JP3906794B2 - Liquid ejector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid ejecting apparatus that ejects liquid using a liquid ejecting head, such as a printer, a display manufacturing apparatus, an electrode forming apparatus, or a biochip manufacturing apparatus, and in particular, wipes a nozzle forming surface of the liquid ejecting head. The present invention relates to a liquid ejecting apparatus including a wiping mechanism having a wiper blade.
[0002]
[Prior art]
Examples of a liquid ejecting apparatus having a liquid ejecting head capable of ejecting liquid in the form of droplets include an image recording apparatus that ejects ink droplets to record an image on recording paper, and ejects a liquid electrode material onto a substrate. An electrode forming apparatus for forming an electrode, a biochip manufacturing apparatus for manufacturing a biochip by discharging a biological sample, or a micropipette for discharging a predetermined amount of a sample to a container has been proposed. In this type of liquid ejecting apparatus, the liquid to be ejected is stored in a storage container, and this liquid is supplied to the liquid ejecting head to be ejected.
[0003]
The above-described liquid ejecting head discharges the liquid pressurized in the pressure generating chamber as a droplet from the nozzle opening toward the object, but the nozzle opening forms a droplet when the discharged droplet hits the object. In some cases, the surface adheres to the surface (hereinafter referred to as the nozzle formation surface) and becomes dirty.
In addition, when discharging from the nozzle opening, in addition to the droplets that land on the object, smaller droplets (satellite) separated from the droplets may be generated. This satellite does not reach the object but drifts in the air and may adhere to the nozzle forming surface.
[0004]
Furthermore, in order to eliminate clogging of the nozzle opening, the nozzle forming surface is sealed with a cap member that seals the nozzle forming surface, and a negative pressure is applied from the suction pump to forcibly suck and discharge liquid from the nozzle opening. When processing is performed, droplets may remain in the vicinity of the nozzle opening.
[0005]
As described above, when the nozzle forming surface of the liquid jet head, particularly around the nozzle opening, becomes dirty, the droplet discharge direction deviates from the normal direction, or the nozzle is blocked and cannot be discharged. There is a risk of affecting.
[0006]
In order to solve this problem, some liquid ejecting apparatuses of this type include a wiping mechanism that wipes off dirt adhering to the nozzle formation surface. The wiping mechanism includes a plate-like (strip-like) wiper blade formed of an elastic material such as rubber or elastomer, and is disposed on the home position side which is a standby area of the liquid ejecting head in the liquid ejecting apparatus. ing.
[0007]
In the normal state, this wiping mechanism is located at a retracted position where it does not contact the liquid ejecting head. However, when the liquid ejecting head moves from the home position to the drive region side, the upper part of the wiper blade is the nozzle of the liquid ejecting head. It moves (rises) to a wiping position where it can contact the forming surface. When the wiper blade comes into contact with the liquid ejecting head, the entire blade bends in a bow shape, and the nozzle forming surface is wiped by moving the liquid ejecting head with the tip of the blade being in contact with the nozzle forming surface. Dirt adhered to the nozzle forming surface is removed.
[0008]
By the way, since the nozzle forming surface of the liquid jet head is not completely flat and has a lot of irregularities, it is preferable to use a soft material (low elastic modulus) as the material of the wiper blade. In other words, if a soft (easy to deform) wiper blade is used, the wiper blade deforms following the uneven shape of the nozzle forming surface during wiping, so that the nozzle forming surface can be wiped evenly.
[0009]
However, the wiper blade made of a soft material has a drawback that a repulsive force when contacting the nozzle forming surface is small, and a contact pressure necessary for reliably wiping off dirt cannot be obtained.
On the other hand, if the wiper blade is made of a harder material (having a higher elastic modulus) in order to obtain sufficient contact pressure on the nozzle formation surface, the wiper blade will be deformed following the irregular shape of the nozzle formation surface. Therefore, the dirt on the concave portion of the nozzle forming surface cannot be wiped off, resulting in uneven wiping.
[0010]
In order to solve this problem, it is conceivable that the wiper blade is made of, for example, two kinds of materials, a material having a low elastic modulus and a material having a high elastic modulus (for example, see Patent Document 1).
