JP2003159796A - Pattern forming method by ink jet system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pattern forming method by an ink jet system suppressing and uniforming the amount of droplet discharged from a piezo type driving head. <P>SOLUTION: When a control circuit 100 generates various kinds of control signals, C1, C2, RTC, FTC, a pulse generation circuit 200 generates a driving pulse P based on these control signals and supplies them to a piezo driving type head 300. The driving pulse P contains a main pulse and a sub pulse. The control circuit 100 supplies each control signal to each of head control units U1-Un based on each set data. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern forming method by an ink jet system capable of forming a highly precise pattern.

[0002]

2. Description of the Related Art In recent years, formation of high-definition patterns using an ink jet recording apparatus has been required mainly for the purpose of cost reduction. For example, a color filter used in a color liquid crystal display device has been conventionally manufactured by, for example, a pigment dispersion method or the like, but it is necessary to repeat the photolithography process a plurality of times.
There was a cost problem. If such a color filter can be manufactured by an inkjet method, it will lead to a significant cost reduction.

However, in order to perform such a high-definition pattern by the ink jet method, it is necessary to control the ink ejection amount from the head of the ink jet recording apparatus with a small amount and with high accuracy. That is, in order to form a line having an extremely thin line width such as a colored layer forming a color filter, it is preferable that the amount of ink in each droplet is small. Further, the amount of ink ejected from each piezo-type drive head is usually slightly different depending on the piezo-type drive head, if no control is performed. As described above, when pattern formation is performed by using a head having a different ejection amount by a piezo type driving head, unevenness occurs in a pattern such as a color filter, which reduces the yield of products. Therefore, it is preferable that even if the amount of ink ejected from the piezo drive head is small, control is performed so as to minimize the variation in the ejection amount between the piezo drive heads.

However, it has been extremely difficult to reduce the amount of ink ejected from the piezo type driving head and make the ejection amount uniform by the conventional ink jet type pattern forming method.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a pattern by an ink jet system that can make the amount of liquid droplets ejected from a piezo type drive head uniform and small. A forming method is provided.

[0006]

In order to achieve the above object, the present invention uses a piezo drive type head as set forth in claim 1, and a main pulse and a main pulse are applied to the piezo drive type head. In a pattern forming method by an inkjet method using a double pulse method in which a sub-pulse applied at a predetermined interval from the above is applied to eject a droplet, by changing the waveform of the main pulse, an appropriate amount of the liquid ejected from the head is obtained. There is provided a pattern forming method characterized by controlling

In the present invention, the amount of liquid droplets ejected from the head is reduced by the double pulse method, and the waveform of the main pulse when the double pulse method is used is changed to control the amount of liquid droplets. Therefore, the amount of ink ejected from each piezo drive head can be made uniform.

In the invention described in claim 1, if the main pulse and the sub-pulse are positive-polarity pulses with the drive voltage intensity in the normal state of the piezo drive type head as a reference voltage intensity, As described in Item 2, it is preferable that the change in the waveform of the main pulse is a change in the rise time of the main pulse. On the other hand, if the main pulse and the sub pulse are negative pulses with the drive voltage intensity in the normal state of the piezo drive type head as the reference voltage intensity, the waveform of the main pulse as described in claim 3. Is preferably a change in the fall time of the main pulse. According to the invention described in claim 2 or 3, the droplet amount is controlled by changing the ink suction state.

Further, in the invention described in claim 1, if the main pulse and the sub-pulse are positive-polarity pulses with the drive voltage intensity in the normal state of the piezo drive type head as a reference voltage intensity. As described in claim 4, it is preferable that the change of the waveform of the main pulse is the change of the falling time of the main pulse. On the other hand, if the main pulse and the sub-pulse are negative pulses with the drive voltage intensity in the normal state of the piezo drive type head as the reference voltage intensity, the waveform of the main pulse as described in claim 5. Is preferably a rise time change of the main pulse. According to the invention described in claim 4 or 5, the droplet amount is controlled by changing the ejection state of the ink.

Further, as described in claim 6, a change in the waveform of the main pulse is a change in the maximum voltage intensity of the main pulse. In addition, a change in the waveform of the main pulse is described in claim 7. However, it is preferable that the change is the pulse width of the main pulse, and these may be used in combination. By changing the waveform of the main pulse by these methods, it is possible to change the amount of ink droplets from the piezo-type drive head, and control the ink ejection amount from each piezo-type drive head to make it uniform. It becomes possible to do. Furthermore, in the pattern forming method by the inkjet method according to any one of claims 1 to 7, in addition to the change of the waveform of the main pulse, the change of the waveform of the sub-pulse is controlled. May be. As a result, it is possible to control the droplet amount from the head more accurately, and as a result, it is possible to make the droplet ejection amount from each head more uniform.

