JPH11277756A - Ink-jet printing apparatus, printing head and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely remove dust such as ink scum or paper dust, etc., from the inside of a nozzle crater and prevent dust from the outside of the nozzle crater from entering the nozzle crater when a surface of a nozzle plate of an ink-jet printing head is wiped. SOLUTION: A nozzle plate surface 23 has strip-like nozzle craters 27 recessed by approximately 5-10 μm from a main surface 25. An array of ink-jet outlets 31 is arranged in the nozzle crater 27. The nozzle crater 27 has an inclined face 33 inclined to the main surface 25 at a side part at the downstream side in a wiping direction. Moreover, trap grooves 39 recessed perpendicularly from the main surface 25 are formed along the nozzle crater 27 outside the nozzle crater 27. In wiping with the use of a rubber blade, the blade sweeps out the dust in the nozzle crater 27 through the inclined face 33. The dust scraped by the blade is trapped at the trap grooves 39.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an ink jet printing apparatus and a print head, and more particularly to an improvement in a surface structure of a nozzle plate.

[0002]

2. Description of the Related Art In an ink jet print head, dust such as ink residue and paper powder tends to adhere to a nozzle plate surface where nozzle outlets are arranged. Therefore, in order to remove such dust and prevent clogging of the nozzle, an wiper blade made of an elastic material is often pressed against the surface of the nozzle plate and rubbed (hereinafter, referred to as “wiping”).

Further, as shown in FIGS. 1 and 2, the nozzle outlet 1 is worn by contact with the printing paper,
In order to prevent the water-repellent layer 3 applied around the nozzle plate from being worn out, a region 9 called a “nozzle crater” which is recessed by about 5 to 10 μm from the surrounding region 7 is formed on the nozzle plate surface 5. The nozzle outlet 1 is arranged in the nozzle crater 9.

[0004]

As shown in FIGS. 1 and 2, even when wiping is performed by the blade 11, dust 15 remains in the nozzle crater 9, particularly near the edge 13 on the downstream side in the wiping direction. There's a problem. The main reason is that when the blade 11 leaves the nozzle crater 9, the dust 15 collected by the blade 11 is scraped (trapped) by the edge 13 of the crater 9 and
This is because they will be separated.

Conventionally, dust collected by the blade 11 in the area of the nozzle plate surface 5 in front of the nozzle crater 9 enters the nozzle crater 9 and becomes the edge of the crater 9 as described above. There is also a problem that it accumulates near 13.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to reliably remove dust from inside a nozzle crater when wiping a nozzle plate surface.

It is another object of the present invention to prevent dust scraped by the wiper blade from entering the nozzle crater when wiping the surface of the nozzle plate.

It is still another object of the present invention to prevent dust collected by the wiper blade from reaching other areas in wiping the nozzle plate surface.

It is yet another object of the present invention to be able to remove (refresh) dust from the wiper blade during wiping.

[0010]

In the ink jet printing apparatus and the ink jet print head according to the first aspect of the present invention, the nozzle crater on the surface of the nozzle plate is inclined on the downstream side in the wiping direction with respect to the main surface. It has an inclined surface. When the blade comes out of the nozzle crater by wiping, the blade climbs the inclined surface while catching the raked dust and sweeps the dust out of the nozzle crater.

In the ink jet printing apparatus and the ink jet print head according to the second aspect of the present invention, the edge of the nozzle crater on the downstream side in the wiping direction is obtuse or rounded. When the blade comes out of the nozzle crater by wiping, the dust collected by the wiper blade is hardly trapped at the obtuse angle or the rounded edge of the nozzle crater, and thus is well swept out of the nozzle crater.

In the ink jet printing apparatus and the ink jet print head according to the third aspect of the present invention, a trap groove for easily trapping dust is disposed at a position upstream or downstream of the nozzle crater in the wiping direction. When there is a trap groove on the upstream side, dust raked by the wiper blade on the upstream side is trapped in the trap groove, so that the blade is refreshed and dust hardly enters the nozzle crater. If there is a trap groove on the downstream side, dust scraped from the nozzle crater is trapped in the trap groove, the blade is refreshed, and the dust does not reach the downstream side. The dust entering the trap groove can be easily removed by an ink suction operation performed by placing a cap on the nozzle plate.

