JP2003266713A - 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 an unwiped part or uneven wiping, particularly a wiping member which can wipe well even in an inkjet recorder with a shifting mechanism for a recording head. <P>SOLUTION: The wiping member 11 formed of an elastic material in a nearly plate-like outline is made to satisfy relations of a thickness of T=1.3-2.0 mm, a length L of a deformed part elastically deformed at a butting time to the recording head of 6.5-10.8 mm and a hardness of H=52-70° (RHD). <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. 10 is a diagram showing a wiping operation in the wiping device 100. The wiping member denoted by reference numeral 101 is usually formed of an elastic material such as an elastomer, and the nozzle forming surface 5 of the recording head 51.
It is supported and fixed to a holder 14 which is movable relative to 2. The wiping member 101 is the holder 1
The nozzle 4 and the nozzle forming surface 52 are wiped along the moving path of the recording head 51 together with the nozzle 4.

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 into the movement path of the recording head 51, and the recording head 51 moves in a stationary state (see FIG. 10).
(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.

Factors that influence the wiping performance of the wiping member 101 are mainly the thickness, the length of the deformed portion (the portion protruding from the holder 14), and the material (hardness).

If the thickness is too thin, the wiping member 1
Since 01 strain is weakened, the force for pressing the nozzle forming surface 52 of the recording head 51 is weakened, and the wiping cannot be performed cleanly. Conversely, if the thickness is too thick, the wiping member 101
The strain becomes stronger, and the nozzle forming surface 52 of the recording head 51
The force to press is too strong, and you cannot wipe it cleanly.

Similarly, if the length of the deformed portion is too long, the wiping member 101 becomes weaker, and therefore the recording head 51
When the deforming portion is too short, the wiping member 101 becomes stiff and the pressing force of the nozzle forming surface 52 of the recording head 51 becomes too strong. You will not be able to wipe it.

Further, if the hardness H is too low (too soft), the wiping member 101 becomes weaker, so that the pressing force on the nozzle forming surface 52 of the recording head 51 becomes weaker, and the hardness H is too high (too hard). , The wiping member 101 becomes stronger and the force for pressing the nozzle forming surface 52 of the recording head 51 becomes too strong, and the wiping member 101 does not come into firm contact with the nozzle forming surface 52 at the time of wiping because the flexibility is impaired. It cannot be wiped cleanly.

In the case as described above, the ink 60 which has not been wiped remains as shown in FIG. 11 on the nozzle forming surface 52 of the recording head 51 after wiping. In FIG. 11, there is a slight step between the nozzle forming surface 52 and the support fitting 59 that surrounds the nozzle forming surface 52.
2 shows a state in which the unwiped portion and uneven wiping have occurred (for convenience of explanation, the nozzle openings are not shown). Such leftover wiping or uneven wiping is a cause of impairing the ink ejection performance from the recording head 51, and should be avoided as much as possible.

Further, in the recent ink jet recording apparatus, 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, which makes it difficult to uniquely determine the thickness of the wiping member 101, the length of the deformed portion, and the hardness in relation to the position of the recording head 51. It has become to. Therefore, in the ink jet recording apparatus provided with the paper gap adjusting mechanism, the wiping member designed on the assumption of a fixed paper gap as in the related art cannot exhibit a sufficient function.

[0018]

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.

[0019]

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. A wiping member for wiping the sheet, the thickness of the wiping member made of an elastic material having a substantially plate-like outer shape is T, and the length of a deforming portion that is elastically deformed when abutting against the recording head is L, When the hardness is H, T = 1.3 mm to 2.0 mm, L = 6.5 mm to 10.8 mm, and H = 52 ° to 70 ° (RHD).

According to this feature, the wiping performance can be improved and optimized by setting the thickness T of the wiping member, the length L of the deformed portion, and the hardness H within the above ranges. By defining the relationship between the thickness T of the wiping member, the length L of the deformed portion, and the hardness H as described above, a sufficient strain is exerted and a free elastic deformation amount is secured. The nozzle forming surface of the recording head can be wiped with an appropriate pressing force without leaving unwiping or uneven wiping.

According to a second aspect of the present invention, there is provided the wiping member according to the first aspect, wherein the free end side of the deformable portion is inclined with respect to the base end side at an angle θ toward the side facing the recording head during wiping. The angle θ is θ = 40 ° to 50 °. According to this feature, in the wiping member whose free end side is inclined to the side facing the recording head, the thickness T and the deformed portion specified in claim 1 are defined by defining the inclination angle θ in the above range. Optimal wiping performance can be obtained in relation to the length L and the hardness H.

