JP2005138552A - Ink jet type printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet type printer for controlling waste of ink in a relay tank. <P>SOLUTION: A pressuring/evacuating valve 113 capable of being charged to a stage for feeding air into cases 122a-122d and a stage for evacuating the cases 122a-122d are provided in an air passage 112 between an air pump 111 and the cases 122a-122d storing ink packs 121a-121d sealing ink. Then, air is fed into the cases 122a-122d by switching the valve 113 to pressurize the insides of the cases 122a-122d to reduce the volumes of the cases 122a-122d by changing over the pressurizing/evacuating valve 113. The ink inside it is press-fed to relay tanks 130a-130d. Air in the cases 122a-122d is sucked by changing over the valve 113 to reduce the pressure inside the cases 122a-122d to increase the volume of the ink packs 121a-121d. The ink in the relay tanks 130a-130d is made to flow backward in the ink pack 121a to 121d. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink jet printer including a relay tank that supplies ink to a print head and an ink cartridge that supplies ink to the relay tank.

  An ink jet printer that performs printing by discharging liquid ink onto a sheet includes a print head that is disposed so as to face the sheet, and an ink cartridge that stores ink used for printing. What is comprised so that attachment or detachment is possible is common. In addition, a large-sized printer for business use needs to be provided with a large-capacity ink cartridge. Therefore, in such a printer, the ink stored in the ink cartridge is temporarily stored in the relay tank by the ink supply device so that a large-capacity ink cartridge can be arranged regardless of the water head difference between the print head and the ink cartridge. There are some which supply the ink in the relay tank as appropriate to the print head (for example, see Patent Document 1). Also, by providing the relay tank, it is possible to replace the ink cartridge without interrupting the printing operation even when the ink in the ink cartridge becomes empty.

  Here, a schematic configuration of the ink supply device 500 of the printer is shown in FIG. The ink cartridges 520a to 520d include ink packs 521a to 521d into which yellow (yellow), magenta (red violet), cyan (blue green), and black ink are respectively injected, and cases 522a to 521d that store the ink packs 521a to 521d. 522d. Note that the ink in the ink packs 521a to 521d is deaerated so as not to impair the image quality of printing due to the generation of bubbles. Then, the air discharged from the air pump 511 is supplied into the cases 522a to 522d through the air flow path 512, whereby the inside of the cases 522a to 522d is pressurized, and the ink in the ink packs 521a to 521d is relayed to the relay tank. It is pumped to 540a-540d. Here, between the air pump 511 and the cases 522a to 522d, the pressure inside the cases 522a to 522d can be switched between the open state and the pressurized state, and the pressure inside the cases 522a to 522d is constant. And a pressure adjusting unit 514 for maintaining the temperature.

  Further, ink supply valves 530a to 530d that can switch between an ink supply state and a supply cutoff state are arranged between the ink cartridges 520a to 520d and the relay tanks 540a to 540d, respectively. The ink supply valves 530a to 530d are switched from the ink supply state to the supply cutoff state when the sensors 541a to 541d of the relay tanks 540a to 540d detect that the relay tanks 540a to 540d are filled with ink.

JP 2001-293882 A

  When such a printer is moved to a remote place, the type of ink to be used is changed, or when the printer is used again after a long period of use, it is necessary to empty the relay tanks 540a to 540d. Therefore, in such a case, the ink in the relay tanks 540a to 540d is discharged by the ink suction devices 560a to 560d having the caps 561a to 561d attached to the print heads 550a to 550d and the ink suction air pumps 562a to 562d. There must be. Thus, when discharging the ink in the relay tanks 540a to 540d, there arises a problem that a large amount of ink is wasted.

  Therefore, an object of the present invention is to provide an ink jet printer that can suppress waste of ink.

Means and effects for solving the problems

  An ink jet printer according to the present invention prints an ink pack placement unit in which an ink pack filled with ink is placed, a relay tank that stores ink supplied from the ink pack, and ink supplied from the relay tank A print head that discharges the ink to the medium; and an ink recovery mechanism that allows the ink in the relay tank to flow back to the ink pack.

  According to this configuration, when it is necessary to empty the relay tank, the ink in the relay tank can be collected in the ink pack. Therefore, the amount of ink discharged from the print head can be reduced. As a result, waste of ink can be suppressed.

  In the ink jet printer according to the aspect of the invention, the ink pack placement unit includes an airtight case in which the ink pack can be stored, and the volume of the ink pack is variable according to the atmospheric pressure in the airtight case, The ink recovery mechanism may include an air pump and an air flow path that connects the air pump and the airtight case so that air is discharged from the airtight case.

  According to this configuration, by discharging the air in the airtight case and lowering the atmospheric pressure in the airtight case, the ink in the relay tank can be easily backflowed into the ink pack.

  In the ink jet printer according to the present invention, the air is interposed in the air flow path, the air is discharged from the airtight case through the air flow path, and the air is supplied into the airtight case through the air flow path. There may be further provided a directional switching valve that can be selectively switched to any one of a state in which the airtight case is opened and a state in which the airtight case is opened to the atmosphere.

  According to this configuration, the ink in the ink pack can be supplied to the relay tank by one air pump, and the ink in the relay tank can flow back to the ink pack. Therefore, the arrangement space of the air pump can be reduced to reduce the size of the ink jet printer, and the manufacturing cost can be reduced. In addition, since one directional switching valve can switch between a state in which the ink in the ink pack is supplied to the relay tank and a state in which the ink in the relay tank flows back to the ink pack, the space for arranging the directional switching valve is reduced. By reducing the size, the size of the ink jet printer can be reduced.

