Ink jet recorder

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Field of Technology to which the Invention belongs]

The present invention relates to a recording device capable of supplying ink to a recording head at an appropriate pressure regardless of the height difference between the ink storage means and the inkjet recording head that ejects ink droplets.

【0002】

[Conventional technology]

An inkjet recording device that prints on a large-sized recording paper such as a poster is configured to supply ink from an ink cartridge of each color provided in the main body of the device to a recording head of each color of the carriage via an ink supply tube. ing. These recording heads are arranged so as to be located on the same horizon. Therefore, there is a problem that the size in the width direction becomes large because a space for accommodating the recording head in the width direction of the recording paper is required so that the recording heads arranged on the side can also print the edge of the recording paper. ..

【0003】

[Problems to be Solved by the Invention]

In order to solve such a problem, it is conceivable to arrange the recording heads in the direction perpendicular to the moving direction of the carriage, but since the recording heads are arranged in the vertical direction, the recording heads are arranged between the ink cartridges arranged in the horizontal direction. There is a problem that a water head difference occurs, the ink supply pressure to each recording head varies, and the print quality deteriorates. The present invention has been made in view of such a problem, and an object of the present invention is to supply ink at an appropriate pressure to a recording head that receives ink supplied from a common ink cartridge via a flow path. It is an object of the present invention to provide an inkjet recording apparatus capable of printing with high print quality.

【0004】

[Means for solving problems]

In order to achieve such a problem, in the present invention, in an inkjet recording apparatus in which a plurality of inkjet recording heads are arranged in the vertical direction and ink is supplied from a common ink cartridge to each recording head via an ink supply path. A differential pressure valve that compensates for the ink supply pressure to the recording head is connected to the upstream side of the recording head in the flow path connecting each recording head and the ink cartridge.

【0005】

[Action]

Even if there is a height difference between the plurality of recording heads, the ink supply pressure can be compensated by the differential pressure valve, and the ink can be uniformly supplied from the ink cartridge common to each recording head.

【0006】

BEST MODE FOR CARRYING OUT THE INVENTION

Therefore, the details of the present invention will be described below based on the illustrated examples. FIG. 1 shows an embodiment of the inkjet recording apparatus of the present invention, wherein a plurality of recording heads 1, 2, and 3 in this embodiment are guide members 11, 12, 21, 22, and 31, respectively. , 32 is provided on carriages 13, 23, 33 movably supported and arranged in the vertical direction.

【0007】

The recording heads 1, 2, and 3 are connected to the outlets of the differential pressure valves 14, 24, and 34, which will be described later, via the ink supply tubes 15, 25, and 35, and ink is ink from a common ink cartridge 5 housed in the gantry 4. The differential pressure valve 14 connected to the recording head 1 arranged in the upper stage is connected to the ink cartridge 5 via the flow path 16 and is connected to the recording heads 2 and 3 arranged in the lower stage. The pressure valves 24 and 34 receive ink from the outlets of the differential pressure valves 14 and 24 located in the uppermost stage, respectively, via the flow paths 26 and 36. Reference numeral P in the drawing indicates a recording sheet.

【0008】

FIGS. 2 (a) and 2 (b) show an embodiment of the above-mentioned differential pressure valve in a valve closed state and a valve open state, and a spring 42 is located between the ink inlet 40 and the ink outlet 41. It is composed of a valve body 44 which is constantly urged to the side of the ink inlet 40 and has a through hole 43 in the center, and a valve seat 45 which seals the through hole 43 of the valve body 44.

【0009】

In the differential pressure valves 14, 24, and 34 configured in this way, the respective springs 42 are adjusted according to the head pressure due to the height difference ΔH1, ΔH2, and ΔH3 between the ink cartridge 5, the recording heads 1, 2, and 3. ing. As a result, when the ink is consumed by the recording head, the pressure at the ink outlet 41 decreases, so that the valve body 44 opposes the urging force of the spring 42 and the valve seat 45 as shown in FIG. 2 (b). Open the valve away from.

【0010】

When the pressure of the ink outlet 41 rises to match the differential pressure set by the spring 42 in this way, the valve body 44 loses the urging force of the spring 42 and is elastically contacted with the valve seat 45 to close the valve. ..

【0011】

In this embodiment, the ink of the ink cartridge 5 flows into the recording head 1 in a state where the pressure is adjusted by the differential pressure valve 14, and the hydraulic head difference ΔH1 is obtained by the differential pressure valve 14 and the hydraulic head by the differential pressure valve 24. The ink compensated for the difference ΔH2 flows into the recording head 3 with the head difference ΔH1 compensated by the differential pressure valve 14, the head difference ΔH2 by the differential pressure valve 24, and the ink compensated for the head difference ΔH3 by the differential pressure valve 34. Therefore, ink with a pressure suitable for printing flows in regardless of the difference in head difference between the common ink cartridge 5 and the plurality of recording heads 1, 2, and 3.

【0012】

Since the differential pressure valves 14, 24, and 34 for adjusting the ink pressures on the recording heads 1, 2, and 3 are connected in series to the ink cartridge 5, each differential pressure valves 14 to 34 are in charge. The pressure becomes almost even, and the same specifications can be used, and the cost can be reduced.

