Incremental printing of symbolic information – Ink jet – Fluid or fluid source handling means
Reexamination Certificate
1999-12-17
2002-06-18
Vo, Anh T. N. (Department: 2861)
Incremental printing of symbolic information
Ink jet
Fluid or fluid source handling means
C347S089000
Reexamination Certificate
active
06406137
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink-jet print head for ejecting a liquid used for printing to a printing surface of a printing medium to perform printing operation and a production method of the ink-jet print head.
2. Description of Prior Art
An ink-jet printing apparatus is generally provided with a print head for ejecting an ink as a liquid used for printing. The print head, for example, as shown in
FIG. 4
, is fixed to an apparatus main body part
2
in the ink-jet printing apparatus through a support plate
8
. The print head comprises an ink ejection part
12
having a plurality of relatively small ink ejection openings for ejecting ink droplets ID to the printing surface of paper Pa and a printed circuit board
10
provided on the support plate
8
for supplying drive control signals to heaters provided in respective ink flow passages communicating with the respective ink ejection openings of the ink ejection part
12
.
A connection terminal
10
A of the printed circuit board
10
is connected to a connector
4
of the apparatus main body part
2
outputting a drive control signal group. Further, transportation direction of paper Pa is, for example, a direction along a nearly perpendicular direction to the paper surface.
In the ink ejection part
12
one connection opening
12
a
communicating with a common liquid chamber for distributing ink to respective ink flow passages is connected to an end of an ink passage
16
constituting part of a component of a liquid supply device for supplying ink to the print head. Further, in the ink ejection part
12
the other connection opening
12
b
communicating with the common liquid chamber is connected to an end of an ink passage
18
constituting part of a component of the liquid supply device.
The other ends of the ink passages
16
and
18
are respectively connected to a head side joint part
14
engaged with a main body side joint part
6
. The main body side joint part
6
has an ink passage supplied with ink from the apparatus main body part
2
.
The head side joint part
14
has a filter containing chamber communicated with an inner peripheral part of the other end of the ink passage
16
, and a filter containing chamber communicated with an inner peripheral part of the other end of the ink passage
18
. Smaller end diameters of the tapered filter containing chambers are respectively the same as diameters of the inner peripheral parts, and larger end diameters thereof are almost the same as diameters of filters as straining members contained. Each filter is to collect foreign matters such as dust in the ink.
SUMMARY OF THE INVENTION
In the thus constructed print head, there is a fear that foreign matters such as cutting debris or dust in the production process exist in the ink passages.
In the print head, for example, as shown in
FIG. 5
, in which a plurality of ink flow passages
27
are formed by adjacent partition walls
22
with predetermined intervals provided in parallel to each other in the common liquid chamber
28
, the print head is of a type in which electrothermal conversion elements
24
used for ejecting ink are provided in each ink flow passage
27
to eject ink in the direction shown by the arrow, namely, along an extension direction of the ink passage
27
through the ejection opening
26
. In this type of print head, when the common liquid chamber
28
or the ink flow passage
27
is constructed by a method of cutting such as cutting, cutting debris
23
is generated, which may exist at an inlet part (upstream side end part) of the ink flow passage
27
or in the common liquid chamber
28
.
Further, also in the print head of a type as shown in
FIG. 6
, in which in its orifice plate OP, an ejection opening
26
′ is provided at a position opposing each electrothermal conversion device
24
′ provided in each ink flow passage
27
′ , and ink is ejected through the ejection opening
26
′ , in the direction shown by the arrow, namely in a direction opposing the electrothermal conversion device
24
′, similarly to the above, there is a possibility that cutting debris
23
generated in the production of the print head remain in each ink flow passage
27
′ and the common liquid chamber
28
of the completed head.
Yet further, there is known, as shown in
FIGS. 7 and 8
, a print head having ejection openings
26
in an order of thousands. In
FIGS. 7 and 8
, same components as those shown in
FIGS. 4 and 5
are indicated with the same reference numbers, and detailed description there is omitted.
In the print head as shown in
FIGS. 7 and 8
, the ink ejection part
12
comprises a substrate
13
having electrothermal conversion devices
24
corresponding to respective ink flow passages
27
and electrically connected to the printed circuit board
10
, and a top plate
11
respectively having ejection openings
26
communicating with the respective ink flow passages
27
.
In such a print head, there may be a case that a relative position of the electrothermal conversion device
24
at the substrate
13
side is shifted with respect to the ink flow passage
27
due to a difference in thermal expansion coefficient between a material of the top plate
11
and that of the substrate
13
.
As a method for eliminating this problem, a method is proposed in which to improve a problem of thermal contraction during processing of the print head, the top plate
11
which forms the ink flow passage
27
in cooperation with the substrate
13
is, for example, insert formed with a stainless pipe
31
or the like.
In the print head thus fabricated by the above method, to obtain a structure capable of ink supply, the stainless pipe
31
is provided with a drilling hole
29
communicating with the common liquid chamber
28
at an appropriate interval, utilizing the stainless pipe
31
as a passage
33
for flowing ink in the stainless pipe
31
.
Therefore, cutting debris
23
generated during the machining may exist at. the inlet of the ink flow passage
27
and in the common liquid chamber
28
.
Such a foreign matter generated during machining may disturb ink flow at the inlet part of the ink flow passage
27
or in the common liquid chamber
28
and result in degradation of ink ejection performance. This leads to a reduction of yield of the produced print heads.
In order to remove cutting debris existing inside the print head just described, it is necessary to clean the inside of the print head. Further, in order to perform the cleaning more certainly, it is preferable to construct the print head such that the route for discharging cutting debris from the inside of the print head to the outside be appropriately selected depending on the size or the like of cutting debris existing in the inside.
It is an object of the present invention to provide an ink-jet print head capable of efficiently discharging cutting debris or the like from the inside of the print head to the outside, in which, in the production of the print head, a process is employed for cleaning the inside of the print head.
A further object of the present invention is to provide an ink-jet print head having a configuration capable of performing cleaning of the inside of the print head with ease.
In accordance with the present invention which is proposed to attain the above objects, there is provided a production method of an ink-jet print head comprising a plurality of ejection openings for ejecting a liquid, liquid flow passages for supplying the liquid to each of the plurality of ejection openings, a common liquid chamber communicating with the plurality of liquid flow passages, a first liquid passage communicating with one end of the common liquid chamber and having a diameter larger than that of the liquid flow passage, a second liquid passage communicating with the other end of the common liquid chamber and having a diameter larger than that of the liquid flow passage, and an openable/closable opening part having an opening diameter larger than that of the liquid flow
Abe Tsutomu
Aono Kiyomi
Koizumi Yutaka
Okazaki Takeshi
Omata Kouichi
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Vo Anh T. N.
LandOfFree
Ink-jet print head and production method of ink-jet print head 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 print head and production method of ink-jet print head, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ink-jet print head and production method of ink-jet print head will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2943363