JP3024368B2 - Cleaning device for inkjet recording head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device for an ink jet recording head.

[0002]

2. Description of the Related Art An ink jet recording head mounted on an ink jet printer (hereinafter simply referred to as a head).
The ink discharge surface is contaminated by ink splash, thickened ink, paper dust, dust, ink pool generated near the ink discharge port, and the like. These stains cause the occurrence of white streaks due to non-ejection of ink, the occurrence of dot defects due to ejection failures such as deterioration of the ink flying shape and deviation in the ink flying direction, and the like, and the occurrence of printing defects unique to the inkjet head.

FIG. 6 shows the periphery of the ink discharge port 13 of the head 1 and shows the degree of contamination of the head 1 when recording is continued without cleaning the ink discharge port surface 16 at all. Fine ink droplets adhere to the entire surface of the ink ejection surface 16. When these minute ink droplets aggregate and grow,
The ink pool 21 is formed. Such ink droplets and ink pools 21 grow further and become larger, or move on the ink discharge port surface 16 and cover the ink discharge ports 13 due to high-speed movement of the head 1 accompanying printing.

[0004] When the ink ejection port 13 is covered with ink droplets or the like, the ink flying shape is deteriorated, and the ink flying direction is deviated, resulting in defective ink ejection or ink non-ejection. In addition, when the large ink reservoir 21 covers the plurality of ink ejection ports 13, the above-described ejection failure and printing failure due to non-ejection rapidly increase.

Therefore, various types of cleaning devices have been conventionally proposed as cleaning devices for always keeping the ink discharge port surface 16 in a normal state. One example is shown in FIG. At the time of non-printing, the head 1 mounted on the carriage 2 returns to the home position HP, the head 1 is capped by the capping device 22, and the drying of the ink is prevented. The ink suction recovery device 23 includes the capping device 22.
Is composed of a tube 24 and a pump 25 leading to
The air inside the capping device 22 is sucked to make a negative pressure, and the ink is ejected from the ink ejection port 13 of the head 1 so as to recover the clogging of the ink ejection port 13.

The capping device 22 is provided with a roll-shaped wiping mechanism 26 and a plate-shaped wiping blade 27. With these two types of wiping mechanisms, the ink discharge port surface 16 is kept clean. That is, the wiping mechanism 26 is made of, for example, a continuous porous material having excellent absorbency for cloth or ink, and as shown in FIG. Absorb and remove.

The wiping blade 27 is made of an elastic material such as silicone rubber or urethane, and slides on the ink discharge port surface 16 as shown in FIG. Paper dust, dust 29, etc. are flipped and removed. When the dirt on the surface of the head 1 is removed by these wiping mechanisms, the surface of the head 1 becomes as shown in FIG. Compared to FIG. 6 before cleaning, the amount of ink adhered around the ink ejection port 13 is small and good, but it is impossible to completely wipe off dirt, which may cause residual ink non-ejection or ejection failure. was there.

The following is a classification of the method of cleaning the ink ejection port surface other than the conventional example. (1) Devise the material of the wiping member Use a material having water absorption, water repellency, and elasticity, or adjust the pore diameter and porosity of the continuous porous material. (2) Deviation of Wiping Member Mounting Method and Wiping Method The relationship between the arrangement direction of the ink ejection ports and the wiping direction, that is, one of parallel, orthogonal, and oblique is selected. (3) Timing and frequency of wiping (4) Adoption of nozzle opening cleaning liquid

[0009]

However, the effect of any of these proposals is substantially the same as the situation shown in FIG. 10, or the mechanism is complicated and the cost is high in practical use. Room remains. Therefore, the present invention has focused on the fact that the factor that hinders the cleaning of the ink ejection port surface is the behavior of the dried ink. That is, the ink remaining on the ink ejection port surface and the ink adhering to and absorbed by the wiping member are dried and have increased viscosity, which is considered to cause the following adverse effects.

(1) Even with a wiping member having good ink absorbency, the absorbability of ink with increased viscosity, that is, thickened ink is reduced, and ink wiping residue on the ink ejection port surface is likely to occur. Become.

(2) With respect to the thickened ink, uneven wiping easily occurs even with the elastic plate-shaped wiping blade 27 shown in FIG. 9 and is raked up at the edge portion in the wiping direction as shown in FIG. Or, it is pushed into the ink ejection port 13. Wiping the ink with the thickened ink attached to the wiping member applies the thickened ink to the ink ejection port surface 16, which often has the opposite effect.

