Information
-
Patent Grant
-
6508538
-
Patent Number
6,508,538
-
Date Filed
Monday, October 1, 200122 years ago
-
Date Issued
Tuesday, January 21, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Barlow; John
- Stephens; Juanita
Agents
- Fitzpatrick, Cella, Harper & Scinto
-
CPC
-
US Classifications
Field of Search
-
International Classifications
-
Abstract
Under the condition that common ink flow passages are formed for separately supplying inks to respective ejection opening arrays of an orifice plate, flow passage cross sectional areas of branched ink flow passages are set respectively according to ejection amounts of the respective ejection opening arrays.
Description
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 printing elements formed in opposition to the first group of liquid ejection openings and the second group of liquid ejection openings of the liquid ejection opening formation section for ejecting a liquid through the first group of liquid ejection openings and the second group of liquid ejection openings, a liquid supply passage formed inside the printing element substrate for supplying the liquid from a liquid supply source to a printing element opposing the first group of liquid ejection openings in the printing element substrate, and a liquid supply passage group comprising a plurality of liquid supply passages formed inside the printing element substrate independent of the first liquid supply passage for individually supplying liquids from a plurality of liquid supply sources to printing elements opposing the second group of liquid ejection openings in the printing element substrate.
The liquid ejection apparatus according to the present invention comprises the above liquid ejection head, moving means for moving the liquid ejection head in opposition to a recording surface of the printing medium, and a controller for controlling the printing operation of the liquid ejection head and operation of the moving means.
As can be seen from the above description, according to the liquid ejection head of the present invention, and the head cartridge provided with the same, and the liquid ejection. apparatus, since the flow passage cross sectional area of the first liquid supply passage and the flow passage cross sectional area of the second liquid supply passage are set according to ejection amounts respectively of the first liquid ejection opening array and the second liquid ejection opening array, flow rates flowing in the respective ejection opening arrays can be set without reducing a so-called throughput and according to respective ink ejection amounts.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a perspective view showing an essential part of a first embodiment of the liquid ejection head according to the present invention;
FIG. 2
is a cross sectional view in the example shown in
FIG. 1
;
FIG. 3
is a perspective view showing an essential part of the printing apparatus to which the embodiment of the liquid ejection head according to the present invention is applied;
FIG. 4
is a perspective view showing an essential part of a second embodiment of the liquid ejection head according to the present invention;
FIG. 5
is a cross sectional view in the example shown in
FIG. 4
;
FIG. 6
is a perspective view showing an essential part of a third embodiment of the liquid ejection head according to the present invention;
FIG. 7
is a perspective view including a partial cross sectional view shown along line VII—VII in
FIG. 6
;
FIG. 8
is a partial enlarged view in the example shown in
FIG. 7
;
FIG. 9
is a perspective view including a partial cross sectional view shown along line IX—IX in
FIG. 6
;
FIG. 10
is a perspective view including a partial cross sectional view shown along line X—X in
FIG. 6
;
FIG. 11
is a perspective view showing schematically the construction of a prior art print head;
FIG. 12
is a cross sectional view in the example shown in
FIG. 11
;
FIG. 13
is a cross sectional view showing schematically the construction of a prior art print head.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 3
shows an essential part of the ink-jet printing apparatus to which an example of liquid ejection head according to the present invention is applied.
The ink-jet printing apparatus shown in
FIG. 3
comprises a carriage member
32
respectively supporting two detachably mounted ink tank holders
46
, a guide shaft
30
supported at both ends of an enclosure
28
for reciprocal movably supporting the bottom of the carriage member
32
, a guide shaft
31
supported at both ends of the enclosure
28
nearly in parallel to the guide shaft
30
for reciprocal movably supporting the bottom of the carriage member
32
, a motor
40
for transmitting a drive force to a belt
36
connected to the carriage member
32
through a pulley
38
B, and a recovery processing apparatus
42
disposed at one end of the inside of the enclosure
28
for performing recovery processing to an ink ejection section which will be described later.
