JP2009039873A - Suction control method, and liquid jet apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suction control method in which improvement of the discharging efficiency of bubbles at the time of cleaning control can be attained, and to provide a liquid jet apparatus. <P>SOLUTION: A control part starts the suction action by operating a pump in a sealing state of a cap member to a nozzle formation surface of a recording head (liquid jet head) and in the state that an atmosphere open valve is closed. The suction process of one cycle consists of a pressure reduction process (S3), a maintaining process (S4), and a return process (S5). The suction process is intermittently repeated by a plurality of cycles. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a suction control method for forcibly sucking liquid and bubbles in a liquid ejecting head, and a liquid ejecting apparatus.

  A typical example of a liquid ejecting apparatus that includes an ejecting head capable of ejecting (discharging) liquid and ejecting various liquids from the ejecting head is, for example, for recording paper as an ejected object (recording medium) An image recording apparatus such as an ink jet recording apparatus (hereinafter referred to as a printer) that performs recording by ejecting and landing ink. In recent years, it is applied not only to this image recording apparatus but also to various manufacturing apparatuses. For example, in a display manufacturing apparatus such as a liquid crystal display, a plasma display, an organic EL (Electro Luminescence) display, or an FED (surface emitting display), various liquid materials such as coloring materials and electrodes are used for pixel formation regions and electrode formation. A liquid ejecting apparatus is used for ejecting an area or the like.

  In an ink jet recording head (hereinafter referred to as a recording head) as a liquid ejecting head mounted on the printer, ink stored in an ink cartridge as a liquid supply source is introduced into a pressure generating chamber and ejected from a nozzle opening. It is configured. In this configuration, it is ideal that the ink flow path (liquid flow path) from the ink cartridge to the nozzle opening of the recording head is filled with only ink, but the structure completely prevents the intrusion of bubbles. It is difficult. For example, when an ink cartridge is replaced, air bubbles enter the ink channel from the connection between the ink cartridge and the recording head when performing an initial filling process for filling the ink channel of the ink cartridge into the ink channel of the recording head. There is. Further, air bubbles may be generated by permeating (gas exchange) the wall surface of the structure of the recording head and external air being dissolved in the ink in the ink flow path. Bubbles in the ink flow path gradually grow and become large, and when the excessively grown bubbles move to the pressure generating chamber side due to the flow of ink, pressure loss due to absorption of pressure fluctuations during ink ejection, There is a possibility of causing problems such as insufficient supply of ink due to air bubbles blocking the flow path.

In order to prevent such problems due to air bubbles, this type of printer periodically executes cleaning control that generates an ink flow several times the flow rate during normal recording operation, Bubbles are discharged (for example, Patent Document 1).
JP 2001-105629 A

  However, even if the cleaning control described above is performed, it is difficult to remove bubbles staying in the flow path, particularly bubbles staying in the corners of the pressure generating chamber. When the suction force is increased, there is a problem that the ink is wasted.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a suction control method and a liquid ejecting apparatus capable of improving the discharge performance of bubbles during cleaning control. It is in.

A suction control method of the present invention has been proposed to achieve the above object, and is a suction control method for performing suction through a nozzle opening with respect to a liquid ejecting head that ejects liquid from the nozzle opening,
The suction step of performing suction by reducing the flow path in the liquid ejecting head is intermittently performed a plurality of times.

  In the above-described configuration, it is desirable that the suction step includes a pressure reducing step for reducing the flow path in the liquid ejecting head and a returning step for returning the pressure reduced flow path to the positive pressure side.

  According to the above configuration, it is possible to facilitate the movement of bubbles staying in the flow path by intermittently performing the suction step of performing suction by depressurizing the flow path in the liquid ejecting head. Thus, the bubble discharge efficiency can be improved. That is, by intermittently performing the suction process a plurality of times, the bubbles staying in the flow path repeatedly expand and contract, thereby making it possible to easily separate and discharge the air bubbles from the inner wall surface of the flow path. Become. As a result, it is possible to efficiently discharge bubbles with a smaller amount of suction than before, and it is possible to suppress liquid consumption.

