising the ink supply system for an inkjet head equipped with an emergency recovery function according to claim 8, characterized by, Further comprising: a return valve installed in the return flow path and regulating the connection between the ink discharge reservoir and the ink storage device.

10. The inkjet printer comprising the inkjet head ink supply system equipped with an emergency recovery function according to claim 8, characterized in that: the drain section is a gas pressure control device capable of applying negative pressure and positive pressure to the ink discharge reservoir, negative pressure is applied to the ink discharge reservoir when discharging the ink previously supplied to the inkjet head through the drain pipe, and positive pressure is applied to the ink discharge reservoir when returning the ink stored in the ink discharge reservoir to the ink storage device.

11. The inkjet printer comprising the inkjet head ink supply system equipped with an emergency recovery function according to claim 7, characterized in that: the flow path blocker is a normally closed valve.

12. The inkjet printer comprising the inkjet head ink supply system equipped with an emergency recovery function according to claim 7, characterized in that: the flow path blocker installs a normally closed valve between the inkjet head and the drain pipe, and installs a normally closed valve between the inkjet head and the ink storage device.

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