JP3584772B2 - Ink jet recording device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a recording apparatus in which an ink jet recording head is mounted on a carriage that moves in the width direction of recording paper, and in particular, a hollow ink supply needle that derives ink in an ink cartridge and supplies ink to the recording head. The present invention relates to an ink jet recording apparatus capable of reducing the amount of air bubbles remaining between a recording medium and a filter member and performing stable supply of ink to a recording head.
[0002]
[Prior art]
2. Description of the Related Art Ink jet recording apparatuses have been used in many types of printing including color printing in recent years because noise during printing is relatively small and small dots can be formed with high density. Such an ink jet recording apparatus includes an ink jet recording head that receives supply of ink from an ink cartridge, and a paper feeding unit that moves recording paper relative to the recording head, and records the recording head on a carriage. Recording is performed by ejecting ink droplets onto the recording paper while moving in the width direction of the paper. The carriage is equipped with a recording head that can eject black ink and each color ink of yellow, cyan, and magenta, and not only text printing with black ink, but also full-color printing by changing the ejection ratio of each ink. It is possible.
[0003]
On the other hand, in this type of printing apparatus for consumer use, each of the ink cartridges enclosing the black ink and the color ink is configured to be detachably mountable from above on a carriage on which a printing head is mounted, Each cartridge is configured so that ink is supplied to the recording head via a hollow ink supply needle (hereinafter also referred to as a hollow needle) formed upward on the carriage.
[0004]
The ink supplied from the ink cartridge to the recording head is required to be in a clean state free of foreign matter such as dust. For this reason, the ink is supplied to the upstream side of the recording head in the ink flow path, for example, with the hollow needle. A filter member for removing foreign matter is arranged between the head case supporting the hollow needle.
[0005]
FIG. 14 schematically shows an example of the configuration. As shown in FIG. 14, a nozzle plate 7a is disposed on a lower surface of a head case 71 constituting the recording head 7, and a plurality of nozzle openings 7b are formed in the nozzle plate 7a. An actuator 7c such as a piezoelectric vibrator is arranged corresponding to 7b. An ink communication flow path 7d is formed in the head case 71 from the nozzle opening 7b and the actuator 7c to the upper part.
[0006]
On the upper part of the head case 71, four hollow needles 21 each having an ink introduction hole 21a are arranged in an upright state, and a flat filter is provided between the hollow needles 21 and the head case 71. A member 22 is arranged. The hollow portion of each hollow needle 21 is connected to each ink communication channel 7 d formed in the head case 71 via a filter member 22.
[0007]
The ink supply needle 21 at the left end in FIG. 14 is for supplying black ink, and is configured so that the black ink cartridge 8 can be loaded from above in the direction of arrow A toward the ink supply needle 21. I have. Most of the upper part of the black ink cartridge 8 forms an ink storage chamber 8a. The ink storage chamber 8a contains a porous member 8b, and the porous member 8b is impregnated with black ink. Ink is stored in the state.
[0008]
An opening 8c is formed in the lower portion of the ink storage chamber 8a, and a rubber sealing member 8d is fitted in the opening 8c. A film member 8e is attached to the lower end of the opening 8c, and is sealed so that the ink solvent inside does not volatilize during storage of the cartridge.
[0009]
When the cartridge 8 is pushed in the direction of arrow A as shown in FIG. 14, the ink supply needle 21 penetrates the film member 8e, and the rubber seal member 8d mounted on the cartridge 8 allows the ink supply needle The cartridge 8 is connected to the periphery of the cartridge 21 so as to be loaded. Then, ink is supplied from the ink cartridge 8 to the recording head side through an ink lead-out hole 21a formed at the tip of the ink supply needle 21.
[0010]
On the other hand, as shown in FIG. 14, the color ink cartridge 9 is formed with ink storage chambers for individually storing yellow, cyan, and magenta color inks, and these are integrally formed. This is the same as the above-described black ink cartridge 8, and therefore, detailed description of each configuration is omitted.
[0011]
Also in the color ink cartridge 9, when the color ink cartridge 9 is pushed in the direction of the arrow B shown in FIG. 14, the remaining three ink supply needles 21 established on the head case 71 are set in the loaded state, and each color ink is set in the recording head. It is made to be supplied to the side.
