JP2012086544A - Ink circulation device, inkjet printer including the same, and ink circulation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink circulation device, an inkjet printer including the ink circulation device, and an ink circulation method.SOLUTION: The ink circulation device includes: an ink supply section; an ink supply path to connect between an inkjet print head and the ink supply section; an ink recovery section to recover the ink not ejected from the inkjet print head; an ink recovery path to connect between the inkjet print head and the ink recovery section; an ink return path to return the ink lying in the ink recovery section to the ink supply section; and a control section configured to, in the case of supplying the ink to the inkjet print head, make the pressure of the ink supply section higher than that of the ink recovery section, close a first valve provided in the ink return path, open a second valve provided in the ink supply path and a third valve provided in the ink recovery path, on the other hand, in the case of returning the ink from the ink recovery section to the ink supply section, make the pressure of the ink recovery section higher than that of the ink supply section, open the first valve and close the second and third valves.

Description

  The present invention relates to an ink circulation device, an ink jet printer including the ink circulation device, and an ink circulation method.

  An ink jet printer discharges ink from an ink jet print head by driving the ink jet print head, and dissolves in ink existing in the ink jet print head due to pressure change and temperature change generated when the ink jet print head is driven. Micro air is generated as bubbles. As a result, there is a problem that non-ejection of ink and deviation of ink ejection occur, and the substrate or the like can be uneven after ink ejection.

  Accordingly, the ink jet printer is configured so as to exclude a portion where air clogging occurs in the supply path for supplying ink to the ink jet print head, or the degassed ink is provided by providing a deaeration device in the supply path. The ink jet print head is configured to be supplied.

  In an ink jet printer provided with a deaeration device, for example, an inlet and an outlet of a deaeration module are connected in series to a pipe serving as the supply path. Further, a vacuum pump is connected to the degassing module in order to maintain a vacuum in the degassing module. Thereby, an ink from which the gas dissolved in the ink is removed, that is, a deaerated ink is manufactured, and the deaerated ink is supplied to the ink jet print head through the supply path. Accordingly, it is possible to control the reduction of bubbles generated by driving the ink jet head and the non-ejection of ink generated as the gas remaining in the pipe in the initial state is dissolved in the ink.

  However, when such a deaerated ink is manufactured and supplied, when the deaerated ink comes into contact with air, the air is dissolved in the ink, and the air is immediately returned to a saturated state. is there.

  Therefore, it is required to supply high deaeration ink to the ink jet print head while maintaining the deaeration degree of the ink without leaving air in the supply path.

  In recent years, inkjet printers have been widely used for industrial purposes. For example, an ink produced by melting a metal such as gold or silver on a flexible printed circuit board (FPCB) is ejected to directly form a circuit pattern. It is used for manufacturing industrial graphics, liquid crystal displays (LCDs) and organic light emitting diodes (OLEDs), and solar cells.

  At this time, since solid fine particles such as gold and silver are dispersed in the ink component, if the ink is not circulated, the solid component will settle, resulting in an ejection failure.

  The present invention has been made to solve the above-described problems of the prior art, and supplies sufficiently degassed ink to an ink jet print head so that solid components in the ink settle. It is an object of the present invention to provide an ink circulation device that can be prevented, an ink jet printer including the ink circulation device, and an ink circulation method.

  An ink circulation device according to an embodiment of the present invention includes an ink supply unit that supplies ink to an inkjet print head, an ink supply path that connects the inkjet print head and the ink supply unit, and an ejection from the inkjet print head. An ink collecting section that collects unrecovered ink, an ink collecting path that connects the ink jet print head and the ink collecting section, an ink return path that returns the ink in the ink collecting section to the ink supply section, and When ink is supplied to the ink jet print head, the pressure of the ink supply unit is made higher than the pressure of the ink recovery unit, the first valve provided in the ink return path is closed, and the second provided in the ink supply path. And the third valve provided in the ink recovery path are opened to When the ink is returned from the ink collection unit to the ink supply unit, the pressure of the ink collection unit is made higher than the pressure of the ink supply unit, the first valve is opened, and the second valve and the third valve are opened. And a controller for closing.