  In the ink jet printer of the present invention, when supplying the ink in the ink pack to the relay tank, the direction switching valve is switched to a state in which air is supplied to the airtight case via the air flow path, When the ink in the relay tank is caused to flow back to the ink pack, the direction switching valve may further include a switching control unit that switches the air to the state in which air is discharged from the airtight case through the air flow path. Good.

  According to this configuration, the state of supplying the ink in the ink pack to the relay tank and the state of causing the ink in the relay tank to flow back to the ink pack can be easily switched by the switching control means.

  In the ink jet printer of the present invention, the air flow path has one end connected to the airtight case, the other end connected to the air discharge port of the air pump, and one end connected to the airtight case. A second air flow path connected at the other end to the air suction port of the air pump, and connected to the first air flow path at a first branch point. A third air flow path connecting the first air flow path and the outside, and a second air flow path connected to the second air flow path at a second branch point, and connecting the second air flow path to the outside. A flow path, interposed in the first air flow path between the first branch point and the airtight case, and from the air pump through the first air flow path to the airtight case The air is supplied to the inside, and the first air flow path is closed. A first directional control valve that is selectively switched to any one of the states, and the second air flow path between the second branch point and the airtight case, the airtight case A second directional control valve that is selectively switched to one of a state in which air is discharged through the second air flow path and a state in which the second air flow path is closed; 3 in the state where the air in the first air passage is released to the outside and the state where the third air passage is closed. A third direction switching valve to be switched; and a state in which the air in the second air flow path is discharged to the outside, and the fourth air flow path. A fourth directional control valve that can be selectively switched to any of the closed states It may be e.

  According to this configuration, the ink in the ink pack can be supplied to the relay tank by one air pump, and the ink in the relay tank can flow back to the ink pack. Therefore, the arrangement space of the air pump can be reduced to reduce the size of the ink jet printer, and the manufacturing cost can be reduced. Further, the first to fourth direction switching valves of a relatively simple mechanism can switch between a state in which the ink in the ink pack is supplied to the relay tank and a state in which the ink in the relay tank is caused to flow back to the ink pack. it can. Accordingly, the manufacturing cost of the ink jet printer can be reduced.

  In the ink jet printer of the present invention, when the ink in the ink pack is supplied to the relay tank, the first direction switching valve is moved from the air pump to the airtight case through the first air flow path. In a state where air is supplied, the second direction switching valve is closed in the second air flow path, the third direction switching valve is closed in the state where the third air flow path is closed, When the fourth direction switching valve is switched to a state in which the air in the second air flow path is discharged to the outside, and the ink in the relay tank flows back to the ink pack, The directional switching valve is in a state in which the first air flow path is closed, and the second directional switching valve is in a state in which air is discharged from the airtight case through the second air flow path. 3 direction switching valve, the first air flow A state in which the air of the inner is discharged to the outside, the fourth directional control valve, the fourth state of closing the air flow path may further comprise a switching control means for switching, respectively.

  According to this configuration, the state of supplying the ink in the ink pack to the relay tank and the state of causing the ink in the relay tank to flow back to the ink pack can be easily switched by the switching control means.

  In the ink jet printer of the present invention, it is preferable that a plurality of the print head, the relay tank, and the airtight case are provided, and the air pump is common to the plurality of airtight cases.

  According to this configuration, the ink in the plurality of ink packs can be supplied to the relay tank by one air pump, and the ink in the plurality of relay tanks can flow back to the ink pack. Accordingly, since it is not necessary to provide an air pump for each of the plurality of ink packs, it is possible to reduce the size of the ink jet printer and reduce the manufacturing cost.

  In the ink jet printer of the present invention, the ink is interposed in a first ink flow path that connects the print head and the relay tank, and ink passes from the print head to the relay tank via the first ink flow path. It is preferable to further include a check valve for preventing backflow.

  According to this configuration, ink mixed with foreign matters such as air existing in the vicinity of the print head in the first ink flow path does not flow back into the relay tank.

  In the ink jet printer according to the present invention, the sensor is disposed in the second ink flow path that connects the sensor that detects the amount of ink stored in the relay tank and the relay tank, and the detection result of the sensor. In response to this, an ink supply valve that can open and close the second ink flow path may be further provided.

  According to this configuration, the amount of ink stored in the relay tank can be appropriately maintained.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  First, the configuration of the ink jet printer according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a schematic configuration of an ink jet printer according to the present embodiment. FIG. 2 is a diagram showing a schematic configuration of an ink supply device of the ink jet printer shown in FIG. FIG. 3 is a block diagram showing a control system of the ink jet printer of FIG.

  An ink jet printer 1 shown in FIG. 1 includes an ink supply device 100, an ink jet printing unit 40, a transport roller unit 5, a pressure roller unit 6, a cutting unit 7, and a discharge in a substantially rectangular casing 60. And a roller unit 8. In the housing 60, a long sheet 2 having a winding part 2a wound in a roll shape is disposed, and the winding part 2a of the sheet 2 is rotatable around the axis center. Held on the drum 3. As will be described later, the operation of each part of the ink jet printer 1 is controlled by a controller 50 disposed in the housing 60.

  As shown in FIG. 2, the ink supply device 100 includes a pressure increasing / decreasing unit 110, ink cartridges 120a to 120d, relay tanks 130a to 130d, sensors 131a to 131d, ink inlet / outlet valves 140a to 140d, and check valves. 150a to 150d, and supplies the ink in the ink cartridges 120a to 120d to the print heads 41a to 41d described later. The ink cartridges 120a to 120d and the relay tanks 130a to 130d and the relay tanks 130a to 130d and the print heads 41a to 41d are connected by an ink flow path 160.

