JPH11263014A - Liquid jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the mechanical strength of the lid substrate of a liquid jet recording head formed from a resin and to obtain the lid substrate of higher accuracy. SOLUTION: In a liquid jet recording head consisting of a lid substrate 1 having a liquid chamber 6 housing a recording liquid, a plurality of the flow channels 5 communicating with the liquid chamber 5 and the recording liquid inflow port 3 of the liquid chamber 6 and a heating element substrate 2 having the heat energy generating means engaged with the lid substrate 1 to constitute the liquid chamber 6 and the flow channels 5 and provided corresponding to the flow channels 5 to generate air bubbles in a recording liquid by heat to emit the liquid as small liquid droplets, the lid substrate 1 is integrally molded from plastic along with the recording liquid inflow part 3 and the flow channels 5 and, at the same time, ribs 7 having a projected shape are provided to the surface of the outer wall of the lid substrate 1 longitudinally and these ribs 7 may be provided to the liquid chamber 6 and may be provided on respective diagonal lines.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid jet recording head, and more particularly to a bubble jet type liquid jet recording head.

[0002]

2. Description of the Related Art Non-impact recording methods have recently attracted attention in that noise during recording is extremely small to a negligible level. Among them, the so-called ink jet recording method, which can perform high-speed recording and can perform recording on so-called plain paper without the need for a special fixing process, is an extremely powerful recording method. Some have been proposed and commercialized with improvements, while others are still being put to practical use. Such an ink jet recording method performs recording by flying droplets of a recording liquid called so-called ink and attaching the droplets to a recording member, and a method of generating the droplets of the recording liquid and generating the droplets. The control method for controlling the flying direction of the recording liquid droplet is roughly classified into several types.

[0003] First, for example, US Pat.
No. 60429 (Tele type system), in which droplets of a recording liquid are electrostatically absorbed, and the generated recording liquid droplets are subjected to an electric field control in accordance with a recording signal to control a recording member. The recording is performed by selectively adhering the recording liquid droplets onto the recording medium. More specifically, an electric field is applied between the nozzle and the accelerating electrode to discharge uniformly charged droplets of the recording liquid from the nozzle, and the discharged droplets of the recording liquid are electrically controlled according to the recording signal. X configured as possible
The recording is performed by causing the droplets to fly between the y-deflection electrodes and selectively adhering small droplets onto the recording member by a change in the intensity of the electric field.

The second system is disclosed in, for example, US Pat.
No. 275, U.S. Pat. No. 3,298,030 (Sweet system), which generates small droplets of a recording liquid whose charge amount is controlled by a continuous vibration generation method. The recording is performed on the recording member by causing the droplet having the controlled charge amount to fly between the deflection electrodes to which a uniform electric field is applied. In particular,
A charging electrode to which a recording signal is applied is disposed at a predetermined distance in front of an orifice (ejection port) of a nozzle which is a part of a recording head provided with a piezoelectric vibrating element, and a fixed frequency is applied to the piezoelectric vibrating element. By applying the electric signal of (1), the piezoelectric vibrating element is mechanically vibrated, and a droplet of the recording liquid is ejected from the ejection port. At this time, a charge is electrostatically induced in the recording liquid droplet discharged by the charging electrode, and the droplet is charged with a charge amount according to the recording signal. The droplet of the recording liquid whose charge amount is controlled is deflected according to the charge amount added when flying between the deflecting electrodes to which a constant electric field is uniformly applied, and only the droplet carrying the recording signal Can adhere to the recording member.

A third method is disclosed in, for example, US Pat.
No. 153, which is a method (Hertz method) in which an electric field is applied between a nozzle and a ring-shaped charging electrode to generate and atomize small droplets of a recording liquid by a continuous vibration generation method and perform recording. is there. That is, in this method, the intensity of the electric field applied between the nozzle and the charging electrode is modulated in accordance with the recording signal, so that the atomization state of the small droplet is controlled and the gradation of the recorded image is printed.

