JP2001088290A - Recorder and driving method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate halftoning in a pixel in recording and to eject ink surely in reproducing an image of high image quality in a short time. SOLUTION: In a recorder and a recording method for recording a recording body 13 by ejecting recording liquid held in a group of columnar bodies 6 or flying vaporaized recording liquid, the transfer part 1 of the recording liquid is connected with means 30, 31 for controlling the flying energy by controlling the pulse voltage, pulse time or pulse interval depending on the magnitude of capillarity of the group of columnar bodies 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus (especially a printer head) for flying a recording liquid held in a capillary structure by heating with a resistance heating means or the like to perform recording on a recording medium, and a driving method thereof. It is.

[0002]

2. Description of the Related Art In recent years, as colorization of video cameras, computer graphics, and the like has progressed, the need for colorization of hard copies as well as monocolor recording has increased.

[0003] A color image processed by a personal computer or the like, or a color image picked up by a video camera, an electronic still camera, or the like is printed out for viewing and other purposes. For this reason, there is a growing need for a printer capable of obtaining high-quality full-color images. In particular, relatively inexpensive printers for individuals and small offices called, for example, "small offices" or "home offices" have been developed. Again,
It is beginning to be required to obtain high-quality full-color images.

In response to this, color hard copy systems such as a sublimation type thermal transfer system, a melt thermal transfer system, an ink jet system, an electrophotographic system, and a thermally developed silver salt system have been proposed. Among these methods, methods for easily outputting high-quality images with a simple device can be broadly classified into a dye diffusion thermal transfer method (sublimation type thermal transfer method) and an ink jet method.

[0005] Among these recording methods, the dye diffusion thermal transfer method refers to an ink ribbon or sheet coated with an ink layer in which a high-concentration transfer dye is dispersed in an appropriate binder resin. A transfer medium such as photographic paper coated with a dye-resin that accepts a dye is brought into close contact with a given pressure, and heat is applied in accordance with image information from a thermal recording head located on the ink sheet. In this method, the transfer dye is thermally transferred according to the amount of heat applied to the dye receiving layer.

The above method is repeated for image signals decomposed into three subtractive primary colors, yellow, magenta, and cyan, thereby obtaining a full-color image having continuous gradation. The so-called dye diffusion thermal transfer method has attracted attention as an excellent technology for easily miniaturizing and maintaining, having immediacy, and obtaining high-quality images comparable to silver halide color photographs.

However, this method is disadvantageous in that a large amount of waste is generated due to disposable ink sheets and high running cost is a major drawback. This is the same in the fusion heat transfer system.

As described above, the conventional thermal transfer system has high image quality, but has a high running cost due to the use of a dedicated photographic paper and a disposable ink ribbon or sheet.

On the other hand, those known as ink jet systems are disclosed in JP-B-61-59911 and JP-B-5-5-2.
As disclosed in Japanese Patent Application Publication No. 17-173, small droplets of a recording liquid are applied to a recording head by a method such as an electrostatic attraction method, a continuous vibration generation method (piezo method), or a thermal method (bubble jet method) according to image information. The recording is performed by flying from a provided nozzle and attaching to a recording member.

Therefore, transfer of plain paper is possible, and there is almost no waste when using the ink ribbon, and the running cost is low. Recently, the thermal method has been widely used because it can easily output a color image.

However, in the ink-jet method, the density gradation in a pixel is difficult in principle, and a high-quality image comparable to a silver halide photograph, which can be obtained by a dye diffusion thermal transfer method, can be reproduced in a short time. It is difficult.

That is, in the conventional ink jet recording, since one droplet of ink forms one pixel, gradation in a pixel is difficult in principle, and a high quality image cannot be formed. Nevertheless, attempts have been made to express the pseudo gradation by the dither method using the high resolution of the ink jet, but the image quality equivalent to that of the sublimation type thermal transfer system cannot be obtained, and the transfer speed has been significantly reduced.

In order to solve these problems, a method using a so-called mist has been proposed in the ink jet recording system in order to miniaturize the discharged droplet. These are roughly classified into two types, the ultrasonic vibration method and the satellite droplet use method.

In the ultrasonic vibration method, ultrasonic vibrations are mainly generated using a piezoelectric vibrator in a discharge portion, and fine droplets (ink mist) generated by collision of ink liquids due to surface tension vibrations generated by the ultrasonic vibrations. ) Is transferred.

[0015] The satellite droplet use method uses minute droplets which are generated immediately after the main droplet is formed for image formation, and the main droplet is not used for image formation. .

However, in the ultrasonic vibration method, there is a problem common to piezo elements in that it is difficult to miniaturize a piezo element which is generally used, and furthermore, it is difficult to form a line head, so that the printing speed is low. Further, since it is difficult to localize the ultrasonic vibration, further miniaturization of the mist is difficult, and the adverse effect of crosstalk is great.

The method of using satellite droplets requires means such as charging and bending in an electric field in order to prevent the main droplets from being transferred to the recording paper. Such a method is actually limited to a so-called continuous type ink jet recording method and cannot be realized at low cost.

