JP5233073B2 - Ink jet recording apparatus and ink supply method thereof - Google Patents

Description

  The present invention relates to an ink jet recording apparatus and an ink supply method thereof.

  In recent years, the inkjet recording method can easily and inexpensively create an image, and thus has been applied to various printing fields such as photographs, various printing, marking, and special printing such as a color filter.

  Ink jet printers have a serial printing method in which printing is performed while the recording head is reciprocated in the paper width direction and the paper is conveyed intermittently, and ejection heads are arranged throughout the paper width direction to fix the recording head. There is a line head system that performs printing. The recording head is supplied with ink directly from an ink tank or through an ink tube. The recording head has problems such as clogging of the ejection head of the recording head during ink ejection and ejection failure due to increased ink viscosity.

  In view of this, a method has been proposed in which ink is pumped from the ink tank when the recording head is cleaned and recovered, and foreign matter such as dust and air bubbles in the recording head is ejected together with ink from the ejection port (see, for example, Patent Document 1). ).

In addition, a recording head connecting pipe that communicates between the recording head and an ink tank that supplies ink to the recording head is provided with a bypass ink flow path that can be freely opened and closed. A method has been proposed in which the flow rate of ink flowing to the ink ejection head is increased, the recording head is sealed with a cap, sucked with a pump, and bubbles are discharged quickly and reliably (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 3-184872 JP-A-6-340090

  However, in the prior art, since the ink flow path is made of a tank or tube made of a hard material, when the ink is pumped into the flow path filled with ink, the flow path and the inside of the recording head are suddenly pressurized. There was a risk of ink leakage from the joint of the flow path.

  In addition, in order to switch the flow path to the print head and supply ink via a bypass with a low flow resistance, both the flow paths need to be filled with ink, and the print head is sealed with a cap. In order to suck, a complicated mechanism was required.

  Therefore, the present invention discharges dust, bubbles, etc. existing in the ink flow path and the recording head with a simple structure reliably and quickly without damaging the ink flow path and the recording head and without causing ink leakage. It is an object of the present invention to provide an ink jet recording apparatus and an ink supply method thereof.

