JP2001080092A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that ink drops ejected by flushing operation float as mist to contaminate the surroundings. SOLUTION: A housing-like ink collecting unit 21 is disposed in a flushing region provided at the end of the moving passage of a carriage 1 and the unit 21 is provided with an opening 22 for passing ink drops being delivered from the nozzle opening of a recording head at the time of flushing operation. Even if ink drops introduced into the unit 21 produce mist in the inner space, the mist falls down to the bottom of the unit or adheres to the inner wall face thereof and can be collected surely. Consequently, contamination of the ink jet recorder due to generation of mist can be prevented on the inside and outside of the recorder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes an ink jet recording head for forming an image on a recording sheet by discharging ink droplets from nozzle openings, and receives a discharge ink when a flushing drive signal is supplied to the recording head. The present invention relates to an ink jet recording apparatus in which a flushing area is arranged on a moving path of a recording head, and more particularly to an ink jet recording apparatus capable of effectively collecting unnecessary mist (fog ink) due to minute ink droplets generated during a flushing operation. About.

[0002]

2. Description of the Related Art Ink jet recording apparatuses have been used in many types of printing including color printing in recent years, since noise at the time of printing is relatively small and small dots can be formed at a high density. Such an ink jet recording apparatus is generally mounted on a carriage and scans in the width direction of recording paper, and an ink jet recording head;
A paper feeder is provided for moving the recording paper in a direction perpendicular to the scanning direction of the recording head, and recording is performed by discharging ink droplets from the recording head onto the recording paper in accordance with print data.

[0003] By constructing such that black ink and each color ink of yellow, cyan and magenta can be continuously supplied to the recording head,
Not only text printing with black ink but also full-color printing is possible by changing the discharge ratio of each color ink.

In such an ink jet recording head, the ink pressurized in the pressure generating chamber is ejected as ink droplets from a nozzle opening onto recording paper to perform printing. There is a problem that printing failure occurs due to an increase in viscosity, solidification of the ink, adhesion of dust, and mixing of air bubbles. For this purpose, the ink jet recording apparatus is provided with a capping means for sealing the nozzle openings of the recording head during non-printing and a wiping member for wiping and cleaning the nozzle forming surface as required.

[0005] The capping means not only functions as a lid for preventing drying of ink in the nozzle openings of the recording head when printing is stopped, but also when the nozzle openings are clogged, the nozzle forming surface is formed by the capping means. And a function to eliminate clogging due to solidification of ink at the nozzle opening and ink ejection failure due to air bubbles entering the ink flow path by sucking and discharging ink from the nozzle opening by negative pressure from the suction pump. It also has.

[0006] Forcible suction and discharge of ink for eliminating the clogging of the recording head and the mixing of air bubbles into the ink flow path is called a cleaning operation. This is executed when printing is resumed or when the user operates the cleaning switch after recognizing that the quality of the printed image has deteriorated, and is formed of an elastic plate such as rubber after sucking and discharging ink from the recording head. An operation of wiping the nozzle forming surface of the recording head by the wiping member is involved.

The recording head also has a function of applying a drive signal irrelevant to printing to eject ink droplets. This function is called a flushing operation, and a wiping operation by a wiping member at the time of a cleaning operation is carried out. To recover uneven meniscus generated near the nozzle opening,
In addition, this operation is performed at regular intervals for the purpose of preventing clogging due to thickening of ink at a nozzle opening where ejection of ink droplets is small during printing.

FIG. 8 shows an example of a conventional ink jet type recording apparatus configured to discharge ink droplets to a flushing area sandwiching the above-described capping means and printing area during a flushing operation. In FIG. 8, reference numeral 1 denotes a carriage. The carriage 1 is guided by a guide shaft 4 supported by left and right frames 2 and 3 via a timing belt driven by a carriage motor (not shown) to reciprocate in the axial direction. It is configured to be.

