JP2010137380A - Liquid ejecting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording apparatus which can stably eject an ink having a constant ejection amount during ejection. <P>SOLUTION: The liquid ejecting apparatus impresses a proper negative pressure to a foaming liquid by positively controlling a negative pressure of the foaming liquid supplied to a recording head. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid ejection apparatus using a liquid ejection head that ejects a desired liquid by the generation of bubbles due to thermal energy or the like, and more particularly, to a liquid ejection head having a movable separation membrane that is displaced using the generation of bubbles. The present invention relates to the liquid ejection device used.

  In this specification, “recording” means not only adding a meaningful image such as a character or a figure to a recording medium, but also adding a meaningless image such as a pattern. It also means that.

  By applying energy such as heat to the ink, the ink undergoes a state change accompanied by a steep volume change (bubble generation), and the ink is ejected from the discharge port by the action force based on this state change to the recording medium. Inkjet recording methods for recording by attaching are known. In a recording apparatus using this ink jet recording method, an ejection port provided in a recording head that ejects ink, an ink channel communicating with the ejection port, and an ejection energy generating unit disposed in the ink channel A heating element (electrothermal converter) is generally provided.

  According to such a recording method, a high-quality image can be recorded at high speed and with low noise, and in the recording head used for this recording, the ejection ports for ejecting ink are arranged at high density. Can do. Therefore, a recording method that employs an ink jet recording method has many excellent points such as a high-resolution recorded image and a color image can be easily obtained with a small apparatus. For this reason, in recent years, this ink jet recording method has been used in many office devices such as printers, copiers, and facsimiles, and has also been used in industrial systems such as textile printing apparatuses.

  However, in the conventional ink jet recording method, since heating is repeated while the heating element is in contact with ink, deposits due to scorching of ink may occur on the surface of the heating element. In addition, when the liquid to be discharged is a liquid that is likely to be deteriorated by heat or a liquid in which sufficient foaming is difficult to be obtained, the direct heating bubble formation by the above-described heating element may not perform good discharge. .

  Therefore, Patent Document 1 proposes a method of discharging the discharge liquid by foaming the foam liquid with thermal energy through a flexible film that separates the foam liquid and the discharge liquid. The configuration of the flexible film and the foaming liquid in the method of Patent Document 1 is such that the flexible film is provided in a part of the nozzle. On the other hand, Patent Document 2 discloses a configuration using a large film that vertically separates the entire recording head. This large film is provided for the purpose of preventing the liquids in the two liquid paths from being mixed with each other by being sandwiched between the two plate members forming the liquid path.

  Patent Document 3 discloses a technique using a liquid having a boiling point lower than that of the discharged liquid as a characteristic of the foamed liquid itself and taking foaming characteristics into consideration, and Patent Document 4 discloses conductivity. A technique of using a liquid having a liquid as a foaming liquid is disclosed.

  Further, in Patent Document 5 and Patent Document 6, the separation membrane in the liquid discharge head is sandwiched between the first liquid flow path wall and the second liquid flow path wall, and the movable area per nozzle is the liquid flow path. It is regulated by the wall. That is, it is disclosed that the first and second liquid flow path walls regulate the displacement of the film and have a great influence on the liquid discharge head characteristics.

  As a result, the discharge efficiency is affected, and the return mechanism of the film itself is also affected. Therefore, it is important that the membrane itself, not the liquid flow path wall, regulate the displacement and smooth the displacement of the membrane, so that it always has a highly reliable discharge performance. Then, the membrane is made a separation membrane that does not substantially extend, and by providing a recess in the separation membrane, the displacement amount of the recess corresponds to the discharge amount of the discharge liquid, that is, the discharge amount corresponds to the displacement amount of the recess of the separation membrane. become. Therefore, by defining the amount of displacement of the recess, stable discharge can be obtained regardless of the type of supply liquid. Further, it is shown that the durability of the separation membrane is improved if the displacement amount of the concave portion of the separation membrane is defined so that the concave portion does not expand and contract at the maximum displacement. Furthermore, it is also shown that if the restoring force is exerted when energy for displacement is not applied to the recess, the refill of the discharged liquid is also improved.

JP-A-55-81172 JP 59-26270 A JP-A-5-229122 JP-A-4-329148

  However, in the liquid discharge head that discharges the discharge liquid by foaming the foam liquid with thermal energy through the separation film provided with the recess for separating the foam liquid and the discharge liquid as described above, the following points are raised as problems. It was done. That is, the foaming liquid is foamed by thermal energy, and the concave portion of the separation membrane is displaced toward the discharge liquid, but the restoring force of the separation membrane when energy for subsequent defoaming or displacement is not applied must depend on natural recovery. . This makes it difficult to always return to a certain position in a stable manner until the next foaming, which may cause unstable discharge of the discharge liquid.

  From another point of view, even when a recess is provided in the separation membrane, when a wide variety of liquids are used as the discharge liquid, the discharge amount of the liquid discharged from the discharge port by energy such as heat depends on the type of the liquid. Variation occurs. This variation tends to increase as the viscosity becomes higher. This is because the once-displaced separation membrane is not always in a constant state until the next foaming and discharging, which causes the variation in the discharge amount to be further increased.

  Accordingly, an object of the present invention is to realize a recording apparatus (liquid ejecting apparatus) capable of ejecting ink stably with a constant ejection amount during ejection.

  For this reason, the liquid ejection apparatus according to the present invention is configured such that the first flow path through which the first liquid ejected onto the recording medium flows, the second liquid flows, and the separation film provided with a movable portion is used for the first flow. In a liquid ejection apparatus comprising: a recording unit including a second flow path separated from the path; and a transport unit configured to transport the recording medium, the pressure in the second flow path can be controlled. Pressure control means is provided, and the pressure in the second flow path is controlled to be lower than the pressure in the first flow path by the pressure control means.

  Further, the liquid ejection apparatus according to the present invention is configured such that the first flow path through which the first liquid ejected to the recording medium flows, and the second liquid flows through the separation membrane having a movable part. In a liquid ejection apparatus comprising a recording means having a second flow path separated from the flow path and a conveying means for conveying the recording medium, the pressure in the first flow path can be controlled. Pressure control means capable of controlling the pressure in the second flow path, and by the pressure control means, the pressure in the second flow path is higher than the pressure in the first flow path. The pressure is controlled to be low.

