JPS5835152B2 - Ink jet yoga couch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inkjet calligraphy device that is capable of printing a desired image, such as a television image, using a large number of ink droplets ejected at high speed.

First, with reference to FIG. 1, a conventional inkjet writing and drawing apparatus of this type will be described.

In FIG. 1, 1 is an inkjet gun, and ink particles 2 are ejected at high speed from a nozzle 1a of the gun.

In this case, the inkjet gun 2 is vibrated at a frequency of, for example, around 50 KHz in the ejection direction LC of the ink particles 2, and after the ink particles 2 leave the nozzle 1a due to the vibration of the inkjet gun 1, they are immediately reduced to 1c pieces. It separates independently and forms a column of particles.

These ink particles 2 are charged on charged electrode plates 3a, 3 facing each other.
b, and between mutually opposing deflection electrode plates 4a and 4b.

And a charged electrode plate 3a. 3b is a drawing signal generation circuit 9
As a result, a DC pulse voltage of, for example, about 400 cm is applied (in the illustrated example, it is applied so that the charging electrode plates 3a and 3b side are positive and the inkjet gun side is negative), and a calligraphy image passing between the electrode plates 3a and 3b is applied. The ink particles to be subjected to the process are, for example, negatively charged.

On the other hand, the deflection electrode plate 4a. 4b, for example, the electrode plate 4b is grounded, the other electrode plate 4a is connected to the positive electrode of a DC power supply (the negative electrode is grounded), and both electrode plates 4a
, 4b, a constant deflection electric field is formed between them.

In this way, among the ink particles 2 passing between the deflection electrode plates 4a and 4b, the charged calligraphy ink particles 2b are deflected upward as shown in the figure, and the uncharged unnecessary ink particles 2a are deflected upward. Go straight ahead.

Then, only the deflected ink particles 2b for calligraphy and drawing collide with the recording paper 7 placed in front and are adhered thereto for use in calligraphy and drawing.

Note that the recording paper 7 is wound around a drum 8 and moves along with the drum 8 in the width direction and longitudinal direction, so that the ink particles 2b for calligraphy and painting are
scans the recording paper 7.

Further, the unnecessary ink particles 2a that have traveled straight are collected by the catcher 5 and stored in the ink reservoir 10, and are further collected by the pressure pump 1.
1 and then supplied to the inkjet gun 1 again through the vibro.

Reference numeral 12 denotes a filter, which is used to remove unnecessary dust and the like from the ink.

However, in the above-mentioned inkjet calligraphy device, when the calligraphy ink particles 2b are charged and brightened according to the pulse voltage from the calligraphy signal generation circuit 9, the amount of charge of each calligraphy ink particle is kept constant. In order to do this, for example, phase synchronization is performed to match the timing of ink particle formation and pulse voltage application so that the IIC Hals voltage is applied to the electrode plates 3a and 3b at the moment when ink is ejected from the inkjet gun 1 and formed as particles. It is necessary to take it accurately.

When this phase synchronization deviates, the amount of charge on the ink particles changes O1.Therefore, the deflection of the charged ink particles on the electrode plate 4a,
If the deflection amount 75E changes within the recording paper 4b, it becomes difficult to attach the calligraphy ink particles to a predetermined position on the recording paper.

In the above-mentioned conventional inkjet calligraphy device, the particle generation frequency is around 50 KHz, but when a high frequency of 100 KHz or more is used to increase the resolution of calligraphy, etc., it is necessary to charge the ink particles 2b according to the calligraphy signal. requires stricter phase synchronization, which is currently difficult to implement in terms of stability.

In addition, in order for the calligraphy ink particles charged to the same polarity according to the pulse voltage to repel each other, as shown in the calligraphy and drawing part 13 in FIG.
Uncharged ink particles 2a are inserted every other time.

Reference numeral 14 is a non-drawing portion.

For this reason, only half of the calligraphy ink particles 2b on the recording paper 17 could be utilized.

Furthermore, when generating ink particles at a high speed, it is necessary to synchronize the phase between the time of particle formation and the time of pulse voltage application, which requires the incorporation of a time detection device.
The structure 75 of this type of drawing and drawing device has become more complicated.