The object of the present invention can be achieved by the following constitution.
(1)
A recording head having a plurality of ejection openings for ejecting ink and forming an image on a recording medium with the ejected ink;
An ink jet recording apparatus having an ink supply unit for supplying ink to the recording head;
An ink tank for storing ink;
A pump for pumping the ink stored in the ink tank to the recording head;
An intermediate tank provided between the pump and the recording head and having a flexible bag for storing ink pumped by the pump;
An ink flow path provided in parallel with the intermediate tank between the pump and the recording head to bypass the intermediate tank;
A plurality of valves disposed above and downstream of the intermediate tank and in the ink flow path;
Possess a control unit that controls so that the supply of ink is made through the opening and closing said plurality of valves the intermediate tank or the ink passage,
When the ink is supplied through the ink flow path, the control unit controls the upstream valve of the intermediate tank to be in a closed state and the downstream valve to be in an open state .
(2)
One end of the ink flow path is connected to the flow path between the upstream valve and the pump, and the other end of the ink flow path is on the flow path between the downstream valve and the recording head. The inkjet recording apparatus according to (1), wherein the inkjet recording apparatus is connected to the inkjet recording apparatus.
(3)
(1) or (2), wherein the control unit controls the downstream valve to be in a closed state after a predetermined time in which overpressure is suddenly generated in the recording head from the start of ink supply. The ink jet recording apparatus described.
(4)
The ink jet according to (1) or (2), wherein the control unit controls the downstream valve to a closed state after supplying a predetermined ink amount determined based on a rotation speed of the pump. Recording device.
(5)
The ink is an inkjet ink containing at least water, a water-soluble organic solvent, and a pigment, and the water content is 10% by mass or more and less than 50% by mass of the total ink mass, and the most of the water-soluble organic solvents The SP value of a large amount of the water-soluble organic solvent is 16.5 or more and less than 24.6, and the content of the water-soluble organic solvent having the SP value of 16.5 or more and less than 24.6 is 30 of the total ink mass. The inkjet recording apparatus according to any one of (1) to (4), wherein the inkjet recording apparatus is not less than mass%.
(6)
A recording head having a plurality of ejection openings for ejecting ink and forming an image on a recording medium with the ejected ink;
An ink supply method for supplying ink to the recording head, and an ink supply method for an ink jet recording apparatus,
An ink tank for storing ink;
A pump for pumping the ink stored in the ink tank to the recording head;
An intermediate tank provided between the pump and the recording head and having a flexible bag for storing ink pumped by the pump;
An ink flow path provided in parallel with the intermediate tank between the pump and the recording head to bypass the intermediate tank;
A plurality of valves disposed above and downstream of the intermediate tank and in the ink flow path;
Have a, and a control step of controlling so that the supply of ink is made through the opening and closing said plurality of valves the intermediate tank or the ink passage,
In the ink jet recording apparatus, the control step controls the upstream valve of the intermediate tank to be closed and the downstream valve to be opened when ink is supplied through the ink flow path. Supply method.
(7)
One end of the ink flow path is connected to the flow path between the upstream valve and the pump, and the other end of the ink flow path is on the flow path between the downstream valve and the recording head. The ink supply method for an ink jet recording apparatus according to (6), wherein the ink supply method is connected to the ink jet recording apparatus.
(8)
(6) or (7), wherein the control step controls the valve on the downstream side to be closed after a predetermined time when the overpressure is suddenly generated in the recording head from the start of ink supply. An ink supply method for the ink jet recording apparatus according to claim 1.
(9)
The inkjet control according to (6) or (7), wherein the control step controls the downstream valve to a closed state after supplying a predetermined amount of ink determined based on the number of rotations of the pump. Ink supply method for recording apparatus.

According to the present invention, since the supplied ink is once received as a buffer by the flexible bag, a sudden positive pressure is not applied to the flow path, so that the risk of ink leakage from the flow path can be avoided. .
In addition, the flexible bag is originally used for setting the head value during ink jet recording, and only a valve and a bypass channel are added as the channel configuration, so it can be handled at low cost and with a simple structure. It becomes.

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

  FIG. 1 is a cross-sectional view of an ink jet recording apparatus using an ink supply unit according to the present invention.

  A denotes the entire inkjet recording apparatus, and 3 denotes a paper discharge unit on which a recording medium (paper) P on which an image is recorded is discharged and stacked. The ink jet recording apparatus A includes a head unit 50, an ink tank 11, an intermediate tank 31, a transport unit 2, and a paper feeding unit 1 in which a recording medium P is housed, which constitutes a liquid ejecting apparatus according to the invention.

  The control unit 4 operates various means constituting the ink jet recording apparatus according to a program stored in the CPU, for example, reads image information of a document, or from an external information device via an interface (not shown). Printer function that executes a series of image information recording control that inputs image information etc., stores that information, and records and outputs it on a recording medium, and adjustment and maintenance of various means so that the printer function can be executed reliably Maintenance function to perform etc.

  The head unit 50, which will be described in detail later, is, for example, a head having a plurality of ejection openings for ejecting each ink of cyan (C), magenta (M), yellow (Y), and black (BK). The units are provided for four colors. Further, although not shown, for example, a drive circuit for performing an ink discharge operation corresponding to each head unit is integrally incorporated.

  The maintenance stand 60 is provided with a cap that covers the vicinity of the discharge port so that dust or dust adheres to the discharge port of the head unit 50 or the ink does not dry and become clogged when the printing operation is interrupted for a while. Recover the clogged state by installing or cleaning the discharge port before starting the next print operation after suspending the print operation or at regular intervals. Thus, a normal ink ejection operation can be performed.

  For transporting the recording medium P, the recording medium P stored in the paper feeding unit 1 is taken out one by one by the feed roller R1. The pair of rollers R2 sends the taken recording medium P in the direction of the pair of rollers R3. The recording medium P sandwiched between the rollers R3 is further sent to the transport unit 2.

