JP2553354Y2 - Inkjet head recovery device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for an ink jet printer and a bubble jet printer which perform printing by ejecting ink from a nozzle toward paper, and removes clogging and bubbles in the ink jet head. It relates to a recovery device.

[0002]

2. Description of the Related Art In the above-described ink jet printer, a plurality of ink flow paths each having a tip portion formed in a nozzle are disposed in an ink jet head unit, and at least a part of an outer peripheral wall of the ink flow path is made flexible. A piezoelectric element is provided on the outer peripheral wall while being formed of a material, and a current is applied to the piezoelectric element at a predetermined printing timing to reduce the cross-sectional area of the ink flow path, thereby ejecting ink in the ink flow path from the nozzle. And land on the paper to print. In addition, the above-described bubble jet printer includes a plurality of ink flow paths each having a tip formed in a nozzle in an ink jet head unit, and a heat generating section provided in the ink flow path to perform predetermined printing. By energizing the heat generating portion at a timing, bubbles are generated in the ink flow path, and a volume of ink corresponding to the bubbles is ejected from a nozzle to land on paper, thereby performing printing.

By the way, printers such as the above-described ink jet printers and bubble jet printers which perform printing by ejecting ink, due to the principle, cause dust to adhere to nozzles of the ink jet head or cause ink to flow in the ink flow path of the ink jet head. If air bubbles are generated in the ink jet head, a trouble of non-ejection of ink occurs.

[0004] For this reason, conventionally, an ink jet head recovers by ejecting pressurized air into an ink tank of the ink jet head to press the ink into the ink flow path at a high pressure to remove bubbles in the ink jet head. A device has been proposed.

In particular, in an ink jet printer having a detachable ink tank mounted on a carriage, bubbles are apt to be mixed into the ink supply path when the ink tank is detached. Bubbles that have entered the ink supply path when the ink tank is attached or detached travel along the ink flow path together with the ink and are carried toward the nozzles of the inkjet head. In this state, the air bubbles are carried into the nozzles, causing the nozzles to be clogged, and the ink is not ejected, so that the ink flow path between the ink tanks and the nozzles is usually provided like a buffer tank. A space is provided so that air bubbles are caught in this space and do not reach the nozzle.

However, as the amount of air accumulated in the buffer tank gradually increases while the attachment and detachment of the ink tank is repeated several times or the printer is used for a long period of time, the amount of air becomes a predetermined amount. When it becomes more, an operation of removing this air is required.

FIG. 6 shows an essential part of a general ink jet printer provided with such a conventional ink jet head recovery device, and FIG. 7 is a diagram showing a conventional ink jet head recovery device. is there.

As shown in FIG. 6, a pair of carriage shafts 2 and 2 extending in a direction parallel to the axial direction of the platen 1 are provided in front of the platen 1 having a cylindrical shape. Carriage 3 that can reciprocate along carriage axis 2
Are arranged. An ink jet head 4 capable of performing full-color printing is mounted on the carriage 3.

The ink jet head 4 has four nozzle aggregates 5 corresponding to four color inks for full color, respectively, facing the platen 1 (see FIG. 7).
Are arranged, and each nozzle assembly 5 has a tip which is vertically aligned so as to face the platen 1.
And a plurality of ink passages 17 (see FIG. 7). These nozzle assemblies 5 are fixed to a head mount 7 supported by the carriage 3. On the carriage 3 at the back of each nozzle assembly 5, each nozzle constituting the nozzle assembly 5 is provided.
An inlet 9 having a built-in auxiliary tank 8 serving as a buffer tank communicating with each nozzle 6 located at the tip of the ink passage 17 is disposed, and each inlet 9 is detachably mounted on the carriage 3. color four Lee <br/> ink cartridge 10 which is adapted to be communicated.

