JP3437271B2 - Ink jet head, ink jet head cartridge and ink jet device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head and an ink jet device using the head.

[0002]

2. Description of the Related Art Conventionally known ink jet heads have energy generating means used for ejecting ink to a liquid passage thereof, and ink supplied to a liquid chamber from an ink tank or the like via an ink supply port is described above. The ink is guided to the liquid path, where the energy generated from the energy generating means is applied to the ink, and the ink is ejected from the ejection port. Then, the ejected ink droplets land on the recording material to form pixels and recording is performed.

Among such ink jet heads, an ink jet head for ejecting a recording liquid (ink) by utilizing thermal energy records a high resolution because a plurality of ejection ports can be arranged at a high density. In addition to being possible, it has an advantage that it can be easily made compact as a whole.

A conventional ink jet head utilizing this heat energy achieves a high density by arranging a plurality of heating resistors in a row on a substrate such as silicon, and further, for a plurality of heating resistors. In general, a substrate having a common heat storage layer or an electrically insulating layer is used.

FIG. 11 is a schematic sectional view of an ink jet head as a background art of such a constitution.

In the figure, reference numeral 1 is a substrate made of alumina,
Reference numeral 2a indicates a heat storage layer, and 2b and 2c indicate electric insulation layers, respectively. Reference numeral 3 indicates the heating resistor, reference numeral 3a indicates an electrode wiring for supplying electric power to the heating resistor 3, and reference numeral 4 indicates a cavitation-resistant protective film.

An ink jet head is constructed by joining a top plate 400 having a groove for forming a liquid path 401 and the like on a heater board (hereinafter also referred to as a laminated circuit board) 100 having the above-described structure. To be done.

In such a structure, when the heating resistor is energized for discharging, not all of the heat generated by this is used for discharging, but a part of it is passed to the adjacent liquid passage or the like via the above-mentioned substrate or the like. Is dissipated.

In such a head structure, when ink is ejected from all ejection ports at the same time, that is, when a plurality of heat generating resistors described above are simultaneously heated, the generated heat influences each other and ejects. The volume of the ink droplet becomes relatively large. On the other hand, when the heat generating resistor is solely caused to generate heat, the discharge volume becomes relatively small compared to the above situation. Therefore, when the heating resistor is driven independently, for example, in order to obtain the same discharge amount as in the case of full discharge, it is necessary to generate more heat energy than usual.
That is, since there is a difference in the bubbling efficiency with respect to the input energy, the power supply scale is complicated to adjust the discharge amount between single discharge and full discharge, or the discharge in single discharge is used as the reference for full discharge without adjustment. Insufficient amount will occur and the quality of the recorded image will be significantly degraded.

FIG. 12 is a diagram showing the relationship of the ejection amount Vd with respect to the input power P of the head as described above.

As is apparent from the figure, there is a large difference in the discharge amount between the single discharge and the total discharge, especially in the power _P'TH at which the discharge is started, and the temperature at which the ink causes film boiling occurs. This difference occurs even though the power required to obtain it is equal. This is because there is a difference in heat storage property in the bubbling portion after the heating resistor has generated heat, and when discharged from a single nozzle, the heat radiation to the adjacent liquid passage is large and the maximum bubbling size is sufficient. This is because when the plural heat generating resistors are driven at the same time as in the case of full discharge, the amount of foaming is sufficient because the heat dissipation to the adjacent liquid passages is not so great when the bubbles disappear before they reach the end. .

Namely, in the conventional head, even alone discharge to obtain the same ejection amount as full discharge would require power corresponding to _OP 'larger P than _TH' P as shown in FIG. 12.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the above conventional and background arts, and an object of the present invention is to form a laminated circuit board between adjacent heating resistors. An object of the present invention is to provide an ink jet head and an ink jet device capable of performing stable ejection with a small amount of input energy to obtain a high-quality image by improving the layer structure in consideration of heat conduction of the layer.

[0014]

The main requirement of the present invention for solving such a problem is that an ink jet head in which a plurality of heat generating resistors for ejecting ink are arranged in a row is formed on a substrate. A substrate on which the heating resistor and a plurality of layers for electrical insulation or protection are laminated, and a liquid flow path provided on the substrate corresponding to the heating resistor , A partition that forms part of the member that forms the liquid flow path.
Has a plurality of liquid flow paths respectively by the wall is partitioned, and the partition wall, before the part of the range between the heating resistor adjacent in the sequence of the plurality of heating resistors
It is in contact with the uppermost layer of the substrate and is narrower in the contact area.
A hollow recess is formed by removing all of the plurality of layers in the range .

