U.S. patent application number 13/222528 was filed with the patent office on 2012-02-02 for liquid container and method of manufacturing the same.
This patent application is currently assigned to SEIKO EPSON CORPORATION. Invention is credited to Akihisa WANIBE.
Application Number | 20120023871 13/222528 |
Document ID | / |
Family ID | 40593145 |
Filed Date | 2012-02-02 |
United States Patent
Application |
20120023871 |
Kind Code |
A1 |
WANIBE; Akihisa |
February 2, 2012 |
LIQUID CONTAINER AND METHOD OF MANUFACTURING THE SAME
Abstract
A method of manufacturing a liquid container having a tank
chamber, first and second communication holes communicating with
the tank chamber, and a flow channel communicating with the first
communication hole, including welding a film to one surface of the
liquid container in which openings communicating with the tank
chamber and the flow channel, respectively, are formed; filing the
tank chamber with a liquid from the second communication hole
disposed in a vertical upper portion of the tank chamber; and
delivering bubbles, which are gathered in the vertical upper
portion of the tank chamber at a time of filling the tank chamber
with the liquid, from the tank chamber to the flow channel through
a bypass channel extending from an opening of the tank chamber to
an opening of the flow channel through a non-welded portion of the
film.
Inventors: |
WANIBE; Akihisa;
(Matsumito-shi, JP) |
Assignee: |
SEIKO EPSON CORPORATION
Tokyo
JP
|
Family ID: |
40593145 |
Appl. No.: |
13/222528 |
Filed: |
August 31, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12252390 |
Oct 16, 2008 |
8029120 |
|
|
13222528 |
|
|
|
|
Current U.S.
Class: |
53/456 |
Current CPC
Class: |
Y10T 137/0402 20150401;
B41J 2/19 20130101; B41J 2002/17583 20130101; B41J 2/17566
20130101; B41J 2002/17579 20130101; B41J 2/17559 20130101 |
Class at
Publication: |
53/456 |
International
Class: |
B65B 43/08 20060101
B65B043/08 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 16, 2007 |
JP |
2007-269355 |
Mar 24, 2008 |
JP |
2008-075006 |
Mar 24, 2008 |
JP |
2008-075549 |
Claims
1. A method of manufacturing a liquid container having a tank
chamber, first and second communication holes communicating with
the tank chamber, and a flow channel communicating with the first
communication hole, the method comprising: welding a film to one
surface of the liquid container in which openings communicating
with the tank chamber and the flow channel, respectively, are
formed; filing the tank chamber with a liquid from the second
communication hole disposed in a vertical upper portion of the tank
chamber; and delivering bubbles, which are gathered in the vertical
upper portion of the tank chamber at a time of filling the tank
chamber with the liquid, from the tank chamber to the flow channel
through a bypass channel extending from an opening of the tank
chamber to an opening of the flow channel through a non-welded
portion of the film.
2. The method according to claim 1, further comprising: welding the
non-welded portion of the film to close the bypass channel after
the tank chamber is filled with the liquid and the bubbles are
removed.
3. The method according to claim 1, wherein the first communication
hole is disposed in the vertical upper portion of the tank chamber
and the second communication hole is disposed in a vertical lower
portion of the tank chamber, in a posture of the liquid container
at a time of consuming the liquid, and the tank chamber is filled
with the liquid in a posture of the liquid container which is
vertically reverse of the posture of the liquid container at the
time of consuming the liquid.
4. The method according to claim 1, wherein the liquid container
includes: a main tank chamber, communicating with the liquid
channel; and a liquid sensor, communicating with the second
communication hole and operable to detect the liquid, and the tank
chamber is a bubble trapping chamber for preventing the bubbles
from entering into the liquid sensor at the time of consuming the
liquid.
5. The method according to claim 2, wherein in the delivering of
the bubbles, one or more protrusions protruding from one surface of
the liquid container are used as the non-welded portion, and a gap
formed between the one surface of the liquid container and the film
by the one or more protrusions is used as the bypass channel, and
in the closing the bypass channel, the one or more protrusions are
welded and pressed with the film.
6. The method according to claim 2, wherein in the delivering of
the bubbles, one or more grooves recessed at one surface of the
liquid container are used as the non-welded portion, and a gap
formed between one or more bottom of the one or more grooves and
the one surface of the liquid container is used as the bypass
channel, and in the closing the bypass channel, the one or more
grooves are welded with the film to close the one or more
grooves.
7. The method according to claim 2, further comprising: discharging
the bubbles from the flow channel at the time of filling with the
liquid.
8. A method of manufacturing a liquid container, the liquid
container comprising: a first liquid containing portion,
communicating with air, and adapted to contain a liquid therein; a
second liquid containing portion, disposed downstream of the first
liquid containing portion, and adapted to contain the liquid
therein; a liquid flow channel, communicating the first liquid
containing portion with the second liquid containing portion; a
liquid sensor, disposed downstream of the second liquid containing
portion, and operable to detect the liquid; and a liquid supply
section, disposed downstream of the liquid sensor, and adapted to
discharge the liquid, wherein the second liquid containing portion
is arranged adjacent to the liquid flow channel, a part of the
second containing portion and a part of the liquid flow channel are
formed by fixing a film to a housing, the second liquid containing
portion includes a first communication hole communicating with the
liquid flow channel and a second communication hole communicating
with the liquid sensor, and the first communication hole is
disposed at an upper side of the second liquid containing portion
and the second communication hole is disposed at a lower side of
the second liquid containing portion, in a posture of the liquid
container at a time of consuming the liquid, the method comprising:
a first process of forming the second liquid containing portion,
the liquid flow channel and a bypass channel communicating the
second liquid containing portion with the liquid flow channel, by
fixing the film to the housing while keeping, unfixed, a part of a
border between the second liquid containing portion and the liquid
flow channel in a fixing surface of the housing to which the film
is fixed; a second process of filling the liquid container with the
liquid from the liquid supply section; and a third process of
fixing the film to the part of the fixing surface to close the
bypass channel.
9. The method according to claim 8, wherein a protrusion or a
groove is provided at the border of the fixing surface of the
housing, in the first process, the bypass channel is formed by
fixing the film to the fixing surface while keeping the part of the
fixing surface including the protrusion or the groove unfixed, and
in the third process, the film is fixed to the part of the fixing
surface including the protrusion or the groove to close the bypass
channel.
10. The method according to claim 8, wherein the first
communication hole is disposed proximal to the border between the
second liquid containing portion and the liquid flow channel, and
the bypass channel is disposed at an upper side of the first
communication hole in a posture of the liquid container at a time
of filling with the liquid.
11. The method according to claim 8, wherein the first
communication hole and the second communication hole are arranged
diagonal to each other.
12. The method according to claim 11, wherein a part of the first
liquid containing portion is formed by fixing the film to the
housing.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a Divisional application of U.S. Ser. No. 12/252,390
filed Oct. 16, 2008, which claims priority on Japanese Patent
Applications No. 2007-269355 filed on Oct. 16, 2007, No.
2008-075549 filed Mar. 24, 2008, and No. 2008-0750006 filed Mar.
24, 2008, the disclosures of which are hereby incorporated by
reference in their entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to a liquid container suitable
for detecting an amount of remaining liquid (ink) in a liquid
consuming apparatus such as an inkjet printing apparatus and a
method of manufacturing the liquid container.
[0004] 2. Related Art
[0005] As a representative example of a liquid consuming apparatus,
there is an inkjet printing apparatus having an inkjet print head
for printing an image. Other liquid ejecting apparatuses may
include an apparatus having a coloring material ejecting head used
for manufacturing a color filter and the like of a liquid crystal
display, an apparatus having an electrode material (conductive
paste) ejecting head used for forming electrodes of an organic EL
display, a field emission display (FED), and the like, an apparatus
having a biological organic material ejecting head used for
manufacturing a bio chip, and an apparatus having a sample ejecting
head as a precise pipette.
[0006] In the inkjet printing apparatus as the representative
example of the liquid consuming apparatus, an inkjet print head
having a pressure generator pressurizing a pressure generating
chamber and nozzle orifices ejecting the pressurized ink as ink
droplets is mounted on a carriage. By endlessly supplying the ink
in an ink container to the print head through a flow channel, a
printing operation can be continuously performed. The ink container
is constructed as a detachable cartridge that can be replaced by a
user when the ink is completely consumed.
[0007] There is a method of managing ink consumption by integrating
the number of ink droplets emitted from the print head or the
amount of ink sucked in maintenance by software or a method of
managing when the ink is actually consumed by a predetermined
amount by attaching a liquid level detecting electrode to the ink
cartridge, as a method of managing the ink consumption of an ink
cartridge.
