JP2006198845A - Filling method, and liquid delivering apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid delivering apparatus which can efficiently fill a liquid without discharging a large quantity of a liquid, and to provide a filling method in the liquid delivering apparatus. <P>SOLUTION: In a first powerful suction action, after suction is carried out by a suction pump 23 in a state with a choke valve 30a being closed, the closed state is released, and bubbles trapped in a pressure chamber 46 of the upstream side are discharged. In a following second powerful suction action, after suction is carried out by the suction pump 23 in a state with a choke valve 70a being closed so that maximum negative pressure becomes smaller maximum negative pressure than in the first powerful suction action, the closed state is released, and bubbles trapped in an upper filter chamber 64 of the downstream side are discharged. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid ejection apparatus that ejects liquid as droplets using a liquid ejection head, such as an ink jet recording apparatus, a display manufacturing apparatus, an electrode forming apparatus, or a biochip manufacturing apparatus, and filling of liquid in the liquid ejection apparatus Regarding the method.

  2. Description of the Related Art Conventionally, an ink jet printer is known as a liquid ejecting apparatus that ejects droplets from nozzles of an ejection head. Some ink jet printers (hereinafter referred to as printers) include a so-called off-carriage type liquid supply system in which a liquid container is mounted at a place other than a carriage.

  In this liquid supply system, the supply flow path from the ink cartridge to the discharge head on the carriage is configured to include a pressure adjustment mechanism and a head filter chamber provided on the discharge head in addition to the tubular flow path. What is known. The pressure adjustment mechanism includes, for example, a self-sealing valve provided with a pressure adjustment valve and a pressure chamber. In the supply flow path, a choke valve is provided between the pressure adjustment mechanism and the ink cartridge.

  In such a printer, when the liquid is initially filled, for example, when the printer is shipped and used for the first time, a so-called suction operation (by reducing the pressure inside the cap while sealing the nozzle surface of the ejection head with the cap) The ink is filled by, for example, sucking the liquid in the flow path from the nozzle).

In such a printer, when filling the liquid, it is important not to leave bubbles (air layers) in the supply flow path.
However, in the supply flow path, the pressure chamber of the pressure adjusting mechanism and the head filter chamber are widened portions having a cross-sectional area larger than that of the tubular flow path, and bubbles (air layers) are formed in the widened portion. It tends to remain and is a major factor that hinders ink filling.

  Therefore, when the liquid is filled, so-called choke suction (that is, choke suction operation) is performed. This choke suction operation is an operation of increasing the negative pressure on the downstream side of the choke valve by performing the suction operation with the choke valve closed (that is, choked state). If the choke valve is opened from a state in which the negative pressure is increased and air such as the pressure chamber in the supply channel is exhausted in this way, ink can be efficiently filled into the supply channel.

However, when the choke suction operation is performed, the bubbles in the pressure chamber of the pressure adjusting mechanism are discharged and trapped (captured) in the downstream head filter chamber. If the choke suction operation is performed so that the trapped bubbles once again have the same negative pressure (that is, the same maximum negative pressure) as the previous time, they are discharged from the head filter chamber through the discharge head. Since the bubbles in the pressure chamber of the pressure adjusting mechanism are newly discharged, the bubbles are again trapped in the head filter chamber.
Japanese Unexamined Patent Application Publication No. 2003-21688 (for the pressure damper, “paragraph 0026”)

  The amount of bubbles remaining in the pressure chamber of the pressure adjusting mechanism can be reduced by repeating the choke suction operation so as to have the same maximum negative pressure. However, finally, the bubbles in the downstream head filter chamber are reduced to a required size (a size that does not adversely affect the ejection operation by the trapped bubbles, for example, it does not affect the print quality). Requires a large amount of ink suction by repeating the choke suction operation so as to have the same maximum negative pressure. As a result, there is a problem that the liquid cannot be efficiently filled by discharging a large amount of liquid.

  In the above description, a printer is taken as an example, but supply is also possible in a liquid ejecting apparatus that ejects liquid as droplets using another liquid ejecting head such as a display manufacturing apparatus, an electrode forming apparatus, or a biochip manufacturing apparatus. A similar problem occurs in an apparatus provided with a widened portion having a cross-sectional area wider than that of a tubular flow channel in the flow channel.

  An object of the present invention is to provide a liquid ejecting apparatus that can efficiently fill a liquid without discharging a large amount of liquid, and a filling method in the liquid ejecting apparatus.

  In order to solve the above problems, the present invention includes a supply channel that supplies the liquid to a nozzle that discharges the liquid from a liquid container that stores the liquid, and the supply channel includes a tubular channel, Liquid discharge comprising a pair of widened portions that are in communication with the tubular flow channel and are positioned on the upstream and downstream sides, respectively, and includes suction means for sucking gas or liquid in the supply flow channel from the nozzle In the liquid filling method of the supply channel in the apparatus, after the suction channel is aspirated with the supply channel between the liquid container and the upstream widened portion closed, the closed state is released. A first suction step for discharging air bubbles trapped in the upstream widened portion from the widened portion, and supply between the upstream widened portion and the downstream widened portion, which is performed after the first suction step. With the channel closed, After the suction by the pulling means, the filling method is characterized by having a second suction step of releasing the closed state and discharging the bubbles trapped in the widened portion on the downstream side. is there.

Here, the supply flow path includes a supply pipe that connects the liquid container and the discharge head, a connection portion between the discharge head and the supply pipe, a communication flow path for each type of liquid, and for each nozzle.
The widened portion refers to a widened flow path provided in communication with a tubular flow path, for example, a pressure chamber of a pressure regulating valve provided in the middle of a supply pipe, a head Including filter room. The widened portion is a part where the bubbles (air layer) are difficult to escape in the supply flow channel because of the structure, and it is rare that the liquid can be completely filled by a single suction operation or the like. Even if the flow rate (discharge amount) of the liquid by the suction operation or the like is increased, the flow rate passing through the widened portion increases, but the flow around the bubble becomes steady from a certain timing, and the bubble is removed from the widened portion. It is difficult to discharge.

  Conventionally, after a liquid is filled into the entire supply channel, a choke suction operation is performed, and then a series of suction operations for releasing the blocked state are repeated a plurality of times to discharge bubbles that could not be discharged. It was. In this series of suction operations, when the same negative pressure (that is, the same maximum negative pressure) is reached multiple times, the closed state is released and suction is performed.

  In this case, among the plurality of widened portions, the amount of bubbles trapped (captured) in the widened portion located on the upstream side is reduced by discharging the bubbles every time the series of suction operations is repeated. Can do. In the downstream widened portion, some of the bubbles trapped in the widened portion are discharged, but since the bubbles discharged from the upstream side are trapped again, they are trapped in the downstream widened portion. The amount of bubbles will not decrease unless the amount of bubbles discharged from the upstream side decreases. And, since the amount of bubbles trapped in the widened portion on the downstream side is not less than a certain size, it is not possible to suitably discharge droplets from the ejection head, the amount of bubbles trapped in the widened portion on the downstream side is Conventionally, a large amount of liquid suction is required by repeating a series of suction operations including choke suction with the same maximum negative pressure so as to be less than a certain size.