  The pressure increasing / decreasing unit 110 is connected to the ink cartridges 120a to 120d. The pressure increasing / decreasing unit 110 includes an air pump 111, a pressure increasing / decreasing valve 113, and a pressure adjusting unit 114. Further, the air flow path 112 connects between the air pump 111 and the pressure increasing / decreasing valve 113, between the pressure increasing / decreasing valve 113 and the pressure adjusting unit 114, and between the pressure adjusting unit 114 and each of the ink cartridges 120a to 120d. ing.

  The air pump 111 has a suction port 111a for sucking air and a discharge port 111b for discharging air. The pressure increasing / decreasing valve 113 is connected to the cases 122a to 122d via the suction port 111a, the discharge port 111b, and the pressure adjusting unit 114 of the air pump 111. The pressure increasing / decreasing valve 113 includes an open state to the atmosphere (the state shown in FIG. 2), a pressurized state in which air discharged from the discharge port 111b is discharged to the cases 122a to 122d via the pressure increasing / decreasing valve 113, and a case It is possible to switch between a reduced pressure state in which the air on the 122a to 122d side is sucked from the suction port 111a via the pressure increasing / decreasing valve 113.

  The pressure adjustment unit 114 is controlled by the controller 50. When the air pressure in the pressure adjustment unit 114 pressurized by the air pump 111 reaches a predetermined value or more, a pressure release valve (not shown) included in the pressure adjustment unit 114 is shown. ) Is opened, the pressure in the pressure adjusting unit 114 is released by an amount exceeding the predetermined value, and the air pressure in each of the cases 122a to 122d can be maintained within a predetermined range.

  All of the ink cartridges 120 a, 120 b, 120 c, and 120 d are configured to be detachable from the ink jet printer 1 so as to be connected to the pressurizing / reducing unit 110. Each of the ink cartridges 120a to 120d includes ink packs 121a, 121b, 121c, and 121d and cases 122a, 122b, 122c, and 122d that store them. Yellow (yellow), magenta (red purple), cyan (blue green), and black degassed ink are injected into the ink packs 121a to 121d, respectively. The cases 122a to 122d are all configured in an airtight state.

  Accordingly, when air is supplied into the cases 122a to 122d by the air pump 111 and the insides of the cases 122a to 122d are pressurized, the volumes of the ink packs 121a to 121d are reduced and sealed in the inside. The ink is pumped to the relay tanks 130a to 130d. Further, when the air in the cases 122a to 122d is discharged by the air pump 111 and the inside of the cases 122a to 122d is depressurized, the volumes of the ink packs 121a to 121d are increased, and the inside of the relay tanks 130a to 130d is increased. Ink is collected in each of the ink packs 121a to 121d.

  The relay tanks 130a, 130b, 130c, and 130d are disposed between the print heads 41a to 41d and the ink packs 121a to 121d, respectively, and store the ink fed from the ink packs 121a to 121d. The relay tanks 130a to 130d are all arranged at a position higher than the print heads 41a to 41d, and the ink in the relay tanks 130a to 130d is appropriately supplied to the print heads 41a to 41d due to a water head difference. The ink storage amounts in the relay tanks 130a to 130d are detected by the sensors 131a to 131d, respectively. The sensors 131a to 131d are each connected to the controller 50.

  The ink inlet / outlet valves 140a, 140b, 140c, and 140d are respectively interposed in the ink flow paths 160 between the ink packs 121a to 121d and the relay tanks 130a to 130d, and the ink packs 121a to 121d and the relay tanks 130a to 130d The state in which the ink flows between the two and the state in which the ink flow is blocked are switched based on the detection signals from the sensors 131a to 131d. When the ink in the ink packs 121a to 121d is pressure-fed to the relay tanks 130a to 130d, or when the ink in the relay tanks 130a to 130d is collected in the ink packs 121a to 121d, the ink inlet / outlet valves 140a to 140d are opened. Let the ink flow state. In addition, when the sensors 131a to 131d detect that the relay tanks 130a to 130d are filled with ink, the ink inlet / outlet valves 140a to 140d are closed to make the ink flow cut-off state.

  The check valves 150a, 150b, 150c, and 150d are respectively interposed in the ink flow paths 160 between the relay tanks 130a to 130d and the print heads 41a to 41d, and ink mixed with air from the print heads 41a to 41d. It is possible to prevent foreign matters such as dust and the like from flowing back into the relay tanks 130a to 130d. Therefore, air and foreign matter are hardly mixed into the ink in the relay tanks 130a to 130d.

  The ink jet printing unit 40 includes print heads 41 a to 41 d, a suction fan 42, and a transport table 43. Each of the print heads 41 a to 41 d has a large number of discharge nozzles (which can discharge yellow, yellow, magenta, magenta, cyan, and black color inks supplied from the ink supply apparatus 100. (Not shown). The print heads 41 a to 41 d can reciprocate in a direction perpendicular to the conveyance direction of the paper 2. Accordingly, the print heads 41 a to 41 d reciprocate in the direction perpendicular to the transport direction of the paper 2 toward the front surface (upper surface in FIG. 1) of the transported paper 2 based on a signal from the controller 50. A desired color image can be printed by ejecting the color ink from each of a number of ejection nozzles.

  The ink jet printing unit 40 ejects liquid ink from the nozzles for each dot and prints on the paper 2 and adopts any one of the piezo jet method, the thermal jet method, and other methods. Also good.

  Further, the suction fan 42 is disposed at a position facing the print heads 41 a to 41 d across the conveyance path of the paper 2, and is located on the conveyance table 43 through an opening (not shown) formed in the conveyance table 43. The sheet 2 is adsorbed. Accordingly, the sheet 2 facing the print heads 41a to 41d is attracted to the suction fan 42 disposed on the back surface (the lower surface in FIG. 1) side of the sheet 2 and is conveyed in close contact with the conveyance table 43. The distance from 41a to 41d is constant. This is to suppress the occurrence of printing defects due to a change in the distance from the print heads 41a to 41d when a part of the paper 2 is greatly separated from the transport table 43 when the paper 2 is curled. It is.

