JP4096667B2 - Liquid ejector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a recording head for an ink jet recording apparatus that forms an image on recording paper by ejecting ink droplets from a nozzle opening, a color material ejecting head for a display manufacturing apparatus, an electrode material ejecting head for an electrode forming apparatus, or A liquid recovery unit that receives a liquid ejected when a flushing drive signal is supplied to the liquid ejecting head, including a liquid ejecting head capable of ejecting a liquid in a droplet state, such as an organic matter ejecting head for a biochip manufacturing apparatus, The present invention relates to a liquid ejecting apparatus disposed in a movement path of the liquid ejecting head.
[0002]
[Prior art]
For example, an ink jet recording apparatus of a serial printing system that is one form of a liquid ejecting apparatus is mounted on a carriage and is scanned with a liquid ejecting head (scanning in the main scanning direction that is the width direction of a target (hereinafter referred to as recording paper)). And a paper feeding means for transporting the recording paper in the sub-scanning direction perpendicular to the scanning direction of the recording head. Liquid (hereinafter referred to as ink droplets) is supplied from the recording head corresponding to the print data. By ejecting, printing is performed on the recording paper.
[0003]
In such an ink jet recording head, printing is performed by ejecting ink pressurized in a pressure generating chamber as ink droplets from a nozzle opening onto a recording sheet. There is a problem that printing failure occurs due to rising, solidification of ink, adhesion of dust, and mixing of bubbles. For this reason, this type of recording apparatus includes a capping unit for sealing the nozzle opening of the recording head during non-printing, and a wiping member for wiping and cleaning the nozzle forming surface as necessary. .
[0004]
The capping unit not only functions as a lid for preventing the ink in the nozzle opening of the recording head from drying out during printing suspension, but also applies a negative pressure from the suction pump when the nozzle opening is clogged. In response, the ink is sucked and discharged from the nozzle opening, and has a function of eliminating clogging due to solidification of the ink in the nozzle opening and ink ejection failure due to air bubbles mixing into the ink flow path.
[0005]
The forcible suction / discharge process of ink performed to eliminate clogging of the recording head or air bubbles in the ink flow path is called a cleaning operation.For example, printing is performed after a long pause of the recording apparatus. This process is executed when resuming or when the user recognizes that the quality of the print image has deteriorated and operates a cleaning switch, for example. Then, after the ink is sucked and discharged from the recording head, an operation of wiping the nozzle forming surface of the recording head with a wiping member made of an elastic plate such as rubber is accompanied.
[0006]
In addition, the recording head has a function of ejecting ink droplets by applying a driving signal unrelated to printing, which is called a flushing operation, and is performed near the nozzle opening of the head by a wiping operation by the wiping member. This process is performed at regular intervals in order to recover the irregular meniscus that has occurred and to prevent clogging due to thickening of the ink at nozzle openings where there is little opportunity for ink droplet ejection during printing.
[0007]
FIG. 6 shows an example of a conventional ink jet recording apparatus configured to eject ink droplets toward a flushing region formed in the moving path of the recording head during a flushing operation. In FIG. 6, reference numeral 1 denotes a carriage. The carriage 1 is reciprocated in the axial direction by being guided by a guide shaft 4 supported by the left and right frames 2 and 3 via a timing belt driven by a carriage motor (not shown). It is configured to be.
[0008]
An ink jet recording head 5 is mounted on the carriage 1 downward, and a black ink cartridge 6 and a color ink cartridge 7 for supplying ink to the recording head 5 are detachably mounted on the carriage 1. Has been. Below the recording head 5, a paper feed member 8 is arranged corresponding to the main scanning direction, and the recording paper 9 placed on the paper feed member 8 is fed by a paper feed means (not shown). The recording head 5 can be sequentially moved in the sub-scanning direction orthogonal to the scanning direction of the recording head 5.
[0009]
Reference numeral 10 in the figure is a capping unit arranged in a non-printing area (home position), and when the recording head 5 moves directly above, it moves upward to seal the nozzle formation surface of the recording head 5. It is configured to be able to. A suction pump 11 for applying a negative pressure to the internal space of the capping unit 10 is disposed in the vicinity of the capping unit 10.
