JP3770304B2 - Inkjet recording device - Google Patents

Description

[0001]
[Field of the Invention]
The present invention relates to an ink jet recording apparatus that performs printing while supplying ink from a main tank to a recording head with an ink supply tube.
[0002]
[Prior art]
An ink jet recording apparatus that prints on a large recording paper such as a poster is configured to supply ink from each color ink cartridge provided in the apparatus main body to each color recording head of the carriage via an ink supply tube. ing.
These recording heads are arranged so as to be located on the same horizontal line. For this reason, a space that can accommodate the recording head in the width direction of the recording paper is required so that the recording head arranged on the side can also print the end of the recording paper, and there is a problem that the size in the width direction increases. .
[0003]
[Problems to be solved by the invention]
In order to solve such a problem, it is conceivable to arrange the recording head in a direction perpendicular to the moving direction of the carriage. However, since the recording heads are arranged in the vertical direction, the recording head is arranged between the ink cartridges arranged in the horizontal direction. There is a problem that the 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 with a uniform pressure to a recording head arranged in the vertical direction so that printing with high print quality is possible. Is to provide an ink jet recording apparatus.
[0004]
[Means for Solving the Problems]
In the present invention in order to achieve such a problem, a plurality of recording heads are arranged with a height difference in the vertical direction, the ink through the respective ink supply tubes to each of the recording heads of the same ink cartridge in the ink jet recording apparatus that supplies are respectively valve mechanism is connected between the outlet side of the ink of each of the recording head ink inlet port side and each of the ink supply tube of each of the valve mechanism, the front and back And a biasing means for biasing the valve body in the valve closing direction. The biasing force of each of the valve mechanisms is between the inlet side and the outlet side. When the differential pressure is the differential pressure between the head pressure due to the height difference between the respective recording heads and the ink cartridge and the pressure difference between the inlet and the inlet, the valve body maintains the valve closed state. The valve element opens at a differential pressure when a negative pressure greater than a predetermined value generated by ink consumption of the recording head acts on the inlet side, and the negative pressure becomes smaller than the predetermined value. The valve body is set to be closed when the plurality of recording heads are closed, and a difference corresponding to a water head difference due to a height difference between the plurality of recording heads is provided between the urging forces of the respective valve mechanisms. Compensating for the height difference between the recording heads, ink is supplied to each of the recording heads with a uniform pressure .
[0005]
[Action]
Ink is supplied to each recording head with a uniform pressure by compensating for the water head difference of each recording head by a valve mechanism.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Therefore, details of the present invention will be described below based on the illustrated embodiment.
FIG. 1 shows an embodiment of an ink jet recording apparatus according to the present invention. A plurality of carriages 3 which are supported by a guide member 1 and 2 so that their upper and lower ends are movably supported are vertically arranged. In FIG. 3, three recording heads 4, 5, and 6 are arranged. Buffer tanks 7, 8, and 9 to be described later are connected to the recording heads 3 to 5, respectively, and ink consumed for printing is supplied from the buffer tanks 7 to 9, respectively.
[0007]
The buffer tanks 7 to 9 are connected to a common ink cartridge 13 via ink supply tubes 10, 11, and 12, respectively. A platen 14 for supporting recording paper is disposed on the nozzle surfaces of the recording heads 4 to 6, and paper feed rollers 15 and 16 are provided above and below. Reference numeral 17 in the figure denotes a cartridge rack.
[0008]
FIG. 2 shows an example of the above-described buffer tank by taking an example of one buffer tank 7. The connection port of the ink supply tube 10 is provided above the case 21 constituting the ink storage chamber 20. 22 and an outlet 23 for supplying ink to the recording head 4 is formed in the lower part.
[0009]
Between the outlet 23 and the ink storage chamber 20, a valve mechanism 24 capable of adjusting the differential pressure when the valve is opened is provided.
As shown in FIGS. 3 (a) and 3 (b), the valve mechanism 24 is constantly urged toward the ink storage chamber 20 side by a spring 25, and has a through hole 26 in the center, and a valve body. And a valve seat 28 that seals the through hole 26 of the valve 27. One surface of the valve element 27 is connected to the ink storage chamber 20 through the through hole 29, and the other surface is connected to the outflow port through the through hole 30. It is comprised so that it may communicate with 23.
[0010]
Incidentally, as shown in FIG. 1, the recording heads 5 and 6 are connected to the recording heads 5 and 6 because there are height differences ΔH1 and ΔH2 in the vertical direction with respect to the recording head 4 at the uppermost position. The springs 25 of the buffer tanks 8 and 9 are set so that their elastic pressure is increased by the hydraulic head pressure corresponding to the height differences ΔH1 and ΔH2.
[0011]
In this embodiment, when the ink cartridge 13 is mounted, the ink in the ink cartridge 13 is passed through the ink supply tubes 10, 11, and 12 by a siphon phenomenon through an air communication hole (not shown) formed in the ink cartridge 13. Flows into 7, 8, and 9. Among the buffer tanks, the ink in the ink storage chambers 20 of the buffer tank 8 and the buffer tank 9 is higher in pressure than the ink in the ink storage chamber 20 of the buffer tank 7 by the height differences ΔH1 and ΔH2, respectively.
[0012]
In this state, when ink is consumed by the recording heads 5, 6, 7 due to printing or the like, the pressure at the outlet 23 of the buffer tanks 7, 8, 9 decreases, so that the valve element 27 resists the urging force of the spring 25. Then, as shown in FIG. 3 (b), the ink leaves the valve seat 28 and the ink in the ink storage chamber 20 flows into the recording heads 5, 6, 7 from the through holes 26.
[0013]
When the ink flows into the recording heads 5, 6, 7 until the differential pressure set by the springs 25 of the buffer tanks matches in this way, the valve bodies 27 of the buffer tanks 7, 8, 9 are Losing the urging force, it is elastically contacted with the valve seat 28 and the flow path is closed.
[0014]
As a result, the recording heads 6 and 7 can receive ink supply at the same pressure as the recording head 5 regardless of the height differences ΔH1 and ΔH2 between the recording heads 5.
[0015]
Further, during the non-printing period, the valve bodies 27 of the buffer tanks 7, 8, 9 are elastically contacted with the valve seat 28 by the urging force of the spring 25 to close the flow path. Even if the porous material is not accommodated, leakage of ink from the recording heads 5, 6, and 7 is prevented.
[0016]
In the above-described embodiment, the valve mechanism for compensating the head differential is incorporated in the buffer tank. However, it is obvious that the same operation can be achieved even if only the valve mechanism is provided.
[0017]
In the above-described embodiment, ink is distributed from the common ink cartridge 13 to the plurality of buffer tanks 7, 8, and 9. As shown in FIG. If ink is supplied by the independent ink cartridges 30, 31, and 32, color printing can be handled.
[0018]
【The invention's effect】
As described above, according to the present invention, the water head difference of each recording head can be compensated by the valve mechanism, and ink can be supplied to each recording head with a uniform pressure, regardless of the height difference of the recording heads. Printing with high print quality becomes possible.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an ink supply system according to an embodiment of an ink jet recording apparatus of the present invention.
FIG. 2 is a cross-sectional view showing an embodiment of a buffer tank used in the recording apparatus.
FIGS. 3A and 3B are enlarged views showing the valve mechanism of the same buffer tank. FIG.
FIG. 4 is a diagram showing an ink supply system according to another embodiment of the ink jet recording apparatus of the present invention.
[Explanation of symbols]
1, 2 Guide member 3 Carriage 4, 5, 6 Recording head 7, 8, 9 Buffer tank 10, 11, 12 Ink supply tube 13, 14, 15 Ink cartridge 20 Ink storage chamber 21 Case 22 Connection port 23 Outflow port 24 Valve Mechanism 25 Spring 26 Through-hole 27 Valve element 28 Valve seat 29, 30 Through-hole

