JP2013184352A - Pressure adjustment device and inkjet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately execute initialization control of a membrane position even when a pressure sensor is provided in an air chamber.SOLUTION: A pressure adjustment device includes: a first tank 18 which is configured by partitioning a hermetically-sealed container having a predetermined capacity into a first air chamber 26 and a second liquid chamber 24 by a first elastic membrane 22 and in which the first liquid chamber 24 communicates with a liquid ejection head 50 having nozzles and channels; a first liquid feed means 20 which feeds or discharges liquid to or from the first tank 18; a gas pressure detecting means 44 which detects the pressure in the first air chamber 26; and a first position control means which is configured such that a designated supply amount of liquid is supplied to the first liquid chamber 24 by the first liquid feed means 20 so as to allow the first elastic membrane 22 to stick onto a wall surface 26A of the first air chamber 26, and then, a designated discharge amount of liquid is discharged by the first liquid feed means 20 so as to control the position in the first tank 18 of the first elastic membrane 22. Further an inkjet recording apparatus thereof is also provided.

Description

  The present invention relates to a pressure adjusting device and an ink jet recording apparatus, and in particular, a pressure adjusting device including a buffer chamber for buffering a pulsating flow generated by a pump that adjusts a back pressure of a droplet discharge head that discharges droplets. And an ink jet recording apparatus.

  The liquid ejection head is provided with a plurality of nozzles for ejecting liquid, a plurality of pressure chambers respectively communicating with the plurality of nozzles, and a common flow path for supplying ink to the plurality of pressure chambers. Yes. In such a liquid discharge head, when the pressure in the flow path in the liquid discharge head fluctuates, the droplet generation process is affected, and the quality of an image formed on the discharge target medium is affected. Therefore, it is desirable to maintain a constant pressure difference between the pressure in the flow path in the droplet discharge head and the atmospheric pressure.

  Therefore, it has been proposed to provide a buffer tank for reducing the pulsating flow generated by the pump in order to adjust the pressure of the flow path of the liquid discharge head. There are two methods for measuring the pressure in the buffer tank: measuring the pressure of the liquid chamber in the buffer tank and measuring the pressure of the air chamber.

  Patent Document 1 below describes a pressure adjusting device in which a pressure sensor is provided in each of a liquid chamber and a gas chamber in order to adjust the pressure in the buffer tank. Patent Document 2 describes an ink jet recording apparatus in which a pressure sensor is provided only in a liquid chamber.

JP 2008-200903 A JP 2009-101516 A

  From the viewpoint of cost reduction and downsizing of the apparatus, it is desired to use a pressure sensor that detects gas pressure rather than a pressure sensor that detects liquid pressure.

  However, when an elastic material is used for the movable film that separates the air chamber and the liquid chamber in the buffer tank, the pressure in the gas chamber is equal to the sum of the pressure in the liquid chamber and the elastic force of the movable film, so that the movable film is relaxed. In the closed state, the pressure values of the gas chamber and the liquid chamber match, but when the movable film is stretched, the pressure values are different.

  Therefore, when initializing the movable film in the buffer tank or in the film fixing control at the time of pressurization such as pressure purge, it is necessary to fix the movable film on the wall in the buffer tank. Since the accurate pressure of the liquid was not known with this pressure sensor, it could not be controlled normally.

  The present invention has been made in view of such circumstances, and there is provided a pressure adjusting device and an ink jet recording apparatus capable of accurately performing initialization control of a film position even when a pressure sensor of a gas chamber is used. The purpose is to provide.

  In order to achieve the above object, the present invention is configured such that a sealed container having a predetermined volume is partitioned into a first air chamber and a first liquid chamber by a first elastic membrane, A first tank communicating with a droplet discharge head having a nozzle and a flow path, a first liquid feeding means for feeding or discharging a liquid to the first tank, and a first gas First gas pressure detecting means for detecting the pressure of the chamber, and supplying the first elastic film to the first liquid chamber by supplying a specified supply amount of liquid by the first liquid feeding means. First position control for controlling the position of the first elastic membrane in the first tank by discharging the specified discharge amount of liquid by the first liquid feeding means after being attached to the wall surface of the air chamber And a pressure regulating device comprising:

  According to the present invention, the film position initialization control of the elastic film can be performed even when the gas pressure detecting means for detecting the pressure of the air chamber is used. In a container in which an air chamber and a liquid chamber are partitioned by an elastic film, the elastic pressure of the elastic film is influenced in addition to the gas pressure and the liquid pressure. When the gas was supplied, the position of the elastic film in the container could not be accurately grasped only by the gas pressure detection means.

  Therefore, in the present invention, the elastic film can be attached to the wall surface of the air chamber by supplying a specified supply amount of liquid to the liquid chamber. After that, by discharging a specified discharge amount corresponding to the air chamber from the liquid chamber, it is possible to perform control for determining the initial position of the elastic membrane. Therefore, even when the gas pressure detecting means for detecting the pressure in the air chamber is used, the initialization control of the film position can be performed accurately.

  The pressure regulating device according to another aspect of the present invention is configured such that a sealed container having a predetermined volume is partitioned into a second air chamber and a second liquid chamber by a second elastic membrane, The second liquid chamber has a second tank communicating with the droplet discharge head, a second liquid feeding means for feeding or discharging the liquid to the second tank, and the pressure of the second air chamber. Second gas pressure detecting means for detecting, and supplying the second elastic film to the second liquid chamber by supplying a specified supply amount of liquid by the second liquid feeding means to the second liquid chamber. And a second position control means for controlling the position of the elastic membrane in the second tank by discharging a specified discharge amount of liquid by the second liquid feeding means after being attached to the wall surface. preferable.

  According to the pressure adjustment device of another aspect of the present invention, the circulation type liquid having the first tank on the supply side to the droplet discharge head and the second tank on the discharge side from the droplet discharge head Even in the supply device, the initialization control of the film position can be performed accurately.

  In the pressure adjusting device according to another aspect of the present invention, the designated supply amount is equal to or greater than a total volume of the volume of the first air chamber and the volume of the first liquid chamber, or the volume of the second air chamber and the second volume. It is preferable to supply a liquid amount equal to or greater than the total volume of the liquid chambers.

  According to the pressure adjusting device according to another aspect of the present invention, the liquid is supplied as the designated supply amount not less than the total volume of the volume of the air chamber and the volume of the liquid chamber, that is, the volume of the tank. The inside can be made into a liquid chamber by the pressure of ink, and the elastic film can be securely attached to the wall surface of the air chamber. In addition, since the liquid exceeding the capacity of the tank is fed, the elastic film can be attached to the wall of the air chamber regardless of the position.

In order to achieve the above object, the present invention is configured such that a sealed container having a predetermined volume is partitioned into a first air chamber and a first liquid chamber by a first elastic membrane, A first tank communicating with a droplet discharge head having a nozzle and a flow path, a first liquid feeding means for feeding or discharging a liquid to the first tank, and a first gas First gas pressure detecting means for detecting the pressure of the chamber, and the pressure of the first air chamber corresponding to the pressure of the first liquid chamber where the first elastic film sticks to the wall surface of the first air chamber Is set to Pair ₁ , the recording means for recording the _first air chamber pressure Pair ₁ , and the first liquid chamber, the pressure of the first gas pressure detecting means by the first liquid feeding means to Pair ₁ . In the first tank of the first elastic membrane, after the liquid is fed until it reaches the end, the first liquid feeding means discharges the specified discharge amount of the liquid. A first position control means for controlling the position, to provide a pressure regulating device comprising a.

According to the present invention, by monitoring the pressure of the liquid chamber and the pressure of the air chamber in advance, it is confirmed from the pressure of the liquid chamber that the elastic film has stuck to the wall surface of the air chamber. The air chamber pressure corresponding to is recorded as Pair ₁ in the recording means. Then, while monitoring the gas pressure detecting means, the gas pressure detecting means is feeding the liquid to a Pair _1, when the gas pressure detecting means becomes a Pair _1, pasting elastic film on the wall surface of the air chamber be able to. Therefore, after that, by discharging a specified discharge amount corresponding to the air chamber from the liquid chamber, it is possible to perform control for determining the initial position of the elastic membrane.

The pressure regulating device according to another aspect of the present invention is configured such that a sealed container having a predetermined volume is partitioned into a second air chamber and a second liquid chamber by a second elastic membrane, The second liquid chamber has a second tank communicating with the droplet discharge head, a second liquid feeding means for feeding or discharging the liquid to the second tank, and the pressure of the second air chamber. Second gas pressure detecting means for detecting, and the pressure of the second air chamber corresponding to the pressure of the second liquid chamber with which the second elastic film sticks to the liquid surface of the second air chamber is Pair _2. When the liquid is supplied to the recording means for recording Pair ₂ and the second liquid chamber until the pressure of the second gas pressure detecting means becomes Pair ₂ by the second liquid feeding means, Second position control means for controlling the position of the second elastic membrane in the second tank by discharging a specified discharge amount of liquid by the two liquid feeding means; Preferably comprises a.

  According to the pressure adjustment device of another aspect of the present invention, the circulation type liquid having the first tank on the supply side to the droplet discharge head and the second tank on the discharge side from the droplet discharge head Even in the supply device, the initialization control of the film position can be performed accurately.

  In the pressure adjusting device according to another aspect of the present invention, the designated drainage amount is preferably an amount at which the elastic force of the elastic membrane is not generated.

  According to the pressure adjusting device according to another aspect of the present invention, since the designated drainage amount is set to an amount at which the elastic force of the elastic membrane is not generated, the initial position of the elastic membrane can be set to a position at which no elastic force is generated. .

  In the pressure adjusting device according to another aspect of the present invention, the designated drainage amount is preferably equal to the capacity of the air chamber.

  According to the pressure adjustment device according to another aspect of the present invention, the initial position of the elastic membrane can be controlled to a desired position by making the designated drainage amount equal to the capacity of the air chamber.

  The pressure regulator according to another aspect of the present invention preferably includes a relief valve in the supply flow path to the tank.

  According to the pressure adjusting device according to another aspect of the present invention, since the relief valve is provided in the supply flow path, even if the liquid is supplied after the film is stuck, it can be opened at a pressure higher than a certain level. Since it can do, it can prevent that the pressure in a tank and a supply flow path becomes high.

