JP2010208152A - Inkjet recording apparatus and liquid filling method under initial state of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten time for filling a liquid into a region from a sub tank to a recording head under an initial state of a recording apparatus. <P>SOLUTION: In an inkjet recording apparatus, under a condition that a driving mechanism 30 closes a feeding valve 3 to stop an ink flow path, a suction pump 31 continuously forms a negative pressure in the recording head 1, and the suction pump 31 continuously forms the negative pressure in the recording head 1. In addition, in parallel to this, under a condition that the driving mechanism 30 opens an atmosphere communicating valve 9, ink is fed to the sub tank 4 from a main tank 5. In addition, the driving mechanism 30 opens the feeding valve 3 to feed the ink to the recording head 1 from the sub tank 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that performs recording by discharging a liquid onto a recording medium and a liquid filling method for an ink jet recording apparatus that fills the ink jet recording apparatus in an initial state.

  Among the recording systems such as printers, the ink jet recording system that forms characters and images on the recording medium by ejecting ink from the ejection ports is a low-noise non-impact recording system and can perform high-density and high-speed recording operations. Therefore, it has been widely adopted in recent years.

  Among ink jet recording apparatuses that perform recording by such an ink jet recording method, there is a serial scan type in which a recording operation is performed while moving a carriage on which a recording head is mounted in a direction crossing the recording medium conveyance direction. A serial scan type ink jet recording apparatus generally includes a recording head, a carriage on which the recording head is mounted, means for driving the carriage, means for transporting a recording medium, and control means for controlling these.

  In such an ink jet recording apparatus, recording is performed by supplying a liquid such as ink stored in a liquid storage section such as an ink tank to the recording head and discharging the liquid from the recording head. As a liquid supply method for supplying a liquid from such a liquid storage unit to a recording head, there is a head tank integrated method in which an ink tank as a liquid storage unit for storing a liquid is integrated with the recording head or detachably attached. In a head tank integrated type recording apparatus, an ink tank and a recording head are mounted on a carriage, and scanning is performed by moving the carriage in a direction intersecting the conveyance direction of the recording medium. And the recording operation is performed.

  However, recently, an ink jet recording apparatus has been used for applications such as plotters that record photographic images on large sheets such as A1 and A0 plates. When an ink jet recording apparatus is used for such an application, a large amount of ink is consumed per recording medium. Therefore, in such a case, the amount of ink consumed increases, the replacement frequency of the ink tank increases, and the handling of the recording apparatus becomes complicated. For this reason, in order to reduce the replacement frequency of the ink tank, an ink tank having a large capacity may be employed. However, when a head tank integrated type recording head is employed in an ink jet recording apparatus using an ink tank having a large capacity, the weight of the ink tank including the ink accommodated therein increases. For this reason, the power consumption required to move the recording head increases.

  For this reason, a so-called tube supply system is employed in which the ink tank and the recording head are arranged at different positions, connected between them by a tube, and ink is supplied from the ink tank to the recording head via the tube. Sometimes. If the ink tank is placed at a location different from the carriage, it is not necessary to move the ink tank even if a large capacity ink tank is used. Power consumption is reduced. In addition, when recording is performed by a tube supply type recording apparatus, a relatively large-capacity ink tank may be employed, so that continuous recording for a long time can be supported. As described above, when a large-capacity ink tank is required to output a large-format recording image in a serial scan type inkjet recording apparatus, a tube supply method capable of continuous recording for a long time is employed. There is.

  However, even in such a tube supply type recording apparatus, the amount of ink in the ink tank is limited, so it is required to replace the ink tank when the ink in the ink tank is used up. It is done. If the ink in the ink tank is used up while recording is being performed on one recording medium, it is required to interrupt the recording operation and replace the ink tank with respect to the ink tank. . In such a case, the ink ejected onto the recording medium during the ink tank replacement operation is in a dry state. For this reason, when the recording operation is started next, a difference in color (color unevenness) may occur between the recording portion formed immediately after resumption of the recording operation and the other portions. This tends to occur when inks of different hues are ejected in the same position on the recording medium. That is, when the recording operation is performed continuously without interruption, there is no significant time difference between the ink ejected first and the ink ejected later, so that the ink ejected earlier is not dried. In this state, the ink is discharged over the ink discharged later. Therefore, inks of different hues ejected in the same position are mixed with each other on the recording medium. On the other hand, when the recording operation is temporarily interrupted by replacing the ink tank, when the recording operation is resumed, the liquid ink is discharged on top of the already dried ink, and the two inks are not sufficiently mixed. As a result, in the portion recorded immediately after the ink tank replacement, the color of either one of the ink ejected first and the ink ejected later is emphasized. As a result, a difference in color occurs between the recording portion where the recording is continuously performed and the portion where the recording is resumed after being interrupted by the in-tank replacement.

  The color unevenness caused by the interruption at the time of replacement of the ink tank as described above has a particularly large influence on the image quality in a recording apparatus that can perform large-format recording at high speed using a long recording head. Effect. In addition, when the recorded image cannot be used as a product due to the occurrence of color unevenness, the ink and the recording medium are wasted and the running cost is increased. Therefore, in order to avoid a situation where the ink tank needs to be replaced during the recording operation to the recording medium, an ink jet recording apparatus using a sub tank separately from the main tank is proposed in Patent Document 1. . In the ink jet recording apparatus shown here, ink is supplied from a replaceable and large-capacity main tank to a sub-tank having a relatively small capacity, and ink stored in the sub-tank is supplied to the recording head.

  Therefore, even if the ink in the main tank is used up in the middle of recording on one recording medium, the ink remains in the sub tank, and the recording is continued by using the ink stored in the sub tank. can do. If the replacement of the main tank is completed while recording is being performed with the ink supplied from the sub tank, recording can be performed without interrupting the recording operation, and the quality of the recorded image can be maintained high. Can do.

JP 2001-113716 A

  Incidentally, in the recording apparatus disclosed in Patent Document 1, for example, in an initial state such as when not in use, the sub tank is not filled with ink, and the sub tank is empty. However, during recording, energy is applied to the liquid stored in the recording head, and the liquid is ejected from the recording head. For this reason, when the recording apparatus in the initial state is used for the first time, the recording head is required to be filled with ink. Further, when liquid is ejected from the recording head, a negative pressure is formed on the recording head, and the amount of liquid reduced by the liquid ejection is supplied from the sub tank to the recording head. At this time, in the tube type recording apparatus, in order to supply ink from the sub tank to the recording head in accordance with the negative pressure formed in the recording head, the inside of the supply tube between the recording head and the sub tank Are also required to be filled with ink. Therefore, when the recording apparatus performs recording, it is required that ink is filled from the sub tank to the recording head. Therefore, when an unused recording apparatus is used for the first time, it is necessary to fill the recording head, supply tube, and sub tank with ink before use. While the recording head, supply tube, and sub tank are filled with ink, recording cannot be performed, and the user is kept waiting during the ink filling process.

  In recent years, inkjet recording apparatuses corresponding to large-sized recording media have been put on the market one after another. As the recording apparatus supports the large-sized recording medium, the ink tank is also correspondingly increased in size. For example, a large main tank capable of accommodating 700 cc to 1000 cc of ink has been commercialized. When the main tank is increased in size, a large space is required to store the main tank, so that the replacement main tank may not be placed near the recording device. Therefore, the storage location of the main tank may be a location away from the recording device. In such a case, the time from when the ink in the main tank is used up during recording to when a new main tank is installed may increase. In order to cope with such a case, in the ink jet recording apparatus having the main tank and the sub tank, the capacity of the sub tank as a backup may be increased.

  However, when the amount of ink that can be stored in the sub tank is increased, the time required to fill the recording head, the sub tank, and the ink flow path between them when the recording apparatus in the initial state is used for the first time is used. become longer. It may take a considerable time of 30 minutes to 1 hour until the recording head of the recording apparatus, the sub tank, and the ink flow path between them are filled with ink and the recording apparatus becomes usable. The waiting time at this time may make the user feel annoying.

  Accordingly, in view of the above circumstances, the present invention provides a recording apparatus that performs recording by supplying liquid from the main tank to the sub tank and supplying liquid to the recording head. It aims at shortening the time which fills the liquid with.

  According to the ink jet recording apparatus of the present invention, the recording head that performs recording by discharging the liquid supplied from the first ink tank that is detachably mounted on the main body of the recording apparatus, and the gravity of the first ink tank. A second ink tank that is disposed in a lower direction and is capable of temporarily storing liquid supplied from the first ink tank to the recording head between the first ink tank and the recording head; In the ink jet recording apparatus, a negative pressure forming unit capable of forming a negative pressure inside the recording head, and a liquid flow path provided in the second ink tank and supplied to the recording head A supply valve capable of communicating and shutting off, an atmosphere communicating portion communicating the inside of the second ink tank and the atmosphere, and an atmosphere communicating capable of closing the atmosphere communicating portion. The negative pressure forming means includes the valve and a drive mechanism that drives the supply valve and the atmosphere communication valve, and the drive mechanism closes the supply valve and blocks the liquid flow path. In parallel with the negative pressure forming means continuing to form a negative pressure inside the recording head and the negative pressure forming means continuing to form a negative pressure inside the recording head, the drive mechanism opens the atmospheric communication valve and Liquid is supplied from the first ink tank to the second ink tank, and the drive mechanism opens the supply valve to supply liquid from the second ink tank to the recording head. .

  According to the ink jet recording apparatus of the present invention, in a recording apparatus that performs recording by supplying liquid from the main tank to the sub tank and supplying liquid to the recording head, the recording apparatus is in an initial state of the recording apparatus and in an area from the sub tank to the recording head. The time for filling the liquid can be shortened. As a result, the time from the initial state of the recording apparatus to the recordable state can be shortened, and the waiting time of the user can be reduced, so that the user is prevented from feeling bothersome. it can.

1 is a plan view of an ink jet recording apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view illustrating a state in which a supply valve is moved outward with respect to a configuration of an ink supply system that supplies ink to a recording head mounted on the ink jet recording apparatus of FIG. 1. FIG. 2 is a schematic cross-sectional view illustrating a state in which a supply valve has moved inward with respect to the configuration of an ink supply system that supplies ink to a recording head mounted on the ink jet recording apparatus of FIG. 1. FIG. 3 is a schematic cross-sectional view showing a state in which ink in a main tank is used up and air is supplied to a sub tank in the ink supply system of FIG. 2. FIG. 3 is a schematic cross-sectional view showing a state in which the ink in the main tank is used up and the ink in the sub tank is consumed and reduced in the ink supply system of FIG. 2. FIG. 3 is a schematic cross-sectional view showing a state in which the main tank is replaced and a new main tank filled with ink is installed in the ink supply system of FIG. 2. (A), (b), (c) is a schematic cross-sectional view showing an enlarged view of a sub-tank in a state where the supply valve moves and the atmospheric communication valve is opened and closed in the ink supply system of FIG. is there. 3 is a flowchart showing a control process when ink is filled by the ink supply system of FIG. 2. FIG. 2 is a block diagram illustrating a schematic configuration of a control system of the ink jet recording apparatus of FIG. 1. (A) is typical sectional drawing about the subtank which shows the state which the liquid level of the ink touched the solid pipe in a subtank, (b) is about the subtank which shows the state at the time of the ink filling operation | movement to a subtank completion | finish. It is typical sectional drawing of these. FIG. 2 is a schematic cross-sectional view illustrating a state in which a suction cap is attached to the recording head in the ink jet recording apparatus of FIG. 1 and a supply valve is closed and an air communication valve is closed. FIG. 2 is a schematic cross-sectional view showing a state in which a suction cap is attached to the recording head in the ink jet recording apparatus of FIG. 1 and a supply valve is opened and an air communication valve is closed. (A), (b), (c) is a schematic cross-sectional view showing an enlarged view of a sub-tank in a state where the supply valve is opened / closed and the air communication valve is opened / closed when ink is filled in the initial state. FIG. It is a flowchart which shows the process of the control at the time of filling with the ink in an initial state. FIG. 2 is a schematic cross-sectional view showing a state in which ink filling in an initial state is completed when an ink liquid level touches a solid tube in a sub tank in the ink jet recording apparatus of FIG. 1.

