JP2007203523A - Deaerator, liquid discharge head, liquid discharge device and dissolved gas removal method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deaerator which can efficiently remove a dissolved gas of a liquid and can restrain a change in the physical property of the liquid, a liquid discharge head and a liquid discharge device and a dissolved gas removal method. <P>SOLUTION: A gas exchange section 17 which communicates with an ink channel 15 and a gas transport liquid channel 100 has a gas permeable membrane 102 which contacts an ink 120 and the gas transport liquid 122 and separates the ink 120 from the gas transport liquid 122. A dissolved gas of the ink 120 melts into the gas permeable membrane 102 and dispersed and pass and melts into the gas transport liquid 122. In the gas exchange section 17, since a preferable ink from which the dissolved gas of the ink 120 is removed is supplied to the head 50, bubble occurrence in the head 50 can be restrained and a discharge abnormality due to the bubble occurrence in the ink is prevented. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a deaeration device, a liquid ejection head, a liquid ejection device, and a dissolved gas removal method, and more particularly, to a deaeration technique for removing gas dissolved in a liquid.

  In an inkjet recording device that forms a desired image by ejecting ink onto the media, when performing image formation using ink with a high dissolved gas concentration, bubbles are generated by cavitation near the nozzle when ink droplets are ejected. However, it may cause ejection abnormalities such as non-ejection and flying bends of ink droplets. In order to avoid such abnormal discharge due to the generation of bubbles, deaerated ink having a low dissolved gas concentration is used. The dissolved gas concentration represents the amount of gas (unit: mg / l) dissolved in a unit volume of liquid (for example, water).

  However, even when deaerated ink is used, the concentration of dissolved gas in the ink in a short period of time will come into contact with the atmosphere at locations such as an ink tank or nozzle that is open to the atmosphere, or where air bubbles enter the ink path. When the state of contact with the atmosphere continues to increase, the dissolved gas concentration of the ink reaches the saturation concentration. In the ink supply path, the dissolved gas concentration increases in proportion to the degree of gas barrier properties. As described above, such an increase in the dissolved gas concentration causes bubbles in the ink, and various measures have been taken to suppress the increase in the dissolved gas concentration in the ink.

In the invention described in Patent Document 1, in an ink degassing method for ink jet recording in which ink for ink jet recording is passed through a gas permeable film, the ink for ink jet recording is heated. To pass through the membrane.
JP 2003-253169 A

  However, in the invention described in Patent Document 1, since the area separated from the ink by the gas permeable film is depressurized, the solvent such as water is vaporized together with the dissolved gas of the ink and passes through the film. As a result, the physical properties of the ink such as viscosity change. If the viscosity of the ink is increased by degassing the ink, there is a risk of causing an ejection abnormality due to the increased viscosity of the ink.

  The present invention has been made in view of such circumstances, and provides a degassing device, a liquid discharge head, a liquid discharge device, and a dissolved gas removal method capable of efficiently removing dissolved dissolved gas and suppressing changes in physical properties of the liquid. The purpose is to provide.

  In order to achieve the object, the deaeration device according to the invention described in claim 1 includes a first flow path serving as a first liquid flow path and a dissolved gas amount per unit volume. A second flow path serving as a flow path for a second liquid having a gas concentration equal to or lower than that of the first liquid; the first flow path; and the second flow path; Gas exchange means having a gas permeable membrane that contacts the second liquid and separates the first liquid and the second liquid.

  According to the present invention, in the gas exchange means, the gas dissolved in the first liquid is moved to the second liquid via the gas permeable membrane to remove the dissolved gas of the first liquid, so that the first liquid The dissolved gas of the first liquid can be efficiently removed without changing the physical properties of the first liquid.

  The 2nd liquid which functions as a gas carrying liquid is a state which can melt | dissolve the gas which moved from the 1st liquid. That is, the second liquid is in a non-saturated state where the dissolved gas concentration does not reach the saturation concentration. The second liquid preferably has physical properties similar to those of the first liquid.

  The invention described in claim 2 relates to an embodiment of the deaeration device according to claim 1, wherein dissolved gas is removed by the dissolved gas removing means for removing the dissolved gas in the second liquid, and the dissolved gas removing means. And circulating means for circulating the second liquid to the gas exchange part.

  According to the second aspect of the present invention, the dissolved gas concentration of the second liquid can be kept below a predetermined value by providing the second channel with the dissolved gas removing means. Further, by circulating the second liquid from which the dissolved gas is removed by the circulation means, the second liquid in a preferable state (the dissolved gas concentration is controlled) is always supplied to the gas exchange means.

  The dissolved gas concentration detecting means for detecting the dissolved gas concentration (dissolved oxygen concentration) of the second liquid, and the dissolved gas removing means are controlled based on the detection result of the dissolved gas concentration detecting means (dissolved gas of the second liquid) There is an aspect including a dissolved gas removal control means for controlling the dissolved gas removal means so that the concentration becomes a predetermined value.

  The circulation means includes a circulation flow path connecting the dissolved gas removal means and the gas exchange means, a pressure variable means for varying the pressure (flow velocity) of the second liquid in the circulation flow path, and the pressure variable means. And a pressure control means for controlling.

  A third aspect of the present invention relates to the one aspect of the deaeration device according to the first or second aspect, and further includes a temperature adjusting means for adjusting a temperature of the second liquid.

  According to the invention described in claim 3, by adjusting the temperature of the second liquid, the temperature of the first liquid can be adjusted by heat exchange through the gas permeable membrane. Moreover, the improvement of the dissolved gas removal efficiency of a 1st liquid is anticipated by raising the temperature of the 1st liquid near a gas permeable film.

  The temperature adjusting means includes a temperature detecting means for detecting the temperature of the second liquid (or the first liquid), a temperature variable means for changing the temperature of the second liquid (or the first liquid), and the temperature. There exists an aspect provided with the temperature control means which controls a temperature variable means based on the detection result of a detection means.

  A fourth aspect of the present invention relates to an embodiment of the deaeration device according to the first, second, or third aspect, wherein the second liquid includes a liquid containing a molybdenum complex and is in contact with at least the gas permeable membrane. A light irradiation means for irradiating light to the second liquid in the region is provided.

  According to the fourth aspect of the present invention, a liquid containing a molybdenum complex having a property that oxygen is easily attached when light is applied and oxygen is easily released when light is blocked is applied to the second liquid. According to the configuration provided with the light irradiation means for irradiating the second liquid in the region in contact with the film, the oxygen dissolved in the first liquid is easily attached to the second liquid, so that the first liquid is dissolved. Improvement of gas (dissolved oxygen) removal efficiency is expected.

