JP4944566B2 - Inkjet recording device - Google Patents

Description

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

  An ink jet recording method that records ink on a recording medium such as recording paper by ejecting ink from an ejection port has been widely adopted in recent years because it can perform high-density and high-speed recording operations with a low-noise non-impact recording method. ing.

  A general ink jet recording apparatus includes means for driving a carrier on which an ink jet recording head is mounted, transport means for transporting a recording medium, control means for controlling these, and the like. In addition, in order to generate energy for ejecting ink from the ejection port of the ink jet head, there are those that pressurize the ink using an electromechanical transducer such as a piezo element and those that emit heat by irradiating electromagnetic waves such as a laser. is there. Further, there are those that foam by heat generation, and those that heat and foam a liquid by an electrothermal transducer element having a heating resistor.

  Among them, an ink jet recording apparatus that discharges ink droplets using thermal energy can perform high-resolution recording because the nozzles can be arranged at high density. In particular, an ink jet head using an electrothermal transducer element as an energy generating element can be easily downsized. Also, by applying IC technology and micro-machining technology, which have made remarkable progress in technology and improved reliability in the recent semiconductor manufacturing field, by fully utilizing the advantages, high-density mounting is easy and the manufacturing cost is low. it can.

  Some ink jet recording apparatuses using such an ink jet recording head include a detachable main tank for supplying ink to the recording head. In such a recording apparatus, a mounting portion for receiving the mounting of the main tank and supplying ink to the recording head is provided (for example, Patent Document 1). When the main tank has a hermetically sealed structure, in order to alleviate the increase in negative pressure in the main tank due to ink supply, the mounting part is a hollow for air communication in order to introduce air corresponding to the amount of ink supplied. A member such as a needle is arranged to be able to enter the tank. Further, in relation to this member, an ink chamber capable of storing ink is provided between the portion that enters the tank and the air introduction portion. This functions as a buffer that prevents the ink that has flowed out through the member from leaking to the outside due to expansion of the air present in the main tank due to environmental changes, for example, temperature rise, and the increase in the internal pressure (hereinafter referred to as the buffer). This function is called a buffer chamber).

Japanese Patent No. 2929804

  By the way, there is a case where it is desired to move the recording apparatus to another place after the main tank is once installed and the recording apparatus is used. At this time, in order to prevent ink in the main tank from leaking into the apparatus, the moving operation is generally performed after the main tank is removed.

  However, even when the main tank is removed, the ink discharged into the buffer chamber may remain here. Then, depending on the posture of the recording apparatus during the moving operation, the residual ink may leak to the outside. In addition, even if the members before and after the buffer chamber have a narrow cross section, ink may leak due to environmental temperature changes.

  The present invention has been made from such a viewpoint, and an object thereof is to prevent ink leakage even when the apparatus is moved with the main tank removed.

In order to solve the above problems, the present invention provides a recording head that performs recording by ejecting ink, an ink tank that contains ink supplied to the recording head and is detachable from the apparatus body, and is connected to the ink tank. And a supply unit for supplying the ink stored in the ink tank to the recording head, and for storing the ink flowing out from the ink tank as the air in the ink tank expands in communication with the ink tank. In an ink jet recording apparatus comprising a storage section and an air communication section disposed in the storage section, the ink is forcibly discharged from the recording head when the ink tank is removed from the apparatus main body. A control means for moving the ink stored in the storage section to the ink tank by setting the negative pressure in the tank; And butterflies.

  Furthermore, the present invention resides in an ink jet recording apparatus provided with the above ink supply apparatus.

  According to the above configuration, the ink stored in the chamber can be transferred into the ink tank prior to removing the ink tank. As a result, even if the main tank is removed and the apparatus is moved, ink does not leak from the ink supply apparatus.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a perspective view showing a schematic configuration of an ink jet recording apparatus according to the first embodiment of the present invention.

  Reference numeral 201 denotes a recording head, 202 denotes a carriage, 203 denotes a conveyance roller, 204 denotes a main tank, 205 denotes an ink supply unit, 206 denotes an ink supply tube, and 207 denotes a recovery unit. S is a recording medium, which can be general recording paper (plain paper), special paper, an OHP film, or the like.