  In contrast, in the filling method of the present invention, in the first suction step, suction is performed from the nozzle by the suction means while the supply flow path between the liquid container and the upstream widened portion is closed. In this case, in the first suction step, the supply pressure is blocked and the negative pressure rises, and when the negative pressure rises to a predetermined negative pressure, the supply flow path between the liquid container and the upstream widened portion is released. . Then, the maximum negative pressure resulting from the increase in the closed state acts, and a rapid liquid flow occurs, and bubbles that were trapped in the widened portion on the upstream side but could not be held are discharged. Certain bubbles remain in the widened portion. On the other hand, even in the downstream widened portion, in the first suction step, when the maximum negative pressure acts, some bubbles are discharged, and instead, the bubbles discharged from the upstream widened portion are discharged. To be compensated.

  In the second suction step, suction is performed from the nozzle by suction means while the supply flow path between the upstream widened portion and the downstream widened portion is closed, the negative pressure is increased, and a predetermined maximum negative When the pressure is reached, the blockage of the supply flow path between the upstream widened portion and the downstream widened portion is released. At this time, the supply channel between the liquid container and the upstream widened portion is also released from the blockage. Then, the maximum negative pressure at this time acts on the widened portion on the downstream side, whereby a rapid flow of liquid occurs, and the bubbles trapped in the widened portion on the downstream side are discharged together with the liquid.

  On the other hand, in the second suction step, the negative pressure increased to the maximum negative pressure is lost before reaching the upstream widened portion, and when the upstream widened portion is filled with liquid, the supply flow path There is no difference from normal suction, which starts suction from the open state. As a result, the bubbles trapped in the upstream widened portion are suppressed from being discharged, and the downstream widened portion is less likely to be filled with bubbles from the upstream widened portion. The amount of bubbles can be reduced.

  As a result, the amount of liquid discharged can be reduced in order to reduce the amount of bubbles trapped in the widened portion on the downstream side, and the liquid can be efficiently filled without discharging a large amount of liquid. Further, the first suction step and the second suction step are performed as initial filling for filling the supply flow path with the liquid from the liquid container so that the user can use the liquid ejection device for the first time.

Here, the initial filling refers to an operation of filling a supply channel with a liquid from a liquid container in order for the user to use the liquid ejection device for the first time.
In this way, the first suction step and the second suction step are performed so that the user uses the liquid discharge device first, so that a large amount of liquid is discharged in the initial filling in which the liquid is filled from the liquid container into the supply channel. Without melting, the liquid can be efficiently melted at the time.

  In addition, after the initial filling, a second suction step or a normal suction step in which suction is performed by the suction means in a state where the supply channel is opened is performed at intervals.

  In this way, after the initial filling, during the interval, bubbles that have been carried from the liquid container to the widened portion on the upstream side are trapped, or gas dissolved in the liquid is trapped as bubbles. The amount of bubbles may increase. Even in such a case, when the second suction step is executed at intervals after the completion of the initial filling, the bubbles trapped in the widened portion on the downstream side can be discharged. Further, when the normal suction step is executed at intervals after the completion of the initial filling, the bubbles trapped in the widened portions on the upstream side and the downstream side can be discharged.

  In addition, since the user uses the liquid ejection device for the first time, as the initial filling for filling the supply channel with the liquid from the liquid container, the first suction step and the suction unit with the supply channel opened are used. Among the normal suction steps for performing suction, at least the first suction step is performed, and the second suction step is performed at intervals.

  When both the first suction step and the normal suction step are executed as the initial filling, the execution order is not limited. As described above, as the initial filling, at least the first suction step of the first suction step and the normal suction step is performed, so that the upstream widened portion was trapped but could not be held. Bubbles are discharged, and certain bubbles remain in the widened portion. On the other hand, even in the downstream widened portion, in the first suction step, when the maximum negative pressure acts, some bubbles are discharged, and instead, the bubbles discharged from the upstream widened portion are discharged. To be compensated. And during the interval, bubbles that have been transported from the liquid container to the widened portion on the downstream side may be trapped, or gas dissolved in the liquid may be trapped and trapped, increasing the amount of bubbles. is there. Also in this case, the air bubbles trapped in the widened portion on the downstream side can be discharged by executing the second suction step.

Further, the second suction step performs the suction of the suction means so that the maximum negative pressure becomes smaller than the first suction step.
In the present specification, a low negative pressure is used to mean a high absolute value of pressure.

  Making the maximum negative pressure in the second suction step smaller than the maximum negative pressure in the first suction step is particularly advantageous when, for example, the distance between the upstream widened portion and the downstream widened portion is short. When the distance between the upstream widened portion and the downstream widened portion is short, the maximum negative pressure is sufficient when the block between the upstream widened portion and the downstream widened portion is released in the second suction step. There is a possibility of reaching the widened portion on the upstream side without being attenuated. However, if the maximum negative pressure in the second suction step is made smaller than the maximum negative pressure in the first suction step, the negative pressure increased more reliably to the maximum negative pressure before reaching the upstream widened portion. Can be lost.

  Further, in the second suction step, a maximum duration smaller than the maximum negative pressure of the first suction step is obtained by shortening the duration of the state in which a part of the supply flow path is closed as compared with the first suction step. It is characterized by negative pressure.

  When the suction operation is started by the suction means, the negative pressure gradually increases until the steady negative pressure is reached due to the capability of the suction means after the suction operation is started. Absolute value is low). For this reason, the control of the maximum negative pressure by the suction means can be performed by controlling the duration after the suction operation is started.

  Therefore, when the suction speeds of the suction means operating in the first suction step and the second suction step are the same, in the second suction step, the duration of the state in which a part of the supply channel is closed is set to the first time. When shorter than the suction step, the maximum negative pressure in the second suction step can be made smaller than the maximum negative pressure in the first suction step.

  In the second suction step, the maximum negative pressure smaller than the maximum negative pressure in the first suction step is set by making the suction speed of the suction means slower than the suction speed of the suction means in the first suction step. It is characterized by.

  In the second suction step, the maximum negative pressure in the second suction step can be made smaller than the maximum negative pressure in the first suction step by making the suction speed of the suction means slower than in the first suction step.

In the second suction step, the suction means is intermittently operated to obtain a maximum negative pressure smaller than the maximum negative pressure of the first suction step.
For example, the suction speed of the suction means is the same in the first suction step and the second suction step, the suction means is continuously operated in the first suction step, and the intermittent operation is performed in the second suction step. Thus, the maximum negative pressure in the second suction step can be made smaller than the maximum negative pressure in the first suction step.

  If the maximum negative pressure of the second suction step can be made smaller than that of the first suction step by intermittent operation of the suction means, the suction speed of the suction means is not necessarily limited to the first and second suction steps. , Need not be the same, and may be different. In short, the maximum negative pressure should be smaller in the second suction step than in the first suction step.

  In addition, after the first suction step is performed, at least the second suction step is performed among the second suction step and the normal suction step in which suction is performed by the suction means with the supply flow path opened. It is characterized by.