  A fifth aspect of the present invention relates to one aspect of the deaeration device according to any one of the first to fourth aspects, wherein the gas exchange section includes a first branch flow through which the first liquid flows. A plurality of paths are provided, and the gas permeable membrane is provided in a portion of the first branch flow path that contacts the second liquid.

  According to the fifth aspect of the present invention, in the gas exchange section, the area of the portion of the gas permeable membrane that contacts the first liquid and the second liquid can be increased, and the dissolved gas removal of the first liquid can be achieved. Contributes to improved efficiency.

  A sixth aspect of the present invention relates to one aspect of the deaeration device according to any one of the first to fourth aspects, wherein the gas exchange section is a second branch flow through which the second liquid flows. A plurality of paths are provided, and the gas permeable membrane is provided in a portion of the second branch channel that contacts the first liquid.

  According to the sixth aspect of the present invention, in the gas exchange section, the area of the portion of the gas permeable membrane that contacts the first liquid and the second liquid can be increased, and the dissolved gas removal of the first liquid can be achieved. Contributes to improved efficiency.

  A seventh aspect of the invention relates to an aspect of the deaeration device according to any one of the first to sixth aspects, wherein the relative flow rates of the first liquid and the second liquid are determined. It is characterized by comprising a flow rate varying means for varying.

  According to the invention described in claim 7, by making the flow rate of the second liquid larger than the flow rate of the first liquid, a differential pressure is generated between the first liquid and the second liquid, The dissolved gas removal efficiency of 1 liquid can be improved.

  The invention according to an eighth aspect relates to one aspect of the deaeration device according to any one of the first to seventh aspects, wherein the concentration of dissolved gas in the saturated state of the second liquid is the first concentration. It is more than the dissolved gas concentration of the saturated state of the liquid.

  According to the invention described in claim 8, by setting the concentration of the dissolved gas in the saturated state of the second liquid to be equal to or higher than the first liquid, the amount of gas that can be dissolved in the second liquid is increased, The gas removal efficiency of the liquid can be improved.

  In order to achieve the above object, a liquid discharge head according to a ninth aspect of the present invention is a liquid discharge head that discharges a first liquid onto a medium. The deaeration device according to claim 1 is provided.

  According to the ninth aspect of the present invention, by providing a degassing device including a gas permeable membrane inside the liquid discharge head, the configuration of the device on which the liquid discharge head is mounted can be simplified. And contributes to the miniaturization of the device.

  There is a mode in which the liquid discharge head includes a nozzle that discharges the liquid, a liquid chamber that stores the liquid discharged from the nozzle, and a pressurizing unit that pressurizes the liquid in the liquid chamber. In addition, the liquid ejection head includes a line-type head having ejection hole arrays having a length corresponding to the entire width of the recording medium (image forming width of the recording medium), and ejection hole arrays having a length less than the entire width of the recording medium. There is a serial type head that scans a short head having a width of the recording medium.

  The line type liquid discharge head has a length corresponding to the full width of the recording medium by arranging short heads having short discharge hole arrays that are less than the length corresponding to the full width of the recording medium in a staggered arrangement. It is good.

  In order to achieve the above object, a liquid discharge apparatus according to a tenth aspect of the present invention includes a liquid discharge head that discharges a first liquid onto a medium, and any one of the first to eighth aspects. The deaeration device described in 1 is provided.

  The liquid ejecting apparatus includes an image forming apparatus that ejects a liquid onto a medium and forms a desired image by combining dots formed by the liquid. Note that the “image” here includes text such as characters and symbols, and patterns having a predetermined shape (for example, a wiring pattern on a printed circuit board) in addition to so-called images such as photographs and line drawings.

  The medium includes various media that receive the first liquid ejected from the liquid ejection head. For example, there are papers such as continuous paper and cut paper, resin sheets, metal sheets, fibers (cloth), and the like.

  A method invention is provided to achieve the above object. That is, the dissolved gas removal method according to claim 11 includes: a first liquid; and a second liquid having a dissolved gas concentration represented by a dissolved gas amount per unit volume equal to or lower than the first liquid. The dissolved gas of the first liquid is removed by contacting through a gas permeable membrane.

  The invention according to claim 12 relates to an aspect of the gas removal method according to claim 11, wherein the dissolved gas concentration in the saturated state of the second liquid is equal to or higher than the dissolved gas concentration in the saturated state of the first liquid. It is characterized by being.

  According to the present invention, in the gas exchange means, the gas dissolved in the first liquid is moved to the second liquid via the gas permeable membrane to remove the dissolved gas of the first liquid, so that the first liquid The dissolved gas of the first liquid can be efficiently removed without changing the physical properties of the first liquid.

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

[Overall configuration of inkjet recording apparatus]
FIG. 1 is an overall configuration diagram of an ink jet recording apparatus according to an embodiment of the present invention. As shown in the figure, the ink jet recording apparatus 10 includes a plurality of ink jet heads (hereinafter referred to as “ink jet heads”) corresponding to black (K), cyan (C), magenta (M), and yellow (Y) inks. A printing unit 12 having 12K, 12C, 12M, and 12Y, an ink storage / loading unit 14 that stores ink to be supplied to each of the heads 12K, 12C, 12M, and 12Y, and a recording sheet as a recording medium 16 is disposed opposite to the decurling unit 20 for removing the curl of the recording paper 16 and the nozzle surface (ink ejection surface) of the printing unit 12 to improve the flatness of the recording paper 16. An adsorption belt conveyance unit 22 that conveys the recording paper 16 while holding it, and a paper discharge unit 26 that discharges the recorded recording paper (printed material) to the outside.

  The ink storage / loading unit 14 has an ink supply tank that stores ink of a color corresponding to each of the heads 12K, 12C, 12M, and 12Y. Each tank has a required ink flow path 15 (first flow path). Via the heads 12K, 12C, 12M, and 12Y. As will be described in detail later, between the ink storage / loading unit 14 and the heads 12K, 12C, 12M, and 12Y (in the vicinity of the heads 12K, 12C, 12M, and 12Y), the ink is supplied to the heads 12K, 12C, 12M, and 12Y. A gas exchange unit 17 that removes (degass) the dissolved gas of each color ink is provided.

  Further, the ink storage / loading unit 14 includes notifying means (display means, warning sound generating means) for notifying when the ink remaining amount is low, and has a mechanism for preventing erroneous loading between colors. ing.

  In FIG. 1, a magazine for rolled paper (continuous paper) is shown as an example of the paper supply unit 18, but a plurality of magazines having different paper widths, paper quality, and the like may be provided side by side. Further, instead of the roll paper magazine or in combination therewith, the paper may be supplied by a cassette in which cut papers are stacked and loaded.