  In the pressure regulating device according to another aspect of the present invention, the first air chamber switches the first air communication path communicating with the atmosphere, and the first air chamber is switched between the opening of the first air chamber and the blocking of the atmosphere. An air communication path switching means, wherein the second air chamber is a second air communication path that communicates with the atmosphere, and a second air communication path that switches between opening the second air chamber to the atmosphere or blocking the atmosphere. Switching means, and after the first elastic membrane is attached to the wall of the first air chamber, the first atmosphere communication path switching is performed so as to block the first atmosphere communication path switching means from the atmosphere. After the first elastic film fixing control means for controlling the means and the second elastic film are attached to the wall surface of the first air chamber, the second atmosphere communication path switching means is switched to be cut off from the atmosphere. It is preferable to include second elastic film fixing control means for controlling the second atmosphere communication path switching means.

  According to the pressure adjusting device according to another aspect of the present invention, the first air chamber is blocked from communicating with the atmosphere in a state where the first elastic film is attached to the wall surface of the first air chamber. The membrane fixing control can be performed in which the first elastic membrane is fixed in a state where the first elastic membrane is stuck to the wall surface of the first air chamber. Therefore, in a process requiring a high pressure such as a pressure purge, the subsequent process can be performed without receiving pressure buffering of the elastic film in the tank.

  The pressure regulating apparatus according to another aspect of the present invention includes a first gas flow path that communicates with the first air chamber at one end, and a first gas that communicates with the other end of the first gas flow path. One end of the storage section, the first gas flow path switching means for switching communication or blocking between the first air chamber and the first gas storage section, the one end of the first gas storage section, and the other end Comprising a first air communication path that communicates with the atmosphere, and first air communication path switching means that switches between opening the atmosphere of the first gas storage section or blocking the atmosphere. Communicating or blocking the second gas flow path whose end communicates, the second gas storage section communicating with the other end of the second gas flow path, and the second air chamber and the second gas storage section The second gas flow path switching means for switching the second gas storage section, the second gas storage section, one end communicating with the second gas communication section, the other end communicating with the atmosphere, the second atmosphere communication path, A second atmosphere communication path switching means for switching between opening of the body storage section to the atmosphere or blocking of the atmosphere, and the first gas flow path switching section communicated with the first air chamber and the first gas storage section. In a state where the first atmosphere communication path switching means is cut off from the atmosphere, the first liquid feeding means is controlled to attach the first elastic film to the wall of the first air chamber, The first elastic film fixing control means for controlling the first gas flow path switching means for switching so that the air chamber and the first gas storage section are shut off, and the second gas flow path switching means are the second In a state where the air chamber communicates with the second gas reservoir, and in a state where the second atmosphere communication path switching means is cut off from the atmosphere, the second liquid feeding means is controlled, and the second elastic film is moved to the second gas A second gas flow path switching means for controlling the second gas flow path switching means for switching so that the second air chamber and the second gas storage section are blocked after being attached to the wall surface of the chamber; An elastic membrane fixed control means preferably comprises a.

  According to the pressure regulating device according to another aspect of the present invention, since the gas storage section has the gas storage section and the gas in the air chamber can escape to the gas storage section, even if the air chamber and the atmosphere are not in communication, An elastic membrane can be attached to the wall of the air chamber. Further, since the pressure of the gas pressure detecting means can be increased to atmospheric pressure or higher, the pressure in the tank can be controlled by the gas pressure detecting means by storing the pressure of the air chamber corresponding to the pressure of the liquid chamber in advance. It can be confirmed that the elastic film has stuck to the air chamber. In addition, after the elastic film sticks to the air chamber, the communication between the air chamber and the gas storage unit is blocked, whereby the film can be fixed.

  In order to achieve the above object, the present invention provides an ink jet recording apparatus provided with the pressure adjusting device described above.

  According to the present invention, since the pressure adjusting device described above can adjust the pressure of the supplied liquid, the ink can be stably supplied by being used in the ink jet recording apparatus.

  According to the pressure adjusting device of the present invention, since the pressure sensor of the air chamber is used without providing the pressure sensor in the liquid chamber, the size and cost of the device can be reduced. Even when a pressure sensor in the air chamber is used, the membrane position initialization control and the membrane fixing control can be normally performed.

It is a block diagram which shows schematic structure of a non-circulation type ink supply apparatus. It is a block diagram which shows the structure of the pressure regulator applied to the ink supply apparatus shown in FIG. It is sectional drawing which shows the structure of the subtank applied to the pressure regulator shown in FIG. It is a block diagram which shows the structure of the control part applied to the ink supply apparatus shown in FIG. It is a block diagram which shows the structural example which applied the ink supply apparatus shown in FIG. 1 as an ink supply apparatus of an inkjet head. It is a flowchart figure which shows the flow of the film | membrane position initialization control of the elastic film which concerns on 1st Embodiment. It is a flowchart figure which shows the flow of the film | membrane position initialization control of the elastic film which concerns on 2nd Embodiment. It is a graph which shows the relationship between the pressure of a liquid chamber and an air chamber with respect to an ink supply amount. It is a figure explaining the deformation | transformation state of the elastic film in the graph shown in FIG. It is a block diagram which shows schematic structure of a circulation type ink supply apparatus. It is a block diagram which shows the structure of other embodiment of a pressure regulator. It is a flowchart figure which shows the flow of the film | membrane fixing control which concerns on 3rd Embodiment. It is a flowchart figure which shows the flow of the film | membrane fixation control which concerns on 4th Embodiment. It is a flowchart figure which shows the flow of control of pressurization purge. It is a flowchart figure which shows the flow of the pressure storage process of the non-circulation type ink supply apparatus shown in FIG. It is a flowchart figure which shows the flow of the ink discharge process of the non-circulation type ink supply apparatus shown in FIG. It is a flowchart figure which shows the flow of the pressure storage process of the circulation type ink supply apparatus shown in FIG. It is a flowchart figure which shows the flow of the ink discharge process of the circulation type ink supply apparatus shown in FIG. 1 is an overall configuration diagram showing a schematic configuration of an ink jet recording apparatus to which a pressure adjusting device according to the present invention is applied. FIG. 20 is a perspective plan view illustrating a configuration example of an inkjet head mounted on the inkjet recording apparatus illustrated in FIG. 19. It is a top view explaining nozzle arrangement of the ink jet head shown in FIG. It is sectional drawing which shows the three-dimensional structure of the inkjet head shown in FIG.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the following, an ink supply device will be described as an example of a device including a pressure adjustment device, but the present invention is not limited to this.

(Overall configuration of non-circulating ink supply device)
FIG. 1 is a block diagram showing the overall configuration of a non-circulating ink supply apparatus. The ink supply apparatus 10 shown in FIG. 1 may be described as an inkjet head (hereinafter simply referred to as “head”) that is a liquid supply target. This is a non-circular ink supply device that supplies ink from the ink tank 52 to the ink 50 and controls the internal pressure (back pressure) of the head 50 by the amount of ink fed.

  As shown in FIG. 1, the ink supply device 10 includes a supply channel 12 that communicates with the head 50, a supply valve 14 that switches between communication and non-communication between the head 50 and the supply channel 12, and the interior of the supply channel 12. A supply sub-tank 18 that is a pressure adjusting device that performs pressure adjustment so as to suppress fluctuations in pressure is connected to the opposite side of the head 50 of the supply sub-tank 18 (a supply flow path between the supply sub-tank 18 and the ink tank 52). And supply pump 20 (connected to 12).

  The supply valve 14 is a normally closed (or latched) electromagnetic valve whose opening / closing is controlled by a control signal. When the supply valve 14 is opened and the supply pump 20 is rotated forward, ink flows from the ink tank 52 into the supply flow path 12, passes through the supply sub tank 18, and is sent to the head 50.

  FIG. 2 is a block diagram showing the configuration of the pressure adjusting device in the ink supply device 10 shown in FIG. The pressure adjusting device shown in FIG. 2 includes a supply sub tank 18, and the supply sub tank 18 has a structure partitioned into a liquid chamber 24 and an air chamber 26 by a flexible elastic film 22. The ink outlet 24 A of the liquid chamber 24 communicates with the head 50 via the supply flow path 12 and the supply valve 14, and the ink inlet 24 B communicates with the ink tank 52 via the relief valve 42 and the supply pump 20. (See FIG. 1). The relief valve 42 is in communication with the ink tank 52 via the pressure release channel 43. By providing the relief valve 42 and the pressure release channel 43, when the pressure in the supply sub-tank 18 and the supply channel 12 becomes high, the ink is returned to the ink tank 52 via the pressure release channel 43, The pressure can be released. Further, the liquid chamber 24 communicates with the ink tank 52 via the drain flow path 28 and the drain valve 30 (see FIG. 1).

  When ink flows into the liquid chamber 24 from the ink inflow port 24B, the elastic film 22 is deformed toward the air chamber 26 according to the volume of the ink that has flowed in. On the other hand, since the volume of the ink flowing out from the ink outlet 24A does not fluctuate, even if the pressure fluctuation occurs in the supply flow path 12, the pressure fluctuation is suppressed by the action of the supply sub tank 18.

  That is, the supply sub-tank 18 has a pressure adjustment function that suppresses fluctuations in the internal pressure of the head 50 and fluctuations in the internal pressure of the supply flow path 12 due to the pulsating flow caused by the operation of the supply pump 20. The drain flow path 28 communicates with the liquid chamber 24 through the bubble discharge port 27, and is a flow path for forcibly discharging the liquid in the liquid chamber 24. The drain valve 30 shown in FIG. Then, the ink in the liquid chamber 24 is sent to the ink tank 52 through a predetermined flow path.

  The air chamber 26 is configured to be able to communicate with the atmosphere via an air valve 40 provided in the atmosphere communication channel 38. Therefore, the air chamber 26 can communicate with the air chamber 26 by opening the air valve 40. Further, the atmosphere communication flow path 38 includes a pressure sensor 44 that detects the internal pressure of the air chamber 26 of the supply sub tank 18.

