JP3535817B2 - Liquid discharge method, liquid discharge head, 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, a liquid ejecting head and a liquid ejecting apparatus for ejecting a liquid by causing thermal energy to act on the liquid to generate bubbles.

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 Conventionally, in a recording device such as a printer, energy such as heat is applied to liquid ink in a flow channel to generate bubbles, and the ink is ejected from an ejection port by an action force based on a sharp volume change accompanying the bubble. Then, an ink jet recording method, which is a so-called bubble jet (registered trademark) recording method, in which an image is formed by adhering this onto a recording medium, is 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, a flow path communicating with this ejection port, An electrothermal converter as an energy generating means for ejecting the ink arranged in the flow path is generally arranged.

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 is applied to products in various fields, various demands are increasing,
For example, 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 is possible based on stable bubble generation. From the point of view, there has been proposed an improved flow passage shape in order to obtain a liquid discharge head having a high filling (refill) speed of the discharged liquid into the liquid flow passage. Among these, in a head that generates bubbles in the nozzle and discharges liquid as the bubbles grow, bubble growth in the direction opposite to the discharge port and the resulting liquid flow are factors that reduce discharge energy efficiency and refill characteristics. A known invention of a structure that improves such ejection energy efficiency and refill characteristics is proposed in European Patent Application Publication EPO436047Al.

In the invention described in this publication, the first valve for shutting off the area near the discharge port and the bubble generating portion and the portion for completely shutting off the air bubble generating portion and the ink supply portion are provided. It alternately opens and closes two valves (EP43604).
7Al (FIGS. 4-9). For example, in the example of FIG. 7 of the publication,
As shown in FIG. 37, the heating element 110 is provided in the approximate center of the ink flow passage 112 between the ink tank 116 and the nozzle 115 on the substrate 125 forming the inner wall of the ink flow passage 112. The heating element 110 is provided inside the ink flow path 112.
It is in a compartment 120 which is closed all around. Ink flow path 11
2 is a substrate 125, thin films 123 and 126 directly laminated on the substrate 125, and tongue-like pieces 113 and 13 as closing bodies.
It is composed of 0 and. The open tongue is shown in broken lines in FIG. Another thin film 123 that extends in a plane parallel to the substrate 125 and terminates at the stopper 124 shields the ink flow path 112. When bubbles are generated in the ink, the free end of the tongue 130 in the nozzle area, which rests in close contact with the stopper 126, is displaced upwards and the ink liquid is discharged from the compartment 120 into the ink flow path 112. It is then injected through the nozzle 115. At this time, since the tongue-shaped piece 113 provided in the area of the ink tank 116 is in close contact with the stopper 124 in a stationary state, the partition 12
The ink liquid in 0 does not go to the ink layer 116.
When the air bubbles in the ink disappear, the tongue 130 is displaced downward and comes into close contact with the stopper 126 again. Then, the tongue 113 falls down into the ink compartment 120, so that the ink liquid flows into the compartment 120.

[0008]

However, EP4360.
In the invention described in 47Al, since the three regions of the vicinity of the discharge port, the bubble generation part, and the ink supply part are divided into two, the ink that follows the droplet becomes a large trail during discharge, The number of satellite dots is considerably larger than that of the normal ejection method of growing, shrinking, and defoaming (it is presumed that the meniscus receding effect due to defoaming cannot be used). In addition, the valve on the discharge port side of the bubbles causes a great loss of discharge energy. Further, at the time of refilling (when ink is refilled into the nozzle), the liquid is supplied to the bubble generation portion with defoaming, but the liquid cannot be supplied to the area near the discharge port until the next foaming occurs. Is not a practical level because the ejection response frequency is extremely small.

The present invention provides an epoch-making method and head structure for improving the efficiency of suppressing the bubble growth component in the direction opposite to the discharge port and satisfying the contradictory improvement of the efficiency of refill characteristics. The present invention proposes an invention satisfying the improvement of ejection efficiency based on a new idea to be found.

As a result of earnest research, the present inventors have developed a special check valve in a nozzle structure of a liquid discharge head that generates bubbles in a linear nozzle and discharges liquid as the bubbles grow. It was found that the function suppresses bubble growth in the direction opposite to the ejection port (rearward), and the ejection energy to the rear can be effectively used on the ejection port side. Besides, by suppressing the bubble growth component to the rear by the function of a special check valve, and improving the efficiency of refill characteristics,
It has been found that the ejection response frequency can be made extremely high.

That is, an object of the present invention is to simultaneously improve the ejection power and the ejection frequency by a nozzle structure and an ejection method using a novel valve function, and achieve a high speed and high image quality which cannot be achieved in the past. It is to establish a new ejection method (structure) for achieving the head.

[0012]

According to the liquid ejection method of the present invention obtained in the above-described polishing process, a plurality of ejection ports for ejecting the liquid and one end of each ejection port are always in communication with each other. A plurality of liquid flow paths having a bubble generation region for generating bubbles in the liquid, a bubble generation means for generating energy for generating and growing the bubbles, and each of the plurality of liquid flow paths are provided, The movable member has a plurality of liquid supply ports communicating with a common liquid supply chamber, and a movable member having a free end, which is supported with a minute gap with respect to the liquid flow path side of the liquid supply port. A liquid discharge method of a liquid discharge head, wherein a region surrounded by at least a free end portion and both side portions that reach the free end portion is larger than an opening region of the liquid supply port with respect to the liquid flow path, Drive voltage is applied Et al, wherein until a period in which the whole of the bubble is growing substantially isotropic terminated by the bubble generating means, have a period in which the movable member is substantially shut off by sealing the liquid supply port, wherein The discharge port side of the bubble generation area
Let Tf be the lifetime of the bubbles that grow in
Life tie of bubbles growing on the liquid supply port side of the raw area
When the frame is Tr, the relationship of Tf> Tr is always established .

Further, in the above liquid discharging method, the period in which the movable member hermetically closes the opening region and substantially shuts it off, at least the period in which the entire bubble is substantially isotropically grown by the bubble generating means ends. It is characterized by being continued until.

Further, after the period in which the movable member seals the opening area to substantially block the opening area, while the portion of the bubbles generated by the bubble generating means on the discharge port side is growing, Liquid supply from the common liquid supply chamber to the liquid flow path starts displacement from the position where the movable member seals the opening area and substantially cuts off to the bubble generating means side in the liquid flow path. It is characterized by enabling.

Further, in the liquid discharging method of the present invention, the movable member hermetically closes the opening area and substantially blocks the opening area, and thereafter, a portion of the bubbles generated by the bubble generating means on the discharge port side grows. While moving, the movable member starts displacing toward the bubble generating means side in the liquid flow path from a position where the movable member is closed and substantially closed, and the liquid is discharged from the common liquid supply chamber. It is characterized in that the liquid can be supplied to the flow channel.

Further, in the above liquid discharging method, after the movable member starts to be displaced toward the bubble generating means side in the liquid flow path from a position where the movable member hermetically closes the opening area and substantially blocks the opening area, While the part on the movable member side is contracting, the movable member is further displaced to the bubble generating means side to supply the liquid from the common liquid supply chamber to the liquid flow path.

Further, the discharge port side and the liquid supply port side in the bubble generation region are characterized in that the growth volume change of the bubble and the time from bubble generation to bubble disappearance are greatly different.

The bubble generating region is not exposed to the atmosphere.

[0019]

[0020]

In these liquid discharge heads, it is preferable that the movable member also has a gap with a liquid passage wall forming the liquid passage.

Further, the liquid discharge head of the present invention has a plurality of discharge ports for discharging the liquid, and a plurality of liquid discharge regions each having one end constantly communicating with each of the discharge ports and having a bubble generation region for generating bubbles in the liquid. A flow path, a bubble generating means for generating energy for generating and growing the bubbles, a plurality of liquid supply ports respectively disposed in the plurality of liquid flow paths and communicating with a common liquid supply chamber, and the liquid A movable member having a free end, which is supported with a minute gap with respect to the liquid flow path side of the supply port, and an area surrounded by at least the free end portion of the movable member and both side portions continuous with the free end portion. It is larger than the opening region of the liquid supply port with respect to the liquid flow path, and is a period during which the entire bubble is substantially isotropically grown by the bubble generating unit after the driving voltage is applied to the bubble generating unit. By the end Generated by the bubble generating means after a period in which the movable member seals and substantially blocks the liquid supply port, and the movable member seals and substantially blocks the opening region While the portion of the formed bubbles on the side of the discharge port is growing, the movable member is moved from the position where the movable member is closed to substantially close the opening region to the bubble generating means side in the liquid flow path. A liquid ejection head which starts displacement and is capable of supplying liquid from the common liquid supply chamber to the liquid flow path, wherein a maximum volume of bubbles growing on the ejection port side of the bubble generation region is Vf. and then, the when the volume of the maximum bubble growing in said liquid supply port side of the bubble generating region and Vr, always <br/> Ri elevational Chi relationship Vf> Vr, and the bubble generation Yoriyukiiki Growth on the outlet side
Let the lifetime of the bubbles be Tf,
The lifetime of bubbles growing on the liquid supply port side of
If r, then the relationship of Tf> Tr is always established .

[0023]

The defoaming point of the bubble is located closer to the discharge port than the center of the bubble generation region.

[0025]

[0026]

[0027]

Further, in the liquid discharge head as described above, the root support portion integrally formed with the movable member supporting the root of the movable member fixes the height position of the movable member to the root support portion. It is preferable that the movable member has a step so as to be displaced by one step with respect to the position, and the thickness of the movable member is larger than the amount of the step.

Further, a gap α between the opening end of each of the liquid flow paths of the liquid supply port and the side surface of the liquid supply port of the movable member, and the opening end of the liquid supply port on the liquid flow path side. It is preferable that the relationship with the overlapping width W3 in the width direction of the movable member, which overlaps with, is W3> α.

Furthermore, the relationship between the overlap width W4 of the movable member in the discharge port direction and the overlap width W3 of the movable member in the width direction, which overlaps with the opening end of the liquid supply port on the liquid flow path side. Is preferably W3> W4.

The present invention also provides a liquid ejecting apparatus comprising a liquid ejecting head having the above-described structure, and a recording medium conveying means for conveying a recording medium that receives the liquid ejected from the liquid ejecting head. To do. In this liquid ejecting apparatus, it is conceivable that ink is ejected from the liquid ejecting head and recording is performed by attaching the ink to the recording medium.

[0032]

[0033]

In the structure described above, the liquid flow path is immediately immediately after the drive voltage is applied to the bubble generating means and before the period during which the entire bubble is isotropically grown by the bubble generating means ends. Since the communication state between the liquid supply port and the liquid supply port is blocked by the movable member, the pressure wave due to bubble growth in the bubble generation region does not propagate to the liquid supply port side and the common liquid supply chamber side, and most of it is on the discharge port side. The discharge power is dramatically improved. In addition, even when using a high-viscosity recording liquid to fix it on recording paper at high speed or to eliminate bleeding at the boundary between black and color, the ejection power can be dramatically improved. Good ejection is possible. In addition, when the environment changes at the time of recording, especially in a low temperature and low humidity environment, the ink thickening area may increase at the ejection port and the ink may not be ejected normally at the start of use, but in the present invention, good ejection can be performed from the first shot. . Further, since the ejection power is dramatically improved, it is possible to reduce the size of the heating element used as the bubble generating means and reduce the energy input for ejection.

