JP2001232810A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recorder in which bubbles trapped in a filter can be discharged relatively easily. SOLUTION: A head unit 1 comprising a recording head body 20 having a plurality of nozzle openings 21 for ejecting ink drops, means 2 containing ink being supplied to the recording head body 20, and a head case 14 having ink channels 16, 17 interconnecting the recording head body 20 and the ink supply means 2 is mounted on the carriage 3 of the ink jet recorder wherein the head unit 1 can discharge bubbles relatively easily through means 30 for shaking the vicinity of filters 15 disposed in the ink channels 16, 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus which is used in an ink jet recording head and has a filter for removing foreign matters, bubbles and the like in ink.

[0002]

2. Description of the Related Art In general, in an ink jet recording head, ink is supplied from an ink cartridge filled with ink through an ink supply needle and a flow path inserted into the ink cartridge. The nozzles are ejected by driving the nozzles.

[0003] Such an ink jet recording head has a problem in that, when air bubbles existing in the ink of the ink cartridge or air bubbles mixed in the ink when the ink cartridge is attached or detached are supplied, ejection failure occurs. . Also, due to foreign matter present in the ink,
Similarly, there is a problem that ejection failure occurs. Therefore, the ink flow path between the ink cartridge and the ink jet recording head usually has a plurality of fine holes,
A filter for removing bubbles and the like in the ink is mounted.

As this filter, a filter or the like in which fibers are woven and the weave is a filter hole is conventionally used, and foreign matter and bubbles are trapped when ink passes through the filter. In addition, the air bubbles trapped in the filter in this way are discharged from the nozzle openings during the head cleaning operation. Specifically, by sucking the ink from the nozzle opening to generate a flow velocity higher than that generated at the time of normal ink ejection, the bubbles pass through the filter and are discharged from the nozzle opening.

[0005]

However, when a flow rate faster than normal ink ejection is generated during cleaning, the amount of ink consumption increases, and the amount of ink used for actual printing decreases. is there. Further, in order to increase the flow rate of the ink, it is necessary to increase the size of the pump for sucking the ink, and there is a problem that the size of the head must be increased.

[0006] In view of such circumstances, it is an object of the present invention to provide an ink jet recording apparatus capable of relatively easily discharging bubbles trapped in a filter.

[0007]

According to a first aspect of the present invention, there is provided a recording head body having a plurality of nozzle openings for ejecting ink droplets, and a housing for storing ink supplied to the recording head body. In the ink jet recording apparatus in which a head unit including a supplied ink supply unit and a head case having an ink flow path communicating the recording head main body and the ink supply unit is mounted on a carriage, the head unit includes: An ink jet recording apparatus is provided with a vibrating means for vibrating the vicinity of a filter provided in the ink flow path.

In the first aspect, the vibrating means vibrates the vicinity of the filter of the head unit, so that the air bubbles trapped by the filter easily pass through the filter.

According to a second aspect of the present invention, there is provided an ink jet recording apparatus according to the first aspect, wherein the vibration means is provided closer to the ink supply means than the filter.

In the second aspect, the vibrating means is provided in the vicinity of the bubbles trapped and accumulated in the filter, so that the bubbles are more reliably divided.

According to a third aspect of the present invention, there is provided the ink jet recording apparatus according to the first or second aspect, wherein the vibrating means generates an ultrasonic minute vibration.

In the third aspect, the bubbles are more reliably divided finely by the ultrasonic vibration.

A fourth aspect of the present invention is the ink jet recording apparatus according to the first or second aspect, wherein the vibrating means generates a relatively large shock wave-like vibration.

In the fourth aspect, the meniscus of the bubble is broken by the relatively large shock wave-like vibration, and the bubble easily passes through the filter.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the vibrating means is an actuator device having a piezoelectric element provided on a surface of the head unit. Ink jet recording apparatus.

In the fifth aspect, the head unit can be relatively easily vibrated by driving the piezoelectric element.

According to a sixth aspect of the present invention, in the first or second aspect, the vibrating means has a protrusion which is provided at a position facing the head unit and is elastically deformed. An ink jet recording apparatus is characterized in that the mounted carriage is moved to bring the head unit into contact with the protrusion.

