JPH0439052A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To succeedingly maintain a good recording state even if an elapse time causes a variation to occur in the ejection output of a recording head by providing a control means for supplying an electric signal of a ejection allowable limit to eject elements per group at every predetermined timing. CONSTITUTION:For every test, an arithmetic device 25 sorts the number of an ejection element and that of a non-ejection element by referring to a signal from an electric signal generator 21 and a signal from an ejection element detection means 23. An instructing means 27 provided with a counter instructs a test printing to a recording head 1 through a control circuit 22 at a predetermined timing. When an ejection or non-ejection state is detected by a test printing, the number of an ejection element and the pulse width and voltage at which the element is ejected or not ejected are stored in a memory 26 in accordance with a flow shown by a full line. At the time of recording, the control circuit 22 sets an appropriate pulse width and voltage for an electric signal per ejection element in accordance with a flow shown by a broken line, i.e. information stored in the memory 26. The electric signal is supplied to an ejection element group of the recording head 1. Then, a recording image 27 without irregularities is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording device, and particularly to an inkjet recording device having a recording head equipped with a large number of ink ejection ports.

(The following is a blank space) [Prior Art] In a recording apparatus using an inkjet recording head, an inkjet recording head in which a plurality of ink ejection ports are arranged is generally used in order to perform high-speed recording.

However, in such a recording head, the ejection elements (
It is difficult to reliably manufacture the ejection ports (consisting of the ejection ports, the liquid paths provided corresponding to the ejection ports, and the electrothermal converters) uniformly, and it is inevitable that some variation in the characteristics of the ejection elements will occur. This is the current situation. Therefore, the ejection output varies due to non-uniformity of characteristics among the ejection elements, and if the ejection elements with low ejection output are left for a long time without recording, the ink viscosity increases and the ink tends to fail.

In order to solve this problem, there is a known publication in which uniform ejection characteristics are obtained by correcting the electrical signals applied to each ejection element.

This publication states that test printing is performed by gradually changing the electrical signals supplied to each ejection element from the initial setting conditions, and in each case, ejection elements that are not ejecting are detected to determine variations in ejection output. Appropriate pulse widths are set again for each group of ejection elements classified by ejection output, and drive electric signals are applied to each group independently, and variations in ejection output are corrected by the above procedure.

[Problem to be solved by the invention]

However, with the above-mentioned technology, even if variations in ejection output can be corrected once, for example, as the print head is used, precipitates and dust from the ink may adhere to the vicinity of the ink ejection orifices, resulting in the individual ejection output being affected. Changes may occur. However, in such a case, the initially set correction amount cannot be used, and a particular ejection element tends to fail in ejection.

Conventionally, this non-ejection condition was found during printing and it took a long processing time to correct it, and in severe cases, it could not be recovered by the above correction.

In view of such problems, an object of the present invention is to provide an inkjet recording apparatus that can continue to maintain a good recording state even if variations occur in the ejection output of the recording head over time. .

[Means to solve the problem]

In order to achieve such an object, the present invention includes a plurality of ejection elements that eject ink from an ejection port using energy generated in response to an electric signal from an energy conversion means to form flying ink droplets. a recording head that performs recording on a recording material using the plurality of ejection elements; an ejection element detection unit that detects ejection 8 or non-ejection 8 of ink from the ejection ports with respect to the plurality of ejection elements; control means for controlling the pulse width and/or voltage of the electrical signal supplied to the plurality of ejection elements based on detection data from the detection means; The present invention is characterized by comprising a command means for commanding execution of correction of the pulse width and voltage of the electric signal based on the electric signal.

[For production]

According to the present invention, ejection elements that are ejecting or non-ejecting can be classified each time via the ejection element detection means by supplying ejection elements with varying electric signals, and the control means can determine the ejection possible limit for each classification. By supplying an electric signal, it is possible to adjust so that stable ejection can be obtained from all the ejection elements. Moreover, since this adjustment is performed at predetermined intervals, each adjustment can be made easily and reliably, and the lifespan of worst-case conditions such as non-discharge can be extended.
We were able to improve the throughput of the entire device.

[Examples] Examples of the present invention will be described below in detail and specifically based on the drawings.

FIG. 1 shows an embodiment of the invention.