  In the ink circulation device according to an embodiment of the present invention, the control unit sets the pressure of the ink recovery unit to a negative pressure state when supplying the ink, and sets the pressure of the ink supply unit to negative when the ink returns. Pressure state.

  In the ink circulation device according to an embodiment of the present invention, the control unit may set the height of the ink supply unit to be higher than the height of the ink recovery unit when the ink is supplied, and return the ink when the ink is restored. The height of the recovery unit can be made higher than the height of the ink supply unit.

  In addition, the ink circulation device according to an embodiment of the present invention may further include a filter unit in which a gap smaller than the diameter of the nozzle of the inkjet print head is formed on the inkjet print head side of the ink supply path. .

  In the ink circulation device according to an embodiment of the present invention, the ink supply unit may include an ink pack filled with ink from which gas has been removed.

  In the ink circulation device according to the embodiment of the invention, the ink supply unit, the ink recovery unit, the ink supply path, the ink recovery path, and the ink return path may be multilayered so that air is blocked. Can be formed into a structure.

  In the ink circulation device according to an embodiment of the present disclosure, the ink supply unit may include a vibrating unit that vibrates the ink supply unit so as to prevent the ink from sinking.

  In the ink circulation device according to an embodiment of the present invention, the ink supply unit and the ink recovery unit include a load cell that measures ink weight, and the control unit measures supply and return of ink by the load cell. It can be determined by the ink weight of the ink supply unit and the ink recovery unit.

  At this time, if the ink weight of the ink supply unit and the ink recovery unit measured by the load cell is equal to or less than a preset weight, the control unit can warn ink filling.

  In another aspect of the present invention, an ink jet printer according to the present invention includes the ink circulation device, an ink jet print head that is supplied with ink from the ink circulation device and discharges the ink, the ink jet print head, and the ink supply path. And a sub tank for storing ink between the ink collecting path and the ink collecting path.

  At this time, the control unit can place the sub tank in a negative pressure state so as to remove the gas in the inkjet print head when the ink is supplied.

  In yet another aspect of the present invention, the ink circulation method according to the present invention closes the first valve of the ink return path and closes the second ink supply path when the pressure of the ink supply section becomes higher than the pressure of the ink recovery section. A step of opening a valve to supply ink to the ink jet print head through the ink supply path, and when printing by the ink jet print head is completed, a third valve of the ink recovery path is opened to eject ink from the ink jet print head. Recovering the unrecovered ink to the ink recovery part via the ink recovery path, and when the pressure of the ink recovery part becomes higher than the pressure of the ink supply part, the second valve of the ink supply path and the Close the third valve in the ink recovery path and open the first valve in the ink return path to open the ink The ink of the ink recovery unit through the return may include a step of returning to the ink supply portion.

  In the ink circulation method according to the present invention, the pressure of the ink supply unit and the ink recovery unit may be adjusted by setting one of the ink supply unit and the ink recovery unit to a negative pressure state. it can.

  In the ink circulation method according to the present invention, the pressures of the ink supply unit and the ink recovery unit can be adjusted by adjusting the heights of the ink supply unit and the ink recovery unit.

  The ink circulation method according to the present invention may further include a step of alarming ink filling when the ink weight of the ink supply unit and the ink recovery unit is equal to or less than a preset weight.

  According to the ink circulation device, the ink jet printer including the ink circulation device, and the ink circulation method according to the present invention, it is possible to supply the ink that has been sufficiently deaerated to the ink jet print head and prevent the solid component in the ink from settling. .

1 is a drawing schematically showing an ink circulation device according to a first embodiment of the present invention. 4 is a diagram illustrating an ink supply path and an ink recovery path in the ink circulation device according to the first embodiment of the present invention. 4 is a diagram illustrating an ink return path in the ink circulation device according to the first embodiment of the present invention. 4 is a schematic view illustrating an ink circulation device according to a second embodiment of the present invention. 6 is a diagram illustrating an ink supply path and an ink recovery path in an ink circulation device according to a second embodiment of the present invention. 6 is a diagram illustrating an ink return path in an ink circulation device according to a second embodiment of the present invention. 6 is a diagram schematically illustrating an ink circulation device according to a third embodiment of the present invention.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. However, the idea of the present invention is not limited to the presented embodiments, and those skilled in the art who understand the idea of the present invention can add, change, and delete other components within the scope of the same idea. Other embodiments that fall within the scope of the invention and other embodiments included within the spirit of the present invention can be easily proposed, but it should be said that these are also included within the scope of the present invention.