In the sixth aspect, the head unit vibrates when it comes into contact with the projection.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the vibrating means is fixed to the ink supply means side of the head case and inserted into the ink supply means. An ink jet recording apparatus is provided on an ink supply needle.

In the seventh aspect, by providing the vibrating means to the ink supply needle, the vicinity of the filter vibrates reliably.

An eighth aspect of the present invention is the ink jet recording apparatus according to any one of the first to seventh aspects, wherein the vibrating means is driven during a cleaning operation of the nozzle opening. .

In the eighth aspect, since the bubbles in the ink flow path are reliably discharged to the outside, printing defects such as missing dots can be prevented.

A ninth aspect of the present invention is the ink jet recording apparatus according to the eighth aspect, wherein the vibrating means is driven when ink is sucked from the nozzle opening.

In the ninth aspect, the bubbles in the ink flow path are reliably discharged from the nozzle opening to the outside by suction.

A tenth aspect of the present invention is the ink jet recording apparatus according to the ninth aspect, wherein the vibrating means is driven at a timing at which bubbles come into contact with the filter.

In the tenth aspect, the meniscus of the bubble is broken by the vibration of the vibration means, and the bubble passes through the filter more reliably.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments.

(Embodiment 1) FIG. 1 is a schematic view showing an example of an ink jet recording apparatus according to Embodiment 1.
FIG. 2 is a cross-sectional view schematically showing the head unit, and FIG. 3 is a cross-sectional view showing a main part of the head unit.

As shown in FIG. 1, in this embodiment, a head unit 1 (1A and 1B) having a recording head body, which is an ink jet recording head, includes an ink cartridge 2 (2A and 2B) constituting an ink supply means. Are detachably provided, and these head units 1A and 1A
The carriage 3 on which B is mounted is provided movably in the axial direction on a carriage shaft 5 attached to the apparatus main body 4. These head units 1A and 1B discharge a black ink composition and a color ink composition, respectively.

Then, the driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears (not shown) and the timing belt 7, so that the head units 1A and 1
The carriage 3 on which B is mounted is moved along the carriage shaft 5. On the other hand, a platen 8 is provided on the apparatus main body 4 along the carriage shaft 5, and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller (not shown), is wound around the platen 8. It is designed to be transported.

In such an ink jet recording apparatus, the carriage 3 is moved along the carriage shaft 5 and ink is ejected by the ink jet recording head to print on the recording sheet S.

A cap 9 is provided on the side of the platen 8 which is the end of the carriage 3 in the moving direction, and a suction pump (not shown) is connected to the cap 9. A cleaning operation is performed. In addition, the cap 9 also
Capping the head end surface of the recording head body which is waiting for printing for a predetermined time or more to prevent drying of the nozzle openings.

Further, as shown in FIG. 2, the head unit 1 mounted on the ink jet type recording apparatus of this embodiment has a frame 11 which forms an outer frame of the head unit 1.
An ink supply needle 13 inserted into an ink supply hole of the ink cartridge 2, and a head case 14 provided between the ink supply needle 13 and the recording head body 20 having the nozzle opening 21. A filter 15 for trapping air bubbles or foreign matter in the ink is provided between the head case 13 and the head case 14.

Here, as shown in FIG. 3A, ink flow paths 16 and 17 are formed in the ink supply needle 13 and the head case 14 so as to extend in a direction substantially perpendicular to the filter 15. A portion near the end of the ink flow path 16 of the ink supply needle 13 on the filter 15 side is a hemispherical filter chamber 18 whose diameter gradually increases toward the filter 15. The filter chamber 18 is a space for storing bubbles trapped by the filter 15 and the like, and can store a predetermined amount of bubbles without the bubbles coming into contact with the filter 15.

On the outer surface near the filter 15, for example, the outer surface of the filter chamber 18 of the ink supply needle 13,
In the present embodiment, a vibrating means 30 composed of an actuator device having a piezoelectric element is provided, and vibrates the ink supply needle 13 and the filter 15 in the vicinity of the filter 15 of the head unit 1, as will be described in detail later.
Thus, the air bubbles trapped in the filter 15 can be easily discharged.

