JPH11207963A - Electrostatic ink-jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic ink-jet recording apparatus using an-array of recording heads of low resolution with recording electrodes not arranged highly densely, thereby enabling recording of fine high-resolution images. SOLUTION: In an electrostatic ink-jet recording apparatus having an array of recording heads 10 in which a plurality of recording electrodes 1 are arranged in a line, a recording voltage is supplied separately to each of the plurality of recording electrodes 1 from a recording voltage generation means 3, and ink is discharged from the recording electrode 1 selected from the plurality of recording electrodes 1 correspondingly to the supplied recording voltage, the recording voltage generation means 3 generates the recording voltage having one voltage value among multistage voltage values to the plurality of recording electrodes 1, adjusts the value of the generated recording voltage and deflects the ink discharged from the selected recording electrode 1 in a direction of the line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic ink jet recording apparatus, and more particularly, to an array recording head capable of obtaining a high-resolution recorded image without reducing the distance between recording electrodes of the array recording head. The present invention relates to an electrostatic ink jet recording apparatus provided with:

[0002]

2. Description of the Related Art Conventionally, as an array recording head used in an electrostatic ink jet recording apparatus, for example, the one disclosed in Japanese Patent Publication No. 7-502218 is known.

The array recording head disclosed in Japanese Patent Publication No. 7-502218 has a plurality of wedge-shaped conductive bodies and a plurality of the same wedge-shaped insulating bodies disposed between adjacent conductive bodies. A plurality of voltage generators for individually supplying a recording voltage to each conductive body, and a discharge point arranged at each conductive body and having a sharp ejecting point at a tip end,
An ink supply pipe for supplying ink to the ejection point,
A flow director is disposed in each conductive body in parallel with the ink supply pipe, and a flow director is provided at the tip to allow the remaining ink discharged from the ejection point to flow, and the ink supplied through the flow director is supplied from the conductive body to the flow director. It has an ink discharge pipe for discharging, and a plurality of ejection points are arranged in a line.

In the array-type recording head disclosed in Japanese Patent Publication No. 7-502218, when a high-voltage recording voltage is supplied from a voltage generator corresponding to a selected conductive body,
Due to the electric field formed between the conductive body and the counter electrode arranged on the recording paper side, the ink that has reached the ejection point of the conductive body is ejected to the recording paper side in a spherical shape, and the recording is performed. The ink adheres to the paper in a dot shape, and an image is formed on the recording paper by ink. The size of the recording dot depends on the voltage value and application time applied to the recording electrode, and the larger the voltage value and the longer the application time, the larger the recording dot. As described above, in the electrostatic inkjet recording apparatus, by changing the voltage value and the application time applied to the recording electrodes, recording dots of any size from a relatively small recording dot to a relatively large recording dot are formed. be able to.

[0005]

Problems to be Solved by the Invention Japanese Patent Application Publication No. Hei 7-502
In the array print head disclosed in Japanese Patent No. 218, a print dot of an arbitrary size from a considerably small print dot to a relatively large print dot is formed by changing a voltage value or an application time applied to a print electrode. For example, a recorded image having a resolution of about 300 dpi (dot / inch) can be obtained. However, recently, a high-resolution recorded image of high definition, for example, a recorded image of about 900 dpi has been required. In response to the request,
This cannot be achieved even by using the array recording head disclosed in JP-A-502218.

In order to satisfy such requirements, it is necessary to increase the density of the arrangement of the recording electrodes of the array recording head. When the recording electrodes of the array-type recording head are finely processed, the interference of the electric field between the recording electrodes increases. Therefore, it is difficult to finely process the recording electrodes further. Therefore, there is a problem that a high-definition recorded image as described above cannot be obtained.

SUMMARY OF THE INVENTION The present invention solves such a problem, and an object of the present invention is to record a fine high-resolution image by using a low-resolution array recording head which does not increase the density of recording electrodes. It is an object of the present invention to provide an electrostatic ink jet recording apparatus which is enabled.

[0008]

In order to achieve the above object, an electrostatic ink jet recording apparatus according to the present invention provides a recording voltage applied to each recording electrode in an array recording head or the magnitude of the recording voltage. And changing the application time of the recording voltage in multiple stages, and selecting the magnitude of the recording voltage applied to the recording electrode adjacent to the recording electrode that ejects the selected ink so as to be a voltage value at which the ink is not ejected. Means for deflecting the ejected ink in the line direction in which the recording electrodes are aligned.

