JPS62109649A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To conduct discharge recovery processing positively by controlling a carrier means, performing joining to a discharge opening of a joining means, pushing a gas into the discharge opening and sucking the gas from the discharge opening by a suction means. CONSTITUTION:A head 1 is capped by a joining section 3 at a home position, a lever 9 is ON-operated and a pump 6 is operated, a vent valve 5A is closed, the inside of the joining section 3 and a suction tube 4 are filled with ink through suction from a discharge opening 2, and excess filling is prevented by opening a solenoid valve 8. The lever 9 is released, a joining-section carrier mechanism is controlled to repeat joining/separation between a cap 3A and the discharge opening 2 several times, and air is fed into the head 1 and further into a supply tube 17 by the elasticity of the cap 3A. The lever 9 is ON- operated, and ink is sucked together with air at a stroke through the suction working of the pump 6, thus positively removing foreign matters such as bubbles remaining in a filter 30 and at corner sections and stepped sections with large suction force.

Description

Detailed Description of the Invention (Hereinafter, blank) 3. Detailed Description of the Invention II [Industrial Application Field] 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 sucked from the ejection port or the ink is supplied at a certain speed by pressurizing the inside of the ink supply path. By discharging from the sink discharge port, the cause of the discharge failure is eliminated.

[Problems to be solved by the invention] However, in inkjet recording devices, ejection ports,
Because of the flow path resistance at the print head, corners, steps, and filters installed in the supply path to remove foreign matter, it is not possible to obtain a sufficient flow velocity. There was a problem in that the air bubbles and the like that had accumulated in those areas were not discharged, but only the ink was discharged, 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 applying suction force by a suction means or pressurizing force by a 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 present 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, there is provided an introduction means for introducing gas under pressure inward from the ejection port, and an introduction means for introducing gas under pressure into the recording medium along with the ink. It is characterized by comprising a discharge means for discharging from the discharge 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, steps, 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.

FIGS. 1(A) and 3(B) show an example of the external configuration of an inkjet recording apparatus to which the present invention can be applied and the configuration of an operation panel provided on the front of the apparatus, and FIGS. 2 and 3 are examples of FIG. ) An example of the configuration of a recording section housed inside the apparatus shown in FIG.

First, in FIG. 1(A), 1000 is the device main body 11.
00 is a power switch, and 1200 is an operation panel. On the operation panel 1200, as shown in FIG.
FF switch 121O1L F switch 1220,
and a command means such as an online ramp 1230 for providing an online command with the mask device, for example.
Online lamp 1250 for displaying the online status of the device, alarm lamp 1 for notifying abnormalities etc.
260, and a display means such as a ready lamp 1270 for notifying the ready state.

2 and 3, reference numeral 1 denotes a head having ink discharge 1 on the front surface facing the recording paper P, together with a sub-tank 12 that supplies ink to the liquid chamber in the head 1 via a tube 17. It is attached to a gear ridge 22 that moves on a shaft 23 in the S direction in the figure, and by ejecting ink droplets from the ejection port based on the movement of the gear ridge 22,
Recording is performed on a recording paper P whose recording surface is regulated by a platen 21. 13 is an ink cartridge detachably held in the main body 1200, and has an ink bag 20 and a stopper 19 made of an elastic member inside. By inserting the hollow needle 18 into the stopper 19 to an appropriate position, the ink flow path is communicated 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 supplied ink is always kept substantially constant by the water level adjustment tube 15, and the ink is supplied toward the ejection port by surface tension, so that the ink does not retreat from the ejection port. Furthermore, it also prevents ink from leaking from the ejection ports due to vibrations or the like.

A cap device 100 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, numeral 3 is an elastic member that can be joined to the front surface of the head 1, and 7A and 7B are joint parts each having a cap 38 for protecting the ejection port during non-recording. These are gears and cams for positioning the gears that constitute a joint transport mechanism for transporting the head 1 in the T direction in the figure to perform joining/detachment with the head 1. This junction/ll! This positioning can be performed, for example, by turning on/off the contact 1111 of the switch 11 using the cam 7B.

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 to the inside of the joint part 3 and the inside of the sub-tank 12, respectively, to perform suction. 8 is atmosphere 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 the atmosphere, and for example, a solenoid valve can be used. Also,
For example, a closable ventilation valve is provided between the electromagnetic valve 8 of the tube 5 and the junction 3. Reference numeral 9 denotes an operating lever, which has a portion that can close the vent valve and a protrusion 98 that engages with the pump contact 68 to drive the pump 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 between them, and the lever 9 can be moved from the off position to the on position. When the operation is released after the operation, it is held at the intermediate position, and furthermore, when the operation is canceled after the movement operation from the intermediate position to the on position is performed, it is returned to the off position. In the on position, the vent valve 5A is closed and the pump contact 68 is lowered to the lowest position to perform a suction operation, and in the intermediate position, the pump contact 6A returns while the vent valve 5A is closed, and the pump contact 68 is in the off position. In this case, the vent valve 5A is opened and the pump contact 6 is opened.
The engagement between A and the protrusion 9A is made to be 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 apparatus of the present invention. In this example, air is introduced into the recording head 1 by applying pressure from the outside of the discharge port, and then suction is performed by the pump 6. The discharge recovery process is carried out by the following steps, and when pressurizing, the joint part 3 is connected to the head 1 by /l! lI
This is done by repeating t-removal.