The belt
36
is wound on pulleys
38
A and
38
B rotatably supported on the back surface portion of the enclosure
28
at a predetermined interval. The pulley
38
B is connected to an output shaft of the motor
40
. The motor
40
is controlled by a drive control signal from a controller (not shown) so that the output shaft thereof is rotated in the forward or reverse direction. By this operation, the carriage member
32
is reciprocally moved in a range of predetermined distance from a position immediately above the recovery processing apparatus
42
while being guided by the guide shafts
30
and
31
at a predetermined timing together with the two ink tank holders
46
and ink tanks
44
and
48
which will be described later.
A connector section of the carriage member
32
is electrically connected with an end of a flexible cable
34
for supplying a drive control signal group to a print head unit which will be described later.
Further, at a lateral part of the recovery processing apparatus
42
at the inside of the enclosure
28
, a paper transportation passage for transporting a printing paper Pa as a printing medium intermittently in the direction shown in arrow F in
FIG. 3
is provided beneath the carriage member
32
.
Each ink tank holder
46
formed of a resin has a tank container for detachably containing the ink tank
44
or ink tank
48
.
The ink tank
44
and the ink tank
48
are junctioned respectively to an ink ejection section of the print head unit which will be described later.
Since the ink tank
44
and the ink tank
48
have the same structure except for the type of stored ink, the ink tank
44
will be described and description of the ink tank
48
is omitted.
The ink tank
44
is to store each of yellow ink and magenta ink, and the ink tank
48
is to store each of cyan ink and black ink.
Inside the ink tank
44
, as shown in
FIG. 2
, a tank section
50
having an ink absorbing body
54
Y impregnated with yellow ink and a tank section
52
having an ink absorbing body
54
M impregnated with magenta-ink are provided.
As the ink absorbing bodies
54
Y and
54
M, for example, a polyurethane foam is preferably used. Further, as shown in
FIG. 2
, ink supply openings
50
Y and
52
M communicating with the inside are formed corresponding to common ink flow passages
56
Y and
56
M which will be described later.
The tank section
50
and the tank section
52
are bonded with one end side of a connection member
56
forming part of the construction of the print head unit. At the other end side of the connection member
56
, an orifice plate
58
as a liquid ejection opening formation section is bonded.
Not limited to this example, the tank
50
and the tank
52
, as shown by the chain doubled-dashed line in
FIG. 1
, for supplying ink, may be of a construction in which the tanks are detachably mounted to the connection member
56
and a base
62
. That is, the tank
50
and the tank
52
may be, for example, mounted with screws to the connection member
56
and the base
62
through a predetermined sealing member.
The orifice plate
58
, as shown in FIG.
1
and
FIG. 2
, has two rows of ejection opening arrays
58
A and
58
B in parallel to each other at the flat portion. The ejection opening arrays
58
A and
58
B are provided with a plurality of ejection openings
58
a
i and
58
b
i (i=1 to n, n being an integer) formed in opposition to each other at a predetermined interval.
Between the each other opposing ejection opening arrays
58
A and
58
B, is partitioned by a central wall
58
CW protruding inside the orifice plate
58
and extending to both ends along the arrangement direction of the ejection openings. Further, between respective adjacent ejection openings
58
a
i and respective ejection openings
58
b
i are partitioned by a partition wall
58
w formed on the internal surface of the orifice plate
58
.
The orifice plate
58
may be formed of, for example, resin materials such aspolysulfone, Aramika (trademark), Upilex (trade mark) or the like. For example, when the orifice plate is made of an Aramika film with a film thickness of 50 (μm), in the orifice plate
58
, ejection openings thereof and the like may be machined by way of an excimer laser (KrF, ArF, XeCl or the like), a YAG laser or the like.
Further, at the tip of the central wall
58
CW, a nearly central part of one flat surface of the printing element substrate
60
is bonded. Both ends of shorter side of the printing element substrate
60
are junctioned to the inner surface of the connection member
56
. With this construction, a plurality of branched ink flow passages
58
p
are formed corresponding to the respective ejection openings
58
a
i and
58
b
i between one flat surface of the printing element substrate
60
and the inner surface of the orifice plate
58
. The plurality of branched ink flow passages
58
p
are communicated with common ink flow passages
56
Y and
56
M formed respectively at longer side both ends of the printing element substrate
60
.
Therefore, a first liquid supply passage is formed by the branched ink flow passage
58
p
and the common ink flow passage
56
Y, and a second liquid supply passage is formed by the branched ink flow passage
58
p
and the common ink flow passage
56
M.
