JPH06155755A - Ink jet device - Google Patents

Abstract

PURPOSE:To prevent the adhesion of dust to the nozzle surface of an ink jet head. CONSTITUTION:A nozzle plate 31 having ink jet nozzles 32 formed thereto is constituted of a nozzle plate substrate 35 and a thin Cu conductive member layer 33 (several mum) and one terminal of a conductor 34 is connected to the conductive member layer 33 and the other terminal thereof is earthed. Since the static electricity generated by sliding a wiper member 68 on the surface of the nozzle plate 31 in order to clean the nozzle surface of the nozzle plate is discharged from the conductive member layer 33 of the nozzle plate 31 through the lead 34, the adhesion of dust to the nozzle parts and other part of the nozzle plate 31 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet device having an ejecting means for ejecting ink droplets through a nozzle and a wiper means for sliding the nozzle surface of the ejecting means to clean the surface.

[0002]

2. Description of the Related Art A schematic structure of an ink jet device of this type will be described with reference to FIGS.

As shown in FIG. 7, the ink jet printer head 1 is composed of a piezoelectric ceramic plate 2, a cover plate 3, a nozzle plate 31, and a substrate 41.

A plurality of grooves 8 are formed in the polarized piezoelectric ceramics plate 2 by grinding or the like using a thin disk-shaped diamond blade. Therefore, the side wall 11 that is the side surface of the groove 8 has the arrow 5
(See FIG. 5). The grooves 8 are of the same depth and are parallel. The depths of the grooves 8 gradually become shallower as they approach the one end face 15 of the piezoelectric ceramic plate 2, and the shallow groove 1 is formed near the one end face 15.
6 is formed. Then, on the inner surface of the groove 8, metal electrodes 13 are formed on the upper half of both side surfaces by sputtering or the like. The metal electrode 9 is formed on the inner surface of the shallow groove 16 on the side surface and the bottom surface by sputtering or the like. As a result, the metal electrodes 13 formed on both side surfaces of the groove 8 are connected by the metal electrodes 9 formed in the shallow groove 16.

Next, the cover plate 3 is made of a ceramic material, a resin material, or the like. Then, the cover plate 3 is formed by grinding or cutting.
An ink inlet 21 and a manifold 22 are formed. Then, the surface of the piezoelectric ceramic plate 2 on the side where the groove 8 is processed and the surface of the cover plate 3 on the side where the manifold 22 is processed are bonded by an epoxy adhesive or the like. Therefore,
The ink jet printer head 1 has a plurality of ink flow paths 1 which are covered with the upper surfaces of the grooves 8 and are laterally spaced from each other.
2 is configured. As shown in FIG. 5, the ink flow path 1
2 is an elongated shape having a rectangular cross section, and ink is filled in all the ink flow paths 12.

To the end faces of the piezoelectric ceramic plate 2 and the cover plate 3, a nozzle plate 31 having a nozzle 32 provided at a position corresponding to the position of each ink flow path 12 is adhered. The nozzle plate 31 is formed of a plastic such as polyalkylene (for example, ethylene), terephthalate, polyimide, polyetherimide, polyetherketone, polyethersulfone, polycarbonate, or cellulose acetate.

A substrate 41 is adhered to the surface of the piezoelectric ceramic plate 2 opposite to the processed side of the groove 8 with an epoxy adhesive or the like. Its substrate 41
A conductive layer pattern 42 is formed at a position corresponding to the position of each ink flow path 12. The pattern 42 of the conductive layer and the metal electrode 9 on the bottom surface of the shallow groove 16 are connected by a conductive wire 43 by wire bonding.

Next, the configuration of the control unit will be described with reference to FIG. 8 showing a block diagram of the control unit. The conductive layer patterns 42 formed on the substrate 41 are individually connected to the LSI chip 51. The clock line 52, the data line 53, the voltage line 54, and the ground line 55 are also LS.
It is connected to the I-chip 51. The LSI chip 51 is
Based on the continuous clock pulse supplied from the clock line 52, it is determined from which nozzle 32 the ink droplet should be ejected according to the data appearing on the data line 53. Then, the voltage V of the voltage line 54 is applied to the pattern 42 of the conductive layer that is electrically connected to the metal electrode 13 in the driven ink flow path 12. Further, the voltage 0V of the ground line 55 is applied to the pattern 42 of the conductive layer which is electrically connected to the metal electrode 13 other than the driven ink flow path 12.

