JP3267457B2 - Ink jet device and ink supply device used for the device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet apparatus for performing recording by discharging ink and an ink supply apparatus through which the ink flows.

[0002]

2. Description of the Related Art An ink jet recording system for performing recording by discharging ink from a recording means to a recording medium is widely used for reasons such as quietness and low cost. Above all,
A configuration in which an ink container is also provided on a carriage on which a recording unit is mounted in order to perform a recording scan on a recording medium,
In addition to the above-mentioned advantages, it has become mainstream because the size of the device can be further reduced.

One of the reasons for the miniaturization is that there is no need to provide a long liquid supply path such as an ink tube for supplying ink from the ink storage section to the recording means, so that the configuration of the apparatus is simplified. What you can do.
Accordingly, since there is no invasion of gas from the ink tube or the like, the reliability of the apparatus itself is guaranteed for a long time.

[0004] At present, the above-mentioned recording means and the ink storage section are integrated into a single unit when mounted on the apparatus, but have a cartridge form such as a recording head cartridge or an ink cartridge which can be individually removed.

[0005] This is advantageous in that when ink can no longer be ejected from the recording means, it is possible to perform recording again by replacing only the ink containing section, thereby reducing running costs. is there.

Also, since the number of parts is smaller than in the case where the recording means and the ink container are integrated, the processing of the used ink container and other replacement units is easy, and the environment is reduced. There are advantages that the influence can be reduced.

[0007] In addition to the miniaturization of the above-described apparatus, high image quality and high speed due to high definition of the image are required at present. In order to achieve this high definition, a method of making the ink discharge nozzles usually provided in the recording means finer is often used.

[0008]

In the case where the nozzles are made fine for high definition, the mesh size of the filter for dust removal provided in the ink supply path from the ink storage section to the recording means is increased. Needs to be made finer. On the other hand, in order to increase the speed, it is necessary to increase the ink supply amount per unit time from the ink storage unit to the recording unit. As a result, in order to achieve both high definition and high speed, the pressure difference before and after the filter tends to increase. Therefore, there is a possibility that the pressure loss increases and the response frequency decreases.

An effective means for suppressing this is to increase the filter area in the filter section to increase the effective area when ink passes. The filter section is generally provided with a filter chamber between the ink supply path connecting the ink discharge section and the ink storage section of the recording means. However, the recording section and the ink storage section are required to reduce the size of the apparatus itself. When the cartridge type is used, there is a limit in increasing the filter area.

When the total area of the walls constituting the flow path is increased by enlarging the filter chamber, recording means (hereinafter referred to as recording) such as a cartridge type ink container (hereinafter also referred to as an ink cartridge) and a recording head. Even if a head cartridge is used, a phenomenon similar to the intrusion of gas into the ink supply path often observed when the recording means and the ink storage section are connected by a tube or the like during long-term use. Is generated, and gas is likely to enter the inside through members constituting the respective outer walls, thereby increasing the possibility of forming bubbles in the ink flow path.

When the state in which the air bubbles adhere to the above-described filter is maintained and the effective area of the filter is reduced, the response frequency is lowered and the ejection becomes unstable. Therefore, it can be said that it is difficult to maintain stable ejection simply by increasing the filter area of the filter section.

Usually, the removal of bubbles adhering to the filter is performed by a suction recovery process from the discharge port of the recording means. However, a large-capacity suction device is required to completely remove the bubbles. Would go against the trend of miniaturization.

In particular, this phenomenon is shown in FIG. 9 in which the filter unit is configured such that the ink storage unit is arranged above the direction of gravity and the ink discharge means is arranged below the unit in order to reduce the size of the apparatus in the width direction. As described above, when the ink flow path 4 is provided along the direction of gravity, the above-described problem becomes significant. This is because bubbles in the ink flow path below the filter are more likely to adhere to the filter due to buoyancy, and the bubbles in the filter section are more likely to grow to reduce the effective area.

On the other hand, the air bubbles 30 located on the ink container side of the filter have their buoyancy (arrow C in the figure) resisting the force (arrow D in the figure) acting to pass through the filter by the suction recovery process. Therefore, the possibility of remaining is increased.