In
FIG. 2
, a distance h
1
between one flat surface of the printing element substrate
60
and the inner surface of the orifice plate
58
is set according to predetermined ejection amount of each ink, for example, set to about 12 (μm). A thickness h
2
of the orifice plate
58
, that is, a depth h
2
of the respective ejection openings
58
a
i and
58
b
i is set to, for example, about 13 (μm). The distance h
1
and h
2
corresponding to the respective ejection opening arrays
58
A and
58
B are set to the same.
On one flat surface of the printing element substrate
60
, a plurality of heaters
60
a
i and
60
b
i (i=1 to n, n being an integer) as electrothermal converters as printing elements opposing the respective ejection openings
58
a
i and
58
b
i are formed in the respective branched ink flow passages
58
p
. The printing element substrate
60
is bonded on the base
62
which is bonded extending over the tanks
50
and
52
.
Both ends in the perpendicular direction to the paper surface in the base
62
are bonded to the inner surface of the connection member
56
, respectively. The plurality of heaters
60
a
i and
60
b
i are controlled according to drive control pulse signals corresponding to image data representing an image to be printed from the controller (not shown). Therefore, the ink ejection portion of the print head unit is formed by the connection member
56
, the orifice plate
58
, the printing element substrate
60
and the base
62
.
In assembling such an ink ejection portion, the plurality of heaters
60
a
i and
60
b
i are positioned with the respective ejection openings
58
a
i and
58
b
i and then the above formed orifice plate
58
is bonded to the printing element substrate
60
and the base
62
.
Next, by bonding the connection member
56
to one end surface of the orifice plate
58
, the common ink flow passages
56
Y and
56
M are formed.
Next, by performing electrical wiring between respective heaters
60
a
i and
60
b
i of the printing element substrate
60
and the signal input/output section (not shown), the ink ejection opening section is completed.
In such a construction, the ink ejection section, as shown in
FIG. 2
, when the paper Pa is in a stop state, in association with movement of the carriage member
32
, each ink droplet IDY of yellow and droplet IDM of magenta are ejected at a predetermined timing to the recording surface of the paper Pa to perform printing operation through the opening
28
a
of the enclosure
28
.
Therefore, even when inks of a plurality of ink colors are ejected by a single ink ejection section, similar to the case of ink ejection section for ejecting only a single color ink, the printing width of the ink ejection section per scan of the carriage member
32
can be maintained. Further, it is possible to eject inks of a plurality of ink colors with a high precision proximity to each other of the ejection opening arrays
58
A and
58
B. Still further, for example, even in the case of ejecting inks of four colors differing from each other, the required number of printing element substrates
60
is smaller than the prior art method, that is, two substrates will be sufficient. Yet further, since the common ink flow passages
56
Y and
56
M are formed at both ends by the longer side of the printing element substrate
60
, respectively, the cross sectional area of supply flow passage can be easily increased without relatively increasing the size of the printing element substrate
60
. As a result thereof, flexibility of changing the ink flow rate of each ink in designing is improved.
FIGS. 4 and 5
show essential part of a second embodiment of the liquid ejection print head according to the present invention. The same components as shown in
FIGS. 1 and 2
are indicated by the. same reference symbols, and detailed description thereof is omitted.
In the example shown in
FIG. 2
, the distance h
1
corresponding to the respective ejection opening arrays
58
A and
58
B is the same as each other, the cross sectional shapes of the ejection openings are same as each other. However, in the example shown in
FIGS. 4 and 5
, the distances h
1
and h
4
corresponding to respective ejection opening arrays
76
A and
76
B are different from each other, and the cross sectional shapes of the ejection openings are different from each other.
Inside the ink tank
48
, as shown in
FIG. 5
, a tank
70
having an ink absorbing body
74
C impregnated with cyan ink, and a tank
72
having an ink absorbing body
74
B impregnated with black ink are provided.
As the ink absorbing bodies
74
C and
74
B, for example, a polyurethane foam is preferably used. Further, inside the tanks
70
and
72
, as shown in
FIG. 5
, ink supply openings
70
C and
72
B communicating with the inside are formed correspondingly to the common ink flow passages
78
C and
78
B which will be described later.