Embodiments for carrying out the present invention will be described below with reference to the accompanying drawings.
(First embodiment)
FIG. 1 is a schematic plan view for explaining a schematic configuration of an ink jet recording apparatus to which the present invention is applied. Note that the ink jet recording apparatus shown here is a so-called serial type ink jet recording apparatus that performs recording by moving a recording head capable of ejecting ink droplets in a direction intersecting the conveyance direction of the recording medium.

  In FIG. 1, a recording head 1 is an ink jet recording head capable of ejecting supplied ink from a plurality of ejection ports, and the recording head 1 is positioned on a carriage 102 and mounted in an exchangeable manner. The carriage 102 is provided with a connector holder (electrical connection part) for transmitting a drive signal and the like to the recording head 1 via a connector (not shown). The carriage 102 is supported by a guide shaft 103 installed in the apparatus main body so as to be reciprocally movable in the main scanning direction indicated by an arrow A. A timing belt 107 connected to the carriage 102 is bridged between a motor pulley 105 and a driven pulley 106 that are rotationally driven by the main scanning motor 104. The carriage 102 is moved in the main scanning direction by a driving mechanism constituted by the motor 104, pulleys 105 and 106, timing belt 107, and the like.

  A recording medium 108 such as a print sheet or a plastic thin plate is separated and fed from an auto sheet feeder (ASF) 114 one by one by rotating a pickup roller 113 by a paper feed motor 115 via a gear. Further, the recording medium 108 is conveyed in the sub-scanning direction indicated by the arrow B by the rotation of the conveying roller 109, and passes through a position (recording unit) facing the ejection port formation surface (ejection port surface) in the recording head 1. The conveyance roller 109 is rotated by a conveyance motor 116 via a gear. The determination of whether or not the recording medium 108 has been fed and the determination of the leading position of the leading edge of the recording medium at the time of feeding the paper has passed the position of the paper end sensor 112 provided at a fixed position of the apparatus body. Do it at the moment. Further, the paper end sensor 112 is also used to determine the rear end position of the recording medium 108 and to determine the current recording position from the rear end position of the recording medium 108. Note that the back surface of the recording medium 108 is supported by a platen (not shown) so as to form a flat recording surface in the recording unit.

  In the ink jet recording apparatus having the above-described configuration, the recording head 1 repeats the recording scan in which ink is discharged while scanning in the direction of arrow A together with the carriage 102, and the recording medium conveyance operation performed between each scan of the recording head, An image is formed on a recording medium.

  FIG. 2 is a schematic diagram of the overall configuration of the ink supply system for explaining the ink supply system of the inkjet recording apparatus 100 according to the first embodiment of the present invention. Here, for simplicity of explanation, only the path for one color of ink as a liquid is shown. FIG. 2 is a diagram showing a state in which ink is sufficiently contained in the main tank 5 and recording is performed using the ink in the main tank 5.

  First, the configuration of the ink supply system of this embodiment will be described. The ink supply system according to this embodiment includes a recording head 1, a main tank 5, a sub tank 4, and a buffer chamber 6. The recording head 1 of the present embodiment includes an element substrate provided with a recording element for ejecting ink, and an orifice plate bonded to the element substrate. The orifice plate has a plurality of ejection openings for ejecting ink droplets, and is bonded to the element substrate to form a foaming chamber as an energy action chamber that communicates with the ejection openings and an ink flow path that communicates with the chamber. Has been. Then, the ink is formed to be ejected from the ejection port by driving the recording element. In the present embodiment, an electrothermal conversion element that converts electrical energy into thermal energy is used as the recording element. The ink can be ejected from the ejection port by causing film boiling in the ink by the heat energy generated from the heater as the electrothermal conversion element and utilizing the pressure of the bubbles in the ink generated at that time. . As the recording head, various ejection methods such as a method of ejecting ink using a piezoelectric element can be used.

  The main tank (first ink tank) 5 is detachably mounted on the recording apparatus main body as a container that can store ink therein. In the present embodiment, the main tank 5 is formed so as to be able to accommodate a relatively large volume of ink. The ink stored in the main tank 5 is supplied to the sub tank 4 mounted on the recording apparatus main body, and the ink in the sub tank is supplied to the recording head 1 mounted on the carriage. The recording head 1 discharges the supplied ink from the discharge port and records an image. As the recording operation proceeds, ink is supplied from the main tank to the sub tank, and the ink in the main tank 5 decreases. When the ink in the may tank runs out, or when the amount becomes insufficient for recording on one recording medium, the main tank 5 is replaced with a new one filled with ink. .

  The sub tank (second ink tank) 4 is formed as a container that can store ink therein. The sub tank 4 is formed between the main tank 5 and the recording head 1 so that the liquid supplied from the main tank 5 to the recording head 1 can be temporarily stored. In the present embodiment, the sub tank 4 is disposed at a position below the main tank 5 in the direction of gravity. In order to prevent the recording operation from being interrupted while the main tank is being replaced while the main tank is empty, the sub-tank 4 has an amount of ink that can perform the recording operation during the replacement operation of the main tank 5. Contained. For this reason, as the amount of ink accommodated in the sub tank 4, it is sufficient to accommodate the amount of ink that exceeds the replacement work of the main tank 5. Therefore, the capacity of the sub tank 4 is larger than that of the main tank 5. It is formed relatively small. The main tank 5 and the sub tank 4 are communicated with each other by a first hollow tube 11 protruding from the upper surface of the liquid chamber 4 of the sub tank 4. In the present embodiment, the first hollow tube 11 is formed of a conductive member such as metal, and is formed so that ink can be circulated therein.

  Further, a supply tube 2 for connecting them is disposed between the recording head 1 and the sub tank 4. The supply tube 2 can circulate ink inside and supplies the ink inside the sub tank 4 to the recording head 1. The supply tube 2 is made of a flexible material, and can supply ink to the recording head 1 while scanning the recording head 1.

  Connected to the sub tank 4 is an air communication path 8 that communicates with the outside and allows air to flow between the inside and the outside of the sub tank 4. In the present embodiment, the atmosphere communication path 8 includes an introduction part 81, a space part 82, and a discharge part 83. The introduction portion 81 is formed to rise upward from the highest position 41 in the sub tank 4. The space portion 82 is formed by being connected to an outlet 81 b formed at the upper end of the introduction portion 81. The discharge part 83 is formed to fall below the bottom surface of the sub tank 4 from the space part 82. The atmosphere communication passage 8 is formed in an inverted U shape as a whole. The introduction port 81 a formed at the lower end portion of the introduction portion 81 is disposed at the same height position as the highest position in the sub tank 4. Further, the atmospheric communication passage 8 is provided with an atmospheric communication valve 9 slidably along the outer peripheral surface of the discharge portion 83, and the atmospheric communication valve 9 is moved to move the outlet of the atmospheric communication passage 8. A certain atmosphere communication port (atmosphere communication portion) 8a can be opened and closed. Therefore, when the atmosphere communication port 8a is in an open state, the air inside the sub tank 4 can be discharged from the atmosphere communication port 8a to the atmosphere via the introduction portion 81, the space portion 82, and the discharge portion 83. Thus, in the present embodiment, the atmosphere inside the sub tank 4 communicates with the atmosphere through the atmosphere communication port 8a. In addition, the atmospheric communication valve 9 enables the atmospheric communication port 8a to be closed.

  Further, a solid tube 13 formed of a conductive member such as a metal that comes into contact with the ink when the liquid level of the ink in the sub tank 4 is above a predetermined height is attached to the sub tank 4. The solid tube 13 and the hollow tube 11 are electrically connected by a wiring portion (not shown), and a closed circuit is formed when the solid tube 13 and the hollow tube 11 come into contact with the ink stored in the liquid sub tank. Then, an electrical signal indicating that the sub tank has been filled is output.

  In the present embodiment, the solid tube 13 is disposed on the inclined surface 42 formed on the upper surface of the sub tank 4 so that bubbles generated in the ink of the sub tank 4 are prevented from collecting around the solid tube 13. It is configured. According to this, even though the position of the liquid level has reached the contact position with the solid tube 13, the ink and the solid tube 13 are not in contact with each other due to the air bubbles accumulated around the solid tube 13. Thus, it is possible to avoid erroneous detection that the liquid surface position is not detected.

  Further, a supply valve 3 capable of changing the volume of the sub tank 4 is provided on a part of the wall surface forming the sub tank 4. In the present embodiment, the sub tank 4 is constituted by a liquid chamber portion 4a and a flow passage portion 4b communicating with the liquid chamber portion 4a, and the supply valve 3 is provided in the flow passage portion 4b. The supply valve 3 is formed by a diaphragm as a flexible rubber. As described above, the supply valve 3 of the present embodiment is provided in the sub tank 4 and enables the volume of the sub tank 4 to be changed. In the present embodiment, the supply valve 3 is formed as a part of the sub tank 4. FIG. 2 shows an initial state in which the supply valve 3 bulges outward from the wall surface of the flow path portion 4b, and the volume of the sub tank 4 is in an expanded state. On the other hand, FIG. 3 shows a state in which the central portion of the supply valve 3 is pressed to a position where it contacts the wall surface of the flow path portion 4b. In this embodiment, a communication port 4b1 that is opened and closed by the supply valve 3 is formed in the flow path portion 4b, and downstream of the communication port 4b1 (downstream in the direction of ink flow from the sub tank to the recording head). The lower end of the supply tube 2 is connected to the above. Therefore, when the supply valve 3 is pressed as shown in FIG. 3, the communication port 4b1 is closed by the supply valve 3, and the communication between the liquid chamber portion 4a and the recording head 1 is blocked. Yes. That is, the supply valve 3 is configured to also have a function as an on-off valve for communicating and blocking between the recording head and the liquid chamber portion 4a.

