JPS62109655A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To conduct discharge recovery processing positively by providing a means through which a gas introduced from its midway of an ink supply path is discharged from a discharge opening together with ink and a foreign matter is removed. CONSTITUTION:When a three-way valve 72 is changed over first at a home position and an ink supply tube 17 is opened to atmosphere and left at it is for a fixed time, ink in the tube 17 flows down to a sub-tank 12, and air is introduced into the tube 17. The head 1 is capped by a joining section 3, the three-way valve 72 is returned to an original position and a solenoid valve 8 is closed, a lever is ON-operated and a vent valve 5A is closed, a pump 6 is ran and introduced air is sucked quickly, and ink is discharged from a discharge opening 2 at a sufficient flow rate by the large suction force of air, thus positively removing foreign matters such as bubbles remaining in a filter 30, etc. The solenoid valve 8 is opened and ink in the joining section 3 is sucked, and the lever 9 is OFF-operated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording device.

[Prior Art] In inkjet recording devices, droplets are ejected due to clogging of ink ejection ports such as orifices provided in the print head, or air bubbles entering the ink supply path leading to the ink ejection ports. Performance may deteriorate and ink ejection failure may occur.

Therefore, in conventional inkjet recording devices, a suction means is provided on the outside of the ejection port to face it, and the ink is caused to flow at a certain speed by sucking the ink from the ejection port or by pressurizing the inside of the ink supply path. By discharging from the discharge port, the cause of the discharge failure is removed.

[Problems to be solved by the invention] However, in inkjet recording devices, ejection ports,
Because the flow resistance is high at the print head, corners and steps in the supply path, and filters for removing foreign matter installed in the supply path, it is not possible to obtain a sufficient flow velocity. There was a problem in that only the ink was simply discharged without removing the air bubbles etc. that had accumulated therein, and the cause of the ejection failure could not be properly removed.

In addition, in order to eliminate such causes of discharge failure, it is possible to secure the flow rate by increasing the suction force by the suction means or the pressurizing force by the pressurizing means.
For this purpose, a problem arises in that the size of the apparatus cannot be avoided.

[Means for Solving the Problems] The present invention solves these problems and makes it possible to ensure a sufficient flow velocity without increasing the size of the device, thereby making it possible to perform reliable discharge recovery processing. The purpose is to provide an inkjet recording device.

Therefore, in the present invention, in an inkjet recording apparatus that performs recording by ejecting ink from an ejection port onto a recording medium, an introduction means for introducing gas from the middle of an ink supply path to the ejection port, and an introduction means for introducing gas from the middle of an ink supply path to the ejection port, and a The present invention is characterized in that it also includes a removing means for removing foreign matter in the ink supply path by discharging it from the ejection port.

[Function] That is, according to the present invention, ink is discharged at high speed together with the gas introduced into the ink supply path inside the ejection port, which not only prevents ejection failure factors such as ejection port clogging, but also
Foreign matter in the ink supply path leading to the ejection port, such as air bubbles and dust accumulated in the filter in the supply path, or in the gaps, corners, etc. of the supply path, can be appropriately removed.

[Example] The present invention will be described in detail below with reference to the drawings.

$1 Figures (A) and (B) are examples of the external configuration of an inkjet recording apparatus to which the present invention is applicable and the configuration of an operation panel provided on the front of the apparatus, and Figures 2 and 3 are examples of Figure 1 (A). ), and in this example, a so-called serial type inkjet recording device will be illustrated.

First, in FIG. 1(A), 1000 is the main body of the device, 1
100 is a power switch, and 1200 is an operation panel.

As shown in FIG. 12B, the operation panel 1200 includes an FF switch 1210 and an LF switch 1220 for the operator to instruct conveyance of a recording medium such as paper, and an LF switch 1220 for giving an online command to, for example, a mask device. In addition to command means such as an online switch 1230, display means such as an online lamp 1250 for displaying the online status of the device, an alarm lamp 1260 for reporting an abnormality, etc., and a ready lamp 1270 for reporting a ready state are provided. can be provided.

In FIGS. 2 and 3, l is a head that has an ink ejection port on the front surface facing the recording paper P, and a sub-tank 12 that supplies ink to the liquid chamber in the head l via a tube 17 and a shaft. 23 is attached to a carriage 22 that moves in the S direction in the figure, and in the process of movement, ink droplets are ejected from the ejection ports to record on the recording paper P whose recording surface is regulated by the platen 21. , 13 is an ink cartridge held detachably in the main body 1200, and has an ink bag 20 and a stopper 18 made of an elastic member inside, and a hollow needle 18 is inserted into the stopper 18 to an appropriate position. This establishes an ink flow path communication state with the sub-tank 12 via the supply tube 14.

