JP5793850B2 - Liquid ejecting head and liquid ejecting apparatus - Google Patents

Description

The present invention relates to a liquid ejecting head and a liquid ejecting apparatus that eject droplets from nozzle openings, and more particularly to an ink jet recording head and an ink jet recording apparatus that eject ink as liquid.

An ink jet recording head which is an example of a liquid ejecting head has been proposed in which two or more nozzle openings are provided for one pressure generating chamber (see, for example, Patent Document 1).

According to such an ink jet recording head, the resolution of the printed material can be increased, and the optical density (OD value; Optical Density) of the printed material can be increased.

JP 2002-331658 A

However, if ink droplets are ejected simultaneously from the two nozzle openings, the two ink droplets will fly away in the direction away from each other due to the influence of airflow and electrostatic force (Coulomb force) during flight,
There is a problem that the landing position is shifted and print quality is deteriorated.

Such a problem exists not only in an ink jet recording head but also in a liquid ejecting head that ejects liquid other than ink.

In view of such circumstances, the present invention can improve the printing quality by causing the liquid droplets ejected from the nozzle openings to fly straight, thereby improving the printing quality, and increasing the resolution of the printed material. It is an object of the present invention to provide a liquid ejecting head and a liquid ejecting apparatus capable of improving the above.

An aspect of the present invention that solves the above problems includes a nozzle plate in which a nozzle opening for ejecting a liquid is formed , a pressure generation chamber that communicates with the nozzle opening, and a pressure change in the pressure generation chamber to generate the nozzle opening. comprising a pressure generating means for discharging liquid droplets, from, one of the which the nozzle openings of the multiple is provided to the pressure generating chamber, a plurality of the nozzle openings communicating with one of said pressure generating chamber Is arranged at a position where the distance from each nozzle opening to the nearest wall of the flow channel immediately before the nozzle opening is different, and the wall is a side surface of a recess formed on the pressure generating chamber side of the nozzle plate The liquid ejecting head is characterized in that.
In this aspect, the flow resistance of the flow path immediately before each nozzle opening can be changed by setting the distance to the wall of each nozzle opening to be a different distance. Thereby, the flow velocity of the liquid discharged to each nozzle opening can be changed, and the flying speed of the droplet discharged from each nozzle opening can be changed. Therefore, it is possible to suppress the droplets ejected from the nozzle openings from flying at the same height, and to suppress the flight bend due to the influence of the air current, electrostatic force, or the like.

Here, it is preferable that two nozzle openings are provided for one pressure generation chamber. According to this, by providing three or more nozzle openings with respect to one pressure generating chamber, it is possible to suppress a decrease in liquid discharge characteristics due to an increase in flow path resistance.

Preferably, the nozzle opening is formed in the nozzle plate, and the wall is a wall of a liquid channel formed in a channel member fixed to the pressure generating chamber side of the nozzle plate. According to this, since the distance from each nozzle opening to the nearest wall can be set to a different distance only by changing the positions of the plurality of nozzle openings with respect to the partition wall of the flow path, there are few structural changes. Cost can be reduced.

In addition, the nozzle opening is formed in the nozzle plate, and the nozzle plate has a recess formed on the pressure generation chamber side, and the wall is a side surface of the recess. It is preferable that According to this, it is not necessary to change the joining position between the nozzle plate and the flow path member simply by providing a recess in the nozzle plate, and positioning can be performed easily.

Moreover, it is preferable that a plurality of the nozzle openings provided for one pressure generation chamber are provided side by side in the direction in which the pressure generation chambers are arranged. According to this, the resolution can be improved by arranging the nozzle openings in the juxtaposition direction of the pressure generating chambers.

Moreover, it is preferable that the nearest wall of the flow path immediately before the nozzle opening is a wall on both sides in the juxtaposition direction of the plurality of nozzle openings. According to this, it is possible to make the droplets fly straight without the landing position being shifted in a direction orthogonal to the direction in which the pressure generating chambers are arranged side by side.

