JPH0242672B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a discharged ink recovery device in a print head of an inkjet printer.

(2) Background of the technology In the print head of an inkjet printer, the ink inside the head is cleaned to remove air bubbles, foreign matter, ink that has changed in quality, etc. that have entered or remained in the ink ejection system such as nozzles and piezoelectric elements. It is sometimes necessary to perform an operation called purge, in which ink is discharged from the nozzle by applying pressure.

(3) Prior art and problems Figure 6 is a diagram showing a conventional discharged ink recovery device.
FIG. 7 is a diagram showing a state in which discharged ink is recovered in the recovery device of FIG. 6.

If the ink discharged by purging is allowed to flow out as it is, the ink on the front surface 16a of the head will not be completely removed, so as shown in FIG. A discharged ink recovery device 1 is provided, and a pump 3 is installed.
The ink 6 in the ink tank 5 is pressurized by
The ink 6 is discharged from the tip of each nozzle 9 through the common ink chamber 7, and the ink 6 is further sucked by the pump 3 through the ink discharge path 4 and the ink passage 2, as shown in FIG. A recovery method has been used, but this method requires a pump 3 for ink suction, has a complicated structure, and is prone to breakdowns.

(4) Object of the Invention In order to eliminate the above-mentioned drawbacks, it is an object of the present invention to provide a discharged ink recovery device that does not require an ink suction pump.

(5) Structure of the Invention In other words, the present invention provides an ink recovery passageway in which an inlet and an outlet are set at the same height, and an ink recovery chamber that collects ink flowing from the inlet into the outlet. Further, the ink recovery passage between the suction port and the discharge port is filled with liquid.

(6) Embodiments of the Invention The present invention will be specifically described below based on embodiments shown in the drawings.

FIG. 1 is a plan view showing an example of an ink jet printer to which the present invention is applied, FIG. 2 is a diagram showing an embodiment of the discharged ink recovery device according to the present invention, and FIG.
The figure is a circuit diagram showing an example of an ink recovery amount detection device.
FIG. 4 is a diagram showing a state in which discharged ink is collected by the collection device shown in FIG. 2, and FIG. 5 is a diagram showing another embodiment of the present invention.

As shown in FIG. 1, the inkjet printer 8 has a screw shaft 13 that is rotationally driven by a drive motor 10 via a belt 11, a pulley 12, etc. The shaft 13 has a print head 16. Carrier 15 equipped with
0, they are screwed together so that they can be freely moved and driven in the directions of arrows B and C. A platen 19 on which a print medium 17 is set is provided on the front surface of the print head 16, and as shown in FIG. 2, a common ink chamber 7 is connected to an ink tank (not shown).
is formed. The common ink chamber 7 has a feeder path 2.
A plurality of pressure chambers 21 each having a piezoelectric element provided therein are provided, and each pressure chamber 21 is formed with a nozzle 9 that communicates with the head front surface 16a. An ink recovery passage 23 is formed on the front face 16a of the head, and includes an ink discharge passage 4, an ink passage 2, etc., in which the suction port 23a and the discharge port 23b are set at the same height AH.
3b is filled with ink 6, and furthermore, the discharge port 23b is filled with ink 6.
An ink recovery chamber 26 in which an ink absorbing member 25 is housed is provided. The ink 6 between the suction port 23a and the discharge port 23b is filled so as to come into contact with the ink absorbing member at the discharge port 23b. As shown in FIG. 3, the absorbing member 25 is provided with an ink recovery amount detection device 31 comprising resistors 27, 27 having a resistance value R, a resistor 29 having a resistance value _R0 , and a comparator 30.