Further, the movable member is displaced downward due to the contraction of the bubbles, and the liquid rapidly becomes a large flow into the liquid flow path from the common liquid supply chamber through the liquid supply port. As a result, the flow that rapidly draws the meniscus M into the liquid flow path suddenly decreases, and the amount of retreat of the meniscus at the ejection port after the droplet ejection has decreased. As a result, the time it takes for the meniscus to return to its initial state after ejection is very short, that is,
Since a fixed amount of ink replenishment (refill) to the liquid flow path is completed in a short time, the ejection frequency (driving frequency) can be dramatically improved when highly accurate (constant) ink ejection is performed.

Further, since the bubble growth in the bubble generation region largely grows toward the ejection port side and suppresses the growth toward the liquid supply port side, the defoaming point is from the vicinity of the center of the bubble generation region to the ejection port. Since the defoaming force can be reduced while being located in the side portion and maintaining the foaming power, it is possible to greatly improve the mechanical and physical destruction life of the heating element due to the defoaming force in the bubble generation region.

Further, the root support portion integrally formed with the movable member supporting the root of the movable member shifts the height position of the movable member by one step with respect to the fixed position of the root support portion, By having the step, the stress concentration on the fixed position of the root support portion of the movable member is alleviated when the movable member is displaced. Further, since the thickness of the movable member is larger than the step amount of the root supporting portion of the movable member, stress concentration concentrated on the step portion of the root supporting portion of the movable member when the movable member is displaced is relaxed. You can
The durability of the base of the movable member is improved.

Further, the gap α between the liquid flow port side opening end of the liquid supply port and the liquid supply port side face of the movable member overlaps the liquid supply port side liquid flow port side opening end of the movable member. By setting the relationship with the overlap width W3 in the width direction to be W3> α, the flow resistance with respect to the flow from the liquid flow path to the liquid supply port side becomes larger than that when the relationship is W3 ≦ α, and foaming occurs. It is possible to effectively suppress the flow from the liquid flow path to the liquid supply port side in the initial bubble growth. Moreover, since the inflow of the liquid supply channel from the liquid flow path through the gap between the movable member and the periphery of the liquid supply port is effectively suppressed, the liquid supply port can be reliably and promptly shielded by the movable member. . Due to these things, the ejection efficiency is further improved.

Further, the relationship between the overlap width W4 of the movable member overlapping the opening end of the liquid supply port on the liquid flow path side in the discharge port direction and the overlap width W3 of the movable member in the width direction is W3> W4. As a result, when the movable member that has been displaced upward to the liquid supply port side due to initial foaming starts to be displaced downward to the bubble generating means side in the defoaming process, the free end tip of the movable member and the opening end of the liquid supply port are Since the contact width becomes smaller,
The frictional force generated there is also reduced, and the liquid supply port is preferentially opened from the free end side of the movable member. As a result, the liquid supply port can be reliably and promptly opened by the movable member. As a result, the liquid flow path is refilled more efficiently, and the ejection characteristics are further stabilized.

Further, by adopting an amorphous alloy thin film as the cavitation resistant film of the outermost surface layer of the bubble generating means, it is possible to further greatly improve the mechanical / physical breakdown life.

By adopting the amorphous alloy in the manufacturing process of the liquid discharge head of the present invention, A
Even in the removal process of removing the l film to form the liquid flow path and the liquid supply port, the damage to the underlying wiring layer can be greatly reduced and the yield can be improved.

Other effects of the present invention can be understood from the description of each embodiment. It should be noted that the terms “upstream” and “downstream” used in the description of the present invention refer to a liquid flow direction from a liquid supply source to a discharge nozzle via a bubble generation region (or a movable member), or a direction in this configuration. It is expressed as an expression.

The "downstream side" of 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.

The "overlap width" refers to the shortest distance from the opening edge of the liquid supply port on the liquid flow path side to the edge of the movable member.

In addition, the expression "the movable member seals the liquid supply port to substantially cut off the liquid supply port" in the present invention does not necessarily mean that the movable member is in close contact with the peripheral portion of the liquid supply port. It includes approaching the liquid supply port infinitely.

[0046]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
3 is a sectional view taken along one liquid flow path direction of the liquid ejection head according to the embodiment of the present invention, FIG. 2 is a sectional view taken along line XX ′ of FIG.
FIG. 2 is a sectional view taken along the line YY ′ in FIG.

In the liquid ejection head of the plural liquid passage-common liquid chamber form shown in FIGS. 1 to 3, the element substrate 1 and the top plate 2 are fixed in a laminated state via the liquid passage side wall 10, and both plates 1, A liquid flow path 3 having one end communicating with the discharge port 7 is formed between the two. Many liquid channels 3 are provided in one head.

Further, the element substrate 1 is provided with a heating element 4 such as an electrothermal conversion element as a bubble generating means for generating bubbles in the liquid replenished in the liquid flow path 3 for each liquid flow path 3. ing. In a region near the surface where the heating element 4 contacts the discharge liquid, there is a bubble generation region 11 in which the heating element 4 is rapidly heated to cause foaming in the discharge liquid.

A liquid supply port 5 formed in the supply portion forming member 5A is provided in each of the plurality of liquid flow paths 3, and a large-volume common liquid supply chamber 6 that communicates with each liquid supply port 5 at the same time is provided. Has been. That is, the single common liquid supply chamber 6 is branched into a large number of liquid flow paths 3, and an amount of liquid commensurate with the liquid discharged from the discharge ports 7 communicating with each liquid flow path 3 is shared by the common liquid supply chamber 6. Received from the liquid supply chamber 6.

The movable member 8 is provided between the liquid supply port 5 and the liquid flow path 3 substantially parallel to the opening region S of the liquid supply port 5 with a minute gap α (for example, 10 μm or less). Has been. The movable member 8 is also positioned substantially parallel to the element substrate 1 with respect to the element substrate 1. The end portion 8B of the movable member 8 on the ejection port 7 side is a free end located on the heating element 4 side of the element substrate 1. The root support portion 8C that supports the root of the movable member 8 is formed integrally with the movable member 8, and the root support portion 8C connects a plurality of movable members 8 aligned in the direction intersecting the plurality of liquid paths in common. It is a part to support. Reference numeral 8A in FIGS. 1 and 3 indicates the root of each of the plurality of movable members 8 supported by the root supporting portion 8C, and this serves as a fulcrum when each movable member 8 is displaced. The root support portion 8C of the movable member 8 is joined and fixed on the fixed member 9. Further, the fixing member 9 closes the end of the liquid flow path 3 opposite to the discharge port 7. Further, a part of the root support portion 8C of the movable member 8 described above is not joined (unfixed) to the fixed member 9, and this unjoined portion makes the height position of the movable member 8 the root support portion. 8C has a step so as to be offset by one step with respect to the surrounding portion with the fixing member 9. With this configuration, when the movable member 8 is displaced, stress concentration on the joint interface between the root support portion 8C of the movable member 8 and the fixed member 9 is relaxed.

Further, in the present embodiment, the region surrounded by at least the free end of the movable member 8 and the both sides continuous with it is larger than the opening region S of the liquid supply port 5 (see FIG. 3), and There is a minute gap β between the side part of the movable member 8 and each of the flow path side walls 10 on both sides (FIG. 2).
reference). The above-mentioned supply portion forming member 5A is disposed with respect to the movable member 8 via a gap γ as shown in FIG. The gaps β and γ differ depending on the pitch of the flow paths, but if the gap γ is large, the movable member 8 can easily block the opening region S and the gap β
Is larger, the movable member 8 is more likely to move to the element substrate 1 side with defoaming than in the steady state positioned via the gap α. In this embodiment, the gap α is 2 μm and the gap β is 3 μm.
m and the gap γ were 4 μm. In addition, the movable member 8 has a width Wl larger than the width W2 of the opening region S in the width direction between the flow path side walls 10, and has a width that can sufficiently seal the opening region S. In the present embodiment, as shown in FIGS. 2 and 3, the thickness of the portion of the supply portion forming member 5A along the movable member 8 is set to be smaller than the thickness of the liquid channel falling wall 10 itself. The supply portion forming member 5A is laminated on the flow path side wall 10. In addition, the discharge port 7 side of the movable member forming member 5A with respect to the free end 8B of the movable member is set to have the same thickness as the thickness of the liquid passage side wall 10 itself as shown in FIG. As described above, the movable member 8 can be moved in the liquid flow path 3 without frictional resistance, while the displacement toward the opening region S can be restricted in the peripheral portion of the opening region S. Thereby, the movable member 8
Can substantially block the opening region S to prevent the liquid flow from the inside of the liquid flow path 3 to the common liquid supply chamber 6, while the movable member 8 is kept in a substantially closed state due to the defoaming of bubbles. It becomes possible to move to the refillable state.

The opening area S mentioned here is a substantial area for supplying the liquid from the liquid supply port 5 toward the liquid flow path 3. In this embodiment, as shown in FIGS. It is a region surrounded by three sides of the mouth 5 and the end portion 9A of the fixing member 9.

Further, as shown in FIG. 4, in the present embodiment, there is no obstacle such as a valve between the heating element 4 as the electrothermal converter and the discharge port 7, and the linearity with respect to the liquid flow is provided. It is in a "linear communication state" that maintains the flow path structure. It is more preferable that the ejection direction such as ejection direction and ejection speed of ejected droplets is set by linearly matching the propagation direction of the pressure wave generated when bubbles are generated and the accompanying flow direction of liquid and ejection direction. It is desirable to create the ideal state of stabilization at a very high level. In the present invention, as one definition for achieving or approximating this ideal state, the discharge port 7 and the heating element 4, particularly the discharge port side (downstream side) of the heating element having an influence on the discharge port side of the bubbles, 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. (See FIG. 4).

Next, the ejection operation of the liquid ejection head of this embodiment will be described in detail. 5 to 7 are shown in FIGS.
In order to explain the ejection operation of the liquid ejection head having the structure shown in FIG. 5, the liquid ejection head is shown in a cutaway view along the liquid flow path direction, and the characteristic phenomenon is divided into 6 steps of FIGS. It is shown. Further, in FIGS. 5 to 7, the symbol M represents a meniscus formed by the discharge liquid.

FIG. 5 (a) shows a state before energy such as electric energy is applied to the heating element 4 and shows a state before the heating element generates heat. In this state, there is a minute gap (10 μm or less) between the movable member 8 provided between the liquid supply port 5 and the liquid flow path 3 and the surface on which the liquid supply port 5 is formed.

FIG. 5B shows a state in which a part of the liquid filling the liquid flow path 3 is heated by the heating element 4, film boiling occurs on the heating element 4, and the bubble 21 isotropically grows. Here, "isotropic bubble growth" means that the bubble growth rates in the normal direction of the bubble surface are almost equal at any position on the bubble surface.