According to a ninth aspect of the present invention, a piezo drive type head is used, and a main pulse and a sub pulse added at a predetermined interval from the main pulse are applied to the piezo drive type head. In a pattern forming method by an inkjet method using a double pulse method for ejecting liquid droplets, there is provided a pattern forming method characterized in that an appropriate amount of liquid ejected from the head is controlled by changing a waveform of the sub-pulse. .

In the present invention, the double pulse method is used, and in this case, the amount of liquid droplets from each piezo type driving head is changed by changing the waveform of the sub pulse. By changing the waveform of the sub-pulse, it is possible to control the amount of droplets from each piezoelectric drive head to be uniform.

In the invention described in claim 9,
11. If the main pulse and the sub-pulse are positive-polarity pulses with the drive voltage intensity in the normal state of the piezo drive type head as a reference voltage intensity.
It is preferable that the change in the waveform of the sub-pulse is a change in the rise time of the sub-pulse, as described in (1).
On the other hand, if the main pulse and the sub pulse are negative pulses with the drive voltage intensity in the normal state of the piezo drive type head as the reference voltage intensity, the waveform of the sub pulse as described in claim 11. The change is preferably a change in the fall time of the sub-pulse. According to the tenth and eleventh aspects of the invention, the amount of liquid droplets is controlled in the process of once sucking the ejected ink.

Further, as described in claim 12, the change of the waveform of the sub-pulse is the change of the maximum voltage intensity of the sub-pulse, and as described in claim 13, the change of the waveform of the sub-pulse is the sub-pulse. It is preferable that the change is made by changing the pulse width of the waveform, and further by changing the combination of these waveforms.

By changing the waveform of the sub-pulse by these methods, it becomes possible to change the amount of ink droplets from the piezo drive head, and control the amount of ink ejected from each piezo drive head. Is possible. In addition, the amount of droplets ejected from the head may be controlled by changing the interval between the main pulse and the sub pulse as described in claim 14. It can be said that this is a preferable method because it is possible to greatly change the amount of droplets by changing various factors in combination as described above, and the range of control is widened.

Further, in the present invention, as described in claim 15, a piezo drive type head is used, and a main pulse and a sub-pulse added at a predetermined interval from the main pulse are applied to the piezo drive type head. In a pattern forming method by an inkjet method using a double pulse method for ejecting liquid droplets, a suitable amount of liquid ejected from the head is controlled by changing an interval between the main pulse and the sub pulse. A method for forming a pattern is provided. In addition to the above-described change of the waveform of the main pulse and the change of the waveform of the sub-pulse, it is possible to control the amount of the droplet by changing the interval between the main pulse and the sub-pulse. .

Further, in the present invention, as described in claim 16, there are a plurality of the piezo drive type heads, and each piezo drive is performed so that an appropriate amount of liquid ejected between the piezo drive type heads is uniform. It is preferable to adjust at least one of the waveform of the main pulse supplied to the die head, the waveform of the sub pulse, and the interval between the main pulse and the sub pulse. In this case, setting data for generating each main pulse and each sub pulse is stored corresponding to each piezo drive type head, and the main pulse and the sub pulse are generated based on each setting data. You may Further, the setting data may be generated by actually ejecting ink from each piezo drive type head, measuring the size of these droplets, and based on the measurement result.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an inkjet device according to the present invention will be described below with reference to the drawings.

<A. Structure of inkjet device> First,
The configuration of the inkjet device will be described. This ink jet apparatus adopts an ink jet method in which a double pulse method in which a pulse is applied twice to eject one droplet is applied. In the following description, of the two pulses, the leading pulse is called the main pulse A and the trailing pulse is called the sub pulse B.

FIG. 1 is a block diagram showing the construction of an ink jet device. The inkjet device includes a control circuit 10
0 and n head drive units U1, U2, ... Un are provided. Each head drive unit U1, U2, ...
The pulse generating circuit 200 and the piezo drive type head 300 have the same configuration.

FIG. 2 is a timing chart showing the operation of the head drive unit U1 in the ink jet device. Hereinafter, the head drive unit U1 will be described as a representative of the head drive units U1, U2, ... Un with reference to FIGS. 1 and 2, but the same applies to other head drive units.