[0011]
That is, by using a soft material for the part that contacts the nozzle forming surface and using a hard material for the other parts, the uneven shape of the nozzle forming surface is obtained while obtaining the contact pressure necessary to remove dirt. It is possible to make it easy to remove dirt on the nozzle forming surface.
[0012]
[Patent Document 1]
JP 2001-334676 A (5th page, FIG. 5 etc.)
[0013]
[Problems to be solved by the invention]
However, in order to create a wiper blade with a plurality of types of materials, two-color molding and an assembling process are required, and there is a problem in that it is disadvantageous in terms of cost and manufacturing efficiency.
[0014]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a liquid ejecting apparatus capable of more efficiently removing dirt adhered to the nozzle forming surface of the liquid ejecting head at a low cost. It is to provide.
[0015]
[Means for Solving the Problems]
The present invention has been proposed in order to achieve the above-described object, and has a liquid ejecting head that ejects liquid droplets from a nozzle, and has elasticity, and is formed in contact with the nozzle forming surface of the liquid ejecting head. A wiper blade for wiping the surface, a wiper holding member for holding the wiper blade, and a wiper moving mechanism for moving the wiper holding member to a position where the upper portion of the wiper blade can contact the nozzle forming surface. In the liquid ejecting apparatus, a blade support member is erected side by side with the wiper blade on the wiper holding member, and the blade support member is located in front of the wiper blade in the passing direction of the liquid ejecting head during wiping. And the height is set lower than that of the wiper blade at the time of wiping, and the surface facing the wiper blade is curved in an arc shape. It has been curved surface, characterized in that the wiper blade during wiping and adapted to support in a state of leaning to the curved surface.
[0016]
According to the above configuration, even when a wiper blade made of a relatively soft material is used, since the blade support member supports the wiper blade at the time of wiping, a sufficient contact pressure with respect to the nozzle forming surface can be obtained, and Since the contact portion with the nozzle forming surface contacts the nozzle forming surface while deforming following the uneven shape of the nozzle forming surface, the nozzle forming surface can be wiped more uniformly.
[0017]
In addition, since the wiper blade is supported by the entire curved surface of the blade support member, the posture at the time of wiping is stable, and the wiping can be performed while keeping the contact pressure constant over the entire surface of the nozzle forming surface. It is possible to more efficiently remove the dirt.
[0018]
The said structure WHEREIN: It is preferable that the said blade support member is formed with the raw material with a larger elastic modulus than the said wiper blade.
[0019]
In the above configuration, it is more preferable that the blade support member is made of synthetic resin or metal.
[0020]
And in the said structure, a manufacturing process can be simplified and it is advantageous in terms of cost by integrally molding the said blade support member with the said wiper holding member.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, an ink jet printer (hereinafter simply referred to as a printer), which is a kind of liquid ejecting apparatus, is taken as an example. This printer records characters and images by landing liquid ink ejected from nozzle openings on the surface of recording paper (a type of print recording medium), and is also a type of image recording apparatus.
[0022]
The printer 1 shown in FIG. 1 includes a carriage 4 having a cartridge mounting portion 2 and attached with a recording head 3 (a kind of the liquid ejecting head of the present invention).
Although not shown, the recording head 3 includes a pressure generating element such as a piezoelectric vibrator, a flow path unit in which a series of flow paths from a common ink chamber to a nozzle opening through a pressure chamber are formed, and the like. By driving the generating element, pressure fluctuation is generated in the pressure chamber, and ink in the pressure chamber is ejected from the nozzle opening as ink droplets (droplets in the present invention).
[0023]
The recording head 3 is attached to the carriage 4 downward so that the nozzle plate (that is, the nozzle forming surface) in which the nozzle openings are formed faces the recording paper 7. As the pressure generating element, a so-called longitudinal vibration mode piezoelectric vibrator, a so-called flexural vibration mode piezoelectric vibrator, or a heat generating element that generates bubbles by generating heat to generate pressure fluctuation in the pressure chamber is used. be able to.
