JP3183796B2 - Ink jet apparatus and ink jet method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is an ink-jet apparatus Hoyo
It relates fine inkjet method, and more particularly ink jet apparatus and b using an ink-jet head comprising a plurality of ejection heaters in an ink path corresponding to each ink discharge port
It relates to the ink jet method .

[0002]

2. Description of the Related Art Most of ink jet devices are known as printing devices in printers, copiers, and the like. In particular, thermal energy is used as energy used for ink ejection, and ink is ejected by bubbles generated thereby. 2. Description of the Related Art Ink-jet printing apparatuses of the type have recently become widespread. Further, as another application of the ink jet printing apparatus of this type, an ink jet textile printing apparatus for printing a fixed pattern, a picture, a composite image, or the like on cloth has recently been known.

An ink-jet head used in the above-described ink-jet printing apparatus uses an electro-thermal conversion element (hereinafter, also referred to as a heater) for generating thermal energy, but often corresponds to one discharge port. Thus, a configuration having one heater is adopted. On the other hand, an apparatus having a plurality of heaters corresponding to one discharge port has been conventionally known from the following viewpoints.

In other words, first, a plurality of heaters are driven alternately or one by one in order to extend the life of an ink jet head. Secondly, a plurality of heaters are used for the purpose of increasing the range in which the ink ejection amount is changed. Here, the ejection amount is changed by selecting the heaters to be driven and the number thereof.

In the latter case, a more specific configuration is as follows:
By arranging a plurality of heaters in the ink ejection direction in an ink path communicating with the ejection openings of the inkjet head, and selecting the heaters to be driven (that is, the heaters that generate heat) or the number of heaters to be driven, the ejection openings and the heaters that are driven Is known in which the distance between the image forming apparatus and the image forming apparatus is changed, thereby changing the ejection amount.

Further, as another configuration, there is known a configuration in which a plurality of heaters having different surface areas are arranged in an ink path, and the amount of ink discharged is variable by changing the number of heaters or the number of heaters driven in the same manner. I have.

On the other hand, in an ink jet head of the type which discharges ink using the above-described heater, when the head temperature, more specifically, the ink temperature changes, the ink discharge amount changes even if it is not so large. Therefore, for example, if the head temperature rises with the progress of the printing operation, there may be a problem that the image quality changes due to a change in the ejection amount. In order to solve such a problem, the present applicant has proposed, for example, in Japanese Patent Laid-Open No. Hei 5-31905, a configuration for stabilizing the ejection amount regardless of a change in the head temperature. Here, the head temperature is controlled by applying two consecutive pulses to the heater at the time of one ink ejection and controlling the pulse width and the like of the preceding pulse of the two pulses (hereinafter, also referred to as preheat control). The discharge amount is stabilized.

[0008]

By the way, in the above-described configuration in which the ejection amount can be varied in multiple stages by selecting a heater to be driven in the ink jet head using a plurality of ejection heaters, each is set. It is needless to say that it is desirable that the ejection amount is stably maintained.

In this case, it is considered that the above-described configuration of the preheat control is used. However, the relationship between the driving heater at each set discharge amount and the heater performing preheating at that time, the set discharge amount and the width of the preheat pulse There are not few issues to consider in performing optimal discharge amount control at each set discharge amount, such as the relationship with.

The present invention has been made in view of the above, and an object of the present invention is to provide an ink- jet apparatus and an ink-jet method capable of controlling a stable discharge amount for each of a plurality of set discharge amounts.

[0011]

According to the present invention, there is provided:
In an inkjet apparatus that uses an inkjet head having a plurality of heaters corresponding to one ink ejection port and ejects ink from the inkjet head to a medium, a preceding pulse that does not lead to ejection and A head driving unit capable of applying a pulse having a subsequent pulse for generating ink and ejecting ink after a preceding pulse, and corresponding to selection of a heater to which the subsequent pulse is to be applied among the plurality of heaters A discharge amount mode setting means for setting a discharge amount mode, and a pulse waveform setting means for setting the pulse corresponding to the information on the ink temperature of the inkjet head for each discharge amount mode set by the discharge amount mode setting means. By controlling the head driving means based on the setting of the pulse waveform setting means, And pulse control means for applying a pulse to the plurality of heaters, that equipped with features.