The control circuit 100 is internally provided with a storage circuit such as a ROM, in which each set data is stored in association with each head drive unit U1, U2, ... Un. The control circuit 100 uses the first current value control signal C
1, second current value control signal C2, rise time control signal RT
C and the fall time control signal FTC are generated for each head drive unit U1, U2, ... Un. The first current value control signal C1 indicates the value of the first current i1 flowing out from the first constant current source 210, and the second current value control signal C2 is the value of the second current i2 flowing into the second constant current source 230. Instruct.
The control circuit 100 includes a first current value control signal C1 and a second current value control signal C1.
The value of the current value control signal C2 can be changed as necessary.

The rise time control signal RTC includes a first main pulse control pulse MC1 and a first sub pulse control pulse SC1 as shown in FIG. On the other hand, the fall time control signal FTC includes a second main pulse control pulse MC2 and a second sub pulse control pulse SC2 as shown in FIG.
The control circuit 100 can change the pulse widths of these pulses as needed.

The above-mentioned setting data correspond to each control signal C
The control circuit 100 generates control signals C1, C2, RTC, and FTC based on the setting data, which are parameters for generating 1, C2, RTC, and FTC. In addition, the setting data is actually each piezo drive type head U1,
Un is ejected from U2, ... Un to measure the size (droplet velocity) of these droplets, and the liquid ejected from each piezo drive type head U1, U2, ... Un based on the measurement result. Pre-formed so that the drop size is uniform.

The pulse generation circuit 200 has a control signal C
The drive pulse P is generated based on 1, C2, RTC, and FTC. The pulse generation circuit 200 includes a first constant current source 210, a first switch 220, a second constant current source 230, a second switch 240, a capacitor 250, and an operational amplifier 260, as shown in FIG.

The first switch 220 is turned on only when the rise time control signal RTC is at the high level, while the second switch 240 is turned on during the fall time control signal FTC.
Is on only during the high level period.

One end of the capacitor 250 is grounded and the other end is connected to the positive input terminal of the operational amplifier 260 at the connection point W. The operational amplifier 260 constitutes a voltage follower, and the input impedance is high impedance, while the output impedance is low impedance. Therefore, the capacitor 25
The electric charge accumulated in 0 does not flow into the operational amplifier 260, and the potential of the connection point W is determined only by the current supplied through the first switch 220 and the current flowing out through the second switch 240.

The first constant current source 210 includes a first switch 22.
When 0 is on, the first current i1 is transferred to the capacitor 25
Pour to zero. If the capacitance value of the capacitor 250 is C and the elapsed time after the first switch 220 is turned on is t, the voltage V at the connection point W of the capacitor 250 with reference to the ground potential is V = i1 · t. / C. Further, the inclinations of the main pulse A and the sub-pulse B during the period when the rise time control signal RTC is at the high level are dV / dt =
It is given by i1 / C. Here, since the current value i1 is fixed, the slope of the rising edge is constant.

Therefore, as shown in FIG. 2, when the first main pulse control pulse MC1 changes from the low level to the high level at time t1, the charging of the capacitor 250 is started and the voltage of the main pulse A increases at a constant slope. To do. Then, at time t2, when the first main pulse control pulse MC1 changes from the high level to the low level, the charging of the capacitor 250 ends. As a result, the rising edge AR is generated.

During the period from time t2 to time t3, both the rising time control signal RTC and the falling time control signal FTC are at low level, so that both the first and second switches 220 and 240 are in the off state. Thus, the charges accumulated in the capacitor 250 are retained as they are. As a result, the potential of the main pulse A becomes constant during the period from time t2 to time t3.

Next, the second constant current source 230 draws out a constant current from the capacitor 250 when the second switch 240 is in the ON state. The current value in this example is -i2.
Therefore, when the second switch 240 is turned on, the main pulse A and the sub pulse B have a slope dV / dt = -i.
It falls at 2 / C.

Therefore, as shown in FIG. 2, when the second main pulse control pulse MC2 becomes high level at time t3, the discharge of the capacitor 250 is started and the voltage of the main pulse A decreases with a constant slope. Then, when the second main pulse control pulse MC2 becomes low level at time t4, the discharging of the capacitor 250 ends. As a result, the falling edge AF occurs.

Next, in the period from time t5 to time t6, when the first sub-pulse control pulse SC1 becomes high level, the capacitor 250 is charged with electric charge as in the period from time t1 to time t2. As a result, the rising edge BR of the sub-pulse B is generated. When the second sub-pulse control pulse SC2 becomes high level during the period from time t7 to time t8, the electric charge is discharged from the capacitor 250 as in the period from time t3 to time t4. As a result, the falling edge BF of the sub-pulse B is generated.

