JP2001138544A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that a printing head part or the periphery thereof is contaminated with ink even if the abnormality of an ink recovery system is detected in an ink jet recording apparatus because the detection of the abnormality has been performed heretofore after ink is ejected and maintenance such as washing, repairing or the replacement of a part becomes indispensable in order to restore the abnormality of the ink recovery system. SOLUTION: In an ink jet recording apparatus generating ink particles by applying vibration to ejected ink, a means circulating ink through an ink supply route in a stage before ink is sent to nozzles under pressure and detecting the output of the pressure sensor connected to the ink supply route and preventing the ejection of ink from the nozzles when the output of the pressure sensor becomes predetermined pressure or more is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly, to a technique for detecting an abnormality in an ink recovery system.

[0002]

2. Description of the Related Art Due to the function of a recovery pump of an ink jet recording apparatus, the secondary side communicates with a container for storing ink circulating in the apparatus and is open to the atmosphere. Therefore, if the operation of the device is stopped for a long period of time, the ink will stick and clog due to drying of the ink in the collection pump, and the next time the device is operated, the ink will be discharged from the gutter when the ink is ejected from the nozzles. It cannot be collected and the ink overflows. As a result, the area around the head to be printed is stained with ink, which causes great trouble for customers.

By the way, the recovery pump is stuck or clogged, and the recovery pump is in a state where the primary side and the secondary side are not in communication, and the required performance cannot be output. In order to detect that,
Ink is ejected from the nozzles, a charge is applied to the ejected ink particles, and the determination is made based on the state of an electric signal generated in the gutter portion when the ink particles reach the gutter for collecting ink.

[0004]

However, in order to detect an abnormality in the ink recovery system, conventionally, only countermeasures have been taken after the ink has been ejected. In order to recover from such abnormalities, maintenance such as cleaning, repair, and replacement of parts is indispensable.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the need for cleaning, repair, replacement of parts and the like when recovering from an abnormality without detecting contamination of the print head and its surroundings with ink when detecting an abnormality in the ink recovery system. To provide an ink jet recording apparatus.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to provide a method of manufacturing a printer, comprising: vibrating ink ejected to generate ink particles; and charging and deflecting the ink particles so that the ink particles reach a predetermined location on a recording medium. In an ink jet recording apparatus that performs recording by causing the ink to circulate through an ink supply path and detect an output of a pressure sensor connected to the ink supply path at a stage before the ink is pressure-fed to a nozzle, the pressure sensor This is achieved by providing a means for preventing ink from being ejected from the nozzles when the output of the ink becomes a predetermined pressure or more.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a view showing a circulation path of an ink jet recording apparatus to which a two-port solenoid valve according to an embodiment of the present invention is applied.

To explain the structure, the ink 2 in the ink main container 1 is sucked by the supply pump 4 through the electromagnetic valve 3, and is sent under pressure to the supply pump secondary side path to be filtered. The foreign matter is removed by 5, the pressure is reduced to an appropriate pressure by the pressure reducing valve 6, and the ink is ejected from the nozzle through the electromagnetic valve 8 to become ink particles. The reduced pressure is monitored by a pressure gauge 7. The ink not used for printing is captured by the gutter 11 and the electromagnetic valve 12
And is sucked by the collection pump 13 and collected in the ink main container 1. When stopping the apparatus, the solenoid valve 14 is opened at the end of the stop processing to release the pressure in the supply path. The electromagnetic valve 14 is also opened when the ink is circulated for the purpose of equalizing the ink inside the main body. The solenoid valve 12 installed in the collection path is used to prevent the ink remaining in the collection path from flowing back toward the gutter 11 and overflowing the print head while the apparatus is stopped, or to block the flow in the collection path. A nozzle circulation path 15 is provided for use by the recovery pump 13. Other solenoid valves and pumps control the flow of ink by controlling the cleaning of the passages and parts, or keeping the physical properties of the ink constant, or by a combination of operations.

In FIG. 1, the secondary path of the solenoid valve 14 and the secondary path of the solenoid valve 12
In the embodiment of FIG. 1, before the ink is fed to the nozzles, the ink is circulated through the ink supply path, and the pressure sensor connected to the ink supply path An output is detected, and if the output of the pressure sensor becomes equal to or higher than a predetermined pressure, ink is not ejected from the nozzles.

In the above configuration, when the apparatus is operated, that is, when the ink is ejected, the operation sequence of the circulating system components is basically as shown in FIG. The ink 2 in 1 is sucked by the supply pump 4 to pressurize the path to the electromagnetic valve 8. Next, when the pressure is sufficiently increased, the electromagnetic valve 8 is opened in step 2 and the ink particles 10 are ejected from the nozzle 9. At this point, the collection pump 13 is stuck or clogged, and the state of the collection pump 13 is equal to the state where the primary side and the secondary side of the collection pump 13 are not in communication, and the required performance cannot be output. In order to detect this, conventionally, an electric charge is applied to the ink particles ejected from the nozzle 9 and the determination is made based on the state of the electric signal generated in the gutter portion when the ink particles reach the gutter for collecting the ink. I have to.