Moreover, in the said structure, it is desirable to perform the maintenance process which maintains the pressure reduction state by a pressure reduction process between the said pressure reduction process and the said reset process.
Furthermore, in this configuration, it is desirable that the maintaining step is executed only for a time obtained by dividing the distance from the negative pressure generation source that generates a negative pressure for performing suction to the bubble retention location by the speed of sound.

  According to the above configuration, by performing only the time obtained by dividing the distance from the negative pressure generation source to the bubble retention point by the speed of sound in the maintenance step between the decompression step and the return step, It becomes possible to apply a pressure fluctuation efficiently.

  In the above configuration, it is desirable that the suction step is repeated at intervals corresponding to the natural period of the bubbles. Thereby, the pressure fluctuation by the suction control and the expansion and contraction of the bubbles can be resonated, thereby making it easier to move the bubbles. As a result, the bubble discharge efficiency can be further improved.

The liquid ejecting apparatus of the present invention is a liquid ejecting apparatus including a liquid ejecting head that ejects liquid from a nozzle opening, and a suction control unit that performs suction through the nozzle opening with a negative pressure from a negative pressure generation source. ,
The suction control means intermittently performs a suction process in which suction is performed by depressurizing a flow path in the liquid jet head a plurality of times.

  In the above-described configuration, it is desirable that the suction step includes a pressure reducing step for reducing the flow path in the liquid ejecting head and a returning step for returning the pressure reduced flow path to the positive pressure side.

  According to the above configuration, it is possible to easily move the bubbles staying in the flow path by intermittently performing the suction step of performing suction by depressurizing the flow path in the liquid ejecting head. Thus, the bubble discharge efficiency can be improved. That is, by intermittently performing the suction process a plurality of times, the bubbles staying in the flow path repeatedly expand and contract, thereby making it possible to easily separate and discharge the air bubbles from the inner wall surface of the flow path. Become. As a result, it is possible to efficiently discharge bubbles with a smaller amount of suction than before, and it is possible to suppress liquid consumption.

In the above-described configuration, it is preferable that the suction control unit executes a maintenance step of maintaining a reduced pressure state by the pressure reduction step between the pressure reduction step and the return step.
Further, in this configuration, the suction control means executes the maintaining step for a time obtained by dividing the distance from the negative pressure generating source that generates the negative pressure for performing suction to the bubble retention location by the speed of sound. It is desirable to do.

  According to the above configuration, by performing only the time obtained by dividing the distance from the negative pressure generation source to the bubble retention point by the speed of sound in the maintenance step between the decompression step and the return step, It becomes possible to apply a pressure fluctuation efficiently.

  In the above configuration, it is preferable that the suction control unit repeats the suction process at an interval corresponding to a natural period of bubbles. Thereby, the pressure fluctuation by the suction control and the expansion and contraction of the bubbles can be resonated, thereby making it easier to move the bubbles. As a result, the bubble discharge efficiency can be further improved.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. Note that, in the embodiments described below, various limitations are made as preferred specific examples of the present invention. However, the scope of the present invention is limited to these embodiments unless otherwise specified in the following description. It is not limited to. In the following description, an ink jet recording apparatus (printer) is taken as an example of the liquid ejecting apparatus of the invention.

  FIG. 1 is a perspective view illustrating the basic configuration of the printer 1. As shown in FIG. 1, a printer 1 has a carriage 3 attached to a guide shaft 2, and a recording head 4 (a kind of liquid ejecting head of the present invention) is attached to the lower surface thereof. Further, inside the carriage 3 is provided a cartridge holder portion (not shown) for detachably holding the ink cartridge. The carriage 3 is connected to a timing belt 8 that is stretched between a drive pulley 6 and an idle pulley 7 that are joined to a rotation shaft of a carriage motor (pulse motor) 5. By driving, the recording paper 9 moves in the width direction (main scanning direction).