  The recording medium P transported via the transport unit 2 faces the head unit 50 and records an image while being transported at a constant speed.

  Thereafter, a paper discharge conveyance operation is executed, and the recording medium P on which an image is recorded is sandwiched by a pair of rollers R8 and discharged to the paper discharge unit 3.

  FIG. 2 is a schematic diagram showing the configuration of the ink supply unit and the head recovery means according to the present invention. The ink supply and head recovery operation, which are maintenance functions, will be described with reference to FIG.

  Usually, the back pressure required for the head unit 50 is set by the water head difference between the intermediate tank 31 and the head unit 50 by a flexible bag.

  At the time of recording on the recording medium, ink is supplied from the intermediate tank 31 to the individual head (recording head) 51 via the common channel 34, the distributor 41, and the individual head supply channel 45. Ink supply to the intermediate tank 31 is carried out from the ink pack (ink tank) 11 through the supply flow path 21 to the intermediate tank 31 by the liquid feed pump (pump) 22 when it is determined by the swell detection sensor 32 that supply is required. Supply a predetermined amount of liquid. The distributor 41 provided in the middle of the common flow path 34 is provided to equalize the flow path resistance of the ink supplied to the individual heads 51 constituting the head unit 50, and serves as a short-time supply source.

  During the head recovery operation, the pressure is switched to a pressure channel (ink channel) 24 that bypasses the intermediate tank 31, the ink is fed by the liquid feed pump 22, and the individual head 51 selected by the individual head valve 46 is discharged. Extrude ink from the outlet to discharge dust and bubbles. After the ink is pushed out, the ejection port surface is wiped by the wiper blade 61. An air vent channel 71 having an air vent pump 73 is piped from the upper part of the distributor 41, and dust and air bubbles are discharged from this channel when the ink is initially introduced and when dust and air bubbles are mixed into the ink supply channel. To do. The pressure sensor 43 is used to detect overpressure during pressure extrusion.

  FIG. 3 is a schematic diagram showing the configuration of the head cleaning unit provided on the maintenance table 60. A plurality of wiper blades 61 corresponding to the plurality of individual heads 51 of the head unit 50 are provided. Dust and bubbles in the ink flow path (pressurization flow path 24, common flow path 34, distributor 41) and the individual head 51 are discharged together with the discharged ink 51b discharged from the discharge port by pressure extrusion when the head is recovered. . Thereafter, the wiper blade 61 is moved in the ejection port arrangement direction (the direction of the arrow 62a) in FIG. 3 to wipe away the discharged ink 51b.

  FIG. 4 is a schematic diagram illustrating the configuration of the ink supply unit during recording. At the time of recording, since the pressurization valve 25 of FIG. 2 is closed, ink does not flow into the pressurization flow path 24. Therefore, in FIG. 4, the pressurization flow path 24 is omitted for the sake of clarity.

  When the ink in the intermediate tank (flexible bag) 31 falls below a predetermined amount due to ink ejection from the head knit during recording and the bulge detection sensor 32 is turned on, the liquid feed pump is turned on and the ink tank (ink pack) 11 is turned on. Ink is supplied to the intermediate tank 31. At that time, the pulsating flow of ink supply is suppressed by the intermediate tank 31 and does not affect the head unit 50.

  FIG. 5 is a flowchart of the procedure of the ink supply operation (water head value setting). At the time of recording, the replenishment valve 23 and the supply valve 33 are open. The trigger is started when the ink in the intermediate tank (flexible bag) 31 becomes a predetermined amount or less and the swell detection sensor 32 is turned on.

  In step S1, it is determined whether the bulge sensor 32 is on. If it is on (step S1: YES), that is, if the ink storage amount in the intermediate tank 31 is less than or equal to the predetermined amount, the process proceeds to step S2, and is off (step S1: NO), that is, the ink in the intermediate tank 31 When the storage amount exceeds the predetermined amount, the process proceeds to step S3.