On the other hand, in the present embodiment, as an operation sequence as shown in FIG. 4, in step 1, the ink 2 in the ink main container 1 is sucked by the supply pump 4 and sent out to the secondary side, and the electromagnetic valve 14 , An ink circulation operation returning to the ink main container 1 via the recovery pump 13 is performed.

While performing the ink circulation operation, the control unit 17 takes in the output of the pressure gauge 7, that is, the pressure of the ink supply path.

FIG. 5 is an output diagram of the pressure sensor when the operation of the ink recovery system is normal in this embodiment, and FIG. 6 is an output diagram of the pressure sensor when the operation of the ink recovery system is abnormal in this embodiment. , Pressure sensor output 1kgf / cm ²
As the threshold level, and 1 kgf / cm ² or less normal regions, and with 1 kgf / cm ² or more abnormal region. When the recovery pump 13 is operating normally, the pressure value changes depending on the performance balance between the supply pump 4 and the recovery pump 13, but if there is no major pressure loss factor on the secondary side of the pressure gauge 7, the pressure gauge 7 Pressure value is very low (Fig. 5)
Becomes

On the other hand, if the recovery pump 13 has an abnormality such as sticking or clogging, that is, if there is a large pressure loss factor, the pressure value of the pressure gauge 7 increases according to the degree of the sticking or clogging (FIG. 6).

Therefore, if the output of the pressure gauge 7 is 1 kgf / cm ² or more, the control unit 17 does not proceed to the next step 2 but displays an abnormal condition as a message on an operation screen of a CRT or the like as a message. According to this configuration, it is possible to detect an abnormality in the ink recovery system at a stage before the ink 10 is ejected from the nozzle 9, and to contaminate the print head and its surroundings with the ink. In addition, when recovering from an abnormality, maintenance such as cleaning, repair, and parts replacement can be eliminated.

Even if an abnormality is detected in step 1, the state is maintained for a predetermined period of time, and before the predetermined period of time elapses, the clogging which has caused the abnormality due to an increase in the ink pressure is washed away. Or fix the fixation that caused the abnormality due to the resolubility of the fixed ink,
When the output of the pressure gauge 17 drops to 1 kgf / cm ² or less, the abnormality is released, and if the operation sequence proceeds to the next step 2, the return from the mild abnormal operation to the normal operation can be performed.
It can be performed without labor and contributes to improvement of work efficiency. If the output of the pressure gauge 17 does not decrease to 1 kgf / cm ² or less even after the elapse of a predetermined time, the process does not proceed to the next step 2 as in the previous embodiment. The operation may be stopped by displaying the message.

In the circulation path shown in FIG. 2, the solenoid valve 12 and the solenoid valve 14 in the circulation path shown in FIG. 1 are eliminated, and the functions of the solenoid valve 12 and the solenoid valve 14 are replaced by a three-way valve 16. I have. The three-way valve 16 has a system in which there are two primary ports and one secondary port. When the apparatus is not operating, one of the two primary ports (normally open port). In the state where the device operates, the other port of the primary two ports (normally closed port) is communicated with the secondary side.
(Hereinafter referred to as NC side) communicates with the secondary side. That is, the NO side of the three-way valve 16 is connected to the ink supply path side, and the NC side of the three-way valve 16 is connected to the ink recovery path side.

Therefore, by employing the circulation path shown in FIG. 2, the number of solenoid valves constituting the circulation path can be reduced by one, and the installation space for the circulation system can be reduced, and the cost of the direct material can be reduced. In addition, power consumption can be reduced. In the case where the supply pump 4 is a pump using a check valve, if the three-way valve 16 is not used, the ink supply path becomes a completely closed system while the apparatus is stopped, and the ambient temperature becomes lower. When the pressure rises, the pressure rises due to the thermal expansion of the ink or residual air in the path, and as a result, the components constituting the supply path may be deteriorated or ink leakage may occur in the path. Three-way valve 16
When the NO side is connected, the ink supply path is always at the atmospheric pressure even when the apparatus is stopped, so that the above problem can be prevented from occurring. Note that FIG. 7 shows a basic configuration of an operation sequence in the circulation route of FIG. 2, and FIG. 8 shows an operation sequence in the case of abnormality determination. The abnormality determination and the processing procedure are the same as those described for the circulation path in FIG.