An ink jet recording head 5 is mounted on the carriage 1 downward, and a black ink cartridge 6 for supplying ink to the recording head 5 and a color ink cartridge 7 are detachably mounted on an upper portion thereof. It is installed. A paper guide member 8 is disposed below the recording head 5 corresponding to the scanning direction, and the recording paper 9 placed on the paper guide member 8 is moved by a paper feeding means (not shown). It is configured to be able to sequentially transport in a direction orthogonal to the scanning direction.

In the drawing, reference numeral 10 denotes capping means arranged in a non-printing area (home position). When the recording head 5 moves directly upward, it moves upward to seal the nozzle forming surface of the recording head 5. It is configured to be able to stop. Below the capping means 10, a suction pump 11 for applying a negative pressure to the internal space of the capping means 10 is arranged.

The capping means 10 functions as a lid for preventing the nozzle openings of the recording head 5 from drying during the idle period of the recording apparatus, and also applies a drive signal unrelated to printing to the recording head to apply ink droplets. Functioning as a first flushing area during a flushing operation, ie, a first flushing area, in which a negative pressure from the suction pump 11 is applied to the recording head 5 to suction and discharge ink. Has both.

In the vicinity of the capping means 10, a wiping member 12 composed of an elastic plate or the like made of rubber or the like is arranged. When the carriage 1 reciprocates toward the capping means 10, the recording head 5 is moved. The wiping operation for wiping the nozzle forming surface is performed.

On the other hand, a second flushing area 13 is formed in the vicinity of the other end facing the capping means 10 via the central printing area. The second flushing area 13 is constituted by an opening hole formed so as to penetrate the paper guide member 8. A part of a waste liquid absorber 14 for absorbing and retaining ink discharged from the capping means 10 via the pump 11 is disposed at the inner bottom of the opening forming the flushing region 13. 14 is an absorbent storage case arranged along the paper guide member 8, that is, the waste liquid tank 1
It is contained within 5.

[0014]

As described above, in such a recording apparatus, flushing is periodically performed in order to prevent a discharge failure due to ink thickening at an unused nozzle during printing. It is configured to: In particular, in recent models, flushing of about several tens of shots / one nozzle is performed on average every few seconds. This flushing may be performed to prevent color mixing at the timing after the cleaning operation, or at the timing at the start of printing, and may periodically discharge thousands to tens of thousands of shots from each nozzle during printing. .

The flushing may be performed in the capping means 10 as the first flushing area, or may be performed in the second flushing area 13 by the opening formed in the paper guide member 8. This includes the reason that when the flushing is executed only in the capping unit 10, the inside of the capping unit 10 becomes full of ink and the problem that the ink overflows is avoided.

Further, in recent models, in order to increase the throughput, the recording head is not moved to the capping means 10 but is moved in the second direction facing the moving direction of the carriage.
There is also provided a model that employs a sequence for executing flushing in the flushing area. Also, when the interval required for regular flushing is short, when the paper size is large and it takes time to move the carriage, and when the printing direction and the timing at which flushing is required do not mesh, the second flushing area is used. Flushing is performed.

As the second flushing area 13, FIG.
In the case where the opening hole is formed in the paper guide member 8 as shown in (1), the distance from the nozzle forming surface of the recording head 5 to the waste liquid absorbing material 14 is about several tens mm, and the flying distance of the ink is not increased. I can't escape. For this reason, some of the ink droplets ejected from the nozzle openings of the recording head
Before arriving at 4, the mist (fog ink) is formed by air resistance and floats as indicated by the arrow, causing a problem that the recording paper and the inside and outside of the apparatus are contaminated.

In order to prevent such a problem from occurring, it is conceivable to arrange a waste liquid absorbing material at a position close to the recording head. However, in general, a mechanism such as a paper feed roller is provided in a portion of the carriage traveling area opposed to the head. In fact, it is not possible to secure a sufficient volume.

Therefore, as shown in FIG. 9, an inclined wall 16 is provided in an opening hole in the second flushing area 13 where the mist is liable to occur, as shown in FIG. There is also provided a recording device provided with means for preventing the formation of minute mist. According to such a configuration, the ink droplet ejected from the nozzle opening by the flushing reaches the inclined wall 16 at a relatively short distance, is captured by the inclined wall 16 and is guided to the waste liquid absorbent 14, so that the ink droplet is discharged. The degree of floating as mist due to air resistance can be reduced.

