JPH10250083A - Electrostatic suction type multi-nozzle inkjet recording device - Google Patents

Abstract

A conventional electrostatic suction type multi-nozzle ink jet recording apparatus continuously applies a bias voltage to a multi-nozzle head, and superimposes the bias voltage on the bias voltage to control the vibration state of an ink meniscus in each nozzle. In order to form it, a pulse voltage for excitation is periodically applied, and a print voltage is applied to each gate electrode in synchronization with the application of the pulse voltage for excitation. In this case, the amplitude of the meniscus is reduced due to the bias voltage. It becomes smaller and hinders high-speed flight of ink. SOLUTION: A bias voltage B is applied to a multi-nozzle head 1.
V is not applied, and only the excitation pulse voltage SV enough to form a large meniscus Ma on each nozzle 1a is periodically applied, and the printing voltage is synchronized with each gate electrode 2a when the excitation pulse voltage SV is applied. Apply PV.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic suction type ink jet recording apparatus which improves the ink flying property for enabling high-speed printing.

[0002]

2. Description of the Related Art The structure of a conventional electrostatic suction type multi-nozzle ink jet recording apparatus will be described with reference to FIGS. FIG. 1 is a schematic front sectional view showing a configuration of a conventional electrostatic suction type multi-nozzle ink jet recording apparatus, FIG. 2 is a schematic front sectional view showing a vibration state of a meniscus M at the tip of a nozzle 1a, and FIG. 3 is a conventional bias voltage BV. , Excitation pulse voltage SV and print voltage PV at each gate electrode 2a
FIG. 6 is a time chart showing the application timing of.

As shown in FIG. 1, a gate electrode substrate 2 having a plurality of gate electrodes 2a opposed to each nozzle 1a is interposed between a multi-nozzle head 1 having a plurality of nozzles 1a and a back electrode substrate 3. In addition, the recording medium (recording paper) P conveyed between the gate electrode substrate 2 and the back electrode substrate 3 is configured to adhere and record ink I flying from each nozzle 1a. Assuming that the number of nozzles 1a in the multi-nozzle head 1 is N, there are also N gate electrodes 2a.

As a voltage applying means for flying ink,
A print voltage PV is applied to each gate electrode 2a,
The ink flies from the nozzle 1a facing the gate electrode 2a to which the print voltage PV (for example, 75 to 500 V) is applied. Here, in order to smoothly fly the ink I from the nozzle 1a, conventionally, the multi-nozzle head 1
The bias voltage BV which is a constant voltage (for example, -1
000 to -500 V), and the meniscus M of the ink I is always formed from each nozzle 1a by this voltage. Then, in order to further vibrate the meniscus M to further improve the ink flying property, the multi-nozzle head 1 superimposes the bias voltage BV on the multi-nozzle head 1 to generate the excitation pulse voltage S which is a pulse voltage of a constant frequency.
V (for example, −1000 to −500 V) was applied.
That is, as shown in FIGS. 2 and 3, when the excitation pulse voltage SV is not applied, a small meniscus Mb is formed in each nozzle 1a with only the bias voltage BV applied.
When the excitation pulse voltage SV is applied, the bias voltage B
V and the excitation pulse voltage SV (−2000 to −1
000V), a large meniscus Ma is formed. Therefore, by applying the excitation pulse voltage SV periodically, the meniscus M vibrates so as to repeat the state of the large meniscus Ma and the state of the small meniscus Mb.

As shown in FIG. 3, the application timing of the printing voltage PV to each gate electrode 2a is synchronized with the application timing of the excitation pulse voltage SV so as to be in the state of a large meniscus Ma where ink is most likely to fly. Things.

[0006]

However, the application has been made on the assumption that the ink is effective for flying. However, in this case,
Since the small meniscus Mb is formed when the excitation pulse voltage SV is not applied, the amplitude L1 (shown in FIG. 2) with the large meniscus Ma is small.
That is, even if the meniscus M is always formed, it is found that the start of the flight of the ink I from the nozzle 1a becomes slower because the amplitude L1 is small, and it takes time to fly the ink.