[0010]
The capping means 10 functions as a lid for preventing the nozzle openings of the recording head 5 from drying during the rest period of the recording apparatus as described above, and also applies a negative pressure from the suction pump 11 to the recording head 5. Also, it has a function as a cleaning means for sucking and discharging ink. A wiping member 12 formed of an elastic plate such as rubber is disposed on the printing area side adjacent to the capping means 10, and the recording head 5 is moved when the carriage 1 reciprocates toward the capping means 10 side. A wiping operation for wiping the nozzle forming surface is performed.
[0011]
On the other hand, a flushing region 13 is formed in the vicinity of the other end facing the capping means 10 through the central printing region. The flushing region 13 is constituted by an opening hole formed so as to penetrate the paper feeding member 8. A part of the waste liquid absorbing material 14 that absorbs and holds the ink discharged from the capping means 10 through the suction pump 11 is disposed at the inner bottom of the opening hole forming the flushing region 13. The material 14 is stored in an absorbent material storage case arranged along the paper feed member 8, that is, a waste liquid tank 15.
[0012]
By the way, the recording apparatus as described above is configured such that flushing is periodically performed in order to prevent ejection failure due to ink thickening at an unused nozzle. Particularly, in recent models, flushing is performed on the order of several tens of shots / nozzle every few seconds on average. In this flushing operation, several thousand to several tens of thousands of shots may be ejected from each nozzle periodically to prevent color mixing at the timing after the cleaning operation, or at the timing at the start of printing, and also during printing. is there.
[0013]
When the opening hole is formed in the paper feeding member 8 as the flushing region 13 as shown in FIG. 6, the distance from the nozzle forming surface of the recording head 5 to the waste liquid absorbing material 14 is about several tens of mm, and the ink droplet It is inevitable that the flight distance will increase. For this reason, some of the ink droplets ejected from the nozzle openings of the recording head become mist (mist-like ink) by air resistance before reaching the absorber 14, and float as indicated by arrows. There arises a problem that the inside of the apparatus including the paper is contaminated.
[0014]
In addition, the ink droplets ejected from the nozzle openings are not a little charged and the influence of static electricity generated by the drive unit in the recording apparatus, and further the air flow by the exhaust fan arranged to suppress the temperature rise in the apparatus, or Acceleration is also caused by the air flow accompanying the movement of the carriage, and the problem remains that the recording paper and the inside and outside of the recording apparatus are contaminated as described above. In particular, such a problem appears more conspicuously in recent printing apparatuses in which the amount of each ink droplet is controlled as small as possible in order to realize high image quality.
[0015]
Therefore, an air flow path formed so as to be folded back in the flushing area 13 is provided, and an exhaust fan is disposed at the end portion of the air flow path to generate an air flow in the air flow path, whereby the flushing area The structure etc. which capture the mist inside were considered. (For example, see Patent Document 1)
[0016]
[Patent Document 1]
JP 2001-191557 A (5th page, 6th page, FIG. 2)
[0017]
[Problems to be solved by the invention]
However, the configuration in which the mist is captured by the air flow path requires the exhaust fan for generating an air flow in the air flow path as described above to be disposed at the end of the air flow path, which increases the size of the printer. was there.
The present invention has been made in view of the above-described problems, and can effectively capture and collect ink mist that floats as fine droplets using a compact mechanism, particularly during a flushing operation. An object of the present invention is to provide an ink jet recording apparatus, and thereby an ink jet recording apparatus that does not contaminate the inside and outside of the apparatus.