  The transport roller unit 5 is a pair of drive rollers driven by a motor 25 controlled by a controller 50, and is for unwinding the paper 2 from the winding part 2 a and supplying it to the ink jet printing unit 40. That is, the transport roller unit 5 unwinds the paper 2 from the winding unit 2a and transports the paper 2 to the downstream side, and sequentially passes through the inkjet printing unit 40 and the cutting unit 7.

  The pressure roller unit 6 is for holding the paper 2 conveyed between the ink jet printing unit 40 and the cutting unit 7. Note that the pressure roller 6 is disposed between the ink jet printing unit 40 and the cutting unit 7 so that the image printing by the ink jet printing unit 40 and the cutting of the paper 2 by the cutting unit 7 can be appropriately performed. .

  The cutting unit 7 includes a movable blade 7a disposed on the same side as the print heads 41a to 41d with respect to the paper 2, and a fixed blade 7b disposed so as to face the movable blade 7a with the paper 2 interposed therebetween. ing. Both the movable blade 7 a and the fixed blade 7 b are rectangular blades having a width slightly larger than the width of the paper 2. The movable blade 7a can be moved toward or away from the fixed blade 7b by a motor 27 controlled by the controller 50, and the printed paper 2 that has been transported from the upstream side along the transport path can be removed. By the interaction with the fixed blade 7b, it can be cut along the width direction. By cutting in this way, the printed paper 2 having a predetermined length is divided.

  The discharge roller unit 8 is a pair of drive rollers that are driven by a motor 28 controlled by a controller 50. The discharge roller unit 8 conveys the printed paper 2 that has been cut by the cutting unit 7 and is formed in the housing 60. It discharges from the discharge port 60a.

  As illustrated in FIG. 3, the controller 50 includes an image processing unit 51, a print control unit 52, a conveyance control unit 53, and an ink input / output control unit 54. The image processing unit 51 performs predetermined processing on the image signal supplied from the input interface 30 such as a scanner. A print signal including image data corresponding to an image to be printed and processed by the image processing unit 51 is supplied to the inkjet printing unit 40.

  The print control unit 52 controls the movement timing of the print heads 41a to 41d and the ejection timing of ink from the print heads 41a to 41d. The conveyance control unit 53 is connected to motors 25, 27, and 28, and controls the conveyance timing of the sheet 2 by the conveyance roller unit 5 and the discharge roller unit 8, the cutting timing of the sheet 2 by the cutting unit 7, and the like. The ink inlet / outlet control unit 54 is connected to the pressure increasing / decreasing valve 113 of the ink supply device 100, the pressure adjusting unit 114, and the ink inlet / outlet valves 140a to 140d, and controls the atmospheric pressure in the cases 122a to 122d. Control of switching between the pressurization state and the decompression state of the decompression valve 113 and the timing of opening and closing the ink inlet / outlet valves 140a to 140d are performed.

  Next, the operation of the ink supply apparatus 100 when supplying ink from the ink pack 121a to the relay tank 130a will be described with reference to FIGS. FIG. 4 is a diagram illustrating a state of the ink supply device 100 when ink is supplied from the ink pack 121a to the relay tank 130a. FIG. 5 is a flowchart illustrating an example of a procedure for supplying ink from the ink pack 121a to the relay tank 130a.

  First, it is determined whether or not the ink inlet / outlet valve 140a is in an ink circulation state (step 101). If it is determined that the ink inlet / outlet valve 140a is closed and the ink circulation state is interrupted (step 101: NO), the ink inlet / outlet valve 140a is opened to enter the ink circulation state (step 102). On the other hand, if it is determined that the ink inlet / outlet valve 140a is open and the ink is in a circulation state (step 101: YES), the following processing is performed.

  Next, it is determined whether the pressure increasing / decreasing valve 113 is in a pressurized state (step 103). If it is determined that the pressure increasing / decreasing valve 113 is not in a pressurized state (step 103: NO), the pressure increasing / decreasing valve 113 is set in a pressurized state (step 104). On the other hand, if it is determined that the pressure increasing / decreasing valve 113 is in a pressurized state (step 103: YES), the process proceeds to the following process. The states of the pressure increasing / decreasing valve 113 and the ink inlet / outlet valves 140a to 140d included in the ink supply apparatus 100 at this time are as shown in FIG.

  Next, the air pump 111 is driven (step 105). Then, the air sucked into the suction port 111a of the air pump 111 through the pressure increasing / decreasing valve 113 is discharged from the discharge port 111b of the air pump 111 and supplied to the case 122a through the pressure adjusting unit 114. At this time, the inside of the case 122a is pressurized (step 106). By pressurizing the inside of the case 122a, the volume of the ink pack 121a is reduced, and the ink sealed in the ink pack 121a is discharged out of the ink pack 121a. The ink discharged from the ink pack 121a is supplied to the relay tank 130a through the ink inlet / outlet valve 140a (step 107).

  Next, the operation of the ink supply device 100 when collecting ink from the relay tank 130a into the ink pack 121a will be described with reference to FIGS. FIG. 6 is a diagram illustrating a state of the ink supply device 100 when ink is collected from the relay tank 130a to the ink pack 121a. FIG. 7 is a flowchart showing an example of a procedure for collecting ink from the relay tank 130a into the ink pack 121a.