  The ink cartridge is a storage member (a type of liquid storage source) that stores ink (a type of liquid of the present invention). This ink is obtained by dissolving or dispersing a color material in an ink solvent. For example, a pigment or a dye is used as the color material, and water is used as the ink solvent. When the ink cartridge is mounted on the cartridge holder portion, an ink supply needle (not shown) provided on the cartridge holder portion is inserted into the ink cartridge. Since the ink supply needle communicates with the ink supply path 10 (see FIG. 3) of the recording head 4, the ink in the ink cartridge can be supplied into the recording head 4 when the ink supply needle is inserted. Become. Then, in order to fill the ink in the ink cartridge into the flow path in the recording head 4, initial filling described later is performed. As the ink cartridge, a type that is disposed on the printer main body (housing) side and is supplied to the recording head 4 through an ink supply tube can be adopted.

  A platen 11 is provided below the guide shaft 2. The platen 11 is a plate-like member that supports the recording paper 9 from below. The platen 11 is provided with a liquid absorbing member 12 such as a sponge. In addition, a paper feed roller 13 is disposed in parallel with the guide shaft 2 on the upstream side of the liquid suction member 12. The paper feed roller 13 is rotated by a driving force from a paper feed motor 14 (stepping motor or DC motor) when the recording paper 9 is conveyed.

  A home position is set at a position within the movement range of the carriage 3 and outside the platen 11. The recording head 4 is positioned at the home position in the standby state. At this home position, a wiper mechanism 15 for wiping the nozzle forming surface of the recording head 4 and a capping mechanism 16 capable of sealing the nozzle forming surface in a non-recording state are arranged side by side along the guide shaft 2. Has been.

  Next, the recording head 4 will be described. As shown in FIG. 3, the recording head 4 is schematically composed of a case 23, a flow path unit 24, and a vibrator unit 25. The case 23 is a synthetic resin block-like member provided therein with an accommodation cavity 27 whose both front and rear ends are open, and a flow path unit 24 is joined to the front end surface. Further, in the accommodation space 27, the transducer unit 25 is accommodated in a state where the tip of each piezoelectric transducer 28 faces the opening on the distal end side. Further, an ink supply path 10 that communicates between the ink supply needle and the flow path unit 24 is provided on the side of the accommodation space 27.

  The flow path unit 24 includes a flow path forming plate 29, a nozzle plate 30, and an elastic plate 31. The nozzle plate 30 is a thin plate-like member in which a large number (for example, 360) of nozzle openings 32 are formed in a row at a pitch corresponding to the dot formation density, and is constituted by, for example, a stainless steel plate. A nozzle row (nozzle group) is constituted by the nozzle openings 32 provided in this row, and a plurality of nozzle rows are formed side by side. The outer surface of the nozzle plate 30 becomes a nozzle forming surface. In the flow path forming plate 29, a reservoir 33 (common liquid chamber) into which ink supplied through the ink supply path 10 flows, and pressure generation for generating ink pressure necessary for ejecting ink from the nozzle openings 32 are generated. A chamber 34, an ink supply port 35 that communicates with the reservoir 33 and the pressure generating chamber 34, and the like are formed. The pressure generation chambers 34 are empty spaces that are elongated in a direction substantially orthogonal to the nozzle row direction, and are formed in a number corresponding to the nozzle openings 32 in the nozzle row direction. The elastic plate 31 has a double structure in which an elastic film is laminated on a support plate.

  In this flow path unit 24, a series of ink flow paths are formed from the ink supply path 10 to the nozzle opening 32 through the reservoir 33, the ink supply port 35, the pressure generation chamber 34, and the nozzle communication port 38. In this ink flow path, the portion from the ink supply port 35 to the nozzle communication port 38 constitutes an individual ink flow path provided for each nozzle opening 32.

  The vibrator unit 25 includes a vibrator group 36 including a plurality of piezoelectric vibrators 28 formed in a comb-like shape, and a fixing plate 37 to which a base end portion of the vibrator group 36 is joined. Yes. Each piezoelectric vibrator 28 constituting the vibrator group 36 is cut into an extremely thin width of about 50 μm to 100 μm, for example. Each piezoelectric vibrator 28 has a free end located outside the edge of the fixed plate 37 and is joined to the fixed plate 37 in a cantilever state. When the free end portion of the piezoelectric vibrator 28 is expanded and contracted in the element longitudinal direction, the diaphragm is pushed toward the pressure generation chamber 34 or pulled away from the pressure generation chamber 34. As a result, the volume of the pressure generation chamber 34 varies, and the ink pressure in the pressure generation chamber 34 changes. Ink (ink droplets) can be ejected from the nozzle openings 32 using this ink pressure.

