JP2001219559A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove ink adhering to a wiper member at wiping operation. SOLUTION: A nozzle plate 21 is provided with a nozzle array 29 having a plurality of nozzle openings 25 for ejecting ink drops. A plurality of pressure generating chambers 26 communicating with the plurality of nozzle openings 25 are formed on a channel substrate 22 disposed on the rear surface 21b side of the nozzle plate 21. A plurality of pressure generating means 7 for ejecting ink drops from the plurality of nozzle openings 25 by pressurizing ink in the plurality of pressure generating chambers 26 are also provided. A recess 30 for capturing ink is made with a specified depth from the surface 21a of the nozzle plate 21 in order to suction remove ink adhering to a wiping means 11 when ink remaining on the surface 21a of the nozzle plate 21 is wiped off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head for ejecting ink droplets from nozzle openings based on print data and an ink jet recording apparatus provided with the recording head.

[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.

[0003] Such an ink jet recording apparatus is
Generally, an ink jet recording head mounted on a carriage and moving in the width direction of the recording paper, and a paper feeding unit for moving the recording paper in a direction orthogonal to the scanning direction of the recording head are provided, and recording is performed in accordance with print data. Recording is performed by discharging ink droplets from a head onto recording paper. Then, on the carriage, for example, a recording head capable of discharging ink of each color of black, yellow, cyan, magenta is mounted, and not only text printing with black ink, but also full color printing by changing the discharge 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. Poor printing may occur due to an increase in viscosity, solidification of the ink, adhesion of dust, and 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, and wiping means having a wiper member for cleaning the nozzle forming surface as necessary. .

The capping means not only functions as a lid for preventing the ink from being dried at the nozzle opening, but also seals the nozzle forming surface by the capping means when the nozzle opening is clogged. In addition, it has a function of sucking and discharging ink from the nozzle opening by the negative pressure from the suction pump to eliminate clogging of the nozzle opening and ink ejection failure due to air bubbles entering the ink flow path.

[0006] Forcible suction and discharge of ink for eliminating clogging of the recording head and mixing of air bubbles into the ink flow path is called a cleaning operation. If you want to resume printing later,
This operation is performed when the user recognizes a defect in the printing state and operates the cleaning switch.After the ink is sucked and discharged from the recording head, the nozzle forming surface of the recording head is wiped by a wiper member made of an elastic plate such as rubber. An operation of wiping is performed.

[0007] The recording head also has a function of applying a drive signal unrelated to printing to eject ink droplets, which is called a flushing operation. This operation recovers an irregular meniscus generated near the nozzle opening of the head by a wiping operation (wiping operation) by the wiper member at the time of the cleaning operation, or slightly sucks the ink discharged to the capping means at the nozzle opening at the time of the cleaning operation. This is an operation that is executed at regular intervals in order to eliminate the occurrence of color mixing due to the above, and to prevent clogging due to thickening of ink at the nozzle opening where ink droplets are less discharged during printing.

[0008]

However, in the conventional ink jet recording apparatus, the ink adhered to the wiper member during the previous wiping operation (wiping operation) is solidified as it is and remains on the wiper member. For this reason, a sufficient wiping function cannot be obtained in the subsequent wiping operation, and the solidified ink is rubbed against the surface of the nozzle plate (the nozzle forming surface), so that the surface of the nozzle plate is worn. There is.

In addition, the ink captured by the wiper member in the wiping operation is scattered by the expansion operation of the wiper member when the wiper member separates from the surface of the nozzle plate, so that the scattered ink causes contamination inside the apparatus. There's a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an ink jet recording head capable of removing ink attached to a wiper member during a wiping operation. An object of the present invention is to provide an ink jet recording apparatus provided with the recording head.

[0011]

In order to solve the above-mentioned problems, an ink jet recording head according to the present invention has a nozzle array comprising a plurality of nozzle openings for discharging ink droplets, and includes a nozzle including a front surface and a back surface. A plate and a plurality of pressure generating chambers communicating with the plurality of nozzle openings are formed, and a flow path substrate disposed on the back surface side of the nozzle plate, and pressurizes ink inside the plurality of pressure generating chambers. A plurality of pressure generating means for ejecting ink droplets from the plurality of nozzle openings, and a case member disposed on a side opposite to the nozzle plate with respect to the flow path substrate, wherein the surface of the nozzle plate is provided. In order to absorb the ink adhering to the wiping means when the remaining ink is wiped by the wiping means and to remove the ink from the wiping means, Wherein the ink trapping recesses are formed across from the surface of the nozzle plate to a part of the case member.