The invention of an ejection characteristic maintaining device for an ink jet type recording apparatus according to a third aspect is characterized by including the wiping member according to the first or second aspect.
According to this feature, in the ejection characteristic maintaining device of the ink jet recording apparatus, the action and effect according to claim 1 or 2 can be obtained. The “ejection characteristic maintaining device” in the present invention means a wiping device that wipes the nozzle forming surface with the wiping member, and also includes this wiping device, a capping device that seals the nozzle forming surface, and an ink from the nozzle opening. And a suction device for forcibly sucking and discharging.

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

[0024]

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.

An ejection characteristic maintaining device 40 for maintaining the ejection characteristic of the recording head 51 is arranged at a position corresponding to the home position of the carriage 53. 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 an essential part of the ink jet type recording apparatus 50 according to this embodiment, and shows 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 fixed by a holder 14 on the base end side thereof. Here, the configuration of each part of the wiping member 11 will be described with reference to FIG. FIG. 5A shows a state of a cross section of a general flat plate-shaped wiping member 11, and FIG. 5B shows the free end side of the deformed portion with respect to the base end side when the recording head is wiped. The state of the cross section of the wiping member 11 having a shape inclined at an angle θ toward the side facing 51 is shown. By inclining the free end side of the deformed portion as shown in FIG. 5B, the nozzle forming surface 52 of the recording head 51 is formed.
It is possible to enhance the action of physically scraping off the adhered matter such as ink and dust adhered to the. The wiping member 11
The shape is not limited to that shown in FIGS. 5 (a) and 5 (b).

In FIGS. 5A and 5B, the thickness of the wiping member 11 is the thickness of the portion indicated by the symbol T. Further, the length of the deformed portion of the wiping member 11 is the length of the portion indicated by the symbol L. In order to sufficiently bring out the function of the wiping member 11, it is necessary to define the thickness T of the wiping member 11 and the length of the deformed portion L in consideration of the paper gap of the inkjet recording device 50.

The ink jet recording apparatus 5 on which the wiping member 11 is mounted is such that the thickness T of the wiping member, the length L of the deformed portion and the hardness H satisfy the above relation.
It is appropriately determined according to the paper gap setting of 0, the size of the wiping member 11, and the like. In selecting the thickness T, the length L of the deformed portion and the hardness H, a sufficient waist strength is exerted during wiping, and the nozzle forming surface 52 of the recording head 51 is slidably contacted with a sufficient pressing force. At the same time, it is possible to secure a free elastic deformation amount in the deformation part,
Even if there is a step or a protrusion on the nozzle forming surface 52, it is required that no unwiped portion or uneven wiping occurs. In the present invention, the thickness T, the length L of the deformed portion, and the hardness H satisfy the above relationship, so that the wiping member 11 contacts the nozzle forming surface 52 with a substantially constant pressing force even when the paper gap changes. Therefore, the function of the wiping member 11 is sufficiently exerted, and excellent wiping performance is obtained.

To give a concrete example, for example, in a general ink jet printer, when a plain paper is considered as the recording medium P, the thickness including the variation of the plain paper is about 0.6 mm or less. The paper gap is often set to about 1.2 mm, and at this time, as shown in FIG. 6B, the amount of interference (L ₂ ) between the recording head 51 and the wiping member 11 becomes 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. 6A, the amount of interference (L ₂ ) 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. 6C, the amount of interference (L ₂ ) 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 ₂ ) 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 of the deformed portion to the minimum interference amount of 0.6 mm, the maximum displacement amount of the recording head 51 due to the paper gap adjustment (in the above example, the paper gap is set to be extremely thick paper). (Approximately 2.8 mm when set to L), L = 6.5 mm to 10.8
It is set in the range of mm.

The thickness T is T = 1.3 mm to 2.0.
If it is selected within the range of mm, and the width is smaller than the above range, the wiping member 11 has a weak strain, and if the amount of interference is large, the force for pressing the nozzle forming surface 52 is weak and the wiping cannot be sufficiently wiped. When the thickness T is larger than the above range, the wiping member 11 becomes too strong, and when the amount of interference is small, the force for pressing the nozzle forming surface 52 becomes too strong and sufficient wiping cannot be performed.

The strength of the strain when wiping by the wiping member 11 and the magnitude of the pressing force on the nozzle forming surface 52 are
It also varies greatly depending on the hardness H of the wiping member 11. Here, the wiping member 11 is made of an elastic material such as an elastomer as described above,
For example, synthetic rubbers such as chloroprene rubber and elastic materials such as styrene elastomer [Rheostomer (trade name: RIKEN TECHNOS CORPORATION)] are preferably used. In the present invention, among these elastic materials, H = 52 ° to 70 °
(RHD) [International Rubber Harness
dness Degree)] can be selected and used with an appropriate hardness.

