JP2001287378A - Ink jet recording head - Google Patents

Abstract

[PROBLEMS] To provide an ink jet recording head capable of preventing wiping failure and the like and stabilizing ejection without increasing the size of the recording head. SOLUTION: This is a recording head used for a recording apparatus including a nozzle plate 17 having a nozzle row 7 formed thereon and a wiper member for wiping a nozzle surface of the nozzle plate 17, wherein the nozzle row 7 in the nozzle plate 17 is provided. Is shifted in the wiping direction A by the wiper member, and the nozzle surface on the side L1 where the wiper member enters is widened, so that the wiper member is brought into contact with the nozzle surface before wiping until the nozzle line 7 is reached. The region L1 is sufficiently wide, and the wiper member stably adheres to the nozzle surface before the wiper member reaches the nozzle row 7, and wiping or the like is sufficiently performed. Therefore, wiping defects can be prevented, ejection can be stabilized, and the size of the recording head does not increase.

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 recording images and characters on recording paper by discharging ink droplets from nozzle openings.

[0002]

2. Description of the Related Art In general, an ink jet recording head using a piezoelectric vibrator (hereinafter referred to as a "recording head") has a nozzle row 46 comprising a plurality of nozzle openings 45 for discharging ink droplets, as shown in FIG. A nozzle plate 48 formed, a flow path forming member (hidden and not visible in the figure) formed with a flow path attached to the lower surface of the nozzle plate 48 and communicating with the nozzle opening 45, and the flow path forming member Attached to the lower surface of the piezoelectric vibrator (hidden and invisible in the figure)
And a head case 47 for accommodating the same. In the figure, reference numeral 51 denotes a protective cover that protects from the periphery of the nozzle surface of the nozzle plate 48 to the upper side of the side surface of the head case 47; 50, a drive circuit board that generates a drive signal input to the piezoelectric vibrator; 49 is an adhesive.

In the recording head, as shown in FIG. 13, the nozzle rows 46 are arranged at the center with respect to the nozzle plate 48, and the nozzle rows 46 are symmetrical about the center of the nozzle plate 48. It has become. Therefore, the distance L1 from one end of the nozzle plate 48 to the nozzle row 46 near the one end is equal to the distance L2 from the other end of the nozzle plate 48 to the nozzle row 46 near the other end.

[0004]

However, in the above-described recording head, when the nozzle surface of the nozzle plate 48 is wiped in the direction A, for example, from when the wiper member contacts the nozzle surface until it reaches the nozzle row 46. Area L1
And the region L2 from when the wiper member leaves the nozzle row 46 to when it leaves the nozzle surface is equal. Therefore, since the area L1 before wiping is not sufficiently large,
When the wiper member reaches the nozzle row 46, the wiper member may not stably adhere to the nozzle surface, and wiping or the like may not be performed sufficiently. As described above, when the wiping is insufficient, the ejection may be unstable due to the ink remaining around the nozzle opening 45 on the nozzle surface.

In the above-described recording head, since the area L1 before wiping is not sufficiently large, the ink adhering to the wiper member is wiped without being sufficiently wiped before the wiper member reaches the nozzle row 46. Sometimes. As described above, if ink adheres to the wiper member at the time of wiping, wiping or the like may not be performed sufficiently, and ejection may be unstable. Therefore, although the use of a nozzle plate having a large dimension in the wiping direction A can improve the situation, the size of the recording head itself increases, and it is not possible to meet the demand for miniaturization and compactness.

The present invention has been made in view of such circumstances, and provides an ink jet recording head capable of preventing wiping failure and the like and stabilizing ejection without increasing the size of the recording head. With that purpose.