Here, an actuator device which is the vibration means of the present embodiment will be described.

The vibrating means 30 of the present embodiment is similar to that of FIG.
As shown in FIG. 7, the actuator device has a vertical vibration type piezoelectric element, and the front end of the piezoelectric element 32 is in contact with the outer surface of the area corresponding to the filter chamber 18 of the ink supply needle 13 via the vibration plate 31. Have been. These piezoelectric elements 32
Are laminated with a piezoelectric material 33 and electrode forming materials 34 and 35 alternately and vertically sandwiched therebetween, and an inactive region that does not contribute to vibration is fixed to a fixed substrate 36. Note that the fixed substrate 36 and the diaphragm 31 are integrally fixed via a base 37.

In the actuator device configured as described above, when a voltage is applied to the piezoelectric element 32, the piezoelectric element 32 contracts, and when the voltage is released, the piezoelectric element is expanded and returns to the original state. Further, the vibration means 30 vibrates the ink supply needle 13 and the filter 15 via the vibration plate 31 by repeating the application and release of the voltage to the piezoelectric element 32 in this manner.

Here, in such an ink jet type recording apparatus, the cleaning operation of the head is performed at a predetermined timing as described above. This cleaning operation includes a cleaning operation of sucking a small amount of ink, for example, about 0.2 to 0.3 g of ink, and only eliminating or preventing clogging of the nozzle opening.
Almost all of the ink in the nozzle 17, for example, about 1 g of ink, is sucked to eliminate or prevent clogging of the nozzle opening 21 of the recording head main body 20, and the air bubbles and the like trapped in the filter 15 are discharged to the outside. There are two types: a cleaning operation for eliminating or preventing printing defects such as missing dots.

In this embodiment, the vibrating means 30 composed of an actuator device provided on the outer surface of the ink supply needle 13 is driven to vibrate the ink supply needle 13 and the filter 15 during the latter cleaning operation. As a result, the air bubbles trapped in the filter 15 are removed from the filter 1.
5 is finely divided so as to be able to pass through, and is sucked by a suction pump or the like, and is discharged to the outside from the nozzle opening 21 together with the ink.

In this embodiment, the vibration means 30 is
The ink supply needle 13 continuously generates ultrasonic microvibrations.
And the filter 15 is vibrated.

As described above, the bubbles trapped in the filter 15 are finely divided by the vibrating means 30, and the bubbles pass through the filter by the suction of the suction pump. Can be discharged.

Since the air bubbles trapped in the filter 15 can be reliably discharged by the cleaning operation, the air bubbles can fill the filter chamber 18 even if the volume of the filter chamber 18 on the filter 15 is made relatively small. Therefore, printing defects can be reliably prevented and the size of the head can be reduced.

Further, by finely dividing the air bubbles, the air bubbles can be reliably eliminated even if the flow rate of the ink due to the suction of the suction pump is relatively low, and the amount of ink discharged during the cleaning operation can be reduced. Therefore, the amount of ink actually used for printing increases, and the running cost can be reduced.

In the present embodiment, the vibrating means 30 vibrates the ink supply needle 13 and the filter 15 by continuously generated ultrasonic waves, whereby the bubbles are finely divided and passed through the filter 15. However, the invention is not limited to this. For example, the vibration means 30 may generate a relatively large vibration like a strong shock wave. In this case, after the suction of the ink is started by the suction pump, a relatively large shock wave-like vibration is generated in the vibrating means 30 at the timing when the air bubbles come into contact with the filter 15 and the filter
Is vibrated, the meniscus of the bubbles in contact with the filter 15 is destroyed by the shock due to the vibration, and the bubbles are
Can easily pass through.

Further, in the present embodiment, the vibration means 30 is provided on the outer surface of the ink supply needle 13. However, the vibration means is not particularly limited as long as it is in the vicinity of the filter 15.
As shown in (1), it may be provided on the outer surface of the head case 14.