【0013】

Further, since a large pressing force is not required for the spring 42 for setting the differential pressure of the differential pressure valve 34 connected to the recording head 3 located below, the valve body 44 sticks to the valve seat 45 and becomes inoperable. Inconvenience can be prevented.

【0014】

In the above embodiment, ink is also supplied to the recording head 1 located in the upper stage via the differential pressure valve 14, but the ink cartridge 5 and the recording head 1 are installed at substantially the same height. Then, when a negative pressure can be applied to the meniscus of the nozzle of the recording head 1, the differential pressure valve 14 can be eliminated.

【0015】

Further, in the above-described embodiment, the ink is supplied to the plurality of recording heads 1 and 2 or the recording heads 1 to 3 via one differential pressure valve 14 and 25, but the ink is supplied to each recording head. When the amount of ink consumed is large and one pressure differential valve cannot cope with the amount of ink consumed, it may be connected via a plurality of pressure differential valves as shown in FIG.

【0016】

That is, the flow path 16 connected to the ink cartridge 5 is branched into the flow path connected to the recording head 1 and the flow path connected to the other recording heads 2 and 3 in the lower stage at the branch point 16a, and the recording head 1 is provided with a branch point 16a. Ink is supplied to the lower recording heads 2 and 3 via the differential pressure valve 14 and via the differential pressure valve 24-1. Further, the flow path 26 connecting the differential pressure valve 24-1 and the recording head 2 is branched at the branch point 26a as described above, and ink is supplied to the recording head 2 via the differential pressure valve 24-2 to record. Ink is supplied to the recording head 3 below the pad 2 via the differential pressure valve 34-1, the flow path 36, and the differential pressure valve 34-2.

【0017】

According to this embodiment, not only can ink be supplied to each of the recording heads 1, 2 and 3 while maintaining an appropriate negative pressure via dedicated pressure differential valves 14, 24-2 and 34-2. Ink can be supplied according to the height difference between the ink cartridge and each recording head and the amount of ink consumed by the recording head by using a differential pressure valve having a small load capacity and common specifications.

【0018】

If one differential pressure valve cannot cover the amount of ink on the downstream side, a plurality of differential pressure valves 24-1 and differential pressure valves 24-3 are used as shown in FIG. In addition, the differential pressure valve 34-1 and the differential pressure valve 34-3 may be connected in parallel for use.

【0019】

In this way, differential pressure valves with the same specifications are connected in series according to the height difference between the ink cartridge and each recording head, while multiple differential pressure valves with the same specifications are connected in parallel according to the amount of ink consumed. As a result, the cost can be reduced as compared with the case where the differential pressure valve is individually manufactured according to the amount of passing ink.

【0020】

In the above-described embodiment, the case where ink is supplied to a plurality of recording heads has been described, but even in a recording device provided with a single inkjet recording head, the height of the ink storage means and the inkjet recording head is high or low. It can be applied when the difference is large. That is, as shown in FIG. 5, a plurality of differential pressure valves 2 as shown in FIG. 2 are connected in series in the middle of the ink supply tube 16 connecting the inkjet recording head 1 and the ink cartridge 5 according to the height difference. It is possible to deal with this by connecting to multiple ink cartridges or connecting multiple ink cartridges in parallel as shown in Fig. 6.

【0021】

According to the former embodiment, even if the differential pressure valves 2 have the same specifications, the hydraulic head pressure due to the height difference between the ink cartridge 5 and the recording head 1 is shared by the differential pressure valves 2 and 2 respectively. Therefore, it is possible to cope with the head difference without changing the specifications of the differential pressure valve 2.

【0022】

According to the latter embodiment, even if the ink supply capacity of the differential pressure valve 2 is lower than the ink consumption of the recording head 1, the differential pressure valves of the same specifications are used in the number corresponding to the required supply capacity. can do.

【0023】

[Effect of the invention]

As described above, in the present invention, the differential pressure valve for compensating the ink supply pressure to the recording head is connected to the upstream side of the recording head in the flow path connecting each recording head and the ink cartridge. The differential pressure valve compensates for the pressure caused by the height difference of multiple recording heads arranged one above the other, and ink can be supplied from a common ink cartridge to each recording head at a uniform pressure, enabling printing with high print quality. Become.

[Simple explanation of drawings]

[Figure 1]

It is a figure which shows one Example of the inkjet recording apparatus of this invention about the ink supply system.

[Figure 2]

FIGS. (A) and (B) are cross-sectional views showing an embodiment of a differential pressure valve used in the same recording device, respectively, in a valve closed state and a valve open state.

[Fig. 3]

It is a figure which shows another Example of the inkjet recording apparatus of this invention.

[Fig. 4]

It is a figure which shows another Example of the inkjet recording apparatus of this invention.

[Fig. 5]

It shows another embodiment of the inkjet recording apparatus of this invention.

[Fig. 6]

It shows another embodiment of the inkjet recording apparatus of this invention.

[Explanation of symbols]

1, 2, 3 recording head 5 ink cartridge 14, 24, 34 differential pressure valve 15, 25, 35 ink supply tube 40 Ink inlet 41 Ink outlet 42 spring 43 Through hole 44 valve body