A fourth method is disclosed in, for example, US Pat.
Method disclosed in the specification of No. 120 (Stemme method)
In this system, the principle is fundamentally different from the above three systems. That is, in each of the three methods, the droplets of the recording liquid ejected from the nozzles are electrically controlled while flying, and the droplets carrying the recording signal are selectively deposited on the recording member. Recording. On the other hand, in the Stemme system, recording is performed by ejecting and flying a small droplet of a recording liquid from an ejection port in accordance with a recording signal. In other words, the Stemme method applies an electric recording signal to a piezo-vibration element attached to a recording head having a discharge port for discharging a recording liquid, and converts the electric recording signal into mechanical vibration of the piezo-vibration element. In accordance with the mechanical vibration, the recording is performed by ejecting a small droplet of the recording liquid from the ejection port and attaching the droplet to the recording member.

[0007] These four conventional methods have their own characteristics, but the other has problems to be solved. In other words, in the first to third systems, the direct energy of the generation of the droplet of the recording liquid is electrical energy, and the deflection control of the droplet is also electric field control. Therefore, the first method is simple in configuration, but requires a high voltage to generate small droplets, and is not suitable for high-speed printing because it is difficult to use a multi-nozzle recording head.

The second method enables multi-nozzles of the recording head and is suitable for high-speed recording.
There are problems that the electrical control of the recording liquid droplets is sophisticated and difficult, and that satellite dots are likely to be formed on the recording member.

The third method has a feature that an image having excellent gradation can be recorded by atomizing a recording liquid droplet. On the other hand, it is difficult to control the atomization state. There are various problems, such as fogging and difficulty in making the recording head multi-nozzle, which is not suitable for high-speed recording.

The fourth method has relatively many advantages over the first to third methods. That is, in order to perform recording by discharging the recording liquid from the discharge port of the nozzle on demand (on-demand), the first to third printing methods are required.
It is not necessary to collect droplets that are not required for image recording among the droplets ejected and flying as in the method of (1), and the conductive recording liquid is removed as in the first and second methods. There is no need to use the recording liquid, and there are great advantages such as a high degree of freedom in the material of the recording liquid. However, on the other hand, it is difficult to make the recording head a multi-nozzle, because there is a problem in processing the recording head and it is extremely difficult to reduce the size of the piezoelectric vibrating element having a desired resonance number. The recording liquid droplets are ejected and fly by the mechanical energy of the piezo vibrating element, which is the mechanical vibration.
It has disadvantages such as being unsuitable for high-speed recording.

Further, Japanese Patent Application Laid-Open No. 48-9622 (corresponding to the specification of the aforementioned US Pat. No. 3,747,120) discloses that, as a modification, instead of using the mechanical vibration energy by means such as the aforementioned piezoelectric vibrating element, The use of heat energy is described. That is, the above-mentioned publication describes a so-called bubble jet liquid jet recording apparatus that uses a heating coil that directly heats a liquid as a pressure increasing means instead of a piezo vibrating element in order to generate vapor that causes a pressure increase. Have been.

However, in the above publication, a heating coil as a pressure increasing means is energized to directly heat the liquid ink in a bag-shaped ink chamber (liquid chamber) having only one opening through which the liquid ink can enter and exit. There is no description of how to heat the liquid when continuous and repeated liquid ejection is performed. In addition, the position where the heating coil is provided is the deepest part of the bag-shaped liquid chamber far from the supply path of the liquid ink. It is not suitable. Moreover, according to the technical contents described in the above-mentioned publication, it is not possible to quickly form a preparation state for the next liquid discharge after performing the liquid discharge with the generated heat which is practically important. As described above, the conventional method has advantages and disadvantages in terms of high-speed recording in configuration, multi-nozzle recording head, generation of satellite dots and occurrence of fogging of the recorded image, and is only used for applications that take advantage of the advantages. There was a constraint that it could not be applied. However, this is also based on Japanese Patent Application No.
The problem is solved by the method described in Japanese Patent Application Laid-Open No. 9-99. The method described in this publication is to heat ink in a liquid chamber to generate air bubbles to generate a pressure rise in the ink, and to eject ink from a fine capillary nozzle to perform recording. According to the invention, high-speed ink ejection can be obtained with good reproducibility from ejection nozzles arranged at high density for the first time.