  In addition, the component with the same function within the range of the same idea shown by drawing of each embodiment attaches | subjects and demonstrates the same referential mark.

  FIG. 1 schematically shows an ink circulation device according to the first embodiment of the present invention, FIG. 2 shows an ink supply path in the ink circulation device according to the first embodiment of the present invention, and FIG. 1 is a diagram illustrating an ink return path in an ink circulation device according to a first embodiment of the present invention.

  1 to 3, the ink circulation device 100 according to the first embodiment of the present invention may include an ink supply unit 110, an ink recovery unit 120, and a control unit.

  The ink supply unit 110 supplies ink to the inkjet print head 130 along the ink supply path, and includes an ink supply pack 112 filled with sufficiently degassed ink, and the ink supply pack 112. Vibrating means 114 for vibrating the ink and a first load cell 116 for measuring the ink weight of the ink supply pack 112 can be included.

  The ink supply pack 112 may be formed in a multilayer structure so that air is blocked.

  The vibration means 114 applies vibration to the ink supply pack 112 so that solid components such as gold and silver in the ink do not settle, and a piezoelectric body or an ultrasonic element can be used. .

  The first load cell 116 is a device that measures the weight of ink in the ink supply pack 112. In the present embodiment, the load cell is described as an example, but the present invention is limited to this. Needless to say, any apparatus capable of measuring the weight of normal ink can be used.

  The ink supply unit 110 may include a heater (not shown) in order to maintain the ink in the ink supply pack 112 at a constant temperature.

  The ink collection unit 120 collects ink that has not been ejected from the inkjet print head 130, and includes an ink collection pack 122 that is filled with the collected ink, and a second ink that measures the ink weight of the ink collection pack 122. The load cell 126 can be included.

  The ink collection pack 122 may be formed in a multilayer structure so that air is blocked.

  The second load cell 126 is a device for measuring the weight of ink in the ink collection pack 122. In the present embodiment, the load cell is described as an example, but the present invention is limited to this. Needless to say, any apparatus capable of measuring the weight of normal ink can be used.

  The ink jet print head 130 is an apparatus that has an ink flow path formed therein, and ejects ink to nozzles through a change in pressure or volume in the ink flow path by driving an actuator (not shown). Since the specific configuration is substantially the same as that of a general ink jet print head, detailed description will be omitted.

  Ink supplied from the ink supply unit 110 is supplied to the ink jet print head 130 via the sub tank 134, printing is performed by the ink jet print head 130, and when printing is completed, ink not ejected from the ink jet print head 130 is sub tank. The ink is transferred to the ink recovery unit 120 via 134.

  The ink jet print head 130 may include a filter unit 136 on the ink supply path side of the sub tank 134 so as to prevent foreign matter from entering the inside of the ink jet print head 130 and clogging the nozzles. The filter unit 136 may have a mesh shape in which a gap smaller than the diameter of a nozzle (not shown) of the inkjet print head 130 is formed.

  Further, the inkjet print head 130 includes the temperature sensor 132, so that the temperature of ink ejected through the inkjet print head 130 can be controlled.

  The ink supply unit 110, the ink recovery unit 120, and the ink jet print head 130 are connected by a pipe. By providing a valve in the pipe and opening and closing the valve, an ink supply path, an ink recovery path, and an ink return path are provided. Form.

  The pipe forms a first pipe 150 and a second pipe 152 that form an ink supply path, a fourth pipe 154 and a fifth pipe 156 that form an ink recovery path, and a part of an ink return path. And a third piping 153 to be included. These pipes can be formed in a multilayer structure so that air is blocked.

  The valve includes a first valve 142 provided between a first branch point 151 branched from the first pipe 150 and a second branch point 155 branched from the fifth pipe 156; A second valve 144 provided in the second pipe 152 and a third valve 146 provided in the fourth pipe 154 can be included.