Claims (2)

A plurality of recording heads are arranged with a height difference in the vertical direction, the ink jet recording device for supplying ink through the respective ink supply tubes to each of the recording head from the same ink cartridge,
A valve mechanism is connected between the ink inlet side of each of the recording heads and the ink outlet side of each of the ink supply tubes;
Each of the valve mechanisms includes a valve body that receives a differential pressure on the front and back sides, and an urging unit that urges the valve body in a valve closing direction.
The biasing force of each of the valve mechanisms is such that the differential pressure between the inlet side and the outlet side is the difference between the head pressure due to the height difference between the recording head and the ink cartridge and the inlet side. While the valve body remains closed at a differential pressure, the valve body opens at a differential pressure when a negative pressure greater than a specified value generated by ink consumption of the recording head is applied to the inlet. The valve body is set to close when the negative pressure becomes smaller than the specified value, and the height between the plurality of recording heads is increased between the urging forces of the respective valve mechanisms. An ink jet recording apparatus configured to provide a difference corresponding to a water head difference due to the difference to compensate for a height difference between the plurality of recording heads and to supply ink to each of the recording heads with a uniform pressure . In the ink jet recording device for supplying ink through an ink supply tube from each of the plurality of Lee ink cartridge disposed at the same height on each of the recording head a plurality of recording heads are arranged with a height difference in the vertical direction ,
A valve mechanism is connected between the ink inlet side of each of the recording heads and the ink outlet side of each of the ink supply tubes;
Each of the valve mechanisms includes a valve body that receives a differential pressure on the front and back sides, and an urging unit that urges the valve body in a valve closing direction.
The biasing force of each of the valve mechanisms is such that the differential pressure between the inlet side and the outlet side is the difference between the head pressure due to the height difference between the recording head and the ink cartridge and the inlet side. While the valve body remains closed at a differential pressure, the valve body opens at a differential pressure when a negative pressure greater than a specified value generated by ink consumption of the recording head is applied to the inlet. The valve body is set to close when the negative pressure becomes smaller than the specified value, and the height between the plurality of recording heads is increased between the urging forces of the respective valve mechanisms. An ink jet recording apparatus configured to provide a difference corresponding to a water head difference due to the difference to compensate for a height difference between the plurality of recording heads and to supply ink to each of the recording heads with a uniform pressure .

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