In Figure 1, IBk, IY, LM, and IC are bubble jet recording heads that correspond to black, yellow, magenta, and cyan ink colors, respectively.
Each of them has an electrothermal conversion element as an ejection energy generating means, and the ink droplets are ejected from the ejection port using the bubbles generated in the ink when energized as a pressure source, and are fixed to the block 2. Note that each recording head has, for example, 4736 ejection ports arranged at a density of 400 dpi. Furthermore, a reading head 51 is fixed to the block 2 for detecting the number of ejection elements that are ejecting or not ejecting.

3 is a capping unit, and by pulling up block 2 to the position shown by the dotted chain line in the figure during non-recording, such as during standby, unit 3 is connected to the recording heads IC to IB.
Cap it facing k.

Further, in the capping unit 3, when the circulation is restored, a recovery pump (not shown) serves as a tray to receive waste ink sent from an ink supply system and pushed out from an ejection port, and the waste ink is guided to a waste ink tank (not shown).

Reference numeral 4 denotes an endless charged adsorption belt for conveying a recording sheet that is arranged facing each of the recording heads IBk, ly, 1m, and lc at a predetermined interval, and 5 refers to each recording head via the charged adsorption belt 4. This is a back platen placed opposite to the back platen.

Reference numeral 6 designates a feeding cassette that stores recording sheets 7 such as plain paper and is detachably attached to the main body of the apparatus, and reference numeral 8 designates a pickup roller that feeds and feeds only one recording sheet 7 on the uppermost surface. A conveyance roller 9 conveys the recording sheet 7 sent out from the pickup roller 8 to the conveyance path 10, and a conveyance roller 11 is disposed on the exit side of the conveyance path 10.

13 and 14 are heaters and fans that dry and fix ink droplets attached to the recording sheet 7 during recording using hot air; 15 is a discharge roller that discharges the recording sheet 7 after fixing to the outside of the apparatus; and 16 is a discharged recording sheet. This is a tray that stores items 7 in sequence.

Next, the operation of the embodiment with the above configuration will be explained.

First, the recording operation will be explained. When an operation to start recording is performed, a recording sheet 7 of a specified size is sent out from the feeding cassette 6 by a pickup roller 8. The recording sheet 7 that has been sent out is transferred to the right side of the conveyance roller 9 and the conveyance roller 1
1 rotates in a pre-charged state and is placed on the charged adsorption belt 4 which is made flat by the back platen 5. The tip of the recording sheet 7 is the head l.
c.

In conjunction with the arrival at the lower part of each of la, ly, and lBk, the electrothermal transducer of each recording head is driven according to the image data, and this driving causes ink droplets according to the image information to reach the ejection port. The liquid is ejected onto the surface of the recording sheet 7 to perform recording.

If the recording sheet 7 has poor hygroscopicity, the droplets attached to the surface will not dry and will be rubbed, causing print stains.
3 and fan 14 to perform forced drying and fixation. The recording sheet 7 that has been fixed is discharged onto a tray 16 by a discharge pressure roller 15.

As mentioned above, cyan, magenta, yellow,
A color image is formed by applying a recording signal corresponding to each head to the recording head corresponding to black ink.

Next, the ejection principle of the inkjet recording head used in the apparatus of this embodiment will be explained.

A recording head applied to an inkjet recording device generally includes a fine ink ejection opening liquid path, an energy acting part provided in a part of this liquid path, and a droplet forming energy applied to the liquid (ink) in the acting part. It is equipped with an energy generating means for generating .

Energy generating means for generating such energy include recording methods using electromechanical transducers such as piezo elements, irradiating electromagnetic waves such as lasers, causing the ink to absorb it and generate heat, and the effect of the heat generation. There are recording methods using an energy generating means for ejecting ink droplets and making them fly, and recording methods using an energy generating means for ejecting ink by heating the ink with an electrothermal conversion element.

Among these, the recording head used in the inkjet recording method, which uses thermal energy to eject ink, is able to arrange ink ejection ports in a high density array for ejecting ink droplets for recording and forming flying droplets. It is possible to record with high resolution. In addition, a recording head that uses an electrothermal transducer as an energy generating means,
It is easy to make the overall size of the recording head compact, and it can fully utilize the advantages of IC technology and micro-processing technology, which have seen remarkable technological advances and improved reliability in the semiconductor field in recent years. Because it is easy to create a two-dimensional shape (two-dimensional), it is possible to provide an inkjet recording head that can be easily manufactured with multiple ejection ports/high-density packaging, has high productivity in large quantities, and is inexpensive to manufacture. It is.

