JP2000071460A - Orifice plate and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the machining time while enhancing the machining accuracy. SOLUTION: The orifice plate comprises a preliminary shaped hole 25 made in the surface S2 on the ink pressurizing chamber 24 side and an orifice formed by laser machining to conduct the ink pressurizing chamber 24 side with the ink drop ejecting side at the part of the preliminary shaped hole 25. Since the part of the preliminary shaped hole 25 is subjected to laser machining and an orifice is formed by conducting the ink pressurizing chamber 24 side with the ink drop ejecting side, no mask is required. Since alignment of mask and an original die 21 is not required, machining accuracy of an orifice plate can be enhanced. Since the machining thickness is decreased by an amount corresponding to the preliminary shaped hole 25, number of machining shots can be decreased resulting in shortening of machining time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an orifice plate and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, in an ink jet printer, a plurality of ink pressurizing chambers are formed in an ink jet head, and an orifice plate is provided at the tip of the ink jet head to pressurize ink in each ink pressurizing chamber. Accordingly, ink droplets are ejected from a plurality of orifices formed in the orifice plate, and an image is formed on a print medium. In this case, if ink accumulates (accumulates) around the orifice, an ejection failure occurs, or the trajectory of the ejected ink droplet is bent, thereby deteriorating the image quality. Further, if air is mixed into each of the ink pressurized chambers, it is not possible to sufficiently pressurize the ink in the ink pressurized chambers. In this case as well, a discharge failure occurs and the image quality is reduced.

Therefore, there has been provided an ink jet head having a water repellent layer formed at a predetermined position on the orifice plate. FIG. 2 is a sectional view of an orifice plate of a conventional ink jet head. In the figure, 1
Reference numeral 1 denotes an orifice plate, reference numeral 12 denotes an orifice, and reference numeral 13 denotes a water-repellent layer formed on the surface of the orifice plate 11 on the ink droplet ejection side. In this case, the orifice plate 1
Since the water-repellent layer 13 is formed on the surface of the first ink droplet ejection side, accumulation of ink around the orifice 12 can be suppressed. Therefore, ejection failure occurs,
Since the orbit of the ejected ink droplet is suppressed from being bent, it is possible to prevent the image quality from deteriorating.

However, when the surface of the water-repellent layer 13 is swept over the orifice plate 11 by a blade (not shown) in order to remove ink, attached dust and the like remaining on the surface of the water-repellent layer 13, the water-repellent layer 13 is damaged around the orifice 12. May stick. Therefore, an orifice plate 11 having a counterbore formed around the orifice 12 is provided.

FIG. 3 is a sectional view of an orifice plate of another conventional ink jet head. In the figure, 11
Is an orifice plate, 12 is an orifice, 13 is a water-repellent layer formed on the surface of the orifice plate 11 on the ink droplet ejection side, and 14 is a counterbore formed around the orifice 12.

In this case, the water repellent layer 13 may be damaged around the orifice 12 when it is swept by a blade (not shown) in order to remove the ink remaining on the surface of the water repellent layer 13 and the attached dust. Can be prevented. By the way, usually, each of the orifice plates 1
1 is made of resin so that the cost can be reduced and the shape can be set arbitrarily. In this case, each orifice 12 is fine (having a diameter of 20 to 50 [μ).
m]), burrs are generated on the periphery of the orifice 12. In addition, a weld line is generated on the inner surface of the orifice 12 due to the flow of the resin during molding.

Therefore, in manufacturing the orifice plate 11, a mold of the orifice plate 11 having no orifice 12 is formed, and then the orifice 12 is formed by subjecting the mold to laser processing. In this case, the laser beam is irradiated from the ink pressurizing chamber side after the mask is positioned with respect to the prototype.

[0008]

However, in the above-mentioned conventional method for manufacturing an orifice plate, if the mask is not accurately positioned with respect to the original pattern, the processing accuracy of the orifice plate 11 is reduced accordingly. The thickness of the orifice plate 11 (about 50 to 1)
00 [μm]) of the resin must be processed by the laser beam, so that the processing thickness is large and the number of processing shots needs to be increased accordingly, so the processing time becomes extremely long.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an orifice plate which solves the above-mentioned problems of the conventional method for manufacturing an orifice plate and which can not only increase the processing accuracy but also shorten the processing time. And

[0010]

For this purpose, in the orifice plate of the present invention, a preformed hole formed on the surface on the side of the ink pressurizing chamber and a laser formed by applying a laser beam to the orifice plate. The portion has an orifice communicating between the ink pressurizing chamber side and the ink droplet ejection side.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a first state diagram showing a method for manufacturing an orifice plate according to the first embodiment of the present invention, FIG. 4 is a front view of a prototype of the orifice plate according to the first embodiment of the present invention, and FIG. FIG. 6 is a second state diagram showing a method for manufacturing an orifice plate according to the first embodiment of the present invention, and FIG. 6 is a third state diagram showing a method for manufacturing an orifice plate according to the first embodiment of the present invention. .

