JP2002001944A - Ink jet head of shearing mold type - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cover plate which can seal an air channel and supply ink effectively for an ink jet head of shearing mold type having the air channel, and make it possible to mass-produce the ink jet head. SOLUTION: The ink jet head of shearing mold type has an air channel besides an ink channel and a cover plate cut off from a rectangular block made of ceramics having holes for ink inlet attached on the head. The air channel is formed so as to be sealed with the ink channel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a shear mode ink jet head suitable for high-speed recording and advantageous for mass production.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 63-25 / 1988 discloses one type of a drop-on-demand type ink jet printing apparatus.
No. 2,750, JP-A-6-234212, JP-A-6-234216, and the like are known to be advantageous for miniaturization and high-speed operation.

[0003] This is achieved by utilizing a piezoelectric thickness-shear deformation of a partition wall of an ink channel formed in a piezoelectric ceramic.
First, a pressure is applied to expand the ink channel volume to supply ink into the channel, and then a pressure is applied to reduce the channel volume to eject ink droplets from the nozzles.

At this time, since the pressure applied to discharge the ink remains and vibrates even after the ink is discharged, the ink pressure in the nozzle fluctuates, and the ink meniscus vibrates. When this vibration is repeated several times, it gradually attenuates and the next ejection becomes possible.

However, when ink is ejected from one ink channel, the ejection pressure is also transmitted to the adjacent ink channel and the ink meniscus oscillates even in a non-ejection nozzle, so that there is a limit to the speeding up of recording.

In order to increase the recording speed, Japanese Patent Application Laid-Open No.
It is known to provide air chambers (air channels) alternately formed adjacent to ink channels as described in JP-A No. 2596 and JP-A-7-214778.

[0007]

The ink channel and the air channel can adopt various shapes, lengths, and volumes of the ink channel and the air channel depending on the physical properties of the ink used and the manner of controlling the ejection, but ink leaks into the air channel. When the air channel and the ink channel are almost the same length or the air channel is longer, it is necessary to seal the ink channel so that no ink is supplied and supply ink only to the ink channel.
As shown in (1), it is necessary to seal the ink channel with a cover plate provided with an ink supply port only in the ink channel portion.

In FIG. 1, 1 is a piezoelectric ceramic substrate, 2 is a nozzle plate, 3 is a nozzle, 4 is an ink channel, 5 is a side wall, 6 is an air channel, 7 is a cover plate, and 8 is an ink supply port.

An ink channel 4 and an air channel 6 each having the same shape and formed by cutting with a diamond blade or the like are formed in parallel on the piezoelectric ceramic substrate 1, and the side wall 5 serving as the side surface of each channel is polarized in the direction of the arrow. Have been. The depth of each channel gradually decreases as approaching one end face 12 of the piezoelectric ceramic substrate,
The shallow groove 10 is formed near the end face 12. On the inner surface of each channel, a metal electrode 9 is formed on the upper half of both side surfaces by sputtering or the like. On the inner surface of the shallow groove 10, a metal electrode 11 is formed on the side and bottom surfaces thereof by sputtering or the like.
1 is communicating. The drawing shows the case where the lengths of the ink channel and the air channel are the same.

As described above, since the shear mode ink jet head utilizes the piezoelectric shear deformation of the partition walls of the ink channels formed on the piezoelectric ceramic substrate 1, the cover plate 7 has strength against deformation and the like. Therefore, the ink supply port 8 is formed by grinding or cutting. Then, the surface of the piezoelectric ceramic substrate 1 where the channels are processed and the cover plate 7 are adhered using an epoxy-based adhesive or the like, and the upper surface is covered with the cover plate 7 to form the ink channel 4 and the air channel 6.

The nozzle plate 2 provided with the nozzles 3 at the positions corresponding to the positions of the respective ink channels 4 is bonded to the end faces of the piezoelectric ceramic substrate 1 and the cover plate 7. The nozzle plate is formed of a plastic such as polyalkylene terephthalate such as PET, polyimide, polyether imide, polyether ketone, polyether sulfone, polycarbonate, or cellulose acetate.

In practice, the cover plate is thinner than 1 mm, and the width of the ink channel is several μm to several tens μm.
However, since the ink supply port is a very fine hole, it is very difficult to apply such a processing to a ceramic thin plate, which hinders mass production.

