JP2000062203A - Ink jet recording device - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] An ink jet recording apparatus in which a pressure loss is reduced by preventing a decrease in a flow rate of ink in a filter section. SOLUTION: A filter 15 provided in a flow path between an ink jet recording head and ink supply means for supplying ink to the ink jet recording head has a substantially elliptical shape, and a first flow of the filter 15 is provided. The path 16 is a filter 15
And the second flow path 17 of the filter 15 is provided to face the other end of the filter 15, and the first flow path 1
In the first filter chamber 18 communicating with the filter 6, the wall surface defining the first filter chamber 18 is formed close to the filter surface except at one end of the filter 15 and its vicinity, and on the other side of the filter 15. A second filter chamber 19 that is formed and communicates with the second flow path 17 is provided in the entire area of the filter 15 so as to form a flow path along the surface of the filter 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus provided with a filter provided between an ink jet recording head and an ink supply means for removing foreign matters and bubbles in ink.

[0002]

2. Description of the Related Art Generally, in an ink jet recording head, ink is supplied from an ink cartridge filled with the ink through an ink supply needle and a flow path inserted into the ink cartridge, and the supplied ink is a piezoelectric element. It is ejected from the nozzle by driving the nozzles.

In such an ink jet type recording head, foreign matter existing in the ink of the ink cartridge, or foreign matter mixed in the ink due to adhesion to the ink supply needle or the like is supplied when the ink cartridge is attached or detached. Then, there is a problem that ejection failure occurs.
In addition, there is a problem in that ejection failure similarly occurs due to bubbles existing in the ink. Therefore, usually, a filter having a plurality of fine holes for removing foreign matters and bubbles in the ink is attached to the ink flow path between the ink cartridge and the ink jet recording head.

In such a filter section, pressure loss increases due to resistance in the flow of ink. For this reason, for ink colors for which the printing speed is desired to be high, particularly for black, the speed of the ink flowing in the flow path is high, and it is necessary to take a large filter area in order to suppress the pressure loss to a certain level or less. Therefore, the flow path may be offset before and after the filter.

For example, the case shown in FIG. In this case, the filter 01 has an elliptical shape and includes an ink supply needle 03 having a flow path 02 inserted into an ink supply hole of an ink cartridge (not shown), the ink supply needle 03, and an inkjet recording head (not shown). Communication channel 0
It is fixed between the head case 05 and the head case 05. The flow channel 02 in the ink supply needle 03 communicates with one end of the filter 01 in a state of being orthogonal to the one end, and the flow channel 04 of the head case 05 communicates with the other end of the filter 01 with an inclination.

[0006]

In the above-mentioned structure, there is a problem that the flow velocity becomes small because the cross-sectional area of the flow channel rapidly expands when the ink moves from the flow channel 02 to the first filter chamber. On the upstream side of the filter 01 with which the path 04 communicates, that is, the flow path 04 inside the ink supply needle 03.
There is a problem that the bubbles g are likely to be accumulated on the communication side of and the pressure loss becomes large.

In view of such circumstances, it is an object of the present invention to provide an ink jet type recording apparatus in which the flow velocity of ink in the filter portion is prevented from decreasing and the pressure loss is reduced.

[0008]

According to a first aspect of the present invention which solves the above problems, an ink jet recording head having a plurality of nozzles for ejecting ink droplets, and an ink for supplying ink to the ink jet recording head. In an ink jet recording apparatus including a supply unit and a filter provided in a flow path between them, the filter has a substantially oval shape, and the first flow path on one side of the filter is the filter. While facing the one end of the filter, the second flow path on the other side of the filter is provided to face the other end of the filter, and is formed on the one side of the filter to form the first flow path. The first filter chamber communicating with the filter is formed in a hemispherical shape at the one end of the filter and in the vicinity thereof, and the wall surface defining the first filter chamber is provided at a position other than the one end and the vicinity thereof. A second filter chamber that is formed close to the filter surface and that is formed on the other side of the filter and that communicates with the second flow path, has a flow path extending along the surface of the filter over the entire area of the filter. The inkjet recording apparatus is characterized in that it is provided so as to form

In the first aspect, a flow passage is formed which passes through the filter from the first flow passage via the first filter chamber and then flows to the second flow passage via the second filter chamber. Since the flow passage cross section does not suddenly widen when moving from the first flow passage to the first filter chamber and the ink flow velocity does not decrease greatly, large ink bubbles are not formed on the flow passage side and stable ink supply can be realized. .

