JPH01130950A - Method for controlling multi-nozzle ink jet recording head - Google Patents

Abstract

PURPOSE:To markedly reduce the number of driving ICs as well as the actual mounting cost thereof by impressing the voltage equal to or greater than a threshold value at which ink is caused to foam to be discharged by the action of heat generated from a heating element only to an electrode selected from first and second electrodes, as well as controlling the foaming and discharging of ink by performing a time-division drive in synchronism with the feed speed of a member on which recording is conducted. CONSTITUTION:The voltage Vs to be impressed to a scanning electrode is zero or V1, and the voltage to be impressed to an information electrode V1 is V1 or V2. In this case, ink is caused to foam to be discharged when Vs equals 0 with V1 equaling V1. Since heating elements the impression voltages of which exceed the threshold value voltage Vr at a first time-division are r21 and r31, the foaming and discharging of ink is performed during the period designated by a reference character K, more specifically for 10mu sec. Similarily, the foaming and discharging of ink is perfomed by a heating element r12 when the next time- division is effected by the scanning electrode S2. The time-division drive is deigned to be conducted in synchronism with the feed speed of a member on which recording is effected. The scanning and information electrodes are designed to be driven by controlling a scanning drive IC 7 and an information drive IC 8 by means of a control section for controlling an entire recording apparatus.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method of controlling a recording head used in an inkjet recording device that records on a recording medium by flying an ink droplet, and particularly relates to a method of controlling a recording head of a fixed on-demand type The present invention relates to a method of controlling a nozzle inkjet recording head.

[Conventional technology]

In general, inkjet recording (liquid jet recording) generates negligible noise during recording, making it possible to perform high-speed recording.Furthermore, it is possible to record on so-called plain paper without the need for special processing such as fixing. Recently, there has been a lot of interest in the ability to record data.

Among them, for example, the inkjet recording method described in Japanese Patent Application Laid-Open No. 54-51837 and German Opening of Publication (DOLS) No. 2843084 uses thermal energy to act on ink to eject ink droplets. It has a different feature from other inkjet recording methods in that it obtains the driving force.

That is, the recording method disclosed in the above publication has the following characteristics. The ink that has been affected by thermal energy undergoes a state change accompanied by a sharp increase in volume, and the acting force based on this state change causes the ink to be ejected from the orifice at the tip of the recording head, creating flying ink droplets. is formed.

Then, recording is performed by the ink droplets adhering to the recording member.

In particular, the liquid jet recording method disclosed in DOLS No. 2843045 is not only very effectively applied to the so-called on-demand inkjet recording method, but also because the ink ejection section of the recording head is a full-line type. Since a high-density, multi-nozzle inkjet recording head can be easily implemented, high-resolution, high-quality images can be obtained at high speed.

[Problem that the invention seeks to solve]

Now, in order to take full advantage of the features of this high-density multi-nozzle inkjet recording head, we need a so-called fixed integrated full multi-head, which can record on A4 size paper without scanning the recording head. It is necessary to do so. 20, which is the width direction of the A4 paper now.
If you try to make an inkjet recording head on the same substrate that records at a density of 16 nozzles per 1 mm in an 8 mm width, the number of nozzles will be 208 x 16.
= 3,328 trees. Nozzles with a density of 16 nozzles per 1 mm are defect-free over a length of 208 mm.
Moreover, there is a problem in that a fairly sophisticated manufacturing technology is required to uniformly manufacture the film. Furthermore, in order to control 3,328 nozzles by an on-demand method, the same number of output stages as the number of drive circuits are required as the number of nozzles.

For example, if a driving IC chip with 64 outputs is used, a total of 52 chips are required. Moreover, 52 driving ICs
The connection between the electrode and the extraction electrode of each heating element for ejecting ink from each nozzle requires high-density and multiple wiring.
There was a problem in that the cost required for this implementation would be enormous.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to improve the yield in the manufacturing process and to control a fixed on-demand multi-nozzle inkjet recording head, which can be manufactured at low cost by reducing mounting costs and drive circuits. Our goal is to provide the following.