  According to the present invention, the pressure control means capable of controlling the pressure in the second flow path is provided, and the pressure control means allows the pressure in the second flow path to be higher than the pressure in the first flow path. Control low. Accordingly, it is possible to realize a recording apparatus (liquid ejecting apparatus) capable of ejecting ink stably with a constant ejection amount during ejection.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

(Basic configuration)
(Outline of image forming system)
FIG. 1 and FIG. 2 are a block diagram and a schematic perspective view, respectively, showing an outline of a composite printing system using a liquid ejection apparatus (hereinafter also referred to as a recording apparatus) of the present embodiment. The composite printing system includes an information processing apparatus 100 and a recording unit 200. The recording unit 200 includes a medium transport device 117 and a plurality of recording devices 116-1 to 116-5 (hereinafter also collectively referred to as a recording device 116). It has. The information processing apparatus 100 is a supply source of image data to be formed. The information processing apparatus 100 divides one image into regions and supplies the divided image data to the recording unit 200. The medium transport device 117 transports a recording medium 206 (see FIG. 2) having a size in the width direction corresponding to the recordable range of the recording device 116, and detects an end (paper end) of the recording medium 206. The recording device 116 outputs a signal for defining the recording start position.

  Each recording unit 200 independently performs a recording operation (recording operation) on the recording area in charge at a timing defined by the medium transport device 117 based on the divided image data supplied from the information processing apparatus 100. Execute. Each recording unit has a recording head for ejecting black (K) ink to the three primary colors of yellow (Y), magenta (M), and cyan (C) in order to perform full color recording on the recording medium 206. It is installed. Each recording head is supplied with ink of each color from ink tanks 2203Y, 2203M, 2203C, and 2203K, which are ink supply sources, and similarly, foam liquid tanks 203Y, 203M, 203C, which are foam liquid supply sources. A foaming liquid is supplied from 203K.

  In FIG. 1, a CPU 101 is a central processing unit that controls system control of the information processing apparatus 100 in general. In the information processing apparatus 100, the CPU 101 executes processing defined by an application program for generating and editing image data, an image division program, a control program for a plurality of recording units, a control program for a medium transport device 117 described later, and the like.

  The system bus of the CPU 101 has a hierarchical bus configuration. For example, the system bus is connected to a PCI bus as a local bus via the host / PCI bridge 102 and further connected to the ISA bus via the PCI / ISA bridge 105. Connected to devices on each bus.

  The main memory 103 is a RAM provided with a temporary storage area for an operating system (OS), application programs, and control programs, and is also used as a working memory area for executing each program. These programs are read from, for example, the hard disk drive HDD 104 and loaded. The system bus has a high-speed memory using an SRAM called a cache memory 120, and codes and data that are always accessed by the main CPU 101 are stored here.

  The ROM 112 is a program for controlling input / output devices such as a keyboard 114, a mouse 115, a CDD 111, and an FDD 110 connected via an input / output circuit (not shown), an initialization program when the system is powered on, a self-diagnosis program, and the like. Is stored. The EEPROM 113 is a non-volatile memory for storing various parameters used permanently.

  The communication interface 109 with the recording device 116 is connected to the PCI bus, and usable interfaces include, for example, a bidirectional Centronics interface compliant with the IEEE1284 standard, USB, hub connection, and the like. FIG. 1 shows a configuration in which a hub 140 is connected via the communication interface 109, and the hub 140 is further connected to each of the recording device 116 and the medium transport device 117. Further, although the wired type communication interface 109 is used in this embodiment, a communication interface such as a wireless LAN may be used.

  Referring to FIG. 2 again, the information processing apparatus 100, the plurality of recording apparatuses 116, and the conveying apparatus 117 are connected via the hub 140, and transfer recording data, operation start and end commands, and the like. Further, each of the recording devices 116 and the conveying device 117 are also signal-connected to detect the leading end of the recording medium 206 or set the recording head position, the medium conveying speed, and the recording operation (ink ejection operation) in each recording device 116. Send and receive signals to synchronize.

  Four recording heads 811Y, 811M, 811C, and 811K for ejecting yellow (Y), magenta (M), cyan (C), and black (K) inks, respectively, to perform full color recording on each recording unit. The recording head is installed.

  The recording heads 811Y, 811M, 811C, and 811K in each recording apparatus 116 are supplied with ink of each color from the ink tanks 2203Y, 2203M, 2203C, and 2203K, which are ink supply sources, via the dedicated tubes 2204. Similarly to the ink, the foaming liquid is supplied from the foaming liquid tanks 203Y, 203M, 203C, and 203K, which are the foaming liquid supply source, via the dedicated tube 204.

(Recording device control system)
FIG. 3 is a diagram illustrating a configuration example of a control system in the recording apparatus 116 according to the present embodiment. The CPU 800 performs overall control of the recording device 116 according to a program or the like corresponding to a processing procedure described later. A RAM 803 is used as a ROM that stores the program and fixed data, and 805 is used as a working memory area. The EEPROM 814 is a memory for storing necessary parameters used by the CPU 800 for control even when the power of the recording apparatus is shut off.

  The interface controller 802 connects the recording device 116 to the information processing apparatus 100 via a USB cable, and the VRAM 801 develops each color image data. The memory controller 804 transfers the image data received by the interface controller 802 to the VRAM 801 and controls to read the image data according to the progress of recording. When the recording data is received from the information processing apparatus 100 via the USB cable to the interface controller 802, the CPU 800 analyzes a command added to the recording data and then instructs the VRAM 801 to develop the image data of the recording data. Do. In response to this instruction, the memory controller 804 writes the image data from the interface controller 802 to the VRAM 801 at high speed.

  The control circuit 810 controls the color recording heads 811Y, 811M, 811C, and 811K. The capping motor 809 is driven via an input / output port 806 and a drive unit 807 for a capping mechanism (not shown) for capping the surface of the recording head 811 where the ejection openings are formed. A pump motor (not shown) can change the pressurizing direction with respect to the liquid because it can drive the pump 48 inserted between the foaming liquid sub tank 40 and the recording head 811 described later (see FIG. 9). Motor. The solenoid is an actuator that drives the valve 35 described later (see FIG. 9), and the valve 35 can be controlled in an analog manner in an open / closed state by a PWM value set by the CPU 800 in the PWM circuit.

  A pump motor (not shown) different from the above controls the mechanical pump 36 by feeding back an output of a pressure sensor 49 (described later) provided near the flow path in the recording head (see FIG. 9) to the pump motor control unit. .

  Returning to FIG. 3, when the recording apparatus 116 is not used, the capping motor 809 is driven to move the recording heads 811Y, 811M, 811C, and 811K relative to the capping mechanism to perform capping. On the other hand, when the recording data to be recorded is developed in the VRAM 801, the capping motor 809 is driven, the recording head and the capping mechanism are moved relative to each other to release the capping state, and a recording start signal from the medium conveying device 117 is received. wait.

  An input / output (I / O) port 806 is connected to a motor drive unit 807, other drive means, and required sensors (not shown), and exchanges signals with the CPU 800. The synchronization circuit 812 receives the cueing signal of the recording medium and the position pulse signal synchronized with the movement of the medium from the medium conveying device 117, and generates a timing signal for executing the recording operation in synchronization with them appropriately. It is. That is, the data in the VRAM 801 is read at high speed by the memory controller 804 in synchronization with the position pulse accompanying the conveyance of the recording medium, and transferred to the recording head 811 via the recording head control circuit 810, so that color recording ( Recording).