A so-called dye vaporization or ejection type thermal transfer system has been proposed as a printing system which can solve such a problem and can easily realize the density gradation in the pixel (for example, Japanese Patent Application Laid-Open No. 9-183239). Gazette).

In the dye vaporization or ejection type thermal transfer system, the ink is heated in a transfer portion of a printer head to fly or eject the ink by vaporization, ablation (ablation), surface tension wave, or the like. For example, 5
The transfer is performed by adhering to a surface of a transfer-receiving body (printing paper) such as a printer paper or the like, which is opposed to the apparatus via a gap of about 0 to 100 μm.

The transfer portion has a width or a diameter of 2 μm, for example.
m and a height of about 6 μm.
An ink holding structure is provided by an uneven structure (capillary structure) which is arranged upright at minute intervals, and a heater is provided below the ink holding structure to form a vaporizing section (transfer section). ing.

[0021]

According to the recording apparatus of the dye vaporization or ejection type thermal transfer system, the portion for ejecting or vaporizing the ink includes a portion where the ink liquid layer contacts the atmosphere to form a meniscus, A heater is provided on the substrate side, and a capillary structure is formed from above the heater toward the ink liquid layer.

In this recording apparatus, heater heating is performed,
When heat is transmitted to the ink liquid surface (the surface where the ink comes into contact with the outside air), for example, the surface tension of the portion is reduced and the portion is pulled to the surrounding portion where the surface tension is large, and so-called surface tension convection occurs. As a result, the ink flows out from just above the heater by convection, and eventually dries up if heating is continued.
Therefore, in order to continuously perform the discharge, the heating must be performed intermittently.

Under these circumstances, depending on the shape and size of the capillary structure, the retention of ink and the speed at which the escaped ink returns vary in various ways, so that reliable ejection may not be performed.

Accordingly, an object of the present invention is to provide a recording apparatus which can always reliably discharge or vaporize according to a capillary structure while utilizing the features of the above-described dye vaporization or discharge type thermal transfer system, and to provide a driving method thereof. is there.

[0025]

That is, the present invention relates to a recording apparatus and a driving method for performing recording on a recording medium by flying a recording liquid held in a capillary structure. A flying energy control means for controlling the flying energy of the recording liquid in accordance with the magnitude of the capillary force of the capillary structure, and a driving method thereof. .

According to the recording apparatus and the driving method of the present invention, the recording is performed on the recording medium by flying the recording liquid held in the capillary structure. The tone can be easily adjusted, and a high-quality image can be reproduced in a short time. Moreover, since the flying energy of the recording liquid is controlled in accordance with the magnitude of the capillary force of the capillary structure, for example, in a capillary structure having a large capillary force, the retention of the recording liquid and the returning speed of the escaped recording liquid are large. In addition, a high flying energy can be applied, and conversely, if the capillary structure has a small capillary force, a relatively low flying energy can be applied. As a result, stable discharge or vaporization can always be performed according to the capillary structure.

In the present invention, the term "flying" refers to vaporization, evaporation, ablation (ablation), and bubbles (microbubbles) generated in the recording liquid when heated by resistance heating means (that is, the high resistance portion) or the like. ) Or a surface tension wave {impact force of ink due to surface tension convection (Marangoni flow) of the recording liquid caused by heating}, which means discharging the recording liquid in a gaseous or mist form (hereinafter, referred to as “discharge”). Similar).

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a recording apparatus and a method of driving the same according to the present invention, the recording liquid is discharged or vaporized by the energy of a heater, and the recording liquid for driving the heater is controlled in accordance with the magnitude of the capillary force. Preferably, at least one of the magnitude or width of the pulse voltage or pulse current and the pulse interval is adjusted. In this case, the pulse voltage or the pulse current may be increased or the pulse interval may be reduced as the capillary force increases. Conversely, when the capillary force is small, the pulse voltage or the pulse current may be reduced, or the pulse interval may be increased.

When the electric power of the heater is P (unit: mW),
The pulse interval is Δ (unit: μsec), and the interval in the gap of the capillary portion of the capillary structure is d ｛, which is a numerical value excluding the unit (μm). When｝ (1 / d is the capillary force), 110 ≦ P ≦ {125 (1 / d) +85} and 0.2
≦ 1 / d or {−16.25 (1 / d) +21.25} ≦ Δ ≦ 20,
And 0.2 ≦ 1 / d.

The heating of the heater can be controlled by a drive pulse set by a computer.

Further, as the capillary structure, a porous structure is formed by pillars having a size and an interval of 0.1 to 10 μm, respectively. However, the flying portion and 10 to 500
It is preferable to fly to a recording medium opposed to the recording medium with a gap of μm.

Further, the height of the capillary structure is 1 to 1.
20 μm, 0.1 to 5 μm in diameter or side, and 0.
Protrusions having a heat resistance of 1 to 5 μm and a temperature of 300 ° C. or more are formed in 2 to 100 rows and 2
It is desirable to form a porous structure having a pattern arranged in a matrix in a range of up to 100 rows.