In the isotropic growth process of the bubbles 21 in the initial stage of foaming, the movable member 8 is in close contact with the peripheral portion of the liquid supply port 5 to close the liquid supply port 5, and the inside of the liquid flow path 3 is the discharge port 7. Except for, it becomes a substantially sealed state. In this closed state, the bubbles 21
Is maintained for some period of the isotropic growth process. The period in which the sealed state is maintained may be from the time when the drive voltage is applied to the heating element 4 to the time when the isotropic growth process of the bubbles 21 is completed. Further, in this closed state, the inertance (the difficulty in moving when the stationary liquid suddenly starts moving) from the center of the heating element 4 in the liquid flow path 3 becomes substantially infinite. At this time, the inertance from the heating element 4 to the liquid supply port side approaches infinity as the distance between the heating element 4 and the movable member 8 increases. Further, at this time, the amount by which the free end of the movable member 8 is displaced toward the liquid supply port 5 side is hl.

FIG. 6A shows a state where the bubble 21 continues to grow. In this state, as described above, the inside of the liquid flow path 3 is substantially sealed except for the discharge port 7, so that the liquid does not flow to the liquid supply port 5 side. Therefore, the bubbles can largely spread to the ejection port 7 side, but do not spread very much to the liquid supply port 5 side. Then, the bubble growth continues on the ejection port 7 side of the bubble generation region 11, but conversely, the bubble growth stops on the liquid supply port 5 side of the bubble generation region 11. That is, this bubble growth stopped state is the maximum bubbling state on the liquid supply port 5 side of the bubble generation region 11. The foaming volume at this time is Vr.

Here, FIGS. 5 (a), 5 (b) and 6
The bubble growth process in (a) will be described in detail with reference to FIG. When the heating element is heated as shown in FIG. 8 (a), initial boiling occurs on the heating element, and then, as shown in FIG. 8 (b), it changes into film boiling in which film-like bubbles cover the heating element. . Then, the bubbles in the film boiling state continue to grow isotropically as shown in FIGS. 8B and 8C (the state where the bubbles are growing isotropically in this manner is called a semi-plow state). ). However, as shown in FIG.
When it becomes a substantially sealed state except for, the liquid cannot be moved to the upstream side, so some of the bubbles on the upstream side (liquid supply port side) cannot grow much in the semi-puro-like bubbles, and the remaining downstream The side (ejection port side) part grows greatly. This state is shown in FIG. 6 (a), FIG. 8 (d),
(E).

For convenience of description, a region where bubbles do not grow on the heating element 4 when the heating element 4 is heated is referred to as a B region, and a region on the ejection port 7 side where the bubbles grow is referred to as an A region. In the region B shown in FIG. 8 (e), the foam volume is the maximum, and the foam volume at this time is Vr.

Next, FIG. 6 (b) shows a state in which bubble growth continues in region A and bubble contraction begins in region B. In this state, in the area A, the bubbles grow largely toward the ejection port side, and in the area B, the volume of the bubbles starts to decrease. Then, the free end of the movable member 8 is displaced downward to the steady-state position by the restoring force due to its rigidity and the defoaming force of the bubbles in the B region, and is held. As a result, the liquid supply port 5 opens,
The common liquid supply chamber 6 and the liquid flow path 3 are in communication with each other.

FIG. 7A shows a state in which the bubble 21 has grown to the maximum extent. In this state, the bubbles grow to the maximum in the area A, and the bubbles in the area B almost disappear accordingly. The maximum bubble volume in the area A at this time is Vf
And In addition, the ejection droplet 22 that is ejecting from the ejection port 7
Is still connected to the meniscus M with a long tail.

In FIG. 7B, the growth of the bubble 21 is stopped and only the defoaming step is performed.
Indicates a state in which is divided. Immediately after the bubble growth is changed to the defoaming in the region A, the contraction energy of the bubble 21 acts as a force for moving the liquid in the vicinity of the ejection port 7 in the upstream direction as a whole balance. Therefore, the meniscus M is drawn into the liquid flow path 3 from the discharge port 7 at this time, and the liquid column connected to the discharge droplet 22 is quickly separated with a strong force. On the other hand, the movable member 8 is displaced downward due to the contraction of the bubbles, and the liquid rapidly flows into the liquid flow path 3 from the common liquid supply chamber 6 through the liquid supply port 5. As a result, the flow that rapidly draws the meniscus M into the liquid flow path 3 suddenly decreases, and the amount of retreat of the meniscus M decreases, and the meniscus M begins to return to the pre-foaming position at a relatively low speed. As a result, the convergence of the vibration of the meniscus M is very good as compared with the liquid ejection method that does not include the movable member according to the present invention. The amount by which the free end of the movable member 8 at this time is maximally displaced toward the bubble generating region 11 is h2.

Finally, when the bubbles 21 are completely extinguished, the movable member 8 also returns to the steady state position shown in FIG. 5 (a). To this state, the movable member 8 is displaced upward due to its elastic force (in the direction of the solid line arrow in FIG. 7B). Further, in this state, the meniscus M has already returned near the ejection port 7.

Next, the correlation between the time change of the bubble volume and the behavior of the movable member in the areas A and B in FIGS. 5 to 7 will be described with reference to FIG. FIG. 9 is a graph showing the correlation, and a curve A shows the time change of the bubble volume in the A region, and a curve B shows the time change of the bubble volume in the B region.

As shown in FIG. 9, the change over time in the growth volume of bubbles in the region A draws a parabola having a maximum value. That is,
From the start of foaming to the defoaming, the bubble volume increases with the passage of time, reaches a maximum at a certain point, and then decreases. On the other hand, in the B region, the time required from the start of foaming to the defoaming is shorter, the maximum growth volume of the bubbles is smaller, and the time to reach the maximum growth volume is shorter than in the A region. That is, in the A region and the B region, the time required from the start of foaming to the defoaming and the change in the growth volume of the bubbles are significantly different, and the B region is smaller.

In particular, in FIG. 9, since the bubble volume increases with the same time change in the initial stage of bubble generation, the curve A and the curve B overlap. That is, in the initial stage of bubble generation, a period during which the bubble isotropically grows (semi-puro state) occurs.
Then, although the curve A draws a curve that increases to the maximum point, the curve B branches from the curve A at some point and draws a curve in which the bubble volume decreases. That is, there is a period (partial growth partial contraction period) in which the bubble volume increases in the region A, but decreases in the region B.

On the basis of the above bubble growth method, in the form in which the free end of the movable member covers a part of the heating element as shown in FIG. 1, the movable member behaves as follows. That is, during the period shown in FIG. 9, the movable member is displaced upward toward the liquid supply port. In the period shown in the figure, the movable member is in close contact with the liquid supply port, and the inside of the liquid flow path is substantially sealed except for the discharge port. The start of this closed state is performed during the period when the bubbles are isotropically growing. Next, in the period shown in the figure, the movable member is displaced downward toward the steady state position. The opening of the liquid supply port by the movable member is started after a lapse of a certain time from the start of the partial growth partial contraction period. Next, in the period shown in the figure, the movable member is further displaced downward from the steady state. Next, in the period shown in the figure, the downward displacement of the movable member is almost stopped, and the movable member is in the equilibrium state at the open position. Finally, in the period shown in the figure, the movable member is displaced upward toward the steady state position.

The correlation between the bubble growth and the behavior of the movable member is influenced by the relative position between the movable member and the heating element. Therefore, with reference to FIGS. 10 and 11, the correlation between bubble growth and the behavior of the movable member in the liquid ejection head including the movable member and the heating element at the relative positions different from the present embodiment will be described.

FIG. 10 is a diagram for explaining the correlation between bubble growth and the behavior of the movable member in the form in which the free end of the movable member covers the entire heating element, and FIG.
(B) has shown the graph of the correlation. When the overlapping area of the heating element and the movable member is large as in the configuration shown in FIG. 10A, the period of FIG. 10 becomes shorter than that of the configuration of FIG. 1, and the heating element is not heated. Since the airtight state is achieved within a short time after the start, it is possible to further improve the ejection efficiency. The behavior of the movable member in each of the periods from to in FIG. 10 is the same as the fist movement described with reference to FIG. Further, when the form of FIG. 10 is adopted, the movable member is easily affected by the decrease in the volume of the bubbles. Therefore, as can be seen from the start of the period in the same figure, the opening of the liquid supply port by the movable member is performed during the partial growth partial contraction period. Immediately from the start. That is,
The opening timing of the movable member is earlier than in the case of the configuration of FIG. For the same reason, the amplitude of the workable member 8 becomes large.

FIG. 11 is a diagram for explaining the correlation between bubble growth and the behavior of the movable member when the heating element and the movable member are separated from each other.
Shows a graph of the correlation. FIG. 11 (a)
When the heating element and the movable member are separated from each other as shown in Fig. 6, the movable member is unlikely to be affected by the volume reduction of bubbles. The opening of the is initiated much later than the start of the partial growth partial contraction period. That is, the opening timing of the movable member is later than that in the case of the configuration of FIG. For the same reason, the amplitude of the movable member becomes small. In addition, in FIG.
The movement of the movable member in each period is the same as the movement described with reference to FIG.

The positional relationship between the movable member 8 and the heating element 4 is for explaining the general operation, and each operation varies depending on the position of the free end of the movable member, the rigidity of the movable member, and the like. Is. Further, as can be seen from FIGS. 9 to 11, the bubbles (A
The maximum volume of bubbles in the region) is Vf, and the bubbles grow on the liquid supply port 5 side of the bubble generation region 11 (the bubbles in the region B).
The relation of Vf> Vr is always established in the head of the present invention, where Vr is the volume at the maximum. Further, the lifetime of bubbles (foam in the area A) growing on the discharge port 7 side of the bubble generation region 11 (time from bubble generation to defoaming) is defined as Tf, and on the liquid supply port 5 side of the bubble generation region 11 If the lifetime of the growing bubbles (bubbles in the B area) is Tr, then Tf>
The relationship of Tr always holds in the head of the present invention. Then, because of the above relationship, the defoaming point of the bubble is located closer to the ejection port 7 side than the vicinity of the center of the bubble generation region 11.

Further, in this head structure, as can be seen from FIGS. 5B and 7B, the free end of the movable member 8 is displaced from the maximum displacement hl toward the liquid supply port 5 side at the initial stage of bubble generation. Also, there is a relationship (hl <h2) that the amount h2 of the maximum displacement of the free end of the movable member 8 toward the bubble generating means 4 side is larger together with the bubble elimination. For example, hl is 2 μm and h2 is 1
It is 0 μm. By establishing this relationship, it is possible to suppress the growth of bubbles to the rear of the heating element (in the direction opposite to the ejection port) and to further promote the growth of bubbles to the front of the heating element (direction toward the ejection port). . As a result, it is possible to improve the efficiency of converting the bubbling power generated in the heating element into the kinetic energy of the liquid droplets flying from the ejection port.

