JPS5838173A - Inkjet recording device - Google Patents

Abstract

PURPOSE:To raise the quality of printing by lessening influence of nozzle interval by a method in which row pitch is equalized with the sum of the whole multiple of dot pitch and its several portion for an ink jet recorder using a plate head with plural rows of nozzles. CONSTITUTION:In a head in plural nozzle 3 are provided in groups of 16 in two rows at the end of plate head, recording dots are staggeringly arranged in the first row 31-316 at the surface end and in the second row 3'1-3'16 on the back end, and printing is made by controlling the recording dots in such a way as to bury them by the timings of the nozzles of the first and second rows one dot apart. At this time, by adding 1/N of row number of lD to the whole multiple of the pitch lD of dots for recording the row pitch lN of the nozzle array, piezo- electric elements on surface and back sides are not driven concurrently. If the timings of the drive pulse in the first and second rows are supposed to be the relative speed VH of the head, the second row is driven at the time when lN/VH is biased from the head of the first row.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to inkjet recording, and particularly to an inkjet recording device that has a head with multiple rows of nozzles, has small shadows between the nozzles, has good printing quality, and has a fast printing speed. It is.

2. Description of the Related Art Conventionally, a circular inkjet recording apparatus using a plate-shaped head provided with multiple rows of nozzles has been used.

Figure 1C) shows an example of a multi-nozzle head. Inkjet recording is fast and resolution is O1! In order to meet the requirements, several nozzles are installed at the end of the plate-shaped head 10! 1 are provided in two rows, and the pressure for inkjet ejection is 1j corresponding to 3kK for each nozzle.
14k is provided, and the piezoelectric elements 21 to 2.k are provided on the outer n=plane and on the outer surface and on the outer surface, respectively. etc. were installed, of which 40
A 2hK Jl llb pulse is applied to eject I/R particles from the nozzle 3k. In such a multi-nozzle head, there are 16 nozzles, for example, as shown in Fig.
The first row 31 to 31-1 on the front edge and the second row 5t to 5'l on the back edge are mutually arranged in a staggered manner, and recording dots are placed every other dot as shown in Φ) in the same figure. By controlling the timing to fill the first and first row nozzles! Df
T! It can be made into highly printed tube material. In order to arrange such a large number of nozzles, as shown in FIG. In the piezoelectric element 2, 2-
is provided. In such a head, when the nozzles on both sides are driven simultaneously, they influence each other. In other words, conventionally, Silver I row, Fuki! The column pitch tN between columns is selected to be several times the recording dot pitch IDE), and each column is driven with the same phase. Therefore, when the nozzles 5k in the first row are driven so that the terminal speed is 5 n/, the pressure in the first row is 3i! When the opposite nozzles 3- are simultaneously driven, the particle velocity to the first row of nozzles 5 increases by about 20 to 50%. When the nozzle pan other than 3' of the first row is driven at the same time, the particle velocity at the nozzle 6 of the first row is 2.
It decreases by about 0%.

Velocity fluctuations such as ζO appear as misalignment of dots on the recording paper. Furthermore, the pressure chambers of the nozzles 5 in the first row are affected by the piezoelectric elements in the first row, which deteriorates the frequency characteristics of the nozzles 5. As described above, by arranging piezoelectric elements on the front and back sides and simultaneously driving Fi on the front and back sides with a conventional multi-nozzle head, the quality of small print is seriously degraded.

Object of the present invention To provide an inkjet recording device in which a plurality of nozzles are arranged in at least two rows and when driving piezoelectric elements provided on the front and back of a head, high printing quality is maintained by preventing mutual influence. That's true.

