JP3442586B2 - Ink jet recording device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and in particular, it concentrates a coloring material component in liquid ink by a force from an individual electric field generated by a voltage applied to an array of individual electrodes, thereby reducing the size of the ink. The present invention relates to an inkjet recording device having a slit-shaped nozzle for flying as a droplet.

[0002]

2. Description of the Related Art Conventionally, an ink jet type printer is known in which liquid ink is ejected onto a recording medium to form recording dots. Such an ink jet recording apparatus has the advantages that it is less noisy and does not require processing such as development and fixing, as compared with other recording methods, and has attracted attention as a plain paper recording technology.

To date, many ink jet recording methods have been proposed. For example, a method of flying ink droplets with the above-mentioned pressure generated by the heat of a heating element is disclosed in Japanese Patent Publication No. 56-9429 and Japanese Patent Publication No. 61-599.
No. 11, for example. On the other hand, a method of ejecting ink droplets by a mechanical pressure pulse generated by a piezoelectric body is disclosed in Japanese Patent Publication No. 53-12138.

In particular, the techniques disclosed in the above-mentioned patent publications are typical as a multi-nozzle type in which a plurality of dots are arranged in parallel and a plurality of dots are recorded. The recording heads proposed by these techniques are mainly mounted on a carriage and put to practical use as a serial scan type head that repeats scanning in a direction perpendicular to the recording paper conveyance direction.

On the other hand, instead of mounting the recording head on the carriage, the type of system in which the multi-nozzles are arranged on the recording head having the same size as the width of the recording paper can reduce the moving parts and increase the recording speed. . However, it is not easy to actually manufacture such a line scanning recording head.

That is, in the system in which the nozzles are made multi,
Local concentration of ink is likely to occur due to evaporation or evaporation of the solvent. Therefore, the individual thin nozzles arranged corresponding to the resolution required for printing cause clogging.
Especially in the method that uses the pressure of steam,
Alternatively, adhesion of insoluble matter due to chemical reaction or the like becomes a problem. On the other hand, in the method using the pressure of the piezoelectric body, a complicated structure such as an ink flow path easily causes clogging.

However, due to technological innovation, from dozens of
With a serial scan type printhead that requires hundreds of nozzles, it is not so difficult to keep the frequency of clogging low, but a line scan type structure in which several thousand nozzles are arranged In this case, the nozzle is still clogged with probability quite frequently, which is a major problem in ensuring reliability.

On the other hand, in the case of the ink jet system, it is very difficult to increase the resolution. That is, it is very difficult to generate a droplet diameter of 20 μm or less in the case of using the vapor pressure. Diameter 20μ
An ink droplet having a particle diameter of m has a diameter of 50 μm on the recording surface.
It is very difficult to realize a resolution higher than this, which is expressed as a recording dot of. Further, in the case of using the pressure of the piezoelectric body, there is a problem that it is difficult to form a head with high resolution due to restrictions in processing technology due to its complicated structure.

In order to overcome the above problems, a method is proposed in which a voltage is applied to a thin-film electrode array and the force of static electricity is used to fly the ink or the colorant component therein from the ink surface. Has been done. For example, as a method of ejecting ink by using electrostatic attraction, Japanese Patent Application Laid-Open Publication No. Sho.
9-62024 and Japanese Patent Laid-Open No. 56-4467 have been proposed, and as a method of increasing the concentration of a colorant and flying it using an ink containing a charged colorant component, Japanese Patent Publication No. Japanese Patent No. 502218 has been proposed.

These methods do not require nozzles for individual dots or partition walls of ink flow paths, and can adopt a slit-shaped nozzle or a nozzleless structure, which is a major obstacle in making a recording head into a line. It is said to be an effective method for preventing clogging and recovering. In particular, the method of increasing the concentration of the colorant and flying the ink by using the ink containing the charged colorant component can stably generate and fly the ink particles having a very small diameter, and thus can achieve high resolution. Are suitable.

FIG. 19 is a schematic configuration diagram of such a conventional ink jet recording apparatus. In particular, a liquid ink in which a charged coloring material is mixed in a solvent is used, and the ink is increased in the concentration of the coloring material. The method of flying is illustrated.

As shown in the figure, the recording head 1 includes an ink holding portion 5 composed of a substrate and an upper lid,
The ink 4 containing the charged coloring material is supplied from an ink tank (not shown) in the direction of the arrow.

A large number of recording electrodes 1a are formed in an array on the substrate of the recording head 1 and are connected to a control circuit 50. Then, the control circuit 50 is supplied with power from the recording power supply 51.

On the other hand, the upper lid of the recording head 1 is provided with an auxiliary electrode 13 for moving the coloring material toward the tip of the recording head 1.
Is provided, and the auxiliary electrode 13 has a power source 1 for the auxiliary electrode.
4 is connected.

Further, the recording medium 12 is in close contact with the recording drum 11 which is connected to the ground potential, and the recording head 1
Go around the area in the direction indicated by the arrow.

The ink 4 contains a charged colorant,
As an example of such an ink, a liquid developing toner used in a liquid developing type electrophotographic recording apparatus is generally known. Here, the coloring agent contained in the ink 4 is
For example, assume that it is positively charged.

Now, the recording electrode 1a and the auxiliary electrode 13 have
Bias voltage with different potential, eg 1.4k each
V and 2.0 kV are applied, and the electric field formed between these electrodes moves the charged coloring material.

In this case, the auxiliary electrode 1 is more preferable than the recording electrode 1a.
Since the potential of No. 3 is set high, the charged coloring material is concentrated near the recording electrode 1a, and the density is increased. When the pulsed signal voltage is supplied in such a state, the concentrated coloring material receives the repulsive force from the recording electrode 1a and the suction force from the recording drum 11 and is ejected from the tip of the recording electrode 1a. The ejected ink droplet 4a forms the recording electrode 1a.
An electric field flies in the electric field between the recording drum 11 and the recording drum 11, and the recording medium 12 is elastically attached to the recording medium 12 to form an image.

In such an ink jet recording apparatus,
An electric field formed between the recording electrode 1a and the auxiliary electrode 13 is designed to send the coloring material in the ink holding portion 5 to the tip. On the other hand, if the direction of the electric field is reversed, the coloring material will be reversed. It can also be collected in the ink holding unit 5. That is, one of the features is that it is possible to control the inflow and outflow of the coloring material from the ink holding unit 5 according to the state of the apparatus.

However, when the coloring material is collected, the coloring material concentration inside the ink holding portion 5 rises, so that the coloring material may adhere to the inside of the ink holding portion 5. In this way, when the colorant adheres, the amount of the colorant that can be supplied decreases, and the adhered colorant may interfere with the moving colorant, making it difficult to supply the next colorant. Become.

Further, even when the apparatus is left for a long time with the power turned off, the coloring material is likely to adhere to the inside of the ink holding section 5, so that the coloring material supply ability is greatly increased when the power is turned on again. However, there is a problem of deterioration of the reliability of the device.