As described above, the head structure and the liquid discharging operation of the present embodiment have been described. According to such a form, the downstream growth component and the upstream growth component of the bubble are not equal, Most of the growth component to the upstream side disappears and the movement of the liquid to the upstream side is suppressed. Since the flow of liquid to the upstream side is suppressed, most of the bubble growth component is directed toward the discharge port without loss on the upstream side,
The discharge power is significantly improved. Further, as the bubbles contract, the movable member is displaced downward, and the liquid rapidly becomes a large flow from the common liquid supply chamber through the liquid supply port into the liquid flow path. As a result, the flow that rapidly draws the meniscus M into the liquid flow path 3 suddenly decreases, so the amount of retreat of the meniscus after ejection is reduced, and the amount of meniscus ejected from the orifice surface during refilling is also reduced accordingly. To do. Therefore, meniscus vibration is suppressed, and stable ejection can be performed at any driving frequency from low frequency to high frequency.

(Second Embodiment) In the head structure of the first embodiment, as shown in FIGS. 1 and 3, the root support portion 8C of the movable member 8 is not yet fixed to the fixed member 9. Since the position of joining (that is, bending and rising) is not the same as the end 9A of the fixing member 9, the opening region S is surrounded by the three sides of the liquid supply port 5 and the end 9A of the fixing member 9. Although it became a region, as in the form shown in FIG. 12 and FIG.
The bending support position of the root support portion 8C of the movable member 8 from the fixed member 9 may be the end portion 9A of the fixed member 9. In the case of this configuration, the opening region S is formed on the three sides of the liquid supply port 5 and the fulcrum portion 8 of the movable member 8 as shown in FIGS.
The area is surrounded by A and.

Further, in the head structure of the first embodiment, the liquid supply port 5 is an opening surrounded by four wall surfaces as shown in FIG. 3, but as shown in FIG. 14 and FIG. Of the supply portion forming member 5A (see FIG. 1), the wall surface on the liquid supply chamber 6 side opposite to the ejection port 7 side may be opened. In the case of this embodiment, as in the first embodiment, the opening region S is caused by the three sides of the liquid supply port 5 and the end 9A of the fixing member 9 as shown in FIGS. 14 and 15. It becomes an area.

It should be noted that XX 'in FIGS.
The line sectional view is the same as FIG.

(Third Embodiment) Further, in each of the above-described embodiments, as shown in FIGS. 1, 12, and 14, for example, the thickness t of the movable member 8 is the root support portion 8C of the movable member 8. It is more preferable that the difference is larger than the step amount h. For example, t = 5 μm and h = 2 μm. As a result, stress concentration concentrated on the stepped portion of the root support portion 8C of the movable member 8 that occurs when the movable member 8 is displaced can be relieved, and the durability of the root of the movable member 8 improves.

FIG. 16 is an enlarged cross-sectional view of the periphery of the base of the movable member in the head structure shown in FIG.
7 shows a modification of the movable member shown in FIG.

As typified by FIG. 16, in each of the above-described embodiments, the height position of the movable member 8 is such that the liquid supply port with respect to the fixed portion of the root support portion 8C of the movable member 8 and the fixed member 9. Although it is shifted one step to the 5 side, on the contrary,
As shown in (4), it may be shifted to the heating element (not shown) side. Also in this form, the thickness t of the movable member 8 is
The durability of the root of the movable member 8 can be improved by making it larger than the step amount h of the root support portion 8C of the movable member 8.

(Fourth Embodiment) In each of the above-described embodiments, for example, as shown in FIG. 2, the opening end face of the liquid supply port 5 on the liquid flow path 3 side and the liquid supply port 5 of the movable member 8 are shown.
By setting the relationship between the clearance α between the side surface of the movable member 8 and the side surface of the movable member 8 overlapping the opening end surface of the liquid supply port 5 on the liquid flow path 3 side in the width direction, W3> α. The ejection efficiency can be improved. For example, the overlap width W3 is set to 3 μm for the gap α of 2 μm.

Here, when the above relationship is W3> α and W
FIG. 18 and FIG. 1 show the flow of the liquid in the initial stage of foaming when 3 ≦ α.
This will be described using 9. 18 and 19 are cross-sectional views of a flow path passing through the liquid supply port. First, in the relationship of W3> α as shown in FIG. 18A, when the movable member 8 is displaced upward by the pressure at the initial stage of foaming, as shown in FIG. It occurs on the 8th side. Further, in the gap between the movable member 8 and the opening end surface of the liquid supply port 5, the arrow B
Also occurs. At this time, since the arrow B is a sufficiently large flow, the flow of the arrow B can sufficiently suppress the flow of the arrow A, and thus the flow P of the liquid to the liquid supply port 5 side can be sufficiently suppressed. Therefore, the discharge efficiency can be further improved.

On the other hand, W3 ≦ α as shown in FIG.
19B, when the movable member 8 is displaced upward by the pressure in the initial stage of foaming, the flow of the arrow A ′ is generated on the side surface of the movable member 8 as shown in FIG. A flow of arrow B ′ also occurs in the gap between the liquid supply port 5 and the opening end surface. At this time, since the flow of the arrow B'is not so large, the flow of the arrow B'cannot suppress the flow of the arrow A'as much as when W3> α, and the flow P'of the liquid to the liquid supply port 5 side. Becomes larger than when W3> α.

Therefore, as described above, when the relationship of W3> α is satisfied, the flow resistance with respect to the flow from the liquid flow path 3 to the liquid supply port 5 side becomes higher than that when the relationship is W3 ≦ α, and foaming occurs. It is possible to sufficiently suppress the flow from the liquid flow path 3 to the liquid supply port 5 side in the initial bubble growth. Further, since the inflow of the liquid flow path 3 into the liquid supply port 5 through the gap between the movable member 8 and the periphery of the liquid supply port 5 is sufficiently suppressed, the movable member 8 shields the liquid supply port 5. Definitely and promptly. Due to these things, the ejection efficiency is further improved.

(Fifth Embodiment) Further, in each of the above-mentioned embodiments, as shown in FIG. 3, for example, the discharge port of the movable member 8 which overlaps the opening end face of the liquid supply port 5 on the liquid flow path 3 side. It is more preferable that the relationship between the overlap width W4 in the seven directions and the overlap width W3 in the width direction of the movable member 8 is W3> W4. Eg W3 = 3μm, W4 = 2μ
m.

With such a relationship, when the movable member 8 displaced upward to the liquid supply port 5 side by the initial foaming starts downward displacement in the defoaming step, the free end tip of the movable member 8 and the liquid supply port 6 are separated. Since the contact width with the opening end face is small, the frictional force generated there is also reduced, and the liquid supply port is preferentially opened from the free end side of the movable member. Thereby, the liquid supply port can be surely and promptly opened by the movable member. As a result, refilling is performed more efficiently, and the ejection characteristics are further stabilized.

FIG. 20 is a sectional view taken along the direction of one liquid flow path of a liquid discharge head as a modified example of this embodiment.
Shown in. FIG. 21 is a sectional view taken along the line YY ′ of FIG. Note that FIG.
The sectional view taken along line XX ′ at 0 is the same as FIG. 2.

The liquid discharge head shown in these figures is a modification of part of the first embodiment. Instead of the first embodiment, as shown in FIG. 20, a wall surface portion 5B having a predetermined distance from the distal end surface of the movable member 8 on the discharge port 7 side is formed as a part of the supply portion forming member 5A. ing. As a result, the opening end face of the liquid supply port 5 on the liquid flow path 3 side and the movable member 8 are formed.
The clearance α between the free end 8B and the surface on the liquid supply port 5 side is apparently the wall surface part 5 when viewed from the discharge port 7 to the movable member 8.
Covered by B. Therefore, the flow from the liquid flow path 3 to the liquid supply port 5 in the direction opposite to the discharge direction at the initial stage of foaming can be sufficiently suppressed, and thus the discharge efficiency can be further improved. Also in this configuration example, as shown in FIG. 21, the overlapping width W4 of the movable member 8 in the direction of the discharge port 7 and the width of the movable member 8 overlapping the opening end surface of the liquid supply port 5 on the liquid flow path 3 side. By setting the relationship with the overlapping width W3 in the direction W3> W4, the liquid supply port can be reliably and quickly opened by the movable member 8. As a result, the liquid flow path 3 is refilled more efficiently, and the ejection characteristics are further stabilized.

(Sixth Embodiment) FIG. 22 shows a liquid discharge head according to a sixth embodiment of the present invention.

In the liquid discharge head of the form shown in FIG. 22,
The element substrate 1 and the top plate 2 are joined to each other, and a liquid flow path 3 whose one end communicates with the discharge port 7 is formed at the opening of both plates 1 and 2.

A liquid supply port 5 is provided in the liquid flow path 3, and a common liquid supply chamber 6 communicating with the liquid supply port 5 is provided.

Between the liquid supply port 5 and the liquid flow path 3, the movable member 8 has a minute gap α with respect to the opening area of the liquid supply port 5.
(For example, 10 μm or less) and are provided substantially in parallel. A region surrounded by at least the free end portion of the movable member 8 and both side portions continuous with the free end portion is larger than the opening region S of the liquid supply port 5 with respect to the liquid flow path, and the side portion of the movable member 8 and the liquid flow path. There is a minute gap β with the side wall 10. As a result, the movable member 8 can be moved in the liquid flow path 3 without frictional resistance, while the displacement toward the opening region side is restricted at the peripheral portion of the opening region S, and the liquid supply port 5 is substantially closed to close the liquid flow path 3. It is possible to prevent the liquid flow from 3 to the common liquid supply chamber 6. Further, in this embodiment, the movable member 8 is located opposite to the element substrate 1. One end of the movable member 8 is a free end that is displaced toward the heating element 4 side of the element substrate 1, and the other end side is supported by the support portion 9B.

Further, similarly to the fourth embodiment, the gap α between the opening end surface of the liquid supply port 5 on the liquid flow path 3 side and the surface of the movable member 8 on the liquid supply port 5 side, and the liquid supply port It is preferable that the relation with the widthwise overlapping width Wb of the movable member 8 that overlaps with the opening end surface of the liquid flow path 3 on the side of 5 is Wa> α in order to improve the ejection efficiency.

Further, similar to the fifth embodiment, the movable member 8 and the overlap width Wa of the movable member 8 overlapping the opening end face of the liquid supply port 5 on the liquid flow path 3 side in the discharge port 7 direction.
The relationship with the overlap width Wb in the width direction is Wb> Wa
It is more preferable that the above is effective in stabilizing the ejection characteristics.

(Seventh Embodiment) Next, a head substrate suitable for liquid ejection heads of various forms as described above and a method of manufacturing the liquid ejection head will be described.

The heating element 4 of the liquid discharge head as described above.
Circuits and elements for driving and controlling the driving are allocated to the element substrate 1 or the top plate 2 in accordance with their functions. Moreover, since the element substrate 1 and the top plate 2 are made of a silicon material, these circuits and elements can be easily and finely formed using the semiconductor wafer process technology.

The structure of the element substrate 1 formed by using the semiconductor wafer process technology will be described below.