In recent years, further improvements in production technology have progressed,
For example, in a multi-nozzle type ink jet head as disclosed in Japanese Patent Application Laid-Open No. 1-64857, a lid substrate (flow channel substrate) including a flow channel to a liquid chamber is formed by integral molding of a resin. It proposes to reduce the cost. However, there is still room for improvement in order to obtain a highly accurate lid substrate (flow path substrate).

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has as its object the first object of the invention is to form a lid substrate (flow channel substrate) comprising a flow channel to a liquid chamber integrally with a resin. It is an object of the present invention to increase the mechanical strength and obtain a more accurate lid substrate when formed by molding.

Secondly, another object of the present invention is to propose another structure for increasing the mechanical strength of the lid substrate and obtaining a more accurate one. Thirdly, it is an object of the invention to propose a configuration in which the mechanical strength of such a lid substrate is further increased to obtain a more accurate one.

Fourth, the present invention is preferably applied.
That is, the aspect of the invention is to regulate the aspect ratio of the lid substrate, which is effective in increasing mechanical strength and obtaining a more accurate one.
Fifth, the present invention is preferably applied, that is, the size of the lid substrate that is effective for increasing mechanical strength and obtaining higher accuracy is defined.

Sixth, the present invention is to regulate the size of the convex portion which effectively functions in the present invention. Seventh, another object of the present invention is to propose another configuration for further increasing the mechanical strength of the lid substrate and obtaining a more accurate one.

Eighth, in such a lid substrate, there is provided a further alternative configuration for further increasing the mechanical strength and obtaining a more accurate one.

Ninth, another object of the present invention is to propose another structure for further increasing the mechanical strength of the cover substrate and obtaining a more accurate one.

[0020]

According to the present invention, in order to achieve the above object, according to the first aspect of the present invention, a room for containing a recording liquid, a plurality of flow paths communicating with the room, A lid substrate forming a recording liquid inlet of the room,
The chamber and the flow path are engaged with the lid substrate to form the room and the flow path, and are provided corresponding to the flow path, generate bubbles in the recording liquid by heat, and generate a liquid by an action force accompanying an increase in the volume of the bubbles. A liquid jet recording head comprising a substrate having thermal energy generating means for discharging as small droplets,
The lid substrate is formed by integral molding of plastic together with the room, the recording liquid inlet, and the flow path. The outer wall surface of the lid substrate is provided with a rib having a convex shape along the longitudinal direction. did.

According to a second aspect of the present invention, there is provided a lid substrate formed with a chamber for accommodating a recording liquid, a plurality of flow paths communicating with the chamber, and a recording liquid inflow port of the chamber. Engages to form the chamber and the flow path, is provided corresponding to the flow path, generates bubbles in the recording liquid by heat, and discharges the liquid as small droplets by the action force accompanying the volume increase of the bubbles. Wherein the cover substrate is formed by integral molding of plastic together with the chamber, the recording liquid inlet and the flow path. A rib having a convex shape is provided along the longitudinal direction on the inner side of the room formed in (1). In the invention according to claim 3, in the first and second liquid jet recording heads, two or more ribs are provided.

According to a fourth aspect of the present invention, in the liquid jet recording head according to any one of the first to third aspects,
The rib is provided on an elongated lid substrate having an aspect ratio of the lid substrate of 5 times or more. In the invention of claim 5,
The liquid jet recording head according to any one of claims 1 to 4, wherein the rib is provided on an elongated lid substrate having a length of 35 mm or more.

According to a sixth aspect of the present invention, in the liquid jet recording head according to any one of the first to fifth aspects,
The rib is a convex-shaped rib having a height of at least 1/10 of the minimum thickness of the lid substrate. According to a seventh aspect of the invention, in the liquid jet recording head according to any one of the first to third aspects, the rib is provided at a diagonal position of the lid substrate.

According to the eighth aspect of the present invention, the second, third to sixth aspects are provided.
In the liquid jet recording head according to any one of the above, the rib is provided at a diagonal position of the room of the lid. According to a ninth aspect of the present invention, in the liquid jet recording head according to any one of the first to eighth aspects,
A flange is provided on the outer periphery of the lid substrate excluding the flow path tip.