The configuration of the recording head body 20 used in the head unit 1 according to the present embodiment is not particularly limited, and may be any configuration. An example is shown below. FIG. 5 is a cross-sectional view illustrating an example of a recording head body.

The recording head main body 20 is, for example, an ink jet recording head. As shown in FIG. 5, one surface of a flow path forming substrate 42 in which a pressure generating chamber 41 is formed is provided.
An elastic film 43 is formed. On this elastic film 43,
The lower electrode film 44, the piezoelectric layer 45, and the upper electrode film 46 are laminated and patterned, and the piezoelectric element 3 is provided for each pressure generating chamber 41.
00. An insulating layer 47 having electrical insulation is formed on the piezoelectric element 300, and a portion of the insulating layer 47 corresponding to each piezoelectric element 300 has an upper electrode for connecting to a lead electrode 48. A contact hole 47a exposing a part of the film 46 is formed. One end is connected to each upper electrode film 46 via the contact hole 47a, and the other end is formed with a lead electrode 48 extending to the connection terminal portion.

On the other hand, on the other surface side of the flow path forming substrate 42,
A nozzle forming substrate 50 provided with a nozzle opening 21 is provided, and a nozzle communication hole 52 for communicating the nozzle opening 21 with the pressure generating chamber 41 is provided with a sealing plate 53, a common ink chamber forming substrate 54, a thin plate 55, And the ink chamber side plate 56.

A common ink chamber 57 is formed by the sealing plate 53, the common ink chamber forming substrate 54, and the thin plate 55. The common ink chamber 57 and each pressure generating chamber 41 communicate with each other through an ink supply communication hole 58 formed in the sealing plate 53. An inlet 59 is formed.
An opening 56a is formed in the ink chamber side plate 56 at a portion facing the common ink chamber 57. This opening 56
Due to the thin wall 55 of the portion a, the pressure generated at the time of discharging the ink toward the side opposite to the nozzle opening 21 is absorbed,
Unnecessary positive or negative pressure is prevented from being applied to the other pressure generating chambers 41 via the common ink chamber 57.

In such an ink jet type recording head, ink is supplied to the common ink chamber 57 from the ink introduction port 59 and is distributed to each pressure generating chamber 41 through the ink supply communication hole 58. Then, after the inside is filled with ink up to the nozzle opening 21, a voltage is applied between the lower electrode film 44 and the upper electrode film 46 via the lead electrode 48 according to a recording signal from an external drive circuit (not shown). And elastic membrane 4
3. By bending and deforming the lower electrode film 44 and the piezoelectric layer 45, the pressure in the pressure generating chamber 41 increases, and ink is ejected from the nozzle opening 21.

(Embodiment 2) FIG. 6 is a schematic view showing a main part of an ink jet recording apparatus according to Embodiment 2.

In this embodiment, as shown in FIG. 6, a projection projecting toward the head unit 1 at a height corresponding to the vicinity of the filter 15 of the head unit 1 is provided on the apparatus main body 4 in a region corresponding to the cap 9. 60. Specifically, when the carriage 3 on which the head unit 1 is mounted is moved along the carriage shaft 5 from a position facing the cap 9, the tip of the projection 60 is moved to the head unit 1. It is provided to be in contact.

In this embodiment, the vibration means 30A
Constitutes a part of a drive circuit 70 composed of an IC or the like for driving the carriage 3. The carriage 3 on which the head unit 1 is mounted from a position facing the cap 9 during a cleaning operation similar to the above-described embodiment. Is reciprocated minutely. Thereby, the filter 15 of the head unit 1
The portion corresponding to the vicinity and the protruding portion 60 continuously contact a plurality of times, and the portion corresponding to the vicinity of the filter 15 of the head unit 1, that is, the ink supply needle 13 and the filter 15 vibrate.

In FIG. 6, the carriage 3 is omitted for simplicity.
Although the drive circuit 70 is illustrated as connected to the drive circuit 6, the drive circuit 70 is actually connected to the drive motor 6 to control the drive motor 6. And, as mentioned above,
When the driving force of the driving motor 6 is transmitted to the carriage 3 via the timing belt 7, the carriage 3 on which the head units 1A and 1B are mounted is moved along the carriage shaft 5 (see FIG. 1).