In another embodiment, an ink jet head in which a first heater and a second heater are arranged for one discharge port is used, and the first and second heaters are selectively driven, so that a plurality of discharge ports are provided. Means for selectively applying to the first and second heaters a main pulse for discharging ink droplets and a pulse for not discharging ink, in an ink jet apparatus which discharges ink droplets having a discharge amount of It is characterized in that a heater for applying a pulse that does not discharge the ink is switched according to the temperature.

Further, in an ink jet method in which an ink jet head having a plurality of heaters corresponding to one ink ejection port is used and ink is ejected from the ink jet head to a medium, each of the plurality of heaters is provided with an ink jet head. Applying a pulse having no preceding pulse and a succeeding pulse for generating ink bubbles subsequent to the preceding pulse and ejecting ink, and discharging corresponding to selection of a heater to which the subsequent pulse is to be applied among the plurality of heaters. A discharge amount mode setting step of setting an amount mode, and a pulse waveform setting step of setting the pulse corresponding to information on the ink temperature of the inkjet head for each discharge amount mode set by the discharge amount mode setting step. Has a step of applying the pulse, based on the setting of the pulse waveform setting step Characterized in that it is a step of applying a pulse to the number of heaters.

[0014]

According to the above arrangement, the driving of each heater can be controlled for each combination set to be driven among the plurality of heaters. The control of the pre-pulse to be performed becomes possible.

[0015]

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

FIG. 1 is a perspective view showing a printer as an ink jet printing apparatus according to the present invention.

In FIG. 1, reference numeral 101 denotes a printer;
Reference numeral 102 denotes an operation panel unit provided at the front of the upper surface of the housing of the printer 101; 103, a paper feed cassette which is mounted through an opening on the front surface of the housing;
Reference numeral 105 denotes paper (recording medium) supplied from the paper feed cassette 3, and reference numeral 105 denotes a paper discharge tray for holding paper discharged through a paper conveyance path in the printer 101. Reference numeral 106 denotes a body cover having an L-shaped cross section. The main body cover 106 has an opening 10 formed in the front right portion of the housing.
7 and the hinge 108 opens the opening 10
7 is rotatably attached to the inner end. Also,
A carriage 110 supported by a guide or the like (not shown) is provided inside the housing. Carriage 11
Numeral 0 is provided so as to be able to reciprocate along the width direction of the paper passing through the paper transport path (hereinafter, also referred to as the main scanning direction).

The carriage 110 in this embodiment has a stage 110a which is held horizontally by a guide or the like;
An opening (not shown) for mounting an ink jet head behind the stage 110a, and a housing for accommodating the ink jet heads 3Y, 3M, 3C and 3Bk detachably mounted on the stage 110a in front of the opening. It is schematically constituted by a cartridge garage 110b and a cartridge holder 110c which is opened and closed with respect to the garage 110b to prevent the cartridge accommodated in the garage 110b from being detached.

The stage 110a is slidably supported by a guide at a rear end thereof, and a lower side of a front end thereof is slidably engaged with a guide plate (not shown). The guide plate may function as a paper holding member for preventing the paper conveyed on the above-described paper conveyance path from rising, and the stage may be cantilevered relative to the guide according to the thickness of the paper. It may have a function of lifting the object.

An ink jet head (not shown) is mounted on the opening of the stage 110a with its ink discharge port directed downward.

In the cartridge garage 110b, through holes are formed in the front-rear direction for accommodating the four ink cartridges 3Y, 3M, 3C, 3Bk at the same time, and engaging claws of the cartridge holder 110c are formed on both outer sides. A mating engagement recess is formed.

