Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
2003-02-14
2004-11-30
Nguyen, Thinh (Department: 2861)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
C347S071000
Reexamination Certificate
active
06824243
ABSTRACT:
This application claims priority from Japanese Patent Application No. 2002-039247 filed Feb. 15, 2002, which is incorporated hereinto by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a liquid jet print head and a liquid jet printing apparatus with the same.
2. Description of the Related Art
Liquid jet printing apparatuses with liquid jet print heads are well known. In such a liquid jet printing apparatus, print liquid (ink) is supplied to the liquid jet print head having printing devices such as electrothermal converting elements and piezoelectric elements, and electric pulse signals corresponding to image data are sent to the printing devices. Then, the liquid jet print head ejects print liquid to print desired images on a print medium. As has been described, so called non-impact type liquid jet printing apparatuses can print images on various print media at high speed with low noise. Thus, they are widely adopted as printers, word processors, facsimile, copiers and mailing machines.
FIGS. 20 and 21
show a conventional print head for the liquid jet printing apparatus. The liquid jet print head
100
shown in these drawings has a plurality of electrothermal converting elements (not shown) serving as printing devices. The print head prints images on a print medium by ejecting ink drops from micro nozzles corresponding to each of electrothermal converting elements. Electrothermal converting elements (heaters) for generating heat are arranged on a printing device substrate
101
. Also, and a plurality of nozzles
101
a
corresponding to the electrothermal converting elements are arranged on the printing device substrate
101
. As shown in
FIG. 21
, the printing device substrate
101
is bonded to a supporting substrate
102
made of aluminum, ceramics and the like.
On the supporting substrate
102
, wiring sheets
103
such as TAB and FPC are bonded so as to supply electric signals to the printing device substrates
101
. Each printing device substrate
101
is electrically connected with the wiring sheet
103
by wire bonding or lead bonding. The wiring sheets
103
are connected to a contact substrate
105
such as PWB, TAB and FPC having a plurality of contact pads
104
for electric connection with the liquid jet printing apparatus (not shown). The printing device substrates
101
and contact substrate
105
are connected with a flow path forming member
106
having flow paths
106
a
for print liquid.
A liquid jet print head shown in
FIGS. 22 and 23
is also well known The liquid jet print head
200
of these drawings includes a printing unit
201
(
FIG. 22
) for producing ink drops and a print liquid storage unit
220
(
FIG. 23
) for supplying print liquid to the printing unit
201
. The printing unit
201
includes a printing device substrate
203
where a plurality of printing devices (electrothermal converting elements)
202
that generate energy for ejecting ink drops are arranged. The printing device substrate
203
is bonded to a supporting substrate
204
made of aluminum, ceramics and the like.
Further, a wiring substrate
205
that provides an electric connection with the liquid jet printing apparatus is mounted on the supporting substrate
204
in addition to the printing device substrate
203
. The printing device substrate
203
and the wiring substrate
205
are electrically connected with each other by wire bonding or lead bonding. On the printing device substrate
203
, shift registers for driving and wiring patterns are formed in addition to the printing devices
202
, and they are all formed together with the printing devices
202
on the printing device substrate
203
by silicon device techniques. Contact pads (not shown) are formed on the wiring substrate
205
for electric coupling with the liquid jet printing apparatus.
On the top surface of the printing device substrate
203
, a ceiling plate
207
having concave portions is bonded by a pressing means such as a plate spring
206
or with an adhesive. As a result, a liquid chamber
208
and liquid flow paths
209
are formed between the printing device substrate
203
and the ceiling plate
207
. An orifice plate
210
is aligned and bonded to the end faces of the printing device substrate
203
and the ceiling plate
207
. As shown in
FIG. 22
, the orifice plate
210
has a number of micro nozzles
210
a
for ejecting ink drops in positions corresponding to the each of printing devices
202
on the printing device substrate
203
.
A flow path forming member
212
has a flow path for print liquid and is fixed to the supporting substrate
204
. The flow path of the member
212
communicates with an inlet
207
a
formed on the top of the ceiling plate
207
. Through the inlet, print liquid is supplied to the liquid chamber
208
formed between the printing device substrate
203
and the ceiling plate
207
. The flow path forming member
212
has a porous member
214
faced with the contact area with the ceiling plate
207
, and the porous member
214
traps impurities contained in print liquid.
On the other hand, as shown in
FIG. 23
, the print liquid storage unit
220
includes a frame
221
having a liquid chamber (not shown) for storing print liquid therein. The frame
221
serves as a casing that holds the printing unit
201
. The printing unit
201
is fixed to the frame
221
with screws
222
or an adhesive. Their contact portion is sealed with a predetermined sealing agent to be airtight. In the liquid jet print head
200
, the print liquid stored in the liquid chamber of the frame
221
is sent to the printing device substrate
203
via the flow path forming member
212
and the ceiling plate
207
.
As seen from
FIGS. 20 and 21
, the liquid jet print head
100
has a structure where a plurality of printing device substrates
101
are bonded to a single supporting substrate
102
. On the other hand, as seen from
FIGS. 22 and 23
, the liquid jet print head
200
has a structure where a single-piece printing device substrate
203
is bonded to the supporting substrate
204
. That is, some liquid jet print heads have a structure where a single-piece printing device substrate is bonded to the supporting substrate, and others have a structure where a plurality of printing device substrates are bonded to the supporting substrate. Some of the liquid jet printing apparatuses using the liquid jet print head having only a single-piece printing device substrate have a single liquid jet print head, and others have more than one liquid jet print head.
When the electrothermal converting element receives an electric pulse signal serving as a print signal, the electrothermal converting element provides thermal energy with print liquid. Then, the liquid jet print head utilizes the pressure of bubbles formed by film boiling in print liquid caused by the thermal energy so as to eject ink drops. Some of the liquid jet print heads using electrothermal converting elements eject print liquid in the direction parallel to the substrate where the electrothermal converting elements are arranged (so called, edge shooters, see FIG.
22
), and others eject print liquid in the direction perpendicular to the substrate where the electrothermal converting elements are arranged (so called, side shooters).
If a printing device substrate in such a liquid jet print head is excessively heated during operation, there may be problems to the electric pulse signals and to the bubbling state of print liquid. Thus, some heat-dissipating mechanisms are usually provided with the liquid jet print head. For example, in the edge-shooter type liquid jet print head, the supporting substrate disposed on the backside of the silicon printing device substrate is made of aluminum, aluminum alloys or ceramics so that it serves as a heat-dissipating member.
On the other hand, in the side-shooter type liquid jet print head, such a simple method is known that dissipates heat by using print liquid itself ejected from the print liquid storage unit via the back side of the printing device substrate. In sid
Koizumi Yutaka
Umeyama Mikiya
Yamaguchi Yukuo
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Nguyen Thinh
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