[0018]
[Means for Solving the Problems]
A liquid ejecting apparatus according to the present invention made to achieve the above object is mounted on a carriage that scans in the width direction of a target, and ejects liquid from a nozzle opening to adhere to the target; A liquid ejecting apparatus in which a liquid recovery unit that receives a liquid ejected when a flushing drive signal is supplied to the liquid ejecting head is disposed in a movement path of the liquid ejecting head, the liquid recovery unit including the liquid ejecting head A unit box having an opening for receiving the liquid ejected based on the flushing operation, a suction unit for sucking air in the unit box, and generated by the flushing operation and sucked together with air in the unit box. And a rotor portion that captures the liquid to be collected by centrifugal separation, and The opening is formed with a guide tube that communicates in the direction of gravity, a through hole is formed in a side wall of the guide tube, and suction air is introduced at a substantially rotational center position of the rotor portion, and the rotor The portion includes a cylindrical body in which a plurality of through-holes that are rotationally driven in the circumferential direction, and a plurality of plate-like fins arranged along the axial direction on the inner peripheral surface of the cylindrical body, and the rotor portion And the suction unit are attached to both ends of the motor drive shaft with a single drive motor interposed therebetween, and are driven to rotate, whereby the rotor is opened from the opening formed in the unit box. By forming an air flow path through which air is discharged by the suction unit, a mist in which liquid ejected based on the flushing operation floats due to air resistance An air flow path for capturing air on the inner peripheral surface side of the cylindrical body by forced movement due to centrifugal separation by rotation driving, and for discharging air from the mist that could not be collected on the inner peripheral surface side of the cylindrical body by the suction unit It is characterized in that it collects on the suction unit side .
[0019]
In this case, an inclined surface that is inclined in the gravitational direction is formed in the opening that receives the liquid, and the guide tube may be communicated with the lower end of the inclined surface in the gravitational direction. .
[0020]
Further, a through hole communicating with the guide pipe is formed in a lower bottom portion of the waste liquid collecting housing, and the collected liquid waste liquid can be discharged to the guide pipe side through the through hole. Also good.
[0021]
Further, the lower end portion of the guide pipe may be opened so that the liquid waste liquid transmitted through the guide pipe can be dropped into a waste liquid tank disposed immediately below.
[0022]
Further, an air discharge port for discharging the air sucked by the centrifugal fan is formed in a part of the peripheral surface of the cylindrical cover member arranged so as to surround the periphery of the centrifugal fan, and a filter is formed in the air discharge port. Members may be placed.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an ink jet recording apparatus according to the invention will be described with reference to an embodiment shown in the drawings. FIG. 1 is a perspective view showing a basic configuration of a recording apparatus main body to which the present invention is applied. In FIG. 1, reference numeral 21 denotes a carriage, which is guided by a guide member 24 via a timing belt 23 driven by a carriage motor 22 and reciprocates in the main scanning direction along the longitudinal direction of the paper feed member 25. It is configured to be.
[0030]
A paper feed roller 26 is disposed on the paper feed member 25, and the recording paper 27 sandwiched between the paper feed roller 26 and a driven roller (not shown) is driven by the rotation of the paper feed roller 26. It is configured to be conveyed in the sub-scanning direction orthogonal to the scanning direction. On the upper surface of the paper feeding member 25, a large number of protrusions 25a having inclined surfaces in the sub-scanning direction are intermittently formed along the longitudinal direction of the paper feeding member 25. By conveying along the upper surface of the protrusion 25a, a predetermined gap is formed with the recording head described later.
[0031]
On the other hand, an ink jet recording head 28 is mounted on the lower surface of the carriage 21 facing the recording paper 27 as indicated by a broken line. Further, a black ink cartridge 29B for supplying ink to the recording head 28 and color ink cartridges 29C, 29M, and 29Y containing cyan, magenta, and yellow inks are adjacent to each other in the main scanning direction. In this way, it is detachably mounted.
[0032]
Reference numeral 30 in the figure denotes a capping unit disposed in a non-printing area (home position). The capping unit 30 moves upward when the recording head 28 moves directly above, and forms a nozzle forming surface of the recording head. (In this embodiment, the lower surface of the recording head 28) can be sealed. A suction pump 31 for applying a negative pressure to the internal space of the capping unit 30 is disposed adjacent to the capping unit 30.
[0033]
The capping unit 30 functions as a lid that seals the nozzle formation surface of the recording head 28 and suppresses evaporation of the ink solvent from the nozzle opening during the rest period of the recording apparatus, and from the suction pump 31. A cleaning operation for applying a negative pressure to the recording head 28 to suck and discharge ink from the recording head is also executed.
