JP2006218680A - Liquid jetting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jetting apparatus capable of preventing a solid component included in an ink in a liquid passage from precipitating without uselessly a liquid such as the ink. <P>SOLUTION: The liquid jetting apparatus 10 comprises a liquid jetting head 30 with a nozzle 55A for jetting the liquid or the like, a liquid storing part 2 for storing the liquid or the like, the liquid passage for feeding the liquid to the nozzle 55A or the like from the liquid storing part 2 or the like, and a liquid agitating means 70 floating in the liquid in the liquid passage and moving in the liquid accompanied with flow of the liquid to agitate the liquid. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid ejecting apparatus that ejects liquid.

As a liquid ejecting apparatus that ejects liquid onto a target, an ink jet recording apparatus that performs printing by ejecting ink droplets from a recording head onto a recording medium is known.
Such an ink jet recording apparatus includes an ink jet recording head that receives ink supplied from an ink cartridge, and a paper feeding unit that moves the recording paper relative to the recording head. By moving ink droplets from the nozzles of the recording head to the recording medium while moving in the width direction of the recording paper, an image such as a desired character or graphic is recorded.
In addition, a filter chamber having a filter is provided at a connection portion between the above-described ink cartridge and the ink jet recording head in order to remove foreign matters mixed in the ink (for example, Patent Document 1).

If the ink jet recording apparatus is not used for a long time, the ink stays in the filter chamber, and a solid component such as a pigment dissolved in the ink precipitates on the filter. For this reason, the ink in the filter chamber loses its solid component and becomes different from the original property, and when printing is performed after being left unattended, there is a problem that color unevenness occurs or ink ejection failure occurs. It was.
In addition, when the amount of precipitated solid components is large, there is a problem that the filter is clogged and the amount of ink supplied to the recording head is reduced, resulting in poor ink ejection.

In order to prevent such a problem, maintenance cleaning for forcibly sucking ink from the nozzles of the recording head with a suction pump or the like and replacing the ink in the filter chamber is regularly performed.
Japanese Unexamined Patent Publication No. 2004-122398 (FIG. 1 etc.)

  However, there is a problem that the ink existing in the liquid passage and the nozzles of the recording head may be wasted due to the maintenance cleaning described above.

  Accordingly, an object of the present invention is to provide a liquid ejecting apparatus capable of solving the above-described problems and preventing precipitation of solid components contained in ink in a liquid passage without wastefully discharging liquid such as ink. Yes.

  The liquid ejecting apparatus of the present invention made to achieve the above object includes a liquid ejecting head having a nozzle for ejecting liquid, a liquid storing unit storing the liquid, and the liquid storing unit from the liquid storing unit. A liquid passage for supplying to the nozzle; and a liquid agitating means that floats in the liquid in the liquid passage and moves in the liquid as the liquid flows to agitate the liquid. To do.

Liquid agitating means is suspended in the liquid existing in the liquid passage of the liquid ejecting apparatus. When the nozzle of the liquid ejecting apparatus starts ejecting the liquid, the liquid agitating means moves as the liquid flows. A vortex is generated around the liquid stirring means moving in the liquid due to the resistance of the liquid, and the liquid is stirred. Solid components, such as pigments, that have settled at the bottom of the liquid passage are wound up by the vortex and diffuse into the liquid.
With such a configuration, according to the liquid ejecting apparatus of the present invention, it is possible to prevent the solid component in the liquid from being precipitated without wasting the liquid due to forced suction of the liquid or the like.

Here, it is preferable that the liquid passage has a filter chamber provided with a filter for filtering the liquid foreign matter, and the liquid stirring means is disposed in the filter chamber.
Due to such a configuration, the liquid stirring means can diffuse the solid matter precipitated on the filter into the liquid and prevent the filter from being clogged.

In addition, the shape of the liquid stirring means is preferably a shape including a corner portion.
Since it is comprised in this way, the vortex which arises with the movement of a liquid stirring means can be generated effectively, and a high stirring effect can be acquired.

The liquid stirring means preferably has a plurality of protrusions on the surface thereof.
Since it is comprised in this way, the vortex which arises with the movement of a liquid stirring means can be generated effectively, and a high stirring effect can be acquired.