In this way, the pulse generation circuit 200
Generates a drive pulse P composed of a main pulse A and a sub pulse B of a trapezoidal wave, and generates this drive pulse P.
Supply to 00. FIG. 3 is a sectional view showing the mechanical structure of the piezo drive type head 300. As shown in this figure, the piezo drive type head 300 includes a piezo element (piezoelectric element) 31
0 is attached to the upper part of the ink chamber 320, and the ink K is supplied to the ink chamber 310 from an ink supply unit (not shown). Further, the wall of the ink chamber 310 corresponding to the piezo element 310 has a smaller thickness than other portions, and acts like a leaf spring. The piezo element 310 is not deformed in the normal state as shown in the drawing, but is deformed in the direction of the arrow in the figure when the voltage intensity of the drive pulse P is increased. Then, the driving pulse P bends the piezo element 310, and the ink K in the ink chamber 320 is ejected from the ejection surface 340 of the nozzle 330.

The control circuit 100 includes a first current value control signal C1, a second current value control signal C2, a rising time control signal RTC, and a falling time control signal FTC for each head drive unit U1, U2, ... Un. Is generated, it is possible to adjust the waveform of the drive pulse P for each head drive unit U1, U2, ... Un. Although the amount of droplets of each piezo drive type head 300 often varies, this inkjet apparatus changes the waveforms of the main pulse A and the sub pulse B using various control signals from the control circuit 100. By doing so, it is possible to adjust each droplet amount and make each droplet amount uniform.

<B. Droplet Discharging Operation> Next, a droplet discharging operation using an inkjet device will be described with reference to FIGS. 2 and 4.
Will be described in detail with reference to. FIG. 4 is a schematic diagram showing a state of the piezo drive type head 300.

First, before the time t1 when the voltage intensity of the drive pulse P is 0 V, the upper surface and the lower surface of the piezo element 310 are parallel to each other as shown in FIG. 4 (A). At this time, the ink K in the ink chamber 320 is filled up to the ejection surface 340.

Next, when the main pulse A rises in the period from time t1 to time t2, the piezo element 310 swells upward in synchronization with this. As a result, when the internal pressure of the ink chamber 320 drops, the piezoelectric drive type head 3
In the state of 00, the ink K is sucked into the nozzle 330 as shown in FIG.

Next, in the period from time t3 to time t4, when the main pulse A falls, the piezo element 310 returns to its original state in synchronization with this. At this time, the internal pressure of the ink chamber 320 rises, the state of the piezo drive type head 300 becomes as shown in FIG. 4C, and the ink K is ejected from the ejection surface 340. The ink K ejected at the time t4 has not yet been separated from the ink K inside the nozzle 330, and is connected through the constriction Z.

Next, in the period from time t5 to time t6, when the rising edge BR of the sub-pulse B occurs, the piezo element 310 bulges upward in synchronization with this and the internal pressure of the ink chamber 320 decreases. At this time, the state of the piezo drive type head 300 is as shown in FIG. 4D, and a part of the ink K ejected from the ejection surface 340 is pulled back into the nozzle 330. As a result, the ink K ejected from the ejection surface 340 is separated into the droplet G discharged to the outside and the ink K attracted.

Next, in the period from time t7 to time t8, when the falling edge BF of the sub-pulse B occurs, the piezo element 310 returns to the original state in a state of bulging upward in synchronization with this. At this time, the piezo drive type head 30
The state of 0 is as shown in FIG.
The ink K is filled up to 40. As a result, the state of the ink K can be returned to the steady state. The advantage of the double pulse method is that the ink amount of the droplet G can be reduced by sucking the ink K.

<C. Specific Embodiment> Hereinafter, a pattern forming method using the above-described inkjet device will be described in detail. Since the inkjet device can adjust the waveform of the drive pulse P for driving the piezo drive type head 300 for each head drive unit U1 to Un, by controlling each part of the waveform of the drive pulse P described below. It is possible to adjust the size of the droplet G of the ejected ink K. As a result, it becomes possible to make the ejection amount of each piezo-type drive head 300 uniform, and it is possible to obtain a pattern-formed body of high quality without unevenness.

In particular, it can be used particularly preferably when a high-definition pattern is required to be formed, for example, when a color filter is manufactured by an ink jet method. That is, in forming a high-definition pattern, the droplet G of the ink K ejected from the head needs to be extremely small. This is because the present invention relates to the control of the size of the droplet G in the double pulse method which is preferably used when such a droplet G is extremely small.

<C-1: First Mode> A first mode is a pattern forming method characterized in that the waveform of the main pulse A is changed to control an appropriate amount of liquid ejected from the head. According to the first aspect, the size of the ejected droplet G is controlled, and finally each piezoelectric drive head 3 is controlled.
It is possible to make the sizes of the droplets G of the ink K ejected from No. 00 uniform.

