JP3598777B2 - Recording device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink jet recording apparatus that forms an image by discharging ink from nozzles.
[0002]
[Prior art]
2. Description of the Related Art In recent years, a recording apparatus that performs recording using liquid ink has been developed in which an ink tank that supplies ink to a print head is detachably configured. In such an apparatus, ink can be replenished by replacing only the ink tank. The ink tank to be replaced can be manufactured at low cost, and the running cost of the recording apparatus can be reduced.
[0003]
In such a configuration using a detachable ink tank, a filter is used on the ink tank side at the connection portion between the print head and the ink tank in order to prevent ink leakage or the like. A filter is mounted so that dust and the like do not enter the print head when the tank is removed.
[0004]
For example, in a recording apparatus described in JP-A-6-71900, a first filter is provided at an ink inlet of a print head, and a second filter is provided at an ink supply port of an ink tank. At this time, the mesh size of the first filter is larger than the mesh size of the second filter. With this configuration, air bubbles remaining in the ink flow path when the ink tank is mounted on the print head are guided to the print head side, thereby preventing air bubbles from entering the ink tank. Air bubbles that have entered the print head side are removed from the nozzle side of the print head by, for example, ink suction during maintenance. However, the ink may not be sufficiently removed, and if bubbles remain in the ink flow path, an image defect or the like due to a defective ink ejection may occur.
[0005]
For example, in Japanese Patent Application Laid-Open Nos. Hei 8-224848 and Hei 8-207298, contrary to the above-mentioned documents, bubbles remaining in the ink flow path when the ink tank is mounted on the print head are directed to the ink tank side. There is a statement that the print head side will not be guided. Although these documents do not describe filter conditions, etc., if the mesh size of the filter on the ink inlet side of the print head is made smaller than the mesh size of the filter on the ink supply side of the ink tank, the connection portion It is considered that the bubbles remaining in the ink tank move to the ink tank side. As a result, the amount of bubbles entering the print head is drastically reduced, and ejection failure due to bubbles can be reduced.
[0006]
These filters also have a function of removing foreign matter in the ink tank and preventing foreign matter from entering the print head. FIG. 8 is an explanatory diagram of an example of the relationship between the filtration particle size of the filter and the transmission efficiency. FIG. 8 shows the degree to which a 10 μm, 20 μm, 30 μm, and 40 μm foreign matter is transmitted through a tatami twill filter having a mesh size of 12 μm, 13 μm, and 38 μm, respectively. For example, in a tatami twill filter having a mesh size of 12 μm, foreign matter having a size of 40 μm hardly transmits, foreign matter having a size of 30 μm transmits 3%, foreign matter having a size of 20 μm transmits 10%, and foreign matter having a size of 10 μm transmits 55%. Similarly, in a tatami twill filter having a mesh size of 38 μm, foreign substances of 40 μm transmit 50%, foreign substances of 30 μm transmit 63%, foreign substances of 20 μm transmit 80%, and foreign substances of 10 μm transmit 96%. As described above, if a high-definition filter having a small mesh size is used, the efficiency of collecting foreign matters in the ink tank is increased, and the number of foreign matters in the ink supplied to the print head can be reduced. For this reason, it is possible to reduce an ink ejection failure due to foreign matter such as dust and obtain a stable high-quality image.
[0007]
However, in the configuration in which the foreign matter is captured by the filter as described above, the filter is clogged as the ink is consumed for a long time. In particular, when a filter having a small mesh size is installed on the print head side as described above, since fine foreign matter passes through the filter on the ink tank side and is captured by the filter on the print head side, the filter installed on the print head side Is easy to be clogged. When the filter is clogged, the fluid resistance of the filter increases, and when printing at a high printing density, the ink supply cannot catch up, and air is drawn in from the nozzles, causing image defects such as white spots and normal printing. There was a problem that it could not be done.
[0008]
FIG. 9 is a graph showing the transition of the fluid resistance value of the filter with respect to the used ink amount. The filter on the side of the print head used was a tatami twill filter having a mesh size of 12 μm, and the filter on the ink tank side was a tatami twill filter having a mesh size of 38 μm. The definition of the fluid resistance value here is P (Pa) = RQ (m ³ / Sec) and R (Pa · sec / m) ³ ). The viscosity of the ink used for the measurement was 2.0 × 10 ^-3 Pa · sec.