Moreover, it is desirable that the liquid stirring means has a hollow portion.
Since it is configured in this manner, the specific gravity of the entire liquid agitation means can be adjusted by changing the size of the hollow portion, and the liquid agitation means can be configured with a material having a specific gravity greater than that of the liquid. .

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
The embodiments described below are preferred specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these embodiments.

FIG. 1 is a schematic view showing an ink jet recording apparatus 10 and the like according to the first embodiment of the present invention.
An ink jet recording apparatus 10 shown in FIG. 1 is an example of a liquid ejecting apparatus, and is also called an ink jet printer. The ink jet recording apparatus 10 has a main body 1. The main body 1 includes a platen 12, a carriage 14, a guide rail 17, an ink cleaning device 20, and a recording head 30. The recording head 30 is an example of a liquid ejecting head and is also called a print head.

An ink jet recording apparatus 10 shown in FIG. 1 is a so-called on-carriage recording apparatus, and a plurality of ink cartridges 2, 3, 4, and 5 are detachably mounted on an upper portion of a carriage 14. The recording head 30 described above is provided below the carriage 14.
A liquid, for example, ink is stored in the ink cartridge 2 or the like. That is, the ink cartridge 2 is an example of a liquid storage unit.
The carriage 14 is connected to the motor 16 via an endless belt 15 that is engaged with the pulley 19A and the pulley 19B. When the motor 16 operates, the carriage 14 and the recording head 30 reciprocate linearly along the guide rail 17 in the main scanning direction T that is the axial direction of the platen 12.

A home position 18 is located in a non-printing area that is one end of the guide rail 17. An ink cleaning device 20 is disposed on the main body 1 at the home position 18. The ink cleaning device 20 is an example of a liquid cleaning device and is also called a capping system or a capping unit.
If bubbles are mixed in a filter chamber 65 (see FIG. 3), which will be described later, or if dissolved gas exists in the ink and grows into bubbles, the normal flow of ink may be hindered. In some cases, a solid component, for example, a pigment contained in the ink is precipitated, and the component of the ink staying in the ink chamber is deteriorated.
In such a case, the ink cleaning device 20 seals a later-described nozzle plate surface 61 (see FIG. 2) and applies negative pressure from the suction pump 19 to later-described nozzle openings 55A to 55D (see FIG. 2). The ink is forcibly sucked and discharged from the nozzle openings 55A to 55D, and the ink is forcibly discharged to perform maintenance cleaning.

FIG. 2 is a schematic cross-sectional view showing a structural example of the recording head 30 shown in FIG.
In particular, when the ink jet recording apparatus 10 is used as a color printer, the recording head 30 has an independent ink path 50 for each ink type in order to eject a plurality of different types of ink. Yes.

Ink from each of the ink cartridges 2, 3, 4, and 5 flows into the ink path 50 through the ink supply needle 50A. Ink paths 50 independent for each type of ink are connected to a plurality of pressure chambers 51, respectively. Each nozzle opening row 54 </ b> A to 54 </ b> D is connected to each pressure chamber 51. The ink droplets pushed out from the pressure chamber 51 are ejected from the nozzle openings 55A to 55D of the nozzle opening rows 54A to 54D provided on the nozzle plate surface 61. The nozzle openings 55A to 55D are examples of nozzles.
The interior of the ink supply needle 50A, the ink path 50, and the pressure chamber 51 are paths that supply ink from the ink cartridges 2 to 5 to the nozzle openings 55A to 55D, and are examples of liquid paths.
The recording head 30 linearly reciprocates in the main scanning direction T in FIG. 1 while ejecting ink from the nozzle openings 55 </ b> A to 55 </ b> D, whereby characters and the like can be recorded on a recording medium such as the paper 29.

