JP3543316B2 - Ink jet recording device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention includes an ink jet recording head that forms an image on a recording medium by discharging ink droplets from nozzle openings, and a flushing area for receiving the ink droplets when a flushing drive signal is supplied to the recording head. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus arranged on a movement path, and particularly to an ink jet recording apparatus capable of suppressing generation of unnecessary mist (fog ink) due to minute ink droplets during a flushing operation.
[0002]
[Prior art]
2. Description of the Related Art Ink jet recording apparatuses have been used in many types of printing including color printing in recent years because noise during printing is relatively small and small dots can be formed with high density. Such an ink jet recording apparatus includes an ink jet recording head that receives supply of ink from an ink cartridge, and a paper feeding unit that moves recording paper relative to the recording head, and records the recording head on a carriage. Recording is performed by ejecting ink droplets onto the recording paper while moving in the width direction of the paper. The carriage is equipped with a recording head that can eject black ink and each color ink of yellow, cyan, and magenta, and not only text printing with black ink, but also full-color printing by changing the ejection ratio of each ink. It is possible.
[0003]
In such an ink jet recording head, the ink pressurized in the pressure generating chamber is ejected from the nozzle opening as ink droplets onto the recording paper to perform printing, so that the ink viscosity increases due to evaporation of the solvent from the nozzle opening. In addition, there is a problem that printing failure occurs due to solidification of ink, adhesion of dust, and mixing of air bubbles. For this purpose, the ink jet recording apparatus is provided with capping means for sealing the nozzle openings of the recording head during non-printing.
[0004]
This capping means not only functions as a lid for preventing drying of the ink in the nozzle openings when printing is stopped, but also when the nozzle openings are clogged, the nozzle plate is sealed by the capping means, It also has a function of sucking ink from the nozzle openings by the negative pressure from the suction pump to eliminate clogging due to solidification of the ink in the nozzle openings and ink ejection failure due to air bubbles entering the ink flow path.
[0005]
The process of forcibly sucking and discharging the ink for eliminating the clogging of the recording head and the state of air bubbles mixed into the ink flow path is called a cleaning operation, and the printing is resumed after a long pause of the apparatus. This is executed when the user operates the cleaning switch in order to eliminate the deterioration of the quality of the recorded image, and an operation for discharging ink droplets by negative pressure is executed.
[0006]
It also has a function to apply a drive signal unrelated to printing to the printhead to eject ink droplets, which is called a flushing operation, and that the printhead has irregularities near the nozzle openings of the printhead due to wiping or the like during a cleaning operation. This operation is performed at regular intervals for the purpose of restoring the meniscus, or preventing clogging due to thickening of the ink at the nozzle opening where the amount of ink droplets ejected during printing is small.
[0007]
FIG. 5 shows an example of a conventional ink jet recording apparatus provided with the above-mentioned capping means and a flushing area for causing ink to be ejected at the time of flushing operation. In FIG. 5, reference numeral 51 denotes a carriage, which is configured to be reciprocated while being guided by a carriage shaft 54 supported by left and right frames 52 and 53 via a timing belt driven by a carriage motor (not shown). I have.
[0008]
An ink jet recording head 55 is mounted on the carriage 51 downward, and a black ink cartridge 56 for supplying ink to the recording head 55 and a color ink cartridge 57 are detachably mounted on the upper part thereof. Have been. Below the recording head 55, a paper guide member 58 is arranged corresponding to the scanning direction, and a recording paper 59 as a recording medium is placed on the paper guide member 58. The recording paper 59 is not shown. It is configured to be moved in a direction orthogonal to the scanning direction of the recording head 55 by a paper feeding unit.
[0009]
In the drawing, reference numeral 60 denotes capping means disposed in a non-printing area (home position), which moves upward when the recording head 55 moves directly upward to seal the nozzle forming surface of the recording head 55. It is configured to be able to. A suction pump 61 for applying a negative pressure to the internal space of the capping unit 60 is disposed below the capping unit 60.
[0010]
The capping means 60 functions as a lid for preventing the nozzle openings of the recording head 55 from drying during the suspension period of the recording apparatus, and also applies a drive signal unrelated to printing to the recording head to discharge ink droplets idle. It functions as an ink receiver at the time of the flushing operation to be performed, that is, a first flushing area, and also has a function as means for sucking ink by applying a negative pressure from the suction pump 61 to the recording head 55.
