JP2000280476A - Ink jet print head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet print head of a roof chuter type advantageous to high-density printing which can discharge ink drops with a good energy efficiency and in which a diaphragm or the like can be correctly and easily set with a high aspect ratio. SOLUTION: An ink feed path 38 and an ink feed-and-transfer hole 39 each shaped like a groove are formed to a printing head before the middle of a production process. Seal diaphragms 40 for sealing ink inside are formed to a common electrode arrangement part at the left side of the ink feed path 38 and to an individual wiring electrode arrangement part at the right side. A channel diaphragm 40-1 and section diaphragms 40-2 which are lower by 1/3 a height of the seal diaphragm are connected, whereby a pressure chamber is formed having an opening communicating with an ink channel 42 and surrounding the whole periphery in a horizontal direction of each heating resistor 35 by the diaphragms continuous in the horizontal direction. Thereafter, an orifice plate is layered on the pressure chamber to form nozzles to an opposite part to each heating resistor 35. Since the diaphragms surrounding the pressure chamber are continuous in the horizontal direction, the diaphragm is hard to collapse in the production process and a discharge energy is concentrated to a vertical direction where the nozzles are present.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a roof shooter type ink jet print head having good thermal energy efficiency when ejecting ink droplets under the pressure of thermonuclear bubbles.

[0002]

2. Description of the Related Art In recent years, ink jet printers have been widely used. The printer using the ink jet system includes a pressurizing unit for pressurizing and discharging ink. The configuration of the pressurizing unit includes a thermal jet system in which ink droplets are ejected by the force of air bubbles and a piezo system in which ink droplets are ejected by deformation of a piezoresistive element (piezoelectric element).

[0003] The printing method using these structures is a process in which ink as a color material is formed into ink droplets and ejected directly to recording paper. Energy is low, colorization is easy by mixing inks, print dots can be made small, high image quality, and there is no waste in the amount of ink used for printing and excellent cost performance. This is a printing method widely used as a personal printer.

[0004] The above-mentioned thermal jet system has two configurations depending on the ejection direction of ink droplets. That is, there are a configuration in which ink is ejected in a direction parallel to the heat generating surface of the heat generating unit as a pressurizing unit, and a configuration in which ink is discharged in a direction perpendicular to the heat generating surface of the heat generating unit.

FIGS. 8 (a), 8 (b) and 8 (c) show a structure in which the ink is discharged in a direction parallel to the heat generating surface of the heat generating portion.
(f) schematically shows a configuration in which the discharge is performed in a direction perpendicular to the heat generation surface of the heat generation unit. Figure (a) or (d)
As shown in FIG. 1, a heat generating portion (heat generating element) 2 is formed on a silicon substrate 1, and an orifice plate 3 is formed facing the silicon substrate 1. An orifice 4 is formed on the side of the heating element 2 in FIG. 1A, and is opposed to the heating element 2 in FIG. Heating element 2 above
Is connected to an electrode (not shown), and the ink 5 is always supplied to the ink flow path in which the heating element 2 is provided.

In order to discharge ink droplets from the orifice 4, first, as shown in FIG. 2B or 2E, the heating element 2 is heated by energization according to image information, and Nucleus bubbles are generated, and the nucleus bubbles are united to form a film bubble 6. The film bubble 6 adiabatically expands and grows to push the surrounding ink, whereby the ink 5 'is pushed out from the orifice 4. The pushed ink 5 'is ejected from the orifice 4 toward the paper surface as an ink droplet 7, as shown in FIG. 7 (c) or (f). After that, the grown film bubble is shrunk by the heat of the surrounding ink, and finally the film bubble disappears and waits for the next heating element to be heated. This series of steps is performed instantaneously.

The above-described structure in which ink droplets are ejected in a direction perpendicular to the heat-generating surface of the heat-generating element is called a roof-shooter type thermal ink-jet head, and it is known that power consumption is extremely small. . In addition, as a method of manufacturing this roof shooter type thermal ink jet head, a silicon LSI forming technology and a thin film forming method are used on a large number of chip substrates (for example, 90 or more wafers having a diameter of 6 inches or more) partitioned on a silicon wafer. There is a method in which a plurality of heating elements, a driving circuit for individually driving the heating elements, and an orifice corresponding thereto are monolithically formed by using a forming technique.