  When multiple types of recording paper are used, an information recording body such as a barcode or wireless tag that records paper type information is attached to the magazine, and the information on the information recording body is read by a predetermined reader. Thus, it is preferable to automatically determine the type of recording medium (media type) to be used and perform ink ejection control so as to realize appropriate ink ejection according to the media type.

  The recording paper 16 delivered from the paper supply unit 18 retains curl due to having been loaded in the magazine. In order to remove this curl, heat is applied to the recording paper 16 by the heating drum 30 in the direction opposite to the curl direction of the magazine in the decurling unit 20. At this time, it is more preferable to control the heating temperature so that the printed surface is slightly curled outward.

  In the case of an apparatus configuration that uses roll paper, a cutter (first cutter) 28 is provided as shown in FIG. 1, and the roll paper is cut into a desired size by the cutter 28. The cutter 28 includes a fixed blade 28A having a length equal to or greater than the conveyance path width of the recording paper 16, and a round blade 28B that moves along the fixed blade 28A. The fixed blade 28A is provided on the back side of the print. The round blade 28B is disposed on the printing surface side with the conveyance path interposed therebetween. Note that the cutter 28 is not necessary when cut paper is used.

  After the decurling process, the cut recording paper 16 is sent to the suction belt conveyance unit 22. The suction belt conveyance unit 22 has a structure in which an endless belt 33 is wound between rollers 31 and 32, and at least a portion facing the nozzle surface of the printing unit 12 forms a horizontal surface (flat surface). Has been.

  The belt 33 has a width that is wider than the width of the recording paper 16, and a plurality of suction holes (not shown) are formed on the belt surface. As shown in FIG. 1, a suction chamber 34 is provided at a position facing the nozzle surface of the printing unit 12 inside the belt 33 spanned between the rollers 31 and 32, and the suction chamber 34 is connected to the fan 35. The recording paper 16 is sucked and held on the belt 33 by suctioning to negative pressure.

  When the power of the motor (reference numeral 88 in FIG. 7) is transmitted to at least one of the rollers 31 and 32 around which the belt 33 is wound, the belt 33 is driven in the clockwise direction in FIG. The held recording paper 16 is conveyed from left to right in FIG.

  Since ink adheres to the belt 33 when a borderless print or the like is printed, the belt cleaning unit 36 is provided at a predetermined position outside the belt 33 (an appropriate position other than the print area). Although details of the configuration of the belt cleaning unit 36 are not shown, for example, there are a method of niping a brush roll, a water absorbing roll, etc., an air blow method of blowing clean air, or a combination thereof. In the case where the cleaning roll is nipped, the cleaning effect is great if the belt linear velocity and the roller linear velocity are changed.

  Although a mode using a roller / nip conveyance mechanism instead of the suction belt conveyance unit 22 is also conceivable, if the roller / nip conveyance is performed in the print area, the image easily spreads because the roller contacts the printing surface of the sheet immediately after printing. There is a problem. Therefore, as in this example, suction belt conveyance that does not bring the image surface into contact with each other in the print region is preferable.

  A heating fan 40 is provided on the upstream side of the printing unit 12 on the paper conveyance path formed by the suction belt conveyance unit 22. The heating fan 40 blows heated air on the recording paper 16 before printing to heat the recording paper 16. Heating the recording paper 16 immediately before printing makes it easier for the ink to dry after landing.

  Each of the heads 12K, 12C, 12M, and 12Y of the printing unit 12 has a length corresponding to the maximum paper width of the recording paper 16 targeted by the inkjet recording apparatus 10, and the nozzle surface has a recording medium of the maximum size. This is a full-line type head in which a plurality of nozzles for ink discharge are arranged over a length exceeding at least one side (full width of the drawable range) (see FIG. 2).

  The heads 12K, 12C, 12M, and 12Y are arranged in the order of black (K), cyan (C), magenta (M), and yellow (Y) from the upstream side in the recording paper 16 feed direction. 12K, 12C, 12M, and 12Y are fixedly installed so as to extend in the conveyance direction of the recording paper 16 (hereinafter referred to as the paper feeding direction).

  A color image can be formed on the recording paper 16 by discharging different color inks from the heads 12K, 12C, 12M, and 12Y while transporting the recording paper 16 by the suction belt transporting section 22.

  As described above, according to the configuration in which the full-line heads 12K, 12C, 12M, and 12Y having nozzle rows that cover the entire width of the paper are provided for each color, the recording paper 16 and the printing unit in the paper feeding direction (sub-scanning direction). The image can be recorded on the entire surface of the recording paper 16 by performing the operation of relatively moving the 12 only once (that is, by one sub-scanning). Thereby, it is possible to perform high-speed printing as compared with a shuttle type head in which the recording head reciprocates in a direction orthogonal to the paper transport direction, and productivity can be improved.

  In this example, the configuration of KCMY standard colors (four colors) is illustrated, but the combination of ink color and number of colors is not limited to this embodiment, and light ink, dark ink, and special color ink are used as necessary. May be added. For example, it is possible to add an ink jet head that discharges light ink such as light cyan and light magenta. Also, the arrangement order of the color heads is not particularly limited. Further, after the treatment liquid and the ink are attached to the recording paper 16, the ink color material is aggregated or insolubilized on the recording paper 16 to separate the ink solvent and the ink color material on the recording paper 16. In this ink jet recording apparatus, an ink jet head may be provided as means for attaching the treatment liquid to the recording paper 16.

  A post-drying unit 42 is provided following the printing unit 12. The post-drying unit 42 is means for drying the printed image surface, and for example, a heating fan is used. Since it is preferable to avoid contact with the printing surface until the ink after printing is dried, a method of blowing hot air is preferred.

  A heating / pressurizing unit 44 is provided following the post-drying unit 42. The heating / pressurizing unit 44 is a means for controlling the glossiness of the image surface, and pressurizes with a pressure roller 45 having a predetermined surface uneven shape while heating the image surface to transfer the uneven shape to the image surface. To do.

  When the recording paper 16 is pressed by the heating / pressurizing unit 44, when printing is performed on the porous paper with dye-based ink, the pores of the paper are blocked by pressurization, which causes damage to the dye molecules such as ozone. By preventing the contact with the image, the weather resistance of the image is improved.

  The printed matter generated in this manner is outputted from the paper output unit 26. It is preferable that the original image to be printed (printed target image) and the test print are discharged separately. The ink jet recording apparatus 10 is provided with a sorting means (not shown) for switching the paper discharge path in order to select the print product of the main image and the print product of the test print and send them to the discharge units 26A and 26B. Yes. Note that when the main image and the test print are simultaneously formed in parallel on a large sheet, the test print portion is separated by a cutter (second cutter) 48. The cutter 48 is provided immediately before the paper discharge unit 26, and cuts the main image and the test print unit when the test print is performed on the image margin. The structure of the cutter 48 is the same as that of the first cutter 28 described above, and includes a fixed blade 48A and a round blade 48B.