  First, it is determined whether or not the ink inlet / outlet valve 140a is in an ink circulation state (step 201). If it is determined that the ink inlet / outlet valve 140a is closed and the ink circulation state is interrupted (step 201: NO), the ink inlet / outlet valve 140a is opened and the ink circulation state is established (step 202). On the other hand, if it is determined that the ink inlet / outlet valve 140a is open and the ink distribution state is present (step 201: YES), the following processing is performed.

  Next, it is determined whether the pressure increasing / decreasing valve 113 is in a reduced pressure state (step 203). If it is determined that the pressure increasing / decreasing valve 113 is not in a reduced pressure state (step 203: NO), the pressure increasing / decreasing valve 113 is set in a reduced pressure state (step 204). On the other hand, when it is determined that the pressure increasing / decreasing valve 113 is in a reduced pressure state (step 203: YES), the process proceeds to the following process. At this time, the states of the pressure adjusting valve 113 and the ink inlet / outlet valves 140a to 140d included in the ink supply apparatus 100 are as shown in FIG.

  Next, the air pump 111 is driven (step 205). Then, the air in the case 122 a is sucked into the suction port 111 a of the air pump 111 through the pressure adjusting unit 114 and the pressure increasing / decreasing valve 113. Further, the air discharged from the discharge port 111 b of the air pump 111 is discharged to the outside through the pressure increasing / decreasing valve 113. At this time, the inside of the case 122a is depressurized (step 206). By reducing the pressure in the case 122a, the volume of the ink pack 121a increases, and the ink in the relay tank 130a passes through the ink inlet / outlet valve 140a and is collected in the ink pack 121a (step 207).

  At this time, since the check valve 150a is disposed between the relay tank 130a and the print head 41a, the ink in the ink flow path 160 between the check valve 150a and the print head 41a is transferred to the relay tank 130a. Do not flow backward. Therefore, the ink and foreign matters mixed with the air in the vicinity of the print head 41a are not collected in the ink pack 121a.

  The operation of the ink supply device 100 when supplying ink from the ink packs 121b to 121d to the relay tanks 130b to 130d or when collecting ink from the relay tanks 130b to 130d to the ink packs 121b to 121d is also described above. As described above, since it is the same as the case where ink is supplied from the ink pack 121a to the relay tank 130a or the case where ink is collected from the relay tank 130a to the ink pack 121a, description thereof will be omitted.

  As described above, in the ink jet printer 1 of the present embodiment, the interior of the cases 122a to 122d is supplied by supplying the air discharged from the discharge port 111b into the cases 122a to 122d by switching the pressure increasing / decreasing valve 113. While pressurizing, the inside of cases 122a-122d can be pressure-reduced by attracting the air in cases 122a-122d from the suction port 111a. Accordingly, by pressurizing the inside of the cases 122a to 122d, the volume of the ink packs 121a to 121d can be reduced, and the ink in the ink packs 121a to 121d can be supplied to the relay tanks 130a to 130d, and the cases 122a to 122d can be supplied. By depressurizing the inside, the volumes of the ink packs 121a to 121d can be increased, and the ink in the relay tanks 130a to 130d can be collected in the ink packs 121a to 121d. Therefore, when it is necessary to empty the relay tanks 130a to 130d, for example, when the ink jet printer 1 is moved to a remote place or when the type of ink to be used is changed, the contents of the relay tanks 130a to 130d are changed. The ink can be collected in the ink packs 121a to 121d. As a result, the amount of ink discharged from the print heads 41a to 41d can be reduced, and waste of ink can be suppressed.

  In the ink jet printer 1 of the present embodiment, the air pump 111 is common to the four cases 122a to 122d, and the ink in the ink packs 121a to 121d is supplied to the relay tanks 130a to 130d by the single air pump 111. At the same time, the ink in the relay tanks 130a to 130d can be collected in the ink packs 121a to 121d. Accordingly, it is possible to reduce the size of the ink jet printer 1 and to reduce the manufacturing cost thereof.

  Further, in the ink jet printer 1 of the present embodiment, the check valves 150a to 150d are interposed in the ink flow paths 160 between the relay tanks 130a to 130d and the print heads 41a to 41d, respectively. The ink between 150a to 150d and the print heads 41a to 41d does not flow back to the relay tanks 130a to 130d. Accordingly, it is possible to prevent ink mixed with foreign matters such as air near the print heads 41a to 41d from entering the relay tanks 130a to 130d.

  Further, in the ink jet printer 1 according to the present embodiment, the ink flow path 160 between the ink packs 121a to 121d and the relay tanks 130a to 130d has a state where ink can be circulated and a state where the ink flow is blocked. Ink inlet / outlet valves 140a to 140d that can be switched are respectively interposed. The ink inlet / outlet valves 140a to 140d are opened and closed based on output signals from the sensors 131a to 131d that detect the ink amounts in the relay tanks 130a to 130d. Accordingly, the ink storage amount in the relay tanks 130a to 130d can be properly maintained.

  In the ink jet printer 1 of the present embodiment, the ink in the ink packs 121a to 121d is supplied to the relay tanks 130a to 130d by one air pump 111, and the ink in the relay tanks 130a to 130d is supplied to the ink pack 121a. To 121d. Therefore, the arrangement space of the air pump 111 can be reduced to reduce the size of the ink jet printer 1, and the manufacturing cost can be reduced. In addition, a state in which the ink in the ink packs 121a to 121d is supplied to the relay tanks 130a to 130d by one pressure increasing / decreasing valve 113, and a state in which the ink in the relay tanks 130a to 130d is caused to flow back to the ink packs 121a to 121d. Since the switching can be performed, the arrangement space of the pressure increasing / decreasing valve 113 can be reduced, and the ink jet printer 1 can be reduced in size.

  Next, an ink jet printer provided with an ink supply device according to a second embodiment of the present invention will be described with reference to the drawings.