FIG. 9 (a) shows a roof shooter type thermal ink jet head (hereinafter, referred to as a "printer").
FIG. 4B is a side sectional view showing a schematic configuration of an ink discharge head. FIG. 4B is a sectional view taken along the line AA ′ in FIG. 4A, and FIG. It is a reduced plan view shown by removing.

FIG. 10 is an enlarged perspective view showing the internal structure of the above-mentioned conventional ink jet printer head, in which the orifice plate is cut upward to be easily understood. As shown in FIGS. 9 (a), 9 (b), 9 (c) and 10, the ink discharge head 10 has a drive circuit 12 composed of an LSI formed on a chip substrate 11 (see FIG. 9 (a)). And a heating resistor 13 made of a thin film, the heating resistor 13 and the driving circuit 12
And a common electrode 15 which is a common wiring for grounding, and the partition wall 1 laminated thereon.
6, 17 (17a, 17b) and an orifice plate 18 laminated thereon. A discharge nozzle (orifice) 19 is formed in the orifice plate 18.

Each of the heating resistors 13 includes a partition 17a corresponding to a comb body of a comb-shaped partition 17 formed on the individual wiring electrode 14 side and a partition 17b corresponding to a comb tooth portion having a width w extending therefrom. Is arranged in the small chamber 21 defined by
It is isolated from another adjacent heating resistor 13. Then, parallel to the direction in which the heating resistors 13 are arranged,
1, an ink flow path 22 is formed on the side of the opening, and an ink supply groove 23 is formed so as to communicate with the ink flow path 22. Further, the ink supply groove 23 communicates with the ink supply groove 23 and penetrates the lower surface of the substrate. A hole 24 is drilled.

The heating resistors 13 in the isolated small chambers 21 are provided with ink supply holes 24 and ink supply grooves 23 from an ink cartridge (not shown) connected to the ink supply holes 24 on the back surface of the substrate. And the ink is supplied through the ink flow path 22. The heating resistor 13 is connected to the drive circuit 12.
Is selectively driven via the individual wiring electrodes 14 to generate heat, and film bubbles are generated, and the ink is ejected from the ejection nozzles 19 toward the sheet surface (not shown) by the pressure.

By the way, as the colorization of printers has progressed as in recent years, the printers have correspondingly required 720 color printers.
A high resolution of at least dpi or 800 dpi is required. In order to realize such a high print dot density, it is necessary to further increase the density of juxtaposed pressure parts (heating resistors 13). For that purpose, the width w of the partition wall 17b must be made small (small) to narrow the space between the small chambers 21, and the density of the resistance heating portions 13 to be arranged side by side must be increased. That is, the aspect ratio t / w between the width w and the height t of the partition wall 17b must be increased.

However, the aspect ratio t / w is expressed as “t / w =
If it is set to 1.0 or more, the partition wall 17b becomes insufficient in strength, particularly in the photolithography developing step during the manufacturing process, and collapses or falls down, so that a partition wall of a desired shape is not formed. Causes an obstacle in the distribution of ink to the ink. That is, when the aspect ratio t / w is “t / w =
It is difficult to form the partition 17b so as to have a thickness of 1.0 or more from the viewpoint of the strength of the photosensitive resin as a material of the partition.

Therefore, in order to increase the arrangement density of the heating resistors 13 and to reduce the aspect ratio t / w of the partition 17b to less than 1.0, the width w of the partition 17b is not changed and is maintained as usual. It has been considered that there is no method corresponding to higher resolution other than a method of making the arrangement density of the heating resistors 13 denser by narrowing the small chambers 21 partitioned by the partition walls 17b.

[0015]

However, in order to increase the arrangement density of the heating resistors 13 as described above, the partition walls 17 are required.
When the size of the small chamber 21 partitioned by b is narrowed, the small
The size of the heat generating resistor 13 arranged in 1 also becomes narrow. Then, a new problem arises in that it is difficult to secure the area of the heating resistor 13 necessary for properly ejecting ink droplets.