Inkjet recording heads that use electrothermal conversion elements as energy generating means and are manufactured through a semiconductor manufacturing process generally have a liquid path corresponding to each ejection port, and each liquid path is connected to a droplet. An electrothermal transducer is provided as a means for applying thermal energy to the ink and ejecting the ink from the corresponding ink ejection opening to form flying droplets. The structure is such that ink is supplied from a communicating common liquid chamber.

FIG. 2 shows an example of the above-mentioned inkjet recording head, in which electrothermal transducer elements 103 are formed on a substrate 102 through semiconductor manufacturing process steps such as etching, vapor deposition, and sputtering. Electrode 104. Liquid channel wall 105, top plate 10
It consists of 6. Recording ink 112 is supplied into the common liquid chamber 10g of the recording head 1 from a liquid storage chamber (not shown) through an ink supply pipe 107.
is the connector for the ink supply pipe. The ink 112 supplied into the common liquid chamber 108 flows through the liquid path 110 due to capillary action.
The ink is stably maintained by forming a meniscus at the ink discharge port 111 at the end of the liquid path. By energizing the electrothermal transducer 103, the ink on the surface of the electrothermal transducer is heated, a bubbling phenomenon occurs, and the energy of the bubbling causes droplets to be ejected from the ink ejection ports 111. With the configuration described above, the discharge port density is 40
A multi-ejection orifice inkjet recording head in which high-density ejection elements such as 0DPI are arranged is formed.

FIG. 3 shows the structure of this multi-ejection orifice elongated recording head and ink supply means. In this figure, l is the recording head, and the ejection ports 111 shown in this figure are arranged in number all over the recordable width of the target recording material, and each of the ejection ports By selectively driving an electrothermal transducer provided in a liquid path (not shown) leading to the head 111, ink can be ejected, and printing can be performed without main scanning of the head itself.

55 is an ink supply tank for supplying ink to the recording head 1, 56 is a main tank for replenishing the supply tank 55 with ink, and the ink is supplied from the supply tank 55 to the common liquid chamber 108 of the recording head 1 through a supply pipe 57. Furthermore, when replenishing the recording liquid, it is possible to replenish the supply tank 5 with recording liquid from the main tank 56 via a one-way replenishment rectifier valve 58 with a recovery pump 59.

Reference numeral 60 denotes a traffic recovery rectifier valve used during a recovery operation to restore the ejection function of the recording head l; 61 a circulation pipe in which the recovery rectifier valve 60 is interposed; The electromagnetic valve 63 interposed in the first supply pipe 57 is an air vent valve for the supply tank.

In the recording head 1 and its ink liquid supply system and recovery system configured in this way, the solenoid valve 62 is kept open during recording, and the ink flows from the supply tank 55 into the common liquid chamber 108 due to its own weight. is supplied to the liquid chamber 10.
g to the ink discharge port 111 via a liquid path (not shown).

Further, during a recovery operation performed to remove air bubbles remaining in the common liquid chamber 108 and the supply system and to cool the recording head l, the recovery pump 59 is driven to pump ink to the circulation pipe 6.
1 into the common liquid chamber 10g, drive the recording head 1 at the same time, push out air bubbles together with the ink from the ejection port 111, and return the ink from the common liquid chamber iog to the supply tank 55 through the first supply pipe 57 for circulation. I can do it.

Furthermore, at the time of initial filling of the liquid path, etc., with the electromagnetic valve 62 closed, the pump 59 forces the ink into the common liquid chamber 108 through the circulation pipe 61, and discharges the ink from the discharge port 111 as the bubbles are discharged. I can do it.

FIG. 4 shows the configuration of a recording head drive control circuit according to the present invention, where 21 is an electric signal generator that generates an electric signal to be supplied to the recording head 1, and 22 is from the electric signal generator 21. This is a control circuit that can set the pulse width and voltage of the pulse signal supplied to the recording head 1 based on the electric signal of the controller and the command signal from the command means 27. In addition, 23 is a test print 24 performed by the recording head 1 at the time of ejection failure detection, which is carried out at predetermined timings as will be described later. The ejection element detection means 25 detects the numbers of ejection elements and non-ejection elements using the signal from the electric signal generator 21 and the signal from the ejection element detection means 23 every time the above-mentioned test is performed. A computing unit for classification, 26 a memory, 27 a tire and a counter, and a control circuit 2 at a predetermined timing.
This is a command means for instructing the recording head 1 to perform a test print via the recording head 2.