[0034]
As shown in FIG. 1, a wiping member 32 in which an elastic material such as rubber is formed in a strip shape is disposed on the printing area side adjacent to the capping means 30, and the carriage 21 reciprocates toward the capping means 30 side. When doing so, a wiping operation is performed in which the nozzle head surface of the recording head 28 is wiped and cleaned by moving forward and backward in the moving direction of the recording head as necessary.
[0035]
Furthermore, in this embodiment, an ink recovery unit 33 is disposed immediately below the moving path of the recording head 28 between the paper feeding member 25 and the wiping member 32 described above. As will be described later, the ink collection unit 33 receives ink droplets ejected from the recording head 28 when the recording head 28 is flushed with the recording head 28 facing directly above the ink collection unit. The generated ink mist can also be captured.
[0036]
2 to 5 show the configuration of the ink recovery unit 33. FIG. 2 is an exploded perspective view of the ink recovery unit 33. FIG. 3 is a side view of the ink recovery unit 33, which will be described later. It is shown in the figure. 4 is a cross-sectional view as viewed in the direction of arrow AA in FIG. 3, and FIG. 5 is a plan view of the unit as viewed from above.
[0037]
The ink collection unit 33 is provided with a unit box 41 provided with an opening 40 for receiving ink droplets ejected based on the flushing operation of the recording head 28. That is, the recording head 28 indicated by the phantom line shown in FIG. 4 is configured to scan in the left-right direction in FIG. 4 (the arrow direction shown in the recording head 28). The opening 40 in the unit box 41 is formed with an inclined surface 42 inclined in the direction of gravity, and ink droplets ejected from the recording head 28 facing the opening 40 based on the flushing operation are , And is mainly configured to be received by the inclined surface 42. Thereby, generation | occurrence | production of the ink mist by rebounding of an ink drop can be reduced.
[0038]
Further, as shown in FIG. 4, the unit box 41 is formed with a guide tube 43 communicating with the gravity direction at the lower end of the inclined surface 42 in the gravity direction. Therefore, the ink droplet received on the inclined surface 42 flows downward along the inclined surface 42 and flows down through the guide tube 43 communicating in the direction of gravity. A lower end portion of the guide tube 43 is opened to form an ink discharge port 44, and a waste liquid tank 61 is disposed immediately below the ink discharge port 44. Therefore, the waste ink liquid transmitted through the guide pipe 43 is dropped onto the waste liquid absorbing material 62 accommodated in the waste liquid tank 61 so as to be absorbed and held.
[0039]
On the other hand, a cylindrical through hole 45 is formed in the side wall of the guide pipe 43 as shown in FIG. 4, and the rotor portion, which will be described later, passes through the through hole 45 at a substantially rotational center position. The air sucked by a suction unit described later is configured to be introduced. Therefore, the ink mist generated by colliding with the inclined surface 42 and the ink mist generated during the flight of the ink droplet are surely sucked together with the air into the guide tube 43 communicating with the opening 40, and guided. It is introduced to the position of the rotation center of the rotor part through a through hole 45 formed in the side wall of the pipe 43.
[0040]
As shown in FIGS. 2 and 4, the rotor portion 47 is attached to one end portion of a drive shaft 48a in the drive motor 48 and is rotationally driven in the circumferential direction, and the cylindrical body 47a A plurality of plate-like fins 47b arranged at equal intervals along the axial direction and a plurality of through holes 47c formed so as to penetrate the cylindrical body 47a are provided on the inner peripheral surface. A waste liquid collecting housing 50 is formed integrally with the unit box 41 so as to surround the peripheral surface of the cylindrical body 47 a constituting the rotor portion 47.
[0041]
Therefore, when the drive motor 48 is driven to rotate, the ink mist sucked together with the air into the unit box 41 by the suction unit described later is introduced almost at the rotational center position of the rotor portion 47. The ink mist is rotated by the flat fins 47b formed in the rotor portion 47, is brought to the inner peripheral surface side of the cylindrical body 47a, is captured by the centrifugal separation action, and is collected as ink waste liquid. The recovered ink waste liquid flies to the outer peripheral surface side of the cylindrical body 47a through a plurality of through holes 47c formed in the cylindrical body 47a, and is received by the housing 50 for recovering the waste liquid.