In order to achieve the above object, the inkjet recording device of the present invention has a plurality of nozzles arranged in at least two rows, and a pressure chamber for inkjet ejection corresponding to each nozzle is provided inside,
In an inkjet recording apparatus having a multi-nozzle head in which piezoelectric elements for pressure driving are arranged on the outside or surface thereof, and a drive circuit for supplying a drive voltage to the piezoelectric elements, the row pitch of the plurality of nozzle rows is fixed. N is an integral multiple of the dot pitch ID to be recorded on the inkjet, plus 1/a predetermined number of #ID, and the basic driving frequency of the drive circuit is set to the predetermined number of times the maximum dot repetition frequency. , the fact that the piezoelectric elements are sequentially shifted and applied to the piezoelectric element array is defined as % mold.

The present invention will be described in detail below with reference to examples.

FIG. 113 is an explanatory diagram showing the configuration of an embodiment of the present invention.

In the present invention, the row pitch number N of the nozzle array is added to an integer multiple of the dot pitch jD0 to be recorded by 1/N of the number of rows ID, so that the piezoelectric confectionery on the front and back sides are not driven at the same time.

As shown in the figure, the nozzles are arranged in D16 x 2 rows, as described above in Figure #I2 (1), and the resolution is 1°.
When using Rid/Custom, the minimum dot pitch to record is 10
It is 0 μ father-in-law.

Therefore, 1w= (n +i) In (nti
integer) (1), N-2v 1D=10
0 finyorutM-x(n+-H) @1oo (a
n (2) Therefore, the value of column pitch 1M is 150μ,
250μI! , 550μ town 450μfly ssOμ
A 650μ wing, etc., would be appropriate.

here,! If you set summer = 550μ weight, it will be in the I column.

The timing of the drive pulse for the second row is Ik4 diagram (a), Φ
), the relative speed of the head It VIE is 1
The column (2) is driven at the point when it is ly positions away from the beginning of the column, and the two are not synchronized.

Based on the above principle, a driving clock may be supplied to the piezoelectric element so that a plurality of nozzle arrays including 6a are not always driven simultaneously.

JliS diagrams C) to (C) illustrate the supply method for each nozzle row in this case. In other words, the same figure (a
), the basic clock fc is converted into a dot frequency fD.
Repeatedly by oN times (fc=Nfp), for one nozzle row, as shown in Fig. .2.・
) is used as a column clock, and particle formation is performed according to the print signal. ! For column ii+1, NJ+(
5rs) ml lj is used as a column block. In this way, as is clear from the figure, no rows in the multi-nozzle helad are driven at the same time, so they do not affect each other. Generally, the number of nozzle rows is 2 to 4, so even if the dot frequency fD is 10 KH2, the necessary basic clock frequency is about 20 to 40 KHz, which poses no practical problem. 6(a) to (C) show the basic clock and the first clock when there are two nozzle rows (N=2). Second
Shows the relationship of column clocks for columns. Diagrams 7 (a) to (C) are shown as tPiJ when there are four nozzle rows (N=4).

In the above example, the simultaneous side IIJJ of the nozzles in each nozzle row is completely eliminated and a good one is obtained, but the simultaneous side of the i-nozzles that has the greatest influence! It is conceivable that there are cases in which the purpose can be almost achieved just by eliminating #.

In the multi-nozzle head described above, the nozzle that has the greatest effect on the simultaneous side mo- is the one in which the pressure chamber and the piezoelectric element are located on the front and back sides, as shown in FIG. 2(C). This relationship is the same whether the head shown in Stripe 1 has two or four nozzle rows. Therefore, it is avoided to perform only the simultaneous side of the columns that have such a front-back relationship.

In this case, even if the nozzle row is N, the row pitch IN is equal to the dot pitch AD! Add 1/2 of ID to L times.

That is, it is set as 4N=(n+1)ID (n is the frequency) (3).

In this case, the nozzle rows ta to d of the multi-nozzle head are shown in Fig. 8(a), Φ) as the basic clock and the first row to g.
It shows the timing of the drive clock of the d column.
Figure 9 shows the nozzle arrangement, one row (5, 1, 5 peaks...)
, column b (5bt, 5bx+...), column C (Lx.

