JP3495920B2 - Liquid discharge method, liquid discharge head, and liquid discharge device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid ejecting method and a liquid ejecting head and a liquid ejecting apparatus for ejecting a desired liquid by generating bubbles by applying heat energy to the liquid. The present invention relates to a liquid ejecting method, a liquid ejecting head, and a liquid ejecting apparatus that use a movable member that is displaced by utilizing generation.

The present invention also provides a printer for performing recording on a recording medium such as paper, thread, fiber, cloth, leather, metal, plastic, glass, wood and ceramics, a copying machine, a facsimile having a communication system, and a printer. The present invention can be applied to a device such as a word processor having a unit, and further to an industrial recording device that is combined with various processing devices.

In the present invention, "recording" means not only giving an image having a meaning such as characters and figures to a recording medium, but also giving an image having no meaning such as a pattern. Also means.

[0004]

2. Description of the Related Art By applying energy such as heat to ink, a state change accompanied by a sharp volume change (generation of bubbles) is caused in the ink, and the ink is ejected from an ejection port by an action force based on the state change. An ink jet recording method, which is a so-called bubble jet recording method, in which an image is formed by adhering this onto a recording medium is conventionally known. In a recording apparatus using this bubble jet recording method, as disclosed in US Pat. No. 4,723,129, an ejection port for ejecting ink and an ink flow communicating with this ejection port are disclosed. The channels and the electrothermal converters as energy generating means for ejecting the ink disposed in the ink flow paths are generally disposed.

According to such a recording method, it is possible to record a high-quality image at high speed and with low noise, and in the head performing this recording method, the ejection openings for ejecting ink are arranged at high density. Therefore, it has many excellent points that a high-resolution recorded image and a color image can be easily obtained with a small apparatus. Therefore, in recent years, this bubble jet recording method has been used in many office devices such as printers, copying machines, and facsimiles, and has also come to be used in industrial systems such as textile printing devices.

As the bubble jet technology has been used for products in various fields as described above, various requirements as described below have been further increased in recent years.

In order to obtain a high-quality image, driving conditions have been proposed for providing a liquid ejection method, etc., in which the ink ejection speed is fast and good ink ejection can be performed based on stable bubble generation, or high-speed recording is performed. From this point of view, there has been proposed a liquid flow head having an improved flow path shape in order to obtain a liquid discharge head having a high filling (refill) speed of the discharged liquid into the liquid flow path.

In addition to such a head, attention is paid to a back wave (pressure directed in the direction opposite to the direction toward the ejection port) generated with the generation of bubbles, and The invention of the structure for preventing is disclosed in JP-A-6-
No. 31918 (particularly FIG. 3). In the invention described in this publication, a triangular portion of a triangular plate member is opposed to a heater that generates bubbles. In the present invention, the back wave is temporarily and slightly suppressed by the plate member. However, since the correlation between the bubble growth and the triangular portion is not mentioned at all and there is no idea of it, the above invention includes the following problems.

That is, in the invention described in the above-mentioned publication, since the heater is located at the bottom of the recess and cannot establish a linear communication with the discharge port, the droplet shape cannot be stabilized, and the bubble growth is triangular. Since it is allowed around the top of the triangle, bubbles grow from one side of the triangular plate to the entire opposite side, and as a result, normal bubbles in the liquid as if the plate was not present. The growth of bubbles is completed. Therefore, the presence of the plate-shaped member has nothing to do with the grown bubbles. On the contrary, since the entire plate-shaped member is surrounded by bubbles, refilling the heater located in the recess causes turbulent flow during the bubble contraction stage, which causes the accumulation of minute bubbles in the recess, causing growth. The principle itself of discharging based on bubbles is disturbed.

On the other hand, EP publication EP436047A1
The invention alternately opens and closes a first valve that shuts off a portion near the discharge port and the bubble generating portion, and a second valve that shuts off the bubble generating portion and the ink supply portion completely. Are proposed (FIGS. 4-9 of EP436047A1). However, in the present invention, since these three chambers are divided into two, the ink that follows the droplets becomes a large trail at the time of ejection, and compared with the normal ejection method in which bubble growth, contraction, and defoaming are performed. Therefore, the satellite dots are considerably increased (it is presumed that the effect of meniscus receding due to defoaming cannot be used). Further, at the time of refilling, the liquid is supplied to the bubble generation part along with the defoaming, but since the liquid cannot be supplied to the area near the discharge port until the next foaming occurs, not only is there a large variation in the discharged droplets. , The ejection response frequency is extremely small, and is not at a practical level.

[0011]

An invention using a movable member (a plate-like member having a free end closer to the discharge port than a fulcrum) that can effectively contribute to the discharge of liquid droplets is completely different from the above-mentioned prior art. , Have been proposed by the applicant of the present application. Among the inventions, Japanese Patent Laid-Open No. 9-48127 discloses an invention in which the upper limit of the displacement of the movable member is regulated in order to prevent the behavior of the movable member described above from being slightly disturbed. Further, JP-A-9-323420 discloses that, with respect to the movable member,
Disclosed is an invention in which the position of the common liquid chamber in the upstream is shifted to the free end side of the movable member; In these cases, the assumption that the invention was created was that the growth of bubbles was temporarily wrapped in the movable member and then opened to the discharge port side at once, so that the entire bubbles are associated with individual elements involved in droplet formation. No attention has been paid to their correlation.

As the next step, the applicant of the present invention has disclosed that
-24588, as an invention (acoustic wave) focusing on bubble growth by pressure wave propagation as an element related to liquid ejection,
An invention is disclosed in which a part of the bubble generation region is released from the movable member. However, even in the present invention, since attention is paid only to the growth of bubbles at the time of ejecting the liquid, no attention is paid to the individual elements relating to the formation of the droplets themselves as a whole and their correlations.

Although it is known that the front portion (edge shooter type) of bubbles due to film boiling which has been conventionally known has a great influence on ejection, this portion can contribute to formation of ejected droplets more efficiently. Nothing has hitherto been paid attention to this, and the present inventors have conducted diligent research in order to clarify the technical aspects of the present invention.

The present invention is one of many inventions born from a more detailed analysis of the process from bubble generation to defoaming from the viewpoint of forming discharged droplets.
It has reached an extremely high level as compared with the conventional technical level that the printing quality peculiar to an inkjet is reduced, the satellites that stain the apparatus itself and the recording medium are reduced, and the stability of the image quality in continuous ejection operation is achieved.

The main objects of the present invention are as follows.