[0008] However, the method of managing the ink consumption by
integrating the number of ejected ink droplets or the amount of ink
by software causes the following problem. The head may eject ink
droplets with non-uniformity in weight. The non-uniformity in
weight of the ink droplets does not affect the image quality but
the ink with a margin is filled in the ink cartridge in
consideration of accumulation of errors in ink consumption due to
the non-uniformity. Accordingly, there is a problem that the ink
corresponding to the margin remains in some apparatuses.
[0009] On the other hand, in the method of managing when the ink is
consumed by the use of an electrode, since the actual amount of
remaining ink can be detected, it is possible to manage the amount
of remaining ink with high reliability. However, since the
detection of the ink level depends on the conductivity of the ink,
the kinds of ink detectable are limited, thereby complicating the
sealing structure of the electrode. Since precious metals with
excellent conductivity and anti-corrosion are usually used as the
material of the electrode, the cost for manufacturing the ink
cartridge is enhanced. Since two electrodes should be necessarily
formed, the number of manufacturing processes increases, thereby
increasing the manufacturing cost.
[0010] Therefore, to solve the above-mentioned problems, a
piezoelectric device (herein, referred to as a sensor unit) is
disclosed in JP-A-2001-146030. The sensor unit monitors the amount
of ink remaining in the ink cartridge by the use of the resonance
frequency of a residual vibration signal resulting from the
residual vibration (free vibration) of a vibrating plate after
forcible vibration when the ink remains and does not remain in a
sensor cavity opposed to the vibrating plate having a piezoelectric
element formed thereon.
[0011] In FIG. 8 of JP-A-2006-248201, plural vertical-direction
changing portions changing the flow of ink in vertical directions
are shown. The space above the vertical-direction changing portions
serves as a bubble trapping space.
[0012] In FIGS. 9 and 14 of JP-A-2006-315302, a structure
supporting a sensor base at three positions of a partition wall and
both main case walls thereof is shown. In JP-A-2001-328277, a
barrier wall is disposed in the liquid opposed to the sensor,
whereby bubbles hardly enter the sensor cavity even when the
bubbles are formed in the liquid level in the tank.
[0013] Techniques of securing a bypass channel of a liquid by not
welding a part of a film covering an opening of a liquid passage
and then closing the bypass channel of the liquid by welding the
part of the film are disclosed in JP-A-2005-022257 and
JP-A-2004-306466.
[0014] The technique disclosed in JP-A-2006-248201 employs a
specific gravity separation method of trapping bubbles having small
specific gravity in the upside by the use of a labyrinth channel on
the basis of a difference in specific gravity between the liquid
and the bubbles.
[0015] Here, as shown in FIG. 8 of JP-A-2006-248201, the ink is
introduced from the lower position of the bubble trapping space and
the ink is discharged from the lower position of the bubble
trapping space. In this case, as described later, when the ink
consumption rate is great due to a continuous printing operation
and thus the ink flow rate is great, the bubbles in the bubble
trapping space are sucked into the ink and discharged along with
the ink in the vicinity of the ink end. Then, bubbles are formed in
the buffer chamber in the just upstream side of the sensor cavity
and the bubbles are detected by the sensor, thereby falsely
detecting the ink end.
[0016] In the technique disclosed in JP-A-2006-315302, the
vibration of the piezoelectric element is absorbed by the main case
coming in contact with the sensor base at three positions, thereby
making it difficult to satisfactorily guarantee the vibration being
detectable by the piezoelectric element. Since the sensor base is
positioned in an opening formed in the main case, bubbles may stay
in minute gaps around the sensor base at the time of injecting the
ink, thereby causing false detection of the ink end. This problem
is not prevented even by the use of the barrier wall shown in
JP-A-2001-328277. This is because the barrier wall hinders the flow
of ink at the time of initially injecting the ink to easily
generate bubbles around the sensor base.
SUMMARY
[0017] An advantage of some aspects of the invention is that it
provides a liquid container that can prevent formation of bubbles
in the immediate upstream of a sensor cavity even when the amount
of remaining ink decreases, thereby enhancing the liquid detection
precision.
[0018] Another advantage of some aspects of the invention is that
it provides a liquid container that can reduce the false detection
by employing a structure for enhancing the amplitude at the time of
detecting the liquid and a structure for suppressing bubbles from
staying around the sensor base at the time of introducing the
liquid.
[0019] Another advantage of some aspects of the invention is that
it provides a method of manufacturing a liquid container that can
deliver bubbles to satisfactorily fill the liquid container with
the liquid even when the bubbles are easily gathered due to its
structure at the time of filling the liquid container with the
liquid.
[0020] According to an aspect of the invention, there is provided a
liquid container including: a case in which a flow channel of a
liquid is exposed from an opening; a sensor base, disposed in the
opening of the case to face the flow channel; a sensor chip,
including: a piezoelectric element, mounted on a surface opposite
to a surface of the sensor base which faces the flow channel; and a
sensor cavity, disposed opposite to the piezoelectric element and
adapted to receive the liquid as a detection target; a film,
adapted to hold the sensor base in the opening and sealing the
opening; a partition wall, partitioning the flow channel in the
case into an upstream buffer chamber and a downstream buffer
chamber; and a bubble trapping section, disposed upstream of the
upstream buffer chamber. The bubble trapping section includes: a
bubble trapping chamber, adapted to trap bubbles upside by allowing
the liquid level to be lowered with reduction in an amount of
remaining liquid at a time of consuming the liquid; an inlet,
communicating at a vertical upper position of the bubble trapping
chamber to introduce the liquid at the time of consuming the
liquid; and an outlet, communicating at a vertical lower position
of the bubble trapping chamber to discharge the liquid at the time
of consuming the liquid.
[0021] According to an aspect of the invention, there is also
provided a method of manufacturing a liquid container having a tank
chamber, first and second communication holes communicating with
the tank chamber, and a flow channel communicating with the first
communication hole, the method including: welding a film to one
surface of the liquid container in which openings communicating
with the tank chamber and the flow channel, respectively, are
formed; filing the tank chamber with a liquid from the second
communication hole disposed in a vertical upper portion of the tank
chamber; and delivering bubbles, which are gathered in the vertical
upper portion of the tank chamber at a time of filling the tank
chamber with the liquid, from the tank chamber to the flow channel
through a bypass channel extending from an opening of the tank
chamber to an opening of the flow channel through a non-welded
portion of the film.
[0022] The present disclosure relates to the subject matter
contained in Japanese patent application Nos. 2007-269355 filed on
Oct. 16, 2007, 2008-75006 filed on Mar. 24, 2008 and 2008-75549
filed on Mar. 24, 2008, which are expressly incorporated herein by
reference in its entirety.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The invention will be described with reference to the
accompanying drawings, wherein like numbers reference like
elements.
[0024] FIG. 1 is a schematic perspective view of an inkjet printer
as a liquid consuming apparatus.
[0025] FIG. 2 is an exploded perspective view of an ink
cartridge.
[0026] FIG. 3 is an exploded perspective view of an ink detector
where a part of FIG. 2 is enlarged.
[0027] FIG. 4 is a sectional view schematically illustrating a flow
channel according to an embodiment of the invention including a
bubble trapping chamber on the upstream side in the ink
detector.
[0028] FIG. 5 is a sectional view illustrating a bubble trapping
chamber of a comparative example of FIG. 4.
[0029] FIG. 6 is a front view of the ink cartridge.
[0030] FIG. 7 is a sectional view taken along line A1-A1 of FIG.
6.
[0031] FIG. 8 is a sectional view taken along line B1-B1 of FIG.
6.
[0032] FIG. 9 is a right side view of the ink cartridge.
[0033] FIG. 10 is a perspective view of a sensor base as viewed
from the rear side.
[0034] FIG. 11 is a perspective view illustrating a sensor base
mounted with a sensor chip as viewed from the outside.
[0035] FIG. 12 is a sectional view of an assembled ink
detector.
[0036] FIG. 13 is a diagram schematically illustrating a positional
relation between first and second holes of the sensor base and a
partition wall.
[0037] FIGS. 14A and 14B are diagrams illustrating modified
examples of the partition wall.
[0038] FIGS. 15A and 15B are diagrams illustrating modified
examples in which an assistant support portion is provided.
[0039] FIG. 16 is a diagram illustrating a modified example where
the partition wall and the assistant support portion are provided
in the sensor base.