In view of the above-mentioned points, the present invention provides an inkjet calligraphy device of this kind that eliminates the need for phase synchronization to match the timing of ink particle formation and voltage application for charging, and achieves higher speed and higher density. The present invention provides an inkjet writing and drawing device that can be expected to achieve high resolution.

In the present invention, in an inkjet drawing device that includes an inkjet gun, a charging electrode plate to which a charging signal is applied based on an original image signal, and a deflection electrode plate, the deflection electrode can be used without charging the calligraphy ink particles. The ink particles travel straight through the plate and are deposited on the recording paper, and unnecessary ink particles used in calligraphy and drawings are charged and collected by deflection I7 in the deflection electrode plate.

Embodiments of the inkjet drawing apparatus according to the present invention will be described below with reference to FIG. 3 and subsequent figures.

FIG. 3 is a layout diagram showing the entire inkjet drawing device of the present invention.

Figure 3 V: 21 is an inkjet gun that ejects a large number of ink particles 22 at high speed.This inkjet gun 21 vibrates at a predetermined frequency in the direction of ink droplet ejection, as usual, and burns. After the ink particles 22 exit the nozzle 22a due to the vibration of the inkjet gun 21, they are immediately separated into individual particles to form a row of particles.

23a and 23b are charged electrode plates to which a charging signal based on an original image signal is applied, 24a and 24b are deflection electrode plates facing each other, and the ink particles 22 from the inkjet gun 21 are distributed between the charged electrode plates 23a and 23b. and the deflection electrode plates 24a and 24b.

Reference numeral 29 denotes a charging signal generating circuit which applies a charging signal based on the original image signal to the charging electrode plates 23a and 23b.

In this case, the charging signal is the unnecessary ink 22a that is not used for calligraphy or painting.
It is possible to use only a small signal such as charging or dipping, for example, a DC pulse signal whose pulse width is modulated by I corresponding to the density of the original image.

In this case, the DC pulse voltage is applied to the charged electrode plate 23a.
, 2'3b side force S is positive, and the inkjet gun 21 side is applied so that it is negative.

On the other hand, in the deflection electrode plates 24a and 24b, for example, the electrode plate 24a is grounded, and the other electrode plate 24b is connected to the DC power source B.
(the negative electrode is grounded), and a constant deflection electric field is formed between the electrode plates 24a and 24b.

In this way, the ink particles 22 ejected from the inkjet gun 21 and passing between the charged electrode plates 23a and 23b are as follows:
Negative charging is performed only when a voltage is output from the circuit 29, that is, only unnecessary ink particles 22a that are not used for calligraphy and drawing are charged, and calligraphy ink particles 22b that are used for calligraphy and drawing are not charged.

When the ink particles 2T that have passed between the charged electrode plates 2.3a and 23b pass between the deflection electrode plates 24a and 24b, the unnecessary ink particles 22a charged by the charged electrode plates 23a and 22b are removed as shown in the figure. and deflect downward,
The outlet side of the deflection electrode plates 24a, 24b ((collected by the catcher 25 arranged therein, the uncharged calligraphy ink particles 22b are allowed to advance straight to the recording paper 27 wound around the drum 28).
Make it collide with the top and stick to it.

Here, the catcher 25 includes weakly charged unnecessary particles 22a that adhere to the catcher 25, as will be described later.
Means are provided for removing.

The recording paper 27 is moved relative to the inkjet gun 21 in the irr width direction and the longitudinal direction.
Calligraphy and drawing ink particles 22b75: Made to be scanned.

Further, the ink collected by the catcher 25 is stored in an ink reservoir 30, further supplied to a pressure pump 31 to be pressurized, and then supplied to the inkjet gun 21 again through a pipe 26 and a filter 32. Eggplant.

Next, an example of a specific configuration of this charging signal generating circuit 39 will be explained with reference to FIG.

In FIG. 4, 33 is a pulse generator.

The frequency of the pulse is selected to be, for example, the ink droplet formation frequency of the inkjet gun 21 described above.

This pulse signal from the generator 33 has a frequency division ratio of -1, for example, 4', which is supplied to the frequency dividing circuit 35' and then divided.
5 to a sawtooth wave signal generator 36 to obtain a sawtooth wave signal synchronized with the frequency of the output of the frequency dividing circuit 35.