According to the above-mentioned means, by changing the magnitude of the recording voltage applied to the recording electrode adjacent to the recording electrode for discharging the selected ink, the voltage is formed around the recording electrode for discharging the selected ink. The distribution state of the applied electric field intensity changes, whereby the ink ejection direction can be slightly deflected to the line direction in which each recording electrode is aligned. , And a fine high-resolution image can be recorded.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In an embodiment of the present invention, a plurality of recording electrodes are arranged in a line in an electrostatic ink jet recording apparatus, and recording voltages are individually supplied to the plurality of recording electrodes from recording voltage generating means. A recording head for discharging ink from a selected one of the plurality of recording electrodes in accordance with the supplied recording voltage, wherein the recording voltage generating means A recording voltage having one voltage value among the voltage values of the steps is generated, and by adjusting the voltage value of the generated recording voltage, the ink ejected from the selected recording electrode is deflected in the line direction. .

In a specific example of the embodiment of the present invention, in the electrostatic ink jet recording apparatus, the recording voltage generating means may be configured such that a voltage value at which ink is not ejected to each recording electrode adjacent to a selected recording electrode from which ink is ejected. And a recording electrode having the following.

In another specific example of the embodiment of the present invention, in the electrostatic ink jet recording apparatus, the recording voltage generating means is adapted to respond to a recording voltage having one voltage value among multi-stage voltage values. It has a function of adjusting the supply time of the recording voltage.

In still another specific example of the embodiment of the present invention, in the electrostatic ink jet recording apparatus, an array recording head has magnetic field generating means arranged on the ink ejection side of a plurality of recording electrodes.

In one embodiment of the present invention, in the electrostatic ink jet recording apparatus, one of the multi-step voltage values of the recording voltage generated by the recording voltage generating means is used to determine the resolution of the recorded image. Is selected in accordance with.

In another example of the embodiment of the present invention, the electrostatic ink jet recording apparatus is characterized in that one of the multi-step voltage values of the recording voltage generated by the recording voltage generating means is used for recording the recorded image. Is selected in accordance with the gradient of.

According to these embodiments of the present invention, recording of a voltage value recordable on at least one selected recording electrode is performed on a plurality of recording electrodes arranged in a line in an array recording head. By supplying a voltage and supplying a recording voltage of a voltage value that does not reach a recordable voltage value to a recording electrode adjacent to the recording electrode that ejects the selected ink, the periphery of the recording electrode that ejects the selected ink Since the distribution state of the electric field intensity formed in the recording electrode is changed and the direction of ink ejection from the selected recording electrode is slightly deflected to the line direction in which each recording electrode is aligned by the distribution change of the electric field intensity, The formation position of the minute recording dots on the recording paper changes due to the deflection of the ink ejection direction. As a result, it becomes possible to perform high-precision positioning. Using an array-type recording head having a low resolution of the recording electrode array about dpi, it is possible to record a high-resolution definition images of about 900 dpi.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a structural view showing an embodiment of an electrostatic ink jet recording apparatus according to the present invention, and mainly shows a portion related to an array recording head.

In the configuration diagram of FIG. 1, in order to prevent the configuration from becoming complicated, only the recording voltage generator for one recording electrode is shown, and the description of the recording voltage generator for the other recording electrodes is omitted. ing.

[0020] In FIG. 1, 1 is a recording electrode, 2 is a recording head unit, 3 a recording voltage generating unit, 3 ₁ the first recording voltage generator for generating a voltage value V0, 3 ₂ generates a voltage value V1 second recording voltage generator, 3 ₃ 3 for generating a voltage value V2
Recording voltage generator, 4 is a data conversion unit, 5 is a data input unit, 6 is a paper feed roller, 6A is a drive roller, 6B
Is an opposing roller, 7 is a stepping pulse motor, 8
Denotes a counter electrode, 9 denotes a recording sheet, 10 denotes an array-shaped recording head, 11A denotes ink particles, 11B denotes ink recording dots, and arrow F denotes a flow of ink.

The array recording head 10 is formed by arranging a plurality of recording heads 2 in a line, and each recording head 2 has a recording electrode 1 whose tip protrudes in the direction of the counter electrode 8. Be placed. Recording voltage generator 3, the first recording voltage generator 3 ₁ that are cascade-connected, the second recording voltage generator 3 ₂ has become the third recording voltage generator 3 _3, recording electrodes 1 are output corresponding Connected to. Note that the recording voltage generator 3 is provided separately for each recording electrode 1, and here only one is shown and other components are not shown. Data converter 4 has an input connected to the data input unit 5, the output is the first recording voltage generator 3 _1, second recording voltage generator 3 ₂ are connected to the third recording voltage generator 3 _3. The paper feed roller 6 includes a drive roller 6A.
The driving roller 6A is coupled to the stepping pulse motor 7 and sends out the recording paper 9 stepwise during recording. The counter electrode 8 is formed of each recording electrode 1.
Is provided at a position facing the tip of the recording electrode 1, and is usually grounded, and the opposing electrode 8 between each recording electrode 1 and the opposing electrode 8 is provided.
The recording paper 9 is placed and transported thereon. The ink flows in the direction of arrow F, and ink droplets 11A are ejected from the recording electrodes 1 in the direction of the recording paper 9 during recording to form ink recording dots 11B on the recording paper 9.