To the tanks
70
and
72
, one end side of the connection member
78
as part of construction in the print head unit is bonded. To the other end side of the connection member
78
, the orifice plate
76
is bonded.
The orifice plate
76
, as shown in FIG.
4
and
FIG. 5
, has two rows of ejection opening arrays
76
A and
76
B in parallel to each other at the flat portion. The ejection opening arrays
76
A and
76
B are provided with a plurality of ejection openings
76
a
i and
76
b
i (i=1 to n, n being an integer) formed in opposition to each other at a predetermined interval. Further, in this example, the ejection openings
76
a
i and
76
b
i are different in shape and size, and the number of ejection openings of the ejection opening array
76
A is greater than the number of ejection openings of the ejection opening array
76
B.
The each other opposing ejection opening arrays
76
A and
76
B, are partitioned by a central wall
76
CW protruding inside the orifice plate
76
and extending to both ends along the arrangement direction of the ejection openings. Further, between respective adjacent ejection openings
76
a
i and between respective ejection openings
76
b
i are partitioned by a partition wall
76
w
formed on the internal surface of the orifice plate
76
.
Further, at the tip of the central wall
76
CW, a central part of one flat surface of the printing element substrate
60
is bonded. Both ends by shorter side of the printing element substrate
60
are junctioned to the inner surface of the connection member
78
, respectively. With this construction, a plurality of branched ink flow passages
76
p
are formed corresponding to nearly circular respective ejection openings
76
a
i and
76
b
i between one flat surface of the printing element substrate
60
and the inner surface of the orifice plate
76
. The plurality of branched ink flow passages
76
p
are communicated with common ink flow passages
78
C and
78
B formed respectively at both ends by longer side of the printing element substrate
60
.
In
FIG. 5
, a distance h
1
between one flat surface of the printing element substrate
60
and the inner surface of the part on which the ejection opening array
76
A of the orifice plate
76
is formed, is set according to predetermined ejection amount (30 ng) of black ink per one ejection opening, for example, set to about 25 (μm). On the other hand, a distance h
4
between one flat surface of the printing element substrate
60
and the inner surface of the part on which the ejection opening array
76
B of the orifice plate
76
is formed, is set according to a predetermined ejection amount (4.5 ng) of cyan ink per on e ejection opening, that is, smaller than the distance h
1
, for example, to about 20 (μm).
The cross sectional shape of each ejection opening
76
a
i of the ejection opening array
76
A is composed of, for example, a small-diameter part 76 ns having a diameter of about 30 (μm) and a large-diameter part 76 ng. A size h
2
in the axial direction of the small-diameter part 76 ns is set to 40 (μm), and a size h
3
in the axial direction of the large-diameter part 76 ng is set to 10 (μm). The cross sectional shape of each ejection opening
76
b
i of the ejection opening array
76
B is composed of, for example, a small-diameter part 76 nm having a diameter of about 14.5 (μm) and a large-diameter part 76 nw. A size h
5
in the axial direction of the small-diameter part 76 nm is set to 25 (μm), and a size h
6
in the axial direction of the large-diameter part 76 nw is set to 35 (μm).
Therefore, the ink ejection section of the print head unit is formed of the connection member
78
, the orifice plate
76
, the printing element substrate
60
, and the base
62
.
In assembling such an ink ejection section, assembly is performed similar to the above-described example. In this case, in the orifice plate
76
, since the ejection opening array of relatively large in ejection amount requires more ink supply amount compared to ejection opening array of relatively small ejection amount, the height h
1
of the branched flow passage which is to be equal in flow passage width to each other is machined to be larger compared to the height h
4
of the branched flow passage.
In such a construction, the ink ejection section, when the paper Pa is in a stop state, in association with movement of the carriage member
32
, ejects each ink droplet IDB and IDC of black or cyan at a predetermined timing to the recording surface of the paper Pa through the opening
28
a
of the enclosure
28
to perform printing operation.
Therefore, for ejection of black ink required to have relatively high throughput, a relatively large ejection amount can be obtained, and, for ejection of color ink such as cyan required to have high image quality, a relatively small ejection amount can be obtained. Here, for black ink ejection, an ejection method is used in which a bubble generated by heat generated by the electrothermal converter is defoamed, and for color ink ejection, an ejection method is used in which a bubble generated by heat generated by the electrothermal converter communicates with the atmosphere. As a result thereof, flow rates flowing into respective ejection opening arrays can be set according to ejection amounts of respective inks without reducing a so-called throughput.