At the side of one end of the platen 1, each of the ink flow paths 17 constituting each of the nozzle assemblies 5 when not in use is provided.
Each and covers the tip of the nozzle 6 in which is located the distal end
Or prevent drying of the ink in the click channel 17, the ink flow
Cap device 1 used to remove air bubbles formed in the passage 17 and foreign substances clogged in each ink flow passage 17
1 is provided. The cap device 11 includes a casing 1 having an opening 12 formed on the carriage 3 side.
A cap body 14 is provided in the opening 12 of the casing 13 so as to be movable in the direction of coming into contact with and separating from the ink jet head 4. The cap body 14 corresponding to each nozzle assembly 5 of the inkjet head 4, each nozzle assembly 5 it
Nozzles that are vertically elongated so that they can be individually coated
It has a plurality of openings 15 of the same number as the body 5, and a rubber liner 16 is stretched inside each of the openings 15, and this liner 16 is arranged from the inside of the periphery of each of the openings 15. It protrudes to the outside and can be air-tightly pressed against the outer periphery of each nozzle assembly 5.

Further, each nozzle constituting the nozzle assembly 5
As shown in FIG. 7 , each ink flow path 1
Piezoelectric elements 18 are respectively arranged from the nozzle 6 at the tip of 7 a piezoelectric element for ejecting ink.

On the other hand, the cap body 1 of the cap device 11
A projection 19 substantially on a hemisphere is provided on the front surface of the upper part of the projection 4 so that the pressurizing air passage 20 communicating with the top of the projection 19 reaches the back of the cap body 14. The pressurizing means 21 such as a pump (not shown) is connected to the pressurizing air passage 20.
Further, the inside of each opening 15 of the cap body 14 is communicated with a not-shown atmosphere release valve through a communication passage 22.
Further, to each opening 15 of the cap body 14, a waste liquid pipe 23 constituting a waste liquid flow path is connected. As shown in FIG. 8, each waste liquid pipe 23 is connected to one pump , specifically a suction means 24 such as a vacuum pump, via a relay section. The used ink is stored in a waste liquid tank 36.

On the other hand, when the cap device 11 covers the ink jet head 4 on the upper surface of the head mounting base 7 facing the cap device 11, the protrusion 19 touches the nozzle and the pressurizing air passage 20 is formed. One pressurized air passage 25 that is communicated is formed, and this pressurized air passage 25 is branched into four branch passages 26 corresponding to the number of the ink cartridges 10. An air pipe 27 that communicates with the inside of each ink cartridge 10 is connected to the end.

According to the above-described conventional apparatus, at the time of printing, while the cap body 14 of the cap device 11 is retracted, the carriage 3 on which the ink jet head 4 is mounted is moved along the platen 1 to perform predetermined printing. by operating the piezoelectric element 18 of the ink flow path 17 to be used for printing of the inkjet head 4 based on the signal, the ink from the ink cartridge 10 via the inlet 9
The desired ink supplied to the flow path 17 of the ink flow path 17
Desired printing is performed by jetting from the nozzle 6 located at the leading end toward the paper on the platen 1.

When printing is completed, the carriage 3 is returned to a predetermined reference position. At this reference position, the cap device 11 is attached to the ink jet head 4, and the cap body disposed on the cap device 11 is mounted. After 14 each aperture 15 corresponding to each nozzle assembly 5 of the ink jet head 4 of the covering, respectively, the pressure means 2
1 to drive the ink or bubbles in the inkjet head 4 from the nozzle 6 of each nozzle assembly 5 into each opening 15 of the cap body 14 by the pressure of the pressurizing means 21 .
Flow down simultaneously for each color, and then, for example,
Through the communication passage 22 to the air release valve (not shown)
Driving the suction means 24 while communicating with the atmosphere to suction
The respective color inks flowing out into the respective openings 15 by the suction force of the negative pressure of the means 24 are supplied to the respective waste liquid pipes 23 constituting the waste liquid flow paths.
The recovery operation is performed by suction through the .