[0012]
FIG. 15 is a cross-sectional view showing the arrangement of a conventional ink supply needle and a filter member in which the above-described black ink cartridge is loaded, and portions corresponding to FIG. 14 are denoted by the same reference numerals. As shown in FIG. 15, the ink supply needle 21 into which the black ink cartridge 8 is loaded is disposed at the end of the head case 71. Therefore, the ink communication flow path 7d formed in the head case 71 Immediately below the member 22, the head case 71 is formed in a bent state toward the center of the head case 71 in a direction perpendicular to the surface of the filter member 22, in other words, in an L-shape.
[0013]
The filter member 22 is formed in an elliptical shape, and is disposed so that its major axis direction matches the direction in which the filter member 22 is bent in an L-shape. In this case, the gap portion 21b is formed in the bending direction of the ink communication flow path. With such a configuration, the flow of the ink can be guided in the L-shaped bending direction, and the area of the filter member can be increased to reduce the pressure loss (flow resistance of the ink) due to the filter member 22. It is made as follows.
[0014]
[Problems to be solved by the invention]
By the way, in a state where the hollow needle and the filter member are arranged in the direction of gravity as described above, at the time of initial filling when the recording head is filled with the ink for the first time, the space defined by the hollow needle 21 and the filter member 22 is formed. Then, a phenomenon occurs in which the bubbles Ai remain, and it is difficult to discharge the remaining bubbles Ai.
[0015]
On the other hand, in recent years, in order to increase the printing speed, the number of nozzles for ejecting ink has been increased, and the frequency of electric signals applied to an actuator for ejecting ink has been increased. For this reason, the consumption amount of the ink per unit time is rapidly increasing, and the flow velocity of the ink flowing in the hollow needle 21 is also increasing.
[0016]
Accordingly, the air bubbles Ai are attracted to the filter member 22 side by the flow of ink, and when the printing state is full duty (ink is ejected at the highest frequency from all the nozzle openings simultaneously), the filter member The phenomenon that the air bubbles Ai remaining on the upstream side of the filter 22 move to the upper part of the filter member 22 and remain flat at the upper part of the filter member 22 occurs.
[0017]
In particular, as described above, in the configuration in which the gap portion 21b is formed in the bending direction of the ink communication channel at the joint between the hollow portion of the ink supply needle 21 and the filter member 22, the bubbles Ai enter the gap portion 21b. At the same time, the air bubbles Ai are stuck to almost the entire surface of the filter member 22, and the effective area of the filter member 22 is reduced and the pressure loss is increased.
[0018]
When such a situation is reached, the supply of ink to the recording head side decreases, and the weight of the ink drops becomes smaller than a set value, thereby causing a problem of causing printing trouble. Further, in the worst case, there is a problem that the meniscus formed in the nozzle opening of the head is destroyed, and the ink from the nozzle opening becomes defective in ejection.
[0019]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional technical problem, and can reduce the amount of residual air bubbles existing on an upper portion of a filter member, and can reduce the amount of residual air bubbles generated during printing. An object of the present invention is to provide an ink jet recording apparatus which is configured so as to be able to suppress the sticking phenomenon to the ink jet recording apparatus, thereby eliminating the occurrence of the printing failure due to the influence of the residual air bubbles.
[0020]
[Means for Solving the Problems]
An ink jet recording apparatus according to the present invention, which has been made to achieve the above-described object, is mounted on a carriage that moves in the width direction of recording paper, and an ink jet recording head that ejects ink droplets from nozzle openings, A hollow ink supply needle that communicates with an ink cartridge that supplies ink to the recording head, derives ink in the cartridge, and supplies ink to the recording head; and a space between the hollow ink supply needle and the recording head. An ink-jet recording apparatus provided with a filter member for removing foreign matter, which is disposed in the ink supply path of the ink supply path, wherein a substantially central portion of the filter member disposed in a joined state in the hollow portion of the ink supply needle, The ink supply needle is formed so as to protrude toward the hollow portion side.
