JP3937207B2 - Ink jet print head and ink jet printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a print head of an inkjet printer, and more particularly to a print head structure in which ink is wiped from an ink discharge surface (nozzle surface) with a wiping blade.
[0002]
[Prior art]
2. Description of the Related Art Conventional ink jet printers include a wiping mechanism that wipes a flat nozzle surface with a wiper blade (hereinafter referred to as a wiper) as one of mechanisms for cleaning an ink discharge surface, that is, a nozzle surface of a print head. For the wiper, an elastic material such as rubber or a flexible material such as felt is used. FIG. 1 simply shows a conventional wiping process of a print head.
[0003]
The print head 1 and the wiper 3 are configured to move relative to each other. When the print head 1 moves in the direction of the arrow as shown in FIG. 6A, first, the tip of the wiper 3 hits the side surface of the print head 1 as shown in FIG. As shown in c), the tip of the wiper 3 is bent while wiping off the dirt on the nozzle surface 7, and eventually the tip of the wiper 3 comes out of the print head 1 as shown in FIG. Next, the print head 1 moves in the direction opposite to the arrow, and the wiper 3 wipes off the dirt on the nozzle surface 7 from the direction opposite to the previous time. This is repeated several times.
[0004]
[Problems to be solved by the invention]
However, as shown in FIG. 1 (a), when the wiping process is started, if the ink residue 5 wiped off in the previous process remains on the wiper 3, the wiper 3 as shown in FIG. 1 (b). When the ink hits the side surface of the print head 1, the ink residue 5 adheres to the side surface of the print head 1 as shown in FIG. Thereafter, as shown in FIG. 5C, the wiper 3 advances while wiping the ink residue 5 ′ on the nozzle surface 7, and finally, when the wiper 3 comes out of the print head 1 as shown in FIG. As a result of the bounce of 3, the wiped ink residue 5 'is scattered around.
[0005]
Further, the ink residue 5 attached to the side surface of the print head 1 may reattach to the wiper 3 in the next wiping process. In this case, since the wiper 3 wipes the nozzle surface 7 with the ink residue 5 attached, there is a possibility that a sufficient cleaning function cannot be exhibited.
[0006]
In addition, the ink residue 5 attached to the side surface of the print head 1 may hang down and stain the paper being printed. Further, since the side surface of the print head 1 is generally subjected to a rough surface finish, the ink residue 5 attached to the side surface of the print head 1 climbs up the side surface of the print head due to a capillary phenomenon and is disposed at the base of the head. There is also a risk of flowing into a circuit board.
[0007]
The present invention has been made in view of such circumstances, and an object of the present invention is to prevent ink scum adhering to the side surface of the print head from flowing or dripping to other portions by a wiper cleaning operation. Another object of the present invention is to provide a print head in which the ink residue adhering to the side surface of the print head is not reattached to the wiper and the ink residue adhering to the wiper is not scattered.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, an ink jet print head according to the present invention includes a front part of a print head that abuts before the wiper enters the nozzle surface, and a rear part of the print head that abuts after the wiper comes out of the nozzle surface. Alternatively, both are provided with an ink absorber made of felt or non-woven fabric . In at least one of the front and rear ink absorbers, a plurality of slits for carrying ink by capillarity from one end contacting the wiper to the other end are arranged in a row. Each slit is formed from one end to the other end desired on the nozzle surface, and the other end of each slit is formed to stop before the other end of the ink absorber.
[0009]
According to the present invention, the ink absorbers at the front and rear of the print head absorb and hold the ink residue adhering to the wiper, so that the ink residue travels along the side surface of the print head and wraps around the circuit board, or the wiper rebounds. The risk of ink splattering is reduced. Further, since the wiper is cleaned after the ink residue is removed, the cleaning effect is enhanced.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of an ink jet print head according to the present invention will be described in detail with reference to the drawings.
[0013]
FIG. 2 shows an inkjet print head and wiping mechanism according to an embodiment of the present invention.
[0014]
A blade-type wiper 23 made of an elastic material such as rubber or a flexible material such as felt is disposed in the vicinity of a predetermined position for cleaning the print head 11. When wiping is performed, the print head 11 reciprocates in the direction indicated by the arrow A relative to the wiper 23 so as to pass the position of the wiper 23. The wiper 23 is fixed to the tip of the wiper holder 21, and the height of the wiper 23 can change as indicated by an arrow B. Usually, the wiper 23 is at a low position, and even if the print head 11 passes the position of the wiper 23, the wiper 23 does not touch the print head 11. At the time of wiping, the wiper 23 is at a high position, and when the print head 11 passes the position of the wiper 23, the wiper 23 bends and wipes the nozzle surface 13 on the lower surface of the print head 11.