FIG. 23 is a cross-sectional view of the element substrate 1 used in the liquid discharge heads of the various embodiments described above. FIG. 23
In the element substrate 1 shown in, the surface of the silicon substrate 201 is
A thermal oxide film 202 as a heat storage layer and an interlayer film 203 also serving as a heat storage layer are laminated in this order. Interlayer film 203
For this, a SiO ₂ film or a Si ₃ N ₄ film is used. The resistance layer 204 is partially formed on the surface of the interlayer film 203, and the wiring 205 is partially formed on the surface of the resistance layer 204. As the wiring 205, Al or Al−
Al alloy wiring such as Si or Al-Cu is used. The wiring 205, the resistance layer 204, and the interlayer film 203
A protective film 206 made of a SiO ₂ film or a Si ₃ N ₄ film is formed on the surface of the. The resistance layer 2 is formed on a portion of the surface of the protective film 206 corresponding to the resistance layer 204 and its periphery.
An anti-cavitation film 207 is formed to protect the protective film 206 from the chemical and physical shocks associated with the heat generation of No. 04. A region on the surface of the resistance layer 204 where the wiring 205 is not formed is a heat acting portion 208 which is a portion where the heat of the resistance layer 204 acts.

The film on the element substrate 1 is formed on the surface of the silicon substrate 201 by a semiconductor manufacturing technique, and the silicon substrate 201 is provided with a heat acting portion 208.

FIG. 24 is a schematic sectional view of the element substrate 1 cut along the longitudinal direction of the main elements of the element substrate 1 shown in FIG.

As shown in FIG. 24, an N type well region 422 and a p type well region 423 are partially provided in the surface layer of the silicon substrate 201 which is a P conductor. Then, by introducing and diffusing impurities such as ion plating using a general Mos process, the P-Mos 420 and the P-type well region 42 are formed in the N-type well region 422.
3 is equipped with N-Mos 421. P-Mos4
Reference numeral 20 denotes a source region 425 and a drain region 426 formed by partially introducing N-type or P-type impurities into the surface layer of the N-type well region 422, and an N-type well region 422.
The gate insulating film 42 having a thickness of several hundred angstroms is formed on the surface of the portion excluding the source region 425 and the drain region 426.
It is composed of a gate wiring 435, etc. deposited via The N-Mos 421 is a source region 425 and a drain region 426 formed by partially introducing N-type or P-type impurities into the surface layer of the P-type well region 423.
Alternatively, the P-type well region 423 includes a gate wiring 435 deposited on the surface of the portion excluding the source region 425 and the drain region 426 via a gate insulating film 428 having a thickness of several hundred angstroms. Gate wiring 4
Reference numeral 35 is made of polysilicon having a thickness of 4000 angstroms to 5000 angstroms deposited by the CVD method. These P-Mos 420 and N
-Mos 421 to C-Mos logic are configured.

N-Mos 42 in the P-type well region 423
The portion different from 1 includes N-Mo for driving the electrothermal conversion element.
An s-transistor 430 is provided. The N-Mos transistor 430 also has a source region 432 and a drain region 431 partially provided in the surface layer of the P-type well region 423 by a process such as impurity introduction and diffusion, and a source region 432 and a drain of the P-type well region 423. The gate wiring 433 and the like are deposited on the surface of the portion excluding the region 431 via the gate insulating film 428.

In this embodiment, the N-Mos transistor 430 is used as the transistor for driving the electrothermal conversion element, but it has the ability to individually drive a plurality of electrothermal conversion elements and has the above-described fine structure. The transistor is not limited to this transistor as long as the structure can be obtained.

Between the P-Mos 420 and the N-Mos 421, and between the N-Mos 421 and the N-Mos transistor 43.
An oxide film isolation region 424 is formed between elements such as 0 to 0 by field oxidation with a thickness of 5000 angstroms to 10000 angstroms, and each element is isolated by the oxide film isolation region 424. A portion of the oxide film isolation region 424 corresponding to the heat acting portion 208 serves as the first heat storage layer 434 when viewed from the front surface side of the silicon substrate 201.

On the surface of each element of P-Mos 420, N-Mos 421 and N-Mos transistor 430,
Approximately 7000 angstrom PSG film or BP
An interlayer insulating film 436 made of an SG film or the like is formed by the CVD method. After the interlayer insulating film 436 is planarized by heat treatment, the interlayer insulating film 436 and the gate insulating film 42 are formed.
Wiring is performed through an Al electrode 437 which serves as a first wiring layer through a contact hole penetrating through 8. A thickness of 10 is formed on the surfaces of the interlayer insulating film 436 and the Al electrode 437.
The interlayer insulating film 438 made of a SiO ₂ film having a thickness of 5,000 Å to 15,000 Å is plasma CV.
It is formed by the D method. The heat acting portion 208 and the N-Mos transistor 43 on the surface of the interlayer insulating film 438.
At a portion corresponding to 0, a resistance layer 204 made of a TaN _{0.8, hex} film having a thickness of about 1000 Å is formed by the DC sputtering method. The resistance layer 204 is electrically connected to the Al electrode 437 near the drain region 431 via a through hole formed in the interlayer insulating film 438. On the surface of the resistance layer 204, an Al wiring 205 serving as a second wiring layer serving as a wiring to each electrothermal conversion element.
Are formed.

The protective film 206 on the surface of the wiring 205, the resistance layer 204 and the interlayer insulating film 438 is made of plasma CVD and has a thickness of 10000 angstroms.
It is composed of a ₃ N ₄ film. The anti-cavitation film 207 deposited on the surface of the protective film 206 is at least 1 selected from Ta (tantalum), Fe (iron), Ni (nickel), Cr (chromium), Ge (germanium), Ru (ruthenium), and the like. It comprises a thin film of one or more amorphous alloys about 2500 angstroms thick.

25 to 27, an example of a manufacturing process in which the movable member 8, the flow path side wall 10 and the liquid supply port 5 are provided on the element substrate 1 as shown in FIGS. Will be described with reference to. Note that FIGS. 25 to 27 show the process by cutting planes along a direction orthogonal to the direction of the liquid flow path formed on the element substrate.

First, in FIG. 25A, an Al film having a thickness of about 2 μm is formed on the surface of the element substrate 1 on the heating element 4 side by the sputtering method. The formed Al film is patterned using a well-known photolithography process,
A plurality of Al film patterns 25 are formed at positions corresponding to the heating elements 2. Each of the Al film patterns 25 is fixed on the fixing member 9 and the side wall 10 of the flow path in the step of FIG.
Of SiN film 26, which is a material film for forming a part of the film, extends to a region to be etched.

The Al film pattern 25 functions as an etching stop layer when the liquid flow path 3 is formed by dry etching as described later. This is because the thin film of Ta or the like as the cavitation resistant film 207 in the element substrate 1 and the SiN film as the protective layer 206 on the resistor are etched by the etching gas used to form the liquid flow path 3. Therefore, etching of these layers and films is prevented by the Al film pattern 25. Therefore, in order to prevent the surface of the element substrate 1 on the heating element 4 side from being exposed when the liquid flow path 3 is formed by dry etching, the Al film patterns 25 have a direction perpendicular to the flow direction of the liquid flow path 3. The width is wider than the width of the finally formed liquid flow path 3.

Further, at the time of dry etching, C
Although ion species and radicals may be generated by the decomposition of the F ₄ , C _X F _Y , and SF ₆ gases to damage the heating element 4 and the functional element of the element substrate 1, the Al film pattern 25
By receiving these ionic species and radicals, the heating element 4 of the element substrate 1 and the functional element are protected.

Next, in FIG. 25B, a part of the flow path side wall 10 is formed on the surface of the Al film pattern 25 and the surface of the element substrate 1 on the Al film pattern 25 side by using the plasma CVD method. Thickness of the material film for forming is about 20.0 μm
The SiN film 26 is formed so as to cover the Al film pattern 25.

Next, in FIG. 25C, after the Al film is formed on the entire surface of the SiN film 26, the formed Al film is patterned by a well-known method such as photolithography to form the SiN film 26. An Al film (not shown) is formed on a portion of the surface of the substrate other than the portion where the liquid flow path 3 is formed. Then, the SiN film 26 is etched using an etching apparatus using inductively coupled plasma to form a part of the flow path side wall 10. In the etching system, CF ₄ and 0 ₂ , SF ₆
The SiN film 26 is etched using the Al film pattern 25 as an etching stop layer by using the mixed gas or the like.

Next, in FIG. 25D, an Al film 27 having a thickness of 2 is formed on the surface of the SiN film 26 by the sputtering method.
A hole formed by etching the SiN film 26 as a portion for forming the liquid flow path 3 in the previous step is formed with a thickness of 0.0 μm.
Fill with l.

Then, in FIG. 26A, FIG.
The surface of the SiN film 26 and the Al film 27 on the substrate 1 shown in FIG. 1 is CMP (Chemical Mechanical P
flattening by polishing.

Next, in FIG. 26B, an Al film 28 having a thickness of about 2.0 μm is formed on the surfaces of the SiN film 26 and the Al film 27 polished by CMP by the sputtering method, and then the formed Al film is formed. 28 is patterned using a well-known photolithography process. This Al film 28
Pattern in the step of FIG.
The SiN film, which is a material film for forming the movable member 8, extends to a region to be etched. Al film 28
The movable member 8 is formed by dry etching as described later.
It functions as an etching stop layer when forming.
That is, the SiN film 26, which is a part of the liquid flow path 3, is prevented from being etched by the etching gas used to form the movable member 8.

Next, in FIG. 26C, a SiN film having a thickness of about 3.0 μm, which is a material film for forming the movable member 8, is formed on the surface of the Al film 28 by using the plasma CVD method. . Then, the formed SiN film is dry-etched by using an etching device using inductively coupled plasma, so that the SiN film 29 at a portion corresponding to the Al film 28 which becomes a part of the liquid flow path 3 is left. The method using this etching apparatus is the same as the step shown in FIG. Since the SiN film 29 finally becomes the movable member 8, the width of the pattern of the SiN film 29 in the direction orthogonal to the flow direction of the liquid flow path 3 is that of the finally formed liquid flow path 3. It is narrower than the width.

Next, in FIG. 27A, an Al film which is a material film for forming the gap forming member 30 is formed on the surface of the Al film 28 by a sputtering method so as to cover the SiN film 29. 3.0 μm is formed. The Al film formed on the Al film 28 in the previous step is patterned using a well-known photolithography process to form the gap α between the upper surface of the movable member 8 and the liquid supply port 5 shown in FIG. The gap forming member 30 for forming the gap β between the both side portions of 8 and the flow path side wall 10 is formed on the surface and the side surface of the SiN film 29.

Next, in FIG. 27B, a negative photosensitive epoxy resin 31 made of the material shown in Table 1 below is provided on the SiN film 26, and the substrate including the gap forming member 30 made of an Al film. It is applied by spin coating to a thickness of 30.0 μm. By the above spin coating process,
The epoxy resin 31 which becomes a part of the flow path side wall 10 to which the top plate 2 is joined can be applied evenly.