Further, according to another aspect of the present invention, there is provided a nozzle plate in which a nozzle opening for ejecting liquid is formed , a pressure generation chamber communicating with the nozzle opening, a pressure change in the pressure generation chamber, and a change in pressure from the nozzle opening. comprising a pressure generating means for discharging liquid droplets, and with respect to one of said pressure generating chamber is provided with the nozzle openings of the multiple, the plurality of nozzle openings communicating with one of said pressure generating chamber The flow path resistance of the flow path immediately before each nozzle opening is arranged at a position where the flow path resistances are different from each other, and the flow path resistance is a side surface of a recess formed on the pressure generating chamber side of the nozzle plate. In the liquid ejecting head, the flow path resistance is
In this mode, the flow velocity of the liquid flowing through each nozzle opening is changed by changing the flow resistance of the flow path immediately before each nozzle opening, and the flying speed of the liquid droplets discharged from each nozzle opening is changed. be able to. Therefore, it is possible to suppress the droplets ejected from the nozzle openings from flying at the same height, and to suppress the flight bend due to the influence of the air current, electrostatic force, or the like.

According to another aspect of the invention, there is provided a liquid ejecting apparatus including the liquid ejecting head according to the above aspect.
In this aspect, a liquid ejecting apparatus with improved print quality can be realized.

FIG. 3 is an exploded perspective view of the recording head according to the first embodiment. FIG. 3 is a plan view of the recording head according to the first embodiment. FIG. 3 is a cross-sectional view of the recording head according to the first embodiment. FIG. 3 is an enlarged cross-sectional view of a main part of the recording head according to the first embodiment. FIG. 3 is a plan view from the flow path side of the nozzle plate according to the first embodiment. It is sectional drawing to which the principal part which shows a comparative example was expanded. 6 is an image obtained by photographing ink droplets ejected from Embodiment 1 and a comparative example. FIG. 6 is an enlarged cross-sectional view of a main part of a recording head according to a second embodiment. FIG. 6 is a plan view from the flow path side of a nozzle plate according to a second embodiment. It is a top view from the channel side of the nozzle plate which concerns on other embodiment. It is a top view from the channel side of the nozzle plate which concerns on other embodiment. 1 is a diagram illustrating a schematic configuration of a recording apparatus according to an embodiment.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
FIG. 1 is an exploded perspective view of an ink jet recording head that is an example of a liquid jet head according to Embodiment 1 of the present invention, and FIG. 2 is a plan view of the ink jet recording head.
FIG. 3 is a cross-sectional view taken along line AA ′ in FIG. 2.

As shown in the drawing, the ink jet recording head 10 of this embodiment includes an actuator unit 20 and a flow path unit 30 to which the actuator unit 20 is fixed.

The actuator unit 20 includes a piezoelectric actuator 40, a flow path forming substrate 22 in which the pressure generating chamber 21 is formed, a vibration plate 23 provided on one surface side of the flow path forming substrate 22,
And a pressure generation chamber bottom plate 24 provided on the other surface side of the flow path forming substrate 22.

The flow path forming substrate 22 is, for example, alumina (Al ₂ O ₃ ) having a thickness of about 150 μm.
Or a ceramic plate such as zirconia (ZrO ₂ ) or a metal plate such as stainless steel.

In the present embodiment, the flow path forming substrate 22 is formed with two rows in which a plurality of pressure generating chambers 21 are arranged in parallel along the width direction. A vibration plate 23 made of a thin plate such as zirconia having a thickness of 10 μm is fixed to one surface of the flow path forming substrate 22, and one surface of the pressure generating chamber 21 is sealed by the vibration plate 23. .

The pressure generation chamber bottom plate 24 is a plate-like member that is fixed to the other surface side of the flow path forming substrate 22 and seals the other surface of the pressure generation chamber 21. Further, the pressure generation chamber bottom plate 24 is provided in the vicinity of one end portion in the longitudinal direction of the pressure generation chamber 21, a supply communication hole 25 that communicates the pressure generation chamber 21 and a manifold described later, and the longitudinal direction of the pressure generation chamber 21. A nozzle communication hole provided in the vicinity of the other end and communicating with a nozzle opening described later.

The piezoelectric actuator 40 is provided in each of the regions facing the pressure generation chambers 21 on the vibration plate 23. For example, in this embodiment, two rows of the pressure generation chambers 21 are provided. There are also two rows.

Here, as shown in FIG. 3, each piezoelectric actuator 40 includes a lower electrode film 43 provided on the diaphragm 23, a piezoelectric layer 44 provided independently for each pressure generation chamber 21, The upper electrode film 45 is provided on the piezoelectric layer 44. The piezoelectric layer 44 is formed by attaching or printing a green sheet made of a piezoelectric material. Further, the lower electrode film 43 is provided over the piezoelectric layers 44 arranged side by side and serves as a common electrode for each piezoelectric actuator 40 and functions as a part of the diaphragm. Of course, the lower electrode film 43 is formed on each piezoelectric layer 44.
You may make it provide for every.