  The main difference between the configuration of the ink jet printer according to this embodiment and the configuration of the ink jet printer 1 according to the first embodiment is that the ink jet printer 1 shown in FIG. While the pressurization state and the depressurization state in the cases 122a to 122d are switched by using one pressurization / decompression valve 113, the ink supply device 200 of the ink jet printer according to the present embodiment has four pressurization states. The pressure reducing valves 213a to 213d are used to switch between the pressurized state and the reduced pressure state in the cases 222a to 222d. Since other configurations are the same as those of the ink jet printer 1 shown in FIG. 1, detailed description thereof is omitted.

  FIG. 8 is a diagram showing a schematic configuration of the ink supply device 200 of the ink jet printer according to the present embodiment. As shown in FIG. 8, the ink supply device 200 includes pressure increasing / decreasing valves 213 a, 213 b, 213 c, and 213 d that can switch between a state in which the inside of the cases 222 a to 222 d is pressurized and a state in which the pressure is reduced. And between the discharge port 211b of the air pump 211 and the pressure increasing / decreasing valves 213a and 213b, between the suction port 211a of the air pump 211 and the increasing / decreasing valves 213c and 213d, and between the increasing and decreasing valves 213b and 213d and the pressure adjusting unit 214. The pressure adjusting unit 214 and the cases 222a to 222d are connected by an air flow path 212.

  The pressure increasing / decreasing valves 213 a and 213 b are both connected to the discharge port 211 b of the air pump 211. The pressure increasing / decreasing valves 213a and 213b are connected in parallel to each other. Further, the pressure increasing / decreasing valve 213a is opened / closed to open a state communicating with the atmosphere (hereinafter referred to as “open state”) and a state blocking communication with the atmosphere (hereinafter referred to as “closed state”). ) Can be switched. The pressure increasing / decreasing valve 213b is connected to each of the cases 222a to 222d via the pressure adjustment unit 214, and the state of supplying air discharged from the discharge port 211b to the cases 222a to 222d by the opening and closing thereof (hereinafter, referred to as “the case 222a” to “222d”) It is possible to switch between an “open state” and a state where the air supply is shut off (hereinafter referred to as “closed state”). FIG. 8 shows a state where the pressure increasing / decreasing valves 213a and 213b are open.

  The pressure increasing / decreasing valves 213 c and 213 d are both connected to the suction port 211 b of the air pump 211. The pressure increasing / decreasing valves 213c and 213d are connected in parallel to each other. Further, the pressure increasing / decreasing valve 213c is opened / closed so as to communicate with the atmosphere (hereinafter referred to as “open state”) and to block the communication with the atmosphere (hereinafter referred to as “closed state”). ) Can be switched. The pressure increasing / decreasing valve 213d is connected to each of the cases 222a to 222d via the pressure adjusting unit 214. By opening / closing the pressure increasing / decreasing valve 213d, air in the cases 222a to 222d is sucked from the suction port 211a (hereinafter referred to as "open"). And a state where the inhalation of air is blocked (hereinafter referred to as a “closed state”). FIG. 8 shows a state where the pressure increasing / decreasing valves 213c and 213d are open.

  Therefore, in the present embodiment, the pressurized state is a state where the pressure increasing / decreasing valves 213a and 213d are closed and the pressure increasing / decreasing valves 213b and 213c are opened. That is, in such a state, the air sucked from the suction port 211a through the pressure increasing / decreasing valve 213c is discharged from the discharge port 211b, and the cases 222a to 222 through the pressure increasing / decreasing valve 213b and the pressure adjusting unit 214. 222d is supplied. The reduced pressure state is a state in which the pressure increasing / decreasing valves 213a and 213d are open and the pressure increasing / decreasing valves 213b and 213c are closed. That is, in such a state, the air sucked from the cases 222a to 222d is sucked from the suction port 211a via the pressure adjusting unit 214 and the pressure increasing / decreasing valve 213d. The air discharged from the discharge port 211b is discharged from the pressure increasing / decreasing valve 213a.

  Next, the operation of the ink supply device 200 when supplying ink from the ink pack 221a to the relay tank 230a will be described with reference to FIGS. FIG. 9 is a diagram illustrating a state of the ink supply device 200 when ink is supplied from the ink pack 221a to the relay tank 230a. FIG. 10 is a flowchart illustrating an example of a procedure for supplying ink from the ink pack 221a to the relay tank 230a.

  First, it is determined whether or not the ink inlet / outlet valve 240a is in an ink distribution state (step 301). If it is determined that the ink inlet / outlet valve 240a is closed and the ink circulation state is interrupted (step 301: NO), the ink inlet / outlet valve 240a is opened to enter the ink circulation state (step 302). On the other hand, if it is determined that the ink inlet / outlet valve 240a is open and the ink is in a circulation state (step 301: YES), the following processing is performed.

  Next, it is determined whether the pressure increasing / decreasing valves 213a to 213d are in a pressurized state (step 303). When it is determined that the pressure increasing / decreasing valves 213a to 213d are not in the pressurized state (step 303: NO), the pressure increasing / decreasing valves 213a to 213d are set to the pressurized state (step 304). On the other hand, when it is determined that the pressure increasing / decreasing valves 213a to 213d are in a pressurized state (step 303: YES), the process proceeds to the following process. The states of the pressure increasing / decreasing valves 213a to 213d and the ink inlet / outlet valves 140a to 140d included in the ink supply apparatus 200 at this time are as shown in FIG.