  Moreover, the flow path part 4b in which the supply valve 3 is provided is arrange | positioned in the lower part in the liquid chamber part 4a of the sub tank 4, and the communicating port with the liquid chamber part 4a is formed in the comparatively low position. . As a result, the ink is consumed and the air does not flow into the flow path portion 4b and the supply valve 3 until the amount of ink remaining in the sub tank 4 becomes a small amount.

  The buffer chamber 6 is formed so as to communicate with the main tank 5 as a container that can accommodate ink therein. An atmosphere communication path 7 that is open to the atmosphere is disposed inside the buffer chamber 6, and the space inside the buffer chamber 6 communicates with the atmosphere via the atmosphere communication path 7. The main tank 5 and the buffer chamber 6 are connected by a second hollow tube 12. In the present embodiment, the second hollow tube 12 is also formed of a conductive member such as metal, and is formed so that ink can be circulated therein. Since the main tank 5 and the buffer chamber 6 communicate with each other, even if the ink inside the main tank 5 expands due to the temperature rise and the pressure inside the main tank 5 increases, the main tank 5 The ink inside can flow into the buffer chamber 6. For this reason, it is suppressed that the pressure inside the main tank 5 rises excessively. The main tank 5 is formed so as to communicate with the atmosphere via the buffer chamber 6, and the buffer chamber 6 plays a role of balancing the pressure inside the main tank 5 with the atmospheric pressure.

  Here, a mechanism for performing the pressing and opening operation of the supply valve 3 and the opening / closing operation of the atmospheric communication valve in the present embodiment will be described. In the present embodiment, the volume expansion / reduction operation of the sub-tank 4 and the opening / closing operation of the atmospheric communication valve 9 by pressing and opening the supply valve 3 are performed by a drive mechanism 30 having a motor 14 as a single drive source. Is called. The drive mechanism 30 includes the motor 14 and a drive force transmission mechanism including a drive gear 14 a, an idle gear 15, and a planetary gear 16 fixed to the output shaft of the motor 14. The drive mechanism 30 includes a first gear 19 and a second gear 24 that are selectively rotated by a drive force transmission mechanism, a first cam 20 that rotates integrally with the first gear, and a second gear 24. It has the 2nd cam 25 which rotates integrally. Further, the drive mechanism 30 includes an atmospheric valve lever 21 that is operated by the first cam 20 and a supply valve lever 27 that is operated by the second cam 25.

  More specifically, the drive gear 14 a fixed to the output shaft of the motor 14 is arranged to mesh with the idle gear 15. Further, the idle gear 15 and the planetary gear 16 mesh with each other, and each gear transmits a driving force from the motor 14. The planetary gear 16 is connected to the idle gear 15 via the arm 17, and keeps a distance from the central axis of the idle gear 15, and either one of R 1 and R 2 depending on the rotation direction of the motor 14 shown in FIG. Can move in the direction. When the planetary gear 16 moves in the R1 direction, the planetary gear 16 can mesh with the gear 24, and when the planetary gear 16 moves in the R2 direction, it can mesh with the gear 19.

  The drive mechanism 30 further includes an atmospheric valve lever 21 that rotates about the fulcrum 22 as a central axis, and a supply valve lever 27 that rotates about the fulcrum 26 as a central axis. One end of the atmospheric valve lever 21 is connected to the atmospheric communication valve 9 for opening and closing the atmospheric communication port 8a described above, and is urged to a position where the atmospheric communication port 8a is opened by the urging force of the compression spring 23. ing. A pressing portion 20 a that protrudes outward is provided on a part of the outer periphery of the cam 20, and when the cam 20 rotates to a predetermined phase position, the pressing portion 20 a causes one end portion of the atmospheric valve lever 21 to move. It is pressed against the urging force of the compression spring 23. Further, a pressing portion 20 a that protrudes outward is provided on a part of the outer peripheral portion of the cam 20, and the pressing portion 20 a resists the compression spring 23 by rotating the cam 20 to a predetermined phase position. Thus, the supply valve lever 27 can be pressed. Sensors 42 and 43 for detecting the phase of the cam 20 and the cam 25 rotating together with the gear 24 and the gear 19 are arranged at positions close to the gear 24 and the gear 19, respectively. Among these, the supply valve sensor 42 detects the phase of the cam 25 that pushes the supply valve lever 27 that operates the supply valve 3 with the pressing portion 20a. The atmospheric valve sensor 43 detects the phase of the cam 20 that pushes the atmospheric valve lever 21 that operates the atmospheric communication valve 9 with the pressing portion 25a. The phases of the respective gears 19 and 24 can be accurately detected by the sensors 42 and 43, and the opening / closing operation of the atmospheric communication valve 9 and the expansion / reduction operation of the volume of the sub tank 4 by the movement of the supply valve 3 can be reliably performed. Has been. In this embodiment, the sensors 42 and 43 are optical photosensors having a light emitting element and a light receiving element. The sensors 42 and 43 detect the phases of the gears 19 and 24 by detecting the amount of light at the light receiving element. In the present embodiment, a flag is provided at a predetermined position of the gears 19 and 24. When the flag is positioned at a predetermined phase, light from the light emitting element is blocked and the amount of light received by the light receiving element is changed to change the gear. The phases 19 and 24 are detected. The form of the sensors 42 and 43 is not limited to this, and other forms may be used. For example, a magnetic sensor that detects a change in a magnetic field that is generated when a gear passes a nearby position may be used.

  Further, as shown in FIG. 11, the recording apparatus main body has a discharge port surface of the recording head 1 when a carriage 102 that scans in a direction crossing the conveyance direction of the recording medium is disposed at a predetermined position in the main scanning direction. A suction cap 34 is formed so as to cover the surface. In the present embodiment, as shown in FIG. 1, the suction cap 34 is disposed so as to cover the discharge port surface of the recording head 1 when the carriage 102 is positioned at a home position formed at one end portion in the main scanning direction. Has been. Further, a suction cap passage 32 extends from the suction cap 34 to the opposite side of the recording head 1, and a suction pump can be formed in the suction cap passage 32 so that a negative pressure can be formed in the suction cap 34. 31 is arranged. In the present embodiment, a tube pump is used as the suction pump 31. The limit value of the negative pressure in the tube pump is determined by the restoring force of the tube used in the tube pump, and in this embodiment, in this region until the pressure in the recording head 1 becomes 0.8 atm by the suction pump 31. The negative pressure increases.

  FIG. 9 is a block diagram illustrating a schematic configuration of a control system of the ink jet recording apparatus according to the present embodiment. In FIG. 9, the operation of each unit of the ink jet recording apparatus is controlled by the CPU 120 based on a control program stored in the ROM 121 and various data stored in the RAM 122. That is, the CPU 120 includes a head driving circuit 123 that drives an electrothermal conversion element provided in the recording head 1, a main scanning motor driving circuit 124 that drives the main scanning motor 104, and a conveyance motor driving circuit 125 that drives the conveyance motor 116. Etc. are connected. Further, a motor 4 that is a drive source for opening and closing the atmospheric valve 9 and moving the supply valve 3 is connected to the CPU 120. A suction pump drive circuit 130 that drives the suction pump 31 is connected to the CPU 120. Further, the CPU 120 is connected to a display unit 52 that displays an operation state of the ink jet recording apparatus, an ASF 114 that supplies a recording medium, and the like. The CPU 120 is connected to the atmospheric valve sensor 43, the supply valve sensor 42, the paper end sensor 112, and the like. The CPU 120 is connected to a liquid detection circuit 50 that outputs a signal indicating whether or not the amount of ink stored in the main tank 5 and the sub tank 4 has reached a predetermined amount or less. The liquid detection circuit 50 applies a predetermined voltage between the first hollow tube 11 and the second hollow tube 12 and between the first hollow tube 11 and the solid tube 13. Apply. Then, it is detected whether a current flows between the first hollow tube 11 and the second hollow tube 12 or between the first hollow tube 11 and the solid tube 13, and the current flows. If it is detected, a detection signal is output to the CPU 120. The liquid detection circuit 50, the hollow tubes 11, 12 and the solid tube 13 constitute liquid detection means for detecting whether or not ink is present in the main tank and the sub tank.

  In the above control system, the CPU 120 performs a recording operation, an ink filling operation to the sub tank, and the like according to a control program stored in the ROM 121 in accordance with signals output from the liquid detection circuit 50 and the sensors of the respective units. Various operations are controlled. For example, in the ink filling operation to the sub tank executed after the replacement of the main tank 5, signals representing the phases of the cams 20 and 25 detected by the supply valve sensor 42 and the atmospheric valve sensor 43 are input to the CPU 120. . The CPU 120 controls the rotation direction and the rotation amount of the motor 14 based on those phases and the signal from the liquid detection circuit 50.

  When the recording head 1 in the ink jet recording apparatus 100 configured as described above ejects ink and performs a recording operation, and ink is consumed along with this, negative pressure is generated in the recording head 1. The negative pressure in the recording head 1 is transmitted to the sub tank 4 through the tube 2, and the ink in the sub tank 4 is supplied to the recording head 1. At this time, since the atmospheric communication valve 9 is closed, the negative pressure propagates into the sub tank 4 without escaping to the outside. Since the main tank 5 and the sub tank 4 communicate with each other through the first hollow tube 11 as described above, if a negative pressure is formed in the sub tank 4, the negative pressure causes the main tank 5 to Ink is supplied to the sub tank 4. In the present embodiment, since the main tank 5 and the buffer chamber 6 communicate with each other via the second hollow tube 12 as described above, the interior of the buffer chamber 6 communicated with the outside through the atmosphere communication passage 7. Air can flow into the main tank 5. Therefore, even if the ink in the main tank 5 is reduced as a result of the recording as described above, the pressure in the main tank 5 is balanced with the atmosphere and the pressure in the main tank 5 is prevented from excessively decreasing. It is done. In this way, ink is discharged from the recording head 1 and the amount of ink in the sub-tank 4 decreases, so that when a negative pressure of a predetermined value or more is generated in the sub-tank 4, the ink is supplied from the main tank 5 to the sub-tank 4. The

  The liquid level of the ink in the sub tank 4 is adjusted so as to be located in a certain region. In the present embodiment, in a state where the ink is stored in the main tank 5, adjustment is made so that the liquid level of the ink is positioned between the lower end portion of the solid tube 13 and the upper surface of the sub tank 4 in the sub tank 4. Has been.

  When the recording operation is continued by the recording apparatus of this embodiment and the ink in the main tank 5 is continuously consumed, the ink in the main tank 5 continues to decrease, and the ink in the main tank 5 is used up one day. When the ink in the main tank 5 is used up and the ink is used up, air is supplied from the main tank 5 to the sub tank 4. Accordingly, when ink is continuously ejected from the recording head 1 after the main tank 5 is emptied, air is supplied into the supply path 10 of the sub tank 4 as shown in FIG. As shown in FIG. 4, the air flows into the supply path 10 in the sub tank 4 through the first hollow pipe 11 that connects the main tank 5 and the sub tank 4. In this way, when the ink in the main tank 5 is used up and emptied after the recording head 1 is consumed, the air in the main tank 5 and the ink in the sub tank 4 are replaced and the sub tank 4 is filled with air. Air will flow in.

