JPS62109651A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To conduct discharge recovery processing positively by pushing a gas into a discharge opening through the repetition of joining/separation to the discharge opening of a joining means and driving a discharge means before the joining of the joining 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 insides 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 positioned at a neutral position and the pump 6 is stopped with the vent valve 5A left closed, joining and separation between a cap 3A consisting of an elastic material and the discharge opening 2 are repeated several times, and air is pushed into the head 1 and further into a supply tube 17, but the pump 6 is operated before the joining of the cap 3A and leakage from an ink absorber 3B is recovered. The lever 9 is ON- operated and the pump 6 is operated, ink is sucked together with air quickly, and foreign matters such as bubbles remaining in a filter 30, etc. are removed positively by the large suction force of ink.

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 by ensuring sufficient flow velocity and flexibility 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 that can.

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 a joining means that can be joined to the ejection port, and a joining means that is connected to and detached from the ejection port. a conveyance means, a control means for controlling the conveyance means to join and separate the joining means from the discharge port, and for forcing and introducing gas into the discharge port by joining; The present invention is characterized in that it includes a discharge means for discharging more gas, and a discharge control means for driving the discharge means by joining the joining means to the discharge port before joining for forcing and introducing the gas.

[Function] That is, according to the present invention, the ink is discharged and filled in the joining means before the gas is forced into the ink by repeating joining and separating, so that sufficient pressurizing force can be obtained for the forced introduction, and the ink is discharged. Since the ink is discharged at high speed together with the gas introduced into the ink supply path inside the mouth, it is not only possible to prevent ejection failures such as clogging of the ejection port, but also foreign matter in the ink supply path leading to the ejection port, such as foreign matter in the supply path. This makes it possible to appropriately remove air bubbles, dust, etc. that have accumulated in the filter, steps, corners, etc. of the supply route.

[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 is applied and the configuration of an operation panel provided on the front of the apparatus, and FIGS. An example of the configuration of a recording section housed inside the apparatus shown in A) is shown, and in this example, a so-called serial type inkjet recording apparatus is 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 the 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, and a digital lamp 1270 for reporting the ready status are provided. can be provided.

2 and 3, reference numeral 1 denotes a head having 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, as well as 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. . Reference numeral 13 denotes an ink cartridge that is detachably held in the main body 1200, and has an ink bag 20 and a stopper 18 made of an elastic member inside.The supply tube is opened by inserting the hollow needle 18 into the stopper 1B to an appropriate position. An ink flow path communication state with the sub-tank 12 is obtained via the sub-tank 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 head l, and 7A and 7B are joint parts each having a cap 3A 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 in the T direction in the figure to connect/separate the head 1. This joining/W# release positioning can be done, 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 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 joint 3. Reference numeral 9 is an operating lever that engages the ventilation valve with the closable portion and the pump contact 6A to pump the pump. It has a protrusion 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 contacts 6A are lowered to the lowest position to perform suction operation, and in the intermediate position, the vent valve 5A is closed.
Pump contact 6A returns with A closed, and in the off position, vent valve 5A is open and pump contact 8A remains closed.
The engagement with Kuki 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 unreleased device. In this example, air is introduced into the recording drum by applying pressure from the outside of the discharge port, and then suction is performed using the pump 6. By doing so, the discharge recovery process is performed, and when pressurizing, the joint portion 3 is repeatedly joined/disconnected from the head 1.

In the figure, 5A is an air valve provided in the middle of the atmosphere opening tube 5, and can be closed by its portion 8B in response to the operation of the operating lever 9. 3B is an ink absorber that is provided in the gap and can hold ink, and can be made of, for example, a porous material with liquid absorbing properties. Note that the cap 3A can generally be 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 layer 1 side. Reference numeral 18 denotes a waste ink absorber disposed in the ink cartridge 13, which absorbs waste ink sucked by the pump 6 into the waste ink tube 10.
Accept through.

