JP2000062179A - Liquid ejecting head, method for liquid ejection and liquid ejecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a refilling property of an ink jet head and to attain stability thereof by a method wherein an inertia force of a liquid in a staying condition is changed beforehand to be in a condition for contributing to the refilling. SOLUTION: In a liquid ejecting head, a liquid passage 10 having a bubble generating region 11 except an ejection nozzle 18 becomes a substantially closed space by virtue of the contact of a deformed movable member 31 with a stopper 64 and extinguishing of bubbles is started in the closed space condition. The movable member 31 is deformed such that it is elastically projected to an upstream side before becoming the maximum bubble volume and the projected section is deformed in the downstream side by the elastic force at the bubble contraction stage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid ejection head for ejecting a desired liquid by the generation of bubbles caused by the action of thermal energy on the liquid, a head cartridge using the liquid ejection head, and a liquid ejection device. In particular, the present invention relates to a liquid ejection head having a movable member that is displaced by utilizing the generation of bubbles, a head cartridge using the liquid ejection head, and a liquid ejection device.

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 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 No. 436047A1 discloses
The invention proposes to alternately open and close a first valve that shuts off the area near the ejection port and the bubble generating portion, and a second valve that shuts off the air bubble generating portion and the ink supply portion completely. (EP 436047A1 FIGS. 4-9). 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.
Regarding the improvement of the refill characteristics after the formation of a substantially closed space upstream due to the displacement of the movable member, we examined the preferable characteristics required for the movable member from the growth of the front part of the bubble to the start of defoaming. It was done by.

The present invention pays attention to the substantial liquid retention state on the upstream side with respect to the change of the ejection port side of the substantially closed space at the time of droplet ejection, and refills the inertial force of the fluid in this retention state. The purpose of this is to improve the refill characteristics of the inkjet head and ensure stability by changing the state in advance so that it can contribute to the.

[0016]

To achieve the above object, the present invention provides a heating element for generating thermal energy for generating bubbles in a liquid, and a discharge port for discharging the liquid. A liquid flow path that is in communication with the discharge port and has a bubble generation region for generating bubbles in the liquid; a cantilever-shaped movable member that is provided in the bubble generation region and is displaced as the bubble grows; A liquid ejecting head, comprising: a regulating unit that regulates a displacement of a member within a desired range, and ejecting the liquid from the ejection port by energy when the bubbles are generated, wherein the heating element and the ejection port are linear. While being in a communication state, the restriction portion is provided so as to face the bubble generation region of the liquid flow path, and the vicinity of the free end of the displaced movable member and the restriction portion are substantially in contact with each other. ,Previous The liquid flow path having a bubble generation region becomes a substantially closed space except for the discharge port, and the movable member is elastically displaced to a convex shape upstream before the maximum bubble volume, It is characterized in that the convex portion is displaced to the downstream side by the elastic force in the contracting stage.

Further, according to the present invention, a heating element for generating thermal energy for generating bubbles in the liquid, a discharge port for discharging the liquid, and the discharge port are connected to each other, and the bubble is bubbled in the liquid. A liquid flow path having a bubble generation region to be generated, a movable member provided in the bubble generation region and displaced with the growth of the bubbles, and a restriction portion for restricting displacement of the movable member within a desired range, A liquid ejection method using a liquid ejection head that ejects the liquid from the ejection port by energy when bubbles are generated, wherein the movable member substantially comes into contact with the restriction portion before the maximum foaming of the bubbles and the elasticity is increased. Of the liquid flow path having the bubble generation region to become a substantially closed space except for the discharge port, and the movable member is contracted at the bubble generation stage. Convex Part is characterized by having a, a step of displacing a downstream side in its elastic force.

Furthermore, the method further comprises the step of contracting the bubbles while the movable member is substantially in contact with the restriction portion.

Further, in the step of contracting the bubble while the movable member is substantially in contact with the regulating portion, most of the movement of the liquid due to the contraction of the bubble is directed in the upstream direction from the discharge port. The meniscus is rapidly drawn into the discharge port.