[0015]

According to the above structure, by adjusting the layer structure of the plurality of layers forming the laminated circuit board in the region forming the boundary of the liquid passage serving as the heat action chamber, the heat generated in the liquid passage is outside the liquid passage. To the outside of the liquid path can be reduced.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a schematic view showing a cross section in the direction of arrangement of electrothermal conversion elements of a laminated circuit board of an ink jet head according to the first embodiment of the present invention.

In the figure, reference numeral 1 is a substrate made of alumina, silicon or the like, reference numeral 2a is a heat storage layer also serving as an electrically insulating layer made of silicon oxide or the like, and 2b and 2c are made of silicon oxide or silicon nitride. Electrical insulating layers for electrically isolating or protecting each of the plurality of heat generating resistors in the vicinity thereof are shown. Reference numeral 3 indicates a heating resistor made of hafnium boride, tantalum nitride, or the like, and aluminum for supplying power to the heating resistor 3 is provided above the heating resistor 3 except for a portion serving as the heating portion. The electrode wiring 3a composed of the above is formed. The heating resistor 3 and the electrode wiring 3a described above constitute an electrothermal conversion element. Reference numeral 4 denotes a cavitation-resistant protective film made of metal such as tantalum. The heater board 100 as a laminated circuit board is configured by arranging the above layers.

An ink jet head is constructed by joining the top plate 400 integrally provided with a plurality of partition walls 400a for forming the liquid passages 401 and the like on the heater board 100 shown above.

In this example, the first insulating layer 2a, which also functions as a heat storage layer, of the layers 100a constituting the layers between the heating resistors.
And a portion between the flow paths of the cavitation-resistant protective layer 4 is longer than the length of the heat generating portion of the heat generating resistor in the flow path direction (only its cross section is shown in FIG. 1) across the array direction of the heat generating resistors. The laminated circuit removed in the direction along the flow path was used as the substrate.

Specifically, the heating portion of the heating resistor 3 (the portion without the electrode wiring 3a) has a width of 40 μm and a length of 10
The thickness is 5 μm and the thickness is 0.05 μm. At this time, the thickness of the first insulating layer 2a is 1.5 μm, and the removal width is 20 μm.
m, and the removal length is 400 μm. Similarly, the thickness of the anti-cavitation film was 0.2 μm, the removal width was 20 μm, and the removal length was 400 μm.

FIG. 2 shows a view of the vicinity of the discharge portion of such a substrate as seen from above. As shown in the drawing, the first insulating layer is formed between the heating resistors by dry etching, wet etching or the like in a direction intersecting the arrangement direction of the heating resistors (in the case of this embodiment, it is orthogonal). By using the method (the concave portion formed by this division method is indicated by reference numeral 5).

When the ink-jet head of this example was mounted on a recording apparatus and recording was performed, high-quality recording results could be obtained even when ejecting independently with low power (about 3.5 W).

FIG. 3 is a diagram showing the discharge amount Vd with respect to the input power P of the ink jet head of this example.

As is clear from the figure, the characteristics are almost the same between the full discharge and the single discharge, and it is understood that the thermal efficiency is much better than that of the conventional ink jet head.

This is because by removing the cavitation resistant layer 4 and the first insulating layer 2a between the adjacent heating resistors, the amount of the heat transfer medium to the adjacent liquid passage is reduced, and as a result, the overall heat transfer amount. Is reduced. As a result, unnecessary heat dissipation is avoided, a sufficient heat storage effect is produced even in single discharge, and stable bubbling and discharge are possible even with a small electric power.

In the present embodiment, the removing portion extends in the direction intersecting the heating resistor layer row between the heating resistors, but the length thereof is the length of the heating resistor centering around the row of heating resistors. Therefore, the length is preferably about twice, and more preferably about 5 times the length of the heating resistor.

Further, in the present embodiment, the head which ejects ink in the direction along the heating resistor has been described, but in the head which ejects ink to the side on which the heating resistor is arranged. The present invention can also be applied.

FIG. 4 is a schematic view showing a cross section of a laminated circuit board showing another embodiment of the present invention.

In this example, in the layer structure similar to that of Example 1, the cavitation-resistant layer 4 and the third insulating layer 2c of the layer 100a between the heating resistors are 20 μm wide and 4 long.
Remove over 00 μm.

When the ink jet head of this embodiment was mounted on a recording apparatus and recording was performed, low power (about 3.5) was obtained.
Even in W), high-quality recording results could be obtained.