  After performing the first suction step, at least the second suction step is executed. Then, the normal suction step may be performed before or after the second suction step. Even if the normal suction step is performed before or after the second suction step, the amount of bubbles trapped in the widened portion on the downstream side can be reduced by the second suction step. As a result, the liquid can be efficiently filled without discharging a large amount of liquid.

  In addition, since the user uses the liquid ejection device for the first time, the first suction step and the second suction step are executed at intervals after the initial filling in which the liquid is filled into the supply flow path from the liquid container. It is characterized by doing.

  In this way, after the initial filling, during the interval, bubbles that have been carried from the liquid container to the widened portion on the upstream side are trapped, or gas dissolved in the liquid is trapped as bubbles. The amount of bubbles may increase. Even in such a case, since the first suction step and the second suction step are executed at intervals after the completion of the initial filling, the liquid is efficiently filled without discharging a large amount of liquid. be able to.

  A supply flow path for supplying the liquid from a liquid container for storing the liquid to a nozzle for discharging the liquid, the supply flow path being in communication with the tubular flow path and the tubular flow path; A pair of widened portions located on the upstream side and the downstream side, a first opening / closing means for opening and closing a supply flow path between the liquid container and the upstream widened portion, and the pair of widened portions A second opening / closing means for opening and closing the supply flow path; a suction means for sucking a gas or liquid in the supply flow path from the nozzle; and the first and second opening / closing means and the suction means. Control means, and the control means controls the first opening / closing means to control the suction means in a state where the supply flow path between the liquid container and the upstream widening section is closed, and suction is performed. After being executed, the first opening / closing means is controlled and closed And then, after the control means controls the second opening / closing means to close the supply flow path between the pair of widened portions, the control means controls the suction means to perform suction. The gist of the liquid ejecting apparatus is to release the closed state by controlling the second opening / closing means.

  According to the present invention, on the other hand, the control means of the liquid ejection device of the present invention is configured so that the supply channel between the liquid container and the upstream widened portion is closed by the first opening / closing means, Control is performed such that suction is performed by suction means. As a result, in the supply flow path, when the negative pressure rises and the negative pressure rises to a predetermined negative pressure, the control means uses the first opening / closing means to control the liquid container and the upstream widening portion. Control is performed so as to release the blockage of the supply channel between them.

  Then, the maximum negative pressure resulting from the increase in the closed state acts, and a rapid liquid flow occurs, and bubbles that were trapped in the widened portion on the upstream side but could not be held are discharged. Certain bubbles remain in the widened portion. On the other hand, in the downstream widened portion, the maximum negative pressure acts, whereby some bubbles are discharged, and instead, the bubbles discharged from the upstream widened portion are compensated.

  Next, the control means controls the second opening / closing means so that the supply passage between the upstream widened portion and the downstream widened portion is closed, and suction is performed by the suction means from the nozzle. Control. As a result, the negative pressure increases in the supply channel. When the predetermined maximum negative pressure is reached, the control means controls the second opening / closing means to release the blockage of the supply flow path between the upstream widened portion and the downstream widened portion. At this time, the control means controls the first opening / closing means to release the blockage of the supply channel between the liquid container and the upstream widened portion. Then, the maximum negative pressure at this time acts on the widened portion on the downstream side, thereby causing a rapid flow of the liquid, and the bubbles trapped in the widened portion on the downstream side are discharged together with the liquid.

  On the other hand, the negative pressure increased to the maximum negative pressure is lost before reaching the upstream widened portion, and when the upstream widened portion is filled with liquid, the suction is started from the state where the supply channel is opened. There is no change with the normal suction to start. As a result, the bubbles trapped in the upstream widened portion are suppressed from being discharged, and the downstream widened portion is less likely to be filled with bubbles from the upstream widened portion. The amount of bubbles can be reduced.

  As a result, the amount of liquid discharged can be reduced in order to reduce the amount of bubbles trapped in the widened portion on the downstream side, and the liquid can be efficiently filled without discharging a large amount of liquid.

Hereinafter, a preferred embodiment in which the liquid ejection apparatus of the present invention is embodied in a printer having an off-carriage type ink supply system will be described with reference to FIGS.
(Liquid discharge device)
As shown in FIG. 1, the printer 10 includes frames 11a, 11b, and 11c, and a platen 16 in a region surrounded by the frames 11a to 11c. The platen 16 is provided to support a recording medium such as paper and eject ink as a liquid onto the recording medium at the supported position.

  A carriage 15 on which the ejection head 14 is mounted is provided at a position facing the platen 16. The carriage 15 is supported and defined by a carriage guide shaft 12 connected to the inner surfaces of the frames 11a and 11c, and can be reciprocated along the carriage guide shaft 12 via a belt 13 by a carriage drive motor 19. It has become. In this configuration, the ejection head 14 mounted on the carriage 15 ejects ink while moving relative to the recording medium, whereby desired printing can be performed.

  The printer 10 performs color printing by using several types of inks with different color materials, and uses, for example, four colors of ink of black, magenta, cyan, and yellow. These color inks are accommodated in ink cartridges 22a to 22d as liquid containers that can be attached to and detached from the frame, and are inserted into a cartridge holder 20 located on the right side of the drawing. From the cartridge holder 20, supply pipes 18a to 18d configured to communicate with the ink cartridges 22a to 22d are routed, and the carriage 15 is disposed on the carriage 15 via the choke valves 30a to 30d and the upstream filter chambers 50a to 50d. The pressure adjusting mechanisms 17a to 17d are communicated with each other. The upstream filter chambers 50 a to 50 d are provided with a filter 52, and the passing ink is filtered by the filter 52.

  Further, the pressure adjusting mechanisms 17 a to 17 d are communicated with the discharge head 14 via the choke valves 70 a to 70 d, the communication channel 27, and the filter unit 60. In this way, the ink in the ink cartridges 22a to 22d is supplied to the ejection head 14 and can be ejected as droplets from the nozzle 33 (see FIG. 2).

  The printer 10 includes a pressurizing pump unit 28 above the cartridge holder 20 in the drawing (the front side in FIG. 1), and compresses the ink cartridges 22a to 22d through the vent pipes 21a to 21d and the cartridge holder 20. Air can be sent in. The pressurizing pump unit 28 includes, for example, a diaphragm pump and a regulator for pressure adjustment, and can adjust the pressure inside the ink cartridges 22a to 22d.

  The printer 10 includes a maintenance unit 25 on the right side of the platen 16 as shown in FIG. The maintenance unit 25 includes a cap 26 and a wiper 24. The cap 26 can seal the nozzle surface 35 (see FIG. 2) of the ejection head 14 and serves to prevent nozzle clogging in an unused state. Further, it is also used when performing a so-called suction operation in which foreign matter and bubbles mixed in the nozzle are sucked and removed together with ink by reducing the pressure inside the cap 26 with the nozzle surface 35 sealed. The wiper 24 is provided for wiping off droplets adhering to the nozzle surface 35 of the ejection head 14 after a suction operation or the like.

  Next, the ink supply system and the waste liquid system of the printer 10 will be described with reference to FIGS. FIG. 2 is a schematic diagram illustrating a schematic configuration of an ink supply system and a waste liquid system in the printer 10. For convenience of explanation, the supply system and waste liquid system of the ink cartridge 22a will be described below. However, the supply system and waste liquid system of the other ink cartridges 22b to 22d have the same configuration as the supply system and waste liquid system of the ink cartridge 22a. Therefore, the description is omitted.