Further, during the bubble shrinking step, the movable member is separated from the regulating portion to generate a liquid flow in the bubble generating region in the downstream direction toward the discharge port, so that the meniscus is rapidly drawn. It is characterized by braking.

According to the above construction, the movable member is elastically displaced so as to be convex toward the upstream side before the maximum bubble volume, and the convex portion is displaced toward the downstream side by the elastic force in the bubble contraction stage. Therefore, before the main refill is started, the inertial force in the stationary state can be relaxed to enable the initial movement in the refill direction. As a result, refilling is performed stably and promptly, so that sufficient contribution can be made to droplet formation. Other effects of the present invention can be understood from the description of each embodiment.

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

Further, 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 restriction portion used in the present invention means that the movable member and the restriction portion are in direct contact with each other even in the proximity state in which a liquid of about several μm is interposed therebetween. Good.

[0025]

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

FIG. 1 is a sectional view of an embodiment of the liquid discharge head of the present invention taken along the liquid flow path, and shows the characteristic phenomena in the liquid flow path of (a) to (f). It is shown divided into steps.

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 thermal 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. At least a part of the movable member 31 is arranged in the liquid flow path 10 having the bubble generation region 11 so as to face the heating element 2. The movable member 31 has a free end 32 on the downstream side toward the discharge port 18, and is supported by a support member 34 arranged on the upstream side. In particular, in this embodiment, the free end 32 is arranged near the center of the bubble generation region 11 in order to suppress the growth of the upstream half of the bubble that affects the back wave to the upstream side and the inertial force of the liquid. 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.

FIG. 1A 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. The important thing here is
The movable member 31 is provided at a position facing the upstream half of the bubble generated by the heat generated by the heating element 2, and the stopper 64 for restricting the displacement of the movable member 31 has a bubble generation region 11 It is provided above the center of the. 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.

FIG. 1B shows a state in which a part of the liquid filling the bubble generating region 11 is heated by the heating element 2 and the bubbles 40 accompanying the film boiling grow to the maximum. At this time, the pressure wave based on the generation of the bubbles 40 propagates in the liquid flow path 10, and accordingly, the liquid moves to the downstream side and the upstream side with the central region of the bubble generation region as a boundary, and the bubbles 40 on the upstream side.
The movable member 31 is displaced by the flow of the liquid accompanying the growth of the liquid, and the discharge droplet 66 is being discharged from the discharge port 18 on the downstream side. Here, in the movement of the liquid toward the upstream side, that is, in the direction of the common liquid chamber 13, the resistance from the flow passage with respect to the movement of the liquid is lower than that on the downstream side, and the liquid is easily flown in the low flow passage. Although a large flow occurs due to the resistance region 65, when the movable member 31 is displaced until it comes close to or comes into contact with the stopper 64, further displacement is restricted, so that the movement of the liquid in the upstream direction is also largely restricted there. Accordingly, 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 receives a large amount of stress in the form of being pulled in the upstream direction. Furthermore, some of the bubbles 40, the growth of which is restricted by the movable member 31, pass through a slight gap between the side walls of the liquid flow path 10 and the side portion of the movable member 31, and rise to the upper surface side of the movable member 31. is doing. This raised bubble will be referred to as "raised bubble (41)" in the present specification.

In this state, the overall shape of the liquid flow path from the movable member 31 to the discharge port side is such that it widens from the upstream side to the downstream side.

In the present invention, as shown in FIG. 11, a "linear communication state" is maintained in which a straight flow passage structure is maintained with respect to the liquid flow between the discharge port side portion of the bubble 40 and the discharge port. 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 an influence on the discharge port side of bubbles are defined. Can be directly connected by a straight line. This is a state where the heating element, especially the downstream side of the heating element can be observed when viewed from the outside of the discharge port if there is no fluid in the flow path. Is.

On the other hand, as described above, since the displacement of the movable member 31 is restricted by the stopper 64 in the upstream portion of the bubble 40, the movable member 31 is projected to the upstream side by the inertial force of the liquid flow to the upstream side. It has a small size in a state that it stays until it is bent into shape and charged with stress. As a whole of this portion, the stopper portion, the liquid flow path partition wall 101, the movable member 31, and the fulcrum 33 have almost no amount of entering the upstream region. (However, a partially raised bubble in a space of 10 μm or less in the gap between the movable member 31 and the liquid flow path partition wall 101 is allowed.) The convex deflection amount is about 20 μm at the maximum and in a minute range. It is a thing.