Further, the recording liquid consumed in the flying section is continuously supplied to the flying section, and the momentum of the discharged liquid drops during the discharge, and the convection of the recording liquid generated by heating by the heater is reduced. It is preferably caused by momentum.

In this case, the convection of the recording liquid is caused by unevenness of the surface tension of the recording liquid surface due to heating or due to volume expansion of the recording liquid due to boiling of the components of the recording liquid. May be.

The convection of the recording liquid is caused by expansion of the dissolved air in the recording liquid by heating, or by expansion and rupture, or by thermal expansion of the recording liquid, or by the heater or the capillary structure. May be caused by thermal expansion.

Next, a preferred embodiment of the present invention will be described with reference to the drawings.

First, FIG. 4 shows printer heads for 100C (cyan), 100Y (yellow) and 100M (magenta) for performing predetermined recording on the photographic paper 13 fed by the paper feed roller 20, The entirety of the printer according to the present embodiment is represented by the drive circuit board 14 and the like.

The printer heads 100C, 100Y, 10
0M, for example, head 100Y (the same applies to other heads)
As shown in FIG. 5, the printer head 100Y
A transfer section (flying section) heated by a heater according to image information and a recording liquid introduction path for guiding the recording liquid to the transfer section by capillary action on an aluminum head base 16 also serving as a heat sink. Heater chip 17 integrally formed on a silicon substrate, and driver IC
(Integrated circuit) 19 is mounted, and a flexible printed circuit board 20 on which wiring is formed so as to supply a current to each heater in accordance with image data to be transferred is connected.

Here, a recording liquid introduction hole 21 for introducing a recording liquid into the printer head 100Y is formed in the head base 16. A flow path plate 22 is provided on the upper surface of the heater chip 17, and a flow path for providing a recording liquid introduction path is formed inside the flow path plate 22.

The heater chip 17 has a plurality of heaters for heating the recording liquid to cause convection or the like due to surface tension, and applies a signal voltage based on an image signal to each of these heaters and energizes them. Are formed by a lithography process.

Next, FIG. 2 shows an enlarged schematic plan view near the transfer section 1 of the recording apparatus (particularly, a printer head) according to the present embodiment, and FIG. 1 shows an enlarged schematic sectional view near this transfer section. (However, FIG. 1 is a cross-sectional view taken along line II of FIG. 2 and is enlarged about 5 times in the height direction).

As shown in FIG. 1, a printer head 100 according to the present embodiment has, for example, a substrate 9 made of silicon as a base, and a silicon oxide (thickness, for example, 3 μm) as a heat insulating layer 10 on the substrate 9. A polysilicon film is formed via an SiO ₂ ) film. This polysilicon film has a thickness of, for example, 0.15 μm, and has a high resistance portion 2 serving as a heater and, for example, aluminum (Al—Si, Al—C).
low-resistance portions 3b and 3a connected to the common electrode 5 and the individual electrode 4 having a thickness of, for example, 0.6 μm, each of which has a second element added thereto, such as u.
(Or the low resistance portion 3).

The high resistance section 2 and the low resistance sections 3a, 3b
For example, an SiO ₂ layer is formed as a protective film 12 on the polysilicon film to be formed, and the low-resistance portions 3a, 3b
(Or electrode connection holes: the same applies hereinafter) 28a and 28b for opening electrical connection between the electrodes and the individual electrodes 4 and the common electrode 5 are provided.

Further, a connection portion between the electrodes 4 and 5 containing aluminum as a main component and the low-resistance portions 3a and 3b is made of, for example, Ti made of a high melting point metal such as Ti, W or Cr.
(30 nm) / TiON (50 nm) / Ti (70 n
m), a barrier metal layer 11 is formed, which functions to prevent aluminum, which is a main component of the electrodes 4 and 5, from diffusing into polysilicon, which is a main component of the low-resistance portion, and at the same time, Ohmic contact between the low resistance portions 3a and 3b and the electrodes 4 and 5 is realized.

In the present embodiment, as shown in FIG. 1, an SiO ₂ layer 18 having a protective effect for the electrodes 4 and 5 is formed on the entire surface including the protective film 12 and the electrodes 4 and 5. . The partition 7 and the auxiliary wall 8 that surround the transfer unit 1 and define a supply path 15 for supplying ink (not shown) to the transfer unit 1, and an ink holding structure (capillary structure) in the transfer unit 1. Height, for example, 6 μm
Are formed as a part of the SiO ₂ film 18, respectively.

In the printer head 100, when printing is performed by discharging or vaporizing ink, the transfer unit 1, which is a part that discharges or vaporizes the ink,
The ink liquid layer includes a portion that forms a meniscus in contact with the atmosphere and a portion that holds the ink liquid. The heater 2 is disposed on the substrate 9 side, and a columnar body is provided from above the heater 2 toward the ink liquid layer. A capillary structure consisting of 6 is formed,
When the heater is heated, heat is transmitted to the ink liquid surface (the surface where the ink comes into contact with the outside air). Surface tension convection occurs. As a result, the ink starts to fly from directly above the heater 2 due to the convection or the like.