  In the ink jet recording apparatus according to the present embodiment, the recording head 201 mounted on the carriage 202 is moved (main scanning) in accordance with data such as characters, symbols, and images from the recording head 201 in synchronization with the movement. Ink is selectively ejected. Further, after such main scanning, the recording medium S is conveyed by a predetermined pitch (sub-scanning) by the conveying roller 203. Characters, symbols, images, and the like are formed on the recording medium S by alternately repeating these main scanning and sub-scanning.

  The carriage 202 on which the recording head 201 is mounted is slidably supported by two guide rails 250 extending in the main scanning direction, and is reciprocated by driving means such as a motor (not shown). In addition, the recording medium S crosses the moving direction (main scanning direction) of the carriage 202 while maintaining a certain distance from the surface (ejection surface) on which the ink ejection ports of the recording head 201 are provided by the transport roller 203. It is conveyed in the direction of arrow A.

  Here, the recording head 201 has a plurality of ejection port arrays for ejecting inks of different colors. Corresponding to the color of ink ejected from the recording head 201, a plurality of ink tanks (hereinafter referred to as main tanks) 204 as independent ink supply sources are detachably attached to the ink supply unit 205. The ink supply unit 205 and the recording head 201 are connected by a plurality of ink supply tubes 206 corresponding to the ink colors. The main tank 204 is mounted on the ink supply unit 205 and can supply the ink of each color stored in the main tank 204 to each ejection port array of the recording head 201 independently.

  A recovery unit 207 is disposed so as to face the ejection surface of the recording head 201 in a non-recording area that is an area within the reciprocating movement range of the recording head 201 and outside the passing range of the recording medium S. The recovery unit 207 includes a cap 207a supported so as to be movable up and down, for example, and can perform capping by raising the cap when facing the discharge surface. Then, by capping the recording apparatus during non-recording, it is possible to prevent evaporation of the ink solvent from the ejection port of the recording head 201 and to protect the recording head. In addition, by generating negative pressure in the cap with the recording head capped, foreign matter that is a cause of defective ejection that causes clogging of the ejection port such as thickened ink, dust, and bubbles in the ejection port is discharged (suction) ) By sucking and discharging the foreign matter that is the cause of the discharge failure in the discharge port, a recovery process for recovering or maintaining the discharge performance in a good state can be performed.

  FIG. 2 is a diagram for explaining a detailed configuration of the ink jet recording apparatus shown in FIG. 1, particularly regarding the ink system. For the sake of brevity, only one ink system among a plurality of ink colors is described in this figure.

  In the present embodiment, the ejection port 201g of the recording head 201 is formed as one end of a fine nozzle. Without having a valve mechanism, the nozzle is filled with ink by capillary force to form an ink meniscus at the ejection port. On the other hand, by applying a negative pressure that balances the meniscus holding force at the ejection port to the nozzle, ink leakage from the ejection port and air ingress from the atmosphere are eliminated. A discharge energy generating element in the form of an electrothermal conversion element (heater) is disposed in the vicinity of the discharge port 201g of the nozzle. The ink can be pushed out (discharged) from the discharge port 201g by causing film boiling in the ink by the driving. After this ejection operation, the ink moves from the main tank 204 through the tube 206 as needed due to the capillary force of the nozzle, and the nozzle is again filled with ink.

  Inside the recording head 201, there is provided a flow path 201f in which a fine mesh structure filter 201c is arranged to prevent dust and bubbles from moving from the upstream side of the ink supply system to the ejection port 201g. Yes. A sub tank 201b that stores a certain amount of ink supplied from the main tank 204 via the tube 206 is disposed on the upstream side of the filter 201c.

  The main tank 204 and the supply base (supply unit) 205 are obtained by attaching two hollow needles 205a and 205b fixed to the supply base 205 to liquid connectors 204a and 204b provided on the bottom surface of the main tank 204, respectively. Join. The hollow needles 205a and 205b have their respective tips penetrating into the main tank 204 via the liquid connectors 204a and 204b. The liquid connector may have a rubber plug that accepts insertion of a hollow needle, for example. The other end of the hollow needle 205a is connected to the tube 206 via a liquid path 205d, a shut-off valve 210 and a liquid path 205c, which will be described later, so that ink can be supplied to the recording head 201. On the other hand, the other end of the hollow needle 205b is connected to a buffer chamber 205f provided inside the supply base 205, and this buffer chamber 205f is open to the atmosphere via the atmosphere communication port 205g.