(3) Therefore, the ink discharge port surface 16 of the head 1 may be treated with a water repellent in order to make it difficult for the ink to spread to the ink discharge port surface 16 or to easily wipe the ink. In this case, the wiping member applies the thickened ink to the ink discharge port surface 16, and as a result, the effect of the water repellent is significantly impaired, and discharge failures are more likely to occur.

(4) In a head in which the ink ejection port face 16 is improved in hydrophilicity so that the ink spreads as a uniform layer on the ink ejection port face, the applied thickened ink locally spreads the ink. This causes an uneven ink layer to be formed around the ink ejection port surface 16 and the ejection failure is likely to occur.

The adverse effect of the thickened ink has been described above. However, the dirt on the normal ink ejection port surface is a mixture of paper powder, dust and the like and the ink. In this case, the cleaning is performed only with the thickened ink. It is even more difficult than in the case. Therefore, in order to maintain the stable ejection of the ink by removing the adhesion of the thickened ink, the paper dust and the dust, the ink suction recovery device 23 shown in FIG. 7 has conventionally been used.

The ink suction / recovery device 23 not only removes air bubbles and foreign matter in the ink ejection port 13 but also flushes out paper dust and dust adhering to cover the ink ejection port 13 with new ink to discharge ink. A great effect of cleaning the outlet surface 16 can be obtained. However, on the other hand, if the operation frequency of the device 23 is increased, the ink consumption during non-printing increases, which is disadvantageous in that it is uneconomical. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to efficiently clean an ink ejection port surface to stabilize ink ejection and reduce consumption of excess ink. An object of the present invention is to provide a cleaning device for an ink jet head which can perform the following.

[0016]

In order to achieve the above object, a first aspect of the present invention is to provide a carriage which mounts an ink jet recording head and moves left and right, and which moves in the front and rear direction with respect to the ink jet recording head and has a hydrophilic property. A first wiping device using a sponge as a wiping member;
A second wiping device, which is provided at the rear of the wiping device and suctions and discharges the ink absorbed by the wiping member; Means for moving the carriage in front of the first wiping device in a state where the wiping device is retracted, and then ejecting ink from the ink jet recording head to wet the wiping member; Means for wiping the head surface by pressing the ink jet recording head, and wiping the head surface by moving the carriage while pressing the wiping member of the second wiping device against the ink jet recording head after wiping the first wiping device. Characterized in that it is provided with means for causing it to:

According to a second aspect of the present invention, there is provided a carriage comprising an ink jet recording head, which moves left and right, and a wiping member which moves in the front-rear direction with respect to the ink jet recording head and is continuously porous and water repellent. A first wiping device, a discharging device installed at a rear portion of the first wiping device, for sucking and discharging the ink absorbed by the wiping member, and a wiping member that is moved in the front-rear direction with respect to the ink jet recording head and is dried. Means for wiping the wiping member by ejecting ink from an ink jet recording head after moving the carriage in front of the first wiping apparatus in a state where the first wiping apparatus is retracted;
Means for advancing the first wiping device to press the wiping member against the ink jet recording head to wipe the head surface, and for activating the discharging device to discharge the ink absorbed by the wiping member; After the wiping and ink discharge, a means for wiping the head surface by moving the carriage while pressing the wiping member of the second wiping device against the inkjet recording head is provided.

[0018]

In the first aspect of the present invention, with the first wiping device retracted, the carriage moves forward of the first wiping device, discharges ink from the ink jet recording head, and forms a first sponge made of a hydrophilic sponge. Wet the wiping member. Here, a discharge device installed at the rear of the first wiping device sucks and discharges the ink absorbed by the first wiping member to clean the first wiping member.

Further, after the ink is ejected from the ink jet recording head to wet the first wiping member, the first wiping device is advanced and the first wiping member is pressed against the ink jet recording head by the first wiping member. Wipe the head surface. Subsequently, the carriage is moved and the second wiping device is advanced to press the second wiping member against the inkjet recording head, and the carriage is moved to wipe the head surface.

In the second invention, the carriage moves forward of the first wiping device with the first wiping device retracted, discharges ink from the ink jet recording head, and is continuously porous and water repellent. Wet the first wiping member with the pressure. Here, a discharge device installed at the rear of the first wiping device sucks and discharges the ink absorbed by the first wiping member to clean the first wiping member.