A hinge 11 is provided at the front end of the stage 110a.
6, the cartridge holder 110c is rotatably mounted. The dimensions from the front end of the garage 110b to the hinge 116 are the same as those of the cartridge 3Y,
When 3M, 3C, and 3Bk are accommodated in the garage 110b, they are determined in consideration of the dimensions that protrude from the front end of the garage 110b. The cartridge holder 110c has a substantially rectangular plate shape. The cartridge holder 110c has a pair of upper and lower sides separated from the lower part fixed by the hinges 116, which project in a direction perpendicular to the plate surface, and which, when the holder 110c is closed, engage with the engaging recesses 110d of the garage 110b. A pair of engaging claws 110e to be engaged are provided. The holder 110c is formed with a fitting hole 120 for fitting the handle portion of each of the cartridges 3Y, 3M, 3C, 3Bk to its plate portion. These fitting holes 120 have a position, a shape, and a size corresponding to the handle.

FIG. 2 is a block diagram showing a configuration example of a control system in the ink jet printing apparatus.

Here, reference numeral 200 denotes a controller constituting a main control unit, for example, a CPU 201 in the form of a microcomputer for executing various modes to be described later, a program and a table corresponding to the procedure, a voltage value of a heat pulse, a pulse width and other information. It has a ROM 203 storing fixed data, and a RAM 205 provided with an area for developing image data and a work area. Reference numeral 210 denotes a host device (which may be a reader unit for image reading) serving as a source of image data, and image data and other commands and status signals are transmitted to and received from the controller via an interface (I / F) 212. .

The operation panel 102 has a mode selection switch 22 for selecting various modes as described later.
0, a power switch 222, a print switch 224 for instructing the start of printing, and a large recovery switch 226 for instructing activation of the ejection recovery process. 230 is a carriage 110 such as a home position and a start position.
A sensor group for detecting the state of the apparatus, such as a sensor 232 for detecting the position (see FIG. 1) and a sensor 234 for detecting a pump position including a leaf switch.

Reference numeral 240 denotes a head driver for driving the electrothermal transducer of the ink jet head according to print data and the like. A part of the head driver is also used to drive the temperature heaters 30A and 30B. Further, temperature detection values from the temperature sensors 20A and 20B are input to the controller 200. Reference numeral 250 denotes a main scanning motor for moving the carriage 110 in the main scanning direction, and reference numeral 252 denotes its driver. Reference numeral 260 denotes a sub-scanning motor, which is used to convey the paper 104 (see FIG. 1) as a recording medium.

The above-described ink jet printing apparatus has four
Ink cartridges 2C and 2 for each color ink, cyan, magenta, yellow and black
M, 2Y, 2Bk.

FIG. 3 is a sectional view showing the ink tank cartridge 3 and the ink-jet head 2 used in the above-described ink-jet printing apparatus in a state where they are connected.

The ink tank cartridge 3 used in the present embodiment has a negative pressure generating member accommodating section 53 filled with an ink absorber 52 and an ink accommodating section 56 filled with nothing.
In the initial state, ink is stored in each of these two chambers. The ink is first consumed from the ink stored in the ink storage unit 56 in accordance with the ink ejection or the like in the inkjet head 3.

The ink jet head 2 has a heater (not shown in FIG. 3) for generating thermal energy used for ejection.
To ink paths 2 respectively corresponding to a plurality of ink ejection ports.
A, discharges ink supplied from the ink tank cartridge 3 through the connection pipe 4.

FIG. 4 is a schematic sectional view showing the structure of the ink jet head 2 according to one embodiment of the present invention.

As shown in FIG. 4, two heaters SH1 and SH2 are arranged in each ink path 2A in the arrangement direction. These two heaters have different surface areas from each other. The heaters can be driven independently and independently, and electrode wiring and the like (not shown) are provided so that the two heaters can be driven simultaneously. Is provided. In addition,
The heater SH1 and the heater SH2 have the same length in the longitudinal direction of the ink path 2A, and have different surface areas by making the widths different from each other. Ink path 2
A discharge port 2N is open at the tip of A.

The above-described structure of each ink path unit including the heater, the discharge port, the ink path, and the like is provided in the ink jet head 2 at a predetermined density of 720 DPI. The opening area of the discharge port and the heater area in the unit are the same between the ink path units.

In this embodiment, when two heaters are used, the discharge amount is basically set in three stages for each discharge port (hereinafter referred to as a basic discharge amount mode) according to the combination of the heaters to be driven. It becomes possible.