(Conveyor configuration and control system)
The medium conveying device (hereinafter also simply referred to as a conveying device) 117 is suitable for conveying a recording medium having a predetermined size in the width direction and an arbitrary size in the conveying direction. In addition, a media stage 208 (see FIG. 2) is provided in order to restrict the recording surface of the recording medium 206 to be flat at a portion facing the recording head 810 of the recording device 116. Since the recording medium 206 having various thicknesses is used, means for improving the adhesion of the recording medium to the media stage 208 is added to make the recording surface flat even on thick paper or the like. May be. The transport motor 205 is a drive source for the transport roller row 205 </ b> A for transporting the recording medium in close contact with the upper surface of the media stage 208.

  FIG. 4 is a block diagram illustrating a configuration example of a control system of the medium transport device 117. The CPU 901 performs overall control of the medium transport device according to a program or the like corresponding to a processing procedure described later. The ROM 903 is a memory for storing programs and fixed data, and the RAM 904 is used as a work memory area. The interface 902 connects the medium transport device 117 to the information processing apparatus 100. The operation panel 905 includes an input unit for a user to input various instructions and inputs to the image forming apparatus and a display unit for performing a required display. In the present embodiment, the operation panel 905 is provided in the medium conveyance device. is there. As an example of means for improving the adhesion between the media stage 208 and the recording medium, the suction motor 908 performs suction through a large number of fine holes opened from the lower part of the media stage 208 to the conveying surface. It is the drive source of the vacuum pump which performs adsorption | suction. When a conveyance start command is received from the information processing apparatus 100 via the interface 902, the CPU 901 first activates the suction motor 908 and operates so that the recording medium 206 is attracted to the upper surface of the media stage 208.

  The drive unit 907 is a drive unit for driving the suction motor 908 and other required operating units. A drive circuit 909 is a drive circuit for the transport motor 205. The logic circuit 912 is a circuit for receiving the output of a rotary (rotary) encoder 910 provided on the shaft of the transport motor 205 and performing feedback control of the transport motor 205 to transport the recording medium at a constant speed. Here, the conveyance speed of the recording medium can be arbitrarily set by a speed instruction value written from the CPU 901 to the logic circuit 912. The rotary encoder 910 may be provided coaxially with the transport roller row 205A instead of the shaft of the transport motor 205.

  The logic circuit 912 also receives an output of a medium detection sensor 911 provided upstream in the transport direction from the recording position in order to detect that the leading end of the recording medium 206 has reached the vicinity of the recording start position. The logic circuit 912 outputs an appropriate recording instruction signal to each recording apparatus according to the distance in the transport direction from the position where the medium detection sensor 911 detects the leading edge of the recording medium to each recording apparatus. In the present embodiment, the recording devices 116-1 to 116-5 are arranged in two rows in the transport direction (arrow direction in FIG. 2), and the recording devices 116-1, 116-3, and 116-5 are arranged upstream in the transport direction. Are arranged, and recording apparatuses 116-2 and 116-4 are arranged on the downstream side. Therefore, the logic circuit 912 outputs two types of recording instruction signals 914 and 915. Considering that there is an error in the mounting position of the recording apparatus, the recording start signal 914 or 915 is independent for each recording apparatus according to the physical distance from the medium detection sensor 911 to each recording apparatus. You may make it add correction to.

  The logic circuit 912 appropriately converts the output of the encoder 910 to generate a recording medium position pulse 913, and each recording apparatus performs a recording operation in synchronization with the position pulse 913. Note that the resolution of the position pulse 913 may be appropriate, and may be set to a plurality of recording lines (rows), for example. Further, the configuration of the recording medium conveyance unit in the medium conveyance device 117 is not limited to the one having the fixed media stage 208 as shown in FIG. For example, an endless conveyance belt is provided between a pair of drums arranged upstream and downstream in the medium conveyance direction with respect to the recording position, and the recording medium is carried on the conveyance belt while the drum rotates. The recording medium may be transported by traveling of the transport belt. Further, the recording medium can be conveyed in any form of cut paper or continuous paper.

(Overview of image forming system operation)
FIG. 5 is a flowchart showing the mutual operation procedure of the information processing apparatus 100, the recording apparatus 116, and the medium transport apparatus 117. In order to execute recording in step S1001, the information processing apparatus 100 creates divided recording data for each recording apparatus and transmits the data. In step S <b> 1041, the recording device 116 releases the capping state in response to the reception of the divided recording data and develops data in the VRAM 801. When reception is completed in all the recording apparatuses 116-1 to 116-5, the information processing apparatus 100 transmits a conveyance start command to the medium conveyance apparatus 117 in step S <b> 1002. Thereafter, in step S <b> 1061, the medium transport device 117 drives the suction motor 908 according to the transmitted command and prepares to suck the recording medium 206 onto the media stage 208.

  Next, in step S1062, the conveyance motor 205 is driven to start conveyance of the recording medium 206. In step S1063, the leading end of the recording medium 206 is detected, and in step S1064, recording start signals 914 and 915 are sent to the recording apparatuses. A pulse 913 is transmitted. As described above, the recording start signal is output in relation to the distance from the medium detection sensor 911 to each recording apparatus. When the recording operation of the recording device 116 ends in step S1042, the process proceeds to step S1043, a recording end status is transmitted to the information processing device 100, and the process ends. At this time, each recording head 801 is capped by a capping mechanism to prevent the nozzles (ejection ports) from drying and clogging.

  When the recording is completed and the recording medium 206 is ejected from the media stage 208, the process proceeds from step S1065 to step S1066, and the medium transport apparatus 117 transmits a transport end status to the information processing apparatus 100. Next, in step S1067, the suction motor 908 is stopped, and in step 1068, the transport motor 205 is stopped to end the operation.

(Signal system to complex printer system)
FIG. 6 is a block diagram showing the flow of signals in the recording unit 200. There are roughly two signal systems connected to each of the recording devices 116-1 to 116-5. One is related to transmission of divided recording data (including operation start and end commands) supplied from the information processing apparatus 100, and the other is a recording timing definition signal (recording start signal) supplied from the medium transport apparatus 117. And position pulse). The former includes a hub 140 that relays between the information processing apparatus 100 and the recording apparatuses 116-1 to 116-5. The hub 140 is connected to the information processing apparatus 100 via, for example, a 100BASE-T standard connector / cable 142, and to each of the recording apparatuses 116-1 to 116-5, for example, a 10BASE-T standard connector. / Connected via cable 144.

