JP2000198223A - Ink-jet recording apparatus, ejection recovery method and production of ink-jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain further stably the ejection characteristics represented by the ejection speed and the ejection amount of an ink in the recording operation of an image by ejecting the ink according to drive of the plurality of the electro-thermal converters by effectively executing the ejection recovery process and the aging process of an ink-jet recording head comprising a plurality of electro-thermal converters with respect to an ink channel. SOLUTION: An ink-jet recording head 1 comprising a plurality of heaters SH1, SH2 with respect to an ink channel 12 changes the shift amount of application timings of driving pulses to be applied on the heaters SH1, SH2 in the ejection recovery process after being mounted on a recording apparatus and/or the aging process step in the production of the ink-jet recording head 1.

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, a method for recovering the ink-jet recording apparatus, and a method for manufacturing an ink-jet recording head.

The present invention is directed to an ink jet recording head, an ink jet recording head cartridge, and an ink jet recording apparatus used in a copier, a facsimile, a word processor, a printer as an output terminal of a host computer, a video printer, and the like. The present invention is particularly directed to an inkjet printhead having a base on which an electrothermal converter that generates thermal energy used as energy for ejecting ink is formed, and a printing apparatus using the same. Here, the record is
It includes ink application (printing) to all ink supports to which ink is applied, such as cloth, thread, paper, and sheet material, and includes not only meaningful images such as characters but also pattern images. The recording device includes all of the various information processing devices or a printer as an output device thereof, and the present invention can be used for these devices.

[0003]

2. Description of the Related Art In a liquid jet recording method, a flying liquid droplet is formed by a recording liquid such as ink and the recording liquid is adhered to a recording material such as paper for recording. The liquid jet recording apparatus employing such a recording method can perform high-speed printing and high-density recording with low noise, and does not require processing such as development and fixing on plain paper. Is possible. Further, such a liquid jet recording apparatus has been particularly attracting attention as being capable of improving productivity in mass production and reducing manufacturing costs.

[0004] In order to form the flying droplets, a liquid jet recording head utilizing thermal energy has an electrothermal converter as a means for heating the recording liquid. That is, the recording head includes a heating resistor (hereinafter, also referred to as a “heater”) capable of heating the recording liquid by applying an electric signal and applying an electric signal to the heating resistor. And a pair of electrodes for performing the operation. The recording liquid foams by the heat generated by the heater, and is discharged from the ink discharge ports by the foaming energy. The recording liquid used here is generally a recording component such as a pigment or a dye, and water for dissolving or dispersing the same,
Alternatively, it is formed by a solvent component composed of water and a water-soluble organic solvent.

[0005] In such an aqueous recording liquid, the heating limit temperature for rapid vaporization is 250 ° C.
To 350 ° C. The heating limit temperature is the temperature at which steam is generated by the amount of heat transferred to the liquid via the extremely thin and stable vapor film between the surface of the heater and the liquid. Therefore, using a recording liquid having such a temperature characteristic,
Then, in order to form a flying droplet and record on a recording material by giving an electric signal to the heater to cause the recording liquid to foam, the heater is provided every time an electric signal is given.
Heating is repeated at a temperature from the ambient temperature to 300 ° C. to 800 ° C.

The heater and the electrodes are formed by a semiconductor process. For example, a heating resistor (for example, HfB ₂ , ZrB ₂ , or the like) provided on a substrate (for example, Si, glass, ceramic, or the like) is provided. TaN ₂ , T
an intermediate layer (for example, Ti,
A wiring portion (electrode, for example, Al, Au, Ag, Cu, or the like) made of a metal that is a good electrical conductor is formed via Cr or the like. The wiring portion is formed by laminating the intermediate layer so as to be exposed, and the exposed portion serves as a heater.
Further, on the heater and the electrode, if necessary, a protective film or the like having excellent heat resistance for preventing electrolytic corrosion and oxidation from the recording liquid and excellent recording liquid blocking property is formed.