[0040] FIG. 17 is a sectional view of the sensor chip.
[0041] FIG. 18 is a plan view schematically illustrating an
attachment structure of the sensor base shown in FIGS. 14B, 15B,
and 16 as viewed from the upside of the drawings.
[0042] FIG. 19A is a plan view illustrating the state equivalent to
that of FIG. 18, FIG. 19B is a sectional view taken along line
A2-A2 of FIG. 19A, and FIG. 19C is a sectional view line B2-B2 of
FIG. 19A.
[0043] FIG. 20 is a plan view illustrating a specific example of
FIGS. 19A to 19C.
[0044] FIG. 21 is a sectional view taken along line A3-A3 of FIG.
20.
[0045] FIG. 22 is a sectional view taken along line B3-B3 of FIG.
20.
[0046] FIG. 23 is a plan view illustrating a main case before the
sensor base is mounted thereon.
[0047] FIG. 24A is a plan view illustrating the state equivalent to
those of FIGS. 19A and 20 and FIG. 24B is a sectional view taken
along line A4-A4 of FIG. 24A.
[0048] FIG. 25 is a view of the case body shown in FIG. 2 as viewed
from the film side.
[0049] FIG. 26 is an enlarged plan view of part C in FIG. 25.
[0050] FIG. 27 is an enlarged perspective view of part C in FIG.
25.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0051] Hereinafter, exemplary embodiments of the invention will be
described in detail. The following embodiments do not excessively
limit the scope of the invention described in the appended claims
and all elements described in the embodiments are not essential to
the solving means of the invention.
[0052] Ink Cartridge
[0053] An ink cartridge (liquid container) to which a liquid
detecting device according to an embodiment of the invention is
attached will be described now with reference to the accompanying
drawings.
[0054] FIG. 1 is a diagram schematically illustrating a
configuration of an inkjet printing apparatus (liquid consuming
apparatus) employing the ink cartridge according to this
embodiment. A carriage 1 is guided by a guide member 4 via a timing
belt 3 driven by a carriage motor 2 and reciprocates in the axial
direction of a platen 5.
[0055] An inkjet print head 12 is mounted on a side of the carriage
1 facing a printing sheet 6. An ink cartridge 100 supplying ink
(water ink or oil ink) to the print head 12 is demountably mounted
on a holder (not shown) disposed in the upper portion of the
carriage 1.
[0056] A cap member 13 is disposed at a home position (in the right
side in FIG. 1) which is a non-printing area of the printing
apparatus. The cap member 13 is pressed on a nozzle formation
surface of the print head 12 to form a closed space with the nozzle
formation surface, when the print head 12 mounted on the carriage 1
moves to the home position. A pump unit 10 giving a negative
pressure to the closed space formed by the cap member 13 to perform
a cleaning process is disposed below the cap member 13.
[0057] In the vicinity of a printing area in the cap member 13, a
wiping unit 11 having an elastic plate of rubber is disposed to
reciprocate in the horizontal direction about the moving trace of
the print head 12. The wiping unit 11 wipes out the nozzle
formation surface of the print head 12 as needed when the carriage
1 reciprocates with respect to the cap member 13.
[0058] FIG. 2 is a perspective view schematically illustrating a
configuration of an ink cartridge 100. In FIG. 1, the ink cartridge
100 is disposed to correspond to the vertical direction in the
state where the ink cartridge is mounted on the carriage 1.
Accordingly, the term "vertical" used in the following description
means the vertical direction in the state where the ink cartridge
100 is mounted on the carriage 1.
[0059] The ink cartridge 100 includes a film 104 covering the rear
surface of the main case 102, a cover member 106 covering the film
104 and the bottom surface of the main case 102, and a film 108
covering the surface and the top surface of the main case 102.
[0060] The main case 102 is partitioned by ribs or walls complexly.
The main case 102 includes an ink channel section having an ink
containing area and an ink delivery channel, an ink-side passage
allowing the ink containing area to communicate with the
atmospheric air, and an atmospheric communication portion having an
atmospheric air valve receiving chamber and an atmospheric air-side
passage, detailed description of which are omitted (for example,
see JP-A-2007-15408).
[0061] The ink delivery channel of the ink channel section finally
communicates with an ink supply section 110 and the ink in the ink
cartridge 100 is sucked up from the ink supply section 110 for
supply by the negative pressure.
[0062] An ink supply needle (not shown) of the holder disposed in
the carriage 1 is inserted into the ink supply section 110. The ink
supply section 110 includes a supply valve 112 that is pressed by
the ink supply needle and slides to open its valve, a sealing
member 114 formed of an elastic material such as elastomer, which
is fitted to the surrounding of the ink supply needle, and an
urging member 116 formed of a coil spring to urge the sealing
member 114 to the supply valve 112. Theses elements are assembled
by fitting the urging member 116, inserting the sealing member 114
to the ink supply section 110, and finally pushing the supply valve
112.
[0063] A lever 120 engaging with the holder disposed in the
carriage 1 is disposed on one side surface of the main case 102. An
opening 130 opened at a position corresponding to the upstream of
the ink supply section 110 and the end of the ink delivery channel
is formed at a position on one side surface of the main case 102,
for example, at a position below the lever 120. A welding rib 132
is formed in the circumferential edge of the opening 130. A
partition rib 136 partitions the ink delivery channel 134 facing
the opening 130 into an upstream buffer chamber 134a and a
downstream buffer chamber 134b (the reference numerals are omitted
in FIG. 2; see FIGS. 8 and 9) is formed.
[0064] Ink Detector
[0065] An ink detector 200 employing the liquid detector according
to this embodiment, which is formed by the main case 102, the ink
delivery channel 134, and the partition rib 136, will be described
now with reference to FIGS. 2 and 3. FIG. 3 is an enlarged view of
the ink detector 200 in the ink cartridge 100 shown in FIG. 2.
[0066] In FIGS. 2 and 3, the ink detector 200 includes a resin main
case 102 in which the ink delivery channel 134 is formed, a metal
sensor base 210 disposed in the opening 130 of the main case 102 to
face the ink delivery channel 134, a sensor chip 220 mounted on a
surface of the sensor base 210 opposite to the surface facing the
ink delivery channel 134, a film 202 holding the sensor base 210 in
the opening 130 and sealing the opening 130, and a partition wall
136 partitioning the ink delivery channel 134 in the main case 102
into upstream and downstream. The film 202 is bonded to the top
surface of the sensor base 210 and is welded to the welding rib 132
around the opening 130.
[0067] In FIGS. 2 and 3, the ink detector 200 further includes a
pressing cover 230 disposed above the sensor base 210, the sensor
chi p220, and the film 202, a relay terminal 240 having terminals
242 electrically connected to the sensor chip 220 through a hole
202a formed in the film 202, and a circuit board 250 received in
the pressing cover 230 and electrically connected to the terminals
244 of the relay terminal 240. In the liquid container 100
according to this embodiment, the pressing cover 230, the relay
terminal 240, and the circuit board 250 are not essential
elements.
[0068] Upstream Channel Structure of Ink Detector
[0069] Before describing in detail the ink detector, the channel
structure upstream of the ink delivery channel 134 in the ink
detector will be described with reference to FIG. 4.
[0070] FIG. 4 is a sectional view illustrating the most downstream
portion including the ink detector 200 in the ink container
according to this embodiment. In FIG. 4, a tank chamber (liquid
containing chamber) 260 which is an ink containing area and a
detour channel 270 having a labyrinth shape bent vertically and
horizontally as a delivery channel communicating with the tank
chamber are shown schematically. For example, a bubble trapping
section 280 is disposed at the most downstream end of the detour
channel 270. The bubble trapping section 280 communicates with the
ink delivery channel 134 of the ink detector 200 through, for
example, a communication channel 290.
[0071] The bubble trapping section 280 includes a bubble trapping
chamber (tank chamber) 282 trapping the bubbles in the upper
portion thereof with the lowering of the liquid level LH1 due to
the decrease in the amount of remaining ink at the time of
consuming the ink, an inlet 284 introducing the ink at a vertical
upper position of the bubble trapping chamber 282 at the time of
consuming the ink, and an outlet 286 discharging the ink at a
vertical lower position of the bubble trapping chamber 282 at the
time of consuming the ink.
[0072] In this embodiment, the bubble trapping chamber 282 employs
the specific gravity separation method of separating the ink and
the bubbles by the use of a difference in specific gravity between
the ink and the bubbles. The specific gravity separation method is
known in a system for continuously supplying a liquid. This
embodiment employs a structure for not mixing the bubbles into the
ink, particularly, even when the amount of remaining ink
decreases.