  FIG. 3 is a cross-sectional view illustrating a structural example of the supply sub tank 18. As shown in the figure, the supply sub-tank 18 partitions the inside of the sealed container using an elastic film 22, and one side of the elastic film 22 is a liquid chamber 24 and the other side is an air chamber 26. When ink flows from the ink inlet 24B, the elastic film 22 is deformed to the air chamber 26 side so that the pressure in the liquid chamber 24 (ink feeding amount) and the pressure in the air chamber 26 are balanced. With this structure, the supply sub tank 18 functions as a damper even if pressure fluctuation occurs in the supply flow path 12. Further, the ink outlet 24A and the ink inlet 24B are provided on the surface of the liquid chamber 24 opposite to the elastic film 22, and have a structure in which ink is supplied upward from the lower side. Furthermore, a bubble discharge port 27 for discharging bubbles accumulated in the liquid chamber 24 is provided on the surface of the liquid chamber 24 opposite to the elastic film 22, and the drain flow path 28 is connected to the drain channel 28 via the bubble discharge port 27. Communicate. The bubble discharge port 27 is provided at the uppermost portion because the bubbles can easily escape from the upper portion, and the ink outlet 24A is provided at the lowermost portion where the bubbles do not easily flow so as not to flow into the head.

  The air chamber 26 of the supply sub-tank 18 shown in FIG. 3 has a bowl-shaped (dome-shaped) shape in which a surface (facing surface) 26A facing the elastic membrane 22 is a curved surface. Even if it deforms and comes into contact with the opposing surface 26A, the elastic film 22 is not damaged by hitting the corner, and the durability of the elastic film 22 is ensured. In addition, an air channel communication port 26 </ b> B that communicates with the atmosphere communication channel 38 (see FIG. 2) is provided on the wall that constitutes the facing surface 26 </ b> A of the air chamber 26.

(Control system configuration)
FIG. 4 is a block diagram showing a schematic configuration of a control system of the ink supply apparatus 10 shown in this example. The ink supply device 10 shown in FIG. 1 includes a system control unit 70 that performs overall control of the control system, a pump control unit 72 that controls the supply pump 20 based on a control signal sent from the system control unit 70, and a supply valve 14. And a valve controller 74 for controlling the opening and closing of valves such as the drain valve 30 and the air valve 40, and a display device 75 for notifying that when an abnormality occurs in each part of the apparatus.

  The parameter storage unit 80 shown in FIG. 4 stores various parameters used for control of the ink supply device 10 and a data table referred to during control. For example, a data table showing the relationship between the volume of the supply sub-tank 18 and the drive time of the supply pump 20 described later, a data table showing the relationship between the drive time of the supply pump 20 and the amount of ink delivered, or the pressure sensor 44 A data table indicating the relationship between the detected pressure of the air chamber and Pair, which is the pressure at which the elastic film 22 sticks to the facing surface 26A of the air chamber 26, is stored.

  The program storage unit 82 stores a program used for controlling the ink supply apparatus 10. The system control unit 70 reads out and executes various control programs stored in the program storage unit 82, and controls the ink supply device 10 by referring to various parameters and data tables stored in the parameter storage unit 80. Control.

  The ink supply device 10 shown in this example includes a timer (not shown), measures the elapsed time from the start of ink feeding and the elapsed time from opening and closing of the valve, and the measurement results are sequentially stored in a memory (not shown). Written. Alternatively, based on the pressure information in the air chamber 26 obtained from the pressure sensor 44, the operation of the valves such as the supply valve 14 is controlled, and the operation of the supply pump 20 is controlled.

  Next, a configuration example when the non-circulating ink supply device 10 is applied as an ink supply device of a multi-type inkjet head will be described. The configuration example shown in FIG. 5 shows an example in which ink is supplied from the non-circulating ink supply device 10 ′ to the inkjet head 50 ′. 5 that are the same as or similar to those in FIG. 1 are assigned the same reference numerals, and descriptions thereof are omitted.

  The head 50 ′ shown in FIG. 5 is configured by connecting n head modules 51-1 to 51-n. The head module 51 constituting the head 50 ′ is supplied with ink from a supply-side manifold 54 that communicates with the supply flow path 12 through a flow path that is individually branched corresponding to each head module 51. Each of the individual flow paths is provided with supply valves 14-1 to 14-n and dampers 15-1 to 15-n.

  In the ink supply devices 10 and 10 'described above, the opening and closing of the supply valve 14 and the air valve 40 are controlled when the position of the elastic film 22 provided in the supply sub tank 18 is initialized (initial position adjustment), and the supply pump Twenty rotation directions are switched.

(Film position initialization control)
<< First Embodiment >>
FIG. 6 is a flowchart showing the flow of the film position initialization control of the elastic film 22. In the supply sub tank 18 (see FIGS. 1 to 3) shown in this example, the deformation amount (position) of the elastic film 22 changes with time. When the position of the elastic film 22 changes, the pressure control of the supply flow path 12 varies. Therefore, the initial position adjustment of the elastic film 22 is appropriately performed, and variations in the pressure control of the supply flow path 12 are avoided. Examples of the timing at which the initial position adjustment of the elastic film 22 is performed include when the pressure in the supply flow path 12 is greatly changed due to an abnormality of the supply pump 20 or the like after the start-up of the apparatus or after execution of the pressure purge. .

  As shown in FIG. 6, when the film position initialization control of the elastic film 22 is started (step S10), the supply valve 14 is closed (step S12), and the supply flow path 12 and the head 50 are disconnected. . Thereafter, the air valve 40 is opened (step S14), and the air chamber 26 is released to the atmosphere. In this state, the supply pump 20 is rotated forward to pressurize the liquid chamber 24, and ink is fed into the liquid chamber 24 (step S16). The drive time of the supply pump 20 can be determined by the volume of the supply sub-tank 18 (the sum of the volume of the air chamber 26 and the liquid chamber 24) and the ink feeding speed. Specifically, the driving time is determined so as to satisfy (driving time) × (ink supply speed) = (sum of volume amounts of the air chamber 26 and the liquid chamber 24). Thereby, at the time when the driving time ends, an amount of ink that satisfies the volume in the supply sub-tank 18 can be sent to the supply sub-tank 18, so that the supply sub-tank 18 can be filled with the liquid chamber 24. The elastic film 22 of the supply sub tank 18 can be attached to the facing surface 26A of the air chamber 26 (step S18). In this embodiment, since the relief valve 42 is provided on the ink inlet 24B side of the supply flow path 12, the supply amount of ink supplied to the supply sub tank 18 and the pressure value of the liquid chamber 24 are monitored. However, even if the supply amount increases, the relief valve 42 can prevent the pressure in the supply sub tank 18 from increasing.

  After the specified time has elapsed (Yes determination), the air valve 40 is closed and shut off from the atmosphere (step S20). Thereafter, the supply pump 20 is driven reversely to depressurize the liquid chamber 24, and ink is discharged from the liquid chamber 24 (step S22). The drive time of the supply pump 20 can be determined by the volume of the air chamber 26 and the ink discharge speed. By obtaining the drive time by (drive time) × (ink discharge speed) = (volume of the air chamber 26), the volume of ink in the air chamber 26 can be discharged at the time when the drive time ends ( Step S24). The volume of the air chamber 26 is set so that the elastic force of the elastic film 22 is not generated. Since the initial position of the elastic film 22 is determined by the amount of ink discharged in step S24, the effect of the pressure buffering part that suppresses the pulsation of the pump is achieved by setting the elastic film 22 in a state where no elastic force is generated. Can do.

  After the designated time has elapsed (Yes determination), the film position initialization control ends (step S26). In step S24, a predetermined amount of ink (volume of the air chamber 26) has been discharged from the supply sub-tank 18, and the elastic film 22 is deformed in a direction to contract the liquid chamber 24 in accordance with the discharged amount of ink. , Adjusted to the determined initial position. By closing the air valve 40 and then discharging the ink, the film position can be set at a desired position in a negative pressure state.

<< Second Embodiment >>
Next, a second embodiment of the film position initialization control will be described. FIG. 7 is a flowchart showing the flow of the film position initialization control of the elastic film 22 according to the second embodiment.

  When the film position initialization control of the elastic film 22 is started (step S30), the supply valve 14 is closed as in the first embodiment (step S32). The air valve 40 remains closed. In this state, the supply pump 20 is rotated forward to pressurize the liquid chamber 24, and ink is fed into the liquid chamber 24 (step S34). The ink feeding into the liquid chamber 24 is driven until the pressure monitored by the pressure sensor 44 becomes Pair (step S36).

  Pair is determined by measuring the static response between the hydraulic pressure and air pressure shown in FIG. 8 before the film position initialization control. FIG. 8 is a graph showing the relationship between the pressure in the air chamber and the pressure in the liquid chamber with respect to the amount of ink supplied into the supply sub tank 18. In FIG. 8, the middle point of the region not affected by the elastic membrane is 0 ml.

  The static response shown in FIG. 8 is measured by supplying ink to the liquid chamber 24 with the air valve 40 closed and recording the pressures of the pressure sensor in the liquid chamber 24 and the pressure sensor in the air chamber 26.

  As shown in FIG. 8, when the ink amount in the supply sub tank 18 is in the range of −13 mL to 13 mL (region (2) in FIG. 8), the pressure in the liquid chamber and the pressure in the air chamber show the same numerical value. In this range, as shown in FIG. 9A, the elastic film 22 is not stretched and is not affected by the film elastic force of the elastic film 22. When the amount of ink exceeds about 13 mL, the pressure in the liquid chamber is higher than the pressure in the air chamber (region (1) in FIG. 8), which is elastic as shown in FIG. 9 (b). This is because the membrane elastic force is applied to the liquid chamber 24 because the membrane 22 is stretched, and the pressure in the liquid chamber 24 is balanced by the sum of the air pressure from the air chamber 26 and the membrane elastic force of the elastic membrane 22. Thereafter, when the ink amount exceeds about 23 mL, the pressure in the liquid chamber 24 rapidly increases. This is because the elastic film 22 sticks to the facing surface 26A of the air chamber 26 of the supply sub tank 18 and the inside of the supply sub tank 18 is in a rigid box state.

  Therefore, the pressure sensor 44 reaches the specified pressure Pair by setting the pressure of the air chamber 26 corresponding to the ink supply amount in which the pressure of the liquid chamber 24 has rapidly increased to Pair (about 0 kPa in FIG. 8). It can be determined that the elastic film 22 has reached the pressure to stick to the facing surface 26 </ b> A of the air chamber 26.