Further, after the ink is ejected from the ink jet recording head to wet the first wiping member, the first wiping device is advanced and the first wiping member is pressed against the ink jet recording head to cause the first wiping member to move. Wiping the head surface and operating the discharging device to discharge the ink absorbed by the first wiping member. Subsequently, the carriage is moved and the second wiping device is advanced to press the second wiping member against the inkjet recording head, and the carriage is moved to wipe the head surface.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram showing the configuration of the first invention. The carriage 2 on which the inkjet recording head 1 is mounted moves right and left on the guide shaft 3. A cap 4 is provided in front of the home position HP of the head 1. The cap 4 is reciprocated in the front-rear direction by a solenoid 5. At the time of non-printing, after the carriage 2 is moved to the home position HP, the cap 4 advances to the position A to cover the head 1 and prevent the ink ejection port surface from drying. During printing, the cap 4 retreats to the position B and waits.

On the right side of the cap 4, a first wiping member 6 and a second wiping member 7 are respectively supported integrally with the cap 4 by support arms. As the wiping member 6, a sponge made of a water-absorbing material is used. As the wiping member 7, a cloth or the like which has good ink absorbency and is dry is used.

The front surface of the wiping members 6, 7 is a cap 4
It almost coincides with the position of the front of. That is, when the head 1 is in the position W ₂ of the position W ₁ or second wiping member 7 of the first wiping member 6, it is advanced the cap 4 to the A position, the head 1 is a wiping member 6 or wiping member 7 Abut. When the carriage 2 is moved left and right in this state, the ink ejection port surfaces of the head 1 are wiped by the wiping members 6 and 7.

Behind the cap 4, a bellows pump 8 as a discharge device is installed, and is driven by a motor 9 to generate a negative pressure. The bellows pump 8 is connected to the cap 4 and the wiping member 6 by a tube (not shown), and sucks and discharges the ink in the cap 4 and the wiping member 6 by the generated negative pressure. The structure itself for sucking the inside of the cap 4 by the bellows pump 8 is the same as the conventional ink suction recovery device. In the drawing, reference numeral 10 denotes a platen, and reference numeral 11 denotes a recording sheet.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. The cleaning of the ink ejection port surface includes four steps. First, a step of cleaning the first wiping member is performed. In this step, the wiping member 6 is cleaned before the head 1 is cleaned. First, the solenoid 5 retreats and the cap 4 moves to B
In a state in position, it moves the head 1 to a position of W ₁ facing the wiping member 6, to eject ink from the head 1. The wiping member 6 is wet by the ejected ink.

Accordingly, the thickened ink remaining on the wiping member 6 is easily dissolved by the new ink and removed. After that, the bellows pump 8 is driven,
The residual ink adhering to the surface of the wiping member 6 and the residual ink soaking into the inside are sucked and discharged.
Along with the suction of the ink, paper dust and dust are sucked and removed, and the wiping member 6 is cleaned. These cleaning steps may be repeated a plurality of times depending on the state of dirt on the wiping member 6.

Next, a step of wetting the first wiping member is performed. The cleaned wiping member 6 is wetted by ejecting ink from the head 1 again. The amount of ink consumed in this process is at most less than one-tenth that of the amount of ink consumed when the normal ink suction / recovery device operates, and the amount of ink consumed is greatly reduced. can do.

Next, a step of wiping the head with the first wiping member is performed. In this step, the head 1 is wiped by the moistened wiping member 6.
There are several specific ways to do this. One of them is to move the carriage 2 to move the head 1 to the position of W ₁ , then advance the cap 4 to the position A, and put the moistened wiping member 6 on the ink discharge port surface 16 of the head 1. Press. When the thickened ink on the ink ejection port surface 16 is brought into close contact with the wiping member 6, it usually melts in less than one second.

[0030] Other methods, move the head 1 than the position of the W _1, to advance the cap 4 to the A position.
Then the carriage 2 is moved so that the head 1 passes the position of W _1. Whereby when the head 1 passes the position of the W _1, rubbing the surface of the wiping member 6 in which the ink discharge port surface 16 of the head 1 is wetted, the ink discharge port face 1
The thickened ink adhering on 6 is melted and removed together with paper dust, dust, etc., leaving a part. As still another method, the above-described pressing and sliding can be performed in combination. By wiping in this step, the ink ejection port surface 16 is removed.
The amount of ink remaining in the ink becomes small.