  As the ink in the main tank 204 is consumed as the recording head 201 ejects ink, the negative pressure inside the main tank 204 increases. In response to this, the atmosphere corresponding to the amount of ink supplied to the recording head 210 side is introduced into the main tank 204 through the atmosphere communication port 205g, the buffer chamber 205f, and the hollow needle 205b. Thereby, the negative pressure in the main tank 204 is eliminated, and stable ink supply to the recording head 201 is ensured.

  On the other hand, when an environmental change (for example, an increase in environmental temperature) occurs, when the air present in the main tank 204 expands, the ink in the main tank 204 flows out to the buffer chamber 205f through the hollow needle 205b. Here, when the volume of air existing in the ink tank 204 is V, the volume ΔV that expands when the environmental temperature rises by Δt ° C. is ΔV = V × Δt / 273. Accordingly, ink corresponding to ΔV flows into the buffer chamber 205f. As a result, the pressure increase in the main tank 204 can be mitigated and ink leakage to the outside can be prevented.

  Here, the buffer chamber 205f has a structure communicating with the hollow needle 205b in the vicinity of the bottom thereof. When the ink in the main tank 204 is consumed while the ink is stored in the buffer chamber 205f, the ink in the buffer chamber 205f is returned to the main tank 204 due to the negative pressure in the main tank 204, and the buffer chamber 205f The liquid level drops. When the liquid level in the buffer chamber 205f drops below the lower end of the hollow needle 205b, the lower end of the hollow needle 205b comes into contact with air, and the air is taken in from the lower end of the hollow needle 205b and flows into the main tank 204. If the internal force of the main tank 204 rises due to excessive inflow of air or environmental fluctuations, the ink flows out again to the buffer chamber 205f. Then, the liquid level of the ink in the buffer chamber 205f rises, and the lower end of the hollow needle 205b is immersed in the ink again.

  With such a structure, the ink in the main tank 204 is gradually consumed as recording progresses, while a certain amount of ink is stored in the buffer chamber 205f through the exchange of air and ink with the main tank 204. Will be stored.

  A circuit 205h for measuring the electrical resistance of ink is connected to the hollow needle 205a and the hollow needle 205b, and the presence or absence of ink in the main tank 204 can be detected. The circuit 205h is closed because a current flows through the circuit 205h through the ink in the main tank 204 when ink is present in the main tank 204. On the other hand, when no ink is present or the main tank 204 is not attached, no current flows, and the open circuit, that is, the resistance becomes infinite, so that these states are detected.

  The shut-off valve 210 inserted between the liquid passage 205d and the tube 206 has a diaphragm 210a made of an elastic material such as rubber, and by displacing the diaphragm 210a, a connection portion between the two liquid passages 205c and 205d is provided. Can be opened and closed. A cylindrical spring holder 210b that holds the pressing spring 210c inside is attached to the upper surface of the diaphragm 210a. By pressing the diaphragm 210a by the pressing spring 210c, the flow path between the liquid paths 205c and 205d is blocked.

  The spring holder 210b has a flange with which a lever 210d operated by a link 207e of a recovery unit 207 described later is engaged. Then, by operating the lever 210d, the spring holder 210b is raised against the spring force of the pressing spring 210c. As a result, the liquid paths 205c and 205d are in communication. Here, the shutoff valve 210 opens the flow path in a state where the recording head 201 discharges ink, that is, a recording state, so that ink is supplied to the recording head 201. On the other hand, the flow path is shut off during standby or pause when ink ejection is not performed, that is, in a non-recording state.

  The configuration of the ink supply unit 205 described above is provided for each main tank 204, that is, for each ink color, except for the lever 210d. The lever 210d is provided in common for all color main tanks, and the shutoff valves 210 for all colors can be opened and closed simultaneously.

  The recovery unit 207 of the present embodiment performs the above capping and recovery processing, and controls opening / closing of the shutoff valve 210, which will be described. The recovery unit 207 includes a suction cap 207a for capping the ejection surface of the recording head 201, and a link 207e for operating the lever 210d of the shutoff valve 210. As described above, the recovery process is a process for removing or removing a foreign matter that is a cause of ejection failure that causes clogging of the ejection port and recovering or maintaining the ejection performance in a good state. In the recovery process, the suction pump 207c is operated in a state where the discharge surface is capped by the suction cap 207a, and the suction force is applied to the discharge surface by the negative pressure generated in the cap 207a. Is forcedly discharged.