A comparison circuit 37 compares the original image signal to be printed from the original image signal 38 with the sawtooth wave signal from the sawtooth wave signal generator.

Then, the comparative output is supplied to the inverter 34.

Note that 39p and 39m are output terminals of the inverter 34, and are a positive terminal and a negative terminal, respectively.

Then, the output terminal 39p is connected to the charged electrode plate 23a of FIG.

23b, and the output terminal 39m is connected to the inkjet gun 21.

Next, this operation will be explained with reference to the waveform diagram in FIG.

The pulse a from the pulse generator 33 is as shown in FIG. 5A.

A pulse signal whose frequency is divided by the frequency dividing circuit 35 of this pulse signal a is shown as Bvcb in FIG.

Further, in FIG. 5C, the sawtooth signal output from the sawtooth signal generator 36 is shown as C.

In the fifth diagram, d is the original image signal from the original image signal source 38, and as the density of the original image increases,
This is the signal that the novel becomes a dog.

Then, as shown in Figure 5, the comparison circuit 37 compares the sawtooth wave signal C and the original image signal d.

When the level of the original picture signal d is lower than the level of the sawtooth wave signal C, a comparison output e shown in FIG. 5E is obtained.

That is, this comparison output e is a signal that becomes 1 when the level of the original image signal d is higher than that of the sawtooth wave signal C, and jumps to 0 when the level is lower than that of the sawtooth wave signal C.

Furthermore, this comparison output is supplied to the e-crab inverter 34 and the fifth
As shown in Figure F, an inverted output f is obtained at its output terminals 39p and 39m.

That is, this output f corresponds to each period j1 t j2 p j3 t j4 pt of the pulse signal from the frequency dividing circuit 35.
5, then the original picture transposition d corresponding to each period V-multi
Depending on the gradation of the original image, the width becomes smaller, and as the density of the original image becomes smaller, it becomes a signal that is modulated during the pulse.

Therefore, the fifth button [D4. The ink particles 22a passing between the charged electrode plates 23a and 23b during the period when the output f of F, that is, the pulse signal is applied, are charged and collected, and during the period when the pulse signal is not applied, the ink particles 22a pass between the charged electrode plates 23a and 23b. Ink particles 22b passing between 23b
In this example, one pixel is formed by four ink particles.

(In this case, each pulse signal in FIG. 5A corresponds exactly to each ink droplet 22 from the inkjet gun 21.) Therefore, in period t1, the pixels on the recording paper 27 are white,
In the periods t2 to t4, the respective gradations are gray and dark, and in the period t5, they are black.

In the above-mentioned calligraphy and drawing apparatus shown in FIG. 3, the charged ink particles 22a are collected by the catcher 25, and even if the amount of charge varies, the charged ink particles 22a are collected by the deflection electrode plate 24a.

Even if the amount of deflection within the catcher 24b fluctuates, in most cases it will be collected within the catcher 25 and there will be no problem. For particles, the same catcher as before
When using the catcher 25, it is expected that the amount of deflection will be small as shown by the reference numeral 22' in Fig. 6, so that it will stick to the upper side of the catcher 25, and if this happens, the normal flying of calligraphy ink particles will occur. inhibit.

FIGS. 7 to 9 show improved examples of catcher means for this purpose.

In FIG. 7, a catcher 41, which is a dish-shaped rotating member, is arranged so that its inner surface 41a faces the direction in which charged particles travel, and is slowly rotated about a shaft 42. A wiping means, such as a felt brush 43, is in contact with the outer surface 1c of the dish-shaped catcher 41 at a position that does not interfere with the flight of the calligraphy ink particles 22b.
This is the case when it is configured by arranging.

According to this, many unnecessary ink particles 22a are collected in the ink reservoir along the inner surface of the dish-shaped catcher 41, and even if the ink particles 22a with a small amount of charge are
Even if it sticks to the outside, it can be wiped away with the brush 43 and normal calligraphy and drawings can be recorded.