[0015]
Of the side surfaces surrounding the nozzle surface 13 of the print head 11, two surfaces perpendicular to the moving direction indicated by the arrow A (that is, the two surfaces that contact the wiper 23 when the print head 11 moves) Ink absorbers 15 and 17 made of a material that easily absorbs ink, such as porous resin, felt, or non-woven fabric, are attached to the front and rear surfaces 14 and 16, respectively. The ink absorbers 15 and 17 extend over the entire width of the front surface 14 and the rear surface 16 of the print head 11, and the height from the lower end in contact with the nozzle surface 13 of the front surface 14 and the rear surface 16 to the height position where the upper end of the wiper 23 reaches. It is provided over a wide range. In other words, the ink absorbers 15 and 17 are provided so as to cover regions of the front surface 14 and the rear surface 16 of the print head 11 that are in contact with the wiper 23. Therefore, the wiper 23 does not directly touch the front surface 14 and the rear surface 16 of the print head 11.
[0016]
A plurality of slits 19 are formed in each of the ink absorbers 15 and 17. These slits 19 are cut vertically upward from the lower end desired on the nozzle surfaces 13 of the ink absorbers 15 and 17, and are arranged over the entire width of the ink absorbers 15 and 17. The upper ends of the slits 19 stop before the upper ends of the ink absorbers 15 and 17, and therefore the upper ends of the ink absorbers 15 and 17 are connected over the entire width without being divided by the slits.
[0017]
FIG. 3 shows a wiping process of the print head 11.
[0018]
As shown in FIG. 5A, at the start of wiping, even if the ink residue 25 is attached to the wiper 23, the wiper 23 is first placed in front of the print head 11 as shown in FIG. The ink absorber 25 is absorbed by the ink absorber 15 by contacting the ink absorber 15 and rubbing the surface of the wiper 23 with the ink absorber 15.
[0019]
Since the ink residue 25 is absorbed by the ink absorber 15 in this way, the nozzle surface 13 can be wiped with a clean wiper 23 having no ink residue as shown in FIG. Therefore, a good cleaning effect is exhibited. The wiper 23 collects the ink residue 25 ′ while wiping the nozzle surface 13, and then rubs against the ink absorber 17 when detaching from the nozzle surface 13 as shown in FIG. 'Is absorbed by the ink absorber 17. Finally, as shown in FIG. 5E, when the wiper 23 moves away from the print head 11, it bounces, but since the ink residue 25 'has already been removed, there is no possibility that the ink residue 25' will scatter.
[0020]
Ink absorbed in the ink absorbers 15 and 17 in the above process is held in the ink absorbers 15 and 17, and thus may drop down or flow to the circuit board or the like along the side of the head. decrease. As shown in FIG. 2, since a plurality of longitudinal slits 19 are arranged over the entire width in the ink absorbers 15 and 17, these slits 19 cause ink to be absorbed into the ink absorbers 15 and 17 by capillary action. To spread throughout the world. That is, since the ink absorbers 15 and 17 are in contact with the wiper 23 mainly at the lower end portion or near the lower end, the ink is absorbed near the lower end portion or the lower end. The slit 19 effectively carries the ink upward from the lower end portion or the vicinity of the lower end using the capillary phenomenon. As a result, the ink is less likely to concentrate and accumulate locally on the ink absorbers 15 and 17 and diffuses throughout the ink absorbers 15 and 17, thereby improving the ink absorption capability and ink retention capability of the ink absorbers 15 and 17. .
[0021]
Below, with reference to FIGS. 4-11, some embodiment of the inkjet print head which attached the variation in the shape of the ink absorber is described.
[0022]
FIG. 4 shows ink absorbers 15 and 17 having a plurality of slits 19 in the vertical direction, the same as that shown in FIG. The slit 19 does not reach the upper ends of the ink absorbers 15 and 17, but this is because the ink oozes out from the upper ends of the ink absorbers 15 and 17 through the slits and travels to the upper circuit board through the side of the head. This is to prevent this.