[0007]

In order to achieve the above object, an ink jet recording head according to the present invention comprises a nozzle plate having a nozzle array formed of a plurality of nozzle openings, and a pressure generator communicating with the nozzle openings. A wiper for wiping and / or rubbing the nozzle surface of the nozzle plate, comprising a chamber, a pressure generating element for generating pressure in the pressure generating chamber, and an ink storage chamber for storing ink to be supplied to the pressure generating chamber. An ink jet recording head used in an ink jet recording apparatus having a member, wherein a position of a nozzle row in the nozzle plate is shifted in a wiping direction by the wiper member, and a nozzle surface on a side where the wiper member enters is provided. The gist is that it is wide.

That is, in the ink jet recording head of the present invention, the position of the nozzle row on the nozzle plate is
The nozzle surface is shifted in the wiping direction by the wiper member, and the nozzle surface on the side where the wiper member enters is widened. For this reason, the area before wiping from when the wiper member contacts the nozzle surface to when the wiper member reaches the nozzle row is sufficiently widened. Therefore, the wiper member stably adheres to the nozzle surface before the wiper member reaches the nozzle row, and wiping and / or rubbing is sufficiently performed. Also, the ink adhered to the wiper member after wiping,
The wiper member is wiped sufficiently until it reaches the nozzle row,
Wiping and the like are sufficiently performed. As described above, the occurrence of the wiping defect is prevented, and the ejection can be stabilized. In addition, since the nozzle plate may be the same size as the conventional one, the size of the recording head is not increased.

In the ink jet recording head of the present invention, when a plurality of nozzle rows are provided,
In a print head having a plurality of nozzle rows, it is possible to prevent wiping defects without increasing the size of the print head and to stabilize ejection.

In the ink jet recording head of the present invention, the nozzle row located on the side where the wiper member enters is divided into a plurality of nozzle opening groups, and different types of ink are ejected from each nozzle opening group. In such a case, a structural margin is provided, and the degree of freedom in design is increased.
That is, when a single nozzle row is divided into a plurality of nozzles and different types of ink are ejected, a plurality of ink storage chambers are provided for one nozzle row, and each ink storage chamber is provided from an ink supply unit communicating with an ink cartridge or the like. Must be provided in a limited space. Therefore, by arranging a nozzle row that ejects a plurality of types of ink in one row on the side where the wiper member enters,
A large space can be provided for providing a plurality of ink storage chambers and a flow path for guiding ink to each ink storage chamber, so that there is a structural margin and the degree of freedom in design is increased.

In the ink jet recording head according to the present invention, when the different types of inks are inks of different colors, the recording head ejecting a plurality of colors of ink in one row can be used without increasing the size of the recording head. In addition to preventing wiping defects and stabilizing the ejection, structural margin is provided and design freedom is increased.

In the ink jet recording head according to the present invention, when a concave portion and / or a convex portion which comes into contact with the wiper member to be wiped is formed on the nozzle surface on the side where the wiper member enters, the wiper member is provided before the wiping. By contacting the concave and / or convex portions, the ink adhered to the wiper member is sufficiently wiped, thereby preventing wiping defects from occurring and stabilizing ejection.

In the ink jet recording head according to the present invention, when the concave and / or convex portions are concave and / or convex portions extending in a direction intersecting with the wiping direction, the wiper member is provided with the concave and / or convex portions before wiping. By contacting the ridges and / or the ridges, the ink adhered to the wiper member is sufficiently wiped, the occurrence of wiping defects is prevented, and the ejection can be stabilized.

In the ink jet recording head according to the present invention, when a piezoelectric vibrator in a flexural vibration mode is used as the pressure generating element, the recording head using the piezoelectric vibrator in a flexural vibration mode is used for recording. The occurrence of wiping failure can be prevented without increasing the size of the head, and the ejection can be stabilized.

In the ink jet recording head of the present invention, when a piezoelectric vibrator in a longitudinal vibration mode is used as the pressure generating element, the recording head using the piezoelectric vibrator in a longitudinal vibration mode is used for recording. The occurrence of wiping failure can be prevented without increasing the size of the head, and the ejection can be stabilized.

