JPH07241989A - Ink jet print head - Google Patents

Abstract

PURPOSE:To securely maintain the cleanness for parts surrounding nozzles and provide a high quality printing head. CONSTITUTION:A passage 14 and a pressure chamber 16 are formed to the side of the upper bed 22 of a passage base plate 10, and a plurality of projections 50 are formed to the side of a nozzle-forming surface 24 that is formed at the gradient in a specified degree theta1 against the undersurface 26 of the passage base plate 10 for forming the nozzles. The nozzles 20 are formed respectively to the projections 50. The surface of the projection 50 is smaller as compared with the nozzle-forming surface 24 of the passage base plate 10. When cleaning is applied to the nozzle-forming surface 24 of the passage base plate 10, dirt or stains by ink around the nozzles 20 on the projections 50 can be removed easily from the surfaces of the projections 50, and the cleanness can be secured for the surfaces of the projections 50.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in printers, fax machines, plotters, bar code printers, digital copiers, etc., and has a structure of an ink jet print head for printing by ejecting ink from nozzles and adhering it to a recording medium. Regarding

[0002]

2. Description of the Related Art Conventionally, there is known an ink jet print head which prints by ejecting ink from a nozzle hole and adhering it to a recording medium by utilizing the vibration of a piezoelectric element by applying a voltage, without bringing the head into contact with the recording medium. Has been.

An ink jet print head disclosed in Japanese Patent Laid-Open No. 3-75153 will be described below with reference to FIGS. 13, 14 and 15.

FIG. 13 is a view showing a flow path substrate of a so-called side shoot type ink jet print head in which ink is ejected from the lower surface side of the flow path substrate, and FIG. 14 is shown in FIG.
3 is a sectional view taken along line CC of FIG.

In the figure, on the upper surface 22 side of the flow path substrate 10, a common flow path 12 receiving ink supply from an ink supply section (not shown), a plurality of pressure chambers 16 and a common flow path 1 are provided.
The flow path 14 that connects the pressure chamber 16 and the pressure chamber 16 is formed in a groove shape.

The nozzle channel 72 is formed so as to penetrate from the end of each pressure chamber 16 in the thickness direction of the channel substrate 10.
Further, the pressure chamber 1 is communicated with the nozzle flow path 72, and
The nozzle holes 70 for ejecting ink from the nozzle 6 are
On the lower surface 26 side of No. 0, a plurality is formed as shown in FIG.

The upper surface 22 of the flow path substrate 10 and the ejection direction of the ink ejected from the nozzle holes 70 (ink ejection axis).
The inclination θ3 with respect to 60 and the inclination θ2 with respect to the lower surface 26 and the ink ejection shaft 60 are approximately 90 degrees.

A vibrating plate (not shown) is joined to the upper surface 22 of the flow path substrate 10 so that the upper parts of the common flow path 12, the pressure chambers 16 and the like are closed to form an ink flow path. It Piezoelectric elements are arranged on the vibrating plate at positions corresponding to the respective pressure chambers 16.

In the thus constructed ink jet print head, when a voltage is applied to the piezoelectric element to vibrate the piezoelectric element, the vibrating plate causes this vibration to occur in the pressure chamber 16.
To change the volume of the pressure chamber 16. Then, depending on the volume change amount of the pressure chamber 16, the lower surface 26 of the flow path substrate 10 is
A desired amount of ink is ejected from the nozzle hole 70 formed on the side, and the ink adheres to a recording medium (not shown) supplied in a direction parallel to the lower surface 26 of the flow path substrate 10 for printing.

Further, the ink jet print head is
Since it is a mechanism for ejecting ink from the nozzle hole 70,
Conventionally, there has been a possibility that ink adheres to the periphery of the nozzle hole 70 and is contaminated, or the nozzle flow path 72, the nozzle hole 70, and the like are clogged to deteriorate the print quality.

Therefore, the lower surface 26 of the flow path substrate 10, which is the surface on which the nozzle holes 70 are formed, is cleaned every predetermined period.

In the cleaning, for example, by wiping the lower surface 26 of the flow path substrate 10 with a wiper blade made of rubber or the like, ink stains and dust adhering to the periphery of the nozzle hole 70 are removed and stains adhere to the recording medium. The print quality is prevented from being deteriorated by blocking the nozzle holes 70 and the like.