  2, 4, and 5, the capping mechanism 16 moves the cap member 46 in a direction in which the cap member 46 moves closer to or away from the nozzle forming surface of the recording head 4. From a mechanism (not shown), a flexible drain tube 49 communicating between the sealing empty portion 45 and the drain tank 48, and a pump 50 disposed in the middle of the drain tube 49 Composed.

  The cap member 46 is a tray-like member having an open top surface having a bottom portion 51 and a side wall portion 52 rising from the periphery of the bottom portion 51. A space surrounded by the bottom portion 51 and the side wall portion 52 is sealed. Part 45. The cap member 46 is made of an elastic member such as rubber and is attached to a support member 53 made of synthetic resin or metal. In addition, a liquid absorbing member 54 is laid in the sealing void 45. The liquid absorbing member 54 is made of a liquid absorbing material such as felt or sponge that can absorb ink. A through hole is formed in the bottom of the cap member 46, and a drainage tube 49 is connected to the through hole in a liquid-tight state. Further, another through-opening is opened at the bottom of the cap member 46, and an air release tube 57 constituting an air release path is connected to the through-opening. An air release valve 58 is provided in the middle of the air release tube 57. That is, by opening and closing the atmosphere release valve 58, it is possible to switch between the sealed state of the sealing empty portion 45 and the atmosphere open state when the nozzle formation surface is sealed.

  The drainage tube 49 is a member constituting an ink discharge path. In the present embodiment, the drainage tube 49 is formed of a silicon tube having high chemical resistance and elasticity. A pump 50 (a negative pressure generation source in the present invention) provided in the middle of the drainage tube 49 constitutes a pump mechanism together with a drive motor. The pump mechanism in the present embodiment uses the paper feed motor 14 as a drive motor for driving the pump 50. That is, switching is performed between paper feeding and suction control by a clutch (not shown). As the drive motor, a dedicated motor for driving only the pump 50 may be provided separately.

  The pump mechanism is controlled by the controller 66 (see FIG. 7). That is, for example, when the paper feed motor 14 is configured by a stepping motor, the control unit 66 controls the rotation of the paper feed motor 14 by adjusting the number of drive pulses applied to the paper feed motor 14. The suction by the pump 50 is controlled. Therefore, the control unit 66 also functions as a suction control unit in the present invention.

  For example, as shown in FIG. 6A, the pump 50 in the present embodiment is crushed by sandwiching the drain tube 49 with the roller 55 and moving the roller 55 along the drain tube 49 in this state. In addition, a so-called ironing type tube pump that squeezes the air or liquid in the drainage tube 49 and sends it out. In the pump 50, the negative pressure can be applied to the sealed empty portion 45 by moving the roller 55 from the sealed empty portion 45 side to the drainage tank 48 side. When the pump 50 is operated, the ink stored in the sealing empty space 45 by the suction operation can be discharged to the drainage tank 48 side. The suction amount of the pump 50 is adjusted by controlling the rotation amount of the paper feed motor 14, that is, the rotation amount of the pump 50. In the following description, an operation of applying a negative pressure to the sealing empty portion 45 with the nozzle forming surface sealed is referred to as a forward rotation operation, and an operation of moving the roller 55 in the opposite direction is referred to as a reverse rotation operation.

  In the present embodiment, the rotation direction can be changed by controlling the paper feed motor 14. That is, the moving direction of the roller 55 can be changed. In addition, as shown in FIG. 6B, when the suction is not performed, the roller 55 moves along the drainage tube 49 through the guide groove 56 to the rotating shaft side of the pump 50 by performing a reverse operation. Control is performed to release the pressure from 55 to the drainage tube 49. In the printer 1 according to the present invention, this reverse operation is performed every time after the suction control is completed, for example. The pump 50 is not limited to the illustrated tube pump, and may be constituted by other pumps such as a gear pump that sends the drainage to the downstream side by rotating the drive gear and the driven gear.