The present invention has been made in view of the above circumstances, and an object of the present invention is to seal and supply ink to an ink channel of an air channel of a shear mode ink jet head having an air channel. Another object of the present invention is to provide a cover plate that can be easily manufactured and mass-produce the inkjet head.

[0014]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cover plate cut out from a rectangular ceramic block having an air channel provided in parallel with an ink channel and having a hole for an ink inlet. A shear mode ink jet head in which an air channel is sealed with respect to an ink channel; and a first rectangular block in which a hole for an ink inlet of a ceramic rectangular block is finely slit on one surface. The surface to which the nozzle plate is bonded after the air channel is sealed with respect to the ink channel by bonding the cover plate, which is formed by bonding the surface and the smooth surface of the second rectangular block. This is achieved by being formed through the step of being cut by.

That is, the inventor of the present invention has found that it is difficult to improve the precision by piercing the ink introduction port on a thin plate. The inventors have found that not only the difficulty of processing but also the productivity can be improved, and the present invention has been accomplished.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the production will be described below, but the present invention is not limited to these embodiments.

First, as shown in FIG. 2, a second rectangular block 21 is formed on a first rectangular block 21 in which a slit 22 is formed using a dicing saw or a diamond blade.
3, 23 'are bonded using an epoxy-based adhesive or the like so that no gap is formed on the mating surfaces. The adhesive may be applied by dispenser application, screen application, or the like, and adhered by pressing and heating, and the protruding adhesive may be removed by grinding, plasma treatment, or the like. Further, a glue guard may be provided at a position where the sealing performance is not hindered.
In order to apply the adhesive uniformly, the mating surface may be surface-treated by UV treatment, plasma treatment, or the like, or a primer layer may be formed.

Next, as shown in FIG. 3, the surface is sliced by a wire saw or the like, and the surface to be bonded to the piezoelectric ceramic substrate is smoothed by lapping or the like to obtain a cover plate member 31 for two heads. .

FIG. 4 is a model diagram showing a process of bonding the cover plate member 31 to a piezoelectric ceramic substrate 41 in which the ink channel 4 and the air channel 6 are grooved and the nozzle forming surface 42 is not cut. The channel portion is shown as a cross section. In FIG. 2, a perforation 43 for the ink inlet formed by bonding the slit 22 and the rectangular block to each other is formed in the shallow groove 10 of the ink channel.
The cover plate member 31 is aligned such that the shallow groove of the air channel is sealed with respect to the ink channel between the partition walls, and bonding is performed in the same manner as the bonding between the rectangular blocks. Next, it is cut at the cutting position indicated by the line AA 'to form the nozzle forming surface 42, and two head members are obtained.

Here, the perforations for the ink introduction port are formed by laminating rectangular blocks, but may be perforated directly in one block. Also, after bonding a piezoelectric ceramic substrate and a cover plate member in such a form that not only two but also a plurality of heads can be obtained, individual heads may be obtained by cutting, or individual heads may be obtained in advance. The cover plate according to the present invention may be bonded as a ceramic substrate.

[0021]

According to the present invention, it is possible to mass-produce a shear mode type ink jet head in which an ink channel and an air channel are reliably separated.

[Brief description of the drawings]

FIG. 1 is a diagram showing one configuration of a shear mode ink jet head having an air channel.

FIG. 2 is a model diagram for explaining a process according to the invention of claim 2;

FIG. 3 is a model diagram showing cutout of a cover plate member according to the present invention.

FIG. 4 is a model diagram showing bonding of a piezoelectric ceramic substrate and a cover plate member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric ceramic substrate 2 Nozzle plate 3 Nozzle 4 Ink channel 5 Side wall 6 Air channel 7 Cover plate 8 Ink supply port 9, 11 Metal electrode 10 Shallow groove

Claims (3)

[Claims] 1. A cover plate cut out from a ceramic rectangular block having an air channel provided in parallel with an ink channel and having a hole for an ink introduction port is bonded, and the air channel is sealed with respect to the ink channel. A shear mode type ink jet head characterized by being formed by: 2. The ceramic rectangular block has a perforation for an ink inlet formed by laminating the processed surface of a first rectangular block having a fine slit formed on one surface and a smooth surface of a second rectangular block. The shear mode ink jet head according to claim 1, wherein the head is formed. 3. The method according to claim 3, wherein the air channel is sealed off from the ink channel by laminating the cover plate, and then is cut through a surface to which the nozzle plate is laminated. Item 3. The shear mode ink jet head according to item 1 or 2.