[0025]

FIG. 1 is a diagram showing an example of a liquid jet recording head (ink jet recording head) to which the present invention is applied. FIG. 1A is a perspective view of the head, and FIG. 1C is a perspective view of the lid substrate viewed from the back side, FIG. 1D is a perspective view of the heating element substrate 2, and FIG. 2 is an inkjet head to which the present invention is applied. FIGS. 1A and 1B are diagrams for explaining the operation of a bubble jet head as an example, in which 1 is a lid substrate, 2 is a heating element substrate, 3 is a recording liquid inlet, 4 is an orifice, 5 is a flow path, and 6 is a flow path. A region for forming a liquid chamber, 7 is a rib, 8 is an electrode, 9 is a heating element (heater), 10 is ink, 11 is a bubble, and 12 is a flying ink droplet. This is applied to a liquid jet recording head.

First, the ink ejection by the bubble jet will be described with reference to FIG. 2. FIG. 2A shows a steady state, in which the surface tension of the ink 10 and the external pressure are in an equilibrium state at the orifice surface. FIG. 2B shows a state in which the heater 9 is heated, the surface temperature of the heater 9 rises sharply, the adjacent ink layer is heated until a boiling phenomenon occurs, and minute bubbles 11 are scattered. FIG. 2C shows a state in which the adjacent ink layer, which is rapidly heated on the entire surface of the heater 9, instantaneously evaporates to form a boiling film, and the bubbles 11 grow. At this time, the pressure in the nozzle rises by the amount of the bubble growth, and the balance with the external pressure on the orifice surface is broken, and the ink column starts to grow from the orifice. FIG. 2D shows a state in which the bubble has grown to a maximum, and the ink 10 corresponding to the volume of the bubble is pushed out from the orifice surface. At this time, no current is flowing through the heater 9, and the surface temperature of the heater 9 is decreasing. The maximum value of the volume of the bubble 11 is slightly delayed from the timing of applying the electric pulse. FIG. 2E shows a state where the bubble 11 is cooled by ink or the like and starts to contract. The leading end of the ink column moves forward while maintaining the extruded speed, and at the rear end, the ink flows backward from the orifice surface into the nozzle due to a decrease in the internal pressure of the nozzle due to the contraction of the bubble, and the ink column is constricted. . FIG. 2F shows a state in which the bubbles 11 further contract, the ink comes into contact with the heater surface, and the heater surface is cooled more rapidly. Since the external pressure is higher than the internal pressure of the nozzle at the orifice surface, a large meniscus has entered the nozzle. The tip of the ink column becomes a droplet 12 and flies in the direction of the recording paper at a speed of 5 to 10 m / sec. FIG. 2 (G) shows that the bubbles have completely disappeared in the process in which the ink is again supplied (refilled) to the orifice by capillary action and returns to the state of FIG. 2 (A). Thus, the present invention is characterized in that, as shown in FIG. 1, for example, the lid substrate 1 is formed by molding plastic, and a rib 7 having a convex shape is provided on the outer wall surface thereof along the longitudinal direction. I do.

In the present invention, the lid substrate 1 is made by molding plastic. For example, resins such as polysulfone, polyethersulfone, polyphenylene oxide, polypropylene, and polyimide are preferably used. As is well known, plastic is not very rigid. Therefore, when such a lid substrate 1 is small, it does not cause much problem. However, when the lid substrate 1 is large to a certain extent, as a disadvantage due to the fact that the rigidity is not so high, when the head is completed by laminating on a heating element substrate, deformation, etc. And the accuracy cannot be maintained, and the ink ejection performance varies from one ejection port to another. In extreme cases, the liquid chamber or the flow path sealing function is impaired, and ink leakage occurs. May occur. One way to avoid this is to increase the mechanical strength of the plastic material by putting a filler in the material, but in the present invention, by increasing the mechanical strength from the structural aspect, Has achieved its purpose.