[0120]

[Table 1] Then, as shown in Table 1 above, after prebaking the epoxy resin 31 using a hot plate under conditions of 90 ° C. and 5 minutes, an exposure device (manufactured by Canon: MPA60) was used.
0) is used to expose the epoxy resin 31 in a predetermined pattern with an exposure light amount of 2 [J / cm ² ]. In the negative epoxy resin, the exposed portion is cured, and the unexposed portion is not cured. Therefore, in the above-mentioned exposure step, only the portion excluding the liquid supply port 5 is exposed. Then, after forming a hole portion to be the liquid supply port 5 using the above-described developing solution, main baking is performed at 200 ° C. for 1 hour. The opening area of the hole portion that becomes the liquid supply port 5 is smaller than the area of the SiN film 29 that becomes the movable member 8.

Finally, in FIG. 27C, the Al films 25, 27, 28, and 30 are heated and etched using a mixed acid of acetic acid, phosphoric acid, and nitric acid to elute and remove the Al films 25, 27, 28, and 30. The liquid supply port 5, the movable member 8, the fixed member 9 and the flow path side wall 10 are created on the substrate 1. At that time, since an amorphous alloy having no grain boundary is used for the outermost surface layer of the element substrate 1 provided with the heating element (bubble generating means) 4,
It is possible to completely prevent the underlying wiring layer from being corroded through the pinholes and the grain boundary regions of the thin film during the above-described hot etching with the mixed acid.

As described above, a large-capacity common liquid supply chamber 6 that simultaneously communicates with each liquid supply port 5 is provided on the element substrate 1 on which the movable member 8, the flow path side wall 10 and the liquid supply port 5 are provided.
The top plate 2 provided with is joined to manufacture the liquid ejection head shown in FIGS.

(Eighth Embodiment) In the manufacturing method according to the seventh embodiment, the manufacturing process when the movable member 8, the flow path side wall 10 and the liquid supply port 5 are provided on the element substrate 1 will be described. However, the present invention is not limited to this, and a process of joining the movable member 8 and the liquid supply port 5 formed on the top plate 2 side to the element substrate 1 in which the flow path side wall 10 is formed may be used.

Hereinafter, an example of this manufacturing process will be described with reference to FIG.
~ It demonstrates with reference to FIG. 28 and 29 show the process by a cutting plane along a direction orthogonal to the direction of the liquid flow path formed on the element substrate. FIG. 30 corresponds to FIG.
FIG. 30 is a sectional view of a schematic configuration of a liquid ejection head using the top plate prepared in FIGS. 8 and 29. In the description, the same components as those in the first embodiment are designated by the same reference numerals.

First, in FIG. 28A, an oxide film (SiO ₂ ) 35 of about 1.0 μm is formed on one surface of the top plate 2 made of Si material.
m. Then, the formed SiO ₂ film 35 is
Patterning is performed using a well-known photolithography process to remove the SiO ₂ film corresponding to the location where the liquid supply port 5 shown in FIG. 30 is formed.

Next, in FIG. 28 (b), A is removed from the removed portion of the SiO ₂ film 35 on one surface of the top plate 2 and its peripheral portion.
The gap forming member 36 made of a film is coated with a thickness of about 3.0 μm. The gap forming member 36 is for forming a gap between the liquid supply port 5 and the movable member 8 which are formed in a step shown in FIG.

Next, in FIG. 28C, the SiO ₂ film 35 is formed.
And, the entire surface of the gap forming member 36 is covered with the SiN film 37 having a thickness of about 3.0 μm, which is a material film for forming the movable member 8, by using the plasma CVD method. Form.

Next, in FIG. 28D, the movable material 8 is patterned on the SiN film 37 by using a well-known photolithography process. Next, using the gap forming member as an etching stop layer, the Si top plate (thickness 6
25 μm) was subjected to through etching to form the common liquid supply chamber. After that, Al as the gap forming member 36
The film is hot etched with a mixed acid of acetic acid, phosphoric acid and nitric acid to elute and remove it. In the above patterning, the opening gap β between the movable portion 37a, which is the portion that becomes the movable member 8 in the SiN film 37, and its support portion 37b is set to 2 μm or more. Further, in the step shown in FIG. 29A described later, in order to easily form the liquid supply port 5 corresponding to the movable member 8, the movable portion 37a of the SiN film 37 has a plurality of slits 37c penetrating the front and back surfaces thereof. Is preferably 1 μm or less. The projection area of the movable portion 37a is larger than the opening area (removal area of the SiO ₂ film 35) of the portion serving as the liquid supply port.

Next, in FIG. 29A, a portion of the Si top plate 2 where the SiO ₂ film 35 is removed is moved to a movable portion 37.
Anisotropic wet etching is performed through the slit 37c of a to form the liquid supply port 5.

Finally, in FIG. 29 (b), a film having a thickness of about 0.
A 5 μm SiN film 38 is formed, and the SiN film 38 fills the slit 37c opened in the movable member 8. At this time, since the gap of the slit 37c is set to 1 μm or less, the slit 37c is closed. However, since the gap β between the movable portion 37a and the support portion 37b is set to 2 μm or more, the gap β is not closed by the SiN film 38. Absent. Also,
The SiN film formed by the LPCVD method is also coated on the side wall of silicon formed by the anisotropic etching or the through etching of the silicon top plate to prevent corrosion by ink.

As described above, the movable member 8 and the liquid supply port 5 are provided on the top plate 2 side, and further, the large-volume common liquid supply chamber 6 that communicates with each liquid supply port 5 at the same time is provided. The element ejection substrate 1 having a channel wall forming the fluid channel 3 having one end communicating with the ejection port 7 is joined to manufacture the liquid ejection head shown in FIG. The liquid ejection head of this form also has the same effect as the liquid ejection head having the structure shown in FIGS.

(Other Embodiments) Various embodiments suitable for a head using the liquid ejection principle of the present invention will be described below.

<Side Shooter Type> FIG. 31 is a sectional view of a so-called side shooter type liquid ejection head. In this description, the same components as those of the first embodiment are designated by the same reference numerals. In the liquid ejection head of this aspect, as shown in FIG. 31, the heating element 4 and the ejection port 7 face each other on a parallel plane, and the liquid flow path 3 extends in the axial direction along the ejection direction of the liquid from the ejection port 7. This is different from the first embodiment in that they communicate with each other at a right angle. Also in such a liquid ejection head, the effect based on the ejection principle similar to that of the first embodiment and the like can be obtained, and the manufacturing methods described in the seventh and eighth embodiments can be easily applied.

<Movable Member> In the above-mentioned various embodiments, the material forming the movable member has solvent resistance to the discharged liquid and has elasticity for operating well as the movable member. If

The material of the movable member has high durability,
Has a metal such as silver, nickel, gold, iron, titanium, aluminum, platinum, tantalum, stainless steel, phosphor bronze, and its alloys, or a resin having a nitrile group such as acrylonitrile, butadiene, styrene, and an amide group such as polyamide. Resins, resins having carboxyl groups such as volvocarbonate, resins having aldehyde groups such as polyacetal, resins having sulfone groups such as polysulfone,
In addition, resins such as liquid crystal polymers and their compounds, metals with high ink resistance such as gold, tungsten, tantalum, nickel, stainless steel, titanium, alloys of these and ink-resistant ones, or polyamides. A resin having an amide group such as
Resins having aldehyde groups such as polyacetal, resins having ketone groups such as polyetheretherketone, resins having imide groups such as polyimide, resins having hydroxyl groups such as phenol resin resins, resins having ethyl groups such as polyethylene, polypropylene Resins with alkyl groups such as
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 movable member in the present invention has a thickness of the order of μm.

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 the 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 an image on a recording medium, that is, a so-called bubble jet recording method, FIG.
As indicated by the broken line 2 in FIG. 2, it can be seen that there is a non-foaming effective area 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. On the other hand, in the liquid discharge head of the present invention, the maximum discharge amount is regulated because the liquid flow path including the bubble generating means is substantially shielded except the discharge port, and therefore the solid line in FIG. As shown, there is a region where the discharge amount does not change even if there is a large variation in the area of the heating element or the bubbling power, and by using this region, the discharge amount of large dots can be stabilized.

<Element Substrate> The structure of the element substrate 1 provided with the heating element 10 for applying heat to the liquid will be described below.

FIG. 33 shows a side cross-sectional view of the main part of the liquid ejecting apparatus of the present invention. FIG. 33 (a) shows a head having a protective film described later, and FIG. 33 (b) does not have a protective film. Is.

A top plate 2 is arranged on the element substrate 1, and a liquid flow path 3 is formed between the element substrate 1 and the top plate 2.

In the element substrate 1, a silicon oxide film or a silicon nitride film 106 for the purpose of insulation and heat storage is formed on a base body 107 such as silicon, and a hafnium boride (HfB2) forming the heating element 10 is formed thereon. ), Tantalum nitride (TaN), tantalum aluminum (TaAl), and the like, and an electric resistance layer 105 (0.01 to 0.2 μm thick) and a wiring electrode 104 (0.2 to 1.0 μm thick) such as aluminum. Patterning is performed as shown in FIG. A voltage is applied from the wiring electrode 104 to the resistance layer 105,
An electric current is applied to 5 to generate heat. On the resistance layer 105 between the wiring electrodes 104, a protective film 103 made of silicon oxide, silicon nitride, or the like is formed to a thickness of 0.1 to 2.0 μm. 0.6
(μm thickness) is formed to protect the resistance layer 105 from various liquids such as ink.

In particular, the pressure and shock wave 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, the tantalum (Ta) metal material is used.
Etc. are used as the anti-cavitation layer 102.

Further, depending on the combination of the liquid, the flow channel structure, and the resistance material, the above-mentioned resistance layer 105 may not have the protective film 103, and an example thereof is shown in FIG. 33 (b). Examples of the material of the resistance layer 105 that does not require the protective film 103 include iridium-tantalum-aluminum alloy.

As described above, as the constitution of the heating element 4 in each of the above-described embodiments, the resistance layer 1 between the electrodes 104 described above is used.
05 (heat generating portion) only, or may include the protective film 103 for protecting the resistance layer 105.

In each of the embodiments, the heating element 4 having the heating portion constituted by the resistance layer 105 that generates heat in response to an electric signal is used, but the heating element 4 is not limited to this.
Any material may be used as long as it produces sufficient bubbles in the foaming liquid to eject the ejection liquid. For example, it may be a photothermal converter that generates heat when receiving light from a laser or the like, or a heating element that has a heating portion that generates heat when receiving high frequency.

On the element substrate 1 described above, in addition to the heating element 10 including the resistance layer 105 forming the heating portion and the wiring electrode 104 for supplying an electric signal to the resistance layer 105, A transistor, a diode, a latch for selectively driving the heating element 4 (electrothermal conversion element),
Functional elements such as a shift register may be integrally formed by a semiconductor manufacturing process. Further, in order to drive the heat generating portion of the heat generating element 4 provided on the element substrate 1 as described above and eject the liquid, as shown in FIG. 34 through the wiring electrode 104 on the resistance layer 105 described above. By applying such a rectangular pulse, the resistance layer 105 between the wiring electrodes 104 is rapidly heated. In the head of each of the above-described embodiments, the voltage is 24 V, the pulse width is 7 μsec, and the current is 150 m.
A. The heating element was driven by applying an electric signal at 6 kHz, and the liquid ink was ejected from the ejection port 7 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.

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, or operation of the movable member.

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 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.