[0073] The bubble trapping chamber 282 traps the bubbles in the
upper portion thereof with the lowering of the liquid level LH1 due
to the decrease in the amount of remaining liquid. The bubble
trapping employs the specific gravity separation method without any
change and is not different from that of the bubble trapping
chamber used to endlessly supply the liquid.
[0074] In the course of trapping the bubbles when the amount of
remaining ink decreases, the inlet 284 is located in the vertical
upper portion of the bubble trapping chamber 282. Then, the bubbles
initially generated from the inlet 284, but when the lower end of
the bubble group does not reach the outlet 284, no meniscus is
formed in the inlet 284, thereby stopping the generation of the
bubbles. At the same time, the bubbles gathered in the upper
portion are broken and merged to form a gas space, the liquid level
of which is LH1. Then, in the bubble trapping chamber 282, the
mixture of the bubbles into the liquid is prevented. When the
outlet 286 of the bubble trapping chamber 282 is located at the
vertical lower position, only the liquid not containing the bubbles
is discharged and thus the bubbles are not mixed in the
communication channel 290 and the delivery channel 134 of the ink
detector 200 downstream therefrom. Accordingly, the false detection
is prevented at the time of detecting the ink end by detecting the
bubbles.
[0075] FIG. 5 shows a comparative example of a related art. In the
comparative example, the bubble trapping chamber 500 used to
endlessly supply the liquid is made to communicate with the
delivery channel 134 of the ink detector 200 through the
communication channel 510. That is, the inlet 502 and the outlet
504 of the bubble trapping chamber 500 are both located at the
vertical lower position in the bubble trapping chamber 500. In the
bubble trapping chamber 500, the bubbles having small specific
gravity can be trapped in the vertical upper space.
[0076] However, in the comparative example, particularly, when the
amount of ink consumption per unit time is great, the ink in the
bubble trapping chamber 500 is replaced with the bubbles and thus a
lot of bubbles may remain in the upstream portion therefrom when
the bubbles reach the ink detector 200. When time elapses in this
state, the bubbles are finally broken and disappear, but the ink
forming the bubbles may serve as the remaining ink and may enter
the ink detector 200 at the time of consuming the ink, where the
remaining ink may be detected later. In addition, the bubbles 506
in the bubble trapping chamber 500 are involved in the flow of ink
and the bubbles are delivered to the delivery channel 134 of the
ink detector 200 through the communication channel 510 downstream
therefrom. Then, as described later, the bubbles enter the sensor
cavity, thereby causing the false detection of the ink end.
[0077] Accordingly, in this embodiment shown in FIG. 4, the ink is
introduced from the inlet 284 disposed at the upper position of the
bubble trapping chamber 282 and the remaining of the bubbles in the
ink can be satisfactorily prevented in the bubble trapping chamber
282 during the lowering of the liquid level LH1 due tow the
decrease in the amount of remaining ink.
[0078] In this embodiment, the bubble trapping chamber 282 may be
connected directly to the delivery channel 134, but the
communication channel 290 may be disposed downstream of the bubble
trapping chamber 282. The communication channel 290 includes a
supply hole 292 communicating with the outlet 286 of the bubble
trapping chamber 282 at the time of consuming the ink and guides
the ink introduced from the vertical lower position to the vertical
upper portion. Then, the communication channel 290 introducing the
ink from the outlet 294 located at the vertical upper position of
the delivery channel 134 (upstream buffer chamber 134a) is further
provided.
[0079] Accordingly, in the vicinity of the ink end after the ink in
the bubble trapping chamber 282 is consumed, as shown in FIG. 4,
the liquid level HL2 in the delivery channel 134 (upstream buffer
chamber 134a) is lowered and a meniscus is formed at that time.
Therefore, in the delivery channel 134 (upstream buffer chamber
134a), the bubbles are removed from the liquid in the course of
repeating the destruction and reconstruction of the meniscus.
Accordingly, the false detection can be further prevented.
[0080] In this embodiment, a liquid containing chamber (tank
chamber) 260 disposed upstream of the bubble trapping chamber 282
to contain the ink is opened to the atmospheric air as described
above. Then, the space above the meniscus formed in the bubble
trapping chamber 282 can be filled with the atmospheric air instead
of the consumed ink.
[0081] In this embodiment, a detour channel 270 bent in a labyrinth
shape is disposed between the bubble trapping chamber 282 and the
liquid containing chamber (tank chamber) 260. The detour channel
270 can also trap the bubbles.
[0082] In this embodiment, the ink cartridge may be disposed at the
time of filling the ink container so that the bubble trapping
chamber 282 has a posture vertically reverse to that at the time of
consuming the ink. That is, at the time of filling the ink
container, the bubble trapping chamber is vertically reverse and
the ink is introduced from the outlet 286 located at the vertical
upper position. Therefore, the bypass channel 288 opened at the
time of filling the ink container to allow the bubble trapping
chamber 282 to communicate with the detour channel 270 can be
disposed vertically above the bubble trapping chamber 282 at the
time of filling the ink container. The bypass channel 288 can
deliver the bubbles gathered in the upper portion of the bubble
trapping chamber 282 to the detour channel 270 at the time of
filling the ink container. Accordingly, it is possible to prevent
the bubbles from being mixed into the liquid in the bubble trapping
chamber 282. Since the gathering of the bubbles in the bubble
trapping chamber 282 can be prevented, the bubble trapping chamber
282 can be filled with the ink. Accordingly, it is possible to
prevent the false detection of the ink end due to the mixture of
the bubbles even when a lot of ink remains in the bubble trapping
chamber 282 of the ink detector 200. The bypass channel 288 is
closed at the time of consuming the ink.
[0083] Details of Ink Detector
[0084] Details of the ink detector 200 will be described now with
reference to FIGS. 6 to 13. FIG. 6 is a front view of the main case
102. As shown in FIG. 7 which is a sectional view taken along line
A1-A1 of FIG. 6, the ink delivery channel 134 is exposed from the
opening 130 at the position close to the end before reaching the
ink supply section 110 shown in FIG. 1.
[0085] As shown in FIG. 8 which is a sectional view taken along
line B1-B1 of FIG. 6 and FIG. 9 which is a right side view of the
ink cartridge 100, the ink delivery channel 134 exposed from the
opening 130 is partitioned into the upstream buffer chamber 134a
and the downstream buffer chamber 134b by the partition wall 136.
The inlet 135a is disposed to face the upstream buffer chamber 134a
as shown in FIG. 8 and the outlet 135b is disposed to face the
downstream buffer chamber 134b as shown in FIG. 6.
[0086] FIG. 10 is a perspective view of the sensor base 210 as
viewed from the downside. As shown in FIG. 10, a first hole (supply
path) 212 and a second hole (discharge path) 214 penetrating the
sensor base 210 in the thickness direction are disposed.
[0087] FIG. 11 is a perspective view of the sensor base 210 mounted
with the sensor chip 220 as viewed from the upside.
[0088] FIG. 12 is a sectional view schematically illustrating a
state where the ink detector 200 shown in FIGS. 2 and 3 is
assembled. FIG. 17 is a sectional view of the sensor chip.
[0089] In FIGS. 12 and 17, the sensor chip 220 has a sensor cavity
222 receiving the ink (liquid) as a detection target and the lower
surface of the sensor cavity 222 is opened to receive the ink. The
upper surface of the sensor cavity 222 is closed by a vibrating
plate 224 as shown in FIGS. 11 and 17. A piezoelectric element 226
is disposed on the upper surface of the vibrating plate 224.
[0090] Specifically, as shown in FIG. 17, the sensor chip 220
includes a vibration cavity forming base 300 that is constructed by
stacking the vibrating plate 224 on a cavity plate 301 and that has
a first surface 300a and a second surface 300b opposed to each
other. The sensor chip 220 further includes the piezoelectric
element 226 stacked on the second surface 300b of the vibration
cavity forming base 300.
[0091] In the vibration cavity forming base 300, the cavity 222
having a cylindrical space shape for receiving the medium (ink) as
the detection target is opened in the first surface 300a and the
bottom surface 222a of the cavity 222 can be made to vibrate by the
vibrating plate 224. In other words, the portion actually vibrating
in the vibrating plate 224 is defined in outline by the cavity 222.
Electrode terminals 228 and 228 are formed on both sides of the
second surface 300b of the vibration cavity forming base 300.