FIG. 2 is a partial configuration diagram showing a configuration of a generation portion of a recording voltage of each voltage value supplied to the recording electrode 1.

[0023] In FIG. 2, S0 the first recording voltage generator 3 ₁ of the drive signal, the second recording voltage generator 3 ₂ of the drive signal S1, the third drive signal of the recording voltage generator 3 ₃ S2, V0
First recording voltage generator 3 ₁ of the output voltage (for example, 0.5k
V), V1 is the second recording voltage generator 3 _{and second} output voltage (e.g. 1.65kV), V2 is the third recording voltage generator 3 _third output voltage (e.g. 0.4 Voltage kV), Other, Figure 1
The same reference numerals are given to the same components as those shown in FIG.

Each recording head unit 2 ejects ink when the recording voltage Vp supplied to the recording electrode 1 becomes, for example, 1.8 kV or more, and generates air discharge when it becomes 3 kV or more. Therefore, the recording voltage Vp is 0 kV <Vp <1.8.
When it is at kV, it is called a bias voltage, and 1.8 kV <Vp
When it is at <3.0 kV, it is called a flying voltage. In addition,
The relationship between these voltages changes depending on the shape of the recording electrode 1, the distance between the recording electrode 1 and the recording paper 9, and the like.

The operation of the electrostatic ink jet recording apparatus according to this embodiment having the above configuration will be described with reference to FIGS.

First, in the array-shaped recording head 10, the ink always flows in the direction of the arrow F in each recording head unit 2 by the action of the ink supply means and the ink discharge means (not shown). Immediately before reaching the tip of the recording electrode 1, the pigment particles in the ink are positively charged by passing over a charging electrode (not shown) arranged near the tip of the recording electrode 1.

[0027] Now, when the drive signal S0 from the data converter 4 is supplied to the first recording voltage generator 3 _1, the first recording voltage generator 3 ₁ generates a recording voltage of the voltage value V0, the data conversion unit When the drive signal S1 from 4 is supplied to the second recording voltage generator 3 _2, second recording voltage generator 3 ₂ generates a recording voltage of the voltage value V1, the drive signal S2 from the data converter 4 is a third When supplied to the recording voltage generator 3 _3, recording a third recording voltage generator 3 ₃ generates a recording voltage of the voltage value V2, the generated voltage as the output recorded voltage of the recording voltage generating unit 3, the corresponding It is supplied to the electrode 1. At the same time a drive signal S0 from the data converter 4 is supplied to the first recording voltage generator 3 _1, when the driving signal S1 is supplied to the second recording voltage generator 3 _2, the first recording voltage generator 3 ₁ second recording voltage generator 3 ₂ generates a recording voltage of the voltage value V1 with generating a write voltage of the voltage value V0, the voltage value of the sum of the recording voltage generating unit 3 from the two voltage values V0, V1 A voltage of (V0 + V1) is generated, and this voltage is supplied to the corresponding recording electrode 1 as a recording voltage. Similarly, the data conversion unit 1 4 from the drive signal S0 is the recording voltage generator 3 _1, the drive signal S1
To but ₂ second recording voltage generator 3, the drive signal S2 is simultaneously supplied respectively to the third recording voltage generator 3 _3, the first recording voltage generator 3 ₁ a recording voltage of the voltage value V0, the second the recording voltage of the recording voltage generator 3 ₂ the voltage value V1, the third recording voltage generator 3 ₃ generates a recording voltage of the voltage value V2, respectively, the recording voltage generator 3 three voltage from value V0, V1, V
A voltage of the sum of the two (V0 + V1 + V2),
This voltage is supplied to the corresponding recording electrode 1 as a recording voltage.

In this case, as shown in FIG. 2, no recording voltage is supplied to the recording electrode 1 during non-recording, but during recording, Vp1 = V0 (0.5 kV), Vp2
= V1 (1.6 kV), Vp3 = V1 + V2 (2.1 kV)
V), Vp4 = V0 + V1 + V2 (2.5 kV). When the recording voltage is Vp1, only a weak bias electric field is formed between the recording electrode 1 and the opposing electrode 8 opposed thereto, and the ink particles 11A do not fly from the tip of the recording electrode 1, and the recording voltage is reduced. When the voltage value of Vp2 is Vp2, a strong bias electric field is formed between the recording electrode 1 and the counter electrode 8, but the intensity is not enough electric field to eject ink. The ink particles 11A do not fly, and no ink recording dots 11B are formed on the recording paper 9, respectively. On the other hand, when the voltage value of the recording voltage is Vp3, an electric field having a strength sufficient to eject ink between the recording electrode 1 and the counter electrode 8 is formed, and the ink aggregated at the tip of the recording electrode 1 is formed. Flies weakly as ink particles 11A, and when the voltage value of the recording voltage is Vp4, an electric field of sufficient strength is formed by ejecting ink between the recording electrode 1 and the counter electrode 8, and the tip of the recording electrode 1 The ink agglomerated in the step flies strongly as ink particles 11A, and the ink recording dots 11 on the recording paper 9 respectively.
B is formed.