Further, when the discharge amount Vd with respect to the input power P was measured, it was revealed that the thermal efficiency was better than that of the conventional ink jet head, as in the first embodiment.

FIG. 5 shows a change in the discharge amount Vd with respect to the drive power P when the head of this embodiment is driven (line A), and line B is a cavitation resistance between heating resistors as a comparison. 20 μm width, 400 μm length
It shows a similar relationship for the ones removed over. Since the anti-cavitation film has a smaller film thickness than other insulating layers, that is, has a small heat capacity, originally, heat conduction toward other heating resistors is not so large. Therefore, even if a part of this film is removed, the effect is not so great. On the other hand, when the insulating layer having a large film thickness and a large heat capacity is removed as in this embodiment and the other embodiments, a large amount of ink can be ejected even with the same power input.

FIG. 6 is a schematic view showing a cross section of a laminated circuit board showing another embodiment of the present invention.

In the layer structure similar to that of the first embodiment, only the first insulating layer 2a of the layer 100a between the heating resistors has the width 2
Remove over 0 μm, 400 μm length.

When the ink-jet head of this embodiment is mounted on a recording apparatus and recording is performed, high-quality recording results can be obtained even at low power (about 3.5 W), which is similar to each of the above-mentioned embodiments. I was able to.

Further, even when the discharge amount Vd with respect to the input power P was measured, it was revealed that the thermal efficiency was better than that of the conventional ink jet head as in the previous embodiments.

FIG. 7 is a diagram for explaining another embodiment of the present invention. In each of the embodiments described above, an example in which one layer in the insulating layer is removed is shown, but if there is no problem of electrical leakage, a part of each layer is removed as in this example. (The removal portion is indicated by reference numeral 5 in the drawing, and the removal length is the same as that in the previous embodiment).

If a plurality of layers are removed to form the recesses as in this embodiment, thermal crosstalk between adjacent nozzles can be prevented more efficiently at the removed portions.

As described above, the number of layers to be removed may be determined according to the degree of limiting the thermal crosstalk between the adjacent nozzles, and any one insulating layer is removed by about ½. By doing so, the effect can be obtained, but it is desirable to completely remove one of the layers.

As the insulating layer to be removed, it is more effective to remove the layer adjacent to the heating resistor.

Next, with reference to FIGS. 8 to 10, a suitable ink jet unit IJU, an ink jet head IJH, an ink jet cartridge IJC, and an ink jet recording apparatus body I to which the present invention is applied or applied.
It is explanatory drawing of JRA. The configuration of each part will be described below with reference to these drawings.

Inkjet cartridge IJ in this example
As can be seen from the perspective view of FIG. 9, C indicates that the ink jet head unit and the ink tank are integrated, and the ink storage ratio is high.
The inkjet cartridge IJC is a disposable type that is fixed and supported by the positioning means and electrical contacts of the carriage mounted on the inkjet recording apparatus main body IJRA and is detachable from the carriage.

The ink jet unit IJU is a bubble jet type unit for recording by using an electrothermal converter that generates thermal energy for causing film boiling to the ink according to an electric signal.

In FIG. 8, reference numeral 100 denotes an electrothermal converter (ejection heater) arranged in a plurality of rows on a Si substrate, and electric wiring such as Al for supplying electric power to the electrothermal converter, which is formed by a film forming technique. It is a heater board (first base body) formed by. Two
Reference numeral 00 is a wiring board for the heater board 100.

Reference numeral 1300 is a groove provided with a partition (groove) for partitioning a plurality of ink flow paths and a common liquid chamber for accommodating ink to supply ink to each ink flow path (liquid flow path). This is a top plate integrally formed with an orifice plate 400 having a plurality of ejection openings corresponding to the respective ink flow paths. Polysulfone resin is preferable as the integral molding material, but other molding resin materials may be used.

Reference numeral 300 denotes a support body made of, for example, a metal, which supports the back surface of the wiring board 200 on a plane and serves as a bottom plate of the ink jet unit. Reference numeral 500 denotes a presser spring which is a pressing member and has an M-shape and presses the common liquid chamber with a light pressure at the center of the M-shape, and a front salient portion 501 forms a part of the liquid passage, preferably an area near the discharge port. Concentrated pressing with linear pressure. Heater board 1
00 and the top plate 1300, the foot of the spring is supported by the support member 30.
By engaging the rear surface side of the support body 300 through the hole of 0 and engaging them in a sandwiched state, the pressing spring 500 and the front slant portion 501 are concentrated and biased to the heater board 100. The top plate 1300 is fixed by pressure.