As a result, the liquid flow to the upstream side is significantly restricted, and fluid crosstalk to the adjacent nozzles and liquid backflow and pressure oscillation in the supply path system that hinders high-speed refill described later are prevented.

FIG. 1C shows a state in which the negative pressure inside the bubbles overcomes the movement of the liquid to the downstream side in the liquid flow path after the film boiling described above, and the contraction of the bubbles 40 is started. 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. Generates a liquid moving force from the discharge port 18 in the upstream direction. In the state shown in FIG. 1B, the movable member 31 is in a stress-charged state in which the movable member 31 is curved in a convex shape toward the upstream side. Therefore, in FIG. 1C, as the movable member itself, the stress is released from the upstream side. A force is generated that pulls back the flow and makes a concave shape in the upstream direction. Therefore, from a certain point in time, the pulling force of the movable member from the upstream direction overcomes the above-described moving force of the liquid in the upstream direction, and a slight amount of flow starts from the upstream side to the discharge port side. Also, the bending is reduced, and the displacement to the concave shape starts in the upstream direction. That is, an unbalanced state occurs between the upstream side and the downstream side of the bubble 40, in which a total flow of liquid in the liquid flow path is unidirectionally directed toward the discharge port.

At the timing immediately after that, the movable member 31 and the stopper 64 which are still displaced in the entire liquid flow path.
A liquid flow path 1 having a bubble generation region 11 by contact with
Since 0 is a substantially closed space except for the ejection port 18, the contraction energy of the bubble 40 strongly acts as a force for moving the liquid in the vicinity of the ejection port 18 in the upstream direction as a total balance. Therefore, at this point, the meniscus M is largely drawn into the liquid flow path 10 from the ejection port 18, and the liquid column connected to the ejection 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. 1D shows a state in which the defoaming step is almost completed and the discharged droplet 66 and the meniscus M are separated. In the low flow path resistance region 65, due to the repulsive force of the movable member 31 and the contracting force of the bubble 40 defoaming against the moving force of the liquid in the upstream direction, the downward displacement of the movable member 31 and the accompanying low flow path resistance region 65 are caused. The flow in the downstream direction is started, and the proximity or contact state between the movable member 31 and the stopper 64 begins to open. Along with this, the flow in the downstream direction in the low flow path resistance region 65 has a small flow path resistance, so 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 remains outside the ejection port 18 or is a liquid column portion that is convex toward the ejection port 18. While taking in as little as possible, it starts returning to the position before foaming at a relatively low speed. In particular, the return flow of the meniscus M and the refill from the upstream merge to form a region where the flow velocity is almost zero between the discharge port 18 and the heater 2, so that the meniscus converges well. Although this depends on the viscosity and surface tension of the ink, according to the present invention, this liquid column separates and becomes a satellite and adheres to the printed matter to deteriorate the image quality, or adheres to the vicinity of the orifice and adversely affects the ejection direction. It is possible to drastically reduce the number of things that cause a discharge failure or cause a discharge failure.

Further, since the meniscus M itself also starts to recover before being largely drawn into the liquid flow path, the meniscus M can be recovered in a short time even if the liquid movement speed itself is not so large. Exit 1
The amount of the convex shape outward of the discharge port 18 without stopping at 8 is reduced, and the discharge port 1 generated subsequent to the overshoot
It is possible to finish the damped oscillation phenomenon with 8 as the convergence point in an extremely short time. Since this damped vibration phenomenon also adversely affects the printing quality, the present invention enables stable high-speed printing.

The movable member 31 and the stopper 6 described above are also provided.
The flow-in to the liquid flow path 10 through the portion between 4 is shown in FIG.
As shown in (d), since the flow velocity on the wall surface on the side of the top plate 50 is increased, extremely small bubbles and the like remain in this portion,
Contributes to the stability of ejection. On the other hand, some satellites 67 existing immediately after the ejected droplet 66 are very close to the ejected droplet due to the rapid meniscus drawing in FIG. The phenomenon of receiving the force attracted to the ejected droplet by the vortex, that is, a so-called slipstream phenomenon occurs.