[0151]

[Table 2] <Liquid Ejecting Device> FIG. 35 shows a schematic configuration of an inkjet recording device which is an example of a liquid ejecting device to which the liquid ejecting head having the structure described in the above-described various embodiments can be mounted and applied. A head cartridge 601 mounted on the inkjet recording apparatus 600 shown in FIG. 35 has the liquid ejection head having the above-described structure and a liquid container that holds the liquid supplied to the liquid ejection head. The head cartridge 601 is shown in FIG.
As shown in FIG. 7, the motor 602 is mounted on the carriage 607 that engages with the spiral groove 606 of the lead screw 605 that rotates via the driving force transmission gears 603 and 604 in association with the forward / reverse rotation of the drive motor 602. Drive motor 60
The power of No. 2 causes the head cartridge 601 to move along with the carriage 607 along the guides 608 along the arrows a and b.
Is reciprocated in the direction of. Inkjet recording device 60
0 is provided with a recording medium conveying unit (not shown) for conveying a print paper P as a recording medium that receives a liquid such as ink ejected from the head cartridge 601. The platen 60 is conveyed by the recording medium conveying means.
A paper pressing plate 610 for the print paper P conveyed on the sheet 9.
Presses the print paper P against the platen 609 in the moving direction of the carriage 607.

Photocouplers 611 and 612 are arranged near one end of the lead screw 605. The photocouplers 611 and 612 include the carriage 6
07 lever 607a, photocouplers 611 and 6
Home position detection means for confirming the presence in the 12 areas and switching the rotation direction of the drive motor 602. In the vicinity of one end of the platen 609, a support member 613 that supports a cap member 614 that covers the front surface of the head cartridge 601 on which the ejection port is provided is provided. Further, an ink suction means 615 for sucking ink that has been discharged from the head cartridge 601 and accumulated inside the cap member 614 is provided. The ink suction unit 615 suction-recovers the head cartridge 601 through the opening of the cap member 614.

The ink jet recording apparatus 600 is provided with a main body support 619. A moving member 618 is attached to the main body support 619 in the front-back direction, that is, the carriage 6
It is movably supported in a direction perpendicular to the moving direction of 07. A cleaning blade 617 is attached to the moving member 618. Cleaning blade 6
Not limited to this form, 17 may be a known cleaning blade of another form. Further, the ink suction means 6
A lever 620 for starting suction in the suction recovery operation by 15 is provided. The lever 620 moves in accordance with the movement of the cam 621 that engages with the carriage 607, and the driving force from the driving motor 602 switches the clutch. The movement is controlled by a known transmission means such as. An ink jet recording control unit that gives a signal to a heating element provided in the head cartridge 601 and controls drive of each mechanism described above is provided on the recording apparatus main body side,
It is not shown in FIG.

In the ink jet recording apparatus 600 having the above-described structure, the head cartridge 601 reciprocates over the entire width of the print sheet P with respect to the print sheet P conveyed on the platen 609 by the recording medium conveying means. When a drive signal is supplied from the drive signal supply means (not shown) to the head cartridge 601 during this movement, ink (recording liquid) is ejected from the liquid ejection head section onto the recording medium in response to this signal, and recording is performed. Done.

FIG. 36 is a block diagram of the entire recording apparatus for carrying out ink jet recording by the liquid ejection apparatus 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 in the recorder.
It is input to a CPU (Central Processing Unit) 302 which also serves as a head drive signal supply means. The CPU 302 stores the data input to the CPU 302 in a RAM (random access memory) 304 based on a control program stored in a ROM (read only memory) 303.
It is processed using peripheral units such as and converted to data (image data) to be printed.

Further, the CPU 302 drives the motor 602 for moving the carriage 607 carrying the recording paper and the head cartridge 601 in synchronization with the image data in order to record the image data at an appropriate position on the recording paper.
Make drive data to drive. The image data and the motor drive data are sent to the head cartridge 601 via the head driver 307 and the motor driver 305, respectively.
And is transmitted to the driving motor 602 and driven at controlled timings to form an image.

The recording medium 150 used in such a recording apparatus and to which liquid such as ink is applied is various kinds of paper, OHP sheets, plastic materials used for compact discs, decorative plates, etc., cloth, aluminum. 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 recording device, various kinds of paper and O
A printer device for recording on HP sheets, a plastic recording device for recording on a plastic material such as a compact disk, a metal recording device for recording on a metal plate,
A leather recording device for recording on leather, a wood recording device for recording on wood, a ceramic recording device for recording on a ceramic material, a recording device for recording on a three-dimensional network structure such as a sponge, or a cloth. It also includes a printing device and the like for recording on.

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

[0161]

As described above, according to the present invention, the communication state between the liquid flow path and the liquid supply port is immediately established within the period in which the bubble is substantially isotropically grown at the initial stage when the bubble is generated by the bubble generating means. By blocking the liquid by the movable member and removing the discharge port inside the liquid flow path to make it substantially sealed, pressure waves due to bubble growth in the bubble generation area are supplied to the liquid supply port side and the common liquid supply. It became possible to drastically improve the ejection power by propagating most of it toward the ejection port side without propagating to the chamber side. In addition, even when using a high-viscosity recording liquid to fix it on recording paper at high speed or to eliminate bleeding at the boundary between black and color, it is possible to improve the high-viscosity ink by dramatically improving the ejection power. Can be discharged. In addition, when the environment changes at the time of recording, especially in a low temperature and low humidity environment, the ink thickening area may increase at the ejection port and the ink may not be ejected normally at the start of use, but in the present invention, good ejection can be performed from the first shot. . Further, since the ejection power is dramatically improved, it is possible to reduce the size of the heating element used as the bubble generating means and reduce the energy input for ejection.

Further, since the pressure wave due to the bubble growth in the bubble foaming region is not propagated to the liquid supply port and the common liquid supply chamber side, the liquid hardly moves to the common liquid supply chamber side. The amount of retreat of the meniscus at the discharge port can be minimized. As a result, the time for the meniscus to return to the initial state after ejection is very short, that is, the fixed amount of ink replenishment (refill) to the liquid flow path is completed quickly, so highly accurate (constant) ink ejection is possible. The ejection frequency (driving frequency) can also be dramatically improved in the implementation.

Furthermore, since the bubble growth in the bubble generation region greatly grows toward the ejection port side and suppresses the growth toward the liquid supply port side, the defoaming point is from the vicinity of the center of the bubble generation region to the ejection port. Since the defoaming force can be reduced while being located in the side portion and maintaining the foaming power, it is possible to greatly improve the mechanical and physical destruction life of the heating element due to the defoaming force in the bubble generation region.

Further, the root support portion which is integrally formed with the movable member for supporting the root of the movable member has a step so that the height position of the movable member is displaced by one step from the fixed position of the root support portion. By having it, it is possible to relieve the stress concentration on the fixed position of the root support portion of the movable member when the movable member is displaced. Moreover, since the thickness of the movable member is larger than the step amount of the root support portion of the movable member, stress concentration that is generated when the movable member is displaced is concentrated on the step portion of the root support portion of the movable member. It alleviates and the durability of the base of the movable member is improved.

Further, the gap α between the liquid flow port side opening end surface of the liquid supply port and the liquid supply port side surface of the movable member and the movable member overlapping the liquid flow port side liquid flow path side opening end face of the movable member. By setting the relationship with the overlap width W3 in the width direction to be W3> α, it is possible to sufficiently suppress the flow from the liquid flow path to the liquid supply port side in the bubble growth in the initial stage of foaming, so that the liquid generated by the movable member is used. The supply port can be shielded reliably and promptly. As a result, the ejection characteristics are further improved.

Furthermore, the relationship between the overlap width W4 of the movable member, which overlaps the opening end surface of the liquid supply port on the liquid flow path side in the discharge port direction, and the overlap width W3 of the movable member in the width direction, is set to W3> W4. As a result, the liquid supply port can be surely and quickly opened by the movable member, and the ejection characteristics are further stabilized.

Further, by adopting an amorphous alloy thin film as the anti-cavitation film of the outermost surface layer of the bubble generating means, the mechanical and physical destruction life of the heating element can be further greatly improved.

Further, in the manufacturing process of the liquid discharge head of the present invention, by adopting the amorphous alloy, A
Even in the removal process of removing the l film to form the liquid flow path and the liquid supply port, the damage to the underlying wiring layer can be greatly reduced and the yield can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view taken along one liquid flow path direction of a liquid ejection head according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line X-X ′ of FIG.

3 is a cross-sectional view taken along the line Y-Y 'of FIG.

FIG. 4 is a sectional view of a flow path for explaining a “linear communication state”.

FIG. 5 is a sectional view of the liquid ejection head along the liquid flow path direction for explaining the ejection operation of the liquid ejection head having the structure shown in FIGS. It is shown.

FIG. 6 is a cross-sectional view of the liquid ejection head taken along the liquid flow path direction for explaining the ejection operation subsequent to FIG.

FIG. 7 is a sectional view of the liquid ejection head taken along the direction of the liquid flow path, for explaining the ejection operation subsequent to FIG. 6;

FIG. 8 is a diagram showing an isotropic growth eel of the bubbles of FIG. 5 (b).

9 is a graph showing the correlation between the time change of bubble growth and the behavior of the movable member in the regions A and B in FIGS. 5 to 7. FIG.

FIG. 10 is a graph showing the correlation between the time change of bubble growth and the behavior of the movable member in the liquid ejection head having a configuration in which the relative positions of the movable member and the heating element shown in FIG. 1 are different.

FIG. 11 is a graph showing the correlation between the time change of bubble growth and the behavior of the movable member in the liquid ejection head having a configuration in which the relative positions of the movable member and the heating element shown in FIG. 1 are different.

FIG. 12 is a cross-sectional view taken along one liquid flow path direction of a liquid ejection head according to a first modification of the second embodiment of the present invention.

13 is a cross-sectional view taken along the line Y-Y ′ of FIG.

FIG. 14 is a cross-sectional view taken along one liquid flow path direction of a liquid ejection head according to a second modification of the second embodiment of the present invention.

15 is a cross-sectional view taken along the line Y-Y ′ of FIG.

16 is an enlarged cross-sectional view showing a peripheral portion of the base of the movable member in the head structure shown in FIG.

17 is a cross-sectional view showing a modified example of the movable member shown in FIG.

FIG. 18 is a cross-sectional view through the liquid supply port for explaining the flow of the liquid in the initial stage of foaming in the structure of the relationship of W3> α.

FIG. 19 is a cross-sectional view through the liquid supply port for explaining the flow of the liquid in the initial stage of foaming in the case of the structure of W3 ≦ α.

FIG. 20 is a sectional view taken along one liquid flow path direction of a liquid ejection head as a modified example of the fifth embodiment of the present invention.

21 is a cross-sectional view taken along the line YY ′ of FIG. 20, which is shifted from the center of the discharge port to the top plate 2 side at the point Y1.

FIG. 22 is a diagram showing a liquid ejection head according to a sixth embodiment of the present invention.

FIG. 23 is a cross-sectional view of an element substrate used in liquid ejection heads of various embodiments.

FIG. 24 is a schematic cross-sectional view of the element substrate cut along the main element of the element substrate shown in FIG.

