JPH1095121A - Bubble-jet head and bubble-jet apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the reduction of an ink refilling time and high speed recording by making an area in which the supply route breadth of a cross section perpendicular to the ink discharge opening direction from the opening end of an ink branch supply route is gradually narrowed from the opening end toward an ink heating part. SOLUTION: Since an ink refilling time is caused by the radius of curvature of a meniscus and capillary force determined by the surface tension of ink, and the capillary force increases with the reduction of the radius of curvature of the meniscus, the force increases with the reduction of an ink supply passage breadth near a heater part 32ai. A contraction passage part 48a is expanded from a point Pc toward a parallel passage part 46a so that residual bubbles in ink are discharged easily to an ink discharge side without being retained. Besides, since the the passage 48a is expanded gradually toward the passage part 46a, the generation of a vortex which causes the bubbles to remain is to be checked.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bubble jet head which discharges ink to a recording surface by the pressure of bubbles while being opposed to a recording surface of a recording medium, and
It relates to a bubble jet device in which it is used.

[0002]

2. Description of the Related Art In general, a bubble jet head is classified into an edge shooter type and a side shooter type. In the edge shooter type, an ink discharge port is provided for each of a plurality of ink branch supply paths for guiding ink from an ink storage section. It is provided at an end portion which is a downstream portion with respect to a heater portion as an ink heating portion to be used. On the other hand, the side shooter type is provided at a position where an ink discharge port faces a heater section provided for each of the plurality of ink branch supply paths.

In a side shooter type bubble jet head, since the distance between an ink ejection port forming surface portion on which a plurality of ink ejection ports are arranged and a heating surface of a heater portion is relatively short, work of electric energy supplied to the heater portion is performed. Efficiency is improved, and after the side shooter type bubble jet head is left without being activated,
When a recording operation is performed, there is an advantage that a situation in which a volatile component contained in the ink evaporates to increase the viscosity of the ink and no ink droplet is ejected is significantly reduced.

In a side shooter type bubble jet head, as disclosed in Japanese Patent Application Laid-Open No. 1-152068, for example, in order to reduce the vibration of the meniscus at the time of ink ejection and not to hinder the ejection of ink droplets. A heater section is disposed and surrounded in a housing section having one end opening to the ink supply path, and a flow contracting section is provided between the vicinity of the opening of the common ink supply path and the end of each ink supply path (see this publication). Has been proposed.).

Further, in order to use such a side shooter type bubble jet head to discharge ink droplets of relatively small droplets efficiently without scattering, for example, Japanese Patent Laid-Open No. Hei 5-16365 also discloses As shown,
Bubbles heated and expanded by the heating surface of the heater unit communicate with the atmosphere near the ink discharge ports, and ink covering the bubbles and ink near the ink discharge ports are formed continuously without being blocked by the bubbles. What has been proposed.

[0006]

In such a bubble jet head, in order to speed up the printing operation, it is important to shorten the ink refill time which is an important factor for setting the driving frequency. Become.

However, as in the above example, the heater section
In the case where the flow reducing portion is disposed and surrounded in the accommodating portion and is provided between the vicinity of the opening of the common ink supply path and the end of each ink supply path, the flow reducing resistance increases the flow path resistance. There is a fear. Accordingly, there is a limit in shortening the ink refill time. Also, at the time of high-speed recording,
In some cases, residual air bubbles in the ink that adversely affect the ejection speed and ejection direction of the ink droplets stay in the ink supply path due to the contraction portion.

Further, the bubbles heated and expanded by the heating surface of the heater as described above communicate with the atmosphere near the ink discharge ports, and the ink covering the bubbles and the ink near the ink discharge ports form bubbles. When the ink droplets are continuously formed without being interrupted by the ink droplets, a relatively large meniscus is generated after the ink droplets are ejected (after the ink droplets are cut). The effect of the contraction section on time becomes significant.

In consideration of the above points, the present invention provides a bubble jet head which discharges ink to a recording surface by the pressure of bubbles in ink while being opposed to a recording surface of a recording medium, and Is a bubble jet apparatus, in which the refill time of the ink is sufficiently shortened, the recording operation can be speeded up, and the remaining bubbles in the ink are prevented from staying in the ink supply path. It is an object of the present invention to provide a bubble jet head capable of performing a stable ink ejection operation, and a bubble jet apparatus using the same.