In FIG. 1, reference numeral 21 denotes a prototype of an orifice plate 31 formed of a resin. A surface S1 of the prototype 21 on the ink droplet ejection side becomes a counterbore 33 when an orifice 32 is formed later. The recess 23 is formed at a predetermined depth. For this purpose, a plurality of convex portions are formed in the mold (not shown) of the prototype 21 in correspondence with the concave portions 23. As the resin, polyethersulfone, polysulfone, or the like having ink resistance and heat resistance is used.

The ink pressurizing chamber 24 of the prototype 21
A preformed hole 25 that will later become the orifice 32 is formed in the side surface S2. In this case, the depth of the preformed hole 25 is a predetermined thickness δ between the preformed hole 25 and the bottom surface 23a of the concave portion 23.
It is set so that a thin closed portion P1 made of the resin 1 is formed. The centers of the recess 23, the preformed hole 25, and the orifice 32 are aligned with each other. From various experiments, it has been found that the minimum thickness δ1 at which the closed portion P1 can be favorably formed is 5 to 40 μm.

In this case, since the closing portion P1 is formed,
The resin flow during molding can be made uniform.
Therefore, it is possible to suppress the occurrence of weld lines due to molding. Subsequently, the prototype 21 is subjected to laser processing from the ink droplet ejection side. For this purpose, a laser light irradiator (not shown) is provided so as to face the surface S1, and the laser light emitted from the laser light irradiator is used to emit the laser light from the surface S1 as shown by an arrow in FIG.
Is uniformly irradiated to remove the resin in the region AR1 (the portion shown by oblique lines in FIG. 5). At this time, since the closed portion P1 is removed, the ink droplet ejection side and the ink pressurizing chamber 24 side of the prototype 21 are communicated via the preforming hole 25.

In this case, when a YAG laser beam, a CO ₂ laser beam or the like is used as the laser beam, the surface roughness of the processed surface becomes relatively high, and the finish after the removal of the closed portion P1 is not good. . On the other hand, when excimer laser light is used as laser light, laser processing at the molecular level by ablation becomes possible, so that not only the surface roughness of the processed surface can be extremely reduced, but also the closed portion P1 Can be made very good after the removal of

Subsequently, as shown in FIGS. 5 and 6, a surface S of the prototype 21 from which the resin in the region AR1 has been removed.
3 is coated with a material such as a fluorine-based or silicon-based material by coating, vapor deposition, sputtering, or the like, to form a water-repellent layer 34. Thus, the orifice plate 31 including the plurality of orifices 32 can be manufactured. A counterbore 33 having a predetermined depth is provided around the orifice 32 on the surface S4 on the ink droplet ejection side of the orifice plate 31.
Is formed.

In this case, since the water-repellent layer 34 is formed on the surface S4 of the orifice plate 31 on the ink droplet ejection side, the accumulation of ink around the orifice 32 can be suppressed. Therefore, the occurrence of ejection failure and the curving of the trajectory of the ejected ink droplets are suppressed, so that it is possible to prevent the image quality from deteriorating. As described above, since the orifices 32 are formed by performing laser processing on the prototype 21, even when each orifice 32 is fine (having a diameter of 20 to 50 [μm]), burrs are generated on the peripheral edge of the orifice 32. Never.

Since the resin in the area AR1 is removed by irradiating a laser beam, it is not necessary to use a mask. Therefore, prototype 2
Since there is no need to align the mask with respect to 1, the processing accuracy of the orifice plate 31 can be increased. Since the positional accuracy of the spot facing portion 33 with respect to the orifice plate 31 may be low, the positioning when performing the laser processing is facilitated. Therefore, the cost of the orifice plate 31 can be reduced.