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. Therefore, the satellite dots formed from the trailing portion become smaller, and the distance between the main droplet and the satellite dot becomes shorter. Furthermore, since the trailing portion does not continue to be pulled by the meniscus, the ejection speed does not decrease, and the satellite 67 is attracted by the so-called slipstream phenomenon behind the ejection droplet 66.

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
The liquid is moved in the direction in which the liquid 40 is drawn downward from the initial position by the completion of the defoaming process of the bubbles 40 and the displacement overshoot of the movable member 31 to draw the liquid from the upstream side and the discharge port 18.
This causes the phenomenon of the liquid being pushed in the direction. In addition, the cross-sectional area of the liquid flow path in which the stopper 64 is present is increased to increase the liquid flow in the direction of the discharge port 18 and accelerate the return of the meniscus M to the discharge port 18. As a result, the refill characteristics in this embodiment are dramatically improved.

Further, when cavitation occurs when bubbles disappear, the defoaming point and the discharge port 18 are separated by the downward displacement of the movable member 31, so that the shock wave due to cavitation is not directly transmitted to the discharge port 18 and the movable member 31. Since a large amount of light is absorbed by the cavitation, shock waves due to cavitation reach the meniscus, and minute droplets called microdots are hardly generated from the meniscus, but
The phenomenon that the microdots adhere to the printed matter to deteriorate the image quality, or the microdots adhere to the vicinity of the ejection port 18 to make the ejection unstable is drastically reduced.

Further, since the cavitation generation point due to defoaming is also shifted to the fulcrum 33 side by the movable member 31, the damage to the heater 2 is reduced. Further, the viscous ink is forcibly moved between the movable member 31 and the heater 2 and removed from this closed region, so that the ejection durability is improved. At the same time, due to the same phenomenon, the amount of burnt deposits on the heater in this region is reduced, and the ejection stability is improved.

FIG. 1F shows a state where the state of FIG. 1E has further advanced and the satellite 67 has been taken into the discharge 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 by the reaction of the overshoot.
This converges due to the 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, and finally stops at the initial position.

The upward displacement of the movable member 31 controls the flow of liquid from the common liquid chamber 13 side toward the discharge port 18,
The movement of the meniscus M quickly converges near the discharge port. Therefore, it is possible to greatly reduce the factors such as the overshoot phenomenon of the meniscus, which makes the ejection state unstable and deteriorates the printing quality.

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

FIG. 2 is a perspective perspective view of a part of the head shown in FIG. 1B, which basically shows the same state as FIG. 1B 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.

In addition, in the defoaming process of the bubbles 40, the raised bubbles 41 move 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.

As described above, in the liquid discharge head having the above-described structure, at the moment when the liquid is discharged from the discharge port due to the generation of bubbles, the discharged liquid droplets are discharged in a state close to a liquid column having a spherical portion at the tip. This is the same in the conventional head structure, but in the present invention, when the movable member is displaced by the bubble growing process and the displaced movable member comes into contact with the restriction portion,
A liquid flow path having a bubble generation region forms a substantially closed space except for the discharge port. Therefore, if the bubbles are defoamed in this state, the above-mentioned closed space is maintained until the movable member is separated from the regulation part by the defoaming, so most of the defoaming energy of the bubbles moves the liquid near the discharge port in the upstream direction. It will work as a force to move to. As a result, immediately after the start of defoaming of the air bubbles, the meniscus is rapidly drawn into the liquid flow path from the ejection port, and the tailing portion that is connected to the ejection droplet outside the ejection port and forms the liquid column is the meniscus. It is quickly separated with a stronger force. As a result, the satellite dots formed from the trailing portion become smaller, and the printing quality can be improved.