The first method is to change the rising time of the main pulse A. Here, the rise time of the main pulse A is the time indicated by T1 in FIG. 2, and indicates the time from when the voltage is started to be applied in the main pulse A until the maximum voltage intensity is reached.

FIG. 5 shows the relationship between the rising time T1 of the main pulse A and the size of the droplet. As shown in FIG. 5, when the rising time T1 is increased, the speed of the droplet G ejected from the head decreases. In general, since the speed of the droplet G and the size of the droplet G are proportional to each other, it is understood that the size of the droplet G becomes smaller as the rising time T1 is increased. Therefore, the size of the droplet G can be controlled by changing the rising time T1.

More specifically, the controller 100 controls the size of the droplet G by varying the pulse width of the first main pulse control pulse MC1 shown in FIG.

Next, the second method is to change the maximum voltage intensity of the main pulse A. Here, the maximum voltage intensity of the main pulse A is the voltage intensity indicated by V1 in FIG. 2, and indicates the magnitude of the voltage applied by the main pulse A.

The relationship between the maximum voltage intensity V1 of the main pulse A and the size of the droplet G is shown in FIG. As shown in FIG. 6, as the maximum voltage intensity is increased from 80V to 150V, the speed of the droplet G ejected from the head, that is, the size of the droplet G increases. As described above, by increasing the maximum voltage intensity V1, the size of the droplet G ejected from the head can be controlled, and the size of the droplet G ejected by the entire inkjet device is made uniform. It becomes possible.

More specifically, the control unit 100 varies the values of the first current value control signal C1 and the second current value control signal C2 to vary the values of the first current i1 and the second current i2. . Depending on the values of the first current i1 and the second current i2,
The inclinations of the rising edge AR and the falling edge AF of the main pulse A are determined. Further, if the rising time T1 and the falling time (time from time t3 to time t4) are constant, the magnitude of the voltage intensity V1 is determined by the inclinations of the rising edge AR and the falling edge AF of the main pulse A. Therefore, the control unit 100 varies the values of the first current value control signal C1 and the second current value control signal C2, so that the maximum voltage intensity V of the main pulse A is increased.
1 can be changed.

Next, the third method is a method of changing the pulse width of the main pulse A. Main pulse A here
The pulse width of is the width indicated by T2 in FIG. 2 and indicates the time when the maximum voltage intensity is applied.

The relationship between the pulse width T2 of the main pulse A and the size of the droplet G is shown in FIG. Pulse width is 7 μsec.
It can be seen that the droplet G is gradually reduced by increasing from 10 μsec to 10 μsec. From this, it is understood that the size of the discharged droplet G can be controlled by changing the pulse width T2 of the main pulse.

More specifically, the control section 100 controls the pulse width T2 of the main pulse A by varying the time interval between the first main pulse control pulse MC1 and the second main pulse control pulse MC2. .

The fifth method is to change the falling time of the main pulse A. Here, the fall time of the main pulse A is the time indicated by Ta in FIG. 2, and indicates the time from when the voltage of the main pulse A changes from the maximum voltage intensity to the minimum voltage intensity. As described above, since the main pulse A ejects a droplet by the falling edge AF, the droplet amount is controlled by changing the ejection process of the droplet.

<C-2: Second Mode> In the second mode, the size of the droplet G of the ink K ejected from the head is changed by changing the waveform of the sub-pulse B. The size of the droplet G of the ejected ink K is controlled by so as to make the size of the droplet G uniform between the piezoelectric drive heads 300.

The first method is to control the size of the droplet G by changing the rising time of the sub-pulse B. Here, the rising time of the sub-pulse B is the time indicated by T4 in FIG. 2, and indicates the time from when the voltage is started to be applied as the sub-pulse B to when it reaches a predetermined voltage.

FIG. 7 shows the relationship between the rising time T4 of the sub-pulse B and the size of the droplet G. As shown in FIG. 7, the size of the droplet G is obviously different at all the voltage intensities between the rise time of 1 μsec and the rise time of 2 μsec. Therefore, by changing the rising time T4 of the sub-pulse B, it is possible to change the size of the droplet G, and thereby control the size of the droplet G from each piezoelectric drive head 300 to be uniform. It is possible. The control of the rising time T4 of the sub pulse B is performed by the control circuit 100 by varying the pulse width of the first sub pulse control pulse SC1.

Next, the second method is to change the voltage intensity of the sub-pulse B so that the piezoelectric drive head 30
This is a method of controlling the size of the droplet G discharged from 0. Here, the voltage intensity of the sub-pulse B is the voltage indicated by V2 in FIG. 2, and indicates the magnitude of the predetermined voltage applied by the sub-pulse B.