[0022]

As described above,
In the conventional ink jet recording apparatus, in the method of ejecting ink droplets by the force of an electric field, an auxiliary electrode 13 is provided in addition to the recording electrode 1a in order to maintain the ejection continuity of the ink droplets, and an auxiliary electrode 13 is provided from the ink holding unit 5. Since the colorant is configured to be controlled to flow in and out, when the colorant concentration inside the ink holding section 5 rises, the colorant tends to adhere to the inside of the ink holding section 5. Therefore, there is a problem that there is a high possibility that the supply of the coloring material will be hindered. On the other hand, when the power of the apparatus is turned off, there is a high possibility that the coloring material will adhere inside the ink holding portion 5, and the ink supply capacity will be insufficient at the time of restarting.

The present invention solves the problems of the prior art as described above, and even when the coloring material is collected inside the ink holding portion, the coloring material is applied to the electrode inside the ink holding portion or the insulator near the electrode. It is possible to provide an ink jet recording apparatus that does not adhere to the ink and optimizes the state of the ink when the power is turned on again even if the power is turned off and left for a long time. To aim.

[0024]

To achieve the above object, an ink holding means for holding an ink in which a colorant component is dispersed in an insulating solvent, and a color in the ink held by the ink holding means A recording electrode that causes an agent component to fly by an electrostatic force, a plurality of stirring electrodes that are arranged in at least one location in the vicinity of the recording electrode, and the level relationship of the potential are reversed at regular intervals between the stirring electrodes. The stirring control means controls the average voltage applied to the stirring electrode to be higher than the average voltage applied to the recording electrode when the coloring agent component is supplied onto the recording electrode. The ink jet recording apparatus, further comprising: the agitation control unit that controls the voltage to be lower than an average voltage applied to the recording electrode when it is removed from the recording electrode. To provide.

Further, according to the present invention, the ink holding means for holding the ink in which the coloring agent component is dispersed in the insulating solvent and the coloring agent component in the ink held by the ink holding means are ejected by electrostatic force. A recording electrode that is disposed close to the recording electrode and that stirs the ink, and is controlled based on the output of the concentration detecting unit of the colorant component of the ink inside the ink holding unit; An inkjet recording device is provided, which comprises:

Further, according to the present invention, the ink holding means for holding the ink in which the colorant component is dispersed in the insulating solvent and the colorant component in the ink held by the ink holding means are ejected by electrostatic force. A recording electrode, a transport electrode for transporting the colorant component of the ink in the ink holding means in the supply direction and the recovery direction, and a plurality of agitating electrodes arranged in at least one location close to the recording electrode And an agitation control unit for inverting the potential relationship between the agitation electrodes at regular intervals, wherein an average voltage applied to the agitation electrodes is supplied when the color component is supplied onto the recording electrodes. The voltage is controlled to be higher than the average voltage applied to the transport electrode, and when the colorant component is removed from the recording electrode, the voltage is controlled to be lower than the average voltage applied to the transport electrode. Characterized in that it comprises a stirring means for the, to provide an ink jet recording apparatus. Furthermore, the present invention provides an ink holding means for holding ink in which a colorant component is dispersed in an insulating solvent, and a recording electrode for flying the colorant component in the ink held by the ink holding means by electrostatic force. A transport electrode for transporting the colorant component of the ink in the ink holding means in the supply direction and the recovery direction, and the colorant component of the ink is disposed at at least one position in proximity to the recording electrode. An ink jet recording apparatus is provided, which comprises a stirring means for stirring, the stirring means being controlled based on the output of the concentration detecting means of the color component of the ink inside the ink holding means. Furthermore, the present invention provides an ink holding means for holding ink in which a colorant component is dispersed in an insulating solvent, and a recording electrode for flying the colorant component in the ink held by the ink holding means by electrostatic force. And a common transport / stirring unit having a region of an electrode group for transporting the colorant component of the ink in the ink holding unit in the supply direction and the recovery direction and a region of an electrode group for stirring the colorant component of the ink. An inkjet recording device is provided.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the embodiments of the present invention with reference to the drawings, the present invention will be schematically described.

In the ink jet recording apparatus of the present invention, at least the ink is used in a configuration in which the liquid ink in which the colorant component is dispersed in the insulating solvent is used to fly the colorant component in the liquid ink by electrostatic force. The ink holding section for holding the ink and the stirring means for stirring the ink provided inside the ink holding section or in the vicinity of the ink holding section stir the ink as necessary to keep the ink state in good condition. Configure to keep on. In particular,
When the agitating means is an agitating electrode, ink is agitated by an electric field by applying a voltage to the set of agitating electrodes so as to generate a potential difference that reverses the level relation of the potential at regular intervals. To do.

As a result, by forming a state in which the liquid ink always moves, it is possible to stir the liquid ink and prevent the coloring agent from adhering.

An ultrasonic wave generator may be used instead of the stirring electrode to stir the ink. In this case, the ink can be stirred without directly contacting the ink.

These stirring electrodes and ultrasonic wave generating means can be provided at a plurality of locations. As a result, it becomes possible to prevent the color material from adhering to the entire apparatus.

In the structure including the stirring electrode, when the stirring electrode is provided adjacent to the recording electrode for ejecting ink droplets, the average voltage of the stirring electrode is higher than the average voltage of the recording voltage when the ink is supplied. At the time of ink recovery, driving is performed so as to be lower than the average voltage of the recording electrodes. In this way, the movement of the coloring material in the ink can be controlled by controlling the potential relationship between the stirring electrode and the recording electrode.

In the structure including the stirring electrode, when the recording electrode for ejecting ink droplets and the ink transport electrode for transporting ink near the recording electrode are provided, the stirring electrode is adjacent to the ink transport electrode. When the electrodes are provided, the stirring electrode is driven so that the average voltage of the stirring electrode is higher than the average voltage of the ink transport electrode when the ink is supplied, and lower than the average voltage of the ink transport electrode when the ink is collected. In this way, when controlling the potential relationship between the stirring electrode and the transport electrode, not only the movement of the coloring material in the ink can be controlled, but also the movement of the coloring material by the transportation electrode is not hindered.

The ink carrying electrode and the stirring electrode may be constituted by a common electrode. In this case, the structure is such that one part of the common electrode is driven so as to carry the transport action and the other part is driven so as to perform the stirring action, and the action boundary, that is, the combination of actions can be freely changed. . As a result, it is not necessary to provide a special stirring electrode for stirring the ink.

In a structure having at least a stirring electrode provided to stir the ink or a stirring means by an ultrasonic wave generating means, a concentration detecting means is installed in the vicinity of the stirring means, and stirring is performed based on the information from the concentration detecting means. The control signal to the means may be adjusted.

The density detecting means may be provided at a plurality of places.

As described above, by providing the density detecting means, it is possible to verify the presence or absence of the coloring material adhered or the effect of the stirring action by observing the actual state of the coloring material. Since it can be fed back to the control of, reliable and reliable adhesion prevention can be performed. Further, by providing a plurality of concentration detecting means, it becomes possible to further improve reliability.

The density detecting means is composed of a light emitting part and a light receiving part, and part or all of the ink holding part is made to be light transmissive. You may make it detect the density of ink based on this. Further, part or all of the stirring means may be made light-transmitting, and the density detecting means may detect the density of the ink based on the light transmittance through the stirring means.