According to the structure of this embodiment,
As in the above-described embodiment, the vibrating means 30A vibrates the ink supply needle 13 and the filter 15, whereby the air bubbles trapped by the filter 15 are finely divided, and the air bubbles are easily and reliably discharged from the nozzle openings 21. be able to.

In this embodiment, the vibration means 30A
In the above, the carriage 3 on which the head unit 1 is mounted is reciprocated minutely so as to vibrate by making continuous contact with the projection 60 a plurality of times. However, the present invention is not limited to this. By moving the head unit 1 only once and contacting the protrusion 60,
A relatively large shock wave-like vibration may be generated.

(Other Embodiments) The embodiments of the ink jet recording apparatus according to the present invention have been described above, but the present invention is not limited to these embodiments.

For example, the vibrating means is not limited to the configuration of each of the above embodiments, but may be, for example, a plunger. In this case, the vibrating means is provided in the apparatus main body in an area corresponding to the vicinity of the filter of the head unit, and by driving the vibrating means, the leading end portion is brought into mechanical contact with the head unit, whereby Can be vibrated.

In any case, the configuration of the vibrating means is not particularly limited as long as it can vibrate the vicinity of the filter of the head unit.

[0061]

As described above, according to the present invention,
Since the vibrating means for vibrating the vicinity of the filter of the head unit is provided, when cleaning the head,
By vibrating the vicinity of the filter of the head unit by the vibrating means, the bubbles trapped in the filter can be finely divided or the meniscus of the bubbles can be broken. Therefore, the air bubbles can be easily passed through the filter and discharged from the nozzle opening to the outside reliably and easily.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing an ink jet recording apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view schematically showing a head unit according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a main part of the head unit according to the first embodiment of the present invention.

FIG. 4 is a sectional view of a main part showing another example of the head unit according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating an example of a recording head main body according to the first embodiment of the present invention.

FIG. 6 is a schematic diagram illustrating an ink jet recording apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Head unit 2 Ink cartridge 3 Carriage 4 Device main body 5 Carriage shaft 9 Cap 13 Ink supply needle 14 Head case 15 Filter 20 Recording head main body 30, 30A Vibration means 60 Projection

Claims (10)

[Claims] A recording head main body having a plurality of nozzle openings for ejecting ink droplets; an ink supply unit containing ink supplied to the recording head main body; and the recording head main body and the ink supply unit. In an ink jet recording apparatus in which a head unit including a head case having an ink flow path communicating with the head unit is mounted on a carriage, the head unit includes a vibrating unit that vibrates near a filter provided in the ink flow path. An ink jet recording apparatus comprising: 2. An ink jet recording apparatus according to claim 1, wherein said vibration means is provided closer to said ink supply means than said filter. 3. An ink jet recording apparatus according to claim 1, wherein said vibrating means generates ultrasonic micro-vibration. 4. An ink jet recording apparatus according to claim 1, wherein said vibration means generates a relatively large shock wave-like vibration. 5. An ink jet recording apparatus according to claim 1, wherein said vibrating means is an actuator device having a piezoelectric element provided on a surface of said head unit. 6. The vibrating unit according to claim 1, wherein the vibrating means has a protrusion that is provided at a position facing the head unit and is elastically deformed, and moves a carriage on which the head unit is mounted. An ink jet recording apparatus, wherein a head unit is brought into contact with the projection. 7. The ink supply needle according to claim 1, wherein the vibrating means is provided on an ink supply needle fixed to the ink supply means side of the head case and inserted into the ink supply means. An ink jet recording apparatus, comprising: 8. An ink jet recording apparatus according to claim 1, wherein said vibration means is driven during a cleaning operation of said nozzle opening. 9. An ink jet recording apparatus according to claim 8, wherein said vibrating means is driven when sucking ink from said nozzle opening. 10. The vibration control device according to claim 9, wherein:
An ink jet recording apparatus, wherein bubbles are driven at the timing of contact with the filter.