JP2000177146A - Ink-jet type recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict generation of an unnecessary mist (fog-like ink) by minute ink drops at a flashing operation. SOLUTION: An ink-receiving unit 17 for receiving ink drops discharged from a recording head 12 is arranged to a flashing area of the recording head. A plurality of sheet members 33 are set to the ink-receiving unit so that a direction of a sheet face to a flying direction of ink drops discharged from the recording head is, for example, approximately 60 deg.. In this constitution, ink drops by flashing are caught by any of the sheet members in a relatively short flight distance. Accordingly, the probability that part of the ink drops float as mist is lowered and the problem of contaminating the inside and outside the apparatus because of generation of mist is solved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises an ink jet recording head for forming an image on a recording medium by discharging ink droplets from nozzle openings, and receives ink droplets when a flushing drive signal is supplied to the recording head. An ink jet recording apparatus in which a flushing area is arranged on a movement path of the recording head, and in particular, at the time of a flushing operation, an unnecessary mist (fog-like ink) caused by minute ink droplets can be suppressed. It relates to a recording device.

[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 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.

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 capping means for sealing the nozzle openings of the recording head during non-printing.

The capping means not only functions as a lid for preventing the ink from being dried at the nozzle openings when printing is stopped, but also seals the nozzle plate when the nozzle openings are clogged. It also has a function of sucking ink from the nozzle opening by the negative pressure from the suction pump and eliminating clogging due to solidification of the ink in the nozzle opening and ink ejection failure due to air bubbles entering the ink flow path. .

The forcible suction / discharge process of ink for eliminating the clogging of the recording head and the incorporation of air bubbles into the ink flow path is called a cleaning operation. Is restarted, or when the user operates the cleaning switch to eliminate the deterioration of the quality of the recorded image, and performs an operation of discharging ink droplets by negative pressure.

The recording head also has a function of applying a drive signal unrelated to printing to eject ink droplets. This function is called a flushing operation, and the nozzle opening of the recording head is performed by wiping or the like during a cleaning operation. This operation is performed at regular intervals in order to recover irregular meniscus in the vicinity or to prevent clogging due to thickening of ink at a nozzle opening that discharges a small amount of ink droplets during printing.

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, and left and right frames 52, 52 are provided via a timing belt driven by a carriage motor (not shown).
It is configured to be reciprocated while being guided by a carriage shaft 54 supported by 53.

An ink jet type 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 side thereof. Loaded as possible. 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 the paper feeding means.

In the drawing, reference numeral 60 denotes capping means arranged in a non-printing area (home position). When the recording head 55 moves directly upward, it moves upward to seal the nozzle forming surface of the recording head 55. It is configured to be able to stop. Below the capping means 60, a suction pump 61 for applying a negative pressure to the internal space of the capping means 60 is arranged.

The capping means 60 functions as a lid for preventing the nozzle openings of the recording head 55 from drying during the idle period of the recording apparatus, and also applies a driving signal unrelated to printing to the recording head to apply ink droplets. Functions as a first flushing area during a flushing operation for causing the ink to be ejected, and the suction pump 61
A negative pressure from the nozzle acts on the recording head 55 to also function as a means for sucking ink.

A wiping member 62 composed of an elastic plate or the like made of rubber or the like is disposed near the capping means 60. When the carriage 51 reciprocates to the capping means 60 side, the wiping member 62 The wiping operation for wiping the nozzle forming surface is performed.

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. The second flushing area 63 is constituted by an opening hole 63 formed in the paper guide member 58. And this opening hole 63
A waste liquid absorbing material 64 that absorbs and holds the ink sucked and discharged by the pump 61 in the inner space of the capping means 60 is disposed at the inner bottom of the capping means 60. The absorbing material 64 is disposed along the paper guide member 58. Is stored in the absorbent storage case, that is, the waste liquid tank 65.

[0013]

Incidentally, the above-mentioned recording apparatus is constructed so that flushing is periodically performed in order to prevent ejection failure due to thickening of ink at unused nozzles during printing. Have been. Especially on recent models, on average every few seconds dozens of shots / 1
Flushing about the nozzle is performed. 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 60 as the first flushing area, or may be performed in the second flushing area 63 formed by the opening hole formed in the paper guide member 58. is there. 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 becomes full of ink and the ink overflows when ink drops are ejected any more. ing.