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, CPU, RO), RAM
A control unit in the form of a microcomputer having
Each unit is controlled according to the processing procedure stored in the RO)I, and the head 1 is driven to record image data received from a host device or the like. PS is a paper sensor that detects the recording paper P, and in response to the detection, the control unit 200 controls paper feeding by driving the platen roller 21 via a paper feeding mechanism 21A including a paper feeding motor. O8 is a carriage position sensor, and according to the detected position information, the control @ 200 controls the drive of the carriage 22 and the positioning to the home position etc. via the carriage motor 22A.

Reference numeral 7 denotes a conveyance mechanism that includes a drive member such as a motor for conveying the joint 3 in addition to a gear 7A and a cam 7B. Reference numerals 1205 and 1255 represent command means and 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 8A.

FIG. 6 shows an example of a recovery processing procedure by the control section 200 shown in FIG. 5, and FIGS. 7 to 9 show examples of operations of each part in the processing.

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 l in step S1 of FIG. 6 to perform capping. Then, in step S3, the operator moves the lever 9 from the off position to the on position (point A in FIG. 7), and after waiting for a predetermined period of time until the alarm lamp stops flashing in step S5, the operator moves the lever 9 from the off position to the on position (point A in FIG. Release the operation of lever 9 with . 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 Sll, the joint conveyance mechanism 7 is controlled to repeat joining/separating the cap 3A and the discharge port 2 several times (
During period B) in FIG. 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 1280 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 is moved to the on position in step S17. Then step S1
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 ink is suctioned and the inside of the cap 3A and the suction tube 4 are filled with ink in steps S3 to S7 is to ensure that the pressurizing force due to bonding is applied to the ejection port 2 when air is introduced to the rear of the ejection port 2. This is to ensure that. 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 sealed with the cap 3A and the vent valve 5A and the solenoid valve 8 closed, FIGS.
When Boise 6 is turned on (operating state) at time E in the diagram,
Suction is performed through the suction tube 4, negative pressure (ink suction negative pressure) is generated within the cap 3A and the atmosphere release tube 5, and suction processing from the ejection 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. Therefore, ink suction is not performed after time F.

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 Further, the time FE, that is, the ink suction time, may be controlled by a timer that controls the opening and closing of the electromagnetic valve.The time FE, that is, the ink suction time, can be appropriately changed 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 once, 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 L is
Configure A as follows.

Figure 10 (A), (B) and (C) are head front IA
Figure 0 (A), which is three examples of configurations, is a general configuration example of the head front surface IA, and such a configuration may be used if the air introduction process is not urgent. If desired, a dummy ejection port 2A, which has a larger cross-sectional area than the ejection port 2 and is not used for actual recording, is provided as shown in FIGS. good.

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 2A 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. DESCRIPTION OF SYMBOLS 1...Head, 2...Discharge port, 3...Joint part, 3A...Cap, 3B...Ink absorber, 4.15...Ink suction tube, 5...Atmospheric release Tube, 5A...Vent valve, 6...Pump, 6A...Pump contact, 7...Joint conveyance mechanism, 8...Solenoid valve, 9...Operation lever, 10...Disposal Ink tube, 12... Sub tank, 1 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.

Claims (1)

[Scope of Claims] 1) An inkjet recording apparatus that performs recording by ejecting ink from an ejection port onto a recording medium, comprising: a joining means that can be joined to the ejection port; and a joining means that is connected to the ejection port. a conveying means for joining and separating; a control means for controlling the conveying means to perform the joining and the separating of the joining means to the discharge port; and a control means for forcing and introducing gas into the discharge port by joining. a discharge means for discharging the fluid inside the discharge port from the discharge port; and a discharge control means for joining the joining means to the discharge port and driving the discharge means before joining for the forced introduction. An inkjet recording device characterized by comprising: 2) An inkjet recording apparatus according to claim 1, wherein the ejection means has a suction means connected to the rear of the joining means.