FIG. 3 is a schematic enlarged view of a broken line portion P in FIG.
As shown in FIG. 3, a filter chamber 65 is formed at the connecting portion between the ink supply needle 50A and the recording head 30, and a filter 63 is disposed to remove foreign matters and bubbles in the ink. The filter 63 is made of, for example, a metal mesh, but may be made of a nonwoven fabric or the like.
As shown in FIG. 3, the filter chamber 65 has a first filter chamber 65a disposed on the side of the ink cartridge 2 and the like inside the ink supply needle 50A with the filter 63 as a boundary, and the nozzle openings 55A to 55D side. Has a second filter chamber 65b.
As shown in FIG. 3, at least one stirring floating body 70 is disposed in the first filter chamber 65a. The stirring floating body 70 is an example of a liquid stirring means that stirs ink by floating in the ink as the ink flows.

4 and 5 are schematic diagrams for explaining the operation of the stirring floating body 70. FIG.
An opening 66 is provided above the ink supply needle 50A. When printing is started, the ink flows into the first filter chamber 65a from the opening 66, and flows downward, for example, along the streamline R1 in FIG. When the streamline R1 reaches the filter 63, most of the ink flowing along the streamline R1 passes through the filter 63 and flows into the second filter chamber 65 along the streamline R2. A part of the ink flow is reflected by the filter 63 and flows upward along the streamline R3.
While the printing is being performed, the agitation floating body 70 moves in the first filter chamber 65a in such a flow of ink.
On the filter 63, the printing operation is stopped, and the solid matter 72 that has precipitated while the ink stayed in the filter chamber 65 is attached.

FIG. 5 is an enlarged view of a broken line portion Q in FIG. A state in which the agitation floating body 70 has moved to the vicinity of the filter 63 on the ink flow is shown. The agitation floating body 70 receives the resistance of ink as it moves, and a large number of vortices 73 are generated below it (downstream of the streamline R1).
The vortex 73 impinges on the solid 72 that has settled on the filter 63 and causes the solid 72 to roll up and diffuse into the ink.

FIG. 6 is a schematic diagram illustrating an example of the shape of the stirring floating body 70.
As described above, since the stirring floating body 70 performs stirring using the disturbance of the ink flow, it is desirable that the stirring floating body 70 has a shape that easily receives ink resistance.
FIG. 6A shows a stirring floating body 70a having a rectangular parallelepiped shape. The agitation floating body 70 a has twelve angled angle portions 80.
FIG. 6B shows a stirring floating body 70b having a triangular pyramid shape. The agitation floating body 70b has six angled portions 81.
A stirring floating body 70c shown in FIG. 6C has a substantially spherical main body 82, and a large number of protrusions 83 are provided on the surface thereof.
The material of the stirring floating body 70 is preferably a material that does not easily cause a chemical reaction with ink, such as polypropylene, polyethylene, polystyrene, or the like.

FIG. 7 is a schematic view showing an example of a stirring floating body having a hollow portion.
7A is a side view of the stirring floating body 70d, and FIG. 7B is a cross-sectional view taken along the line AA in FIG. 7A. The external appearance of the stirring floating body 70d has a substantially cylindrical shape in which both end portions are reduced in diameter and blocked. The inside of the partition wall 84 is a cavity 85, in which air is enclosed. The cavity 85 is an example of a hollow part.

If the specific gravity of the agitation floating body is significantly different from that of the ink, the agitation floating body is biased to the upper part (the opening 66 side in FIG. 4) or the lower part (the filter 63 side in FIG. 4). It will not float according to the ink flow. In this case, the ink flow is inhibited, and the effect of diffusing the solid matter precipitated in the filter 63 by stirring the ink cannot be sufficiently obtained.
Therefore, the specific gravity of the stirring floating body 70 needs to be a value close to the specific gravity of the ink. The shape of the stirrer floating body may be a solid shape and the material may have a specific gravity close to the specific gravity of the ink. However, if the stirrer floating body has a hollow portion like the stirrer floating body 70d in FIG. By adjusting the thickness t, the specific gravity as a whole can be adjusted. For this reason, it is possible to form a stirring suspension using a material having a specific gravity much larger than that of ink, for example, metal.

(Second Embodiment)
Next, the ink jet recording apparatus 100 of the second embodiment will be described. The ink jet recording apparatus 100 according to the second embodiment has many configurations in common with the ink jet recording apparatus 10 according to the first embodiment, and thus common parts are denoted by the same reference numerals, and the description thereof is omitted. The difference will be mainly described.