[0016]

Here, if inks of different colors flowing out of the respective nozzle assemblies 5 are mixed during the recovery operation, the mixed ink adheres to the nozzles 6 and this mixed color is printed during printing. Ink may be ejected. In order to prevent such inconvenience, the cap device 11 is provided with each opening 15 corresponding to each nozzle assembly 5.
There is provided in the cap body 14, respectively, as shown in FIG. 8, each waste liquid tube 23 communicating with the respective openings 15
Is supplied with a negative pressure which is a suction force of one suction means 24 ,
As a result, the ink of each color flowing down into each opening 15 is
Each is formed so as to be sucked simultaneously.

On the other hand, ink flowing down from the nozzle 6 of each nozzle assembly 5 into each opening 15 or an ink jet head
In many cases, the amount of bubbles and the like flowing out of each of the inks 4 differs for each color of ink. Will be terminated before the suction of.

That is, during the recovery operation, the pressing hand
Due to the pressure applied when the stage 21 is driven, the ink
In the jet head 4, specifically, in each ink flow path 17,
From the nozzle 6 of each nozzle assembly 5 to the cap body 1
4 flow down to each opening 15, but each nozzle assembly
Of ink flowing down from nozzle 6 of nozzle 5 into each opening 15
The output amount depends on the type of ink (color)
It will vary depending on the quantity and other reasons.

Further, the ink flowing down into each opening 15
When a vacuum pump as one suction means 24 is driven.
In the case of suctioning by suction force by negative pressure, each opening described above
In addition to the difference in the amount of ink that has flowed into the
Phase of surface roughness inside each waste liquid pipe 23 constituting the liquid flow path
No, the degree of bending due to the difference in the piping position of each waste liquid pipe 28,
Alternatively, due to the difference in length of each waste liquid pipe 28,
The four colors of ink flowing down into each opening 15 are simultaneously sucked.
It is impossible to complete
Suction of any one of the inks ends first
Will be.

When driving the suction means 24,
Opening the inside of the opening 15 to the atmosphere (not shown) through the communication passage 22.
Since the valve is driven in communication with the atmosphere by a valve, suction means
Even when the nozzle 24 is driven, the inside of the opening 15 forms the nozzle assembly 5
The Nozzle 6 Karakara further ink of each ink flow path 17 to
There is no negative pressure enough to make it flow down.

Then, the inflow flowing down into each opening 15
Suction of any one of the inks ends first
The ink does not pass through the inside of the waste liquid pipe 23 provided in the opening 15 where the suction has been completed.
This was caused by the passage of the ink inside the tube 23.
The flow resistance against the negative pressure drops significantly, and the suction ends first.
The waste liquid pipe 23 provided in the formed opening 15 sucks air in a state where the flow resistance is significantly reduced. The result
As a result, one suction means 24 flows into four openings 15.
When sucking the dropped ink at the same time,
When each ink is sucked from the opening 15,
The ink passes through each of the waste liquid pipes 23 constituting the waste liquid flow path.
And pass through the inside of each waste liquid pipe 23 at that time.
The problem is that the flow resistance due to the ink
No, but flow to one of the four openings 15
If the dropped ink is sucked in first, this ink
The waste liquid flow path communicating with the opening 15 sucked into
The flow resistance when passing through the inside of the waste liquid pipe 23 as the liquid flow path is
The air that is smaller than the liquid ink
In other words, air (large)
Ki) will be sucked. And opening of the remaining three places
The ink in the mouth 15 is used when passing through the inside of the waste liquid pipe 23.
Since the flow resistance is larger than air, one suction means
The suction force (negative pressure) supplied to the four openings 15 is
Most of the ink is in the opening 15 where the ink was sucked first.
Air is used to suck air from the
Evenly distributed to each waste liquid channel,
The suction force for sucking ink in the three openings 15 decreases.
As a result, time is required for suction.