On the other hand, as shown in FIG.
Since the small chamber 21 has no partition wall on the ink flow path 22 side and has one side of the ink flow path 22 open out of the four sides, the heating nucleus 13 generates heat nucleated bubbles from the initial stage of heating when the heating nuclei bubble is generated. In addition, the pressure of the ink discharge bubbles is partially dispersed so as to flow backward through the ink supply ink flow path 22 from the above-described full opening in the horizontal direction different from the vertical ink discharge direction. For this reason, there has been a problem that the energy efficiency for discharging the ink is reduced. As a measure for solving this problem, it has been proposed to provide a partition wall for preventing the pressure from being released at the ink inlet port. Such a partition wall is similar to the above-described partition wall or independently provided. For this reason, it has a problem that it is easily collapsed in the manufacturing process more than the partition wall.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances,
It is an object of the present invention to provide a roof shooter type ink jet print head which can discharge ink droplets with high energy efficiency, and which can accurately and easily stand up partitions and the like with a high aspect ratio and which is advantageous for high printing density.

[0018]

The construction of the ink jet print head of the present invention will be described below. An ink jet print head according to the present invention includes a plurality of heating elements for generating thermal energy for ejecting ink disposed at predetermined positions on a substrate, and each of the plurality of heating elements is individually formed around the entire circumference in the horizontal direction. A partition wall for forming a pressure chamber for applying pressure to ink by generating air bubbles by each heating element, and a partition wall facing the substrate via the partition wall. An orifice plate having an ink discharge nozzle formed at a position corresponding to the heating element, and a common flow path that communicates with each of the pressurizing chambers through the openings and feeds ink to be supplied to the pressurizing chamber. It is configured to have.

The opening is formed by removing an end of the partition wall on the side of the orifice plate, for example, as described in claim 2. Are formed by removing the ends of the. When the substrate side end is removed, the portion of the partition wall where the opening is provided is provided on the orifice plate, for example.

The partition may surround the heating element in a rectangular shape, and the opening may extend over three sides except one side of the partition opposite to the common flow path. Provided.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1A, 1B, and 1C are diagrams showing a method of manufacturing a thermal ink jet head according to the first embodiment in the order of steps, each of which is formed on a silicon chip substrate in a series of steps. FIG. 3 schematically shows a schematic plan view and a cross-sectional view of a state in which the semiconductor device is moved. In these figures, for convenience of explanation, only one print head of the thermal ink jet head for full color (the same as the structure of the ink jet head for monochrome) is shown, but actually, as will be described later. A plurality of such print heads (usually four print heads) are
It is formed on individual substrates (silicon chips). FIG. 3 (c) shows 36 ink discharge nozzles (orifices) 4
4 is shown, but actually 128 or 256 are formed in a line.

FIGS. 2 (a), (b) and (c) are shown in FIG. 1 (a), (b) and
2 (a), 2 (b), and 2 (c) are views taken along the line AA 'in FIG. ), The lower part is a cross-sectional view taken along the line BB ′ of the upper part (the same figure).
(See (a)). 1A, 1B, and 1C are the same as the cross-sectional views shown below FIGS. 1A, 1B, and 1C, respectively. 2 (a), 2 (b) and 2 (c), 128 or 256 orifices are represented by 5 orifices for the sake of illustration.

In this method of manufacturing a thermal ink jet head, first, as a step 1, a drive circuit and its terminals are formed on a silicon substrate of 4 inches or more by an LSI forming process, and an oxide film having a thickness of 1 to 2 μm is formed. ,next,
In step 2, a resistive film made of Ta (tantalum) -Si (silicon) -O (oxygen) and an electrode film made of Ti / W are formed by using a thin film forming technique, and a wiring portion is formed on the electrode film by photolithographic technique. Is formed, and a fine heating resistor (pressing portion) pattern is formed on the resistance film.
In this step, the position of the heating resistor is determined.

FIGS. 1 (a) and 2 (a) show a state immediately after the above steps 1 and 2 have been completed. That is, a common electrode 32, a common electrode power supply terminal 33 (see FIG. 1A), individual wiring electrodes 34, a large number of heating resistors 35, a drive circuit 36, and a drive circuit terminal 37 are provided on the chip substrate 31.
(See FIG. 1A).