Since the present invention has the above-described configuration, during normal printing, the drive motor 10 moves the print head 16 in the directions of arrows B and C to the carrier 15.
and selectively drives the piezoelectric element in the pressure chamber 21 to direct the ink 6 from the nozzle 9 to the print medium 17.
Printing is performed by spraying it upward. On the other hand, during purging, the ink 6 in the common ink chamber 7 is pressurized to cause the ink 6 to flow out from the nozzle 9 in a mechanical shape as shown in FIG. 4a. The spilled ink 6 moves downward under its own weight, and eventually flows from the suction port 23a of the collection passage 23 to the passage 2, as shown in FIG.
Connects with ink 6 that satisfies 3. As a result, the liquid level at the ink suction port 23a becomes substantially higher, so the liquid level at the outlet 23b also becomes higher, and the ink discharged from the nozzle is always absorbed by the ink absorbing member 25 that is in contact with the ink on the discharge side. be done. Nozzle 9
Since the ink 6 discharged from the head flows slowly in the direction of the passage 23, the ink 6 in the passage 23 does not overflow from the suction port 23a, and the ink 9 remains on the front surface 16a of the water-repellent head. There's nothing to do. In this way, the ink 6 flows into the passage 23 every time it is purged, but when the amount of ink absorbed by the absorbing member 25 increases and reaches its limit, the resistance value RA between the electrodes 32 and 32 decreases as shown in FIG. It decreases from the initial value in the non-absorbed state, and RA<
Becomes an RO. Then, the potential at point E becomes lower than the potential at point D, and the comparator 30 operates to output an alarm signal WS, notifying the operator that it is time to replace the member 25.

In addition, in the above-mentioned embodiment, the ink recovery device 1 is
Although the case has been described in which the recovery device 1 is mounted on the carrier 15 together with the print head 16, it is not necessarily necessary to install the recovery device 1 on the carrier 15. Of course, it is also possible to set it up like this,
In the case of this embodiment, since nothing is provided on the head 16 side, the head front surface 16a and the print medium 17
It is possible to set a short distance between the printer and the printer 1, and it is possible to prevent the print quality from deteriorating due to the installation of the device 1.

(7) Effects of the Invention As explained above, according to the present invention, ink flowing from the suction port 23a into the ink collection passage 23 and the discharge port 23b in which the suction port 23a and the discharge port 23b are set at the same height AH. In addition to providing an ink collection chamber 26 for collecting ink 6, an ink collection chamber 26 is provided to collect the ink
Since the space between 3a and the discharge port 23b is filled with liquid such as ink, the ink 6 discharged during purging can be absorbed into the ink absorbing member 25 etc. without using the pump 3, resulting in a simple structure and less trouble. It becomes possible to provide the discharged ink recovery device 1.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an example of an inkjet printer to which the present invention is applied, FIG. 2 is a diagram showing an embodiment of the discharged ink recovery device according to the present invention, and FIG. 3 is a plan view of an ink recovery amount detection device. A circuit diagram showing an example, FIG. 4 is a diagram showing the state of collection of discharged ink by the collection device of FIG. 2, FIG. 5 is a diagram showing another embodiment of the present invention, and FIG. FIG. 7 is a diagram illustrating the recovery state of discharged ink in the recovery device of FIG. 6. 1...Discharged ink collection device, 6...Ink, 8
...Inkjet printer, 9...Nozzle, 1
6... Print head, 23... Ink recovery passage, 23a... Suction port, 23b... Outlet port, 26
...Ink collection room.

Claims (1)

[Scope of Claims] 1. A printing device that performs a printing operation by ejecting ink from nozzles of a print head, and includes an ink suction port located at the lower front of the print head;
an ink recovery passageway connected to an ink recovery chamber and a discharge port connected to the ink recovery chamber; an ink absorbing member connected to the discharge port is provided in the ink recovery chamber; and the ink flowing out from the nozzle is passed through the ink recovery passageway. In an inkjet printer that collects ink into an ink recovery chamber, the ink inlet and ink outlet of the ink recovery passage are set at the same height, and the liquid level of the ink inlet is located near the bottom of the nozzle. and a discharged ink recovery device, characterized in that the ink recovery passage is filled with liquid so that the liquid level of the ink discharge port contacts the ink absorbing member.