However, the ink droplets discharged from the nozzle openings are charged to a certain extent, and are affected by the static electricity generated in the drive unit in the recording apparatus, and the air is exhausted by an exhaust fan arranged to suppress the temperature rise in the apparatus. The flow is accelerated by the flow or the air flow accompanying the movement of the carriage, and as described above, the problem that the recording paper and the inside and outside of the recording apparatus are contaminated remains. In particular, in a recent printing apparatus in which the amount of each ink droplet is controlled as small as possible in order to realize high image quality, such a problem appears more remarkably.

The present invention has been made in view of the above-described problems, and provides an ink jet recording apparatus capable of effectively collecting ink mist floating as fine droplets, particularly during a flushing operation. Accordingly, it is an object of the present invention to provide an ink jet recording apparatus having a high commercial value without contaminating the inside and outside of the apparatus.

[0022]

In order to achieve the above-mentioned object, an ink jet recording apparatus according to the present invention is mounted on a carriage which scans a recording sheet in a width direction and ejects ink droplets from nozzle openings. An ink jet recording apparatus comprising an ink jet recording head for forming an image on a recording sheet, and a flushing area for receiving an ink droplet when a flushing drive signal is supplied to the recording head is arranged on a moving path of the recording head. So,
A receiving opening through which ink droplets ejected from the nozzle opening of the recording head can pass by the flushing operation is formed, and through the receiving opening, an internal space sufficiently larger than the receiving opening is used as an ink collecting and storing section. It is configured to include the formed housing-shaped ink recovery unit.

In this case, it is preferable that a waste liquid absorbing material is disposed at the lower bottom of the ink recovery unit.
The receiving opening is preferably configured to have an opening area slightly larger than or smaller than the nozzle arrangement area of the recording head.

Further, the receiving opening is arranged on one side of the ink collecting unit, and an air outlet is arranged on the other side of the ink collecting unit. It is preferable that the flow path is configured to be formed in the internal space of the ink recovery unit.

Further, in a preferred embodiment,
A plate-like body that protrudes into the internal space of the ink recovery unit and increases the surface area of the internal space is arranged. In this case, it is possible to adopt a configuration in which the plate-shaped members are arranged so as to face each other in the internal space, and a constricted portion is formed in the air flow path by opposing edges of each plate-shaped member.
In addition, a configuration in which the plate-shaped members are arranged so as to be alternated in the internal space, and an air flow path bent in a meandering shape by each plate-shaped member may be adopted.

Further, the receiving opening is preferably constituted by a plurality of groove-shaped holes which are opened at positions facing the respective nozzle rows of the recording head which are preferably located in the flushing area. Further, a configuration in which a plurality of strip-shaped guide ribs are arranged so as to be in parallel with each other in the receiving opening so as to open at a position facing each nozzle row of the recording head located in the flushing area is preferable. Available.

According to the ink jet recording apparatus constructed as described above, the ink droplets ejected from the nozzle openings of the recording head in the flushing area are immediately sent from the receiving opening formed in the ink recovery unit into the ink collecting unit. Is introduced into the interior space. Therefore, even if the introduced ink droplet changes in the internal space as a mist, it is attached to the inner wall surface of the unit and collected. And, by adopting a configuration in which the waste liquid absorbing material is arranged at the lower bottom portion of the ink collecting unit, the waste liquid of the ink adhered and collected on the inner wall surface of the unit flows down in the direction of gravity and is impregnated with the waste liquid absorbing material It is securely held.

In this case, by forming an air discharge port on the other end side of the unit having the reception opening formed therein, the ink drop from the reception opening to the discharge port is formed by the action of the ink droplet flying toward the reception opening. An air flow is formed inside. By disposing a plate-like body that increases the surface area of the air flow path in the unit, the ink mist flowing with the air is reliably captured by the plate-like body or the like, and the ink can be effectively collected.