[0092] A lower electrode 310 is formed on the second surface 300b
of the vibration cavity forming base 300 and the lower electrode
310 is connected to one electrode terminal 228.
[0093] A piezoelectric layer 312 is stacked on the lower electrode
310 and an upper electrode 314 is stacked on the piezoelectric
layer 312. The upper electrode 314 is connected to an assistant
electrode 320 insulated from the lower electrode 310. The assistant
electrode 320 is connected to the other electrode terminal 228.
[0094] The piezoelectric element 226 performs the function of
determining the ink end on the basis of the difference in
electrical characteristics (such as frequency) due to the existence
of the ink in the sensor cavity 222. The piezoelectric layer may be
formed of piezoelectric zirconate titanate (PZT), piezoelectric
lead zirconate titanate (PLZT), or a lead-free piezoelectric film
not containing lead.
[0095] The sensor chip 220 is fixed monolithically to the sensor
base 210 by an adhesive layer 216 by placing the bottom of the chip
body on the top center portion of the sensor base 210, and the
space between the sensor base 210 and the sensor chip 220 are
sealed by the adhesive layer 216.
[0096] Detection of Amount of Remaining Ink
[0097] As shown in FIG. 12, the ink introduced from the supply hole
135a of the ink delivery channel 134 stays in the upstream buffer
chamber 134a which is one chamber partitioned by the partition wall
136.
[0098] The upstream buffer chamber 134a communicates with the
sensor cavity 222 of the sensor chip 220 through the first hole 212
of the sensor base 210. Accordingly, the ink in the upstream buffer
chamber 134a is guided to the sensor cavity 222 through the first
hole 212 with the supply of the ink. Here, the vibration of the
vibrating plate 224 made to vibrate by the piezoelectric element
226 is transmitted to the ink and the existence of the ink is
detected on the basis of the frequency of the residual vibration
waveform. In the endpoint where air enters the sensor cavity 222 in
addition to the ink, the attenuation of the residual vibration
waveform is great and the residual vibration waveform becomes a
frequency higher than that of the case where the ink is filled
full. By detecting the state, the ink end can be detected.
[0099] Specifically, when a voltage is applied to the piezoelectric
element 226, the vibrating plate 224 is deformed with the
deformation of the piezoelectric element 226. When the application
of the voltage is stopped after the piezoelectric element 226 is
forcibly deformed, the bending vibration remains in the vibrating
plate 224 for a moment. The residual vibration is free vibration of
the vibrating plate 224 and the medium in the sensor cavity 222.
Accordingly, by setting the voltage applied to the piezoelectric
element 226 to a pulse waveform or a rectangular waveform, the
resonance state of the vibrating plate 224 and the medium after the
application of the voltage can be easily obtained.
[0100] The residual vibration is the vibration of the vibrating
plate 224 and accompanies the deformation of the piezoelectric
element 226. Accordingly, the piezoelectric element 226 generates a
back electromotive force with the residual vibration.
[0101] As shown in FIG. 12, the circuit board 250 includes an
electrode 254 connected to a through-hole 252 penetrating the front
and rear surfaces thereof. A signal from the relay terminal 240
contacting the sensor chip 220 is supplied through the through-hole
252 and the electrode 254 and is processed by an analysis circuit
(not shown) mounted on the printer body, and the result is
transmitted to a semiconductor memory (not shown) mounted on the
circuit board 250. That is, the back electromotive force of the
piezoelectric element 226 is transmitted to the analysis circuit
through the relay terminal 240 and the result is stored in the
semiconductor memory.
[0102] Since the resonance frequency can be specified by the use of
the back electromotive force detected as described above, the
existence of the ink in the ink cartridge 100 can be detected on
the basis of the resonance frequency. The semiconductor memory
stores identification information such as the kind of the ink
cartridge 100, information on the color of the ink contained in the
ink cartridge 100, and information on the amount of remaining
ink.
[0103] The ink staying in the sensor cavity 222 is guided to the
downstream buffer chamber 134b through the second hole 214 of the
sensor base 210 with the additional supply of the ink. The ink is
supplied along the ink delivery channel 134 through the ink outlet
135b, and is finally discharged from the ink cartridge 100 through
the ink supply section 110 (see FIG. 2).
[0104] Method and Structure for Supporting Sensor Base
[0105] When it is intended to fit the sensor base 210, the sensor
chip 220, and the film 202 to the opening 130, the following two
processes are required. That is, a first process of disposing the
metal sensor base 210 mounted with the sensor chip 220 in the
opening 130 of the main case 102 having the flow channel 134 formed
therein to face the flow channel 134 and a second process of
welding the film 202 to the rib 132 around the opening 130 to allow
the sensor base 210 to be supported by the main case 102 with the
film 202 interposed therebetween are necessary. With the first
process and the second process, the sensor cavity 222 formed in the
sensor chip 220 communicates with the upstream buffer chamber 134a
through the first hole 212 formed in the sensor base 210 and
communicates with the downstream buffer chamber 134b through the
second hole 214 formed in the sensor base 210, thereby forming the
detection path of the liquid as described above.
[0106] In this embodiment, in the first process before welding the
film 202, the sensor base 210 is supported by only the partition
wall 136 (supporting function using the partition wall). Before the
film 202 is welded to the welding rib 132 around the opening 130,
the sensor base 210 should be temporarily positioned at a
predetermined position of the opening 130. After the sensor base
210 is supported by the film 202 in the second process, the sensor
base 210 can come in contact with only the partition wall 136 in
the depth direction of the opening 130 (upstream and downstream
partitioning function using the partition wall). Since the sensor
base 210 is supported by the film 202, the sensor base 210 does not
always be in contact with the partition wall 136 but the upstream
and downstream partitioning function of the partition wall 136 is
always necessary.
[0107] Here, as shown in FIG. 12, in this embodiment, a channel
wall 102a disposed opposite the sensor base 210 is provided to
define the ink delivery channel 134. The partition wall 136 is
formed monolithically with the channel wall 102a. The partition
wall 136 is an essential structure for partitioning the ink
delivery channel 134 into the upstream buffer chamber 134a and the
downstream buffer chamber 134b. This is because it is not
guaranteed that the ink or the bubbles as the medium in the ink
delivery channel 134 pass through the sensor cavity 222 when the
partition wall 136 is not disposed. When the ink or the bubbles in
the ink delivery channel 134 do not pass through the sensor cavity
222, the sensor chip 220 false detects the end point of the
ink.
[0108] In order to partition the ink delivery channel 134 into the
upstream buffer chamber 134a and the downstream buffer chamber
134b, the partition wall 136 should come in contact with the sensor
base 210 or the gap between the sensor base 210 and the partition
wall 136 is small so as not to allow the bubbles to pass through
the gap. In other words, the flow resistance of the gap should be
greater than the flow resistance of the first hole 212, thereby not
permitting the passage of the bubbles. This is the inherent
function of the partition wall 136.
[0109] On the other hand, the partition wall 136 is contacted and
supported by the sensor base 210 at the time of fitting the sensor
base 210 (first process), thereby preventing the sensor base 210
from falling into the opening 130. That is, in the first process,
the partition wall 136 has the function of temporarily supporting
the sensor base 210.
[0110] After the film 202 is welded to the welding rib 132 around
the opening 130 and the sensor base 210 and the sensor chip 220 are
attached to the opening 130, the sensor base 210 comes in contact
with only the partition wall 136, except for the sensor chip 220
and the film 202. That is, the sensor base 210 can come in contact
with only the partition wall 136 in the depth direction of the
opening 130.
[0111] Accordingly, it is possible to detect the residual vibration
waveform by the use of the piezoelectric element 226. In this
embodiment, the main case 102 of the ink detector 200 is a part of
the main case of the ink cartridge 100 and has a great capacity. In
general, the main case 102 is formed of a flexible resin material
such as polypropylene and thus the absorption of vibration thereof
increases with the increase in capacity.
[0112] Here, when the piezoelectric element 226 vibrates, the
sensor base 210 mounted with the sensor chip 220 also vibrates in
addition to the vibrating plate 224. When the contact area between
the sensor base 210 and the main case 102 is great, the vibration
of the sensor base 102 is absorbed by the main case 102. In this
case, the amplitude of the residual vibration waveform is not
enough to detect the residual vibration waveform by the use of the
piezoelectric element 226.
[0113] In this embodiment, since the sensor base 210 is supported
by only the film 202 and the partition wall 136, the vibration wave
absorbed by the main case 102 is minimized and thus the amplitude
enough to detect the residual vibration by the use of the
piezoelectric element 226 is guaranteed.