In this way, when ejection or non-ejection is detected by test printing, the memory 26 stores which numbered ejection element ejected or ejected or failed with what pulse width and voltage according to the flow shown by the solid line. Further, during recording, the control circuit 22 sets an appropriate pulse width and voltage for the electric signal for each ejection element according to the flow shown by the broken line, that is, the information stored in the memory 26, and supplies it to the ejection element group of the recording head 1. Even recorded image 27
is output.

Next, a specific example of controlling the drive of the recording head configured as described above so as to obtain stable ejection will be described.

Now, in the above-mentioned full-line multi-print head, the ejection elements A, B, and C shown in Table 1 are used.

Assume that there are differences in characteristics such as D...

Table 1 However, here, it is assumed that the ejection elements A to D are commonly supplied with ink (viscosity of about 3 cp) under a certain condition, with a constant voltage (about 25 V) and a constant pulse width (4.5 μs, 5.
This represents the difference in ejection characteristics that occurs between each ejection element when driving for 0 μs, -・-, 7, Ous).As is clear from the table, element A requires the largest amount of energy to eject. , and a voltage application time (pulse width) of 6.5 μs or more is required, whereas with the D element, the energy required for ejection requires a minimum voltage application time of 5.0 μs or more. It shows.

By the way, when determining the driving conditions of the recording head, it is necessary to always obtain stable ejection and to keep the failure rate as low as possible.

However, the conditions for stable ejection are those that guarantee ejection even when the printing environment changes, non-printing time becomes longer, and factors that inhibit ejection, such as increases in ink viscosity, increase. That is, it means that the ejection force is large. Therefore, as a measure of the magnitude of the ejection force, Figure 5A shows the relationship between the maximum ejectable ink viscosity and the voltage application time.In this way, when the ink viscosity is 3 cp, the D element applies a voltage of 5.0 μs or more. The A element ejects in a voltage application time of 6.5 μs or more. Further, when the ink viscosity is 7 cp, the D element ejects the ink with a voltage application time of 6.5 μs or more, and the A element ejects the ink with a voltage application time of 8.0 μs or more. Furthermore, the fact that the failure rate is small can be expressed by the number of pulses until a failure occurs, as shown in Figure 5B, and there is a relationship that the longer the voltage application time, that is, the pulse width, the smaller the number of pulses until a failure occurs. be. Therefore, in order to reduce the failure rate and guarantee the number of pulses of 10" or more, the voltage application time should be set to a pulse width of 6.5 μs or less for the D element, and 8" for the A element.
．． It is necessary to set the pulse width to 0 μs or less. That is,
The conditions for stable ejection without failure are that the maximum ink viscosity that can be ejected is 7 cp or more and the number of ejectable pulses is 1.
The voltage application time that satisfies this requirement is 6.5 μs for D element, and 8 μs for A element.
．． 0 μs, and it can be seen that the ejection characteristics of the two are different.

Therefore, in the present invention, the difference in the ejection characteristics of the ejection elements is detected, and the drive conditions are changed independently for each element according to the detection result.The timing of this detection will be described later.

In the following, regarding the characteristics of each ejection element shown in Table 1, an element having characteristic A ejects in 6.5 μs. Elements with characteristic B eject in 6.0 μs, elements with characteristic C eject in 5.5 μs, and elements with characteristic D eject in 5.0 μs. be included in the element group.

Therefore, as a first example, an algorithm is shown in FIG. 6 when using ink with a certain condition, such as a viscosity of 3 cp, as described above.The procedure shown here is set as described later. First, in step S1, the pulse width Tpw is initially set to 4.5 μs, and then, in step S2, the ejection conditions are initialized. Note that initializing the ejection conditions includes performing a recovery operation, and refers to setting various conditions related to ejection, such as head drive voltage and temperature control, to optimal predetermined conditions.