Further, the receiving opening is formed by a plurality of grooved holes, or a plurality of strip-shaped guide ribs are arranged so as to be parallel to each other.
The problem that the ink mist in the unit flows backward from the receiving opening due to the slight negative pressure due to the movement of the carriage can be reduced.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ink jet recording apparatus according to the present invention will be described based on an embodiment shown in the drawings. FIG. 1 shows the first embodiment in cross section. In FIG. 1, parts corresponding to the respective parts in FIG. 8 already described are denoted by the same reference numerals, and therefore, detailed description thereof will be omitted. As shown in FIG.
The waste liquid tank 15 disposed below the paper guide member 8 is configured to be approximately half the size in the moving direction of the carriage as compared with the conventional example shown in FIG. It is located in the right half of the device.

On the other hand, in the left half below the paper guide member 8, an ink recovery unit indicated by reference numeral 21 is arranged. The unit 21 has a substantially rectangular parallelepiped housing, and a receiving opening 22 through which ink droplets ejected from the nozzle opening of the recording head 5 can pass by a flushing operation is formed upward. ing. Further, a sheet-like waste liquid absorbing material 23 is disposed at a lower bottom portion of a housing constituting the unit 21.

As shown in an enlarged manner in FIG. 2, the receiving opening 22 forms a second flushing area for receiving an ink droplet when a flushing drive signal is supplied to the recording head 5. The opening 22 is disposed immediately below the recording head 5 located in the second flushing area, with a slight gap therebetween. The opening area of the receiving opening 22 is configured to be slightly larger or smaller than the area of the nozzles in the recording head.

With this configuration, most of the ink droplets due to the flushing ejected from the nozzle openings of the recording head 5 are moved from the opening 22 to the unit 2 as indicated by the broken lines.
1 is introduced into the ink collection and storage section. Most of the ejected ink droplets reach the sheet-like waste liquid absorbing member 23 disposed at the lower bottom of the unit 21 and are absorbed thereby.

Further, the fine droplets of the ink which have become mist before reaching the waste liquid absorbing material 23 are sealed in the internal space of the housing constituting the unit 21. Naturally descends or adheres to the inner wall surface of the unit 21 and is captured.
Flows in the direction of gravity on the inner wall surface of the slab, and is absorbed and held by the waste liquid absorber 23. Therefore, according to the above-described configuration, it is possible to solve the problem that the mist generated by the flushing drifts in the apparatus and contaminates the recording paper and the inside and outside of the apparatus.

As can be understood from the operation described above,
The opening area of the receiving opening 22 is preferably formed to be small enough not to hinder the flight of ink droplets ejected by flushing, as exemplified by the imaginary line 22a in FIG. 2, for example. Thereby, the degree to which the mist in the unit 21 leaks to the outside can be reduced.

Next, FIG. 3 is a sectional view showing another embodiment of the ink recovery unit 21 in the same manner. In the configuration shown in FIG. 3, an air outlet 24 is formed on the other side of the housing-shaped ink recovery unit 21, and the other configuration is the same as the configuration shown in FIG. According to the configuration shown in FIG. 3, a small airflow indicated by an arrow A is generated in a direction from the receiving opening 22 to the discharge port 24 due to the flying of the ink droplet by the flushing.
That is, the air flow path A is formed in the internal space of the unit 21.

With this configuration, the backflow of the ink mist from the receiving opening 22 formed in the unit 21 can be effectively suppressed. The mist floating in the internal space of the unit 21 is discharged at a very
And in the course of this movement, it naturally descends to the surface of the waste liquid absorbing material 23 or the unit 21
Is adhered to the inner wall surface of the unit 21 and is captured, flows on the inner wall surface of the unit 21 in the direction of gravity, and is absorbed and held by the waste liquid absorbent 23. Thereby, the air discharged from the discharge port 24 includes:
It is made to the extent that mist is hardly mixed.

FIG. 4 shows an embodiment in which the configuration shown in FIG. 3 is further improved, and is also shown in a sectional view. In the configuration shown in FIG.
And a plate-like body 25 that protrudes into the internal space of the air passage and increases the surface area of the air flow path. In the embodiment shown in FIG. 4, each plate 25
Each of the plate-like members 25 is arranged so as to oppose each other from above and below, and a constricted portion 26 is formed in the air flow path by opposing edges 25 a of each plate-like member 25.

