Information
-
Patent Grant
-
6540341
-
Patent Number
6,540,341
-
Date Filed
Tuesday, December 5, 200024 years ago
-
Date Issued
Tuesday, April 1, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 347 85
- 347 86
- 347 87
- 347 92
- 222 105
- 222 206
- 222 212
-
International Classifications
-
-
Disclaimer
Terminal disclaimer
Abstract
The ink cartridge is provided with a pressure controller to regulate the inner pressure therein by atmospheric pressure while the ink stored in the ink cartridge is gradually drained off. The ink is stored in a container with negative pressure therein, and at least one through hole formed on the container is used to connect to the atmosphere, and at least one recess is formed on the inner wall of the through hole. The pressure controller has a plug movably disposed on the through hole and the recesses. The recesses are used as a channel to allow the entrance of the atmospheric air, and the plug can be automatically moved so as to enlarge the clearance between the plug and the through hole while the ink stored in the ink cartridge is gradually drained off. The inputted air can effectively reduce the negative pressure in the container, and therefore the printing process of the ink cartridge can be proceeding steadily.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an ink cartridge. More particularly, this invention relates to an ink cartridge provided with a pressure controller so as to precisely control ink pressure therein.
2. Description of Prior Art
In the field of the printing device, “Drop-On-Demand” is a general control method used to control the flow rate of the ink dropping on the printing surface. For example, thermal bubble type printhead and piezoelectric type printhead are two classic outputting devices designed by “Drop-On-Demand”.
Thermal bubble type printhead has a film resistor. The ink droplet is immediately vaporized and the expansion effect is generated as the film resistor is energized, and then parts of ink droplet is jetted out off the nozzle, and finally dropping on the printing surface. The thermal bubble type printhead controlled by the “Drop-On-Demand” will cause the ink oozing through the nozzle if it is not taken a control mechanism—to generate a predetermined negative pressure in the ink cartridge while the printing procedure is stopped.
Some of ink cartridges are provided with a “regulator”, disposed in the ink container to generate negative pressure therein. In general, a regulator such as air bag is used to change the volume of the ink container by expansion or contraction so that the adequate negative pressure can be generated.
However, the volume in the ink container cannot be further increased once the maximum degree of the expansible air bag is limited. When this occurs the air bag cannot be further expanded and the ink stored in the container continues draining out, the negative pressure is relatively increased over the predetermined value. Then, the ink supply of the printhead will be abnormally terminated and then the remaining ink cannot be used.
For solving the above problem, some printing devices are applied with “bubble generator” to control the negative pressure in the cartridge. The bubble generator is provided with a designed through hole which is connected the inner space of cartridge to the ambient atmosphere and used to generate “liquid seal” with capillary forces so as to keep the ink remaining in the cartridge.
When the negative pressure is raising up to a preset value and it is larger than the capillary forces, the atmospheric air from the ambient atmosphere is quickly sucked into the ink cartridge via the through hole and scrubbed into bubbles dispersing in the ink. Then, the negative pressure can be immediately decreased by the generation of these bubbles, and then the liquid seal can be rebuild as the negative pressure is smaller than the capillary forces.
There are several crucial functions for the bubble generator. First, the negative pressure has to be precisely controlled as the bubbles are generated. Second, the variation of negative pressure in the cartridge has to be precisely controlled within a predetermined range, and the generation of the bubbles has to be terminated when the negative pressure is lower to a predetermined value. Third, “self-wetting capability” has to be provided. As the ink is about to be used up or the position of the cartridge is altered, for example, resulting in the bubble generator is not merged in the ink, the self-wetting capability of the bubble generator can effectively prevent the ambient air from entering into the cartridge.
U.S. Pat. No. 5,526,030 discloses the bubble generator provided with a through hole and a packing member. Several ribs are protruded from the inner wall of the through hole and used to position the packing member within the through hole. The packing member cannot be moved or rotated within the through hole and the gaps between the packing member and the inner wall are used to generate bubbles. The '030 case further comprises a liquid sealing device and is configured with the ability of self-wetting. For generating desirable negative in the ink pen, the annular orifice between the fixed sphere and the inside of the boss must be precisely calculated and manufactured. This increases the production cost and difficulty of fabricating the device.