  Next, the air pump 211 is driven (step 305). Then, the air sucked into the suction port 211a of the air pump 211 through the pressure increasing / decreasing valve 213c is discharged from the discharge port 211b of the air pump 211 and supplied to the case 222a through the pressure increasing / decreasing valve 213b and the pressure adjusting unit 214. The At this time, the inside of the case 222a is pressurized (step 306). By pressurizing the inside of the case 222a, the volume of the ink pack 221a is reduced, and the ink sealed in the ink pack 221a is discharged out of the ink pack 221a. Then, the ink discharged from the ink pack 221a is supplied to the relay tank 230a through the ink inlet / outlet valve 240a (step 307).

  Next, the operation of the ink supply device 200 when collecting ink from the relay tank 230a into the ink pack 221a will be described with reference to FIGS. FIG. 11 is a diagram illustrating a state of the ink supply device 200 when ink is collected from the relay tank 230a to the ink pack 221a. FIG. 12 is a flowchart illustrating an example of a procedure for collecting ink from the relay tank 230a into the ink pack 221a.

  First, it is determined whether or not the ink inlet / outlet valve 240a is in an ink circulation state (step 401). If it is determined that the ink inlet / outlet valve 240a is closed and the ink circulation state is interrupted (step 401: NO), the ink inlet / outlet valve 240a is opened to enter the ink circulation state (step 402). On the other hand, if the ink inlet / outlet valve 240a is open and it is determined that the ink is in a circulation state (step 401: YES), the following processing is performed.

  Next, it is determined whether the pressure increasing / decreasing valves 213a to 213d are in a reduced pressure state (step 403). When it is determined that the pressure increasing / decreasing valves 213a to 213d are not in a reduced pressure state (step 403: NO), the pressure increasing / decreasing valves 213a to 213d are set to a reduced pressure state (step 404). On the other hand, when it is determined that the pressure increasing / decreasing valves 213a to 213d are in a reduced pressure state (step 403: YES), the process proceeds to the following process. The states of the pressure increasing / decreasing valves 213a to 213d and the ink inlet / outlet valves 240a to 240d included in the ink supply apparatus 200 at this time are as shown in FIG.

  Next, the air pump 211 is driven (step 405). The air in the case 222a is sucked into the suction port 211a of the air pump 211 through the pressure adjusting unit 214 and the pressure increasing / decreasing valve 213d. Further, the air discharged from the discharge port 211b of the air pump 211 is discharged to the outside through the pressure increasing / decreasing valve 213a. At this time, the pressure in the case 222a is reduced (step 406). By reducing the pressure in the case 222a, the volume of the ink pack 221a increases, and the ink in the relay tank 230a passes through the ink inlet / outlet valve 240a and is collected in the ink pack 221a (step 407).

  At this time, since the check valve 250a is arranged between the relay tank 230a and the print head 41a, the ink in the ink flow path 260 between the check valve 250a and the head 41a flows back into the relay tank 230a. Never do. Therefore, the ink and foreign matters mixed with the air in the vicinity of the print head 41a are not collected in the ink pack 221a.

  The operation of the ink supply device 200 when supplying ink from the ink packs 221b to 221d to the relay tanks 230b to 230d or when collecting ink from the relay tanks 230b to 230d to the ink packs 221b to 221d is also described. As described above, this is the same as the case where ink is supplied from the ink pack 221a to the relay tank 230a or the case where ink is collected from the relay tank 230a to the ink pack 221a.

  As described above, in the ink jet printer provided with the ink supply device 200 of the present embodiment, the ink in the relay tanks 230a to 230d is transferred to the ink packs 221a to 221d as in the ink jet printer 1 of the first embodiment. Can be recovered. Further, the state in which the ink in the ink packs 221a to 221d is supplied to the relay tanks 230a to 230d by the pressure increasing / decreasing valves 213a to 213d having a relatively simple mechanism, and the ink in the relay tanks 230a to 230d are supplied to the ink packs 221a to 221d. It is possible to switch between the state of reverse flow. Therefore, the manufacturing cost of the ink jet printer 1 can be reduced.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various design changes can be made as long as they are described in the claims. Is. For example, in the first and second embodiments described above, an inkjet printer including four removable ink cartridges has been described, but the number of ink cartridges can be arbitrarily changed. Therefore, it is provided with four ink packs each enclosing yellow (yellow), magenta (red purple), cyan (blue green), and black ink, and is limited to an ink jet printer capable of printing a color image. Alternatively, an ink jet printer that includes only one ink pack in which black ink is sealed and can print a monochrome image may be used.

  In the first and second embodiments described above, the case where the volume of the ink pack is increased by reducing the air pressure in the airtight case and the ink in the relay tank is caused to flow back to the ink pack is described. However, the means for causing the ink in the relay tank to flow back to the ink pack is not limited to this. For example, the ink in the relay tank may be caused to flow back to the ink pack by a pump interposed in the ink flow path between the ink pack and the relay tank.

  In the first and second embodiments described above, the air pump is common to the four cases, and the case where the air pressure in the four cases is increased or decreased by one air pump has been described. The air pressure in each case may be increased or decreased by four air pumps.

  In the first and second embodiments described above, a check valve for preventing the flow from the print head side to the relay tank is interposed in the ink flow path between the relay tank and the print head. However, there is no need for a check valve.

  Further, in the first and second embodiments described above, the ink flow path between the ink pack and the relay tank is in a state enabling ink flow between the ink pack and the relay tank and the ink flow. Although an ink inlet / outlet valve that can switch between the state of shutting off the ink is interposed, the ink inlet / outlet valve may not be provided.