  In the present embodiment, a predetermined voltage is applied between the hollow tube 11 and the solid tube 13 to detect the remaining amount of ink in the sub tank 4, and the hollow tube 11 and the solid tube 13 are energized. Whether or not ink is present in the supply path 10 is determined based on whether or not the ink is present. At this time, when ink is present in the supply path 10, the space between the hollow tubes 11 and 13 is energized, and when there is a region where no ink is present, the current is not energized. By this energization, it is determined whether ink is stored in the supply path 10, thereby confirming the presence or absence of ink in the main tank 5. For example, when the electrical connection between the hollow tube 11 and the solid tube 13 is cut, it is detected that the ink in the sub tank 4 has started to be consumed. At this time, it is considered that the main tank 5 is empty without ink and the air in the main tank is sucked into the supply path 10 of the sub tank 4. In order to increase the accuracy in detecting the presence or absence of ink in the main tank 5, a cylindrical portion having a relatively small inner diameter extending in the vertical direction is formed. In the present embodiment, the inner diameter of the hollow tube 11 is φ1.6 mm, and the inner diameter of the supply path 10 is φ2 mm to φ3 mm. When the main tank 5 is almost emptied, air is introduced into the hollow tube 11 and the flow path 10, and the electrical connection is cut off, so that it is possible to detect ink shortage. At this time, since the wall surface forming the supply path 10 is formed in a cylindrical shape having a relatively small inner diameter, the displacement of the liquid level is caused when the air level is lowered by supplying air into the sub tank 4. It becomes relatively large. As described above, since the ink liquid level is greatly displaced when air is supplied into the sub tank 4, the hollow tube 11 and the solid tube 13 can be used even if the amount of air flowing from the main tank to the sub tank is small. Can be reliably cut off. As a result, it is possible to reliably detect that the ink in the main tank 5 has run out by the displacement of the ink liquid level. As described above, the presence or absence of ink in the sub tank 4 is detected at a position close to the ink supply port from the main tank 5 and the supply of ink from the main tank 5 is stopped. A sensor (liquid presence / absence detection sensor) is attached. In this embodiment, in particular, the hollow tube 11 has a function as an ink supply port from the main tank 5 and an ink presence / absence detection sensor, and determines the position of the ink supply port from the main tank 5 and the presence / absence of ink. The detection positions are substantially the same.

  When the main tank 5 is replaced, a certain amount of ink is held in the sub tank 4. After ink out of the main tank 5 is detected by detecting the presence or absence of ink in the supply path 10 in the sub tank 4, the ink consumption by the recording head 1 is calculated by the number of ink ejections, and based on the ink consumption. The remaining amount of ink in the sub tank 4 is calculated. Thereafter, if the main tank 5 is not replaced, the recording is continued, and the recording is interrupted when the sub tank 4 becomes empty. At this time, the recording operation is unavoidably interrupted, and a notification operation that prompts replacement work of the main tank 5 is performed.

  When the ink out of the main tank 5 is detected, the recording device indicates this on the display or the display unit of the recording device and notifies the user of the ink out. The user may replace the main tank 5 in response to this notification. As described above, when the recording device detects that the ink in the main tank 5 is out of ink, the main tank is exchanged accordingly.

  When the main tank 5 is replaced, the main tank 5 is pulled upward, and the main tank 5 is pulled out from the first hollow tube 11 and the second hollow tube 12. As a result, the empty main tank 5 is removed from the sub tank 4 and the buffer chamber 6. Then, a new main tank 5 containing ink is punctured so that the first hollow tube 11 and the second hollow tube 12 pass through the wall surface of the main tank 5, and the sub tank 4 and the buffer chamber 6 are connected to the main tank 5. Connect to tank 5.

  In the present embodiment, a predetermined voltage is applied between the first hollow tube 11 and the second hollow tube 12, and the first hollow tube 11 and the second hollow tube 12 are It can be confirmed whether or not the main tank 5 filled with ink is attached depending on whether or not the gap is energized. Thus, in this embodiment, the main tank mounting detection sensor (first ink tank mounting detection sensor) for detecting that the main tank 5 filled with ink is mounted is attached.

  Here, when the recording operation is interrupted due to the replacement work of the main tank 5, as described above, between the area recorded immediately after the interruption of the recording operation and the area where the recording operation was continuously performed. A difference in color occurs in the image quality, resulting in a decrease in image quality. Therefore, in order to suppress the color unevenness generated in the image obtained by recording in this way, it is required that the recording operation be performed even while the main tank 5 is being replaced. For this reason, in the recording apparatus of the present embodiment, the sub tank 4 is attached separately from the main tank 5, and even when the main tank 5 is removed, the ink in the sub tank 4 is used and the recording operation is continued. Thereby, it is possible to suppress a decrease in image quality due to the interruption of the recording operation when the main tank 5 is replaced.

  FIG. 5 is an explanatory diagram showing a state in which the ink in the sub tank 4 is consumed and reduced by further performing the recording operation from the state shown in FIG. In a state where the recording operation is being performed, the atmospheric communication valve 9 is closed and the supply valve 3 is in an initial state in which it has expanded outward, so that the volume in the sub tank 4 is maintained in an expanded state.

  Although the main tank 5 is disposed at a position higher than the sub tank 4, even if the main tank 5 containing ink is mounted, the ink is not immediately supplied into the sub tank 4. Normally, the main tank 5 is exchanged in an empty state. Therefore, when the main tank 5 is exchanged, the supply passage 10 in the sub tank 4 is in an empty state as shown in FIG. Air is sucked from the tank 5 and air flows into the sub tank 4. Therefore, normally, when the main tank 5 is replaced, air exists in the supply path 10 of the sub tank 4.

  Further, when the main tank 5 is replaced, the air communication valve 9 is closed. Air is contained in the upper part of the ink in the sub tank 4. As a result, even if the main tank 5 containing the ink and the sub-tank 4 communicate with each other by exchanging the main tank 5, the air is not released to the outside of the sub-tank 4. Does not flow. For this reason, even if the main tank 5 is replaced, ink is not supplied from the main tank 5 unless a negative pressure is generated in the sub tank 4.

  Therefore, in order to supply ink to the sub tank 4, a negative pressure is generated in the sub tank 4, and the air in the sub tank 4 is replaced with the newly exchanged ink in the main tank 5. It is required to be filled with ink. Here, the outline of the ink filling operation to the sub tank will be described with reference to FIGS. 7A to 7C are explanatory views showing the operation of each part around the sub tank when the sub tank is filled with ink, and FIG. 8 is a diagram showing the operation during the ink filling operation to the sub tank shown in FIG. It is a flowchart which shows a control process.

  FIG. 7A shows a state in which the main tank 5 has been replaced and the ink in the sub tank has become slightly in a state. FIG. The states where air is sent out to the outside of the sub tank 4 are shown. FIG. 7C shows a state where ink is supplied from the main tank 5 into the sub tank 4 by moving the supply valve 3 outward.

  As shown in FIG. 7A, immediately after the main tank 5 is replaced, the supply valve 3 is expanded outward, and the volume of the sub tank 4 is expanded. At this time, the air communication valve 9 is closed. Next, as shown in FIG. 7B, after the atmospheric communication valve 9 is changed from the closed state to the opened state (S201), the supply valve 3 is positioned inward to reduce the volume of the sub tank 4 (S202). . In the present embodiment, the supply valve 3 is configured such that the sub tank 4 can change its volume by about 0.5 cc by movement. As described above, in the liquid filling method for the sub tank according to the present embodiment, the volume change member reducing step (reducing the volume of the supply valve portion that can change the volume of the sub tank 4 after opening the atmosphere communication port 8a ( S202). Further, the liquid filling method for the sub-tank of the present embodiment includes a volume changing member expansion step (S201) for expanding the volume of the supply valve 3 after closing the atmosphere communication port 8a.

By moving the supply valve 3 inward, ink of a volume of about 0.5 cc is pushed out from the supply valve 3 to the main tank side in the sub tank 4. At this time, the flow path resistance ΔP _H (the flow path resistance of the supply tube 2) from the supply valve 3 to the recording head 1 is overwhelming compared to the flow path resistance ΔP _S from the supply valve 3 to the sub tank 4 (main tank 5). Therefore, almost no ink is pushed out to the recording head 1 side.

  Next, as shown in FIG. 7 (c), after the atmospheric communication valve 9 is changed from the open state to the closed state (S203), the initial state of bulging outward from the state in which the supply valve 3 is pressed inward. (S204). The movement of the supply valve 3 increases the volume of the sub tank 4. As a result, a negative pressure is generated in the sub tank 4, and about 0.5 cc of ink flows into the supply valve 3, and ink is supplied from the main tank 5 to the sub tank. At this time, since the atmosphere communication valve 9 is closed, air hardly enters the sub tank 4 from the outside of the recording apparatus via the atmosphere communication path 8. Although the main tank 5 has a negative pressure, air is introduced into the main tank 5 from the buffer chamber 6 via the atmosphere communication path 7, so the negative pressure in the main tank 5 is eliminated. As a result, a certain amount of ink is introduced from the main tank 5 to the sub tank 4.

  Next, the operation of each part of the drive mechanism 30 when supplying ink from the main tank 5 to the inside of the sub tank 4 after replacement of the main tank 5 in the ink supply system of the present embodiment will be described.

  As described above, in order to supply ink from the main tank 5 to the sub tank 4 while removing air from the sub tank 4 after the replacement of the main tank 5, the movement operation of the supply valve 3 (movement of the diaphragm) and the air communication valve Repeat 9 open / close operation. As the states of the supply valve 3 and the atmospheric communication valve 9 in the recording apparatus at this time, two states can be considered. First, as one state, as shown in FIG. 2, the supply valve 3 is expanded outward from the sub tank 4 and the volume of the portion surrounded by the supply valve 3 is expanded (hereinafter this state is referred to as “supply valve”). And the atmospheric communication valve 9 is closed. Further, as the other state, as shown in FIG. 3, the supply valve 3 is pressed and the internal volume of the portion surrounded by the supply valve is reduced (hereinafter, this state is referred to as a reduced state of the supply valve). And the atmosphere communication valve 9 is open.

  As shown in FIG. 2, the supply valve 3 is in an expanded state and the atmosphere communication valve 9 is closed, and the supply valve 3 is in a contracted state and the atmosphere communication valve 9 is closed as shown in FIG. The operation of each part in the case will be described.

  In the state shown in FIG. 2, the pressing portion 20a of the first cam 20 presses the end portion (right end portion in the figure) of the atmospheric valve lever 21 against the urging force of the compression spring 23, thereby the atmospheric valve lever. The atmospheric communication valve 9 provided at the other end portion (the left end portion in the figure) 21 is closed at the atmospheric communication port 8a. The pressing portion 25a of the second cam 25 is in a state of being separated from the supply valve lever 27, and the supply valve lever 27 is in contact with the circular outer peripheral surface of the cam 25 by the biasing force of the spring. At this time, one end portion (left end portion in the figure) of the supply valve lever 27 is in a state where the supply valve 3 is not pressed (open state), and the supply valve 3 is maintained in an expanded state.