The ink tank is the cartridge body 100.
0, the ink absorber 900, and the ink absorber 900 are inserted from the side surface of the cartridge body 1000 opposite to the unit IJU attachment surface, and then the lid member 1 for sealing the same.
It is composed of 100 and. 1200 is the unit IJU
Is a supply port for supplying ink to. 140
Reference numeral 1 is an atmosphere communication port provided in the lid member for communicating the inside of the cartridge with the atmosphere.

In this embodiment, the top plate 1300 is made of a resin such as polysulfone, polyether sulfone, polyphenylene oxide, polypropylene, etc., which has excellent ink resistance, and the top plate 1300 and the polyphis plate portion 400 are integrally and simultaneously formed in the mold. It is molded.

As described above, since the integrally molded parts are the ink supply member 600, the top plate / orifice plate integrated, and the ink tank body 1000, not only the assembly accuracy becomes high, but also the quality of mass production is extremely improved. It is valid. Further, since the number of parts can be reduced as compared with the conventional one, excellent desired characteristics can be surely exhibited.

FIG. 10 is an external view of an ink jet recording apparatus IJRA to which the present invention is applied, showing a lead groove 5005 having a helical groove which rotates via driving force transmission gears 5011 and 5009 in association with forward and reverse rotations of a driving motor 5013. Fifty
The carriage HC engaging with 04 is a pin (not shown)
And is reciprocated in the directions of arrows 1 and 1. A paper pressing plate 5002 presses the paper against the platen in the carriage movement direction. Reference numerals 5007 and 5008 denote home position detecting means for confirming the presence of the lever 5006 of the carriage in this area by a photocoupler and switching the rotation direction of the motor 5013. Reference numeral 5016 is a member that supports a cap member 5022 that caps the front surface of the recording head. Reference numeral 5015 is a suction unit that suctions the inside of the cap to perform suction recovery of the recording head through the in-cap opening 5023. 5017 is a cleaning blade.
Reference numeral 019 denotes a member that allows the blade to move in the front-rear direction, and the main body support plate 5018 supports these members. Needless to say, a well-known cleaning blade can be applied to this example instead of this form. Reference numeral 5012 is a lever for starting suction for suction recovery, which moves in accordance with movement of a cam 5020 that engages with the carriage, and the driving force from the driving motor is controlled by known transmission means such as clutch switching. To be done.

The capping, cleaning, and suction recovery are configured so that desired processing can be performed at their corresponding positions by the action of the lead screw 5005 when the carriage comes to the home position side area. Any of these can be applied to this example as long as the desired operation is performed. Each of the above-described configurations is an excellent invention, either alone or in combination, and shows a preferred configuration example for the present invention.

The apparatus has drive signal supply means for driving the ink ejection pressure generating element.

It should be noted that the present invention is provided with a means (for example, an electrothermal converter or a laser beam) for generating heat energy as energy used for ejecting ink, particularly in the ink jet recording system, and The effect is excellent in a recording head and a recording apparatus of a system that causes a change in ink state by energy. This is because such a system can achieve high density recording and high definition recording.

With regard to its typical structure and principle, see, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling is caused on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal in a one-to-one correspondence
It is effective because bubbles can be formed inside. Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable to make this drive signal into a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the liquid (ink) with excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the ejection port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned specifications, US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
The structure using the specification of No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration corresponding to the ejection portion is disclosed in JP-A-59-138461. That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the recording head.

Further, in the case of a full-line type recording head having a length corresponding to the maximum width of the recording medium which can be recorded by the recording apparatus, the influence of the amount of heat radiation and the accumulated heat greatly appears, so that the present invention is particularly effectively applied. be able to. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads or a configuration as one recording head integrally formed.

In addition, even in the case of the serial type as in the above example, the recording head fixed to the main body of the apparatus or the electrical connection to the main body of the apparatus or the ink from the main body of the apparatus by being attached to the main body of the apparatus. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is integrally provided in the recording head itself is used.

Further, as the constitution of the recording apparatus of the present invention, it is preferable to add ejection recovery means for the recording head, preliminary auxiliary means, etc. because the effects of the present invention can be further stabilized. Specifically, heating is performed by using a capping unit, a cleaning unit, a pressure or suction unit for the recording head, an electrothermal converter or a heating element other than this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.