  In step S2, the liquid feed pump 22 is turned on. Ink is supplied from the ink tank 11 to the intermediate tank 31.

  In step S3, the liquid feed pump 22 is turned off.

  FIG. 6 is a schematic diagram illustrating the configuration of the ink supply unit during the recovery operation. During the head recovery operation, the pressure is switched to a pressure flow path (ink flow path) 24 that bypasses the intermediate tank 31, the ink is fed by the liquid feed pump 22, and the ejection port of the individual head 51 selected by the individual head valve 46. Extrude more ink and discharge dust and bubbles. However, when ink is pumped into a flow path filled with ink, the flow path and the inside of the recording head are suddenly pressurized, and there is a risk of causing ink leakage from a joint of the flow path.

  FIG. 7 is a schematic diagram illustrating the configuration of the ink supply unit during the recovery operation according to the present embodiment.

  An intermediate tank (flexible bag) 31 is suspended from the pressurized flow path 24.

  FIG. 8 is a flowchart showing the procedure of the recovery operation according to the present embodiment.

  The present embodiment of the flowchart of FIG. 8 will be described with reference to FIG.

  This flowchart starts with a head recovery operation command as a trigger.

  In step S11, the supply valve 23 is closed and the supply valve 33 is opened.

  In step S12, the individual head valve 44 that does not perform the head recovery operation is closed.

  In step S13, the pressurizing valve 25 is opened.

  In step S14, the liquid feeding pump is turned on and liquid feeding is started.

  In step S15, a predetermined time T1 is measured. During this time, sudden overpressure is absorbed by the intermediate tank 31 and does not damage the flow path. When liquid is fed and the inside of the head becomes positive pressure, ink starts to be pushed out. Here, in the case of the ink supply unit in the form of FIG. 6, the predetermined time T1 is a time during which overpressure is suddenly generated in the flow path and the recording head. Although it depends on the configuration, for example, it takes about 1.5 seconds.

  A predetermined ink amount may be measured instead of the predetermined time T1. The predetermined ink amount is determined by counting the number of rotations of the liquid feed pump. For example, using a liquid feed pump that delivers 0.1 ml of ink after one rotation, when the predetermined ink amount is 3 ml, the predetermined ink amount is reached at 30 rotations. That is, it is determined whether the count number has reached 30.

  In step S16, the supply valve 33 is closed. Here, the intermediate tank 31 is separated from the pressurizing flow path 24.

  In step S17, the liquid feed pump 22 is turned off.

  In step S18, a predetermined time T2 is measured. During this time, the ink continues to be pushed out from the ejection port. Dust and bubbles in the ink flow path and the head are discharged along with the ink. Eventually, the ink is pushed out from the ejection port, the internal pressure in the head is lowered, and the ink dripping from the ejection port is settled. Here, the predetermined time T2 is a time from when the liquid feed pump is turned off until ink dripping is settled from the ejection port. Although it depends on the configuration, for example, it takes about several seconds.

  In step S19, the pressurizing valve 25 is closed.

  In step S20, the individual head valve 46 is opened.

  In step S21, the supply valve 33 and the supply valve 23 are opened.

  In step S22, the ink supply operation (head value setting) shown in FIG. 5 is performed.

  In step S23, the discharged ink 51b is wiped by the head cleaning unit shown in FIG.

  Next, an example of ink used in the ink jet recording apparatus will be described.

  Ink jet ink (hereinafter, also simply referred to as ink) contains at least water, a water-soluble organic solvent, and a pigment. Here, the water-soluble organic solvent is not particularly limited as long as it can be mixed with water. Two or more water-soluble organic solvents can be used in combination. However, in order to suppress the occurrence of cavitation when continuously emitting light, the SP value of the most water-soluble organic solvent among the water-soluble organic solvents is 16.5 or more and less than 24.6, It is preferable that the content of the water-soluble organic solvent having an SP value of 16.5 or more and less than 24.6 is 30% by mass or more of the total ink mass. Since this solvent composition contains a large amount of a water-soluble organic solvent having a higher hydrophobicity than water, the solubility of the entire ink is high, and as a result, cavitation is unlikely to occur during continuous emission.