It is desirable that the trap groove extends in a direction perpendicular to the wiping direction over a range covering the existing range of the nozzle crater. Alternatively, it is also desirable to arrange the plurality of trap grooves in a direction perpendicular to the wiping direction over a range covering the existing range of the nozzle crater.

[0014] A method of manufacturing an ink jet print head according to a fourth aspect of the present invention includes a step of making a hole in a film and a step of joining the holed film to a surface of a nozzle plate. In the process of making holes in the film,
A hole is formed in a region of the nozzle plate surface covering the nozzle outlet, and an inclined surface is formed on a side portion of the hole. Thereby, it is possible to form the nozzle plate surface of the ink jet print head having the configuration according to the above-described first side surface or the second side surface.

According to a fifth aspect of the present invention, there is provided a method of manufacturing an ink jet print head, comprising the steps of forming a resist layer in a region covering a nozzle outlet on the surface of a nozzle plate, and thereafter, electroforming plating on the nozzle plate surface. The method includes a step of growing the metal layer higher than the resist layer, and a step of subsequently removing the resist layer. In the electroforming plating step, since the metal layer grows to have a curved inclined surface at the edge of the resist layer, the surface of the nozzle plate of the inkjet print head according to the above-described first side surface or the second side surface is cleaned. Can be formed.

[0016]

FIG. 3 is a plan view of a nozzle plate of an ink jet print head according to an embodiment of the present invention, and FIG. 4 is a sectional view of the nozzle plate.

The surface 23 of the nozzle plate 21 is 5 to 10 μm thicker than other regions (hereinafter referred to as “main surfaces”) 25.
A nozzle crater 27 which is slightly concave is formed. Each of the nozzle craters 27 has a rectangular planar shape, and outlets 31 of a number of ink jet nozzles 29 are arranged on a bottom surface 28 in a line along the longitudinal direction of the nozzle crater 27.

Each nozzle crater 27 has an inclined surface 33 that is gently inclined with respect to the main surface 25 on the downstream side in the wiping direction. Therefore, the downstream edge 35 of each of the nozzle craters 27 formed at the intersection of the inclined surface 33 and the main surface 25 has an obtuse angle, not a right angle as in the related art, so that dust is removed. It is hard to be trapped. On the other hand, the side of each nozzle crater 27 on the upstream side in the wiping direction is the main surface 25 in this embodiment.
However, the upstream side may have an inclined surface similar to that of the downstream side, and the edge 37 may have an obtuse angle, especially when wiping is performed in both directions. Should.

At locations close to the respective nozzle craters 27 on the upstream and downstream sides of the respective nozzle craters 27,
Two elongated trap grooves 39 are formed. Each trap groove 39 extends along the nozzle crater 27 over a range slightly longer than the entire length of the nozzle crater 27. Both the upstream and downstream sides of each trap groove 39 in the wiping direction are vertical walls cut off from the main surface 25 at right angles. Therefore, both edges 41 and 43 of each trap groove 39 formed at the intersection of the vertical wall and the main surface 25 have a cross-sectional angle of 90 degrees, and dust is easily trapped at the edges 41 and 43. Has become.

The nozzle plate surface 23 having such a structure
Is wiped with a blade 45 made of an elastic material such as rubber or foamed resin. As shown in FIG.
7, most of the dust 47 is trapped at the edge 43 of the trap groove 39 on the upstream side of the nozzle crater 27 and accumulates in the trap groove 39. The blade 45 is thus refreshed, and subsequently the nozzle crater 2
Go inside 7. Therefore, the dust 47 on the main surface 25 hardly enters the nozzle crater 27. Subsequently, the blade 45 rakes up the dust 49 from inside the nozzle crater 27, and climbs the inclined surface 33 while catching the dust 49,
The dust 47 is swept out of the nozzle crater 27. The dust 49 is trapped in the trap groove 39 on the downstream side of the nozzle crater 27. The above wiping operation is performed for each nozzle crater 27. The dust trapped in the trap groove 39 is later removed by covering the nozzle plate surface 23 with a rubber cap or the like and performing vacuum suction.