Furthermore, since the trailing portion is not continuously pulled by the meniscus, the discharge speed does not decrease,
Further, since the distance between the ejected droplet and the satellite dot is shortened, the satellite dot is attracted by the so-called slipstream phenomenon behind the ejected droplet. As a result, ejection droplets and satellite dots may be merged, and it is possible to provide a liquid ejection head having almost no satellite dots.

Furthermore, the present invention is characterized in that, in the above-mentioned head, the movable member is provided for suppressing only bubbles that grow in the upstream direction with respect to the flow of the liquid toward the ejection port. More preferably, the free end of the movable member is located substantially in the center of the bubble generating region. According to this configuration, it is possible to suppress the back wave to the upstream side due to bubble growth and the inertial force of the liquid, which are not directly related to the discharge of the liquid, and to direct the growth component of the bubble to the downstream side in the discharge port direction. It is possible.

Further, the present invention is characterized in that, in the above-described head, the flow path resistance of the liquid flow path on the side opposite to the ejection port with the restriction portion as a boundary is low. According to this configuration, since the movement of the liquid in the upstream direction due to the growth of the bubbles becomes a large flow due to the liquid flow path having the low flow path resistance, when the displaced movable member comes into contact with the restriction portion, the movable member moves upstream. It will be subjected to the stress of being pulled in the direction. As a result, even if defoaming is started in this state, a large amount of liquid moving force in the upstream direction due to the growth of bubbles remains, so for a certain period of time until the repulsive force of the movable member overcomes this liquid moving force.
The above-mentioned closed space can be maintained. That is, with this configuration, high-speed meniscus pull-in becomes more reliable. Also, when the bubble defoaming process progresses and the repulsive force of the movable member overcomes the liquid movement force in the upstream direction due to bubble growth, the movable member is displaced downward in an attempt to return to the initial state, which results in low flow resistance. Downstream flow also occurs in the region. The flow in the downstream direction in the low flow path resistance region has a small flow path resistance, so that it rapidly becomes a large flow and flows into the liquid flow path via the restriction portion. As a result, due to the liquid movement in the downstream direction toward the discharge port, the above-mentioned meniscus pull-in can be suddenly braked and the meniscus vibration can be converged at high speed.

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

<Movable Member> FIG. 3 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 3 μm. However, the material of the movable member is not limited to this, it has solvent resistance to the discharge liquid, and is movable. 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) is generated in the ink, and the action force based on this state change ejects the ink from the ejection port. In a conventional technique of an ink jet recording method for forming an image by adhering a recording medium onto a recording medium, that is, a so-called bubble jet recording method, as shown in FIG.
As shown in (1), it can be seen that there is a non-foaming effective region S that does not contribute to ink ejection, although the heating element area and the ink ejection amount are in a proportional relationship. 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 which effectively acts on the movable member.
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 distinguishing between the step of acting and the step of acting comprehensively, it is extremely important to arrange the movable member so that only the upstream side portion from the central region faces the movable member, I can say. In this embodiment,
Although the effective foaming area is set to be approximately 4 μm or more inside from the periphery of the heating element, it is not limited to this depending on the type of the heating element and the forming method.

Further, in order to favorably form the above-mentioned substantially closed space, it is preferable that the distance between the movable member and the heating element in the standby state is 10 μm or less.

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

5A and 5B are vertical sectional views of the liquid discharge head of the present invention. FIG. 5A shows a head having a protective film described later, and FIG. 5B 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 grooves 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. 5) and the electric resistance layer 105 (0.01 to 0.2 μm thick) and the wiring electrode 104 (0.2 to 1.0 μm thick) such as aluminum 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, pressure and shock waves generated at the time of bubble generation and defoaming are very strong, and the durability of a hard and brittle oxide film is remarkably reduced. Therefore, tantalum (Ta) of 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. 5B. 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 used. 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 portion 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 these liquids, as the liquid (recording liquid) used for recording, the ink having the composition used in the conventional bubble jet device can be used.

Further, it is possible to use 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,
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 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 was increased due to the improvement in the discharge force, the liquid was discharged. 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 Discharge Head> FIG. 7 is an exploded perspective view showing the overall structure of the liquid discharge head of the present invention.

An element substrate 1 provided with a plurality of heating elements 2 is arranged 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. 8 is a diagram for explaining this side shooter type head.

