JP2003211681A - Wiping member, device for maintaining discharge characteristic, and inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiping member which can wipe a nozzle formation face of a recording head by an appropriate strength without generating unwiped parts and wiping irregularities. <P>SOLUTION: The wiping member 11 is constituted of a free end side wiping part 12 which is pressed to the nozzle formation face while it is elastically deformed at a wiping time, and a base end side supporting part 13 which is formed of a material having a relatively high hardness to the wiping part 12. The wiping member 11 wipes the nozzle formation face of the inkjet recording head which records by discharging ink from nozzles towards a recording medium. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiping member used for wiping a nozzle surface of a recording head, an ejection characteristic maintaining device including the wiping member, and an ink jet recording device.

[0002]

2. Description of the Related Art An ink jet type recording apparatus includes a recording head mounted on a carriage that reciprocates in a main scanning direction, and recording medium feeding means for intermittently feeding a recording medium such as printing paper by a set amount in a sub scanning direction. It is configured such that recording is performed by ejecting ink droplets from the recording head onto the recording medium while moving the recording head in the main scanning direction.

In a mono-color ink jet recording apparatus, usually one recording head is mounted. A full-color ink jet recording apparatus is equipped with a black ink recording head that ejects black ink and a color recording head that ejects inks of respective colors such as yellow, cyan, and magenta.

In the ink jet recording apparatus, the principle of ejecting ink from the recording head is constructed as follows. That is, as is well known, the ink is pressurized at a predetermined pressure in the pressure generating chamber, and based on the pressure, the ink is ejected as an ink droplet of a controlled size from the nozzle opening on the nozzle forming surface toward the recording medium. Therefore, the ink ejection characteristics from the nozzle openings of the recording head are
It is necessary to maintain a constant value, and if the ink ejection characteristics fluctuate, the recording quality will deteriorate.

The ink ejection characteristics of the recording head fluctuate due to solidification of ink on the nozzle forming surface, clogging of the nozzle due to adhesion of dust, dust, and intrusion of bubbles from the nozzle. Therefore, in the ink jet recording apparatus, in order to maintain the ink ejection characteristics of the recording head constant, an ejection characteristic maintaining device that eliminates the above-mentioned causes of variation in the ink ejection characteristics and maintains the ejection characteristics of the recording head is provided. It is provided.

This discharge characteristic maintaining device usually firstly includes a capping device. At the time of non-recording, the nozzle forming surface is sealed by this capping device and the nozzle opening is isolated from the outside, so that ink drying is suppressed and an increase in ink viscosity is suppressed.

Further, even if the nozzle forming surface is sealed by the capping device, it is not possible to completely prevent clogging of the nozzle opening, mixing of bubbles into the ink flow path, and the like. Therefore, secondly, the ejection characteristic maintaining device is provided with a suction device capable of forcibly sucking and discharging ink from the nozzle opening in order to remove clogging of the nozzle opening and mixed bubbles. This suction device applies a negative pressure to the nozzle opening in a state where the nozzle forming surface is sealed by the capping device to forcibly suck and discharge the ink from the nozzle opening to remove the clogging and mixed bubbles. Remove. The forced suction and discharge process of ink by this suction device is usually
It is executed when the recording operation is restarted after the recording apparatus is stopped for a long time, or when the user recognizes that the quality of the recorded image is deteriorated and operates the dedicated switch on the operation panel.

When the ink is forcibly sucked and discharged by the suction device as described above, the ink may be scattered and adhered to the nozzle forming surface of the recording head, and the meniscus of the ink in each nozzle opening may be disturbed. Also,
Foreign substances are likely to adhere to the nozzle formation surface of the recording head over time. Therefore, thirdly, the ejection characteristic maintaining device is provided with a wiping device for wiping the nozzle forming surface as needed. This wiping device has a wiping member made of an elastic material such as rubber, and the base end side of the wiping member is clamped and supported by a holder. Then, the edge portion on the front end side of the wiping member or the periphery thereof is elastically pressed against the nozzle forming surface and relatively moved to clean the nozzle forming surface.