[0010]

To achieve the above object, a bubble jet head according to the present invention has an ink supply port at one end and derives ink supplied from an ink reservoir through the ink supply port. A common ink supply path,
An ink branch supply path having an open end communicating with the ink supply port of the common ink supply path and guiding ink supplied to the ink heating section through the open end, and disposed opposite to the ink heating section at a predetermined distance from the ink heating section An ink ejection port forming surface portion having an ink ejection port for ejecting ink droplets formed by heating the ink heating section guided through the ink branch supply path, wherein the ink branch supply path has an opening of the ink branch supply path. It is characterized in that there is a region in which a supply path width in a cross section in a direction orthogonal to a direction from the end to the direction of the ink discharge port gradually narrows from the opening end to the ink heating section.

A bubble jet apparatus using a bubble jet head according to the present invention is disposed to face a recording surface of a recording medium, and a mounting portion to which the bubble jet head according to claim 1 or 4 is selectively mounted. , A driving unit that moves the recording unit along the recording surface of the recording medium, and a recording operation control unit that causes the bubble jet head to perform a recording operation.

[0012]

FIG. 5 schematically shows an essential part of an example of a bubble jet head according to the present invention and a bubble jet apparatus using the same.

In FIG. 5, the bubble jet device comprises:
A transport device 30 provided in the casing 8 along the longitudinal direction and intermittently transporting a paper 28 as a recording medium in a direction indicated by an arrow C shown in FIG.
The recording unit 10 includes a recording unit 10 that is reciprocated substantially in parallel to a direction substantially perpendicular to the conveyance direction of the recording unit 8, and a recording unit movement driving unit 6 as a driving unit that reciprocates the recording unit 10.

The transport device 30 includes a pair of roller units 22a and 22b, which are disposed substantially parallel to each other, a pair of roller units 24a and 24b, these roller units 22a and 22b, and the roller unit 2a.
4a and 24b. Thereby, when the drive unit 20 is activated, the paper 28 is moved in the direction of arrow C shown in FIG.
4a and 24b, and are transported intermittently.

The movement drive unit 6 is provided with pulleys 26a and 26b which are
And a guide shaft 14 arranged substantially parallel to the roller units 22a and 22b to guide the movement of the carriage member 10a of the recording unit 10.
And a motor 18 for driving the belt 16 connected to the carriage member 10a in the recording unit 10 in the forward and reverse directions.

The motor 18 is activated and the belt 16
Is rotated in the direction shown by arrow S in FIG.
0, the carriage member 10a is moved by a predetermined amount in the same direction, and the motor 18 is activated to rotate the belt 16 in the direction opposite to the direction indicated by the arrow S in FIG. The ten carriage members 10a are moved by a predetermined amount in the direction opposite to the direction indicated by the arrow S in FIG. Further, at one end of the moving drive unit 6,
A recovery unit 26 for performing the ejection recovery process of the recording unit 10 is provided at a position to be a poem position of the carriage member 10a so as to face the ink ejection port arrangement of the recording unit 10.

The recording unit 10 includes a bubble jet head 12
Y, 12M, 12C, and 12B are provided for each color, for example, yellow, magenta, cyan, and black. In addition, each bubble jet head 1
Ink tanks for supplying inks of the respective colors to 2Y, 12M, 12C, and 12B are provided detachably with respect to the carriage member 10a of the recording unit 10.

Bubble jet heads 12Y, 12M, 1
Since 2C and 12B have the same structure, only the bubble jet head 12Y will be described, and the description of the other bubble jet heads 12M, 12C and 12B will be omitted.

As shown in FIG. 4, the bubble jet head 12Y has a drive substrate 32 fixed to a sub-ink tank 40 as an ink storage portion and an ink discharge port forming surface portion fixed on the drive substrate 32. An orifice plate member 34 and an electrode plate member 36 electrically connected to the drive board 32 by a wire group 38 are configured. The bubble jet head 12Y is, for example, 1
Since printing is performed at a maximum of 8000 pixels per second, the scanning speed is 338.8 (mm / s).

When the bubble jet head 12Y is mounted on the recording unit 10, the electrode plate member 36
A plurality of electrode portions 36a electrically connected to the 0 electrode portions are arranged.