On the other hand, the concentration detecting means may be composed of a plurality of electrodes and resistance measuring means for measuring the resistance value between the electrodes. In this case, it is not necessary to provide a particularly large space for detecting the density. Furthermore, the electrode for stirring the ink and the electrode for detecting the concentration can be configured by the same electrode, and in this case, there is no need to provide an electrode for detecting the concentration. is there.

Embodiments of the present invention will be described below with reference to the drawings. Example 1. 1 is a schematic configuration diagram of an inkjet recording apparatus according to a first embodiment of the present invention.

As shown in the figure, the recording head includes a head substrate 1b on which recording electrodes 1a for ejecting ink droplets 4a are arranged, and an upper substrate 2 provided above and facing the substrate.
a and a lower substrate 2b provided to face downward. A control circuit 50 connected to a recording power supply 51 is connected to the recording electrode 1a.

An ink holding portion 5 is formed between the upper substrate 2a and the head substrate 1b, and between the lower substrate 2b and the head substrate 1b, and the ink 4 can freely move in the ink holding portion 5. It is kept movable. For this reason, the upper substrate 2a and the lower substrate 2b are both arranged via a spacer of about 500 μm from the head substrate 1.

A plurality of agitating electrodes 3 for agitating the coloring material in the ink holding portion 5 are formed on the surface of the upper substrate 2a which is in contact with the ink 4, and the agitating electrode connected to the agitating power source 61. The control circuit 60 is connected.

In the ink 4 filled in the recording head, a positively chargeable colorant containing a charge control agent and a binder is colloidally dispersed in an insulating solvent having a resistivity of 10 ⁸ Ωcm or more and suspended. It has a positive potential.

The ink 4 is once filled in the ink holding portion 5 through the ink supply passage 7a and then is supplied to the tip of the head, and the slit-shaped opening 6 has a meniscus shape as shown in FIG. The ink 4 around here is the stirring electrode 3
Due to the action, the colorant is concentrated during the recording operation, and the colorant concentration increases.

At the head of the head, the ink droplet 4a having a higher colorant concentration is ejected, and the ink 4 which has not contributed to the ejection wraps around the head end of the head and is discharged between the head substrate 1b and the lower substrate 2b. It enters into the ink recovery flow path 7b formed in the head and flows to the ink recirculation mechanism 8 connected to the head.

Since the colorant density of the ink 4 in the ink recovery flow path 7b is relatively low, the colorant density is adjusted by the ink density adjusting section 9 including the ink tank provided in the ink recirculation mechanism 8. Optimize. In addition, a pump 10 is provided in the ink recirculation mechanism 8 in order to optimize the state of the meniscus in the opening 6 and control the overall flow of the ink 4.

The recording drum 1 which is grounded is provided in front of the head.
1 are opposed to each other with a gap of 500 μm or less, and a recording medium 12 for recording image points is wound around the surface.

FIG. 2 is an enlarged perspective view showing the tip of the ink jet head.

As shown in the figure, the head substrate 1b
Is formed of a material having a low dielectric constant and high strength, such as polyimide, glass epoxy resin, phenol resin, and Teflon, having a thickness of about 50 μm, and a rectangular surface made of Cu having a thickness of about 18 μm on its surface. The recording electrodes 1a having a shape are formed in a stripe shape. The back surface of the upper substrate 2a is also made of the same material as that of the head substrate 1b, and rectangular stirring electrodes 3 made of Cu and having a thickness of about 18 μm are formed in stripes on the front surface. The head substrate 1b protrudes from the tip of the upper substrate 2a by about 1 mm, and the thickness of the ink 4 at the tip of the head substrate 1b can be set thin.

The operation of the configuration described above will be described below.

First, the control circuit 50 applies a drive waveform as shown in the explanatory view of FIG. 3 to the recording electrode 1a of the head substrate 1b. That is, the plurality of recording electrodes 1a
Is divided into two systems, an even number and an odd number, and 1.
A DC bias from the recording power source 51 of about 4 kV and continuous pulses 52a and 52b whose phases are shifted by a half cycle are superimposed and applied. When such a waveform is applied, a potential gradient in which the direction is reversed is generated between the adjacent electrodes at regular intervals, and the coloring material always moves in the direction in which the potential is low. The coloring material reciprocates between the recording electrodes 1a and is constantly stirred. When the pulse signal 53 based on the image signal is applied to the recording electrode 1a at the moment when the potential becomes low, the ink droplet 4a is ejected.

On the other hand, the stirring electrode 3 is applied with a drive waveform as shown in the explanatory view of FIG. 4 to the stirring electrode 3. That is, the plurality of stirring electrodes 3 are divided into two systems of even number and odd number, and a DC bias from the stirring power source 61 and continuous pulses 62a and 62b whose phases are shifted from each other by a half cycle are superposed on each other. When such a waveform is applied, a potential gradient in which the direction is reversed at regular intervals is generated between the adjacent electrodes, and the coloring agent always moves in the direction in which the potential is low. In the meantime, the coloring agent moves back and forth and is constantly stirred.

During the recording operation, it is necessary to supply the coloring material in the ink 4 onto the recording electrode 1a.
Is set higher than the average voltage of the recording electrode 1a. For example, the DC bias of the recording electrode 1a is Vpb,
The amplitude of the continuous pulse 52a, 52b is Vpp, the stirring electrode 3
When the direct current bias to Vsb is set to Vsb, if the relation of Vsb ≧ Vpb + Vpp (1) is satisfied, it is possible to reliably supply the color material.

On the contrary, when the recording material is at rest or when the coloring material attached to the recording electrode 1a is to be removed, the average voltage of the recording electrode 1a is set lower than the average voltage of the stirring electrode 3.
For example, when the amplitude of the continuous pulses 62a and 62b of the stirring electrode 3 is Vsp, the operation is performed so that the relationship of Vpb ≧ Vsb + Vsp (2) holds. When the relationship of the average voltage is reversed, the coloring material in the ink moves in the direction of the ink holding portion 5, so the coloring material becomes thin at the head tip,
Components other than the colorant, for example, an insulating solvent are mainly retained. That is, the coloring agent is less likely to adhere to the tip of the head. On the contrary, in the ink holding portion 5, the coloring material concentration is increased, but since the coloring material is constantly moved between the electrodes by the stirring electrode 3 and is stirred, the possibility that the coloring material adheres is reduced. .

Regarding the voltage setting, the above (1)
However, the DC bias of the stirring electrode 3 and the amplitude or duty ratio of the continuous pulses 62a and 62b may be adjusted in consideration of the height difference in the average voltage.

As described above, by disposing the stirring electrode 3 for stirring the coloring agent of the ink 4 in the ink holding section 5, the coloring agent is particularly collected and the coloring agent concentration of the ink holding section 5 is increased. Even in this case, it is possible to prevent the coloring agent from adhering to the ink holding portion 5.

When the agitating electrode 3 is provided in the vicinity of the recording electrode 1a, the colorant density at the tip of the head can be controlled by controlling the potential relationship between the agitating electrode 3 and the recording electrode 1a. Therefore, it becomes possible to smoothly supply the coloring material.

