JPH0671907A - Ink-jet recording apparatus - Google Patents

Abstract

(57) [Abstract] [Purpose] Prevents clogging of the ejection port 59 of the head 1, prevents density unevenness of a recorded image on the recording paper 21, and realizes high-speed high-gradation recording with excellent gradation reproducibility. To be able to do in. [Structure] Solid ink in an ink tank 3 is heated and melted and supplied to a head 1, and ink droplets ejected simultaneously from all of a plurality of ejection ports 59 of the head 1 land on the surface of an intermediate drum 6 to form ink. A layer is formed, and only a pixel of ink on the intermediate drum 6 is melted by a laser beam in accordance with an image signal using light amount modulation together, and the melted pixel ink is transferred to the recording paper 21 on the transfer drum 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for recording with ink discharged from a head.

[0002]

2. Description of the Related Art A recording device having functions such as a printer, a copying machine and a facsimile, or a recording device used as an output device of a multifunction machine or a workstation including a computer, a word processor, etc., is a sheet or a plastic thin plate based on image information. An image (including characters and symbols) is recorded on a recording material (recording medium) such as (OHP). The recording apparatus can be classified into an ink jet type, a wire dot type, a heat sensitive type, a thermal transfer type, a laser beam type, etc., depending on the type of recording means (recording head) used.

Further, the recording apparatus uses a serial scan type recording apparatus or a line type recording means for recording by a recording means which moves in the paper width direction on a recording material which is intermittently fed by a recording scanning method. Line-type recording apparatus that performs recording only by scanning the recording material in the paper feed direction, a drum-scan recording apparatus that performs recording by recording means that moves along the drum axis with respect to the recording material that rotates with the drum, or other It can be divided into recording devices using a scanning method.

Among the above recording apparatuses, an inkjet recording apparatus using an inkjet head, that is, an inkjet recording apparatus for recording with ink droplets ejected from a plurality of ejection openings (usually a plurality of ink jet heads), can easily be made compact in size. High-definition images can be recorded at high speed, plain paper can be recorded without requiring special processing, running costs are low, and the non-impact method produces less noise and multi-color images. It has advantages such as easy recording of a color image using ink. Among them, the line type using a full multi type head in which a large number of ejection ports are arranged can further speed up recording.

In particular, an ink jet head for ejecting ink by utilizing heat energy is subjected to a semiconductor manufacturing process such as etching, vapor deposition and sputtering, and an electrothermal converter formed on a substrate, an electrode, a liquid passage wall, By forming a top plate, etc., it is possible to easily manufacture a product having a high-density liquid path arrangement (ejection opening arrangement), and it is possible to record a high-resolution image at high speed with a simple and compact structure. it can. On the other hand, there are various requirements for the material of the recording material, and in recent years, in addition to ordinary recording material such as plain paper and resin thin plate (OHP, etc.), thin paper and processed paper (punching holes for filing). It has become necessary to use attached paper, perforated paper, paper of any shape, etc.).

In the ink jet recording apparatus, a method of performing a pseudo intermediate process such as a dither method or an error diffusion method has been conventionally performed when a high gradation is performed to improve image quality. However, generally, in these processes, the resolution decreases as the number of gradations increases, and it is difficult to increase both of them. Therefore, in order to eliminate such an inconvenience, a method has been proposed in which the size of one dot itself is changed by overlapping ejection of ink to obtain high gradation without lowering the resolution.

A continuous method and an on-demand method are conceivable as embodiments of the dot diameter changing method by overlapping printing. The continuous method is a mode in which ink droplets that are continuously ejected are charged, and ink droplets are selected by a deflection electrode according to an image signal. On the other hand, the on-demand method selectively changes ink droplets from the ejection port by utilizing the pressure variation due to the electromechanical conversion element or the pressure variation due to generation of bubbles due to energization of the heater inside the ejection port, depending on the presence or absence of an image signal. It is a form to be discharged to.