SUMMARY OF THE INVENTION
To solve the above problem, the primary object of this invention is to provide an ink cartridge comprising a pressure controller so as to adjust the inner pressure therein by atmospheric pressure while the ink stored in the ink cartridge is gradually drained off. The ink cartridge has a container used to store ink with negative pressure therein. At least one through hole is formed on the container and used to connect to the atmosphere, and at least one recess is formed on the inner wall of the through hole. The pressure controller has a plug movably disposed on the through hole and the recess. The recess is designed to regulate the pressure difference between the ink in the container and the atmosphere, and the plug can be automatically shifted to enlarge the clearance between the plug and the through hole while the ink stored in the ink cartridge is gradually drained off.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can be more fully understood by reading the subsequent detailed description and examples with reference made to accompanying drawings in which:
FIG. 1A
is a plane view showing the inner structure of an ink cartridge (
1
) according to a first embodiment of the present invention;
FIG. 1B
is an enlarged view showing the structure of a pressure controller (R
1
) of
FIG. 1A
;
FIG. 1C
is a cross-sectioned view according to the line A—A of
FIG. 1B
;
FIG. 2A
is a plane view showing the inner structure of the ink cartridge (
1
′) according to a second embodiment of the present invention;
FIG. 2B
is an enlarged view showing the structure of a pressure controller (R
1
′) of
FIG. 2A
;
FIG. 3A
is a plane view showing the inner structure of the ink cartridge (
1
″) according to a third embodiment of the present invention;
FIG. 3B
is an enlarged view showing the structure of a pressure controller (R
2
) of
FIG. 3A
;
FIG. 3C
is a plan view showing the pressure controller (R
2
) being actuated of
FIG. 3B
;
FIG. 4
is a plan view showing another derivative example according to
FIG. 1C
;
FIG. 5A
is a plan view showing the structure of a pressure controller (R′) according to a fourth embodiment of the present invention;
FIG. 5B
is a plan view showing the structure of a pressure controller (R″) according to a fifth embodiment of the present invention; and
FIG. 5C
is a plan view showing the structure of a pressure controller (R′″) according to a sixth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to
FIG. 1A
, a plane view shows the inner structure of an ink cartridge
1
according a first embodiment of the present invention.
The ink cartridge
1
comprises a container
10
, an expansible chamber
11
, a movable plate
12
, a spring
13
and a pressure controller R
1
. The ink W is in the container
10
with negative pressure, and a guiding path
103
H is formed on the bottom of the container
10
. A printhead
2
located outside of the container
10
is connected to the guiding path
103
H, wherein the ink W can be drained out by the printhead
2
through the guiding path
103
H. The expansible chamber
11
, the movable plate
12
and the spring
13
are partially immersed in the stored ink W, and the pressure controller R
1
located at the bottom of the container
10
is fully immersed in the stored ink W.
The container
10
comprises a body
10
-
1
and a cover
10
-
2
. The cover
10
-
2
is used to connect the body
10
-
1
on the top and is formed with a hole
104
H which can be sealed by a cap
104
P. The ink W is loaded into the container
10
through the hole
104
H. The body
10
-
1
is composed of two side plates
101
,
102
and a bottom plate
103
. The expansible chamber
11
is installed in the container
10
and communicated to a gas source
3
(such as atmospheric gas) by a conduit
110
. The movable plate
12
is disposed between the spring
13
and the expansible chamber
11
, and the spring
13
is disposed between the side plate
101
and the movable plate
12
. The movable plate
12
is attached on the expansible chamber
11
, and one end of the spring
13
is connected to the side plate
101
, and the another end of the spring
13
is connected to the movable plate
12
. Therefore, the expansible chamber
11
can be used to move the movable plate
12
, and the movement of the .movable plate
12
is limited by the spring
13
.
Referring also to
FIG. 1B
, an enlarged view shows the inner structure of the pressure controller R
1
of FIG.
1
A.
The pressure controller R
1
can be a set or module, which can be separably installed on the container
10
or directed or formed on the container
10
as this preferred embodiment. The pressure controller R
1
comprises a base
14
-
1
, a plug
15
, a plate
16
-
1
, a connector
17
and a resilient element
18
.
The base
14
-
1
provided with a through hole
140
-
1
is integrally formed on the bottom plate
103
. The through hole
140
-
1
is used to connect the ink W in the container
10
and the atmosphere, as showed in FIG.
1
A. One opening near the inner space of the container
10
of the through hole
140
-
1
is shaped with a semispherical space
140
U.
The plate
16
-
1
is fixed on the bottom plate
103
by the connector
17
and used as a cantilever arm extending above the through hole
140
-
1
of the base
14
-
1
. The resilient element
18
is a spring used to connect to the plate
16
-
1
and provided with a contacting end
180
faced toward the semispherical space
140
U. The plug
15
is a ball disposed between the contacting end
180
of the resilient element
18
and the base
14
-
1
, wherein the plug
15
is pushed by the resilient element
18
and uniformly pressed on the protrusions
141
P.