[0024]
A black ink cartridge 5A and a color ink cartridge 5B for supplying ink to the recording head 3 are detachably mounted on the cartridge mounting portion 2 of the carriage 4.
The carriage 4 is attached to the guide rod 6 so as to be movable in the width direction (main scanning direction) of the recording paper 7. The carriage 4 is connected to a timing belt 10 that is stretched between a driving pulley 8 and an idle pulley 9. The drive pulley 8 is joined to the rotating shaft of the pulse motor 11. Accordingly, the carriage 4 is moved in the width direction of the recording paper 7 by the operation of the pulse motor 11.
[0025]
A paper feed roller 12 is disposed below the guide rod 6 in parallel with the guide rod 6. The paper feed roller 12 is rotated by the driving force from the paper feed motor 13 when the recording paper 7 is conveyed in the sub-scanning direction.
[0026]
A home position is set in an end area (right side in FIG. 1) that is within the moving range of the carriage 4 and outside the recording area (driving area). On the home position side, a wiping mechanism 14 for cleaning the nozzle forming surface of the recording head 3 and a capping mechanism 15 capable of capping (sealing) the nozzle forming surface are arranged side by side.
[0027]
Next, the capping mechanism 15 will be described. As shown in FIGS. 2 and 4, the capping mechanism 15 has a concave negative pressure air portion 18 and has a cap member 19 capable of sealing the nozzle forming surface, and the cap member 19 mounted on the upper side. The slide mechanism 20 is movable in the direction.
[0028]
The cap member 19 is a substantially rectangular box as viewed from above, more specifically, a tray-like member with an open top surface, and the whole is made of an elastic material such as an elastomer. On the bottom surface of the cap member 19, a drainage port 22 that is communicated with a drainage tube described later is formed. Further, a liquid absorbent sheet 23 having liquid absorbency and moisture retention is disposed inside the cap member 19. The liquid absorbing sheet 23 is made of felt, for example.
[0029]
As shown in FIG. 3, the slide mechanism 20 includes a slider 24 having a cap member 19 disposed on the upper surface, a holder member 26 having a long hole 25 serving as a cam surface on the side surface, and the slider 24 and the holder. A frame 27 to which the member 26 is attached is schematically configured. An engagement shaft 30 projects from the side surface of the frame 27, and one end of an arm member 31 is rotatably attached to the engagement shaft 30. The other end of the arm member 31 is pivotally supported by the slider 24. The support shaft 32 protruding from the side surface of the slider 24 is inserted into the elongated hole 25 of the holder member 26 in a movable state. The long hole 25 has a low portion formed on the tip side close to the recording region side (platen 33 side), and a horizontal high portion formed on the rear end portion far from the recording region. Further, an inclined portion is formed between these low and high portions. The long hole 25 forms a cam surface that is low on the recording area side and rises as the distance from the recording area increases.
[0030]
The slider 24 is biased diagonally downward by a spring 34 (a tension spring) having one end attached to the support shaft 32 and the other end attached to the frame 27. For this reason, in a state where the carriage 4 is positioned outside the home position, the slider 24 is positioned on the recording area side (the retracted state shown in FIG. 3A). In this retracted state, since the support shaft 32 is located at the end of the long hole 25 on the recording area side, the cap member 19 provided on the slider 24 is at a retracted position lower than the height of the nozzle forming surface of the recording head 3. Positioned.
[0031]
On the other hand, when the slider 24 moves in a direction away from the recording area and is positioned at the opposite end of the long hole 25 (referred to as a remote end for convenience), specifically, it is provided integrally with the slider 24. When the carriage 4 is positioned at the home position in a state where the contact portion 36 of the carriage 4 is in contact with the contact protrusion 35, the slider 24 moves against the pulling force of the spring 34, and the support shaft 32 side. This part rises along the long hole 25. Further, the cap member 19 is lifted by the rotation of the arm member 31. Thereby, the cap member 19 moves obliquely upward to seal the nozzle forming surface (capping state shown in FIG. 3B). In this capping state, the nozzle opening formed in the nozzle forming surface faces the negative pressure air portion 18 of the cap member 19, and the upper end edge of the cap member 19 and the nozzle forming surface are in close contact with each other.