[0009]
As can be seen from FIG. 9, when the used ink amount is about 400 ml, the fluid resistance value of the filter exceeds the limit resistance value that allows normal printing. As described above, even if the print head has a long life, the filter may become unusable due to clogging of the filter.
[0010]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and has as its object to provide a recording apparatus that can withstand long-term use.
[0011]
[Means for Solving the Problems]
The invention according to claim 1 is a recording apparatus that supplies an ink contained in an ink tank to a print head, and forms an image by discharging the supplied ink from a nozzle, wherein the ink tank is the print head. In the recording apparatus configured to be detachable from the recording medium, the ink tank includes a first ink chamber capable of storing the ink therein in a negative pressure state, and an atmosphere communicating the first ink chamber with an outside atmosphere. A communication port, a communication hole for supplying ink from the first ink chamber, a first meniscus forming member having a mesh structure provided in the communication hole, and communicating with the communication hole and to the print head. A second ink chamber provided with a communicating joint portion, and a second meniscus forming member having a mesh structure provided in the joint portion; The filter is provided with a filter having a mesh structure for removing foreign matter, which is joined to the joint portion, wherein an average opening diameter of the second meniscus forming member and an average opening diameter of the filter are substantially the same. A flow path resistance to a nozzle is higher than a flow path resistance from the second meniscus forming member to the air communication port.
[0012]
According to a second aspect of the present invention, in the recording apparatus according to the first aspect, a flow path resistance from the filter to the nozzle is higher than a flow path resistance from the second meniscus forming member to the atmosphere communication port. It is characterized by the following.
[0013]
According to a third aspect of the present invention, in the recording apparatus according to the first or second aspect, the second ink chamber has an inclined surface on an upper side, and moves residual air above the second ink chamber. It is characterized by being made possible.
[0014]
According to a fourth aspect of the present invention, in the recording apparatus according to any one of the first to third aspects, an average opening diameter of the filter is equal to or smaller than a diameter of the nozzle.
[0015]
According to a fifth aspect of the present invention, in the recording apparatus according to any one of the first to fourth aspects, the mesh structure of the filter is a tatami-woven structure, and has an average opening diameter of about 12 μm. It is a feature.
[0016]
According to a sixth aspect of the present invention, in the recording apparatus according to any one of the first to fifth aspects, the mesh structure of the second meniscus forming member is a SUS tatami twill shape. Things.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a sectional view of a main part of an embodiment of the recording apparatus of the present invention, and FIG. 2 is a perspective view of the same main part. In the figure, 1 is an ink tank, 2 is a joint portion, 3 is a print head, 4 is an ink introduction portion, 11 is a main ink chamber, 12 is a capillary member, 13 is an air communication port, 14 is a first meniscus forming member, Reference numeral 15 denotes an ink guide member, 16 denotes an intermediate chamber, 17 denotes a second meniscus forming member, 18 denotes an outer peripheral portion of a joint, 19 denotes an ink guide member holder, 21 denotes a joining member, 22 denotes a filter, and 23 denotes an ink flow path. 1 and 2 show a state before the ink tank 1 is mounted. 1 and 2 show a configuration in which the print head 3 is mounted on the recording apparatus, and the ink tank 1 is mounted on the print head 3. Only the ink tank 1 and the portion of the ink flow path of the print head 3 are shown. Is illustrated. 2 shows one side wall of the ink tank 1 and the capillary member 12 removed. The ink tank 1 is connected to the print head 3 at the joint 2. When the joint portion 2 of the ink tank 1 comes into contact with the ink introduction portion 4 of the print head 3, the ink flow path is connected, and the ink is supplied from the ink tank 1.
[0019]
Inside the ink tank 1, a main ink chamber 11 and an intermediate chamber 16 below the main ink chamber 11 are provided. Inside the main ink chamber 11, a capillary member 12 is arranged. The capillary member 12 holds the ink by the capillary force and maintains a negative pressure. At an upper portion of the main ink chamber 11, an air communication port 13 that can communicate with the capillary member 12 by air is provided. A communication hole is provided below the main ink chamber 11 and communicates with the intermediate chamber 16. Since the capillary member 12 communicates with the atmosphere at the upper portion and is released from the atmospheric pressure, the ink in the capillary member 12 is pushed by the atmospheric pressure during ink supply, and the ink is supplied to the intermediate portion from below the capillary member 12 by a negative pressure. It is pulled out to the chamber 16 side. Further, the bottom surface of the main ink chamber 11 is formed as a slope having the communication hole as the lowest part.