[0008]

However, the conventional continuous method and on-demand method have the following disadvantages when attempting to perform overprinting. First, in the continuous method, it is difficult to make multiple ejection ports, and there is a limit to increase the recording speed. In particular, if an attempt is made to realize n gradations by overprinting, the recording speed will be 1 / n times that of binary recording, and the recording speed will decrease. The reason is that, since it is necessary to perform charge deflection for each ejection port, the deflection electric field of a certain ejection port affects ink droplets from the adjacent ejection port as the ejection port becomes multi-layered. This is because accurate ink droplet selection becomes impossible or difficult.

Next, the on-demand system has the following two disadvantages. First, although multiple ejection ports are possible, at present, there is a limit to the dimensional accuracy when manufacturing the ejection ports, so that the ejection amount of ink droplets varies from ejection port to ejection port. This variation appears as density unevenness in the image, and the image quality deteriorates. In particular, when aiming for high image quality by repeated printing, gradation reproducibility is impaired due to variations in the ink ejection amount, which causes image quality deterioration. Secondly, since it is a method of ejecting ink in accordance with an image signal, depending on the image, there are ejection ports that do not eject continuously for a certain period, and volatile components (water content) in the ink in the ejection ports that do not eject are generated. And the like) evaporate with time, and eventually the ejection port is clogged, resulting in ejection failure (including non-ejection).

Therefore, conventionally, as a method for preventing the above-described clogging of the ejection openings, a process (idling) of ejecting ink from all the ejection openings is performed at regular intervals regardless of the image. By the way, the time until clogging is shorter as the discharge port inner volume is smaller. However, when high gradation is realized by overprinting, it is usual to set the diameter of the ejection port smaller than the diameter of the ejection port for binary recording in order to express a low density portion. Therefore, in the dot diameter varying method by overlapping ejection, it is necessary to shorten the interval of blank ejection. However, since blank driving is performed in the space provided for blank driving, there is a limit to shortening the blank driving interval. As described above, there is a limit to reducing the diameter of the ejection port, and thus there is a limit to increasing the gradation by the on-demand method.

The present invention has been made in view of the above technical problems, and an object of the present invention is to prevent clogging of an ejection opening and unevenness of image density and to perform high gradation recording at high speed. Another object of the present invention is to provide an inkjet recording device.

[0012]

SUMMARY OF THE INVENTION An ink jet recording apparatus of the present invention comprises a head for ejecting ink from an ejection port, an ink supplying means for melting and supplying solid ink that melts at a temperature higher than room temperature to the head, and ejecting from the head. By including an intermediate medium on which the formed ink droplets land, a remelting unit that selectively heats and melts the ink on the intermediate medium, and a transfer unit that transfers the molten ink on the intermediate medium to a recording material. It achieves the above object.

According to another aspect of the present invention, in addition to the above configuration, a configuration in which a plurality of ejection ports is provided in the head, a configuration in which a means for heating ink by light irradiation is used as the remelting means, or a light in the remelting means is used The present invention provides an inkjet recording apparatus capable of high-gradation recording with further excellent gradation reproducibility by using a means capable of modulating the light amount during irradiation.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic side view showing a schematic configuration of an embodiment of an inkjet recording apparatus to which the present invention is applied. Figure 1
Shows the case of an inkjet recording apparatus for color recording. In FIG. 1, 1C, 1M, 1Y, and 1B represent inkjet heads, respectively, and these four heads are
The ink droplets of cyan (C), magenta (M), yellow (Y), and black (B) are ejected. In the following description, these heads 1
All or any one of C, 1M, 1Y, and 1B is simply indicated by the head 1.

Each of the ink jet heads 1 is, for example, a multi-head having a density of 16 / mm and a discharge width of about 4,800 across the width of A3 size. In this case, the diameter of each discharge port is within 30 microns. Four
The individual heads 1 are held by the head block 2 at positions at equal intervals in the circumferential direction of a part of the outer peripheral surface of the intermediate drum 6 so as to face the outer peripheral surface with a predetermined gap. Each head 1 is an inkjet head that ejects ink by using thermal energy, and includes an electrothermal converter for generating thermal energy. Further, the head 1 ejects ink from the ejection port by utilizing the pressure change caused by the growth and contraction of bubbles due to film boiling caused by the thermal energy applied by the electrothermal converter.