  In the sealed state in which the nozzle forming surface of the recording head 4 is sealed by the cap member 46, the nozzle opening 32 of the nozzle forming surface faces the sealing void 45, and the tip of the cap member 46, the nozzle forming surface, Adheres in a liquid-tight state (see FIG. 5). When the pump 50 is operated in this sealed state and the atmosphere release valve 58 is closed, the inside of the sealing empty portion 45 is depressurized, so that the ink in the recording head 4 is sucked through the nozzle openings 32. , Can be discharged outside the head. Using this, when the ink cartridge is mounted, the initial filling for filling the ink flow path of the recording head 4 with the ink in the ink cartridge and the cleaning for removing the thickened ink and bubbles in the ink flow path are performed. This suction control is performed in the processing.

  Next, the electrical configuration of the printer 1 will be described. As illustrated in FIG. 7, the illustrated printer 1 includes a printer controller 60 and a print engine 61. The printer controller 60 stores an interface 62 (external I / F 62) that receives print data from a host computer (not shown), a RAM 63 that stores various data, a control routine for various data processing, and the like. A ROM 66, a control unit 66 comprising a CPU, a drive signal generating circuit 67 capable of generating a drive signal to be supplied to the recording head 4, an oscillation circuit 68 for generating a clock signal, a drive signal for recording operation, and a maintenance operation An interface 69 (internal I / F 69) for transmitting a control signal and the like to the print engine 61 is provided. These units are electrically connected to each other via an internal bus. The print engine 61 includes a carriage motor (pulse motor) 5 that moves the carriage 3, a paper feed motor 14 that rotates the paper feed roller 13, a recording head 4 (electric drive system), and the like.

  The control unit 66 is a part that performs various controls in the printer 1 and controls each part of the print engine 61. For example, in the control of the recording operation, dot pattern data is generated based on print data from a host computer (not shown), and the generated dot pattern data is transferred to the recording head 4. Further, the carriage motor 5 is operated to move the carriage 3 (that is, the recording head 4), and the paper feed motor 14 is operated to transport the recording paper 9. Further, the suction by the pump (tube pump) 50 is controlled by operating the paper feed motor 14 during initial filling and cleaning.

Next, suction control during initial filling and cleaning in the above configuration will be described.
Here, at the time of initial filling or cleaning, it is desirable to prevent bubbles from remaining in the ink flow path as much as possible. However, it is difficult to completely eliminate bubbles in the ink flow path simply by performing suction control. In particular, when bubbles remain in the corners of the empty space such as the pressure generation chamber 34, it is difficult to cause the ink flow during suction to act on the bubbles with normal suction, and it is difficult to separate the bubbles from the corners. It was. Therefore, in the suction control method according to the present invention, by devising the pressure change at the time of suction control, it is easy to discharge the bubbles that have been difficult to eliminate in the past, and the bubble discharge efficiency is improved.

FIG. 8 is a flowchart showing the flow of suction control.
First, the control unit 66 controls the carriage motor 5 to move the carriage 3 to the home position, and capping the nozzle formation surface of the recording head 4 by the capping mechanism 16 (S1). At this time, by closing the air release valve 58, the inside of the sealing empty portion 45 in the capped state is switched to a sealed state (liquid-tight / air-tight state).

  Subsequently, the control unit 66 applies a driving pulse to the paper feed motor 14 to start driving the pump 50, and starts a suction operation (S2). The suction control according to the present invention is characterized in that the suction process in which the ink flow path in the recording head 4 is decompressed and sucked is intermittently repeated a plurality of times. The one-cycle suction process includes a pressure reduction process (S3), a maintenance process (S4), and a return process (S5). In this embodiment, the suction process is set to be performed in three cycles. FIG. 9 is a pressure waveform showing a pressure change in the sealing void 45 in the suction process. This pressure waveform indicates that the negative pressure increases toward the bottom.