  Although not shown in FIG. 1, the paper output unit 26A for the target prints is provided with a sorter for collecting prints according to print orders.

[Head structure]
Next, the structure of the head will be described. Since the structures of the respective heads 12K, 12C, 12M, and 12Y for each color are common, the heads are represented by the reference numeral 50 in the following.

  FIG. 3A is a plan perspective view showing an example of the structure of the head 50, and FIG. 3B is an enlarged view of a part thereof. 3C is a perspective plan view showing another example of the structure of the head 50, and FIG. 4 is a sectional view showing a three-dimensional configuration of the ink chamber unit (4-4 in FIGS. 3A and 3B). It is a cross-sectional view taken along a line, and in order to increase the dot pitch printed on the recording paper 16, it is necessary to increase the nozzle pitch in the head 50. The head 50 of this example is shown in FIG. As shown in (a) and (b), a plurality of ink chamber units 53 including nozzles 51 serving as ink droplet ejection holes and pressure chambers 52 corresponding to the nozzles 51 are arranged in a staggered matrix (2 It has a structure that is arranged in a dimensional manner, thereby increasing the density of the substantial nozzle interval (projection nozzle pitch) projected so as to be aligned along the longitudinal direction of the head (direction perpendicular to the paper feed direction). Has achieved.

  The configuration in which one or more nozzle rows are configured over a length corresponding to the entire width of the recording paper 16 in a direction substantially orthogonal to the feeding direction of the recording paper 16 is not limited to this example. For example, instead of the configuration of FIG. 3 (a), short head blocks 50 ′ in which a plurality of nozzles 51 are two-dimensionally arranged are arranged in a staggered manner and connected as shown in FIG. 3 (c). A line head having a nozzle row having a length corresponding to the entire width of the recording paper 16 may be configured.

  The pressure chamber 52 provided corresponding to each nozzle 51 has a substantially square planar shape, and the nozzle 51 and the supply port 54 are provided at both corners on the diagonal line. Each pressure chamber 52 communicates with a common flow channel 55 through a supply port 54. The common flow channel 55 communicates with an ink supply tank (not shown in FIG. 4, described as reference numeral 60 in FIG. 5) as an ink supply source, and the ink supplied from the ink supply tank is the common flow channel 55 of FIG. Is distributed and supplied to each pressure chamber 52.

  An actuator 58 having an individual electrode 57 is joined to a diaphragm 56 that constitutes the top surface of the pressure chamber 52 and also serves as a common electrode, and the actuator 58 is deformed by applying a drive voltage to the individual electrode 57. Thus, ink is ejected from the nozzle 51. When ink is ejected, new ink is supplied from the common channel 55 to the pressure chamber 52 through the supply port 54.

  As shown in FIG. 3B, the ink chamber units 53 having such a structure are arranged in a fixed manner along a row direction along the main scanning direction and an oblique column direction having a constant angle θ that is not orthogonal to the main scanning direction. By arranging a large number of patterns in a lattice pattern, the high-density nozzle head of this example is realized.

  That is, with a structure in which a plurality of ink chamber units 53 are arranged at a constant pitch d along the direction of an angle θ with respect to the main scanning direction, the pitch P of the nozzles projected so as to be aligned in the main scanning direction is d × cos θ. Thus, in the main scanning direction, each nozzle 51 can be handled equivalently as a linear arrangement with a constant pitch P. With such a configuration, it is possible to realize a high-density nozzle configuration in which 2400 nozzle rows are projected per inch (2400 nozzles / inch) so as to be aligned in the main scanning direction.

  In implementing the present invention, the nozzle arrangement structure is not limited to the illustrated example, and various nozzle arrangement structures such as an arrangement structure having one nozzle row in the sub-scanning direction can be applied.

[Configuration of ink supply system]
FIG. 5 is a schematic diagram showing the configuration of the ink supply system in the inkjet recording apparatus 10. The ink supply tank 60 is a base tank that supplies ink to the head 50 and is installed in the ink storage / loading unit 14 described with reference to FIG. There are two types of ink supply tank 60: a system that replenishes ink from a replenishment port (not shown) and a cartridge system that replaces the entire tank when the ink remaining amount is low. A cartridge system is suitable for changing the ink type according to the intended use. In this case, it is preferable that the ink type information is identified by a barcode or the like, and ejection control is performed according to the ink type. The ink supply tank 60 of FIG. 5 is equivalent to the ink storage / loading unit 14 of FIG. 1 described above.

  As shown in FIG. 5, a filter 62 is provided in the ink flow path 15 between the ink supply tank 60 and the head 50 in order to remove foreign matters and bubbles. The filter mesh size is preferably equal to or smaller than the nozzle diameter (generally about 20 μm). Although not shown in FIG. 5, a configuration in which a sub tank is provided in the vicinity of the head 50 or integrally with the head 50 is also preferable. The sub-tank has a function of improving a damper effect and refill that prevents fluctuations in the internal pressure of the head.

  Further, the inkjet recording apparatus 10 is provided with a cap 64 as a means for preventing the nozzle 51 from drying or preventing an increase in ink viscosity near the nozzle, and a cleaning blade 66 as a nozzle surface cleaning means. The maintenance unit including the cap 64 and the cleaning blade 66 can be moved relative to the head 50 by a moving mechanism (not shown), and is moved from a predetermined retracted position to a maintenance position below the head 50 as necessary.

  The cap 64 is displaced up and down relatively with respect to the head 50 by an elevator mechanism (not shown). The cap 64 is raised to a predetermined raised position when the power is turned off or during printing standby, and is brought into close contact with the head 50, thereby covering the nozzle surface with the cap 64.

  The cleaning blade 66 is made of an elastic member such as rubber, and can slide on the ink discharge surface (nozzle plate surface) of the head 50 by a blade moving mechanism (not shown). When ink droplets or foreign substances adhere to the nozzle plate, the nozzle plate surface is wiped by sliding the cleaning blade 66 on the nozzle plate to clean the nozzle plate surface.

  During printing or standby, when a specific nozzle is used less frequently and the ink viscosity in the vicinity of the nozzle increases, preliminary discharge is performed toward the cap 64 to discharge the deteriorated ink.

  When air bubbles are mixed in the ink in the head 50 (in the pressure chamber 52), the cap 64 is applied to the head 50, and the ink in the pressure chamber 52 (ink in which the air bubbles are mixed) is removed by suction with the suction pump 67. Then, the sucked and removed ink is sent to the collection tank 68. This suction operation is performed when the initial ink is loaded into the head 50 or when the ink starts to be used after being stopped for a long time, or when the error is extracted due to variations in the capacitance of the actuator 58. The deteriorated ink mixed with is sucked out.