[0023]
In the print head 31 shown in FIG. 5, a plurality of vertical slits 39 extend completely from the lower end to the upper end through the ink absorbers 35 and 37. In other words, the ink absorbers 35 and 37 are formed by arranging a plurality of separated columnar sub-ink absorbers 35 ′ and 37 ′ on the front and rear surfaces of the print head 31 over the entire width thereof through the slits 39 therebetween. It is configured by The slit 39 reaches the upper ends of the ink absorbers 35 and 37. If the ink absorbers 35 and 37 themselves have sufficiently good ink absorbability, the ink oozes out from the upper ends of the ink absorbers 15 and 17 through the slits. There is almost no worry of going around to the upper circuit board along the side of the head.
[0024]
The ink absorbers shown in FIG. 4 and FIG. 5 improve the ink absorption ability by the capillary action of the slits, so that the ink can be absorbed rapidly. Therefore, even if the time for which the wiper hits the ink absorber is short, the ink can be satisfactorily absorbed, so that it becomes easy to increase the wiping speed and shorten the cleaning time.
[0025]
The ink absorbers 45 and 47 shown in a cross-sectional view in FIG. 6 are provided with a plurality of grooves extending in the lateral direction or a plurality of concave and convex portions on the surface, particularly the front surface to which the wiper hits. In addition, the ink absorbers 55 and 57 shown in a cross-sectional view in FIG. 7 are provided with a plurality of grooves extending in the lateral direction or a plurality of concave and convex portions on the lower surface against which the wiper 23 contacts. In addition, the ink absorbers 65 and 67 shown in a cross-sectional view in FIG. 8 are provided with a plurality of grooves extending in the lateral direction or a plurality of concave and convex portions on both the front surface and the lower surface where the wiper 23 contacts. The ink absorbers 75 and 77 shown in the cross-sectional view of FIG. 9 are provided with a plurality of slits 79 having a V-shaped cross section extending in the lateral direction on the surface such as the front surface and the lower surface where the wiper 23 contacts. The plurality of grooves, the gaps between the plurality of uneven portions, or the plurality of slits improve the ink absorption capacity of the ink absorber, and the corners of the grooves, the uneven portions, or the slits scrape the ink from the wiper. Improve ability.
[0026]
As shown in FIG. 10A, the ink absorber 85 shown in FIG. 10 has a plurality of slits 86 extending in the lateral direction on the front surface against which the wiper hits. The outer frame surfaces 85a, 85b, 85c, and 85d are not projected on the outer frame surfaces 85a, 85b, 85c, and 85d. As shown in FIG. 7B (cross-sectional view taken along line BB in FIG. 6A), the slit 86 is deeply cut from the surface of the ink absorber 85 until it reaches the surface of the print head 81 on the back side. . The ink absorber 96 shown in FIG. 11 (FIG. 11B is a cross-sectional view taken along the line C-C in FIG. 11A) has a plurality of deep circular holes (rectangular holes) reaching the surface of the print head 81 on the front surface where the wiper hits. 96 may be worn. These deep slits and holes quickly trap the ink adhering to the wiper, and the ink is absorbed into the ink absorbers 85 and 95 after the trap. As a result, the ink removal from the wiper is performed faster than the ink absorption speed of the ink absorber, so that the wiping speed can be easily increased. In addition, the slits and holes have the effect of diffusing ink throughout the ink absorber due to the capillary phenomenon, thereby enhancing the ink absorption capability.
[0027]
Next, with reference to FIGS. 12-16, the variation of arrangement | positioning with respect to the print head of an ink absorber is demonstrated.
[0028]
In FIG. 12, ink absorbers 105 and 107 are arranged on both side surfaces (front surface and rear surface) of the print head 101. The lower surfaces of the ink absorbers 105 and 107 may be flush with the nozzle surface 103, may slightly protrude from the nozzle surface 103 within a range in which the wiper bends, or may slightly recede. In addition, even if the lower surfaces of the ink absorbers 105 and 107 are parallel to the nozzle surface 103, they may be slightly inclined within a range where the wiper bends.
[0029]
In the print head 111 of FIG. 13, ink absorbers 115 and 117 are embedded at positions on both sides of the nozzle 119 on the nozzle surface 113. In the print head 121 of FIG. 14, ink absorbers 125 and 127 are bonded to positions on both sides of the nozzle 129 on the nozzle surface 123. The lower surfaces of the ink absorbers 115, 117, 125, and 127 protrude from the nozzle surfaces 113 and 123. However, in the case of embedding in FIG.
[0030]
The print head 131 of FIG. 15 has ink absorbers 135 and 137 attached to support members 134 and 136 at locations slightly away from the front and rear surfaces.
[0031]
FIG. 16 shows a print head 141 for color printing, and ink absorbers on both sides of the print heads 141M, 141C, and 141Y for each color such as magenta (M), cyan (C), and yellow (Y). 145, 147, 149, 151 are arranged. In other words, not only the ink absorbers 145 and 151 are provided at the front and rear portions of the print head 141, but also nozzle rows of three colors M, C, and Y on the nozzle surfaces 143M, 143C, and 143Y (see FIG. Other ink absorbers 147 and 149 are also provided at positions between each other (not shown). Ink absorbers 147 and 149 that partition the print heads for each color (that is, partition the nozzle rows for each color) have a function of removing ink residue from the wiper, and ink adhering to the nozzle surface of each color head. It also has a function to prevent mixing with inks of different colors.
[0032]
The embodiment described above is an example for explaining the present invention, and the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the gist of the invention. For example, the shape of the ink absorber is not limited to those provided with slits, irregularities, holes, etc., as shown in FIGS. 4 to 11, and any shape that can effectively absorb the wiper ink, Various other shapes can be employed. Furthermore, the arrangement of the ink absorber is not limited to the arrangement shown in FIGS. 12 to 16, and the ink absorber can be arranged at any position as long as the ink adhering to the wiper can be effectively wiped off and absorbed. It doesn't matter. The shapes shown in FIGS. 4 to 11 can be combined and the arrangements shown in FIGS. 12 to 16 can be combined. Also, the ink absorber on the front surface of the print head and the ink absorber on the rear surface can be made different in shape and arrangement.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a wiping process of a conventional print head.
FIG. 2 is a perspective view of a print head and a wiper according to an embodiment of the present invention.
FIG. 3 is an explanatory diagram of a wiping process according to the embodiment.
FIG. 4 is a perspective view of an ink absorber according to the embodiment.
FIG. 5 is a perspective view of an ink absorber according to a second embodiment of the present invention.
FIG. 6 is a cross-sectional view of an ink absorber according to a third embodiment of the present invention.
FIG. 7 is a cross-sectional view of an ink absorber according to a fourth embodiment of the present invention.
FIG. 8 is a cross-sectional view of an ink absorber according to a fifth embodiment of the present invention.
FIG. 9 is a cross-sectional view of an ink absorber according to a sixth embodiment of the present invention.
FIG. 10 is a perspective view and a sectional view of an ink absorber according to a sixth embodiment of the present invention.
FIG. 11 is a perspective view and a cross-sectional view of an ink absorber according to a seventh embodiment of the present invention.
FIG. 12 is a cross-sectional view showing the arrangement of the ink absorber according to the first embodiment of the present invention.
FIG. 13 is a sectional view showing the arrangement of an ink absorber according to an eighth embodiment of the present invention.
FIG. 14 is a cross-sectional view showing the arrangement of an ink absorber according to a ninth embodiment of the present invention.
FIG. 15 is a sectional view showing the arrangement of an ink absorber according to a tenth embodiment of the present invention.
FIG. 16 is a cross-sectional view showing the arrangement of an ink absorber according to an eleventh embodiment of the present invention.
[Explanation of symbols]
11, 31, 41, 51, 61, 81, 91, 101, 111, 121, 131, 141 Print head 15, 17, 35, 37, 45, 47, 55, 57, 65, 67, 75, 77, 85 95, 105, 107, 115, 117, 125, 127, 135, 137, 145, 147, 149, 151 Ink absorber 23 Wiper 25, 25 'Ink residue 19, 39, 79, 86 Slit 96 Circular hole

Claims (1)

In an inkjet print head that is used in an inkjet printer and wipes the nozzle surface with a wiper during cleaning,
At least one of the front part of the print head that abuts before the wiper enters the nozzle surface and the rear part of the print head that abuts after the wiper comes out of the nozzle surface is from one end that abuts the wiper. A plurality of slits for carrying ink to the other end by capillary action are arranged across the entire width, and includes an ink absorber made of felt or non-woven fabric ,
Each slit is formed from one end to the other end desired on the nozzle surface, and the other end of each slit is formed to stop before the other end of the ink absorber. Inkjet print head.

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