  In the pressure reducing step (S3), the inside of the sealing empty portion 45 is gradually moved by operating (forward rotation) the pump 50 with the cap member 46 sealed with respect to the nozzle formation surface and with the atmosphere release valve 58 closed. For example, the pressure is reduced to tens of kPa. As a result, the inside of the ink flow of the recording head 4 is depressurized, and the ink and bubbles in the ink flow path are discharged from the nozzle opening 32 into the sealing void 45. As shown in FIG. 9, the internal pressure of the sealing void 45 at this time changes in a quadratic curve toward the negative pressure side. The pressure change at this time acts on bubbles staying in the ink flow path. Thereby, for example, the bubble B (FIG. 10A) convection in the corner of the pressure generating chamber 34 expands as the ink flow path is depressurized (FIG. 10B). As shown in FIGS. 10A and 10B, the direction in which the center of gravity of the bubble B is separated from the wall surface of the ink flow path (pressure generation chamber 34) with respect to the position of the center of gravity before expansion as a result of this expansion. Move to.

  If the pressure is reduced to the maximum in the pressure reduction step, the pressure reduction state in the pressure reduction step is maintained for a predetermined time in the maintenance step (S4). Specifically, the duration of the maintenance step is calculated by dividing the distance D from the pump 50, which is a negative pressure generation source, to the bubble retention location (the pressure generation chamber 34 in this embodiment) by the speed of sound c in the ink. The time obtained is set. Thereby, it becomes possible to propagate a pressure fluctuation more efficiently to the bubbles. That is, the pressure fluctuation can be more reliably applied to the bubble B by maintaining the pressure-reduced state only for the time when the pressure fluctuation generated by the pump 50 which is a negative pressure generation source reaches the pressure generation chamber 34. .

  After the maintenance step (S4), subsequently, the return step (S5) is performed. In this return process, the control unit 66 stops the operation of the pump 50 and opens the atmosphere release valve 58 to return from the state where the pressure is reduced to the maximum to the positive pressure (atmospheric pressure) side. Thereby, the suction from the nozzle opening 32 is stopped. And as shown in FIG.10 (c), the bubble B which is convection to the corner part of the pressure generation chamber 34 shrinks with a pressure change. Since the pressure change at this time acts evenly on the surface of the bubble B, the bubble B contracts without greatly deviating from the position of the center of gravity during expansion. Thereby, the bubble B can be separated from the wall surface of the ink flow path (pressure generation chamber 34).

  In this way, one cycle of the suction process is executed. If the suction process of one cycle has been executed, the control unit 66 determines whether or not the suction process has been executed for three cycles (S6). (S3 to S5) are repeated. In this way, the suction process is intermittently repeated a plurality of times so that the bubbles in the ink channel repeatedly expand and contract, and the bubbles are separated from the inner wall surface of the ink channel and discharged by this expansion and contraction. It becomes possible to make it easy. As a result, the bubbles can be efficiently discharged with a smaller amount of suction than before, and as a result, the consumption of ink can be suppressed.

  Here, in the present embodiment, the above suction process is repeated at an interval Tb corresponding to the natural period of the bubble B. Thereby, the pressure fluctuation by the suction control and the volume change (expansion / contraction) of the bubble can be resonated, and the bubble B can be moved more easily. As a result, the bubble discharge efficiency can be further improved.

  If the suction process is executed for three cycles, the controller 66 stops the suction control (S7). That is, the cap member 46 is separated from the nozzle forming surface in a state where the operation of the pump 50 is stopped and the air release valve 58 is opened. After that, the nozzle forming surface is wiped by the wiper mechanism 15 (S8), and the ink adhering to the nozzle forming surface is wiped off. When the wiping is finished, a series of suction control is finished. The wiping process may be performed every cycle of the suction process.

In the above embodiment, the example in which the number of repetitions of the suction process is set to 3 has been described, but the present invention is not limited to this. The number of repetitions can be set to any number as long as it is at least once.
Moreover, although the example which set the distance D from the pump 50 to the pressure generation chamber 34 as a distance from a negative pressure generation source to a bubble retention location was shown, it is not restricted to this, A bubble stays especially from a negative pressure generation source. It is possible to arbitrarily set the distance to the location where it is easy to do.