[0020]
A first meniscus forming member 14 having a large number of fine holes is arranged in a communication hole provided on the bottom surface of the main ink chamber 11. The bottom of the capillary member 12 is placed in pressure contact with the first meniscus forming member 14. When the ink is impregnated in the capillary member 12, the ink passes through the first meniscus forming member 14 and moves to the intermediate chamber 16. When the ink is exhausted in the capillary member 12, the ink meniscus in the micropores of the first meniscus forming member 14 in contact with the capillary member 12 is pushed, and overcomes the surface tension to pass through it, forming bubbles. Move to the intermediate chamber 16. This keeps the ink supply pressure to the print head 3 constant.
[0021]
An ink guiding member 15 is provided below the first meniscus forming member 14. The ink guide member 15 is supported by an ink guide member retainer 19 that protrudes from a wall around the communication hole. Alternatively, a part of the first meniscus forming member 14 may be used as the ink guiding member 15. The ink guide member 15 extends to the bottom of the intermediate chamber 16. When bubbles accumulate on the lower surface of the first meniscus forming member 14 to form an air layer, or when the ink level in the intermediate chamber 16 decreases, the ink guide member 15 moves the ink in the intermediate chamber 16. To supply ink to the first meniscus forming member 14. Thereby, the first meniscus forming member 14 is always kept in a wet state, and a negative pressure is maintained. Further, the ink supply pressure can be maintained at the optimum state until the ink is used up.
[0022]
The intermediate chamber 16 has a portion extending above the communication hole. In FIG. 1, the upper wall of the intermediate chamber 16 is inclined so that the peripheral portion of the intermediate chamber 16 is higher than the communication hole. The intermediate chamber 16 accumulates air bubbles that have entered through the first meniscus forming member 14 and the second meniscus forming member 17 at a portion higher than the peripheral communication hole, and from the joint 2 to the print head 3. Air bubbles are prevented from entering, and air remaining in the joint is removed.
[0023]
A joint 2 for connecting to the print head 3 is provided at the bottom of the intermediate chamber 16. The joint portion 2 is provided with a second meniscus forming member 17 having a mesh structure and provided with a large number of fine holes serving as a filter on the ink tank 1 side. In a state where the ink tank 1 is removed and left as it is, the ink in the intermediate chamber 16 leaks from the joint portion 2 due to the surface tension of the ink formed in the fine holes provided in the second meniscus forming member 17. It does not come out and prevents air from entering the intermediate chamber from the joint. In addition, when the ink tank 1 is mounted, pressure fluctuation due to vibration, impact, and acceleration applied to the ink tank 1 is prevented. The second meniscus forming member 17 has an average opening diameter smaller than that of the first meniscus forming member 14 provided between the main ink chamber 11 and the intermediate chamber 16, and is provided on the print head 3 side described later. A filter having an average opening diameter substantially equal to that of the filter 22 is used.
[0024]
The joint outer peripheral portion 18 of the joint portion 2 is formed with a flat surface so that the joining member 21 provided on the print head 3 can easily abut.
[0025]
On the other hand, the print head 3 is connected to the joint 2 of the ink tank 1 at the ink introduction unit 4. A joining member 21 is arranged around the ink introduction unit 4. When the ink tank 1 is mounted, the joining member 21 abuts and deforms on the surface of the joint outer peripheral portion 18 of the ink tank 1 to seal the joint. Thus, it is possible to prevent the leakage of the ink from the joint. As a material of the joining member 21, for example, silicon rubber, butyl rubber, or the like can be used. It is also possible to configure without providing the joining member 21.
[0026]
Further, a filter 22 is arranged in the ink introduction unit 4. The filter 22 is provided in order to prevent dirt and the like adhering to the ink introduction unit 4 in a state where the ink tank 1 is removed, and foreign substances flowing with ink from the inside of the ink tank 1 from being mixed into the ink flow path 23. ing. In addition, the ink is held by the meniscus of the ink formed in the minute holes of the filter 22, and the outflow of the ink from the nozzles is prevented. The filter 22 has an average opening diameter substantially equal to that of the second meniscus forming member 17 provided on the ink tank 1 side.