  In FIG. 2, the ink cartridge 22a is configured such that an ink pack 39 is accommodated in a case 43 formed of plastic or the like. The ink pack 39 is formed by welding a flexible film in a pack shape.

  Ink is stored inside the ink pack 39, and the ink can be led out through the lead-out unit 37. The leading end of the lead-out portion 37 protrudes from the through hole 44 formed in the case 43 to the outside of the case 43 and can be detachably coupled to the coupling portion 38 formed inside the cartridge holder 20. The coupling portion 38 is a hollow needle-shaped member and communicates with the supply pipe 18a. Further, a vent hole 36 is provided in the case 43 of the ink cartridge 22a, and one end of the vent pipe 21a can be inserted.

  With the above configuration, when the ink cartridge 22 a is inserted into the cartridge holder 20, the coupling portion 38 and the lead-out portion 37 are coupled, and one end of the vent pipe 21 a is inserted into the internal space 40 of the case 43 from the vent hole 36. It will be in the state.

  In this state, the ink cartridge 22a is configured so that the internal space 40 is airtight. When compressed air is sent from the pressure pump unit 28 through the vent pipe 21a, the internal pressure of the internal space 40 increases. The ink inside is pressed through the film surface of the ink pack 39. As described above, the ink in the ink pack 39 is pressurized and supplied to the supply pipe 18 a via the lead-out portion 37 and the coupling portion 38. The supply pressure of the air supply by the pressurizing pump unit 28 can be controlled by the control unit 41. That is, the ink supply pressure can be controlled by the control unit 41.

(Choke valve 30a)
A choke valve 30a is provided in the middle of the supply pipe 18a. The choke valve 30a corresponds to first opening / closing means.

  The choke valve 30a is opened when the supply pressure of the ink from the ink cartridge 22a is higher than a predetermined supply pressure value, and supplies the ink to the pressure adjusting mechanism 17a via the upstream filter chamber 50a. . The choke valve 30a is closed when the supply pressure of the ink from the ink cartridge 22a is lower than a predetermined supply pressure value, and blocks the supply of ink to the pressure adjustment mechanism 17a. Thus, the choke valve 30a functions as an on-off valve by controlling the ink supply pressure from the ink cartridge 22a. The supply / blocking (choke) of the ink in the supply flow path K can be controlled by a combination of the choke valve 30a and the control unit 41 that controls the supply pressure.

  FIG. 3A is an explanatory diagram showing a specific configuration of the choke valve 30a. As shown in the figure, a recess 58 is formed on one side surface of a base material 51 made of synthetic resin. In the bottom surface of the recess 58, an introduction path 53 formed through the base material 51 is opened. The introduction path 53 communicates with the supply pipe 18a on the ink cartridge 22a side (see FIG. 2). Further, a convex portion 54 is formed on the bottom surface of the concave portion 58, and a lead-out path 55 is opened on the top surface of the convex portion 54. The lead-out path 55 is formed to penetrate the base material 51 and communicates with the supply pipe 18a of the pressure adjustment mechanism 17a (see FIG. 2).

  As shown in FIG. 3B, the concave portion 58 is sealed by fixing the film 56 made of a flexible material to one side surface of the base material 51 in a state where the concave portion 58 is loosened. Has been. As a result, a sealed pressure chamber 57 is formed by the inner surface (including the bottom surface) of the recess 58 and the film 56. The state in which ink is not supplied to the pressure chamber 57 (the state in which no ink supply pressure is applied) is the state shown in FIG. 3B, that is, the film 56 is led out of the convex portion 54 by atmospheric pressure. The passage 55 is closed, and the introduction passage 53 and the outlet passage 55 are blocked (closed state).

  Here, when ink is supplied from the ink cartridge 22 a to the choke valve 30 a, the ink flows into the pressure chamber 57 through the introduction path 53. When the ink in the pressure chamber 57 is increased, the film 56 is separated from the convex portion 54 as shown in FIG. 3A, that is, the state where the nozzle 33 and the outlet path 55 are communicated (the valve is opened). It becomes.

(Pressure adjustment mechanism 17a; self-sealing valve)
Returning to the description of FIG. 2, the pressure adjustment mechanism 17 a is configured as a self-sealing valve including a pressure adjustment valve 32 and a pressure chamber 46.

  The ink sent from the ink cartridge 22a through the choke valve 30a and the upstream filter chamber 50a is supplied to the pressure adjusting mechanism 17a. At this time, the supply pressure of the ink to the pressure adjusting mechanism 17a is higher than the atmospheric pressure. Therefore, when the ink is supplied to the discharge head 14 with the supply pressure as it is, the ink is supplied from the nozzle 33 of the discharge head 14. Appropriate discharge control is not possible due to leakage. Therefore, pressure is reduced by the pressure adjustment valve 32 provided in the pressure adjustment mechanism 17a, and the internal pressure of the pressure chamber 46 can be adjusted at the nozzle 33 so that an appropriate negative pressure (relative to the atmospheric pressure) is obtained. Yes.

Below, the structure of the pressure adjustment mechanism 17a is demonstrated easily.
FIG. 4 shows an example of the pressure adjustment mechanism 17a in a cross-sectional structure. As shown in FIG. 4, the pressure regulating valve 32 includes a valve body 92 having a substantially T-shaped cross section, and a part of the valve body 92 is inserted into the through-hole 93 a of the partition wall 93 and accommodated in the casing 94 so as to freely advance and retract. Has been. The valve body 92 has a seating portion 92a that can be seated on the opening periphery (seal portion 93b) of the through hole 93a, and is always urged by a spring 95 in such a direction as to seat the seating portion 92a on the seal portion 93b. Yes. Further, on both sides of the valve body 92, film members 96 and 97 for sealing the ink supply chamber 94a and the pressure chamber 46 in the casing 94 are attached. A pressure receiving plate 97 a is attached to the film member 97 so as to face the valve body 92. The ink supply chamber 94a is connected to the supply pipe 18a and supplied with ink. The pressure chamber 46 is connected to the communication flow path 27 so that ink can be led out.

In the non-printing state, the pressure adjusting valve 32 is closed by the urging force of the spring 95 and the ink pressure in the ink supply chamber 94a being applied to the valve body 92.
Here, when the ink is supplied to the ejection head 14 via the communication flow path 27 and the internal pressure in the pressure chamber 46 decreases, the film member 97 is bent inward by the differential pressure from the atmospheric pressure, and the pressure receiving plate. 97a contacts the valve body 92. As the differential pressure between the internal pressure of the pressure chamber 46 and the atmospheric pressure increases, the pressing force of the pressure receiving plate 97a against the valve body 92 increases. When this differential pressure becomes larger than a predetermined value of the differential pressure, the pressing force of the pressure receiving plate 97a is increased. The pressure overcomes the urging force of the spring 95, thereby separating the seating portion 92a from the seal portion 93b (valve open state). At this time, ink flows from the ink supply chamber 94a into the pressure chamber 46, the internal pressure of the pressure chamber 46 is compensated, and the valve body 92 returns to the closed state again. As described above, the internal pressure of the pressure chamber 46 can always be maintained at a constant value by repeating the valve closing state, the internal pressure drop of the pressure chamber 46, the valve opening state, the internal pressure compensation of the pressure chamber 46, and the valve closing state.

