JPH09109409A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the mixing of air bubbles with ink by providing a spiral groove or projection to the surface opposed to the filter on the side of the outlet hole of the filter chamber in an ink supply passage. SOLUTION: Spiral grooves 6, 6 are provided to the surface 2a opposed to the filter 3 on the side of the outlet hole 5 of a filter chamber 2 and, when the ink in the filter chamber 2 flows out of the outlet hole 5, counterclockwise spiral flow is generated to the ink from the outerpheripheral surface of the filter chamber toward the outlet hole. A spiral projection can be also provided in place of the spiral groove. Therefore, when a suction pump is driven in order to prevent the filling or clogging of ink, the flow rate of the parts of the spiral grooves 6, 6 of the filter chamber becomes more than that of other part and, by this flow, counterclockwise flow is generated throughout the filter chamber 2 and air bubbles bonded to the inner wall surface of the filter chamber 2 are peeled to be discharged from the outlet hole 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet recording apparatus, and more particularly to an inkjet recording apparatus having a filter chamber.

[0002]

2. Description of the Related Art An ink jet recording apparatus uses an ink jet head having a plurality of nozzles for ejecting ink droplets and an actuator such as an electromechanical conversion element or a heating resistor provided corresponding to each nozzle. A high-speed, high-density, high-quality recording is performed by ejecting ink droplets from a nozzle onto a recording material (those to which ink droplets adhere) in accordance with a recording signal.

In such an ink jet recording apparatus, if, for example, bubbles, dust, etc. other than ink are present in the liquid chamber for ejecting ink droplets from the nozzles, clogging of the nozzles occurs and ink droplet ejection characteristics. (Injection characteristics)
For example, in a multi-nozzle type head that has a plurality of pressurized liquid chambers and ejects ink droplets from a plurality of nozzles, the ejection characteristics may vary depending on the presence or absence of bubbles, dust, etc. There is a problem that the characters and the image are disturbed and the image quality is deteriorated.

Therefore, there is a conventional method, for example, Japanese Patent Laid-Open No. 51-882.
In the ink jet recording apparatus described in Japanese Patent No. 24, a filter device 102 for removing foreign matters contained in the ink is arranged in the ink supply path 101 as shown in FIG. 7, and the filter device 102 is also provided. An air trap 103 for trapping air in the ink is provided on the upstream side of the air trap so that the air trapped by the air trap 103 can be discharged from the air vent device 104.

Further, in the ink jet recording apparatus disclosed in Japanese Patent Laid-Open No. 62-257857, as shown in FIGS. 9 and 10, the inlet of the filter chamber 111 having the filter 112 provided in the ink supply passage. Hole 113
Is formed at a position higher than the outlet hole 114,
Bubbles are prevented from being generated at the time of initial filling of the ink, and bubbles are prevented from flowing into the head from the outlet hole 114.

Further, in the conventional ink jet recording apparatus, when an ink cartridge is connected, the ink jet recording apparatus shown in FIG.
The ink is supplied by inserting the connecting pipe 121 as shown in 1 into the ink cartridge.

[0007]

However, in the conventional ink jet recording apparatus shown in FIG. 8 described above, when bubbles mixed in by the replacement of the ink cartridge or the like adhere to the filter of the filter device, It is difficult to separate the bubbles from the filter and collect them with the air collector, and it is impossible to collect all the bubbles.

Further, even in the ink jet recording apparatus shown in FIGS. 9 and 10, when bubbles adhere to the filter in the filter chamber or as shown in FIG. 11, bubbles B adhere to the inner wall surface of the filter chamber 111. If you did,
It is difficult to remove air bubbles.

Further, in the ink jet recording apparatus in which the ink cartridge is connected by using the connecting pipe shown in FIG. 11, due to the impact when the ink cartridge is replaced, as shown in FIG. B is often mixed in, and these bubbles flow into the head.

Particularly, in recent ink jet heads, the ink flow rate has increased due to the increase in the number of nozzles and the high frequency driving, and the nozzle diameter has become smaller due to the higher resolution, and the aperture diameter of the filter has also become smaller. for that reason,
Bubbles adhering to the inner wall surface of the filter chamber and the filter itself reduce the effective area of the filter, and it becomes impossible to secure the ink flow rate, which hinders the smooth supply of ink to the head and reduces the ejection characteristics of the head. Change and cause printing defects.

As described above, in the conventional ink jet recording apparatus, it is not possible to sufficiently prevent bubbles from being mixed into the ink and remove the mixed bubbles, and there is a problem that the image quality is deteriorated.

[0012]

In order to solve the above problems, an ink jet recording apparatus according to a first aspect of the present invention has an inlet hole and an outlet hole, and a filter is provided between the inlet hole and the outlet hole. In an ink jet recording apparatus in which a filter chamber is provided in the ink supply path, a spiral groove or protrusion is provided on the surface of the filter chamber facing the filter on the outlet hole side.

An ink jet recording apparatus according to a second aspect of the present invention is the ink jet recording apparatus according to the first aspect, wherein a spiral groove in a direction opposite to the outlet hole side is formed on a surface of the filter chamber facing the filter on the inlet hole side. Providing a protrusion.