And in this state, since the liquid absorption sheet 23 exists in the negative pressure air part 18, the inside of this negative pressure air part 18 is maintained in a highly humid state. As a result, evaporation of the ink solvent from the nozzle openings of the recording head 3 is suppressed, and an increase in ink viscosity is suppressed.
[0032]
Here, as shown in FIG. 4, a flexible drainage tube 39 that connects the negative pressure air portion 18 and the drainage tank 38 is connected to the drainage port of the cap member 19. Further, a pump unit 40 is disposed in the middle of the drainage tube 39, and a part of the drainage tube 39 is supported by the pump unit 40 as shown in FIG.
[0033]
The pump unit 40 is configured by a so-called tube pump that sends air and ink in the drainage tube 39 to the downstream side by crushing and squashing the drainage tube 39 with a roller 41. When the pump unit 40 is operated in the above-mentioned capping state, the negative pressure air 18 is negatively pressured, so that the ink in the recording head 3 can be discharged through the nozzle openings. Thereby, the ink thickened near the nozzle opening can be forcibly discharged, and the ejection of ink droplets can be maintained well.
[0034]
When the carriage 4 moves from the home position to the recording area side, the slider 24 moves to the recording area side by the pulling force of the spring 34. At this time, the portion of the slider 24 on the support shaft 32 side is lowered along the long hole 25, and the portion on the recording area side is also lowered by the return rotation of the arm member 31. As a result, the cap member 19 moves obliquely downward toward the recording area side and is positioned below the nozzle formation surface.
[0035]
The wiping mechanism 14 is provided between the slider 24 and the recording area (platen 33). The wiping mechanism 14 includes a wiper blade 44, a wiper holder (wiper holding member) 45, and a wiper moving mechanism 46. A blade support member 47 is erected on the wiper holder 45 in a position adjacent to the wiper blade 44.
The wiper holder 45 is configured to move in the horizontal direction by the wiper moving mechanism 46 so as to advance and retreat to a wiping position that overlaps the moving path of the recording head 3 and a retracted position that deviates from the moving path.
[0036]
The wiper blade 44 is a plate-like member formed of an elastic material such as rubber or elastomer, for example, and a base end portion (lower end portion) is held by the wiper holder 45. The wiper blade 44 in the present embodiment is formed of, for example, a relatively soft (low elastic modulus) elastomer having a hardness of 30 to 40 degrees. The material of the wiper blade 44 is not limited to rubber or elastomer, and other elastic materials can be used.
In the wiping position, the upper end portion of the wiper blade 44 is positioned at a height at which the wiper blade 44 can contact the nozzle forming surface. For this reason, when the recording head 3 moves from the home position to the recording area, the upper end portion of the wiper blade 44 comes into contact with the nozzle forming surface so as to wipe off dirt such as ink and paper dust adhered to the nozzle forming surface. It has become.
[0037]
The blade support member 47 is disposed ahead of the wiper blade 44 in the passing direction of the recording head 3 at the time of wiping, and the height thereof does not contact the nozzle forming surface at the wiping position, that is, at the time of wiping. In addition, as shown in FIG. 6, the surface facing the wiper blade 44, that is, the surface on the home position side, has a curved surface S formed by bending in a circular arc shape. ing. The curved surface S is set to a curvature close to a state where the wiper blade 44 is bent at the time of wiping. That is, the blade support member 47 supports the wiper blade 44 at the time of wiping in a state of leaning on the curved surface S.
[0038]
In the present embodiment, the blade support member 47 is integrally formed with the wiper holder 45 by synthetic resin such as ABS resin. Thereby, the blade support member 47 can be provided relatively easily and at low cost. If there is no problem in terms of cost, the blade support member 47 and the wiper holder 45 may be assembled after being individually molded.
[0039]
Next, the wiping operation by the wiping mechanism 14 will be described with reference to FIG.