The orifice plate member 34 has n ink ejection ports 34ai... 3 in the direction indicated by arrow X in FIG.
4an and 34bi... 34bn (i = 1 to
n) are provided in two rows in parallel at a predetermined interval. Also, the ink ejection ports 34ai... 34a
n and the ink ejection ports 34bi... 34bn are opposed to each other, for example, by 84.7 / 2 μm, and are disposed at the center between two adjacent two ink ejection ports. That is,
The ink discharge ports are arranged in a zigzag pattern with each other. The shape of each ink ejection port 34ai and 34bi is, for example, a short side (20 μm) and a long side (21 μm) along the scanning direction.
.

The drive substrate 32 is made of, for example, silicon, and as shown in FIGS. 2 and 3, an ink supply port 32a that opens in a tapered shape inside the sub ink tank 40.
, 34an and n ink discharge ports 3 in the orifice plate member 34.
4bi... 34bn, the ink ejection port 3
4ai... 34an are extended along the arrangement. The ink supply port 32a is formed by, for example, anisotropic etching. Further, a protective film 32f made of, for example, silicon nitride (SiN) is formed on the entire surface of the drive substrate 32 to which the orifice plate member 34 is fixed. The protective film 32f has, for example, a thickness of 0.6 μm.
m.

As shown in FIG. 2, a heater section 3 is provided on the surface of the drive substrate 32 covered with the protective film 32f.
2ai to 32an and 32bi to bn (i = 1 to
n) are positions opposed to the n ink ejection ports 34ai... 34an and the n ink ejection ports 34bi... 34bn in the orifice plate member 34 at a predetermined pitch interval, for example, at an interval of 84.7 μm. In each, it is arranged. Moreover, each heater part 32ai-32a
n and 32bi to bn have ink supply ports 32a
The ink supplied through the respective heaters 32a
Ink branch supply paths 42ai to 42an and 42bi to 42 leading to i to 32an and 32bi to bn, respectively.
bn are provided symmetrically opposite each other with the ink supply port 32a interposed therebetween.

The ink branch supply paths 42ai to 42an and 42bi to 42bn have the same structure, respectively, so that one of the ink branch supply paths 42ai to 42an and 42bi to 42bn has the same structure. And the description of the other ink branch supply paths will be omitted.

The ink branch supply path 42ai is formed between a pair of partition walls 44a separating the ink branch supply paths, as shown in FIG. The ink branch supply path 42ai includes a parallel passage portion 46a having an open end opening toward the ink supply port 32a at one end, and a parallel passage portion 4a.
6a.
The other end of the ink branch supply path 42ai is provided with a heater 32a.
The accommodation room 50 which accommodates i is provided.

The width dimension Wa of the parallel passage portion 46a in the ink branch supply passage 42ai is, for example, 72 (μm). The contraction passage portion 48a is formed by connecting two contraction portions 48ac and 48ad having different gradients at a point Pc, and one end of the contraction portion 48ac is connected to the parallel passage portion 4a.
6a, and the other end of the contraction portion 48ad is connected to the housing portion 50.

The parallel passage portion 46a in the contraction portion 48ac
Lb from the end to the point Pc and the gradient αc
Is, for example, 20 (μm), about 16.7 degrees [tan
^-1 (6/20)]. The length Lc from the point Pc to the end of the contracted portion 48ad and the gradient αd
Is, for example, 14 (μm), about 29.7 [tan
^-1 (8.0 / 14)]. It is desirable that the gradient at the contraction portion 48ad is set in a range from about 10 degrees to about 30 degrees.

The refill time of the ink is caused by the capillary force determined by the radius of curvature of the meniscus and the surface tension of the ink. Since the capillary force increases as the radius of curvature of the meniscus decreases, the refill time increases in the vicinity of the heater portion 32ai. The capillary force increases as the width of the ink supply passage decreases.

As described above, the reason why the contraction passage portion 48a expands from the point Pc toward the parallel passage portion 46a is as follows.
This is to allow the residual bubbles in the ink to be easily discharged to the ink ejection port side without staying. Further, since the contraction passage portion 48a gradually expands toward the parallel passage portion 46a, the generation of vortices that cause residual bubbles is suppressed.

Further, in order to reliably prevent the residual air bubbles in the ink from staying, the point Pc, the boundary between the contracted portion 48a and the parallel passage portion 46a, and the contracted portion 48a
A predetermined roundness (arc portion) may be formed at the boundary between the and the housing portion 50, respectively.