The cleaning operation by the wiping member is
It is said to be a "wiping operation". This “wiping operation” plays an important role of wiping off ink and dust adhering to the nozzle forming surface and evenly adjusting, ie, stabilizing, the meniscus of ink in each nozzle opening. Therefore, the pressing force that elastically presses the edge portion of the wiping member against the nozzle forming surface is soft and has an appropriate strength to the extent that the ink and other deposits can be removed and the meniscus can be reliably stabilized. There is a technical requirement that it must be set to.

FIG. 8 is a diagram showing a wiping operation in the conventional wiping device 100. The wiping member denoted by reference numeral 101 is usually formed of a single elastic material such as an elastomer, and is supported and fixed to the holder 14 which is movable relative to the nozzle forming surface 52 of the recording head 51. . Then, the wiping member 101
Is configured to be able to move forward and backward along the movement path of the recording head 51 together with the holder 14, and wipe the nozzle forming surface 52.

More specifically, the wiping member 101
Are arranged with a sufficient amount of interference for sliding contact with the nozzle forming surface 52 of the recording head 51.
The wiping member 101 advances on the movement path of the recording head 51, and the recording head 51 moves in a stationary state (see FIG. 8).
(In the direction of the arrow), the wiping member 101 made of an elastic material comes into contact with the nozzle forming surface 52 while deforming, and wipes the nozzle forming surface 52 to mechanically remove the adhered ink and the like. Wipe off. By this action,
It is possible to prevent the ink or the like adhering to the nozzle forming surface 52 of the recording head 51 from being solidified or scattered on the recording medium during recording, and to stabilize the meniscus.

However, when the wiping member 101 is formed of an elastic material having a relatively high hardness (hardness), if there is a step or a protrusion on the nozzle forming surface 52 or its periphery,
A gap is formed between the nozzle forming surface 52 and the wiping member 101, and the ink or the like cannot be wiped off sufficiently. Conversely, when the wiping member 101 is made of an elastic material having a low hardness (soft), the stiffness of the wiping member 101 becomes weak, and a sufficient pressing force cannot be secured, so that there is a problem that the wiping cannot be sufficiently wiped. Therefore, as a result, the unwiped ink 60 remains as shown in FIG. 9 on the nozzle forming surface 52 of the recording head 51 after wiping. FIG. 9 shows a state in which the ink 60 is left unwiped or unevenly wiped as a result of the presence of a slight step between the nozzle forming surface 52 and the support fitting 59 surrounding the nozzle forming surface 52 (for convenience of explanation). , The nozzle openings are not shown). Unwiping and uneven wiping are factors that impair the ink ejection performance from the recording head 51, and should be avoided as much as possible.

Further, in recent ink jet type recording apparatuses, various recording media (for example, plain paper, thick paper, C
A device having a mechanism (paper gap adjusting mechanism) for displacing the nozzle forming surface 52 of the recording head 51 so as to correspond to a D-ROM or the like has been put into practical use. In the ink jet type recording apparatus provided with this paper gap adjusting mechanism, when the recording head 51 is displaced, the wiping member 1
01 and the amount of interference between the recording head 51 also change, it is becoming difficult to uniquely determine the optimum length and rigidity of the wiping member 101 in relation to the position of the recording head 51. For example, when a material having low hardness is used for the wiping member 101 and the rigidity is set to be small, if the amount of interference between the wiping member 101 and the recording head 51 is appropriate, the wiping member 101 can be wiped with sufficient pressing force, but the amount of interference is too large. If the amount of interference is too small, the pressing force becomes weak, and in any case, there is a problem that wiping becomes insufficient.

On the other hand, Japanese Unexamined Patent Publication No. 10-235883 proposes a wiping device in which the base end side is formed thicker than the free end side in order to facilitate the support of the wiping member. In the 235894 publication,
In order to eliminate the color mixture of ink due to the wiping operation, a wiping member has been proposed in which an elastic body and an ink absorbing member made of a porous body shorter than the elastic body are arranged. No consideration has been given to the problem of unwiping of the adhered ink or uneven wiping.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to provide a wiping member capable of wiping a nozzle forming surface of a recording head with moderate strength without causing unwiping and uneven wiping. In particular, it is an object of the present invention to provide a wiping member capable of excellent wiping even in an ink jet type recording apparatus provided with a recording head displacement mechanism.

