JP2002160379A - Ink supply device for inkjet recording device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To make it possible to more stably supply an ink liquid to a print head 6 with a simple configuration. SOLUTION: A first liquid supply pipe 1 formed in a loop shape.
A fluid that absorbs pressure fluctuations of the ink liquid flowing in the second liquid supply pipe 13b is provided at an intermediate position of the second liquid supply pipe 13b extending so as to be joined to the print head 6 by merging the third liquid supply pipe 3a. By arranging the pressure relaxing means 13d, the ink liquid in the second liquid supply pipe 13b is sent to the print head 6 side while maintaining a substantially constant pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink supply apparatus for an ink jet recording apparatus which supplies an ink liquid stored in an ink supply source to a print head via a liquid supply pipe arranged in a loop. .

[0002]

2. Description of the Related Art In an ink jet recording apparatus used as an output device of a computer or a workstation, for example, as shown in FIG. 6 showing an embodiment of the present invention, the apparatus is provided so as to reciprocate. The print head 6 is held on the carriage 5, and the print head 6 scans in a direction substantially perpendicular to the recording paper conveyance direction (not shown) as the carriage 5 reciprocates. ing. On the other hand, the ink liquid stored in the ink tank 7 serving as an ink supply source is sent to the print head 6 through liquid supply pipes 11 and 13 extending from the ink tank 7, and the print head 6 prints the recording liquid. Printing is performed by discharging ink droplets on paper.

At this time, when the print head 6 scans and moves, a pressure fluctuation occurs in the ink liquid in the liquid supply pipe 13 due to a moving inertia force of the print head 6, and the print fluctuation is caused by the pressure fluctuation of the ink liquid. The ink ejection state of the head 6 may become unstable. For this reason, conventionally, a liquid supply pipe 13 formed in a loop shape has been proposed.

In this device, a first loop-shaped first member is formed.
The ink liquid in the first liquid supply pipe 13a having a loop shape is made to flow in an annular shape in the liquid supply pipe 13a, and the ink liquid in the loop-shaped first liquid supply pipe 13a is joined to the terminal position of the first liquid supply pipe 13a. The liquid is supplied to the print head 6 through the second liquid supply pipe 13b. According to the ink supply device including the first liquid supply pipe 13a formed in such a loop shape, even if the pressure fluctuation occurs in the ink liquid in the first liquid supply pipe 13a, Second
At the joint 14 into which the ink liquid flows into the liquid supply pipe 13b, the pressure of the upstream ink liquid flowing into the second liquid supply pipe 13b and the liquid liquid flowing out from the second liquid supply pipe 13b. Therefore, the pressure of the ink liquid on the downstream side cancels each other, and as a result, the above-described fluctuation in the pressure of the ink liquid is eliminated.

[0005]

However, even if the pressure fluctuation is eliminated by adopting a loop structure in the first liquid supply pipe 13a as described above, the second liquid is not affected by the scan of the print head 6. Since the supply pipe 13b reciprocates integrally with the print head 6, a pressure fluctuation also occurs in the second liquid supply pipe 13b, and the pressure fluctuation in the second liquid supply pipe 13b is reduced. This may affect the ejection state of the print head 6. For example, when the print head 6 is scanning and moving at high speed, and suddenly reversed at the scanning end,
An extremely large pressure fluctuation occurs in the ink liquid in the second liquid supply pipe 13b. If a positive pressure fluctuation occurs in the second liquid supply pipe 13b, a situation occurs in which the ink liquid is ejected even when a print signal is not applied to the print head 6. Conversely, when a negative pressure fluctuation occurs in the second liquid supply pipe 13b, bubbles are sucked into the print head 6 and the ejection of the ink liquid becomes unstable or May result in disabled state.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink supply apparatus for an ink jet recording apparatus which can supply an ink liquid to a print head more stably with a simple structure. I do.

[0007]

According to a first aspect of the present invention, there is provided an ink supply apparatus for an ink jet recording apparatus, comprising: a print head for discharging ink; and a paper transport direction while holding the print head. A carriage that scans and moves in a direction substantially orthogonal to a liquid supply pipe that transfers the ink liquid stored in the ink supply source to the print head,
In the ink supply device of an ink jet recording apparatus provided with: a first liquid supply tube formed in a loop so as to make the ink liquid sent from the ink supply source flow in an annular shape; A second liquid supply pipe that is connected so as to merge at both ends of the flow path of the first liquid supply pipe and guides the ink liquid in the first liquid supply pipe to the print head. Fluid pressure reducing means for absorbing pressure fluctuations of the ink liquid flowing in the second liquid supply pipe is arranged at a position in the flow path of the second liquid supply pipe.