5 peaks...) and d rows (54s, 34z, ..."), and FIG. 10 shows piezoelectric elements 1 corresponding to Oa rows to d rows.
Row (2-1゜2 mountains...s, row b (2bx+2bsr...
・S, C column (2@1.2dl ”...λd column (2dx*
2as+...ri are arranged. As shown in Figure 10, the piezoelectric elements in the 1st and d columns, and the b and C columns, face each other in a front-back relationship to avoid simultaneous driving of both, thereby reducing their mutual influence. It gets thicker.

Therefore, as shown in FIG. 8 Φ), the 8th column and the C column are driven simultaneously, but i& is also out of phase with the 6th column, which has a large influence. The same applies to the cases of the A-th column and the C-th column. In this way, a practically sufficient effect can be obtained with almost no speed change as seen in conventional heads.

FIG. 11 is a detailed explanatory diagram of the present invention for realizing the above-mentioned principle 1. A case of simple rounding with two columns is illustrated.

The basic clock uses the encoder output of the printer, 2ゎ2, nib, /? 11, 1, 1 and 1 are also allocated to the column clock input for the print signal, and the signal generator 121 s 12
g and sequentially supplies a drive clock to each nozzle column via a drive amplifier.

As explained above, according to the present invention, the row pitch of the nozzle rows can be reduced without changing the structure of the conventional multi-nozzle head.
By setting N to be the dot pitch ID (a number of times DJ plus 1/a predetermined number of jD), simultaneous driving is performed at the threshold of the piezoelectric elements that influence each other most by shifting the driving clocks. This allows for inkjet recording with high printing quality and fast printing speed.
can be realized.

[Brief explanation of the drawing]

Fig. 1 (Jl), Φ), Fig. 2 (a) to (C) are explanatory diagrams of a conventional multi-nozzle head, Fig. 5 is an explanatory diagram of the nozzle configuration of the present invention, and Fig. 4 (a), Φ ) ~ Figure 7 (a), Φ
) is an explanatory diagram of the driving method of the embodiment of the present invention, W, and 8 (a
), (b) - Figure 10 line I5! of the driving method of another embodiment of the present invention! The clear diagram and rattan 11 diagram are detailed explanatory diagrams of the present invention.
, in the figure. 1 is a plate-shaped head, 21~2□2 + 2ml~2ds+
2m2~2o are piezoelectric elements, 51~5a+5'1~5
'. , 511~6-1゜61~5d Mushroom is nozzle, 4+
4' is a pressure chamber, 11 is a multiplexer, 121y 1
2 indicates the signal generator. %ken Applicant Fujitsu Limited Sub-Agent Patent Attorney 1) Yoshishige Saka Figure 1 Figure 3 Figure 4 Figure 5 Figure 6 fc = 2f. 2468 Figure 7 Figure 8 Figure 1 Second row chronograph

Claims (2)

[Claims] (1) Arranging multiple nozzles in at least two rows, and providing internal pressure for inkjet ejection corresponding to each nozzle;
In an inkjet recording apparatus having a multi-nozzle head in which piezoelectric elements for pressure jIKWIJ are arranged on the outer surface or long surface, and a drive circuit that supplies a driving voltage to the piezoelectric elements, the plurality of nozzle rows Q row pitch no. Dot pitch JnQ that should be recorded on inkjet! i number times + lt- for a predetermined number of wrinkles D, and set the basic sliding wave number of the output of the drive circuit to the predetermined number times the moth height dot repetition frequency, and An inkjet recording device characterized in that the inkjet recording device is configured to sequentially shift the inkjet recording device. (The inkjet recording apparatus according to claim 1, wherein the predetermined number is the number N of rows of multiple nozzles. (2) The inkjet recording apparatus according to claim 8, wherein the predetermined number is 2 regardless of the number N of columns.