According to the unit 21 configured as described above, the ink mist floating in the internal space of the unit moves in the direction of the discharge port 24 at a very small speed, and in the process of moving, the respective plate-like members 25 move. Therefore, it passes through the constricted portion 26 formed by the above, thereby increasing the chance of contact with each plate-like body 25. Therefore, the ink mist adheres to and is trapped on the inner wall surface of each of the plate-like bodies 25 or the units 21, and the trapping efficiency of the ink mist can be increased.

In the embodiment shown in FIG. 4, the waste liquid absorbing material 23 is arranged only at the lower bottom of the chamber formed immediately below the receiving opening 22. It is preferable to arrange so as to be disposed at the lower bottom of the remaining two chambers.

FIG. 5 shows still another embodiment, which is also shown in a sectional view. In the configuration shown in FIG. 5, the respective plate-like members 25 projecting into the internal space of the ink recovery unit 21 are respectively arranged so as to be staggered in the internal space from above and below, and are meandered by the respective plate-like members 25. The configuration is such that a bent air flow path is formed.

According to this configuration, the length of the air flow path from the receiving opening 22 to the exhaust port 24 is substantially long and bent, so that the ink mist can be removed from the respective plate-like members 25 or The ink mist is captured by being attached to the inner wall surface of the unit 21, and the efficiency of capturing the ink mist can be further improved as compared with the embodiment shown in FIG.

In the embodiment shown in FIG. 5, the waste liquid absorbing material 23 is disposed only at the lower bottom of the chamber formed immediately below the receiving opening 22. It is preferable to arrange so as to be disposed at the lower bottom of the remaining two chambers.

FIG. 6 is a sectional view showing a preferred form of the receiving opening 22 formed in the unit 21. As shown in FIG. As shown in FIG.
Reference numeral 2 denotes a plurality of groove-shaped holes 22b opened at positions facing the respective nozzle rows of the recording head 5 located in the flushing area.
It consists of. The recording head 5 shown in the figure has a form having four nozzle rows for respectively ejecting black, yellow, cyan, and magenta inks, for example, and four grooves are formed at positions facing each nozzle row. The holes 22b are respectively arranged.

With this configuration, the ink droplets ejected from each nozzle row of the recording head 5 by the flushing operation are:
As shown in FIG. 6, they are respectively introduced into the internal space of the unit 21 through the groove-shaped holes 22b. That is, the embodiment shown in the drawing has a structure in which a minimum opening area through which ink droplets ejected from each nozzle row can fly and pass is ensured. In response to this, the degree of backflow of the ink mist in the unit 21 from the receiving opening 22 can be significantly reduced.

FIG. 7 is a sectional view showing another preferred embodiment of the receiving opening 22 formed in the unit 21. As shown in FIG. As shown in FIG. 7, the receiving opening 22 is opened at a position facing each nozzle row of the recording head 5 located in the flushing area.
A plurality of strip-shaped guide ribs 27 are arranged so as to be parallel to each other.

With this configuration, the ink droplets ejected from each nozzle row of the recording head 5 by the flushing operation are:
As shown in FIG. 7, the ink droplets are introduced into the internal space of the unit 21 through the space between the strip-shaped guide ribs 27 arranged in parallel with each other in the flying direction of the ink droplets. That is, in the embodiment shown in the drawing, an opening through which ink droplets ejected from each nozzle row can fly and pass is formed by each guide rib 27 arranged in the vertical direction. With this configuration, for example, the degree of backflow of the ink mist in the unit 21 from the receiving opening 22 can be similarly reduced by receiving a slight negative pressure due to the movement of the carriage 1.