  The ink adjusted to an appropriate pressure by the pressure adjusting mechanism 17a passes through the communication flow path 27 and the filter unit 60, and passes through the segment flow path 45 including cavities formed in units of nozzles. It is discharged or discharged from the nozzle 33 by an operation or the like. The discharge head 14 is actually provided with a plurality of communication channels 27, segment channels 45, and nozzles 33. However, for convenience of explanation, the discharge head 14 is represented by a single channel in the figure. .

(Choke valve 70a)
A choke valve 70 a is provided in the middle of the communication flow path 27. The choke valve 70a corresponds to a second opening / closing means.

  The choke valve 70a is configured by, for example, an electromagnetic valve or the like, and can be opened or closed based on a control signal from the control unit 41. When the choke valve 70 a is opened, ink is supplied to the ejection head 14 via the filter unit 60. Further, when the choke valve 70a is closed, the supply of ink to the ejection head 14 is shut off. Thus, the choke valve 70a functions as an on-off valve under the control of the control unit 41. The combination of the choke valve 70a and the control unit 41 that controls the choke valve 70a allows the pressure chamber 46 (corresponding to the upstream widened portion) of the pressure adjusting mechanism 17a and the upper filter chamber 64 (downstream) of the filter unit 60. It is possible to control the supply / blocking (choke) of the ink in the supply flow path K (corresponding to the widened portion on the side).

(Filter unit 60)
As shown in FIG. 5, the filter unit 60 has an upper filter chamber 64 that expands downward in a taper shape in the middle of the flow path connecting the hollow needle 62 and the segment flow path 45, and an upper portion that expands in a taper shape. A filter plate 66 is stretched between the lower filter chamber 65 and the lower filter chamber 65. The taper angles of the upper filter chamber 64 and the lower filter chamber 65 are selected to be about 30 to 60 degrees. The filter unit 60 captures and removes foreign matter in the ink supplied to the ejection head 14 and traps bubbles 67 to prevent foreign matter and bubbles from flowing into the ejection head 14. And each filter chamber of the filter unit 60 is made larger than the cross-sectional area of the communication flow path 27 for the reason of suppressing the pressure loss at the time of ink passing. The total volume of the upper filter chamber 64 and the lower filter chamber 65 is smaller than the volume of the pressure chamber 46.

  Further, when the trapped bubble 67 comes into contact with the filter plate 66, ink does not flow in the contacted portion. Therefore, by adopting the above-described configuration, each filter of the filter unit 60 can be prevented. The chamber is a filter chamber having a shape in which the trapped bubbles 67 are hardly contacted with the filter plate 66 as much as possible. As a result, the bubbles 67 are trapped in the conical upper filter chamber 64 so as to be in contact with the upper central inner wall thereof, and therefore do not come into contact with the filter plate 66 until they expand relatively large.

  As described above, the supply flow path K has a tubular flow path such as the supply pipe 18 a and the communication flow path 27, a pressure chamber 46 of the pressure adjustment mechanism 17 a, and a tubular flow path such as the upper filter chamber 64 of the filter unit 60. And a widened portion having a wider cross-sectional area than the flow path.

  The pressure chamber 46 serving as the upstream widened portion has a portion where bubbles (air layers) tend to accumulate structurally, and it is difficult to discharge the pressure chamber 46 from the pressure chamber 46. The bubbles staying in the pressure chamber 46 may flow into the ejection head 14 during printing operation and cause ejection failure. Therefore, in the filling operation to be described later, it is preferable to ensure that the ink does not leave bubbles in the pressure chamber 46. Is required to be filled.

(Waste liquid system)
As shown in FIG. 6, the maintenance unit 25 is the main component of the waste liquid system of the printer 10. The maintenance unit 25 can seal the nozzle surface 35 of the ejection head 14 and is provided in the middle of the cap 26 having a through hole in the center, a waste liquid tube 29 communicating with the through hole of the cap 26, and the waste liquid tube 29. The suction pump 23, the end of the waste liquid tube 29 are provided with a waste liquid tank 31, and a wiper 24 made of a rubber blade or the like. For example, a tube pump is used as the suction pump 23, and the drive can be controlled by the control unit 41.

  In the suction operation, the nozzle 26 is sealed by the cap 26 and the suction pump 23 is continuously driven in the first embodiment to decompress the space 61 of the sealed nozzle 33, thereby reducing the nozzle 33. Ink the ink from. That is, the suction means is constituted by the cap 26, the waste liquid tube 29, and the suction pump 23.

In this case, if the choke valve 30a is in an open state, new ink is supplied one after another, and the ink continues to flow in the supply flow path K.
On the other hand, when the choke valve 30a is in a closed state, the ink flow from the nozzle 33 stops immediately, and a large negative pressure (low absolute value of pressure) is applied to the pressure chamber 46, the communication flow path 27, and the like. Can be generated. Then, when the choke valve 30a is opened from such a state where the negative pressure is increased, ink flows out at a stretch, and a powerful bubble discharging effect can be obtained. Hereinafter, the suction operation in which the supply flow path K is once closed and suction is performed and the supply flow path K is opened to cause the ink to flow is referred to as a strong suction operation, and the supply flow path K is closed. In this case, it is used separately from normal suction (normal suction operation) in which suction is started from a state where the supply flow path K is open.

(Initial filling)
Next, the initial filling of the printer will be described with reference to FIG. The initial filling is an operation of filling the supply flow path K with ink from the ink cartridges 22a to 22d, and is executed because the user uses the printer 10 for the first time.

In the present embodiment, the initial filling includes a normal suction operation, a first strong suction operation, and a second strong suction operation.
When the initial filling is performed, the supply flow path K of the printer 10 is filled with a preserving liquid (a liquid that is filled at the time of product distribution) in advance, or is not filled with anything (instead of a gas). In the present embodiment, the latter case will be described.

  In the initial filling of the first embodiment, since nothing is filled in the supply flow path K, ink filling is performed by a normal suction operation. That is, the choke valve 30a is opened by controlling the ink supply pressure by the control of the control unit 41, and the choke valve 70a is also opened by the control of the control unit 41 and sealed with the cap 26. The pressure in the space 61 of the nozzle 33 is reduced, and the air or ink in the supply channel K is sucked.

  By this normal suction operation, the pressure chamber 46 of the pressure adjusting mechanism 17a is temporarily filled with ink. The liquid level (meniscus) of the ink obtained by this temporary filling may be anywhere on the downstream side of the supply channel K past the pressure chamber 46. In the present embodiment, the liquid level (meniscus) of the ink is positioned in the segment flow path 45 of the ejection head 14 by the normal suction operation. At this stage, since the ink is not completely filled in the pressure chamber 46 of the pressure adjustment mechanism 17a and the upper filter chamber 64 of the filter unit 60, bubbles are trapped. Next, after the normal suction operation, the following first strong suction operation is performed without taking a long time.