[0013]

However, in the conventional ink jet print head, the flow path substrate 1 is used.
Since the lower surface 26 of 0 has a planar shape and has a large area, the lower surface 2 of the flow path substrate 10 is formed by using a wiper blade.
When cleaning No. 6, it was difficult to completely remove the ink adhering to the periphery of the nozzle hole 70 from the lower surface 26.

Therefore, even after cleaning, ink stains still remain on the lower surface 26 of the flow path substrate 10, the cleanliness around the nozzle holes 70 cannot be maintained, and the ink stains adhere to or remain on the recording medium. There is a possibility that the nozzle holes 70 are blocked due to the ink stains.

Further, in the manufacturing process of the ink jet print head, in order to adjust the shape of the nozzle hole 70,
The lower surface 26 of the flow path substrate 10 is polished. However, the nozzle channel 72 is formed in the thickness direction of the channel substrate 10.
Is formed, the lower surface 26 around the nozzle hole 70 is formed.
Is thinner than other portions of the flow path substrate 10. Therefore, at the time of polishing, the pressing force of the grindstone easily causes a bend around the nozzle hole 70,
There is a problem that normal polishing cannot be performed, and further, the polishing rather deteriorates the uniformity of the shape of the nozzle hole 70 and the flatness of the lower surface 26.

When the flow channel substrate 10 is integrally formed of resin, the nozzle flow channel 72 communicating with the nozzle hole 70 is formed in the thickness direction of the flow channel substrate 10, so that the flow channel substrate 10 is formed. The thickness of the substrate is significantly different between the periphery of the nozzle hole 70 and other portions of the flow path substrate 10.

Generally, in resin molding, sink marks or deformations of the molded product are likely to occur in a region where the difference in resin thickness is large. Therefore, in the vicinity of the nozzle hole 70 where the highest accuracy is required, the resin-molded flow path substrate 10 may suffer sink marks or deformation due to the difference in thickness, resulting in defective molding.

On the other hand, for the ink jet print head as shown in FIG. 13, the print quality due to the large opposing area between the recording medium and the lower surface 26 of the flow path substrate 10 in which the nozzle holes 70 are formed. There has been a demand for a print head in which the pressing member for the recording medium can be arranged as close to the nozzle hole as possible in order to prevent the deterioration of the recording medium and improve the feeding accuracy of the recording medium.

In order to solve this, an ink jet print head as shown in FIG. 16 has been proposed. In the inkjet print head of FIG. 16, the pressure chamber 16 is formed on the upper surface 22 side of the flow path substrate 10, and the pressure chamber 1
The nozzle flow path 18 communicated with the nozzle 6 is formed in the thickness direction of the flow path substrate 10. The nozzle hole 20 is formed in the nozzle hole forming surface 24 having an inclination θ1 with respect to the lower surface 26 of the flow path substrate 10.

According to the ink jet print head having such a structure, the facing area between the recording medium 62 and the nozzle hole forming surface 24 can be reduced, and the pressing member of the recording medium 62 can be used as the nozzle hole 20. It can be placed at the latest position, and the printing quality can be improved.

However, in the print head of FIG. 16 as well, the nozzle hole forming surface 24 has a planar shape similar to the lower surface 26 of the flow path substrate 10 in which the nozzle holes 70 of FIG. 13 are formed, and therefore cleaning is performed. However, the ink stains could not be completely removed from the nozzle hole forming surface 24, and the cleanliness of the nozzle hole forming surface 24 could not be maintained.
Further, similarly to the print head of FIG. 13, poor polishing of the nozzle hole forming surface and the flow path substrate 1 around the nozzle hole 20.
However, there is a problem that the print quality is deteriorated due to defective molding of 0 or the like.

The present invention has been made to solve these problems, and an object of the present invention is to provide an ink jet print head of high print quality, which reliably maintains the cleanliness around the nozzle holes.

[0023]

In order to achieve the above object, the ink jet print head according to the present invention has the following features.

A flow channel having a pressure chamber for delivering ink, a nozzle flow channel communicating with the pressure chamber, and a nozzle hole for ejecting ink by a volume change of the pressure chamber via the nozzle flow channel. A substrate, wherein the pressure chamber is formed on the upper surface side of the channel substrate, the nozzle channels are formed in a substantially thickness direction of the channel substrate, and a plurality of nozzle holes are formed on the lower surface side of the channel substrate. In the inkjet print head having the above, the nozzle hole is formed in a projecting portion provided on a lower surface of the flow path substrate.