[0016]

In order to solve the above problems, the invention of a wiping member according to claim 1 is a nozzle forming surface of an ink jet recording head for recording by ejecting ink from a nozzle toward a recording medium. Is a wiping member for wiping, a wiping portion on the free end side that is pressed against the nozzle forming surface at the time of wiping, and a supporting portion on the base end side, the wiping portion and the supporting portion, respectively, the hardness. It is characterized in that it is formed of an elastic material of different material. According to this feature, since the wiping portion and the support portion are formed of elastic materials having different hardnesses, the degree of freedom in design is significantly widened as compared with the conventional wiping member formed of an elastic material having a single hardness. The wiping performance can be improved. That is, the elastic deformation amount and the pressing force at the time of wiping can be freely set according to the shape around the nozzle forming surface of the recording head (whether there is a step or the like) and the displacement of the recording head by the paper gap adjusting mechanism. Compared to a single material wiping member, it has a wider range in which good wiping performance can be exhibited.

Further, the invention of a wiping member according to a second aspect is characterized in that, in the first aspect, the wiping portion is formed of an elastic material having a relatively low hardness with respect to the supporting portion. . According to this feature, the wiping portion pressed against the nozzle forming surface is formed of a material having a relatively low hardness with respect to the supporting portion, so that the nozzle forming surface of the recording head can be left unwiped or wiped unevenly with an appropriate pressing force. It can be wiped without causing. That is, at the time of wiping, the supporting portion exerts sufficient waist strength, the nozzle forming surface of the recording head can be slidably contacted with sufficient pressing force, and at the same time, the wiping portion made of a material having relatively low hardness is Since it is highly flexible and a free amount of elastic deformation is secured, even if there are steps or protrusions on the nozzle formation surface, almost no unwiping or uneven wiping occurs.

According to a third aspect of the present invention, there is provided a wiping member according to the first or second aspect, wherein the support portion has a paper gap adjusting mechanism to maximize an amount of interference between the wiping member and the recording head. It is characterized in that it is formed in such a length that it does not come into contact with the nozzle forming surface even when it is wiped. According to this feature, even if the amount of interference with the recording head is maximized, the supporting portion is formed with a length that does not contact the nozzle forming surface. The nozzle forming surface can be wiped with various elastic forces and flexibility.

Further, the invention of a discharge characteristic maintaining device of an ink jet type recording apparatus according to a fourth aspect is characterized by including the wiping member according to any one of the first to third aspects. According to this feature, in the ejection characteristic maintaining device of the ink jet recording apparatus, the action and effect according to any one of claims 1 to 3 can be obtained. In addition, in the "ejection characteristic maintaining device" of the present invention, in addition to the wiping device that wipes the nozzle forming surface with the wiping member, this wiping device, a capping device that seals the nozzle forming surface, and ink from the nozzle openings. A unitized device that includes a suction device for forcibly sucking and discharging is also included.

The invention of an ink jet recording apparatus according to a fifth aspect is characterized by including the ejection characteristic maintaining device according to the fourth aspect. According to this feature, in the ink jet recording apparatus, the same operational effect as that of the fourth aspect can be obtained.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an outline of an inkjet printer 50 according to an embodiment of the present invention.
Here, the state where the main body cover is removed is shown to clarify the internal structure. The carriage 53 reciprocates in the main scanning direction along the carriage guide shaft 55 by the timing belt 57 connected to the drive motor 56, and ejects ink from the recording head 51 onto the recording medium P to form an image. A plurality of ink cartridges 54 of different colors such as black, cyan, magenta, and yellow can be mounted on the carriage 53.

At the position corresponding to the home position of the carriage 53, an ejection characteristic maintaining device 40 for maintaining the ejection characteristic of the recording head 51 is arranged. The discharge characteristic maintaining device 40 includes a wiping device 10, a capping device 20, and a suction device 30. Then, when the carriage 53 is in the home position, the discharge characteristic maintaining device 40
A capping operation, a suction operation, and a wiping operation that maintain the ejection characteristics of the recording head 51 are performed.

