Head cartridge assembly for ink-jet printer

A head cartridge for an ink-jet printer is disclosed. This head cartridge includes an ink storage inside an ink vessel body, a flexible body installed inside the ink storage to hold and deliver ink, an ink filter located on the lower portion inside the ink storage, a heating device with heating elements located under the ink filter to heat and evaporate ink in the ink storage, a nozzle having a spray hole with multiple of apertures for spraying ink particles onto the print media by vapor pressure created by the heating device and a cap attached to the top of the ink vessel by an ultrasonic bonding process. An ink filling hole for the head assembly is located on the cap of the head cartridge, and a plug assembly is mounted on an opening formed on one side of the cap. In the plug assembly, a lid for plugging the ink filling hole, a projection used for fixing the plug assembly to the cap, and a locking portion for locking the head cartridge in a carriage of the printer's main body are integrally formed.

FIELD OF THE INVENTION 
The present invention generally relates to an ink-jet printer. More 
particularly, it relates to a head cartridge assembly for an ink-jet 
printer which has an assembly for closing an ink filling hole located in 
the head cartridge and for locking the head cartridge into a print 
carriage within the printer's main body, and is a cartridge that can be 
reused by refilling ink after removing the assembly when the cartridge is 
empty. 
BACKGROUND OF THE INVENTION 
Sealing mechanisms are employed on cartridges for ink jet printers. For 
example, U.S. Pat. No. 5,572,852 for a Method For Opening, Refilling and 
Sealing a Cartridge and U.S. Pat. No. 5,400,573 for a Kit and Method For 
Opening, Refilling and Sealing a Cartridge to Crystal et al. both disclose 
a method for opening, refilling and sealing an ink cartridge. A spherical 
plug is used to reseal the opening after refilling the ink cartridge with 
ink. 
U.S. Pat. No. 5,488,400 for a Method For Refilling Ink Jet Cartridges to 
Crystal et al. discloses another method for refilling ink jet cartridges 
and resealing them after being refilled An aperture used for refilling the 
cartridge with ink is sealed with a seal or plug after refilling the 
cartridge with ink. 
U.S. Pat. No. 5,572,245 for a Protective Cover Apparatus For An Ink-Jet Pen 
to Cowger discloses a protective cover apparatus for ink jet pen. The 
protective cover apparatus is used to protect the ink pen head against 
damage caused by the ingress of dirt and debris, the accumulation of 
solidification of ink, and the like. 
SUMMARY OF THE INVENTION 
It is an object to provide a head cartridge for an ink-jet printer which 
has an assembly for preventing dirt from getting into an ink filling hole 
so as to avoid damage thereto. 
It is another object to provide a head cartridge for an ink-jet printer 
which has an ink filling hole for refilling the proper ink into its ink 
storage using an ink injector, and an assembly for inserting into the ink 
filling hole. Users can buy the invented head cartridge and ink injector 
for further use, thus the present invention may create cost savings while 
increasing the reliability of the product. 
It is yet another object to provide a plug for a cartridge of an ink jet 
printer that inserts into the ink filling hole and the plug is clipped on 
to the cartridge externally. 
In order to realize the above objectives, the present invention involves a 
head cartridge for an ink-jet printer having an ink storage inside an ink 
vessel body, a flexible body installed inside the ink storage to hold and 
deliver ink, an ink filter located on the lower portion inside the ink 
storage, a heating device with heating elements located under the ink 
filter to heat and evaporate ink in the ink storage, a nozzle having a 
spray hole with multiple of apertures for spraying ink particles onto the 
print media by vapor pressure created by the heating device and a cap 
attached to the top of the ink vessel by an ultrasonic bonding process. An 
ink filling hole for the head assembly is located on the cap of the head 
cartridge, and a plug assembly is mounted on an opening formed on one side 
of the cap. In the plug assembly, a lid for inserting into the ink filling 
hole, a projection used for fixing the plug assembly to the cap, and a 
locking portion for locking the head cartridge in a carriage of the 
printer's main body are integrally formed.

DETAILED DESCRIPTION OF THE INVENTION 
A head cartridge 21, for an ink-jet printer, is installed on a carriage 
that slides right and left on a rail inside the printer's main body, and 
includes an ink storage 23 inside ink vessel body 22. A flexible body 24 
is installed within ink storage 23, and an ink filter 26 is located on the 
bottom of the interior of ink storage 23. A heating device 27 and a nozzle 
28 containing a spray hole 29 are located under ink filter 26. A cap 30 is 
attached to ink vessel body 22 by an ultrasonic bonding process. An ink 
filling hole 25 is drilled in the middle of cap 30, through which ink 
storage 23 is refilled with ink by ink injector 32. A locking portion 31 
is formed on one side of cap 30, protruding upward so as to mate with the 
main body's carriage (not illustrated). 