A plurality of pressure chambers for delivering ink, a nozzle channel communicating with the pressure chamber, and a plurality of nozzle holes for ejecting ink due to a volume change of the pressure chamber through the nozzle channel are formed. In the ink jet print head having the flow channel substrate, the pressure chamber is provided on the upper surface side of the flow channel substrate, and the nozzle flow channel is formed substantially in the thickness direction of the flow channel substrate. The formed nozzle hole forming surface is formed so as to be inclined with respect to the lower surface of the flow path substrate, and the nozzle hole forming surface is provided with a protruding portion in which the nozzle hole is formed. .

The projecting portion is formed independently for each nozzle hole.

A groove is formed around the protrusion.

A plurality of pressure chambers for delivering ink, a nozzle flow path communicating with the pressure chambers, and a plurality of nozzle holes for ejecting ink by the volume change of the pressure chambers through the nozzle flow paths are formed. In the ink jet print head having the flow channel substrate, the pressure chamber is provided on the upper surface side of the flow channel substrate, and the nozzle flow channel is formed substantially in the thickness direction of the flow channel substrate. The formed nozzle hole forming surface is formed so as to be inclined with respect to the lower surface of the flow path substrate, and grooves are formed in the nozzle hole forming surface at least between the nozzle holes.

The flow channel substrate is characterized by being made of a thermoplastic resin or a thermosetting resin.

[0030]

The flow path substrate of the ink jet print head according to the present invention is provided with the protruding portion having the nozzle hole formed on the lower surface of the flow path substrate or the nozzle hole forming surface. The surface of the protrusion is
The size is smaller than the lower surface of the flow path substrate and the nozzle hole forming surface, and if the lower surface of the flow path substrate and the nozzle hole forming surface are cleaned using a wiper blade, ink and dust attached to the periphery of the nozzle hole of the protruding portion Can be easily removed from the surface of the protrusion.

Therefore, it is possible to reliably maintain the cleanliness of the periphery of the nozzle hole, and it is possible to prevent ink stains, dust, and the like from adhering to the recording medium and the nozzle hole from being clogged. It can be prevented.

By making the protrusions independent for each nozzle hole, ink and dust removed from the surface of the protrusions can be held between adjacent protrusions.
The effectiveness of cleaning is improved. Furthermore, if a groove is formed around this protrusion, it becomes easy to reliably hold the ink and dust removed from the protrusion in this groove,
It is also possible to remove ink and dust adhering to the wiper blade with this groove.

Further, even if the surface of the protruding portion is subjected to a polishing treatment to adjust the shape of the nozzle hole, the strength of the protruding portion which receives the pressing force of the grindstone becomes uniform, so that the surface of the protruding portion may be distorted by polishing. Is extremely low. Therefore, the periphery of the nozzle hole can be surely polished.

When the flow path substrate is made of resin, the difference in thickness is mitigated by providing a protrusion or a groove around the nozzle hole, which has a large difference from the thickness of other portions of the flow path substrate. Therefore, it is possible to reduce the occurrence of sink marks, deformation, and the like near the nozzle holes of the flow path substrate during resin molding. Therefore, it is possible to reduce the variation in the size and shape of the nozzle holes, which directly affects the variation in the ink ejection amount.

[0035]

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

(Example 1) (Example 1-1) FIG. 1 is an assembly view of an ink jet print head according to an example of the present invention, and FIG.
FIG. 3 is a schematic configuration diagram showing a cross section of the inkjet print head corresponding to line −A, and FIG. 3 is an enlarged perspective view of the flow path substrate 10 of FIG. 2. It should be noted that the same parts as those in the drawings already described are designated by the same reference numerals and the description thereof will be omitted.

In the figure, on the upper surface 22 side of the flow path substrate 10, a common flow path 12 receiving ink supply from an ink supply section 44, a plurality of pressure chambers 16, and a common flow path 12 and each pressure chamber 16 are provided. The flow path 14 that communicates with each other is formed in a groove shape. The nozzle channel 18 is formed with an inclination θ3 (θ3> 0 °, in the present embodiment, θ3 = 85 °) from the end of each pressure chamber 16 to the upper surface 22 of the channel substrate 10.