FIG. 2 is a plan view of a main part of the ink jet type recording apparatus 50 according to the present embodiment, showing an outline of the ejection characteristic maintaining apparatus 40. Further, FIG. 3 is a side view of the main part. In this embodiment, the capping device 20
The cap member 21 is provided with a known displacement mechanism capable of contacting with or separating from the nozzle forming surface 52 of the recording head 51. As shown in FIG. 3, with the cap member 21 sealing the nozzle formation surface of the recording head 51, the ink is forcibly discharged by the suction device 30 (see FIG. 1) through the suction hole 31, The recording head 51 is cleaned. A carriage 53 is provided on the side of the printing area adjacent to the cap member 21 of the capping device 20.
The wiping device 10 for wiping the nozzle forming surface 52 of the recording head 51 with the movement of the recording head 51 is provided.

Wiping member 11 of wiping device 10
Is equipped with a mechanism capable of moving horizontally in a direction orthogonal to the main scanning direction in which the carriage 53 reciprocates (a direction orthogonal to the paper surface of FIG. 3), and advances to a predetermined position in the movement path of the recording head 51, or It is configured so that it can be evacuated. Here, the advancing / retreating operation of the wiping member 11 is performed by a known mechanism, and the driving force thereof is a driving force of a paper feed motor (not shown) for conveying the recording medium.

FIG. 4 is a perspective view showing a main part of the wiping device 10 having the wiping member 11. The wiping member 11 is formed of a material having a predetermined length and a low hardness from the free end side and easily wiped elastically, and a wiping member 12 having a predetermined length and a high hardness from the base end side. The support portion 13 is less likely to be elastically deformed than the above.
As described above, the wiping portion 12 partially (mainly at the free end) contacts the nozzle forming surface 52 of the recording head 51. The support portion 13 is fixed by a holder 14.

FIG. 5 shows a preferred example of the wiping member 11. The wiping member 11 has a substantially rectangular plate shape in cross section as shown in FIG. 5A, or has a cross-sectional width that becomes narrower toward the free end side of the wiping portion 12 as shown in FIG. 5B. It may be a sharp shape with a thin wall. The length of the wiping portion 12 of the wiping member 11 (L ₁₎ and the support portion length of (L ₂₎ can be appropriately set as described below. Further, as shown in FIG. 5B, when the wiping operation is performed, the free end is curved in the shape of an arc toward the side facing the advancing recording head 51, so that it adheres to the nozzle forming surface 52 of the recording head 51. It is possible to enhance the action of physically scraping off the adhered substances such as ink and dust. The shape of the wiping member 11 is not limited to the shapes shown in FIGS.

The wiping member 11 is formed of an elastic material such as an elastomer as described above. For example, synthetic rubber such as chloroprene rubber or styrene elastomer [Rheostomer (trade name: RIKEN TECHNOS CORPORATION)].
An elastic material such as the above is preferably used, and one having an appropriate hardness can be selected and used from these elastic materials.

The wiping portion 12 and the supporting portion 13 can be adjusted to have an appropriate hardness by selecting the materials to be used. In the present invention, the hardness of the wiping portion 12 is relatively lower than that of the supporting portion 13. By changing the hardness of the wiping portion 12 and the support portion 13 in this way, the support portion 13 exerts a sufficient stiffness at the time of wiping, and the nozzle forming surface 52 of the recording head 51 is brought into sliding contact with a sufficient pressing force. At the same time, the wiping portion 12 made of a material having relatively low hardness
Is highly flexible and secures a free elastic deformation amount. Therefore, even if there is a step or a protrusion on the nozzle forming surface 52, no unwiping or uneven wiping occurs.

The wiping portion 12 and the support portion 13 may be made of the same material having different hardnesses or different materials (for example,
Styrene-based elastomer may be used for the wiping portion 12, and chloroprene rubber or the like may be used for the supporting portion 13.

How to set the hardness of the wiping part 12 and the supporting part 13 is appropriately determined according to the paper gap setting of the ink jet type recording apparatus 50 on which the wiping member 11 is mounted and the size of the wiping member 11. Preferably. For example, as a preferable example in the case of a general inkjet printer, it is possible to set the difference in hardness between the wiping portion 12 and the supporting portion 13 to about 10 to 30 RHD. More specifically, for example, the wiping unit 12
When the hardness is 40 to 50 RHD, the hardness of the supporting portion 13 may be about 60 to 70 RHD.