Head cartridge 21 includes heating device 27, with an array of heating 
elements for heating ink; nozzle 28, having a spray hole 29 with multiple 
orifices for spraying ink particles onto the print media by heating and 
vaporizing them; an electrode section, which is the means for furnishing 
electrical power to heating device 27; a flexible body in 24, for ink 
storage 23; and cap 30 attached to ink vessel body 22, which provides 
protection for flexible body 24. Ink particles, introduced to the heating 
elements of heating device 27, are vaporized by heat to produce a vapor 
pressure. This vapor pressure causes these ink particles to spray onto 
print media through spray hole 29. As a negative pressure acts on spray 
hole 29, by the meniscus phenomenon, the pressure on flexible body 24 that 
is being compressed to ink filter 26 causes a creation of positive 
pressure, atmospheric pressure, by a hole connected with the atmosphere so 
that ink particles are introduced to the heating elements of heating 
device 27 to use ink on print media. 
When the ink in flexible body 24 is exhausted through a repetition of this 
cycle, a user separates head cartridge 21 from the carriage and replaces 
head cartridge 21 with new one, or refills the ink storage 23 through ink 
filling hole 25 located on cap 30. The ink-jet printer's head cartridge 21 
is disposable, and parts other than head cartridge 21 may affect the life 
of the printer head. In general, the life of the head is the period 
between being mounted in the printer and its internal heating device's 
being damaged by chemical interaction and electrolytic actions with ink 
particles whereby the nozzle fails to spray ink particles. The heating 
device uses about 35 grams of the original 43 grams of ink, and 6 to 10 
grams of ink remain on the flexible body. The head cartridge 21 is 
designed to be reused six times by refilling ink. However, the cartridge 
failures due to the spray hole being plugged by dirt may not be solved. 
When the spray hole is plugged, the problem can be solved by suction 
pumping and forced spraying during the initial operating state. However, 
such a head cartridge is of a construction wherein ink is not refilled and 
is to be discarded, which creates a large expense. The disparity between 
the head's heating device and forcibly refilled similar ink causes 
poor-quality printing, thereby decreasing the reliability of the printer. 
In addition, the use of similar ink may damage the printer components. 
Turning to FIGS. 2 and 3, the ink jet printer cartridge of the present 
invention is shown. A head cartridge 1, for an ink-jet printer is attached 
to a carriage in the printer's main body, and has an ink storage 3 located 
inside an ink vessel body 2. Ink storage 3 includes a flexible body 4 for 
ink storage and ink conveyance, an ink filter 6 located on a lower portion 
inside of ink storage 3, a heating device 7 installed under ink filter 6 
to heat and vaporize ink, and a nozzle 8 having a spray hole 9 for 
spraying ink particles onto the print media. An ink filling hole 5 and an 
opening 11 are formed on a cap 10 which is attached to ink vessel body 2 
by an ultrasonic bonding process. On cap 10 is mounted a plug assembly 12 
including a lid 13, for inserting into ink filling hole 5, and also 
including a locking portion 14 for locking the plug assembly 12 to the 
cartridge. More specifically, plug assembly 12 consists of lid 13 formed 
on one end to protrude downward, locking portion 14 formed on the other 
end to lock the plug assembly 12 to cap 10 of head cartridge 1, and a lug 
15 under locking portion 14 which locks into opening 11. The lug 15 
couples the plug assembly 12 to the head cartridge 1. Plug assembly 12 has 
a concave portion 16 on the top which is located away from lid 13 so as to 
facilitate mounting or removing plug assembly 12 from cap 10. Concave 
portion 16 is designed to be cut easily. The locking portion 14 locks the 
head cartridge 1 to the carriage of the printer's main body. 
Ink storage 3 holds flexible body 4 and ink. A sponge serves as flexible 
body 4. Ink filing hole 5 may be used as an air hole, and an extra air 
hole may be formed on cap 10 for equalizing the internal pressure with 
atmospheric pressure. Ink filling hole 5 is of 1 to 5 millimeters (mm) in 
diameter, though 1.5 millimeters is the optimum size. The ink filling hole 
5 can be used as an air hole because the lid 13 is formed to be inserted 
into ink filling hole 5 in a manner which leaves a gap between lid 13 and 
an inner wall of ink filling hole 5. The gap is too small to allow dirt 
into the cap 10 and is large enough to allow air to pass into and out from 
cap 10. 