Further, in recent models, in order to increase the throughput, the recording head is not moved to the capping means 60, and the recording head is moved to the second position 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. A sequence for performing the flushing is employed.

As the second flushing region 63, FIG.
In the case where the opening hole is formed in the paper guide member 58 as shown in (1), the distance from the nozzle forming surface of the recording head 55 to the waste liquid absorbing material 64 is about several tens mm, and the flying distance of the ink does not increase. I can't escape. 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.

The ink droplets ejected from the nozzle openings are charged to a considerable extent, and are affected by static electricity generated in a drive section in the recording apparatus and an air flow generated by an exhaust fan arranged to suppress a rise in temperature in the apparatus. Alternatively, there may be a problem that the air is accelerated due to the movement of the carriage and the surrounding area (outside) where the recording apparatus is disposed is contaminated. 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.

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. In fact, it is not possible to secure a sufficient volume.

The present invention has been made in view of the above-mentioned problems, and particularly, in a flushing operation,
It is an object of the present invention to provide an ink jet recording apparatus capable of effectively suppressing the generation of mist floating as fine droplets, thereby achieving high commercial value of the ink jet recording apparatus without contaminating the inside and outside of the apparatus. It is intended to provide a recording device.

[0020]

In order to achieve the above-mentioned object, an ink jet recording apparatus according to the present invention is mounted on a carriage which moves in the width direction of a recording sheet, and drops ink from a nozzle opening. An ink jet recording apparatus comprising an ink jet recording head for forming an image on a recording medium by discharging, 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. In the flushing area, an ink receiving unit that receives the ink droplets ejected from the recording head is disposed, and the ink receiving unit has a predetermined direction with respect to the flight direction of the ink droplets ejected from the recording head. The basic configuration is to arrange multiple plate members that receive ink droplets at an angle.

In this case, the plurality of plate members are preferably arranged at substantially equal intervals at a predetermined angle, respectively, in a cylindrical portion opened in the flying direction of ink droplets ejected from the recording head. You.

Further, a cylindrical lead-out portion for leading the waste ink received by the plurality of plate members downward in the direction of gravity is formed integrally with the cylindrical portion, and a lower portion of the lead portion in the direction of gravity is formed. It is preferable that the waste ink is led out into a waste liquid tank arranged in 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, preferably about 60 degrees.

According to the ink jet recording apparatus of the present invention having the above structure, the ink droplets flushed from the recording head in the flushing area are
The ink droplets are captured by any one of a plurality of plate members arranged at a predetermined angle with respect to the flight direction of the ink droplets. Then, the waste ink captured by each plate member is introduced into a waste liquid tank arranged below the gravity direction.

If the angle formed between the direction of flight of the ink droplet and the direction of the plate surface 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. In this case, the angle at which the ink droplet collides with the plate surface becomes close to an orthogonal state, and a problem arises in that the ink droplet bounces to generate mist. In addition, if the angle between the flight direction of the ink droplet and the plate surface direction of the plate member is set to be large, the flight distance of the ink droplet increases on average, and the degree of mist generation increases.

Therefore, it is desirable that the angle between the flying direction of the ink droplets 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. The problem of contaminating inside and outside can be solved.

[0026]

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. 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. FIG. 3 is a longitudinal sectional view showing a state in which a flushing area portion described later in FIG. 2 is broken.

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 paper transport path from the paper supply unit 1 to the paper discharge stack unit 3 via the printing unit 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 supply 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 exchanging the roll paper 4 with the worker standing.

In the embodiment, as shown in FIG. 1, the front surface of the roll paper 4 mounted on the paper feed unit 1 is covered by a roll paper cover 5 which can be opened and closed. When the cover 5 is closed, the upper surface of the cover 5, the printing unit 2, and a paper ejection guide 6, which will be described later, are substantially flush with each other.
It is configured to be able to supply and discharge a separate sheet of paper or rigid cardboard.

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, 9 in the printer body. And
Both ends of two long spindles 7, 8 on which roll papers 4, 4 are mounted, respectively,
It is laid horizontally between a and 7b and between 8a and 8b.

As can be understood from FIGS. 1 and 2, the two spindles 7 and 8 are mutually moved so that the relatively upper spindle 7 is slightly rearward with respect to the worker standing in front of the apparatus. They are arranged diagonally up and down. 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.

As shown in FIG. 2, a guide rod 10 is provided in the printing unit 2 so as to be horizontal between the left and right frames 9 and 9 so that the guide rod 10 can be moved left and right on the guide rod 10. , A carriage 11 is mounted thereon, and a recording head 12 is mounted on the carriage 11.
Below the scanning area of the recording head 12, a flat paper ejection guide 6 forming a part of the paper conveyance path is formed.

The paper discharge stack 3 is a portion for receiving printed paper. The paper discharge stack 3 is a stack cloth 13 whose paper receiving surface is made of a foldable cloth sheet.
It is formed with. Then, as shown in FIG. 3, the printed paper is transferred to the printing unit 2 by the paper discharge switching lever 14.
Of the stack cloth 1 on the front floor of the printer body (not shown).
3 is developed so that the sheet can be guided to a second receiving portion that is temporarily formed on the front side.

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
Between the upper edge 13a of the stack cloth 13 protruding on the paper transport path by the paper discharge switching lever 14.
6 is formed so as to be ensured.

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 discharge switching lever 14, and the stack cloth fixing lever 17 is moved. Is pulled out to the front side, and the hook 18 to which the leading end of the stack cloth 13 is fixed is engaged with the front end of the fixing lever 17, so that the stack cloth 13 can be deployed to the front side of the printer body. ing.

As shown in FIG. 2, one end of the traveling area of the recording head 12 mounted on the carriage 11 is formed in a non-printing area (home position), and a capping means 21 is disposed in the non-printing area. I have. The nozzle forming surface of the recording head 12 is mounted on the carriage 11 in a state where it 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.

As described above, the capping means 21 functions as a lid for preventing the nozzle opening of the recording head 12 from drying during the period when the recording apparatus is stopped, and also acts on the recording head 12 by applying a negative pressure from the suction pump 22. Let me
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 housed in the tank.

On the other hand, a first flushing area 25 is formed on the moving path of the recording head 12 adjacent to the capping means 21, and this first flushing area 25 will be described in detail with reference to FIG. An ink receiving unit 27 is provided, and the ink receiving unit 27
The collected waste ink is discharged to a first waste liquid tank 23 disposed below in the direction of gravity, and is absorbed by a waste liquid absorbing material 23a accommodated in the tank.

Further, a second flushing area 26 is formed at the other end opposite to the capping means 21 via the central printing area. In the second flushing area 26 as well, 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 lower part in the direction of gravity. It is configured to be discharged to the waste liquid tank 28 and absorbed by the waste liquid absorbing material 28a accommodated in the tank.

The first and second flushing areas are provided with a flushing sequence which is appropriately selected and used in accordance with, for example, a paper width to be printed, thereby reducing throughput. Further, the configuration is such that the reliability of printing by flushing can be ensured.

FIGS. 4A and 4B show the structure of the ink receiving unit 27 disposed in the first and second flushing areas. FIG. 4A is a front view, and FIG. In the front view, a vertical cross-sectional view substantially broken at the center is shown. The ink receiving unit 27 includes a cylindrical portion 31 opened in the direction in which ink droplets fly from the recording head 12 and a cylindrical lead-out portion 32 for leading waste ink to the waste liquid tank 23 or 28. And are integrally formed. And this ink receiving unit 27
It is attached to the recording device such that the axis 32c of the lead-out portion 32 is substantially vertical.

A plurality of plate members 33 for receiving the ink droplets at a predetermined angle with respect to the flight direction of the ink droplets ejected from the recording head are arranged in the cylindrical 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.