A second aspect of the present invention is the ink jet printer according to the first aspect, characterized in that the second filter chamber extends substantially parallel to the entire area of the filter at substantially equal distances. It is in a type recording device.

In the second aspect, when the ink from the first filter chamber passes through the filter, the flow concentrates on one end portion of the filter, so that the flow is achieved by expanding the front side of the second filter chamber on the receiving side. Is smooth and pressure loss can be reduced.

According to a third aspect of the present invention, in the first or second aspect, among the wall surfaces defining the second filter chamber,
According to another aspect of the invention, there is provided an ink jet recording apparatus having a top surface formed of the filter.

In the third aspect, the top surface of the wall surface defining the second filter chamber is made of metal such as stainless steel, the wettability with ink is improved, and the probability that bubbles adhere to the wall surface is reduced. .

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on embodiments.

(First Embodiment) FIG. 1 is a sectional view of a recording unit of an ink jet recording apparatus according to a first embodiment of the present invention, and FIG. 2 is a sectional view showing a fixed portion of a filter.

As shown in FIG. 1, the recording unit 10 includes a frame 11 constituting an outer frame of the recording unit 10.
And an ink supply needle 13 inserted into the ink supply hole 12a of the ink cartridge 12, and a head case 14 provided between the ink jet recording head 20 and the ink supply needle 13, the ink supply needle 13 and the head. An oval filter 15 is provided between the case 14 and the case 14.

Here, as shown in FIG. 2, the ink supply needle 13 is provided with a flow path 16 extending in a direction substantially orthogonal to the filter 15 and facing the left end portion of the filter 15 in the figure, while the head is provided. The case 14 has a flow path 17 that is inclined to the filter 15 and faces the right end of the filter 15 in the drawing.
Are formed, and the flow paths 16 and 17 are in an offset state. In addition, the flow path 16 communicates with a hemispherical filter chamber 18 whose diameter gradually increases toward the filter 15. The filter chamber 18 is only opened at the left end portion of the filter 15 in the figure, and the inner surface 13 a of the central portion (right side in the figure) of the hemispherical filter chamber 18 is adjacent to the filter 15 and extends along the filter 15. It is provided so that there is almost no gap near the filter 15. On the other hand, the flow path 17
Communicates with a filter chamber 19 formed on the downstream side of the filter 15, and the inner wall 14a of the head case 14 that defines the filter chamber 19 extends substantially parallel to the filter 15 at substantially the same distance. There is. Further, the top surface side is entirely defined by the filter 15.

FIG. 3 shows an ink jet recording head 2.
An example of 0 is shown. As shown in the figure, the elastic film 33 is formed on one surface of the flow path forming substrate 32 in which the pressure generating chamber 31 is formed.
Are formed. The lower electrode film 3 is formed on the elastic film 33.
4, the piezoelectric film 35 and the upper electrode film 36 are laminated and patterned to form the piezoelectric element 300 for each pressure generating chamber 31.

On the other hand, on the other surface side of the flow path forming substrate 32,
A nozzle forming substrate 45 having a nozzle 45a is provided, and a nozzle communication hole 46 that communicates the nozzle 45a and the pressure generating chamber 31 has a sealing plate 41, an ink chamber side plate 42, a thin plate 43, and a common ink chamber formation. It is arranged so as to penetrate the substrate 44.

These substrates are fixed via an adhesive layer 49, respectively, and the thin wall 43 and the common ink chamber forming substrate 4 are provided.
A common ink chamber 47 is formed by the nozzle 4 and the nozzle forming substrate 45. The common ink chamber 47 and each pressure generating chamber 31 are provided with a sealing plate 41, an ink chamber side plate 42, and a thin wall 43.
Through an ink supply communication hole 48 formed through the ink supply port, and the sealing plate 41 has an ink introduction port (not shown) for receiving ink from the outside into the common ink chamber 47. . The ink introduction port is connected to the ink flow path 7 of the head case 1 and communicates with, for example, an ink cartridge. In addition, an opening 42a is formed in the ink chamber side plate 42 at a portion facing the common ink chamber 47. The thin wall 43 in the opening 42a portion absorbs the pressure generated when ejecting ink toward the side opposite to the nozzle 45a, and the unnecessary positive or negative pressure is passed to the other pressure generating chamber 31 via the common ink chamber 47. It prevents the application of negative pressure.