The following description relates to the operation and effect of the 
present invention as shown in FIGS. 2 and 3. Head cartridge 1 includes: 
heating device 7, with multiple of heating elements for heating ink; 
nozzle 8, having a spray hole 9 with multiple of orifices for spraying ink 
particles onto the print media, and electrical contacts for supplying 
energy to heating device 7. Head cartridge 1 also includes: ink filter 6, 
for filtrating the ink flowing into heating device 7; flexible body 4 for 
storing ink in ink storage 3, and cap 10 fixed to the top of ink vessel 
body 2 which provides protection for flexible body 4. Plug assembly 12 is 
mounted on cap 10, and its lid 13 fits into ink filling hole 5 and lug 15 
mates with opening 11 of cap 10. Locking portion 14 of plug assembly 12 
securely couples with the carriage. 
In head cartridge 1, the ink flowing into the heating elements of heating 
device 7, is vaporized by the heat, and the vapor pressure created at the 
time of the vaporization, forces ink particles to spray onto the print 
media through spray hole 9. Simultaneously, a negative pressure is created 
by the meniscus phenomenon around spray hole 9, the pressure acting on 
flexible body 4 that is being compressed to ink filter 6 causes a creation 
of positive pressure, atmospheric pressure, by an air hole connected with 
the atmosphere, which makes ink particles contained in flexible body 4 be 
introduced to heating device 7's heating elements thereby being sprayed on 
print media through spray hole 9 of nozzle 8. Turn now to FIG. 4, which 
shows a detailed view of an air hole, in accordance with the principles of 
the present invention. The FIG. 4 shows air hole 100 having a size 
allowing air to pass while not allowing contaminants to pass. 
A predetermined amount of the ink of flexible body 4 is used by the 
repetition of the above cycle, thereby giving rise to deletion of 
characters during printing. At this point, if head cartridge 1 is not 
removed from the main body's carriage, lid 13 can be separated from plug 
assembly 12 by cutting along groove 16 in plug assembly 12 so that locking 
portion 14 of plug assembly 12 is easily detached from the printer's 
carriage, and head cartridge 1 is then removed therefrom to refill ink 
through ink filling hole 5 using ink injector 17. The groove 16 is loaded 
with tension. 
When the ink in head cartridge 1 is used up, head cartridge 1 is separated 
from the main body's carriage, and plug assembly 12 is removed from cap 
10. If 30 to 35 grams ink, the amount of ink used, is injected, using ink 
injector 17, through ink filling hole 5, it is delivered to and held in 
flexible body 4 by capillary action. If excess ink is injected to ink 
storage 3, it overflows through spray hole 9 of nozzle 8. Therefore, 
refilling ink that is just as much as the amount of ink used in flexible 
body 4 can prevent overflow of ink and contamination, and it is good to 
refill ink with the application of a tape to spray hole 9 of heating 
device 7. 
After refilling head cartridge 1, plug assembly 12 plugs ink filling hole 5 
by inserting lug 15, of plug assembly 12, into opening 11. If head 
cartridge 1 is reinstalled in the printer after removing tape applied to 
spray hole 9, it is initialized by suction pumping and forced spraying at 
its initial operating state. The lid 13 of plug assembly 12 is inserted 
into the ink filling hole 5 to prevent dirt and dust from getting into ink 
storage 3, thus avoiding the cartridge failure due to clogging of spray 
hole 9. In addition, a user purchasing the inventive head cartridge 1, 
conveniently, also has several ink injectors for further refilling the 
cartridge. 
As described above, the invented head cartridge for an ink-jet printer, 
mounted on the printer's carriage, has a plug assembly designed to be 
inserted into the ink filling hole, thus preventing cartridge failure due 
to dirt and dust. Once the head cartridge is empty, the head cartridge is 
reused by refilling the proper amount of ink using an ink injector through 
the ink filling hole after removing the plug assembly, which assures a 
long life for the head cartridge. Moreover, selling the invented head 
cartridge along with the ink injector may offer great convenience and 
cost-effectiveness. 
Therefore, it should be understood that the present invention is not 
limited to the particular embodiment disclosed herein as the best mode 
contemplated for carrying out the present invention, but rather that the 
present invention is not limited to the specific embodiments described in 
this specification except as defined in the appended claims.