In the basic discharge amount mode of this embodiment, three discharge amount modes, small, medium and large, are basically set by switching the heater to be driven. In the small discharge amount mode, only the heater SH1 is driven to discharge droplets having a volume of 15 pl. In the medium discharge amount mode, only the heater SH2 is driven.
pl of liquid droplets, and the heater SH1 in the large discharge amount mode.
And SH2 are driven simultaneously, and 40 pl (= 15 + 25)
pl).

Next, the discharge stabilization control of this embodiment will be described below.

FIG. 5 is a diagram showing the temperature dependence of the ejection amount in each of the above-described ejection amount modes in the configuration of the ink jet head of this embodiment. The driving condition shown in this figure is a case where a rectangular pulse having a voltage of 18 V and a pulse width of 5 μsec is applied to each of the heaters SH1 and SH2.

As shown in FIG. 5, the discharge amount increases as the head temperature increases. In the temperature range shown in the drawing, this change is almost linear, and the change rate of the discharge amount Vd with respect to the temperature T is α in the small discharge amount mode, β in the medium discharge amount mode, and γ in the large discharge amount mode.

On the other hand, at a constant environmental temperature, a drive pulse composed of two pulses as shown in FIG. 6 (hereinafter also referred to as a double pulse) is applied, and the discharge is performed when the pulse width P1 of the pre-pulse is changed. The amounts are as shown in FIG.

In the double pulse shown in FIG. 6, P1 indicates the pulse width of the pre-heat pulse, and the pre-heat pulse heats the ink near the heater, but performs heating to such an extent that foaming does not occur. Thereafter, after a pause time P2, a main heat pulse having a pulse width P3 is applied to generate bubbles in the ink, thereby discharging the ink.

In such a double pulse drive, if the pre-pulse width P1 is increased as shown in FIG. 7, the discharge rate increases at a constant rate in any discharge rate mode.

Accordingly, by utilizing the relationship shown in FIG. 7 and the relationship shown in FIG. 5 described above, the pre-pulse width P1 is made variable in accordance with the head temperature, regardless of the change in the head temperature as shown in FIG. The discharge amount can be controlled to a predetermined value. That is, when the head temperature increases, control is performed to reduce the pre-pulse width P1 accordingly.

FIG. 9 is a block diagram showing an example of a basic configuration of the discharge amount control.

In FIG. 9, temperature sensors 20A and 20B
The drive waveform parameter setting table 21 based on the head temperature from the head temperature detection unit 212 including (see FIG. 2)
With reference to 0, parameters of the pulse waveform such as the pre-pulse, the pause period, and the pulse width of the main pulse are output to the drive waveform setting units 211A and 211B.

The drive waveform setting sections 211A and 211B select one of the waveforms indicated by to corresponding to the heaters SH1 and SH2 according to the ejection amount mode input thereto, and input the waveform from the table 210. Set parameters such as pulse width. In the waveform selection from the waveforms of the heaters SH1 and SH2 in accordance with the discharge amount mode, for example, in the large discharge amount mode, the main pulse is applied to the heaters SH1 and SH2, or A waveform including at least a pre-pulse must be selected for one of the heaters.

However, as described above with reference to FIG. 7, since the dependence of the discharge amount differs for each discharge amount mode, it is more preferable to provide a parameter setting table for each discharge amount mode.

FIG. 10 is a block diagram showing a configuration for enabling parameter setting for each discharge amount mode.
FIG. 1 is a conceptual diagram showing a table for setting each drive heater according to the discharge amount mode in this configuration.

In FIGS. 10 and 11, the main pulse drive heater setting unit 214 determines the heater S according to the set discharge amount mode from the discharge amount mode information holding unit 213.
Either H1, heater SH2, or heater SH1 + SH2 is set. In the drive waveform parameter setting table, one of the tables 210A, 210B, and 210C corresponding to the set main pulse drive heater is selected, and the drive waveform parameter is set based on the head temperature information from the selected table. Is output.