  In step S36, when the value of the pressure sensor 44 becomes Pair (Yes determination), the air valve 40 is opened (step S38). As a result, the pressure on the air chamber 26 side is released, and the elastic film 22 can be stuck to the facing surface 26A of the air chamber 26 by passing the specified time (step S40) (Yes determination). Next, the air valve 40 is closed, and the elastic film 22 is fixed to the facing surface 26A of the air chamber 26 (step S42).

  Thereafter, similarly to the first embodiment, the supply pump 20 is driven in reverse to reduce the pressure of the liquid chamber 24 and the ink is discharged from the liquid chamber 24 (step S44). Similarly to the first embodiment, the driving time of the supply pump 20 can also be determined so as to satisfy (driving time) × (ink discharge speed) = (volume of the air chamber 26) (step S46). .

  After a predetermined time has elapsed (Yes determination), a predetermined amount of ink (volume of the air chamber 26) has been discharged from the supply sub-tank 18, and the elastic film 22 contracts the liquid chamber 24 in accordance with the amount of ink discharged. In this direction, the film is adjusted to a predetermined initial position, and the film position initialization control of the elastic film 22 is finished (step S48).

(Overall configuration of circulating ink supply device)
Next, the circulation type ink supply device will be described. The ink supply device 100 shown in FIG. 10 is different from the non-circulation type ink supply device shown in FIG. 1 in that it is a circulation type provided with a circulation system. In the following description, a configuration different from the non-circulating ink supply device 10 described above will be mainly described.

(overall structure)
The ink supply apparatus 100 shown in the figure has a supply channel 12 and a recovery channel 112. A supply subtank 18 is provided in the supply channel 12, and a recovery subtank 118 is provided in the recovery channel 112. The supply sub tank 18 communicates with the ink tank 52 via the supply pump 20 and a predetermined ink flow path, and the recovery sub tank 118 communicates with the ink tank 52 via the recovery pump 120 and the predetermined ink flow path.

  A head 50 shown in FIG. 10 is a head having a structure in which n head modules 51-1, 51-2,..., 51-n are connected to each other. , 14-n communicates with the supply flow path 12, and with the collection valves 114-1, 114-2,..., 114-n communicates with the recovery flow path 112.

  The supply side manifold 54 and the recovery side manifold 154 are temporary storage portions for ink provided between the supply flow path 12 and the recovery flow path 112 and the head 50. The supply side manifold 54 and the recovery side manifold 154 are communicated with each other by bypass passages 190 and 192, and the bypass passages 190 and 192 are provided with bypass passage valves 194 and 196, respectively.

  A tube pump is applied to the supply pump 20 and the recovery pump 120. The supply pump 20 shown in FIG. 10 controls the pressure (liquid feeding amount) of the supply flow path 12 that supplies ink from the ink tank (buffer tank) 52 to the head 50, and the recovery pump 120 moves from the head 50 to the ink tank 52. The pressure (liquid feeding amount) of the recovery flow path 112 that recovers (circulates) the ink is controlled. A pump having the same performance (capacity) can be applied to the supply pump 20 and the recovery pump 120.

  The supply pump 20 and the recovery pump 120 rotate only in one direction during the period when the operation of the head 50 is stopped (that is, the period when the ink flows stably), and the head 50 performs the discharge operation. When the internal pressure decreases during the period, the supply pump 20 increases the rotation speed, and the recovery pump 120 reverses to increase the internal pressure of the head 50.

  The supply sub-tank 18 and the recovery sub-tank 118 have the same structure as the supply sub-tank 18 illustrated in FIG. 3, and thus description thereof is omitted here. Note that the drain flow path 128, the drain valve 130, the air communication flow path 138, the air valve 140, and the pressure sensor 144 in the circulation system (recovery side) illustrated in FIG. It corresponds to the atmosphere communication flow path 38, the air valve 40, and the pressure sensor 44.

  The drain valve 130 is a latch type electromagnetic valve, and the supply valve 14, the recovery valve 114, and the air valve 140 are normally closed type electromagnetic valves. The air connect valve 34 is a normally open electromagnetic valve.

  The ink supply device 100 shown in FIG. 10 is provided with a deaeration module 160 and a one-way valve 162 for preventing the backflow of ink between the ink tank 52 and the supply pump 20, and the supply pump 20 and the supply subtank 18. Between these, a filter 164 and a heat exchanger (cooling heating device) 166 are provided. The ink sent out from the ink tank 52 is subjected to a deaeration process by the deaeration module 160, air bubbles and foreign matters are removed by the filter 164, a temperature adjustment process is performed by the heat exchanger 166, and then sent to the supply sub tank 18. .

  In addition, a one-way valve 170 for preventing back flow of ink is provided between the deaeration module 160 and the recovery pump 120, and a filter 172 is provided, and ink is sent from the ink tank 52 to the recovery sub tank 118. Even in this case, predetermined degassing processing and filtering processing are performed.

  Further, the ink supply device 100 is provided with safety valves (relief valves) 174 and 176, and an abnormality occurs in the supply pump 20 and the recovery pump 120, and the internal pressures of the supply flow path 12 and the recovery flow path 112 are a predetermined value. If the pressure rises further, the safety valves 174 and 176 operate to lower the internal pressures of the supply flow path 12 and the recovery flow path 112. In addition, one-way valves 178 and 180 are provided for preventing the back flow of ink when the supply pump 20 and the recovery pump 120 are operated in reverse.

  The main tank 56 shown in FIG. 10 stores ink supplied to the ink tank 52. When the ink amount in the ink tank 52 decreases, the replenishment pump 182 is operated to send the ink in the main tank 56 to the ink tank 52. The main tank 56 is provided with a filter 184 therein.

(Explanation of circulation)
The ink supply apparatus 100 having such a configuration operates the supply pump 20 and the recovery pump 120 to provide a differential pressure between the supply side manifold 54 and the recovery side manifold 154 to circulate ink. For example, with the supply valve 14 and the recovery valve 114 open, the supply pump 20 is rotated forward to generate negative pressure in the supply-side manifold 54, while the recovery pump 120 is operated in reverse to move to the recovery-side manifold 154. When a negative pressure lower than that on the supply side is generated, ink can flow from the supply side manifold 54 to the recovery side manifold 154 via the head 50, and further, the ink can be circulated via the recovery flow path 112, the recovery sub tank 118, and the like. .

  When the ink is circulated, the second bypass passage valve 196 provided in the second bypass passage 192 is opened, and the supply side manifold 54 and the recovery side manifold 154 are connected via the second bypass passage 192. It is good to communicate. Any one of the bypass channels 190 and 192 may be provided as long as the bypass channels 190 and 192 have a diameter that does not cause pressure loss during pressurization.

(Film position initialization control)
The ink supply apparatus 100 shown in FIG. 10 can independently operate the supply side supply valve 14, the air valve 40, and the supply pump 20, and the recovery side recovery valve 114, the air valve 140, and the recovery pump 120. The present invention can also be applied to the film position initialization control of the elastic film 22 described with reference to FIGS. That is, on the collection side, in order to pressurize the collection sub tank 118, the collection sub tank 118 can be pressurized by reversing the collection pump 120, and to reduce the pressure, The collection sub-tank 118 can be depressurized by causing the collection pump 120 to perform normal rotation.

  By performing the film position initialization control of the elastic film, the initial position of the elastic film 22 that isolates the liquid chamber 24 and the air chamber 26 in the supply sub-tank 18 is appropriately adjusted. (Position) does not change, and variations in pressure control are avoided.

(Another embodiment of pressure adjusting device)
FIG. 11 is a diagram showing a configuration of another embodiment of the pressure adjusting device (supply sub tank 18). In the supply sub-tank 18 shown in FIG. 11, the air chamber 26 communicates with the air tank 36 via the air flow path 32 and the air connect valve 34, and the air tank 36 passes through the air valve 40 provided in the air communication flow path 38. 1 and 2 is different from the pressure adjusting device shown in FIGS. A pressure sensor 44 is provided in the air flow path 32. That is, the air chamber 26 can communicate with the air tank 36 by opening the air connect valve 34. Further, the air connect valve 34 and the air valve 40 can be opened to communicate with the atmosphere.

  The air tank 36 that functions as a buffer tank for the air chamber 26 preferably has a volume that is three times the maximum volume of the air chamber 26. The “maximum volume of the air chamber 26” is the volume of the air chamber 26 in a state where the elastic film 22 is located at the initial position (position adjusted by the above-described film position initialization control). If the volume of the air tank 36 is increased, the capacity when a large pressure is required, such as when performing a pressure purge of the inkjet head, can be increased. On the other hand, if the volume of the air tank 36 is increased too much, the responsiveness of the pressure control is lowered, so that there is an optimum value for the total volume of the air chamber 26 and the volume of the air tank 36. Further, it is preferable that the volume of the air chamber 26 is large from the viewpoint of the pressure buffering function. However, since the deformation amount of the elastic film 22 is limited, the volume of the air chamber 26 is limited by the deformation amount of the elastic film 22.

(Membrane fixation control)
«Third embodiment»
Next, control for fixing the elastic film 22 in the supply sub-tank 18 using the pressure adjusting device of FIG. 11 will be described. The elastic film 22 is fixed when a pressure purge for forcibly discharging the ink in the head 50 with the internal pressure of the head 50 (see FIG. 1) as a positive pressure is performed. Hereinafter, the control of the supply valve 14, the air connect valve 34, the air valve 40 and the control of the supply pump 20 when the membrane fixing control is executed will be described.

  FIG. 12 is a flowchart of the membrane fixing control (step S110). The film fixing control is a process in which the elastic film 22 is deformed and attached to the facing surface 26A of the air chamber 26. When the membrane fixing control is started, the supply valve 14 and the drain valve 30 are closed (step S112), the air connect valve 34 is opened (step S114), the air valve 40 is opened (step S116), the air chamber 26 and the air tank 36 communicates with the atmosphere.