In view of the above, an object of the present invention is to provide an ink jet apparatus and an ink supply apparatus which do not cause an increase in the size and complexity of an ink jet apparatus due to an increase in the size of a recording head cartridge having an ink flow path. The purpose is.

It is another object of the present invention to prevent deterioration of the quality of a recorded image due to instability of ejection due to attachment of bubbles to the filter portion.

Further, even when the size of the apparatus is reduced in the width direction by providing the filter with an ink storage section above the gravitational direction and an ink discharge means below the filter,
It is an object of the present invention to provide an ink jet device and an ink supply device that can more reliably remove bubbles.

[0018]

According to the present invention, there is provided an ink jet apparatus having an ink flow path for communicating an ink storage section for storing ink with a discharge section for discharging ink. In the apparatus, the ink storage unit is located above the ejection unit, and the ink flow path is a filter chamber having a filter.
A communication between the filter chamber and the ink storage unit.
The first ink passage communicates with the filter chamber and the discharge section.
A second ink flow path,
The filter chamber extends in a direction crossing the horizontal direction
Wherein the first ink flow path is open below the chamber.
The second ink flow path is opened above the chamber.
Form at least two curved portions with
The filter chamber is cut near the curved portion above the gravity direction.
This provides a configuration in which the cross-sectional area near the lower curved portion is larger than the area .

Further, in addition to the above configuration, a configuration in which the ink flow path between the curved portions intersects with the direction of gravity is also proposed.

The present invention also relates to an ink containing ink.
The storage section is communicated with a discharge section for discharging the ink.
Ink supply device having an ink flow path
Each has two curved portions, and the ink flow path between the curved portions is a gravity direction.
Extending in a direction crossing a direction orthogonal to the
In the ink flow path between the curved portions along the extending direction.
Filter is provided between the music section
The cross section of the ink flow path near the curved portion above the gravity direction
Provides a configuration with a larger cross-sectional area near the lower bend than the product
Things.

[0021]

In addition, the present invention also provides a configuration in which a valve having a total area smaller than the total area of the filter is provided between the filter in the chamber and the opening of the first flow path. Here, a configuration may be adopted in which a groove is provided on the filter side of the valve.

[0023]

By adopting the above structure, when a pressure difference is generated between the front and rear of the filter by a recovery process or the like in order to remove the air bubbles attached to the filter, the force is efficiently applied to the air bubbles. In addition, the air bubbles can easily pass through the filter section.

Further, it is possible to suppress a decrease in the effective area of the filter portion caused by the bubbles, and to maintain a stable recording quality.

[0025]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In addition,
In the drawings, the same reference numerals denote the same functions.

First, FIG. 1 shows a schematic perspective view of an ink-jet apparatus IJRA according to the present invention as an example of the apparatus. In FIG. 1, reference numeral 1 denotes an ink cartridge serving as an ink storage unit, and reference numeral 8 denotes a carriage on which the ink cartridge 1 and a recording head cartridge 2 serving as recording means to be described later are detachably mounted.

Reference numeral 9 denotes a lead screw for causing the carriage 8 to scan the recording medium 11 such as recording paper or a thin plastic plate, and 10 denotes a guide rail for guiding the carriage 8 to scan. Here, the lead screw 9 is interlocked with the forward and reverse rotation of the drive motor 15 via the gears 13 and 14, and further, a spiral groove 12 engraved on the lead screw 9 is provided on the carriage 8 with an engaging portion (not shown). The scanning of the carriage 8 is performed in the longitudinal direction of the apparatus by driving the drive motor 15. Then, the recording material 11 is transported by the platen roller 16.

In addition, a recovery unit for a discharge unit provided in a recording unit, which will be described later, is provided adjacent to the conveyance area of the recording material 11. The recovery means sucks and recovers the discharge portion through a cap member 20 for capping a discharge port portion (not shown) of the recording head cartridge and an internal opening (not shown) provided in the cap member 20. It comprises a suction means 21. The driving force is transmitted from the drive motor 15 to the suction unit by a known transmission unit such as a gear 22 and a switching clutch.