[Means for solving problems]

To achieve such an object, the present invention includes a plurality of first electrodes arranged parallel to each other at predetermined intervals on a substrate, and a plurality of first electrodes arranged parallel to each other at predetermined intervals and not perpendicular to the first electrodes. In a multi-nozzle inkjet recording head that includes a plurality of second electrodes that intersect at an angle and a heat generating element disposed approximately at the intersection of the first and second electrodes, a threshold value at which ink foams and is ejected due to heat generated by the heat generating element. Applying the above voltage only between a selected one of the plurality of first electrodes and a selected one of the plurality of second electrodes,
Bubble ejection of ink is controlled by time-division driving synchronized with the feed speed of the recording member.

[For production]

In the present invention, the number of driving ICs can be reduced by providing heating elements at the intersections of matrix electrode wires that intersect at non-perpendicular angles and performing time-division driving synchronized with the feeding speed of the recording member.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing an entire embodiment of the present invention. Here, 1 is a substrate, 2 is a scanning electrode, 3 is an information electrode, 4 is an orifice, 5 is an orifice plate, 6 is an ink tank, 7 is a scan drive IC, and 8 is an information drive IC. The ink droplets fly in the direction of arrow A.

FIG. 2 is a front view seen from the direction of arrow B shown in FIG. 1. Here, 1 is a substrate and 5 is an orifice plate. 31 to 332 are scanning electrodes indicated by reference numeral 2 in FIG.
I+04 is an information electrode designated by the reference numeral 3 in FIG. The scanning electrodes 81-S32 are arranged parallel to each other, and the information electrodes II-! +04 are also arranged parallel to each other. Scanning electrode Sl'''S32 and information electrode work,
~I+04 intersect at an angle θ (θ≠90 degrees), and orifices 01 to 033211, indicated by reference numeral 4 in FIG. 1, are arranged at or near the intersection. The reason why the angle θ between the scanning electrode and the information electrode is not set to 90 degrees is that time-division driving, which will be described later, cannot be performed when θ=90 degrees.

Now, 16
When manufacturing a full multi-nozzle inkjet recording head having nozzles of 1 mm/mm, for example, as shown in FIG. 2, if the scanning electrode is 32 mm and the information electrode is 104 mm, the orifice will be 3328 holes. If the angle θ between the scanning electrode and the information electrode is 86.4 degrees, then when the pitch P of each orifice is 1/16 mm, the pitch P2 is 1 mm. At this time, the scanning electrode extraction density is 1/mm
Therefore, the extraction density of the information electrode is 0.5 wood/mm.

FIG. 3 is a diagram showing an electrical equivalent circuit of FIGS. 1 and 2. Here, codes 81 to S32 and codes 11 to l
104 is the same as in FIG. In FIG. 3, r1 to r3328 are heating elements for making ink droplets fly, and correspond to orifices O2 to 03328, respectively.

FIG. 4 is a diagram showing the adhesion position of an arbitrary Nth row of ink droplets recorded on a recording member such as paper by flying ink droplets. Here, the dots shown in (1) to (32) are recorded in a time-division manner by one tree of information electrodes and 32 trees of scanning electrodes.

FIG. 5 is an enlarged view of the heating element section in this embodiment.

FIG. 5(A) is a view seen from the direction of the substrate surface. Figure 5 (
B) is a shoulder-to-shoulder 2 sectional view in Figure 5 (A).
Figure (C) is a sectional view taken along line B1-82 in Figure 5 (A). In FIG. 5, I is an information electrode and S is a scanning electrode. 9 is a heating element, and 10 is an insulating element. The information electrode (1) and the scanning electrode (S) were fabricated using 8t and had a film thickness of 5,000mm. The heating element was fabricated using Ta, and the film thickness was 1500 mm.

5in2 was used to fabricate the insulating element, and the film thickness was 1.5 μm ~
It is about 2.0 μm.

Next, a method for driving a multi-nozzle inkjet recording head according to the present invention will be explained. FIG. 6 is a simplified diagram for explaining the present invention. Figure 6 shows information electrodes ■, ~I
3 and scanning electrodes 81 to S3, respectively.

The heating elements marked now r21, r3+, r12, r2
A case will be described in which only 3 is driven in time division in the order of Sl, S2, and S3. The resistance value of each heating element is approximately 1
00Ω, and the threshold voltage at which the ink foams and is ejected is IOV with a pulse width of 10 μsec.

FIG. 7 is a timing diagram of the example shown in FIG. Here, the horizontal axis is time and the vertical axis is voltage.