  The control unit adjusts the pressures of the ink supply unit 110 and the ink recovery unit 120 to perform ink supply, ink recovery, and ink return, and adjusts the pressure in the sub tank 134 of the inkjet print head 130 to adjust the pressure of the ink jet print head. A pressure controller may be included to remove gas from inside 130.

  Specifically, the pressure control unit includes a first pressure adjustment unit 118 that adjusts the pressure P1 of the ink supply unit 110, a second pressure adjustment unit 128 that adjusts the pressure P2 of the ink recovery unit 120, and an inkjet. And a third pressure adjusting unit 138 for adjusting the pressure of the print head 130.

  The first to third pressure adjusting units 118, 128, and 138 reduce the pressure in the ink supply unit 110, the ink collection unit 120, and the ink jet print head 130 according to the fine characteristics of ink discharge, particularly a pressure below atmospheric pressure. It is preferable that the device is a negative pressure state.

  In the present embodiment, the ink circulation device 100 circulates ink according to the pressure difference between the ink supply unit 110 and the ink recovery unit 120, and the control unit changes the pressure of the ink supply unit 110 to the ink recovery unit 120. (P1> P2) to supply ink to the ink jet print head 130, and the ink recovery unit 120 to have a pressure higher than the pressure of the ink supply unit 110 (P1 <P2) to supply ink from the ink recovery unit 120. Ink can be returned to the unit 110.

  The control unit can include a valve control unit (not shown), and the valve control unit closes the first valve 142 provided in the third pipe 153 when supplying ink to the inkjet print head 130. When the second valve 144 provided in the second pipe 152 and the third valve 146 provided in the fourth pipe 154 are opened and the ink is returned from the ink recovery unit 120 to the ink supply unit 110, the second valve 144 is provided. The second valve 144 provided in the pipe 152 and the third valve 146 provided in the fourth pipe 154 can be closed, and the first valve 142 provided in the third pipe 153 can be opened.

  Specifically, when the second pressure adjustment unit 128 sets the pressure of the ink recovery unit 120 to a negative pressure state, the pressure of the ink supply unit 110 becomes higher than the pressure of the ink recovery unit 120 (P1> P2). The valve controller closes the first valve 142 and opens the second valve 144 and the third valve 146, whereby ink is supplied from the ink supply unit 110 to the ink jet print head 130 via the ink supply path. Ink that has not been ejected from the print head 130 can be collected by the ink collection unit 120 through the ink collection path.

  When the ink is restored, if the first pressure adjusting unit 118 sets the pressure of the ink supply unit 110 to a negative pressure state, the pressure of the ink recovery unit 120 becomes higher than the pressure of the ink supply unit 110 (P1 <P2). When the valve control unit opens the first valve 142 and closes the second valve 144 and the third valve 146, the ink may be returned from the ink recovery unit 120 to the ink supply unit 110 via the ink return path. it can.

The control unit can determine ink supply and ink return based on the ink weights of the ink supply unit 110 and the ink recovery unit 120. Specifically, the sum of the ink weight (W ₁ ) measured by the first load cell 116 of the ink supply unit 110 and the ink weight (W ₂ ) measured by the second load cell 126 of the ink recovery unit 120. If (W _t ) is within a preset ink flow range and W ₁ is greater than or equal to the minimum supply weight, ink supply and ink recovery are performed, W _t is within the ink flow range and W ₁ Is less than the minimum supply weight, the ink recovery from the ink recovery unit 120 to the ink supply unit 110 is performed.

  The third pressure adjusting unit 138 can remove the gas in the inkjet print head 130 by setting the pressure of the sub tank 134 to a negative pressure state while printing the inkjet print head 130.

  The control unit may include a temperature control unit, and when the temperature measured by the temperature sensor 132 of the ink jet print head 130 is equal to or lower than a preset temperature, the heater of the ink supply unit 110 ( By actuating (not shown), the temperature of the ink supplied from the ink supply unit 110 can be raised.