[0007] One ink flying time is determined by one application cycle (one ON / OFF) of the excitation pulse voltage SV shown in FIG.
Is set at the time) t ₁ required to. In order to increase the printing speed, one application period t ₁ of the excitation pulse voltage SV may be shortened as much as possible. However, due to the above-described reasons, there is a limit in shortening the one application period t _1. Accordingly, it has been found that the maximum applied frequency n ₁ of the excitation pulse voltage SV is about 300 Hz (that is, the minimum limit value of one application cycle t ₁ is about 1/300 sec). Therefore, the number of ink jets per second can be set only up to about 300 at the maximum, and there is a limit in increasing the printing speed.

[0008]

The present invention uses the following means in order to solve the above problems. First, between the multi-nozzle head having a plurality of nozzles and the back electrode substrate, a gate electrode substrate having a plurality of gate electrodes facing each nozzle is provided,
A pulse voltage for excitation is periodically applied to the multi-nozzle head in a state of no voltage, a print voltage is applied to each gate electrode on the gate electrode substrate, and the print voltage is applied to the gate electrode to which the applied voltage is applied. An electrostatic suction type multi-nozzle ink jet recording apparatus that causes ink to fly from a nozzle to be formed.

Second, in the electrostatic suction type multi-nozzle ink jet recording apparatus having the above-described configuration, the meniscus of the ink formed from each nozzle of the multi-nozzle head is controlled by the excitation pulse voltage applied to the multi-nozzle. Control the amplitude.

Third, in the electrostatic suction type multi-nozzle ink jet recording apparatus having the above-described configuration, the print voltage applied to each gate electrode is synchronized with the application timing of the excitation pulse voltage.

[0011]

Embodiments of the present invention will be described with reference to the accompanying drawings. 4 is a schematic front sectional view showing the configuration of the electrostatic suction type multi-nozzle ink jet recording apparatus of the present invention, FIG. 5 is a schematic front sectional view showing the vibration state of the meniscus M at the tip of the nozzle 1a in the present invention, and FIG. FIG. 5 is a time chart showing application timings of an excitation pulse voltage SV and a print voltage PV at each gate electrode 2a.

In the electrostatic suction type multi-nozzle ink jet recording apparatus according to the present invention shown in FIG. 4, the same reference numerals used in FIG. 1 which disclose the prior art indicate the same members. That is, in the embodiment of the electrostatic suction type multi-nozzle ink jet recording apparatus of the present invention, the ink I
And a multi-nozzle head 1 having a plurality of (N) nozzles 1a and (N) nozzles facing each nozzle 1a
A recording medium P transported between the gate electrode substrate 2 and the back electrode substrate 3, comprising a gate electrode substrate 2 having a gate electrode 2 a and a back electrode substrate 3; I is attached and recorded.

In the present invention, the multi-nozzle head 1
, The conventional bias voltage BV is not applied, and only the excitation pulse voltage SV having a fixed period is applied as shown in FIG. Therefore, when the excitation pulse voltage SV is not applied (interval period), the multi-nozzle head 1 is in a no-voltage state, and as shown in FIG. Retraction, the state where the meniscus M disappears, or the extremely small meniscus M
It becomes the state of c. On the other hand, the excitation pulse voltage SV is set to a voltage (−2000 to −1000) corresponding to the superposition of the bias voltage BV and the excitation pulse voltage SV in the above-described conventional technique.
V), the large meniscus Ma described in the related art is formed when the excitation pulse voltage SV is applied.

Therefore, between the time when the excitation pulse voltage SV is applied and the time when the excitation pulse voltage SV is not applied, a meniscus M having a large amplitude L2 that vibrates by repeatedly repeating a large meniscus Ma and an extremely small meniscus Mc is provided at the tip of each nozzle 1a. (L2 <L1).