As described above, the wiping member 11 in which the hardness of the wiping part 12 and the support part 13 is changed can be manufactured by, for example, a two-color molding method. As a manufacturing example of a typical two-color molding process, using a known two-color molding machine,
A method of forming the support portion 13 with an arbitrary elastic material using a cylinder and then forming the wiping portion 12 with a second cylinder can be used. When the wiping member 11 is molded by a two-color molding method or the like, a boundary portion 15 between the wiping portion 12 and the supporting portion 13 is formed.
(Joint surface of materials having different hardness) is shown in FIGS.
It is preferable that the convex portion and the concave portion are engaged with each other as illustrated in FIG. This is because the wiping member 11 that repeats elastic deformation is required to have sufficient durability.

The length and ratio (see FIG. 5) of the wiping portion 12 and the supporting portion 13 of the wiping member 11 are set to a certain extent by setting the paper gap of the ink jet type recording apparatus 50 in which the wiping member 11 is mounted. Alternatively, it can be determined according to the size of the wiping member 11 and the like, but preferable examples are as follows. First, the support portion 13 may be formed with a length such that the support portion 13 does not contact the nozzle forming surface even when the amount of interference between the recording head 51 and the wiping member 11 is maximized by the paper gap adjusting mechanism. Can be mentioned. This is because if the supporting portion 13 having a relatively high hardness directly contacts the nozzle forming surface 52 of the recording head 51, wiping unevenness or the like is likely to occur.

Further, the supporting portion 13 has the recording head 51 and the wiping member 11 by a paper gap adjusting mechanism.
The length is preferably such that a sufficient pressing force to the nozzle forming surface 52 can be maintained even if the amount of interference with In this case, as the length of the support portion 13, the length (L ₄ ) of the portion substantially protruding from the holder 14 becomes important.

The wiping portion 12 and the supporting portion of the wiping member 11
When describing the length of 13 along with a concrete example, for example,
Of a recording medium P in a typical inkjet printer
When considering plain paper,
The paper gap is
It is often set to about 1.2 mm.
As shown in FIG. 7B, the recording head 51 and the wiping unit
Interference with material 11 (L _Three) Is the largest.

The recording medium P is, for example, a CD-R.
When considering an extremely thick paper such as a tray, if the thickness including the variation of the extremely thick paper is set to about 1.6 mm to 2.5 mm, the recording head 51 has a position (for example, 2.8 mm) as compared with the position of the plain paper.
It becomes the most displaced state (with a displacement amount of about mm). As a result, as shown in FIG. 7A, the amount of interference (L ₃ ) between the recording head 51 and the wiping member 11 is minimized.

Further, when considering thick paper as a recording medium, for example, the thickness including variation of thick paper is about 0.7 mm.
When it is set to ˜1.5 mm, the nozzle forming surface 52 of the recording head 51 is adjusted to an intermediate position between plain paper and extremely thick paper (for example, a displacement amount of about 1.5 mm compared with plain paper). As a result, as shown in FIG. 7C, the amount of interference (L ₃ ) between the recording head 51 and the wiping member 11 is smaller than that of plain paper and larger than that of extremely thick paper.

In order to perform sufficient wiping, the recording head 5
The amount of interference (L ₃ ) between 1 and the wiping member 11 must be at least 0.6 mm, and is 0.6 m.
Since it is preferable to set the length (L ₁ ) of the wiping unit 12 to the minimum interference amount of 0.6 mm, the maximum displacement amount of the recording head 51 by the paper gap adjustment (in the above example, the paper gap is about m to 3.3 mm). Is about 2.8 mm when it is set for extra thick paper, and it is preferable to set the length to be equal to or longer than the total length. Further, the support portion 13 may be set to have a length such that the wiping portion 12 can be sufficiently pressed against the nozzle forming surface of the recording head 51 regardless of the stage where the paper gap is adjusted according to its hardness. .