The combination of the preheat pulse drive heaters shown for each discharge amount mode in FIG. 11 is an example of the one selected corresponding to the selected main pulse drive heater, and will be described in the following embodiments. Things.

(Embodiment 1) FIGS. 12 (a), 12 (b) and 12 (c) relate to a first embodiment of the present invention and show driving waveform parameter setting tables 210A, 210B and 210C.
FIG. 11 is a diagram showing a pre-pulse width P1 setting table in (see FIG. 10). FIGS. 13A, 13B, and 13C show the heater drive set by the main pulse drive heater setting unit 214 (see FIG. 10) and the setting tables 210A, 210B, and 210C in this embodiment. It is a figure showing a pulse waveform.

As is clear from these figures, in this embodiment, the heater SH1 which is the smaller heater in the small discharge amount mode, the heater SH2 which is the larger heater in the medium discharge amount mode, and the large discharge In the quantity mode, the heater SH1
Using the heater SH2 and the heater SH2, the control of the pre-pulse width P1 according to the head temperature is also performed for the heater that performs main heat (heater driving for bubble generation).

As shown in FIG. 12, the control of the pre-pulse width P1 according to the head temperature shortens the pulse width P1 as the detected head temperature increases. Here, in the medium ejection amount mode, the head temperature is 4
When the temperature is 4 ° C. or higher, no preheating is performed.

By controlling the pre-pulse width as described above, the discharge amount Vdo for each discharge amount mode in the PWM control range (15 pl for the small discharge amount mode, 25 pl for the medium discharge amount mode, and the large discharge amount as shown in FIG. 8). The mode can stabilize 40 pl) in a substantially constant range. In this embodiment, when the head temperature is 26 ° C. or lower (T ₀ shown in FIG. 8), the head temperature is controlled using a heater for controlling the temperature provided in the ink jet head, thereby stabilizing the discharge amount Vd.

(Embodiment 2) FIGS. 14A, 14B and 14C show a pre-pulse width P1 according to a second embodiment of the present invention.
FIG. 15 is a diagram showing a drive pulse waveform. As shown in these drawings, the difference from the first embodiment described above is the pre-pulse width control in the medium ejection amount mode and the large ejection amount mode.

That is, in the medium discharge amount mode, a pre-pulse is applied to the small heater SH1 in addition to the large heater SH2. Here, the pre-pulse width P1 of the small heater SH1 is fixed in the range of 26 ° C. to 46 ° C. 1 μsec)
The pre-pulse width P1 of the large heater is controlled so as to become shorter as the head temperature increases. At 46 ° C or higher,
The pulse width P1 of the large heater is set to 0, while the pulse width P1 of the small heater is reduced as the head temperature increases.

In the medium discharge amount mode, the pre-pulse is driven by both the small and large heaters in spite of the fact that the main (heat) pulse is only the large heater SH2, so that the stable control temperature range of the discharge amount is widened. It is possible to do. As a result, the discharge amount in the medium discharge amount mode is 28
pl, which can be set slightly larger than the 25 pl of the first embodiment.

In the large discharge amount mode, both the small heater SH1 and the large heater SH2 are used, but the control of the pre-pulse width is performed in the same manner as in the above-described medium discharge amount mode.

(Embodiment 3) FIGS. 16 and 17 are diagrams showing tables of pre-pulse widths P1 according to a third embodiment of the present invention, and FIG. 18 is a waveform diagram of drive pulses in this embodiment.

In this embodiment, the table of the pre-pulse width P1 is switched between a low-temperature table and a high-temperature table according to the head temperature at the start of printing. Equipped. FIG.
6 shows a low-temperature table in the small discharge amount mode and the medium discharge amount mode. The high temperature tables in these modes are the same as those shown in FIGS. 12 (a) and 12 (b). FIG. 17 shows a low-temperature table and a high-temperature table in the large discharge amount mode, respectively.

As can be seen from these figures and FIG.
The preheat pulse is applied to the large heater in the low temperature mode,
In the high temperature mode, the voltage is applied to the small heater.