The voltage intensity V2 of this sub-pulse B and the droplet G
FIG. 7 shows the relationship between the sizes of the. As shown in FIG. 7, when the voltage intensity V2 of the sub-pulse B is increased, the size of the droplet G ejected from the piezo type drive head 300 is obviously reduced. Therefore, by changing the voltage intensity V2 of the sub-pulse B, the piezoelectric drive head 30
It is possible to control the size of the droplet G ejected from 0, and thereby it is possible to make the size of the droplet G ejected from each piezo-type drive head 300 uniform.

Here, the control of the voltage intensity V2 of the sub-pulse B is performed by the control unit 100 by the first current value control signal C1 and the second current value control signal, similarly to the second method in the above-mentioned first mode. This is done by changing the value of C2.

Furthermore, the third method of this embodiment is a method of changing the pulse width of the sub-pulse B. Here, the pulse width of the sub-pulse B is the width indicated by T5 in FIG. 2, and indicates the time when a predetermined voltage intensity is applied in the sub-pulse B.

FIG. 8 shows the relationship between the pulse width T5 of the sub-pulse B and the size of the droplet. Pulse width from 7μsec. To 1
It can be seen that the droplet B becomes larger by increasing it to 0 μsec. From this, the droplet G discharged by changing the pulse width T5 of the sub-pulse B
It turns out that the size of can be controlled.

More specifically, the control unit 100 controls the pulse width T5 of the sub-pulse B by varying the time interval between the first sub-pulse control pulse SC1 and the second sub-pulse control pulse SC2.

In the second mode, as described above, only the change of the waveform of the sub-pulse B is used, and the piezo type drive head 300 is obtained.
The droplets G may be made uniform, or may be performed by appropriately combining the methods of the second aspect and the first aspect. That is, the size of the droplet G ejected from the piezo drive head 300 may be controlled by changing the waveform of the main pulse A and the waveform of the sub pulse B at the same time. This makes it possible to more accurately control the size of the droplet G of the ink K ejected from the piezo-type drive head 300 of each head.

<C-3: Third Mode> In the third mode, the time interval between the main pulse A and the sub-pulse B (“T” in FIG. 2).
The time indicated by "3" is hereinafter referred to as an interval. ) Is changed to control an appropriate amount of liquid ejected from the head. By changing the interval T3, it is possible to change the size of the droplet G of the ink K ejected from the head, and by this, the size of the droplet G of the ink K ejected is controlled, and the piezoelectric drive is performed. The size of the droplet G is made uniform between the heads 300.

Interval T3 and piezo type drive head 3
FIG. 9 shows the relationship with the droplet G discharged from 00. As shown in this figure, the size of the droplet G can be changed by changing the interval T4. Since there is no uniform relationship such that the droplet G becomes larger when the interval T3 is lengthened, the interval T3 is changed under each condition and the correlation with the droplet size is investigated in advance, and based on the correlation. It is necessary to control the size of the droplet G.

Here, in order to control the interval T3, the control circuit 100 causes the second main pulse control pulse M
The time interval between C2 and the first sub-pulse control pulse SC1 may be changed.

The pattern forming method shown in the third aspect can be used in combination with the method shown in the first aspect and / or the method shown in the second aspect. That is, a method of changing the waveform of the main pulse A and its interval T3, a method of changing the waveform of the sub-pulse B and its interval T3, and further changing the waveforms of the main pulse A and the sub-pulse B That interval T3
Can be changed. This is because by using such a combination, the size of the droplet G can be controlled more accurately.

<D. Modifications> The present invention is not limited to the above-described embodiments, but the above-described embodiments are exemplifications, and, for example, modifications described below are possible. Further, those having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same operational effect are
Anything is included in the technical scope of the present invention.

(1) The ink jet apparatus of the above-described embodiment can be used as a part of a color filter manufacturing apparatus, but the present invention is not limited to this, and ink can be applied to a recording medium such as paper. It is needless to say that it can be applied to a printer device that ejects and prints.

(2) In the above-described embodiment, each head drive unit U1 to Un includes the piezo drive type head 30.
The drive pulse P was generated as a positive polarity pulse with reference to the drive voltage intensity (0 V: reference voltage intensity) in the normal state of 0. This is because the piezo drive type head 300 is of a type that sucks the ink K at the rising edges AR and BR of the drive pulse P and ejects the ink K at the falling edges AF and BF of the drive pulse P. On the other hand, the present invention is directed to such a piezo drive type head 30.
The present invention is not limited to 0, and may be applied to a type in which the ink K is sucked at the falling edges AF and BF of the drive pulse P and the ink K is ejected at the rising edges AR and BR of the drive pulse P. . That is, the drive pulse P may be generated as a negative pulse with reference to the drive voltage intensity (0 V: reference voltage intensity) in the normal state.