  The suction cap 207a is formed of an elastic member such as rubber at least at a peripheral portion in contact with the discharge surface, and is provided so as to be movable between a position where the discharge surface is sealed and a position where the discharge head is retracted. A tube in which a suction pump 207c such as a tube pump is inserted is connected to the suction cap 207a, and continuous suction can be performed by driving the suction pump 207c by a pump motor 207d.

  The cam 207b moves and sets the position of the suction cap 207a, and is rotated by a cam control motor 207g in synchronization with the cam 207f that operates the link 207e. The illustrated positions a, b, and c of the cam 207b correspond to the positions a, b, and c of the cam 207f, respectively. That is, when the cam 207b is in contact with the suction cap 207a at the positions a, b, and c, the cam 207f is in contact with the link 207e at the positions a, b, and c, respectively. More specifically, at the position a, the cam 207b separates the suction cap 207a from the ejection surface of the recording head 201, while the cam 207f displaces the link 207e in the right direction in the drawing to push up the lever 210d, 210 is opened (hereinafter referred to as phase A). At the position b, the cam 207b brings the suction cap 201g into close contact with the discharge surface, while the cam 207f displaces the link 207e in the left direction in the drawing to close the shutoff valve 210 (hereinafter referred to as phase B). At the position c, the cam 207b brings the suction cap 207a into close contact with the discharge surface, while the cam 207f displaces the link 207e in the right direction in the figure to open the shut-off valve 210 (hereinafter referred to as phase C).

  During the recording operation, the cams 207b and 207f are set to the phase A, so that ink can be ejected from the ejection port 201g and ink can be supplied from the main tank 204 to the recording head 201. During non-printing operations including standby and pause, the cams 207b and 207f are set to phase B to prevent the ejection port 201g from drying due to capping and the ink from the recording head 201 due to blockage of the ink supply path. To prevent the outflow.

  On the other hand, the phase C is set at the time of work involving the removal of the main tank, and this is a feature of this embodiment. Hereinafter, the work accompanied by removal of the main tank will be described.

  When the ink in the main tank 204 decreases and the circuit 205h for detecting electrical resistance detects an open circuit state, the user is notified of this, and the user performs replacement work of the main tank. Even if there is a remaining amount of ink, the user may remove the main tank for some reason. Then, there may be a case where the recording apparatus is transported to be moved to another place with the main tank removed.

  In any case, in the structure of the recording apparatus, while the ink in the main tank 204 is gradually consumed as the recording progresses, the buffer chamber is exchanged through the exchange of air and ink with the main tank 204. A certain amount of ink is stored in 205f.

  FIG. 3 is a diagram illustrating an example of a state in which the main tank 204 is removed. Ink remains in the main tank 204 as indicated by hatching, while ink flowing into the buffer chamber 205f remains as it is. When the recording apparatus is moved in this state, the ink remaining in the buffer chamber 205f leaks out of the apparatus through the ink supply needle 205b and the atmosphere communication hole 205g due to the posture and vibration during the movement of the recording apparatus. There is a fear.

  In the present embodiment, such inconvenience is prevented in advance by the following configuration.

  FIG. 4 is a block diagram illustrating a configuration example of a control circuit of the ink jet recording apparatus according to the present embodiment. In FIG. 4, reference numeral 101 denotes a programmable peripheral interface (hereinafter referred to as PPI). The PPI receives a command information (command) sent from the host computer 100 and a recording information signal including recording data and transfers it to the MPU 102. The host computer 100 also sends status information of the recording device to the host computer 100 as necessary. Send it out. In addition, input / output is performed with respect to the console 106 having a setting input unit in which the user performs various settings for the recording apparatus and a display unit for displaying messages to the user. Further, it receives a signal input from a sensor group 107 including a home position sensor for detecting that the carriage 202 or the recording head 201 is at the home position, a capping sensor, an electric resistance measurement circuit 205h, and the like.