FIG. 8 is a schematic plan view showing the ink jet recording apparatus 100.
As shown in FIG. 8, the ink jet recording apparatus 100 is different from the ink jet recording apparatus 10 of the first embodiment in that the ink cartridge 105 is not mounted on the carriage 102, and further includes a cleaning unit 117 and a capping unit 118. It is arranged on the outside (right side in FIG. 8). The ink stored in the ink cartridge 105 is configured to be supplied to the recording head 104 via the ink supply tube 107 and the pressure damper 106.

FIG. 9 is a schematic cross-sectional view of the pressure damper 106 taken along line BB (see FIG. 8).
As shown in FIG. 9, the pressure damper 106 includes a base portion 161 having a concave space 160, an elastic sheet 164 that is a partition wall that isolates the space 160 from the outside, and a connection flow path 168 that communicates with the recording head 104. . A filter 165 is disposed at a connection portion between the space 160 and the connection flow path 168.
As the above-described elastic sheet 164 is deformed according to the ink pressure fluctuation, the pressure damper can absorb the ink pressure fluctuation.

As shown in FIG. 9, the ink jet recording apparatus 100 stores at least one stirring floating body 70 (see FIG. 4) in a space 160 of the pressure damper 106.
The stirring floating body 70 moves along with the ink flow, stirs the ink, and diffuses the solid matter 72 that has settled on the bottom 162 into the ink again.

  The present invention is not limited to the above embodiment as an ink jet recording apparatus, and various modifications can be made without departing from the scope of the claims. Furthermore, the above-described embodiments may be combined with each other. Further, the present invention is not limited to an ink jet recording apparatus, but a recording head used in an image recording apparatus such as a printer, a color material ejection head used in manufacturing a color filter such as a liquid crystal display, an organic EL display, and an FED (surface emitting). Electrode material ejection heads used for electrode formation such as displays), liquid ejection devices using liquid ejection heads that eject liquids such as bio-organic matter ejection heads used in biochip manufacturing, sample ejection devices as precision pipettes, etc. Applicable.

  The present invention is not limited to the embodiments described above. Furthermore, the above-described embodiments may be combined with each other.

1 is a schematic diagram illustrating an ink jet recording apparatus according to an embodiment of the present invention. It is a schematic sectional drawing which shows the structural example of a recording head. It is a schematic enlarged view of the broken-line part P of FIG. It is the schematic explaining the ink stirring operation | movement of the floating body for stirring. It is a schematic enlarged view of the broken-line part Q of FIG. It is the schematic which shows the example of a shape of the floating body for stirring. It is the schematic which shows the example of a shape of the floating body for stirring. FIG. 4 is a schematic plan view showing an ink jet recording apparatus according to a second embodiment of the present invention. It is a BB line (refer to Drawing 8) schematic sectional view of a pressure damper.

Explanation of symbols

2, 3, 4, 5... Ink cartridge (an example of a liquid storage unit) 10, 100... An ink jet recording apparatus (an example of a liquid ejecting apparatus), 30. ), 50... Ink path, 50 A ink supply needle, 63... Filter, 65... Filter chamber, 65 a... First filter chamber, 65 b. Floating body (an example of liquid stirring means), 72 ... solid matter

Claims (5)

A liquid ejecting head having a nozzle for ejecting liquid;
A liquid storage section storing the liquid;
A liquid passage for supplying the liquid from the liquid reservoir to the nozzle;
A liquid ejecting apparatus comprising: liquid agitating means that floats in the liquid in the liquid passage and moves in the liquid as the liquid flows to agitate the liquid. The liquid passage has a filter chamber including a filter for filtering the liquid foreign matter,
The liquid ejecting apparatus according to claim 1, wherein the liquid agitating unit is disposed in the filter chamber.   The liquid ejecting apparatus according to claim 1, wherein the shape of the liquid agitating unit is a shape including an angled portion.   The liquid ejecting apparatus according to claim 1, wherein the liquid stirring unit has a plurality of protrusions on a surface thereof.   The liquid ejecting apparatus according to claim 1, wherein the liquid stirring unit has a hollow portion.

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