In the ink jet recording head of the present invention, when a heating element for heating the ink in the flow path is used as the pressure generating element, the recording head using the heating element as the pressure generating element may be used. Further, it is possible to prevent the occurrence of wiping failure without increasing the size of the recording head, and to stabilize the ejection.

[0017]

Next, embodiments of the present invention will be described in detail.

FIG. 1 is a diagram showing an example of a peripheral structure of an ink jet recording apparatus to which an ink jet recording head (hereinafter, referred to as a "recording head") of the present invention is applied.
The apparatus includes a carriage 32 having an ink cartridge 30 mounted on an upper portion thereof and a recording head 31 mounted on a lower surface, a cap 33 for sealing a nozzle surface of the recording head 31 to prevent drying of ink, And a wiper member 39 for wiping and / or rubbing the nozzle surface of the nozzle 31.

The ink cartridge 30 is divided into a black cartridge containing black (BK) ink and three ink chambers.
3 for cyan (C), magenta (M), and yellow (Y)
Two types of color cartridges containing different types of ink are mounted.

The carriage 32 is connected to a stepping motor 34 via a timing belt 37, and is guided by a guide bar 35 to reciprocate in the main scanning direction (the width direction of the recording paper 36). A recording head 31 is attached to the carriage 32 on a surface facing the recording paper 36 (a lower surface in this example). Then, each ink cartridge 30 is attached to the recording head 31.
Is supplied from the printer, ink droplets are ejected onto the upper surface of the recording paper 36 while moving the carriage 32, and images and characters are printed on the recording paper 36 in a dot matrix.

The cap 33 is provided in a non-printing area within the movement range of the carriage 32, and seals the nozzle opening of the recording head 31 during printing suspension so as to prevent drying of the nozzle opening as much as possible. . The capping device 33 may also function as a container for receiving ink droplets ejected from the recording head 31 by a flushing operation or the like. Further, the capping device 33 is connected to a suction pump, and applies a negative pressure to the nozzle opening 3 of the recording head 31 to suction ink from the nozzle opening 3 during a cleaning operation.

In the vicinity of the cap, the wiper member 3
9 are installed. As shown in FIG. 2, the wiper member 39 is configured such that an elastic plate 41 such as a rubber plate and an ink absorbing material 42 are attached to each other, and these are attached to a lever 40. This wiper member 39 is
When the recording head 31 moves to the cap 33, it rises so as to contact the nozzle surface of the nozzle plate 17 in conjunction with the movement of the carriage 32, or moves horizontally in the feed direction of the recording paper 36 to wipe off the ink on the nozzle surface. It has become.

[0023] Such wiping and / or rubbing is performed at each cleaning to remove excess ink on the nozzle surface after suction of ink by the pump.
Printing is performed after wiping and / or rubbing is performed. The wiping direction during wiping and / or rubbing is always constant. In FIG. 1, 38
Is a paper feed roll.

As the recording head 31, for example, the recording head shown in FIGS. 3 and 4 is used. This recording head 31
A piezoelectric vibrator 6 of a flexural vibration mode is used. The piezoelectric vibrator 6 is adhered to the upper surface, and the piezoelectric vibrator 6
, An actuator unit 1 in which a plurality of pressure generating chambers 2 are formed, a nozzle opening 3 and an ink storage chamber 4
And a flow path unit 5 adhered to the lower surface of the actuator unit 1, which generates pressure in the pressure generating chamber 2 by the vibration of the piezoelectric vibrator 6,
The ink droplets are ejected from the printer.

The actuator unit 1 has a pressure chamber forming plate 10 in which a space for forming the pressure generating chamber 2 is formed.
A vibration plate 11 located on the upper surface of the pressure chamber forming plate 10 and closing the upper opening of the space; and a communication hole forming plate 14 located on the lower surface of the pressure chamber forming plate 10. The communication hole forming plate 14 includes an ink storage chamber 4 and a pressure generation chamber 2.
And a second communication hole 13 that allows the pressure generating chamber 2 and the nozzle opening 3 to communicate with each other.