[0114] FIG. 13 is a sectional view of the partition wall 136 as
viewed from the downside. The partition wall 136 is located between
the first and second holes 212 and 214 of the sensor base 210. The
thickness of the end of the partition wall 136 is the maximum when
the partition wall 136 comes in contact with the first and second
holes 212 and 214 and should not be set to clog the first and
second holes 212 and 214. The clogging enhances the flow resistance
of the first and second holes designed with predetermined flow
resistance.
Modified Example
[0115] Although this embodiment has been described in detail, it
should be understood by those skilled in the art that the
embodiment can be modified in various forms without departing from
the idea and advantages of the invention. Therefore, the following
modified examples should be included in the scope of the invention.
For example, in the specification or drawings, a term described at
least once along with another term having broader meaning or
equivalent meaning can be replaced with the another term in any
place of the specification or drawings.
[0116] As shown in FIGS. 14A and 14B, the partition wall 136 may
have a shape in which the thickness of the free end 136b is smaller
than that of the base portion 136a close to the channel wall 102a.
That is, even when the base portion 136a is broader than the
inter-edge distance of the first and second holes 212 and 214, it
does not cause any problem so long as the thickness of the free end
136b is equal to or less than the inter-edge distance as shown in
FIG. 12. This is because it does not enhance the flow resistance of
the first and second holes 212 and 214. By broadening the base
portion 136a, the shaping property for the insertion molding can be
improved. As the method of thinning the free end 136b, the free end
may not be tapered with a slope as shown in FIG. 14B, but may be
curved.
[0117] In order to enhance the stability of the attachment of the
sensor base 210, the configuration shown in FIGS. 15A and 15B may
be employed. That is, an assistant support rib 138 may be provided
in addition to the partition wall 136. In FIGS. 15A and 15B, two
assistant support ribs 138 contactable with both ends in the
longitudinal direction of the sensor base 210 are disposed.
However, the height H1 from the channel wall 102a to the end of two
assistant support ribs 138 is smaller than the height H2 to the end
of the partition wall 136.
[0118] In the embodiment shown in FIG. 12, since the sensor base
210 is supported by only the partition wall 136 at the time of
attachment, the center of the sensor base 210 is supported like a
seesaw, which provides bad stability. In the embodiment shown in
FIGS. 15A and 15B, even when the sensor base 210 is inclined, the
lowered end thereof comes in contact with the assistant support rib
138 and is supported at two points including the partition wall
136, which provides good stability.
[0119] However, regarding the assistant support rib 138, since the
sensor base 210 is substantially parallel to the channel wall 102a
after the sensor base 210 is assembled as shown in FIG. 15B, the
sensor base 210 does not come in contact with the assistant
supporting rib 138. Accordingly, similarly to the embodiment shown
in FIG. 12, the amplitude of the residual vibration waveform can be
guaranteed greatly.
[0120] After the sensor base 210 is assembled, the assistant
support rib 138 can prevent the sensor base 210 from being
excessively inclined even in the abnormal state where falling
impact force acts. Accordingly, it is possible to prevent the
sensor base 210 supported by the film 202 from being excessively
inclined to tear down the film 202.
[0121] The position of the partition wall 136 is not limited to the
channel wall 102a. For example, as shown in FIG. 16, a partition
wall 216 vertically extending downward from between the first and
second holes 212 and 214 of the sensor base 210 may be provided.
The partition wall 216 comes in contact with the channel wall 102a
or is opposed to the channel wall with a slight gap having the flow
resistance greater than the flow resistance of the first hole 212.
In FIG. 16, an assistant support rib 218 vertically extending
downward from both ends in the longitudinal direction of the sensor
base 210 is provided. The height H1 from the bottom surface of the
sensor base 210 to the end of two assistant support ribs 218 is
smaller than the height H2 to the end of the partition wall 216. In
this case, the same advantages as the embodiment shown in FIGS. 15A
and 15B can be obtained. A partition wall may be disposed in one of
the channel wall 102a and the sensor base 210 and an assistant
support rib may be disposed in the other. In this way, when the
partition wall 216 and/or the assistant support ribs 218 are
disposed in the sensor base 210, the sensor base 210 is subjected
to, for example, a cutting process.
[0122] Structure for Preventing False Detection
[0123] A structure for preventing the false detection due to the
bubbles will be described now with reference to FIGS. 18 to 23.
[0124] FIG. 18 is a plan view schematically illustrating an
attachment structure of the sensor base 210 shown in FIGS. 14B,
15B, and 16 as viewed from the upside of the drawings. However, the
film 202 is omitted from FIG. 18. As shown in FIG. 18, in a state
where an opening 102A is formed in the main case 102 and the sensor
base 210 is disposed in the opening 102A, the sensor base 210 is
supported by the film 202. However, in FIG. 18, the film 202 is not
shown.
[0125] Here, a slight gap D1 is formed between the inner wall of
the opening 102A and four sides of the sensor base 210. By setting
a margin in design to reduce the gap D1, the sensor base 210 is
positioned in the opening 102A.
[0126] A problem of the structure shown in FIG. 18 will be
described. At the time of filling the main case 102 with the ink,
the ink is filled in the main case 102 in a state where the main
case is almost in vacuum. At this time, the gap D1 communicates
with the upstream buffer chamber 134a or the downstream buffer
chamber 134b shown in FIG. 12 but is narrow enough not to pass the
ink. Accordingly, when the ink is fully filled in the upstream
buffer chamber 134a or the downstream buffer chamber 134b, bubbles
remain in the gap D1.
[0127] Since the film 202 is formed of, for example, polypropylene
(PP) and thus has the gas transmitting property, the bubbles grow
in a great size by attracting the gas for a long time. The grown
bubbles depart from the gap D1 due to the vibration of the
piezoelectric element 226 (see FIG. 1) on the sensor base 210 and
enter the upstream buffer chamber 134a or the downstream buffer
chamber 134b communicating with the sensor cavity 222 shown in FIG.
12. When the bubbles reach the sensor cavity 222, the ink end is
falsely detected in spite of the remaining ink.
[0128] A structure for improving this problem is schematically
shown in FIGS. 19A to 19C. FIG. 19A is a plan view of the same
state as shown in FIG. 18. FIG. 19B is a sectional view taken along
line A2-A2 of FIG. 19A and FIG. 19C is a sectional view taken along
line B2-B2 of FIG. 19A.
[0129] FIG. 19A shows a principle for solving the problem and it is
thus that the sensor base 210 schematically shown is a rectangular
shape having four sides. Four positioning portions 410, 411, 412,
and 413 protruding to four sides of the sensor base 210 are locally
disposed at positions of the opening 402 opposed to four sides of
the sensor base 210.
[0130] At this time, as shown in FIG. 19A, the gap D1 is formed
between the length in the lateral direction of the sensor base 210
and the distance between the positioning portions 410 and 412.
Similarly, the gap D1 is formed between the length in the
longitudinal direction of the sensor base 210 and the distance
between the positioning portions 411 and 413. By defining the gap
D1 as a size margin in design, the sensor base 210 can be
positioned by the use of four positioning portions 410 to 413. The
size of the gap D1 is equal to the size of the gap D1 shown in FIG.
18 and the gap D1 is too narrow to pass the ink.
[0131] On the other hand, in the area other than four positioning
portions 410, 411, 412, and 413, a gap D2 sufficiently greater than
the gap D1 based on the design margin is formed between the wall
portion of the opening 402 and four sides of the sensor base 210.
The gap D2 forms a part of the flow channel 134 formed by the
upstream buffer chamber 134a or the downstream buffer chamber 134b
shown in FIGS. 19B and 19C and partitioned by the partition wall
136 shown in FIG. 19A.
[0132] That is, at the time of injecting the ink, the ink is
introduced into the sensor cavity 222 through the first hole 212 of
the sensor base 210 as indicated by the solid line in FIG. 19B, but
the ink introduced from the inlet 135a to the upstream buffer
chamber 134a is diffused by the wall (sensor base 210) located in
the traveling direction and also flows in the gap D2 around the
sensor base 210 as indicated by the broken line in FIG. 19B.
Alternatively, the ink is discharged from the sensor cavity 222 to
the outlet 135b through the second hole 214 of the sensor base 210
as indicated by the solid line in FIG. 19C, but the ink discharged
from the second hole 214 is diffused by the wall (wall of the
downstream buffer chamber 134b) located in the traveling direction
and also flows in the gap D2 around the sensor base 210 as
indicated by the broken line in FIG. 19B.