[0027]
FIG. 3 is a graph showing the transition of the fluid resistance value of the filter with respect to the used ink amount in one embodiment of the printing apparatus of the present invention. Here, a tatami twill filter having a mesh size of 12 μm was used as the second meniscus forming member 17 and the filter 22. As can be seen from FIG. 3, in the case of this configuration, printing can be favorably performed up to an ink consumption of 800 ml. As compared with the conventional example shown in FIG. 9, the amount of ink used until reaching the printing limit resistance value can be approximately doubled.
[0028]
Conventionally, in order to prevent the filter 22 from being clogged, it is necessary to carefully clean a component that is a source of foreign matter in the ink tank 1 or to increase the diameter of the filter 22 on the print head 3 side. However, as in the present invention, by making the average opening diameter of the second meniscus forming member 17 equal to that of the filter 22 and improving the filter function, it is possible to realize a recording apparatus having a long life and high reliability without a large change. be able to.
[0029]
As the second meniscus forming member 17 and the filter 22, filters having various structures and materials such as a tatami twill filter made of stainless steel (SUS), a ceramic filter, an electroforming filter, and the like can be used. Of course, the material of the second meniscus forming member 17 and the material of the filter 22 may be different.
[0030]
FIG. 4 is an enlarged cross-sectional view of the vicinity of the joint when the ink tank is removed according to the embodiment of the recording apparatus of the present invention, and FIG. 5 is an enlarged cross-sectional view of the vicinity of the joint when the ink tank is mounted. Reference numerals in the figure are the same as those in FIG. When the ink tank 1 and the print head 3 are moved closer to each other from the state shown in FIG. 4, the joining member 21 disposed around the ink introduction unit 4 comes into contact with the plane of the joint outer peripheral portion 18 and is further pressed. , The tip portion is elastically deformed. This maintains the airtightness and shuts off the ink flow path from the outside air. The ink flows in the space between the closed joint portion 2 and the ink introduction portion 4, and the ink in the ink tank 1 is supplied to the print head 3.
[0031]
When the ink tank 1 is mounted, the joining member 21 is pressed and deformed, so that the joining portion is in a high pressure state higher than the atmospheric pressure. At that time, the excess air left at the joint pushes the second meniscus forming member 17 on the ink tank 1 side and the filter 22 on the print head 3 side. Normally, air escapes from the side having the larger average opening diameter, but in the present invention, the average opening diameter of the filter 22 on the print head 3 side and the average opening diameter of the second meniscus forming member 17 on the ink tank 1 side are substantially the same. Therefore, one of the factors causes a break from one of the two.
[0032]
First, when ink is not present on the print head 3 side, regardless of whether or not a meniscus of ink is formed on the filter 22 installed on the print head 3, the ink is stored in the high pressure state when the ink tank 1 is loaded. When the meniscus of the filter 22 is destroyed, it is released to the atmosphere. Therefore, most of the surplus air is released to the print head 3 side. Once the excess air is released to the atmosphere, it does not remain in the form of bubbles or the like, so that the problem of bubbles in the flow path of the print head 3 does not occur.
[0033]
Next, when ink is present on the print head 3 side, the bubble point pressure is exceeded in both the second meniscus forming member 17 on the ink tank 1 side and the filter 22 on the print head 3 side, so that bubbles Inflow begins. However, the speed of the bubble inflow is governed by the fluid resistance ratio ahead. The fluid resistance on the ink tank 1 side is the fluid resistance from the ink tank 1 to the second meniscus forming member 17, and the fluid resistance on the print head 3 side is the fluid resistance from the filter 22 to the nozzle.