Regarding the type and number of recording heads to be mounted, for example, only one recording head is provided corresponding to a single color ink, or a plurality of inks having different recording colors and densities are supported. A plurality of pieces may be provided. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but it may be either the recording head is integrally formed or a plurality of combinations may be used. The present invention is also extremely effective for an apparatus provided with at least one of full-color recording modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. Or, in the inkjet system, it is common to control the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. Sometimes, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy of the state change of the ink from the solid state to the liquid state, or in order to prevent the evaporation of the ink, it is solidified and heated in the standing state. You may use the ink liquefied by. In any case, by applying thermal energy such as ink that is liquefied by applying thermal energy according to the recording signal and liquid ink is ejected, or that begins to solidify when it reaches the recording medium. The present invention can be applied to the case where an ink having a property of being liquefied for the first time is used.

In addition, as the form of the ink jet recording apparatus of the present invention, besides the one used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function are provided. It may be a form or the like.

The head of the present invention may be incorporated in a textile printing apparatus for recording on cloth.

[0064]

As described above, according to the present invention,
By improving the layer structure in consideration of the heat conduction of the plurality of layers forming the laminated circuit board at the boundary of the liquid passage serving as the heat action chamber, the transfer of heat generated in the liquid passage to the outside of the liquid passage is suppressed. Therefore, the amount of heat transferred to the outside of the liquid path is reduced.

As a result, the thermal efficiency with respect to the input energy is improved, and a stable discharge amount can be obtained with a small input energy even during the single discharge. That is, the power consumption is small, the power capacity is saved, and higher quality recording can be realized.

[Brief description of drawings]

FIG. 1 is a schematic view showing a cross section of an inkjet head according to an embodiment of the present invention.

FIG. 2 is a diagram showing a partial structure of a substrate of the present invention.

FIG. 3 is a diagram showing a relationship between input power and ejection amount in the inkjet head of the present invention.

FIG. 4 is a diagram for explaining another embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between input power and ejection amount in the inkjet head of the present invention.

FIG. 6 is a diagram for explaining another embodiment of the present invention.

FIG. 7 is a diagram for explaining another embodiment of the present invention.

FIG. 8 is an exploded perspective view of the inkjet cartridge of the present invention.

FIG. 9 is an external perspective view of the inkjet cartridge of the present invention.

FIG. 10 is a diagram showing an apparatus equipped with the inkjet head of the present invention.

FIG. 11 is a schematic diagram showing a cross-sectional view of an inkjet head of the background art.

FIG. 12 is a diagram showing the relationship between the input power and the ejection amount in the head of the background art.

[Explanation of symbols]

1 substrate 2a, 2b, 2c Electrical insulation layer or glass heat storage layer 3 Heating resistor 3a electrode wiring 4 Protective film for cavitation resistance 100 heater board 100a Layer between heating resistors 400 top plate 400a partition 401 liquid path

─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hiroshi Sugitani 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Tsuyoshi Orikasa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Masaaki Izumida 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hiroyuki Ishinaga 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-5-131624 (JP, A) JP-A-62-55155 (JP, A) JP-A-5-1777836 (JP, A) JP-A-2-95850 (JP, A) Kaihei 6-166181 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41J 2/05 B41J 2/175

Claims (7)

(57) [Claims] 1. In an ink jet head in which a plurality of heating resistors for ejecting ink are arranged in a row, the heating resistors and a plurality of layers for electrical insulation or protection are provided on a substrate. Laminated substrates and liquid flow paths provided on the substrates corresponding to the heating resistors
The partition wall forming part of the member forming the liquid flow path
Therefore, each partition has a plurality of liquid flow paths, and the partition wall is the uppermost part of the substrate in a partial range between adjacent heating resistors in the array of the plurality of heating resistors.
About the narrower range of the contact area with the upper layer
An inkjet head , wherein hollow layers are formed by removing all of the plurality of layers of the substrate . 2. The ink jet head according to claim 1, wherein the plurality of layers include an insulating layer. 3. The ink jet head according to claim 1, wherein the plurality of layers include a layer having both electrical insulation and heat storage. 4. The part of the area related to the removal is between the adjacent heating resistors and extends in a direction intersecting with the arrangement direction of the heating resistors. The inkjet head according to claim 1. 5. The inkjet head according to claim 4 , wherein the length of the part of the area related to the removal is longer than the length of the heating resistor in a direction intersecting with the arrangement direction. 6. An ink jet head cartridge, comprising: the ink jet head according to claim 1; and an ink tank that holds ink to be supplied to the ink jet head. 7. An ink jet apparatus comprising the ink jet head according to claim 1 and means for conveying a recording medium.