  Here, first, the motor 14 is driven, and the drive gear 14a is rotated in the S2 direction. The rotational force of the drive gear 14a is transmitted to the planetary gear 16 through the idle gear 15, and the planetary gear 16 rotates about its rotation center axis. The idle gear 15 rotates at a fixed position around a shaft (not shown) held at the fixed position. The rotation of the planetary gear 16 causes the first cam 20 to rotate together with the gear 19 engaged therewith, and the pressing portion 20a is separated from the end portion (right end portion) of the atmospheric valve lever 21. As a result, the atmospheric valve lever 21 rotates counterclockwise in FIG. 2 around the fulcrum 22 by the elastic force of the compression spring 23, and moves the atmospheric communication valve 9 from a position where the atmospheric communication port 8a is closed. Thereby, the atmosphere communication port 8a is opened to the atmosphere.

  Next, when the drive gear 14a is rotated in the S2 direction by the motor 14, the idle gear 15 meshed with the drive gear is rotated. Due to the rotation of the idle gear 15, the planetary gear 16 meshing with the idle gear 15 moves in the R1 direction and meshes with the gear 24 as shown in FIG. By continuing to drive the motor 14 after that, the gear 16 rotates around its rotation center, the pressing portion 25a moves to a position facing the supply valve lever 27, and the end of the supply valve lever 27 (Right end in the figure) is pressed against the compression spring 28. Thereby, the other end part (the left end part in the figure) of the supply valve lever 27 presses the supply valve 3, and the supply valve 3 is reduced (see FIG. 3). By reducing the supply valve 3 in this way, the ink in the supply valve 3 is sent to the liquid chamber 4a side of the sub tank 4 and the ink level in the liquid chamber 4 rises. At this time, since the atmosphere communication port 8a is opened by the atmosphere communication valve 9, the air accumulated in the upper part of the sub tank 4 as the ink level in the liquid chamber 4 rises from the atmosphere communication port 8a. Released into the atmosphere.

  As described above, the positional relationship of the supply valve 3 and the atmospheric communication valve 9 can be changed from the state of FIG. 2 to the state of FIG.

  Next, as shown in FIG. 3, the supply valve 3 is in the contracted state and the atmosphere communication valve 9 is opened, and then the supply valve 3 is in the expanded state as shown in FIG. The operation of each part when 9 is closed will be described.

  When the motor 14 is driven to rotate the drive gear 14a in the S1 direction from the diaphragm contraction state shown in FIG. 3, the planetary gear 16 moves in the R2 direction as the idle gear 15 rotates, Mesh. Thereafter, by continuously driving the motor 14, the planetary gear 16 rotates through the idle gear 15, and the gear 19 and the cam 20 rotate in conjunction with the rotation. By the rotation of the cam 20, the pressing portion 20 a presses the end of the atmospheric valve lever 21 against the compression spring 23 to rotate the atmospheric valve lever 21 around the fulcrum. The atmospheric communication valve 9 moves with the movement of the atmospheric valve lever 21 and closes the atmospheric communication port 8a that has been open until then. At this time, the rotation of the motor 14 is temporarily stopped. Further, the supply valve 3 maintains the contracted state shown in FIG.

  After the atmospheric communication port 8a is closed by the atmospheric communication valve 9 as described above, the motor 14 is driven and the drive gear 14a is rotated in the S1 direction. As the idle gear 15 rotates in conjunction with the rotation of the drive gear 14a, the planetary gear 16 moves in the R1 direction and meshes with the gear 24. Even after the planetary gear 16 and the gear 24 are engaged, the driving gear 14 continues to rotate by the driving force of the motor 14, whereby the planetary gear 16 rotates about its rotation center and rotates the gear 24. As a result, the pressing portion 25a of the cam 25 is separated from the supply valve lever 27, and the supply valve lever 27 rotates about the fulcrum 26 in the clockwise direction in FIG. As a result, the supply valve lever 27 releases the pressing force on the supply valve 3, and the supply valve 3 returns to the expanded state shown in FIG. 2 by its own restoring force. At this time, since the atmosphere communication port 8a is closed, when the supply valve 3 returns to the expanded state, a negative pressure is generated in the sub tank 4, and the ink in the main tank 5 passes through the hollow tube 11 to enter the sub tank. Flow into.

  As described above, by repeatedly reducing and expanding the diaphragm and opening and closing the atmosphere communication port 8a, the ink in the main tank 5 is supplied to the sub tank 4 by a fixed amount (0.5 cc in this embodiment). Go. In the above operation, when the gears 19 and 24 are rotated, the phases of the cams 20 and 25 are accurately detected by the supply valve sensor 42 and the atmospheric valve sensor 43 attached to the gears 19 and 24, respectively. Has been. Therefore, it is possible to accurately grasp the open / close state of the atmosphere communication valve 9 and whether the supply valve 3 is located relatively outside or inside the sub tank 4.

  FIG. 10A shows the recording apparatus in a state where the liquid level of the ink is in contact with the solid tube 13 in the sub tank 4, and FIG. 10B shows the state when the ink filling operation to the sub tank 4 is completed. A recording device is shown.

  As described above, the method for detecting the presence or absence of ink in the main tank 5 is determined based on whether or not the space between the solid tube 13 in the sub tank 4 and the hollow tube 11 in the main tank 5 is filled with ink. To do. At this time, if the space between the solid tube 13 and the hollow tube 11 is filled with ink, it is energized when electricity flows between them, and an electric signal from one is detected by the other. It is possible to detect that the ink is filled. Also in the ink filling operation in the sub tank 4, it is determined by whether or not electricity is conducted in the space between the solid tube 13 and the hollow tube 11. FIG. 10A shows a state immediately after the space is filled with ink and electricity is conducted (S205). In the present embodiment, the top surface of the sub tank 4 is inclined, the discharge port to the atmosphere is positioned above the inclination, and the ink introduction port from the main tank 5 to the sub tank 4 is positioned below the inclined surface. A solid tube 13 for detecting the presence or absence of ink is positioned in the middle of the inclined surface. As a result, the air accumulated in the sub tank 4 is smoothly removed through the atmosphere communication path 8. By forming the sub-tank 4 in this way, it is possible to prevent erroneous detection in detecting the presence or absence of ink so that the air in the sub-tank 4 does not escape and the presence of ink is not detected despite being filled with ink. is doing. When the state shown in FIG. 10A is reached, the certain amount of sub-tank 4 has been filled with ink. In the present embodiment, thereafter, the control of the volume change member reduction step and the volume change member enlargement step is performed once to make one set, and this set is made 10 times to finish (S206). The number of times the volume change member reduction step and the volume change member enlargement step are repeated is not limited to 10 times, and may be another number. It may be repeated until the presence of ink is detected by detecting the presence or absence of ink between the solid tube 13 and the hollow tube 11. Further, the amount of ink in the sub tank may be adjusted according to the purpose of recording.

  In the present embodiment, the supply valve 3 and the atmospheric communication valve 9 are opened / closed a predetermined number of times after the remaining amount is detected, and in this embodiment, the opening / closing operation is particularly performed 10 times. However, when it is detected that the ink is sufficiently stored in the supply path 10 of the sub-tank 4 by detecting the remaining amount, these opening / closing operations may be stopped.

  If not only the form of the embodiment of the present invention but also the above-described flow path resistance magnitude relationship is maintained, substantially the same effect can be obtained by controlling other behaviors (such as the opening / closing speed of the supply valve).

  Thus, in the present embodiment, the step of moving the supply valve 3 inward after opening the atmosphere communication port 8a, and the step of moving the supply valve 3 outward after closing the atmosphere communication port 8a, Is repeated to fill the sub tank with ink. Therefore, when ink is supplied from the main tank 5 into the sub tank 4, the structure for forming the negative pressure in the sub tank 4 can be simplified. As a result, the structure of the recording apparatus can be simplified, and the manufacturing cost of the recording apparatus can be kept low.

  Further, according to the configuration of the recording apparatus of the present embodiment, a means for forming a negative pressure for supplying ink into the sub tank 4 and a drive mechanism for removing air from the sub tank 4 are driven. The drive source can be shared. In general, since a drive source for forming a negative pressure in the sub tank 4 and a drive source for removing air from the sub tank 4 are formed separately, a drive source such as a motor is required separately, thereby recording. The manufacturing cost of the device was high. On the other hand, in this embodiment, the volume change of the portion surrounded by the supply valve 3 and the opening / closing operation of the atmospheric communication valve 9 are selectively operated. Thereby, the drive source for forming a negative pressure in the sub tank 4 and the drive source for removing air from the sub tank 4 are driven by a single drive source. Therefore, the structure of the recording apparatus is further simplified, and the manufacturing cost of the recording apparatus can be further reduced.

  Here, in the liquid filling method for the sub tank of the present embodiment, the volume change for reducing the volume of the portion surrounded by the supply valve 3 that can change the volume of the sub tank 4 after opening the atmosphere communication port 8a. A member reduction step (S202) is included. And the liquid filling method to the sub-tank of this embodiment has the volume change member expansion step (S201) which expands the volume of the part enclosed by the supply valve 3 after obstruct | occluding the atmosphere communication port 8a. It was. At this time, in order to quickly supply the ink to the sub tank 4, in the volume changing member reduction step, the air communication port 8 a is opened and the volume of the portion surrounded by the supply valve 3 is reduced. A shorter time is preferred. In the present embodiment, the time from when the atmosphere communication port 8a is opened until the volume of the portion surrounded by the supply valve 3 is reduced is set to be within 5 seconds. Similarly, in the volume changing member enlargement step in which the volume of the portion surrounded by the supply valve 3 is increased after the atmospheric communication port 8a is closed, the atmospheric communication port 8a is closed and then surrounded by the supply valve 3. It is preferable that the time until the volume of the portion is increased is shorter. In this embodiment, the time from when the atmospheric communication port 8a is closed to when the volume of the portion surrounded by the supply valve 3 is expanded is within 5 seconds.

  Furthermore, it is preferable that the time between the volume change member reduction step and the volume change member enlargement step is short. In this embodiment, in order to supply ink to the sub-tank 4, when each step of the volume change member reduction step and the volume change member enlargement step is repeated, the time of each step is within 5 seconds. .

  Next, a method for filling ink into the sub tank 4 when the recording apparatus of the present embodiment is first used will be described. When the recording apparatus is used for the first time, the sub tank 4, the supply tube 2 and the recording head 1 are not filled with ink.

  When the sub tank 4 is filled with ink when the recording apparatus is first used, the discharge port surface of the recording head 1 is first covered by the suction cap 34, and the space between the suction cap 34 and the recording head 1 is first covered. The discharge port surface of the recording head 1 is sealed while maintaining high airtightness. Then, the supply valve 3 and the air communication valve 9 are closed while the discharge port surface of the recording head 1 is sealed. Then, in this state, the suction pump 31 is driven, a suction force is applied to the discharge port surface of the recording head 1, and ink in the recording head 1 and the supply tube 2 is sucked.