As described above, since the nozzle crater 27 has the inclined surface 33, dust 49 in the nozzle crater 27 can be satisfactorily swept out of the nozzle crater 27. Slope 3
The principle of the action of 3 is that firstly, the surface of the inclined surface 33 can keep good contact with the tip of the blade 45,
In addition, it is considered that the edge 35 of the nozzle crater 27 becomes dull and dust easily passes therethrough. Focusing on these two principles individually, the cross-sectional shape of the nozzle crater 27 does not necessarily have to be the same as that in FIG. 4, and various modifications can be considered. For example, as shown in FIG.
3 may be curved in a concave shape, or as shown in FIG. 6, the inclined surface 33 may be curved in a convex shape (in an extreme case, the edge is simply rounded (rounded)). Alternatively, as shown in FIG. 7, the inclined surface 33 does not rise directly from the bottom surface 28 of the nozzle crater 27, but rather extends from the bottom surface 28 through a slight vertical wall 51, as shown in FIG. It may be. Even in such a modified example, a good dust sweeping effect can be expected as compared with the conventional one, apart from the magnitude of the effect.

As described above, the trap groove 39 serves to trap dust and refresh the blade 45 and prevent dust from going to the nozzle crater 27 and other places. Several variations of the trap groove 39 are also conceivable. For example, as shown in FIG. 8, a larger number of trap grooves 39 may be provided than in the embodiment shown in FIGS. Conversely, for example, when the number of the trap grooves 39 between the two nozzle craters 27 is only one, or when wiping is performed only in one direction, the trap groove 39 downstream of the nozzle crater 27 on the most downstream side is omitted. For example, the number of trap grooves 39 may be further reduced.
Further, as shown in FIG. 9, the trap groove 39 having a shorter length than the nozzle crater 27, or as shown in FIG.
A plurality of trap grooves 39 having a shape suitable for being called a “hole” rather than a “groove” may be arranged along the longitudinal direction of the nozzle crater 27 (that is, a direction perpendicular to the wiping direction). 9 and 10, a plurality of trap grooves 39 are staggered so as to overlap each other in the longitudinal direction of the nozzle crater 27 so that the entire length of the nozzle crater 27 is always covered by any one of the trap grooves 39. It is preferable to arrange them in a shape. FIG.
The trap groove 39 may be designed in a meandering shape or another shape as shown in FIG.

The inclined surface 33 of the nozzle crater 27 and the trap groove 39 do not necessarily have to be combined, and the respective effects are exhibited even when used alone.

Next, an embodiment of a method for manufacturing the nozzle plate surface 23 having the above-described structure will be described.

FIG. 12 shows an embodiment of a manufacturing method by a laminating method. That is, the nozzle plate 21
A holed film 61 is joined to the originally plain surface by, for example, a press method. The hole of the film 61 is formed at a position covering the location of the nozzle crater 27 and the trap groove 37.
An inclined surface 33 is formed on the side of the hole 7.

FIGS. 13 to 20 show an embodiment of a manufacturing method by electroforming plating (electroplating).

First, as shown in FIG. 13, a thin ultraviolet-curing film (UV film) 61 is transferred onto the originally plane surface of the nozzle plate 21. Next, as shown in FIG. 14, portions 65 and 6 of the UV film 61 corresponding to the nozzle craters and the trap grooves are passed through a mask 63 having holes at positions corresponding to the nozzle craters and the trap grooves.
Only 7 is exposed to ultraviolet light. Next, as shown in FIG. 15, a non-cured portion of the UV film is removed by performing a developing process, so that only the portions 65 and 67 corresponding to the nozzle crater and the trap groove remain as a resist layer. Next, as shown in FIG. 16, the remaining resist layers 65, 67
Then, another slightly thick UV film 69 is transferred onto the second UV film 69, and only the portion 73 corresponding to the trap groove of the second UV film 69 is passed through the mask 71 having a hole only at the position corresponding to the trap groove. Exposure with ultraviolet light. next,
As shown in FIG. 17, development is performed to remove the uncured portion of the second UV film, and the portion 7 corresponding to the trap groove is formed.
Only 3 is left as a resist layer. As a result, a low-height resist layer 65 is formed on the surface of the portion corresponding to the nozzle crater of the nozzle plate 21, and a high-height resist layer 75 is formed on the surface of the portion corresponding to the trap groove.

