Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
2002-09-30
2004-11-30
Nguyen, Judy (Department: 2861)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
C029S890100
Reexamination Certificate
active
06824254
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a multi-nozzle ink jet head for applying pressure to pressure chambers and ejecting ink drops from nozzles and a manufacturing method thereof, and in particular to a multi-nozzle ink jet head for which the leading out of electrodes from a row of pressure energy generators is improved and a manufacturing method thereof.
BACKGROUND ART
An ink jet recording head has nozzles, ink chambers, an ink supply system, an ink tank, and transducers; by generating pressure in the ink chambers using the transducers, ink particles are ejected from the nozzles, and characters or images are recorded on a recording medium such as paper.
For example, in well-known forms, the transducer is used a heat-generating element, or else a thin-plate-shaped piezoelectric element having the whole of one surface thereof bonded to the outer walls of an ink chamber. In the case that a piezoelectric element is used, a pulse-like voltage is applied to the piezoelectric element, thus bending the composite plate comprising the piezoelectric element and the outer walls of the ink chamber, and the displacement/pressure generated through the bending is transmitted to the inside of the ink chamber via the outer walls of the ink chamber.
A sectioned perspective view of a conventional multi-nozzle ink jet head
100
using piezoelectric elements is shown in FIG.
20
. As shown in
FIG. 20
, the head
100
is constituted from a row of piezoelectric bodies
111
, individual electrodes
112
formed on the piezoelectric bodies, a nozzle plate
114
in which are provided nozzles
113
, ink chamber walls
117
made of a metal or a resin that, along with the nozzle plate
114
, form ink chambers
115
corresponding respectively to the nozzles
113
, and a diaphragm
116
.
A nozzle
113
and a piezoelectric body
111
are provided for each ink chamber
115
, and the periphery of each ink chamber
115
and the periphery of the corresponding diaphragm
116
are connected together strongly. A piezoelectric body
111
for which a voltage has been applied to the individual electrode
112
deforms the corresponding part of the diaphragm
116
as shown by the dashed lines in the drawing. As a result, an ink drop is ejected from the nozzle
113
.
Application of voltages to each of the piezoelectric bodies
111
is carried out separately using electrical signals from a printing apparatus main body via printed circuit boards.
FIG. 21
is a drawing showing the constitution of connections between the conventional head and the printed circuit boards. In the example of
FIG. 21
, the head
100
has 8 rows and 8 columns of nozzles
113
, i.e. of piezoelectric bodies
111
and individual electrodes
112
. Corresponding to this, flexible printed circuit boards
110
are provided for connecting the driver circuitry of the apparatus to the individual electrodes
112
.
In this prior art, the individual electrodes
112
are connected to the terminals of the printed circuit boards
110
by wires
120
through wire bonding. Moreover, art in which an FPC wiring board is connected directly is also known.
Moving on, due to demands to increase printing resolution, there are demands to increase the density of the nozzle arrangement on heads. If the nozzle density is raised, then the contact spacing between terminals (internal electrodes) is reduced. For example, the nozzle density of a head using piezoelectric bodies is currently about 150 dpi, but is advancing to 180 to 300 dpi, and further to 360 dpi, and hence the contact spacing is becoming lower.
However, currently the best contact spacing with wire bonding using semiconductor manufacturing is 150 dpi, with 300 dpi contacts being developed in the case of FPC connection. If electrical connection is carried out by providing contacts on top of or near to the piezoelectric bodies
111
as conventionally, then a problem of joining of neighboring contacts (shorting) may arise. Moreover, when connecting a large number of points in a short time, the load on the piezoelectric bodies
111
becomes very high, and with thin-film piezoelectric bodies there is a risk of breakage, and hence connection is extremely problematic.
Moreover, wire bonding requires about 1 second per point, and hence if the number of points rises due to increasing the density, then the manufacturing time increases, leading to an increase in cost. For example, with the example of
FIG. 19
, there are 48 points, and hence 48 seconds would be required. Furthermore, even in the case of FPC connection, it is necessary to connect the FPC to a printed circuit board having the driving circuitry thereon, and hence it is difficult to reduce the cost.
DISCLOSURE OF THE INVENTION
It is an object of the present invention to provide a multi-nozzle inkjet head, for which connection to driving circuitry can be carried out easily even though the nozzles are arranged at a high density, and a manufacturing method thereof.
Moreover, it is another object of the present invention to provide a multi-nozzle ink jet head, for which connection to the driving circuitry is possible even though connection work is not carried out at the head part, and a manufacturing method thereof.
Furthermore, it is yet another object of the present invention to provide a multi-nozzle ink jet head, for which damage to the head can be prevented and moreover the cost can be reduced, and a manufacturing method thereof.
To attain these objects, a form of the multi-nozzle ink jet head of the present invention has a nozzle plate in which are formed a plurality of nozzles, an ink chamber forming member in which are formed a plurality of ink chambers communicating with the nozzles, energy generating parts that apply energy to the ink chambers for ejecting ink from the nozzles, and wiring patterns that are provided on the ink chamber forming member and are for applying driving signals to the energy generating parts.
A method of manufacturing a multi-nozzle ink jet head of the present invention has a step of forming energy generating parts that apply energy to ink chambers for ejecting ink from nozzles, a step of providing, on the energy generating parts, an ink chamber forming member having wiring patterns for applying driving signals to the energy generating parts, a step of forming, in the ink chamber forming member, a plurality of ink chambers communicating with the nozzles, and a step of providing, on the ink chamber forming member, a nozzle plate in which are formed the plurality of nozzles.
With the present invention, by providing wiring patterns on the ink chamber forming member, the ink chamber forming member is also used as a connecting cable. As a result, it becomes unnecessary to carry out connection at the head part, and hence connection between the head and the driving circuitry becomes easy even though the nozzle density is high, damage to the head can be prevented, and the cost of the head can be reduced.
Moreover, in a PCT application (PCT/JP/99/06960) filed on 10 Dec. 1999, the present inventors proposed a head in which piezoelectric body layers are provided even in regions other than the regions of the pressure chambers, and wiring parts from individual electrodes are provided on the piezoelectric body layers, and hence connection to the outside of the head can be carried out at a position away from the row of the piezoelectric bodies of the pressure chambers.
However, even in that proposal, a connecting cable is necessary for connecting to the external circuitry.
With the present invention, such a connecting cable is not necessary, and hence the connection to the external circuitry is simplified.
Moreover, in the multi-nozzle ink jet head of the present invention, the energy generating parts have a common electrode, energy generating layers that are provided on the common electrode in correspondence with the ink chambers, and individual electrode parts that are provided on the generating layers in correspondence with the ink chambers, and the wiring patterns have wiring patterns for the individual electrode parts, and a wir
Koike Shuji
Sakamoto Yoshiaki
Shingai Tomohisa
Armstrong Kratz Quintos Hanson & Brooks, LLP
Fuji Photo Film Co. , Ltd.
Nguyen Judy
LandOfFree
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