According to another aspect of the present invention, there is provided an ink jet recording apparatus having an outlet hole connected to a head on one side and a filter chamber provided with a filter on the other side, and a replaceable ink cartridge is connected to a surface of the filter. In the above, a spiral groove or protrusion is provided on the surface of the filter chamber facing the filter on the outlet hole side.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view of a filter device of an ink jet recording apparatus showing a first embodiment of the present invention,
FIG. 2 is a side sectional view of FIG.

In this ink jet recording apparatus, a filter device 1 is provided in the ink supply path. In this filter device 1, a filter chamber 2 is formed inside, and a filter 3 for removing foreign matters and the like in the ink is provided in the filter chamber 2, and ink flows into the filter chamber 2 on the upstream side of the filter 3. An inlet hole 4 for forming the ink is formed, and an outlet hole 5 for forming the ink to flow out to the inkjet head side is formed on the downstream side of the filter 3.

The surface of the filter chamber 2 facing the filter 3 on the outlet hole 5 side is provided with spiral grooves 6 and 6. When the ink inside the filter chamber 2 flows out from the outlet hole 5, the spiral grooves 6 and 6 are rotated in the left direction (even in the right rotation direction) from the outer peripheral surface of the filter chamber 3 toward the outlet hole 5 with respect to the ink. Good)) is formed in the direction in which a spiral flow is generated. Instead of the spiral groove 6, a spiral protrusion may be provided.

With this construction, when the suction pump or the like is driven to fill ink or prevent clogging, the flow rate in the spiral grooves 6, 6 of the filter chamber 2 is greater than that in other sections. As the flow increases, a counterclockwise spiral flow is generated in the entire filter chamber 2 as indicated by an arrow in FIG. 2, and the spiral flow causes bubbles adhering to the inner wall surface of the filter chamber 2 and the filter 3 itself. Bubbles adhering to can be separated and discharged from the outlet hole 5. The bubbles flowing out from the outlet hole 5 are discharged from a bubble discharging dummy nozzle provided in the inkjet head, for example.

That is, when the spiral groove 6 is not provided on the surface 2a of the filter chamber 2 as shown in FIG. 3, the flow of the ink toward the outlet hole 5 becomes large as shown by the arrow, and the filter 3 Since almost no flow occurs at the peripheral edge of the filter and the inner wall surface of the filter chamber 2, the air bubbles adhering to the peripheral edge of the filter 3 remain as they are, the effective area of the filter 3 becomes small, and the filter 2 having a small flow flows. The bubbles B attached to the inner wall surface of the filter 3 remain as they are, and the effective area of the filter 3 is further reduced.

On the other hand, by generating a spiral flow in the filter chamber as in this embodiment, a large flow of ink can be generated in the entire filter chamber 2, and the peripheral edge of the filter 3 can be generated. The attached bubbles and the bubbles attached to the inner wall surface of the filter chamber 2 can be removed, and the entire surface of the filter 3 can be effectively used.

Therefore, a large number of nozzles, high frequency driving,
Even if the ink flow rate increases due to the high resolution and the opening diameter of the filter is small, the filter and the entire filter chamber can be effectively used, and a sufficient ink flow rate can be secured. As a result, the ink can be smoothly supplied to the head, the ejection characteristics of the head can be stabilized, and the image quality is improved.

Next, FIG. 4 is a sectional view of a main part of a filter device of an ink jet recording apparatus showing a first embodiment of the present invention, and FIG. 5 is a side sectional view of FIG. The filter device 11 of this ink jet recording apparatus is the same as the filter device 1 of the first embodiment except that the filter 3 on the inlet hole 4 side of the filter chamber 2 is provided.
Spiral grooves 7, 7 are formed on the surface 2b facing
Two flow path holes 4a and 4b branched from the inlet hole 4 are connected to the spiral grooves 7 and 7, respectively.

By forming the spiral grooves 7, 7 in a spiral shape in the direction opposite to that of the spiral grooves 6, 6 on the outlet side,
A flow in the same rotation direction as the rotation direction by the spiral grooves 6 and 6 is generated for the ink. In addition, the spiral groove 7
Alternatively, a spiral protrusion may be provided.

With this construction, when a suction pump or the like is driven to fill ink or prevent clogging, ink is filtered from the inlet hole 4 through the flow path holes 4a and 4b.
When flowing into the inside, a spiral flow in the left direction is generated by the spiral grooves 7, 7, and combined with the spiral flow in the left direction by the spiral grooves 6, 6 on the outlet hole 5 side, Since a spiral flow is generated in the whole 3, the bubbles adhering to the filter 3 itself and the air bubbles adhering to the inner wall surface of the filter chamber 2 are removed by the spiral flow, and the residual bubbles can be further reduced. Further, by using the degassed ink, the solubility of air bubbles in the ink is increased and residual air bubbles can be eliminated.