[0011]
A wiping member 62 composed of an elastic plate or the like made of rubber or the like is arranged near the capping unit 60. When the carriage 51 reciprocates toward the capping unit 60, the nozzle forming surface of the recording head 55 is formed. Is configured to perform a wiping operation of wiping.
[0012]
On the other hand, a second flushing area 63 is formed in the vicinity of the other end facing the capping means 60 via the central printing area. This second flushing area 63 is constituted by an opening 63 formed in the paper guide member 58. A waste liquid absorbing material 64 that absorbs and holds ink sucked and discharged from the internal space of the capping unit 60 by the pump 61 is disposed at the inner bottom of the opening hole 63. The absorbing material 64 is formed of the paper guide member. It is housed in an absorbing material storage case arranged along 58, that is, a waste liquid tank 65.
[0013]
[Problems to be solved by the invention]
By the way, in the above-described recording apparatus, flushing is periodically performed in order to prevent ejection failure due to thickening of ink at an unused nozzle during printing. In particular, in recent models, flushing of several tens of shots / 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. .
[0014]
The flushing may be performed in the capping means 60 as the first flushing area, or may be performed in the second flushing area 63 formed by the opening formed in the paper guide member 58. The reason for performing the flushing operation in the second flushing area 63 is to avoid the problem that the inside of the capping unit 60 is full of ink and the ink overflows when ink drops are ejected any more. ing.
[0015]
Further, in recent models, in order to increase the throughput, there is also provided a model that employs a sequence in which flushing is performed in a second flushing area opposed to the moving direction of the carriage without moving the recording head to the capping unit 60. ing. When the interval required for the regular flushing is short, when the paper size is large and it takes time to move the carriage, or when the printing direction and the timing at which the flushing is required do not mesh, the second flushing area is used. A sequence for performing the flushing is employed.
[0016]
When an opening hole is formed in the paper guide member 58 as shown in FIG. 5 as the second flushing area 63, the distance from the nozzle forming surface of the recording head 55 to the waste liquid absorbing material 64 is about several tens mm. Inevitably, the flying distance of the ink increases. For this reason, a part of the ink droplets ejected from the nozzle opening of the recording head becomes a mist due to air resistance before reaching the absorbing material 64 and floats as indicated by an arrow, thereby contaminating the surroundings. appear.
[0017]
The ink droplets ejected from the nozzle openings are not less charged, and are affected by the static electricity generated in the drive unit in the recording apparatus, and the air flow by the exhaust fan arranged to suppress the temperature rise in the apparatus, or the carriage. There is also a problem that the air may be accelerated by the air flow accompanying the movement of the recording device and contaminate the surroundings (outside) where the recording apparatus is arranged. In particular, in a recent printing apparatus in which the amount of each ink droplet is controlled to be as small as possible in order to realize high image quality, such a problem appears more remarkably.
[0018]
In order to prevent such a problem from occurring, a configuration in which a waste liquid absorbing material is disposed near the recording head is also conceivable. It is a reality that a large volume cannot be secured.
[0019]
The present invention has been made in view of the above-described problems, and in particular, to provide an ink jet recording apparatus capable of effectively suppressing the generation of mist floating as fine droplets during a flushing operation. 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.
[0020]
[Means for Solving the Problems]
An ink jet recording apparatus according to the present invention, which has been achieved to achieve the above-described object, is mounted on a carriage that moves in the width direction of recording paper, and forms an image on a recording medium by discharging ink droplets from nozzle openings. An ink jet recording apparatus, comprising: an ink jet recording head, wherein a flushing area for receiving ink droplets when a flushing drive signal is supplied to the recording head is arranged on a movement path of the recording head. An ink receiving unit for receiving ink droplets ejected from the recording head, wherein the ink receiving unit receives a plurality of ink droplets at a predetermined angle with respect to a flying direction of the ink droplets ejected from the recording head; The basic configuration is to dispose a plate member.
[0021]
In this case, the plurality of plate members are preferably arranged at substantially equal intervals at a predetermined angle, respectively, in a cylindrical portion that is opened in the flying direction of the ink droplets ejected from the recording head.
[0022]
In addition, the waste ink received by the plurality of plate members is formed integrally with the cylindrical body to form a cylindrical lead-out part that draws the waste ink downward in the direction of gravity, and is disposed below the lead-out part in the direction of gravity. It is preferable that the waste ink is discharged into the waste liquid tank. The angle between the flying direction of the ink droplet from the recording head and the direction of the plate surface of the plate member is in the range of 40 to 80 degrees, and preferably about 60 degrees.