Next, a step of wiping the head with the second wiping member is performed. In this step, a very small amount of ink remaining on the ink ejection port face 16 is wiped to clean the ink ejection port face 16. Specifically, the cap 4 while the A position and moves the head 1 passes the position of W _2. As a result, the ink slightly remaining on the ink ejection orifice surface 16 in the previous step is removed from the wiping member 7 in a dry state.
Thereby, it can be almost completely wiped and removed. A series of operations in each of these steps is automatically performed under the control of a control unit (not shown).

Next, an embodiment of the second invention will be described. The second invention is different from the first invention in that a water-repellent continuous porous member is used for the first wiping member. The configuration of the other parts is common to the first invention. That is, the wiping member 6 of the embodiment of the first invention shown in FIG. 1 is replaced with a water-repellent continuous porous member to constitute the embodiment of the second invention.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. First, a step of cleaning the first wiping member is performed. However, this step is common to the first step of the embodiment of the first invention, and the description is omitted. Next, a step of wetting the first wiping member is performed. This step is also substantially the same as that of the embodiment of the first invention, except that the wiping member 6 is continuous porous and the pore diameter is R and the ink ejection port diameter is r. A continuous porous material that satisfies the following relationship with the diameter r is selected. 2r ≧ R> r

Further, since the wiping member 6 has water repellency, the ink discharged from the head 1 to the wiping member 6 hardly penetrates into the inside and easily forms an ink pool on the surface. Therefore, in order to form the ink pool in the moving direction of the carriage 2, the ink is ejected while giving a small amount of feed to the carriage 2. FIG. 4 is an explanatory diagram showing a state in which ink ejected from the ink ejection port 13 of the head 1 in this step forms an ink reservoir 14 on the wiping member 6. Reference numeral 15 in the drawing denotes a support portion of the wiping member 6.

Next, a step of wiping the head 1 with the first wiping member and sucking the ink ejection surface is performed. This step is performed by the first wiping member 6 that has been moistened.
Dissolving the thickened ink by rubbing the ink ejection port face 16 of the head 1 with the ink ejection port face 16;
A process of sucking and removing together with paper dust, dust and the like adhering to the top. In the previous step, similarly to the first embodiment, the cap 1 is advanced to the position A, and then the head 1 is moved to the H position.
It is moved in the directions of P, W ₁ and W ₂ and wiped by the wiping member 6.

In this step, the wiping member 6 is compressed as the head 1 is pressed as shown in FIG. At this time, the ink reservoir 14 formed on the surface of the wiping member 6 in the process is spread thinly and covers the entire surface of the ink ejection port surface 16.

In the subsequent steps, the ink ejection port surface 1
The ink spread over the entire surface of the nozzle 6 is removed by suction together with paper dust and dust. The suction is performed by a tube 17 penetrating and connected to the support portion 15 of the wiping member 6. The tube 17 is connected to the bellows pump 8, and the suction is started by activating the bellows pump 8 after the cap 4 advances to the position A. Although not shown, an opening is formed in the middle of the tube 17 to adjust the suction force. Here, the magnitude of the suction force is adjusted so as to be sufficient for suctioning the ink ejection port surface 16 and insufficient for sucking ink from the ink ejection port 13. In this step, it is also possible to perform suction while feeding the carriage 2 minutely, and in that case, more effective head cleaning becomes possible.

Next, a step of wiping the head with the second wiping member is performed. In this step, a very small amount of ink remaining on the ink ejection port face 16 is wiped to clean the ink ejection port face 16. Specifically, the cap 4 while the A position and moves the head 1 passes the position of W _2. As a result, the ink slightly remaining on the ink ejection orifice surface 16 in the previous step is removed from the wiping member 7 in a dry state.
Thereby, it can be almost completely wiped and removed.

According to the above embodiment, the provision of the two types of wiping members 6 and 7 which are maintained in a wet state and a substantially dry state, respectively, includes the thickened ink adhered on the ink discharge port surface 16. At first, the wiping member 6 is brought into close contact with the wiping member 6 to dissolve it to make it easier to wipe off, and then the wiping member 6 is slid and wiped / removed. Alternatively, the dirt including the melted thickened ink is sucked and removed using a pump device. As a result, wiping unevenness due to wiping is less likely to occur, and only a very small amount of ink that is easy to wipe remains on the ink ejection port surface 16. Thereafter, the ink ejection port surface 16 is wiped again by the wiping member 7 in a substantially dry state to completely remove the ink, whereby the cleanness of the ink ejection port surface 16 is uniformly increased.