As described above, the ink jet recording apparatus having the paper gap adjusting mechanism is provided by defining the lengths of the wiping portion 12 and the supporting portion 13 in consideration of the displacement amount of the recording head 51 due to the paper gap adjustment. Also in this case, good wiping is ensured, and it becomes possible to maintain the ejection performance. That is, by advancing the wiping member 11 on the movement path of the recording head 51,
The nozzle forming surface 52 of the recording head 51 can be wiped by using the movement of the carriage 53 in the main scanning direction (see FIG. 8). In the wiping member 11, the wiping portion 12 having a relatively low hardness and a large amount of elastic deformation wipes the nozzle forming surface 52 with flexibility, while an appropriate pressing force can be secured by the support portion 13, so that a good wiping is achieved. Will be realized.

Although the present invention has been described above with respect to various embodiments, the present invention is not limited to the above embodiments, and other embodiments are also possible within the scope of the invention described in the claims. Applied.

For example, in the above embodiment, one member such as a plate-like member is used as the wiping member 11, but the wiping member 11 is not limited to this. For example, a structure in which two plate-like elastic members are bonded together is also applicable. The present invention can be applied by changing the hardness of the wiping part and the support part.

Further, in the above embodiment, the carriage 53
Using the movement in one direction, the wiping member 1 relatively
However, the mechanism for performing the wiping operation is not limited to this, and wiping may be performed by moving the wiping member 11 with respect to the stationary carriage 53. Also, the carriage 53
A mechanism for performing wiping and rubbing using the reciprocating motion of

[0042]

According to the present invention, the nozzle forming surface of the recording head is appropriately provided by providing the supporting portion formed of a material having a relatively high hardness with respect to the wiping portion pressed against the nozzle forming surface. With such a pressing force, wiping can be performed without causing unwiping and uneven wiping. That is, in the wiping member of the present invention, the supporting portion is made of a material having a relatively high hardness and the wiping portion is made of a material having a relatively low hardness. The strength of the waist is exerted, and the nozzle forming surface of the recording head can be brought into sliding contact with sufficient pressing force, and at the same time, the wiping part made of a material with relatively low hardness is rich in flexibility and free of elastic deformation. Therefore, even if there is a step or a protrusion on the nozzle formation surface, almost no unwiping or uneven wiping occurs.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of an inkjet recording apparatus.

FIG. 2 is a plan view of an essential part of FIG. 1, and is a drawing for explaining an ejection characteristic maintaining device.

FIG. 3 is a side view of a main part of FIG. 1, and is a drawing for explaining an ejection characteristic maintaining device.

FIG. 4 is a perspective view of a wiping member.

FIG. 5 is a cross-sectional view showing an aspect of a wiping member.

FIG. 6 is a view showing an example of a sectional structure of a wiping member.

FIG. 7 is a diagram illustrating a relationship between a wiping member and a paper gap adjustment.

FIG. 8 is a diagram illustrating a wiping operation by a wiping member.

FIG. 9 is a diagram illustrating a state of a nozzle forming surface after wiping.

[Explanation of symbols]

10 Wiping device 11 Wiping member 12 Wiping section 13 Support 14 Holder 15 border 20 capping device 21 Cap member 30 suction device 31 suction hole 40 Discharge characteristics maintenance device 50 inkjet recording device 51 recording head 52 Nozzle formation surface 53 carriage 54 ink cartridges 55 Carriage guide shaft 56 drive motor 57 Timing Belt 58 Platen 59 Support bracket 60 ink

Claims (5)

[Claims] 1. A wiping member for wiping a nozzle forming surface of an ink jet recording head for performing recording by ejecting ink from nozzles toward a recording medium, the wiping member on a free end side being pressed against the nozzle forming surface during wiping. A wiping member, characterized in that the wiping part and the supporting part are made of elastic materials having different hardnesses. 2. The wiping member according to claim 1, wherein the wiping portion is formed of an elastic material having a relatively low hardness with respect to the supporting portion. 3. The nozzle supporting surface according to claim 1, wherein the support portion contacts the nozzle forming surface during wiping even when the amount of interference between the wiping member and the recording head is maximized by the paper gap adjusting mechanism. A wiping member, characterized in that it is formed so as not to come into contact with it. 4. An ejection characteristic maintaining device for an ink jet recording apparatus, comprising the wiping member according to claim 1. Description: 5. An ink jet recording apparatus comprising the ejection characteristic maintaining device according to claim 4.