The lower surface 2 is provided on one end side of the lower surface 26 of the flow path substrate 10 which is the opposite surface of the upper surface 22 of the flow path substrate 10.
6 is provided with a nozzle forming surface 24 having a predetermined inclination θ1.

The nozzle forming surface 24 is provided with a plurality of protrusions 50, which is a feature of this embodiment, and the surfaces of the protrusions 50 are connected to the pressure chambers 16 via the nozzle flow paths 18, respectively. A nozzle hole 20 is formed. Protruding part 5
The protrusion amount from the nozzle hole forming surface 24 of 0 is, for example, 0.5.
The arrangement interval is equal to the pitch of the nozzle holes 20. The surface of the protrusion 50 and the nozzle hole forming surface 24 are formed substantially parallel to each other. The protrusion 50 has a cylindrical shape or a truncated cone shape in FIG. 3, but is not limited to this and may have a quadrangular prism shape as shown in FIG.

The inclination θ2 between the nozzle hole forming surface 24 and the surfaces of the protrusions 50 (at least the surfaces of the protrusions 50) and the ink ejection shaft 60 indicating the ink ejection direction is approximately 90 degrees. If formed, the nozzle hole 20 will have a circular shape, and the ejected ink droplets will likely have a spherical shape,
It can contribute to the improvement of printing quality. However, the slope θ2 is not limited to the above value as long as there is practically no problem.

In the figure, 40 is a sealing plate for sealing the opening of the ink flow path between the ink supply section 44 and the common flow path 12, and 42 is dust in the ink common to the ink supply section 44. It is a strainer for preventing it from entering the flow path 12.

In this embodiment, the flow path substrate 10 is used.
Is made of glass or resin. When the flow path substrate 10 is made of resin, the flow path substrate 10 is integrally formed using a thermoplastic resin such as polysulfone, polyether sulfone, polycarbonate, polyarylate, or a thermosetting resin such as an epoxy resin. preferable.

The surface of the protruding portion 50 of the flow path substrate 10 may be separately subjected to a polishing treatment using a grindstone to adjust the shape of the nozzle hole 20.

Next, the structure of the entire ink jet print head using the flow path substrate 10 will be described.

A vibrating plate 32 for efficiently transmitting the vibration of the piezoelectric element 30 to each pressure chamber 16 is bonded to the upper surface 22 side of the flow path substrate 10 with the plastic film 34 as the flow path substrate 10 side. Then, the vibration plate 32 is joined to the upper surface 22 of the flow path substrate 10 to close the upper parts of the common flow path 12, the pressure chamber 16 and the like to form an ink flow path.

The vibrating plate 32 includes a plastic film 34 having a thickness of 50 to 300 μm, for example, about 200 μm, and a common electrode 36 having a thickness of 10 to 30 μm, for example, 10 μm and made of conductive Al or the like, which is previously rolled. What is formed by adhering with an adhesive while pressurizing with, etc., or the common electrode 36 is made of conductive A1, Ni, ITO, etc.
Thousands of Å formed by sputtering or vapor deposition.

The common electrode 36 can be applied as long as it is a conductive material, and when the vibrating plate 32 and the flow path substrate 10 are joined by heat fusion, Al having a linear expansion coefficient close to that of the resin is used.
Is preferred.

Piezoelectric elements 30 which vibrate when a voltage is applied are arranged at positions corresponding to the pressure chambers 16 on the vibrating plate 32. In addition, the flexible cable 46
Are connected to the piezoelectric element 30 and the common electrode 36, and wiring for applying a voltage signal to each piezoelectric element 30 is formed.

In such an ink jet print head, a voltage is applied to each piezoelectric element 30 by the flexible cable 46 and the common electrode 36, and the piezoelectric element 30 vibrates. The vibration plate 32 transmits this vibration to the corresponding pressure chambers 16 and changes the volume of the pressure chambers 16. Further, due to this volume change, ink is ejected from the nozzle hole 20 that is communicated with each pressure chamber 16 and is formed in the protruding portion 50 of the nozzle hole forming surface 24.

On the other hand, the recording medium 62 such as paper or film is
Ink that is supplied from the direction parallel to the nozzle hole forming surface 24 by the feeding mechanism such as a pressing member of the recording medium 62 and ejected from the nozzle holes 20 adheres to the recording medium 62 for printing.