Next, the operation of the ink jet printer head 1 will be described with reference to FIGS. LSI chip 5
1 determines that the ink is to be ejected from the ink flow path 12b of the inkjet printer head 1 according to the required data. Then, the positive drive voltage V is applied to the metal electrodes 13e and 13f, and the metal electrodes 13d and 13g are grounded.

As shown in FIG. 6, an arrow 1 is formed on the side wall 11b.
A driving electric field in the direction of 4b is generated, and an arrow 1 is formed on the side wall 11c.
A driving electric field in the direction 4c is generated. Then, since the driving electric field directions 14b and 14c are orthogonal to the polarization direction 4, the side walls 11b and 11c are rapidly deformed inward in the ink flow path 12b due to the piezoelectric thickness sliding effect. Due to this deformation, the volume of the ink flow path 12b is reduced, the ink pressure is rapidly increased, and a pressure wave is generated,
Ink droplets are ejected from the nozzle 32 (FIG. 7) communicating with the ink flow path 12b. Further, when the application of the drive voltage V is stopped, the side walls 11b and 11c are in the positions before the deformation (see FIG.
(See the reference), the ink pressure in the ink flow path 12b gradually decreases. Then, ink is supplied from the ink supply port 21 (FIG. 7) through the manifold 22 (FIG. 7) into the ink flow path 12b.

Next, the construction of the ink jet printer will be described with reference to FIG. The ink jet printer head 1 and the ink container 61 described above are joined so that the ink introduction port 21 (FIG. 7) of the ink jet printer head 1 and the inside of the ink container 61 communicate with each other. When the ink inside the ink container 61 is consumed, the ink container 61 is removed from the carriage 62 and replaced with a new one. The carriage 62 reciprocates on the slider 63, and the inkjet printer head 1 prints and records on the recording paper 66 held by the platen 64. The recording paper 66 is moved by the paper feed rollers 65a and 65b in a direction orthogonal to the moving direction of the carriage 62. As a result, the inkjet printer head 1 can print and record on the entire surface of the recording paper 66.

In such an ink jet printer, small ink droplets are generated when ejecting ink droplets, and a part of the ink droplets adheres to the surface of the nozzle plate 31.
If left undisturbed, ink gradually accumulates on the surface of the nozzle plate 31, and it becomes impossible to eject ink droplets. Therefore, the carriage 62 moves to the leftmost non-printing area for a proper period after the printing is completed or when the use of the inkjet printer is completed. At this time, the surface of the nozzle plate 31 moves to the left while the surface of the nozzle plate 31 is engaged with the wiper member 68 provided on the supporting member 69 fixed to the non-printing area and formed of resin or fiber such as cotton. By this sliding operation, the ink droplets adhering to the surface of the nozzle plate 31 are removed by the wiper 68. When a large amount of ink adheres to the wiper member 68, the wiper member 68 is replaced with a new one.

A moving means for moving the wiper member 68 is provided, and the wiper member 68 is provided on the surface of the nozzle plate 31 of the ink jet head 1 moved to the non-printing area.
May be moved and slid.

[0014]

In the conventional ink jet printer as described above, since the nozzle plate 31 and the wiper member 68 slide to remove the ink adhering to the surface of the nozzle plate 31, the nozzle plate 31 is removed. Static electricity is generated on the surface of and the wiper member 68,
Therefore, there is a problem that the surface of the nozzle plate 31 is likely to be covered with dust, and sometimes the nozzle hole is covered with dust, which hinders the ejection of ink.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an ink jet device which prevents dust from adhering to the nozzle surface of the ejection means.

[0016]

In order to achieve this object, in the present invention, jetting means for jetting ink droplets through a nozzle, and wiper means for sliding the nozzle surface of the jetting means to clean the surface. In the ink jet device having the above, the electrostatic discharge means is provided on the nozzle surface of the jetting means or the wiper means and discharges static electricity generated by the sliding.