In addition, a terminal portion 46 that conducts to the piezoelectric actuator 40 is provided in a region opposite to the peripheral wall of the pressure generating chamber 21 at one longitudinal end of each piezoelectric actuator 40. The terminal portion 46 is provided for each of the piezoelectric actuators 40 and is electrically connected to the terminal electrode 46 that is electrically connected to the upper electrode film 45 of the piezoelectric actuator 40 and the lower electrode film 43 that is drawn out to both ends of the piezoelectric actuator 40 in the parallel arrangement direction. Terminal portions (not shown) are juxtaposed in the direction in which the piezoelectric actuators 40 are juxtaposed. In the present embodiment, two rows of the terminal portions 46 arranged in parallel between the rows of the piezoelectric actuators 40 arranged in parallel are provided. Such a terminal portion 46 includes a flexible printing circuit (FPC) and a tape carrier package (T
CP) or the like is connected, and a print signal from the outside is supplied to the piezoelectric actuator 40 via the external wiring.

The flow path forming substrate 22, the vibration plate 23, and the pressure generation chamber bottom plate 24, which are each layer of the actuator unit 20, are formed of a clay-like ceramic material, a so-called green sheet, to a predetermined thickness, for example, a pressure generation chamber. After drilling 21 and the like, they are laminated and fired to integrate them without requiring an adhesive. Thereafter, the piezoelectric actuator 40 is formed on the vibration plate 23.

On the other hand, the flow path unit 30 is a manifold forming substrate on which an ink supply port forming substrate 31 joined to the pressure generating chamber bottom plate 24 of the actuator unit 20 and a manifold 32 serving as a common ink chamber of the plurality of pressure generating chambers 21 are formed. 33 and a nozzle plate 35 in which nozzle openings 34 are formed.

The ink supply port forming substrate 31 is made of a zirconia thin plate having a thickness of 150 μm, and is provided with a nozzle communication hole 36 for connecting the nozzle opening 34 and the pressure generating chamber 21. The ink supply port forming substrate 31 has a manifold 32 and a pressure generating chamber 2 together with the supply communication hole 25 described above.
1 is connected to the ink supply port 37. Further, the ink supply port forming substrate 31
Are provided with ink inlets 38 that communicate with the manifolds 32 and supply ink from an external ink tank.

The manifold forming substrate 33 is formed of a plate material having corrosion resistance, such as 150 μm stainless steel, which is suitable for configuring the ink flow path. Further, the manifold forming substrate 33 receives a supply of ink from an external ink tank (not shown) and supplies the ink to the pressure generating chamber 21 and a nozzle communication that connects the pressure generating chamber 21 and the nozzle opening 34. And a hole 39. That is, the ink from the manifold 32 is supplied to the supply communication hole 2.
The ink in the pressure generation chamber 21 is supplied to the pressure generation chamber 21 through the nozzle communication hole 26, the nozzle communication hole 36, and the nozzle communication hole 39 due to the pressure fluctuation in the pressure generation chamber 21. It is ejected as ink droplets.

The nozzle plate 35 is provided with a nozzle opening 34 penetrating through a plate member made of, for example, a metal such as stainless steel or a ceramic such as silicon. The nozzle opening 34
Two or more, one pressure generation chamber 21 in this embodiment, for one pressure generation chamber 21
On the other hand, two nozzle openings 34a and 34b are provided. Here, the nozzle plate 3
The two nozzle openings 34a and 34b provided for one pressure generation chamber 21 will be described in detail with reference to FIGS. 4 is a cross-sectional view taken along line BB ′ of FIG. 3, and FIG. 5 is a plan view from the nozzle communication hole side of the nozzle plate.

As shown in FIGS. 2 and 4, two nozzle openings 34 a communicating with one pressure generation chamber 21.
, 34b are provided side by side in the direction in which the pressure generating chambers 21 are arranged side by side. Further, the two nozzle openings 34 a and 34 b are provided in one pressure generation chamber 21 with the nozzle communication hole 26 and the nozzle communication hole 3.
9 to communicate.