In this embodiment, the nozzle holes are formed on the surface of the flow path substrate 10 having a predetermined inclination with respect to the lower surface 26, so that the recording medium 62 such as paper and the nozzle hole forming surface 24 are formed. It is possible to minimize the facing area of the nozzles and obtain the small nozzle hole forming surface 24, so that the pressing member of the recording medium 62 can be arranged at the most recent position of the nozzle holes, and the printing quality is improved. You can

Further, since the ink jet print head according to the present embodiment is a mechanism for ejecting ink from the nozzle holes 20 as in the conventional case, the ink adheres to the periphery of the nozzle holes 20 and becomes dirty, or the nozzle flow path 18 is formed. Also, the nozzle hole 20 may be clogged. Therefore, the cleaning of the nozzle hole forming surface 24 side is performed every predetermined period.

For example, in the case of a cleaning method of wiping the nozzle hole forming surface 24 of the flow path substrate 10 with a wiper blade made of a rubber material or the like, the nozzle hole 20 is formed on the nozzle hole forming surface 24 of the flow path substrate 10. By providing the protrusion 50, the embodiment of the present invention has the following remarkable effects.

That is, the area of the protrusion 50 is equal to that of the flow path substrate 10.
Since the nozzle hole forming surface 24 is smaller than the nozzle hole forming surface 24, ink and dust adhering to the periphery of the nozzle hole 20 of the protrusion 50 can be extremely easily removed from the surface of the protrusion 50 by the wiper blade.

Therefore, it is possible to reliably maintain the cleanliness of the periphery of the nozzle hole, and to prevent ink stains or dust from adhering to the recording medium or from clogging the nozzle hole. it can.

Further, as shown in FIGS. 3 and 4, the protrusions 50 are independent for each nozzle hole 20, so that the ink or dust removed from the surface of the protrusions is provided between the adjacent protrusions. It can be held, and the effectiveness of cleaning around the nozzle holes is improved.

In this embodiment, the flow path substrate 10
Is, for example, polysulfone, polyether sulfone,
Alternatively, when integrally formed using a thermoplastic resin such as polycarbonate or polyarylate or a thermosetting resin such as an epoxy resin, the following effects are obtained.

That is, when the flow path substrate is formed of resin, the substantial thickness in the vicinity of the nozzle hole 20 of the flow path substrate 10 and the substantial thickness of the other parts of the flow path substrate 10 are the protrusions. By providing 50, the difference is reduced.

Generally, in resin molding, sinking or deformation of the molded product is likely to occur in a region where the difference in resin thickness is large. However, since the difference in the thickness of the resin substrate is alleviated by providing the protruding portion, it is possible to minimize the occurrence of sink marks, deformation, and the like in the vicinity of the nozzle hole that requires the most precision.

Therefore, it is possible to provide a flow path substrate which is extremely inexpensive and has high molding precision, and it is possible to contribute to cost reduction of the ink jet print head.

Further, in the flow path substrate according to the present embodiment, since the strength of the protruding portion which receives the pressing force of the grindstone during polishing becomes uniform, the possibility that the surface of this protruding portion is distorted by polishing is extremely low. Therefore, the periphery of the nozzle hole can be surely polished, and the shape of the nozzle hole can be adjusted more accurately and reliably. Further, since the flatness of the surface of the protruding portion can be improved, it becomes difficult for ink stains and the like to adhere to the surface of the protruding portion, and the ejection performance is also improved.

Further, in this embodiment, by providing the projection portion on the nozzle hole forming surface, the nozzle hole forming surface can be kept away from the recording medium, and the possibility that the nozzle hole forming surface and the recording medium come into contact is reduced. In addition, since it is possible to prevent ink bleeding on the recording medium and adhesion of ink stains on the recording medium due to contact, it is possible to significantly improve the printing quality.

(Embodiment 1-2) Next, an example of a flow path substrate having a structure different from that of the flow path substrate of Example 1-1 will be described with reference to FIGS.

The flow channel substrate of FIG. 5 is characterized in that the groove 52 is provided around the protruding portion 50 of the nozzle hole forming surface 24 shown in FIG. The bottom of the groove 52 is the lower surface 2 of the flow path substrate 10.
It is formed substantially in parallel with 6. Although the depth of the groove 52 at the deepest portion varies depending on the thickness, size, etc. of the flow channel substrate 10, for example, it is set to 1 mm with respect to the average thickness of the flow channel substrate 10 of 2 mm.