Subsequently, in step 3, the individual heating elements 3
A partition member made of an organic material such as photosensitive polyimide is formed to a height of about 20 μm by coating so as to form an ink reservoir (small tuft) corresponding to 5, and this is etched in two steps using two masks. After patterning by heating, curing (dry curing, baking) by applying heat at 300 ° C. to 400 ° C. for 30 minutes to 60 minutes is performed, and a seal partition wall made of the photosensitive polyimide having a height of 10 μm and a lower height than this are formed. A partition for partition is formed and fixed on the chip substrate.
This patterning can also be performed by laser processing.

Further, in step 4, a groove-like ink supply path is formed on the surface of the chip substrate by wet etching or sand blasting, and an ink supply hole communicating with the ink supply path and opening on the lower surface is formed. I do.

FIGS. 1 (b) and 2 (b) show a state immediately after the steps 3 and 4 are completed. That is, the groove-shaped ink supply path 38 and the ink supply hole 39 are formed, and the common electrode 3 located on the left side of the ink supply path 38 is formed.
Seal partition walls 40 for sealing the ink inside are formed in the two portions and the portion where the individual wiring electrodes 34 on the right side are provided. Partition wall 40-for partitioning the heating resistor 35
2 and flow path side partition 40 separating the section from the ink flow path
-1 are continuously provided.

FIG. 3 is an enlarged perspective view showing the state immediately after the completion of the steps 3 and 4 shown in FIGS. 1 (b) and 2 (b). As shown in FIG. 2 (b) and FIG. 3, the partition wall 40-2 extending and laminated between the respective heating resistors 35 can be formed by a comb if the flow path side partition 40-1 is a comb body. , And the tips of the teeth of the comb abut against the seal partition wall 40 and are integrated.

As a result, the fine teeth (compartments) 41 in which the heating resistors 35 are located between the teeth are formed by the number of the heating resistors 35 with the comb teeth as partition walls. The seal partition wall 40 also serves as one side of the partition wall forming the small chamber 41.

Thereafter, in step 5, an orifice plate of a polyimide film having a thickness of 10 to 30 μm is coated on one surface thereof with a thermoplastic polyimide as an adhesive to a very thin thickness of, for example, 2 to 5 μm. The orifice plate is fixed to the uppermost layer of the laminated structure by applying pressure while heating at 390 to 300 ° C. Then, Ni, Cu
Alternatively, a metal film such as Al having a thickness of about 0.5 to 1 μm is formed.

Further, as a step 6, the metal film on the orifice plate is patterned to form a mask for selectively etching the polyimide.
A plurality of nozzle holes (orifices) are collectively formed by making holes of 40 μmφ to 39 μmφ by dry etching such as R according to the above metal film mask. The holes may be formed using an excimer laser or the like.

FIGS. 1 (c) and 2 (c) show the process 5 described above.
And the state immediately after the end of step 6. That is, the orifice plate 43 covers the entire area except for the power supply terminals 33 and 37, and the seal partition 40, the partition partition 4
0-2 and the small chamber 41 formed by the channel side 40-1 are also covered, and the thickness (height) of the seal partition wall 40 is formed.
A fine individual tuft having a height corresponding to 10 μm is formed, and the flow path side partition 40-1 and the partition partition 40-2 have a shape in which the end of the partition from the top to the bottom on the orifice plate 43 side is removed. The removed portion forms an opening of the small tuft 41.

An ink flow path 42 having a height of 10 μm is formed to connect the opening of the small chamber 41 with the ink supply path 38. In the orifice plate 43, an ink discharge nozzle (orifice) 44 is formed by dry etching at a portion corresponding to the heating resistor 35.

As a result, a large number of monocolor heads 45 having 128 or 256 ink ejection nozzles 44 in one row are completed on a silicon wafer. By using a metal film such as Ni, Cu, or Al as a mask for dry etching, a selectivity between a resin and a metal film of about 100 can be obtained. Therefore, it is sufficient to form a mask with a metal film of 1 μm or less for etching a 39 to 40 μm polyimide film.