[0133] In this way, the gap D2 is filled with the ink and thus the
bubbles do not remain. Accordingly, it is possible to prevent the
false detection of the ink end.
[0134] When it is intended for the ink to easily flow in the gap
D2, it is preferable that the inlet 135a of the upstream buffer
chamber 134a is located at a position not opposed to the first hole
212 of the sensor base 210 and the outlet 135b of the downstream
buffer chamber 134b is located at a position not opposed to the
second hole 214 of the sensor base 210. Accordingly, as described
above, since the wall exists in the traveling direction of the ink
introduced or discharged, the ink is diffused and easily flows in
the gap D2.
[0135] Here, two positioning portions 410 and 412 of four
positioning portions exist in an extension line of the partition
wall 136 (see FIG. 19A). Otherwise, the flow channel connecting one
side of the partition wall 136 to the other side is formed by the
gap D2 and thus the ink channel not passing through the sensor
cavity 222 is formed.
[0136] Amore specific example of the example shown in FIGS. 19A to
19C is shown in FIGS. 20 to 23. FIG. 20 is a plan view illustrating
a specific example of FIGS. 19A to 19C. FIG. 21 is a sectional view
taken along line A3-A3 of FIG. 20. FIG. 22 is a sectional view
taken along line B3-B3 of FIG. 20. FIG. 23 is a plan view of the
main case 400 before the sensor base 210 is fitted thereto.
[0137] As shown in FIG. 20, a ring-shaped welding rib 404 thermally
welded to the film 202 (not shown) is formed around the opening 402
of the main case 400. The sensor base 210 has four sides in total,
in which two sides are opposed to each other in two axes
perpendicular to each other. The sensor base 210 has four sides to
be positioned and the shape for connecting the sides is not
limited.
[0138] As shown in FIGS. 20 to 23, four positioning portions 410,
411, 412, and 413 protruding to four sides of the sensor base 210
are disposed at positions opposed to four sides of the sensor base
210 in the opening 402. The positioning portion 410 has a
longitudinal shape along one side, that is, the longitudinal side,
of the sensor base 210. The other positioning portions 411 to 413
are locally disposed with respect to the other three sides of the
sensor base 210.
[0139] By setting the design margin on the gap D1 (omitted in FIGS.
20 and 21) between four sides in total of the sensor base 210, in
which two sides are opposed to each other in two axes perpendicular
to each other, and four positioning members 410 to 413 opposed to
four sides, the sensor base 210 is positioned in the opening 402.
By forming at least one positioning portion 410 of four positioning
portions in a longitudinal shape along one side, particularly, the
longitudinal side, of the sensor base 210, the sensor base 210 can
be effectively positioned in the rotation direction thereof.
However, it is not preferable in view of the generation of bubbles
that a lot of gaps D1 are set, but it is preferable in view of the
regulation of rotation that the longitudinal positioning portion is
formed along only one side.
[0140] In the area other than four positioning portions 410, 411,
412, and 413, the gap D2 sufficiently greater than the gap based on
the design margin is formed between the wall portion of the opening
402 and four sides of the sensor base 210. The gap D2 forms a part
of the flow channel 134 formed by the upstream buffer chamber 134a
and the downstream buffer chamber 134b partitioned by the partition
wall 136.
[0141] As described above, the ink is filled in the main case 400
in a state where the main case is almost in vacuum. At this time,
the gap D2 communicating with the upstream buffer chamber 134a or
the downstream buffer chamber 134b can form the flow channel of the
ink. Accordingly, when the ink is fully filled in the upstream
buffer chamber 134a or the downstream buffer chamber 134b, the gap
D2 is filled with the ink and thus bubbles do not remain in the gap
D2. Accordingly, it is possible to prevent the false detection of
the ink end.
[0142] Two opposed positioning portions 410 and 412 of four
positioning portions exist in the extension line of the partition
wall 136 (see FIG. 23) to prevent the flow channel not passing the
sensor cavity 222 from being formed.
[0143] In the example shown in FIGS. 20 to 23, the inlet 135a of
the upstream buffer chamber 134a is located at a position not
opposed to the first hole 212 of the sensor base 210 and the outlet
135b of the downstream buffer chamber 134b is located at a position
not opposed to the second hole 214 of the sensor base 210. The
positions of the inlet 135a and the outlet 135b may be set as shown
in FIGS. 24A and 24B. FIG. 24A is a plan view illustrating the
state equivalent to that of FIG. 19A and FIG. 24B is a sectional
view taken along line A4-A4 of FIG. 24A.
[0144] In the example shown in FIGS. 24A and 24B, the inlet 135a
disposed in the upstream buffer chamber 134a and the outlet 135b
disposed in the downstream buffer chamber 134b are both disposed at
positions opposed to the gap D2 of the opening 402. In this case,
it is preferable that a partition wall 134a1 partitioning the inlet
135a and the upstream buffer chamber 134a and a partition wall
134b1 partitioning the outlet 135b and the downstream buffer
chamber 134b are provided.
[0145] The ink introduced from the inlet 135a travels straightly
and flows in the gap D2. Preferably, the ink is guided by the
partitioning wall 134a1 to flow in the gap D2. Similarly, the ink
discharged from the second hole 216 of the sensor base 210 is
diffused by the downstream buffer chamber 134b to flow in the gap
D2. Preferably, the ink is guided by the partition wall 134b1 to
flow in the gap D2.
[0146] Details of Bypass Channel
[0147] The details of the bypass channel 288 for removing the
bubbles described with reference to FIG. 4 will be described with
reference to FIGS. 25 to 27. FIG. 25 is a view of the case body 102
shown in FIG. 2 as viewed from the film 104. FIG. 26 is an enlarged
plan view of part C in FIG. 25. FIG. 27 is an enlarged perspective
view of part C.
[0148] In FIGS. 26 and 27, the case body 102 is provided with a
tank chamber 260 as a liquid containing chamber, a detour channel
270, and a bubble trapping chamber 282, which have openings opened
on the attachment surface side of the film 104 (FIG. 2),
respectively. The film 104 is thermally welded to a sealing surface
600 close to the surface of the case body 102 to which the film 104
is attached. Accordingly, the openings of the tank chamber 260, the
detour channel 270, and the bubble trapping chamber 282 are
liquid-tightly sealed.
[0149] Here, FIGS. 25 to 26 show a filling posture at the time of
filling the ink cartridge 100 with the ink, instead of the posture
shown in FIG. 2 at the time of consuming (using) the ink. That is,
the posture of the ink cartridge 100 is vertically reverse at the
time of consuming the ink and at the time of filling the ink
cartridge 100. At the time of filling the ink cartridge, the ink is
filled from the ink supply section 110 with the ink supply section
110 facing the upside.
[0150] At the time of filling the ink cartridge, the ink is
introduced into the bubble trapping chamber 282 from the outlet 286
disposed in the vertical upper portion of the bubble trapping
chamber 282. At this time, the ink is discharged to the detour
channel 270 from the inlet 284 disposed in the vertical lower
portion of the bubble trapping chamber 282. That is, at the time of
filling the ink cartridge, the vertical position is reverse to that
at the time of consuming (using) the ink, and the inlet 284 serves
as the outlet and the outlet 286 serves as the inlet. That is, the
functions are also reversed. Hereinafter, in order to avoid the
confusion in title and function at the time of consuming (using)
the ink and at the time of filling the ink cartridge, the inlet 284
and the outlet 286 are referred to as a first communication hole
284 and a second communication hole 286, respectively.
[0151] In the posture shown in FIG. 2 at the time of consuming
(using) the ink, the positional relation of the first and second
communication holes 284 and 286 relative to the bubble trapping
chamber 282 is useful, in that the bubbles can be trapped.
[0152] However, at the time of filling the ink cartridge when the
positional relation is reversed and the inlet and the outlet are
also reversed, the positional relation of the first and second
communication holes 284 and 286 relative to the bubble trapping
chamber 282 is not desirable. The second communication hole 286
shown in FIG. 27 is located in the vertical upper portion of the
bubble trapping chamber 282 and serves as the inlet at the time of
filling the ink cartridge. On the other hand, the first
communication hole 284 shown in FIG. 27 is located in the vertical
lower portion of the bubble trapping chamber 282 and serves as the
outlet at the time of filling the ink cartridge. When the ink is
charged from the second communication hole 286 located in the
vertical upper portion of the bubble trapping chamber 282 and the
ink is discharged from the first communication hole 284 located in
the vertical upper portion of the bubble trapping chamber 282, a
stagnation portion where the bubbles are gathered can be easily
formed in the vertical upper portion of the bubble trapping chamber
282. When there is no place to which the bubbles are delivered, the
bubble trapping chamber 282 is not filled with the ink. In
addition, the bubbles remaining in the bubble trapping chamber 282
move to the ink detector 200 at the time of consuming the ink and
enters the sensor cavity 222, thereby causing the false detection
of the ink end.
