Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
1996-04-16
2001-01-23
Barlow, John (Department: 2853)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
Reexamination Certificate
active
06176565
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an improved cleaning member for removing foreign matters deposited at the discharging outlet face of an ink jet head for performing recording by discharging ink and to an ink jet apparatus provided with said cleaning member. The cleaning member is constituted by a material comprising a polyurethane prepolymer, a bifunctional curing agent, and a water repellancy-adding material. The cleaning member is surpassing known cleaning members especially in cleaning durability.
BACKGROUND OF THE INVENTION
According to an ink jet system described in U.S. Pat. No. 4,723,129 or U.S. Pat. No. 4,740,796, recording with a high density and a high definition and of a high quality can be conducted at a high speed. According to this ink jet system, color recording can be attained. The recording head in this ink jet system can be prepared utilizing the techniques in the field of semiconductor. The apparatus can be, therefore, relatively easily miniaturized.
In such an ink jet system, an ink jet head provided with a plurality of ink discharging outlets of an extremely minute size is used. Upon conducting recording using such ink jet head, ink is discharged through the ink discharging outlets upon the application of a recording signal to spatter and deposit on a record medium, thereby achieving the recording.
The conventional ink jet head is either of the so-called continuous type in which ink is continuously discharged such that the ink is selectively deposited on a record medium or of the so-called on-demand type in which only droplets of ink necessary for recording are intermittently discharged to a record medium.
As for the on-demand type ink jet head, there are typically known a full-line type ink jet head in which a plurality of ink discharging outlets are arranged to correspond to the width of a record medium, and a serial scanning type ink jet head in which recording is conducted by moving the head in ralation to a record medium.
Incidentally, as for an ink jet apparatus in which such an ink jet head as above described, there are still such shortcomings to be solved as will be described in the following. That is, in the case of conducting recording by using an ink jet head provided with a plurality of discharging outlets of a minute size through which ink is discharged in fine-grained form, dirts or dusts present in the recording apparatus, paper powder resulted from a record medium, or droplets of ink are likely to deposit on a discharging outlet face
1
a
provided with discharging outlets
1
b
or at positions in the vicinity of the discharging outlets as shown in FIGS.
7
(
a
) and
7
(
b
). These deposits often hinder the direction of flight of droplets discharged from the discharging outlets, or they are sometimes dried and solidified to plug up some of the discharging outlets such that ink cannot be not discharged through those discharging outlets.
In order to eliminate these problems, there has been proposed a so-called blade cleaning method wherein the discharging outlet face deposited with such foreign matters is brushed by means of a blade made of an elastic material such as polyurethane rubber, polyester-urethane rubber, hydrogenated nitrile rubber, or silicone rubber to remove the foreign matters from the discharging outlet face.
Now, there is an increasing demand not only for a mono-color ink jet recording apparatus but also for a multi-color ink jet recording apparatus provided with four individual ink jet heads respectively capable of discharging ink of a different color of yellow, magenta, cyanogen, or black. In the case of the recording in which color tone is varied using these four inks of a different color, it is necessary to discharge a plurality of different inks as for a dot and because of this, rather strict discharging accuracy is required than that in the case of conducting recording using a momo-color ink jet recording apparatus. Therefore, it is necessary for the discharging outlet face of each of the recording heads, which discharge individual ink of a different color, to be maintained in a cleaned state so that stable ink discharging is always provided. For this purpose, the cleaning reliability by means of the blade cleaning is necessary to be always secured.
As for the cleaning blade used in such full-color recording apparatus, there are known a configuration in which an independent cleaning blade is installed in each of the recording heads and another configuration in which a common cleaning blade is installed in the apparatus so that each of the recording heads can be cleaned by the common cleaning blade. In the viewpoint of reducing the area occupied by the cleaning blade in the recording apparatus as much as possible in order to miniaturize the size of the recording apparatus, the manner of cleaning each of the four recording heads by a common cleaning blade is the most desirable. However, in this cleaning manner of cleaning the individual recording heads continuously discharging different inks by a common cleaning blade, there is a tendency that those different inks are mixed on the cleaning blade to result in causing the formation of an image defective in color tone.
In order to eliminate this problem, there has been proposed a manner in which the cleaning is conducted successively from the recording head of discharging ink of relatively light color to the recording head of discharging ink of dark color to prevent occurrence of ink admixture at the recording head of discharging light color ink.
Another manner has been proposed in which an ink absorbent is disposed between each adjacent color ink jet heads, after one of the heads has been cleaned by a cleaning blade, ink deposited on the cleaning blade is removed by the ink absorbent, wherein the next head can be cleaned by the cleaning blade without suffering from any negative influence from the previously cleaned head.
In the following, description will be made of the latter cleaning manner with reference to FIG.
1
. As apparent in
FIG. 1
, a main scanning carriage
2
provided with ink jet heads
2
is designed to travel on a main scanning rail
3
. In the non-recording zone separate from the recording zone in the apparatus, a cleaning blade
4
is arranged such that it contacts with a discharging outlet face
1
a
of the ink jet head
1
. Reference numeral
5
indicates a holder which serves to fix the cleaning blade
4
. By moving the main scanning carriage
2
in the direction expressed by mark A, the discharging outlet face
1
a
is rubbed by the cleaning blade
4
arranged in the non-recording zone, whereby deposits X such as ink droplets, paper powder, dusts, and the like which are deposited on the discharging outlet face
1
a
are removed by the action of an edge of the cleaning blade
4
. The ink deposited on the cleaning blade
4
is removed by an ink absorbent
6
which is disposed between each adjacent ink jet heads. Thus, the cleaning blade
4
in cleaned state comes to the result of serving to clean the next ink jet head. According to this manner, all the individual recording heads of discharging ink of a different color can desirably be cleaned by the cleaning blade in cleaned state without causing admixture among the different inks. In this cleaning manner, the cleaning blade is rubbed with the discharging outlet face as many times as the number of the ink jet heads in one cleaning operation cycle and therefore, the frequency of the cleaning blade to be rubbed is greater than that in other cleaning manner.
Independently, in recent years, research and development have been made not only of high speed recording but also of the manner which enables high-volume recording by a single recording apparatus comprising an ink jet recording head of the head-exchangeable type in such viewpoints as will be described in the following.
For instance, in the case of the high speed ink jet recording apparatus, since the amount of ink to be discharged in terms of unit hour unavoidable becomes great, ink becomes more liable to deposit on the dischar
Arai Atsushi
Kuramochi Kiyoshi
Tajika Hiroshi
Uchida Haruo
Watabe Masahiro
Barlow John
Brooke Michael
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
LandOfFree
Cleaning member for ink jet head and ink jet apparatus... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cleaning member for ink jet head and ink jet apparatus..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cleaning member for ink jet head and ink jet apparatus... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2444879