  At this time, since the flow path portion 4b in the sub tank 4 is closed by the supply valve 3, the communication between the liquid chamber portion 4a in the sub tank 4 and the recording head 1 is blocked. Accordingly, the suction force continues to be applied to the recording head 1, the supply tube 2, and the sub tank 4 in the state where the area closer to the recording head than the communication port 4b1 of the supply valve 3 is closed. The negative pressure that is increased. Finally, the internal negative pressure is increased to the maximum negative pressure in the area closer to the recording head than the communication port 4 b 1 of the supply valve 3 in the recording head 1, the supply tube 2, and the sub tank 4. When the negative pressure is increased to the maximum negative pressure value in this region, the supply valve 3 is opened there (202 in FIG. 6). At this time, since the air communication valve 9 is closed, when a negative pressure reaches the sub tank 4 and the main tank 5, a certain amount of ink from the main tank 5 to the supply path 10 is introduced.

  Next, using FIG. 11 and FIG. 12, the first step for filling the first hollow tube 11 in the flow path between the main tank 5 and the sub tank 4 and the supply path 10 in the sub tank 4 with ink. explain. A control flow in the recording apparatus at this time will be described with reference to FIG.

  First, the nozzle face of the recording head 1 is sealed with the suction cap 34, and the inside of the recording head 1 is sucked with the suction pump 31 while the supply valve 3 and the atmosphere communication valve 9 are closed (S301).

  The operation of each part of the drive mechanism 30 at this time will be described. Here, as shown in FIG. 11, the atmosphere communication valve 9 is closed and the supply valve 3 is opened. In the state shown in FIG. 12, the pressing portion 20 a of the first cam 20 presses the end portion (right end portion in the figure) of the atmospheric valve lever 21 against the urging force of the compression spring 23. As a result, the atmosphere communication port 8a is closed by the atmosphere communication valve 9 provided at the other end (the left end in the figure) of the atmosphere valve lever 21. The pressing portion 25a of the second cam 25 is in a state of being separated from the supply valve lever 27, and the supply valve lever 27 is in contact with the circular outer peripheral surface of the cam 25 by the biasing force of the spring. At this time, one end portion (left end portion in the figure) of the supply valve lever 27 is in a state where the supply valve 3 is not pressed, and the supply valve 3 is kept open.

  Here, when the drive gear 14a is rotated in the S2 direction by the motor 14, the idle gear 15 meshed with the drive gear is rotated. Due to the rotation of the idle gear 15, the planetary gear 16 meshing with the idle gear 15 moves in the R1 direction and meshes with the gear 24 as shown in FIG. By continuing to drive the motor 14 after that, the gear 16 rotates around its rotation center, the pressing portion 25a moves to a position facing the supply valve lever 27, and the end of the supply valve lever 27 (Right end in the figure) is pressed against the compression spring 28. Thereby, the other end part (the left end part in the figure) of the supply valve lever 27 presses the supply valve 3 to put the supply valve 3 in a closed state.

  When the motor 14 is driven to rotate the drive gear 14a in the S1 direction, the planetary gear 16 moves in the R2 direction with the rotation of the idle gear 15 and meshes with the gear 19. Thereafter, by continuously driving the motor 14, the planetary gear 16 rotates through the idle gear 15, and the gear 19 and the cam 20 rotate in conjunction with the rotation. By the rotation of the cam 20, the pressing portion 20 a presses the end portion of the atmospheric valve lever 21 against the compression spring 23 to rotate the atmospheric valve lever 21 around the fulcrum 22. The atmospheric communication valve 9 moves with the movement of the atmospheric valve lever 21 and closes the atmospheric communication port 8a that has been open until then.

  When the drive mechanism 30 operates as described above, the supply valve 3 is closed and the atmospheric communication valve 9 is closed, so that the supply valve 3 to the suction pump 31 are sealed. By performing suction with the suction pump 31 in this state, the negative pressure inside the sealed space increases. In this embodiment, the suction pump 31 is a tube pump using a tube, and the maximum negative pressure value has a limit value determined by the restoring force of the tube of the tube pump. In the present embodiment, the suction pump 31 as a tube pump is increased in negative pressure until the pressure in the recording head 1 becomes 0.8 atm.

  When the negative pressure increases to the maximum negative pressure value in the sealed space in the area closer to the recording head than the communication port 4b1 of the supply valve 3 in the recording head 1, the supply tube 2, and the sub tank 4, the supply valve 3 is opened (S302). .

  The operation of each part of the drive mechanism 30 at this time will be described. Here, the supply valve 3 is closed and the atmospheric communication valve 9 is closed as shown in FIG. 11, and the supply valve 3 is opened and the atmospheric communication valve 9 is closed as shown in FIG. Become.

  At this time, the motor 14 is driven and the drive gear 14a is rotated in the S2 direction. As the idle gear 15 rotates in conjunction with the rotation of the drive gear 14a, the planetary gear 16 moves in the R1 direction and meshes with the gear 24. Even after the planetary gear 16 and the gear 24 are engaged, the driving gear 14 continues to rotate by the driving force of the motor 14, whereby the planetary gear 16 rotates about its rotation center and rotates the gear 24. As a result, the pressing portion 25a of the cam 25 is separated from the supply valve lever 27, and the supply valve lever 27 rotates about the fulcrum 26 in the clockwise direction in FIG. As a result, the supply valve lever 27 releases the pressing force against the supply valve 3, and the supply valve 3 returns to a state in which the supply valve 3 is opened by its own restoring force.

  At this time, since the air communication valve 9 is closed, the ink is supplied from the main tank 5 to the supply path 10 of the sub tank 4 when the supply valve 3 is opened. At this time, when ink is supplied from the main tank 5 into the sub tank 4, a negative pressure is formed in the main tank 5. 12 through the main tank 5. Therefore, as air flows into the main tank 5, the negative pressure in the main tank 5 decreases, and the pressure in the main tank 5 returns to the original.

  FIG. 12 shows a cross-sectional view of the sub tank 4 in a state where the negative pressure in the sub tank 4 and the main tank 5 is eliminated. When the first step is performed, the first hollow tube 11 serving as an ink flow path between the main tank 5 and the sub tank 4 is filled with ink, and the first hollow tube 11 is filled with ink. become. In the first step, the ink can be filled to such an extent that the space formed when the supply valve 3 is expanded is filled. Thus, after the supply valve 3 is once closed and the suction pump 31 is driven in this state to increase the negative pressure in the recording head 1 and the supply tube 2, the supply valve 3 is opened and the sub tank 4 is opened. Hereinafter, the process of introducing ink into the valve is referred to as valve closing suction.

  In the present embodiment, with respect to the first suction for filling the first hollow tube 11 between the main tank 5 and the sub tank 4 with ink, the first hollow tube 11 is filled by performing valve closing suction. The method for filling ink has been described. However, for the first suction of the first step, the recording head is sealed with the suction cap 34, and the suction pump 31 suctions with the supply valve 3 opened and the air communication valve 9 closed. The recording head may be sucked by a suction method. In this embodiment, the method of increasing the negative pressure up to the maximum negative pressure in the state where the recording head is sealed when the valve is closed and sucked has been described. It doesn't matter. In the first step, it is sufficient that at least a negative pressure required for flowing ink from the main tank to the sub tank through the first hollow tube 11 is formed.

  Next, the operation of the ink supply system when performing valve closing suction for the second and subsequent times after the first step is completed will be described. FIG. 13A shows a state immediately after the first step for filling the first hollow tube 11 in the flow path between the main tank 5 and the sub tank 4 and the supply path 10 in the sub tank 4 is performed. A schematic cross-sectional view of the sub-tank 4 showing this state is shown. FIG. 13B shows a schematic cross-sectional view of the sub tank 4 in a state in which the air communication valve 9 is opened and the sub tank 4 is filled during the closed valve suction. FIG. 13C is a schematic cross-sectional view of the sub tank 4 showing a state after the valve closing suction is performed and then the negative pressure in the main tank 5 and the sub tank 4 is released.

  As shown in FIG. 13A, immediately after the first step is performed, the ink flows into the area closer to the recording head than the communication port 4b1 of the supply valve 3 in the sub tank 4, and a part of the supply tube 2 is obtained. Are filled with ink. After the first step is performed, since the supply valve 3 is in an open state and the atmospheric communication valve 9 is closed, the negative pressure in the supply channel is eliminated after the suction pump 31 is driven. Until then, the supply tube 2 is filled with ink from the main tank 5 through the sub tank 4.

  Subsequently, the valve closing suction is performed again. Subsequent to the first valve closing suction, the ejection port surface of the recording head 1 remains covered with the suction cap. When valve suction is performed for the second and subsequent times, as shown in FIG. 13B, the supply valve 3 is changed from the open state to the closed state (S303), and the atmosphere communication valve 9 is changed from the closed state. An open state is set (S304).

  The operation of each part of the drive mechanism 30 at this time will be described. Here, from the state where the supply valve 3 is opened and the atmospheric communication valve 9 is closed as shown in FIG. 13 (a), the supply valve 3 is closed and the atmospheric communication valve 9 is closed as shown in FIG. 13 (b). Will be open.

  First, when the drive gear 14a is rotated in the S2 direction by the motor 14, the idle gear 15 meshed with the drive gear is rotated. Due to the rotation of the idle gear 15, the planetary gear 16 meshing with the idle gear 15 moves in the R1 direction and meshes with the gear 24. By continuing to drive the motor 14 after that, the gear 16 rotates around its rotation center, the pressing portion 25a moves to a position facing the supply valve lever 27, and the end of the supply valve lever 27 (Right end in the figure) is pressed against the compression spring 28. Thereby, the other end part (the left end part in the figure) of the supply valve lever 27 presses the supply valve 3, and the supply valve 3 is closed.

  Next, the motor 14 is driven, and the drive gear 14a is rotated in the S1 direction. The rotational force of the drive gear 14a is transmitted to the planetary gear 16 through the idle gear 15, and the planetary gear 16 rotates about its rotation center axis. As the idle gear 15 rotates, the planetary gear 16 moves in the R2 direction. To mesh with the gear 19. The rotation of the planetary gear 16 causes the first cam 20 to rotate together with the gear 19 engaged therewith, and the pressing portion 20a is separated from the end portion (right end portion) of the atmospheric valve lever 21. As a result, the atmospheric valve lever 21 is rotated counterclockwise in FIG. 11 around the fulcrum 22 by the elastic force of the compression spring 23, and the atmospheric communication valve 9 is moved from a position where the atmospheric communication port 8a is closed. Thereby, the atmosphere communication port 8a is opened to the atmosphere.

  By driving the drive mechanism 30 in this way, the area closer to the recording head 1 than the communication port 4b1 of the supply valve 3 in the recording head 1, the supply tube 2 and the sub tank 4 becomes a closed area, and the area is sealed. It becomes the state. Then, the suction pump 31 is driven to suck ink, whereby the negative pressure in the supply path increases (S305). Then, by driving the suction pump 31 in a state where the supply valve 3 is closed and the inside of the recording head 1 and the supply tube 2 is sealed, the negative pressure is increased to the maximum value in this region in the sealed region on the recording head 1 side. It is done. Further, while the suction pump 31 is driven and the negative pressure in the sealed area on the recording head 1 side is increased, ink is continuously filled into the sub tank 4 (negative pressure forming step).