Preferably, the ink catching concave portion is formed at a position deviated to at least one side in the scanning direction of the recording head when viewed from the nozzle row forming region.

Preferably, the concave portion for ink capture is formed at each position deviated to both sides in the scanning direction of the recording head when viewed from the nozzle row forming region.

Preferably, a plurality of the nozzle rows are provided, and the ink catching recess is formed at least between the nozzle rows.

Preferably, the ink catching recess is formed as an elongated groove parallel to the nozzle row.

Preferably, the elongated groove is formed continuously along a direction parallel to the nozzle row.

Preferably, the elongated grooves are formed in a plurality of parallel rows.

Preferably, the elongated groove is formed so as to be intermittent along a direction parallel to the nozzle row.

Preferably, the elongated grooves are formed in a plurality of parallel rows and have the same intermittent pattern between the rows.

Preferably, the elongated grooves are formed in a plurality of parallel rows, and the intermittent patterns of the rows are alternated.

[0021] Preferably, the ink catching recess is formed as a plurality of holes arranged along a direction parallel to the nozzle row.

Preferably, the plurality of holes are formed in a plurality of parallel rows, and the arrangement pattern of the holes in the rows is the same.

Preferably, the plurality of holes are formed in a plurality of parallel rows, and the arrangement patterns of the holes in the rows are alternated.

Preferably, the ink catching concave portion extends in a direction parallel to the nozzle row and beyond a length corresponding to the nozzle row.

Preferably, the ink catching recess is located inside a sealing area on the surface of the nozzle plate which is sealed by capping means when sucking and discharging ink from the nozzle opening. .

An ink jet recording apparatus according to the present invention includes any one of the ink jet recording heads described above, and a flexible wiper member that slides on the surface of the nozzle plate. Wiping means for wiping the remaining ink, sealing the surface of the nozzle plate to form a sealed space, and applying a negative pressure to the sealed space to remove ink from the nozzle opening and the ink capturing recess. And capping means for sucking and discharging.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ink jet recording apparatus according to one embodiment of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a carriage. The carriage 1 is configured to be reciprocated in the axial direction of a platen 5 while being guided by a guide member 4 via a timing belt 3 driven by a carriage motor 2. .

An ink jet recording head (not shown in FIG. 1) is mounted on the side of the carriage 1 facing the recording paper 6, and a black ink storage section for supplying ink to the recording head is provided above the ink jet recording head. An ink cartridge 7 and a color ink cartridge 8 are detachably mounted.

A capping means 9 is disposed at a home position (right side in the drawing) which is a non-printing area of the recording apparatus. The capping means 9 moves the recording head mounted on the carriage 1 to the home position. Sometimes, the nozzle forming surface of the recording head can be sealed. And below the capping means 9,
A pump unit 10 for applying a negative pressure to the internal space of the capping means 9 is arranged.

The capping means 9 functions as a lid for preventing the nozzle openings of the recording head from drying during the idle period of the recording apparatus, and also applies a drive signal unrelated to printing to the recording head to empty ink drops. It functions as an ink receiver at the time of a flushing operation for discharging, and also has a function as a cleaning unit for suctioning and discharging ink by applying a negative pressure from each suction pump constituting the pump unit 10 to the recording head.

In the vicinity of the printing area side of the capping means 9, a wiping means 11 provided with an elastic plate such as rubber is arranged so as to be able to advance and retreat in a horizontal direction with respect to the movement locus of the recording head, for example. Carriage 1
When reciprocating to the capping means 9 side, the nozzle forming surface of the recording head can be wiped as necessary.

FIG. 2 is a perspective view showing an ink jet recording head according to this embodiment, and FIG.
-It is a longitudinal section along the A line. As shown in FIGS. 2 and 3, the recording head 20 includes a nozzle member 21, a flow path substrate 22, and an elastic plate 23 that are sequentially stacked, and a case member 24.
It is configured to be fixed.