  An MPU (microprocessing unit) 102 controls each unit in the recording apparatus according to a control program stored in the control ROM 105 and corresponding to a processing procedure described later with reference to FIG. Reference numeral 103 denotes a RAM that stores received signals or is used as a work area for the MPU 102 and temporarily stores various data. A font generation ROM 104 stores pattern information such as characters and records corresponding to the code information, and outputs various pattern information corresponding to the input code information. Reference numeral 121 denotes a print buffer for storing the recording data expanded in the RAM 103 or the like, and has a capacity for recording M rows. The control ROM 105 can store fixed data corresponding to a control program, control data, and the like. These units are controlled by the MPU 102 via the address bus 117 and the data bus 118.

  Reference numeral 3 denotes a main scanning motor for main-scanning the recording head 201 by moving the carriage 202, and reference numeral 5 denotes a sub-scanning motor for sub-scanning (conveying) the recording medium S by driving the conveyance roller 203. . Reference numerals 113, 114, 115, and 116 denote motor drivers for driving the cam control motor 207 g, the pump motor 207 d, the main scanning motor 3, and the sub scanning motor 5 in accordance with the control of the MPU 102.

  A sheet sensor 109 detects the presence or absence of the recording medium S, that is, whether or not the recording medium is supplied to a position where recording by the recording head is possible. Reference numeral 111 denotes a driver for driving an electrothermal transducer (heater) of the recording head 201 in accordance with a recording information signal. A power supply unit 124 supplies power to the above-described units, and includes an AC adapter and a battery as a drive power supply device.

  FIG. 5 is a flowchart illustrating a sequence performed when the recording apparatus is moved. This sequence is executed when the user desires to move (eg, transport) the recording apparatus with the main tank 204 removed, and is activated in response to an instruction from the host computer 100, for example. can do. Alternatively, it may be activated using a switch or the like provided in the recording apparatus.

  When this sequence is started from a normal state, first, a capping operation is started (S1). This capping operation is performed by driving the cam control motor 207g to rotate the cams 207b and 207f to the phase C. That is, at this time, the suction cap 207a is in close contact with the ejection surface, while the shutoff valve 210 allows the ink supply path to communicate.

  Next, the pump motor 207d is driven to perform a suction operation (S2). By thus driving the pump motor 207d in the capping state, the suction pressure is propagated to the main tank 209 through the flow path 201f, the sub tank 201b, the tube 206, the ink flow path 205c, and the like. Then, the ink in the buffer chamber 205f is sucked into the main tank 204. Further, the ink sucked from the flow path 201f is sequentially discharged from the pump 207c.

  FIG. 6 is a diagram illustrating a state in which ink is discharged from the buffer chamber 205f and the pump 201f described above.

  In the figure, cams 207b and 207f rotate to phase C, the ink in the buffer chamber 205f is sucked into the main tank 204, and the ink sucked from the flow path 201f is discharged from the pump 207c.

Here, the pump 207c is driven appropriately so as to obtain a predetermined ink suction amount (a fixed time in the case of a tube pump in which the driving time and the flow rate are proportional as in this example). In this example, the predetermined ink suction amount is the maximum volume for expanding the air in the main tank. That is, assuming that the main tank internal volume is V ₀ , the maximum air amount existing in the main tank is V ₀ . If the assumed maximum environmental temperature difference is Δt ° C., the volume ΔV _{max at} which the air in the tank expands to the _maximum is ΔV _max = V ₀ × Δt / 273. Therefore, ink corresponding to ΔV _max can flow into the buffer chamber 205f at the maximum. Therefore, if ink corresponding to the amount of ΔV _max is sucked, in any case, substantially all of the ink remaining in the buffer chamber 205f is sucked and guided into the main tank 204. Needless to say, the assumed environmental temperature difference Δt can be appropriately determined according to the area where the apparatus is installed and the usage environment.

In addition, when the apparatus stores the ink consumption amount in the main tank by using means such as counting dots of the recorded image, the suction amount according to the air amount increasing in the main tank according to the consumed ink amount By adjusting the, excess ink can be prevented from being discharged. That is, when the air amount inherent initially in the main tank and V _1, the total air quantity V in the main tank increases as the ink amount V ₂ consumed becomes at V _{1 +} V _2. Total air amount V in the main tank is typically less than the ink tank volume V _0. Since the volume ΔV in which the air in the tank expands is ΔV = (V ₁ + V ₂ ) × Δt / 273, it is sufficient to perform ink suction in an amount corresponding to this ΔV (<ΔV _max ). . In this case, substantially all of the ink in the buffer chamber 205f can be moved into the main tank 204 with a smaller pump drive amount, that is, an ink suction amount than in the case described above.