The agitating electrode 3 of this embodiment has an ink holding portion 5.
Since the plurality of colorants are mixed for the purpose of stirring, it is not always necessary to match the pitch, the number, etc. of the stirring electrodes 3 with the recording electrode 1a, and the direction of electrode formation also does not match with the recording electrode 1a. , As shown in the plan view of FIG.
Even if the stirring electrodes 3 are arranged in an oblique direction or in a certain curved shape as shown in the plan view of FIG. 6, a plurality of stirring electrodes 3 should be formed at a certain distance along the extending direction of the electrodes. If so, the same effect can be obtained.

Although the stirring electrode 3 is formed on the surface of the upper substrate 2a on the ink 4 side in the first embodiment, it may be arranged on the outer surface as shown in the partial perspective view of FIG. In this way, since the ink 4 and the stirring electrode 3 do not come into contact with each other, it is possible to prevent the coloring agent of the ink 4 from adhering to the stirring electrode 3. However, in this case, since the electric field is applied to the coloring material through the thickness of the upper substrate 2a, the influence of the electric field is reduced. Therefore, the upper substrate 2
It is necessary to suppress the thickness of a to about 50 μm or less so that the electric field can be sufficiently acted.

If the upper substrate 2a is made thin, the mechanical strength of the upper substrate 2a may decrease. However, a material having high strength is used, or as shown in the partial perspective view of FIG. By disposing another reinforcing member 2c on the stirring electrode 3, it is possible to compensate for the lack of strength.

Incidentally, the upper substrate 2a may be made of a hard material such as Si in addition to the material usually used for the flexible substrate. For example, when Si is used as the substrate, since the stirring electrode 3 can be formed in a thin film, the number of grooves and steps formed by the electrode is reduced, and the coloring agent is less likely to adhere. Further, there is an advantage that it is possible to easily form an arbitrary electrode pattern and to secure mechanical strength because it is a hard material.

In the explanatory view of FIG. 4, a continuous pulse 62a is applied to the stirring electrode 3 for the DC bias from the stirring power source 61,
Although the case where a signal in which 62b is superimposed is given is illustrated,
Even if a sine wave is given instead of the continuous pulses 62a and 62b, the stirring effect does not change, and the intended purpose can be achieved.

The ink stirring means of this embodiment may be installed in a plurality of places as long as the ink 4 is present. For example, in an ink tank for replenishing the ink 4, or an ink supply path 7a serving as a flow path of the ink 4,
The inside of the ink recovery channel 7b may be considered.

In particular, when the apparatus is left for a long time, the adhesion of the coloring material is likely to occur, but when the recording operation is restarted,
When the stirring operation is performed at a plurality of points, it is possible to quickly restore the ink 4 to the normal state as the entire device. Example 2. FIG. 9 is a partially enlarged sectional view of an ink jet recording apparatus according to a second embodiment of the present invention, and particularly shows an enlarged head tip portion.

As shown in the figure, a piezoelectric body 22 is arranged above the recording head, an ultrasonic wave generating individual electrode 23 is arranged on the upper surface thereof, and an ultrasonic wave generating common electrode 21 is arranged on the lower surface thereof. Will be placed. Ultrasonic wave generation common electrode 21
A sound wave interference layer 20 is interposed between the ink holding section 5 and the ink holding section 5.
The sound wave interference layer 20 is a substance that also serves as an acoustic matching layer between the piezoelectric body 22 and the ink 4, and is made of, for example, glass.

The piezoelectric body 22 is formed on the entire surface or in a band shape by means of controlling the thickness of a material such as ZnO or PLZT by sputtering, and the ultrasonic wave generating individual electrode 23 and the ultrasonic wave generating common electrode are formed on the upper and lower surfaces thereof. Two
1 is formed. These ultrasonic wave generation individual electrodes 23
The ultrasonic wave generation common electrode 21 is connected to an ultrasonic wave generation circuit 24 which is supplied with a bias voltage from a DC power supply 25.

The operation of the above-described structure will be described below.

At the time of ultrasonic wave generation, the ultrasonic wave generating common electrode 2
1 and the ultrasonic generating individual electrode 23, the frequency is several MHz
A drive signal having a voltage of several tens of V to several hundreds of V is applied at a frequency of up to several hundred MHz. As a result, ultrasonic waves are generated in the ultrasonic wave generation common electrode 21 and act on the ink 4 inside the ink holding portion 5 through the sound wave interference layer 20, so that the coloring agent is agitated and the adhesion of the coloring agent can be prevented. .

The ultrasonic wave generating common electrode 21 needs to be applied with a voltage in consideration of the relationship with the voltage value of the recording electrode 1a in order to form an electric field which influences the movement of the coloring material with the recording electrode 1a. There is. That is, the voltage of the ultrasonic wave generation common electrode 21 is set to be higher than the average voltage of the recording electrode 1a when the coloring material is supplied, and the voltage of the ultrasonic wave generation common electrode 21 is set to be lower than the average voltage of the recording electrode 1a when collecting the color material. There is a need to. Therefore, it is necessary to supply a DC bias from the DC power supply 25 to both the ultrasonic wave generation common electrode 21 and the ultrasonic wave generation individual electrode 23. In this case, when the direct current bias to the ultrasonic wave generation common electrode 21 is Vub, the potential relationship is Vub ≧ Vpb + Vpp (3) when the color material is supplied, and Vub ≦ Vpb (4) when the color material is collected. Need to be adjusted to meet. As a result, it is possible to reliably control the moving direction of the color material. The method of setting the voltage is not limited to the relationship of the expressions (3) and (4), and it goes without saying that the voltage can be adjusted in consideration of the height difference in the average voltage.

When ultrasonic waves are used as the ink stirring means as in this embodiment, the ultrasonic wave generation common electrode 21 and the ultrasonic wave generation individual electrode 2 which are electrodes for ultrasonic wave generation are used.
Since ultrasonic waves can act on the ink 4 without bringing the ink 3 into contact with the ink 4, the ink 4 can be efficiently stirred without concern about the adhesion of the coloring material to the electrodes.

Further, since the structural material formed by the sound wave interference layer 20, the ultrasonic wave generation common electrode 21, the piezoelectric body 22, and the ultrasonic wave generation individual electrode 23 is placed on the upper lid of the ink holding portion 5, mechanical strength is improved. Can be increased.

In the embodiment of FIG. 9, one piezoelectric body 22 is used as the ultrasonic wave generating means and the ultrasonic wave generating individual electrode 23 is used.
Although the configuration in which the piezoelectric element 22 is driven by is illustrated as an example, as shown in the partially enlarged cross-sectional view of FIG. 10, by using the individually divided piezoelectric bodies 22, stirring in each region can be performed more reliably and finely. become able to.

The ultrasonic wave generating means of this embodiment may be installed at a plurality of places as long as the ink 4 exists. For example, in an ink tank for replenishing the ink 4, or an ink supply path 7a serving as a flow path of the ink 4,
The inside of the ink recovery channel 7b may be considered.

In particular, when the apparatus is left for a long time, the adhesion of the coloring material is likely to occur, but when the recording operation is restarted,
When the stirring operation is performed at a plurality of points, it is possible to quickly restore the ink 4 to the normal state as the entire device.

As described above, according to the ink jet recording apparatus of this embodiment, since the ultrasonic wave is used as the stirring means, it is possible to exert a sufficient stirring action without bringing the stirring source into contact with the ink. Therefore, there is no adhesion of the coloring agent to the electrodes, and there is an effect that the strength can be increased.

