JPH09156116A - Inkjet recording device - Google Patents

Abstract

(57) An object of the present invention is to eliminate nozzle openings arranged in high density and ink dust and paper dust in the vicinity thereof without causing abrasion of a water repellent treatment layer and the like. An inkjet provided with a nozzle opening row in which a plurality of nozzle openings are arranged on the same straight line, and a nozzle plate 23 having craters 25 and 26 forming recesses so as to surround the same nozzle opening row. It is composed of a recording head and an elastic plate material of a polymer material, and a blade 31 having a constant inclination angle θ1 with respect to the nozzle opening array of the recording head and having a constant interference amount with respect to the nozzle plate 23 during cleaning. A cleaning device is provided, and the crater portion 2 is provided with a constant width smaller than the length of the crater portion 25 while sequentially changing the contact position of the blade 31.
5, 26 is contacted.

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 comprising a pressure generating chamber forming member, a nozzle plate having a nozzle opening communicating with the pressure generating chamber, and pressure generating means for pressurizing ink in the pressure generating chamber. The present invention relates to a recording device provided with, and more specifically, to a nozzle plate cleaning technique.

[0002]

2. Description of the Related Art As is well known, an ink jet head has a nozzle plate formed by forming nozzle openings in a thin plate member at a constant pitch, and a pressure generating chamber communicating with each nozzle opening.
The pressure generating chamber is provided with a reservoir chamber for supplying ink, and the ink in the pressure generating chamber is pressurized by a piezoelectric vibrator, a heating element, or the like to eject an ink droplet from a nozzle opening.

The ink jet recording head performs printing while keeping a distance such that it almost comes into contact with the recording paper, and since it contains solid components such as dyes, paper dust and ink dregs adhere to the nozzles, and the nozzle openings Since clogging is likely to occur, the nozzle plate is wiped with a blade made of a rubber plate or the like at regular intervals to remove paper dust and ink debris.

Since the gap between the nozzle plate and the recording paper is extremely small, the recording paper comes into contact with the nozzle openings,
Since the water-repellent layer provided around this may be worn away, as shown in FIG. 7, the nozzle openings N, N, N ...
In the area 100 to 150 μm apart from the center
Measures are taken to prevent the recording sheet from contacting the nozzle openings N, N, N ... By forming a metal layer having a thickness of 5 to 30 μm and positioning each nozzle opening in the crater portion C. .

However, when the arrangement pitch of the nozzle openings becomes small, it becomes difficult not only to form independent craters in each nozzle opening, but even if they are formed, the crater opening area is extremely small. As shown in FIG. 8, the blade B, which is a cleaning member, can only come into contact with a partial area of each of the craters C, C, C, and there is a problem that ink residue or the like remains at the corner G of the crater C. .

[0006]

In order to solve such a problem, it is conceivable to form a common crater portion around the nozzle openings in the same row, but in order to improve the printing quality and the printing speed, 1 If the length of the nozzle openings in a row is three times or more that of the conventional recording head, it is difficult to maintain the contact pressure between the wiping member and the nozzle plate constant for all the nozzles in the nozzle opening row. The contact pressure becomes too high in some parts, and the contact pressure becomes too low in some parts, causing problems such as abrasion of the water-repellent treatment layer and residual dust such as ink residue.

The present invention has been made in view of the above problems, and an object thereof is to prevent wear of the water repellent treatment layer regardless of the length of the nozzle opening row.
It is an object of the present invention to provide an ink jet recording apparatus capable of reliably removing paper dust and ink residue attached to a nozzle plate.

[0008]

In order to solve such a problem, in the present invention, a nozzle opening row in which a plurality of nozzle openings are arranged on the same straight line and the same nozzle opening row are surrounded. An ink jet recording head provided with a nozzle plate having a crater portion that forms a concave portion, and an elastic plate material of a polymer material, having a constant inclination angle with respect to the nozzle opening row of the recording head, and the recording head during cleaning. And a cleaning device including a blade in which a constant amount of interference is set with respect to the nozzle plate.

[0009]

The blade comes into contact with the inside of the crater portion with a constant width while sequentially changing its contact position. Since the crater portion is formed to be longer than the contact width of the blade, the blade keeps a constant contact pressure with the crater portion, and sufficiently contacts the inside and both side edge portions of the crater portion to scrape out ink residue and the like. .

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the present invention will be described below with reference to illustrated embodiments. FIG. 1 shows an embodiment of an ink jet recording apparatus of the present invention, in which reference numeral 1 is a carriage, which is supported by a guide member 2 and is connected to a step motor 4 via a timing belt 3. , And is configured to be capable of reciprocating in parallel with the platen 5.