In the above-described recording head, the discharge of the recording liquid is performed by applying an electric signal corresponding to the recording signal to the heater and repeatedly heating the heater to a high temperature to heat the recording liquid. Do. As described above, in a recording head having such a configuration and a recording apparatus equipped with such a recording head, it is necessary to improve recording characteristics during recording (particularly, characteristics of a recording liquid such as viscosity, surface tension, and density). There is proposed a process for the purpose.

Conventionally, such processing is performed, for example, in USP with a liquid jet recording head mounted on a recording apparatus.
US Pat. No. 4,463,359 or U.S. Pat. No. 4,463,359.
SP-4296421, USP-4719472,
And a pre-heating process described in US Pat. No. 4,712,172. In these processes, ink that does not contribute to image printing is ejected from the print head to recover the ink ejection state. Hereinafter, such ejection recovery is also referred to as “preliminary ejection”.

By performing such processing, the ejection characteristics of the recording liquid during the recording operation are improved. However, it is not sufficient to obtain the best recording state from the initial stage of using the recording head. The repetitive high-temperature heat generation of the heater in the recording mode including the pre-ejection process and the pre-heating process described above causes phase change, stress change, oxidation, and composition change of the heater material, and the heater material has a resistance value. Changes occur. Also, the resistance distribution of the heater material changes due to the interface resistance in the boundary region between the heater material and the wiring portion (electrode), and furthermore, the diffusion phenomenon between the two. Therefore, in order to improve those problems, for example, Japanese Patent Application Laid-Open No. 2-78554 proposes a method of manufacturing a liquid jet recording head. The method is to apply a sufficient electric signal to the heater to stabilize the resistance value of the heater material during the aging process,
This is a method of heating a heater material by discharging ink.

As described above, a preliminary discharge process for discharging ink not contributing to image recording from an ink jet recording head mounted on an ink jet recording apparatus, and a heating process for a heater material during an aging process in manufacturing an ink jet recording head. As a result, a good and stable ink ejection state can be always obtained even in long-time printing.

[0011]

In recent years, the handling of image images has increased, and the demand for high-quality color recording, particularly, recording of halftone images has been increasing.

As a method of expressing halftone in an ink jet recording apparatus, there is a method of expressing the number of ink droplets ejected per predetermined pixel on a recording medium (pseudo halftone expression in binary). Further, as another expression method, a recording head having a different ejection amount or a plurality of recording heads capable of ejecting inks having different densities are used,
There is a method of expressing a halftone by selecting and driving a recording head according to the halftone. However, according to these methods, there is a possibility that the resolution cannot be significantly increased, and the size of the printing apparatus may be increased because a plurality of printing heads are used. Therefore, there is a demand for an ink jet recording apparatus capable of performing high-resolution recording at the same time as reducing the space of the recording apparatus at low cost by changing the ejection amount in multiple steps in one recording head.

As a configuration for achieving the above object, for example, Japanese Patent Publication No. 62-48585 discloses a gradation recording method for realizing high-quality recording by modulating the size of an ink droplet to be ejected. . In the recording method, a plurality of heaters having different areas are arranged in one ink channel, and each heater is independently controlled and driven.

However, there are several problems in realizing a so-called multi-heater ink jet recording head in which a plurality of heaters are arranged in one ink flow path.

First, not only can the ink discharge amount be variable, but also in order to perform higher-quality printing, the ink discharge speed is improved so that immediately after ink discharge when ink is not discharged for a long time. There is a demand to improve the ejection reliability and to improve the landing accuracy of ink droplets. In particular, when an ink jet recording head having a multi-heater is used in an ink flow path forming one nozzle, when a relatively small volume droplet is ejected from a relatively large ejection port, a small droplet is ejected. It may be difficult to increase the ejection speed. In such a case, there is a possibility that the ejection of the ink is disturbed due to an accidental bubbling defect or a state near the ejection port. A small droplet discharge heater with a small heater area can easily affect the ink discharge even with a slight foreign matter on the heater surface. In the preliminary discharge process as it is and the heating process in the aging process, the small droplet discharge heater In some cases, the ejection stability was insufficient. In addition, as an effect of the preliminary discharge treatment or the heat treatment in the aging process, there is a case where extraneous matters such as foreign substances on the heater surface are removed. However, in a multi-heater ink jet recording head, when a plurality of heaters are simultaneously driven to perform the above-described preliminary ejection processing or the heating processing in the aging process, the position at which bubbles for ejecting ink are defoamed, Often not on the center of the heater. Therefore, the effect of cavitation for removing kogation and foreign matter on the heater surface is often small.

An object of the present invention is to perform an ejection recovery process and an aging process on an ink jet recording head having a plurality of electrothermal transducers for one ink flow passage, so that a plurality of electrothermal transducers can be effectively processed. It is an object of the present invention to more stably maintain an ejection characteristic represented by an ink ejection speed and an ejection amount during an image recording operation in which an ink is ejected by driving an electrothermal transducer.

[0017]

An ink jet recording apparatus according to the present invention is characterized in that a plurality of electrothermal converters provided for one ink liquid path generate heat to cause the ink in the ink liquid path to foam. In an ink jet recording apparatus that records an image on a recording medium by using an ink jet recording head capable of discharging ink from an ink discharge port communicating with the ink liquid path, ink that does not contribute to image recording is discharged from the ink jet recording head. Let me
When recovering the ejection state of the ink, a control unit is provided for changing a shift amount of a drive signal applied to the plurality of electrothermal transducers to change a shift amount of heat generation timing of the plurality of electrothermal transducers. It is characterized by having.

In the ink jet recording apparatus of the present invention, the method for recovering the ejection of the ink is such that the ink in the ink liquid path is foamed by heat generated by a plurality of electrothermal transducers provided for one ink liquid path. In an ejection recovery method for an ink jet recording apparatus that records an image on a recording medium by using an ink jet recording head capable of discharging ink from an ink discharge port communicating with a liquid path, an ink that does not contribute to recording of an image from the ink jet recording head At the time of ejection recovery for restoring the ejection state of the ink, by changing the shift amount of the drive signal applied to the plurality of electrothermal transducers, the shift amount of the heat generation timing of the plurality of electrothermal transducers. It is characterized by changing.

According to the method of manufacturing an ink jet recording head of the present invention, the ink in the ink liquid path is foamed by the heat generated by a plurality of electrothermal transducers provided for one ink liquid path. In a method of manufacturing an ink jet recording head capable of discharging ink from an ink discharge port communicating with a path, a driving signal applied to the plurality of electrothermal transducers when discharging ink from the ink jet recording head for aging processing The amount of shift of the heat generation timing of the plurality of electrothermal transducers is changed by changing the amount of shift.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings. The present invention is not limited to the following embodiments. In the present embodiment, ink is described as an example of a liquid to be ejected, but the present invention is not limited to this, and any liquid that can be ejected using the present invention can be used. I do not care.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
FIG. 5 is a schematic cross-sectional view of an ink flow path portion of the recording head 1 according to the embodiment.

In the recording head 1, a plurality of ink channels 12 are arranged in parallel at a density of 360 dpi.
Each discharge port 11 communicates with a common liquid chamber 13. In addition, two heaters (electrothermal converters) SH1 and SH2 are provided in each ink flow path 12, respectively. The length L of each heater SH1, SH2 is equal to 95μ
m. The width W1 of the heater SH1 is 30 μm,
The width W2 of the heater SH2 is 30 μm. The width W3 of each ink channel 12 was 58 μm, and the height was 40 μm.

The ink supplied from an ink tank (not shown) is temporarily held in a liquid chamber 13 and further enters each of the ink flow paths 12 by a capillary phenomenon to form a meniscus at the discharge port 11. Thereby, the ink flow path 12 is maintained in a state of being filled with the ink. In this state, a drive pulse is applied to the heaters SH1 and SH2 to generate heat and give thermal energy to the ink, thereby causing a state change accompanied by a rapid change in volume (generation of bubbles) in the ink. The discharge port 11 is operated by the action force based on the state change
Is ejected from the printer.

The ink jet recording head 1 used in this embodiment
By modulating the amount of ink ejected when the heater SH1 alone is driven and when the two heaters SH1 and SH2 are simultaneously driven, it is possible to obtain a higher definition image.