FIG. 6
shows part of a third embodiment of the liquid ejection print head according to the present invention.
In the above-described example, it is constructed so that the ink tank and the ink ejection section are integrally formed, however, in the example shown in
FIG. 6
, the ink ejection section
90
is provided separately from the ink tank.
In
FIG. 6
, the ink ejection section
90
comprises an orifice plate
92
having ejection opening arrays
92
A and
92
B and a printing element substrate
94
on which respective heaters, which will be described later, are formed on the surface corresponding to the ejection opening arrays
92
A and
92
B of the orifice plate
92
. Outer dimensions of the ink ejection section
90
are, for example, about 30×45×20 (mm).
The orifice plate
92
, as shown in
FIG. 7
, is provided with the ejection opening arrays
92
A and
92
B parallel to each other formed in two rows at nearly central part. In the ejection opening arrays
92
A and
92
B, a plurality of ejection openings
92
a
i and
92
b
i (i=1 to n, n being an integer) are formed at a predetermined interval. Between the ejection opening arrays
92
A and
92
B is partitioned by a central partition wall
92
CW protruding inside and extending along the arrangement direction of the ejection openings
92
a
i and
92
b
i.
At the ejection opening array
92
A side in the central partition wall
92
CW, a recess
92
CPB supplied with black ink is formed which will be described later. Further, at the ejection opening array
92
B side in the central partition wall
92
CW, as shown in FIG.
8
and
FIG. 9
, recesses
92
CPY,
92
CPM, and
92
CPC supplied respectively with yellow ink, magenta ink, and cyan ink are dividedly formed which will be described later.
Between adjacent ejection openings
92
a
i and between adjacent ejection openings
92
b
i, as shown in
FIG. 8
, is partitioned by a partition wall
92
w
. Therefore, the respective branched flow passages formed by a pair of partition walls
92
w
communicate with the recess
92
CPB or the respective recesses
92
CPY,
92
CPM, and
92
CPC.
At both ends by shorter side of the orifice plate
92
, as shown in
FIG. 6
, recesses
92
a
and
92
b
for performing relative positioning to a support member (not shown) and injection openings
92
d
and
92
e
injected with a sealing adhesive are formed.
At one end of respective ink supply passages opening at one side of the printing element substrate
94
, one ends of tubes TY, TM, TC and TB for supplying respective inks are connected. For example, the other ends of tubes TY, TM, TC and TB of inner diameter of 1.5 mm are connected to the ink tank unit (not shown) disposed with a predetermined height difference from the ink ejection section. In the ink tank unit, yellow ink, magenta ink, cyan ink and black ink are stored in an amount of 100 ml each in divided small chambers. The yellow ink, magenta ink, cyan ink and black ink are supplied to ink supply passages
94
PY,
94
PM,
94
PC and
94
PB through the ink supply tubes TY, TM, TC and TB.
The other ends of the ink supply passages
94
PY,
94
PM,
94
PC and
94
PB, as shown in FIG.
9
and
FIG. 10
, communicate with recesses
94
CPY,
94
CPM,
94
CPC and
94
CPB formed in opposition to the respective recesses
92
CPY,
92
CPM,
92
CPC and
92
CPB of the orifice plate
92
in the printing element substrate
94
. With this construction, yellow ink, magenta ink, cyan ink are supplied to the respective common liquid chambers formed integrally with the respective recesses
92
CPY,
92
CPM, and
92
CPC and recesses
94
CPY,
94
CPM, and
94
CPC. Further, as shown in
FIG. 10
, a common liquid chamber formed integrally with the recesses
92
CPB and
94
CPB is supplied with black ink. Therefore, the ejection opening array
92
A is to eject only black ink, on the other hand, the ejection opening array
92
B is to eject yellow ink, magenta ink and cyan ink in a predetermined ratio corresponding to the volumes of the recesses
94
CPY,
94
CPM, and
94
CPC.