Next, FIG. 6 is an explanatory view of a main part showing a connecting portion with an ink cartridge of an ink jet recording apparatus showing a third embodiment of the present invention, and FIG. 7 is a sectional view of the filter apparatus of FIG. This ink jet recording apparatus has a nozzle portion 22 in which nozzles are formed on the entire surface of an ink jet head 21, and a filter device 24 is attached to a tip portion of a connection supply path 23 connected to the ink jet head 21. The ink jet head 21 has the ink absorber 2 of the ink cartridge 25 through the filter device 24.
The ink absorbed in 6 is supplied. An atmosphere opening hole 27 is formed in the upper part of the ink cartridge 25.

As shown in FIG. 7, the filter device 23 is provided with the filter 3 connected to the ink cartridge 25 on the front surface of the filter chamber 2, and the filter chamber 2 is connected to the ink jet head 21 via the connection supply path 23. The outlet hole 5 to be connected is formed, and a spiral groove 6 (or a protrusion) may be provided on the surface of the outlet hole 5 side facing the filter 3.

With this configuration, when the ink cartridge 25 is mounted, the ink absorber 27 inside and the filter 3 of the filter device 24 come into close contact with each other, and the ink absorbed by the ink absorber 27 causes the filter 3 to pass through. After passing through, the ink is supplied from the filter chamber 2 to the inkjet head 21 through the outlet hole 5.

At this time, even if there is a shock or the like when the ink cartridge is replaced, the capillary force of the filter 3 and the nozzle of the nozzle portion 22 prevents the ink from flowing out of the nozzle and the filter 3 and prevents the inclusion of air bubbles. Can be prevented. In addition, it is disturbing that the bubbles adhering to the inner wall surface of the filter 3 and the filter chamber 2 can be removed by generating a spiral flow by the spiral groove 6 as in the first and second embodiments.

[0029]

As described above, according to the ink jet recording apparatus of the first aspect, since the spiral groove or protrusion is provided on the surface of the filter chamber facing the filter on the outlet hole side, the spiral is formed in the filter chamber. -Like flow can be generated to remove bubbles adhering to the filter chamber and filter,
The ink flow rate can be sufficiently secured without increasing the filter area, residual bubbles can be reduced, and the image quality can be improved.

According to the ink jet recording apparatus of claim 2, in the ink jet recording apparatus of claim 1,
Since a spiral groove or protrusion in the direction opposite to the outlet hole side is provided on the surface of the filter chamber facing the filter on the inlet hole side, a spiral flow is generated for the ink from the inflow side to the filter chamber. The residual air bubbles can be further reduced, and the image quality can be improved.

According to another aspect of the present invention, there is provided an ink jet recording apparatus which has an outlet hole connected to the head on one side and a filter chamber provided with a filter on the other side, and which is connected to an ink cartridge replaceable on the filter surface. In the above, since a spiral groove or a protrusion is provided on the surface facing the filter on the outlet hole side, it is possible to prevent air bubbles from being mixed when the ink cartridge is replaced, and it is possible to more stably supply ink and to discharge air bubbles. Waste of ink due to the operation can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of an essential part of a filter device of an ink jet recording apparatus showing a first embodiment of the invention.

FIG. 2 is a side sectional view of FIG.

FIG. 3 is a cross-sectional view of a filter device having no spiral groove for explaining the operation of the first embodiment.

FIG. 4 is a cross-sectional view of an essential part of a filter device of an ink jet recording apparatus showing a second embodiment of the present invention.

FIG. 5 is a side sectional view of FIG. 4;

FIG. 6 is a principal part explanatory view showing a connecting portion with an ink cartridge of an ink jet recording apparatus showing a third embodiment of the invention.

7 is a cross-sectional view of the filter device of FIG.

FIG. 8 is an explanatory diagram showing an example of a conventional inkjet recording apparatus.

FIG. 9 is a cross-sectional view showing an example of a filter device of a conventional inkjet recording device.

FIG. 10 is a side sectional view of FIG.

FIG. 11 is a cross-sectional view showing a connection portion with an ink cartridge of a conventional inkjet recording device.

[Explanation of symbols]

1, 11, 24 ... Filter device, 2 ... Filter chamber, 3 ...
Filter, 4 ... Inlet hole, 5 ... Outlet hole, 6, 7 ... Spiral groove

Claims (3)

[Claims] 1. An ink jet recording apparatus in which a filter chamber having an inlet hole and an outlet hole and a filter provided between the inlet hole and the outlet hole is provided in an ink supply path.
An ink jet recording apparatus, wherein a spiral groove or a protrusion is provided on a surface of the filter chamber facing the filter on the outlet hole side. 2. The ink jet recording apparatus according to claim 1, wherein a spiral groove or a protrusion in a direction opposite to the outlet hole side is provided on a surface of the filter chamber facing the filter on the inlet hole side. Characteristic inkjet recording device. 3. An ink jet recording apparatus having a filter chamber having an outlet hole connected to a head on one side and a filter provided on the other side, and a replaceable ink cartridge is connected to a surface of the filter in the ink jet recording device. An ink jet recording apparatus, characterized in that a spiral groove or protrusion is provided on a surface of the hole facing the filter.