  In the example of FIG. 6, the transmission system of the recording timing regulation signal includes a transfer control circuit 150 and a synchronization circuit 160, which may be provided as a circuit unit constituting the logic circuit 912 in FIG. The transfer control circuit 150 supplies the output ENCODER of the rotary encoder 910 provided on the shaft of the transport motor 205 and the detection output TOF of the leading end of the recording medium by the medium detection sensor 911 to the synchronization circuit 160.

  The synchronization circuit 160 is provided with a recording operation permission circuit 166, and the logical product of the operation preparation completion signals PU1-RDY to PU5-RDY from the recording devices 116-1 to 116-5 in response to the completion of reception of the divided image data. I take the. As a result, the signal PRN-START for permitting the recording operation is output when the operation preparation of all the recording apparatuses is completed (capping state is released, etc.). Further, the synchronization circuit 160 is provided with a display unit 167 such as an LED for performing display related to the operation preparation completion signals PU1-RDY to PU5-RDY so that the user can visually confirm the operation preparation completion of the recording apparatus. It has become. Further, the synchronization circuit 160 includes a reset circuit unit 168 for forcibly resetting the recording apparatus manually by a user and a pause circuit unit 169 for temporarily stopping the recording after one recording medium has been recorded. It has been added. Further, the synchronization circuit 160 generates position pulses 913 (for example, 300 pulse signals per 1 inch of the conveyance amount of the recording medium) from the encoder output ENCODER as a synchronization signal (Hsync) for performing recording operations in synchronization with each recording apparatus. And a synchronizing signal generation circuit unit 162. Furthermore, the synchronization circuit 160 includes a delay circuit 164 that generates recording instruction signals 914 and 915 that are delay signals corresponding to the positions of the recording apparatuses in the medium conveyance direction from the recording medium leading edge detection output TOF.

  The recording operation of the recording devices 116-1, 116-3, and 116-5 on the upstream side in the recording medium conveyance direction is a delay signal that is delayed by the distance from the medium detection sensor 911 to the position where these recording devices are disposed. The process starts when the recording instruction signal (TOF-IN1) 914 is received. If the distance from the medium detection sensor 911 to the position where these recording devices are disposed is 0, the recording instruction signal 914 is supplied almost simultaneously with the detection output TOF.

  On the other hand, the recording operation of the recording devices 116-2 and 116-4 arranged on the further downstream side is a recording instruction signal which is a delay signal delayed by the distance from the medium detection sensor 911 to the location of the recording devices. (TOF-IN2) Start with reception of 915. In the present embodiment, the distance from the medium detection sensor 911 to the arrangement position of these recording devices is set to 450 mm. Therefore, if the position pulse 913 as the synchronization signal (Hsync) is 300 pulses per 1 inch (25.4 mm) of the conveyance amount of the recording medium, the recording instruction signal 915 is supplied with a delay of 5315 pulses from the detection output TOF.

  As described above, in order to individually correct the minute recording position of each recording apparatus in the medium conveyance direction, or in consideration of the case where the recording apparatuses are not aligned in two rows, each recording apparatus is independent. Then, a recording instruction signal may be supplied.

  As is apparent from FIG. 6, each of the recording apparatuses 116-1 to 116-5 receives the divided recording data from the information processing apparatus 100 and responds to the recording timing regulation signal supplied from the medium transport apparatus 117. The recording operation is performed independently. That is, each of the recording devices 116-1 to 116-5 is a recording unit that is complete with respect to the signal system, and the supply and recording timing of the recording data are transmitted to the other recording devices via one recording device. It is not such a configuration. The recording devices 116-1 to 116-5 align the data corresponding to the recording heads 811 </ b> Y to 811 </ b> K used by themselves and the nozzles arranged in each recording head, and perform an ink ejection operation at a specified timing. Are individually provided. That is, the recording apparatuses 116-1 to 116-5 have the same hardware and operate with the same software, and the operation of one recording apparatus directly affects the operation of the other recording apparatus. Nonetheless, they work together to record one piece of image data as a whole.

(Outline of two-component system)
In addition to being able to operate independently, the recording apparatuses 116-1 to 116-5 in the present embodiment are also mutually connected with respect to the two liquid systems of the ink supply system and the foaming liquid supply system for each recording head 811 in each recording apparatus. It has an independent configuration.

  FIG. 7 is a schematic diagram for explaining a configuration of an ink (first liquid) and foaming liquid (second liquid) supply system. Since the recording heads 811Y, 811M, 811C, and 811K of each recording apparatus have the same configuration, only the configuration of C (cyan ink) of the recording apparatus 116-1 will be described below as a representative. Ink is distributed and supplied to the recording head 811C in the recording apparatus 116-1 from an ink tank 2203C which is an ink supply source through a dedicated tube 2204C. Similarly, the foaming liquid is distributed and supplied from a foaming liquid tank 203C, which is a foaming liquid supply source (second liquid supply source), via a dedicated tube 204C. As a method for supplying the ink and the bubbling liquid, the ink may be continuously supplied in fluid communication with the ink tank, or the ink held in the ink supply unit provided for each recording head is reduced. Ink may be supplied intermittently so as to be in fluid communication at a point in time. Here, the foaming liquid is preferably a liquid having any of the properties of low viscosity, foamability, and thermal stability as compared with the ink.

  The recovery system of the present embodiment includes a cap that is bonded to the ejection port formation surface of the recording head 811 and receives ink that is forcibly discharged from the ejection port. It is configured to circulate in a reusable manner via a communication path). Here, the cap is provided below the conveyance surface of the recording medium 206, that is, inside the media stage 208, so as to face or contact the ejection port forming surface of the recording head. However, in consideration of the use of a continuous paper-like recording medium such as roll paper, it is arranged on the upper side of the recording medium 206 conveyance surface, that is, on the same side as the recording head 811 so that the recovery operation can be performed without removing the recording medium. May be good.

  As described above, in this embodiment, the ink supply system and the recovery system for each recording head 811 in each recording apparatus also have a configuration independent from each other among the recording apparatuses. Accordingly, an appropriate amount of ink can be supplied or recovered in accordance with the operation state of each recording apparatus, that is, the recording amount.

(Configuration example of two-component system)
FIG. 8 is a schematic perspective view showing the arrangement relationship of the main parts of the two liquid systems in the recording apparatus 116, and FIG. 9 is a schematic diagram showing an example of the internal configuration of the two liquid systems for one recording head. The recording head 811 of this embodiment includes a movable separation film, and the ink separation channel (first passage) and the bubbling liquid passage (second passage) are separated by the movable separation film. Further, the movable separation film provided in the recording head 811 of the present embodiment is provided with a concave portion (movable portion), and ink is ejected from the ejection port by displacing the concave portion.

  A foaming liquid connecting tube and an ink connecting tube are connected to the recording head 811. One of the foamed liquid connection pipes (circulation flow path) is connected to a negative pressure chamber 30 for generating a negative pressure such that the concave portion of the movable separation membrane is always convex toward the foam liquid flow path side at a fixed position. The other is connected to a foam liquid supply unit (hereinafter also referred to as a foam liquid sub tank) 40 for each recording head via a pump 48 (pressure control means). In addition, the ink connection pipe is connected to an ink supply unit 940 for each recording head, one through a pump 948 and the other through a valve 936.