Further, it is only necessary to remove the resin having a thickness of δ1 to form the orifice 32.
Since the processing thickness is reduced by an amount corresponding to the formation of 5, the number of processing shots can be reduced correspondingly, and the processing time can be shortened. Next, a second embodiment of the present invention will be described. FIG. 7 is a front view of a prototype of the orifice plate according to the second embodiment of the present invention.

In the figure, 21 is a prototype, 25 is a preformed hole, and 35 is a recess. In this case, since the pitch of each preformed hole 25 is small, the concave portion 35 is formed to be long and common to each preformed hole 25. By the way, the first and second
In the embodiment, the depth of the spot facing portion 33 (FIG. 6) is about 3 to 15 [μm], and the spot facing diameter is 50 to 200 μm.
[Μm], which is fine, so that the spot facing portion 33 is easily wetted. Therefore, the water-repellent layer 3 is uniformly formed on the surface S3.
4 is difficult to form.

Therefore, a third embodiment of the present invention will be described in which the water-repellent layer 34 can be uniformly and easily formed on the surface S3. FIG. 8 shows a third embodiment of the present invention.
FIG. 9 is a first state diagram showing a method of manufacturing an orifice plate according to the third embodiment, FIG. 9 is a second state diagram showing a method of manufacturing an orifice plate according to the third embodiment of the present invention, and FIG. FIG. 11 is a third state diagram illustrating a method for manufacturing an orifice plate according to the third embodiment. FIG. 11 is a fourth state diagram illustrating a method for manufacturing an orifice plate according to the third embodiment of the present invention.

In the figure, reference numeral 21 denotes a prototype of an orifice plate 31 formed of resin, and a surface S12 of the prototype 21 on the ink pressurizing chamber 24 side is provided with an orifice 3 later.
2 are formed. In this case, the depth of the preformed hole 25 is set such that a closed portion P2 made of a resin having a predetermined thickness δ1 is formed between the preformed hole 25 and the surface S11 on the ink droplet ejection side. The centers of the preformed hole 25 and the orifice 32 are aligned with each other.

Subsequently, laser processing is performed on the prototype 21 from the ink droplet ejection side. Therefore, the surface S1
A laser light irradiator (not shown) is provided so as to face 1 and the laser light emitted from the laser light irradiator is
As shown by the arrow in FIG. 9, the entire surface S11 is uniformly irradiated to remove the resin in the region AR2 (the portion shown by oblique lines in FIG. 9). At this time, the closed portion P2 is removed, so that the ink droplet ejection side and the ink pressurizing chamber 24 side of the prototype 21 communicate with each other through the preforming hole 25.

Subsequently, as shown in FIG. 10, a surface S13 of the prototype 21 from which the resin in the region AR2 has been removed.
Is coated with a material such as a fluorine-based or silicon-based material by coating, vapor deposition, sputtering, or the like to form a water-repellent layer 54. In this case, the thickness δ2 of the water-repellent layer 54 is 5 to 20 μ
m]. Next, laser processing is performed again on the prototype 21 from the ink droplet ejection side, and a spot facing portion 55 is formed in the water-repellent layer 54. Thus, the orifice plate 31 having the plurality of orifices 32 can be formed.

As described above, since the counterbore portion 55 is formed by performing laser processing after forming the water-repellent layer 54, the water-repellent layer 54 can be easily formed. Further, since the positional accuracy of the counterbore portion 55 with respect to the orifice plate 31 may be low, the alignment when performing the laser processing is facilitated. By the way, in each of the above embodiments, the depth of the preformed hole 25 is set in advance. However, when the prototype 21 is formed, the depth of each preformed hole 25 may vary. is there. In this case, since the preformed hole 25 has a conical (conical) shape, the diameter of the orifice 32 increases as the depth of the preformed hole 25 increases, even if the closed portions P1 and P2 are removed only from portions having the same diameter. However, the smaller the depth, the smaller the size and the variation occurs.

Therefore, a fourth embodiment of the present invention will be described which can prevent the variation in the diameter of the orifice 32 even if the depth of the preformed hole 25 varies. FIG. 12 is a first state diagram showing a method for manufacturing an orifice plate according to the fourth embodiment of the present invention, and FIG. 13 is a second state showing a method for manufacturing an orifice plate according to the fourth embodiment of the present invention. FIG.