Further, the ultrasonic wave generation source can be provided at a plurality of positions in the head, and can maintain the ink state in a good condition as a whole, especially when the apparatus is left for a long time. Even in the case, the ink can be quickly returned to the normal state. Example 3. FIG. 11 is a partially enlarged cross-sectional view of an ink jet recording apparatus according to a third embodiment of the present invention, particularly an enlarged view of a head tip portion.

As shown in the figure, an electrode array 30 for carrying the ink 4 is provided on the ink side surface of the upper substrate 2a, and is formed in a stripe shape orthogonal to the recording electrodes 1a. . A transport driver circuit 31 is connected to the electrode array 30, and a DC bias is supplied to the transport driver circuit 31 from a DC power supply 32. The stirring electrode 3 for stirring the ink 4 is the electrode array 3
It is provided adjacent to 0, and is formed here in a stripe shape parallel to the recording electrode 1a.

The operation of the configuration described above will be described below.

For the electrode groups 30a to 30e forming the electrode array 30 for ink conveyance, a DC bias is applied from the DC power source 32, and the voltage application position is moved with time as shown in the waveform diagram of FIG. The phase-shift-controlled three-phase voltage pulse trains φ1, φ2, and φ3 are supplied by the carrier driver circuit 31.

Here, when the ink 4 is supplied to the tip of the head, the average voltage of the electrode array 30 is set higher than the average voltage of the recording electrode 1a so that the electric field acts in the head tip direction. As shown in FIG. 12, the phase of the pulse is adjusted so that the coloring agent inside moves toward the tip of the head.
shift. Further, for the stirring electrode 3 provided close to the electrode array 30, a value equal to or higher than the average voltage of the electrode array 30 is set as the average voltage. This is to prevent the colorant transport by the electrode array 30 from being disturbed.

Now, assuming that the DC bias to the electrode array 30 is Vcb and the pulse amplitude is Vcp, for example, Vpb + Vpp≤Vcb (5) Vcb + Vcp≤Vsb (6). Can be done. On the other hand, the method of supplying the pulse voltage to the stirring electrode 3 is the same as that in the first embodiment, and the stirring operation is performed in a state where the potential difference between the adjacent electrodes is always reversed.

When the coloring material in the ink 4 is supplied to the tip of the head, the driving may be performed so that the relationship of the average voltage is: recording electrode 1a <electrode array 30 ≦ stirring electrode 3, and the condition is ( 5) formula,
It is not limited to the equation (6).

On the other hand, when the color material is collected in the ink holding portion 5, the driving operation is exactly the same as that for supplying the color material. That is, the electrode groups 30a to 30e are driven so as to shift the phase relationship of the pulses shown in FIG. 12 in the opposite direction, and the relationship of the average voltage is as follows: recording electrode 1a> electrode array 30 ≧ stirring electrode 3 Set. As a result, in the ink holding unit 5, an electric field can be applied in a direction away from the tip of the head, and smooth colorant recovery can be performed.

By the way, when the ink transporting means is provided near the tip of the head, the colorant can be moved in one direction in the ink holding portion 5, but the movement is continued especially when the colorant is collected. If this is done, the coloring material will just move away from the tip of the head, and if the coloring material is to be supplied next time, the coloring material supply distance will be long, and the recording start time will be delayed accordingly. In addition, there is a high possibility that the coloring material will adhere to the moving destination. On the other hand, when the stirring electrode 3 is provided in the vicinity of the electrode array 30 as in the present embodiment, the coloring agent conveyed by the electrode array 30 is retained at the position of the stirring electrode 3, so that the next time. We can quickly respond to supply,
Further, since the coloring agent is constantly stirred, there is no concern that it will adhere to the electrodes. In addition, the driving method described above can be adapted so as not to obstruct the moving direction of the coloring material but to accelerate it in the opposite direction.

In the description of this embodiment, the case where the stirring electrode 3 is used for stirring the ink has been mainly described.
Needless to say, even if the ink agitation is replaced by an ultrasonic wave generation means, the same applies. That is, the same control can be performed by merely replacing the relationship between the electrode array 30 and the stirring electrode 3 with the relationship between the electrode array 30 and the ultrasonic wave generation common electrode 21.

As described above, according to the present embodiment, the stirring means is provided adjacent to the ink carrying means, so that the ink carrying position can be determined and the adhesion of the coloring material at the carrying destination can be prevented. The effect is that you can do it. Example 4. FIG. 13 is a partially enlarged cross-sectional view of the ink jet recording apparatus according to the fourth embodiment of the present invention, particularly an enlarged view of the head tip portion.

As shown in the figure, the ink 4 on the upper substrate 2a
On the surface on the side, a plurality of function-sharing electrodes 40, which share the function of the ink-carrying electrodes and the function of the stirring electrode, are formed in stripes orthogonal to the recording electrodes 1a. These function-sharing electrodes 40 are controlled by a function-sharing electrode control circuit 41 which receives a DC bias from a DC power supply 42.

In the case of FIG. 13, one of the function-sharing electrodes 40 in the ink transport region 43a is the transport electrode group 40.
a-40e, and those in the ink agitation region 43b are assigned as agitation electrode groups 40f-40i. Of course, the function boundary area 43c, which is the boundary between the ink transport area 43a and the ink stirring area 43b, can be arbitrarily moved by the function-sharing electrode control circuit 41.

As described above, the function-sharing electrode 40 is
In the ink transport area 43a assigned as the transport electrode groups 40a to 40e, the ink 4 in the ink holding unit 5 is driven to be supplied or recovered by the driving method shown in FIG.

On the other hand, the function-sharing electrode 40 is assigned to the ink stirring area 4 assigned as the stirring electrode groups 40f to 40i.
In 3b, the ink 4 in the ink holding portion 5 is agitated by the driving method as shown in FIG.

The potential relationship between the electrodes of the ink transport area 43a and the ink agitation area 43b is basically the same as that of the third embodiment, but a DC bias is applied to the DC power supply 42.
Therefore, the function-sharing electrode control circuit 41 actually operates by adjusting the amplitude of each pulse.

The functional boundary area 43c that defines the boundary between the ink transport area 43a and the ink stirring area 43b is changed as follows.

For example, in the case of color material recovery, 1
When a short pause is performed until the recording of the next sheet is completed after the recording of the sheet, as shown in FIG. 14A, the functional boundary area 43c is moved to a position near the tip of the head. As a result, since the ink transport area 43a is narrowed, the moving distance of the coloring material for collecting the coloring material is short, and the time until the coloring material is supplied at the time of recording of the next sheet is shortened, and immediate action is taken. It is possible to

On the other hand, in the case of long-term rest, FIG.
As shown in (b), the functional boundary region 43c is moved to a position far from the head tip to widen the ink transport region 43a to a sufficiently wide range. As a result, the ink transport region 43a can be sufficiently taken, so that the coloring material can be collected up to a position far away from the head tip, and the coloring material can be effectively prevented from adhering to the head tip.