The actuator unit 1 has a comb-shaped lower electrode 19 formed on the upper surface of the diaphragm 11. Each comb tooth 19A of the lower electrode 19 is formed at a portion that covers the upper part of the pressure generating chamber 2. Then, a flat-plate-shaped piezoelectric vibrator 6 is formed on the upper surface of each comb tooth portion 19A of the lower electrode 19, and an individual upper electrode 20 is formed on the upper surface of the piezoelectric vibrator 6.

Further, terminals 21 are formed at both ends of the upper surface of the actuator unit 1 so as to be electrically connected to the upper electrode 20 of each piezoelectric vibrator 6. A flexible circuit board 22 is stretched on the upper surface of the terminal 21, and a drive signal is applied to the piezoelectric vibrator 6 via the terminal 21 and the upper electrode 20.

On the other hand, the flow path unit 5 includes a storage chamber forming substrate 16 in which a space for forming the ink storage chamber 4 is formed.
And the nozzle opening 3 is formed, and the storage chamber forming substrate 16 is formed.
And a flow path forming plate 18 positioned on the upper surface of the storage chamber forming substrate 16.

A first ink flow path 9 communicating with the nozzle opening 3 is formed in the storage chamber forming substrate 16. Further, the first passage forming plate 18 is provided with the first
An ink supply port 15 for supplying ink to the pressure generating chamber 2 is formed through the communication hole 12, and the pressure generating chamber 2 and the second communication hole 13 communicate with the first ink flow path 9 and the nozzle opening 3. A second ink flow path 8 to be formed is formed. In FIG. 3, reference numeral 24 denotes an ink supply port for supplying ink to the ink storage chamber 4 from an ink cartridge (not shown).

In the recording head, when a drive signal is applied to the piezoelectric vibrator 6, the piezoelectric vibrator 6 contracts in the horizontal direction. At this time, the lower surface side of the piezoelectric vibrator 6 fixed to the vibration plate 11 does not contract, but only the upper surface side contracts. Therefore, the piezoelectric vibrator 6 and the vibration plate 11 bend downward and compress the pressure generating chamber 2. . When the pressure in the pressure generating chamber 2 rises, the ink in the pressure generating chamber 2 is ejected from the nozzle openings 3 as ink droplets, and dots are formed on recording paper or the like to perform printing. Next, when the piezoelectric vibrator 6 is discharged and returns to the original state, the pressure in the pressure generating chamber 2 is reduced, and new ink is supplied from the ink storage chamber 4 to the pressure generating chamber 2 through the ink supply port 15.

FIG. 5 shows an embodiment of the recording head 31 of the present invention. This recording head 31 shows an example in which two nozzle rows 7 are formed. In the recording head 31, each nozzle row 7 is not allocated to the center, and the position of each nozzle row 7 in the nozzle plate 17 is shifted in the wiping direction A by the wiper member 39.
The nozzle surface L1 on the side where the wiper member 39 enters is wider than the nozzle surface L2 on the opposite side.

As a result, in the recording head 31, the area L1 before wiping from when the wiper member 39 contacts the nozzle surface to when the nozzle row 7 is reached is sufficiently widened.
Therefore, the wiper member 39 stably adheres to the nozzle surface before the wiper member 39 reaches the nozzle row 7,
Wiping and the like are sufficiently performed. Further, the ink adhered to the wiper member 39 after the wiping is removed by the wiper member 3.
9 is sufficiently wiped before it reaches the nozzle row 7, and wiping and the like are sufficiently performed. In this manner, occurrence of wiping defects is prevented, and ejection can be stabilized. Further, since the nozzle plate 17 may be the same size as in the related art, the size of the recording head 31 is not increased.