Next, the pulse width Tpw is set to 4.5 μs in step S3, and recording is performed in step S4. In this case, the pulse width TPw is increased one after another in steps of 0.5 μs and ejection is performed, so From then on, printing is performed only with the ejection elements that failed to eject the first time. Then, in step S5, the number of the element to which ejection was performed is checked, and in step S6, the pulse width corresponding to the element group to which that number belongs is stored, and in step S7
The drive pulse width is increased by 0.5 μs and the process returns to step S2, and the following steps are repeated until the pulse width reaches 7.0 μs.

In this manner, it is determined in step S8 whether the pulse width has become 7.0 μs or more, and when the above-described repetition is completed until the pulse width reaches 7.0 μs, an appropriate pulse width is set for each ejection element in step S9.

An example of the recording pattern obtained at this time is shown in Figs.
Shown in the figure. In these figures, the number of the ejection element is written in a circle, the element which ejected as a result of driving is surrounded by a solid line circle, and the element which failed to eject even if driven is surrounded by a dotted line circle. Note that the numbers of ejection elements that are not driven are not listed. Figure 7 shows a pulse width of 4
．． This shows that all discharges are not ejected when driven at 5 μs. Moreover, FIG. 8 shows the case of driving with a pulse width of 5.0 μs, and the numbers 1.3, 6, . ..., ejection was performed from 4735 elements, and these elements were classified as a group with a pulse width of 5.0 μs. FIG. 9 shows the case of driving with a pulse width of 5.5 μs, and the numbers 2, 8, . Ejection was performed from the elements . . . , and these elements were classified as a group with a pulse width of 5.5 μs. Further, in FIG. 10, the numbers 4.5, 7, . ..., ejection was performed from 4736 elements, and these elements were classified as a group with a pulse width of 6.0 μs. Note that when driving with a pulse width of 6.0 μs, ejection was performed from the ejection element.

The pulse width applied to each ejection element group classified as described above is determined by the voltage application time and characteristics shown in Figures 4 and 5, which are related to the required stable ejection performance and durability. Although it is determined based on the relationship between This is desirable.

Further, in order to detect the numbers of ejecting and non-ejecting elements shown in the patterns shown in FIGS. 7 to 10, the reading head 51 shown in FIG. 1, for example, a one-line long image sensor, is used. An optical reading system or the like may be used.

Note that the full multi-head used in this embodiment is a head in which an independent pulse width can be set for each ejection element. In addition, in the above example, the increments for pulse width setting are 0.
Although the time is 5 μs, it goes without saying that the time is not limited to this.

Next, the predetermined timing of the detection operation for classifying the above-mentioned ejecting and non-ejecting elements according to their driving pulses will be described below.

For example, an integration counter for image input signals may be provided and detection is performed every time the value of the integration counter reaches a predetermined value, or, as an even simpler configuration, a counter may be provided to count the number of recording sheets. Detection may be performed every time the value of the counter reaches a predetermined value.

Alternatively, by setting a non-operating time timer, the detection can be performed every time the non-operating time count by the timer reaches a predetermined time, or immediately before the next recording when the non-operating time exceeds a predetermined time. good.

Furthermore, the detection may be performed when the power is turned on (in any case, the detection (and correction) will be performed automatically at the timing mentioned above).
By implementing this algorithm, variations in ink ejection can be easily corrected without bothering the operator.

[Other Examples]

Next, a second embodiment of the present invention will be described with reference to FIGS. 11 and 12. As shown in FIG. 12, in this embodiment, in addition to the recording ink used during normal recording, the second tank 66 includes ink that has a higher viscosity than the recording ink and has the maximum viscosity that can be ejected by the recording device. , this ink (hereinafter referred to as the second ink) and the recording ink (
This invention is applied to a recording apparatus configured to be able to use the first ink (hereinafter referred to as the first ink) by switching the flow path using the flow path switching means 65.

The correction algorithm of this example shown in FIG.
It is roughly the same as the one shown in the figure, but the difference is that when setting the pulse width for each ejection element group, another minimum pulse width required to eject the second ink, which is different from the first ink, is determined. There is. However, in this embodiment as well, it is desirable not only to simply find the minimum required pulse width, but also to appropriately determine the set pulse width by multiplying it by a predetermined constant.