[0023]
According to the ink jet recording apparatus according to the present invention configured as described above, the ink droplets flushed from the recording head in the flushing area include a plurality of plates arranged at a predetermined angle with respect to the flying direction of the ink droplets. Captured by any of the members. Then, the waste ink captured by each plate member is introduced into a waste liquid tank arranged below in the direction of gravity.
[0024]
If the angle between the flight direction of the ink droplet and the plate surface direction of the plate member is set small, the flying distance of the ink droplet can be reduced, and the degree of mist generation can be reduced. The angle of impact on the plate surface is close to an orthogonal state, and a problem arises that mist is generated by the rebound of ink droplets. Further, when the angle between the flight direction of the ink droplet and the direction of the plate surface of the plate member is set to be large, the flying distance of the ink droplet increases on average, and the degree of mist generation increases.
[0025]
Therefore, it is desirable that the angle between the flying direction of the ink droplet and the direction of the plate surface of the plate member is about 60 degrees. As a result, the degree of generation of the mist can be reduced, and the inside and outside of the apparatus can be contaminated. It is possible to solve the problem of causing.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an ink jet recording apparatus according to the present invention will be described based on an embodiment shown in the drawings. 1 to 3 show a configuration of a large-sized ink jet recording apparatus (hereinafter, also referred to as a printer) directly installed on a floor, and FIG. 1 shows an external perspective view of the printer. 2 shows a front view of the internal configuration of the printer. Further, FIG. 3 is a longitudinal sectional view of a state in which a flushing area portion described later in FIG. 2 is broken.
[0027]
In this printer, a paper feed unit 1, a printing unit 2, and a discharge stack unit 3 are arranged in an upper, middle, and lower positional relationship. A sheet transport path from the sheet feeding section 1 to the sheet discharge stack section 3 via the printing section 2 is formed substantially straight from the obliquely upper back side to the obliquely lower front side. As shown in FIGS. 2 and 3, the paper feed unit 1 is configured so that a long roll paper 4 as a recording medium having a paper width of, for example, 40 inches or more can be disposed, and can be removed at the time of replacement. The paper feed unit 1 is configured to have a height suitable for performing the work of replacing the roll paper 4 with the worker standing.
[0028]
In the embodiment, as shown in FIG. 1, the front surface of the roll paper 4 attached to the paper feed unit 1 can be covered with a roll paper cover 5 that can be opened and closed. When the cover 5 is closed, the upper surface of the cover 5, the printing unit 2, and a discharge guide 6, which will be described later, are substantially flush with each other. Is configured to be able to supply and discharge paper.
[0029]
As shown in FIG. 2, the sheet feeding section 1 further includes a pair of spindle receivers 8a and 8b below a pair of spindle receivers 7a and 7b. These spindle receivers are respectively mounted on a pair of left and right frames 9 in the printer body. Then, both ends of the two long spindles 7 and 8 to which the roll papers 4 and 4 are respectively mounted are laid horizontally while being placed between the spindle receivers 7a and 7b and between the spindle receivers 8a and 8b. I have.
[0030]
As can be understood from FIGS. 1 and 2, the two spindles 7, 8 are inclined obliquely up and down with respect to each other so that the upper spindle 7 is slightly rearward with respect to a worker standing in front of the apparatus. Are placed in a relationship. Each of the roll papers 4 is configured to be conveyed along a paper conveyance path that is formed substantially linearly obliquely up and down toward the entrance of the discharge stack unit 3 via the printing unit 2.
[0031]
As shown in FIG. 2, a guide rod 10 attached to the printing unit 2 so as to be horizontal between the left and right frames 9 and 9 is arranged. The carriage 11 has a recording head 12 mounted thereon. Below the scanning area of the recording head 12, a flat paper ejection guide 6 which forms a part of the paper conveyance path is formed.
[0032]
The discharge stack 3 is a portion for receiving printed sheets, and the discharge stack 3 is formed of a stack cloth 13 made of a foldable cloth sheet. Then, as shown in FIG. 3, the printed paper is guided to the first receiving portion 15 almost directly below the printing section 2 by the paper discharge switching lever 14, or on the front floor of the printer body (not shown). The state in which the sheet is guided to a second receiving portion that is temporarily formed on the front side by unfolding the stack cloth 13 is configured.
[0033]
In this embodiment, when the printed paper is guided to the first receiving portion 15, the trailing edge 6a of the paper discharge guide 6 formed below the printing portion 2 and the paper discharge switching lever are provided. 14, an opening 16 is formed between the stack cloth 13 and the upper end edge 13a of the stack cloth 13 protruding on the sheet transport path.