  In the above description, the ink jet printer 1 which is a kind of liquid ejecting apparatus has been described as an example. However, the present invention can also be applied to other liquid ejecting apparatuses in which residual bubbles are a problem. For example, a display manufacturing apparatus that manufactures color filters such as liquid crystal displays, an electrode manufacturing apparatus that forms electrodes such as organic EL (Electro Luminescence) displays and FEDs (surface emitting displays), and chips that manufacture biochips (biochemical elements) The present invention can also be applied to a manufacturing apparatus and a micropipette that supplies an accurate amount of a very small amount of sample solution.

FIG. 2 is a perspective view illustrating a configuration of a printer. It is a schematic diagram explaining the structure of a carriage, a capping mechanism, and a pump mechanism. FIG. 3 is a partial cross-sectional view of a recording head. It is a perspective view explaining a cap member. It is a schematic diagram explaining the sealing state of a capping mechanism. It is explanatory drawing of a pump, (a) is explanatory drawing of forward rotation operation | movement, (b) is explanatory drawing of reverse rotation operation | movement. 2 is a block diagram illustrating an electrical configuration of a printer. FIG. It is a flowchart explaining the flow of suction control. It is a pressure waveform which shows the pressure change in a sealing empty part. (A)-(c) is a schematic diagram explaining the motion of the bubble in an ink flow path at the time of suction control.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printer, 3 ... Carriage, 4 ... Recording head, 14 ... Paper feed motor, 16 ... Capping mechanism, 24 ... Channel unit, 25 ... Vibrator unit, 30 ... Nozzle plate, 32 ... Nozzle opening, 33 ... Reservoir, 34 ... Pressure generating chamber, 45 ... Sealing empty part, 46 ... Cap member, 48 ... Drainage tank, 49 ... Drainage tube, 50 ... Pump, 51 ... Bottom part, 52 ... Side wall part, 53 ... Support member, 54 ... Liquid-absorbing member, 57 ... Air release tube, 58 ... Air release valve, 60 ... Printer controller, 61 ... Print engine, 66 ... Control unit

Claims (10)

A suction control method for performing suction through a nozzle opening to a liquid ejecting head that ejects liquid from the nozzle opening,
A liquid ejecting head suction control method, wherein a suction step in which suction is performed by depressurizing a flow path in the liquid ejecting head is intermittently performed a plurality of times.   2. The suction control according to claim 1, wherein the suction step includes a pressure reducing step for reducing the pressure of the flow path in the liquid ejecting head and a return step for returning the pressure reduced flow path to the positive pressure side. Method.   The suction control method according to claim 2, wherein a maintenance step of maintaining a reduced pressure state by the pressure reduction step is executed between the pressure reduction step and the return step.   The said maintenance process is performed only for the time obtained by dividing | segmenting the distance from the negative pressure generation source which generate | occur | produces the negative pressure for performing suction | suction to a bubble retention location by a sound speed. Suction control method.   The suction control method according to any one of claims 1 to 4, wherein the suction step is repeated at an interval corresponding to a natural period of bubbles. A liquid ejecting apparatus comprising: a liquid ejecting head that ejects liquid from a nozzle opening; and a suction control unit that performs suction through the nozzle opening by a negative pressure from a negative pressure generation source,
The liquid ejecting apparatus according to claim 1, wherein the suction control unit intermittently performs a suction process of performing suction by depressurizing a flow path in the liquid ejecting head.   The liquid ejecting according to claim 6, wherein the suction step includes a decompression step of decompressing the flow path in the liquid ejecting head and a return process of returning the decompressed flow path to the positive pressure side. apparatus.   The liquid ejecting apparatus according to claim 7, wherein the suction control unit executes a maintenance step of maintaining a reduced pressure state in the pressure reduction step between the pressure reduction step and the return step.   9. The liquid ejecting apparatus according to claim 8, wherein the suction control unit performs the maintaining step for a time obtained by dividing a distance from the negative pressure generation source to a bubble retention point by a sound speed. . 10. The liquid ejecting apparatus according to claim 6, wherein the suction control unit repeats the suction step at an interval corresponding to a natural period of bubbles.

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