Such two nozzle openings 34a, 34b are the closest walls 39a, 39 of the immediately preceding flow path.
The distances d ₁ and d ₂ to b are arranged to be different distances. Here, the flow path immediately before the nozzle openings 34a and 34b is a flow path that directly communicates with the nozzle communication hole 39 in a flow path upstream of the nozzle openings 34a and 34b. In the present embodiment, the nozzle openings 34a, 34
The channel directly communicating with b is a nozzle communication hole 39 provided in the manifold forming substrate 33. The distance d ₁ from one nozzle opening 34 a to the nearest wall 39 a of the nozzle communication hole 39 is different from the distance d ₂ from the other nozzle opening 34 b to the nearest wall 39 b of the nozzle communication hole 39. Thus, the nozzle openings 34 a and 34 b are arranged with respect to the nozzle communication hole 39. In the present embodiment, the distance _{d 1} between the nozzle openings 34a and the wall 39a has to be larger than the distance _{d 2} between the nozzle opening 34b and the wall 39 b. In this embodiment, the walls 39a and 39b closest to the nozzle openings 34a and 34b referred to here are both sides in the direction in which the nozzle openings 34a and 34b of the nozzle communication hole 39 are juxtaposed (the direction in which the pressure generating chambers 21 are juxtaposed). And the side. In other words, the manifold forming substrate 33 is disposed on the pressure generating chamber 21 of the nozzle plate 35.
The nozzle communication hole 39 corresponds to a liquid channel formed in the channel member (manifold forming substrate 33).

Further, the distance d ₃ between the nozzle opening 34a and the nozzle opening 34b is the desired nozzle opening 3
4 arranged at a density of 4. In the present embodiment, two nozzle openings 34a, 34b a distance _{d 3} of the 600dpi interval, i.e., placed in 42.4Myuemu. The distance _{d 3} between the nozzle openings 34a and the nozzle opening 34b as described above, the desired nozzle opening 34
Because it was located at a density of, d ₃ even if the two nozzle openings 34a, the center of 34b coincides with the center of the nozzle communicating hole 39 becomes the same value. Accordingly, the two nozzle openings 34a, 34b of the present embodiment are offset by a predetermined amount (d ₁ -d ₂ ) from the center of the nozzle communication hole 39, which is the flow path immediately before the center of the two nozzle openings 34a, 34b. It can be said that it is arranged.

From such two nozzle openings 34a and 34b, ink droplets are ejected due to pressure fluctuations in one pressure generating chamber 21 that communicates in common. At this time, the two nozzle openings 34a
, 34b are arranged at different distances from the walls 39a, 39b of the immediately preceding nozzle communication hole 39, the flow path resistances due to the influence of the walls 39a, 39b of the immediately preceding nozzle communication hole 39 are different. That is, the two nozzle openings 34a and 34b change the flow path resistance of the ink supplied to the nozzle openings 34a and 34b by changing the distance to the nearest wall of the previous flow path. The channel resistance is higher when close to the walls 39a and 39b and decreases toward the center of the nozzle communication hole 39. Therefore, in this embodiment, the distance d ₁ between the nozzle opening 34a and the wall 39a.
There is larger than the distance d ₂ between the nozzle opening 34b and the wall 39 b, the flow rate of ink supplied to the nozzle openings 34a near the center of the nozzle communicating hole 39 becomes faster. Conversely, the nozzle communication hole 39
The flow rate of the ink supplied to the nozzle opening 34b close to the wall 39b is slow. This
As shown in FIG. 4, ink droplets X ₁ and X ₂ ejected from the two nozzle openings 34a and 34b.
Difference in the flying speed of the two ink droplets X ₁ and X ₂ ejected from the two nozzle openings 34 a and 34 b fly without being arranged side by side.