The processing so far is performed in the state of a wafer.
Finally, as a step 7, the silicon wafer is cut using a dicing saw or the like, divided into individual chip substrate units, and die-bonded to a mounting substrate.
By connecting the terminals, a practical unit of the inkjet head is completed.

As described above, one row of ink discharge nozzles 44
The mono-color head 45 having a black-and-white ink-jet head has a configuration of a monochrome ink-jet head. Usually, in full-color printing, the three primary colors of subtractive color mixing, yellow (Y), magenta (M), and cyan (C), And black (Bk) dedicated to the black part of the image, and a total of four colors of ink are required. Therefore, at least four nozzle rows are required. According to the above-described manufacturing method, it is possible to form a full-color head by monolithically connecting four mono-color heads 45 in four rows, and the positional relationship of each row can be accurately determined by today's semiconductor manufacturing technology. It is possible to arrange.

As shown in FIG. 3, the ink jet print head has its small chamber 41 which has an opening above three sides and is surrounded by a continuous partition in the horizontal direction. When a thermonuclear bubble is generated by heating the heating resistor 35, the pressure of the ink discharge bubble is induced in the vertical direction and concentrates in the direction of the orifice 44. Therefore, the thermal energy of the bubble generation can be used for the ink ejection without waste, and the energy efficiency is improved.

The channel-side partition 40 forming the small chamber 41
-1 and the partition wall 40-2 are low in height (the height of the partition wall is 2/3 from top to bottom), and the aspect ratio t / w becomes small. The yield is improved without collapse.

Further, since the partition wall 40-2 is supported and reinforced at both ends in the horizontal direction by the seal partition wall 40 and the flow-path-side partition wall 40-1, the aspect ratio t / w is a certain value of "1". Even when the temperature exceeds the limit, no drop or collapse occurs during the firing / hardening process. That is, the width of the partition wall can be reduced, and the interval between the small chambers 41 can be reduced by that much.
As a result, it is possible to create a high-resolution print head by shortening the interval while maintaining the heat generating function of the heat generating resistor 35 at the same level as the current state.

For example, like the above-described partition walls having different heights between the seal partition wall 40 and the flow-path-side partition walls 10-1 and the partition partition walls 40-2, the partition walls having partially different heights have different masks. It can be easily formed by etching in stages.

FIGS. 4 (a) and 4 (b) show another example of the configuration of the small chamber 41 having openings on three sides and surrounded by a partition wall which is continuous in the horizontal direction as described above. FIG. Same figure
(a), the flow path side partition 47-1 and the partition partition 47-2,
An example is shown in which the partition from the top to the bottom is arranged in a shape in which the chip substrate 31 side is removed, and the opening 46 is provided below. In order to actually form the flow path side partition 47-1 and the partition partition 47-2 of this shape, the flow path side partition 47-1 and the partition partition 47-2 are formed on the back surface of the orifice plate 43 not shown in FIG. The orifice plate 43 is aligned on the substrate and laminated.

FIG. 3B shows an example in which the flow path side partition and the partition partition are arranged in a shape in which the middle of the partition from top to bottom is removed, and an opening 48 is provided at the center. I have.
As a result, the flow path side partition walls 49-1, 50-1 and the partition partition walls 49-2, which are arranged vertically as shown in FIG.
In the preparation of 50-2, the upper flow path side partition 49-1 and the partition partition 49-2 are disposed on the orifice plate side, and the lower flow path side partition 50-1 and the partition partition 50-2 are disposed on the substrate 31 side. Set up.

FIGS. 5 (a), 5 (b) and 5 (c) show an example of the structure of a small chamber 41 having an opening in the partition wall on the flow path side and surrounded by partition walls which are continuous in the horizontal direction as a whole. FIG.
As shown in FIGS. 7A, 7B and 7C, the partition walls 51-2 have a common shape and are arranged in a continuous shape from top to bottom. In FIG. 2A, the upper end of the flow path partition 51-1 is removed to form an upper opening 52, and in FIG. 2B, the lower end of the flow path partition 51-1 'is removed. An opening 53 is formed, and in FIG. 10C, a middle opening 54 is formed by removing a middle portion of the flow path-side partition 51-1 ″.