Further, the control unit alarms that ink is filled when the ink weight of the ink supply unit 110 and the ink recovery unit 210 measured by the first and second load cells 116 and 126 is equal to or less than a preset weight. Part (not shown). That is, the alarm unit includes an ink weight (W ₁ ) measured by the first load cell 116 of the ink supply unit 110 and an ink weight (W ₂ ) measured by the second load cell 126 of the ink recovery unit 120. If the weight is less than the preset minimum weight, the ink transfer such as ink supply, recovery, and return is terminated, and an ink filling alarm is issued.

  Hereinafter, the ink circulation method will be described in detail with reference to FIGS.

  When the second pressure adjustment unit 128 sets the pressure of the ink recovery unit 120 to a negative pressure state for supplying ink, the pressure of the ink supply unit 110 becomes higher than the pressure of the ink recovery unit 120 (P1> P2). When the valve controller closes the first valve 142 and opens the second valve 144 and the third valve 146, the ink is supplied from the ink supply pack 112 to the first pipe 150 that is the ink supply path (A1 → A2). And is supplied to the sub tank 134 of the inkjet print head 130 via the second pipe 152.

  The ink that has not been ejected from the inkjet print head 130 is stored in the sub tank 134, and the ink is collected through the fourth pipe 154 and the fifth pipe 156 that are ink collection paths (A 3 → A 4). Into the ink collection pack 122.

  As the ink in the ink supply pack 112 flows into the ink collection pack 122 via the inkjet print head 130, the pressure of the ink supply unit 110 decreases and the pressure of the ink recovery unit 120 increases.

  When the ink is almost transferred to the ink supply pack 112, the control unit is switched to the ink return mode, and when the first pressure adjusting unit 118 puts the ink supply unit 110 into a negative pressure state, the pressure of the ink recovery unit 120 is changed to the ink supply mode. The pressure becomes higher than the pressure of the supply unit 110 (P1 <P2). At this time, the valve control unit opens the first valve 142 and closes the second valve 144 and the third valve 146, so that the inside of the ink collection pack 122 is increased. Ink is moved into the ink supply pack 112 of the ink supply unit 110 via the fifth pipe 156, the third pipe 153, and the first pipe 150 which are ink return paths (B 1 → B 2 → B 3 → B 4). .

On the other hand, when the ink weight of the ink supply unit 110 and the ink recovery unit 210 measured by the first and second load cells 116 and 126 is equal to or less than a preset weight, the control unit ends the ink transfer, The alarm unit can warn of ink filling. That is, the ink weight (W ₁ ) measured by the first load cell 116 of the ink supply unit 110 and the ink weight (W ₂ ) measured by the second load cell 126 of the ink recovery unit 120 are set in advance. If the weight is less than the minimum weight, the control unit finishes ink transfer such as ink supply, recovery, and return, and the alarm unit warns ink filling.

  FIG. 4 schematically shows an ink circulation device according to the second embodiment of the present invention, and FIG. 5 shows an ink supply path and an ink recovery path in the ink circulation device according to the second embodiment of the present invention. FIG. 6 is a view showing an ink return path in the ink circulation device according to the second embodiment of the present invention.

  The ink circulation device according to the second embodiment of the present invention shown in FIGS. 4 to 6 controls the pressures of the ink supply unit and the ink recovery unit based on the height difference between the ink supply unit and the ink recovery unit. Since the other configurations are the same as those of the ink circulation device according to the first embodiment of the present invention shown in FIGS. 1 to 3, a detailed description thereof will be omitted, and the following description is omitted. The difference will be mainly described.

  4 to 6, the ink circulation device 200 according to the present embodiment may include an ink supply unit 210, an ink recovery unit 220, and a control unit.

  The ink supply unit 210 supplies ink to the inkjet print head 230 along the ink supply path, and includes an ink supply pack 212 filled with sufficiently degassed ink, and the ink supply pack 212. Vibrating means 214 that vibrates ink and a first load cell 216 that measures the ink weight of the ink supply pack 212 can be included.

  The ink collection unit 220 collects ink that has not been ejected from the inkjet print head 230, and includes an ink collection pack 222 that is filled with the collected ink, and a second ink that measures the ink weight of the ink collection pack 222. Load cell 226.

  The control unit adjusts the pressure of the ink supply unit 210 and the ink recovery unit 220 to adjust the pressure in the sub tank 232 of the ink jet print head 230 and the pressure control unit 260 that performs ink supply, ink recovery, and ink recovery. And a degassing module 238 that adjusts to remove gas within the inkjet printhead 130.