[0023]
Further, as another preferred embodiment, a substantially central portion of a filter member arranged in a joined state in a hollow portion of the ink supply needle may be formed so as to protrude toward an ink communication flow path to a recording head. . In this case, the protruding portion is formed in a groove shape in which the protruding amount increases from one side to the other, and the protruding lower end portion forms a guide groove located immediately above the ink communication flow path leading to the recording head. Is preferred.
[0026]
According to the ink jet recording apparatus configured as described above, the substantially central portion of the filter member arranged in a joined state to the hollow portion of the ink supply needle projects to the hollow portion side of the ink supply needle, Since the substantial area of the filter member can be increased, pressure loss due to the filter member can be reduced. Since the hemispherical projection occupies the space where the residual air bubbles are present on the upstream side of the filter member, the discharge of the air bubbles existing on the upstream side of the filter member during the initial filling operation can be promoted.
[0027]
Furthermore, the substantial area of the filter member is similarly increased by adopting a configuration in which a substantially central portion of the filter member which is arranged in the hollow portion of the ink supply needle and protrudes toward the ink communication flow path to the recording head. Pressure loss due to the filter member can be reduced. The protruding portion is formed in a groove shape in which the protruding amount increases from one side to the other, and the protruding lower end portion forms a guide groove located immediately above the ink communication flow path leading to the recording head, so that the ink is formed. During the initial filling operation, bubbles existing upstream of the filter member can be concentrated on the lower end of the guide groove and discharged.
[0028]
Therefore, in any of the above-described configurations, the amount of air bubbles remaining on the upstream side of the filter member can be effectively reduced, and a stable supply of ink to the printhead can be achieved during actual use of the printing apparatus. It can be performed.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an ink jet recording apparatus according to the present invention will be described based on an embodiment shown in the drawings. FIG. 1 is a perspective view showing a basic configuration of a recording apparatus main body to which the present invention is applied. In FIG. 1, reference numeral 1 denotes a carriage, which is guided by a guide member 4 via a timing belt 3 driven by a carriage motor 2 and reciprocates in the axial direction of a platen 5.
[0030]
An ink jet recording head 7 is mounted on the side of the carriage 1 facing the recording paper 6, and a black ink cartridge 8 for supplying ink to the recording head 7 and a color ink cartridge 9 are detachably mounted above the recording head 7. Loaded as possible.
[0031]
In the drawing, reference numeral 10 denotes capping means disposed in a non-printing area (home position), which is configured to seal the nozzle forming surface of the recording head 7 when the recording head 7 moves directly above. I have. A suction pump 11 for applying a negative pressure to the internal space of the capping unit 10 is disposed below the capping unit 10.
[0032]
The capping means 10 functions as a lid for preventing the nozzle opening of the recording head 7 from drying during the suspension period of the recording apparatus, and also applies a drive signal unrelated to printing to the recording head to discharge ink droplets idly. It functions as an ink receiver at the time of the flushing operation to be performed, and also has a function of executing a cleaning operation of sucking ink by applying a negative pressure from the suction pump 11 to the recording head 7. A wiping member 12 made of an elastic plate such as rubber is disposed near the capping unit 10, and wipes the nozzle forming surface of the recording head 7 when the carriage 1 reciprocates toward the capping unit 10. The wiping operation is performed.
[0033]
FIG. 2 shows a first embodiment in which the configuration of a portion including an ink supply needle for handling black ink and a filter member in the above-described printing apparatus is shown in a sectional view. This is drawn in a form corresponding to FIG. 15 described above, and portions corresponding to FIG. 15 are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0034]
In the embodiment shown in FIG. 2, the ink communication flow path 7d from the filter member 22 to the recording head is formed to be bent immediately below the filter member 22 in a direction perpendicular to the surface of the filter member. . A gap 21b is formed at the joint between the hollow portion of the ink supply needle 21 and the filter member 22 in the bending direction of the ink communication channel 7d. In this case, the gap portion 21b is formed with such a gap that the residual air bubbles Ai existing in the hollow ink supply needle 21 do not enter with the flow of the ink.