By providing the groove 52 around the protrusion 50, ink stains and dust removed from the protrusion 50 by cleaning can be held more reliably in the groove 52 and adhered to the wiper blade. It is also possible to remove the generated ink and dust by this groove 52.

Therefore, the cleanliness of the surface of the protruding portion can be maintained more reliably.

By providing this groove 52,
The difference between the thickness of the other part of the flow path substrate 10 and the thickness in the vicinity of the nozzle hole 20 can be made smaller, and when the flow path substrate 10 is made of resin, a molding defect such as sink or deformation of the substrate near the nozzle hole 20. Can be reduced.

When the polishing treatment is applied to the vicinity of the nozzle hole 20, the polishing failure can be reduced as in the case of Example 1-1.

(Example 1-3) Next, Examples 1-1 and 1-2
An example of a flow channel substrate having a configuration different from that of the flow channel substrate will be described with reference to FIGS. 7 and 8.

Grooves 54 having the same depth are provided on the flow path substrate 10 along the horizontal direction of the nozzle holes 20 above and below the protrusion 50 in the figure. Further, a groove 56, which is shallower than the groove 54, is provided between each nozzle hole 20, and the protrusion 50 is separated corresponding to each nozzle hole 20.

Since the protrusions 50 are independent for each nozzle hole 20 as described above, the surface of the protrusion 50 is located between the adjacent protrusions 50 on the nozzle hole forming surface 24 of the flow path substrate 10. It is easy to hold the ink and dust removed from the nozzles, and the effectiveness of cleaning around the nozzle holes is improved.

Further, since the removed ink or dust has a large storage capacity, it is possible to reliably maintain the cleanliness of the surface of the protrusion during use of the print head.

(Embodiment 1-4) A flow path substrate having a different structure from the above embodiment will be described with reference to FIG.

The feature of the flow path substrate 10 shown in FIG. 9 is that grooves 58 are formed between the nozzle holes 20 formed on the nozzle hole forming surface 24.
Is provided, and each protrusion 50 is configured. With the extremely simple configuration of providing the groove 58 on the nozzle hole forming surface 24, the ink and dust removed from the surface of the protrusion 50 can be retained in the groove 58, and the effectiveness of cleaning in the vicinity of the nozzle hole is improved. And the cleanliness of the surface of the protruding portion can be maintained.

In the first embodiment, the nozzle flow path 18 has the same inclination θ3 with respect to the upper surface 22 of the flow path substrate 10 as the ink ejection shaft 60. On the other hand, if the inclination θ3 is 90 degrees, the upper surface of the flow path substrate can be molded with a single mold, and the mold can be easily removed from the mold to improve work efficiency.

(Embodiment 2) Next, an example of a so-called serial type ink jet print head different from that of Embodiment 1 will be described with reference to FIGS.

In the figure, on the side of the upper surface 22 of the flow path substrate 10, a plurality of pressure chambers 16 to which ink is supplied from an ink supply section (not shown) are arranged in parallel or in an arc shape. A nozzle channel 72 penetrating in the thickness direction of the channel substrate 10 communicates with each pressure chamber 16.

Further, on the lower surface side 26 of the flow path substrate 10,
The protrusions 50 similar to those in the example 1-1 are provided in two rows. Then, nozzle holes 70 communicating with the nozzle flow paths 72 are formed on the surface of the protrusion 50.

In this embodiment, as is apparent from FIG. 10, the area itself of the lower surface 26 of the flow path substrate 10 in which the nozzle holes 70 are formed is large, but the lower surface 2 of this flow path substrate 10 is large.
By providing the protrusion 50 on the nozzle 6, the ink and dust adhering to the periphery of the nozzle hole 70 of the protrusion 50 can be easily removed from the surface of the protrusion 50 by the wiper blade when cleaning the flow path substrate 10.

Therefore, it is possible to reliably maintain the cleanliness around the nozzle holes by cleaning, and prevent ink stains and dust from adhering to the recording medium and blocking the nozzle holes by these. You can

Since the protrusions are independent for each nozzle hole, the ink and dust removed from the surface of the protrusions can be held between the adjacent protrusions on the lower surface of the flow path substrate. The effectiveness of cleaning around the nozzle hole is improved.

