Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
2001-10-01
2003-01-21
Barlow, John (Department: 2853)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
C347S065000
Reexamination Certificate
active
06508538
ABSTRACT:
This application is based on Patent Application No. 2000-302721 filed Oct. 2, 2000 in Japan, the content of which is incorporated hereinto by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a liquid ejection head for ejecting a liquid, a head cartridge provided with the same, and a liquid ejection apparatus.
2. Description of the Related Art
An ink-jet printing apparatus is equipped with an ink-jet print-head as a liquid ejection print head. As the ink-jet print head, there is generally known an edge shooter type or a side shooter type ink-jet print head.
The side shooter type ink-jet print head, for example, as shown in Japanese Patent Laid-open Publication No. 8446/1994, or FIG.
11
and
FIG. 12
, comprises a tank
8
storing a predetermined ink, and an orifice plate
2
having a plurality of ink ejection openings
2
a
i and
2
b
i (i=1 to n, n being an integer) for ejecting ink from the tank
8
, a printing element substrate
4
joined with the orifice plate
2
and having heaters (heat generation resistors)
4
a
i and
4
b
i (i=1 to n, n being an integer) as printing elements opposing the respective ink ejection openings
2
a
i and
2
b
i, and a connection member
6
for connecting the orifice plate
2
and the printing element substrate
4
and the tank
8
.
Such an ink jet print head is, for example, connectedly disposed with a predetermined height difference relative to an ink supplier for supplying ink to its tank
8
, so that its internal pressure is a predetermined negative pressure.
The tank
8
, as shown in
FIG. 12
, has an opening
8
a
for communicating the storage for storing ink
12
with a communicating passage
6
a
of the connection member
6
. The communicating passage
6
a
of the connection member
6
communicates with a common liquid chamber
2
e
in the orifice plate
2
through an ink supply opening
4
d
at a nearly central part of the printing element substrate
4
. Therefore, a supply passage
10
is formed of the opening
8
a
, communicating passage
6
a
and the ink supply opening
4
d
. With this construction, ink
12
in the tank
8
is supplied to the common liquid chamber
2
e
through the supply passage
10
along the direction shown by the arrow.
The ink supplied to the common liquid chamber
2
e
is supplied to each branched supply passage formed between the orifice plate
2
and the printing element substrate
4
. At the part opposing the ink ejection openings
2
a
i and
2
b
i in the respective branched supply passages, heaters
4
a
i and
4
b
i are formed, respectively.
The respective heaters
4
a
i and
4
b
i are controlled by drive pulse signals according to an image data representing an image to be printed from a controller (not shown). By this operation, when the respective heaters
4
a
i and
4
b
i are operative, the ink
12
is heated by the respective heaters
4
a
i and
4
b
i to be ink droplets ID by a film boiling phenomenon which are ejected to a recording surface of the printing medium.
Further, in the ink-jet print head, instead of the operation that the ink
12
is supplied to each of the respective branched supply passages of the printing element substrate
4
through the ink supply opening
4
d
at its nearly central part as described above, for example, as shown in Japanese Patent Laid-open Publication No. 305592/1998 and
FIG. 13
, it is proposed that ink is supplied from both end sides of the printing element substrate to each branched supply passage.
Referring to
FIG. 13
, the ink-jet print head comprises a tank
14
for storing ink
22
, a substrate support member
20
disposed in the tank
14
for supporting the printing element substrate
18
, and an orifice plate
16
having a plurality of ejection openings
16
a
i and
16
b
i (i=
1
to n, n being an integer) opposing the respective heater
18
a
i and
18
b
i of the printing element substrate
18
and joined to the tank
14
.
Between the heaters
18
a
i and
18
b
i of the printing element substrate
18
and the inside surface of surface on which the ejection openings
16
a
i and
16
b
i of the orifice plate
16
are formed, branched supply passages are formed which conduct the ink
22
from both end sides of the printing element substrate
18
to the respective heaters
18
a
i and
18
b
i. With this construction, similar to as described above, when the respective heaters
18
a
i and
18
b
i are operative, the ink
22
is ejected in the form of ink droplets ID through the ejection openings
16
a
i and
16
b
i.
When inks of a plurality of colors are ejected using a print head as shown in
FIG. 11
, the inside of the above tank
8
is partitioned to store inks of respective colors, for example, Yellow Y, Magenta M, and Cyan C, further, in the ink ejection openings
2
a
i and
2
b
i in the orifice plate
2
and in the heaters
4
a
i and
4
b
i of the printing element substrate
4
, areas
2
Y,
2
M and
2
C are previously set which are used according to Yellow Y, Magenta M, and Cyan C.
In such a case, when the print head is moved along the direction shown by arrow S shown in
FIG. 11
to perform printing operation with inks of respective colors, since the printing width along the arrangement direction of the ejection openings printed per one movement is decreased as compared to a case of ejecting ink of a single color, resulting in a reduction of a so-called throughput.
In such a case, for example, to prevent the reduction of the throughput, it is considered that three orifice plates
2
and printing element substrates
4
are provided in parallel. However, as a result thereof the print head is increased in size against the requirement of downsizing.
Further, when inks of a plurality of different colors are used in the constructions of the orifice plate and printing element substrate as shown FIG.
12
and
FIG. 13
, it is difficult in design to set flow rates flowing in the respective ejection opening arrays according to ejection amounts of respective inks.
SUMMARY OF THE INVENTION
In view of the above problems, it is an object of the present invention to provide a liquid ejection head for ejecting a liquid, a head cartridge provided therewith and a liquid ejection apparatus which are capable of setting respective flow rates of inks flowing in respective ejection opening arrays according to ejection amounts of respective inks without reducing a so-called throughput.
In accordance with the present invention which attains the above object, there is provided a liquid ejection head comprising a liquid ejection opening formation section in which a first group of liquid ejection openings and a second group of liquid ejection openings for ejecting a liquid are formed, an element substrate having a plurality of energy generation elements formed in opposition to the first group of liquid ejection openings and the second group of liquid ejection openings for generating energy utilized to eject a liquid from the first group of liquid ejection openings and the second group of liquid ejection openings, a first liquid supply passage formed between one end of the element substrate and an inner wall of the liquid ejection opening formation section for supplying a liquid stored in a first liquid supply source onto the energy generation element opposing the first group of liquid ejection openings, and a second liquid supply passage formed independently of the first liquid supply passage between the other end at the opposite side to one end of the element substrate and an inner wall of the liquid ejection opening formation section for supplying a liquid stored in a second liquid supply source independent of the first liquid supply source onto the energy generation element opposing the second group of liquid ejection openings.
Further, the liquid ejection head according to the present invention comprises a liquid ejection opening formation section in which a first group of liquid ejection openings and a second group of liquid ejection openings for ejecting a liquid are formed, a printing element substrate having p
Shimoda Junji
Suzuki Toru
Tsujimoto Akira
Canon Kabushiki Kaisha
Stephens Juanita
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