The first object of the present invention is to suppress the generated bubbles, the liquid on the discharge port side and the liquid on the supply side thereof by the movable member and the structure of the entire liquid flow path, and thereby a very novel liquid discharge principle. To provide.

A second object of the present invention is to provide a liquid ejecting method and a liquid ejecting head in which the satellites are reduced by suppressing the ejected droplet forming process and the satellites are completely eliminated in the ejecting operation.

A third object of the present invention is to reduce the load structure on the system of the recording apparatus for eliminating the adverse effects caused by the fluctuation of satellites and meniscus.

[0019]

In order to achieve the above-mentioned object, the present invention provides a liquid in a liquid flow path, in which the liquid is heated to generate bubbles in the liquid to grow. The one-end supported cantilever-shaped movable member is displaced from the initial state as the bubble grows, and the movable member substantially moves the upstream side of the liquid flow path before the bubble reaches the maximum volume. The liquid is ejected from the ejection port communicating with the downstream side of the liquid flow path by the pressure accompanying the growth of the air bubble, and after the liquid is ejected, the movable member is displaced along with the defoaming of the air bubble. In the liquid ejecting method for returning from the state to the initial state, when liquid is continuously ejected from the same liquid flow path, the vibration of the movable member returning from the displaced state after the previous liquid ejection is Before it completely converges, While the member is displaced in a direction toward the displacement state, characterized by starting the heating of the liquid for the next liquid discharge.

Further, it is preferable that a heating element is provided in the liquid flow path and the liquid is heated by driving the heating element. In this case, the heating element may be an electrothermal converter, and the liquid may be heated by supplying a drive pulse to the electrothermal converter.

In the liquid discharge head of the present invention, a heating element that heats the liquid in the liquid flow path to generate bubbles in the liquid, and a pressure that is connected to the downstream side of the liquid flow path and accompanies the growth of the bubbles. An ejection port through which the liquid is ejected, a movable member that is provided in a cantilever shape with one end supported in the liquid flow path, and has a free end located on the ejection port side, and the movable member that accompanies the growth of the bubbles. When it is displaced, it has a restricting portion that substantially contacts the movable member and substantially closes the upstream side of the liquid flow path, and a control means that controls the driving of the heating element. ,
When the liquid is continuously discharged from the same liquid flow path, before the vibration of the movable member returning from the displaced state after the previous liquid discharge is completely converged, It is characterized in that the heating element is driven for the next liquid discharge while being displaced in the direction toward the displacement state. Then, the movable member and the restriction portion substantially contact each other to substantially close the upstream side of the liquid flow path, thereby restricting the movement of the liquid in the upstream direction and the growth of the bubbles.

Further, the liquid ejecting apparatus of the present invention comprises the above-mentioned liquid ejecting head and a recording medium conveying means for conveying the recording medium receiving the liquid ejected from the liquid ejecting head. Then, recording is performed by ejecting ink from the liquid ejecting head and adhering the ink to the recording medium.

The terms "upstream" and "downstream" used in the description of the present invention refer to the liquid flow direction from the liquid supply source to the discharge port via the bubble generation region (or movable member).
Alternatively, it is expressed as an expression regarding this structural direction.

The "downstream side" with respect to the bubble itself means
It means a bubble generated in the downstream side with respect to the center of the bubble in the flow direction or the structural direction, or in the region downstream from the center of the area of the heating element. Similarly, the term "upstream side" regarding the bubble itself means a bubble generated in the upstream side with respect to the flow direction or the above structural direction with respect to the center of the bubble, or in the region upstream from the center of area of the heating element. To do.

Further, the "substantial contact" between the movable member and the regulating portion used in the present invention means that the movable member and the regulating portion are in a close state with a liquid of about several μm interposed therebetween or in a direct contact state. Good.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are sectional views of one embodiment of the liquid discharge head according to the present invention taken along the liquid flow path, and show characteristic phenomena in the liquid flow path as shown in FIGS. 2 (f) and FIG. 2 (a) to (e) are shown separately.

In the liquid ejection head of this embodiment, as the ejection energy generating element for ejecting the liquid, the heating element 2 for applying the heat energy to the liquid is provided on the smooth element substrate 1, and on the element substrate 1. The liquid flow path 10 is arranged corresponding to the heating element 2. The liquid flow path 10 is in communication with the discharge port 18 and also with the common liquid chamber 13 for supplying liquid to the plurality of liquid flow paths 10, and has an amount commensurate with the liquid discharged from the discharge port 18. The liquid is received from this common liquid chamber 13. Reference symbol M represents a meniscus formed by the discharge liquid,
The meniscus M is balanced in the vicinity of the discharge port 18 with respect to the internal pressure of the common liquid chamber 13, which is usually a negative pressure due to the capillary force generated by the discharge port 18 and the inner wall of the liquid flow path 10 communicating with the discharge port 18.

The liquid flow path 10 is constructed by joining the element substrate 1 provided with the heating element 2 and the top plate 50, and heat is generated in the area in the vicinity of the surface where the heating element 2 contacts the discharge liquid. There is a bubble generation region 11 in which the body 2 is rapidly heated to cause foaming in the discharged liquid. In the liquid flow path 10 having the bubble generation region 11, the movable member 31 is at least partially formed in the heating element 2.
It is arranged so as to face. The movable member 31 has a free end 32 on the downstream side toward the discharge port 18, and
It has a cantilever shape with one end supported by a support member 34 arranged on the upstream side of the liquid flow path 10. In particular, in the present embodiment, the free end 3 is suppressed in order to suppress the growth of the upstream half of the bubbles, which affects the back wave to the upstream side and the inertial force of the liquid.
2 is arranged near the center of the bubble generation region 11. The movable member 31 can be displaced with respect to the support member 34 as the bubbles generated in the bubble generation region 11 grow. The fulcrum 33 at the time of this displacement serves as a support portion of the movable member 31 in the support member 34.

A stopper (regulating portion) 64 is located above the center of the bubble generating region 11 and regulates the displacement of the movable member 31 within a certain range in order to suppress the growth of the upstream half of the bubble. In the flow from the common liquid chamber 13 to the discharge port 18, a low flow path resistance region 65 having a flow path resistance relatively lower than that of the liquid flow path 10 is provided on the upstream side of the stopper 64 as a boundary. The flow channel structure in this region 65 has no upper wall or has a large flow channel cross-sectional area, so that the resistance received from the flow channel with respect to the movement of the liquid is reduced.