  10A to 10F are cross-sectional views showing the state of ink ejection in the recording head of this embodiment over time. The ink flow path 3 (in the first flow path) communicating with the ejection port 1 is filled with ink supplied from the ink common liquid chamber 143. In addition, the foaming liquid flow path 4 (in the second flow path) having the bubble generation region 7 is filled with a foaming liquid that is heated and foamed by being given thermal energy from the heating element 2. A concave portion 8 is provided in a portion of the movable separation film 5 facing the bubble generation region 7, and a corner portion 8 a is provided at a fulcrum of the concave portion 8, thereby forming a concave portion with respect to the ink flow path 3. In addition, the movable separation membrane 5 and the orifice plate 9 are closely fixed to each other, and the liquids in the respective liquid flow paths are not mixed here. Note that, in the foaming liquid flow path 4, the vicinity of the projection area of the heating element 2 is the bubble generation area 7. When the foaming liquid is foamed, the film of the concave portion of the movable separation film 5 is pushed up, and the ink in the ink flow path 3 is ejected from the ejection port and adheres to the recording medium by the action.

  FIG. 11 is an enlarged view showing a nozzle part of the recording head 811 partially in cross section. A plurality of heating elements 2 are provided side by side on the element substrate 10, and a plurality of foam liquid passages 4 (see FIG. 10) are provided on the element substrate 10 corresponding to each heating element 2. Further, the support member 11 that supports the movable separation membrane 5 also serves as a wall that defines and forms each foamed liquid flow path 4. A plurality of recesses 8 are formed in the movable separation film 5 so as to face the bubble generation region 7 in the vicinity of the projection region of each heating element 2. A plurality of ink flow paths 3 are arranged so as to include the respective recesses 8. However, in FIG. 11, the positions where the walls 28 defining the respective first liquid flow paths 3 are placed are indicated by dotted lines.

  FIGS. 12A to 12C are schematic views respectively showing the inside of the negative pressure chamber 30 (see FIG. 9) in which the amount of the foaming liquid is different. A mechanical foaming liquid pump (hereinafter also referred to as “mechanical pump”) 36 is connected to the negative pressure chamber 30 via a pressure adjusting valve 35 (see FIG. 9), and the foaming liquid supply to the negative pressure chamber 30 is performed. Is controlling. The mechanical pump 36 can control the pressure in the negative pressure chamber 30. The pressure adjustment valve 35 can adjust the flow resistance of the foaming liquid in the flow path. The foaming liquid pump 36 in this embodiment is a gear pump. FIG. 12A shows a case where the supply amount of the foaming liquid by the foaming liquid pump 36 is large, and FIG. 12C shows a case where the supply amount is small. The amount of the foaming liquid has a predetermined relationship with the pressure in the negative pressure chamber 30, and the pressure in the negative pressure chamber 30 can be indirectly detected by detecting the amount of the foaming liquid. Therefore, the negative pressure chamber 30 is provided with an optical sensor 149 (light receiving element 149C, light emitting element 149B), and a reflection plate 149A is attached to the plate-like foamed liquid holding portion 33. The light from the light emitting element 149B is reflected by the reflecting plate 149A and then received by the light receiving element 149C, and the amount of received light increases when the amount of foaming liquid in the negative pressure chamber 30 is large as shown in FIG. As shown in FIGS. 12B and 12C, it decreases as the amount of foaming liquid decreases. Therefore, the sensor 149 detects the amount of foaming liquid in the negative pressure chamber 30, and indirectly determines the pressure in the negative pressure chamber 30 from the relationship between the amount of foaming liquid and the negative pressure in the negative pressure chamber 30. Detection is possible without pressure loss.

  Further, as a method of detecting the pressure in the negative pressure chamber 30, the pressure may be directly detected by a pressure sensor. In that case, it is possible to detect the pressure by directly attaching to the plate-like foamed liquid holding part 33 like the pressure sensor 49. As described above, various detection methods can be used to detect the pressure in the negative pressure chamber 30.

  Similarly, a pressure sensor 949 (see FIG. 9) for detecting the pressure in the ink flow path uses a detection system that directly detects the negative pressure in the ink flow path, and various detection systems. be able to. The pressure in the foam liquid passage is controlled by controlling the pump (negative pressure applying means) based on the pressure detection result by the pressure detecting means.

  Here, the valve disposed in each part of the foaming liquid and ink supply path including the valve 35 is of any form as long as the flow path can be appropriately opened and closed or the flow rate can be appropriately controlled according to the control signal. May be used.

  FIG. 13 is a schematic diagram for explaining the valves provided in the foaming liquid and ink flow paths in the present embodiment. The valve 58 includes a ball-shaped valve body 56 inserted on the liquid flow path and a sheet body 57 that receives the valve body 56, and the valve body 56 is connected to a plunger 55 that is advanced and retracted by a solenoid. In this case, the liquid flow path can be opened and closed by controlling energization to the solenoid and receiving / removing the valve body 56 from the seat body 57. FIG. 13A shows an open state of the liquid channel, and FIG. 13B shows a closed state of the liquid channel. However, with respect to the valve 35, in order to enable high-performance negative pressure control with high responsiveness, an element having a light weight such as a piezo element may be used as an actuator.

  In addition, as a pump disposed in each part of the foaming liquid and ink supply path, including the pump 36, any form may be used as long as the liquid can be transferred according to the drive signal. However, in particular, the pump 36 can switch the flow direction of the foaming liquid and can adjust the flow rate of the foaming liquid in this embodiment. In the example shown in FIG. 9, the direction in which the foaming liquid is supplied to the negative pressure chamber 30 (hereinafter, rotation in this direction is referred to as normal rotation) and the direction in which the foaming liquid is extracted from the negative pressure chamber 30 (hereinafter, this will be described). A gear pump capable of selectively transferring ink is shown. The pump 36 is connected to a foam sub-tank 40 that contains an appropriate amount of foam to enable the system to circulate.

  The foaming liquid sub-tank 40 defines a part of the foaming liquid storage space and can be deformed according to the amount of foaming liquid to be stored, and the foaming liquid tube 204 connected to the foaming liquid main tank 203 (see FIG. 7). And a joint 42 for appropriately communicating with the foaming liquid.