[0153] Therefore, a bypass channel 288 for pulling out the bubbles
is provided. The bypass channel 288 is similar to that of
JP-A-2005-022257 and JP-A-2004-306466 in that a part of the film
104 is not welded, but is different from that of JP-A-2005-022257
and JP-A-2004-306466 in installation position and usage or
object.
[0154] As shown in FIG. 27, the bypass channel 288 is guaranteed by
one or more protrusion 610, for example, three protrusions 610 in
this embodiment, protruding from the sealing surface 600 by a
height T. When the protrusions 610 are not welded to the film 104,
a gap formed by the protrusions 610 is guaranteed between the
sealing surface 600 formed on one surface of the case body 102 and
the film 104. The gap serves as the bypass channel 288. More
specifically, the opening of the detour channel 270 is made to
communicate with the opening of the bubble trapping chamber 282
through the non-welded portion (particularly, between two
protrusions 610) of the film 104 from the opening of the bubble
trapping chamber 282, thereby forming the bypass channel 288.
[0155] The bypass channel 288 may be formed by one or more grooves
depressed from the sealing surface 600 by a predetermined depth.
When the grooves are not welded to the film 104, a gap is
guaranteed between the bottom of the groove and the film 104.
[0156] Method of Manufacturing Liquid Container
[0157] A method of manufacturing the ink cartridge 100 (liquid
container) including the case body having the structure shown in
FIGS. 25 to 27 has the following processes. First, the film 104
shown in FIG. 2 is welded to the sealing surface 600 formed on one
surface of the case body 102 having the openings communicating with
the bubble trapping chamber 282 and the detour channel,
respectively. At this time, as described above, the protrusions 610
or the grooves are used as the non-welded portions to which the
film 104 is not welded, so as to guarantee the bypass channel 288.
The welding work is preferably is performed with the ink cartridge
100 placed in the depressurized atmosphere. In this case, useless
air does not enter the ink channel in the ink cartridge 100.
[0158] Then, the posture at the time of consuming the ink (see
FIGS. 2, 3, and 6) is a posture where the ink cartridge 100 is
vertically reversed (see FIGS. 25 to 27). In this posture, the ink
is supplied from the ink supply hole 110. At the time of filling
the ink cartridge, the ink is introduced into the bubble trapping
chamber from the second communication hole 286 disposed in the
vertical upper portion of the bubble trapping chamber 282. The
introduction of the ink is smoothly carried out by depressurizing
the ink channel, in addition to the ink supply pressure. The
filling of the ink cartridge may be carried out while discharging
the air from an opening (not shown) more downstream of the detour
channel 270 for depressurization. The ink in the bubble trapping
chamber 282 is supplied to the detour channel 270 or the tank
chamber 260 downstream therefrom through the first communication
hole 284 located in the vertical lower portion of the bubble
trapping chamber 282.
[0159] At the time of filling the ink cartridge, the bubbles
gathered in the vertical upper portion of the bubble trapping
chamber 282 is delivered from the bubble trapping chamber 282 to
the detour channel 270 through the bypass channel 288 extending
from the opening of the bubble trapping chamber 282 to the opening
of the detour channel 270 through the non-welded portions of the
film 104. The bubbles are discharged to the outside from an end
opening opened to the atmospheric air. When the air is discharged
from the opening downstream of the detour channel 270 for
depressurization, the bubbles are forcibly discharged from the ink
cartridge 100.
[0160] After finishing the ink filling process, the non-welded
portions of the film 104 are welded to close the bypass channel
288. The bypass channel 288 is necessary only at the time of
filling the ink cartridge, but not necessary at the time of
consuming the ink.
[0161] The method of manufacturing the liquid container is not
limited to the ink cartridge 100 shown in FIGS. 25 to 27, and the
application of the liquid container is not limited to the ink
cartridge of the inkjet printing apparatus. The invention may be
applied to a variety of liquid consuming apparatuses having a
liquid ejecting head for ejecting minute ink droplets.
[0162] Specific examples of the liquid consuming apparatuses may
include an apparatus having a coloring material ejecting head used
for manufacturing a color filter of a liquid crystal display and
the like, an apparatus having an electrode material (conductive
paste) ejecting head used for forming electrodes of an organic EL
display, a field emission display (FED), and the like, an apparatus
having a biological organic material ejecting head used for
manufacturing a bio chip, an apparatus having a sample ejecting
head as a precise pipette, and a printing apparatus or a micro
dispenser.
[0163] The liquid container according to the embodiment of the
invention is not limited to the on-carriage type ink cartridge, but
may be a sub tank not mounted on the carriage or an off-carriage
type ink cartridge.
[0164] In the above-mentioned embodiments, the case body of the
liquid detector is also used as the case body of the liquid
container and the sealing rubber or spring described in
JP-A-2006-248201 is excluded, but the invention is not limited to
the configuration. The liquid detector can be configured as a unit
independent of the case body of the liquid container. In this case,
the sealing rubber or spring may not be excluded, but it can
contribute to suppressing the absorption of vibration in the unit
case in minimum and guaranteeing the amplitude of the detected
waveform greatly, even when the unit case increases in size.
[0165] In the above-mentioned embodiment, the liquid ejecting
apparatus may be embodied in a so-called full-line type (line head
type) printer in which the whole shape of the print head 19
corresponds to the length in the width direction (lateral
direction) of a printing sheet (not shown) in the direction
intersecting the transport direction (longitudinal direction) of
the printing sheet (not shown).
[0166] In the above-mentioned embodiment, the liquid ejecting
apparatus is embodied in the inkjet printer 11, but not limited to
the inkjet printer. The invention may be embodied in a liquid
ejecting apparatus spraying or ejecting a liquid (including a
liquid material in which functional material particles are
dispersed or mixed in a liquid and a fluid material such as gel)
other than the ink. Examples thereof include a liquid material
ejecting apparatus ejecting a liquid material including in a
dispersed or dissolved type a material such as electrode material
or coloring material (pixel material) used for manufacturing a
liquid crystal display, an electroluminescence (EL) display, or a
surface emission display, a liquid ejecting apparatus ejecting a
biological organic material used for manufacturing a bio chip, and
a liquid ejecting apparatus ejecting a liquid as a sample in a
precise pipette. Examples thereof can also include a liquid
ejecting apparatus ejecting lubricant to a precise machine such as
a watch or camera with a pin point, a liquid ejecting apparatus
ejecting transparent resin liquid such as UV-curable resin to a
substrate to form minute semi-spherical lenses (optical lenses)
used in optical communication devices, a liquid ejecting apparatus
ejecting etchant such as acid or alkali to etch a substrate and the
like, and a fluid material ejecting apparatus ejecting a fluid
material such as gel (for example, physical gel). The invention can
be applied to at least one kind of the above-mentioned liquid
ejecting apparatuses. In this specification, the "liquid" does not
include a liquid containing only gas, and examples of the liquid
include a liquid material and a fluid material, in addition to
inorganic solvent, organic solvent, solution, liquid-phase resin,
and liquid-phase metal (metal solution).
[0167] The above-mentioned manufacturing method may be applied to a
liquid container having a tank chamber containing a liquid, not the
liquid container in which the bubble trapping chamber 282 is filled
with the liquid. That is, the invention is not limited to trapping
the bubbles at the time of consuming the liquid as described above.
There may be a need for removing the bubbles staying at the time of
filling the liquid container and filling the tank chamber with the
liquid without trapping the bubbles.
[0168] In other words, in the method of manufacturing a liquid
container according to the embodiment of the invention, the posture
for use and the posture for filling may not be necessarily reverse.
In some applications, there may be a need for a structure not
requiring the consumption of liquid or for allowing the first and
second communication holes 284 and 286 in the tank chamber to have
the same positional relation as described above for the reason
other than the bubble trapping. The detour channel 270 is not
essential, but a flow channel connected to the first communication
hole 284 may be used.
[0169] For example, there may be a liquid container as a kind of
buffer in which a liquid always flows in one direction at the time
of filling and consuming. In this case, since the bubbles should be
removed from the tank chamber instead of the bubble trapping
chamber 282, it is not necessary to close the bypass channel 288
after filling the liquid container.
* * * * *