With the above structure, the displaced movable member 31
It proposes a unique head structure in which the liquid flow path 10 having the bubble generation region 11 becomes a substantially closed space except for the discharge port 18 by the contact between the stopper 64 and the stopper 64.

Next, the ejection operation of the liquid ejection head of this embodiment will be described in detail. Note that FIG. 1 shows the first liquid discharge, and FIG. 2 shows the second liquid discharge that is subsequently performed. FIG. 3 is a graph showing the volume of bubbles and the displacement of the movable member during driving.

FIG. 1 (a) shows a state before energy such as electric energy is applied to the heating element 2 and shows a state before the heating element generates heat. What is important here is that the movable member 31 is provided at a position (initial state) facing the upstream half of the bubble generated by the heat generated by the heating element 2, and That is, the stopper 64 that restricts the displacement is provided above the center of the bubble generation region 11. That is, depending on the liquid flow path structure and the arrangement position of the movable member, the upstream half of the bubble is pressed into the movable member 31. When an electric pulse is applied to the heating element at time T = 0 shown in FIG. 3, a part of the liquid filling the bubble generation region 11 is heated by the heating element 2, bubbles are generated due to film boiling, and the bubbles are generated with time. It grows and becomes large in volume. At this time, due to the repulsive force of the movable member, the displacement of the movable member starts later than the change in the volume of the bubble (time A in FIG. 3).

As the bubbles grow as shown in FIG.
The movement of the liquid toward the upstream side, that is, toward the common liquid chamber 13 becomes a large flow due to the low flow path resistance region 65, but when the movable member 31 is displaced until it approaches or contacts the stopper 64, further displacement is restricted. (Time B shown in FIG. 3). Therefore, the movement of the liquid in the upstream direction is also greatly restricted there. That is, in the displaced state of the movable member 31, the upstream side of the liquid flow path 10 (at least the upstream side of the center of the bubble generation region 11) is substantially closed, and the liquid flow path 10 and the common liquid located upstream thereof. The flow of liquid and air bubbles with the chamber 13 is substantially blocked. As a result, the growth of the bubbles 40 on the upstream side is also limited by the movable member 31.
However, since the moving force of the liquid in the upstream direction is large, the movable member 31 is largely bent by the stress pulled in the upstream direction and is held in a bent state, and the bubbles grow to the maximum volume as described above (Fig. (Point C of 3). Figure 1 (b)
Indicates a state in which the bubbles in the bubble generation region 11 have grown to the maximum. At this time, the liquid in the liquid flow path 10 moves to the downstream side and the upstream side due to the pressure based on the generation of the bubbles 40, the movable member 31 is displaced by the growth of the bubbles 40 on the upstream side, and the discharge port on the downstream side. The ejected droplet 66 is about to be ejected from 18.

In the present invention, as shown in FIG. 4, a "linear communication state" is maintained between the discharge port side portion of the bubble 40 and the discharge port, maintaining a straight flow path structure for the liquid flow. ing. More preferably, this is because the propagating direction of the pressure wave generated when the bubbles are generated and the liquid flowing direction and the ejecting direction corresponding to the propagating direction are linearly aligned with each other, so that the ejecting state of the ejected droplet 66, the ejecting speed, and the like. It is desirable to create the ideal state of stabilizing V at a very high level.
In the present invention, as one definition for achieving or approximating this ideal state, the discharge port 18 and the heating element 2, particularly the discharge port side (downstream side) of the heating element having influence on the discharge port side of bubbles.
It suffices that the and are directly connected by a straight line. This means that when there is no fluid in the flow path, the heating element, especially the downstream side of the heating element, can be observed when viewed from the outside of the discharge port. It is in a state.

Thereafter, as shown in FIG. 1C, after the above-mentioned film boiling, the negative pressure inside the bubble overcomes the movement of the liquid to the downstream side in the liquid flow path, and the contraction of the bubble 40 is started. It At this point, since a large force of the liquid in the upstream direction due to bubble growth remains, the movable member 31 is still in contact with the stopper 64 for a certain period after the start of contraction of the bubble 40, and most of the contraction of the bubble 40 occurs. Causes the liquid to move from the discharge port 18 in the upstream direction. That is, immediately after the stage shown in FIG. 1B, the upstream side of the liquid flow path 10 is closed by the contact between the displaced movable member 31 and the stopper 64, and the liquid flow path 10 having the bubble generation region 11 is discharged. Except for exit 18.
Since the space is substantially closed, the contraction energy of the bubble 40 acts as a force for moving the liquid near the ejection port 18 in the upstream direction. Therefore, the meniscus M is largely drawn into the liquid flow path 10 from the discharge port 18 at this point,
The liquid column connected to the ejected droplet 66 is quickly separated with a strong force. As a result, as shown in FIG. 1D, the number of droplets, that is, satellites (sub droplets) 67 left outside the ejection port 18 decreases.

FIG. 1 (d) shows a state in which the discharging droplet 66 and the meniscus M are separated after the defoaming process is completed. First,
In the low flow path resistance region 65, the repulsive force of the movable member 31 exceeds the moving force of the liquid in the upstream direction, and the downward displacement of the movable member 31 (return from the displaced state to the initial state) and the low flow path resistance region 65 associated therewith. And the flow in the downstream direction is started (at the point D in FIG. 3). At the same time, the flow in the downstream direction in the low flow resistance region 65 has a small flow resistance, so that it rapidly becomes a large flow and flows into the liquid flow path 10 via the stopper 64 portion. As a result, the flow that rapidly draws the meniscus M into the liquid flow path 10 suddenly decreases, so that the meniscus M draws the liquid column portion remaining outside from the discharge port 18 to a position before foaming at a relatively low speed. Start returning. Therefore,
Vibration of the meniscus can be converged at high speed.

On the other hand, the ejected droplet 66 and the satellite 67 existing immediately thereafter are very close to each other due to the rapid meniscus drawing in FIG. 1C, and the ejected droplet 66 is formed into a ejected droplet by the vortex of air generated behind the flight of the ejected droplet 66. A phenomenon called a slipstream phenomenon occurs, which receives a force attracted.