FIG. 2 is a partial perspective view schematically showing the structure of the ink ejection portion of the head 1. In FIG. 2, a plurality of electrothermal converters 52 and wirings corresponding thereto are formed on the substrate 51 of the head 1 with the layer of the thin film 53 interposed, by the same manufacturing process (thin film molding method, etc.) as for semiconductors. Has been formed. As shown in the drawing, each electrothermal converter 52 is arranged at a position corresponding to each discharge port 59 and liquid path 56. On the substrate 51 (the thin film 53 on the substrate 51
A liquid path forming member 54 having a plurality of liquid path walls 54 </ b> A formed in parallel on the lower surface is joined to the upper side. Further, the top plate 5 is provided on the upper surface of the liquid path forming member 54.
5 are joined. The liquid passage 5 is provided between the respective liquid passage walls 54A.
6 is formed, the liquid passage forming member 54 is
The electrothermal converters 52 are positioned and joined so that the electrothermal converters 52 are arranged at predetermined positions inside.

Each of the liquid passage walls 54A has a predetermined length,
The rear end of each liquid passage 56 has a common liquid chamber 5 formed between the liquid passage forming member 54 and the substrate 51 (or the thin film 53).
It communicates with 7. On the other hand, the other end (tip) of each liquid path 56 is opened at the ejection port surface (face surface) 58 of the head 1, and the ejection port 59 is formed by each opening. In this manner, the electrothermal converter 52 such as a heating resistor is energized (pulse voltage is applied) to generate heat, thereby causing the ink in the liquid path 56 to boil, and the pressure change at that time causes ink to be ejected from the ejection port 59. An inkjet head 1 that ejects droplets is configured. In addition, the head 1
Is attached in such a manner that the arrangement direction of the plurality of ejection ports 59 intersects the conveying direction of the recording material (recording paper or the like). The clearance between the discharge port surface 58 and the surface of the intermediate drum 5 is set to about 0.5 mm, for example.

In FIG. 1, an ink tank 3 is attached to each head 1. 3 is a schematic plan view of the head 1 taken along line 3-3 in FIG. 1, and FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. As shown in FIG. 4, the solid (solid) ink 24 is inserted into the ink tank 3 of each head 1, and the inside of the ink tank 3 and the common liquid chamber 57 of the head have two communication ports on both sides. It communicates via 26. A heat conductor 4 having a length substantially the same as the length of the head 1 in the longitudinal direction is joined to the other surface of the head 1. As the heat conductor 4, for example, a heat pipe having a high heat conductivity is used. A heater 5 is joined to the surface of the heat conductor 4.

By energizing the heater 5, the head 1 is evenly heated via the heat conductor 4, and the solid ink 24 in the ink tank 3 is melted by the heat. The melted ink is supplied to the common liquid chamber 57 through the communication port 26. Further, the liquid ink supplied from the common liquid chamber 57 into each liquid passage 56 is ejected from the corresponding ejection port 59 by driving (energizing) a predetermined electrothermal converter 52 according to an image signal. It Head 1
The ink droplets ejected from the intermediate drum 6 (FIG. 1)
Land on the surface (outer peripheral surface) of.

In FIG. 1, an intermediate medium (intermediate drum) 6
The ink on the surface of the ink is selectively heated and melted by the remelting means in accordance with the image signal. In this embodiment, this remelting means is composed of a laser scanning unit 7, an fθ lens 8 and a mirror 9. The laser scanning unit 7 can scan over a width of A3 size while turning on / off a laser beam of 50 to 100 mW, for example. The fθ lens 8 is for keeping the scanning speed constant. The mirror 9 is for returning the beam from the laser scanning unit 7 and irradiating the surface of the intermediate drum 6.

A transfer drum (transfer means) 10 axially supported in parallel with the intermediate drum 6 is pressed against the intermediate drum (intermediate medium) 6. This transfer drum 10
Is for transferring the molten ink on the intermediate drum 6 to the recording material 21, and also serves as a conveyance roller for the recording material 21. In this embodiment, the earth roller 22 is pressed against the peripheral surface of the transfer drum 10, and a positive charge is injected onto the surface of the transfer drum 10 by a corona charger for electrostatic attraction (not shown). The recording material 21 is attracted and conveyed by the Coulomb force between the recording material 21 and the recording material 21 that is grounded by 22.
Therefore, when the intermediate drum 6 and the transfer drum 10 are rotationally driven in the direction of the arrow, the intermediate drum 6 with respect to the recording material 21 sucked and conveyed by the transfer drum 10.
The molten ink (image pattern) above can be transferred and recorded. The circumference of the transfer drum 10 is, for example, A
It is set to 430 mm, which is about 10 mm longer than the 420 mm of the three sizes in the longitudinal direction.