Here, the ink supplied to the head 1 is maintained at a negative pressure compared to the water head at the ejection port. The water head of the ink to be supplied is always kept almost constant by the water level adjustment tube 15, and the ink is supplied to the ejection port side by surface tension, so the ink will not retreat from the ejection port. It also prevents ink from leaking.

Reference numeral 100 denotes a cap device that is disposed, for example, at the home position of the carriage 22, and caps the head 1 when the carriage 22 is positioned at the home position. In this cap device 100, 3 is made of an elastic member that can be joined to the front surface of the spatula 1, and has a cap 3A for protecting the ejection port during non-recording. 7A and 7B are the joint parts 3 and 3, respectively. These are gears and cams for positioning the gears that constitute a joint conveyance mechanism for conveying the head 1 in the T direction in the figure to connect/detach it from the head 1. This joining/separation positioning is performed, for example, by turning the contact 11B of the switch 11 on/off using the cam 7B.
This can be done by turning it off.

6 is a pump as a suction means, and tube 1 is used to maintain the ink level in the tube 4 and sub tank 12.
5 is connected to the interior of the joint 3 and the interior of the sub-tank 12 for suction, and 8 is an atmospheric release tube 5.
This is an opening/closing means disposed in the joint part 3 for opening the inside of the joint part 3 to a large extent, and for example, a solenoid valve can be used. Also,
For example, a closable ventilation valve is provided between the solenoid valve 8 of the tube 5 and the joint 3. Reference numeral 9 is an operating lever that engages the ventilation valve with the closable portion and the pump contact 8A to pump the pump. It has a disaster 8A that drives 6.

In this example, a lever control member including, for example, a spring or a latch is provided so that the lever 9 can be set to the on position, the off position, and an intermediate position therebetween, and after the lever 9 is moved from the off position to the on position. When the operation is released, it is held at an intermediate position, and when the operation is released after a movement operation from the intermediate position to the on position, it is returned to the off position. In the on position, the vent valve 5A is closed and the pump bride point 8A is lowered to the lowest position to perform suction operation, and in the intermediate position, the vent valve 5A is closed.
Pump contact 8A returns with A closed, and in the off position, vent valve 5A is open and pump contact 6A remains closed.
The engagement with the disaster 8A is released.

Further, as will be described later, the output of the switch 11 and the movement position of the lever 9 are detected by the control section, and the conveyance of the joint 3, the drive of the electromagnetic valve 8, etc. are controlled.

FIG. 4 shows an example of the configuration of the main part of the present invention. Here, a three-way valve 7 is installed in the middle of the supply tube 17, for example, at a position close to the discharge port 2, that is, at a position between the head l and the filter 30.
2, so that the inside of the supply tube 17 can be opened to the atmosphere. This three-way valve 72 is normally in a state where the atmosphere side is closed, and the supply pipe 17 can supply ink to the nozzle.

Atmospheric release tube 5! F) The ventilation valve 5A installed in the middle is
In response to the operation of the operating lever 9, the portion 9B can be closed. The ink absorber 3B, which is provided within the cap 3A and is capable of retaining ink, can be made of, for example, a porous material with liquid absorption properties. In addition.

The cap 3A can generally be made of various rubber materials such as silicone rubber and butyl rubber.

Fill 5!3 arranged in the middle of the ink supply tube 17
0 collects foreign matter such as dust in the supplied ink and prevents foreign matter from flowing into the recording head side. Ink cartridge 13
A waste ink absorber 18 disposed in the waste ink absorber 18 receives the waste ink sucked by the pump 6 via the waste ink tube 10 .

FIG. 5 shows an example of the configuration of the control system of the apparatus according to the embodiment shown in FIG. 400 is a control unit in the form of a microcomputer having, for example, cpυ, ROM, RAM, etc.;
Each part is controlled according to the processing procedures stored in the OM, and the head l is
drive to record. Further, in response to paper detection by a paper sensor PS that detects the recording paper P, the control unit 400 controls paper feeding by driving the platen roller 21 via a paper feeding mechanism 21A including a paper feeding motor. Furthermore, in accordance with the carriage position information detected by the carriage position sensor C8, the control unit 400 controls the drive of the carriage 22 and the positioning to the home position etc. via the carriage motor 22A.

Further, the control unit 400 uses a conveyance mechanism 7 having a drive member such as a motor for conveying the joint part 3 in addition to the gear 7A and the cam 7B, and uses the conveyance mechanism 7 to move the joint part 3 to the head 1 according to a contact signal from the switch 11. Perform positioning. Reference numerals 1205 and 1255 indicate command means and display means, respectively, provided on the operation panel shown in FIG. 1(B). The position sensor LS can be arranged in conjunction with the lever 9, for example the pump contact 6A. In addition, the control unit 400 controls switching of the three-way valve 72 during the recovery process.