At this time, the recording paper 9 is held between the paper feed rollers 6 and is intermittently fed by the rotation of the drive source roller 6B accompanying the rotation of the stepping pulse motor 7, so that a large number of ink recording dots 11B are formed on the recording paper 9. Are collected and the required image formed is recorded. Although the recording paper 9 on which the required image is recorded can be used as it is, it is passed through a normal heat fixing device used in an electrophotographic recording device (not shown) to fix the ink recording dots 11B. It may be used.

The data input section 5 receives image data to be recorded by the electrostatic ink jet recording apparatus. The data conversion unit 4 converts the image data taken in by the data input unit 5 into individual drive signals S0, S1, S2 corresponding to the image data.
2, and outputs a paper feed control signal for driving the pulse motor 7 at the same time. The data input unit 5
In, the resolution and the number of tones per dot can be designated and input for each area of the image recorded on the recording paper 9.

The array recording head 10 of the electrostatic ink jet recording apparatus according to the present embodiment has a configuration in which the arrangement density of the recording electrodes 1 corresponds to a resolution of 300 dpi (dots / inch). Head 10
Is used to record an image in which the arrangement density of the recording electrodes 1 is equivalent to a resolution of 900 dpi.
A procedure for performing such image recording will be described.

First, the stepping pulse motor 7
The ink recording dots 11B formed on the recording paper 9 can be positioned with high precision, and rotate intermittently according to the polarity and supply state of the supplied pulsed paper feed control signal. At this time, when a one-pulse sheet feed control signal is supplied, for example, the recording sheet 9 is fed by 1/900 inch (28 μm).

The pulse period of the sheet feed control signal is represented by Pt.
(Sec), the paper feed speed V of the recording paper 9 becomes
V = (28 / Pf) × 10 ⁻³ (mm / sec)

FIG. 3 shows the feed speed of the recording paper 9,
The voltage value of the recording voltage supplied to the recording electrode 1 (flying voltage)
FIG. 9 is an explanatory diagram showing a change state of the shape of the ink recording dots 11B obtained when the application time (flying voltage time width) is changed. In this case, the feed speed of the recording paper 9 is V and 3V.
And the recording voltage is Vp3 (2.1 kV),
Vp4 (2.5 kV) and four types of recording voltage application time (T, 2T, 4T, and 9T. The feeding direction of the recording paper 9 is the y direction, and the direction perpendicular thereto is the x direction. I do.

As shown in FIG. 3, as the flying voltage time width is sequentially increased, the shape of the ink recording dot 11B becomes longer in the y direction in proportion to the flying voltage time width. When the flying voltage is increased from Vp3 (a state in which the ink particles 11A fly weakly) to Vp4 (a state in which the ink particles 11A fly strongly), the shape of the ink recording dots 11B mainly becomes longer in the x direction. When the paper feed speed is increased from V to 3V, the shape of the ink recording dots 11B mainly increases in the length in the y direction and decreases in the x direction at the same time.

From these facts, if any one or more of the feed speed V, the flying voltage Vp and the flying voltage time width T of the recording paper 9 are changed, the shape, that is, the size, the length and the width are changed. Vp = Vp3 in the electrostatic ink jet recording apparatus of this embodiment.
(2.1 kV), T = 500 μsec, V = 57 mm /
In this case, an ink recording dot 11B having a minimum value of 28 μmφ can be obtained, and Vp = Vp4 (2.5
kV), T = 4500 μsec, V = 19 mm / sec
, The maximum value of the ink recording dots 11B is 8
5 μmφ is obtained.

When it is desired to increase the size of the ink recording dots 11B, the ink recording dots 11B are formed on the recording paper 9 by ordinary means, and then the recording paper 9 is applied to a heat and pressure roll. The upper ink recording dots 11B may be crushed and expanded, and a normal heat fixing device for an electrophotographic recording apparatus is used for the heat and pressure roll at this time.

FIGS. 4A and 4B are explanatory views showing the operation state when the ink recording dots 11B are formed on the recording paper 9 in the electrostatic ink jet recording apparatus of this embodiment. (A) is a large ink recording dot 11B.
(B) shows the state at the time of forming a small ink recording dot 11B (28 μmφ).