This phenomenon will be described in detail. In the conventional liquid ejection head, the droplet does not form a sphere at the moment when the liquid is ejected from the ejection port, and is ejected in a state close to a liquid column having a spherical portion at the tip. It is known that when the trailing portion is pulled by both the main droplet and the meniscus and separated from the meniscus, satellite dots are formed from the trailing portion and fly to the recording medium together with the main droplet. . Since the satellite dots fly after the main droplet, the ejection speed is low because the satellite dot is pulled by the meniscus, and the landing position of the satellite dot deviates from the main droplet, deteriorating the print quality. In the liquid ejection head according to the present invention,
As described above, since the force for retracting the meniscus is larger than that of the conventional liquid ejection head, the force for pulling the tailing portion after the main droplet is ejected is strong, and the force for separating the tailing portion and the meniscus becomes strong, and this separation is performed. The timing will be earlier. The strong retreat force of the meniscus and the high speed means that the trailing portion between the main droplet and the meniscus is pulled fast as shown in FIG. Will be more slender than. The liquid column is easily separated at this elongated portion, and as a result, the satellite dots formed from the trailing portion become smaller and the distance between the main droplet and the satellite dot becomes shorter. In addition, the tail part does not continue to be pulled by the meniscus forever,
The discharge speed does not decrease, and the satellite 67 is attracted behind the discharge droplet 66 by a so-called slipstream phenomenon.

As described above, the retreat of the meniscus is fast and the tailing portion becomes thin because the bubble 40 is contracted, but the upstream side of the liquid flow path 10 is closed and the liquid is drawn from the upstream side. This is because the liquid cannot be obtained and the liquid is drawn only from the downstream side (near the ejection port). This state occurs from the time point C in FIG. 3 (when the bubble 40 is at the maximum volume, that is, when defoaming starts) to the time point D (when the movable member 31 starts returning).

FIG. 1E shows a further advanced state of FIG. 1D. The satellite 67 has a further drop 66.
And are attracted at the same time, and the pulling force due to the slipstream phenomenon also increases. On the other hand, from the upstream side, the discharge port 18
In the movement of the liquid in the direction, the displacement overshoot of the movable member 31 causes the liquid to be displaced downward from the initial position (at the point E in FIG. 3) so that the liquid is drawn in from the upstream side and the liquid is pushed out toward the ejection port 18. Give rise to. Moreover, the stopper 6
The cross-sectional area of the liquid flow path where 4 exists increases the liquid flow in the direction of the discharge port 18, and the return of the meniscus M to the discharge port 18 is accelerated. As a result, the refill characteristics in this embodiment are dramatically improved.

FIG. 1F shows a state where the state of FIG. 1E has further advanced and the satellite 67 has been taken into the ejected droplet 66. The combination of the discharge droplet 66 and the satellite 67 does not always occur in each discharge even in the other embodiments.
It may or may not occur depending on the conditions. However, by at least reducing or eliminating the amount of satellites, the landing positions of the main droplets and satellite dots hardly shift on the recording medium, and the influence on print quality becomes extremely small. That is, the sharpness of the image can be enhanced to improve the printing quality, and the harmful effects such as becoming a mist and contaminating the inside of the printing medium or the recording apparatus can be reduced.

On the other hand, the movable member 31 is displaced in the direction of the stopper 64 again due to the reaction of the overshoot.
This causes damping vibration determined by the shape and Young's modulus of the movable member 31, the viscosity of the liquid in the liquid flow path, and the specific gravity. The second liquid ejection operation is performed before the damping vibration is converged. That is, in the present embodiment, when liquid is continuously discharged from the same discharge port 18, before the vibration of the movable member 31 after the previous liquid discharge is completed converges to the state shown in FIG.
When the movable member 31 is being displaced upward (to the side of the stopper 64) as shown in, the next drive pulse is supplied to the heating element 2 (time F in FIG. 3). Then, the movable member 31
While displacing upward, bubbles 40
Occurs and grows. Since the movable member 31 has an upward acceleration in advance, the displacement of the bubble 40 is displaced almost at the same time as the volume change of the bubble 40 without delaying the start of displacement with respect to the growth of the bubble 40 due to the rigidity of the movable member. At time G in FIG. 3, the movable member 31 comes into contact with the stopper 64 to close the upstream side of the liquid flow path 10, and the bubble generation region 11 is substantially closed except for the discharge port 18, and at time H in FIG. As shown in FIG. 2B, the bubbles have the maximum volume. At this time, the discharge droplet 66 is being discharged from the discharge port 18.

Next, the defoaming process starts. The contraction of the bubbles 40 in the initial stage of defoaming causes the movement of the liquid from the discharge port to largely draw the meniscus and separate the liquid column connected to the discharged liquid droplet. Figure 1 for a while after time H
Similar to (c), the movable member 31 is in a displaced state in contact with the stopper, the upstream side of the liquid flow path 10 is substantially closed, and the suction force due to the contraction of the bubbles 40 mainly draws in the liquid from the meniscus. As described above, the repulsive force of the meniscus is strong and the speed is high. Therefore, as mentioned above,
The liquid column becomes extremely thin in the trailing portion between the main droplet and the meniscus. However, the movable member 31 starts downward displacement at time J in FIG. 3, and the flow from the low flow path resistance region 65 to the downstream direction (direction of the discharge port) is started. At this time,
As shown in (c), as the regulation by the movable member 31 is released, the liquid in the low flow path resistance region 65 flows into the vicinity of the bubble generation region all at once, and the liquid flow path 10 moves from the upstream side to the downstream side. A strong liquid flow occurs. This liquid flow acts on the flow that has rapidly drawn in the meniscus, whereby the retreating speed of the meniscus rapidly decreases, and the liquid column in the tailing portion becomes thick.

As described above, the tailing portion becomes thin during the maximum volume of the bubble 40, that is, from the start of defoaming to the start of restoration of the movable member 31, and here, at time H in FIG. To the time point J. Further, in the present embodiment, since the heating element 2 is driven during the upward displacement of the movable member 31, after the time point F, the displacement of the volume change timing between the movable member and the bubble 40 is small, and the volume contraction of the bubble 40 occurs. The movable member is displaced downward substantially following the. Therefore, FIG.
The time lag from time H to time J is small. As a result, as shown in FIG. 2C, a thin portion 68 of the liquid column that is connected to the main droplet exists for a very short length, and subsequently, a thick portion of the liquid column extends to the meniscus.

Then, as shown in FIG. 2D, the discharged droplets discharged to the outside and the meniscus drawn into the liquid flow path 10 are separated. As described above, since the thin portion 68 exists in the trailing portion between the ejected droplet and the meniscus, the thin portion 68 is cut and the two are separated. Moreover, since the thin portion 68 has an extremely short length, it is easy to surely cut at one place. On the other hand, the portion other than the thin portion 68 has a thick liquid column, so that there is almost no separation outside the discharge port. Be drawn into the exit. Therefore, the number of droplets, that is, satellites, left behind on the outside of the ejection port is reduced.