  The interior of the first hollow tube 11 as a flow path between the main tank 5 and the sub tank 4 is already filled with ink when the first step is performed. In the present embodiment, the sub tank 4 is disposed on the lower side of the main tank 5 in the gravity direction. Further, normally, the second hollow tube 12 and the buffer chamber 6 are not filled with ink, and the buffer chamber 6 side is balanced with the atmospheric pressure on the bottom surface of the main tank 5. Accordingly, there is a water head difference between the ink stored in the main tank 5 and the ink stored in the sub tank 4. Further, since the supply path 10 in the sub tank 4 is formed with a sufficiently small inner diameter, when the liquid level of the ink supplied from the main tank 5 to the sub tank 4 is inside the supply path 10, Capillary force acts. Therefore, when the first hollow tube 11 is filled with ink, the flow of ink in the direction from the main tank 5 to the sub-tank 4 is promoted by the action of capillary force and the water head difference due to gravity. Ink is filled.

  As shown in FIG. 13B, the main tank 5 is increased by the capillary force in the supply passage 10 and the water head difference between the main tank 5 and the sub tank 4 while increasing the negative pressure inside the supply tube 2 and the recording head 1. The process of supplying the ink inside to the sub tank 4 is referred to as a second step. In the present embodiment, the time for supplying ink to the sub tank 4 while increasing the negative pressure inside the supply tube 2 and the recording head 1 by the suction pump 31 in the second step is about 40 s. In this embodiment, the water head difference between the bottom surface of the main tank 5 and the highest position in the gravity direction in the sub tank 4 is about 20 mm, and the ink filling speed from the main tank 5 to the sub tank 4 at that time is as follows. About 0.15 cc / s.

  The purpose of the second step is to let the ink naturally fall from the main tank 5 into the sub tank 4 due to the difference in water head, and mainly fill the sub tank 4 with ink.

  Next, after the negative pressure in the recording head 1 and the supply tube 2 is increased, as shown in FIG. 13C, the atmosphere communication valve 9 is changed from the open state to the closed state (S306), and the supply valve 3 Is changed from the closed state to the open state (S307).

  The operation of each part of the drive mechanism 30 at this time will be described. Here, from the state where the supply valve 3 is closed and the atmospheric communication valve 9 is opened as shown in FIG. 13B, the supply valve 3 is opened and the atmospheric communication valve 9 is opened as shown in FIG. Is closed.

  First, when the motor 14 is driven to rotate the drive gear 14a in the S1 direction, the planetary gear 16 moves in the R2 direction as the idle gear 15 rotates, and meshes with the gear 19. Thereafter, by continuously driving the motor 14, the planetary gear 16 rotates through the idle gear 15, and the gear 19 and the cam 20 rotate in conjunction with the rotation. By the rotation of the cam 20, the pressing portion 20 a presses the end portion of the atmospheric valve lever 21 against the compression spring 23 to rotate the atmospheric valve lever 21 around the fulcrum 22. The atmospheric communication valve 9 moves with the movement of the atmospheric valve lever 21 and closes the atmospheric communication port 8a. Then, with the atmosphere communication valve 9 closing the atmosphere communication port 8a, the motor 14 is driven and the drive gear 14a is rotated in the direction S2. As the idle gear 15 rotates in conjunction with the rotation of the drive gear 14a, the planetary gear 16 moves in the R1 direction and meshes with the gear 24. Even after the planetary gear 16 and the gear 24 are engaged, the driving gear 14 continues to rotate by the driving force of the motor 14, whereby the planetary gear 16 rotates about its rotation center and rotates the gear 24. As a result, the pressing portion 25a of the cam 25 is separated from the supply valve lever 27, and the supply valve lever 27 rotates around the fulcrum 26 in the clockwise direction in FIG. As a result, the supply valve lever 27 releases the pressing force against the supply valve 3, and the supply valve 3 returns to a state in which the supply valve 3 is opened by its own restoring force.

  As a result, the negative pressure increased in the recording head 1 and the supply tube 2 causes the supply valve 3 in the sub tank 4 to flow in the ink supply direction in which ink is supplied from the main tank 5 to the recording head 1 via the sub tank 4. It extends downstream from the communication port 4b1. Ink is introduced into the supply path from the main tank 5 through the sub tank 4, and ink also flows into the supply tube 2. In this way, in the second valve closing suction, the step of changing the atmosphere communication valve 9 from the open state to the closed state and then turning the supply valve 3 from the closed state to the open state is referred to as a third step (negative pressure release step). .

  When the supply valve 3 is opened in the third step, the ink level in the sub tank 4 reaches a position higher than the supply port 33 to the recording head 1 where the sub tank 4 and the supply tube 2 communicate with each other. ing. Therefore, when the supply valve 3 is opened, the ink is vigorously supplied from the sub tank 4 to the supply tube 2 on the recording head 1 side by the negative pressure that has been increased. At this time, since the liquid level of the ink in the sub tank 4 is higher than the supply port 33 to the supply tube 2 where the inside of the sub tank 4 and the supply tube 2 communicate with each other, the air in the sub tank 4 flows into the supply tube 2. There is almost no inflow. Then, since the atmospheric communication valve 9 is closed, the negative pressure increased in the recording head 1 and the supply tube 2 propagates into the main tank 5 through the sub tank 4. The negative pressure in the sub tank 4 is reduced and eliminated by supplying ink from the main tank 5 to the sub tank 4. When this negative pressure propagates into the main tank 5, the air taken into the buffer chamber 6 through the atmospheric communication passage 7 is supplied into the main tank 5, and the negative pressure in the main tank 5 is reduced. Balanced with atmospheric pressure. In this way, ink is supplied from the main tank 5 to the supply path 2 via the sub tank 4 until the increased negative pressure in the recording head 1 and the supply tube 2 is eliminated.

  The supply tube 2 has a small inner diameter and a relatively large flow path resistance. Therefore, when ink is circulated in the supply tube 2 when ink is filled, it is required to move the ink in the supply tube 2 by applying a relatively large force to the ink in the supply tube 2. Therefore, in this embodiment, the suction pump 31 is driven with the supply valve 3 closed, and ink is circulated in the supply tube 2 by forming a relatively large negative pressure in the recording head 1 and the supply tube 2. I am going to do that.

  By repeating the second step and the third step, the sub tank 4, the supply tube 2 up to the recording head 1 and the recording head 1 are filled with ink, and these areas can be filled with ink. In the second step, the purpose is mainly to fill the sub tank 4 with ink, whereas in the third step, the ink in the sub tank 4 is sucked by the suction pump 31 so that the recording head 1 and The purpose is to fill the supply tube 2 with ink.

  In this embodiment, the capacity of the sub tank 4 is about 20 cc. At this time, in one valve closing suction, about 6 cc of ink can be filled in 40 s in the time for forming the negative pressure and filling the ink. Therefore, after the first step to the third step are once performed, the valve closing suction performed by the second step and the third step is repeatedly performed about 2 to 3 times, so that the sub tank 4 is substantially filled. it can.

  As described above, in this embodiment, whether a predetermined voltage is applied between the hollow tube 11 and the solid tube 13, and the hollow tube 11 and the solid tube 13 are energized. Whether or not the liquid level of the ink in the sub tank 4 has reached the solid tube 13 is detected. If it is detected that the space between the hollow tube 11 and the solid tube 13 is energized by applying a voltage between the hollow tube 11 and the solid tube 13, and it is detected that the ink level has reached the solid tube 13, It is determined that a sufficient amount of ink has been filled in the sub tank 4, and the filling of the ink in the sub tank 4 is terminated. FIG. 15 shows a state in which the ink level is in contact with the solid tube 13 in the sub tank 4. In this embodiment, ink level detection means is provided in the sub-tank 4 and the end of ink filling is determined according to the detection result of the detection means. However, the present invention is not limited to this. . For example, the filling of the ink into the sub tank 4 may be terminated by repeating the valve closing suction until the valve closing suction is performed for a predetermined time without using the ink level detection means. Further, it may be determined that the ink filling process into the sub tank 4 is completed by repeating the valve closing and sucking a predetermined number of times.

  In the present embodiment, whether or not the recording head 1 is filled with ink is determined by detecting the presence or absence of ink in the recording head and detecting an ejection failure (not shown) as a sensor for detecting an ejection port where ejection failure occurs. It can be determined by means.

  As described above, the recording apparatus of the present embodiment can detect that the sub tank 4 is sufficiently filled with ink and the ink level has reached the solid tube 13, and the recording head 1 has sufficient ink. It can detect filling. At this time, when the ink filling into the recording head 1 and the supply tube 2 and the ink filling into the sub tank 4 are completed almost at the same time, only several operations of the second step and the third step are performed. This completes the filling operation.

  If the ink is already filled in the supply tube 2 and the recording head 1 before the sub tank 4 is filled with ink, only the ink filling process into the sub tank 4 is performed thereafter. In the present embodiment, the step of filling the sub tank 4 with ink is performed by the above-described method of filling the sub tank 4 with the ink when the main tank 5 is replaced (S309).

  When the ink filling into the sub tank 4 is completed before the supply tube 2 and the recording head 1 are filled with the ink, the suction pump 31 is driven with the air communication valve 9 closed and the supply valve 3 opened. A filling process to the ink flow path 2 and the recording head 1 is performed (S308). At this time, the suction pump 31 is driven while the atmospheric communication valve 9 and the supply valve 3 are closed to increase the negative pressure in the recording head 1 and the supply tube 2, and then the atmospheric communication valve 9 is closed. The supply valve 3 may be opened as it is. As described above, the ink in the main tank 4 may be sucked by the negative pressure increased in a state where the supply valve 3 is closed.

  As described above, in the present embodiment, the first hollow tube 11 between the main tank 5 and the sub tank 4 is once filled with ink in the first step, and the atmosphere communication valve 9 is opened in the second step. The suction pump 31 is driven with the supply valve 3 closed. Accordingly, while the ink flow path between the recording head 1 and the supply valve 3 is closed in the second step, a high negative pressure is formed in the recording head 1 and the supply tube 2 by driving the suction pump 31. Ink can be filled into the sub tank 4 from the main tank 5. Accordingly, the step of forming a high negative pressure for filling the recording head 1 and the supply tube 2 with the ink and the step of filling the sub tank 4 with the ink can be simultaneously performed in parallel. Therefore, ink can be filled faster than when these steps are performed separately. This makes it possible to quickly complete the process of filling the recording head 1, the supply tube 2 and the sub tank 4 with ink in the initial state of the recording apparatus such as when the recording apparatus is first used when not in use. As a result, the recording head 1, the supply tube 2, and the sub tank 4 are filled with ink in the initial state of the recording apparatus, so that the state in which recording cannot be performed can be shortened. . Thereby, it can suppress making a user feel troublesome.