In FIGS. 4A and 4B, for convenience of explanation, each recording electrode 1 is denoted by 1A, 1B, 1
C, 1D, 1E and 1F, and the recording electrodes 1A, 1B and 1
C, 1D, 1E and 1F respectively have recording voltages Vp2 and Vp
3, Vp2, Vp3, Vp3, and Vp3.
Also, regarding the equipotential lines, each of the recording electrodes 1A, 1B, 1
Only those formed in spaces near C, 1D, 1E, and 1F are shown.

4A and 4B, the recording electrode 1
The equipotential lines formed in the space in the vicinity of B indicate the recording voltage V that does not eject ink to the adjacent recording electrodes 1A and 1C, respectively.
Since p2 is applied and the recording electrode 1B is formed symmetrically in the line direction, the ink particles 11A ejected from the recording electrode 1B fly straight toward the recording paper 9. On the other hand, in the equipotential line formed in the space near the recording electrode 1D, a recording voltage Vp2 that does not eject ink is applied to the recording electrode 1C on the left of the adjacent recording electrodes 1C and 1E, and the recording electrode Recording electrode V that ejects ink to 1E
Since p3 is applied and is formed asymmetrically in the line direction with respect to the recording electrode 1D, the ink particles 11A ejected from the recording electrode 1D fly so as to be drawn in the direction of the recording electrode 1C. As a result, the ink recording dots 11B formed by the recording electrodes 1D are recorded at a position shifted by about 28 μm in the direction of the recording electrodes 1C from the original recording position on the recording paper 9 regardless of the size. Therefore, the electrostatic ink jet recording apparatus of the present embodiment utilizes such interference between two adjacent recording electrodes 1C-1D and 1D-1E to achieve high-resolution recording with a maximum resolution of about 900 dpi. It is assumed that.

FIG. 5 and FIG. 6 are explanatory views of the operation of the electrostatic ink jet recording apparatus of the present embodiment when performing high-resolution recording at a maximum resolution of about 900 dpi.
FIG. 6 shows an operation state during recording at a resolution of 900 dpi, and FIG. 6 shows an operation state during recording at a resolution of 636 dpi.

FIG. 5 and FIG. 6 are explanatory diagrams of the operation in the case where high-resolution printing with a maximum resolution of about 900 dpi is performed in the electrostatic ink jet printing apparatus of this embodiment.
FIG. 6 shows an operation state at the time of recording at a resolution of 900 dpi, and FIG. 6 shows an operation state at the time of recording at a resolution of 450 dpi.

In FIGS. 5 and 6, a, b,...
, O are formation positions of the ink recording dots 11B (hereinafter, referred to as dot positions).
The same components as those shown in (b) are denoted by the same reference numerals.

As shown in FIG. 5, the resolution is 900 dp.
When recording i, small ink recording dots 11B
The voltage value of the recording voltage Vp and the application time are set so that (28 μmφ) is formed, and the recording voltage Vp2 is applied to the recording electrodes 1A to 1F before recording.
First, as shown in the first row of the table, a recording voltage Vp2 is applied to each of the recording electrodes 1A, 1C, and 1E, and a recording voltage Vp3 is applied to each of the recording electrodes 1B, 1D, and 1F. Since the recording electrodes 1A, 1C, and 1E arranged adjacent to both sides of each of the recording electrodes 1B, 1D, and 1F that discharge the ink are all at the recording voltage Vp2, the ink particles 11A fly straight toward the recording paper 9, The ink recording dots 11B are formed at every sixth dot position b, h, n.
Next, as shown in the second row of the table, each recording electrode 1A, 1E
And the recording voltage Vp1 is applied to the recording electrode 1C.
When p2 is applied and a recording voltage Vp3 is applied to each of the recording electrodes 1B, 1D, and 1F, each of the recording electrodes 1 that ejects ink is discharged.
B, 1D, 1F, each recording electrode 1 arranged adjacent to both sides
Since the recording voltages Vp1 and Vp2 applied to the recording electrodes A, 1C, and 1E are different, the ink droplet 11A flies while being shifted in the direction of the recording electrodes 1A and 1E to which the small recording voltage Vp1 is supplied, and has dot positions a and i. , M are formed with ink recording dots 11B. Next, as shown in the third row of the table, the recording voltage Vp1 was applied to the recording electrode 1C, the recording voltage Vp2 was applied to each of the recording electrodes 1A and 1E,
When the recording voltage Vp3 is applied to B, 1D, and 1F, ink recording dots 11B are formed at dot positions c, g, and o in the same manner as in the previous case, and then, as shown in the fourth row of the table. The recording voltage Vp2 is applied to each of the recording electrodes 1A, 1B, 1D and 1F, and the recording voltage Vp is applied to each of the recording electrodes 1C and 1E.
When p3 is applied, ink recording dots 11B are similarly formed at dot positions e and k. Further, as shown in the fifth row of the table, a recording voltage Vp1 is applied to each of the recording electrodes 1B and 1F, a recording voltage Vp2 is applied to each of the recording electrodes 1A and 1D, and a recording voltage Vp3 is applied to each of the recording electrodes 1C and 1E. Is applied, ink recording dots 11B are formed at dot positions d and i. Then, as shown in the sixth row of the table, a recording voltage Vp1 is applied to the recording electrodes 1D, and the recording electrodes 1A, 1B, and 1F are applied.
When the recording voltage Vp2 is applied to the recording electrodes 1C and 1E and the recording voltage Vp3 is applied to the recording electrodes 1C and 1E, the ink recording dots 11B are formed at the dot positions f and j. When the recording up to this point is performed, the recording for one line is completed. Immediately after the recording for one line is completed, a paper feed control signal is supplied, and the recording paper 9 is moved by a distance of 28 μm for one line at a resolution of 900 dpi. Let me go ahead. During this time, one pulse of the sheet feed control signal is 500 × 6 = 3000 μsec, so that the recording speed under so-called worst conditions when recording on the entire surface of the recording sheet 9 is V = 9.3 mm / sec, and recording with a resolution of 300 dpi is performed. It is half the speed of the hour.

According to the electrostatic ink jet recording apparatus of this embodiment, by causing interference of the electric field between the recording electrodes 1A to 1F, the recording with the resolution of 900 dpi is performed by using the array recording head 10 having the limit of 300 dpi. Can be performed.

The recording electrodes 1A disposed at both ends of the array recording head 2 do not fly ink because there is no recording electrode adjacent to one side.

Also, as shown in FIG.
When recording at 0 dpi, the ink recording dots 11B suitable for recording at a resolution of 450 dpi are used as in the previous case.
The voltage value of the recording voltage Vp and the application time are set so that is formed, and the recording voltage Vp2 is applied to the recording electrodes 1A to 1F before recording. First, as shown in the first row of the table, each recording electrode 1A,
When the recording voltage Vp1 is applied to 1E, the recording voltage Vp2 is applied to the recording electrode 1C, and the recording voltage Vp3 is applied to each of the recording electrodes 1B, 1D, and 1F, both sides of each of the recording electrodes 1B, 1D, and 1F that eject ink are ejected. Recording electrodes 1 arranged adjacent to each other
Since the recording voltages Vp1 and Vp2 applied to the recording electrodes A, 1C, and 1E are different, the ink droplet 11A flies while being shifted in the direction of the recording electrodes 1A and 1E to which the small recording voltage Vp1 is supplied, and has dot positions a and i. , M are formed with ink recording dots 11B. Next, as shown in the second row of the table, the recording voltage Vp1 was applied to the recording electrode 1C,
A, 1E, the recording voltage Vp2 is applied to each of the recording electrodes 1B, 1D,
When the recording voltage Vp3 is applied to the recording electrodes 1F, the recording voltages Vp1 and Vp2 applied to the recording electrodes 1A, 1C, and 1E disposed adjacent to both sides of the recording electrodes 1B, 1D, and 1F for discharging ink, respectively. Therefore, the ink droplet 11A flies with a shift in the direction of the recording electrode 1C to which the small recording voltage Vp1 is supplied, and forms an ink recording dot 11B at dot positions c, g, and o. Next, as shown in the third row of the table, each of the recording electrodes 1A, 1B,
The recording voltage Vp2 is applied to the recording electrodes 1C and 1E.
When the recording voltage Vp3 is respectively applied to the recording medium, the ink recording dots 11B are formed at the dot positions e and k in the same manner as before.

When the recording up to this point is performed, the first recording for one line is completed. Immediately after the recording for this one line is completed, a paper feed control signal is supplied, and
The recording paper 9 is advanced by a distance of 56 μm for one line of 0 dpi.

Thereafter, as shown in the fourth row of the table, a recording voltage Vp1 is applied to the recording electrode 1D, and the recording electrodes 1A, 1B, 1
When the recording voltage Vp2 is applied to F and the recording voltage Vp3 is applied to each of the recording electrodes 1C and 1E, the ink recording dots 11B are formed at the dot positions f and j as in the previous case. As shown in FIG. 3, the recording voltage Vp1 is applied to each of the recording electrodes 1B and 1F, and the recording voltage Vp is applied to each of the recording electrodes 1A and 1D.
When p2 is applied with a recording voltage Vp3 to each of the recording electrodes 1C and 1E, ink recording dots 11B are formed at dot positions d and i. Next, as shown in the sixth row of the table, the recording voltage Vp2 was applied to each of the recording electrodes 1A, 1C, and 1E.
When a recording voltage Vp3 is applied to each of the recording electrodes 1B, 1D, and 1F, ink recording dots 11B are formed at dot positions b, h, and n.

When the recording up to this point is performed, the second recording for one line is completed. Immediately after the recording for one line is completed, a paper feed control signal is supplied, and a resolution of 45 lines is supplied.
The recording paper 9 is advanced by a distance of 56 μm for one line of 0 dpi. The recording speed at this time is a speed under so-called worst conditions when recording is performed on the entire surface of the recording paper 9,
V = 9.3 mm / sec, which is half the speed at the time of recording at a resolution of 300 dpi.

According to the electrostatic ink jet recording apparatus of this embodiment, as in the case of recording at a resolution of 900 dpi, interference of the electric field between the recording electrodes 1A to 1F is caused, thereby making it possible to perform array recording at a resolution of 300 dpi. Head 1
Using 0, recording with a resolution of 450 dpi can be performed.

When recording at a resolution of 636 dpi, ink recording dots 11B are formed in the first, second, and third rows of the table shown in FIG. 6, and immediately after that, a paper feed control signal is transmitted. Then, the recording paper 9 is advanced by a distance of 28 μm for one line at a resolution of 900 dpi, and subsequently, the fourth and fifth rows of the table shown in FIG.
The ink recording dots 11B are formed in the sixth row, and immediately after that, a paper feed control signal is supplied to the recording section 11B.
Recording paper 9 for a distance of 28 μm for one line of 00 dpi
Is advanced, a resolution of 450 dpi is used by using the array recording head 10 having a limit of 300 dpi.
i can be recorded.

As described above, by using the recording means as shown in FIGS.
Recording with a resolution other than 36 dpi and 450 dpi can be performed.

FIG. 7 is an explanatory diagram showing the relationship between the ink recording dot shape, the dot center interval, the resolution, and the recording speed.

As shown in FIG. 7, the resolution is 900 dp.
Ink recording dots of i have a dot center interval of 28 μm
The ink recording dots having a resolution of 636 dpi obtained at a recording speed of 9.3 mm / sec are obtained when the dot center interval is 40 μm and the recording speed is 9.3 mm / sec, and the ink recording dots having a resolution of 450 dpi are obtained. Dots are
The dot center interval is 56 μm and the recording speed is 9.3 mm /
The ink recording dots having a resolution of 318 dpi are obtained when the dot center interval is 80 μm, the recording speed is 9.3 mm / sec, and the resolution is 300 dpi.
The ink recording dots of i have a dot center interval of 85 μm
And is obtained when the recording speed is 18.7 mm / sec.
Ink recording dots with a resolution of 212 dpi have a dot center interval of 120 μm and a recording speed of 18.7 mm / sec.
Obtained when.

FIG. 8 is a diagram showing a main part of another embodiment of the electrostatic ink jet recording apparatus according to the present invention. In addition to applying the recording voltage Vp to each recording electrode 1, each recording is performed. A strong electric field is formed in the vicinity of the electrode 1 to cause ink to fly in an arbitrary direction.

In FIG. 8, reference numeral 12 denotes an electromagnet, reference numeral 13 denotes an electromagnet drive circuit, and other components which are the same as those shown in FIG. 1 are denoted by the same reference numerals.

The electromagnet 12 is provided between each recording electrode 1 and the opposing electrode 8. The energizing of the excitation winding of the electromagnet 12 by the electromagnet driving circuit 13 causes the electromagnet 12 to move between the recording electrode 1 and the opposing electrode 8. A strong magnetic field B is generated in the space between them.

In this embodiment, an array-type recording head 10 in which the distance between the recording electrodes 1 is large and there is no electric field interference between the recording electrodes 1 is used. In the space where the ink droplet 11A flies, the electromagnet 1
2 form a strong magnetic field B. Magnetic field B
When the switch of the electromagnet drive circuit 13 is switched, the direction of the exciting current I flowing through the exciting winding of the electromagnet 12 changes, so that the direction can be changed with the switching of the direction of the exciting current I. At this time, the flying ink particles 11
A is a positively charged magnetic field, as shown in FIG.
When flying inside, the ink droplet 11A that flies,
In addition to the force Fe caused by the electric field, a Lorentz force Fb acts,
The position of the ink recording dot 11B is shifted downward in FIG. This shift amount can be controlled by changing the strength of the magnetic field B, that is, the magnitude of the exciting current I.

In the recording according to the present embodiment, first, the ink particles 11A are ejected from the recording electrode 1 without forming the magnetic field B.
Next, while appropriately controlling the direction and magnitude of the magnetic field B, the magnetic field B is ejected from the recording electrode 1 one or more times.