In the figure, the air valve is provided in the middle of the air release tube 5 at the fifth shoulder, and can be closed by a portion 911 in response to the operation of the operating lever 9. 3B is an ink absorber that is provided on the cap 38 and can hold ink, and can be made of, for example, a porous material with liquid absorption properties. Incidentally, the cap 3 can be generally made of various rubber materials such as silicone rubber and butyl rubber.

Reference numeral 30 denotes a filter disposed in the middle of the ink supply tube 17, which collects foreign matter such as dust in the supplied ink and prevents foreign matter from flowing into the recording head 1 side. Reference numeral 16 denotes a waste ink absorber disposed in the ink cartridge 13, which receives waste ink sucked by the pump 6 through 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. 200 is, for example, a CPU, 10M, and a RAM.
A control unit in the form of a microcomputer having
1 (Controls each part according to the processing procedure etc. stored in the OM, and drives the head 1 to record according to the image data received from the host device etc. PS is a paper sensor that detects the recording paper P, etc., the control unit 200 drives the platen roller 21 via a paper feed mechanism 21A including a paper feed motor to control paper feed.C5 is a carriage position sensor, and controls the paper feed according to the detected position information. The unit 200 controls the driving of the carriage 22 and the positioning of the carriage 22 to a home position etc. via a carriage motor 22A.

Reference numeral 7 denotes a conveyance mechanism that includes a gear 7A, a cam 7B, and other driving members such as a motor for conveying the joint 3. The control unit 200 controls the positioning of the joint with respect to the head 1 in accordance with a contact signal from the switch 11. conduct. 1205 and 1
Reference numerals 255 denote a command means and a display means, respectively, provided on the operation panel shown in FIG. 1(B). LS is a position sensor of the lever 9, which can be arranged, for example, in connection with the pump contact.

FIG. 6 shows an example of a recovery processing procedure by the control unit 200 shown in FIG.

First, when the carriage 22 is positioned at the home position at an appropriate timing such as when the power is turned on or during recording processing, the bonding portion 3 is moved relative to the head 1 in step s1 of FIG. 6 to perform capping. In this state, the operator moves the lever 9 from the off position to the on position in step S3 (point A in FIG. 7), and waits for a predetermined time until the alarm lamp stops flashing in step S5. In step S7, the lever 9 is released. When moving to the on position, suction processing from the ejection port 2 is performed, and the joint portion 3 and the suction tube 4 are filled with ink. At this time, excessive filling is prevented by opening the solenoid valve 8 for a predetermined time (period B in FIG. 7) in step S9.

Next, in step 511, the joint conveyance mechanism 7 is controlled to repeat the joining/separation of the cap 3^ and the discharge port 2 several times (
Period B) in Figure 7. At this time, the cap 3 which is an elastic body
A causes air to be sent into the head 1 through the discharge port 2. Also, inside the cap 3A and tube 4
The inside is filled with ink, reducing the volume of the pushing part, and the filled ink acts as an elastic body, so air is pushed in effectively. In connection with the air introduction process in step Sll, as shown in FIG. It is possible to remove the negative pressure that momentarily occurs at the joint immediately before the process, thereby preventing the introduced air from being discharged (advancing the meniscus) and preventing the ink from scattering.

Next, in step S13, the alarm lamp 1260 and the online lamp 1250 are blinked alternately to notify the operator of the end of the air introduction process. Then,
For example, when the operator moves the lever 9 from the intermediate position to the on position in step 515 (time point E) after a predetermined period of time (time point F), the suction process is started, and after a predetermined time period (time point F), the solenoid valve 9 to open. Then step 51
The operator turns off the lever 9 in step S9, and closes the solenoid valve 8 in step S21.

At this time, air is introduced behind the discharge port 2, that is, into the head 1 and the supply tube 17, so when negative pressure suction is performed by the pump 6 in this state, - air is introduced from the discharge port 2. The flow path resistance is substantially reduced and a large suction force is obtained. 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 corner 9 steps, is reliably removed.

Note that the reason why the ink is suctioned and the inside of the cap 3 shoulder 5 and the suction duplex 4 are filled with ink in the processing of steps S3 to S7 is to ensure that the pressurizing force due to bonding is applied to the discharge port 2 when air is introduced to the rear of the discharge port 2. This is to ensure that the Further, the reason why the timing of opening the solenoid valve 8 is delayed relative to the timing of turning on the lever 9 in the process of step S17 is as follows.

With the discharge port 2 tightly closed with the cap 38 and the vent valve 5A and the solenoid valve 8 closed, the pump 6 is turned on (operating state) at time E in FIGS. 7, 8, and 9. ), suction is performed through the suction tube 4 and negative pressure (ink suction negative pressure) is created in the cap 3A and the atmosphere release tube 5.
is generated, and suction processing from the discharge port 2 is performed.