Here, as shown in FIG. 6, the two nozzle openings 134a, nearest wall 39a of the nozzle communicating hole 39 of the immediately preceding 134b, if the distance _{d 4} to 39b are arranged so as to have the same distance, two nozzles The two ink droplets X ₃ and X ₄ ejected from the openings 134a and 134b bend and fly in directions away from each other. Thus, one of the causes that the two ink droplets X ₃ and X ₄ bend and fly is considered to be the influence of the airflow. That is, since the flow resistances of the nozzle communication holes 39 immediately before the two nozzle openings 134a and 134b are the same, the flying speeds of the two ink droplets X ₃ and X ₄ are the same, and the two ink droplets X ₃ , X ₄ is flying while adjacent to each other. At this time, since the space between the two ink droplets X ₃ and X ₄ is narrow and it is difficult for gas to enter, the outside of the two ink droplets X ₃ and X ₄ tends to flow gas, so the two ink droplets X ₃
, A vortex is generated only outside of X _{4, and} the two ink droplets X ₃ , X ₄ are pulled in a direction away from each other by the eddy current, so that the two ink droplets X ₃ , X ₄ bend and fly away. It is thought that it will end. Moreover, the cause of the flight bending of ink droplets X _3, X _4, in addition to the influence of the air flow, for example, the influence of the electrostatic force of the two ink droplets X _3, X ₄ (Coulomb force) and the like are also contemplated. As described above, when the two ink droplets X ₃ and X ₄ ejected from the two nozzle openings 134a and 134b fly away from each other, the landing positions on the recording medium such as paper are shifted. The print quality will deteriorate.

Therefore, in the present embodiment, as shown in FIG. 4, the distances d ₁ and d ₂ to the walls 39 a and 39 b adjacent to the nozzle communication hole 39 that is the flow path immediately before the two nozzle openings 34 a and 34 b are changed. The flying speeds of the _two ink droplets X ₁ and X ₂ ejected from the two nozzle openings 34a and 34b were changed. In this way, by changing the two flying speed of ink droplets X _1, X _2, without the two ink droplets X _1, X ₂ are adjacent when flying, each of the ink droplets X ₁
, X ₂ can be caused to flow in a straight line without bending the ink droplets X ₁ and X ₂ by generating eddy currents on both sides of X ₂ . Thereby, the landing position of the ink droplet on the recording medium can be made highly accurate, and the printing quality can be improved. In addition, since the two ink droplets X ₁ and X ₂ do not adjoin when flying, the influence of the Coulomb force acting between the _two ink droplets X ₁ and X ₂ can be reduced.

Here, in the ink jet recording head 10 shown in FIG. 4 described above, the two nozzle openings 34a, 34b to _{d 1} is 29.4Myuemu, arranged so _{d 2} is 8.2 .mu.m, the nozzle openings 34a, 34b Ink droplets X ₁ and X ₂ were ejected from the head and the flight state was photographed.
The result is shown in FIG.

For comparison, in an ink jet recording head shown in FIG. 6, the two nozzle openings 134a, and 134b are arranged so as _{d 4} is 18.8Myuemu, the nozzle openings 134a
, 134b, ink droplets X ₃ and X ₄ were ejected and the flight state was photographed. The result is shown in FIG.

As shown in FIG. 7, the two ink droplets X ₁ and X ₂ ejected from the ink jet recording head 10 shown in FIG. 4 fly straight without being separated from each other because the flight positions are gradually shifted. ing. On the other hand, in the ink jet recording head shown in FIG. 6, the two ink droplets X ₃ and X ₄ gradually bend and fly away in a direction away from each other. As is apparent from this result, by changing the distance to the wall near the flow path immediately before the two nozzle openings 34a and 34b, the flow resistance is changed, and the flying speed is changed, so that the ink droplet X ₁ , X ₂ can be made to fly straight without bending.

In the present embodiment, two nozzle openings 34 a and 34 for one pressure generation chamber 21 are provided.
By providing b, the resolution can be increased and the optical density (OD value; Op) of the printed matter
tical Density) can be increased. Optical density (OD value: Optical Density)
Is the degree of opacity of the translucent medium expressed by log (I ₀ / I) (I ₀ is the intensity of incident light and I is the intensity of reflected light). Thus, the dot formed by ejecting ink droplets from the plurality of nozzle openings 34a and 34b has a higher optical density than the pressure generating chamber.
This is considered to be because ink permeation into the recording medium is reduced because printing is performed with a small ink weight (ink droplet with a small dot diameter) compared to the ink weight when two nozzle openings are provided. Further, the drying property can be improved by reducing the permeation of the ink into the recording medium. Therefore, useless consumption of ink can be suppressed.

In the present embodiment, since the flow path unit 30 is provided with two rows of the pressure generating chambers 21, the nozzle plate 35 is also formed with two rows of nozzle openings 34. Also,
The nozzle plate 35 is bonded to the opposite surface of the flow path forming substrate 22 of the manifold forming substrate 33 to seal one surface of the manifold 32.