According to the present embodiment, the resolution higher than the resolution of the array recording head 10 is obtained by using the array recording head 10 in which the distance between the recording electrodes 1 is wide enough to prevent interference of the electric field between the recording electrodes 1. High-definition recording can be performed.

In each of the above embodiments, the array recording head 10 has been described as having a width of one line, but the array recording head 10 used in the present invention is described.
Need not necessarily have a width of one line, and may have a width smaller than the width of one line.

[0063]

As described above, according to the present invention, for a plurality of recording electrodes arranged in a line in an array recording head, a voltage value recordable on at least one selected recording electrode is selected. By supplying a recording voltage and supplying a recording voltage having a voltage value that does not reach a recordable voltage value to a recording electrode adjacent to the recording electrode that ejects the selected ink, the recording electrode that ejects the selected ink is discharged. Since the distribution state of the electric field strength formed around is changed, and the ink ejection direction from the selected recording electrode is slightly deflected to the line direction in which each recording electrode is aligned by the change in the distribution of the electric field strength. The formation position of minute recording dots on the recording paper changes due to the deflection of the ink ejection direction,
As a result, high-precision positioning can be performed, and there is an effect that a high-resolution fine image of about 900 dpi can be recorded by using an array recording head having a low-resolution recording electrode array of about 300 dpi. .

[Brief description of the drawings]

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

FIG. 2 is a partial configuration diagram showing a configuration of a generation portion of a recording voltage of each voltage value supplied to a recording electrode in the embodiment shown in FIG.

FIG. 3 is an explanatory diagram showing a change state of a shape of an ink recording dot obtained when a feeding speed of a recording sheet, a flying voltage supplied to a recording electrode, and a flying voltage time width are changed.

FIG. 4 is an explanatory diagram showing an operation state when forming ink recording dots on recording paper in the embodiment shown in FIG. 1;

FIG. 5 shows a maximum resolution of 90 in the embodiment shown in FIG.
FIG. 9 is an explanatory diagram of the operation when performing high-resolution recording of about 0 dpi. FIG. 6 shows an operation state at the time of recording at a resolution of 636 dpi.

FIG. 6 shows a resolution of 450 d in the embodiment shown in FIG.
FIG. 4 is an operation explanatory diagram when performing high-resolution recording of about pi.

FIG. 7 is an explanatory diagram showing a relationship between an ink recording dot shape, a dot center interval, a resolution, and a recording speed.

FIG. 8 is a main part configuration diagram showing another embodiment of the electrostatic ink jet recording apparatus according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Recording electrode 2 Recording head part 3 Recording voltage generation part 3 ₁ First recording voltage generator which generates voltage value V0 3 ₂ Second recording voltage generator which generates voltage value V1 33 _3rd which generates voltage value V2 Recording voltage generator 4 Data conversion unit 5 Data input unit 6 Paper feed roller 6A Drive roller 6B Counter roller 7 Stepping pulse motor 8 Counter electrode 9 Recording paper 10 Array recording head 11A Ink droplet 1B Ink recording dot 12 Electromagnet 13 Electromagnetic drive circuit

Claims (6)

[Claims] A plurality of recording electrodes arranged in a line;
A recording voltage is separately supplied from the recording voltage generating means to the plurality of recording electrodes, and ink is ejected from a selected recording electrode among the plurality of recording electrodes in accordance with the supplied recording voltage. In an electrostatic ink jet recording apparatus provided with a head, the recording voltage generating means generates a recording voltage having one voltage value among multi-stage voltage values on the plurality of recording electrodes, and a voltage of the generated recording voltage. An electrostatic ink jet recording apparatus, wherein the ink ejected from the selected recording electrode is deflected in the line direction by adjusting a value. 2. The method according to claim 1, wherein the recording voltage generator supplies a recording electrode having a voltage value that does not cause the ink to be ejected to each of the recording electrodes adjacent to the selected recording electrode that causes the ink to be ejected. Item 2. An electrostatic inkjet recording apparatus according to Item 1. 3. The recording voltage generating means according to claim 1, wherein said recording voltage has one voltage value among said multi-level voltage values.
2. The electrostatic inkjet recording apparatus according to claim 1, further comprising a function of adjusting the supply time of the recording voltage. 4. The electrostatic ink jet recording apparatus according to claim 1, wherein the array recording head has a magnetic field generating means arranged on an ink ejection side of the plurality of recording electrodes. 5. A printing method according to claim 1, wherein one of the multi-step voltage values of the recording voltage generated by said recording voltage generating means is selected in accordance with the resolution of a recording image. 5. The electrostatic inkjet recording apparatus according to 4. 6. A method according to claim 1, wherein one of the multi-step voltage values of the recording voltage generated by said recording voltage generating means is selected in accordance with the gradation of a recording image. 5. The electrostatic inkjet recording device according to any one of items 1 to 4.