In the present embodiment, in the low-temperature mode, the heater is preheated by a heater different from the heater that performs the main heat. Has little effect on foaming at

Further, by performing preheating with different heaters, the influence between the pre-pulse and the main pulse (pause period) can be shortened because the influence of the foaming need not be considered so much. Further, by providing the low-temperature mode as described above, it is not necessary to substantially use the above-described head temperature control means.

Further, in this embodiment, by providing two tables for the head temperature in an overlapping manner, it is not necessary to switch the heater for applying the pre-pulse at least in the page being printed. It is possible to prevent image streaks from occurring due to a difference in density that may occur.

(Embodiment 4) FIGS. 19 (a) to 19 (c) are diagrams showing off-time tables in each discharge amount mode according to a fourth embodiment of the present invention, and FIGS. (c) is a diagram showing the waveform of the drive pulse.

In this embodiment, as is clear from FIGS. 19 and 20, the small heater SH1 in the small discharge amount mode and the large heater SH2 in the medium discharge amount mode, as in the first embodiment.
The large and small heaters SH1 and SH2 are used for a large discharge amount.

However, different from the first embodiment, the discharge period is stabilized by controlling the rest period (off time) P2. That is, the off-time P2 is changed while the pre-pulse width P1 is fixed, but the fact that the ejection amount becomes larger as P2 becomes longer is applied here. Specifically, P2 is made shorter as the head temperature rises, and P2 is made longer as the head temperature falls.

As in the case of the pre-pulse width, the temperature dependency and the P2 dependency of the discharge amount differ for each discharge amount mode. Therefore, by setting a table of the off-time P2 according to each discharge amount mode, each discharge amount is set. A stable discharge amount can be obtained in the mode.

(Embodiment 5) FIG. 21 is a diagram showing a table of the off-time P2 as in the above-described Embodiment 4, and FIG. 22 is a diagram showing the waveform of the drive pulse.

In the present embodiment, as in the above-described fourth embodiment, the off-time P2 is controlled to stabilize the discharge amount.
The mode is slightly different depending on the discharge amount mode.

That is, in the small discharge amount mode and the medium discharge amount mode, the preheating is performed using a heater different from the heater performing the main heating. In this case, since the ejection amount increases as the off-time P2 increases, control is performed such that the off-time P2 decreases as the head temperature increases. In such a control, the pre-pulse P
Since 1 and the main pulse P3 do not have a double pulse relationship, it is also possible to set the pre-pulse P1 and the main pulse P3 to overlap on the time axis.

Further, if the off-time P2 of the double pulse is shortened by the same heater, the pulse eventually becomes a single pulse. Regardless, since there is some delay at the falling edge of the rectangular wave, there is a possibility that the pre-pulse P1 and the main pulse P3 are connected and become a single pulse having a large pulse width, but this embodiment can also prevent such a case. .

Next, in the large discharge amount mode, both the large heater and the small heater have a double pulse waveform, but the off-time of one of the heaters is made variable to control the timing of the main pulse and shift the foaming timing. I do.

This focuses on the fact that the discharge amount is reduced due to a shift in the bubbling timing of a plurality of heaters. However, as in the small and medium discharge amount mode, only the control of P2 is performed during the off-time. It is possible to shift the foaming timing.

(Other Embodiments) In each of the above embodiments of the present invention, a configuration in which a plurality of heaters are provided side by side corresponding to one discharge port shown in FIG. 4 has been described.
In the case of a configuration in which the heaters are vertically arranged as shown in FIG. 3, the same effects as in the above embodiments can be obtained. The same applies to a head configuration for ejecting ink droplets upward with respect to the heater surface as shown in FIG.

Although the heater sizes have been described with different sizes here, the same effect can be obtained with the same size. However, in the case of the same size, the ejection amount basically becomes two modes of large and small.

Further, although not particularly described in each of the above embodiments, it is better that the distance between the heaters is short, and the effects are particularly enhanced in the second, third, and fifth embodiments.

Further, the description has been given of changing the parameters such as the pre-pulse width P1 according to the head temperature. However, for example, the target temperature is set according to the environmental temperature, and the parameters are changed according to the difference between the head temperature and the target temperature. If you do
An even more stable discharge amount can be obtained. That is, when the environmental temperature is different even if the head temperature is the same, the ink temperature is basically close to the environmental temperature including the supply system.