The upward and downward movement of the cap member 20 is performed by a driving force transmitted through the gear 23 and the like. Can be reduced.

Further, the above-described suction recovery processing not only recovers clogging of the discharge port or the like, but also discharges ink from the ink cartridge to the discharge portion by changing the suction amount to remove fine dust and air bubbles. It is possible to remove not only from the filter section but also from the inside of the ink flow path. The ink flow path recovery processing is periodically or forcibly performed when the user determines that it is necessary, so that good print quality can be maintained.

The above-described capping and suction recovery processes are performed at the corresponding positions when the carriage 8 comes to the area on the home position side. Each of these processes is performed singly or in combination in an arbitrary manner using a known timing and sequence.

As a first reference example according to the present invention, FIG. 2 is a schematic sectional view showing an example of a carriage section of an ink jet apparatus. FIG. 3 is an enlarged sectional view of the ink flow path 4 as the ink supply system (ink supply device) in FIG. Here, the arrow A in the figure indicates the direction of gravity.

In FIG. 2, reference numeral 1 denotes an ink cartridge which is an ink container for storing ink, and reference numeral 2 denotes a recording head cartridge as recording means for performing recording using the ink supplied from the ink cartridge 1.

Reference numeral 3 denotes a discharge unit having a nozzle (discharge port) for discharging ink, and 4 denotes an ink cartridge.
And an ink flow path that communicates with the discharge unit 3. And 5
Is a joint for connecting the inside of the ink cartridge and the ink flow path 4 in a watertight manner when the ink cartridge is mounted, and for closing the ink cartridge when the ink cartridge is removed, and is made of an elastic member such as rubber in this embodiment. Here, an end of the ink flow path 4 is connected to the joint 5 made of the elastic member by a conventionally known method.

The ink flow path 4 includes a return flow path section 7 having a filter 6, and an ink flow path for communicating the return flow path section 7, the ink storage section, and the discharge section. In this embodiment, the return channel is constituted by a filter chamber.

[0036] Although not described in detail in the present embodiment,
The ink cartridge 1 is provided with a well-known pressure adjusting mechanism such as a multi-chamber structure having a communication portion forming a meniscus, so that the pressure of the nozzle portion is reduced to the atmospheric pressure or less so that ink does not leak from the nozzle.

The above-described ink cartridge 1 and recording head cartridge 2 are configured to be detachably mounted on the carriage 8. The carriage 8 is supported by a guide shaft 9 which is a rail provided in the ink jet device, and scans on the guide shaft during recording. In this embodiment, the recording medium 10 is arranged in a direction intersecting with the direction of gravity, and the ink ejected from the nozzle 3 flies along the direction of gravity.

[0038] Next, the flow of ink and bubbles in the present embodiment. When the ink is ejected through the ejection port by the above-described recovery processing device or the like, the ink in the ejection unit 3 is sucked out from the nozzle, and new ink is supplied from the ink cartridge 1 to the ejection unit 3.

The flow of ink at this time will be described below with reference to FIG. In FIG. 3, the ink flow path 4a is a communication path with the ink cartridge 1 containing ink, and the lower part of the ink flow path 4b is a communication path with the recording head cartridge 2 having an ejection section. Then, the cross-sectional shape of the ink flow path is bent at the upper and lower portions of the filter chamber 7 and has a bent shape. Therefore, the ink flow path 4
Has a curved portion at each of the location where the ink flow path 4a and the return flow path 7 communicate and the location where the return flow path 7 communicates with the ink flow path 4b. In other words, the return flow path has a curved portion. It will be located between the curved parts.

The ink flows downward in the direction of gravity from the ink cartridge 1 side in the ink flow path 4a, flows into the vicinity of the lowermost part of the return flow path 7 in which the filter 6 is arranged, and thereafter, returns to the return flow path 7 Inside, the ink flows in the direction opposite to the direction of gravity, that is, in the direction in which buoyancy acts as indicated by B in the figure. Then, the ink flows into the ink flow path 4b from the vicinity of the uppermost part of the return flow path, flows downward again in the direction of gravity, and reaches the discharge section 3 side having the nozzle. Here, the acting force on the ink flow is caused by the difference in pressure acting on the ink cartridge and the ejection section formed by the close contact between the suction means 21 and the cap 20.