According to the ink supply device of the ink jet recording apparatus according to the first aspect having the above-mentioned structure, since the ink supply device is not formed in a loop shape, it is susceptible to pressure fluctuation.
The ink liquid in the liquid supply pipe is sent to the print head side while being kept at a substantially constant pressure by the fluid pressure relaxation means.

According to a second aspect of the present invention, there is provided an ink supply apparatus for an ink jet recording apparatus, wherein the fluid pressure reducing means according to the first aspect is substantially parallel to a scanning direction of a print head of the second liquid supply pipe. Are arranged in a portion extending to

According to the ink supply apparatus of the ink jet recording apparatus having the above-described configuration, the second liquid supply pipe extends substantially in parallel with the scanning direction of the print head. The ink liquid in the portion which is easily affected by the pressure fluctuation is sent to the print head side while being maintained at a substantially constant pressure by the fluid pressure relaxation means.

Further, in the ink supply device of the ink jet recording apparatus according to the third aspect, the fluid pressure relaxing means according to the first aspect extends while meandering in a direction inclined with respect to the scanning direction of the print head. It consists of a continuous meandering tube.

According to the ink supply apparatus of the ink jet recording apparatus having the above-mentioned structure, the ink supply apparatus is not formed in a loop shape, and therefore is susceptible to pressure fluctuation.
The ink liquid in the liquid supply pipe flows in the continuous meandering pipe constituting the fluid pressure relieving means while meandering in a direction inclined to the scanning direction. Is reduced, and
The amount of pressure fluctuation that occurs with respect to the velocity component of the ink liquid in the scanning direction is also reliably reduced.

Further, in the ink supply apparatus for an ink jet recording apparatus according to the fourth aspect, the fluid pressure relaxing means according to the first aspect has a small diameter having an inner diameter smaller than an inner diameter of the second liquid supply pipe. It consists of a radial channel tube.

According to the ink supply apparatus of the ink jet recording apparatus having the above-described structure, since the ink supply apparatus is not formed in a loop, the second apparatus is susceptible to pressure fluctuation.
The ink liquid in the liquid supply pipe is sent to the print head side while being kept at a substantially constant pressure by the fluid pressure relieving means comprising a small-diameter flow path pipe.

According to a fifth aspect of the present invention, in the ink supply device for an ink jet recording apparatus, the fluid pressure reducing means according to the first aspect is arranged so as to extend in a direction substantially orthogonal to a scanning direction of the print head. It is composed of commissures.

According to the ink supply apparatus for an ink jet recording apparatus having the above configuration, the ink liquid flowing in the orthogonal pipe constituting the second liquid supply pipe has a velocity in the scanning direction. Since there is almost no component, there is almost no pressure fluctuation amount that occurs with respect to the velocity component of the ink liquid in the scanning direction, and the ink liquid is stably sent to the print head by that much.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 5 shows an inkjet printer (hereinafter simply referred to as a printer) as an example of a suitable image forming apparatus to which the present invention is applied.

In the ink jet printer 1 shown in FIG. 5, a carriage is mounted on a pair of guide shafts 4 and 4 arranged on a platen 3 for transporting the recording paper 2 via slide bearings (not shown). 5 is reciprocally supported and its carriage 5
Is equipped with a print head 6 as recording means. Then, the carriage 5 is driven by a driving force of a carriage motor (not shown) to move the guide shaft 4,
4, the print head 6 is configured to be driven in the directions of arrows R and L (main scanning direction) in the figure.

At this time, a liquid supply pipe (not shown) extending from an ink tank 7 attached to the side of the apparatus is connected to the print head 6 as an ink supply source. The ink liquid to be printed is ejected from the ink ejection holes of the print head 6 in accordance with the print data, thereby printing on the recording medium 2 conveyed in the sub-scanning direction below the print head 6. Is performed.

On the other hand, between the ink tank 7 and the print head 6, as shown in FIG. 6, a fixed liquid supply pipe 11 extending from the ink tank 7 and a fixed liquid supply pipe 11. The liquid supply pipe 13 is connected to the transfer liquid supply pipe 13 connected through a joint 12 to the liquid supply pipe 11. Among them, the moving-side liquid supply pipe 13 includes a first liquid supply pipe 13a arranged in a loop as described below, and a flow path terminal of the first liquid supply pipe 13a. From both, a second liquid supply pipe 13 is provided via a joint 14.
b extend so as to merge. The second liquid supply pipe 13b extends from the converging portion from the first liquid supply pipe 13a in a substantially U-shape in a plane, and then the second liquid supply pipe 13b.
The extended end portion b is connected to an ink suction hole (not shown) of the print head 6.