FIG. 10 is a sectional view of a piezo drive type head 300 'according to a modification, and FIG. 10A shows the behavior of the piezo drive type head 300' in a normal state, while FIG. (B) shows the behavior of the piezo drive type head 300 ′ when the ink K is sucked.
In this modified example, since the piezo element 310 is deformed in the normal state, the drive pulse P is as shown in FIG.

In this case, the falling time T1 'of the main pulse A, the rising time Ta' of the main pulse A and the falling time T3 'of the sub-pulse B are the rising time T1 of the main pulse A in the above-described embodiment. It corresponds to the falling time Ta of the main pulse A and the falling time T3 of the sub pulse B. Therefore, the control circuit 100 may generate the fall time control signal FTC so that the fall time T1 ′ of the main pulse A and the fall time T3 ′ of the sub-pulse B are appropriately changed. Further, the rise time control signal FTC may be generated in the control circuit 100 so that the rise time Ta ′ of the main pulse A is appropriately changed.

(3) In the above-described embodiment, each head drive unit U1 to Un is a piezo drive type head 300.
However, these piezo drive type heads 30
Of course, a head unit in which 0 is integrated may be used.

FIG. 12 is a perspective view showing the external structure of the head unit 300A. The head unit 300A is
A body Q and a piezo element PZ are provided. In the main body Q, orifices 300-1 to 300-n, which are ink ejection holes,
Each ink chamber partitioned by a wall is formed for each of the orifices 300-1 to 300-n. And the orifice 3
Ink is ejected from 00-1 to 300-n.

FIG. 13 is a sectional view showing the structure of the piezo element PZ. As shown in this figure, a common electrode Y is formed on the lower surface of the piezo element PZ fixed to the main body Q, and electrodes X1 to Xn are formed on the upper surface thereof.

In such a head unit 300A, each piezo drive type head 300 is provided with each orifice 30
0-1 to 300-n, orifices 300-1 to 300-
Each of the ink chambers is partitioned by a wall for every n, and each portion corresponding to each of the electrodes X1 to Xn of the piezo element PZ.

By applying this head unit 300A to the above-described embodiment, it is possible to make the droplet amounts discharged from the n piezoelectric drive heads 300 included in the head unit 300A uniform.

Also, a plurality of head units 300A may be used. In this case, the droplet amounts of all the piezo drive type heads constituting the plurality of head units 300A may be made uniform, or the droplet amounts may be made uniform for each head unit 300A. Moreover,
The droplet amount may be made uniform for a part of the piezo drive type head that constitutes a certain head unit 300A.

[0080]

As described above, according to the present invention, the amount of droplets ejected from the head is reduced by the double pulse method, and the waveform of the main pulse is changed when the double pulse method is used. Or change of sub-pulse waveform,
Furthermore, by changing the intervals of these pulses, the amount of droplets can be controlled. Therefore, the amount of ink ejected from each piezo drive head can be made uniform, and high-definition pattern formation can be obtained without causing unevenness.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an inkjet device according to an embodiment of the present invention.

FIG. 2 is a timing chart showing the operation of the device.

FIG. 3 is a cross-sectional view showing a mechanical configuration of a piezo drive type head.

FIG. 4 is a schematic view showing a state of a piezo drive type head used in the apparatus.

FIG. 5 is a graph showing the relationship between the rise time of the main pulse and the velocity (size) of the droplet.

FIG. 6 is a graph showing the relationship between the voltage intensity and pulse width of the main pulse and the velocity (size) of the droplet.

FIG. 7 shows the voltage intensity and rise time of the sub-pulse,
It is a graph which shows the relationship with the speed (size) of a droplet.

FIG. 8 is a graph showing the relationship between the pulse width of a sub-pulse and the speed (size) of a droplet.

FIG. 9 shows the voltage intensity and interval of sub-pulses,
It is a graph which shows the relationship with the speed (size) of a droplet.

FIG. 10 is a piezo drive type head 300 ′ according to a modification.
FIG.

FIG. 11 is a waveform diagram showing a waveform of a drive pulse P according to a modification.

FIG. 12 is a perspective view showing a mechanical configuration of a head unit used in a modified example.

FIG. 13 is a cross-sectional view showing a configuration of a piezo element used in the unit.