(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 discharging ink, 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 a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US 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-angle liquid flow path) as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat.
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. 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, the recording head fixed to the apparatus main body or the electric connection with the apparatus main body and the ink from the apparatus main body are attached by being mounted on 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.

It is preferable to add ejection recovery means for the recording head, preliminary auxiliary means, and the like as the configuration 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 temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or to prevent evaporation of the ink, 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 solidifying when it reaches 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.

[0087]

As described above, according to the present invention,
The driving of each heater can be controlled for each combination set to be driven among the plurality of heaters, and the pre-pulse applied for stabilizing the discharge amount can be controlled for each combination.

As a result, stable ejection amount control can be performed, and a high-quality image can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an inkjet printing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram mainly showing a control configuration of the printing apparatus.

FIG. 3 is a cross-sectional view illustrating an ink jet head and an ink tank cartridge used in the apparatus.

FIG. 4 is a sectional view showing the structure of the inkjet head according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a relationship between a head temperature and a discharge amount for each discharge amount mode according to the embodiment of the present invention.

FIG. 6 is a schematic diagram showing a waveform of a pre-pulse used in the embodiment of the present invention.

FIG. 7 is a diagram showing a relationship between a pre-pulse width and a discharge amount for each discharge amount mode in the embodiment of the present invention.

FIG. 8 is a diagram showing a mode of discharge amount control in the embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of driving a heater according to an embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration of driving a heater according to a preferred embodiment of the present invention.

FIG. 11 is a diagram illustrating a relationship between a discharge amount mode and a main pulse driving heater and a pre-pulse driving heater according to some embodiments of the present invention.

FIGS. 12A to 12C are schematic diagrams showing tables of pre-pulse widths P1 for respective ejection amount modes according to the first embodiment of the present invention.

FIGS. 13A to 13C are waveform diagrams of driving pulses in the embodiment.

FIGS. 14A to 14C are schematic diagrams showing tables of pre-pulse widths P1 for respective ejection amount modes according to the second embodiment of the present invention.

FIGS. 15A to 15C are waveform diagrams of driving pulses in the embodiment.

FIGS. 16A and 16B are schematic diagrams showing a table of a pre-pulse width P1 for each ejection amount mode according to the third embodiment of the present invention.

FIGS. 17A and 17B are schematic diagrams showing a table of a pre-pulse width P1 for each discharge amount mode according to the third embodiment of the present invention.

FIGS. 18A to 18C are waveform diagrams of driving pulses in the above embodiment.

FIGS. 19A to 19C are schematic diagrams showing tables of off-time P2 for each ejection amount mode according to the fourth embodiment of the present invention.

FIGS. 20A to 20C are waveform diagrams of driving pulses in the embodiment.

FIGS. 21A to 21C are schematic diagrams showing tables of off-time P2 for each discharge amount mode according to the fifth embodiment of the present invention.

FIGS. 22A to 22C are waveform diagrams of driving pulses in the embodiment.

FIG. 23 is a cross-sectional view illustrating a structure of an inkjet head according to another embodiment of the present invention.

FIG. 24 is a cross-sectional view illustrating a structure of an inkjet head according to still another embodiment of the present invention.

[Explanation of symbols]

 2, 2Y, 2M, 2C, 2Bk Inkjet head 2A Ink path 2N Discharge port 200 Controller SH1, SH2 Heater

──────────────────────────────────────────────────続 き Continuing on the front page (72) Shigeyasu Nagoshi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Masao Kato 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Fumihiro Goto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-5-31905 (JP, A) JP-A-3-284951 (JP, A) JP-A-7-232441 (JP, A) JP-B-62-46358 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/05 B41J 2 / 205

Claims (16)