Further, similarly to the first embodiment, in the flow path substrate according to the present embodiment, the polishing process may be performed on the surface of the protrusion 50, and the strength of the protrusion that receives the pressing force of the grindstone is uniform. Thus, the possibility that the surface of the protrusion 50 is distorted by polishing is extremely low, and the periphery of the nozzle hole can be reliably polished.
Therefore, the shape of the nozzle hole can be adjusted more accurately and surely. Further, since the flatness of the surface of the protruding portion can be improved by the polishing treatment, it becomes possible to make it difficult for ink stains and the like to adhere to the surface of the protruding portion.

Even when the flow path substrate 10 is integrally formed by using a thermosetting resin such as a thermoplastic resin or an epoxy resin, by providing the protrusion 50, the vicinity of the nozzle hole 20 of the flow path substrate 10 is provided. Substantial thickness of the flow path substrate 1
The difference with the substantial thickness of the other part of 0 can be relaxed. This can reduce molding defects.

As shown in FIG. 12, the flow path substrate 10
Also in the print head in which the protrusions 50 in which the nozzle holes 70 are formed on the lower surface 26 of the above are arranged in a substantially rhombic shape,
The cleanliness of the surface of the protrusion 50 can be reliably maintained. In addition, molding defects and polishing defects can be prevented. When the protrusions 50 and the nozzle holes 70 are arranged in a rhombus as shown in FIG. 12, there is a margin in the formation pitch of the pressure chambers formed on the upper surface side of the flow path substrate 10, and the pressure chambers and the nozzle holes 70 are formed. Since the distance can be reduced, a print head having high ink ejection capability can be obtained. Further, when the flow path substrate 10 is formed by resin molding, a protruding pin can be provided at the center of the diamond array of the nozzle holes 70 on the lower surface 26 of the flow path substrate,
The flow path substrate can be easily removed from the molding die, and work efficiency is improved.

In this embodiment, by providing the protrusion on the lower surface of the flow path substrate, the lower surface of the flow path substrate having a large area can be moved away from the recording medium, and the possibility that the lower surface and the recording medium contact each other is reduced. In addition, since it is possible to prevent ink bleeding on the recording medium and adhesion of ink stains on the recording medium due to contact, it is possible to significantly improve print quality.

[0086]

As described above, in the ink jet print head according to the present invention, the protruding portion having the nozzle hole is provided on the lower surface of the flow path substrate or the nozzle hole forming surface.

The surface of the protruding portion is smaller than the lower surface of the flow path substrate and the nozzle hole forming surface, and when cleaning the lower surface of the flow path substrate and the nozzle hole forming surface, the periphery of the nozzle hole of the protruding portion is The ink and dust adhering to the can be easily removed from the surface of the protrusion.

Therefore, it is possible to reliably maintain the cleanliness of the periphery of the nozzle hole by cleaning,
It is possible to prevent ink stains and dust from adhering to the recording medium, and prevent the nozzle holes from being blocked by these.

By making the protrusions independent for each nozzle hole, ink or dust removed from the surface of the protrusions is held between adjacent protrusions on the lower surface of the flow path substrate or the nozzle hole forming surface. Therefore, the effectiveness of cleaning around the nozzle holes is improved.

When grooves are formed around the projections on the lower surface of the flow path substrate or the nozzle hole forming surface, it is easier to hold the ink or dust removed from the projections in the grooves. It is also possible to remove ink and dust adhering to the wiper blade with this groove.

Further, by providing the protrusion, even if a polishing process for adjusting the shape of the nozzle hole is performed, the area of the protrusion that receives the pressing force of the grindstone is small, so that the surface of the protrusion is bent during polishing. The chances are extremely low. Therefore,
The periphery of the nozzle hole can be surely polished.

Further, when the flow path substrate is formed by integral molding of resin, the difference in the thickness can be reduced by providing the protruding portion around the nozzle hole, which has the most difference from the thickness of other portions of the flow path substrate. Therefore, it is possible to reduce the occurrence of sink marks and deformation near the nozzle holes during molding. This makes it possible to reduce variations in size and shape of each nozzle flow path and nozzle hole.