[0035]
According to the above-described configuration, the surface tension of the residual air bubbles Ai acts to prevent the residual air bubbles Ai from entering the gap 21b when the ink flows at the time of printing. Thereby, an effective area by the filter member 22 immediately below the gap portion 21b can be secured, and pressure loss by the filter member can be reduced.
[0036]
FIG. 3 shows a second embodiment in which the configuration of a portion including an ink supply needle and a filter member for handling black ink is similarly shown in a sectional view. This is also drawn in a form corresponding to FIG. 15 described above, and portions corresponding to FIG. 15 are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0037]
In the embodiment shown in FIG. 3, the gap portion 21b formed in the bending direction of the ink communication flow path 7d is formed to be narrower than that in the embodiment shown in FIG. Does not enter the gap 21b with the flow of the ink in the state of the flow velocity of the ink during printing. Thereby, an effective area by the filter member 22 immediately below the gap portion 21b can be secured, and pressure loss by the filter member can be reduced.
[0038]
In addition, in the configuration illustrated in FIG. 3, the gap portion 21 b is configured to be narrower than the configuration illustrated in FIG. 2. By the ink suction operation, the ink flows so as to be orthogonal to the surface of the filter member 22. Therefore, the discharge of the bubbles Ai existing on the upstream side of the filter member 22 is promoted, and the discharge of the residual bubbles Ai can be achieved to some extent. Therefore, the amount of the residual air bubbles Ai can be reduced, and the reduced residual air bubbles Ai are less likely to be dragged by the flow of the ink and reach the filter member 22. As shown in FIG. 3, the ink supply needle 21 stays in the middle of the internal space or is located further up.
[0039]
Next, FIG. 4 shows a third embodiment in which the configuration of a portion including an ink supply needle and a filter member for similarly handling black ink is shown in a sectional view. This is also drawn in a form corresponding to FIG. 15 described above, and portions corresponding to FIG. 15 are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0040]
In the embodiment shown in FIG. 4, a gap is formed in the bending direction of the ink communication flow path 7d at the joint between the hollow portion of the ink supply needle 21 and the filter member 22 as compared with the embodiment shown in FIG. Not configured. According to the embodiment shown in FIG. 4, since the gap 21b does not exist as shown in FIG. 2 or 3, the area of the filter member 22 is substantially reduced, so that the ink flow during the initial filling operation is reduced. It gets even faster.
[0041]
Therefore, the discharge of the bubbles Ai existing on the upstream side of the filter member 22 is further promoted, and the amount of the remaining bubbles Ai can be reduced. Accordingly, the frequency of the reduced residual bubbles Ai being dragged by the flow of the ink and reaching the filter member 22 is reduced, and in the normal printing state, as shown in FIG. Or stay further up.
[0042]
FIGS. 5 to 7 show fourth to sixth embodiments in which the configuration of a portion including an ink supply needle and a filter member for handling black ink is similarly shown in cross-sectional views. These embodiments are also drawn in a form corresponding to FIG. 15 described above, and portions corresponding to FIG. 15 are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0043]
In each of the embodiments shown in FIGS. 5 to 7, the ink communication flow path 7d from the filter member 22 to the recording head is formed immediately below the filter member 22 in a direction orthogonal to the surface of the filter member. . According to this configuration, the ink communication flow path 7d reaching the recording head is orthogonal to the surface of the filter member 22, and therefore, pressure is evenly applied to the filter member 22. The discharge of the bubbles Ai existing on the upstream side of the member 22 is promoted. Further, since the flow of the ink is formed in a direction orthogonal to the filter member 22, the discharge of the bubbles Ai existing on the upstream side of the filter member 22 is similarly promoted.
[0044]
As a result, the frequency of the reduced residual air bubbles Ai being dragged by the flow of the ink and reaching the filter member 22 is also reduced, and in the normal printing state, the ink supply needles 21 as shown in FIGS. Either stay in the middle of the interior space or be located further up.
[0045]
In the embodiment shown in FIG. 5, a gap portion 21b similar to the embodiment shown in FIG. 2 is formed, and in the embodiment shown in FIG. 6, a gap portion 21b similar to the embodiment shown in FIG. Is formed. According to the embodiments shown in FIGS. 5 and 6, even if the air bubbles Ai reach the filter member 22 due to the flow of the ink, the air bubbles do not enter the gap portion 21b due to the surface tension of the air bubbles. The effective area of the filter member 22 immediately below the filter member can be secured, and the pressure loss due to the filter member can be reduced.