In a state where the meniscus M of the ink I is oscillated at the tip of the nozzle 1a with such a large amplitude, as shown in FIG.
Is large, that is, if the excitation pulse voltage SV is applied in synchronization with the application, the ink I flies very smoothly and at high speed from each nozzle 1a. That is, in the present embodiment, one application cycle t ₂ of the excitation pulse voltage SV for setting one ink flight time can be significantly reduced (t ₂ <t ₁ ), and the excitation pulse voltage SV Applied frequency n
₂ can be set to about 2000 Hz at the maximum. That is, it is possible to set the number of times of ink flight to about 2000 times per second (one application cycle n ₂ of the excitation pulse voltage SV can be reduced to 1/2000 sec).

[0016]

As described above, the electrostatic suction type multi-nozzle ink jet recording apparatus of the present invention has the following effects. First, an excitation pulse voltage of a constant frequency pulse is applied to a multi-nozzle head in a non-voltage state, and the excitation voltage is changed from a state in which a bias voltage is continuously applied as in the prior art. When a pulse voltage is superimposed and applied, the ink meniscus is formed by the amount of the bias voltage even when the excitation pulse voltage is not applied, whereas no voltage is applied when the excitation pulse voltage is not applied. Therefore, the amount of ink withdrawal at the nozzle tip increases, and the meniscus at this time becomes extremely small.

According to the first aspect of the present invention, the amplitude of the meniscus of the ink is controlled by the excitation pulse voltage.
The amplitude of the meniscus of the ink that vibrates between the time when the excitation voltage is not applied and the time when the excitation voltage is applied increases. Due to such an increase in the amplitude of the ink meniscus, the ink is more likely to fly more smoothly and faster than the nozzles.

According to a third aspect of the present invention, the printing voltage is applied to the gate electrode in synchronism with the meniscus state in which the nozzle flies most easily when the excitation pulse voltage is applied, so that the ink can smoothly move at a higher speed than the nozzle. Is to fly.

According to the above-described first to third aspects,
The flying speed of the ink is improved, which contributes to higher printing speed in the electrostatic suction type multi-nozzle ink jet recording apparatus.

[Brief description of the drawings]

FIG. 1 is a schematic front sectional view showing a configuration of a conventional electrostatic suction type multi-nozzle inkjet recording apparatus.

FIG. 2 is a schematic front sectional view showing a state of vibration of a meniscus M at the tip of a nozzle 1a in the related art.

FIG. 3 shows a conventional bias voltage BV and excitation pulse voltage S
FIG. 4 is a time chart showing the timing of applying a print voltage PV to V and each gate electrode 2a.

FIG. 4 is a schematic front sectional view showing a configuration of an electrostatic suction type multi-nozzle inkjet recording apparatus of the present invention.

FIG. 5 shows a meniscus M at the tip of the nozzle 1a in the present invention.
3 is a schematic front cross-sectional view showing a vibration state of FIG.

FIG. 6 is a time chart showing application timings of an excitation pulse voltage SV and a print voltage PV at each gate electrode 2a in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multi-nozzle head 1a Nozzle 2 Gate electrode substrate 2a Gate electrode 3 Back electrode substrate P Recording medium SV Excitation pulse voltage PV Print voltage

Claims (3)

[Claims] A gate electrode substrate having a plurality of gate electrodes facing each nozzle is interposed between a multi-nozzle head having a plurality of nozzles and a back electrode substrate. A pulse voltage for excitation is periodically applied to a state of no voltage, a print voltage is applied to each gate electrode of the gate electrode substrate, and ink is ejected from a nozzle opposed to the gate electrode to which the gate voltage is applied. An electrostatic suction type multi-nozzle inkjet recording apparatus characterized by the above-mentioned. 2. The electrostatic suction type multi-nozzle ink jet recording apparatus according to claim 1, wherein a meniscus of ink formed from each nozzle of said multi-nozzle head is generated by an excitation pulse voltage applied to said multi-nozzle. An electrostatic suction type multi-nozzle ink jet recording apparatus characterized by controlling the amplitude of the ink. 3. The electrostatic suction type multi-nozzle ink jet recording apparatus according to claim 1, wherein a print voltage applied to each gate electrode is synchronized with an application timing of an excitation pulse voltage. Suction type multi-nozzle inkjet recording device.