  In this state, the supply pump 20 is rotated forward to pressurize the liquid chamber 24 (step S118). The normal rotation driving time of the supply pump 20 can be determined by the volume of the supply sub tank 18 (the sum of the volume of the air chamber 26 and the liquid chamber 24) and the ink feeding speed. By obtaining the drive time by (drive time) × (ink supply speed) = (sum of the capacities of the air chamber 26 and the liquid chamber 24), the elastic film 22 in the supply sub tank 18 is obtained when the drive time ends. Can be attached to the facing surface 26 </ b> A of the air chamber 26. Further, after the drive time has elapsed, the ink corresponding to the capacity of the supply subtank 18 can be supplied into the supply subtank 18 into the liquid chamber 24, so that the elastic film 22 is located at any position in the supply subtank 18. Alternatively, the elastic film 22 can be attached to the facing surface 26 </ b> A of the air chamber 26. Further, although the amount of ink fed and the pressure in the liquid chamber 24 are not monitored when the ink is supplied to the liquid chamber 24, the pressure in the supply subtank 18 increases because the relief valve 42 is provided. Can be prevented.

  When the elastic membrane 22 is stuck to the facing surface 26A of the air chamber 26, the air connect valve 34 is closed (step S122), the air valve 40 is closed (step S124), and the membrane position fixing control is finished ( Step S126).

  In the circulation type ink supply apparatus shown in FIG. 10, the film fixing control can be performed by the same method.

  Further, although the film fixing control is performed using the pressure adjusting device shown in FIG. 11, the opening and closing of the air valves 40 and 140 of the ink supply device shown in FIGS. Thus, the film fixing control can also be performed for the ink supply devices shown in FIGS.

<< Fourth Embodiment >>
Next, a fourth embodiment of membrane fixation control will be described. FIG. 13 is a flowchart showing a flow of film fixing control of the elastic film 22 according to the fourth embodiment.

  First, the pressure Pair of the air chamber corresponding to the pressure of the liquid chamber where the elastic film 22 sticks to the facing surface 26A of the air chamber 26 is measured and stored in the memory.

  Pair is determined by measuring the static response between the hydraulic pressure and the air pressure shown in FIG. 8 by the same method as the film position initialization control of the elastic film. Specifically, the static response is measured by the following method. Ink is supplied to the liquid chamber 24 with the air valve 40 closed and the air connect valve 34 opened. The ink supply amount to the liquid chamber 24 and the pressure values of the pneumatic pressure sensor and the liquid pressure sensor are recorded, and the static response shown in FIG. 8 is measured by repeating these. In a state where tension is generated in the elastic film 22, a film elastic force acts on the elastic film 22, so that a numerical value is different between the pneumatic pressure sensor and the liquid pressure sensor (region (1) in FIG. 8). . Thereafter, when the elastic film 22 sticks to the facing surface 26A of the air chamber 26 of the supply sub-tank 18, the numerical value of the liquid pressure sensor becomes constant. By recording the numerical value of the pneumatic pressure sensor in this state as Pair, the elastic film 22 sticks to the facing surface 26A of the air chamber 26 when the numerical value of the pneumatic pressure sensor reaches Pair. Can be determined.

  Returning to FIG. 13, when the film position fixing control of the elastic film 22 is started (step S130), the supply valve 14 and the drain valve 30 are closed (step S132), the air connect valve 34 is opened, and the air valve 40 is closed. The state remains unchanged (step S134). As a result, the air chamber 26 and the air tank 36 are communicated with each other, but the air chamber 26 and the air tank 36 are disconnected from each other.

  In this state, the supply pump 20 is rotated forward to pressurize the liquid chamber 24 (step S136). The ink feeding into the liquid chamber 24 is driven until the pressure monitored by the pressure sensor 44 reaches the previously measured Pair (step S138). As described above, by setting the pressure sensor 44 to the value of Pair, it can be determined that the elastic film 22 has reached the pressure to stick to the facing surface 26 </ b> A of the air chamber 26.

  In step S138, when the value of the pressure sensor 44 becomes Pair (Yes determination), the air valve 40 is opened (step S140). As a result, the pressure on the air chamber 26 side is released, and the elastic film 22 can be stuck to the facing surface 26A of the air chamber 26 when the specified time elapses (step S142) (Yes determination). Next, the air valve 40 is closed, and the elastic film 22 is fixed to the facing surface 26A of the air chamber 26 (step S144).

  Thereafter, the air connect valve 34 is closed (step S146), and the film position fixing control ends (step S148).

  Moreover, although the film fixing control has been described using the pressure adjusting device shown in FIG. 11, the film position initialization control can also be performed using the pressure adjusting device shown in FIG. When the pressure adjusting device shown in FIG. 11 is used, the above-described film position initialization control is performed in the same manner by opening and closing the air connect valve 34 and the air valve 40 so as to communicate with the atmosphere or communicate with the air tank 36. Can be implemented.

(Pressure purge)
The film fixing control is performed when it is necessary to feed ink without being affected by the elastic film 22 when the ink is fed at a high pressure such as pressure purge. Hereinafter, a pressure purge method will be described as an example of an operation performed after the film fixing control.

<Non-circulating ink supply device>
FIG. 14 is a flowchart showing the flow of control of pressure purge. As shown in the figure, the pressure purge is composed of a film position fixing process (step S220), a pressure storage process (step S240), and an ink discharging process (step S240).

  The film position fixing step (step S220) can be performed by the method described above. After completion of the film position fixing process, a pressure storage process (step S240) is performed.

  FIG. 15 is a flowchart of the pressure storage process of the non-circulating ink supply device shown in FIGS. When the elastic film 22 is fixed in a state of sticking to the facing surface 26A of the air chamber 26 by the film position fixing process, the pressure storage process is started. The pressure storage step is a step of filling the liquid chamber 24 in the maximum volume state with ink and storing the pressure required for purging in the supply sub tank 18 (and the supply flow path 12). That is, in the pressure storage process, with the supply valve 14 closed, the liquid chamber 24 is pressurized while monitoring the pressure detected by the pressure sensor 44, and the pressure is increased until the pressure detected by the pressure sensor 44 reaches the specified pressure. Continue (step S242). When the detected pressure of the pressure sensor 44 becomes a specified pressure, the liquid chamber 24 and the supply flow path 12 are filled with ink, and a predetermined pressure is stored in the supply subtank 18 and the supply flow path 12. The process ends (step S244).

  FIG. 16 is a flowchart of the ink discharging process. The ink discharge process is a process of discharging (purging) ink from the nozzles of the head 50 using the pressure accumulated in the pressure storage process. First, the supply valve 14 is opened (step S262). Then, the ink stored in the pressure storage process flows into the head 50, whereby the internal pressure of the head 50 becomes positive and the ink is discharged from the head 50. At this time, the supply pump 20 is operated in the pressurizing direction so that the internal pressure of the head 50 does not drop (step S263).

  When the ink discharge is started, the elapsed time since the supply valve 14 is opened is monitored (step S264). When the predetermined time has elapsed (Yes determination), the supply valve 14 is closed (step S266), and the supply is performed. The pump 20 is stopped (step S268), and the ink discharging process is ended (step S270). When the pressure purge is completed, the valve control and the pump control transition to predetermined states.

  When the pressure purge is executed, the elastic membrane 22 is fixed in a state where the volume of the liquid chamber is maximized (a state where no pressure loss occurs due to pressure buffering). That is, the elastic film 22 is attached to the facing surface 26 </ b> A of the air chamber 26. In this state, pressure is stored in the supply sub tank 18 and the supply flow path 12. As a result, the time for storing pressure in the supply sub-tank 18 is shortened, the pressure wave of the pressure purge becomes sharp (a pressure characteristic based on a sharp pressure curve can be obtained), and bubbles and foreign matters are removed. The effect that it becomes easy to remove from a nozzle can be acquired.

<Circulating ink supply device>
Next, a pressure purge method for the circulation type ink supply apparatus will be described. Since the pressure purge process and the film position fixing process can be performed in the same process using a non-circulating ink supply device, the pressure storage process (step S340) and the ink discharge process (step S360). explain.

  FIG. 17 is a flowchart of the pressure storage process. In the pressure storage process shown in FIG. 17, after the first bypass flow path valve 194, the second bypass flow path valve 196, and the recovery valve 114 are closed (steps S342 to 346), the recovery pump 120 is operated in the pressurizing direction. The pressure is stored in the recovery sub tank 118 until the specified pressure is reached while monitoring the pressure sensor 144 on the recovery side (step S348) (step S350).

  FIG. 18 shows a flowchart of the ink discharging process. In the ink discharging process shown in FIG. 18, after the supply valve 14 of the flow path for performing the pressure purge is opened (step S362), the first bypass flow path valve 194 and the second bypass flow path valve 196 are opened (step S362). S364 to step S366). At this time, the supply pump 20 and the recovery pump 120 are operated in the pressurizing direction so that the pressure does not drop (steps S368 to S370).

  When a predetermined time has elapsed from the start of ink discharge (Yes in step S372), the second bypass flow path valve 196 is closed (step S374), the first bypass flow path valve 194 (step 3276) is supplied. The valve 14 is closed (step S378). Then, the recovery pump 120 is stopped (step S380), the supply pump 20 is stopped (step S382), and the ink discharge process is ended (step S284).

[Application example]
Next, as an application example of the ink supply device described above, an ink jet recording apparatus in which the ink supply devices 10 and 100 described above are applied to the ink supply unit of the ink jet head will be described.

(Overall configuration of inkjet recording apparatus)
FIG. 19 is a configuration diagram showing the overall configuration of the ink jet recording apparatus according to the embodiment of the present invention. The ink jet recording apparatus 200 shown in the figure forms an image on a recording surface of a recording medium 214 based on predetermined image data using an ink containing a color material and an aggregating treatment liquid having a function of aggregating the ink. This is a two-liquid aggregation type recording apparatus.

  The ink jet recording apparatus 200 mainly includes a paper feeding unit 220, a processing liquid application unit 230, a drawing unit 240, a drying processing unit 250, a fixing processing unit 260, and a discharge unit 270. Further, although not shown in FIG. 19, an ink supply device that supplies ink to the drawing unit 240 is provided.

  Transfer cylinders 232, 242, 252, and 262 are provided as means for delivering the recording medium 214 conveyed upstream of the processing liquid application unit 230, the drawing unit 240, the drying processing unit 250, and the fixing processing unit 260. As means for transporting the recording medium 214 while holding the recording medium 214 in each of the coating unit 230, the drawing unit 240, the drying processing unit 250, and the fixing processing unit 260, drum-shaped impression cylinders 234, 244, 254, and 264 are provided. .