FIG. 2 (e) shows a state in which the movable member is overshooting toward the heating element from the position in the initial state. The movement of the liquid from the upstream direction toward the discharge port changes below the initial position of the movable member, causing the liquid to be drawn from the upstream side and the liquid to be pushed out toward the discharge port, and the liquid flow in the stopper area. The expansion of the cross-sectional area of the road increases the amount of liquid in the direction of the ejection port, and accelerates the return of the meniscus to the ejection port. As a result, the refill characteristics in this embodiment are dramatically improved.

As described above, by applying the drive pulse to the heating element while the movable member is being displaced upward (to the stopper side), the displacement of the bubble 40 and the displacement of the movable member are small. The downward displacement of the movable member is completed in a short time, and the number of satellites can be reduced. In addition, the satellite speed becomes faster, and it is easy to contact and integrate with the main droplet during flight.

Next, further characteristic effects of this embodiment will be described.

FIG. 5 is a see-through perspective view of a part of the head shown in FIG. 1 (b), which basically shows the same state as that shown in FIG. 1 (b) except that the nozzle is seen through and shown by a broken line. is there. In this embodiment, there is a slight clearance between both side wall surfaces of the wall forming the liquid flow path 10 and both side portions of the movable member 31 to allow the movable member 31 to be smoothly displaced.
Further, in the step of growing foam by the heating element 2, the bubble 40 displaces the movable member 31 and bulges toward the upper surface side of the movable member 31 through the clearance and slightly enters the low flow path resistance region 65. This rising bubble 41
Wraps around the back surface of the movable member 31 (the surface opposite to the bubble generation region 11) to suppress the blurring of the movable member 31 and stabilize the ejection characteristics.

Further, in the defoaming process of the bubble 40, the raised bubble 41 is moved from the low flow path resistance region 65 to the bubble generation region 11
The liquid flow to the nozzle is accelerated, and the defoaming is promptly completed in combination with the above-described high-speed drawing of the meniscus from the discharge port 18 side. In particular, the liquid flow caused by the raised bubbles 41 hardly accumulates the bubbles in the movable member 31 or the corners of the liquid flow path 10.

(Other Embodiments) Various embodiments applicable to the head using the above-described liquid ejecting method will be described below.

<Movable Member> FIG. 6 shows another shape of the movable member 31. The figure (a) is a rectangular shape, the figure (b) is a shape in which the fulcrum side is narrow and the shape of the movable member is easy to operate, and the figure (c) is wide in the fulcrum side and the movable member is The shape improves the rigidity of the.

In the previous embodiment, the movable member 31 was made of nickel having a thickness of 5 μm. However, the material of which the movable member 31 is made is not limited to this. Any member may be used as long as it has elasticity so that it can operate well as a member.

As the material of the movable member 31, silver, nickel, gold, iron, titanium, aluminum, which has high durability,
Metals such as platinum, tantalum, stainless steel, phosphor bronze, and their alloys, or acrylonitrile, butadiene,
Resins having nitrile groups such as styrene, resins having amide groups such as polyamide, resins having carboxyl groups such as polycarbonate, resins having aldehyde groups such as polyacetal, resins having sulfone groups such as polysulfone, and other liquid crystal polymers, etc. Resin and its compounds,
Metals with high ink resistance such as gold, tungsten, tantalum, nickel, stainless steel, and titanium, alloys of these, and those having ink resistance coated on the surface, resins having amide groups such as polyamide, polyacetal, etc. Resin having aldehyde group, resin having ketone group such as polyetheretherketone, resin having imide group such as polyimide, resin having hydroxyl group such as phenol resin, resin having ethyl group such as polyethylene, alkyl such as polypropylene Resin with a base,
A resin having an epoxy group such as an epoxy resin, a resin having an amino group such as a melamine resin, a resin having a methylol group such as a xylene resin and a compound thereof, and a ceramic such as silicon dioxide and silicon nitride and a compound thereof are preferable.
The thickness of the μm order is targeted as the movable member 31 in the present invention.

Next, the positional relationship between the heating element and the movable member will be described. By the optimal arrangement of the heating element and the movable member,
The flow of the liquid at the time of foaming by the heating element can be properly controlled and effectively used.

By applying energy such as heat to the ink, a state change accompanied by a sharp volume change (generation of bubbles 40) is generated in the ink, and the ink is ejected from the ejection port by an action force based on this state change. In the prior art of an ink jet recording method for forming an image by attaching this onto a recording medium, a so-called bubble jet recording method,
As shown in FIG. 7, the area of the heating element and the ink ejection amount are in a proportional relationship, but the non-foaming effective area S that does not contribute to the ink ejection.
It turns out that exists. Further, from the state of kogation on the heating element, it can be seen that the non-foaming effective area S exists around the heating element. From these results, it is considered that the width of about 4 μm around the heating element is not involved in foaming.

Therefore, in order to effectively utilize the foaming pressure, the region directly above the foaming effective region of about 4 μm or more from the periphery of the heating element is the region where the movable member effectively acts,
In the case of the present invention, the action of the bubbles on the upstream side and the downstream side of the substantially central region of the bubble generation region (actually within a range of ± about 10 μm in the liquid flow direction from the center) on the liquid flow in the liquid passage is independently performed. Focusing on the distinction between the actuating stage and the synthetic actuating stage, it is extremely important to dispose the movable member such that only the upstream side portion of the central region faces the movable region of the movable member. I can say. In the present embodiment, the effective foaming area is set to be approximately 4 μm or more inside from the periphery of the heating element, but it is not limited to this depending on the kind of the heating element and the forming method.

<Element Substrate> Next, the structure of the element substrate will be described.

8A and 8B are vertical sectional views of the liquid discharge head of the present invention. FIG. 8A shows a head having a protective film described later, and FIG. 8B shows it without a protective film.

The liquid flow path 10, the discharge port 18 communicating with the liquid flow path 10, the low flow path resistance region 65, and the top plate 50 provided with the groove forming the common liquid chamber 13 are arranged on the element substrate 1. .

