JPH048232B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inkjet device equipped with a suction device for sucking nozzle heads of an inkjet device such as an inkjet printer, and particularly to a suction device that suctions ink or air from a multi-nozzle head for multi-color printing. The present invention relates to an inkjet device comprising:

When performing multicolor printing in an inkjet device such as an inkjet printer, a multi-nozzle head is generally used. FIG. 1 is a perspective view showing the main parts of an inkjet device having a dedicated ink sub-tank for each independent inkjet nozzle. The head 1 has inkjet nozzles in separate sub-tanks 1-1, 1-2, 1-3, and 1-4, and prints by ejecting ink of a unique color from the ejection opening at the tip of each nozzle. conduct. In the figure, reference numeral 2 denotes a cap for sealing the tip of the head, that is, the ejection port of each nozzle, and prevents the tip of the nozzle from drying out and ink from leaking. Each of the caps 2 is connected to a tube 3 whose one end is connected to a suction pump 4 serving as ink suction means.
The negative pressure generated by the pump 4 sucks ink from each nozzle to eliminate or prevent ejection failures including ejection failures in each nozzle.

However, such an inkjet device has the following problems. In other words, if the ink is left capped after ink suction, since the tubes 3 are connected at the tips, each nozzle will be in a state of communication through the tubes 3 at this part, and the ink will spread and mix colors, and the inside of the nozzles will be mixed. It has been found that color mixing may occur not only in the sub-tank but also in the sub-tank.

The present invention has been made in view of these problems, and it is an object of the present invention to provide an inkjet device equipped with suction means for a multi-nozzle head that does not cause ink mixing even when left unused.

The inkjet device of the present invention achieves this object, and includes a cap for covering each of a plurality of ejection ports that eject different inks, and a cap that is provided in common to the plurality of ejection ports, and that the cap is provided in common to the plurality of ejection ports. a suction means having a common suction space that suctions each ink from the plurality of ejection ports through the cap when covering the plurality of ejection ports; a plurality of ink suction passages for causing ink to flow into the suction space for each type of ink; and communication between the suction space and the plurality of ink suction passages when suction is not being performed by the suction means. The suction means is characterized in that the suction means has a shutoff means for shutting off.

According to the present invention, it is possible to solve the problem of the plurality of inks entering one of the transmission paths in a mixed state, so that each nozzle can stably perform recording with the original ink. can.

FIG. 2 shows an inkjet device equipped with a suction device for a multi-nozzle head according to an embodiment of the present invention, in which flexible connection tubes 13A to 13D for ink suction are connected to a suction pump 12, which is the main body of the suction device.
A cap 14 is connected via the cap. The multi-nozzle head 15, which is a recording head, has an integrated structure in which four sealed sub-tanks 15-1 to 15-4 are arranged side by side, and each sub-tank is equipped with an inkjet nozzle for ejecting ink. has been done. An independent main tank (only 16 is shown) is connected to each sub-tank, and each sub-tank receives ink supply from each main tank. Each sub tank 15-1 to 15-4
Flexible air release tubes 17A to 17D are connected to the tank to remove air from the tank, and each tube 17A to 17D is connected to the suction pump 12. When not printing, the above-mentioned cap 14 is attached to the front surface of the multi-nozzle head 15 while keeping it confidential to prevent each nozzle of the head from drying out. The suction pump 12 roughly consists of a cylinder part 18 and a piston part 19 that fits into the cylinder part 18, and the piston 19 moves to generate negative pressure and suck ink from each nozzle via the connecting tubes 13A to 13D. , and each air vent tube 17
Excess air is removed from each sub-tank via A to 17D. Although not shown, a pressing knob is formed above the piston 19. Further, a cylinder seal 20 made of an elastic material such as rubber is fitted and fixed to the piston portion. As shown in FIG. 3, the seal 20 has two protrusions 20A and 20B.
Each convex portion 20A, 2 has a ring shape with
0B is in close contact with the cylinder inner wall. Here, the convex part 2
The thickness of 0B is larger than the diameter of the ink and air intake ports 21 formed in a line in the circumferential direction on the wall surface of the cylinder 18 so that each of the connecting tubes 13A to 13D and air vent tubes 17A to 17D are blocked. . 22 is a coil spring which functions to always urge the piston 19 upward. 9 is an O-ring. 7,
Reference numeral 8 designates a discharge hole and a check valve. When the piston 19 moves upward from the lowest position due to the restoring force of the spring 22, the check valve 8 opens and the air is discharged through the connecting tubes 13A to 13D or the air vent tubes 17A to 17D. The ink sucked into the cylinder 18 is discharged downward from the discharge hole 7.