  If the head 50 is not ejected for a certain period of time, the ink solvent near the nozzles evaporates and the viscosity of the ink near the nozzles increases. Will not discharge. Therefore, before this state is reached (within the viscosity range in which ink can be discharged by the operation of the actuator 58), the actuator 58 is operated toward the ink receiver to discharge ink in the vicinity of the nozzle whose viscosity has increased. “Preliminary discharge” is performed. In order to prevent foreign matter from being mixed into the nozzle 51 by the wiper rubbing operation after the dirt on the nozzle plate surface is cleaned by a wiper such as a cleaning blade 66 provided as a nozzle surface cleaning means. Preliminary discharge is performed. Note that the preliminary discharge may be referred to as “empty discharge”, “purge”, “spitting”, or the like.

  In addition, if bubbles are mixed into the nozzle 51 or the pressure chamber 52 or if the viscosity increase of the ink in the nozzle 51 exceeds a certain level, ink cannot be ejected by the preliminary ejection, and the suction operation described below is performed.

  That is, when bubbles are mixed in the ink in the nozzle 51 or the pressure chamber 52, or when the ink viscosity in the nozzle 51 rises to a certain level or more, the ink can be ejected from the nozzle 51 even if the actuator 58 is operated. Disappear. In such a case, a suction means for sucking ink in the pressure chamber 52 with a pump or the like is brought into contact with the nozzle surface of the head 50 to suck ink mixed with bubbles or thickened ink.

  However, since the above suction operation is performed on the entire ink in the pressure chamber 52, the ink consumption is large. Therefore, when the increase in viscosity is small, it is preferable to perform preliminary discharge as much as possible.

  As described with reference to FIG. 1, the ink flow path 15 between the ink supply tank 60 and the head 50 contains ink supplied to the head 50 (not shown in FIG. 5 and indicated by reference numeral 120 in FIG. 6). A gas exchange unit 17 for removing dissolved gas is provided. The gas exchange unit 17 includes an ink channel 15 and a gas transport liquid channel 100 (second channel) that serves as a channel for the gas transport liquid (not shown in FIG. 5 and indicated by reference numeral 122 in FIG. 6). And a gas permeable membrane 102 that separates the ink and the gas carrying liquid inside.

  On the upstream side of the gas exchange unit 17 of the gas carrying liquid channel 100, a deaeration unit 106 that degass the gas carrying liquid, and the gas carrying liquid degassed by the deaeration unit 106 are supplied to the gas exchange unit 17. And a pump 108 that circulates in the air.

  That is, the gas carrying liquid is supplied to the gas exchange unit 17 when the deaeration process is performed in the deaeration unit 106, and when the dissolved gas of the ink is absorbed by the gas exchange unit 17, the deaeration unit 106 is supplied via the pump 108. And degassing treatment is performed again.

  For the gas permeable membrane 102 described above, polyimide, cellulose acetate, polysulfone, polyamide, polyether amide, polyether imide, or the like is applied. In addition, a known technique such as a hollow fiber membrane method can be applied to the deaeration unit 106.

[Description of Gas Exchanger, First Embodiment]
Next, the gas exchange part 17 is explained in full detail using FIG. FIG. 6 is a diagram illustrating a schematic configuration of the gas exchange unit 17. As shown in FIG. 6, in the gas exchange unit 17, the ink 120 (first liquid) supplied from the ink flow path 15 and the gas carrying liquid 122 (second liquid) supplied from the gas carrying liquid flow path 100 are used. Are separated from each other by a gas permeable membrane 102.

  The gas carrying liquid 122 is in a state where the dissolved gas concentration is equal to or lower than the ink 120 and the dissolved gas concentration does not reach the saturation concentration. Note that the gas carrying liquid 122 is more preferably a component (physical properties) close to the ink 120. Specific examples of the gas carrying liquid 122 include water, inks having substantially the same composition as the ink 120, and the like.

  In general, the ink 120 has a tendency that the dissolved gas concentration in the saturated state decreases as the content of additives such as pigments increases. In order to further improve the deaeration effect of the ink 120, it is more preferable that the gas carrying liquid 122 has a saturated dissolved gas concentration of the ink 120 or higher. A specific example of a liquid in which the saturated dissolved gas concentration is equal to or higher than the saturated dissolved gas concentration of the ink 120 is pure water.

  In the gas exchange unit 17 shown in FIG. 6, the dissolved gas (or bubble) 124 of the ink 120 is dissolved and diffused in the gas permeable film 102, passes through the gas permeable film 102, and is dissolved in the gas carrying liquid 122. In other words, the dissolved gas 124 of the ink 120 moves to the gas carrying liquid 122 through the gas permeable membrane 102, and the dissolved gas 124 of the ink 120 is removed.

  Since the ink 120 from which the dissolved gas has been removed (degassed) in this way is supplied to the head 50, the formation of bubbles in the dissolved gas of the ink inside the head 50 (the generation of bubbles inside the head 50) is suppressed. Thus, abnormal discharge due to the bubbles is prevented.

[Explanation of control system]
FIG. 7 is a principal block diagram showing the system configuration of the inkjet recording apparatus 10. The inkjet recording apparatus 10 includes a communication interface 70, a system controller 72, an image memory 74, a motor driver 76, a heater driver 78, a print control unit 80, an image buffer memory 82, a head driver 84, and the like.

  The communication interface 70 is an interface unit that receives image data sent from the host computer 86. As the communication interface 70, a serial interface such as USB (Universal Serial Bus), IEEE 1394, Ethernet (registered trademark), a wireless network, or a parallel interface such as Centronics can be applied. In this part, a buffer memory (not shown) for speeding up communication may be mounted. Image data sent from the host computer 86 is taken into the inkjet recording apparatus 10 via the communication interface 70 and temporarily stored in the image memory 74.

  The image memory 74 is a storage unit that temporarily stores an image input via the communication interface 70, and data is read and written through the system controller 72. The image memory 74 is not limited to a memory made of a semiconductor element, and a magnetic medium such as a hard disk may be used.

  The system controller 72 includes a central processing unit (CPU) and its peripheral circuits, and functions as a control device that controls the entire inkjet recording apparatus 10 according to a predetermined program, and also functions as an arithmetic device that performs various calculations. . That is, the system controller 72 controls each part such as the communication interface 70, the image memory 74, the motor driver 76, the heater driver 78, etc., performs communication control with the host computer 86, read / write control of the image memory 74, etc. A control signal for controlling the motor 88 and the heater 89 of the transport system is generated.