The element substrate 1 is provided with a substrate 107 such as silicon.
A silicon oxide film or a silicon nitride film 106 for the purpose of insulation and heat storage is formed on the film, and hafnium boride (HfB2), tantalum nitride (TaN), and tantalum aluminum (TaAl) that constitute the heating element 2 are formed thereon. 8) and the electric resistance layer 105 (0.01 to 0.2 μm thick) and the wiring electrode 104 such as aluminum (0.2 to 1.0 μm thick) are patterned as shown in FIG. A voltage is applied from the wiring electrode 104 to the resistance layer 105, and a current is passed through the resistance layer to generate heat. A protective layer 103 made of silicon oxide, silicon nitride, or the like is formed on the resistance layer between the wiring electrodes by 0.1 to 0.1%.
It is formed to a thickness of 2.0 μm, and a cavitation resistant layer 102 (0.1 to 0.6 μm thick) such as tantalum is further formed thereon.
The resistance layer 1 is formed from various liquids such as ink.
05 is protected.

In particular, the pressure and shock waves generated during bubble generation and defoaming are extremely strong, and the durability of a hard and brittle oxide film is significantly reduced. Therefore, tantalum (Ta), which is a metal material, is used.
Etc. are used as the anti-cavitation layer 102.

Further, depending on the combination of the liquid, the liquid flow path structure, and the resistance material, the above-mentioned resistance layer 105 may not have the protective layer 103, and an example thereof is shown in FIG. 8B. Examples of the material of the resistance layer 105 that does not require the protective layer 103 include iridium-tantalum-aluminum alloy.

As described above, as the constitution of the above-mentioned heating element, only the resistance layer (heating portion) between the above-mentioned electrodes may be used,
It may also include a protective layer for protecting the resistance layer.

Although a heating element having a heating portion composed of a resistance layer that generates heat in response to an electric signal is used here, the heating element is not limited to this, and bubbles sufficient for ejecting the ejection liquid are formed. Any material can be used as long as it can be generated in the foaming liquid.
For example, the heat generating portion may be a photothermal converter that generates heat when receiving light from a laser or the like, or a heat generating body that has a heat generating portion that generates heat when receiving high frequency.

On the element substrate 1 described above, in addition to the electrothermal converter constituted by the resistance layer 105 forming the heat generating section and the wiring electrode 104 for supplying an electric signal to the resistance layer, Functional elements such as a transistor, a diode, a latch, and a shift register for selectively driving the electrothermal conversion element may be integrally formed in the semiconductor manufacturing process.

Further, in order to drive the heat generating portion of the electrothermal converter provided on the element substrate 1 as described above and eject the liquid, the resistance layer 105 is connected to the resistance layer 105 via the wiring electrode 104 as shown in FIG. A rectangular pulse as shown by is applied to rapidly generate heat in the resistance layer 105 between the wiring electrodes. In the head of each of the above-described embodiments, the voltage is 24 V, the pulse width is about 4 μsec, the current is about 100 mA, and the electric signal is 6 kHz.
By adding the above, the heating element was driven, and the liquid ink was ejected from the ejection port by the above-described operation. However, the condition of the drive signal is not limited to this, and any drive signal capable of appropriately foaming the foaming liquid may be used.

<Discharge Liquid> Among such liquids, as the liquid used for recording (recording liquid), the ink having the composition used in the conventional bubble jet device can be used.

Further, it is possible to use even a liquid having a low foaming property which has been difficult to be ejected conventionally, a liquid which is easily deteriorated or deteriorated by heat, a high viscosity liquid and the like.

However, as the properties of the discharge liquid, the discharge liquid itself is
It is desired that the liquid is not a liquid that hinders ejection, foaming, movement of the movable member, or the like.

High-viscosity ink or the like can also be used as the ejection liquid for recording.

In the present invention, recording was performed using an ink having the following composition as a recording liquid that can be used as the discharge liquid. However, since the discharge speed of the ink increased due to the improvement of the discharge force, the liquid The landing accuracy of the drops is improved, and a very good recorded image can be obtained.

Composition of dye ink (viscosity 2 cP) (C-1. Food Black 2) Dye 3% by weight Diethylene glycol 10% by weight Thiodiglycol 5% by weight Ethanol 5% by weight 77% by weight of water

<Structure of Liquid Discharging Head> FIG. 10 is an exploded perspective view showing the overall structure of the liquid discharging head of the present invention.

An element substrate 1 having a plurality of heating elements 2 is provided on a support 70 made of aluminum or the like. A support member 34 that supports the movable member 31 is provided thereon so as to face the half of each heating element 2 on the common liquid chamber 13 side. Further, a top plate 50 provided with a plurality of grooves forming the liquid flow path 10 and concave grooves of the common liquid chamber 13 is provided thereon.

<Side Shooter Type> Here, FIG.
Also, the liquid ejection principle described with reference to FIG. 2 is applied to a side shooter type head in which a heating element and an ejection port face each other on a parallel plane. FIG. 11 is a diagram for explaining this side shooter type head.

In FIG. 11, the heating element 2 on the element substrate 1
And the discharge port 18 formed in the top plate 50 are arranged so as to face each other. The discharge port 18 communicates with the liquid flow path 10 that passes over the heating element 2. A bubble generation region exists in a region near the surface where the heating element 2 contacts the liquid. And the element substrate 1
Two movable members 31 are supported above, and each movable member is formed so as to be plane-symmetric with respect to a plane passing through the center of the heating element, and the free end of each movable member 31 is on the heating element 2. It is located to face each other. The movable members 31 have the same projected area on the heating element 2, and the free ends of the movable members 31 are separated by a desired size. Here, assuming that each movable member is divided by the dividing wall of the surface passing through the center of the heating element, the free end of the movable member is provided near the center of each divided heating element. .

The top plate 50 is provided with a stopper 64 for restricting the displacement of each movable member 31 within a certain range. In the flow from the common liquid chamber 13 to the discharge port 18, the stopper 64
A low flow path resistance region 65 having a flow path resistance relatively lower than that of the liquid flow path 10 is provided on the upstream side of the boundary. The flow channel structure in this region 65 has a flow channel cross-sectional area larger than that of the liquid flow channel 10, and thus reduces the resistance received from the flow channel with respect to the movement of the liquid.

Next, the characteristic action of the structure of this embodiment
Explain the effect.