In the ink ejection mechanism, the momentum of the ejected droplet is generated by the momentum of the convection of the ink generated by the heating of the ink by the heater 2. Specifically, the convection of the ink is caused by unevenness of the surface tension of the ink liquid surface due to heating, due to the volume expansion of the ink due to the boiling of the components constituting the ink, or the heating of the dissolved air in the ink. The thermal expansion of the ink, or the thermal expansion of the heater or capillary structure, or a combination of these factors.

However, if the heating is continued, the ink in the transfer section 1 will eventually dry up. Therefore, the heating must be performed intermittently in order to continue the ejection. Under these circumstances, according to the present invention, the higher the capillary force of the above-mentioned capillary structure (that is, the smaller the gap in the capillary portion), the more sufficiently the ink can be held and the speed at which the escaped ink returns is increased. A high energy (high voltage or high current) pulse can be applied to 2 and / or the pulse gap can be shortened. Conversely, when the capillary force of the capillary structure is small (that is, the gap in the capillary portion is large), a relatively low-energy pulse may be applied to the heater 2 and / or the pulse interval may be widened. FIG. 3 shows a driving pulse applied to the heater 2, in accordance with the capillary forces, the pulse voltage (current) T ₃ and the pulse width T _1, to control the pulse interval T _2, more duty (T ₂ / T ₁ ) Also controls the recording liquid ejection state.

In order to perform the heating by the heater 2, that is, the application of the drive pulse, the pulse generation conditions (pulse voltage, pulse width,
(Pulse interval) is set, a drive pulse is generated by the generation circuit 31 under the set conditions, and is applied to the individual electrode 4.

Thus, the recording liquid can always be stably discharged or vaporized in accordance with the capillary force of the capillary structure.

The capillary structure has a height of 1 to 20 μm.
m, diameter or side is 0.1-5 μm, interval is 0.1-5
The protrusions having a heat resistance of 300 μm or more (for example, the columnar body 6) are 2 to 1 μm in the vertical direction and the horizontal direction, respectively.
An example is a porous structure having a pattern arranged in a matrix in the range of 00 rows and 2 to 100 columns.
The magnitude of the capillary force can be controlled by the size (spacing) of the gap between the projections. The larger the spacing, the smaller the capillary force, and the smaller the spacing, the larger the capillary force.

The height of the columnar body 6 is the same as the height from the bottom surface of the recording liquid storage section to the upper surface thereof, that is, the height of the partition wall 7 surrounding the recording liquid storage section for each heater 2. , And the columnar bodies 6 are provided with a minute gap therebetween. Therefore, the porous structure produces a capillary action, and thus the columnar body 6 can hold the recording liquid in the recording liquid storage section. At the same time, when the recording liquid is heated by the heater 2, the surface tension of the recording liquid decreases as the temperature rises. However, the recording liquid can be prevented from escaping from the vicinity of the surface of the heater 2 by the capillary action.
Therefore, at the time of image transfer, a necessary recording liquid is continuously supplied.

The recording liquid used in the image forming method according to the present embodiment is composed of a dye, a solvent, and an additive added as required, and provides transfer sensitivity, heat stability, image quality,
The selection of materials and the ratio of the components are adjusted to optimize the storage stability.

Dyes suitable for the present method have an appropriate vaporization rate, sufficient heat resistance, sufficient solubility in the solvents described below, low toxicity to the human body, and in addition to photographic paper. Any dye can be used as long as it has sufficient storage stability. Specifically, disperse dyes,
Oil-soluble dyes and basic dyes are preferred.

Particularly preferred dyes are described in JP-A-8-2.
44364, JP-A-8-244363, JP-A-8-244
And dicyanostyryl-based yellow dyes, tricyanostyryl-based magenta dyes, anthraquinone-based magenta dyes, and anthraquino-based cyan dyes described in each publication of 244366.

These dyes are purified by any means such as a sublimation purification method, a recrystallization method, a zone melting method, and a column purification method in order to reduce the evaporation residue and prevent the thermal decomposition product from adhering to the recording portion. It is desirable to use it afterwards.

The solvent of the recording liquid suitable for this recording system has a melting point of less than 50 ° C., a boiling point in the range of 150 ° C. to less than 500 ° C., and a thermal decomposition temperature higher than the boiling point. Any compound that has high compatibility, low toxicity to the human body, and is colorless can be used.

Specifically, phthalate esters such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, dioctyl phthalate, diisodecyl phthalate, dibutyl sebacate, dioctyl sebacate, dioctyl adipate, Diisodecyl adipate,
Dibasic acid esters such as dioctyl azelate and dioctyl tetrahydrophthalate; phosphoric acid esters such as tricresyl phosphate and trioctyl phosphate; and plasticizers for plastics such as tributyl acetylcitrate and butylphthalylbutyl glycolate. And the like.

In addition, in order to adjust the physical properties of the recording liquid, if necessary, appropriate additives such as a surfactant, a viscosity modifier and a preservative can be added. However, these additives need to have the same boiling point as the solvent and the dye.