In the embodiment, each plate member 3
3 is the flight direction of the ink droplet ejected from the recording head,
The angle formed with the plate surface direction is set to approximately 60 degrees. In other words, as shown in FIG.
The angle θ between the extension line of the nozzle forming surface of No. 2 and the axis of the cylindrical body portion 31 is 60 degrees.

As a result, the ink droplets ejected from the recording head are applied to each plate member 3 as shown by the arrow in FIG.
No. 3 collides with the plate surface at an angle of approximately 30 degrees and is captured. 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.

In this embodiment, as described above, the angle formed between the direction in which ink droplets fly from the recording head and the direction of the plate surface of the plate member is 60 degrees.
It is preferable to set the angle in the range of 0 to 80 degrees. That is, if the angle is less than 40 degrees, the flying 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.

On the other hand, when the angle exceeds 80 degrees, the flying distance of the ink droplet becomes large on average, so that the degree of mist generation becomes large. 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 plate member 33 in front, the flight distance becomes extremely long. Therefore, the degree of mist generation is increased.

Further, when the recording head is mounted such that the ink droplet flies in a state close to the horizontal direction as in the embodiment, the angle between the direction of the ink droplet and the direction of the plate surface of the plate member is 80 degrees. In the case where it exceeds, the axis of the cylindrical portion 31 becomes close to a horizontal state, and the problem that the flow of waste ink in the cylindrical portion 31 also deteriorates occurs.

Further, even when the angle is increased, the flying distance of the ink droplet can be reduced by increasing the number of the plate members 33, but it is not possible to increase the number of the plate members 33. In addition, the interval between the plate members becomes small, and problems such as a decrease in ink sweeping and a hindrance to maintenance operability occur. For the above reasons, it is preferable to set the angle in the range of 40 degrees to 80 degrees.

Note that, in the above-described embodiment, 4
Although a plurality of plate members are provided, the number can 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.
The present invention can be applied not only to such a specific printing apparatus but also to other ink jet printing apparatuses to obtain the same effect.

[0049]

As is apparent from the above description, according to the ink jet recording apparatus of the present invention, the ink receiving unit for receiving the ink droplets ejected from the recording head is arranged in the flushing area. Since a plurality of plate members having an angle formed between the flight direction of the ink droplets ejected from the recording head and the plate surface direction is, for example, about 60 degrees are arranged, the ink droplets generated by flushing have a relatively short flying distance. In, it is captured by any of the plate members. Thus, it is possible to reduce the probability that a part of the ink droplet becomes a mist and float, and solve the problem that the inside and the outside of the apparatus are contaminated by the generation of the 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 region 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 pump 23,28 Waste liquid tank 12a, 28a Waste liquid absorbent 25,26 Flushing area 27 Ink receiving unit 31 Cylindrical part 32 Lead-out part 33 Plate member

Claims (4)

[Claims] An ink jet recording head is mounted on a carriage that moves in the width direction of a recording sheet and ejects ink droplets from nozzle openings to form an image on a recording medium. A flushing drive signal is sent to the recording head. An ink jet recording apparatus in which a flushing area for receiving ink droplets when supplied is arranged on a movement path of the recording head, wherein the flushing area includes an ink receiving unit for receiving ink droplets ejected from the recording head. Placed,
The ink jet recording apparatus according to claim 1, wherein the ink receiving unit includes a plurality of plate members that receive the ink droplets at a predetermined angle with respect to a flying direction of the ink droplets discharged from the recording head. 2. The printing apparatus according to claim 1, wherein the plurality of plate members are arranged at substantially equal intervals at the predetermined angle in a cylindrical body opened in a flying direction of ink droplets ejected from a recording head. 3. The ink jet recording apparatus according to claim 1. 3. A cylindrical lead portion for discharging waste ink received by the plurality of plate members downward in the direction of gravity is formed integrally with the cylindrical body portion, and the waste ink is drawn downward in the direction of gravity of the lead portion. 3. The ink jet recording apparatus according to claim 2, wherein the waste ink is discharged into a waste liquid tank disposed in the ink jet recording apparatus. 4. An apparatus according to claim 1, wherein an angle formed between a direction in which ink droplets fly from the recording head and a surface direction of the plate member is in the range of 40 to 80 degrees. Inkjet recording device.