  FIGS. 14A and 14B are vertical side views showing a 42 configuration example of a joint for connecting a tube connected to a main tank and a recording head. The joint 42 is connected to a joint 43 provided in the foaming liquid tube 204 when the foaming liquid in the foaming liquid subtank is reduced, so that ink is appropriately supplied from the foaming liquid main tank 203 to the foaming liquid subtank 40. It can be refilled. Valve rubbers 66 </ b> A and 66 </ b> B each having a communication hole are provided at the opposing portions of the joints 42 and 43. When the joints 42 and 43 are not connected, the valve balls 63A and 64A biased by the valve springs 65A and 65B close the openings of the communication holes in the valve rubbers 66A and 66B as shown in FIG. ing. Thereby, both the foaming liquid flow paths connected to each of the joints 42 and 43 are blocked from the outside air.

  When connecting the joints 42 and 43, as shown in FIG. 14 (b), the valve rubbers 66A and 66B are brought into close contact with each other and the valve ball 63A is pushed by the ball lever 67 provided on the valve ball 63B. . As a result, the valve balls 63A and 64A are separated from the valve rubbers 66A and 66B, and the foam liquid passages connected to the joints 42 and 43 are connected to each other.

  The joints 42 and 43 may have any structure as long as the opening can be blocked when disconnected to prevent leakage of the foaming liquid, and the foaming liquid flow path can be connected with the outside air blocked. Good. In addition to switching the fluid communication by appropriately connecting and disconnecting the joints as described above, the supply path itself is always connected, and the fluid communication is switched on and off by an open / close valve. It may be. Further, the configuration of the ink sub tank 940 is the same as described above, and the ink supply between the recording devices does not interfere with each other when the required amount of ink between the recording devices differs according to the content of the divided image data. If it is.

  FIGS. 15A and 15B are schematic configuration diagrams of the ink tank 2203 (2203Y, 2203M, 2203C, and 2203K). The ink tank 2203 of this embodiment includes a flexible ink bag 69 that stores ink, and a tank housing 68 that stores the flexible ink bag 69. An air communication hole 71 is formed in the tank housing 68, and a storage element 70 is attached to the tank housing 68. Various information related to the ink tank 2203 can be stored in the storage element 70. For example, it is possible to write information such as the type of ink to be stored, the remaining amount of ink, the type of ink tank, and the like, and read and use it as necessary. The ink bag 69 is deformed as shown in FIGS. 15A and 15B according to the consumption of the ink accommodated therein. Therefore, the ink in the ink bag 69 can be supplied while being blocked from the outside air. The configuration of the foam liquid tank 203 is the same as that of the ink tank 2203.

  The other end of the connecting pipe (communication flow path) of the foaming liquid connected to the recording head 811 is connected to the foaming liquid sub tank 40 via the pump 48 as shown in FIG. By operating the pump 48 and the pump 36, the foaming liquid can be circulated among the foaming liquid subtank 40, the negative pressure chamber 30 and the recording head 811.

  Similarly, the other of the ink connection pipes connected to the recording head 811 is connected to the ink sub-tank 940 via a valve 948. By the operation of the pump 948, the ink can be circulated between the ink sub tank 940 and the recording head 811.

  The recording apparatus 116 also includes a recovery system mechanism for maintaining or recovering the ink ejection performance of the recording head 811 in a healthy state, and a cap 44 (see FIG. 9) that seals the recording head 811 as a part thereof. I have. During the recovery operation, the valve 936 operates with the valve 936 closed. Then, the inside of the recording head 811 is rapidly pressurized, and a relatively large amount of ink is forcibly discharged from each nozzle of the recording head 811 in a short time. By this forced discharge, foreign matter, thickened ink, etc. in the nozzle are discharged, and the discharge state of each nozzle is restored to a good state. The forcibly discharged ink is discharged into the ink reservoir in the cap 44, but is quickly collected and reused in the ink sub tank 940 via the valve 947 by the action of the pump 945 that is operating in advance. At that time, the discharged foreign matter is removed by a filter (not shown) or the like, and the thickened ink is diluted in the ink sub-tank 940 to have a normal ink viscosity.

  Thereafter, the recording device 116 performs a wiping operation of the nozzle row of the recording head 811 by a wiper blade (not shown) and a preliminary discharging operation for discharging ink that does not contribute to image recording, and the recovery operation of the recording head 811 is completed. To do.

  The recording apparatus 116 or the recording head 811 according to this embodiment includes such a supply system, so that the recording apparatus 116 or the recording head 811 is separated from the image forming system and the image forming apparatus and independent of other recording apparatuses under various conditions. Can be controlled independently, and can be installed and replaced independently.

(Characteristic configuration)
(Operation of foaming liquid system)
Hereinafter, the operation of the foaming liquid system according to the usage status of the recording apparatus 116 will be described.

During recording standby (see FIGS. 10 and 16)
FIG. 16 is a schematic diagram showing the internal configuration of the two-liquid system for the recording head. In a normal standby state such as before the start of recording, as shown in FIG. 10 (a), the slack of the concave portion 8 of the movable separation membrane 5 becomes convex toward the foaming liquid flow path 4, and stability is maintained at a fixed position. In order to maintain the pressure, a negative pressure is applied to the foaming liquid in the recording head 811. That is, as shown in FIG. 16, the pump 48 is stopped, the return of the foaming liquid from the recording head 811 to the foaming liquid subtank 40 via the flow path (second communication path) is restricted, and the pump 36 is reversed. The foaming liquid in the negative pressure chamber 30 is returned to the foaming liquid sub tank 40. As a result, the negative pressure acting on the foaming liquid in the recording head 811 increases. Then, as shown in FIG. 10A, the slack of the concave portion 8 of the movable separation membrane 5 maintains a negative pressure state that is stable at a certain position on the foam liquid passage 4 side, and waits for the start of recording. The volume of the foam liquid sub tank 40 increases by the amount of the foam liquid returned from the negative pressure chamber 30.

Control during recording (see FIGS. 10 and 17)
FIG. 17 is a schematic diagram showing the internal configuration of the two-liquid system for the recording head. By appropriately controlling the negative pressure adjusting valve 35 and the mechanical pump 36, the sag of the concave portion 8 of the movable separation membrane 5 during non-foaming can be maintained more stably. In general, as shown in FIG. 10D, the movable separation membrane 5 is displaced to the ink flow path side 3 by foaming, and as shown in FIG. Try to displace to 4. However, at that time, as the ink flow side is refilled (= return of the meniscus), a negative pressure is generated on the ink flow path side, so that the sag of the concave portion 8 of the movable separation film 5 surely returns to the original state. Not necessarily. Therefore, the pump 48 is stopped to restrict the return of the foaming liquid from the recording head 811 to the foaming liquid subtank 40, and the pump 36 is reversed to return the foaming liquid in the negative pressure chamber 30 to the foaming liquid subtank 40. As a result, the negative pressure acting on the foaming liquid in the recording head 811 is increased, and the sag of the concave portion 8 of the movable separation film 5 is stabilized at a fixed position on the foaming liquid flow path 4 side as shown in FIG. Let

  Further, according to various recording duties (recording densities) corresponding to the contents of the image data recorded by the recording device 116 or the recording head 811, the sagging of the concave portion 8 of the movable separation film 5 when not foamed is more stably maintained. can do. For example, when the recording duty is low, the negative pressure applied to the ink side is small, so the pump 36 is reversed at a low speed to return the foaming liquid in the negative pressure chamber 30 to the foaming liquid subtank 40. Further, in order to optimize the sagging of the concave portion 8 of the movable separation membrane 5 during non-foaming, the negative pressure adjusting valve 35 is controlled immediately after recording to stabilize the negative pressure applied to the foaming liquid side with high accuracy. In that case, the rate at which the flow path is opened is relatively small, and the opening degree is controlled in a relatively small range.