As described above, the function-sharing electrode 40 is divided into the ink carrying area 43a and the ink stirring area 43b, and the carrying electrode groups 40a to 40e and the stirring electrode group 40f are respectively divided.
By assigning ˜40i, not only the manufacturing is facilitated, but also an arbitrary function can be assigned to an arbitrary electrode depending on the control method by the function-sharing electrode control circuit 41. It is possible to apply the corresponding optimum control, improve the flexibility of the apparatus, and realize an efficient and highly reliable inkjet recording apparatus.

As described above, according to this embodiment, when the electric field is used as the stirring means, the ink transport function and the stirring function can be realized by the common electrode. Therefore, by arbitrarily changing the boundary between the transport function portion and the stirring function portion, there is an effect that control according to the situation becomes possible. Example 5. FIG. 15 is a partially enlarged sectional view of an ink jet recording apparatus according to a fifth embodiment of the present invention, particularly an enlarged view of the head tip end portion as viewed from the front.

As shown in the figure, the upper substrate 2a is
The optical density detection unit 70 is made of a light-transmissive material, such as glass, and has a light emitting element and a light receiving element disposed thereon. The optical density detection unit 70 is connected to the stirring electrode control circuit 60 for controlling the stirring electrode 3.

In the structure as described above, the light emitted from the optical density detecting section 70 passes through the upper substrate 2a, is introduced into the ink holding section 5, and is guided into the ink 4 as incident light 71a. Incident light 71a is then transmitted to the head substrate 1
is reflected by b and returns in the ink 4 as reflected light 71b,
It again passes through the upper substrate 2a and enters the optical density detection unit 70.

The coloring material is easily attached between the stirring electrodes 3 on the upper substrate 2a, and is easily attached between the recording electrodes 1a on the head substrate 1b. As a result, when the coloring material is attached, the light transmittance of the upper substrate 2a is significantly reduced, and the light reflectance of the head substrate 1b is significantly reduced. That is, the optical density detection unit 70 determines the degree of colorant adhesion by the reflected light 71.
It can be detected by the intensity of b. By feeding back the detection result to the stirring electrode control circuit 60, it becomes possible to carry out stirring control according to the situation inside the ink holding unit 5.

For example, the stirring operation by the stirring electrode 3 is basically performed to prevent the adhesion of the coloring material, and it is not necessary to function it unless the coloring material is adhered. Therefore, the state inside the ink holding unit 5 is detected by the optical density detection unit 70 at predetermined predetermined time intervals or after recording a predetermined number of sheets, or immediately after the recording is started after being left for a long time, and the coloring agent is attached. Only when it is determined that
If the stirring electrode control circuit 60 supplies a pulse to the stirring electrode 3, the load on the stirring electrode control circuit 60 can be reduced.

Further, the optical density detecting section 70 is provided with the reflected light 71.
Since the state of the adherence of the coloring material can be detected by the intensity of b, the stirring electrode control circuit 60 can perform optimum stirring control based on the detection signal from the optical density detection unit 70.

In other words, when the stirring control states of the stirring electrode 3 are the same, for example, when the stirring electrode 3 is controlled with the bias voltage, the pulse width, the pulse amplitude and the like kept constant, it is possible to adapt to various adhesion states of the coloring material. Not necessarily. On the other hand, the state of stirring control can be changed in various ways, such as the relationship of the bias potential with the recording electrode 1a and other control electrodes, the combination of functions, and the like. It is possible to create an optimal control situation.

Therefore, the parameters for the stirring operation by the stirring electrode 3 are changed based on the feedback signal from the optical density detection unit 70, and the parameter optimization loop is repeated until the adherence of the coloring material is eliminated. It becomes possible to perform an effective stirring operation.

For example, the control is such that, while gradually increasing the potential difference between the stirring electrodes 3, the adhering state of the coloring material is monitored and the optimum value is found. FIG. 16 shows a flowchart of such control operation.

First, when the density detection signal from the stirring electrode control circuit 60 is given to the optical density detection section 70, the optical density detection section 70 operates to emit light into the ink holding section 5 and the intensity of the reflected light. , That is, reflectance R measurement (step S
1) is performed. The reflectance R is calculated by the stirring electrode control circuit 60.
Be fed back to.

The stirring electrode control circuit 60 is set with a reflectance threshold value Rth for determining whether or not the coloring material is attached, and it is determined whether the reflectance R is larger than this threshold value Rth (step S2). ) Do. Then, the reflectance R is the threshold value Rt
If it is larger than h, it is determined that there is no adherence of the coloring material, and the process is normally terminated.

On the contrary, when the reflectance R is less than or equal to the threshold value Rth,
It is judged that there is adhesion of coloring material, and a loop for correcting the stirring conditions is entered. In this routine, the voltage difference dV is added to the current potential difference between the stirring electrodes 3, that is, the pulse amplitude V.
Is added. In this case, first, in step S3,
Even if the increase dV is added to the current potential difference V, it is determined whether or not the preset threshold value Vth is exceeded. The threshold voltage Vth in this case is set to the maximum voltage that can be applied between the stirring electrodes 3, but in reality, it is the dielectric breakdown voltage of the air or the insulating material between the electrodes, or the maximum voltage limited by the control circuit. The lower voltage value will be set.

When the newly set voltage V + dV exceeds the threshold value Vth, the potential difference cannot be corrected any more, and therefore the processing is ended and the abnormal end is output to the outside.

On the other hand, the newly set voltage V +
If dV is less than or equal to the threshold value Vth, the voltage V is corrected to the voltage V + dV in step S4, and the stirring electrode 3 is
Control.

While performing the stirring operation under the new condition, the stirring electrode control circuit 60 again sends a density detection signal to the optical density detecting section 70 to check the adhering condition of the color material according to the correction condition. Thereafter, as in the case of the previous routine, if the adherence of the coloring material is eliminated, the process normally ends, and if the adhesion of the coloring material is present, the routine for correcting the stirring condition again is entered.

As described above, the stirring operation can be performed under the optimum stirring condition while observing the adhering condition of the coloring material, so that reliable and highly reliable stirring can be performed. It is needless to say that such feedback control can be applied to any case, whether the stirring operation is always performed or performed as needed.

For example, when stirring is always performed, the stirring electrode control circuit 60 applies a stirring stirring pulse voltage to the stirring electrode 3 so that the stirring operation is always performed, while the optical density detecting section 70 holds the ink. When the ink adheres once, the condition in the section 5 is checked, and the stirring condition is changed to perform the operation for removing the adherence. When the adherence of the coloring material is eliminated, the constant stirring voltage is again applied. The control such as returning to the constant stirring is performed. As a result, it is possible to always perform the stirring operation under the optimal conditions for removing and adhering the coloring material, and highly reliable control is possible.

On the other hand, if necessary, for example,
The inside of the ink holding unit 5 is constantly checked by the optical density detection unit 70, and when adhering of the coloring material is recognized, the stirring electrode control circuit 60 applies an initial voltage pulse to the stirring electrode 3 to cause the stirring operation. , The stirring operation is performed while searching for the optimum conditions until the adhesion of the coloring material is eliminated.

When necessary, such as at regular intervals, at regular intervals of recording, or after recording for a long time before starting recording, the optical density detecting section 70 confirms the internal condition of the ink holding section 5 to check the color. When the adhering of the agent is recognized, the agitating electrode control circuit 60 applies an initial voltage pulse to the agitating electrode 3 to perform the agitating operation, and performs the agitating operation while searching for the optimum condition until the adhering of the colorant is eliminated. You may do it.