1 is a diagram illustrating a schematic configuration of an ink jet printer according to a first embodiment of the present invention. It is a figure which shows schematic structure of the ink supply apparatus of the ink jet type printer of FIG. FIG. 2 is a block diagram illustrating a control system of the ink jet printer of FIG. 1. FIG. 3 is a diagram illustrating a state of the ink supply device in FIG. 2 when supplying ink from the ink pack to the relay tank. 3 is a flowchart illustrating an example of a procedure for supplying ink from an ink pack to a relay tank in the ink supply apparatus of FIG. 2. It is a figure which shows the state of the ink supply apparatus of FIG. 2 at the time of collect | recovering ink to the ink pack from the relay tank. 3 is a flowchart illustrating an example of a procedure for collecting ink from the relay tank into an ink pack in the ink supply apparatus of FIG. 2. It is a figure which shows schematic structure of the ink supply apparatus of the ink jet type printer of 2nd Embodiment. It is a figure which shows the state of the ink supply apparatus of FIG. 8 when supplying ink to the relay tank from the inside of an ink pack. 9 is a flowchart illustrating an example of a procedure for supplying ink from an ink pack to a relay tank in the ink supply apparatus of FIG. 8. It is a figure which shows the state of the ink supply apparatus of FIG. 8 when collect | recovering ink to the ink pack from the relay tank. FIG. 9 is a flowchart illustrating an example of a procedure for collecting ink from the relay tank into an ink pack in the ink supply apparatus of FIG. 8. It is a figure which shows schematic structure of the conventional ink supply apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer 41a-41d Print head 100, 200 Ink supply apparatus 110, 210 Pressure-reduction part (ink collection mechanism)
111, 211 Air pump 112, 212 Air flow path 113 Pressure-reducing valve (Direction switching valve)
213a to 213d Pressure increasing / decreasing valves (first to fourth direction switching valves)
114, 214 Pressure adjusting unit 120a-120d, 220a-220d Ink cartridge 121a-121d, 221a-221d Ink pack 122a-122d, 222a-222d Case (airtight case)
130a to 130d, 230a to 230d Relay tank 140a to 140d, 240a to 240d Ink inlet / outlet valve (ink supply valve)
150a to 150d, 250a to 250d Check valve 160, 260 Ink flow path

Claims (9)

An ink pack placement section in which an ink pack filled with ink is placed;
A relay tank for storing ink supplied from the ink pack;
A print head for ejecting ink supplied from the relay tank to a print medium;
An ink jet printer, comprising: an ink recovery mechanism capable of causing the ink in the relay tank to flow backward to the ink pack. The ink pack disposition portion includes an airtight case that can store the ink pack, and the volume of the ink pack is variable according to the atmospheric pressure in the airtight case,
The ink recovery mechanism is
An air pump,
2. The ink jet printer according to claim 1, further comprising an air flow path for connecting the air pump and the airtight case so that air is discharged from the airtight case.   A state of being interposed in the air flow path, wherein air is discharged from the airtight case through the air flow path, a state of supplying air via the air flow path into the airtight case, and the airtightness 3. The ink jet printer according to claim 2, further comprising a direction switching valve that can be selectively switched to any one of states in which the case is opened to the atmosphere. When supplying ink in the ink pack to the relay tank, the direction switching valve is switched to a state where air is supplied to the airtight case via the air flow path,
When the ink in the relay tank is caused to flow back to the ink pack, it further includes a switching control means for switching the direction switching valve to a state where air is discharged from the airtight case through the air flow path. The ink jet printer according to claim 3. The air flow path is
A first air flow path having one end connected to the airtight case and the other end connected to an air discharge port of the air pump;
A second air flow path having one end connected to the airtight case and the other end connected to an air suction port of the air pump;
A third air flow path connected to the first air flow path at a first branch point and connecting the first air flow path and the outside;
Connected to the second air flow path at a second branch point, and includes a fourth air flow path connecting the second air flow path and the outside,
A state in which the first air flow path is interposed between the first branch point and the airtight case, and air is supplied from the air pump through the first air flow path into the airtight case. And a first directional control valve that is selectively switched to any state of closing the first air flow path;
A state in which the second air flow path is interposed between the second branch point and the airtight case, and air is discharged from the airtight case through the second air flow path; and A second directional control valve that is selectively switched to any state of closing the second air flow path;
It is interposed in the third air flow path, and is selected from the state in which the air in the first air flow path is released to the outside and the state in which the third air flow path is closed A third directional control valve that is switched automatically,
The state is interposed between the fourth air flow path and selected from the state in which the air in the second air flow path is released to the outside and the state in which the fourth air flow path is closed The inkjet printer according to claim 2, further comprising a fourth direction switching valve that can be switched automatically. When supplying ink in the ink pack to the relay tank,
In a state in which air is supplied into the airtight case from the air pump via the first air flow path, the first direction switching valve.
In the state where the second air flow path is closed, the second direction switching valve is closed.
In a state where the third direction switching valve is closed with the third air flow path,
Switching each of the fourth direction switching valves to a state in which the air in the second air flow path is released to the outside;
When the ink in the relay tank flows back to the ink pack,
The first direction switching valve is closed to the first air flow path,
The second direction switching valve is in a state where air is discharged from the airtight case via the second air flow path.
In the state where the air in the first air flow path is released to the outside, the third direction switching valve.
6. The ink jet printer according to claim 5, further comprising switching control means for switching the fourth direction switching valve to a state in which the fourth air flow path is closed. A plurality of the print head, the relay tank and the airtight case, respectively;
The ink jet printer according to claim 2, wherein the air pump is common to the plurality of airtight cases.   A first ink flow path connecting the print head and the relay tank, and preventing the ink from flowing back from the print head to the relay tank via the first ink flow path; The inkjet printer according to claim 1, further comprising a check valve. A sensor for detecting the amount of ink stored in the relay tank;
An ink supply valve that is interposed in a second ink flow path that connects the relay tank and the ink pack and that can open and close the second ink flow path according to the detection result of the sensor is further provided. The ink jet printer according to claim 1, wherein the ink jet printer is provided.

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