Incremental printing of symbolic information – Ink jet – Fluid or fluid source handling means
Reexamination Certificate
2002-08-21
2004-10-05
Vo, Anh T. N. (Department: 2861)
Incremental printing of symbolic information
Ink jet
Fluid or fluid source handling means
Reexamination Certificate
active
06799840
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an inkjet recording apparatus wherein recording is carried out by discharging ink from a recording head, particularly to an ink supply mechanism between two ink tanks, which are connectable to and removable from each other via joint portions.
2. Related Background Art
Conventionally, there have been the following 3 types of system for supplying ink to a recording head of an inkjet recording apparatus.
(a) Head Cartridge System
As shown in
FIG. 8
, in the head cartridge system, a head cartridge
103
, integrated with a recording head
101
for discharging ink and an ink tank
102
for storing ink to be supplied to the recording head
101
, is mounted detachably on a carriage
104
which is supported slidably by a guide shaft
105
. The carriage is reciprocated along the guide shaft
105
by a carriage drive mechanism, which is not shown in the
FIG. 8. A
platen
106
is disposed at a position opposite to the recording head
101
, and a record sheet
107
such as paper and film is transferred on the platen
106
perpendicular to the moving direction of the carriage
104
by a record sheet transfer mechanism, which is not shown in the FIG.
8
.
And then, while repeating intermittent supply (supplementary scanning) of the record sheet
107
and reciprocating motion (main scanning) of the carriage
104
, desired letters and images are recorded on the record sheet
107
by driving the recording head
101
and discharging ink from the recording head
101
, on the basis of recording signals. In this system, the ink in the ink tank
102
is supplied directly into the recording head
101
.
(b) Tank Cartridge System
As shown in
FIG. 9
, in the tank cartridge system, only a recording head
111
is mounted on a carriage
114
. A tank cartridge
112
for storing ink is disposed on a main body side of an ink jet recording apparatus. The recording head
111
and the tank cartridge
112
are connected each other with a flexible ink supply tube
113
which can follow the movement of the carriage
114
along a guide shaft
115
, and the ink in the tank cartridge
112
is supplied into the recording head
111
via the ink supply tube
113
.
(c) Pit-In System
As shown in
FIG. 10
, in the pit-in system, a recording head
121
and a sub-tank
122
are mounted on a cartridge
124
. The recording head
121
and the sub-tank
122
are integrated in a one body, and the ink in the sub-tank is supplied directly into the recording head
121
. On the other hand, a main tank
123
, whose capacity of ink is larger than that of the sub-tank
122
, is disposed on a main body side of an inkjet recording apparatus. On the main tank
123
provided is a joint portion
123
a
, which is communicated with an ink inlet portion
122
a
provided on the sub-tank
122
when the sub-tank is moved to the facing position against the main tank
123
.
When the volume of the ink in the sub-tank
122
decreases less than the predetermined amount as a result of consumption of the ink in the sub-tank
122
by discharging ink from the recording head
121
, a carriage
124
is moved along a guide shaft
125
to the position where the ink inlet portion
122
a
faces the joint portion
123
a
. At the position, the ink inlet portion
122
a
and the joint portion
123
a
are communicated with each other to supply ink from the main tank
123
into the sub-tank
122
.
However, there have been problems shown below in the conventional system of supplying ink described above.
In the head cartridge system, it is essential to make a capacity of the ink tank larger in order to reduce exchange frequency of the head cartridge, namely, in order to increase the number of sheets, which can be recorded by a single head cartridge. Since the head cartridge is mounted on the carriage, however, the increase in capacity of the ink tank results in the increase in space necessary for scanning the carriage to thereby require the enlargement of a recording apparatus, and also results in uneasiness of high-speed carriage scanning due to larger weight applied to the carriage.
On the other hand, in the tank cartridge system, the above-mentioned problem is eliminated because the recording head is only mounted on the carriage. Since the recoding head is connected to the tank cartridge with the ink supply tube, however, a complicated mechanism becomes necessary resulting in uneasiness of miniaturization of a recording apparatus.
Besides, in the pit-in system, since ink is supplied from the main tank into the sub-tank and the volume of the sub-tank can be small, size and weight of the structure on the carriage become smaller than those in the head cartridge system, resulting in a simple configuration of the apparatus due to no more need of an ink supply tube.
However, in the pit-in system, since coupling portions between the main tank and the sub-tank (the ink inlet portion
122
a
and the joint portion
123
a
in the example shown in
FIG. 10
) are apart from each other during recording operation, foreign material such as paper powder and dust sticks and piles up onto the coupling portions during their usage for a long time. When the ink is supplied into the sub-tank from the main tank during their coupling, the piled-up foreign material is introduced into the coupling portions and may reach the recording head via the sub-tank. Once the foreign material reaches the recording head, discharge of the ink becomes unstable resulting in no discharge of the ink in the worst case.
Besides, sealing ability of the joint portion may decrease to introduce air into the coupling portions by piling up of the foreign material at the joint portion. Further, since the coupling portions are opened except when supplying ink, the ink filled in the coupling portions becomes dry to adhere as a solid to the interior of the coupling portions. Thus, as a result of introduction of air and adhesion of solid ink, flow resistance of ink in the coupling potions increases, and reliability of supplying ink decreases after all.
SUMMARY OF THE INVENTION
The object of the present invention is to provide an ink supply mechanism and an inkjet recording apparatus, wherein ink is supplied in high reliability still employing the pit-in system, which is able to supply ink by only a small and simple configuration.
Another object of the present invention is to provide an ink supply mechanism comprising a first ink tank for storing ink a joint portion connected to said first ink tank and a second ink tank disposed to be movable to said first ink tank and provided with a connection portion connected to said joint portion in order to make ink supply from said first ink tank possible, wherein said joint portion is movable between a connected position where said connection portion is connected thereto and a disconnected position where said connection portion is not connected thereto, and a cap member for sealing a region between said connection portion and said joint portion at both said connected position and said disconnected position is provided on said joint portion.
A still another object of the present invention is to provide an ink jet recoding apparatus for recording by means of discharging ink onto a record sheet from a recording head comprising a first ink tank provided in the recording apparatus for storing ink a joint portion connected to said first ink tank a second ink tank disposed to be movable against said first ink tank, being provided with a connection portion connected to said joint portion in order to make ink supply from said first ink tank possible and a carriage for reciprocating with the recording head and said second ink tank mounted thereon, wherein said joint portion is movable between a connected position where said connection portion is connected thereto and a disconnected position where said connection portion is not connected thereto, and a cap member for sealing a region between said connection portion and said joint portion at both said connected position and said disconnected position is p
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Vo Anh T. N.
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