[0034]
When the printed paper is guided to the second receiving portion, the upper edge 13a of the stack cloth 13 is retracted backward from the paper transport path by the paper discharge switching lever 14, and the stack cloth fixing lever 17 is moved forward. The stack cloth 13 can be deployed to the front side of the printer main body by engaging the hook 18 to which the leading end of the stack cloth 13 is fixed to the front end of the fixing lever 17.
[0035]
As shown in FIG. 2, one end of the traveling area of the recording head 12 mounted on the carriage 11 is formed as a non-printing area (home position), and a capping unit 21 is disposed in this non-printing area. The nozzle forming surface of the recording head 12 is mounted on the carriage 11 in a state in which the recording head 12 is slightly inclined from the vertical direction as described later. It is arranged so that the nozzle forming surface of the head 12 can be sealed. A suction pump 22 for applying a negative pressure to the internal space of the capping unit 21 is disposed below the capping unit 21.
[0036]
As described above, the capping unit 21 functions as a lid for preventing the nozzle openings of the recording head 12 from drying during the suspension period of the recording apparatus, and also causes the negative pressure from the suction pump 22 to act on the recording head 12, It also has a function as a head cleaning means for sucking ink. The waste ink sucked by the suction pump 22 is discharged to a first waste liquid tank 23, and is absorbed by a waste liquid absorbing material 23a accommodated in the tank.
[0037]
On the other hand, a first flushing area 25 is formed on the movement path of the recording head 12 adjacent to the capping means 21, and the first flushing area 25 has an ink receiving unit described in detail in FIG. The waste ink collected by the ink receiving unit 27 is discharged to a first waste liquid tank 23 disposed below in the direction of gravity, and discharged to a waste liquid absorbing material 23a housed in the tank. It is configured to be absorbed.
[0038]
Also, a second flushing area 26 is formed at the other end facing the capping means 21 via the central print area. Also in the second flushing area 26, an ink receiving unit 27 described in detail in FIG. 4 is disposed, and the waste ink collected by the ink receiving unit 27 is disposed in the second flushing area 26 in the second direction. It is configured to be discharged to the waste liquid tank 28 and absorbed by the waste liquid absorbing material 28a housed in the tank.
[0039]
The first and second flushing regions are provided with a flushing sequence that is appropriately selected and used in accordance with, for example, a paper width to be printed, thereby reducing the throughput without reducing the throughput. It is configured so that printing reliability can be ensured.
[0040]
FIGS. 4A and 4B show the configuration of the ink receiving unit 27 disposed in the first and second flushing areas. FIG. 4A is a front view thereof, and FIG. 4B is a front view thereof. , A longitudinal sectional view of which is broken at substantially the center. The ink receiving unit 27 includes a cylindrical body 31 opened in the direction in which ink droplets fly from the recording head 12 and a cylindrical lead-out part 32 for leading waste ink to the waste liquid tank 23 or 28. And are integrally formed. The ink receiving unit 27 is attached to the recording apparatus such that the axis 32c of the lead-out portion 32 is substantially vertical.
[0041]
A plurality of plate members 33 that receive the ink droplets at a predetermined angle with respect to the flight direction of the ink droplets discharged from the recording head are arranged in the cylindrical body portion 31. In this embodiment, four plate members 33 are provided, which are arranged at substantially equal intervals in the cylindrical body portion 31 and are respectively parallel to the axis of the cylindrical body portion 31 due to the restriction of die cutting. It is formed so that it becomes.
[0042]
In the embodiment, the angle between the flying direction of the ink droplets ejected from the recording head and the direction of the plate surface of each plate member 33 is set to approximately 60 degrees. In other words, as shown in FIG. 4B, the angle θ between the extension of the nozzle forming surface of the recording head 12 and the axis of the cylindrical body 31 is 60 degrees.
[0043]
As a result, the ink droplets ejected from the recording head collide with the plate surface of each plate member 33 at an angle of approximately 30 degrees and are captured, as indicated by arrows in FIG. The waste ink captured by each plate member 33 is led out to the waste liquid tank 23 or 28 disposed below the gravity direction through the lead-out portion 32.
[0044]
In this embodiment, as described above, the angle between the flying direction of the ink droplet from the recording head and the plate surface direction of the plate member is 60 degrees, but this is in the range of 40 degrees to 80 degrees. It is preferable to set. That is, if the angle is less than 40 degrees, the flight distance of the ink droplet can be reduced, but the angle of impact of the ink droplet on the plate surface approaches an orthogonal state. The surface bounces off, thereby causing a problem of generating mist.