The nozzle plate 21 is formed with two nozzle rows 29 each composed of a plurality of nozzle openings 25 for discharging ink droplets.
Is formed so as to extend from the front surface 21a to the back surface 21b.

The flow path substrate 22 has a plurality of nozzle openings 25.
Are formed with a plurality of pressure generating chambers 26 communicating with the pressure generating chambers. A plurality of piezoelectric vibrators (pressure generating means) 27 are arranged corresponding to each of the plurality of pressure generating chambers 26. The piezoelectric vibrators 27 are housed in the case member 24 and are fixed by the fixing plate 28 to the case member 24. It is fixed to. Then, by applying a voltage having a predetermined waveform to the piezoelectric vibrator 27, the ink inside the pressure generating chamber 26 is pressurized and the ink droplet can be ejected from the nozzle opening 25.

Further, in the present embodiment, an ink catching recess 30 is formed over a predetermined depth from the surface 21 a of the nozzle plate 21, and the ink catching recess 30 is formed of a plurality of nozzle openings 25. Row 2
It comprises four elongated grooves formed continuously along a direction parallel to 9.

The ink catching recess 30 is formed at each position deviated to both sides in the scanning direction D of the recording head 20 when viewed from the formation region R1 of the nozzle row 29, and further corresponds to the nozzle row 29. It extends beyond the length of the range. Further, the ink capturing recess 30 is provided in the nozzle plate 2.
1 is formed from the surface 21a to a part of the case member 24. The ink capturing concave portion 30 is located inside the sealing region R2 on the surface 21a of the nozzle plate 21 which is sealed by the capping means when sucking and discharging ink from the nozzle opening 25.

Here, the configuration of the ink catching concave portion in the present invention is not limited to that shown in FIGS. 2 and 3, and for example, like the ink catching concave portion 31 shown in FIG. Can be formed intermittently along a direction parallel to the direction, and the intermittent pattern between the rows of the ink capturing concave portions 31 can be made the same. Further, like the ink capturing concave portion 32 shown in FIG. 5, the ink capturing concave portions 32 may be provided in three rows on each side, and the intermittent pattern between the rows may be alternated.

The ink catching recess 33 shown in FIG.
As described above, it is also possible to form a plurality of holes arranged along a direction parallel to the nozzle row 29. Hole 33
Can be staggered between the rows of holes as shown in FIG. 6, or they can be the same.

Further, the ink catching recess 34 shown in FIG.
As described above, the ink capturing concave portion 34 can be formed between the nozzle rows 29 as well. In this case, the ink capturing concave portion 34 may be the intermittent groove shown in FIGS. 4 and 5, or may be the hole shown in FIG.

Next, the operation of the present embodiment will be described with reference to FIGS.

In FIG. 8, reference numeral 11 denotes wiping means.
The wiping means 11 is a flexible wiper member 11a.
It has. FIG. 8A shows a state before the wiping operation by the wiping unit 11 is started, and the ink I is attached to the surface 21 a of the nozzle plate 21. Further, the ink I adhered to the previous wiping operation remains on the wiper member 11a. From this state, the recording head 20 is moved in the direction of the wiping unit 11 (to the left in the drawing).

Then, as shown in FIG. 8B, the ink I adhering to the wiper member 11a is transferred to the ink catching recess 3 disposed in front of the recording head 20 in the traveling direction.
Removed by 0. At this time, the wiper member 11a
If the ink I attached to the ink is in a liquid state, the ink I is adsorbed and held in the ink capturing recess 30, and if the ink I is solidified, the solidified ink I It is scraped off by the corners.

Next, as shown in FIG. 8C, when the recording head 20 further moves to the left in the drawing, the wiper member 11a slides on the surface 21a of the nozzle plate 21 while bending, and the nozzle plate 21 Of the ink I adhering to the surface 21a of the substrate. Here, since the wiper member 11a has been refreshed in the step shown in FIG. 8B, the ink I on the surface 21a of the nozzle plate 21 can be sufficiently wiped.