  Further, when the recording duty (recording density) is high, the negative pressure applied to the ink side increases, so the pump 36 is reversed at a higher speed to return the foaming liquid in the negative pressure chamber 30 into the foaming liquid subtank 40. The negative pressure adjustment valve 35 is controlled to stabilize the negative pressure. In that case, the rate at which the flow path is opened is relatively large, and the opening degree is controlled in a relatively large range.

  The negative pressure adjusting valve 35 can be controlled by feeding back the output signals of the negative pressure chamber 30, that is, the sensor 49 for detecting the negative pressure on the foaming liquid side and the sensor 949 for detecting the negative pressure on the ink side. Further, as will be described later, the negative pressure adjusting valve 35 and the pump 36 can be controlled in advance based on the recorded data.

Control during recovery operation (maintenance) (see FIGS. 10 and 18)
FIG. 18 is an explanatory diagram of a recovery operation for forcibly discharging ink that does not contribute to image recording from the ejection openings of the recording head 811. In this recovery operation, the pump 948 is operated with the valve 936 closed. Then, the ink flow path side of the recording head 811 is suddenly pressurized, and a relatively large amount of ink is forcibly discharged from each nozzle of the recording head 811 in a short time. At this moment, each nozzle is restored to a healthy state. The forcibly discharged ink is discharged into the ink reservoir in the cap 44, but is quickly collected and reused in the ink sub tank 940 via the valve 947 by the action of the pump 945 that is operating in advance. Thereafter, the wiping of the nozzle row of the recording head 811 by a wiper blade (not shown) and a preliminary ejection operation are performed, and the recovery operation of the recording head 811 is completed.

  During this time, since the ink flow path side is pressurized, the concave portion 8 of the movable separation membrane 5 sags toward the foam liquid flow path 4 side (a state protruding to the foam liquid flow path side). However, at this time, in order to relieve excessive pressure applied to the movable separation membrane 5, the pump 36 is rotated forward to apply positive pressure to the foam liquid passage side, and the negative pressure adjustment valve 35 is controlled in order to further optimize. To stabilize the pressure with high accuracy. At this time, the pressure is controlled within a range in which the slack of the concave portion 8 of the movable separation membrane 5 is stably maintained at the same position as in FIG. By doing so, it is possible to prevent excessive pressure from being applied to the movable separation membrane 5 and extend the life of the movable separation membrane 5. After the recovery operation, control is performed so as to maintain a negative pressure state in which the sag of the concave portion 8 of the movable separation membrane 5 is stabilized at a fixed position on the foam liquid passage 4 side, as in the standby mode.

  As described above, the negative pressure of the foaming liquid supplied to the recording head is positively controlled, and an appropriate negative pressure is stably applied to the foaming liquid side, so that the concave portion 8 of the movable separation film 5 at the time of non-foaming is obtained. It becomes possible to maintain the sagging of the water more stably. As a result, it was possible to realize a recording apparatus capable of stably discharging ink with a constant discharge amount during discharge.

(Second Embodiment)
FIG. 19 is a schematic diagram showing an internal configuration of a two-liquid system for one recording head. A foaming liquid connecting tube and an ink connecting tube are connected to the recording head 811. One of the foamed liquid connection pipes is connected to a negative pressure chamber 30 for generating a negative pressure that is preferable for the movable separation film 5 of the recording head 811 to always form the recess 8 at a fixed position on the foamed liquid flow path 4 side. Yes. The other end of the foaming liquid connection pipe is connected to a foaming liquid supply unit (hereinafter also referred to as a foaming liquid subtank) 40 for each recording head via a pump 48. Similarly, one of the ink connecting pipes is connected to a negative pressure chamber 1930 for generating a preferable negative pressure that balances with the holding force of the ink meniscus formed at the ink discharge port 1 of the recording head 811. The other of the ink connection pipes is connected to an ink supply unit (hereinafter also referred to as an ink sub tank) 940 for each recording head 811 via a pump 948.

  As the pressure sensor 49, various detection methods can be used in addition to a detection method that directly detects the negative pressure in the negative pressure chamber 30. Similarly, as the pressure sensor 949, various detection methods can be used in addition to a detection method that directly detects the negative pressure in the negative pressure chamber 1930.

  A mechanical foaming liquid pump 36 is connected to the negative pressure chamber 30 via a pressure adjustment valve 35, and the foaming liquid supply to the negative pressure chamber 30 is controlled. The foaming liquid pump 36 in this embodiment is a gear pump. The pump 36 is connected to a foaming liquid sub tank 40 that stores an appropriate amount of foaming liquid circulating in the system.

  A mechanical ink pump 1936 is connected to the negative pressure chamber 1930 via a pressure adjustment valve 1935 to control ink supply to the negative pressure chamber 1930. The ink pump 1936 in this embodiment is a gear pump. The pump 1936 is connected to an ink sub-tank 940 that stores an appropriate amount of ink circulating in the system.

  The configuration of the ink sub-tank 940 is the same as described above, and the ink supply between the recording devices does not interfere with each other when the required amount of ink between the recording devices differs according to the content of the divided image data. I just need it.

  The other connecting pipe of the recording head 811 is connected to the foaming liquid subtank 40 via the pump 48, and the operation of the pump 48 and the pump 36 causes the foaming liquid subtank 40, the negative pressure chamber 30, and the recording head 811 to be connected. The foaming liquid can be circulated. Similarly, the ink subtank 940 is connected via a pump 948, and the ink can be circulated between the ink subtank 940 and the recording head 811 by the operation of the pump 948. Further, the recording apparatus 116 includes a recovery system mechanism for maintaining or recovering the ink ejection performance of the recording head 811 in a healthy state, and includes a cap 44 that hermetically seals the recording head 811 as a part thereof.

  The recording apparatus 116 or the recording head 811 according to this embodiment includes such a supply system, so that the negative pressure on the ink flow path side is controlled in the negative pressure chamber 1930 to stabilize the holding force of the ink meniscus. it can. Further, by controlling the negative pressure on the foaming liquid channel side in the negative pressure chamber 30, the concave portion 8 of the movable separation film 5 of the recording head 811 can be formed at a stable position, and more stable discharge is performed. be able to.