At this time, the ink sucked together with air from the ejection port 2 fills the inside of the cap 3A and leaks from the ink absorber 3B. Further, the atmosphere-opening tube 5 may also be filled with ink. However, if this state remains as it is, subsequent ink ejection will be adversely affected.

Therefore, in this example, a time point F after a predetermined period of time has elapsed from time point E.
Then, the solenoid valve 8 is turned on (opened) to communicate the atmosphere release tube 5 with the atmosphere. Then, the ink leaking from the ink absorber 3B and the ink in the atmosphere release tube 5 are sent to the pump 6 via the suction tube 4.

As shown in Fig. 9, the pressure inside the cap 3^ (suction pressure waveform) becomes negative pressure with a slight rising angle at the time E when the pump 6 is turned on, and when the solenoid valve 8 is turned on (opened). At F, the pressure suddenly returns to atmospheric pressure. However, after time F, ink suction is not performed.

Here, the time (F-E) from the time point E when the pump 6 is turned on to the time point F when the solenoid valve 8 is turned on is determined by the control unit 200.
can be controlled by Alternatively, the control may be performed using a timer that controls the opening and closing of the electromagnetic valve. This time FE, that is, the ink suction time, can be changed appropriately by adjusting the control section 200 or the timer.

In the above embodiments, the lever 9 is operated manually by the operator, but it may be done by providing appropriate command means and driving means, or by providing a driving means and operated during the control process. Furthermore, even when the operation is performed manually, the recovery operation can be simplified by providing a start switch or the like to start from the broken line at point A in FIGS. 7 and 8. can.

In addition, the pressurization for pushing air through the discharge port is performed by the cap 3A to prevent clogging of the nozzle and the incorporation of dust, etc., but the discharge port 2 is separate from the cap 3A.
A pressurized cap may be provided to force air in.

Furthermore, as long as sufficient air can be introduced in one joining, only one joining operation may be performed without repeating joining.

In the above embodiment, air is introduced from the outside of the discharge port 2, but as mentioned above, there is a large flow path resistance in the discharge port 2, so the air introduction process cannot be performed quickly. It is possible that Therefore, in this example, the front surface I of the head 1 is
Configure A as follows.

FIGS. 10(8), (B) and (C) show three examples of the configuration of the head front surface IA. (A) in the figure is a general configuration example for the head front surface 1, and such a configuration may be used when the air introduction process is not urgent. However, if you desire quick and reliable introduction,
), it is sufficient to provide a dummy ejection port 2A that has a larger cross-sectional area than the ejection port 2 and is not used for actual recording.

In other words, the holding force of the meniscus at the discharge port is determined by surface tension, so the larger the cross-sectional area (radius r in the case of a circular discharge port), the smaller the holding force of the meniscus.
Therefore, air can be easily taken in when pressurized or negative pressure is introduced. It goes without saying that the number and location of the dummy discharge ports 2^ can be selected as desired.

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 1(B) are a perspective view and a front view showing an example of the external 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 1A is a perspective view and a plan view showing an example of the configuration of a recording unit housed in the device shown in FIG. 1A, respectively. FIG. FIG. 5 is a block diagram showing an example of the configuration of the control system in the embodiment shown in FIG. 4, and FIG. A flowchart showing an example, and FIGS. 7 to 9 are front views showing three examples of the configuration of the front surface of the head in each of the recovery processes. 1...Head, 2...Discharge port, 3...Joint part, 3Δ...Cap, 3B...Ink absorber, 4.15...Ink suction tube, 5...Atmospheric release Duplex, 5A...Vent valve, 6...Pump, 6Δ...Pump contact, 7...Joint portion conveyance mechanism, 8...Solenoid valve, 9...Operation lever, 10...Disposal Ink tube, 12... Sub tank, 13... Ink cartridge, 14. 17... Ink supply tube, 16... Waste ink absorber, 20... Ink bag, 22... Carriage, 30. ...Filter, 200...Control unit, 1000...Device main body, 1200...Operation panel. -ri 1cm (C)

Claims (1)

[Scope of Claims] 1) In an inkjet recording apparatus that performs recording by discharging ink from a discharge port onto a recording medium, an introduction means for introducing gas under pressure inward from the discharge port; An inkjet recording apparatus comprising: a discharge means for discharging gas from the discharge port together with ink. 2) In the inkjet recording apparatus according to claim 1, the introducing means includes a joining means that can be joined to the ejection port, a conveying means that joins and detaches the joining means from the ejection port, and An inkjet recording apparatus comprising: a control means for forcing and introducing the gas into the ejection opening by controlling a conveying means to cause the joining of the joining means to the ejection opening. 3) An inkjet recording apparatus according to claim 1 or 2, wherein the ejection means has a suction means connected to the rear of the joining means. 4) The inkjet recording apparatus according to any one of claims 1 to 3, wherein the joining means has a cap that protects the ejection port during non-recording. Recording device.