In such an ink jet recording head, ink is supplied from the ink inlet to the common ink chamber 47, and each pressure generating chamber 31 is supplied through the ink supply communication hole 48.
Will be distributed to. Then, after filling the interior up to the nozzle 45a with ink, a voltage is applied between the lower electrode film 34 and the upper electrode film 36 in accordance with a recording signal from an external drive circuit (not shown), and the elastic film 33, By bending and deforming the electrode film 34 and the piezoelectric film 35, the pressure in the pressure generating chamber 31 is increased and ink is ejected from the nozzle 45a.

At this time, the ink supplied from the ink cartridge (not shown) and flowing into the filter chamber 18 from the flow path 16 of the ink supply needle 13 passes through the filter 15 as it is and enters the filter chamber 19 to pass through the filter chamber 19. It enters into the flow path 17 through. When the ink is first filled, as shown in FIG. 2, bubbles g remain between the filter 15 of the ink supply needle 13 and the inner surface 13a, but there is almost no volume in this portion, and bubbles remaining after filling. Is small. Further, since the change in the flow passage area when moving from the flow passage 16 to the filter chamber 18 is small, the decrease in the ink flow velocity is small and the amount of bubbles remaining as a result is reduced to reduce the pressure loss. When the flow paths offset from each other are provided through the filter having the substantially oval shape, the flow path width is minimized except for the portion facing the flow path on one side, and the filter is provided on the other side. By forming the flow path along the flow path, the flow velocity can be maximized and the pressure loss due to the remaining bubbles can be reduced.

In the above-mentioned example, the flow path on the upstream side of the filter is made substantially orthogonal to the filter and the flow path on the downstream side is inclined, but the present invention is not limited to this. That is, the arrangement may be reversed, and both may be orthogonal or both may be inclined.

[0024]

As described above, according to the present invention,
When channels are provided that are offset from each other through a filter having a substantially oval shape, the channels on one side are minimized except for the portions facing the channels, and on the other side, along the filter. By forming the flow path by using such a flow path, it is possible to maximize the flow velocity and reduce the pressure loss due to the remaining bubbles.

[Brief description of drawings]

FIG. 1 is a sectional view of a recording unit using a filter according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a fixed portion of the filter according to the first embodiment.

FIG. 3 is a cross-sectional view showing an example of an inkjet recording head.

FIG. 4 is a cross-sectional view showing a fixed portion of a conventional filter.

[Explanation of symbols]

13 Ink supply needle 14 head case 15 filters 16, 17 channels 18, 19 Filter room g bubbles

Claims (3)

[Claims] 1. An ink jet recording head having a plurality of nozzles for ejecting ink droplets, an ink supply means for supplying ink to the ink jet recording head, and a filter provided in a flow path therebetween. In the ink jet recording apparatus, the filter has a substantially oval shape, and the first flow path on one side of the filter faces one end of the filter and the second flow path on the other side of the filter. The first filter chamber, which is provided on the one side of the filter and communicates with the first flow path, is provided so as to face the other end of the filter, and the first filter chamber includes the one end of the filter and the vicinity thereof. A wall surface that is formed in a hemispherical shape and that defines the first filter chamber is formed close to the filter surface except at the one end portion and in the vicinity thereof, while the other of the filter An ink jet system characterized in that a second filter chamber formed on the side and communicating with the second flow passage is provided so as to form a flow passage along the surface of the filter over the entire area of the filter. Recording device. 2. The ink jet recording apparatus according to claim 1, wherein the second filter chamber is extended substantially in parallel over the entire area of the filter at a substantially equal distance. 3. The ink jet recording apparatus according to claim 1, wherein a top surface of the wall surface defining the second filter chamber is formed of the filter.