In one embodiment, the electrostatic discharge means includes a conductive conductive layer provided on the nozzle surface of the spraying means, and a grounding member connected to the conductive layer. In another embodiment, the wiper means includes a wiper portion formed of resin mixed with conductive powder and sliding on the nozzle surface of the ejection means, and the electrostatic discharge means is provided in the wiper portion. It includes a connected ground member.

[0018]

In the ink jet device of the present invention having the above structure, the electrostatic discharge means provided on the nozzle surface of the jetting means or the wiper means discharges the static electricity generated by the sliding. Therefore, it is possible to prevent dust from adhering to the nozzle surface of the ejection unit.

More specifically, in one embodiment, the static electricity generated by the sliding is discharged by a grounding member connected to a conductive conductive layer provided on the nozzle surface.

In another embodiment, the static electricity generated on the nozzle surface of the jetting means by the sliding passes through the wiper portion of the wiper means formed of resin mixed with conductive powder, It is discharged by the earth member connected to the wiper part.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention will be described below with reference to FIG.
~ It demonstrates in detail with reference to FIG. For the sake of convenience, the same parts, equivalent parts, and same functions as those in the conventional technique are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 1, the nozzle plate 31 includes a nozzle plate substrate 35 and a thin conductive member layer 33 of Cu.
(Several μm). The conductive member layer 33 is formed on the nozzle plate substrate 35 by vapor deposition. Although Cu is used for the conductive member layer 33 in this embodiment, any other metal or a metal other than metal may be used as long as it is a substance having conductivity and abrasion resistance superior to that of the nozzle plate substrate 35. Further, the formation method thereof may be any other method that can form a uniform layer, such as sputtering. Further, for the nozzle plate substrate 35, a polyimide resin is used in this embodiment among the above-mentioned plastic materials.

As shown in FIG. 2, the conductive member layer 33 and the nozzle plate substrate 35 are simultaneously punched to form the nozzle 32. This drilling is preferably the most suitable for fine drilling, and in this embodiment, the krypton-Fusso excimer laser light 70 having a wavelength of 248 nm obtained from the excimer laser device 73 is used. Nozzle 32
The excimer laser device 73 drills holes from the nozzle plate substrate 35 side through the mask 71 and the lens 72 having a shape similar to the shape and pitch. As a result, a plurality of holes having a diameter of 30 μm are formed at the same pitch.

Here, in the boring process using the excimer laser beam 0, as shown in FIG. 2, generally, the hole diameter on the laser incident side is larger than the hole diameter on the emitting side, that is, a tapered hole is machined.

In general, the nozzle shape is such that the ink flow path side has a taper with a hole diameter larger than the ink ejection side, the ink flow path side has a taper with a hole diameter smaller than the ink ejection side, and the ink flow furnace side. And the ink ejection side have the same hole diameter, that is, the amount of ink droplets and the ejection speed are more stable than those of a straight nozzle hole having no taper. Therefore, it is desirable that the nozzle plate substrate 35 be drilled from the side.

Further, when the metal is processed by the excimer laser beam 70, generally, more energy is required than that required for processing the resin material such as polyimide, so that the metal is formed on the nozzle plate substrate 35. It is desirable that the conductive member layer 33 be thinner than the nozzle plate substrate 35.

Further, the conductive member layer 33 may be processed by etching or the like other than processing by the excimer laser 70. Further, a metal film or the like having a predetermined hole formed therein may be adhered to the nozzle plate substrate 35 made of polyimide or the like by electroforming or the like.

As shown in FIG. 3, the conductive member layer 33 includes:
One end of the conductive wire 34 is connected and the other end is grounded. Here, the conductive wire 34 need not be a metal as long as it has conductivity.

Then, in order to remove the ink droplets adhering to the surface of the nozzle plate 31, the carriage 62 is moved to the leftmost non-printing area for an appropriate period after printing is completed or when the ink jet printer is used up. At this time, the surface of the nozzle plate 31 moves to the left while the surface of the nozzle plate 31 is engaged with the wiper member 68 provided on the supporting member 69 fixed to the non-printing area and formed of resin or fiber such as cotton. By this sliding operation, the nozzle plate 31
The ink droplets adhering to the surface of the are removed by the wiper 68.