At a position adjacent to the intermediate drum 6, a cleaning blade 11 for removing the ink solidified on the surface of the intermediate drum 6 is arranged. The ink removed from the surface of the intermediate drum 6 is collected in the waste ink tank 12. Further, a separation claw 13 for peeling off the recording material 21 adsorbed on the transfer drum 10 is provided at a position adjacent to the transfer drum 10. This separation claw 13
Touches the transfer drum 10 only when the recording material 21 is discharged. Recording material 2 peeled from the surface of transfer drum 10
1 passes through the paper ejection guide 14 and is ejected onto the paper ejection tray 16 by the paper ejection roller 15.

On the other hand, the paper feed mechanism for supplying the recording material 21 to the surface of the transfer drum 10 is composed of a paper feed tray 17,
Pickup roller 18, paper feed roller 19, paper guide 2
0, the registration roller 23, the earth roller 22 and the like. In the paper feed tray 17, recording materials 21 of A3 size, for example, are stacked and stacked. The pickup roller 18 separates (picks up) the recording materials 21 in the paper feed tray 17 one by one. The paper feed roller 19 feeds the separated recording material 21. And
The recording material 21 fed is conveyed in a state in which the registration roller 23 corrects the posture thereof at right angles to the axial direction of the transfer drum 10, and at the position of the earth roller 22, the peripheral surface of the transfer roller 10 is conveyed. Wrap it exactly around.

FIG. 7 is a flow chart showing the sequence of the recording operation of the ink jet recording apparatus described with reference to FIGS. Next, the operation of the above inkjet recording apparatus will be described with reference to FIG. When the power of the recording apparatus is turned on, the heaters 5 of the heads 1 are simultaneously turned on (steps S1 and S2). When the temperature detected by a temperature sensor (not shown) attached to one of the heads (for example, black head) 1 reaches a predetermined temperature (for example, 90 ° C.) (step S3), a recordable state is set. At this time, the other heads 1 are also heated to a predetermined temperature and are in a recordable state.

Next, when a recording signal is input (step S
4) The intermediate drum 6 and the transfer drum 10 are rotationally driven at a predetermined peripheral speed (for example, 625 mm / sec) (step S5). Then, one recording material 21 is picked up by the pickup roller 18 and guided to the stopped registration roller 23 by the paper feed roller 19 (step S6). When the tip of the recording material 21 abuts on the abutting portion of the two abutting registration rollers 23, the recording material 2 is formed between the registration roller 23 and the paper feed roller 19.
1 is formed, and the transfer drum 10 of the recording material 21 is formed.
The directionality for is accurately maintained. Next, the registration roller 23 is rotationally driven to feed (paper feed) the recording material 21 (step S7), and the pickup roller 18 is stopped (step S8).

Recording material 21 exiting registration roller 23
Is fed along the paper guide 20 and guided to the contact portion between the transfer drum 10 and the ground roller 22. The recording material 21 is the transfer drum 1 that has been previously positively charged.
While being pinched between 0 and the earth roller 22, it is electrostatically adsorbed on the surface of the transfer drum 10 (step S9).
The intermediate drum 6 and the transfer drum 10 continue to rotate at a constant speed.

On the other hand, on the surface of the intermediate drum 6, droplets of molten ink are ejected from all ejection ports 59 (for example, 4800 ejection ports) of the cyan head 1 (step S).
10). Ejection frequency at this time is, for example 10KH _Z, the intermediate drum 6 is rotating, for example, 625 mm / sec, ink droplets will be landed at a pitch of 16 dots / mm. As the ink, for example, a mixture of 2,6-dimethylquinoline, paraffin wax (HNP9, manufactured by Nippon Seiro Co., Ltd.) and a dye at a weight ratio of 67: 30: 3 is used. This ink has a supercooling property, and does not solidify immediately after landing, but solidifies after a certain period of time. Therefore, in the ink on the intermediate drum 6, adjacent ink dots are connected to each other to form a substantially uniform layer having a thickness of about 8 μm. FIG. 5 is a schematic partial plan view illustrating a state in which adjacent ink dots are continuous, and FIG. 6 schematically shows a state of a layer having a substantially uniform thickness along a line 6-6 in FIG. It is sectional drawing shown.