VSI-VS3 and Vll-VI3 indicate voltages applied to scanning electrodes 31-S3 and information electrodes I+""I3, respectively. ■, □1~Vr33 is heating element r11
This shows the voltage applied between r33 and r33.

When VT is the threshold voltage at which the ink is foamed and ejected, and O or Vl is the voltage applied to the scanning electrode, the information electrode ■
The voltage applied to 1 to I3 is 1 or 2. And these voltages are determined by the formula 1v11≧IVTI>l
Vd+V21<IVTI must be satisfied. Now, assuming that the threshold voltage is v'T=10V, it can be set to, for example, v,=12V%V2=8V.

Time division driving of the heating element shown in FIG. 6 will be explained with reference to FIG. The voltage Vs applied to the scanning electrode is 0 or V
1, and the voltage applied to the information electrode V1 is Vl or V2, so in this case, ink is foamed and ejected when Vs=0 and V,=V.

In FIG. 7, the heating elements whose applied voltage exceeds the threshold voltage ■T in the first time division are r2+ and r3+, so the bubbling discharge of ink is performed for the period indicated by the symbol, specifically, for 10 μsec. It will be done. In the next time division using the scan electrode S2, the heating element r12 similarly performs bubbling and ejecting of ink. Note that time-division driving is performed in synchronization with the feeding speed of the recording member. The scanning electrode and information electrode are
The control unit that controls the entire printing apparatus controls the scanning drive IC 7.
and is driven by controlling the information driving IC 8.

In the above embodiment, the voltage applied to the scan electrode is set to 0 or Vls, and the voltage applied to the information electrode is set to 1 or V2.
However, the present invention is not limited to this, and any voltage setting that satisfies the conditions for foaming and ejecting ink may be used. In this example, there are 32 scanning electrodes and 104 information electrodes, so a total of 136 trees are mounted, and therefore the drive IC
It only takes 136 bits and the implementation cost is low. Furthermore, if the number of scanning electrodes and information electrodes is set to 64 and 52, respectively, with the same total number of nozzles (3328), the driving IC can be used for 116 bits, and further cost reduction is possible.

〔Effect of the invention〕

As explained above, in the present invention, matrix electrode wirings that intersect at non-perpendicular angles are provided on the substrate, and heating elements are provided near each of the intersections to perform time-division driving synchronized with the feeding speed of the recording member. I made it so that the drive I
This has the effect of significantly reducing C and implementation costs.

[Brief explanation of the drawing]

Fig. 1 is an overall perspective view of an embodiment of the present invention, Fig. 2 is a front view seen from arrow B in Fig. 1, Fig. 3 is an electrical equivalent circuit diagram of an embodiment of the invention, and Fig. 4 is Figure 5 is an enlarged view of the heating element section; Figure 6 is a schematic diagram for explaining the driving method to which the present invention is applied; Figure 7 is a diagram showing the attachment position of the flying ink droplets; Figure 7 is a schematic diagram to explain the driving method to which the present invention is applied. FIG. 3 is a timing diagram illustrating a driving method. DESCRIPTION OF SYMBOLS 1... Substrate, 2, I, Ir~I+04'' scanning electrode, 3, S, S, ~S32... Information electrode, 4.0
1-03328... Orifice, 5... Orifice plate, 6... Ink tank, 7... Scanning drive rc, 8... Information drive IC1 9, r1-r 3328... Heat generating element, 10 ...Insulating element. Figure 4: Al-A2 cross section B/-B Figure 6

Claims (1)

[Scope of Claims] A plurality of first electrodes arranged parallel to each other at predetermined intervals on a substrate, and a plurality of first electrodes arranged parallel to each other at predetermined intervals and intersecting the first electrodes at an angle that is not perpendicular to the first electrodes. In a multi-nozzle inkjet recording head comprising two electrodes and a heating element disposed approximately at the intersection of the first and second electrodes, a voltage above a threshold value at which ink is foamed and ejected due to the heat generated by the heating element is applied; The ink is applied only between a selected one of the plurality of first electrodes and a selected one of the plurality of second electrodes, and is driven in time division in synchronization with the feeding speed of the recording member. A method for controlling a multi-nozzle inkjet recording head, the method comprising controlling foam discharge.