Various methods are conceivable for the control form based on the feedback from the optical density detecting section 70. In any case, the control condition is changed according to the actual situation while observing the actual adhesion state of the colorant. Since the stirring operation can be performed while performing the stirring operation, the reliability of the stirring operation can be improved and the state of the ink 4 can be always maintained in a good state.

If the stirring electrode 3 is made of a transparent electrode, not only the degree of freedom can be provided at the installation location of the optical density detector 70, but also the state of adhesion of the coloring material to the stirring electrode 3 itself can be monitored. Further, the reliability can be improved.

Now, in the configuration of FIG. 15, the stirring electrodes 3, 3 are
Incident light 71a is applied from the optical density detection unit 70 to the gap between them, and reflected light 71b is extracted from the same portion,
Although the adhesion state of the coloring material in the portion corresponding to the gap between the stirring electrodes 3 is observed, for example, as shown in the partially enlarged sectional view of FIG. 17, the light emitting portion 70a and the light receiving portion 70b are separated from each other. It may be installed so that the paths of the incident light 71a and the reflected light 71b in the ink holding section 5 are separated. In this case, since the incident light 71a is given from the optical density detection unit 70 to a certain gap between the stirring electrodes 3 and the reflected light 71b is taken out from another gap between the stirring electrodes 3 and 3, the light is the stirring electrode 3. Since it passes through the portion immediately below, it is possible to observe the situation immediately below the stirring electrode 3.

Although the light emitting portion 70a and the light receiving portion 70b are shown separately in FIG. 17, it goes without saying that these may be integrated.

In the present embodiment, the description has been centered on the case where the stirring electrode 3 is used to stir the inside of the ink holding portion 5. However, even if the stirring means is a system using ultrasonic waves, the same applies. Not to mention possible. However, in the case of the method using ultrasonic waves, since a member that blocks light, such as a piezoelectric body, is often used, a special device for securing the optical paths of the incident light 71a and the reflected light 71b from the optical density detection unit 70. However, basically, at the same time as making the electrodes transparent, it is possible to deal with such problems as devising the shape of the piezoelectric body to secure the optical path or providing a light passage hole in the piezoelectric body. is there.

In the present embodiment, the optical density detecting section 70
However, it is possible to install at multiple locations, and the colorant stirring state can be individually observed for each part, so it is possible to operate only the stirring means of a specific part or control the conditions. It becomes possible. In this case, it is possible to prevent the trouble caused by applying the change of the stirring condition that is applied to only a part to the whole.

As described above, according to the present embodiment, the concentration detecting means by an optical method is provided adjacent to the stirring means, and the stirring means can be controlled in accordance with this, so that the stirring means can be controlled. While observing the agitating state of the coloring material in the ink holding part, the observation result is fed back to the agitation control so that the ink inside the ink holding part can always be in a good state, and it can be adjusted according to the state of the device. The effect is that optimal stirring control can be realized. Also, by providing the optical density detection means at multiple locations, it is possible to observe the agitation state of the ink even in a wide range, and it becomes possible to control the agitation under optimum agitation conditions at each location, so that the total performance of the device can be maintained. effective. Further, if a transparent electrode is used for each electrode, the applicable range of optical density detection is widened and the performance can be further improved. Example 6. FIG. 18 is a partial plan view of an ink jet recording apparatus according to a sixth embodiment of the present invention, and is an enlarged view of a head tip end portion as seen from above.

As shown in the figure, a pair of concentration detection electrodes 80 are provided on the ink side surface of the upper substrate 2a in proximity to the stirring electrode 3. The concentration detecting electrode 80 is connected to a resistance measuring circuit 81 for measuring the resistance value between the electrodes. Then, the resistance measuring circuit 81 is connected to the stirring electrode control circuit 60.

In the structure as described above, the density detecting electrode 80 has a function of detecting the colorant density of the ink inside the ink holding portion 5 from its resistance value, and the detection status is fed back to the stirring electrode control circuit 60. Then, the stirring operation is controlled.

Some inks used in the ink holding section 5 have a solvent volume resistivity of about 10 ⁸ Ωcm and a colorant component volume resistivity of about 10 ¹³ Ωcm. When such an ink is used, the resistance value of the ink increases when the density of the coloring material is high, and conversely, the resistance value of the ink decreases when the density of the coloring material is low. Therefore, in a situation where the coloring agent is attached, it is more than in a situation where the coloring agent is not attached.
Since the resistance value of the ink rises, it is possible to confirm the adhesion state based on the resistance value of the ink.

On the contrary, in the case of using the ink in which the coloring material is easily adhered when the resistance value of the ink is lowered,
It is sufficient to detect that the resistance value of the ink has dropped and stir the ink.

That is, by detecting the resistance value between the concentration detecting electrodes 80 by the resistance measuring circuit 81, it is possible to confirm the state of stirring action, and it is possible to feed back the stirring control by the stirring electrode control circuit 60. it can.

Note that how the signal from the resistance measuring circuit 81 is applied to the control in the stirring electrode control circuit 60 is exactly the same as in the case of the fifth embodiment, and the same effect can be obtained. is there.

Incidentally, as in the present embodiment, the concentration detection electrode 80
In the method of measuring the density of the ink by the resistance measuring circuit 81 and the resistance measuring circuit 81, a space is not required and the degree of freedom of the installation location of the density detecting electrode 80 is high, as compared with the case of using light.
Not only is it suitable for downsizing of the device, but also the degree of freedom in design can be increased. Further, in the case of the method of using the stirring electrode 3 as the stirring means, a method of configuring the stirring electrode 3 and the concentration detection electrode 80 with a common electrode and switching and using them is also applicable. In this case, there is no need to secure a separate space for density detection, and the density detection position can be set arbitrarily, so that the degree of freedom in control can be greatly improved.

In this embodiment, the change in the concentration is detected from the change in the resistance value, but the same effect can be expected by catching the change in the capacitance. The device configuration in this case may be basically the same as that of FIG. 18, and can be realized by replacing the resistance measuring circuit in the figure with a capacitance measuring circuit.
Since there is a highly accurate measurement of capacitance, more accurate information about ink density can be obtained.

As described above, according to this embodiment, the pair of concentration detecting electrodes 80 are used as the concentration detecting means,
Since the stirring state can be detected by the resistance value between each electrode, it is possible to accurately detect the state of the ink without increasing the size of the device. Particularly, by sharing it with the electrode for stirring, the structure can be further improved. There is an effect that the structure can be simplified and the structure can be made extremely advantageous in design and manufacturing. Further, since the concentration can be detected at an arbitrary place, there is an effect that the controllability of stirring can be greatly improved.

Although the ink jet recording apparatus of the present invention has been described above with reference to Examples 1 to 6, each Example may be applied individually or in combination. Of course good things.

[0133]

As described above, according to the present invention, in the ink jet recording apparatus, the ink holding portion is configured to appropriately stir the ink, so that the coloring agent in the ink adheres to each portion in the head. Can be prevented, highly reliable ink management can be performed, non-ejection and ejection failure can be prevented, and the time until ejection in the initial operation can be shortened, so that there is an effect that a stable recording operation can be realized.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an inkjet recording apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a head tip portion of the inkjet recording apparatus according to the first embodiment.