[0042]
On the other hand, a through hole 51 communicating with the guide pipe 43 as shown in FIG. 4 is formed in the lower bottom portion of the waste liquid collecting housing 50, which was collected by the centrifugal action of the rotor portion 47. The ink waste liquid travels along the inner peripheral surface of the housing 50, gathers at the through hole 51 formed at the lower end in the direction of gravity, and is discharged to the guide pipe 43 side through the through hole 51. Therefore, the ink waste liquid recovered by the centrifugal separation action of the rotor portion 47 is dropped onto the waste liquid absorbing material 62 accommodated in the waste liquid tank 61 from the ink discharge port 44 at the lower end portion via the guide tube 43. It is made like.
[0043]
The drive motor 48 is mounted in a recessed portion 53a formed at a substantially central portion of the motor frame 53, and a relatively large diameter air circulation hole 53b is formed in the recessed portion 53a. The motor frame 53 closes the waste liquid collecting housing 50 at the end face. A suction fan 55 constituting a suction unit is attached to the other end of the drive shaft 48a of the drive motor 48. The suction fan 55 is constituted by a centrifugal fan including a disk-like member 55a that is rotationally driven by the drive motor 48 and a plurality of blade members 55b that are radially arranged on one side surface of the disk-like member.
[0044]
A cylindrical cover member 53c is formed integrally with the motor frame 53 so as to surround the periphery of the centrifugal fan 55 constituting the suction unit. A lid 56 is disposed on the other side of the disc-shaped member 55a constituting the centrifugal fan 55. The lid 56 closes the cylindrical cover member 53c at its end surface, and the centrifugal fan 55 is closed. It is made to surround.
[0045]
On the other hand, an air discharge port 58 for discharging the air sucked by the centrifugal fan 55 is formed in a part of the peripheral surface of the cylindrical cover member 53c, and the centrifugal fan 55 turns clockwise (clockwise) in FIG. By being rotationally driven in the direction, the suction air is discharged from the air discharge port 58. Thereby, an air flow path indicated by a two-dot chain line through which air is discharged from the opening 40 formed in the unit box 41 by the centrifugal fan 55 through the rotor portion 47 is formed.
[0046]
In addition, a filter member 59 formed in a rectangular shape is attached to the inner surface of the lid 56 forming the air discharge port 58 by, for example, an adhesive or a double-sided tape (not shown). When 56 covers the cylindrical cover member 53c at its end face, the filter member 59 is configured to be positioned at the air discharge port 58. With this configuration, a small amount of ink mist that cannot be recovered by the centrifugal separation action in the rotor 47 is effectively recovered by the filter member 59. As described above, by arranging the filter member 59 in the air discharge port 58, it is possible to effectively collect a little residual ink mist and contribute to reducing the amount of use of a relatively expensive filter member. it can.
[0047]
Further, in the above-described embodiment, the ink recovery unit is arranged on the home position side where the capping means is arranged. However, the ink recovery unit is configured to perform printing opposed to the home position across the printing area. You may arrange | position at the edge part side of an area | region. If necessary, they may be arranged on the home position side and on the end side of the print area facing the home position across the print area.
[0048]
In the above embodiment, an ink jet recording apparatus which is a kind of liquid ejecting apparatus has been described as an example. However, the present invention is another liquid ejecting apparatus, for example, a color material ejecting apparatus or an electrode forming apparatus for a display manufacturing apparatus. The present invention can also be applied to an electrode material injection device for use in an organic material or an organic matter injection device for a biochip manufacturing device.
[0049]
【The invention's effect】
As is apparent from the above description, according to the liquid ejecting apparatus according to the present invention, the liquid recovery unit that receives the liquid ejected when the flushing drive signal is supplied to the liquid ejecting head includes a unit that includes an opening that receives the liquid. A box, a suction unit for sucking air in the unit box, and a rotor part for capturing a liquid generated by the flushing operation and sucked together with the air in the unit box by a centrifugal separation action. The liquid can be efficiently captured and recovered as a waste liquid by a compact mechanism that uses the centrifugal separation action. Therefore, it is possible to provide a liquid ejecting apparatus that does not contaminate the inside and outside of the apparatus with the liquid ejected at the time of flushing and does not become larger than necessary.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a basic configuration of a recording apparatus main body to which the invention is applied.