In FIG. 8, 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 is the liquid flow path 1 passing over the heating element 2.
It communicates with 0. A bubble generation region exists in a region near the surface where the heating element 2 contacts the liquid. Two movable members 31 are supported on the element substrate 1, 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 The heating elements 2 are located so as to face each other. In addition, each movable member 3
1 has 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. 8A shows a state in which a part of the liquid filling the bubble generating 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 discharge port 18 due to the pressure generated by the generation of the bubble 40, the movable members 31 are displaced by the growth of the bubble 40, and the discharge droplet 66 is about to fly out from the discharge port 18. 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. Street, movable member 31
Is raised on the upper surface side of. That is, the raised bubbles 41 are formed.

When the contraction of the bubble 40 is started after the film boiling, since a large force of the liquid in the upstream direction remains at this point, each movable member 31 is still in contact with the stopper 64, 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 in each low flow path resistance region 65 against the moving force of the liquid in the upstream direction.
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. 8B shows a liquid flow AB in the defoaming process of the bubbles 40. Liquid flow A is common liquid chamber 13
Shows the component that the liquid from flows through the upper surface (the surface opposite to the heating element) of the movable member 31 toward the discharge port 18, and the liquid flow B shows the component that flows on both sides of the movable member 31 and on the heating element 2. Shows.

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.

In addition, in the defoaming process of the bubbles 40, the raised bubbles 41 move 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.

<Liquid Ejecting Device> FIG. 9 shows a schematic structure of a liquid ejecting device equipped with the liquid ejecting head having the structure described with reference to FIGS. In this embodiment, an ink discharge recording apparatus using ink as a discharge liquid will be described in particular. A carriage HC of the liquid ejecting apparatus is equipped with a head cartridge to which a liquid tank section 90 containing ink and a liquid ejecting head section 200 can be attached and detached, and a recording medium such as a recording sheet conveyed by a recording medium conveying means is mounted. Recording medium 150
Moves back and forth in the width direction.

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

The recording apparatus receives print information from the host computer 300 as a control signal. 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 in the recorder and input to the CPU 302 which also serves as a head drive signal supply means. The CPU 302 processes the data input to the CPU 302 using a peripheral unit such as the RAM 304 based on a control program stored in the ROM 303,
Convert to 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 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.

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, etc. 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.

Further, as the ejection liquid used in these liquid ejection devices, a liquid suitable for each recording medium and recording conditions may be used.

[0101]

According to the present invention, before the main refill is started, the inertial force in the stationary state can be alleviated to enable the initial movement in the refill direction. As a result, refilling is performed stably and promptly, so that sufficient contribution can be made to droplet formation. Also, while suppressing the movement of the liquid in the upstream direction due to the back wave, that is, the pressure wave in the upstream direction, the meniscus is rapidly drawn into the ejection port to prevent satellite dots, stabilize the ejection amount, and improve the printing quality. Can be improved.

In particular, according to the present invention, the quick separation of the meniscus from the trailing portion which is connected to the ejected droplet to form the liquid column, achieves stabilization of the droplet and high quality recording. You can enable it.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of one embodiment of a liquid discharge head according to the present invention cut in the liquid flow channel direction, showing characteristic phenomena in the liquid flow channel in steps (a) to (f). It is shown separately.

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

3 shows another shape of the movable member shown in FIG.

FIG. 4 is a graph showing a relative relationship between a heating element area and an ink discharge amount.

5A and 5B are vertical cross-sectional views of a liquid ejection head of the present invention, in which FIG. 5A shows a protective film and FIG. 5B does not have a protective film.

FIG. 6 is a waveform diagram for driving a heating element used in the present invention.

FIG. 7 is an exploded perspective view showing the overall configuration of the liquid ejection head of the present invention.

FIG. 8 is a diagram for explaining a side shooter type head to which the liquid ejection method of the present invention is applied.

9 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 8. FIG.

FIG. 10 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.

FIG. 11 is a cross-sectional view of a flow path illustrating a “linear communication state”.