[0046]
FIG. 8 shows a seventh embodiment in which the configuration of a portion including an ink supply needle and a filter member that also handle black ink is shown in a sectional view. This is also drawn in a form corresponding to FIG. 15 described above, and portions corresponding to FIG. 15 are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0047]
In the embodiment shown in FIG. 8, a part of the filter member 22 arranged in a joined state in the hollow portion of the ink supply needle 21 is formed so as to protrude toward the hollow portion side of the ink supply needle 21. . In the embodiment shown in FIG. 8, the projection 22a is configured to be substantially hemispherical. By forming the hemispherical protruding portion 22a, the substantial area can be increased as compared with a flat filter member, so that pressure loss due to the filter member can be reduced. In addition, since the hemispherical protrusion 22a occupies the space where the residual air bubbles are present on the upstream side of the filter member 22, the discharge of the air bubbles Ai existing on the upstream side of the filter member 22 during the initial ink filling operation is performed. Can be promoted.
[0048]
Furthermore, the hemispherical projection 22a can prevent sticking of the residual air bubbles Ai due to the flow of the ink, and has a synergistic effect with the above-described effect of reducing the pressure loss due to the increase in the substantial area. Failure can be effectively prevented.
[0049]
Although the embodiment shown in FIG. 8 shows an example in which a hemispherical projection 22a is formed on an elliptical filter member, for example, as shown in a perspective view in FIG. Similarly, a hemispherical protrusion 22a may be formed at the center of the ink supply needle 22 toward the hollow side of the ink supply needle 22.
[0050]
Next, FIG. 10 shows another embodiment in which the configuration of a portion including an ink supply needle and a filter member which also handle black ink is shown in a sectional view. This is also drawn in a form corresponding to FIG. 15 described above, and portions corresponding to FIG. 15 are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0051]
In the embodiment shown in FIG. 10, a part of the filter member 22 arranged in a joined state in the hollow portion of the ink supply needle 21 is formed so as to protrude toward the ink communication flow path to the recording head. . FIGS. 11A and 11B show a top view of the filter member 22 as viewed from above and a side view as viewed from the horizontal direction. The filter member 22 is formed in an elliptical shape when viewed from above, and a substantially central portion of the filter member 22 is formed so as to protrude toward the ink communication flow path 7d reaching the recording head. The protruding portion is formed in a groove shape in which the protruding amount increases from one side to the other, and the protruding lower end portion 22b forms a guiding groove 22c located immediately above the ink communication flow path 7d reaching the recording head.
[0052]
According to this configuration, the substantial area thereof can be increased as compared with a flat filter member, so that the pressure loss due to the filter member can be reduced. Further, since the protruding lower end portion 22b of the guide groove 22c is formed just above the ink communication flow path 7d reaching the recording head, the lower end portion 22b is located upstream of the filter member 22 during the initial ink filling operation. Since the generated bubbles are guided from the guide groove 22c to the protruding lower end portion 22b, the discharge of the bubbles can be promoted.
[0053]
Further, the guide groove 22c protruding toward the ink communication flow path 7d can prevent sticking of residual air bubbles due to the flow of ink when the recording apparatus is actually used, and can reduce the pressure loss due to the increase in the substantial area described above. By the synergistic effect with the reduction effect, it is possible to effectively prevent the occurrence of the trouble due to the residual bubbles.
[0054]
The filter member shown in FIG. 12 shows a modification of the configuration shown in FIG. The filter member shown in FIG. 12 has a configuration in which a filter forming portion (effective area portion of the filter) is approximately an isosceles triangle when viewed from above in the configuration shown in FIG. Therefore, during the initial ink filling operation, the air bubbles existing upstream of the filter member 22 can be concentrated just above the ink communication flow path 7d leading to the recording head, thereby further improving the air bubble discharging efficiency. it can.
[0055]
Note that the configurations shown in FIGS. 11 and 12 have a configuration in which the long-side guide groove 22c whose protrusion amount increases from one side to the other side is protruded toward the ink communication flow path to the recording head. For example, as shown in the perspective view of FIG. 13, a hemispherical protruding portion 22d may be formed at the center of the circular filter member 22 so as to protrude toward the ink communication flow path leading to the recording head. , The substantial area of the filter can be increased, and the pressure loss due to the filter member can be similarly reduced.
[0056]
【The invention's effect】
As is apparent from the above description, according to the ink jet recording apparatus of the present invention, it is possible to secure an effective area by the filter member and reduce the pressure loss by the filter member. Further, since the discharge of bubbles existing upstream of the filter member can be promoted in the initial filling operation of the ink, bubbles remaining on the upstream side of the filter member may cause printing defects during actual use of the recording apparatus. Problem can be solved. This makes it possible to provide an ink jet recording apparatus that can guarantee a stable printing operation.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a basic configuration of an ink jet recording apparatus main body to which the present invention is applied.
FIG. 2 is a cross-sectional view illustrating a first embodiment of a configuration of an ink supply needle and a filter member in the recording apparatus illustrated in FIG.
FIG. 3 is a sectional view showing a second embodiment.
FIG. 4 is a cross-sectional view showing a third embodiment.
FIG. 5 is a cross-sectional view showing a fourth embodiment.
FIG. 6 is a sectional view showing a fifth embodiment.
FIG. 7 is a sectional view showing a sixth embodiment.
FIG. 8 is a sectional view showing a seventh embodiment of the present invention.
FIG. 9 is a perspective view of an ink supply needle and a filter member according to an eighth embodiment.
FIG. 10 is a sectional view showing a ninth embodiment in the same manner.
11 is a configuration diagram of a filter member used in the embodiment shown in FIG.
FIG. 12 is a configuration diagram of another filter member used in the embodiment shown in FIG.
FIG. 13 is a perspective view showing another embodiment of the ink supply needle and the filter member.
FIG. 14 is a schematic diagram illustrating a state in which an ink cartridge for supplying ink to a recording head is loaded.
FIG. 15 is a cross-sectional view showing an arrangement of a conventional ink supply needle and a filter member in which a black ink cartridge is loaded.
[Explanation of symbols]
Reference Signs List 1 carriage 6 recording paper 7 ink jet recording head 7a nozzle plate 7b nozzle opening 7d ink communication channel 8 black ink cartridge 9 color ink cartridge 10 capping means 11 suction pump 12 wiping member 21 ink supply needle 21a ink introduction hole 21b gap Part 22 Filter member 22a Hemispheric projection 22b Projection lower end 22c Guide groove 22d Hemisphere projection 71 Head case Ai Residual air bubbles

Claims (3)

An ink jet recording head that is mounted on a carriage that moves in the width direction of the recording paper and ejects ink droplets from nozzle openings, and communicates with an ink cartridge that supplies ink to the recording head. An ink jet printer comprising: a hollow ink supply needle that supplies ink to the recording head; and a filter member that is disposed in an ink supply path between the hollow ink supply needle and the recording head and removes foreign matter. An expression recording device,
An ink jet recording apparatus, characterized in that a substantially central portion of a filter member arranged in a joined state in the hollow portion of the ink supply needle is formed so as to protrude toward the hollow portion side of the ink supply needle. An ink jet recording head that is mounted on a carriage that moves in the width direction of the recording paper and ejects ink droplets from nozzle openings, and communicates with an ink cartridge that supplies ink to the recording head. An ink jet printer comprising: a hollow ink supply needle that supplies ink to the recording head; and a filter member that is disposed in an ink supply path between the hollow ink supply needle and the recording head and removes foreign matter. An expression recording device,
An ink jet recording apparatus, wherein a substantially central portion of a filter member joined to a hollow portion of the ink supply needle is formed so as to protrude toward an ink communication channel leading to a recording head. The projecting portion formed on the filter member is formed in a groove shape in which the projecting amount increases from one side to the other, and the projecting lower end has a guide groove located immediately above the ink communication flow path leading to the recording head. The ink jet recording apparatus according to claim 2 formed.

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