Here, the first liquid supply pipe 13a constituting the moving liquid supply pipe 13 is made of a flexible pipe-like member, and is provided on the outer surface side of the first liquid supply pipe 13a. Are held by a caterpillar-shaped movable support 13c extending in an elongated elliptical shape. The caterpillar-shaped movable support 13c is configured to reciprocate on a fixed track in accordance with the scanning movement of the print head 6 described above. The position of the formed turn-back portion shifts with the scanning movement of the print head 6.

As described above, the second liquid supply pipe 13b extends in a substantially rectangular plane through the joint 14 disposed at the end of the first liquid supply pipe 13a. The extended end portion is connected to the ink suction hole of the print head 6, and a portion of the second liquid supply pipe 13 b immediately after extending from the joint 14 is a portion of the print head 6. It extends substantially parallel to the scanning direction (the horizontal direction in FIG. 6). Therefore, at that site,
Pressure fluctuations are likely to occur in the ink liquid with the scanning movement of the print head 6.

For this reason, in the present embodiment, in the second liquid supply pipe 13b, the joint 14
A continuous meandering pipe 13d as a fluid pressure relief means formed in a wavy shape is disposed at a portion immediately after the extension.
The continuous meandering pipe 13d has a function of absorbing a pressure fluctuation generated in the ink liquid in the second liquid supply pipe 13b, and is provided in a direction inclined with respect to the scanning direction of the print head 6. It is configured to meander and extend in a wavy shape. That is, in the portion of the second liquid supply pipe 13b extending substantially in parallel with the scanning direction of the print head 6, pressure fluctuation is likely to occur due to the inertial force during the scanning movement of the print head 6. However, in the present embodiment, the continuous meandering tube 13d as described above is disposed as a fluid pressure relieving unit in a portion where the pressure fluctuation by the print head 6 is likely to occur.

Then, the ink liquid in the second liquid supply pipe 13b flows in the continuous meandering pipe 13d while meandering in a direction inclined with respect to the scanning direction of the print head 6, whereby the ink liquid is supplied. Of the velocity components of the ink liquid in the scanning direction is reduced, and accordingly, the amount of pressure fluctuation occurring with respect to the velocity component of the ink liquid in the scanning direction is reliably reduced.

On the other hand, in the embodiment according to FIG. 2 in which the same components are denoted by the same reference numerals as those in the above-described embodiment,
A fluid pressure relieving portion 13e having a small-diameter flow path is provided at a substantially central portion in the extending direction of the continuous meandering tube 13d. The fluid pressure relieving portion 13e is provided with a small-diameter flow path 13f as shown in FIG. 3, for example, and a liquid storage chamber 1 consisting of an enlarged passage is provided before and after the small-diameter flow path 13f.
3g and 13g are provided, and the small-diameter flow path 13f is provided.
Are formed such that the two liquid storage chambers 13g communicate with each other.

According to the second embodiment, in addition to the pressure relaxation effect of the continuous meandering pipe 13d in the first embodiment, the ink liquid in the second liquid supply pipe 13b is moved by the fluid pressure. By flowing through the liquid storage chamber 13g and the small-diameter flow path 13f of the relaxation section 13e, the liquid is sent to the print head 6 side at a substantially constant pressure.

At this time, the fluid pressure relieving portion 13e in the above-described embodiment can be replaced with one having a maze-shaped small-diameter flow path 13h as shown in FIG.
According to such an embodiment, the same operation and effect as those of the above-described embodiment can be obtained.

Further, although not shown, the fluid pressure reducing means according to the present invention can be constituted by an orthogonal tube extending in a direction substantially orthogonal to the scanning direction of the print head 6, and such a structure can be employed. In the case where the fluid pressure reducing means composed of a simple orthogonal pipe is employed in the second liquid supply pipe, the ink liquid flowing in the orthogonal pipe of the second liquid supply pipe has almost no velocity component in the scanning direction. In addition, almost no pressure fluctuation occurs with respect to the velocity component of the ink liquid in the scanning direction, so that the ink liquid is stably sent to the print head.

Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above embodiments, and it is needless to say that various changes can be made without departing from the gist of the present invention. Nor.

For example, the present invention can be similarly applied to an ink jet device used in various devices such as a plotter other than the printer as in the above-described embodiment.

[0031]

As described above, the ink supply device of the ink jet recording apparatus according to the first aspect of the present invention is arranged such that the ink flows in the second liquid supply tube at a position midway along the second liquid supply tube which is susceptible to pressure fluctuation. By arranging the fluid pressure relaxation means for absorbing the pressure fluctuation of the ink liquid, the ink liquid in the second liquid supply pipe is sent to the print head side while keeping the ink liquid at a substantially constant pressure. With a simple configuration, the ink liquid can be more stably supplied to the print head, and the reliability of the ink supply device can be improved.

In the ink supply apparatus for an ink jet recording apparatus according to a second aspect of the present invention, a fluid pressure relief unit is provided at a portion of the second liquid supply pipe extending substantially in parallel with the scanning direction of the print head. By arranging the second liquid supply pipe, the ink liquid in the portion where the pressure fluctuation is easily directly affected is sent to the print head side while maintaining the pressure at a substantially constant pressure. The reliability of the device can be further increased.

Further, in the ink supply apparatus for an ink jet recording apparatus according to the third, fourth or fifth aspect, the fluid pressure relief device may include a continuous meandering pipe, a small-diameter flow path, or an orthogonal pipe at an intermediate position of the second liquid supply pipe. By arranging the means, the ink liquid in the second liquid supply pipe is configured to be sent to the print head side while maintaining a substantially constant pressure by a simple configuration. The reliability of the ink supply device can be reliably increased.

[0034]

[Brief description of the drawings]

FIG. 1 is a partially enlarged plan explanatory view of a print head portion illustrating a structure of an ink supply device according to an embodiment of the present invention.

FIG. 2 is a partially enlarged plan view of a print head showing the structure of an ink supply device according to another embodiment of the present invention.

FIG. 3 is an explanatory longitudinal sectional view showing an example of a fluid pressure reducing means according to the present invention.

FIG. 4 is an explanatory longitudinal sectional view showing another example of the fluid pressure relaxation unit according to the present invention.

FIG. 5 is an external perspective view illustrating an example of an inkjet recording apparatus to which the present invention is applied.

FIG. 6 is an explanatory plan view showing an ink liquid supply system in an ink jet recording apparatus to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink jet printer 2 Recording paper 5 Carriage 6 Printing head 7 Ink tank 11 Fixed side liquid supply pipe 12 Joint 13 Moving side liquid supply pipe 13a First liquid supply pipe 13b Second liquid supply pipe 13c Caterpillar movable support 13d Continuous meandering pipe (fluid pressure relieving means) 13e Fluid pressure relieving part 13f Small diameter flow path 13g Liquid storage chamber 13h Maze-shaped small diameter flow path 14 Joint

Claims (5)

[Claims] 1. A print head for discharging ink, a carriage that scans and moves in a direction substantially perpendicular to a paper transport direction while holding the print head, and transfers ink liquid stored in an ink supply source to the print head. Liquid supply pipe
In the ink supply device of an ink jet recording apparatus comprising: a first liquid supply tube formed in a loop so as to allow the ink liquid sent from the ink supply source to flow in an annular shape; A second liquid supply pipe connected to both ends of the flow path of the first liquid supply pipe so as to join the ink liquid in the first liquid supply pipe to the print head; In the middle position of the flow path of the second liquid supply pipe, the second
An ink supply device for an ink jet recording apparatus, further comprising: a fluid pressure reducing unit configured to absorb a pressure change of an ink liquid flowing in the liquid supply pipe. 2. The apparatus according to claim 1, wherein the fluid pressure reducing means is disposed in a portion of the second liquid supply pipe extending substantially parallel to a scanning direction of a print head.
An ink supply device for the ink jet recording apparatus according to the above. 3. The fluid pressure relieving means comprises a continuous meandering tube extending meandering in a direction inclined with respect to the scanning direction of the print head.
An ink supply device for the ink jet recording apparatus according to the above. 4. The ink supply according to claim 1, wherein said fluid pressure reducing means comprises a small-diameter flow pipe having an inner diameter smaller than an inner diameter of said second liquid supply pipe. apparatus. 5. The ink according to claim 1, wherein the fluid pressure reducing unit is formed of an orthogonal tube extending in a direction substantially orthogonal to a scanning direction of the print head. Feeding device.