First, the present invention relates to a so-called multi-nozzle head in which a plurality of nozzles / heating elements are arranged.
In addition, the present invention is applied not only to a so-called short array head having several tens to two hundred and three hundred nozzles / heat generating elements, but also to a mid array and a large array head having five hundred to several thousand nozzles. Thus, the number of nozzles / heating elements is 500-
In thousands of heads, the lid substrate 1 is elongated in the nozzle / heating element arrangement direction, and the mechanical strength cannot be maintained to maintain the dimensions of the flow path and the like with high accuracy. However, according to the present invention, since the rib 7 having the convex shape is provided on the outer wall surface along the longitudinal direction, it is possible to sufficiently reinforce the rib. As shown in FIG. 3, the cross-sectional shape of the rib is not a perfect rectangle, but rather a trapezoidal shape, and the corner portion has a rounded shape.
This is because the mold releasability from the mold is taken into account when manufacturing the lid substrate 1 by molding plastic.

Further, since the provision of the ribs 7 having a convex shape as in the present invention can be realized only by making the mold like that, it becomes a particularly difficult processing method or significantly increases the cost. There is an advantage that there is no such thing. In addition, in the example of FIG. 1, the tip of the flow path is the ink discharge port (orifice) 4, but as shown in FIG.
The ink ejection port 14 is formed on the resin film 13 bonded to the end face.
The head may have a configuration in which a hole is formed. The resin film 13 may be joined via a suitable joining member, or the resin material itself may be joined by thermocompression bonding. Further, the resin film 13 may be formed together when the cover substrate 1 is formed (FIG. 4B). By doing so, the labor for joining the resin film 13 to the lid substrate 1 can be omitted.

The resin film 13 has a discharge port 14
A method of irradiating an excimer laser is preferably used. For example, a resin such as polysulfone, polyethersulfone, polyphenylene oxide, polypropylene, or polyimide is irradiated with an excimer laser to remove the resin. Obtained by: According to this method, very precise processing along a mask pattern (in this example, a round pattern) can be performed. Although the discharge port 14 has a round shape here, the discharge port that can be used in the present invention is not limited to this shape, and an arbitrary shape such as a triangle or a square can be selected. The order in which the discharge port 14 is formed by irradiating the excimer laser may be used. The resin film 13 having the discharge port 14 formed in advance may be bonded to the end face, or the excimer laser irradiation may be performed after the resin film 13 is bonded to the end face. Alternatively, the discharge port may be formed. In the case where the resin film 13 is formed together with the lid substrate 1 as shown in FIG. 4B, the head may be formed by forming the discharge port and then laminating and joining the heating element substrate 2. After forming the head by lamination bonding with the substrate 2, the discharge port may be formed. (FIG. 4
(C)).

FIG. 5 shows another embodiment of the present invention. In this embodiment, a rib 7 having a convex shape is provided inside the lid substrate 1, that is, in the common liquid chamber 6. As shown in FIG. As described above, even in the common liquid chamber 6, there is an effect similar to that in the case where it is provided on the outer wall surface. Furthermore, when the cover substrate 1 is provided in the common liquid chamber 6 as described above, the outer wall surface of the cover substrate 1 can be in a state without any irregularities when the cover substrate 1 is laminated on the heating element substrate and pressed to complete the head. There is an advantage that the cover substrate 1 can be easily pressed without any obstruction.

Further, in the present invention, two or more ribs 7 having such a convex shape are provided. Specifically, as shown in FIG. 1 or FIG. 5, two or more recording liquid inflow ports 3 provided in the common liquid chamber 6 are provided. By doing so, the mechanical strength of the lid substrate 1 is further increased, and when completed as a head, the dimensions of the highly accurate flow path 5 and the like can be maintained without being impaired. A head is realized, and high-quality recording becomes possible. Although the figure shows an example in which the number of the recording liquid inlets 3 is one, the number of the recording liquid inlets 3 may be 2 if necessary (depending on the number of nozzles / heating elements).
Or more.