As described above, in the embodiment of the present invention, the cleanness of the ink discharge port surface 16 can always be ensured while the structure is simple, and the amount of ink used for cleaning and wetting the wiping member 6 is reduced. The consumption is much smaller than when the conventional ink suction recovery device is operated, and the running cost can be reduced. In addition,
In the embodiment, the front and rear moving mechanisms of the wiping members 6 and 7 are shared by the solenoid 5, but may be independent moving mechanisms. Further, the device for sucking and removing the wiping member 6 is also used as the bellows pump 8 for sucking the cap 4, but an independent pump may be provided for each.

[0041]

As described above, according to the first aspect,
First, ink is ejected to the first wiping member,
Is cleaned, and then the head surface is wiped with the moistened first wiping member, and further the head surface is wiped with the dried second wiping member.

According to the second aspect of the present invention, first, ink is discharged to the first wiping member to clean the first wiping member, and then the head surface is wiped by the moistened first wiping member. As well as sucking and discharging ink,
Further, the head surface is wiped with the dried second wiping member. Thus, the first and second inventions can reliably clean the head surface and minimize the influence of the thickened ink. Furthermore, since the ink is used efficiently, the consumption of the ink can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an embodiment of the first invention.

FIG. 2 is a flowchart showing the operation of the embodiment of the first invention.

FIG. 3 is a flowchart showing an operation of the embodiment of the second invention.

FIG. 4 is a diagram for explaining the operation of the embodiment of the second invention.

FIG. 5 is a diagram for explaining the operation of the embodiment of the second invention.

FIG. 6 is an explanatory diagram showing a stain on an ink ejection port surface before cleaning.

FIG. 7 is an explanatory view showing a conventional cleaning device.

FIG. 8 is an enlarged view showing a main part of FIG. 7;

FIG. 9 is an enlarged view showing a main part of FIG. 7;

FIG. 10 is an explanatory diagram showing a cleaning result by a conventional apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink-jet recording head 2 Carriage 3 Guide shaft 4 Cap 5 Solenoid 6 First wiping member 7 Second wiping member 8 Bellows pump 9 Motor 10 Platen 11 Recording paper 13 Ink ejection port 14 Ink pool 15 Support section 16 Ink ejection port surface 17 tubes

Claims (2)

(57) [Claims] 1. A carriage on which an ink jet recording head is mounted and which moves left and right, a first wiping device which moves in the front-rear direction with respect to the ink jet recording head and uses a hydrophilic sponge as a wiping member, and a first wiping device. A second wiping device comprising a wiping member which is disposed at a rear portion of the wiping member and sucks and discharges the ink absorbed by the wiping member; Moving the carriage forward of the first wiping device in a state in which the wiping member is retracted, and ejecting ink from the ink jet recording head to wet the wiping member; and moving the first wiping device forward to perform ink jet recording on the wiping member. Press the head and wipe the head surface Means for wiping the head surface by moving the carriage while pressing the wiping member of the second wiping device against the ink jet recording head after wiping by the first wiping device. Cleaning device for inkjet recording head. 2. A first wiping device comprising: a carriage on which an ink jet recording head is mounted and which moves left and right; and a wiping member which moves in the front-rear direction with respect to the ink jet recording head and is continuously porous and water repellent. A second wiping device including a discharge device installed at a rear portion of the first wiping device and suctioning and discharging the ink absorbed by the wiping member; and a wiping member moving in the front-rear direction with respect to the ink jet recording head and drying. Means for moving the carriage forward of the first wiping device in a state where the first wiping device is retracted, and then ejecting ink from the ink jet recording head to wet the wiping member; and Advance and press the wiping member against the inkjet recording head Means for wiping the head surface and operating the discharge device to discharge the ink absorbed by the wiping member; and wiping the first wiping device and discharging the ink, and then performing ink jet recording on the wiping member of the second wiping device. Means for wiping the head surface by moving the carriage while pressing the head, and a cleaning device for the ink jet recording head.