The catcher 46 shown in FIG. 8 has an air suction part 45 on the outside of the collecting part 44 for collecting ink particles, and when ink particles stick to the outer end 44a of the collecting part 44, the air flows through the air suction part 45. This is a case where the adhered ink particles are removed by air flow.

FIG. 9 shows a dish-shaped catcher 48, which is an annular rotating member having a through hole 47 in the center through which the straight-advancing calligraphy ink particles 22b pass, and which is supported on a bearing 49.
This is a case in which a catcher 48 is configured to rotate at high speed around the catcher 48, and a receiving portion 50 is disposed on the outer periphery of the catcher 48 to receive the scattered ink collected in the catcher.

In this case as well, it is possible to avoid adhesion of ink particles with a small amount of charge.

According to the above-described inkjet calligraphy apparatus 1' of the present invention, unnecessary ink particles 22a that are not used for calligraphy are charged and collected, and calligraphy is performed only with uncharged straight-moving ink particles 22b. There is no need to consider timing alignment between the charging signal and the ink droplet formation time in order to keep the amount of charging constant as in the case of FIG.

For this reason, in 1F, it is possible to raise the ink droplet generation frequency, which was conventionally around 50KHz, to a high wavenumber of 100KHz or more, and because ink droplets can be formed at high frequencies, the formation of ink droplets becomes smaller, and intermediate notes can be It is possible to improve the resolution of calligraphy and drawings as well as improve the quality of the drawings.Also, since there is no need to consider phase synchronization for timing alignment, it is possible to omit devices and circuits for phase synchronization, and the configuration is also simplified.

Further, since the charged unnecessary ink particles 22b are collected by the catcher 25 and are not used for calligraphy or painting, no matter which direction they are deflected, it is preferable to alternately arrange charged ink particles and non-charged ink particles as shown in FIG. The ink particles can be stopped and charged continuously as shown in FIG. 3, and therefore the ink particles can be utilized twice as efficiently as in the past.

Since continuous charging is possible, it is expected that the density of the calligraphy will be doubled.

Further, separate from the electrode plates 24a and 24b for deflecting unnecessary charged ink particles, a catcher 41, 46, or 48 for collecting charged ink particles is provided on the outlet side of the electrode plate, and this catcher is further provided with a catcher 41, 46 or 48 for collecting charged ink particles. Means for removing persistent weakly charged ink particles 42, 43, 45. or 49°50
By providing this, it is possible to simplify the structure of the entire apparatus, and in addition, there is no obstruction to the normal flight of calligraphy ink particles, making it possible to perform more accurate calligraphy printing.

[Brief explanation of the drawing]

FIG. 1 is a layout diagram showing an example of a conventional inkjet calligraphy device, FIG. 2 is a diagram showing the state of ink particles for explanation thereof, and FIG. 3 is a layout diagram showing an example of an inkjet calligraphy device according to the present invention. FIG. 4 is a circuit diagram showing an example of a charging signal generation circuit applied to the present invention, FIG. 5 is a waveform diagram for explaining the operation of the circuit, and FIG. 6 is a catcher portion for explaining the present invention. 7 to 9 are sectional views showing other examples of the catcher applied to the calligraphy and drawing apparatus of the present invention. 21 is an inkjet gun, 22a is unnecessary ink particles,
22b is ink particles for calligraphy and painting; 23a; 23b is a charging electrode plate, 24a and 24b are deflection electrode plates, 2
5 is a catcher, 126 is a pipe, 27 is a recording paper, 28
is a drum, 29 is a charging signal generation circuit, 30 is an ink reservoir,
31 is a pressure pump, and 32 is a filter.

Claims (1)

[Claims] 1. An inkjet calligraphy and drawing device configured to allow ink particles for calligraphy and drawing to advance in a straight line in an uncharged state, and to charge and collect unnecessary ink particles, comprising a charged electrode plate for the above-mentioned ink particles for calligraphy and drawings, and an electrode for deflecting the above-mentioned unnecessary charged ink particles. A catcher means for collecting charged ink particles is provided on the outlet side of the plate and the deflecting electrode plate, and the collecting catcher means 1/r is a rotating member in the form of a plate facing the traveling direction of the charged ink particles. An inkjet drawing device comprising means for removing unnecessary ink particles adhering to the rotating member.