Further, in the part opposing the ejection opening arrays
92
A and
92
B of the orifice plate
92
in the printing element substrate
94
, heaters
94
a
i and
94
b
i (i=1 to n, n being an integer) corresponding to the respective ejection openings and respective branched flow passages are formed. A distance (height of partition wall) from the surface where the heaters
94
a
i and
94
b
i in the respective branched flow passages are formed to the inner surface of the orifice plate
92
is to be equal to each other in the ejection opening arrays
92
A and
92
B.
With this construction, the ink ejection section of the print head unit, when the paper Pa is in a stop state, in association with movement of the carriage member
32
, each ink droplet of yellow ink, magenta ink, cyan ink, and black ink is ejected through the opening
28
a
of the enclosure
28
at a predetermined timing to the recording surface of the paper Pa to perform printing operation.
Therefore, when inks of a plurality of colors are ejected by a single ink ejection section
90
while moving along the direction shown by arrow S in
FIG. 6
, when a throughput is required to be maintained for black ink printing, since for black ink, printing width by a single scan is the maximum width corresponding to the arrangement length of the ejection opening, as shown in
FIG. 11
, a reduction in so-called throughput is prevented compared to the prior art case in which the ejection opening array is dividedly used for respective colors.
In the above-described example, inks of a plurality of different colors are used, however, the present invention is not limited to such an example, but inks of a plurality of shades differing in ink concentration may be used.
The present invention has been described in detail with respect to preferred embodiments, and it will now be apparent from the foregoing to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and it is the intention, therefore, in the appended claims to cover all such changes and modifications as fall within the true spirit of the invention.
Claims
- 1. A liquid ejection head comprising:a liquid ejection opening formation section in which a first group of liquid ejection openings for ejecting a first liquid and a second group of liquid ejection openings for ejecting a second liquid are formed; an element substrate having a plurality of energy generation elements formed corresponding to said first group of liquid ejection openings and said second group of liquid ejection openings for generating energy utilized to eject said first liquid from said first group of liquid ejection openings and to eject said second liquid from said second group of liquid ejection openings; a first liquid supply passage formed between one end of said element substrate and an inner wall of said liquid ejection opening formation section for supplying the first liquid stored in a first liquid supply source to said energy generation elements corresponding to said first group of liquid ejection openings; and a second liquid supply passage formed independently of said first liquid supply passage between an other end of said element substrate at a side opposite said one end and said inner wall of said liquid ejection opening formation section for supplying the second liquid stored in a second liquid supply source independent of said first liquid supply source to said energy generation elements corresponding to said second group of liquid ejection openings, wherein a flow passage cross-sectional area of said first liquid supply passage and a flow passage cross-sectional area of said second liquid supply passage are different from each other.
- 2. The liquid ejection head as claimed in claim 1, wherein the first liquid stored in said first liquid supply source and the second liquid stored in said second liquid supply source are different in type from each other.
- 3. The liquid ejection head as claimed in claim 2, wherein a cross sectional area of each of said first branched liquid flow passages for conducting the first liquid to said first group of liquid ejection openings and a cross sectional area of each of said second branched liquid flow passages for conducting the second liquid to said second group of liquid ejection openings are different from each other.
- 4. The liquid ejection head as claimed in claim 2, wherein the first liquid and the second liquid are inks differing in ink color or concentration from each other.
- 5. The liquid ejection head as claimed in claim 1, wherein said first liquid supply passage comprises a first common liquid flow passage for conducting the first liquid from said first liquid supply source and first branched liquid flow passages for conducting the first liquid from said first common liquid flow passage to said first group of liquid ejection openings, and said second liquid supply passage comprises a second common liquid flow passage for conducting the second liquid from said second liquid supply source and second branched liquid flow passages for conducting the second liquid from said second common liquid flow passage to said second group of liquid ejection openings.
- 6. A liquid ejection apparatus comprising:the liquid ejection head of claim 1; moving means for moving said liquid ejection head in correspondence with a recording surface of a printing medium; and a controller for controlling printing operation of said liquid ejection head and operation of said moving means.
- 7. A head cartridge comprising the liquid ejection head of claim 1, wherein said first liquid supply source and said second liquid supply source are detachably mounted to said liquid ejection head.