  The image memory 74 stores programs executed by the CPU of the system controller 72 and various data necessary for control. Note that the image memory 74 may be a non-rewritable storage means, or may be a rewritable storage means such as an EEPROM. The image memory 74 is used as a temporary storage area for image data, and is also used as a program development area and a calculation work area for the CPU.

  The motor driver 76 is a driver (drive circuit) that drives the motor 88 in accordance with an instruction from the system controller 72. The heater driver 78 is a driver that drives the heater 89 such as the post-drying unit 42 in accordance with an instruction from the system controller 72.

  The print control unit 80 has a signal processing function for performing various processing and correction processing for generating a print control signal from the image data in the image memory 74 according to the control of the system controller 72, and the generated print It is a control unit that supplies data (dot data) to the head driver 84. Necessary signal processing is performed in the print control unit 80, and the ejection amount and ejection timing of the ink droplets of the head 50 are controlled via the head driver 84 based on the image data. Thereby, a desired dot size and dot arrangement are realized.

  The print control unit 80 includes an image buffer memory 82, and image data, parameters, and other data are temporarily stored in the image buffer memory 82 when image data is processed in the print control unit 80. Also possible is an aspect in which the print controller 80 and the system controller 72 are integrated and configured with one processor.

  The head driver 84 drives the actuators 58 of the heads 12K, 12C, 12M, and 12Y for each color based on the print data given from the print control unit 80. The head driver 84 may include a feedback control system for keeping the head driving conditions constant.

  As described with reference to FIG. 1, the print detection unit 24 is a block including a line sensor, reads an image printed on the recording paper 16, performs necessary signal processing, and the like to perform a print status (whether ejection is performed, droplet ejection And the detection result is provided to the print control unit 80.

  The print controller 80 performs various corrections on the head 50 based on information obtained from the print detector 24 as necessary.

  Image data to be printed is input from the outside via the communication interface 70 and stored in the image memory 74. At this stage, RGB image data is stored in the image memory 74.

  The image data stored in the image memory 74 is sent to the print controller 80 via the system controller 72, and is converted into dot data for each ink color by the print controller 80. That is, the print control unit 80 performs processing for converting the input RGB image data into dot data of four colors of KCMY. The dot data generated by the print controller 80 is stored in the image buffer memory 82.

  The head driver 84 generates a drive control signal for the head 50 based on the dot data stored in the image buffer memory 82. By applying the drive control signal generated by the head driver 84 to the head 50, ink is ejected from the head 50. An image is formed on the recording paper 16 by controlling the ink ejection from the head 50 in synchronization with the conveyance speed of the recording paper 16.

  Various control programs are stored in the program storage unit 90, and the control programs are read and executed in accordance with instructions from the system controller 72. The program storage unit 90 may use a semiconductor memory such as a ROM or an EEPROM, or may use a magnetic disk or the like. An external interface may be provided and a memory card or PC card may be used. Of course, you may provide several recording media among these recording media. The program storage unit 90 may also be used as a recording means (not shown) for operating parameters.

  The system controller 72 controls the deaeration unit 106 that removes the dissolved gas from the gas carrying liquid 122 shown in FIG. 5 (degases the gas carrying liquid 122) via the deaeration control unit 130. That is, based on the control signal sent from the system controller 72 to the deaeration control unit 130, the deaeration control unit 130 performs control such as on / off of the deaeration unit 106 and the deaeration amount (deaeration time).

  The gas carrying liquid channel 100 is provided with a dissolved oxygen meter so that the dissolved gas concentration of the gas carrying liquid 122 becomes a predetermined value or less based on the measurement result of the dissolved oxygen meter (the dissolved oxygen concentration of the gas carrying liquid 122). The deaeration unit 106 may be controlled.

  Further, the system controller 72 controls the pump 108 that circulates the gas carrying liquid 122 shown in FIG. 5 via the pump control unit 132. The pump driver 132 controls on / off of the pump 108 and pressure (flow rate of the gas carrying liquid 122) based on a command signal sent from the system controller 72.

  When the flow velocity of the gas carrying liquid 122 is made faster than the flow velocity of the ink 120, the pressure loss caused by the circulation of the gas carrying liquid 122 causes the gas carrying liquid channel 100 (gas carrying liquid 122) to be compared with the ink channel 15 (ink 120). Pressure is lowered. As described above, the differential gas is generated between the ink 120 and the gas carrying liquid 122, so that the dissolved gas removal efficiency of the ink 120 can be improved.

  In the inkjet recording apparatus 10 configured as described above, a gas having a structure in which the ink 120 and the gas carrying liquid 122 are separated by the gas permeable film 102 between the ink storage / loading unit 14 and the head 50 (in the vicinity of the head 50). Since the exchange unit 17 is provided, the dissolved gas of the ink 120 moves to the gas carrying liquid 122 through the gas permeable film 102, and the preferred ink 120 with the dissolved gas concentration reduced is supplied to the head 50.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described. FIG. 8 is a schematic diagram illustrating a configuration of an ink supply system according to the second embodiment. FIG. 9 is a block diagram showing a schematic configuration of a control system according to the second embodiment. 8 and 9, the same or similar parts as those in FIGS. 5 and 7 are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 8, a heater 140 is provided between the deaeration unit 106 and the gas exchange unit 17 of the gas carrying liquid channel 100. The heater 140 is controlled by the heater driver 78 based on a command signal from the system controller 72 shown in FIG. 9 (FIG. 5).

  As shown in FIG. 8, by adjusting the temperature of the gas carrying liquid 122 sent from the deaeration unit 106 to the gas exchange unit 17, the temperature of the ink 120 can be adjusted by heat exchange through the gas permeable membrane 102. . By adjusting the temperature of the ink to be within a predetermined range, the viscosity of the ink 120 can be kept constant, and an ejection abnormality due to an increase in the viscosity of the ink 120 can be avoided.

  Moreover, the dissolved gas removal efficiency of the ink 120 can be improved by raising the temperature of the ink 120 in the vicinity of the gas permeable membrane 102.

  Since the temperature of the ink 120 is indirectly controlled through the gas carrying liquid 122 and the gas permeable film 102, it is possible to prevent the temperature of the ink 120 from rapidly changing due to a failure of the heater 140 or the heater driver 78.

  A mode in which a temperature sensor is provided in the ink flow path 15 or the gas carrying liquid flow path 100 and the heater 140 is controlled based on temperature information obtained from the temperature sensor is preferable. A mode in which the temperature sensor is provided in the gas exchange unit 17 or a mode in which the temperature sensor is provided in the head 50 is also possible.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. FIG. 10 is a schematic diagram illustrating a configuration of an ink supply system according to the third embodiment, and FIG. 11 is a block diagram illustrating a schematic configuration of a control system. In addition, the same code | symbol is attached | subjected to the part which is the same as that of 1st, 2nd embodiment mentioned above, or similar, and the description is abbreviate | omitted.