In FIG. 11, step SIA is an operation of switching to the second ink having a viscosity of 7 cp in this example, and step SIO is an operation of switching to the second ink having a viscosity of 7 cp, and step SIO is an operation of switching to the second ink with a viscosity of 7 cp, and step SIO is an operation of switching to the second ink with a viscosity of 7 cp.
The operation of switching to the original first ink after the pulse width setting for the ink is completed is shown.

Furthermore, as a third embodiment, in the first embodiment, in order to detect variations in ejection force, actual recording was performed and the recorded image was read optically. The droplet detection sensors may be arranged to face each other, thereby detecting non-ejection.

Incidentally, in general, the degree of variation in ejection force when detected at predetermined timing is often smaller than the degree of variation in ejection force during manufacturing. Therefore, when detecting variations in ejection force immediately after manufacture, the detection range is widened, and for example, in the first embodiment, a pulse width is uniformly applied to all ejection elements in the range of 4.5 to 7 μs for detection. , the pulse width at the boundary between ejection and non-ejection is stored for each ejection element.In contrast, in the fourth embodiment, in the detection at each predetermined timing, the pulse width stored in the memory for each ejection element as described above is After first applying the pulse width, the pulse width to be applied around that pulse width is 1 μs.
By changing the level up and down in fine increments, the pulse width at the boundary between ejection and non-ejection can be detected efficiently and more clearly.

(Others) The present invention brings about excellent effects particularly in a bubble jet type recording head and recording apparatus among inkjet recording types.

This is because such a system can achieve higher recording density and higher definition.

As for typical configurations and principles thereof, it is preferable to use the basic principles disclosed in, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740,796. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, it is necessary to arrange the liquid (ink) in accordance with the sheet and liquid path that hold it. The electrothermal converter that is
By applying at least one drive signal that corresponds to the recording information and provides a rapid temperature rise exceeding nucleate boiling, the electrothermal transducer generates thermal energy to cause film boiling on the thermally active surface of the recording head. This is effective because it can result in the formation of bubbles in the liquid (ink) that correspond one-to-one to this drive signal. The growth and contraction of the bubble causes liquid (ink) to be ejected through the ejection opening to form at least one droplet. If this drive signal is in the form of a pulse, bubble growth and contraction will occur immediately and appropriately.
Particularly responsive liquid (ink) ejection can be achieved,
More preferred. This pulse-shaped drive signal is described in U.S. Pat. Nos. 4,463,359 and 4,345,262.
Those described in the specification are suitable. Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

The configuration of the recording head includes, in addition to the combination configuration of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, a heat acting section. The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose configurations in which the wafer is placed in a bending region. In addition, Japanese Patent Application Laid-Open No. 1989-5 discloses a configuration in which a common slit is used as a discharge part of a plurality of electrothermal converters.
No. 9-123670 and Japanese Patent Application Laid-Open No. 59/1989 which discloses a configuration in which a discharge portion is made to correspond to an opening that absorbs pressure waves of thermal energy.
The effects of the present invention are also effective even if the structure is based on the publication No.-138461. That is, regardless of the form of the recording head, according to the present invention, recording can be performed reliably and efficiently.

Furthermore, 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 that can be recorded by a recording apparatus.

Such a recording head may have either a configuration in which the length is satisfied by a combination of a plurality of recording heads, or a configuration as a single recording head formed integrally.

In addition, even with the serial type shown above, the recording head is fixed to the device body, or by being attached to the device body, electrical connection to the device body and ink supply from the device body are possible. The present invention is also effective when using a replaceable chip type recording head or a cartridge type recording head in which an ink tank is integrally provided in the recording head itself.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus, to the present invention, because the effects of the present invention can be further stabilized. Specifically, these include capping means for the recording head, cleaning means, pressure or suction means, preheating means using an electrothermal transducer or another heating element, or a combination thereof; It is also effective to perform a preliminary ejection mode in which ejection is performed separately from printing in order to perform stable printing.

In addition, regarding the type and number of recording heads installed, for example, in addition to one type that corresponds to single-color ink, there is also a plurality of recording heads that correspond to multiple inks with different recording colors and densities. It may be something that can be done. That is, for example, the recording mode of the recording apparatus is not limited to a recording mode for only a mainstream color such as black, but may also be a recording mode in which the recording head is configured integrally or in a combination of multiple colors, The present invention is also extremely effective for devices equipped with at least one full color by color mixture.