In this case, as shown in FIG. 12, each preformed hole 61 has a conical portion P5 whose inner wall extends with an inclination.
And formed adjacent to the closure P1, the inner wall of the surface S1,
It consists of a cylindrical part P6 with a diameter x and a length δ6 extending perpendicular to S2. Therefore, even when the depth of each preformed hole 61 varies during the molding of the prototype 21 and the positions of the respective bottoms 62 differ by, for example, the distance δ5, laser processing is performed as shown in FIG. After that, the diameter x of each orifice 63 formed in the orifice plate 31 can be made equal. In addition, 23 is a concave portion.

By the way, the prototype 21 shown in FIG.
When the orifice plate is manufactured using a water-repellent layer, the blade is swept over the orifice plate by a blade in order to remove ink remaining on the surface of the water-repellent layer, adhered dust, and the like. May be scratched. FIG. 14 is a first diagram showing a sweeping state by a blade, and FIG. 15 is a second diagram showing a sweeping state by a blade.

In the drawing, reference numeral 71 denotes an orifice plate,
72 is a counterbore, 73 is an orifice, 74 is a water-repellent layer, 7
Reference numeral 5 denotes a blade made of a flexible elastic member such as rubber which sweeps over the orifice plate 71 in order to remove ink remaining on the surface of the water-repellent layer 74 and dust attached thereto.
In this case, the counterbore 72 common to the plurality of orifices 73
However, in the orifice plate 71 in which a large number of orifices 73 are formed in order to increase the printing speed, the length δ7 of the spot facing portion 72 becomes longer. Further, the spot facing portion 72 is for preventing ink from adhering to the periphery of the orifice 73, and the spot facing depth is 3 to 2.
It is about 0 [μm] and shallow.

Therefore, since the blade 75 is formed of a flexible elastic member, the counterbore 72
When the longitudinal axis of the blade 75 coincides with the longitudinal axis of the blade 75, as shown in FIG. 15, at the center of the counterbore 72 in the longitudinal direction, the tip of the blade 75 , And the water-repellent layer 74 is scratched. In particular, the water-repellent layer 74 is easily damaged at the periphery of the orifice 73.

Therefore, a description will be given of a fifth embodiment of the present invention in which the water-repellent layer 74 is prevented from being damaged. FIG. 16 is a diagram showing a sweep state by a blade according to the fifth embodiment of the present invention. In the figure, 72 is a counterbore, 73 is an orifice, and 77 is a water-repellent layer 74 (FIG. 1).
5) A blade made of a flexible elastic member such as rubber which sweeps over the orifice plate 71 in order to remove the ink remaining on the surface and dust attached thereto. In this case, the longitudinal axis of the counterbore 72 is inclined at a predetermined angle θ with respect to the longitudinal axis of the blade 77.

Then, the orifice plate 7 is mounted on a carriage which is driven by driving means (not shown).
1 is mounted. on the other hand,
The blade 77 is disposed at a sweep portion set at a predetermined position of the main body of the ink jet printer, with the tip of the blade 77 facing the carriage. As the ink jet head passes through the sweep portion, the blade 77 is moved to the orifice plate 71. Sweep up. At this time, since the longitudinal axis of the counterbore 72 is inclined by the angle θ with respect to the longitudinal axis of the blade 77, the counterbore 72 and the blade 7
7, the distance δ8 at the portion where it contacts is shortened. Therefore, it is possible to prevent the tip of the blade 77 from touching the water-repellent layer 74.

The angle θ is calculated based on the distance δ8 and the amount by which the blade 77 bends (bends) toward the counterbore 72. In the present embodiment, the angle θ is 10 to 45 °.
To be. In the above embodiments, the closing part P1
(FIG. 1) When removing P2 (FIG. 8), laser light is irradiated from the ink droplet ejection side.
Irradiation can also be performed from the ink pressurizing chamber 24 side.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0035]

As described above in detail, according to the present invention, in the orifice plate, a preformed hole formed on the surface on the side of the ink pressurizing chamber and a laser formed by performing laser processing. An orifice communicating between the ink pressurizing chamber side and the ink droplet ejection side is provided at the preforming hole.

In this case, laser processing is performed on the preformed hole, and the ink pressurizing chamber side and the ink droplet discharge side are communicated to form an orifice. Therefore, it is not necessary to use a mask. Therefore, since it is not necessary to align the mask with the orifice plate prototype, the processing accuracy of the orifice plate can be increased.

