Incremental printing of symbolic information – Ink jet – Ejector mechanism
Utility Patent
1997-12-10
2001-01-02
Barlow, John (Department: 2853)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
C156S290000, C347S029000
Utility Patent
active
06168255
ABSTRACT:
This application is a PCT/JP96/01588 filed Jun. 12, 1996.
TECHNICAL FIELD
The present invention relates to an ink jet head for changing the volume in a pressure chamber by deformation of a laminate piezoelectric device and for jetting ink filled in the pressure chamber from the front openings of the pressure chamber through nozzle holes, particularly to an ink jet head which is characterized by an adhesive layer interposed between the front end surface of the main body forming the pressure chamber and a nozzle plate, a method of manufacturing the same, and a jig for manufacturing the ink jet head.
BACKGROUND TECHNOLOGY
A conventional ink jet head of this type is, for example, disclosed in the laid-open publication of JP-A 3-173651.
FIG. 8
shows the entire structure of the ink jet head as disclosed in the same publication, wherein a nozzle forming member
102
is bonded to a piezoelectric converter
101
fixedly secured onto a base member
100
by an adhesive
103
.
The base member
100
, the piezoelectric converter
101
and the nozzle forming member
102
are respectively incorporated in a frame
104
, wherein an ink chamber
105
is formed in an intermediate portion between the piezoelectric converter
101
and the nozzle forming member
102
. Ink
106
filled in the ink chamber
105
is discharged from nozzle holes
107
by deformation of the piezoelectric converter
101
.
FIG. 9
is an enlarged sectional view showing in detail a construction of a bonding part between the piezoelectric converter
101
and the nozzle forming member
102
and the periphery thereof shown in FIG.
8
. The piezoelectric converter
101
and the nozzle forming member
102
are bonded to each other by the adhesive
103
including space restriction particles
110
and conductive particles
111
. Each of the space restriction particles
110
has a uniform grain size. A given gap, namely, the ink chamber
105
, is formed between the piezoelectric converter
101
and the nozzle forming member
102
by the space restriction particles
110
.
Meanwhile, the ink jet head as disclosed in the publication of JP-A 3-173651 has a structure that the end part of the nozzle forming member
102
is bonded to the piezoelectric converter
101
, and the ink chamber
105
having a given interval is formed between the piezoelectric converter
101
and the nozzle forming member
102
as is evident from FIG.
9
.
If the bonding spot of the nozzle forming member
102
is limited to the end part alone as set forth above, it is not necessary to consider any harmful effect like the nozzle holes
107
being blocked owing to the expansion of the adhesive
103
. Accordingly, there is no description in publication JP-A 3-173651 regarding the amount of coating of the adhesive
103
.
However, the amount of coating of the adhesive becomes a problem, for example, in the case where an entire back surface of a nozzle plate
201
is bonded to an end surface
200
a
of a piezoelectric module
200
in the ink jet head shown in FIG.
10
.
That is, if the adhesive is coated onto the entire surfaces between the bonding surfaces of the end surface
200
a
of the piezoelectric module
200
and the nozzle plate
201
, excess adhesive inevitably expands to the periphery thereof. Particularly, when the adhesive enters gaps
202
forming the ink chamber, there is a likelihood that the discharge characteristic of the ink will be deteriorated or nozzle holes
203
will be blocked.
The laid-open publication of JP-A 5-220966 discloses a method of preventing the ink chamber and the nozzle holes from being blocked by the expansion of the excess adhesive set forth below.
That is, a method of manufacturing the ink jet head disclosed in the same publication comprises supplying an adhesive
302
to a recessed plate
300
having a recessed part
301
as shown in
FIG. 11A
, then scraping off the excess adhesive
302
which bulges onto the recessed plate
300
by a blade
303
as shown in
FIG. 11B
, thereby leaving the adhesive
302
in the recessed part
301
alone.
Successively, the end surface (bonding surface of the nozzle plate)
200
a
of the piezoelectric module
200
is pressed against the recessed part
301
, and then the piezoelectric module
200
is extracted thereafter so that a small amount of adhesive
302
is uniformly coated onto the end surface
200
a
of the piezoelectric module
200
, as shown in FIG.
11
C.
In such a manner, the method prevents the expansion of the excess adhesive
302
by bonding the nozzle plate
201
to the end surface
200
a
of the piezoelectric module
200
onto which the adhesive
302
is coated.
However, even in the method of manufacturing the ink jet head disclosed in the above-mentioned publication, there is a high possibility that the adhesive
302
filled in the bonding surfaces contains bubbles at random since the adhesive
302
is coated onto the entire bonding surfaces of the piezoelectric module
200
and the nozzle plate
201
.
If the adhesive
302
hardens while it contains bubbles, hermeticity between the piezoelectric module
200
and the nozzle plate
201
is not maintained depending on the condition or position of the bubbles, thereby leading to a danger that ink leakage will occur and an electrode of the piezoelectric module
200
will be short-circuited.
The present invention has been made in view of these circumstances, and it is an object of the invention to bond between the front end surface of the main body and the nozzle plate strongly with high hermeticity, and to prevent the nozzle holes from being blocked by the expansion of the adhesive.
DISCLOSURE OF THE INVENTION
To achieve the above object, the ink jet head of the present invention is characterized in being structured as follows.
That is, the ink jet head comprises a main body for changing the volume in a pressure chamber by deformation of a laminate piezoelectric device, and feeding ink filled in the pressure chamber toward front openings of the pressure chamber, a nozzle plate having nozzle holes communicating with the front openings of the pressure chamber, and an adhesive layer formed between the front end surface of the main body and the nozzle plate by an adhesive.
The adhesive layer formed between the main body of the ink jet head and the nozzle plate comprises a nozzle seal layer of an arbitrary width in such a manner as to encompass the nozzle holes and the periphery of the front openings of the pressure chamber, an outer periphery hermetic layer of an arbitrary width being formed annularly around the outer periphery of a region in which the main body and the nozzle plate oppose each other, and a reinforcing layer being distributed in an intermediate portion between the nozzle seal layer and the outer periphery hermetic layer.
Since the nozzle holes and the front openings of the pressure chamber are sealed by the nozzle seal layer in the present invention having the construction set forth above, it is possible to prevent ink from leaking from the nozzle holes and the front openings.
Further, a sealing property can be further enhanced by the outer periphery hermetic layer, and particularly entrance of moisture, dust, etc., from the outside can be prevented. Still further, a large bonding strength can be secured by the reinforcing layer.
Further, a plurality of spherical bodies each having an extremely small diameter may be contained in the adhesive layer according to the ink jet head of the present invention. With such a construction, the thickness of the adhesive layer can be maintained constant by the existence of the spherical bodies, and the nozzle seal layer, the outer periphery hermetic layer and the reinforcing layer can be prevented from being collapsed so as to effectively perform their functions.
Meanwhile, a method of manufacturing an ink jet head of the present invention, comprising a main body for changing the volume in a pressure chamber by deformation of a laminate piezoelectric device, and feeding ink filled in the pressure chamber toward the front openings of the pressure chamber, and a nozzle plate bonded ont
Armstrong, Westerman Hattori, McLeland & Naughton
Barlow John
Citizen Watch Co. Ltd.
Dickens C
LandOfFree
Ink jet head method of production thereof, and jig for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ink jet head method of production thereof, and jig for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ink jet head method of production thereof, and jig for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2536672