On the other hand, the bubbles having a certain size move along with the flow of the above-mentioned ink. In order to promote this, in this embodiment, the ink flow paths 4a and 4b are used.
b is relatively thin and has a uniform cross section. For this reason, the flow velocity becomes high in the ink flow paths 4a and 4b, and the air bubbles adhering to the flow path walls are easily peeled off, and are easily discharged from the discharge section during the recovery processing.

The filter chamber 7 provided as a return channel extends in the direction of gravity.
The lower part and the upper part communicate with the ink flow paths 4a and 4b, respectively. In this modification , openings are provided at the lowermost part and the uppermost part, respectively. This is the ink flow path 4
This is because the ink itself has a continuous flow path configuration in which the ink stagnation portion is unlikely to occur, and the loss when the suction force from the recovery system acts on the ink is reduced, and the force acting on the bubbles can be increased. .

Since the ink flows in the filter chamber along the direction of the buoyancy acting on the air bubbles, the air bubbles adhering to the filter 6 during the recovery process can be easily separated. Air bubbles in the ink flow path 4a also easily pass through the filter 6. Therefore, the removal of air bubbles from the filter portion by the suction recovery process can be made more reliable.

Further, in the present application, since the filter is provided along the direction of ink flow in the filter chamber 7 serving as the return flow path, the cross-sectional area of the return flow path in the ink flow direction is increased. Without
The effective area of the filter can be increased. Thereby, it is possible to reduce the pressure loss generated when the ink passes through the filter 6 at the time of recording or the like without increasing the size of the apparatus, and to increase the ink supply amount per unit time for speeding up, Even if the mesh size of the filter is reduced for higher definition, the supply capacity does not decrease.

FIG. 4 shows an example of the second reference example according to the present invention.
And FIG. FIG. 4 is a schematic cross-sectional view of a carriage section of the inkjet apparatus. FIG. 5 is an enlarged sectional view of the ink flow path 4 in FIG.

[0046] In this reference example, as compared with the above-described embodiment as shown in FIG. 4, the configuration is inclined with respect to the filter chamber 7b is (horizontal direction perpendicular to or gravity direction) direction of gravity different ing.

[0047] Other configurations are the same as in the first reference example, the ink flow path 4ky beauty 4b as shown in FIG. 5 is relatively thin, a cross-section uniform shape, the ink flow path 4a and 4b Inside, the flow velocity increases, and ink flow paths 4a and 4b are respectively opened at the lowermost and uppermost parts of the filter chamber 7b provided as a return flow path.

As described above, since the filter chamber 7b is provided so as to be inclined with respect to the direction of gravity and the horizontal direction perpendicular to the direction of gravity, the total number of bent portions in the cross-sectional shape is reduced, and the length of the ink flow path is reduced. Can be shortened. As is clear from FIGS. 3 and 5, when the ink flow paths 4 of the respective forms are provided in the same sectional area, L2
Since a + L3 + L4> L2 '+ L3' + L4 ', than the total flow path length better total flow path length of the reference example is shorter in the first reference example. Therefore, by using the configuration of the present reference example, the total flow path resistance is further reduced, and it becomes easier to realize high-speed recording and high-definition, and the loss of the force acting on the bubbles in the filter portion at the time of recovery. Can be reduced. Therefore, air bubbles can be more reliably removed by the suction recovery process.

Further, the probability of gas infiltration into the ink flow path due to gas permeation and the like often seen during long-term use can be further reduced by reducing the total flow path wall area.

[0050] Further, with the configuration in which the filter 6 along the inclined channel 7b as in this reference example, fine bubbles can not easily attached to the filter 6 becomes easy to carry out even removed from the ink flow path Was found. The fine bubbles described above are likely to be generated when a surfactant is contained in the ink as a technique for obtaining high image quality. Since such a bubble has a small cross-sectional area, the ink pressure does not sufficiently act, and it is difficult to pass through the filter. In particular, when the bubbles having the same size as the mesh size of the filter adhere to the filter, they tend to be present in a stable state due to surface tension or the like, so that it is difficult to remove the bubbles and the effective area of the filter is reduced.