[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 41 Raised bubbles 50 top plate 64 stopper 65 Low flow resistance area 66 ejected drops 67 satellites 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

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoichi Tanetani             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Hiroyuki Sugiyama             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Sadayuki Sugama             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F term (reference) 2C056 EA01 EA04 FA03                 2C057 AF06 AF23 AG12 AG46 AG76                       BA03 BA13

Claims (15)

[Claims] 1. A heating element that generates thermal energy for generating bubbles in a liquid, a discharge port that discharges the liquid, and a bubble that communicates with the discharge port and generates bubbles in the liquid. A liquid flow path having a generation region, a cantilever-shaped movable member that is provided in the bubble generation region and is displaced as the bubble grows, and a restriction unit that restricts the displacement of the movable member within a desired range. A liquid ejection head for ejecting the liquid from the ejection port by the energy when the bubbles are generated, wherein the restricting portion is provided so as to face the bubble generation region of the liquid flow path, and the displaced movable member By substantially contacting the vicinity of the free end and the regulation portion, the liquid flow path having the bubble generation region becomes a substantially closed space except the discharge port, and the movable member has a maximum bubble volume. Since Elastically displaced so as to be convex on the upstream side, the liquid discharge head that convex portion, characterized in that the displaced downstream in its elastic force in the bubble shrinkage stage. 2. The liquid ejection head according to claim 1, wherein the heating element and the ejection port are in linear communication with each other. 3. The liquid ejection head according to claim 1, wherein the movable member is provided to suppress only bubbles that grow in an upstream direction with respect to the flow of the liquid toward the ejection port. 4. The liquid ejection head according to claim 1, wherein the movable member has a free end, and the free end is located substantially in the center of the bubble generation region. 5. The flow path resistance of the liquid flow path during standby of the movable member is lower on the upstream side than on the downstream side with the restriction portion as a boundary. Liquid ejection head. 6. The liquid ejection head according to claim 4, wherein the movable member is brought into contact with the restriction portion near the free end. 7. The liquid ejection head according to claim 1, wherein the restriction portion is formed by partially reducing a distance of the liquid flow path from the movable member. 8. The liquid ejection head according to claim 1, wherein the ejection port is provided above the heating element. 9. A plurality of the movable members are formed for one heating element, and the plurality of movable members are formed so as to be symmetrical with respect to a foaming center of the heating element. The liquid ejection head according to claim 8. 10. A heating element that generates thermal energy for generating bubbles in a liquid, a discharge port that discharges the liquid, and a bubble that communicates with the discharge port and generates bubbles in the liquid. A liquid flow path having a generation region, a movable member that is provided in the bubble generation region and is displaced as the bubble grows, and a regulation unit that regulates the displacement of the movable member within a desired range. Is a liquid discharge method using a liquid discharge head that discharges the liquid from the discharge port by the energy of, wherein the movable member substantially comes into contact with the restriction portion before the maximum foaming of the bubbles and is elastically upstream. A step of displacing so that the liquid flow path having the bubble generation region becomes a substantially closed space except for the discharge port, and a convex shape of the movable member in the step of contracting the bubbles. The department Liquid discharging method characterized by having the steps of displaced downstream in sexual power. 11. The liquid ejection method according to claim 10, further comprising a step of contracting the bubbles while the movable member is substantially in contact with the restriction portion. 12. In the step of contracting the bubble while the movable member is in contact with the restriction portion, most of the movement of the liquid accompanying the contraction of the bubble is directed in the upstream direction from the ejection port, and inside the ejection port. The liquid ejecting method according to claim 11, wherein the meniscus is rapidly drawn into. 13. During the bubble shrinking step, the movable member is separated from the restricting portion to generate a liquid flow in a downstream direction toward the discharge port in the bubble generating region, and the meniscus is suddenly braked. The liquid discharging method according to claim 12, wherein 14. A liquid ejecting head according to claim 1, and a recording medium conveying unit that conveys a recording medium that receives the liquid ejected from the liquid ejecting head. Liquid ejector. 15. The liquid ejecting apparatus according to claim 14, wherein recording is performed by ejecting ink from the liquid ejecting head and adhering the ink to the recording medium.