FIG. 25 is a drawing for explaining the manufacturing method of the liquid ejection head, which is the fifth embodiment of the present invention.

FIG. 26 is a view for explaining the manufacturing method of the liquid ejection head, which is the fifth embodiment of the present invention, and shows the continuation of the step in FIG. 25.

FIG. 27 is a diagram for explaining the manufacturing method of the liquid ejection head, which is the fifth embodiment of the present invention, and shows the continuation of the step in FIG. 26.

FIG. 28 is a drawing for explaining the manufacturing method of the liquid ejection head, which is the sixth embodiment of the present invention.

FIG. 29 is a diagram for explaining the manufacturing method for the liquid ejection head, which is the sixth embodiment of the present invention, and shows the continuation of the step in FIG. 28.

FIG. 30 is a cross-sectional view showing a schematic configuration of a liquid ejection head according to a sixth embodiment of the present invention.

FIG. 31 is a view for explaining an example of a side shooter type head to which the liquid ejection method of the present invention is applied.

FIG. 32 is a graph showing a relative relationship between a heating element area and an ink ejection amount.

FIG. 33 is a vertical cross-sectional view of a liquid ejection head of the present invention, in which (a) has a protective film and (b) has no protective film.

FIG. 34 is a diagram of waveforms for driving a heating element used in the present invention.

FIG. 35 is a diagram showing a schematic configuration of a liquid ejection apparatus equipped with the liquid ejection head of the present invention.

FIG. 36 is a block diagram of the entire apparatus for performing liquid discharge recording in the liquid discharge method and liquid discharge head of the present invention.

FIG. 37 is a cross-sectional view showing a state of a movable member in a conventional liquid ejection head.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Element substrate 2 Top plate 3 Liquid flow path 4 Heating element (bubble generating means) 5 Liquid supply port 6 Common liquid supply chamber 7 Discharge port 8 Movable member 9 Support member 10 Flow path side wall 11 Bubble generation area 21 Bubble 22 Discharge droplet 25 Al film pattern 26, 29, 37, 38 SiN film 27, 28 Al film 30, 36 Gap forming member 31 Photosensitive epoxy resin 35 SiO ₂ film 37a Movable part 37b Support part 37c Slit 39 Channel wall 102 Cavitation resistant layer 103 Protection Film 104 Wiring electrode 105 Resistive layer 106 Silicon nitride film 107 Base 201 Silicon base 202 Thermal oxide film 203 Interlayer film 204 Resistive layer 205 Wiring 206 Protective layer 207 Cavitation resistant film 208 Thermal action part 300 Host computer 301 Input / output interface 302 CPU 303 ROM 304 RAM 305 Motorized Driver 307 Head driver 600 Ink jet recording apparatus 601 Head cartridge 602 Drive motors 603 and 604 Drive transmission gear 605 Lead screw 606 Spiral groove 607 Carriage 607a Lever 608 Guide 609 Platen 610 Paper pressing plates 611 and 612 Photo coupler 613 Support member 614 Cap member 615 Ink suction means 617 Cleaning blade 618 Moving member 619 Main body support 620 Lever 621 Cam α, β Gap

─────────────────────────────────────────────────── (72) Inventor Masanori Takenouchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masami Ikeda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Hiroshi Sugitani, 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor, Kei Saito 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. ( 56) References JP-A-11-235829 (JP, A) JP-A-2-113950 (JP, A) JP-A-11-58743 (JP, A) JP-A-1-145158 (JP, A) Flat 10-202915 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B41J 2/05 B41J 2/01 B41J 2/16

Claims (18)

(57) [Claims] 1. A plurality of discharge ports for discharging a liquid, a plurality of liquid flow paths having a bubble generation region, one end of which is always in communication with each discharge port, for generating bubbles in the liquid, and the bubbles. Bubble generating means for generating energy for generating and growing, a plurality of liquid supply ports respectively disposed in the plurality of liquid flow paths and communicating with a common liquid supply chamber, and the liquid flow path side of the liquid supply ports A movable member having a free end, which is supported with a minute gap therebetween, and a region surrounded by at least the free end portion and both side portions continuous to the free end portion of the movable member is a liquid flow of the liquid supply port. A liquid ejecting method of a liquid ejecting head, which is larger than an opening area for a path, wherein a whole of the bubble grows isotropically by the bubble generating unit after a drive voltage is applied to the bubble generating unit. Period is Until Ryosuru, have a period in which the movable member is substantially shut off by sealing said opening area, said bubble generation
The lifetime of bubbles growing on the discharge port side of the region is T
f and grow on the liquid supply port side of the bubble generation region.
If the lifetime of a bubble is Tr, then the relation of Tf> Tr
A liquid discharge method characterized in that the relationship always holds . 2. The period during which the movable member hermetically closes the opening region and substantially shuts off is continued until at least the period during which the entire bubble is isotropically grown by the bubble generating means ends. The liquid ejection method according to claim 1, wherein 3. After the period in which the movable member seals the opening area and substantially blocks the opening area, while the portion of the bubbles generated by the bubble generating means on the discharge port side is growing, Liquid supply from the common liquid supply chamber to the liquid flow path starts displacement from the position where the movable member seals the opening area and substantially cuts off to the bubble generating means side in the liquid flow path. The liquid discharge method according to claim 1 or 2, wherein 4. A plurality of ejection ports for ejecting liquid,
A plurality of liquid flow paths each having one end constantly communicating with each of the discharge ports and having a bubble generation region for generating bubbles in the liquid; a bubble generation unit for generating energy for generating and growing the bubbles; A plurality of liquid supply ports that are respectively disposed in the liquid flow paths of the liquid communication port and communicate with a common liquid supply chamber, and have free ends that are supported with a minute gap with respect to the liquid flow path side of the liquid supply ports. A liquid ejecting method of a liquid ejecting head, comprising a movable member, and a region surrounded by at least a free end of the movable member and both side portions continuous with the movable member is larger than an opening region of the liquid supply port with respect to a liquid flow path. The movable member hermetically closes and substantially blocks the opening area, and then the movable member is moved while the portion of the bubbles generated by the bubble generating unit on the discharge port side is growing. The member is Displacement is started from the position where the opening region is closed and substantially blocked to the bubble generating means side in the liquid flow path, and liquid supply from the common liquid supply chamber to the liquid flow path is enabled. A method for ejecting a liquid. 5. The displacement of the movable member side of the bubbles after the displacement of the movable member from the position where the movable region is sealed and substantially cut off to the bubble generation means side in the liquid flow path is started. The movable member is further displaced toward the bubble generating means side while the part is contracted, and supplies the liquid from the common liquid supply chamber to the liquid flow path. Liquid ejection method. 6. The change in bubble growth volume in the bubble generation region and the time from bubble generation to bubble disappearance are significantly different between the ejection port side and the liquid supply port side. 6. The liquid discharge method according to any one of items 5 to 5. 7. The liquid ejection method according to claim 1, wherein the bubble generation region is not exposed to the atmosphere. 8. The maximum volume of bubbles growing on the discharge port side of the bubble generation region is Vf, and the maximum volume of bubbles growing on the liquid supply port side of the bubble generation region is Vf.
8. The liquid ejection method according to claim 1, wherein the relationship of Vf> Vr is always satisfied when r is satisfied. 9. A root support portion integrally formed with the movable member that supports the root of the movable member, so that the height position of the movable member is displaced from the fixed position of the root support portion by one step. A step is provided, and the thickness of the movable member is larger than the amount of the step.
8. The liquid ejection method according to any one of 8 above. 10. A gap α between an opening end of the liquid supply port on the liquid flow path side and a side face of the liquid supply port of the movable member, and an opening end of the liquid supply port on the liquid flow path side. Overlap width W3 of the movable member that overlaps with each other in the width direction
The relationship between and is W3> α.
9. The liquid ejection method according to any one of 9 above. 11. A relationship between an overlap width W4 of the movable member that overlaps the opening end of the liquid supply port on the liquid flow path side in the discharge port direction and an overlap width W3 of the movable member in the width direction. Is W3> W4, The liquid discharge method of any one of Claims 1-10 characterized by the above-mentioned. 12. A plurality of discharge ports for discharging a liquid, a plurality of liquid flow paths each having one end constantly communicating with each discharge port and having a bubble generation region for generating bubbles in the liquid, and the bubbles. Bubble generating means for generating energy for generating and growing, a plurality of liquid supply ports respectively disposed in the plurality of liquid flow paths and communicating with a common liquid supply chamber, and the liquid flow path side of the liquid supply ports A movable member having a free end, which is supported with a minute gap therebetween, and a region surrounded by at least the free end portion and both side portions continuous to the free end portion of the movable member is a liquid flow of the liquid supply port. It is larger than the opening region for the path, and after the drive voltage is applied to the bubble generating means until the end of the period in which the entire bubble is isotropically grown by the bubble generating means, The movable member After the period in which the movable member seals the opening region and substantially blocks the opening region, the discharge of the bubbles generated by the bubble generating means is performed after the period in which the movable member seals the opening region and substantially blocks the opening region. While the portion on the outlet side is growing, the movable member starts to be displaced to the bubble generating means side in the liquid flow path from a position where the opening region is sealed and substantially cut off, and the common A liquid ejection head capable of supplying a liquid from a liquid supply chamber to the liquid flow path, wherein the maximum volume of bubbles growing on the ejection port side of the bubble generation region is Vf, and When Vr maximum when the volume of the bubble growing in said liquid supply port side, Vf> relationship Vr is always standing Chi, and the bubble
Life time of bubbles growing on the outlet side of the generation area
Is defined as Tf, and is defined on the liquid supply port side of the bubble generation inclined region.
If the lifetime of a long bubble is Tr, then Tf> Tr
The liquid discharge head is characterized in that the relationship is always established . 13. The liquid ejection head according to claim 12 , wherein the defoaming point of the bubble is located closer to the ejection port than the vicinity of the center of the bubble generation region. 14. A root support part integrally formed with the movable member supporting the base of the movable member shifts the height position of the movable member one step from the fixed position of the root support part, has a step, according to claim 1, characterized in that the larger the thickness of the movable member than the surface level difference
The liquid discharge head according to 2 or 13 . 15. A gap α between an opening end of the liquid supply port on the liquid flow path side and a side face of the liquid supply port of the movable member, and an opening end of the liquid supply port on the liquid flow path side. Overlap width W3 of the movable member that overlaps with each other in the width direction
Claim relationship with is characterized in that the W3> alpha 12
15. The liquid ejection head according to any one of items 1 to 14 . 16. A relationship between an overlap width W4 of the movable member in the discharge port direction and an overlap width W3 of the movable member in the width direction overlapping the opening end of the liquid supply port on the liquid flow path side. Is W3> W4, The liquid discharge head according to any one of claims 12 to 15 , wherein 17. A liquid discharge head according to any one of claims 12 to 16 , and a recording medium transfer unit that transfers a recording medium that receives the liquid discharged from the liquid discharge head. Liquid ejector. 18. The liquid ejection apparatus according to claim 17 , wherein recording is performed by ejecting ink from the liquid ejection head and adhering the ink to the recording medium.