(First powerful suction operation)
As the first suction step, the control unit 41 controls to perform the first strong suction operation. That is, the control of the control unit 41 controls the ink supply pressure so that the choke valve 30a is closed, and the choke valve 70a is controlled to open. Further, the control unit 41 drives and controls the suction pump 23, decompresses the space 61 of the nozzle 33 sealed with the cap 26, and sucks air or ink in the supply flow path K. Then, the control unit 41 determines that the space 61 in the cap 26 has a constant negative pressure, that is, a steady negative pressure (first negative pressure) based on the detection value of the pressure sensor 85 that detects the negative pressure in the supply flow path K. It is determined whether or not the maximum negative pressure P1) in the suction step has been reached. The maximum negative pressure P1 is equivalent to the first maximum negative pressure.

  When it is determined that the negative pressure has reached the steady negative pressure, the control unit 41 controls the ink supply pressure to open the choke valve 30a and to hold the choke valve 70a open. To do. Further, the control unit 41 continues the drive control of the suction pump 23, performs pressure reduction in the space 61 of the nozzle 33 sealed with the cap 26, and sucks air or ink in the supply flow path K. . The time from the closed state to the opening of the choke valve 30a in the first strong suction operation is defined as t1 (valve closing time) (see FIG. 7).

  In this case, the maximum negative pressure P1 obtained in the first suction step is set so that the amount of bubbles trapped and held in the pressure chamber 46 which is the widened portion on the upstream side is equal to or less than a certain amount. Yes. In the present embodiment, the negative pressure in the supply flow path K is detected by the pressure sensor 85, but data of the valve closing time t1 necessary to reach the steady negative pressure is obtained in advance by a test or the like. The control unit 41 may measure the time from the drive time of the suction pump 23 with a timer (not shown), and stop the suction pump 23 after the time t1 has elapsed.

  As described above, when the choke valve 30a is opened, the ink starts to flow at once due to the pressure difference between the negative pressure accumulated in the supply flow path K and the supply pressure on the upstream side. As a result, since the ink in the supply channel K is sucked from the state of the maximum negative pressure P1, in the first suction step, the upstream side pressure chamber 46 (widening) is caused by the maximum negative pressure P1 acting. The bubbles that have been trapped in the part (4) but could not be held in the pressure chamber 46 are discharged, and a certain amount of bubbles remains in the pressure chamber 46. On the other hand, in the downstream upper filter chamber 64 (widened portion), the maximum negative pressure P1 acts, whereby some bubbles are discharged, and instead, the bubbles discharged from the upstream pressure chamber 46 are discharged. Will be compensated. The control unit 41 stops driving the suction pump 23 after a predetermined time since the choke valve 30a is opened as shown in FIG.

As described above, after the first strong suction operation is completed, the second strong suction operation is continuously performed without taking time.
(Second powerful suction operation)
Next, as a second suction step, the control unit 41 controls to perform a second strong suction operation. That is, the control unit 41 determines whether or not the choke valve 70a is closed. When the choke valve 70a is not closed, the control unit 41 controls the choke valve 70a and controls the ink supply pressure. Thus, the choke valve 30a is opened. At the same time, the controller 41 drives the suction pump 23 to reduce the pressure in the space 61 of the nozzle 33 sealed with the cap 26, and sucks air or ink in the supply flow path K.

  And the control part 41 measures the elapsed time from the state which the choke valve 70a closed with the timer. When a time t2 shorter than the valve closing time t1 has elapsed, the control unit 41 opens the choke valve 70a with a control signal. Thus, the control unit 41 closes the choke valve 70a during the time t2 (the time from the closing time to the opening time: closing a part of the supply channel K, rather than the case of the first strong suction operation. The maximum negative pressure P2 is made smaller than the maximum negative pressure P1 of the first strong suction operation by shortening the duration of the state. The maximum negative pressure P2 corresponds to the second maximum negative pressure. By making the total volume of the upper filter chamber 64 and the lower filter chamber 65 smaller than the volume of the pressure chamber 46, the exhaust performance of the filter unit 60 is higher than when exhausting from the pressure chamber 46. The maximum negative pressure P2 can be reduced. The maximum negative pressure P2 is set to a negative pressure so that new bubbles do not flow out of the pressure chamber 46 and some of the bubbles in the upper filter chamber 64 can flow out. The second maximum negative pressure is set by the pump suction speed of the suction pump 23 of the control unit 41, the length of time t2, and the cross-sectional area of the supply channel K (including the upper filter chamber 64 and the lower filter chamber 65). It can be performed based on a test or the like conducted under various conditions such as these.

  On the other hand, the control unit 41 continues the drive control of the suction pump 23, performs pressure reduction in the space 61 of the nozzle 33 sealed with the cap 26, and sucks air or ink in the supply flow path K. . In this way, when the choke valve 30a and the choke valve 70a are opened, the ink starts to flow at once due to the pressure difference between the negative pressure accumulated in the supply flow path K and the supply pressure on the upstream side. In the present embodiment, the suction speed of the suction pump 23 is the same for both the first strong suction operation and the second strong suction operation under the control of the control unit 41. The control unit 41 stops driving the suction pump 23 after a predetermined time since the choke valve 70a is opened as shown in FIG.

  In this manner, in the second strong suction operation, suction is performed with the maximum negative pressure P2 that is smaller than the maximum negative pressure P1 of the first strong suction operation, so that trapping is performed in the upstream pressure chamber 46 (widening portion). The bubbles that have been made are not discharged. On the other hand, in the upper filter chamber 64 (widened portion) on the downstream side, the bubbles discharged and trapped by the first strong suction operation are discharged by the maximum negative pressure P2 of the second strong suction operation. In the second strong suction operation, the downstream upper filter chamber 64 (widened portion) is not exhausted from the upstream pressure chamber 46 (widened portion) and is not compensated for, so the downstream upper filter chamber is not filled. The amount of bubbles trapped in 64 (the widened portion) can be reduced. In this way, it is possible to efficiently fill the liquid without discharging a large amount of liquid.

  In particular, in the case of a liquid ejecting apparatus of a type in which the supply flow path K is provided with a very long flow path as in the off-carriage type printer 10 as in the present embodiment, the movement resistance of ink (that is, liquid) ( When it is difficult to obtain a sufficient flow velocity for eliminating bubbles due to the influence of the loss head), the above effect is greatly enjoyed.

  In the first embodiment, when the suction operation is started by the suction pump 23, the negative pressure is maintained until the maximum negative pressure is reached due to the capability of the suction pump 23 after the suction operation is started. Gradually increases (the absolute value of pressure decreases). For this reason, the control unit 41 can control the maximum negative pressure through the suction pump 23 by controlling the duration after the suction operation is started.

  Therefore, when the suction speed of the suction pump 23 is the same in the first strong suction operation and the second strong suction operation, the duration of the state in which a part of the supply channel K is closed in the second strong suction operation. Is shorter than the first strong suction operation, the maximum negative pressure P2 in the second strong suction operation can be made smaller than the maximum negative pressure P1 in the first strong suction operation.