Specifically, fluorinated fatty acid esters, silylated fatty acid esters, silicone oil and the like can be used as the surfactant. Glycerin, tetraethylene glycol and the like can be used as a viscosity modifier.

The recording solution is prepared by dissolving the above dye in an amount of 5% by weight or more, preferably 10% by weight or more, more preferably 20% by weight or more in the above-mentioned solvent. At this time, in order to increase the solubility, two or more dyes may be mixed and used. At the same time, two or more solvents may be used in combination.
Note that additives are added as needed.

Further, photographic paper suitable for this recording method is PP
Plain paper such as C (Plain paper copy) paper, high-quality paper such as art paper, etc. In order to obtain high quality images with particularly high gradation and density, resins that disperse dyes or oil-soluble dyes A special paper prepared by applying polyester, polycarbonate, cellulose acetate, CAB (cellulose acetate butyrate), polyvinyl chloride, or the like on a base paper can also be used.

In order to improve the recording liquid absorption rate, it is effective to add a porous pigment such as silica or alumina. In particular, for high-quality recording, a photographic paper having an image-receiving layer, such as a PET (polyethylene terephthalate) film, to which a porous pigment having a size of 0.1 μm or less is added to maintain a glossiness on a film base. It is excellent in terms of smoothness, coloring, gloss, and recording liquid absorption speed.

In order to improve the storage stability of the obtained image, it is effective to add an additive such as an ultraviolet absorber or a radical quencher into the image receiving layer. It is also effective to laminate a resin film on the substrate.

[0065]

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

First, the capillary structure of the printer head was set under the following conditions. That is, as shown in FIG. 1 (an enlarged view of the discharge portion at the tip of the heater chip 17 and the vicinity thereof), the pitch L is set in the vertical direction in FIG. 1 or the vertical direction in FIG.
With p = 84 μm, a total of 1216 heaters 2 were formed.
At this time, since one heater transfers one dot, 30
A resolution of 0 DPI (Dot per inch) was realized. Incidentally, each heater is formed of polysilicon having a size of 20 .mu.m.times.20 .mu.m, and has an aluminum individual electrode 4 and a common electrode 5 for applying and applying a signal voltage based on an image signal. did.

Here, the discharge portions are separated from each other by a partition wall 7 and a concave portion (recording liquid storage portion) surrounded by the partition wall 7.
, A recording liquid (not shown) was stored. On the heater 2 and on the periphery thereof, fine columnar small pillars 6 were provided as a component of a discharge section as a group of 13 × 13 via an SiO ₂ layer 18 as a protective film. .

A capillary structure comprising the columnar body 6 is provided,
Furthermore, yellow (Y), magenta (M), and cyan (C)
Printer heads 100Y, 100 divided for each color
A line type printer as shown in FIGS. 4 and 5 equipped with M and 100C was used. Each printer head was connected to the head drive circuit board 14 via the flexible harness 20. Printer head 100Y, 100
M and 100C were attached to the printer as shown in FIG. 4, and the distance between the ejection unit and the printing paper 13 was adjusted to be 1.0 mm.

Since each of the printer heads 100Y, 100M and 100C is provided with 1216 heaters 2, the line type printer used here is
It had the ability to print 1216 lines in each scan.

Regarding the preparation of the ink, the yellow ink was prepared by purifying a dye in which the amino group of a dicyanostyryl yellow dye described in JP-A-8-244364 was substituted with an isobutyl group with a column, and then one part of the dye was used. To the mixture, 7 parts of dibutyl sebacate (dye concentration: 12.5% by weight) was added as a solvent, and the mixture was stirred with an ultrasonic stirrer until completely dissolved.

Similarly, after purifying a dye in which the amino group of the tricyanostyryl magenta dye described in JP-A-8-244363 is substituted with a butyl group by a column, 1 part of the dye is added to sebacic acid. 7 parts of dibutyl (dye concentration: 12.5% by weight) was added, and the mixture was stirred with an ultrasonic stirrer until completely dissolved to prepare a magenta ink.

Similarly, after purifying a column in which an amino group of an anthraquinone cyan dye described in JP-A-8-244366 was substituted with an aminohexyl group, 5 parts of dibutyl sebacate was added to 1 part of the dye. (Dye concentration: 16.7% by weight) and stirred with an ultrasonic stirrer until completely dissolved to prepare a cyan ink.

When these inks are introduced into the cartridges of the corresponding printer heads 100, the inks spontaneously pass through the tubes by the capillary force, reach the columnar body 6 of the transfer unit 1 of the printer head 100, and remove the meniscus. Formed. Then, the thickness of the ink liquid surface at the center of the heater 2 became 6 μm. Peach coated paper (manufactured by Nisshinbo Co., Ltd.) having a porous structure of several μm on the surface and using a binder resin having good compatibility with the oil-soluble dye and the solvent was used as the printing paper.

Example 1 In the above-described printer head, the diameter of the columnar body 6 was 2 μm.
m, the interval between the columnar bodies was 2 μm, and the height was 6 μm. Then, the applied power is set to yellow 93.
5 mW, magenta 140 mW, cyan 220 mW,
The pulse time was 15 μsec and the pulse interval was 5 μsec.