In the ink jet printer having the above-mentioned structure, the wiper member 68 and the nozzle plate 31 for removing ink droplets adhering to the surface of the nozzle plate 31.
Since static electricity generated by sliding on the surface of the nozzle plate 31 is discharged from the conductive member layer 33 of the nozzle plate 31 through the conductive wire 34, dust is not attached to the nozzle plate 31 and the portion other than the nozzle 32. To be prevented.

Furthermore, even when the pigment ink containing the solid matter is used and the solid matter of the pigment ink comes into contact with the nozzle 32 at the time of ink ejection, the nozzle 32 of the nozzle plate 31 of this embodiment has a nozzle 32 on the ink ejection side. Since the metal conductive member layer 33 is formed and the metal is harder than the solid matter of the pigment ink, the conductive member layer 33 is not scraped. Therefore, the deformation of the hole shape on the ejection side of the nozzle 32, which tends to cause ink droplets, is prevented.

In this embodiment, the nozzle plate substrate 3
Although the nozzle plate 31 composed of 5 and the conductive member layer 33 is used, the conductive member layer 33 may be provided on the nozzle surface of the inkjet printer head 1 having no nozzle plate 31 and having the nozzle formed on the piezoelectric ceramic plate 2. Good.

Further, in this embodiment, the conductive member layer 3 is formed on the nozzle surface of the ink jet printer head 1 by using the wiper member 68 made of resin or fiber such as cotton.
3 and the conductive wire 34 are provided, as shown in FIG.
Wiper member 7 made of resin mixed with conductive powder
1, the conductive wire 73 may be connected to the wiper member 71 to be grounded.

Furthermore, in the present embodiment, the conductive wire 34 is always in contact with the surface of the conductive member layer 33, but the conductive wire 34 is brought into contact with the surface of the conductive member layer 33 every predetermined period. It doesn't matter.

The present invention is not limited to the embodiments described in detail above, and modifications can be made without departing from the spirit of the invention.

[0036]

As is apparent from the above description, according to the ink jet device of the present invention, the static electricity generated by sliding is discharged by the electrostatic discharge means provided on the nozzle surface of the jetting means or the wiper means. Therefore, it is possible to prevent dust from adhering to the nozzle surface of the ejection unit, prevent clogging of the nozzle, and perform stable and reliable printing at all times.

[Brief description of drawings]

FIG. 1 is a perspective view of a nozzle plate of this embodiment.

FIG. 2 is an explanatory diagram showing a boring process for a nozzle plate in the present embodiment.

FIG. 3 is a perspective view showing the vicinity of a nozzle of the inkjet printer head of this embodiment.

FIG. 4 is a perspective view showing a wiper mechanism of an inkjet printer of a modified example.

FIG. 5 is a cross-sectional view showing the configuration of a conventional inkjet printer head.

FIG. 6 is an explanatory diagram showing an operating state of a conventional inkjet printer head.

FIG. 7 is a perspective view showing a configuration of a conventional inkjet printer head.

FIG. 8 is an explanatory diagram showing a control unit of a conventional inkjet printer head.

FIG. 9 is a perspective view showing a schematic configuration of a conventional inkjet printer.

[Explanation of symbols]

 1 Inkjet Printer Head 31 Nozzle Plate 32 Nozzle 33 Conductive Member Layer 34 Conductive Wire 35 Nozzle Plate Substrate 68 Wiper Member 69 Support Member

Claims (3)

[Claims] 1. An ink jet device having an ejecting means for ejecting an ink droplet through a nozzle and a wiper means for sliding the nozzle surface of the ejecting means to clean the surface, the nozzle surface of the ejecting means or the wiper. An ink jet device, characterized in that it is provided with electrostatic discharge means for discharging static electricity generated by the sliding. 2. The electrostatic discharge means includes a conductive conductive layer provided on the nozzle surface of the spraying means, and a grounding member connected to the conductive layer. Inkjet device. 3. The wiper means includes a wiper portion formed of resin mixed with conductive powder and sliding on the nozzle surface of the spraying means, and the electrostatic discharge means is connected to the wiper portion. The inkjet device according to claim 1, further comprising a ground member.