This means, for example, that the tip has four legs.
Put all four ends of the branch pipe into the water
When suctioning water by supplying a negative pressure to the root,
Put three of the four tips of the manifold into the water
With the remaining one tip in the air, between branches
When suctioning water by supplying negative pressure to the root of
Is equivalent to the short time it takes for the former to suck water.
It is like. For this reason, it takes a long time to move to the next printing operation, and when the cap body 14 separates from the inkjet head 4 , the opening 15 is not sucked.
However, there is a problem that the remaining ink or the like flows down from the opening 15.

The present invention overcomes the problems of the prior art described above, and evenly sucks ink from each waste pipe with a simple structure without strictly considering the flow resistance balance of each waste pipe. It is an object of the present invention to provide a recovery device for an ink jet head which enables the above.

[0024]

According to a first aspect of the present invention, there is provided a recovery apparatus for an ink-jet head, comprising: For a plurality of inkjet heads, a cap body provided with a plurality of openings capable of covering the respective nozzle aggregates is disposed so as to be freely separated from each other, and the respective openings are provided for performing a recovery operation of the respective nozzle aggregates. A recovery unit for an ink jet head, comprising a plurality of waste liquid passages communicating with the nozzles and one suction means connected to each of the waste liquid flow passages and suctioning ink of each nozzle assembly flowing down to each of the openings. A part of each of the waste liquid flow paths is formed in the middle of each of the waste liquid flow paths, and is formed so that the flow path area gradually increases along the flow direction of the ink passing through each of the waste liquid flow paths. Toward the respective disposal passage during operation upwardly
It is characterized in that an ink storage unit capable of storing the ink that has passed through is provided.

[0025] Then, the recovery device of an ink jet head according to claim 2, in claim 1, wherein the ink reservoir is arranged closer towards the substantially vertical direction disposal passage which ink passes, the The waste liquid flow path is characterized in that the diameter of the waste liquid flow path is gradually increased upward in the vertical direction, which is the flow direction of the ink, so as to be able to store the ink.

[0026]

According to the ink jet head recovery device of the present invention, the ink flowing down from the nozzle of the ink flow path to each opening of the cap device during the recovery operation is provided.
By suction means, constituting Then together the portion of the waste drain path is formed in the middle of the waste drain path from the opening of the cap device
The ink reservoir the flow path area is formed so as to gradually increasing, it is possible to storing only appropriate amount of ink that passes upward, the flow resistance of each disposal passage, details uniform suction force Thus, the entire amount of ink can be reliably sucked from each opening through each waste liquid flow path.

Further, as described in claim 2, the ink passing through the ink storage section is stored as a storage film by the surface tension of the ink at the base of the enlarged diameter section of the flow passage, and is stored above the enlarged diameter section. Then, the storage film collapses beyond the surface tension of the ink, and a part is collected in the waste liquid tank through the reduced diameter portion, and the remainder flows down to the base of the enlarged diameter portion, and again the storage film is formed at the base of the enlarged diameter portion. It is stored.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The same or equivalent components as those of the above-described conventional device are denoted by the same reference numerals in the drawings.
The description is omitted.

FIG. 1 is a longitudinal sectional view of a main part of the present invention applied to a multi-color printer capable of performing color printing with four color inks, and FIG. 2 is a perspective view of the main part.

[0030] As shown in detail in FIGS. 1 and 2, in this embodiment, in the middle of the waste liquid tube 28 to form a waste channel, as well as constituting a part of the waste drain path, the waste stream Road
Flow path area gradually increases along the flow direction of ink passing through
Is formed so as to store ink passing through each of the waste liquid flow paths.
An ink storage section 31 that can be stored is provided. That is, in the cap body 14, each waste liquid pipe 28 communicating with the lower part of each opening 15 is connected to a horizontal part 29 penetrating to the back surface of the opening 15 of the cap body 14, and is connected to the horizontal part 29, It is formed by a vertical portion 30 of an appropriate length extending vertically upward on the back side of the main body 14. At the end of the vertical portion 30, an ink storing portion 31 capable of storing ink is continuously provided with the same axial direction. The ink storing section 31 is formed in a hollow shape having a substantially circular cross section so as to have a waste liquid flow path through which the ink flowing down to each opening 15 flows, and the vertical section 3 of the waste liquid pipe 28 is formed.
A base 32 of an appropriate length for fitting the end of the zero, a diameter-increasing portion 33 connected to the base 32 and formed so as to gradually increase the flow path area, and a diameter-reducing portion connected to the diameter expansion portion 33 Part 3
4 and connected from the reduced diameter portion 34, as shown in FIG.
And a connection end 35 connected to one suction means 24 via a relay section. Others are formed in the same manner as in the conventional example.