By applying this pulse to the heater,
An ink droplet having an average diameter of about 3 μm is ejected from the ejection section, and about 1 μm
It flies over the gap of mm and adheres to the photographic paper placed opposite. The ink adhering to the printing paper was immediately absorbed and developed color. That is, as shown in FIG. 8 and FIG.
Power (for magenta) P = 1 with column spacing d) = 0.5
The discharge was good at 02 mW.

Embodiment 2 In this embodiment, in the above-described printer head, the diameter of the column 6 is 5 μm, the interval between the columns is 5 μm, and the height is 6 μm.
μm. The applied power was 93.5 mW for yellow, 102 mW for magenta, and 220 mW for cyan per heater, the pulse time was 15 μsec, and the pulse interval was 10 μsec.

By applying this pulse to the heater,
An ink droplet having an average diameter of about 3 μm is ejected from the ejection section, and about 1 μm
It flies over the gap of mm and adheres to the photographic paper placed opposite. The ink adhering to the printing paper was immediately absorbed and developed color. That is, as shown in FIG. 8, the power (for magenta) P = 110 mW with the capillary force (1 / column spacing d) = 0.2.
And could be ejected.

Comparative Example 1 In the printer head of Example 1, the pulse time was set to 19
When exactly the same test as in Example 1 was performed except that the pulse interval was set to 1 μsec, the ejection of the ink droplets did not occur. When the ejection portion was observed with a microscope, the capillary structure corresponding to the portion directly above the heater was observed. The ink was dry.

Comparative Example 2 In the printer head of Example 2, the pulse time was set to 15
When exactly the same test as in Example 2 was performed except that the pulse interval was set to 5 μsec, the ejection of the ink droplets did not occur. When the ejection portion was observed with a microscope, the capillary structure corresponding to the portion immediately above the heater was observed. The ink was dry.

Setting of Drive Condition by Capillary Force Next, in the above-described printer head, the heater power P (pulse voltage, unit is mW) or pulse interval Δ
When the change in the ink discharge state due to (unit: μsec) and the capillary force 1 / d (d is the distance between the columnar bodies (the unit of d is μm, but has no unit)) was examined. , FIG. 6 or FIG.

In FIG. 6, the pulse time is set to 15 μs
c, when the pulse interval is fixed at 5 μsec, the area becomes P <P ^* , the power is too small, the ink is not discharged due to insufficient heat generation, and (1 / d) <(1/2) in the other area.
d ^* ), the ink cannot be ejected because the ink cannot be held directly above the heater due to insufficient capillary force, and P> k ₁ (1 / d) in the further region, the power is too large and the ink is heated by Marangoni effect. Escaped from above, unable to eject.

From this, as the ink dischargeable area, P ^* ≦ P ≦ k ₁ (1
/ D) and 1 / d ≧ 1 / d ^* .

Next, in FIG. 7, in the relationship between the pulse interval Δ and the capillary force (1 / d) and the ink ejection area, the area (Δ> Δ ^* ) is not incapable of ejection, but the pulse interval Is too long to print, is not practical, and the other area is (1 / d) <(1 / d ^* ), and ink cannot be held directly above the heater due to insufficient capillary force. No ejection was possible, and the area of Δ <k
₂ (1 / d), and the pulse interval is too short to supply ink in time, and ink is not ejected.

From this, the ink dischargeable area is k ₂ (1 / d) ≦ Δ
≦ Δ ^* and 1 / d ≧ 1 / d ^* .

As described above, generally speaking, the magnitude of the capillary force can be controlled by the distance d between the projections of the capillary structure. If the distance is large, the capillary force is small, and if the distance is small, the capillary force is small. The larger the capillary force is, the larger the capillary structure is, the more the ink is retained, and the faster the escaped ink returns, the higher the energy can be applied, and the pulse of high energy can be applied, and the pulse interval can be shortened. it can. Conversely, it has also been found that when the capillary force is small, it is necessary to use a relatively low-energy pulse or to increase the pulse interval.

Based on these findings, the following various tests were performed.

FIG. 8 shows the above-described printer head.
The ink was used for magenta, the pulse time was fixed at 15 μsec, and the pulse interval was fixed at 5 μsec.
This shows the result of examining the ink ejection state based on the relationship between d) and P (power: unit is mW).

According to this, 1 / d = 0.2 and P = 1
10 mW, 1 / d = 0.5 and P = 160 mW, 1 / d
= 1.0 and P = 210 mW, ink can be ejected, and 1 / d = 0.5, P = 140 mW, 1
When /d=1.0 and P = 170 mW, the ink was ejected well.

FIG. 9 shows the ink ejection state based on the relationship between the capillary force (1 / d) and Δ (pulse interval) with the ink used for magenta, the pulse time fixed at 15 μsec, and P (power) fixed at 160 mW. 1 shows the result of the examination.