[0034]
6A and 6B are configuration diagrams illustrating an example of a head chip unit, where FIG. 6A is a perspective view and FIG. 6B is a cross-sectional view. In the figure, 31 is a channel substrate, 32 is a heater substrate, 33 is a common liquid chamber, 34 is a nozzle, 35 is a dummy nozzle, and 36 is a heater. The print head 3 guides ink from the ink introduction unit 4 provided with the filter 22 to the head chip unit as shown in FIG. The head chip portion shown in FIG. 6 includes a channel substrate 31 in which a common liquid chamber 33, each nozzle 34, a dummy nozzle 35, and the like are formed, and a heater substrate 32 in which a heater 36 is formed corresponding to at least each nozzle 34. Are joined. The ink supplied from the ink flow path 23 is supplied from the common liquid chamber 33 to each nozzle 34 and the dummy nozzle 35. The dummy nozzle 35 is not used at the time of actual printing, but is used, for example, at the time of maintenance or the like to remove bubbles at the time of idle discharge or suction operation.
[0035]
In a specific head chip, the configuration may be such that the nozzle 34 has 160 nozzles and the dummy nozzle 35 has 34 nozzles. The nozzle 34 is an isosceles triangle having a height of about 29 μm and a base angle of about 55 °. The dummy nozzle 35 is larger than the nozzle 34 and reduces the flow path resistance to promote the discharge of bubbles and dust.
[0036]
In the head chip having the structure shown in FIG. 6, the ink flow path to the nozzles 34 and the dummy nozzles 35 has a bent structure in order to effectively use the pressure generated by the heater 36. Due to such a flow path structure and the cross-sectional area of the nozzle, the flow path resistance of the head chip portion is extremely large.
[0037]
In an actual printing apparatus, when the fluid resistance on the ink tank 1 side and the fluid resistance on the print head 3 side are compared,
R (ink tank) = 1.6 × 10 ⁹ (Pa · sec / m ^Three )
R (print head) = 3.0 × 10 ¹¹ (Pa · sec / m ^Three )
It was. As described above, the flow path resistance is very large on the print head 3 side. At this time, considering the behavior of the excess air remaining at the joint between the ink tank 1 and the print head 3, the air bubble mixing speed on the ink tank 1 side and the print head 3 side is faster than the ink tank 1 side by 100 times or more. I understand. That is, 99% of the surplus air is released into the intermediate chamber 16 on the ink tank 1 side. Therefore, the excess air at the connection portion hardly enters the ink flow path 23 of the print head 3 as air bubbles.
[0038]
Actually, it is thought that the fluid capacitance and the fluid inductance component act in addition to the flow path resistance component. However, the fluid capacitance is overwhelmingly large on the ink tank 1 side, and the fluid inductance is overwhelmingly large on the print head 3 side. Therefore, the air bubble mixing speed ratio should be further increased.
[0039]
As described above, by making the average opening diameter of the filter 22 on the print head 3 side and the average opening diameter of the second meniscus forming member 17 on the ink tank 1 side of the present invention substantially the same, An increase in pressure loss due to clogging can be suppressed, and a highly reliable and long-life recording apparatus can be realized. Further, according to the present invention, air bubbles when the ink tank 1 is mounted can be released into the intermediate chamber 16 of the ink tank 1.
[0040]
The air bubbles that have entered the intermediate chamber 16 move to the upper part of the intermediate chamber 16 and are accumulated in a portion above the communication hole along the slope on the upper part of the intermediate chamber 16. Therefore, the flow of the ink in the ink tank 1 is not hindered by the bubbles that have entered the intermediate chamber 16, and a good ink supply is performed.
[0041]
The smaller the average opening diameter of the filter 22 and the second meniscus forming member 17 is, the more the foreign matter can be prevented from entering the print head 3. However, when the average opening diameter is small, the flow path resistance increases and approaches the printing limit resistance even in the initial state. Air bubbles and foreign matter that have passed through the filter 22 reach the head chip as shown in FIG. 6 via the ink 23. However, if the foreign matter is sufficiently smaller than the diameter of the nozzle 34, the ink flow may be greatly impeded. In addition, since the ink is discharged to the outside from the nozzles 34 and the dummy nozzles 35 during, for example, normal printing or maintenance, it hardly affects the recorded image. For this reason, the average opening diameter of the filter 22 and the second meniscus forming member 17 may be set to an optimal size in consideration of the overall flow resistance, the nozzle diameter, and the like.