FIG. 11A shows a state in which a part of the liquid filling the bubble generation region 11 is heated by the heating element 2 and the bubbles 40 accompanying the film boiling have grown to the maximum. At this time, the liquid in the liquid flow path 10 moves toward the ejection port 18 due to the pressure generated by the generation of the bubble 40, each movable member 31 is displaced by the growth of the bubble 40, and the ejection droplet 66 is likely to fly out from the ejection port 18. I am trying. Here, the movement of the liquid in the direction of the common liquid chamber 13 becomes a large flow due to the respective low flow path resistance regions 65, but when the two movable members 31 are displaced until they come close to or come into contact with the respective stoppers 64, further movement will occur. Since the displacement is regulated, the movement of the liquid in the common liquid chamber 13 direction is also greatly restricted there. At the same time, the growth of the bubbles 40 on the upstream side is also limited by the movable member 31. However, since the moving force of the liquid in the upstream direction is large, a part of the bubbles 40, the growth of which is restricted by each movable member 31, may be generated in the gap between the side wall forming the liquid flow path 10 and the side portion of the movable member 31. As described above, the upper surface of the movable member 31 is raised. That is, the raised bubble 41
Is formed.

When the contraction of the bubble 40 is started after the film boiling, the movable member 31 is still in contact with the stopper 64 because the force of the liquid in the upstream direction remains large at this point. Most of the contraction of 40 is the discharge port 18
Liquid is caused to flow in the upstream direction. Therefore, the meniscus is largely drawn from the ejection port 18 into the liquid flow path 10 at this point, and the liquid column connected to the ejection droplet 66 is quickly separated with a strong force. As a result, the amount of droplets, that is, satellites, left behind on the outside of the ejection port 18 is reduced.

When the defoaming process is almost completed, the movable member 3 is moved by the moving force of the liquid in the upstream direction in each low flow path resistance region 65.
The repulsive force (restoring force) of 1 prevails, and the downward displacement of the movable member 31 and the subsequent flow in the low flow path resistance region 65 in the downstream direction are started. At the same time, the flow in the downstream direction in the low flow resistance region 65 has a small flow resistance, so that it rapidly becomes a large flow and flows into the liquid flow path 10 via the stopper 64 portion. FIG. 11B shows AB the liquid flow in the defoaming process of the bubbles 40. Liquid flow A is common liquid chamber 1
The liquid from 3 is the upper surface of the movable member 31 (the surface opposite to the heating element)
The component flowing toward the discharge port 18 through the side
Indicates a component flowing on both sides of the movable member 31 and on the heating element 2.

As described above, in this embodiment, the refill property is enhanced at a higher speed by supplying the ejection liquid from the low flow path resistance region 65. Further, since the common liquid chamber 13 adjacent to the low flow path resistance region 65 has the flow path resistance further reduced, high speed refilling is possible.

Further, in the defoaming process of the bubbles 40, the raised bubbles 41 are moved from the low flow path resistance regions 65 to the bubble generation regions 1
The liquid flow to No. 1 is promoted, and the defoaming is promptly completed in combination with the above-described high-speed drawing of the meniscus from the discharge port 18 side. In particular, the liquid flow caused by the raised bubbles 41 hardly accumulates the bubbles in the movable member 31 or the corners of the liquid flow path 10.

Further, also in the liquid discharge head shown in FIG. 11, when liquid is continuously discharged from the same discharge port 18 as in the embodiment shown in FIGS. Member 31 that returns to the initial state from
If the driving pulse is supplied to the heating element 2 to start the generation of bubbles during the displacement of the movable member toward the displacement state (to the stopper 64 side) before the vibration of the Can be reduced.

<Liquid Ejecting Device> FIG. 12 is shown in FIGS.
2 shows a schematic configuration of a liquid ejection device equipped with the liquid ejection head having the structure described in FIG. In this embodiment, an ink discharge recording apparatus using ink as a discharge liquid will be described in particular. The carriage HC of the liquid ejecting apparatus includes a liquid tank portion 90 for containing ink and a liquid ejecting head portion 200.
A recording medium 1 such as recording paper, which is mounted with a detachable head cartridge and is conveyed by a recording medium conveying means.
It reciprocates in the width direction of 50.

When a drive signal is supplied from the drive signal supply means (not shown) to the liquid ejection means on the carriage, the recording liquid is ejected from the liquid ejection head onto the recording medium in response to this signal.

Further, in the liquid ejecting apparatus of this embodiment, the motor 111 as a drive source for driving the recording medium conveying means and the carriage, the gears 112, 113 for transmitting the power from the drive source to the carriage, It has a carriage shaft 115 and the like. With this recording apparatus and the liquid ejecting method performed by this recording apparatus, it is possible to obtain a recorded image with a good image by ejecting liquid onto various recording media.

FIG. 13 is a block diagram of the entire apparatus for operating ink discharge recording in the liquid discharge method and liquid discharge head of the present invention.

The recording apparatus receives print information as a control signal from the host computer 300. The print information is temporarily stored in the input interface 301 inside the printer, and at the same time, converted into data that can be processed within the recorder, and the CPU (control means) 30 that also serves as a head drive signal supply means.
Entered in 2. Based on the control program stored in the ROM 303, the CPU 302 processes the data input to the CPU 302 by using a peripheral unit such as the RAM 304 and converts the data into print data (image data).

Further, the CPU 302 produces drive data for driving a drive motor that moves the recording sheet and the recording head in synchronization with the image data in order to record the image data at an appropriate position on the recording sheet. . The image data and the motor drive data are respectively sent to the head driver 307.
Is transmitted to the head 200 and the drive motor 306 via the motor driver 305, and driven at each controlled timing to form an image.

The recording medium which can be applied to the recording apparatus as described above and to which a liquid such as ink is applied is various kinds of papers, OHP sheets, plastic materials, cloths, aluminum used for compact discs, decorative plates and the like. Metal materials such as copper and copper, leather materials such as cowhide, pigskin and artificial leather, wood materials such as wood and plywood, bamboo materials, ceramic materials such as tiles, and three-dimensional structures such as sponges can be targeted.

Further, as the above-mentioned recording device, a printer device for recording on various kinds of paper or OHP sheets, a recording device for plastics for recording on a plastic material such as a compact disc, a metal for recording on a metal plate. Recording device, recording device for leather for recording on leather, recording device for wood for recording on wood, recording device for ceramics for recording on ceramic material, recording device for recording on three-dimensional mesh structure such as sponge It also includes a printing device for recording on the cloth.

As the ejection liquid used in these liquid ejection devices, liquids suitable for each recording medium and recording conditions may be used.

[0096]

According to the valve mechanism of the movable member of the liquid discharge head according to the present invention, the movement of the liquid in the upstream direction due to the back wave, that is, the pressure wave in the upstream direction is suppressed, and at the same time, the meniscus is rapidly introduced into the discharge port. By pulling in, it is possible to prevent satellite dots, stabilize the ejection amount, and improve the printing quality.