Such a flow path unit 30 is formed by fixing the ink supply port forming substrate 31, the manifold forming substrate 33, and the nozzle plate 35 with an adhesive, a heat welding film, or the like. In this embodiment, the manifold forming substrate 33 and the nozzle plate 35 are used.
However, it is also possible to form the flow path unit 30 integrally with the actuator unit 20 by using ceramics, for example.

And such a flow-path unit 30 and the actuator unit 20 are joined and fixed through the adhesive agent and the heat welding film.

In the ink jet recording head 10 having such a configuration, ink is taken into the manifold 32 from the ink cartridge (storage unit) via the ink introduction port 38, and the ink is passed through the liquid flow path from the manifold 32 to the nozzle opening 34. Then, a recording signal from a drive circuit (not shown) is supplied to the piezoelectric actuator 40, whereby each pressure generating chamber 21 is supplied.
By applying a voltage to each piezoelectric actuator 40 corresponding to the above and deforming the diaphragm 23 together with the piezoelectric actuator 40, the pressure in each pressure generating chamber 21 increases, and each nozzle opening 34 (two nozzle openings 34a, 34b). Ink droplets are ejected from.

(Embodiment 2)
FIG. 8 is an enlarged cross-sectional view of a main part of an ink jet recording head showing an example of a liquid jet head according to Embodiment 2 of the present invention. FIG. 9 is a plan view from the nozzle communication hole side of the nozzle plate. is there. In addition, the same code | symbol is attached | subjected to the member similar to Embodiment 1 mentioned above, and the overlapping description is abbreviate | omitted.

As shown in FIGS. 8 and 9, the flow path unit 30A constituting the ink jet recording head 10 of the present embodiment includes an ink supply port forming substrate 31 (not shown), a manifold forming substrate 33, a nozzle plate 35A, Are provided.

The nozzle plate 35A has two nozzle openings 3 for each pressure generating chamber 21 (not shown).
4c and 34d are provided. In the present embodiment, the two nozzle openings 34c and 34d are
The pressure generating chambers 21 (not shown) are provided side by side in the parallel direction. Further, the centers of the two nozzle openings 34 c and 34 d are disposed at substantially the same position as the center of the nozzle communication hole 39.

A recess 60 is provided on the pressure generating chamber 21 side of the nozzle plate 35A. The recess 60 is formed with a predetermined depth without penetrating the nozzle plate 35A, and two nozzle openings 34c and 34d are opened on the bottom surface thereof. The recess 60 is provided independently so as to be discontinuous for each nozzle communication hole 39.

Such a recess 60 is formed by two nozzle openings 34c, 34 from inner side walls 60a, 60b.
The distances d ₅ and d ₆ to d (center) are provided at different positions. That is, in the present embodiment, the recess 60 corresponds to the flow path immediately before the nozzle openings 34c and 34d, and the nozzle opening 34
Walls 60a and 60b of the recess 60 are closest to the nozzle openings 34c and 34d of the recess 60, which is the flow path immediately before c and 34d. The walls 60a and 60b of the recess 60 are
In the present embodiment, the inner side walls on both sides of the nozzle openings 34c and 34d in the juxtaposition direction. That is, in the present embodiment, the recess 60 has two nozzle openings 34c and 34d at the center of the recess 60.
It is arranged at a position offset from the center by a predetermined amount (d ₅ -d ₆ ).

Thus, the recess 60 is provided in the nozzle plate 35A, and the recess 60 is formed in the nozzle opening 34c,
As the flow path just before the 34d, the distance _{d 5} from the wall 60a of the recess 60 to the nozzle openings 34c, by a distance _{d 6} and the different distances from the wall 60b of the recess 60 to the nozzle openings 34d, the nozzle openings 34c , 34d can be made to have different channel resistances. Therefore, since ink droplets can be ejected from the two nozzle openings 34c and 34d at different flying speeds, it is possible to suppress flying bending and improve the landing position accuracy on the recording medium.

(Other embodiments)
As mentioned above, although each embodiment of this invention was described, the basic composition of this invention is not limited to what was mentioned above.

For example, in the first and second embodiments described above, the nozzle openings 34a and 34b and the nozzle openings 34 are used.
c, the nearest wall 39a, 39b and the wall 60a, 60b immediately before 34d are connected to the nozzle opening 34.
Although the walls on both sides of the a, 34b and the nozzle openings 34c, 34d are arranged side by side, the positions of the walls are not particularly limited thereto. Here, other examples will be described. FIG. 10 is a plan view from the nozzle communication hole side of the nozzle plate according to another embodiment.

As shown in FIG. 10, the nozzle openings 34 e and 34 f of the nozzle plate 35 </ b> B are provided side by side in the direction in which the pressure generation chambers 21 (not shown) are arranged. One nozzle opening 34f is arranged at a position shifted in one direction perpendicular to the juxtaposition direction from the other nozzle opening 34e. As a result, the distance d ₇ between the nozzle opening 34e and the wall 39c of the nozzle communication hole 39 closest to the nozzle opening 34e.
When a distance d ₈ of the wall 39c of the nozzle openings 34f and the nearest nozzle communicating hole 39 may be a different distance. That is, in the present embodiment, the nearest wall 39c of the flow path (nozzle communication hole 39) immediately before the nozzle openings 34e and 34f is a wall in a direction orthogonal to the juxtaposed direction of the pressure generating chambers 21 (not shown). . That is, according to the present invention, the nearest wall in which the flow path distances immediately before the nozzle openings 34a to 34f are different may be a wall in any direction. However, FIG.
In the example shown in 0, since the nozzle openings 34e and 34f are not arranged in a straight line in the direction in which the pressure generating chambers 21 are arranged, the landing positions on the recording medium are different from those in the first and second embodiments. become. Therefore, it is necessary to input a print signal in consideration of the landing position.

In the example of the first and second embodiments described above, two nozzle openings 34 (nozzle openings 34a and 34b, nozzle openings 34c and 34d, and nozzle opening 3) are provided for one pressure generating chamber 21.
4e, 34f, etc.) is exemplified, but the number of nozzle openings 34 for one pressure generating chamber 21 may be three or more. Here, an example in which three nozzle openings 34 are provided for one pressure generating chamber 21 is shown in FIG. FIG. 11 is a plan view from the nozzle communicating hole side of the nozzle plate.

As shown in FIG. 11, the nozzle plate 35C has three nozzle openings 34g, 34h,
34i is provided. The nozzle openings 34g, 34h, 34i are provided in a straight line in the direction in which the pressure generation chambers 21 (not shown) are arranged. Also, each nozzle opening 34g, 34h,
34i is a distance d to the nearest walls 39a and 39b of the nozzle communication hole 39 which is the immediately preceding flow path.
₉ , d ₁₀ , and d ₁₁ are arranged at different distances. Specifically, the distance _{d 9} between the wall 39b of the nozzle opening 34g and the nozzle communicating hole 39, the distance _{d 10} between the wall 39a of the nozzle openings 34h and the nozzle communicating hole 39, the nozzle openings 34i and the nozzle communicating hole 39 The relationship between the distance d ₁₁ and the wall 39b is d ₉ > d ₁₀ > d ₁₁ . In addition, it is preferable that the distance between the nozzle openings 34g, 34h, and 34i adjacent to each other is the same.

In this way, by changing the nozzle openings 34g, 34h, the distance _{d 9, d 10, d 11} to the closest wall of the flow path of the immediately preceding 34i (nozzle communicating hole 39), the nozzle openings 34g, 34
Since the flow path resistance immediately before h and 34i is changed, the flying speed of the ink droplets ejected from the nozzle openings 34g, 34h and 34i can be changed to suppress the flying bending of the ink droplets.

Furthermore, in the first embodiment described above, the pressure generating means using the thick film type piezoelectric actuator 40 is exemplified, but the present invention is not particularly limited thereto. For example, the lower electrode, the piezoelectric layer, and the upper electrode are formed and lithography is performed. It is possible to use a thin film type piezoelectric actuator that is sequentially laminated by a method, a longitudinal vibration type piezoelectric actuator that alternately laminates piezoelectric materials and electrode forming materials, and expands and contracts in the axial direction. Also, as a pressure generating means, a heating element is arranged in the pressure generating chamber, and droplets are discharged from the nozzle opening by bubbles generated by the heat generated by the heating element, or static electricity is generated between the diaphragm and the electrode. Thus, a so-called electrostatic actuator that discharges liquid droplets from the nozzle openings by deforming the diaphragm by electrostatic force can be used.

Further, the ink jet recording head 10 of each of these embodiments constitutes a part of a recording head unit including an ink flow path communicating with an ink cartridge or the like, and is mounted on the ink jet recording apparatus. FIG. 12 is a schematic view showing an example of the ink jet recording apparatus.

In the ink jet recording apparatus I shown in FIG. 12, ink jet recording head units 1A and 1B (hereinafter also referred to as head units 1A and 1B) each having a plurality of ink jet recording heads 10 include a cartridge 2A and an ink supply unit. 2B is detachably provided, and the carriage 3 on which the head unit 1A is mounted is provided on a carriage shaft 5 attached to the apparatus main body 4 so as to be freely movable in the axial direction. This recording head unit 1
In A and 1B, for example, a black ink composition and a color ink composition are ejected, respectively.

Then, the driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and a timing belt 7 (not shown), so that the carriage 3 on which the head units 1A and 1B are mounted is moved along the carriage shaft 5. . On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S that is a recording medium such as paper fed by a paper feed roller (not shown) is wound around the platen 8. It is designed to be transported.

In the ink jet recording apparatus I described above, the ink jet recording head 10 (
The head unit 1A, 1B) is mounted on the carriage 3 and moves in the main scanning direction. However, the present invention is not limited to this. For example, the ink jet recording head 10 is fixed and the recording sheet S such as paper is used. The present invention can also be applied to a so-called line type recording apparatus that performs printing only by moving the image in the sub-scanning direction.

Furthermore, the present invention is intended for a wide range of liquid jet heads in general, for example, for manufacturing recording heads such as various ink jet recording heads used in image recording apparatuses such as printers, and color filters such as liquid crystal displays. The present invention can also be applied to a coloring material ejecting head, an organic EL display, an electrode material ejecting head used for forming electrodes such as an FED (field emission display), a bioorganic matter ejecting head used for biochip manufacturing, and the like. Further, although the ink jet recording apparatus I has been described as an example of the liquid ejecting apparatus, the liquid ejecting apparatus using the other liquid ejecting heads described above can also be used.

I ink jet recording apparatus (liquid ejecting apparatus), 10 ink jet recording head (liquid ejecting head), 20 actuator unit, 21 pressure generating chamber, 2
2 flow path forming substrate, 23 vibration plate, 24 pressure generating chamber bottom plate, 30, 30A flow path unit, 31 ink supply port forming substrate, 32 manifold, 33 manifold forming substrate, 34, 34a to 34i nozzle opening, 35, 35A, 35B, 35C Nozzle plate, 39 Nozzle communication hole, 39a, 39b, 39c wall, 40 Piezoelectric actuator, 43 Lower electrode film, 44 Piezoelectric layer, 45 Upper electrode film, 46 Terminal part, 60 Recessed part, 60a, 60b Wall

Claims (6)

A nozzle plate in which nozzle openings for ejecting liquid are formed;
A pressure generating chamber communicating with the nozzle opening;
Pressure generating means for causing a pressure change in the pressure generating chamber and discharging droplets from the nozzle opening,
A plurality of the nozzle apertures which is provided for one of the pressure generating chamber is provided on the bottom surface of the recess provided in the pressure generating chamber side of the nozzle plate, the nearest wall of the recess from the nozzle openings Are arranged at different positions,
Said wall liquid ejecting head, characterized in that a side of the front Ki凹 portion. 2. The liquid jet head according to claim 1, wherein the plurality of nozzle openings provided for one pressure generation chamber are provided side by side in a direction in which the pressure generation chambers are arranged side by side. 3. The liquid jet head according to claim 1, wherein the nearest walls of the recesses of the nozzle openings are walls on both sides of the recesses in the direction in which the pressure generation chambers are arranged in parallel. The liquid ejecting head according to claim 1, wherein the nearest wall in the concave portion of each nozzle opening is a wall orthogonal to a direction in which the plurality of nozzle openings are arranged side by side. A nozzle plate in which nozzle openings for ejecting liquid are formed;
A pressure generating chamber communicating with the nozzle opening;
Pressure generating means for causing a pressure change in the pressure generating chamber and discharging droplets from the nozzle opening,
A plurality of the nozzle apertures which is provided for one of the pressure generating chamber is provided on the bottom surface of the recess provided in the pressure generating chamber side of the nozzle plate, the flow path in said recess of the nozzle openings resistance are arranged in position that different from each other,
A liquid ejecting head wherein the flow path resistance is the channel resistance against the side surface of the front Ki凹 portion.   A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1.