  The transfer cylinders 232 to 262 and the impression cylinders 234 to 264 are provided with grippers 280A and 280B that hold the leading end portion of the recording medium 214 at predetermined positions on the outer peripheral surface. The structure in which the gripper 280A and the gripper 280B sandwich and hold the leading end portion of the recording medium 214 and the structure in which the recording medium 214 is transferred between the gripper provided in another impression cylinder or the transfer cylinder are the same, and The gripper 280 </ b> A and the gripper 280 </ b> B are arranged at symmetrical positions moved by 180 ° in the rotation direction of the pressure drum 234 on the outer peripheral surface of the pressure drum 234.

  When the transfer cylinders 232 to 262 and the impression cylinders 234 to 264 are rotated in a predetermined direction with the gripper 280A and 280B holding the leading end of the recording medium 214, the outer circumferences of the transfer cylinders 232 to 262 and the impression cylinders 234 to 264 are rotated. The recording medium 214 is rotated and conveyed along the surface.

  In FIG. 19, only the grippers 280 </ b> A and 280 </ b> B provided in the pressure drum 234 are denoted by reference numerals, and the other grippers of the pressure drum and the transfer drum are omitted.

  When the recording medium (sheet) 214 accommodated in the paper supply unit 220 is fed to the treatment liquid application unit 230, the aggregation process is performed on the recording surface of the recording medium 214 held on the outer peripheral surface of the impression cylinder 234. A liquid (hereinafter simply referred to as “treatment liquid”) is applied. The “recording surface of the recording medium 214” is an outer surface in a state where the pressure drums 234 to 264 are held, and is a surface opposite to a surface held by the pressure drums 234 to 264.

  Thereafter, the recording medium 214 to which the aggregation processing liquid has been applied is sent to the drawing unit 240, and color ink is applied to the area of the recording surface to which the aggregation processing liquid has been applied, thereby forming a desired image.

  Further, the recording medium 214 on which the image of the color ink is formed is sent to the drying processing unit 250, where the drying processing unit 250 performs the drying processing, and after the drying processing, the recording medium 214 is sent to the fixing processing unit 260 to perform the fixing processing. Applied. By performing the drying process and the fixing process, the image formed on the recording medium 214 is fastened. In this manner, a desired image is formed on the recording surface of the recording medium 214, and after the image is fixed on the recording surface of the recording medium 214, the image is conveyed from the discharge unit 270 to the outside of the apparatus.

  Hereinafter, each part (the paper feeding unit 220, the processing liquid application unit 230, the drawing unit 240, the drying processing unit 250, the fixing processing unit 260, and the discharge unit 270) of the ink jet recording apparatus 200 will be described in detail.

(Paper Feeder)
The paper feeding unit 220 is provided with a paper feeding tray 222 and a feeding mechanism (not shown), and the recording medium 214 is configured to be fed one by one from the paper feeding tray 222. The recording medium 214 sent out from the paper feed tray 222 is positioned by a guide member (not shown) so as to be positioned at a gripper (not shown) of the transfer drum (paper feed drum) 232 and temporarily stops. A gripper (not shown) holds the leading end portion of the recording medium 214, and transfers the recording medium 214 to and from the gripper provided in the processing liquid cylinder 234.

(Processing liquid application part)
The processing liquid coating unit 230 includes a processing liquid drum (processing liquid drum) 234 that holds the recording medium 214 delivered from the paper feed cylinder 232 on the outer peripheral surface and transports the recording medium 214 in a predetermined transport direction, and a processing liquid. A treatment liquid application unit 230 that applies treatment liquid to the recording surface of the recording medium 214 held on the outer peripheral surface of the cylinder 234 is configured. When the processing liquid cylinder 234 is rotated counterclockwise in FIG. 17, the recording medium 214 is rotated and conveyed in the counterclockwise direction along the outer peripheral surface of the processing liquid cylinder 234.

  The processing liquid application unit 230 shown in FIG. 19 is provided at a position facing the outer peripheral surface (recording medium holding surface) of the processing liquid cylinder 234. As a configuration example of the processing liquid application unit 230, a processing liquid container in which the processing liquid is stored, a pumping roller that is partially immersed in the processing liquid in the processing liquid container, and pumps up the processing liquid in the processing liquid container, and a pumping roller An embodiment including an application roller (rubber roller) that moves the pumped processing liquid onto the recording medium 214 is exemplified.

  Note that an application roller moving mechanism for moving the application roller in the vertical direction (the normal direction of the outer peripheral surface of the processing liquid cylinder 234) is provided, and the processing liquid is not applied to portions other than the recording medium 214. Is preferred. The grippers 280A and 280B that sandwich the leading end of the recording medium 214 are arranged so as not to protrude from the peripheral surface.

  The treatment liquid applied to the recording medium 214 by the treatment liquid application unit 230 contains a color material aggregating agent that aggregates the color material (pigment) in the ink applied by the drawing unit 240, and the treatment liquid is applied on the recording medium 214. And the ink come into contact with each other, the separation of the color material and the solvent in the ink is promoted.

  The treatment liquid application unit 230 is preferably applied while measuring the amount of the treatment liquid applied to the recording medium 214, and the film thickness of the treatment liquid on the recording medium 214 is determined by the ink droplets ejected from the drawing unit 240. It is preferable to make it sufficiently smaller than the diameter.

(Drawing part)
The drawing unit 240 holds a recording medium 214 and conveys the drawing cylinder (drawing drum) 244, a sheet pressing roller 246 for bringing the recording medium 214 into close contact with the drawing cylinder 244, and an ink jet for applying ink to the recording medium 214. Heads 248M, 248K, 248C, 248Y are provided. The basic structure of the drawing cylinder 244 is common to the processing liquid cylinder 234 described above.

  The sheet pressing roller 246 is a guide member for bringing the recording medium 214 into close contact with the outer peripheral surface of the drawing cylinder 244, faces the outer peripheral surface of the drawing cylinder 244, and delivers the recording medium 214 between the transfer cylinder 242 and the drawing cylinder 244. It is disposed downstream of the position in the transport direction of the recording medium 214 and upstream of the inkjet heads 248M, 248K, 248C, and 248Y in the transport direction of the recording medium 214.

  Further, a paper floating detection sensor (not shown) is disposed between the paper pressing roller 246 and the uppermost ink jet head 248Y in the conveyance direction of the recording medium 214. The sheet floating detection sensor detects the amount of floating immediately before the recording medium 214 enters immediately below the inkjet heads 248M, 248K, 248C, 248Y. In the case where the floating amount of the recording medium 214 detected by the paper floating detection sensor exceeds a predetermined threshold, the inkjet recording apparatus 200 shown in this example notifies that fact and interrupts the conveyance of the recording medium 214. It is configured as follows.

  The recording medium 214 transferred from the transfer cylinder 242 to the drawing cylinder 244 is pressed by the sheet pressing roller 246 when being rotated and conveyed with the front end held by a gripper (not shown), and the outer periphery of the drawing cylinder 244 Adhere to the surface. After the recording medium 214 is brought into close contact with the outer peripheral surface of the drawing cylinder 244 in this way, the recording medium 214 is sent to the print area immediately below the ink jet heads 248M, 248K, 248C, 248Y without being lifted from the outer peripheral surface of the drawing cylinder 244. It is done.

  The inkjet heads 248M, 248K, 248C, and 248Y correspond to inks of four colors, magenta (M), black (K), cyan (C), and yellow (Y), respectively, and the rotation direction of the drawing cylinder 244 (see FIG. 17 (counterclockwise direction in FIG. 17) in order from the upstream side, and the ink discharge surfaces (nozzle surfaces) of the ink jet heads 248M, 248K, 248C, 248Y face the recording surface of the recording medium 214 held by the drawing cylinder 244. To be arranged. The “ink ejection surface (nozzle surface)” is a surface of the inkjet heads 248M, 248K, 248C, and 248Y that faces the recording surface of the recording medium 214, and is a nozzle that ejects ink described later (reference numeral in FIG. 19). This is a surface on which 308 is attached).

  In addition, in the inkjet heads 248M, 248K, 248C, and 248Y shown in FIG. 18, the recording surface of the recording medium 214 held on the outer peripheral surface of the drawing cylinder 244 and the nozzle surfaces of the inkjet heads 248M, 248K, 248C, and 248Y are substantially parallel. In such a manner, it is arranged to be inclined with respect to the horizontal plane.

  The inkjet heads 248M, 248K, 248C, and 248Y are full-line heads having a length corresponding to the maximum width of the image forming area in the recording medium 214 (the length in the direction orthogonal to the conveyance direction of the recording medium 214). The recording medium 214 is fixedly installed so as to extend in a direction orthogonal to the conveyance direction of the recording medium 214. Inkjet heads 248M, 248K, 248C, and 248Y are each supplied with ink from an ink supply device that will be described in detail later.

  On the nozzle surfaces (liquid ejection surfaces) of the inkjet heads 248M, 248K, 248C, 248Y, nozzles for ejecting ink are formed in a matrix arrangement over the entire width of the image forming area of the recording medium 214.

  When the recording medium 214 is transported to the printing area immediately below the inkjet heads 248M, 248K, 248C, and 248Y, the image data is converted into the area where the aggregation processing liquid of the recording medium 214 is applied from the inkjet heads 248M, 248K, 248C, and 248Y. Based on this, ink of each color is ejected (droplet ejection).

  When ink droplets of the corresponding color ink are ejected from the inkjet heads 248M, 248K, 248C, and 248Y toward the recording surface of the recording medium 214 held on the outer peripheral surface of the drawing cylinder 244, processing is performed on the recording medium 214. The liquid and the ink come into contact with each other, and an aggregation reaction of the color material (pigment-based color material) dispersed in the ink or the color material (dye-based color material) to be insolubilized appears, and a color material aggregate is formed. This prevents color material movement (dot misalignment, dot color unevenness) in the image formed on the recording medium 214.

  Further, since the drawing cylinder 244 of the drawing unit 240 is structurally separated from the processing liquid cylinder 234 of the processing liquid application unit 230, the processing liquid does not adhere to the inkjet heads 248M, 248K, 248C, and 248Y. In addition, the cause of abnormal ink ejection can be reduced.

