Incremental printing of symbolic information – Ink jet – Fluid or fluid source handling means
Reexamination Certificate
2002-08-20
2004-08-31
Vo, Anh T. N. (Department: 2861)
Incremental printing of symbolic information
Ink jet
Fluid or fluid source handling means
C347S086000, C347S092000
Reexamination Certificate
active
06783220
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink-jet recording apparatus, and more particularly to an ink cartridge (hereinafter also referred to as an ink tank) for storing ink to be supplied to an ink-jet head, a recording unit which integrally includes the ink cartridge and the ink-jet head, which are removably connected with each other, and the ink-jet recording apparatus on which the recording unit can be removably mounted. In the following description, the term “record” includes a meaning of printing characters, images or the like on cloth, paper, plastic sheet, or the like.
2. Description of Related Art
Several types of recording apparatuses on which a recording head of one's own method such as: wire-dot method; thermal recording method; thermal-transfer method; and ink-jet method, is mounted, and which record characters, images or the like on a recording medium such as a paper, have been proposed. Among these methods, the ink-jet recording method is one of non-impact methods and includes the steps of ejecting ink droplets and depositing these ink droplets on the recording medium. Thereby, a recording apparatus using a recording unit of this method can perform recording with high-speed and high-density. As a result, they have been provided as printers as output terminals of an information processing systems e.g., copying machines, facsimiles, printing machines, word processors, work stations, or the like; or they have been provided as handy- or portable-printers of personal computers, host computers, optical disc- or video-equipment or the like.
In the case of that the ink-jet recording apparatus is used in these system, the ink-jet recording apparatus is constructed so as to accord with respective particular function and condition for use of these systems. To miniaturize a size of the information processing system is one of main current demand. Accordingly, the recording unit and the main body of the ink-jet recording apparatus using this unit are demanded to be miniaturized.
While such a miniaturizing is realized on an actual apparatus base, however, it is need for the recording unit or the like to maintain performance which have been known usually in the unit or to have further performance in order to answer these demands, there have been proposed various recording units and various recording apparatuses in which this unit is mounted.
One of the embodiments is explained first with reference to FIG.
1
.
In this figure, an ink-jet unit includes an ink-jet head
102
and an ink cartridge
101
as a reservoir for storing the fluid such as ink, which are removably connected to each other. The ink-jet unit is removably mounted on a carriage
121
. Also the carriage
121
is movably attached to a guide shaft and a lead screw which are supported by a main frame
122
of the ink-jet recording apparatus
120
.
It is noted that the ink-jet unit is not limited to the structure described above. That is, for example, there is an ink-jet unit having an ink cartridge integrally connected with the ink-jet head. In the case of using the former type of ink-jet head, the ink cartridge is of an interchangeable type while the ink-jet head is fixed or removably mounted on the carriage.
In the case that the recording head (ink-jet head) and the ink cartridge are mounted on the carriage as described above, it is necessary to provide the ink cartridge with a mechanism of generating a negative pressure. In the description below, in general, the term “a negative pressure” is defined as a state of that a water head pressure of the ink is kept at a value lower than that of the atmospheric pressure enough to stop a leakage of ink from nozzles of the recording head. As a negative pressure generating mechanism provided in the ink cartridge, a porous member as an ink absorbing member is used which generates a capillary force of the porous member. In the case of using the porous member, as disclosed in the documents such as Japanese Patent Application Laying-Open No. 2-187364, the ink cartridge takes the construction of that the ink inlet portion of the recording head is press-inserted into the ink absorber of the ink cartridge for increasing an efficiency of using the ink, that is, for reducing the rest amount of the ink in the ink absorber.
According to the construction described above, the capillary force of the porous member can be locally increased by deforming the ink absorber at a part thereof around the ink-inlet portion and thereby the ink is induced to the neighborhood of the ink-inlet portion and ink supply is promoted so that the rest amount of ink in the ink absorber is decreased.
In the case of the removable type recording unit (ink-jet unit), there is a possibility that the user will change the empty ink cartridge with new one. Also, there is another possibility of changing the recording head with new one or filling up the empty ink cartridge with ink to use it again. Furthermore, there is a possibility of that the user will separate them oftener than he or she have to do. Therefore, it is difficult to predict the situation on which the recording head or the ink cartridge is detached and is mounted. At the stage of the separation or connection between them, therefore, the amount of air can be allowed to enter the ink cartridge and prevents an ink route from being formed between the recording head and the ink cartridge.
The removable type recording unit as disclosed in the Japanese Patent Application Laying-Open No. 2-187364, especially in the case of that the ink inlet portion of the recording head is press-inserted into the ink absorber for using the ink efficiently, has the following problems. That is, the present inventors find that the recording head is difficult to receive the ink from the ink cartridge generally in the case of after connecting the ink cartridge with the recording head, again before the ink cartridge is used up.
In this situation, the ink flow to the recording head cannot be often recovered by an ejection recovery operation with the step of sucking ink out of ejection port of the recording head and thus it is difficult to consume the ink completely. The present inventors make clear that the largest cause for such trouble in the situation described above is as follows.
FIGS. 2A and 2B
illustrate one of the embodiments of the ink-jet recording apparatus for explaining such cause.
FIG. 2A
shows connected state of a recording head
2
with an ink cartridge
3
, and
FIG. 2B
shows detached state of the former from the latter.
As shown in the figures, an ink-jet unit
4
is constituted by removably connecting the recording head
2
with the ink cartridge
3
by means of a pair of parallel connecting claws (not shown).
At the connection, the ink-inlet portion
40
of the recording head
2
is inserted into a cylindrical connecting portion
39
which is used as an ink supply portion. The ink path
39
can be isolated from the external atmosphere by means of the O-ring
35
which seals around the connected portion and which is made of ethylene propylene rubber or the like.
The porous member (i.e., an ink absorber such as a sponge material)
37
occupies the inner side of the ink cartridge
3
so as to store the ink to be supplied to the recording head
2
. That is, the porous member has an ability of holding the ink.
Therefore, the density of the porous member is adjusted and a water-head pressure of the recording head
2
is kept to be and lower than that of the atmospheric pressure so as to avoid the ink leakage.
In the ink-jet recording head having the structure described above, a part of the ink absorber adjacent to the connecting portion
39
is directly subjected to the external atmosphere when the recording head
2
and the ink cartridge
3
are in the removed condition. In this case, while the deformed ink absorber
37
is coming back its original shape, the ink absorber
37
induces air so that the part
38
of the ink absorber
37
adjacent to the connecting portion
39
of the ink cartridge
3
can be filled
Takenouchi Masanori
Tsukuda Keiichiro
Ujita Toshihiko
LandOfFree
Ink jet recording apparatus using recording unit with ink... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ink jet recording apparatus using recording unit with ink..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ink jet recording apparatus using recording unit with ink... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3303872