  Further, when the maximum negative pressure P2 in the second strong suction is made smaller than the maximum negative pressure P1 in the first strong suction, it is particularly advantageous when the distance between the upstream pressure chamber 46 and the downstream upper filter chamber 64 is short. . When the space between the upstream pressure chamber 46 and the downstream upper filter chamber 64 is short, when the blockage between the upstream pressure chamber 46 and the downstream upper filter chamber 64 is released by the second strong suction, There is a possibility that the maximum negative pressure P2 does not sufficiently attenuate and reaches the pressure chamber 46 on the upstream side. However, if the maximum negative pressure P2 in the second strong suction is made smaller than the maximum negative pressure P1 in the first strong suction, the negative pressure increased more reliably to the maximum negative pressure P2 can be increased. Can be lost before reaching

  Further, according to the present embodiment, in the first strong suction operation, the pressure on the upstream side is blocked by closing the ink cartridges 22a to 22d (liquid containers) with respect to the upstream pressure chamber 46 (widening portion). Since the negative pressure in the chamber 46 (the widened portion) can be increased, the bubbles (air layer) in the pressure chamber 46 can be efficiently discharged and filled with liquid.

In the present embodiment, since the first strong suction operation and the second strong suction operation are performed in the initial filling, the liquid can be efficiently melted at the time without discharging a large amount of liquid. (Second Embodiment)
Next, a second embodiment will be described with reference to FIG. In the second embodiment, since the first hardware configuration is the same, the same components are denoted by the same reference numerals, and the description thereof is omitted. In the second embodiment, the second strong suction operation is different.

  That is, in the first strong suction operation, the control unit 41 controls at the same pump suction speed V1 as that for the suction pump 23 in the first strong suction operation of the first embodiment. That is, the suction pump 23 is continuously driven. In contrast, the control unit 41 continuously drives and controls the pump suction speed V2 (<V1), which is slower than that in the first strong suction operation, in the second strong suction operation.

  The pump suction speed V2 is the choke valves 30a, 70a in the second strong suction operation, where t1 is the time from the closed state of the choke valves 30a, 70a to the opening (valve closing time). When the time t2 from the closed state to the open time reaches the same time as t1, the maximum negative pressure P2 described in the first embodiment is set.

  Note that it is only necessary that the space 61 in the cap 26 has the maximum negative pressure P2, so that it is not always necessary to satisfy t1 = t2. For example, if the condition that the pump suction speed V2 is slower than the pump suction speed V1 is satisfied, t1> t2 or t1 <t2 may be satisfied. In this case, when the space 61 in the cap 26 reaches the maximum negative pressure P2 by the detection of the pressure sensor 85, the control unit 41 controls the ink supply pressure so as to open the choke valve 30a.

  Thus, in the second embodiment, in the second strong suction operation, the pump suction speed V2 of the suction pump 23 is set to be higher than the pump suction speed V1 of the second strong suction operation. By slowing down, the maximum negative pressure P2 in the second strong suction operation can be made smaller than the maximum negative pressure P1 in the first strong suction operation.

In addition, you may change embodiment of this invention as follows.
In the second embodiment, in the second strong suction operation, the suction pump 23 is continuously driven, so that the pump suction speed is slower than that in the first strong suction operation. Instead, in the second strong suction operation, the suction pump 23 may be intermittently driven to obtain the maximum negative pressure P2 (<P1).

  If the maximum negative pressure P2 of the second strong suction operation can be made smaller than the maximum negative pressure P1 of the first strong suction operation by the intermittent operation of the suction pump 23, the first and second strong suction operations are performed. In any case, the suction speeds of the suction pumps 23 are not necessarily the same and may be different. In short, in the second strong suction operation, the maximum negative pressure P2 only needs to be smaller in the second suction step than in the first suction step.

  ○ Instead of the configuration of the choke valve 30a of each of the above embodiments, the supply pipe 18a between the pressure adjusting mechanism 17a and the ink cartridges 22a to 22d is formed of an elastic material, and the supply pipe 18a is abutted from the outside. Further, a stop member 100 as an opening / closing means capable of releasing contact may be provided (see FIGS. 9A and 9B). The stop member 100 comes into contact with the supply pipe 18a and is released from being closed or released by, for example, advancing / retreating drive of a drive source S composed of a solenoid or the like.

  In addition, the control unit 41 controls the drive source S at the same timing as the operation timing of the choke valve 30a of the first embodiment or the second embodiment to block a part of the supply pipe 18a or release the blockage. Then, by allowing the ink to flow in the supply pipe 18a, it is possible to obtain the same operational effects as those in the first embodiment or the second embodiment.

  In the first and second embodiments, after performing the first strong suction operation, the second strong suction operation and the normal suction operation in which suction is performed by the suction pump 23 with the supply channel K opened ( In the normal suction step), at least the second strong suction operation may be performed. For example, the normal suction operation may be performed before or after the second strong suction operation.

  Even in this case, even if the normal suction operation is performed either before or after the second strong suction operation, it is trapped in the upper filter chamber 64 (the widened portion) on the downstream side by the second strong suction operation. The amount of air bubbles can be reduced. As a result, the liquid can be efficiently filled without discharging a large amount of liquid.

  In the first embodiment, at the time of initial filling, after the normal suction operation, the first strong suction operation and the second strong suction operation are performed without taking time. However, the method is not limited to this method. After the initial filling described in the first embodiment (including the normal suction operation, the first and second strong suction operations), at regular intervals or irregularly. The first strong suction operation and the second strong suction operation may be executed after a certain time.

  That is, the control unit 41 is provided with time tables for the first and second strong suction operations, and after the initial filling is completed based on the time tables, the first and second are taken. Perform powerful suction operation. In the time table, after completion of the initial filling, data of intervals for executing the first and second strong suction operations (for example, a time schedule executed every month or every irregular interval) is stored. It is listed. The time table may be configured to be rewritable from the outside so that it can be arbitrarily changed. If the timetable is rewritable, the interval can be varied, so that the ink filling method can be used according to the use environment of the apparatus.

  Further, in this case, after the initial filling, during the interval, the air bubbles carried from the ink cartridge 22a to the upstream pressure chamber 46 are trapped or the gas dissolved in the liquid is turned into the air bubbles. In some cases, the amount of bubbles increases due to trapping. Even in such a case, since the first strong suction operation and the second strong suction operation are executed at intervals, the liquid can be efficiently filled without discharging a large amount of liquid. .

  In the first and second embodiments, after the first strong suction operation, the second strong suction operation is performed without taking time, that is, in a series. After the operation, the second strong suction operation may be performed after a time (interval).

  For example, the control unit 41 includes time tables for the first and second strong suction operations, and after the first strong suction operation is completed, the first strong suction operation is performed based on the time table. After ending, the second strong suction operation is performed after an interval. In the time table, after the completion of the first strong suction operation, data of an interval for executing the second strong suction operation (for example, a time schedule executed every month or every indefinite interval). ). The time table may be configured to be rewritable from the outside so that it can be arbitrarily changed. If the timetable is rewritable, the interval can be varied, so that the ink filling method can be used according to the use environment of the apparatus.