  In the third embodiment, a liquid containing a molybdenum complex is applied to the gas carrying liquid 122. The molybdenum complex is a compound in which a ligand is bonded around the molybdenum atom as a center. When the molybdenum complex is used as the gas carrying liquid 122, the molybdenum complex compound is dissolved in a solvent and used. For example, when water is used as the solvent, the gas carrying liquid 122 becomes a molybdenum complex aqueous solution.

  As shown in FIG. 10, the gas exchange unit 17 is provided with a light source 150 for irradiating the gas carrying liquid 122 with light. As shown in FIG. 11, the light source 150 is passed through the light source driver 152 by the system controller 72. Thus, on / off, light quantity, irradiation time, and the like are controlled.

  Molybdenum complex has the property that oxygen is easily attached when light is applied, and oxygen is easily separated when light is blocked. By irradiating the gas carrying liquid 122 with light, the gas exchange unit 17 applies the gas to the gas carrying liquid 122. Since it becomes easy to attach oxygen, it is expected that the dissolved gas removal efficiency of the ink will be improved. In the deaeration unit 106, light is blocked, so that oxygen is easily separated from the gas carrying liquid 122. Improvement of deaeration efficiency is expected.

  The portion through which the gas carrying liquid 122 flows in the gas exchange unit 17 (and the gas carrying liquid channel 100 in the vicinity of the gas exchange unit 17) is configured by a transparent or translucent member, so that the light from the light source 150 is transmitted to the gas carrying liquid 122. Can be irradiated. It should be noted that light (leakage light) from the light source 150 does not strike the circulation channel 101 (particularly in the vicinity of the deaeration unit 106) of the gas carrying liquid 122 between the deaeration unit 106 and the gas exchange unit 17. A mode in which a light-shielding member is provided is preferable.

  Next, a control example of the light source 150 is shown. When the gas exchange unit 17 or the ink flow path 15 and the gas carrying liquid flow path 100 are provided with a dissolved oxygen meter and the degassing property of the ink 120 is insufficient (when the concentration is higher than a predetermined dissolved oxygen concentration), the light source 150 is irradiated. Maximize capacity to improve the oxygen absorption capacity of the gas-carrying liquid 122.

  In addition, when the apparatus is activated or maintenance is performed, when the ink in the head 50 is sucked using the cap 64 and a large amount of ink is consumed and the deaeration of the ink 120 is insufficient, the irradiation capability of the light source 150 is increased. The maximum is controlled to improve the oxygen absorption capacity of the gas carrying liquid 122.

  When the degassing property of the ink 120 becomes good (when the concentration is lower than a predetermined dissolved oxygen concentration), the light amount of the light source 150 is reduced (or light irradiation of the light source 150 is stopped). That is, in a state where the dissolved gas concentration of the ink 120 or the gas carrying liquid 122 is small, the light amount of the light source 150 is reduced (stopped), thereby optimizing the dissolved gas removing ability of the ink 120 and the gas carrying liquid 122 and the light source 150. It is controlled to save power.

  When the dissolved oxygen concentration of the gas carrying liquid 122 in the gas exchange unit 17 exceeds a predetermined value, the light source 150 is turned off, the degassing capability of the degassing unit 106 is increased, and the dissolved gas in the gas carrying liquid 122 is removed. Controlled to increase ability.

  Alternatively, the flow rate of ink in the ink flow path (average flow rate in one job) may be calculated from the print data, and the light amount of the light source 150 may be controlled based on the ink flow rate. According to the aspect in which the light amount of the light source 150 is varied in accordance with the ink flow velocity, it is possible to optimize the dissolved gas removal ability of the ink and to save the power of the light source 150.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. FIG. 12 is a block diagram illustrating a schematic configuration of an ink supply system according to the fourth embodiment. As shown in the figure, a recovery tank 68 that stores waste ink recovered from the head 50 using a cap 64 and a gas transport liquid tank 160 that stores a gas transport liquid 122 are connected via a pump 162 and a valve 164. Communicated. In other words, the waste ink discharged during head maintenance is configured to be diverted to the gas carrying liquid 122.

  Since the gas carrying liquid 122 is always degassed, the solvent is evaporated (vaporized) to reduce the amount thereof, and it is necessary to replenish this reduced amount at an appropriate timing. A sensor for detecting the amount of liquid (water level) in the gas carrying liquid tank 160 is provided. When the amount of the gas carrying liquid 122 in the gas carrying liquid tank 160 is less than a predetermined amount, the pump 162 is operated and the valve 164 is operated. And the waste ink in the recovery tank 68 is supplied to the gas transport liquid tank 160.

  As described above, in the aspect in which the waste ink is used as the gas carrying liquid 122, it is possible to prevent the dissolved gas removing capability of the ink 120 from being lowered due to the lack of the gas carrying liquid 122 and to reduce the cost of the gas carrying liquid 122. .

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described with reference to FIGS. FIGS. 13 and 14 are diagrams showing the flow path structure of the flow path of the ink 120 and the flow path of the gas carrying liquid 122 in the gas exchange unit 17.

  In the aspect shown in FIG. 13, the flow path of the gas carrying liquid 122 is divided in the gas exchange unit 17, and a plurality of branch flow paths 200 are provided. In the embodiment shown in FIG. 14, the ink 120 flow path is divided within the gas exchange unit 17, and a plurality of branch flow paths 202 are provided.

  A gas permeable film 102 is provided on the surface constituting each branch flow path 200, 202, and the gas carrying liquid 122 (ink in the branch flow path 202) in each branch flow path 200 passes through the gas permeable film 102. The ink 120 (gas carrying liquid 122) and the gas carrying liquid 122 (ink 120) are separated from each other.

  According to this configuration, the area of the ink 120 and the gas carrying liquid 122 in contact with the gas permeable membrane 102 (surface areas of the branch flow paths 200 and 202 formed by the gas permeable membrane 102) can be increased. Dissolved gas removal efficiency is improved. A mode in which the first to fifth embodiments described above are appropriately combined is also possible.

[Application example]
Next, application examples of the first to fifth embodiments described above will be described with reference to FIG. FIG. 15 is a diagram showing a schematic structure of a head 210 according to this application example. In FIG. 15, configurations such as the pressure chamber 52 and the supply port 54 (see FIG. 4) are omitted.