The heater section 32ai is formed in a rectangular shape having predetermined short sides and long sides. The dimensions Le and Wc of the short side and the long side are, for example, 26 and 36 (μ, respectively).
m). The heater portion 32ai has a distance La from a center position of the ink ejection orifice 34ai substantially coincident with a center position of the ink ejection port 34ai and a distance La from an opening end of the ink branch supply passage 42ai to one side facing the ink branch supply passage 42ai. For example, it is arranged in the accommodating part 50 so as to be 100 (μm).

The housing portion 50 is formed by a wall portion surrounding three sides of the heater portion 32ai at predetermined intervals. The distance Lf between each side of the heater portion 32ai and the wall surface portion,
Wd and We are respectively 4 (μm) at maximum. The distance Ld between the end of the contraction portion 48a and one side of the heater portion 32ai is 4 (μm).

When the bubble Ba is expanded due to the film boiling phenomenon in the ink near the heater portion 32ai, the housing portion 50 is formed by the wall portions surrounding the three sides of the heater portion 32ai at predetermined intervals. At the time of ink ejection, vibration of the orifice plate member 34 is avoided.

In addition, although not shown, an example of the bubble jet apparatus according to the present invention includes a recording operation control unit for controlling the recording operation of the bubble jet head. The recording operation control unit performs predetermined image processing on recording data representing an image to be recorded on the paper 28, forms a drive control pulse signal based on the binarized data, and generates the driving control pulse signal at a predetermined timing. Supply to the bubble jet head.

With this configuration, the ink supply port 32a
When the recording unit 10 is moved in the scanning direction while the ink is supplied to the storage unit 50 at a predetermined amount and at a predetermined timing through the ink branch supply path 42ai, a drive control pulse signal from the recording operation control unit is output. Each heater section 3
When the ink is supplied to the ink 2ai, the bubble Ba is expanded due to the film boiling phenomenon in the ink near the heater 32ai, and the ink is pushed up to the ink ejection port 34ai side. At this time, the bubble Ba is brought into communication with the atmosphere from the outside air side peripheral portion of the ink ejection port 34ai to the vicinity of the inside ejection port At, and a portion of the ink droplet Do other than the vicinity of the inside ejection port At is ink. An experiment by the inventor of the present application confirmed that the ink was connected to the ink in the branch supply path 42ai. As a result, stable ejection can be achieved without generating small droplets.
8 is performed on the surface.

When the pulse width of the drive control pulse signal and the drive voltage are 2.5 (μs) and 13 V, the ink ejection volume, the ink flying speed, and the refill time (the drive control pulse signal (Period from the start of application to the section 32ai to the completion of ink refilling)
^Are 8.4 × 10 ⁻⁹ (cm ³ ) and 15.9, respectively.
(M / s) and 95 (μs) were confirmed by experiments by the inventor of the present application. The ink used in the experiment has the following components.

Thiodiglycol 5% Glycerin 5% Urea 5% Isopropyl alcohol 4% Acetylenol solution 0.1% Water balance On the other hand, FIG. 6 shows a comparative example. In FIG. 6, one of the ink branch supply paths 52 and the accommodating portion 56, which are arranged in a zigzag pattern symmetrically with respect to the ink supply port 32a, is shown in an enlarged manner. Note that the heater section 32ai, the orifice plate 34, and the sub ink tank 40 are the same as those in the above-described example.

The ink branch supply path 52 is formed by partition walls 48a which are arranged substantially parallel to each other and opposed to each other at a predetermined distance Wa, for example, at a distance of 72 (μm). Heater section 3
The storage chamber 56 for storing 2ai communicates with the ink branch supply path 52 via the contraction portion 58.

The housing section 56 is provided with, for example, a heater section 32ai.
Is formed by a wall portion surrounding the three sides.
The length Lh of the wall surface along the short side of the heater portion 32ai in the housing portion 56 and the length Wc along the long side thereof are 34 and 44 μm, respectively.

The heater section 32ai is located at a predetermined distance Wha, Whb, Lha, Lhb,
For example, each of them is arranged at a distance of 4 (μm). Further, the position of one side of the heater section 32ai facing the ink branch supply path is a predetermined distance La from the opening end of the ink branch supply path 52, for example, 100 (μm).
They are separated from each other.