[0042]
Further, the average opening diameter of the filter 22 and the second meniscus forming member 17 may not be completely the same, and a certain difference is allowed. FIG. 8 shows the transmittance for each size (10 to 40 μm) of the foreign matter according to the mesh size (12 to 38 μm) of the tatami twill as described above, for example, 10 μm for a tatami twill filter having a mesh size of 12 μm. 55% of the foreign matter is transmitted. For example, even if a tatami twill filter having a mesh size of 12 μm for the filter 22 and a mesh size of 13 μm for the second meniscus forming member 17 is used, the amount of foreign matter reaching the filter 22 as compared with the conventional case where the mesh size is 38 μm. Can be reduced to about 4% for a foreign substance of 40 μm and about 24% for a foreign substance of 30 μm, so that clogging of the filter 22 can be reduced. In this case, too, the excess air in the connecting portion is released to the ink tank 1 side, and the incorporation of bubbles into the print head 3 can be reduced, so that image defects due to bubbles hardly occur.
[0043]
FIG. 7 is an explanatory diagram of an example of the determination result of the used ink amount and the life based on the combination of the average opening diameters of the filter 22 and the second meniscus forming member 17. As shown in FIG. 7, a recording experiment was performed using various average opening diameters as the filter 22 and the second meniscus forming member 17. Here, the diameter of the second meniscus forming member 17 on the ink tank 1 side is 5 mm, and the diameter of the filter 22 on the print head 3 side is 4 mm. A sheet of A4 size was used as the recording sheet, and recording corresponding to about 2.0% of coverage was performed. The used ink amount at this time is 0.029 ml / sheet when the resolution is 400 × 400 dpi, and 0.033 ml / sheet when the resolution is 400 × 800 dpi.
[0044]
Printing limit resistance value is 1 × 10 ¹⁰ Pa / sec · m ³ Recording was performed until the fluid resistance reached the printing limit resistance for each combination of mesh sizes. As the evaluation result at this time, the used ink amount until the fluid resistance value reaches the printing limit resistance value, the number of printed sheets at a resolution of 400 × 400 dpi, the number of printed sheets at a resolution of 400 × 800 dpi, and the determination result are shown. . Judgment results are as follows. The life target is set to 20,000 sheets in A4 size, and the resolution 400 × 400 dpi and 400 × 800 dpi are marked with a circle for the combination that has achieved this life target, and the combination that shows a result that far exceeds the life target is shown. ◎ is marked. In addition, combinations that have achieved the life target only in the case of the resolution of 400 × 400 dpi are indicated by Δ, and combinations that have not reached the life target are indicated by X.
[0045]
As can be seen from FIG. 7, when the average opening diameter of the second meniscus forming member 17 and the filter 22 is largely different, the life target cannot be achieved (×), and the life target is achieved at almost the same average opening diameter (○ or ◎). is made of. At this time, even if the average opening diameter is slightly different, the life target can be almost achieved. For example, when the average opening diameter of the filter 22 is 12 μm, in a recording apparatus having a resolution of 400 × 400 dpi, the life target can be achieved when the average opening diameter of the second meniscus forming member 17 is 16 to 12 μm. When the average opening diameter of the second meniscus forming member 17 is 12 μm, the life target can be achieved when the average opening diameter of the filter 22 is about 12 to 5 μm in a recording apparatus having a resolution of 400 × 400 dpi.
[0046]
Although not shown in FIG. 7, if the average opening diameter of the second meniscus forming member 17 is too small than the average opening diameter of the filter 22, air bubbles may enter the print head 3 as described above. Increases, and as it is, image quality defects due to bubbles increase. In order to avoid this, there is a problem that it is necessary to frequently perform ink suction for maintenance and to remove bubbles. Therefore, even when the average opening diameter of the second meniscus forming member 17 is smaller than the average opening diameter of the filter 22, there is an allowable range of the difference in the average opening diameter, and it is preferable that the difference be within that range. .
[0047]
As described above, the difference between the average opening diameter of the second meniscus forming member 17 on the ink tank 1 side and the average opening diameter of the filter 22 on the print head 3 side is allowed within a certain range, and the average opening diameter of both is within the same range. The caliber may be set.
[0048]
【The invention's effect】
As is apparent from the above description, according to the present invention, the average opening diameter of the meniscus of the second meniscus forming member provided at the connection portion on the ink tank side and the filter provided at the connection portion on the print head side are provided. By making the average opening diameters substantially the same, it is possible to provide a recording apparatus capable of reducing clogging of the filter and enduring long-term use. By setting the opening diameter of the filter to be equal to or smaller than the diameter of the nozzle as in the invention described in claim 4, foreign matter that has passed through the filter does not block the nozzle. The filter may be, for example, a tatami-woven structure having an average opening diameter of about 12 μm. Further, the second meniscus forming member can be a SUS tatami twill filter, for example, as in the invention described in claim 6.