In particular, according to the present invention, when liquid is continuously discharged from the same discharge port, it is possible to move before the vibration of the movable member returning from the displacement state to the initial state after the liquid discharge is completed and before it is moved. If the generation of bubbles for the next liquid ejection is started while the member is displaced toward the displaced state, the number of satellites can be further reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of one embodiment of a liquid ejection head of the present invention taken along the liquid flow path direction, showing the first liquid ejection operation divided into steps (a) to (f). It is a thing.

2A to 2C show a second liquid ejection operation subsequent to FIG.
It is shown separately for the step (e).

FIG. 3 is a graph showing a relationship between bubble growth and displacement of a movable member.

FIG. 4 is a “linear communication state” of the liquid ejection head of the present invention.
FIG. 3 is a cross-sectional view of a flow path illustrating FIG.

5 is a perspective view of a part of the head shown in FIG. 1 (b).

6 shows an example of the shape of the movable member shown in FIG.

FIG. 7 is a graph showing a relative relationship between a heating element area and an ink ejection amount.

8A and 8B are vertical cross-sectional views of a liquid discharge head of the present invention, in which FIG. 8A shows a protective film and FIG. 8B does not have a protective film.

FIG. 9 is a waveform diagram for driving a heating element used in the present invention.

FIG. 10 is an exploded perspective view showing the overall configuration of the liquid ejection head of the present invention.

FIG. 11 is a diagram for explaining a side shooter type head to which the liquid ejection method of the present invention is applied.

FIG. 12 is a diagram showing a schematic configuration of a liquid ejection apparatus equipped with the liquid ejection head having the structure described in FIGS. 1 and 11.

FIG. 13 is a block diagram of an entire apparatus for operating ink ejection recording in the liquid ejection method and liquid ejection head of the present invention.

[Explanation of symbols]

1 element substrate 2 heating element 10 liquid flow paths 11 Bubble generation area 13 Common liquid chamber 18 outlets 31 Movable member 32 Free end 33 fulcrum 34 Support member 40 bubbles 50 Top plate 64 Stopper 65 Low flow resistance area 66 ejected drops 67 satellites 68 Thin part 70 Support 90 ink tank 102 Anti-cavitation layer 103 protective layer 104 wiring electrode 105 Resistance layer 106 silicon nitride film 107 base 111 motor 112, 113 gears 115 Carriage axis 150 recording media 200 heads 300 host computer 301 Input / output interface 302 CPU 303 ROM 304 RAM 305 motor driver 306 Drive motor 307 head driver

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Shimazu 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Sadayuki Sugama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. Within the corporation (56) Reference JP-A-9-226125 (JP, A) JP-A-10-76657 (JP, A) JP-A-9-123453 (JP, A) JP-A-9-193377 (JP, A) JP-A-10-76655 (JP, A) JP-A-4-173338 (JP, A) JP-A-9-327933 (JP, A) JP-A-10-24610 (JP, A) JP-A-8 -118638 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B41J 2/05 B41J 2/175

Claims (12)

(57) [Claims] 1. A liquid in a liquid flow path is heated to generate bubbles in the liquid to grow, and a cantilever-shaped movable member supported in one end provided in the liquid flow path is used as the bubbles. Is displaced from the initial state as the bubble grows, and when the bubble reaches the maximum volume, the upstream side of the liquid flow path is substantially closed by the movable member and the pressure from the discharge port causes the bubble to grow from the outlet. A method for ejecting the liquid, wherein the movable member returns from the displaced state to the initial state with the disappearance of the bubbles after the liquid is ejected. When performing liquid ejection, before the vibration of the movable member returning from the displaced state after the previous liquid ejection is completely converged, the movable member is displaced in the direction toward the displaced state. For the next liquid discharge while Liquid discharging method characterized by starting heating of serial liquid. 2. The liquid discharge method according to claim 1, wherein movement of the liquid in the upstream direction and growth of the bubbles are regulated by substantially closing the upstream side of the liquid flow path by the movable member. . 3. The free end of the movable member is located substantially in the center of the bubble generation region in the liquid flow path, and the displacement member is provided in the liquid flow path when the movable member is displaced. The liquid discharging method according to claim 1, wherein the upstream side of the liquid flow path is substantially closed by substantially contacting the free end with. 4. The liquid ejecting method according to claim 1, wherein a heating element is provided in the liquid flow path, and the liquid is heated by driving the heating element. 5. The liquid ejection method according to claim 4, wherein the heating element is an electrothermal converter, and the liquid is heated by supplying a drive pulse to the electrothermal converter. 6. The liquid ejection method according to claim 1, wherein the contact between the movable member and the restriction portion is maintained for a certain period of time after the start of defoaming of the bubbles. 7. A heating element that heats the liquid in the liquid flow path to generate bubbles in the liquid, and the liquid is discharged by a pressure that is connected to the downstream side of the liquid flow path and that accompanies the growth of the bubbles. A discharge port, a movable member provided in a cantilever shape with one end supported in the liquid flow path, and a free end positioned on the discharge port side, and the movable member when the movable member is displaced due to growth of the bubbles. And a control unit for substantially closing the upstream side of the liquid flow path and a control unit for controlling the drive of the heating element, wherein the control unit has the same liquid flow. When the liquid is continuously discharged from the passage, the movable member moves to the displaced state before the vibration of the movable member returning from the displaced state after the previous liquid discharge is completely converged. Driving the heating element for the next liquid discharge while it is being displaced in the direction A liquid discharge head to perform. 8. The movement of the liquid in the upstream direction and the growth of the bubbles are achieved by substantially contacting the movable member and the restriction portion with each other to substantially close the upstream side of the liquid flow path. The liquid ejection head according to claim 7, which is regulated. 9. The liquid ejection head according to claim 7, wherein the flow resistance of the liquid flow path on the side opposite to the ejection port is low with the restriction portion as a boundary when the movable member is on standby. 10. The liquid ejection head according to claim 7, wherein the heating element is an electrothermal converter, and a drive pulse is supplied from the control means. 11. A liquid, comprising: the liquid ejection head according to claim 1; and a recording medium conveyance unit that conveys a recording medium that receives the liquid ejected from the liquid ejection head. Discharge device. 12. The liquid ejection apparatus according to claim 11, wherein recording is performed by ejecting ink from the liquid ejection head and attaching the ink to a recording medium.