- 8. A liquid ejection head comprising:a liquid ejection opening formation section in which a first group of liquid ejection openings for ejecting a first liquid and a second group of liquid ejection openings for ejecting a second liquid are formed; an element substrate having a plurality of energy generation elements formed corresponding to said first group of liquid ejection openings and said second group of liquid ejection openings for generating energy utilized to eject said first liquid from said first group of liquid ejection openings and to eject said second liquid from said second group of liquid ejection openings; a first liquid supply passage formed between one end of said element substrate and an inner wall of said liquid ejection opening formation section for supplying the first liquid stored in a first liquid supply source to said energy generation element corresponding to said first group of liquid ejection openings; and a second liquid supply passage formed independently of said first liquid supply passage between an other end of said element substrate at a side opposite said one end and said inner wall of said liquid ejection opening formation section for supplying the second liquid stored in a second liquid supply source independent of said first liquid supply source to said energy generation elements corresponding to said second group of liquid ejection openings, wherein a cross-sectional area of each ejection opening of said first group of liquid ejection openings and a cross-sectional area of each ejection opening of said second group of liquid ejection openings are different from each other.
- 9. A liquid ejection head comprising:a liquid ejection opening formation section in which a first group of liquid ejection openings for ejecting a first liquid and a second group of liquid ejection openings for ejecting a second liquid are formed; an element substrate having a plurality of energy generation elements formed corresponding to said first group of liquid ejection openings and said second group of liquid ejection openings for generating energy utilized to eject said first liquid from said first group of liquid ejection openings and to eject said second liquid from said second group of liquid ejection openings; a first liquid supply passage formed between one end of said element substrate and an inner wall of said liquid ejection opening formation section for supplying the first liquid stored in a first liquid supply source to said energy generation elements corresponding to said first group of liquid ejection openings; and a second liquid supply passage formed independently of said first liquid supply passage between an other end of said element substrate at a side opposite said one end and said inner wall of said liquid ejection opening formation section for supplying the second liquid stored in a second liquid supply source independent of said first liquid supply source to said energy generation elements corresponding to said second group of liquid ejection openings, wherein a distance between said inner wall of said liquid ejection opening formation section and any of said energy generation elements opposing one of said ejection openings of said first group of liquid ejection openings and a distance between said inner wall of said liquid ejection opening formation section and any of said energy generation elements opposing one of said ejection openings of said second group of liquid ejection openings are different from each other.
- 10. 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 first liquid and a second liquid are formed; a printing element substrate having printing elements formed corresponding to said first group of liquid ejection openings and said second group of liquid ejection openings of said liquid ejection opening formation section for ejecting the first liquid and the second liquid through said first group of liquid ejection openings and said second group of liquid ejection openings; a first liquid supply passage formed inside said printing element substrate for supplying the first liquid from a first liquid supply source to said printing elements corresponding to said first group of liquid ejection openings in said printing element substrate; and a liquid supply passage group comprising a plurality of second liquid supply passages formed inside said printing element substrate independent of said first liquid supply passage for individually supplying the second liquid from a plurality of second liquid supply sources to printing elements corresponding to said second group of liquid ejection openings in said printing element substrate.
- 11. The liquid ejection head as claimed in claim 10, wherein the first liquid and the second liquid are ink.
- 12. The liquid ejection head as claimed in claim 10, wherein said liquid ejection opening formation section is formed of a resin material and said first group of liquid ejection openings and said second group of liquid ejection openings are formed by laser machining.
- 13. The liquid ejection head as claimed in claim 10, wherein said printing elements of said printing element substrate are electrothermal converters.
- 14. The liquid ejection head as claimed in claim 10, wherein a flow passage cross sectional area of said first liquid supply passage and a flow passage cross sectional area of said liquid supply passage group differ from each other in accordance with ejection amounts of said first group of liquid ejection openings and said second group of liquid ejection openings, respectively.
- 15. A liquid ejection apparatus comprising:the liquid ejection head of claim 10; moving means for moving said liquid ejection head in correspondence with a recording surface of a printing medium; and a controller for controlling printing operation of said liquid ejection head and operation of said moving means.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2000-302721 |
Oct 2000 |
JP |
|
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
5635966 |
Keefe et al. |
Jun 1997 |
A |
6234622 |
Liu et al. |
May 2001 |
B1 |
Foreign Referenced Citations (2)
Number |
Date |
Country |
10-305592 |
Nov 1998 |
JP |
2000-302721 |
Oct 2000 |
JP |