Also in this configuration, since a horizontal partition is surrounded by a continuous partition, when a thermonuclear bubble is generated by heating the heating resistor 35, the pressure of the ink discharge bubble is induced in the vertical direction and the orifice is formed. The thermal energy generated in the bubbles concentrated in the 44 directions can be used for ink ejection without waste, and the energy efficiency is improved.

FIG. 6 (a) is a plan view showing only one small tuft 41, FIG. 6 (b) is a side view of a shape that the above-mentioned channel-side partition and partition partition can take, and FIG. FIG. 4D is a side view of a shape that can be further adopted by the partition wall, and FIG. Here, FIG.
The position of the partition wall of the small tuft 41 shown in FIG.
(Or 47-1, 49-1, 50-1, 51-1, 51
-1 ', 51-1 ") at the position A, the partition 40-
2 (or 47-2, 49-2, 50-2, 51-2) is defined as position B.

FIGS. 7A, 7B, and 7C are diagrams showing combinations of partition shapes that can be taken at the position A of the flow path side partition and the position B of the partition partition by connecting broken lines. Hereinafter, this will be described. The position A on the flow channel side of the small tuft 41 shown in FIG.
Requires an opening. If there is no opening here, there is a possibility that crosstalk in which the ejection state is affected between adjacent small chambers may occur.

Therefore, at the position A, the shape k4 shown in FIG. 6C cannot be taken, but the shapes k1 and k shown in FIG.
Either 2 or k3 can be adopted. Fig. 7 (a),
(b) and (c) show this.

Further, since the position B may or may not have an opening, the position B may have a shape k1, k2 or k shown in FIG.
In addition to FIG. 3, a shape k4 shown in FIG. 7 (a), 7 (b) and 7 (c) show this as described above.

In the shape k5 shown in FIG. 6D, the partition wall surrounding the small chamber 41 is not continuous in the horizontal direction at either the position A or the position B, that is, at the position A or the position B, Of the partition wall. This shape is in a state of standing alone on the substrate before the orifice plate is installed, so that the aspect ratio t /
Even if w is small to a certain degree, it cannot be adopted because the partition walls will be dropped or collapsed in the course of firing and hardening. Fig. 7 (a), (b),
The fact that the shape k5 is not linked by a broken line in (c) indicates this.

As can be seen from the dashed line combination diagram in FIG. 7, the possible shapes of the flow path side partition and the partition partition are as shown in FIG. 4 (a) when both positions A and B shown in FIG. When both A and B have the shape k2, and when both the positions A and B shown in FIG. 4B have the shape k3, the positions A shown in FIGS. 5A, 5B and 5C correspond to the shapes k1 and k2. Or, it is not limited to the case where the position B is the shape k4 at k3. At positions A and B, the shapes k1 and k2
Alternatively, a configuration in which different shapes of k3 are combined may be employed.

The orifice side wall of the partition wall k2 or k3 can be formed integrally with the orifice plate.

[0052]

As described in detail above, according to the present invention, since the pressurizing chamber (small chamber) is formed so as to be partially surrounded by an opening and surrounded by a partition wall which is continuous in the horizontal direction, the pressure chamber is formed. Discharge energy can be concentrated in the vertical direction where the nozzles are located, while maintaining a smooth supply of ink to the pressure chambers (small chambers).
As a result, the discharge energy can be used for discharging the ink without waste, and the energy efficiency is improved.

Also, since the partition surrounding the pressurizing chamber is continuous in the horizontal direction and there is no isolated portion and each portion supports each other, even if the aspect ratio t / w exceeds "1" to a certain extent, the baking No drop or collapse occurs during the curing process, so the width of the partition walls can be narrowed and the spacing between the pressurizing chambers can be narrowed accordingly, thereby reducing the spacing while maintaining the function of the pressurizing chamber. Thus, a high-resolution print head can be manufactured accurately and easily.

[Brief description of the drawings]

FIGS. 1A, 1B, and 1C are schematic plan views and cross-sectional views schematically showing a method of manufacturing a thermal inkjet head according to a first embodiment in the order of steps.

2 (a), 2 (b) and 2 (c) are each an enlarged view of the plan view of FIGS. 1 (a), 1 (b) and 1 (c), and the upper part is an AA 'sectional arrow of the upper part. The lower part is a sectional view taken along the line BB 'of the upper part.