  Next, when the suction operation is completed, the removal of the main tank 204 is permitted (S3). That is, the main tank 204 can be removed with substantially no residual ink in the buffer chamber 205f.

  Further, in order to remove all ink from the ink supply system, the pump motor 207d is driven to perform a suction operation (S4). Here again, the pump motor 207d to the pump 207c are driven appropriately (for example, for a fixed time). The suction amount at this time is an amount corresponding to the total internal volume of the liquid path 201f, the sub tank 201b, the tube 206, and the ink flow path 205c. Thereby, all the ink of the ink supply system can be discharged.

  When the apparatus is transported in this state, all ink is discharged from the ink supply system including the buffer chamber 205f, so that ink leakage during transportation can be prevented. An amount of ink corresponding to the height of the other end of the hollow needle 205 from the bottom surface of the buffer chamber 205f can remain in the buffer chamber 205f, but the other end of the hollow needle 205b does not cause a problem. The position of should be determined.

  In the above embodiment, ink is forcibly discharged from the discharge port by applying a suction force to the discharge surface of the recording head, and the main tank is made to have a negative pressure so that ink is discharged from the buffer chamber to the main tank. The residual ink is removed from the buffer chamber by moving to the side. However, the present invention is not limited to the action of the suction force as long as the ink can be appropriately moved from the buffer chamber to the main tank side. For example, it is also possible to adopt a configuration in which ink is forcibly discharged from the discharge port by pressurizing the ink supply system, and ink is moved from the buffer chamber to the main tank side by making negative pressure in the main tank accordingly. It is.

  Further, the case where the present invention is applied to a so-called serial printer type ink jet recording apparatus has been described above. However, it goes without saying that the present invention can also be applied to a so-called line printer type in which the discharge ports are aligned over a range corresponding to the width of the recording medium.

  Further, the number of types of color tone (color and density) of the ink used is merely an example, and it goes without saying that an appropriate type of ink can be used.

1 is a perspective view showing a schematic configuration of an ink jet recording apparatus according to a first embodiment of the present invention. FIG. 2 is a diagram for explaining a detailed configuration of an ink supply system of the ink jet recording apparatus according to the first embodiment of the present invention. It is a figure when a main tank is removed from the inkjet recording device which concerns on the 1st Embodiment of this invention. FIG. 2 is a block diagram illustrating a configuration example of a control circuit of the ink jet recording apparatus according to the first embodiment of the present invention. It is a flowchart which shows the process at the time of the conveyance which concerns on the 1st Embodiment of this invention. FIG. 5 is a diagram for explaining a behavior of sucking ink from an air communication chamber of the ink jet recording apparatus according to the first embodiment of the present invention.

Explanation of symbols

201 recording head 201b sub tank 201g discharge port 202 carriage 203 transport roller 204 main tank 205 supply base 205a, 205b hollow needle 205f buffer chamber 206 tube 207 recovery unit 207a suction cap 207c suction pump 207d motor 210 shut-off valve

Claims (3)

A recording head that performs recording by discharging ink; an ink tank that accommodates ink supplied to the recording head and is detachable from the apparatus main body; and an ink that is connected to the ink tank and accommodated in the ink tank. A supply unit for supplying to the recording head, a storage unit for communicating with the ink tank and storing the ink flowing out from the ink tank when the air in the ink tank expands, and the storage unit In an ink jet recording apparatus comprising:
When removing the ink tank from the apparatus main body, the ink stored in the storage unit is moved to the ink tank by forcibly discharging the ink from the recording head and making the inside of the ink tank have a negative pressure. An ink jet recording apparatus comprising: a control means for controlling the ink jet recording apparatus.   A cap for capping the discharge port surface of the recording head; and a pump for communicating with the cap and setting a negative pressure in the cap. The control means caps the cap on the discharge port surface. 2. The ink jet recording apparatus according to claim 1, wherein the ink is forcibly discharged from the recording head by driving the pump in a state in which the ink is discharged.   The inkjet recording apparatus according to claim 2, wherein the control unit controls the drive amount of the pump based on an internal volume of the ink tank and an environmental temperature difference.

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