However, by adopting the configuration of the present invention, the buoyancy of the bubbles is reduced because the folded ink flow path 7b and the filter 6 are arranged so as to have an angle with respect to the direction of gravity and the horizontal direction perpendicular to the gravity. Acts in the direction away from the filter.

Therefore, even when the ink is flowing, the bubbles are not easily attached to the filter and are easily peeled off, and at the same time, the bubbles move along the flow path wall into the upper space of the filter chamber which is the folded ink flow path. The fine bubbles are connected to each other and grow to form large bubbles 30. As a result,
Fine bubbles can also be removed in the same way as ordinary bubbles, and it can be suppressed that the effective area of the filter is reduced by the bubbles,
High quality images can be provided.

(Embodiment) An embodiment of the present invention is shown in FIG. FIG. 6A is a schematic sectional view of the ink flow path 4, and FIG. 6B is a schematic sectional view showing a PP section in FIG. 6A. In the present embodiment, the trapezoidal shape shown in FIG. 6B is different from that of the above-mentioned second reference example in that the cross-sectional area of the flow path decreases as the shape of the filter chamber of the ink flow path 4 goes upward. A folded channel is adopted.

By employing this configuration, the flow velocity of the ink that has flowed into the filter chamber from the ink flow path 4a once decreases and then rises above the filter chamber 7b, and the filter chamber where the bubbles 30 are most likely to be located. The flow velocity is highest at the top of 7b.

Thus, in addition to the effects of the above-described reference example, the force required for the bubbles 30 to pass through the filter 6 can be reduced, so that the filter portion required for the suction means can be reduced. Acting force is reduced. Therefore, it is possible to cope with higher definition of an image by further miniaturization of the apparatus or finer nozzles, that is, finer mesh size. Although the trapezoidal shape is used in the present configuration, the shape for decreasing the cross-sectional area upward is arbitrary, and is not limited to this.

As another modified example for increasing the ink flow velocity near the opening communicating with the ink flow path 4b above the folded ink flow path 7b, a valve mechanism is provided in the above-described configuration, and a valve mechanism is provided during recovery processing. FIG. 7 shows a configuration for increasing the flow rate. FIG. 7A is a schematic sectional view of the ink flow path 4 and FIG.
(B) is a schematic sectional view showing a QQ section in FIG. 7 (a).

As shown in FIG. 7A, in this configuration, the valve 17 is provided at a position separated from the filter 6 when recording is stopped and when recording is performed. The valve 17 is provided closer to the ink flow path 4a than the filter 6 in the filter chamber, that is, closer to the ink storage unit. Here, valve 1
Reference numeral 7 denotes a sheet having a thickness of 10 to 100 μm.
It is formed of a resin such as S.

The valve 17 does not come into contact with the filter portion in the case of a gentle ink flow at the time of recording or the like. The shape and the material are not limited to those having the elasticity to decrease.

By employing this configuration, it is possible to reliably generate a pressure difference and a pressure at which air bubbles can pass through the filter 6 at the time of recovery, but do not lower the print quality at the time of recording.

In the case of the configuration shown in FIG. 7, bubbles that enter between the filter 6 and the valve 17 and adhere to the filter 6 are likely to be difficult to remove during normal suction recovery. Since the effective area of the filter may be reduced or the valve may not function effectively at the time of recovery, it is desirable to adopt the following valve configuration.

FIG. 8 shows the configuration. FIG. 8A shows FIG.
FIG. 3 is a schematic view showing the shape of the valve as viewed from the Q direction in FIG.
FIG. 8B is a schematic sectional view showing an RR section in FIG. 8A. In this configuration, the groove 18 is provided in the valve 18. In particular, this configuration is effective when air bubbles are attached and stay between the filter and the valve due to surface tension or the like. Due to the action of the groove 19 to return to a spherical shape due to the buoyancy and surface tension of the bubble itself, the upward movement of the filter chamber can be promoted, and the bubble can be discharged from between the filter and the valve.

