Incremental printing of symbolic information – Ink jet – Ejector mechanism
Reexamination Certificate
2001-07-09
2003-05-06
Hallacher, Craig (Department: 2853)
Incremental printing of symbolic information
Ink jet
Ejector mechanism
C347S065000
Reexamination Certificate
active
06557982
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink jet recording method and an ink jet recording apparatus performing a recording operation by discharging a liquid such as an ink.
2. Related Background Art
For an ink discharging method of a conventional ink jet recording system in use today, there exists a method of discharging an ink droplet utilizing an electro thermal converting element (heater) as a discharge energy element and a method of discharging an ink droplet utilizing a piezoelectric (piezo) element, either of which is capable of controlling the discharge of the ink droplet by an electric signal. For example, one feature of the ink droplet discharge method using the electro thermal converting element is that, by giving the electric signal to the electro thermal converting element, the ink in the vicinity of the electro thermal converting element is instantaneously boiled, and by an abrupt growth of a bubble produced by a phase change of the ink on that occasion, the ink droplet is discharged at high speed. On the other hand, a feature of the discharge method of the ink droplet utilizing the piezoelectric element is that, by giving the electric signal to the piezoelectric element, the piezoelectric element is displaced and, by a pressure caused at the displacement time, the ink droplet is discharged. The former method has the advantages that it does not require undue space for the discharge energy generation element, the constitution of an ink jet recording head is simple, and an integration of nozzles is easy. On the other hand, this method has disadvantages such as a volume fluctuation of a flying ink droplet caused by a heat storage in the ink jet recording head of heat generated by the electro thermal converting element, and an influence exerted on the electro thermal converting element by a cavitation due to a bubble extinction.
In the ink jet recording head where a plurality of energy generation elements are formed, energy is not normally applied simultaneously to all of a plurality of energy generation elements. As a practical matter, when the electric signal is given simultaneously to the eletro thermal converting elements, because the electric current simultaneously flowing is increased, an electric power source capable of supplying a large electric current is required and the efficiency becomes poor. Further, because a voltage drop occurs in the wiring between the power source and the electro thermal converting element, the efficiency is lowered. Hence, a plurality of electro thermal converting elements are driven by being subjected to a time division.
In the ink jet recording head of a so-called edge shooter type ink does not discharge almost vertically from a discharge port facing the electro thermal converting element. Instead, the ink discharges in the direction having a certain angle (acute angle) including 0°. Because the discharge ports are arranged in a straight line, the displacement position of dots has often deviated when the time division driving was performed. For this reason, a row of discharge ports was arranged obliquely at a certain angle so that the displacement dots were made straight in a line. However, when a block driving was performed, because another block performing the discharge subsequently to the block which has finished the discharge was in the vicinity, a displacement deviation of dots was easy to observe visually.
On the other hand, in the ink jet recording head of a so-called side shooter type which discharges almost vertically from the discharge port facing the electro thermal converting element, the position of electro thermal converting elements
414
arranged on both sides of an ink supply port
415
and the position of the discharge ports are deviated only by the displacement deviation produced when the time division driving was performed as shown in
FIG. 19
so that the displacement dots were made into a line. For example, in the ink jet recording head as shown in
FIG. 19
, and also as shown in Table 1 and Table 2, the electro thermal converting element
414
was allowed to carry a deviation of the maximum 18 &mgr;m, that is, equivalent to 1200 DPI as a deviation in the X direction.
TABLE 1
Deviation in X
Segment
direction
0
0
2
1
4
7
6
8.5
8
14.5
10
15.5
12
2.5
14
3.5
16
9.5
18
11
20
17
22
18
24
4.5
26
6
28
12
30
13.5
(Even number segments are a repetition of the above described sequence in the following segments.)
TABLE 2
Deviation in X
Segment
direction
1
0
3
1
5
7
7
8.5
9
14.5
11
15.5
13
2.5
15
3.5
17
9.5
19
11
21
17
23
18
25
4.5
27
6
29
12
31
13.5
(Odd number segments are a repetition of the above described sequence in the following segments.)
However, in the conventional ink jet recording head of the side shooter type, because the position of the electro thermal converting element is deviated, in the discharge port where the distance from the ink supply port for supplying the ink to the inside of the nozzle to the electro thermal converting element is relatively long, the time for refilling (refill) after discharging the ink is required much more and thus a high speed response has been degraded. By allowing the discharge to be performed at the timing which is not in time for refilling, a discharge defect was caused or a discharge amount was lowered.
Also, the longer the distance from the ink supply port to the electro thermal converting element, the greater the inertial resistance in the initial stage of energization of the electro thermal converting element and bubbling at the ink supply port side, and therefore a bubbling tends to grow at the discharge port side. For this reason, the ink discharge amount becomes larger than the amount discharged from the discharge port where the distance from the ink supply port to the electro thermal converting element is short and tends to be uneven, and the problem often arises that, because a discharge speed becomes relatively high, the displacement deviation cannot be accurately corrected.
Further, because a wiring resistance between the electro thermal converting element and a driving element depends on the distance from the ink supply port to the electro thermal converting element, the wiring resistance does not become uniform and an irregularity is caused to the energy required until the bubbling arises between the electro thermal converting elements. Thus, there was often the case where the energy is supplied enough for the electro thermal converting element which requires the energy most and a durability of the electro thermal converting element is lowered.
Further, in the ink jet recording head, due to evaporation of the ink from the discharge port, when the discharge starts from a non-recording state, there occurs a phenomenon referred to as a viscous plug property which leads to the discharge defect such as the non-discharge, a diminished dot where the discharge amount becomes small and the like. The viscous plug property tends to become worse for the discharge port having a long distance from the ink supply port to the electro thermal converting element as it is hard to get an ink supply when the evaporation of the ink further advances and, in particular, the smaller the liquid droplet became, the more marked influence it received. Further, particularly for the discharge port which is separated from the adjacent discharge port by deviating the position of the electro thermal converting element and the discharge port for correcting the displacement deviation, a control effect of the evaporation by the evaporation atmosphere from the discharge port was lowered, and the viscous plug property was easy to occur. In this connection, the ink evaporates from the discharge port and the density of the ink in the discharge port is raised with the result that the density of the discharged displacement dot sometimes becomes high. In the head of the side shooter type where the disposed position of the discharge port is deviated as described above and the interval between the ink supply port and the electro thermal converting eleme
Kawatoko Norihiro
Mizutani Michinari
Murakami Shuichi
Tajika Hiroshi
Canon Kabushiki Kaisha
Fitzpartick, Cella, Harper & Scinto
Hallacher Craig
Stephens Juanita
LandOfFree
Ink jet recording method and apparatus for driving... 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 method and apparatus for driving..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ink jet recording method and apparatus for driving... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3053115