Next, as shown in FIG. 18, a metal layer 77 of, for example, nickel is grown on the surface of the nozzle plate 21 by electroforming plating. The metal layer 77 is grown to a height higher than the resist layer 65 corresponding to the nozzle crater and lower than the resist layer 75 corresponding to the trap groove. Since the metal layer 77 grows in the direction of the electric field in the electroforming plating method, the metal layer 77 forms a curved or inclined outer surface near the edge of the resist layer 65 corresponding to the nozzle crater as shown in the drawing. So that this grows
The inclined surface 33 of the nozzle crater 27 is formed. On the other hand, the periphery of the resist layer 75 corresponding to the trap groove is completely filled with the metal layer 77.

Next, as shown in FIG.
5, 75 are removed. Next, as shown in FIG. 20, a thin water-repellent treatment layer 79 (for example, a mixture of nickel and Teflon) is formed on the entire surface by a plating method.
Thus, the nozzle crater 27 and the trap groove 39 having the above-described shapes are completed.

Although the embodiments of the present invention have been described above, these embodiments are merely examples for describing the present invention, and are not intended to limit the present invention only to these embodiments. Therefore, the present invention can be implemented in various forms other than the above-described embodiment.

[Brief description of the drawings]

FIG. 1 is a plan view of a nozzle plate of a conventional inkjet print head.

FIG. 2 is a sectional view of the nozzle plate taken along line AA of FIG. 1;

FIG. 3 is a plan view of a nozzle plate of the inkjet print head according to one embodiment of the present invention.

FIG. 4 is a sectional view of the nozzle plate taken along line BB of FIG. 3;

FIG. 5 is a sectional view of a nozzle plate according to a first modification.

FIG. 6 is a sectional view of a nozzle plate according to a second modification.

FIG. 7 is a sectional view of a nozzle plate according to a third modification.

FIG. 8 is a plan view of a nozzle plate according to a fourth modification.

FIG. 9 is a plan view of a nozzle plate according to a fifth modification.

FIG. 10 is a plan view of a nozzle plate according to a sixth modification.

FIG. 11 is a plan view of a nozzle plate according to a seventh modification.

FIG. 12 is a sectional view illustrating a first embodiment of the manufacturing method of the present invention.

FIG. 13 is a cross-sectional view illustrating a UV film transfer step according to a second embodiment of the manufacturing method of the present invention.

FIG. 14 is a cross-sectional view illustrating a first exposure step of the second embodiment of the manufacturing method of the present invention.

FIG. 15 is a cross-sectional view illustrating a first developing step of the second embodiment of the manufacturing method of the present invention.

FIG. 16 is a cross-sectional view illustrating a UV film retransfer and a second exposure step according to a second embodiment of the manufacturing method of the present invention.

FIG. 17 is a cross-sectional view explaining a second developing step of the second embodiment of the manufacturing method of the present invention.

FIG. 18 is a cross-sectional view illustrating an electroforming plating step according to the second embodiment of the manufacturing method of the present invention.

FIG. 19 is a sectional view for explaining a resist removing step of the second embodiment of the manufacturing method of the present invention.

FIG. 20 is a cross-sectional view illustrating a water-repellent treatment layer plating step of the second embodiment of the manufacturing method of the present invention.