FIG. 6 shows an ink jet recording head according to a second embodiment of the present invention. In this case, a plurality of ridges 26 extending in a direction perpendicular to the wiping direction A are engraved in an area L1 before wiping. Other than that,
This is the same as the first embodiment, and the same parts are denoted by the same reference numerals. In this recording head, the ink adhered to the wiper member 39 is sufficiently wiped by the wiper member 39 contacting the concave streak 26 before the wiping, thereby preventing the occurrence of wiping failure and stabilizing the ejection. it can. Otherwise, the same operation and effect as those of the first embodiment are exerted.

FIG. 7 shows an ink jet recording head according to a third embodiment of the present invention. In this case, not the ridge 26 but the ridge 27 is formed in the region L1 before wiping. The other parts are the same as those of the second embodiment, and the same parts are denoted by the same reference numerals. In this recording head, the ink adhered to the wiper member 39 is sufficiently wiped by the wiper member 39 coming into contact with the ridge 27 before wiping, thereby preventing wiping defects from occurring and stabilizing ejection. it can. Other than that,
The same operation and effect as those of the second embodiment are provided.

FIG. 8 shows an ink jet recording head according to a fourth embodiment of the present invention. In this case, not only the ridges 26 but also the ridges 27 are formed in the region L1 before wiping. The other parts are the same as those of the second embodiment, and the same parts are denoted by the same reference numerals. In this recording head, the ink adhered to the wiper member 39 is sufficiently wiped by the wiper member 39 contacting the concave ridges 26 and the convex ridges 27 before wiping. Can be achieved. Except for the above, the same operation and effect as those of the second embodiment are exerted.

FIG. 9 shows an ink jet recording head according to a fifth embodiment of the present invention. In this example, the concave stripes 26 formed in the region L1 before wiping are formed in two steps not in a direction orthogonal to the wiping direction A but in an oblique direction intersecting with the wiping direction A. The other parts are the same as those of the second embodiment, and the same parts are denoted by the same reference numerals. This recording head also has the same operation and effect as the second embodiment.

FIG. 10 shows an ink jet recording head according to a sixth embodiment of the present invention. In this case, a square concave portion 28 is formed in the region L1 before wiping, instead of the concave line 26 and the convex line 27. The other parts are the same as those of the second embodiment, and the same parts are denoted by the same reference numerals. This recording head also has the same operation and effect as the second embodiment.

FIG. 11 shows an ink jet recording head according to a seventh embodiment of the present invention. This is because the nozzle row 7 located on the side where the wiper member 39 enters,
A group of a plurality of (three in this example) nozzle openings 3 (Y group, M
Group, group C). Then, the Y group, M
Ink storage chambers 4 (Y), 4 in which inks of different colors are stored for each of the nozzle openings 3 of the group and the group C.
(M) and 4 (C) communicate with each other, and ink of different colors of Y, M and C is ejected from the group of the nozzle openings 3. The other parts are the same as those in the first embodiment, and the same parts are denoted by the same reference numerals.

As described above, when one nozzle row 7 is divided into a plurality of sections to eject inks of different colors, a plurality of ink storage chambers 4 are provided for one nozzle row 7 and communicate with an ink cartridge or the like. A flow path for guiding ink from the ink supply unit to each of the ink storage chambers 4 must be provided in a limited space. Therefore, as described above, the nozzle row 7 that ejects a plurality of colors of ink in one row is connected to the wiper member 3.
By arranging them on the side where the nozzles 9 enter, it is possible to increase the space for providing a plurality of ink storage chambers 4 and a flow path for guiding ink to each of the ink storage chambers 4, thereby allowing a structural margin and free design. The degree increases. Otherwise, the same operation and effect as those of the first embodiment are exerted.

In each of the above embodiments, the present invention
Although an example in which the present invention is applied to a recording head using a piezoelectric vibrator 6 in a flexural vibration mode as a pressure generating element has been described, the present invention can be applied to a recording head using a piezoelectric vibrator in a longitudinal vibration mode. The present invention can also be applied to a recording head using a heating element for heating and vaporizing ink as an element.