As shown in FIG. 7A, when the recording head 3 (carriage 4) moves from the home position side toward the recording area side, the wiper holder 45 causes the wiper blade 44 to be moved by the wiper moving mechanism 46 (see FIG. 2). Is positioned at a wiping position where the recording head 3 can be contacted.
When the recording head 3 moves toward the recording area while being in contact with the wiper blade 44, the wiper blade 44 is gradually bent toward the blade support member 47 side.
[0040]
As described above, since the wiper blade 44 is formed of a relatively flexible material, the repulsive force is small when the wiper blade 44 is not supported by the blade support member 47, and dirt adhered to the side surface of the recording head 3 is formed in the nozzle. There is little possibility of polluting the nozzle forming surface by dragging to the surface side.
[0041]
When the recording head 3 reaches above the wiping mechanism 14, the wiper blade 44 leans against the blade support member 47 and makes the upper end contact (slid) with the nozzle forming surface of the recording head 3 to form this nozzle. The surface is wiped off (the state shown in FIG. 7B).
As a result, a contact pressure sufficient to wipe off the dirt on the nozzle forming surface is obtained, and the contact portion of the wiper blade 44 with the nozzle forming surface comes into contact with the nozzle forming surface while deforming following the uneven shape of the nozzle forming surface. It becomes possible to wipe the nozzle forming surface evenly.
Further, since the wiper blade 44 is supported by the entire curved surface S of the blade support member 47, the posture at the time of wiping is stable, and the wiper blade 44 can be wiped while keeping the contact pressure constant over the entire surface of the nozzle formation surface. It is possible to more efficiently remove dirt on the nozzle forming surface.
[0042]
Then, as shown in FIG. 7C, when the recording head 3 further advances to the recording area side, the contact state between the wiper blade 44 and the nozzle forming surface is released. At this time, for example, when a wiper blade 44 having a high hardness (high modulus of elasticity) is used, the wiped ink is vigorously moved back to the original upright state. There is a risk of getting dirty inside.
However, in this embodiment, since the wiper blade 44 formed of a softer material is used, the bent state returns to the original upright state relatively gently. Thereby, it is difficult to blow off the wiped ink and the like, and there is little possibility of contaminating the inside of the apparatus.
[0043]
As described above, when the recording head 3 moves from the home position to the recording area side, ink, paper dust, or the like attached to the nozzle forming surface is wiped off by the wiping mechanism 14.
[0044]
By the way, the present invention is not limited to the above embodiment, and various modifications can be made based on the description of the scope of claims.
In the above description, each of the wiping mechanism 14 and the capping mechanism 15 is an independent mechanism. However, the present invention can be applied to a case where the wiping mechanism 14 and the capping mechanism 15 are integrated. Specifically, the wiper blade 44 and the blade support member 47 can be provided on the slide mechanism 20. In this case, the slider 24 functions as a wiper holding member, and the slide mechanism 20 functions as a wiper moving mechanism.
[0045]
The blade support member 47 may have other configurations as long as it has a curved surface S. For example, as shown in FIG. 8, the blade support member 47 may be configured in a frame shape with a metal wire. In this case, the virtual surface partitioned by the wire functions as a curved surface S.
Further, for example, as shown in FIG. 9, the blade support member 47 may be a synthetic resin or a metal plate. The blade support member 47 also has a curved surface S in which the surface facing the wiper blade 44 is curved in an arc shape. 8 and 9, the wiper blade 44 is not shown.
[0046]
Further, the blade support member 47 may be slightly bent or may be hardly bent. However, the blade support member 47 is preferably formed of a material having a larger elastic modulus than that of the wiper blade 44. The point is that the wiper blade 44 can be supported to such an extent that a contact pressure sufficient to wipe off the dirt on the nozzle forming surface can be obtained.
[0047]
In the above-described embodiment, an example in which wiping is performed when the recording head 3 moves from the home position to the recording area side is shown. However, wiping is also performed when the recording head 3 moves from the recording area side to the home position side. You may do it. In this case, another blade support member 47 may be disposed on the opposite side with the wiper blade 44 interposed therebetween and with the saddle curved surface S facing the wiper blade 44 side.