[0048]

As is apparent from the above description, according to the ink jet recording apparatus of the present invention, a receiving opening through which ink droplets ejected from nozzle openings of a recording head can pass by a flushing operation is formed, and A housing-shaped ink recovery unit having an internal space through the receiving opening as an ink collecting and storing unit is provided, so that ink droplets ejected from the recording head in response to a flushing drive signal can be immediately received and opened. It can be introduced into the internal space of the unit from the part. Therefore, even if the ink droplets introduced into the unit are changed into a mist in the internal space, the ink droplets can drop naturally on the lower bottom of the unit or adhere to the inner wall surface and can be reliably collected. Can solve the problem that the inside and outside of the device are contaminated by the occurrence of the occurrence.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of an ink jet recording apparatus according to the present invention.

FIG. 2 is an enlarged longitudinal sectional view of an ink recovery unit in the recording apparatus shown in FIG.

FIG. 3 is a longitudinal sectional view showing another embodiment of the ink recovery unit.

FIG. 4 is a longitudinal sectional view showing still another embodiment of the ink recovery unit.

FIG. 5 is a longitudinal sectional view showing still another embodiment of the ink recovery unit.

FIG. 6 is a longitudinal sectional view showing a preferred form of a receiving opening in the ink recovery unit.

FIG. 7 is a longitudinal sectional view showing another preferred form of the receiving opening in the ink recovery unit.

FIG. 8 is a longitudinal sectional view showing a conventional ink jet recording apparatus.

FIG. 9 is a longitudinal sectional view showing an example of a flushing area in a conventional ink jet recording apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Carriage 4 Guide shaft 5 Recording head 6 Black ink cartridge 7 Color ink cartridge 8 Paper guide member 9 Recording paper 10 Capping means 11 Suction pump 12 Wiping member 15 Waste liquid tank 21 Ink recovery unit 22 Receiving opening 22b Groove hole 23 Waste liquid absorption Material 24 Discharge port 25 Plate 25a Edge 26 Constriction 27 Strip guide rib A Air flow path

Claims (9)

[Claims] An ink jet recording head mounted on a carriage that scans in the width direction of the recording paper and ejects ink droplets from nozzle openings to form an image on the recording paper; and a flushing drive signal is sent to the recording head. What is claimed is: 1. An ink jet recording apparatus, comprising: a flushing area for receiving an ink droplet when supplied, on a movement path of the recording head, wherein a receiving opening through which an ink droplet ejected from a nozzle opening of the recording head by a flushing operation can pass. An ink jet recording apparatus comprising: a housing-shaped ink recovery unit in which an internal space sufficiently larger than the reception opening is formed as an ink recovery storage through the reception opening. 2. The ink jet recording apparatus according to claim 1, wherein a waste liquid absorbing material is disposed at a lower bottom of said ink recovery unit. 3. The ink jet recording apparatus according to claim 1, wherein an opening area of the receiving opening is slightly larger than or smaller than a nozzle arrangement area of the ink jet recording head. 4. The air from the receiving opening to the discharge port by arranging the receiving opening on one side of the ink recovery unit and arranging an air outlet on the other side of the ink recovery unit. 4. The ink jet recording apparatus according to claim 1, wherein the flow path is formed in an internal space of the ink recovery unit. 5. The ink jet recording apparatus according to claim 4, wherein a plate-like body projecting into an internal space of the ink recovery unit and increasing a surface area of the air flow path is arranged. 6. The plate-like body according to claim 5, wherein the plate-like bodies are arranged so as to face each other in the internal space, and a constricted portion is formed in the air flow path by opposing edges of each plate-like body. The ink-jet recording apparatus as described in the above. 7. The ink jet type according to claim 5, wherein the plate-like bodies are arranged so as to be staggered in the internal space, and each plate-like body forms a meandering air flow path. Recording device. 8. The printing apparatus according to claim 1, wherein the receiving opening is formed by a plurality of groove-shaped holes that are opened at positions facing the respective nozzle rows of the recording head located in a flushing area. The ink-jet recording apparatus as described in the above. 9. A plurality of strip-shaped guide ribs are arranged in the receiving opening so as to be opened at a position facing each nozzle row of the recording head located in a flushing area so as to be parallel to each other. The ink jet recording apparatus according to any one of claims 1 to 7, comprising: