JPH09174854A - Image-recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an image-recording apparatus which can surely prevent ink from leaking subsequent to heating. SOLUTION: In this apparatus, an ink 3 is heated by a heating device 2, so that a gas ink 3" is discharged out of a discharge hole. The discharge is intermittently carried out by turning ON/OFF an electric field shutter 8. A width (w) of the electric field shutter separated by the discharge hole and a length (d) of the shutter along a discharge direction of the gas ink 3" are set to hold a relation d/w>=1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus such as a copying machine, a facsimile, a printer, and more particularly, to a recording medium (recording paper) by selectively ejecting gaseous ink intermittently from an ejection hole. ) It relates to an image recording device which forms an image by adhering or penetrating onto the surface.

[0002]

2. Description of the Related Art As a conventional example of an ejection type image recording apparatus for ejecting ink to perform printing, there is an image recording apparatus such as an ink jet type or an electrostatic recording type. In the inkjet method, printing is performed by pressurizing a liquid ink stored in an ink tank using a piezoelectric element or the like by an electric signal corresponding to image data and discharging the ink from a nozzle. In the electrostatic recording method, powder or liquid (fog) ink is charged and ejected from the nozzle by electrostatic attraction, and the shutter provided at the tip of the nozzle is electrified by an electric signal corresponding to image data. Printing is performed by opening and closing.

In addition, as another method, there is a technique of ejecting ink having a gas flow and adhering it onto a recording medium. With this method, it is possible to perform printing with high resolution, excellent gradation, and less bleeding because the nozzles are less likely to be clogged because the gaseous ink is ejected and the pixels are recorded in the molecular state. There are advantages.

As a conventional example of this system, Japanese Patent Publication No. 56-202
There is an image recording device disclosed in Japanese Patent Laid-Open No. FIG. 13 shows this image recording apparatus. The printing operation in this image recording apparatus is performed as follows. The ink 103 housed inside the print head 100 is heated and vaporized by a heating device 102 composed of an electric heater 113 and its power source 114, and vaporized gaseous ink 103 'is ejected. When the gaseous ink 103 ′ is ejected and simultaneously passes through the charging electrode 104, it is charged by the power source 105 inserted between the charging electrode 104 and the print head 100. The charged gaseous ink 103 ′ is focused by the electric field lenses 106 and 107, and then the ejection amount is controlled by the signal source 110 when passing through the electric field shutter 115, and the ink head 103 flies toward the back electrode 111.
An image is formed on the recording medium.

[0005]

However, in the ink jet system, air cannot enter the ink tank due to the entry of air into the ink tank, and printing cannot be performed. However, there is a problem in that the image quality is deteriorated due to clogging of ink and ink bleeding on the recording medium. Further, in the electrostatic recording method, when the ink is a powder, there is a problem that the ink particles are solidified by blocking and cause clogging, and when the ink is a liquid, the same clogging and bleeding as in the inkjet method is caused. There was a point.

Further, in the above-mentioned method of ejecting the gas-containing ink, since the gaseous ink is always ejected, the ink not used for recording is wasted and the running cost is increased. There was a problem. Furthermore, since a device for collecting unused gaseous ink and a device for cleaning the periphery of the electric field shutter 115 are required, there is a problem in downsizing and maintainability of the device. The movement of the gaseous ink 103 ′ from the print head 100 to the charging electrode 104 increases the pressure in the print head 100 due to the volume expansion due to the vaporization of the ink 103, and the gaseous ink 3 ′ is ejected. Because it is done by
There was a problem of poor responsiveness. Furthermore, since the ejection amount differs depending on the amount of the ink 103 in the print head 100,
Due to this influence, there is also a problem that the print quality is deteriorated such as uneven density.

Therefore, in order to solve the above-mentioned problems, the applicant of the present invention intermittently ejects a gaseous ink in accordance with an electric signal corresponding to image data to be recorded, and makes the ink adhere to or penetrate the recording medium. Then, a new image recording apparatus for obtaining an image was previously proposed in Japanese Patent Application No. 7-49778 and Japanese Patent Application No. 7-234323.

The configuration of these image recording apparatuses is shown in FIG.
This will be described with reference to FIG. As shown in FIG. 1, powder ink 3 is stored inside the print head 1. The print head 1 has an electric heater for heating the ink 3.
A heating device 2 including a heat radiating plate 13 'and a heat radiating plate 13', a charging electrode 4 for charging the heated and vaporized gaseous ink 3 ", and a plurality of ejection holes 14 for ejecting the gaseous ink 3" from the print head 1 (see FIG.
12) and the electric field shutters 8 disposed on both sides of the discharge hole 14.

During printing, the heating device 2 heats the ink 3 to vaporize it. In this state, +2 to the charging electrode 4
A voltage of 5 kV is applied. As a result, corona discharge occurs in the direction of the heating device 2 which is grounded, so that the gaseous ink 3 ″ is charged with positive ions. Subsequently, it is arranged on the back side of the printing surface of the recording medium 12. -0.5 on back electrode 11
A voltage of ˜2 kV is applied to induce the gaseous ink 3 ″ onto the recording medium 12.

Here, the electric field shutter 8 is adapted to apply a voltage of 50 V to 1 kV to the electrodes by the output signal of the control unit 9 corresponding to the electric signal of the image data to be recorded. It is possible to control the passage of the ink 3 ″ in the shape of a circle, or the prevention of the passage of the ink. Ink 3 ″ of the recording medium 12 is guided by the back electrode 11 to the recording medium 12
It adheres to the top, and printing is performed with this. Here, the ink 3 before heating is not limited to powder, and liquid ink can also be used. When liquid ink is used, there are advantages that it is excellent in transportability and the amount of energy required for vaporization is small.

Next, the configuration of an image recording apparatus according to another embodiment proposed by the applicant of the present application in the above application will be described with reference to FIG. Liquid ink 3 ′ is stored inside the print head 1. The print head of the image recording apparatus according to the present embodiment includes the heating device 2 and the two charge injection electrodes similar to those described above, and the charging electrode 4 that charges the ink 3 ′.
Discharge hole 14 (see FIG. 2) consisting of slit holes and discharge hole 14
The electric field shutters 8 are provided on both sides of the long side of the.

The printing operation is performed as follows. First, the potential difference between both ends of the charging electrode 4 is set to 2 to 5 kV, and the electric charge is injected into the ink 3 ′ to be charged with + ions. Subsequently, the charged ink 3 ′ is vaporized by the heating device 2.
As a result, the charged ink 3 becomes gaseous. Then, a voltage of -1 kV is applied to the back electrode 11 disposed on the back side of the printing surface of the recording medium 12 to record the ink 3 ". Guide on medium 12.

Here, the electric field shutter 8 is usually 50 V to
A voltage of 1 kV is applied to control passage and blocking of passage of the ink 3 ″. That is, the electric field shutter 9 outputs each pixel by an output signal of the control unit 9 corresponding to an electric signal of image data to be recorded. The electric potential of the comb-teeth-shaped electrode corresponding to is controlled, and this control controls the passage of the ink 3 ″. That is, the ink 3 ″ is intermittently ejected according to the control content.

Ink 3 ″ that has passed through the electric field shutter 8
Is guided by the back electrode 11 and adheres onto the recording medium 12,
Printing is now performed. Note that, also in this embodiment,
Powdered ink can be used. However, when liquid ink is used, there is an advantage that charging unevenness is less than that of powder and efficient charging is possible. On the other hand, the powder ink has an advantage that there is little leakage from the print head 1. In addition, in the present embodiment, the ink 3 '
The ink is charged by injecting an electric charge into the ink. However, it is also possible to charge the ink by another method, for example, triboelectric charging.

As described above, in the image recording apparatus previously proposed by the applicant of the present application, since the ejection of the gaseous ink 3 ″ is controlled in the print head 1 according to the image data to be recorded,
Since more than the required amount of ink 3 "is not ejected,
Excellent printing efficiency.

Further, since the heating device 2, the charging electrode 4 and the electric field shutter (electric field shutter section) 8 are integrated into a print head, the ink 3 "blocked by the electric field shutter section is transferred to the electric field shutter section. The degree of adhesion and clogging can be reduced.
No need for a recovery device or cleaning device.

Particularly, in the former embodiment, since the ink after vaporization is charged, the ink can be charged even if it is an insulating substance, so that there is an advantage that the type of ink to be applied can be expanded. is there. Further, since it is unlikely to be affected by the environment and the like, there is an advantage that stable charging is possible.

On the other hand, in the latter embodiment, since solid or liquid ink is charged and then heated to gas, harmful substances such as ozone are not generated.
Therefore, it is not necessary to take measures against ozone, and there is an advantage that it can contribute to downsizing of the device configuration.

Further, when the ejection holes 14 for the ink 3 "are formed by slit grooves, the ability to prevent clogging of the ink 3" can be improved and the structure is simplified as compared with the case where a large number of ejection holes 14 are provided. There is an advantage that can be realized.

As described above, the image recording apparatus previously proposed by the applicant of the present application has various advantages described above. However, there is still room for improvement in the following points.

(1) In order to print with this image recording apparatus, it is necessary to fill the inside of the print head 1 with the gaseous ink 3 ″ in advance, but printing is performed by vaporization of the heated ink. The pressure inside the head 1 rises, and when the pressure inside the head exceeds the outside pressure of the head, the back electrode
Even when there is no electric field due to 11, the ink 3 ″ may leak from the ejection hole 14 due to the pressure difference.
Therefore, in order to enable intermittent ink ejection in accordance with the electric signal, it is necessary to realize reliable ink interruption.

As an example of the countermeasure, a voltage V (OFF) applied to the control electrode 8b of the electric field shutter 8 at the time of ON is applied.
At times, a method of increasing 0 V) can be considered. By the way, the control electrodes 8b are arranged at intervals according to the resolution, for example, 150
At the time of dpi, since it is formed at intervals of about 200 μm, V
= 1 kV, it becomes 5 kV / mm, which is far beyond the dielectric breakdown voltage. Therefore, the upper limit of the voltage V applied to the control electrode 8b of the electric field shutter 8 needs to be suppressed to the dielectric breakdown voltage or less.

(2) To perform color printing, yellow,
Where it is necessary to use a plurality of types of inks such as magenta, cyan, or black added thereto, the sublimation temperatures of these inks are different. Therefore, in order to deal with a plurality of inks having different sublimation temperatures, it is necessary to adjust the ink heating temperature according to the sublimation temperature of the ink used. Since the head internal pressure changes with the change of the head internal temperature, that is, the heating temperature, the voltage value at the time of ON applied to the control electrode 8b of the electric field shutter 8 also depends on the ink heating temperature, that is, the type of ink. Need to be adjusted accordingly.

By the way, in the image recording apparatus previously proposed by the applicant of the present application, since the improvement points described in the above (1) and (2) are not properly considered, it is necessary to solve such a problem. The current situation is that it has not arrived.

The present invention has been made in view of the above circumstances, and it goes without saying that the effect of the image recording apparatus previously proposed by the applicant of the present application is exhibited, and the leakage of ink due to heating is surely performed. Can be prevented and
An object of the present invention is to provide an image recording apparatus that can flexibly cope with the case where different inks are used and the thermal characteristics of the inks are different.

Another object of the present invention is to reduce the voltage of the electric field shutter as much as possible, and to deal with it with a small-scale power supply device. As a result, the influence of noise on peripheral equipment is minimized. An object of the present invention is to provide an image recording apparatus that can suppress the above.

[0027]

In order to achieve the above object, an image recording apparatus of the present invention comprises a heating device for heating and vaporizing solid or liquid ink, and a vaporized gaseous ink for a print head. An ejection device that ejects from the formed ejection holes and an ejection control device that controls the gaseous ink to intermittently eject in accordance with an electric signal corresponding to image data to be recorded, and the ejection device, The discharge control device includes a charging electrode unit for charging the gaseous ink and a back electrode unit disposed on the back surface of the recording medium for guiding the charged gaseous ink onto the recording medium. An image recording apparatus comprising an electric field shutter section electrically controlling ejection of gaseous ink, the electric field shutter section being an image recording apparatus in which a direction of a main electric field is perpendicular to an ejection direction of the gaseous ink, The electric field The discharge part is separated by the discharge hole, and the relationship between the width w between the separated electric field shutters and the length d of the electric field shutter part along the discharge direction of the gaseous ink is d / w ≧ 1. Is configured to be.

The image recording apparatus of the present invention includes a heating device for heating and vaporizing solid or liquid ink, an ejecting device for ejecting vaporized gaseous ink from an ejection hole formed in the print head, and recording. A discharge electrode device for controlling the gaseous ink to intermittently discharge in accordance with an electric signal corresponding to image data to be formed, and the discharging device has a charging electrode portion for charging the gaseous ink; The ejection control device is provided on the back surface of the recording medium, and is composed of a back electrode part that guides the charged gaseous ink onto the recording medium.
An image recording apparatus comprising an electric field shutter section electrically controlling ejection of the gaseous ink, the electric field shutter section having a main electric field direction perpendicular to the ejection direction of the gaseous ink. , So that the voltage applied to the electric field shutter unit satisfies the relationship of the following formula (1): √V> (w / d) · √ [2C / (q · N)] · √T ... (1) w: Width between separated electric field shutters d: Length of electric field shutter part along ejection direction of gaseous ink T: Heating temperature of ink q: Charge amount of gaseous ink N: Number of particles of gaseous ink C : Gas constant is set.

Further, the image recording apparatus of the present invention comprises a heating device for heating and vaporizing solid or liquid ink, an ejecting device for ejecting the vaporized gaseous ink from an ejection hole formed in the print head, and recording. A discharge electrode device for controlling the gaseous ink to intermittently discharge in accordance with an electric signal corresponding to image data to be formed, and the discharging device has a charging electrode portion for charging the gaseous ink; The ejection control device is provided on the back surface of the recording medium, and is composed of a back electrode part that guides the charged gaseous ink onto the recording medium.
An image recording apparatus comprising an electric field shutter section electrically controlling ejection of the gaseous ink, the electric field shutter section having a main electric field direction perpendicular to the ejection direction of the gaseous ink. The solid or liquid ink is housed in an ink cartridge, the ink cartridge is detachably attached to the apparatus main body, and information indicating the sublimation temperature of the ink is written in the ink cartridge.

Preferably, an ink discriminating device for reading information on the ink sublimation temperature written on the ink cartridge is provided.

Further, preferably, the sublimation temperature of the set ink is discriminated based on the signal from the ink discrimination device, and the ink heating temperature T with respect to the ink sublimation temperature T _g is determined.
To satisfy the following equation (2): T = T _g + ΔT (2) The heating device is driven and controlled, and the applied voltage V when the electric field shutter is ON is given by the following equation (3). To satisfy the relationship of V = a · T + ΔV (3)

[0032]

[Equation 2]

W: width between separated electric field shutters d: length of electric field shutter portion along ejection direction of gaseous ink T: heating temperature of ink q: amount of charge of gaseous ink N: of gaseous ink Number of particles C: Gas constant is controlled.

The operation will be described below.

First, as described above, if the relationship between the width w between the separated electric field shutters and the length d of the electric field shutter portion along the ejection direction of the gaseous ink is set to d / w ≧ 1. As is clear from the description of Embodiment 1 described later, the value of the applied voltage V to the electric field shutter can be made as small as possible.

If the value of the voltage V applied to the electric field shutter is made as small as possible, firstly, the insulation between the plurality of control electrodes constituting the electric field shutter can be secured. Secondly, since the power supply scale can be reduced, the noise emission to the surroundings can be reduced accordingly.

Further, as described above, the applied voltage of the electric field shutter unit is √V> (w / d) · √ [2C / (q ·
N)] · √T, it is possible to reliably prevent the gaseous ink in the heated state from leaking out of the print head, so that the printing efficiency can be further improved.

Furthermore, when the information indicating the sublimation temperature of the ink is written on the ink cartridge and this information is read by the ink discriminating device and the voltage applied to the electric field shutter section is controlled according to the read result, the type of ink, etc. Regardless of this, it is possible to reliably prevent accidental leakage of the heated gaseous ink from the print head. That is, even when the ink used is different and the thermal characteristics of the ink are different, it is possible to deal flexibly.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the image recording apparatus of the present invention. The basic configuration of this image recording device is as follows. The print head 1 has a long rectangular shape in the front and rear cross-sectional view, and a powder ink 3 is contained in the lower portion inside the print head 1. A heating device 2 including an electric heater 13 for heating the ink 3 and a heat radiating plate 13 ′ is disposed below the ink containing portion and corresponding to the bottom of the print head 1. . On the other hand, above the ink container,
A charging electrode 4 for charging the vaporized gaseous ink 3 ″ heated by the heating device 2 is provided. The charging electrode 4 is composed of a thin wire electrode of 50 to 80 μm.

In addition, a discharge hole 14 for the ink 3 "is formed in the center of the upper wall 1a of the print head 1 in the left-right direction. As shown in FIG. 2, this discharge hole 14 is a slit groove. The electric field shutters 8 are provided on both sides of the long side of the discharge hole 14. The length L of the slit 14 is L.
Is set to a length corresponding to the print width when the print head 1 is a line head, for example, A4 size 200 m
m, A5 size is set to about 140 mm. In addition, the width W of the slit 14 is 2 when the recording density is 150 dpi.
It is set to 00 μm.

The upper part of the print head 1 is a conveyance area for the recording medium 12, and the back electrode 11 is provided on the back side of the recording medium 12.
Are arranged horizontally. The back electrode 11 guides the charged ink 3 ″ onto the recording medium 12. The back electrode 11 has almost the same size as the electric field shutter 8, and since the ink 3 ″ that is positively charged is attracted, A negative potential, for example, a voltage of -1 kV is applied.

The electric field shutter 8 has a common electrode 8a.
And a control electrode 8b provided in a comb shape at an interval of 169 μm corresponding to the recording density. The common electrode 8a is grounded. In addition, the control electrode 8b normally receives 50V to 1kV (High level; "H") or 0V (Low level; "L") depending on an output signal from the control unit 9 corresponding to an electric signal of image data to be recorded. Is applied. That is, the voltage of the control electrode 8b is, for example,
In the case of 500V (“H”), the electric field shutter 8 is turned on, and an electric field is generated from the control electrode 8b toward the common electrode 8b, so that the positively charged ink 3 ″ cannot pass through the electric field shutter 8. On the other hand, the control electrode 8
When the voltage of b is 0V (“L”), an electric field is not generated between the control electrode 8b and the common electrode 8a, so that the ink 3 ″ is attracted to the electric field by the back electrode 11 to cause the electric field shutter 8 to move. In this case, the electric field shutter 8 functions as OFF. In this way, the ejection of the ink 3 ″ can be intermittently controlled by turning ON / OFF the voltage of the control electrode 8b. Further, by controlling the potential of the control electrode 8b corresponding to each pixel, the passage of the gaseous ink 3 ″ can be controlled on a pixel-by-pixel basis.

A colored ink is used as the color material of the ink. For example, in yellow, anthrythothiazole type, quinophthalone type, pyrazolonazo type, pyridone azo type, styryl type, etc. are used, in magenta, anthraquinone type, dicyanoimidazole type, thiadiazole azo type, tricyanovinyl type, etc. are used, and in cyan, Azo type, anthraquinone type, naphthoquinone type, indoaniline type and the like can be used. Further, although the powder ink 3 is used in the first embodiment, it is also possible to use the liquid ink. When each ink 3 is used, the above-mentioned effects are produced.

In the above image recording apparatus, since the potential of the common electrode 8a is grounded, the ink 3 "is ejected when the potential of the control electrode 8b is" L "(logically active state). ). Conversely, the potential of the control electrode 8b is "H".
In the case of, the ink 3 ″ is cut off (logically inactive state), and the relationship between the potential of the control electrode 8b and the ejection of the ink 3 ″ is a negative logic relationship, but the potential of the common electrode 8a is , For example 500V, the potential of the control electrode 8a is 500V
Positive logic operation can be performed by changing to (“H”) or 0V (“L”). This is the same in the following embodiments.

In the above embodiment, the gaseous ink 3 ″ is positively charged, but it may be negatively charged by applying a negative voltage to the charging electrode 4. However, in the case of negative charging, Since harmful substances such as ozone are generated more than positively charged, it is necessary to take measures to prevent them.

By the way, in the image recording apparatus of the present invention, in order to perform printing, it is necessary to fill the inside of the print head 1 with the gaseous ink 3 ″ in advance.
Is vaporized, the pressure inside the print head 1 rises. When the internal pressure of the head becomes equal to or higher than the external pressure of the head, the ink 3 "is generated even when there is no electric field due to the back electrode 11.
As described above in the problem to be solved by the invention, in order to enable intermittent ink ejection in accordance with an electric signal, the ink 3 "must be reliably discharged. It is necessary to realize a proper cutoff.

For that purpose, the head pressure P
And the voltage V that must be applied to the control electrode 8b in order to keep the particles of the ink 3 ″ in the print head 1.
Need to seek a relationship with. The derivation procedure will be described below.

First, since the ejection direction of the ink 3 "accompanying the rise of the internal pressure and the direction of the electric field E by the electric field shutter 8 are at right angles to each other, as shown in FIG. The actual ejection direction of ink is given as the sum of these two vectors, and can be decomposed into a uniform velocity motion in the vertical direction (coordinate z) and a uniform acceleration in the horizontal direction (coordinate x).

The velocity component of the ink particles in the z direction in the discharge hole 14 and its vicinity is only in the + z direction and v ⁽ⁱ⁾ _z > 0 unless the collision of the ink particles with each other is taken into consideration. However, i = 1 ..., N, and N is the number of ink particles in the print head 1. In addition, except for the vicinity of the discharge hole 14, v ⁽ⁱ⁾ _x and v ⁽ⁱ⁾ _y similarly take both positive and negative values. However, the subscript y indicates the direction (coordinate y) perpendicular to the paper surface, and v ⁽ⁱ⁾ _y indicates the velocity component of the ink particle in the y direction.

Therefore, the velocity of the ink particles in the vicinity of the ejection hole 14 is expressed by the following equation (4).

V ⁽ⁱ⁾ = (v ⁽ⁱ⁾ _x , v ⁽ⁱ⁾ _y , | v ⁽ⁱ⁾ _z |) (4) On the other hand, the head pressure P in the ejection hole 14 is the ink in the ejection hole 14. Since it is caused by the velocity component v ⁽ⁱ⁾ _z of the particle in the z direction, the pressure P in the head is calculated from the gas molecule kinetic theory.
Is expressed by the following equation (5).

[0053] ^{PαΣm (i) · v (i} ) z 2 ... (5) where the mass of each ink particles are the same, equation (5) can be rewritten in the following equation (6).

[0054]

(Equation 3)

Where

[0056]

(Equation 4)

Is a velocity root mean square value in the z direction. Therefore, it can be seen from the above (6) that the pressure P in the head is proportional to the velocity root mean square value in the z direction.

By the way, assuming that the ink 3 ″ having gas flow is an ideal gas, its equation of state is expressed by the following equation (7).

P · U = C · T (7) Here, U is the volume of the ink head containing the ink 3 ″, C is the gas constant, and T is the ink heating temperature.

Since U = constant, the relationship of P∝T is established.

Therefore, the above equation (6) is represented by the following equation (8) using the ink temperature T.

[0062]

(Equation 5)

The equations of motion for the vertical and horizontal directions are as follows.

[Vertical direction] In FIG. 4, the mass, charge, and diffusion rate of the charged ink particles i are m ⁽ⁱ⁾ , q ⁽ⁱ⁾ , and
Let v ^{(i )} _z (T). However, i = 1, ..., N,
v ⁽ⁱ⁾ _z (T) is a function of the temperature T, and increases as the temperature increases.

For simplicity, let m ⁽ⁱ⁾ = m and q ⁽ⁱ⁾ = q. Influence of gravity is neglected, the initial conditions: t = 0 at z = 0 and _{^{v (i) z = v 0}} (i), further, if a constant velocity interlocking speed v ⁽ⁱ⁾ _z = const, The time t ₁ required for the ink particles to pass through the electric field shutter 8 is d = v ⁽ⁱ⁾ _z · t
^{(i) Since} the relationship of ₁ is established, it is expressed by the following equation (9).

T ⁽ⁱ⁾ ₁ = d / v ⁽ⁱ⁾ _z (9) However, d is the length of the electric field shutter portion along the ejection direction of the ink 3 ″.

Since the actual ink particles have a velocity distribution, the time t ₁ also has a distribution.

[Horizontal Direction] In FIG. 5, consider the case where the charged ink particles are gently released at x = 0.

Initial condition; if v _x (t = 0) = 0 x (t = 0) = 0, the acceleration α satisfies the relationship of F = q · E = m · α. Therefore, the following (10) It is represented by. However, F is a force acting on the charged ink particles. Further, E indicates the magnitude of the electric field.

Α = (q · E) / m (10) Since the relationship of E = V / w holds, the above equation (10) can be rewritten as the following equation (11).

Α = (qV) / (mw) (11) where V is the voltage applied to the electric field shutter 8.

Therefore, assuming that the time required to reach x = w is t ₂ , the width w between the separated electric field shutters is
Is expressed by the following equation (12).

W = (1/2) αt ₂ ² (12) Here, since only the influence of the electric field is taken into consideration, in the equation (12), the velocity component v _x of the ink particle in the x direction
Was ignored.

By substituting the equation (11) into the equation (12) and arranging it, t ₂ is represented by the following equation (13).

T ₂ = √ [(2m · w ² ) / (q · V)] (13) From the above, in order to reliably block the charged ink particles by the effect of the electric field shutter 8, it is necessary to increase the pressure. The electric field shutter 8 having the electrode interval w by the action of the electric field from the time t _{1 when the} gaseous ink 3 ″ passes through the ejection hole 14 having the length d
It is necessary that the time t ₂ for moving between the vehicles is short, that is, t ₁ > t ₂ , and therefore the relationship of the following equation (14) needs to be established.

D / v ⁽ⁱ⁾ _z > √ [(2m · w ² ) / (q · V)] (14) When the above equation (14) is modified, the following equation (15) is obtained.

[0077] _{^{√V> v (i) z ·}} √ [(2m · w 2) / (q · d 2)] ... (15) To illustrate the region satisfying this inequality is as shown in FIG 6. The solid line represents √V = D · v ⁽ⁱ⁾ _z .

However,

[0079]

(Equation 6)

I said.

It can be seen from FIG. 6 that when D = constant, V increases quadratically with an increase in v ⁽ⁱ⁾ _z . Also, if v ⁽ⁱ⁾ _z = constant, the smaller V is, the smaller V is. That is, if m and q are constant, D becomes a function of (w / d), but w / d is a constant determined at the design stage of the print head 1, so it is designed to be as small as possible. To do. This does not change even if the shapes of the other parts of the print head 1 change unless the geometrical size of the length l and the width w of the discharge hole 14 in the head discharge part, that is, the shutter part is different.

On the other hand, v ⁽ⁱ⁾ _z is an operating condition such as the structure (volume, etc.) of the print head 1, the ink heating temperature (this ink heating temperature depends on the ink sublimation temperature), the temperature in the print head 1, etc. And v ⁽ⁱ⁾ _z are the same, but if v ⁽ⁱ⁾ _z is the same, it is possible to reduce the application to the electric field shutter 8 by reducing w / d. The voltage V can be reduced.

For example, when the recording density is 150 dpi, the width w of the electric field shutter 8 (width of the ejection hole 14) is w = 200 μm.
Therefore, if the applied voltage to the electric field shutter 8 in the print head 1 having the electric field shutter length d = 100 μm is V ₁₀₀ , the applied voltage V ₂₀₀ to the print head 1 at d = 200 μm and d = 400 μm, V ₄₀₀ is V
₂₀₀ = V _100/4, is given by V ₄₀₀ = V _100/16. That is, the voltage applied to the electric field shutter 8 is 1/4,
It can be reduced to 1/16.

By the way, as described above, v ⁽ⁱ⁾ _z (T) has a velocity distribution and is also a function of temperature. Therefore, it is not practical to make the above equation (14) hold for all ink particles, especially particles having a low velocity. Therefore, for example, the square root of the root mean square value of v ⁽ⁱ⁾ _z

[0085]

(Equation 7)

Or the average value of v ⁽ⁱ⁾ _z

[0087]

(Equation 8)

[0088] Alternatively v ⁽ⁱ⁾ the maximum distribution value of _z v _m or more of v ⁽ⁱ⁾
_{For z} , determine the value of V so that at least equation (14) holds. Here, between these three,
Since the relationship of the following formula (16) is established,

[0089]

[Equation 9]

Using the square root of the root mean square,

[0091]

(Equation 10)

It is assumed that

Here, the above expression (17) is applied to the electric field shutter 8
Rewriting the applied voltage V to the equation (18) holds the relationship.

√V> (w / d) · √ (2m / q) · √ (v _z ² ) ... (18) From the above equation (5), v _z ² is proportional to the pressure P, so the electric field shutter 8 The voltage V applied to the head and the pressure P in the head are
It can be seen that there is a linear relationship.

From the equation (18), V can be reduced by (i) w / d (ii) m (iii) 1 / q (iv) √ (v _z ² ) or the head pressure P is reduced. I know it's good.

The following implementation measures can be considered for each of them.

(I) Shutter size d / W ≧ 1 (ii) Gaseous ink particle mass is reduced (iii) Charge amount is increased (iv) Head pressure rise is suppressed (ink heating temperature is reduced) Among the above-mentioned measures, the present invention adopts the measure (i), and specifically, the image recording apparatus according to claim 1. It has been adopted in.

Here, the advantage of being able to reduce the voltage applied to the electric field shutter 8 is, first of all, the control electrode 8b.
The insulation between them can be secured. Secondly, the scale of the power supply can be reduced, and the noise emission to the surroundings can be reduced accordingly,
The reliability of the image recording device can be improved.

Next, referring to FIG. 7 and FIG.
The configuration of the control system of the image recording apparatus and the printing operation will be described. The CPU 20 serves as a control center of the image recording apparatus, and as shown in FIG. 7, controls heating of the heating apparatus 2 and energization and control of the discharging apparatus including the charging electrode 4 and the back electrode 11. The ejection control device composed of the section 9 and the electric field shutter 8 is controlled, and the printing operation of the print head 1 is controlled by these control contents. The details will be described below.

From the CPU 20 to the print head 1, FIG.
When the head control signal having the waveform shown in (a) is given, as shown in (b) in the figure, the heating device 2 uses the rising edge (point A) of the head control signal as a trigger to elapse a predetermined time from point A. At the point B, the electric heater 13 is driven. Further, at this time, a voltage of +2 to 5 kV is applied to the charging electrode 4 (see (c) in the figure).

When the heating device 2 is driven, the solid or liquid ink 3 is heated, and when the temperature exceeds the sublimation temperature T _g of the ink 3, the ink 3 is vaporized to become a gaseous ink 3 ″. The ink 3 ″ increases with the passage of time, and reaches the threshold value at point C (see FIG. 7D). Here, the threshold value means the amount of the gaseous ink that is sufficient for ejection, and when the threshold value is exceeded, the printable state is set. This state means that the print head 1 is filled with high-pressure ink 3 ″.

The heating device 2 uses the ink sublimation temperature T _g.
Constant control is performed so as to attain the above certain temperature T. Therefore, the relationship of T = T _g + ΔT is established. For example, T _g = 14
If 0 ° C, T = 155 ° C.

The point at which the driving of the heating device 2 is disclosed may not be the same as the point B, and for example, at the point B ′ before the point C (see (f) in the same figure), all the control electrodes 8b of the electric field shutter 8 are shown. Then, a voltage of about 50 to 1 kV may be applied to turn on the electric field shutter 8. That is, in this state,
This is because the ejection of the ink 3 ″ is blocked.

As shown in (e) of the figure, at time D when the printable state is reached, the CPU 20 outputs a print start / end signal to the control section 9. In the first embodiment, the determination as to whether or not the ink 3 ″ exceeds the threshold value is not made directly, so the time after heating the electric heater 13 or the temperature of the print head 1 is measured. Then, the CPU 20 makes an estimation, and the CPU 20 generates a print start / end signal by comparing the indirect data thus obtained with the time or temperature data which has been input as a target value in advance. The section 9 uses the rising edge of the print start / end signal as a trigger to request the transmission of image data from an image memory (not shown), and when the data transfer is completed, the electric field shutter 8 is sent to point D ′ shown in FIG. The electric field shutter 8 is connected to a power supply device (not shown) which supplies a voltage of 500 V, and the electric field shutter 8 is connected to an electric field shutter according to the image data. 500V is ON / OFF to over 8.

At the point D'when the electric field shutter 8 starts to turn ON / OFF, a voltage of -1 kV is applied to the back electrode 11 (see FIG. 9 (g)). The print start / end signal is maintained at the "H" level during printing.

When the printing operation is completed, the print start / end signal falls to the "L" level at point E shown in FIG. 7E, and this fall is used as a trigger for the heating device 2, the charging electrode 4 and the rear surface. All the electrodes 11 are turned off.
Even if the heating device 2 stops energizing the electric heater 13, the ink 3 ″ is not immediately cooled and remains in the print head 1. Therefore, after the printing is completed, the electric field is reached to the point E ′ after the threshold F. The shutter 8 is forcibly turned on to prevent the ink 3 ″ from leaking to the outside (see (f) in the figure). And
After the point E ', the electric field shutter 8 is turned off until the next printing operation is started.

(Second Embodiment) Next, a second embodiment of the image recording apparatus of the present invention will be described. In this second embodiment,
Focusing on the relationship between the voltage V applied to the electric field shutter (hereinafter referred to as the electric field shutter voltage V) and the ink heating temperature T,
By controlling the electric field shutter voltage V on the basis of the relational expression between the two, leakage of the ink 3 ″ is prevented.

First, the relationship between the electric field shutter voltage V and the ink heating temperature T is obtained.

Considering the case where the left side = the right side in the above equation (18), the following equation (19) is established.

√V _EQUAL = (w / d) · √ (2m / q) · √ (v _z ² ) = (w / d) · √ (2m / q) · √ [(C · T) / (m -N)] = (w / d) -√ [(2C / (q-N)]-√T = (w / d) -b-√T ... (19)

[0111]

[Equation 11]

I said.

If both sides of the equation (19) are squared, then V _EQUAL = (W / d) ² · b ² · T (20)

Here, the electric field shutter voltage V is V> V
_Since it is _EQUAL , it can be expressed by the following equation (21).

V = V _EQUAL + ΔV = (w / d) ² · b ² · T + ΔV = a · T + ΔV (21) where ΔV is a positive constant, and the ambient temperature and the charge amount q
It is decided in consideration of such variations. Also,

[0116]

(Equation 12)

I said.

From the above equation, it can be seen that there is a linear relationship between the electric field shutter voltage V and the ink heating temperature T.

The ink heating temperature T is expressed by the following equation (22) based on the sublimation temperature T _{g of the} ink.

T = T _g + ΔT (22) For example, when T _g = 140 ° C., ΔT = 15 ° C., T = 155
° C. Therefore, the heating device 2 controls the electric power applied to the electric heater 13 so that T _g = 140 ° C. = constant.

At this time, the gaseous ink 3 "due to the stability of the control device and the influence of disturbance, the ambient temperature, and the difference in the print density.
The ink heating temperature T may fluctuate due to a change in the consumption amount of the ink. If it is known that the temperature fluctuation is small, it is included in ΔV, and control is performed so that V = constant. To do. Further, q, and hence the constant a, may fluctuate due to fluctuations in the charge amount. In this case as well, if the value is small, it may be included in ΔV and V = constant.

However, when the fluctuation of the ink heating temperature T is large, the control for adjusting V based on the equation (21) is performed.

The control method will be described below with reference to FIGS. 9 and 10. FIG. 9 shows the configuration of the control system of the image recording apparatus according to the second embodiment. This control system is provided with the ink discriminating device 21, and the control system of the image recording apparatus of the first embodiment described above. It has the same structure as.

Here, the ink discriminating apparatus 21 reads the ink information displayed on the ink cartridge containing the ink 3, and gives the ink discriminating signal to the CPU 20. Then, the CPU 20 determines the ink sublimation temperature T from the ink determination signal.
Determine _g and perform the control described later. The parts corresponding to those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the above equation (21), ΔV is a known amount (in the second embodiment, set to 45 V, for example).
As is apparent from 10, if it is known that the electric field shutter voltage V is V1 at a certain ink heating temperature T1, the constant a can be obtained. Therefore, the electric field shutter voltage V2 when the ink heating temperature T is T2. Is calculated according to equation (21). For example, T1 = 155 ℃, V1 = 200
When V and ΔV = 45V, substituting these values into equation (21) gives a = 1 (V / ° C), so when T2 = 140 ° C, the electric field is V2 = 185V. The shutter voltage V is controlled. In this situation, in addition to the above case, for example, when the sublimation temperature is lowered due to the improvement of the ink, or when the ink of a different manufacturer is used, or between the colors in the color printing. This occurs when the ink sublimation temperatures in the above are different. Therefore, when the sublimation temperature T _g is known for a plurality of inks having different thermophysical property values, if the electric field shutter voltage is controlled according to the equation (21), the electric field shutter voltage appropriate for each ink is obtained. Can be applied. In this case, it goes without saying that the heating device 2 is controlled so as to change the ink heating temperature T according to the ink sublimation temperature T _g . That is, with ΔT = 15 ° C. = constant, the relational expression T = T _g
+ ΔT, that is, the ink heating temperature T is given by the equation (22).

Here, the ink 3 is contained in a container generally called a cartridge, and if the cartridge is provided with information indicating the type of ink, the ink can be identified. That is, although the method of identifying information differs depending on the method of writing information in the ink cartridge, a mechanical mechanism such as a lever can be used for information with respect to physical unevenness, and a barcode With such print information, an optical element such as a photo interrupter can be used. Specifically, when using the physical unevenness information, for example, two unevennesses are selectively formed, and the lever is brought into contact with each position. Each lever works as a binary switch, and when there is no unevenness, the lever switch is OFF, and when there is a convex or concave portion, it is turned ON and 2 ² = 4
Since it is possible to have two pieces of information, if each piece of information corresponds to T _g = 140 ° C, 145 ° C, 150 ° C, 155 ° C,
Information on four types of ink can be provided.
Furthermore, if it is possible to selectively form three irregularities, it is possible to have 2 ³ = 8 pieces of ink information.

Similarly, two bar codes are selectively formed, and a reflection type photo interrupter is arranged at each position. If the photo interrupter output is OFF when there is no bar code and ON when there is a bar code, 2 ² = 4 types of ink can be supported.

When the ink cartridge filled with the ink information as described above is mounted on the print head 1, the ink discriminating device 21 reads the ink information and outputs an ink discriminating signal to the CPU 20. The CPU 20 determines the ink sublimation temperature T _g of the ink 3 stored in the ink cartridge based on the ink determination signal, and T = T _g + ΔT in the above equation (22).
The ink heating temperature T is determined by. Further, the voltage V applied to the control electrode 8b of the electric field shutter 8 is determined by V = a · T + ΔV in the equation (21). As ΔT, for example, 15 ° C is set.

In the second embodiment, the ink heating temperature T is determined by the equation (22) with ΔT = constant, but the ink heating temperature T with respect to the ink sublimation temperature T _g is created in advance as a look-up table (LUT). Well, this L
The ink heating temperature T may be determined with reference to UT. Further, also when determining the voltage V applied to the control electrode 8b of the electric field shutter 8, a LUT of the electric field shutter voltage V with respect to the ink sublimation temperature T _g is created,
You may decide with reference to this.

After determining the ink heating temperature T and the electric field shutter voltage V by the above procedure, the CPU 20 outputs a print start signal to each device of the print head 1. This start signal gives the timing of voltage application / release. In FIG. 9, this print start signal is shown by a dotted line.

The CPU 20 inputs a heating control signal to the heating device 2 to heat the ink 3 at the determined ink heating temperature T. As a result, the electric heater 13 is driven so that the heating device 2 reaches the temperature of the above formula. Further, the CPU 20 inputs a charging start signal to the charging electrode 4. As a result, a voltage of 2 to 5 kV is applied to the charging electrode 4 to charge the ink 3 ″. Then, at a time before the amount of the gaseous ink exceeds the threshold value, the electric field shutter voltage control signal is sent to the control unit 9. As a result, a voltage is applied to all the control electrodes 8b of the electric field shutter 8, that is, the electric field shutter 8 is turned on to prevent ink from leaking. A voltage application start signal is output to the electrode 11 to apply a voltage of -1 kV to the back electrode 11. At the same time, the electric field shutter 8 is turned on / off according to the image data, and the printing operation is started. To be done.

When the printing operation is completed, the CPU 20 outputs a control signal to each of the above devices. That is, to the heating device 2, the charging electrode 4 and the back electrode 11, a release signal is output and the voltage application is terminated all at once, and the gaseous ink 3 ″
The generation and discharge of are suppressed. Further, to the electric field shutter 8, a voltage is applied to all the control electrodes 8b immediately after the printing is finished to prevent the leakage of the ink 3 ″. At any time when the amount of the gaseous charged ink is below the threshold value. The electric field shutter voltage V is finally released.

As described above, by recording or forming the ink information in the ink cartridge containing the ink, the optimum ink heating temperature T and electric field shutter voltage are obtained for each ink 3 having a plurality of physical property values. V can be supplied.

The reason will be described below.

For convenience of explanation, the optimum heating temperature is set to T ₁ = T for two types of ink, that is, inks having ink sublimation temperatures of T _g1 and T _g2 (T _g1 > T _g2 ).
_{g1 + ΔT, T 2 = T} g2 + ΔT ( therefore, T _1>
T ₂ ) and the optimum electric field shutter voltage V is V ₁ and V ₂ (V ₁ > V ₂ ) respectively. However, it is assumed that the electric field shutter voltage V is given by the equation (21).

In the image recording apparatus optimized for the ink 3 having the sublimation temperature T _g1 , when the ink having the lower sublimation temperature T ₂ is used, since the ink is heated at the same heating temperature T ₁ , The ink will be overheated, and in the worst case, the ink will be decomposed instead of wasting power.

Further, in the image recording apparatus optimized for the ink having the sublimation temperature T _g2 , when the ink having the higher sublimation temperature T _g1 is used and the ink discrimination device 21 is not provided, Since the ink is heated at a temperature T ₂ lower than the optimum heating temperature T ₁ , the ink does not sublime sufficiently.

Therefore, it becomes necessary to appropriately control the heating device 2 to change the ink heating temperature according to the sublimation temperature of the ink. However, controlling only the heating device 2 causes another problem for the following reason.

That is, in the image recording apparatus optimized for the ink 3 having the sublimation temperature T _g1 , when the ink having the lower sublimation temperature T _g2 is used, in order to eliminate the above-mentioned problems, heating is performed. When the temperature is changed from T ₁ to T ₂ , a voltage of V ₂ is originally required, but an extra voltage of V ₁ > V ₂ is applied. This is a demerit when considering low power consumption of the device.

Further, in the image recording apparatus optimized for the ink having the sublimation temperature T _g2 , when the ink having the higher sublimation temperature T _g1 is used, the heating temperature is When T is changed from T ₂ to T ₁ , the pressure in the head rises, so the electric field shutter 8
If the same voltage V ₂ (<V ₁ ) as before is applied, the electric field shutter 8 does not operate completely, which may cause ink leakage.

However, in the image recording apparatus of the present invention, both the ink heating temperature and the electric field shutter voltage are controlled to be optimal depending on the type of ink, and therefore, excessive heating or insufficient heating of ink, There is no need to worry about increased power consumption or ink leakage.

That is, the heating device is controlled so that the ink heating temperature T becomes T = T _g + ΔT according to the ink sublimation temperature, and the applied voltage V when the electric field shutter section is ON is V = a. Since the control is performed so as to be T + ΔV, each device can always be driven under the optimum driving condition.

(Other Embodiments) The embodiments to which the image recording apparatus of the present invention is applied are not limited to those of the above-described first and second embodiments, and various modifications can be made as shown below. Is. That is, the invention can be similarly applied to an image recording apparatus of a type that vaporizes the charged ink 3 ′ to generate the gaseous ink 3 ″ as shown in FIG. Also,
The same applies to a type having a plurality of discharge holes 14 as shown in FIG. Further, the invention can be similarly applied to an image recording apparatus adopting a friction charging method.

[0144]

According to the image recording apparatus of the present invention described above, printing is performed by intermittently ejecting a gaseous ink, and therefore printing can be performed with a necessary and sufficient ejection amount. There is an advantage that the running cost can be reduced.
Further, since the heating device, the charging electrode and the electric field shutter are integrated into the print head, the degree of the ink blocked by the electric field shutter adhering to the electric field shutter and causing clogging can be reduced. Since an ink collecting device and a cleaning device are unnecessary, there is an advantage that it can greatly contribute to downsizing of the device configuration.

Further, in addition to the above effects, in particular, according to the image recording apparatus of the first aspect, the value of the voltage V applied to the electric field shutter can be made as small as possible, so that the electric field shutter is constructed. Since insulation between a plurality of control electrodes can be secured and the power supply scale can be reduced, the effect of noise on peripheral devices can be reduced and the reliability can be improved accordingly.

In particular, according to the image recording apparatus of the second aspect, it is possible to reliably prevent the heated gaseous ink from leaking out of the print head, so that the printing efficiency is further improved. Can be improved.

Further, in particular, according to the image recording apparatus of the third to fifth aspects, it is ensured that the gaseous ink in the heated state always unexpectedly leaks out of the print head regardless of the kind of ink. Since this can be prevented, it is possible to deal flexibly even when the ink used is different and the thermal characteristics of the ink are different. Therefore, it is particularly effective when applied to an image recording apparatus that performs color printing.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing a part of an image recording apparatus of the present invention according to a first embodiment by cutting out.

FIG. 2 is a perspective view showing details of an electric field shutter portion of the image recording apparatus of the present invention according to the first embodiment.

FIG. 3 is an explanatory diagram showing a force acting on charged ink particles in an electric field shutter unit.

FIG. 4 is an explanatory diagram showing a force in an ink ejection direction that acts on charged ink particles in an electric field shutter unit.

FIG. 5 is an explanatory diagram showing a force in the electric field direction that acts on the charged ink particles in the electric field shutter unit.

FIG. 6 is a graph showing the relationship between the electric field shutter voltage and the velocity component of ink particles in the vertical direction.

FIG. 7 is a block diagram showing a control system of the image recording apparatus of the present invention according to the first embodiment.

FIG. 8 is a timing chart showing a printing operation of the image recording apparatus of the present invention according to the first embodiment.

FIG. 9 is a block diagram showing a control system of the image recording apparatus of the present invention according to the second embodiment.

FIG. 10 is a graph showing the relationship between the electric field shutter voltage and the ink heating temperature.

FIG. 11 is a partially cutaway schematic front view showing another embodiment of the image recording apparatus to which the present invention is applied.

FIG. 12 is a perspective view showing another embodiment of the electric field shutter.

FIG. 13 is a sectional view showing a conventional example of an image recording apparatus.

[Explanation of symbols]

 1 Print Head 2 Heating Device 3 Powder Ink 3 "Gaseous Ink 4 Charging Electrode 8 Electric Field Shutter 8a Common Electrode 8b Control Electrode 9 Control Section 11 Rear Electrode 12 Recording Medium 14 Ejection Hole 20 CPU 21 Ink Discrimination Device d Ink Length of the electric field shutter portion along the ejection direction V Electric field shutter voltage w Width between electric field shutters separated by ejection holes

Continued on the front page (72) Inventor Kaoru Higuchi 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation

Claims (5)

[Claims] 1. A heating device for heating and vaporizing solid or liquid ink, an ejecting device for ejecting vaporized gaseous ink from an ejection hole formed in a print head, and an electric device corresponding to image data to be recorded. A discharge control device that controls so that the gaseous ink is intermittently discharged according to a signal is provided, and the discharging device is disposed on the back surface of the recording medium and a charging electrode portion that charges the gaseous ink. , A back electrode part for guiding the charged gaseous ink onto the recording medium, and the ejection control device is composed of an electric field shutter part for electrically controlling ejection of the gaseous ink. The shutter section is an image recording device whose main electric field direction is perpendicular to the ejection direction of the gaseous ink, and the electric field shutter section is separated by the ejection hole.
The relationship between the width w between the separated electric field shutters and the length d of the electric field shutter portion along the ejection direction of the gaseous ink is configured such that d / w ≧ 1. Image recording device. 2. A heating device for heating and vaporizing solid or liquid ink, an ejecting device for ejecting vaporized gaseous ink from an ejection hole formed in a print head, and an electric device corresponding to image data to be recorded. A discharge control device that controls so that the gaseous ink is intermittently discharged according to a signal is provided, and the discharging device is disposed on the back surface of the recording medium and a charging electrode portion that charges the gaseous ink. , A back electrode part for guiding the charged gaseous ink onto the recording medium, and the ejection control device is composed of an electric field shutter part for electrically controlling ejection of the gaseous ink. The shutter section is an image recording apparatus in which the main electric field direction is at right angles to the ejection direction of the gaseous ink, and the applied voltage of the electric field shutter section is set so as to satisfy the following expression (1). , √V (W / d) √ [2C / (qN)] √T (1) where w: width between separated electric field shutters d: electric field shutter portion along the ejection direction of gaseous ink Length T: ink heating temperature q: amount of charge of gaseous ink N: number of particles of gaseous ink C: gas constant An image recording device characterized by being set. 3. A heating device for heating and vaporizing solid or liquid ink, an ejecting device for ejecting the vaporized gaseous ink from an ejection hole formed in a print head, and an electric device corresponding to image data to be recorded. A discharge control device that controls so that the gaseous ink is intermittently discharged according to a signal is provided, and the discharging device is disposed on the back surface of the recording medium and a charging electrode portion that charges the gaseous ink. , A back electrode part for guiding the charged gaseous ink onto the recording medium, and the ejection control device is composed of an electric field shutter part for electrically controlling ejection of the gaseous ink. The shutter section is an image recording apparatus in which the main electric field direction is at right angles to the ejection direction of the gaseous ink, and the solid or liquid ink is housed in an ink cartridge, Ridge is detachably attached to the apparatus main body, an image recording apparatus characterized by information indicating the sublimation temperature of the ink in the ink cartridge is written. 4. The image recording apparatus according to claim 3, further comprising an ink discriminating device for reading information on the ink sublimation temperature written on the ink cartridge. 5. The sublimation temperature of the set ink is discriminated on the basis of a signal from the ink discriminating device, and the ink heating temperature T with respect to the ink sublimation temperature T _g satisfies the following equation (2). T = T _g + ΔT (2) In order to drive and control the heating device, and the applied voltage V when the electric field shutter unit is ON satisfies the following equation (3), V = a · T + ΔV (3) where, w: Width between separated electric field shutters d: Length of electric field shutter part along ejection direction of gaseous ink T: Heating temperature of ink q: Charge amount of gaseous ink N: Number of particles of gaseous ink C The image recording apparatus according to claim 3 or 4, wherein the gas constant is controlled.