FIG. 2 shows a state in which the tips of each nozzle of the head 15 are sealed by the cap 14 and ink and air can be sucked by pushing down the piston 19, and a state in which the piston 19 is returned by the spring 22 and suction is completed. It shows both. When the piston 19 is pushed down and the seal 20 is in the position indicated by the two-dot chain line, the inner surface of the cylinder, the O-ring 9,
The air which is the suction space formed by the piston 19
23 expands, the valve 8 closes and negative pressure is generated, and the sub tanks 15-1 to 15-4 are injected into the connecting tubes 13A to 13D and the air vent tubes 17A to 17D.
Different colors of ink flow into each. When the piston 19 is returned to its original position while the space 23 and the connecting tubes 13A to 13D are under negative pressure before the expanded space 23 is filled with ink, the upper convex portion 20A of the seal 20 passes through the suction port 21. At this point, the insides of the connecting tubes 13A to 13D can be maintained in a negative pressure state. Here, the seal 20 shown in FIG.
If the relief 20C is filled with grease, even when the piston 19 is suddenly raised to the position shown by the solid line in FIG. 2 by the force of the spring 22, the connection tubes 13A to 1
Negative pressure within 3D can be maintained. Incidentally, the ink in the gap 23 is discharged from the discharge hole 7 when the piston returns. At this point, the outer circumferential surface of the protruding portion 20B at the bottom of the seal 20 closes the suction port 21. Since this suction port is closed in a negative pressure state, ink continues to be suctioned from the sub-tank and nozzles, which are at approximately atmospheric pressure, to normalize the meniscus of each nozzle and enable ink to be ejected. Also, even if left in the state shown in Fig. 2, all connecting tubes 13A to 13
D. The air vent tubes 17A to 17D are separated by the lower protruding portion 20B of the seal 20 at the suction port 21 of the cylinder, thereby preventing color mixing of inks.

Further, each suction port 21 may be provided anywhere in the circumferential direction of the cylinder 18, so for example, the connecting tubes 13A to 13D and the air vent tubes 17A to
17D can be approached as shown in Figure 4, connecting tube,
The air vent tube can be arranged compactly. Further, it is sufficient that the suction port 21 has a direct thickness of about 0.5 mm and the thickness of the lower convex portion 20B of the seal is 1 mm, so that the sliding resistance of the piston can be sufficiently reduced.

As explained above, according to the present invention, it is possible to solve the problem of the plurality of inks entering one of the transmission paths in a mixed state, so that each nozzle can stabilize recording with the original ink, In particular, according to a preferred embodiment of the present invention, since the suction port of the cylinder portion is closed by the seal portion of the piston, it is possible to prevent color mixing of ink when left unused, and furthermore, the suction port can be arranged arbitrarily. This makes tube placement easier and reduces piston sliding resistance.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conventional example, FIG. 2 is an explanatory diagram of an embodiment of the present invention, FIG. 3 is a sectional view of a seal portion of a piston, and FIG. 4 is a top view of a pump portion. 12... Suction pump, 14... Cap, 15
...Multi nozzle head, 18...Cylinder part,
19... Piston part, 20... Seal, 21...
Suction port.

Claims (1)

[Claims] 1. A cap for covering each of a plurality of ejection ports that eject different inks, and a cap provided in common for the plurality of ejection ports, and when the cap covers the plurality of ejection ports. a suction means having a common suction space for suctioning each ink from the plurality of ejection ports through the cap; a plurality of ink suction paths for flowing ink into a space; the suction means includes a blocking means for cutting off communication between the suction space and the plurality of ink suction paths when suction is not being performed by the suction means; An inkjet device comprising: 2. The ink jet device according to claim 1, wherein the suction means is a suction pump that generates negative pressure in the suction space when the cap covers the plurality of ejection ports. 3. The ink jet device according to claim 1, wherein the suction space is formed using a cylinder and a piston fitted into the cylinder, and the piston is provided with a convex portion as the blocking means. . 4. The ink ejected from the plurality of ejection ports is
An inkjet device according to claim 1, each having a different color.