  The pressure control unit 260 adjusts the heights of the ink supply unit 210 and the ink recovery unit 220 at the time of ink supply and ink recovery, thereby adjusting the pressure difference between the ink supply unit 210 and the ink recovery unit 220. Can be generated. That is, when ink is supplied, the height of the ink supply unit 210 can be made higher than the height of the ink collection unit 220, and when the ink is restored, the height of the ink collection unit 220 can be made higher than the height of the ink supply unit 210.

  For this, the pressure controller 260 may include means for raising and lowering the ink supply unit 210 and the ink recovery unit 220.

  As described above, in the present embodiment, the pressure controller 260 adjusts the pressure between the ink supply unit 210 and the ink recovery unit 220 by adjusting the heights of the ink supply unit 210 and the ink recovery unit 220. Unlike the first embodiment of the present invention, the first and second pressure adjusting units that make the pressures of the ink supply unit and the ink recovery unit negative in the first embodiment are not required separately. .

  The pressure control unit 260 can determine ink supply and ink return according to the ink weights of the ink supply unit 210 and the ink recovery unit 220 as in the first embodiment.

  Hereinafter, the ink circulation method according to the present embodiment will be described in detail with reference to FIGS. 5 and 6.

  When the pressure control unit 260 raises the ink supply unit 210 and lowers the ink recovery unit 220 to supply ink, the pressure of the ink supply unit 210 becomes higher than the pressure of the ink recovery unit 220 (P1> P2). At this time, when the valve controller closes the first valve 242 and opens the second valve 244 and the third valve 246, the ink is supplied from the ink supply pack 212 to the ink supply path (C 1 → C 2 → C 3). The ink is supplied to the sub tank 232 of the inkjet print head 230 through the pipe 250 and the second pipe 252.

  The ink that has not been ejected from the inkjet print head 230 is stored in the sub tank 232, and the ink is collected via the fourth pipe 254 and the fifth pipe 256 that are ink collection paths (C 4 → C 5 → C 6). It flows into the ink collection pack 222 of the section 220.

  When the ink is almost transferred to the ink supply pack 212, the control unit switches to the ink return mode, and when the pressure control unit 260 lowers the ink supply unit 210 and raises the ink recovery unit 220, the pressure of the ink recovery unit 220 is changed. Becomes higher than the pressure of the ink supply unit 210 (P1 <P2). At this time, the valve control unit opens the first valve 242 and closes the second valve 244 and the third valve 246, so that the ink collection pack 222 is closed. The ink supply pack of the ink supply unit 210 passes through the fifth pipe 256, the third pipe 253, and the first pipe 250 in which the ink in the ink is the ink return path (D1-> D2-> D3-> D4-> D5-> D6). Moved into 212.

  FIG. 7 is a drawing schematically showing an ink circulation device according to a third embodiment of the present invention.

  The ink circulation device according to the third embodiment of the present invention shown in FIG. 7 is provided with a large number of ink jet print heads between the ink supply unit and the ink recovery unit. Is the same as the ink circulation device according to the first embodiment of the present invention shown in FIGS. 1 to 3, and detailed description thereof will be omitted, and the difference will be mainly described below. And

  Referring to FIG. 7, an ink circulation device 300 according to the third embodiment of the present invention may include an ink supply unit 310, an ink recovery unit 320, and a control unit.

  The ink supply unit 310 supplies ink to each of the inkjet print heads 330a to 330d along the ink supply path, and includes an ink supply pack 312 filled with sufficiently degassed ink, and the ink supply. Vibrating means 314 that vibrates the ink of the pack 312 and a first load cell 316 that measures the ink weight of the ink supply pack 312 can be included.

  The ink collection unit 320 collects ink that has not been ejected from the inkjet print heads 330a to 330d, and measures the ink collection pack 322 filled with the collected ink and the ink weight of the ink collection pack 322. A second load cell 326 may be included.