[Explanation of symbols]

 21 Nozzle Plate 23 Nozzle Plate Surface 25 Nozzle Plate Main Surface 27 Nozzle Crater 29 Nozzle 31 Nozzle Exit 33 Nozzle Crater Sloping Surface 35, 37 Nozzle Crater Edge 39 Trap Groove 41, 43 Trap Groove Edge 45 Wiping Blade

Claims (12)

[Claims] 1. A nozzle plate having a surface on which an outlet of an ink jet nozzle is disposed, and a mechanism for wiping the surface of the nozzle plate, wherein the surface of the nozzle plate is recessed from the main surface and the main surface. A nozzle crater in which the nozzle outlet is disposed in the area, and the nozzle crater has an inclined surface inclined with respect to the main surface on a side portion on the downstream side in the wiping direction. Inkjet printing equipment. 2. The ink jet printing apparatus according to claim 1, wherein the nozzle crater has another inclined surface that is inclined with respect to the main surface also at a side portion on the upstream side of wiping. 3. The ink jet printing according to claim 1, wherein the surface of the nozzle plate further has a trap groove arranged at least one of a position upstream and a position downstream of the nozzle crater in the wiping direction. apparatus. 4. The ink jet printing apparatus according to claim 3, wherein the trap groove extends in a direction perpendicular to the wiping direction over a range covering an existing range of the nozzle crater. 5. A plurality of said trap grooves are arranged in a direction perpendicular to said wiping direction over a range covering an existing range of said nozzle crater.
An inkjet printing apparatus as described in the above. 6. A nozzle plate having a surface on which an outlet of an ink jet nozzle is arranged, and a mechanism for wiping the surface of the nozzle plate, wherein the surface of the nozzle plate is recessed from the main surface and the main surface. A nozzle crater in which the nozzle outlet is disposed in the region, wherein an edge of the nozzle crater on the downstream side in the wiping direction is obtuse or rounded. 7. A nozzle plate having a surface on which an outlet of an ink jet nozzle is arranged, and a mechanism for wiping the surface of the nozzle plate, wherein the surface of the nozzle plate is recessed from the main surface and the main surface. A nozzle crater in which the nozzle outlet is disposed in the region, and a trap groove disposed in at least one of a position on the upstream side and a position on the downstream side in the wiping direction with respect to the nozzle crater. Ink jet printing device. 8. A nozzle plate having a surface on which an outlet of an ink jet nozzle is arranged and capable of wiping the surface in a predetermined direction, wherein the surface of the nozzle plate has a main surface and a recess from the main surface. A nozzle crater in which the nozzle outlet is arranged in this area, and the nozzle crater has an inclined surface inclined with respect to the main surface at a side portion on the downstream side in the wiping direction. Inkjet print head. 9. A nozzle plate having a surface on which an outlet of an ink jet nozzle is arranged, the nozzle plate being capable of wiping the surface in a predetermined direction, wherein the surface of the nozzle plate is recessed from the main surface and the main surface. A nozzle crater in which the nozzle outlet is disposed, wherein an edge of the nozzle crater on the downstream side in the wiping direction is obtuse or rounded. 10. A nozzle plate having a surface on which an outlet of an ink jet nozzle is arranged and capable of wiping the surface in a predetermined direction, wherein the surface of the nozzle plate is recessed from the main surface and the main surface. A nozzle crater in which the nozzle outlet is arranged in the area, and a trap groove arranged in at least one of a position on the upstream side and a position on the downstream side in the wiping direction with respect to the nozzle crater. There is an inkjet print head. 11. A step of perforating a film, and a step of joining the perforated film to a surface of a nozzle plate for an ink jet print head, wherein the step of perforating the film includes the step of forming the nozzle plate. Drill the hole in the area covering the nozzle outlet on the surface,
In addition, a method of manufacturing an ink jet print head, wherein an inclined surface inclined with respect to the surface of the film is formed at a side portion of the hole. 12. A step of forming a resist layer in a region covering a nozzle outlet on a surface of a nozzle plate for an ink jet print head; and forming a resist layer on the surface of the nozzle plate on which the resist layer is formed.
A method for manufacturing an ink jet print head, comprising: a step of growing a metal layer higher than the resist layer by electroforming plating; and a step of removing the resist layer after growing the metal layer.