Recording heads 6 and 7 are mounted on the surface of the carriage 1 facing the platen, and ink cartridges 8 and 9 for supplying ink to the recording heads 6 and 7 are mounted on the open side for easy ink exchange. , A print signal from the host via the flexible cable 10 to the recording head 6,
7, and ink droplets are ejected from the recording head to print characters and images.

At the non-printing area, that is, at the right end in the figure, the recording heads 6 and 7 are sealed at the time of non-printing, and the cap members 11 and 12 are supplied with a negative pressure from the pump unit 13. Is provided. A cleaning device 14, which will be described later, which is a feature of the present invention is arranged on the print region side of the cap members 11 and 12. Reference numeral 15 in the figure denotes a recording sheet.

The recording heads 6 and 7 will be described by way of example for monochrome printing. The recording heads 6 and 7 are equipped with piezoelectric vibrators that pressurize ink in the pressure generating chambers by applying drive signals, and communicate with these pressure generating chambers. As shown in FIG. 2, the nozzle opening 2
Nozzle plate 23 having a plurality of rows of nozzle openings 0, 20, ...

The surface of the nozzle plate 23 is shown in FIG.
Nozzle opening row 2 forming the same row as shown in
A metal layer 24 having a thickness of about 5 to 30 μm is provided by a technique such as eutectoid plating so as to surround the nozzle openings 1 and 22 and crater portions 25 and 26 that surround the nozzle opening rows with the same recesses are formed. A water-repellent layer 27 is formed on the surface of the metal layer 24 and the craters 25 and 26 by applying a water-repellent treatment agent to exhibit a non-affinity for the ink.

FIG. 3 shows the above-mentioned cleaning device 14, and reference numerals 31 and 32 in the drawing denote first blades 3 made of rubber plates having different elasticity and hardness.
1 and the second blade 32 formed of an ink absorbing plate such as a porous material, the walls 33a, 33b, 34a, 34b formed so that one side of the carriage movement path is high and the other side is low.
It is fixed to holders 33 and 34 provided with. These holders 33 and 34 are attached to the end portions of shafts 37 and 38 which are axially advanced and retracted and rotated by drive means 35 and 36, respectively.

In this embodiment, the recording heads 6 and 7 are
When the print signal is applied, the nozzle openings 20, 20
To form dots on the recording paper.

When a certain amount of data is printed in this way, paper dust and ink debris accumulate inside the nozzle openings 20 and the crater portion 25, causing deviations in the flight speed and direction of the ink droplets from the nozzle openings 20. Print quality deteriorates.

At this stage, when the carriage 1 is moved to the non-printing area and sealed with the cap members 11 and 12, and the negative pressure is supplied by the pump unit 13, the nozzle opening 20,
Ink is forcibly discharged from 20. As a result, the paper dust and ink dregs attached to the vicinity of the nozzle opening 20 are discharged to the cap members 11 and 12 together with the discharged ink. Due to the forced discharge of ink, ink droplets adhere to the crater portion 25.

Then, the driving means 35 is operated to move the first blade 31 to the nozzle plate 23 of the recording heads 6 and 7.
Until the predetermined interference amount ΔI (FIG. 4) is reached, and the blade 31 moves in the moving direction of the recording heads 6 and 7, that is, the nozzle opening array. It is rotated so as to form an inclination of a constant angle θ1 with respect to (FIG. 5 (A)).

When the carriage 1 is moved toward the printing area at the stage where the blade position is set in this way, the blade 31 makes a constant angle θ1 with respect to the direction of the nozzle opening row.
The blade 31 is elastically contacted with one end (upper end in the figure) of the crater portion 25 because of the inclination (FIG. 5B).

When the carriage 1 further moves in this state, the elastic contact position of the blade 31 sequentially moves downward (FIG. 5).
(C), (D)). As a result, the blade 31 contacts the inside of the crater portion 25 with a constant width ΔL shorter than the length of the crater portion 25 while sequentially changing the contact position. Therefore, the contact pressure of the blade 31 on the crater portion 25 is not so much influenced by the pressure of the blade 31, but rather depends on the width ΔL thereof. Therefore, by controlling the angle θ1, the crater portion 25 of the blade 31 is controlled. It is possible to control the contact pressure to the.

Further, since the contact width ΔL of the blade 31 can be formed long regardless of the nozzle pitch, the blade 31
However, the ink scraps and the like can be scraped out by sufficiently contacting both corner portions of the crater portion 25.

As described above, the blade 31 has the nozzle opening 2
0 from one end to the other end (lower end in the figure) (see FIG.
(E)) Ink dregs and paper dust are ejected out of the crater portion 25 together with the ink attached when the ink droplets are forcibly ejected.