[0020]

According to the present invention, in an ink jet recording apparatus for generating ink particles by applying vibration to ejected ink, before ink is pressure-fed to nozzles,
Means for circulating ink in the ink supply path, detecting an output of a pressure sensor connected to the ink supply path, and preventing the ink from being ejected from the nozzles when the output of the pressure sensor exceeds a predetermined pressure. It is possible to detect abnormalities in the ink recovery system before ink is ejected from the nozzles, and to clean, repair, replace parts, etc. when recovering from abnormalities without soiling the print head and its surroundings with ink. Maintenance can be eliminated.

Further, even if the output of the pressure sensor rises above the predetermined pressure, the state is maintained for a predetermined time, and if the output of the pressure sensor drops to the predetermined pressure before the predetermined time has elapsed, By adopting a configuration in which ink is ejected from the nozzles, it is possible to perform a return from a mildly abnormal operation to a normal operation without troublesome labor, which contributes to an improvement in work efficiency.

Further, by connecting the NO side of the three-way valve to the ink supply path side and connecting the NC side of the three-way valve to the ink recovery path side, the number of solenoid valves constituting the circulation path is reduced by one. Thus, the installation space for the circulation system can be reduced, the cost of the direct material can be reduced, and the power consumption can be reduced. Further, the ink supply path is opened and not a closed path, so that an increase in pressure in the path due to an increase in ambient temperature can be prevented. Therefore, it is possible to improve the long-term reliability of the component parts constituting the ink supply path, and it is possible to accelerate the deterioration of the parts constituting the supply path and eliminate the cause of ink leakage in the path.

[Brief description of the drawings]

FIG. 1 is a diagram showing a circulation path of an ink jet recording apparatus to which a two-port solenoid valve according to an embodiment of the present invention is applied.

FIG. 2 is a diagram illustrating a circulation path of an inkjet recording apparatus to which a three-port solenoid valve is applied, which is one embodiment of the present invention.

FIG. 3 is a diagram showing a basic operation sequence of the embodiment shown in FIG. 1;

FIG. 4 is a diagram showing an operation sequence relating to an ink recovery system abnormality determination in the embodiment shown in FIG. 1;

FIG. 5 is an output diagram of the pressure sensor when the operation of the ink collection system is normal in one embodiment of the present invention.

FIG. 6 is a pressure sensor output diagram when an ink recovery system operation is abnormal in one embodiment of the present invention.

FIG. 7 is a diagram showing a basic operation sequence of the embodiment shown in FIG. 2;

FIG. 8 is a diagram showing an operation sequence relating to an ink recovery system abnormality determination in the embodiment shown in FIG. 2;

[Explanation of symbols]

1. Ink main container, 2. Ink, 3. Solenoid valve, 4.
Ink supply pump, 5: filter, 6: pressure reducing valve, 7: pressure gauge, 8: solenoid valve, 9: nozzle, 10: ink particles, 1
1 ... gutter, 12 ... solenoid valve, 13 ... ink recovery pump,
14: solenoid valve, 15: ink circulation path, 16: solenoid valve,
17 Control part.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C056 EA16 EA20 EB16 EB34 EC26 EC67 FA05 JC01 KB08 KB10 KB15 2C057 DB02 DD07 DE10

Claims (4)

[Claims] 1. An ink jet recording apparatus that performs recording by applying vibration to ejected ink to generate ink particles, and charging and deflecting the ink particles so that the ink particles reach a predetermined location on a recording medium. In the step before the ink is fed to the nozzle under pressure, the ink is circulated in the ink supply path, and the output of the pressure sensor connected to the ink supply path is detected, and the output of the pressure sensor becomes higher than a predetermined pressure. An ink jet recording apparatus comprising means for preventing ink from being ejected from a nozzle. 2. The method according to claim 1, wherein, even if the output of the pressure sensor rises above a predetermined pressure, if the output of the pressure sensor drops to a predetermined pressure before a predetermined time has elapsed.
When the ink is ejected from the nozzle and the output of the pressure sensor does not drop to a predetermined pressure even after the predetermined time has elapsed,
An ink jet recording apparatus comprising means for preventing ink from being ejected from a nozzle. 3. The electromagnetic valve according to claim 1, wherein a secondary path of an electromagnetic valve connected to a path branched from a supply path for supplying ink to the nozzle, and an electromagnetic valve connected to a recovery path for collecting ink. An ink jet recording apparatus in which the secondary paths are joined and connected to an ink recovery pump. 4. The method according to claim 1, wherein a path branched from a supply path for supplying ink to the nozzle is connected to a normally open port which is located on the primary side of the three-way valve and is opened when the apparatus is stopped. A collection path for collecting ink not used for printing is located on the primary side of the three-way valve and connected to a normally closed port that is opened during operation of the apparatus, and a path on the secondary side of the three-way valve is connected to an ink collection pump. Inkjet recording device connected to.