[Explanation of symbols]

A ... Main pulse B ... Sub pulse T1 ... Main pulse rise time T2 ... pulse width of main pulse T3 ... Interval T4 ... rise time of sub-pulse T5 ... pulse width of sub-pulse V1 ... Voltage intensity of main pulse V2 ... Sub-pulse voltage intensity

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masato Okabe             1-1-1, Ichigaya-Kagacho, Shinjuku-ku, Tokyo             Dai Nippon Printing Co., Ltd. F-term (reference) 2C057 AF23 AL38 AM15 AM16 AM17                       AM21 AM22 AR04 AR16 BA03                       BA14

Claims (16)

[Claims] 1. An ink jet using a double pulse method in which a piezo drive type head is used and a droplet is ejected by applying a main pulse and a sub pulse added at a predetermined interval from the main pulse to the piezo drive type head. In the pattern forming method according to the method, an appropriate amount of liquid ejected from the piezo drive type head is controlled by changing the waveform of the main pulse. 2. The main pulse and the sub-pulse are positive-polarity pulses with a drive voltage intensity in a normal state of the piezo drive type head as a reference voltage intensity,
The pattern forming method according to claim 1, wherein the change in the waveform of the main pulse is a change in the rising time of the main pulse. 3. The main pulse and the sub-pulse are negative-polarity pulses with a drive voltage intensity in a normal state of the piezo drive type head as a reference voltage intensity,
The pattern forming method according to claim 1, wherein the change in the waveform of the main pulse is a change in the fall time of the main pulse. 4. The main pulse and the sub-pulse are positive-polarity pulses with a drive voltage intensity in a normal state of the piezo drive type head as a reference voltage intensity,
The pattern forming method according to claim 1, wherein the change in the waveform of the main pulse is a change in the fall time of the main pulse. 5. The main pulse and the sub-pulse are negative-polarity pulses with a drive voltage intensity in a normal state of the piezo drive type head as a reference voltage intensity,
The pattern forming method according to claim 1, wherein the change in the waveform of the main pulse is a change in the rise time of the main pulse. 6. The pattern according to any one of claims 1 to 5, wherein the change in the waveform of the main pulse is a change in the maximum voltage intensity of the main pulse. Forming method. 7. The pattern formation by the inkjet method according to claim 1, wherein the change of the waveform of the main pulse is a change of the pulse width of the main pulse. Method. 8. The pattern formation by the inkjet method according to claim 1, wherein the droplet amount is controlled by changing the waveform of the sub-pulse. Method. 9. An inkjet using a double pulse method, wherein a piezo drive type head is used, and a main pulse and a sub pulse added at a predetermined interval from the main pulse are applied to the piezo drive type head to eject droplets. A pattern forming method by an inkjet method, wherein an appropriate amount of liquid ejected from the piezo drive type head is controlled by changing a waveform of the sub-pulse. 10. The main pulse and the sub-pulse are positive-polarity pulses with a drive voltage intensity in a normal state of the piezo drive type head as a reference voltage intensity, and a change in the waveform of the sub-pulse is a rise time of the sub-pulse. 10. The pattern forming method by the inkjet method according to claim 9, wherein 11. The main pulse and the sub-pulse are negative-polarity pulses with a drive voltage intensity in a normal state of the piezo drive type head as a reference voltage intensity, and a change in the waveform of the sub-pulse causes a fall of the sub-pulse. The pattern forming method by an inkjet method according to claim 9, which is a change with time. 12. The pattern forming method according to claim 9, wherein the change in the waveform of the sub-pulse is a change in the maximum voltage intensity of the sub-pulse. . 13. The pattern forming method according to any one of claims 9 to 12, wherein the change in the waveform of the sub-pulse is a change in the pulse width of the sub-pulse. 14. The amount of liquid droplets ejected from the head is controlled by changing an interval between the main pulse and the sub pulse.
The pattern forming method according to any one of claims 1 to 13 by an inkjet method. 15. An ink jet using a double pulse method, wherein a piezo drive type head is used, and a droplet is ejected by applying a main pulse and a sub pulse added at a predetermined interval from the main pulse to the piezo drive type head. In the pattern forming method according to the method, an appropriate amount of liquid ejected from the piezo drive type head is controlled by changing an interval between the main pulse and the sub pulse, and a pattern forming method by an inkjet method. 16. A plurality of piezo drive type heads are provided, and the waveform of the main pulse and the sub pulse supplied to each piezo drive type head are adjusted so that an appropriate amount of liquid ejected between the piezo drive type heads becomes uniform. The pattern forming method according to any one of claims 1 to 15, wherein at least one of a waveform, the main pulse, the sub pulse, and an interval is adjusted.