Next, another feature of the present invention will be described. As described above, the present invention is not applied to a short array head, but is applied to a mid array and a large array head. That is, in such a head having 500 to thousands of nozzles / heating elements, the lid substrate 1 has a rectangular shape elongated in the nozzle / heating element array direction. Various types of heads were made to clarify the effect of the present invention, that is, the effect of reinforcement by providing the ribs 7 having a convex shape when the length of the head becomes long. The prototype head is as shown in Fig. 1,
Prototype heads were prepared by preparing a lid substrate with and without a rib 7 having a convex shape. The nozzle / heating element array density was 400 dpi. The ribs 7 were two parallel ribs as shown in FIG. The size of the rib 7 is 1mm in width and height
1 mm. The size of the lid substrate is 7 mm in width, and the length in the nozzle / heating element arrangement direction is 7 mm or more depending on the number of nozzles / heating elements.
A sample having a thickness of 198 mm was prepared, and the effect of the presence or absence of the rib was examined. The results are shown below.

As is clear from Table 1, when the cover substrate is not so large (not long and thin), a high-precision cover substrate can be obtained without providing ribs, and the ejection performance is good. Above this point, those without ribs have poor ejection performance, and when configured as a head, some ink leaks occur. When the length is longer than a certain length, the accuracy of the lid substrate cannot be maintained without reinforcement by ribs, so that the adhesion with the heating element substrate becomes incomplete, and the airtightness between adjacent flow paths deteriorates. If the ejection performance is not good, or if the degree (adhesion incompleteness due to a decrease in accuracy) becomes severe, the ink leaks.

Here, the ejection performance defect means that there is a large variation in the ejection performance (for example, the ink droplet flying speed, the shape of the flying ink column, etc.) between the nozzles. In order to avoid such a situation, it is understood from Table 1 that when the aspect ratio of the lid substrate is 5 times or more, reinforcement by the rib must be performed. Alternatively, when the length of the elongated cover substrate is 35 mm or more, it is understood that the ribs must be reinforced. Table 1 No. Width Length Nozzle / number of heating elements Presence / absence of ribs Ejection performance Ink leak 17 mm 7 mm 64 None Good None 27 mm 7 mm 64 Yes Good None 3 7 mm 11 mm 128 None Good None 4 7 mm 11 mm 128 Yes Good None 5 7 mm 256 mm No Good No No 6 7mm 19mm 256 Yes Good No 7 7mm 35mm 512 No Bad No 8 7mm 35mm 512 Yes Good No 9 7mm 67mm 1024 No Bad Yes 10 7mm 67mm 1024 Yes Good 7No 12 7 Good none

Next, still another feature of the present invention will be described. Here, in order to study the size of the rib which is a feature of the present invention, a head was prototyped by changing the thickness of the lid substrate and the height of the rib, and good / defective ink ejection performance was examined. The sizes of the prototype heads are the same as those of No. 8 and No. 12 in Table 1. That is, width 7mm x length 35mm and width 7mm
X A lid substrate of 198 mm in length. The arrangement density of the nozzles / heating elements is also 400 dpi. The ribs were also arranged in two parallel ribs. The width of the rib was 1 mm. In the lid substrate, the common liquid chamber portion occupies most of the area, and the thickness of the common liquid chamber portion is usually the smallest. Therefore, here, the relationship between the thickness of the common liquid chamber portion and the height of the rib was examined.

As is clear from Table 2, the height of the rib is
It can be seen that good ink ejection performance can be obtained with a head having a thickness of 1/10 or more of the thickness of the common liquid chamber. In other words, there is no reinforcing effect unless the ribs are larger than a certain size,
It was found that the accuracy of the lid substrate could not be maintained. Table 2 No. Size of lid substrate Common liquid chamber thickness Nozzle / number of heating elements Rib height Discharge performance 1 Width 7mm x Length 35mm 2mm 512 0mm Failure 2 Width 7mm x Length 35mm 2mm 512 0.1mm Failure 3 Width 7mm x length 35mm 2mm 512 0.2mm good 4 width 7mm x length 35mm 2mm 512 0.3mm good 5 width 7mm x length 35mm 2mm 512 0.5mm good 6 width 7mm x length 35mm 2mm 512 1mm good 7 width 7mm x length 198mm 3mm 3072 0mm defective 8 width 7mm x length 198mm 3mm 3072 0.1mm defective 9 width 7mm x length 198mm 3mm 3072 0.2mm defective 10 width 7mm x 198mm 3mm 3072 0.3mm good 11. 7mm × Length 198mm 3mm 3072 0.5mm Good 12 Width 7mm × Length 198mm 3mm 3072 1mm Good