Referring to
FIG. 1C
, the cross-sectional view by the line A—A of
FIG. 1B
shows the geometrical relationships between the plug
15
and the base
14
-
1
. Three recesses
141
V are formed on the inner wall of the through hole
140
-
1
and separated by the protrusions
141
P. Thus, three clearances G (recesses
141
V) are formed among the base
14
-
1
, the plug
15
and the protrusions
141
P at the present situation.
When the printing process is underway and the ink W in the container
10
is gradually drained off, the negative pressure in the container
10
is gradually increased and the back pressure located at the plug
15
is relatively elevated. Once the negative pressure in the container
10
is increased over a critical value, the atmospheric air can be immediately sucked into the container
10
via the through hole
140
-
1
and the clearances G and it is dispersed into the ink W in the form of bubbles. Then, the negative pressure in the container
10
can be immediately increased.
Once the negative pressure in the container
10
is greatly larger than the pressure of the atmospheric air and it cannot be effectively increased by the aforementioned method, the negative pressure pushes the plug
15
pressing on the resilient member
18
toward the plate
16
-
1
. Then, the clearance between the plug
15
and the through hole
140
-
1
is enlarged and it allows more air entering the container
10
to reduce the negative pressure in the container
10
.
In addition, owing to the expansible chamber
11
is connected to the atmospheric gas source
3
, the pressure in the expansible chamber
11
is decreased when the ink cartridge
1
is moved from a lower altitude to a higher altitude such as transported by flight. Thus, the pressure in the expansible chamber
11
is decreased by the atmospheric gas source
3
and the expansible chamber
11
is relatively contracted. With the decreasing of the inner pressure of the container
10
, the air can be immediately sucked into the container
10
by passing the clearance G, and then the negative pressure in the container
10
can be immediately reduced and there is no ink oozed from the printhead
2
. With the regulation of the clearances G between the inside and outside of the container
2
, therefore, the printing process can be proceeded with stable, and the negative pressure can be precisely controlled within a designed range by regulating the inflow rate of air outside.
Referring to FIG.
2
A and
FIG. 2B
,
FIG. 2A
shows the inner structure of the ink cartridge
1
′ according to a second embodiment of the present invention, and
FIG. 2B
shows the structure of a pressure controller R
1
′ of FIG.
2
A.
The second embodiment differs from the first embodiment in that the spring
18
in
FIG. 1A
is removed, and a reed
16
-
2
replaces the plate
16
-
1
. The same elements in FIG.
2
A and
FIG. 2B
are denoted the same symbols as the first embodiment. The reed
16
-
2
, a resilient element, has a contacting end
160
used for pressing the plug
15
on the protrusions
141
P
1
of the base
14
-
1
and limiting the plug
15
at the semispherical space
140
U.
Referring to
FIG. 3A
, a plan view shows the inner structure of the ink cartridge
1
″ according to a third embodiment of the present invention. The third embodiment differs from the first and the second embodiments in that the movable plate
12
is used to replace the spring
18
(
FIG. 1A
) or reed
16
-
2
(
FIG. 2A
) to control the movement of the plug
15
.
Referring to FIG.
3
B and
FIG. 3C
,
FIG. 3B
shows the detailed structure of a pressure controller R
2
of
FIG. 3A
, and
FIG. 3C
shows the pressure controller R
2
being actuated by the movable plate
12
.
As shown in
FIG. 3B
, the pressure controller R
2
has a base
14
-
2
formed with a through hole
140
-
2
, and the through hole
140
-
2
is provided with a space
140
U-
2
and a plurality of protrusions
141
P
2
therein. A plate
16
′ is used as a cantilever disposed above the through hole
140
-
2
and it is composed of two portions
16
′-
1
and
16
′-
2
. The portion
16
′-
1
has a contacting end
160
′ faced toward the through hole
140
-
2
and is fixed on the bottom plate
103
by the connector
17
, so that the plug
15
can be uniformly pressed on the protrusions
142
P
2
by the portion
16
′-
1
.
In
FIG. 3C
, as the expansible chamber
11
is inflated with gas supplied from the gas source
3
, the movable plate
12
is moved toward the plate
16
′ and then contacts the portion
16
′-
2
of the plate
16
′. Then, the inflating expansible chamber
11
causes the moving plate
12
pressing on the plate
16
′ and results in the plate
16
′ substantially rotated above the fixed connector
17
. The portion
16
′-
1
is shifted with a slant angle away from the base
14
-
2
and the space between the plate
16
′ and the base
14
-
2
is enlarged. Then, the plug
15
is not fixedly pressed by the plate
16
′ and it can locally move between the plate
16
′ and the base
14
-
2
, and the clearance between the plug
15
and the through hole
140
-
2
can be enlarged. Although the plug
15
can freely move within the space
140
U
2
, the plug
15
is still constrained between the plate
16
′ and the base
14
-
2
. Therefore, the atmospheric air can be immediately sucked into the container
10
via the enlarged clearances G and it is dispersed into the ink W in the form of bubbles.