FIG. 3 is an enlarged perspective view for clearly illustrating a state immediately after manufacturing steps 3 and 4 are completed.

FIGS. 4 (a) and 4 (b) are diagrams showing another example of the configuration of a small chamber having openings on three sides and surrounded by a partition which is continuous in the horizontal direction.

FIGS. 5 (a), (b), and (c) are views showing an example of the configuration of a small chamber having an opening in a flow path-side partition and surrounded by a partition that continuously surrounds the horizontal direction as a whole. .

6 (a) is a plan view showing only one small tuft, FIG. 6 (b) is a side view of a shape that the channel-side partition and the partition partition can take, and FIG. 6 (c) is a side view of a shape that the partition partition can further take. (D) is a side view of a shape that is inappropriate for both the flow path side partition and the partition partition.

FIGS. 7 (a), (b), and (c) are combination connection diagrams showing combinations of shapes that can be taken by the flow path side partition and the partition partition.

8 (a), (b), and (c) are diagrams showing a configuration in which ink is ejected in a direction parallel to the heat generating surface of the heat generating unit, and FIGS. 8 (d), (e), and (f) are diagrams of the heat generating unit. FIG. 3 is a diagram illustrating a configuration for ejecting ink in a direction perpendicular to a heat generating surface.

9A is a side sectional view showing a schematic configuration of a conventional roof shooter type thermal inkjet head, and FIG.
(a) is a cross-sectional view taken along the line AA ', and (c) is a reduced plan view with a part thereof removed.

FIG. 10 is an enlarged perspective view showing an orifice plate separated upward to clearly show the internal structure of the roof shooter type thermal ink jet head of the present invention which is the subject of the invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Silicon substrate 2 Heating part (heating element) 3 Orifice plate 4 Orifice (ink ejection hole) 5, 5 'ink 6 Film bubble 7 Ink droplet 10 Ink ejection head 11 Chip substrate 12 Drive circuit 13 Resistance heating part 14 Individual wiring electrode 15 Common electrode 16, 17 (17a, 17b) Partition wall 18 Orifice plate 19 Discharge nozzle (orifice) 21 Small chamber 22 Ink flow path 23 Ink supply groove 24 Ink supply hole 31 Chip substrate 32 Common electrode 33 Common electrode power supply terminal 34 Individual wiring electrode 35 Heating resistor 36 Drive circuit 37 Drive circuit terminal 38 (38a, 38b, 38c, 38d) Ink supply path 39 Ink supply hole 40 Seal partition 40-1 Flow path side partition 40-2 Partition partition 41 Partition (small chamber) 42 Ink flow path 43 Orifice plate 44 Ink ejection nozzle (Orif Scan) 45 mono-color printing head 46 opening 47-1,49-1,50-1,51-1,51-
1 ', 51-1 "Flow path side partition 47-2, 49-2, 50-2, 51-2 Partition partition A, B Partition position k1, k2, k3, k4, k5 Partition shape

Claims (5)

[Claims] 1. A plurality of heating elements for generating thermal energy for discharging ink disposed at predetermined positions on a substrate, and individually surrounding the plurality of heating elements around the entire circumference in the horizontal direction. A partition for forming a pressurized chamber for applying pressure to the ink by generating air bubbles by each of the heat generating elements, wherein the heat generating element is provided to face the substrate via the partition. And an orifice plate having an ink discharge nozzle formed at a position corresponding to the above, and a common flow path which is communicated with each of the pressurizing chambers through the opening and feeds ink to be supplied to the pressurizing chamber. Characteristic inkjet print head. 2. The ink jet print head according to claim 1, wherein the opening is formed by removing an end of the partition wall on the side of the orifice plate. 3. The ink jet print head according to claim 1, wherein the opening is formed by removing an end of the partition wall on the substrate side. 4. The ink jet print head according to claim 3, wherein a portion of the partition wall where the opening is provided is provided on the orifice plate. 5. The partition wall surrounds the heating element in a rectangular shape, and the opening is provided on three sides except one side of the partition wall opposite to the common flow path. The ink jet print head according to claim 1, 2, 3, or 4, wherein: