JP2002292862A - Ink head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink head in which ink ejected from a plurality of nozzles provided in one ink chamber can be recorded on a recording medium without touching ink ejected from an adjacent nozzle during flight. SOLUTION: The ink head 10 comprises an ink head module 20 having a plurality of ink chambers 21 along the longitudinal direction thereof, and a nozzle plate 30 providing nozzles 31 and 31' on the side (front side) of each ink chamber facing a recording medium. The nozzle 31 has an opening area larger than that of the nozzle 31' on the side opposite to the side facing the recording medium. According to such a constitution, ink is ejected from the nozzle 31 at a higher flight speed than the ink ejected from the nozzle 31'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink head mounted on an ink jet printer,
In particular, it relates to an ink head provided with a plurality of nozzles for one ink chamber.

[0002]

2. Description of the Related Art Various types of image recording apparatuses are known, but recently, they are relatively inexpensive and small in size.
Ink jet printers employing an ink jet recording system have been widely used. The inkjet printer includes an ink head that ejects ink, a moving mechanism that moves the ink head relative to a recording medium on which an image is recorded, and a conveyance that moves the recording medium relative to the ink head. And a mechanism.

The ink head has an ink head module having a plurality of ink chambers arranged at a predetermined pitch along its own longitudinal direction, and an ink head module on the side of the ink chamber facing the recording medium. A nozzle plate disposed on a surface (front surface).

[0004] The nozzle plate provides nozzles that enable ink to be ejected outward to each of the plurality of ink chambers.

Each of the ink chambers is provided with a known energy generating element, such as a piezo element, for applying a force required for discharging ink to the ink when discharging the ink.
The nozzle is configured to be able to eject ink droplets.

In the above-described ink jet printer, the recording medium is intermittently conveyed by driving the convey mechanism. In the intermittent conveyance, the inkjet printer drives an ink head while the recording medium is stopped, and discharges ink droplets from a plurality of nozzles, thereby forming a desired image on the recording medium. To form.

In recent years, an ink jet printer has been desired to have a higher image recording speed. Methods for increasing the image recording speed include increasing the recording frequency. In order to increase the recording frequency, it is necessary to reduce the amount of ink ejected from the entire ink head.
Therefore, it is necessary to reduce the amount of ink ejected from each nozzle. To reduce the amount of ink ejected from each nozzle, it is effective to reduce the diameter of the nozzle opening. However, when the diameter of the nozzle opening is simply reduced, the area of the ink dot recorded on the recording medium by the ink droplet ejected from each nozzle, that is, the ink droplet ejected from one ink chamber, also decreases. As a result, a desired recording area for each ink dot cannot be achieved. Therefore, as shown in FIG. 10, a plurality of nozzles 1031 and 1031 ′ are provided for each ink chamber 1021 of the ink head module 1020, and two ink droplets 80 and 80 ′ ejected from the same ink chamber 1021.
The high recording frequency can be obtained by making the total area of the two ink dots recorded by the above-described method equal to the area of the ink dots from one ink chamber having only one nozzle described above. While one ink chamber 102
Attempts have been made to make the recording area of the ink dot recorded by No. 1 into a desired area.

In the ink head 1010, the total number of ink droplets to be ejected is increased by increasing the number of nozzles corresponding to the ink chambers, thereby reducing the interval between individual ink chambers and increasing the number of ink chambers without increasing the number of ink chambers. Since a plurality of ink dots corresponding to the number can be recorded, a high-resolution image can be recorded.

[0009]

However, as described above, a plurality of nozzles 10 are provided for each ink chamber 1021.
Ink head 101 provided with 31 and 1031 ′
0 has a possibility that the ink droplet 80 from the nozzle 1031 will come into contact with the ink droplet 80 'ejected from the adjacent nozzle 1031' during the flight before being ejected and coming into contact with the recording medium. The ink droplet 80 is used to generate the ink droplet 8 during the flight.
When the ink droplet 80 comes into contact with 0 ', the ink droplet 80 and the ink droplet 80' are integrated into one ink droplet and then recorded on the recording medium. The ink head 1010 is configured so that the amount of ejected ink droplets is reduced in order to increase the recording frequency. There is a problem that it is difficult to record a desired image without increasing the area. More specifically, if an attempt is made to double the recording area with an ink dot formed by one drop (ink drop), the amount of the ink drop must be doubled or more. That is, there is a disadvantage that the recording area of the ink dot when the two drops are combined into one becomes smaller than the recording area of the two ink dots.

Further, if the ink droplets are integrated during flight as described above, the intended number of ink dots cannot be recorded, and the recorded image becomes a low-resolution low-quality image. There is a problem that it becomes.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide a method in which ink droplets ejected from a plurality of nozzles provided in one ink chamber are ejected from adjacent nozzles. It is an object of the present invention to provide an ink head which can be recorded on a recording medium without coming into contact with an ink droplet during flight.

[0012]

Means for Solving the Problems In order to solve the above problems and achieve the object, an ink head of the present invention is configured as follows.

An ink head according to the present invention is attached to an ink head module having a plurality of ink chambers for discharging ink, and a nozzle for passing ink through each of the ink chambers. A nozzle plate, wherein the ink head module comprises an energy generating element that forms a part of the ink chamber and that supplies ejection energy required for ejection to the ink. The ink droplets ejected from each of the nozzles are different from the ejection timing of the ink droplets ejected from an adjacent nozzle in the ink head formed with a plurality of ink nozzles for each of the ink chambers. It is characterized by being discharged at the discharge timing.

According to the above configuration, the ink droplets ejected from each nozzle are ejected at an ejection timing different from the ejection timing of the ink droplet ejected from the adjacent nozzle. It can be recorded on a recording medium without contacting the ejected ink droplets. Therefore, it is possible to provide an ink head that can have a desired recording area of an ink dot recorded by one ink chamber while having a high recording frequency. Also,
An ink head capable of recording a high-resolution image with a simple structure can be provided.

Further, each of the nozzles may be arranged such that a distance from a center of ejection energy in the ink chamber generated by driving the energy generating element is different from that of an adjacent nozzle.

According to the above configuration, each nozzle is configured so that the distance from the center of the discharge energy is different from that of the adjacent nozzle, so that the pressure wave propagating the discharge energy from the center of the discharge energy is generated by each nozzle. The time to reach the nozzle adjacent to this nozzle differs. Then, an ink droplet is ejected from the nozzle to which the pressure wave has reached first. For this reason, the timing of ejecting ink droplets may be different between each nozzle and an adjacent nozzle.

According to another aspect of the present invention, there is provided an ink head module having a plurality of ink chambers for discharging ink, and a nozzle for passing ink through each of the ink chambers. A nozzle plate attached to the ink head module, wherein the ink head module forms a part of the ink chamber and discharge energy required for discharging the ink. Wherein the nozzles are provided with a plurality of ink heads for each of the ink chambers. Discharge is performed at different discharge speeds.

According to the above configuration, the ink droplets ejected from each nozzle are ejected at an ejection speed different from the ejection speed of the adjacent ink droplets.
It can be recorded on a recording medium without coming into contact with ink droplets ejected from an adjacent nozzle. Therefore, it is possible to provide an ink head that can have a desired recording area of an ink dot recorded by one ink chamber while having a high recording frequency. Further, it is possible to provide an ink head which can record a high-resolution image while having a simple structure.

The nozzle may be formed to have a different opening area from the adjacent nozzle.

With the above configuration, the nozzles are formed with different opening areas from the adjacent nozzles, so that the discharge speed of each nozzle and the adjacent nozzle can be different.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) First, an ink head 10 according to a first embodiment of the present invention will be described with reference to FIG.
Description will be made with reference to (a) and (b). FIG. 1 (a)
FIG. 2 is a perspective view showing an ink head 10 according to the embodiment. FIG. 1B is an enlarged cross-sectional view taken along the line XX of FIG. 1A.

(Construction) The ink head 10 is mounted on a known ink jet printer, and is relatively moved in a main scanning direction and a sub scanning direction with respect to a recording medium on which an image is recorded, and ejects ink. Record the image.

The ink head 10 has an ink head module 20 having a plurality of ink chambers 21 along its own longitudinal direction, and a nozzle (front surface) of each of the ink chambers 21 facing the recording medium. 31 and 31 '.

The ink head module 20 is provided with a plurality of ink chambers 21 at a predetermined pitch along its own longitudinal direction. The ink head module 20 is connected to an ink tank (not shown) in the ink jet printer via a tube (not shown) as a liquid path so that ink can be supplied to each ink chamber 21. Each ink chamber 21 has a side wall 22 formed by a piezoelectric driving element, such as a piezo element, which is a known energy generating element that applies a force required for ejecting ink when ejecting ink. It is configured so that ink can be ejected through the 31, 31 '.

The nozzle plate 30 is formed in a flat plate shape, and has two nozzles 31 and 3 for each ink chamber 21 in order to eject ink in the ink chamber 21 as ink droplets.
1 'is provided.

The nozzle 31 is configured so that the diameter of the opening on the side that comes into contact with the outside air, that is, the front surface, has the dimension indicated by reference numeral a. The diameter is configured to have a dimension indicated by reference numeral c. Similarly, nozzle 31 'is configured such that the diameter of the front opening has a dimension indicated by reference numeral b, and the diameter of the rear opening has a dimension indicated by reference numeral d. . The dimension a and the dimension b are the same dimension (dimension a = dimension b), and the dimension c and dimension d are greater than dimension c (dimension c>
Dimension d). That is, the nozzle 31 is configured such that the opening on the back surface is larger than the nozzle 31 '.

(Operation) The operation of the ink head 10 according to the present embodiment will be described below.

The ink head 10 performs an ink discharging operation so as to discharge ink from nozzles according to a command from a control unit (not shown). The ink head 10 generates a radial pressure wave radiating from one point in the ink chamber by the ink discharging operation, and when the radial pressure wave reaches the nozzles 31 and 31 ′, the nozzles 31 and 31 ′.
It is considered that ink droplets are ejected from. Note that the center where the radial pressure wave is generated is indicated by reference numeral P in FIG.

Radial pressure waves reach the nozzles 31 and 31 'of the ink head 10 of this embodiment at the same time.
However, as shown in the above-described configuration, since the nozzle 31 has a larger opening area on the back surface than the nozzle 31 ′, the energy received from the radial pressure wave reaching the front surface of the nozzle 31 is smaller than the front surface of the nozzle 31 ′. Is greater than the energy received from the radial pressure waves reaching. for that reason,
The nozzle 31 is provided with an ink droplet 8 ejected from the nozzle 31 '.
The ink droplet 80 is ejected at a higher flying speed than 0 '. For this reason, the ink droplets 80, 80 'ejected from the nozzles 31, 31' do not fly in parallel but fly at a distance along the ink ejection direction due to the difference in flight speed. Specifically, the ink droplet 80 'flies such that the ink droplet 80 precedes and follows. The ink drops 80, 80 '
Although it becomes spherical due to its own surface tension during flight, since it is flying at a distance from the two ink droplets 80 and 80 'as described above, there is no contact during flight and two ink droplets The droplets can land individually on the recording medium without being integrated.

Therefore, the ink head 10 according to the present embodiment
Since ink droplets ejected from a plurality of nozzles provided in one ink chamber have a difference in flight speed, they can be recorded on a recording medium without contacting each other during flight.

The ink head 10 according to the present embodiment
Are two nozzles 31, 31 'for each ink chamber 21.
However, the number of nozzles is not limited as long as each nozzle can be configured to have a different opening area on the back surface of an adjacent nozzle. For example,
It is also possible to have a configuration having three nozzles as shown in FIG.

The ink head 10 shown in FIG.
The nozzles 31 'on both side walls 1 have the same shape. However, the nozzle 31 disposed at the center in the direction connecting the side walls 22 of the ink chamber 21 is the nozzle 31 ′.
And the front opening area is the same (dimension a = dimension b),
The opening area on the back surface is formed large (dimension c> dimension d). For this reason, the nozzle 31 has an opening area on the back surface different from that of the nozzle 31 ′ adjacent thereto, and can vary the flying speed of the ejected ink droplet. Therefore, ink droplets ejected from three nozzles provided in one ink chamber 21 can be recorded on a recording medium without coming into contact with ink droplets ejected from adjacent nozzles during flight.

(Second Embodiment) An ink head 10 according to a second embodiment of the present invention will be described below with reference to FIG. In the present embodiment, the same components as those of the ink head 10 according to the above-described first embodiment of the present invention are indicated using the same reference numerals as those of the ink head 10. Detailed description is omitted. FIG. 3 shows an ink head 1 according to the present embodiment.
FIG. 4 is an enlarged sectional view showing 0.

The ink head 10 of the present embodiment is different from the ink head 10 of the first embodiment in the shape of the nozzle 31. The nozzle 31 of the present embodiment has the same opening area on the back surface as the adjacent nozzle 31 (dimension c = dimension d).
However, the opening area of the front surface is formed small (dimension a <dimension b). The nozzle 31 has a larger taper angle than the nozzle 31 '.

The radial pressure waves that have reached the nozzle 31 and the nozzle 31 'at the same time receive energy per unit area from the radial pressure waves that reach the opening on the front surface of the nozzle 31 due to the above-described structure. It is larger than the arriving radial pressure wave. Therefore, the nozzle 31 can discharge the ink droplet 80 having a higher flying speed than the ink droplet 80 'discharged from the nozzle 31'.

Therefore, since the ink droplets ejected from the two nozzles 31 and 31 'provided in one ink chamber 21 have a difference in flight speed, they do not contact each other during flight. It can be recorded on a recording medium.

(Third Embodiment) Hereinafter, an ink head 10 according to a third embodiment of the present invention will be described with reference to FIG. In the present embodiment, the same components as those of the ink head 10 according to the above-described first embodiment of the present invention are indicated using the same reference numerals as those of the ink head 10. Detailed description is omitted. FIG. 4 shows an ink head 1 according to the present embodiment.
FIG. 4 is an enlarged sectional view showing 0.

The ink head 10 of the present embodiment differs from the ink head 10 of the first embodiment in the shape of the nozzle 31. In the ink head 10 of the present embodiment, the nozzle 31 and the nozzle 31 'have the same opening area on the front surface and the same opening area on the back surface. However, the nozzle 3 adjacent to the nozzle 31
1 ′ is formed so as to have a different length along the ink ejection direction.

The nozzle 31 ′ is formed so as to protrude from the front surface of the nozzle plate 30, and has a longer length along the ink protruding direction than the nozzle 31. Accordingly, the energy loss of the radial pressure wave passing through the nozzle 31 ′ is larger than that of the nozzle 31. Therefore, the energy received from the radial pressure wave arriving at the nozzle 31 ′ and the nozzle 31 ′ at the same time is larger than the energy received from the radial pressure wave arriving at the opening at the front of the nozzle 31 ′. Smaller than a wave. Therefore, the nozzle 31 '
Discharges the ink droplet 80 at a lower flying speed than the ink droplet 80 ′ discharged from the nozzle 31.

Accordingly, the ink ejected from the two nozzles 31 and 31 'provided in one ink chamber 21 has a difference in flight speed, so that the ink does not come into contact with each other during the flight and the recording is performed. It can be recorded on a medium.

Further, since the nozzle 31 'of the present embodiment is formed so as to protrude from the flat nozzle plate 30, it is possible to prevent the ink from adhering around the front opening of the nozzle 31' and to discharge the ink. It is possible to improve the straightness of the ink to be performed.

(Fourth Embodiment) An ink head 10 according to a fourth embodiment of the present invention will be described below with reference to FIG. In the present embodiment, the same components as those of the ink head 10 according to the third embodiment of the present invention described above are indicated using the same reference numerals as those of the ink head 10. Detailed description is omitted. FIG. 5 shows an ink head 1 according to the present embodiment.
FIG. 4 is an enlarged sectional view showing 0.

In the ink head 10 according to the present embodiment, the direction in which the nozzle 31 projects is the ink head 1 according to the third embodiment.
Different from 0. Ink head 10 of the present embodiment
The nozzle 31 ′ is formed so as to protrude from the back surface of the nozzle plate 30, and is configured to be longer than the nozzle 31 in the ink protruding direction. This allows
Similarly to the ink head 10 according to the third embodiment, the nozzle 31 ′ can discharge the ink droplet 80 at a lower flying speed than the ink droplet 80 ′ discharged from the nozzle 31.

Therefore, since the ink droplets ejected from the two nozzles 31 and 31 'provided in one ink chamber 21 have a difference in flight speed, they do not contact each other during flight. It can be recorded on a recording medium.

Further, since the nozzle 31 'of the present embodiment is configured to protrude in the rear direction, the front surface can be configured as a flat surface. Therefore, in the maintenance operation of the nozzle, the wiping operation for wiping the ink adhered to the vicinity of the nozzle can be efficiently performed. Further, it is possible to prevent the wiper blade from being damaged.

(Fifth Embodiment) An ink head 10 according to a fifth embodiment of the present invention will be described below with reference to FIG. In the present embodiment, the same components as those of the ink head 10 according to the above-described first embodiment of the present invention are indicated using the same reference numerals as those of the ink head 10. Detailed description is omitted. FIG. 6 shows an ink head 1 according to the present embodiment.
FIG. 4 is an enlarged sectional view showing 0.

The arrangement of the nozzles 31 and the nozzles 31 'of the ink head 10 of the present embodiment is different from that of the ink head 10 of the first embodiment. The nozzle 31 and the nozzle 31 'of the ink head 10 according to the present embodiment have the same shape. However, the nozzle 31 and the nozzle 31 ′ are connected to the energy center of the discharge energy described in the first embodiment, that is, the center P of the radial pressure wave W,
It is arranged so that the distance from is different.

Hereinafter, the radial pressure wave W will be described in detail.

The radial pressure wave W is generated by the ink discharging operation as described in the first embodiment.

The ink discharge operation includes an ink chamber expansion operation, an ink chamber reduction operation, and a reference position return operation. After the ink chamber expansion operation, the ink chamber reduction operation is performed. To perform the reference position return operation.

In the ink chamber expanding operation, the side wall 22 is moved from the reference position before the operation so that the volume of the ink chamber 21 is expanded from the reference volume which is the initial volume before the operation by the command of the control unit. 21 (in the direction indicated by the arrow f in FIG. 6B).

The ink chamber contracting operation is performed by moving the side wall 22 from the state in which the side wall 22 is bent outward from the reference position to the position inward from the reference position (indicated by an arrow g in FIG. 6B). (Indicated direction), and make the volume of the ink chamber smaller than the reference volume. In addition, by this ink chamber reduction operation, each side wall 22 compresses ink, and a compression pressure wave which is a pressure wave heading from each side wall 22 toward the center is generated. Then, the compression pressure waves generated from each side wall 22 are encountered at an encounter point (substantially the geometric center of the ink chamber) which is the first point of the same distance from each side wall 22, and both compression pressure waves are generated. The waves are considered to be combined and become a radial pressure wave W radiating from the point of encounter described above. Then, when the radial pressure wave W reaches the nozzles 31, 31 ', ink droplets are ejected from each of the nozzles 31, 31'.
Therefore, the radial pressure wave W is considered to be ejection energy which is energy contributing to ink ejection, and is set as the center P of the ejection energy.

The nozzle 31 is connected to both side walls 22 of the ink chamber 21.
Are arranged at the center in the direction connecting
It is arranged near the side wall 22. Therefore, the nozzle 3
1 is shorter in distance from the center P of the radial pressure wave W than the nozzle 31 '. Therefore, as shown by arrows j1 and j2 schematically showing the moving distance of the radial pressure wave per unit time shown in FIG. 6, the radial pressure wave W generated by the above-described ink ejection operation is applied to the nozzle 31. It reaches first (pointed out by arrow j1) and ejects ink before nozzle 31 '. In other words, the nozzle 31 is
The ejection timing is earlier than 1 '. At this time, nozzle 3
The radial pressure wave W has not reached 1 ′ (arrow j2).
Pointed out).

With the above configuration, the ink head 10 of the present embodiment can discharge the ink discharged from the two nozzles 31 and 31 ′ provided in one ink chamber 21 at different discharge timings. They can be recorded on a recording medium without contacting each other during flight.

The ink head 10 according to the present embodiment
Are two nozzles 31, 31 'for each ink chamber 21.
However, the number of nozzles is not limited as long as each nozzle can be arranged at a different distance from an adjacent nozzle and the center P. For example,
As shown in FIG. 7, it is also possible to configure so as to have three nozzles.

The ink head 10 shown in FIG.
Nozzles 31 ′ are arranged on both side walls of the ink chamber 1, and the nozzle 31 is arranged at the center of the ink chamber 21 in the direction connecting the side walls 22. The nozzle 31 and the nozzle 31 'have the same shape, but the distance from the center P is different between the nozzle 31 and the nozzle 31' due to the above arrangement. The nozzle 31 has a shorter distance from the center P than the two nozzles 31 '. Therefore, it can be said that each of the nozzles 31 and 31 'is configured so that the distance from the center P to the adjacent nozzle is different. Therefore, the ink head 10 shown in FIG.
First ejects ink from the nozzles 31, and then moves the two nozzles 3 arranged on both side walls of the ink chamber 21.
Discharged from 1 '. Therefore, the ink head 1 in FIG.
0 indicates that the ink ejected from the two nozzles 31 and 31 ′ provided in one ink chamber 21 can be ejected at different ejection timings, so that the ink is recorded on the recording medium without contacting each other during flight. obtain.

The distance from the center P of the radial pressure wave W is considered to be a distance from the approximate center of the ink chamber 21 because the center P is considered to be substantially the center point of the ink chamber. . The center of the ink chamber 21 indicates the geometric center of the ink chamber 21.

Further, the distance from the center P is the same as that of the ink head 10 of the present embodiment when the ink head 10 has a rectangular ink chamber having a rectangular cross section XX.
Can be considered as the distance from the center of the opening on the front side. That is, the distance from the center P is considered to be the distance from the center of the opening on the front surface of the ink head 10 when the side wall 22 is formed parallel to each other and the wall surface orthogonal to the side wall is also formed parallel. I can do it.

(Sixth Embodiment) An ink head 10 according to a sixth embodiment of the present invention will now be described with reference to FIG.
This will be described with reference to FIGS. In the present embodiment, the same components as those of the ink head 10 according to the above-described fifth embodiment of the present invention are indicated using the same reference numerals as those of the ink head 10. Detailed description is omitted. FIG. 8A is a perspective view showing the ink head 10 according to the present embodiment. FIG.
FIG. 9B is an enlarged cross-sectional view taken along the line XX of FIG.

The ink head 10 of the present embodiment differs from the ink head 10 of the fifth embodiment in the configuration of the nozzle plate 30 and the ink head module 20. The ink head 10 of the present embodiment has a nozzle plate provided with nozzles 31 and 31 ′ at equal pitches along its own longitudinal direction, and the ink head module has a cross section taken along a cutting line XX. Are configured to have a trapezoidal shape. In the ink head 10, a nozzle plate 30 is arranged on the slope of the trapezoid.
In other words, the ink head module 20 and the nozzle plate 3 are arranged so that the ink chamber 21 of the ink head module 20 extends non-perpendicularly to the nozzle plate 30.
0 is configured.

According to the above configuration, as shown in FIG. 8 (b), the nozzles 3 and 3 'are arranged on the nozzle plate 30 at the same pitch.
1 and the nozzle 31 ′ may be arranged so that the distance from the center P is different. Therefore, in order to shift the ejection timing from the ink head 10, the nozzle 31 and the nozzle 31 '
In making the distance from the center P different from the position of the nozzle 31, the arrangement of the nozzle 31 and the nozzle 31 'is desired without considering the arrangement of the nozzles 31 and 31' when processing the nozzle plate 30. Can be adjusted to the position. For this reason, although the nozzles 31 and 31 ′ can be easily formed on the nozzle plate 30, the two nozzles 3
Since the inks ejected from the ink jets 1 and 31 ′ can be ejected at different ejection timings, the ink jet recording apparatus can be configured so that the inks can be recorded on the recording medium without contacting each other during flight.

In this embodiment, the nozzle 3
The nozzle plates 1 and 31 ′ are provided at equal pitches on the nozzle plate, but can be adjusted to a desired position by disposing the nozzle plate 30 and the ink head module 20. Is not limited.

Hereinafter, a modified example of the present embodiment will be described.

(Modification) In the present embodiment,
The ink head 10 has a cutting line X shown in FIG.
Although the cross section at −X is configured to have a trapezoidal shape, the ink head 10 according to the modified example of the present embodiment is different from the ink head 10 shown in FIG.
As shown in (a), the section taken along a cutting line YY that is a direction orthogonal to the cutting line XX has a trapezoidal shape. In addition, the ink head 10 includes
The nozzle plate 30 is arranged on the slope of the trapezoid.

With the above-described structure, the nozzles 31 and 31 ′ with respect to the center P are formed after the processing of the nozzles 31 and 31 ′ on the nozzle plate 30, while keeping the volumes of the respective ink chambers 21 the same as in this embodiment. Can be adjusted to a desired position. Therefore, although the nozzles 31 and 31 'can be easily processed with respect to the nozzle plate 30, the inks ejected from the two nozzles 31 and 31' can be ejected at different ejection timings. Can be recorded on a recording medium without touching the recording medium.

In this modification, for the above-described position adjustment, adjacent nozzles of each ink chamber are connected with a line R connecting the centers of the nozzles as shown in FIG. 9B.
However, it is necessary to have an angle with respect to a line Q connecting the side walls 22 of the ink chamber 21. By arranging the nozzles 31 and 31 ′ as described above, the arrangement of the nozzle 31 and the nozzle 31 ′ with respect to the center P can be changed by changing the angle of the slope portion in the direction in which the ink chamber 21 extends with respect to the nozzle plate 30. It can be adjusted to a desired position.

Although some embodiments have been described in detail with reference to the drawings, the present invention is not limited to the above-described embodiments, but may be performed within the scope of the invention. Including all implementations.

In the ink head 10 of each of the above-described embodiments, ink ejected from a plurality of nozzles provided in one ink chamber comes into contact with ink ejected from adjacent nozzles during flight. Without being limited to the above, if they can be recorded on a recording medium, they can be configured in combination. Specifically, both the front and back opening areas of the nozzle 31 can be made different from the nozzle 31 ′, and the shapes of the nozzle 31 and the nozzle 31 ′ can be made different from each other. It is also possible to vary the distance.

In order to explain the ink head 10 of the present invention, in each embodiment, a piezoelectric driving element such as a piezo is used as an ejection energy generating element. However, the present invention is not limited to this. The present invention is also applicable to a head driven by using an electrothermal conversion element such as a heater as a discharge energy generation element.

Further, even when the ejection energy generating element is of the piezoelectric driving element type, the electrodes are stacked on the side walls of the ink chamber and the ink is discharged by driving the side walls as described in each embodiment. Not only the XAAR system, but also a so-called MA that drives the surface facing the nozzle
A CH-JET type piezoelectric driving element can also be applied.

The following can be said about the ink head of the present invention.

(1) An ink head module having a plurality of ink chambers for discharging ink, and a nozzle plate attached to the ink head module for providing nozzles for passing ink to each of the ink chambers Wherein the ink head module includes an energy generating element that forms a part of the ink chamber and that supplies ejection energy required for ejection to the ink. In the ink head formed for each of the ink chambers, the nozzles eject ink droplets ejected from each nozzle at an ejection timing different from the ejection timing of ink droplets ejected from an adjacent nozzle. An ink head characterized in that:

According to the above configuration, the ink droplets ejected from each nozzle are ejected at an ejection timing different from the ejection timing of the ink droplet ejected from the adjacent nozzle. It can be recorded on a recording medium without contacting the ejected ink droplets. Therefore, it is possible to provide an ink head that can have a desired recording area of an ink dot recorded by one ink chamber while having a high recording frequency. Also,
An ink head capable of recording a high-resolution image with a simple structure can be provided.

(2) Each of the nozzles is arranged such that the distance from the center of the ejection energy in the ink chamber generated by driving the energy generating element is different from that of the adjacent nozzle. The ink head according to 1).

According to the above configuration, each nozzle is configured to have a different distance from the center of the discharge energy with respect to the adjacent nozzle, so that the pressure wave propagating the discharge energy from the center of the discharge energy is generated by each nozzle. The time to reach the nozzle adjacent to this nozzle differs. Then, an ink droplet is ejected from the nozzle to which the pressure wave has reached first. For this reason, the timing of ejecting ink droplets may be different between each nozzle and an adjacent nozzle.

(3) The respective nozzles are arranged so as to have different distances from the center of the ink chamber with respect to the adjacent nozzles so that the ink droplets ejected from the adjacent nozzles and the ejection timing are different from each other. The ink head according to (1), wherein:

According to the above configuration, since each nozzle is arranged so as to have a different distance from the center of the ink chamber with respect to the adjacent nozzle, the distance from the center of the ejection energy is made different from that of the adjacent nozzle. The timing at which ink droplets are ejected can be different.

(4) The nozzle plate is provided on the surface of the ink chamber facing the recording medium, and the ink chamber extends non-perpendicularly to the surface of the nozzle plate facing the recording medium. The ink head according to (2) or (3), wherein

According to the above configuration, since the nozzle plate and the ink chamber are connected so as to have a predetermined angle, by changing the angle, the position of the nozzle arranged on the nozzle plate can be adjusted. The distance of the ejection energy from the center may be different from that of the adjacent nozzle.

(5) An ink head module having a plurality of ink chambers for discharging ink, and a nozzle plate attached to the ink head module to provide nozzles for passing ink through each of the ink chambers Wherein the ink head module includes an energy generating element that forms a part of the ink chamber and that supplies ejection energy required for ejection to the ink. The plurality of nozzles are formed for each of the ink chambers, wherein the ink droplets ejected from each nozzle are ejected at an ejection speed different from the ejection speed of an adjacent ink droplet. Ink head.

According to the above configuration, the ink droplets ejected from each nozzle are ejected at an ejection speed different from the ejection speed of the adjacent ink droplets.
It can be recorded on a recording medium without coming into contact with ink droplets ejected from an adjacent nozzle. Therefore, it is possible to provide an ink head that can have a desired recording area of an ink dot recorded by one ink chamber while having a high recording frequency. Further, it is possible to provide an ink head which can record a high-resolution image while having a simple structure.

(6) The ink head according to (5), wherein the nozzle has an opening area different from that of the adjacent nozzle.

According to the above configuration, the nozzles are formed with different opening areas from the adjacent nozzles, so that the discharge speed of each nozzle and the adjacent nozzle can be different.

(7) The ink head according to (6), wherein the opening area of the nozzle is an opening area on a side that comes into contact with outside air.

With the above configuration, each nozzle and the adjacent nozzle have different opening areas on the side that comes into contact with the outside air, so that the discharge speed of each nozzle and the adjacent nozzle can be different.

(8) The ink head according to (7), wherein the opening area of the nozzle is the opening area of the nozzle on the side facing the ink chamber.

With the above configuration, each nozzle and the adjacent nozzle have a different opening area of the nozzle facing the ink chamber, so that the discharge speed of each nozzle and the adjacent nozzle can be different.

(9) The ink head according to (7), wherein the nozzle has a length different from that of the adjacent nozzle in the ink discharge direction.

With the above configuration, each nozzle and the adjacent nozzle have different lengths in the ink discharge direction, so that the discharge speed of each nozzle and the adjacent nozzle can be different.

(10) The ink head according to (9), wherein the nozzle has a height different from that of the adjacent nozzle from the surface of the nozzle plate facing the recording medium.

With the above configuration, each nozzle and the adjacent nozzle have a different height from the surface of the nozzle plate facing the recording medium, so that the ejection speed of each nozzle and the adjacent nozzle can be different.

(11) The ink head according to (9), wherein the nozzle has a height different from that of the adjacent nozzle from a surface of the nozzle plate facing the ink chamber.

According to the above configuration, each nozzle and the adjacent nozzle have different heights from the surface of the nozzle plate facing the ink chamber, so that the ink ejected from each nozzle and the adjacent nozzle are ejected. The flying speed with the ink can be different.

(12) The nozzle opening area on the side facing the ink chamber is S1, and the opening area S on the side contacting the outside air is
In the case of 2, at least one of the plurality of nozzles
The ink head according to (6), wherein one nozzle is formed with a different S2 / S1 ratio from the other nozzles.

With the above configuration, since the ratio of S2 / S1 of at least one nozzle is different, the discharge speed of each nozzle and the adjacent nozzle can be different.

[0097]

According to the present invention, ink discharged from a plurality of nozzles provided in one ink chamber is recorded on a recording medium without coming into contact with ink discharged from adjacent nozzles during flight. The resulting ink head may be provided.

[Brief description of the drawings]

FIG. 1A is a perspective view showing an ink head according to a first embodiment. FIG.
FIG. 3A is an enlarged cross-sectional view taken along a cutting line XX of FIG.

FIG. 2 is an enlarged sectional view showing a modified example of the ink head according to the first embodiment.

FIG. 3 is an enlarged sectional view showing an ink head according to a second embodiment.

FIG. 4 is an enlarged sectional view showing an ink head according to a third embodiment.

FIG. 5 is an enlarged sectional view showing an ink head according to a fourth embodiment.

FIG. 6 is an enlarged sectional view showing an ink head according to a fifth embodiment.

FIG. 7 is an enlarged sectional view showing a modified example of the ink head according to the fifth embodiment.

FIG. 8A is a perspective view showing an ink head according to a sixth embodiment. FIG.
FIG. 3A is an enlarged cross-sectional view taken along a cutting line XX of FIG.

FIG. 9A is a perspective view showing a modification of the ink head according to the sixth embodiment. FIG. 9 (b)
FIG. 10 is an enlarged top view illustrating the arrangement of the nozzles in FIG.

FIG. 10 is an enlarged sectional view showing a conventional ink head.

[Explanation of symbols]

 P Center of radial pressure wave 10 Ink head 20 Ink head module 21 Ink chamber 22 Side wall 30 Nozzle plate 31, 31 'Nozzle 80, 80' Ink droplet

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masanobu Shimizu 2-43-2, Hatagaya, Shibuya-ku, Tokyo F-term in Olympus Optical Co., Ltd. (reference) 2C057 AG03 AG12 AG13 AG16 AG18

Claims (4)

[Claims] An ink head module having a plurality of ink chambers for discharging ink; a nozzle plate attached to the ink head module for providing nozzles for passing ink to each of the ink chambers; Wherein the ink head module has an energy generating element that forms a part of the ink chamber and that applies ejection energy required for ejection to the ink. In the ink head, in which a plurality of nozzles are formed for each of the ink chambers, ink droplets ejected from each nozzle are ejected at an ejection timing different from the ejection timing of ink droplets ejected from an adjacent nozzle. An ink head characterized in that: 2. The method according to claim 1, wherein each of the nozzles has a distance from a center of ejection energy in the ink chamber generated by driving the energy generating element different from that of an adjacent nozzle.
The ink head according to claim 1, wherein the ink head is arranged. 3. An ink head module having a plurality of ink chambers for discharging ink, a nozzle plate attached to the ink head module for providing nozzles for passing ink to each of the ink chambers, and Wherein the ink head module has an energy generating element that forms a part of the ink chamber and provides ejection energy required for ejection to the ink, In the ink head, a plurality of nozzles are formed for each of the ink chambers, wherein the ink droplets ejected from each nozzle are ejected at an ejection speed different from the ejection speed of an adjacent ink droplet. Ink head. 4. The ink head according to claim 3, wherein the nozzle has an opening area different from that of the adjacent nozzle.