  Further, in the present embodiment, the suction pump 31 as a tube pump that can originally perform suction recovery is used as a suction pump that is driven to form a high negative pressure in the recording head 1 and the suction tube 2. Yes. The suction pump that performs suction recovery in this manner is conventionally attached to a recording apparatus, and a negative pressure is formed in the recording head 1 and the supply tube 2 by using an existing suction pump. Therefore, it is not necessary to install a new pump in order to form a negative pressure in the recording head 1 and the supply tube 2. For this reason, in order to form a negative pressure in the recording head 1 and the supply tube 2, it can suppress that a manufacturing cost increases. Further, even when the suction force is insufficient by simply driving the suction pump, the negative pressure in the recording head 1 and the supply tube 2 is increased by continuing to drive the suction pump 31 with the supply valve 3 closed. be able to. Thereby, it is possible to form a negative pressure sufficient to introduce ink into the recording head 1 and the supply tube 2 while compensating for the lack of the original suction force.

  In the present embodiment, a drive source for driving a drive mechanism for exhausting air from the sub tank 4 and a supply valve 3 that is closed to form a high negative pressure in the recording head 1 and the supply tube 2 are provided. A common drive source is used for opening and closing. Originally, when the sub tank 4 is filled with ink, a drive source for driving an exhaust mechanism for removing air from the sub tank 4 is required, and in order to open and close the supply valve 3, A drive source for driving the drive mechanism is required. However, in this embodiment, even when ink is filled, the opening / closing operation of the supply valve 3 and the opening / closing operation of the air communication valve 9 are selectively operated by one drive source. Thus, the drive source for driving the opening / closing operation of the supply valve 3 and the drive source for driving the opening / closing operation of the atmospheric communication valve 9 for removing air from the sub tank 4 are performed by a single drive source. It is driven. Therefore, the structure of the recording apparatus is simplified, and the manufacturing cost of the recording apparatus can be kept low.

  Here, in order to shorten the time taken to fill the recording head 1 and the supply tube 2 with ink, it is conceivable to separately arrange pumps for filling ink in two different regions. That is, a pump for supplying the ink stored in the main tank 5 to the sub tank 4 and a pump for supplying the ink stored in the sub tank 4 into the supply tube 2 and the recording head 1 are separately arranged. Can be considered. However, when the pump for supplying ink from the main tank 5 to the sub-tank 4 and the pump for supplying ink in the sub-tank 4 to the supply tube 2 and the recording head 1 are arranged separately, the pump The number will increase. In general, a pump requires a configuration such as a driving source, a transmission mechanism for transmitting a driving force generated by the driving source, and an ink flow path. Therefore, the pump is a relatively expensive part among the parts forming the recording apparatus. Therefore, when the number of pumps increases, the manufacturing cost of the recording apparatus increases relatively. On the other hand, in the present embodiment, the suction pump 31 is only used to form a negative pressure inside the recording head 1 and the supply tube 2. Moreover, in this embodiment, the suction pump 31 is an existing pump that is attached to suck ink from the recording head 1 at the time of suction recovery. Therefore, in the recording apparatus, it is possible to introduce ink from the main tank 5 to the sub tank 4 and introduce ink into the recording head 1 and the supply tube 2 without using a new pump. Thus, it is possible to introduce ink from the main tank 5 to the sub tank 4 and to introduce ink into the recording head 1 and the supply tube 2, while suppressing an increase in manufacturing cost of the recording apparatus.

  In the present embodiment, if the ink in the recording head 1 and the supply tube 2 is once filled in the initial state such as when not in use, then the ink in the recording head 1 and the supply tube 2 decreases. Is unlikely to occur. Accordingly, if the recording head 1 and the supply tube 2 are filled once when not in use, it is usually unnecessary to fill the recording head 1 and the supply tube 2 with ink thereafter. However, when the recording head 1 and the supply tube 2 are not filled with ink for some unexpected reason, the ink of this embodiment is used even when it is not used for the first time when it is not used. The filling method may be used.

  In this embodiment, in the first step at the time of initial ink filling, the drive mechanism 30 drives the supply valve 3 so that the supply valve 3 is opened while the atmospheric communication valve 9 is closed. It was. However, the present invention is not limited to this, and in the initial state where the main tank 5 and the sub tank 4 are not mounted, the atmosphere communication valve 9 and the supply valve 3 may be originally closed.

  In the present embodiment, when the drive mechanism 30 opens the supply valve 3 in the third step to supply ink from the sub tank 4 to the supply tube 2 and the inside of the recording head 1, the ink in the sub tank 4 is discharged. The liquid level is located above the supply port 33 in the gravity direction. Thereby, when the ink is filled into the supply tube 2 and the recording head 1, the liquid level of the sub tank 4 is higher than the supply port 33, so that air enters the supply tube 2 and the recording head 1. That can be suppressed.

  In the present embodiment, the operation of the supply valve 3 and the opening and closing of the atmospheric communication valve 9 are performed by urging the atmospheric valve lever 21 and the supply valve lever 27 with springs, and changing the rotation direction of the motor 14, It is operated by changing the meshing gear. However, the present invention is not limited to this embodiment, and the opening and closing of the supply valve 3 and the opening and closing of the atmospheric communication valve 9 may be performed by other methods. For example, two motors for driving the gears 19 and 24 may be attached, and the gears 19 and 24 may be driven by the respective motors.

  In addition, the recording apparatus of the present embodiment is a tube supply type, and a so-called serial scan type recording apparatus that records an image with movement of the recording head in the main scanning direction and conveyance of the recording medium in the sub-scanning direction is used. However, the present invention is not limited to this form. The present invention can also be applied to a full-line recording apparatus that uses a recording head that extends over the entire width of the recording medium without scanning the recording head.

DESCRIPTION OF SYMBOLS 1 Recording head 3 Supply valve 4 Sub tank 5 Main tank 8a Atmospheric communication port 9 Atmospheric communication valve 30 Drive mechanism

Claims (11)

A recording head that performs recording by discharging liquid supplied from a first ink tank that is detachably mounted on the recording apparatus main body;
The first ink tank is disposed below the first ink tank in the direction of gravity, and the liquid supplied from the first ink tank to the recording head is temporarily stored between the first ink tank and the recording head. A possible second ink tank;
In an inkjet recording apparatus comprising:
Negative pressure forming means capable of forming a negative pressure inside the recording head;
A supply valve provided in the second ink tank and capable of communicating and blocking a flow path of a liquid supplied to the recording head;
An atmosphere communicating portion for communicating the inside of the second ink tank and the atmosphere;
An atmospheric communication valve capable of closing the atmospheric communication portion;
A drive mechanism for driving the supply valve and the atmosphere communication valve;
With the drive mechanism closing the supply valve and blocking the liquid flow path, the negative pressure forming means continues to form a negative pressure inside the recording head,
In parallel with the negative pressure forming means continuing to form a negative pressure inside the recording head, the second ink tank is moved from the first ink tank to the second ink tank with the driving mechanism opening the air communication valve. Supply liquid to
An ink jet recording apparatus, wherein the drive mechanism supplies the liquid to the recording head from the second ink tank by opening the supply valve.   Before the drive mechanism supplies liquid from the first ink tank to the second ink tank with the atmosphere communication valve opened, the drive mechanism closes the atmosphere communication valve and In the opened state, the negative pressure forming means forms a negative pressure inside the recording head to fill the liquid between the first ink tank and the second ink tank. The ink jet recording apparatus according to claim 1.   Before the drive mechanism supplies liquid from the first ink tank to the second ink tank with the atmosphere communication valve opened, the drive mechanism temporarily closes the atmosphere communication valve and supplies the supply. With the valve closed, the negative pressure generating means continues to generate a negative pressure inside the recording head, and then the drive mechanism opens the supply valve, and the first ink tank and the second ink tank are opened. The ink jet recording apparatus according to claim 1, wherein a liquid is filled between the ink tank and the ink tank.   4. The ink jet recording apparatus according to claim 1, wherein the negative pressure forming unit is a suction pump capable of applying a negative pressure to the inside of the recording head.   When the drive mechanism supplies the liquid from the second ink tank to the recording head by opening the supply valve, the liquid level of the second ink tank is changed from the second ink tank to the recording head. 5. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is located above a supply port for supplying a liquid to the recording head in a direction of gravity.   6. The drive mechanism according to claim 1, wherein the drive mechanism is driven by a single drive source and selectively activates an opening / closing operation of the supply valve and an opening / closing operation of the atmospheric communication valve. Inkjet recording apparatus.   In the driving mechanism, a gear that transmits a driving force from a driving source selectively moves between a gear that operates the supply valve and a gear that operates the atmospheric communication valve, and changes a meshing gear. The ink jet recording apparatus according to claim 1, wherein either the opening / closing operation of the supply valve or the opening / closing operation of the atmospheric communication valve is selectively performed.   When the drive mechanism supplies the liquid from the second ink tank to the recording head by opening the supply valve, the liquid level inside the second ink tank is the second ink tank. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus reaches a position higher than a supply port for supplying liquid to the recording head. A recording head that performs recording by discharging liquid supplied from a first ink tank that is detachably mounted on the recording apparatus main body;
The first ink tank is disposed below the first ink tank in the direction of gravity, and the liquid supplied from the first ink tank to the recording head is temporarily stored between the first ink tank and the recording head. A liquid filling method in an initial state of the ink jet recording apparatus, wherein the second ink tank is filled with a liquid.
The ink jet recording apparatus comprises:
Negative pressure forming means capable of forming a negative pressure inside the recording head;
A supply valve provided in the second ink tank and capable of communicating and blocking a flow path of a liquid supplied to the recording head;
An atmosphere communicating portion for communicating the inside of the second ink tank and the atmosphere;
An atmospheric communication valve capable of closing the atmospheric communication portion;
A drive mechanism for driving the supply valve and the atmosphere communication valve;
In parallel with the drive mechanism closing the supply valve and blocking the liquid flow path, the negative pressure forming means continues to form a negative pressure inside the recording head. A negative pressure forming step of supplying liquid from the first ink tank to the second ink tank with the atmosphere communication valve opened;
A liquid filling method in an initial state of an ink jet recording apparatus, comprising: a negative pressure releasing step in which the driving mechanism opens the supply valve to supply liquid from the second ink tank to the recording head.   In the negative pressure forming step, before supplying the liquid from the first ink tank to the second ink tank in a state where the driving mechanism opens the atmospheric communication valve, the driving mechanism causes the atmospheric communication valve to In a state where the supply valve is opened, the negative pressure forming means forms a negative pressure inside the recording head so that liquid is supplied between the first ink tank and the second ink tank. The liquid filling method in an initial state of the ink jet recording apparatus according to claim 9, wherein filling is performed.   In the negative pressure releasing step, before the liquid is supplied from the first ink tank to the second ink tank in a state in which the driving mechanism opens the atmospheric communication valve, the driving mechanism temporarily performs the atmospheric communication. With the valve closed and the supply valve closed, the negative pressure forming means continues to form a negative pressure inside the recording head, and then the drive mechanism opens the supply valve, and the first The ink filling method according to claim 9, wherein ink is filled between the ink tank and the second ink tank.

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