  In this embodiment, the inkjet print heads 330a to 330d are configured by four, and can be configured by first to fourth inkjet print heads 330a to 330d. Each of the first to fourth inkjet print heads 330a to 330d has an ink flow path formed therein, and can eject ink of four colors. For example, the first inkjet print head 330a is black ink, the second inkjet print head 330b is cyan ink, the third inkjet print head 330c is magenta ink, and the fourth inkjet print head 330d is yellow. Ink can be ejected.

  At this time, the ink supply unit 310 and the ink recovery unit 320 may include ink packs corresponding to the respective hues.

  In the present embodiment, the ink jet print head composed of four ink jet print heads is illustrated and described. However, the present invention is not limited to this, and a large number of ink jet print heads may be used depending on the combination of ejected hues. Inkjet printheads can be provided.

  The first to fourth ink jet print heads 330a to 330d are connected to the ink supply unit 310 and the ink recovery unit 320 via respective pipes, and each pipe is provided with a valve for opening and closing the ink flow path. ing.

  The control unit adjusts the pressures in the ink supply unit 310 and the ink recovery unit 320 to perform ink supply, ink recovery, and ink recovery, and adjusts the pressure in the sub tank 334 of the inkjet print heads 330a to 330d to perform inkjet. A pressure controller that removes gas from the print heads 330a to 330d may be included.

  Specifically, the pressure control unit includes a first pressure adjustment unit 318 that adjusts the pressure P1 of the ink supply unit 310, a second pressure adjustment unit 328 that adjusts the pressure P2 of the ink recovery unit 320, and an inkjet. And a third pressure adjusting unit that adjusts the pressure of the print heads 330a to 330d.

  On the other hand, when the pressure control is performed by adjusting the height of the ink supply unit and the ink recovery unit as in the second embodiment of the present invention, the first and second pressure adjustment units 318 and 328 are Not needed separately.

  The third pressure adjusting unit adjusts the pressure in the sub tanks of the first to fourth ink jet print heads 330a to 330d to remove the gas inside the ink jet print head. The first degassing module 338a connected to the sub tank of the print head 330a, the second degas module 338b connected to the sub tank of the second inkjet print head 330b, and the sub tank of the third inkjet print head 330c. A third deaeration module 338c connected to the sub-tank of the fourth inkjet print head 330d may be included.

  In the present embodiment, the ink circulation path by the ink circulation device 300 will be described in detail as follows.

  At the time of ink supply, the control unit makes the pressure of the ink supply unit 310 higher than the pressure of the ink recovery unit 320 (P1> P2), closes the first valve 342 provided in the third pipe 353, and closes the second pipe. By opening the second valves 344a to 344d provided in the branch lines 352a to 352d and the third valves 346a to 346d provided in the branch lines 354a to 354d of the fourth pipe, the first pipe 350, Ink is supplied to the first to fourth ink jet print heads 330a to 330d via the second pipe 352 and the branch lines 352a to 352d of the second pipe.

  Ink that has not been ejected by the first to fourth inkjet print heads 330a to 330d passes through the branch lines 354a to 354d, the fourth pipe 354, and the fifth pipe 356 of the fourth pipe to the ink recovery unit 320. Collected.

  When the ink is restored, the control unit makes the pressure of the ink recovery unit 320 higher than the pressure of the ink supply unit 310 (P1 <P2), opens the first valve 342 provided in the third pipe 353, and sets the second pipe. By closing the second valves 344a to 344d provided on the branch lines 352a to 352d and the third valves 346a to 346d provided on the branch lines 354a to 354d of the fourth pipe, the fifth pipe 356, Ink can be returned from the ink recovery unit 320 to the ink supply unit 310 via the third pipe 353 and the first pipe 350.

  The preferred embodiments of the present invention have been described in detail above, but these are merely examples, and various modifications and other equivalent embodiments can be made by those having ordinary knowledge in the field. It is clear that it can be conceived. Accordingly, the scope of technical protection of the present invention should be determined by the appended claims.