FIG. 3 is an explanatory diagram of a control operation of the recording electrode of FIG.

FIG. 4 is an explanatory diagram of a control operation of the stirring electrode of FIG.

FIG. 5 is a plan view for explaining a modified example 1 of the arrangement of stirring electrodes in the first embodiment.

FIG. 6 is a plan view illustrating a second modification of the arrangement of the stirring electrodes in the first embodiment.

FIG. 7 is a perspective view for explaining a third modification of the arrangement of stirring electrodes in the first embodiment.

FIG. 8 is a perspective view illustrating a modified example 4 of the arrangement of the stirring electrodes in the first embodiment.

FIG. 9 is a partially enlarged cross-sectional view of an inkjet recording device according to a second embodiment of the present invention.

FIG. 10 is an enlarged partial cross-sectional view illustrating a modified example of the inkjet recording apparatus according to the second embodiment of the present invention.

FIG. 11 is a partially enlarged cross-sectional view of an inkjet recording device according to a third embodiment of the present invention.

FIG. 12 is a waveform diagram for explaining the control operation of the third embodiment.

FIG. 13 is a partially enlarged cross-sectional view of an inkjet recording device according to a fourth embodiment of the present invention.

FIG. 14 is a partially enlarged cross-sectional view for explaining an example of a control state of the fourth embodiment.

FIG. 15 is a partial enlarged cross-sectional view of an inkjet recording device according to a fifth embodiment of the present invention.

FIG. 16 is a flowchart of a control method applied to the fifth embodiment.

FIG. 17 is a partial enlarged cross-sectional view for explaining a modified example of the fifth embodiment.

FIG. 18 is a partial plan view of the ink jet recording apparatus according to the sixth embodiment of the present invention.

FIG. 19 is a schematic configuration diagram of a conventional inkjet recording apparatus.

[Explanation of symbols]

1 recording head 1a recording electrode 1b head substrate 2a Upper substrate 2b Lower substrate 2c Reinforcement material 3 stirring electrodes 4 ink 5 Ink holding part 6 openings 7a Ink supply path 7b Ink recovery channel 8 Ink circulation mechanism 9 Ink density adjustment section 10 pumps 11 recording drum 12 recording media 13 Auxiliary electrode 14 Power supply for auxiliary electrode 20 Sound wave interference layer 21 Ultrasonic wave generation common electrode 22 Piezoelectric body 23 Ultrasonic wave generation individual electrode 24 Ultrasonic wave generation circuit 25, 32, 42 DC power supply 30 electrode array 31 Transport driver circuit 30a to 30e electrode group 40 function common electrode 40a to 40e Transport electrode group 40f-40i stirring electrode group 41 Function common electrode control circuit 43a Ink transport area 43b Ink stirring area 43c Functional boundary area 50 control circuit 51 Recording power supply 60 Stirring electrode control circuit 61 Power supply for stirring 70 Optical density detector 70a light emitting unit 70b Light receiving part 71a Incident light 71b reflected light 80 Concentration detection electrode 81 Resistance measurement circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazushi Nagato 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Toshiba Research & Development Center Co., Ltd. (72) Inventor Yasushi Hosaka Ko-sachi-ku, Kawasaki, Kanagawa Mukai Toshiba Town 1 Co., Ltd. Toshiba Research and Development Center (72) Inventor Teruo Murakami Komukai Toshiba Town 1 Komukai Toshiba Town, Kawasaki City, Kanagawa (56) Reference JP-A-9-123459 ( JP, A) JP-A 2-178055 (JP, A) JP-A 8-156260 (JP, A) Actual development Sho 58-66951 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41J 2/06 B41J 2/01 B41J 2/125 B41J 2/175

Claims (9)

(57) [Claims] 1. An ink holding means for holding ink in which a colorant component is dispersed in an insulating solvent, and a recording electrode for flying the colorant component in the ink held by the ink holding means by electrostatic force. A plurality of stirring electrodes arranged at least at one location in the vicinity of the recording electrodes, and stirring control means for inverting the potential relationship between the stirring electrodes at regular intervals, wherein the stirring electrodes are An average voltage is applied to supply the color component onto the recording electrode.
That sometimes, the recording is applied to the electrodes higher control than the average voltage, <br/> sometimes remove the color component from on the recording electrode, controlled to be lower than the average voltage applied to the recording electrode An ink jet recording apparatus, comprising: the agitation control means described above. 2. An ink holding means for holding ink in which a colorant component is dispersed in an insulating solvent, and a recording electrode for flying the colorant component in the ink held by the ink holding means by electrostatic force. The ink is disposed close to the recording electrode to agitate the ink, and
Controlled based on the output of the colorant component concentration detection means,
An inkjet recording device comprising: a stirring unit. 3. An ink holding means for holding ink in which a colorant component is dispersed in an insulating solvent, and a recording electrode for flying the colorant component in the ink held by the ink holding means by electrostatic force. , the transport electrodes for transporting the coloring material component in the ink in the ink holding means in the feed direction and the recovery direction, and a plurality of agitating electrodes disposed on at least one position proximate to the recording electrodes, An agitation control unit for inverting the potential level relationship between the agitation electrodes at regular intervals , supplying an average voltage applied to the agitation electrodes to the recording electrode .
That sometimes, the higher control than the average voltage applied to the transport electrodes, <br/> to remove the color component from on the recording electrode sometimes controlled to be lower than the average voltage applied to the transport electrodes An inkjet recording apparatus, comprising: 4. An ink holding means for holding ink in which a colorant component is dispersed in an insulating solvent, and a recording electrode for flying the colorant component in the ink held by the ink holding means by electrostatic force. , the transport electrodes for transporting the coloring material component in the ink in the ink holding means in the feed direction and the recovery direction, in proximity to the recording electrodes are arranged in at least one place,
A stirring means for stirring the color component of the ink ,
An ink jet recording apparatus, comprising: an agitating unit that is controlled based on an output of a concentration detecting unit for the colorant component of the ink inside the ink holding unit. 5. The ink jet recording apparatus according to claim 2, wherein the density detecting means detects the density of the colorant component of the ink based on an optical method. Wherein said concentration detecting means, coloring material formed of the ink
The ink jet recording apparatus according to claim 2, wherein the concentration of the colorant component of the ink is detected based on the resistance of the minute . 7. The ink jet recording apparatus according to claim 6, wherein the density detecting means shares the electrodes arranged in the ink holding means for detecting the resistance of the colorant component of the ink. Recording device. 8. An ink holding means for holding ink in which a colorant component is dispersed in an insulating solvent, and a recording electrode for flying the colorant component in the ink held by the ink holding means by electrostatic force. An area of an electrode group that conveys a colorant component of ink in the ink holding means in a supply direction and a recovery direction, and the ink
An inkjet recording apparatus, comprising: a common conveying / stirring unit having an electrode group region for stirring the coloring material component . 9. The ink jet recording apparatus according to claim 8, wherein the common conveying and stirring means is controlled by arbitrarily switching the conveying area and the stirring area.