  As described above, the negative pressure of the foaming liquid supplied to the recording head is positively controlled, and an appropriate negative pressure is stably applied to the foaming liquid side, so that the concave portion 8 of the movable separation film 5 at the time of non-foaming is obtained. It becomes possible to maintain the sagging of the water more stably. As a result, it was possible to realize a recording apparatus capable of stably discharging ink with a constant discharge amount during discharge.

  In the present invention, the plurality of recording apparatuses employed in the present embodiment are independent of each other. That is, the plurality of printing apparatuses are independent in space (arrangement) in relation to each other, and are also independent in the signal system and the ink system. Therefore, an appropriate amount of ink can be supplied or recovered in accordance with the operation state of each recording apparatus, that is, the recording amount. In addition, the recording apparatus can be controlled under various conditions separately from the image forming system and the image forming apparatus and independently of other recording apparatuses, and the recording apparatus can be handled and handled as a single unit. Become.

1 is a block diagram illustrating an outline of an image forming system using a liquid ejection apparatus according to a first embodiment. 1 is an external perspective view illustrating an outline of an image forming system using a liquid ejection apparatus according to an embodiment. FIG. 3 is a diagram illustrating a configuration example of a control system in the recording apparatus according to the first embodiment. FIG. 3 is a block diagram illustrating a configuration example of a control system of the medium transport apparatus. 6 is a flowchart showing the mutual operation procedure of the information processing apparatus, the recording apparatus, and the medium transport apparatus. It is the block diagram shown so that the flow of the signal in a recording unit could be understood. It is a schematic diagram for demonstrating the structure of an ink and a foaming liquid supply system. FIG. 3 is a schematic perspective view showing the arrangement relationship of main parts of a two-liquid system in the recording apparatus. It is the schematic which showed the internal structural example of the 2 liquid system with respect to one recording head. (A)-(f) is sectional drawing which showed the mode of the ink discharge in the recording head of this embodiment over time. FIG. 4 is an enlarged view illustrating a nozzle portion of a recording head. (A)-(c) is the schematic which each showed the inside of the negative pressure chamber from which the quantity of foaming liquid differs. It is a schematic diagram for demonstrating the valve | bulb provided in the foaming liquid and ink flow path in 1st Embodiment. (A), (b) is a vertical side view which shows the structural example of the joint which connects the tube and recording head which are arranged in a line with the main tank. (A), (b) is a schematic block diagram of an ink tank. It is the schematic which showed the internal structure of the 2 liquid system with respect to a recording head. It is the schematic which showed the internal structure of the 2 liquid system with respect to a recording head. FIG. 10 is an explanatory diagram of a recovery operation for forcibly discharging ink that does not contribute to image recording from the ejection port of the recording head. It is the schematic which showed the internal structure of the 2 liquid system with respect to a recording head.

Explanation of symbols

4 Foaming liquid flow path 5 Movable separation membrane 8 Recess 30 Negative pressure chamber 33 Plate-shaped foaming liquid holding part 35 Negative pressure adjusting valve 36 Pump 40 Foaming liquid subtank 49 Pressure sensor 116 Recording device 811 Recording head 940 Ink subtank 949 Pressure sensor 1930 Negative Pressure chamber 1936 Ink pump

Claims (19)

A first flow path through which the first liquid discharged to the recording medium flows, and a second flow through which the second liquid flows and separated from the first flow path by a separation film having a movable portion. A liquid ejecting apparatus comprising: a recording unit including a path; and a transport unit configured to transport the recording medium.
Pressure control means capable of controlling the pressure in the second flow path;
The liquid ejection apparatus according to claim 1, wherein the pressure in the second flow path is controlled to be lower than the pressure in the first flow path by the pressure control means.   The liquid discharge apparatus according to claim 1, further comprising a heating element at a position facing the separation membrane in the second flow path.   The liquid ejecting apparatus according to claim 2, wherein the heating element heats the second liquid to generate bubbles.   The liquid ejection apparatus according to claim 1, wherein the first liquid and the second liquid are different liquids.   5. The method according to claim 1, wherein the second liquid is superior in at least one of low viscosity, foamability, and thermal stability as compared with the first liquid. A liquid ejection apparatus according to claim 1.   The pressure control unit includes a pressure detection unit, and the pressure control unit controls the pressure in the second flow path by controlling the negative pressure applying unit based on a detection result of the pressure detection unit. The liquid ejection device according to any one of claims 1 to 5.   The liquid ejecting apparatus according to claim 6, wherein the pressure detection unit can detect the pressure in the first flow path and the second flow path without pressure loss.   8. The liquid according to claim 1, wherein the first communication path is a liquid flow path for supplying the first liquid from a liquid supply source to the recording unit. Discharge device.   9. The liquid according to claim 1, wherein the first communication path is a return flow path for returning the first liquid from the recording means to the liquid supply source. Discharge device.   The second communication path is a liquid flow path for supplying the second liquid from a second liquid supply source to the recording means. The liquid discharge apparatus as described.   11. The second communication path is a return path for returning the second liquid from the recording means to the second liquid supply source. Liquid discharge device.   2. The negative pressure applying means includes a pump and a valve provided in the second flow path, and the pressure control means controls the pump and the valve in relation to each other. The liquid ejection apparatus according to claim 11.   The liquid discharge apparatus according to claim 12, wherein the pump is capable of changing a pressurizing direction of the second liquid in the second flow path.   The second channel includes a circulation channel capable of circulating the second liquid, and a communication channel communicating the circulation channel and the recording means, and the pump is provided in the circulation channel. The liquid ejection device according to claim 12 or 13, wherein the valve is provided in at least one of the circulation flow path and the communication flow path.   The liquid ejection device according to claim 14, wherein the valve is provided in the circulation flow path and can adjust a flow resistance of the second liquid.   16. The liquid ejection apparatus according to claim 1, wherein recording is performed by ejecting the first liquid from the recording unit and attaching the first liquid to the recording medium.   The liquid ejection apparatus according to claim 1, wherein a composite printing system is configured by a plurality of liquid ejection apparatuses. A first flow path through which the first liquid discharged to the recording medium flows, and a second flow through which the second liquid flows and separated from the first flow path by a separation film having a movable portion. A liquid ejecting apparatus comprising: a recording unit including a path; and a transport unit configured to transport the recording medium.
Pressure control means capable of controlling the pressure in the first flow path,
Pressure control means capable of controlling the pressure in the second flow path;
The liquid ejection apparatus according to claim 1, wherein the pressure in the second flow path is controlled to be lower than the pressure in the first flow path by the pressure control means.   Pressure detection means, and the pressure control means controls the pressure in the first flow path or the second flow path by controlling the negative pressure applying means based on the detection result of the pressure detection means. The liquid ejection device according to claim 18, wherein the liquid ejection device is a liquid ejection device.

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