FIG. 2 is an exploded perspective view showing a configuration of an ink recovery unit provided in the recording apparatus shown in FIG.
FIG. 3 is a side view of the ink recovery unit as seen from the suction unit side.
4 is a cross-sectional view in a state viewed in the direction of arrow AA in FIG. 3;
FIG. 5 is a plan view of the ink recovery unit as seen from above.
FIG. 6 is a longitudinal sectional view showing an example of forming a flushing region in a conventional ink jet recording apparatus.
[Explanation of symbols]
21 Carriage 24 Guide member 25 Paper feed member 26 Paper feed roller 27 Recording paper 28 Recording heads 29B to 29Y Ink cartridge 30 Capping means 31 Suction pump 32 Wiping member 33 Ink recovery unit 40 Opening 41 Unit box 42 Inclined surface 43 Guide tube 44 Ink discharge port 45 Through hole 47 Rotor 47a Cylindrical body 47b Flat fin 47c Through hole 48 Drive motor 48a Motor drive shaft 50 Waste liquid recovery housing 51 Through hole 53 Motor frame 53c Cover member 55 Suction unit (centrifugal fan)
55a Disc-like member 55b Blade member 56 Lid 58 Air outlet 59 Filter member 61 Waste liquid tank 62 Waste liquid absorber

Claims (5)

Loaded on a carriage for scanning in the width direction of the target, and the liquid ejecting head is attached to the target by ejecting liquid from a nozzle opening,
And the liquid recovery unit for receiving the liquid ejected when supplied flushing drive signal to the liquid ejecting head,
The A liquid ejecting apparatus disposed in the movement path of the liquid ejecting head,
The liquid recovery unit is
A unit box having an opening for receiving the liquid ejected based on the flushing operation of the liquid ejecting head;
A suction unit for sucking air in the unit box;
A rotor portion which is generated by the flushing operation to capture the liquid to be sucked together with the air into the unit box by centrifugal separation action,
Equipped with,
Further, the opening is formed with a guide tube communicating in the direction of gravity, a through hole is formed in a side wall of the guide tube, and suction air is introduced to a substantially rotational center position of the rotor portion,
The rotor portion includes a cylindrical body in which a plurality of through holes that rotate in the circumferential direction are formed, and a plurality of plate-like fins arranged along the axial direction on the inner peripheral surface of the cylindrical body,
The rotor portion and the suction unit are attached to both ends of the motor drive shaft with one drive motor interposed therebetween, and are configured to be rotationally driven, whereby an opening formed in the unit box By forming an air flow path for discharging air by the suction unit through the rotor portion from
The mist in which the liquid ejected based on the flushing operation floats due to air resistance is captured on the inner peripheral surface side of the cylindrical body by the forced movement by the centrifugal action by the rotation drive, and the inner peripheral surface of the cylindrical body The mist that could not be collected on the side is collected on the suction unit side by an air flow path that discharges air by the suction unit;
A liquid ejecting apparatus. The said opening part which receives a liquid is formed so that the inclined surface inclined in the gravity direction may be formed, and the said guide pipe may be connected in the lower end part of the gravity direction in the said inclined surface. Liquid ejector. 2. A lower hole in the waste liquid recovery housing is formed with a through hole communicating with the guide pipe, and the recovered liquid waste liquid can be discharged to the guide pipe side through the through hole. Or the liquid ejecting apparatus according to any one of 2; The liquid according to any one of claims 1 to 3, wherein a lower end portion of the guide pipe is opened, and a liquid waste liquid transmitted through the guide pipe can be dropped into a waste liquid tank disposed immediately below the liquid guide. Injection device. An air discharge port for discharging the air sucked by the centrifugal fan is formed in a part of the peripheral surface of the cylindrical cover member arranged so as to surround the centrifugal fan, and a filter member is provided in the air discharge port. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is disposed.

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