  In this example, the configuration of MKCY standard colors (four colors) is illustrated, but the combination of ink colors and the number of colors is not limited to this embodiment, and light ink, dark ink, and special colors are used as necessary. Ink may be added. For example, it is possible to add an inkjet head that discharges light-colored ink such as light cyan and light magenta, and the arrangement order of the color heads is not particularly limited.

(Dry processing part)
The drying processing unit 250 holds a drying drum (drying drum) 254 that holds and conveys the recording medium 214 after image formation, and a drying processing device 256 that performs a drying process for evaporating moisture (liquid component) on the recording medium 214. It has. The basic structure of the drying cylinder 254 is the same as that of the processing liquid cylinder 234 and the drawing cylinder 244 described above, and a description thereof is omitted here.

  The drying processing device 256 is a processing unit that is disposed at a position facing the outer peripheral surface of the drying drum 254 and evaporates moisture present in the recording medium 214. When ink is applied to the recording medium 214 by the drawing unit 240, the liquid component (solvent component) of the ink and the liquid component (solvent component) of the processing liquid separated by the aggregation reaction between the processing liquid and the ink are placed on the recording medium 214. Since it remains, it is necessary to remove such a liquid component.

  The drying processing device 256 performs a drying process for evaporating a liquid component existing on the recording medium 214 by heating with a heater, blowing with a fan, or a combination thereof, and a process for removing the liquid component on the recording medium 214. Part. The amount of heating and the amount of air supplied to the recording medium 214 are appropriately set according to parameters such as the amount of moisture remaining on the recording medium 214, the type of the recording medium 214, and the conveyance speed (drying processing time) of the recording medium 214. Is done.

  When the drying processing by the drying processing device 256 is performed, the drying cylinder 254 of the drying processing unit 250 is structurally separated from the drawing cylinder 244 of the drawing unit 240, and thus the inkjet heads 248M, 248K, 248C, 248Y. In this case, it is possible to reduce the cause of abnormal ink ejection due to drying of the head meniscus by heat or air blowing.

  In order to exhibit the cockling correction effect of the recording medium 214, the curvature of the drying drum 254 is preferably 0.002 (1 / mm) or more. In order to prevent the recording medium from being curved (curled) after the drying process, the curvature of the drying cylinder 254 is preferably 0.0033 (1 / mm) or less.

  In addition, a means (for example, a built-in heater) for adjusting the surface temperature of the drying drum 254 may be provided, and the surface temperature may be adjusted to 50 ° C. or higher. By performing heat treatment from the back surface of the recording medium 214, drying is promoted, and image destruction during the subsequent fixing process is prevented. In this embodiment, it is more effective to provide means for bringing the recording medium 214 into close contact with the outer peripheral surface of the drying drum 254. As an example of means for closely attaching the recording medium 214, vacuum adsorption, electrostatic adsorption, and the like can be given.

  The upper limit of the surface temperature of the drying cylinder 254 is not particularly limited, but from the viewpoint of safety of maintenance work (such as prevention of burns due to high temperatures) such as cleaning of ink adhering to the surface of the drying cylinder 254. It is preferably set to 75 ° C. or lower (more preferably 60 ° C. or lower).

  The drying drum 254 configured in this manner is held on the outer peripheral surface of the recording medium 214 so that the recording surface of the recording medium 214 faces outward (that is, in a state where the recording surface of the recording medium 214 is convex). By performing the drying process while rotating and transporting, drying unevenness due to wrinkling and floating of the recording medium 214 is surely prevented.

(Fixing processing part)
The fixing processing unit 260 includes a fixing drum (fixing drum) 264 that holds and conveys the recording medium 214, a heater 266 that performs heat treatment on the recording medium 214 on which an image is formed and liquid is removed, and the recording And a fixing roller 268 that presses the medium 214 from the recording surface side. The basic structure of the fixing cylinder 264 is the same as that of the processing liquid cylinder 234, the drawing cylinder 244, and the drying cylinder 254, and a description thereof is omitted here. The heater 266 and the fixing roller 268 are disposed at positions facing the outer peripheral surface of the fixing cylinder 264, and are sequentially disposed from the upstream side in the rotation direction of the fixing cylinder 264 (counterclockwise direction in FIG. 17).

  In the fixing processing unit 260, the recording surface of the recording medium 214 is subjected to preheating processing by the heater 266 and fixing processing by the fixing roller 268. The heating temperature of the heater 266 is appropriately set according to the type of recording medium, the type of ink (the type of polymer fine particles contained in the ink), and the like. For example, a mode in which the glass transition temperature and the minimum film forming temperature of the polymer fine particles contained in the ink are considered.

  The fixing roller 268 is a roller member that heats and presses the dried ink to weld the self-dispersing polymer fine particles in the ink to form a film of the ink, and is configured to heat and press the recording medium 214. The Specifically, the fixing roller 268 is disposed so as to be in pressure contact with the fixing cylinder 264 and constitutes a nip roller with the fixing cylinder 264. As a result, the recording medium 214 is sandwiched between the fixing roller 268 and the fixing cylinder 264, and is nipped with a predetermined nip pressure, and fixing processing is performed.

  As an example of the configuration of the fixing roller 268, an embodiment in which the fixing roller 268 is configured by a heating roller in which a halogen lamp is incorporated in a metal pipe such as aluminum having good thermal conductivity can be given. By heating the recording medium 214 with such a heating roller, when thermal energy equal to or higher than the glass transition temperature of the polymer fine particles contained in the ink is applied, the polymer fine particles are melted to form a transparent film on the surface of the image. Is done.

  When pressure is applied to the recording surface of the recording medium 214 in this state, the polymer fine particles melted into the unevenness of the recording medium 214 are pressed and fixed, and the unevenness of the image surface is leveled, so that preferable glossiness can be obtained. A configuration in which a plurality of fixing rollers 268 are provided in accordance with the thickness of the image layer and the glass transition temperature characteristics of the polymer particles is also preferable.

  The surface hardness of the fixing roller 268 is preferably 71 ° or less. By making the surface of the fixing roller 268 softer, a tracking effect can be expected with respect to the unevenness of the recording medium 214 caused by cockling, and fixing unevenness due to the unevenness of the recording medium 214 is more effectively prevented. .

  In the inkjet recording apparatus 200 shown in FIG. 19, an inline sensor 282 is provided at the subsequent stage (downstream in the recording medium conveyance direction) of the processing area of the fixing processing unit 260. The inline sensor 282 is a sensor for reading an image formed on the recording medium 214 (or a check pattern formed in a blank area of the recording medium 214), and a CCD line sensor is preferably used.

  In the ink jet recording apparatus 200 shown in this example, the presence or absence of ejection abnormality of the ink jet heads 248M, 248K, 248C, and 248Y is determined based on the reading result of the inline sensor 282. Further, the inline sensor 282 may include a measuring unit for measuring a moisture amount, a surface temperature, a glossiness, and the like. In such an embodiment, parameters such as the processing temperature of the drying processing unit 250, the heating temperature of the fixing processing unit 260, and the pressurizing pressure are appropriately adjusted based on the reading results of the moisture amount, the surface temperature, and the glossiness, and the temperature inside the apparatus. The control parameter is adjusted as appropriate in accordance with the change and the temperature change of each part.

(Discharge part)
As shown in FIG. 17, a discharge unit 270 is provided following the fixing processing unit 260. The discharge unit 270 includes an endless conveyance chain 274 wound around the stretching rollers 272A and 272B, and a discharge tray 276 that stores the recording medium 214 after image formation.

  The recording medium 214 after the fixing process sent out from the fixing processing unit 260 is transported by the transport chain 274 and discharged to the discharge tray 276.

[Inkjet head structure]
Next, an example of the structure of the inkjet heads 248M, 248K, 248C, and 248Y provided in the drawing unit 240 will be described. In addition, since the structures of the inkjet heads 248M, 248K, 248C, and 248Y corresponding to the respective colors are the same, hereinafter, the inkjet head (hereinafter also simply referred to as “head”) is represented by reference numeral 300. And

  FIG. 20 is a schematic configuration diagram of the inkjet head 300, which is a diagram (a plan perspective view of the head) of the recording surface of the recording medium as viewed from the inkjet head 300. FIG. The head 300 shown in the figure forms a multi-head by connecting n head modules 302-i (i is an integer from 1 to n) in a line along the longitudinal direction of the head 300. Each head module 302-i is supported by head covers 304 and 306 from both sides of the head 300 in the short direction. It is also possible to configure a multi-head by arranging the head modules 302 in a staggered manner.

  As an application example of a multi-head configured by a plurality of sub-heads, a full-line head corresponding to the entire width of a recording medium can be given. The full-line head has a plurality of nozzles (FIG. 21) corresponding to the length (width) in the main scanning direction of the recording medium in the direction (main scanning direction) orthogonal to the moving direction (sub-scanning direction) of the recording medium. Are attached with a reference numeral 308.) are arranged. An image can be formed on the entire surface of the recording medium by a so-called single-pass image recording method in which image recording is performed by scanning the head 300 having such a structure and the recording medium only once relatively.

  The head module 302-i constituting the head 300 has a plane shape of a substantially parallelogram, and an overlap portion is provided between adjacent sub heads. The overlap portion is a connecting portion of the sub heads, and is formed by nozzles in which adjacent dots belong to different sub heads in the arrangement direction of the head modules 302-i. The head 300 shown in FIG. 20 is equivalent to the head 50 ′ shown in FIG. 5, and the head module 302 is equivalent to the head module 51.

  FIG. 21 is a plan view showing the nozzle arrangement of the head module 302-i. As shown in the figure, each head module 302-i has a structure in which nozzles 308 are two-dimensionally arranged, and a head including such a head module 302-i is a so-called matrix head. . The head module 302-i illustrated in FIG. 19 includes a number of nozzles 308 along a column direction W that forms an angle α with respect to the sub-scanning direction Y and a row direction V that forms an angle β with respect to the main scanning direction X. It has an aligned structure, and the substantial nozzle arrangement density in the main scanning direction X is increased. In FIG. 21, the nozzle group (nozzle row) arranged along the row direction V is denoted by reference numeral 310, and the nozzle group (nozzle row) arranged along the column direction W is denoted by reference numeral 312. ing.