If the nozzle plate 32 is extremely contaminated, the driving means 36 is operated to move the second blade 32 to a state where it has a certain amount of interference with the nozzle plate 23 of the recording head. The recording heads 6 and 7 are moved to the moving path, and the blade 32 is rotated so as to form an inclination of a constant angle θ2 with respect to the moving direction of the recording heads.

When the carriage 1 is moved to the printing area side when the blade position is set in this way, the blade 3 made of an ink absorbing plate and containing ink is used.
2 is a constant angle θ2 with respect to the direction of the nozzle opening row (see FIG. 6).
Due to the inclination at (a)), the blade 32 elastically contacts one end (upper end in the figure) of the crater portion 25. At this time,
By making the angle θ2 different from that of the first blade 31,
The contact pressure on the crater portion 25 can be adjusted, and the cleaning pressure suitable for the blade 32 can be set.

When the carriage 1 further moves in this state, the elastic contact position of the blade 32 sequentially moves downward (FIG. 6).
(B)). As a result, the blade 32 wets the ink residue with the ink and sequentially changes the contact position to scan the inside of the crater portion 25 and the nozzle opening 20 toward the other end (the lower end in the figure) (FIG. 6C). Ink dust and paper dust are discharged to the outside of the crater portion 25.

When the cleaning by the second blade 32 is completed, the above-mentioned operation is performed by the first blade 31 to remove the ink on the surface of the crater and the nozzle plate adhered by the cleaning by the second blade.

In the above-described embodiment, each blade is designed to set the amount of interference with the recording head by using a dedicated drive means, but the power of a paper feed motor or the like which is in a rest state during cleaning is used. The same effect can be obtained even if the adjustment is performed. Further, although the inclination angles θ1 and θ2 of the blades 31 and 32 can be set each time, the inclination angles θ1 and θ2 can be previously attached to the base and fixed.

[0029]

As described above, in the present invention, the nozzle opening row in which a plurality of nozzle openings are arranged on the same straight line and the crater portion forming the concave portion so as to surround the same nozzle opening row are provided. An ink jet recording head having a nozzle plate having the same and an elastic plate material of a polymer material, having a constant inclination angle with respect to the nozzle opening row of the recording head, and having a constant interference with the nozzle plate of the recording head during cleaning. Since the cleaning device is provided with the blade whose amount is set, the blade can be brought into contact with the inside of the crater portion with a constant width while sequentially changing the contact position, and the contact pressure to the crater portion of the blade can be increased. The wear of the water-repellent layer is controlled as much as possible by controlling the contact width, and at the same time, it is well within the crater and on both corners of the crater. To touch with Inkukasu like it can reliably scrape things.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of an ink jet recording of the present invention.

2A and 2B are top views showing an embodiment of the nozzle plate of the recording head, respectively.

FIG. 3 is a diagram showing an example of a cleaning device.

FIG. 4 is a diagram illustrating an amount of interference between a blade and a recording head.

5A to 5E are diagrams showing the cleaning operation by the first blade.

6A to 6C are diagrams showing a cleaning operation by the second blade.

FIG. 7 is a diagram showing an example of a nozzle plate in a conventional recording head.

FIG. 8 is a diagram showing a contact state between a blade and a crater portion of a conventional cleaning device.

[Brief description of reference numerals]

 1 Carriage 6 and 7 Recording Head 8 and 9 Ink Cartridge 11 and 12 Cap Member 13 Pump Unit 20 Nozzle Openings 21 and 22 Nozzle Opening Row 14 Cleaning Device 23 Nozzle Plate 25 and 26 Crater Section 31 and 32 Blades

Claims (4)

[Claims] 1. An ink jet recording head having a nozzle opening row in which a plurality of nozzle openings are arranged on the same straight line, and a nozzle plate provided with a crater portion that forms a concave portion so as to surround the same nozzle opening row. A cleaning having a blade made of a high-polymer elastic plate material, having a constant inclination angle with respect to the nozzle opening array of the recording head, and having a constant amount of interference with the nozzle plate of the recording head during cleaning. An ink jet recording apparatus comprising a device. 2. The ink jet recording apparatus according to claim 1, wherein a part of the blade moves partly and continuously to the crater portion from one end to the other end while changing the contact area. 3. The cleaning device includes first and second blades made of an elastic material having ink non-absorption and ink absorption, and the inclination angles with respect to the moving direction of the recording head are different. 1. Inkjet recording device 1. 4. The ink jet recording apparatus according to claim 1, wherein an interference amount and a tilt angle of the blade are variable.