The present inventors have made two heaters SH1 and SH2 for the above-mentioned preliminary ejection performed during recording such as printing.
The effect was examined by shifting the drive timing of the electric signal applied to the device. FIG. 2 is an explanatory diagram of the preliminary ejection drive studied in this example, where ΔT is a shift amount. FIG.
(A) shows the shift amount ΔT in one preliminary ejection.
And the relationship between the number of drive pulses for the preliminary ejection and the cavitation position when the preliminary ejection is performed. FIG.
(B)

[0026]

[Outside 1]

FIG. In this example, the ink droplet was ejected 100 times from the ejection port 11 at the time of one preliminary ejection. At this time, the voltage applied to the heaters SH1 and SH2 is 10
The application timing of the drive pulse for each 0 pulse was shifted in five stages. That is, the heaters SH1 and SH2
After the drive pulse is applied to the heater SH2 for 20 pulses in the first stage applied to each of the above, the drive pulse is applied to the heater SH1 5 μsec later. For the next second stage of 20 pulses, the shift amount is set to 2 μsec.
The next third stage of 20 pulses corresponds to heaters SH1 and SH
2 at the same time. For the next 20 pulses of the fourth stage,
Conversely, after applying a drive pulse to the heater SH1,
A drive pulse is applied to the heater SH2 after μsec, and the shift amount is set to 5 μsec for the next 20 pulses in the fifth stage.
c. As described above, by changing the shift amount of the drive timing of the heaters SH1 and SH2 in five steps, the position of the cavitation generated at a fixed position in the conventional drive can be shifted.

FIG. 4 shows a change in the ink ejection amount with respect to the number of driving pulses applied to the ink jet recording head 1.

In FIG. 4, A indicates the change characteristic of the conventional example, and B indicates the change characteristic of the present example. Both of them show the change of the printing or the like at a preset preliminary ejection interval similarly to the conventional preliminary ejection processing. The recording operation is interrupted, and preliminary ejection is performed. However, in the former case of the preliminary discharge driving, a driving pulse (electric signal) is simultaneously applied to the heaters SH1 and SH2. In the latter case, as described above, the preliminary ejection is performed by the preliminary ejection drive that changes the shift amount of the drive timing of the heaters SH1 and SH2.

As is apparent from FIG. 4, in the conventional example, the ink discharge amount starts to decrease around the time when the number of drive pulses to be applied exceeds 10 ^5, and when the number of drive pulses to be applied is 10 ⁷ , A decrease of the ink discharge amount of 20% or more was observed. This is because sand-like kogation or cracking of the kogation has occurred on the upper surface of the heater. On the other hand, in the ink jet recording head which performed the preliminary ejection driving of the present example, no decrease in the ink ejection amount was observed. This is considered to be because cavitation was effectively generated and foreign matter on the heater surface or the like was removed.

In addition, the heater material is heated during the aging process in the manufacturing process by the heater drive in which the shift amount of the heater drive timing is changed as in the present embodiment. Then, an image was recorded by dots formed by landing of ink droplets, using an ink jet recording head immediately after being manufactured by such a process. Then, a reference least-square line was obtained from each of the vertical and horizontal lines in the recorded image, and then the amount of deviation of the dot formed by landing of the ink droplet from the least-square line was measured by microscopic observation.
The evaluation results of the recording quality in five levels from “1 (bad)” to “5 (good)” by such a method of measuring the landing point error of the ink droplet.
Is shown in FIG.

In contrast to the conventional aging process by simultaneous timing driving of a plurality of heaters (characteristic C in FIG. 5), the aging process of the heater driving in which the shift amount of the application timing is changed as shown in FIG. When the characteristic D) is performed, the recording quality in the initial stage of manufacturing is improved.
This is because the cavitation force generated by the defoaming of the bubbles generated on the heater surface at the time of ink ejection is generated on a wider range of the heater surface by the heater drive with the timing shifted as in the above example, and the cavitation force is reduced. It is considered that more stable ink ejection can be performed in order to remove foreign matters adhering to the heater surface at the time of manufacturing an ink jet recording head or the like. Also, in such an aging process,
As the drive pulse (electric signal) applied to the heater, the drive pulse (electric signal) applied during normal recording is
A drive pulse with a large heat energy generated in the heater may be applied. As a result, the size of bubbles generated on the heater at the time of ink ejection can be increased, and the cavitation force generated by the defoaming of the bubbles can be similarly increased, so that the effect of the cavitation force can be further increased.

(Second Embodiment) FIG. 6 shows a second embodiment of the present invention.
FIG. 5 is a schematic cross-sectional view of an ink flow path portion in the inkjet recording head according to the embodiment.

In this embodiment, each of the heaters SH1 and SH
The width of 2 is W1 = W2 = 20 μm and their areas are equal. The two heaters SH1 and SH2 are equidistant from the discharge port 11. Other dimensions are the first
This is the same as the embodiment.

In this embodiment, the same heater drive as in the first embodiment was performed. FIG. 8 shows a change in the ink ejection amount with respect to the number of driving pulses applied to the ink jet recording head, similarly to FIG. 4 of the above-described embodiment.

As is clear from FIG. 8, in the conventional example, when the number of applied driving pulses exceeds 10 ⁵ ,
When the number of applied pulses was 10 ⁷ , a decrease of 30% or more was observed. On the other hand, in the ink jet recording head in which the preliminary ejection drive in which the shift amount of the heater drive timing was changed as in the present example, the decrease in the ink ejection amount was suppressed to 10%.

FIG. 7A illustrates the relationship between the shift amount ΔT and the cavitation position, and FIG. 7B illustrates the cavitation position. In the configuration in which the heaters SH1 and SH2 are arranged in parallel to the discharge port 11 as in this example, it is difficult to increase the width of each of the heaters SH1 and SH2. Therefore, even if the driving is performed with the application timing of the driving pulse shifted, the cavitation position is hardly changed largely as compared with the case of the above-described first embodiment, and the effect is slightly smaller. However, also in the case of this example, the effect of removing the kogation due to the change in the cavitation position is sufficient.

(Other Embodiments) Further, it was confirmed that the arrangement of the heaters SH1 and SH2 as shown in FIGS. 9 and 10 has the same effect. As described above, the arrangement mode and the number of heaters are not particularly limited. Further, a plurality of heaters having different sizes may be provided. Also,
The heater drive pulse may have a different pulse width or magnitude depending on the amount of heat generated by each heater. Further, in the ejection recovery process and the aging process, regarding the application timing of the drive pulse to the plurality of heaters,
At least the application start timing may be changed.

(Structural Example of Recording Apparatus) FIG. 11 shows a structural example of the entire ink jet recording apparatus according to the present invention.

In the ink jet recording apparatus 300,
The carriage 400 is slidably engaged with two guide shafts 304 and 305 extending parallel to each other. The carriage 400 is reciprocated in the main scanning direction indicated by an arrow A along guide shafts 304 and 405 by a driving motor and a driving force transmission mechanism (not shown) such as a belt for transmitting the driving force. On the carriage 400, the above-described symbol head and an ink tank 151 as an ink container for storing ink used by the head are mounted.

In the recording head, for example, 64 ink ejection ports 11 similar to the recording head 1 described above are arranged on the surface of the recording head facing the paper 306 so as to be arranged in the transport direction of the paper 306. Is formed. As described above, the recording head is provided with the ink flow passages 12 communicating with the respective ejection openings 11, and the heater (electricity generator) that generates thermal energy for ink ejection corresponding to each ink flow passage 12 is provided. Heat converters) SH1 and SH2 are provided.

After the paper 306 is inserted from the insertion port 311 provided at the front end of the apparatus, the transport direction is reversed, and the paper is fed by the feed roller 309 in the sub-scanning direction indicated by an arrow B perpendicular to the main scanning direction A. Is transported to the lower part of the moving area of the carriage 400 along the path. The recording head mounted on the carriage 400 moves with the movement of the recording head.
The image is printed on a print area on the sheet 306 supported by the platen 308.

As described above, the printing operation of one line accompanying the movement of the carriage 101, that is, the printing operation of the width corresponding to the width of the ejection port array of the recording head, and the paper 30
6 while repeating the feeding operation of
The print is made entirely. Paper 306 after printing
Is discharged to the front of the device.

At the left end of the movable area of the carriage 400, there is provided a recovery system unit 310 which can face the lower part of each recording head on the carriage 400. The recovery system unit 310 can perform operations such as capping the ejection openings of each recording head and suctioning ink from the ejection openings of each recording head during non-printing or the like.
Further, a predetermined position on the left end side of the movable area of the carriage 400 is set as a home position of the recording head. The recovery system unit 310 can also receive the ink preliminarily ejected from the recording head in the cap, and then process the ink as waste ink.

On the other hand, an operation unit 307 provided with switches and display elements is provided at the right end of the apparatus. The switches here are used when turning on / off the apparatus power, setting various print modes, and the like, and the display element plays a role in displaying various states of the apparatus.

(Others) It should be noted that the present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for performing ink ejection, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding the nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As this pulse-shaped drive signal, those described in U.S. Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44,558 which disclose a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, 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 medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, even in the case of the serial type as described above, a recording head fixed to the apparatus main body or an electric connection with the apparatus main body or ink from the apparatus main body by being attached to the apparatus main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.

Further, it is preferable to add ejection recovery means for the recording head, preliminary auxiliary means, and the like as the constitution of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

The type and number of recording heads to be mounted are not limited to those provided only for one color ink, for example, and for a plurality of inks having different recording colors and densities. A plurality may be provided. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature may be used. In general, the ink jet method generally controls the temperature of the ink itself within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, the ink may be in a liquid state. In addition, in order to positively prevent the temperature rise due to thermal energy by using the energy of the state change from the solid state of the ink to the liquid state, or to prevent the ink from evaporating, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start to solidify when reaching the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, it is also possible to adopt a form in which the sheet is opposed to the electrothermal converter in a state where it is held as a liquid or solid substance in the concave portion or through hole of the porous sheet. 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, the form of the ink jet recording apparatus of the present invention is not limited to those used as image output terminals of information processing equipment such as computers, copying apparatuses combined with readers and the like, and facsimile apparatuses having a transmission / reception function. It may take a form.

[0055]

According to the present invention, when an ink jet recording head having a plurality of electrothermal transducers for one ink flow path is mounted on an ink jet recording apparatus,
In the ejection recovery processing of the ink jet recording head and the aging processing at the time of manufacturing the ink jet recording head, the application timing of the drive signal applied to each electrothermal transducer is shifted. As a result, long-term deterioration of the recording quality can be reduced, and the recording quality in the initial stage after manufacturing can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an ink flow path portion of a print head according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of an application timing of a drive signal to the heater of FIG.

FIG. 3A is an explanatory diagram of a drive signal application timing according to the first embodiment of the present invention, and FIG. 3B is an explanatory diagram of a cavitation position that changes according to the application timing.

FIG. 4 is an explanatory diagram of a relationship between the number of application of drive pulses and the ejection amount of ink according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram of an initial state of recording quality by an aging process according to the first embodiment of the present invention.

FIG. 6 is a sectional view of an ink flow path portion of a print head according to a second embodiment of the present invention.

FIG. 7A is an explanatory diagram of a drive signal application timing according to a second embodiment of the present invention, and FIG. 7B is an explanatory diagram of a cavitation position that changes according to the application timing.

FIG. 8 is an explanatory diagram of a relationship between the number of application of drive pulses and the ejection amount of ink according to a second embodiment of the present invention.

FIG. 9 is a sectional view of an ink flow path portion of a print head according to another embodiment of the present invention.

FIG. 10 is a sectional view of an ink flow path portion of a print head according to still another embodiment of the present invention.

FIG. 11 is a schematic perspective view of an ink jet recording apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording head 11 Discharge port 12 Ink flow path 13 Liquid chamber SH1, SH2 Heater (electric heat conversion body)

Claims (16)

[Claims] 1. A method according to claim 1, wherein a plurality of electrothermal transducers provided for one ink liquid path generate heat so that the ink in the ink liquid path is foamed, so that ink is discharged from an ink discharge port communicating with the ink liquid path. In an ink jet recording apparatus that records an image on a recording medium by using an ink jet recording head capable of ejecting ink, the ink jet recording head ejects ink that does not contribute to image recording to recover the ink ejection state. An ink jet recording apparatus comprising: control means for changing a shift amount of a drive signal applied to the plurality of electrothermal transducers to change a shift amount of heat generation timing of the plurality of electrothermal transducers. . 2. The control unit according to claim 1, wherein the driving signal is
2. The ink jet recording apparatus according to claim 1, wherein drive pulses having substantially the same width are applied to the plurality of electrothermal transducers while being shifted. 3. The ink-jet recording apparatus according to claim 1, wherein the control unit changes at least the application start timing of the drive signal applied to the plurality of electrothermal transducers. 4. The ink-jet recording apparatus according to claim 1, wherein the plurality of electrothermal transducers are arranged so as to be shifted in a length direction of the ink flow path. 5. The ink jet recording apparatus according to claim 1, wherein the plurality of electrothermal transducers are arranged so as to be shifted in a width direction of the ink flow path. 6. An ink jet recording apparatus according to claim 1, further comprising a cap for receiving ink discharged from said ink jet recording head and not contributing to image recording. 7. A first moving means for relatively moving the ink jet recording head and the recording medium in the main scanning direction, and moving the ink jet recording head and the recording medium in a sub scanning direction intersecting the main scanning direction. Second to move relatively
2. The ink jet recording apparatus according to claim 1, further comprising: a moving unit. 8. An ink jet printer according to claim 1, wherein a plurality of electrothermal transducers provided for one ink liquid path generate heat so that the ink in the ink liquid path is foamed, so that the ink is discharged from an ink discharge port communicating with the ink liquid path. In an ejection recovery method of an inkjet recording apparatus that records an image on a recording medium using an inkjet recording head capable of ejecting ink, an ink that does not contribute to image recording is ejected from the inkjet recording head to change the ejection state of the ink. An ink jet recording apparatus, wherein, at the time of ejection recovery to be recovered, a shift amount of a drive signal applied to the plurality of electrothermal transducers is changed to change a shift amount of heat generation timing of the plurality of electrothermal transducers. Ejection recovery method. 9. The ejection recovery method for an ink jet recording apparatus according to claim 8, wherein a drive pulse having substantially the same width is applied to the plurality of electrothermal transducers as the drive signal while being shifted. 10. The ejection recovery method for an ink jet recording apparatus according to claim 8, wherein at least application start timing of the drive signal applied to the plurality of electrothermal transducers is changed. 11. The ink in the ink passage is foamed by the heat generated by a plurality of electrothermal transducers provided for one ink passage, so that the ink is discharged from an ink discharge port communicating with the ink passage. In the method of manufacturing an ink jet recording head capable of ejecting, when the ink is ejected from the ink jet recording head for an aging process, a shift amount of a drive signal applied to the plurality of electrothermal transducers is changed, A method for manufacturing an ink jet recording head, wherein a shift amount of heat generation timing of a plurality of electrothermal transducers is changed. 12. The method according to claim 11, wherein a drive pulse having substantially the same width is applied to the plurality of electrothermal transducers as the drive signal while being shifted. 13. The method according to claim 11, wherein at least application start timing of the drive signal applied to the plurality of electrothermal transducers is changed. 14. The method according to claim 11, wherein the plurality of electrothermal transducers are arranged so as to be shifted in a length direction of the ink flow path. 15. The method according to claim 11, wherein the plurality of electrothermal transducers are arranged so as to be shifted in a width direction of the ink flow path. 16. The method according to claim 1, wherein the drive signal applied to the electrothermal transducer during the aging process causes the electrothermal transducer to generate more thermal energy than during the recording operation using the ink jet recording head. The method for manufacturing an ink jet recording head according to claim 11, wherein