  Another example of the matrix arrangement of the nozzles 308 is a configuration in which a plurality of nozzles 308 are arranged along the row direction along the main scanning direction X and the column direction oblique to the main scanning direction X.

  FIG. 22 is a cross-sectional view showing a three-dimensional configuration of one channel of droplet discharge elements (ink chamber units corresponding to one nozzle 308) serving as a recording element unit. As shown in the figure, a head 300 (head module 302) of this example includes a nozzle plate 314 in which nozzles 308 are formed, and a flow path plate 320 in which flow paths such as a pressure chamber 316 and a common flow path 318 are formed. It has a structure in which etc. are laminated and joined. The nozzle plate 314 constitutes the nozzle surface 314A of the head 300, and a plurality of nozzles 308 communicating with the pressure chambers 316 are two-dimensionally formed.

  The flow path plate 320 constitutes a side wall portion of the pressure chamber 316 and a flow path forming a supply port 322 as a narrowed portion (most narrowed portion) of an individual supply path that guides ink from the common flow path 318 to the pressure chamber 316. It is a forming member. Note that, for convenience of explanation, the flow path plate 320 has a structure in which one or a plurality of substrates are stacked, although it is illustrated schematically in FIG.

  The nozzle plate 314 and the flow path plate 320 can be processed into a required shape by a semiconductor manufacturing process using silicon as a material.

  The common flow path 318 communicates with an ink tank (not shown) as an ink supply source, and the ink supplied from the ink tank is supplied to each pressure chamber 316 via the common flow path 318.

  A diaphragm 324 constituting a part of the pressure chamber 316 (the top surface in FIG. 22) includes an individual electrode 326 and a lower electrode 328, and the piezoelectric body 330 is interposed between the individual electrode 326 and the lower electrode 328. A piezoelectric actuator 332 having a sandwiched structure is joined. When the diaphragm 324 is formed of a metal thin film or a metal oxide film, it functions as a common electrode corresponding to the lower electrode 328 of the piezo actuator 332. In the aspect in which the diaphragm is formed of a non-conductive material such as resin, a lower electrode layer made of a conductive material such as metal is formed on the surface of the diaphragm member.

  By applying a driving voltage to the individual electrode 326, the piezo actuator 332 is deformed to change the volume of the pressure chamber 316, and ink is ejected from the nozzle 308 due to the pressure change accompanying this. When the piezo actuator 332 returns to its original state after ink ejection, new ink is refilled into the pressure chamber 316 from the common flow path 318 through the supply port 322.

As shown in FIG. 19, the ink chamber unit having such a structure is latticed in a fixed arrangement pattern along a row direction V that forms an angle β with the main scanning direction X and a column direction W that forms an angle α with respect to the sub-scanning direction Y. The high-density nozzle head of this example is realized by arranging a large number in the shape. In this matrix arrangement, when the interval between adjacent nozzles in the sub-scanning direction Y is L _s , the nozzles 308 are substantially linearly arranged at a constant pitch P = L _s / tan θ in the main scanning direction X. Can be handled equivalently.

  In this example, the piezo actuator 332 is applied as a means for generating ink ejection force to be ejected from the nozzle 308 provided in the head 300. However, a heater is provided in the pressure chamber 316, and the pressure of film boiling caused by heating of the heater is used. It is also possible to apply a thermal method that ejects ink.

  DESCRIPTION OF SYMBOLS 10, 10 ', 100 ... Ink supply apparatus, 12 ... Supply flow path, 14 ... Supply valve, 18 ... Supply sub tank, 20 ... Supply pump, 22 ... Elastic film, 24 ... Liquid chamber, 26 ... Air chamber, 32 ... Air Flow path, 34 ... Air connect valve, 36 ... Air tank, 38, 138 ... Atmospheric communication flow path, 40, 140 ... Air valve, 42 ... Relief valve, 44, 144 ... Pressure sensor, 50 ... Inkjet head, 112 ... Recovery flow path 118 ... Recovery sub tank, 120 ... Recovery pump, 200 ... Inkjet recording apparatus

Claims (11)

A sealed container having a predetermined volume is configured to be divided into a first air chamber and a first liquid chamber by a first elastic film, and the first liquid chamber includes a nozzle and a flow path. A first tank communicating with a droplet discharge head having
A first liquid feeding means for feeding or discharging a liquid to the first tank;
First gas pressure detection means for detecting the pressure of the first air chamber,
After the first elastic film is attached to the wall of the first air chamber by supplying the first liquid chamber with a specified supply amount of liquid by the first liquid feeding means, First position control means for controlling the position of the first elastic membrane in the first tank by discharging a specified discharge amount of liquid with one liquid feeding means;
A pressure adjusting device. A sealed container having a predetermined volume is configured to be partitioned into a second air chamber and a second liquid chamber by a second elastic film, and the second liquid chamber includes the droplet discharge head. A second tank communicating with the
A second liquid feeding means for feeding or discharging a liquid to the second tank;
Second gas pressure detecting means for detecting the pressure of the second air chamber,
After the second elastic film is attached to the wall of the second air chamber by supplying the second liquid chamber with a specified supply amount of liquid by the second liquid feeding means, Second position control means for controlling the position of the elastic membrane in the second tank by discharging a specified discharge amount of liquid by the two liquid feeding means;
The pressure regulator according to claim 1, comprising:   The designated supply amount is equal to or greater than the total volume of the first air chamber and the first liquid chamber, or the total volume of the second air chamber and the second liquid chamber. The pressure regulator according to claim 1 or 2, wherein the amount of liquid is supplied. A sealed container having a predetermined volume is configured to be divided into a first air chamber and a first liquid chamber by a first elastic film, and the first liquid chamber includes a nozzle and a flow path. A first tank communicating with a droplet discharge head having
A first liquid feeding means for feeding or discharging a liquid to the first tank;
First gas pressure detection means for detecting the pressure of the first air chamber,
When the pressure of the first air chamber corresponding to the pressure of the first liquid chamber where the first elastic film sticks to the wall surface of the first air chamber is Pair ₁ ,
Recording means for recording the pressure Pair ₁ of the first air chamber;
After the liquid is supplied to the first liquid chamber until the pressure of the first gas pressure detection means becomes Pair ₁ by the first liquid supply means, the specified discharge amount is obtained by the first liquid supply means. First position control means for controlling the position of the first elastic membrane in the first tank by discharging the liquid;
A pressure adjusting device. A sealed container having a predetermined volume is configured to be partitioned into a second air chamber and a second liquid chamber by a second elastic film, and the second liquid chamber includes the droplet discharge head. A second tank communicating with the
A second liquid feeding means for feeding or discharging a liquid to the second tank;
Second gas pressure detecting means for detecting the pressure of the second air chamber,
When the pressure of the second air chamber corresponding to the pressure of the second liquid chamber where the second elastic film sticks to the liquid surface of the second air chamber is Pair ₂ ,
Recording means for recording the pressure Pair ₂ of the second air chamber;
After the liquid is supplied to the second liquid chamber until the pressure of the second gas pressure detection means becomes Pair ₂ by the second liquid supply means, the specified discharge amount by the second liquid supply means. A second position control means for controlling the position of the second elastic membrane in the second tank by discharging the liquid;
The pressure adjusting device according to claim 4.   The pressure adjusting device according to any one of claims 1 to 5, wherein the designated drainage amount is an amount at which an elastic force of the elastic membrane is not generated.   The pressure regulating device according to claim 6, wherein the designated drainage amount is equal to a capacity of the air chamber.   The pressure regulator according to any one of claims 1 to 7, further comprising a relief valve in a supply flow path to the tank. The first air chamber includes a first air communication path that communicates with the atmosphere, and a first air communication path switching unit that switches between opening the atmosphere of the first air chamber or blocking the atmosphere.
The second air chamber includes a second air communication path communicating with the atmosphere, and a second air communication path switching means for switching between opening the atmosphere of the second air chamber or blocking the atmosphere.
After the first elastic membrane is attached to the wall surface of the first air chamber, the first atmosphere communication path switching means is switched so as to switch the first atmosphere communication path switching means to shut off from the atmosphere. First elastic membrane fixing control means for
After the second elastic membrane is attached to the wall surface of the first air chamber, the second atmosphere communication path switching means is switched so that the second atmosphere communication path switching means is shut off from the atmosphere. Second elastic membrane fixing control means,
A pressure adjusting device according to any one of claims 1 to 8. A first gas flow path having one end communicating with the first air chamber, a first gas storage section communicating with the other end of the first gas flow path, and the first air chamber; A first gas flow path switching means for switching communication or blocking with the first gas storage unit; a first end communicating with the first gas storage unit; and a first end communicating with the atmosphere. An atmosphere communication path, and first atmosphere communication path switching means for switching between opening the atmosphere of the first gas storage section or blocking the atmosphere, and
A second gas flow path having one end communicating with the second air chamber, a second gas storage section communicating with the other end of the second gas flow path, and the second air chamber; A second gas flow path switching means for switching communication or blocking with the second gas storage unit; a second end that communicates with one end of the second gas storage unit; and a second end that communicates with the atmosphere. An atmosphere communication path, and a second atmosphere communication path switching means for switching between opening the atmosphere of the second gas storage section or blocking the atmosphere, and
In a state where the first gas flow path switching means communicates with the first air chamber and the first gas storage section, and in a state where the first atmosphere communication path switching means is disconnected from the atmosphere, After controlling the liquid feeding means and attaching the first elastic film to the wall surface of the first air chamber, the first air chamber and the first gas storage section are switched to be shut off. First elastic membrane fixing control means for controlling the first gas flow path switching means;
In a state where the second gas flow path switching means communicates with the second air chamber and the second gas storage section, and in a state where the second atmosphere communication path switching means is disconnected from the atmosphere, After controlling the liquid feeding means and attaching the second elastic film to the wall surface of the second air chamber, the second air chamber and the second gas storage unit are switched to be shut off. Second elastic membrane fixing control means for controlling the second gas flow path switching means;
A pressure adjusting device according to any one of claims 1 to 8.   An ink jet recording apparatus comprising the pressure adjusting device according to claim 1.

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