  The solvent solubility parameter (SP value) is a value expressed by the square root of the molecular cohesive energy. F. Fedors, Polymer Engineering Science, 14, p147 (1974). The unit is (MPa) 1/2, and refers to the value at 25 ° C.

  Hereinafter, examples of water-soluble organic solvents having an SP value of 16.5 or more and less than 24.6 are shown together with the SP value. Needless to say, the present ink is not limited to this.

Ethylene glycol monomethyl ether (SP value: 24.5)
Ethylene glycol monoethyl ether (23.5)
Ethylene glycol monobutyl ether (22.1)
Ethylene glycol monoisopropyl ether (22.3)
Diethylene glycol monomethyl ether (23.0)
Diethylene glycol monoethyl ether (22.4)
Diethylene glycol monobutyl ether (21.5)
Diethylene glycol diethyl ether (16.8)
Triethylene glycol monomethyl ether (22.1)
Triethylene glycol monoethyl ether (21.7)
Triethylene glycol monobutyl ether (21.1)
Propylene glycol monomethyl ether (23.0)
Propylene glycol monophenyl ether (24.2)
Dipropylene glycol monomethyl ether (21.3)
Tripropylene glycol monomethyl ether (20.4)
1,3-dimethyl-2-imidazolidinone (21.8)
In this ink, in addition to the water-soluble organic solvent having an SP value of 16.5 or more and less than 24.6, conventionally known various water-soluble organic solvents can be used in combination.

  Examples of the water-soluble organic solvent preferably used as the solvent to be used in combination include alcohols (for example, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol, pentanol, hexanol, cyclohexane). Hexanol, benzyl alcohol, etc.), polyhydric alcohols (for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, Thiodiglycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanedio , 1,2-pentanediol, 1,2-hexanediol, 1,2,6-hexanetriol, etc.), amines (eg, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine) , Morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, pentamethyldiethylenetriamine, tetramethylpropylenediamine, etc.), amides (for example, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, etc.), heterocyclic rings (for example, 2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone, 2-oxazolidone, etc.), sulfoxides For example, dimethyl sulfoxide, etc.), sulfones (e.g., sulfolane), urea, acetonitrile, and acetone.

  As the pigment that can be used in the present ink, conventionally known pigments can be used without particular limitation, and any of water-dispersible pigments, solvent-dispersible pigments, and the like can be used, for example, organic pigments such as insoluble pigments and lake pigments, An inorganic pigment such as carbon black can be preferably used. This pigment is present in a dispersed state in the ink, and the dispersion method may be any of self-dispersion, dispersion using a surfactant, polymer dispersion, and microcapsule dispersion. Dispersion is particularly preferred from the standpoint of fixability.

  The insoluble pigment is not particularly limited. Dioxazine, thiazole, phthalocyanine, diketopyrrolopyrrole and the like are preferable.

  Specific pigments that can be preferably used include the following pigments.

  Examples of the magenta or red pigment include C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. Pigment red 202, C.I. I. Pigment red 222, C.I. I. Pigment violet 19 and the like.

  Examples of the pigment for orange or yellow include C.I. I. Pigment orange 31, C.I. I. Pigment orange 43, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 15: 3, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 128, C.I. I. Pigment yellow 94, C.I. I. And CI Pigment Yellow 138.

  Examples of the pigment for green or cyan include C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16, C.I. I. Pigment blue 60, C.I. I. And CI Pigment Green 7.

  Examples of black pigments include C.I. I. Pigment black 1, C.I. I. Pigment black 6, C.I. I. Pigment black 7 and the like.