  Even if executed in this way, in the second strong suction operation, the upstream upper filter chamber 64 (widened portion) is not exhausted and compensated for from the upstream pressure chamber 46 (widened portion), The amount of bubbles trapped in the downstream upper filter chamber 64 (widened portion) can be reduced. As a result, the liquid can be efficiently filled without discharging a large amount of liquid.

In the first and second embodiments, the initial filling is performed by the normal suction operation and the first and second strong suction operations, but the initial filling is not limited to these combinations.
For example, the initial filling may be performed by a combination of the first strong suction operation and a normal suction step in which suction is performed by the suction pump 23 with the supply flow path K being opened. Here, the combination means that the order of the first strong suction operation and the normal suction operation does not matter, and either of them may be executed by the control unit 41 first.

  As described above, since the first strong suction operation is performed by performing the first strong suction operation and the normal suction operation (normal suction step) during the initial filling, the first strong suction operation is performed. When the maximum negative pressure P1 acts, bubbles that have been trapped in the upstream pressure chamber 46 (widened portion) but could not be held can be discharged. Thereafter, the control unit 41 performs the second strong suction operation at intervals.

  ○ After the initial filling of the first embodiment or the second embodiment, the normal suction step of performing the second strong suction or suction by the suction pump 23 with the supply channel K opened at intervals. May be performed.

  As described above, after the initial filling in the first embodiment or the second embodiment, if an interval is set, air bubbles carried from the ink cartridge 22a to the pressure chamber 46 on the upstream side are trapped in the interval or the ink is discharged. In some cases, the gas dissolved in the gas becomes bubbles and trapped, increasing the amount of bubbles. Even in such a case, when the second strong suction is executed at intervals after the completion of the initial filling, the bubbles trapped in the upper filter chamber 64 on the downstream side can be discharged. When the normal suction step is executed at intervals after the completion of the initial filling, bubbles trapped in the upstream and downstream pressure chambers 46 and the upper filter chamber 64 can be discharged.

  In each of the above embodiments, the pressure adjustment mechanism 17a is configured as a self-sealing valve, but is not limited to a self-sealing valve, and may be configured as a pressure damper described in Patent Document 1.

1 is a schematic plan view of a liquid ejection device according to a first embodiment. FIG. 3 is a schematic diagram illustrating a schematic configuration of a supply system and a waste liquid system in a printer. (A), (b) is sectional drawing which shows schematic structure of the choke valve 30a. Sectional drawing of a pressure adjustment mechanism. Sectional drawing of a filter unit. FIG. 3 is a schematic diagram illustrating a schematic configuration of a supply system and a waste liquid system in a printer. Explanatory drawing which shows the internal pressure change of the cap 26 of a 1st and 2nd strong suction operation | movement, and the timing of the drive of a suction pump. Explanatory drawing which shows the internal pressure change of the cap 26 of the 1st and 2nd strong suction operation | movement of 2nd Embodiment, and the timing of the drive of a suction pump. (A), (b) is a schematic diagram of the stop member 100 of other embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Printer (liquid discharge apparatus), 17a ... Pressure adjustment mechanism, 22a-22d ... Ink cartridge (liquid container), 23 ... Suction pump (suction means), 26 ... Cap, 29 ... Waste liquid tube (with suction pump, cap 26) Constituting a suction means), 30a ... choke valve (first opening / closing means), 33 ... nozzle, 41 ... control section (control means), 46 ... pressure chamber (upstream widening section), 64 ... upper filter chamber (downstream) Side widened portion), 70a ... choke valve (second opening / closing means), K ... supply flow path, P1 ... maximum negative pressure (first maximum negative pressure), P2 ... maximum negative pressure (second maximum negative pressure) )

Claims (11)

A supply flow path for supplying the liquid to a nozzle for discharging the liquid from a liquid container for storing the liquid;
The supply flow path has a tubular flow path, and a pair of widened portions that are in communication with the tubular flow path and positioned on the upstream side and the downstream side, respectively.
In the liquid filling method of the supply flow path in the liquid discharge apparatus including the suction means for sucking the gas or liquid in the supply flow path from the nozzle,
In the state where the supply channel between the liquid container and the upstream widened portion is closed, suction is performed by the suction means, the closed state is released, and the air bubbles trapped in the upstream widened portion are removed. A first suction step for discharging from the widened portion;
After the first suction step, the suction means performs suction while the supply channel between the upstream widened portion and the downstream widened portion is closed, and then the closed state is released. And a second suction step for discharging bubbles trapped in the widened portion on the downstream side.   2. The first suction step and the second suction step are performed as initial filling for filling a supply channel with liquid from a liquid container so that a user can use the liquid ejection device for the first time. The filling method described in 1.   3. The second suction step or a normal suction step of performing suction by the suction means in an opened state with an interval after the initial filling. 3. Filling method.   Since the user uses the liquid discharge device for the first time, as the initial filling for filling the supply channel with the liquid from the liquid container, the suction by the suction means is performed with the supply channel opened. 2. The filling method according to claim 1, wherein at least a first suction step is performed among the normal suction steps to be performed, and a second suction step is performed at intervals.   5. The suction device according to claim 1, wherein suction of the suction means is performed so that the maximum negative pressure is smaller in the second suction step than in the first suction step. 6. Filling method.   In the second suction step, the maximum negative pressure that is smaller than the maximum negative pressure of the first suction step is set by shortening the duration of the state in which a part of the supply flow path is closed as compared with the first suction step. The filling method according to claim 5, wherein:   In the second suction step, the suction speed of the suction means is made slower than the suction speed of the suction means of the first suction step, so that the maximum negative pressure is smaller than the maximum negative pressure of the first suction step. The filling method according to claim 5.   6. The filling method according to claim 5, wherein in the second suction step, the suction means is intermittently operated to obtain a maximum negative pressure smaller than the maximum negative pressure of the first suction step.   After performing the first suction step, at least the second suction step is performed among the second suction step and the normal suction step in which suction is performed by the suction means in a state where the supply channel is opened. The filling method according to claim 1.   Since the user uses the liquid ejection device for the first time, the first suction step and the second suction step are executed at intervals after the initial filling of the supply channel from the liquid container. The filling method according to claim 1. A supply flow path for supplying the liquid from a liquid container for storing the liquid to a nozzle for discharging the liquid, the supply flow path being in communication with the tubular flow path and the tubular flow path; Having a pair of widened portions respectively located on the downstream side;
First opening / closing means for opening / closing a supply flow path between the liquid container and the upstream widened portion;
A second opening / closing means for opening / closing a supply channel between the pair of widened portions;
Suction means for sucking gas or liquid in the supply flow path from the nozzle;
Control means for controlling the first and second opening / closing means and the suction means;
The control means controls the first opening / closing means to close the supply flow path between the liquid container and the upstream widening section, and controls the suction means to execute suction. Controlling the first opening and closing means to release the closed state;
Thereafter, the control means controls the second opening / closing means to close the supply flow path between the pair of widened portions, and controls the suction means to perform suction, and then performs the suction. 2. A liquid ejecting apparatus according to claim 1, wherein the closed state is released by controlling two opening / closing means.

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