Registration roller 23 and paper feed roller 19
Is stopped (step S11). Next, the solidified ink on the rotating intermediate drum 6 is irradiated with a laser spot from the laser scanning unit 7 through the fθ lens 8 and the mirror 9 according to an image signal (step S12). The diameter of the laser spot is set to about 30 μm, for example. At this time, by changing the driving pulse width of the laser beam according to the input multi-valued image data for each pixel, it is possible to change the size of the pixel to be melted by the energy of the laser beam. That is, multivalued image recording is possible by modulating the amount of light with which each pixel is irradiated.

Among the laser-scanned ink, only the pixels melted by laser irradiation are transferred to the recording material 21 on the transfer drum 10 at the pressure contact portion between the intermediate drum 6 and the transfer drum 10 (step S13). Recording of the ink (cyan ink) is performed. Other ink (non-pixel portion) is scraped off the transfer drum 10 by the cleaning blade 11, and the waste ink tank 12
It is collected inside (step S14).

Thereafter, magenta (M), yellow (Y),
The same sequence as described above is repeated for the black (B) ink, and multi-valued color recording is performed on the recording material 21 (steps S16, S17, S13-).
S15). After the recording, the recording material 21 is separated by the separating claw 13.
Is removed by bringing it into contact with the transfer drum 10 (step S18), passes through the paper ejection guide 14, and passes through the paper ejection roller 1
5, the sheet is discharged onto the discharge tray 16 (step S1).
9-S21).

Recording of one recording material 21 is completed as described above, but when continuous recording is performed (step S22),
The pickup roller 18 is turned on again (step S
6), the same sequence as described above is repeated. Furthermore, by repeating the same sequence in sequence, it is possible to perform recording on a plurality of recording materials 21 one after another. When the recording is completed, the intermediate drum 6 and the transfer drum 10 are stopped (step S23), the recording operation is completed, and the power of the recording apparatus is turned off (step S2).
4).

According to the embodiment described above, the head 1 having at least two or more ejection ports 59 and capable of ejecting ink droplets from all the ejection ports simultaneously, and the solid ink 24 that melts at a constant temperature higher than room temperature. Ink supply means 3, 4, 5, 26 for melting and supplying the ink to the head 1, and an intermediate drum (intermediate medium) on which ink droplets ejected from the head 1 land
6, and remelting scanning means 7 for selectively irradiating the ink on the intermediate drum 6 with light to melt the pixel portion,
Since the ink jet recording apparatus has the constitution in which the recording drums 8 and 9 and the transfer drum (transfer means) 10 for transferring the melted ink to the recording material 21 are used, the recording speed is high and the recording can be performed without image density unevenness. A recording device was obtained. Further, since the irradiation light quantity by the remelting scanning means 7, 8 and 9 can be modulated, an ink jet recording apparatus capable of high gradation recording excellent in gradation reproducibility can be obtained.

In the illustrated embodiment, the case of a color ink jet recording apparatus has been described, but the same can be applied to a single color ink jet recording apparatus, and in that case, recording can be performed at high speed without density unevenness. be able to.
In this case, a belt may be used instead of the transfer drum 10, and the recording material 21 may be sucked and conveyed on the belt.

As means for selectively irradiating the ink on the intermediate drum 6 with light, a liquid crystal shutter array, an LED array, or the like may be used instead of the laser scanning unit 7 described above. The same action and effect can be obtained by such a configuration.

In the above-mentioned embodiment, the case where the line type head 1 covering the width direction of the recording material 21 is used has been described, but the present invention is not limited to this, and for example, 256 ejections are performed. A 16 mm wide head having an outlet is serially scanned and an intermediate drum 6 is intermittently fed to form an ink layer on the entire surface of the drum, and thereafter, the intermediate drum is rotated at a constant speed to perform laser scanning. Good.