  The average particle size of the dispersed state of the pigment contained in the ink is preferably 50 nm or more and less than 200 nm. When the average particle size of the pigment dispersion is less than 50 nm or 200 nm or more, the stability of the pigment dispersion tends to deteriorate, and the storage stability of the ink tends to deteriorate.

  The particle size of the pigment dispersion can be determined by a commercially available particle size measuring instrument using a dynamic light scattering method, an electrophoresis method, or the like. Accurate and often used.

  The pigment to be used is preferably used after being dispersed by a disperser together with a dispersant and other additives necessary for various desired purposes. As the disperser, a conventionally known ball mill, sand mill, line mill, high-pressure homogenizer, or the like can be used. In particular, the particle size distribution of the ink produced by dispersion with a sand mill is sharp and preferable. The material of the beads used for sand mill dispersion is preferably zirconia or zircon from the viewpoint of contamination of bead fragments and ionic components. Furthermore, the bead diameter is preferably 0.3 mm to 3 mm.

  In the present ink, it is preferable to use a polymer dispersant in the dispersion.

  The polymer dispersant has a polymer component having a molecular weight of 5000 or more and 200000 or less. The polymer dispersant is selected from styrene, styrene derivatives, vinyl naphthalene derivatives, acrylic acid, acrylic acid derivatives, maleic acid, maleic acid derivatives, itaconic acid, itaconic acid derivatives, fumaric acid and fumaric acid derivatives. Examples thereof include a block copolymer comprising at least one kind of monomer, a random copolymer and salts thereof, polyoxyalkylene, and polyoxyalkylene alkyl ether.

  In the case of an acidic polymer dispersant, it is preferably added after neutralization with a neutralizing base. Here, the neutralizing base is not particularly limited, but is preferably an organic base such as ammonia, monoethanolamine, diethanolamine, triethanolamine, or morpholine.

  Moreover, it is preferable that it is 10-100 mass% with respect to a pigment as addition amount of a polymer dispersing agent.

  In this ink, in addition to the above description, if necessary, various known additions may be made depending on the purpose of improving the emission stability, compatibility with the print head and ink cartridge, storage stability, image storage stability, and other various performances. Agents, for example, polysaccharides, viscosity modifiers, specific resistance regulators, film forming agents, ultraviolet absorbers, antioxidants, anti-fading agents, antifungal agents, rust inhibitors, etc. can be appropriately selected and used, For example, oil droplet fine particles such as liquid paraffin, dioctyl phthalate, tricresyl phosphate, silicone oil, ultraviolet absorbers described in JP-A-57-74193, JP-A-57-87988, and JP-A-62-261476, 57-74192, 57-87989, 60-72785, 61-146591, JP-A-1-95091 and 3-13376, etc. Anti-fading agents, fluorescent whitening agents described in JP-A-59-42993, JP-A-59-52689, JP-A-62-280069, JP-A-61-228771, JP-A-4-219266, etc. be able to.

  The ink having the above-described structure preferably has an ink surface tension of 25 to 40 mN / m at 25 ° C., more preferably 25 to 35 mN / m, and still more preferably 30 to 35 mN / m. . The ink viscosity is preferably 1 to 40 mPa · s at 25 ° C., more preferably 5 to 40 mPa · s, and still more preferably 5 to 20 mPa · s.

  Of course, the ink jet recording apparatus is not limited to the ink described above.

  The detailed configuration and detailed operation of each component constituting the ink jet recording apparatus can be changed as appropriate without departing from the spirit of the present invention.