[0062]

As described above, by using the structure of the present invention, the structure in which the ink flows in the direction of the buoyancy acting on the air bubbles in the filter portion is adopted, so that the ink adheres to the filter. In addition to facilitating the removal of bubbles, bubbles in the ink flow path also easily pass through the filter. Therefore, air bubbles can be more reliably removed by the suction recovery process.

Further, an ink flow path section which is a folded flow path section located between the curved sections provided in the ink flow path and intersects with a direction orthogonal to the direction of gravity is provided. Since the filter is provided in the direction in which the ink flow path between the portions extends, that is, in the direction of the ink flow, the filter is provided in the ink flow direction of the return flow path as in the case where the conventional filter portion is provided. It is possible to increase the effective area of the filter without increasing the cross-sectional area, thereby reducing the pressure loss that occurs when ink passes through the filter during printing, and increasing the speed per unit time for speeding up. Even if the ink supply amount is increased or the mesh size of the filter is reduced for higher definition, the supply capacity does not decrease. Further, the loss of the acting force acting on the bubbles during the recovery process can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an example of an inkjet apparatus according to the present invention.

Schematic cross-sectional view showing an example of a carriage portion of the ink jet apparatus which is a first reference example of the present invention; FIG.

FIG. 3 is an enlarged sectional view of an ink flow path in FIG. 2;

FIG. 4 is a schematic cross-sectional view illustrating an example of a carriage unit of an inkjet apparatus according to a second reference example of the invention.

FIG. 5 is an enlarged sectional view of an ink flow path in FIG.

FIGS. 6A and 6B are schematic sectional views showing an embodiment of the present invention .

FIGS. 7A and 7B are schematic sectional views showing a modification of the present invention .

8A and 8B are schematic cross-sectional views showing a modification of the embodiment of FIG.

FIG. 9 is a schematic sectional view showing a conventional ink flow path.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink cartridge 2 Recording head cartridge 3 Discharge part 4 Ink flow path 5 Joint part 6 Filter 7 Return flow path (filter chamber) 8 Carriage 9 Lead screw 10 Guide rail 11 Recording member 12 Spiral groove 13 Gear 14 Gear 15 Drive motor 16 Platen roller 17 Valve 18 Grooved valve 19 Groove 20 Cap member 21 Suction device 22 Gear 23 Gear

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-257857 (JP, A) JP-A-6-64183 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/175

Claims (6)

(57) [Claims] 1. An ink jet apparatus having an ink flow path for communicating an ink containing section for containing ink with a discharge section for discharging ink, wherein the ink containing section is located above the discharge section. Wherein the ink flow path includes a filter chamber provided with a filter;
A first inlet for communicating the filter chamber with the ink storage unit.
Ink passage, the filter chamber, and the discharge section.
A second ink flow path, wherein the filter and the filter chamber intersect in a horizontal direction.
Extends in the direction of the difference, the first ink flow path is opened downward of the chamber, the first
The second ink flow path is opened above the chamber to reduce
At least two curved portions are formed, and the filter chamber is located near a curved portion above the direction of gravity.
An ink jet apparatus, wherein a cross-sectional area near a lower curved portion is larger than a cross-sectional area . 2. The ink jet apparatus according to claim 1, wherein the ink flow path between the curved portions also intersects with the direction of gravity. 3. A valve having a total area smaller than the total area of the filter is provided between the filter in the chamber and the opening of the first flow path.
An inkjet device according to item 1. 4. The ink jet apparatus according to claim 3, wherein a groove is provided on the filter side of the valve. 5. An ink supply device having an ink flow path for communicating an ink containing portion for containing ink with a discharge portion for discharging the ink, the ink supply device having at least two curved portions, and between the curved portions. ink flow path extends in a direction intersecting the direction perpendicular to the direction of gravity, with the ink flow path between the curved portion and the filter is provided along the the extending direction an ink flow path between the bent portion is provided above the tracks with respect to the direction of gravity
An ink supply device characterized in that a cross-sectional area near a lower curved portion is larger than a cross-sectional area near a portion . 6. The ink supply device according to claim 5, wherein the ink flow path between the curved portions also intersects with the direction of gravity.