Next, the operation of the present embodiment having the above-described configuration will be described.

In order to perform the recovery operation of the ink jet head 4, first, the cap device 11 is moved to cover each nozzle assembly 5 of the ink jet head 4 with each opening 15 of the cap body 14. In this state, the pressurizing air passage 20 of the cap device 11 is connected to the pressurizing air passage 25 of the inkjet head 4. Then, the coating is completed and the detection signal of the covering completion is issued by the detecting means, not shown, to start the driving of the pressurizing means 21. Then, from the pressurizing means 21, the pressurizing air passage 2
0, 25 in the upper part of each ink cartridge 10
When the pressurized air as the pressurizing force is introduced and the ink in the ink cartridge 10 is pressurized, the bubbles in the ink flow paths 17 are ejected from the nozzles 6 together with the ink, and each of the openings 15 of the cap device 11 is opened. The ink is discharged for each color of the ink, and the flow of the ink in each ink flow path 17 can be made smooth. Then, the respective inks discharged to the respective openings 15 are then, for example , stored in the respective openings 15.
The inside is enlarged by an air release valve (not shown) through the communication passage 22.
The suction means 24 is driven while communicating with the
4 through each waste liquid pipe 28 brought into a negative pressure state by the driving of
The ink is stored in the waste liquid tank 36 via each ink storage unit 31.

When the suction of the ink in the opening 15 is completed, the last minute amount of ink is left in the ink storing section 31 as shown in FIG. That is, the state of the ink in the ink storage unit 31 is such that an appropriate amount of ink (state A), which has risen to the base 32 of the ink storage unit 31 due to the negative pressure serving as a suction force , blocks the waste liquid flow path of the ink.
Thereafter, the flow path area gradually increases along the ink flow direction.
Increasing the diameter of the waste flow path gradually increases become filmy to the limit value of the surface tension (state B) in the enlarged diameter portion 34 formed so as to, limit surface tension above the enlarged diameter portion 34 The crossing membrane is damaged (state C), a part of the ink storage unit 31 is lowered by gravity without being sucked (state D), and the base 32 of the ink storage unit 31 is returned.
(State A), and blocks the waste liquid flow path of the ink. FIG. 5 shows the relationship between these ink states and the suction force. And since this operation is repeated within a short time,
During the recovery operation, specifically, when the suction means 24 is driven
Ink will be stored in the ink storage unit 31,
Communicates with the opening 15 where the conventional ink was previously sucked
Flow resistance when passing through the inside of the waste liquid pipe 23
Suction air smaller than certain ink. That is,
The air (atmosphere) is sucked when the resistance is significantly reduced.
The suction force for sucking ink in the remaining openings 15 decreases.
It is possible to prevent the inconvenience of being generated.

As a result, the liquid flows down to all the openings 15.
Ink for a time necessary and sufficient to suck the ink
Of the waste liquid flow path communicating with the opening 15 to which the ink was sucked first.
The attractive force is linked to the opening 15 where the suction of the ink has not been completed.
It is possible to hold the suction force of the waste flow path through almost the same, the ink or the like containing bubbles that flow down into the opening 15, the interior of the waste drain path serving waste pipe 28 ink intermittently The same operation as described above is performed in the case of passing the target. In other words, in the ink storage unit 31
In the waste liquid flow path, the waste liquid flow path rises in the ink flow direction
A part of the last minute amount of ink returned to the base 32
While the base 32 of the ink storage unit 31 is closed,
Suction force of the waste liquid flow path communicating with the opening 15 that sucked the liquid
Communicate with the opening 15 where ink suction has not been completed.
The suction force of the waste liquid flow path flowing down to all the openings 15
The ink can be kept substantially the same for a time necessary and sufficient to suck the applied ink .