Additionally, in the embodiments of the present invention described above,
Although ink is described as a liquid, it is an ink that solidifies at room temperature or below, but softens or liquefies at room temperature, or in an inkjet method, the ink itself is
Generally, the temperature is adjusted within the range of 0°C or more and 70"C or less so that the viscosity of the ink is within the stable ejection range, so the ink is in a liquid state when the recording signal is applied. In addition, the temperature increase due to thermal energy can be actively prevented by using it as energy for changing the state of the ink from a solid state to a liquid state.
Or, in order to prevent ink evaporation, ink that solidifies when left unused is used, and in either case, the ink is liquefied by applying thermal energy according to the recording signal, and the liquid ink is ejected, or the recording medium The present invention is also applicable to the case where an ink that is liquefied only by thermal energy is used, such as an ink that begins to solidify by the time it reaches . The ink for such cases is disclosed in Japanese Patent Application Laid-Open No. 54-56847 or Japanese Patent Application Laid-Open No. 60-7126.
As described in Japanese Patent No. 0, the porous sheet may be held as a liquid or solid in the recesses or through-holes of the porous sheet, facing the electrothermal converter. In the present invention, the most effective method for each of the above-mentioned inks is to implement the above-mentioned film boiling method.

In addition, the inkjet recording apparatus of the present invention can be used as an image output terminal for information processing equipment such as a computer, or as a copying apparatus combined with a reader or the like, or as a facsimile apparatus having a transmitting and receiving function. It may also be something that takes .

〔Effect of the invention〕

As explained above, according to the present invention, the ejection elements are classified as described above at each predetermined timing, and then controlled via the control means to supply electric signals of the ejection possible limit to the ejection elements of each classification. Therefore, even if variations in the ejection force of the print head change over time, it can be easily readjusted, so that good printing conditions can be maintained at all times.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an example of an inkjet recording apparatus according to the present invention, FIG. 2 is a perspective view showing the configuration of a recording head according to the present invention, FIG. 3 is a system diagram of an ink supply and recovery system according to the present invention, and FIG. FIG. 4 is a configuration diagram of a circuit for controlling the drive of the recording head according to the present invention, and FIGS. 5A and 5B show the relationship between voltage application time and ejectable ink viscosity and the relationship between voltage application time and the number of ejectable pulses. FIG. 6 is a flowchart showing the control operation procedure according to the first embodiment of the present invention, and FIGS. 7 to 1O show an example of the pattern of the discharge/non-discharge detection element according to the present invention. 11 is a flowchart showing a control operation procedure according to a second embodiment of the present invention, and FIG. 12 is a system diagram of a supply and recovery system according to a second embodiment of the present invention. 1. IC, IM, IY, IBk...recording head,
21... Electric signal generator, 22... Pulse width and voltage control circuit, 23... Ejection element detection means, 24... Test print, 25... Arithmetic unit, 26... Memory, 103 ...Electrothermal conversion element, 111...Discharge port. Ended 31 months + 7 to the head of the main sentry IS
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Claims (1)

[Scope of Claims] 1) A plurality of ejection elements that eject ink from an ejection port using energy generated in response to an electric signal from an energy conversion means to form flying ink droplets, and the plurality of ejection elements a recording head that performs recording on a recording material using an element; an ejection element detection means that detects ejection or non-ejection of ink from the ejection openings of the plurality of ejection elements; and detection data from the ejection element detection means. a control means for controlling the pulse width and/or voltage of the electric signal supplied to the plurality of ejection elements based on the above, and a pulse width of the electric signal based on detection and detection data by the ejection element detection means at each predetermined timing. and command means for commanding execution of voltage correction. 2) The ejection element detection means has an optical reading means, and the optical reading means can detect images recorded by the plurality of ejection elements driven by electric signals having the same pulse width and voltage. The inkjet recording device according to claim 1. 3) Claim 1, wherein the command means commands detection at a timing related to the recording amount of the recording material.
The inkjet recording device described in . 4) The inkjet recording apparatus according to claim 1, wherein the predetermined timing is set in relation to an operating time or non-operating time of the recording head. 5) The energy conversion means is an electrothermal conversion body that generates thermal energy that causes film boiling in the ink as energy used to eject the ink. The inkjet recording device according to the above item.