The contraction part 58 is provided on the slope part 5 facing the accommodation part 56.
4a, and a parallel passage portion 54b having a diameter Wn smaller than the inner diameter of the ink branch supply passage 52.

The slope 54a has a predetermined gradient tan ^-1 (W
ta / Ltb), for example, tan ^-1 (7/6). Also, a step Wtb between the slope portion 54a and the storage / accommodation portion 56.
Is 6.5 (μm). The diameter Wn and the length Lta of the parallel portion 54b are, for example, 17, and
8 (μm).

With this configuration, the pulse width of the drive control pulse signal and the drive voltage are set to 2.
At 5 (μs) and 13 (v), the ink ejection volume, the ink flying speed, and the refill time are respectively
8.4 × 10 ⁻⁹ (cm ³ ), 16.6 (m / s), 14
0 (μs) was confirmed by an experiment by the inventor of the present application. Therefore, in the comparative example, it was confirmed that the refill time was longer than in the above-described example according to the present invention.

FIG. 7 shows another example of the bubble jet head according to the present invention.

In FIG. 7, in the example shown in FIG. 1, each of the ink branch supply paths 42ai to 42an is
a and a contraction passage portion 48a, and the ink is supplied to the accommodating portion 50 accommodating the heater portion 32ai through the ink branch supply passage 42ai. Instead, the ink supply port 32a is interposed therebetween. Ink branch supply paths 60ai to 60an provided symmetrically, and
60bi to 60bn (i = 1 to n) are composed of parallel passages, and the accommodation chamber 64 for accommodating the heater 32ai, which is the same as in the above example, expands and communicates toward the end of the parallel passage. Things.

In FIG. 7, the ink branch supply path 60a
i to 60an and one of the housing portions 64 are shown in an enlarged manner.

The ink branch supply path 60ai is formed by partition walls 66a which are arranged substantially parallel to each other and oppose each other, and separate adjacent ink branch supply paths. The width Wa of the width of the parallel passage portion in the ink branch supply passage 60ai is, for example, 72 (μm).

The storage section 64 is provided with an ink branch supply path 60ai.
Are formed so as to be surrounded by a tapered wall surface portion 64a connected to the parallel passage portion and a wall surface portion 64b opposed to the opening end of the parallel passage portion of the ink branch supply passage 60ai. The wall portion 64a has a predetermined gradient [tan ^-1 ] with respect to the parallel passage portion.
(14/68)], and a predetermined length Lr, for example,
68 (μm), and one end is connected by a wall surface portion 64b. The width dimension Wb of the wall portion 64b is, for example, 4
4 (μm).

In the housing portion 64, a heater portion 32ai is arranged at a substantially central position separated from the wall surface portion 64b by a predetermined length Lf, for example, 4 (μm). Also, the heater unit 3
The position of one side facing the ink branch supply path 60ai in 2ai is a predetermined distance L from the open end of the parallel passage section.
a, for example, at positions separated by 100 (μm).

Under this configuration, the pulse width of the drive control pulse signal and the drive voltage are set to 2.
In the case of 5 (μs) and 13 (v), the ink ejection volume, the ink flying speed, and the refill time (from when the drive control pulse signal is started to be applied to the heater unit 32ai to when the ink refilling is completed) Period) is 8.
3 × 10 ⁻⁹ (cm ³ ), 15.6 (m / s), 88 (μ
s) was confirmed by experiments by the inventor of the present application.

Therefore, also in this embodiment, the refill time is shortened as compared with the comparative example as in the above-described example, and the same operation and effect as in the above-described example can be obtained.

[0052]

As is apparent from the above description, according to the bubble jet head and the bubble jet apparatus using the same according to the present invention, the ink branch supply path is formed by discharging ink from the opening end of the ink branch supply path. Since the supply path width in the cross section in a direction orthogonal to the direction toward the outlet has a region gradually narrowing from the opening end toward the ink heating unit, the capillary force of the ink is increased near the ink heating unit, and the ink is increased. The refill time can be shortened sufficiently to increase the speed of the recording operation, and a stable ink ejection operation can be performed by preventing the residual air bubbles in the ink from staying in the ink supply path.

In the case where the ink heating section is surrounded by the wall section of the accommodating section formed so as to be continuous with the wall section forming the peripheral section of the ink branch supply path, the ink ejection port due to bubbles generated in the ink. The vibration of the forming surface can be suppressed.