Next, still another feature of the present invention will be described. FIG. 6 shows an example. Here, the arrangement of the ribs, which is a feature of the present invention, is provided at diagonal positions formed by the lid substrate. By arranging such ribs, there is an advantage that the mechanical strength against torsion is improved as compared with a case where the ribs are simply arranged in parallel. Dimensional accuracy can be maintained, and a high-performance liquid jet recording head can be realized. FIG. 6 schematically shows a lid substrate for explaining the idea of providing ribs at diagonal positions. FIG. 7 shows an example in which the ribs are arranged at diagonal positions formed by the chamber of the lid substrate, that is, the common liquid chamber. In this case, the same effect can be obtained. FIG. 7 also schematically shows the lid substrate for explaining the concept of providing the ribs at diagonal positions.

Next, still another feature of the present invention will be described. FIG. 8 shows an example. In this example, a flange 15 is provided on the outer periphery of the lid substrate except for the flow path tip. Even in this case, the mechanical strength of the lid substrate can be increased as in the case where the rib is provided on the outer wall surface or the inner wall surface (common liquid chamber surface) of the lid substrate as described above, and the dimension of the flow path and the like can be increased. Accuracy can be maintained, and a high-performance liquid chamber ejection recording head can be realized. Also, in this case, as in the case of providing the ribs, since it can be realized only by forming the mold in such a shape, there is an advantage that there is no particularly difficult processing method or a significant increase in cost. is there.

[0040]

According to the first aspect of the present invention, since a rib having a convex shape is provided along the longitudinal direction on the outer wall surface of the lid substrate of the liquid jet recording head, the lid comprising the flow path to the liquid chamber is provided. When the substrate is formed by integral molding of resin, the mechanical strength can be increased. As a result, the lid substrate after molding is reduced in deformation and the like, and can be made very high precision. In the case where the liquid jet recording head is configured in combination with the heating element substrate, there is no ink leakage or the like. It is possible to obtain a high-precision liquid jet recording head having good droplet discharge performance.

According to the second aspect of the present invention, a high-precision lid substrate having high mechanical strength can be obtained in the same manner as the first aspect of the present invention, whereby a high-precision liquid jet recording head can be obtained. Since the convex-shaped rib is provided on the liquid chamber side of the lid substrate, it is not necessary to provide the convex portion on the outer wall surface of the lid substrate, so that the lid substrate is laminated and pressed on the heating element substrate. In addition, when the head is configured, there is no obstacle and the structure is easy to press.

According to the third aspect, since two or more ribs are provided on the lid substrate of the liquid jet recording head,
The mechanical strength could be further increased, and a liquid jet recording head manufactured thereby could be obtained with higher precision and better ink droplet ejection performance.

According to the fourth aspect of the present invention, when the elongated cover substrate having an aspect ratio of 5 times or more is formed by integral molding of resin, the ribs are provided, so that the number of nozzles is large and the elongated large substrate is provided. Even in the case of an array head, the lid substrate has high mechanical strength, so that a very high-precision liquid jet recording head can be obtained.

According to the fifth aspect of the present invention, the ribs are provided when the elongated cover substrate having a length of 35 mm or more in the nozzle arrangement direction is formed by integral molding of resin, so that the number of nozzles is large. Even in the case of an elongated large array head, the lid substrate has high mechanical strength, and a very high-precision liquid jet recording head can be obtained.

According to the sixth aspect of the present invention, the height of the rib provided on the lid substrate of the liquid jet recording head is set to be at least 1/10 of the minimum thickness of the lid substrate. As a result, a liquid jet recording head manufactured by using the same was able to obtain a liquid jet recording head with higher accuracy and excellent ink droplet ejection performance.

According to the seventh aspect of the invention, the ribs are provided on the cover substrate of the liquid jet recording head at diagonal positions of the cover substrate, so that the mechanical strength against twisting is improved. An even stronger lid substrate is obtained,
The liquid jet recording head manufactured thereby could also obtain a head with higher accuracy and better ink droplet ejection performance.