Further, in FIG. 5B, the free end side of the deformed portion is inclined with respect to the base end side at an angle θ toward the side facing the recording head during wiping. As shown in FIG. 5B, the inclined type wiping member 11 is superior to the flat plate type wiping member 11 [FIG. 5A] in wiping performance as described above, but has a thickness T and a deformed portion. In addition to the length L and the hardness H, the angle θ is selected so as to satisfy the above-mentioned relationship, whereby a more excellent wiping performance can be obtained. When the angle θ is larger than the above range, as shown in FIG. 7, a gap S is formed between the wiping member 102 and the side surface of the recording head 51, ink is accumulated there, and drops onto the paper surface during printing. It may end up. On the contrary, if the angle θ is less than the above, as shown in FIG. 8, the contact surface A between the tip of the wiping member 103 and the nozzle forming surface 52 of the recording head 51 becomes too large, and it may not be possible to wipe it off cleanly. .

As described above, considering the amount of displacement of the recording head 51 due to the paper gap adjustment, the length L of the deformed portion,
By defining the thickness T and the hardness H, good wiping performance can be ensured and the ejection performance can be maintained even in an ink jet recording apparatus having a paper gap adjusting mechanism. That is, the recording head 5
By advancing the wiping member 11 on the movement path of No. 1, the nozzle formation surface 52 of the recording head 51 can be wiped by utilizing the movement of the carriage 53 in the main scanning direction (see FIG. 9). Then, the wiping member 11
Is selected such that the thickness T, the length L of the deformed portion, and the hardness H satisfy the above relationship, so that an appropriate pressing force (symbol F in FIG. 9) can be secured, and thus good wiping is realized. To do.

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, the carriage 5
Although the wiping member 11 is relatively abutted by utilizing the movement of the wiping member 3 in one direction, the mechanism for performing the wiping operation is not limited to this, and the wiping member is fixed to the stationary carriage 53. Wiping may be performed by moving 11. Also, the carriage 5
A mechanism for wiping and rubbing using the reciprocating motion of 3 may be used.

[0041]

According to the present invention, the wiping performance can be improved and optimized by setting the thickness T of the wiping member, the length L of the deformed portion and the hardness H within the above ranges. By defining the relationship between the thickness T of the wiping member, the length L of the deformed portion, and the hardness H as described above, a sufficient strain is exerted and a free elastic deformation amount is secured. The nozzle forming surface of the recording head can be wiped with an appropriate pressing force without leaving unwiping or uneven wiping.

[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.

5A and 5B are drawings showing an example of a cross-sectional structure of a wiping member, wherein FIG. 5A is a flat plate-shaped wiping member, and FIG. 5B is an inclined wiping member.

FIG. 6 is a diagram illustrating a relationship between a wiping member and a paper gap adjustment.

FIG. 7 is a view for explaining a state of wiping with a conventional wiping member.

FIG. 8 is a view for explaining a state of wiping with a conventional wiping member.

FIG. 9 is a diagram illustrating a state when wiping is performed by the wiping member of the present invention.

FIG. 10 is a diagram illustrating a wiping operation performed by a wiping member.

FIG. 11 is a diagram illustrating a state of a nozzle forming surface after wiping.

[Explanation of symbols]

10 Wiping device 11 Wiping member 14 Holder 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 100 Wiping device 101-103 Wiping member

Claims (4)

[Claims] 1. A wiping member for wiping a nozzle forming surface of an ink jet recording head for recording by ejecting ink from nozzles toward a recording medium, wherein the outer shape is made of an elastic material having a substantially plate shape. Assuming that the thickness of the wiping member is T, the length of the deformed portion that elastically deforms when contacting the recording head is L, and the hardness is H, T = 1.3 mm to 2.0 mm and L = 6.5 mm A wiping member characterized by satisfying a relationship of ˜10.8 mm and H = 52 ° to 70 ° (RHD). 2. The free end side of the deformable portion according to claim 1, wherein the free end side is inclined with respect to the base end side toward the side facing the recording head at the time of wiping, and the angle θ is θ = The wiping member is characterized in that it is 40 ° to 50 °. 3. An ejection characteristic maintaining device for an ink jet recording apparatus, comprising the wiping member according to claim 1 or 2. 4. An ink jet recording apparatus comprising the ejection characteristic maintaining device according to claim 3.