In order to form the orifice, the processing thickness is reduced by the amount of the preformed hole, so that the number of processing shots can be reduced correspondingly and the processing time can be shortened.

[Brief description of the drawings]

FIG. 1 is a first state diagram showing a method for manufacturing an orifice plate according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of an orifice plate of a conventional inkjet head.

FIG. 3 is a cross-sectional view of an orifice plate of another conventional inkjet head.

FIG. 4 is a front view of a prototype of the orifice plate according to the first embodiment of the present invention.

FIG. 5 is a second state diagram showing the method for manufacturing the orifice plate according to the first embodiment of the present invention.

FIG. 6 is a third state diagram showing the method for manufacturing the orifice plate according to the first embodiment of the present invention.

FIG. 7 is a front view of a prototype of an orifice plate according to a second embodiment of the present invention.

FIG. 8 is a first state diagram illustrating a method for manufacturing an orifice plate according to a third embodiment of the present invention.

FIG. 9 is a second state diagram showing the method for manufacturing the orifice plate according to the third embodiment of the present invention.

FIG. 10 is a third state diagram showing the method for manufacturing the orifice plate according to the third embodiment of the present invention.

FIG. 11 is a fourth state diagram showing the method for manufacturing the orifice plate according to the third embodiment of the present invention.

FIG. 12 is a first state diagram illustrating a method for manufacturing an orifice plate according to a fourth embodiment of the present invention.

FIG. 13 is a second state diagram illustrating the method for manufacturing the orifice plate according to the fourth embodiment of the present invention.

FIG. 14 is a first diagram illustrating a sweep state by a blade.

FIG. 15 is a second diagram illustrating a sweep state by a blade.

FIG. 16 is a diagram showing a sweeping state by a blade according to a fifth embodiment of the present invention.

[Explanation of symbols]

 31, 71 Orifice plate 21 Prototype 23, 35 Concave part 24 Ink pressurizing chamber 25, 61 Pre-formed hole 32, 63, 73 Orifice 33, 55, 72 Counterbore part 34, 54, 74 Water repellent layer 77 Blade P1, P2 Closed Department

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Hideyuki Kobayashi 4-11-11 Shibaura, Minato-ku, Tokyo Inside the company offshore data (72) Inventor Hiroyuki Ueki 4-11-22 Shibaura, Minato-ku, Tokyo Shares F-term in the company offshore data (reference) 2C057 AF93 AP02 AP13 AP23 AP45 AP60 AQ00 AQ03 BA03

Claims (10)

[Claims] 1. A preformed hole formed in a surface on the ink pressurizing chamber side, and (b) an ink pressurizing chamber side formed by performing laser processing. An orifice plate having an orifice communicating with a droplet discharge side. 2. The orifice plate according to claim 1, wherein a spot facing portion is formed around the orifice on the surface on the ink droplet ejection side. 3. The orifice plate according to claim 2, wherein the counterbore portion is formed in common for a plurality of orifices. 4. The orifice plate according to claim 3, wherein the longitudinal axis of the counterbore is swept over the orifice plate and is inclined with respect to the longitudinal axis of the blade made of an elastic member. 5. The orifice plate according to claim 1, wherein a water-repellent layer is formed on the surface on the ink droplet ejection side. 6. A preform hole having a predetermined depth is formed on a surface of the orifice plate on the side of the ink pressurizing chamber when forming a prototype of the orifice plate. An orifice, wherein the orifice is formed by removing the closed portion by performing laser processing on the prototype, and communicating the ink pressurizing chamber side and the ink droplet ejection side at the preformed hole. Plate manufacturing method. 7. The method for manufacturing an orifice plate according to claim 6, wherein a concave portion for forming a spot facing portion is formed around the orifice on the surface on the ink droplet ejection side when the prototype is formed. 8. The method for manufacturing an orifice plate according to claim 6, wherein a water-repellent layer is formed on a surface of the prototype on the ink droplet ejection side after the orifice is formed. 9. A method according to claim 9, wherein: after the ink pressurizing chamber side and the ink droplet discharge side are communicated with each other, a water-repellent layer is formed on the surface of the prototype on the ink droplet discharge side; The method for manufacturing an orifice plate according to claim 6, wherein a spot facing portion is formed by performing laser processing on the orifice plate. 10. The method for manufacturing an orifice plate according to claim 6, wherein the preformed hole has a columnar portion adjacent to a closing portion.