It is sectional drawing of the inkjet recording device using the ink supply part which concerns on this invention. It is a schematic diagram which shows the structure of the ink supply part and head recovery | restoration means which concern on this invention. It is a schematic diagram which shows the structure of a head cleaning part. FIG. 4 is a schematic diagram illustrating a configuration of an ink supply unit during recording. It is a flowchart of the procedure of ink replenishment operation | movement (water head value setting). It is a schematic diagram which shows the structure of the ink supply part at the time of recovery operation | movement. It is a schematic diagram which shows the structure of the ink supply part at the time of the recovery operation | movement which concerns on this Embodiment. It is a flowchart which shows the procedure of the recovery operation | movement which concerns on this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper feed part 4 Control part 10 Ink supply part 11 Ink tank (ink pack)
DESCRIPTION OF SYMBOLS 22 Liquid feed pump 23 Supply valve 24 Pressurization flow path 25 Pressurization valve 31 Intermediate tank 32 Swelling detection sensor 33 Supply valve 46 Individual head valve 50 Head unit 51 Individual head 61 Wiper blade

Claims (9)

A recording head having a plurality of ejection openings for ejecting ink and forming an image on a recording medium with the ejected ink;
An ink jet recording apparatus having an ink supply unit for supplying ink to the recording head;
An ink tank for storing ink;
A pump for pumping the ink stored in the ink tank to the recording head;
An intermediate tank provided between the pump and the recording head and having a flexible bag for storing ink pumped by the pump;
An ink flow path provided in parallel with the intermediate tank between the pump and the recording head to bypass the intermediate tank;
A plurality of valves disposed above and downstream of the intermediate tank and in the ink flow path;
Possess a control unit that controls so that the supply of ink is made through the opening and closing said plurality of valves the intermediate tank or the ink passage,
When the ink is supplied through the ink flow path, the control unit controls the upstream valve of the intermediate tank to be in a closed state and the downstream valve to be in an open state . One end of the ink flow path is connected to the flow path between the upstream valve and the pump, and the other end of the ink flow path is on the flow path between the downstream valve and the recording head. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus is connected to the inkjet recording apparatus. Wherein, according to claim 1 or 2, wherein the controller controls the downstream side of the valve after a predetermined time rapidly overpressure is generated from the start of the supply of the ink in the recording head in the closed state Inkjet recording device. Wherein the control unit, an ink jet recording apparatus according to claim 1 or 2, wherein the downstream side of the valve controlling the closed state after supplying a predetermined amount of ink is determined based on the rotational speed of the pump . The ink is an inkjet ink containing at least water, a water-soluble organic solvent, and a pigment, and the water content is 10% by mass or more and less than 50% by mass of the total ink mass, and the most of the water-soluble organic solvents The SP value of a large amount of the water-soluble organic solvent is 16.5 or more and less than 24.6, and the content of the water-soluble organic solvent having the SP value of 16.5 or more and less than 24.6 is 30 of the total ink mass. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus is at least mass%. A recording head having a plurality of ejection openings for ejecting ink and forming an image on a recording medium with the ejected ink;
An ink supply method for supplying ink to the recording head, and an ink supply method for an ink jet recording apparatus,
An ink tank for storing ink;
A pump for pumping the ink stored in the ink tank to the recording head;
An intermediate tank provided between the pump and the recording head and having a flexible bag for storing ink pumped by the pump;
An ink flow path provided in parallel with the intermediate tank between the pump and the recording head to bypass the intermediate tank;
A plurality of valves disposed above and downstream of the intermediate tank and in the ink flow path;
Have a, and a control step of controlling so that the supply of ink is made through the opening and closing said plurality of valves the intermediate tank or the ink passage,
In the ink jet recording apparatus, the control step controls the upstream valve of the intermediate tank to be closed and the downstream valve to be opened when ink is supplied through the ink flow path. Supply method. One end of the ink flow path is connected to the flow path between the upstream valve and the pump, and the other end of the ink flow path is on the flow path between the downstream valve and the recording head. The ink supply method for an ink jet recording apparatus according to claim 6, wherein the ink supply method is connected to the ink jet recording apparatus. The control process of claim 6 or 7, wherein the controller controls the downstream side of the valve after a predetermined time rapidly overpressure is generated from the start of the supply of the ink in the recording head in the closed state Ink supply method for ink jet recording apparatus. 8. The ink jet recording apparatus according to claim 6 , wherein the control step controls the downstream valve to a closed state after supplying a predetermined ink amount determined based on a rotation speed of the pump. Ink supply method.

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