FIG. 6 shows an example of a recovery processing procedure by the control unit 400 shown in FIG.

When power is turned on or when discharge performance deteriorates and recovery operation is required,
First, in step 5201, the three-way valve 72 is switched to open the tube 17 to the atmosphere, and in step 5203, the process waits for a predetermined time. At this time, the ink in the supply tube 17 is under negative pressure, so as a result of the opening, it retreats toward the sub-tank 12 and air enters the supply tube 17. After this step 52
At step 05, the cap 3A is joined, and at step 5207, the solenoid valve 8 is closed, and at step 5209, the pump 6 is operated.

At this time, the supply tube 17 is filled with air, so if negative pressure suction is performed by the pump 6 in this state, the air is discharged from the discharge port 2, and the flow path resistance is substantially reduced. This results in a large amount of suction power. Therefore, the cause of the ejection failure in the ink supply path from the sub-tank 12 to the ejection port 2, that is, the foreign matter such as air bubbles accumulated in the filter 30 and the two-step corner portion is reliably removed.

In the configuration shown in FIG. 4, a three-way valve for switching the flow path is provided between the filter 30 of the ink supply tube 17 and the head l, but instead of this, a solenoid valve or the like for opening the flow path is provided. A means may be provided. Alternatively, as shown by the broken line in FIG. 4, it may be provided at a position between the filter 30 of the ink supply tube and the sub-tank 12. Further, it may be provided at a position where the liquid chamber in the head 1 can be opened, for example, at a position shown by a broken line in the figure. Furthermore, such opening means may be manually operated by an operator during recovery processing.

Furthermore, if the pump 6 is operated to suck ink from the discharge port 2 while the supply tube 17 is open to the atmosphere, the effect of this example will be even greater. In addition, this example can be effectively applied to an apparatus that does not supply ink under negative pressure. Furthermore, air may be introduced by appropriate pressurizing means via a three-way valve or the like.

In the above description, the present invention has been applied to a serial type inkjet recording device, but it goes without saying that the present invention can be applied to any type of inkjet recording device that performs recording by ejecting ink through ejection ports. . For example, it may be a full multi-type device that includes a plurality of ejection units in the width direction of the recording paper.

Further, in the above description, the pump and the like are operated manually, but it is also easy to operate them in the control process using an appropriate drive means.

Effects of the Invention] As described above, according to the present invention, it is possible to realize an inkjet recording apparatus that can secure a sufficient flow velocity and perform reliable ejection recovery processing without increasing the size of the apparatus.

[Brief explanation of drawings]

1(A) and CB) are a perspective view and a front view showing an example of the appearance of an inkjet recording apparatus to which the present invention is applicable and an example of the configuration of an operation panel provided on the front of the apparatus, and FIGS. 2 and 3 are , respectively, are a perspective view and a plan view showing an example of a configuration of a recording section housed in the apparatus shown in FIG. FIG. 4 is a block diagram showing a configuration example of a control system in the embodiment shown in FIG. 4; FIG. 6 is a flowchart showing an example of a recovery processing procedure by the control system shown in FIG. l...head, 2...discharge port, 3...junction, 3A...cap, 3B...ink absorber, 4.15...ink suction tube. 5... Atmospheric release tube, 5A... Ventilation valve, 6... Pump, 8A... Pump contact, 7... Joint conveyance mechanism, 8... Solenoid valve, 9... Operation lever , lO...Waste ink tube. 12... Sub tank, 13... Ink cartridge, 14.17... Ink supply tube, 16... Waste ink absorber, 30... Filter 72... Three-way switching valve, 400... Control m section, 1000...apparatus main body, 1200...operation panel.

Claims (1)

[Scope of Claims] 1) In an inkjet recording apparatus that performs recording by ejecting ink from an ejection port onto a recording medium, an introduction means for introducing gas from the middle of an ink supply path to the ejection port;
An inkjet recording apparatus comprising: a removing means for removing foreign matter in the ink supply path by discharging the introduced gas from the ejection port together with the ink. 2) The inkjet recording apparatus according to claim 1, wherein the introduction means includes an opening means that can open the middle of the ink supply path to the atmosphere. 3) An inkjet recording apparatus according to claim 1 or 2, wherein the ejection means includes a suction means that is connected to the ejection port and performs suction. 4) In the inkjet recording apparatus according to any one of claims 1 to 3, the ink supply path includes an ink storage member as an ink supply source;
a storage member that temporarily stores ink supplied from the ink storage member and supplies it to the ejection port, and the introduction means introduces the gas into the ink supply path between the storage member and the ejection port. An inkjet recording device characterized by introducing.