[0045]
On the other hand, when the angle exceeds 80 degrees, the flying distance of the ink droplet increases on average, so that the degree of mist generation increases. In particular, as indicated by the arrow in FIG. 4B, when the ink droplets ejected from the recording head pass immediately before being captured by the front plate member 33, the flight distance becomes extremely long. Therefore, the degree of generation of mist increases.
[0046]
Moreover, when the angle between the flying direction of the ink droplet and the plate surface direction of the plate member exceeds 80 degrees in a mounted state of the recording head in which the ink droplet flies in a state close to the horizontal direction as in the embodiment. In this case, there is also a problem that the axis of the cylindrical portion 31 approaches a horizontal state, and the flow of waste ink in the cylindrical portion 31 also deteriorates.
[0047]
Further, even when the angle is increased, by increasing the number of plate members 33, it is possible to reduce the flying distance of the ink droplets. The interval between the plate members becomes small, and problems such as a decrease in ink sweeping and a hindrance to operability of maintenance occur. For the above reasons, it is preferable to set the angle in the range of 40 degrees to 80 degrees.
[0048]
In the above-described embodiment, four plate members are provided, but the number may be appropriately selected according to the size of the cylindrical body forming the plate member. Although the above description is based on an example in which the present invention is applied to a particularly large recording apparatus as shown in FIGS. 1 to 3, the present invention is applied only to such a specific recording apparatus. It is needless to say that the same operation and effect can be obtained even when applied to another ink jet recording apparatus.
[0049]
【The invention's effect】
As apparent from the above description, according to the ink jet recording apparatus of the present invention, the ink receiving unit that receives the ink droplets ejected from the recording head is arranged in the flushing area, and the ink receiving unit ejects the ink droplets from the recording head. Since the angle between the flying direction of the ink droplet to be formed and the plate surface direction is, for example, about 60 degrees, a plurality of plate members are arranged. Captured by the plate member. Thus, it is possible to reduce the probability that some of the ink droplets become mist and float, and solve the problem that the inside and outside of the apparatus are contaminated by the generation of mist.
[Brief description of the drawings]
FIG. 1 is an external perspective view of an ink jet recording apparatus to which the present invention is applied.
FIG. 2 is a front view schematically showing an internal configuration of the recording apparatus shown in FIG.
FIG. 3 is a longitudinal sectional view showing a state in which the flashing area is broken in the recording apparatus shown in FIG. 2;
FIGS. 4A and 4B are a front view and a vertical sectional view showing a configuration of an ink receiving unit arranged in a flushing area.
FIG. 5 is a sectional view showing an example of a conventional ink jet recording apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Paper feed part 2 Printing part 3 Paper discharge stack part 4 Roll paper 10 Guide rod 11 Carriage 12 Recording head 12a Nozzle formation surface 12b Nozzle row 21 Capping means 22 Suction pumps 23 and 28 Waste liquid tanks 12a and 28a Waste liquid absorbents 25 and 26 Flushing area 27 Ink receiving unit 31 Cylindrical part 32 Outgoing part 33 Plate member

Claims (4)

An ink jet recording head that is mounted on a carriage that moves in the width direction of the recording paper and ejects ink droplets from nozzle openings to form an image on a recording medium, and ink that is supplied when a flushing drive signal is supplied to the recording head An ink jet recording apparatus in which a flushing area for receiving droplets is arranged on a movement path of the recording head,
An ink receiving unit that receives ink droplets ejected from the recording head is arranged in the flushing area, and the ink receiving unit has an ink droplet at a predetermined angle with respect to the flight direction of the ink droplet ejected from the recording head. An ink jet recording apparatus, wherein a plurality of plate members for receiving the ink are arranged. The ink jet type according to claim 1, wherein the plurality of plate members are disposed at substantially equal intervals at the predetermined angle, respectively, in a cylindrical portion opened in a flying direction of an ink droplet ejected from a recording head. Recording device. The waste ink received by the plurality of plate members is formed integrally with the cylindrical body to form a cylindrical lead-out portion for leading the waste ink downward in the direction of gravity, and the waste liquid disposed below the lead-out portion in the direction of gravity. 3. The ink jet recording apparatus according to claim 2, wherein the waste ink is discharged into a tank. 4. The ink jet recording apparatus according to claim 1, wherein an angle between a flight direction of the ink droplet from the recording head and a plate surface direction of the plate member is in a range of 40 to 80 degrees. 5. .

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