According to this, 1 / d = 0.2 and Δ = 1
8 μsec, 1 / d = 0.5 and Δ = 10 μsec, 1
If /d=1.0 and Δ = 5 μsec, ejection becomes possible, and 1 / d = 0.5 and Δ = 15 μsec, 1 /
When d = 1.0 and Δ = 10 μsec, the ejection becomes good.

From the results of FIG. 8 and FIG. 9, it is impossible to discharge or improper discharge in the area outside the dischargeable line and the predetermined power or pulse interval. Therefore, it is desirable to set the conditions in the area inside these lines. . That is, this desirable range is: 110 ≦ P ≦ {125 (1 / d) +85}, and 0.2
≦ 1 / d or {−16.25 (1 / d) +21.25} ≦ Δ ≦ 20,
And 0.2 ≦ 1 / d.

The embodiments and examples of the present invention described above can be further modified based on the technical concept of the present invention.

For example, with respect to the above-described heater driving pulse, both the magnitude or width of the pulse voltage (or current) and the pulse interval may be changed, or only one of them may be changed. That is, the pulse time, the pulse interval, and P (power) may be controlled, but the width, height, and interval of the columnar body can also be variously changed.

Further, in addition to the heater, the ink may be heated by a laser or the like, and the structure of the transfer portion is not limited to the above-described one, and may be variously changed. Ink ejection can also be performed by using a mechanical mechanism together, or, besides applying a drive pulse for each dot, a drive pulse can be given in block units by block. Further, the printer head described above can be of a serial type in addition to the line type.

[0095]

As described above, the present invention relates to a recording apparatus for recording on a recording medium by flying a recording liquid held in a capillary structure, and a method of driving the recording apparatus. Since the flying energy of the recording liquid is controlled in accordance with the above, if the capillary structure has a large capillary force, a high energy can be applied because the retention of the recording liquid and the returning speed of the escaped recording liquid are large, vice versa,
With a capillary structure having a small capillary force, relatively low flying energy can be applied. As a result, stable discharge or vaporization can always be performed according to the capillary structure.

Further, since the recording is performed by the flying of the recording liquid, the transfer speed is increased, the density gradation within the pixel is facilitated, and a high quality image is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic enlarged cross-sectional view (a cross-sectional view taken along line II of FIG. 2) of a vicinity of a transfer portion of a printer head according to the present invention.

FIG. 2 is a schematic enlarged plan view of the vicinity of a transfer portion of the printer head.

FIG. 3 is a drive pulse diagram showing an example of a pulse time, a pulse interval, and a pulse voltage.

FIG. 4 is a perspective view of the same printer.

FIG. 5 is a perspective view of the printer head.

FIG. 6 is a correlation diagram between the power P and the capillary force 1 / d.

FIG. 7 is a correlation diagram between the pulse interval Δ and the capillary force 1 / d.

FIG. 8 is a specific correlation diagram between the power P and the capillary force 1 / d.

FIG. 9 is a specific correlation diagram between the pulse interval Δ and the capillary force 1 / d.

[Explanation of symbols]

1. Transfer part, 2. High resistance part (heater, resistance heating means),
3a, 3b: low resistance portion, 4: individual electrode, 5: common electrode,
6 ... columnar body, 7 ... partition wall, 8 ... auxiliary wall, 9 ... substrate, 10 ...
Heat insulating layer, 11: barrier metal layer, 12: protective film, 30 ...
Personal computer, 31 ... drive pulse generation circuit,
100Y, M, C: printer head, T ₁ : pulse width, T ₂ : pulse interval, T ₃ : pulse voltage, P: power, d: columnar interval, 1 / d: capillary force, Δ: pulse interval

Continued on front page F-term (reference) 2C057 AF39 AF71 AG21 AG40 AG42 AG46 AG91 AG99 AJ10 AL40 AM03 AM15 AM21 AM22 AN01 AN05 AP02 AP14 AP56 AQ02 AR04 AR08 BF06

Claims (28)