According to the eighth aspect of the present invention, since the ribs are provided on the cover substrate of the liquid jet recording head at diagonal positions of the room of the cover substrate, the mechanical strength against twisting is improved. As a result, a substrate having higher strength was obtained, and a liquid jet recording head manufactured with the substrate was able to obtain a liquid jet recording head with higher precision and better ink droplet ejection performance.

According to the ninth aspect, since the flange is provided on the outer periphery of the lid substrate of the liquid jet recording head except for the front end of the flow path, the mechanical strength can be further increased, and the manufacturing can be performed thereby. As a result, a liquid jet recording head with higher precision and good ink droplet ejection performance could be obtained.

[Brief description of the drawings]

FIGS. 1A and 1B are a perspective view and an exploded perspective view of an essential part for explaining an embodiment of a liquid jet recording head.

FIG. 2 is a diagram for explaining an operation of a bubble jet head which is an example of a liquid jet recording head.

FIG. 3 is an enlarged perspective view of a main part for explaining the shape of a rib.

FIG. 4 is a perspective view showing another embodiment of the liquid jet recording head.

FIG. 5 is a perspective view of an essential part for describing the arrangement of ribs in a liquid chamber of a lid substrate.

FIG. 6 is a simplified diagram for explaining the arrangement of ribs on a lid substrate.

FIG. 7 is a simplified diagram for explaining an arrangement of ribs in a liquid chamber of a lid substrate.

FIG. 8 is an essential part perspective view for explaining a flange of the lid substrate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Lid board | substrate, 2 ... (heating element) board | substrate, 3 ... Recording liquid inflow port, 4 ... Orifice, 5 ... Flow path, 6 ... Area (common liquid chamber) for forming a liquid chamber, 7 ... Rib, 8 .. Electrodes, 9 heating elements (heaters), 10 inks, 11 bubbles, 12 flying ink droplets, 13 resin film, 14 discharge ports (formed by excimer laser irradiation), 15 flanges.

Claims (9)

[Claims] A lid substrate forming a chamber for accommodating a recording liquid, a plurality of flow paths communicating with the chamber, and a recording liquid inflow port of the chamber; A heat source for forming a chamber and the flow path, provided corresponding to the flow path, generating air bubbles in the recording liquid by heat, and discharging the liquid as small droplets by an action force accompanying an increase in the volume of the air bubbles; In a liquid jet recording head comprising a substrate having energy generating means, the lid substrate is formed by integral molding of plastic with the chamber, recording liquid inlet, and flow path, and the outer wall surface of the lid substrate A liquid jet recording head provided with a rib having a convex shape along the longitudinal direction. 2. A lid substrate that forms a room for containing a recording liquid, a plurality of flow paths communicating with the room, and a recording liquid inflow port of the room; And thermal energy for forming the flow path, provided corresponding to the flow path, generating bubbles in the recording liquid by heat, and discharging the liquid as small droplets by the action force accompanying the increase in the volume of the bubbles. In the liquid jet recording head comprising a substrate having a generating means, the lid substrate is formed by integral molding of plastic with the chamber, recording liquid inlet and flow path, and the chamber formed on the lid substrate A liquid jet recording head, characterized in that a rib having a convex shape is provided along the longitudinal direction inside the recording head. 3. The liquid jet recording head according to claim 1, wherein two or more ribs are provided. 4. The liquid jet recording head according to claim 1, wherein the rib is provided on an elongated lid substrate having an aspect ratio of the lid substrate of 5 times or more. . 5. The liquid jet recording head according to claim 1, wherein the rib is provided on an elongated lid substrate having a length of 35 mm or more. 6. The method according to claim 6, wherein the rib is one-third of a minimum thickness of the lid substrate.
The liquid jet recording head according to any one of claims 1 to 5, wherein the rib is a convex-shaped rib having a height of 10 or more. 7. The liquid jet recording head according to claim 1, wherein the rib is provided at a position on a diagonal line of the lid substrate. 8. The apparatus according to claim 2, wherein said rib is provided at a diagonal position of a room of said lid substrate.
The liquid jet recording head according to any one of the above items. 9. The method according to claim 1, wherein a flange is provided on an outer periphery of the lid substrate except for a front end portion of the flow path.
The liquid jet recording head according to any one of the above items.