[0035] Therefore, according to this embodiment, the flow resistance in the interior of the waste liquid tube 28 provided on the cap body 14, details can be made substantially uniform suction force, the waste
Without strictly considering the balance of the suction force of the liquid tubes, the entire amount of ink flowing down to each opening 15 provided in each cap body 14 is efficiently and reliably stored in the waste liquid tank 36 within a predetermined time. be able to.

The suction force, the shape and size of the enlarged diameter portion 34 and the diameter of the enlarged diameter portion are determined after the ink rising from the base 32 at a desired position of the enlarged diameter portion 34 becomes a film due to surface tension. The film may be broken so that a portion of the raised ink returns to the base 32.

The present invention is not limited to the embodiment described above, and various modifications can be made as necessary.

For example, the opening 1 of the cap body 14
5 may be filled with a porous material such as sponge that can be impregnated with ink.

[0039]

As described above, according to the ink jet head recovery apparatus of the present invention, the ink flowing down to each opening provided in the cap main body can be simply stored in the vertical portion of each waste liquid pipe. Flow resistance of each waste liquid pipe , specifically,
Since the suction force can be made substantially uniform, it is possible to achieve a practical effect that the entire amount of ink that has flowed down to the respective openings in a short time can be reliably stored in the waste liquid tank.

[Brief description of the drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of an ink jet printer to which an ink jet head recovery device of the present invention is applied.

FIG. 2 is a perspective view of a main part showing an installation state of an ink storage unit.

FIG. 3 is an explanatory diagram showing a piping system of a main part of a suction part.

FIG. 4 is an explanatory diagram showing a state of ink passing through an ink storage unit.

FIG. 5 is a diagram illustrating a relationship between a state of ink passing through an ink storage unit and a suction force.

FIG. 6 is a perspective view showing a conventional ink jet printer.

FIG. 7 is a sectional view of a main part of FIG. 6;

FIG. 8 is an explanatory view showing a piping system of a main part of a conventional suction part.

[Explanation of symbols]

Reference Signs List 1 platen 4 inkjet head 5 nozzle assembly 6 nozzle 10 ink cartridge 11 cap device 14 cap body 15 opening 16 liner 17 ink flow path 20 pressurizing air passage 24 suction means 25 pressurizing air passage 28 waste liquid pipe 29 horizontal part 30 vertical Part 31 ink storage part 32 base part 33 enlarged diameter part 34 reduced diameter part 35 connection end part

Claims (2)

(57) [Scope of request for utility model registration] 1. An ink-jet head having a plurality of nozzle aggregates in which a plurality of ink flow paths each having a nozzle-shaped tip are arranged in an array, and a plurality of openings capable of covering the respective nozzle aggregates are provided. The plurality of waste liquid channels communicating with the respective openings and the respective waste liquid channels are connected to each of the waste liquid channels to perform the recovery operation of each of the nozzle assemblies, and the cap bodies are detachably arranged so as to be able to approach and separate the cap bodies. A recovery device for an ink jet head provided with one suction means for sucking ink of each nozzle assembly, wherein a part of each of the waste liquid flow paths is formed in the middle of each of the waste liquid flow paths; providing the ink storage portion with ink capable to retention of flow area along the flow direction through the respective disposal passage when formed recovery operation to incrementally upward of the ink passing through the flow path Ink jet head recovery device according to claim. 2. The ink storage section is disposed so that a waste liquid flow path through which ink passes is directed substantially vertically, and the waste liquid flow path is gradually upwardly directed vertically in the ink flow direction. 2. The ink-jet head recovery device according to claim 1, wherein the ink-jet head is formed so as to be able to store ink by expanding its diameter.