DESCRIPTION OF SYMBOLS 100 Ink circulation apparatus 110 Ink supply part 112 Ink supply pack 116 1st load cell 120 Ink collection part 122 Ink collection pack 126 2nd load cell 130 Inkjet print head

Claims (15)

An ink supply for containing ink and supplying ink to an inkjet printhead;
An ink supply path connecting the inkjet print head and the ink supply unit;
An ink collecting section for collecting and storing ink that has not been ejected from the inkjet print head;
An ink recovery path connecting the ink jet print head and the ink recovery unit;
An ink return path for returning the ink of the ink recovery unit to the ink supply unit;
When supplying ink to the ink jet print head, the internal pressure of the ink supply unit is made higher than the internal pressure of the ink recovery unit, the first valve provided in the ink return path is closed, and the ink supply path is closed. The second valve provided and the third valve provided in the ink recovery path are opened, and when the ink returns from the ink recovery unit to the ink supply unit, the pressure inside the ink recovery unit is supplied to the ink supply unit. And a controller that opens the first valve and closes the second valve and the third valve.   2. The ink circulation device according to claim 1, wherein the control unit sets the pressure of the ink recovery unit to a negative pressure state when the ink is supplied, and sets the pressure of the ink supply unit to a negative pressure state when the ink is restored.   The control unit makes the height of the ink supply unit higher than the height of the ink recovery unit when supplying the ink, and makes the height of the ink recovery unit higher than the height of the ink supply unit when returning the ink. The ink circulation device according to claim 1.   The ink circulation device according to any one of claims 1 to 3, further comprising a filter portion in which a gap smaller than a diameter of a nozzle of the ink jet print head is formed on the ink jet print head side of the ink supply path.   The ink circulation device according to any one of claims 1 to 4, wherein the ink supply unit includes an ink pack filled with degassed ink.   The said ink supply part, the said ink collection | recovery part, the said ink supply path, the said ink collection path, and the said ink return path are formed in multilayer structure so that air may be interrupted | blocked. The ink circulation device according to item.   The ink circulation device according to any one of claims 1 to 6, wherein the ink supply unit includes a vibration unit that vibrates the ink supply unit so as to prevent ink settling. The ink supply unit and the ink recovery unit include a load cell for measuring ink weight,
8. The ink circulation device according to claim 1, wherein the control unit determines ink supply and ink return based on ink weights of the ink supply unit and the ink recovery unit measured by the load cell. 9.   The ink circulation device according to claim 8, wherein the control unit warns ink filling when the ink weight of the ink supply unit and the ink recovery unit measured by the load cell is equal to or less than a preset weight. An ink circulation device according to any one of claims 1 to 9,
An ink jet print head which is supplied with ink from the ink circulation device and discharges the ink;
A sub tank for storing ink between the ink jet print head and the ink supply path and the ink recovery path;
Inkjet printer including.   The ink jet printer according to claim 10, wherein the control unit places the sub tank in a negative pressure state so as to remove gas in the ink jet print head when the ink is supplied. When the pressure inside the ink supply unit that contains ink and supplies ink to the inkjet print head becomes higher than the pressure inside the ink collection unit that collects and stores ink that has not been ejected from the inkjet print head, Close the first valve of the ink return path for returning the ink in the collecting section to the ink supply section, and open the second valve of the ink supply path that connects the ink jet print head and the ink supply section to supply the ink. Supplying ink to the inkjet printhead through a path;
When printing by the inkjet print head is completed, a third valve of an ink recovery path that connects the inkjet print head and the ink recovery section is opened, and ink that has not been ejected from the inkjet print head is removed from the ink recovery path. Recovering to the ink recovery unit via
When the pressure inside the ink recovery section becomes higher than the pressure inside the ink supply section, the second valve of the ink supply path and the third valve of the ink recovery path are closed, and the pressure of the ink return path is increased. Opening the first valve and returning the ink of the ink recovery unit to the ink supply unit via the ink return path.   The ink circulation method according to claim 12, wherein the pressure adjustment of the ink supply unit and the ink recovery unit is performed by setting one of the ink supply unit and the ink recovery unit to a negative pressure state.   The ink circulation method according to claim 12, wherein the pressure adjustment of the ink supply unit and the ink recovery unit is performed by adjusting the height of the ink supply unit and the ink recovery unit.   The ink circulation method according to any one of claims 12 to 14, further comprising a step of alarming ink filling when an ink weight of the ink supply unit and the ink recovery unit is equal to or less than a preset weight.

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