[0041]

As described above, according to the ink jet recording head of the present invention, the area before the wiping from when the wiper member contacts the nozzle surface to when the wiper member reaches the nozzle row is sufficiently widened. Therefore, the wiper member stably adheres to the nozzle surface before the wiper member reaches the nozzle row, and wiping and / or rubbing is sufficiently performed. Further, the ink adhered to the wiper member after the wiping is sufficiently wiped until the wiper member reaches the nozzle row, and wiping or the like is sufficiently performed. As described above, the occurrence of the wiping defect is prevented, and the ejection can be stabilized. In addition, since the nozzle plate may be the same size as the conventional one, the size of the recording head is not increased.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a peripheral structure of a recording apparatus using an ink jet recording head of the present invention.

FIG. 2 is a perspective view showing a wiper member.

FIG. 3 is an exploded perspective view showing a basic structure of the ink jet recording head of the present invention.

FIG. 4 is a sectional view of the ink jet recording head.

FIG. 5 is a diagram showing a nozzle plate of the ink jet recording head according to one embodiment of the present invention.

FIG. 6 is a diagram showing a second embodiment of the present invention;
(A) is a figure which shows a nozzle plate, (b) is sectional drawing of a nozzle plate.

FIG. 7 is a sectional view of a nozzle plate according to a third embodiment of the present invention.

FIG. 8 is a sectional view of a nozzle plate according to a fourth embodiment of the present invention.

FIG. 9 is a diagram showing a fifth embodiment of the present invention;
(A) is a figure which shows a nozzle plate, (b) is sectional drawing of a nozzle plate.

FIG. 10 is a diagram showing a sixth embodiment of the present invention;
(A) is a figure which shows a nozzle plate, (b) is sectional drawing of a nozzle plate.

FIG. 11 is an explanatory diagram showing a positional relationship between a pressure generating chamber and an ink storage chamber of an ink jet recording head according to a seventh embodiment of the present invention.

FIG. 12 is a perspective view of a conventional ink jet recording head viewed from below.

FIG. 13 is a view showing a nozzle plate of the conventional example.

[Explanation of symbols]

 7 Nozzle row 17 Nozzle plate A Wiping direction

Claims (9)

[Claims] A nozzle plate formed with a nozzle row including a plurality of nozzle openings; a pressure generating chamber communicating with the nozzle opening; a pressure generating element configured to generate pressure in the pressure generating chamber; An ink storage chamber for storing ink supplied to the nozzle plate, and an ink jet recording head used in an ink jet recording apparatus having a wiper member for wiping and / or rubbing the nozzle surface of the nozzle plate, wherein the nozzle plate Wherein the position of the nozzle row is shifted in the wiping direction by the wiper member, and the nozzle surface on the side where the wiper member enters widens. 2. The ink jet recording head according to claim 1, wherein a plurality of nozzle rows are provided. 3. The nozzle row positioned on the side where the wiper member enters is divided into a plurality of nozzle opening groups, and different types of ink are ejected from each nozzle opening group. Inkjet recording head. 4. The ink jet recording head according to claim 3, wherein the different types of ink are inks of different colors. 5. The ink jet recording according to claim 1, wherein a concave portion and / or a convex portion that contacts the wiper member to be wiped is formed on a nozzle surface on a side where the wiper member enters. head. 6. The ink jet recording head according to claim 5, wherein the concave and / or convex portions are concave and / or convex lines extending in a direction intersecting with the wiping direction. 7. The ink jet recording head according to claim 1, wherein a flexural vibration mode piezoelectric vibrator is used as the pressure generating element. 8. The ink jet recording head according to claim 1, wherein a piezoelectric vibrator in a longitudinal vibration mode is used as the pressure generating element. 9. The ink jet recording head according to claim 1, wherein a heating element for heating ink in the flow path is used as the pressure generating element.