Further, when the bubbles formed inside the ink by the heating by the ink heating section are in an expanded state, the bubbles are communicated with the atmosphere near the ink discharge port, and the ink covering the bubble is transferred to the ink near the ink discharge port. Since the ink droplets are connected, there is an advantage that when the ink is ejected, the ejection amount and the ejection speed can be stabilized without causing the ink to be splashed in the vicinity of the ink ejection port.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view showing a main part of an example of a bubble jet head according to the present invention.

FIG. 2 is an enlarged cross-sectional view showing a main part of an example of a bubble jet head according to the present invention.

FIG. 3 is a sectional view taken along the line III-III in the example shown in FIG. 2;

FIG. 4 is an enlarged perspective view showing a main part of an example of a bubble jet head according to the present invention.

FIG. 5 is a perspective view schematically showing a main part of a bubble jet device using the bubble jet head according to the present invention.

FIG. 6 is an enlarged cross-sectional view showing a main part of an ink branch supply path of a drive substrate in a comparative example.

FIG. 7 is an enlarged sectional view showing a main part of another example of the bubble jet head according to the present invention.

[Explanation of symbols]

12 Bubble jet head 32 Drive board 32a Ink supply port 32ai-32an, 32bi-32bn Heater unit 34 Orifice plate 34ai-34an, 34bi-34bn Ink ejection port 40 Sub ink tank 42ai-42an, 42bi-42bn Ink branch supply path 60ai- 42an, 60bi to 42bn Ink branch supply path 50, 64 Storage section

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mineo Kaneko 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (9)

[Claims] 1. An ink supply path having an ink supply port at one end for drawing out ink supplied from an ink reservoir through the ink supply port, and an opening communicating with the ink supply port of the ink supply path. An ink branch supply path that has an end and guides the ink supplied through the open end to the ink heating section, and is disposed to face the ink heating section at a predetermined distance, and is guided through the ink branch supply path. An ink ejection port forming surface portion having an ink ejection port for ejecting an ink droplet formed by heating the ink heating section, wherein the ink branch supply path extends from an opening end of the ink branch supply path to the ink discharge port. The width of the supply path in a cross section in a direction orthogonal to the direction toward the direction has a region gradually narrowing from the opening end toward the ink heating unit. Bull jet head. 2. A bubble jet head according to claim 1, wherein said ink branch supply path comprises a parallel passage section and a contraction passage section. 3. The ink heating unit according to claim 1, wherein the ink heating unit is surrounded by a wall surface of an ink heating unit accommodating unit formed to be continuous with a wall surface forming a peripheral edge of the ink branch supply path. Bubble jet head. 4. An ink common supply path having an ink supply port at one end for drawing out ink supplied from the ink storage section through the ink supply port, and an opening communicating with the ink supply port of the ink common supply path. An ink branch supply path for guiding ink supplied through the opening end to a storage section having an end and having an ink heating section disposed therein, the ink branch supply path being opposed to the ink heating section at a predetermined distance, and An ink discharge port forming surface portion having an ink discharge port for discharging ink droplets formed by heating the ink heating section guided through a supply path, wherein a distance between opposed wall surfaces of the storage section is equal to or smaller than the ink discharge port. A bubble jet head having a cross section along a radial direction, which becomes shorter from the opening end to the ink heating section. 5. A bubble jet head according to claim 4, wherein said ink branch supply passage is a parallel passage portion. 6. The bubble jet head according to claim 4, wherein said ink heating section is surrounded by a wall portion forming said storage section. 7. The bubble jet head according to claim 1, wherein a plurality of the ink branch supply paths are arranged and arranged with the ink supply port of the common ink supply path interposed therebetween. 8. When an air bubble formed inside the ink by heating by the ink heating unit is in an expanded state, the air bubble communicates with the atmosphere in the vicinity of the ink ejection port, and the ink covering the air bubble is ejected by the ink ejection unit. The bubble jet head according to claim 1, wherein the ink is connected to the ink near the outlet. 9. A recording section, which is disposed to face a recording surface of a recording medium and has a mounted portion to which the bubble jet head according to claim 1 is selectively mounted, A bubble jet apparatus comprising: a driving unit that moves along a recording surface; and a recording operation control unit that causes the bubble jet head to perform a recording operation.