In the above embodiment, the color ink jet recording apparatus having a plurality of heads respectively using different color inks has been described as an example, but the present invention has one head. It can be similarly applied to any number and types of heads, such as an ink jet recording apparatus or an ink jet recording apparatus for gradation recording including a plurality of heads using inks of the same color and different densities, The same effect can be obtained. Also,
The present invention is applicable to any type of arrangement of the head and the ink tank, such as a cartridge type in which the head and the ink tank are integrated, or a head and the ink tank are separately provided and connected by an ink supply tube or the like. Even if it exists, it can be similarly applied and the same effect can be achieved.

The present invention can be applied to any ink jet recording apparatus that uses a head using an electromechanical transducer such as a piezo element.
This brings an excellent effect in an ink jet recording apparatus of a type that ejects ink by utilizing thermal energy. This is because such a system can achieve high density recording and high definition recording.

Regarding the typical structure and principle thereof, see, for example, US Pat. Nos. 4,723,129 and 4740.
This is preferably done using the basic principles disclosed in 796. This method can be applied to both the so-called on-demand type and the continuous type, but particularly in the case of the on-demand type, a liquid (ink) is used.
By applying at least one drive signal to the electrothermal converter arranged corresponding to the sheet or liquid path in which is stored, which corresponds to the recorded information and causes a rapid temperature rise exceeding nucleate boiling. This is effective because heat energy is generated in the electrothermal converter to cause film boiling on the heat acting surface of the head, and as a result, bubbles can be formed in the liquid (ink) in a one-to-one correspondence with this drive signal.

Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection openings to form at least one droplet. It is more preferable to make the driving signal into a pulse shape because bubbles can be grown and contracted immediately and appropriately, and thus a liquid (ink) with excellent responsiveness can be ejected. As this pulse-shaped drive signal, US Pat.
Those described in US Pat. Nos. 4,633,359 and 4,345,262 are suitable. Incidentally, US Pat. No. 43131 of the invention relating to the rate of temperature rise of the heat acting surface.
If the conditions described in the specification of No. 24 are adopted, more excellent recording can be performed.

As the constitution of the head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angle liquid passage) as disclosed in the above-mentioned respective specifications, the heat U.S. Pat. No. 4,558,333, U.S. Pat. No. 445, which discloses a configuration in which the action portion is arranged in a bending region.
A configuration using the specification of No. 9600 is also included in the present invention. In addition, Japanese Laid-Open Patent Publication No. 123670/1984 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy. The present invention is also effective as a structure based on Japanese Patent Laid-Open No. 138461/1984, which discloses a structure in which the above is associated with the discharge portion. That is, according to the present invention, recording can be surely and efficiently performed regardless of the shape of the head.

Further, as described above, the present invention can be effectively applied to a full line type recording head having a length corresponding to the maximum width of a recording material (recording medium) which can be recorded by the recording apparatus. . As such a head, a configuration that satisfies the length by a combination of a plurality of heads,
It may be configured as one head formed integrally. In addition, even with the serial type as in the above example, it is possible to electrically connect to the device body or supply ink from the device body by mounting it on the head fixed to the device body or on the device body. The present invention is also effective when a replaceable chip type head or a cartridge type head in which an ink tank is integrally provided in the head itself is used.

Further, it is preferable to add recovery means or preliminary auxiliary means to the head provided as a constitution of the recording apparatus in the present invention because the effect of the present invention can be further stabilized. If you list these specifically,
Capping means, cleaning means, pressurizing or suctioning means, electrothermal converter or other heating element or preheating means by a combination thereof for the head,
It is also effective to perform stable recording by performing a preliminary discharge mode in which discharge is performed separately from recording.

As described above, regarding the type and number of heads mounted, for example, only one head is provided corresponding to a single color ink, or a plurality of heads having different recording colors and densities are provided. A plurality of inks may be provided corresponding to the ink. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but the head may be integrally configured or a plurality of combinations may be used. The present invention is extremely effective for an apparatus provided with at least one of color or full color by color mixture.