  As shown in FIG. 15, a gas permeable membrane 102 is provided on the opposite side (the upper side in FIG. 15) of the common liquid chamber 55 to the nozzle 51, and further, a gas carrying liquid flow is provided on the opposite side of the gas permeable membrane 102 to the common liquid chamber 55. A path 100 is provided. That is, the gas exchange part 17 (see FIG. 5) described above is provided inside the head 210.

  Thus, according to the configuration in which the dissolved gas 124 of the ink 120 can be removed inside the head 210, the ink in the head 210 is maintained in a preferable state in which the dissolved gas is reduced. It is possible to avoid ejection abnormalities resulting from the occurrence.

  Further, in an aspect including a heater (not shown) that varies the temperature of the gas carrying liquid 122 in the head 210, the temperature of the gas carrying liquid 122 in the head 210 is controlled to control the head 210 and the ink 120 in the head 210. Temperature can be kept constant. Since the heater that varies the temperature of the gas carrying liquid 122 is also used as the heater that adjusts the temperature of the head 210, it contributes to cost reduction.

[Other Embodiments]
In the above-described embodiment, the actuator 58 joined to the wall of the pressure chamber 52 is operated to deform the pressure chamber 52 and pressurize the ink in the pressure chamber 52. However, the pressure chamber 52 includes a heater. Alternatively, a system may be applied in which the heater is operated to generate bubbles in the pressure chamber 52 and pressurize the ink in the pressure chamber 52.

  In the above embodiment, an inkjet recording apparatus using a page-wide full-line head having a nozzle row having a length corresponding to the entire width of the recording paper 16 has been described, but the scope of application of the present invention is not limited to this, The present invention can also be applied to an inkjet recording apparatus that uses a shuttle head that records an image while reciprocating a short recording head.

  In this example, the configuration including the heads 12K, 12C, 12M, and 12Y that eject ink corresponding to the four colors of KCMY is shown. However, the processing liquid that reacts with the ink on the recording paper 16 and fixes the ink is used for the recording paper. You may add the head which discharges on 16. FIG.

  In the above embodiment, an ink jet recording apparatus that forms an image on the recording paper 16 by ejecting ink from nozzles provided in the print head has been described. However, the scope of application of the present invention is not limited thereto, and other than ink such as resist. The present invention can be widely applied to an image forming apparatus that forms an image (three-dimensional shape) with a liquid, and a liquid ejecting apparatus such as a dispenser that ejects chemical liquid, water, etc. from a nozzle (ejection hole).

1 is an overall configuration diagram of an inkjet recording apparatus according to the present invention. FIG. 1 is a plan view of a main part around a printing unit of the ink jet recording apparatus shown in FIG. Plane perspective view showing structural example of print head 3A and 3B are sectional views taken along line 4-4 in FIG. Schematic diagram showing the configuration of the supply system of the ink jet recording apparatus shown in FIG. The block diagram explaining the structure of the gas exchange part shown in FIG. 1 is a principal block diagram showing the system configuration of the ink jet recording apparatus shown in FIG. Schematic diagram showing the configuration of a supply system of an ink jet recording apparatus according to a second embodiment of the present invention. The principal part block diagram which shows the system configuration | structure of the inkjet recording device which concerns on 2nd Embodiment of this invention. Schematic diagram showing the configuration of a supply system of an ink jet recording apparatus according to a third embodiment of the present invention. The principal part block diagram which shows the system configuration | structure of the inkjet recording device which concerns on 3rd Embodiment of this invention. FIG. 9 is a principal block diagram showing a system configuration of an inkjet recording apparatus according to a fourth embodiment of the present invention. The block diagram explaining the structure of the gas exchange part which concerns on 5th Embodiment of this invention. The block diagram which shows the other aspect of the gas exchange part shown in FIG. Schematic configuration diagram of a head according to an application example of the present invention

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Inkjet recording device, 15 ... Ink flow path, 17 ... Gas exchange part, 50, 210 ... Head, 55 ... Common liquid chamber, 100 ... Gas conveyance liquid flow path, 101 ... Circulation flow path, 102 ... Gas permeable film, DESCRIPTION OF SYMBOLS 120 ... Ink, 122 ... Gas carrying liquid, 106 ... Deaeration device, 108 ... Pump, 130 ... Deaeration control part, 132 ... Pump driver, 140 ... Heater, 150 ... Light source, 152 ... Light source driver, 200, 202 ... Branch Flow path

Claims (12)

A first flow path serving as a first liquid flow path;
A second flow path serving as a flow path for a second liquid having a dissolved gas concentration represented by an amount of dissolved gas per unit volume equal to or lower than the first liquid;
A gas having a gas permeable membrane that communicates with the first flow path and the second flow path and that contacts the first liquid and the second liquid and separates the first liquid and the second liquid. Exchange means,
A deaeration device comprising: Dissolved gas removal means for removing the dissolved gas of the second liquid;
Circulating means for circulating the second liquid from which the dissolved gas has been removed by the dissolved gas removing means to the gas exchange section;
The deaerator according to claim 1, further comprising:   The deaeration apparatus according to claim 1, further comprising a temperature adjusting unit that adjusts a temperature of the second liquid. The second liquid includes a liquid containing a molybdenum complex;
4. A deaeration device according to claim 1, further comprising a light irradiation means for irradiating light to the second liquid in at least a region in contact with the gas permeable membrane. The gas exchange unit has a plurality of first branch flow paths through which the first liquid flows,
5. The deaeration device according to claim 1, wherein the gas permeable membrane is provided in a portion of the first branch channel that contacts the second liquid. The gas exchange section has a plurality of second branch flow paths through which the second liquid flows,
5. The deaeration device according to claim 1, wherein the gas permeable membrane is provided in a portion of the second branch channel that contacts the first liquid.   The deaeration device according to any one of claims 1 to 6, further comprising a flow rate varying unit that varies a relative flow rate between the first liquid and the second liquid.   The degassing according to any one of claims 1 to 7, wherein the dissolved gas concentration in the saturated state of the second liquid is equal to or higher than the dissolved gas concentration in the saturated state of the first liquid. apparatus. A liquid discharge head for discharging a first liquid onto a medium,
A liquid discharge head comprising the deaeration device according to claim 1. A liquid discharge head for discharging the first liquid onto the medium;
A liquid ejecting apparatus comprising the deaeration device according to claim 1.   The first liquid is brought into contact with a second liquid having a dissolved gas concentration represented by a dissolved gas amount per unit volume equal to or lower than the first liquid through a gas permeable membrane. The dissolved gas removal method characterized by removing the dissolved gas.   The dissolved gas removal method according to claim 11, wherein the saturated dissolved gas concentration of the second liquid is equal to or higher than the saturated dissolved gas concentration of the first liquid.

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