Once the plug
15
is stuck as the plate
16
′ is pressed, the atmospheric air still can be sucked into the container
10
via the minimum clearances among the plug
15
and the protrusions
141
P
2
and dispersed itself into the ink W in the form of bubbles.
Referring to
FIG. 4
, a plan view shows another derivative example according to FIG.
1
C. In
FIG. 4
, three grooves
141
R, instead of the protrusions
141
P, are formed on the inner wall of the through hole
140
-
1
, and therefore three clearances G
2
are formed between the base
14
-
1
and the plug
15
as the plug
15
is pressed on the base
14
-
1
.
Referring to FIGS.
5
A˜
5
C, three plan views respectively show the structure of three different types of pressure controller R′, R″, R′″ according to a fourth, fifth and sixth embodiment of the present invention. Three spaces
140
U′,
140
U″,
140
U′″ with different shapes are respectively provided in a through hole
140
′ of a base
14
′, a through hole
140
″ of a base
14
″ and a through hole
140
′″ of a base
14
′″. Protrusions
141
P′,
141
P″,
141
P′″ are respectively formed on the spaces
140
U′,
140
U″,
140
U′″.
In
FIG. 5A
, the plug
15
is pressed on the protrusion
141
P′and located in the space
140
U′ by the plate
16
. In a
FIG. 5B
, the plug
15
is pressed on the protrusion
141
P″ and located in the space
140
U″ by the plate
16
. In
FIG. 5C
, the plug
15
is pressed on the protrusions
141
P′″ and located in the space
140
U′″ by the plate
16
. Once the negative pressure in the container
10
is increased, the clearances between the plug
15
and the through hole
140
′ (
140
″ or
14
′″) allow the atmospheric air to enter the container
10
.
While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
Claims
- 1. An apparatus for controlling an ink cartridge having ink stored under negative pressure therein, comprising:a base installed on said ink cartridge, having a through hole used for connecting the ink stored in said ink cartridge to an atmosphere and provided with an inner wall formed with at least one recess thereon; a resilient element disposed next to said base and provided with a contacting end; and a plug movably disposed between said contacting end of said resilient element and said through hole, used for regulating pressure difference between the ink stored in said ink cartridge and the atmosphere.
- 2. The apparatus as claimed in claim 1, wherein said base is integrally formed on said ink cartridge.
- 3. The apparatus as claimed in claim 2, wherein said resilient element is a spring.
- 4. The apparatus as claimed in claim 2, wherein said resilient element is a reed.
- 5. The apparatus as claimed in claim 1, wherein said ink cartridge further comprises a chamber to control said resilient element.
- 6. The apparatus as claimed in claim 1, wherein a cantilever plate is further provided and disposed in said container, and said resilient element is extended from said cantilever plate.
- 7. An ink cartridge, comprising:a container used for storing ink with negative pressure therein, having at least one through hole connected to the atmosphere and provided with an inner wall formed with at least one recess thereon; a resilient element disposed next to said through hole and provided with a contacting end; and a pressure controller used for regulating pressure between the ink stored in said container and the atmosphere, having a plug movably disposed between said contacting end of said resilient element and said through hole.
- 8. The ink cartridge as claimed in claim 7, wherein said resilient element is a spring.
- 9. The ink cartridge as claimed in claim 8, wherein said resilient element is a reed.
- 10. The ink cartridge as claimed in claim 9, further comprising a chamber to control said resilient element.
- 11. The apparatus as claimed in claim 6, wherein a cantilever plate is further provided and disposed in said container, and said resilient element is extended from said cantilever plate.
Priority Claims (1)
Number |
Date |
Country |
Kind |
89101544 A |
Jan 2000 |
TW |
|
US Referenced Citations (5)
Number |
Name |
Date |
Kind |
4992802 |
Dion et al. |
Feb 1991 |
A |
5526030 |
Baldwin et al. |
Jun 1996 |
A |
5608437 |
Iwata et al. |
Mar 1997 |
A |
6186620 |
Hsieh et al. |
Feb 2001 |
B1 |
6213598 |
Hou et al. |
Apr 2001 |
B1 |