(57) [Claims] 1. An ink jet apparatus which uses an ink jet head having a plurality of heaters corresponding to one ink discharge port and discharges ink from the ink jet head to a medium, wherein each of the plurality of heaters discharges ink. A head driving unit capable of applying a pulse having no preceding pulse and a succeeding pulse for generating ink bubbles following the preceding pulse to eject ink, and a heater to which the following pulse is to be applied among the plurality of heaters Discharge amount mode setting means for setting a discharge amount mode corresponding to the selection of, for each discharge amount mode set by the discharge amount mode setting means,
Pulse waveform setting means for setting the pulse corresponding to information on the ink temperature of the inkjet head; and applying a pulse to the plurality of heaters by controlling the head driving means based on the setting of the pulse waveform setting means. An ink jet apparatus comprising: 2. The inkjet head according to claim 1, wherein the inkjet head has an ejection amount mode using a first heater, an ejection amount mode using a second heater, and an ejection amount mode using the first and second heaters. Inkjet device. 3. The ink jet apparatus according to claim 1, wherein the control of the preceding pulse is performed based on at least one of temperature information of the ink jet head and a calculated value of the temperature of the ink jet head. 4. The ink jet apparatus according to claim 1, wherein at least one of a setting of a heater for applying the preceding pulse and a preceding pulse control mode is changed according to the ejection amount mode. 5. The ink jet apparatus according to claim 1, wherein at least the preceding pulse is applied to a heater that applies the subsequent pulse. 6. The apparatus according to claim 1, wherein a preceding pulse is given to a heater other than the heater to which the succeeding pulse is applied.
5. The ink-jet apparatus according to any one of claims 1 to 4. 7. The ink jet apparatus according to claim 3, wherein the control of the preceding pulse is performed by changing a pulse width of the preceding pulse. 8. The ink-jet apparatus according to claim 3, wherein the control of the preceding pulse varies the time between the preceding pulse and the succeeding pulse. 9. The ink jet apparatus according to claim 2, wherein a control mode is changed according to the discharge amount mode. 10. An ink jet head in which a first heater and a second heater are arranged for one discharge port, and selectively driving the first and second heaters to thereby form a plurality of discharge amounts of ink. In an ink jet apparatus for ejecting droplets, a main pulse for ejecting ink droplets and a pulse for not ejecting ink are selectively applied to the first and second pulses.
An ink jet apparatus that switches between a means for applying a voltage to the heater and a heater for applying a pulse that does not discharge the ink in accordance with the head temperature. 11. The ink-jet apparatus according to claim 10, wherein a pulse that does not discharge the ink and the main pulse are applied by different heaters. 12. The apparatus according to claim 1, wherein the pulse waveform setting unit is a unit that performs setting so as to change a waveform of a preceding pulse among the pulses in accordance with information on an ink temperature for each of the ejection amount modes. The inkjet device according to claim 1, wherein 13. The pulse waveform setting means is means for performing setting so as to change an interval between a preceding pulse and a succeeding pulse among the pulses in accordance with the information regarding the ink temperature for each ejection amount mode. 2. The method according to claim 1, wherein
An inkjet device according to item 1. 14. An ink-jet method in which an ink-jet head provided with a plurality of heaters corresponding to one ink discharge port and discharges ink from the ink-jet head to a medium is provided. Applying a pulse having no preceding pulse and a succeeding pulse that generates air bubbles following the preceding pulse to eject ink, and discharge corresponding to selection of a heater to which the subsequent pulse is to be applied among the plurality of heaters. A discharge amount mode setting step of setting the discharge amount mode; and a discharge amount mode set by the discharge amount mode setting step.
A pulse waveform setting step of setting the pulse corresponding to the information on the ink temperature of the inkjet head, wherein the step of applying the pulse includes a step of applying a pulse to the plurality of heaters based on the setting of the pulse waveform setting step. An inkjet method. 15. The pulse waveform setting step is a step of performing setting so as to change a waveform of a preceding pulse among the pulses in accordance with information on an ink temperature for each of the ejection amount modes. The inkjet method according to claim 14, wherein 16. The pulse waveform setting step is a step of performing setting so as to change an interval between a preceding pulse and a succeeding pulse among the pulses in accordance with the information regarding the ink temperature for each ejection amount mode. 2. The method according to claim 1, wherein
5. The inkjet method according to 4.