By providing a nozzle hole in the protruding portion,
The lower surface of the flow path substrate and the nozzle hole forming surface can be distanced from the recording medium such as paper, and the possibility that the lower surface and the nozzle hole forming surface come into contact with the recording medium can be reduced. Since it is possible to prevent ink stains or the like from adhering to the recording medium, it is possible to significantly improve print quality.

[Brief description of drawings]

FIG. 1 is an assembly diagram of an inkjet printhead according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a cross section of the inkjet print head corresponding to line AA in FIG.

3 is an enlarged perspective view of the flow path substrate 10 of FIG.

FIG. 4 is an enlarged perspective view of a flow path substrate having a protrusion different from that of FIG.

FIG. 5 is an enlarged perspective view of a channel substrate according to Example 1-2.

6 is an enlarged cross-sectional view of the flow path substrate 10 of FIG.

FIG. 7 is an enlarged perspective view of a flow path substrate according to Example 1-3.

8 is an enlarged cross-sectional view of the flow path substrate 10 of FIG.

FIG. 9 is an enlarged perspective view of a flow path substrate according to Example 1-4.

FIG. 10 is a diagram illustrating the lower surface of the flow path substrate of the inkjet print head according to the second embodiment.

11 is a schematic cross-sectional view taken along the line BB of FIG.

FIG. 12 is a diagram showing a lower surface of a flow path substrate of an ink jet print head according to a second embodiment having a configuration different from that of FIG.

FIG. 13 is a diagram showing an upper surface of a flow path substrate of a conventional inkjet printhead.

14 is a cross-sectional view of the flow channel substrate 10 taken along the line CC of FIG.

15 is a diagram showing a lower surface of the flow path substrate 10 of FIG.

FIG. 16 is a schematic configuration diagram showing a cross section of an ink jet print head different from that of FIG.

[Explanation of symbols]

 10 flow path substrate 12 common flow path 14 flow path 16 pressure chamber 18, 72 nozzle flow path 20, 70 nozzle hole 22 upper surface of flow path substrate 24 nozzle hole forming surface 26 lower surface of flow path substrate 30 piezoelectric element 32 vibrating plate 50 protrusion Part 52, 54, 56, 58 Groove

Claims (6)

[Claims] 1. A pressure chamber for delivering ink, a nozzle channel communicating with the pressure chamber, and a nozzle hole for ejecting ink by a volume change of the pressure chamber via the nozzle channel. A flow channel substrate, wherein the pressure chambers are formed on the upper surface side of the flow channel substrate, the nozzle flow channels are formed substantially in the thickness direction of the flow channel substrate, and a plurality of nozzle holes are formed on the lower surface side of the flow channel substrate. An inkjet printhead having a substrate, wherein the nozzle hole is formed in a protrusion provided on the lower surface of the flow path substrate. 2. A plurality of pressure chambers for delivering ink, a nozzle flow path communicating with the pressure chambers, and a plurality of nozzle holes for ejecting ink by a volume change of the pressure chambers through the nozzle flow paths. An ink jet print head having a flow path substrate formed, wherein the pressure chamber is provided on an upper surface side of the flow path substrate, and the nozzle flow path is formed substantially in a thickness direction of the flow path substrate. The nozzle hole forming surface in which the holes are formed is formed with an inclination with respect to the lower surface of the flow path substrate, and the nozzle hole forming surface is provided with a protruding portion in which the nozzle hole is formed. And inkjet print head. 3. The inkjet printhead according to claim 1, wherein the protrusion is formed independently for each nozzle hole. 4. The inkjet printhead according to claim 1, wherein a groove is formed around the protrusion. head. 5. A plurality of pressure chambers for delivering ink, a nozzle channel communicating with the pressure chamber, and a plurality of nozzle holes for ejecting ink due to a volume change of the pressure chamber via the nozzle channel. An ink jet print head having a flow path substrate formed, wherein the pressure chamber is provided on an upper surface side of the flow path substrate, and the nozzle flow path is formed substantially in a thickness direction of the flow path substrate. The nozzle hole forming surface in which the holes are formed is formed so as to be inclined with respect to the lower surface of the flow path substrate, and grooves are formed on the nozzle hole forming surface at least between the nozzle holes. Inkjet print head. 6. The ink jet print head according to claim 1, wherein the flow path substrate is made of a thermoplastic resin or a thermosetting resin. Characteristic inkjet print head.