[0048]
In the above, an ink jet printer which is a kind of liquid ejecting apparatus has been described as an example, but the present invention can also be applied to other liquid ejecting apparatuses. For example, a display manufacturing apparatus that manufactures color filters such as liquid crystal displays, an electrode manufacturing apparatus that forms electrodes such as organic EL (Electro Luminescence) displays and FEDs (surface emitting displays), and chips that manufacture biochips (biochemical elements) The present invention can also be applied to a manufacturing apparatus and a micropipette that supplies an accurate amount of a very small amount of sample solution. In the display manufacturing apparatus, a solution of each color material of R (Red), G (Green), and B (Blue) is discharged from the color material ejecting head. Moreover, in an electrode manufacturing apparatus, a liquid electrode material is discharged from an electrode material ejection head. In the chip manufacturing apparatus, a bioorganic solution is discharged from a bioorganic ejecting head.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating a configuration of a printer.
FIG. 2 is a plan view of a wiping mechanism and a capping mechanism.
FIGS. 3A and 3B are diagrams illustrating states of the wiping mechanism and the capping mechanism, wherein FIG. 3A illustrates a retracted state of both mechanisms, and FIG. 3B illustrates a wiping position of the wiping mechanism and a capping state of the capping mechanism; FIG.
FIG. 4 is a schematic diagram of a wiping mechanism and a capping mechanism.
FIG. 5 is a diagram illustrating the structure of a pump unit.
FIG. 6 is a perspective view showing an external appearance of a blade support member.
FIGS. 7A and 7B are diagrams for explaining the operation of the wiping mechanism, where FIG. 7A shows the start of wiping, FIG. 7B shows the state during wiping, and FIG.
FIG. 8 is a perspective view showing an external appearance when a blade support member is configured in a frame shape with wires.
FIG. 9 is a perspective view showing an external appearance when a blade support member is made of a plate material.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Inkjet printer, 2 ... Cartridge mounting part, 3 ... Recording head, 4 ... Carriage, 5 ... Ink cartridge, 6 ... Guide rod, 7 ... Recording paper, 8 ... Drive pulley, 9 ... Free-wheel pulley, 10 ... Timing Belt 11, pulse motor 12, paper feed roller 13, paper feed motor 14 wiping mechanism 15 capping mechanism 18 negative pressure part 19 cap member 20 slide mechanism 22 drainage port , 23 ... Liquid absorbing sheet, 24 ... Slider, 25 ... Long hole, 26 ... Holder member, 27 ... Frame, 30 ... Engagement shaft, 31 ... Arm member, 32 ... Support shaft, 33 ... Platen, 34 ... Spring, 35 ... Contact protrusion 36, Contact part, 38 ... Drain tank, 39 ... Drain tube, 40 ... Pump unit, 41 ... Roller, 44 ... Wiper blade, 45 Wiper holder, 46 ... wiper moving mechanism, 47 ... blade support member

Claims (4)

A liquid ejecting head that ejects liquid droplets from a nozzle;
A wiper blade that has elasticity and wipes the nozzle forming surface in contact with the nozzle forming surface of the liquid jet head;
A wiper holding member for holding the wiper blade;
A wiper moving mechanism for moving the wiper holding member to a position where an upper part of the wiper blade can contact the nozzle forming surface;
In a liquid ejecting apparatus comprising:
A blade support member is erected side by side with the wiper blade on the wiper holding member,
The blade support member is
With respect to the wiper blade, the wiper blade is disposed at the front of the liquid ejecting head during wiping,
Its height is set lower than the wiper blade at the time of wiping,
The surface facing the wiper blade has a curved surface curved in an arc shape,
A liquid ejecting apparatus, wherein the wiper blade at the time of wiping is supported in a state of leaning against the curved surface. The liquid ejecting apparatus according to claim 1, wherein the blade support member is made of a material having a larger elastic modulus than the wiper blade. The liquid ejecting apparatus according to claim 1, wherein the blade support member is made of synthetic resin or metal. The liquid ejecting apparatus according to claim 1, wherein the blade support member is integrally formed with the wiper holding member.

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