Incremental printing of symbolic information – Ink jet – Fluid or fluid source handling means
Reexamination Certificate
2002-02-08
2004-05-11
Nguyen, Judy (Department: 2861)
Incremental printing of symbolic information
Ink jet
Fluid or fluid source handling means
Reexamination Certificate
active
06733117
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an elastic transformable body for adjusting vapor pressure, a vapor pressure adjustment chamber using the same, an ink-jet recording head having a vapor pressure adjustment device and an ink-jet recording device having the recording head, and more particularly to a vapor pressure adjustment device for adjusting negative pressure generated in a liquid chamber in an ink-jet recording head when discharging ink.
2. Related Background Art
Among recording methods such a printer, the ink-jet recording method to form text or image on a recording medium by discharging ink from a discharging hole (a nozzle) is a non-impact recording method, which enables high-speed recording with high density, so being broadly applied.
A general ink-jet recording device includes an ink-jet recording head, a means for driving a carriage having the ink-jet recording head, a means for carrying the recording medium, and a controller for controlling the driving means. Such an operation to perform recording with moving the carriage is called as a serial type. On the other hand, the manner of performing recording only with carrying a recording medium without moving the recording head is called as a line type. In the line-type ink-jet recording device, the ink-jet recording head has a plurality of nozzles arranged to a width of the recording medium along overall width.
Because discharging ink drop from the nozzles, the ink-jet recording head includes an energy generating means to generate discharging energy exerted to the ink in the nozzles. As the energy generating means, there are used ones of using an electric-mechanical converting element such as piezo element, using electric-thermal converting element such as a heating resistance, or using an electronic wave-mechanical converting element or an electronic wave-thermal converting element for converting electronic wave into mechanical vibration or heat such as an electronic wave laser. Among them, the manner of discharging ink drops by using the thermal energy may arrange the nozzle in very high density, so enabling recording in high resolution. Particularly, the ink-jet recording head using the electric-thermal converting element as the energy generating element is more easily scaled down rather than the one using the electric-mechanical converting element, and furthermore when adapting an IC technique or micro-processing technique with technical advance and improved reliability in the recent semiconductor making field to fully utilize their benefits, there are also advantages of high density, easy mounting and lowered manufacturing costs.
As for supplying the ink to the ink-jet recording head, there are a so-called head tank integrated manner in which an ink tank containing the ink is integrated with the ink-jet recording head, a so-called tube supplying manner in which the ink tank is connected to the ink-jet recording head through a tube, and a so-called pit-in manner in which the ink tank is independently installed to the ink-jet recording head, moving the ink-jet recording head to the ink tank to connect them as required, and then supplying the ink from the ink tank to the ink-jet recording head therebetween.
If increasing capacity of the ink tank to reduce frequency of changing the ink tank, the weight of ink tank is also increased, which is not preferred in the head-tank integrated manner of the serial-type ink-jet recording device, considering that the load exerted on the carriage is increased. Therefore, the serial-type ink-jet recording device using the mass capacity ink tank usually adopts the tube supplying manner or the pit-in manner. Among them, since the pit-in manner requires stopping the recording process during supplying the ink, the tube supplying manner which may operate in longer time is better adopted.
An ink supplying system of the tube supplying type ink-jet recording device is described below with reference to
FIGS. 10A and 10B
.
The ink supplying system shown in
FIGS. 10A and 10B
includes a main tank
304
containing ink
309
therein, a supply unit
305
detachably mounted to the main tank
304
, and a recording head connected through a supply tube
306
to the supply unit
305
.
The supply unit
305
has an ink chamber
305
f
therein. The ink chamber
305
f
is opened by an atmosphere hole
305
g
and at the same time connected to the supply tube
306
through a bottom of the ink chamber
305
f
. The supply unit
305
also has hollow ink supply needles
305
a
of which lower ends are positioned in the ink chamber
305
f
and upper ends are protruded from an upper surface of the supply unit
305
, and the lower ends of the hollow ink supply needles
305
a
are positioned lower than lower ends of atmosphere introduction needles
305
b.
The ink tank
304
has at a bottom two connectors having a rubber stopper to seal the main tank
304
, and has an independent sealed structure with the main tank
304
. When mounting the main tank
304
to the supply unit
305
, the ink supply needles
305
a
and the atmosphere introduction needles
305
b
are respectively inserted in the main tank
304
through the connectors. Since positions of the lower ends of the ink supply needles
305
a
and the atmosphere introduction needles
305
b
are set as above, the ink in the main tank
304
is supplied to the ink chamber
305
f
through the ink supply needles
305
a
, and the atmosphere is introduced in the main tank
304
through the atmosphere introduction needles
305
b
to supplement the pressure decrease in the main tank
304
. If the ink is supplied in the ink chamber
305
f
up to the level that a lower end of the atmosphere introduction needles
305
b
are soaked in the ink, the atmosphere is not introduced in the main tank
304
so that supplying ink from the ink tank
304
to the ink chamber
305
f
is stopped.
The recording head
301
has a sub tank
301
b
for accumulating a constant amount of ink as an ink container, an ink discharging unit
301
g
in which a plurality of nozzles for discharging ink are arranged, and a flow channel
301
f
connecting the sub tank
301
b
to the ink discharging unit
301
g
. In the ink discharging unit
301
g
, the nozzle has an open channel downward and the ink is discharged downward. In each nozzle of the ink discharging unit
301
g
, the above-described energy generating means is installed. The sub tank
301
b
is positioned above the ink discharging unit
301
g
, the supply tube
306
is positioned above the ink discharging unit
301
g
, and the supply tube
306
is connected to the sub tank
301
b
. Between the sub tank
301
b
and a flow channel
301
f
, there is attached a filter
301
c
having a fine mesh structure to prevent the nozzle from plugging caused from that minute impurities in the ink are infiltrated into the ink discharging unit
301
g.
An area of the filter
301
c
is set to regulate pressure loss less than an allowance value. The pressure loss at the filter
301
c
is increased as the mesh of the filter
301
c
is finer and as a flow rate of the ink passing the filter
301
c
is larger. On the contrary, the area of the filter
301
c
is in inverse proportion. The recent recording head of multi-nozzle and small head tends to increase the pressure loss, so the size of the filter
301
c
is made as larger as possible to restrain the increase of pressure loss.
On an upper surface of the recording head
301
, installed is an elastic member
321
having an appearance of an approximate rectangular shape in order to form a pressure adjustment chamber
322
for adjusting pressure in the sub tank
301
b
by absorbing abrupt change of pressure in the sub tank
301
b
. The pressure adjustment chamber
322
is connected only into the sub tank
301
through an opening
301
d
formed on an upper wall of the recording head
301
. As the elastic member
321
transforms according to the pressure change in the sub tank
301
b
, volume of the pressure adjustment chamber
322
changes to absorb the pressure change
Goto Akira
Iijima Yasushi
Koizumi Yutaka
Kono Takeshi
Maeda Hiroyuki
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