[Claims] In a recording apparatus for performing recording on a recording medium by causing a recording liquid held in a capillary structure to fly, a flying portion of the recording liquid is applied to a flying portion of the recording liquid in accordance with the magnitude of the capillary force of the capillary structure. A recording apparatus, wherein flying energy control means for controlling the flying energy of the recording liquid is connected. 2. The method according to claim 1, wherein the recording liquid is discharged or vaporized by the energy of a heater, and the magnitude or width of a pulse voltage or a pulse current for driving the heater is determined in accordance with the magnitude of the capillary force. The recording device according to claim 1, wherein at least one of the interval is adjusted. 3. The recording apparatus according to claim 2, wherein the pulse voltage or the pulse current is increased or the pulse interval is reduced as the capillary force increases. 4. The power of the heater is represented by P (unit: m
W), the pulse interval is Δ (unit: μsec), and the interval in the gap of the capillary portion of the capillary structure is d ｛, where unit (μ)
m). When {(1 / d is the capillary force)}, 110 ≦ P ≦ {125 (1 / d) +85} and 0.2
≦ 1 / d or {−16.25 (1 / d) +21.25} ≦ Δ ≦ 20,
3. The recording apparatus according to claim 2, wherein 0.2 and 1 / d. 5. The recording apparatus according to claim 2, wherein heating of the heater is controlled by a drive pulse set by a computer. 6. A liquid produced by forming a porous structure by columnar bodies each having a size and an interval of 0.1 to 10 μm as the capillary structure, and forming the recording liquid into droplets according to recording information. The drop is 10-500μ with the flying part
The recording apparatus according to claim 1, wherein the recording apparatus flies to the recording medium that is opposed to the recording medium with a gap of m. 7. The capillary structure has a height of 1 to 20 μm.
m, diameter or side is 0.1-5 μm, interval is 0.1-5
The protrusions having a heat resistance of not less than 300 ° C. are 2 to 100 rows and 2 to 100 rows in the vertical and horizontal directions, respectively.
The recording apparatus according to claim 1, wherein a porous structure having a pattern arranged in a matrix in a range of a row is formed. 8. The recording apparatus according to claim 1, wherein the recording liquid consumed in the flying unit is continuously supplied to the flying unit. 9. The recording apparatus according to claim 1, wherein, in the ejection of the recording liquid, the momentum of the discharged droplet is generated by the convection momentum of the recording liquid generated by heating by the heater. 10. The convection of the recording liquid is caused by uneven surface tension of the liquid surface of the recording liquid due to heating.
The recording device described in 1. 11. The recording apparatus according to claim 9, wherein the convection of the recording liquid is caused by volume expansion of the recording liquid due to boiling of the components of the recording liquid. 12. The recording apparatus according to claim 9, wherein the convection of the recording liquid is caused by expansion of the dissolved air in the recording liquid due to heating, or expansion and rupture. 13. The recording apparatus according to claim 9, wherein the convection of the recording liquid is caused by thermal expansion of the recording liquid. 14. The recording apparatus according to claim 9, wherein the convection of the recording liquid is caused by thermal expansion of the heater or the capillary structure. 15. A method of driving a recording apparatus for performing recording on a recording medium by causing a recording liquid held in a capillary structure to fly, wherein the recording liquid flies in accordance with the magnitude of the capillary force of the capillary structure. A method for driving a recording device, comprising controlling energy. 16. The recording liquid is discharged or vaporized by energy of a heater, and a magnitude or width of a pulse voltage or a pulse current for driving the heater according to the magnitude of the capillary force; The method according to claim 15, wherein at least one of the following is adjusted. 17. The method according to claim 16, wherein the pulse voltage or the pulse current is increased or the pulse interval is reduced as the capillary force increases. 18. The power of the heater is represented by P (unit: m
W), the pulse interval is Δ (unit: μsec), and the interval in the gap of the capillary portion of the capillary structure is d ｛, where unit (μ)
m). When {(1 / d is the capillary force)}, 110 ≦ P ≦ {125 (1 / d) +85} and 0.2
≦ 1 / d or {−16.25 (1 / d) +21.25} ≦ Δ ≦ 20,
The method according to claim 16, wherein 0.2 and 1 / d. 19. The method according to claim 16, wherein heating of the heater is controlled by a drive pulse set by a computer. 20. As the capillary structure, a porous structure is formed by columnar bodies each having a size and an interval of 0.1 to 10 μm, and the recording liquid is formed into droplets according to recording information, and the generated liquid is formed. Drop the droplets with the flying part by 10 to 500 μm.
16. The driving method of a recording apparatus according to claim 15, wherein the recording apparatus is caused to fly to the recording medium which is disposed to face the recording medium with a gap of m. 21. The capillary structure has a height of 1 to 20.
μm, diameter or side is 0.1-5 μm, interval is 0.1-
The protrusions having a heat resistance of 5 μm and 300 ° C. or more are formed in 2 to 100 rows and 2 to 10 rows in the vertical and horizontal directions, respectively.
The method according to claim 15, wherein the porous structure having a pattern arranged in a matrix in a range of 0 columns is formed. 22. The driving method of a recording apparatus according to claim 15, wherein the recording liquid consumed in the flying unit is continuously supplied to the flying unit. 23. The method of driving a recording apparatus according to claim 15, wherein, in discharging the recording liquid, the momentum of the discharged droplet is generated by the convection momentum of the recording liquid generated by heating by the heater. 24. The method of driving a recording apparatus according to claim 23, wherein the convection of the recording liquid is caused by uneven surface tension of the liquid surface of the recording liquid due to heating. 25. The method for driving a recording apparatus according to claim 23, wherein the convection of the recording liquid is caused by volume expansion of the recording liquid due to boiling of the components of the recording liquid. 26. The driving method of a recording apparatus according to claim 23, wherein the convection of the recording liquid is caused by expansion of the dissolved air in the recording liquid due to heating, or expansion and rupture. 27. The method according to claim 23, wherein the convection of the recording liquid is generated by thermal expansion of the recording liquid. 28. The recording liquid according to claim 2, wherein the convection of the recording liquid is generated by thermal expansion of the heater or the capillary structure.
3. The method for driving a recording device according to item 3.