Next, as shown in FIG. 8D, when the recording head 20 further moves to the left in the figure, the ink I captured by the wiper member 11a is released.
The ink is absorbed by the ink catching recess 30 disposed rearward in the traveling direction of the ink. The ink I absorbed in the ink capturing recess 30 is held in the ink capturing recess 30 by capillary force.

Next, as shown in FIG. 8E, when the recording head 20 further moves leftward in the figure, the wiper member 11a moves away from the surface 21a of the nozzle plate 21.
At this time, the bent wiper member 11a expands, but in the process shown in FIG.
Since the ink I has already been removed from a, the ink I will not be scattered by the extending operation of the wiper member 11a.

Next, as shown in FIG. 9 (a), the surface 21a of the nozzle plate 21 is sealed by the cap member 51 of the capping means 50 to form a closed space, and the closed space is made negative pressure. As a result, the ink is sucked and discharged from the nozzle opening 25 to perform cleaning, and at the same time, the ink I held inside the ink capturing recess 30 is removed.
Is sucked and discharged. Then, as shown in FIG. 9B, the ink I in the ink capturing concave portion 30 is removed, and the inside of the ink capturing concave portion 30 is cleaned.

As described above, according to the present embodiment, since the ink catching recess 30 is formed over a predetermined depth from the surface 21a of the nozzle plate 21, the ink I attached to the wiper member 11a is removed. It is possible to absorb and remove the wiping member 30 and prevent the wiping function of the wiping means 11 from being deteriorated due to the adhesion of the ink. It is possible to prevent the surface 21a of the nozzle plate 21 from being worn by the ink.

Further, by forming ink catching recesses 30 at positions deviated to both sides in the scanning direction of the recording head 20 when viewed from the formation region R1 of the nozzle row 29, the surface 21a of the nozzle plate 21 is wiped. When the member 11a slides, first, the ink is removed from the wiper member 11a in front of the nozzle row 29 and refreshed, and the refreshed wiper member 11a removes the ink from the nozzle row 29 and the surrounding area. The removed ink is absorbed and removed by the ink capturing recess 30 located behind the nozzle row 29.
Therefore, the ink on the surface 21a of the nozzle plate 21 can be reliably removed.

Further, as shown in FIG. 7, by forming an ink catching recess 30 between the nozzle rows 29, the surface 21a of the nozzle plate 21 is
When 1a slides, the nozzle row 29 of the plurality of nozzle rows 29 which is located in the forward direction of the recording head 20 and the ink around the nozzle row 29 are wiped off by the wiper member 11a, and then between the nozzle rows 29. The ink attached to the wiper member 11a is not carried to the adjacent nozzle row 29 having a different color of the ink to be ejected, thereby preventing color mixture at the time of the wiping operation. be able to.

Further, since the recording head 20 is formed by laminating a plurality of members made of different materials, even when a thermal stress is generated in the recording head 20 due to a difference in the coefficient of thermal expansion of each member. Since the thermal stress is relieved by the ink capturing concave portion 30, it is possible to prevent the recording head 20 from being destroyed due to the thermal stress.

[0051]

As described above, according to the present invention, since the ink catching recess is formed over a predetermined depth from the surface of the nozzle plate, the ink adhering to the wiping means is absorbed and removed by the ink catching recess. Therefore, it is possible to prevent a decrease in the wiping function of the wiping unit due to the adhesion of the ink, to always secure a sufficient wiping function, and to reduce the surface of the nozzle plate by the ink solidified on the wiping unit. Wear can be prevented.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing a schematic configuration of an ink jet recording head according to one embodiment of the present invention.

FIG. 3 is a sectional view taken along the line AA of FIG. 2;

FIG. 4 is a perspective view showing a first modification of the ink jet recording head according to the embodiment of the present invention.

FIG. 5 is a perspective view showing a second modification of the ink jet recording head according to the embodiment of the present invention.

FIG. 6 is a perspective view showing a third modification of the ink jet recording head according to the embodiment of the present invention.

FIG. 7 is a perspective view showing a fourth modification of the ink jet recording head according to the embodiment of the present invention.

FIGS. 8A to 8E are diagrams illustrating a process of wiping ink in an ink jet recording apparatus according to an embodiment of the present invention in the order of steps (a) to (e).

FIGS. 9A and 9B are diagrams showing a process of removing ink from the ink capturing concave portion following the ink wiping process shown in FIGS.

[Explanation of symbols]

 Reference Signs List 9 capping unit 11 wiping unit 11a wiper member 20 ink jet recording head 21 nozzle plate 21a nozzle plate surface 21b nozzle plate back surface 22 flow path substrate 23 elastic plate 24 case member 25 nozzle opening 26 pressure generating chamber 27 piezoelectric vibrator (pressure) Generation means) 29 Nozzle row 30, 31, 32, 33, 34 Ink capturing concave part R1 Nozzle row formation area R2 Sealing area by capping means

Claims (16)

[Claims] A nozzle plate having a plurality of nozzle openings for discharging ink droplets, the nozzle plate including a front surface and a back surface, and a plurality of pressure generating chambers communicating with the plurality of nozzle openings are formed; A flow path substrate disposed on the back surface side of the nozzle plate, a plurality of pressure generating means for pressurizing ink inside the plurality of pressure generating chambers and discharging ink droplets from the plurality of nozzle openings, A case member disposed on a side opposite to the nozzle plate with respect to the flow path substrate, wherein the ink remaining on the surface of the nozzle plate is absorbed by the wiping unit when the ink is wiped by the wiping unit. In order to remove the ink from the wiping means, an ink catching recess is formed from the surface of the nozzle plate to a part of the case member. An ink jet recording head characterized by being formed. 2. The printing apparatus according to claim 1, wherein the ink catching recess is formed at a position deviated to at least one side in the scanning direction of the recording head when viewed from the nozzle row forming area. Inkjet recording head. 3. The ink catching concave portion is formed at each position deviated to both sides in the scanning direction of the recording head when viewed from the nozzle row forming region. Inkjet recording head. 4. The ink-jet recording method according to claim 1, wherein the ink-jet recording device has a plurality of nozzle rows, and the ink-capturing recesses are formed at least between the nozzle rows. Type recording head. 5. The ink jet recording head according to claim 1, wherein the ink capturing recess is formed as an elongated groove parallel to the nozzle row. . 6. The ink jet recording head according to claim 5, wherein said elongated grooves are formed continuously along a direction parallel to said nozzle row. 7. An ink jet recording head according to claim 6, wherein said elongated grooves are formed in a plurality of parallel rows. 8. An ink jet recording head according to claim 5, wherein said elongated groove is formed intermittently along a direction parallel to said nozzle row. 9. An ink jet recording head according to claim 8, wherein said elongated grooves are formed in a plurality of rows parallel to each other and have the same intermittent pattern between the rows. 10. An ink jet recording head according to claim 8, wherein said elongated grooves are formed in a plurality of rows parallel to each other, and intermittent patterns of the rows are alternated. 11. The ink-jet recording apparatus according to claim 1, wherein the ink catching recess is formed as a plurality of holes arranged in a direction parallel to the nozzle row. Item 7. An ink jet recording head according to item 1. 12. The ink-jet apparatus according to claim 11, wherein the plurality of holes are formed in a plurality of rows parallel to each other, and the arrangement pattern of the holes in the rows is the same. Type recording head. 13. The ink-jet apparatus according to claim 11, wherein said plurality of holes are formed in a plurality of rows parallel to each other, and an arrangement pattern of said holes in said rows is alternated. Type recording head. 14. The ink catching concave portion extends along a direction parallel to the nozzle row and beyond a length corresponding to the nozzle row. 14. The ink jet recording head according to any one of 1 to 13. 15. The ink catching concave portion is located inside a sealing area on the surface of the nozzle plate sealed by capping means when sucking and discharging ink from the nozzle opening. The ink jet recording head according to any one of claims 1 to 14, wherein 16. An ink jet recording head according to claim 1, comprising a flexible wiper member sliding on said surface of said nozzle plate.
Wiping means for wiping ink remaining on the surface of the nozzle plate, sealing the surface of the nozzle plate to form a sealed space, and applying a negative pressure to the sealed space to form the nozzle opening and the nozzle An ink jet recording apparatus comprising: capping means for sucking and discharging ink from an ink capturing recess.