[0049]
Further, as in the second aspect of the invention, the flow path resistance from the filter on the print head side to the nozzle is higher than the flow path resistance from the ink tank side to the second meniscus forming member. When the ink tank is joined, the compressed air remaining between the second meniscus forming member and the filter can be guided to the second ink chamber in the ink tank via the second meniscus forming member. Therefore, it is possible to reduce image quality defects due to bubbles entering the print head. Since the air bubbles guided to the second ink chamber move upward in accordance with the upper inclined surface in the second ink chamber as in the third aspect of the invention, the air bubbles in the ink tank are moved by the air bubbles. Flow is not impeded. As described above, the present invention has various effects.
[Brief description of the drawings]
FIG. 1 is a sectional view of a main part of an embodiment of a recording apparatus of the present invention.
FIG. 2 is a perspective view of a main part of an embodiment of the recording apparatus of the present invention.
FIG. 3 is a graph showing a transition of a fluid resistance value of a filter with respect to a used ink amount in an embodiment of the recording apparatus of the present invention.
FIG. 4 is an enlarged cross-sectional view of the vicinity of a joint when an ink tank is removed in an embodiment of the recording apparatus of the present invention.
FIG. 5 is an enlarged cross-sectional view of the vicinity of a joint when an ink tank is mounted in an embodiment of the recording apparatus of the present invention.
FIG. 6 is a configuration diagram illustrating an example of a head chip unit.
FIG. 7 is a diagram illustrating an example of a determination result of a used ink amount and a life based on a combination of mesh sizes of a filter 22 and a second meniscus forming member 17;
FIG. 8 is an explanatory diagram of an example of a relationship between a filter particle size and a transmission efficiency of a filter.
FIG. 9 is a graph showing a transition of a fluid resistance value of a filter with respect to a used ink amount.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Ink tank, 2 ... Joint part, 3 ... Print head, 4 ... Ink introduction part, 11 ... Main ink chamber, 12 ... Capillary member, 13 ... Atmospheric communication port, 14 ... First meniscus forming member, 15 ... Ink Guide member, 16: Intermediate chamber, 17: Second meniscus forming member, 18: Joint outer peripheral portion, 19: Ink guide member holder, 21: Joining member, 22: Filter, 23: Ink flow path, 31: Channel substrate, 32: heater substrate, 33: common liquid chamber, 34: nozzle, 35: dummy nozzle, 36: heater.

Claims (6)

A recording apparatus that supplies ink contained in an ink tank to a print head and discharges the supplied ink from nozzles to form an image, wherein the ink tank is configured to be detachable from the print head. In the recording apparatus, the ink tank includes a first ink chamber capable of storing the ink therein in a negative pressure state, an air communication port that communicates the first ink chamber with an external atmosphere, and the first ink chamber. A communication hole for supplying ink from the chamber, a first meniscus forming member having a mesh structure provided in the communication hole, and a joint portion communicating with the communication hole and communicating with the print head. And a second meniscus forming member provided in the joint portion and having a mesh structure, wherein the print head is joined to the joint portion. Is provided with a filter mesh structures for removing foreign matters, the recording apparatus, wherein the average opening diameter of the the average opening diameter of the second meniscus forming member filter are substantially identical. The recording apparatus according to claim 1, wherein a flow path resistance from the filter to the nozzle is higher than a flow path resistance from the second meniscus forming member to the air communication port. 3. The recording apparatus according to claim 1, wherein the second ink chamber has an inclined surface at an upper side, and the residual air is movable above the second ink chamber. 4. 4. The recording apparatus according to claim 1, wherein an average opening diameter of the filter is equal to or smaller than a diameter of the nozzle. 5. The recording apparatus according to any one of claims 1 to 4, wherein the mesh structure of the filter has a twill weave shape, and has an average opening diameter of about 12 m. The recording apparatus according to any one of claims 1 to 5, wherein the mesh structure of the second meniscus forming member has a SUS tatami twill shape.

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