In addition, during recording, the temperature of the ejected ink itself is generally adjusted within the range of 30 ° C. to 70 ° C. to control the temperature of the ink so that the viscosity of the ink is within the stable ejection range. Therefore, it suffices that the ink be in a liquid state when the use recording signal is applied. That is, the temperature rise by thermal energy may be positively used as the energy for changing the state of the ink from the solid state to the liquid state, or by using the ink that solidifies in the standing state for the purpose of preventing the evaporation of the ink. In any case, an ink having a property of liquefying at the time of ejection due to application of heat energy or the like may be used.

The ink in such a case is disclosed in JP-A-54-54.
As described in JP-A-56847 or JP-A-60-71260, a form in which the electrothermal converter is opposed to a liquid sheet or a solid material held in the recesses or through holes of the porous sheet. May be In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as a form of the ink jet recording apparatus according to the present invention, in addition to one used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function. And the like may be used.

[0047]

As is clear from the above description, according to the ink jet recording apparatus of the present invention, the ink is ejected from the ejection port and the ink which is melted at the temperature higher than room temperature and is supplied to the head. Supply means,
A structure having an intermediate medium on which ink droplets ejected from the head land, remelting means for selectively heating and melting the ink on the intermediate medium, and transfer means for transferring the melted ink on the intermediate medium to a recording material Therefore, it is possible to provide an inkjet recording device capable of preventing clogging of the ejection port and unevenness of image density and performing high-gradation recording at high speed.

According to another aspect of the present invention, in addition to the above configuration,
Since the head is provided with a plurality of ejection ports, the re-melting means uses a means for heating ink by light irradiation, or the re-melting means uses a means capable of modulating the light amount at the time of light irradiation. In addition to the above effects, there is provided an ink jet recording apparatus capable of high gradation recording with further excellent gradation reproducibility.

[Brief description of drawings]

FIG. 1 is a schematic side view showing a schematic configuration of an embodiment of an inkjet recording apparatus to which the present invention is applied.

FIG. 2 is a partially cutaway perspective view schematically showing the structure of an ink ejection portion of the head shown in FIG.

FIG. 3 is a schematic plan view of the head taken along line 3-3 in FIG.

4 is a schematic cross-sectional view of the head taken along the line 4-4 in FIG.

FIG. 5 is a partial plan view schematically showing a solidified ink layer on an intermediate medium.

6 is a partial cross-sectional view of the solidified ink layer taken along line 6-6 in FIG.

7 is a flowchart illustrating a sequence of a recording operation of the inkjet recording apparatus of FIG.

[Explanation of symbols]

 1 Head (Inkjet Head) 2 Head Block 3 Ink Tank 4 Heat Conductor 5 Heater 6 Intermediate Drum 7 Laser Scanning Unit 8 fθ Lens 9 Mirror 10 Transfer Drum 11 Cleaning Blade 12 Discharge Ink Tank 13 Separation Claw 15 Discharge Roller 16 Discharge Tray 17 Paper feed tray 18 Pickup roller 19 Paper feed roller 22 Earth roller 23 Registration roller 24 Ink (solid ink) 26 Communication port 52 Electrothermal converter 56 Liquid path 57 Common liquid chamber 58 Discharge port surface 59 Discharge port

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Claims (6)

[Claims] 1. A head for ejecting ink from an ejection port, an ink supply unit for melting and supplying solid ink that melts at a temperature higher than room temperature to the head, and an intermediate medium on which ink droplets ejected from the head land. An ink jet recording apparatus comprising: a re-melting unit that selectively heats and melts ink on a medium, and a transfer unit that transfers the melted ink on an intermediate medium to a recording material. 2. The ink jet recording apparatus according to claim 1, wherein the head has a plurality of ejection ports. 3. The ink jet recording apparatus according to claim 1, wherein the remelting unit heats the ink by light irradiation. 4. The ink jet recording apparatus according to claim 3, wherein the remelting unit is capable of modulating a light amount at the time of light irradiation. 5. The ink jet recording apparatus according to claim 1, wherein the head is an ink jet head having an electrothermal converter that generates thermal energy used for ejecting ink. 6. The ink jet recording apparatus according to claim 5, wherein the head ejects the ink from the ejection port by utilizing the film boiling generated in the ink by the thermal energy generated by the electrothermal converter.